Full text of "Power"
Digitized by the Internet Archive
in 2010 with funding from
University of Toronto
http://www.archive.org/details/powereng41newy
POWER
DEVOTED TO THE GENERATION AND
TRANSMISSION OF POWER
ISSUED WEEKLY
VOLUME XLI
X^
January 1 to June 30, 1915 ^^. ~ I
1
?>°
Hill Publishing Co.
HILL BUILDING
10TH AVENUE AT 36TH STREET
NEW YORK
INDEX TO VOLUME XLI
January 1 to June 30, 1915
Explanatory Note
Illustrated articles are marked with an
asterisk (•>, book notices by a dagger
(.1), inquiries by a double dagger (±).
The cross-references condense the mater-
ial and assist the reader, but are not to
be regarded as complete or conclusive.
So, it' there were a reference from
"Boiler" to "Blowoff," and if the searcher
failed to find the required article under
the latter word, he should look through
the "Boiler" entries, or others that the
topic might suggest, as he would have
done had there been no cross-reference.
A reference from "Oil" to ".Lubricating"
would apply equally to "Lubrication,"
"Lubricator," etc. Letters are indexed
under title or subject, general articles
under writer's name as well. Not all
articles relating to a given topic neces-
sarily appear under the same entries.
Following' is a list of the pages in-
cluded in the several numbers of the
volume, by date:
Jan. 5 pages 1-36
12 " 37-74
19 •' 75-110
26 " 111-148
Feb. 2 " 149-180
9 " 181-216
16 " 217-248
" 23 " 249-2S4
Mar. 2 " 285-318
9 " 319-356
16 " 357-388
23 " 389-420
30 " 421-458
Apr. 6 " 459-492
13 " 493-526
20 " 527-560
27 " 561-592
May 4 '.' 593-624
11 " 625-660
18 " 661-696
25 " 697-730
June 1 " 731-762
8 " 763-796
15 " 797-828
22 •• 829-866
29 " 867-904
Page
Abnormal conditions. Recognizing... 718
Accepting the inevitable 751
Accident. See also cross-references
from "Explosion."
Accident, Engineer killed in peculiar
turbine, N. T. Cy. Southard 891
Accident prevented. Robinson '789
Accidents — First-aid jar '185, 202
Accumulator piping for two pres-
sures. Williams »671
Accumulator, Step-bearing. Bank-
head «265
Addy. Long chances with portable
engine 814
Adsco graduated radiator valve '115
Air-bound centrifugal pump. Mc-
Morro w *854
Air-chamber supply. Maintaining. .. ±487
Air, Composition of. Palmer 65
Air. Compressed — Cummlngs return-
pipe system. Richards »224
Air, Compressed, Engine operated
with. Reed '621
Air, Compressed, Reheating 543
Air compressor. See also "Blowing
engine."
Air-compressor cylinder ratios. Sal-
mon *472
Air-compressor feather-valve test,
Forty-mill ion -revolution, Laidlaw-
Dunn-Gordon plant *537
Air compressor. Imperial portable,
Ingersoll-Rand Co.'s »86
Air compressor, Ingersoll-Rand high-
efficiency '888
Page
Air-compressor motor stator connec-
tions wrong. Horton 893
Air-compressor piston failure. Wer-
ner 254
Air-compressor water-jacket scale
removal. Henry »787, Oil-engine
jacket. Morrison 856
Air compressors, Cold-air intake duct
for. Bayard 715
Air compressors, High-speed, Plate
valves for. McFadden *366, Blount 717
Air for burning coal $277, ±857
Air from condensers, Removing.
Cay wood *723
Air gap, Unequal. Justus *619
Air hose and bucket as ammonia
helmet. Robertson 518
Air in jet-condenser practice. Brown 404
Air-lift efficiency. Ivens *843
Air lifts, etc. — Selecting pump. Hub-
bard «198, 345, 519
Air pump. Combined condensate and
turbo *477
Air-pump test, Wheeler turbo.. *442, «870
Air, Pumping with compressed 120
Air, Saturated, properties. Ennis... 402
Air-tank bumped heads 202
Air tank. Safety valve for ±655
Air testing in refrigeration plant.
Solomon 839
Alarm, Ammonia-compressor. Rob-
ertson S15
Alarm, Step-bearing accumulator .. .*265
Alarm, Tank float and. Cobb *725
Alaskan coal 215
Aligning generator. Walehl. *892
Allgemeine Elektricitiits Gesell-
schaft's small Diesel engines *162
Alloys — Three-metal bronzes 373
Alternating current. See "Electric-
ity."
Aluminum Co. of Am. converter sta-
tion *776
Ambition, The power of *763
American Asso. for Advancement of
Science 6S
American Asso. of Refrigeration ... .*72S
American Boiler Mfrs.' convention.. 896
American Cigar Co.'s plant, Heating
and vent. Durand •460. 541
American Engineering Co.'s power
plant *3S
American Gas & Elec. plant '868
American Inst. Elec. Engineers' con-
vention, etc 316, »491, *5S9, 657
American Mfg. Co. buys power 380
American Meat Packers' Asso 727
American Ry. Master Mechanics' Asso. S65
American Soc. H. & V. Engineers
•17T,. |-695
American Soc. Mech. Eng. See "En-
gineers."
Ammonia. See generally under "Re-
frigeration."
Ammonia as heat vehicle. Johnson 727
Ammonia leaks, Detecting. Thurston 101
Analyzing plant's condition. Lass
75, Ed. 238. Hawkins 239. Robinson 4S1
Anchoring bolts in concrete. Croft. *S41
Anderson. Heating feed water 544
Annett. Why D.C. motors fail to
start '194, »230, 452
Appearance, Power-plant. Dreyfus.. 138
Aqueduct, Monster, Los Angeles 565
Arch, Staying furnace. Hawkins. .. ,*600
Armature test. Bar-to-bar ±102
Armature winding, D.C. Gintz *335
Arrowrock dam construction power
plant. Connor *594
Ash-content influence. Ellis, Hubbard 654
Ash ejector, Live-steam. Jorgcnson
169. Burns, Clevenstine «240, Pearce.*411
Ash-handling apparatus, Scranton;
flushing ashes into mine *872
Ash handling by flushing *454
Ash -hand ling systems. Vacuum. < >per-
ating cost. Girtanner - Daviess,
Miller 206, 412, Sandstrom, Pren-
tiss 412
Page
Ash handling. Vacuum, Union Brew-
ery *664, Cost, Miller, Girtanner-
Daviess 820
Ashes, Dredge pump handles. Ha-
vard *580
Atchison. History of thermometer.. 575
Atkins nonbreakable hacksaw blade. *401
Automobile piston fits. Weaver. ... *245
Automatic sprinklers. Benefiel *19
Auto-transformers, Operation and
design of. Meade '804
Auxiliaries, Motor-driven, Cleveland
municipal plant *104
Babbitt metal, Original ±102
Babbitt-metal pouring temperature. J521
Babbitt metals, Pouring of J591
Back-pressure valves, Drains above. 205
Backfiring trouble ±555
Balancer set, etc. Hull «226
Ball engine valve, Reseating. Jannet.*518
Ballard. Cleveland municipal elec.
plant «104
Baltimore, Jet condenser at *20
Baltimore sewage pumping. Rogers
•76. Westport power plant. Rogers. *390
Banger. Motors to put engines out
of business *742
Bankhead. Step-bearing accumula-
tor »265
Barker. Future developments in
heating and ventilation 897
Barton expansion trap redesigned.. 327
Battery. Storage, and its limitations.
Dawson 821
Battery, Storage, Elements of 301
Battery, Storage, inspection ±102
Battery, Storage, Low-gravitv cutout
for. Dixon «720
Batteries, Dry, Protecting. Beattie. . 411
Batteries, Storage, Charging small.
Miles *757
Batteries, Storage, for peak loads.
Brown *470
Baum£ degrees and specific gravities. ±587
Bayard. Cold-air intake duct for air
compressors 715
Bayer monkey-wrench »264, Feed-
water purifier „ *400
Bean. Fuel oil for locomotives '900
Bearing, Hot generator. McClinton . *S51
Bearing invention, Kingsbury's
thrust . 339
Bearings — Crankpin troubles.
Haynes 120
Beaver crossbar die stock »644
Belt. Advantage of narrower ±759
Belt dressings — Relative merits. .. .±857
Belt, Open, Obtaining length ±521
Belt running untrue — Causes 374
Belting calculations. Waters 543
Belting, Rubber and leather, Relative
transmission bv ±277
Belts— Fluid Cling-Surface 600
Bender, Pipe. Chandler »60
Benedict. Low-pressure turbines. . *326
Benefiel. Fire-protecting apparatus '19
Bennett. Speed characteristics of D.
C. motors *125
Berkeley Cotton Mills' flywheel. ... *439
Berwind-White mining plant «160
Bessemer Coal & Coke Co.'s boiler
plant. Rogers «798, 817
Better be sure than sorry «37
Bidding, Evils of low 480
Big Creek development snapshots. .*S42
Bismarck, N. D. — Hughes plant .... *732
Blackburn-Smith twin filter »270
Blish. Testing small centrifugal
pumps »370, 551, *616
Blower. See also "Fan."
Blower, Large Buffalo transformer.
Blue Island Power Station, North-
ern 111 «533
Blower, Siemens-Schuckert "Schlot-
ter." Gradenwitz *261
Blower, Turbo, Standard Iron Co.'s.. *49
Blower, Turbo undergrate, Sturtevant »7
P OWER
January 1 to June 30, 1915
Page
Blowers, Notes on. Potter, Simmer-
ing S16
Blowing engine, Large gas Mesta...*395
Blowoft basin, Concrete, Cleveland.
Williams *373
Blowoft, Circulating pipe for +4S7
B 1 o w o ft cocks, Asbestos-packed.
Burns 64
Blowoft, Keeping, from freezing.
Noble *9S
Blowoff pipe, Feeding through 735
Blowoff pipe open at one end. Binns *59
Blowoff pipes, Water hammer in.
Hurst 30, Preventing. Fenwick
•650, Noble 754
Blowoff piping, Bent. Epply *724
Blowoff-piping failures. Woodruff. . 5S6
Blowoff piping, Unsafe. Knowland 206
Blowoff valve opened — Boiler in-
spector confesses *319, Garlick.... 520
Bluff — Longer way safer *2S5
BOILER
See also "Coal," "Steam," "Blow-
off," "Stoker," "Smoke," "Carbon
.lioxide." "Gage." "Valve — Safety,"
"Draft," "Ash." "Heater," "Engi-
neers' license," "Power plants."
— Accidents — A. S. M. E. report 499
— Am. Boiler Mfrs.' convention 896
— Bessemer Coal & Coke Co.'s boiler
plant — Burning bone coal. Rogers,
*79S, 817
— Blower, Sturtevant turbo under-
grate *7
— Boilers. Monnett — Reconstructing
water-tube boiler settings; baffling;
low headroom, etc. *54, *91, Cor-
rection as to underfeed stokers
•132. Waste-heat boilers with met-
allurgical furnaces; stokers »196,
Metallurgical and special furnaces *432
■ — Butt joint with single cover plate 1S23
— Calking butt and double-strap
joint 1349
■ — Car for inside of boiler. Chrisman *647
— Carbon dioxide and character of
fuel 574
— Check-valve action, Lack of syn-
chronism in — Mass, rule change
criticized. Jeter *4S
— Cleveland municipal plant *17. *107,
•373, *463, Records »292, 306, Steam-
generating methods; Delray-type
boilers *631
— Coal, Soft, Hand Firing. Kreisinger t317
— Coals, Chart of boiler performance
with different. Bowles *200
■ — Combustion, Bureau of Mines paper
on. Rogers 413
■ — Combustion suggestion — Iron and
other non-combustibles in fire.
Connor S56
— Compound, U. S. Navy 1655
— Corrosion, Preventing electrolytic
— Cumberland Engineering Co.'s
apparatus 940
— Cos Cob plant; turbine-driven draft
fans with reducing gear *35S
— Court decisons 2S3, 355, 591, 658,
729, 795
— Damper regulator. Electrically con-
trolled. Geare »517, 757, Carples. . 6S6
■ — Dampers would not close. Wight *341
— Dangerous as dynamite — Boilers
under sidewalk with blocked safety
valves, etc 137
— "Defender" boiler-room appliances
— Modified Orsat; draft gage »609
— Detroit pumping station's vertical
boilers *152
— Diagonal joints. Strength — Calcu-
lations for patches. Terman *296,
Grimes, Irvington *485
— Draft gage. Differential. Binns.. 856
— Draft readings, Stirling boiler.
Viall *44
— Draft, Why's of. Hirshfeld »675
- — Drainage of boiler to blowoff.
Slope for 1655
— Driving boilers, burning tubes... 95
— Efficiency, Boiler |5S7, and grate, +311
— Efficiency instruments. Making use
of 5S2
■ — Efficiency kit — Flue-gas analyzer,
etc., Precision Inst. Co.'s . *84
— Evaporation questions $521, 1655,
+ 791, 1S95
— Exhaust-gas heated boiler. Moore »S93
— Exploded, Traction-engine boiler.
Beeman *61S
— Explosion, Heating-boiler, New
Orleans 420
— Explosion, New Bedford — Breath-
ing head 340
— Explosion on "San Diego" 456
— Explosion, Portable boiler «195
- — Explosion, Sawmill-boiler, Beverly,
Mo 2S3
— Explosion. Thornhill Wks.. Eng. —
Overloading safety valves 2S2
. — Explosions. Oas. in furnaces. De
Blois. of Du Pont Powder Co. 553,
Quinn, Bellinger. Scrivenor 651,
Cramer * 71 9, Hawkins 785
Page
BOILER — Continued
— Explosions in first half of 1914 —
Table 140, Ed 25, 130
— Explosions, Probable cause of.... 343
— Explosions, Tear's, British 524
— Feed-water regulator, McDonough
"World's Best" *87
— Feed-water samples. Drawing. ... *6S9
— Feeding. Scientific; regulators;
Jacksonville municipal plant;
charts, etc. Nick *34
— Firebrick for furnaces. Williams,
297, 305
— Firebrick for settings. Heisel *SS3, S90
—Flue, Kinking of 1759
— Foaming from good water 14S7
— Furnace arch, Staying. Hawkins. .'600
— Furnace -change results — Stirling
boilers with Roney stokers at
Detroit. Smith *92, Pond 276
— Furnace linings, etc. — Pottery clay.
Wood 62, Concrete. Sandstrom,
Blanchard 131, Hawkins 169, Ce-
ment. Strong 274
— Furnace system. Morrow — Auto-
matic door-closing device *425
— Gage hand vibrated. AUlrich 27.
Hurst 206
— Graphite in boilers. Weaver 131, .
Bennett, Blanchard 341, Armstrong
484, Feeding. Wiley *616
— Grate, Poillon furnace '499
— Gravity-return boiler, Loss of
water level in 1277
— Heads, Convex, Stresses. Gasche
•59, Mass. formulas 202, Drum
heads. Hogan *450, Finding radius 15S7
— Horizontal r.t. boilers, Supporting
— 3-point suspension. Dean «S4S
■ — Horsepower, The archaic boiler, 167, 179
— Hughes Elec. plant — Burning lig-
nite '732
— Idle boilers. Caring for 3 , j
— Increased plant capacity. Bab-
cock 6S5, Erratum 879
— Increasing capacity — Remodeling
Stirling furnace equipped with
Roney stoker. Harrington *739
— India. Boiler steel required for. . . . 623
— Inspection, Compulsory 379
— Inspection depts., State and local.. 272
— Inspections, Boiler. Moreland.... 756
— Inspector confesses: blowoff valve
opened *319, Garlick 620
— Inspectors' banquet, N. Y 316
— Interborough's 74th St. station;
cooling firebrick, etc. *530, Pigott's
and Stott's remarks on 13.S kw.
per hp 130
— Isolated-plant experience. Binns.. 686
— Isolated plants. Boilers for — Selec-
tion; data design; operation. Hub-
bard 232. Hyde 447
— Joints, Ratio of circumferential to
longitudinal stresses in. Linder-
hurst '611
— Kalamazoo municipal-plant test..*222
— La Salle Hotel plant saving 63, 99
—Lap-seam — How to bring down the
game — ^Cartoon *697
— Laying up boilers. Hudson 517
— Lignite in deep furnace. Morrison 4S5
— Live steam vs. live men — Weighted
safety valve, etc. 410, Conn. Engi-
neer 412
— Locomotive boiler inspection law,
Results of. McManamy SS9, S9S
— Locomotives, Fuel oil for; furnace
arrangements, etc. Bean *900
— Losses, Charts showing. Dreyfus »638
— Lumber Exchange Bldg.'s Scotch
marine boilers *764
— Mass. boiler rules •4S, 202, 242
— Maximum capacity of boiler 15S7
— Menlo, La., explosion. Kirlin *3S2
— Oil burner, Witt rotary crude 'Slo
— Oil from heater got into boiler.
Gibson 62
— Plate, Crushing strength of 14S7
— Plate thickness allowance 1693
— Plate. Watertown Arsenal tests on
diagonal strength of. Macdonald *779
— Plates, Thick. Jeter. Grimes *133
— Pressure, High, battleship "Nevada" 329
— Pumps, Centrifugal. Kessler 133
— Record keeping. White 243
— Repair job. Ingenious — Putting in
new tubes and flue sheet. Kilday *520
— Repairs — "Gun" for pointing up
brick. Abbe *6S5
— Return-tubular boiler front and
back connections. Depth of 1277
— Return-tubular boiler. 9-ft., Dillon. »431
— Return-tubular boilers. Omission
of low-down tubes in +.655
— Riveted joints under stress, Behav-
ior of. Howard 216
— Scranton electric plant — Culm fuel;
double-deck boilers *868
— Seattle boilers for oil or coal *1S2
— Sediment accumulates. Where.... 94
— Setting, Advantages of extended-
front +.277
— Setting boilers with same height
of tubes J349
Page
BOILER — Continued
— Setting, Fire-tube boiler, in small
iso. plant. Wilson *52
— Settings, Low, Disadvantage of... +.521
— Paint, Silica-graphite, for drums. 876
— Smoke-stack connection, Compli-
cated, of two Chicago buildings. . .*643
— Soda ash for scale 1135
— Soot 23S, Removal. Blessing, Prie-
fer *615
— Soot conveyor, Schutte & Koerting.*876
— Specifications, Uniform, A. S. M. E.
— Review 25, Approved by council;
portraits of committee '268, 271,
Adopted by Ohio 526, Mich, situ-
ation 717, Elsewhere 6S2, Difficul-
ties 54S, Boiler Mfrs.' discussion
896, Safety valves SI, 241, 380
— Standing boiler. Care of 1209
— Steam, Cost of. Strong 133, Howard 273
— Steam costs in 6600-hp. plant and
methods of obtaining. Philo 36S
— Steam generation in wood-distill-
ing plant. Eddy '846
— Steam-main and stop-valve ar-
rangement ±209
— Steam quality near surface 1102
— Stoker- and hand - fired . boilers,
Comparative tests of, Norton Co.'s.
Knowlton *300
— Stop valves, Powell »127
— Superheater, Evap. factor with.... 131
— Test, Hydrostatic. Quizz 257
— Test reports. Simplifying. Pearce. 97
— Test, The practical man's 168
— Testing — Hydrostatic — Note 747
— Tests — Loss by use of slack. Biehl 208
— Toronto E. L. Co.'s boiler and
stoker test from banked fire 73
— Trapped in boiler, in steam 806
— Traps. Return, for feeding. Gil-
bert »467
— Tube ferrules, Use of 1587
— Tube heating-surface formula 294
— Tube fittings by fatty acids 1102
— Tubes, Bursting, and forcing boil-
ers. Kent 98, Nelson 384
— Tubes, Holding power of 848
— Tubes, Rerolling of 1311
— Tubes. Side, blistered; blowoff pipe
open at one end. Binns *59
— Tubes, Wrought-iron and steel.
Stewart 523
— Tubular and water-tube boilers,
Retubing. Hawkins »330, Schap-
horst 586
— Union Brewery plant. Wilson *662. 820
— United Piece Dye Wks. — Connect-
ing two old boiler plants; equaliz-
ing steam lines. Collins *28S, Er-
ratum 401
— Water column, Queer action in.
Jorgensen '787
— -Water-tube boilers, Putting new
headers in. Gray 649
— Western Newspaper Union plant,
Chicago — Moving boilers *2
— Westport plant addition, Baltimore. *390
— Working pressure for oil boiler .. .1385
— Tear's review 22, 25
Boise Federal power house. Connor. *594
Bolt, Holding power of. Fish *619
Bolt tension increase after cooling. .1555
Rooks, Varnish for protecting 45S
Booster-pump test, Chicago *33S
Boring out crank. Cunningham *653
Boston Edison rate schedule *549
Bourdon gage tube action $*895
Bowles. Coal-purchasers' chart *200
Braking, Regenerative. N. & W *830
Braley. The transmission line «249.
That peak-load problem «S67
Brame. Factors affecting commuta-
tion »836
Brewery, Stifel Union, boiler plant.
Wilson *662, 820
Brick. "Gun" for pointing up *685
Brine gage. Recording, Boston »9
Brine pump. Good service from. Inde-
pendent Packing Co.'s *304
Rrinton. Graphic Methods 1388
British boiler-explosion statistics... 524
Bromley. Quincy Market refriger-
ating station. Boston *9, Seventy-
fourth St. station and its turbines
•528, 547, Steam turbines, their
principle and operation »626, 789
Bronzes. Three-metal 373
Brooklyn engineers give play (1^1
Brooklyn school gas-engine accident 203
Broom handle in pipe. Woodruff. . . . 725
Brown. Air in jet-condenser practice
404. Storage batteries for peak
loads *470
Brownhoist coal-weighing larries... *17
Brush. Carbon, troubles. Martindale . '558
Brush tension. Adjusting — Note 93
Bubblers, Piping, to avoid waste.
Henry 486
Buckeye printers' engine *65
Buffalo transformer blower. Large.. *533
Building, Tenant, power costs. Win-
ter 406
Bumped-head stresses. Gasche *59,
M.nss formulas 202, Drums. Hogan
•450. Finding radius 1587
"Bumped heads," Formulas for. Aine r.17
January 1 to June 30. I'M.
P 0 AV E R
Page
Bunnell. Low-grade fuel 378
Bureau of .Mines t2;>2, f284, f317, T318,
T796, Paper on combustion dis-
cussed. Rogers * 4 1 3
Bureau of Standards — Fixing horse-
power 343, Aneroid calorimeter i '. ^ L' .
Elec. safety code 717, Radiation
pyrometers 882
Burr Evans motor 4U7
Bus room, Safeguarding 646
Butler. Oil Fuel fl48
C
Calipers, Telephone receiver con-
nected to. Carr «621
Calking pipe leaks. Hawkins 689
Calories, To convert B.t.u. to 77U
imeter, Aneroid. Dickinson,
Osborne 622
Calorimeter, Separating, Quality of
st.am by f.823
Candid chats 'lsi, »389, »76S
Cannon, Horsepower of 511
Canton portable tloor crane *574
rews, Replacing broken. Sol-
omon *414, Johnson, Mellen 553
Car for inside of boilers. Chrisman '647
Carbon dioxide. See also "Gas, Flue,"
"Boiler."
Carbon dioxide and character of fuel.
Reardon 574
Carbon dioxide and monoxide, Rela-
tive heat of J487
.Carbon-dioxide apparatus, Defender. «609
Carbon-dioxide chart — Losses *638
Carbon-dioxide refrigerating ma-
chines. Wittenmeier 490
Carbon-dioxide Thermoscope, Tag-
liabue 43
Carburetion trouble. McClinton . . . .'275
Carburetion Troubles, Location of —
Chart. Page t865
"Carburetor," Franklin cylinder-oil. *674
Carhart. Safety-valve specifications
81, 241, Safety-valve discussion... 509
Carpenter, R. C. Heating and Ven-
tilating Buildings 1624
Carpenter Steel Co.'s steam-turbine
rolling-mill drive 455, 541
Case-hardening governor pins {587
Catalog size, Uniform. Brown 821
Cement for leather 532
Cement furnace linings, etc. .131, 169, 274
Cement grouting under heavy ma-
chinery 310, 482, »620, 7S6
Cement surface treatment 291
Centennial engines *250, *302, *376
Central station and refrigeration.
Cochrane 489, Loyd 490
Central-station conditions — Data of
large plants — Martin's report to
N. E. L. A 827
Central station, Diesel-engine, Win-
chester, Ind. Wilson »562
Central station vs. isolated plant:
See also "Power plants."
— Am. Mfg. Co. buys power 380
— Govt, as power buyer 636
— Isolated-plant experience. Binns. . 686
— Motors to put engines out of busi-
ness. Banger »742
— Netherlands commission report... 582
— Play by Brooklyn engineers 681
— Rates, Reasons for different: ice-
selling example *3S3, 550, 684
— Year's review 25
Centrifugal pump. See "Pump," "Air
pump."
Champion oil burner «7
Chart. See also "Diagrams."
Chart, Coal purchasers'. Bowles. .. .'200
Chart, Internal-combustion engine
dimension. Watson *672
Chart. Stovel-Carle wiring *667
Charting the plant 410
• 'harts. Ammonia-compressor power.*158
Charts, Power-plant loss. West Penn
Traction Co.'s Dreyfus *638
Chatain. Eight-cylinder gaso. engine. '214
Check-valve action. Lack of synchro-
nism in. Jeter *48, McNabb 242
Chemist, Fireman as. Palmer 65
Chicago — Commonwealth Edison's
large surface condenser *474
Chicago Federal Bldg. plant, Saving
in 610
Chicago, Mil. & St. P. electrification 72
Chicago. Roseland pumping station,
Test of booster pumps. . »338
Child-labor laws. Hawkins 851
Chimney. See also "Stack."
Chimney area. Proportioning 706
Chimn-y. Brick, which floats. Schlich-
ter Jute Cordage Co.'s *940
Chimney crack from expansion of
lining 1S23
Chimney. Leaning, plumbed. Clark.. *40S
Chimney. Razing a brick »374
Chimneys for oil- and coal-burning
plants. Rosecrants 637
Chimneys, Reinforced-concrete, Ha-
vana »166
Chittenden hydro-elec. plant. Fraher.*494
Chorlton. Convertible combustion
engines «556
Circuit-breaker, Automatic reclosing.
Raney •! 08
Page
Circuit-breaker, Larue, Wood -Mills. '30
Circuit-breaker, 20,000-amp *777
Clark. Leaning chimney plumbed. .'408
Classification of technical literature,
Clay, Pottery, in fireclay sen
Wood
Clean new steam lines. Strong
Cleanliness in refrigeration plan I
ice. Cylinder and piston J693
Clerk super-compression engine * r, r. 7
Cleveland Elec. 111. Co. feeder acci-
dent— Repair *73
Cleveland municipal elec. plant. Bal-
lard '104, Coal-weighing larries
•17, Feeder accident 109, Keeping
of operation. Williams *292,
306, Concrete blowoff basins. Wil-
liams »373, Piping and supports.
Williams •463, Steam-general
methods. Williams '631
Cling -Surface, Fluid 600
Clutch, Akron "Ideal" multi-cone. .. *533
Clutch, Dodge safety self-oiling. .. .*801
Clutch shifter, Hilliard rack-and-
pinion '706
C02. See "Carbon dioxide," "Gas,"
"Boiler."
Coal, Air for burning (27
Coal, Alaskan 216
Coal Analysis with Phenol as Sol-
vent. Parr, Hadley tl4S
Coal, Anthracite, in early days 327
Coal — Ash content influence. Ellis,
Hubbard 654
Coal bunker with air-operated gates,
Cleveland »631
Coal, Burning bone — Bessemer C. ,v
C. Co.'s boiler plant *798, 817
Coal — CO» and character of fuel.
Reardon 574
Coal calorific-value calculation 1521
Coal constituents, Variation in, for
similar B.t.u. values. Jackson.... 441
Coal-conveyor engine. Stop valve on.*!>40
Coal crushers, Belt-driven, Brooklyn
Edison's 197
Coal — Culm burning, Scranton "stJ^
Coal, Finding value of. Dunkley 29,
Hubbard 206
Coal, Firing low-grade. Bunnell.... 378
Coal for power plants, Easy calcula-
tion of. Horton 622
Coal — Fuel economics 167
Coal, Future methods of utilizing.
Hirshfeld 488
' loal 'ias Residuals. Wagner t560
Coal handling, Norfolk & West.
power station *830
Coal, Lignite, burning, Hughes plant. *732
Coal, Lignite, in deep furnace. Mor-
rison 485
Coal-mine plants. Rogers *160
Coal, Powdered. Robinson 793
Coal production, U. S 600
Coal progress — Year's review 23
Coal, Purchase of. Smith *235
Coal purchasers, Chart for — Boiler
performance with different coals.
Bowles «200
Coal purchasing on B.t.u. basis 130,
Brownell 131, Newton 273
Coal required, stated conditions 1209
Coal-saving (?) dope 201, 216
Coal, Slack, Loss by use of. Biehl.. 208
Coal, Soft. Hand Firing. Kreisinger. 1317
Coal-storage tests, Navy 193
Coal, Sulphur in — Objections $521
Coal-test reports, Government 645
Coal tests, Govt, printing plant *57S
Coal, the big item 165
Coal tonnage used for coke 536
Coal, Too much — Candid chart *181
Coal-weighing larries, Brownhoist,
Cleveland '17
Cochrane multiport flow valve '508
Coils, Oxyacetylene-welded «S10, 817
College work. Practical 850
Collins. Steam-pipe installation *288,
Erratum 401, Horsepower con-
stants for steam-flow meter *773
Colorado River Basin t580
Columbia Plate Glass Co.'s turbine
and condenser outfit *295
Columbus municipal-plant decision.. 354
Combustion. Bureau of Mines paper
on. Rogers *413
Combustion chamber. Gas-engine,
Repairing crack in. Linker 30S
Combustion, Rate of 539
Combustion suggestion — Use of iron
bars. Connor 856
.wealth Edison's large sur-
face condenser *4 , 4
Commutation, Factors affecting.
Frame »836
tator holes. Filling. Pollard. -*690
Commutator repair, Quick. Crane. . *51S
Commutator short-circuited. Horton 2ns
Commutator troubles. Martindale. . . «558
Commutators. Emery around. Op-
penheim 27".
Commutators, Lubricating. Cummings 586
Commutators, Roughening, gilding,
oiling S4. 96
I o pensation acts, States having. .1759
Compensator, Open-circuited Wiley. *617
Compounds. Coal-saving 201, 216
Page
Compression, Units of +.349
-soi. Air. See "Air," "Blow-
ngine." „ ..„ „ •
Compressor, Ammonia. See Refrig-
eration."
Concrete, Anchoring foundation bolts
■ roft *841
Concrete filling for engine beds and
Salmon "■< l
I loncrete furnace linings, etc. 131, 169, 274
aion from waterwheel cas-
Swaren 722
Condensation in hot-blast heaters.
'128
Condensation meter. Simplex '569
Condenser, Ammonia, plant, Boston,
•11. '13
CONDENSER, STEAM
See also "Cooling tower," "Pump,"
"Air pump," "Power plants."
— Air from condensers. Removing.
Caywood *723
— Changing engine to condensing. .. 1759
oil Edison's traveling screens. *333
— Ejector condenser, Deane *546
— Gage, Tide-water, Boston *9
-Interborough turbines *527, '531
— Jet-condenser practice, Air in.
Brown 404
— Jet condenser, Large, Baltimore,
•20. '391
— Pipe cracked and repaired. Sword. '648
— Scranton electric plant *S69
— Setting, Novel, in intake canal, La
Habra Val. Water Co.'s. Clark... *29
— Surface condenser, Commonwealth
Edison's large Wheeler »474
— Tube corrosion, Australia. Bates 355
— Tube corrosion. Inst, of Metals.. 559
— Turbine and condenser outfit.
Mixed-pressure, Columbia Plate
Glass Co.'s '295
— Turbine vacuum effect *312
— Turbines, Small condensing. Lon-
don *426
— Vacuum chart showing losses. .. .*638
■ — Vacuum helps in repairs. Hurst.. 486
— Vacuum most economical for tur-
bines. Herschel *744
Condensing coil on oil feed. Reed..*647
Connecticut water resources 246
Connor. Minidoka Federal project
•422. Boise Fed. power house '594,
Govt, as power buyer 636
Conservation of energy 103
Conservation, Water-power 57, 72,
129, 144, 246, 445, 480, 514, 5S2, 752, 863
Consol. G., E. L. & P. Co. plant *390
Consulting and operating engineers 479
Consumers' Bldg. stack connection . '643
Contactor closed and opened. Horton. '208
Converter, Rotary, Effect of lightning
on. Swift »97
Converter station. Aluminum Co. ...*776
Convertible combustion engines.
Chorlton «556
Convex-head stresses. Gasche *59,
Mass. formulas 202, Convex and
concave drum heads. Hogan '450,
Finding radius $587
Cook. Interior wiring *601, *640,
•666, 702, 736, 891
Cookson return steam trap '588
Cooler, Vacuum fluid *542
Cooling pond. Making spray, Rea
Patterson Milling Co.'s. Blair. .. .'Sie
Coooling tower, Home-made, at Wil-
lard factory. Williams #S47
Cooling tower on concrete posts. .. .'113
Cooling towers. Forced-draft. Good-
rich *121
Cooling towers, Scranton — Combined
fan and natural-draft *869, Large
Balcke natural-draft 'S70
Cooling water. Gas-engine — Recool-
ing arrangement. Field '438, Mor-
rison 583
Core loss in series motor. Robie . . . .*771
Corliss. See "Engine, Steam," "Gov-
ernor," "Valve."
Corrosion, Condenser-tube. Bates.. 355
Corrosion, Condenser-tube. Inst, of
Metals 559
Corrosion, iron and steel pipe. Sand-
strom 416. Dunkley. Noble 584
Corrosion of steel uptake 1655
Corrosion of wrought-iron and steel
tubes Stewart 523
Corrosion, Preventing electrolytic
'■Oiler 940
Corrosion — Steel pipe best 848
-ion Rogers. ... *3."S
Sanitary Refrigeration
and I.. Makl'ne.. +388
See also "Power plants," "Iso-
lated plant." "Rate." etc.
Cost of emnlovin" incompetents.... 726
Cost of steam. Strong 133, Howard 273
Chi. Federal plant 610
Costs in small industrial power
plant Thayer 465
Costs. Initial and operating, of re-
frigeration plants Kehoe 710
Co«*ts, Power, in tenant building.
Winter 406
Costs. Relative, of steam and hydro-
electric power 246
POWER
January 1 to June 30, 1915
Page
Costs, Specifying unit station 95
Costs, Steam, in 6600-hp. boiler plant.
Philo 368
Coupling made into pulley. Strother 134
Coupling, Quarter-turn rod, Hall's
•117, Schloss 310, McClure, Sand-
strom 683
Cournon steam meter *545
Court decisions. Recent. Street 109,
144, 283, 355. 457. 591, 658, 694,
795, Engineering points in them.. 237
Covering, Cheap steam-pipe 50S
Covington. Recedence and pressure
readings from submerged pumps. *473
Cox's Commercial Calculator t45S
Crack in combustion chamber, Re-
pairing. Linker 30S
Craft. Steam-line specifications.... 612
Crane and hoist. Canton portable
floor «574
Crane, Operating locomotive Honey. *41]
Crank bore. Enlarging. Cunning-
ham *653
Crank disk. Loose — Question. Jensen
•654, Cultra, Hurst, Sword, White 819
Crankpin failure. Jorgensen *720,
Cox. Williams. Haynes 853
Crankpin position, half stroke ±,587
Crankpin troubles. Haynes 12n
Crankpin, Vertical, Nugent central
oiler for *735
Crankshaft, End play of JoST
Croft. Anchoring foundation bolts in
concrete *S41
Crosshead, Removing piston from.. 651
Cuba, Am. engineer in. Small S3
Culm burning. Scranton «868
Cumberland Engineering ( 'o.'s anti-
corrosion apparatus 940
Cummings compressed-air practice.
Richards *224
Cutoff unchanged, speed increased. . 1693
Cutout. Low-gravity, for storage
battery. Dixon .*720
Cutting down steel stack with oxv-
acetylene *SSS
Cycles, Heat-engine *173, Steam-en-
gine *210
Cylinder danger from sudden over-
heating 1655
Cylinder-head packing. Kolar 61
Cylinder-head repair aboard ship.
Dobson «691
Cylinder lubricator. Phenix oil and
graphite *780
Cylinder-oil "carburetor," Franklin . «674
Cylinder, Oil-cushion, supply. Dear-
born «75S
Cylinder ratios. Air-compressor. Sal-
mon «472
II
Damper regulator. Electrically con-
trolled. Geare *517, 757, Carples... 686
Dampers would not close. Wight... *341
Danger signal, Metal. Skinner *855
Dash pot. Hood over. Strong «S92
Dates to remember 306, Williams. . . . 414
Davies. Electric-motor noises *572
Dayton power pump «165
De Laval turbine for steel mill 455, 541
Dead-man broke *139
Dean. Supporting horizontal r.t. boil-
ers »848
Deane ejector condenser *54fi
Deaths, Notable, in 1914 26
Defender boiler-room appliances. .. .*609
Delray. See "Detroit Edison."
Dents, Removing, from tanks, etc.
Connor 822
Depreciation as practical problem... 445
Design. See "Power plants."
Details, Principles vs 751
Detroit Edison's traveling screens
•333, Connors Creek plant 3S6
Detroit Engineering Society 522
Detroit municipal pumping stations.
Wilson «15n
Detroit sewage-pumping station. .. .*286
Detroit United Ry. — Furnace change,
Diagonal-joint strength. Terman
•296, Grimes, Irvington »485
Diagram. See "Indicator." "Chart."
Diagrams, Steam-turbine. Low »596, »650
Dickinson. Specific heat and heat of
ice fusion 565, Aneroid calorimeter 622
Die stock, Borden "Beaver" cross-
bar .644
Diesel-engine central station, "Win-
chester. Ind. Wilson »562
Diesel engine. Palo Alto. Haas *502
Diesel-engine rating. Tookev 564
Diesel engine, Southwark-Harris. . .*877
Diesel-engine tendencies. Ward *1S6,
Wentworth 3S3, Correction 484,
Crowly 413
Diesei engines — Year's review 23 24
Diesel princinle applied to small en-
gines, A. E. G 's »162
Dillon return-tubular boiler ...»431
Dinkel steam trap *644, 795
Direct-current machines, Changing
the service of. Fox 298
Direct-current vs. 3-wire systems
Fox «505
Page
Distilling with gas-engine exhaust.
Hayes *205
Dodge safety self-oiling clutch *S01
Dollars produce. Making the 614
Don'ts for refrigerating engineers.
Thurston 607
Dooley. Vocational Mathematics . . . . 1 796
Dos Estrellas turbine plant *192
Draft, Boiler, Why's of. Hirshfeld. .*67B
Draft control, Cleveland municipal. *632
Draft gage, Defender "duplex" *609
Draft gage, Differential. Binns 856
Draft gage, Ellison combination dif-
ferential »229
1 iraft loss in flues and elbows ±.521
Draft loss minimized, Union Brew-
ery *662
Draft readings, Stirling boiler. Viall *44
Draft-tube water-hammer. Crane. .*789
Drain pipe. Cleaning — Pneumatic
stopper. Reardon *724, Noble.... S22
Drains above back-pressure val
Reynolds 205
Drawings, Isometric. Hampson *7S5
Dredge pump handles ashes. Havard.*580
Dreyfus. Power - plant appearance
13S, Graphic representations of
power-plant losses *63S
Drinking bubblers, Piping. Henry.. 486
Drop factors, Table of 705
Drum heads. See "Heads."
Dry batteries. Protecting 411
Du Pont Powder Co.'s gas explosion 553
Ductility, Measure of ±,555
Dunkley. Salesmen's reply *731
Dunston station extension 354
Durand. Heating and ventilating
Am. Cigar Co.'s plant *460, 541,
Vacuum heating systems 605
Dynamite. Dangerous as 137
Dynamo. See also "Electricity."
Dynamo, Starting old. Miles 6SS
E
Eccentric, Reversing, with same an-
gle of advance ±823
Eckel hydrostat feed-water regu-
lator «466
Economizers, Cleveland municipal
plant «633
Eddy. Steam generation in wood-
distilling plant «846
Education, Definite engineering 850
Education. Engineering — Bklyn. play 681
Education, Industrial. Fish 207
Educational aid to engineers, Kansas
784, Oregon 850
Efficiency engineering 446, Hoffecker 585
Efficienev instruments. Making most
of 582
Efficiency, Pre-. Willis 500
Efficienev, Theoretical, of heat en-
gines. Heck »534. Gasche «753
Ejector condenser, Deane *546
Ejector, Steam. Maximum lift of.
Purcel], of Penberthy Injector Co. 615
"Elbow room" in power-station de-
sign 547
ELECTRICITY
See also "Rate." "Power plants"
and cross-references from it. For
hydro-elec. plants see "Water
power."
— Advanced Electricity and Magnet-
ism. Franklin. McNutt f624
— Air gap. Unequal, caused by shims.
Justus «619
— Alternator, Large, Efficiency test,
coupled to waterwheels. McDou-
gal 86
— Am. Inst. Elec. Engineers' conven-
tion, etc 316, *491, *5S9, 657
— Armature winding, D.C. Gintz. . . .*335
— Auto-transformers. Meade *804
— Balancer set. Gas-tractor power
plant with. Hull »226
- — Battery. Storage, and its limita-
tions. Dawson 821
— Battery, Storage, Low-gravity cut-
out for. Dixon *720
— Battery, Storage, notes 1102, 301
— Batteries, Dry, Protecting 411
— Batteries, Storage, Charging small.
Miles »757
— Batteries, Storage, for peak loads.
Brown *470
— Brush, Carbon, troubles. Martin -
dale »55S
— Bus room, Safeguarding 646
— Chi., Mil. & St. P. 3000-volt d.c.
electrification 72
— Circuit-breaker, Automatic reclos-
ing. Raney *10S
— Circuit-breaker, "Wood Mills '20
— Cleveland municipal light plant.
Ballard *104, Coal-weighing larries
•17. Feeder accident 109, Keeping
track of plant operation. Williams
•292. 306, Concrete blowofE basin.
Williams «373, Pining and sup-
ports. "Williams *463. Steam-gen-
erating methods. Williams *631
— Cleveland Elec. 111. Co. feeder ac-
cident— Temporary feeders *73
ELECTRICITY — Continued
— Columbus municipal light plant.. 354
— Commutation, Factors affecting —
Armature reaction; induction in
commutated coils; local currents
in short-circuited coils; selection
of brushes. Brame *836
— Commutator holes, Filling. Pol-
lard «690
— Commutator repair. Quick. Crane. *518
— Commutator short-circuited. Hor-
tbn 208
— Commutators, Lubricating. Cum-
mings 586
— Commutators, Original ideas with,
84, 96
— Compensator, Open - circuited.
Wiley «617
— Conductivity and resistance 643
— Contactor closed and opened. Hor-
ton *208
— Converter, Rotary, Effect of light-
ning on. Swift *97
■ — Converter station. Aluminum Co...*776
— Cos Cob plant, N. Y., N. H. & H.
R.R «35S
— Direct-current machines, Chang-
ing service of — As generator or
motor. Fox 298
— Direct-current vs. 3-wire systems;
motor-generator sets. Fox *505
— Dynamo, Emery around — Use on
commutators. Oppenheim 275
— Dynamo, Starting old. Miles 688
— Electromagnets for alt. -current
circuits. Meade *14. Correction.
.Tacobi 203
— Elementary Electricitv and Magne-
tism. Franklin, McNutt t660
— Elevator dispatcher, Automatic.
Meade *540
— Elevator, Elec. traction. Linquist. 656
— Fault localizer, Portable "Westing-
house »350
— Field coils. Reversed. Parham . . . . 892
— Field connections, Neglected to
change. Eismann »242
— Generator bearing. Hot; unequal
air gap. MeClinton »S51
— Generator, Belt-driven, Realigning.
Walchli «892
— Generator ground circuit. Connect-
ing ±'102
— Ground, Puzzling — Booster trouble.
Thurston *342
• — Harrisburg, 111., railway and power
plant. "Wilson «698
— Heating of conduits containing
wires of polyphase circuits {385
— Human energy in elec. units 326
— Insulation resistance, Maintain-
ing; machinery subject to fumes;
varnishing by compressed air. Mc-
Lellan »365
— Kalamazoo lighting plant. Wilson. *218
— Kilowatt-hour substitute suggest-
ed— The "kelvin." Wallis 172
— Lamp and fuse tester. Sheridan.. *61
— Lighting plant, Opelousas' muni-
cipal *41
— Lightning arresters. Raitt, Good-
win *483
— Lights, Flickering. Horton '205
— Locomotive, Elec, discussed by
Chicago A. S. M. E 729
— Meter accuracy. Watt-hour. Ewing 244
-Minidoka irrigation project — Govt,
furnishes cheap electricity. Wal-
ker 22S, Connor *422
— Motor and waterwheel drive,
Flour-mill 492
— Motor. Changing speed of 3-phase
induction. Bankhead .»583
— Motor data. Listing 514
— Motor gear ratio changed. Horton 276
— Motor had one terminal. Horton. *240
— Motor, Induction, Changing speed. 1349
— Motor, Induction — Peculiar acci-
dent Smalley 855
— Motor noises. Davies '572
— Motor operating cost ±31
— Motor records again 784
— Motor, Series, Core loss in — Test
with motor-dynamometer. Robie.*771
— Motor. Shunt, Running as dynamo
— Speed + 349
— Motor, Starting small. Griscom *60,
Strong 308, Fredericks 345
— Motor. Synchronous, control in
Jenckes Spinning Co.'s low-pres.
turbine plant 478
— Motor, Wrong voltage on. Horton 267
— Motors, D.c. Speed characteristics
of. Bennett «125
— Motors, D.c, Why they fail to start;
locating faults; use of water rheo-
stat for starting, etc Annett *194,
*230, Testing for open circuit.
Plimpton 452
— Motors, Fractional-hp.; speed-
torque curves, etc. Lester •5S9
— Motors, Notes on alternating- and
direct-current. Fredericks 891
— Motors, Starting torques of 1S23
— Motors to put engines out of busi-
ness. Banger '742
January 1 to June 30, 1915
Page
ELECTRICITY — Continued
— Natl. Elec. Lt. Asso. — Reports on
prime movers, etc. 582, 858, Cen-
tral-station conditions S27, Con-
vention at the Exposition *S5S
— N. T. subway accident, High-ten-
sion feeders cause 74
— Norfolk & Western electrification
— Power station; locomotives; re-
generative braking, etc '830
. — Oil switches. High-voltage, Gen-
eral Electric series trip for *304,
Crane 484
— Pumps, Automatic electric control
of. Kirchgasser »811
— Rate. See also under thai head
— Rates, Electric-light. Chandler... :1T
— Rates, Mass., discussed 282
— Resistances, Connecting. Horton.*649
— Safety code. National 1 17
— Scranton electric plant. Rogers. . «S6S
— Seattle municipal lighting plant.
Kidston *ls2. News notes 71, 387
— Ship propulsion, Elec. Emmet.... 657
— Short-circuit in alternator field... $417
— Signal - circuit make - and - break,
using mercury. King *725
— Starter, Burned-out. Horton *585
— Stator connections. Wrong, of mo-
tor driving compressor for whistle
blowing. Horton 893
■ — Switch, Motor-operated, elec. -fur-
nace '20
— Switchboard lugs, Home - made.
Gerber *75S
— Switchboard with vertical-type cir-
cuit-breakers, Lumber Exch. Blrtg.«769
— Switchboards, Development of; dif-
ficulties in old days 70S
— Switching systems, High-tension.
Randolph *434
— Tower. Transmission, blown down.*687
— Transformer blower. Large Buffalo. *533
— Transformer connections. Some —
Testing polarity: obtaining voltage
combinations, etc. Fox *46, Fred-
ericks *3S1
— Transformer, Constant - current.
Randolph *153
— Transformers, Designing small.
Meade *262
— Tungsten-lamp dimmers. Waller. *491
— Wire resistance and temperature. 1102
— Wiring, Interior, for lighting and
power. Cook — Natl. Elec. Code
rules; choice and arrangement of
lamps *601, Branch circuits, fuses,
panel-boards, switches, etc. '640,
Formulas and wiring chart for
D. C. circuits; arrangement of
branch circuits and feeders; A.C. 2-
and 3-pnase systems *66G, Power
circuits: motors: control devices:
load: voltage drop. etc. 702. Power
panel-boards and systems 736, Dis-
cussion. Fredericks S91
— Year's review 24
Electrolytic boiler corrosion, Pre-
venting 940
Electromagnet. See "Electricity"
Elevator dispatcher, Automatic elec-
tric, Insurance Exchange Bldg.,
Chicago. Meade *540
Elevator-door safety devices. Osborn 345
Elevator, Electric. Racing of $135
Elevator, Elec. traction. Linquist... 656
Elevator-pump notes. Rogers *741
Elevator-rail greaser, Garvens' *82
Elevator salesman's tricks. Harris.. 50
Ellenwood. Steam Charts fl48
Elliott strainer *S
Ellison combination differential draft
gage *229
Emery around dynamo. Oppenhejm. 275
Emmet. Elec. ship propulsion 657
Employing incompetents. Cost of . . . . 726
Employment offices. Federal 590
"Empress of Ireland" damages 47S
Encouragement 58
ENGINE, INTERNAL-COMBUSTION
— Accident, Peculiar gas-engine.
Brooklyn school. Johnson, Lent,
Strom, Carpenter 203
— Backfiring trouble $555
— Carburetion trouble. McClinton . . '275
— Carburetion Troubles, Location
of — Chart. Page t865
— Combustion chamber. Repairing
crack in. Linker 308
— Convertible combustion engines.
Chorlton »556
— Cooling water — Recooling arrange-
ment. Field »43S, Morrison 583
— Diesel engine, Kbrting. Palo Alto.
Haas »502
— Diesel-engine rating. Tookey.... 864
— Diesel engines. Busch-Sulzer — Cen-
tral station, Winchester, Ind. Wil-
son '562
— Diesel principle applied to small
engines, A. E. G.'s *162
■ — Dimension chart, Internal-combus-
tion engine. Watson »672
■ — Distilling with exhaust. Hayes... *205
— Efficiency of heat engines 136,
Cycles «173
POWER
Page
ENGINE, INTERNAL-COMBUSTION—
i 'ontinued
— Efficiency, Relative, of steam, gas
and oil engines 103
— Efficiency, Theoretical. Heck *o34,
Gasche *753
— Eight-cylinder gasoline engine tor
railway traction. Chatain *214
— Exhaust-valve replacement, Inde-
pendence. Kan., plant 473
— Forty years' advance *376
engine cylinder. Heat distri-
bution in — Dundee experiments.
Gibson, Walker *824
— Gas-tractor power plant. Hull. . . .*226
— Gasoline Engine, How to Run and
Install. Von Culin t317
— Gasoline engine run on natural
gas — Question. Gawthrop 654,
.Morrison, White 821
— Gasoline-engine test. Hawley . . . . *485
— Housing. Repairing gas-engine.
Griffin *788
— Ignition systems, Spark-plug.
Israel '258
— Kerosene engine, Lauson heavy-
duty *H6
— Mesta blowing engine, Large *39o
— -Oil engine for off-peak load. Mor-
ris *351
—Oil engine, Hot-bulb. Lundgren.. «79
— Oil-engine jacket, Removing scale
from. Morrison S56, Air compres-
sor. Hendry '787
■ — Oil engine. Marine, Thermodynam-
ics of. Wentworth *145
- — Oil-engine tendencies; defects of
low-compression, pump-injection
tvpe with heavy oils; vaporizing
type favored. Ward *1S6, Went-
worth 383, Correction 4S4, Diesel
engine defended. Crowly 413
— Oil-engine test, Petter 16-hp. Sal-
feld 405
— Opelousas' municipal oil-engine
lighting plant '41
— Piston-fit allowances, Automobile.
Weaver *245
— -Piston trouble, Oil-engine. Griffin 650
— Sou thwark -Harris Diesel engine
with stepped pistons for starting
and scavenging *S77
— Start. When gas engine will not.
Percy 299
— Sulzer Diesel engine. Large 636
— Test of 200-hp. gas-producer plant
by Lehigh Univ. Larkin 6
— Year's review 23, 24
ENGINE, STEAM
See also "Governor," "Piston,"
"Cylinder," "Crankpin," "Valve,"
"Stuffing-box," "Indicator," "Power
plants," etc.
— Air, Compressed. Engine operated
with. Reed *621
— Aligning with calipers and tele-
phone **^1
— Brake power of engine 417
— Centennial Corliss and Columbian
fair engines *250, *302
— Compound condensing engine, why
more efficient than simple? 539
— Concrete-filled beds. Salmon *94
— -Condensing, Changing to $759
— Connecting two engines to same
receiving shaft $349
— Corliss engine, Long-range cutoff
for $791
— Corliss governor compensators.
Stewart 415, Bascom *S94
— Corliss valve-bonnet repair. Pow-
ers '552
— Crankpin troubles. Haynes 120
— Dash pot, Hood over. Strong *S92
— Economy, Relative, with increase
of speed $349, With different initial
pressures $895
— Efficiency of heat engines 136,
Cycles ." *173, "210
— Efficiency, Relative, of steam, gas
and oil engines 103
— Efficiency, Theoretical. Heck *534,
Gasche *753
— Exhaust line, Common, for several
engines $31
— Governor. Blocking up. Richards,
•347, Terman 482
— Governor-stop control and belt
tightener *S
■ — Hoist, Large compound condens-
ing *386
— Karpen plant engine. Ed. 26, Mor-
rison, Wilson 27
— Locomobiles. What causes the high
efficiency of? Pearce 633
— -Lumber Exchange Bldg.'s poppet
4-valve engines '764
— Marine engine, Small compound.
Roger *191
— New vs. second-hand. Blanchard. 134
— Nordberg engines, Two new — Pop-
pet-valve uniflow and counterflow'llS
— Oil-cushion cylinder supply. Dear-
born *75S
— Oiling system, Nugent.. *90, »436, *785
— Pipe sizes— Chart. Salmon »8S
Page
ENGINE, STEAM — Continued
—Portable engine, Long chances
with. Addy : • • ■ • sl*
-Pressure for running noncondens-
jnK $000
—Printers" engine, Self-contained
Buckeye. McConnell • • »»
—Pumping engines, Moving, bV,
water pressure. '•>«
— R.p.m. to develop 1000 hp. ........ .$385
—Rolling-mill engine wrecked, Ches-
ter W Va lsu
—Safety 'devices — Anecdote. McQuxl-
^in *> •
—Safety devices, Testing. Macking. 134
—Setting 4-valve engine. Vnegand.*266
— Steam pressures, flywheel risks,
piston speeds 54s, Williams 585,
Jones
— Stop acts' when rod breaks, Per-
kins factory • ■••• *'"
— Test of 200-hp. gas-producer plant
by Lehigh Univ. Larkin . . . . . . *>
— Traction-engine boiler exploded.
Beeman • •„•„• »"
— Una-flow engines, American .... a, io<
—Uniflow engine, Recent develop-
ment in — Sulzer's Stumpt •39b,
Auxiliary exhaust valves. Skinner,
•448, Turnwald ■ • blb
— Uniriow or una-flow 201, Trump... 482
— Uniflow plant, First, on Pac. Coast
— Universal engines in New Roslyn
Hotel, Los Angeles ......... i4i
— Uniflow steam engine — Principles. *570
—Vacuum, Satisfactory average.
Srciith o4i
—Valve, "Ball engine, Reseating.
Jann6t &io
— Valve stem, 'Twisted, Diagram cor-
rection for. Kjerulff ■■■■■■ »»
Year's review &*•% ~"*
Engineer at public hearings 409
Engineer— Extra man's value bt
Engineer needs judgment....... *&'
Engineer, Night, off duty. Losh.. .. 205
Engineer, Old, Why he lost his job.
Harris • • • *lb
Engineer— Taking charge ot larger
plant • • • • • ■ ■ .'ii
Engineer, The loahngC?) . . i«>>
Engineer, The plodding. Quizz b
Engineer's life story •••■.-■• °i*
Engineering — Choosing a profession 581
Engineering Congress. See Pan-
ama-Pac." efi
Engineering Economics. Fish . . . . . t660
Engineering education — Bklyn. play bSl
Engineering education. Definite..... ibU
Engineering, Efficiency 446, Hot-
fecker "Kb
Engineering Foundation, The 110,
*179 795. A suggested activity.... 66V
Engineering hobby. Cultivating..... 581
Engineering, Research and equip-
ment; Kingsbury's bearing 339
Engineer's salary, Factors in....... bL6
Engineer's status discussed by A. I.
M. E ■ -. ,-, ilb
Engineers. See also "American,
"Ohio,". „ , . ,
Engineers, Am. Soc. Mechanical —
Boiler-accident report 499, Papers,
*69 «104, 656, San Francisco meet-
ing'plans 492, Spring meeting plans
for Buffalo, 729, Chicago sec. — Re-
frigeration night 4S9, Chicago sec.
discusses elec. locomotive 729,
Cleveland sec. — Carbon-brush trou-
bles »55S, Legislative work t>95
— Uniform boiler specifications 25,
Approved by council; portraits of
committee «268, 271, Adopted by
Ohio 526, Michigan situation 717,
Elsewhere 6S2, Difficulties 548,
Discussed by Boiler Mfrs. 896,
Safety valves 81, 241, 380
Engineers and firemen, Tribute to —
German warships 479
Engineers and supply houses....... »4S
Engineers, Educational aid to — Kan-
sas 784, Oregon »|0
Engineers. Handbook for. Pierce ... t^&b
Engineers, Relations of consulting
and operating • ■ ■ 47y
Engineers' exam. questions 401,
Carey • ioo
Engineers' examinations — Inconclu-
siveness "45
Engineers' license and boiler laws.
See also "Boiler."
Engineers' license laws, Unreason-
able 548
Engineers'-license legislation in U. S.
—Summary of laws. Potter 792
Engineers' license legislation, Mass.,
306, 410, 513, 760, 792, SIS. Statistics
294, Hearing 418, Does the law dis-
criminate? 89U
Engineers' licenses — Live steam vs.
live men 410, 412
Engineers' licenses, N. J. — Examin-
ing the examiner 156, Exceptions
in the law •••,•; §„;
Engineers' salesmanship. Pohlman. lii
Engineers' licenses, N. Y. Cy .95, 271
Engineers' study course. Se,
"Study."
„ . Page
Engineers' wages, various plants
fagett 1S 26 201
— ErtCreaSlnS '"ens. Knowlton S52,
Ennis, W." D." ' Saturated-air proper- *5
ties
Equalizing switch', Side for 'connect-
ing
102
.±555
Evaporation, Equivaient.' '.'.'. ±521
Evaporation, Factor of, with super-
heated steam tS95
Evaporation, Higher, per lb! 'of coal
Saving trom ±655
Evaporation, Relative economies'bf !±791
Ewing. Watt-hour meter accuracy. 244
Examination questions 401, Carey. 758
Examinations, Inconclusiveness of 645
Examining the examiner, N. J 156 j
Exh'at„tf0%VUtp?t Percentage for ±.8SS Franklin Oil & Gas 52
Exhaust. See also "Gas." "Steam" carhnrof^r
Heating." "Turbine, Steam," etc
Exhaust fitting, Large double. Hur
P OWEE
Page
llywheel risks. Effect of high steam
pressure on 54s, Strenuosity. Wil-
liams obo, Piston speeds. Jones.. 755
Fywheel speeds. Halliwell 7. 815
flywheels explode, 111. steel Plant.. 491
formulas, Simplified 294
Foster feed-water regulator. ...'.'.'.' .'•512
foundation bolts in concrete. An-
choring. Croft «s4i
foundations— Concrete-filled beds!!; »94
foundations — Grouting under heavy
Fo"5 Trf^f 31°- 482' *62°. 7S6
£>\ Transformer connections »46,
isl. Changing the service of direct-
current machines 29S, Direct-cur-
rent vs. 3-wire systems »505
iractional-hp. motors. Lester »5S9
her, T. Chittenden plant ..... ... •494
s cylinder-oil
carburetor *674
Franklin, W. S. Advanced Electric-
ity Tb24, Elementary Electricity. . .±660
Fuel. See also "Coal." etc.
Fuel, Burning low-grade «79S 817
g^SS^iS! -i^-^-de.'an'dwastVs: J"
n*'on !??«{, AjLberger "Ross"5.' .' tffi Fuel-laving' compounds.'.'. 201 li
Exhaust-pipe 'size,' Common.' '.'. ±417
Expansion, Coefficients of '.'. .J209
Expan___.
Expansion joints, Rubb<=i .
Expansion trap, Winn .?nq
Expense accounts, Concerning 9«
^Tank"' -^ee :;B?.!ier'" "Flywheel'," 6
"HeSter " ' "Turbine, Steam!"
EpPa°cSifitc0';1' SCe alSO "Panama-
Exposition, Made in "U. S 4.
Extra man. Value of
73
sewage-pumping station.
Fairview
Detroit. Wilson.'...
Fan. See also "Blower"
Fan draft explained Hirshfelrt «e--
hou.e a 'Zer' Portab'e. Westing! 9°
Sf dSral Bidg'. 'Chi.', Saving' in '. .' .' '. ] ] ! ] 'III
F^^^i#eer^.^ate?V.mI,•" "***W
Fetror^U!°matiC electri° Pump con-
Feed-w'at'er meter,' Grit in' ' Pearce"*^!
su"tWater reguIator. Eckel "hydro!
P~inat£at31!' rIgulatcr Foster autc
^K Bel^^10^ ' MeDonougb
Feed-water t
'466
512
•87
traps for.
See "Graphite
— ler; regulators,
90
34
er?Taarenrsw'0arthheater a"d W^"
^ni"^ boiIers, Return
Gilbert
Feeding graphite.' ' Se: ' "~" '
Feeding. Scientific boil
etc. Nick
Field coils. Reversed." Parham:::
Held connections, Neglected ±A
change. Eisemann... ' t0.!>i,
water A' Gas-engin'e ' 'cooling *"
FMil1°slder fcr ^^thing valV'e'stat '83
P&teCo^aCkbUrn-Smith twin- Beggs,
Gage. See also "Tank," "Draft," etc.
Gage, Absolute pressures from ±31
Gage-glass, Hill •70S
Gage-glass reflector, Safe Guard' Re!
ordway »833
Gage-glass stains, Removing.' !.""'."! '±835
Gage-glasses breaking, Water seal
,_ to prevent. Schneider .755
•-'a.fe-glasses on locomotive boiler's
McManamy g99
Gage-glasses, Using short', "palmer; 4i6
Gage hand vibrated. Aldrich 27
Hurst 206
Gage — Queer action in water 'column
Jorgensen »7S7
Gage readings, Conversion ' of' ' into '
absolute pressures ±311
Gage-tube action, Bourdon i'895
lja?e— Water column variation' for
difference of temperature... ±31
Gage, Water. Prince-Groff 'cb.'s
Pressurlokd " .. ,,r.
Gage, Water, Safety-First.' .' '.'.'.'.'.'.' '•472
Gages, Recording brine and tide. . . »9
Gaging— Telephone receiver con-
nected to calipers. Carr.. • 6"i
Garvens' elevator-rail greaser..."" •£•>
Gas, Coal, Residuals. Wagner ±560
Ro! combustion— Air needed J823
Gas, Exhaust, heated boiler. Moore. «S93
Gas explosions in boiler furnaces.
P-e, B!°,s.- °f Du Pont Powder Co.,
553, Quinn. Bellinger, Scrivenor
651, Cramer *719, Hawkins... 785
Gas, Flue. See also "Carbon
oxid
Gas. Flue, analyzer, etc
di-
Precision
Fink^nhrV^ !j.°okins out' for:; ;;;;;; m inst co/s;...
'^^n^-^-^.wiia.;;
Fire protection— Plant dl"itn II
metering, different pres!
"H£L*". tOT ^ner-furnace^^ii:*530
Firebrick for bbi'le
97, 305
Heisel,
*883. 890
mployer thinks of... '357
ler settings
Fireman ™T"n c""i'»^r thinks
If NoVrn P^UScaI °PPortunity" for
lison Supreme Court. Al-
FirBm2r. Gc::l triatmant if Jjj§
s^r^ RUbbeF Co "s hydraulic *83
First-aid jar ■.•.■„•_■ *671
^ttiTlffE?c-,neering"Econo'mics.' 185, + |2o
Jickfr arpe dOUb,e exhaust! Hunl60
tandard flanged.'
;."fiitP- S' standard. »782; S61
Fo^.^see1^-^,.^ Pumping. ."±356
•lywheel key. slipping,
guard. Robinson.
Flywheel "
helil by
HttSSStuE'8 w:cdin Rrk;1^
379
'7S9
Gas-fuel
sures . .
Gas making— Conditions 'reversed.'" 200
tras. Natural, Gasoline engine run on
rTs<oneSW0hIite.GaWthrOP 654' Mor" .„
Gas. Natural, more than oil 7
Oas-producer plant. Test of 200-'h'p '
by Lehigh Univ. Larkin . . c
If^8"*.^.0101" Power plant. Hull. »226
r,™: vapor," "steam." Sandstroni "97
Gasche. Convex-head stresses «59,
•4o0. Theoretical efficiency of heat
engines » — ,
Gasket. See also "Packing'"
pk,et' 1^ Emergency— Lead rope.
Reynolds «725, Noble xq-.
Gasket, Manhole, Calculating how' to
cut. Wires
Gaskets for plugs' o
valves. Solomon 61, Losh "41
Gasoline engine See "Eneine. In! "
ternal -combust ion."
Gasoline production, New methods,
Gear ratio. Changed. Horton . . ."'j f2?6
Gear. Reduct.on. Turbo-Gear Co.'s..«SS7
Gearing. Ingham tits
,:r 1,1 Coaiensap tiz. a tm, n^
General Electric series trip for high!
voltage oil switches «304. Steam-
meter_hp. constants. Collins. '773
January 1 to June 30, 1915
Page
Gibson. Heat distribution in gas-
engine cylinder «824
Giele. Return traps for feeding boil-
ers .467
Gill, A. H. Testing oils "' 522
Gin pole, Raising. Keys.... »29
Gintz. D. C. armature winding »335
Glands, Labyrinth — Martin's formula,
• 42g
Glass, Drilling holes in ±857
uood treatment, good service. Wal-
dron ^gg
Goodrich. Forced-draft cooling Vow-
Goulds centrifugal' pump: ::.'::"" '»257
Government as power buyer Con-
nor " ggg
government fuel -test 'reports:.'.'!.'.': 645
furnishes cheap elec-
••--, 228, »422
printing-office power
«576
safety valve
Fuel, Synthetic. '". . .77 ** 3A5
Furnace. See also "Boiler" and
cross-references from it.
Furnace arch. Staying. Hawkins. . .«600
™nac,e i,1,?1"^' etc.— Pottery clay.
Wood 62 Concrete. Sandstrom
Blanchard 131, Hawkins 169 Ce-
ment. Strong 274
Furnace system. Morrow. ..." »425
Furnaces, Boiler, Firebrick for 'Wil-
liams 297, Heisel «883, Ed...:. 305
Furnaces Metallurgical, etc., with
waste-heat boilers »196 1
Fuse and lamp tester. Sheridan. '
134
ernm
trieity . . .
Government
plant. Tuck" .
Governor, Ammonia
which raises. Geare ."...'. ""•307
Governor, Blocking up. Richards
*Aii, Terman 432
Governor compensators, Corii's's'.
Stewart 415, Bascom »894
Governor, Inertia, trouble. Hawkins •§*>
governor pins. Case-hardening ±587
Governor pulley. Changing. . . ±102
Governor-stop control and belt tight-
ener 00
Governors, Centrifugal 'and inertia.' :±277
Governors, Hydraulic, Salmon River *325
Governors, Stability and isochronism
of
S90
state, water-
.J857
Governors', Western
power conference
Gradenwitz. New Schlotter blower.' >261
Graphic Methods. Brinton ±3S8
Graphite and oil cylinder lubricator,
Phenix »780
Graphite in boilers. Weaver ' 13V
Poe,nn£tt' Blanchard 341, Armstrong;
4S4, Feeding. Wilev »616
Graphite, Silica, paint for boiler
drums one
Grate, Poillon furnace":: •499
Grease retarder, Keystone. »H7
Greaser, Elevator-rail, Garvens'.::: »82
Q,TSeTl;- s' M" c°i water-tank con-
trolling device »g8o
Greene A. M Jr. Heat Engineering f660
Gnpwell pulley covering... 334
Ground localizer, Westinghouse' port-
able .350
Ground, Puzzling. Thurston. ..." "•34-'
*°-u£,',ng under heavy machinery.
McClmton 310. Wilson. Johnson 4S2
Poche «620, Pearce, Benefiel 786
Gun — Horsepower of cannon 511
H
Haas. Diesel engine, Palo Alto '502
Hacksaw blade, Nonbreakable, At-
kins .4fll
Hall's quarter-turn coupling '117, '310, 683
Handbook for Engineers. Pierce. .. ±356
Hands, Sand for cleaning. Benefiiel 854
Increasing boiler capac-
Trieks of 'the'tr'ade" 60
, Diesel engine. South-
877
•55
649
Generator. See "Electricit>
Giant Portland Cement Co
pump for ashes. Havard
s dredge
Harrington
ity .
Harris,
Harris,
wark
Harrisburg, 111., railway and power-
plant. Wilson *698
Havana, Reinforced-concrete chim-
neys .166
Havard. Dredge pump handles ashes »580
Hawkins. Retubing boilers *330, 586,
Staying furnace arch *600
Haynes. Crankpin troubles ... l">o
Hays. Waste hot water heats feed-
water
Headers, Putting new, in water-tube
boilers. Gray
Heads, Convex, Stresses. Gasche •bV
Mass. formulas 202, Convex and
concave drum heads. Hogan *450
Finding radius $587
Heat conversion during expansion . .J417
Heat distribution in gas-engine cyl-
inder. Gibson, Walker «824
Heat Engineering. Greene ±660
Heat engines, Efficiency of 103, 136
Cycles .173, .2i0
Heat engines, Theoretical efficiency
of. Heck •534, Gasche '753
Heat, Latent, of fusion and evapora-
tion toll
Heat, Specific, and heat of ice fusion
Dickinson, Osborne 555
Heat-value calculation 264
Heater — Bayer water purifier «400
Heater, Closed, capacity J417
Heater, etc. — Farnsworth tilting trap »90
Heater explosions; no relief valve
Dempsey .692
Heater. Home-made feed-water.
Robinson 343
Heater, Oil from, got into boiler.
Gibson •$<>
Heater, Open feed-water. Jorgensen *441
Heater, Open, Highest feed-water
temperature with ±277
Heater-tube leak, Stopping. Miles.: 754
January 1 to June 30, 1915
POWER
Page
Heater tubes, Use of Iron t655
Heaters, Feed-water, Jackets of
chemical tanks as — Waste hot
water heats feed-water. Hays, . . . *55
Heaters, Feed-water — Open or closed?
Beekley 204
Heaters — Tank vents. Reynolds.... 484
Heating feed water, Economy of.
Anderson 644
Heating feed water, Saving by 1487
Heating water, Pipe surface for.... $209
HEATING AND VENTILATION
— American Cigar Co.'s plant, h. &
v. system. Durand *460, 541
—Boiler explosion, New Orleans.,.. 420
—Central-station heating mains,
Testing, Indianapolis 896
— Future developments in heating
and ventilation; experimental work
at the University College, England.
Barker 897
—Grease, Cleaning coils of 1349
— Heating and Ventilating Buildings.
Carpenter f624
— H. & V. Engineers' meeting — Com-
parison of Toledo and Detroit
plants; comm. statement on com-
pulsory ventilation; papers on
ozone, physiological and psycho-
logical effects of humidity and
temperature, etc. *175, "Journal" .. t695
— H ot-blast heater condensation.
White »128
— Hot-water tank explosion *451
— Hughes Elec. plant, Bismarck, N.
D. — Exhaust steam for district
heating '732
— 111. University h. & v. course 387
— Karpen plant engine discussion.. 27
— Lumber Exchange Bldg. plant .... *768
— Natl. Dist. Heating Asso. conven-
tion S61
— Overflow, Location of. Reynolds.. 169
— Pipe sizes, Hot-water $135
■ — P owe r-plant design — Comparing
steam requirements with available
exhaust «66
— Radiator valve, Adsco graduated. .»115
— Radiator would not work — Pencil
under trap thermostat. Binns. . . .»414
— Refrigeration vs. heating. Luhr. . 490
■ — Returns, Receiver of, should be
vented 1655
■ — Saturated-air properties. Ennis.. 402
— Scranton exhaust-steam heating
system *875
— Smoke-stack connection of two
Chicago buildings «643
— Standby plant supplying steam to
central heating system — N. W.
Elec. Co 726
— Steam coil in tank. Noble «756
— Steam, heating value at certain
pressures |31
— Vacuum heating systems. Durand 605
— Vacuum heating without thermo-
stats. Crosthwait, Durand 346
— Ventilation of assembly rooms,
Air-supply for 1S23
Heck. Theoretical efficiency of heat
engines *534, Gasche *753
Heisel. Firebrick for boiler settings,
*883 S90
Herschel. Vacuum for turbines. .. .'»744
Hill gage-glass *708
Hill-Tripp centrifugal pump *634
Hilliard clutch shifter «706
Hirshfeld. Traveling screens, Del-
ray *333, Future methods of util-
izing coal 4SS, Boiler draft »675
Hobby, Cultivating an engineering. . 581
Hoist, Canton portable floor crane
and *574
Hoist, Flywheel balancing mine *20
Hoist, Homestake mine's compound
condensing Nordberg *386
Hoisting engineer, Hunter. Rogers *160
Homestake mine's Nordberg hoist.. *386
Hood over dash pot. Strong *892
Hoppes V-notch meter impvts *S07
Horsepower and torque defined 433
Horsepower constant 369
Horsepower constants, Steam-flow
meter. Collins »773
Horsepower, Fixing the. Durand.. 343
Horsepower, Indicated, brake and
friction 1135
Horsepower of stream. Calculating.. 726
"Horsepower," Origin of J417
Horton, J. A. Wrong voltage on motor 267
Horton, R. E. Calculation of coal.. 622
Hose-clamping tool, Wieder *478
Hot-bulb oil engine. Lundgren .... *79
Hot water. Pumping. Rogers *169
Hot-water tank explosion *451
Hotel, La Salle, plant saving 63, 99
Housing, Repairing gas-engine. Grif-
fin »788
Howard, James E. Riveted joints.. 216
Howard, John. Temperature effect
on centrifugal-pump capacity ... ,*406
Hubbard. Selecting pump *198, 345,
519, Isolated-plant boilers 232, 447
Hughes Electric plant. Larsen *732
Hull. Gas-tractor power plant *226
Page
Hunter, Hoisting engineer. Rogers »160
Hurley. Lining up small turbine
sets '714
Hyde. Reciprocatlng-pump slippage. *468
Hydrant, Water discharge from $857
Hydraulic Press Mfg. Co.'s valve,
•138, Single-acting triplex pump..*462
Hydraulic pressure pump operating
without accumulator. Palmer.... 852
Hydraulic pumps, Power and capac-
ity of. Lachmann 89
Hydraulic rams. Hubbard *199
Hydraulic service, Two-pressure,
Firestone Rubber Co. Williams. .*671
Hydro-electric. See "Water power."
Hydrometer, Principles of — Quizz... 153
Hydrostat feed-water regulator «466
Ice. See also "Refrigeration."
Ice, Anchor $102
Ice-fusion heat and specific heat.
Dickinson, Osborne 565
Ice-selling example — Different rates.
Seed et al *383, 550, 684
Ideal multi-cone clutch, Akron *533
Ignition systems, Spark-plug. Israel. *25S
111. Steel Co.'s flywheels explode 491
111. Univ. notes. 71, U4S, 387, 420, t660, 751
Imperial portable compressor '86
Indexing technical literature 783, 795
India, Boiler steel required for 623
Indiana Engineering Society. 243, 244, 419
— Ammonia diagrams, Comment on.
Ophuls 204
— Ammonia diagrams, Incorrect.
Larkin *415
— Brake power by indicator $693
— Cock, Effect of throttled — Am-
monia-compressor diagrams. East-
wood *688
— Connecting pipes, Influence of.
Morley '622
— Diagram — Correction for twisted
valve stem. Kjerulff *99
— Diagrams, Computation of $487
— Diagrams, Making two or more
simultaneously. Loonier '722
— Diagrams, Notes on — MeNamm's
and others. Nottingham *309, Bonn 61S
— Piston, Indicator showed leaking.
Smith *874
— Reducing motion. Nugent's '538
— Vacuum line. Drawing true {521
Individual effort. Merit of 480
Industrial betterment, For 752
Industrial education. See "Educa-
tion."
"Ingeniero y Contratista" $866
Ingersoll-Rand portable compressor,
*S6, High-efficiency compressor. .. *S88
Ingham. Gearing $458
Inspection. Boiler. See "Boiler."
Instruments, Efficiency, Making most
of 582
Insulation resistance, Maintaining
high; applying varnish. McLellan '365
Interborough turbines, 74th St. *527,
•528, 547, Power per boiler hp 130
Interferometer, Compound 795
Internal-combustion. See "Engine."
International Engineering Congress.
See "Panama-Pac."
Tnternatl. Ry. Fuel Asso 793
Irenew valve. Powell »444
Iron and steel weights $385
Iron to aid combustion S56
Irrigation and Pumping. Fleming. .t356
Irrigation — Boise power house "594
Irrigation project, Minidoka. .. .22S, *422
Isherwood. Rear-Adm. Death of....*903
Isolated-plant experience. Binns. . . 6S6
Isolated plant, Small, pays big divi-
dends. Wilson *51
Isolated plant vs. central station:
See also "Power plants," "Rate."
plants by name, etc.
— Am. Mfg. Co. buys power 3S0
— Govt, as power buyer 636
— Netherlands commission report.... r, S2
— Play by Brooklyn engineers 6S1
— Rates. Reasons for different; ice-
selling example *383, 550, 6S4
— Tear's review 25
Isolated plants. Boilers for. Hub-
Kin] 232. Hyde 447
Isometric drawings. Hampson *7S5
Israel, Snark-plug ignition *258
Ivens. Air-lift efficiency *S43, Prim-
ing centrifugal pump *8S0
Jack, Simplex emergency, Templeton,
Kenly * Co.'s *846
Jacket. See "Water," "Cooling."
Jackson. Variation in coal constitu-
ents for similar B.t.u. values 441
Jacksonville municipal plant *35
Java, Waterwheel repair in *838
Jenckes plant, Synchronous motor in 478
Jenkins composition valve disk 40
Jeter. Lack of synchronism in
check-valve action *4S, 242
Page
Johns Hopkins buildings dedicated.. 761
Johnson. Ammonia as heat vehicle. . 727
Joints, Diagonal, Strength. Terman,
•296, Grimes, Irvington *485
Jones, J. F. Priming centrifugal
pumps «294, 481, *550, 615, 788, *S80
Jorgensen. Open heater *iii
Judgment, Engineer needs 237
Just for fun 96, 16S, 264, 295, 350, 407,
440, 469, •501, 539, 573, '709, 747, 772, 835
K
Kalamazoo municipal plant. Wilson. *218
Kansas aids engineers educationally . 784
"Kantsplit" valve handle '665
Karpen plant engine. Ed. 26, Mor-
rison, Wilson 27
Kehoe. Refrigerating-plant costs.. 710
"Kelvin" — Suggested unit. Wallis.. 172
"Kent," Engine-room performance of 574
Kerosene. See "Engine, Internal-
combustion."
Key, Flywheel, slipping, held by
guard. Robinson *789
Keys, Liners with. Herman '552
Keystone grease retarder *117
Kidston. Seattle lighting plant »182
Kilowatt-hour substitute. Wallis... 172
Kimball. Humidity and temperature 177
Kincaid stoker, New *42
Kingsbury's bearing, Invention of... 339
Kingsford double-flow pump '85
Kirchgasser. Automatic electric
control of pumps *811
Klemm. Mexican turbine plant *192
Knock, Dont, but push *593
Knowlton. Stoker- and hand-fired
boiler tests *300
Korting-Diesel engine, Palo Alto...*502
Kreisinger. Hand Firing Soft Coal. .f317
La Salle Hotel, Former engineer of,
defends his administration. Law-
rence 63, Bird, Peterken 99
Lachmann. Hydraulic pumps 89
Laidlaw-Dunn-Gordon air-compres-
sor valve test *537
Lamp and fuse tester. Sheridan.... *61
Lamp, Tungsten, dimmers. Waller.. *491
Lamps, Flickering. Horton '205
Lamps, Wiring for; choice, distribu-
tion, data, etc. Cook »601, *640,
•666, 891
Lap, Inside, Effect of 1655
Larkin. Gas-producer plant test.... 6
Larries, Coal-weighing, Cleveland.. *17
Larsen. Hughes Electric plant *732
Launch engine. Small. Roger «191
Lauson heavy-duty kerosene engine •lie
Law. See also "Engineers' license,"
"Boiler," "Water power."
Law, Locomotive boiler inspection.
Results of. McManamy 8S9, 898
Law — Recent court decisions. Street,
109, 144, 2S3, 355, 457, 591, 658, 694,
720, 795, Engineering points in them 237
Laws, Child-labor. Hawkins 851
Laws, Progress in — Accepting the in-
evitable 751
Lead pipes. Rule for thickness and
weight of 350
Lead rope as gasket. Reynolds '725,
Noble 893
Leak, Stopping heater-tube. Miles.. 754
Leak, The (poetry). Strohm *149
Leaks small and big — La Salle Hotel
plant, saving 63, 99
Leather, Cement for 532
Legislation. See "Law" and cross-
references from it.
Lehigh Univ. test of gas-producer
plant Larkin 6
Leonard, H. Ward, Death of 356
Lester. Fractional-hp. motors *589
Libra, Spanish, Weight of $895
License. See "Engineers'."
Life story — Purposeful anecdote. .. .*829
Lighting. See also "Electricity,"
"Power plants."
Lighting. Accidents from poor 420
Lighting and power. Interior wiring
for. Cook »601, *640, *666, 702, 736, 891
Lighting plant, Municipal, Kalama-
zoo *218
Lighting plant, Opelousas' municipal *41
Lighting plant, Seattle municipal,
71, *1§2
Lightning arrester. Raitt, Goodwin. *483
Lightning, Effect of, on rotary con-
verter. Swift *97
Lights, Flickering. Horton *205
Lignite burning. Hughes plant *732
Lignite in deep furnace. Morrison.. 485
Linderhurst. Boiler- joint stresses. . *611
Liners with keys. Herman *552
Lining up small turbine sets. Hur-
ley *714
Linquist. Elec. traction elevator... 656
Liquid "weigher improved. Loef *687
Little things. It is the 645
Live steam vs. live men 410, Conn.
Engineer 412
Loafing (?) engineer. The lfiS
Lock, Nut. Proctor *691
10
POWEK
January 1 to June 30, 1915
Page
Locomobiles, What causes the high
efficiency of? Pearce 633
Locomotive boiler inspection law,
Results of. McManamy SS9, 898
Locomotive crane, Operating. Honey *411
Locomotive, Electric, discussed 729
Locomotives, Electric, Norfolk &
Western *830
Locomotives, Fuel-oil for. Bean...*900
Locomotives, Powdered coal for 793
Locomotives, Stokers for — Buell's re-
port S17, 827
London. Small condensing turbines *426
Longer way is safer *285
Losses in Factory Power Plants,
Preventing. Myers t592
Losses, Power-plant, Graphic repre-
sentations of. Dreyfus '63S
Low bidding, Evils of 4S0
Low, F. R. Steam-turbine diagrams
•596, Robinson '650
Low-pressure complaint, Stopping.
Sandstrom 310
Lubeck refrigeration-plant perform-
ance. Stetefeld 212
Lubricant. See also "Oil."
Lubricating bearings, Sargent's
Wharf *12
Lubricating compressor piston rod.
Thurston «647
Lubrication — Keystone grease re-
tarder *117
Lubrication; quality and mixing of
lubricants 410, Fiomeyer 721
Lubrication, Turbine — Step- bearing
accumulator. Bankhead *265
Lubricator — Elevator-rail greaser,
Garvens' *S2
Lubricator, Phenix oil and graphite
cylinder »780
Lubricator sight glass in overflow
pipe. Hurst *690
Lucas. Testing and repairing pyro-
meters *712
Lugs. Home-made. Gerber *75S
Luitwieler double-acting triplex
pump *750
Lumber Exchange Bldg. plant. Wil-
son *764
Lundgren, E. Hot-bulb oil engine.. *79
Lunkenheimer balanced throttle
valve *814
M
Macdonald. Boiler-plate tests *779
McDonough feed-water regulator... »S7
McDougal. Large alternator test.. S6
McFadden. Plate valves for high-
speed air compressors *366, 517
McKee. Power requirements of am-
monia compressors *15S
McLellan. Maintaining high insula-
tion resistance *365
McManamy. Results of locomotive
inspection law 889, S9S
MacNicoll. Safety valves 509
Machine Shop Management. Van
Deventer |S65
Machinerv, New vs. second-hand.
Blanchard 134
"Made in U. S. A." Expo 73
Magnets, Electro, for a.c. circuits.
Meade *14, Correction, Jacobi.... 203
Making the dollars produce 614
Manager, Troubles of. Weller *421,
Salesmen's reply. Dunkley »731
Manhole gasket, Calculating how to
cut. Wires 134
Marine — Elec. ship propulsion. Emmet 657
Marine oil engine, Thermodynamics
of. Wentworth *145
Marine power plant. Small. Roger.. *191
Marine review of year 23
Martindale. Carbon-brush troubles *55S
Mass. boiler rules *48, 202, 242
Mass. electric rates discussed 282,
Discrimination. Jackson *549
Mass. engineers' license statistics 294,
Legislation 306, 410, 418, 513, 760,
792, 818, Does the law discriminate? 890
Materials of Machines. Smith |796
Mathematics, Vocational. Dooley. . .T/796
Meade. Electromagnets for alt.-
current circuits '14, Correction 203,
Designing small transformers *262,
Automatic electric elevator dis-
patcher *540, Auto-transformers. .*S04
Mechanical Engineers. See "Engi-
neers," "Ohio."
Mechanical Rubber Co. — Good treat-
ment, good service. Waldron 483
Mechanical World Pocketbook 1624
Menlo, la., boiler explosion. Kirlin..*3S2
Mercury as working fluid 23
Mesta gas blowing engine. Large.. *395
Metal shrinkage during solidification 316
Meter accuracy, Watt-hour. Ewing. . 244
Meter and pump trouble. Powers. . . 348
Meter, Biddle "Cournon" steam *545
Meter, Condensation, Am. Dist. Steam
Co.'s "Simplex" »569
Meter, Feed-water, Grit in. Pearce.. 654
Meter, Hoppes V-notch, impvts *S07
Meter, Hp. constants for G. E. type
F steam-flow. Collins *773
Page
Meters, Liquid flow, Testing. Giele.. *69
Mexican turbine installation. Klemm *192
Michigan is in line 717
Milestones *625
Mine boiler plant, Bessemer Coal &
Coke Co.'s *79S, 817
Mine hoist, Flywheel balancing *20
Mine hoist, Homestake's Nordberg. .*3S6
Mine, Mexican, turbine plant *192
Mine-plant notes 120, 124
Mine plants. Rogers '160
"Mine, Quarry and Derrick'' t365
Minidoka irrigation project. Walker
228, Connor *422
Misconceptions, Some common 401
Mistaken notion. Baker 894
Monkey-wrench, Bayer quick-acting *264
Monnett. Reconstructing water-tube
boiler settings *54, *91, Correction
as to underfeed stokers *132,
Waste-heat boilers; metallurgical
and special furnaces *196, *432
Morley. Indicator connecting pipes *622
Morris. Oil engine for off-peak load »3ol
Morrison. Centrifugal crude-oil
pump *454
Morrow furnace system »425
Motor. See "Electricity," "Engine."
Mouse causes plant shutdown 504
Moving Western Newspaper Union
plant *2
Moyer. Steam Turbines t591
Mud-drum, Safety of cracked +4S7
Municipal. See "Power plants,"
"Rate," etc.
Myers. Preventing Losses in Fac-
tory Power Plants t592
N
Nagger, Don't be a *389
National Dist. Heating Asso 861
National Elec. Lt. Asso. 582. 827,
At the Exposition 'SoS
Natural gas. See "Gas."
Naval Architects and M. E "145
Naylor, William. Death of *S64
Neff. Refrigerating-plant losses.... 77S
Netherlands commission report 582
New business. Getting 57
New Jersey — Examining the exam-
iner 156, Exceptions in license law S90
New Orleans municipal plant 526
New Roslyn Hotel plant *748
New Tear — Cartoon *1, Review 21,
157, Letter. Laas 75, 238, 239, 4S1
New York Cent, wins medal 282
New York Cy. — Subway accident 7 4,
Engineers' license 95, 271, Refrig-
erant regulations. Solomon 170,
Silence on Hall of Records tests
306, Rejoinder by Williams 414,
Rate publicity ordered 355, Inter-
borough turbines, etc. 130, *
New York Edison rates 340, 386
New York. N. H. & H. R.R. — Cos Cob
plant. Rogers *35S
Nick. Scientific boiler feeding *34
Nickel, F. F. Direct-Acting Steam
Pumps t695
Nickel steel. Properties of $823
Night engineer off duty. Losh 205
Nipples 16
Noise question, The 646
Noises. Electric-motor. Davies *572
Nordberg engines, Two new *11S,
Mine hoist *3S6
Norfolk & Western electrification .. .*830
Northwestern Elec. Co.'s plant 726
Norton Co.'s boiler plant *300
Norwegian waterfall concessions.... 7S1
Nozzles, Steam. Quizz *56
Nugent oiling system *90, Filter «436,
Vertical-crankpin oiler *735, Indi-
cator reducing motion *53S
Nut lock. Proctor '691
O
Ocean volume to land area 433
Ohio adopts A. S. M. E. code 526
Ohio Soc. of Engineers *108, *883
Oil. See also "Lubricating," "Petro-
leum "
Oil- and coal-burning plants. Chim-
neys for. Rosencrants 637
Oil and coal efficiencies $385
Oil-bill decreases. Durand 276
Oil burner, Champion *7
Oil-burner regulation $27'.
Oil burner, Witt rotary crude 'S15
(Ml burning discussed by N. E. L. A. .'859
Oil burning, Los Angeles *74S
Oil cooler, Sehiitte & Koerting *564
Oil, Crude, Centrifugal pump for.
Morrison *454
Oil-cushion cylinder supply. Dear-
born *758
Oil, Cylinder, "carburetor," Franklin .'674
Oil engine. See "Engine, Internal-
combustion."
Oil, Evaporation per lb $102
Oil feed. Condensing coil on. Reed..*647
Oil filter, Nugent improved '436
Oil filter. Richardson-Phenix Co.'s
"Peterson" power-plant '606
Page
Oil filters, Sargent's Wharf *10, «13
Oil flash and burning point $759
Oil from heater got into boiler. Gib-
son *62
Oil from turbine bearings, Tempera-
ture of $31
Oil Fuel. Butler U48
Oil Fuel, for locomotives; furnace
arrangements, etc. Bean *900
Oil — Gasoline production, New meth-
ods 513, t796
Oil, Lubricating — Fink frauds 694
Oil separator failed to "work, Rey-
nolds'. Robertson, McLaren 452
Oil-separator trouble. Goodwin *207,
Meinzer, Durand, Nelson '344, Metz 3S4
Oil skimmer. Receiver. Waldron.... '30
Oil switches, High-voltage, General
Electric series trip for *304, Crane 484
Oil, Test for animal and vegetable
contents in 318
Oiler, Chain, stopped. Pagett 344
Oiler, Nugent central, for vertical
crankpin *735
Oiling system, Changes turbine.
Johnson *583
Oiling system, Nugent pressure re-
•90
Oils, Testing lubricating. Gill 522
Old standby (poetry.) Strohm *561
Ontario water power 794
Opelousas' municipal lighting plant.
Jones *41
Open circuit. Testing for. Annett
195, Plimpton 452
Operating records, Cleveland. Wil-
liams *292, 306
Opportunity. Create the. Lamb *217
Oregon Agricultural College 85C
Original ideas for fun 84, 96, 16S, -264,
295, 350, 407, 440, 469, *501, 539, .".73,
•709, 747, 772, S35
Orsat. See also "Carbon dioxide,"
"Gas," etc.
Orsat apparatus, Defender modified. . *609
Ottawa electric rate 727
Overflow change, Pump. Dixon *171
Overflow, Location of. Reynolds... 169
Overflow pipe, Sight glass in. Hurst. *690
Oxyacetylene. See "Welding," "Cut-
ting."
Oxygen, Discovery of 70S
Ozone, Effect of. Feldman 177
Packing blowoff cocks with asbestos.
Burns 65
Packing, Cylinder-head. Kolar 61
Packing, Metallic, for valve stems.
Farnsworth *648
Packing, Piston-rod, More spring
tension on. Sheehan *683
Packing. Short cut in. Williams.... 239
Page. Carburetion-trouble chart... tS65
Pagett. Engineers' wages.... 18, 26, 201
Paint for engineering purposes.
Percy 234, Heckel 4S4
Painting boiler drums 876
Palo Alto Diesel engine. Haas *502
PANAMA-PACIFIC EXPOSITION
— A. I. M. E. meeting 492
— Buildings — Photos, and description
— Palace of machinery; compari-
sons with Centennial engine, etc. *250
— Comparisons of modern turbines
with Centennial Corliss engine,
etc. *250, '302, Forty years' ad-
vance in internal-combustion en-
gines *376
— General Electric exhibit 179
— International Engineering Con-
gress ISO, 24S, 317, 591, 624, 796
— Natl. Elec. Light Asso *858
— Opening 272. 317
— River-measurement model, Geol.
Surv 247
— Stationary Engineers' day 623
— U. S. Geol. Survey exhibits 387
Paper-mill power plants. Holmes... 758
Parr. Coal Analysis fl4S
Pasadena electric rates S01
Peak-load problem. Bradley '867
Pearce. Efficiency of locomobiles... 633
Penn. R.R. safety 58
Percy. Paint for engineering 234.
484, When gas engine will not start 299
Perkins factory rod break *375
Perpetual-motion-type machine 407
Peterson oil filter *606
Petroleum, Crude, production. Calif.. 508
Petroleum developments. various
countries 245
Petter oil-engine test. Salfeld 405
Phenix oil and graphite cylinder
lubricator «780
Phila. municipal lighting plant 200
Philo. Steam costs 368
Pierce. Handbook for Engineers. . .f356
PIPING
See also "Blowoff." "Valv,
— -Bedding underground pipes in sand
or gravel $209
— Bender. Pipe. Chandler »60
January 1 to June 30, 1915
P 0 W E R
11
Page
PIPING — Continued
— Calking leaks. Hawkins 6S9
— Cleveland municipal plant, Piping
and supports in — Expansion bendB;
sliding" lloor plates; rollers; an-
chors, etc. Williams *463
■ — Copper and brass pipes, British
rules for properties of 512
■ — Corrosion, iron and steel pipe,
Sandstrom 416, Dunklev, Noble 584,
Natl. Tube Wks.' conclusions 848
— Covering, Cheap steam-pipe 508
— Die stock, Borden "Beaver" cross-
bar *644
— Discharge pipe, Smaller, worked
better 1759
— Discharge pipe with drop leg,
Pressure in 1209
— Exhaust fitting, Large double. .. .'543
— Exhaust pipe size, Common 1417
— Expansion joint, Alberger "Ross".*375
— Expansion joints, Rubber *532
— Flanged fittings, U. S «7S2, 861
— Heating mains, Testing central-
station 896
■ — Heating-pipe sizes, Hot-water. .. .1135
— Heating water. Pipe surface for... 1209
— Lead pipes, Rules for thickness
and weight of 350
— Lumber Exch. Bldg.'s small steam
piping and large receiver sepa-
rators »767
— Nipples 16
— Proportions, Diagram for. Hamp-
ton *586
— Pulsations in steam pipes. John-
son 620
— Safe piping 581
— Size, Use most economical 612
— Steam-engine pipe sizes — Chart.
Salmon «88 '
— Steam-line expansion formula 435
—Steam-line specifications. Craft... 612
— -Steam lines, Clean new. Strong,
785, 889
■ — Steam-main and stop-valve ar-
rangement 1 209
— Steam pipe, Heat loss from 1521
— Steam-pipe installation, United
Piece Dye Works — Connecting two
old boiler plants; equalizing.: pipe-
line support. Collins *2S8, Er-
ratum 401
— Steam-pipe radiation loss 287
■ — Steam- pipe size 1S57
■ — Steam-pipe systems, Loop, ring and
duplicate 573
— Steam pipes. Elasticity and endur-
ance of; Bautlin's experiments on
bends, etc. Stromeyer *278
— Steam piping — Various points 443
— Steam-pressure drop analogy 770
— Steam velocity in pipes 838
- — Steam velocities, Saving fuel by
higher 466
—Stopper, Pneumatic — Preventing
backftow when cleaning drain pipe.
Reardon »724, Noble 822
— Threads, Standard — Correction.... *94
— Tubes, Wrought-iron and steel;
threads, etc. Stewart 523
- — Aracuum pi*>e cracked and repaired.
Sword »648
— Water-hammer in steam pipes. .. .1857
— Weight rules. Cast-iron pipe 425
— Welding, Oxyacetylene. Roueche.
•808, 817
Piston. Difficulty in rotating, to un-
screw rod. Haines 651
Piston displacement. Meaning of.... 1791
Piston failure, Unusual — Wall worn
through. Dickson «6S9, Werner,
Perkins, Oates 854
Piston-fit allowances. Weaver *245
Piston. Indicator showed leaking.
Smith «874
Piston ring, Machining; dimension
table. Strom »353
Piston rod breaks, Stop acts when,
Perkins factory «375
Piston Rod, Lubricating ammonia-
compressor. Thurston *674
Piston-rod packing. More spring ten-
sion on. Sheehan »683
Piston speed. Duplex-pump 1857
Piston speed. Steam pressures and.
Williams 5S5, Jones 755
Piston trouble. Oil-engine. Griffin.. 650
Pistons, Stepped, for starting and
scavenging. Southwork-H a r r i s
Diesel engine *877
Pittsford Power Co.'s plant »494
Placing the blame 445
Planetary motion. The 716
Plant. See also "Power plants" and
cross-references from it.
Plant capacity, Increased. Babcock
685, Erratum 879
Plant operation. Keeping track of,
Cleveland. Williams *292, 306
Plant, Taking charge of larger 717
Plug. Pointed — Mistaken notion 894
Plumber and us, The 818
Plunger, Pump, repaired. Wallace. .'691
Plungers, Renewing pump — Making
of pipe. Piebig »853
l'age
Pneumatic pipe stopper. Reardon,
•724, Noble S22
Poetry '149, »249, '421, »561, '731,
Pohlfi. See "Air lift."
Poillon furnace grate *499
Pointing up brick, "Gun" lor '685
Polarity testing, etc.. Transformer,
•46, »3S1
Portable engine, Long chances with.
Addy 814
Potter. Dimensions, weights an. I
costs of steam turbines 750, Lid
legislation in U. S. 792, Notes on
fans 816
Powdered coal. Robinson 793
Powell valves *1 27, »444
Power cost. See "Cost," "Central
station," "Power plants," "Rate,"
etc.
Power, Govt, as buyer of. Connor... 636
Power, Horse, unit. Durand 343
POWER PLANTS
(Chiefly general descriptions.) See
also "Engine," "£?oiler," "Turbine,"
"Electricity," "Water power,"
"Rates," "Central station," "Iso-
lated plant," etc.
— American Engineering Co *38
— Analyzing plant's condition. Laas,
75, Ed. 238, Hawkins 239, Robin-
son 4S1
— -Apparatus, Interesting «20
— Appearance, element in value.
Dryfus 138
— Baltimore sewage pumping *76
— Bessemer Coal & Coke Co.'s boiler
plant. Rogers »798, 817
— Boise, Ida., Federal power house.. *594
— Brewery boiler plant, Stifel Union.
•662, S20
— Charting the plant 410
— Chicago Federal plant, Saving in.. 610
— Cleveland municipal electric *17,
•104, 109, »292, 306, »373, «463, «631
— Columbus municipal plant decision 354
— Cos Cob plant extension, N. Y.,
N. H. & H. R.R. Rogers »358
— Isolated plant, Small, pays big
dividends. Wilson »51
— Costs in small industrial power
plant. Thayer 465
Costs in tenant building 406
— Design problems •32, »66
—Detroit municipal pumping sta-
tions *150
--"Elbow room" in design 547
— Fairview sewage-pumping station,
Detroit. Wilson «286
— Gas-tractor plant. Hull *226
— Govt, printing office. Tuck »576
— Harrisburg. 111., railway and power
plant. Wilson *69S
— Hughes Elec. Co. Larsen »732
— Increased the capacity. Babcock,
685, Erratum 879
— Johns Hopkins plant 761
— Kalamazoo municipal plant. Wil-
son *218
— La Salle Hotel, Chicago 63, 99
— Layouts — The fine points 614
— Losses, Graphic representations of.
Dreyfus *638
— Losses in Factory Power Plants,
Preventing. Myers 1592
— Lumber Exchange Bldg., Chicago. *7fi4
— Marine power plant, Small '191
— Mine plant, Berwind-White *160
— New Orleans municipal plant 526
— Norfolk & Western electrification . «S30
— Northwestern Elec. Co.'s standhv
plant supplying steam to central
heating systems. Broili 726
— Oil engine for off-peak load •SSI
— Opelousas' municipal lighting *41
— Palo Alto Diesel engine. Haas. . . . *502
— Paper-mill plants. Holmes 758
— Pre-efflciency. Willis 500
— Quincy Market Co., Boston *9
— Record keeping. White 243
— Salmon River. Rogers *320
■ — Scranton — Wash. Ave. plant. Rog-
ers ♦ *r, s
— Seattle municipal lighting plant,
•182, News notes 71, 3S7
— Single-unit power plants. Haw-
kins S55
— Standard Iron Co »49
— Station design. Analyzing 340
— Stetson Co., J. B *112
— Topeka municipal-plant costs 665
— Uniflow engines, Los Angeles »74S
— Western Newspaper Union «2
— Westport power plant. Baltimore. .«390
— Winchester, Ind.. Diesel-engine
central station. Wilson *562
Pre-efflciency. Willis 500
Precision Inst. Co.'s boiler-efficiency
kit »84
Pressure, Absolute, in inches of vac-
uum f791
Pressure for running noncondensing.1555
Pressure pump operating without
accumulator. Palmer 852
Pressures, Relative economy with
different initial 1895 ■
l'age
"Piessurlokd" water gage '157
Prey to the elements. Connor •667
Priming centrifugal pumps. Jones,
•294, Palmer 481. Roche '550, Pur-
cell, Solomon 01.T>, Carl, Noble 788,
Ivens priming valve, etc. Ivens...,SS0
Prince-Groff water gage *167
Principles vs. details 7 :> 1
Printers' engine, Buckeye. McCo
nell *65
Printing otlice. Govt., power plant.
Tuck »576
Prism that refracts our vision — Car-
toon. Smith «797
Prismoidal formula application 1487
Producer. See "Gas," "Engine, In-
ternal-Combustion.''
Profession, Choosing a 581
Promotion, Who gets? Farnsworth,
172, Blanchard 308
Public hearings, Engineer at 409
Public-service decisions (see also
"Rate") 387
Public-utility legislation. Wash 247
Pulley covering, Gripwell 334
Pulley hubs. Shaft breakage in 1311
Pulley, Shaft coupling made into.
Strother 134
Pulsations in steam pipes. Johnson. 620
PUMP
s> e a tso "Air pump."
■Air-chamber supply, Maintaining. .1487
-Air, Compressed, Pumping with... 120
—Air-lift efficiency. Ivens *843
— Booster pump test, Roseland
pumping station. Chicago *338
— Brine pump, Good service from. In-
dependent Packing Co.'s *304
— Capacity of pump 1895
— Centrifugal pump air bound. Mc-
Morrow *S54
— Centrifugal-pump capacity, Tem-
perature effect on. Howard *406
— Centrifugal pump, Goulds single-
stage *257
— Centrifugal pump, Hill-Tripp »634
— Centrifugal pumps for boiler feed;
effect on turbine. Kessler, Terry
Steam Turbine Co 133
— Centrifugal pumps. Priming. Jones,
•294, Palmer 4S1. Solomon 615, Re-
lief valve, etc. Poche •550, Ejector
lift. Purcell 615, Carl, Noble 7SS,
Use of Ivens priming valve, etc.
Ivens »S80
— Centrifugal pumps. Testing small.
Blish »370, Daugherty 551, Wood..»616
— Crippled pump, Running — Plunger
removed and opening capped.
Pagett . . *852
Cylinder lengths. Relative !t4S7
— Dayton power pump *165
— Delivery in duty trials 1349
— Detroit municipal pumping sta-
tions. Wilson *150
— Direct-Acting Steam Pumps.
Nickel 1695
— Discharge pipe. Smaller, worked
better 1759
— Discharge pipe with drop leg. Pres-
sure in J209
— Dredge pump handles ashes. Hav-
ard »580
— Dry-vacuum pump helps in repairs.
Hurst 486
— Duplex pump. Steam compression
in 1487
— Duplex-pump piston speed 1857
— Duty of steam pump 1521, 750
— Electric control of pumps. Auto-
matic. Kirchgasser *S11
— Elevator-pump notes. Rogers. .. ,*741
— Emergency repair of crack: plug
extended into lining. Whitaker. . . »724
— Feed-pump size 1555
— Graphite pump. Operating. Wiley. *617
— Hot-water pumping. Rogers *169
— Hydraulic pump. Triplex. Watson-
Stillman «18
— Hydraulic pumps. Power and ca-
pacity of — Tables. Lachmann 89
— Hydraulic single-acting triplex
pump, Hyd. Press Mfg. Co.'s '462
— Improperly finished pumps: stuff-
ing-boxes. Haines 99
— Irrigation and Pumping. Fleming. 1356
— Kingsford double-flow pump «85
— Luitwieler double-acting triplex
Pump »75n
— Meter and pump trouble. Powers. 348
— Minidoka irrigation plant '422
— Motor speed, Changing. Banklu-ad . *583
— Oil, Crude, Centrifugal pump for.
Morrison «454
— Piston speed assumed in formula. .1311
— Plunger accident repaired. Wal-
lace *691
— Plunger weight when submerged. .1417
— Plungers, Renewing — Making of
pipe. Fleblg «SK3
— Power required for pump 1759
— Pressure pump operating without
accumulator Palmer 852
— Pump would not run. Carpenter. .«721
— Pumping engines. Moving, by water
pressure. Binns «79ft
12
POWER
January 1 to June 30, 1915
Page
PUMP — Continued
— Regulator, Pump. Bullard *T04
— Running lame, Causes of J13o
— Saving in pump room — Overflow
changed, etc. Dixon l'l
— Sawmill pumping rig made from
fragments. Noble b»3
— Selecting pump for general service
— Various types. Hubbard '198,
519, Lent 345, Newcomb »19
• — Separator drain as steam supply to
pump. Horsf eld 1 ' -
— Sewage pumping, Baltimore. Rog-
ers ' »
■ — Sewage-pumping station. Fairview.
Detroit — Angle-compound centrifu-
gal units. Wilson •286
— Short-stroke of pump UaV
— Size of pump required ±!>_u
— Slippage. Calculating. Robinson,
447, Practical test for it. Binns 4ol,
Hyde *46S
—Steam consumption in pumping... 940
— Steam flow, Testing t|95
— Steam-pump pumping height J693
— Steam to operate pump. Calculating ;2S
• — Strainer in suction. Kolar *oo4
■ — Stuffing-box depth; bushing to cure
leakage. Sherman •481, Pearce... 785
— Submerged-piston vs. straightway . t ,91
— Submerged pumps, Recedence and
pressure readings from. Coving-
ton *4'3
— Triplex plunger-pump capacity ... +13o
— Vacuum pump, Water-hammer in.
O'Donnell *98
— Valve studs, Repairing — Head used
as nut. Ruppert *722
— Valve, Voorhees "Rub-Steel" '803
—Valves, Rubber, Facing up. Cur-
ren ^22
— Vapor-bound water end. Rezniem 30
— Water horsepower of pump $693
— Water supply — Plant design *32
Purifier, Bayer feed-water *400
Purposeful anecdotes *37, «319, *661,
•S29, Discussion. Garlick 620
"Push, don't knock." Allison *593
Pyrometer, Copper-ball 1135
Pyrometer, Wilson-Maeulen "Tapa-
log" recording *541
Pyrometers, Radiation, Characteris-
tics of. Bureau of Standards 8S2
Pyrometers, Testing and repairing.
Lucas *712
Question puzzling to some . .. 539
Quincv Market refrigerating station,
Boston *9
Quinn, John, Death of *247
Quizz, Will, Jr 5, »56, 257, 453, 707
Radiator valve, Adsco graduated. ... *115
Radiator would not work. Why
Binns *414
Railroad-supply expenditures 835
Railway and power plant, Harris-
burg. 111. Wilson '698
Railwav Master Mechanics' Asso.... 865
Railway, Norfolk & Western, electri-
fication *S30
Railway traction, S-cylinder gasoline
engine for. Chatain *214
Raise. How I earned my *661
Randolph. Constant-current trans-
former *153, High-tension switch-
ing systems *434
Raney. Automatic reclosing circuit-
breaker *108
Rate. See also "Central station," etc.
Rate, Computation of. Carman 419
Rate, Municipal. Two Harbors 444
Rate, Ottawa electric 727
Rate publicity ordered, N. T 355
Rateau mixed-pressure turbine con-
trol *430
Rates — Columbus municipal light
plant 354
Rates, Electric-light. Chandler 347
Rates, Electric, Pasadena S01
Rates — Govt, power buying 636
Rates. Mass. electric, discussed 2^2,
Discrimination. Jackson *549
Rates, N. T. Edison 340, 386
Rates. Reasons for different: ice as
illustration. Seed *3S3. Jackson,
Everett 550, Robinson. Ware 6S4
Rates, St. Louis. Protest against.... 560
Rates, etc.. Seattle 71, »1S2, 387
Reactance-resistance tables 705, 737
Realigning belt-driven generator.
Walchli *892
Reardon. CO- and character of fuel. 574
Recedence and pressure readings
from submerged pumps. Coving-
ton *473
Receiver oil skimmer. Waldron *3fl
Record keeping. Power-plant. White 24H
Record system, Sargent's Wharf ^ll
Reducing valve. See "Valve."
Page
REFRIGERATION
— Air testing in refrigeration plant.
Solomon 839
— Am. Asso. of Refrigeration '7^»
— Ammonia as heat vehicle. John-
son - ■ ' - '
— Ammonia-compressor alarm. Rob-
ertson 81°
--Ammonia-compressor crank bore,
Enlarging. Cunningham '633
— Ammonia-compressor diagrams —
Throttled indicator cock. East-
wood '6SS
— Ammonia-compressor piston rod.
Lubricating. Thurston »64 <
— Ammonia compressor — Replacing
broken capscrews. Solomon *414,
Johnson, Mellen 5a3
— Ammonia-compressor trouble from
throttled suction line. Thurston .. *2 , 4
— Ammonia-compressor valves. Gas-
kets for plugs of. Solomon 61,
Losh 241
— Ammonia compressors, Power re-
quirements of; charts. McBT.ee. . . .*15S
— Ammonia diagrams. Comment on.
Ophiils 204
—Ammonia diagrams. Incorrect.
Larkin *415
— Ammonia helmet. Air hose and
bucket as. Robertson 518
—Ammonia leaks, Detecting. Thurs-
ton 101
— -Ammonia stuffing-boxes. Rogers. 'SiO
— Brine pump, Good service from,
Independent Packing Co.'s *304
— Capacitv in refrigerating plant,
Getting — Handling ammonia; oper-
ating expansion valves; pipe insu-
lation. Solomon S02
— Chicago section, A. S. M. E. — Coch-
rane on ice making as byproduct
for central stations; Luhr on re-
frigeration vs. heating; Witten-
meier on CO. machines; Loyd on
central station's viewpoint; Voor-
hees on multiple-effect compres-
sion 489
— Cleanliness in refrigeration plants 784
— Coils, Oxyacetvlene-welded. . .*S10, 81,
— Costs, Initial and operating, of re-
frigeration plants. Kehoe 710
— Don'ts for refrigerating engineers.
Thurston 607
— Ice and salt action 166
— Ice, Different rates for. Seed 3S3,
Jackson, Everett 550, Robinson,
Ware 6S4
— Ice-fusion heat and specific heat.
Dickinson, Osborne 565
■ — Ice-making plants in U. S 659
— Ice-plant engineers' precautions. . 659
— Ice plants not immune from acci-
dents "59
— Losses, Inconspicuous, in refriger-
ating plants — Heat transmission
leaks. Neff 778
— Lubeck refrigeration-plant per-
formance. Stetefeld 212
— Overhauling refrigeration plant,
Suggestions for — Finding leaks,
etc. Thurston 328
— Quincy Market Cold Storage &
Warehouse Co.'s Sargent's Wharf
plant, Boston — Largest refrigerat-
ing system — Recording brine gage;
electrical equipment: labor: rec-
ords: ammonia condensers, tide
gage. etc. Bromley *9
— Results, Getting best 94
— Safetv operating refrigerating
plants — Safety valve which raises
governor: vacuum breaker and
stop. etc. Geare *307
— Safetv in handling refrigerants;
X. Y. Cy. regulations: safety
valves, etc. Solomon 170
— Safetv in refrig. plants 679
— Sanitary Refrigeration and Ice^
Making. Cnsgrove t3SS
— Testing system with air 659
— Water, Relative, required by dif-
ferent systems. G. B. $311, Bas-
com 44i
Regenerative braking, Norfolk &
Western •830
Regulator. See also "Feed-water."
etc.
Regulator. Pump. Bullard *7o4
Regulators — Automatic electric pump
control *VI1
Reordway gage-glass reflector *82D
Repair job. Ingenious. Kilday *520
Report forms. Sarsent's Wharf *12
Reports. Cutting "lumber" out of.... 752
Research and equipment engineering 339
Reservoir-indicating gage. Lee *7.->5
Resistances. Connecting. Horton. . . '649
Return trap. See "Trap."
Returns. Receiver of. should be
vented $655
Reversed field coils. Parham 892
Review, The year's 21, 157
Richards. Return-pipe compressed-
air practice *224
Richardson-Phenix oil filter *606, Oil
and graphite cylinder lubricator. .»7S0
Page
Ridgway steam turbine •566
Rittmans gasoline process 513
Rivers. See "Water power."
Riveted joints under stress, Behavior
of. Howard 216
Robertson. Ammonia-compressor
alarm gjf
Robie. Core loss in series motor. . . .» 771
Robinson. Powdered coal 793
Rod coupling. Quarter turn, Hall s
•17, Schloss 310, McClure, Sand-
strom 683
Roger, D. L. Small marine power
plant *1?1
Rogers, T. J. Elevator-pump notes. »741
Rogers, W. O. Baltimore sewage-
pumping plant *76, Stetson power
plant '112, Hunter, Hoisting engi-
neer »160, Salmon River plant »320,
Cos Cob plant extension *3oS,
Westport power plant, Baltimore,
addition '390. Bessemer Coal &
Coke Co.'s boiler plant •79£. 817,
Washington Ave. plant, Scranton 'SeS
Rolling-mill drive, steam-turbine,
Carpenter Steel Co.'s 455, 541
Rolling-mill engine wrecked 180
Roney stokers — Furnace changes.
•92, 276
Rosencrants. Chimneys for oil- and
coal-burning plants 637
Roslyn, New Hotel, plant •748
Ross expansion joint 37o
Rotary converter. See "Converter.
Roueche. Oxyacetylene welding in
pipe work '. '808, 817
Royal road, There is no 409
"Rub-Steel" pump valve •803
Rubber expansion joints '632
Ruston convertible combustion en-
gine '557
S
Safe Guard gage-glass reflector, Re-
ordway 835
Safe piping 581
Safeguarding bus room 64b
Safely operating refrigerating plants.
Geare "307
Safety alarm. Ammonia-compressor. S15
Safety code, National elec 717
Safety devices. Elevator-door 345
Safety devices, Testing out. Mack-
ing 134
Safety — First-aid jar »185, 202
Safety-First water column *472
Safety in handling refrigerants. Sol-
omon 170
Safety in refrigerating plants 679
Safety — N. Y. Cent, wins Harriman
medal 282
Safety suggestions 128
Safety valve. See "Valve."
Safety — Warning sign. Skinner. .. .*S55
St. Louis rate protest 560
Salary, Engineers' . .18, 26, 201, Fac-
tors in it 613
Salesmanship, Engineers.' Pohlman. 723
Salesmen — Manager's troubles. Wel-
ler »421. Salesmen's reply. Dunk-
lev *'31
Salfeld. Petter oil-engine test 405
Salmon. F. W. Steam-engine pipes,
88, Concrete-filled engine beds «94,
Air-compressor cylinder ratios. ... *472
Salmon River plant. Rogers *320
Saloon — Cartoon 'Ill
Salt in fireclay *209
"San Diego" boiler explosion 456
San Francisco. See "Panama-Pa-
Sand for cleaning hands. Benefiel. . 854
Sargent's Wharf refrig. station *9
Saw, Hack, blade, Atkins nonbreak-
able '401
Sawmill boiler exploded *195
Sawmill engineering. Noble *6S3
Sawmill machinerv. etc. Blanchard . 134
Scale removal, Waterjacket. Hen-
drv *7S7. Morrison 856
Schieren. C. A.. Death of '388
Schlichter Co.'s floating chimney .... •940
Schlotter blower. Gradenwitz «261
Schiitte ,t Koerting — Oil cooler *564.
Make Dinkel trap 795. Electrically
> • rated stop valve •S40, Soot con-
veyor *Si6
Scotch Engineers and Shipbuilders.
509. 523
Scott medal award 110
Scranton, Penn. — Washington Ave.
power plant. Rogers '868
Screens. Traveling, for circulating
water, at Delray. Hirshfeld. . . . . *333
Screws. Replacing broken cap. Solo-
mon '414, Johnson 553
Seattle municipal lighting plant.
Kidston »182, News notes 71. 3S7
Secretary of Commerce' report 478
Self-contained engine. Buckeye *65
Separator drain as steam supply to
pump. Horsfeld 172
Separator, Oil. failed to work —Rey-
nolds'. Robertson, McLaren 452
Separator. Oil. trouble. Goodwin
•207, Meinzer, Durand, Nelson, • 344,
Metz 3S4
January 1 to June 30, L915
POWER
L3
Page
Seventy-Fourth St. station turbines.
N. Y *527. '528, 547
Sewage pumping, Balto. Rogers.... *76
Sewage-pumping statiun, Fairview,
Detroit. Wilson '286
Shaft breakage in pulley hubs {311
Shaft coupling. Quarter-turn, Hall's
•117, Schloss 310, McClure, Sand-
Strom 683
Shaft, Iron, Torsional deflection of.. 1759
Ship, Cvlinder-head repair aboard.
Dobson *691
Ship propulsion. Electric. Emmet.. 657
Ships, Foreign-built, registered 369
Shrinkage during solidification 316
Sight glass in overflow pipe. Hurst. *690
Sign, A warning. Skinner *855
Signal-circuit make-a nd-break.
King '725
Simmering. Steam-turbine data 750,
Fans 816
Simplex condensation meter *569
Simplex emergency jack *S46
unit power plants. Hawkins 855
Skepticism as an asset 446
Skinner. Auxiliary exhaust valves
on uniflow engines *448, '515
Slack, Loss by use of. Biehl 208
Slant, The wrong. Sandstrom 310
Slippage, Punlp 447, 451, *468
Small. In Cuba 83
Smelter-smoke elimination 282
Smith. A. \Y. Materials of Machines. t796
Smith. G. O.. on legislative progress. 751
Smith, M. B. Furnace-change re-
sults '92, 276, Purchase of coal. . . . *235
Smoke agitation in Slowville. Swope 236
Smoke and boiler settings. See also
"Boiler," "Monnett."
Smoke, Smelter, elimination. Bureau
of Mines 282
Smoke-stack. See "Stack," "Chim-
ney."
Smoke — Year's review 23
Smlling's gasoline process 513
Soda ash for scale 1135
Solomon. Getting capacity in refrig-
erating plant 802. Air testing in
.ration plant 839
Soot, 238, Removal. Blessing, Priefer . *615
Soot conveyor, Schutte & Koerting. .'876
Southern 111. Ry. & Power Co »698
Southwark-Harris Diesel engine. .. *877
Spanish libra. Weight of 1895
Spark-plug ignition. Israel *258
Specific gravities and Baume de-
grees 1587
Specific heat and heat of ice fusion.
Dickinson, Osborne 565
Specifications. Good 237, 514
Speed characteristics of D.C. motors.
Bennett '125
Speed of 3-phase induction motor,
Changing. Bankhead *583
Speeds, Peripheral. Halliwell 815
Spouting velocity of liquid ±791
Spring tension. More, on packing.
Sheehan «683
Spring- winding fixture. Young '692
Springfield (Mo.) G. & E. Co 57
Stack. See also "Chimney."
Stack and breeching minimizing
draft. Union Brewerv *662
Stack, Art and the steel 613
Stack draft explained. Hirshfeld . . . *677
Stack fall. Jamaica — Deadman
broke »139
Stack, Steel, Cutting down with oxy-
acetylene. St. L. & S. F. R.R. shops.
Allen »888
Stacks mounted on boiler settings. . 1791
Stacks, Smoke. Inside and outside,
of two Chicago buildings. Compli-
cated connection '643
Stacks, Storm demolished two, Mo-
berly. Mo. Doehring 894
Staving. Handy. Sheehan «204
Standard Iron Co.'s steam-turbine
power plant. Thomas *49
Standby plant supplying steam to
central heating system. Broili... 726
Start. When gas engine will not.
Percy 299
Start, Why D.C. motors fail' to." An-
nett M94. *230. Plimpton 452
Starter, Burned-nut. Horton «585
Starting — Contactor closed and
opened. Horton «208
Starting small motor. Griscom »60,
Strong 30S. Fredericks 345
Station design. Analyzing 340
Stator connections. Wrong. Horton. 893
Stay-bolt breakage. Firebox- ±F,S7
Staying furnace arch. Hawkins .... »600
Steam. See also "Roiler," "Engine."
"Turbine." "Condenser," "Pump,"
"Piping," "Heating," "Gage,"
Ejector," "Superheat."
Steam and water. Relative volumes. 1135
Steam Charts. Ellenwnod tl4S
Steam coil in tank. Noble »75R
Steam cost. Strong 133. Howard 273
Steam costs. 6600-hp. plant. Philo...368
Steam discharge to vat 1385
Steam. Exhaust. Use of. Stetson
plant .112
Steam-flow meter. Hn. constants for
G. E. tvpe F. Collins «773
Page
Steam flow. Testing 1895
Steam flow through orifice 660
Steam generation in wood-distilling
plant. Eddy »846
Steam-line specifications. Craft.... 612
Steam lines, Clean new. Strong. 785. 889
Steam, Live, ash ejector. Jorgenson,
169, Burns, Clevenstine '240,
Pearce *411
Steam meter. Biddle "Cournon" *545
Steam nozzles. ouizz «56
Steam — Old standby. Strohm *561
Steam-power units, Forty years' ad-
vance in *302
Steam pressures, flywheel risks, pis-
ton speed 548. Williams 585, Jones. 755
Steam quality by separating calorim-
eter 1823
Steam quality near water surface. .{102
Steam requirements. Comparing,
with available exhaust — Plant de-
sign *66
Steam temperature, reduced pres-
sure 1311
Steam, Total heat of ±277
"Steam," "vapor," "gas." Sandstrom 97
Steam, Wetter, requires more feed
water ±277
Steam, Wire-drawn saturated 679
Steel — Boiler-plate diagonal-strength
tests. Macdonald *779
Steel-mill turbine 455, 541
Step-bearing accumulator. Bank-
head 1 «265
Stetefeld. Lubeck refrigeration
plant 212
Stetson power plant. Rogers *112
Stewart. Wrought-iron and steel
tubes 523
Stifel brewery plant «662
Stirling boiler draft readings. Viall '44
Stirling boiler tests — Furnace
changes *92, 276
Stoker- and hand-fired boilers. Com-
parative tests of, Norton Co.'s.
Knowlton *300
Stoker, Kincaid, New *42
Stokers, Ballade of. Taylor 756
Stokers burning cheap fuel 1385
Stokers for locomotives — Buell's re-
port 817, 827
Stokers, Mechanical, Gate area with.jl35
Stokers, Metallurgical furnace. Mon-
nett «196, »432
Stokers, Roney — Furnace changes »92, 276
Stokers, Underfeed. Monnett — Cor-
rection as to Combustion Engineer-
ing Co.'s stoker. Van Brunt '132
Stoney. Turbine vacuum effect *312
Stop acts when rod breaks *375
Stop control. Governor *8
Stop valve, Electrically operated
Schutte & Koerting — Use for en-
gine operating coal and ash con-
veyor »840
Stop valves, Powell *127
Stops, Engine, for refrigerating sys-
tem. Geare. »307
Storage battery. See "Battery."
Stovel-Carle wiring chart *667
Strainer in pump suction. Kolar...*554
Strainer, Motor-operated twin, El-
liott *8
Street. Recent court decisions 109,
144, 237, 283, 355, 457, 591, 658, 694,
729, 795
Strom, G. Machining piston ring...»353
Strohm. R. T. The leak »149, The old
standby »561
Stromeyer. Elasticity and endurance
of steam pipes *278
Study course, Engineers' »32. '66, 96.
103, 136, *173. *210
Stuffing-box depth; bushing. Sher-
man *4S1, Pearce 785
Stufling-box nut lock Proctor '691
Stuffing-box proportions changed.
Merrell »786
Stuffing-boxes, Ammonia. Rogers. .. *820
Stuffing-boxes. Pump. Haines 99
Stumpf (see also "Una-flow," "Uni-
flow.") Recent development in con-
struction of uniflow engine *396,
•448, *515
Sturtevant turbo undergrate blower *7
Sulzer Diesel engine. Large 636
Sulzer, etc., uniflow engines. Stumpf.
•396. *448, »515
Superheat and volume increase 709
Superheated-steam designation ±791
Superheated steam. Factor of evap-
oration with IS 95
Superheater. Evap. factor with ±31
Superheaters. Heating surface of... 621
Supply houses and engineers 849
Surge tank. Salmon River «320
Swaren. Waterwheel repair *838
Swasey, Ambrose '179
1 la j acetj lene Welding. . . .1592
Switch. Motor-operated, elec. -fur-
nace «2n
Switchboard lugs. Home-made. Ger-
ber »758
Switchboard with vertical-tvpe cir-
cuit-breakers ". »769
Switchboards. Development of 708
Switches, High-voltage oil. series
trip for, Genl. Elec. •304, Crane... 484
Page
Switching systems. High-tension.
Randolph »434
Sword of Damocles '«459
Synthetic fuel 305
Tagliabue C02 Thermoscope 43
Tank and float, Pressure-control. .. .'4X3
Tank, Cylindrical, capacity formula. 294
Tank explosion. Hot-water, in house
at Ilion, N. Y »45i
Tank float and alarm. Cobb »725
Tank flow, Disk to increase. Bu-
chanan *790
Tank-indicating gage. Lee ..'.'.'.'..'. !»765
lank. Steam coil in. Noble »756
rank, Surge, Salmon River »320
lank vents. Reynolds 484
Tank. Water, controller, Green »680
Tank, W ater. controller. Hays »692
tanks — Automatic electric control
of pumps »gu
Tanks, etc., Removing dents from.
Connor 090
Tantalum, Hardness of ........'.' ' 334
'Tapalog" recording pvrometer »54i
Taylor. F. W., Death of 492, Cooper-
ators 9Q2
Technical-literature classification 7S3,' 795
telephone receiver connected to cali-
pers. Carr .521
Temperature, Absolute .'.'. ±521
Temperature effect on centrifugal-
pump capacity. Howard »406
Temperature of mixtures... 1587
Tennessee Power Co 109
Terman. Diagonal-joint strength,
•296 *485
Terminal. Motor had one. Horton.'. «240
terminal pressure. Meaning of... ±791
lerry "return-flow" turbine »426
Testing, Air, in refrigeration plant.
Solomon 039
Testing central-station heating
mains oqq
Te,SoJns,-.for Dc- motor' faults' '•194,
|30, Open circuit. Plimpton 452
Testing lubricating oils. Gill 522
»i!rVF .„s-maU centrifugal pumps.
Bhsh *3,0. Daugherty 551, Wood..»616
Tha}er. Costs in small industrial
power plant 4fi5
Thermometer, History of. Atchison! 575
Thermoscope, Tagliabue CO,. 43
Thermostats, Vacuum heating with-'
out. Crosthwait, Durand 346
"nomas. Standard Iron Co.'s steam-
turbine power plant tta
Threads. Pipe. Stewart ...'.[ 523
threads. Standard pipe— Correction . »94
Three-wire system, Direct-euna-nt
vs. Fox »505
Throttle valve, Lunkenheime'r ' bal-
anced *814
Thurston Compressor trouble 274
Overhauling refrigeration plant]
32S, Don ts for refrigerating engi-
TidTgae.-? Rjocrdinsr HI
Tools, Boiler-retubing. Hawkins'«330 586
Topeka municipal-plant costs 665
loronto Co.'s boiler test.... 73
Torque and horsepower defined."!.' 433
Torsional deflection, iron shaft 1759
lower. Transmission, blown down..»687
Traction-engine boiler exploded.
Beeman »fi1R
Tractor, Gas. power plant! ' HulL '. '. '. '226
Transformer blower. Large Buffalo. «533
Transformer connections. Fox »46
Fredericks »381
Transformer, Constant-current. ' Ran-
_, dolph ,]5,
Transformers, Aluminum Co.'s" ." " »776
Transformers, Auto. Meade... »804
Transformers, Designing small
Meade *262
Tranrformers, Oil-cooled,' " Salmon
Transmission' line'. ' The'.' ' Bradiev.' '. *249
Trap. Expansion. Detroit "Winn" »709
Trap, Expansion steam, redesigned
Auto. S. T. & S. Co.'s "Barton" 3*7
?vSP' £et.urn' Gten'l Condenser Co.'s>193
Tinp. Return. Williams' "Cookson" . «5S8
r£p', sJS?m- Dinkel. Plushovalve
Co.s *644, Made by Schutte &
Koerting 795
Return, for feeding boilers'.
' 1 1 1 DC r t * 4 6 7
Traps. Tilting. Farnswoftli ." .' «io
Trfcks of th- trade. Harris " ' 50
Tube See also "Boiler," "Condens-
er.
Tube leak, stopping heater. Mi]ps..754
Tube-working tools. Hawkins. •330, 586
lubes, Holding power of. Allen... 848
Tubes. Iron feed-water heater 1655
rubes, -O rought-iron and steel.
Stewart 523
Tuck. Govt, printing-office" power
plant *-,7i;
Tungsten-lamp dimmers. ' Waller! ! >491
Tungsten. Uses of 575
14
P 0 W E E
January 1 to June 30. 1915
Page
TURBINE, STEAM
See also "Power plants."
— Accident, Peculiar, kills engineer,
X. Y. Cv. Southard 891
— Blower, Turbo, Sturtevant *7
— Composite tvpe — Various exam-
ples *436
— Cos Cob plant extension; turbine-
driven draft fans with reducing
gear *358
— De Laval turbine speed 815
— Diagrams, Steam-turbine; velocity.
Low *596, «650
— Dimensions, weights and costs of
steam turbines. Potter, Simmering 750
. — Efficiency and size of steam tur-
bines— Scotch paper. Golder 247
— Exhaust-casing blowout. Boston
Mfg. Co 623
— Failure, Cause of turbine. Southern
Pacific Co.'s 659
— Field connections. Neglected to
change. Eismann *242
— Gear. Reduction. Turbo-Gear Co.'s. *887
— Interborough Rapid Transit Co.'s
30.000-kw. cross-compound West-
inghouse turbines. 74th St., N. Y.,
•527, 547. Bromley *52S. Power per
boiler hp 130
— Jenckes low-pressure turbine plant,
Synchronous motor in 47S
— Kalamazoo lighting plant; auxili-
ary exhaust steam in lower stages
of turbines *218
— Lining up small turbine sets. Hur-
ley *714
— Low-pressure turbine manifesta-
tion— Probable operating condi-
tions to consider in selection.
Benedict «326
— Mexican turbine installation, Dos
Estrellas mine. Klemm *192
— Minidoka irrigation pumping sta-
tions *422
— Mixed-pressure turbine and con-
denser outfit, Columbia Plate Glass
Co «295
— Modern Curtis and Parsons tur-
bines compared with Centennial
Corliss engine *302
— Oiling system, Changes. Johnson *583
—Partial-load loss chart *638
— P u m p s, Centrifugal — Effect on
driving turbine. Kessler 133
— Ridgway Rateau steam turbine. ,*566
— Seranton electric power plant ... .*868
— Seattle municipal lighting plant.. *182
— Small condensing turbines — Terry
"return-flow"; charts showing ef-
fects of varying wheel dimensions,
etc.; windage: link-motion diagrams
for Rateau mixed-pressure control;
labyrinth-gland formula: pipe con-
nections; effect of finishing blades;
various points of design *426
— Standard Iron Co.'s steam-turbine
power plant; turbo blower *49
— Steam Turbines. Moyer f591
— Steam turbines — Their principles
and operation. Bromley «626, Aus-
tin, Tooker 789
- — Steel mill, De Laval low-pressure
turbine at Carpenter — Rolling-mill
drive through reduction gears 455, 541
— Step-bearing accumulator for ver-
tical turbine. Puget Sound navy
yard. Bankhead *265
— Stetson plant mixed-pressure tur-
bine. Increasing capacity by *112
— Turbo-electrical and triple-expan-
sion engines compared on Swedish
steamers 287
— Vacuum, Effect of. in land and
marine turbines; thermal charts,
etc. — Paper before Inst. Mech. En-
gineers. England. Stoney *312
— Vacuum, Most economical. Her-
schel .. . »744
— Vibration due to missing blades.. *347
— Warships, Turbines in 492
■ — Westport plant, Baltimore »390
— Year's review 21
Turbine, Water. See "Water power."
Turbo. See "Air pump," "Blower,"
"Fan." "Pump," "Turbine."
Two ways of going to work. Elmen-
dorf »493, 515
r
Ulrich, Fred, Death of «36
Una-flow engines, American 22, 157
Uniflow engine construction, Recent
development in — Sulzer's. Stumpf
•396, Auxiliarv exhaust valves.
Skinner *44S, Turnwald »515
Uniflow engine, Nordberg *118
Uniflow or una-flow 201, Trump 482
Uniflow plant. First, on Pacific Coast
— Universal engines in New Hotel
Roslyn, Los Angeles *748
Uniflow steam engine — Principles. .. *570
Union Brewery boiler plant. Wilson,
•662, S20
U. S. Bureau of Mines t2S2, t284,
1317, t31S, t796
U. S. Bureau of Standards — Fixing
horsepower 343, Aneroid calori-
meter 622, Elec. safety code 717,
Radiation pyrometers 882
L". S. employment offices 590
U. S. Geol. Survey exhibits 3S7
U. S. Govt, as power buyer 636
U. S. Govt, printing-office power
plant. Tuck »576
V. S. Navy composition metal 1655,
Boiler compound 1:655
United Piece Dye Works' steam
piping. Collins *2SS, Erratum... 401
Universal Unaflow engines *74S
University. See also state names, etc.
University College, England, heating
and ventilating experimental work 897
Uptake, Steel, Corrosion of $655
Vacuum. See also "Heating and ven-
tilation," "Condenser" and cross-
refeernces from it.
Vacuum ash-handling systems, Op-
erating cost. Girtanner-Daviess,
Miller 206, 412, Sandstrom. Prentiss
412. At Union Brewery «6S4, Miller,
Girtanner-Daviess 820
Vacuum breakers, Ammonia-system '307
Vacuum chart, showing losses «638
Vacuum fluid cooler *542
Vacuum heating systems. Durand. . 605
Vacuum helps in repairs. Hurst.... 486
Vacuum in turbines, Effect of. Stoney «312
Vacuum most economical for tur-
bines. Herschel *744
Vacuum not ascertainable from tem-
perature $555
Vacuum pipe repaired. Sword *64S
Vacuum pump water-hammer. O'Don-
nell »9S
Vacuum, Satisfactory average. Smith 341
VALVE
— Air-compressor feather-valve test,
Forty-million-revolution, Laidlaw-
Dunn-Gordon *537
-—Air compressors, High-speed, Plate
valves for. McFadden *366, Blount 517
— Ammonia-compressor valves. Gas-
kets for plugs of. Solomon 61, Losh 241
— Back-pressure valves, Drains above.
Reynolds 205
— Ball engine valve, Reseating. Jan-
net «51S
— Check-valve action. Lack of syn-
chronism in. Jeter *48, McXabb. . 242
— Corliss exhaust valve, Broken.
Ginther *S22
— Corliss valve-bonnet repair. Pow-
ers *552
— Disk, New composition, Jenkins.. 40
— Exhaust valves. Clattering. . t3S5, 1693
— Handle, "Kantsplit," Holton-
Abbott »665
— Hydraulic valve. New «13S
— Leaky valves in water system;
tank and float to control pressure.
Howell «4S3
— Multiport flow valve, Harrison
Safety Boiler Wks.' "Cochrane" . .*50S
— Packing, Metallic, for valve stems.
Farnsworth *64S
— Powell "Irenew" valve *444
— Priming valve, Ivens *881
— Pump-valve studs, Repairing. Rup-
pert »722
— Pump valve, Voorhees "Rub-Steel" *S03
— Pump valves, Rubber, Facing up.
Curren 822
— Radiator valve, Adsco graduated. .*115
— Reducing-valve chatter +3S5
— Reducing valve used with hot-
water tank that exploded *451
— Reducing valves, Using 680
— Relief valve — Priming cent. pump. *550
— Relief valves. Heater. Dempsey . .«692
— Safety valve, Ammonia, which
raises governor. Geare *307
— Safety-valve capacity 706
— Safety valve for air tank 1655
— Safety-valve overloading; Thorn-
hill explosion 2^2
— Safety-valve rules, Lloyds 716
— Safety-valve specifications, A. S. M.
E. Carhart 81, Perkins 241, Capacity 3S"
— Safety valves. Ammonia. Solomon 170
— Safety valves blocked 137
— Safety valves — Discussion of Mac-
Nicoll's paper before Scotch engi-
neers. Carhart 509
— Salmon River penstock valve *323
— Setting 4-valve engine. Wiegand *266
— Slide-valve steam lap J349
— Stop-valve arrangement $209
— Stop valve, Electrically operated
Schiitte & Koerting — Use for en-
gine operating coal and ash con-
veyor *840
— Stop valves, Powell *127
— Supply houses taking valves back S49
— Throttle valve, Lunkenheimer bal-
anced •S'U
Page
VALVE — Continued
— Twisted valve stem, Diagram cor-
rection for. Kjerulff «99
— U niflow engines — Flexible-seat
poppet valves. Stumpf *396, Aux-
iliary exhaust valves Skinner
*44S, Turnwald »515
— Valve-seat smoothing tool made
from file. Miles *891
Van Deventer. Machine Shop Man-
agement f865
Vanadium in steel castings 291
"Vapor," "steam," "gas." Sandstrom 97
Varnish for protecting books 458
Varnishing insulation by air '365
Ventilation. See "Heating and ven-
tilation."
Viall. Draft readings, Stirling boiler.
Viall «44
Vibration due to missing blades.
Hawley *347
Viscosimeters. Gill 522
Vocational Mathematics. Dooley . . .f 796
Voltage on motor, Wrong. Horton.. 267
Von Culin. How to run and install
a Gasoline Engine t317
w
Wages, Engineers'. Pagett IS, Ed.,
26, 201, 613
YS ages, Increasing the men's. Knowl-
ton 852, Ed 850
Wagner. Coal Gas Residuals 1560
Walker, H. B. Govt, furnishes cheap
electricity 228
Walker, W. J. Heat distribution in
gas-engine cylinder *824
Waller. Tungsten-lamp dimmers ..*491
Wanchope. Operating hydroelectric
plants without attendants 407
War, European:
— Engineers and firemen, Tribute to 479
— French industry crippled by Ger-
mans 477
— "Kent's" engine-room performance 574
Ward. Oil-engine tendencies *186,
3S3, 413, Correction 484
Warships, Turbines in 492
Washington State public-utility leg-
islation 247
Washington, University of, to en-
courage water-power development S96
Waste, Branded, Roval Mfg. Co.'s... 674
Waste-heat boilers. Monnett • 196, »432
Water boiler temperatures and sur-
face pressure 590
Water bubblers, Piping. Henry 486
Water, Circulatin g — Traveling
screens at Delray. Hirshfeld *333
Water column. See also "Gage."
Water column, Queer action in. Jor-
gensen '787
Water column — Safety-First alarm.
Engineering Co.'s «472
Water consumption. Interborough
turbine *527
Water cooler. Vacuum «542
Water cooling, Gas engine. Field
*43x, Morrison 583
Water-eooling towers. See also
"Cooling."
Water discharge from hydrant $857
Water distilling with gas-engine ex-
haust. Hayes »205
Water, Feed — Drawing samples. .. -*689
Water, Feed, Quality of $655
Water, Feed, regulator, Eckel Hvdro-
stat ' «466
V\ ater. Feed, regulator, Foster *512
Water, Feed, regulator. McDonough
"World's Best" «S7
Water, Feed, temperature and coal
savins. Quizz 707
Water, Feed, temperatures — Chart of
power-plant losses *63S
Water filter. See "Filter ."
Water flow. Increasing — Disk for
tank outlet. Buchanan *790
Water gage, Recording tide «9
Water-hammer, Draft-tube. Crane *7S9
Water-hammer in blowoff pipes.
Hurst 30, Preventing. Fenwick
♦650, Noble 754
Water-hammer in steam pipes $S57
Water-hammer in vacuum pump.
O'Donnell »9S
Water hardness standards 1:759
Water heater. See "Heater."
Water, High-pressure, for cleaning.
Purcell *60
Water-jacket scale removal. Hendrv
*7S7. Morrison '. S56
Water — Latent heat {311
Water-level control. Hays *692
Water-meter and pump trouble.
Powers 34S
Water meter. Feed. Grit in. Pearce 654
Water meter, Hoppes V-notch *S07
Water meter. Simplex condensation *569
Water meters. Testing flow. Giele.. *69
January 1 to June 30, 1915
Page
WATER POWER
— Alternator coupled to waterwheels,
Test of. McDougal 86
— Baltimore sewage-pumping plant
— Water- wheel-driven generators.. *78
— Big Creek development snapshots *842
— Boise, Ida., Fed. power house. Con-
nor '594
— Chittenden hydro-elec. plant near
Rutland, Vt., Pittsford Power Co.'s *494
— Colorado River Basin T5S0
— Conservation and legislation 57, 72,
129, 144, 246, 445, 480, 514, 582, 752
—Costs, Relative, of steam and hy-
dro-electric power — Testimony be-
fore Senate committee 246
— Draft-tube water-hammer. Crane *789
— Flour-mill waterwheel and elec.
motor drive. Northwestern 492
— Governors' conference, Western... 863
— Horsepower of stream. Calculating 726
— Hydro-electric plant design, Weak
spots in 849
— Hydro-electric plants, Operating,
without attendants. Wanchope... 407
— Hvdro-electric service, Side lights
on .' 783
— Merging hydro-electric interests.. 681
— Millinocket, Maine, project 386
— Montana Power Co 590
—Natl. Elec. Lt. Asso. papers *858
—New Eng. plants' output 827
— Norwegian waterfall concessions.. 781
— Ontario, Potential hydro-electric
development in 794
— River-measurement model exhibit 247
— Rivers, Eastern, Undeveloped pow-
er in; Conn, resources — Geological
Survey papers 246
— Salmon River plant. Rogers. .. .*320
— Standby plant, N. W. Elec. Co.'s,
supplying steam to central heating
system. Broili 726
— Station design, Analyzing — Typical
plant 340
— Tennessee Power Co.'s Sequatchie
Valley transmission 109
— U. S. available water power — Sta-
tistics by states 283
— Unused rights — Washington bill.. 386
— Washington, University of, to en-
courage water-power development 896
— -Waterwheel casing, Condensation
from. Swaren 722
— Waterwheel repair. Emergency,
Java — Lashed with wire cable.
Swaren »838
■ — .Year's review 24
POWEB
Page
Water-pressure difference from tem-
perature difference J385
Water pressure, Moving pumping en-
gines by. Binns '790
Water — Pump regulator. Bullard. . .*754
Water, Relative, required by different
refrigerating systems. G. B. $311,
Bascom 447
Water-reservoir gage. Lee *755
Water rheostat, Starting motors with.
Annett »230
Water seal to prevent gage-glasses
breaking. Schneider *755
Water service, Two-pressure. Wil-
liams '671
Water supply — Automatic electric
control of pumps *811
Water supply — Plant design *32
Water system, Leaky valves in; tank
and float to control pressure.
Howell *483
Water-tank controller. Green *6S0
Water-tank float and alarm. Cobb..*725
Water tank, Steam coil in. Noble.. *756
Water treatment, Harrisburg, Ill....*700
Water — "Vapor," "steam," "gas."
Sandstrom 97
Water, Waste hot, heats feed water.
Hays *55
Water weigher improved. Loef....*687
Water-works, Detroit. Wilson *150
Waters, E. O. Belting calculations.. 543
Watertown Arsenal boiler-plate tests *779
Wraterwheel. See "Water power."
Watson, H. L. Internal-combustion
engine dimensions *672
Watson-Stillman hyd. pump «1S
Watt-hour meter accuracy. Ewing.. 244
Weaver. Piston-fit allowances *245
Weight decrease from immersion. . .J693
Weight of cast-iron pipes 425
Welding and Cutting, Oxyacetylene.
Swingle f592
Welding, Oxyacetylene, in pipe work.
Roueche '80S, 817
Well pumps, Submerged, Recedence
and pressure readings from. Cov-
ington *473
Weller. Troubles of manager. .'421, *731
Wentworth. Thermodynamics of
marine oil engine *145
West Penn Traction Co.'s plant-loss
charts *638
Western Newspaper Union plant.
Wilson »2
Westinghouse, Geo., Tribute to.
Warren f284
Westinghouse portable fault local-
izer *350, 30,000-kw. turbine, Inter-
borough's »527, *528, 547
lb
Page
Westport plant addition. Rogers.. *390
Wheel, Fly. See "Flywheel."
Wheeler turbo air-pump test *442,
•870, Commonwealth Edison's large
surface condenser *474
Whistle air-compressor motor —
Wrong stator connections 893
White, J. D. Condensation in hot-
blast heaters *12S
White, S. J. H. Record keeping.... 243
Wieder hose-clamping tool *478
Wiegand. Setting 4-valve engine. . .*266
Weigher, Liquid, improved. Loef...*687
Will Quizz, Jr 5, »56, 257, 453, 707
Willard plant cooling tower «847
Williams, A. D. Cleveland municipal
lighting plant "292, 306, "373, »463,
•631, Firebrick for boiler furnaces
297, 305, Two-pressure hydraulic
service *671, Home-made cooling
tower *847
Williams, Arthur, Rejoinder of .... 414
Willis, G. F. PreSfflciency 500
Wilson. Western Newspaper Union
plant *2, Karpen plant engine 27,
Small iso. plant pays big dividends
•51, La Salle Hotel plant saving —
Discussion 63, 99, Municipal pump-
ing stations, Detroit •150, Kalama-
zoo municipal plant *218, Fairview
sewage-pumping station *286, Die-
sel-engine central station, Win-
chester, Ind *562, Union Brewery
boiler plant *662, 820, Harrisburg,
111., railway and power plant *698,
Lumber Exchange Bldg. power
plant »764
Winchester, Ind., Diesel-engine cen-
tral station. Wilson *562
Winn expansion trap *709
Winter. Power costs, tenant building 406
Wire resistance and temperature. . .J102
Wiring, Interior. Cook *601, *640,
•666, 702, 736, 891
Witt crude-oil burner *815
Wood-distilling plant, Steam genera-
tion in. Eddy '846
Wood Mills' circuit breaker *20
Worcester Polytech. celebration.... 863
Work, Two ways of going to. El-
mendorf «493, 515
Workmen's compensation states. .. .J759
"World's Best" feed-water regulator *87
Wrench, Adjustable socket. Noble.. *30
Wrench, Automatic quick-acting. . .'504
Wrench, Bayer quick-acting monkey *264
Year's review, The 21, 157
POWER
Vol. il
NEW YORK, JANUARY 5, 1915
No. 1
POWEK
Vol. 41. No. l
•ira. Newspaper Umiom Plaint im
ChicaE©
By Thomas Wilson
SYNOPSIS — Moving an isolated plant having
525 hp. in boilers and JjQO-kw. generating rapacity
while maintaining the service. The operating cost
is less than central-station service. An analysis
of the plant.
In the summer of 1910 the Western Newspaper Union,
which does a general printing and manufacturing busi-
ness on a large scale, moved into a new building at the
corner of Adams and Clinton St.. Chicago. In plan, the
building measured approximately 125x125 ft. and was
eight stories high above the street level. Practically the
entire floor space was occupied by the company, and as
power was required night and day for the presses, steam
for manufacturing and heating, and current for light-
ing, a private plant was installed.
For three years the plant gave a good account of itself,
but late in 1913 the building site was purchased to form
part of a tract on which to erect the new Pennsylvania
station. As the building was to be torn down the mechani-
cal equipment was moved to a building at Desplaines and
Adam St. The latter is five stories high, but as it meas-
ures 150x165 ft., the floor space and cubic contents are
nearly the same as for the building first occupied.
Past Rei obds Favor Isolated Plant
As is common at such times, strenuous efforts were
made by the central station to get its service into the new
building. With the printing company it was a question of
Fk;. 1. Moving One of the Water-Tube Boilers
disposing of the generating equipment and accepting
rates offered or moving the plant and continuing to
generate its current: this question was thoroughly dis-
cussed. Records for three years were available from
which to determine the average loads and the cost of oper-
ation. Using the rate quoted by the central station, it
was an easy matter to obtain an accurate comparison. The
figures are not available, but as the station equipment is
now being moved, of course, the results favored the iso-
lated plant. Factors influencing the decision were twenty-
four-hour service seven days in the week, the use of all ex-
haust steam for heating- except during peak loads and in
the summer months, and a demand for steam at 60 lb.
pressure in the manufacturing processes. It was seldom
Fi.
EOISTING A BOILKI! ONTO A WAGON
that live steam was needed to supplement the exhaust, but
on the coldest mornings of winter it was used to a limited
extent to help heat up the building.
Briefly, the plant equipment consists of three lT5-hp.
water-tube boilers with extension furnaces and coal-hand-
ling equipment, the usual pumps, and in the engine room
three direct-current generating units, one ratea at '200
kw.. a second at 125 kw. and the third at 75 kw. There
are four tandem-gear electric elevators, two for passen-
ger service, with a carrying capacity "I' 2500 lb. at a
speed of 250 ft. per min.. and two 5000-lb. freight ele-
vators designed for a speed of 150 It. per min. For freight
there L- also a 2000-lb. sidewalk lift. A two-pipe vacuum
heating system with 16,000 sq.ft. of radiation was put
in the building.
Moving the Plan i
The above was the power-planl machinery which
had to be moved, and to accomplish it without interrupt-
January 5, 1 9 1 5
T 0 W E R
ing the service it was necessary to work on Saturday
nights and Sundays, when the load was lighter than usual.
The equipment was moved a unit at a time and put into
operation in the new building. At the present writing
more than half of the printing and power-plant machin-
ery has been transferred and is in operation. Two boil-
ers, the largest and smallest generating units and the
switchboard have also been moved. It is intended to com-
plete the work very shortly. A temporary switchboard,
one boiler and the 125-kw. unit keep the old plant in op-
eration. As a safeguard, breakdown emergency service
has been installed. Due to careful planning and work-
ing to schedule, the plant has not lost any time to the
company.
For moving, the smaller apparatus and generating
units were dismantled and then conveyed by wagon to
in a battery and the other set singly. Each has 1740
sq.ft. of heating surface and is equipped with a stoker
having 33 sq.ft. of grate surface. The ratio is 53 to 1.
The operating pressure is 150 lb. gage, although the boil-
t is were designed for 180 lb. At the boiler farthest from
the stack, the breeching is 3 ft. wide by 6 ft. high and
is widened to 5 ft. at the second boiler, giving an
area of 30 sq.ft. The brick stack is 5 ft. in diameter
and is 150 ft. above the grate line. Its sectional area
is 19.635 sq.ft. To the connected grate surface this area
bears a ratio of 1 to 5, a good average figure for Western
coal, and for every horsepower of boiler rating there is
0.037 sq.ft., or 5.3 sq.in. of stack area. The breeching
dimensions are liberal, as the ratio of breeching area to
connected grate is 3 to 10 and of breeching to stack area
3 to 2.
M.
Mm\\\\m.
JUL i
BmSmJ
. ' ,.,«M —~»i .
f.
It !
-...# /
Power'
P^ initliTlTTWfc .W«>
. ' ^i
-'" ('■ ■ -^ m*
%*^^^^~^^mm '
b y/tfUam
?S^H^^
Fig. 3. On the Way to the New Plant
the new site. Wagons also transported the boilers, but
as each weighed 34,000 lb., the task was more difficult.
After a boiler had been disconnected, the settings knocked
down and the furnace removed, it was placed on blocks
and skidded under an opening in the driving court pro-
vided for the passage of machinery. By means of a der-
rick over the opening having the usual block and tackle
and operated by a winch, the boiler was hoisted onto the
wagon, and in much the same way, only with the oper-
ations reversed, it was lowered into the new plant. Figs.
1 to 3 will tell the story.
Boilek Room of the New Plant
Fig. 4 shows the layout of the new plant, which dif-
fers somewhat from the old, although the installation con-
tains the same machinery. In the Dec. 20, 1910, issue
of Power the older plant was described, but as the ar-
rangement differs and additional data are available, a
short analysis of the design may be of interest.
In the present plant two of the boilers will be arranged
As in the old plant, a damper regulator will be ar-
ranged to control the dampers and at the same time the
S] I of the stoker engines, so. that the supply of coal to
the grates will be regulated according to the load condi-
tions. When first set up the boilers developed an effic-
iency of 70 per cent, with coal averaging 11,150 B.t.u.
It is the intention to have complete coal-handling ap-
paratus. Coal is dumped into a bunker, 20x75 and 20 ft.
high, under the driving court. : It will be carried by
wheelbarrow to the boot of an elevator leg delivering
to a one-ton traveling and weighing hopper over the
furnaces. At present the coal is wheeled from the bunker
to the furnaces. A revolving soot blower facilitates clean-
ing and the ashes will be removed by a bucket elevator ris-
ing to the street level and spouting to wagons.
The source of water-supply is the city mains. In win-
ter the returns from the heating system with sufficient
make-up is passed to a closed heater having a capacity
of 16.000 lb. of water per hour. It is handled by either
one of two 7x4-i/>xl0-in. duplex pumps, when exhaust
P 0 W E R
Vol. 41, No. 1
steam is needed for heating, and by a 4x6-in. triplex
motor-driven pump in the summer mouths: the latter
is naturally more economical of steam. The three pumps
are to be so interconnected that any one of them can be
used for boiler feed or house purposes. Connection from
the pumps will be made to a manifold at the side of one
of the boilers, from which point the feed will be con-
trolled. There will also be a city water connection so
that the boilers may be filled conveniently after being
washed out.
Engine Room
Here the three generating units are arranged as shown
in the plan view. The large 200-kw. machine is an angle
compound, 17 and 28 by 11 in., running at 260 r.p.m. The
other two units, 125 and 75 kw., are driven by simple
horizontal engines with cylinders 16x1(1 in. and 14x12 in.
in the order of their size. The speeds are 240 and 275
r.p.m., respectively. Direct current at 230 volts is gen-
crated, and duplicate compensating sets, each of 15-kw
capacity, will supply lighting current at 115 volts. Be-
sides the elevator motors there is a connected motor load
of 450 hp. made up of 175 motors ranging in size from
Vfe to 40 hp. In the old plant — the load conditions will
be practically the same in the new building — the com-
pound unit carried the load during the day. with some
help from the 75-kw. machine during the peaks. The
latter carried the load at night and the 120-kw. unit
was held as a reserve.
Piping
The arrangement of the piping is shown in Fig. 4.
From each boiler 6-in. pipes lead into the top of an
8- and 10-in. header which delivers to a secondary 10-
in. header in the engine room supplying the three units
through 1-, (1- and 5-in. pipes in the order of their size.
A 3-in. pipe to the auxiliaries taps the boiler-room header
and there is also a couple of connections to supply live
steam at reduced pressure to the heating system and the
feed-water heater. The exhaust pipes from the engines
rise at each unit and eventually join overhead in a 12-
in. pipe leading to the heater, the heating system and to
the atmospheric exhaust. The location of the valves and
the subdivision of the piping will be apparent in the plan
view.
It may be of interest to determine the sectional area of
the steam pipes per unit of boiler and engine rating and
the velocities in the engine supply and exhaust piping.
A 6-in. pipe from each boiler allows 0.165 sq.in. per
boiler-horsepower. If the boiler were delivering steam
at its full rating
175 X 30 = 5250 lb. per hr.
or 87.5 per min., would be delivered. At 150-lb. gage
pressure this weight of steam would occupy
2.758 X 87.5 = 241.33 cu.fl.
and the velocity in feet per minute through the pipe
would be
241.33 -i- 0.2006 = 1203
For the engines the following sectional areas of piping
for the supply and exhaust have been allowed per kilo-
watt of rating: 200-kw. unit, supply 0.1937 sq.in., ex-
haust 0.3943 sq.in.; 125-kw. unit, supply 0.2311 sq.in.,
exhaust 0.3099 sq.in. ; 75-kw. unit, supply 0.2667 sq.in.,
exhaust 0.3852 sq.in.
To arrive at the approximate velocity of the steam in
the piping, assume an average operating rate of 40 lb.
per kilowatt-hour for the compound engine and 50 lb.
for the two smaller machines. At full load the compound
engine would use 8000 lb. of steam per hour, or 133 lb.
per min.: the 125-kw. machine 6250 lb. per hr., or 104.2
Ih. per min.. and the smallest unit 3750 11). per hr., or
62.5 lb. per min. At 150 lb. gage the volumes of steam
passing per minute in the same order would amount to
368, 287 and 172 eu.ft. The velocity of the steam supply
in each would then be 1366, 1431 and 1241 ft. per min.,
Power
Fig. 4. Plan of Piping and Generai Layout of the
New Plant
assuming, as is usual, that the How is continuous through-
out the stroke. These velocities average 1346 ft. per
min. as compared with liOOO ft., the average for current
practice. It is evident that the sizes of the supply pipes
are liberal, but at the time the plant was installed it was
the practice to use large piping and relatively low steam
velocities. It must be remembered that with a small re-
ceiver the steam flow would be intermittent and the ve-
locity during admission would be practically four times
as great as previously indicated. Sudden and heavy over
loads and the size of the openings into the cylinder also
influence the size of the piping.
With the exhaust at atmospheric pressure, which would
be the case in the summer months,
133 X ^(1. 79 X 0.87 = 3100 cu.ft.
Januarv 5. 1915
P 0 WEE
of steam per minute would lie discharged from the 200-
kw. unit. The 36.79 is the cubic feel in a pound of steam
at atmospheric pressure and the 0.81 the qualitj of the
steam after expanding adiabatically from L50 lb. gage
to atmospheric pressure. As the area of the 10-in. pipe
in square feet is 0.5476, the velocity of the steam would be
:!100 -r- 0.5476 = 5661 ft. per n
Figuring in the same way, the 125-kw. unit would dis-
charge 3428 cu.ft. of steam at a velocity of 9026 ft. per
mill, and the ;.3-kw. unit 1456 cu.ft. at a velocity of
turbine the tendency has been upward. In these days
a velocity of *000 ft. for the supply is Doi considered ex-
cessive. The exhaust velocity i- usually limited to 4000
ft. to prevent friction in the piping and to hold down the
back pressure.
Besides the equipment just enumerated there is an air
compressor driven by a 20-hp. motor. The machine sup-
plies 100 cu.ft. of air per miu. at LOO lb. pressure for op-
erating i t n system, certain machinery in the
printing and manufacturing plants and for cleaning the
unions machines.
No 1. luipment
3 Boilers
1 Coal elevator . .
1 Coal hopper.
1 Ash elevator
2 Pumps -
1 Pump .
1 Heater
Engine
Maker
1 Motor Direct-current
PRINCIPAL EQUIPMENT OF WESTERN NEWSPAPER ONION PLANT
Kind Size I Operating Conditions
Water-tube 175 hp Generating steam Mechanically fired, natu.al draft. 1 .V >-
_. . , ., - . „ .. , lb. gage.. Atlas Water Tube Boiler Co.
lop feed Roller furnace Mechanically unrated. - - Model Stoker Co
15 tons per hr... Lift coal above furnaces Motor driven Jeffrey Si fg Co
Traveling and weighing 1 ton Weigh coal and feed to furnaces , . Jeffrey Slfg Co
Bucket lOxfi-in. buckets Hoist ashes to street level Motor dm Chain Belt Co
Duplex.... 7x4islO-in Boiler feed . .. .. 158 lb. steam. . . .. Piatt Iron Works
Triplex purser. Ixii-in Boiler feed or house service .. . Driven by 71-hp motoi Dean- Steam Pump Co
Open 16.0001b. per hr. Heat boiler feed. Exhau-' U8deg... The Griscom Russell Co.
Main unit 1501b American Engine & Elect
Main unit 230 volts. 260 r.p.m ... American Engine ft Electric Co
Main unit. 150 lb. steam, 240 r p. m American Engine & Elect
Direct-current. 125-kw Main unit 230 volts, 240 r.p.m American Engine 4 Electric Co
Simple horizontal 14xl2-in Main unit 150 lb. steam, 275 r.p.m. . . American Eneine & Electric Co.
Direct-current 75 kw Main unit 230 volts, 275 r.p.m American Engine & E'ectrir Co
Tandem gear 2.500 1b Passenger eervira 250 ft. per min, 40-hp mot... Western Electric Co
Tandem gear 50001b... Freight 1.50 ft per min. 40-hp. motor . . , Western Electric Co
Two-pipe vacuum. . . 16,000 sq.ft. rad. Heat building Exhaust steam Warren Weh=ter ,v t-
Revolving type. Blow soot off boiler tubes Vulcan Soot Cleaner Co
Single stage horizontal. 6x9Jxli>-in Compressed air for general use 100 cu.ft. per min. at 100 lb. pressure National Brake & Etectr
1 Generator Direct-current
1 Engine Simple horizontal
1 Generator.
1 Engine
1 Generator ...
2 Elevator-
2 Elevator-
1 Heati .
1 Soot blower . . .
1 Air oorj
Angle compound. . . 17x28xl4rin.
200 kw
16xl6-in Main unit 150 lb. steam. 240 i
20 hp
Drivf
■ compressor 220 volts, 860 r.D.m National Brake & Electric Co'
T261 ft. per min. The average of the three exhaust steam
velocities is 7361 ft. per min. This is a little above the
usual velocity allowed in the exhaust piping of an en-
gine, but a slight increase in hack pressure or running
below rating would reduce the volume and consequently
the velocity of the -team.
Velocities in -team-engine piping are largely a matter
of individual opinion. Since the advent of the steam
Water for drinking is doubly filtered ami cooled. It
passes through -ami and paper-disk filters in series ami
is cooled in s coils laid in an ice box. Bub-
bling fountain- an- distributed throughout the build-
Por the new layout of the plant a- well as the old. and
for the moving, Charles G. Atkins, consulting engineer,
is responsible.
'mzs,
SYNOPSIS— How Will got his first ideas of en-
gineering, and later learns that faithful plodding
does not necessarily bring large success. His con-
ference with I'h iff Teller on this occasion was not
of a technical character, but perhaps it was as vital
as any.
"You know, Chief, a boy always has an ideal, and
my ideal was to become an engineer like Heintz, the late
chief engineer at the gas works.
'"When I was a youngster I used to peer longingly
through the engine-room window. Heintz would some-
times allow me in the engine room where I would sit in
rapture watching the moving machinery — and Heintz.
He was a veteran engineer, and my ambition was to he
able to wield the long-spouted oil can like he did. You
know my pet savin-. -Heintz would do it this way' — hut
did he do the best way ? .
"Since Heintzr*8 enforced retirement, practically on char-
ity, some of the dreams of my childhood have been shat-
tered and I have serious doubts about it. Many a I
things are said about Heintz, hut to me they have bro
a flood of doubt. Do I want to follow in his footsteps?
Heintz was a fine old character, and his whole career had
been in the same engine room. His friends always had
seen him in one of three places — at home, in the engine
room, or on the path between the two. He worked even-
Sunday and every holiday; he never had a vacation —
never received an increase of pay.
'T notice that his two -sons are not following engineer-
ing. I am very much bothered as to whether I am on the
right track for my life's work. What do you think,
Chief:'"
"I am triad. Will, that you have so much confidence in
me, but it puts a grave responsibility on me too. Every-
one has periods of doubt, and evidently you do not want to
become an engineer of the Heintz class. It is unfortu-
nate that so little encouragement is offered by some cor-,
porations and that there are men so situated or consti-
Hiat they will never rise above the lowest grade jobs
in any line.
•'It is entirely possible, however, for engineers to work
mable hours, and for them to improve mentally, fi-
nancially and socially. To avoid becoming disappointed
after it is too late to make a change, exert yourself to ac-
quire an engineering education. You will find that the
greatest pleasure comes from improving your mind. Cut
out those things which will surely leave you stranded and
disappointed. You can fire boilers and run an engine and
know next to nothing. You can't get on very far in that
way. The only hope for a young man to escape the medio-
cre life is to educate and advance himself day by dav.
'"There are two elements of greater importance than
G
POWEB
Vol. 41, No. 1
the trade or occupation — one is the boy (or man) and
the other the opportunity or set of conditions surrounding
him. AY hen it comes to averaging the load factor of the
whole lot of us it's going to be surprising to see how near
the maximum some unassuming fellows have been oper-
ating with the equipment they had, and under handicaps
or unavoidable circumstances of which others may have
known nothing.
"I feel sure that you have the right stuff in y<m. son,
to become an engineer worth while, but remember thai
there can be no excellence without great labor. You have
my best wishes and are welcome to any help I can give."
v F. V. Larklnt*
SYNOPSIS — Figures showing what may be ex-
pected of an anthracite suction producer of this
size supplying a four-cylinder^ four-stroke-i
engine under full-load conditions.
During the autumn of 1913 the department of experi-
mental engineering at Lehigh University was tailed upon
TABLE 1. RESULTS OF GAS PRODUCER TEST
Duration of test -1 In-
Kind of coal used Anthracite pea
Height of the producer 0 ft.
In.-idc diameter 5 ft., 8 in.
Area , of grate 25.2 sq.ft.
Air t^pace in grate 29 per cent.
Area of water heating surface in vaporizer 70 sq.ft.
Rated capacity of producer in lb. of coal per hr 250 lb.
Average Pressures and Temperatures
Steam pn.-ssuie in vaporizer , 14 lb.
Gas pr-\ surf i;i main where measured, in. of water. . . . .0.985
Draft in ashpit, in. of water 0. 102
Deg. F.
Temperature of water entering vaporizer. Hill
Temperature of gas in main near producer . 584
Temperature of gas where measured . .... .....50.7
Temperature of air in producer room 67.7
Temperature of water entering scrubber . . 53
Temperature of water leaving scrubber . . 112.9
Weight of dry gas per cu.ft. reduced to 62 deg. and 30 in 0. 066 lb.
Hourly Quantities
Dry coal consumed per hour 206 S lb.
Dry coal consumed per hour per sq.ft. of crate S 2 lb.
Gas delivered per hour . . . . 14.628 cu.ft.
Gas per hour at 62 deg. and 30 in 15,520 cu.ft.
Weight of dry- gas per hour ...... 1,032 lb.
Steam supplied to producer per hour 543 1b.
Water fed to scrubber per hour 2,164 lb.
Ultimate Analysis of Dry Coal Per Cent.
Carbon (C) ..79.21
Hydrogen (H) .2 01
Oxvgen (01 0 (Hi
Nitrogen (N) ....... ... . . 0 B0
Sulphui (St .. 1.32
Ash . . . 17 37
Moisture in sample of coal as received . . . 2 74
Analysis of Ash and Refuse Per Cent.
Carbon .30.99
Earthy matter.. . .60.01
Analysis of Gas by Volume Per Cent.
Carbon dioxide (CO-) . 0 536
Carbon monoxide (CO) 26 760
OxyEen (O) 0 332
Hydrogen (H) 10 944
Marsh gas (CH/t 1 007
Olefiant gas <CHt> 0 051
Sulphur dioxide (.SO J 0 000
Hydrogen sulphide ( H2S) . 0.000
Nitrogen (N) by diffeicncc 61, 370
Calorific Values of Coal, B.t n. per Lb. P I u
fa> Dry m;u by calorimeter 12,363
(b) Wet coal as fired by calorimeter 12,033
(c) Wet coal as fired by Dulong's formula 12,500
Calorific value per lb. of combustible 1 1,960
Calorific Value of (las, B.t.u per Cu.Ft at tij Deg and 30 In.
(a) Bv calorimeter 137
(b) By calculation 13S 4
Economy Results Cu.Fl
Total cu.ft. of gas as calculated per lb. dry coal fired 70 7
Equivalent cu.ft. of gas at i>2 deg. and 30 in. per lb. dry coal 75
Equivalent cu.ft. of gas at 62 dep. and 30 in. per lb. of combustible 104 6
Efficiency Per Cent.
Efficiency of producer based on coal s:; 1
Efficiency of producer based on combustible 0."- 7
Cost of Production
Cost of coal per ton of 2240 lb. delivered $3.25
Cost of coal to produce 10.000 cu.ft. of cas at 62 deg. and 30 in... 0.199
Cost of coal for producing 1,000,000 B.t.u. . «' L451
lb at Balance Based on 1 Lb. of Dry Coal Per Cent.
Heat contained in dry gas gfj
Heat carried away by scrubber <i
Heat unaccounted for, including radiation ...... r>
■Assistant Professor of Mechanical Engineering, Lehigh
University.
to make an acceptance test of a suction producer sup-
plying a 200-hp. gas engine, the object being to ascertain
whether the manufacturers guarantee of capacity, speed
regulation and economy was being fulfilled.
TABLE 2. RESULTS OF GAS ENGINE TEST
Duration of test 24 hr
Make of engine Fairbanks Morse
Type _ Four-stroke cycle
Size Four-cylinder 14ixl8-in
Method of ignition Battery during test, ordinarily magnet"
Rated capacity 200 hp. at 250 r.p.m
Kind of gas (for analysis of gas, see producer test i Mixed producer ga.*
Average Pressures and Temperatures
Pressure of gas near meter, in. of water 0.9S5
Temperature of cooling water Deg. F.
(a) Inlet to cylinders and valves 53.74
(b) Outlet from cylinders .114.56
(c) Outlet from valves ,. .104.95
Temperature of gas near meter 62.3
Temperature of exhaust gases . 1010 23
Gas consumed per hour at 62 deg. and 30 in . 15,520 cu.ft
Cooling water suppUed per hour
(a) To jackets 9,0001b
(b) To valves 475 lb
Analysis of Exhaust Gases bv Volume
Per Cent.
Carbon dioxide (COs) 16.99
Oxygen (02> 1.S4
Carbon monoxide I CO) ... 0 . 50
Nitrogen (by difference )N3 80.67
Indicator Diagrams
Pressure in lb. per sq.in. above atmosphere
(a) Maximum pressure 300
(D) Pressure at end of expansion 25
(c) Exhaust pressure at lowest point 2
Average mean effective pressure in lb. per sq.in 59
Speed and Explosions
Revolutions per minute 230
Average number of explosions per min 478 5
Indicated horsepower 211. S
Brake horsepower 199 . 2
Friction horsepower by difference. . . . 12.6
Percentage lost in friction 5 8
Economy Results
Heat units consumed by engine per hour
Per indicated, horsepower 10,034 B.t.u
Per brake horsepower 10,674 B.t.u
Gas consumed per hour
Per indicated horsepower 73 3 cu.ft.
Per brake horsepower 78 cu.ft.
Dry coal consumed per i.hp.-hr . 0 98 lh
Drv coal consumed per b.hp.-hr 1 04 lb.
Cost per i.hp.-hr $0 00146
Cost per b.hp.-hr SO. 00155
Efficiency
Thermal efficiency ratio Per Cent.
Based on i.hp.-hr
Based on brake horsepower 23.6
Heat Balance Based on B.t.u. per I Hp.
B.t.u. Per Cent
Heal converted into work 2545 25 1
Heat rejected in cooling water ...... 2700 36 B
Heat rejected in exhaust gases 2582 25 8
Heat lost due to moisture formed bv the burning of hydrogen 228 3 2
Heat lost by incomplete combustion 205 2 <i
"Heat unaccounted for. including radiation 1771 17 7
Total heat consumed per i.hp.-hr 10.034 100 0
The plant was put in readiness for the lest by the man-
ufacturer's representative, who installed the test flywheels
and prony brakes and operated the plant during the test.
The university furnished and installed the remainder of
the test apparatus, including meters, pitot tubes, gas-ana-
lyzing apparatus for fuel and exhaust gases, and the gas
calorimeter.
An unusual feature was the means provided to secure
continuous determinations of the calorific value of the
gas. Continuous samples were drawn from the* main by
a water aspirator which delivered water and gas to a
.la ii nary 5, I 9] ■'
P 0 W E E
small tank where the desired pressure was maintained
by regulating the water-outlet valve. The calorimeter
was of the simple Junker type, with Centigrade thermom-
eters, the wet meter reading to thousandths of a cubic
foot, and the water-measuring receptacles graduated in.
cubic centimeters.
Four preliminary runs of approximately ten hours
each at no load, one-fourth, one-half and three-fourths
load, respectively, were made to insure satisfactory oper-
ation of the plant and test apparatus and to bring the
producer up to the condition of every-day operation.
Following these runs the final test was made at full rated
load and without stops for a period of twenty-four hours.
Observations were taken at fifteen-minute intervals dur-
ing all the tests.
Remarks
The gas volumes were calculated from the analyses of
the coal and gases, because the four pitot tubes installed
were so greatly affected by the engine pulsations that their
indications were wholly unreliable.
The high mechanical efficiency is probably due, in part
at least, to the fact that two of the four indicators used
were steam-engine indicators.
It would seem that the manufacturer might arrange to
utilize part of the heat lost in the exhaust gases by taking
the air necessary for combustion from a preheater sur-
rounding the exhaust gases. In this particular case the
owner of the plant can doubtless utilize a sufficient
amount of this heat to furnish the hot water necessary
for shower baths and other purposes.
This oil burner is designed to atomize the fuel oil twice
This burner is manufactured
Burner Co., Kingman, Kan.
s
the Champion Oil
eipg&mfte
A new design of undergrate blower for use where moTe
furnace draft is needed is placed in the boiler brickwork.
In this set (see illustration), which is made by the B. F.
Sturtevant Co., Hyde Park, Boston, Mass., the turbine
is practically identical with the large standard turbines
built by the company. The bearings are provided with
Sturtevant Turbo Undergrate Blower
oil-ring lubrication, and a floating, metallic stuffing-box
prevents steam from getting into the bearings and enables
a back pressure of 15 lb. to be carried.
The new machine is controlled by from one to six noz-
zles, according to the amount of steam required. The
Section through Champion Oil Burneb
during its passage through the burner and also to control
the size and shape of the flame. The illustration is a
sectional view of the burner.
As shown, there are two atomizing chambers. The
steam comes into the first from above and below the oil-
supply pipe, and the mixture then passes to the burner
head. Just before it leaves this head it comes in con-
tact with the two jets of live steam from the two side pipes
which enter the burner head in the second atomizing
(handier, where the mixture is again atomized as it goes to
the mouth of the burner.
In addition to atomizing the oil the second time, the
steam from the two side pipes gives the operator control
of the blaze. By closing the valves on these two pipes
the blaze will shoot straight back into the furnace, but by
opening them the shape of the blaze is controlled. The
burner works in connection with a pump and pressure
tank, is made to fit any furnace, and is easily placed.
fireman can shut off any number of nozzles to regulate
the steam consumption at low loads.
Wrought Iron — Taken for the purpose of general calcula-
tions, the average weight of one cubic foot of wrought iron
is 480 lb. per cu.ft., or 40 lb. per sq.ft. one inch thick.
Steel — The average weight of one cubic foot of steel is
taken as 489.6 lb. per cu.ft., or 40.8 lb. per sq.ft. one inch
thick.
More Gas than Oil — Pennsylvania's supply of gas will out-
last the state's supply of oil, in the opinion of Roswell H.
Johnson, professor of oil and gas production in the School
of Mines in the University of Pittsburgh. Pennsylvania stands
sixth among the states as a consumer of oil and second as a
consumer of gas. Since 1903 the oil supply has been de-
clining, Prof. Johnson declared, while the supply of gas has
been increasing. If there were greater markets, he eays, more
gas could be produced, as the state has large reserves of gas
lying in the deeper sands.
POWER
Yoi. 41, No. 1
BeM Taglhft©Eaeir
This device is designed Eor the purpose of allowing the
governor stop to remain in position to prevent the shut-
ting down of the engine in case of an overload and to re-
move the stop and allow the governor to fall to its lowest
3j
Fig. 1. Details of the Governor-Stop Control
position to stop the engine in ease the governor belt
breaks or runs off the pulley.
Referring to Fig. 1, A represents the governor stop in
a position to reverse the governor with the engine stopped.
The dotted lines show the governor stop in its lowest po-
Fic. 2. Plan- View of the Stop Control
sition. The stop receives motion from the governor-stop
controlling rod B. When the engine is running and the
governor is performing its normal operation, the gov-
ernor stop will rise in its "up position" with the gov-
ernor-control pin B in contact with the arm C of the
stop. If the engine should become suddenly overloaded
the governor will drop to the governor stop and descend
no farther, tints allowing the engine to continue running:
in case the governor bell should break or slip off the pul-
ley, the carriage D would be shifted on the bed by the
weights E. This sliding movement of the carriage causes
the controlling rod A to strike the arm C and to move the
governor stop out of its elevated position, turning it to
the position shown by the dotted lines. Consequently,
when the governor drops, it moves to its lowest position
and stops the engine. The weights also exert a pull on
the governor belt, thus maintaining a proper tension.
The stretching of the belt may alter the position of the
stop control rod .1. and this is compensated for by adjust-
ing the screw rod F (Fig. 2) which passes through the
pin .1.
1H&
Multiple strainers have performed such good service
in connection with water-supply lines, condensers, etc.,
that they are now regarded as desirable in all uptodate
installations.
The shifting of the valves on the small twin strainers
by hand is simple, whereas on the larger units up to 48
Motor-Operated Twin Stbainee
in., the time consumed in changing over from one side
to the other is an item and involves considerable manual
labor. To overcome these objections, the Elliott Co.,
Pittsburgh, Penu., has recently adopted a motor drive
applicable to all its twin strainers of 20 in. and above.
An electric motor is mounted on one end of the strainer
and drives trains of gears communicating with the two
valve stems, friction clutches controlling each valve stem
independently of the other, and also independently of
the motor. Each stem has a device for indicating the po-
sition of each valve. The illustration shows one of the
baskets partially removed for cleaning purposes.
After the baskets are cleaned and replaced and the
doors closed, and it becomes necessary to open up the
baskets on the other side of the strainer for cleaning, the
motor is started, and at full speed one of the friction
(hitches is caused to engage the motor shaft, which moves
the valve off its seat. This clutch is then released and
the other clutch thrown into engagement with the other
shaft, which moves the other valve from its seat. Then
both friction clutches are thrown into engagement with
the motor shaft and the valves are moved together to the
opposite side of the strainer.
When the valves are about an inch from their Beating
January 5. 1915
p o w b b
position, one clutch is thrown out of service and the full
power of the motor ie then employed in seating one valve.
After it is seated, its clutch is released and the other
clutch is thrown into service, which seats the second
valve. The motor is then stopped, the doors opened and
the baskets cleaned.
When it becomes necessary to shift the valves in the
other direction, the rotation of the motor is reversed and
the same operation is repeated.
On a 36-in. strainer the time required to start up the
motors and shift the valves from one side to the other
is 61 seconds, and to take off the doors and. remove the
baskets, clean and replace them, on this size strainer,
requires less than ten minutes. This added to the time
for shifting makes the total time needed to clean a 3fi-
in. twin strainer less than eleven minutes, whereas with
the hand-operated screws the time would be about three
times as Ions. The time element in changing strainer
baskets is important in order to prevent loss of vacuum
and of water-supply, especially when the water strained
contains large quantities of leaves and other foreign sub-
stances during high-water periods.
^iipuniemiil sumdl Mettlhodls in ILf
Refrift'eratiioEii System— V
mi
By Charles H. Bromley
8YNOPSI8 — A novel gage records the height of
brine in the tank, an ordinarily difficult practice
due to precipitation of the calcium. A gage of the
same general design records the height of water
in the condensing water crib, and this together
with the manometer tube connected in the suction
main enables the operator to avoid low water due
In //lugged screens. Turbo-generators furnish en-
ergy for light and power for the plants, warehouses
and Clinton Market. An exceptionally well trained
crew operates the plant, maintains it, and rebuilds
it as it wears out. The record system is most com-
plete. The article concludes with a description of
the lubricating system and ammonia condensers.
Novel Recording Brine Gage
The amount of brine in the suction tank is an indica-
tion of the tightness of the system, for if there is a serious
leak it will not be long before the brine level will drop
perceptibly. To register or record, by pressure by ordi-
Recording chart gage to record
height of liquid above hole in
diaphragm box
Chain to raise
or tower diaphragm
box
Opening to admit pressure
to underside of diaphragm
Fro. 81. Section or Type of Gage for Measuring
Height of Brink and Condenses Cooling Water
nary means, the height of brine in the tank is practically
impossible if accuracy is desired, because in time the cal-
cium settles out and, due to its weight, gives readings
which are too great. To eliminate error due to calcium,
a diaphragm chamber is used in connection with the
recording gage, the outfit being shown in Fig. 81. As the
Fig. 88. Chart Showing Bise and Fall of Tide in
Crib for Condenser Cooling Water
height of liquid above the hole in the bottom of the dia-
phragm box increases it pushes up the diaphragm, made
of dentist's rubber, thus increasing the air pressure on the
recording gage.
Similar Gage Used to Measure Tide
Water for the ammonia and steam condensers is taken
from a crib in which the height is governed by the tide.
The height in the crib was formerly kept track of by a
tide table written on a blackboard in the engine room,
but now a record of the tide and the height of water in
the crib is recorded by the same kind of outfit as used
for measuring the brine. A chart from the tide gage
showing the action of the tide on June IS of this year
Ill
P 0 AY E H
Vol. 41. No. 1
is shown in Fig. 22. Xotice that the maximum high
tides for the day differ by a foot and the low tides by
6 in. There are other interesting features if one has the
time to study them. Below the gage that records the
height of water in the crib is the manometer tube of a
venturi meter. Fig. 23. These two gages tell a man
all he needs to know about the water condition in the
f
If . I Jk
L
.
•
.-
^
i \ rubber floating
on mercury
<3
4
|U
Power
Two 10-kw. induction motor-driven and one 10-kw.
engine-driven, direct-current generators light the station.
Light and power as well as refrigeration are furnished
to some of the warehouses, and Clinton Market gets it.-
light, power and refrigeration from this station. The
switchboard is quite completely fitted, having, besides
other instruments, integrating wattmeters, alternating-
current load-averaging meters, power-factor meter,
graphic voltmeter, syneroscope and a frequency . meter.
The turbine at the right. Fig. 25. has the distinction
of having made a nonstop run for 18 months. The tur-
bines average about 18 lb. steam per kilowatt-hour, and
the cost of current is approximately % cent per kilowatt-
hour at the hoard.
A central . surface condensing system is used. Many
of the tubes in these condensers have been in service
for twelve years and are still in good condition. The
tubes are made of a composition consisting of 88 per
rent, copper, 10 per cent, tin and 2 per cent, lead, a most
unusual composition, for there is seldom more than 1 or 2
per cent, tin and nearly always considerable zinc in con-
denser tubes, except in some of those brought out re-
cently, namely, aluminum bronze, cupro-nickel and Monel
metal. The water in Boston Harbor is quite pure com-
pared to that of the East, Hackensack, Chicago, and
other rivers on which there are large condensing plants.
The feed water and the circulating water are measured
with venturi meter-.
Labor
All labor is departmentized, there being a separate
crew for each division of work; the engineers work eight
- - Ttlumbscre* for
pulling flannel
Fig. 23. Manometer Tube of Yen rum Meter
for Cooling Water Suction Line Placed
below Dial Gage That Records
Height of Water in Cooling
Water Crib
crib and offer him no excuse for losing the water because
of dirty screens, as a plugged screen is immediately in-
dicated. A piece of hard black rubber was put in the
tube and the instrument calibrated with the rubber float-
ing on the mercury. This makes it easy to quickly get
readings.
Electric-Generating Equipment
The two main generating sets are turbine driven and
are each of 500-kw. capacity, of 450 volts and 3600 r.p.m.
Both turbines operate under nearly 29 in. vacuum in
winter, 146 lb. pressure and 125 deg. superheat ; total
temperature, 486 deg. F. Although the superheat at the
boilers is 125 deg. P.. there is a 15-deg. drop between
the superheaters and the turbines. Indicating and re-
cording thermometers are provided in the steam inlet
mid exhaust pipes.
Fig. 24. One of the Perforated Flannel-
Covered C'VLIXDERS ECU: THE Oil. FILTERS
hours and all other employees nine hours a day. The
engineers are not allowed to make any mechanical ad-
justments or repairs except in emergencies ; the machin-
ists do all such work. The same is true of all pipe fitting,
pipe covering, electrical work. etc. : a separate crew looks
after the street system. The company pays for tele-
phone- in the homes of all foremen of the crews.
January 5, 1915
P 0 W E R
11
Fig. 25. Turbo-Generator Plant at Sargent's Wharf
The turbine un the right made a nonstop run of IS months.
As all except heavy-machine and repair work is done
by the different gangs, it enables the company to main-
tain workmen who in time become trained in team work
and thoroughly familiar with the plant. These men do
excellent work, too, as is evidenced by even a casual
look around the engine room. The lagging, for example,
is exceptionally good. Much of the lagging that one
finds in plants is made of thin Russian iron, which, after
it has been taken off and put on a few times, would ex-
haust the patience of anyone to get on again. At the
Sargent's Wharf plant the iron for the lagging is in
heavy sheets and the reinforcing strips used are likewise
heavy.
Recokds
Seven different record forms, including a "summary,"
are made out daily in the engine room. In addition, there
are turned into the chief's office more than a score of
charts from recording instruments for various pur-
poses. All record sheets are of uniform size. Reports,
Fig. '?<;. Shkt,l-Type Ammonia Condensers
The condensers were built for 300 lb. pressure
Note the expansion corrugation that each has to allow for expansion
and contraction
12
PO w E i:
Vol. LI, No. ]
Pig. 27, giving maximum items and costs per units of
refrigeration, electricity, water evaporated, etc., are for-
warded to the general manager. Reporl sheets from the
engine and boiler rooms are bound in regular book form,
size 9^x8 in., shown, and filed in the chief's office; a
single volume contains one month's daily reports.
Lubricating Main Bearings
A bearing may be adjusted for running clearance —
i.e.. clearance enough to allow for smooth running with
the brasses and journal at normal temperatures — or it
may be given enough clearance so that should it become
hot from any cause the expansion of the brasses and
journal will not be sufficient to cause the bearing to
"freeze" or grip so tightly as to make it unlit for use
without much scraping. A- pounding frequently accom-
panies expansion-clearance adjustments, it is the usual
practice to adjust for running clearance. No trouble
is bad -I long as the lubricating oil is of proper quality
and is supplied iii s 1 1 1 1 i lie] 1 1 quantities and no Eoreign
matter gets into the bearing, but sometimes the system oil
"wears out" and trouble begins.
QUINCY MARKET COLO STORAGE AND WAREHOUSE COMPANY
EXPENSE REPORT
SARGENT'S WHARF POWER HOUSE
* 207.30
. .. 23.10
33.01
... U1.21
33.95
63. 9t
. iuu.9a
73.^3-.
* 3. 3*5. 51
359.53
3.021-72
all syatems t 119.72— lighting t 1.13 tooth
statlo
'>■"■'■■< s',... ♦ 570.10
>«5r ex, . OVtwk^t,'
DATA OF OPERATION
SARGENT'S WHARF POWER HOUSE.
Hunt at July. I9it,
REFRIGERATING eLANT
WAREHOUSE SYSTEM
BRINE
"*12 July lath,
323 ».. 5th.
11.001
.-.I, 111-..1 .3.196.800 ......... __■ 10th.
3.139.200 ■ 5M.
ro, m»ii> 98.156.100
DIRECT
STREET SYSTEM
622 -18th.
W9 ■ l»th.
16.822
1...01.. .. It. 086. 720 ... • 29th.
3. 695. 0>*0 M7th.
121,197.920
ELECTRIC 1'LANT.
17.*50 ■ 21ot.
12.075 • 31st..
ne.985
1.020 - 9 A.1U • 20th. .
t70 - 5 A.M. ■ i»th.
BOILER PLANT
COM.
'?:;;"""
3.129.200 It-
3.129.200
1561
156»
1 3.56
'•- 1200 .
1200
ASHES
,.„., ... „.»„.
205.950 „»
152
..... 1950
1.255.665
736.715
30.353-2'»0
July 18th.
•- . 26th.
Station unaerloaaea on account or cool weather.
V~ "\. -C ' (K^JsB-+^/kM
Pig. -.';. Some of the Report Fohms Used at Sargent's Wharf
lportant reports are made on sheets of uniform size ana monthly bound as shown by the los>- book at the
top of this illustrat
January 5, L915 TOW K II , 13
In many plants where oil is put through Biters, re- it, all the cylinders being supported by a sheet-tin parti-
turned to the system and used over and over again, fcion. Pig. ". i -hows how the cylinder is covered with
serious troubles sometimes arise due to hot bearings, flannel. The oil flows to the cylinder through %-in.
No good reason is evident; the oil is clean and supplied brass pipe, a swinging elbow and a nipple instead of a
in the usual or even greater quantities, yet nearly all valve being u ed to stop the oil flow to each of the six cyl-
the bearings are hot at the same time. Trouble of this inders in a filter.
nature frequently happens on a hot summer's day. The , „
',..•. . , ,. | . , , Ammonia Coxdexsers
reason usually lies in the facl that the system ml has
so weakened in viscosity and specific gravity that when an The present ammonia condensers are of the shell type.
extra warm day comes, with it- increase in load, if the Formerly cpen-coil condensers were used and located
plant supplies refrigeration it cannot furnish sufficient in the place now occupied by those of the shell type
lubrication; therefore all bearings with small running shown in Fig. 26. To insure a steady flow of water over
PRINCIPAL EQUIPMENT < >F SARGENT'S WHARF STATION, QUINCY MARKET. COLD STORAGE AND WAREHOUSE CO.
No. Equipment Kind Sile Dae Operating Conditions Maker
5 Boilers Watertubc Stoker fired, 140 lb. pres., 125 deg. F super-
"Stirling".. 350 hp -i an generation heat Rabcoek & Wilms Co.
5 Boilers Scotch 300 hp ion Hand fired, 140 lb. pres., 125 deg. F superheat A ilantic Works, Boston
5 Stokers Underfeed i Bituminous coal — New River, straight American Engineering Co.
1 Combustion
cont'lsystem Balanced draft All ten boilers Combustion control With forced-induced draft Blaisdell-Canady Co.
10 Superheaters Connected . . Superheated steam 140 lb. pres.. 125 deg. F. superheat Foster Engineering Co.
Economizers Tube Feedwater heating Intake225.li r5deg I Green Fuel Economizer Co.
10 Feedwater
regulators 2-in Feedwater flow regulation. . 140 lb. pressure. Boston Steam Specialty Co.
2 Injectors.... Double tube- Feedwater system-emer-
"BufTalo" . . 2J-in geney 140 lb. pressure, through economizer
1 Draft system Forced-induced. Boiler purposes Fan system, 4 in. in ashpits, 0.2 in ■
1 Feedwater
heater Closed Primary heating Inlet rX> deg. F. ; outlet 100 deg. F w ainwnght
2 Draft gages. "Steinbardt". Draft over fire — recording. . 0.2 to 0.4 in. connected to "Gaacomposmeter" Uheling Instrument Co.
1 Draftgage.. Indicating Draft over fire — indicating.. 0.2 to 0.4 in Uheling Instrument Co.
1 CO, re- "Gaseompos-
corder meter". CO, — recording Gas taken from main uptake Uheling Instrument Co.
2 Turbines Horizontal... 500 kw.. . Electric generator drive 140 lb. pres., 12"i deg. F. superheat, 1120
r.p.m., 28 in. vac Westinghouse Machine Co.
1 Turbine Horizontal . . 135 hp . . Pump drive 140 lb. pres., 1200 r.p.m. condensing Terry Steam Turbine Co.
1 Ammonia Angle-com-
compressor. pound 10(H) tons Refrigeration Providence Engineering W orks
1 Ammonia Angle-com-
compressor. pound 800 tons. . . Refrigeration Pennsylvania Iron Works
1 Ammonia Angle-eom-
compressor. pound. . . . 100 tons Refrigeration Pennsylvania Iron \\
1 Ammonia Pumping ammonia from sys-
compressor. Angle-single rem General pumping Frick Engineering Co
2 Brine pumps Cross-eompo'd. Each 10,000,1 00
pot type gal per day Brine circulation Street and warehouse systems Snow Steam Pump Works
1 Brinepump. Turbine sin ,., Emergency brine circulation Induction motor driven Worthington Steam Pump Co.
13 Ammonia
condensers. Shell type Ammonia gas condensation . SahVwatei connected The Bigelow Co
2 Pumps Volute m-in Salt water for all cooling. .. . Induction motor driven, 1 120 r.p.m Wheeler Condenser & Engineering Co.
1 Pump Volute . 14-in , . Sail water for all cooling. .. . Turbine driven. 1200 r.p.m Wheeler Condenser & Engineering Co.
1 Pump Triplex I2xl4-in Salt water for all cooling Engine driven Goulds Mfg. Co
1 Pump Duplex-com-
pound, plunger 6J, 10x6-in I .,,, Automatic control Snow Steam Pump Works
1 Pump Triplex..... 6xl0-in Feedwater system Automatic control, motor driven, continuously
operated Goulds Mfg. Co.
2 Pumps Reciprocating. 9, 22xl2-in.. , Air from surface condenser 28-hr. vac.; steam driven Wheeler Condenser & Engineering Co.
2 Condensers. Surface Central condensing system Dae water from ammonia condensers Wheeler Condenser & Engineering Co
2 Generators.. Turbo; alternat-
ing current. . 500 kn . Current fur station us,-. .. 3600 r.p.m., 440 voir-. . ■-,,;, :,-■. i.i; cycle Westinghouse Electric & Mfg. Co.
2 Generators.. Direct current in kw Station lighting 1125 r.p.m., 125 volts. SO amp . motor driven Westinghouse Electric & Mfg. Co.
1 Generator.. Direct current . . In l.u Station lighting 1125 r.p.m., 125 volts, 80 amp., engine driven. . Westinghouse Electric & Mfg Co
1 Motor Induction 15 hp D.c. generator 1120 r.p.m., 44n volt.-, 2-pha--. no cycle Westinghouse Electric & Mfg Co.
1 Motor Induction Son l.p Turbine brine pump 440 volts, 2-phase. 60 cycle Westinghouse Electric & Mfg. Co.
1 Motor Induction 20 hp Triplex feed pumps 1120 r.p.m., 440 volts, 2-phase, 60 cycle Westinghouse Electric & Mfg. Co.
2 Motors Induction 100 hp . Salt water pump 1120 r.p.m., 440 volts, 2-pha: Westinghouse Electric & Mfg. Co.
1 Switchboard Gray marble. Four-panel... Main electrical control ... Alternating and direct current Quincy Market C. S. &W. Co.
5 Engine stops Compressorsandbrinepumps Locke Regulator Co.
1 Engine Single acting. . . 2n hp . D.c. generator drive Station lighting Westinghouse Machine Co.
1 Air compres-
sor Single stage ... . Gxo-in General service Steam driven Inger-oll-Sargent Co.
1 Oil filter Centrifugal Waste oil Oil & Waste Saving Machinery Co.
1 Waste
washer. . . . Centrifugal Oil A' Waste Saving Machinery Co.
Note: The big steel lorgings for the 1000-ton i ompressor were made by the Bethlehem Steel Co.; the steel eastings, by the Chester Steel Casting Co.; the very
lings for the bed plate and A-frames bv the larr.ll Foundry and Machine Co.; the bronze castings by the Philadelphia Phosphor Bronze Smelting Co.; the
ind ammonia cylinders by the J. C. Colvin Co and the condensers and coolers by Tie- Bigelow Co., makers of the Hornsby-Bigelow boiler. All piping and
of the Quincy Market Cold make
clearances and those supporting heavy journals which them, the cooling water was pumped into a large tank
squeeze out the thin oil overheat. at the right of the room and elevated 20 ft. above the
System Oils Tested Duly condensers, the water gravitating to the latter. When
m ,. ,,.„«. >r,,^, the present condensers were installed this tank was not
lo prevent this trouble in the Quiiicv .Market Uo/s , , ■. , ,. , , , -. „„„„j on
, ' , . 1*1 needed, and as the discharge head was decreased i\)
plants the niLdit engineer tests a sample ol each system ,. . , , , , . . - .„„•+.,
',-■.. , ' . ; it., it helped to increase the pump s capacity.
oil each day lor the viscosity and specific gravity, the re- . ,, -, , . n ,, . , -, ;. e ,u
. J. ., . . „ ■ . ' , '.,,-,.• . ., . Another advantage following the introduction of the
port oroing to the chief engineer, who will direct that . „ . -, ,, , , , , ,
,.,'.,, ... . ° ., . , ., shell-tvpe condenser was that no water was splashed
lresh oil he added to increase these properties when the ,, a ,, T , , m, ■ • .
,,,.., ' ' over the floor, on the I-beams, etc this is more lavor-
reports show tins to he necessary. ,, ,, , - , , v . , -, , . ., , ,
1 able than one may at first believe, hut a look at the bal-
Oil FILTERS . ; , of the Richmond St. plant, where the structural work
The filters through which the oil finally passes on was very. seriously corroded in only seven years, convinces
its way to the engines were made in the plant. Briefly, one that the shell-type condenser is best for the condi-
their construction is this: A tank of oblong section has lions in these two plants.
six canton flannel-covered perforated cylinders set into The condensers are t ft. in diameter and contain 36"i
11
TOWER
Vol. 11. No. 1
one and one-half inch Shelby cold-drawn steel tubes, each
8 ft. long; the condensers were built for 300-lb. pres-
sure.
Notice the expansion corrugation in the condenser
shell. When the Quincy Market Co. first drew up its
specifications, this expansion corrugation was made of
heavier metal than the rest of the shell and riveted to it,
but experience shows that it is cheaper and better to make
the whole shell of the thickness of the corrugation.
An unmistakable error appeared in article III, p. 883.
'Plie word "more" in the next-to-the-last line should be
"less."'
Electroiramgfiiiefts for AMerirmftifij
C^rreimt CIfcujiMo
Bi Norman G. Meade
SYNOPSIS — Electromagnets in general and sam-
ple calculations for the design of a pair i small
magnets to operate on a 25-cycle circuit.
Alternating-current electromagnets differ from those
used on direct-current circuits, and the calculations for
the windings are essentially the same as for the primary
winding of a static transformer. The cores are laminated
and built up from soft iron or steel punchings, as in Fig.
1, which gives front and side views of a pair of tractive
magnets for general use such as actuating mechanisms,
lifting purposes, etc.
To secure economical design the electromagnet should
conform to established proportions. It is essential that
the magnetic circuit he complete and, where space will
not permit the use of two coils, the construction shown
in Fig. 2 may be used, the one coil serving to excite the
consequent pole.
Eor long-range magnets — that is, where the pull ex-
ceeds an inch or more in length — the plunger style of con-
struction, shown in Fig. ■'>. should he used. On single-
tlean length magnetic circuit
Fig. l. I'
Tiu<
Magnets
phase circuits, m- when connected to one phase id' a poly-
phase circuit, plunger magnets will make considerable
noise, owing to the oscillations of the plunger. This can
he relieved by placing a small compression spring between
Hie plunger and the stop, as shown.
For alarm hells operating From an alternating supply
circuit, the polarized electromagnet, shown in Fig. I. is
used. It has the distinctive advantage over direct-cur-
rent signaling magnets in that no make-and-break eon-
tacts are necessary. The coils are wound in a manner sim-
ilar to the direct-current magnets, hut the armature is
pivoted at the ceutei and is free to move in both direc-
tions. A permanent magnet is attached to the electro-
magnet yoke: having the form of an elongated U, the
lower end being just beneath the armature. When there
is no current passing through the coils the cores will
correspond in polarity to the permanent magnets as well
as tin1 armature, as indicated. When an alternating cur-
rent flows through the coils, it will tend to strengthen
one core and weaken the other at every alternation. The
armature will then be drawn up to the strongest core,
C om press ion Spring
/"
K
c
i i '
Fig. 2. Single-Coil
Electromagnet
Fig. •">. Tluxger
Type
causing it to give the striker two vibrations during each
cycle.
When the magnet coils are wound on metal spools, the
hitter should he splil from end to end, as in Fig. •">, to
prevent excessive loss due to eddy currents. Large coils
arc generally wound on forms and held in position on the
coles by small brackets.
Magnet 0 vlculations
The first essential in the design of an electromagnet is
to determine the pull. Assume that it is desired to con-
struct a pair of magnets, as in Fig. 1, which must have
a combined pull of 50 lb. through a %-in. air gap. The
pull in the air gap decreases as the square o( the distance,
so that the magnets will have to be designed for a combined
pull of 200 lb. for a total of one inch or !/2 i'1- on eacu
side. Assume a 25 cycle circuit and a core density of
30,000 lines of force to the square inch. The formulas
for determining pull and the transpositions for determin-
ing the Other factors .-ire as follows :
January 5, VJlo
r u W E B
p
A =
B* XA
72,134,000
7 2, 134,000 X P
/:-
IP X 72,134,000
where.
/> = r "* 1 1 1 1 in pounds :
Z? = Magnetic density per square inch;
A = Area of core in square inches.
Pecmanerrf
Magnet \
(==>
Pig. t. Polarized Elei teom ignet
The pull is divided between the two magnets and there-
in re will be 100 lb. in each.
The area of the core will be :
72,134,000 X 100
A =
= 8 sq.in. {approximately)
30,0002
To allow for some losses, it will be best to make the core
9 sq.in., or 3 in. square.
The number of turns required will depend on the mag-
netic flux N which threads through the turns, the max-
imum value being expressed as follows:
If = Bmax X A
where Bmax is the maximum value which the magnetic
Upojjek
Pig. 5. Split Spool to Prevent Eddy Currents
density reaches during a cycle, and .1 is the cross-sec-
tional area of the iron, in this case !) sq.in. Bence,
N = 30,000 X ^ = 270,000 lines.
Taking the induced electromotive force as equal and op
posite to the line voltage,
4.44 X N X TXn
where
N = Maximum value of the magnetic flux through
the core ;
T = Number of turns in the coil :
n = Frequency in cycles per second;
E = Impressed e.m.f.
Applying to the presenl example.
4.44 X 270,000 X T X 25
440 =
whence,
T
440 X lo8
= 1468
4.4 1 X 270,000 X 25
Assume the core to be 9 in. long and the width of half
the keeper and half the armature to equal •"> in. Also
-
-
/
/
4Q
=0
E
10s
" 0 50 100 150 200 250 300
Ampere -Turns per tnch of Length POW-,rc
Pig. 6. Ampere-Turns vs. Lines of Porce
let the distance from center to center of the cores be 1 1 in.
Then the length of one-half the magnetic circuit, or the
length per pole = '.» -4- 3 -f- :>y2 -4- 5y2 = 23 in.
From a permeability curve the permeability of soft
iron at a density of 30,000 lines per square inch is found
to be 1100 and that of air is always taken as one: there-
fore, it will require 1100 times as many ampere-turns per
inch oi length of the magnetic circuit for the air gap
From Fig. 6 it will be found that approximately 5.5
turns per inch of length of the magnetic circuit are re-
quired. Then the turns per coil for the iron will be 2:1 X
5.5 = 1261/^, and for each air gap of y» m-> 5.5 X 1 100
X 0.5 = 3025, and 3025 -f- 126 = 3151 ampere-turns
per spool.
As there are 14(18 turns per spool, the current will be
approximately two amperes. Allowing 2000 circ.mil> per
ampere, it will be found from a wire table that No. 14
B. & S. gage corresponds the nearest to the required size.
The table -hew- that No. 14 wire has 13 turns to the inch
16
P 0 \Y E 1!
Vol. 41. No. 1
and, allowing 8V2 in. as the length of the spool, the re-
sult is 13 X 8.5 or approximately 110.5 turns. Then
1468 -f- 110.5 = 13-j-, the number of layers.
SINGLE COTTON-COVERED MAGNET WIRE DATA
& S. Gage
4
5
6
7
Turns per Inch
4.5
5.09
:, 66
Layers per Inch
4.7s
5 82
R.41
7.3
tensio
130
■S 120
S
9
10
11
7 OS
7.fi6
S.54
9.7
S
8.42
g 6
li
§110
8I00
£ 90
34.4
36.9
40 . 38
14.6
From the table it will also be found that there are 15. 1
layers to the inch for No. 14 wire, so it will be necessary
to allow ]l/2 in- f°r the depth of the winding, including
the insulation between layers.
consists simply of a grooved brass wheel free to revolve
on a pin supported by a forged-iron holder. By moving
the lathe rest backward and forward the wire can be
wound evenly and quickly. It should be wound under
tension, which may be provided as shown in Fig. 10.
<o 50
7j> 60
I 50
y 40
t 30
c 10
E 0
1
1
^
y
<M
tr" '
IE
*
.<,Y
^
jy\
hO^r
1/
A
I
y
■r-
1 /
V
0 02 04 0.6 0.8 1.0 1.2 1.4 1.6 1.8 20 22 24 2.5
Watts Lo&t per Cubic Inch a Second. Soft Sheet Iron
Fii
Hystehbsis Curves
Practically all wire reels have a groove on one side which
will receive a wire to which a weight is attached, as shown.
The tension can be made as great or as little as desired
by varying the weight. If there is no groove in the reel,
a flat band of sheet iron or steel can be substituted.
-
Dorrel
Pins-:-.
b
t-
Hole for
Lead
--7-
Fig. 8.
Form fob Winding
Coils
Fig.
. <il"IDE FOE
VVlEE
Fig. 10. Method of Provid-
ing Peopbk Tension
As the spool is square in cross-section, this will give
each side a width of 3 in. or a perimeter of 13 in., and
the mean perimeter of the coil is 18 in.
1468 X 18 -=- 12 = 2202 ft.
is the length of wire per coil. The resistance of No.
14 wire is approximately 2.5 ohms per 1000 ft.: hence,
there is approximately 12 ohms resistance for the two
coils connected in series. Then the PR loss is 4 X 12 =
48 watts. The total core volume is 23 X 2 X 9 — 414
cu.in. From the hysteresis curves. Fig. 7, it will be seen
that for 25 cycles the loss per cubic inch is 0.1 watt, so
that the hysteresis loss will be 41.4, and the eddy current
loss may be estimated as 10 watts. Then the total loss in
watts will be 48 + 41.4 + 10 = 99.4 watts. The out-
side surface of the coils is 4 X 6 X 8.5 = 200 sq.in. per
coil. As at least one square inch of coil surface must be
allowed for each watt lost, it will be seen that the figures
are well within the safe limit.
For winding spool magnets, small hand-driven ma-
chines can be purchased at low cost, but a lathe is more
satisfactory. Fig. 8 shows a simple form for winding
roils which have no spools. It consists of a wooden
spindle and end turned from one piece and mounted on a
steel arbor. It is secured by a flange attached to the arbor
with a pin or setscrew. One end of the spool is remov-
able and is held in place by a nut and dowel pins.
A guide for the wire is shown in Pig. 9, which is in-
tended to be clamped in the tool post of the lathe. It
To secure the lasl turn of wire on the coil in position,
a piece of webbing in the form of a loop is laid under the
last five or six convolutions and the wire end is passed
through it, after which it is drawn up tight. The coil
is then slipped oil' the spool or form and given a wrap-
ping of tape or webbing, after which it should be given
a thorough coat of insulating paint. It i- generally pref-
erable to solder a piece of flexible conductor to the wire
l lids inside the coil.
Nipples — A nipple is a fitting made from tubular goods,
and usually threaded on both ends. It is under 12 in. in
length. Pipe over that length is referred to as cut pipe.
A close nipple has no shoulder and is about twice the
length of a standard pipe thread.
A shoulder nipple has any length. It derives its name
from the shoulder of pipe left between the two threads. A
shoulder nipple is intermediate in length between a close
and a short nipple.
A short nipple is slightly longer than the lengths of the
two threads, being a trifle longer than a close nipple. Some
unthreaded shoulder exists between the two threads.
A space nipple contains a shoulder between the two
threads, and may be of any length allowing a shoulder.
A sub-nipple is a substitute nipple, or, in other words,
a short pipe with different styles of thread on its ends.
A swage nipple is a reducing nipple, having one end
smaller than the other.
A long screw nipple is made up of a short length of pipe;
one end has a standard thread, the other is threaded far
enough to allow a coupling and lock-nut to be turned by
hand without overlapping the pipe end. It is an advai
when making a connection, or for connecting pipes in place.
January 5, L9 I -">
I'o W K R
Go^l-WeM^^E ILarries
17
The Cleve-
land municipal
electric-1 ight
plant uses two
B rownhoist
coal - weighing
bin to tin- StOK-
ers and weigh
each loarl I Pig.
1). The plant
is e (i u I P P e a
iged
hoppers, eacn
lit ted with a
Bir nwnhoist
air- operated
sate, and each
separately con-
illed b:
in
air valve lo-
cated along the
crane runway
within reach of
the larry oper-
ator when the
larry is stopped
beneath t li e
gate. The air
c y 1 i n il e r is
s w i v e led so
that it will ad-
just itself to
the different
positions of the
piston w h i 1 e
the gate is
in the act of
opening a n d
closing.
Each larry
operates with a
transfer crane
which travels
along a run-
way beneath
two rows of
the gates. The
larries reach
the other two
rows of gates
by individual
tracks. The
transfer crane
P <
■at.
from the larry.
T h e operator
brings the
transfer crane
into alignment
with the tracks
running to the
stokers or to
the farthest
coal gates and
the larry runs
off the crane
onto these
tracks after a
locking device
is set to keep
the crane in
alignment with
the tracks. Fig.
2 shows the
larry deliver-
ing coal to the stokers. Bach electrically operated larry
of two-ton capacity. Two gates are provided through wh
the coal flows onto a belt which throws it into the hoppers
The larries and cranes are equipped with brakes, and ar
is open ends on the tracks are provided with safety stops
h prevent the larries running off. Bach larry is equipped w
scales, with the scale beam in the operator's cab. The op
ator keeps a record of all coal delivered to the stokers.
IS
P 0 W L B
Vol. 41, No. 1
Tfee Wages ©f JEEagpsaeeffS
Bv Eael Pagett
Much has been written aboui the compensation received
by engineers. As data on the salary drawn by engineers
are noticeably lacking, the writer set out to collect the
facts from the men themselves by a letter sent to engi-
neers in widely separated sections of the United States.
(if the seventy-five letters -cut out. many came back and a
number were not answered. It is regrettable that a
greater number of places could not be heard from.
The following table shows the data as collected :
: No. of Men Hr. i>er Salary per Week
Place Plant, Hp Chief Ass'l Week Chief Ass'l
Cambridge. Mass 25,000 1 4 56 $45.00 K
««) 1 3 56 4ii 00 25 i»>
ii k i 1 3 56 35.00 25.00
(00 1 3 56 31-25 18.00
500 1 1 60 35.00 23 00
Chief Ass't
Baltimore, Md 1.000 1 1 66 25 00 17 50
600 1 2 54 72 30 75 17.50
400 1 1 66 78 25 00 19 50
400 1 2 54 72 25 00 17. .50
800 1 2 54 72 25 00 18.25
Hvattsville. Md 700 1 3 56 56 34 60 23 00
700 1 ■ 3 56 56 38.45 21 00
450 1 2 56 56 30.75 20.75
lOOf. oill 0 56 72 23 00
100 1 0 70 S4 23.00
Salary
per Month
Clay Center. Ohio 5.000 1 2 70 84 $125 $85
not stated 1 1 S4 84 100 96
700 1 1 84 84 75 70
Laramie. Wvo 700 1 4 70 70 100 95
Lishon, Ohio 12.000 1 3 56 56 100 80
1,000 1 3 56 56 110 80
10,000 1 3 56 56 125 90
6,000 1 2 84 84 90 80
Louisville, Ky 15,000 1 2 84 84 160 125
1.200 1 3 48 48 150 78
300 1 3 56 56 100 90
300 1 1 60 60 10S 78
100 1 1 72 72 108 65
Exeter. Neb 225 1 1 54 54 90 70
250 1 1 54 54 100 70
The standard rate for the mining districts of the South-
west does not vary greatly over a wide range of plant size.
Chief engineers get from $150 to $200 a month, some-
times including house, light and water. Watch engi-
neers receive from $125 to $150 a month; eight hours is
considered a watch and thirty and thirty-one days a
month. No reports on special plants were received.
Memphis, Tenn. : No report on special plants. The
correspondent states that chief engineers average about
$125 and assistants about $75 a month.
Foxboro. Mass. : The wages in this vicinity will av-
erage as follows :
Per Week
First-class engineers S23 to $30
Second-class engineers IS to 23
Third-class engineers 15 to 21
Firemen 14 to 17
Hours worked will average 55 to 6G
Framingham, Mass.: In plants of from 1000 to 5000
kw. three or four men are employed, winking in eight-
hour shifts, the chief sometimes standing a watch. Chief
engineers receive from $25 to $35 per week and assist-
ants from $18 to $25 per week.
In manufacturing plants of from 1000 to 2000 hp.,
usually one chief and three operating men are employed
in eight-hour shifts. The chiefs get about $30 per week
and the assistants from $18 to $24.
In smaller manufacturing plants of from 100 to 500
hp., one engineer and a day and a night fireman are
employed. The engineer works fit) hours per week, spends
from two to five hours at the plant on Sundays, and re-
ceives from $18 to $26 per week. Plants smaller than
this pay from $15 to $18 per week of about 60 hours.
Large brewery plants in this vicinity pay about $35
per week for the chief engineer and $21 to $25 for the as-
sistants; engineers work in eight-hour shifts.
South Chicago, 111.: Information on one plant only.
The men work six 12-hour shifts and change every week.
First assistants get $1 per day, second assistants $3.50
and third. $3: oilers and stokers, $2.50 per day; chief
engineer's salary not given.
Norman, Okla. : Plant of 250 hp.. one day and one
night engineer; 84 hours per week with $100 and $80
per month respectively. Pumping plant, one engineer
at $1200 per year. Plant with three boilers and one
125-kw. generating set: one chief and two assistants on
eight-hour shifts : chief receives $1000 a year, assistants
$70 to $75 a month. Plant of 150 hp. : one chief, who is
also superintendent of machinery, at $1200 per year.
New Orleans. La.: Chief engineers of ice and cold-
storage plant.-. $100 to $200 per month, subject to call at
any hour; assistants, $75 to $85 a month, 84 hours a week.
No report on other plants.
Wichita, Kan.: Only one plant reported: 8750-kw. ;
one chief engineer and three assistants, each working 56
hours per week. The chief gets $125 a month and the
assistant- $" 5.
Coffevville. Kan.: Plant of 900 kw., one chief engi-
neer and two assistants on eight-hour shifts. The chief
gets $100, assistants $75 per month. Plant of 400 kw. :
one chief engineer, three assistants on nine-hour shifts.
The chief gets $150 and the assistants $75 per month.
Plant of TOO hp. ; one chief working 70 to 77 hours per
week at $95 a month. Plant of 150 hp. ; one day and one
night engineer on 12-hour shifts: day man gets $3 and
the night man $2.50 per day. The day man washes the
boilers on Sundays. Plant of 300 hp. : one day engi-
neer, working 84 hours a week at $100 a month. The
watchman cares for the plant at night.
There seems to be a wide variation in the wage- paid
in similar plants. Take the plant of 600 hp. in the
vicinity of Cambridge. Mass. : it pays the chief engineer
$160 a month, working 56 hours a week, while in the
vicinity of Clay Center. Ohio, a plant of 500 kw. pays the
chief engineer $75 a month for S4 hours a week.
It would seem that if it is worth $160 a month to run a
plant in one place, it should be worth at least that much
to run a similar plant almost any place.
The Watson-Stillman Co.. 50 Church St.. New York
City, has added to its line a new type of motor-driven
Tkiplex Hydraulic Pump. Motoi; Driven
geared, triplex, single-acting pump. While primarily de-
signed to meet the severe demands of tunnel service, it
will be equally suitable for other conditions.
January 5, l'J15
POWE K
1M
To secure compactness, rigidity and alignment of the
working parts when under severe service, the motor is
mounted on an extension of the heavy cast-iron base.
The driving shaft and bearings are large and are provided
with lubricating cups. The gears are of the heavy cut-
tooth type. The drive from the shaft is by eccentrics set
at 120 deg. cast in one piece and keyed with one key
to the driving shaft. The eccentric straps are heavy.
The plungers are of tool steel and are guided in a cross-
head guide which is keyed and bolted to the base.
The pump body is a steel forging lifted with bronze
valves and bonnets. All passageways are made large to
reduce the friction id' the water to a minimum. The pump,
shown herewith, is operated by a 10-hp. motor running at
500 r.p.m., and delivers 100 cu.in. of water per minute at
3500 lb. pressure, with a crankshaft speed of LOO r.p.m.
Other sizes of the pump are built to suit operating condi-
tions.
flE&s&avIlla{ta©!r& as.E&dl Car© of Fis°e=
ta©Ea
By J. (). Benefiel
Usually, such apparatus is installed under the super-
vision of an insurance company, but it often happens
that additional buildings are erected requiring automatic
sprinklers, and the engineer should be able to plan and
supervise the extensions satisfactorily, thus saving his em-
ployers considerable expense.
One thing he should avoid is getting too many sprink-
lers on one branch line. The distance from the wall to
the first sprinkler should not be more than half the dis-
tance between sprinklers in the same direction. Under
a pitch roof one line of sprinklers should be in the peak.
Splash plates should not be less than three nor more than
ten inches from joists or ceilings. All stairways, closets
and odd corners should be looked after.
LOCATION AND SPACING OF SPRINKLERS (FROM THE RULES AND
REGULATIONS OF THE ASSOCIATED FACTORY MUTUAL
INSURANCE CO.)
One Row of Automatics Water Pressure at Highest Sprinkler
Placed Midway Exceeding 20 Lb. Less Than 20 Lb.
between Beams Medium Special Medium Special
in Each Bay Hazard Hazard Hazard Hazard
In 12-ft. bays Sprinklers: 8 ft. apart 7 ft. apart 7 ft. apart 6 ft. apart
In 11-ft. bays Sprinkler*: !l S S 7
In 10-ft. bays 8prinklers:10 0 9 8
In 9-ft. bavs Sprinklers:ll 10 10 0
In 8-ft. bays Sprinklers:12 11 11 10
In 7-ft. bavs Sprinklers :12 11 11 10
In 6-ft. bays Sprinklers :12 11 11 10
The terms "medium" and "special hazard," in tin.'
table, relate to the contents or occupancy of each room.
Especially hazardous places are picker rooms, sawing de-
partments of wood-working plants and varnish rooms.
The following tabulation gives the maximum number
of sprinklers to be supplied by the sizes of pipe given:
Size of Pipe, In. No. of Sprinklers Size of Pipe, In. No. of Sprinklers
Supporting the branch pipes by hangers in rooms where
there is much heat or steam is a serious problem. An-
other annoyance is leakage around the valve stems.
The swing checks on the inlet from city mains and-
the discharge from the fire pump sometimes stick open
when the spindle on which the check swings is iron and
corrodes. All moving valve parts should be made of brass.
In rooms where certain processes are carried on. the
sprinklers should be taken off and cleaned whenever they
become coated with deposits.
During the regular overhauling in a certain plant the
disks of the 2-in. drain valves are taken out, cleaned, and
a ring of gasket rubber is put on the disk to prevent a
leakage which would cause a loss of the water seal on top
of the dry valve.
To those not acquainted with the valves it is explained
that the upper (sprinkler) side of these valves has about
live times the area exposed to the air pressure to hold it
shut to one mi the lower side subjected to water pressure.
About 35 lb. of air is usually carried to balance 100 lb.
water pressure. When a sprinkler bead acts, the air pres-
sure is reduced and the water-supply valve opens. The
system then lills with water. After being in action it is
necessary to again put the system in order. All the
._
Frost-proof box or room
lent Test Valve -ij
Ground Level
"~~
From Dry
Valve
3t
FIG 2
Drain
-iia
To Sprinklers
'-Low Point
''Drain
Unueeukounh Section- of Line
drains are opened to let the water out to the test valve
above the tee shown, Fig. 1.
All the drains are then closed and from forty to fifty
pounds of air pressure is put on the system. One man
goes around opening the drains, one at a time, untii they
show no water. The air pressure is then brought up to
about thirty-five pounds and the valve in the yard is
opened to let the water pressure against the under side
of the dry valve. The drains should be opened about
twice a week for two or three weeks to make sure the sys-
tem is free of water.
If the building is warm during the day and cold at
nights and on Sunday, an allowance must be made for a
Loss of pressure <iw to the air contracting in the pipes.
Fig. 2 shows a drop underground to another building.
The draining of the underground section was a problem,
there being no sewer. It was done by bringing the drain
to the surface, as shown, and blowing the water out b\
air. It has worked successfully for years and has but
one drawback— so much talking must be done to convince
each new inspector that it works.
30
P 0 \Y E II
Vol. II. No. l
r-Plant Apparatus
Fig. 1 shows a Wellman-Seaver-Morgan Co. duplex motor-generator flywheel set consisting of a 3!i0-hp. motor driving
one 400-kw. and one 200-kw. direct-current, 550-volt generator running at 720 r .p.m. At one end of the shaft there is
attached a direct-current exciting unit. The flywheel weighs 25,000 11>.
This machine, which is used by the Cleveland Cliffs Iron Co., acts as a balancing set and furnishes direct-current to
a main ore hoist and to a man-and-timber hoist. Fig. 3 is a geared hoist with a single drum for hoisting men and timber
in a single 1300-ft. compartment shaft, the counterbalance being obtained by the use of counterweights. The machine
is geared to produce a hoisting speed of 1000 ft. per min.
The drum is 98 in. diameter by S4 in. face, and is grooved for a 1% -in. rope. A 96-in. diameter band brake is on our
end of the drum. The double-acting brake is applied by gravity and is released by means of a combined air and cataract
cylinder. The gears are of the herringbone or helical type. The electrical equipment consists of a 500-volt, 200-hp. direct-
current motor running at 2T.0 r.p.m. and receiving its current from the duplex motor-generator set, Fig. 1.
Fig. 2 is a large jet condenser with a small jet condenser in the foreground. The large unit is in use at the West-
port plant of the Consolidated Gas, Electric Light & Power Co., Baltimore, lid., with a 15,000-kw. turbo-generator. This
condenser takes care of 200,000 lb. of steam per hour to a 281,£-in. vacuum with TO deg. F. injection water.
The small condenser shown is used with turbines up to 300 kw. capacity. This particular unit takes care of a low-
pressure turbine of 100 kw. capacity.
In both condensers the same general idea is worked out; viz., the air- and water-removal pumps being on the one
shaft, either turbine or motor driven, the removal pump being submerged in the tank base of the condenser. Both units
have substantially the same water distribution and are of the parallel-flow design.
Fig. 4 is a 12,000-amp., fiOO-volt circuit-breaker, the largest capacity alternating-current circuit-breaker in the world.
It is in the Wood Worsted Mills, Lawrence, Mass., the largest worsted mills known.
Fig. 5 illustrates a 40,000-amp., motor-operated switch for electric furnace. The output of the furnace is either 20,
amp with a potential of 40 volts, or 40,000 amp. with a potential of 2" volts. The weight of the switch is 7193'- lb In
the construction of this switch 52fis lb. of copper was used, over 2'- tons; S71 lb. of composition metal; 6S1 lb. of cast iron:
342 lb. of steel and 31% lb. of mica. This switch was manufactured by the General Electric Co., Schenectady. N. V. as
was the 600-volt circuit-breaker.
January 5, 1915
P O W E R
21
Editorials
siiiiiiiiiii'iiiiiiiiiiiiii iiiiiiiiiiniiniiiiiii n""';'' ii nimiiniiii niiin;i niiiniiiiiiiiiiiiiniiniininiiiiiiiiiiiii'iiiiiii'iniii n mil i
Akerlund down-draft, produc er capable of gasifying either
soft coal or mesquite wood.
The Alabama Power Co. has recently installed the first
of four 17,500-hp. generating units at its hydro-electric
static n the Coosa River. The turbine is the largesl of
the single-runner type in operation. To the Brooklyn
Edison must be credited the largest single-cylinder steam
turbine. It is rated at 22,000 kw. and with a moderate
temperature rise il is expected to carry 25,000 kw.
Recently the first ear containing parts of the mammoth
direct-current generators tor the Ford plant in Detroit
left the works of the Crocker-Wheeler Co. Each of the
four machines is to have a normal capacity of 3750 kw.
and will weigh 105 tons. The field frame is 21 i't. high
and 26 ft. wide across the supporting feet. The armature
is 16 ft. in diameter and weighs 87,000 lb. As this dimen-
sion exceeded the limits for track clearance the assembling
of the armature parts and the winding must he done in
Detroit.
Another event worth noting in the electrical -field is
the completion of the longest transmission line by the
Southern Sierras Power Co. It extends 400 miles from
the generating station to the most distant, customer, but
the main straight-away transmission is not as long as
that of the Big Creek system.
Credit for the largest Diesel engine built in this country
to date belongs to the Lyons Atlas Co., Indianapolis. It
has four 21x30-in. cylinders, which will develop normally
600 hp. and a maximum of 690 hp. driving a two-stage
turbine pump of 15 million gal. capacity against a head of
200 ft. The unit will be used by the Hawaiian Commer-
cial & Sugar Co. for irrigation purposes.
Valves for steam headers which weigh 3600 and 3900
lh., respectively, are not common. In fact, the Nelson
valves of the above weights recently furnished the New
York Edison Co. are claimed to be the largest steel gate
valves for superheated steam yet installed. When open
(hey measure 9 ft. 1 in. from the bottom of the body to
the top of the stem. The valves are to be mounted in
18-in. steam leads, carrying steam under 200 lb. pressure
and 150 deg. superheat.
Steam Turbines
Of the various large turbines building for Chicago.
New York, Philadelphia and elsewhere, perhaps the most
interesting is the 35,000-kw. unit for the Philadelphia
Electric Co., as it is the largest in the world by 5000
kw. The prime mover is a thirteen-stage horizontal Cur-
tis turbine 63 ft. 2 in. long over all, 21 ft. 7 in. wide and
15 i't. 10 in. high. The weight of the unit is 600 tons.
It will receive steam at 215 lb. pressure and 150 deg.
superheat and exhaust against, an absolute pressure of 1.5
in. of mercury. At. the most economical load, 25,000
kw., it is expected to develop a kilowatt-hour on 11.9
lh. of steam. At the full rated load of 35,000 kw. the
water rate increases to 12.6 lb. per unit. With a better
vacuum the steam consumption will be lowered slightly.
The condenser for this immense unit is naturally the
largest in the field. It is of the center-flow surface type
l\[ 1913 the word "'large'" best defined the tendencies
of development, and the impetus gained in this period has
carried over into the year just past. Notwithstanding the
genera] depression in business, installations were made in
which some of the equipment holds first place in size Or
capacity. Long ago the advantages of concentration were
appreciated and the constantly growing demands have
urged the manufacturer to greater efforts. Each year
something bigger than ever he fore makes its appearance
and apparently only raises the horizon for the particular
field concerned.
In looking over the tiles for the year the first large.
device to attract attention is a Mesta triple staggered-
tooth spur gear, 22 ft. 8 in. in diameter, having a 38-in.
face and 154 teeth spaced on 5^-in. circular pitch. It
was built to drive a sheet mill of the Inland Steel Co.,
and at a speed of 2000 i't. per min. the gear transmits
1600 hp.
For the Woodward Iron Co. two horizontal cross-com-
pound Mesta blowing engines, -18 and 8-1 by 60 in., were
installed. A notable feature was the building of one en-
gine in 38 days and the completion of both in 59 days.
The Nichols Copper Co., Long Island City, has the largest
Keeler water-tube boiler ever built. The boiler is rated
at 1280 hp. and has a little more than half the capacity
of the Stirling boilers now being installed at the new Con-
nors Creek station of the Detroit Edison. It will be re-
membered that, these boilers are rated at 2350 boiler-horse-
power, and by forcing are capable of carrying continu-
ously the enormous load of 13,300 kw. Normally, they are
designed to care for 10,000 kw.
In cooling towers there have been three large installa-
tions: one a twin Wheeler-Barnard forced-draft tower for
the American Hardware Co., New Britain, Conn., capable
of cooling 132,000 gal. of water per hour from 100 to 80
deg. F. ; a battery of towers of the same type to cool 600,-
000 gal. of water per hour for the Texas Power Co.,
Waco, and a Mitchell-Tapperj atmospheric tower capable
of cooling 120,000 gal. per hour through the range pre-
viously given. The tower last mentioned was installed for
the main power house of the South West Missouri Bail-
road Co., at Webb City, Mo.
A notable pump installation was made for the Plaque-
mine & Jefferson Drainage District of Louisiana, con-
sisting of four 76-in. and one 48-in. centrifugal pumps
built by the Southward Foundry & Machine Co. The
larger pumps each have a capacity of 168,000 gal. per
miii. (over 10,000,000 gal. per hr.), at 1 -it. head and 40,-
000 gal. per min. against a head of 13 ft., and are used
to pump water back over the levee into the Mississippi
River. The 100-million gal. De Laval centrifugal pump
recently installed at Pittsburgh has a 18-in. outlet, but
it must raise the water against a total head of 56 i't. An-
other interesting installation is the first large American-
built Humphrey gas pump which is to be used for irriga-
tion purposes near Del Rio, Texas. The cylinder is 66
in. in diameter and is supplied with gas by a 300-hp.
P 0 W E E
Vol. 41. No. 1
containing 50.000 sq.ft. of surface in 1-in. tubes. This
reduces to 1.43 sq.ft. per kilowatt of turbine rating, which
may be compared to an average of 3 sq.ft. a few years
ago. That injection water is supplied through a 48-in.
pipe will give some indication of the quantity required.
The auxiliaries are all turbine-driven centrifugal units,
and the air pumps are the Le Blanc type. The generator
delivers three-phase 60-cycle currents at 13.200 volts. The
speed is 1200 r.p.m. The station is to contain also a
30,000-kw. unit of the same type which will deliver 25-
eycle current with the same expenditure of steam at the
most economical load. 22,500 kw. The speed will be 1500
r.p.m.
When the above water rate is compared to the guarantee
for the 25.000-kw. Parsons turbine at Fisk Station, of
11.25 lb. per kv.-hr. against a back pressure of 1 in. of
mercury, it will be seen that there is little if any difference
in economy between the two machines. It may be of in-
terest to state that this English unit is now in satisfac-
tory operation. The troubles usually encountered when
starting a machine of a type new to the station, and other
troubles due to damaged insulation, have been overcome.
As previously stated in these columns, this unit is of
the two-cylinder tandem type: the Brooklyn Gold St. tur-
bine has but a single cylinder, while the 30,000-kw. In-
terborough turbines have two cylinders arranged cross-
compound and operating at different speeds. Several ad-
vantages are claimed for the compound units such as a
smaller temperature range in each cylinder, the possibility
of separating the moisture midway in the expansion of
the steam, smaller cylinder structure and the reducti I
stress set up by wide temperature ranges. In the single-
cylinder turbine this is offset by a machine which takes
about three-fifths the floor space occupied by the tandem
compound and a still lower fraction of the space taken by
the cross-compound. The water rates do not vary ap-
preciably. The action of the Brooklyn turbine in practice
will no doubt help to determine the limits of a single cyl-
inder.
In this same turbine the stationary blading for the
high- and intermediate-pressure sections is not fastened
to the casing but is mounted mi cylinders set into it. This
practice is being followed in other large turbines as it
has been found desirable from the standpoint of conven-
ience and strength. An increase in the speed of these large
units is also a point of interest. The earlier of the large
turbines were designed for 750 r.p.m.; the Brooklyn unit
makes 1500 turns per minute, and some 20,000-kv.-a. tur-
bines now being built for the Public Service Corporation
of New Jersey are to run at 1800 r.p.m.
A serious difficulty tending to limit the capacity of
these great machines is the problem of utilizing effectively
the immense volumes of steam in the lower stages. The
struggle io obtain greater peripheral veloi ity for the final
stages ami greater si cl ion through them so as to maintain
the most efficient ratio between -team and blade velocity
has resulted in a number el' suggestions such as a con-
siderable increase in the diameter of the final elements, a
combination of velocity, pressure-impulse and reaction
stages and other arrangements tending toward the same
end, as discussed quite recently in these pages.
Engine Progress
For several years the tendency has been toward higheT
speeds and consequently engines ol less weight which re-
quire less excavation and concrete and give more room
for purposes other than jiower generation. By the use of
higher pressures and some superheat, water rates have
been lowered, although the longevity and low upkeep of
the Corliss have been sacrificed to some extent. The re-
duction in initial cylinder condensation by the adoption
of the una-flow principle has boosted the economy of con-
densing engines. With pressures ranging from 300 to 500
lb. there are greai possibilities for the above type. Already
results obtained from one cylinder equal those from the
average compound, anil the ultimate goal is an economy
approaching that ol' the Diesel engine.
In tin- connection it may lie of interest to state that
the year has seen the first una-tlow engine built in Amer-
ica under the patents of Professor Stumpf and the per-
sonal supervision of his representative. A 15xl6-in. en-
gine designed to carry 100 kw. and running at 250 r.p.m.
under a steam pressure of 1 15 lb., a superheat of 88 deg.
and a vacuum of 25i.> in. developed an indicated horse-
power-hour on 12.5 Hi. of steam. The lowest nonconder,-
sing rate with steam superheated 130 dee-, was 1G.8 lb.
and with saturated steam, 20.4 lb. Tt is evident that the
una-tlow is primarily intended to operate condensing.
Another design of una-tlow engine has been perfected by
the skinner Engine Co. with practically the same non-
condensing steam rates, and the Nordberg Co. has pro-
duced a una-tlow engine with poppet valves to supersede.
for high pressures and superheats, its previous design em-
ploying Corliss valves. The same company has also im-
proved it- poppet-valve engine by locating the valve seats
in the heads and operating the valves mechanically instead
of depending on a spring for the return movement.
The first Buckeye-mobile in commercial service is a
feature of the year. This particular unit is rated at 115
hp. and is directly coupled to a 75-kw. alternator at the
veil,- of the International Cork Co., Greenpoint, L. T. 1;
occupies a floor space IT ft. 10 in. long by 7 ft. <> in. wide.
From the base to the top of the flywheels the unit stands
!> ft. high. In its shop test the engine, which is com-
pounded, developed a steam rate of 13.3 lb. per i.hp.-hr. on
1.33 lb. of coal. The boiler pressure was 210 lb. and the
superheat 171 deg.
Boilers
The practice of forcing boilers for the peal; load to
double and. in some cases, triple their rating is becom-
ing more firmly established. Where formerly it was cus-
tomary to provide a boiler-horsepower for every kilowatt
of generating capacity, a ratio of 1 to I is now common in
the larger station-. Lower water rates, of course, help in
this direction. In the new generating plant of the United
Electric Light & Power Co.. of New York, commonly
known as the 201st St. Station, which was officially pi:;
in commission on dan. 31. one boiler-horsepower is ex-
ported to care for 1.1 kw. At Waterside Mo. 2. the ratio
of boiler-horsepower actually used to installed generator
capacity is 1 to 4.2 and in emergencies at Delray one
boiler-horsepower will supplj 5.65 kw. This necessitates
a more extended use of forced draft, although in Boston
a natural-draft plant with some cheap means, such as
steam jets. of materially increasing the draft during peak
loads, is considered the ideal installation.
The amount above normal rating at which a boiler can
be safeh operated depends largely upon the scale-form-
ing and suspended matter in the feed-water. In quite a
January 5, 1915
pow E i:
2:;
number of the larger stations where boilers arc forced to
(several times their ratings, the use of distilled water is
being considered. The cost would not be great, as the
make-up in a "tight" plant is only a small percentage of
the feed. Some doubts as to the corrosive effect of dis-
tilled water are prevalent, but its use For years in marine
plants has failed to reveal any serious trouble.
A startling suggestion brought forward this year by
W. L. R. Emmet, of the General Electric Co., is the use
of mercury as a working fluid for heat engines. The proj-
ecl has taken more definite form than a mere proposal,
as experimental work has been conducted for some time
and the installation of a 100-hp. unit at Schenectady was
completed some nine months ago. A mercury boiler sup-
plies vapor to a turbine. The latter exhausts to a con-
densing boiler which generates steam for another turbine
on the same shaft. The mercury is. of course, returned
to its respective boiler. The advantage of using mercury
lies in its ability to utilize much higher temperatures
without excessive pressures. At atmospheric pressure
mercury boils at •',;; deg. E. and condenses in a 28-in.
vacuum at 455 deg. The density of its vapor is another
advantage permitting in a turbine the use of much shorter
blading in the low-pressure stages. Comparing the system
to the ordinary steam plant, Mr. Emmet estimates a gain
of (Ki per cent, in delivered power at an additional fuel
expenditure of 15 per cent. About $10 worth of this new
medium will be needed per kilowatt of mercury turbine.
In Europe, high-voltage, alternating-current electric
boilers have been in use for a number of years. These
boilers take the primary current and may he used to gen-
erate steam for heating or commercial purposes, to keep
the water hot in boilers of a steam reserve plant or to
maintain reserve water units in operation, which ma\ he
switched into service on the line at a moment's notice.
The first plant on this side of the Atlantic was installed
this year in eastern Canada. It consists of two single
units of 750 kw. each, operating on 2400-volt, three-phase
current to generate steam of 125 lb. pressure for heating
a cotton mill during night hours. It is estimated that one
kilowatt-hour will produce about three pounds of sat-
urated steam at pressures up to 125 lb.
A new sectional water-tube boiler in which one large
circulating pipe conveys all of the water from each drum
to the bottom of the header sections has been perfected
by A. Venning. Preston. Out. T. T. Parker, New York,
has patented a cross-drum water-tube boiler with several
novel features, and quite recently the possibilities of the
high-pressure Winslow boiler have been brought to the at-
tention ol' tin' engineering fraternity.
In locomotive practice in the past year the Crawford
stoker has shown wonderful possibilities for heavy freight
and transfer as well as fast passenger service. Rates of
combustion as high as 200 lb. of coal per square foot of
grate per hour have been obtained.
Marine Tendencies
Relative to development in the marine field the Talbot
and the Niclausse boilers have been improved with a view
to bettering the circulation and as a natural consequence
the efficiency. The new Ward wrought-steel, water-tube
boiler for marine purposes is also a product of the year.
On Eeb. 26 the "Britannic" was launched. In spite
of the war. the White Star Line expects to put this 50,000-
ton liner in service in 1915. She is 900 ft. long, which
may be compared to 882 ft. 9 in. for her predecessor, the
"Olympic." The extreme breadth is 9t ft. and the dis-
placement at a load draft of 34 ft. 7 in. is 53,000 tons.
The displacement of the "Olympic" when drawing •"> I ft.
6 in. is 3000 tons less. Chief interest centers in her ma-
chinery. Three-screw propulsion is effected by four-cyl-
inder, triple-expansion engines, 51, SI, 97 and 97 by 75
in., on the wing screws and a low-pressure turbine on the
center screw. The latter will receive steam at about nine
pounds absolute pressure and exhaust into condensers at
one pound absolute. At 165 r.p.m. the turbine will de-
velop more than in.OOO hp. The great advantage of such
equipment is that the machinery can be worked at reduced
power with practically the same efficiency as at full load.
The annual report of Lloyd's Register, recently issued
for the year ending June 30, 1914, calls attention to the
increasing use of steam turbines, and especially those
which are geared to the propeller. At present there are
23 vessels now being built under Lloyd's classification in
which geared turbines are to be fitted, six vessels which
will use direct turbine drive and six which will have the
three-screw combination installed in the "Britannic."
Employing the reduction gear allows both turbine and
propeller to be driven at speeds most efficient for each.
The U. S. Collier "Neptune" has shown the adaptability
of reduction gears, and with the higher turbine and lower
propeller speeds suggested by the original trials, good re-
sults are expected.
Tn the TJ. S. Collier "Jupiter" electric drive was in-
stalled. In the year and a half in which she has been
in commmission she has steamed about 14,000 miles and
has been thoroughly tested under all conditions of ser-
vice. The speed of the nine-stage Curtis turbine is 1990
r.p.m. and of the two induction motors driving the propel-
lers, 110 r.p.m. In showing an economy from 20 to 25
per cent, greater than her sister ships, the boat has more
than vindicated the claims of the designers. As a result
the Navy Department has decided to equip the battleship
"California'' with electric drive.
Another feature mentioned in the report was the in-
creasing use of large Diesel-engine motor ships. At pres-
ent 27 vessels holding Lloyd's classification have an aggre-
gate of 50,000 i.hp. in Diesel engines, and there are twenty
more now building.
Coal and Smoke
For a long series of years the coal produced in this
country has doubled every decade. For the past year the
estimated production is 550 million tons, or about 5
tons per capita. At this alarming rate, increasing with
each succeeding year, the supply will be exhausted at no
distant date. Conservation of the supply is thus becom-
ing more urgent. While the cheapness of the fuel has
discouraged concentrated effort, some progress has been
made. Classification of the coal is finding a constantly
widening field of application, the obstacles common to
the burning of powdered coal are being overcome and the
washing and sizing of Western coals is resulting in a de-
cided gain. Such plants as the one installed this year
at Hauto, Penn., utilize what was formerly a waste at the
mines, and in supplying the surrounding territory with
electric energy conserve the supply of coal worth shipping.
Considerable progress has also been made in smoke sup-
pression. Most of the large cities in the country are now
actively engaged in abating this nuisance, although there
24
POWER
Vol. 41, No.
is a general hesitancy in appropriating sufficient funds
for the purpose. Pittsburgh in particular has become
more active in the past year. The city is the largest con-
sumer of bituminous coal in the world and its annual soot
fall has reached the enormous figure of 1031 tons per
square mile. Truly the opportunities for "cleaning up"
great, and with the incentive awakened surprising re-
sults may be expected.
Europe is also awaking to the possibilities of smoke
prevention. Twenty-four English and Scotch cities are
making soot observations with standardized apparatus
anil methods. Educational classes for engineers and fire-
men have been started with a view to teaching them im-
proved methods of burning coal. Progress is necessarily
slow, because of the limited powers conferred by existing
laws and because societies fur the suppression of smoke
are dependent upon membership fees and donations for
the funds required to carry on the work. Finland is active
in -mioke abatement and Hamburg has a smoke-prevention
society made up of manufacturers to the number of 473.
The society is a voluntary association of large eomumers
of fuel bound together by the common interest of reducing
-moke and bettering the efficiency of their boilers.
Electrk ai. Advancement
Oct. 21 last commemorated the thirty-fifth anniversary
of the invention of the incandescent lamp. On the above
date in 187 9 Thomas A. Edison first successfully made
a carbon filament glow. It was the beginning of interior
electric lighting in small unit-, the arc having preceded
the incandescent by a irw years, although to a limited ex-
tent.
Perhaps the most notable development in switchboards
was that for the control of the Panama Canal 1.
which was completed during the early part of the year.
The 35.000-kw. generator for the Philadelphia Electric
Co. has already been mentioned. Among the more spe-
cial apparatus is the Kapp phase advancer. It consists of
three small, direct-current mot, us connected in circuit
with the rotor of an induction motor. The -mall ma-
chines set up an electromotive force in opposition to that
produced by the slip of the rotor and in this way increase
the power factor to unity or above.
In England and on the Continent considerable atten-
tion ha- been given to this problem of phase advancing.
In the former country an installation in connection with
10-hp. induction motor has been made quite recently.
A new method of self-synchronizing rotary converters has
developed and is being extensively adopted by Brit-
ish manufacturers. The General Electric Co. has per-
fected a revolving compensator with one collector ring for
obtaining the neutral connection with three-wire opera-
tion. It is to supersede the familiar separate stationary
compensator and two-collector-ring arrangement.
The use of synchronous condensers of large capacity
for voltage regulation as well as power-factor correction
has been introduce. 1 in connection with the Big Creek
development of the Pacific Light & Power Corporation.
It may be recalled that this company employs the high-
est transmission voltage vet attempted, 150,000 volts.
Outdoor substations continue to grow in popularity and
the practice of washing air for cooling electrical apparatus
has become more general during the past year. Improve-
ments have been made in oil -witches for meeting the
ral tendency toward higher raltages, and more sat-
isfactory designs of power-limiting reactances have been
developed. Equally important with the development of
new devices i- a set of safety rules governing the u-
electrical apparatus, which has been compiled during the
past year by the Bureau of Standard-. A radical revision
of the old rules was made in the basis of rating machinery.
From a thermal standpoint a rating no longer is estab-
lished by a standard rise in temperature under prescribed
conditions of load but the hottest spot in the insulation is
made the deciding factor. There is no provision for over-
loads causing a temperature higher than specified. The
owner must take all risks if he desires to exceed the limit.
Gas and On Engines
In the gas-power field there has been little new in pro-
ducer work or in gas-engine developments. Ehrhardt and
Sehmer of Saarbrucken, Germany, have increased the
power, and incidentally the efficiency, of their engines by
thoroughly scavenging the burnt gases and introducing
the fresh charge under pressure. A blower driven by a
motor or by a turbine supplied with steam from a waste-
heat boiler delivers the air and gas under a pressure of
10 to 15 lb. Due to the lower temperature from scaveng-
ing and to the pressure, a heavier charge and a better mix-
ture of live gas are obtained. The effect is to raise the
mean effective pressure and to improve conditions gen-
erally.
A distinctive advance has been made in the recovery of
waste heat from gas engines through the .Merriam process,
as developed by the Bruce-Macbeth Co. By forcing the
water in a closed circuit through the jackets at a ve-
locity five to ten times normal, the temperature can be
rai-ed to 300 deg. without endangering the cylinder. Thus
steam under pressures as high as 50 lb. can be generated
and the heat usually wasted in the jackets ■ utilized.
During the past year important experiments have been
conducted by the Engineering Experiment Station of the
Pennsylvania State College to determine the applica-
bility of kerosene, alcohol, motor spirits and mixtures of
gasoline and kerosene as substitute- for gasoline in en-
gines, also the effect of water injection with these differ-
ent fuels. Some interesting results were obtained and it
is evident that these investigations are timely, for in the
United States alone in 1914 it is estimated that 25 mil-
lion gallon- of gasoline was consumed.
The immense combination steam-gas engine- for the
Ford Co. are nearing completion. The large Humphrey
pump has been given mention. During the year several
firms have started to build Diesel and semi-Diesel oil en-
gines and several oil engines of the two-cycle, heavy-duty
type have been put on the market. An interesting inno-
vation in the delivery of oil fuel has been introduced by
the government at Port Baker. Calif. Oil i- piped through
the streets in the same way as water and gas. It is de-
livered to residences and other buildings at 30 lb. pres-
sure for use in furnaces, for heating and i-ooking and in
oil engines for power. This installation and the one at the
Presidio, San Francisco, are believed to be the first of
their kind ever attempted mi a large -rale.
Water Power
During the pas! few years the Pacific Coast lias come
forward with a greater increase in water-power develop-
ment than any other section of the United States. Im-
mense project- have been completed recently and others
are in prospect, Inn even with the rapid progress that has
January 5, 1 9 1 'r>
TO WEI?
been made only 7 per cent, of the total potential water
power in the three Coast states has been developed. Ten-
nessee, Georgia, the Carolinas and Minnesota have also
been active. During the year the low-head 10,500-hp. de-
velopment at Coon Rapids, which is to serve Minneapolis,
was put into commission. The recent agreement between
the Secretary of Agriculture and the state water commis-
sion of California on the use of water-powers within the
national forests will facilitate developments in this ter-
ritory. The Adamson bill, which passed the House of
Representatives on Aug. 1, was a noteworthy attempt to
ward off a monopoly in water power still open to title.
The regulation of service and rates was to be left to the
states. With tin's provision the governors in their annual
conference at Madison, Wis., were in accord, as they
unanimously favored state control of natural resources,
notwithstanding their declarations to the contrary in
former years.
Engineering Societies
Leading engineering societies of the country are be-
coming more active than ever before in the interests of
their respective Gelds. As their rosters contain the en-
gineering brains of the country, it is natural to expect
that they should formulate standards of design, inspection
or testing, and through the exchange of ideas on leading
topics guide practice more swiftly into channels of econ-
omy ami safety. It is gratifying to note that their recent
work has been particularly well done and should result
in lasting benefit. At a meeting early in the year be-
tween representatives of the various engineering societies
concerned and the manufacturers' committee, practically
all differences between the two schedules of flanged fit-
tings were eliminated. There is still a conflict of opin-
ion concerning the name by which the final schedule shall
be known, but a committee has been appointed to smooth
out this difference.
The work of the committee appointed by the American
Society of Mechanical Engineers to draw up standard
specifications for the construction of steam boilers and
other pressure vessels and for their care in service has
been recorded in these columns. The tentative report
of the committee has been sent to leading authorities of
the civilized world and at a special meeting all parties
interested, including steel and boiler manufacturers, were
invited to discuss the report. At the annual meeting
held in December it was expected that the committee
would be able to present its recommendations revised
in the light of the discussions and in final form at the
spring meeting in 1915. The report is voluminous and
is of the greatest importance to engineers and the public
at large, as it involves every item of consequence in re-
lation to the safety of steam boilers, from the specifica-
tions of steel to the qualifications of men in the boiler
room. The boiler makers have already organized to urge
the adoption of these rides by all of the states so that their
product may be standardized the country over. Due to
the magnitude of the movement more progress with the
various state legislatures may be expected in the year to
come than in all the years that have gone before.
The report of the power test committee of the same as-
sociation has now been revised and is being put into
final form. Tts purpose was to standardize the methods
of testing the various types of prime mover and auxiliary
apparatus. It will constitute one of the most comprehen-
sive publications ever issued by the society.
Plans for the International Engineering Congress to
be held in September of next year at the Exposition arc
well under way. It. is to be conducted under the auspices
of five leading national associations and will be presided
over by Col. George W. Goethals, who has accepted the
office of honorary president.
Boileb Explosions
During the first half of the year 1914 there occurred
340 boiler failures of a more or less serious nature. The
number reported killed was L20 and injured 240. The
estimated monetary loss was reported in 80 cases only; the
total for these was, however, $240,000, making an aver-
age of about $3000. The greatest loss, $100,000, was
from fire following the boiler explosion. The losses
resulting from minor failures are not often given, there-
fore the average loss is higher than would be the case if all
were included. Of the strictly power-plant failures GO
were tube failures, 30 were due to cast-iron headers in
water-tube boilers, and 1 7 blowoff pipes gave way.
Cast-iron heating boilers, as used or neglected, are
shown to be a menace of no small proportion. More than
70 are reported to have failed. To repeat a statement
of a year ago, "more attention should he given to this type
of boiler."'
License and Inspection Laws
Relative to the passage of state license and inspection
laws, last year's work was barren of results. The Na-
tional Association of Stationary Engineers continued the
work it has been conducting for years, and as usual ap-
propriated funds for this purpose. Fewer legislatures in
session and a difficulty in convincing those that were, are
the reasons given. To obtain uniform laws the association
has offered to cooperate with the American Society of
Mechanical Engineers.
In Canada a committee of chief boiler inspectors from
the different provinces is drawing up a uniform set of
regulations which will be adopted by the entire dominion.
During the year rules for the inspection and operation
of stationary boilers in the Canal Zone were issued by an
executive order of Governor Goethals.
For the safe use and handling of refrigerants the Fire
Prevention Bureau of New York City has formulated a
set of regulations which went into effect five days ago.
Boston also has some ideas on the subject. If regulation
is needed in these cities, it is needed in every city or state
in the country. The regulations, however, must be sound
and safe, and a uniform code is by all means desirable.
Isolated Plant vs. Central Station
The controversy between isolated-plant and central-
station interests continues, and no abatement may be ex-
pected until the legitimate field for each is more definitely
established. Indications, however, point toward progress
for the former. Such notable examples as the Ford Build-
ings in Detroit, the Federal Building in Chicago and
many others in which isolated plants have effected large
savings are proving beyond the question of a doubt the
extravagance of buying current, at a rate profitable to the
producer, when heating is to be done. The prolonged de-
lay and final reopening of the Edison rate case in Now
York City also points in the same direction. Discrimina-
tion against the small user of current who cannot compete
is having its effect cither in a reduction of rates by public
service commissions or in crystallizing sentiment toward
26
P 0 W B B
Vol. n. Xo. l
municipal ownership. At the meeting of American may-
ors in Philadelphia last November the sentiment for mu-
nicipal ownership of all public utilities was remarkably
strong. The body was representative of cities large and
small from one coast to the oilier. If the convictions of
the mayors are backed by a majority of their respective
constituents, city-operated plants should soon be the rule
and not the exception. Pasadena, Cleveland, Detroit, in
their street and public lighting, and many other cities are
showing that a municipal plant is a profitable investment
when run on a business basis.
Hoxot; Roll
Last year medals innumerable were awarded for brav-
ery, generalship and what not pertaining to war. but for
scientific achievement the only two recipients of which
we have knowledge were Prof. John E. Sweet, who was
presented the John Fritz medal, and Charles F. Brush, of
arc-light fame, with the Edison medal. Earlier in the
year the former was given the degree of doctor of engi-
neering by Syracuse University. The honorary degree of
master of science was conferred upon Gano Dunn, presi-
dent of the J. G. White Engineering Corporation, in
recognition of accomplishments and distinction in science
and electrical engineering. The Nobel prizes were sus-
pended. Of the various national engineering societies in
this country closely related to the power-plant field the
following men were elected to the presidency : John A.
Brashear, American Society of Mechanical Engineers;
C. 0. Mailloux (second year of term). American Institute
of Electrical Engineers: H. H. Scott, National Electric
Light Association ; F. L. Pay, National Association of
Stationary Engineers : Samuel P. Lewis, American So-
ciety of Heating and Ventilating Engineers: Louis Doel-
ling, American Society of Refrigerating Engineer-.
Xi:t IROLOGY
Men of prominence in the field who passed away during
the past year are mentioned in the following list: Prof.
W. D. Marks, well known in engineering circles: E. E.
Nolan and William Cooper, of the Westinghouse Electric
& Manufacturing Co. ; George J. Weber, former president
of the Weber Gas & Gasoline Engine Co. ; John C. Kelley,
founder and only president of the National Meter Co.;
Franklin Phillips, president of the Hewes & Phillips Iron
Work's; Edwin M. Hall, treasurer of the Jefferson Union
Co. ; Eugene McSweeney, president of the United State-
Graphite Co!; Prof. E. .1. Houston, co-inventor with Prof.
Elihu Thomson of tin' firsl successful are-lighting system;
Columbus Dill, known by engineers throughout the coun-
try; George Westinghouse. the well known inventor and
engineer at the head of the Westinghouse interests: John
F. Shearman, perhaps better known by bis nom-de-plume,
Peter Van Brock: Edwin M. Coryell, for many years
consulting engineer for the Cameron Steam Pump Works;
James W. Thomson, chief engineer U. S. X.. retired:
Walter Laidjaw, secretary of the International Steam
Pump Co. : H. R. Gilbert, manager of the Continental
Works of the National Tube Works Co:; W. F. ('nine.
member. of the famih known all over the country as engi-
neers; John Erwoqd, consulting mechanical engineer and
inventor of the various valves and water-tube boiler bear-
ing his name: George Willard, formerly connected with
the Murray Leu Works Co.: M. Carels, one of the found-
ers of the linn of Care! Frere Sir Joseph YV. Swan, one
of the early inventors of the incandescent electric light;
Frank 1.. Busey, engineer of Buffalo Forge Co. : George X.
Xistle, vice-president of the Illinois Engineering Co.;
Quimby X. Evans, senior partner of the firm of Evans,
Almirall & Co.: Edward B. Denny, past-president of the
National Association of Master Steam and Hot Water
Fitters: Edwin F. Williams, an authority on steam en-
gine- and a prominent designer; John 1!. Allen, a promi-
nent engineer and salesman, formerly vice-president and
general manager of the Allis-Chalmers Co. and later
Western Bales manager for the Westinghouse Machine
Co.: Albert B. Franklin, a well known heating and venti-
lating engineer: J. H. Millett, president of the Crosby
Steam Gage & Valve Co.: T. (I. Meier, vice-president and
treasurer of the Heine Safety Boiler Co.. ami Col. K. 1'.
Meier, president of the same company and one of the most
eminent mechanical engineers in the country, and Charles
A. Moore, president of Manning, Maxwell & Moore and
identified with the Shaw Electric Crane Co., the Con-
solidated Safety Valve Co., the Ashcroft Manufacturing
Co.. the Hancock Inspirator Co., and the United Injector
Co.
That the wages of engineers are not the same in Wich-
ita. Kan., as they are in Foxboro, Mass., worries one
of our contributors in this issue (page 18). He went
to the trouble of sending about seventy-five letters
to engineers in widely separated parts of the country and
found that there is no consistency in the salaries paid
engineers in similar sized plants. After all it is not sur-
prising; doctors right in the same city get widely differ-
ent prices for the same operation (sometimes their fee
depends en what the patient is able to stand financially).
So it is in all professions and trade-; (except where unions
have artificially fixed the scale of wages) ; workers are re-
warded according to their ability, and their availability.
Relative competence makes for differences in wage-, and
supply and demand have as much influence on the labor
market as any other. Mr. Pagett has made an inter-
esting little research into a subject we are all much con-
cerned about, but we do not look for any changes in con-
ditions in consequence of it.
Centra] stations h\ Germany are showing less loss of
business, because of the war. than would be naturally ex-
pected, according to a report. Tin would seem to prove
that they arc a more hardy kind of vegetation than iso-
lated plants. A mil, weeds are harder to kill than things
you want to raise.
Someone has said that "while figures do not lie. liars
sometimes figure.'' This i- not to cast any reflections
on tho<e who have taken part in the discussion of the en-
gine for the Karpen plant (page '!'• ). hut to emphasize
the possibility of arriving at results which prove
thing, or the contrary, according to the assumptions that
arc made before, during or at the end of the calculations.
One guess i- as good as another ami neither can he
bolstered up with mathematics. It is still a guess, how-
ever much it may he concealed in figures to give it an air
o! truth.
January 5, 1915 P 0 W B B
. ..::lllllllllllllllllllllllll!lllllllllllllllllllinilllll!lllllllllllllllllllllll!UNiUII Ill 1MUI : I I Ill Illlllll
27
,©1HF(
me;
i. '■ ' llllllllllllllllllllllr
Wlhy Dad ftlh© G^|
Our six 66-in.xl6-ft. return-tubular boilers are con-
nected to a common header from which steam is
taken for two 30, 52 and 6U>x36-in. cross-compound
pumping engines. Between the hours of six and nine in
the morning and evening, the hand of the recording steam
gage vibrated considerably. This action continued for
five days, or until the oiler opened wide the valve to the
gage, allowing the hand to vibrate rapidly. When the
valve was closed to the normal opening, the vibration
ceased and has not occurred since.
We are wondering what the cause of the trouble was,
and would be pleased to read what some readers think was
the cause.
A. E. Aldrich.
Newman, Calif.
The article in Power of Oct. 27 dealing with the Kar-
pen factory plant is well worth the attention of every oper-
ating engineer, as it illustrates some of the problems en-
tering into the choice of an engine. However, in the
writer's opinion, the results obtained were not quite fair
to the compound engine.
Before entering upon that phase of the subject atten-
tion is called to the efficiency allowed the generator of the
compound unit. It is evident that this machine was of
inferior make to show only 90 per cent, efficiency. The
writer is fairly familiar with the standard makes and in
no case has an efficiency as low as this been encountered
when the machine was larger than 75 kw. The correct
thing would have been to substitute a better generator.
Then, as regards the extra charge for oil for the com-
pound engine, it would seem that $100 is too much to
add. In the yearly report at the end of the article, it
was shown that the cost of all the oils used in the entire
plant was only $112.61 for six months; surely the oil
charge for the simple engine only would not exceed $100
per year. If this be true, then the additional oil used
on a compound engine would not exceed $25 ; for the cyl-
inder oil would be almost the same as on a simple engine,
while the engine oil should be approximately the same in
either case.
Approaching the question of fuel cost of the two in-
stallations, it must, first of all, be understood that in ar-
riving at the solution of the question as to the best unit
to install, the steam-heating question must also be con-
sidered. It is evident that with the steam heating elim-
inated, the compound engine would be the one to pur-
chase. But the steam heating complicates the problem
and it is necessary to consider its effect on the steam
cost.
First, take the simple engine. It is to develop 250
kw. 10 hr. per day for 300 days, with a water rate of 24
lb. per i.hp.-hr., engine efficiency 93 per cent., dynamo ef-
ficiency 92 per cent. Then the amount of steam passing
through the simple engine hourly during the eight heat-
ing months would be
250 X 21 .... n ...
0.03 X 0.92 X 0.746 = 94°4 lL (A)
The B.t.u. passing into the heating coils at a pressure
of 16 lb. abs. would be
9104 X 1034.1 = 9,724,676 (B)
This amount of heat is absorbed by the heating system
and should be charged against it. In live steam at a
pressure of 140 lb. abs. it is equivalent to
9,724,676
11-2 =815'76- (C)
Whether expressed in B.t.u. or in equivalent pounds of
live steam, this is the heat the simple engine has supplied
the heating system and its cost must be charged against it.
With an evaporation of 7 lb. of water per pound of
coal, the latter costing $3 per ton, the charge per hour
against the heating system would be
81S7 X $3 _
7X2000 ~U-'ih (D)
Likewise, since the simple engine handled 9104 lb. of
steam, the charge against both engine and heating sys-
tem per hour would be
7X2000 -V"1" (E)
For ten hours per day for eight months the cost would
be
$2,015 x 10 X 200 = $4030
It is self-evident that the difference between (D) and (E)
is the actual cost of the heal used in the simple engine.
Thus, per hour, this amounts to
$2,015 — $1,748 = $0,267 (F)
Taking up the operation of the compound during the
eight heating months it is found that the engine has a
water rate of 20.5 lb. per i.hp.-hr. Developing 250 kw.,
with an engine efficiency of 88 per cent, and a dynamo
efficiency of 90 per cent., the steam passing through the
engine per hour would be
..3.x«x«.r,t - mi "- W
The heat units given up to the steam-heating coils would
then be
8674 X 1034.1 = 8,969,783 B.t.u.
Since all the exhaust from the simple engine was to be
used, then if the compound engine was to be installed
there would not be sufficient exhaust steam. This would
necessitate using live steam to make up the difference.
Since the simple engine would supply 9,724,676 B.t.u. and
the compound only 8,969,783 B.t.u., the difference
would be
9,724,676 — 8,969,783 = 754,893 B.t.u.
Expressed in equivalent pounds of live steam at 140 lb.
abs., this would amount to
28
POWER
Vol. 41, No. 1
754,803
633 lb.
(II)
1192.2
The operation of the compound would therefore cause
the consumption of not only the steam passing through
it, but also of a quantity of "makeup" steam. The total
amount per hour would be
8674 + 633 = 9307 lb. (I)
The fuel cost per hour would be
93°7 X *3 _
7 X 2000 _ fl'9a (J)
Then the cost of steam per hour which should be charged
against the compound engine would be
$1.99 — $1,748 = $0,242 (K)
Since the engines were to operate for two-thirds of the
working year, ten hours per day, under these conditions,
the charge against the simple engine would be
$0,267 X 200 X 10 = $534
and against the compound engine
$0,242 X 200 X 10 = $484
Taking up the peak load of 75 kw., which occurs for
three hours per day for 100 days each year, it is necessary
to go through the same process. These calculations, sim-
plified, are as follows: Steam passing through simple
engine
75 X 3 X 100 X U = 84M9g u
0.93 X 0.92 X 0.746
Cost of this steam
846,395 X $3
7 X 2000
Equivalent live steam supplied co
846,395 X 1034.1
= $181.37
= 734,153 lb.
SI 57. 32
1192.2
Cost of steam for coils
734,153 X S3
7 X 2000
Steam passing through the compound engine
75 X 3 X 100 X 20.5 „Qn
0.90X0.88X0.746= m>™llb'
Equivalent steam furnished heating system
780,721 X 1034.1
— 1192.2 - = «".!>* M-
Amount of live steam that must be added on account of
compound engine not supplying enough
734,153 — 677,188 = 56,965 lb.
Cost operating compound and heating system
(780,721 + 56,965) X $3
7 X 2000
Fuel cost operating compound engine
$179.50 — 157.32 = $22.18
Fuel cost operating simple engine
$181.37 — 157.32 = $24.05
Considering the four months where 30 per cent, of
the exhaust steam is wasted, the simple engine is using
250 X 10 X 100 X 24
0.93 X 0.92 X 0-746 = 9'404'389 B"
The cost of the steam passing through the simple engine is
9,404,389 X $3
7 X 2000 " *a015-^
The equivalent live steam supplied the heating system and
used is
= $179.50
(9,404,380 X 1034.1) TO =
1192.2 100
Cost of exhaust heating
5,710,078 X S3 _
7 X 2000 ~ •"*»■<»
Charge against simple engine
$2015.23 — $1223.59 = $791.64
The compound engine during this time would use
250X10X100X20.5 , „
0.88 X 0.90 X 0-746 = 8'674'678 U'
Cost of steam
8,674,678 X $3
7X2000 =*18°8-86
Charge against compound engine
$1858.86 — $1?.23.59 = $635.27
Then the total fuel charge against the simple engine
would be
,$534 _j_ $24.05 + $791.64 = $1349.69
Tbe total charge against the compound engine would be
$484 + $22.18 + $635.27 = $1141.45
The summary of total charges would then become
Simple Engine Compound Engine
Fixed charges $1435.92 $1568.00
Fuel 1349.69 1141.45
Extra oil 25.00
Total $2785.61 $2734.45
So that, even in the face of an excessive depreciation
charge, the compound proves more efficient.
The engineer calculated that 25 per cent, of the two
total charges would be eliminated by using shavings. This
is wrong since both heating and power are under consid-
eration. If power were purchased then the shavings could
be used in supplying the live steam to the heating system
so that the entire fuel charge against either engine rep-
resents coal purchased. But assume that the engineer's
contentions are correct, then the fuel for the simple en-
gine would be represented by coal, $1012.27, and shav-
ings, $337.42 Then since the total fuel charge of the
compound is $1141.45, this would be divided as follows:
Shavings, $337.42; coal, $804.03. This is true as the
amount of shavings available is the same regardless of the
kind of power. Then the summary becomes
Simple Engine Compound Engine
Fixed charges $1435.92 $1568.00
Coal 1012.27 S04.03
Extra oil 25.00
Total $2448.19 $2397.03
L. H. Morrison.
Dallas, Texas.
The above discussion is interesting as it attacks the
problem from a different angle than the method employed
by Mr. Ory. The latter figured each machine independ-
ently and divided the cost for steam between the engine
and the heating system on the basis of the heat units
utilized. Mr. Morrison does the same thing for the sim-
ple engine. With the compound engine, he supplies the
same amount of heat to the heating system by finding
the deficiency in the exhaust, reducing it to its equivalent
in live team and charging it, along with the steam act-
ually : Mixed, against the compound engine.
In the cos! of fuel, per year, he finds a difference of
$208.24 in favor of the compound engine. By Mr. Ory's
method the saving in fuel effected by the use of a com-
pound engine amounted to $67.25. Using the same fixed
January 5. 1915
PO WER
29
charges and reducing the extra oil required by the com-
pound from $100 to $25, Mr. Morrison finds a balance
of $51.16 favoring the compound engine. In bis figuring
Mr. Ory shows a gain of $104.83 for the simple engine.
Although it was not so stated in the article, the oil
item of $100 was intended to include additional supplies
required. The exact amount to charge is, of course, a
matter of judgment, but in the writer's opinion the item
should be much nearer $100 than $23. The efficiencies
for the compound unit were placed low, as a price $766
lower than for the simple engine indicated light and cheap
construction. Naturally, this would result in lower econ-
omy and greater depreciation.
An item which would affect the balance considerably,
not touched upon in the above discussion, is the cost of
the compound engine. A compound unit of equal quality
should cost about one-fourth more than the simple unit,
or, in round numbers, $15,000. Then reducing the de-
preciation to the 5 per cent, assumed for the simple en-
gine, the fixed charges are higher by $232 and $36-1 more
than for the simple engine. Raising the efficiencies of the
compound engine and generator to those of the simple
unit would slightly reduce the fuel cost for the compound,
but there would still be a considerable balance in favor of
the simple engine.
The above figures are, of course, arbitrary, as they are
all based on assumptions, but, generally speaking, when
practically all of the exhaust steam is used in the heat-
ing season and 70 per cent, of it in the summer months,
there is little need for a compound engine. The small
saving in coal that might be effected will not warrant the
additional expenditure usually required for a good ((im-
pound unit.
Thomas Wilson.
Chicago, 111.
Ralsfiifiigl a Grana Pole
There are occasional articles in Poweb regarding the
erection of smoke-stacks, but I have never noticed any in-
formation on how to raise a gin pole with which to begin
the stack-raising job. Here in Alaska we use from forty-
Block
Approximate Positioxs of Mex Raising Gin Pole
to sixty-foot gin poles and raise them off the ground with-
out a mast. We require only three men, two at the guys
and one at the hoist.
When the pole is laid in place, the guvs arc put on,
a block of wood or a cable at the butt keeping the pole
from moving ahead. A single pulley block is fastened at
the top. The pulling line runs from the hoist through
the block back to a fixed point or dead-man in line with
the gin pole. A pole about fifteen feet long, having a
small notch cut in one end, is placed vertically under the
pulling line about midway of the gin pole. When power
is applied and the pulling line tightens up, the pole is
raised off the ground. After it is up some distance, the
pole under the cable is released and falls, but the hoist
keeps on pulling until the pole is up. (The illustration
does not show the fixed points in their true relative posi-
tions on account of lack of space.)
This is a simple and quick way to raise a pole.
Edward M. Keys, Jr.
Chatanika, Alaska.
y.
Move! Coiradleiaseir Seftttiiragl
While visiting the La Habra Valley Water Co.'s plant,
near Whittier, Calif., I saw what I thought was a good
condenser setting.
A surface condenser was set in an enlarged section of
yntake fopump
COXDEXSER IX IXTAKE CaXAL
the intake canal into which the water flows bv gravity
from wells in the hills. The general layout is shown in
the illustration. The water enters through conduit A
into receiver B. From there it is bypassed through gate
C or through the condenser tubes by opening gate D, and
by adjusting the two gates the flow is regulated.
Gate E may be used to drain off the water for cleaning
out or repairing the condenser or basin. All the other de-
tails are as in the average surface condenser plant. The
prime object is, of course, saving power by avoiding hand-
ling the cooling water with a pump.
C. R. Clark.
Anaheim, Calif.
:•;
Piimdlair&gg ftlhe Vsd^ae ©f Coed
The writer encountered a case recently in which there
was a possibility of considerable saving if a certain coal
could be economically used. His plant is served by two
rival roads which will be designated A and B. A good
free-burning coal had been obtained on road A, but its
unloading switch was so far from the boiler room that it
cost about ten cents a ton to haul the coal. As road B
could bring coal directly to the boiler-room door, it was
desirable to thus obtain the coal and save the additional
expense.
After trying several more or less unsatisfactory coals a
30
PO WEE
Vol. 41, No. 1
coal was found which could be obtained by road B and
which, with the same cost per ton on the switch, gave
better results by a laboratory test than the coal which had
been formerly shipped on road A. Upon testing in the
boiler room, however, it clinkered badly and gave a low
evaporation. The practical test alone would probably
have proved the coal unsatisfactory. As the analysis was
good it was decided to experiment further with the coal.
In the course of a few days, it was found that by altering
the depth of fire carried and the method of firing, the
coal could be burned without serious clinkering. The
evaporation went up, and this coal has since proved more
satisfactory than that formerly used. At the same time,
10c. a ton has been saved on handling.
In this case the plant superintendent acted as his own
chemist and he was fortunate in having an engineer who
was broad-minded, eager to produce results and to save
money for his company.
The writer does not argue that any coal which appears
well from a laboratory test can be used economically in
regular operation, but a good showing by a coal in the
laboratory, if properly considered, will result in an exhaus-
tive test in the boiler room and may be the means of sav-
ing much money.
William A. Dunkley.
Atlantic City, N. J.
In boiler plants where the main blowoff header leads
into a catch basin emptying into the city sewer through
a small drain, care should be taken to avoid water-ham-
mer. If the basin fills up above the end of the blowoff,
the water will flow back into the pipe as it cools slightly ;
then if another blowoff valve is opened before the water
recedes, water-hammer is almost sure to occur. I know
of such a case where one man lost his life when a fitting
ruptured. Beware of short bends and water in blowoff
pipes.
John F. Huest.
Louisville, Ky.
Jsotifliracal
In starting four feed pumps in a new power house
not long ago, it was discovered that the feed-water heat-
ers were set too low to supply the upper suction-valve
chambers of the vertical feed pumps when the water was
over 200 deg. F. The erecting and consulting engineers
admitted that a mistake had been made, but they were
powerless to remedy it. After it had become necessary
to cut the steam off the heaters to secure quiet working
of the pumps, reducing the feed-water temperature to
150 deg. F., the operating engineers connected a pipe be-
tween the upper suction-valve chamber of the vertical du-
plex feed pump with the return tank, so as to relieve the
heater of the high back pressure.
Weaker springs were put on the upper suction valves
so that the valves would open and admit water at a lower
vacuum than before the change. The vapor which here-
tofore filled the suction pipe and pump-valve chambers
now found an outlet through the vapor pipe. The result
was that the pump worked without slamming and the
feed-water temperature increased to 210 deg. F.
Jacob R. Rezniem.
Brooklyn, N. Y.
Oil SfiSniiminmeB'
The illustration shows an oil skimmer which I believe
will clear the receiver of most of the cylinder oil. At one
end of the receiver is a spray pipe with holes in only one
side. City water is turned on when the receiver is
City Pressure Water
rP/pe
Perforated Pipe in Receiver
overflowing and the force of the spray skims the oil from
the water and drives it toward the overflow and to the
sewer. If this is done once a day there will be little or no
trouble from cylinder oil.
A. C. Waldron.
Revere, Mass.
The illustration shows how a handy adjustable socket
wrench may be easily made. One end of two flat bars is
formed as shown at C. Bolts A should be threaded for
Home-Made Wrench
quite a length to afford adjustment. A hole B will be
found convenient at the top for a bar to turn the wrench.
An extension bar may be used to lengthen the wrench
when used in a cramped place.
James E. Noble.
Toronto, Ont.
anuary 5, 1915 POWER 31
ijihijiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiin
IimqfujinFies of Qemieiml Imitteiresil
&.:..
Common Exhaust Line for Several Engines — Is it good
practice to have several noncondensing engines exhausting
into one exhaust line?
E. C. P.
It is general practice to have a common exhaust line for
several engines, and it works satisfactorily providing the main
exhaust line is large enough for handling the exhaust from
all the engines without materially increasing back pressure on
any of them.
case of a vacuum gage, the absolute pressure will be the
atmospheric pressure minus the difference of pressure indi-
cated.
Temperature of Oil Discharged from Step Bearings of
Steam Turbines — What temperature is proper for oil dis-
charged from the step bearing of a steam turbine?
B. H. C.
The maximum oil temperature permissible will be deter-
mined by the viscosity of the oil for the temperature at which
it is discharged. Using a good quality of oil for the step
bearings of large vertical Curtis turbines the temperature of
the discharged oil is about 150 deg. F., thereby attaining a
rise of about 50 deg. F.
Cost of Operating Electric Motor — What would be the cost
of operating a 100-hp. motor using current costing 2c. per
kw.-hr. ?
C. W. R.
One horsepower equals 746 watts, and 100 hp. would equal
100 X 746 watts, or
100 X 746
1000
With a motor of 91 per cent, efficiency, the input required for
an output of 100 hp. would be
100 X 746
kw.
1000 X 0.91
and with current costing 2c. per kw.-hr. the cost would be
100 X 746
X 0.02 = $1.64 per hr.
1000 X 0.91
Variation of Water Column for Difference of Temperature
— When our boiler is operated at 100 lb. gage pressure, and
the temperature of the water in the column and connections
is 95 deg. F., the water level shown by the glass gage is
30 in. above the point where the water column connects with
the boiler. How much higher would the water level show
in the glass gage if the temperature were the same as the
temperature of the water in the boiler?
M. C. R.
For 100 lb. gage pressure the temperature of the boiler
water would be about 33S deg. F. A cubic foot of water at
95 deg. F. weighs 62.06 lb. and at 338 deg. F. weighs 56.01 lb.
For producing the same hydrostatic pressure at the foot of
the connection the height of water column would be inversely
as the density of the water. Therefore with a density cor-
responding to the temperature of the boiler water the water
level would stand
(30 in. X 62.06) -4- 56.01 = 33.24 in.
above the foot of the connection — i.e., it would show about
ZVi in. higher level than with the water in the connections
at 95 deg. F.
Obtaining Absolute Pressures from Gage Readings — Why
can not the dial of an ordinary Bourdon spring pressure
gage be laid off to indicate absolute pressures by direct read-
ings?
C. J. R.
The tube of a Bourdon spring gage is moved by the differ-
ence of pressure inside and outside of the tube, and for indi-
cating absolute pressure either the interior or the exterior
pressure would have to be constant. As ordinarily constructed
the exterior of the tube is exposed to atmospheric pressure,
and as this is variable the dial is laid off only for pressures
above or below the atmosphere. Hence "0" gage pressure is
atmospheric pressure, and as the gage indicates the difference
between atmospheric pressure and the internal pressure, then
when the internal pressure is greater than atmospheric pres-
sure, as in the ordinary pressure gage, the absolute pressure
will be gage pressure plus atmospheric pressure. When the
internal pressure is less than atmospheric pressure, as in the
Heating Value of steam at 4 lb. and at 80 lb. Pressure —
What is the relative heating value of steam at 4 lb. and at
SO lb. gage pressure when used in a pipe coil or radiator and
discharged to a trap?
H. W. J.
Considered with reference to the weight of steam received
by a radiator and discharged as condensate at the same
pressure, the heating value in each case would be its latent
heat of evaporation. The latent heat of a pound of steam at
4 lb. gage pressure is about 962 B.t.u., and for 80 lb. gage
pressure it is about S91 B.t.u. Therefore, the heating value of
962
steam at 4 lb. pressure would be times, or have about
891
7 per cent, greater heating value than the same weight of
steam received and discharged as condensate at 80 lb. pres-
sure.
Considered with reference to heating effect from a given
amount of radiator surface, the steam of higher pressure
would also be at a higher temperature and the radiation of
heat would be more rapid, depending on the difference between
the temperature of the steam and that of the surrounding
atmosphere. With the temperature of the surrounding at-
mosphere at 70 deg. F. in each case, then as the temperature
of steam at 4 lb. gage pressure is about 225 and at
SO lb. gage pressure is about 324 deg. F., for the
same radiating surface the relative rate of radiation would
be (225 — 70) to (324 — 70). or as 155 to 254 — i.e., only about
155
or 61 per cent, as much heat would be radiated from a
254
coil or radiator supplied with steam at 4 lb. as from one
supplied with steam at SO lb. gage pressure.
Factor of Evaporation ivith Superheater — What would be
the factor of evaporation for the performance of a boiler
with a superheater where the following averages were ob-
served?
Absolute steam pressure in steam drum 150 lb. per sq. in.
Absolute steam pressure at entrance of super-
heater 149 lb. per sq.in.
Absolute steam pressure at outlet of super-
heater 147 lb. per sq.in.
Temperature of steam at outlet of superheater. 47S.5 deg. F.
Temperature of feed water 100 deg. F.
W. F.
Considering the superheater as a part of the boiler, the
factor of evaporation of the boiler should be based upon the
pressure and temperature of the steam at the outlet of the
superheater, viz.: 147 lb. absolute and a temperature of 478.5
deg. F. The temperature of dry saturated steam at 147 lb.
absolute is 356.9 deg. F.. therefore a temperature of 478.5
deg. F. would represent
178.5 — 356.9 = 121.6 deg. of superheat.
Referring to the Marks and Davis steam tables, the total
heat of a pound of steam at 147 lb. absolute when superheated
120 deg. F. is 1259.4 B.t.u. above 32 deg. F., and when super-
heated 130 deg. F. is 1264.5 B.t.u. By interpolation between
these values, the total heat per pound of steam at 147 lb
absolute, superheated 121.6 deg. F., would be
1259.4 + [('2&^3o Z i?o9 4) X U21tt ~ !20,1 = 1260.21 B.t.u.
so that with feed water at 100 deg. F. each pound of feed
water evaporated into steam at 147 lb. absolute and 47S.3
deg. F. would receive
1260.21 — (100 — 32) = 1192.21 B.t.u.
The latent heat of evaporation of water from and at 212 deg.
F. being 970.4 B.t.u. per lb., the factor of evaporation under
the condition stated would be
1192.21
= 1.2286
970.4
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
32
POWER
iiiiiiiiiimiiiiiiiiiiiinii!' liiiiiiiinniiiiiiiiiiiiinii
Vol. 41, No. 1
mil iiiiimiuiiiiiiiuiiiiiiiiiiiiiiiiiiiiiiig
,imgiiinieeiH
>tknd
<DVlFi
Ps»©Ibletn&s isa P©w©ir<=PlgiE&t
Desa^sa°=XSH
Water Supply and Fire Protectiox, Coxtixued
The quantity of water required and the horsepower
necessary for pumping it from the river to the reservoir
have already been approximated, but in designing the
pumping outfit it will be necessary to go over the matter
a little more carefully.
The maximum supply was based on that required for
condensing and was taken as 7000 lb. approximately per
min. This made an allowance for the exhaust from aux-
iliaries and assumed that the total amount of steam sup-
plied to the engine would be discharged into the con-
denser.
In the final arrangement of the plant it was decided
to utilize the exhaust from the auxiliaries in a feed-water
heater, and in making the more accurate computation we
will make use of Table 1 in last lesson, which takes cyl-
indei condensation into account. Thus
670 X 15 " 35 „n„ ,
60 a 8-3 = '°' 9al Per "Un-
will be required. It will be remembered that 670 hp.
was required for the entire plant; 15 is the water rate
minus 10 per cent, and 35 is the pounds of water re-
quired to condense a pound of steam.
In the present case the surface of the river is 50 ft.
below the power house, so it will be necessary to locate
the pump in a special building at such an elevation that
the total suction lift will not exceed 15 ft. With this
arrangement a motor-driven centrifugal pump would
seem to be well adapted to the conditions presented. Such
a machine requires but little attention, it may be shut
down from the engine room, and power is easily trans-
Fig. 1. Pumping Water Supply from River
mitted from the central plant. There is little choice
in a case of this kind between the triplex plunger pump
and a centrifugal, but the latter is simpler in construc-
tion and may be driven by a direct-connected motor with-
out the use of gears or belts.
In the design of the pumping plant the first step is to
find the size of main between the pump and the reservoir,
which is usually fixed by the relation between the sav-
ing in cost of pipe and the increased cost of pumping
against a greater head. A large pipe reduces the friction
and therefore saves in pumping expenses, but it costs
more to install. Under average conditions a velocity of
2 ft. per sec. for pipes up to 10 in. in diameter,
and a velocity of 3 ft. for larger sizes, seem to give
about the right balance between the cost of pipe and that
of pumping.
A table of velocities and friction heads for water pipe
shows that a 10-in. pipe will discharge 750 gal. per min.
Fig.
Two Cexteifugal Pumps ox Water Supply
at a velocity of 3.06 ft. per sec, and with a friction head
of 0.18 lb. per in. or
0.18 X 2.3 = 0.41 ft.
for each 100 ft. For the entire run of 500 ft. this gives
0.41 X 5 = 2.05 /*.
As the run is of comparatively short length, a velocity
of 3 ft. per sec. will be assumed and a 10-in. pipe used.
Doubling this friction head to include bends and valves,
and adding 6 ft. for the elevation of the reservoir, gives a
total lift of
50 + 4 + 6 = 60 ft.
to be pumped against. Assuming a slip of 30 per cent,
the pump must have a rated capacity of
70? -=- 0.7 = 1010 gal. per min.
under a head of 60 ft. A table of centrifugal-pump ca-
pacities states that a pump with a 21 -in. impeller and a
7-in. discharge outlet will deliver 1058 gal. per min.
under a 60-ft. head at a speed of 655 r.p.m. This is the
size that should be used in the present case. Assuming
an efficiency of 60 per cent., the horsepower of motor for
driving it will be
707 X 8.3 X 60
33,000 X 0.6
= 18
say. 20 hp. to make it a standard size. Two pumping
units are provided, Fig. 2, and with the pipe sizes used
they may be operated together when a large supply of
water is wanted, as in case of fire.
Ki>ervoir
It was assumed in a previous article that the reservoir
should have a storage capacity equal to that required for
a day's run, which we will take as a maximum of 8 hr. and
which calls for
;n; X 60 X 8 = 339,360 gal.
A reservoir 50 ft. in diameter by 30 ft. in height will give
an excess capacity of about 100,000 gal. By duplicating
January 5, 1915
POWER
33
the pumping machinery it would probably not be neces-
sary to provide so large a storage reservoir, because in
case of a breakdown to both of the pumps the engine
could be run noncondensing, and a storage capacity of
half the above would be ample for boiler feeding and fire
purposes during a temporary shutdown of the pumping
plant.
It will be sufficient to provide a concrete reservoir 50
ft. in diameter by 15 ft. in depth, extending 6 ft. above
grade. This will make it possible to drain it into the
main sewer, and also, under normal conditions, there will
be sufficient head to cause the water to flow to the pumps
and to the receiving tank and boilers by gravity. Dia-
grams showing the general arrangement of the pumping
machinery, pipe line and reservoir are given in Figs.
1 and 2.
Fire Protection
A system of fire protection consists 'of two parts — one
for outside service, made up of hydrants and their un-
derground connections, and a sprinkler system for inside
protection. The rules for laying out a system of this
kind vary somewhat in different localities, and the pro-
posed system should be submitted to the fire underwriters
for that district before its installation. The following
data are general in character and correspond to average
conditions.
Water Supply
There should be two independent supplies, one of which
should be automatic and capable of furnishing water
under a heavy pressure. Common sources of supply are
a pond, river or large reservoir from which the water is
drawn by a pump, city mains, and elevated or pressure
storage tanks. A combination of any two of these will
usually give sufficient protection.
Pumps
Standard fire pumps have capacities of 500, 750, 1000
and 1500 gal. per min. The 1000-gal. size is the one
most frequently used, although many 750-gal. pumps are
installed. The 500-gal. size is only for use in the small-
est plants. It is more common to have two smaller pumps
than a single large one of 1500 gal. capacity. The pumps
most frequently used for this purpose are the direct-acting
steam pump, rotary pump and electrically driven pumps,
while turbine or centrifugal pumps are also employed
to some extent. All of these pumps are made in stand-
ard sizes for this purpose. The pumps should always be
duplicated and so connected that they may be run either
singly or together.
Outside Protection
Hydrants are commonly placed from 150 to 200 ft.
apart and provided with two to four hose outlets each,
three being the standard. They should be located about
50 ft. from the buildings they are to protect, depending
somewhat upon the height. There are two general
methods employed for supplying the hydrants, known as
the 'loop" system and the "dead-end" system ; they are
sufficiently described by their names. The former is
usually preferable, as smaller mains may be used, the
supply coming from both directions. The number of
hose outlets supplied from mains of different sizes are
given in Table 3 :
TABLE 3. NUMBER OF HOSE CONNECTIONS
Length of
Main, Ft.
250
Number of
Hose Outlets on
"Dead-End" System
Number of
Hose Outlets on
"Loop" System
A two-way hydrant should have a 5-in. gate and three-
and four-way hydrants have a 6-in. gate. While the
largest mains given in the table are 8 in., large plants will
often call for 10- and 12-in. mains.
Sprinkler Systems
The spacing of the sprinkler heads will depend some-
what upon the construction of the building. For stand-
ard mill construction, the spacing given in Table 4 may
be used, with one line of sprinklers in the center of each
bay. Pipe sizes are given in Table 5.
TABLE 4. SPACING OF SPRINKLER HEADS
Distance Between
Width of Bay, Ft. Sprinkler Heads, Ft.
6 to S 12
10
TABLE 5. PIPE SIZES FOR SPRINKLER SYSTEM
Number of Number of
Pipe Size, In. Sprinklers Pipe Size, In. Sprinklers
3>/2
55
4
80
5
140
6
200
When an elevated tank forms one of the supplies for
a sprinkler system it should have a capacity of 10,000 to
20,000 gal., 15,000 being about the average.
Pressure tanks may be made somewhat smaller on ac-
count of the higher pressure carried. A tank of 6000-
gal. capacity corresponds to one of 10,000 of the elevated
or gravity type. In practice it is customary to use two or
more smaller pressure tanks rather than a single larger
one on account of the expense, 8000 to 9000 gal. being
H a" 6" h
rl tO* lj* - K>
\io"
Forge
Shop
Foundry
JL 6
^v I ' Reservoir
Machine Shop
Sprinkle.
Office
Wing
H$
H$
\5
H H 8"
Fig. 3. Layout of Hydrants and Outside Piping
about the limit. In general, tanks of this kind are located
above the sprinklers, kept about two-thirds full of water
and subjected to a pressure of 75 lb. per sq.in., which in-
sures a pressure of 15 lb. when the tank is empty. Both
elevated and pressure tanks may be made to connect with
a general system of fire mains, from which the sprinkler
system takes its supply, provided there is sufficient head
to maintain a minimum pressure of 15 lb. at the highest
sprinkler heads.
34
P 0 W E R
Vol. 41, No. 1
According to Table 4. the following number of sprink-
lers will be necessary in the rooms to be protected : Office,
10: drafting room, 40; pattern shop, 40; pattern sto
50 ; carpenter shop. 24 : paint shop. 6 : a total of 200.
Assuming that 60 sprinkler heads will require 250 gal.
of water per min., the total requirements for one hour
for this purpose will be
200 X 250 X GO Rn nnn
— = 50,000 qal.
60 J
which is only about one-third the capacity of the storage
reservoir and therefore well within allowable limits.
The general layout of the hydrants and outside piping
is shown in Fig. ■".. The loop system is employed for the
Air Compressor.
Air Pressure
Pressure Tank
J
V7/.
Fire Pumps rL
1 ' «"'■■
7777777777Z—
Fig. 4.
Arrangement of Water-Pressure Equip-
ment ix Power House
outer system of hydrants, with a dead-end supply for
the sprinklers and two yard hydrants as indicated.
Inside standpipes, with hose connections, are provided
in the machine shop, office wing, foundry and carpenter-
shop storage at the points marked A on the plan. While
an 8-in. loop has a capacity of but eight hose outlets, it is
assumed that not more than this number will ever be in
use at one time, although there are 9 three-way hy-
drants on the line.
The arrangement of the pressure equipment in the
power house and the various pipe connections are shown
in Fig. 4. A pressure of 100 lb. per sq.in. is constantly
maintained on the system for automatic sprinkler supply
by means of a pneumatic tank having a capacity of 6000
gal. With the tank two-thirds full and the air space above
it subjected to this pressure, there will be at least 15 lb.
upon the highest sprinklers when the tank has discharged
it- entire contents.
The tank is filled by means of a special pump, indicated
in the drawing, which should be arranged by means of
a float valve to maintain the normal water line automatic-
al'}' and thus offset the effect of any leakage in the sys-
tem. The pressure should also be maintained automatic-
ally by means of a compressor actuated by changes in
the system.
Two 1000-gal. direct-acting steam pumps are provided.
While one is furnished as a relay, the pipe connections
are such that the}' may be operated together in case of
emergency. A pump of the type and capacity used will
supply four standard fire streams and will require about
150 boiler-horsepower for operating it.
S
Scaesatla^BC Holies0 Feedlaiagg
By E. W. NICK
It is well known that it is impossible to quickly change
the intensity of furnace fires and the rate of boiler feeding
with every change of load. When the load changes there
should be a corresponding change in the rate of feeding,
which should be slow enough to allow a gradual and econom-
ical change in the furnace fires.
There are advantages obtained by lowerinr the water
level to secure greater steaming capacity for peak and over-
loads, and raising it during subnormal and no loads to save
heat energy. A continuous feed and a scientifically varied
water level are desirable features to obtain by any method
of feeding.
When a demand for an additional supply of steam occurs,
it is not necessary to immediately increase the supply of feed
water. Part of the water already within the boiler and at
boiler temperature can be evaporated into steam and this
process may continue until the water has dropped to the
lowest permissible level. Conversely, when the demand for
steam falls off, it is not necessary that the amount of feed
water be simultaneously decreased. On the other hand, the
amount of water in the boiler can be increased so that the
heat which would otherwise be lost is saved and utilized
for heating up additional feed "water.
Suppose, for example, that the load on a boiler suddenly
increased by 100 per cent. If the rate of feeding water were
increased at the same time by the same amount, then the
furnaces would at once have to generate 100 per cent, more
heat in order to keep up the steam pressure. This cannot
be done, and therefore the steam pressure drops somewhat
-.
o
/
\
i. .
<u 13
;
1
\
"•S.
\
\ /
v
~r
■"""
o
^
h
\
/
!
\ i\
i "^
/
E 11
_J
V '
m
.VI
D WATER 1
\
/
57-
1HPBOIU
T '
-:
o
C 9
i/
\
;
'
'
155 201 209
217 225 233
Time P.M.
241 249 2.57
Fig. 1. Simultaneous Readings of Feep-Water
Fluctuations and Steam Output
and the heat stored in the water is called upon to make steam
Obviously, the last thing to do under such circumstances is
to inject a large volume of cold water into the boiler.
If the rate of feeding does not increase when the load
increases, then the additional feed water need not be heated
and the momentary load on the boiler is increased by only
SO per cent., since the amount of heat required to heat the
feed is about 20 per cent, of the total. If the feed water
were cut off when the load jumps 100 per cent., then the
momentary overload amounts to but 60 per cent.
For high economy, all the boilers in a battery should
operate with the load evenly distributed. The efficiency of
a boiler falls off gradually as the load is increased and rapidly
as the load decreases below normal. It is important that all
boilers of a battery work at uniformly high capacities.
Suppose that the five boilers of a battery are working at
five capacities and delivering a total of 75,000 lb. of steam
per hour with a total battery efficiency of 69 per cent. If
the boilers were worked at a uniform high capacity, each
of the five boilers would generate exactly one-fifth of the
steam and the average battery efficiency would be ~2 pel
cent., or a net gain of 3 per cent.
January 5, 1915
P O W E R
35
The unequal distribution of load between the boilers of
>attery is caused by differences in condition of fire, of coal,
ide of firemen or condition of the stoker, the draft pressure,
ldition of setting as to leaks, condition of boiler surface
to soot and scale, the position and condition of the dampers,
1 to the rate of feeding the water.
If a feed-water regulator is so designed that the feed
:ve cannot assume an intermediate position on light loads,
; valve will be closed for long periods and open for short
'iods. On heavy loads the valve will be wide open for
ig periods, thuc causing a fluctuating steam output and
ling to feed in proportion to the rate of evaporation.
~° 5
g -
D
.It
°-.
I . . -
1
/
u
V.
5
ii
j..
pi
t
\/
\
V
e 400
\
3
•v
/
K
-
v
/
3 « 6
V.
t-.
I
1
y
r
r
£\*f;;!&
F
Val v i
oL,
t '•- - , 3
-h
~r-
>
O &*"
/
J
Fig. 2.
Showing Load Artificially Vaeied from
Zero to 270 Per Cent. Capacity
When feeding by hand regulation, the water tender can-
not follow a fluctuating load and at the same time make the
proper allowance for the influence of the load and the steam
pressure on the height of water observed in the gage-glass.
A steam flow meter on each boiler to guide tlie firemen or
stoker attendant has proved successful in regulating indi-
vidual boiler loads, but hand feed causes wide and misleading
fluctuations in steam-flow meter readings. The steam de-
livery and flow meter reading may be reduced from a heavy
overload to practically zero load by the sudden injection of a
large volume of cold water. This is illustrated by the curves
of Fig. 1, which show simultaneous readings of the feed
water and the steam output of a boiler forming one unit
of a battery on which there was a constant load, the fireman
relying on the steam gage and water column as a gui^e in
regulating the feed water. Under such conditions the advan-
tages resulting from the use of steam-flow meters cannot
be realized because the readings cannot be used as a guide
to regulation.
The water tender and fireman often work at cross pur-
poses. The fireman assumes that the pressure gage and
steam-flow meter readings indicate the boiler and furnace
load and the rate at which heat is being absorbed from the
furnace by the boiler, whereas the accuracy of the readings
may be destroyed and their utility nullified by improper feed.
If every boiler were fed continuously while under load,
and if at the same time the water level were varied inversely
with the load, this trouble would disappear and all boilers
would receive a share of the feed in proportion to the furnace
load. If the steam delivery of a boiler, as indicated by the
flow meter, is too low, it is corrected by speeding up the
stoker, cleaning the fires, opening the dampers and regulating
the air supply; then the increased heat generated causes an
increased steam delivery, which in turn causes the proper
increase in feed supply.
A feed-water regulator should make the rate of feeding
dependent upon the furnace load, and so long as each furnace
of a battery generates its share of the heat, each boiler of
the battery will receive its share of the feed water and gen-
rate its share of the steam.
To meet the foregoing requirements an automatic boiler
feed regulator should have the following characteristics: On
light loads the water level should be high, so that the boiler
stores a maximum amount of water and heat. Conversely
on heavy loads, the water level should drop, the heat of the
furnace being used for evaporating water in the boiler and
not heating cold feed.
To secure this fall in water level, the feed valve should
close off the feed somewhat, when the load suddenly increases,
thus increasing the heat available for evaporating the water
already admitted. However, as the water level falls due
to evaporation, the regulator must increase the rate of feed
until the amount being fed equals the amount being evapo-
rated
With a sudden decrease in load, the regulator must not
decrease the feed until the water level has risen to the
maximum and should even open up the feed valve to rapidly
inject cold water, so as to absorb the heat which would
otherwise be uselessly generated by the furnace. After the
water level has reached the maximum permissible height,
the feed must be decreased or shut off. Finally, the regulator
should be reliable and automatic so that when the load is
removed from the boiler the feed water will be shut off.
That these conditions are not impossible of accomplish-
ment with an automatic device is evident from Fig. 2. These
readings were taken on a boiler whose load was intentionally
varied from zero to 1600 hp., corresponding to almost 300
per cent, rating. The maximum steam output is accompanied
by the minimum water level, followed by a rising water level
as the load decreased and a maximum water level at the
minimum output. The feed-valve opening does not reach the
maximum until some ten minutes after the first peak, showing
how the water in the boiler is allowed to evaporate down to
the minimum level before the feed valve opens to compensate
for the increased load.
Similarly, while the load fell to zero at 1:10, the feed
valve did not close until some ten minutes later and only
after the water level had reached the maximum permissible
level and cold water had been pumped into the boiler, so as
to store and save heat.
Another proof of the practicability of this method of feed
is shown by Fig. 3. This covers readings on the boilers of
the Municipal lighting plant, Jacksonville, Fla. The load
varied from 1000 to 4000 kw. The water and load lines
have the same general shape, indicating that the feed is in
proportion to the load. As with the previous chart, however,
the feed does not respond to a change in load until the
thermal capacity of the boiler has been utilized.
The first example occurred at 4 o'clock, when the load
suddenly dropped from over 2000 to just over 1000 kw. This
drop in load, instead of causing a decrease in the rate of
feed, was accompanied by a rise in the rate of feed from
60,000 to 75,000 lb., the additional water thus pumped into
the boiler saving and storing heat. After 4:10 the boilers
were obviously filled to the highest permissible level and
the rate of feed fell off. The constantly increasing load from
this time up to 6 o'clock is accompanied by a corresponding
increase in the rate of feed. At the first peak of the load,
occurring at 6 o'clock, the amount of water fed to the boiler
fell from about 86,000 to S0.000 lb., indicating how this
method of feeding helps to carry peaks. At 7:10, when the
load went up again to the maximum, the rate of feed fell
from 77,000 to 70,000 lb., not increasing again until the peak
had persisted for some time, when the water level had fallen
and it was necessary to increase the rate of feed to prevent
the level from going below the minimum. L. B. Murphy,
I 180
-.
S
Ll
V
-'"■"
i 170
" 100
„ 20
on
,.,<
Wa
/
\
/
=
/
\
tt- ..
4000
L..
-I
3000
2000
1000
Fig
3. Performances of Feed-Wateb Regulator
Municipal Plant, Jacksonville, Fla.
chief engineer of the plant, states that "Our fuel consumption
goes up 4 to 5 per cent, for a given kilowatt output when the
regulators are not in use."
From the foregoing it is obvious that a continuous-feed
regulator makes it possible to use a smaller feed line, smaller
valves, and smaller boiler feed pumps for a given boiler
horsepower output, or it permits forcing of the boilers without
the usual increase in size of lines, fittings and pumps. This
is true because the control valve does not close unless the
boiler is shut down, and furthermore the valve maintains an
intermediate position, so that water is continuously fed to the
boiler. As a result, the valve is not called upon to open to
36
POWE E
Vol. 41, No. 1
its full extent and is operating tar below its maximum
capacity. On new installations the saving in the cost of
fittings covers a large part of the cost of such a regulator.
As boilers are driven at higher and higher loads by the use
of mechanical draft and stokers, greater feed capacity is
needed and this is amply provided by a suitable system of
regulation.
When the rate of feeding varies spasmodically, with con-
sequent variations in the steam delivery, the temperature of
superheat also varies through a wide range. The hot gases
flowing over the superheater tubes transmit to them a prac-
tically constant amount of heat, so that if the steam delivery
is suddenly decreased by injecting a large volume of cold
water, there is a sudden rise in steam temperature. With
proper regulation of feeding there are no sudden or spas-
domic variations in the feed, hence no spasmodic variations
in the steam delivery; consequently, undue fluctuations in
steam temperature produced by the superheater are prevented.
With open feed heaters the efficiency is increased when
the rate of feed is even and not subject to wide variations.
If the demand for feed water is large, due to excessive feed-
valve opening, the water level in the storage space falls low
and the float-operated makeup valve opens wide, introducing
an excessive amount of cold makeup water with a resulting
decrease in temperature. On the other hand, if the feed valves
are closed too far, the makeup water is shut off, due to the
high level of the water in the storage space, and steam may
be wasted to the exhaust. Furthermore, if the feed valves
remain closed very long the water in the heater overflows
to the sewer and wastes both heat and water.
Mr. Ulrich was born in Apolda, Thueringen, Feb. 19, 1852
He studied in the Gymnasium in Apolda, was graduated from
the Royal Institute of Technology in Chemnitz, Saxony, and
later from the Polytechnic Institute in Karlsruhe.
In the capacity of mechanical engineer he was engaged by
several large concerns in Germany for the design, sale and
supervision of large machinery installations in the Russian
Empire, Finland, etc. He also traveled extensively in Italy
and other countries on the Continent.
In 1SS2 he came to America and was connected with con-
cerns in Cincinnati, St. Louis and Chicago, and in 1885 as-
sumed the position of chief engineer of the Weisel & Vilter
Manufacturing Co., now the Vilter Manufacturing Co. In 1888
he became a stockholder and director, and later general sales
manager.
During his 29 years' continuous connection with the com-
pany he aided materially in developing the business to one of
the largest establishments of its kind. In the performance of
his duties he visited a great many of the ice-making and re-
frigerating plants in the United States and Mexico, and his
wonderfully retentive memory enabled him to accurately re-
call small details years afterward. In the solution of all prob-
lems his highly trained, keen and observant mind was of
invaluable assistance. He was thorough and conscientious in
all business matters, always actuated by a high sense of honor
and justice, and while generally inclined to be serious, he
had flashes of dry humor which disclosed his deep insight into
men and affairs. His demise is a distinct loss to his associates
and the refrigerating world.
Mr. Ulrich is survived by Mrs. Ulrich, two daughters and
a son.
"""3
TIRADE CATALOGS
FRED ULRICH
Fred Ulrich, general sales manager of the Vilter Manufac-
turing Co., Milwaukee, Wis., died Dec. 10, at his home, 2720
McKinley Boulevard, Milwaukee, after a short illness.
American District Steam Co., N. Tonawanda, N. Y. Bul-
letin No. 133. Atmospheric System of Steam Heating. Il-
lustrated, 30 pp., 6x9 in.
American Boiler Life Co., 19 N. Market St., Boston, Mass.
Pamphlet. "The Scientific Treatment of Steam Boilers and
Boiler Feed Water." 8 pp., 5xS in.
The Hoppes Mfg. Co., Springfield, O. Catalog No. 60. Feed-
water heaters, purifiers, steam separators, V-Notch water
meters, etc. Illustrated, SO pp., 6x9 in.
The Direct Separator Co., Syracuse, N. V. Catalog. Direct
flanged steam fittings, American and U. S. 1915 standard.
Sweet's separators, etc. Illustrated, 44 pp., 4y2x7 in.
The Industrial Instrument Co., Foxboro, Mass. Bulletin No.
86. Foxboro differential recording gages and orifice meters
for gas. Illustrated, 20 pp., Sxll in. Bulletin No. 91. Foxboro
thermometers and thermographs. Illustrated, 52 pp., Sxll in.
Builders Iron Foundry, Providence, R. I. Bulletin No. 84.
The Venturi meter for gravity mains, pump discharge lines,
refrigerating plants, etc. Illustrated. 36 pp.. 6x9 in. Bul-
letin No. 85. Venturi hot water meter for boiler feed, etc.
Illustrated, 20 pp., 6x9 in.
BUJSIHESS STEMS
Fhed Ulkicii
The National Belt Dressing Co., 220 Broadway, New York,
is placing "National" belt dressing on the market.
The pipe insulation contract for the new Utah State Capitol
at Salt Lake City, for which R. K. A. Kletting was the archi-
tect, and Jas. C. Stewart Co., contractors, was recently
awarded to the H. W. Johns-Manville Co., 41st and Madison
Ave., New York.
Due to the death of Quimby N Evans, the copartnership
heretofore existing between Q. N. Evans, J. A. Almirall and
W. C. Adams, has been dissolved and the corporation of
Almirall & Co., Inc., No. 1 Dominick St., New York, has
succeeded to that business.
The Goulds Manufacturing Co., manufacturer of triplex,
centrifugal, hand and spray pumps, Seneca Falls, N. Y., has
just opened a new office in Atlanta, Ga. The office will be
located in the Third National Bank Building and will be in
charge of Mr. O. B. Tanner, district manager.
A booklet which will interest every man seeking improved
boiler results has just been published by the American Boiler
Life Company, 19 North Market St., Boston. Mass. It tells
things about scale removal, about the prevention of scale
and pitting and foaming that are not only interesting but
instructive. Copies are mailed on request. The title of the
booklet is "Steam Boilers and Boiler Feed Water."
The Mesta Machine Co., of Pittsburgh, Penn., has recently
acquired the rights from the Stumpf Una-Flow Engine Co., of
Syracuse. N. Y., to build the Stumpf Una-Flow type of
engine in the United States. The agreement not only gives
the Mesta Machine Co. the patent rights of Professor Stumpf,
but includes the use of the knowledge gained by the practical
experience, during the past five or six years, of European
builders of Stumpf engines. The large number of engines
of this tvpe in operation in Europe gives conclusive proof
of its superiority in regard to simplicity, economy, etc.
POWER
Vol. II
XI'.W Vo|;K. JANUARY 12, 191!
Purposeful
©(titer
TUmmi
For (/"
F-<r (At
For fA
IT IS NOT HARD to get authority to purchasi a safety
device after the need of it has been driven home by a sacri-
fice of property and perhaps life. It is another matter to
convince the management of such a need where an acci-
dent never occurred.
The owner of a certain Factofj in-i illi d a complete system of
accident-prevention appliances — at least ii was intended to be
complete. Every gear, pulley, belt or stairway was protected
with the most elaborate devices in the market, but —
When the engineer complained that his part of the plant
was being overlooked, and that if anything happened i i
gine, all the machinery, protected or otherwise, would be dead,
maybe for months — when he suggested this, the owner told him
that he had ample protection already.
"What could happen. John?" he asked: "how could the en-
gine run away or overspeed when it has the best governor ever in-
vented, and you or your assistant, Charlie, are always in the
engine room?"
It's hard work for some men to beat the boss in an argument,
and many a good suggestion for betterment, or safety, has been
lost because of lack of self-confidence — of being too timid to "talk
up" to the management.
So, the subject was dropped, after the owni r of the factors had.
as he thought, beaten some reason into the engineer's thick head.
Then came the day when the stage was set for a first class acci-
dent. All the conditions were perfect. The machinery I
working like clockwork; not a hitch anywhere, and the owner re-
called, with a smile, the engineer's preposterous attempt to have
him safeguard the engine — the engim thai cosl so much and
workeil so beautifully. John was on the third floor making some
small repairs, directly over the engine room. Charlie, his I ;
I nit, it in the old cane chair, sleepily watching the twinkling
or as they swung after each other.
Suddenly, Charlie sat up with a jerk. The shining balls had
ceased to swing and lay quiet beside the stem. But the engine
was running— yes, but at what a speed: Frightened. Charlie
was fascinated — lost his head, and rushed to the telephone to sum-
mon help. Before he could get the operator, a new noise caused
him to drop the receiver and run for the open door. The big
wheel was turning like lightning and the beautiful new engine was
tugging as if it would rise from the concrete. Nobody but a mad-
man would go near the throttle now. and Charlie was not quite
a lunatic yet. Bursting into the office, he yelled "Something is
wrong. Where's John?" but before the startled owner could
reply, a horrible grinding noise was heard in the direction of the
engine room, and the walls of the building vibrated to a shock
that almost shook the men off their feet.
The flywheel had let go. Tearing their way upward and out-
ward, through floors, heavy beams, shafting and machinery, frag-
ments of the wheel were discharged as if propelled by guncotton.
Pieces fell over a hundred yards away, demolishing everything in
their path.
With pale faces and trembling chins, the two men moved cau-
tiously to the place where the engine room used to be. Nothing
could be seen because of the dense cloud of steam that roared
through the broken main, but when the subsiding pressure al-
lowed the vapor to escape through the torn roof, the owner and
assistant engineer saw and understood.
"Go and find John:" said the owner. A few minutes later
Charlie returned. Hi- soiled handkerchief was pressed to his
eyes. The men looked at each other.
"Did you find him?" a ked the owner.
"Yes," said Charlie, in a choking voice — "Poor Jack:"
Sentiment and business are not good bedfellows, and it was not
long before the owner began reconstruction. The advice of the
dead engineer was recalled in bitterness of spirit. The financial
hi avy, the plant being closed for nearly three months for
repairs and installing a new engine and transmission, including a
fine new flywheel, bigger than the old one.
Visitors to the new power plant saw something not on the old
engine which excited considerable curiosity. This was a modern,
automatic engine stop, provided with connections which en-
abled the engirt ii r! Innn convenient station-, located
anywhere in the factory. It wis arranged also to stop the engine
automatically if there was'any advance of speed over a prescribed
maximum. Furthermore, it could be operated electrically, and one
method of operation did not interfere in the least with the others.
There will never be a flywheel i xplosion in that plant again — at
least so long as the engine -top stays on the main where the ill-
fated John often wished to see it The new man stops his engine
twice daily by pressing a button, and takes pleasure in telling visi-
tor- how, when a breaking -halt once threw all the load off and
the engine began to race, the engine stop lever clicked quietly
once, and the steam was shut off instantly.
No engineer can tell when, or why, or how much his engine will
race under certain emergencies. Governors of the usual type arc-
probably no more reliable than the engine itself They are auxi-
liary safeguards, subject to their own peculiar derangements.
Belts will slip and gears will clog unexpectedly, and once an engine-
begins to race there is only one thing to do — shut off the steam.
If the engineer has nerve and happens to be there, he will close
the throttle, unless the flywheel lets go first. A reliable engine-
stop attends to that matter whether the engineer is asleep in his
bed or talking politics to the fireman in the boiler room.
(By J. St. C. McQuUkin)
...
im) we 1;
Vol. 11. No.
'©W<
gnmi(
'Flume
SYNOPSIS— A small power plant embracing in-
teresting features of design. The arrangement
and equipment are such that the plant is easily
and economically operated and provision is made
for obtaining daily records of performance.
The ground plot on which the power plant ol the
American Engineering Co.. Philadelphia. Penn., is built,
is bounded on three side- by city streets. This placed a
jm<
The generating capacity of the plant is 540 kw.. or
73' hp., made up of one 13 and 22 by 18-in. tandeni-com-
pound engine directly connected to a 150-kw., 250
volt, direct-currenl generator; two 13 and 23 l>\ L6-
in. tandem-compound engines, each directly connected to
a L65-kw., 240-volt, direct-current generator; and one
l'.'x 12-in. single engine directly connected to a 60-kw.,
110-volt, direct-currenl generator. Figs. 1 and 2 show the
engine room.
In addition to the foregoing, the engine room con-
Fig. I. One m the Main Engines and Generators
in the I'<n\ ee Plant
restriction which was further complicated by the inter-
secting streets not being at right angles t e another.
The requirements were sufficient engine and boiler ca-
pacity, together with all auxiliaries and coal- and ash-
storage capacity, and so arranging all the equipment that
operation would be easy, convenient and economical.
Since one of the three streets contained a railroad sid-
The boiler ro
Fig. 3. Se< no>! o\ Li n i; .1.1 of Fig.
ing, it \\a> important to bave the coal-bunker and coal-
bandling system convenient to the siding and also to pro-
vide space tor a private siding for unloading coal.
Fig. 2. The Small Unit and Steam End of a Com-
pound Engine
tains the forced-draft equipment for the stokers, consist-
ing of one steel-plate blower directly connected to either
of two 5x5-in. vertical engines. All of the engines run non-
condensing, the exhaust steam being used for heating the
boiler feed water and also for heating the shops and
offices.
m has three cross-drum water-tube boil-
ers, each having 1500 sq.ft. of heating
surface and is equipped with a gravity
under-feed stoker. There are also two
(i and 1 by 6-in. outside-packed du-
plex feed pumps, two feed-water heat-
ers ami a V-notch recording water
meter ( Fig. I ).
The plan of the power house (Fig.
8) shows the location of the equipmenl
and railroad switch, and Fig. •'! shows
a sectional elevation through the en-
gine room, boiler room and coal hunk-
ers. 'Idie compactness of this arrange-
ment is such that there is practically
no waste space, the equipment is not
crowded and (here is plenty of room to
make the repairs and adjustments.
The combined layout of boilers,
stokers, ashpit, coal bunkers, ash hoisl
and firing Boor is interesting. The
lower holler i'ooh; is practically on the street level, with
the boilers and stokers so set that the lower Boor is also
the level at which ashes are removed from the pits.
January 1".'. L915
I'll \\ I. B
39
Fig. 4. Feed-Water Heatebs and V-Notch Recobdeb
Tin- upper or firing level is flush with the top of the
stoker coal hoppers and is also level with the bottom
of the coal bunker. The firing floor extends from the
boiler fronts to the coal bunker. In the other direction.
the floor is only the width of the boilers, a narrow pass-
ay connecting the firing floor of the battery of two
boilers to the firing floor of the boiler set singly.
Platform scales are built into the firing floor in front
of the coal bunker-. The coal is wheeled from the hunker
to the stoker boppers, each wheelbarrow of coal being
weighed and then dumped into the stoker hoppers.
Fig. 6. Rei obding Instruments in Engineer's Offk e
Pigs. 5 and ; arc views of thi m from above
and below the firing floor. Slack coal is usually used and
is dumped from the car through a cast-iron grating into
a bucket conveyor which deposits it in the bunker. Any
lumps which will not pass through the grating are broken
through, making a crusher unnecessary.
Tin- ash is wheeled to a conveyor on the -.mie level as
the ashpits and tin n elevated to a bunker .1 thai
Li k can back under it and the ash can be discharged
for final removal.
A chief engineer, an oiler and a stoker operator coii-
Fig. o. Stokers below Charging Platform
Fig. 7. Charging Platform, Stokers Below
10
1'iiWE E
Vol. 11, Ni
-ntuto the operating force. The stoker operator tends
the water, weighs the coal and removes the ashes.
The boiler gage glasses are in plain view from either
tin- firing floor or ashpit level, ami tin1 feed valves are
controlled from either floor, thereby making it unneces-
sary fur the operator to make trips from one to the othei
level to regulate the water. The rate of coal feed-
ing and the air pressure required for burning
it are controlled automatically in ae-
cordance with the demands for steam.
therefore the fireman is not re-
quired to continually watch the steam
nor regulate
Fio. s. Plan of Powek Plant
The stoker hoppers are of sufficient capacity to give
the operator ample time to remove the ashes without gi\
ing them any further attention. The plant is so coin-
pact anil conveniently operated that two men could easily
run it. However, since the cost of fuel is the main item
of expense in any power house, it was deemed advisable to
use an extra man, thereby giving the chief engineer
time in the boiler room to see that the maximum fuel
economy is maintained.
Xo. :! boiler is equipped with an independent feed
pump, weighing tanks, fan equipment and a set of re-
ate information on conditions and assisting in maintain-
ing li igh economy.
The instruments, mounted on a panel (Fig. 6), are a
steam-pressure gage, feed-water thermometer, air-pres-
sure gage, differential draft gage, and
due temperature thermometers and all
the recording instruments. There are
also a -ti'am-tlou meter and a recording
C02 meter. They cover all conditions
subjei t to variation and show graphic-
ally the relations of one to the other.
All instruments are checked periodic-
ally.
In addition to tin1 electrical load,
which includes five electric traveling
cranes and a fan for the foundry cu-
pola, -team i- used to drive an air com-
pressor in the shops, for the steam ham-
mers in the forge shop and for tesl pur-
poses 'in the engine-test floor. From
the character of the load it can readily
he seen that the load has wide
limn-.
Tin -team pressure is automatically
held practically constant at l<iO lb. The
stokers are driven from the fan shaft.
and a damper regulator, connected into
the main steam header, controls the
speed of the forced-draft fan. The regu-
lator operates on about two pounds' va-
riation in steam pressure. In varying
the speeil of the fan. the air pi
and the rate of coal feed are controlled
simultaneously. Once the correct ra-
tio "I air supply to the coal feed is ob-
further hand adjustments are necessary.
tained,
B3ew G@2im-p<n>siftH®E& V-slx^e OasM.
A oew composition disk lor steam service has been per-
il, ted by Jenkins Km.-., so White St., New York City, and
will hereafter lie used in all of the company's standard
pattern globe, angle, cross and radiator valves.
The disk will he known as Xo. 119. The composi-
tion is hard, but becomes tough and flexible in service
when under steam pressure. It shows freedom from
PRINCIPAL EQUIPMENT OF AMERICAN ENGINEERING CO.'S POWER PLANT
\,.
Size
225 ,
245 l
245 i
245 i
Maker
Harrisburg Foundry & Mch. Co.
Fitchburgh Steam
Harrisburg Foundry A- Mch. Co.
Operating Condi
, L60 11'. steam.
am..
L60 lb steam
, no volts
. 2111 \.,lls
Triumph Elect
i , 160 11' steam. B F. Son .
i B F. Sturtevam ( !o
:il Electric Co.
Equipment Kind
1 Engine. Simple 12xl2-in Main unit
1 Engine. Compound.. 13x22xl8-in. .. Main unit
2 Engines. Compound.. 13x23xl6-in. . . Main unit
t Generator... Direct current. . 60 kw Main unit
1 Generator.... Direct current. . 150 kw Main unit
2 Generators.. Direct current 165 kw. . Main unit
2 Engines. Vertical 5x5-in Fan drive Variable speed to 446
1 Fan Forced draft Variable speed to 446
3 Boilers Water tube 15O0sei.it heat- Main generators, one
ing surface, experimental.. 160 lb. steam, forced draft Babcock & Wilcox Co.
each .
3 Stokers Taylor Boiler furnace Chain driven, automatic regulated unencan Engineering Co
■ ichrane V-notCh Feed water Continuous Harrison Sail
1 Heater . Vacuum Feedwater.. Exhaust steam Warren Web
2 Pumps Duplex 6x4x6 Boiler feeders . 160 lb. steam, one reserve. Henry R. Worthugton
1 Recorder COs Flue gas Recording continuously John A. Hays
1 Recorder Draft. Stack draft Recording continuously — John A. Hi
Steam flow. . . St. 'am supply
Boiler Works
cording instruments for recording simultaneously all
varying conditions throughout the boiler and furnace.
Thus, experimental and test work can be carried on with-
out interfering with the normal operation of the plant.
These instruments are connected to he used mi an\ oi
the three boiler-, thus affording the chief engineer accur
Recording . General Electric Co.
cracking and flaking and is durable with steam pressures
up to L50 lb.
Tin- Volume oi \ir Dandled by a fan is proportional to the
speed, mid Hi. power required to drive tie [an \. s :is the
cube of the speed That is, to double the amount of air will
require eight times the horsepower.
Januan 12, I - ' L -j
I'd \v e l;
pelo^is^s' MtuLimiops^l OgIhitlnin\g Plsunitt
SYNOPSIS — The following is taken from a * <>>><-
munication from A. C. Jones, superintendent of
municipal light and water plant of Opelousas,
La., and recites wmt of the struggles of a small
plant in a town of about ~<i">i> inhabitants. Due
In the comparatively high price of coal, and the
conditions an oil-i mi appears to have
shown considerable saving over the former steam
plant.
The electric-light and water-works plain was installed
\<\ this city in 189?, and consisted oi on< LlO-hp. center-
crank steam engine, two return-tubular boilers, one 50-kw.
alternator, and one tO-liglit arc machine. There
also two water-works pumps each of 500-gal. capacity.
This equipment was kept in a number of years
a first-class outfit, bul the results much better
than with the old plant.
By the early part of 1911 the < i t \ finances had reached
a desperate state, and it seemed that the plant would hav«»
-Imt down. The receipts from electric and watei
serviic were insufficienl to pay the fuel bills, so that it
had become a regular custom to borrow money from the
banks to pay for fuel. The employees bad to go to the
banks and borrow their salaries on their own tioti
at the beginning of the next y< ir the city council would
pa_v these notes, with interest, ou1 of the license funds.
A n>'\\ .iii, council took charge of th affairs
in L 9 12, and reali ing thai radical changes had to be made
in the electric-light and water-works plant, arranged to
increase the ta s rate three mills irs and bor-
rowed $6000 on it. With tin- money there was pun h
an oil-engine plant consisting of a 100-hp. Mietz & Weiss
Engine Room of the Opelousas Plant
and another alternator and engii idded, after
which the an- machine was discarded and alternating in-
closed an- lamps replaced the open arcs. This equipment
gave pood service and the city was able to operate it sat-
isfactorily until about 1909 when fuel started to increase
in price t<> a point that meant serious I"-- unless some-
thing was done to decrease the amount consumed. A
,i- the plant sta rted to lose more than the city could afford,
the management was unable to get enough money to keep
the machinery in repair. Moreover, due to local condi-
tions, the load fell off considerably.
Finally, after spending afxrat $4000 in repairs, a new
.-team plant was recommended and purchased, consisting
of a tandem-compound, four-valve engine direct-connei ted
to a 150-kw. alternator and a B. & W. boiler. This was
engim oj tiected to a Fori Wayne alternator, a
generator panel, a feeder panel, one 500-gal. Lawrence
pump direct-connected to a 35-hp. three-phase motor, and
a 12xl0-in. Ingersoll-Rand air compressor with short belt
drive from a 35-hp. motor. This installation cost a little
over $11,000. Sim,, the management had only $6000, it
was necessary to arrangi to paj out of the money col-
lected from the eleetrii ami water service; this was fixed
h interest.
This firs! unit was put into regular servic< in I'
ni. 1912. A- i1 was ■ Lough to carry the pi a
load, it was necessary to run the steam plant for al
three hours eai h night, imt in spite of this tin- Decembei
report showed a profit of $427.82, and each month since
has shown a profit.
12
I'd WEE
Vol. 11. No. ■:
Some time after this a second oil-engine set of 100-
kv.-a. capacity was pxirchased, together with a 300-gal.
motor-driven pump. Chis installation was completed
Jan. 1. 1914. It cost installed $10,842, Leaving a debt
of $5842 on this part of the plant, which was to be paid
from revenues at the rate of $250 per month with 5 per
cent, interest. The plant is now paying each month $ I 50
with interest, in addition to paying all labor and operating
expenses out of collections I'm- electric and water service.
The city pays the plant $321 per month for street lighting
and water service.
To improve the service the present superintendent
put up 25 lightning arresters and grounded the neutral
on the secondaries. This practically stopped all trouble
due to lightning, which hail previously been a great source
of trouble. In fact, it had been customary after a heavy-
flash of lightning for the operator to go to the telephone
luad is a little nver 100 kw. and the mid-siimnier peak
load alum! 60 kw.
It mighl In.' mentioned that the price of oil in this lo-
cality is from $3.65 to $f per ton and nil $1.10 per bar-
rel, although it has reached as high as $1.55.
"Fire light and often'" is the injunction frequently
given the fireman by the engineer who has made a stud}
of the factors conducive to high boiler efficiency. With
hand tiring, the impediment- to the complete success oJ
(his plan are: First, it entails more work on the part of
the fireman so that he is inclined to lengthen out the in-
tervals or. if he follow- instructions, it reduces his ca-
pacity. Second, the necessarily frequent opening of the
lire-door admits large quantities of excess air, reducing
Fig. 1.
Kincaid Stokeb Hinged n
Front
BOILEK
Fig.
Entiee Stoking Mechanism Swung Free
FROM FlRE-DoOB
and ascertain what damage bad been done, so as to make
repairs before dark, if the storm happened during the
day time.
The water-works system is supplied with water by two
motor-driven centrifugal pumps. The water in the well
is 4"2 ft. from the surface of the ground, so that it i- neces-
sary to use an air lift to pump to the reservoir. This air
is supplied by the motor-driven air compressor.
The electric service i- all metered and the rates are
as follows:
250 kw.-hr. or less per month, 10 cents.
300 kw.-hr. or less per I th, 9 cents.
::r,i> kw.-hr. or less per month, s cents.
All over 350 kw.-hr. per month. 7 cents
There is a minimum charge of 50 cents per month on
1 to 10 lights, ;:, cents mi 10 to 20 lights and $1 on all
over "20 lights. There is practically no motor load con-
nected except in summer for driving fans. The December
i lii. n 1 1. \ and tending to offset the advantages otherwise
obtainable.
'l'be Kincaid stoker, illustrated herewith, is designed
to secure the full advantages of frequent firing of -mall
i liarges while excluding the impediments just mentioned.
When small charges are (r<\ rapidly and regularly to the
fire, good combustion is secured with practically any grade
of fuel because the unbalanced fuel-and-air supply is elim-
inated. With hand-firing when fresh fuel is thrown on
the grate, the air supply to the freshly covered portion
of the tire is insufficient. Another difficulty is that with
coal of a clinkering nature, large charges result in large
clinkers. The clinkers are not only difficult to handle,
hut they are i >l i ject iona hie for the more important reason
that they interfere with the uniform distribution of the
air supply, which is indispensable in securing good com-
bustion.
January 12, L915
I'd W E
'Flic stoker under discussion catapults anywhere Er
:i oz. to 2 Hi. of coal per charge al the rate of from
10 to 75 charges per minute, depending upon the re-
quirements of the boiler. The coal is distributed evenlj
■ the area of the fuel bed, as will I videnl from
the following description.
Fig. 1 shows tin- stoker in position. The appar-
is hinged on a frame bolted to the boiler front and
no change in setting or boiler front is required other than
the removal of the fire-door and the attachment of a fire-
door frame. Being hung on hinges, the stoker may be
swung dear, as in Fig. 2, for cleaning, trimming or hand-
. should occasion arise.
Fin. 3. Side and Top Views of Stoker,
Showing Crushing Rolls \\i>
Spreading Plate
Referring to Fig. :;. the coal is fed toward the fur-
Dace in regulated quantities by means of the worms and
crusher rolls A. The crusher rolls make it possible to
use coal of any size from slack to S-in. lumps or even
mixed sizes such as mine-run, etc.
The coal drop- into a rectangular space B in front
of the ram C. The ram is actuated by a steam pis-
ton shown at the right of the hopper in Pig. I. The
worms .1. Fig. 3, work intermittently so that when the
ram i- delivering a blow against the coal in space B,
no coal is being fed forward. When the ram is with-
drawn for the next blow, the same motion actuates the
worm- through a predetermined portion of a revolution.
Thus, the same quantity of coal is fed to the ram for each
successive blow. This quantity may be varied by ehang-
ing the "throw" of the ratchel arm which turns the
worms.
Steam is admitted to one side of the piston which drives
the ram b] i rapidly acting valve in much the
same manner that air is admitted behind the piston of a
pneumatic hammer. The acceleration of the ram i< rapid,
Inn at the em! ..!' the stroke, the piston is cushioned by a
small quantity of -team trapped in the end of the cylinder
so that there is practically no mechanical shock when
bringing the ram to
By menu- of a simple, adjustable throttling mechanism
the pressure of the -team admitted behind the piston may
he successively varied to secure strokes or blows of four
different intensities. Hence, the first or weakest stroke
delivers a charge of coal ovet the first or front quarter
of the fuel bed; the second stroke delivers to the second
quarter, and so on. The spreading of the coal is accom-
plished by means of the nozzle plate D.
The exhaust from the ram cylinder is led to a %x3-
in. rectangular nozzle' at /•'. The events are so timed that
a blast of exhaust -team emerges from F at the instant
that a flying charge of coal reaches the nozzle plate. Con-
sequently, the steam catches, partly carries and a-<ist-
in spreading the coal over tin- various portions of the fuel
bed. Naturally, the intensity of the blasts of exhaust
steam varies directlj with the intensity of the stroke of
the ram. Even spreading of the coal depends upon the
i ontour of tin- nozzle plate 1). which is varied to stiit fur-
uaces of different shapes and proportions.
The fluctuations in the demand on the boiler are ac-
commodated by varying the number of charges of coal
thrown per minute ami by varying the >ize of the individ-
ual charge. The former method is usually employed,
while the latter is resorted to only in cases of extreme va-
riation. This change in speed is accomplished by means
of a small steam pilot piston, the speed of which is con-
trolled by a water dashpot to which it is yoked. The re-
sistance of the water pi-ton is varied by constructing or
enlarging the passage through which the water i< forced
to flow from one end of the cylinder to the other. This
arrangement permits of both hand and automatic con-
trol.
The stoker is manufactured b\ the Kim-aid Stoker Co.,
507 East Pearl St . Cincinnati, Ohio.
TsigEIsilb'iia© <G©2 Tlh<eirinni©sc©pe
The Tagliabue ('*> .. Thermoscope is a new device in this
country, but it was fully described on p. 428 of I
23, 1913, issue of Power, as manufactured by an Eng-
lish company. Now it is being manufactured in this
country by the C. J. Tagliabue Manufacturing Co.
18-88 Thirty-third St.. Brooklyn. X. Y.
This device is Used to indicate the peiv.-nia-c of ( 'd .
in flue gases. It reads directly on a plain scale and re
quires no correction for atmospheric conditions.
First Class Engineer almost burned his eyes out measuring
between two switchboard blocks with a brass-bouiul rule.
>:
Tlionehtlessness — A man working on a live 2300-volt panel
reached as far as he could to lay a blow torch upon the metal
window casing of a reinforced-concrete building. His reach
was a little short and that saved him, but the foreman saw
him and gave him a week to think it over.
a
I'd w b i;
Vol. II. No.
>rs\£il Re^mdliiinij
©mi a Sttirlimi^
liv S. ||. VlALL*
Boi!
SYNOPSIS — Deals with the importance of taking
readings at different points in a setting and
how they may be analyzed and compared with
those (nun a standard setting.
On boilers having natural draft, the reports of man)
tests give the draft intensity al the stack side of the
damper or at some point in the breeching, but thej do nol
mention the available draft ovei the lire. \\ itli open ash-
pit hand-fired boilers it is the difference in pressure be-
tween the boiler room and the furnace that tends to cause
air to pass through the fuel and governs the rate of com-
bustion and in turn tlie capacity of the boiler. Other
information is nccessan besides tin draft a1 ome point in
the breeching. The arrangement id' the baffling, the accu-
mulation el tine dust or <>ther factors that affect the -i e
and shape of Lias passages all have a bearing on tin
coal-burning capacity of the unit.
In the article, "Draft Loss through Boilers" (Power,
dune 2), valuable information on the average loss of
draft intensity through different types of boiler is given.
It is common to find power houses operating at capacities
lower than would be available if intelligent attention
were given to the draft conditions. In some plants more
boilers are used than should be required, while in other
plants trouble is experienced in maintaining the steam
pressure.
The writer will briefly describe the work done at a cer-
tain plant and show how the information given in the
article referred to ran be used to advantage in analyzing
conditions in other plants.
Pig. 1 illustrate- the points at which draft readings
haw been taken in Stirling boilers operating on natural
draft and giving satisfactory service as to capacity and
efficiency. The average of these reading- reduced to a
percentage of the draft at the stack side o1 the damper.
considered as LOO per cent., is shown h\ curve No. 1 of
TABLE 1 — PERCENTAGE OP DRAFT AVAILABLE
OUGH STIRLING BOILER 1 'ER CENT AT .1
!ui A B C D ! c G
1 4 33 41 19 6i 93 LOO
I 97 1UU
3 ... i 61 :; so iou
4 4 25 IS ■'
5 .... 4 24 36 43 57 66 100
Fig. 3, and i he data are given in Table 1. This curve
I I- i lo-el\ to the data given for the standard
Stirling boiler, Pig. L8, on page 769 of the dune 2
issue.
Pig. 2 illustrates the boiler setting at a plant which
was having difficult} in generating sufficient steam to
carry the load. It was known that the boiler was no1
overloaded and that it was clean both inside and out.
The truth was that the furnace could not hum enough
coal. Draft readings were taken at the points indicated.
The connection between the boilet and breeching was as
shown. An opening was drilled through the steel breech-
ing eonnei tion between the damper and the boiler at the
point (>. Although this point is on the boiler side of
! impcr. while in Pig. I tl ■■ poinl is on
•Assistant ohiel of Smoke Inspection Department, City of
htcago
the -lack -ide. the two locations are comparable on ac-
count of the loss in Fig. 2, due to a turn in the gas
pass between F and G and also to the loss in taking the
gases downward in the breeching. The first sets of draft
Fig. l.
readings taken on the setting. Fig. '.'. are given by curve
Xo. 2 ami in Table t.
The loss in draft from one point of reading to another
is shown more clearly by the curves than in the tables.
By referring to Fig. '■). it will he observed that there i-
a considerable drop between points F and K. curve Xo. •?.
as compared with the drop between corresponding points
on curve Xo. l ; the latter is the curve for average condi-
tions. Investigation a- to the cause of this drop showed
that the passage for the gases between the rear drum and
the top of the battle on the rear tube- was only f 0 in. high.
Tile was removed from the rear bank of tubes down to a
level with the shelf at the breeching connection. This
increased the opening from the drum to the shelf to 9 ft.
I Irdinarily tin- opening would be considered e» essive, but
a- the breeching connection was a downtake of odd de-
sign to a tunnel below the floor, and as. after the change,
the average temperature of the gases at (1 was <>nl\ ID
<\v^. higher, and this with a higher rate of combustion,
it is apparent that the action taken was warranted.
A second set of draft readings was taken and appears
in curve Xo. :'.. It will he noticed that the available draft
over the fie i greater than in curve No. 2. The loss from
<! to /•' is greater, hut the loss from /■' to E is small. The
curve is approximately normal to point C. but the drop
between C and /; is excessive. It will he observed thai
the percentage of draft available at ( '. curve Xo. 3, is
more than the percentage available for the corresponding
point on the normal curve, Xo. 1. while at point /.'. on
curve Xo. .".. there is less draft available than lor the
corresponding point on curve Xo. I. This -how- clearly
thai the restriction between these two point- is greater
than the average.
Further investigation showed that the baffle at the rear
,,f the ti'oni bank of tubes was elose to the front drum,
January 12, 1915
POW E E
also that the Stirling arch extended to within 1 in. of the
front tubes. The gas passage between the drum and front
baffle was enlarged and about 9 in. of brick cut from the
arch.
A third se1 of draft readings was then taken, and the
results are shown in curve No. I. It is shown thai the
available drafl over the fire is higher than in curve No.
3, also that the drop from G to /•' has increased. Likewise,
drop throughout the rest of the boiler has shown a
t increase except at the points on the fire side of the
enlarged openings. The increase in draft I"— between G
:\iu] F of curves Nos. 3 and I. as compared with curve
No. ".. i- due to the presence of a greater volume of gas
per nun of time mi accounl of increased coal consumption
quari fool of grate. More fuel was burned by the
additional air supplied to the furnace.
The drop in draft intensity from 0 to /> on curve No. '■'>
i- greater than on curve No. 2. The o
these two points were of sufficient area when handling
i he gases produced at the lower rate of combustion. When
this was increased tin- volume of gas was greater and the
area- between C ami B proved to In- ton small,
the conditions shown by curve No. I "ere established,
there was no further change made in the baffling, be-
cause the available draft was sufficient i" produce the
capacii rj to carrj the load. In other words,
satisfactory commercial conditions hail 1 n provided ami
in the estimation of the managemenl anj bei
realized by further work would not justify the extra
labor.
Curve X". 5 is plotted from a sel of drafl readings
taken at a later date than those of curve No. I. hut with
boiler ami furnace conditions as nearly the same a- it was
possible to reproduce them in the ordinary operation of
tin- plant. This curve shows that draft conditions vary
Fn.. '.'.
time to time, although readings from the same plant
under similar conditions will in a general way check
i-lo-eh.
The draft rea en for curves Nos. 2 to 5, in-
clusive, are not merely one - lings, hut are the
observations. For <-\;i
of readings would be made as quickly as possible
at the different points indicated. At intervals this work
would he repeated until then- were six or eighl such sets
of observations. These data were then averaged and the
■ ; tabulated for record.
It is possible from what has been said for one to as-
sume that all the baffling should he taken from the boiler,
thereby increasing the draft intensity in the furnace to
a maximum. It is true that such action might increase
the fuel-burning capacity of the furnace to the utmost,
ioo
90
B 70
'I 60
<
| 50
o
*- 40
30
l./j
S / ■
/
O
/ >/
' i
/
'
in/
>
>V
- -
S
'
/
y
/
/
i
i
J
^V
/
/
1
h-
/
■
/
! 1
/
/
A
'' / y
//»
/
fry
V
E F G
BCD
Points of Redding
Fig. 3.
but the boiler efficiency would be low. The purpose of
the baffling is to cause the heated gases to traverse the
surface in such a manner as to give maximum
efficiency of heat transfer. It must be borne in mind.
though, that any one item in the operation of boilers
can he carried to an extreme. Capacity and efficiency must
be considered with relation to cost of installation, attend-
ance, repairs, flexibility, etc. It has been found that the
available draft through the - fling boiler with
a fire 6 to ^ in. thick, using Middle Western coal with
natural draft and giving satisfactory commercial returns,
should be about as given in curve No. 1.
The course the writer usually pursues in analyzing
draft condil a boiler is about as follows: Make
several sets of ob of draft at the various points
through the boili r. For this purpose use a draft gage
constructed so that it can In- read easily and accurately
to hundredths of an inch. Find the average reading for
each point as in Table ''.. Consider the reading at the
TABLE 2— DRAFT INTENSITY THROUGH STIRLIXc; SET-
TING IX HUNDREDTHS "l'' AX INCH WATER GAGE
No. ot Curve A B C D E F G Date of Readiner
2 ..2 S 14 21 29 58 GO Oct. 13, 1910
3 . .. 2 12 34 4ii 51 53 66 Oct. 20, 1»10
4 2.5 16 25 31 31' 4.". 65 Oct. 24, 1910
5 2.5 IT 25 31' 40 46 70 Oct. 2S, 1910
stack side ni tin- damper as too per cent. Calculate the
ratios between the readings at the various points and at
point G. Express these ratios in percentages as in Table
d construct curves similar to those shown in F
For convenience of study, it may he advisable to make
each curve a different color. Compare the curves thus
found with the normal curve for the type of boiler under
consideration. Draft troubles may then fie quite easily
corrected because quickly located.
I',
POWE K
'©Hue Transformer C
Vol. 41, No. 2
By Gordon Fox
SYNOPSIS — How to determine the polarity oj a
transformer, connect it properly, and obtain the
d voltage combinations.
When two alternating-current circuits are to operate
in parallel they must be in synchronism, which requires
equality of voltage and frequency and coincidence of
phase. It is not within the province of the stationary
transformer to change frequencies so that only cin nits of
the same frequency can be paralleled. But transformers
do change voltage and ran easily change relative phase
relations, so that where more than a single transformer
is involved it is necessary to exercise considerable rare
to maintain the proper voltage and phase conditions.
Consider the rase of two transformers connected in
open delta as at a in Fig. 1. Here one phase is in a 60-
degree relation to the other and the voltages of the sec-
ondary phases are all equal. Reversing one transformer
secondary, as in b, changes its phase position 180 degrees,
-ii that it now bears a 120-degree relation to the phase of
the other transformer and the three secondary voltages
o longe: equal.
Likewise in a three-phase three-transformer connection
it is an easy matter to connect in one phase reversed; in
fact, more so than with two transformers. For instance,
Pig. 2-a shows three transformers of the same polarity
connected properly in star and the phase relations are in-
dicated. Reversing one of the secondary phases, an easy
mistake, causes the voltage and phase relations to lie en-
tirely changed ; this is shown in Pig. 2-b. Similarly, with
two transformers of one polarity and the third of the op-
posite polarity connected as in Fig. '?-a. the phase rela-
tion of Pig. 2-li would lie obtained.
The term polarity as applied to transformers refers
to the relative location of the primary and secondary
leads. The terms positive and negative polarity have 1 n
empirically chosen to represent the two possible relations
of primary and secondary leads. A transformer is said
to have positivi Laritj if, when ,i primary lead is in-
stantaneously positive, the secondary opposite it in the
i ase is instantaneously negative. Kg. 3-a shows dia-
grammatieally the arrangement ol coils in a transformer
having positive polarity and indicates the relative instan-
! - direi rents in the coils. This will
be more evi onnection with an explanation of
the test to determine polarity.
It is ipiite a simple procedure to test the polarity of a
single-phase transformer. A voltmeter is desirable for
the work hut lamp- can generally be used satisfactorily.
The terminals are conno ted as in Fig. 3-b, one primary
lead being connei ! condary and the terminals .1
and C connected onvenient low-tension, alter-
nating-current line, say, 110 volts. Voltages .1-/.'. .1-''
and I'-T) are then measured or their relative values
determined with a lamp: [f A-C is greatet than A-B. the
determined with a lamp. If A-C \< greater than .1-/.'. the
it ha- negative polarity.
The polarity ^1 transformers being determined, their
relative phase relations must he kepi ion tantly in mind
when connecting them. This |. \)es\ ,|,,,l(. m the case of
single-phase circuits by making a rule to connect all
positive polarity transformers with their leads straight
and negative polarity transformers with their leads
crossed. In the latter case. onl\ one set of leads should
he crossed, of .nurse, preferably the secondaries. For
the sake of uniformity it ts well to adhere to a standard
practice. Pig. I -hows two transformers of positive po-
larity and one of negative polarity banked.
When single-phase transformers are connected on three-
phase systems care must he used to preserve the proper
phase relations. This can most easily he followed through
if for individual cases the relative phase positions of the
transformer windings are indicated on the diagram of
connection. Fig. 5 represents a hank of three single-
pha-e transformers connected in delta-star, showing the
relative positions of the windings. The position of the
primary windings may he arbitrarily selected, the selec-
tion being consistent with the actual physical connection.
The secondary winding phase relations follow at once
from the positions of the primary windings. It is then
necessary only to figure the proper connection of the
secondary to get the desired result.
To follow through the connections in Pig. ."i, first as-
sume that the transformers are all of like polarity: it
really makes no difference whether they be positive or
negative so long as they are all alike. If one transformer
i- of opposite polarity from the others, the same reason-
ing can he followed out and then the secondary of the
differing transformer can be reversed. The primary
three-phase wires are represented by .V. F and Z. Since
the primary is to be delta connected, transformer No. t
■ an hi' connected with its primary leads across any two
of the primary wires: for instance. X and Y. Then the
phase relation of the primary can he arbitrarily shown
as designated a-h. Next connect the primary of trans-
former Xo. 2. These leads may be connected across
either Y-Z or X-Z, the diagram showing the former. The
phase relation is once more arbitrarily selected in such
position that b-c makes a 60-electrieal-degree angle with
b-ii. Next, connect the primaries of transformer No. 3.
This transformer must now he connected between the
wires A" and Z to obtain the delta, the phase relation
being represented by a-c, making GO electrical degrees
with ./-/j ami the same with c-b.
In making the secondary connections, it will be best
to lay out the transformer-phase relations first and make
the terminal connections to correspond. For a star con-
nection such as desired, there must be 120 electrical de-
grees between phases. Lay off e-f parallel to a-h. This
phase makes an angle ol 60 degrees with the horizontal
and 30 degrees with the vertical. In transformer No. 2.
e-g makes a 60-degree angle with the horizontal and a 30-
degree angle with the vertical. By placing the point- i -
to coincide, the desired relation is obtained between the
phases of these first two transformers, namely. 120
\e\t. consider transformer Xo. •'!. This phase, graphic-
ally represented, must extend horizontally to the left.
dl do so if lettered as shown. Since the points
form the -tar in 'he diagram they will do so in th
January 12, 1915
]'() W E tt
tual connection. The leads F-G-1I are the three-phase
wires for the secondary circuit.
In a similar manner, a delta to delta, star to star, or
star i" delta connection can be laid out and connected.
A little study in laying out the diagram will save time
and trouble and will assure a correct connection a1 the
first trial.
Xot infrequently it is desired, For testing or other pur-
poses, to secure a voltage other than standard. Figs. 6,
', and S show three arrangements of single-phase trans-
formers which may be used in emergencies or for special
purposes. Fig. 6 shows an auto-transformer connection
For securing a 10 percent, boosl in the hue voltage. Fig.
" is a step-down arrangement providing a higher sec-
ondary voltage than that resulting from the ordinary
original ratio was 5 to I and the primary voltage re-
mained the same.
Fig. 8 is an arrangement utilizing two transformers
with the primaries in parallel and secondaries in
to give double the rated voltage of the transformei e
ondaries. An arrangement of this sort could he easily
made to utilize transformers on hand in a plant where
an increase in roltage is desired.
Sometime- in connection with three-phase work it is
desirable to obtain a range of voltage. This can be done
within certain limits by manipulating the connections.
With a given primary connei tion the secondary star con-
nection provides 1.73 times the voltage from the delta
connection. By changing both primary and secondary
for both arrangements and utilizing various combina-
Prrmary _
(a) FI6.I. (b)
J
(a) FIG.2 (b)
l-w\
-
- -
ra
'-~r"j
.;-.v-..-
,b. - Sa
Various Transformer Combinations
transformer connection. In this case half the secondary
is connected bucking the primary, thus reducing thi ef
fective primary turns and decreasing the ratio of trans-
formation proportionately. The capacity of the trans-
former is cut nearly in two since only half the secondary
i- available to carry secondary load. In the case cited,
with a ratio of transformation of 5 to 1. the voltage
across one-half the secondary would be 110 with the usual
connections; whereas, with the connections shown, it
would be 122. Where the ratio of transformation i- high,
the difference would be small. A connection similar to
that of Pig. 7, in which half the secondary is made to
boost the number of effective primary turns, would
change the transformation ratio so that a voltage of 100
would result in the other secondary coil, providing the
Star
Open -1. Ita
2300
66
.ir 1 1
Star
Star
2300
1 L5
Star
li. -Id
2300
133
Delta
Star
2300
I'd
Delta
Delta
2300
230
Delta
Star
2300
tions, quite a flexible ami broad voltage range is attain-
able.
Assume three single-phase transformers with 2300-
volt primary windings and 115-230-volt secondaries. The
table shows the number of available three-phase second-
ary voltages which can he secured by different connec-
tions. If the transformers are provided with 10 per
TABLE i H'" TRANSFORMER CONNECTIONS
I'li- Second-
Primary Secondary mary ary
Connection Connection Volts Volts Remarks
Using middle taps of
two transformers.
Using all middle taps.
Outside terminals.
Usiner all middle taps.
i terminals.
Outside terminals.
cent, taps, as most standard transformers now are, the
range can In- si ill further enhanced. With such a num-
ber of connections il may appear difficult to make the
necessary changes. Fig. '■> shows a switch arranged to
make it possible in change easily from star to delta and
rirr versa. A little study will make the connection plain.
By providing such a switch in both primary and second-
ary circuit.-- the changes can he quickly made.
One ease in which an arrangement of this kind some-
times proves useful is to provide reduced starting volt-
ages for motors. Df then- he hut a single large motor
fed from a transformer hank, it may be feasible to do
away with an expensive compensator by simply connect-
ing the transformer secondaries in delta at starting and
then throwing over to star for running. The ratio of
torques compares with the lowest point on ordinary
48
TOW ETC
Vol.
No. 2
pensators. This arrangement is not suitable where more
than one motor is involved. Another arrangement which
can be used for a number of motors is shown in Fig. 10.
This is merely an open delta in which the 50 per cent,
taps are used to secure the lower starting voltage. Since
the starting torque of motors at 50 per cent voltage is
low, this arrangement cannot be used where heavy start-
in- duty is required. The additional wiring may prohibit
its use for an extensive system, but in not infrequent cases
it can be, and is. used to advantage.
ILsicfe. ©if Syiraclhipoimnsmm aim Clh©c!fe~
I'.v S. F. Jeter
In the changes in the Massachusetts boiler rules, as
given in the issue of Sept. 15, p. 395, under Section -2,
paragraph 25, it is proposed to require a separate check
valve on the return pipe to each boiler instead of one check
valve on the main return pipe, as is now the rule.
Such a change would certainly be a step in the wrong
direction, for it has been amply demonstrated in practice
that check valves arranged in parallel cannot be expected
to act in synchronism under small differences in pres-
sure. The failure of these valves to act in unison is due
to a tendency to hind and a slight difference in the weight
of the valves where thev are of the same size; but chiefly
J3 (*^~£~p»
jji^ki ~T--: -miBo-tor
Fig. l. The Original Installation
due to the differences in area exposed to pressure on the
two sides of the valve produced by the difference in the
amount of seated area in valves of the same size. In the
case of valves of different sizes the difference in the ratio
between the seated and the effective area under the valve
causes the failure of such valves to act in unison. I re-
eentlv observed a case of trouble resulting from this cause,
which aptly illustrates the difficulties that may be ex-
pected if this change H made in the rules.
An establishment which required heated platens for
a series of presses had an automatic gas-fired boiler to
furnish the steam during th< summer months in place of
the larger boiler. The original arrangement was as shown
in Fig. 1. where the normal water line in the boiler wis
about six to eight inches above the steam spaces in the
presses. It was advised that there should be installed a
pump or some form of lifting trap (since it was imprac-
tical to lower the boiler) in order to get steam into the
platens of the presses, as was required. A tilting trap
was installed (Fig. 2), but the apparatus failed to operate
properly. The trouble was that the water line in the
hoiler would drop rapidly ami 'jet entirely out of sight in
the glass, which would necessitate dosing down, as the
boiler's water capacity was limited. Any tendency of the
water stopping at any point in the system would lower the
water line to a dangerous point.
It was decided that the check valves on the returns did
not act in unison and that water collected in one or more
of the platens due lo the failure of the check valves to
open. The separate return pipes were replaced with a
single pipe and check (Fig. :>) and the trouble was re-
moved. Tin' distan.e from the bottoms of the platens to
the level of the return pipes where the check valves were
Tilting Trap
Gas Fired Boiler
Fig. 2. First Connection to Trap
located was about fourteen inches, which clearly demon-
-t rated that these particular check valves, which were all
of the same size and make and were purchased at the same
time, could not he relied on to work nearly enough in uni-
son to prevent a change in water level of fourteen inches.
\'o water could begin to collect in the platens until this
difference of level was maintained by one or more of the
check valves failing to operate under this head.
Differences of water level considerably less than the
above would he dangerous in many kinds of heating boil-
Tiltmg Trap
d^j^ Gas Fired Boiler
Fig. •'>. Fin-al Arrangement
ers. Of course, with a single check valve Eor several boilers
there is the risk that the attendant may close the steam
valve on a boiler without closing the stop valve on the in-
dividual return pipe to the same boiler, but that danger is
less than the danger from the condition mentioned. A
tetter arrangement than either would he to have the re-
turn connections located at or above the lowest safe-water
line, as was suggested in the issue of July 88, p. 133.
January 155, 1915
P 0 W E P.
l:i
Poorer Pl&imtt
Bi (». C. Thomae
SYNOPSIS — Tin chan oal-iron manufacturing
filniil of lltf Standard Iron Co., Ltd., is mi mi in-
let of Georgian Bay, nl Perry Sound, <>nl. The
power house is of interest in possessing a turbo-
blower and in IIh variety of purposes In which
steam turbines have been applied. Although fur-
nace gas was available, the convenience of gas-
fired boilers and the direct rotary drive n[ steam
turbines, together with ease <>f starting up. made
turbines preferable In gas engines.
The steam generators of tins plant, Fig. 1, consist of
three flush-front, horizontal return-tubular boilers hav-
ing furnaces designed for either coal or blast-furnace
pulse steam turbine, taking saturated steam at a boiler
pressure of L50 lb. ami exhausting into a Low-level je1
condenser at 28-in. vacuum, referred to 30-in. barometer.
The steam consumption is L3.9 lb. per brake-horsepower-
hour. Noncondensing working is provided For by a 10-in.
"Multiflex" atmospheric relief valve ami a gate valve for
isolating the c lenser. A steam separator is placed
between the turbine and the lowest point in the main
steam header. The overall dimensions of the turbo-
blower are •*> ft. and 15 ft. by 6 ft. 3 in. in height from
the bottom nl the bedplate.
For driving tin' removal pump nl' the jet condenser, a
14-hp. steam turbine is used, running .it ls:>o r.p.m. The
condenser is placed in a basement below the turbine i"
facilitate tin- iln« of injection water. The vacuum is
Pig. 1. Turbine-Driven Blower, Generator and Condenser Water-Kemoval Pump
gas. Each boiler is rated at 200 hp. and has 2000 sq.ft.
of heating surface; the shell dimensions arc is in. diam-
eter by 20 ft. long. The boilers are designed for a work-
ing pressure of 150 lb., in accordance with the Massachu-
setts boiler rules. The products of combustion are dis-
charged into a 5-ft. diameter, 125-ft. guyed stack.
Steam Turbo-Blower
For supplying air blast to the furnace a turbine-driven
blower is employed with a capacity of 12,000 cu.-
ft. of \'r(X' air per min. delivered at from (i to 8 lb.
per square inch and running at 1000 r.p.m. All bear-
ings are fitted with forced lubrication, oil being delivered
from a gear pump driven from the main shaft and cir-
culated through an nil cooler and Biter before being re-
turned to the bearings.
Air is taken in through a ] j-in. mesh wire-gauze screen
and filter outside the building ami carried in a duct under
the turbine-room floor ti> the blower. There are non-
return ami relief valves in the air main t • ■ the furnace.
The turbine end of the blowing unit consists of an ini-
maintained by an engine-driven
the left nf Fig. I.
Electrical
d ry-a ir pump, shown at
\n Pumping Equipment
Other apparatus in the power house includes a FO-kw.
turbo-generatoT fur lighting and power purposes,' one
5- and one 8-in. turbine-driven centrifugal pump, two
duplex outside-packed boiler-feed pumps, and a closed
feed-water heater, through which the auxiliary units ex-
haust their steam. The 10-kw. direct-current generator
runs at 2800 r.p.m.. being driven by a noncondensing
steam turbine taking 37% lb. of -team per brake-horse-
power. The .">- and 8-in. centrifugal pumps driven by
turbines are for general service ami deliver cooling water
to the furnace.
The 40-hp. turbine driving the 5-in. pump takes 1500
lb. of steam per hour noncondensing. These pumps, to-
gether with the condenser, draw their water from a 14-
in. suction main running from the bay, 356 ft. from the
house. The lake-water level is 15 ft. 0 in. below
the centrifugal-pump centers and ','■'. ft. below the condeii-
50
l'n W EK
Vol. 11, No. 2
ser-injectioii inlet. The pumps are primed by a steam
ejector.
The two duplex Eeed pumps have normal capacities of
108 gal. per min. each and are situated in the boiler
room; they are arranged to draw water either from the
condenser hotwell or from the main centrifugal pump-
suction line. The feed-pump discharge is led through
the feed-water heater on its way to the boilers, a bypass
cutting out the heater for cleaning, etc.
Steam is conducted from each boiler by a 6-in. branch
and an isolating valve leading into a 6-in. steam main
to the turbine room, where, bj a vertical drop of 11 It..
the pipe passes to the level of-the trenches in the con-
crete floor, through which the branches to the different
units are led. The vertical length of main does away
with any necessity for an expansion bend and facilitates
Fig. 2. Powek House and Piping to Furnace
drainage, which is designed to gravitate toward the steam
separator. Water of condensation is removed by an
automatic steam trap directly attached to the separator.
Although steam piping in trenches is not usually ad-
vantageous, the fact that in this instance all the turbines
are placed above the piping renders remote the chance
of damage by water. The high-pressure main and
branches above 2%-in. in diameter are of extra-heavy,
wrought-steel pipe with screwed-on Ranges. For r? ! --in.
diameter and less, screwed fittings are used.
The blower turbine is connected to the condenser by a
cast-iron exhaust bend and a corrugated copper expan-
sion joint. All the other units exhaust into a galvanized
wrought-steel exhaust main connected t" the Iced heater.
Isolation of the heater is attained by closing a gate valve
next to the heater and opeuing another on the exhaust
main leading to the atmosphere. These valves will also
he used in cold weather to build up a slight back pressure
for exhaust-steam heating. A relief valve is fitted to the
main in a conspicuous position to draw attention to any
undue rise in pressure.
The water coi :tions to the centrifugal pumps and
condenser are of cast-iron flanged pipe with long-radius
elbows, and taper pipes make connections with the pump
branches. The main suction line is of flanged piping, ami
was tested for air leaks to a pressure of 30 lb. pier sq.in.
In addition to a necessary loot valve at the intake,
check valves are placed in the branches to the conden-
ser ami feci] pumps, and there are water-sealed gate
valves in the branches to the centrifugal pumps. The
velocity of water in the suction main under normal
erating conditions i- 280 ft. per min.. and the friction
head loss between the lake and the pumps is estimated at
about 2.7 ft., omitting the resistance of the foot valve.
A solid rock formation immediately below the engine-
room floor made it inexpedient to place the power house
;it a lower level, and prohibited the construction of an
intake flume. The satisfactory working of the present
arrangement shows that any other scheme would have
been an unnecessary expense. The feed piping to the
boilers is extra heavy, similar to the main steam piping,
and each branch to a boiler has the usual stop, check
and feed-regulating valves, the latter arranged at the
front of each boiler at hand level. With two exceptions,
all water ami feed valves are of the straightway type.
The plant was started up and the blast furnace, Fig.
2, '-blown in" on Aug. 21, 1913, and on Aug. 21 the
furnace was tapped and several tons of charcoal pig-iron
drawn oil. The simplicity of operation of this power
plant is worthy of comment. In the first place, the boil-
ers are gas fired and therefore need hut little atten-
tion. The only reciprocating motive power is that driv-
ing the air pump, and it is automatically oiled. As
the rest of the apparatus is steam-turbine driven, tin-
whole plant can be easily operated by one man, and his
duties are practically limited to watching the feed water
and keeping the log book entered up.
The contractors for the equipment were the Eudel-
Belknap Machinery Co.. Ltd., Montreal : the turbines were
supplied and erected by Fraser & Chalmers of Canada,
Ltd., Montreal.
Tiricfcs ©£ tlh© Tirade
By F. TV. Harris
Thompson was a passenger- and freight-elevator sales-
man selling both hydraulic and electric elevators. He not
only sold elevators for new buildings, but he would sell
an electric to replace a hydraulic elevator, giving incon-
trovertible reasons to justify the change. He would also
sell a hydraulic elevator to replace an electric ami give
equally solid data to justify this change. In fact, he was
a true salesman.
lie had been after old John True for a long time to get
him to throw out a '•worthless" hydraulic machine and put
in an electric, and he was spurred on by the fact that he
hail a customer who had a '"worthless" electric elevator
which he planned to replace by a hydraulic.
Thompson found, by spending a little money on cart-
age and erection and furnishing a little additional ma-
terial, that the shift could he made with profit to himself
ami temporary satisfaction to both customers.
Old John operated his hydraulic elevator from the city
water mains and Thompson visited the water bureau.
"I am from True & Sons.'' he stated. "We have mi-
laid our bills for the last two years and I wondered if I
could get a statement of the amounts for these years."
lie found that the bill for two years was $1!».">. Old
John refused to he convinced by his arguments and par-
ticularly scouted the claim of lower cost for the electric.
"You don't know what it costs me to run my elevator."' he
objected : "you are just guessing at it."
"Not exactly guessing, Mr. True. We elevator men
can figure closely. Now, I know the distance you have
lo lift and 1 can give a close estimate of the average load
carried and the number of trips made per day. 1 know
Januan I'.'. 1915
POW E U
51
the water rate in this city and the resl is a mere matter of "Wail a minute until I get the bills."
higher mathematics." The old man went over the file slowly and finally came
Old John looked at him over his glasses and growled: back with two bills which he totaled. Then he looked
"Higher mathematics, eh! And what do you make i1 bj over bis spectacles al Thompson with a new respeel in bis
your higher mathematics?" eyes.
"Well, considering general business conditions during "Say," he said, "you are surely a close figurer. It cost
the last two years, your water bill -In mi hi have been a little exactly $195."
under $200 for the two years; say $195." Whereupon Thompson goi oul his orderbook.
Jm&H Isolated Plsumtt Pays
Davidlemidls
one
liv Thomas Wilson
are ready for the scrap pile at the end of this period and
that others might better be equipped with more efficient
machinery, but in the majority of isolated plants the
time of usefulness and efficiency far exceeds the limit
named. This is particularly true where heating is to be
done. Where there is use for the exhaust steam the en-
gine rate is not of prime importance, for if the supply
From central-station sources it has been frequently of exhaust is curtailed, live steam from the boilers must
stated that the commercial life of a plant should be lim- fill the demand and the total is as high as ever.
ited to fifteen years. There is no doubt that some plants A plant which has been in use for fourteen years in a
SYNOPSIS — This small plant, which is earning
from 17 to 21 per cent, on the original investment
after fourteen years of service, is equipped with
high -sjiri'd cni/inrs ami /nvliciilli/ 'ill of the ex-
haust steam is utilized.
Fig. 1. The Two Return-Tubulai; Boilers. Fig. 2. A View of the Generating Units. Fig. 3. Tandem-
Compound Elevatob Pumps. Fig. 4. Switchboard and Gage Panel
roWEI!
Vol. 11. No. 2
Northern city and is good for as many more is here de-
scribed. The casual observer would think that the plant
is only four or five years old as the engines, pump- and
lave the freshly painted appearance of being
new and are in the best of condition. Besides, an ex-
amination of the records shows that the plant is as effi-
• many of more recent des
The firm does a wholesale hardware business, and
makes harness, awnings, tents and does some forge work.
It has two large frame buildings from two to eight stories
high. In plan, the main building measures 420 ft. mi
Fig. ■">. Type of Boilek .Setting Used
one side, 4-50 ft. on the other and is 100 ft. wide. The
other building is 125x140 ft.
The equipment consists principally of two 72-in. by
20-ft. tubular boilers: two 75-kw. direct-current dynamos,
eaeh driven by Ilxl8xl4-in. tandem-compound engines
running at 270 r.p.m.; one simple llxl2-in. engine driv-
ing a 45-kw. machine at the same speed: two feed pumps,
one a <x4%x8-in. duplex and the other a simplex. 7%j
4y2x9-in. : one duplex 18xl0xl2-in. tire pump; two 12x
4V2xl8-in. tandem-compound duplex elevator pump- and
six hydraulic elevators operated under an oil pressure of
800 lb. in connection with an accumulator. Four of the
elevators are rated at three tons, one at one ton and the
other at 1500 lb. There are also some locomotive-type air
compressors, a 51 (\ t:''4x5-in. duplex house pump, one
8xl2xl2-in. vacuum pump, a feed-water heater and sonii
minor equipment.
The fire-tube boiler.- (Fig. 1 ) are 6 ft. in diameter and
20 ft. long, have seventy 1-in. tube,- and the joints are of
the butt-and-strap type. Under an operating pressure of
125 lb., they have been worked for the fourteen years
with only minor repairs. The water, obtained partly from
driven well- and from a hay. i- of good quality, and
a small amount of compound, costing aboul $25 per year,
has been used to keep the boilers clean. One boiler. :
at times above rating, carries the load except during
coldest weather. Under the boilers are shaking grates
measuring 6x5 ft. To the grate surface of 30 sq.ft., a
heating surface of KjO sq.ft. bear- a ratio of 58 to l.
The breeching is of uniform size. 1 ft. square, and enters
a rectangular brick stack, 7x4 ft. and 110 ft. high. To
the connected grate surface the area of the breeching
bears a ratio of 1 to 3.75 and the stack area a rat'1
proximating 1 to -.'. It i- evident that the cross-sections
of both breeching and -tack are abundantly large, but no
doubt some allowance ha- been made for the higher re-
sistances of square passages.
Scinibituminoi: I is delivered by rail ami
dumped from car- or, a siding into a hopper underneath
the track. It is raised by a chain belt of home manufac-
ture to a bin in front of the boilers and hand-tired outo
the grates. There are two doors to each furnace and the
alternate method of firing is used.
The furnace is of the special design shown in Fig. 5.
It consists first of a hollow bridge-wall with an opening
leading out under the grate. Near the tup and at the
iack of the bridge-wall heated air passes out through a
- of openings to mix with the gases of combustion
and supply sufficient oxygen for the volatile. In the fir-
ing door- there is provision for admitting air over the
[ire: the boilers are operated with the ash doors removed.
Back of the bridge-wall and extending down from the
boiler shell is an arch under which the gases must pass
into a checkerwork of brick piers. The latter maintain
a high temperature in the combustion chamber so that the
. mixed thoroughly in their passage under the arch
and among the pier.-, burn at a high rate of combustion.
Water for the boilers in the heating season comes from
a tank receiving the returns of the heating system. By
means of a ball and float, makeup water is supplied from
the house tank on the seventh floor. Duplex-feed pumps
force the water to the boilers through a vertical closed
heater 30 in. diameter and 1214 ft- high and a single-
pipe economizer in the breeching 2 in. diameter and GO
ft. long. In the heater the temperature of the water
reaches 150 deg. and is raised to 201 by the economizer.
That the latter has been in service nine years and is still
in good condition is attributed to the fact that the water
enters the pipe hot ( 150 deg. at least ). so that there is no
opportunity for sweating aud collecting pasty masses of
soot on the exterior.
Heating is required nine months in the year from the
23,500 sq.ft. of radiation. The smaller building lias a
two-pipe system with a vacuum pump at the end of the
line: the main building has a single-pipe Paul system.
DAILY REPORT OF POWER PLANT
., ,,-. .. SI.,.. .. 11....
- v
j —
-~,
... —
..
c < . ,
Fig. (i. Blank Fokm fob the Daily. Log
Radiators arc used in the office, the temperature being
controlled by thermostats. For six months there is suf-
ficient exhaust steam during the day to do all of the heat-
ing besides supplying a large collar-drying room and rais-
ing the temperature of the water for boiler feed and
use. During the three coldest months some live -team is
k\ 1915
row k i;
53
required, and at night throughout the cold season H is
necessary to draw on the boilers, as the Load is always light
Mini the supply of exhaust steam is limited. 'The conditions
then are unusually favorable. For nine months in the
year, all of the exhaust steam is utilized and during the
remaining three months part of the available supply goes
to the feed-water heater, the drying room and the hot-
water tank.
For ten hours the load averages aboui 650 amp., al-
TABL.E 1. POWER PLANT EXPENSES AND EARNINGS
AT CURRENT RATES FOR L911
Expenses
Coal, J8.45 per ton $4,653.57
Switching and unloading 180.00
Kngine oil used for all purposes 40.00
( 'ylmder oil 86.36
Crease for engines and motors 1 .Of.
Hydraulic oil for elevators 56.52
Waste for engines, elevators and motors 56.52
Engine repa ir 70.81
Hoiler repair 7 .55
I mi --half of chief engineer's salary SOO .00
Second engineer's salary 1,033.75
Two firemen's .salaries 1,678 90
Taint and varnish 6.00
Fixed charges: Interest, 5%; depreciation,
insurance and taxes, l<;„ on plant cost of $30,000. . 3,300.00
Total expenses and charges $11,971.03
Earnings
Current at 3c. per Kw.-Hr. Kw.-Hr.
January 23,423
Fehruarv IS, 950
March 22,710
April 20,097
May • 20,090
June 17,204
July IS, 343
August 20,612
September IS, 327
October 20,823
November 20,427
December 23,423
Total 244,429
Heating; 23,500 sq.ft., at 30c
Six hydraulic elevators, 300 working days, at $7
a day
Water pumped at 2c. per 100 cu.ft
Fire pump maintenance for one year
Live steam to factory
Hot water for house service
$702.69
568.50
681 .30
l'.n2.9l
602.70
516.12
550.29
61S.36
549.81
624.69
612.81
702.69
$7,332.87
7,050.00
2,100. On
504. no
78.00
Total earnings $17,198. 87
Total expenses 11,971.03
For illumination there are, in round numbers, 5000 six-
teen ca ndlepov er lamps.
It has been the custom to run one of the compound-
engine units for I he greater part of the day. From '■'■
t<> ">::;() p.m., during the peak load, and on dark days
the simple engine is used to help out, and after 10 in
the evening il is tin' only engine nrnning.
TABLE 2. POWER PLANT !'\ I 'lONSFJS AND EARNINGS
AT CURRENT RATES FOR 1912
Expenses
Coal, $3.45 per $5,111.43
Switching and unloading 2 1 i 50
Engine oil used for all purposes 52.61
Cylinder oil 83.60
i Irease for engines and elevators 4.20
Waste 35.41
Boiler compound L'5 . 7ll
Boiler repairs, brick setting 95.40
No. 2 engine overhauled 195.60
Other repairs
Pai king for engines and elevators
Paint for engine room
Metal polish
Tools
Half of chief engineer's salarj
Second engineer's ami two Bremen's wages
Fixed charges I rest, 5%; insurance and taxes,
1%; depreciation 5% on plant cost of $30,000
32. 8S
9.29
i'ii. at;
11.72
s.rni
850.00
2,623.77
3,300.00
Total expenses and charges $12,660.87
Earnings
Current at 3c. per Kw.-Hr. Kw.-Hr.
January 28,327
February 25,047
March 25,650
April 24,337
May 25,167
June 22,56:1
July 23,783
August 25,390
September 26,590
October 26,270
November 26,270
December 27,243
751.
769.
730.
755.
676.
713.
761.
797.
7SS.
788.
S17.
Total 306,637 $9,199.11
Heating; 23,500 sq.ft., at 30c
Six hydraulic elevators, 300 working days, at $7
a day
Water pumped for building at 2c. per 100 cu.ft
Fire pump maintenance for year
Live steam to factory
Hot water for house service
7,050.00
2,100.0(1
504.00
78.00
100.00
80.00
Total earnings $19,111.11
Total expenses 12.660.S7
Net earnings $5,227 .
Net earnings $6,450.24
No. Equipment Kind
2 Boilers Fire-tube
2 Furnaces Reekie smoke-
PRINCIPAL EQ1 I I'M I : VI UK I'll I ; ISOLATED PLANT
I se Operating Conditions
< Miii[;ii< -team Natural draft, hand tired. 125 11' y
Maker
Northwestern Boile
.Vft .
1 nder boilers.... .1. I). Reekie
Under boilers.... Heck
Wks
of Duluth
1 Pump. Duplex. . .
I Pump Simplex....
1 Pump Simplex. ...
2 Pumps Tandei i
duplex. . .
I Pump Duplex....
I Pump Duplex..,.
0 Elevators Hydraulic.
30 in. dia., 12J ft.
liigli Heat f I water Exhaust steam, water 150 deg Kewanee Boiler Co,
7xt{xs-in. . It. .iter f 1 water 125 lb, steam Fred M, Prescott Steam
Co.
7$x4$x9-in.. Boiler feed water 125 lb. steam Union Steam Pump Co.
Sxl2xl2-in Vacuum on heating system 125 lb. steam Union Steam Pump Co.
On hydraulic elevators 125 lb. steam
12x4ixl8-i
lSxlOxl2-in Fire..
51x4{x5-in House pump.
Four 3-ton; one
1-ton. one 1500
lb Passenger and freight
Fred M. Prescott Steam Pi
70r.p.m., 1251b. steam, 1000 gal pel l Fairbanks Morse & Co.
125 lb. steam , Gardner Governor Co.
i hi pressure sun II. , 15" it pel i
'Ml- Kle\ , ( 'o.
1 Pump Duplex
1 Air compressor . . Simple, loco-
motive type.
2 Engines Tandem com-
pound,
2 Generators. Direct-current.
1 Kngine Simple
1 Generator Direct-current.
4'x2Jxl-in Oil for elevators. 125 lb. steam Fred M. Prescott, Steam Pump Co.
9x6$x9-in Air chamber of elevator
system Steam 125 11. . air 150 II..
Ilxl8xl4-in Main units... Steam 125 lb., 270 r.p.m.
75-kw Main units. 1 15 v.. Its. 270 r.p.m.
Ilxl2-in. Main unit
45-kw, Main unit
Westinghouse Air Brake Co.
A. L. Ide & Sons
< leneral Electric Co.
A. L. Ide & Sons
( ieneral Electric Co.
though il fluctuates considerahly, due to the throwing on
and off til' some of the larger motors. After Hi o'clock
at night and on Sundays it is only nominal. The con-
nected load is 130 motors, these totaling only 208 hp., as
many of them are used on sewing-machines, stitchers, en-
velope-sealers, adding machines, etc., and consequently are
of small size. All operate at 110 volts and with the ex-
ception of a few shunt machines are compound wound.
Pig. (i illustrates the daily reporl sheel used tit the
plant. The accompanying tables show the operating costs
for 1911 and 1912 tinder the conditions just enumerated
and the earnings when charging current rates for the
same son ires. In computing the expenses only half of
the chief engineer's salary was charged, as but half of
his time is devoted to the plant. The fixed charges arc
those prevalent in the city, as are the rates assumed for
.54
P O W E R
Vol. 41. No. 2
electric current and heating. The rate of $7 per day
for the six elevators is an estimate, as is the 2c. per 100
eu.ft. for pumping. In 1911, the plant paid a dividend
of $5227.84 on an initial cosl of $30,000. Tins is a divi-
dend of 17.4 per vent. For L912, a net earning of
$6450.24 raised the percentage to 21.5, figured on the
original investment, with no reduction to the depreciated
value. To the present value of the plant the earnings
would bear a much higher ratio.
To arrive at the cosl per unit of generating current i:-
difficult, as the steam I'm- the pumps and engines has nol
been separated: the same applies to the labor and sup-
plies. An approximation would be to deduct the earnings
for other services from the total expenses and divide by
the kilowatt-hour output. For 1911, the balance left for
the generating plant would be
$11,971.03 — $9866 = $2105.03
Dividing by the output. -241,129 kw.-lir.. gives
$2105.03 -^ 244,429 = $0.0086 = 0.86c. per kw.-hr.
For 1912. the balance would be
$12,660.87 — $9912 = $2748.87
Dividing by the output gives a cost per kilowatt-hour of
$2748.8' I- 306,637 = $0.00896 = 0.896c.
While these figures are only an approximation, they shew
that the plant is giving g 1 service and that its com-
mercial lite i- net seriously endangered.
■<£©inis{tom<c4iini
t>a
>r
SYNOPSIS — With a hand-fired furnace the boil-
er should be horizontally baffled, and department
No. 8 furnace is recommended. Some interesting
low-headroom installations.
By Osbobn Monnett|
thought, was made in a modern office building. The orig
mal intention was to use central heating service. Then
was 14 ft. for headroom and the problem was solve.
A--,
Cleaning up band-fired settings in connection with
water-tube boilers is comparatively simple it the boilers
are of the horizontally baffled type, as ordinarily there -
enough headroom for a good hand-fired furnace and the
C"
<— $#•■-■
- * 1
1
^^ — -
^^-^
Fig. 1. Deumless Edge Mom; Wateb-Tube Boiler. 213
ill'.. Wli II 'ND-FlEED FUBN U'E
proper combustion-chamber areas. In working over this
kind of setting, the No. s furnace should he used. (For
reference, see page 266 of the Aug. 25 issue.) Vertical
baffles in a water-tube boiler must he horizontal before
there is any hope of cleaning up the setting.
. Sometime- an installation musl he made under re-
stricted headroom, particularly in office-building plants
where the architect usually neglects the boiler-room space
until the construction has gone so far that no adequate
headroom i- available. There arc. of course, other circum-
stances that sometimes govern the doing of low-headr i
jobs on new work.
Fig. 1 is a typical installation which, is an after-
•Copyriglit, 1914, by Osborn Monnett.
■ Sinoke inspector, City ol Ch ai o
rtf_ ^^
LONGITUDINAL SECTION
Fig. 2. A 400-Hp. Water-Tube Boiler and Down-
dllaft fubnace with sprung arch to provide
Travel and Mixture
Fig. 3. Babcock & Wilcox Boiler, 300 Hp., with Full
Extension Down-Deaft Fuenace \nh
Mixing Aeches
by installing a drumless Edge Moor boiler with a com-
bination T and box tile hand-tired furnace, having the
deflection arch described in previous article-. The dis-
January Vi, 1015
P 0 YY E B
tance from the floor to the bottom of the front header wa-
5 ft. 6 in., and from the top of the front header to the
floor it was 12 ft. 2y2 in. With proper operation this set-
ting can be expected to give lj « »< •< 1 results.
Vertically baffled water-tube boilers aie Bometimes
equipped with down-draft furnaces, both full extension
and flush front, but the combination generally makes a
bad -miikcr. The flush front setting must be horizontally
baffled before it ran be cleaned up. With the Full-exten-
sion furnace it is possible to interpose brickwork construc-
tion which will increase the flame travel and mix the
gases before they strike the heating surface.
Fig. 2 illustrates a full-extension, down-draft setting
for a water-tube boiler, in which an arch 5 ft. 6 in. long
lias been sprung hack of the bridge-wall, with suffii
i area past the arch to allow the gases to escape. The
bridge-wall action is good, as the radiation from it has
the effect of maintaining the temperature of the ■_■
and as the gases impinge against it in changing their di-
rection, combustion is aided materially. In new down-
draft furnaces and water-tube boilers, the latter always
should be horizontally baffled and the furnace have de-
flection arches.
Fig. 3 show- another down-draft installation set full
extension. As shown in the drawing, the construction
Wg&sfte H©£ Water ieat§ Feec
Fig. -i. A 375-Hp. Dettmless Edge Moon Boileb and
BUBKE FtJBNACES SET IX HEADBOOM OF 11 Ft. 5 In.
calls for a high-temperature zone over the bridge-wail
and a deflection arch in three spans before the
pass to the heating surface. These compromise settings
musi be taken for what they are worth in cleanin|
existing plants rather than as satisfactory settings for new
installations.
Pig. 1 illustrates an interesting case where a 375
hp. drumless Edge Moor boiler served by Burke furnaces
was set in a beadroom of 11 ft. 5 in. Here are conditions
which are sometimes met when putting a plan.
in an old building. In this case the building Mood on a
floating foundation, consisting of a mass of concrete
and railroad iron in which it was impossible to do any
excavating. At the same time it was impossible to raise
the ceiling as it would then interfere with valuable floor
space in the office building above. Therefore, the boileT
installation had to be sacrificed and the design shown
herewith was adopted. One of its features was the loca-
tion of the safety valves. The headroom was so restricted
that, they had to be set, one on the side of the head r,
with a U-tube connection into the steam space o
ler. Notwithstanding the conditions thesi jetting:
have been running successfully for years without smoke
and without any unusual difficulty with the boilers.
Bi I". B. Hays
The writer recently designed a chemical plant in which
several no i atures were embodied. The
interesting, from a power standpoint, was the man-
ner in which the boiler (n^] water was heated.
The plant contained a batten of three boilers, two
being in service while the third remained idle for clean-
Fig. l. Jacket of Chemical Tank- as Feedwatee
1 1 i >
ing or emergency. The -team was used directly in re-
duction tanks, becoming a part of the final chemical
composition manufactured. This left no exhausl -team
for heating feed water, and as there was much waste heat
in the plant, it was not considered advisable to use live
steam. Cooling water used to reduce the temperature
and prevent explosions in the chemical reduction tanks
was going to waste. After a careful study of the operat-
"liditions in the reduction tanks it was decided that
the cooling water could be used for heating the boiler
feed water, and the latter kept at a fairly even Ten,
ture provided a suitable heater was installed. The heater
shown in Fig. 1 was finally chosen.
The general arrangement of
the whole system is shown in
Fig. 1. in which are the reduc-
tion tank- .1. where tempera-
a from TO to 000
deg. F. are produced by the
!i reactions; the water
B -iirround the cookers
Q of the reduction tank-, into
which the (doling water enters
,-it a. and, becoming hot, flows
out at 6 and through the pipe D
into the boiler feed-water heater
E at c. The boiler feed water
through the pipe
/•' and enters the heater at e. It leaves the heater at h
for the boiler-feed pump, after it has become heated h\
the cooling water from the reduction tanks, and has in
turn cooled this cooling water. The cooling water re-
liction tank- by the pipe K. The cir-
culation of the cm, Img water is by gravity.
Due to the big iture frequently produced in
the cooker-, provision had to be made to take care of
steam iter. This was done by means
of an overflow pipe .1/. which discharged into the radia-
tor E at i. from which it flowed into the heater E ar ;■.
Fig. 2. Section of
Overflow Box
56
P 0 W B E
Vol. II. No. •>
The construction of this radiator is shown in Fig. 2,
where / is the pipe by which the water and steam from
the reduction tanks enter the radiator, 11 the tubes where
the steam is condensed, K the water tank of the radiator,
and .1/ the overflow pipe from the water tank to the feed-
water heater. The object of this type of radiator was not
only to condense and utilize the steam from the cooling
system, but also to keep hot water flowing into the feed-
water heater at all times. Since the temperature in
the cookers varies as much as 400 deg. in an hour, it will
be readily seen why such a device is necessary. On account
of this same variation in temperature, the cubic contents
of the feed-water heater had to be far in excess of that
normally used or required in proportion to the area of its
heating tubes, so that it would act as a large heat reser-
voir, which would not be readily affected by sudden
i banges of temperature of the feed-water passing through
the cookers.
jm
SYNOPSIS— Will Quizz asks about the shape of
steam nozzles and is surprised to hear that an en-
larging nozzle of the correct proportions will cause
an increased velocity of the steam jet.
•■Chief, what is the reason for the shape of the nozzles
in our turbines? Instead of pointing the little end of
the nozzle toward the rotor the big end points there."
''This is done, Will, to give a greater velocity to the
steam. Fig. 1 shows that the velocity of steam issuing
from a straight nozzle is almost constant for all pres-
sures."
"How can an enlarging nozzle increase the velocity:"'
"It is like this, Will; back in 1883 Dr. DeLaval
made the first use of such a steam turbine by applying
it to milk and cream separators. After experimenting,
he concluded that the successful motor of this type should
utilize the velocity of the- steam rather than its direct
action by pressure. His first step, therefore, was to con-
vert the force in the steam into kinetic energy and obtain
the highest possible velocity for the steam. He conducted
A-Curve showing the speed of steam at various absolute pressures
when discharging into the atmosphere through a plane orifice.
B- Curve showing the speed of steam at various absolute pressures
cd o when discharging into an 86.6% vacuum.
'§> * 1500
V. £ 1375
If
i|'25°0 Z0 40 60 80 100 CO '40 '" 160 180 200 220
""j; Absolute Steam Pressure in Pounds per Sq. In. Power
under pressure, would urge it forward and prevent
any rearward elongation or even any retarding of the
outward flow, so it will be seen that the velocity must
increase in order to allow for the expansion. Fig. 2 shows
the increasing velocity of the steam issuing from a prop-
erly designed diverging nozzle.
"Referring to your steam tables again. Will, you will
see that the specific volume of one pound of steam at 465
lb. pressure is one cubic foot. At lower pressures the
A' Into Atmosphere
B'lnto 86.6 Per Cent. Vacuum
■O4000
c
^3500
<D
0 3000
i£
c2500
V
A--
B>
A
V
-.-.V-
—
0 20 40 60 80 100 120 140 160 180 200220 240 260 280 300320
Pomek Absolute Steam Pressure in Pounds per 5a. tn.
Pig. 1. Steam Velocities with Straight Nozzle Fig. 2. Steam Velocities with Enlarging Nozzle
a number of experiments and established the shape of the
nozzle which would produce this effect.
"Probably the easiest way to describe this would be
by comparing the steam in the boiler under pressure with
a lot of toy balloons in a closed vessel under sufficient air
pressure, so that each one. instead of being some four
inches in diameter under atmospheric pressure, would be
compressed to perhaps one inch.
"Suppose then these balloons were allowed to escape
tli rough an opening just large enough for one to pass
through at a time and into the nozzle of the shape shown.
Immediately after passing through the small end they
would begin to expand by reason of the reduced external
pressure, but if the nozzle did not enlarge in proportion
to this expansion it would elongate and increase its ve-
locity as it expanded.
"This elongation necessarily would have to take place
in the direction of the How because the others, follow-
volume is greater, and at atmospheric pressure one pound
occupies about 27 cu.ft. (or 27 times the original volume
for a given weight of steam). As the pressure decreases
below that of the atmosphere the volume increases rap-
idly, so that at one pound absolute pressure it occupies
333 cu.ft.
"The shape of the nozzle — that is, its rate of enlarge-
ment— must be proportional to the initial pressure and
terminal pressure against which the steam flows, but
the more extreme these two pressures are. the more ab-
ruptly the nozzle may enlarge. Therefore, nozzles are of
different proportions or designs for different boiler pres-
sures and the amount of back pressure or degree of
vacuum into which the steam is discharging. With a
given area of throat or small section the area of any sec-
tion beyond is directly proportional to the specific vol-
ume and to the dryness of the steam, and inversely pro-
portional to the velocity."
January 12, 1 915
k i:
iilllllllllllllii;;:~i
Bow many manufacturers believe thai ii would pay
t< > employ an extra man in the engine room, so tli;if the
chief engineer would have more time in devote to the
boiler room and see that the maximum fuel economy is
maintained ?
Fuel is tin' main expense in all power plants, ami
although many consider it, more ignore it.
In one plant for instance, the owner will not be
bothered about the coal, but insists on purchasing the
ine and cylinder oil himself. The fuel item would
run into thousands of dollars annually; the oil would
cosl a few hundred.
As pointed out in a first-page cartoon some time ago,
the switchboard of most electrical plants carries all the
-ary recording and indicating instruments, so that the
attendant can keep a record of the output in electrical
energy. But out in the boiler room there are only the old
safety valve, water glass and pressure gage, with nothing
to indicate the performance of the boiler. The bills for
coal and supplies come to the office and, although protest
may be made against their size, nothing is done to help
the engineer reduce them.
In other plants some attempts may have been made to
obtain efficient operating results, and perhaps instru-
ments for ascertaining the percentage of C02 in the
furnace gases have been provided, together with draft
gages, steam-flow meters, etc., hut if no attention i-
given them, they might just as well be cut out for all
thi' good they may do.
Pointing out defects i> useless, unless measures an' taken
to remedy them. If help is so limited that there is not
time for some one in authority to find the source of loss
to see that matters are changed for the better, then
good American dollars are going to waste, because
nohody is held responsible for the lo
Engineers well know the situation, and there are
many of them who are striving, even against adverse
litions, to operate their plants economically. There
are others who are indifferent, because the men higher
up do not do their part in preventing losses.
With so many plant owners and managers lax in this
regard, it is refreshing to know that one manufacturing
company (see the article, p. 38) realizes the greatest
opportunity to save is in tin' boiler r< i, and that an
overworked engineer cannot give proper attention to
securing economical operation. For tins reason an extra
man is employed in the engine room so that the engi] r
may give time to getting all possibli t of every pound
of coal consumed in the boiler furnaces. Moreover, in-
struments are provided to show the operating condition-.
and are so arranged that any one of the boilers can he
checked by the instruments.
How many power plant owners believe that if the chiet
engineer is given the opportunity he can more than
a man's wages by properly managing the boiler room?
Why not give him a chance and find out!'
Gefttlnimgg Mew EWsaEaess
Small electric-lighl plant with profit the
accomplishment of the Springfield (Missouri) Gas &
Electric Co.. which has added mo hundred new residence
customers to its circuits in sixty days, with no Ine oi
transforms e pense.
This increase In qi h business is largely accounted for
by thi' lai t thai tin company offered to put in a few out-
let-, and did not insist or v. iring thi & mplete
before putting in the service. This naturally appealed
not only to owners, hut to renters of even small houses.
With the service once in. the convenience was apparent,
and additional out added here and there, so that
what did not represent an attractive connected load at
first has gradually become a profitable one.
A small station cannot hope to obtain the same number
of new connected houses in the same period as did the
Springfield company, hut what is to prevent the idea from
being worked out on a smaller scale in smaller cities ami
towns? It would appear to he worth trying.
Hearings on tin' Ferris water-power hill, before the
Senate Committee on Public Lands, developed that its
passage in the Senate will 1 pposed on. two ground-.
A small clique of Western senators will oppose the meas-
ure because they want the dam sites in the public domain
deeded over to tin- states without condition. The in-
fluence of large hydroelectric promoters and operator-
will lie exerted against it because they want power sites
given to the companies in perpetuity. The bill as it
passed the House proposes that power sites on the govern-
ment lands shall he leased for not more than fifty years,
and that the property shall reveri to the government at
the end of that period.
It was brought out at the hearings that Canada. Nor-
way, Sweden and other countries where there are large
water power- have secured their development under \er\
much the same plan as that, now urged by the adminis-
tration and embodied in the Ferris hill.
Upon the action of the Semite on this hill and on
the Adamson dam hill, both of which have passed the
House and are awaiting senatorial action, depends wheth-
er there shall In' any extensive development of water
powers in the United States in the near future. Under
present laws, such developmenl is almost impossible. So
■'v a- Western water powers are concerned, they are prac-
• ally all in one of two classes: either held in private
mership by large corporations which form what Gifford
in hot and oilier- declare to be a "water-power trust."
or they are within the public domain, under the owner-
ship and control of the Federal government. In the
East and South, there are also large potential water pow-
ii navigable streams which can be utilized only by
permission of Cong
1'OW EI!
Vol. II. No. ■•
The War Department claims jurisdiction over naviga-
ble streams, on the ground that any obstruction of these
affects navigation, which is under Federal control. In
the public domain, there has been some granting of per-
mits for water-power development along streams in for-
esl reserves, which are under the control of the Depart-
ment of Agriculture. So far as power sites in the public-
domain outside of the forest reserves are concerned,
however, there is no law permitting any leasing or per-
mits. They must either be withheld entirely from use,
or given away as farm lands to anybody who asks for
them. Judge Finney, of the Interior Department, told
at the hearings of one power site acquired by a power
company from the government at one dollar and twenty-
five cents an acre as agricultural land, and capitalized at
twenty-six million dollars by the corporation which se-
cured it.
These water-power hearings have brought out clearly
the story of how the water powers of the West are monop-
olized, and the ramifications of the big power corpora-
tions. They have also served to point out forcibly the
difficulty that exists in drawing the line between state
and Federal authority in the control and regulation of
these matters. All the water in the streams is owned
by the states. The courts have said that more or less
clearly. So far as its use is concerned, however, the
Federal government has control over everything affect-
ing navigation, and the courts have not decided just how
far back toward the source of the stream that extends.
In the proposed general dam bill, the power claimed
I iv Congress is drawn entirely from its right to control
navigation. Even if a corporation owns a dam site, and
the state in which the site is located has granted a right
to the use of the waters of the stream, the dam-site owner
cannot build his dam without the consent of the Federal
government, on the theory that the dam might interfere
with navigation. In the past, permission for the building
of dams and power plants along such streams has been
made the subject of special aits of Congress, it being
necessary for a company to get a specific act through
Congress to enable any dam to be built. In the pending
hill, it is proposed to make a general law governing the
granting of such permission, and allow the Secretary of
War and the Secretary of the Interior, under certain re-
strictions and conditions, to grant such permits.
The Adamson bill would open to use, under regula-
tion, the unused water powers and power sites in the
Bast, South and Middle West. The Ferris hill deals
with the water powers in the public domain, which is
almost wholly in the far West. The latter, in fact,
makes no proposal for regulating the use of water power-,
but deals wholly with power sites. However much power
there may he in a stream or a waterfall, it is useless
unless there is a place to build a plant for its develop-
ment. Where these dam sites and power-plant sites are
mi land owned by the government, the Ferris bill pro-
poses that the government shall lease the sites on such
terms as will enable the government to forever control
the development of power at that point.
In an effort to propitiate the "states' righters," the Fer-
ris hill proposes that where electricity is used in the same
state in which it is generated under a Federal lease, the
operations, rates, etc., -hall lie subject to state regula-
tion, where there is a state utility commission. Where
there is no state regulation, the government is to do the
regulating. Where power is generated in one state and
carried into another state for use. that used in the state
where it is generated is to he under state regulation and
that in the other state to he under Federal regulation.
Where the company does an interstate business, however,
not only the current which is sent across the state line,
hut also the entire assets and affairs of the company
generating the power will come under Federal control
and regulation. In actual operation, it seems probable
that the effect of the proposition, if the hill becomes ;i
law. will be to have both Federal anil state regulation over
the same enterprises.
The bill proposes that the rental charged by the govern-
ment for the power site shall be decreased in proportion
as the operating company decreases the price to con-
sumers for light and power. Senator Smoot, of Utah,
who opposes the measure, ridiculed this proposal in the
committee hearings, on the ground that it would be more
profitable to the companies to pay the higher taxes and
exact the higher rates.
The money derived from leases of power sites is to be
placed in the reclamation fund, and after it has once
been used for reclamation projects and repaid to the gov-
ernment by the water-users on these projects, it is then
to be equally divided between the states and the govern-
ment.
How many 'hief engineers encourage their men by
expressing satisfaction when work has been well done?
How many comment favorably upon the personal appear-
ance of their assistants? What would he the result if ap-
preciation were expressed? Nothing will encourage a
man to do his best so much as the knowledge that his work
has received recognition. Nothing will cause a man to be-
come disgruntled so much as an attitude of nonapprecia-
tion on the part of the chief.
An assistant engineer need not fear being classed a- a
■"dude'" because he prefers to go about his work with clean
clothes. If he does not keep himself clean and neat, the
chances arc that he will be slovenly about his work. Some
engineers have the appearance of coal passers, and their
plant presents the appearance of having seen better day-.
No self-respecting man ran be content to work in a dirty
engine room where it is impossible to keep himself in a
half-way presentable appearance. Encourage men to do
better work, to keep the plant clean, and their own im-
proved appearance will follow.
If a man thinks well of himself, and he will in cleanly
surroundings, he will think well of his chief and of the
company that employs him.
X
Xot a single passenger out of the 185,411,876 carried in
1914 on all of the 26.19S miles of track of the entire Pennsyl-
vania R.R. system was killed in a train accident.
This looks to us like real forethought and true business
acumen on the part of the Pennsylvania R.R. Tt realizes
that the nunc passengers it kills the less it will have to
carry, so it tries not to kill any. Last year it was suc-
cessful and had a perfect score — no misses.
Indexes to Poweb arc furnished free to all who re-
quest them. That lor the la-t half of 191 I will soon he
ready. A simple request, addressed to the Subscription
Department, Power, will bring one
January R\ 1915
row EB
59
Correspomdleinice
ii
Stresses lira CtDimvesx Headls
In the Dee. 8 issue there is a discussion of my contri-
bution to the issue of July 7 concerning stresses in con-
vex heads. The first remark by Mr. Vander Kb to the effed
that the results of my analysis are at variance with opin-
ions previously expressed depends on the poinl of view.
When an abstract analysis of a statical or physical prob-
lem is undertaken, all opinions, even those of the mathe-
matician, are irrelevant. The matters pertinent to the
analysis consist of, first, the premises upon which the
analysis is based; second, the propriety of the mathe-
matical processes that are employed, and, third, the speci-
fication of the consequences of the analysis. I fail to see
anything peculiar in the fact that an attempted analysis
of a problem in statics leads to results at variance with
current opinion since current opinion, heretofore, has been
at variance with the facts concerning the safety of con-
vex heads.
Concerning the more direct discussion of the analysis
by Mr. Vander Eb it is fair to examine the premises upon
which my analysis is based for the errors which are said
to exist. He asserts that I have neglected the deflection of
the dished part of the head "by simply assuming that a
purely spherical tension at the circumference is all one
need to expect." Tf anything new in the way of theory of
stress in spherical shells, or in portions of them, can he
offered, there may be sufficient evidence to enforce the
abandonment of the respect for such writers as Rankine,
Church, Merriman and Cotterill.
There is nothing more explicit than the statement of
Rankine ("Applied Mechanic-," p. 290), viz., ■"hence the
whole force to he resisted by the tenacity of the shell is,"
etc. The statement admits of no shearing stresses or any
stress in the spherical shell other than a simple tensile
stress. The presence of shearing stresses would cause
local deflection from the spherical surface and their ab-
sence precludes "deflection."
Referring to Fig. 2, by Mr. Vander Eb (which is sub-
stantiallvthe same as Fig. 4 of the July publication), it will
be seen that the element of the flange fillet is completely
supported by the system of forces as specified. Some of
these forces constitute "reactions" on the part of adjoin-
ing material which, if properly accounted for. dispose of
further consideration of such extraneous material in the
analysis. I have shown the justification for the accept-
ance of the force T as a simple tension unaccompanied
by shear stresses on the face DC of the element. If there
is any bending of the material of the plate at the section
AB. there is at least a "stress couple*' and possibly shear-
ing stresses. By the selection of the origin of reference
at 0', at the middle of the plane AB, all effects of these
shearing forces from the moment equations are elimi-
nated.
A little reflection and reconsideration of the detailed
analysis in the article of July ? will show that Mr. Vander
Eb is wrong in asserting that the element of the flange
fillet is considered as a beam with "free" ends. The re-
mainder of this paragraph in the Dec. 8 article is some-
what questionable in the attempted substitution of impres
sionc, however plausible they may appear, for the logic ami
conclusions of a statical moment equation that is either
right or wrong. In the interest of engineering progress,
the elimination of errors should be the ambition of all con-
cerned. 1 cannot see the justification for the introduction
of the forces on the sides of the element (Fig. :i of the
July 1 article) for reasons explained originally.
Mr. Vander Eb overlooks the fact that the analysis con-
templates attachment of the convex head to a rigid cylin-
drical shell as "a yield of the structure at the flange con-
nections would seriously complicate the stress-strain re-
lations.*' Furthermore, a yield at this point would be in-
capable of analysis with the present limitation of the
theory of statically indeterminate structures.
With much of the remaining discussion I have but little
reason to dissent. One criticism of my article, and all
similar articles, was overlooked which I will undertake to
supply. The analysis may be wrong because it has as-
sumed a homogeneous molecular state of the material in
the plate after it has been heated, flanged, cooled ami
forced into shape and place by any practicable flanging
process. There is no means of estimating the magnitude
of the initial strains in a dished head, and particularly in
the region of the flange fillet. These may he, and in cer-
tain cases actually have been, so severe that the heads
cracked while they were being riveted to the shell. At the
risk of a small increase in cost of boiler construction, si
flanged head could be subjected to suitable heat treatment
or at least proper annealing when, if ever, the plate may
be assumed to be free from internal strain.
F. (i. Gasche.
South Chicago, 111.
S>a<ale
Why the tubes blistered on one side of the bottom
row in one of our water-tube boilers was not found out
until the mud drum was opened. As shown in the illus-
J . J ( J i J , J , J -, J , J , J r\ J r\Sr ri -I -i O -i J
Blow-off Pipe Open at Oxe End
tration, the blowoff was connected to a tee inside of the
mud drum, into which were screwed two short lengths of
pipe supported about 2 in. from the bottom of the drum
and having t.j-in. holes drilled in the lower sides and the
ends capped.
60
P()W E R
Vol. 41. X.i. v
One of the cap? had worked off and consequently all
of the drainage or blow was from that end. The sediment
gradually accumulating at the other end had stopped the
circulation in the tubes and allowed them to become over-
heated.
Edw auu T. Binns.
Philadelphia, Penn.
Xew trash racks were to be placed in front of the water-
wheel chambers at the hydro-eleetrie plant in which the
writer is stationed. On letting the water out of the head
Dirt at the Intake Screens
race, which is about 16 ft. to the concrete footing on
which the bottom of the racks were to rest, the footing
was found to be covered with sand to a depth of 1 or 5
ft. Much of this sand was removed by shoveling, but
as There was some water dammed up behind this bank,
which could be drained out, the sand was washed in
almost as fast as it could be shoveled away.
In the plant we have main- carrying water at a pres-
sure of about seventy pounds. The use of this water to
do the work was suggested, and the plan was carried out
with success. A line of 3-in. pipe was couple. 1 to the
water main, and to this pipe a 3-in. suction hose was
onnected. A nozzle was needed and as none was at hand.
- pr ided to make one out of a short pieca of 3-in.
pipe about :! ft. long and threaded at one e.id. The
other end was heated in a forge and the edges flatteiic. '
leaving an outlet li/o hi- diameter and flared back to the
diameter of the pipe. This nozzle was coupled to the
hose and the full pressure turned on. The sand was thor-
oughly stirred and in a short while most of it was carried
off. The rest was kept constantly stirred by the water.
ami the racks, section by section, quickly dropped into
place. Tlic illustration shows the head race.
J. M. PURCELL.
Richmond; Va.
We have a small direct-current, shunt-wound motor
that had been used satisfactorily for driving a bottle-
washer by throwing directly across the line in starting.
When it was belted to a jigsaw, where there was more
friction, it had to be helped in starting. Believing that
the heavy starting current might have so weakened the
-hunt field a- to reduce the torque, the writer placed a
bank of lamps in series with the armature, upon which
the motor started easily, although the running speed was
reduce. 1 somewhat.
It appears that above a certain point an
mature current in a shunt motor reduces the torque in-
increasing it.
Walter S. Griscom.
Buck Hill Fall-. Penn.
x
Pipe Beiadleir
In a plant where it was necessary' to bend pipe oi •
rious sizes from 1 to '.'^ in., the simple pipe ben. lei >!i.m
did good work.
A 2-in. hardwood plank 18 in. long by 1".- in. wide.
Pipe Bexdixg Form Clamped ox Post
rounded off at one end to a 6-in. radius, was fastened to a
post m the -hop. Two pieces of I'-a'^-hi. Hat steel /•'.
ch side, and extending 5 in. above the top of .1.
J a Hilary 1;>, 1915
I'OW EB
CI
hail a number of %-in. holes for a pin to hold the various
sizes of pipe. On the rounded end was fastened a swing-
ing arm or lever and roller held in place by a bolt through
two pieces of l%x^-in. Hat steel, and pipe extensions of
different lengths furnished the required leverage to bend
i he various sizes of pipe.
The method of operating is to hold one end of the pipe
to be bent in the space between A and a pin in ('. and
bring the roller to hear slightly, then draw the pipe for-
ward an inch or two and repeat the operation until the re-
quired bend to any number of degrees is completed. This
apparatus is inexpensive, easy to construct and is conven-
ient lor making offsets ami lateral bends.
W. E. Chanulek.
Quinebaug, Conn.
In the Nov. 10 issue, Mr. Ilerr asks for information
about material for gaskets lor plugs in ammonia-valve
bonnets.
There are four kinds of valve bonnets for ammonia
compressors. The most common form is such as is found
on the Linde type of machine. It is held in place by
studs or capscrews and the gasket fits into a recess so
formed that the male part of the bonnet holds the valve
cage down to its seat in the casting. Almost any ordinary
gasket, rubber, lead or other material, will make a tight
and lasting joint. One-sixteenth-inch lead or rubber
sheet packing is much used, hut if the joint is troublesome
the use of one-sixteenth-inch rubber packing of nearly
pure gum is advisable.
Before inserting the gasket, it should be noticed that
the top ol the valve cage projects about one-sixty-fourth
ill an inch beyond the surrounding surface. If the cage
has been ground into the seat and the top is below this
surface, an extra gasket must he used which fits the valve
cage only and acts as an extension to it, allowing the bon-
net to hold the cage tightly in place. Neglect of this will
allow leakage between the head or cylinder casting and
the cage, proving no better than a leaking valve. This
style of bonnet is found on compressors of many makers.
There is a bonnet where the valve cage is set in the com-
pressor head and held to its seat by a ring or nut; the
bonnet is screwed into the head outside the ring. Kubber
gaskets are supplied by the builders of the machine and
never give any trouble when inserted properly.
Then we have the style of bonnets used on the old Boyle
and Pennsylvania Iron Works compressors. Here a yoke
is used, the studs being screwed into the compressor head
and an iron strap reaching from one stud to the other,
with the valve bonnet between the two studs. A setscrew
passes through the strap and when screwed down force*
the bonnet to its seat. The same material can be used for
gaskets as in the Linde type, but pure gum is preferable
as it is soft and does not require such pressure as does
lead to make a tight joint.
There is another type where the valve cages are put in
from the cylinder side of the compressor bead and the
bonnet screws onto the threads on the outside of the up-
per end of the valve cage. The cage is kept from turning
by a dowel pin. Sheet lead one-sixteenth-inch thick is
the proper thing for these gaskets as the turning effect
of the bonnet might tear or misplace a rubber one. I £
the joint is a particularly troublesome one, put a gasket
of one-thirty-aecond-inch pure gum beneath the lead.
There is no reason then why the joint should not be
tight unless there is sonic defect in the casting or tin
valve cage is too long, the top of it striking the inside
of the bonnet before the gasket is pressed tight.
The temperature of an ammonia compressor should
never be so high that it will melt lead. Use plenty of
water over the jacket or send the suction vapor to the
compressor in a slightly saturated condition. Properly
cut and inserted gaskets id' either one-sixteenth nub
sheet lead or of good sheet rubber will keep these from
leaking unless something is mechanically wrong.
The nuts, capscrews or screwed bonnets of compressor
valves must be frequently tried with a wrench as the
changes of temperature to which they are subjected will
cause them to become loose.
A. G. Solomon.
Hhicago, III
V
Cylairadleir=Iiiesidl Ft&cfeaira^
A good gasket, which will hold where rubber will not.
may lie made of copper wire if the surfaces are reasonably
smooth and true. The copper should be annealed by
heating it red hot, then dipping it into water once
or twice, or until soft enough. Gaskets may be made of
any size suitable to the work from % in. to VC4 in. After
the wire has been annealed, draw it around the cylinder
head and twist it a couple of times, and then flatten the
twist a little thinner than the wire.
Either solder the ends or wind candle wicking around
the joint. Put the cylinder head on and draw up evenly
on all the bolts, anil then hammer a little on the bead over
the wire to flatten it. Next, take up snugly on the bolts.
Soldering the gasket to the bead will keep it in one posi-
tion all the time anil will be convenient if the head is to
lie removed frequently.
John P. Kolak.
! thaca, N. Y.
I have a simple and convenient tester for lamps and
fuses, the wiring plan of which is shown in the illustra-
tion. The metal part id' the socket A is slit and opened
LiAMP- AMi b USE-TESTING BOARD
so that the lamp need not be screwed in, but simply
pressed in.
II is a lamp screwed in permanently as an indicator
62
POWER
Vol. 41, No.
in testing plug fuses at C by placing the end on the bot-
tom connection and the side in contact with the metal
side. II' the fuse is good the lamp at />' will light up.
Contacts D and E are for testing cartridge fuses.
The dotted line shows a Euse in place with the sliding,
metal-bound Mock /•,' pressed against one end. The outfit
.an lie mounted on a marble slab or asbestos-covered board
to suit one's fancy.
James G. Sheridan.
Brooklyn, X. Y.
In the Dec. 15 issue of Poweb appeared an article on
the use of cement tor furnace lining as practiced by the
Robert Gair Co.. Brooklyn, X. Y. This called to mind
in experience I mice had in repairing the setting of a
250-hp. water-tube boiler in a remote part of the West
Indies.
One day we found ourselves short of fireclay, due to
a delay in shipment, and it was necessary to repair the
boiler setting at once, and replace practically all the fire-
brick around the door arches, etc. We tried to buy oi
borrow enough fireclay to do the work hut everyone seemed
lo be short at the same time.
In the neighborhood was a small pottery plant, so a- a
last resort we decided to see how good a fireclay this un-
burned pottery day would make. We were surprised to
find that it lasted longer than the brick and fireclay
around it.
F. E. Wood.
Whitinsville, Mass.
oil' for repairs and the eccentric straps were tightened
up. Ine added friction, however, retarded the governor,
causing earlier cutoff and reduced speed. When a papei
liner was put in the trouble stopped.
At another time the same engine ran unsteadily,
(.'banging the adjusting screw in the oil bypass of the
dashpot helped some, and when a lighter grade of oil
was substituted, the engine governed satisfactorily.
Sometimes the roller bearing, which has jjVin. rollers,
wears slots in both the hushing and the pin. This retards
tlie action of the governor, hut a new set of rollers, a pin
and bushing will make it entirely new.
Governors of this type must work very freely, other-
wise they cause a great deal of trouble.
J. C. Hawkins.
Hyattsville, Md.
The top diagram shows a combined feed-water heater.
In our plant the returns from the heating system ami the
exhaust from other pumps and engines return to this
Cold Water Supply
■Blowoff
Pipes
An inertia governor of the type shown gave consider-
able trouble on account of its sluggish action. After run-
ning for an hour or two the speed would drop for a mo-
Inertia Bar and Eccentric
ment, then pick up again and be all right for a while.
The eccentric ran a little warm after the engine bad been
Heater before and aftfr Beixo Iiemodeled
beater. There is no oil separator in the exhaust line from
the pump, consequently oil gets into the heater.
As originally installed, the apparatus gave no trouble
so long as the man in charge was careful to use the blow-
off cocks to rid the heater of oil. One night the fireman
pumped the heater dry, not noticing the lowering water
level until too late. There was considerable oil in the
beater at the time and it got into the boiler.
To avoid further trouble, the suction line to the heater
was made to enter the tank in the center of the head as
shown at A, while the original suction line B at the bot-
tom was plugged. Between the head and shell there was
placed a -beet-iron plate ('. i/s in. thick. At the top a
%-in. hole was bored and at the bottom a 2^-in. opening
was allowed in the plate, the water going out of this hole
on its way to the pump. The function of the %-in. hole
is to prevent the pump from siphoning the water in the
heater over into the suction line. With this arrangement
we are never troubled by oil getting into the boiler.
II. o. Gibson.
Washington, l>. (\
January 12, 101o
P 0 W E R
63
)@f@sadls Mis AdlsiaSffii
The attention of readers of Poweb is called to the ar-
ticle appearing in the Nov. 3 issue of thai paper, page
f>28, in which statements were made thai the power
plant in the lintel La Salle. Chicago, 111., was not oper-
ated efficiently during the years 1910 and I'M! The
following facts and figures re in contradiction to these
statements.
The Hotel La Salle was opened in 190!) under strike
conditions of the mechanical trades, there being thousands
of dollars' worth of unfinished work which had to be fin-
ished alter the house was opened. Also revision of plans
and certain changes necessary to be made to suit condi-
tions made an enormous amount of extra work to be com-
pleted by the engineering departmenl and necessarily
d a large expense foi labor and material, which was
chargeable to the engineering department, but should
ive b 'en i harged as an item of operation.
Ii was required by the managemenl ai thai time that
the house be thoroughly ventilated at all times, which
required all ventilating fans in ]„• operated constantly .at
then- scheduled speed for furnishing the quantities of air
required. Voluntary information handed the writer from
a person who served in the mechanical department under
Mr. Bird, present chief engineer, states that replacing the
Keep., 60-watt lamps through the house with 25-watt
tungstens shows a saving of 43 1 kw. on lighting load
alone. This change was often suggested by the former en-
| t. but was not entertained by the management. He
also states that over 100 lip. in motors were closed down.
the greater part being on ventilation. Relative to these
items, it is beyond contradiction that there is any credit
i i discredit due either engineer, as the same sa\ ing would
have been effei ted had the company seen lit to make such
hanges in sen ice before.
It is not the purpose of this article to reflect on the
I resent management of the plant, but simply to submit to
your readers such facts and figures as will contradict the
Misleading statements reflecting on the former manage-
ment.
The steam traps mentioned in the article of Nov, 3 were
one of the best known makes, which gav: excellent satis-
faction, and owing to the complete system of pi] ing there
were but very few traps required for lie handling of all
condensation from the entire house, each trap being fit-
ted with test valves below the valve in the main discharge
pipe m outer to test the traps for leakage. Each trap was
tested daily by closing off the discharge valve and opening
the test valve, allowing the trap to discharge into the at-
mosphere, to determine if the trap was working properly,
it seldom being necessary to renew seats or valves. It is
therefore flatly contradicted that there was any loss of
-team from this source.
Also during- the time the hotel plant was operated by
the chief engineer previous to Air. Bird's time, vacuum
cleaners were in constant use. They were three in num-
ber, and a great deal of the time during the day the
three were in use at once. Probably Poweh has not
been informed that these are now used but very little.
Another item which should have reduced the operating
expenses of the plant was the discontinuing of several
hundred lights around the banquet-hall windows and 19th
floor. 1 luring the previous engineer's time at the La Salle
Hotel, these lights were required to burn from lighting
time in the evening until 1 a.m. It can readily be =een
that by discontinuing these lights the load would be
greatly reduced, which also has no reflection upon the
engineer.
There were always constant changes being made in
rooms, kitchens and other portions of the house for the
firsl two year- which required an extra force of men, all
of which came under the chief engineer's charge and were
chargeable to his department, although not an item of
plant operation.
We wish to state further that during the coal shortage
in the winter of 1910, the hotel company, not being under
contract with any coal concern, made it necessary to burn
whatever coal was mi the market, and the greater part of
the time coal was used thai ran 20 per cent. ash. making
it necessary to run from one to two boilers more than
should have been run if good coal could have been ob-
tained, to say nothing of the high prices they were ((im-
pelled to pay. Xo -team was allowed to go to waste at
any time, as a daily record was kept of the amount of
water evaporated and the coal burned. These records were
absolutely correct, as the meter was inspected once each
month by an expert from the Wbrthington Meter Co.. and
if any repairs were found necessary, they were made by
him. Evaporation was kept up to the highest possible
point at all times as the test made by a prominent engi-
neering company of Chicago will show.
In reference to the operation of the different electrical
units, it was found to he impossible to change theii
schedule at that time as the official test also shows they
were operated at their most economical point. Xo
steam ever escaped from exhaust pipes in winter except
in very mild weather or perhaps for a short interval at
lighting time in the evening, while engines were being
changed. All rooms were supplied with artificially cooled
air in the summer months that were designated to re-
ceive it.
The cutting off of this service would also reduce the
operating cost, hut with no credit to the present engi-
neer or discredit to the former, as the entire plant might
be shut down and have no expense at all. It is a well
known fact that during the former chief engineer's time
at the hotel, the power plant was a credit to a house of its
kind. It was light, clean, well kept and with smooth
running machinery. Today it will speak for itself. It
is a very easy matter to cut down expense at the sacrifice
of the plant.
Such furnace changes as were made speak for nothing
unless a higher C02 or a higher evaporation can be ob-
tained, which the previous article has failed to show, hut
which is shown by the tesl made by the engineering' com-
pany to he above the average evaporation for the besl
equipped plants. It is plain to see. according to the
article printed in Power of Nov. 3, that no tests of any
kind were made by Mr. Bird to determine the amount i I'
work done. Tne article merely states that "eight pounds
of water were evaporated per pound of coal,'" hut for all
the figures shown it might lie four or it might he fifteen,
but not so in this article, as the facts and figures are
here in detail and are signed by a company recognized
as high authority on scientific tests. Note the evap-
oration, also cost of generating current, and then compare
64
P 0 W E It
Vol. 41, No.
with the article printed on pages 629 and 630 in Power,
Nov. 3 issue.
It is also a fact that the man who operated the hotel
plant previous to Mr. Bird is a person holding a very
responsible position with a large and well established firm,
he having charge of Several large plants, all of which
generate their own power and are equipped with high-class
machinery, which plants employ a very large force of
engineers and mechanics.
No mention was made in the Nov '■) issue of PowEi: of
the new elevator pump being installed in the La Salle
Hotel since Mr. Bird's time, which cost several thousand
dollars and I'rom an engineer'.- standpoint being wholly
unnecessary, as the original pumps never failed to handle
the nine hydraulic cars all in service at once at high
speed, with always one pump in reserve, and at no time
were any of the cars shut down except for repairs and
then only after 1 2 o'clock midnight- as it required the
six passengeT cars to handle the enormous number of
guests in the hotel at that time. Also the installation
of a new hot-water heater, from the same point of view,
would be considered unnecessary, as the heater originally
installed never failed to furnish sufficient quantities of hot
water when the house was filled to its capacity.
Following are some of the important and interesting
facts of the tests made by the aforesaid engineering com-
pany, a copy of which was given the writer by the hotel
management at that time:
Relative to purchasing electrical power: If a lower rate
than 1.2c. per kw.-hr. can be obtained from parties selling
power, it is recommended electrical energy be purchased dur-
ing the summer period, viz., May 1 to Oct. 31. The require-
ments for these six months are approximately 1,540,000 kw.-
hr. The average cost to generate 1 kw.-hr. operating as at
present is 0.72c. during winter season, 2.2c. during summer
season and 1.46c. average for the year.
TOTAL OPERATING COST FOB LIGHT AND POWER
Proportional operating cost generating
steam
Engines a i.l generators, maintenance,
material and supplies
Interest on capital invested in engines,
generator-, switchboard ami inter-
mediate wiring ($49,400@6%)
Insurance and taxes on above appara-
tus l*'0. IIIOOJ L" . I
Depreciation on above apparatus
($49,400(3 I ' , i
Total
Kilowatts
Average cost
Winter
Period
18,452 93
127 so
1,482.00
.".0 mi
988.00
$11,744 M
1,11111.1. Ml
$0.0072
130,742.75
4ti4.ll
1,482 on
294.00
OSS 1111
1.10.', 70
ooi 97
1.97(>.(H>
tei
crated
generate 1 k\v
The average cost to generate 1
period cannot he expected to impro
S45.715.67
3,180,850
$0.0145
Df 0.72c. during win-
but it
$33,970.80
1,540,700
$11 1122
n
is reasonable to believe that the .summer rate of 2.2c. can be
reduced. In view of the fait that electrical power generating
apparatus is installed ami in operating condition, thereby
having a fixed charge, also that a permanent engineering or-
ganization has been established with its accompanying fixed
charges, it will be necessary to obtain a lower rate from
parties selling power than 2 2c, per kw.-hr., the present unit
cost during summer period. In order to ascertain the actual
saving made and the maximum rate that could be paid if
electrical power was purchased, the following tabulation was
made:
FOB SUMMER PERIOD, six MONTHS
Coal, 7500 tons, mums 237.', tmiss. In ■52 011
Labor. 3 oilers (g $1111 per month
Ash removed. !75 cars (6 $2
Maintenance, material ami supplies (from the tost table).
Water, boiler make-up.
Less depreciation on apparatus:
One boiler ami ai ssories, $13,600, (3 2',
Engines and a, ssories, $49,400, to r. ' ,
1,8«2 50
,080.00
950 i hi
404. 11
1 51 1 oi i
Per kilowatt-hour
* Coal required for generating 1
$18,519 ill
1 211
necessary to help oui exhaust steam
l,m ml.
This indicates that a lower rate than
11 have to be obtained in order to make
Iter kw.-hr.
my saving.
General conditions of plant: The power plant as a whole
is in good operative condition and shows careful attention
on the part of engineers in general upkeep and maintenance
of machinery. Indicator cards off engines show good judg-
ment has been exercised in setting valves, adapting them to
best suit services that they perform.
Load Factors:
Total estimated number of lamps (56-watt) in house 22..5IH1
Load factor, per cent 16
Total connected horsepower motors on 220 volts. . 431.8."
Load factor, per cent 50£
Boiler evaporation test: The data and results of boiler-
plant evaporative test are given in addenda herewith. The
results are in accordance with good practice obtained from
boilers of the type installed and quality of coal tired:
ENGINEERING DATA FOR YEAR ENDING FEBRUARY 28, 1911
1910
April
2190.2
Coal consumed under
boiler in tons
Pounds water evapor-
ated per pound coal. oj
Boiler horsepower gen-
erated 727,142
Lights, kilowatt con-
sumption 156,830
I1, ,\\,i. kilowatt con-
sumption 116,000
Tons of ice made . 193
Number cars ashes re-
moved, Illinois Tun-
nel Co. cars 227
663,678
10S.160
May
1880
753,181
146,742
97,828
234
17711
654,543
142, .',1(1
August
2068
Coal consumed unde
"boiler in tons
Pounds water evapor-
ated per pound coal. 5f
Hoiler horsepower gen-
erated 74H,7(i.s
Lights, kilowatt con-
sumption 165,970
Power, kilowatt con-
sumption 141,000
Tons of ice made 254
Number cars ashes re-
moved. Illinois Tun-
nel Co. cars 229
1769
667,857
110,00(1
108,91(1
24N
203 176 200 2(M
1910
September October November Decemb.v
21 123
833,213
184,266
223
1911
1779.8 1718.2
947.876
110,065
786,587
156,120
21132
SI>1,,.'.SII
128,570
Total for
February
Year
1623.1
22,825 8
81
Av. 6.8
805.691
9,313,510
160,000
1,759,688
140,000
1,421,162
211
2,750
January
Coal consumed under boiler in tons 2084 5
Pounds water evaporated per pound coal bfo
Boiler horse power generated 860,454
Lights, kilowatt consumption Pin, !■">.',
Power, ki'owatt consumption 130,455
Tons of ice made 226
Number cars ashes removed, Illinois Tunnel
Co. cars 168 121
OPERATING COST FOR GENERATING STEAM ONLY
For year ending February 28, 1911
Includes cost labor and materia!
Cost for
Winter
Period
Boilers Ss70 or,
Pumps 437.91
Engine and boiler room 7, '.132, 21)
Ash removed 1 ,983.00
33,976.40
Cost for Total
Sun
for
Coal
21(1.00
Water*
Insurance and taxes on steam generating ap-
paratus and portion of building used by
powei plant ($236,200@2%)
Interest on capital invested in steam generat-
ing apparatus and portion of building used
by power plant I $23(1.21 H l«i l', < , t
Depreciation on steam generating machinery
($104,000(0 l,i 2,080.00
Depreciation oi portion of building occupied
by power plant ($132,200(3)2%) 1.322.00
Period Y'ear
$1,231.15 $2,107.81
46S.92 906.83
S.2S7.S0 16,220.00
2,369.70 4,352.70
34.S12.2S 68,788.68
260.00 500.00
362.00 2.362(H) 4,724 (HI
7,086.00
7.0S6.0O 14,172.00
2,080.00 4,160.00
1.322.00 2.644.00
Total.. $58.29(1 17 $60.279.85$1 18,576.02
* Boiler make-up water only.
DATA AND RESULTS OF BOILER PLANT— EVAPORATIVE TEST
Total number boilers in battery. 5 at 4tXI-hp. capacity.
Number boilers used in teat, 3
Kind of fuel. Illinois coal, Carterville district. No. 3 washed nut.
Kind of furnace, combination water and fire-tube boilers manufactured by I \ one
Bros., Depere, Wis
(bate surface. 3x60= 1 SI 1 ft ; 3 X 2600= 10.S00 sq.ft.
TOTAL QUANTITIES
Dale ,„' trial fune 28, 191 1
Duration of trial 22 hours
Weight of coal as fired 105,078 1b
Percentage of moisture in coal ''^l'
Total weight of ilrv coal consumed 99,508 lb
T,,lal ash and refuse 10,800 lb
Percentage of ash and refuse in drv coal 10.B
Total weight of water fed to the boiler 718,437 lb
Water actually evaporated, corrected for moisture in steam 715,204
Factor of evaporation „ ■ ;. ' "A,"'
Equivalent water evaporated into dry steam from and at 212 ileg 1 749,96! lb
January 12. 1915
i'o w e r;
65
Hourly Quantities
Dry coal consumed per hour
Dry coal per square foot of grate surface per hour 25.13
Water evaporate*! per hour corrected for quality "1 Bleam ;t2..">n'.<
Equivalent evaporation per hour from and at 212 cleg 34,089
E luivaleur evaporation per hour from and :ii 212 d
water-heating surface
Vverage Pressure-, Temperatun
pre-sur.- bj gage 150 lb Jrer -'I In
Temperature of feed-water entering boiler 212 deg.
Temperature of escaping gases from boiler '
Force of draft between damper and boiler l 11 in. water
percentage of moisture in steam. 0.45
ill -power
Horsepower developed
Builders' rated horsepower
Percentage of builders' rated hors.-pr.wer s_' ;:
Ecoi
r apparently evaporated
as fired 6.83
Equivalent evaporation from and at 212 deg. per pound of coal as tired . ,7.13
Equivalent evaporation from and at 212 deg. per pound of dry coal 7 .".1
Equivalent evaporation from and at 212 deg. per pound of combustible B 15
Cost of Evaporation
C>st of coal per ton of 2000 lb. delivered in boiler-room $2 90
Cist of coal required for evaporating 34J lb. of water from and at 212 deg
equivalent to ere- boiler horsepower 0.69
Readers (should note the editorial in the Nov. 3 issue
of Power, on page 648, under the heading of "Small
Leaks and Big Ones." The writer of that article not only
shows his ignorance, but the tone of the article all the
way through shows his disposition to injur..' a person
with whom he was not acquainted and knows nothing
of his ability whatsoever.
Note under heading of "Engineering Data" ending
Fefi. 28, 1911, that the average evaporation for the year
equals 6.8 lb.; also that when good coal wa< purchased
in February, mil. ami October, 1910. the evaporation
averaged 8.61 lb. coal as tired.
J. E. Lawrence.
Chicago, 111.
''av.cM.edl B©I31es*
All our asbestos-packed blowoff eoeks were leaking bad-
ly, because the packing was worn ami the stems cut.
As new packing would cost within 30 per cent, as much
as new cocks and believing that a good grade of babbitt
would do just as well if not better, a mandrel was made,
a set of cocks babbitted, the stems turned, ground in and
the cocks placed in service. These worked satisfactorily
and the others were repaired in the same way. The job
was done by our own men and at much less cost than if
sent to the factory.
It is over six months now, and they are still tight.
J. McL. But;xs.
Dover. X. J.
ss
Tlhe Faressugiira Hs a Cfeesimast
Chemistry itself is without sin. but the sins "I' chem-
ists are many. I note with interest a letter on this sub-
ject in the issue of Dec. 22, page 880. It is to !»• re-
gretted that such a mistaken statement as "air is com-
posed of hydrogen, oxygen and nitrogen" should have
been allowed to go unchallenged, as it is a common one.
It should lie remembered, even by one who is not a prac-
tical chemist, that the air consists chiefly of nitrogen and
oxygen, with some inactive argon, and some active car-
bonic-acid gas and water vapor.
I suppose the time will come when everyone will know
more of the common facts accurately. Such a mistake
is not only to In- regretted, but it tells us that we must
fight the battle fur edn. ation again and again, of course.
air should contain any hydrogen, then the air would
itself be not merely a supporter of combustion, but would
be partly combustible, which, however desirable, is no1
the ca-e.
I real lesson is that chemistry is something which
is fundamental to almost every line of business and man-
ure, and we should all learn to use it as it should
tsed, with safe ami sane common-sense. Let the
eternal battle-royal go on in the gram] campaign of edu-
cation. .Make fun of chemists, as we fully deserve, but
treat Chemistry will : she can speak for herself.
Charles s. Palmer.
Newtonville, Ma
[The original was in error in a sense for it did not
state that the hydrogen was not present as free hydrogen,
hut combined with oxygen in the form of vapor, often
augmented by the use of steam jets. — EnrroR.]
ffls-iriijgaiae
In the Oct. 20 issue is an article on a self-contained
steam plant which is interesting as a relic. The Buckeye
Engine Co. had a similar idea ami built a self-contained
plant called the "Printers' Engine." It was made
in sizes from 1% to 15 hp. Recently some drawings
winch were made in 1872, showing the cylinder set in the
The type
successful
Prixteiis' Engine as Built ix 1873
head of the boiler, were found at the works,
of engine illustrated herewith, however, was
and a number of them was sold.
I). J. Mi Cdxxell,
Salem. Ohio. Buckeye Engine Co.
[The circular from which the accompanying illustra-
tion is produced is dated is;.",. — Editor.]
<;,, Po W E R Vol. 41, X.i. 2
^J b L L 1 1 L L 1 1 1 1 1 L 1 1 ! 9 111 1 1 11 1 M 1 L 1 1 1 1 1 1 1 1 1 1 ! ■ 1 r M 1 1 1 1 i 1 1 ( ] 1 < 1 1 1 9 1 L 1 1 1 1 1 1 1 M 11 1 1 1 1 1 1 1 1 1 L t ) L L 1 1 1 L - U I ! i r L I L L F 1 1 1 k 1 1 1 1 L 1 1 b I L L I N 1 1 1 1 1 M 1 1 M 1 1 1 1 1 M 1 1 III 1 1 : M 1 1 U 1 1 1 1 1 1 1 1 1 1 1 U L L 11 L 1 1 < 1 1 i 1 1 1 1 1 1 1 1 1 1 1 1 1 U . < : ! ! I . '. : ^ . <^ 1 ' 1 1 1 1 < I j 1 ■ j 1 1l1lllllllllll[lll!!lttllllllllll!l!lllllltnnilllllllNllll!llll!llllllll11
^mrfimi(
>©* Stod^
lesBas ass rowes5"
Design--XIII
Comparing Steam Requirements with Available Ex-
haust
It was stated in the first article of the series that in
designing a combined power and beating plant a compar-
ison should be made between the steam requirements and
available exhaust which should cover with a fair degree
of accuracy the entire heating season.
In a general way, it is usually economical to employ
the exhaust steam for heating purposes and to design the
power plant with reference to that arrangement. Or,
stated in another way. it is generally advisable, under av-
erage conditions, to install power and lighting plants in
large buildings and to utilize the exhaust for heating.
While this may be true ordinarily, the amount of saving
will depend upon a number ol conditions which may vary
widely in different cases. Among these may be mentioned
length of heating season, average winter temperature, type
of engines used, method of heating, cost of fuel, water,
labor, etc., and also, of the most importance, the relation
between the steam required for heating and the available
exhaust at different parts of the day.
The total exhaust from a plant in twenty-four hours
may be equal to or exceed the beating requirements dur-
ing the same length of time, but if it is not distributed
so as to be utilized, a large amount may be thrown away
at certain parts of the day which must be made up at
other times by live -team taken from the boilers, from
this it may be seen that total amounts of steam for the
day are often misleading and a special study should be
made of conditions from hour to hour (where there is
much variation of load) for representative days of a con-
siderable number of periods throughout the heating sea-
son. In the present case the available exhaust was as-
sumed to be practically uniform throughout the year. and.
furthermore, was found to exceed the heating require-
ments, so that a comparison of this kind was not neces-
sary.
In other plants, especially those in office buildings,
hotels, etc., where lighting and elevatoT service form a
large part of the load, conditions will be found much more
variable and tables or curves for comparison should always
be prepa red.
Power and Heat Requirements
In any given case the first step is to make up a schedule
which shall represent the power and heat requirements
for the heating season.
A good wu\ In obtain average conditions is to divide
the season into seven equal periods, extending from the
middle of October to the middle of May, ami from the
weather records of previous years obtain the average tem-
perature of each of these periods. If the plant is oper-
ated daytimes only, use the day temperatures, but if it
i- operated both day and night, as in a large hotel, then
make up two I i ^t -. one of average temperature- from (i
o'clock in the morning until ii at night, and the other for
the remaining twelve hours. Designate them "day tem-
peratures"' and "night temperatures."
Next, make a list of all purposes for which steam is
required in the building exclusive of that used for power.
These will vary in different cases, but they will ordinarily
include one or more of the following : Heating, ventilating,
hot water for lavatories and baths, cooking, laundry ser-
vice, sterilizing, mill work such as drying, washing, fin-
ishing, etc., and dry kilns.
In a new plant the weight of steam required for each
of the foregoing purposes per hour, with the exception of
heating and ventilating, may usually be obtained from
those installing the kinds of apparatus to be used. If the
17000
16000
15000
14000
13000
E 12000
a> II 000
■+-
"> 10000
c 7000
o 6000
5000
4000
Mailable Exhaust
3000
2000
'
--
---
--Steam Requirements
~|
1000
0
0
E
S
l(
) I
1
I
I
-
,
i
8 9
Hours of the Dctv """"S
problem concerns the installation of a power plant in
building already constructed and in use, tests should be
made to determine the weight of steam actually required..
In addition, the particular hours of the day during whi
steam is required for the various purposes should lie noted
as well as the weight used. The requirements for heating
and ventilating may usually be computed with sufficient
accuracy from the data given in previous articles of tin
present series, supplemented by certain corrections to tx
noted presently.
The beating system for a building is commonly pro-
portioned for the coldest weather to which that partieulai
locality is subject. If now the apparatus he provide,
with a system ol' automatic control, which shall gage 'In
heat supplied tu actual requirements, the weight of stean
used per hour will vary directly as the difference hetweei
the inside and outside temperatures (neglecting the erl'oi
of high Winds) and will change with each variation ol
outside temperature throughout the heating season. If,
on the other hand, the entire radiating surface is kep
turned on at all time- or the heating plant is run at it-
Ja
191!
P o W EE
Full capacity, the weight of steam used per hour will be
practically the same for all outside temperatures, with ;i
system of direct radiation, provided the inside temper-
ature is maintained al <0 deg. by opening the windows.
As a matter of Fact, neither of these conditions ordinarily
prevails, although the Former is very nearlj approached
with tin* best systems of pne ttic control.
Tn approximate the steam requiremeni For heal ing with
different outside temperatures, the weight of steam used
per hour in zero weather must be multiplied by a Factor
corresponding to the actual outside temperature, and
this in turn must he corrected For the type of temperature
regulation employed. Assuming that the plant is de-
signed For a minimum outside temperature of zero and
the normal inside temperature of 70 deg., and that the
system is accurately controlled to maintain this inside
temperature without opening the windows or admitting
cool air, the proportion of heat required for varying out-
side temperatures will he found in Table I.
TABLE 1 HEAT REQUIREMENTS
mperature, deg.
Proportion
quired,
of lieal i
compari
+21) + 30 +4(1 +50 +Ii0 +7(1
0 43
II 15 II 00
if steam is required for heat-
intside temperature of
aditioDE
For example, if 1000 lb
jng a given building with
i ro only.
1000 X 0.72 = 720 lb.
will lie required when it is 20 deg. above, or
1000 x 0.4:5 = 130 lb.
at III deg., etc. The next step is to assume certain 'ac-
tors to offset the steam wasted when different means of
temperature regulation are employed. These factors can
only he estimated, but For average conditions it may be
assumed that with the best systems of automatic control
the results given in Table I will he obtained. With
Fori ed hot-water circulation these should he multiplied by
1.2; with vacuum systems by 1.3, and with low-pressure
gravity systems by 1.4.
For example, if loot) lb. of steam is required per hour
ill zero weather with a low-pressure gravity system,
1000 X 0.43 X 1-4 = 602 lb.
will be required when it is 10 deg. above zero. In other
words. 10 per cent, more radiation will be in use than is
actually required for heating the building and the sur-
plus heat will be wasted through open windows.
When ventilation is provided in large buildings by
means of fans, the temperature of the entering air is ac-
curately controlled, and Table 1 may be made use of, the
same as for automatically controlled direct radiation.
For example, if the weight of steam required for warming
the air for ventilation is 3000 lb. per hr. in zero weather,
it will be
3000 X 0.57 = 1710 lb.
when the outside temperature is -4-30 deg.
After having determined the weight of steam required
for all heating purposes for each hour of the average day
of the first period. Oct. lo to Nov. 15, the next step is to
estimate the average indicated horsepower required for all
power purposes for the corresponding period.
The power requirements will vary with the type of
building and will commonly include a portion of the fol-
lowing: Driving machinery, lighting, elevator service,
auxiliary pumps, refrigeration, ventilating fans, miscel-
laneous motors for kitchens, laundries, etc. As the power
load will vary at different hours of the day, each hour
should he taken up separately and the available exhaust
computed for comparison with the steam requirements
for heating during the corresponding hour. The total
indicated horsepower multiplied by the water rate of the
engine, and tin- result b\ 0.85, will give the available
exhaust. In making a full Aui\y of this kind of problem
the average day for each of the seven periods should he
similarly worked out and the results either tabulated or
plotted iii curves for easy reference. Having shown the
general method to he followed in such problems, it may
he well to illustrate it by working out a simple example
in detail.
Take the case of an office building requiring power for
lighting, elevator service, auxiliary pumps and fan motors,
and steam for heating, ventilation and hot-water service.
Suppose the maximum requirements for each are found
to he as follows: Lighting, 200 kw. ; elevator service, 300
i.hp. ; fan motors. 12 i.hp.; auxiliary pumps, 20 i.hp.
All items rated in indicated horsepower are referred to
the main engines and include the friction losses in the
van. mis machines. Let the period taken he From Dee.
15 to Jan. 15, when the lighting requirements are at a
maximum, and assume them to be as follows:
Hour of Daj Kw [.Hp. at Engine
6>.m. to 7 a.m. II) 18
7ai S a.m 50 S8
8 a.m. to 4 p.m 70 124
I p.m. to (', p.m. ....... 20(1 350
fi p.m lo II p m 40 70
In making out this schedule it has been assumed that
each kilowatt delivered by the dynamo requires 1.75 i.hp.
at the engine. The schedule of elevator service is assumed
to he as follows :
Hour of Day I.Hp. at Engine
7 a.m. to 8 a.m 100
8 a in I" II a in 300
II a in lo 12 noon 150
12 noon to 2 p.m 300
2 p.m. to I p.m 10(1
I p.m. to .I p.m 300
5 i' in bo ii p.m 1.50
n o in in 7 p.m -VI
7 p m I.. II p m 10
The various auxiliary pumps, including those for hot-
water circulation for heating the building, are run con-
tinuously From o a.m. until o p.m. and require approxi-
mately '.'0 i.hp. at the main engines. Ventilation is pro-
vided for the first-floor stores and special offices and the
fans are run from S a.m. till 5 p.m., at a uniform load
of 12 i.hp. at the engine.
As the exhaust will he utilized for heating purposes,
simple high-speed engines will he used having a water rate
of approximately 30 lb. per hr. per i.hp., of which about
30 X 0.8r, = 25 lb.
will be available in the exhaust for heating purposes.
It is now possible to make out a schedule covering the
entire day. giving the total indicated horsepower for all
purposes and the pounds of available exhaust for each
lion)-.
TABLE 2 SCHEDULE OF AVAILABLE EXHAUST
I.Hp. for Pounds per Houi
Different Purposes of Available Ex-
Hour of Day ABC D Total I.Hp. baust (I.Hp. z 25)
8 to 7 20 + is 38 950
7 to 8 20 + 88 + 100 206 5,200
v In 0 20 + 124 + 300 + 12 toll 11.400
V) to 10 20 + 124 + 150 + 12 301. 7.0*
in m 11 211 + 124 + 150 + 12 3111'. 7.650
11 in 12 20 + 124 + 150 + 12 306 7,650
12 to 1 211 + 124 + 300 + 12 156 11,400
1 to 2 211 + 124 + 300 + 12 456 11,400
2 to 3 20 + 124 +100+12 250 6,400
3 to 4 20+124+100+12 256 6,400
4 to 5 20+350+300 + 12 682 17,050
:, to 6 20 + 350 + 150 520 13.000
6 l" 7 20+70+50 141) 3.500
7 to 8 20 + 70 + in UK) 2,500
s t,. o 20 + 70 + 1() iiki 2,500
Iii the above schedule column A represents power for
GS
POWE E
Vol. 41, No. i.
auxiliary pumps; B. electric lighting; C, elevator^ ; and
1>. ventilating fans.
The next step is to prepare a similar schedule for the
i eating requirements. Suppose the computations show
the total heat necessary for warming the building in zero
weather to be o. 700,000 B.t.u. per hr., and for ventilating
purposes 2,000,000 B.t.u. per hr. Furthermore, suppose
that the weather records for the past five years show the
average day temperature to have been +20 deg. for this
period. Let the circulating pumps for the heating system
be started at 6 a.m. and stopped at 9 p.m., and assume
that two hours are required for warming the building
up to "0 deg., so that from 6 to 8 in the morning during
this month the plant will be run at its full rapacity re-
gardless of the outside temperature. Although the build-
ing is to be warmed with hot water, the steam require-
ments will be the same a> though it were condensed in the
radiators instead of in a special heater.
Taking the latent heat of exhaust steam as 970 and the
factor for hot-water regulation as 1.2; we have the ■fol-
lowing conditions and results: During the period from
6 till S a.m. the total capacity of the heating plant will
be required and utilized, or
5,700, „ „
= 5876 lb.
970
or practically 5900 lb. of steam will lie used per hour.
For the remainder of the day this will amount to
5900 X 0.12 X 1.2 = 5091 lb: per hr.
Heat for ventilating purposes amount- to
2,000,000 X 0.72 X 1.2 = 1,728,000 B.t.u.
1,728,000 . .
,)7(J — =..1781 lb. pa- hr.
I rem 8 a.m. till 5 p.m. Buildings of this kind are usually
Mipplied with a hot-water storage tank so that any va-
riation in the demand for hot water during the day is
cared for in this way.
In the present case, steam will be on the tank contin-
uously from 6 a.m. till 9 p.m. and it may lie assumed that
150 lb. of steam per hour is required for this purpose
throughout the day. The data are placed in tabular form,
the same as for the power requirements, in Table 3.
TABLE 3. SCHEDULE OF STEAM REQUIREM] N I -
Lb. Steam Lb. Steam Lb. Steam Total Steam
Hour per Hr. for per Hr. for per Hr. for Requirements,
of Day Heating Ventilation Hot Water Lb. per Hr.
6 to 7 5,900 150 6,0.50
7 to 8 5.900 150 6,050
8 to 9 5,097 1,789 150 7,036
9 to 10 5,097 1,789 150 7,036
10 to 11 5,097 1.7S9 150 7,036
11 to 12 5.097 1.789 150 7,036
12 to 1 5,097 1,789 150 7,036
1 to 2 5.097 1.789 150 7.036
2 to 3 5,097 1,789 150 7,036
3 to t 5,097 1,789 150 7.036
It,. :, 5.097 1.7S9 150 7,036
5 to 6 5.097 1.50 5.247
6 to 7 5,097 150 .5.247
7 to S 5.097 150 5,247
8 to 9 5.097 150 5.247
As a matter of fact, the outside temperature will vary
more or less during the day. but as this is so irregular in
its action it is difficult to allow for it unless the number
of hours for each temperature is tabulated. For approx-
imate work it is usually sufficiently accurate to use con-
stant temperatures throughout the day and night per-
iods. In the present case a constant temperature has been
assumed for the entire heating period from 6 a.m. till
!) p.m. Table 4 compares steam requirements and avail-
able exhaust and shows the weight of live steam required
and exhaust wasted for each hour during the day.
TABLE 4. SCHEDULE OF COMPARISONS
St
earn Re-
Available
Live Steam
Exhaust '
of Day
quirements, Lb.
Exhaust, Lb.
Used, Lb.
Wasted, Lb
to 7
6,050
950
5,100
to 8
6,050
5,200
850
to 9
7,036
11,400
4,364
to 10
7,036
7.0.5(1
014
to 11
7,036
7,650
614
to 12
7,036
7,650
614
to 1
7,036
11,400
4.364
to 2
7,036
11,400
4,364
to 3
7,036
6,400
636
to 4
7,036
6,400
636
to 5
7,036
17,050
10,014
to 6
.5,247
13,000
7,753
to 7
5.247
3,500
1.747
to 8
.5.247
2,500
2,747
to 9
.5.247
2,500
2,747
Referring to Table I. it is seen that while the avail-
able exhaust for the day is
11 1,650 - 96,412 = 18,238 lb.
more than the total steam requirements for heating, it is
so distributed that 32,701 lb. are wasted and 1.4,463 lb.
of live steam must be taken from the boilers to make up
the deficiency. This illustrates the point noted at the
beginning of the article — that total steam quantities for
the day should not lie relied upon when making compari-
son of .-team requirements and available exhaust. To
make the comparison complete, this same process should
be gone through with for an average day for each month
of the heating season.
In large plants, where there is considerable variation
in power and heating conditions from month to month,
it may be advisable to take shorter periods, say every week
or ten days. The accompanying diagram is a plot of the
heat requirements and the available exhaust. This shows
at a glance the relation of one to the other throughout
the day.
ScneEace
The 66th meeting of the American Association for the
Advancement of Science held at Philadelphia, Penn.. Dec. 2*.
1914, to Jan. 2, 1915, was attended by 1500 to 2000 members
and guests corning from every part of the United States.
Nearly every university. Federal department, state or city
government which employs scientific investigators was repre-
sented and the Philadelphia meeting recently brought to a
close was undoubtedly the most successful in scope of sub-
jects and in point of attendance of any since the organization
of the association in 1S47.
There are 12 sections of the association, comprising mathe-
matics and astronomy, physics, chemistry, engineering, geol-
ogy and geography, zoology, botany, "anthropology and psy-
chology, social and economic science, physiology and experi-
mental medicine, education, agriculture.
The programs of the different sections each included any-
where from live to one hundred addresses and communications
in their respective fields of scientific research. The sections
and 24 affiliated societies held their principal sessions in the
various halls, lecture rooms and laboratories of the University
of Pennsylvania, which afforded admirable accommodations.
I lr Charles W. Eliot, president emeritus of Harvard Uni-
versity, was elected president of the association for the
ensuing year. At the first general session the retiring presi-
dent, Dr. Edmund D. Wilson, in delivering his annual address,
said that "the scientific method is the mechanistic method
which prod ties practical results. The moment we swerve
from it by a single step we set foot on a foreign land."
Frederick \V. Taylor, one of the vice-presidents of the
association, presided at the sessions of the engineering sec-
tion which were held Dec. 30 and 31 in the Engineering Build-
ing of the university. Seventy-five papers and addresses were
presented on various subjects of industrial, hydraulic and
civil engineering, the latter including 30 papers on highway
construction and pavements.
The next regular meeting of the association will be held
at San Francisco, Calif.. Aug. 2 to 7, 1915. As this will be
during the Panama-Pacific Exposition, it is expected that the
meeting will be largely attended.
January l'.\ L915
P U \\" E
69
low Meter;
II y W. S. (.111 i :
SYNOPSIS — Description <</ " laboratory for test-
ing mi/I calibrating liquid flow meters by means <>f
direct comparison of like quantities, such as vol-
■umes, inches "/' water head, and rates /»'/• unit
time.
The laboratory herein described was designed and built
to facilitate the investigation and testing: of liquid flow
meters, with special reference to those of the V-notch weir
type. This type consists essentially of a rectangular chamber
containing a vertical dividing wall with a V-notch weir plate
attached to the upper part. On one side is the "approach"
chamber provided with suitable baffles, and on the other,
the "outflow" chamber which receives the discharge of the
notch, and from which water passes to boiler feed pumps or
other places of delivery. This meter is provided with an
autographic recording device, giving a continuous record
from which the instantaneous rate of flow may be read,
While also permitting a continuous integration of quantity.
The indicating, recording and integrating instruments will
be best understood by reference to Fig. 1. A float in either
muse Devices
the approach chamber or a chamber in communication there-
with, bears a vertical stem, actuating (by means of a cable
and drum) a revolvable cam, which is adapted to displace
a pen carriage or integrating train equal distances for equal
increments in the rate of flow. For convenience in manu-
facture and use, it is desirable that one standard height of
chart be employed for all capacities, and that this chart
be subdivided decimally. With arbitrarily selected weir-
notch angles this might be attained by cutting a different
cam for each capacity, but it is much easier to use one
standard cam, embodying the relation between the rate of
flow and the head of water on the notch, and to accomplish
the adaptation to different rates of flow by varying the
diameter of the cable drum and the angle of the notch
itself; thus making it necessary to establish accurately the
relation between the coefficient of the notch and the angle.
The method decided upon was to construct a master flow
meter so arranged that the rate of flow could be maintained
'Excerpts from a paper before the American Society of
Mechanical Engineers, at New York, Dec. 4. 1914.
accurately at any desired value for long periods: and after
having determined with precision the performance of this
standard, to use it as a means of measuring the flow through
the meters which it is desired to investigate.
By this means of direct comparison, a degree of accuracy
can be secured in tin- meter under test practically equal to
that of the standard. Such a standard having once been
accurately calibrated, disturbing influences arising from the
effects of proportions of the channel of approach, conditions
Pit
General View of Meter-Testing Plant
of surfaces, form and material of notch, directions and inter-
ference of currents of flow in the channel of approach, etc.,
• an be ignored.
It is estimated that by this method greater accuracy
can be obtained in a run of one-half hour at a low head than
would be possible in a run of fifteen hours at the same head,
using either volumetric or gravimetric methods.
DESCRIPTION i'I'' APPARATUS
As shown in Figs. 2 and 3, the testing plant has a large
storage tank from which the water is drawn by a pump
and elevated to a supply or constant-head tank at the highest
level, its purpose being to supply water to a discharge orifice
at a constant head so that the rate of flow through the
standard notch may be maintained invariable at any desired
capacity.
From the constant-head tank the water passes to the
standard-notch tank, thence flows over the calibrated notch
into the meter under test, whence it is discharged to the
storage tank to circulate again.
During the preliminary work on the calibration of the
standard notch, instead of passing from the standard notch
to the meter under test, the water flowed alternately to
either of two volumetric measuring tanks, from which it
discharged into the storage tank to resume its course.
In view of the necessity for permanent maintenance of
conditions under all circumstances, the entire plant was con-
structed with the utmost regard to permanency and rigidity.
The foundation consists of a concrete slab approximately 24
ft. long by in ft. wide, carried to solid clay soil and reinforced
in all directions by 1-in. rods.
The storage tank rests directly on the concrete foundation
and holds a little over 1000 cu.ft. of water. The supply to
the pump is through an 8-in, opening located with its center
,11
PUWJi II
Vol. 41. V .
about S in. above the bottom of the tank (to eliminate sludge
which might accumulate on the bottom), and 12 in. from the
vertical center line of the end of the tank. It is also supplied
with a 3-in. drain at its lowest point and with a system of
steam pipes whereby the water may be heated to the desired
temperature.
Overflow trough to gtYe
constant lever
Fig. 3. Elevation of Testing Plant
The pumping unit is an S-in. single-stage, centrifugal
pump about 4 ft. from the end of the storage tank. It is
gear-driven by a single-stage steam turbine, and has a
capacity of about 120 cu.ft. per min. against the head of the
highest tank, which corresponds to a flow of about 450,000 lb.
per hr.
The outlet from the constant-head tank is a S-in. line
taken from the bottom and as close to the side as possible.
This arrangement was adopted after experiments looking
toward the prevention of a swirling motion within the tank.
The maintenance of a practically constant head in this
tank is essential to a constant flow through the system. This
is accomplished by the installation of an overflow weir
consisting of a rectangular trough S ft. S in. long, having
inflow edges or weirs on both sides. These edges are con-
structed of metal and were carefully brought into a horizontal
plane so that the discharge would be uniform throughout
their length. The overflow at these edges is carried by a
4-in. pipe line back to the storage tank, this line being
provided with a %-in. bypass discharging into open funnels
on both the standard notch level and the observation room
level so that the observer may constantly watch the overflow
and thereby judge of the constancy of the head.
The approximate amount of water in the constant-head
tank is indicated by a float to which is attached a chain
passing o,-er sheaves and extending to the pump room with
pointers at each level.
The outlet pipe for the constant-head tank into the stand-
ard-notch tank contains a 6-in. valve for roughly setting the
larger flows and a 2-in. valve in a bypass carried around the
6-in. valve for fine adjustment. The stem of this 2-in. valve
is carried down to the observation station so that the flow
may be accurately controlled from that point.
Every precaution has been taken to prevent change in
shape or position of the standard notch. It rests on a
structural steel platform supported by heavy, rigidly braced
columns carried outside the volumetric measuring and storage
tanks directly to the foundations, the column loads being
distributed on the foundation by two 15-in. I-beams, grouted
in. The standard V-notch is approximately 22U. in. high
by 11 '4 in. wide at the top, and its full capacity at ls'i in.
head is roughly 110 cu.ft. per min.
The standard-notch tank is divided into two compartments
by a rigid partition 1 ft. from the end opposite the notch
and ending 1 ft. above the bottom. The supply line dis-
charges behind this partition 2 ft. below the surface of the
water, and the water finds its way under the partition, spreads
out over the bottom of the tank and rises through a perforated
baffle having approximately 2000 holes Si in. square. This
arrangement has resulted in a quiet surface of approach,
even at the highest rates of flow.
It was not necessary to find the apex or zero level of
the standard notch with extreme precision, it being necessary
only to provide a reference point from which measurements
could always be taken, and which. would be immovable with
respect to the notch itself. This reference point consists of
a hook gage securely soldered to the notch with its point in
a plane normal to the plane of the notch through its vertical
center line and y* in. away from it. The level of the water
above the zero level is read by a second adjustable hook
gage attached to the opposite end of the tank.
As any tilting of the tank would not only change the
cross-section of the stream issuing from the notch, but also
the relation between the hook gage by which the level is
read and the notch, the care in supporting the tank is further
checked by means of special gages to indicate any deflection
in the tank or supports. These special gages consist of four
glass tubes with three reference lines, spaced 9 in. apart,
etched entirely around each. The four gage glasses are
firmly attached at the four corners of the standard-notch tank.
The level of the water flowing through the standard-notch
is obtained by means of a specially designed hook gage
connecting with the still-water chamber. The special and
unusual construction of this hook gage arises chiefly from
the extreme range of height which it must cover and the
consequent possibilities of error resulting from differences
in temperature between the various parts of the gage itself
at various times, and also between the water column within
the gage tube and the temperature of the water in the still-
water chamber. To eliminate the effect of temperature
changes in the gage itself, the elements were so constructed
that expansions due to increased temperature would tend to
compensate each other. To eliminate the effect of differences
of temperature between the two water columns, the hook
gage tube was jacketed by flowing water taken from the
same source of supply as that to the still-water chamber.
The hook itself has a 60-deg. point and is constructed as
shown in Fig. 4.
Fig. I. Showing Akbangement of Hook <i\ge
The register of the point of the hook with the surface
of the water is observed from below the water surface, in
which position it is possible to see both the hook itself and
the reflected image on the surface of the water. The hook
is at the water surface when the point of the reflected image
coincides with the point of the hook. Any deviation from
this position is observed as double the distance between the
point of the hook and the water surface, thus permitting
exactness in this observation, which is further promoted by
the fact that the reading is taken through a magnifying
Januarj I'.'. 1915
I'n v, e i;
■; i
ions and reflected downward and horizontally by a mirror
to the observation stalion, at which point a tour power
binocular is rigidly supported for observation. The hook is
illuminated by means of a frosted incandescent bulb.
Owing' to the number of readings to be taken and the
space covered by the plant, special means were necessary to
bring all observations and controls to a central observation
station. Fig". 5 is an interior view of the observation room
showing the desk from which observations are taken.
When running tests, it is necessary only to observe that
tin water level remains at the point of the hook and it is
not necessary to read the height of the hook gage on the
standard-notch tank during the progress of an experiment.
A similar hook gage is applied to the meter under test with
the addition of an extended shaft bringing the graduated
scale to the observation room where the operator can read
the height of water passing over tin- weir under test. This
reading is taken immediately above the eye pieces of the
binoculars through which is observed the coincidence of the
water surface and the hook.
It was determined aftei several experiments that tin'
hook and hook rod must be relieved of all strains and left
free to align themselves by gravity. While with the jacketed
' ■ :ads corresponding to these points and start the
circulation of water through the system. After bringing
the flow up to the desired head by manipulation of the control
valves, readings were taken at regular and frequent intervals,
until a sufficient number had been obtained showing uniform
conditions, to furnish data for the necessary computations
with assurance of reliability.
Fig. 5. Observation Room
arrangement it was never possible to detect a difference in
temperature between the water in the hook gage tube and
in the still-water chamber exceeding '.; deg. F. during the
course of a whole day, it is interesting to note the results
which might be obtained from an unjacketed gage Without
the jacket water it was found that a difference of L'O deg. K.
(from 50 to 70 deg.) was entirely possible and effected a
vertical head of 30 in. of water. The reading of the gage
under such conditions would be 0.04.S in. in error.
In investigating the effects of temperature changes on the
lia its of the gage it is to be noted that the vertical sheave
support in its expansion will compensate for the elongation
of the cable due to temperature, and that the expansion of
tin- drum will tend to compensate for the elongation of the
hook rod between the point of the hook and the attachment
of the cable.
In preparing for the calibration of the standard notch,
a curve was plotted, indicating the ideal conditions of flow,
which the experiments would approximate. This curve was
then divided into sections so that these could be separately
plotted from the empirical data obtained to a much larger
scale. After having mapped out the points it was desired
to plot on the curve it was necessary only to set the hook
laiiaft Hotl &<a>
ncs
A recent bill passed by the citj council of Seattle to per-
mit tin- municipal lighting plant to extend its service beyond
the city limits ti» serve rural districts has been vetoed by the
mayor. The council refused to pass the bill over the mayor's
veto. In refusing to adopt the plan of extending the city
lighting system to outlying communities, Mayor Gill said in
part :
"To say that the .Seattle lighting plant is a money-mak-
ing concern in the sense that it earns money for the gen-
eral purpose of reducing taxation is wrong. From its in-
ception the lighting plant has controlled the rates of this
city. It has saved our business men, taxpayers and residents
many millions of dollars and will continue to do so unless it
is brought into disrepute and made a political plaything.
"I "nilcr this theory of outside extensions there is no tea
son why the city of Seattle should not engage in any other
commercial business and conduct grocery stores, drygoods
stores and other profit-making concerns. All there is em-
bodied in this bill is pure socialism and opportunity given to
settle the grudges of certain persons arising from real or
imaginary grievances against a private corporation.
"The financial condition of our lighting plant at the pres-
ent time is due to gross financial mismanagement by tin-
council for the past three years. The councilmen refused to
c ply with the recommendations of former Chief of Police
Griffiths and myself, and light downtown alleys, giving as an
excuse that they had no money, although they are now pre-
paring to become 'wet nurse' for the suburban districts out-
side the city limits, and are far worse off financially now
than then. I have always maintained that the plant should
seek a fair return on the money invested and the amoun'
so earned be expended within the limits of the city to the
end that all our people should have light at the lowest cost
consistent with good business management.
"The tax rate of the city- during the past few years has
increased at a highly unprecedented rate, and we have nothing
to show therefor except a street car line which was not in-
tended to accommodate the public and which did not even
accomplish the purpose of is principal promotors. As a matter
of fact, there is no money in the light fund."
IR<es©ai5rc3h Felllowslhaps at;
To extend and strengthen the Held of its graduate work
in engineering, the University of Illinois has since 1907 main-
tained ten research fellowships in the engineering experiment
station. These fellowships, for each of which there is an
annual stipend of $500, are open to graduates of approved
American and foreign universities and technical schools. Ap-
pointments are made and must be accepted for two consecu-
tive collegiate years, at the expiration of which period, if
all requirements have been met, the master's degree will be
granted. Not more than half of the time of the research fel-
lows is rquired in connection with the work of the department
to which they are assigned, the remainder id' the time being
available for graduate study.
Nominations to fellowships, accompanied by assignments
to special departments of the engineering- experiment station.
hi made from applications received by the director of the
station each year not later than the first day of February.
These nominations are made within the month of February
by tin- station staff, subject to the approval of the faculty of
tin graduate school and the president of the university. Ap-
pointments are made in March, and they take effect the first
day of the following September.
Nominations are based upon the character, scholastic at-
tainments, and promise of success in the principal line of
study or research to which the candidate proposes to devote
himself. Preference is given those applicants who have had
some practical engineering experience following their under-
graduate work. Research work may be undertaken in archi-
tecture architectural engineering, chemistry, civil engineer-
ing, electrical engineering, mechanical engineering, mining
engineering, municipal and sanitary engineering, physics, rail-
r 0 \V E R
Vol. 11. No.
way engineering, and in theoretical and applied mechanics.
The work of the station is closely related to that of the college
of engineering, and the heads of departments in the college
constitute the administrative station staff. Investigations are
carried on by the members of the staff and other members of
the instructional force of the college of engineering, uy spe-
cial investigators employed by the station, and by the re-
search fellows. Four vacancies are to be filled at the close
of the current academic year. Additional information may-
be obtained by addressing the director of the engineering ex-
periment station. University of Illinois, Urbana, 111.
&
lEleefora IS cg*.&£© e&
Plans for the electrification of the Puget Sound lines of
the Chicago, Milwaukee & St. Paul Ry. have now been com-
pleted and contracts let to the General Electric Co. for the
electric locomotives, substation apparatus and line material,
and to the Montana Power Co. for the construction of the
transmission and trolley lines. This initial electrification of
113 miles of main line between Three Porks and Deer Lodge
is the first step toward the electrification of four engine
divisions extending from Harlowton, Mont., to Avery, Idaho,
a total distance of approximately 440 miles. Later on, it is
understood, the electrification will extend to the coast.
The Montana Power Co. covers a large section of Montana
and part of Idaho with its network of transmission lines,
which are fed from a number of sources of which the principal
ones are:
Madison River 11,000 k\v.
I 'anon Perry 7,500 kw.
Hauser Lake 14,000 kw.
Big Hole 3,000 kw.
Butte (steam turbine) 5.000 kw.
Rainbow Falls 21,000 kw.
Small powers aggregating 7,390 kw.
Total developed 6S.S90 kw.
Further developments, part of which are under construc-
tion, are:
Great Falls 85,000 kw
Holter 30,000 kw.
Thompson Falls 30,000 kw.
Snake River 20.000 kw.
.Missoula River 10.000 kw.
Total 175,000 kw
Total capacity developed and undeveloped 244,000 kw
The several power sites are interconnected by transmission
lines, operating at 50,000 volts for the earlier installations
and at 100,000 volts for later installations.
The railway company will purchase power at a contract
rate of $0.00536 per kw.-hr., based on a 60 per cent, load
factor. It is expected under these conditions that the cost
of power for operating the locomotives will be considerably
less tlian is now expended for coal.
In order to connect the substations with the several feed-
ing-in points of the Montana Power transmission lines, a
tie-in transmission line is being built by the railway company
•hat will permit feeding each substation from two directions
and from two or more sources of power. This transmission
line will operate at 100,000 volts.
The immediate electrification will include four substations
containing step-down transformers and motor-generator sets
with necessary switchboard apparatus to convert 100,000-volt,
60-cycle, three-phase current to 3000 volts direct current. This
is the first direct-current installation using such a high
potential as 3000 volts, and this system was adopted in prefer-
ence to all others after a careful investigation extending
over two years.
SUBSTATION'S
The substation sites of the electrified zone provide for
an average intervening distance of approximately 35 miles.
The substations will be of the indoor type, with three-
phase, oil-cooled transformers reducing from 100.000 to
2300 volts, at which potential the synchronous motors will
operate. The transformers will be rated 1900 and 2500 kv.-a.
and will be provided with fout ;% per cent, taps in the
primary and 50 per cent, starting taps in the secondary.
The motor-generator sets will each comprise a 60-cycle
synchronous motor driving two 1500-volt direct-current gen-
erators connected permanently in series for -3000 volts. The
fields of both the synchronous motor and direct-current
generators will be separately excited by small generators
direct-connected to each end of the motor-generator shaft.
The generators will be compound wound, will maintain
constant potential up to 150 per cent, load and will have a
capacity for momentary overloads of 300 per cent, normal
rating. To insure good commutation on these overloads, the
generators will be equipped with commutating poles and com-
pensating pole-face windings. The synchronous motors will
also be utilized as synchronous condensers, and it is expected
that the transmission line voltage can be so regulated thereby
as to eliminate any effect of flie fluctuating railway load.
WaJer^Fowe? Bills 3b>e£<os°e
jiress
There wen- two bills introduced during the session of <'"ii-
gress just closed, each of which is of considerable importance
and will have a controlling influence over future water-power
projects if enacted into law. On careful reading, there seems
to be no conflict of purpose at present or likely to arise from
the enaction of both bills.
The Adamson bill deals exclusively with navigable waters,
consequently with projects of considerable magnitude, while
the Ferris bill deals with water-power development within the
public lands and reservations of the United States. The Adam-
son bill, the first introduced, is an act to amend "An act to reg-
ulate the construction of dams across navigable waters," ap-
proved June, 1906, amended June, 1910, and is in general terms
as follows: Authority is vested in the Secretary of War and the
chief of engineers of the War Department to grant persons
of proper status the right to construct and maintain a dam
across or in any of the navigable waters of the United States,
after obtaining approval of the plans, on condition that such
persons shall maintain without expense to the United States
such locks, booms, sluices or other structures which may then
be deemed necessary. Also in case of future necessity, the
grantee must furnish free water power or power generated
from water power for the use of the United States for such
construction. Provision is made for certain reimbursement to
the United States for expenses incurred with reference to
the project and also for funds to restore conditions whenever
it shall be determined that navigation has been injured. It
specifically states that the interests of navigation shall be
paramount to the use of such dam for power purposes and
that the grantee at his own expense shall maintain necessary
lights and signals to aid navigation and such fishways as
shall be prescribed by the Secretary of Commerce.
That persons constructing or maintaining any dam, etc.,
shall be liable for damage to private property by overflow or
otherwise.
It shall be a misdemeanor punishable by a fine not ex-
ceeding $1000 a month to fail or refuse to comply with the
lawful order of the Secretary of "War, and if such failure
or refusal is continued, all rights shall be revoked by a
decree of the court. If such dam be declared an unreason-
able obstruction to navigation its removal may be ordered
at the expense of the grantee. The rights granted under this
act shall continue for a period of 50 years after the comple-
tion of the dam, and after the expiration of that time such
rights shall continue until compensation has been made
for a fair value of the property as Congress may deem wise,
unless revoked for cause.
After the expiration of 50 years, and on giving notice of
cue year, the T'nited States may take over all of the prop-
erty upon pay.ng the fair value, together with the cost to
the grantee of the locks or other aids to navigation and all
~ther capital expenditures. The fair values shall be deter-
mined by an agreement between the Secretary of War and
the owners, or by legal proceedings instituted by the United
States, but no claim for the franchise, good will or pending
contracts shall be made.
Provision is made to regulate the charges for service to
the customers which shall be just and reasonable, and dis-
criminatory charge is specifically prohibited and declared to
be illegal. The Secretary of War is empowered to prescribe
what shall be the just and reasonable rates in certain states,
and in case of violation, certain provisions relative to for-
feiture are applied. The valuation for rate-making purposes
is to be based on all capital and expenditures required. The
jurisdiction of the Secretary of War is provided only for
states not provided with adequate laws for the regulation of
rates, etc.
Another provision is that no works constructed under the
provision of this act may form a part of or in any manner
affect a combination or an unlawful trust, but it shall he
lawful for different grantees to exchange and interchange
current, to assist one another whenever necessary under reg-
ulations prescribed by the Secretary of War. but in no case
to raise the price or operate in restraint of trade.
This act shall not apply to irrigation or power dams or
other projects under the jurisdiction of the Secretary of the
Interior or the Secretary of Agriculture upon public lands
of the United States.
Jauua i \ 1 '.'. 1U15
P 0 W E i;
The Ferris bill vests in the Secretary of the Interior
authority to lease to citizens of the United States, or those
who have declared their intention to become such, for a
period not longer than 50 years, the right to construct and
u>aintain dams, etc., for the generation and distribution of
hydro-electric power when the project will not injure a
forest or national reservation. It gives preference to devel-
opments by states, counties, etc., for municipal uses and
purposes, and also specifies that the lessee shall at no time,
without the consent of the Secretary of the Interior, contract
for the delivery to any one customer of electric energy in
excess of 50 percentum of the total output. The physical
combination of plants may be permitted in the discretion of
the Secretary, but combinations to limit the output of elec-
trical energy, to restrain trade or increase prices are forbid-
den, and, except upon written consent of the Secretary of the
Interior, no sale or delivery of power shall be made to a
distributing company, except in case of emergency, and then
only for a period not exceeding 30 days.
'Upon not less than three years' notice prior to the ex-
piration of the lease, the United States may take over the
properties upon condition that it shall pay the actual cost
of the various items and the reasonable value of all property
la ken over, the value to be determined by mutual agreement
between the Secretary of the Interior and the lessee. Such value
shall not include the franchise, good will or other intangible
elements. In the event the United States does not take over
the properties a new lease may be granted.
For the occupancy of public lands, the Secretary of the
Interior is authorized to collect charges or rentals, the pro-
cuds to be paid into the reclamation fund under the Recla-
mation act, and upon the return to the reclamation fund of
such moneys, 50 percentum shall be paid by the Secretary of
the Treasury to the state within the boundaries of which the
hydro-electric power is generated, said moneys to be used
by the state for the support of public schools or for public im-
provements. Leases by municipal corporations solely for
municipal use shall be issued without rental charges, and
leases for development not in excess of 25 hp. may be issued
to individuals or associations for domestic, mining or irriga-
tion use without charge.
In stat.-s not provided with a commission to regulate
rates, the Secretary of the Interior shall be vested "with
power to regulate such rates until such a time as the state
shall provide a commission.
Where the Secretary of the Interior determines that land
values will not be materially injured, power projects will be
permitted, where rights now granted for the use of public
lands for the purpose of irrigation or mining alone are not
abridged.
The Secretary of the Interior is authorized to examine the
books and accounts of lessees and require reports upon oath,
and making false statements is subject to punishment as for
perjury.
The final provision is made for the transfer of permits un-
der the provision of any previous law to the present one.
lEoaler asac
In a lest made recently at the Scott Street steam station
of the Toronto Electric Light Co., Ltd., Toronto. Canada, a
554-hp. Babcock & Wilcox boiler equipped with a Riley stoker
was brought up to 354 per cent, of its rating in seven min-
utes. This performance was made possible by the moving
grates of this type of underfeed stoker. The fire at once be-
comes active, because when starting up the stoker the mov-
ing grates also start, breaking up the fuel bed so that the
air enters quickly for active combustion.
Before starting this test the boiler pressure was just be-
low the normal pressure of 150 lb., and sufficient coal was
being fed to maintain this condition. The signal to start the
stoker fan was given when the steam pressure had dropped 3
lb. below normal, and this was taken as the time of starting
the test. The load on the boilers was figured from switch-
board kilowatt reading, figuring back through tin' turbine
water rate, corrected for radiation losses. The turbine water
rate was checked by a hot-water meter in the feed line. The
turbine was called in at 9:36 a.m.; reported ready for load
3% minutes later. It was synchronized 41% minutes past 9,
but the stoker fan had started at 9:39. At 9:44 the load was
900 kw., equivalent to 95 per cent, of the boiler rating. Then
the load went to 1700 kw., which was equivalent to 201 per
cent, of the boiler rating, and at 9.46, seven minutes after
the stoker and fan started, the load was 3000 kw., or 351 per
cent, of the boiler rating.
This plant is used as a standby for the hydroelectric power
generated at Niagara Falls. It is maintained with live banked
Hies in readim to pick up the load in case of interruption
to the hydro-electric power supply. This steam station con-
tains four 554-hp. water-tube boilers, each equipped with a
six-retort Riley self-dumping underfeed stoker. Forced draft
for the stokers is supplied by a blower directly connected to
a 125-hp. direct-current motor.
V
at
Following the lire in the three manholes and 150 ft. of
feeder ducts, which temporarily paralyzed electric service in
Cleveland's business district, as reported in the Dec. 29 issue,
the Cleveland Electric Illuminating Co. took vigorous meas-
ures to restore service. Tin- photograph shows the temporary
rubles with cross-arm spacers laid on the ground over Vine-
gar Hill. The cross-arms were later raised 30 in. above the
1 'Mi--, i- ran cables follow the line of the burned
out ducts, which wen immediately below, and were spliced
onto the undamaged ends of the power-house feeders, it
Temporary Feeders
i" ins necessary to tear oui a part of the duct line to get at
these as the nearest manhole was badly damaged.
In addition to these a temporary overhead line of 10 cables
was strung from the terminal pole, over Ontario St., and
down to a manhole where connection was made with undam-
a g< 'I underground feeders.
The trouble occurred at 2 a. in., Wednesday (Dec. 16), and
partial service was restored to some sections by noon, but it
was not until Friday night that full service was restored.
The "Made in the U. S. A." Industrial Exposition, to be
held in the Grand Central Palace, New York, from Mar. 6 to
13, will be national in its scope and will embrace an extensive
and comprehensive exhibition of important American manu-
factures in all lines of trade and industry. Its dates have
been selected to show distinctly American products in New
n
P OWE K
Vol. 41, No. 2
York at a time when the city is the Mecca of buyers from all
.sections of the country in many different lines of trade, and
special efforts are being made by leading export and other
associations to bring South American and other foreign buyers
to the city at this time.
This exposition is the outgrowth of the work of the com-
mittee organized by Joseph Hartigan, commissioner of weights
and measures of the City of New York, and the organization
of the exposition, which means so much to American trade, is
in the hands of Harry A. Cochrane, one of the most successful
organizers and managers of American trade shows and indus-
trial expositions. The exposition is designed to answer a
twofold purpose — to stimulate and increase the sales of
American-made goods to our own and foreign buyers and also
to educate the American public to the resources and produc-
tions of our manufacturers and show them the goods
they can obtain in this country that they have heretofore pur-
chased from abroad.
Higph-Teimsaoini Feeders Catmse
Ssmlbw^.;^ AccHcr5eiat
The most disastrous accident in the history of the New
York subway system occurred during the rush hour Wednes-
day morning, when twenty 11,000-volt feeders let go in two
manholes adjacent to the tracks at Fifty-third Street.
Practically the entire system was tied up and several
thousand people held in the trains. The smoke and fumes
from the burning insulation pervaded the subway for con-
siderable distance, resulting in the death of one person and
rendering over two hundred people unconscious. Quick re-
sponse was made by the hospitals and the fire department and
all the available pulmotors were put into service. The fire-
men ripped off the sheet-iron pans and gratings, normally
used for ventilation, and rescued many through these open-
ings to the street.
A thorough investigation is under way by both the com-
pany and the Public Service Commission as to the initial
cause of the disaster, and the report will be awaited with
interest; for this is the second time within a month that
feeders have failed with disastrous consequences, the other
being in Cleveland as reported in our Dec. 29 issue.
PERSOMALS
WALLACE W. MANNING
Wallace W. Manning, chief inspector for the New Tork
branch of the Hartford Steam Boiler Inspection & Insurance
Co., died of pneumonia, Sunday, Dec. 27, 1914, after an illness
of about a week, at his home, 66 87th St., Brooklyn, N. Y.,
aged 34 years. He was born in Cincinnati, and had lived in
Brooklyn for about 20 years, 16 of which were spent with the
Hartford company. He was chief inspector for six years.
Mr. Manning was the son of Mr. and Mrs. John Howard
Manning, who survive him, as does his widow, Margaret Man-
ning, two children, Howard and Ward, and a sister.
Funeral services were held at S o'clock Wednesday night
at his late residence, and the interment took place Dec. 31.
WILLIAM N. SMITH
William N. Smith died at his home, 3S0 Fifth St., Brooklyn.
N. Y., on Jan. 3. Mr. Smith was born in Scotland 63 years ago
and had made his home in Brooklyn for 43 years. He was
the engineer at the Brooklyn Bridge power house for nearly
40 years, and was transferred only when that station was aban-
doned. He was well known in engineering association circles
and had a host of friends. He "was a past-vice-president of
Brooklyn Association No. 8, N. A. S. E., past-president of tin-
Modern Science Club, chairman of the Combined Associations
of Engineers of Brooklyn for five years, a member of Mel-
ville Council No. 9, Universal Craftsmen, and the International
Union of Steam and Operating Engineers. Mr. Smith was
also past-master of Lexington Lodge No. 319, F. and A. M.. and
a member of the Masonic Veterans' Association, and Bridge
Council No. 49, New York Civil Service Association. He leaves
a widow, two sons and seven daughters. The funeral services
were held at his late residence on Tuesday evening, Jan. 5.
and were attended by delegations from the several organiza-
tions above mentioned. Interment was at Greenwood Ceme-
tery on Wednesday at 2 p.m.
Heinrich J. Freyn has resigned as third vice-president of
H. Koppers Co., Chicago, effective December 1, 1914.
Paul H. Brangs has been elected a director of the Heine
Safety Boiler Co. to fill the vacancy caused by the death of
Colonel E. D. Meier. Mr. Brangs is manager of the New York
office.
Prof. John J. Flather, head of the department of mechan-
ical engineering of the College of Engineering of the Uni-
\ersity of Minnesota, is spending a year's leave of absence
in Scotland.
Prof. W. H. Kavanaugh, head of the experimental depart-
ment of the College of Engineering of the University of
Minnesota, has been elected chairman of the Minnesota sec-
tion of the American Society of Mechanical Engineers.
Arthur G. McKee announces that Robert E. Baker and
Donald D. Herr, his business associates during a number of
years past, have joined with him in the incorporation of his
engineering and contracting business under the name of
Arthur G. McKee & Co.
Maxwell Carson Maxwell, for the past seven years head
of the Department of Applied Mechanics, Pratt Institute,
Brooklyn, New York City, is now superintendent of power
and plant of the Yale & Towne Manufacturing Co., Stamford,
Conn. He is responsible for the power generation and dis-
tribution, building maintenance, new building construction,
general repairs and maintenance of machinery, shafting, etc.,
and also has charge of the tool department.
Washington University's Lectures on Public Utilities
The appointment of James E. Allison, some time chief en-
gineer of the St. Louis Public Service Commission, as lecturer
in economics in Washington University, is of particular in-
terest to the students of engineering in the University. Dur-
ing the second semester of the current year, Mr. Allison will
deliver a course of lectures, under the general direction of
the department of economics, which will deal with the eco-
nomic principles underlying the regulation of public utilities.
Some of the specific problems to be studied are the organiza-
tion and operation of public utility corporations, their securi-
ties and the methods of financing them, and especially the
method of valuing public utility properties for taxation and
rate regulation. Seniors in the School of Engineering will
now be required to take this new course which will replace
in part the second semester's work in general economics. It
is believed that this course presents an unusual opportunity,
both because of the importance of the subject and the high
standing of the lecturer.
In order to further encourage the study of economics by
students of engineering of Washington University, Mr. Alli-
son has established a fund, to be known as "The Allison Fund."
the annual income of which is to be used either for awarding
cash prizes or in such manner as in the opinion of the dean
of the School of Engineering and the head of the department
of economics will best promote the object of the fund. When
a prize is offered, competition will be open to the students of
engineering who undertake a special investigation of the Held
of public utilities under the direction of the department of
economics, with such restrictions as to eligibility as may be
specified from time to time.
PRACTICAL LESSONS IN ELECTRICITY. Bv Robert A.
Millikan, Francis B. Crocker and John Mills. American
Technical Society, Chicago, 111. Cloth; 31S pages, 5i..\S'.
in.; 323 illustrations.
ELECTRICAL MEASUREMENTS. By O. J. Bushnell and A.
G. Turnbull. American Technical Societv, Chicago, 111
Cloth; 165 pages, 5y2x8% in.; 139 illustrations.
MATERIALS OF MACHINES. Bv Albert W. Smith. John
Wiley & Sons. Inc., New York. Second edition. Cloth;
215 pages, 4%x7% in.; 36 illustrations.
MECHANISM OF STEAM ENGINES. Bv Walter H. James and
Myron W. Dole. John Wiley ft Sons. Inc., New York.
165 pages, 534x914 in.; 183 Illustrations.
POWER
Vol. fl
Ni:\\ r()RK, JANUARY 19, 1915
©
Y(
'SUP lL(Btt(BT
Written by the supervising engineer of a public utility-company
in the Middle West to engineers of different
power plants under his direction.
I lear Sir — With the beginning of the new year i. might
be h ell for all of us to investigate ever poini aboul oui
power plant with a view to getting higher ec my, if
possible, in our future operation and maintenance. Below
arc a few questions we should ask ourselves, ans«
them in our ov.n minds, nol allowing the matter to drop
until we are satisfied everything possibli ha* I
and a reporl made oui stating why certain results cannot
be attained :
Arc our boilers clean; is the brickwork in good c li-
tion, and are all cracks and unnecessary openings airtight?
Is the feed-water heater clean and working efficiently,
and is the water as hoi as possible?
In water-tube boilers, do we know that the baffling
i- tight and that the gases are not short-circuited direct-
ly to the stack?
Arc we sure all blowoff valves are tighl and thai we are
lint blowing diiw n t nuch ?
Are our dampers working, and do we use thou instead
of closing the fronl doors on hand-fired boilers, allowing
'•nlil air to filter tl igh the brickwork, etc., or, on
stokers, allowing the (ires to burn off the back of the
grate?
Are we carrying a steady maximum strain pressure?
Are all our grates, gages, due cleaners and other boiler
auxiliaries in perfect condition ?
Have the sool and ashes been cleaned out of the
of the stacks?
Do we know that the breeching i- not partially stopped
up with sool ?
Do we know that our draft is the maximum possible
under the existing condit ions ?
Are we using the minimum amount of labor to prop-
erly perforin the work in both the engine room and the
boiler room ?
Are our engines operating as economically as. possible
under their present conditions ?
Do the pistons leak?
Do the valves leak, and arc they properly set?
Ts there undue drop of pressure between the boilers
and the engines ?
1> the -ii am reasonably dry?
Is the back-pre on the exhaust a minimum?
If wc arc 11 in; up icati do we know thai we have
the maximum supei heat ?
If nut. are the -uperheaters stopped up or dirty?
Are all steam traps in lition, or are valve seats
cut, floats collapsed or other parts defective ':
ill exposed heating surfaces properly covered?
Do we know thai all valves on steam lines and all drain
valves arc tiglll ?
Are all drains from oil separators, heaters, piping, etc.,
clear?
In plants running condensing, are n'e using the proper
auxiliaries to keep our feed-water temperature a maxi-
mum and our motor-driven auxiliaries operating at maxi-
mum efficiency due to low temperature of the condensing
water?
Are we trying to get a maximum hotwell temperatun
li\ controlling the aniounl of condensing water to the
ers ?
Have we the maximum vacuum possible with the
presenl temperatures, barometer and load?
Do we keep a maximum load factor on the apparatus
in use?
I i.i ... . keep down il -i of supplies, such as
lamps, oil and waste?
l>i> we knew thai our apparatus and our station lighl
and power wi ring arc iii ~a fe condit ion ?
Have we fire extinguishers on hand, and any fire hosi
we may have properly connected ?
Have we taken all precautions to prcvcnl accidents In
protecting all openings by railings, inspecting all ladders
to ee that they are safe, looking after all weights or
otheT I that may be suspended from above, and
j to it that all pulley bloi i s, tai kle chains and
oilier tools are in perfect order; thai there arc no oily
or slippery places in or around buildings; thai piping
hi any pari of apparatus in use i- noi showing signs ol
oper guards arc placed around wiring,
switchboards and high-tension apparatus, aud that danger
signs are pla< ed v ' -sarv ?
Have we prepared for extreme weather conditions in
the way of ice, Hoods, lightning, etc.?
Havi i care of the effects o ds and
rains oi our sta -. « indows, roofs, etc. ?
The whole thought of tin- letter is to bring out any
■ a can [nit forwa rd to inprove our
economy and service. If you will put in writing anything
of this nature we will be glad to make every effort to get
the matter attended to.
[Written by F. W. Lao /".J
r o w e i;
Vol. 11, No. 3
\uunmpamig
SYNOPSIS— This sewage-pumping plant has
three JiOO-hp., 27,500,000-gal. pumping engines
mid three 260-hp. water-tube boilers. Sewage is
pumped against a head of i .' ft. through '/--<»•
discharge pipes. Drainage water is used in the con-
densers of the pumping engines and is handled
by engine-driven centrifugal pumps. Sewage from
the Back River disposal plant is utilized to operate
two 150-hp. waterwheels, each driving a 110-kw.
alternating-current generator the electrical output
of which is used for Hah linn '""' motor circuits at
the disposal plant.
What is regarded by engineers as the most scientific
system in the world for handling sewage is the twenty-
one-million-dollar sewage system now under construction
at Baltimore, Md. Prior to the great fire in 1904, the
city, with a population of nearly 600,000, was without
a sewage system, depending on cesspools and private
sewers.
Owing to the contamination by sewage of the waters
of the Chesapeake Bay and the injury don.' the oyster
industry, the legislature passed laws requiring a sew-
erage system and the purification of the sewage before
discharging into the bay. A sewerage commission was
appointed, with Calvin W. Hendrick as chief engineer,
under whose direction this system was constructed and is
now nearing completion.
By a series of intercepting sewers, about two-thirds of
the city's sewage is carried to Back River by gravity;
the rest is intercepted along the river and harbor front.
i jinn reaching the new pumping station near the center
of the city, it is pumped againsi a head of 72 ft. through
I'.'-in. iron mains for about a mile, from which point it
flows by gravity to the disposal plant at Back River, some
sis miles east of the city.
Pi m i'im; Plant
The pumping station (Fig. 1) is constructed of brick
and stone on a concrete foundation. Below the main
ll ■ the walls are of granite, and above the] are of light-
brown brick with terra cotta moldings. The roof is of
slate, supported by steel trusses carried bv steel columns
buill into the walls.
The building is fireproof, has an outside dimension of
L88 Et. by 156 Et. 7 in., and is 59 ft. high from the
ground to the top of the walls. The engine room is 180
ft. long, -V! ft. wide ami 68 ft. high from the basemen!
floor to the tie beams of the trusses. It is lined with
enameled brick for 23 ft. above the basement floor.
At present there are three triple-expansion, crank and
flywheel, condensing pumping engines (Fig. 2) having
22, A2 and 62 by 60-in. steam cylinders. These units
run at 20 r.p.m., each having at this speed a capacity
i i 27,500,000 gal. of sewage every 2 1 lir.. or a total of
82,500,000. The horsepower of the engine is 400 at
normal speed, with 175 lb. steam pressure, and operating
witb a 28-in. vacuum. The lirst receiver pressure is 32 lb.
and the second receiver has a pressure of 2 lb. gage.
These pumping engines rest on concrete foundations sep-
arated from the building so as to absorb any vibration.
The boiler room is separated from the engine room by
a screen chamber below the main floor level and a
machine simp and storeroom on the main floor level. The
boiler room is 94 ft. long by 50 ft. wide, with space for
five 260-hp. water-tube boilers set separately; at present
there are hut three 260-hp. boilers (Fig. 3). Each has
two steam drums 23 Et. 3% in. long and 36 in. diameter,
made of ,7i;-in. plate. The tubes are is ft. long ami 1
in. diameter. The heating surface of the drums i> 193
sq.ft. and that id' the tubes 2473, a total of 2666 sq.ft.
Two of these boilers are estimated as having sufficient
capacity to supply steam for the three pumps. One boiler
only is under pressure now, and it supplies steam for the
pump that handles the sewage at the present time. The
spare boiler is held to take care of fluctuations in the
sewage. Each boiler is capable of supplying steam for
one pumping engine and all auxiliary machinery.
The boilers are hand fired and have a .urate area to
heating surface of 1 to 44.4. The furnace gases pass to
an economizer above the boilers having 1550 sq.ft. of
heating surface; it heats the water from the main pump
feed-water heater from about 90 to 160 deg.
All the boilers are connected to a single brick chimney
200 ft. high above the boiler-room floor; it has an inside
diameter of 10 ft. at the top. It is lined with firebrick
for half its height and rests on a concrete foundation.
The draft is controlled by a damper regulator which oper-
ates a main damper between the boiler and the stack.
Each boiler has a connection to a CO_. recorder. One
boiler is equipped with a superheater.
The boiler feed water is metered, each boiler having
a separate meter and a differential draft gage. Feed
water is handled by either of two G and 3^ by 6-in. pot-
valve outside packed duplex pumps back of the boilers.
Coal is delivered to the plant in barges and unloaded by
a grab bucket into a hopper which delivers the coal to
a bucket conveyor, and then into any one of the five
200-ton bins above the boilers. The conveyor also carries
the ashes from the basement to an ash bunker at the top
of the boiler room, where they are loaded into wagons
for removal. Fig. 4 shows the bucket conveyor in the
basement.
At one end of the pump room are two 40-hp. centrif-
ugal pumps driven by ~< and 1 I by 8-in. compound con-
densing engines. Each pump has a capacity of 3000
gal. per min. and draws water from underdrains below
the interceptors, and discharges either through the
condensers of the main pumping engines or to the harbor
direct. These engines (Fig. •"> ) each drive an air pump
b\ a noiseless chain drive. At the same end of the build-
ing there is a 35-kw. 7 and 13 by 8-in. compound engine-
driven generator set delivering current at 250 volts, at
300 r.p.m., for station lighting and motor circuits. There
is also a smaller generator driven by an 8x7-in. vertical
engine, and a small motor-driven air compressor, used
to supply aii- for operating the exhaust valves on the low-
pressure cylinder, at from 28 to "><» Hi. pressure.
Screen Chambeb
In the basement, between the pump and boiler rooms.
is the screen chamber, and below its main floor is a
January 19, 1915
po w e l;
; ;
reservoir into which bhe sewage is discharged from the in-
terceptors and then drawn by the pumps. All sewage is
bi reened twice, first through a set of movable screens at
the entrance to the screen chamber ami then through a
fixed screen over the suction pines of the pumps. The
U>ove the screen chamber, level with the pump-room
floor, are toilets for the engineer and firemen, a niar-hine.
shop ' i 'h t.i i|i) ordinan repairs, and a store-
Above these i> a header room (Pig. 6). The
steam pipin ie1 eer the boilers and pumping engines
Fig. 1. Exterior of the Baltimore sewage-pumping station. Fig. %. Pump room, containing threi 27, -gal ca-
pacity pumping engines. Fig. 3. Three 260-hp. water-tube boilers. Pig. 1. Coal and ash bucket conveyor. Fin 5 Eivine-
oriven centrifugal circulating pumps. Fig. 6. Header room between boiler and pump roo
movable screens catch flic coarser materials, which arc is so arranged that no single accident can nut more than
, hoisted out. the water with which they are saturated is one boiler or pumping unit out of service. On the boiler-
\ removed in a steam press, and the screenings are then room side of the header room is an 8-in. main headei
burned in a special furnace in the boiler-room basement, which reduces to I in. at the ends. This header is held
78
PO \\ e i;
Vol. 11. No.
in place by brackets secured to the side wall aboul 12 ft.
above the floor. On the opposite side of the mom. near
the floor, a duplicate 8-in. header i> piped to the * > ( ► | ►< >—
>iii' header by three 5-in. long-radius benl pipes. The
pipe connections between the sei I header and the
pumping engines are 5 in. in diameter. A duplicate
sei dl' auxiliary pipes runs from the headers to tin- aux-
iliary units in the pump-room basement". Both headers
are dripped to a separate drip line ami the water of
condensation returned to the boilers. The jilani is oper-
ated by F. II. Cronin, chief engineer.
Sewage from the pumping plan! is discharged into the
main sower at a poinl where it will flow by gravity to
All spray falls on the boils ami trickles down through
8y% ft. of broken stone, coating the stone with a gelatin-
like film in which certain bacteria multiply by millions
and attack ami kill the injurious bacteria in the sewage.
When the sewage reaches the bottom of the filtering beds
il is practically pure. It then finds n- way to a central
passage under the beds ami is delivered to the settling
chambers, requiring three hours for its passage. The
sewage then drops is ft. through either of the two 150-
hp. waterwl Is in the power house.
The [lower thus obtained is used to operate two 1 10-kw.,
(50-cycle, three-phase, 2300-voll alternating-current gen-
erators (Fig. .), at •.'in r.p.m. The two 7%-kw., 125-
Fig.
Generating
IT
\\ 1 AT 111 1
I>l
w. Plant
I he disposal plant at Back River. Here there are three
hydrolytic tanks, three sludge-digesting tanks and is
acres of broken-stone sprinkler filters, together with two
settling basins. There are in process of construction 28
Iinhoir tank units, 16 sludge-digesting tank units, with
\oh exciters are each driven by a noiseless chain bell at
1000 r.p.m. : the speed of the generators is regulated by
two belt-operated hydraulic governor's. The output of
these two generators is utilized for illuminating the dis-
posal plant and lor operating small motors. To insure
accompanying sludge beds, and 12 additional acres of against interruption of service, an 85-hp. gas engine is
broken-stone sprinkling filters.
As the sprinklers are 1"' ft. below the hydrolytic tanks.
a head is obtained sufficienl to spray the sewage over the
stone beds through nozzles spaced 1 5 ft. apart. The
hydraulic head is controlled by butterfly valves which
cause the sprays to rise and fall, varying from close to
the nozzles out to the limit of 15 ft., thus utilizing uni-
formly all of the surface id' the stone bed a- the nozzles
ihrou a square spray.
coupled by a clutch to one of the generators so that if
there is uo1 enough water to operate the unit the engine
can supply the power. It runs at 276 r.p.m. and has
three m1 2xl6-in. cylinders.
At one side of the room is a motor-driven centrifugal
pump with a capacity of rait) gal. per min. against a head
of 151 ft., al 1750 r.p.m. This pump forces water into
a tank and is used for washing out the hydrolytic tanks
ami for genera] flushing purposes.
PRINCIPAL EQUIPMENT OF THE BALTIMORE, MM. SEWAGE PUMPING WD DISPOSAL LIGHTING PLANTS
No. Equipment
3 Pumpini i
Kind
Size
Triple expansion 22x42 :6 ! 50
Water tube 260 b i
Pumping sewage
Operating < Conditions
211 r.p.m . 27,500,000 gal capacity, 72 ft
head
L65 11' steam
W atei raised bo 160 deg
; Co
3 Boilers Water tube 60 Steam genoratoi-
i Economizer Green.. 1550 q El hi irfaa Heating feed water
3 Gages. . 1 >iat't - . Furnace draft
1 Regulator. Dampei Draft control Automatic
lei Uehling COa Determining per cent. COs .
2 Pump-, Duplex 6x3}x6in Boiler feeders. . 165 lb. steam....
1 Superheater Foster. Superheating Bteam
2 Pumps.. Centrifugal . 12in Drainage Engine driven. .
2 Engines.. Vertical compound 7x14x8 in Driving drainage pumps Steam ir>"> lb
■ Pumps Edwards air ... On condensers Chain bell driven
i ane. Compound 7x13x8 in . Driving 3.">-k\v. g.nrrator 1651b steam, 300 1
i Generatoi Direct curren 35 Ira ... Engine driven 300 r.p.m., 250 volt
,,' singlr s\7in. Driving small gencratoi 165 lb. steam, 100 r.p.m l' Engine Co
1 Generator.. Direct current 15 kw. .. Engine driven. . . 100 r.p.m., 250 volt Fort w ■ ] lee Works
1 Motor Direct current. 2 lip ... Driving compressor. 1350 r.p.m., 220 volts Vllis-t I i rs Co.
1 Compressor.. Christensen . , .. Compressing air. Motor driven Christensen Engineering O
2 Turbines.. Water. 150 hp . Drivin- ■i-.i..r- IS ft. head, 276 r.p.m. S. Morgan Smith Co
2 ( lenerators Alt. current . IK) kw. Power and lighting circuits 276 r p m , 3 phase. 60 cycle, 2300 volts Fort \\ ayne Elec Wor!
li ic.rs Direct current 7\ kw Exciters. 1000 r.p.m., chain drive, 125 volts Fort Wayne Elec Works
1 Engine. .. Vertical, gas So hp Driving a. c. generators 276r.j m. ...... National Meter I
Epping Carpenter ( '"
Power Specialty Co.
I.awrenee Machini I
I.nwrei Maehni. i
Whe lei < li nseri Mfg Co
1 rentoi El ine I !o
Fort Wave. El C Work-
January L9, 1915
PO w i: i;
Tlh© HIoti-lMfo Oil Ermgiini<
Bl I'.I'W L\ LiUNDGREN
SYNOPSIS— Description of the important details
and points which the designer has to considt r, with
data gained from practical < cpt n'( m i ,
The oil engine with hot-bulb ignition is a type thai has
been developed widely during the past ten years, and
which has gained a large field of application in Europe,
particularly for marine and for agricultural purposes. Of
rem isc. the main condition for commercial success is ra-
tional management and good shop methods, but the de-
sign of the product is just as important. The paramount
requirement is a reliable engine, as nearly foolproof as
lieated vaporizer or hot-bulb bead. At about dead-center
spontaneous ignition takes place, an explosion and com-
bustion follow, and the piston is driven forward on its
working stroke until it uncovers ports d and then c, where-
upon the cycle is repeated.
The typical indicator diagram of Fig. 2 illustrates
the process within the cylinder, showing the compression
to be fairly high, varying in different designs from 90 to
110 lb. per sq.in. The explosion pressure may reach 300
to 350 lb. per sq.in.
Considering the relative merits of three-port and two-
port engines, it m.i\ seem at first that the three-porl is
Fig. 1. Typical Two-Stroke-Cyclb Hot-Bulb Engine
possible, and of simple construction. The two-stroke-
cycle type appears to have proved simpler and more eco-
nomical than the four-stroke-cycle engine with hot-bulb
ignition: therefore, this type will be selected for dis-
cussion.
Reference to Fig. 1 will make clear the principle of tbi-
engine. Air is sucked into the crank chamber by the
Fig. 2. Indii itoh Diagram from
Two-Steoke-Cycle Hot-Bulb
Engine
the simpler and better, but the reverse is tine, as the two-
port engine require- a simpler casting. Also, for lubri-
cating, il i- better to avoid the third port, and the two-
rjbrt engine gives a little more power. For smaller sizes
it is advisable to cast the cylinder and frame in one piece,
ami the saving in machinery will offset the higher cost
of casting. One of the most important parts is the cyl-
Fig. 3
Km. 1 Fm. •">
Different Arrangements of Hot-Bulb Igi
Fig. 6
piston, either through ports a in the cylinder wall or
through a simple air valve b : it is then compressed in the
crank chamber and led through a bypass and ports c
into the cylinder, where it i- deflected by the piston and
expels tin' exhaust gases through the ports <l The cylin-
der is now tilled with air; not pure air, of course, as the
quantity admitted i- not large enough to scavenge per-
fectly and as the nature of the process makes per-
fect cleaning of the cylinder impossible. This mix-
ture of pure air and burnt gases is compressed by the
piston on its return stroke, and at 50 to 85 per cent, of
its travel, the fuel — kerosene, fuel oil or crude oil — is
injected through a tine spray nozzle directly into the
inder bead and vaporizer or bulb. Figs. 3 to 6 show dif-
ferent types which have been used successfully. The
clearance volume is , . to — — of the stroke volume ac-
I .i 5 .i
cording to the compression desired. The walls of the
vaporizer, which are usually casl iron but sometimes cast
steel, have to be made fairly thin, otherwise too much time
will be required to heal it for starting.
Againsl thi wall oi tin- heated vaporizer the fuel is
sprayed in a line mist. The proper formation of this
spray, however, requin - experience. If it is too fine, pre-
ignition will occur, whereas if it is too coarse, comhustio"
will not be good, and high fuel consumption will result
80
o W E l;
11. No.
A good nozzle construction is shown in Fig. ;. Aiter
passing through one or two check valves the oil " is led
through the spiral grooves and the tine hole at the point
ol the nozzle, the size of the hole and the depth of the
grooves exercising a dei ided influence upon the formation
of the spray.
Of course, the anion of the fuel pump is also impor-
tant. Tt must have -a quick, short stroke, and as the fuel
for each revolution has to be forced through a fine hole
within a fraction of a second, the pressure must be very
high: the writer has measured i to 800 lb.
A typical construction of t'uel pump and governor is
shown in Fig. 8, the design being simple and self-explan-
atory. The steel plunger is ground in the brass body of
the pump. Sometimes a packing is not provided, al-
though it is to he preferred. Tt' used, it should not be
tightened enough to hamper the return stroke of the
plunger, which is produced by the spiral spring. The
stroke can he varied by shifting the block a. and the pump
L'n,. 8. Fuel Pump and
I rOVERNOB
can also he actuate.] by hand through the lever b, which
is necessary when starting.
The simplest governor is the "hit-and-miss" type and
for most purposes it is sufficient. In Fig. 8, tin Lever c
res its motion from a cam or an eccentric. To it is
attached a lever d, which carries a square fiber disk e,
and by means of a spring k is pressed down on block f.
Usually the disk e just slides hack and forth on the block,
but if the speed in reases, the lever with the fiber disk,
due to inertia, jumps too high when it leaves the little in-
cline shown, and thus its edge g misses the edge li of the
push-rod. In this manner the speed can lie kept within
narrow limits when changing from full load to no load,
and it can he adjusted by changing the tension of the
spring /<• or by shifting the block f.
The speed also can be controlled by a flywheel gov-
ernor, which changes the stroke of the fuel pump or keeps
the suction valve open during part of the pressure stroke.
As an alternative, an ordinary centrifugal governor
may he employed which acts in a similar manner, or
which shifts a cam that in turn gives the pump a differ-
ent stroke.
A weak point with many engines of this type is the
Hon of water into the cylinder. This i- necessary
lor heavy loads as otherwise preignitions will occur. On
tin' other hand, water should uo1 be admitted when the
engine is running idle or at light loads, lor it will mis-
fire and possibly shut down. The water retards combus-
tion and effects cooling. The effect of water injection i-
shown in the indicator diagram. Fig. 9, where purposely
a little too mn h water was admitted. Usually, the water
Fig. 9. Showing Effei i oi
Watek Injection
is admitted in a rather crude way. through a needle valve
into the bypass, from which it enters the cylinder with
the air. In this ease continuous attention has to be paid
to the needle valve to regulate the amount of water. I
the load is Fairly steady, no attention is required, but
with a varying load it is inconvenient. Therefore, in
:! designs the water is injected by a small pump
under the influence of the governor, thus giving more
water to suit the load.
With a view to eliminating the necessity for water in-
jection, the writer once built an engine having a flywheel
governor that turned the pump-actuating eccentric so
that with light loads the injection took place at the usual
time, but at heavy loads so late that no preignition could
occur. The engine worked all right, hut experience lias
shown thai even here water injection proved advantag-
eous, a- it increased the power.
Of prime importance also are the dimension- of the
ports lor the air inlet and the exhaust, which depend
largely on the size and speed of the engine: the greater
the speed, the larger the ports, although in larger en-
can be made relatively smaller. On an
average, the length of the exhaust ports i- 20 to 22 per
cent, of the stroke, and that of the inlet ports !• to 13 per
cent., while they occupy about 90 deg. on the circumfer-
ence. The exhaust ports should be uncovered so early
that the pressure in the cylinder is almost nil when the
Fig. 10 Fig. 11
Wrong and Proper Designs pom Counterweights
inlet ports open, lor only in that case can effective scav-
enging lie obtained.
The pressure of the scavenging air is not high, about
I lo 5 lb. per sq.in., but it is enough to blow the air and
■ li miii of the crank case through even possible opening,
particularly around the shaft. In small engines thi-
iiot amount to much, for the bearing is usually a
straight cylindrical bushing, and if sllffii null;, oiled, doe-
January 1!). 1915
IMIW El}
81
not let any air escape. Sometimes a steel disk is placed
on the shaft, the idea being thai the side of this disk, in
contact with the hearing, will keep tight enough e\en if
the bearing wears down a little. In other cases disks are
employed which do nol rotate but which are pressed h\
springs against the crankshaft, making a good joint, tn
-till another arrangement a cast-iron ring is sprung into
the bearing.
in order to make the pressure in the crank case as high
is possible and render the crank case efficient as an air
iimip. the clearance must be kept as small as possible. A
ong stroke is therefore not advisable. The importance of
the clearance is, however, often overrated as it does not
pay to make a counterweight such as that in Fig. 10;
Pig. 11 is a better design. The writer once tried several
engines with and without counterweights and marked dif-
ference in power was not noticeable.
In a horizontal engine the counterweight is necessary,
For otherwise too strong vibrations will occur. While a
lunterweight like that in Pig. 11 is best, it is cheaper
Fig. 12. Connecting-Bod End
to cast one in the flywheel. However, it is not to be for-
gotten that such a weight revolving at high speed will
cause additional stress on the main shaft. The main parts
of the crank mechanism offer no extraordinary features,
and are usually computed, assuming an explosion pressure
of .'!00 lb. per sq.in. Per determining bearing surfaces
a lower value can be used — about 250 lb.
The connecting-rod should be so designed that an ad-
justment of its length can easily be made, the marine
head, as shown in Fig. 12, being recommended. The
head should he as small as possible, so as not to make the
crank chamber too large. Often the dimension A, Fig.
1:.'. is too small, for it must be remembered that some-
times rather violent knocks occur which are hard on the
material. Ample clearance (•% to ' L. in.) should he pro-
vided -where rough cast-iron surfaces are concerned.
For lubricating the main bearings ring oilers arc pref-
erahlc. A system of force \'m\ is really the best, but it
is nunc expensive and requires more attention. With
[forced \'f^\ the eastings arc simpler than for ring oiling,
although the performance of this type of engine is not as
1 1 as the high-compression or Diesel type, the high
economy of the latter is offset by the many complicated
parts, which make the small sizes prohibitively expensive.
For these small sizes (2 to 50 hp.) the type described has
proved reliable and economical.
1.5 y A. IS. Cakhaht
The specifications concerning safety valves in the pro
posed boiler code, as recently revised by the committee
of the American Society of Mechanical Engineers, arc of
special importance because thej express briefly and clear
ly all of the details concerning safety valves that were
discussed and unanimously agreed upon at a conference
held in Boston a lew weeks ago, at which nearly all the
safety-valve manufacturers of this country were repre-
sented. These specifications, therefore, may be regarded
as representing the best modern practice, for they embody
the combined experience and judgment of those who have
had the best opportunities for the study of the subject :
and as nothing at that conference was adopted wit hunt
unanimous assent, the provisions must he regarded as
safely conservative and proper.
Tin' paragraphs concerning common lexer valves are
of little present importance, in view of the recommenda-
tion that all other than modern pop safety valves should
he replaced as soon as possible.
An item of special interest in paragraph 1!> is the re-
quirement that each boiler carrying a pressure over 15 1b.
and requiring a valve- larger than 3 in. must have at
least two safety valves. This docs not mean duplicates,
hut that the total requirements shall he divided into
smaller units. It insures greater safety and better opera-
tion of the valves and boiler. It is not likely that both
valves would ever he inoperative at the same time. Safety
valves arc calculated to discharge the maximum steaming
capacity of the boiler under extreme conditions, and each
time a single large valve opens it will discharge steam at
a rate much greater than generated under normal condi-
tions. This sudden discharge is wasteful, and the pres-
sure will drop more than necessary before closure. To
avoid this, safety valves arc often adjusted to blow down
only one or two pounds and operate with unreasonable
violence, causing destructive hammering in the valve
and a considerable shock to the boiler when the large out-
How of steam is suddenly checked, which in effect produces
a miniature explosion every time the valve opens.
Under ordinary conditions a small valve, operating
very gently, would afford adequate relief and it requires
much less attention than a larger one. The second and
third valves would not open unless the pressure should
continue to rise, hut would he in reserve as emergency
protection two or three times greater than required under
normal condition-.
Under paragraph 20, additional safety-valve protection
is required on low-pressure boiler-, because the rate of
tlow through the same orifice is less at the lower pressure.
In paragraph 21, an entirely new maximum evapora-
tion calculation has been adopted. .Modern condition-,
with stokers and forced draft, show fuel consumption
much greater for a given grate area than formerly, there-
fore the new formula and table proposed by the A. S.
M. E. seem much more logical.
Paragraph 2 I requires that valves shall he of the direct
spring-loaded "pop'" type. Prior to is;:., all valves, and
since then some valves, have been made that are spring
loaded, hut do not have the pop feature.
For low steam pressure such valves serve fairly well,
but their chief defect is that they open only slightly
when the steam pressure rcaibes the set limit, and do not
S2
POWER
Vol. II. No. 3
lift higher as the pressure increases except by some spe-
cial device. This consists of an addition to the disk ex-
cluded from the pressure of the steam when the valve is
closed, but when the valve opens, the steam acts upon the
additional area also ami causes the valve disk to suddenly
rise more than it would by the pressure upon the orig-
inal area only.
The table on paw 36, paragraph 21, fixes the normal
steam discharge to be expected of each commercial size
of safet) valve at the several pressures given. It is re-
quired in paragraph 22 that all valves must show lift- and
discharges at least equal to the values given in the table,
when the blowdown in boiler pressure is regulated to the
amounts specified in paragraph 30. It is further pro-
vided that the discharge rating of a safety valve, for the
purposes of calculating the number and size of valves nec-
essary tor a boiler, shall not he greater than the values
given in the table. This embodies the unanimous agree-
ment of all manufacturers at their recent conference, fol-
lowing a long discussion of this special topic
The requirement in paragraph '.' ', that safety valves
must he attached directly to the boiler without interven-
ing pipe or fitting or internal dry pipe, and upon a sep-
arate outlet independent of any other steam connec-
tion, has perhaps aroused more comment and criticism
than any other in these specifications; yet in the judgment
of those having the greatest experience and special knowl-
edge of the subject, this is probably the most important
requirement. All of the valve manufacturers were unani-
mously for this provision in its present form.
The provision in paragraph 25 that the several valves
on the boiler should be set to open at pressures at leasi '■>
lb. or 5 lb. apart seems proper. To set several valves on
the boiler to open at nearly the same pressure is a mistake,
because ordinarily the amount of steam to be discharged
is much less than any one of the valves alone could prop-
erly take care of. Two or three valves opening intermit-
tently will involve much damage to themselves and harm
to the boiler.
Paragraph 30, as to the proper amount of blowdown in
pressure for which the valves should be adjusted to close,
is the result of the experience of all of the safety-valve
manufacturers. Close regulation is harmful, generally
resulting in sharp and violent action of the valve in open-
ing ami closing, shortening its useful life and unduly
straining the boiler.
'Idle purpose of the lifting gear specified in paragraph
31 is simply to afford some mean- of insuring that the
valve disk is free and that its action is not interfered
with by deposits of boiler scale or lime in the valve
guides.
Paragraph 36 specifies that safety-valve springs shall
withstand a cold compression test without showing any
pi rmanent set. This is to avoid dangerous consequences
if the spring is screwed dow n to bold the valve closed dur-
ing a boiler test. That such practice is entirely wrong-
is recognized in paragraph Id. which specifies that a test
(damp or gage shall be used to hold the valve disk upon
its -eat during such a test.
There' is also a provision that a spring shall not be used
for any pressure more (ban HI per cent, above or below
tin1 working pressure lor which it was designed. That
valves will not operate properly and will not give normal
lift or blowdown when the springs are either too weal:
or too still' is not alw:n. rei ognized.
Paragraph 39 provides that at least one safety valve
shall be connected near the outlet of a superheater to in-
sure a circulation of steam through the superheater, to
protect it from harmful rise of temperature in case the
normal demand for steam is suspended for any reason.
Valves smaller than the ."-in. size are recommended for
this service, as they are more easily maintained and kept
tight. Paragraph 41 provides for standard flanges for
each valve size.
The following joint letter was forwarded to the Council
of the A. s. M. F... on Nov. 11. 191-1:
We, the following safety-valve manufacturers, have care-
fully examined the third edition of the preliminary report of
tli, Special Committee on the Construction of Steam Boilers,
with particular reference to the specifications applying to
pop safety valves, and are :ill agreed that these embody just
what was unanimously accepted by the valve manufacturers
who were in conference on Oct. 2, 1914. We therefore re-
spectfully urge that your body accept and approve of same
without modification, aside from such typographical errors as
may lie found therein.
l£E©wsit05r=lRaiIE Greases*
A device which will lubricate continuously and auto-
matically the guide rails of the car and counterweight of
an elevator lias recently been perfected. The apparatus
fig. E
Details or Elevatok-Rail Gbeaseb
is shown in the accompanying illustration-. It cousin
primarily of a box to hold the grease, which ha- a 1*
shaped recess so that it may straddle the web. of the rail
January 19, 1915
IM) \V I. R
83
Through an opening in this recess a double-ply leather
wiper projects. It i< notched to lit the rail and, being at-
tached to I hr wiill of the box by a flexible spring, is free
to move vertically. WTien the car is going up, the Leather
wiper is in tin' position shown by the full lines in Pig. 2.
Tlir dotted lines show its position for a downward move-
ment of the car. The spring also tends to push the
leather forward against the rail.
The box is filled with an even mixture of grease and
graphite of the proper consistency to flow to the rail
when it is agitated by the movement of the leather and
spring. The greaser is attached to the top beam of the
ear or counterweight (Fig. 1). The feed of the grease
is varied h\ moving the box toward or away from the rail.
To re ve a in excess grease from the rail and drop it
hack onto the leather a double-bladed scraper straddling
the rail is mounted on top of the box. The blades are ad-
justable i"i- varying widths of guide, and in or out ad-
justment is permissible a- they are secured l" the top of
the box by a screw passing through a slot.
When supplied, the box i- filled with grease. At the
end of six months the level of the grease is usually low-
ered i'< a poinl from which it cannot reach the rail. About
hall' a pound of grease is needed to refill the box, ami it is
claimed that the device is then ready I'm' another six
n tie' service. The cover may he removed bj loosen-
ing three si Tews whieh pass through the casing of the box
nil,; In- projecting down from the cover. With this ar-
rangemenl it is not necessary to remove the screws en-
tirely ami thus run the risk of dropping them into the
elevator n ell.
Results of tests conducted on electric elevators equipped
with these rail greasers show a reduction in starting
torque of from 10 t<> 25 per cent, over dry ami hand-lubri-
cated guides, other advantages claimed are savings in
shoe ami rail, the eliminal ton of ja rs ami jerks common to
an elevator guided by dry rails, noiseless operation ami no
dropping of oil or grease to the ll ■ of the well. The
upkeep is small as the only part subject t" wear is the
leather wiper. This lasts for a long period ami max be
renewed at a cost of a few cents. The leather is made
in sizes in conform with rails having face measurements
from y2 to 9 in. W. A. Garvens, 708 Smith Ashland
Blvd., Chicago, is supplying this ,le\ ice.
.Puccini
jmgpim©<
.r im Omlba
Bi Prank E. Small
SYNOPSIS — Impressions of an American operat-
ing engineer sent to Cuba to /ml some run-down
plants in safe and economical condition.
The writer hopes that none will construe the substance
of the following to be a slap at all engineers in care of
Cuban plants.
On going to Cuba as a trouble man one feels that the
island has grown in plants faster than it has in engineers
competent to care for them. There are man] g I men,
tn be sure, but many are unlit. This condition among
engineers is aggravated by the unfavorable attitude of the
owners or employers toward skilled labor. Cuba is of
course warm, and ice ami refrigeration plant- be
more numerous as industry grows. Some business houses
have failed owing to unnecessarily high operating costs.
Some of these plants are quite old, five to ten years, and
the equipment has greatly deteriorated or become obsolete.
To convince the owners that they should first hire a g 1
engineer at double or triple the usual local salary, and
should immediately spend mone> for new equipment when
they are already losing money, is difficult.
The writer has found plants whieh. when new. pro-
i six tons of ice for one ton of coal, although at the
time of his visits thev were getting but one to two tons
ton of coal. Some plants in ether industries are
just as bad.
At one plant a locomotive-type boiler was set in brick-
work This seemed new and led to an inquiry as to why
the brick setting was \w\. The engineer informed us
that the firebox had been patched so many times that it
was deemed advisable to set the boiler in brick, putting the
furnace under the hack of the boiler to reduce the tem-
perature in the firebox.
The first look into the furnace of a horizontal return-
tubular boiler in this plant showed water running from
around the edges of a 24x48-in. patch, the second one
tn be put on that crown-sheet. The writer threatened to
leave if permission was not given to reduce the pressure
to 80 lb. (it was 100 Hi.). This .seemed to create con-
siderable laughter in the office, but when the manager
was shown that that patch -was carrying a load of over
lie. 000 Hi. he began to congratulate himself on being
alive.
For some reasons the boilers here had their gage-cocks
removed, gage-glasses being depended upon for showing
the levels. The differences between the readings of any
two steam gages was so great that for safety's sake
it was necessary to immediately learn the correct pres-
sure.
A steam hose had been used to clear the tubes of soot,
and although the front ends were clear enough, the back
ends contained soot that had accumulated and baked on.
\ brush could not be pushed through the tubes.
On the wa\ t ie plant the first day. the engines could
be beard pounding before the writer was within a block
of the plant. Notwithstanding this condition, the engi-
neer was as contented as could be. This plant was but
four years old, although one would take it for fifteen were
it not for the modern equipment.
The w liter's experience leads him to believe that own-
er- should, for a time at least, receive i e support from
builders. Equipment is installed and operated until ac-
cepted, but in many cases it is necessary to "break in"
the purchasers' engineers, and this is by no means done
thoroughly. There are few competent men available, and
consequently it is but a short time until the equipment is
giving | r service and the builder's reputation with the
local owners is injured. The builder would do well to
try to get a good man to care for the plant.
At present plants here are not so much in need of men
win. can obtain economical results, although these must
follow, a- nl' men who can keep equipment running well.
M
p o at e r;
Vol. 41. No. 3
Belles' lElRRicaeimc^ 2&i&
In checking up boiler efficiency it is essential to analyze
the Hue gases and take temperature readings as thej
the boiler. It is also desirable to note the draft at the fire
and the drop in draft between the furnace and the damper.
a> tb determine the air supply. When these
data are known it is possible to calculate the combustion
efficiency.
A convenient and complete kit of apparatus for obtain-
ing the above mentioned data is being supplied by the
-ion Instrument Co., Detroit, Mich. The equipmenl
is neatly arranged in a case. The illustration shows
the various devices in position for testing a boiler. The
is divided int.. thro- compartments, hut by an in-
■eniuos arrangement tin covers t.. all three compartments
are locked by a small padlock within the handle of the
.ase. A differential draft gage is contained in one
compartment, the middle chamber contains an Orsat ap-
paratus of special design and the third space a high-tem-
perature thermometer, a special printed report pad for
recording the various test data, .-onie rubber tubing, etc.
tube to prevent breakage and is provided with sectional
extension pieces -" that it may he inserted through any
ordinal wall of a boiler setting. In the compartment
containing the thermometer there is -pare for storing
tubing, data pads and bottles containing the chemical
mixtures.
The kit is also provided with a book of instructions
and manual ..f testing methods, a pad of standard test-
report blanks, proper chemicals for absorbing C()2, 0
and CO, air.. el. mixed for use, a funnel, and in short,
all the necessary parts and materials required to conduct
a boiler-furnace efficiency test. That all of this equip-
ment can be kept in a small, compact case ready to be
.allied to the point of immediate use is an advantage.
:8
Soamse ©iriijfpE&gsi Hdle©.§
An operator complained of the rapidity with which
the brushes of his engine-driven generator were con-
sumed, although the load was comparatively small and
there was no evidence of sparking. All brush-contact sur-
appeared to have been recently sandpapered, but he
Kit Unslung and Readv for Use
As indicated, the draft gage is arranged so that both
the draft in the furnace and the drop in draft between
furnace and damper ma\ he conveniently taken. For
this purpose rubber tubing oflsui table length an. I sectional
iron pipes of the Bshpole variety are provided. The
draft gage is graduated in hundredths of an inch. For
compactness the three pipettes and the burette of the
ed in a circle. The analyzer i< graduated
ad in tenths ••! one per cent. The necessary rubber
tubing for the analyzer is furnished.
The high-temperature thermometer i- encased in a brass
stated that they had not been touched since their in-
stallation about ten days before. It developed that the
I been -hipped from one place and the gener-.
ator from another and that they had been connected on
the ground.
A- the commutator showed some eccentricity, a local
machinist was engaged to turn the commutator in it-
own bearings, lie had used a diamond-pointed tool.
which was all right, hut had also used a coarse (v^A and a
laratively deep mt. thereby converting the commu-
tator surface into a milling .utter, so tar a- the brushes
19,
PO"WEK
wi'iv concerned. On being recalled to finish the job, he
explained that he had made that kind of surface on pur-
pose, so as to make the brushes "hite better."
In another case, complaint was made thai a machine
would ii"1 generate, but by the time the inspector arrived
it was generating all right. The operator stated that, as
far as lie knew, he had not done anything to help mat-
ters, but had let the machine run to "work in the bear-
ings." II seems that he was particular how the machine
looked and bad been touching up bolt-heads and nuts
with gold paint, and while doing this had concluded to
give tin' commutator a coat, with the result that the ma-
chine would no! pick up until the brush friction had re-
moved the gold paint.
In another ease a plain shunt-wound generator and an
interpole generator were being operated in parallel. When
the attendant wished to withdraw the interpole machine
from parallel operation, he found it difficult to reduce its
current to a low value. He had observed the practice of
oiling commutators occasionally and at such times had
noticed the current decrease on the machine. Being in
the habit of applying the results of his observations, he
adopted the practice of oiling the commutator of the in-
terpole generator whenever lie wished to take it out of
service. The result was that the c mutator absorbed so
much oil that it eventually broke down.
JmiEagsiroircsl iU©wijjS)ji©<=ji> now ir-aasinyjp
Among the line of Kingsford centrifugal pumps is
that known as the double-flow type, Fig. 1, which in
the illustration is motor driven. It is manufactured h\
the Kingsford Foundry & Machine Works, Oswego, N. Y.
Pig. 1. Fvixgsford Double-Flcv\ Pump
A sectional view of tin' pump is shown in Fig. ".'. In
this design the water-ways are liberal, the stuffing-boxe
are of ample depth and tin' span between the oil-ring
bearings is small. As the water seals are internal, the
Leakage is collected in the bearing buckets, and from
there piped into a common waste-pipe.
The pump is so designed that with one head removed
and the setscrews in the coupling loosened, tin' shaft and
impeller may he removed from the casing without dis-
turbing the suction or the discharge pipe connections.
As the joints between the heads and shell are metal to
metal, set gaskets are eliminated and alignment is in-
sured. The impellers are made of single castings inte-
gral with the balance ring, which under ordinary con-
ditions will wear until the impeller requires renewing.
Fig. 3 shows an impeller with staggered veins; this di
sign is \\<vi\ in pumps of large capacity.
Theoretically, the double-suction pump is hydraulically
balanced and free from end-thrust, but in practice un-
equal leakage through packing fissures, inaccuracies in
casting or unequal wear, supplemented by lodgment of
Fig. 2.
Sectional View of the Kixgsford Double-
Flow Pump
foreign matter, all tend to disturb the theoretical bal-
ance, and the result is that end-thrust is present. In
this design of pump this difficulty is overcome by auto-
matic water balance, with which it is claimed neither
wear nor foreign matter will disturb the equilibrium of
the impeller. Therefore, stationary and positive thrust
bearings are eliminated.
Leakage from the pressure to the suction side of the
impeller is reduced to a minimum by bronze packing
rings. They are attached to the heads and in connec-
tion with rotating rings on the impeller form part of
the automatic water-balance device.
Although the shells or main casings are made split
horizontally, when conditions warrant, the pump is gen-
erally made with the shell of a single casting with inte-
gral sections and discharge openings. The volute sur-
rounding the impeller permits of omitting diffusion veins
for low and moderate heads. The design of this pump
makes it possible to locate suction and discharge open-
ings ut various positions, as for instance a pump with
a horizontal or vertical discharge is sometimes found
Fig. 3. Pump Shaft and Impeller
convenient, and frequently the suction and discharge
openings are desired on the same side.
The head and hearing housings, secured to the main
casting by studs, come metal to metal, and a water-tight
joint is secured by a rubber cord placed in a triangular-
shaped space formed in joining the heads and shell. The
m;
POWEE
V..1. +1. No.
head forms a part of the suction chamber ami guides the
water into the impeller opening.
Ordinarily, the pump shaft is of machinery steel, made
exceptionally large and stiff to prevent bending and to
carry the impeller without vibration. When liquids
which affect iron and steel are to be pumped, the shaft
is covered by a sleeve of composition metal. This sleeve
i^ provided with threaded ends and fits snugly on the
shaft. It is easily removed by a special kind of wrench
In other than belt-driven pumps, a flexible coupling
is used between the pumps and prime mover which allows
I'm- any slight inaccuracies in alignment. This coupling
((insists df cast-iron halves, one of which is fitted with
steel bolts extending into corresponding holes in the
other coupling half, the driving force being transmitted
through the medium of rubber cushions mounted on the
sleeves.
Hamperial Poirtalblle Ais° Cosimc
The small portable gasoline-engine-driven air com-
pressor, illustrated herewith, has been developed by the
Ingersoll-Rand Co.. 11 Broadway. New York City.
The compressor is self-contained and is operated by
a simple single-cylinder gasoline engine coupled directly
to the compressor, both pi-ton- working on the same
and a 15-gal. capacity gasoline tank is supported on a
large tool box. The outfit complete weighs KiOO lb., and
is designed for hand transportation, hut it can be fitted
with tongue and singletrees if desired.
POKTABLE AlK CoMPliKSSOI!
crankshaft. The engine is of the single-acting, two-cycle
type This standard air compressor has a capacity of
15 (ii. ft. per min. at a pressure of 90 hi., and is fitted
with an air unloader. The engine speed is controlled by
a centrifugal governor.
Cooling is provided for by a gear'driven pump and an
automobile-type radiator with large tank capacity, serv-
ing both the compressor and the engine. The radiator
i- assisted by a large fan.
An air receiver tested to 300 lb. water pressure and
fitted with a safety valve, pressure gage, the necessarj
piping, outlets, etc., is hung at one end of the frame
By J. H. McDougai
Some time ago the writer had occasion to test a large
alternator to determine its efficiency and segregate the
losses. The plant was situated in the mountains, at a
very inaccessible point; on which account, together with
the fact that the test had to lie made on short notice,
it was necessary to depart from the common methods of
testing.
The machine was a three-phase, 2300-volt, (iO-cycle.
o500-kw. alternator direct-connected to two tangential
waterwheels and operated in parallel with a number of
other plants. The waterwheels were equipped with needle-
nozzles, the needles being operated by hand and the gov-
erning done by deflecting the nozzles. One governor con-
trolled both nozzles.
In order to improve the accuracy of the test, two cur-
rent transformers were installed of such a size that the
losses of the machine, run as a motor, would give full-
scale deflection on the indicating wattmeters. The reg-
ular two-wattmeter method of measuring three-phase
power was used. Both nozzles were disconnected from
the governor. It was also deemed advisable to install
short-circuiting switches on the current transformers, as
in synchronizing practically full load was sometimes
thrown on the machine, which it was feared would burn
up the small-capacity current transformers. As no reg-
ular short-circuiting switches were available, two blades
of an old 250-volt quick-break switch were mounted on
separate boards and served very well.
In making the test one nozzle. No. 1. was completely
closed, and the other. No. '?. was gradually opened until
the machine with its field circuit open was brought up to
normal speed. After noting the position of the hand-
wheel and the number of turns, the nozzle on this wheel
was closed. Nozzle No. 1 was then opened and the ma-
chine brought up to speed and synchronized with the
system. P>\ adjusting this nozzle the load was brought
to zero. Xozzle No. 2 was now opened to the point where
ii Mood in the first pari of the test and the amount of
power furnished to the system was noted. It will he
seen that this power plus that lost in the armature by
resistance will equal the power consumed by friction
and windage. This is evident, as the water that was used
to deliver this power was equal to that used in overcom-
ing friction and windage in bringing the machine up to
speed. A very small error would be introduced due to
neglecting the load losses, bul as this would be but a
fraction of one per cent., it may be neglected.
In order to determine the core loss, nozzle No. 1 was
closed and No. 2 was used to bring the machine up to
speed, and the field current was broughl up to the nor-
mal full-load running point. The position of nozzle No.
2 was noted and if was then closed. Nozzle No. 1 was
now opened and the machine brought up to speed and
synchronized. After bringing the load to zero, nozzle
No. 2 was opened to its position at the beginning of the
core-loss test and the amount of power delivered to the
January 19, 1915
P 0 W E R
s;
system noted. This power plus the resistance loss in the
armature minus the friction and windage losses gave the
core loss.
To check this last reading, all water was taken off the
wheels and the generator allowed to run as a motor. This
reading checked very closely, although to gei satisfactory
readings, it was necessary to somewhat change the excita-
tion, which of course changed the core loss to a slight
extent.
In the matter of load losses, the recommendations con-
tained in the Standardization Rules of the American In-
stitute of Electrical Engineers were followed. One-third
of the short-circuit core hiss was. as an approximation
and in the absence of more accurate information, assumed
as the load loss.
The machine was short-circuited and brought up to
B] d by nozzle No. 2, and the field current increased
until full-load current flowed in the armature windings.
The short-circuit was then removed and nozzle Xo. 2
closed. The machine was synchronized by nozzle No. 1,
and Xo. 2 was opened to the point at which it s1 1 at
the beginning of the load-loss test, ami the amount of
power delivered to the line was noted. The core loss I'm
the excitation used on short-circuit was determined as
for the lull-load voltage. Therefore, the power shown
in the load-loss test plus the armature resistance loss,
minus the friction and core loss at the excitation used.
divided by three, gave the core loss as nearly as it could
he determined.
The armature resistance was measured with an am-
meter and a low-reading voltmeter. Thus the armature
resistance losses could be calculated. The Held resistance
,. also measured and full-load excitation noted so that
resistance losses in the field could be computed.
These completed the list of losses and the efficiency could
i i ifore he computed by dividing the output by the out-
plus losses. The mechanical hisses of the water-
heels were, of course, included in the mechanical losses
ined, hut as the guarantee included these, no effort
was made to segregate them.
Ds Memta
WL<egwl
'■he •'World's Best'' automatic feed-water regulator,
manufactured by the McDonough Automatic Regulator
Co., Dctn.il. Mich., is of the thermostatically controlled
pe. The main purpose of its design is not only to se-
cure a continuous feed, hut a positive automatic control
Of a continuous feed to vary with the boiler load and to
maintain a water level within limits best suited for con-
stant maximum boiler capacity, efficiency and uniform-
ity of operating conditions.
This regulator, Fig. 2. maintains a continuous feed
proportional to the evaporation and for light and uni-
formly varying loads a constant water level. For sud-
den increase in load and the resulting rapid drop in the
water level, the regulator valve does not open suddenly
to admit a large quantity of water into
the boiler, hut there is a time element in
the expansion of the tubes operating the
valve which uniformly increases the feed.
permitting the immediate furnace heat
to he used tor evaporating and not for
heating cold I' I water.
This regulator consists of a special
feed valve, two headers and two expan-
sion tubes connected in parallel through
a rigid linkage to the feed-valve stem.
The use of two tubes doubles the power
of expansion and contraction, and the
levers transmit the motion to the feed
valve in a ratio of ."> to 1. A turnbuckle
and pointer indicator permit of accurate
adjustment of the valve, and the pointer
indicator shows tin/ position of the valve
while the regulator is in operation.
The regulator is installed in an in-
di I position. Fig. l. wholly supported
by t!i" i'eed piping with the connections
made to the water column, as shown. In
operation, the lower ends of the tubes
are filled with water and the upper with
steam. As the water falls or rises in the
boiler, it correspondingly falls or rises in the regulator
tubes, presenting a greater or lesser area of the tube sur-
face to the steam, causing them to expand or contract
accordingly. The inclined position of the regulator gives
the greatest variation in exposed tube surface for a given
variation in water level and the greatest sensitiveness
to variations in load.
SWiwc/fr..
Fig. 2. Regu-
lator
Fig
Chart Showing Feeding Characteristic or
THE ReGULATOK
The chart. Fig. 3, taken from two boilers in regu-
lar service, each equipped with this regulator, shows the
uniform and constant feeding characteristic of the
device.
ss
pow e i:
Vol. 41, No. ::
Engimi<
By Frederick \Y. Salmon
SYNOPSIS — In the literature un the proper size
of steam and exhaust pipes for steam engines there
is little in practical shape for ready use; therefore,
data of sizes of a large number of successful plants
hare been plotted and tallies given of mines ob-
tained by plotting smooth em-re* representing fair
averages of good practice.
There arc two methods of determining pipe sizes — one
is by a long and elaborate computation of pipe friction,
with the use of coefficients based on
a limited number of experiments; the
other is what some people would call a
rale-of-thumb, in which the pipe size
is determined as a Fraction of the cyl-
inder diameter. The first of these is
commonly based on a steam velocity in
feet per minute or per second.
For the modern steam plant in a
factory or the municipal plant of a
small city, designed according to con-
ventional practice and having a fair
grade of reciprocating engines set close
to the boilers, it is much more conven-
ient to calculate pipe sizes from the
gross pounds of steam per hour re-
quired by the engine at the best rated
load and make use of a formula based
on the rnosl suitable pipe size as estab-
lished by several decades of good com-
mercial praet ice.
The old rule-of-thumb would an-
swer but for the fact that during the
past few years some <>( the engine
builders have increased the rated
speeds of their engines — and therefore
the rated horsepower and steam con-
sumption— without apparently in-
creasing the pipe sizes, and in >< •
cases wire drawing results: whereas, if
these simple formulas were used for
l lie p. ui n ds per hour and the pipe sizes
chosen accordingly, the wire drawing
would not he higher than that here-
tofore established as good practice.
The curves and constants giverj in
the chart are from the mean curves
found by plotting the results of data
obtained of sizes of engine pipes used
in a large number of successful power plants. The maxi-
mum and minimum curves were quite irregular, hut they
appeared to vary up to about 10 per cent, of the mean
values.
As illustrating the use of the table, take the case of
a I4x36-in. none lensing Corliss engine under 100-lb.
-team pressure by gage, and running 100 r.p.m.. which is
rated by the builders at about 135 i.hp. at i \ cutoff (the
rating of different builders varies Bomewhat), and assume
such an engine ,-il that 1 1 to take \'i; |h. of steam per
hour, which is about what many engine builders guarantee
in their contracts for such a size under these conditions
There is then 135 i.hp. X ~<i lb., or about 3500 lh. of
steam per hour, and looking on the chart the nearest sizes
are found to he 1 -in. steam pipe and 5-in. exhaust, which
sizes arc as small as one should like to make them for or-
dinary conditions of plant arrangement.
In special cases of very large plants or long steam
mains, the drop in pressure from pipe friction should
he calculated. Perhaps that method of choosing pipe
sizes should be followed, but the table will be found
2 3 4 5
Internal
Sizes of Pipes
16 16
Power
6 7 8 9 10 II 12 H-
Diamefer.or Bore of Steam Pipe in Inches
for Steam Engines, Based on Successful Practi
■ases arising
useful for a large percentage id' the
practice.
y.
Iguoranc) — _\ visitor who could tell about volts and am-
peres was walking through a 110,000-volt substation pointing
at high-tension oil switch leads with an umbrella that hail
a steel stick in it- The foreman pin him out before the
current got a crack at him.
%
Laborer Cooling :i Hot Box- over a fiSO-volt third-rail with
a metal pail of water that had been salted to prevent freezing:
They succeeded in bringing him to.
January 19, 1915
r 0 w e u
89
ells' sua 11 bc IPtmtnmps
l!v R. A. Lachmann
The accompanying tables provide a ready means of as-
certaining the power and rapacity of a plunger pump.
Although computed for single-acting pumps with a slip
of 5 per rent., and working against a pressure of 1000
TABLE 1— CAPACITY AND TOWER OF SMALL SINGLE-
ACTING HYDRAULIC PUMPS
O § « C £ ■ -
— Z. X — — — —
%
%
► 1
%
i'-.-
I %
%
%
r % '
%
i %
%
%
j
%
%
%
I %
r ■-=
%
%
i '=
%
2> .
%
%
%
I %
f % "
%
1 %
l %
%
3 ■
I %
i %
I %
il 12
0.19
0 27
n 2 1
0.38
ii 54
0.36
0.57
n 81
0.16
0.25
0.36
0.32
0.51
0.72
147
0.63
210
0.9
140
0.6
220
0.95
315
1.35
56
0.24
88
0.38
126
0.54
112
0.48
176
0.76
252
1.08
ies
ii 72
264
1.14
378
1.62
o-1.
0.9
♦Figures given are ", '; less than the theoretical capacity,
on account of loss due to slippage.
tFigures given are 25'*, more than the theoretical horse-
power, allowing for friction.
TABLE 2 — CAPACITY AND POWER OF LARGE SINGLE-
ACTING HYDRAULIC PUMPS, SINGLE PLUNGER—
•\-l.v Tn I-, -in. i iIa.\ii:tki:
~ 2 U
1% ....
l'4 ....
1% ....
1% ....
1% ....
i ■'-. . .
*::::
i
i% ....
i'i ...
i% ....
i •..
i% ....
i% ....
.»;;;;
m ....
i% ....
i% ....
i'. ....
i% ....
i% ....
•Figures given are '>';
on account of loss due to
tFigures given are :"
power, allowing for frictii
• -
'_ -
*o
16S
0.72
229
1.00
298
1.29
•'7-n
1.64
466
2 02
564
2.44
672
2.91
788
3.41
9 1 5
:: 96
2 in
286
1.25
873
LSI
473
2 05
583
: 53
705
840
■. ,, ;
'.i v :.
1 26
1144
1 95
2 .", "
1.08
344
1.50
447
1 94
567
2.46
7iHi
3.03
M6
3.66
100S
4.37
1182
-■ 12
1373
5.94
2.49
0.66
11-
1.50
1 85
2 23
2.65
3.11
3 62
II Ml
1.08
1.41
1 vll
less than the theoretical capacity,
slippage,
more than the theoretical horse-
lb. per sq.in., they may, by a few simple calculations, be
made to applj to any direct-acting pump. A couple of
example will make this dear.
Assume a two-plunger pump with %-in. plungers, a
•.'>.. in. stro i (the movement of the plunger in one di-
rection) ami a speed of Km r.p.ni. when working against
a pressure of 1000 lb. per sq.in. Under these conditions
the capacity and necessary horsepower can be read di-
rectly from Table I .
First, look for 2% in. under the heading "stroke;"
then the number 2 in the column headed "number of
plungers," and opposite this For the plunger diameter of
:; i in. Following this line to the right, there will be
found the desired information under the respective col-
umns; that is, the capacity in cubic inches per minute
will be 210, the capacity in gallons per minute will be
0.9, and the horsepower required to drive the pump will
be 0.66. A l-hp. motor would probably be selected.
TABLE 3— CAPACITY AND POWER OF LARGE SINGLE-
ACTING HYDRAULIC PUMPS, SINGLE PLUNGER—
1%-IN. Til 4' ..-IN. DIAMETER
£|3
r!
r. — — — -
1%
2
2U
-',
- :,
::
3%
4
4%
1%
2
2V<
2%
-\
1049
1194
1511
1865
2 !•:. 7
8.07
9.77
11.63
3656 15.83
6044
1311
1493
1889
2331
135
S21
6.46
8.18
10.09
12.21
7,969
70 19.79
100 ion inoo
4.77
5.89
7.12
S.4S
11.54
15.07
19 0s
4.14
4.71
5.96
7.36
8.90
10.6O
14.43
18.84
23.85
32.7H
17,74 6. Si
1791 7.7K
2267 9.81
2798 12.11
33S6 14.66
1029 17.47,
:.4M 23 75
7163 31.01
16 39.24
Figures given ;,re .v. less th
account of loss due to slippage
tFigures given are 2.7'., more than the theoretical horse
wer, allowing for friction,
16
17.31
22.61
2 s 112
the theoretical capacity,
Now assume the following conditions: Stroke, ''l)> in.:
diameter of plungers, % in.: number of plungers, I:
-peed. 150 r.p.ni.: pressure. 1700 lb. per sq.in. Find
the capacity and the horsepower required.
As the quantities and sizes involved are directly pro-
portional to those in the table, lirst double the quantities
given for two %-in. plungers; this gives the first multi-
plier, namely 2. Then since 150 r.p.m. is 1.5 times L00
r.p.m.. shown in the table, the second multiplier will
be 1.5. The third multiplier is 1.7, since 1700 lb. is
LI times 1000 lb. The product of these three multi-
pliers is :
2 X 1.5 X Li = 5.1
which is the common multiplier. Then the capacity is
5.1 X 210 cu.in. = 1071 cu.in. per min.
5.1 X O-'-1 gal. = 4.59 gal. per. min.
5.1 X 0.66 ftp. = ::.:
or about :Ko hp. would be required.
166 h
90
po w e i;
Vol. 41. Xo. 3
Htiaggexni& Ps'ess^is*© JRefrramm ©bMe&§|
From time to time in these columns the various Nu-
gent lubricating devices, such as the pendulum erankpin
oiler, the antipacked telescopic oiler for crossheads and
eccentrics and the illuminated oil filter with the auto-
matic water separator, have been described. For about a
year, however, the company has been combining these va-
Nugext Oiling System
rious devices into a complete pressure system for individ-
ual units, such as is shown in the accompanying illus-
tration.
A simple plunger pump actuated by the engine eccen-
tric draws the oil through the pipe D from the storage
space of the filter. The oil is forced to the system on the
engine and to the reservoir A, which is provided with a
gage glass and an overflow leading from the top of the
tank. The oil flows back to the filter through the pipe B.
By manipulating the valve II any pressure up to 25 lb. can
be maintained on the system. A check valve •/ prevents
oil returning to the filter through the Miction. Open-
sight feeds supply the oil to the various point- of ser-
vice, and drains F. F and G from the crankpit, eccentric
pan and outboard pillow block return the oil to the water
separator and oil filter shown under the floor. If any of
ipenings in the sight-feeds should become clogged, it
is an easy matter to tone up the pressure to the limit
previously given and blow out the obstacle. The safety
\ sel at 25 lb., protect- the system.
Tip..- /. and .1/ convej the oil to the outboard bearing,
A" i- a support for pipe L, K is a sight-feed in the water-
outlet pipe leading to the sewer, Q is a gage to show the
pressure on the system, and P is a drip pan for the oil
pump. The system is thus complete in itself and is actu-
ated by the unit it serves. If any trouble should develop
it is localized to the one unit. Additional information
may be obtained from W. W. Nugent & Co., Chicago, 111.
A combined feed-water trap, heater and weigher is
being marketed by the F. C. Farnsworth Co.. Bush Ter-
minal. Brooklyn. N. Y. The illustration shows a sec-
tion of this tilting type of apparatus.
The tank has two compartments which fill and empty
alternately. Instead of trunnions, flexible copper hose is
used. Water is carried to the top of each compartment
and distributed over the copper heating coil through a
perforated pipe. First, the coil is heated by exhaust
steam fed in through the vent valve. When the compart-
ment fills with water its weight tilts the tank, interchang-
ing the valve, venting the opposite side and simultan-
eously admitting -team at boiler pressure in the coil and
^-Receiving Check Valve
B-A -.:- . ' Kct Valve
fh To Boiler
f Tank Compartrrert C
ranh C:~??rtmenf D
Exhaust from tent to heating main,
anu aMiiiaru atmosphere or cold
"* " water mam
The Faenswobth Tilting Thap
out onto the surface of the water to force the latter into
the holler.
The trap may be furnished with or without the heater.
A counter ma\ lie made to register the number of oscil-
lations and the weight of water delivered calculated from
Traps acting on the same principle, but with modifica-
tion of the inlets, outlets 'and partitions, are adapted to
services such as those of a blowoff or condensate weighing
tank and trap, and of sewage or water lifts using steam
or compressed air.
January llJ, 1U15
ru vv E 1;
'.11
fsxsdsJl
'COiniStotUKDftBOBIi
B"i OSBORN MoNNETTf
SYNOPSIS— -Limited headroom and floor apace,
call for unusual designs of setting not recommend-
ed for standard practice. Smite interesting cases
are presented.
Installing new boilers in old office buildings offers one
of the most difficult problems the designer will encounter
if smokelessness is one of the prime considerations. Fig.
1 shows bow it was done in a plant requiring additional
boiler capacity with limited floor space and headroom in
which tt) install it. It was necessary to provide 100
boiler-hp. in a floor space of ] ft. 5 in. by 8 ft. 5 in. and
s headroom of 10 ft. and to find room for a smokeless
setting. The solution was a Worthington boiler of spe-
ETig. 1. Worthington Boiler, l (to II p., \\i> Moore
Stoker
rial design in which the rear mud drum extended some
18 in. below the normal position and connected with the
front mud drum by 21/2-'"- tidies, spaced I in. on cen-
ters. It gave IS in. of free space between the bottom of
(In front mud drum and the Moor line and provided op-
portunity for a tile roof on the tubes connecting the mud
drums. Strong ignition for a Moore stoker installed
directly under the boiler was thus obtained. This unit
has met every requirement of floor space and headroom
ami is running smokelesslv mi loads up to 10 per cent,
above rating. The same combination in almost any ca-
pacity can be supplied by simply adding to the width of
the setting without increasing the headroom or floor space
in a lengthwise direction.
Fig. 2 is another application of the Worthington boiler
to limited floor space. The floor space occupied by the
boiler is 10 ft. 2 in. wide by 1 1 ft. long, while the stoker
m\<]± '■'< ft. ■'! in. to the length. The headroom to the steam
•Copyright, 1915, by Osborn Momiett.
tSmoke inspector, City of Chicago.
nozzle of lb.' boiler is 16 \'\. This unit is of 300 boiler-
hp. capacity. The ignition arch is (1 ft. long, with a low-
pressure water-back furnishing a permanent support for
the built-up bridge-wall. Between the two. good throat
action is obtained, insuring complete combustion and
good economy. The arch is supported by another low -
Pig. 2. A 300-Hp. Worthington Boiler and Chain
Grate on Limited Floor Space
Fig. 3. A 390-Hp. I'.. & W. Boileb and Laclede-
Christy Chain Grate; ;Ft. Headroom and 7-Ft.
Extension
pressure water-hack and provision is made for ventila-
tion over the arch to insure satisfactory life.
The horizontal water-tube boiler, vertically baffled,
equipped with a chain grate, short ignition arch and short
flame travel, is frequently encountered. This type of set-
ting is a constant smoker. It is true that the smoke may
not at all times he dense enough to he a violation, hut
there is hardly a moment in the twenty-four hours dur-
ing which No. 1 or Xo. 2 smoke mi the Ringelmann chart
92
powei;
Vol. 11. No.
- n.it emitted. This is due in the volatile matter being
chilled by the nest of tubes before combustion can be corn-
el. Frequently the setting is erected with only 6-ft.
space from the floor line to the front header, so that con-
siderable remodeling is necessary before good results may
be expected.
The besl method of cleaning up these settings is by
laising the boiler or lowering the floor, and putting in
horizontal baffles. A good illustration of this is given
in Figs. 1 and 3 on pages 532-3 of the Oct. 13 issue.
Sometimes the boiler i- se< high enough so that only the
combustion-chamber floor need lie lowered when the hori-
zontal baffle i> put in. In any case, liberal space must
be provided in the combustion chamber to avoid ••bot-
tling" the ,ie;. . and therefore burning up the arches and
tiling. Occasionally, when floor space is to he had in
front of the boiler, it has been possible to pull out the
stoker ami gel enough flame travel to clean up the set-
ting.
A <-<\>r nf this kind. Fig. '■',. consists of a B. & W. boiler
with a Laclede-Christy chain -rate in ', ft. of headroom,
built out ; ft. from the gate to the flue caps and having
a 5-ft. flat ignition anh. followed with a l-ft. 7-in. sec-
ondary arch. Thi> unil operates smokelessly and may
lie considered satisfactory up to rated capacity. Of course,
Miib a setting cannot lie considered good for capacities
above rating, but it can be taken as a reconstruction possi-
bility where conditions permit.
iS^uiMs ©f ClhiainiE©© aim
[Son.
>r F^rimac*
B*i Moia,'. - 1 Smith*
SYNOPSIS .1 specific instance where the effi-
ciency of two 500-hp. Stirling boilers, each fitted
with two Roney stokers, was greatly increased by
enlarging the combustion chamber or furnace.
At the instance of E. .1. Burdick, superintendent nf
power, Detroit United Railway Co.. the writer in con-
junction with F. L. Fish.r. Chief Engineer of the Roches-
ter, Mich., power station, earned out at the company's
laboratory an extensive investigation of the rate at which
combustion progresses in Stirling boilers, each having two
Roney -inkers.
This investigation showed that completion of combus-
tion is delayed at a poinl too far back m the gas travel
when such boilers are lifted with Roney stokers and re-
stricted combustion chambers, as is the case when each
stoker is housed in a separate furnace and long combus-
tion arches are used. Combustion was never complete
short of the bottom of the second pass and at time- not
even half-way up the last or third pas-. This was mani-
festly bad practice resulting in the production of dense
smoke and relatively low efficiency.
It is obvious that the cure for this condition lay in
so designing the furnaces a- in assure quicker completion
of combustion before the gases turned downward into the
second pass. It was believed that less restriction of the
gases would give tin- resull and that less smoke would be
produced: higher efficiency ought also to be attained.
With a less restricted combustion chamber the volatile
constituents in the fuel would be distilled less rapidly,
owing to lower furnace temperatures, and less smoke
would result a- these product- would have time for com-
plete ignition before impinging on the relatively cool tube
surfa....
We determined to gradually cut away the long arches
and note the results after prolonged operation. In this
we were disappointed. (<>;■ the division wall in one of these
boiler furnace-, already weakened, gave way and let both
arches down. Tlier,- u;i- nothing to do hut t>i clear away
the mass of firebrick and gel the boiler back on the line as
soon as possible. Advantage was taken of this new -late
nf affairs by making a thorough study of the boile r
ation without arches, comparing this to the old opera-
tion with the arched furnaces.
The division wall was trimmed down to follow the line
of the mate- (inclined) and made <i in. higher. We now
had mie large high furnace with no division wall to break
up the flow of the furnai e gases. We found that we must
protect the front wall of the setting, so we extended the
coking arch 10 in. inside this wall, battering it back
against the wall, at the same time protecting the struc-
tural-steel frame at the front of the boiler. This gave
?i in. of coking arch, the only arch in the furnace. We
also increased the height of the first or front baffle one
foot, giving 13 sq.ft. more baffling surface, a longer gas-
travel, and a reduction of the breeching temperature.
These boilers have been in operation six months and
as a result of the efficiency attained we are similarly mod-
ifying all of these furnaces. It is expected to have a
Stirling boiler fitted with Murphy stokers in satisfactory
operation without any arch in a short time.
In all our power stations we reduce the results to a basis
of kilowatt-hours obtained per million heat unit- supplied
to the furnace-. The data given below show the results
obtained since taking out the long arches as against re-
sults with long arches — i.e., large, unrestricted combus-
tion -pa. es against small, confined -paces.
CI i.MTARATIVE OPERATION
Restricted Unrt
Spaces Spaces j
Combustion arch, is 72 None
•chief chemist and combustion engineer, Detroit United
Coking arch,
Division wall, in
Height above grate, in
Kw. hr. per million B.t.u.
Breeching temperature, deg. F.
COa average :tl the breeching, per cent
Smoke by Ring Lxann charts, average X
Temperatures in
Over tires, deg. F......
Bottom of irn.it tubes, deg. F
Top of tir-i pass, deg F
Bottom deg, F
Top of third pass, deg 1-
Ashes produced:
Ash-in-ashes, pel cent 69.34 79.74
Combustible in ashes, per cent 30.66 (by din
Draft losses — taking draft at breeching side of back damper as 100 per cent.j
Under grates, per cent B 2o S 2
ites, per cent
Top of fir>t pass, per cent
Bottom of sec 1 pass, jht cent
Top Of Our. I pass, pel rent
Boiler-side o\ back damper, p i
Breeching-side of back damper, pen
All draft readings were taken with the inclined tube ty] e of draft gage, reading
directly to 1 100-in. water pressure.
The electrical unit operated during this period con-
sisted of a 2000 kw, alternating-current generator driven
Full 6
17.50 23 53
560 558
9.00 12.50
Average less than No. 1
24o2 2092
2370 2000
1000 1175
690 710
570 55S
HI -,it
40 00
i- 50 .mi no
07 .Ml 69 §
02 Ml 93 Ml
loo no mo mi
January 19, 1915
PO W !•: i;
93
by ;i turbine fitted with a jet-type condenser. The load
varies from 1250 to 2500 kw. and is difficult to handle
economically because of frequent peak-load conditions
of shori duration.
The coal figures in the table include the daily three
and one-half to four hours of banking during the night.
All coal received is sampled and tested for heal value in
a standard Atwater bomb calorimeter and the wattmeters
are 'lucked frequently with master meters.
COAL FIRED (Average)
All coal is dried at 105 deg (' for one hour before testing. Coal received
Hi per cent, moisture :it the stations.
B t u. pet lb , ... ...13 962
Volatile mat ter, per cent 36 7,
Fixed carbon, per cent 54.33
Ash, per cent 8.90
Sulphur (Eschka), per cent 2.18
CONDENSER DATA (Average)
Condenser intake, temperature, d<-<: F 53.5
"scharge, temperature, deg
Showing the Old and the New Akches
The turbine water-rate is approximately 1 I lb. under
operating conditions. To handle the load requires that
the two boilers shall run at an average of from 160 to
1 75 per cent, of rating.
Points noted in the operation of these boilers with mod-
ified furnaces are :
1. Virtually no smoke is produced, a mere haze being
visible most of the time. No soot of a black, oily nature
is made, the accumulation on the tubes and around the
clean-out doors being more like fire-clay than soot.
2. More even heal absorption in the three banks of
tubes is attained. Tin.: front bank is greatly relieved of
the high heating effect of the gases as they tra.'rl over fin'
"Id anh. Both tin' second and (bird banks of lubes do
more work. The front bank will show longer life than
with ihr arched construction.
3. Deterioral £ the urates is less, due to lower
furnace temperatures.
I. Better quality flue gases are obtained, no CO being
found until the C02 reaches It; per rent. The average
Ci) figures given are somewhat town- than the true max-
imum because of the loss of from 1 to I.:, per cent CO,
in air of infiltration through the boiler settings.
5. Less coal and ash' s ,\fr handled, also [ess soot.
6. Cost of firebrick arches is eliminated.
, . Peak loads are carried more easily because we can
burn more coal in a given time than before.
8. The water level in the
boilers does not surge as be-
fore because the front bank of
tubes is heated almost uni-
formly throughout its length.
9. There seems to be no
need of a fourth pass in the
gas travel, although this might
improve the efficiency if it did
not unduly cut down the draft
available (natural draft; chim-
ney 200x10 ft.).
10. Combustion i s n o w
c | lifted before the ga e
turn downward into the second
pass, except when the boiler is
being pushed above 175 per
cent, of rating, at which times
combustion is carried further
into the passes, being com-
pleted at the middle of the
second pass. As these boilers
seldom exceed Hit) per cent, of
rating, the object of these ex-
periments may be said to have
I n accomplished. The slower
rate of distillation of the vola-
tile matter in the fuel together
with better mixing conditions
(volatile mattei- with oxygen )
is the secret of the elimination
of smoke.
We believe that these boilers
should be set 4 ft. higher than
at present, in which ease even
better results should be at-
tained with the given fuel.
Choice of fuel has much to
do with furnace and boiler-setting design; too little
attention is given to such items. With higher boiler set-
tings the brickwork is increased and the danger of leaky
settings is augmented, but with settings properly incased
this should not cause alarm.
y.
Tension on HruMlies should be set by the aid of a small
spring' balance, so that all the brushes will bear with an
equal pressure. This refers especially to high-speed ma-
chines; the pressure will vary from about 8 to 10 oz. per
sq.in. of brush surface in slow-speed machines up to 1 Vt lb.
in the high-speed types.
9-1
r o w e 1;
Vol. n, No. s
Gojaespefte Fii 111 Snag* f©2° IEsagnira©
By F. \Y. Salmon
Should the bed of a large engine 01 generator be filled
solid with concrete? A concrete filling will tend to ab-
sorb the vibration, reduce the noise from pounding and
jiw the bedplate a larger and better bearing upon the
foundation.
I have had bedplates filled with concrete, and it has
always proved advantageous. Some of these have been
filled before erection by turning the bedplate bottom-side
up and filling the space with a mixture of one part of
portland cement to three or four of clean sharp sand, and
allowing it to set.
If the engine or machine is already erected and loose
on the foundation, or acts like a piano sounding-board, it
can be easily Idled in the manlier shown in the illustra-
tion. A small air vent, '.j-in. pipe size, is tapped at the
highest point of each compartment or space. The old
grouting is channeled out and pipe .-I put in and well
grouted in place with equal parts of portland cement and
sand.
The charging cylinder /•' can then be screwed on and
connected to a supply of compressed air. Grout is put in.
the cylinder quickly closed, and a light pressure of air —
say 10 to 30 lb. — is turned on to drive the "rout into the
space to be filled. Do not allow any grout to stand in
the pipes or the cylinder, as it will set. Blow the grout
out clean each time as soon alter filling as possible and
at night take down cylinder />' and wash it (lean with
water.
Means of Filling Hoi, low Bedplates
In many cases this work is done gradually, a littie put
in one day, more the next, and so on. The pipe .1 should
extend nearly to the top of the inside of the frame in
every case, so that the grouting cannot run back into it,
while refilling the cylinder B.
In a few cases. I have had a little air pressure kept on
the top of the concrete during the time it was setting,
thus insuring the concrete being in good contact with
the inside of the bedplate at all points, but care must
be exercised to avoid springing the bedplate.
Sand, of course, may he \\>rA after a small layer of
concrete lias been introduced and has hardened, but solid
concrete is more desirable in every case as it reduces the
vibration and noise much better than sand and gives the
bed greater support.
My experience is that filling an engine or heavy ma-
chine bedplate with concrete costs but little and is a good
thins to do.
The illustration under the above heading in the issue
of Nov. 3, p. 646, is not correct in that threads F .should
Taper of Pipe fnd= i per Ft. =r6 per Inch
Depth of Thread (Ej-f^^
n = Number of Threads per Inch
rflat top and bottom* fer fed bjfom\<- -Perfect thread top ond—>i
\butJ]a1__fop\ bottom=(08Diom+4.8)X7T
... 4 'Threads .L,
Chamfer indie
FIG. I- LONGITUDINAL SECTION OF BRIGGS PIPE THREAD
*2 Threads
Briggs* Standard Pipe Thread
be perfect at top and bottom to agree with the text, and
the decimal point is missing in one formula. The new il-
lustration herewith is corrected in these particulars.
The Sediment in :i Boiler will accumulate in the portion
of the bottom near to the region of the bridge-wall in the
furnace; and if you have no such thing as a bridge-wall it
will accumulate where the fire is hottest. This is a result
of heat movements that send the hot water upward from
highly heated spots while the cooler water surrounding
sweeps in below, carrying with it sediment that builds a
little mound, if there is some one spot that is materially hot-
ter than the rest of the surface exposed to the fire.
In :■ Refrigerating Plant, if one wishes to obtain the best
results, the machinery should be run regularly and evenly;
otherwise things will go wrong. When excessive quantities
of liquid come back to the compressor, the compressor pis-
ton-rod stuffing-box will start to leak. It is bad practice to
tighten up on the stuffing-box glands because the rod con-
tracts when cold, but when the frost disappears it becomes
hot and expands again so that the leak will disappear; other-
wise the packing will burn when the rod expands. When
the frost comes back to the machine on account of low steam
pressure, which causes the machine to slow down, the best
thing to do is to shut the main liquid valve for a while or
stop the machine, after having pumped the low-pressure
side down to zero pressure, until the steam pressure rises
again.
Often, when the frost comes from one room very strongly,
it may back up into all the other returns and then it is
hard to tell by looking at them which is the one that is
doing the damage, or if there are several returns giving
trouble, which one freezes back the most. By wetting the
finger tips and touching each return, the one that sticks to
the fingers most readily is the one that should be tinned oH
some. It is good practice to have marks of some kind on
each expansion valve so placed that one can tell exactly
how much was turned on or off.
If a refrigerating machine is to be stopped for D little
while only, and the valves in the compressors are In good
order, the discharge stop valves may be left open, but never
the suction stop valve. This should be an engine-room rule.
Januai \ 19, L915
i'o \v ;; t;
'I'll.- author of the '\Mech; a] Engi rs' Poeketl i"
favors our correspondence columns with some observa-
tions upon mil' recenl remark that "scale or nil which
will cause no serious overheating of the metal when
three pounds an' evaporated per hour per square font of
heating surface i- very likely to make trouble when
the evaporal ion goes up to six or ten pounds." He points
out that with an average evaporation of three pounds
per square foot per hour there may he times, a- jusl
before firing a fresh supply of coal, when the rate ,,(
transmission of heat may hi' equivalent to an evaporation
greatly in excess el' this figure. That is. cue must net as
snme. because In- boiler averages three | ml- per square
foot per hour, that it may nut be working seme of the
time at the higher ami mere dangerous rate. Hi- obser-
vation that the temperature of the lire i- almost independ-
ent ei' tin; rate ef driving seems to he irrelevani it' it is
the driving ef the lire which is meant, hut it is difficult
to -ee. notwithstanding the reference to driving the boiler
which follows shortly, hew a hotter tire can he maintained
without a corresponding increase in the rate of evapora-
tion.
ILaceiras© ISM
It seems to he a uever-euding duty of ours to remind
engineers and legislators that some folks in this land are
guaranteed a right to a livelihood by the Constitution
of The United State-, if not by the exercise of that sense
of justice which civilized beings should manifest. If it
were not so easy for those el' the medical, pharmaceutical
and other professions to kill the children of men, their
possible victims would not require that they he certified
by a license of competency. If -team boilers and eng
were not veritable infernal machines in the hands of the
unskilled, if they had not caused an appalling loss of life
and property, the public would not seek to protei I itself
by inquiring into the correctness of their structure or the
fitness of their operators.
Safety is the object, the end, the all. of such laws. But
unfortunately, some engineers want to corner their local
markets for engineers and to do it under the guise of pub-
lic safety. Tiny want to say to their fellow en; ineers:
"Here, this territory is our.-. Xo matter how badly you
Died a job, or how good the job is that you are after, or
how competent you are to till it, you cannot have it because
you have not lived here one. three or a do/en year-."' Il
seem- almost incredible that men should attempt to legal-
ize and statutize their selfishness, yet they do. The laws
of Buffalo and New York City are well known exai pies,
but any law that denies the righ1 of alien- to folic w their
trade or profession in any state, on the <; ■ footing as
any citizen of that state, is unconstitutional and would he
nullified the |'u-t t • it was taken to court. Some engi-
neer- of New York City do not know this and have pro-
10 ed a hill for the creation of a separate bureau in the
department of licenses for the inspection of certain -team
boilers ami the examination and licensing of engii
and firemen. First, they wish to create the offices of sup-
erintendent of inspection, two general inspectors, tun ex-
aminers, tone boiler inspectors, and other subordinates,
and make all jobs appointive by the commissioner of li-
censes. It i- not deemed advisable to examine into the
competency of these appoint® -.
Applicants must he subjected to a physical ami practi-
cal test of their fitness. The practical part is all right,
but the physical te t i- non ense.
A man must he twenty-one year- old to get a fireman's
license. Candidly now, how many of those who partici-
pated in the making of thi ■ bill were firing boilers before
they were twenty-one? And do those who were believe
now that they were not men enough for their jobs? Cer-
tainly not. That section of the hill is also ridiculous.
Worst of all is the section which states that "Xo such
applicant (engineer) -hall receive a license as engineer
unless he is ahle to keep accurate data of the cost of
operation and maintenance of boilers and steam machin-
ery.''
Much a- we urge engineers to acquire such ability, we
would not include its possession as a license-law require-
ment, for law is for safety, not to confer special privi-
leges on certain classes, and safety does not depend on the
knowledge above mentioned. Some men can operate
plants safely who would make a poor showing before ex-
aminers as power-plant ee [lists.
Surely, the engineers of New York City will kill this
hill before its gets into Albany. Is it any wonder New
York State cannot enact a state license law?
Specifyairag Uiait SftaMoinv. Costs
In comparing the cost of generating plant.- it is always
interesting to reduce the figures to the unit hasis, hut in
many cases insufficient care is taken to specify just wdiat
units are in mind. In a typical instance the cost id' an
electric plant was found to vary from $45 to $125 per
kilowatt, accordiug to the selection of the factor divided
into tin' total outlay in money. It is important in making
such calculations to -tale whether one means cost per
kilowatt ef existing total rated capacity, cost on the basis
..f maximum sustained output for a protracted period of
specified length, cost per kilowatt of plant completed to
the ultimate capacity of the existing building, or what-
ever the factor of -election ma; be. Engineers are often
a hit i in this, with tic result that figures do not
always afford accurate deductions.
Someti -. for example, a coal-handling equipment
suital ■ losed ultimate capacity of a given
plant is provided long before all the engine or turbo units
planned for have be n installed. If the full cost of this
96
I'd w E I!
Vol. U, Ni
equipment is included in the unit determination for the
station on the basis of perhaps a half of the ultimate
number of generators and boiler batteries, one gets a
different result from that obtained by making an allow-
ance for that portion of the coal-handling plant required
liv present service and making a note to that effect on
the estimate sheet.
Similarly, when a few units are housed in a building
large enough for a substantia] increase in capacity, one
gets a relatively high building charge if a cost determina-
tion is made on the basis of the existing generating units.
Figures of this kind are instructive and well worth as-
sembling, but where they are prepared for an installa-
tion not yet complete according to the full plan-. Ilia
fact should be made known in presenting unit cost data.
so that a reasonable allowance ran he made by those t'>
whom the data are submitted.
It is often needless to attempt to separate that part of
the cost of buildings or auxiliary apparatus such as stacks
and condensing water tunnels chargeable to present plant
from tin: ultimate station capacity cost, for in very huge
stations the boiler batteries and main units cost so much
more than the auxiliaries that a considerable variation in
the outlay for the latter produces but a comparatively
small change in the unit result. That is. a building
with sufficient lions-' room to accommodate four 15,000-
kw. turbo units and their necessary boilers will probably
-t enough more for the fourth unit to render value-
less figures of unit outlay based on the total building
space, even where only three machines are at first put in.
To return to the starting point, one may figure unit
cosl on rtv basis he pleases, and with profit, but unless
that basis is definitely specified along with the figures de-
fined, misinterpretations ami wrong comparisons are
likeh to spring up and cause trouble all around.
disbursements made necessary by the trip, does the en-
E nicer positive harm.
The "boss" ma\ not think anything about the matter,
and then, again, he may. lie may say to himself some
time, "Johnson has gone over to Erie and gut just the
figures 1 wanted: he has put them down in the way I
like: that fellow's got a clear bead ami his expense ac-
count shows that be has some business horse sense besides
knowing a lot about steam engines and generators. Fin
going to I eep rrn eye on him and see it I can't work him
up to take -nine of these details off my mind, and maybe
make him assistant superintendent some day." There is
nothing impossible about such a train of thought as
this, and while it does not run through the individual
employer's mind often, it is mighty important when it
does — to the fellow who is striving to get ahead.
Needless to say. the right kind of a man will be as
careful about squandering his employer's money as bis
own. This does nut mean stopping at the cheapest hotels,
lor a first-class concern will wish its representatives to
travel in reasonable comfort.
A- one of the auxiliary matters, the proper handling
nf which will contribute to the sum total of impressions
which lead to good repute, the engineer's expense account
when away from home deserves thoughtful consideration.
Send us the story of any piece of rank stupidity on the
part of a power-plant employee that to your mind beats
those in "Some Original Ideas." page SI. dust at pres-
i nt the fellow who gilded the commutator holds the palm.
We do not wish to give much space to accounts of fool-
ishness, but a limited number of the best letters received
wdl lie used. They will amuse all and instruct some per-
haps.
('u tli- rare oltasioiis when operating engineers are
-"•nt on business trips, they should realize the importance
of their expense accounts. The way in which such a -
counts are rendered makes or mars the engineer's business
reputation, and probably will affect his future advance-
ment. Artists. s< ientists and even practical engineers arc
popularly considered as constitutionally unbusinesslike,
and the more one studies the reasons for personal ad-
vani "un'iif. the more convincing is the e\ idem e that clear-
cut thinking and writing, methodical ways of doing
things and an appreciation of the monetary side of affairs
are powerful factors in the advancement of technical i 'en
lo positions of executive responsibility.
The expense account is practically as important in the
impression it mak s upon the employer or superior officer
as is the report of tic engineer's trip. A man ma
to a distant city, obtain the desired data, embody i; in
a valuable report and return home feeling that h- has
"made good" at the task in hand, hut unless he turns in
an expense account which can be roughly checked or
audited by the man who "0. K.'s" the hill, he misse- a
real opportunity. A slovenly penciled memorandum of
funds expended or a carelessly compiled group of items
which yield no definite information as to the cost of main
outlays, like transportation, hotel fare, cab or horse hire,
telephone and telegraph expenses or important incidental
The section on Power-Plant Design concluded with
hist issue. Four individual lessons not classified as a
section, as Mere most of the previous ones, will appear, be-
ginning with this issue, and these will end the Study
Course, for the present at least. These last four lessons
will be: "The Conversion of Energy" (page 103), "The
Efficiency id' Heat Engines," "Heat-Engine Cycles." and
"Steam-Engine Cycle-."
:.:
Those who bind their volumes of l'ow er, or who desire
an index to facilitate reference to the filed copies, can have
such an index h\ oimpl) signifying their desire to the
Subscription Department of Power. An index is printed
upon the completion of each half year, and is furnished
I I'll' to all wlio care to have it.
Out in Ohio the following is what they require in an
engineer-janitor:
ENGINEER-JANITOR for large building; must be a man
of eood habits and willing- to work, otherwise we cannot use
you. State i , size of family, experience; give names and
addresses of four responsible parties ;is references.
If this is a movement against race sui ide we could
suggest further qualifications with perhaps a little more
emphasis on the "experience." for anyone in charge "I
a -team boiler has it in his power to reduce population.
January 19, 1915 POWEE
i.i.i ,.,,,'.... i ■ : ■ : i ' ■ . . . . i : ,
©mF(
mm mi
De2*a©iac© w
During a severe electrical storm in northwestern Ohio
an unusual phenomenon was produced by lightning on a
rotary converter. The machine is part of a portable sub-
station located in a box-car and which may be operated in
parallel with the permanent substations on any desired
section of the line.
No lightning protection was provided either on the
13,000-volt, alternating-current side or the 600-volt di-
rect-current trolley side, the operator having instructions
to shut down during lightning storms and pull all the
switches.
Diagram, Showing TVheue Arcing Occurred
At the beginning of this particular storm, the operator
pulled all the switches, consisting of the high-tension al-
ternating-current switch, low-voltage starting and run-
ning alternating-current switches, the direct-current cir-
cuit-breaker and switches, the field breakup switch and
the shunt-field switch.
Following an intense flash of lightning, the converter
started to run, the direction of rotation being reversed,
and the speed increasing at an enormous rate. The insu-
lation on the wiring back of the switchboard was afire
and produced a dense smoke which cut off a view of the
leads and connections. As the machine had acquired such
a high speed that it was likely to go to pieces, due to the
centrifugal force on the armature, the operator telephoned
the power station and ordered the power off the lines. This
was immediately done, whereupon the converter came to
rest, after a long period. The fire back of the switchboard
was then put out.
An inspection of the rear of the switchboard revealed
the fact that the lightning had struck the trolley at some
point in the near vicinity and the heavy rush of current
accompanying it had punctured the insulation and arced
across two leads which were close together on the back of
the switchboard. One of these leads was from the trolley
to the direct-current busbar and the other was from the di-
rect-current side of the converter to the bottom point of
the direct-current switch. The trolley-to-rail current
maintained this arc and flowed to the direct-current end
of the converter which started as a series motor with no
load. The sketch will make this clear. The only damage
inflicted was upon the insulation at the rear of the switch-
board, the converter not being injured in any way.
Frank W. Swift.
Toledo, Ohio.
SIsinipIlafyaEag IR.ejp©:^^ ©if IB©!I1©2'
Mr. Morrison's letter in the Nov. 10 issue certainly
touches upon a matter that requires to be put into clearer
meaning than is usual at present. To simplify boiler
reports, and make them of value to both directors ami
himself, the writer employs the following form:
Actual weight of water evaporated per pound of fuel (name
of fuel).
Pounds of water evaporated for one cent.
Total cost to evaporate 1000 lb. of water, including labor.
Underneath lor the writer's own information are:
Average percentage of CO2.
Average temperature of feed water.
Average temperature of gases to chimney.
B.t.u. value of coal.
Amount of ash for given weight of coal.
With the first three items the directors can understand
easily what the boiler plant is doing, and the remaining
figures give the engineer all the particulars he really
wants to know. If there are any peculiarities observed
during the test, these are added in a footnote.
E. E. Pearce.
Rochdale, Eng.
Saag>g|esitedl Use ©f Temnms Vsyjp©^
The terms vapor, steam and gas as applied to the gas-
like condition of water expanded by heat, although mean-
ing the same thing, are, unfortunately, often used as
though referring to things that differ in their properties.
We read of steam pressure and vapor pressure; that water
flashed into steam or vapor. Often in books the words
vapor and steam are both used; perhaps to avoid the too
frequent use of either word.
To one familiar with the definitions there is no mental
effort required to connect the two with a single meaning,
but to the beginners this practice is more or less confusing,
and still more so by steam being sometimes called a gas.
I have recently asked a number of engineers what they
understood by these terms. The majority had the correct
idea, but some had a hazy impression of some difference.
One said that he understood vapor to be that which was
given off the surface of water at ordinary temperatures,
or below 212 deg., and that steam was given off at above
212 deg. This man knew that the composition of both was
the same as water, but thought the two terms were used
as a convenience to distinguish the difference in tern-
US
POWEB
Vol. 41, No. 3
perature. He understood the term gas to mean super-
heated steam.
Now, if we must use the words vapor, steam and gas as
applied to the expanded condition of water, it seems to me
that the ideas of the engineer quoted would be more logi-
cal than mixing or using the terms interchangeably. We
would then have vapor at temperatures below 212 deg.,
steam at above 212 deg. and gas as superheated steam.
C. 0. Sandstbo.m.
Kansas City, Mo.
w Snrosna us s=e©gain\g,
I overcame a difficulty similar to that described by
A. T. Rowe, page 788, Dec. 1, at a place where the
<" Asbestos
BOX VllofXI) A Blowoff V VI. VK
temperature often drops to 30 deg. below zero. I built
a double-walled box around the blowoff valve and tilled
the space between the walls with asbestos. The cover
was inclined to allow the rain or snow to run off and was
removable to give- access to the valve when necessary.
A handle B is used to open and close the blowoff
valve K without removing the cover. A space where
the pipe passes through the wall at A admits a small
amount of beat to the box. The pipe / has a slight
slant so thai no water can remain in it. and it lias never
frozen up during several year-' use.
James E. Noble.
Toronto, Out.
F©f<ciiag| Boalss's sur&dl IB\iair§ftiiir&gg
In the illustrated article on "Burst Boiler Tube" in
your issue of December s. page 805, the statement is
made that "scale or oil, which will cause no serious over-
heating of the metal when three pounds are evaporated
per bom' per square fool of beating surface, is very likely
to make trouble when the evaporation goes uj to six or
ten." This statement is apt to give an unwarranted
i n e of security to owners of boilers which are usually
not driven at a rate of over three pounds evaporation per
hour per square fool of heating surface. The fact is that
when the rate of driving of a boiler averages this figure,
there are times, whin the fire is at its brightest, just be-
fore firing a fresh supplj of coal, when the rate of trans-
mission of heat may be equivalent to an evaporation great-
ly in excess of tin's figure.
Also, the rate of transmission of heat through the sur-
face of the bottom half of the lower row of tubes, imme-
diately above the fire, depends on the temperature of the
fire, the temperature of the water in the tube, and the
resistance to transmission of heat of any layer of scale or
oil which may be on the surface of the tube. The tem-
perature of the fire is almost independent of the rate of
driving. It depends chiefly on the dryness of the coal,
the completeness of the combustion, and the amount of
excess air over that necessary to insure complete com-
bustion. It is quite possible with either anthracite or
semi-bituminous coal to have a temperature of 3000 deg.
F. in the furnace, whether the boiler is driven at a mod-
erate or at a high rate. Given a condition of firing which
produces such a temperature, the rate of driving per
square foot of heating surface depends upon the amount
of heating surface that is provided for the absorption
of the heat, and as this surface, or nearly all of it. is
beyond the lower row of tubes immediately over the fire,
it can have nothing x<> do with the establishing of a con-
dition which would cause the burning out of a tube in
the lower row.
If statistics of burst boiler tubes should show that
bursting is more frequent at high rates of evaporation,
ii does not follow that the high rate of evaporation in
itself is the cause of the more frequent burstings. It
is more probable that the greater frequency is due to the
greater quantity of scale that is deposited in a given
time when the boiler is driven at a high rate, and the
conclusion to be drawn from this is that with high rates
of evaporation it becomes necessary to use feed water
that is purified before entering the boiler.
Wm. Kent.
XeW Yolk.
V
Pump
We had considerable trouble by vapor being carried over
from the surface condenser to the vacuum pump and caus-
ing water-hammer. It was necessary to stop the pump
Inlet i
PS""
Reservoir for Condensate
and relieve the vacuum before the water would drain out,
and as this usually occurred during the heavy-load period
it called for fast work.
The quickest way was to slack off the valve-chest cover,
but as the water accumulated to a dangerous extent.
four or five times on a watch, it became a serious matter.
To overcome this, I connected a 6-ft. length of 4-in.
pipe, with a reducing elbow and a l-in. globe valve at
each end, to the bottom of the valve chest. Valve .{ at the
January 19, 191,
1'iiWEH
9!)
end next to the pump should be left open and B at tin
other end closed until water accumulates in the pipe : then
A is closed and B opened to drain the water into tin
sewer. Pet-cock C is opened to admit air during tin
draining process. \\ ith a reseivair of tins capacity it is
only accessary to drain out once in twenty-four hours.
V. < I'DONNELL.
Coscob, Conn.
IL^ir^e §8iva!rag| aira Silo ft© 31 ILa Sallll©
The diagram shown was taken from the high-pressure
cylinder of a Corliss cross-compound condensing engine
connected to a centrifugal pump. One valve stem was
so twisted that the valve had a late admission, as shown.
and the speed of the engine was reduced from 135 to l'.'s
r.p.m.
After the key was taken out, the valve was turned until
Diagram When Stem Was Twisted: New Key
it was in the right position and an offset key was made
to suit the new position instead of turning the stem over
and cutting a new keyway. The valve required no fur-
ther adjustment.
Lawrence Kjekuief
Kansas City. Mo.
Iinnipifopes'Sy Fiimislhiedl P^unnraps
Referring to the letter on p. 892, Dec. 22 issue, under
the above caption, I agree that stuffing-boxes are gener-
ally too shallow, but find that better results can be ob-
tained with the bottom of the stuffing-box and the face
of the gland square than at an angle. The packing
should touch the rod from one end of the stuffing-box
to the other with a moderate pressure over a large area
rather than a concentrated pressure on a small area at
the two ends, causing excessive local friction and wear.
I have designed and used many stuffing-boxes for
steam, water and vacuum and have never bad any diffi-
culty with square faces. The operating engineer is quick
to see the advantage of having each piece of packing in
the box doing something like its share of the work. I
have packed %-in. reciprocating valve stems against 150-
lb. pressure with soft packing in a stuffing-box 2V2 in.
deep. The glands were held by two %-in. studs screwed
up snugly with a small wrench, causing very little fric-
tion.
Good results have been obtained with a shallow stuf-
fing-box having 30 deg. beveled bottom and gland face
in packing a stationary pipe extending through a jacket
against a steam pressure of 150 lb. In this case the stuf-
fing-box was only 1 in. deep for y2-m. pipe, the object
of the bevel being to obtain a tight joint in a small space
regardless of friction.
E. P. Haines.
Baltimore, Md.
To anyone not acquainted with the facts, the attempt
on page <:;> of Jan. 12 to refute the article appearing in
the Nov. :: issue of Powee might appear like an able de-
fense of the former high cost of operation, but as a matter
of fact it is misleading, to say the least. In the following
reply it is the writer's intention to take each paragraph in
turn and to give the facts in each case. Before doing this,
I wish to state that the figures in Mr. Wilson's article are
correct, and this statement is verified by the accompanying
letter from the auditor of the hotel, who has held that po-
sition since February, 1910. The deductions made and the
reasons given for the savings are also true in every re-
spect. 1 know personally that it was not the author's
intention to find fault in any way with my predecessor
or his method of running the plant. There had been a
difference in operating cost of $45,000 per year, and to tell
how such an enormous saving had been made was the sole
purpose of the article. This was done accurately. I do
not take any glory unto myself for the saving, as in my
opinion any engineer worthy of the name could have ef-
fected the same results by keeping on the job and by win-
ning the full confidence of his men and his employer.
Following is my reply, in which the numbered paragraphs
refer to those of similar sequence in the preceding letter.
1. Mr. Lawrence admits that be was on the job IS
months before the hotel was opened. He bad to pass on
all the mechanical equipment before it was contracted for
and also to O.K. the same before it was accepted. It was
all contract work and all changes were up to the contrac-
tor. Certainly hotel help was not used to make contrac-
tor's changes. After the hotel opened all material and
any labor done by the plant force which did not apply to
the engineering department was charged to "Improvement
and Betterments.'" The department was given credit
and to the full amount specified by the engineer. Although
Mr. Lawrence does not actually say that it was charged
to bis department, he infers that it was ami overlooks the
fact that the data given in the article do not go back of
1910. It will be seen in Table 2 of the article that the
labor charges are practically the same for the four years
given. The maintenance and supply items for 11)10
and 1911 are excessive, due to lax operating methods, but
the items are made up of legitimate power-plant charges.
2. By the present management it is also required
that the house be thoroughly ventilated at all times, but
as there were certain ventilating fans performing certain
functions at different times, it was possible, by making a
few changes, to arrange a schedule of fan operation which
permitted shutting down some of the fans part of the
time and the saving of considerable power. Under former
conditions it was impossible to properly ventilate and cool
one of the dining rooms until the air ducts had been en-
larged and an additional fan installed, having a capacity
of 6000 cu.ft. per nun. During the summer months this
room bad been closed as it was so hot nobody could stay
in it. For the past two years it has been open every day.
Besides, a complete ventilating system has been installed
in the laundry, where formerly there was no ventilation
at all. All other fans are being run the same as ever,
but only when needed and not haphazard as before. In-
stead of shutting down motors, except as before stated
where they are run on schedule, three additional motors
100
P 0 W E B
Vol. 41, No. 3
have been installed in the laundry, two in the nine-
teenth-floor kitchen, one in the eighteenth-flooi kitch-
en, and two in the sub-basement. Regarding cooling
and refrigeration, a more even and lower temperature
is maintained in the different rooms than ever before,
and an additional 6000 eu.l't. of air per min. is supplied.
This is not cutting down on service. The figures in the
article also show that considerably more ice was made
The machines are mm operated on exhaust steam and not
on live steam, as in former days. This is an item of sav-
ing. It is true that 25-watt tungsten lamps have been
substituted in part for 16-cp. carbon lights. Any intelli-
gent engineer would do the same, and it is inconceivable
that any manager would refuse a better light costing less
for maintenance and current providing he was properly
informed of the facts.
3. The steam traps certainly did have an elaborate sys-
tem of piping and must have been put in on the time and
material basis. There were 15 on the high-pressure lines
in the engine and boiler rooms. On the discharge line of
each trap was a valve and between this valve and the trap
a %-in. valve for detecting leakage of steam. Upon tak-
ing charge. I went to each trap, closed the valve in the
discharge line and opened the try-valve. Without any
exception, not water but steam under boiler pressure blew
out. An investigation showed that the seats and valves of
the traps were badly worn, and in some cases the valve
was completely eaten away, giving a direct passage for the
steam. The traps discharged to an open heater with cast-
iron sections, and this in turn was connected with the ex-
pansion tank, from which risers to the heating system and
the atmospheric exhaust were taken off. An employee
who has been under both managements reports that on one
occasion a repair was to be made to the heater. The
valve between the expansion tank and the heater had been
closed Shortly afterward the latter exploded, and the
cause was live steam from the traps.
4. It is common knowledge that as a hotel or any
building gets older it requires mure attention and espe-
cially more sweeping This is true in the present case,
and the hotel is noted for its cleanliness. As stated,
there are three vacuum machines of the inspirator type
which use steam at boiler pressure and carry a vacuum of
1".' in. On each machine is a control valve to automatical-
ly shut off the steam when the proper vacuum is reached.
\\ ben the writer took charge all three machines were ;n
operation and blowing continually without a sign of cut-
off. The machines were overhauled, and it was found that
one would do the work and still cut off intermittently.
The same number of sweepers are in operation, and, as
the hotel is getting older, more sweeping is necessary. One
machine does the work very efficiently
5. These lights were installed during the summer be-
fore the writer took charge, for illumination during the
roof-garden season. The same number of lights are still
there and are burning every night of the season There
is no change in the schedule. Instead of reducing the
lighting it has been increased. An addition of 825
twenty-five-watt tungsten bonier lights has been made at
the fourth floor, also loot) ten-watt lamps in a large roof
sign, and numerous table fixtures, each containing three
10-watt tungstens
G Changes are continually being made, and more
now than wbei, 1 first took charge. The nineteenth-floor
kitchen has been entirely remodeled and several additional
steam-using appliances installed. A new kitchen has also
gone in on the eighteenth floor, with coffee urns, soup
heaters, steam tables, etc. Besides, a number of steam-
using appliances have been added to the laundry. All of
this work was done by the engineering department. Con-
trary to the inference made by Mr. Lawrence, the work
was charged to "Improvement and Betterments" and the
power plant was allowed a credit.
',. All engineers in Chicago know what it was to get
coal in 1010, but that was only during the months of
June. July and August. At that time I was in charge
of a hotel plant three times the size of this plant and
made a better showing than in the previous years. In
Table 2 in the article the difference in the coal bills for
1910 and 1011 is $3500, which, divided by the tonnage for
the year, amounts to only a few cents. Under conditions
as I found them here, it was impossible to burn anything
but a good grade of washed coal, as with inferior coal the
combustible matter in the ash would be excessive. As to
records, the boiler-room foreman who was on the job then
and is still in the same capacity states that no records of
coal were kept other than the amount of coal coming into
the building: also that the water meter was out of repair
continuously and was inaccurate, and before it could be
used on the tests cited it hail to be completely overhauled.
Readings from it could not have been '"absolutely cor-
rect,*' and it is rather difficult to see how the daily coal
consumption could even be estimated with any degree of
accuracy. Steam coming from the exhaust head on the
La Salle, even on the coldest days, was a matter of com-
ment among engineers of the city. Besides it is difficult
to see how evaporation could lie '"kept up to the highest
possible point at all times" with a C02 reading of li/o to 2
per cent., which is all that could be obtained by the writer
until the furnace conditions were changed.
8. To operate the electrical units at the best load
factor, the same means were at the disposal of my prede-
cessor. Even with the larger load he was carrying, due
to inefficiency in more ways than one, it would not have
been necessary to operate more than one unit at a time.
In the very tests to which he refers a change of schedule
was recommended, which would have effected a saving es-
timated at $ 1 5 ] ler day. or $5 1 7 5 per year. The two meth-
od- of operation' were outlined in the artii le. I have fol-
the plan of operating the second unit from ? a.m.
to •"' p.m., the largest unit from 5 p.m. to 1 a.m., and
the smallest the balance of the night. This allows each
unit to operate at its highest efficiency and has proved a
\ei\ flexible arrangement. All of the rooms are still
cooled in the summer, as previously stated. Furthermore,
hourly temperature readings are taken. By supplying an
additional 6000 cu.ft. of air per min.. it was possible to re-
open the German restaurant during the hot months. This
does not look like a discontinuance of service. The vari-
ous services required have been maintained, but much
more efficiently than in the past. As to the plant speaking
for itself, 1 am willing to have it. I do not consider an
engine room served by fluttering arc lamps well lighted.
It now- has clusters of 25-watt tungstens. All pipe joints
and valve- stems are kept packed and steam tight. When
the writer took charge, there were leaks in the lie;
stop valves, auxiliary valves, etc. In fact, on top of the
boilers conversation was impossible, and in any part of
the plant it could oiilv be carried on under difficulties. The
boiler tubes were in bad condition and a large number had
January 19, 1915 POWER 101
to be replaced. Water leaking at the ends of t|, . fire during the periods shown in Table - of the Nov 3 issue
SfflS Tl r f S"nt and !',,nn"' ' l,anl ^^ °f I>mV":'; W6re 8U legltimate ha g* 2 that department
Ktf The remodent llfTt^ '^ °f *?? i ^ ^ 8ervices °f the ^^ deParta^ ^
' /7eTll,lB?f the ^maces was accurately been required for changes or additions to construction
described m the article. Due to this it was possible to use full credit has „ ,ivcn on the Tm^nfsh^tvZe
an inferior coal costing less per ton. As to the condition and materials used
ol the engines, the following sentence of a letter from the It should he noted that your correspondent particular!,
builders to the writer will be illuminating: "I want to refers to the period of SeptenTbe Z 1
congn, ulate you on the nice running of your engines, whereas the Nov. 3 issue of Powkk gives no Wes whit
winch have undoubted v taken tune and great care to ever for that period. It may be that he has some sne
Mng mto line, as they have been fearfully abused." cific item ,n mind, and if such is the case I would" kl
9. Mr. Lawrence could not be expected to know that to investigate and report on it after hearing from him
he knows exaetlj what he is doing in the plant and fur- economies effected in the engineer's department durine
ETa to tTfot f "V^ff a™kf °f C°al *"'! *> ^r 19*4 -ke a still more favora^ompar S
v,a er As to the tests mentioned by Mr. Lawrence and with previous years' operations, especially in view of the
punted m part in his letter, I have nothing to say. There continued increase in the hotel's business-
is no occasion to bring another party into the controversy, m ,T ' ~
and for that matter it is not necessary, as the results . ,W/ \F™K™'
obtained speak for themselves. These were given accu- Chit,a„() 111 '
rately in the article by Mr. Wilson, as well as a careful '
analysis of how the saving was effected. *
. 10- ln the artiele aPPearing in the Nov. 3 issue, the B©£©©$niag AffiffiffiaOEaS^ ILe^Jfts
size ot the new elevator pump was given, but no special T ., n
leference was made to it as it was not installed until last , *, J lssue' Mr- Anders011 takes exception to
August. The latest records given in the article were for m7 mf, (see N°V- 3 1SBUe' P- 656> under Eobert G-
the year 1913. As to the necessity of installing this £-■ ^ °f detectmS ammonia leaks in brine tanks.
pump, it may be stated that the three pumps originallv , m?™od 1S t0 empty the tank» -M inside ;t and test
installed had to be maintained in service from G am to , a sulPhur stk'k while the pressure is on
12 midnight, and at times under the former management T'US 1S the best metho(1> but how many engi-
they were so hard pressed that it was a common occur- neers, aTe g°mg t0 take the tr°uble to pumP out the tank-
rence for the accumulator to hit the bottom nearly wreck- ° - • m , e °f ft whlle :t ls c'old and slimy and con"
ing the duplex pumps before the attendants could reach sclel]tl0llsly aPPJy the sulphur stick to every joint? There
[the throttle. Apart from better elevator service the new J™ agree Wlth Mr' Anderson that there will be a
pump has effected a saving in coal, as the coal 'costs for ,?V p°imds of ammonia lost by using my method, also
corresponding months in 1913 and 1914 will show sulphur stick will locate ammonia leaks more
coal cost per month J"**?? tha° ^T* ^ °T Nessler's sohlti°n, but when
1913 i914 ne claims that he can detect ammonia in brine by smell
!seupgten'ber ■ *VilMl $3nrlU.io before it can be detected with litmus paper or the solu-
october :::::::::::::::::::: 3471:41 litlit tion, 1 must say 1 am skeptical.
November •C>'><1 «« 9cqs'.)v u . -, *
Mr. Anderson states that to test the brine-tank coils
In August the pump was only run two weeks, as the properly one should reduce the pressure to 5 lb. before
builders still had some work to do on it. In September testing. The higher the pressure the more prominent the
and October, it was run three weeks each month and in leak and the more readily it may be detected.
November nearly four weeks. The use of the words "discharge tanks" in my article
The new hot-water heater was badly needed. Before it is wrong. The manuscript read "discharge lines."
was installed, it was necessary to carry 3 to 4 lb. back Mr- Anderson claims that some losses are due to the
pressure on the entire system to furnish enough hot water disintegration of the ammonia. This is questionable.
tor bathing, and even then there were many complaints Water should not lie present in the ammonia in a prop-
aver the low temperature of the water. The new heater erbT managed compression plant. In an absorption plant
bas done away with this trouble, and the building can be it is of course different. Many operators claim that rnn-
leated by steam under a pressure of 1 lb. ning with cold rods draws moisture into the cylinder
The above covers all points brought up by Mr. Law- with each stroke of the machine, due to the moisture
•ence. Numerous other items might be mentioned to clinging to the cold rod and being drawn in with it.
mm how the saving given in the artiele was effected, and l have seen considerable water get into the system with
f desired the writer can go into fuller detail at a future the oil by using the oil over again and not having it prop-
late. It will be of interest to notice in the auditor's crl.v filtered. Moisture will also get into the system
etter that the saving last year was even greater than in "'ben the expansion coil or suction line is opened and
1913, and more work has been done than ever before. ]elt open; the moisture precipitates on the cold surfaces
W. W. Bird, and accumulates in the pipes and when the system is put
Chief Engineer, Hotel La .Salle. m operation again is swept along with the ammonia.
Chicago, 111. If steam is used to clean the oil out of the system
T, and it is not thoroughly blown out with air afterward
I have served the Hotel La Salle Co. in the capacity of ■ the condensation will remain in the pipe atten,ard'
rnowle^eT T™^ wV" *? **, ^ °f "* Tuo.LU. Thhkstok.
knowledge the charges made to the engineer's department Chicago, 111.
102 POWEK Vol. 41, No. 3
niiiiiiiiiiiiiiiimiiiiiiiiiiiiiiiiiiiim^^
Iirnqjuiiri®© of Gremeral Imterestt
liniiiiiiiii iiniiiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiini niiiiiniiiiiiiiii lililillllililillllllllllllllllllllllllllllllllllllllllllinillllililllllllllllll iiilliiiiilllllliiliiiiiiiiiiini iiiniiiiiiiiiniiiiniiiiiiilllllllllillliiilliliiiilllillilllliillillllllinuiiuilllllillliuillllllllilllililliiiiiiiliiiililiii iiiiiiiiiiiiiiiniiiiuiiiiiuiiiiS
Inspection of Storage Batteries — How often should storage
batteries be inspected?
C. E. C.
It is well to thoroughly inspect them at least once a week,
using a special lamp for the purpose.
Bar-to-Bnr Test of Armature — When making a bar-to-bar
test of a dynamo or motor, what would a sudden drop of
milli-volt reading indicate?
Z. H.
A sudden drop in the reading would indicate a short cir-
cuit, either between the bars themselves or between the
windings connected to the respective bars.
Pitting Due to Presence of Fatty Acids — "What would
cause oily feed water returned from an exhaust steam-heat
ing system to pit boiler tubes?
R. M. C.
Pitting might be due to fatty acids contained in animal
or vegetable oil used as an adulterant of the engine cylinder
oil.
Anehor Ice — What is anchor ice and how is it formed?
R. C. M.
Anchor ice or ground ice consists of needles and thin
scales of ice which form in moving water and sometimes on
the bottom of still water. They usually cease to form after
the body of water has become frozen over. On coming in
contact with submerged objects these particles of ice adhere
and soon form large masses difficult to dislodge.
Quality of Steam Gathered near the Surface of the Water
— What would be the quality of steam gathered in a petti-
coat pipe near the surface of the water in a boiler as com-
pared with steam taken from the top of the boiler?
J. E. N.
In the process of ebullition the globules of steam, in rising
from the body of water to the surface, entrain water which
is unevaporated and which is projected above the surface of
the main body of water. Unless the steam is superheated
there will generally be some water thus entrained that will
be carried to every part of the steam space of the boiler. It
is usually the case that the nearer the disengaging surface of
the water, the larger will be the proportion of water thus
entrained by the steam, hence steam gathered near the sur-
face of the water by a petticoat pipe would be much wetter
than steam taken from the top of the boiler.
Changing Governor Pulley — A belt-driven governor regu-
lates the speed of an engine to SO r.p.m. The governor driv-
ing pulley on the main shaft is 12 in. diameter and the re-
ceiving pulley on the governor is 7 in. diameter. To what
size should the governor receiving pulley be increased to
regulate the engine to 90 r.p.m.?
With 80 r.p.m. of the engine the speed of the governor
SO X 12
pulley is ■ r.p.m., and as practically the same speed ot
7
governor would be required, then for regulation at 90 r.p.m.
of the engine shaft, the governor receiving pulley should be
/80 :< 12s
I — — I or 7% in. dio
(90 X 12)
Original Babbitt Metal — What
babbitt metal?
the original recipe for
L. J.
The original recipe proposed by the inventor, Isaac Bab-
bitt, a brass founder, of Boston, Mass., was 4 lb. of copper,
8 lb. of antimony and 21 lb. of tin = 36 lb. of mixture called
hardening, and to every pound of hardening 2 lb. of tin was
added, so that the completed mixture was in the proportions:
4 lb. of copper, S lb. of antimony and 96 lb. of Banca tin or
1 : 2 : 24. For making the alloy the melting must be gradual
or the antimony and tin will largely separate from the copper
and form oxides or dross on the surface. Thus 4 lb. of copper
Is melted first, then 12 lb. of tin and S lb. regulus of anti-
mony are added slowly to the molten copper, to which 12 lb.
more of tin is added to form the hardening. Then for use
with each pound of this. 2 lb. of Banca tin is melted. The
surface should be covered with pulverized charcoal and a
small portion of sal ammoniac. Previous to pouring the mix-
ture it should be well stirred.
Evaporation per Pound of Fuel Oil — What would be the
rate of evaporation per pound of fuel oil having a calorific
value of IS, 500 B.t.u. per pound with a boiler efficiency of
75 per cent., a steam pressure of 50 lb. gage and a feed-water
temperature of 135 deg. P.?
S. F.
With 75 per cent, boiler efficiency there would be
0.75 X IS, 500 = 13,875 B.t.u.
realized per pound of fuel. As each pound of feed water
raised to 50 lb. gage pressure, or about 65 lb. abs., would
contain 117S.5 B.t.u. above 32 deg. F., and as with feed water
at 135 deg. F., or 135 — 32 = 103 deg. F. above 32 deg. F..
each pound would receive 117S.5 — - 103 = 1075.5 B.t.u., then
13.S75
or 12.9 lb. of water would be evaporated per pound
1075.5
of fuel.
Effect of Temperature on Wire Resistance — If the resist-
ance of 1000 ft. of copper wire at 75 deg. F. is 100 ohms, what
would be the resistance per foot at 90 deg. F. ?
R. J.
The resistance of copper wire increases with an increased
temperature. The formula to be employed is:
R2 = Rt + C X Ri (To — T,),
where
R2 = The resistance, hot;
R! — The resistance, cold;
C = The temperature coefficient, depending upon the
metal, which in the case of annealed copper aver-
ages about 0.00223;
Ti = Temperature, cold;
T2 = Temperature, hot.
Hence, where the resistance of 1000 ft. of copper wire at
75 deg. is 100 ohms, the resistance per foot at 90 deg. F.
would be
R, = 100 + 0.00223 X 100 (90 — 75)
= 100 + 0.223 X 15
= 103.345 per 1000 ft. or 0.103345 ohms per ft.
Connecting Ground Circuit of Generator — At what point
in the armature of a three-phase generator would it be proper
to connect the ground circuit for the generator to operate on
a grounded neutral system?
A. R. P.
If the generator is star connected, ground the neutral as
in Fig. 1, in which case the maximum potential to ground
will be 5S per cent, of the line voltage. If delta-connected.
Pig. 1 Pis. 2
Methodb of Gbotjnding Generator
one side may be grounded as in Fig. 2, in which case the
maximum potential to ground is S7 per cent, of the line volt-
age. The ground may be direct, or through resistance 01
reactance, the latter limiting the flow of current.
[Correspondents sending us inquiries should sign thetr
communications with full names and post office add losses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.}
January 19, 1915
POW E 1;
103
jpiillillliiiiiiiiiiiiin mi iiiiiiii in ii. iiiiiiiiiiiiiLiuiiiii iiiiiiiiimiiiiin :;, iiiiiiiniiiiiini in .:iijiiiiiiiii iiiiiiiiiiiiiiiniiiiiiiiiiiiiiuiuiii mi imiiiiii iiiiiiiiiui' iiiiiiiiiiiiiiiiiiiiiiuiiiiiiii
lEinigliinieers9 Stadly Course
inmi iiiiiiii iiniiiiiiiiiiiuiiiiiiiiiiiiiiuiiiiiiiiiiiiiiioiiiiiiiiiiiniiii iiiimiiii iniiiiiiiiiiiin iiiiiiiiiiiiiiiiiininiiiiiiii nun mini uiiciiiiiiuuiiuuutMiuiiuiiluiiiHi nu iram iiimiiiiiiiiiii mi iiiiiiuiiiiiiinii imiiiiii nun iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiin iiiiins?
Electric battery, particularly
All the activities of power plants depend upon the gen-
eral fact or law of nature that tin.' different kinds of energy
can be converted one into another. In these activities
four kinds of energy are involved: Chemical, thermal,
mechanieal and electrical. Selection by twos gives the
following combinations, as illustrated by one or more
practical examples :
Chemical energy to heat: Combustion in boiler fur-
nace or in engine cylinder (a).
Chemical to mechanical: No direel conversion, heat
energy coming between.
Chemical to electrical :
the storage battery (b).
Heat to chemical energy: Dissociation of water or car-
bon dioxide in boiler furnace or gas producer, also op-
erations of reducing metals from their ores (b) or (c).
Heat to mechanical work: All kinds of heat en-
gines (e).
Heat to electricity: Only such feeble activity as that
of the thermocouple.
Mechanical work to chemical energy: None.
Mechanical to heat: Compression, friction, impact,
etc. (a).
Mechanical to electrical : The electric generator (b).
Electrical to chemical : Electrolysis, as in charging
storage batteries (b).
Electrical to heat: Electric lighting and heating; use
of a rheostat as load for a generator, when testing (a).
Electrical to mechanical: The electric motor (b).
Three of these combinations, namely, chemical to me-
chanical, mechanical to chemical, heat to electrical, are
either absolutely or practically impossible except through
some intermediate transformation. The other nine are
divided into three classes, indicated by the letters (a),
(b), (c).
Class (a) comprises the transformations which are or
L-an be complete, every one having heat as its final state.
The fact that the whole of the fuel may not be burned in
i furnace or engine does not qualify the completeness o(
mergy conversion for what is burned, and under special
:onditions, as in the fuel calorimeter, complete combustion
is surely obtained. In the conversion of other forms of
■nergy into heat an efficiency of unity is, therefore, attain-
ible.
The transformations in class (bj have unit efficiency
is an ideal limit, which may be approached but never
juite attained. To these interchanges between chemical
ind electrical and between mechanical and electrical ener-
gies should he added the transmission of mechanical
cork and its change in form by machinery. The efficiency
>f most machines lies within the range of from 70 to 95
>er cent. A large generator or motor will go a little above
>5 per cent. The perfect generator, motor or storage bat-
ery cannot be realized, but it is easily imaginable and
an be quite closely approximated.
Notice particularly that all the energy not usefully
converted in the operations "I' class (b) is changed into
heat and thus wasted.
Last cornea class (c) — the conversion of heat into sunn-
other form of energy, and especially into mechanical
work; in other words, the question of heat-engine opera-
tion and efficiency. The outstanding fact in this field
is the impossibility of anything approaching complete
conversion. Within the limits imposed by natural physi-
cal conditions, there is no known or imaginable method
or scheme of working by which a heat engine can change
into work the whole of a given amount of heat supplied
to it. Necessarily, such an engine converts but a portion
of the heat received and gives up the remainder as heat in
an inconvertible state. Its limit of efficiency is not 100
per cent., but some fraction which, with varying condi-
tion.-, ranges from perhaps 15 to G5 per cent. To reason
out the character of this limit and establish its value is
one of the important tasks of the science of thermody-
namics.
After the descriptive statements which have just been
made, and keeping in mind the power-plant point of view,
the following summary will appear rational:
Chemical, mechanical and electrical energies may be
put in one class, and are sometimes called the higher
energies. Heat is a class by itself and is a lower form of
energy, especially when it has sunk into a state of low
temperature or intensity.
Then the different types of conversion classified as
(a), (b) and (c) may be briefly defined as follow-:
The higher energies can be completely converted into
heat. They also have certain interconvertibilities, in
which the efficiency may approach, but can never attain
to. unit value. And what is not usefully converted is lost
as heat.
By certain processes heat can be converted into the
higher energies, but only in part, since there is alwavs a
large remainder of energy left in thermal form.
Finally, the tendency in nature is for all kinds of
energy to sink into the form of heat of low temperature.
Relative Efficiency of Steam, Gas and Oil Engines — ■
Roughly stated, a first-class modern steam engine utilizes
about 12 per cent, of the available heat in the coal, resulting
in, say 1.6 to 1.7 lb. of fuel per b.hp.hr. during a week's
work of 55 hr. If the boilers are to be fired by producer gas,
for which purpose slack and dust can be used, then each
brake horsepower will require about 2 to 2.2 lb. of coal.
Internally fired gas and oil engines are approximately twice
as efficient as steam engines, which means that they utilize
about 25 per cent, of the available heat. Crude oil being
per cent, better than good ordinary ccai, oil engines should
use only about three-eights as much oil as the coal men-
tioned above, say about 0.6 lb. per b.hp.-hr. Then, however,
as there are no boiler radiation losses over night, a material
saving results and the oil consumption per week of 55 hr.
may be about 0.5 lb. per b.hp.-hr. Petrol and similar internal
combustion engines would require about 0.4 ib. per b.hp.-hr.
Gas engines have also about the same efficiency as oil en-
gines; but as there is a loss of about 20 per cent, in the pro-
ducers, if these work day and night, and another loss of quite
10 per cent, if they have to stand idle over night, the effi-
ciency of gas engines is only about 40 per cent, better than
that of first-class steam engines.
104
POWER
Vol. 41. No. 3
•esig'mi amicS Operation of tlhe Cleve-
dirndl Mtunmicipal Electric ILiglutt Plsunitf
By Frederick W. Ballaud
The new Cleveland. Ohio, municipal lighting plant, known
as the East 53d Street Station, went into operation July 20,
1914. It is the largest central station in this country built by
a municipality, and is intended not only to supply electric
current for street and commercial lighting, but also for
power users. The rates charged for the service range from
$0.03 per kw.-hr. maximum to $0.01 per kw.-hr. minimum.
This station has a capacity of 25,000 kw. and is at present
loaded to one-fifth of its capacity.
The estimated results which will be secured from the new
25,000-kw. station, which has just been placed in operation,
are based upon an annual output of 60,000,000 kw-hr. and with
fixed charges founded upon a total plant investment of
$3,000,000. Fixed charges amounting to 9 per cent, on this
investment would equal $0.0045 per kw.-hr. Cost for coal is
estimated at $0,002 per kw.-hr.; station costs exclusive of
coal at $0.0015; distribution costs exclusive of fixed charges
at $0,004; administration charges at $0,005, and profits at S
per cent, on the investment at $0,004. This makes an average
price to be secured per kilowatt-hour generated of $0.0165.
From the three months' operation of this station, together
with tests that have been conducted, the indications are that
these estimated results will be secured.
The plant was built from the proceeds of a $2,000,000 bond
issue by the City of Cleveland, about one-half of this amount
being invested in the station itself. The other half is to be
invested in the substations and in the distribution system,
including overhead and underground lines. In addition to
the $2,000,000 derived from this bond issue, there are also
available the proceeds of a $500,000 bond issue voted by the
City Council to supplement the original bond issue, making
a total amount of $1,500,000 to be invested in the distribution
system. The value of the present distribution systems con-
nected with the Brooklyn and the Collinwood stations is about
$500,000, making the total value of the East 53d Street Station,
together with its distribution system, about $3,000,000.
The results which have already been obtained in the
operation of the Brooklyn lighting station and the East 53d
Street Station during the first eight months of the year 1914
tend to substantiate the original estimates of what will
eventually be secured in connection with the operation of the
East 53d Street Station. A statement of revenue and expense
connected with the operation of these two stations for the
first eight months of the year is as follows:
TABLE 1-REVENTE AND EXPENSE STATEMENT FOR
FIRST EIGHT MONTHS, 1914
Revenue from sale of current for first eight months
of 1914 $153,363.65
Kw.-hr. generated, 7.S6<1,610; average sale price,
SO. 0195.
Kw.-hr. sold. 6,270,726; average sale price,
$0.0244.
Operating and maintenance for first eight months 9 ■,044.60
Kw.-hr. generated, 7,S63,610; average cost price,
$0.0123.
Kw -hr. sold, 6,270,726; average cost price.
$0.0154.
Net earnings for eight months $56,319.05
The total kilowatt-hours generated for eight months is
greater than the output for the year 1913. The average cost
price per kilowatt-hour generated is $0.0123, as compared
with $0.0149 for the previous year. The results secured in
the way of operation and maintenance costs in the power
station itself for the months of August and September are
shown in Table 2:
TABLE 2 — EAST 53D STREET POWER STATION REPORT,
AUGUST AND SEPTEMBER, 1914
Aug. Unit Cost Sept. Unit Cost
Operation-
Labor
Switchboard attendance.. 352.80
Oil. packing and waste.. ....
Sundry expense ....
Coal 2686.50
.Maintenance —
Condensers, piping, etc... 5.48
$1573.00 - I i
3S0.00 0.00042
2415.69 0.0026
Total operation and
maintenance $4543.26
Total kw.-hr. generated 809,120
•Excerpts from paper read at the annual meeting, Decem-
ber, 1914, in New York City, of the American Society of
mica! Engineers.
The East 53d Street Station during these two months has
been operating at less than one-fifth of its total capacity.
The figures representing unit costs for the various items of
labor, maintenance, fuel, etc., are considerably higher than
should obtain when the station is running up to its capacity,
when it will be operating at a much higher efficiency in
regard to coal consumption per kilowatt-hour, and also the
labor and other charges will be less per unit cost by reason
of the larger output. During the month of August, the out-
put of the Brooklyn and East 53d Street Stations amounted
to 1,117,920 kw.-hr., of which 936,467 kw.-hr. was sold to
customers, giving a loss in transmission of only 16 Vi per cent.
The average sale price for the kilowatt-hour generated was
$0.0174, while the average sale price of what was sold was
$0.0207, the revenue for th.e month being $19,405.38.
That an average load factor of 40 per cent, will be secured
on this station when the load is built up to its ultimate ca-
pacity seems to be assured, and the indications are that a
better load factor will be obtained. A typical load curve is
only 2700 kw., but with a load factor of SO per cent, based on
the peak load there is a total output on the generating sta-
tion of 51,925 kw.-hr. If these conditions can be maintained
or even approximated when the load on the station has been
built up to its ultimate capacity, the load factor "will be con-
siderably greater than 40 per cent. The location of the
station was determined mainly by the convenient and eco-
nomical facilities for delivering coal and also by the possi-
bility of securing the cheapest and best water for condensing
purposes. The Water-Works Department has a 9-ft. tunnel
extending five miles into Lake Erie and draws water at this
point from 125 ft. below the surface. This water, after pass-
ing through the surface condensers in the power plant, passes
on to the suction chambers of the water-works pumping en-
gines. The increase in temperature of the "water going into
the city mains, it is estimated, will not exceed 1 deg. F. In
this way the lighting plant has not only secured the cleanest
and coldest water for condensing purposes possible, but has
also made use of a plant calculated to obviate any possi-
bility of interruption by clogging of the inlet with ice or
debris floating in the lake.
The coal question was considered as of next if not of
equal importance to that of water. As the Lake Shore &
Michigan Southern Ry. tracks run along the southern line
of the property, with an elevation of about 60 ft. above the
lake level, a method of handling the coal almost entirely by
gravity has been worked out. Fig. 1 is a cross-section of
the station in detail, wherein the coal is delivered overhead
by the railway cars and is discharged by gravity into 3400-
ton capacity bunkers, from which it is drawn through gates
under pneumatic control into an electric telpher, which
moves back and forth from under the bunkers on the track
leading out over the stoker hoppers. The coal hopper on
this telpher is carried on scale beams, and the weight of the
coal and the time of delivery are recorded.
The special features in connection with the design of this
station different from standard practice are as follows; The
use of motor-driven auxiliaries throughout the plant; large
boiler units with high steam pressure; economizers of greater
capacity than ordinarily installed; a new arrangement of
coal-handling apparatus; the use of both forced and induced
draft with practically atmospheric pressure in the combus-
tion chamber; automatic control of furnace conditions: sim-
plicity of the piping layout, due to motor-driven auxiliaries;
and the use of an auxiliary steam turbine for driving the
auxiliary motors. This turbine is supplied with a jet con-
denser, the cooling water for which is used as boiler feed
water after being passed through the economizers.
The practice of using motor-driven auxiliaries has not
been adopted in this country principally for two reasons —
(a) the use of exhaust steam from the steam-driven aux-
iliaries for feed-water heaters has been considered advisable
as giving sufficient economy to warrant the use of steam,
rather than motor-driven auxiliaries, and (b) the operation
of the auxiliary equipment in the station by current from the
main generators has been considered to introduce an ele-
ment of uncertainty and unreliability into the service which
it would be better to avoid.
To the first objection it can be stated that the thermal
efficiency of the station can be shown to be lusher when the
January 19, 1915
row e R
105
auxiliaries are motor driven and the
heat for the boiler feed water is secured
by the use of economizers from the flue
gases. No arrangement of steam-driven
auxiliaries would give just the proper
amount of exhaust steam for heating the
feed water properly at all loads on the
station. There would always be periods
when there would be either not enough
or too much steam, and some would go
to waste. There is also the complexity
of steam piping necessary for supplying
the auxiliary engines, with the incident
losses from radiation and leakage. The
second objection is answered by the in-
stallation of an auxiliary steam turbine.
A 1000-kw. turbine with an overload ca-
pacity of 1500 kw. has been in operation
in the Brooklyn Station for years and is
now in good condition. This machine
will be removed to the new station.
This machine will be operated in con-
nection with a jet condenser, the cooling
water for which will be drawn from a
cistern which is used for the storage of
the boiler feed water for the station.
This cistern is divided into two compart-
ments by a wall, the top of "which is
about two feet below the surface of the
water. On one side of this wall will be
the cold well and on the other side the
hotwell. The condensate from the three
main turbines will be discharged into
the cold well and carried to a point near
the bottom, where is located the suc-
tion end of a pipe carrying the circulat-
ing water to the jet condenser. The dis-
charge from the jet condenser will be
carried to the other side of the cistern,
or the hotwell, and delivered at a point
near the suction end of the pipe carry-
ing feed water to the boilers. The make-
up water for the system will be deliv-
ered into the cold well at the same point
as the discharge of the condensate from
the main turbines. The makeup water
will be under control of a float valve de-
signed to maintain the level of the water
in the cistern at the required height.
It is not the intention that the uan-
tity of water flowing through t' feed
piping system to the boilers shall deter-
mine the volume passing through the jet
condenser as the volume of circulating
water will be several times greater than
the quantity of feed required by the
boilers. The water in the cistern will,
therefore, pass through the jet condenser
several times before it goes as feed
water to the boilers, and to prevent a
uniform temperature throughout the
cistern and a consequent lower vacuum
in the jet condenser, the arrangement of
hotwell and cold well was provided, and
the piping was connected in such a man-
ner as would supply the coldest water to
the condenser and the hottest water to
the boiler-feed system.
The auxiliary motors in the station
will all be connected through a double
bus system, so that each motor can be
- pi rated either by current from the
auxiliary turbine or from the main gen-
erator. In this way the load on the
auxiliary turbine can be adjusted so
that the temperature of the feed water
will be that best suited for delivery to
the economizers. This temperature
should be approximately 120 deg. P. If
much less than this amount, the econ-
omizer tubes will scab- with soot and
cause trouble. If a greater temperature
than that necessary to avoid this trouble
is secured, there will be a sacrifice of
economizer efficiency. Fig. 2 is a floor
plan of the plant.
The use of large boiler units with high
cteam pressure was decided upon. The
boilers ultimately installed were similar
106
P 0 W E K
Vol. 41, No. 3
to those in the Delray Station in Detroit, and the dimensions
are identical, except as to the length of the drums. These
boilers (Fig. 3) each have 10,000 sq.ft. of heating surface and
are designed to carry 275-lb. working pressure with a super-
heat ranging from 125 to 150 deg. F. They are equipped with
underfeed stokers and are intended to be capable of operating
up to 300 per cent, of rating.
The operation of the boilers at a high percentage of rating
means a higher temperature of flue gases. This, with the
low temperature of feed water, gives a temperature head
between flue gases and feed water which will be practically
it was thought that a conservative estimate on economizer
requirements would be 27,000 sq.ft. of heating surface. They
are arranged in two parallel sections, independently, so that
either section can be cut out by means of dampers for clean-
ing and repairing, leaving the other in operation.
The use of both forced and induced draft contributes to
the flexibility of the installation and makes it possible to
carry practically a balanced pressure in the combustion cham-
ber, thus avoiding one of the greatest sources of loss in
boiler practice, the leakage of air through the boiler set-
tings. Two induced draft fans were put in, either of which
Fig. 2. Floor Plan of the Cleveland Municipal Lighting Plant
double that ordinarily obtained in economizer practice. This
alone would be sufficient to warrant a larger amount of
economizer heating surface than would ordinarily be deemed
advisable. However, there is another factor in the Cleveland
situation which also warrants an increase in the economizer
capacity. In economizer practice, the interest on the invest-
ment, generally figured at 6 per cent., is balanced against
the saving which will be produced in the economizers, but
in municipal engineering it is found that interest on the in-
vestment can be figured at 4% per cent, instead of at 6 per
cent. This fact alone would warrant an increased capacity
in the economizer. Taking these factors into consideration,
has a capacity for taking care of the peak load requirements
of the station. A separate forced-draft fan with an individual
motor drive was placed in the boiler room basement for each
furnace. The motors on the forced-draft fans are under
automatic control, and their speed is governed by means of
rheostats controlled by the boiler pressure. The motors for
operating the stoker feed are also controlled by rheostats
governed from the pressure in the air ducts underneath the
boilers. The induced-draft fans are under manual control, and
their speed is intended to be regulated by the man operating
the boilers so as to give the proper draft for holding prac-
tically an atmospheric pressure in the furnaces.
January 19, 1915
POWER
m
The steam piping is simple, because, outside of the aux-
iliary turbine and the emergency equipment consisting of a
steam-turbine exciter and a turbine-driven feed pump, steam
will be used only in the main generators. The plant is so
arranged that each battery of two boilers is opposite one
turbine generator, the steam lines from the boiler going to
the header, from which a short branch is taken to the tur-
bine. The header is capable of being cut into three sections
by means of Hopkinson-Ferranti valves, with operative work-
ing parts of half the diameter of the steam main. The in-
terior of these valves is shaped like a Venturi nozzle; they
will pass an amount of steam equal to the full carrying
capacity of the pipe with practically no reduction in pressure.
The main steam header is located in the boiler-room base-
ment near the floor, and the piping is arranged so as to drain
to this header from all directions. This header is 135 ft.
cording instruments for practically every operation in the
station. There is a graphic recording totalizing watt-meter
which gives a continuous record of the combined output of
the station. The amount of feed water going to the boilers
is shown by the indicating dial of a V-notch recorder, which
also gives a continuous graphic record and the total quantity
by means of integrating dials. The C02 in the flue gases is
recorded, and recording thermometers keep record of the
temperature of the feed water entering and leaving the econ-
omizer and the temperature of the flue gases in the boiler
breechings as well as at the discharge end of the economizer.
The steam pressure and the temperature of the steam in the
main header are also recorded, thus giving a record of the
superheat. This information, together with the record of
the weight of coal going to each boiler, which, is turned in
to the chief engineer at the end of each S-hr. shift, enables
him to have a complete log of the per-
formance of the station made up every
day.
The use of 11,000 volts removes the
necessity of having rotary converters, the
absence of which is particularly notable
when compared with the prevailing prac-
tice of supplying the congested districts
of large cities from numerous substations
in which there are placed rotary con-
verters for changing alternating into di-
rect current.
Fig. 3. Section through One of the Boilers Having 10,000 Sq.Ft
of Heating Stjeface
long and designed for the minimum of expansion which would
effect a lateral movement in the branch pipes. It is divided
in the middle by an expansion bend, which consists of two
short headers carrying four small U-shaped pipes of only
one-half the diameter of the main. Two halves of the main
header are then anchored securely at their central points and
carried on rollers from this point in both directions. This
then divides the main header in such a way that at no place
would the movement caused by expansion be more than that
due to the expansion in one-fourth of its length. The main
steam header is only 14 in. in diameter and is composed of
%-in. thick steel pipe with welded necks and flanges. The
branch pipes contain no fittings except the valves, which are
of heavy cast steel. All turns are of long bends and all
sections have welded flanges.
The feed-water pumps are all centrifugal. Two are con-
stant speed and motor driven. One is steam-turbine driven
and is designed for emergency purposes and for operation
when no electric current is available. This pump is arranged
writh governor control for constant pressure and is therefore
capable of being used in connection with either of the motor-
driven pumps and to supply water to the boilers only when
the demands are in excess of the capacity of the other pump.
In the chief engineer's office are located indicating and re-
DISCUSSION FOLLOWING THE PRESEN-
TATION' OF MR. BALLARD'S PAPER
Robert L. Brunet, of Providence, R. I.,
in a written discussion, said that with low
rates for energy the load factor of 40 per
cent, would possibly be realized based on
a peak of IS, 000 kw., but when the peak
of IS, 000 kw. is reached the generating
equipment will undoubtedly have to be
increased to insure reliability and con-
tinuity of service. He has found that the
income per $1 of investment varies from
20 per cent, to 25 per cent, in most pri-
vate plants, while Mr. Ballard has esti-
mated an income of 33 per cent, per $1
of the investment.
James R. Cravath, of Chicago, said that
it would have to be demonstrated whether
the estimated maximum load of IS, 000
kw. could be brought to the Cleveland
station with a distribution cost low
enough to bring the total investment in
K D gj power-plant and distribution systems to
but $3,000,000. It is possible by cultivat-
ing the large motor-service business and
ignoring the low-load-factor lighting bus-
iness, such as residences and early-clos-
ing stores, that a 40 per cent, load factor
might be maintained from the start. The
natural tendency of rates as low as those
given would be to load up the plant with
low-load-factor business unless care was
exercised to prevent it.
Alex Dow, president of the Detroit
Edison Co., said that he had followed the
construction and operation of the plant with interest; that
the plant was a good one, a credit to Mr. Ballard, to the con-
sulting engineer and to the city officers who let them go
ahead and make a good plant. He said that what Mr. Ballard
needed first was a distributing system, which he has not, and,
second, a load, which he has not, n7id, third, the keeping of
accounts in a manner acceptable to a public service commis-
sion. Mr. Dow was of the opinion that there was nothing
radical in the station, inasmuch as it contained apparatus
practically the same as that in the Delray Station.
Reginald Pelham Bolton, of New York, said that the rates
are such as to offer little inducement to those consumers
whose business is most desirable in producing a high load
factor and that this rate does not include any service charge
and is drawn merely on the relation of connected capacity
and monthly consumption. He wanted to know if there wTere
any data' in the paper which justified the expectation that
the small consumer can be served at the rate of 3c. per
kw.-hr. without loss, which must be borne by other con-
sumers or by a deficit in operation.
Mr. Ballard, in his response, said that he was delighted
to learn that Mr. Dow did not consider that there was any-
thing at all radical in the Cleveland station. He admitted
it was true that everything in the station is the same as at
108
P 0 AY E Pv
V..1. H. X.i.
the Delray plant, and inasmuch as this is so there was no
reason why the Delray Station should not sell its current at
the same price at which the Cleveland plant was selling it;
and he hoped to see them do it. Regarding station rating,
Mr. Ballard's understanding was that stations at the present
time are generally rated at their maximum capacity for a
24-hr. service indefinitely. Tests show that the turbines in
the Cleveland plant are capable of 7500-kw. continuous ca-
pacity, three giving 22,500 kw. and the 1500-kw. auxiliary
machine bringing the total maximum capacity to 24,000 kw.
Upon these figures his statements were based. In regard
to capacity, in answer to Mr. Cravath's discussion of the
40 per cent, load factor, Mr. Ballard said: "I find it is not
difficult for us to get a 40 per cent, load factor — to get it
and to average it. We are running along every day between
60 and SO per cent, load factor. As we build up the load on
our stations we will probably secure a much lower power
factor than that. We may go down to 40 per cent., but I
hope we will not go below that."
Regarding the cost per kilowatt-hour being different for
different customers, Mr. Ballard admitted that the plant was
radical in that respect, saying: "Outside the question of com-
petition, if there was only one station in the city and every
customer had to take its terms or have none at all, you
could not make one figure and a uniform load. Tou could
not sell current to all your small resident customers at as
low a rate as you would want to sell it to your power cus-
tomers. On the other hand, you could not charge your power
customers at a higher rate than your resident customers.
If you did you could not get the business. That is not neces-
sarily following out the plan of the National Electric Light
Association of charging all that the service will bear. If
you can sell current to large power companies at lc. you
are selling to the majority of them for less than one-half of
what they can make it themselves."
85
Aus&©tnmsi&iie Reclosairag' C£s°euaii{t~
BY E. C. RAHBI
In the application of protective apparatus to the power cir-
cuits of industrial plants there are four conditions which
should be fulfilled:
1. The current must be quickly interrupted in ease of
short-circuit or excessive overload.
2. The circuit should not be closed while the short-cir-
cuit still exists.
3. To avoid unnecessary delay the circuit should be closed
instantly upon the removal of the short-circuit.
4. For the protection of motors on the circuit, power
should not be restored until the controllers or starting-box
levers have been moved to the "starting position."
The first of the above conditions may be met by placing
either a fuse or a hand-operated circuit-breaker in the cir-
cuit to be protected. It will be readily seen, however, that
the remaining conditions are difficult to meet by either the
hand-operated breaker or the fuse, in cases where the line is
of considerable length and the load is not in sight of the
attendant.
These difficulties were forcibly brought to the writer's
attention while in charge of power plants for mine work and
while a motor inspector in steel mills. At that time there
was no protective device on the market which met all four
conditions, and it was the necessity for such a device which
led the writer into the work of its development. The auto-
matic reclosing circuit-breaker, here described, is the result of
these efforts up to the present time.
THEORY
In order to make a circuit-breaker which will automat-
ically reset after the overload condition has been removed,
it is required that a shunt circuit with a resistance be pro-
vided around the main contacts, so that after the main con-
tacts are open there may still be a small amount of current
to act as an index to the condition of the line. The reclos-
ing mechanism must be responsive to variation in this index
current, which variation must be caused by the increase of
resistance of the load or short-circuit. For example, take
the case of the circuit-breaker on a 250-voit circuit, set at
500 amp. When the load resistance becomes such that more
than 500 amp. will flow, this resistance will be
E 250 „ . .
R=r = 500= 0.5 ohm or le*.
In case of a short-circuit the resistance of the load be-
comes practically zero and the breaker must be so constructed
•From a paper read before the Ohio Society of Mechanical,
Electrical and Steam Engineers.
that it will not reclose while the load resistance is less than
0.5 ohm. Since in practical circuits it is always permissible
to have lights or a constant load connected to circuit, the
breaker should be capable of reclosing whenever the load
resistance has reached a value slightly above that which
caused the breaker to open. Assume that the constant load is
250 amp. and the motor load 250 amp. in the foregoing ex-
ample. The load resistance will then never be greater than
1 ohm, which will require that the breaker shall not close
on a load resistance of less than 0.5 ohm, but will reclose be-
fore the resistance has been increased to 1 ohm. In other
words, the reclosing mechanism must be sensitive enough to
respond to a change of resistance of less than 0.5 ohm in the
load circuit.
The resistance of the shunt circuit around the breaker
must be 125 ohms, if 2 amp. is allowed to flow at 250 volts on
short-circuit as an index current. In commercial circuits the
voltage variation is likely to be 10 per cent, or more, which
means that the current variation through the 125-ohm shunt
may be 10 per cent, of 2, or 0.2 amp. due to that cause alone.
The variation of current in the shunt circuit resistance,
caused by the load resistance being increased from 0 to 1
ohm, will be
250
2 - -,= = 0.090 amp.
12b
which is less than the variation due to permissible voltage
variation.
It was this consideration which led to the adoption of the
shunt circuit used in the present breaker, where two paths
are provided for the current after passing through the load.
In a branch circuit carrying a definite amount of current.
Opemting coil fo
hold breaker ■-..
closed
Trip coil to close circuit of
operating coil when over-
load is removed
Series coil, opens circuit
' of operating coil on
overload
""""Y Resistance Tubes
Generator-
ED
Diagram Illustrating Operation of Circuit-
Breaker
the latter divides in the two branches inversely proportional
to their respective resistances. When the load resistance is
practically zero, on account of a short-circuit, nearly all the
current flowing through the shunt resistance passes through
the load circuit; but when the short-circuit is removed and
the load resistance is increased to 1 ohm, if the load resist-
ance coil has 1 ohm, then the current will be equally di-
vided in the two branches and the current variation in the coil
will be from 0 to 1 amp., which may be made enough to
operate a relay setting the reclosing mechanism into oper-
ation.
OPERATION
Referring to the. diagram. Fig. 1, it will be seen that the
main contact brush is moved to the closed position and is
held closed by the operating coil. The main load current
passes through a series coil and main contacts. In case of
an overload current in the series coil, its armature or core is
raised and opens a contact which breaks the circuit of the
operating magnet and allows the breaker to open.
The contact arm controlling the current in the operating
coil is now held open by a latch until the trip coil operates to
release the latch. After the opening of the main contact a
small current is permitted to flow around the breaker through
a high resistance. This current has two paths leading to the
line of opposite polarity, one path around the breaker and
through the load, and the other through the trip coil and
the dashpot bridge. So long as there is a short-circuit or
low resistance on the load circuit, this index current will be
shunted past the trip coil, but whenever the short-circuit is
removed or the load resistance is increased to a certain
amount, enough current will be forced through the trip coil
to operate the latch and allow the contact arm to again
close the circuit of the operating coil. The breaker is then
instantly closed by this action.
A dashpot is provided to prevent the breaker from clos-
ing instantly after being opened by a momentary overload.
The object of this is to give sufficient time for motors to come
to rest and for starting-box levers to be moved to starting
position before the breaker recloses. regardless of the cause
of the open Ing.
Briefly stated, the action is as follows: The breaker opens
in case of either an overload or short-circuit, and remains
January 19, 1915
POWER
109
open a few seconds in either case. At the expiration of this
time limit, it closes, provided the overload condition has been
removed; it remains open so long- as a short-circuit exists
rnd closes instantly upon its removal.
Digested by A. L. H. STREET
Electric Power as a "Municipal Purpose" — Provision in an
electric power company's franchise granted by a city requir-
ing the company to furnish power to the city for "municipal
purposes," on certain terms, extends to the furnishing of cur-
rent to operate an electric-light plant. (Colorado Supreme
Court, City of Colorado Springs vs. Pike's Peak Hydro-Elec-
tric Co., 140 "Pacific Reporter," 921.)
Assumption of Risk by Engineer — An engineer in a sta-
tionary plant assumes the risk of fallin™ into a pit after
another employee has left the trapdoor covering it open,
where he knows that it is apt to be open any time, according
to the holding of the Massachusetts Supreme Judicial Court
in the late case of Burnett vs. "Worcester Brewing Corpora-
tion, 106 "Northeastern Reporter," 597.
Validity of Condemnation Statute — In a proceeding by an
electric power company to condemn land for use of the
company, under the laws of Tennessee, which restrict the
right of condemnation to corporations, the landowner cannot
question the validity of such laws on the ground that they
constitute an unjust discrimination against individuals and
partnerships who are not accorded the right of condemnation,
since he is not injuriously affected by any such discrimination
that may exist. (Tennessee Supreme Court, Noell vs. Ten-
nessee Eastern Power Co., 169 "Southwestern Reporter," 1169.)
Right of Power Company to Condemn Land — In a decision
announced by the Minnesota Supreme Court, the Minnesota
Canal & Power Co. is denied the right to condemn land for
one of its projects, on the ground that the enterprise could
not be accomplished without impairing the navigability of the
waters of the Birch Lake drainage basin. The court holds
that a power company, or other public service corporation,
cannot divert water from the navigable streams of one drain-
age basin into those of another basin, if the diversion impairs
the navigability of the former; and that private property
can be condemned only when the condemnation subserves
some lawful public use.
Extent of "Water Power" Rights "Horsepower" Judicially
Defined — When the right is granted to use the water of a
canal or stream for the development of "water power," the
grantee acquires no right to use the water for any purpose
other than the propulsion of machinery; no water may be
diverted or consumed for condensation purposes. This point
was recently decided by the Pennsylvania Supreme Court in
the case of the Eastern Pennsylvania Power Co. vs. Lehigh
Coal & Navigation Co., 92 "Atlantic Reporter," 47. Referring
to the term "horsepower," the court finds that it "has in
popular acceptation a fixed, definite meaning. As originally
employed it expressed the power of a steam engine. It has
come to mean the unit in estimating the power required to
drive machinery."
What Constitutes a "Stationary Steam Engine?" — Is a
steam engine, which has been set upon a concrete foundation
and so bolted and braced as to be free from vibration and
which is used in quarrying rock and may be so used for two
or three years, a stationary engine within the meaning of an
ordinance prohibiting operation of stationary steam engines
within certain limits in a city without first obtaining a li-
cense? This question, which was recently presented to the
Massachusetts Supreme Judicial Court in the case of McDon-
ough vs. Almy, 105 "Northeastern Reporter" 1012, was
answered by that court in the affirmative. Justice Crosby said,
in announcing the decision: "Whatever may have been the
character of the engine when it was brought to the plaintiff's
land, we have no doubt that when it was set upon the con-
crete foundation and permanently attached thereto for the
purpose of being used two or three years, it became a 'sta-
tionary steam engine' within the meaning of the ordinance."
Remedy for Breach of Contract — According to the decision
of the West Virginia Supreme Court of Appeals in the case
of United Fuel Gas Co. vs. West Virginia Paving & Pressed
Brick Co., 82 "Southeastern Reporter," 329, suit will not lie
to enjoin a manufacturer from breaking a contract to buy
fuel from plaintiff exclusively for a certain period. The court
holds that the fuel company's only remedy is a suit to re-
cover damages for breach of the contract. The defendant
agreed to purchase from the plaintiff, for a period of three
years, all the natural gas it should use in its manufacturing
plant, and to pay for the same monthly at certain prices
per thousand feet, graduated according to the quantity used.
About the middle of the term the defendant purchased natural
gas from another gas company and ceased using the plaintiff's
product, whereupon the plaintiff applied for an injunction to
restrain the defendant from purchasing gas from the other
company during the term of the contract.
Effect of Power Rnte Ordinance on Existing Contracts —
When a consumer of electrical power makes a contract with a
public service corporation for service, the parties are con-
clusively presumed <o have contracted in contemplation of
the power of the proper public authorities to fix rates, ac-
cording to a decision handed down the other day by the Su-
preme Court of California in the case of Pinney & Boyle vs.
Los Angeles Gas & Electric Corporation, 141 "Pacific Re-
porter," 620. The effect of this decision is to nullify the con-
tract rate on a higher or lower rate being established by pub-
lic authority. Plaintiff used electrical power to operate its
machinery, and made a contract with defendant for future
service. During the life of the contract, the city of Los
Angeles adopted an ordinance fixing a schedule of rates which
was higher for the service involved than that fixed by the
contract, and the defendant declined to furnish service at the
contract rate. The decision of the Supreme Court upholds the
defendant's position and overrules the plaintiff's contention
that the ordinance is invalid.
Power of Traction Engines — When a contract for the sale
of a traction engine contains a warranty on the part of the
seller that the engine will develop a certain horsepower, but
does not specify whether the power is to be developed at the
belt or at the drawbar, the transaction will be governed by
a trade custom placing an interpretation on the point, accord-
ing to a late decision of the Texas Court of Civil Appeals in
the case of Southern Gas & Gasoline Engine Co. vs. Adams
& Peters, 169 "Southwestern Reporter," 1143. Under the evi-
dence in this case, such a contract is held to be properly
interpreted under a trade custom requiring the rated horse-
power to be developed at the drawbar. Referring to the rule
of law that the provisions of a written contract cannot lie
varied by showing oral conversations or trade customs which
are clearly inconsistent with such provisions, the court said:
It is not varying the terms of a written instrument to
explain what is meant by a term used therein, especially a
scit-ntific or trade term which is not generally understood.
Here we have the written instrument merely stating that the
engine is to develop 20 hp. It is nowhere stated that
it is to develop that power at the belt or drawbar, and
the only way a layman could understand the term would be
by proof as to what is meant by such a term. If it had stated
that the power should be tested at the drawbar or belt, there
could be no question that oral evidence could not be introduced
which would tend to vary the writing. But parol evidence
is admissible to aid in the interpretation of a scientific or trade
term.
■+•
.AjraottlhieiP Feedlcst? Accadloimft ana
Clevelasael
The municipal lighting plant at Cleveland celebrated the
end of the year by a short-circuit in an overhead feeder lead-
ing out of the West 41st St. substation, which is the distri-
bution center for the part of the city bounded by Lake Erie,
West 65th St., Brooklyn and west of the Cuyahoga River. The
trouble started about 8 p.m. on Dec. 31, and service was not
restored till after midnight. It is stated that the cause of
the trouble was a short-circuit in changing over feeders to
consumers who formerly were served from the South Brook-
lyn plant to the new plant on East 53d St. In the area within
which service was cut off, several hospitals reverted to oil
lamps or gas, street lights were out and a number of mov-
ing-picture shows had to suspend operations.
IL©eh§| §©tmtl]h©ff,na EJcecthfi© Tafias"
tnmass£©irs
The Tennessee Power Co.'s Sequatchie Valley transmission
line was completed about the middle of last December. Elec-
tric current was then turned on from the $10,000,000 power
plant at Hale's Bar (of which the Tennessee Power Co. is
now the largest customer) to both of the three-phase con-
ductor circuits.
Although the generators have been connected to the trans-
mission line since last August, only one of the three-phase
circuits had been in full working order until mid-December.
The transmission line is one of the most permanently con-
structed in the South and the longest line of the kind, volt-
age capacity considered, in that part of the United States.
College, the village at which the Brady power plant is
connected with the Ocoee-Nashville line, is about 36 miles
110
POWER
Vol. 41, No. 3
from Hale's Bar on the Tennesseee River. The voltage capacity
of the connecting line is 120.000. or nearly double that of
the line from the two Ocoee plants to Chattanooga and Knox-
ville.
The two circuits, each three-phase, consist of six heavy
aluminum cables. One circuit is of 250.000 and the other of
400,000 circ. mils area. At Hale's Bar the Tennessee River
is spanned by a 2331 -ft. stretch of steel-core aluminum cables
of %-in. diameter, suspended between four steel towers 60 ft.
high. The towers are set on high elevations so that the
cables are 115 ft. above the water. There are 435 galvanized
steel towers supporting the double circuit between Hale's Bar
and College, the towers being spaced at intervals averaging
453 ft. The tops of the towers are connected with a %-in.
ground wire.
The insulators of the high-powered cables are the sus-
pension-type porcelain disks, eight units to each insulator, ex-
cept at the river crossing, where specially constructed in-
sulators are used to support the heavy span. They are made
of treated wood strips inclosed in oil-filled porcelain shells,
the largest of the kind ever made; no others like them are in
use. The first and eighth disks are 6% ft. apart, and the
mechanism holds the cable 12 ft. from the steel tower's sup-
porting arm.
JOHX HcDOXALD
John McDonald, an engineer well known locally and in the
N. A. S. E., died of heart failure at his home in Ludlow. Vt.,
Dec. 17, 1914. He was 63 years of age. The greater part of
his life was spent in engineering work.
Award of the John Scot* Medal — The city of Philadelphia,
acting on the recommendation of The Franklin Institute, has
awarded the John Scott Legacy Medal and Premium to Arthur
Atwater Kent, of Rosemont, Penn.. for his "Unisparker," an
essential element of the Atwater Kent ignition system for
automobiles, consisting of a contact breaker, governor and
distributor, in one structure, and to Elmer Ambrose Sperry, of
New York, X. T.. for his gyro-compass.
On battleships under action, the shifting of large masses
of magnetic material precludes the use of the magnetic com-
pass, and even on ordinary iron vessels, the material of the
ship and its disposition must be compensated for. The gyro-
compass is entirely nonmagnetic and is unaffected by the
proximity of iron.
The Engineering Foundation — A noteworthy incident in the
history of the profession of engineering in the United States
will be the inauguration of The Engineering Foundation on
Jan. 27, 1915, in the auditorium of the United Engineering So-
ciety in Xew York. The Engineering Foundation is a fund
to be administered for the advancement of the arts and
sciences connected "with engineering and the benefit of man-
kind, the basis of which is the initial gift of a considerable
sum by a noted engineer for this purpose. The American So-
ciety of Civil Engineers, the American Institute of Mining En-
gineers. The American Society of Mechanical Engineers and
the American Institute of Electrical Engineers are to be rep-
resented equally in the administrative Board of The Engineer-
ing Foundation by election by the Board of Trustees of the
United Engineering Society, which had been made the cus-
todian of the fund. All members and friends of the' engineer-
ing profession are invited to these inaugural ceremonies.
Massev Machine Co.. Watertown. X. Y. Catalog Xo. 7.
Governors, Class M. Illustrated, 16 pp., 6x9 in.
Watson-Stillman Co., Aldene, X. J. Booklet. Kromax
leather packings. Illustrated, 16 pp., 3%x6 in.
Chicago Pneumatic Tool Co., Fisher Building, Chicago. 111.
Bulletin No. 34-S. Small power driven compressors. Illus-
trated, 16 pp., 6x9 in.
Neil & Smith Electric Tool Co., Cincinnati. O. Catalog Xo.
4. Portable electric drills, buffers, grinders, screwdrivers, etc.
Illustrated. 56 pp., 6xi> in.
The Cling-Surface Co., of Buffalo, X. Y., has prepared a
special calendar for members of the N. A. S. E., copies of
which it will gladly mail free on request as long as the sup-
ply lasts.
The Lagonda Mfg. Co., Springfield, Ohio, has just published
B new 32-page booklet on the Lagonda Boiler Tube Cleaners.
It is called catalog L-S — contains many illustrations showing
details of construction and also cleaners in actual use, and
copies are mailed on request.
The Xew York office of the Kerr Turbine Co., Wellsville,
N. Y., will hereafter be located in Room S01, Singer Bldg.
Annex. Mr. Benjamin G. Fernald has been appointed district
manager. Mr. Lawrence G. Hanmer will continue to be asso-
ciated with the Xew York office and arrangements have been
made for prompt and effective attention to all inquiries.
The Files Engineering Co., of Providence, steam specialists
and engineers, have established a branch office at 120 Kossuth
St., Bridgeport, Conn., where they will contract for power,
heating, drying, evaporating and steam specialty 'work of
every description. They request catalogs and other literature
descriptive of apparatus and appliances relating to these lines
sent to their Bridgeport office.
"Cochrane Multiport Vales," a booklet of 72 pages, just
issued by the Harrison Safety Boiler Works, 17th and Clear-
field St., Philadelphia, Penn., describes the multiport valves
introduced by that concern for back-pressure, relief and
vacuum service, flow service in connection with mixed flow
turbines, and check-valve service with bleeder or extraction
turbines. In addition to full descriptive and tabular matter,
the book contains numerous diagrams and layouts, also data
on the effects of air in condensers and upon turbine perform-
ance.
A booklet worth having is the new booklet issued by the
United States Graphite Co., Saginaw, Mich., on the subject
'"U S. G. Co.'s Mexican Graphite Paint — Its Uses and Users."
It is an excellent booklet from the standpoint of printing as
well as subject matter. Fine halftones are used throughout,
illustrating many buildings, bridges, etc., where the paint
was used. Complete details are given about graphite, the
care used in making the paint, and the "reasons why" it
should be used. And letters are used to show what success
users have had with it. It's a 64-page booklet and is sent on
request to anyone interested in graphite paint.
Among recent sales of Bruce-Macbeth gas engines, made
by the Bruce-Macbeth Engine Co., Cleveland, Ohio, are the
following: Magnolia Pipe Line Co., Fort Worth, Tex., two 150-
hp. natural gas engines; Thompson Milling Co., Lockport,
X. Y., one 350-hp. natural gas engine; Village of Wellington.
Ohio, for municipal lighting plant, one 125-hp. natural gas
engine: Kloss Ice Cream Co., Wheeling, W. Va., one 90-hp.
natural gas engine; Broadway Market Co., Detroit, Mich., one
90-hp. artificial gas engine; one 70-hp. two-cylinder natural
gas engine to J. K. Mosser Co., Parsons, W. Va. ; one 150-hp.
four-cylinder natural gas engine to Victor Auto Parts Co.,
Cincinnati, Ohio: one 70-hp. two-cylinder natural gas engine
to the Willson Ave. Lumber Co., Cleveland: one 150-hp. four-
cylinder natural gas engine to Chisholm Steel Shovel Works.
Cleveland, Ohio.
The annual report of the Xorthern Equipment Co., Erie,
Penn., manufacturer of the Copes boiler feed water regulator
and the Cope pump governor, shows that 1914 was the great-
est year in tl.c history of its business. Its sales exceeded its
next best year by 9%%. Larger quarters have again become
necessary," and in order to provide this it has purchased the
plant, equipment and business of the Erie Pump & Engine
Works The new plant is located in the heart of the city
and affords excellent snipping facilities. Mr. J. H. Dougherty,
formerly with the International Steam Pump Co., has been
engaged to take charge of centrifugal pump design, and the
well known line of Erie centrifugals is to be improved and
extended. A consolidation of the two companies is being
perfected and the new combination will be known as the Erie
Pump & Equipment Co. The officers of the new company are:
E. VT. Xick. president and treasurer: D. H. DuMond, vice-
president; V. V. Veenschoten, secretary. Mr. John G. Pfadt,
former president of the Erie Pump & Engine Works, is not
connected with the new company.
TREASURY DEPARTMEXT, Supervising Architect's Office,
Washington. D. C, January 5. 1915. — Plans and specifications
are now approaching completion for a central heating, light-
ing and power plant, to be erected in this city under the
direction of this office. These plans and specifications will
be readv for delivery on or after January 15. Bids may be
submitted for the entire work or for any one of the following
sections: Power plant building complete, with steel stacks;
boilers; generating apparatus; pumping equipment; con-
densers; coal and ash handling apparatus; steam and water
piping; switching gear; tunnels; substation apparatus, etc.
Prospective Didders should immediately submit to this office
applications for plans and specifications, stating the portions
of the work upon which they desire to bid. If it appears
that the applicant is in a position to bid on all of the work
in anv one of the sections of the .project, or upon the entire
work, the plans and specifications will be forwarded. Xo
plans or specifications will be furnished sub-bidders or others
not In a position to submit a bid on all of the work comprised
in at least one section. The Department will be able to allow-
only about 15 days for the preparation of estimates. At the
time plans and specifications are forwarded to bidders the
date for the opening of bids will be stated, and this date
will not be extended. O. WEXDEROTH, Supervising Archi-
tect.
.rfJ^g&SSfe,
\&. . vBL /$.
Vol. 41
;/
POWER
\K\V YORK, JANUARY 36, 1915
(I I
S ■ : :: ; !
V ;:::■■
X''
^^.y
No. 'I
GUESS IPIUL STECM AE©UM1 A WMElLEo00
113
P 0 W E R
Vol. 41, No. 4
'©wer Plaint ©f tlh© J,
>tefe©mi
By Warren <». Rogers
SYNOPSIS — A plant in wli\ i y was
required. The problern was solved by putting in a
mixed-pressure turbine, utilizing the exhaust steam
from the engines and numerous pumps. The con-
densing water goes to a cooling towi r which, owing
to tlw restricted ground area, is supported on con-
crete posts iii the yard.
When an engineer puts on his "Stetson," lie gives but
little thought to the power plant which made the manu-
facture of this hat possible or to the immense factor?
As there are 14 boilers in the three boiler rooms, all
connected to the same steam main, and as the turbine is
,i recent addition to the plant equipment, figures regarding
the actual saving in fuel are not available. The forego-
ing, however, gives a fairly good idea of what the turbin
i> doing in the way of economy.
Exhaust-Steam Lines
The exhaust line from the two 30x48- and the two
24x48-in. engines begins with a 12-in. pipe and increasi
to 14-, 16-, 18- and 20-in., as indicated by Fig. 2. The
other 30x48-in. engine exhausts into a 16-in. line, which
Pig. 1. General View of the Engine Room
in which it was made. While the power plant of the .1. 1'.
Stetson <-'".. Philadelphia, Penn., is nut new, it has in-
teresting features, and illustrates how more power ami
greater economy may be obtained in a plant where the
engine room cannot well accommodate additional units.
Fig. 1 i- .-i general view of the engine room, which
houses three 24x48-in. and two 30x48-in. horizontal en-
gines, one Nio\8-in. single-acting, vertical reciprocating-
engine, and a Rateau-Smoot mixed-pressure -team turbine
which uses the exhaust steam from such engines as are
run. Before the turbine was put in, both of the large
units and two of the small ones were used, leaving one
250-kw. unit as a reserve. <>u the average these engines
consumed 2 M ■_■ lb. of steam per horsepower-hour. With
the turbine, but one 500-kw. unit and one 250-kw. set
are operated, with a large ami two small units held as re-
serve. This means cutting out a 375-hp. and a 750-hp.
unit, which at 24% lb. of steam per hour represents a sav-
ing of 27,562 lb. of live steam per hour. Crediting the
boilers with evaporating 9 lb. of water per pound of coal
tired, a saving of 3062 lb. of coal would be had. This
makes 1 1 L. tons per hour, or 15 tons per day of 10 hours,
and is a saving of $48.75 per day if the coal cos! is $3.25
per ton.
also receives the exhaust from the steam pumps, and a
I6x42-in. Corlis engine used to belt-drive a lineshafl
in the pump room. This pipe line loops one end of the
engine-room basement and joins the 20-in. main exhaust
header. Exhaust steam is not only utilized by the turbine.
Fig. 2. Diagram of Exhaust-Steam Piping
but some is also used in the two 3000-hp. vertical heaters,
which are piped as shown. Both are connected to a 30-in.
atmospheric exhaust. The exhaust and the main steam
lines in the basement (Fig. 3) are supported by bri< k
January '-(3, 1915
P ( > W E i:
113
Fig. '■]. Live- and Exhad
Iteam Mains
piers; the lower pipe is the exhaust lino. The motor-
driven circulating pump supplies the surface condenser,
win' h is further to the right, but not shown.
Turbine ami CONDENSING Aitaiiatus
The low-pressure turbine (Fig. I) is of 750-kw. ca-
pacity, generating 230-voll direct current at 1500 r.p.m.
It is at the end of the engine room and rests on a con-
FlG.
Combined Natural- and Forced-Draft
Cooling Tow eb
crete foundation. In the basement below Utv turbine is
the e leasing apparatus. The surface condenser has 4300
sq.ft. of cooling surface made up of 1-in. outside diameter
No. 18-gage tubes. Condensing water is supplied by a
12-in. centrifugal pump, having a capacity of 3000 gal.
per min., aad being driven by a ffl-hp., 220-volt, direct-
current motor at 950 r.p.m. The "rotrex" air pump is
driven by a 14-hp., 220-volt, direct-current motor.
Fig. 1. Low-Peessuee Steam Tubbine
Owing i" a restricted ground area, the cooling tower is
in the yard and rests on a concri upported by
concrete posts (Fig. 5). The tower is 27x21 ft. and is
', 5 ft. high. The condensing water is led by a com-
bination of forced and natural draft, the forced draft be-
ing supplied by four 8-ft. fans driven by direct-con-
I motors. The hot water from the condenser is used
in the factory for manufacturing purposes, thus utilizing
the heat imparted to it in condensing the -team, the tem-
perature of the water being 90 deg. The water from the
cooling tower goes to the condenser at 89 deg. during the
ordinary summer temperatures.
There are more than 500 motors throughout the factory
-
Fig. 6. Dieect-Cdebent Switchboaed
which range from '/,. to 70 hp. in capacity. The load on
the turbine is from 270 to 3000 amp., and that on the
engines is from 3000 to 3500 amp. There is an average
load of 6000 amp., or about 1500 kw.
The motor and lighting circuits are controlled from a
1 1-panel marble switchboard (Fig. 6), the generator pan-
els showing in the foreground. The turbine generator is
controlled from a bench switchboard (Fig. 1), between
the second and third engines.
Boilers and Pumps
Steam is supplied for the engines and for manufactur-
ing purposes by fourteen water-tube boilers in three
rooms. Fig. ! shows the five large boilers.
Coal is delivered bv wagons from the street into two
Hi
POWEE
Vol.il, No. 4
Fig.
One of the Boilei: Rooms, Containing
Five of the 14 Boilers
of the boiler rooms, which are below the street level,
but in the third room it is elevated by a bucket conveyor
to a storage bin. Ashes arc wheeled to an ash conveyor
and elevated to a bin on the outside of the boiler house.
from which they are loaded into wagons on the street level
and carted away.
The pump room ( Fi.u'. 8) is a fair-sized steam plant
in itself. The largest unit is the 16x42-in. engine, al-
ready mentioned. From the lineshaft which this e
drives there are belted a 5%x8- and an SxlO-in. triple-
plunger house pump for supplying fresh water to the fac-
Fig. D. Belt-Dkivkx High-Peessubb Blowers
ton, washrooms, etc. Both are equipped with regulators
which maintain a pressure of f)0 lb. on the pipe system.
Air for the factory is supplied by two compressors, one
belt-driven from the lineshaft, the other being a com-
pound steam-driven unit. Both supply air at 90 lb. pres-
sure.
The factory has a system of vacuum cleaning. Vacuum
is produced by two vacuum pumps, driven by a noiseless
chain drive; each has a 24xl8-in. cylinder and rated at
60 hp.
The refrigerating system not only keeps a proper tem-
perature in the storage room for hat bodies, hut it cools
the drinking water lor the factory. Since the introduction
of this system of cooling the drinking water the rate
of sickness among the workmen has greatly decreased. The
system lor cooling the brine supply consists of one 45-ton,
14x32*-in. ammonia compressor, two 5.\4-in. brine pumps,
and the necessary apparatus. The drinking water is
pumped to the factory by two lOxlixlO-in. duplex steam
pumps.
Boiler-feed water is supplied by a 1 I & 20xl0xl8-in.
and a 12x8V&xl2-in. duplex pump, working against
120 lb. pressure. Among the other apparatus is a 12x
7xl0-in. cold-water house pump, two vacuum pumps For
the factory heating system, ami a hydraulic pump for pro-
ducing water pressures up to 300 lb. per sq.in. for the
factory on various presses used in the process of manufac-
ture.
Two Views or the Pump Room, Which Is ,\ Fair-Sized Powbe Plant in Itself
•January 26, 1915
r u w E i;
115
At one end of the pump room is a set of five belt-driven,
high-pressure blowers ( Kg. 9) for the gas-heated irons
in the factory. Each is fitted with a tight and loose pullej
and is driven from an overhead shaft.
M [8CELLANEOTJS
For the convenience of the employees a garage has been
built, having steam heat, electric light, hot and cold wati r,
compressed air, water for washing cars, asbestos and iron
lockers, and a small machine shop for light repair work;
also a charging station for electric automobiles. <htt in
the yard there is a rack for the accommodation of bicycles ;
they are stacked on end to' occupy a minimum of room. A
hospital is also maintained by the company and a large
auditorium is available for entertainments.
The factory is wired with six trunk telephone lines,
serving over "-'llO instruments, placed at convenient points.
Tli.' •.'■.' elevators are equipped with telephones, making ii
hi easy matter Tor heads of departments to he reached
when away from their desks.
A system of call hells has also been put in, so that no
matter where the head el' any department may he. the
ringing of his signal denotes thai his presence is re-
quired at his office.
anioum .if -team condensed per square fool of radia-
tion under average demand conditions.
When used in connection with the atmospheric system
Pointer'^, . |
1 : ■}]
s p
Valve Shown Open
Se< lie, rHEOUGH Atmospheeic Eadiatoe
Valve
of steam heating, it affords control of individual radia-
tors, and just the amount of steam needed is used in
each radiator to maintain the desired temperature.
PRINCIPAL EQUIPMENT OF THE JnU.V B. STETSON I 0 POWJ :: i 1 i
so. Equipment
; F.iiL'n:' b
I Engines
Ringing
Turbine
Generators..
I Generators..
Generator. .
Generator. .
Engine
Cm, a n- ;
Motor
Pump
Pump
Motor
Beaten
i Boilers. . . .
Boilers
Pump. .
Pump. .
Compressor.
Compressor .
Pumps
Compressor .
Pumps
Pumps
Pump
Pump
Pump
Pump
Pump
Pump
Pump
Blowers
Tower
Kind
Reciprocating.
Reciprocating .
Reciprocal i: g.
Rateau-Smool
Direct current
Direct currenl
Direct cue
Direct curri il
Direct current. . . .
Centrifugal
Air Rotrex
Direct current
Bern-man . .
Parker down draft
Parker down drafl
Parker down draft
Triple plunger
Triple plungi r —
Simple
Compound
V:
24x48-in
30x4S-in .
8x8i-in
750 kw
250 kw
500 kw
use I lerating Condition-
Main units 90
Main units '.ill r .p.m. saturated steam. .
Used after work li ur- Saturated steam
Main unit . . 1500 i
Main generators - !in r.p
i generato:
exhaust
I
"in volts, :
750 kw
4200 sq.ft coi li [i ul i
70 hp. .
12-in
ls.x36-in
14 hp
3000 hp
"i00 ho.
600 hp
750 hp
5JxS-in .
s.\10-in
Ammonia
Power plunger
Duplex. ..
Dunlex, cotnp
Duplex
Duplex
Vacuum
Vacuum
Hydraulic
Hydraulic. .
High pressure .
Forced and natural
draft
Forced draft
Direct current
5xt-in
10z6zl0-in
I4i20xl0j 18-i
12xV,xl2-in
12x7xl0-in
Sxl2xl2-in...
8xl2xl(5-in...
12x9ixl2-iu..
Used after hour., 250 volt*
Main generator 1500 r.p.m., 230 volts, 3000 amp,
Driving lineshafl , pump 101 r.p.m
With turbine. , . 27J-in. vacuum
Driving circulating purr.; 950 r.p.m., 220 voll
With condenser 950 r.p.m
With condenser 225 r.p.m .
Driving air pump 225 r.p.m . 220
Feed water Exhaust steam
Steam generation. Hand fired
Steam generation . . Kami fired
Steam generation. . Band fired
House service . Bell driven
House service Belt driven
Factory use 90-lb. pressure
Factory use... '.t'-lb. pressure
Vacuum cleaning systi , ' Lain 1" It drivi n
Refrigeration Steam driven
Pumping brine Belt driven
Cold drinkinti water
Boiler feed Again--
Boiler feed Vgain3l L20-lb. pressure
Cold water for factory
Beating Bystem During cold weather
Beating system .. . During cold weath r
Factory hydraulic system. Steam driven
Factory hydraulic systi m Steam driven
For gas ( ias heated irons
Maker
igine Co.
Brown Engini Co
Westinghouse Machine Co.
. Dynamo & Kngine Co.
' locker-Wheel : '
Crocker-Wheeler Co.
Westinghouse Elcc, ,v- Mfg. Co.
v Dynamo tic Engine Co.
Liners Co.
C. 11. Wheeler Mfg. Co.
General Electric Co.
C. H. Wheeler Mfg. Co.
C. H. Wheeler Mfg. Co.
Sprague Electric Works
Kelley & Sons
Parker Boiler Co.
Parker Boiler Co.
Parker Boiler Co.
Piatt Iron Works
Works
In
In
Vac
Cle
La Vergne Mch. Co.
Fairbanks, Morse ( <,
Hem-v R. Worthington Co.
C. B.Wheeler M
Advance Pump A Compressor Co.
fienry K. Worthington
Union Steam Pump Works
Union Steam Pump Works
C. H. Wheel - M
Union Steam Pump Works
i Car Furnace Co.
-1 No. 3—1 No. 4.
27x27x7o-ft . Cooling condensing water Forced and natui . . C. H. Wheeler Mfg. Co.
8 ft. Cooiing towet Motor driven c. H. Wheeler Mfir. Co.
Driving tower fans 220 volts ( leneral Elect
In connection with the engineering staff, Chief Engi-
neer T>. J. Wattis also has supervision of the machine shop,
the force totaling 140 men.
The improved Adsco radiator valve, illustrated here-
with, is calibrated to supply a definite amount of radia-
tion, and is designed to supply steam to standard sizes
of radiators of the hot-water type.
The various capacities of valves are arranged in mul-
tiples of five square feet of direct radiation. These ca-
pacities have been established as the result of tests to
determine the ratio of the amount of steam under a
given pressure passing through the radiator valve, to the
The valve body is fitted with a graduated disk at the
nutlet. The valve travels from a closed to a full open
position with a three-quarter turn. A pointer on the
valve stem indicates on the graduated disk any fractional
position between the two extremes. The claims for this
valve, manufactured by the American District Steam Co.,
North Tonawanda, X. V.. are economy, freedom from
clogging and that it will not stick after remaining idle.
A Common Error when trouble appears in the form of
scored cylinders and valves is to hold the oil responsible
for the damage. After the necessary repairs are made and
possibly the mechanical cause of the trouble removed, an-
other oil is substituted with very satisfactory results. Both
oils may have come from the same field, had the same com-
position and physical properties, in fact, be the same oil.
but from barrels with different trade names, so that the ad-
miration for the second, together with the condemnation of
the first, would be unjustified.
116
P < ) W B E
Vol. 41, Xo. 4
E-jagpim©
Recently the John Lauson Manufacturing Co., New
Kolstein, Wis., placed on the market a four-cylinder, ver-
tical, heavy-duty oil engine, of 80 and 100 hp., with cyl-
inders lO'.ixlv! in. and 11x12 in., respectively. Primar-
valve F is rotated by the governor, gradually closing the
ports /' and I. so thai a greater proportion of the air is
deflected through the nozzle, thus maintaining a prac-
tically uniform velocity al this point The high velocity of
the air and the feeding of the fuel through a number of
.small holes insure atomization and a proper mixture be-
fore the fuel passes to the cylinder. A butterfly valve
ily, llit. engine is intended for small lighting-plant work,
the regulation being close enough to permit operating al-
ternating-current generators in parallel.
The general construction is shown in Fig. I. The crank
case is of the two-piece type split horizontally at the center
of the shaft. The valves are mechanically operated and
located in the head. Make-and-break ignition is employed
ami cooling water For the cylinder jackets is supplied by
a pump driven through a chain and sprocket by the main
shaft.
The feature of the engine is the special carburetor or
"Venturia" mixing nozzle, of which there is one for each
cylinder. The principle of this device is to maintain a
high velocity of air through a venturi tube having radial
holes iii its restricted portion through which the fuel is
drawn by the suction of the air. The amount of air pass-
ing through the nozzle is controlled by the governor. The
carburetor consists of a cast-iron body containing a cyl-
indrical throttling chamber within which is fitted the bar-
rel valve shown at /■'. Fig. "2. This valve is controlled by
the governor through a bell crank and a horizontal shaft
running the length of the four cylinders.
Fuel is admitted through the nozzle J), which has two
sets of holes. The upper set is for the admission of gaso-
line I'm- starting and kerosene for running, and the lower
set for the admission of water to prevent premature ig-
nition at full load. Three needle valves, one for each
liquid, control the supply to the nozzle. On each side of
i in' nozzle D is a port 7, and when the engine is at rest
these ports are wide open. Below the nozzle the governing
port P will also lie open. Thus, a certain proportion of
the air passes through ports I and the balance through
the nozzle D. As soon as the engine picks up in speed,
\oiTuii\AL View of Lauson Engine
trolled by the handle I: i- provided to facilitate start-
ing and for additional air adjustment at full load.
The igniters arc of standard make-and-break design and
operated from the camshaft. Two timing adjustments are
provided, one individual and one simultaneous, the latter
being used to shift all igniters at time- of starting bv a
rni
PLAN
FlO. '
SECTION X-X
I II I i I I i i \i. ( II \M lift
single lexer. The mechanism is shown in Fig. 1. An in-
sulated brass bar charged by a gear-driven alternating-
current magneto is placed above the igniter plug. A
spring coming in contact with the bar puts the igniter in
the circuit and eliminates the need for wiring.
For starting, a special device furnishes the air in turn
to each cylinder. The device consists of a main body
having lour radial air ports connected by piping to the
different cylinders. These ports are covered and uncov-
ered by a rotary disk valve having one port. The valve is
January 86, 1915
i'o \v ki:
m
held to its seat by the pressure of the air and is free to re-
volve when the air is shut off. Rotation is effected by
means of a flexible coupling between the device and the
camshaft. Com pressed air, provided in the usual way. is
admitted to the cylinder through a small valve in the
head, which is shown at the left in the sectional view of
the engine. As soon as the engine lives, this valve is held
to its seat by the pressure within the cylinder. 'The en-
gine is run tor about ten minutes on gasoline and the fuel
i- i hen changed to kerosene.
The fuel reservoir has three compartments; one for
gasoline, one tor kerosene and one for water. The gasoline
and kerosene compartments aii' kept full by means of
pumps, and the water is controlled by a float inside the
chamber.
The governor is of the vertical flyhall type driven from
a bevel gear on the camshaft. It is inclosed, as indicated
in Pig. 1, ami the speed may he adjusted by shortening
oi- lengthening the rod from the governor to the regulat-
ing valve under its control. Lubrication of the five main
bearings and the cylinders is effected by a force-feed
pump. The connecting-rods depend on splash lubrication.
To obviate the noise and wear of a bevel gear between
a jackshaft belt driven by a motor set on the engine-room
floor and a centrifugal pump some distance below, C. P.
Hall, chief engineer of the Rookery Building, Chicago,
Diagram of Coupling
invented an ingenious quarter-turn coupling consisting
of two heads, bored to receive six rods of equal length.
The jackshaft is horizontal and the pump shaft vertical,
as indicated in Pig. •.'. The coupling heads are merely
solid pieces, hored lor and keyed to their respective shafts.
Within one-half inch of the circumference and spaced
evenly around it, six holes are drilled to comfortably
receive the rods. These rods are twice the length of a
head plus the shortest exposed Length shown in Pig. 1.
They are free to turn in their sockets and slide length-
wise as the relative movements of the heads demand.
When in the extreme position .1. the ends of a rod arc
midway in the heads and in position I! the ends are flush
with the outer faces.
At first glance if would look as though the rods would
twist together in a single turn of the heads. That this
is not i In- case has been successfulbj demonstrated by .Mr.
Hall. Several couplings of the same kind as illustrated
are in use in his plant. Pig. 2 shows a coupling conned
ing a jackshaft, driven by a 3-hp. motor, to a 3-in. cen-
trifugal pump. The speed is 500 r.p.m., and at a dis-
Fig. 2. Jackshaft and Coupling with Hood Removed
tance of only a foot it was impossible to detect any noise
from the coupling. The rods are well greased and as a
precautionary measure a hood is placed over the coupling.
The largest coupling is for a LO-hp. motor, but there is
no reason why higher powers could not he transmitted:
ii is merely a questi if size. To be safe tin1 combined
area of three rods should I qua! to the area of the shaft.
On large bearings where grease is used for lubrication,
'■'» the grooves are not cut in line with the center of the
bearing, par! of the journal is without lubrication. Re-
mad( Fr opper-wirc gauze, perforated copper
Keystone Grease Retardeb
icrh
but
rati
of
od c
the,
leather ha\
have been
been used with
ntiivly satisfac-
plates,
grease,
tory.
It is claimed that the difficulties usually experienced
in lubricating such bearings have been overcome by the
use of the Keystone babbitt-metal retarder, illustrated
L18
p o w e t;
Vol. II. No. -1
herewith. This retarder is bent to conform to the curve
of the journal and is made slightly narrower and shorter
han the grease well ; the grease is placer] on top of the re-
tarder in the usual manner.
The under side of the retarder is grooved, and one edge
ij each bar is rounded, so that the grease is wedged be-
tween the retarder and the journal instead of being
scraped off. The grease i- spread over the bearing surface
and fed into the groove in the bearing cap, providing effi-
cient and economical lubrication.
This device was designed by Thomas 0. Organ, eon-
suiting engineer of the Kcvstone Lubricating Co.
SYNOPSIS — Cylinder a plain casting. Balanced
oppet valves contained in heads. Valves positively
opt rated by eccentric on lay-shaft and cam. Re-
lief valves avoid over-compression.
Two new types of engine being built by the Nordberg
-Manufacturing Co., of Milwaukee, Wis., are shown in
the simp photographs. Figs. 1 and 2. The formeT is an
L8x32-in. poppet uniflow engine Tor the city of Bartow,
Fla. It will drive directly a 150-kw. alternator at 164
r.p.ni. Fig. 2 shows an I8x24-in. poppet valve "coun-
>inx|pini©s
tional flow. In the usual engine there is a reversal of
steam flow; on the outstroke the How is toward the ad-
vancing piston, and on the return stroke the same steam
flows toward the cylinder head. In the uniflow engine the
steam is admitted at the ends, as in the ordinary engine.
but is exhausted through ports at the center of the cylin-
der, the piston acting as its own exhaust valve, as shown
in Fig. :!.
The uniflow principle has to do with only the cylinder
and exhaust-valve design, s,, that an engine of this type
may he fitted with any style of valves and valve-gear
Ini' controlling tin- steam inlet. Corliss valves may lie
Fie. i. Norpp.erg Poppet-Yai.ve Uniflow Engine, 18x32-In. Ctlindeb
terflow" engine which will he directly
connected to a 175-kw. alternator and
run at a speed of 164 r.p.m. Waupun,
Wis., is t«> have this unit. All but
the lowi !■ balf of I h flywheel on each
engine is assembled. The simplicity
of design will lie apparent, especially
that of the uniiioM engine.
The word "counterflovt
make clearer the distinction between the
uniflo tigine into which
the steam o linarj way.
feet d within rei
confusion i the different
' inn aiean. The word "uniflow" has
been coined to designate an engine in
which the steam flow » [thin the cylin-
der is only in one direction — unidirec-
IT.i. 2. Poppet- Valve Cotjnterflow Engine, 18s24-In. Cylindeb
January 86, 1915
P 0 \V E 17
119
used, and a nttmber of Nbrdberg uniflow engines have
been so equipped. A description of this engine appeared
in the June 11, 1912, issue of Power. For high pres-
sures and superheats, however, poppet valves are to be
preferred.
Line drawings of both of the new engines are shown
in Fies. I and ■">. The frame is the standard Nbrdberg
Pig.
Sectional View of Uniflow Cylinder
heavy-duty design with an oil pan cast integral under the
crank and rod. The bearing, rods, guides and cross-
head are also standard. The cylinders of these engines
are of plain cylindrical form without steam chests — this
to avoid distortion under high superheat. The steam
removed by backii S i the rack. The cylinder may
then be removed from the crank-end head. The valves
are of the double-beat balanced poppet design, shown
together with the operating cam and follower in Fig. 7.
The valves seat on removable cage.-, which are steam
tight in the cylinder-head casting. This construction
was adopted to obviate the distortion common to seats
cast integral with the cylinder casting. These cage- can
be renewed or removed for regrinding. No stuffing-boxes
or metallic packing are used mi the valve stems. These
are ground to a close lit and then made tight by grooves
which prevent leakage, on the principle of the labyrinth
used in centrifugal pumps, compressors, etc.
The stubby, compact appearance of the valve bonnets
is due to the absence of springs tor closing the valves.
In this construction the valve is opened and closed posi-
tively by one cam oscillated by an eccentric on the lay
shaft, the throw of which is varied by an inertia and
centrifugal governor located between the eccentrics. The
design of cam, eccentric and governor is shown by the
illustrations.
In the counterflow type of engine there are four cams —
two at each end — one for the steam inlet, the other for
the steam exhaust valve. In the poppet uniflow engine
there are only two cams — one for each steam-inlet valve —
the exhaust, as already explained, being controlled by the
piston itself.
The uniflow engine is primarily a condensing engine.
Expansion may be carried from high boiler pressure to
::('> in. of vacuum within one cylinder at as good econ-
omy ts ordinarily obtained with a compound condensing
engine, owing to the reduction in in le oudensation
Fm. I. L<
tudinal Yii:u ind Transverse FSe< rn
i T \ : ri.nu Cylinder
is led to each valve separately from the throttle valve
placed under the floor. The cylinder heads arc cast sep-
arately and contain the valves, and. as shown in Fig. 3,
the design is such that the entering steam jackets the
ends of the cylinder.
The arrangement of the cylinder and heads is shown
in Fig. (I. To dismantle, tbe head with the valves is
effected by the uniflow construction. This typo of en-
gine has the further advantage of large overload capacity
and a flat steam curve. It is claimed that it will carry
100 per cent, overload with a 10 per cent, increase in
steam per horsepower-hour over the full load rate. At
half load the steam rate is about 5 per cent, in excess of
normal.
120
I'ow e i;
Vol. 11, No. 4
An objectionable feature of the uniflow engine is the
high compression obtained when the vacuum is lost or
when the engine is run noncondensing. In the present
design this difficulty has been met by placing an automat-
ic relief valve at each end of the cylinder. One of these
valves is shown in Pig. 1. It opens from the clearance
By
C. W. IIaynes
One of the comnnn troubles encountered in the en-
gine room is the undue heating of crankpins. Not prop-
erly relieving the brasses at the parting is one cause, and
Pig. 5. The Poppet-Valve Cylinder with Positive Hiuh-.Speed Valve-Geab
Fig.
6. Cylinder lnd Heads, before Covered by
I, lgging, ami Valve-Gear
Pig. ". Balanced Poppet Valve with
Operating Cam and Follower
space and discharges the -train in it- superheated state
at the end of compression back to the steam piping; over-
compression is thus avoided.
I'niii pi nu. Mater with Compressed Air — A 12x14 '4 xl 4-in
compressor furnished air tor :i mine pump 14xsx3 in.
No other uses wen made of the air and the air line
was tight. Indicator cards were taken from both the
air and steam cylinders of the compressor. The valve ad-
justments were good and the pistons tight. The total pump-
ing head of the pump, Including suction and pipe friction,
was 103.1 ft The water pumped was measured by a 4-in.
orifice in a tank at the surface. The over-all efficiency from
steam indicated horsepower to useful work done on the
i i was only 6.81 '..' .
another is in riot allowing sufficient clearance at the
fillets.
A lirass with no clearance may run for some time with
little or mi trouble, but after heating has taken place,
it will he found upon taking it down that it has (level
oped a decided tendency to grip the pin. 'to avoid this
the clearance should he ample to reduce the bearing on
the brass to the crown of the pin.
In roundhouse work, in a locality where the road was
hilly, it was the common practice to reduce the area to
nearly one-half of the arc of the brass without had re-
sults. It would seem that this excessive clearance would
January 26, 1915
POW E R
121
result in heating, but it did not, even when the engines
were pulling hard and running at high peed, or going
down hill with the steam shut off, at which times the
thrashing of the rods tries the pins severely. This shews
that seemingly excessive clearance will not cause heating.
The locomotive engineer ha- troubles that the station-
ary engineer does ii"t experience. In dry times the wind
blows the dust, and in wet weather the mud between the
tic- i- thrown up into the bearings; then when the oil is
used up, out goes the babbitt. If the babbitt is all thrown
out, there can he hut little injury, hut it the engine is
-topped and the partly melted babbitt is allowed to freeze
on the pin, cutting is liable to occur.
It is essential that th>' brasses !»■ properly fitted and no
high spots left to cause severe local heating. All of the
flaky substance which covers a brass after heating should
he filed or scraped away. It is not necessary, however,
to -crape away all the file marks, which, being crosswise
afford lodgment for oil and are beneficial in newly fitted
bearings.
A soft babbitt gives satisfaction when used in the in-
serts, hut it should be peened in or it will get loose. Good
results have been secured by fitting the brasses first and
babbitting afterward. In doing so it is easy to leave the
babbitt a little higher than the crown of the bras-, insur-
ing the benefit of the good qualities of the babbitt.
The following experience illustrates the benefits of bab
lutt inserts in bronze bearings. Certain gasoline engines
using phosphor bronze on the crankpins gave trouble fre-
quently until we put two rows of button inserts across
each brass. Later, the use of phosphor bronze was discon-
tinued in favor of a high-grade antifriction metal.
Not all the trouble with crankpins, however, is due to
mechanical fault.-. The quality of the oil is responsible
in many cases of heating. The superintendent one day
wanted to know the cause of the ] r condition of the
crankpin bearings ol a two-cylinder engine. lie said
the engine must have run dry earlier in the day. It was
contended, however, that if the engine had run dry. tiic
metal would have melted, but with a poor grade of oil
the bearing hail heated gradually, softening the metal and
allowing it to crush out at the >ides. That -ante grade
of oil diil give much trouble later.
When a newly fitted brass is put in hard service, a little
tallow in the clearances help- to prevent heating. Fast-
running engines must he kept snugly keyed up or the
brasses and straps will chafe. When straps are off it i<
advisable to look them oxer for cracks, especially in the
corner.-, where they are often easy to see. It is. however,
good practice to wipe them carefully and paint with a
thin coat of white-lead paint, then strike the strap or rod
end with a soft hammer and if there are any cracks the
oil in them will discolor the paint, thus indicating the
extent of the fracture.
Brasses running loose at high speed will pound them-
selves hoi and may fracture the running part:-.
Foir ©ed°Draftt CooMjzhe Toweir^
liv E. Raymond Goodrich
SYNOPSIS— Analyses mi, I test 'lulu of forced-
draft cooling towers, with heat-temperature curves
fur moist air, and examples illustrating linn- use.
In a rapidly increasing number of condenser installa-
tions, some sort of water-cooling medium becomes a ne-
cessity, and. on account of it- small space requirements,
the forced-draft cooling tower is generally the most feas-
ible. Since apparently little is known of the theory in-
volved and also the practical limitations of the problem, it
is the writer's intention to lay down certain principles,
substantiated by accurate experimental data, which will
enable one to choose intelligently between different de-
sign- and estimate the quantities involved.
The physics of water cooling is comparatively simple,
and for present purposes is best illustrated by reference
to Fig. 1, which represents a typical vertical section of
an inclosed tower. Briefly, the operation is as follows:
Hot water enters the tank a, is broken up into streams as
it leaves the distributing troughs at b, and trickles down
through the filling c where it is still further broken up
and comes into contact with the up-going air which enters
at <l. The cooled water is withdrawn from the reservoir e.
Inclosed towers are divided into two classes, forced
and natural draft, according as tin1 air is forced in at d
by fan- or How- in naturally due to the upward chimney
effect when a tall stack is used. The types of towers on
the market are identical with the section given in Fig.
1, the distinguishing feature of different manufacturers
being merely the arrangement of the distributing system
and the kind of tilling used. The following analysis
hold- g I for all types.
Water passing through a cooling tower gives up its heat
in three ways: First, by radiation through the walls of the
tower: second, by direct contact with the up-going air: and
third, by evaporation of a part of the water to be cooled.
The first item is so small as to be well within the errors
of any test and consequently may lie regarded as negligible.
The amount of cooling due to contact with the out-going
air will now be considered. Call this /»,. in B.t.u. per min-
ute. Then
/,1 = TFS (/, - tt);
where
W = Pounds of air passing through per minute :
,s' = Specific heat of air at constant pressure
(i).-.':;:.-.):
I... = Temperature of the outgoing air;
/t = Temperature of the incoming air:
or. a- it will he more convenient to express the air iu
thousands of cubic feet per minute,
h, = qk (t2 - y (l)
Where Q is the quantity of air in thousands of cubic
feet per minute, and the faetor A' represents the amount
of heat required to raise the temperature of 1000 cu.ft.
of air through 1 deg. F.. taking into aceount that as the
temperature rises, a pound of air increases corresponding-
ly in volume. This value is given by the curve marked A".
Fig. 2, and should be taken at the temperature of the out-
going air.
122
]'ii\v e i;
Vol. 41. No. 4
The heat 1"- represented by /<, is between 15 and 20
per cent, of the total cooling, depending on atmospheric
conditions.
Next consider the third item, the amount of heat ab-
stracted by evaporation of part of the entering water.
which represents by far the
greater part of the cooling.
Obviously, since all the heat
lost by the water must be
carried away by the air. the
amount of this evaporation
and consequent cooling will
he limited only by the mois-
ture-carrying capacity of the
air. A cubic foot of air
can contain only a certain
amount of moisture, depend-
ing on its temperature, and
when this maximum condi-
tion obtains, the air is said to
be saturated at that tempera-
ture. When the air actually
contains a smaller amount
than this, then the ratio of
this amount to the maximum
possible amount is called the
relative humidity, expressed
in per cent. When air con-
tains its maximum moisture
at any temperature — that is. the humidity is 100 per
rent. — if the temperature is decreased moisture will be pre-
cipitated; on the other hand, if the temperature is raised,
the air will no longer be saturated but will be capable of ab-
sorbing a certain additional quantity of water vapor. It is
this increasing moisture capacity with increasing tempera-
ture that has made the inclosed cooling tower the most
efficient means of water cooling: in it the air is heated to
the highest possible temperature, approaching that of the
Values of "K7 BAu. per WOO Cu. Ft. Air
£0 !9 18 17 16
•3."
Fig. 1. Diagram of
Typical Cooling
Towei:
^40
Fig. -2.
\ 1/ 1 &-
\ $Pr^'\
\ -^/
\ ^T /
\yS /
/\ Z-
/ >. /
/ V
7_ /_\
I A \
I \
Values of «L", B.+.a per lb. Water
12 3 4 5 6 7
Values of "P',' lb. Wa+er per 1000 Cu. H Air
Values of K. L ami P with Varying
Temperatures
inlet water, and consequently evaporates the maximum
quantity of moisture. The curve marked P. Fig. 2, gives
the vapor-carrying capacity of air in pounds per thousand
cubic feet at 100 per cent, humidity for different tempera-
tures, the moisture content at any other degree of humid-
ity being obtained by taking the corresponding percent-
age of these values.
Atmospheric air entering a cooling tower is rarely
saturated, its degree of humidity being readily obtainable
by taking simultaneous readings with the "wet-and-dry-
bulb" thermometer and referring to tables in any engi-
neering handbook: but as all cooling-tower estimates are
made with direct reference to the humidity and pro-
posals and guarantees are based on this factor, we will
not extend our calculations further than this as a starting
point. Calling the heat lost by evaporation h2 and remem-
bering that all the heat lost by the water is gained by the
air, the general equation of heat transfer in a cooling
tower becomes
H = hl + h2 (2)
where,
// [heat lost by the water) = 8.3 G (T, — 7\) (3)
G being the gallons per minute passing through the tower.
and T2 and Tl the respective temperatures of the incom-
ing and outgoing water.
In order to best illustrate this, the analysis will be ap-
plied to test Xo. 1 in the table of "Tests on a Forced-
draft Cooling Tower." The quantities are: G = 65] :
T2 = 105 deg.: Tx = 84.7 deg. : t, = 90 deg. : t, =
71 deg.: humidity in = 40 per cent.; humidity out =
100 per cent.
Therefore,
H = 8.3 (651 X 50.3) = 110.000 B.t.u. per mm.
The B.t.u. by direct heating will be
fej = QE (90 — Tl)
where Q is the quantity of air in thousands of cubic feet
per minute, and A" is taken at 90 deg.. equal to 17.15 (see
Fig. 2 ) . Therefore,
//, = 17.15 X 19 X Q = 326 Q (4)
The term h2 is obtained as follows: The moisture con-
tent at 71 deg. and 40 per cent, humidity will be 1.16 X
0.40 = 0.464 lb., which is the amount of moisture entering
the tower with every thousand cubic feet of air. On leav-
ing the tower, the entering air will have increased in vol-
ume due to the rise in temperature, so that the quantity
of air leaving per minute will be
where 550 and 531 are the absolute temperatures of the
outgoing and incoming air. The moisture content of
1000 cu.ft. at 90 deg. and 100 per cent, humidity is 2.13
lb., the humidity of the outgoing air always being ap-
proximately 100 per cent, in a properly designed tower.
As there is 1.034 Q thousands of cubic feet leaving the
tower, the moisture carried away by the original air that
entered the tower will be 2.13 X 1-034 Q = 5.205 Q. Sub-
tracting from this the moisture held by the air as it en-
tered, gives
.1/ = 2.025 Q — 0.464 Q = 1.561 Q (5)
which is the amount of moisture actually evaporated from
the water going through the tower, and represents the
quantity of makeup water to be supplied per minute.
In order that water may evaporate, it must absorb
a certain amount of heat per pound evaporated, called
the latent beat of evaporation, the value of which
depends upon the temperature at which evaporation takes
place: this is given by curve L. Fig. 2. As all the mois-
ture is finally heated up to the temperature of the out-
going air, it is correct to use the value of L at this tern-
January 26, 1915
piiwk i:
123
perature. Therefore, the heat absorbed due to evaporation
by the air leaving the tower will be It, = 1.561 Q X 1041
= L628 Q.
Now by equation (2),
If = /,, + h2
Substituting:
110.000 = 326 Q + 1628 0
Q
110,000
1954~
X 1000 = 56,294 cn.fl. per min.
By referring to the test, it will be seen that 53,900 cu.ft.
of air was actually measured by the anemometer, which is
RESULTS OF TESTS ON A FORCED-DRAFT COOLING
TOWER, AVERAGES OF THREE-HOUR READINGS
, — Quantity — ,
Cu.Pt. per Mm.
n
^a
to
n
H3
XX
HO
Kfc
%<
O
B51
105
84.7
110,000
71
40
90
100
53,900
53,000
BSS
107.8
S7.5
108,000
72
(iO
93
100
50,] 00
51,000
i;:is
112
88.5
124,500
««
(ill
9(1
100
51,4110
49,400
fl I ::
108.5
87
115,000
BH
4X
92
100
50,200
49,000
R40
109 9
90.5
103,400
83
48
95
100
50,600
51,800
i;;;-'
11G
98
94,800
43
7 b
101
100
23,500
24,500
630
135
115. S
102,000
00
73
118
100
17,575
18,250
•Natural draft, fan not running.
NOTE — These tests were conducted with utmost regard
as to the accuracy of measurements. The quantities of air
per minute were obtained by anemometers being moved back
and forth across the top of the tower at regular intervals,
and the results were corrected so as to give the actual amount
entering the tower. The water was measured both by a
venturi meter and a calibrated pitot tube.
or about 10.5 gal. per min. of makeup water must be
supplied to compensate for the loss by evaporation.
In order to greatly lessen the foregoing calculations, the
"heat-temperature curves for moist air" (Fig. 3) have
been compiled with special reference to cooling-tower
work. A few remarks on these are necessary. The ordinate's
represent Fahrenheit temperatures and the abscissas total
beat content in B.t.u. per thousand cubic L'eet of air. This
heal content by no means represents an exact "heat po-
tential" at any temperature, and it is only the difference
of any two values which lias a physical meaning. Neither
are tbe (plant ities absolutely correct from a theoretical
standpoint, as certain factors have been omitted to make
the calculation possible; but they will give results which
are correct to within L or 5 per cent., which is close enough
lor this class of work. To illustrate the use of the chart,
again assume the conditions of test No. 1 in the table. As
before, the heat // lost by the water equals 110,000
B.t.u. per min. From the curves the heat content per
thousand cubic feel at 90 deg. and 100 per cent, humidity
is 3350 IJ.t.u. The heat content at 71 deg. and 10 per
cent, humidity is 12 10 B.t.u. Therefore, 33 10 — 1250 =
2090 H.t.ii. is absorbed per thousand cubic feet passing
through the tower, and
(J = , ' — X 1000 = 52,631 cu.ft. of air per min.
2090 j j i
By simply reversing the process, the terminal temperature
may be Found if the quantity of air is known. The column
marked "Quantity Calculated" in the table was figured
140
Relative
\
umi
di+y,
Per
Cent.
4!
i
#„
6<i
'10
0L>
■ no
ioo
130
£
reo
s 110
0)100
/ '/
-
r%
01
% so
0
few
-
I «>
50
40
"//£
W\
c
J'K'I
tie
1 1
-<M
Ml
'•'
IN
I N
,Efl
'vl
HO
NEE
iv:t
:■
G
Fig.
5000 4000 5000 6000
Total Heat Contsnt per 1000
•'!. Heat-Temperature Curve
7000
Cu. r+..
8000
B.+.u.
10,000
for Moist Air
a variation of only 4 per cent., or as close as might be
expected, considering the difficulties involved in this kind
of measurement.
By substitution of Q in ( I ) and (5), we have
A, = 326
liioo
L8,321 B.t.u. per min.
This is 16.7 per cent, of the total 110,000 B.t.u. given
up by the water; that is, approximately 8-'i..'! per cent, of
the cooling is due to -the evaporation effect alone. Also,
^56,200^
liinii
M = 1.561
= S7.5 7S.
from these curves and shows how closely they check with
actual results under a wide variety of conditions.
The maximum temperature of the outgoing air is lim-
ited by the temperature of the incoming water, and from
an examination of curve P, Fig. 2, it is seen that as air
increases in temperature, its water-carrying capacity,
which represents about 85 per cent, of the total cooling,
increases very rapidly. Hue to this enormous increase in
water absorption at the upper part of the temperature
scale, it is evident that the air should leave the tower as
near as possible to the temperature of the inlet water,
and that an exact knowledge of this terminal difference
1:24
POWER
Vol.41. No. 4
is essentia] in figuring the amount of air required for a
given duty. In fact, with other conditions remaining the
same, the ratio of the temperature of the outgoing air
tn that of the incoming water represents the real efficiency
of any cooling tower. A short calculation will bear this
out. Suppose that the air in test No. 1 left at 5 deg. he-
low the incoming water temperature — that is. at 100 deg. :
then.
heat content at 100 deg. and 100 per cent, humidity =
1350 B.t.u.
heat content at 71 deg. and 10 per cent, humidity =
1240 B.t.u.
The difference is 3110 B.t.u. Therefore, the air re-
quired will he
no.ooo = in min
3110
as against 52,631 cu.ft. with 15 deg-. difference. This
means a saving of 34 per cent, in fan power as well as a
much lower air velocity, lessening the tendency to cause
spray, which is sometimes very objectionable, as well as
wasteful. The terminal difference of 15 deg. obtained
in the test is by no means average practice, and the results
are given merely to show the close agreement of theory
and practice in calculating air quantities. In later ex-
periments, made with a view to increasing the efficiency,
the quantity of air was not measured. Just how success-
ful these experiments have been is demonstrated by the
report of a test recently made on a large installation in
the Middle West, consisting of a special Wheeler-Balcke
forced-draft tower. The results were as follows, the read-
ings given being the average of a five-hour test:
WATER
Gal. per min 3200
Temp, in 109 deg.
Temp, out S? deg.
AIR
Temp in 91 deg., 59 per cent, humidity.
Temp, out 106 deg., 100 per cent, humidity.
The noticeable feature of these readings is the small dif-
ference of 3 deg. between the temperatures of the water in
. 106
and the air out, giving a terminal efficiency ol — - = 0i
per cent., which is remarkably high for forced-draft work.
Concerning natural-draft towers, but (rw remarks are
necessary. In general, these will require from four to
live times the ground area taken up by a forced-draft tower
for the same duty, hut where space is available they often
find favor on account of requiring no power fur operation
and needing minimum attention. There are two classes
of these towers, the open and the inclosed types. The
open type is of cheaper construction, without sides, and
admits air throughout its entire height. In the inclosed
tower the air is admitted around the base only, and in its
upward passage it is entirely protected from the cooling
effects of the outside atmosphere. Moreover, due to its
low velocity, the air leaves the tower at the same tem-
perature as the inlet water: in fait, repeated tests have
shown that the terminal efficiency is practically 100 per
rent. In addition to this, the side> give a positive chim-
ney effect, which insures a maximum draft and consequent-
ly minimum space requirements for this type of apparatus.
In the open tower the quantity of air entering at the bot-
tom is necessarily small, due to the absence of draft effect,
and its temperature is prevented from approaching very
.lose to that of the inlet water by a continual inflow of
outside air along its entire height. As these towers or
racks, as they are sometimes called, lack the positive draft
created in an inclosed tower, they are necessarily depend-
ent upon prevailing winds, so that, even in the most ad-
vantageous spots, their operation is not reliable nor uni-
form.
As to guarantees, these usually specify the cooling of a
certain amount of water through a fixed temperature range
under one definite atmospheric condition (usually 75
deg. and 70 per cent, humidity). Prospective buyers often
wish a detailed guarantee for some thirty or forty dif-
ferent conditions of temperature and humidity. This the
manufacturer is unwilling to make, as it means waiting
for payment until all these different weather conditions
happen to prevail. In this connection, the curves of Fig.
:! become useful, especially in a natural-draft system,
where the amount of air is not given. To illustrate, sup-
pose a tower is guaranteed to cool 1000 gal. of water per
minute from 105 to 85 deg.. with the usually assumed air
conditions of 75 deg. and 70 per cent, humidity, and that
it is required to find the cooling under atmospheric condi-
tions of 70 deg. and 50 per cent, humidity. In a natural-
draft tower of the inclosed type, with the conditions of test
Xo. 1. the air would leave at 105 deg. and 100 per cent, hu-
midity. By equation ( '■'* i
// = 8.3 (1000) (105 — 85) = 166,000 B.t.u.
By the curves
heat content at 105 deg. and 100 per cent, humidity =
1850 B.t.u.
heal content at 75 deg. and 70 per cent, humidity =
1800 B.t.u.
Heat taken up within the tower = 4850 — 1800 = 3050
B.t.u. Therefore.
Q = — (10001 = 54,426 cu.ft. per min.
3050 v ' '
With a given load on the condenser, the heat interchange,
the gallons per minute and the cubic feet of air will re-
main the same: namely. 166,000 B.t.u., 1000 gal. per min.
and 51.500 cu.ft. per min. The heat content at 7d
deg. and 50 per cent, humidity i> 1320 B.t.u. Let A'
be the heat content of the outgoing air. then:
166,
X
L320
1 i = 54.420
Therefore.
A" = 4370 B.t.u.
Locating the point 4370 on the 100 per cent, humidity
curve, it will he found to correspond to an air temperature
of 100 deg. This is also the temperature of the inlet
water under the terminal conditions for this type of tower.
By equation (3)
166,000 = 8.3 (1000) (100 — T) :
whence. 7\ = 80 deg. (outlet-water temperature), repre-
senting a total cooling of "20 deg.. the same as in the first
case. This is obvious when it is considered that both the
heat interchange and the gallons per minute remain the
same.
By assuming a terminal difference of from 5 to 10 deg..
the same method may be applied to a forced-draft system.
For Power Plants at Mines when located near the mine
itself an easy and economical method of disposing of the
ash is to arrange a tunnel under the fireboxes, with a slope
of not less than % in. to the foot. Connect this with a bore-
hole and wash the ashes down the latter with mine water,
where they may be used for flushing abandoned workings if
desired. — "Coal Age."
January 26, 1!)1
I' 0 \Y B R
L25
>P<
Jharactteristtics of Direct
By Alan M. Ben.nktt
SYATOPSIS — The factors affecting the speed of
shunt, series and compound motors under differ-
ent conditions of load and lent pert/lure.
Direct-current motors are classified as shunt, series
and compound, depending on the method of field winding
employed. While this classification is generally well
understood, the speed characteristics of these types under
various conditions of load, and while attaining their
working temperatures, are not so well known. As these
characteristics vary greatly in these types, the behavior
of the motor under the above conditions becomes an im-
portant factor in determining its fitness for certain
classes of work.
All motors are supposed to develop their rated speed
at full load after having run a sufficient time to reach
maximum temperature; and when the speed of a motor
is referred to, it is understood to mean that which ob-
tains under these conditions. Variations from the rated
speed occur at two periods in the operation, namely, at
the time when the motor is started cold and at no load
but after the motor has reached its working temperature.
The amount by which the speed under the first con-
dition differs from the rated speed is known as the speed
variation of the motor; it is sometimes spoken of as the
variation from cold to hot. The change from rated speed
under the second condition is known as the regulation of
the motor. In each case the departure from rated speed
is expressed as a percentage of this speed. Both the speed
variation and the regulation may differ in motors of the
same class and rating, these characteristics depending on
design.
In order to determine the changes in speed under the
conditions named it will be necessary to note the changes
which take place in the factors that influence the speed.
It is a characteristic of the electric motor that, under
any condition of load and speed, it takes only the amount
of current necessary to develop the torque required to do
its work at that speed. This it does automatically iu the
following manner :
Any motor when running, by reason of its conductors
cutting flux, must generate a voltage in opposition to that
impressed on the motor terminals, and this will tend to
limit the current which would otherwise pass through the
armature due to its resistance alone. This voltage is
termed the counter electromotive force of the motor, and,
like that generated in any dynamo-electric machine, is
directly proportional to the speed and the flux. For
greater convenience in use, the relation shown by these
factors may be written
e a r.p.m. X <£ (1)
where
e = Counter electromotive force;
4> = Flux.
The above expression may be read: Counter electromotive
force varies as the speed and the flux. The value of e
is always such that the voltage drop in the motor plus e
equals the impressed voltage, or letting / represent the
armature current, // the resistance of the motor windings
and brush contact, and E the impressed voltage; then
e + IR = E, or e = E — IR
Substituting this value of e in equation ( 1 ),
{E — IR) a r.p.m. X <£
which by transposition gives,
E
r.p.m. oc —
in
4>
(2)
This expression, termed the speed equation of the
motor, furnishes a basis for determining changes in the
motor speed under any condition. It will be seen that the
speed varies directly as the impressed voltage minus the
IR drop, and inversely as the flux. Therefore, any con-
dition in the motor operation tending to increase either
the IR drop or the flux lowers its speed. Likewise, a
decrease in either of these factors raises the speed.
Take the case of a shunt motor starting cold and con-
sider the effect of heating on its speed. The voltage on
the field of the motor will be the same as that impressed
on its terminals, and whether the motor is loaded or not,
the field will receive an amount of current depending on
its resistance. This establishes the flux of the motor
and fixes its speed. As the field rises in temperature its
resistance increases and the field current becomes less.
The flux passing through the armature is thus lessened,
and from equation (2) it will be seen that the effect must
he an increase of speed. This condition continues until
the field reaches its final temperature. In commercial
motors the speed increase from this source will vary
From -1 to 8 per cent., depending on the amount of tem-
perature increase and the degree of saturation of the mag-
netic circuit. The higher the saturation is carried, the
less will be the variation in speed.
Temperature increase of the armature affects the speed
slightly by reason of increased IR drop. With the motor
starting under load (here is a certain amount of drop, de-
termined by the motor current and the resistance of the
armature. As the armature heats, this resistance in-
creases and with it the drop. From the speed equation
it will be seen that an increase in IR drop means a de-
crease in speed. The amount of variation from this
source is always small, however, averaging approximately
O.T per cent. While for practical purposes it may be neg-
lected, its effect will be seen to be opposite to that caused
by field heating; that is, it tends to lessen the motor
spied, whereas field heating increases it.
The regulation of the shunt motor, or its change in
speed from full load to no load, while not entirely indej
pendent of field action, is caused chiefly by IR drop. This
drop increases with the load, being the product of the
current taken by the motor and the resistance of the
armature and brush contact. Equation (2) shows that
the effect of increasing the IR drop is to lower the speed
of the motor. Therefore, over the range from no load
to full load the motor will drop in speed. Regulation,
as stated previously, is measured in percentage of full
126
POW E R
Vol. M. No. 1
load speed, and in commercial motors will vary from
I to 6 per cent.
The effect of the field on regulation is caused by arma-
ture reaction. By giving a slight backward shift to the
brushes a certain portion of the armature ampere-turns
are opposed to the field, which is thus weakened, with
the result that the speed is raised. The effect increases
with the load and compensates to a certain extent for
the decrease in speed caused by the //.' drop. This shift-
ing, however, can lie done only within limits determined
by the sparking of the motor.
2200-
\
.1
\
\
->
\
\
\
\
\
\
1900
\
\
— i
V
0) 1800
\o
%,
c
V
V
L
•-
\
i.
0)
v\
V
C
\
D (
o
\
V
o
>
s
"* 1400
-— <
§
a<
'Sjyp
TO
>-
u
\
N
1300-
-T
J.J F
-
r
tges
^
r
-
_.
~~
> ^
C-.
lOOOJ-
c
0
0
>0
40
Amperes
Fig. 1. Speed Curves for 10-Hr. Shunt, Series and
Compound Motors
The regulation of motors is most conveniently rep-
resented by curves, as in Fig. 1. That for a 10-hp. shunt
motor with a 5 per cent, drop in armature winding and
brushes shows a decrease in speed from no load to full
load of approximately 4.5 per cent.
In the case of the series motor, heating does not play
so important a part in its effect on the speed. What va-
riation there is from this source is caused by the IR drop
only. As the motor heats, the resistance of the armature
and series windings increases, and at constant load The
drop increases, with the result that the speed is lowered
This effect is opposite to that in the shunt motor, where
the speed increases with increase of temperature. The
amount of this variation in the ordinary series motor will
approximate 2 per cent., which is small compared to the
.change in speed caused by a change in Load. In the scries
motor a change in load affects the speed both through the
\}\w and the IR drop. The field current is dependent on
the load, being the same as the armature current at all
times. The ilu\ passing through the armature being
subject to the same variation, the effect on the speed can
be seen. Theoretically, the latter would increase from
its rated value at full load to infinity at no load. For
this reason it is not practical to run series motors with-
out some Load in order that they may at all times have a
field on them to prevent excessive speed. This is some
times provided for by winding on a Few shunt turns.
The effect of the IR drop due to change of lead, while
greater in the scries than in the shunt motor — because
there is a drop in the series winding as well as in the ar-
mature and brush contact — will still be small compared
to the change caused by llux variation. For this reason
the speed of the series motor, particularly below the satu-
ration point of the held, will vary almost in exact inverse
ratio with the change in flux and, for all practical pur-
poses, the IR drop need not be taken into account. The
speed curve for a series motor is shown in Fig. 1. For the
sake id' comparison it is made on the basis of the same
armature and strength of field as that id' tin- shunt motor
whose curve is shown in the same figure. The rapid in-
crease in speed as the load decreases will be noted.
Thi' compound motor, having a field composed of shunt
and series windings, partakes somewhat of the character-
istics of both the shunt ami the series motors. The speed
will increase with the heating of the shunt field, as in
the cast' of the shunt-wound machine. Heating of the
armature and series field will cause an increased drop in
those parts, with a consequent lowering of the speed.
However, this drop and the resulting change in speed will
he greater than in the shunt motor on account of the
added resistance of the scries field, the amount depend-
ing on the jDercentage of series windings carried by the
motor.
Regulation will depend both on the II! drop ami the
change in flux due to the action of the series field. Of
these two factors, the latter will have the greater effect.
In fact, in those cases where the series held strength is
in excess of 20 per cent, of the total, the change in llux
will practically determine the regulation. As the per-
centage is increased, the change in speed with the change
of load becomes more pronounced and approaches more
1200
.1100
£1000
^ 900
ID
^800
NOHM/tL SPEED, 400
WXiriUM SPEED, 1200
1
o
■5 700
0
I 600
500
400
300
0
5
\
0
1
5
i
0
2
5
30
Amperes
Speed Cukves fob 7yz-TLp. Interb
Mo'li i i;
the differ-
compound
and there
nearl\ that of the all-series motor. There is
ence, however, that, due to the shunt field, tin
motor is not deprived of all its flux at no load
is not the danger of excessive speed, as in the case of the
scries motor. In Fig. 1 are shown two speed curves of
compound motors, one having 20 per cent, series field,
January 2<i, 1 1* 1 -5
P 0 W E R
12;
and the other fiO per rent. Tn the former the regulation
is as close a< 12 per rent., while in the latter it approaches
very nearly that of the series motor. Both of these curves
are mi the same basis as regards armature and total field
strength, as the curve for the shunt motor.
The compound motor, as generally known, has its ser-
ies field so connected as to strengthen the effect of the
shunt held as the load increases, and thus to gain -nine
of the benefits obtained with the series motor, i tely,
a powerful starting torque and rapid acceleration. By
connecting the series winding so that it opposes the
shunt field, there is had what is known as the differential
motor. This is done to compensate for II! drop fr
no load to full load and render the motor constant in
speed over that range. As the load increases, the flux
established by the shunt field is lessened by the action of
the series, with the result that the speed, instead of fall-
ing off due to the II! drop, is maintained constant. The
differential motor i- not widely used, however, on ac-
motor having a normal speed of inn r.p.m., and a max-
imum of 1200 r.p.m. by means of field control. At the
low speed it will be noted that the regulation is v
1% per cent., the speed being practically constant, while
with a weak field there is an actual increase of speed from
no load to lull load.
m
Powell Aiiaftoina&ftic aimd Oo^alble=
Aiaftotnraaftie Stop Valves
The Powell double-automatic stop valve prevent- steam
from entering a boiler not under pressure from a header.
even should a handwheel be operated for this purpose.
as the valve cannot be opened by hand until pressure is
again raised in the boiler, but it can be closed and screwed
down tight by hand. It also prevents steam from leav-
ing the boiler in case of an accident to the pipe line.
The valve disk is of one piece, top and bottom guided
at A and B, Fig. 1, and has a seat on both sides at C and
QZicHB^O=£>
Fig. I.
Side View of Double
Stop Valve
Pig. 2. End View of Dou-
ble Stop Valve
Fig. 3. Section thkough
Single Disk Valve
count of other features which are a disadvantage, among
these being low starting torque and lack of ability to
stand overloads.
In the three regular types of motors described, it has
been seen that the II! drop causes a falling off in speed
from no load to full load, this being the least in the case
of the shunt motor. Also, up to certain limit- this can be
compensated for by shifting the brushes and getting the
effect of armature reaction on the field. In a motor fitted
with interpoles this same compensation will be noted.
only in a more pronounced degree. The action of the
interpoles has a weakening effect on the main field sim-
ilar to that produced by the armature. The result is an
increase in speed as the load comes on. This action may
even be so exaggerated as to cause a higher speed at full
load than at no load, particularly with adjustable-speed
motors at their weak field points. There is the differ-
ence, however, in the ease of the interpole motor that the
brushes must be kept at the neutral point on the commu-
tator and brush shifting cannot be taken advantage of.
Fig. 2 shows speed curves for a 7^-hp. interpole shunt
IK The disk seats at C should anything happen on the
boiler end and on D if there is any trouble on the main
steam line.
The upper and lower valve seats are of special nickel
composition to resist the corrosive action of the steam.
The fork E is fastened to the balancing lever stem and
holds the valve disk G in position, the weight balancing
the valve disk. The oil dashpot, Fig. 2. the chamber of
which is filled with oil. is to prevent the valve from chat-
tering.
The valve also acts as an automatic equalizing valve
between a battery of boilers and can be used as an ordi-
nary stop valve by screwing down the stem onto the disk.
In the automatic stop valve, Fig. 3, the valve disk //
i< attached to the plunger J. The disk and plunger are
made with but one screw part and are permanently fast-
ened with two sets of screws, making practically one solid
piece, guided at both the upper and the lower end. The
dashpot tits snugly in the valve body. The rim of the
upper part of the disk plunger J i- grooved to work with
a minimum of friction and respond readily to any varia-
L28
TOW EE
Vol. 41, No. 1
tion in the pressure. The dashpol has two vent holes at
the top and two at the bottom, to allow draining any con-
densed water that may collei I therein. As the lift of the
disk is equal to the depth of the dashpot, a full opening
of the valve is insured. The height of lilt is regulated
as desired by raising or lowering the screw stem L.
The seat ring J/ is made with a guide for the lower
pari of the valve disk. When necessary, the -rat can he
readily renewed by inserting a flat tool between the lugs
projecting from the circle and unscrewing. This valve
will' automatically shut off the flow of steam from the
header to the boiler in case a tube should burst. It can
only he opened by the pressure in the hoiler, tint.- act-
ing as an automatic equalizing valve between the battery
of boilers, and also making it impossible to accidentally
turn steam into a boiler when it is being cleaned.
These valves are manufactured by the William Powell
Co., Cincinnati, Ohio.
C©ini€>l©imsgv&i©im aia Moft=IBIlssst
By James D. White
In the design of a hot-blast heating system it is neces-
sary to know the number of pounds of steam required per
minute to heat the specified volume of air through the
desired range in temperature. Multiplying the cubic feel
of air per minute by the weight of one cubic foot by the
specific heat of air and by the temperature rise gives the
number of British thermal units required. Dividing this
product by the latent heat of steam at the average pres-
sure in the heating coils gives the number of pounds of
steam required per minute. Expressing this as a for-
mula :
_ _ CF.M. XH'X S X T
6 -_ L
In which
0 = Condensation in pounds of steam per min-
ute;
C.F.M. = Cubic feel of air per minute passing
through the heater:
W = Weight of one cubic foot of air in pounds ;
S = Specific heat of air;
T = Bise in temperature through the heater:
L = Latent heat of steam.
If steam is purchased Erom an outside source the for-
mula may he used to determine the service to be provided.
If steam is generated in the building it will determine
the boiler-horsepower required, or the pounds of exhaust
steam from the engines or turbines.
The main supply pipe to hot-blast heaters is often
made too small, due to the fact that the actual require-
ments are not carefully considered. A rule of thumb
common among steam fitters is to make the supply pipe
equal in size to that required for direct radiation of five
times the surface contained in the hot-blast heater. Cast-
iron direct radiation for low-pressure steam will trans-
mit about 250 B.t.u. per sq.ft. per hr. On the rule of
thumb basis this would mean a transmission of 1250
B.t.u. per sq.ft. per hr. for the hot-blast heater. This
transmission rate is correct for deep heaters with low ve-
locities over the surface. For shallow heaters or high
velocities this rate may run as high as 2500 B.t.u. per
sq.ft. per hr., showing the error that may be made by the
use of the above rule.
The following values are taken from published data
regarding a well known type of hot-blast heater:
Number of Sections Temperature Rise
4 100
5 116 •
6 129
From an inspection of the above values it will be noted
that nearly one-fourth of the total heat rise i- obtained
in the firsl section of the heater. Since condensation is
directly proportional to heat rise it follows that nearly
one-fourth of the total steam required by a heater will be
i ondensed in the first section.
It is customary to tap all sections of a hot-blast heater
for the same size of pipe, this size be'ng ample for the
Brs1 sei tion of the heater. There appear to be no good
reason for this since a substantial saving could be made
by tapping the sections in proportion to their steam re-
quirements. The amount of condensation as calculated
above is a ho useful in determining the size of steam trap
or pump for returning the water of condensation back
to the boiler.
The standard curves of hot-blast heater manufacturers
are usually based on the heat rise with velocities of air
20 40 60 80 tOO 120
Temperature Rise.Deg.F.
Condensation Curves
measured at a standard temperature of 70 'leg. This tem-
perature of air has been assumed for the volumes of air
as given in the condensation curves presented herewith.
As an example, assume that it is desired to know the
pounds of steam required to heat 40.000 cu.ft. of air per
minute from zero to 100 deg. with steam at 5 lb. pressure.
Starting at the line in the upper left-hand corner of the
diagram corresponding to 40.000, draw a horizontal line
until it intersects the 100-cleg. line. Drop a vertical line
intersecting the steam-pressure curve: then draw a hori-
zontal to the right and find that the condensation is
«4!4 Ht. of steam per minute.
Safety Snpsre.stions — If any employee shows signs of
carelessness, tell him about it. If he persists, report turn.
Otherwise you may be the one to receive an injury through
his negligence. Careless men are a menace to all around
the power station.
Don't forget the other fellow. Careful men are hurt and
killed every hour through the negligence of others. Better
be safe than sorry.
Don't fail to look up occasionally; there is clanger from
above as well as below.
Don't fail to have- any defective tools or equipment re-
paired at once.
Always treat conductors and switches as though they
were alive. — "Acra."
January 26, lf)15
2UIIIIIIIIIIIIIIHII i i iiuiiuiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiiiiiiiniini
POWER 12D
i in 8 mill iiiiiiiiiiiiiin iiiiiiiiii linn iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiini i in limn miiiiiiiiiig
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiini
Large power interests, hiding behind the plea of states*
rights, are attempting to defeat the Ferris water-power
bill by creating a situation that will prevenl the measure
coming to a vote in the Senate before March I. and there
is growing apprehension that the same interests which
have prevented conservation legislation for the last ten
years will still be able this year to keep the natural re-
sources in the public domain out- of use and development.
It is a big game for big stakes that large financial and
political interests are playing. Hydro-electric power is
still in its infancy. Its possibilities are hardly to be con-
jectured. Even under present conditions of development,
there is enough potential water power in the United
States to take the place of the total coal consumption.
In some pails of the country and under some conditions
of construction, production of power from coal entails
a lower installation coi t than hydro-electric production,
even where water power is available. Constantly im-
proving methods of hydro-electric development and im-
proving methods of power transmission, however, make
it impossible for anyone to say what this water power
will be worth or what its development will cost in the
next decade or two. When the diminishing supply and
increasing price of coal are considered, water power
assumes an importance that can hardly be over-estimated.
So far-reaching were the plans and so rapid lias been
the progress of the hydro-electric monopoly that in L913
twenty companies or groups of financial interests, all
more or less closely interrelated, had acquired control
of 2,1 1.0,866 of the 7,000,000 horsepower developed in the
United States, and these same combinations also con-
trolled 3,556,500 undeveloped horsepower. In California
one corporation owns 21' per cent, of the total developed
horsepower in the state, and two groups own 57 per cent.
of the total development; in Oregon 90 per tent, of the
developed horsepower is controlled by these allied groups.
With a few exceptions, the power sites not remaining
in the ownership of the Federal Government have passed
into private ownership in perpetuity. State governments
generally have been notoriously profligate in giving away
public property and franchises for small return or for no
return, and until recent years, generally with no provision
for regulation. In many sections state governments, to
induce development and industries, have made it a rule
not only to give away such valuable public assets, with-
out price or restriction, but also to exempt such grants
or gifts from taxation for a longer or shorter time.
Conservative estimates place the total available water
power in the United States at 25,000,000 horsepower, of
which 7,000,000 horsepower has been developed. Of the
undeveloped water powers, about three-quarters are owned
bv ''Uncle Sam," the power sites being located on public
lands. Control and monopoly of this undeveloped power
.re the stake for winch the big interests are playing.
To prevent more of the remaining water powers being
grabbed by private monopoly through fraud or misrepre-
IIIIIIIIIIIIIIIIIIIIIIIIIIIWI
sentation, the Government several years ago located all
the valuable power sites in the public domain, and the
President withdrew them from entry. Most of them are
still withdrawn. Special interest- protested, but the pre-
vailing public sentiment was in favor of conservation, and
then the interests changed their tune. Now they are all
for states' rights. They are for conservation, and they
are for regulation, but they wan! the Government to
give the lands to the states and let the status do the regu-
lating. The reason is that they can do business more
profitably with state governments, governors, legislatures
and utility commissioners than they can with the Presi-
dent, Cabinet officers, Congress and the Interstate Com-
merce ( lommission.
Secretary Lane, who is a Western man and who wants
to see the resources of the West developed, has been back-
ing legislation to encourage the use of water power and
the mining of coal, oil, phosphates and potash under a
leasing system. President Wilson supports this policy.
The House of Representatives has passed the Adamson and
the Ferris water-power bills, drawn along these lines.
The Ferris bill provides that power sites may be leased
Eor a term of not more than fifty years, with a twenty-
year renewal of the lease at the end of the fifty-year period,
on terms to be fixed by the Secretary of the Interior.
At any time alter the cud of fifty years, the Government
would have the right to take over the power plants by
paying their fair value to the owners, and thereafter to
either operate the plants as government institutions, or lo
sell or lease them to municipalities, states or individuals.
In support of this legislation, the President, Secre-
tary Lane, such conservationists as Gifford Pinchot, and
others have urged that a fifty-year permit would enable
power companies to enlist capital and finance their opera-
tions profitably, giving the communities the advantage of
early development and insuring against monopoly and
extortion, with a reversion of these valuable rights to the
public at the end of the franchise term.
Some of the big power interests have agreed to this
program; others are opposing it, some of them openly,
but more of them under cover. Senators who for years
have been notoriously representative of big interests and
special privileges are opposing the bill. The opposition,
however, is subtle. It is not openly in opposition to lim-
ited franchises or regulation. To defeat the legislation,
the old Civil War issue of states' rights has been dug up.
Corporation lawyers, bankers, politicians and lobbyists are
busy telling the Senate that the public lands, including
the mineral resources and water powers, should be given
to the states in which they are located.
The corporations and the politicians know what the
states have done in the past with their resources and
what they may reasonably be expected to do in the future.
State utility commissions generally have few powers, and
do not exercise them. Some of the Western states have
no utility commissions and have never made any pretense
of regulating anything. Mineral lands, water powers and
similar natural resources belonging to these states have
130
P OWES
Vol. 41, No. 4
often been considered fair loot for anybody who could
get them.
There are votes enough in the Senate to pass the bill
if it can be got to a vote, but the opponents are prepared
i i play all the legislative tricks they know to prevent this.
If they ran stave off a vote until after March 4. the bill
will then be dead, and a new bill will have to be passed
by the House, which means more years of delay and dis-
use for the water power.
;•;
The question of the ultimate advantage of purchasing
i-o.i I on the B.t.u. basis is raised by Mr. Brownell on
page 131 of this issue.
It is true that all of the eoal mined must, or should,
be used as fuel, and if the dealer cannot market inferior
stuff in one place he will send it to some other place.
This is. of course, an unavoidable condition of affairs to
the dealer, and may be entirely satisfactory to the user
so long as he is equipped to handle such fuel economic-
ally; but the purchaser or user should know what he is
paying for or trying to make steam with. The crux
of the whole matter is as the pure-food advocate. Dr.
Wiley, has often said — he has no desire to dictate to or
to prevent any individual from using adulterated food-
stuff, but he does want him to have every opportunity
of knowing what he is using and what the probable ef-
fect will be. Likewise in the use of coal, the consumer
should know as much as possible of the characteristics of
the available fuel supply in order to modify his fnrnace
and equipment to suit the conditions. The total cost
in fuel, labor and upkeep of evaporating water is the
basis of comparison and the final test of the value of
fuels. If the consumer has no alternative he must take
what he can get and make the best of it.
HSoS 5S.w„ peir IBoIIleiF Inloipsepowes'
At a recent lecture by W. A. Blonck, of Chicago,
before the New York Electrical Society, the interesting
information was given out by Mr. Pigott, of the Inter-
borough Rapid Transit Co., that eight boilers of 520 horse-
power each are to serve 30,000-kilowatt turbo-generator
capacity. This gives 7.21 kilowatts per boiler horsepower.
which i- considerably higher than that heretofore
practiced. The Connors Creek station of the Detroit
Edison Co. was designed so that in emergencies 5.65
kilowatts per boiler horsepower might be attained. This
was the highest ratio heretofore.
The statement that so and so many kilowatts of out-
put is obtained from a boiler horsepower does not tell
much about the rating at which the boiler must be run
unless the water rate of the prime mover is given, because
the ratio is dependent both upon boiler rating or capacity
and the steam consumption of the unit or units served
by the boilers. The ratio is, however, an indication of
the advance in boiler practice and turbine economy.
In this respect the Tnterborough's Seventy-fourth
Street plant is interesting. The steam consumption of
the 30,000-kilowatt turbine, served by eight 520-horse-
power boilers, is 11.25 pounds at normal load. This
gives 3.06 kilowatts per boiler horsepower at the normal
rating of the boilers. So at a little over 200 per cent, of
rating these eight boilers carry the load of 30,000
kilowatts, giving 7.21 kilowatts per boiler horsepower.
A statement to us by Mr. Stott, superintendent of motive
power for the Interborough Rapid Transit Co., that there
might be times when it would be necessary to operate
the boilers at 450 per cent, of rating for short period-, as
in emergencies, is of much interest here. A boiler rating
of 450 per cent, is possible, for with a clean and well
designed boiler and furnace, the only limit to capacity
is the amount of fuel that can lie burned on the grate.
As 3.06 kilowatts per boiler horsepower is obtained r.t
200 per cent, of rating, at 450 per cent. 13.8 kilowatts
could be had per boiler horsepower.
James Watt must turn over in his grave at this.
The list of boiler explosions which occurred during the
first half of the year 1914 contains 320 as the total num-
ber. Of the number mentioned in our Jan. 5 issue.
20 are not included, because of denials on further inquiry
that explosions had occurred. It frequently happens that
in reply to our inquiry to the parties concerned a complete
denial is received, but later information verifies the orig-
inal report. This, in some cases, may have been due to
an interpretation of the term "explosion" as a violent dis-
ruption of the body of the vessel used to generate steam.
In general, for the purpose of tabulation the word is taken
to apply to any failure which even temporarily puts the
boiler out of use, including tube, header and blowoff-pipe
failures. The nature of the failure is stated in every case
in which the facts are obtainable. These statements are
not always as full and satisfactory as might be desired.
The greatest number of accidents from any one cause
was due to tube failures, but cast-iron header failures
show an alarmingly increased percentage. When it is
considered that from four to ten or more tubes are con-
nected to a pair of headers and that a number of types of
water-tube boilers in use are not so constructed, the total
header failures compared with tubes is enormous.
Xext in number comes the blowoff pipe. Considering
the severe service and exposure of these pipes it is not
surprising that they should deteriorate rapidly. This
being generally recognized, it is evident that this part
of the boiler should receive more careful and frequent
scrutiny and should be replaced on the first appearance of
weakness or danger. Cast-iron heating or domestic boil-
ers are shown to be frequently neglected and mismanaged.
In view of the damage done (in some cases well up in the
thousands) when one of these boilers explodes, it cannot
be said that they are receiving the inspection and super-
vision they should have. Even kitchen ranges and boilers
have contributed a considerable amount to the total
wreckage. A comparison of the totals for the first half of
1913 with those for the same period in 1914 follows:
Total number of accidents. 261 (1913). against 320
( 1914), with a loss of life of 53 against 120. and injured.
192 against 240. The monetary loss was $193,000 ( L913 i
and $246,000 (1914), respectively, with an average for
those for which estimates were obtainable of approxi-
mately $1330 against $3000. Tube failures appear to
have been more numerous during the year 1913, as 70
are shown, while a year later only 60 are reported.
TTeader failures were only an incident, however, in 1913,
while 30 occurred in 1914. Blowoff accidents stand 13 to
17, and cast-iron heating boilers 33 to 70 for the two
periods, respectively.
January 26, 1915 To WEE
jjniiniiiiiiiini niiiiiiniii muni iiiiiiiiiiiiiuiiiiiiiinii iiiintiiiiui iiiiiiiiiiiiii in iiiiiiiiiiiiiiiiiiiiiiiiiiiiiini
131
i iiiimni mi
©inr
©©imoeini©
=1 II!,::: Ill "'i' I '
Tin' writer recently had occasion to condemn a car of
No. 1 buckwheat coal mi accounl of excessive slate and
screenings. A representative id' the coal company arrived
a lew days later, and upon screening a 50-lb. sample from
the ear he found 12 per cent, rice or barley coal. A 10-
lh. sample showed 1 I per cent. .-late.
The inspector passed the ear. as he said the percentage
was well within the allowance. Upon being pressed for
nine definite understanding as to what we were forced
tn accept, he made the statement that the coal company
allowed itself 15 per cent, screenings and 15 per cent,
slate. He was then asked if his company sold anthrai tte
on a heat-unit basis. He replied that it would not sell
coal on such a contract. Consequently, if the slate test
is the only one which is acceptable, it becomes the test
we are forced to use.
The large consumer situated on a navigable stream or
where he can be served by more than one railroad can buy
his coal on the heat basis, and he has this advantage over
the smaller consumer who can obtain coal from only one
railroad.
After all, does it pay? Is it to the consumer's advan-
tage? Buying coal on a B.t.u. basis resolves itself into a
matter of service. The consume!' pays for that service
whether he, the coal company or some disinterested party
analyzes the coal, and when the cost of this service is put
over against the gain, will not the apparent saving ef-
fected be wiped out?
E. A. Bkownell.
Middletown, N. Y
V
A concrete that could he used successfully as a boiler-
furnace lining would do much to reduce the maintenance
cost of the furnace. The largesl item in furnace main-
tenance is labor, and when the labor is inexperienced,
as when a bricklayer who never laid firebrick is engaged
for the job and insists on laying the brick with a TVin.
joint, the cost of upkeep is indeed high.
A concrete containing limestone would be unfit for
the purpose because limestone calcines at a comparatively
low temperature. The writer's experience with concrete
furnace lining is limited to a test in which two patches
18 in. square were made, one on each side of the fur-
nace, one patch being of slug concrete and the other of
cinders. Neither proved satisfactory, probably because
the concrete was not given sufficient time to set, the boil-
ers being put hack in service within 36 hours.
A concrete that may fulfill the requirements could be
made of portland-cement clinker, graded from line to
coarse so as to make unnecessary the addition of sand.
This concrete should he made with a minimum of water.
Such material is sometimes used as a lining for cement
kilns. Engineers in cement plants may be able to give
some information on the use of clinker concrete in boiler
furnaces.
Could boiler .-citings be made of concrete a great con-
venience would be effected; the two-inch air space is
no longer fashionable, and the form work being simpli-
fied thereby, all the work could be done by the boiler-room
force, thus eliminating the bricklayer.
C. 0. Sandsteom.
Kansas I lity, Mo.
1 have tried several different mixtures of cement and
sand with hard-coal ash, soft-coal ash, tine cinder and salt
for furnace lining, bridge-wall and fire-door arches. A
mixture of one part cement, three parts hard-coal ash, one
part fireclay, one-half as much sand as cement and about
one pei- cent, salt made a bridge-wall that outlasted fire-
brick. For lining, I have been able to get a cement mix-
ture that would outlast a good firebrick lining when prop-
erly laid, if there is time to let the wall harden thoroughly
before it is necessary to start the lire.
The mixture described in Power, Dec. 15, p. 810 —
i.e.. one id' icnient to five of hard-coal ash and one-half
of sand — ought to be good, but I would add about one
per cent, of salt to the mixture. When the wall gets hot
the salt and sand will tend to melt and will fill up the
pores and cracks showing in the cement.
For fire-door arches about the same conditions pre-
vail. One part of cement, one id' sand and five of hard-
coal ash or broken soft-coal cinders or clinkers holds up
better than firebrick set with fireclay. It is necessary,
however, to let the arch have at least four weeks to set
before putting the furnace into operation, and in many
cases this is not possible.
A. A. Blanchard.
Oxford, N. J.
trgvplrnaft© Ie&
Much has been said in Power relative to the use of
graphite in boilers. I first used graphite in a plant hav-
ing four 300-hp. water-tube boilers. No compounds hail
been used in this plant and the tubes were in fair condi-
tion. It required, however, from twelve to fifteen min-
utes to get through a tube with a turbine cleaner, main-
taining ISO lb. water pressure at the turbine, and occa-
sionally we encountered tubes which required twenty to
thirty minutes, but fifteen was a fair average. Before
using graphite we turbined the boilers every ninety days,
and this practice was followed for about nine months
after it bad been in use.
Notwithstanding that the output of the plant was in-
creased more than 30 per cent, during the first nine
months' use of graphite, we were enabled to increase the
continuous runs of the boilers. Records show that two
boilers were operated for L39 and I 13 flays, respectively,
without turbining any of the tubes. Then they were
opened and turbined throughout without difficulty. Fur-
thermore, we were able to get through most of the tubes
in less than eight minutes for each. Graphite did not
show favorable signs until it had been in use more than
132
POW£ B
Vol. 41, No. i
five months and did not get in any good work until we
had used it for about seven months; at this time one
and one-half barrels had been used.
At the end of seven months we began loosening large
- of scale in the steam drums. The writer put two
good men in the drums for over two days, who succeeded
in getting off large quantities of scale which ranged from
Y$ to T% in. thick.
In my next plant I found dirty boilers and lost no time
in ordering a turbine cleaner and a barrel of graphite.
It required more than five months to get the cleaner, and
this gave the graphite a chance to act before its arrival.
I find that graphite will soften incrustation and loosen
the heavy scale in the drums or on the sheets; it is, how-
ever, essential that mechanical methods be employed to
remove the scale.
If maximum results arc to be realized from the use
of graphite, the boilers must be cooled down thoroughly
before they are opened, and the drums must be washed
immediately with a large hose and high water pressure.
The scale will be soft mud when wet, but it will get hard
when it dries.
It is much easier to wash the surfaces and then scrape
them than to allow the accumulation to solidify and
then pound it loose with the peen of a hammer. Do not
take the tube caps or the man-heads off and allow a boiler
to stand over night before washing and turbining. Take
the tube caps off and put the turbine through the tubes
as fast as possible. Then if any scale of consequence still
remains, replace the cutters on the turbine cleaner with
new ones and go through the tubes carefully the next
day.
Waldo Weaver.
Emporia, Kan.
In Oshorn Monnetfs article, "Underfeed Stokers," in
the Dec. 15 issue of Powi-.i;. there is illustrated a "typical
setting of American Stoker" under a return-tubular
boiler. The stoker shown is not the American Stoker,
hut is the Type "D" of the Combustion Engineering
Corporation. This stoker was formerly made by the Amer-
ican Stoker Co., and the drawing from which the illustra-
tion was made is of an installation made by that com-
pany. Mr. Monnetfs assumption was natural, but it is
regretted that he did not have the data on the Type "E"
stoker for his article.
The Type "D" stoker is designed primarily for inter-
nally fired boilers with cylindrical or corrugated furnaces,
but it may be applied to other boilers of 100- and 150-hp.
capacity.
For boilers of 200 lip. and upward, the Type "E"
stoker of the Combustion Engineering Corporation will
effectually prevent smoke at ratings of 150 and 200 per
i-ent. But one retort is installed in furnaces up to 12i/£
it. wide.
The illustration shows a typical setting under a hori-
zontal water-tube boiler. For vertically baffled boilers the
minimum height of setting is ] ft. ('< in. from the floor
line to the header, and on Eastern coal of 16 to 20 per
cent, volatile matter, 50 lb. per sq.ft. of furnace area
may be burned without, smoke. This is equivalent to 175
to 225 per cent, of the boiler rating. For Western coals
of Oil to 10 per cent, volatile matter the height of the set-
ting should be 8 ft. or more for similar results. There
will, of course, be proportionately larger grate surface
for Western coal if high ratings are required.
Operating
When starting fires with a Type "E" stoker, fill the
retort ami over-grates with coal about two inches deep,
throw several shovelfuls of live coal along the retort ami
on the grates and start the blower slowly, increasing the
speed as the coal becomes ignited. As soon as the coal is
well ignited, start the stoker, increasing the coal feed
and the air supply as required.
The fires should not be carried at over 8 to 12 in. in
thickness with coking coal, or i to 8 in. with free-burn-
ing coal. The distribution of coal is uniform, making
it unnecessary to poke, slice or rake the fires. The auto-
Stokeb under a Water-Tube Boiler
matic regulation will take care of any variations in load
between 100 and 200 per cent, of rating.
When ashes have accumulated on the dump trays to
such a depth that the trays will not hold more, they should
be dumped. Slow down the stoker slightly and burn out
all coke on the trays, using forced draft if necessary.
Drop the dump trays and if any clinker has adhered to the
side walls or overhangs the ends of the fire bars it can eas-
ily be removed with a slice bar. Then restore the trays
to the running position and operate the stoker a little
faster than normal for a few moments: then throw in
the automatic. Ashes should be dumped every two to
four hours under ordinary conditions. The ash on the
fire bars should not lie disturbed.
When lianking fires, shut off the air and feed in enough
coal to make the required bank, then close the fire-doors
and damper. If necessary the bank may be replenished
by feeding in more coal.
To start from a banked tire, dump the ash. open the
air gate a very little for a minute, break any large lumps
id' coke and then start the stoker, increasing the coal feed
and air pressure as required. To kill the lire in case of
accident, shut oil' the air. drop the dumps and kxA coal
January 26, 1915
V < ) W E R
133
to maximum capacity. Turn a hose into the ashpit to
quench the live coal dumped.
John Van- Brunt,
Combustion Engineering Corporation.
New York City.
CeEaforaifiiaflgiE P^mps for B©ileir°
IPeedl Service
We have read with interest the extract from a paper
by E. S. Adams, in the Dec. 29 issue, p. 934. Prom our
experience we are inclined to disagree with this statement
which appears on page 935:
While this is especially true with motor-driven pumps, it
also applies to turbine-driven pumps, as a serious overload
(due to the enormously increased capacities which are ob-
tained on some designs of pumps when the pressure is
dropped) sometimes destroys the turbine.
The condition mentioned by Mr. Adams is impossible,
as an overload beyond the designed capacity of the tur-
bine would only cause it to slow down. We would be in-
terested to learn of any turbine-driven installations when:
the action referred to has apparently taken place.
Raines Kessleb,
Terry Steam Turbine Co.
Hartford, Conn.
Tlhacfii Boiler Places
The article by S. F. Jeter in the issue of Dec. 22, p.
884, recalls to the writer a battery of horizontal tubular
boilers in which the plates arc || in. thick (just J.s under
:;, in.). At the girth seams the plates are reduced to
T7;, in. in a way similar to that shown in Fig. 2 in Mr.
Jeter's article, except that in this case, and in fact in all
cases of heavy fire sheets that have come to my notice,
both the inside and the outside plates have been reduced
in the manner shown in Pig. 1 herewith. These boilers
have been in service day and night for 12 years. Stokers
are used and a steam pressure of 145 lb. is carried. The
One Poem Found Satisfactory; the Othek
Questioned
service required of the boilers is much more severe than
in the average plant, yet there has never been a leak or a
lire crack at the girth seams.
Plates r,i| in. thick are the heaviest I have known in an
externally fired boiler, and I have seen them with -j^-in.
plates with the thickness of each plate reduced at the
girth seams to about half the original thickness and none
of them ever developed dejects at this seam.
As .Mr. Jeter points out in his Fie;. I. there is a tend-
ency to crystallize at the calking edge when exposed to
high temperatures. Crystallization of the plate at the
point indicated might result in a fire crack extending
from the edge of the outside sheet to the rivet hole, not
a very serious defect and one easily repaired. In his Fig.
5 lie suggests a method which would no doubt overcome
the tendency to overheat at the edge of the plate, but
which would transfer the crystallization to a point far-
ther back, or about as shown in Fig. 2 herewith. A fire
<rack developing at this point would open into the solid
plate.
Experiment or practice has not yet determined the
heaviest plate practicable in an externally fired boiler.
We do not know, however, that fire sheets y» in. thick
stand up well under heavy firing with two full thicknesses
of plate at the girth -cam and that plates % in. thick
will fire-crack with a double thickness of plate under com-
paratively easy conditions. The limit of thickness at the
girth seam may or may not lie within this range, but
we do know that the girth seam shown in Fig. 1 has
stood up well uniler severe conditions for a number of
years, and the thickness of the joint is less than that
made by two V-r"1- plates, and that the tendency to crys-
tallize at the calked edge due to high temperatures is
less than it would be iii a girth seam with a total thick-
ness of 1 in. through the joint.
Thomas Gbimes.
Houghs Neck, Mass.
The cost of steam regardless of its use is an important
matter to every live engineer. The information on this
.subject which occasionally appears is interesting and
valuable, as it shows us what the other fellow is doing
with his equipment, fuel, etc., and enables us to compare
notes. I think we can stand a generous amount of steam
cost data, but to be of maximum value the reports should
be fully and accurately comparable. Most of them sim-
ply show that A has a small plant ami pays $4 a ton for
coal, and give a figure on the cost of steam per thousand
pounds, based on the cost of labor and coal only.
F> has a different plant, equipped with all of the latest
devices for producing steam cheaply, and is able to buy
and use a low-grade coal which gives an equivalent heat
value. lie therefore produces steam for much less money
than A. which makes A feel like thirty cents when he
sees it. Of course, we care nothing about A's feelings.
Besides, it may wake him up and do him good. There
is doubt, however, whether B has a right to feel so chesty.
We have but part of the actual cost to A and perhaps
less information from B, therefore, a lair comparison is
out of the question.
It may be satisfactory enough to charge only coal and
labor as the cost of steam as a means of comparing dif-
ferent coals, or lor other comparisons within that plant,
but when an attempt is made to get at the actual cost
of steam or compare one plant's results with those of
another, the need of reducing the results to a common
basis is evident. This means a full description of the
equipment, repairs, interest on the investment, insurance,
taxes and depreciation. The cost of operating draft ma-
chinery, stokers, etc.. should be included with the cost of
labor and fuel. Until this is done no one can discus-
relative steam costs intelligently. Any useful informa-
tion is acceptable, but full and exact information is
needed.
H. L. Steong.
Yarmouthville, Maine.
134
POWER
Vol. 41. No. !
SlhadfU CounipMiagf Made aimft© <m
B©M P^aMey
While employed at Fort Yuma Indian School. I needed
a six-inch belt pulley for a wood saw. As some readers
may know, getting such supplies on an Indian reservation
is a long and trying ordeal. Therefore, I used a flange
coupling keyed to the saw mandrel, with thick planks
bolted between and -awed to the same circle as the flanges.
This served the purpose while we sawed 100 cords of
wood for our winter's supply.
J. E. Strother.
Rock Island, 111.
CaiUc^iSgittnirag How ft® C^sft a
Ma,imIh®Se GsisM.eft
The following questions were asked me recently in a
steam-engineer's license examination. I also give my
answers:
Could you cut a manhole gasket if the manhole head
was not convenient to he used and do it correctly?
Yes. if I knew the distance between the two foci id'
the ellipse.
Given the long and the short diameters, how would you
find the distance between the two foci?
Square half the long diameter, from it subtract the
square of half the -hurt diameter: the square root of the
remainder is half the distance between the two foci.
I spent three days hunting for the answer to the last
question, and I found another item that helps to show
why the above answer is true.
To locate the two foci of an ellipse graphically, take
one end of the short diameter as a center and half the
long diameter as a radius and describe arcs intersecting
the long diameter each side of the short diameter. These
points of intersection are the two foci.
F. C. Wires.
Seattle. Wash.
Me\c1haffii©B°^
M. E. Griffin's experience (Power, Dec. 22, p. 889)
with the man who wanted an exceptionally economical en-
gine and finally purchased an old second-hand one reminds
me of some of my own experiences with would-be cheap-
power-plant owners.
A man in southern Florida hired me to install a three
ton ice machine and set up a new ( ?) sawmill. When
I arrived I found an old belted compressor rated at three
ton-, hut which its former owners had never been able to
drive past one ton of ice in ■'. I hours, with a one-ton ca-
pacity brine tank and a cold-storage room taking approx-
imately one ton of refrigeration for '.'I hours, an old in-
ternally fired boiler all pitted and having several soft
patches on it. also an old locomotive-type boiler with an
engine mounted on it.
I set up the outfit, hut refused to run it. and the la -I 1
heard it was still idle because it is cheaper t" buy ice and
pay freight on it than to make it with the outfit. The
sawmill part of the equipment was a little better, and
after getting a new boiler the owner finally did get a man
to run it.
I was engaged another time as a millwright and master
mechanic for a lumber company, the president and su-
perintendent of which were experienced millwrights. The
boiler and engine were too small, so they made up their
minds to install larger ones. I advised them to get a
new boiler and engine and get them from a reliable man-
ufacturer, hut they decided this was too expensive and
finally boughf a second-hand Scotch boiler that had been
run about six months and then replaced by a return-
tubular boiler of the same rated capacity, because the
Scotch boiler would not do the work required.
I begged both the president and the superintendent not
to take the boiler, as it was entirely unsuited to their
work and to the fuel that they must use, and pointed out
other defects, but they got it and the results turned out
as I said; the furnace was too small to burn the fuel, and
after trying several kinds of grates they finally inclosed
the boiler in a brick setting, making virtually a double
furnace. The outfit cost -r'JoO more when finished than
a new return-tubular boiler with a full brick setting
would have cost.
The engine they bought was an old sawmill engine
which had been over twenty years in service and through
two fires. They paid $150 for it and $300 to have it re-
paired. A better engine could have been purchased new
for less than $500, and would have been an engine, not a
junk heap.
Why men will pay good money for worthless piles of
scrap iron in the shape of second-hand engines and boil-
ers I could never understand, for new outfits are always
cheaper in the end.
A. A. Blanchard.
Oxford. X. J.
The editorial on "•Testing Out Automatic Safety De-
vices," in the Dec. 1 issue, reminded me of a plant in
which I was oiler. The engines were cross-compound
Corliss, with the governor on the low-pressure side ami a
safety stop valve in the high-pressure steam pipe, oper-
ated by fly balls on the high pressure side. These fly
balls were called the high-pressure governor by the engi-
neers.
I wanted to knew if, in case of overspeed, the engi-
neer or oiler could operate the valve. I was told yes.
and that the automatic stop could he used instead of the
throttle at shutting-down time.
T suggested that we try it at the first chance, and we
did. Did the automatic safety-device work? Sure it
worked, hut not until we had spent several days scrap-
ing off burned oil and repacking.
G. 1'. ('rain says in the same issue that •"owner- of
larger plants have their boilers insured, which results in
high-grade inspection." I beg to differ. I know of
boilers that were insured and regularly inspected and.
ju-t .-!- regularly reported in good condition; I also
l.ih.u that man] of the tubes were packed solid with scale.
The editorial already mentioned says, "■lie is a wise
engineer who will use those safety device- which lend
themselves to hand as well as automatic control in hand-
ling the machinery which they should safeguard."
He also i- a wise engineer who will inspect his own
boilers, no matter how many inspectors may do it be-
sides.
Chicago, 111. W. II. M u kin,;.
January 36, 1915 1; »> W E R 13!)
pilllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllN i- .!::; - ■.!■..,' r;,:?.' : : ■. ir r r i <i i i jj i in ' T i r r , r n i . ■■ ■■' : ; ■ ' r r-u 1 1 1 1 1 1 1 1 1 1 . r: . :.:^^
Imiqmiriies ©f GeimeraH IiMeresit
ll Illllllllllllll I '. .!'■;!:
Grate Area with Mechanical Stokers — For a given boiler
capacity, why is less grate area required for mechanical
stokers than for hand-fired grates?
H. C.
The motion of the mechanical stoker maintains a cleaner
fire by continuously disturbing the film of ash which is
formed on the burning coal, so that the rate of combustion
is greater per square foot of grate.
Causes of Pump Running Limit — What causes a duplex
pump to run lame — i.e., the strokes on one side are shorter
In length of time than those of the other?
B. L.
The slower-running side may have a leaky steam piston
or the resistances of the water cylinders may be different, as
from a worn pump valve, a leaky water piston or leaky valves
on the quicker-running side or tighter water piston or
stuffing-boxes on the slower-running side. When such faults
have been corrected the lost motion of the steam valves
should be adjusted to obtain the desired equality of strokes.
Using Soilsi Ash for Removal of Scale — Will a boiler be
injured by using soda ash in the following manner? Before
washing the boiler put in about 40 lb. of the soda ash, again
close the boiler, and with the water a little above working
level, boil slowly for a few hours, and after allowing the
boiler to stand for three or four days, wash thoroughly.
R. G. T.
There should be no injurious results if care is taken to
thoroughly wash out all traces of sludge from the try-cock
and water-column connection and the soda solution is not
permitted to enter the safety valve, for upon drying it would
be likely to cement the valve to its seat.
Pipe Sizes for Hot-Water Heating — What is the rule for
determining the sizes of supply and return pipes for a gravity
hot-water heating apparatus with direct radiation?
J. M.
As there is no sensible change in bulk between the sup-
ply and the return water, the supply and return pipes should
be of the same diameter. With ordinary conditions, and
where the supply or return pipe is less than 200 ft. in length,
it is a good practical rule to allow one pipe size greater than
the square root of the number of square feet of radiating
surface, divided by 9 for the first story, by 10 for the second
story, and by 11 for the third story of a building.
Relative Volumes of Water and Steam — What are the rela-
tive volumes of a pound of water at 212 deg. F. and a pound
of steam at atmospheric pressure?
W K
A cubic foot of water at 212 deg. F. weighs 59.833 lb., and
one pound occupies a space of
333
0.0167 en ft
while one pound of dry saturated steam at atmospheric pres-
sure (14.7 lb. per sq.in.) occupies a space of 26.79 cu.ft.,
which is
26.79
= 1604.19 times the space occupied by the water.
0.0167
Indicated, Brake and Friction Horsepower — What is meant
by indicated, brake and friction horsepower of a reciprocating
engine?
S. C. M.
Indicated horsepower (abbreviated i.hp.) is the power
delivered to the piston by the steam or other working fluid
which is employed for moving the piston, and is so called
because the effective pressure is usually determined by use
of a steam-engine indicator. Brake horsepower (abbreviated
b.hp.) is the power delivered by the engine exclusive of the
power wasted in overcoming the friction of its moving parts.
The brake horsepower is therefore always less than the indi-
cated horsepower, the difference being the power required to
overcome the friction of the engine. This difference is some-
times called the friction horsepower.
plunger pump having plungers 5% in. diameter by S in. stroke
and making 28 r.p.m.?
M. M. n.
The cross-sectional area of each plunger would be 6% X
5% X 0.7854 = 23.7"i,s sq.in., and having three plungers, each
with S-in. stroke, the total displacement would be:
23.758 X 8 X 3 = 570.192 cu.in. or
570.192 -^ 231 = 2.468 gal. per rev. or
2.468X28 = 69.1 gal. per min.
The actual amount of water pumped would be less according
to the "slippage," which would depend on the temperature of
the water, height of suction lift, size, design and arrange-
ment of suction and discharge valves and piping, anil adjust-
ment of the plunger packing. Under ordinary conditions the
slippage would amount to about 5 per cent, and the net
pumpage would be 95 per cent, of 69.1 or about 65% gal.
per min.
Racing of Electric Elevator — What would cause an elec-
tric elevator to race occasionally on its upward trip?
J. B.
If the electrical connections are not making good contact
and the shunt field circuit is open, the motor will race, if
compound-wound, or if shunt-wound the fuse will blow. A
ground in the field coils, combined with a ground on some
other part of the system, will also cause high speed. If the
car is over counterweighted it may race on the up travel if
the series field winding is not. cut out of circuit. This is
accomplished when the starting resistance is cut out, conse-
quently it may be that' the rheostat arm has stuck. Again,
the operating mechanism may have drifted back to where it
cut off the current from the motor, but not far enough to
apply the brake. This would cause the car to race on the
up travel without load if the counterweights are heavier than
the car. Also, if the controller has been recently overhauled,
some of the connections may have been misplaced.
Copper-Ball Pyrometer — How is the temperature of gases
escaping from a boiler determined by means of a copper-
ball pyrometer?
R. G.
A copper ball of known weight is suspended in the uptake
at a point where the temperature is to be taken and after the
ball has attained the same temperature as the surrounding
gases it is quickly dropped into a vessel containing a known
weight and temperature of water. The water is rapidly
stirred and its maximum temperature is taken, i.e., when the
ball and water have attained the same temperature. The
temperature of the copper ball before being cooled would
then be given by the formula:
W (T — t)
in which
x — Temperature sought;
W = Weight of the water, in pounds;
w = Weight of the copper ball, in pounds;
t — Initial temperature of the water;
T = Maximum temperature of the water and final tem-
perature of the copper;
S = Specific heat of copper, which may be taken as 0.095.
For example, if the weight of water is 20 lb., the weight
of copper ball 12 lb., the initial teTnperature of the water 52
deg. F. and the maximum temperature of the water and final
temperature of the copper is 85 deg. F., then the temperature
of the copper ball before being cooled would be
20 X (85 — 52)
+ 85 = 663.9 deg. F.
12 X 0.095
The actual temperature of the waste gases will be somewhat
more than the result obtained by use of the formula, on
account of corrections for variations in the specific heat of
the water and metal for different temperatures, losses of
heat by radiation of the metal during transfer from the
uptake to the water, and heat lost during the heating of tin
water and absorbed by the vessel containing it.
Capacity of Triplex Plunger Pump — What is the capacity
in gallons pumped per minute of a single-acting triplex
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses
This is necessary to guarantee the good faith of the communi-
cations and for the irquiries to receive attention. — EDIT! >R ]
136 POWER Vol. II No. I
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiuiiiiiiiiiuiiiiiiiiiiiiiiiiiiiiiiiiiiiiiNiiiiiiNinim iiiiiiiiiiiiiiiiiiiiiiiiiiiNiiii! in ii iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiinniiiiiiiiiiiiiniiiiiiniiin iininiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiini
jmE'iiini<
>rms Sttoadly C©tUllH
III' ' ' :: !■ r:i: ' : " ' .1. Ill .WWIir
A heat engine in an apparatus Eor converting heat
energy into mechanical work. In engines of the internal-
combustion class tin- whole process is carried out within
the self-contained machine to which the name "engine"'
is commonly given. In a steam plant functioning begins
at the heating surface of the boiler (where heat is re-
ceived) and extends to the condenser (where heat is
given up), so that here the term "heal engine" covers a
good deal more than the steam engine or turbine alone.
The efficiency of any energy converter is the ratio of
useful output to total input. There is a class of trans-
formations— typically, those of the electric generator and
motor and of machinery transmitting power — in which
output is, or may be, nearly equal to input. The differ-
ence (decrease) is due to secondary losses, which may be
controlled and diminished, but never wholly eliminated.
However, it is easy to imagine a perfect electro-dynamo,
or a Motionless machine, which shall have no losses and,
therefore, unit efficiency. This ideal action, with the ap-
paratus delivering in useful form all the energy that it
receives, stands as a limit of performance to which the
actual machine approaches more or less closely.
But the heat engine docs not tend to approach unit ef-
ficiency or complete conversion of heat as its action is im-
proved. Instead, there is a limiting efficiency of lower
value, which depends upon the general conditions of oper-
ation and is expressed by a fraction ranging in various
cases from 0.15 to perhaps 0.65. The typical range for
stood steam plants, running condensing, is 0.30 to 0.35 —
this being in terms of heat received by the steam from
the fire and, therefore, not including boiler efficiency.
In other words, an ideally perfect steam-engine plant,
with losses by reason of radiation, cylinder-wall action.
or resistance to flow of steam, could convert into work
30 to 35 per cent, of the heat received, and would un-
avoidably reject in it- exhausj the remaining 70 to 65
per cent. The actual plant will do about two-thirds as
well as the ideal, converting 20 to 2 I per cent.
Having given nothing more than the general law or
principle that energj is convertible from one kind to
ther, one might think thai the conversion, for in-
stance, of heat into work could be effected in a number of
way-, of which the besl or mosl convenient would be
chosen for practical application. Really, however, no
such freedom of choice exists with this particular conver-
sion; rather, there i- but general method available,
that which depends upon the use of an expansive medium,
a vapor or gas. 01 course, attempts have I n made to
find or invent sonic other way. but these have been
altogether fruitless, and the heal engine of common type
is the only known device for getting work from heat.
The question now to be considered is. "How is it that
the heat engine, even under ideal conditions, cannot have
unit efficiency?" The word -bow" is used instead of
"why," of intention. The latter mighi imply that
the question was one to be solved by some train of
ab-tract reasoning based upon an initial concept of the
g( neral nature of energy. On the contrary, there must be
study and analysis of the physical processes involved,
bringing them to expression in simplest terms and leading
to a simple final statement of physical impossibility.
In the manner just indicated let us now consider two
typical heat engines, taking the steam plant with piston
engine ami the gas engine with explosive or Otto cycle
as representative examples. Their cycles of operation,
briefly described in parallel schedules, are as follows:
1 . Taking the charge and bringing it to the state where
it begins t" re, eive heat.
Steam plant: For each working cycle of the engine, a
certain amount of water under atmospheric pressure and
at a temperature not higher than the atmospheric boiling
point is put into the boiler by the feed pump, which per-
forms the work necessary to that end.
( !as engine : A cylinderful of mixed air and gas is drawn
in am! then compressed. In the ideal case the charge
would neither receive nor yield up any heat during this
operation, so that the compression would begin at at-
mospheric temperature and would be truly adiabatic*
2. Imparting heat to the charge.
Steam plant: The water i- lir-t raised to the temper-
ature of -team formation and then vaporized, the lat-
ter effect requiring by far the larger part of the heat sup-
plied. Room for the very great increase of volume from
liquid to vapor is made by the advance of the engine
piston, out to cutoff. The work of this expansion is, of
course, performed usefully upon the piston.
Gas limine: The charge is ignited and its heat of com-
bustion causes a great rise of temperature and pressure,
the volume remaining nearly constant while the pi-ton i-
moving slowly near dead-center.
3. Expansion without heat supply.
Steam plant : . Viler cutoff, the steam expands behind
the advancing piston.
(his engine: This expansion constitutes the whole of
the working stroke.
Tn both cases the ideal condition for besl effecl would
be to have this expansion take place in a cylinder that
was thermally neutral, or that would neither conduct,
absorb, nor eive up heat. The unavoidable departure
from adiabatic action, with real metal cylinders, is one
of the chief causes of the gap between ideal and actual
performance.
I. Exhausl ami removal of unused heat.
Steam plant: Except for a small amount of radiation.
the heat not converted goes out in the exhausl steam.
Whether taken into the atmosphere directly or into a cur-
rent of condensing water, it ultimately settles down to
the general level of outside temperature.
Gas engine: Heat is taken from the cylinder contin-
ually by tin1 jacket water, ami the rest of the unconverted
heat goes out into the atmosphere in the exhaust gases.
The purpose of the preceding brief review of well
^Adiabatic ts :i short equivalent for the phrase, "without
■-■ i\ in; or receiving heat."
January 26, 11)15
I'D W E i;
137
known Facts is to furnish a reason for, and a practical il-
lustration of, the following general statements:
To get work from heat it must be available at some
high temperature, well above thai prevailing in the atmos-
phere ami other surrounding bodies.
This heat is applied to some liquid or gaseous medi
causing it to expand and do work.
When at the end of expansion, which is limited by its
falling to a pressure below which no useful effect can be
got, the medium still contains a large part — commonly
much the larger part — of the beat which it has received.
Nothing can be done with this heat but to reject it to the
atmosphere or surrounding bodies.
All of the work done by the steam or gas in its expan-
sion is not useful output, because the piston must give
back some work in expelling the exhaust or compressing
the new charge.
These statements are more nearly related to the actual
practical engine than to the abstract and, in several re-
spects, imaginary apparatus which is assumed in thermo-
dynamic discussions. They leave some loose ends, but
cover the ground well enough. To sum up, the reason
why the heat engine cannot attain unit efficiency is that
at the end of expansion, when the working medium has
performed all the work of which it is capable, it still
contains a large portion of the original supply of heat,
which has been reduced in temperature and can only lie
given up or thrown away at this low temperature.
In connection with the performance of any heat engine
there are three efficiencies to he considered, which can
most clearly lie delined in relation to an example. The
best test of the Brown-Boveri-Parsons turbine at New-
castle-on-Tyne, which was reported in Power for Apr.
18, 1911, gave the following data and results:
Load. 6251! lew., on a rating of 6000 kw. ; steam pres-
sure, 204 lb. abs. ; steam temperature. 560 deg. F.. or
170 deg. of superheat; exhaust (condenser) pressure.
0.44 lb. abs., corresponding with a steam temperature of
76 deg.; steam consumption, 11. 95 lb. per kw.-hr.
Since one kilowatt-hour is equivalent to 3413 B.t.u.,
the heat energy converted and delivered at the busbars for
each pound of steam is
3412 H- 11.9.5 = 286 B.t.u.
The heat of formation of one pound of steam, assum-
ing Iced water a1 the temperature of the exhaust steam, is
1299 - 11= 1255 B.t.u.
With ideal Rankine-cycle performance, the output per
pound of steam would be 416 B.t.u. converted into work.
Then the ideal efficiency is
lilviil III///)/)/
410
1255
0.332
Heat iiijnif
The actual, absolute efficiency is
Actual output 286
1 2 ~> 5
the ratio of actual t<
Heat in/nit
And the relative efficiency
performance, is either
Art mil efficiency
0.228
0.228
I dnil efficiency 0.332
Actual output 286
= Q.Q&i
,,. = 0.687
Ideal output 416
This ratio is the real criterion of effectiveness, since it
show- how well those losses which are more or less sub-
ject to control are kept down. Of course, the 0.228 and
O.cs; include the combined mechanical and electrical ef-
ficiency of the turbo-generator, which is probably about
0.911. Therefore, the efficiencies in terms of power de-
veloped by the steam on the turbine rotor arc probably
about 0.2 I and 0.72.
A steam boiler with an inoperative safety valve is about
as dangerous as a supply of dynamite. Wagons loaded
with high explosives may be seen any day passing through
the streets of crowded New York. Attention, however,
is drawn to the danger by means of large red letters and
and a red Hag hung conspicuously from the rear of the
vehicle. But boilers carrying high steam pressure and
having plugged safety valves exist under the sidewalks
of this great city without any warning visible to the un-
suspecting pedestrian.
This statement may seem sensational, but it is based
upon fact.
Just recently an insurance company was asked to in-
sure a boiler carrying a pressure of 30 lb. After ex-
amining the boiler the inspector ordered the pressure
reduced to 15 lb., but the owner wanted to carry 30 lb.,
and upon his earnest request the insurance company con-
sented to make a re-examination. When the inspector
arrived he found the safety valve blocked, a stick of wood
having been wedged between the top of the valve lever
and the bottom of the ceiling joist in the building.
X'eedless to say, the insurance was immediately suspended.
Insurance on this boiler would not now be accepted even
after the pressure had been reduced and the safety valve
unlocked.
Fortunately, it is a rare occurrence to find a safety
valve that has been purposely blocked to permit the carry-
in- of higher -team pressure. In fact, the writer knows
of but one other case, and that was done by a negro
fireman who stated that he had to do it to prevent the
safety valve from discharging steam.
Safety valves, however, are often blocked uninten-
tionally or by accident. Not long ago a boiler located
under a Broadway sidewalk at Forty-first St., after
undergoing repairs, was tested by hydrostatic pressure.
To apply this pressure it was necessary to block the safety
valve. The boiler attendant, unaware that the boiler
tester had not removed the block, raised steam on the
boiler. The boiler exploded, badly damaged the sur-
rounding property and fatally injured the son of the
owner.
In another ease the corrugated ceiling over two boilers
sagged to such an extent a- to come into direel contact
with the top of the safety valves. The boilers were located
under the sidewalk of a crowded thoroughfare. Fortunate-
ly, the danger was discovered by an inspector before
explosion occurred.
All but one of the instances here cited occurred in
New York City within the last two or three months.
Considering the vast number of boilers throughout the
United State-, it is reasonable to suppose that a very
considerable number are operated under dangerous con-
ditions.
It is obvious, therefore, that frequent inspections by
trained experts are absolutely necessary. There is
reason for the movement recently inaugurated in so many
states for the adoption of a uniform compulsory boiler-
L38
P 0 W E E
Vol. 41, No. 4
inspection law — a law which will provide for regular
inspections, either by state inspectors or by the inspectors
of boiler-insuring companies duly authorized to insure
boilers in the given state. — Monthly Bulletin of the
Fidelity and Casualty Co.. Jan.. 1915.
w
Hew M^dlffa^ilic VsiEv©
Operators of hydraulic equipment of the double-acting
character have experienced difficulty in obtaining proper
pressure control with their valve equipment when the
mm is forced in both directions by hydraulic pressure.
To meet this demand the Hydraulic Press Manufactur-
ing Co.. Mount Gilead, Ohio, has designed the five-way
high- and low-pressure double-acting balanced poppet
operating valve illustrated herewith.
TO PRESS
CYLINDER N2 |
TO PRESS
CYLINDER NS2
Five-Way High- and Low-Pressube Dovble-
Ai ting Balanced Poppet Operating Valve
The low pressure is admitted tt > the first cylinder, leav-
ing the second cylinder open to the return line. When the
low pressure lias done its work in the first cylinder, the
high pressure is turned on. A check prevents the liquid
from the high-pressure line from flowing into the low-
pressure line. The valve can then be shifted to the po-
sition which applies low pressure to cylinder No. 2 and
releases cylinder No. 1. A similar valve is made with
another position, which applies high pressure to cylinder
No. 2 with No. 1 still open. In most cases the latter po-
sition is not necessary, as the work of cylinder Xo. 2 is
done at low pressure only, as in the case of auxiliary re-
turn cylinders. On account of the length of the operating
lever it is necessary for the operator to stand above the
level upon which the valve rest>.
The valve has five stems and checks and is suitable for
use with pressures up to 5000 lb.
^vjppeaiFarra©© as siEts. 3E31©sna©init be&
By Edwin D. Dreyfus
Doubtless the mentioning of the fact that the appear-
ance of and the general care accorded a power plant or
other operating system possess concrete value will at first
seem commonplace. Everyone will contend that be real-
izes the importance of good order in any working insti-
tution. But do the majority of us take sufficiently ser-
iously the slogan of ""watchful care and attention'' and
make the necessary effort to keep our house in the very
best order both from an interior and an exterior stand-
point? We may neglect the equipment entrusted to our
care so long as no accounting is required, but let the oc-
casion arise and we will quickly find means to do vastly
more than we bad previously attempted. As it is inher-
ent in us to accomplish greater things, why do we not
assume the initiative rather than have the doing of these
things urged upon us ?
A new era has dawned wherein we find ourselves in a
condition of strict regulation, either by keen competition
or else through municipal, state or federal supervision.
The "survival of the fittest'' is going to be more pro-
nouncedly the byword in the future, and it is with this
in view that the writer attempts to point to instances
wherein the orderliness of the plant may represent an in-
direct monetary value of material consequence.
Regulation is the order of the day — mainly that of pub-
lic-service corporations, but to an increasing extent of
industrial companies doing an interstate business as
well — and though there may be other angles by which this
is approached, price or rate control is the one of imme-
diate interest. To determine the proper prices for the
output of any plant, we must fix upon a reasonable return
upon the investment in or the value of the plant. We
ii I not concern ourselves in this article with what this
should be as it is governed by the financial risk. How-
ever, the fair value is another matter, and should not be
a variable quantity, as it is dependent upon the legitimate
investment. The book records of the operating company
should show this, but it is only recently that records have
been kept that exhibit the construction cost separate from
other charges.
Consequently, to derive the value as of a certain date,
an appraisal must he made in the majority of cases. Here-
in lies the tangible value of the general appearance of
the plant, because some courts and commissions hold that
the present value shall be determined by the ''reproduc-
tion cost new less depreciation" method. Evidently, if
the plant gives an impression of neglect, the deterioration
and consequent depreciation may appear more exaggerated
than they actually are. Whatever diminution in value may
result from the inspection (presuming the regulatory
body to lie guided strictly by the investigators report)
will in all probability represent a permanent loss unless
an appeal is made by the company affected.
It is hardly to he disputed that the company's and the
employees' interests are interwoven. If the company
possesses an efficient management the welfare o\' the
aniiary 26, 19 15
POWER
139
employee is enhanced, and if the employees are individ-
ually efficient the company is insured of greater prosper-
ity.
Let us attempt to illustrate the relationship numeric-
ally, taking the power plant as an example. Suppose it
lis to lie appraised for price or rate regulation. Assume
that the normal rated capacity is 1000 kw. and the cost
to install was $100 per kilowatt, or a total of $100,000.
Say where the plant was well maintained the condition
was found to be 8~> per cent, and where indifferent atten-
tion obtained the property was considered to be worth 75
per cent, of its original value of $100,000. Accordingly,
the less industrious engineer would have lost his employer
10 per cent., or $10,000. Now if the company had been
allowed to earn 8 per cent, upon the present value of its
property devoted to public interest and to set aside 5
per cent, to cover necessary renewals and replacements,
together with 1 per cent, for insurance and taxes, it
should receive 1 I per cent, after operating expenses have
been met. Through the writing down of the 10 per cent.
greater depreciation in one ease than in the other the
company's earnings may have been reduced 14 per cent,
of sio.000, or $1400 per year. And this in a larger de-
gree represents the value of the ambitions engineer-in-
charge over the one less energetic.
Volumes have been written upon the different methods
of arriving theoretically at depreciation. During the early
stages of regulation the "life" method principally was
in vogue. Now the theoretical method has substantially
[given way to determining the amount by actual inspec-
tion. Upon this development rests the fact that the plant
appearance, irrespective of the running condition, becomes
of intrinsic value.
By the life, or theoretical, method the depreciation was
arrived at by taking the average length of service obtained
from machinery and property as was shown by a wide
range of experience. Such results had to be predicated
upon the performance of equipment both carefully and
To a great many this discussion may seem mere plati-
tude, but the writer has been in many plants where there
was apparently no appreciation of the value of appear
ances. It is not uncommon to find engineers studying
indicator cards, analyzing flue gases and carefully ob-
serving the genera] load and operating conditions, but
otherwise unmindful of orderliness. The man who not
only secures the lasl fraction of economy and high effi-
ciency but maintains orderly arrangement is going to be
the most highly valued. I have known of two engines
which were both running satisfactorily, but the older one
was the more carefully groomed and was accordingly
marked down for far less depreciation.
In enumerating what could be done in a power plant
to maintain a -nod appearance it might be mentioned
that in boiler settings all cracks should be calked and the
brickwork pointed up; in rotating machinery all side
play and any wabbling due to sprung shafts should be
eliminated, although having no bad effect upon the oper-
ation of the machinery; pumps in the boiler room subject
to accumulation of ash and coal dust caked with grease
should be kept rubbed down ; boiler fronts kept in bright-
ened condition ; water- and steam-pipe leaks stopped even
where they are of trifling consequence from an economical
standpoint; and the tools and all material and supplies
arranged in order.
The old adage that "Cleanliness is next to godliness" is
thereby a virtue growing in significance. It is of course
understood that '"surface'' conditions alone will not be
sufficient, but the internal state of repairs is sometimes
more important. However, it is quite clear that outside
appearances virtually have a tangible value.
HJesvdl=MaEa ISiroI&e
On Monday. Jan. 4, at about 3 p.m., a peculiar accident
occurred at No. 2 pumping plant of the Jamaica Water Supply
Co.. Jamaica, Long Island, N. T. The erection of two new
smoke-stacks had just been completed, and the riggers were
Condition of Stacks Which Fell When Guy. Stub ok Dead-Man Beokb
■arelesslv maintained, and consequently this method
•vorked an injustice in some cases and disproportionately
iavored others. Hence, we have come to employ the
letual inspection by a competent person in virtually all
eceni work.
Inspection to determine the reduction in value, like a
Jteat many other things in our daily life, is not an exact
science, and in this field particularly the psychological
ntluence and mental impression produced may play a
•onsiderable part in the results.
preparing to leave the premises when the guy stub, or dead-
man, broke off near the ground, allowing the stacks to fall
over. The dead-man was a short length of railroad rail, prob-
ably steel, set into the ground. At the point of failure it
showed no bend whatever, but simply a short break.
By prompt and wise action on the part of the chief engi-
neer and the riggers, the service was not interrupted and the
output was but slightly reduced for a short time only. The
rivets were cut at a joint five or six courses from the bottom,
and these short stacks set up in their original places, as shown
in the illustration. By this means the boilers were operated by
forced-draft blowers while the other sections of the stacks
were repaired and made ready to replace.
Although there were several men near-by. no one was hurt.
140
POWER
Vol. 41, No. 4
t=3
5=3
^=3
5=3
■o -a
c 3* c;
E-,5 rj tdi H E C C £ S p hJ
E I * 3 =i ?
.1 S"? S e H M § s *
oJ>^CJ > OOtofe.i-4
J3 o c
0(Z3
: C O C C O C
iOOCC — OMCOOO^
>COO — CCOOWOO©
oC=3
fa
— c <n o c a o o »t <
■CC-CCONOCSOOOOOOOOCSC-lOSOOOOWCOOOOCO
a a a a
— — jz ~
c o o o
#3
j - - - - -
«jl- ?
r- 1
gni 5S-*|
;
2 li |
IcJ
&
fj tf o ^
E E
■3*
5-2
_- .5 a .i.i
I II S3 S 6
c ~ S o £ .-> as >-) »
Water-tube
Water front
Kitchen boi
Caat-iron he
Cast-iron ht
3
Return-tubi
Return-tub
Return-tub
Cast-iron b<
Locomotive
E
E E E
E
a
a e. a
0.
f=J
u
dr°s H
iU-3
,"u
r «
c rr — ~ fe 5
ji g g <■ V2 "jT w = = w s r
■so
O-S
■ a r™ s 5 -a i - a i S 7. t . s § ! a « T < - < < 3 £ 3 3«Ww»aDog°m | £ .
' K ckcz § J l i 3 5 C - < 1 1 i~- I > * 1 1
3 x £ < £ f- C y O Z -7. = < fi U h s H c ~ £ - 5 E- C .3 ~. < j. O 0 d « < 5 m < <c a -
i =
E|
C=3
ot=3
January 26, 1915
P 0 W E K ul
■o2 »
■2 .£ "
£ - 2
b ■so,
a §•
5-9
S = S g -o i gS c 5 3 ; £ g .
OBO
a° 0.5.3
gE o c c © :
= 0000 = !
; - C C C C •
>ooo©=>---;
„ „ _ OMOrtrt<o~ooooooooOooo©o©ooooooooooooooooo<=>oOOOONO
b a.a ,
•J $tJ
< g aH
a bo
r - "2 -2 — 3 - '--_
3 3 3
ill * liS ! fil V? 1! sISll I ills 11.S111Z
I 11 :|3
£ol H $& sooliS 5 HC5 £,3ofc££fc££ a
z
£
1 - Hid* a ul-es.SSld-iS °« ■& lol= HSQg ■* S --^3^-
Id 3 1sbo§! °gjs5fs°1o-<ie »« fi| ^ gojo - g^i gs | a«gM*«
i;i|_=li||^"
> o c ^ -
j p a a a g g
.? r^ r^ rr '.- rr ---. rT. rJL '1. i~ £ 'Z _ ^- — — '— '— U. U. — — — — — ' ' '
[fc.t,£t.tlt-^-t't-^--"
142
powi: b
Vol. 41. No. 1
— -
£ -
\\ Hi I il ?iliJ.li II
JO ;=. £-• so r- H ffl x — x w — — — ~ —
ft I c £ ^ 5 - r _= - = £ > - *r =^EJ'II?- "? *s ^
g ^ o*t ~ - ~ = T E_!l! "~>-H i £ _ S*r*r ^ ^ ■ •
^ooonoooioch
:ccccc=t*cr
III fjijjj |1|||;
iss
s S I 8 5
- >-■; — ffl _.
*&k
'-Z-z -Cs «>oo OK =-C
:i :ii :- ± z. - ^
i s i = s k i i = - -
~
•f
0 =
^C 1
r £
f«c
£
I z X
nt
jer Co.,
- b3 =
§ 5.5 ^w ."
Q ^
Pj
U
d
U ~ =
«
^
c
3s=~ S
6
•6 >
fc
5C - — .^
■8
q
3l4
5^1
gf j<^£z-^-; = j^ ;£i| = ;*i<i;ir-wli=iy:-^r7^--i--:'' ::Cs= wd4w-i i£ii.<^ris^x^.ini.r-s-:-^'
: -z >■ I '^ -r ^ ^ E r: ^"§|i i"r= E"
lISrijlH
;<J J . mZo.oS — ,, Z ■ - ■„' — -z ^ •
= Z 3 .
z 5 = |z
EmHfiiS^BZQZoaljllwSiiaoamH'.Ssi^^
'" '- l- %r %r -^ t- r~ r- (^ r- x ,
:CNSXt*ir= c: c - — "?itSt"iSS^w
January 36, 1915 P01VE R 143
Wsi «3 p b ;:t-=3;33 te 3a aj j;3 = 3jS 333a o 5".S ?;■;?«: ■=''■ = ' > - :
c c '" a *Z Z * ZZ°^,ZS*ZZ ° Z'" sZ Z° ZZ"^ "uus « ""•* °?-c-«^a5pg-c g>,p8,
5-S ► ■n *•" -" 8s •°-D I — — P Pxx I x e xx -px~xxx i; ;ii=; £ x S i: fexxx — £ P o"aX - " 5 t
3=o2 03 3 C 33-£33SS=33 3 3o 33 gsSSSsSJ 33 = *? 3 3— ;:-;;:=:_;:, & " £ 3 fc "^ - i
OhJO JH H iJ E-'E-ffihHt-Hr-H OS E-~ E-t- xHxHHf--; b E-HE-icx b E-U >xHF-S-CO E-OffiH OJ'^C
T3
p3 OCCnCCnCOCCH © © o w O o © © O © O © © C © © O O M •- ©.- © O W C © O — '©©©o — oo©c©oo©o©oo — o~c— ©c — inoc
a c a a
1 •-' gg g H .S 1. .9 h t. g S._o
x % ■g.'C.'C x .£x x "3 xx jIj^Jj x> X' a~^~i^-J XXX "^ ^3 -5 J;,|> X > >X > > !> t.
3 (2 5oo 3 S3 3 t 33 333 o33 >> 3 3 '&-?2g33 33 333 ■? 3x ? « 33— 3i's3.a's s'&s
t> A 1£c i Si i 6 i i i i i.3 i i "O is i -g^ittii lii g ii F x Zig iPgiSB II?
|- I ||g I g| I s || |||J>2S § |o I |3^iSB|| £iS 3 £« || xi'l -££S5| ||f
£ 5 Sjj £ ,3 1 I « II ZZZui* 3 1.3 £ lilolll^ III « l« k£ III l-3,3l«,3 3je
9 99 92 996 99 9 99 9 Bo 9 2 2 2 E 2 g g
rtdsddcidej cj cj d d d d aj § ^oi dojddjic;
©ogoo©oo o©ic©to >o o o oo o © ©. »o — M2
ll]5]5l|l IH5II in flit iiii;i||||i 1| t?l t Jill iKI JiIIj i J " I J H -± llillllllSiS 1 1 "-=5 J t-
qj «cctSNHHHHH ^,-.^.rt-^-HrtrtCKi?!':iri?i:i:i:i- -HH»Hi.:xr-ei- — — .i—^-^.— — — ~h~h — -h.— i— ^ ^i cj c-i c-i ci ci 01 ci ri ri ?i ?i ~i :-: c-t :c :c -i ~i cc re :*: l- c
« hhhM^h^MM^fa^^M^^hh^^'^^MM^t-'iJt;^^^^^'^^^^^^ >- >■ >■ >' c- >- o 'C- 't1 1- >j '£■ i- i- ^ i' >4 i? ^ C' i1 i' >■>■>»'-''>• ^ >•>•>■>> S - e c - ^ ^
>S(D
£?_
^ EhiSJ; u
144 POWER Vol. 41, No. 4
In the deadlock between the President and the Senate over
patronage, waterpower legislation at this session of Congress
seems likely to be lost in the shuffle. States-right senators,
like Smoot of Utah, Borah of Idaho and Clarke of Wyoming,
.2 backed by big water-power interests, are understood to be
g preparing to talk to death the Ferris bill, which has passed
6 3 ■? the House, providing for the leasing of power sites in the
-i -o -g o 3 £ public domain, while the conservationists have declared war
t "o on the Shields bill, reported to the Senate as a substitute for
"ajsJ S -| E tne Adamson general dam bill which passed the House last
"• "- -t % ■§ g]g a a 3 year. The Shields bill is denounced by Gifford Pinchot, pres-
3jkC — >%'S, M -a -a ~t" 2-n-a -otj-o ident of the National Conservation Association, as "the bill
o > — :" ~ 1 ~'~ °_ I 1 = o a j|2 — |r3 of the water-power monopolists."
-1 •§•§■•= S ?l?2; kj a, ■- feS Jj SZ^-""-^ T'-e Adamson bill, which had the indorsement of President
~ &^= ~ ::i- j^ - 3 to ■£ 33 .2 <£- 3 oe <n 3 o=
gp-g s * ** ax ? '8 ** ° o* * o ° J] * ? £ j Wilson, provided for the granting of permits for dams and
d power plants on navigable streams for periods of not more
3 than fifty years, with reversion of the property to the Govern-
ment at the end of that period. The Shields bill, while it
I purports to do this same thing, leaves the way open to endless
-I litigation for determining the fair value of the property
at the end of the franchise term, so that it is declared by
conservationists that it would be practically impossible for
the Government to ever take over the property. Although
the only grant to be made by the Government is for the right
to build a dam and works adjacent to a navigable stream, the
3 language of the Shields bill would require the United States
to take over the entire lighting plant of a city, if it were
-a operated in connection with such power plant, in order to
§ recapture the water power in the stream. The Shields bill
■3 » jf do. 5 d d d also Sives to the water-power interests the right to condemn
3 J -a ,* ji-o-o 5 -° ■" •" land, either public or private, for their own uses, and would
§ § 382 «Js o require the Government, on taking over the plant, to pay
2 s the increased value of land so taken.
2 These features of the bill, which are not the only ones to
fc, a . which the conservationists object, are in direct opposition to
0 =.I ■ ■ - - - o tne P°licies declared for by Secretary Lane, of the Interior
h i §5 3 2 5 5 § Department, and at odds with the principles set forth in the
< ChO Ferris bill for the granting of franchises for power sites
■^ on public lands.
|-j Of the Shields bill, Mr. Pinchot says in his statement:
K There has been no clearer attempt to defeat the conserva-
5 t. tion policy since water power first became a great National
£ — __ problem. It is a direct reversal of the wise and fair provi-
2 $ u v & a «- x sions contained in the Adamson bill as it passed the House.
^ G JZ s- 1- gt; .2 ?■ ~ b President Roosevelt vetoed the James River bill in 1909,
« o '3 a S3 J ? * *S ~3 President Taft vetoed the Coosa River Dam bill in 1911,
S ^ .S'f S.S -° ^s-°>"f £ * ~- > s jj jj-2 because they did not provide for proper payment to the
Q ;S "§ t ■- 3 3 3g3'S« 3 c-j ■£ c 3 3« nublic for value received from the power companies. The
£ i: hoo«hohohmohowoh,
-c^occocc^-c-
l§? S ■?£ i
House of Representatives by an overwhelming vote adopted
the Sherley amendment providing for such payment. The
Sq 5^5 -g dd^go -5 Sg o o ^ ^o Shields bill proposes to give these rights away. It is a
~i-~ ,jP pi ££<S^B £ Oti ~ - > S- surrender to the special interests, and its passage would be
a public calamity.
Q
d Digested by A. L. H. STREET
3 - O .-
"-- mc1.- £ Remedy for Breaoh of Power Contract — According to a
> ,S^ o £ g' decision lately handed down by the Georgia Supreme Court,
h^S'« g _/§ an electric-power company which has an unexpired exclusive
contract to furnish a consumer "with all electricity used by
b-w 2^0 g ^§cUg •gj; J g || ?3-§-|S .-:l£i?*!; 'lim Ior power purposes cannot maintain a suit to enjoin
SZ;Q Ijja'S S &3ls Jfi£ P «ToS^ I l^fe a t- a'tS ^ c-g^ breach of the contract through the consumer's refusal to
d S^">-^-p:^ =^- t- ^ i-S^ ; = ■? ■r:-r.~i'li~ = J& cv's £ -£ =£^I receive further service, where it appears that the company
j3 J-| : l-gl i; = £ f £ tT.i.7 I §i-§||jjj^-g^9§ Sflg g .g-j-g a"S has an adequate remedy by suing for damages for such
T = i? iS jj i E= i J i£~^ vJl^T">^^S3_i-"" i>""i^^-§l breach. (Macon Ry. & Light Co. vs. Palace Amusement Co..
'.--I -1 T li. § !^ :^~^ 5 .S =i :" i 1^ 3 : E^ H'^^ ^J"^cS S3 "Southeastern Reporter," 105.)
Power as Dasis of Mechanic's Lien — The Minnesota Supreme
Court has just been called upon to determine the interesting
question whether one who furnishes fuel and lubricating oils
for the production of power in operating excavating ma-
chinery in constructing a building foundation is entitled to a
-■ lien against the real estate to secure payment for the fuel
and oils on the theory of having contributed toward the im-
provement of the land. (Johnson vs. Starret, 149 "North-
western Reporter," 6.) In answering this question in the
affirmative, the court said: "Had the excavation and removal
of the earth been done by manual labor, the right to a lien
therefor would be undoubted, and we cannot differentiate
^^cnmS^SflSHwSiSlSS-SoSS^ijSmrH-S^S^KOjSGzC^" such a case from one where the same result is reached by
other and modern methods. The value of the defendant's
rt n c"ioiot-o-'C<i<NNNN<siroM-*u3>nco<otob-i-c> property was thereby enhanced, and it can make no difference
, r , , , - — — __ - -. — --, -1 -, -, -, -1 -, -, -1 :i -1 ti -1 -1 :i -i :. n ' , ,1;1 • | his waa accomplished by the use of power obtained
from materials furnished by the lien claimants instead of
by common labor"
Q 333333333333:
January 26, 1915
P 0 W E R
145
TSieirinmodl^iniS\innincs ©f ttlhie MsufimK
Eimg'iime*
By John F. Wentworth
8TN0P8I8 — This paper is intended to present
certain experimental data obtained by the writer
as well as to reintroduce certain old and well es-
tablished facts in a new garb, in order that the oil
engine may be looked at from a reete viewpoint.
The marine plant must be capable of running at full load
with maximum power or of running at partial load with max-
imum efficiency, and most essential at times is the ability to
run at extremely slow speeds. Moreover, to meet all condi-
tions and take its place as a perfect prime mover at sea the
marine oil engine must be capable of being built in large
single units, which means that extreme pressures must be
avoided. Therefore, an attempt will be made to show:
First, that if possible the extreme high pressure of com-
pression must be reduced.
Second, that to give the greatest possible efficiency under
all conditions the proportions of air to fuel must be kept con-
stant regardless of load.
Third, that to get extreme or emergency slow speed the in-
jection of the fuel and the ratio of air to fuel should be varied
contrary to the condition for maximum efficiency.
Fourth, that the percentage of the stroke during which the
fuel valve is held open should be under the control of the
operator in order that injection air losses may be reduced.
Fifth, that by reducing the compression and at the same
time hastening the fuel injection the advantage of the high
compression is not materially impaired.
Sixth, that by reducing the compression it is possible to
obtain substantially the same power with the same theoreti-
cal efficiency, but with an increased mechanical efficiency.
Seventh, that by increasing the temperature of the injec-
tion air a saving of practically 10 per cent, of the fuel now
used may be effected without danger to the plant.
To understand best the effect of the high-pressure of com-
pression and its relation to the cycle, temperature-volume dia-
grams of the oil engine and of other types will be considered.
Fig. 1 shows two typical Diesel diagrams copied from catalogs
of 1S9S and 1913. The end of the expansion stroke corres-
ponds with 100 per cent, volume and the beginning with the
clearance of the engine, making it possible to read pressures
and also percentage volume. Assuming that the compression
is begun with air at 14.7 lb. and 60 deg. F., the specific volume
will be 13.09, and the specific volume at any other point will
be 13.09 times the percentage volume. Thus, from the form-
ula PV = RT, the temperature of the charge can be figured
with a fair degree of accuracy. The constant R for air is
53.22 in English units. By plotting the two indicator diagrams
and figuring a certain number of points the temperature-volume
diagrams were drawn in. It will be noted first that the tem-
perature rises almost vertically during injection. This shows,
comparing the 1898 and the 1913 diagrams, that the trend of
Diesel engine practice approaches the conditions of the gas
engine.
If the Diesel engine can start with a compression of 500
lb., the charge igniting at a temperature around 920 deg. F.,
then after it has been running awhile the temperature at the
end of compression must be around 1450 deg. F. If this be so,
the charge will ignite at any time after the pressure has ex-
ceeded 120 lb., piovided the engine has run long enough to
become normally warm.
This is demonstrated by the diagrams shown in Fig. 2,
which were taken from the writer's experimental engine, al-
though it was not possible to vary the amount of air com-
pressed per stroke as much as desired. Also, the timing of
the fuel valve caused slight trouble. Hence, the fuel valve
was arranged so that the timing of the injection could be
changed, and these diagrams are the result. So far as the
writer knows, this is the first instance in which a timing ar-
rangement has been used on the fuel valve. The ignition of
the fuel was obtained under conditions which were possible
only in an engine which had been run long enough to get
'Excerpts from a paper read at the recent meeting of the
Society of Naval Architects and Marine Engineers, at New
warmed up. and it seems a fair assumption that, if the fuel
ignited as shown, it would have ignited if the clearance had
been so increased that these low pressures were obtained at
the end of compression. The fuel is shown igniting at from
70 lb. up to full compression pressure. Diagram No. 6, "where
the ignition was at 130 lb., makes it apparent that much
energy is lost by radiation during the time of high pressure
and high temperature. This loss at the end of compression
should be somewhat reduced in the low-pressure type, for al-
though the cylinder volume at the end of compression might
be doubled, the radiating surface would be only slightly in-
creased.
Next consider the proposition that the ratio of air to fuel
be kept constant. This has been done on the best gas en-
gines as a means of governing, but it has not been done on
the Diesel, because apparently the full amount of air must be
compressed per stroke in order that the ignition temperature
may be obtained. In the Mar. 11, 1913. issue of "Power" the
writer brought this out, proposing that if only two-thirds of
the fuel were used, only two-thirds of the regular amount
of air should be compressed. Moreover, if the friction loss
is a function of the unit pressure on the piston, then the
friction of the Diesel at two-thirds load would be 50 per cent,
greater than in the proposed form of governing. This can be
stated in another way: namely, the friction is not a percentage
of the net load, but is a percentage of the work done in the
0 10 20 30 40 50 60 70 80 90 100
Compression or Expansion in Percentage of Original Volume
Pig. 1. Temperature- Volume Curves
cylinder, regardless of whether the effect is plus or minus on
the brake.
Fig. 3 is a set of curves constructed from tests made by
Professor Denton in 1898 on a small Diesel engine. Improve-
ments have been made in the engine, but the cycle is un-
changed, so that results obtained in these early tests are at
least indicative of what goes on in the present engines. This
diagram shows that the friction is practically constant at all
loads and would seem to bear out the contention that the fric-
tion is toll taken out of both the compression and the work-
ing strokes. With the compression pressure constant the sum
of the compression work and expansion work would vary but
little for a wide variation in the net work done in the cylinder.
However, the sum of the compression and the expansion
strokes would vary greatly if the compression pressure was
decreased.
Air is compressed and then expanded. The air in itself
does nothing. All the work put into compression will be
given up in expansion except the losses. If the quantity used
per stroke is reduced, the losses per stroke will be diminished
by this same amount. Unnecessary compression of air is an
extravagance, therefore, for it is needless to compress more
than is required for the proper combustion of the fuel.
Next, consider the problem of extremely slow speed. In
order to reduce to a very slow speed care must be taken to
obtain a maximum temperature at the end of the compression
stroke. Diagram No. 6, Fig. 2, shows the effect of cooling
146
row e i;
Vol. 41. No. 4
at the end of compression. For moderate speeds with a fall-
ing horsepower the amount of air compressed per stroke can
be varied. Under present conditions there is a limit to the
speed of the oil engine, at which limit the ignition will be un-
certain. To go beyond this in the present engines the air
should be heated before it enters the cylinder and the tem-
perature of the jacket water should be raised. It might even
be wise in an emergency to cut out the circulating water en-
tirely.
Need for this slow speed was painfully evident when the
Diesel-engined ship "Christian X" fell in with a disabled ship
in midocean. It was stated at the time that tow lines were
repeatedly passed to the disabled ship only to part. Pre-
sumably the best that could be done would have been to keep
starting and stopping the engines in the hope of gradually
accelerating the tow to the point where the line would stand
the lowest possible speed of the engine.
A steam vessel under the same conditions would have run
her engine very slowly, just enough to give steerage way,
until she had taken up the slack of the tow line, and then
would have increased the revolutions gradually until the de-
sired speed was obtained. This is manifestly impossible in the
present oil engine. In the plant proposed at the end of this
paper the motive power would be steam and the engine would
start at a few turns per minute with steam from the econo-
mizer boilers.
At this point it may not be out of place to call attention
that extreme pressure may be avoided. If the fuel be injected
rapidly and timed for the end of high compression, results
are to be expected similar to those shown in diagram No. 8,
Fig. 2.
High compression means small clearance and a relatively
large number of expansions, which is desirable, but the full
effect is lost through the slow fuel injection. Why this is so
is shown in Fig. 4. Assume the indicator diagram to be di-
vided into four similar ones by means of the adiabatic lines
shown. Each may be considered separately. In the case of D
the average clearance is 16.1 per cent, of the whole cylinder
contents, hence it has only 6.2 expansions. Diagram A, on the
other hand, has 11.34 expansions. If the fuel be injected
rapidly into a cylinder whose clearance gives a compression
pressure of 275 lb., then the number of expansions will be 8,
or the same as the average of this Diesel diagram.
Attention will now be directed to some of the benefits to
be derived from reduced compression. In the engineering
press the idea of reducing the compression pressure and at
the same time making up for this lower compression tem-
perature by means of a higher temperature of the incoming
air has been opposed, the objection being that the volumetric
efficiency would be decreased; in other words, the power of the
cylinder would be reduced, making the engine more bulky.
The original idea was to save fuel by a process similar to com-
pounding; that is, when only a partial load was called for, a
partial cylinderful of air would be compressed. If this were
A } -Total Horsepower in Fuel
B- Indicated Horsepower
C- Jacket loss (Horsepower)
D- Exhaust Losslrlcrsepower)
E'Friction Loss\riorsepoweri
F- Compressor (Horsepower)
Fig. 2.
Diagrams Takex ox Experi-
mental Engine
Brake Horsepower
FIG.3.
Pig. :i.
Variation of Losses with Differ-
ent Loads
to the fact that the cylinders of a Diesel engine should be
kept as hot as possible, up to the point of encountering lubri-
cating troubles. This is true whether extremely slow speed
or maximum efficiency is required.
Passing to a discussion of the advantages of fuel valve
control as to timing, etc., in the present oil engine the dura-
tion of the fuel injection does not take into account the
amount of fuel to be fed nor the speed. If an engine be
slowed down to half speed, considerably less fuel will be used
than when running at full speed. Xotwithstanding this, the
fuel valve is open for the same length of time. This results
in a waste of injection air, the thermodynamics of which will
be taken up later. If the fuel be injected early in the stroke,
a rise in pressure can be obtained which will increase the
efficiency. If the fuel be fed into the cylinder a considerable
time after the end of the compression stroke, it is possible to
produce the same result that is obtained in the explosion en-
gine by retarding the spark. Thus, it seems to be highly de-
sirable to be able to control at will both the timing of the
injection and the duration of the fuel feed.
The method of compensating the theoretical loss en-
countered in reducing the compression pressure next calls for
consideration.
If the compression pressure is reduced, the fuel injection
can be hastened and combustion completed earlier in the
stroke. If high compression is used, then the fuel must be
slowly injected, as is now done in the Diesel engine in order
done by closing the admission valve at the middle of the suc-
tion stroke, a vacuum would be formed in the cylinder dur-
ing the rest of the stroke which would be maintained during
the first half of the compression stroke. In this case volu-
metric efficiency will not suffer, whereas in the present method
of governing the engine at partial loads the efficiency is hand-
icapped by the presence of an unnecessary excess of air.
The economy possible in the injection air is the last point
for discussion pertaining to the present type of engine.
From the best information available the injection air
compressor must develop about 10 per cent, of the brake
horsepower of the main engine. Of this 10 per cent., what care
has been used to maintain an economical cycle? The air is
compressed in two or more stages to 1000 lb„ and then cooled
to the original temperature or lower. The total energy in
the air after it has been compressed to 1000 lb. and cooled to
its original temperature is exactly what it was in the be-
ginning. All that the work of compression has done is to
make a part of this original energy available. Our natural
conception of the energy of compressed air would lead to the
consideration that the energy depended upon the pressure of
the air; as a matter of fact, the determining factor is not
pressure, but temperature. There are several simple proofs
for this statement. One is: 'Tsoenergic lines are lines rep-
resenting changes during which the intrinsic energy remains
constant. It will be seen later that the isoenergic and isother-
mal lines for a gas are the same" (Peabody). When the air
January '.'<>, 1915
r U W E I!
147
is cooled to the original temperature after having been com-
pressed, it is brought back to the isothermal from which com-
pression started.
This contention can be proved mathematically. The form-
ula for work of expansion to the absolute zero of temperature
and pressure is
W = PV -=- (k — 1)
This formula considers a fixed quantity of air — that is. a
certain weight. In the formula PV =RT, considering the same
weight of air, P and V will be the same as in the formula for
work. By substitution, the formula for work can be re-
written W = RT -f- (k — 1), where R and k are constants, and
the only variable in the formula is T, the absolute tempera-
ture. This new formula will give the work of expansion for
one pound of gas.
The above consideration of the injection air is simply to
bring home the fact that a waste is being made of one-half
of the available energy of the compressed air when this air
is cooled to room temperature in place of being used at about
5S0 deg. F. If the injection air is used at this temperature,
just one-half of the fuel to run the air compressor will be
saved, and there will be no difference in the operation of the
engine. Before this can be wisely done, however, there is
need for redesigning of the fuel valve. It is the writer's opin-
ion that the valve should be simplified even if the pump is
complicated.
In regard to the danger in using air of this temperature
there is this to say: Any explosion in the injection line will
come from a quick opening of the air valve. If there is a
pocket in the line where oil can settle and the air valve is
suddently opened with no pressure in the line, the body of oil
will be dislodged from its pocket and shoved along ahead of
the incoming high-pressure air, compressing the low-pressure
20 30 40 50 60 70 80 90 I0Q
Volume, Per Cent.
Fig. 4. Showing Effect of Slow Fuel Injection
air. If this action in the injection line takes place quickly,
the body of oil will take the place of a piston and the action
in the injection line will be the same as in the cylinder dur-
ing the compression stroke. A temperature of ignition will
be reached in the injection line regardless of the temperature
of the injection air. In fact explosion is caused not by the
injection air, but by the contents of the air line when the
high-pressure air is turned on. It is possible to safeguard
this type of engine from explosion in the injection line by a
little care in the design of the piping arrangement, etc., and
the exercise of due caution in operation.
The present instructions for the operation of Diesel engines
state that the cooling water from the jacket of the fuel valve
should be cold to the hand. The writer feels that the fuel
valve can be designed so that it needs no jacket whatever.
This may be objected to as an unsupported opinion, but it is
based upon years of study along this line of work during
which nothing has been found to oppose this idea and every-
thing points to its possibility.
In closing, the writer's proposed thermo plant will be con-
sidered. Briefy stated, the starting medium is steam, gen-
erated in a special boiler. Before starting, the steam is ad-
mitted to the jackets of the engine, warming it to a point
where starting steam can be used without excessive con-
densation. After the engine is running on oil the flow through
the jackets is reversed, water from the bottom of the boiler
enters the bottom of the jacket, and a mixture of steam
and water comes from the top and is returned to the boiler.
In this case combustion in the cylinder will not increase the
temperature of the jacket water, but will transform it from
water to steam at the same temperature. Also, the exhaust
gases from the engine will pass around and through this boiler
1C 2^ C: ~ ?1~ C-IC
O JS -. ° -* M3 ° °
8« 2 =
D O -TO O 0
o o o o o
JO © O OS 00
3a © O O © O O
g^ WX MX WM ©x ox eoc
©— © O — C — ou
©r-s ©^ ©,-
2x 2^ «« 9n O- ©Q
o
So
"T
gc
So
s1
T
§?
ST
s?
c ■
8?
8f
i
© ■
s<~
ST
If
"
T
© ■
71-
ST
lT
8?
t
© •
2f
ST
0 ■
c 1
?
o -
*f
8?
0 •
8?
?
If
3f
ST
1T
8f
T
© •
1T
st
© -
§t
8f
ea -s
Sg ™g Sw. g° S2 2?
£0 in9 00^ «" t- m g_
&& S" S- 39 2W S10 3'
go So So" go 00 gc
sd So 8" S"" 80 sc
"T raT So °° M ci
go |o 00 go go go
g"? SB"? 8™ 2™ 2™ 8"
-HO O© X © o© Z-.© ^©
ow »w o« 2M ^M ©M
5© 00 CO© 00 ^© £©
OW Q0O OM OM g« §«
i?d 00 x© o© 2® ^©
<© 5o
f o 00 x © 00
= s.
fetD fcbfl fa* Stf fc W &, M fjcj I
3.D TJJD T3J tJ$ T$JQ -n-Q
«© SO
Sco ©C
Om © co
2© £©
tfo o© xo o© ^o n©
o„ o
2© 2
°ro 0L
2© i£"
fe bo fa tc t, a fc. tc fa tc fa ;
3£ T3J3 -o^j -§jD -BJ3
Our"
.
flT-
-
a»
tioj
Q-m
Q-m
°,t»
Q.n
da;
E§
6S
as
as
- ;
S ?
nil
r--
i-~
1-:-
H-
HP<
E-a,
~-
hi
HPh
Hi-
HO.
— —fees
S S & o o
§ 9 8
5 5 fe o o &
148
POWER
Vol. 41, No. 4
before being: rejected, and as much as possible of this waste
heat will be converted into steam. The energy from the boiler
will be used to run the auxiliaries and, if the idea is correct,
to run a separate steam propelling plant. The exhaust from
all steam units "will be returned to a condenser, where at last
the remaining heat units will be abandoned as unavailable
energy.
JOSEPH G. McC< 'LI.U.M
Joseph Grant McCollum, superintendent of construction of
the Essex power station of the Public Service Electric Co., at
Point-no-Point, on the Passaic River, died from pneumonia at
the Newark (X. J.) Private Hospital, Jan. 13. at the age
of 29.
He was graduated from Cornell University in the class of
i909. He was for a time with Westinghouse Church Kerr &
Co. in New York, and early in 1914 removed to Newark. N. J.,
and became superintendent of construction at Burlington for
the Public Service Electric Co. of New Jersey.
F. W. JENKINS
On Thursday, Jan. 14. 1915. Frank William Jenkins died at his
home in Brooklyn, N. Y., from complications due to old age.
He was widely known as an expert in hydraulics and "was con-
nected with the Henry R. Worthingtpn Pump Co. for over
fifty years.
Mr. Jenkins was born in Hudson. N. Y., Feb. 26, 1832,
moved to Brooklyn at the age of 14, and spent the remainder
of his life there. Many inventions and improvements in steam
pumps and hydraulic engineering are the products of his
genius. He also occupied a high place in the civic and munic-
ipal life of the comunity in which he lived. Two daughters
survive him.
William Naylor. after a service of 44 years in the engi-
neering department of Marshall Field & Co.. has retired from
his position as chief engineer. He was born in Lancashire,
England, Jan. 4, 1S33, was apprenticed at the age of 9 to the
London & North Western R.R. shops at Leeds, and was pro-
moted to engine runner at the age of 19. In 1859 he was driv-
ing the "Manchester-Liverpool Flyer." which occupation he
left to come to America, arriving at New Orleans after a
voyag-e of seven weeks. He worked at New Orleans, Jackson
and Memphis for short periods and in 1S60 settled in Mt. Car-
mel, 111., and engaged in the lumber-sawing business. He
moved to Warrensburg, Mo., in 1865, and in 1866 to Chicago,
where he entered the employ of Field, Leiter & Co., now
Marshall Field & Co., in 1871. He is father of Past-President
Chas. Naylor, of the N. A. S. E.. of which organization he is
himself an active member, being treasurer of the Robert Ful-
ton Association No. 28, of Illinois, and is known to, and es-
teemed by, almost everyone in Chicago who is in any way con-
nected with power-plant engineering.
OIL I1-^; ITS SUPPLY. COMPOSITION AND APPLICATION
By Edward Butler. Published by Charles Griffin & Co.,
Ltd., London, and J. B. Lippincott Co.. Philadelphia, 191 1.
.size 5x7% in.; 32S pages; illustrated.
After introductory chapters on the origin, production and
economic aspects of oil fuel, the author reviews some of the
early work with oil fuel, compares the steam-, air- and pres-
sure-jet methods and then proceeds to descriptions of the
burners in use today for steam boiler furnaces. Oil fuel for
marine and locomotive purposes is dealt with at length and
its use in metallurgical work is also considered. Very wisely,
it would seem, no attempt has been made to touch upon trie
internal combustion engine, as this subject is so broad in it-
self that any treatment in a book of this kind would neces-
sarily be incomplete.
THE ANALYSIS OP COAL WITH PHEXOL AS A SOLVENT
By S. W. fair and H. F. Hadley, Bulletin No. 76 of the
* niversity of Illinois. Paper; size, 6x9 in.: 41 pages, il-
lustrated. Price, 25c.
As far back as 1851, experiments were made on coal for
the purpose of dissolving those constituents of the coal which
were soluble in certain chemicals, and from time to time dif-
f. i tut investigators have taken up the problem. The ex-
periments by the authors of this bulletin have been made for
the purpose of overcoming some of the objections to both the
chemical and the proximate analysis.
It will be understood that the action of the chemical —
phenol in this case — must be that of a true solvent and must
not cause chemical changes either in its own structure or in
that of the components of the coal. While there are several
chemicals that will dissolve the solvent components of coal,
phenol is best.
It does not seem that this method of coal analysis will be
adopted generally in power plants, but our readers who are
interested in that subject will find this bulletin well worth
while.
STEAM CHARTS. By F. O. Ellenwood, Assistant Professor of
Heat Power Engineering, Cornell University. Published
by John Wiley & Sons. New York. Cloth, 7x9?., in.. 91
pages; IS charts; 9 figures. Price, SI.
This book is intended to be of assistance to engineers and
students when making calculations involving wet or super-
heated steam, and for that purpose the author has presented a
set of charts convenient to handle and easy to read without
extending the size of the charts beyond the dimensions of
the page.
An introductory chapter sets forth the fundamental princi-
ples of pressure-volume and temperature-entropy diagrams,
and another chapter is devoted to describing the preparation
and use of the steam charts and a table of velocities, the scale
of volumes being plotted from the values given by the steam
tables of Marks and Davis.
A third introductory chapter defines atmospheric pressure
and Baumetric corrections. There are an index chart, total,
heat volume chart, external-work-volume chart, correction of
mercury column for temperature and chart of correction of
barometric readings due to change in elevation. There are
also tables of correction of barometric readings and for cap-
illarity, and tables of density of mercury and of theoretical
velocities of steam expanding adiabatically in a frictionless
nozzle.
Fifty illustrative problems are given with their solutions.
These, together with the greater convenience of the charts
over the large scale folders such as are usually employed for
steam charts, render the task of making steam computation
more inviting to the beginner and provide a "work well
adapted to the purposes of a handbook for engineers for data
on the properties of steam and for checking methods of per-
forming computations.
BUREAU OF STANDARDS PUBLICATIONS
Three instructive papers have recently been issued by the
Bureau of Standards under title of "Measurement of Standards
of Radiation in Absolute Value," "Various Modifications of
Bismuth-Silver Thermopiles Having a Continuous Absorbing
Surface," and "An Experimental Study of the Koepsel Perme-
ameter." the last being an instrument for measuring the
magnetic properties of iron and steel.
iOOES IRECEEVEB
AMERICAN HANDBOOK FOR ELECTRICAL ENGINEERS.
By Harold Pender. John Wiley & Sons. Inc.. New York.
Morocco leather; 2023 pages, 4%x7 in.; fully illustrated;
tables. Price, $5.
MACHINE SHOP PRACTICE. By Wm. J. Kaup. John Wiley
& Sons, Inc., New York. Cloth: 199 pages, 5i4x734 in.;
15S illustrations. Price, $1.25.
HOW TO RUN AND INSTALL GASOLINE ENGINES. By C.
Von Culin. Norman W. Henley Publishing Co.. New
York. Paper; 9S pages. 3*4x6 in.: illustrated. Price. 25
cents.
INSTALLING EFFICIENCY METHODS. By C. E. Knoeppel.
The "Engineering Magazine," New York. Cloth: 258
pages, 7x1014 in.; 103 illustrations. Price, S3.
Burd High Compression Ring Co., Rockford. 111. Directory
of piston ring sizes. Illustrated. 6S pp., 4%x6% in.
Elliott Co., 6910 Susquehanna St.. Pittsburgh. Penn. Bul-
letin H. Alarm water columns. Illustrated. S pp., 7x10 in.
Harrison Safety Boiler Works. Philadelphia, Penn. Cata-
log No. 601. Cochrane multiport valves. Illustrated, 72 pp.,
6x9 in.
Chicago Pneumatic Tool Co., Fisher Building. Chicago, 111.
Bulletin No. 34-K. Fuel oil and gas driven compressors. Il-
lustrated, 24 pp.. 6x9 in.
General Electric Co.. Schenectad\ . X. Y. Bulletin No. 42.010.
Small turbo-generator sets. Illustrated. 14 pp.. 8x10% in.
Bulletin No. 42.300. Steam engine-driven generating sets. Il-
lustrated. 12 pp., 8x10% in. Bulletin Xo. 45,602. Lightning ar-
resters for series lighting circuits. Illustrated, S pp., 8x10%
^m^.
POWER
,«#»»""»,,,
Vol. II
NEW YORK, FEBRUARY 2, L915
No. 5
By R. T. Strohm
THE boss was good and
proper mad, of that there
was no doubt,
When he came in the
other week to see the engineer.
He hardly got inside the door be-
fore we heard him shout
"Just look at this report on cost
of power for the year!
The way you're running up ex-
pense has simply got to stop,
Or you'll be gallivanting 'round in
search of pastures new.
Another year like this one was will
make us close the shop.
Get busy, now, and find the leak
— the thing is up to you!"
THE engineer was young and
fresh, an overbearing snob,
Who always tried to make us feel
that he was mighty wise;
So when we heard the sudden news
that he might lose his job,
We nudged each other in the ribs
and slyly winked our eyes.
For we were in the boiler room, to
cart and heave the coal,
To clean the tubes and haul the
ash, and tend the water, too;
And every mother's son of us, deep
in his inmost soul,
Felt pretty sure that half the
heat was going up the flue.
HE snooped around in even-
nook and tested all the traps.
To see that they were work-
ing well and steam could not
get by;
He tinkered with the bearings and
adjusted all the caps,
Believing that the friction loss
was running rather high ;
'Half the heal was going up the flue"
He packed the engines and the
pumps to make them good and
tight,
And then relined the shafting till
it ran exactly true;
But we that fed the furnaces from
early morn to night
Were puzzled why he never
thought to test for CO z.
HE ponshed all the pieces of his
indicator kit
And took a set of cards from
every engine on the floor;
He looked them over carefully and
set the valves a bit,
And then he fixed the rig again
and took a dozen more;
He overhauled the coverings on
pipes conveying steam,
And every broken section was
replaced at once with new;
He tried to lower running costs by
every kind of scheme,
But never thought to make a test
of what went up the flue.
HE fussed and fumed and
stewed around about a week
or so,
But still the coal-pile dwindled
down alarmingly each day;
So finally we told him what we
thought he'd like to know,
And said he'd better find just
how much heat we threw away.
That hint was what he needed, for,
instead of cutting loose,
He clinched his job still tighter,
and he saved our bacon, too.
And thus he proved the adage that
it's precious little use
To save around the engine while
you're wasting up the flue.
150
p o w E i;
Vol. 11. X,
^jiiniicipal Ptunffinpimig Stotliomis ©f
Detooit
By Thomas Wilson
SYNOPSIS — Development of water-works from
one unit in 1876 lii li'ii units at present date, hav-
ing a combined capacity of 267,000,000 gal. in .",
hr. New station containing three units just com-
pleted. Operating data and costs for the past year.
Foi 38 years Detroit's water-pumping station has been
located in Waterworks Park ai the eastern extremity of
the city, between Jefferson Ave. and the river. Starting
with one unit, the development to present capacity has
been interesting. New units were installed as required
until seven are now contained in the old station and three
m a new building in which space lias been provided for
a total of six. Individually, each unit shows an increased
duty over its predecessor, and collectively, the entire in-
stallation indicates the development in the art.
In the installation of large units Detroit has been a
pioneer in pumping engines as well as in boilers, and it
may be of interest to follow the plant through from the
beginning. In 1876 a building large enough for two
units was erected, and the first unit, a compound beam
double-acting pumping engine having a capacity of 24,-
000,000 gal. per -2 1 hr.. was installed. The cylinder di-
mensions were 42 and 84 by 40% by 72 in. In those
days a compound engine was a novelty, and as the unit
bad almosl double the capacity of any pump then in exist-
ence, it created wide interest and, like the Centennial
engine, was one of the attractions in the engineering
world. It showed a duty of 87,000,000 ft.-lb. on 100 lb.
of coal, the steam pressure being 65 lb. gage and the
speed 10% r.p.m. It was the only pump of the kind ever
built by the Detroit Locomotive Works. That it was of
good design and well made is shown by the fact that it is
still in active service.
A unit of similar design and of equal capacity and duty
was installed in 1880. The dimensions were 40 anil 84
by 11 by 72 in. Six years later another unit was re-
quired and the east end of the station was enlarged to
make room for it. At this time Detroit's original pump-
ing station was dismantled and as many parts as possible
were saved for the new unit, which was to have a capacity
of 30,000,000 gal. The pump thus had a capacity 25
per cent, greater than its predecessors, and was one of
the "giants" of its day. It had compound steam cylin-
ders and a water plunger of the same diameters as unit
Xo. V. but the stroke was 84 in. and the speed higher.
The economy was also greater, as the pump showed a duty
.if 100,000,000 ft.-lb. In 1898 the high-pressure end was
ivd signed for a 35-in. high-pressure cylinder, so that the
pump could utilize steam at 135 lb. pressure instead of 65
lb., the pressure formerly carried.
After an interval of seven years increasing demands
called for a fourth unit, which was put in service m 1893.
The west cud .if the station was enlarged to receive it.
The pump was tbi' first triple-expansion unit for the sta-
tion, with cylinders 28, is and ! I l>\ -"ai by 60 in. It had
a capacity of 24,000,000 gal. and was a duplicate of one
pumping engine installed in Milwaukee and three in
Chicago at the same time. Outside-packed plungers were
another departure. A 30-day test by Professor Harms
on this unit showed a duty of about 130,000,0Q0 ft.-lb..
an increase in economy of 33t<3 per cent, over the mosl
efficient of the compounds which had been previously in-
stalled.
Up to this time the pumps had been working against a
head of 140 ft., or GO lb. Need was felt for a higher pres-
sure, so the next units were designed to operate against a
bead of 230 ft., or nearly loo lb. pressure. The east end
of the station was again enlarged, this time for three
units. In 1900 two 25,000,000-gal. pumps were installed.
They were triple-expansion units, 34, 62 and 92 by 36%
by 72 in., which on test showed a duty of 148,000,000
ft.-lb. These two units, as well as Xos. 3 and 4. operate
on 135-lb. steam pressure. All up to this point had been
equipped with jet condensers giving a vacuum of 26 in.,
the air pump being driven from the main shaft.
Fig. 1.
New Pumping Station in Watebwohks Pake,
Detuoit
Eleven years passed before the seventh unit was
needed. It was ordered hi 1011 and was built and in-
stalled in the remarkable time of eight months after the
contract was signed. The capacity was 25,000,000 gal.
and the type vertical triple-expansion as before. The
dimensions were 32, 60 and 9o by 37% by G6 in. Since
the last previous installation a surface condenser in the
suction of the pump had become common practice, and
was used in the present case. A surface of 2000 sq.ft.
exposed to all of the water passing to the pump produced
a vacuum of 28 in. and helped to boost the duty of this
unit to 150,000,000 ft.-lb. and cut the steam consumption
to 10.3 lb. per i.hp.-hr. This arrangement naturally
eliminated the circulating pump.
Boileb Room
Tn the boiler room equal progress was made in the size
and efficiency of the equipment. Old firebox marine and
return-tubular boilers, hand-fired, have been replaced
with water-tube boilers of horizontal and vertical types
equipped with top feed or underfeed stokers. There is
now a total of 15 boilers aggregating 1399 hp. There are
four 225-hp. horizontal boilers on which the pressure has
been cut to 1 1 * > lb., three 333-hp., four 225-hp. and four
eimiarv 6,
PO w E i;
i:.l
100-hp. vertical boilers, all carrying a working pressure
of 165 lb. The 400-b.p. boilers were installed in 1913.
Each has 4000 sq.ft. of heating surface and 64 (later re-
duced in 50) sq.ft. of inclined urate surface. The high
ratio of 80 to 1 was made possible by the excellent quality
of coal used, which is Meadow Brook run-of-mine averag-
ing 1 1,300 B.t.u. per lb. and 6 to 7 per cent. ash. Pour
brick stacks for the L5 boilers supply natural draft.
a common header tapped to each boiler. Feed water regu-
lators control the supply to the boilers, and as the pumps
ate in unison with the main units, safety valves are
installed on the d i «£ to prevent excessive pres-
sure and allow surplus water to flow back to the botwell.
Feed-water heaters are no! used, as there is qo auxiliary
steam. This completes the equipment of the old station,
which was given in some detail so thai it might be known
Fig. 2. Thkee 30,000,000-Gal. Pumping Engines Occupying Half the Station
Gages to measure the draft, a steam-flow meter and a
C02 recorder make it possible to check results obtained
Erom the boilers.
Fuel is obtained by boat during the aavigation season.
It is unloaded into a lumper, crushed, and conveyed to
storage shed- of 12,000 tons capacity. Industrial ears
carry the coal into the hoiler room where, with the excep-
tion of the new boilers, it is shoveled into the magazines
of the stokers. For the late addition a half-ton air hoist
transfers the coal from car to stoker.
Water from the jet condensers and the .-team jackets of
the engine cylinders i.s discharged to hotwells at a temper-
ature of 110 deg. and fed to the boilers by single-acting
pumps operated from the walking beams or the main
shafts of the first six units. The pumps discharge into
from what type of machines the operating data presented
later were obtained.
New Pumping Station
In 1909 the water commission broke ground for the
new station which rapidly increasing demands made
ssary. The building, which has just heen completed,
was planned for six unit-, being 300 ft. long and 75 ft.
wnli". It i- one of the finest structure- of its kind in the
country. Concrete foundations, walls of cut stone and
pressed brick, a marble entrance, large bronze doors, elec-
troplated railings anmnd the pits, massive lighting fix-
tures, -late and terrazo floors and white enamel brick
walls in the basement are some of the features which
helped to make the building cost half a million dollars.
152
P 0 W E E
Vol. 11, No. 5
Fig. 3. Foub 100-IIf. Vektical Water-Tube Boilers Installed in 1913
Three of the six units for this building have just been
erected and put into service. All are triple-expansion en-
gines of 30,000,000-gal. capacity, with cylinders 32, 60
and 90 by 39% by 66 in. The pumps are of the double-
flow type and each has on the suction side a condenser
having 2000 sq.ft. of surface. Hydraulic-ally operated
gate valves 48 in. in diameter are fitted to the suction
and discharge pipes. Each pump weighs approximately
900 tons, of which 70 tons is accounted for by two 20-ft.
flywheels. The hollow steel shaft is 22 in. in diameter.
A feature is the making of the water ends entirely of casi
steel. Extra strength was required, as the water is de-
livered directly to the mains, with no intervening reser-
voirs. No official tests have been conducted, but the duty
guaranteed on 1000 lb. of saturated steam is 172,000,000
It. -II)., and 180,000,000 ft. -II.. is expected by the builder.
The cost of the pumping equipment was close to
per million gallons of daily capacity.
No. Equipment
i Pumping engine
1 Pumping engine
1 Pumping engine
1 Pumping engine
2 Pumping engines
Kind
Compound, beam.
Compound, beam.
Compound, beam ,
Triple expansion . .
Triple expansion . .
1 Pumping engine Triple expansion .
3 Pumping engines Triple expansii
t'. Ccidensers. . Jet. -
i> Air pumps... . 3 single-acting,
4 Condensers. . . . Surface.
PRINCIPAL EQUIPMENT OF DETROIT WATER-WORKS
Size Use < rperating Conditions
12x84x40Jx72-in Main unit Steam pressure 65 lb .. '•
16x84x41x72-in Main unit Steam pressure 65 lb., head 60 lb.
:;.">\--l\n\s4-in Main unit Steam pressure 135 1b., head 60 lb.
2Sl I8x74x36x60-in. . Main unit Steam pressure 1351b, head 601b.
34x62x92x36}x72-in. Main unit Steam pressure 135 lb., head
1001b
32x60x90x371x66-in. Main unit Steam pressure 165 lb., head
100 1b
32xfiOx90x39ix66-m. Main unit Steam pressure 165 lb., head
1001b
Serving main units. . 26-in.vaeuum
Varying siz> ■- Serving jet condensers Direet-eonneeted — Speeds- 12 to
21 r.p.m
Serving main units 2s-in. vacuum.
6 Pumps Single-acting.. Varying sizes Boilerfeed Mechanically driven by main
3 Boilers Vertical water-tube 333 hp. . Generate steam .. . Steam pressure 165 lb. stokers
3 Stokers. tones underfeed ■>, rving 333-hp. boilers
4 Boilers Wood type 225 hp Generate steam . Steam pressure 111* lb., stokers
4 Stokers Top feed.., Serving wood boiler-
4 Boilers Vertical water-tube 225 hp Generate steam. . . . Steam pressure 165 lb., stokers
4 Stokers Top feed Serving 225-np. boilers
4 Boilers Vertical water-tube 400 hp Generate st. -am Steam pressure 165 lb., stokers
t Stokers T..p feed 50 sq.ft. grate s, rving 400-hp. boilers
1 Airhoist Monorail Serving 400-hp. boilers
2 Cranes Traveling. 30 and In new and old stations
Maker
Detroit Locomotive Wurks
Riveiside Engine Works
Riverside Engine Works
E. P. Allis & Co.
Allis-Chalmers Co.
Allis-Chalmers Co.
Bethlehem Steel Co.
Same as pumping engines
Same as pumping engines
3 Bethlehem engines — Worthington eon-
denser; 1 Holly engine — Holly con-
denser
Same as main units
Wickes Boili
Under-Feed Stoker Co. of America
Wiekes Boiler Co.
Murphy Iron Works
Wickes Boiler Co.
Murphy Iron Works
Wiekes Boiler Co.
Detroit Stoker Co.
Detroit Mad irn .\ Hoist Co
Northern Engineering Works
February 3, 1915
PO W E l:
153
Although an independent boiler room and eoal-storing
sheds are contemplated for the new station, at present
steam is supplied from the boiler room of the older plant,
the new 400-hp. boilers giving ample capacity; a total
of 1399 boiler-horsepower in 15 boilers supplying 10
pumping engines having a combined capacity of £67,000,-
niiii gal. in -.' I hr. against a varying head running up to
100 lb. Tims, for a million gallons in 24 hr., 16.5 boiler-
horsepower has been provided. Working on 8-hr> shifts,
65 men are employed for both stations.
( IpERATING 1 >ATA
Data available from the Board of Water Commissioners
lor the year ended June 30, 191 1, arc presented in the fol-
lowing: For the year the total water consumption was
10,724,947,672 gal. pumped to an estimated population
of 652,000 against an average head of 53.2 lb. This re-
duces to an average daily consumption of 111,575,200 gal.
ami an average daily per capita of 171.4 gal. < >f the total.
11,257,814,355 gal. was pumped on the high service
against an average dynamic head of 63.7 lb., and on the
low service 29,467,133,317 gal. against an average head
of 47.4 lh. On Feb. 13, the maximum day, the pumpage
was 145,607,536 gal., and on Dee. 25, the minimum day,
85,187,023 gal. For the high service the average daily
was 30,843,321 gal. and for the low service 80,731,872 gal.
Each unit is equipped with a Venturi meter, which, on
an average, reads to within 5 per cent, of the pump dis-
placement. In the above figures an allowance of 6 per
cent, slip was made for the three compounds and
triple-expansion engine and 5 per cent, on the other units.
During the (rear 16,874,865 lb. of Meadowbrook bitu-
minous run-of-mine coal was burned. Including unload-
ing from the boats, the price averaged $2,515 per ton.
Per pound of coal 869 gal. was pumped against an aver-
age head of 53.2 lb. or 123.1! ft. The average duty per
100 lb. of coal was 88,906,868 ft. -lb. The pumping cost
Cost of PUMPING BASED on station- expenses
Coat per
Amount Cost per Mil. Gal.
Item per Tear Mil. Gal. Raised 100 Ft.
Payroll $67,533.31 $1.66 $1.36
Fuel 59,103.57 1.45 1.18
Oil and waste 1,448.76 0.04 0.03
Supplies and repairs .... 1,359.97 0.11 0.09
Miscellaneous 3,556.77 0.08 0.0T
Totals $136,000.38 $3.34 $2.72
based on station expenses is given in the accompanying
table. The total for the year is $136, 1.38. Tin- re-
duces io $2.72 per million gallons raised 100 ft. Figure I
on total maintenance, the cost per million gallons was
$6.23.
Smith. Ilinchman & Grylls, of Detroit, were the archi-
tects and engineers for the new station. Theodore A.
Leisen is general superintendent of the Hoard of Water
Commissioners and II. W. Gould engineer-in-charge -
the pumping station. To both of these officials we arc in-
debted for the information contained in this article.
TSue Coimsttaimft-C^riFejnift TFS\3msfoirinmeir
By John A. Randolph
SYNOPXIX — Principles and construction of the
constant-current transformer, with a diagram of
Us connection in arc-light circuits.
On all series arc systems it is important that the cur-
rent be maintained constant irrespective of how many
lights may be turned on or off. This is accomplished on
direct-current systems by varying the voltage of a special
generator assigned to each circuit. However, on alter-
nating-current systems the arc lines are generally con-
nected to busbars supplying other circuits, hence the
maintenance of the constant current must be accomplished
without affecting the generator pressure on the busbars.
To secure this result, a special form of transformer is
used. It is similar to the ordinary static transformer, the
principal difference being that one of its sets of coils is
movable.
Construction
The general construction is shown in Fig. 1. The
transformer contains two coils, a primary and a second-
ary, one of which (in this case the primary I is station-
ary, the other being movable. The coils encircle the mid-
dle leg of a laminated iron core of the double magnetic-
circuit type, the length of the core being sufficient to
allow the secondary to mow up and down through the
required range. The secondary is suspended on either
side from a rocker-arm attached to a shaft, which in
turn is connected at its middle point to another arm ex-
tending oppositely to the other arms and which carries an
adjustable weight. An oil-filled dashpot is also attached
to the shaft for the purpose of steadying the movements
of the shaft and it- accessories.
Operation
In analyzing the operation, consider two simple closed
coils of wire /' and S placed side by side with axes coin-
cident, as shown in Fig. 'I. If a current is passed through
£
■7=-^-
■Secondary
Primary
Zh
Fig. 1.
Showing General Construction
STANT-CUKRENT TkANSFORM EB
IF CON-
coil P, it will produce a magnetic field which will ex-
pand with the rise of the current. As these lines of force
move outward they will be cut by the coil S. Xow, ac-
cording to th«' laws of electromagnetic induction, this
1 54
vow e i;
Vol. n. Xo. r,
cutting of lines of force will induce a current in the coil
S, the direction of which will lie opposite to that in coil P .
This induced current will m turn set up a magnetic field
of its own. but it will be opposite in polarity to that of
coil /'. owing to the opposite direction of the respective
currents. A magnetic repulsion will therefore ensue be-
tween coils P and S. Tins action has been summarized
in Lenz's law as follows: "In all cases of electromagnetic
induction the reaction of the induced current is such as
to tend to stop the motion which produces it.'' It is
Pig. 2. Illustrating Principle of the
Constant-Current Transformee
upon this principle that the operation of the constant-
current transformer depends.
The counterweight in the two-coil type, shown in Pig.
1, is adjusted to exactly balance the weight of the sec-
ondary coil minus the repulsion, thereby rendering the
transformer sensitive in its action and overcoming to a
large extent the attraction of the force of gravity on the
coil. The secondary coil is connected directly to the out-
going arc lines and the primary to the busbars. It can
be said in general that the repulsion between the primary
and the secondary will vary with the current in the lat-
ter. If. with the secondary coil in a given position, an
additional number of lamps is turned on. the added scr-
ies resistance will at once reduce the current for that par-
ticular instant. This will result in a decrease of the re-
action of the secondary upon the primary, thereby allow-
ing the secondary to fall nearer the primary, where the
stronger field will induce the extra pressure necessary for
maintaining a constant current in the secondary. The
turning oil' of lamps will cause an instantaneous increase
in the secondary current, which will increase the repulsion
and cause the secondary to move to a weaker field, where
the voltage will be lowered sufficiently to prevent any rise
of current in the lamps that remain burning.
It will he observed in Fig. 1 that the arc on the end of
the rocker-arm which carries the counterweight is adjust-
able. This is for the purpose of compensating for the
difference in field strength in the various positions id' the
secondary. For instance, in a strong portion of the held,
the difference between the weight of the secondary and
the force of repulsion i- less than in a weaker part of
the lichl. Therefore, unless the counterweight were ad-
justed to balance this added weight in the weaker field, a
stronger current would he neeessarj in the secondary to
shift the latter to a position of equilibrium than would
he required in the stronger field. The constancy of the
current in the arc circuit would therefore he destroyed.
However, by the adjustment of the arc from which the
counterweight is suspended, the latter is caused to pull
more heavily on the secondary in the weaker parts of the
field, thereby enabling the secondary to maintain a con-
stant-current value.
Three-Coil Type
As the capacity of the transformer increases, the num-
ber of ampere-turns in the primary and. the secondary
must also increase. Therefore, if only two coils were
used, this would result in bulky windings and accessories
which it would he difficult to handle and which would be
likely, on account of their inertia, to lack the proper sen-
sitiveness in operation. To obviate these difficulties three
or four coils are used instead of two. In the three-coil
type one primary and two secondaries are used, as in
Fin. :!. Large pulleys are used instead of levers for the
chain connections to the counterweights. The prima r\
is stationary and is placed between the two secondaries,
which are movable. Each secondary has two pulleys and
a counterweight of its own ami is entirely independent of
the other in its action. Therefore, the repulsion and the
distance between coil <Sj and the primary may he widely
different from that between coil S2 and the primary. Arc
circuits may therefore be operated on the two coils in en-
lire independence of each other. To increase the current
in coil Nj, the external resistance remaining the same,
the weight IF, is reduced, allowing the coil by means of
gravity to move nearer the primary. On the other hand.
to increase the current in coil S... the counterweight W2
must be increased in order to overcome the force of grav-
ity and raise the coil t" a position nearer the primary.
Pour-Coil Tx m:
In this transformer the primary ami secondary are
each composed of two coils, both coils of one set. cither
Dashpot
Fii,. :'.. Three-Coil Type
primary or secondary, being movable. In Pig. 1 is
shown thi' arrangement of coils where the secondary is
movable. The two primary coils arc fixed at the extrem-
ities of the middle leg of the laminated iron core, the sec-
ondaries being free to move up and down in the inter-
vening space. A repulsion between the primary and the
secondary causes the two coils of the latter element to
February 2, 1915
POWE It
155
move toward the center of the core, thereby approaching
each other. The movable coils arc balanced against one
another on two double lexers, A and B. one end of lever A
being connected to coil >', and the other to coil 82. Like-
wise, lever B is connected to the other bides of coils >\
For opening and closing the primary circuit, either
plug switches or oil switches may lie used, hut il i.; com-
mon practice to use the latter because of greater conven-
ience in operation and the fact that they will open auto-
matically if a sudden abnormal load is thrown on the
Fig. 4. Arrangement of Potjh-Coil Type with
Movable Secondaeies
Fig. 5. Casing of Air-
cooled tl; insformer
and S.„ With this arrangement the secondaries will
exactly balance each other when no external force is ap-
plied. This equilibrium, however, is destroyed as soon
as a force of repulsion is set up between primary and
secondary. To counterbalance this repulsion and regu-
late the movements df the secondaries, a counterweight is
attached to the lever system. This has a tendency to
bring the primary and the secondary coils together and is
set to counterbalance the repulsion for a given current.
As in the ease of the two-coil transformer, the counter-
weight is supported on an adjustable arc to compensate
for the difference in field strength in the various parts
(if the magnetic circuit.
Installation and Connections
Constant-current transformers are made in both the
air-cooled and the oil-cooled types. When of the former
pattern, all the parts except the counterweight are in-
closed in a suitable sheet-iron case, as shown in Pig.
5, with liberal openings at the top to provide the neces-
sary ventilation. Large openings are also left in the
bedplate for the same purpose. In the oil-cooled type
all the interior parts are placed in a tank and covered
with oil, its external appearance being similar to that
of the ordinary oil-cooled static transformer.
A diagram of connections commonly followed in the
use of the constant-current transformer on three-phase
systems is shown in Fig. 6. In the ease shown the trans-
formers are of the larger type containing two primaries
and two secondaries, and the windings are connected
for full load. However, it is sometimes desired to operate
on partial loads, under which conditions, owing to the
inductance of the primary coils, the power factor would
!»' considerably reduced were the full winding used. To
obviate this difficulty and thus maintain the efficiency
of the system, taps are provided on the primary whereby
part of the winding may he cut out, thus reducing the in-
ductance and raising the power factor. Taps are also
g( nerally provided in the secondary coils lor the same rea-
son.
Arc temps
Fig. (i.
Typical Diagram of Connections for Con-
stant-Current Transformers
transformer through a short-circuit, a ground, n light-
ning discharge or other disturbance. This tripping of
the switch is accomplished by a relay which receives its
1 56
P 0 W E R
Vol. 11, No. 5
excitation from a current transformer in one of the pri-
mary leads.
Cable transfer plugs are provided in the secondary
lines for the purpose of transferring the load on any line
to another circuit. This provides a convenient flexibility
in the system in case of repairs and other contingencies.
The open-circuiting plugs are for the purpose of discon-
necting the various circuits from their respective trans-
formers. The short-circuiting plugs enable one of the
two circuits of each transformer to be disconnected from
the system without affecting the operation of the other.
An ammeter is provided on the arc panel to give
current readings on the various circuits. To enable
the customary low-voltage switchboard ammeter to be
used, a current transformer is placed between the
ammeter and the line, thereby preventing the high
voltages of the line from coming in direct contact
with the ammeter. The transfer of the instrument from
line to line is accomplished by means of a plug attached
to a flexible cord. The plug is inserted into a jack or
receptacle attached to one leg of the respective circuits.
As an additional means for providing current indications,
a pilot lamp is connected in series with each circuit. This
furnishes an approximate indication when the ammeter
is disconnected.
Choke coils are placed in the various lines for the pur-
pose of forcing lightning discharges to jump to ground
through the lightning arresters, thus protecting the sta-
tion apparatus.
It will be observed that larger wire is used on the pri-
ma rv side of the transformer than on the secondary. This
is because on the heavier loads the primary, owing to its
constant voltage, may be taking a heavier current than
the secondary whose current never varies and is usually
about ten amperes.
The efficiency of the constant-current transformer,
when operating under full load, ranges from HI per cent.
in the smaller sizes to 96 per cent, in those of larger ca-
pacity.
In connection with the selection and appointment of
the members of the Steam Engineers' and Boiler Oper-
ators' Licensing Bureau .ocently authorized by the State
of Mew Jersey, the impression has been created that the
questions asked by the Civil Service Commission of candi-
dates to membership on the Board of Examiners were
abstruse and technical to such a degree that no practical
engineer could be expected to answer them. We have ob-
tained from the Board the list of questions used at the
examination which has been most discussed. Here they
are. Is there a question in the list which one who aspires
to be a slate examiner of engineers should not be able to
answer?
GENERAL QUESTIONS
A. State your experience, giving a complete record of where
you have been working the last ten years; stating the
size and make of each engine and boiler that you had
under your jurisdiction, also giving name of the man,
with his title, to whom you reported.
I',. "Write out five questions which you would suggest as
desirable to use in examining a candidate for a first-
class engineer's license.
('. Describe fully what you believe would be a correct
method to use in forming different grades for engineers'
and firemen's licenses.
Note: Candidates may ask examiner for explanation of
any question that is not understood.
WRITTEN TECHNICAL QUESTIONS
1. Show by a sketch how a (one) steam main should be
arranged in a boiler room in which there are two 200-
hp., 160-lb. pressure boilers and two 100-hp. 100-lb.
pressure boilers, so that at times all boilers might be
put in service at 90-lb. pressure, or, each may be used
at its respective pressure. Indicate all valves, reliefs,
safetys, etc.
2. Calculate the horsepower of a boiler plant that burns
35 lb. of coal per square foot of grate per hour under
boilers containing 10,000 sq.ft. of heating surface. Ratio
of heating surface to grate surface = 50:1. Heat units
in coal = 15,000 B.t.u. per pound. Efficiency of burning
coal in boiler = 60 per cent.
3. Show by a sketch a triple-riveted butt-strap joint, and
explain why longitudinal seams are butt-jointed and
girth seams are lap-jointed.
4. A flat plate, 16x12 in. is held against a tank by four
1-in. bolts; what is the safe pressure to use in the tank,
assuming factor of safety 5, tensile strength 50,000 and
diameter root of thread = 94 in.?
5. Show the arrangement of tubes, doors, etc., indicating
the location of grate, smoke flue and baffles, for
(a) Babcock & Wilcox cross-drum boiler
i b i Stirling boiler
<c> Heine boiler
(d) Horizontal return-tubular bo'lei
6. (.a) How many square feet of grate should there be for
a 500-hp. boiler burning soft coal?
(b) How large a piston should thero be in an engine to
develop ram lip., if the mean effective pressure is 100
lb. and the piston speed is 250 ft. per min. ?
7. If the eccentric of an engine is set so that it has an
angle of advance of 2S deg., and if it is desirable to
change the direction of rotation of engine, exactly how
many degrees would you move the eccentric and in
which direction, so that the angle of advance would still
be 2S deg.?
S. How could you increase the operating speed of a fly-
ball governing Corliss engine and yet have the "cutoff
the same?
9 If a cross-compound engine was out of adjustment how
would you proceed to correct the steam distribution, so
that equal work would be done on both cylinders?
10. Explain in detail how you would proceed to erect a
girder-frame engine so that it would be level, true and
aligned up to connect to a flange on a shaft already in-
stalled.
11. (a) What is meant by "clearance" of an engine?
(b) How could you determine the location of the piston
in respect to the ends of the cylinder, without removing
the heads?
(c) At which end of the stroke should the greater dis-
tance to the cylinder head be allowed? Why?
12. Show by a sketch how the exhaust-steam piping should
be arranged for an engine operating with a surface con-
denser, indicating all valves, reliefs, etc.
Note: An examiner was present during the examination
to explain any question that was not understood
by candidates.
ORAL QUESTIONS
The candidate upon finishing the above set of questions
will be examined orally on practical questions submitted to
him in the engine and boiler room.
The candidate may answer the questions orally, or by
demonstration.
Note: The general questions asked the last candidates
were in connection with the following:
Cross-Compound Corliss Engine with Plyball (;overnor
1 Trace path of steam through the engine.
2. Explain the use of pipe pointed out (atmospheric relief
pipe for high-pressure cylinder).
3. Examine, and explain completely the action of the en-
gine governor.
4. Explain why the engine would not speed up if the gov-
ernor belt broke.
5. Explain the use and principle of operation of the dash-
pot.
Hift-li-Siieed Vertical Compound Engine. Double Vcting
6. Examine, and state type of engine.
Single-Cylinder Horizontal Engine, with Inertia Governor
7. Explain operation of the governor on the engine shown.
Vacuum Pumn
8. Examine, and state what the piece of apparatus pointed
out is used for.
February 2. 19]
I'd W EE
157
AA'orthinK-ton Surface Condenser
9. Examine, and st:i tf what the piece of apparatus pointed
out is used for.
Open-Type Feed-Water Heater
10. Examine, and state what the piece of apparatus pointed
out is used for.
11. Is the heater shown an open or closed type?
Forced-Draft Apparatus (Engine and Centrifugal Fan)
12. Explain the ust- of the apparatus pointed out.
18. Does the engine have a lighter load with the forced-
draft slides entirely closed, or with them entirely ..pen?
P2*es@uas;>a©l&dl Wattes3 GaM©
This water glass is
used to lock the r<
--5_^JI IT
-....
TgSJ*aj»
I 11
ii/n
j£
^m.
, . "
Fig. I. Details of Pressui
lokd Water Gage
j designed that the boiler pressure
istgring glass, which prevents the
glass from flying
should it break, and
also prevents the es-
cape of hot water
and steam. A sec-
tional view is shown
in Fig. 1.
The oufit consists
of a metal- ga ge
frame in which the
registering glass . I .
Pig. ".'. is held in
place by a metal-
sealed joint C to tlie
scat II, by a back
piece N and a hold-
ing spring /. The in-
terior parts are held
in place by a set-
screw L \\ hich, when
screwed down to its
copper sealing wash-
er, puts the proper
tensioi the spring.
This tension, supple-
mented by the steam
treasure at the points I), holds the backing piece and met-
d-incased glass to its seal on the inside of the frame, thus
iressure-packing the metal-sealed joint. The steam pres-
Fig. 2. Cross-Section of ttik Gage
sure around the sides EKK and on the ends of the metal-
incased glass locks the glass. Should the glass crack, the
externa] pressure on the side ami ends presses the shat-
tered pieces closer together, which prevents leakage and
the flying of glass.
The registering glass is incised with a sealing metal B,
with the exception of
the sigh! opening in
front and the reflex
part at the back. The
metal frame seats Oil
the serrated front C
of the metal casing
a r o u ii d the sight
opening G inside of
the Ira me. The
spring which holds
the glass to its seat
permits it to expand
and contract on its
seat, thus relieving it
of strains.
The space K back
of the glass commun-
icates with the water
space •/. and to the
boiler through water
and steam passage-
ways. The steam and
water connections to
i ]t f boiler a r e
straightway and, as
iki separate water col-
umn is used with the
g lass, straightway
valves are used in the
connections. K a c h
valve is fitted with e
semaphore h and] e.
which shows whetliei
the valve is open or
closed. M is a clean-
ing plug.
The universal type
of water glass, de-
signed for any type
of stationary boiler, is shown in Fig. 3. It contains the
features of the locomotive type (Fig. 1 ) and is provided
with a separate steam passageway, no water-column reser-
voir being used.
In case the glass breaks, the closures at the top and
bottom of the frame are unscrewed, the setscrew is
released and the old glass removed. When the new
glass is inserted the setscrew is turned to its seat, cop-
per gaskets inserted and the closures replaced.
These water gages are manufactured by the Prince-
Groff Co., 50 Church St., New York City.
:*:
In "The Year's Review," published in our issue of Jan. 5,
we tailed to mention that the first unaflow engine built in
this country under Professor Stumpfs patents and under the
supervision of his American representatives, was erected at
Auburn, N. V . by the Ames Iron Works. We are glad to
learn that the success of this first engine has led to numerous
orders, and hope soon to be aide to describe a considerable
installation.
FlG. 3.
Universal <i ige for
Any Boiler
P 0 W E R
Vol. 41, No.
By W. X. McKee
SYNOPSIS An explanation of the use of charts
for determining the power requirements of am-
monia compressors for different suction and dis-
charge pressures.
The power required to drive ammonia compressors is
a constantly varying quantity due to the many operating
conditions possible with such machines. Likewise, the
amount of ammonia gas which it is necessary to circu-
mimliei- of plants in various parts of the country. These
plants mnsi necessarily be operating under widely vary-
ing condition.- which different climatic conditions make
inevitable. To meet these conditions and include the
greater number of variables, Charts I and 11 have been
prepared and used by the writer in records covering the
operation of a number of refrigerating plants.
Chart 1 is based on a table in a paper read by Thomas
Shipley before the 190(5 meeting of the American So-
ciety of Refrigerating Engineers. It shows "the mini-
/
}r
30
y.
'
.-•'
X-
Ay
A~
/\ /
aXx.
AX
28
' y
/ X / 'a
s//\
Xx X
/i Ay
'XXX
XXXj,
'XXX
X / /
X a
y / ' y
XX?Z>
?4
XX' \/
/ Xvft
A
1/
X Xy
/yV//
4P\/
/yyy
22
~&\7~'
/%v/
//
(XXXXy
S X*X\X\
V
Y x^^Xa
^xXXy
as \x\ y
t
a& 'Kly
/
/)r\//'
4
&/
7//
/ X 'a \ /
20
r
yl** /
a"l£7
jr / YY^\/\/ y
Y*
xx/xxxx
-fcV A
/*//4k>v7
18
m Y
X^syyA-toW
XXX'
XXXXX<X^X<t
XXAXy
V
\\A
X X X^
'X\XX/
A^AAAA^
XX X XXXXX*
/\ / / /
CWX-
XXXX
■\
Xxxxl,
/ /
yyxx&
A 1 '/I
X\ X
XXXXXL
XXxX
___
} /
X^XXs
XXXAXf&A s
]a
/
/ /
XXXXX
X/XX
' l
x/Vy
Y//XX/
'axxx
/ \<A A//
XX
<XaXy,
XXXyv
WYy
XXXXy
10
<XXXX
'/,
V7//
<a
/
/
f
s&XX s
s
A
^XY\ '[
L>
120 WC 160 160 200
Condenser Pressures, Pounds Gage
Chart I. Power Required pee Ton Refrigeration foe Various Sui tiom ami Condenseb Pressures
late to produce certain amounts of refrigeration may
vary in equally wide ranges.
The engineer who keeps records of costs in the opera-
tion of the plant has been compelled to go through a
tedious routine of figures to maintain his daily records.
This process becomes a burden when the engineer has a
mum theoretical power utilized in a compressor to com-
press sufficient ammonia gas which, when liquefied at the
pressure stated, will, upon being evaporated from the
temperature corresponding to the given pressure to the
temperature corresponding to the pressure in the evap-
orating system, do the same amount of work (have the
February ?. 1915
P O W B R
159
game ling effect i as is done in the melting of one ton
o ice." The kilowatt-hours, if the compressor is motor
driven, to fulfill above conditions in a twenty-four hour
period, is shown on the right, and the horsepower required
is given on the left-hand margin. In each case the volu-
metric efficiency of the compressor and the efficiency of
the motor are assumed as 100 per rent.
('hart II is tn be used for closely estimating the work
of the compressor or the amount of refrigeration pro-
duced over any period when the capacity and volumetric
effii ii nc) "I the compressor are known.
pressor efficiency it will require 1.11 hp. per ton of re-
frigeration. Assuming 80 per cent, volumetric effii i
then 1. 11 divided by 0.80 and 1"> per cent, added for
friction load, ^i\ l'> nearly 1.6 hp. per ton refrigeration.
To the left it will be found that it requires 20 kw.-hr.
per ton refrigeration in twenty-four hours at 100 per
cent volumetric efficiency of the compressor. Then 20
divided by 0.80 volumetric efficiency and 1"> per cent,
added for friction, dividing this figure by 0.90 (approxi-
mate motor efficiency) gives 31.94 kw. per ton of refrig-
eration iii twenty-four hours. The total current consumed,
■i
:
R
<i
„. PR
s
I L
nirTI
V
"i
u
■
[^
■^
„
.^
,-- —
±-
J
-r
^^
j—~^
i
1
^^- — -~"
^^_^,
_^--
LL
\ i
-*p
. -
8
"li
^j
—
^
_
■ — r
.Li—
II
J — — 1
I LL
— — ; —
X-
"" M .
■ n
1
__U^— 4
^___
— rr |
LUr
i ML
J-H —
ll'.'J — r- ^
—
^_— -
^^
-~~~"^
;2 :Jj-
""H
__
*1— — — -
' — r~"Ti
-~~ '
i ■
■ n la l
— ■
__^ — - — "*
*
J 1 —
_i__
i ! L
.
\. — — *
1
, — ■ —
_^_— --
;
^
-f-
____. —
*" .
-
b
___ — ■
1
__^ — - — i —
._
— f
1
M-
____
— "
_.- -
- — J *"
^_^ — — -—
'
I L
17
4=-
- — =j
LL
- — ~~~_J$— '■— — '
. —
F :_
_^— ~ -1
^____j--
-f=r
= — r~"
— H — f
u
i — ~~~~\
-=—
L-
__]___—
^__^—-
~"~~"H
-LI"5** 1
- —
:-=— -
— *" — J_22_ —
SH^-
_^=—
4fB —
^24-
5
6
-f-+-f^
-^^Z-
~- -"j"]""1
1 - —
-JJTX-
-~n^^
-^r~£
tdX
i ■ ■ i
j m.
, — =*=
^^^
~^~^~5-
=
:
J-j-j-j-
ZX^Zi
T
1
'
-
—
!
__i°
-fT
1 1 1
40 60 60 IOO 120 140 160 180 200 220 240 260 280
Condenser Pressures.Pounds Gage
Chart 11. Volumes of Gas peb Toy Refrigeration fob Various Suction and Condenser Pressures
This refrigeration as given is expressed in tons per
twenty four hours. In the use of Chart I, take as an
example an average condenser pressure of 180 lb. gage,
average suction pressure, 16 lb. gage, to find thie horse-
power of the motor or engine required to drive a 100-ton
compressor, also the current consumption on a twenty-
four-hour load at the given suction and condenser pres-
sures, follow the line for 180 lb. condenser pressure
up, until it meets the 16-lb. suction-pressure line, and
then along on the horizontal line to the right for the
horsepower to drive and to the left for kilowatt-hours
per ton for twenty-four hours. At 100 per cent, com-
31.94 times 100 (rating of the compressor) gives 3191
kw.-hr.
In the use of Chart II. it is necessary to know the ca-
pacity of the compressor over some definite period. II
the machine starts and stops frequently or is of the auto
matic type without attendance, a revolution counter
should be attached by which the capacity will be known
over any period regardless of frequent stops.
As Chart II gives the number of culm- feel of gas i
quired at 100 per cent, efficiency, it will be necessary to
find the actual displacement of the compressor at the op-
erating pressures for the proper period of time or mini-
1G0
P 0 W E Tt
V..1. 11. No.
ber of revolutions. It is advisable to bring the displace-
ment of the compressors to the same condition as stated
in the chart, or 100 per cent, for a definite time, and thus
obtain results by one division or multiplication.
The power required to drive small ammonia compres-
sors of the single-acting type where the condenser pres-
sures are nut known hut are for average refrigeration will
be approximately as follows:
Capacity
Tons
I [orsepower
-■'.•■quired
Capacity
Tons
Horse powe
Required
1
2
3
2
3%
5
S
9
10
14
15
IT
Iii the table a friction load of 15 per cent, has been
assumed. This would be the average for medium to large
engine-driven units. Fur smaller units ami belt drive the
friction load may run greater, although the worst condi-
tion is seldom over "^O per cent.
If the ammonia liquid is cooled below the temperature
corresponding to the condenser pressure, the tonnage
will he increased thereby, hut as this is not a usual oper-
ating condition it has not been included in the charts.
The standard conditions have been assumed in which a
ton of refrigeration is equivalent to tin' circulation of
Z6A Hi. of anhydrous ammonia per hour at 15.6'! lb.
above the atmosphere, condensing pressure taken at is.",
lb. gage pressure.
!\uiini{t<
>ttnm\g
,im^iini<
By W \i;i;k\ ( ). Rogers
SYNOPSIS — We visit an uptodate power plant
and Hunter discusses high- and low-priced ma-
chinery; he points out that cheap units are un-
economical in operation. Some examples of waste-
ful pumps and fan engines are given as well as
the reason for their condition.
The next morning after our visit to Scalp Level I was
up and ready for another tramp before Hunter put in
an appearance. When we started out For the day. we
headed for No. 35 colliery of the Berwind-White Coal
Mining Co., at Windber, Penn. Here we found two 100-
station did not cut much ice with these operators; that
they found it economical to generate their energy on the
ground where it was to be used.
'"How is it that tin- company has built such substan-
tial power plants while others appear to have been built
apparently for short occupancy?" I asked, at the same
time yanking Hunter out of the way of an electric loco-
motive drawing a train of empty coal cars into the mine
Hinder calmly proceeded to count the cars as they
rumbled past — an even hundred. I believe — before he
turned to answer my question.
"That is business," said he. ••These mines are a long
way from a central station in the first place; in the see-
Fig. 1. Power Plant from Wiik ii X<
Collier's T- Opeb i rao
kw., three-phase. 25-cycle, 6600-volt turbo-generators
running at 1500 r.p.m. There was also a cross-compound
engine-driven unit, the generator having the same phase,
cycles and voltage as the turbine generators. Beside this
equipment and the motor- and engine-driven exciter
units, there were two 225-hp. motor-generator sets deliv-
ering alternating current. Fig. 1. M. J. (iross. the en-
gineer of tin' plant, told us that the electrical energy
was transmitted to eight substations ami then trans-
formed to 550 volts direct current for use in the mines.
Steam for the plant was generated by twelve 250-hp.
water-tube boilers equipped with mechanical stokers.
Here was a plant as uptodate as the one we had visited
the day before. That both were owned by the one com-
pany was a striking indication to me that the central
ond. it will be a good many years before the mines will
be worked out. For these reasons n is advisable to put up
.■' substantia] building to house the generating units. If
the mines were to give out within the next few years,
inexpensive buildings would have been the proper struc-
tures to have put up. The machinery, however, should
he of the best, for when the present mine workings are
abandoned, the machinery can he moved to a new site
for further use."
"Well, that's clear enough, hut with high-priced ma-
chinery the lived charges will be high, while if the ma-
chinery is low in cost they will be correspondingly low."
"Right yon are, but don'1 forge! that low-priced ma-
chinery makes high operating costs. A (heap engine
will generally consume an excessive amount of steam.
February 2, 1915
POW E B
161
which means that nn increased boiler capacity must be
had over what would be required with an economical en-
gine plant; this, of course, would lower the saving made
on the price of the engine.
"My contention is that cheap machinery means high
maintenance costs, let alone the losses occasioned by fre-
quent shut-downs.
"When these units were put in," and Hunter motioned
toward the power plant, "they were selected, no doubt,
after the question of first cost and operating costs had
been considered in conjunction with the load that could
be expected during the year. The result was a plant
containing expensive machinery and reduced fixed
charges, low steam consumption, small repair bills and
satisfactory operation. The opposite could be expected
with low-grade apparatus."
Fig. 2. The AVaste of Steam ix the Average Mine
Plant Is Due Largely to Bake Pipes, Leaking
Joints and Wokx Engine Valves and
Cylinders
"You would recommend direct-connected units in pref-
erence to belted generators, I suppose?"
"I certainly would, because with direct-connected units
all troubles from belts slipping, belt repair, etc., are out
of the way, less floor area is required, and a smaller build-
ing can be used, which means a lower first cost."
"The fact that the general arrangement of the plant is
simple, without any attempt at frills, should help with
the first cost and with that of maintenance."
"Now you're talking ! While simplicity does not mean
(ulting out necessary apparatus, there is no sense in put-
ting in lines of piping to provide for a breakdown that
in practice seldom comes. A steam plant should be de-
signed to avoid as much as possible all chances of break-
downs, and, therefore, the best of material should be used
at all points, for one breakdown caused by faulty ma-
terial will offset flu' cost of the best many times over.
Did you notice how the coal is delivered to the boilers?"
I confessed I had not.
"I'm surprised, because the delivery of coal to a boiler
plant is of importance. This arrangement here is about
as simple as it can be. Coal fresh from the mine is taken
to the boiler house in the mine cars and, after passing-
through a coal crusher, is delivered to the coal bin above
the stoking aisle in the boiler house. Of course, this is
an exception, because but few steam plants are situated
to take advantage of a drift or a slope level with the
boiler-house coal bunkers."
"When you speak of simplicity of design don't you
favor cross-connections, so that where several engines have
their batteries of boilers they can be arranged to operate
with another battery?"
"Now, don't make a mistake; I haven't said any such
thing. In fait, interconnections between boilers and en-
gines should lie so arranged that any boiler or set of boil-
ers can be used with any engine. The idea is that this
arrangement gives the engineer an opportunity to make
repairs to any set of engines or boilers without interfering
with those in operation.
"\\ ith some arrangements of pipe lines there is no cer-
tainty that a supply of steam will lie had for the fan
engines, pumps and hoi-ting engines in case a boiler
tube should burst. One safeguard against the stoppage of
the steam supply is to equip each boiler with a nonreturn
valve. Then if a tube does fail, putting one boiler out of
service, the others will supply enough steam to operate
the mine. If an accident serious enough to wreck the
boiler plant occurs, then the best protected piping would
be of no avail."
"I'll tell you, Hunter, I think the piping between the
boilers and engines should be short, and provision made
to take care of expansion in all high-pressure steam lines.
For the life of me, I can't see how many steam lines could
be any shorter than they arc, although they may be sev-
eral hundreds of feet long."
"Unless the mine is equipped with electric drive there
is no way to get rid of long pipe lines, and unless prop-
erly drained there will be trouble when the water reaches
the engines in large quantities, as there is danger of its
doing, and wrecking the engine. On the other hand,
if the water of condensation gets back into the main line
there is danger of bursting the fittings by water-ham-
mer. Not only should the pipe lines be drained, but the
valves should be placed so that there will be no pockets
of water when the valve is closed."
"The idea is that the pocket of water would go to the
engine in a slug when the valve was opened?"
"You've hit it exactly ! It is easy to collect such water
in traps and return it to the boilers."
During the conversation we had made our way toward
a fan house in which was a motor-driven fan. The ab-
sence of leaky pipe joints, piston packing and pounding
engine was noticeable. Furthermore, the room was clean
and free from the mass of grease and general filth so
often found.
"This is a good object lesson in favor of electric drive,"
observed Hunter; "everything neat and clean, no vibrat-
ing steam pipes and other annoyances."
"Some steam lines do vibrate; how would you pre-
vent it?"
"Putting in a receiver near the fan engine will fre-
quently stop vibration if the receiver is of sufficient size
to supply the engine with steam without materially lower-
ing the pressure in the receiver. This would allow of a
practically continuous flow of steam to the engine from
the boiler and relieve the pipe of pulsation.
"The waste of steam about the average mine power
plant is frightful, due to bare pipes (Fig. 2), leaking
valves and worn cylinders. When there are apparently
not enough boilers, more are put in; this is generally
a waste of time and money. It would be more to the
162
p o w E i;
Vol. 41, No. 5
point to put all the engines and pumps in first-class con-
dition, thus consuming a minimum of steam. Then the
existing boiler plant would be sufficient for, if not in ex-
cess of, the steaming capacity required."
"You don't seem to have a high opinion of the steam
equipment of some mines," I remarked as we left the fan
house and started toward the street-car tracks in the
town.
"Do you know thai there are pumps operating in mines
mi a 2-1-hr. run which have been in use thirty or forty
years and consuming — well, 1 wouldn't want to say right
out, but 160 Hi. of steam per water-horsepower would
not be too high a figure.
"What can be expected when a pump is operated for
long periods and not shut down until something hap-
pens? When repairs are being made, nobody thinks of
making the pump run more economically: the one idea
is to get it hack in service as soon as possible, and but
little attention is given to the condition of the cylinders,
pistons, valves, etc. It's no wonder that steam is
wasted.
"The same neglect is found with fan engines. They
run day and night, seven days a week, and there is but
little opportunity to overhaul them. I have known ol
fan engines that used about SO lb. of steam per indicated
horsepower-hour when half of that amount would have
been excessive.
"The great trouble is that many mine operators con-
duct their business with the idea of getting a maximum
coal out put and pay little, if any, attention to the ma-
chinery that makes this output possible."
That afternoon we packed our grips and made for
Pottstown, where, we were informed, there were several
interesting collieries. •
i Primople Applied! to
)nmalll Einielinies
SYNOPSIS— This engine, of German design, is
of Ihc high-compression, double-piston type and
embodies simplicity as well as compactness. With
a direct-connected generator it is made in sizes of
10 to W Jew.
A successful attempt to adapt the Diesel principle to
the small oil engine has been made by the Allgemeine
Elektricitats Gesellschaft, of Berlin, which is now put-
ting out direct-connected generating sets, in the two-cyl-
inder model, with capacities of 10 to -10 kw. The engine
is of the double-piston, two-cycle type, employing 420- to
."iiO-lb. compression and a fuel-injection pressure of ap-
proximately S-iO lb. In order to insure reliability in
the hands of unskilled attendants, simplicity, accessi-
bility and interchangeability of parts have been made an
important feature in the design, and compactness is fur-
ther increased by having the end of the crank case ter-
minate in a flange to which is connected the stator of
the generator.
Referring to Pig. 'i, the compressor is seen to be
mounted in line with the working cylinders and is driven
from the main crankshaft. It comprises a two-stage in-
jection pump E ami a scavenging pump /'. The latter is
double-acting and is regulated by a rotary slide valve
mounted on the vertical intermediate shaft. The upper
part of the crank case forms a scavenging air reservoir /,.
into which project the lower ends of the cylinders. These
are provided with scavenging port-, so thai the air follows
the most direct path. The relative locations of the pump
/' and the reservoir /, do away with the necessity for
intermediate piping. The injection pump is fitted with
ring plate valves.
The air for starting and for fuel injection is stored
in the cylinder F, located with the lubricating receptacles
S in the under-frame id' the engine. This not only pro-
vides a more coincident arrangement, but also allows the
numerous valves for starting and fuel injection to be
replaced by a common distributor, which carries a man-
ometer (see Fig. •">) and a safety valve.
Amply dimensioned hand openings are provided, per-
mitting convenient inspection and removal of parts. The
driving gear is provided with forced lubrication, the oil
being led to the bearings through passages in the casting
and then distributed through recesses in the crankshaft to
the pivots of the connecting-rods and the suspension rods,
finally rising further through pipes to the piston pins.
Nonreturn valves prevent the oil from running into the
pipes when the engine is at rest, and a hand pump per-
mits the pipes to be filled or washed out while the engine
is idle. In the larger sizes the pistons are oil cooled.
In this case the oil, which is supplied by a gear pump,
flows to the lower pistons through jointed pipes and to
the upper pistons through conical pipes, finally discharg-
ing through funnels.
A special point has been made of rendering the piston
easily demountable. In about 10 minutes after stop-
ping, the upper piston can be removed, and in another
10 minutes the lower piston can be taken out. These
operations arc shown in Figs. 2 ami 1. There are no
pipes to be disconnected, no valves to be removed, and
no covers, tightened by packing, to he unbolted.
The crankshaft is driven by worm gearing through a
vertical intermediate shaft, which can be removed bodily
with the bearings and wheels after loosening a few bolts.
The governor, mounted at the front end of the cam-
shaft, works directly onto the fuel pump by means of
an adjusting rod sliding in a slot on the camshaft. This
does away with any external lexer transmission. The
handwheel shown is for adjusting the speed, which can
be read from a tachometer placed above it.
Some difficulty was experienced in designing the fuel
pump for the small engine, especially in connection with
the regulation of the quantity of fuel, which in many
cases amounts to only a few drops. As the same amount
of work is done in one cylinder of the new engine as in
two cylinders of the single-piston type, however, the
quantity of fuel per cylinder is doubled, and its regula-
tion is thus simplified. Tt is effected by the movement
of a cam acting on the suction valve. The starting valves
arc controlled mechanically by means of cams from the
February .. 1915
I'M WEE
163
Figs. 1 to 6. Showing Engine and Generator Complete and the Ease with Which Parts Mat
Be Removed
1' OWE li
Vol. 41, No. 5
camshaft. The driving lever A (Fig. I) for the start-
ing valves and the lever for the injection valve are ar-
ranged eccentrically, so as to bring them into operation
alternately by switching over a lexer. For starting, thi re-
fore, it suffices to open the air admission l>\ mean- of
the handwheel B, and to throw over the hand lexer. These
starting valves are accessible and can be exchanged in a
lew minutes. The injection valves for admitting the fuel
into the working cylinder are placed opposite the start-
ing valves, and the needle is likewise moved by means
of a disk from the same camshaft. If it should prove
necessary to repack an injection-valve needle, the entire
Fig. 7. Longitudinal and End Sections through Engine
Fig. 8. Engines Set Up foe Testing at A. E. G. Wobks
February %, 1915
r 0 W E K
105
valve can be taken out after the engine bus been shut
down, and a spare one put. in its place; this takes about
15 niiii. The adjustment of the play between the cams
and camshaft and the roller of the driving lever, and
therefore the exact timing for (he opening of (be needle,
is carried out by means of calibrated disks placed be-
neath the needle.
These engines are built lor a speed of 500 r.p.m., al
which they develop their normal output.
ductive of the besi results. If (be firemen are able to
save the plaid money by their efforts, they should logi-
cally be entitled to a part of it.
The largest single item in the operating costs of any
steam power plant is coal. In most plants the purchase
of coal is a matter of careful consideration, and in the
larger ones it is usually bought under specifications.
Once the coal is in the bunkers, this careful considera-
tion slops and the actual burning id' the coal is very
rarely given more than a passing thought, as long as the
steam pressure is kept up. Of course, there are some
plaids where this does not. apply, but in the majority it
The men employed are paid the lowest possible living
Wage and are chosen more on the basis of the wages
they will work for than the results they are abb' to pro-
duce. The man who burns the coal can easily vary the
efficiency of the boiler by 10 to 15 per cent., or the heat
absorbed by 15 to 20 per cent., yet he is at the bottom of
(be payroll.
Xo revolutionary advancement has been made in power
plant- recently, and the increased efficiency is accom-
plished only by taking each process separately and bring-
ing it up to the highest standard. It would therefore
seem wise, in attempting to increase the overall efficiency
of a plant, to start with the item that represents the
largest expenditure and work down the list.
In office-building plants the cost of coal represents
.Mime 35 to -10 per cent, of the total expenses and boiler-
room labor 12 to 15 per cent. In big plants (be cost of
coal is 50 to 55 per cent, and the boiler-room labor 7 to
8 per cent. Take a concrete case of a certain office build-
ing in New York Gity (bat employs two firemen at. $000 a
year each. Their coal costs approximately $10,000 a year.
If we assume that the boiler efficiency is 60 per cent.,
and that by paying $1100 a year men could be obtained
who would operate the boilers al an efficiericy of 70 per
cent., it would be a paying investment. The increase in
wages is $ii00 a year. The increase in boiler efficiency
amounts to a reduction in coal burned of 14.3 per cent., or
$1 130. The net result is $830 to the good by the change-
not a matter of philanthropy.
Any plant owner can figure out for himself what a
small increase in the boiler efficiency will amount to in
dollars and cents, ami may find it profitable. The effi-
ciency of the boilers may be increased in several Ways,
but first, proper equipment must be furnished. Every
boiler plant should be equipped with a draft ga<;e, stack
thermometer and means for determining the CO.. The
cost of this whole equipment need not exceed $100, which
would be repaid in a very short time.
Then the firemen should be taught the use of this ap-
paratus to determine the proper method of handling the
fires to secure the highest efficiency. A bonus system
for savings over a certain amount would probably be pro-
Tbe Dayton Pump & Manufacturing Co., of Day
ton, Ohio, is placing on the market a new power-driven
Fig. 1. Motoi;-Driven Duplex Double- Acting Pump
pump, Fig. 1, of the duplex double-acting type. Being
double acting on both sides, four impulses are imparted
for e\ei\ revolution of the cranks, and a steady stream
Fio. 2. Vikw Exposing Valve and
Pulsation Chambers
160
1' 0 W E B
Vol. 41, No. o
is discharged. The cranks are set at 90 deg., so that
when one piston is moving at its highest speed and de-
livering its greatest amount of water, the other piston is
moving at its lowest speed and delivering a proportion-
ately smaller amount of water. In this way the flow and
torque are equalized, so that a minimum expenditure of
power per cubic foot of displacement results.
An unusual feature is an air chamber over each valve
chamber, and in addition, a large air chamber forms part
of the body of the pump immediately under the gears.
As a result of these five chambers there is no perceptible
wave line to the discharge, which is practically as steady
as the outflow from a centrifugal pump. The arrange-
ment of plunger and valves is shown in Fig. 2, a sec-
tional view of the pulley-driven pump. The new motor-
driven pump is made for pressures up to 100 lb. and is
designed primarily for house service.
unairaeg^s
^tmlbsvo
The accompanying illustration shows the five chim-
neys constructed by the Weber Chimney Co. for the
Havana Railway, Light & Power Co.. Havana, Cuba.
In 1910 the company built a cylindrical chimney
200 ft. high by 10 ft. diameter, of reinforced concrete.
After it had been in use approximately three years, a
consolidation of the Havana Railway. Light & Power Co.
and the Havana Gas Co. necessitated the construction of
a large central station, which was started early in 1913.
An order was placed for four coniform reinforced-concrete
chimneys, each 275 ft. high and 1-1 ft. inside diameter
at the top. Six months from the date of starting work
these were completed.
The chimneys rest on individual foundations 32 It.
qttare and 6 ft. 6 in. thick, supported by piles. In the
lower part of the foundation are four layers of steel. The
bottom layers run diagonally to the sides and consist
of %-in. round bars at 8-in. centers: the two upper
layers are placed from 4 to 6 in. above the diagonal tie!
and about 8 in. from the bottom of the foundation, and
run parallel to the sides. The vertical liars in the shaft run
into, and anchor beneath, the horizontal steel reinforce-
ment in the foundation, providing anchorage for the
chimney shaft.
The outside diameter at the base of the shaft of each
chimney is 20 ft. 6% in., tapering to an outside diameter
of 15 ft. at the top. The wall thickness of the shaft at
the foundation is 19 in., tapering to 6 in. at the top.
There are two hundred %-in. round vertical bars in the
shaft, extending to a heiglrl of 22 ft. above the top of tin
foundation, where tin' number is reduced to 132 for the
next 20-ft. section, decreasing uniformly to the top. where
there are sixteen %-in. round vertical bars in the upper
30 ft. of the chimneys. The smoke openings (7 ft. 2 in.
wide by 1 I ft. 2 in. high) which received the breeching
from the boilers are 56 ft. above the foundation and are
20 per cent, larger than the area of the chimney at the
top. There are two opposite openings in each chimney,
and a baffle wall is built in the center of the chimney,
starting 2 ft. below the bottom of the openings and ex-
tending to a point 3 ft. above the top.
There is a reinforced-concrete lining 58 ft. 6 in. high,
starting at a point I ft. below the opening. The lining
is reinforced vertically and horizontally by sixteen V^-in.
round vertical bars, evenly spaced, and by horizontal rings
at 14-in. centers encircling the vertical members: thes<
take up the shearing stresses caused by the wind and tem-
perature. The lining is carried on a corbel supported by
the outer wall of the chimney. All vertical steel in the
shaft is calculated to take up stresses produced by a wind
velocity of 100 miles per hour.
The chimneys are inside of the power house, and in
order to utilize the space two storage rooms were provided
in each. A floor was placed at an elevation of 18 ft. above
the foundation, and an opening provided so that this
part of the chimney is accessible. At 36 ft. above the
Keineokced-Coxckete Chimneys for the Havana
Powbb Plant
foundation is another floor and storage room. A ladder
is provided on each chimney, running from the lop of the
chimney to the roof of the building.
The present boiler installation consists of 2 1 water-
tube boilers, rated at 650 hi>. each, a total of 15,600 hp. :
provision has been made for eight additional stoker-fired
boilers. Three turbine generators of 10.000 kw. are
operating at present, with provision for an additional
unit.
The Action <>f Ice ami Common Salt (sodium chloride) is
to lower the mixture temperature below 32 dec The de-
pression of temperature depends mainly on the proportion
of salt used, and partly on the rate at which heat is supplied
from the outside. The following table gives the approximate
temperatures resulting from the use of different proportions
of salt and ice:
Per Cent, of Salt in Mixture
Emu of Mixture. Deg. F.
26.6
10 i 9 9
1", 11. S
20 i E
The minimum temperature obtainable with ire and salt
is about — 7.5 .lei.'. P., this temperature being given by a 84
per cent, mixture.
February 2, 1915 P 0 W E R 167
i i milium i n «» mm iiniiiiiiiiiiiin i imiiiniiim mi i mining
Itoirii&Ils
paiiniiiiiinii i < '[nniiiiiimmiiiuimiiiiiinmiim!
The slogan, "Made in America," is aimed to incite
domestic industries and manufactures. As a result many
new factories will be built in the near future and probably
many old plants will be remodeled to meet increased de-
mands and manufacture new lines. All of these factories
will require power, which will benefit the central stations
and also be the occasion tor many new isolated plants —
some large and some small. To manufacture economical-
ly, cheap power will be required, will be absolutely neces-
sary, and though the "Made in America'' indorsement
may secure many sales at tins time, when serious foreign
competition is not felt, the time will come when only the
American producer who is manufacturing economically
and efficiently will be able to bold bis own.
Even in an efficiently operated plant, from twelve and
one-ball' to fifty per cent, of the cost of power is found
in the coal bill, the large power bouse operating on the
lower unit cost. Coal bills must then be kept down, and
to do this only the economical coal must be burned, the
coal that will evaporate the most water for a given out-
lay. This does not mean the best coal procurable nor yet
the cheapest; it means the most economical, for efficiency
in combustion is almost entirely a matter of correct grate
and combustion-chamber design and can; in firing, con-
ditions that may be relatively realized with the same re-
sults when using a low-grade coal as when using the more
easily consumed coals of High heating value.
The price of coal varies to a greal extent in different
localities, and coals vary among themselves in heating
value and in ash anil refuse contents. The beat units in
the coal increase its value but not proportionately, for the
ash and refuse contents not only add expense by entailing
definite outlays for their disposal, but also have the ten-
dency to reduce boiler efficiencies. Of two grades of coal
of equal heating value, the one with the lower proportion
of ash and refuse will develop the greater boiler effi-
ciency— grates and combustion chambers being equally
well proportioned for their respective grades of coal and
equally good attention paid to the firing of the boiler.
The detracting effect of increased ash and refuse contents
of a coal is not as great ordinarily as the beneficial effect
of an increase in heating value of the fuel, the diluents
forming but a comparatively small proportion of the coal,
unless it happens to be a very inferior grade. Heat units
per pound generally govern the price of the coal, but the
price in no way fixes its true economic value, for the in-
crease in cost of high-grade coals is much more rapid than
the increase in their heating value.
As a general rule, where coal is relatively cheap— near
the source of supply, for instance — more beat units are
purchased for the dollar when buying a low-grade coal.
Where coals are expensive, on the other band, the heat
units sold for a dollar are more nearly the same for coals
of various grades, as in such localities the coal has to
carry a burden of freight and delivery charges that are
not proportioned to its heating value but are unduly
severe on the poorer coals, notwithstanding that freight
rates are usually somewhat lower on poor fuels. Where
coals are cheap, the most economical grade to use is the
poorest grade that can be efficiently burned on properly
proportioned grates, etc.; while in sections of the country
where coals command high prices, better grades can be
economically used.
With the constantly increasing price of coals, one other
genera] rule tends toward economical choice of fuel for
an efficient power house, which is that in eases where two
grades of coal do not vary greatly in economic value —
fuel cost per boiler horsepower — it is usually advisable to
adopt the poorer grade r\r<[ when the net fuel cosi is
slightly greater than that of the higher-grade coal. The
fuel cost of the more economical and higher-grade coal in-
creases more rapidly for an increase in tonnage cost of
fuel than is true in the case of the poorer coal, so that only
a little of the inevitable increase in the price of all coals
will throw the economic balance in favor of the inferior
coal and any further general increase in cost of coals
will steadily increase the relative economy of the fuel of
less heating value — the saving increasing progressively.
38
We are glad to see our friends of The Locomotive place
the stamp of disapproval on the horsepower as a unit of
boiler capacity (see pa^e L75). In 1876 a committee of
eminent engineers appointed to conduct, a competitive
test of the boilers at the Centennial Exposition decided
upon the rate of evaporati f 30 pounds per hour from
feed water of 100 degrees Fahrenheit and at TO pounds
gage pressure (barometer unknown) as equivalent to one
horsepower, this being considered about the rale at which
a boiler would have to steam per horsepower developed
by the average engine of that time, under average con-
ditions.
At the time and at the best it was only the crudest
kind of an attempt to correlate the capacity of the boiler
and that of the engine, for there were then many engines
which required less than 30 pounds of steam per hour
per horsepower. Today, with boilers evaporating two or
four times as much water per square foot of heating sur-
face and engines requiring only one-half as much steam
per horsepower, then' is a wide and variable discrepancy
between the horsepower of the boiler as determined by
the Centennial standard and that of the engine or tur-
bine which if can supply with steam.
How should boilers be bought, sold, and classified —
by the amount of steam which they can make per unit of
time, or by the number of square feet of heating surface
which. they contain, or how? The horsepower ratine- js
supposed to be a statement of the rate at which the boiler
can make steam, but is in the awkward unit of 34.5
pounds per hour at the standard condition of "from and
at 212 degrees." If one wants a boiler which will make
IliS
POWER
Vol. 41, No. 5
the equivalent of -'1000 pounds of steam per hour from and
at 312 degrees, he says: ":!000 -f- 34.5 = 90, about.
Give me a 100-horsepoweT boiler."
And then the boiler maker says: ""Ten square feet per
horsepower — give him 1000 square feet of heating sur-
face.'' So the thing gets down to a heating-surface basis
after all. notwithstanding the fact that the evaporation
per square foot of beating surface may vary from 2 to 10
pounds, according to the amount of grate surface supplied
with it and the rate at which the coal is burned.
Another basis for rating is the amount of beat which
the boiler can absorb per hour. To evaporate 31.5 pounds
of water from and at 212 degrees requires 34.5 X 970.J
= 33,478.8 B.t.u. A kilowatt is equivalent to, say 3415
such units per hour. Messrs. II. <i. Stott and Ilavlett
O'Neill suggest thai the capacity to absorb 34,150 B.t.u.
per hour be taken as the unit of boiler capacity, and that
this unit be called a "myriawatt," signifying 10,000
watts.
We do not see that this improves matters much. There
is no such definite relation between the kilowatt and the
number of pounds of steam that it takes to make one.
as to warrant the use of an awkward five-place divisor,
and it simply means tricking out the old boiler-horse
power in a new regalia of metric trappings and contin-
uing it upon the stage.
Should we -"get the hook" for it "r If so, when we
are describing a plant with four 300-horsepower boilers,
shall we say •"four boilers of :!000 square feet of heating
surface each," '"four boilers capable of evaporating 9000
pounds of water per hour each" — or what?
:*:
Tlhte FiracftHcavl MsvEa's Boiler Test
Two methods of conducting boiler tests arc now gen-
erally aeeepted — one according to the short eode of the
A. S. M. E. and the other based on the more elaborate
standard code. The first contains about forty items,
leadings or calculations for which are necessary, and the
complete code contains over one hundred. Condensed
and standardized as are the calculations anil complete as
is the information gained by following these codes, a
boiler test is not simple, but requires considerable prepar-
ation and care and consumes much time. Furthermore,
when accomplished, the test is rarely typical of actual op-
erating conditions. As a means of establishing a record,
or standard, to be striven for by the operating force it is
exceedingly valuable, hut as a reliable record of efficiency
of average operation and a true gage of the economy of
the plant, it leaves much to he desired. What is required
is a continuous record to show the true efficiency of the
plant at all times, a "practical man's boiler test." and a
test that the boiler operators can easily comprehend — a
test with the results continually before the fireman.
It is neither fair to the boiler-room force nor conducive
to the best results to blame it for wastes after they have
occurred — especially After they have been going on for
some time. The time to call attention to them is while
they are occurring. The boilermen should know the in-
stant that the boilers commence falling below require-
ments, and this can be realized only when simple and
continuous records are provided for their frequent in-
spection.
The apparatus required is neither very complicated
nor complex. All that is needed are some automatic de-
vice for recording the amount of water fed to the boiler
ami means of weighing the coal as fired. Automatic fir-
ing simplifies the keeping of records of fuel consumed.
lui t even when hand firing is employed, satisfactory rec-
ords can lie kept by weighing the fuel — practice will soon
enable a competent fireman to accurately ^;i:r his fu< I
consumption in reference to his boiler feed. Pounds
of water evaporated per pound of fuel is all that really
matters, and the greater this ratio the better the boiler
efficiency. Automatically recording pyrometers, CO. re-
corders and temperature records of feed, etc.. all assist in
discovering the reasons for falling off of boiler efficiency,
hut the vital records are those of fuel consumed and water
evaporated while maintaining steam pressure.
Careful boiler tests should he made from time to time.
hut more to fix the standard of operation for the boiler-
men than for any other reason. The "practical man's
boiler test" should he a continuous operation in any boiler
plant making claim to efficient operation. It alone can
lead to economic operation, it alone is fair to the boiler-
man, and it alone shows whether the tires are kept in good
condition and how carefully and systematically the heat-
ing surfaces are freed from soot. etc.
>sifiiraf» (?) I£.EagpiEae@E'
Wheu we say "loafing," we have in mind the man
whom the employer generally finds sitting in the old easy-
chair reading a technical or trade journal or just smoking
his pipe. Of course, everything is clean about the plant
and the machinery is running smoothly, but there can
sometimes he detected in the employer's face a look of
dissatisfaction, lie is paying his engineer a good sal-
ary and cannot see that the latter is doing any work and
seems to think that he is not getting value received for
his money, for a cheaper man could hold down the "Old
Armchair" just as well.
This is a view taken by a great many employers and
is altogether wrong. The very fact that the engineer
finds time to ''loaf" and that the owner is not annoyed
by frequent shutdowns should he sufficient to convince
him that the engineer is a good man and has his depart-
ment in perfect order. Look out for the engineer that is
constantly rushing wildly about with greasy clothes and
smutty face and a handful id' tools, for unless his plant
is dving of old age, there is something wrong with the
man.
The employer who wants a man to build boxes, mow
the lawn, look after the roofs and a few other "little
things" to keep busy, is not looking for an engineer and
will seldom get one. and when something unforeseen and
leal annoying, like a wrecked engine or bagged boilers.
happens, he generally gets about as much sympathy as he
deserves.
08 Soma© ©rB^iEaal Hdles-s "
When we called for accounts of stupidity, in our i<suo
before the last, under the heading. "Just for Fun." we
-farted something, for we have had a deluge of them.
Evidently, nearly everyone has a stock of such stories up
his sleeve. We can use but a few of the hist, a- we said.
but if our readers do not mind sending them in, in spite
of a long chance that they may not be printed, we do not
mind reading them over to see if they are available.
February 2, 1915
I'll \Y E U
169
" iNllllimim i'i ! ' i mi i:iii;riii:u:i!iiiiiiii mi. iiimi mi , . . , miiilllllimiliwimmllllllllfe
CorrespoinidleinicD
.
In the issue of Dec 22, page 889, E. II. Clark asks
what the trouble is with the ash ejector. I believe
if he will increase his steam line to 1 Y> or 2 in., ami
then, instead of a bell nozzle, use a throttling nozzle
having a diameter not over % in., he will have no further
trouble with the construction as shown in the illustration
referred to.
The nozzle should be about even with the back edge of
the hopper opening. The ejector will probably work
a little better if the end of the li-in. pipe is left open
where the live-steam pipe enters. If closed at all, the
a lea should equal an opening 'i\/-> or -I in. diameter.
F. F. JoHGENSON.
Gillespie, 111.
It is surprising bow many have trouble when trying to
pump water at 210 deg. F. or over. To do this success-
fully, the pump should br able to deliver the maximum
quantity of water at slow speed and the water-supply
should be at least :!0 in. over the discharge valves, for the
reason that if a vacuum is created in the suction pipe,
some of the water will flash into steam ami till the water
Pobms of An; Chambers fob Suction Pipes
cylinder with vapor. Although it takes 212 deg. F. to
boil water under atmospheric pressure, or 14.1 pounds, in
a vacuum it will boil at a much lower temperature.
It is a good idea to place an air chamber in the suction
pipe, as shown in the illustration. The discharge air
chamber should he kept three-quarters filled with air; a
glass gage will show the water level at a glance. Should
the air get away, the chamber can be recharged by admit-
ting air into the suction line.
A sight-feed lubricator should be connected to the steam
pipe above the throttle valve, but a mechanical lubricator
may be connected below the throttle valve if desired. If
an automatic governor valve is used it should be placed
above the throttle valve, but a chronometer governor valve
should be placed below the throttle and the oil should pass
through them in either case.
It pays to use good packing, which should be soaked
in warm water before being put in the piston: the joints
should not he in line or the packing follower-bound. It
is. unnecessary to subject the rod packing to great pres-
i'111 ii II ii'iiii'iini iiiiiiiiuiiii i i 'ii minimi minimim I mm tr-
sure ; it is better to repack than to continue to tighten the
gland. It will be found with these precautious that hot
water is no more difficult to pump than cold.
Thomas J. Uogkks.
Jersey City, N", J.
'*.
In a vacuum steam-heating system that requires no
jet water at the vacuum pump, the air-separating tank
should not be equipped with such auxiliary appliances as
a float-controlled inlet and outlet valve, gage-glass, over-
flow pipe and handhole. A large tank, with these appli-
ances, is necessary only where jet water is used, because
the operator may use more jet water than is required for
boiler feed, causing it to flow through the heater into the
sewer. This would tax the heater beyond its proper
capacity and reduce the temperature of the boiler feed.
Therefore, an automatic valve is placed between the tank
and heater, so that the tank will overflow to the sewer and
not flood the heater when excessive jet water is used
T. W. Reynolds.
New York City.
ace
Our experience with concrete as a furnace lining with
underfeed stokers was not satisfactory. The concrete was
made of cement and gravel which ranged in size from
sharp sand to pebbles the size of a hen's egg in proportions
of about 1: !. The old firebrick side walls were taken
out, the walls cleaned and thoroughly wet, the concrete
was poured in place in forms, in the usual manner, and
allowed to dry several weeks before the boiler was put
into service. As a means of comparison, another furnace
was relined with firebrick at the same time. These
furnaces are subjected to bard service, and the clinkers
stick to the side walls so that it is necessary to use a
sledge and chisel bar to remove them, and more damage
is done in this way than by the (ire. The concrete walls
did not stand as well as the firebrick and the clinkers
gave about the same amount of trouble.
Concrete has one important advantage, however, in
that it is less expensive to put in, but even if allowed to
become thoroughly dry, and heated up slowly, it will
give some trouble from cracking and falling out,
although this may be prevented by reinforcing it with
expanded metal or rods. In our ease it was tied in one
place only, and perhaps more experience would have
produced better results. Oyster shells used as a flux
prevented clinkers sticking to the walls to a great extent.
Two or three scoops of these shells were thrown in next
to the walls on each side after cleaning the fire. I believe
that it was the lime in these shells that did the work,
and crushed limestone would probably do the same.
•See also page S40, Dec. 15, 1914; page 62, Jan. 12, 1915, and
page 1.31, Jan. 26, 1915.
no
FOWE R
Vol. II, No.
I find that there is a great difference in firebrick and
fireclay, and also in the workmen that build the walls.
It is customary in our plant to have this work done by
contract, with a guarantee that the work will last one
vuar. One contractor had to rebuild his walls twice
during the year, and another put in a wall that was not
tied to the outside wall, and it fell out in less than a
month. A third put in a wall that did not require any
repairs during the year. Good material should be used,
and it is essential that it be tied solidly to the outer wall
;ii every fifth course by a header tied into the outside
wall, and if subjected to hard usage the headers should
be placed every third or fourth course. The fireclay
should l>c mad.- very thiii and the least possible amount
used. The brick should be dipped in it and rubbed to
a tight lit to make a firm bed. so that there is no chance
for the mortar to chink out and let the brick fall down.
In arches the proper wedge and skew brick should be
used to get the proper are with a full hearing the entire
length of the brick without resorting to fireclay to
doit.
J. C. Hawkins.
TTyattsville, }fd.
S^feSy ism HacadlMiagg RefftHijjgeE'S'E&fts
An editorial in the Dec. 15 issue comments on New
York City's refrigerant regulations. The regulations
appear in the same issue as does comment on them by
members of the American Society of Refrigerating En-
gineers.
There should be, as the editorial points out. widely
adopted rules for the safe operation of refrigeration
machines, as there are for boilers and steam-driven ma-
chinery. In this city (Chicago) the laws governing
steam apparatus are strict, but nothing is said of high-
pressure gases or air.
As the water here is exceptionally good for making
raw water ice, there are many motor-driven ice machines,
and some of them are operated by men who are not li-
censed engineers. For the heating system in such plants
low-pressure steam or hot water can he used, so that the
board of examining engineers has as yet nothing to do
with them. Surely there is danger in these motor-driven
ice plants even though there are no high-pressure steam
boilers. Such plants are often located in thickly settled
residential neighborhoods, close to schools and churches.
The license law should cover all apparatus carrying
pressure, whether steam, gas or air. Regular inspection
should be made and none but competent men allowed to
operate. There is without doubt less chance of danger
ously high condenser pressure with a motor-driven unit
than with steam drive. Increased pressure will cause the
circuit-breaker to trip or a fuse to blow, whereas a steam
engine will keep going until something gives way Bui
again, circuit-breakers may be tampered with or even
blocked in and heavy fuses used by some who do not rea-
lize the danger.
Top safety valves are good in some ways, but some-
times they are both a nuisance and a danger. It is, as
Mr. Fairbanks remarked (Dec. L5 issue, p. 866), almost
Impossible to get an ammonia safety valve that doc- not
leak. When once il opens it seldom scats tight again
until it has been taken apart and cleaned of the grayish
powdery sediment which has collected. Rather than shut
a compressor down in a rush season, many engineers will
plug the valve so as not to lose the ammonia.
If the outlet of the safety valve is piped into the suc-
tion side of the compressor, it might leak a little all the
time and so cut down the efficiency of the machine.
Again, if the outlet is piped into water or to a high point
above the building, there can easily be a constant loss of
ammonia. In one plant the safety-valve outlets of a
number of ammonia compressors were piped into a
header, and this extended high above the building. The
continual loss of ammonia was finally traced to this man-
ner of connection, and the header was done away with
and the valves allowed to discharge into the engine room.
This often proved a source of annoyance when starting up
a compressor which had been down so long that liquid
had collected in the discharge line. The valves nearly al-
ways opened until the discharge line had become cleared
of liquid. In the case of a large direct-expansion system,
when a small slug of liquid was palled into the com-
pressors the valves would often open. In another plant
two different suction pressures were carried on several
compressors. When one compressor could be spared from
the high back pressure, it would be changed over to the
low. and often while this change was being made there
was loss of ammonia and inconvenience to the men owing
to the pop valves opening.
In the foregoing case* the safety valves were a nuisance
and were really not necessary. Whether or not a pop
valve is the proper thing on an ammonia compressor is
a question hard to decide. These valves will relieve a
compressor or condenser of over-pressure, it is true, hut
mo*t engineers will know of the increasing pressure with-
out having the engine room filled with suffocating gas or
losing much ammonia. The sound of the machine,
whether motor or steam driven, will be warning enough
to any competent man. An engineer should be near
enough to hear his machinery, or if he should have to go
away he should have a man in the engine room who knows
enough to shut down in case of accident.
There are not many things liable to happen that will
cause a sudden rise in the condenser pressure. Shutting
off the water from the ammonia condenser will not cause
so sudden an increase of pressure that there is not plenty
of time to slow down or stop the compressor.
Anv cross-connection between a hot and cold water-
supply should not be allowed on pumps supplying a con-
denser with water. Such a connection can and has caused
trouble, but with proper inspectors such cases would be
lew. Another cause could be the breaking of the suction
line. This Mould allow the compressor to draw in much
air, but with an operator within hearing distance he
would have plenty of time to shut down. One other cause
of dangerous pressure — and in this ease I do not believe
a safety valve would do much good— is the sudden clos-
ing of a valve on the discharge line between the compres-
■■>r and condenser. This can hardly happen unless an
angle or globe valve had been put in the discharge line
with the pressure side of the disk toward the condenser.
In that ease the disk might come oil' and suddenly close
the discharge: the shock would rupture something. But
as in other cases proper inspection would minimize the
chance of such a condition.
If a safety valve opened directly into a small engine
room, the charge of ammonia would probably be lost as it
would he impossible for a man to shut down the machine
February 2, 1915
POWE 11
1V1
unless provided with a helmet. A positive device for
shutting down the compressor when the discharge pres-
sure reaches a predetermined point is safer. Such de-
vices are in use in sonic places and work well. Each has
a connection from the discharge line to the engine gov-
ernor, and when the pressure goes to the point at which
this control is set the governor acts and the engine is
shut down as if the governor belt broke. Such a device
can he tried daily or weekly and kept in proper working
condition. A safety valve on an ammonia line or con-
tainer cannot he tried occasionally like one on a steam
boiler, to guard against its sticking when needed.
Proper check valves should he placed in both suction
and discharge lines of compressors so that in case of a
bursting cylinder the gas will he shut oil'. It is seldom
that a serious accident occurs from over-pressure during
the operation of an ammonia compressor. When the pres-
sure gets too high it will blow out a gasket in the sys-
tem or perhaps split a pipe in the condenser. What
really causes serious accidents is the dropping of a broken
suction valve into the cylinder or something breaking on
the piston which will knock out a compressor head. For-
tunately, this does not happen often.
Internal explosion in the discharge receivers and the
oil separators occurs from permanent gases or inferior
lubricating oil which becomes ignited when a high dis-
charge temperature is maintained. The proper oil and
care in keeping non condensable gases out of the system
and a correct discharge temperature will do away with
the possibility of such explosions.
It is common practice in most new installations to
test the high-pressure side with air at :500 lb. and the low-
pressure with 1 50 lh. air pressure, and once a year in old
plants after the winter overhauling. This is particularly
dangerous in motor-driven compressors where the speed
is constant. The air discharged by the compressor reaches
a dangerous temperature when the gases from the oil and
ammonia mix with it. As several bad ruptures have re-
sulted from this cause, the use of a small unit built for
testing purposes should be insisted on and the tempera-
ture of the system kept low to insure safety.
Another noticeable neglect in the ammonia system is
the lack of suitable hangers for coils and pipe work. In
direct-expansion systems the coils on the walls and ceilings
of some rooms become so heavy with frost that the hang-
ers give way and allow the coils to fall and break. This
can also happen on suction lines not covered and allowed
to accumulate frost. There should he proper means of
supporting all coils and lines, and care should be taken
for the regular removal of frost.
Electrically operated valves are valuable in most plants.
In case of accident the machines could be shut down and
the ammonia cut off from a point outside the building
by means of switches. Discharging ammonia into water
or into the atmosphere in case of accident has its dan-
gers in a large plant unless there is a river or lake near-
by. Some other way of disposing of a large charge of
ammonia must be found.
The adoption by the City of New York of a set of rules
for the safe operation and proper inspection of all ma-
chinery handling high pressure should be and most likely
will he the beginning of improvements in the ice-machine
business. Competent men to operate and inspect the
plants would make them safe.
Chicago, 111. A. G. Solomon.
Savasa^ aim ftlh© P^flmap Rootnra
The idea that the greatest possibilities for improvement
in economy are to be found in the boiler room seems to
be generally accepted. This story, however, is to show-
that leaks of some magnitude may be found in the pump
room.
On taking charge of the plant, the new chief had certain
8Usp'",-ons as to the cause of the low feed-water tempera-
ture. As soon as possible he placed a recording thermome-
ter in the (red line. The first chart coiilirmed his suspi-
cions and an investigation disclosed several interesting
items. The feed-water heater was of the open type, to
which condensate from various heaters, driers, etc., was
returned.
The overflow pipe was connected without an opening
and concealed the excessive waste of water. The new chief
cut the pipe and put in a funnel (shown by dotted lines in
Overflow Changed
the illustration) and it was observed that for a time a
stream of hot water would pour from the overflow — then
the makeup valve would open wide. It was evident that
water was coming hack in slugs, showing that the receiver
capacity of the heater was not sufficient for these condi-
tions. Much hot water was being wasted to the sewer
at times and a large quantity of cold makeup water was
called for at others.
More capacity was at hand in the shape of an old re-
ceiver, which had been used up to the time the heater
was put in. It was still connected up for an emergency
so that it was only necessary to combine the two and
maintain a constant level in the heater and waste no hot
water through the overflow.
The makeup valve was moved from the heater to the
receiver and set to operate only when that vessel was
nearly empty. At first it was needed, but now it has al-
most gone out of use. The main bearings of the big en-
gine were water-cooled. This water had formerly been
wasted to the sump pit and then lifted to the drain by an
ejector. The chief piped this, together with the jacket
172
P 0 W E R
II, N.i.
water, from the air compressor to the receiver. This
nearly equals the amount of makeup water needed.
The average temperature from a week's charts among
the first was 140 deg., ami from the latest it was 212 deg.
These two sets were turned over to the manager, together
with a statement of the monthly coal hill. Where the
coal formerly cost in excess of $3000, there was now
a saving of about $200. As a saving it interested the
manager ami he actually offered the chief words of praise
— but nothing more.
William E. Dixon.
Cambridge, Mass.
I read in Power. Dec. 22, page 890, of using a steam-
separator drain as a supply line for a pump. This is
very good as regards the engine, but how aboui the pump?
I think a mucb better way would he to repair the trap
or install one that would work, rather than run this wet
steam to the pump, for if only one pump is on the line,
and that is shut down while the engine is running, all
the condensation must go through the engine. As water
is had for an engine cylinder, as every engineer knows,
will it not do damage to the pump also? The1 pump is one
type of engine.
I have seen plants where every precaution was taken
to insure dry steam for the engines, yet all the steam for
auxiliaries was taken from the lowest point in the steam
main without a separator. Th s?e was mucb complaint
about the amount of oil required by these pumps. A
pump is a wasteful thing at best, and 1 cannot see where
there is any economy in supplying it with wet steam. If
there is some good reason for this I would he glad to
learn of it.
Edward Hoesfeld.
New Brighton, Penn.
WSao Qe&s &lh\@ Firoinaoftaoini?
The Foreword in the issue of Dec 15 is indeed a prob-
lem if sentiment is allowed to enter into it, assuming that
the promotion is to he to that of chief engineer and the
three candidates to he watch engineers. Only one candi-
date has made any special effort to fit himself for the po-
sition ami is therefore entitled to it on a strictly busi-
ness basis.
The one on the left is popular with Ids mates, a hustler,
observing and is liked by the manager, and expects to
slide into the job. Being popular with a number of men
is no guaranty that he can handle those same men. He
will not he taken very seriously, and if he changes his at-
titude to une of authority they will resent it. Being a
hustler is not an essential quality in a chief engineer. His
task is to devise ways and means to operate the plant
economically and efficiently. His observations are of
little value if he lacks the technical knowledge to decide
their true significance. The manager has no right to
consider his likes or dislikes.
The center candidate is steady, sober and honest,
which is probably the reason he has seen long service.
Seniority without any indication of ability is no reason
I'm- promotion. TTe has made no effort to lit himself for a
better position, therefore has ][l) right to expect promo-
tion. Lacking in ambition, it is not reasonable to sm>-
pose he will make an efficient chief. lie hopes to fall into
the position.
The candidate on the right is qualified in every way,
and being a student will he progressive, lie, however, is
grouchy and will probably have labor trouble; hut if the
manager understands the principles of cooperation he can
explain to this man the effects of grouchiness on the men
under him. It is only reasonable to suppose that a man
who has the ambition and perseverance to lit himself for
the job in every other way will also overcome this fault
when he is made to see how objectionable il is. lie is the
only man who deserves the position; he is trying to climb
into it.
S. II. Farnswortk.
Chicago, 111.
[The foregoing assumes one change is to he made:
eliminating a fatal error and substituting a desideratum.
Suppose the others to he similarly treated? — Editor.]
Sivjj§fg?esft©(dl
Electricity as sold is usually dependent upon two fac-
tors— the full or maximum demand and 1 he extent or
hours of use of the demand.
The demand is the force applied in doing work, and the
electrical unit for measuring force is the kilowatt. It is
thus described in the A. T. E. E. Electrical Standards:
"Electrical power, which is the rate at which energy
is being transformed in a circuit,. is expressed by the prod-
uct of the instantaneous values of electromotive force and
current in the circuit. The practical unit is the kilowatt,
which is 1000 times the watt."
The amount of force or energy expended in doing work
is the product of the average force applied and the du-
ration of time during which the force is applied. The
electrical unit is the kilowatt-hour, described as follows:
"The amount of electrical energy transformed in a
circuit is measured by the product of the power and the
time. The practical unit is the joule, which is equal to
one watt-second, the watt-hour and the kilowatt-hour."
It may he found convenient in the sale of electric power
to charge on the hasis of the kilowatt demand alone, the
energy in kilowatt-hours consumed alone, or by a com-
bination of the two methods. Nontechnical men who,
through the nature of their business, happen to deal with
electrical matters often confuse these terms. The kilo-
watt and the kilowatt-hour, while directly related, have a
different significance, and the oversight or unintentional
dropping of the suffix "hour" may create a serious and
perhaps costly misunderstanding.
For the best interest of the electrical business it seems
that an appropriate substitute for the term kilowatt-hour
is highly desirable, and it is fitting that the units of quan-
tity of energy he designated as "kelvins," in distinction
of the memorable work of Lord Kelvin. This thought
had its inception at the last International Electrical
Congress and was at thai time recommended for adop-
tion and, not unlike the appeal for the substitution of the
term myriawatt for boiler-horsepower (although of a
somewhat different application), should receive the in-
dorsement and support of the entire electrical industry.
Pittsburgh, Penn. \V. B. Wallis.
February 2, 1915 PO W El! 173
ijiunnuniiinniiiiiiinniniinnniinniiiiiinniiiiniiinnniiiiuinniiiinnuiiiiin mill Mill mini n nun mi inn n iiiiiiinii i iiiiiiini un nm limn i i imiiiii in iiiiimu iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii.il |
.imgEiniee^
>tknd
mn
nniiiiiiiiiiiiniiiimmiiiNif
The series of thermal and mechanical operations
through which the working medium of a heat engine
passes is called its cycle. The actual cycle of any working
engine has back of it an ideal scheme of operation under
which the greatest possible proportion of heat could be
converted into work. Between ideal and actual perform-
ance there is a gap due to secondary losses resulting from
imperfections of the real machine.
The essential parts of the ideal cycles of the common
i\ pes of engine, with both steam and gas as working med-
iums, are as follows :
1. Eeception of heat at high temperature or over a
high range of temperature.
2. Lowering of temperature by adiabatic expansion,
in which no heat is given to or taken from the substance,
so that it performs work at the expense of it- initial store
of heat energy.
3. Rejection of heat at low temperature or over a low
range of temperature.
4. Raising of temperature to the starting point by
adiabatic compression, in which the work done upon the
substance adds itself to the initial store of heat energy.
Looking at the matter from the side of thermal action.
the simplest case is that in which heat reception occurs
at some uniform high temperature and heat rejection at
some uniform low temperature. The resulting combina-
tion of two isothermal (constant temperature) and two
adiabatic (no heat transfer) operations constitutes the
well known Carnot cycle, which is. thermally, the simplest
possible scheme of working. If r, is the absolute temper-
ature of heat reception and T2 the absolute temperature
of heat rejection, the efficiency in heat conversion is
*~ T}
This means that the quantities of heat received, con-
verted, and rejected are respectively proportional to Tlt
T, — T., and T2.
Fig. 1 is a true representation, laid out to scale, of
the performance of one pound of air as medium in a
Carnot cycle, when working from 2000 to 1000 deg. abs.
F.. or from 1510 to 510 deg. F. The pressure limits are
from -150 to 15 lb. abs. per sq.in. The purpose in giving
it is to show how utterly impractical this cycle is as an
Underlying scheme for a gas engine. The faults are. first.
a very weak variation of pressure from the beginning of
the stroke at .4 to the end of the stroke at C; secondly and
especially, the vertical narrowness of the inclosed diagram
ABCDA coupled with the high total pressures prevailing,
as measured above the base line OV. The small mean
effective pressure will require a large cylinder for a given
power, and the big total pressures will call for a strong
and heavy machine and will cause large losses of power
through machine friction. Further and finally, iso-
thermal operations could not well be secured with any
scheme of internal combustion. The alternative of treat-
ing a gaseous medium like the water in a boiler, and sup-
plying heat through a metal wall from an external fur-
nace, has been tried out in the hot-air engines. While
not impossible, this plan is of little value practically.
But with steam, as laid out in Fig. 2. the Carnot cycle
becomes of distinctly usable' form. This is because
stant pressure goes with constant temperature in the iso-
thermal operations of evaporation and condensation. The
description of Fig. 2 is a- follows:
p
Km
Volume, Cu.Ft.
Carnot Cycle foe One Pound of Am
Volume, Cu. F+.
Fig. 2. Carnot Cycle fob One Pound of Dry
Saturated Steam
Fig.
0 5 10 15 20
Volume. Cu.Ft.
Rankine Cycle for One Pound of Steam
from Fig. 2.
At A is represented the volume of one pound of wateT
at steam pressure and temperature. Line AB represents
the vaporization of this water and the admission into the
cylinder of the full volume of steam formed.
With idcil action there would be no loss of heat or
pressure in the steam pipe or engine valve and no abstrac-
174
P 0 W E R
Vol. 41. No. 5
Hon of heat by the cylinder walls. Of course, no ma-
terial exists of which the thermally neutral cylinder re-
quisite for such action could be made.
Curve BC shows adiabatic expansion carried down to
exhaust pressure and temperature at C. This continues
to require the imaginary nonconducting cylinder. To
supply heat for work done there is progressive conden-
sation of steam along line BC.
Line CD represents not so much the expulsion of ex-
haust steam from the cylinder as the decrease of volume
by condensation. This condensation is stopped at such
a point D that adiabatic compression of the whole charge
tion with fall of temperature from C to D. Operations 2
and 4 are adiabatic expansion and compression, as here-
tofore. In the actual engine the heating at constant
volume is pretty well realized. The would-be adiabatic
operations are strongly modified by cylinder-wall action,
which is strengthened by the water jacket. The ideal
cooling at constant volume from C to D is approximated
in mechanical effect by actual exhaust, no matter just
how the heat in the exhaust gases is really dissipated into
the atmosphere.
The Brayton cycle. Pig. 5, in which heating and cool-
ing take place under constant pressure, is of little prac-
Yolume, Cu. Ft.
Fig. 4. Ideal I >tto
Cycle
Fig. 5. Bbatton Cycle, Used
ix Gas Turbines
Fig. u. Die>el
Cycle
of the water-steam mixture will bring it to the initial
>tate at A.
Xow the real cycle of the steam plant conforms to this
scheme as closely as actual conditions and materials will
let it, with but one exception. This one essential depart-
ure lies in the absence of any attempt to raise the feed
water to steam temperature by adiabatic compression.
Instead, the steam is all condensed, and the resulting
water or an equivalent fresh supply is pumped into the
boiler.
Modified thus by the omission of adiabatic compres-
sion, the Carnot cycle of Pig. 2 becomes the Rankine
cycle of Fig. 3. This i- the ideal scheme of working which
lies back of the actual performance of the steam plant
with either piston engine or steam turbine. Such an en-
gine as the direct-acting .-team pump falls far short of
the ideal output of work per pound of steam. Good plants
rom 65 to ?•"> per cent, of ideal performance.
Working according to the Rankine cycle, an ideal
steam plant would get more work from a pound of steam
than if on the Carnot cycle, hence would require fewer
pounds of steam per horsepower-hour. But the heat re-
quired to make a pound of steam increases more rapidly
than the work output, so that the Rankine-cycle efficiency
is lower.
It is to be borne in mind that the line AD at the left-
hand edge of ] i"t identical with the axis line OP.
The distance between them is the volume of the pound of
water, and operation Xo. 4 is performed by the feed
pump. Of course, this operation no longer conforms to
meral description in paragraph "2.
Turning now to internal-combustion engines, the cycle
most used is represented in Fig. I. This is in true pro-
portions fur certain assumed data, with one pound of
gas mixture. The dotted outline shows approximate di-
mensions of the real ilia-ram. Heat reception
place with rise of temperature from .1 to /-', heat rejec-
tical interest as regards use in piston engines. It is, how-
ever, the cycle of nearly all the attempted gas-turbine
plants. In the latter there are necessarily two distinct
pieces of apparatus — the compressor, whose operation is
represented by diagram DAEFD, and the turbine, with
diagram EBCFE.
The Diesel cycle. Fig. 6, calls for little comment. Its
heat reception is nearly at constant pressure, although
a short isothermal section EF is sometimes assumed as a
part of the ideal diagram.
The ideal cycle, with its output and efficiency, is not
nearly so much used as a standard of comparison for the
Fio. T. Cycle of Explosive Gas Tdbbinb
gas engine as it is for the steam plant. One reason is that
it is a much larger task to calculate, exactly, the dimen-
sions of an ideal gas cycle than tho>e of the Rankine steam
cycle. Roughly, if T, is the average absolute temperature
during heat reception AB, and T. the average tempera-
ture during heat rejection CD, the efficiency is. as per the
Carnot cycle,
T T
E = -J =-?
?\
Bui this is only a rough approximation; and a large
amount of mathematical work is needed to get an exact
value.
In the way of a comparison among these cycles, one
February 2, 1915
IM) W E It
i : 5
important point will now lie noted. From the side of
the machine (as against that of thermal action ) that cycle
is best and easiest to apply effectively in which the least
amount of work must be expended in getting the medium
up to its high pressure at the beginning of the working
stroke — at A in all except Fig. 4, ami in this figure at B.
The steam-engine cycle, Fig. 3, shows up best in this
respect, although its apparent advantage is partly neu-
tralized by compression in the cylinder. The latter is not
an essential part of the cycle, but one of the secondary
sources of loss, like cylinder-wall action, etc.
As between gas-engine cycles, the two-part operation
DAB in Fig. 4 is better than compression clear up to the
highest pressure along the curve l>.\ in Fig. •"> or DA in
Fig. 6.
The Diesel engine lias advantages which overcome
the handicap of excessive compression work. But this
handicap is a serious matter indeed for the gas turbine,
anil line of the chief reasons I'm' ils lack of success. It is
because of the smaller amount of compression work that
the explosive cycle, driving by pull's, has been employed,
as in the Holzwarth turbine (Power, Feb. 9, 1912, p.
191 ). This cycle is outlined in Fig 7, and the constant-
pressure line CI), as in Fig. 5 also, has the practical sig-
nificance that there is a longer range of expansion than
of compression.
octets ©f Heattimig' aimed
The twenty-first annual meeting of the American Society
of Heating and Ventilating- Engineers, held Jan. 19-22, at the
Engineering Societies Building, West 39th St., New York City,
was attended by 200 to 300 members and guests, and the
attractive program which had beeTi announced was carried
out in nearly every detail.
At the business session, held Wednesday afternoon, Jan.
20, reports of the secretary, treasurer and council were re-
descriptions of new plants, but little information as to their
operation or as to the costs of installation or maintenance.
I venture, therefore, to present an analysis of some data.
In 1912 two large factory buildings were erected, one in
Toledo and one in Detroit, and both were designed by the
same architects. The writer designed the heating equipment
for both plants.
The character of the construction is identical. There are
no basements, but there are some tunnels provided under the
first floors for air ducts, service pipes, wiring, etc. The build-
Annual Dinner of American Society of Heating and Ventilating Engineers
eeived and indicated that steady progress had been made in
the special field of the Society and that the ambition to in-
crease its membership to one thousand was not without
substantial encouragement.
PRESIDENT'S ADDRESS
In his annual address, Samuel R. Lewis, the retiring presi-
dent of the Society, urged upon the members the advantages
of following up the actual operation of heating and ven-
tilating plants, especially those of their own design, as in-
formation thus gained is highly beneficial in broadening out
personal experience and in establishing the relative merits
of different systems. Continuing, he said:
When the designing engineer has more to do with the
operation of the plants he designs, there will be an improve-
ment in design. I speak from experience, and believe that
this opinion will be shared by others who have had like
experience.
An examination of the Society's proceedings discloses many
ings are of reinforced-conerete construction, with solid con-
crete floors, mushroom type, and 12-in. brick curtain walls.
The glass is set in tight, steel frames extending practically
from floor to ceiling and from column to column. The ratio
of glass to exposed wall is approximately three to one. The
roof is of concrete-slab construction, with a cinder fill and tar
above.
The Toledo building is heated and ventilated by an all-
indirect system, equipped with automatic temperature and
humidity control, the humidifying being by means of steam
jets. There is no direct radiation whatever, except in a few
to'let and service rooms.
The Detroit building is heated entirely by direct radiation.
about one-half of the radiation being placed on the side walls
and one-half on the ceiling. Great care was taken, however,
in placing the radiation on the side walls to provide for a
liberal circulation of air behind it. The Detroit building has
no automatic temperature control, although good hand regu-
lation is obtainable by shutting off parts of the radiation.
Each plant is equipped with an efficient two-pipe vacuum
system. The Toledo plant is unique in its design to the
extent that the blast-heating surface is arranged at the bases
of the vertical Hues and so proportioned thai much the same
176
POWER
Vol. 41, No. 5
effei t is obtained every day as would be obtained by having
direct radiators in the various rooms, since gravity indirect
beating is always in effect whenever there is any steam in
tlie radiation. The theory in the design was that the Toledo
plant should be economical, comparing with direct radiation
by reason of this gravity effect, while not open to the ob-
jections inherent in direct radiation when placed against the
outside walls. These objections are that the direct radiation
interferes with the benches of the workmen, causes local
overheating-, and is not economical of fuel, since there is an
opportunity for a large amount of radiant beat to directly
• 'iter the outside wall without appreciably affecting the tem-
perature of the room. The air is handled by steam power,
and the cost of air handling is included in the fuel cost.
The Detroit plant, with its direct radiation, is, of course,
heated whenever supplied with steam. In March, 1914. in-
formation was received from the owners to the effect that the
heating plants had proven adequate and satisfactory.
A careful record was kept of the fuel consumed during
the season of 1913-14. The following data will serve for
comparison:
Toledo Detroit
With Ventilation No Ventilation
Exposed glass surface 39,520 sq.ft. 13, 9S0 sq.ft.
Exposed wall surface 7,904 sq.ft. 2,796 sq.ft.
Exposed concrete-column sur-
face 7.6S0 sq.ft. 3,600 sq.ft.
Exposed roof surface 45,880 sq.ft. 29.35S sq.ft.
Exposed ground-floor surface. 45. SSO sq.ft. 29, 35S sq.ft.
Contents 2,460,500 cu. ft. 704,592 cu. ft.
Floor area 178,800 sq.ft. 56,955 sq.ft.
Blasl radiation 12.9S3 sq.ft.
Direct radiation negligible 8,905 sq.ft.
Air delivered per minute 138,000 cu.ft.
Boiler capacity 500 hp. 125 hp.
Cost of coal per season $3,009.00 $952.00
Fuel cost for heating and
ventilating per 1000 cu.ft. of
contents per season $1.22 $1.35
Same per thousand sq.ft. of
floor space per season $16.82 $16.73
So far the evidence is favorable to a blast system as indi-
cating that a large, well built factory building can be heated
and ventilated with an efficient, all-indirect plant at less cost
per thousand cubic feet of space per season and for nearly
the same cost per thousand square feet of floor space per
season, as the other can be only heated bv plain direct radia-
tion.
The economy of the Toledo plant lies in the form of the
building; that is, the Detroit building, being but two stories
high, loses heat through the floor of the first floor and through
the ceiling of the second floor, whereas the Toledo building,
being four stories high, has two intermediate stories which
only lose heat around their sides. For this reason there is
advantage sufficient in the instance under consideration to
make a favorable showing for the blast system.
REPORTS OF COMMITTEES
The report of the committee appointed January, 1914, "to
prepare a set of minimum ventilation requirements for public
and semipublic buildings which the Society can recommend
for legislation," was received with interest.
General Statement of the Committee on Com-
pulsory Ventilation
A correct interpretation of the experimental work which
has been carried on in the last few years, relating to ventila-
tion practice, forces certain conclusions:
A. The necessity for adequate ventilation has been em-
phasized, although the relative importance of certain factors
has changed.
B. A high temperature, especially if associated with a high
relative humidity, is injurious.
C. The proper relation between air temperature and rela-
tive humidity should be emphasized.
D. Air movement in contact with the body materially as-
sists normal heat dissipation.
E. Air supply free from dust, bacteria and other contam-
inations is important.
In making recommendations for compulsory ventilation
laws it is believed that the importance of the following re-
quirements has been amply demonstrated:
1. A minimum allotment per person of floor and air space,
based upon the nature of occupancy.
2. A quantitative minimum air-supply requirement.
3. A carbon-dioxide test for determining the quantity of
air supply and its distribution.
4. A temperature-range limitation.
5. The removal from the air of injurious substances aris-
ing from manufacturing processes or other causes.
6. Air-exhaust requirements for special service rooms
{toilets, locker rooms, etc.).
7. Definite requirements regarding the drawing, filing and
approving of plans for both new and existing buildings in
which ventilating equipments are to be installed or changes
in the equipment made.
8. Ample authority to enforce the law without recourse
to civil action, and with sufficient operative and financial as-
sistance to care for the clerical, field and technical details
incurred by such enforcement.
9. The official body charged with the enforcement of such
laws shall have authority to promulgate specific rules and
regulations covering details of installation and operation not
included in the law. Such rules and regulations must not con-
tliet with the full intent and meaning of the law. (A few
such rules are appended to the report.)
The committee decided that it would be impracticable to
attempt to draft a model ventilation law with the necessary
legal phraseology, as this would require the assistance of an
attorney, and would, moreover, call for an extensive building
classification which could not be satisfactorily used in the
various states, cities or towns where building laws and regu-
lations based on other classifications are now in force. The
committee submitted, first (under Section I), the specific report
covering general suggestions for minimum heating and ven-
tilation requirements that are applicable to all classes of
buildings, and secondly (under Sections II, III and IV), sep-
arate sets of more definite requirements for schools and col-
leges, factories and theaters.
Sections II, III and IV cover three very important classes
of buildings which are often the subject of separate legisla-
tion. Many other classes of buildings, such as department
stores, hospitals and similar institutions, churches, restaurants,
police stations, jails, bakeries, laundries, etc., for which the
requirements for heating and ventilation are covered by care-
ful interpretation and use of Section I, would be benefited by
separate sets of requirements. It was also pointed out that
suggestions from the Society, covering practical requirements
for the heating" and ventilation of street cars and some other
public conveyances, are desirable, and that the report could
be considerably enlarged to cover these subjects.
The committee strongly urged that educational and co-
operative methods of improving heating, ventilation and san-
itation conditions be studied, and used as far as possible in
addition to compulsory methods.
Various members of the Society and others had assisted in
the compilation of these recommendations, and the informa-
tion had been cheerfully given when available. The com-
mittee also reported that acknowledgments were especially
due to investigations and recent committee reports concern-
ing the work in New York City and to the ventilation code
and experience in the City of Chicago.
The General Suggestions, Section I, of the Committee's Re-
port, applicable to all classes of buildings, to be provided and
maintained during occupancy in all rooms and all inclosed
spaces in all classes of buildings, are summarized as follows:
Article I — Space per Occupant (minimum requirement) —
Schools and colleges — class, study, lecture and recita-
tion rooms, floor area per occupant in sq.ft 15
Schools and colleges — class, study, lecture and recita-
tion rooms, cubic space per occupant (volume divided
by number of persons) in cu.ft ISO
Primary schools — class and study rooms (pupils under
8 years of age), floor area per occupant in sq.ft 12.5
Primary schools — class and study rooms (pupils under
S years of age), cubic space per occupant in cu.ft... 150
Theaters, auditoriums and courtrooms, floor area per
occupant in sq.ft 6
Theaters, auditoriums and courtrooms, cubic space per
occupant in cu.ft 90
Factories, manual-training rooms and other workrooms
— floor area per occupant in sq.ft 25
Factories, manual-training rooms and other workrooms
— cubic space per occupant in cu.ft 250
Minimum space conditions in all classes of buildings or
rooms not tabulated shall be reasonable and practical and
shall meet the approval of the Department of Health.
Article II — Air Supply (minimum requirement) —
Sufficient outdoor air shall be provided for all occupied
rooms or inclosed spaces at all times during occupancy, as
may be necessary to meet the requirements of Articles I to
XI, inclusive.
The supply of outdoor air for the following classes of
rooms shall be positive and based on a minimum quantity of
cu.ft. per occupant per hour as tabulated:
Class, study, lecture and recitation rooms in all schools
and colleges, cu.ft. per occupant per hour 1S00
Courtrooms and auditoriums 1500
Theaters 1200
Factories, manual-training rooms and other workrooms 1500
All air supply for ventilation must be from an uncontam-
inated source of air from which the dust or other impurities
shall be sufficiently removed by washing or otherwise.
Article III — Air Distribution —
The distribution and temperature of the air supply for
ventilation shall be so arranged as to maintain the temper-
ature requirement, as stated in Article IV, without uncom-
fortable drafts, or any draft lower than 60 deg. F., and as a
test of proper supply and distribution it shall be required
that the CO; content shall not at any time exceed 10 parts
in each 10,000 parts of air, based upon tests taken in a zone
from 3 to 6 ft. above the floor line in the occupied spaces.
This requirement may be modified by the properly constituted
authority as applying to breweries, water-charging rooms or
other rooms where carbon dioxide is liberated in manufac-
turing processes.
Note — While carbon dioxide in the air, in reasonable quan-
tities, is not considered injurious to health, its presence in
occupied rooms is an acccurate measure of the air supply
and distribution if no other source of carbon dioxide is pres-
ent except the occupants of the room.
Article IV — Temperatures —
The temperature of the air in occupied rooms in all classes
of buildings, during the periods of occupancy, shall be not
less than 60 deg. F., nor more than 72 deg. F., except when
the outside temperature is sufficiently high that artificial
heating in the building is not required, this requirement not
to apply to foundries, boiler or engine .-ooms, or special rooms
in which other temperatures are required or advisable.
Articles V to XIV provide suggestions pertaining to regu-
lations on the subjects of sources of heat: removal of dust.
February 2. 1915
POWEE
i;;
fumes, gnscs, vapors, odors, fibers or other Impurities; pre-
vention of excessive temperature and humidity: ventilation
eial-service rooms; ventilation of toilet rooms: ven-
tilation of cellars, basements and spaces under buildings;
authorization to require special ventilation; tiling of plans;
investment of officials with the right to inspect premises;
authorization of officials to close premises after noncompli-
ance with regulations and due notice.
A report was submitted by the committees on the Devel-
opment of Heating and Ventilating Industrial Buildings, and
progress was reported by other standing committees.
In a bri f paper presented by A. M. Feldman on an ex-
periment with ozone as an adjunct to artificial ventilation
at Mt. Sinai Hospital, New York City, the author recited
details of experiments and observations upon which he un-
hesitatingly recommended the use of ozone as an efficient
deodorant, which he believed was beneficial in general im-
provement of air conditions when properly used, and harm-
less in physiological effects.
The observations of the author precipitated some discus-
sion of the old question of whether the action of ozone was
a destruction of baneful conditions or a mere masking of
odors. Dr. M. \V. Franklin ably described experiments made
by him which demonstrated by comparatively simple chem-
ical processes and analyses that compounds consisting of
most disagreeable and deleterious exhalation are so broken
up by ozone as to be destroyed and not merely compensated.
A well illustrated paper was presented by D. I'. Kimball,
author of Part I, and George T. Palmer, chief of investigating
staff, author of Part II, on "Results of Physiological and
Psychological Observations during the First Year's Experi-
ments" by members of the New York State Commission on
Ventilation. The investigation was made possible through
the generosity of Mrs. Elizabeth Milbank Anderson, who
gave to the Association for Improving the Conditions of the
Poor of New York the sum of $550,000 for various phases
of social investigation, $50,000 of which is to be expended in
an investigation of the problems of ventilation.
This commission, consisting of Professors C. E A. 'Wins-
low, F. S. Lee, E. L. Thorndike. E. B. Phelps, Dr. James A.
Miller and D. D. Kimball, was organized early in the summer
of 1913, and steps were immediately taken to provide a lab-
oratory equipment for the conduct of the studies and the
experiments. The experimental plant was installed in rooms
of the biological laboratories of the College of the City of
New York. It was aimed to provide atmospheric conditions
with temperatures from that existing out of doors or less
up to 100 deg. F. in zero weather, with humidities varying
from the saturation point to practically nothing. The illus-
trations and descriptions of the apparatus and methods em-
ployed for creating the desired conditions, selection of sub-
jects, tests and data are all of highest scientific interest to
physiologists, employers, heating and ventilating engineers,
and the public generally, in determining the influences of
different air conditions and advantages of controlled systems
of ventilation.
In the first experiment, the efficiency in mental work of
four subjects, young men about IS years of age, students of
the College of the City of New York, was compared in five
different atmospheric environments, viz.: 6S deg. F. and 50
per cent, relative humidity with ample air supply (about
45 cu.ft. per min. per person); and the same temperature and
humidity, no air supply (i.e., a stagnant condition); 86 deg.
F. and SO per cent, relative humidity with ample air supply,
and also with no air supply; and 86 deg. F., SO per cent,
humidity, no air supply (a stagnant condition but with small
electric fans blowing air on the faces of the subjects).
The experiments were thus planned to give information on
the subjects' efficiency in (1) a hot moist room as compared
with a cool room, (2) a room with ample supply of fresh out-
door air as compared with a room in which no air at all was
supplied, and (3) a hot moist room where relief was afforded
by the moving air from electric fans. The relative effects
were determined by (1) measurement of mental accomplish-
ments, (2) measurement of physiological responses and (3)
recording the opinion of the subject as to state of comfort.
In addition to the above six, other sets of tests were con-
ducted, with conditions varied to correspond with extreme
conditions of outdoor and indoor atmosphere during the
warmest season of the year.
The results of each series of experiments bring out
strongly the fact that temperature, and not chemical com-
position of the air, exerts the greater influence on the physi-
ological responses and that no distinct differences exist be-
tween fresh and stagnant air, as far as pulse and blood pres-
sure are concerned; that more food is eaten at the lower tem-
peratures, and the increased consumption on the days with
air supply is even more striking; that when the subjects
were urged in their work, about one-third more was done at
6S deg. than at SO deg. F. ; that no falling off of judgment was
indicated by exposure to the hot conditions, the slightly bet-
ter scot, i vi ii favoring the warm days and the days with air
supply; that room temperature fails to influence mi
efficiency, although the feelings of the subject differ mate-
rially, favoring the lower temperature. The results also
showed that while high temperature and even 75 deg. meas-
urably affected certain physiological reactions of the body,
mental processes were not impaired. In fact, with the same
relative humidity (1) the 75-deg. condition is somewhat pref-
i rable for tasks involving deep concentration, such as mental
i ultiplication; (2) the 6S-deg. condition is slightly more de-
sirable for combined mental and motor tasks such as type-
writing: (3) that the difference between the two temperatures
is practically negligible for maximum effort tests involving
mental processes similar to those used in additions of columns
of figures, and that there is no choice between these two va-
riables so far as the physical comfort of the subject is con-
cerned.
Application of the inclination-to-do-work test to physical
studies was instituted to analyze the effects of the 68-deg.
and 75-deg. temperatures and the importance of air supply.
These tests consisted of (a) accomplishment of voluntary
physical work, (b) variations in appetite, (c) effect of ex-
treme exertion on rate of pulse recovery, and (d) effect on
various physiological responses. The results of the work tests
show that when left free to occupy their time either at work
or rest, the subjects performed 15 per cent, more work at
6S deg. than at So deg., and that 2 per cent, more work was
done when air was supplied.
In their summary of results the authors state that it is
difficult at this time to arrive at any sweeping conclusions as
to the importance of different ventilation factors. The in-
fluences of humidity have not been studied at all to date.
The first year's work of the commission has, however, devel-
oped these facts:
1. Temperature within the range from S6 deg. to 6S deg.
F. has a marked effect on certain physiological responses.
2. Stagnant air, lacking a definite disagreeable odor but
containing all the products of the exhaled breath, including
carbon dioxide in excess of 30 parts per 10,000, is objection-
able in a manner as yet unknown but demonstrated by a
lessened desire for food, but otherwise shows no debilitating
effect on the mental process nor on the various physiological
reactions which have been studied in these experiments.
ELECTION OF OFFICERS
Officers for the year 1915, as reported by the nominating
committee, were elected as follows: President, Dwight D.
Kimball, New York; first vice-president, Harry M. Hart, Chi-
cago; second vice-president. Frank T. Chapman, New York;
treasurer. Homer Addams, New York. Managers — Frank
Irving Cooper, Boston; Dr. E. Vernon Hill, Chicago; W. M.
Kingsbury, Cleveland; Samuel R. Lewis. Chicago; Frank G.
McCann, New York; J. T. J. Mellon, Philadelphia; Henry C.
Meyer, Jr., New York; Arthur K. Ohmes, New York.
The first paper considered at the evening session of Jan.
20 had for its subject "The Centrifugal Fan," by Frank L.
Busey, and had been prepared for presentation before the
Society just previous to the death of its author. The paper
was read by ~W. H. Carrier, who stated that a very consider-
able portion of the data consisted of results of the author's
personal investigations. (Most of the leading features of the
paper are given by the author in an article by him, which
was published in the Aug. 11, 1914, issue of "Power," pp. 200-
204.) Several members spoke in the highest terms eulogistic
of the author's attainments and the work which he did as a
valuable member of the Society. The paper was ordered to
be printed in the "Transactions," and by a rising vote of all
present the thanks of the Society were tendered to Mrs. Busey
for her act of providing the Society with the manuscript.
A paper on "Engine Condensation," by Perry West, elicited
a spirited discussion, in which several members took issue
with the author's deductions leading to the statement:
It will be seen from the foregoing that in passing high-
pressure steam from a boiler through a system of piping and
thence through a reciprocating engine, a considerable heat
loss is encountered, which usually results in a considerable
percentage of condensation in the exhaust. I should say that
with simple engines this would run between 15 per cent, and
20 per cent. This means, of course, that there is never as
much steam available for the heating system as is started
with at the boiler, but just this amount of condensation. Be-
sides this, the steam is in a very moist condition, due to the
presence of this water.
David Moffat Myers, the author of the succeeding paper,
presented by discussion and in his paper, "The Heating Value
of Exhaust Steam," statements and conclusions which were
considerably at variance with the deductions of Mr. Wist.
claiming that the latter's method of estimating heat remain-
ing in the exhaust of an engine were unwieldy, and when
estimates are based on data which have been established for
I 78
pow e i;
Vol. 41. No.
hernial efficiencies of engines, the average of Mr. West's
estimates for the heat loss of simple engines would be found
about 8 per cent, too high.
"A Study of Heating and Ventilating Conditions of a Large
Building" was the subject of a paper presented jointly
by < '. E. A. Winslow and i ;. P. Maglott, in which the author.;
call attention to the facts that the progress of the art of
heating and ventilation has been seriously retarded by the
gap which, unfortunately, often exists between design and
operation. Excellently planned systems may fail on account
of changes in conditions of occupation or carelessness in up-
keep and management; while on the other hand, operation
sometimes reveals shortcomings in design which should be
instructive in the planning of future installations. Careful
studies of actual results obtained are none too common. The
authors present such a study of a large business office build-
ing in New York City, heated in the main by direct steam
radiation, with certain rooms on the lower floors in part in-
directly heated by plenum air supply.
A scientific investigation showed, as all too often is the
case, that both the heating and the ventilating systems had
been allowed to fall into such disrepair and to become so ill
ENTERTAINMENT
The entertainment committee provided a program for out-
of-town members and guests, which included social sessions.
shopping tours for the ladies, theater parties and visits to
points of interest. The annual dinner, which was held at the
Hotel McAlpin on the evening of Thursday, Jan. 21, was at-
tended by nearly 200 members and guests and proved to be
one of the most enjoyable events in the history of the Society.
MsiftaOEasil Msupiinx© ECinijaiEaeeif'g''
The National Marine Engineers' Beneficial Association of
the United States of America convened in its fortieth annual
session on Monday, Jan. IS, at 10 a.m., at the Raleigh Hotel,
"Washington, D. C. The following officers occupied their re-
spective chairs: William F. Yates, president; George H. Bowen,
second vice-president; Charles N. Vosburgh, third vice-presi-
dent; George A. Grubb, secretary; Albert L. Jones, treasurer.
The several daily sessions of the delegates were from 9:30
The Mabine Engineers' Beneficial Association's Foktieth Convention
Group outside the White House after being received by the President — The new National Officers — The Smoker
adjusted to present needs as to fall far short of realizing the
purposes for which they were designed. It is just such con-
ditions as these which constantly bring discredit upon the
art of heating and ventilation, and they are conditions which
can only be brought to light by comprehensive engineering
and sanitary study of actual operation.
Other papers presented and discussed were: "Studies in
Air Cleanliness," by G. C. and M. C. Whipple; "Problem of
City Dust," by R. P. Bolton; "Cinder Removal from the Flue
Gases of Power Plants," by C. B. Grady; "Recirculation of
Air in a Minneapolis School Room," by Frederic Bass; "Com-
parative Tests of Various Types of Exhaust Ventilators for
Sleeping Cars," by Dr. T. R. Crowder: "Ventilation of Indus-
trial Plants," by T. Graham-Rogers, M. D. ; "Test of a Cast-
iron Sectional Down-Draft Boiler," by C. A. Fuller: "Crude
oil Fuel." by H. S. Haley; "Some Phases of Room Heating by
Means of Gas Burning Appliances," by George S. Barrows;
"Rational Methods Applied to the Design of Warm Air
Heating Systems," by Roy E. Lynd; "Tests on Threading
Steel and Wrought-lron Pipe," by C. G. Dunnells; "Capaci-
ties of Steam Pipes at Different Pressures," by James S.
Otis.
a.m. to 1:30 p.m. There were present 60 delegates, repre-
senting 115 votes from all of the large lake and river cities of
the United States. The financial report showed the organ-
ization to be in a prosperous condition. Many matters of
special interest to the association were discussed and dis-
posed of with harmony and dispatch.
On Thursday morning an adjournment was taken by the
delegates to permit of the convention visiting the White
House to be presented to President Woodrow Wilson. There
was a theater party on Monday evening to Keith's Vaudeville
House for everybody, and on Wednesday evening there was
one exclusively for the ladies. The smoker on Thursday night
tendered to the engineers by the Supplymen was the big event
of the convention, and was heartily enjoyed by all. Fully
400 delegates and invited guests assembled in the ballroom of
the Raleigh, where the "New York Bunch" of entertainers
made things lively, and kept the audience in good humor for
the entire evening. Good things to smoke and drink were
served plentifully.
At the session on Wednesday morning the following na-
tional officers were elected: A. Bruce Gibson, president, San
Francisco, Calif.; E. M. Roberts, first vice-president, New York
City; C. N Vosburgh, second vice-president. New Orleans, La.:
February
p o w e i;
179
William C. Wilson, third vice-president, Philadelphia, Penn
George A. Grubb, secretary, Chicago, 111.; Albert L. Jones,
treasurer, Detroit, Mich.
The advisory board includes: Thomas L. Delahunty, New
York City; George H. Willey, Boston, Mass., and Robert L.
Goelet, Norfolk, Va.
The trustees of the "American Marine Engineering" com-
prise Clinton E. Thurston, Norfolk, Va.; Joseph G. Myers,
Charleston, S. C, and William Murray, New York City.
The forty-first annual convention will meet at Washing-
ton, D C, the week beginning Jan. 17, 1916.
©o ELsxIhfilbaft
boiler makers as to the proper rate of evaporation to use aa
the foundation for a catalog rating. It is not at all uncom-
mon for the condition outlined above to come about, resulting
in the purchase of a boiler 20 per cent, smaller than either
the buyw or his engineer desired. — "The Locomotive."
j£xqp<n>saftii<o>ini
The exhibit of the General Electric Co. in the Transporta-
tion Building at the Panama-Pacific International Exposition
will comprise electric locomotives for various classes of ser-
vice, including steam-railroad electrification, railway motors
and all kinds of apparatus and accessories for electric rail-
ways, signal accessory electric devices, electric apparatus and
equipment for railway shops, electric illumination for cars and
shops, etc.
One of the electric locomotives is one of four recently built
for the Butte, Anaconda & Pacific R.R. and is a duplicate of
the original 17 units put into service in 1913. These are the
first 2400-volt, direct-current electric locomotives ever built.
Each unit weighs SO tons, and two are coupled together for
freight service hauling trains of 4600 tons at 16 miles per
hour up a 0.3 per cent, grade, and at 21 miles per hour on
level track. Two passenger locomotives, operating as single
units on this system, are geared for a max'mum speed of 45
miles per hour on level track.
)<D>WIni
)©ail©s°
We are rapidly drawing away from the horsepower method
of rating boilers. This has come about through the working
of two different tendencies, both of which diminish the value
of such a statement of boiler capacity. In the first place,
there no longer exists any particular equality between the
horsepower of a boiler and the amount of engine power which
it may be expected to serve, although at the time of the
adoption of the present unit, in 1S76, it was given a value
about equal to the average steam consumption per horse-
power of the engines exhibited at the Centennial Exposition,
on the assumption that this would approximate average con-
ditions at that time. Modern engines have so far improved
in economy that it is now possible for one boiler horsepower
to serve from two to three engine horsepower of connected
load under favorable circumstances. There is, moreover, an-
other influence at work to lessen the value of the horsepower
rating — namely, the growing demand for greater and greater
boiler output per unit of heating surface — so that it Is no
longer a matter of special novelty to read test returns of
boilers in regular operation at upward of 200 per cent, of
what a few years ago would have been considered a proper
performance.
The result of these two changes in power-plant economics
is to make it more and more necessary to plan boiler plants
on a heating surface and not a horsepower basis. The de-
signing engineer first determines the rate at which he expects
to be able to work his heating surface, with the character
of coal, draft, setting, etc., which he expects to utilize; that
is, he sets a figure for the amount of water which he may
expect to evaporate on each square foot of heating surface
in the particular plant he has in mind. It is then only neces-
sary to add the combined water rates of the different steam-
consuming devices and divide by the evaporative rate to
arrive at the total heating surface, "which he can divide among
the proper number of boilers.
When an essentially nontechnical buyer of boilers is ob-
taining competitive bids from boiler makers, he is apt to
think and talk in terms of dollars per 100 or 150 (or some
other dumber) horsepower. He naturally assumes that this
is a proper basis upon which comparisons may be made. He
will of course be disappointed if, having purchased the boiler
from the lowest bidder, he finds to his surprise that this
builder has bid on a boiler rated at 10 sq.ft. to the horse-
power, while perhaps his engineer in deciding on the neces-
sary size has calculated on 12 sq.ft. to the horsepower rating.
This is very confusing to the owner who is not an engineer
or who is not familiar with the diversity which exists among
^sa^a!ae©ff>airag iff ouairac
The ceremonies inaugurating the Engineering Foundation
were held Wednesday, Jan. 27, at 8:30 p.m., in the auditorium
of the Engineering Societies Building in New York City. The
name, The Engineering Foundation, has been given to a fund
"to be devoted to the advancement of the engineering arts
and sciences in all their branches, to the greatest good of the
engineering profession and to the benefit of mankind." The
administration of this fund will be intrusted to the Engineer-
ing Foundation Board elected by the trustees of the United
Engineering Society, the holding corporation of the Engineer-
ing Societies Building, and composed of eleven members, two
each from the American Society of Civil Engineers, the Amer-
ican Society of Mechanical Engineers, the American Institute
of Mining Engineers and the American Institute of Electrical
Engineers, two members chosen at large, and the president of
the United Engineering Society, ex-officio.
Gano Dunn, president of the United Engineering Society
and past-president of the American Institute of Electrical
Ambrose Swasey
Engineers, presided, and announced for the first time the
name of the donor of the initial gift of $200,000 — Ambrose
Swasey, who is widely known as a member of the firm of
Warner & Swasey, of Cleveland, Ohio, prominent machine-
tool builders and the foremost builders of telescopes in the
world. Among the instruments which they have designed are
the famous Lick, Yerkes and United States Naval Observatory
telescopes, as well as the 72-in. reflecting telescope for the
Canadian Government, which is now under construction. In
addition to his engineering achievements, Mr. Swasey is
known for his practical efforts toward scientific education
and the advancement of the profession. His gift for the es-
tablishment of The Engineering Foundation is in line with
these undertakings, which may be destined to outlast his fame
as an engineer.
In response to the ovation given Mr. Swasey at this time,
he arose and made an acknowledgment of his appreciation
of the spirit in which the announcement had been received.
Other speakers of the evening were: Dr. Henry S. Pritchett,
president of the Foundation for the Advancement of Teach-
180
PO w e i;
Vol. 41. No. 5
ing; Dr. Robert W. Hunt, past-president of the American In-
stitute of llining Enginei i Donald, past-pres-
ident of the American Society of Civil Engineers; and Dr.
Alexander C. Humphreys, past-president of the American So-
ciety of Mechanical Engineers.
Following the ceremony a reception to Mr. Swasey was
held at the platform of the auditorium. A testimonial dinner
to him was given on the preceding evening by the president
and board of trustees of the United Engineering Society, at
which speeches were made by leading engineers representin-
the civil, mining, mechanical and electrical branches of the
profession, which helped to further cement the close relation-
ship existing and gave promise of hearty cooperation in the
future on all matters affecting the profession in general.
sE&§£<=MaM Eiagpiinie WVeelkedl
Early in January the compound condensing engine driv-
ing a train of hot rolls at one of the plants of the American
Sheet and Tin Plate Co., at Chester, W. Va. (near East Liver-
pool, Ohio), was badly wrecked, caused by the breaking of
the strap on the crosshead end of the connecting-rod.
When freed from the rod the crosshead and low-pressure
piston were driven through the low-pressure cylinder, break-
ing it beyond repair, also the distance piece between the high-
and low-pressure cylinders. The high-pressure cylinder was
not so severely damaged, because the studs which held it
to the bedplate gave way and allowed the cylinder to recede.
It was torn from the bedplate and its steam connections at
the throttle and receiver pipe.
The engine was built by C. & G. Cooper and had been in
use about 14 years. It was 26&54x60-in. and ran at 65
r.p.m., carrying a 22-ft. flywheel weighing about 60 tons,
and was geared to a shaft driving six hot mills. A steam
pressure of 110 lb. was carried, exhausting into a Worth-
ington condenser.
Fortunately, no one was injured, but the mill will be shut
down for fully four weeks, during which time about 500 men
will be idle. Our representative was, unfortunately, unable to
procure photographs, as the work of clearing away the wreck-
age and reconstructing the engine was begun at once and all
haste was made to get the mill in operation again.
F. W. Rose, of the firm of Rose & Harris, engineers. Audi-
torium Building, Minneapolis, has been elected secretary and
treasurer of the Minnesota section of the American Society of
Mechanical Engineers.
Errett L. Callahan, for the past six years manager of the
new business department of H. M. Byllesby & Co., Chicago,
111., has resigned that position lo become Chicago district
manager for the Westinghouse Lamp Co.
David A. Wright, for several years with the Tale & Towne
Manufacturing Co.. of New York, as district manager in the
West, has engaged in business for himself as manufacturers'
agent, at 149 South Dearborn St., Chicago, 111. He is specializ-
ing on labor-saving and pneumatic machinery, cranes, hoists
and trolley systems.
E. P. Roberts, commissioner of smoke abatement, Cleve-
land, Ohio, has tendered his resignation, to take effect Feb. 1,
and ■will resume business as a consulting engineer, with
temporary address 2053 East Ninety-sixth St., Cleveland. In
addition to general power-plant engineering as heretofore, he
will make a specialty of smoke abatement.
Dr. Edward Weston, of Xewark, X. J., has been presented
with the ninth impression of the Perkin medal, given for dis-
tinguished service in chemistry and electrochemistry. The
ceremony took place on Jan. 22, at the Chemists' Club, Dr. G.
W Thompson presiding. The medal was presented by Doctor
Chandler, senior past-president of the Society of Chemical
Industry, after briefly reviewing the career of the recipient.
EMGIMEERIMG AFFAEIRS
The Western Soeiety of Engineers, Chicago, has elected
the following officers for the year 1915: President, W. B.
Jackson: first vice-president. Ernest McCullough; second-vice
president. Charles B. Bui dick: third vice-president. P. B.
Woodworth; treasurer, C. R. Dart: trustees, F. E. Davidson
(one year). H. S. Baker (two years). O. P. Chamberlain (3
years i-
Rallroad Nigrht for Chicago Section V. s. M. I-:. — Jan. S "was
railroad night for the Chicago section of the American So-
ciety of Mechanical Engineers. As usual, it was a dinner
meeting held in the Louis XVI room of the Hotel La Salle.
There was a large attendance and a number of able speakers.
S. G. Xeiler presided. The subjects discussed were: The Lo-
comotive Superheater, Locomotive Stokers, and Railway Econ-
omics. The subject first named was introduced by R. M. Oster-
mann, of the Locomotive Superheater Co. C. F. Street, presi-
dent of the Locomotive Stoker Co., gave some statistics on
the co i i n, when using stokers and outlined the ad-
vance that had been made in this field. Railway Economics
was discussed at length by W. A. Smith, president of the
"Railway Review."
Technology Clubs Convention — The Technology Clubs As-
sociated, an organization of former students of the Massa-
chusetts Institute of Technology, will hold a reunion in Pitts-
burgh Feb. 19 and 20, at the invitation of the Pittsburgh As-
sociation. The main features will be: Class luncheons the
fust day; course luncheons the second day where discussion of
the various curriculums will be undertaken and where gradu-
ates, in the light of their later experiences, will be invited to
criticize their own courses of instruction; and the banquet
Saturday evening, when addresses will be given by President
Richard C. Maclaurin and probably President A. Lawrence
Lowell, and two other speakers of international prominence
whose names are to be announced later. All alumni and
former students of the institute are invited.
International Engineering Congress — The American Society
of Mechanical Engineers has issued a circular letter to its
membership, urging individuals to subscribe to the Interna-
tional Engineering Congress to be held in San Francisco in
connection with the Panama-Pacific International Exposition,
Sept. 20 to 2", 1915. As one of the five national societies in
the hands of the representatives of each of which the Congress
is placed, it is urged by the mechanical engineering society
that its members should feel responsibility and give their
fullest support to the Congress. The fee for membersnip
is .?", which entitles a member to the index volume which
covers general proceedings, indexes and digests, and any one
of nine other volumes which are published or to be published,
as follows: Vol. 1, The Panama Canal: Vol. 2, Waterways and
Irrigation; Vol. 3, Railways: Vol. 4, Municipal Engineering;
Vol. 5, Materials of Engineering Construction; Vols. 6 and 7,
Mechanical and Electiical Engineering; Vol. >, Mining Engi-
neering and Metallurgy; Vol. 9, Xaval Architecture and Marine
Engineering; Vol. 10, Miscellaneous.
Skinner Engine Co.. Erie, Penn. Catalog. Universal Una-
flow engine. Illustrated, 2S pp., $%xll in.
The Emerson Electric Mfg. Co.. St. Louis, Mo. Catalog
Xo. 6700. Electric fans. Illustrated, 4S pp., 7x10 in.
Kennedy Valve Mfg. Co., Elmira, X. T. Catalog. Gate,
globe, angie, radiator and corner valves. Illustrated, 124 pp..
6x9 in.
B. F. Sturtevant Co.. Hyde Park, Mass. General Catalog
Xo. 195. Fans, exhausters, blowers, engines, steam turbines,
etc. Illustrated, 116 pp., 6%x9 in.
Armstrong Cork & Insulation Co., Pittsburgh, Penn. Book-
let. "Permanent Fortifications." Nonpareil corkboard in-
sulation. Illustrated, S pp., 3%x6 in.
COHTIRACTS TO BE ILET
TREASURY DEPARTMENT, Supervising Architect's Office,
Washington, D. O. January 5. 1915 — Plans and specifications
are now approaching completion for a central heating, light-
ing and power plant, to be erected in this city under the
direction of this office. These plans and specifications will
be ready for delivery on or after January 15. Bids may be
submitted for the entire work or for any one of the following
sections: Power plant building complete, with steel stacks:
boilers; generating apparatus; pumping equipment; con-
densers; coal and ash handling apparatus; steam and water
piping; switching gear; tunnels; substation apparatus, etc.
Prospective bidders should immediately submit to this office
applications for plans and specifications, stating the portions
of the work upon which they desire to bid. If it appears
that the applicant is in a position to bid on all of the work
in any one of the sections of the project, or upon the entire
work, the plans and specifications will be forwarded. No
plans or specifications will be furnished sub-bidders or others
not in a position to submit a bid on all of the work comprised
in at least one section. The Department will be able to allow
only about 15 days for the preparation of estimates. At the
time plans and specifications are forwarded to bidders the
date for the opening of bids will be stated, and this date
will not be extended. O. WEXDEROTH, Supervising Archi-
tect.
Vol. II
POWER
NEW VOI.'K. FEBRUARY '.), 1915
No. 6
Chats
Too M^uiclhi Coal
T,
I®2°® ns @.ira ^sn&Msairag ^<st psv&Ihettl© mt&'S'w wlhaclhi y&msM sypptrecmfi®
■ ©IF si. snstmaEsijp case
the winter was just as cold as previous ones, ii' not colder.
Pie glanced at the calendar to make sure it. was Feb. 1
instead of A.pr. 1, and finally walked to the window In
see that string of cars. Yes, the coal was there ! Ah !
he had il ; the coal was not being used !
The engineer suggested that they compare the weekly
coal consumption reports. Yes, the manager was right :
the coal was not being used as formerly. Tbe reports
showed that up to date about one hundred tons less coal
bad been used these lasl winter months than for the cor-
responding months of previous years.
.HE plant is the ordinary large, industrial kind
where much low-pressure steam is used for manufactur
ing purposes. The management — the president and the
usual outfit — is representative of the average.
The new chief engineer was engaged on a salary and
percentage-of-saving basis. Of course, the first thing he
did was to return to the boiler the many pounds of 210
deg. F. condensate allowed to merrily flow to the sump
and sewer. Winter was coming on, and one need not be
a college professor to know that changes in pipe sizes
and arrangements and tbe installation of a few traps on
the heating system would make the coal man feel badly.
Tbe volume of business was fairly constant, and had
been for years, so the coal was bought by contrail and
supplied in unvarying amounts as regularly as you get
sleepy between 2 and .'! a.m. when you are on the 12-to-S
watch. The coal was stored m a large low building and
bad to be trimmed considerably to Mil it. Soon the ell'ccl
of the changes in the uses of steam and the disposition
of condensate was made apparent by the full coal cars
on the siiling and the labor necessary to trim coal in the
storage bin. The amount of coal on band was becoming
a veritable nuisance !
Tbe chief asked the manager to have the supply
stopped for a while. This was a new one on the man-
ager; the engineer's complaint had always been the other
way, and the manager did not understand. Couldn't
I be engineer find room for it somewhere? The quantity
received was as usual, and he could prove it by compar-
ing the monthly statements. The mills ran full time;
What does this case show? Here is an actual, honest-
to-goodness example of tbe amount of worth-while atten-
tion some concerns pay to the power plant.
And the engineer was engaged on a percentage-of-
saving basis, too!
It shows that tbe engineer must, keep duplicate reports
ami. above all. sec to it that the management really
studies them and is given every opportunity to know
what their proper interpretation means in its relation to
the chief engineer and tbe cost of manufacture.
This engineer had applied himself to the task of re-
ducing costs and improving service, had slaved up late
nights outlining necessary alterations to this end — he
was making good! And he was getting no more moral
credit than the man who would have used the 100 toDS
and saved disturbing the manager. Things would have
gone this way until the books were examined to deter-
mine how much in percentage-of-saving was due the
engineer.
182
POWER
Vol. 41 , No. 6
le M^aimicijml Og'Ihittiinig' Pfemt
By \V. L. KlDSTON
SYNOPSIS — This plant will assist in carrying
the winter peak loads of the Cedar Falls (Wash.)
hydro-electric plant. A steam pressure of 200 lb.
is carried on tin ,'lirr, boilers, with 125-deg. super-
heat. The turbo-generator is of 7500-lew. capacity.
The boiler furnace- are designed for burning fuel
nil ,,,■ coal with mechanical si,,!,, is. which ran eas-
ily be /ml in, place.
The new steam-generating station oi' the Seattle
(Wash.) municipal system, known as the Lake Union
auxiliary, has a continuous capacity of 9375 kw. and will
lie used by the lighting department to help the main hy-
'.?»>-
Fig. 1. New Seattle Generating Station
dro-electric station at Cedar Falls over the heavy winter
peaks and to take its full capacity load in ease of accident
to the water-power station or transmission lines. The
steam plant is near the geographic center of the city, on
the east shore of Lake Union It will be accessible from
Puget Sound and Lake Washington through the Lake
Washington canal, and by land it can be reached by the
Lake Union belt-line railway and by the tracks of the local
traction company.
The building (Fig. 1), built of reinforced concrete, is
90x100 ft. and 5? ft. from the basement floor to the cor-
nice and was begun on Apr. 25 of last year. It was de-
signed and built by the Department of Buildings of the
city of Seattle. The foundation is on piles. The base-
ment floor is IS ft. below the level of East Lake Ave., and
a concrete retaining wall containing 800 cu.yd. was built
to support the street and protect the structure from pos-
sible slides from the hill beyond. Steel sash is used
throughout the building, and as the space between col-
Three Water-Tube Boileks with 8230-
Sq.Ft. Heatixg Surface
minis is glazed, ample light is secured. A 25-ton crane
with a 30-ft. span serves the turbine room.
The plant contains three water-tube boilers (Fig. 2).
each baving 8230 sq.ft. of heating surface, which will
supply steam at 200 lb. pressure and 125 deg. superheat
to the 7500-kw. turbo-generator set (Fig. 3). The boil-
ers are on the street floor at the west side of the building,
with the tiring aisle next to the lake. They are equipped
Fig. 3. The T500-K\y. Turbo-Generatob Unit
for burning oil, but the settings are arranged for stokers
and ash hoppers, so that a change may be made to coal
burning at any time by inserting the stokers, the tracks
for which are in place. The basement under the boilers
is planned to accommodate the ash-handling cars. Pro-
vision is made for a fourth boiler. The boilers are guar-
February '.), 1915
POWEE
183
anteed for ',', per cent, efficiency at full load and to oper
ate satisfactorily at 180 per cent, continuous overload.
Two steel stacks. 90 in. diameter, designed for coal burn-
ing, extend 170 ft. above the boiler-room floor, each to
care for two boilers.
Two steel oil-storage tanks, 11 ft. and 20 ft. long, ol
7 Qafe Valve
Pig. 4. Elevation of the Boiler Boom and Basement
Ham feed
water header
\ - the tanks arc adjacent to the building, ii was
n. i r--,ir in bury them, and a concrete wall was built,
arating and inclosing them. The space around the tanks
was then filled with earth to a depth of I ft. above the top
of the shells. Six-inch connections to the domes are used
Eor filling the tanks and connections of the same size on
the under side join with an 8-in. suc-
tion header, to which the two motor-
< 1 i-i \ . pumps, each with a ca-
pacity of 16,000 gal. per hour, are con-
nected. This header runs out to tin-
lake for use in unloading oil-tank cars
or oil -cows.
One 7200-gal. sen ice tank, i ft. in
diameter by 2 1 ft. long, is placed above
the storage tanks, and the suction pipes
from the two burner pumps run through
the dome and down to the bottom of the
tank, terminating in a foot valve. The
tank is separated into halves bj a parti-
tion, thus forming two tanks, both of
which have a 30-in. dome with a screw
over. A steel ladder runs to the bottom
of the tank. The 6-in. connections in the
domes are used for Idling the tanks and
the I '--in. suction pipes for empty-
ing them. A 2y»-in. overflow pipe runs
from each oil heater back to the ser-
vice tank. A 6-in. pipe from the fill-
ing pipes to the street makes it possi-
ble to fill any of the three tanks from
oil trucks. Tumps to supply the oil
burners are on the boiler-room floor, as
are the oil heaters.
The boilers connect to a 12-in. head-
er (Fig. 1). from which steam is tak-
en to the turbine (Fig. ]). The gen-
erating unit is a horizontal turbine connected by a flexible
coupling to a 2500-volt, two-phase alternator, at 1800
15,000 gal. capacity each, arc buried just outside the
boiler room on the south side of the building. Both tanks
have domes 1 ft. in diameter and 1 ft. high, with screw
covers and steel ladders to permit of inspection. This ca-
pacity per tank is the largest allowed by the city ordi-
Pig. <;. Tuebine-Driven House Pump
r.p.m., and rated at ^.300 kw. at 80 pier cent, power factor
with 50-deg. Centigrade rise above the room temperature,
and at 93T5 kw. at 80 per cent, power factor with 65-deg.
184
P 0 W E li
Vol. 41, No. 6
rise! The temperature in the generator coils is measured
by a resistance thermometer inserted between them, and
is registered on the switchboard. The unit is guaranteed
to produce one kilowatt-hour from 12.95 lb. of steam at
L90 lb. pressure and 125 deg. superheat when operat-
ing at full load.
The condenser, of the rectangular-jet type, and placed
under the turbine ( Figs. 4 and 5), will maintain 28% in.
nt vacuum when condensing 97,500 lb. of steam per hour.
The centrifugal circulating pump is mounted on the
shaft with the rotary air pump and both are driven by a
small impulse turbine. The boiler-feed pumps and the
service pump ( Figs. 6 and 9) are also of the centrifugal
type with four stages, and are turbine driven. Steam
for these auxiliaries is taken from a 6-in. saturated-steam
header, and the exhaust is used in the 2500-hp. meter-
ing feed-water heater. The exciter, rated at 50 kw., 125
Fig. 7. Oil Seatebs and Pumps
3 3
BASEMENT PLAN
SECTIONAL ELEVATION
I'm. 8. Plan and Elevation' of Tukbine-Room Basement
February 9, 191J
pow e n
185
volts, is also turbine driven. Fig. 8 shows the piping
arrangement.
As the steam-plant site is on the shore of Lake Union, a
fresh-water lake, there is an abundant supply of cooling
water for the condenser. The water supply is brought to
the plant from an intake 120 ft. out in the lake, through
a 30-in. cast-iron pipe to a concrete screen box at the west
side of the building, and from there through a second
run of pipe to a cold well at the end of the condenser. xVn
lS-in. pipe supplies the condenser with cooling water,
which is drawn into the condenser l>\ vacuum. In start-
ing, a jet of «ater from the city mains is used to condense
Fig. 9.
One of the Two Turbine-Driven Centrif-
dgal boiler-feed pumps
the steam and create a vacuum in the condenser shell.
The 18-in. discharge pipe from the condenser connects
with the hotwell, which is a concrete tunnel 4 ft. wide by
10 ft. deej). In case of a future installation, this tunnel
will connect the two units. A 30-in. cast-iron pipe serve
as an outlet for the hotwell and discharges the hot water
into the lake at the hack wall id' the building.
The turbine set is on the street floor, on the east side.
next to East Lake Ave., and the switchboard is in the same
room. Current is stepper] up to 15,000 volts, two-phase,
for distribution over the city, ami the steam station will
be connected to the main distributing station at Seventh
Ave. and Yesler Way by a direct 15,000-volt tie line.
The step-up transformers, of the same capacity as the
turbine, are in the basement under the turbine room,
where the oil switches and 2500-volt and 15,000-volt wir-
ing are placed. Provision is also made to use the steam
station for distributing, for which purpose the oil
switches, feeder regulators and street-lighting transform-
ers will go in the basement.
The steam plant is on the same lot with a 1500-kw.
water-power auxiliary, which uses the overflow from the
Volunteer Turk reservoir of the city water system, situ-
ated on the hill U5 ft. higher than the lake. Both plants
will he operated from the same switchboard and will
work together to safeguard the service of the system.
The main generating station at Cedar Falls is being ex-
tended and improved by the erection of a $1, 100,000 dam,
which will permit of a development of 10,000 kw. J. D.
Ross, superintendent of lighting, is in charge of the
Seattle municipal plant.
Fnirs<l=Andl Jsis° £©2= P©w©s° Plsxiniils
Accidents frequently happen in and about a power
plant, and in many cases the injured could be attended
by the laymen if first-aid materials were at hand. A
first-aid jar has been prepared to meet such require-
ments by the Conference Board of Safety and Sanitation,
of which Magnus W. Alexander. General Electric Co.,
West Lynn, .Mass., is secretary.
The jar is structurally strong anil a special annealing
treatment makes the glass still stronger. It i.- made
with smooth surfaces and with straight walls on the in-
side to promote cleanliness and facilitate the removal of
first-aid materials. A convenient carrying handle is
molded to the glass cover, held by suitable spring clips
which are a part of a metal cage holding the jar; this
( age affords added protection against breakage. A rub-
ber gasket between the jar and the cover makes the out-
fit dustproof.
The jar is made only high enough to accommodate the
bottles of medicaments stored in it so that the stoppers
Fibst-Aid Jab
cannot come out when the cover rests on the jar. Medi-
cine bottles, bandages, absorbent cotton, burn ointment
in collapsible tubes and a wire-gauze splint are arranged
along the wall id' the jar, so that they are plainly visi-
ble from the outside and can be quickly located. A spe-
cially constructed metal dish placed inside of the jar
keeps the materials in their proper places; it is also w>r<]
as a receptacle for tourniquet, medicine glass, gauze ban-
dages, medicine droppers, spoon, scissors, etc.
The jar is aLx ut 9^ in. in diameter, G in. high, and
1S6
POWER
Vol. 41, No. 6
complete with contents weighs only slightly more than
12 lb. It, however, includes every material which a con-
ference of physicians with extensive experience in the
treatment of injuries agreed upon as necessary for effective
first-aid treatment, by laymen.
Suitable first-aid instructions are printed on the in-
side of the cover, while on the outside appears the stand-
ard list of materials which should always be kept in the
jar and brief directions for the use and care of the outfit.
This jar has been approved by the board, which is
composed of representatives of the National Founders'
Association. 29 South La Salle St., Chicago; the National
Association of Manufacturers, 30 Church St., New York
City; the National Metal Trades Association. Peoples
Gas Bldg., Chicago, and the National Electric Light As-
sociation, 29 West 39th St., New York City. The outfit
is sold at practically cost price, as there is no intention
to make a profil on any of the articles standardized by
these associations, and can be secured by writing the sec-
retary of anv of the associations mentioned.
SYNOPSIS — The writer reviews the oil-fuel sit-
uation and points out the legitimate fields fur the
different types of engines. He warns against the
defects in the low-compression, pump-injection
ti/pe when attempting to use heavy oils, ivlneh
should be used only in the high-compression en-
gine, ami champions the vaporizing type.
The manufacture of internal-combustion engines is
being influenced to a certain extent by the fuel situation,
and the consequent demand of the public for an engine
which will handle heavy grades of liquid fuels. Whether
this demand is to continue will be influenced by the avail-
ability of the heavy liquid fuels, their prices as compared
with lighter fuels, and the success of the engines which
claim to use them. Therefore, it would he well for the
buying public to consider carefully and without prejudice
all phases of this subject before it continues to bring
about what may prove an undesirable tendency in the ap-
plication of the internal-combustion engine for general
power purposes.
Oil-Fukl Situation
During the past k'w years there have been marked
changes in the oil-fuel situation, and it is practically im-
possible to prophesy what the future will develop. The
heavy drain on the gasoline supply for the automobile
trade has been the apparent cause for its rise in price.
However, this has now been reduced to practically the
figures which prevailed several years ago, but it is still
too high to be considered for use in the larger or inter-
mediate sizes of internal-combustion engines.
An important feature is the percentage of fuel of dif-
ferent grades available from crude oil. Refiners have
been able to secure in recent years a larger percentage of
gasoline from crude oil than heretofore, but the quality of
the gasoline has also been reduced. Crude oil from differ-
ent localities varies greatly in quality, but a fair average
would indicate that about 15 per cent, can be turned into
gasoline or naphtha. About 45 per cent, is kerosene, and
about 10 per cent, of a high-grade distillate above 39 deg. ;
another 10 per cent, is a low-grade distillate below 39 deg :
while about 15 per cent, is turned into lubricating oil, and
the remaining 5 per cent, is slop. It is evident, therefore,
that a small percentage of the refined product, about 10
per cent., is of such a nature as to require a crude-oil
ongine. Furthermore, about 50 per cent, of the refined
product can be handled in the conventional four-stroke-
cycle vaporizing type.
There is a large market for the heavier grades of re-
fined oil to be used for burning under boilers, oiling
streets, etc., which often makes it difficult for the small
purchaser to secure, or to continue to secure, this fuel
For power purposes. Sometimes the small purchaser finds
that it is necessary to buy his fuel in tank-car lots in order
to gain the point of economy desired. It is evident, there-
fore, that the purchaser of an engine designed for hand-
ling crude oil or an equivalent fuel is necessarily sub-
jected to the caprices of the market.
It is true that there are a number of localities, espe-
cially in the West and Southwest, where the heavy liquid
fuels are being purchased at comparatively low prices.
However, it is questionable whether this condition will
continue, inasmuch as the supply of fuel oil to burn under
boilers has frequently been taken away from manufac-
turers who have gone to the expense of installing boiler
appliances for burning this fuel. Moreover, there is wide
variation in the quality and constituents of heavy oils,
depending upon the quality of the crude, the method of
refining, tendency of the refineries in accordance with the
demands, etc.
While gasoline is also uncertain in its price, kerosene
has remained at practically the same price, has always
been available in most localities, and does not vary in
quality.
There are, undoubtedly, many cases where the Diesel
engine is the proper type to use, considering especially its
high thermal efficiency and the ease with which its fuel
can be stored, transported and handled. The following
objections can be raised against it, however. It is com-
plicated in design, necessitating strict attention to the
minutest details and requires a very high grade of work-
manship. Moreover, correct adjustment must be main-
tained at all times, and skilled attendance with corre-
sponding high cost is essential. Fuels of low quality and
low price have frequently been used when the plant was
first installed, and later a high-grade fuel has been sub-
stituted. Depreciation and maintenance have in many
cases been excessive in addition to the first cost being
high. Finally, this type of engine is extremely sensitive
to irregular or improper conditions.
In spite of these objections there are many successful
Diesel installations. If a purchaser takes these points
into consideration, arranges to keep the engine in prime
condition at all times, is assured that the proper fuel will
February <J, 1015
1' ( ) \Y E H
1!
be available at a low price, if natural gaa is not available,
and his conditions do not favor producer gas, and if his
power requirements are not less than 100 hp., he may be
justified in purchasing a Diesel engine.
Semi-Diesel Engines
Coming now to a class of engines for powers of 15 to
100 hp., the purchasers of these sizes ordinarily do not
give the engineering features due consideration. Being
without the necessary experience and knowledge them-
selves, they are largely at the mercy of the ambitious
salesman who has a tendency to exaggerate the qualifica-
tions of the article he is handling. There has been a
clamor for engines of those sizes which will burn heavy
fuels, such as have been successfully handled in the Diesel
engine. Owing to this demand, there has been a natural
response on the part of some manufacturers to produce
550
Diagram from Hot-Plate, Air-Injection
Engine at Rated Load
an engine '.Inch would fulfill these requirements.
It is evident that the high first cost of the Diesel engine
would prohibit its sale among the majority of purchasers
who desire engines of this size.
There is said to be from 400,000 to 500,000 hp. in
engines of the Diesel type used in Europe. There are also
a number of these engines in this country, but the fuel
situation in Europe is such as to necessitate the use of
an engine of this type to a far greater extent than has
been the case in this country. It has been repeatedly
reported in this country that in engine installations of
the Diesel type it has been found desirable to use a lighter
grade of fuel than was originally intended. This is brought
about by the fact that less trouble and less close attention
are required with the lighter and higher-grade fuels.
This being the case with an engine which employs extreme
methods in order to burn the fuels economically ami
satisfactorily, how can it be at all satisfactory to handle
such fuels in an engine where these methods are not
employed ?
In an attempt to reduce the cost of manufacture, and
still satisfy the demands for an engine which will run
on heavy liquid fuels, attempts have been made to depart
from the Diesel principle. The first attempt was to
change the compression from 500 to 300 lb. This re-
duction in compression means that the fuel does not burn
immediately upon entering the combustion space, as the
heat of compression is not sufficient, and in order to obtain
the desired temperature a hot plate is projected into the
cylinder.
This type retains the air system of fuel injection.
A two-stage air compressor i- used, which discharge?
at approximately (100 lb. directly through the fuel valve
and against the hot plate in the cylinder. The quantity
of fuel is measured in a manner similar to that of the
Diesel engine. This system avoids the necessity of
carrying such high injection air pressure, but there is
only a partial burning of the fuel, and in explosion
takes place, the initial pressure depending on various
conditions, such as the timing of the fuel injection, the
nature of the fuel, tin- temperature of the engine, the
temperature of the hot plate and the compression
temperature. An indicator diagram from such an
engine is shown in Fig. 1.
If an engine of this type is built as heavy as it should
be to withstand the high pressures, and if all other parts
are properly designed and constructed, the first cost
is almost as high as the Diesel.
An extreme departure from the Diesel principle is
the two-stroke-cycle engine using the hot bulb, pump
fuel injection, water injection, in the majority of cases
crank-case compression, and light construction with
a compression ranging from TO to 150 lb., and in some
case- .100 lh. In order to start this engine it is necessary
first to heat the hut bulb externally, which requires
ordinarily from 15 to 20 min. Sometimes difficulty
with the burners necessitates a much longer time.
Two-Stroke-Cycle Principle
The main reason for the four-stroke cycle having
been so universally adopted is that the scavenging of
the burnt gases can he accomplished by one stroke of
the main piston. This leaves the entire volume swept
by the piston five for a fresh charge.
The two-stroke-cycle engine which draws the fuel
into the crank case and depends upon scavenging the
burnt gases by means of air is necessarily uneconomical,
because it is difficult to cut off the exhaust gases at ex-
actly the proper point and avoid all passage of the fuel
through the exhaust port. However, when the fuel is
injected on the compression stroke, and pure air only is
drawn into the crank case, this objection is not so serious.
Nevertheless, it is difficult to determine just what air
currents take place inside the cylinder when it is expected
that the incoming air on the one side will drive out the
exhaust gases on the other, especially when both of the
ports are at one end of the cylinder. Fig. 2 illustrates
what probably happens in such a case.
Fuel Injection
Xow, consider the fuel injection and the method of
forming an explosive mixture. The conventional vapor-
izing type of four-stroke-cycle engine draws in a charge
of air past a fuel spray nozzle at a high velocity, frequently
as high as L2,000 to 15.000 ft. per min. This high
velocity, together with the extremely fine spraying of
the fuel, causes cadi particle of air to become laden with
a certain amount of fuel vapor, and thus promises a very
complete mixture.
On the other hand, in the engine with pump injection
the combustion space is tilled with a mixed charge of
air and exhausl gases, with probably some irregular
stratification of the exhaust gases. The fuel pump
188
r o w ]■: r
Vol. 11, No. 6
measures out a given quantity of fuel, which is sprayed
into the compressed air by a hammer blow from a earn or
eccentric which operates the pump. A certain mixture
of fuel with the air and burnt gases takes place, hut a
thorough mixture of the fuel with the air does not exist
(see Fig. 3). Furthermore, this mixture will vary great-
ly from one impulse to the next, depending upon con-
ditions such as stratification of the charge, temperature
of the hot bulb, temperature of the engine itself, nature
of the fuel used, amount of fuel measured out and in-
jected by the pump, size of the opening in the spray
nozzle, condition of the spray nozzle, time in the cycle at
which the fuel is injected, etc. All conditions being
uniform, the results are fairly satisfactory, but there
is necessarily susceptibility to these varying conditions.
These engines are ordinarily rated at a mean effective
pressure of 35 to 40 lb., or about half that of a four-
stroke-cycle engine of the vaporizing type at rated load.
Indicator diagrams from properly designed four-stroke-
cvcle engines of the vaporizing type show that the mean
effective pressures are practically uniform, although in
some eases a pressure of IIS to 150 lb. may be indicated.
Fig. 1 is a diagram from a two-stroke-cycle vaporizing
This is so automatic that the results are dependable
even under adverse conditions.
Timing of Fuel Injection
Different manufacturers commence injecting the fuel
at different points in the stroke varying from the be-
ginning of the compression stroke to about 10 deg. be-
fore the end of the compression stroke. The proper timing
depends upon numerous conditions, such as compression
pressure, temperature of the hot bulb, shape of the hot
bulb and combustion .-pace, location of the spray nozzle,
grade of fuel, diameter of pump plunger, stroke of pump,
etc.
Electric ignition is practically instantaneous, and if
there is a variation of say 10 deg. in timing, the results
obtained are apt to be poor. With an engine running at
300 r.p.m., 10 deg. is equivalent to 0.002 sec. This is
an extremely short time for a mechanical fuel pump to
act and deliver a quantity of fuel against 150 lb.
It is difficult for anyone who has not worked with them
to appreciate the delicacy of these mechanical devices.
If the injection of fuel takes place slightly early, in
comparison with the temperature of the hot bulb, the
"
Fig. •>.. Results ix Two-Stroke-Cycle
Exhaust-Scavenging Type
or Engine
engine at rated load. Mean effective pressures as high
a- this are extremely rare, however, and could not be
depended upon. This point i- brought out to show that
the mean effective pressures from the two-stroke-cycle
hot-bulb engines arc necessarily variable. Furthermore,
it is possible to obtain extremely high initial pressure
if water injection is not used properly, if the fuel is
injected a little too early, or if the temperature of the
hot bulb i- n.it correct. Considering that it is possible
for the-e high pressures to exist, the engine should be
built heavy to withstand them: irregular impulses mean
i rtain service. Fig 5 -hows these varying mean ef-
fei tive pressures.
Measuring the Fuel
Xext consider the method of measuring the fuel. Some
engines govern bj changing the stroke of the pump; oth-
ers through bypassing a certain amount of the fuel back
to the tank. If six drops per stroke is a full load supply
lor a 10-hp. engine, il will readily be seen how delicate
the adjustment must be to govern the speed by reducing
the proportion of the six drops in accordance with the load
conditions.
If the vaporizing type of engine i- properly designed,
the correct amount of fuel will be automatically picked
up a- the throttled air passes over the injection nozzle.
Fig. 3. Showing Small Volume of An:
with Which Fuel Comes in Contact
in Pump-Injection Type
amount of water injection, the temperature of the engine
and the load, etc.. excessive pressure will result.
The Hot Bulb
The mission of the hot bulb is to furnish the high
temperature to assist in vaporizing heavy fuels. If
it- temperature becomes too high, the engine will pound
heavily, due to excessive initial pressure. The hot bulb
will sometimes have a tendency to crack, due to dis-
tortion, because of the unequal temperatures, and also the
fuel may decompose and form deposits on the hot spoon,
-o as to cause cracking of the built. Because of this the
but bulb i- occasionally the source of annoyance and
irregular operation.
Water Injection
If the injection of the fuel could be accurately timed,
so as to bring about the proper flame propagation, and if
this fuel could be introduced into the cylinder in suf-
fii iently large quantities in the very short time existing
tit the end of the compression stroke to prevent too early
ignition, water injection would not be necessary. Engines
that use air injection with the fuel do not use water.
Water injection is the handiest means of avoiding ex-
cessive pounding and high initial pressure, provided the
timing of the fuel injection and the temperature of the
February 9, 191o
row e 1;
189
hot bull), etc., are not correct. It is frequently used in
large quantities, and when the quantity is too greal
excessive wear of the cylinder and piston will take place.
due largely to interference with proper lubrication. In
proper quantities it probably has some tendency to loosen
the carbon, and, in accordance with a theory which has
frequently been advanced, it may result in bringing
about a uniting of the nascent oxygen with the carbon,
450-
o 400-
"^ 350
c
§ 300
V)
250-
15
I'e
t 200-jl
150-
100
50
l. Diagram from Two-Stroke-Cycle Vaporiz-
ing Engine at Bated Load
thus keeping the cylinder slightly cleaner than would
otherwise lie the case.
Lubrication
Some years ago the auxiliary exhaust port in the four-
stroke-cyele engine was considered good practice, and was
extensively used. However, this port was later abandoned
because it interfered with proper lubrication, and a dry
streak through the cylinder was invariably found where
these ports existed. The conditions in this respect are
no different than in the two-stroke-cycle engines of today.
although probably this port does not bring about so much
excessive wear of the cylinder and piston as do the
unburnt fuel and the water. Where crank-case compres-
sion is used, trouble with the lubrication of the main
bearings is sometimes experienced.
Even with very short connecting-rods and with every
available space in the crank case filled up so as to obtain
as high a compression as possible, it is seldom possible to
obtain a pressure in the crank case greater than 2y± to
iy<2, lb. With the wear on the bearings, this pressure has
a tendency to leak out and to interfere with their lubri-
cation.
Leakage of crank-case compression also has a tendency
to seriously affect the operation of the engine, as the
transfer air is thereby lost and scavenging is not obtained.
This condition in conjunction with the filling up
of the exhaust port with carbon, thus causing back pres-
sure, has a tendency to equalize the pressures on both
sides and interfere with proper scavenging. Incomplete
scavenging means loss of power, wasted fuel, over-heated
engine and premature ignition.
Compression
The compression employed by different manufacturers
\aries from 70 to loO lb., some running as high as 300
lb. One manufacturer provides means of varying the
compression in accordance with the fuel used and the
conditions of operation. High compression should mean
greater economy, but at the same time greater danger
of excessive pressures. The amount of compression per-
missible will depend upon the temperature of the hot bulb.
the temperature of the engine itself, the grade of fuel
used, the method of injecting the fuel, and the time
at which the fuel was injected. In consideration of thesi
varying conditions, it is practically impossible to settle
upon a satisfactory all-around compression.
Compression' undoubtedly has greater influence upon
economy than any other one point in connection with the
design of internal-combustion engines. When the ex-
plosion engine was first attempted, no compression was
used, and the engine was practically a failure on this
account. S • fuels will ignite more readily than other-,
and. consequently, are more susceptible to heat of
compression. Producer gas will stand a compression of
from 150 to 160 lb., and natural gas 120 to 130 lb. with-
out premature ignition. When liquid fuels are introduced
into the cylinder of a four-stroke-cycle engine on the
suction stroke, a compression of from (iO to 70 lb. is
approximately all that can be obtained. Because of
this low compression, an economy of less than 12,000 B.t.u.
per b.hp.-hr. cannot be expected.
When high compression can he used, such as 120 lb.
on natural gas. an economy of 8.300 B.t.u. can be ex-
pected. This is the economy, therefore, which an engine
of the pump-injection type should be able to obtain when
using a compression of 150 lb. This economy is not
attained, however, because the pump-injection principle
is so far from perfect. In fact, it is seldom that an
economy of 12,000 B.t.u. is bad; the more common figure
being 14,000 to 16,000 B.t.u.
Fuels
It is common for manufacturers of the hot-bulb type
to state that any fuel can be handled in these engines.
.Most assuredly, any oil which contains heat units will
vaporize when it comes in contact with a red-hot surface,
and will consequently develop pressure and deliver power.
600
■Dangerous pressures
to be avoided
Diagrams from Pump-Injectiom Engink;
Heavy Link Showing Expansion Curve
at Bated Load
This being the case, demonstrations can be made on very
heavy fuels. Their continued success and satisfaction are.
however, highly improbable, and in many cases lighter
grades of fuel have been resorted to because less diffi-
culty is experienced.
Can these engines operate successfully on kerosene?
is a question which has been frequently asked. The ma-
190
P O W B 1!
Vol. 41. No. 6
jority of them do not, if they are built for operation on the
heavier fuel. The flame propagation of kerosene is more
rapid than with fuel oil oi a heaviei grade of distillate.
This fact interfere- with operation on either grade of
fuel, as the flame propagation is dependent upon the tem-
perature of the hot bulb, the timing of the injection of the
fuel, the temperature of the cylinder walls, the amount
of water injection used, and the load which the engine
is called upon to handle. If these conditions are all cor-
rect for heavy fuels, thej are not correcl for lighter fuels.
and except for a small range in variation, they are not
adjustable.
It is true that all of the troubles mentioned do nut exist
in all installations of such engines. In fart, some of these
engines operate without any of these difficulties, but they
have all taken place in numerous instances, and any and
all may take place in any installation.
Present State of This Type
The success achieved by heavy fuel- in this type of en-
gine is due to a peculiar combination of some of the fol-
lowing conditions: The high price id' gasoline with the
consequent desire to handle a heavier fuel: a consequent
response on the part of some manufacturers to build an
engine which they can claim will burn the heaviest liquid
luel>: the fart that a certain vaporization of these heavier
fuels takes place when brought in contact with extremel)
high temperatures ; that there is available in some locali-
ties certain grades of heavy liquid fuels at a low price:
that these engines are simple in construction and simple
in appearance : that they do operate on these fuels and de-
liver power, and in some instances to the expressed sat-
isfaction of the owner: and that this engine is passing
through a stage at the present time when its shortcomings
are being excused, and the owners are loath to admit
that any difficulties are being experienced.
This attitude is due to lark of information regarding
the actual causes of difficulties; consequently, there is a
tendency to consider the troubles as due to improper oper-
ation or some outside influence. Excessive cylinder wear,
lor instance, can be laid to soft metal or to improper at-
tention on the part of the operator: cracked bulbs and
choked exhaust ports may be blamed on the operator or
the fuel used : and blown-ofi cylinder heads or cracked
beds may lie attributed to insufficient water injection or
possibl v defective material.
Proper Fuels
Specific gravity indicates little as to the vaporizing
qualities of a fuel, although the majority of fuels above
38 to 39 deg. gravity vaporize readily and the majority
below 35 or 3(3 deg. gravity do not vaporize readily. The
flash point also tells little, as fuels with a heavy body may
contain sufficient lighter constituents to show a flash at
a low temperature. A definite indication of the quality,
however, is the boiling point, or the temperature at which
different percentages of the fuel will distill.
Vaporizing Type of Engine
Another reason why the heavy-oil engine has been
brought into favor i- the numerous published statements
that the so-called gasolh ngiiic i- not adapted to hand-
ling kerosene and the lighter distillates successfully. While
this has unfortunate!) been proven in some cases, yet
in others the application of lighter distillates to the four-
stroke-cycle vaporizing type lia i essful.
There are many features in connection with the proper
design of the yaporizing type for handling the lighter
grades of distillate and kerosene. There seems to be a
mistaken impression that the carburetor is the essential
feature. While the carburetor should be properly de-
d there are other governing features equally impor-
tant, such as piston speed, ratio of the stroke to bore,
method of water circulation, location of the valves, shape
ombustion space, location of igniter in combustion
space, valve timing, voltage of ignition current, velocities
through valves and intake passages, location of carburetor
in relation to the inlet valve, contour of passages, gover-
nor valve and governor, method of automatically handling
the mixture with varying loads, complete mechanical va-
porization without resorting to preheating the charge,
etc.
Engines Below 15 Horsepower
A large number of these small engines are used for
farm work. They are usually of the four-stroke-cycle
vaporizing type, usiug either gasoline or kerosene. The
farmer should not attempt to use anything heavier than
kerosene for this purpose. He should have an engine
which is easily started, easily handled, and sure to run
on a fuel which is readily obtained in small quantities.
It is doubtful if there is any other manufactured ar-
ticle which will vary to such a degree after it is assembled
as will the gasoline engine. Pistons, piston rings and cyl-
inders which are subjected to high temperatures and ir-
regular distortion must be worn in together. Springs
must be adjusted to the proper tension. Governors must
be put in proper operating condition. Valve timing should
he properly adjusted. Bearings should be worn in to
avoid the possibility of their running hot. Brake tests
should be made showing the engine developing its full
rated horsepower. Water tests should be made of jacketed
casting-, as frequently leaks will develop alter the engine
has been in operation for some time. Moreover, the ig-
nition system should be timed properly and checked up
carefully. Considerable cost to the manufacturer can be
saved by neglecting these matters, but the farmer should
insist that the manufacturer produce an inspection sheet
covering the detailed inspection and testing of the engine.
Conclusions
For many years after the internal-combustion engine
came into general use. there was a current opinion that
the engines were unreliable and tricky. This was brought
about to a considerable extent by placing on the market
a large number of engines which were not scientifically
designed nor fully developed. It has taken many years of
consistent effort to live down this prejudice.
We are now facing to a considerable extent a similar
condition, because of the attempts to use heavy liquid fuels
with a type of engine of cheap construction, such a- lias
heretofore described. Quite a large number of com-
paratively small manufacturers are experimenting with
this proposition, with the result that undeveloped engines
have been and are being placed on the market.
This type may in time achieve the results which it
now claims, but in the meantime its failures should not
be permitted to influence the industry as a whole. This
can be accomplished best by a greater education of the
public regarding the merits and demerits of the different
types of engines, the different grades of fuel, and the pur-
r which the\ can lie used to the best advantage.
February 9, 1915
P O W E R
11)1
By D. L. Rogeb
A small power plant, of interesl because of its unique
design and its economy in steam consumption, is shown
in Figs. 1 and 2. This plant was installed in a 22-ft.
launch and ((insists of a vertical boiler, vertical Eore-and-
al't compound engine and all necessary auxiliaries.
The engine has 3&6x4-in. cylinders and runs al
a speed of 400 to GOO r.p.m. The boiler Eeed pump, air
pump and fuel pump are driven by a drag crank and 2-
to-1 gears from the forward end of the main shaft. The
link on the low-pressure valve-gear is provided with an
adjustment by which the receiver pressure is regulated.
A reheater of U-shaped tubes connects the two cylinders.
The boiler is mounted aft of the engine. It is 12 in.
high by 18 in. diameter and contains I'.'ii half-inch tidies.
The safety valve is set to blow at 200 lb. pressure. Kero-
sene is used as fuel in a special lm mer connected to a tank
on which 70 Hi. pressure is carried'. The breeching carries
the products of combustion through a superheater
mounted on top of the boiler, around the high-pressure
cylinder, through the reheater, around the low-pressure
cylinder and to the atmosphere through a small stack
mounted on the low-pressure cylinder.
Several tests have been made on the plant under work-
ing conditions on Lake Mendota, Wis. Numerous indi-
cator diagrams have been taken of both cylinders and
these .-how a steam distribution which i^ almost perfect.
The engine consumes slightly less than 13 lb. of steam
per brake horsepower-hour. The boiler, cylinders and
Ft.
iwee Plant in Launch
Fig. 1. Front and Rear of Compound Marine Engine
The steam from the boiler passes through a super-
heater, is expanded in the high-pressure cylinder, and
is exhausted through the reheater to the low-pressure
cylinder. After expanding in the low-pressure cylinder
it exhausts into a keel condenser. The condensed water
feeds the -boiler. A filter is used through which the
water is passed from the condenser overflow to the boiler-
feed pump. The makeup water is also filtered.
breeching are so well insulated that it is possible to place
the bare hand on any of these parts without discomfort.
The gases escaping from the stack are exceptionally low
in temperature.
J. C. White, chief engineer of the Capitol Power &
Heat Co., Madison, Wis., designed ami built this plant
for his own pleasure. lie started the work in 1909; the
completed boat was put into the water in 1911.
192
P(> w i: i;
Vol. 41, No. 6
jtesifflm=T^2,5?fi3)iia@ Hims&^llila&i©ir& ana
By John Klemm
For many years the Compania Minera "Las Dos Es-
irellas" S. A., El Oro, Estado de Mexico, Mexico, has been
purchasing its power from a public-service corporation.
The slipping of one side of it- greatest Jam a few years
ago seriously affected the power company for a time and
caused heavy losses to innumerable customers. This com-
pany, being one of the several large consumers, in conse-
quence installed a Westinghouse-Parsons multiple-expan-
sion parallel-flow 1500-kw. steam turbine to generate
three-phase current at 50 cycles and 3000 volts as a
stand-by.
This turbine has a somewhat peculiar history. About
two miles from the plant, in the center of a large masonry
bridge, the trucks on one end of the car carrying the tur-
bine broke down, precipitating the turbine to the river
bed below, some 30 ft. Evidently, it did not wish to be in-
stalled at an SOOO-ft. elevation. The machine was picked
Service Mains
employed, there should be no chance for a steam turbine to
wreck itself so completely as to require a new spindle.
The turbine is not a very complicated piece of machinery;
nevertheless, like any high-class apparatus it is not in-
tended to stand abuse.
In this instance, to avoid further trouble it was decided
to build a new foundation of concrete of the proportion
1 to 3 to 5, directly under the turbine, and do away with
the masonry foundations, so designing the new work that
the turbine would have absolutely no connection with the
building or other apparatus, except the condenser, etc.
The change was made with some difficulty, inasmuch as
the machine bad to be kept ready for immediate use in
case of emergency.
From Fig. 1 an idea can be had of the conditions. The
dotted lines show the temporary timbering. The space
directly beneath the turbine, between the old masonry
walls, was dug up and the concrete footing A laid. Wall
B was built up to 5 in. below the 15-in. I-beam shown,
and 12xl2-in. and 8x8-in. timbering was placed between
the new wall B and the old wall at C. This green timber
was kept wet to prevent it from shrinking, so that the
" New. Concrete', work ' '•'. .._•.
Pig. 1. Replacing a Turbine
Foundation
up uninjured except for a few paint scratches, and was
installed and operated according to its specifications.
Shortly after, the turbine wrecked itself so completely
that an entire new spindle had to be purchased. Failure
to start the auxiliary oil pump, unintelligent operation
and weak masonry foundations, causing severe vibrations,
were the causes, and conditions were made worse because
of a 200-hp. compressor, operating on practically the same
floor and foundation, whose vibrations caused a harmonic
with the turbine vibrations. Another fault was that the
I-beams were set directly on the masonry wall instead of
being placed on some sort of material to distribute the
weight; the I-beams thus sank into the masonry, and the
machine, instead of resting on the entire length of the
foundation wall, was practically where the I-beams had
sunk.
At the time of the wreck, when the top half of the
cylinder was raised someone remarked: "Que buena en-
salada" ("What a fine salad"), adding the opinion that
the most inefficienl Corliss engine is far better than the
most efficient steam turbine ever designed. This is a nar-
row-minded and prejudiced view, obviously untrue. The
-team turbine has already proved its value, otherwise
30,000-kw. units would not be designed and operated, as
they are today. Where intelligent and attentive labor is
Fig. 2.
To Feed Pumps
Old Boiler Used as
Heatee
From Air
Compressor Tank
\ Peed-Wateb
weight of the turbine could not come on the condenser.
The old wall at C was then removed, a new concrete foot-
ing laid and the wall C built up and steamed to crystal-
lize the cement, which was done in about 60 hr., thus
avoiding the slow 28-day process.
For the steaming %-in. pipe, previously drilled with
i/g-in. holes about 6 in. apart, was laid all around the
bottom of the wall ; the entire wall was then well covered
with a heavy canvas and the steam turned on. At the
beginning the temperature was held below 35 deg. ('., then
gradually increased to 70 deg. C, at which it was main-
tained for the last 12 hr. Great care must be taken not
to overheat the concrete and thus ruin the entire work,
especially if it is reinforced, as the coefficients of expan-
sion for iron and concrete are different. The steam pres-
sure never exceeded 1.5 atmospheres, and with this it was
found that the best work was done on the top of the wall.
After the steaming the electrical end was dried out before
being placed in service, to avoid danger of a burnout.
Full-length 40-lb. steel rails were then placed on the
new walls I! and O, Pig. 1. and 1-in. plates and steel
wedges set tighl against the 15-in. I-beams on which
February 9, 1 9 1 5
PO WE L!
193
rested the turbine bedplate. These rails served to dis-
tribute the weight of the machine over the entire length
of the walls. All spaces between and around the rails and
[-beams were then filled in with concrete to the level of
the bedplate, making of the whole almost a solid box-like
construction with the opening in the center. It may be
criticized as inconsistent with uptodate construction not
in allow more space below the unit, but this could not well
be avoided, under the existing conditions; moreover, the
space was sufficient, as all high-speed machines, especially
turbo-generators, have artificial ventilation, cold air being
Mown into the windings. Without this precaution the
air in the machine while it is running would be churned
and would seriously affect the temperature rise.
The timbering was finally removed and the I-beams,
one end of each of which was still in the old wall, were cut
in a diagonal direction, as shown by Fig. 1, so that in set-
tling, the I-beams could not again make contact with the
old work, the tendency being to settle away.
An additional installation of three tOO-hp. Babcock &
Wilcox water-tube boilers brought the total boiler capacity
up to 2400 hp. This addition may seem unnecessary, and,
hence, a useless expenditure, but steam is always required
for purposes other than power generation, and it is de-
sirable to have ample margin for cleaning, etc. Further,
it does away with the need for induced or forced draft
and attendant loss of heat up the chimney, the extra cost
of the apparatus and the disadvantages of boilers.
There are no peaks to consider; the load is steady
throughout the 24 hr. The lighting load at night is hardly
perceptible. The boiler feed water is taken almost directly
from the condenser, a 4-in. pipe being tapped into the
12-in. discharge pipe of the circulating condenser pump
(see Fig. 2). This 4-in. pipe discharges into an old lire-
tube boiler use. I as a heater, and the water is then brought
up to 90 deg. C. from the heater. It flows by gravity to
the feed pumps, of wdiich there are two Worthington
10x6xl0-in. The pumps are also connected to the Al-
berger cooling tower and a tank, which is used to cool a.
200-hp. Ingersoll-Eand compressor, so when the turbine
is not in operation the boilers still get warm water.
Steam is required for other purposes lor 2 1 hr. daily, and
is held for emergency. The heater is also connected to
the company's service mains through a small storage tank
above the heater, as Fig. 2 shows.
There are two wrought-iron expansion joints in the
8-in. steam header line, one I' between what are known as
Xo. 1 ami No. 5 boilers, and a 90-deg. elbow between
Xo. 1 boiler and the turbine. These suffice to take up
any expansion in the header.
American fuel shipped to these regions comes high,
costing on an average about $24.50, Mexican currency.
per ton of 1000 kg. (2205 lb.) on the plant grounds.
The generator room is 39 ft. 8 in. by 89 ft., and is con-
structed of masonry. The doors and windows have a
brick facing, presenting a neat and attractive appearam e.
The boiler room is :i!) ft. 8 in. by 92 ft., and is constructed
of the same class of material.
Coal Storapre Tests — In his annual report as Chief of the
Bureau of .Steam Kngineering, Admiral R. S. Griffin says: "The
eoal stored at New London under the three different conditions,
in the open, under cover, and under water, was given the
third annual evaporative test. Xo marked difference in evap-
orative efficiency was shown between the coal stored under
different conditions, and no conclusive evidence developed as
to the best method of storing coal."
This trap is of the closed type, with the moving parts
arranged inside the apparatus. It operates automatically
when sufficient condensate has accumulated to move the
float. It has few moving parts; therefore friction am!
wear are reduced to a minimum, and then- are no stuffing-
boxes.
The trap is made with a cast-iron body, brass inside
parts and an open copper float. It is built for working
pressures up to L80 lb. For higher pressures the body is
made of steel.
In operation the condensate enters the trap at A and
flows through opening B into the body. The water level
inside of the apparatus rises until it reaches the top of the
open float C, which is shown in its highest position. The
float tills, loses its buoyancy and starts to sink, carrying
with it the stem 1). which pulls dow lever E. This
lever, turning on the center /•'. opens the steam valve G.
As the float continues to sink, the roller II come- in
contact with the short arm of the lever /, which, turning
Section through Return Steam Trap
about the center A", throws the attached counterweight L
over to the left until the long arm of the Lever presses
on the roller II. The weight, falling over to M, will
cause the roller, which is already in contact with the
steam-valve lever E. to drop quickly. This oives a sud-
den increase in the opening of the steam valve, and the
full pressure of the steam ads on the water in the trap,
discharging it through the pipe A, the chamber 0 and
the outlet P. A dashpot R takes up the shock caused by
the counterweight falling on .1/.
A check valve on the inlet A prevents water from enter-
ing the intake pipes, and another in the discharge
line prevents the return of the discharged water.
The empty float rising, throw-, the counterweight back
to its original position and releases the lever E. allowing
the steam valve to close. As the floal continues to rise,
the roller S lifts the lever E and opens the valve T. thus
relieving the pressure in the trap. The steam which flows
through this valve is received in a tank and condensed.
This trap IS manufactured by the General Condenser
Co., 1240 North 12th St., Philadelphia, Penn.
194
r 0 W" E R
Vol. 41, Xo. G
Amnremitl
By F. A. Axxett
SYNOPSIS — Direction* for systematically locat-
ing the trouble, should a motor fail to start when
the starting-box handle is thrown over.
When locating trouble in a motor, it is essential that
certain features be given first consideration. Assume a
ease where the motor fails to start because of a blown
fuse (/', Fig. 1 ) . The first thing to ascertain in all
such cases would be if the line is alive. This can be
determined by connecting a lamp or voltmeter as at L.
f, which may be removed and again tested, to make sure
that a mistake has not been made in the test. This can
be done as indicated in Fig. 3. If the fuse is blown, the
lamp will not light.
If link fuses are used, the fact that they look good
should not be taken as final, for a fuse may be broken
nil' close to one of the terminals, and although it may look
good on inspection, it is nevertheless open. Another
point that should not be overlooked is the switch. One
of the clips may be worn or sprung just enough to pre-
vent it from touching the blade. Therefore, if the fuses
How in Locate the Fault When the Motor Wilt. Xot Start
If the lamp lights, next test below the fuses as at L' . In
this case it will not light, for the fuse /' is blown.
Most inclosed fuses indicate when they are blown, but
this cannot always be relied upon, and when locating
trouble the best policy i> to depend upon nothing but
what has been determined by test. To test the fuses
H ithout removing them, connect the lamp as illustrated
in Fig. 2. If the lamp is connected as at L, it will light,
indicating that fuse / is not defective. When connected
as at IS, it will not light, for the circuit is open in fuse
test good, do not neglect to test the switch and see that
the clips are making good contact and that none of the
connecting wires are broken at the switch terminals.
If the break is in some part of the circuit other than
the fuse, such as at A' in the starting resistance. Fig. 4,
an indication that the circuit is alive will be given when
the starting arm is brought up to the first or second con-
tact and allowed to drop back to the off position; that is.
a spark will occur when the field circuit is opened.
If the motor does not start on the first or second con-
February 9, L915
P U \Y E B
1U5
nut point, bring the arm back to the off position and look
for the cause. If it. is loaded, firsl determine whether
the load is free so that it can be started; also, thai the
motor bearings arc not sel on the armature shaft or worn
bo as to allow the armature to rub againsl the polepiei e
The writer recalls an instance in which he was called
in to repair a pump motor that another electrician had
been working on all day, trying to get it to run. [Jpon
attempting to turn the pump over by hand, it would
in >t move, and the eause was traced to freezing of the
pipe line running to the roof tank. There was nothing
wrong with the motor or controller except what was
caused by the ordeal they had been put through during
the day.
After it has been determined thai everything is favor-
able for the motor to run. the next thing is to make an
inspection of all the electrical connections to see that
they are tight and making good contact and that none
of the wires are broken off at the connections; for some-
times a wire breaks off and will open only enough to in-
terrupt the circuit, and unless it is moved it cannot be
detected. If lugs are used on the wires, see that they
are properly soldered, for if this has not been thoroughly
done the wire will corrode in the connection and may
eause an open circuit. All this is a hard and fast rule
which may he applied to any motor whether direct- or
alternating-current. Furthermore, it is well to make
.-ure that the brushes are making good contact on the
commutator and are free in the brush-holder poekets.
If the foregoing has failed to disclose the reason
I'm- the motor not starting, nexl test for purely electrical
troubles. In this connection. firsl tesl the starting de-
vice. Fig. o shows a convenient way of doing this. Dis-
connect the armature and field connections on the start-
ing-box and plai . the arm on the first contact, as shown.
Then connect one lead of the test lamp to the switch
terminal S (the one connecting directly to the motor),
and to make sure that everything i< in condition to
make the tot. connect the other lead T of the lamp to
tl ther -witch terminal S'. If the proper indication
i- had. next connect lead T to the ""L" (line) connection
'mi the starting-box. If the lamp continues to light,
connect lead T to terminals ,1 and F. as indicated, which
in the present case will show a complete circuit through
the starting-box to the terminal F, as indicated by the
arrowheads, hut not to terminal A, for the resistance is
open at .V. That is, when connected to F the lamp will
light, but not when connected to .-1.
The exact location of the fault can he easily deter-
mined by testing to the contact- on the resistance. If
lead T of the lain]) is connected to contacts <<. / or </.
which are to the right of the break in the resistance, the
lamp will not light, but when connected to d it will light.
Since the lamp lights at <l and not at e, it indicates that
the circuit is open between these contacts.
A quick way to repair this fault i< to drive a piece of
fuse wire in between the contacts on the front of the
-late between which the fault is located. A better and
more permanent way i.- to remove the cover from the
starting-box and repair the break in the resistance coil.
If this cannot be located, as in some cases the .nil- are
molded into a compound, the two contacts can he con-
nected together on the hack of the -late with a piece ,,f
wire.
In fig. 6, A .-how- a break in the wire which connects
the series and shuril fields direct to the switch. If the
tests previously described are made ami the circuit
through the starting-box ha- 1 n found complete, the
nexl step will he to disconnect tin- two connecting wires
between the motor and the starting-box, at the machine.
and tesl through them as indicated. This will show a
closed circuit. ;i- represented by the arrowhead-. Nexl
conned the armature and Held wires to their respective
terminal.- and test through the armature and tield coils,
as in Fig. ',, ami if they arc not defective the lamps
should light.
There i- hut one thing left to test and that is the con-
necting wire from the switch to the series and -hum
field connections. To do tin-, connect one lead of the
lamp to the switch terminal 8' and the other to the end
of the wire at the motor, as indicated in Fig. 8. In
this case it will not light, which indicates that the cir-
cuit is open between the switch and the other end of
the wire. The defect may then he definitely located and
repaired, or the wire replaced by a new conductor. If
the wire- are in conduit or molding, the defective one
should he replaced by a new wire, for a spliced wire in
molding or conduit i- a violation of the Board of Fire
Underwriters' rules.
A practical way of testing for an open circuit in the
starting resistance is illustrated in Fig. 9. Close the
-witch and bring 1 he starting-box arm upon the first
contact, and then bridge between the contact buttons
with a piece of metal ; a screwdriver being convenient for
this purpose. If the break is in the shirting resistance,
such a- between </ and e, the motor will start when the
defect is remedied: then the switch may he opened and
the fault repaired, a- previously explained.
An open circuit in the .-cries field may he located as
described in "Testing for open Circuits in Field Coil.-."
(Power, Aug. I. L914).
This old boiler which the owner had recently purchased
was being given a "tryout" on a wood saw. The engineer
said the engine ran "snappy"' with the throttle valve two
Engine's Position after Explosion
turns open, which i- taken as indicating that there was an
i xeessively high pressure in the boiler, although the steam
showed only so lb. and the safety valve was -et. by
the same gage, to blow at 100 lb.
P 0 W E I!
Vol. 41, No. (i
The failure occurred at the bottom of the firebox, of the
water-bottom type, where there was a section approxi-
mately 26 by 30 in. without stay-bolts. This section was
forced upward, throwing the grate bars out through the
iire-door. One section in its flighl struck a dinner pail
:■:
carried by a schoolboy, who was passing at a distance of
about 200 ft., tearing it from the bail. The force of the
explosion impelled the engine forward, nearly overturn-
ing it on the woodpile, as shown in the illustration. Two
men were slightly injured.
Boil
'F!
BY ( ISBORN MONNETTf
SYNOPSIS — Smoke prevention in typical metal-
lurgical furnaces operated in connection with
waste-heat boilers. The latter are provided with
n I furnaces.
Quite frequently the hot gases from metallurgical fur-
naces are available for steam making. When boiler
!op right, 1915, by Osborn ilonnett.
[■Smoke inspector, City of Chicago.
X
0HE2SOM m ■,, gaLCH --■■: f HE 2
TW036\l$6'DRUHS. 4-S'CENTERS
SIX ROWS !6WIDE.SR0iVS 15 WIDE.
I7l-3i 'TUBES
CRATLS S'lOH0 I0WIDE-60SQFT
■
DEFLECTION ARCH 3(2-6 'x?'-0 ')
:7S5SQH
AREA THROUGH 1ST FUSS 4'0'x9'0-36 SOFT
AULA THROUGH 3ST T»SS3:9'x90''iATSSIiFr.
AREAOF UPTAKES lll-3'x6'-0')'l35SQ.FT.
&.Etcnji>'iir>ESZ(:e ■■:-. >•.»: v.-v
UREA OF STACK 9 6 SOFT
STACK 3:6 'DIAH. X Ili'-O'fDIRECT)
f HEAT FROM FURNACE
Fig. 1.
Typical Waste-Heat Boiler Setting with
Auxiliary Hand-Fired Furnace
Fi<
, 2. Waste-Heat Retubn-Tubulab Boiler and
Forging Furnace with Underfeed Stoker
combined with such furnaces it is sometimes desirable to
so arrange them that they may be fired by hand when the
furnace is down. In this case provision for smokeless
opi ration can be made by installing one of the hand-fired
furnaces shown in previous artii les. Care must be exer-
i ised in selecting a furnace adaptable to the particular
type of boiler being used.
A typical installation is shown in Fig. 1. This boiler
re eives the waste gases from a billet-heating furnace, the
gases coming through the perforated side walls of the
setting. When this furnace is not in use the boiler can
be fired by hand in the usual manner. As shown, the
ONE I50HP. CAHALL VERTICAL BOILER AREA OVER BRIDGE .'itfZZ s'e'xl'-O'-
HEATING FURmCE-UNDEK-FEED STOKER T5S0FT(HKW0E/SLAIlFSE6HEm S:6-)')
GRATE AREA 5-6'L0N6x4'-6"=22.75SQfT. AREA OF FURNACE THROAT ZxlY-lSSQFT
HEATING AREA! I2'L0NGx6-6'= 75SQ.FT. STACK AREA TSQ-FT
RATIO OF GRATE TO FURNACE HEATING SURffKE 1T0329 STUCK 36 'OKfl. X 87:0 '
J- U^X^^^^^
Fig. 3. American Underfeed Stoker and Heating
Furnace Connected to 150-Hp. Cahall Ver-
tical Waste-Heat Boiler
■ ■ ~~
Fig. 1. American Underfeed Stoker and Forging
Furnace with L12-Hp Firebox Boiler
setting sists of a standard tile-roof furnace, with de-
flection arch, siphon steam jets and panel doors. Many
metallurgical furnaces have underground breechings and
it is generally simple to lead the gases to the boiler.
The underfeed type of stoker is especially adapted lot
the smokeless operation of metallurgical furnaces because
it Joes not depend on natural draft for its air supply.
February 9, 1915
P U W E I!
197
Owing to the length of the gas passes and number of
turns, etc, there is generally but little suction over the
fire from natural draft. Any stoker depending on natural
draft and an ignition arch is at a big disadvantage from
SECTION C-D
Pig
5. Jones Underfeed Stokeb and Malleaisle-Irox Melting
Furnace with 400-IIp. Wickes Waste-Heat Boilek
merely indicate how Lhe differeni combinations ran be op-
erated without smoke.
Forging furnaces are often connected to waste-heal
boilers, as the steam raised by the boilers can be used to
advantage in the steam hammers, the
same fuel sufficing for all operations
in the simp. Fig. f shows an interest-
ing and compact installation of this
kind, consisting of a 112-hp. firebox
boiler over a forging furnace fitted
with an underfeed stoker.
When hand fired, the malleable-
iron melting furnace produces a
great deal of smoke. The underf I
stoker can be applied to this furnace
with ad\antage and the waste beat
used for steam making, as shown in
Fig. •"). The latter consists of a 100-
hp. Wiekes waste-heat water-tube
boiler attached to a melting furnace
using an underfeed stoker and hav-
ing an auxiliary hand-fired furnace
for emergency purposes. With a by-
pass to the stack the melting fur-
nace can he operated when the boiler
is down for cleaning or repairs. Also,
the furnace can be cut off from the
boiler and the latter operated inde-
pendently by closing the firebrick
curtain-wall or damper, as indicated
in the drawing. This makes a flexible
combination. Another forging fur-
nace with a Jones self-cleaning un-
derfeed stoker is shown in Fig. 6, at-
tached to a Wiekes waste-heat boiler.
v
Belt-Driven «'<«.-il Crushers— The Kdi-
son Klectric Illuminating Co., Brook-
lyn, N. Y., has found it advantageous
to sacrifice plant efficiency obtained by
using steam engines and to use motor
drive with belt transmission for driv-
the standpoint of maintenance and capacity. An under-
Iced stoker will operate satisfactorily under conditions
where a natural-draft stoker would burn up from the heat
bottled in the furnace.
Fig. 2 shows a waste-heat boiler of the horizontal re-
turn-tubular type installed in connection with a reheating
furnace having an underfeed stoker. The boiler itself
is equipped for hand firing, an ordinary No. 8 furnace
containing a pier and wing walls being installed behind
the bridge-wall. The usual rules for furnace areas based
on the grate surface are allowed. If the boiler is to be
used much, independently of the waste-heat furnace, the
same stack height required by an independent boiler
should be provided.
Another combination of metallurgical furnace and
waste-heat boiler is shown in Fig. 3. In this case the
ratio of grate to metallurgical heating surface is given
as 1 to 3.29. The gases pass up through the lower drum
of a specially constructed Cahall vertical boiler. Ob-
viously, the proportions of the furnace depend on the
product to be heated, so that the design must he varied to
suit the conditions. The accompanying illustrations
Fig. 6. Jones Self-Cleaning Underfeed Stokeb i\
Forging Furnace and Wickes Waste-Heat Boiler
ing its coal crushers, as an obstruction in the crusher will
cither throw the belt or open the motor circuit-breaker in-
stead of breaking parts of the crusher. Car couplings and
pieces of steel frequently passed into the crusher with the
coal, which stopped the rolls and the engine with a shock,
thus subjecting the parts to excessive stresses. With belt
drive the crusher and motor are protected against injury.
198
POWER
Vol. 41, No. 6
Service
By Charlk
SYNOPSIS — The article takes up briefly some
of the more important points to be considered in
the selei Hon of a pump for general service in con-
nection with power and industrial plants.
When the water is taken Erom the public mains or
flows tn the plant by gravity, the problem is simple and
usually involves only the proportioning of pipes to the
pressure and volume required. When the power house
is at a higher elevation than the source of supply, the
water must he pumped. If the conditions are such that
the friction head in the suction pipe, plus the elevation,
does not exceed fifteen to eighteen feet, the pumping
equipment may be placed in the power house ; otherwise, it
must lie located at some intermediate point where this
limit will not be exceeded. Direct-acting steam pumps,
engine- and turbine-driven plunger pumps and centrifugal
pumps are adapted to the first of these conditions, and
also to the last when the distance is not so great as to
make the carrying of steam from the power house both
expensive and wasteful. When the distance exceeds a
certain limit it is usually better to drive the pump by an
electric motor or gasoline engine than to install aud care
for a special boiler.
When the water is taken from a river, and the grades
are suitable, a hydraulic ram may be employed where
there is an abundance of water. This device is made in a
large number of sizes and requires practically no atten-
tion, as the only parts subject to wear are the rubber
valve-disks. With artesian wells there are two methods in
common use for pumping the water. In the first, each
well is equipped with a lift-pump driven by steam, elec-
tricity or gasoline, and connected with a common main
leading to the power house. The second method makes
use of the "air lift" and is especially adapted to cases
where it is desirable to increase the flow and to plants
using a series of wells, as one compressing outfit in the
power house may he made to do the entire work.
Direct-Acting Steam Pump
This type is made in a variety of forms and sizes and
is widely used for power-plant work. Piston pumps are
adapted 1" locations where tin.' water is free from grit or
other substances likely to destroy the packing. When these
are present, the plunger pump is preferable on account of
the ease with which the worn parts may he repacked or
renewed. One of the chief disadvantages of the direct-act-
ing pump is i t > excessive steam consumption as compared
with an engine or turbine, hut this i> offset in many cases
by the low cost of installation, convenience and ease with
which the speed may he regulated to meet varying require-
ments. Pumps of this type are made single, duplex,
simple and compound, according to requirements.
Direct-acting pumps have an average mechanical ef-
ficiency of 65 to 75 per cent, and a "slippage" of 15 to 20
per cent, under ordinary conditions <<( adjustment. The
steam consumption of small and medium duplex pumps
L. Hubbard
wdl run from SO to 160 lb. per developed horsepower,
per hour, according to the size. By compounding, this
may he reduced from 10 to 50 per cent. Pumps of this
type are operated at a comparatively low speed, although
the steam consumption per unit of work decreases as the
speed increases. For large sizes the piston speed is usually
limited to 100 ft. per minute, but for strokes of less than
twelve or fourteen inches, the piston speed should be re-
duced proportionately. Pumps which are to run con-
tinuously should he designed to operate at about one-half
the maximum allowable speed uoted above.
Power Pumps
Power or geared pumps are used for practically the
same purposes as the steam pumps just mentioned, but
they are more economical to operate as they may be driven
by an engine, turbine or motor. When belted to line shaft-
ing or driven by prime movers requiring a constant speed,
they are not so desirable as the steam pump, owing to
the difficulty of regulation. When used for supplying
tanks and reservoirs or other purposes where they may be
Showing Principle of Air Lift
run at constant speed for long periods, they give satisfac-
tory results and are supplanting the steam pump in many
lines of service.
The efficiency of the triplex pump may be taken as
about (50 per cent, for total heads of 100 ft., 70 per
cent, for 800 ft., and 80 per cent, for 300 ft. The slippage
is usually from 15 to 20 per cent.
Centrifugal Pumps
Pumps of this type have come into general use with
the advent of the electric motor and the steam turbine.
These are of two general forms, the "•volute" and the "tur-
February 9, 1915
po w e i;
199
bine," varying chiefly with the interior construction of
the casing.
The volute pump is usually single-stage, and limited
to heads of 100 to 120 ft., although two-stage machines
are constructed for much higher pressures. Turbine
pumps are designed for high lifts and are usually com-
pounded in order to reduce the peripheral velocity and
thus reduce the friction. It is important when using
a centrifugal pump of any type to select one desi
for the conditions under which it i- to operate.
b' a c pressor in the power house, the air pipe follow-
ing the line of the water pipe.
The lank I) is for equalizing the pressure and reducing
the pulsation between the strokes. The distance /.' is
called the "submergence," G the lift, and A the total head.
In practical work the submergence is expressed as a per-
centage of tie' total head. For example, if A and B are
250 and 150 ft., respectively, the submergence is
The efficiency
centrifuffa
omnionlv
1 5( l
aso
0.60
or 60 per cent. The efficiency of an
air lift increases with the percentage
of submergence and commonly runs
From about 30 per cent, for
B
A
= 0.5
Fig.
Drain Pipe
Fig.
Methods of Connecting Hydraulic Rams
;p to 50 per cent. for
B
A
- u.s
from 60 to 80 per cent, for the better types, working under
the conditions for which the} were designed. The slip-
page varies from about 20 to 60 per cent., according to
size and construction.
Among the advantages of this pump are simplicity and
compactness, absence of valve-, low cost, uniform delivery
and high rotative speed, adapting it to direct connection
with motors and turbines. On the other hand, it is not
possible to obtain as high an efficiency as with the best
designs of piston pumps when the latter are kept in first-
class condition. Furthermore, the speed cannot be varied,
except within narrow limits, without loss of efficiency.
Deep-Well Pumps
Deep wells are of two kinds — open wells having a
large diameter, and driven or artesian wells. The type
of equipment required in the first case consists of one or
more pump cylinders placed within eighteen or twenty
feet of the surface of the water and connected with some
form of pump head at the top of the well by means of a
long rod. The water is raised to the cylinder by suction
and is then lifted or forced from this point to the surface
of the ground.
With an artesian well an outer tube i- driven to the re-
quired depth, extending to the surface of the ground. In-
side i>f this, submerged in the water near the l>otti>in. is
the "barrel" containing the pump bucket and foot valve.
The bucket or plunger is connected with a pump head at
the top of the well by means of a wooden sucker rod, this
material being used in order to reduce the weight. Pumps
of this kind may be operated by a direct-acting steam
cylinder or by a geared electric motor or a gasoline engine.
Deep-well pumps have an efficiency of 40 to 50 per
cent, and a slippage of 10 to 15 per cent.
An; Left
The principle of the air lift is shown in Fig. 1. A water
pipe is carried down to the required depth, together with
an air pipe either on the outside or the inside, as con-
venient. Compressed air is forced into the water pipe
near the bottom, thus decreasing the density of the water
within it, due to the air bubbles, and an upward flow is
produced by the difference in weight between the column
of solid water and the mixture of air and water. Air
under sufficient pressure for raising the water is furnished
A ratio of about 1 to 6 between the areas of the air and
water pipes gives the best results for average conditions.
If the air pipe is too large, power will be wasted in a high
water velocity, ami if too small, the air bubbles will not
expand sufficiently to fill the discharge pipe, but will rise
through the water without lifting it.
Hydraulic Ram
This oilers the cheapest means of pumping where there
is a sufficient supply of water and suitable grades.
Two general methods of connecting a hydraulic ram
are shown in Figs. 2 and 3. If the drive pipe is too long,
the excessive friction will interfere with the proper action
of the ram, and if too short, water will be forced back
into the drive tank. In practice it is customary to make
the length of drive pipe equal approximately to the lift
(It ) to the tank or reservoir. When it is necessary, for
any reason, to locate the ram at a greater distance from
the source of supply, the required length of drive pipe can
lie secured by introducing a standpipe or intermediate
drive tank nearer the ram, as shown in Fig. 3. For large
quantities of water the fall from the source to the ram
should not be less than two feet and, unless special pro-
visions are made, should not in general exceed twelve or
fifteen feet, owing to the shock when the flow is suddenly
checked in the drive pipe.
Standard rams are made in large si/,>s. using from
400 to 15.000 gal. of water per minute (G) , operatin,Lr
under a fall of li/2 to 50 ft., and raising water 35 ft. per
foot of fall, up to a maximum of about 800 ft.
The working formulas for the hydraulic ram are as
follows :
H =
2 X<iXH
:i X k '
3 X A X (r
2 X 6 '
G =
3 X h xj
2 X //
2_X <r X //
3X?
in which
g = Gallon- discharged by ram:
G = Gallons required for operating the ram;
H = Fall, in feet, from source of supply to ram:
li = Height, in feet, to which water is lifted above
the ram.
200
P 0 W E K
Vol. ll, No. 6
By W. V. Howles
Although coal is bought for evaporating water, few
buy it on an evaporative basis. The reason usually given
is that the human element or "error" cannot be accounted
or compensated for. Most engineers agree that the evap-
orative basis is the correct one on which to buy coal.
Assume a plant which requires, say, 3000 or more tons
of coal a year, and it is desired to purchase coal on an
evaporative basis. The first thing to do is to run a test
on the boilers with various coals and make a chart from
the records obtained. The accompanying chart is plotted
PerCent Boiler Rating
Chart
from a stoker plant and illustrates the idea and plan of
procedure.
It is understood that the coal company should have
a competent representative present during the test and at
the calibration of all instruments and to have access
to all records. First, the attainable evaporation and C02
curves are plotted at all boiler loads, together with a
curve showing the best draft to use. Below is plotted a
curve showing what is in the plant, termed "the adopted
standard." This is based on a longer test when uncon-
trollable conditions may be taken into account.
The chart is also divided into a number of time periods,
hours or days, as may be found most suitable. As each
period is ended the average boiler rating is marked at
the top, and below is plotted the adopted standard.
Eeferring to the charts under period 2. it is found that
the average rating was 150 per cent. The equivalent evap-
oration should be 10.4 lb. per pound of coal, but the actual
evaporation fell off to 10 lb. Following down the column,
may be found the reason. The CO., dropped from 12y2
to 12 per cent. Following still further down the column,
the draft has increased from 0.16 to 0.175 in., showing
the operating force to lie at fault. A similar condition
is indicated in the next column.
Under period T the evaporation dropped 0.069 per
cent., but the operating conditions were according to
adopted standards, when the coal company is penalized an
equivalent of 0.069 on the coal burned during that period.
If a better evaporation is gained than is shown by the
standard line, as in period 10, the coal company is given
a bonus equal to the increase; in this case. 0.092 per cent.
If a shipment of bad coal comes in and the operating con-
ditions are allowed to deviate from the standard, both
will be shown in their correct proportion.
It may be found desirable to add draft lines to show
conditions in other passes of
B w 15 16 n is 19 the boiler, also temperature
curves from the various
passes. With proper cheeks
on drafts, temperatures and
('( L, the human element can
be accurately checked and
accounted for: so there ap-
pears no good reason why
the human element should
control or influence the pur-
chase of coal on an evapora-
tive basis.
Such a chart should be an
excellent thing to carry
along from day to day for
the benefit of the plant, even
though it is not intended to
buy fuel on this basis, for it
will show the value of the
firemen in dollars and cents.
Like all other kinds of
record keeping these charts
require much time to be
made out. But in plants
large enough to warrant
checking of performances
of apparatus a clerk is
available who can plot
curves from the tabular
matter given him. Cross-section paper may be purchased
that will fit nicely into large loose-leaf book covers.
'*!
Conditions Are Reversed in Making tins — The steam en-
gineer aims at minimum CO and maximum C<\., while the gas
producer engineer strives for maximum CO and minimum
CO:. A boiler works with a fuel bed usually varying in thick-
ness from 3 to 12 in., whereas the depth of fuel bed in the
producer varies from 2 to 10 ft. Maximum temperature in
the furnace is the ambition of the fireman; on the other hand,
a combustion zone of approximately 2000 deg. F., but varying
with the nature of the fuel, gives the best results in the
gas producer.
Philadelphia Municipal Lighting Plant — It is said that defi-
nite plans are being drawn up by the city of rhiladelphia for
the establishment of a municipal electric-lighting plant, which
is to be ready to take over the lighting of the streets by lOlfi.
It is understood that the plans of the Mayor, and Director of
Public Works Cooke, contemplate the installation of a muni-
cipal electric plant at the old Spring Garden pumping station
of the water-works, and the Keystone Telephone Co. has been
asked for an option on the use of its underground conduits
for the distribution system. The action was brought about
by a recent decision of the State Public Service Commission.
that a municipality has the right to establish a lighting sys-
tem of its own without authority from the Commission, so
long as it does not attempt commercial lighting.
February 9, 1915
p <>\v e i;
20]
Quite a few letters commenting on Mr. Pagett's arti-
cle on tliis subject in the January fifth issue have been
received, for the subject, broadly, is of interest. Nothing
new or valuable is contained in these letters and for this
reason we do not publish them. The writers, with few
exceptions, recognize the fact thai local conditions vary
so widely that one should not expect to find a uniform
wage over several sections of the country. These letters
reflect the g I judgment of power-plant men by claim-
ing that it is right that there is no wage standard among
engineers. The very nature of the service precludes such
a thing if equity to all is to be had.
If an engineer's duties consisted chiefly of a few move-
ments, physical or mental, if there were men a remote
possibility of "Taylorizing" him. if there were a sem-
blance of standardization about his routine, then well
enough to talk about a standard wage. But these things
cannot be. The individual's service is the only true
measure of his worth.
C©SiIU§giviiin\g| (?) D©p©
There seems to be an epidemic of coal-savers on the
market — not methods and apparatus for saving coal in
a legitimate way, but nostrums which, sprinkled upon
the coal, are claimed to greatly intensity its calorific value
or at least the efficiency with which it can be burned.
As the rustic visitor to the circus said of the giraffe,
"There ain't no such animal."' And even as the rustic-
said it in the actual presence of the beast, we reiterate it
in the face of claims of results produced and testimonials
to savings supposed to have been accomplished.
There is no substance known to man which, sprinkled
upon coal, will make it evaporate more additional water
than the extra coal which the price of the dope would
have bought could generate. Let us make a slight reser-
vation. There are some coals which, thrown upon the
fire, will immediately disengage a lot of volatile? like
a hunch of kerosene-soaked waste. A little water sprinkled
upon such coal will retard this action and perhaps save
enough in volatiles which would otherwise escape, to more
than offset the loss of the heat required to evaporate the
water. But the action is as described and not due. as is
often claimed, to the combustion of the decomposed
water; for it takes just as much heat to decompose the
water as it generates in getting together again.
We got caught once with one of these concoction-. We
told the promoter that if he would have a test made of it
by a competent and reputable engineer, and if it showed
a material saving, we would publish the test and proclaim
the results, lie let us choose the authority, and to our
astonishment the test showed from seven to sixteen per
cent, better evaporation with the dope than without it.
The files of Power will show that we carried out our
promise; but even with the treated coal the evaporation
was only six and a half to seven pounds, ami a very lit-
tle difference in manipulation would account for the
bringing of a wretched performance up to tin- not much
better one. That our skepticism was warranted is shown
by the fad thai the stuff was never able to hold its place
upon the market.
This was many years ago. Before and since, many
compounds for tin/ same purpose have been hawked about,
found a few victims and passed away. We have analyzed
and exposed several of them. If they were any good,
they would he in universal use now. Do not spend good
money for them and he made ridiculous without some-
thing better than a salesman's claims or a lot of ques-
tionable testimonials to fall hack upon when the inevi-
table failure comes.
The German term Gleichstrom (gleich = even, same;
Strum = stream, current) used by German electricians
for •■continuous current" applies naturally to the contin-
uous or unidirectional flow of the steam in the central-
exhaust engine, reinvented and made a success by Profes-
sor Stumpf; and in German this is known as the gleich-
strom engine. The English equivalent, unidirectional-
How, is cumbersome ami soon became contracted to "uni-
flow." When the English translation of Profi
Stumpf's book upon the engine appeared it bore the title
'"The Una-flow Engine." Curious as to the reason for
this variation, we wrote to Professor Stumpf and to the
translator.
Professor Stumpf says : '"After considerable correspond-
ence between -Mr. Alexander and myself we decided upon
the name "Una-How.' This is a little in line with, for
instance, contra-flow condenser, and should he better than
TTni-flow.' I prefer to use the hyphen, hut this is a
matter of taste. Uni-directional-flow engine was our first
name, but we found it to be too long. Nobody would say
contra-directional-flow condenser. Therefore we dropped
this name and replaced it by 'Una-flow.'"
Mr. Peter S. TI. Alexander, the translator of the book,
says in reply: '"The full term which was used by Profes-
Stumpf and myself was originally uni-directional-
flow. When the hook was fully prepared for the press
in England, the English licensees, Messrs. Musgrave, had
already issued a circular in which they hail described it
as the 'Una-flow.' In view of this, after some little dis-
i ussion, it was decided, in deference to the new christen-
ing of Messrs. Musgrave, that the title of the hook should
he The Una-How Engine.' If a short title is to lie pre-
ferred to the lull title of uni-directional-flow, I should
say that TJniflow' in one word would he the best, from
the point of view of everyday language. I am exceed-
ingly sorry that there i- not a more subtle or logical rea-
son for calling the engine by the name 'Una-flow.'"
We quite agree with the translator. The English pre-
fix for one i- imi. not una. The prefix for counter or
against is contra, but it is just as logical to signify the
unidirectional flow of the steam in the central-ported
202
POWEE
Vol. 41, No. G
engine by "Una-flow," " in an attempted analogy with
contra-flow. as it would be to speak of the eontri-flow
condenser, in a forced attempt to be consistent with the
other prefix.
We apprehend that Professor Stnmpf knows more
about inventing and designing the engine than he does
about coining an English name for it. and are afraid that
we cannot follow his lead in this respect, although we
were inclined to adopt the spelling proposed by the man
who is responsible for the success of the engine it-ell'.
F©2*ffimualla.s foir B^sstapedl Heads
At a recent hearing of the Massachusetts Board of
Boiler Rules, it was shown that a number of the changes
proposed by the board and which were considered at
this hearing, were not intended as they were written.
An engineer of national prominence who was present
suggested that it would be well for the board to employ
an engineering editor to draft such changes or addi-
tions to the rules as might be desired, so that the in-
tent of the board would be expressed by the rules as
written. The Air Tank regulation-, just i-<ued by the
Board of Boiler Rules, is another evidence that the ad-
vice of this engineer was good. It is difficult to express
just what is intended unless one is a master of the
English language, and especially is this so when techni-
cal subjects are treated.
In the Air Tank regulations that were adopted under
date of December Hi. 1913, the rules were intended to
lie very specific as regards the calculation of the strength
of bumped heads, and were drawn up as follows:
BUMPED HEADS
11. The minimum thickness of a convex head, convex to
pressure, shall be determined by the following formula:
R X F.S. X P
or forged welded shells shall be
SI B I'
T.S.
The minimum thickness of a concave head, concave to
pressure, shall be determined by the following formula:
R X F.S. X P
0.6 (T.S.)
R = One-half the radius to which the head is bumped:
F.S. = 5 = factor of safety;
P = Working pressure, in pounds per square inch, for
which the tank is designed;
T.S. — Tensile strength, in pounds per square inch,
stamped on the head by the manufacturer;
t = Thickness of head in inches.
It was unfortunate that a convexed head was referred
to as one convexed to pressure, because this was con-
trary to the generally accepted idea on the subject; but
this would not have been an insurmountable difficulty if
it had not happened that the formulas were somehow
reversed as applied to the two forms of heads, result-
ing in a higher pressure being allowed on a head which
was convexed to pressure than on one concaved to pres-
sure, as will be seen by noting the formulas given.
Sunn after the publication of this set of rules, it was
found that they contained a number of errors and the
rules were never rigidly enforced: but the present issue
was prepared after a new act of the legislature, and it
was anticipated that the previous errors would be cor-
rected. The present Air Tank rules were approved by
the Board on August 12. 1914, and the subject of bumped
heads was treated as follows :
BUMPED HEADS
Convex Head, Curved Outward from the Shell
12. The minimum thickness of a convex head for riveted
except that the least thickness shall be % in. on tanks 20 in.
in diameter or larger, and ft in. on tanks of less than 20 in.
diameter.
The minimum thickness of a convex head for seamless
cylinders shall be
5 RP
S
except that the least thickness shall be hi in.
Concave Head, Curved Inward to the Shell
The minimum thickness of a concave head shall bfc
t, = 1.67 t
where
t = Thickness, in inches, of a convex head;
P zz Working pressure, in pounds per square inch, for
which the tank is designed;
R = Radius, in inches = % the inside diameter of the
outside course of the shell;
S = Tensile strength of the shell plates, in pounds per
square inch;
ti = Thickness of a concave head, in inches.
Convex and concave heads shall be dished to a radius equal
to or less than the diameter of the shell, and shall be true
portions of spheres.
The description of a convex head defines what is in-
tended and the formula given is correct as far as the
evident intent to increase the safety factor on such heads
is concerned: but in calculating the strength of a con-
vex head there is no occasion to involve the tensile
strength of the material of the shell plates of the vessel
to which it is attached. That the Board of Boiler Rules
believed that there wa?. some connection between these
two or that it has made the mistake of improperly ex-
pressing itself, is evident from the definition of S.
It will be seen, too, that an error has been made in
the definition of R. If R had been stated as equal to
one-half the radius in inches or. more correctly, as
ecpial to one-half the radius to which the head was
bumped, in inches, without any further additions, the
formula would have been correct as far as the calcula-
tion of the strength of a bumped head was concerned.
However, allowing that this error is a possible mistake
of the printer, the matter is still not cleared up with
the added information as given in the rule, for it will
be noted that the sentence immediately below the defini-
tions of the letters used in the formulas does not coin-
cide with the definition of R. The sentence referred
to provides for any radius for a bumped head which does
not exceed the diameter of the shell to which the head
is attached, while the definition of R would preclude the
use of any radius which would not equal the radius of
the shell to which the head was attached. It will be
seen that if the rule must be literally followed as writ-
ten, only a hemispherical head will be acceptable, and
the value of / as found by the formula, will be twice as
great as was really intended.
As stated in the beginning, it is difficult to write
rules so that they will express just what is intended, but
the employment of an experienced editor to review the
iules before their publication would have avoided the
errors here pointed out and would have been a real econ-
omy to the State of .Massachusetts.
In every plant ami factory some sort of an emergency
first-aid-to-the-injured kit should be provided. A modest
and yet complete one is that described on page 185,
adopted as standard by the Conference Board of Safety
and Sanitation. A- this outfit is sold without profit, we
are free to recommend it most heartily.
February 9, 11)15
iiiiiiiiiiinmMiiwiiiiiiiiiiiiiiiiiramiiiiiiiiiiiiliiiiiiiiiliiiiiiliiilii
P 0 W B R
lllimiiira iiiii i minimi mumi i i imimiim
20.3
'reside
In the issue of Jan. 5 I note in the article by Norman
G. Meade, "Electromagnets for Alternating-Current
Circuits," in the calculation of the magnet to work on
25 cycles, that the line voltage is taken at 4-10 volts.
In figuring the formula for turns (T) the value 1468
turns is the number required for the entire core, or
the 440 volts, and not for one coil, as stated. The com-
putations then should be as follows:
Turns per spool = — =— = 734
The ampere-turns as stated in the article
per spool. Therefore, the amperes would b
2000 circ.mils per ampere this
arc 3150
3150
73T
4.3. At 2000 circ.mils per ampere this figures 8G00
circ.mils. The nearest wire to this size is No. 11 B. &
S., which has an area of 8234 circ.mils.
From the table given in the article, No. 11 wire has
9.7 turns per inch and, allowing 8y» in. for the length
734
of the spool, «:ives 82.5 turns per layer : -^— is approxi-
mately 9 layers. Assuming that the layers and the
insulation between them measure 1.5 in., the length of
a mean turn will be 18 in. and
734 * 18 = 1100./-/. per spool
or 2200 ft. as the total length.
No. 11 wire has a resistance of 1.25 ohms per 1000 ft.,
or for the coil of 2200 ft. the resistance would be 2.2 X
1.25 = 2.75 ohms. Then the PR loss equals 4.3 X 4.3
X 2.75 = 50.9 watts. The hysteresis and eddy current
losses will not change and the total loss in watts will be
50.9 + 41.4 + 10 = 102.3 watts.
W. O. Jacobi.
Omaha, Neb.
PecuaMstfP €2rSi§°I£m\§|iiime Accadleinift
After studying over the account of the gas-engine ac-
cident as reported in the Dec. 29 issue, page 935, I can-
not see how the engine could have been wrecked in any
other way than by preignition or a continued too early
ignition, which ran readily develop from the use of a hoi
tube. The jacket water becoming very hot and heat
radiating up around the tube guard, the flame around
the tube, being better guarded, would increase in tem-
perature. This would heat the tube to a whiter heat.
Which would ignite the gas at a lower compression; also,
the cylinder being hot, the gas would reach a higher tem-
perature in an earlier stage of the compression. Contin-
ued early ignition would put an unusual strain upon
the housing or bedplate, and it may have been gradually
fractured until one very early preignition caused it to
give away.
The conditions do not indicate that the break was
caused by water. In the firsl place, the clearance of a gas
engine is nearly 20 per cent., or one-fifth the volume of
the cylinder. Using illuminating gas, it is probable that
the mixture was about one to eight and not lower than
one to six ; therefore, the gas volume of any charge would
be less than the volume of the clearance. Consequently,
the gas opening to the cylinder would probably not pass
at any one stroke a larger volume of water than that of
the gas, so that it would be impossible for enough water
to pass into the cylinder in one stroke to more than III
the clearance. Moreover, if there had been enough water
in the gas line to fill the opening at any one time, the
gas flow previously would have been so reduced that the
engine would have stopped or operated irregularly. Again,
if small quantities of water had been coming over,
before enough water had accumulated to interfere
with the piston the cooling effect and moisture would
have "killed'' the hot tube, so that the engine would
have continued to miss fire and stop.
The resulting condition of the engine would indicate
an explosive break rather than a water break. In the
latter event the strain would not have reached the break-
ing point until the piston was nearly in the center,
in which case the breaking strain would have been in al-
most a straight line and the engine would not have buckled
upward very much. With preignition, the break might
have resulted while the piston was two-thirds or three-
quarters of the way to the head center, which would leave
the crank at a low angle and the strain upward. This
would have the tendency to throw the shaft end forward
and the cylinder upward, and the still expanding gas of
the explosion would blow the piston clear out of the cyl-
inder and upward, where it afterward fell back on top of
the cylinder. II' the force of the explosion had been a
little greater, no doubt the piston would have been found
lying on the floor in front of the engine.
L. M. Johnson.
Emsworth, Penn.
A personal inspection of this engine might disclose some
peculiar reason for this accident, but if I understand
the nature of the accident, one does not have to look far
for the cause. It is stated that the bedplate cracked square
across, and if that means a crack extending roughly in
a vertical direction from a point on the frame just back
of the main bearings to the bottom of the frame, the
cause would seem to have been faulty design. The
forces acting arc exerted in a line coincident with or par-
allel to the engine axis, and ye+, in this type of engine
the metal through which the total force of each explosion
reacts (the frame) is placed some distance below this
axial line. The resulting action may be compared to the
process of breaking a chicken's wishbone by pulling on
the ends. The frame must stand a much greater str?ss
than if the metal were placed symmetrically about the
center line, and many builders do not seem to appreciate
this fact sufficiently to induce them to put enough metal
in the frame.
204
P 0 W E B
Vol. 41, JNo. b
A better method is to design the frame so thai tl i
action is taken up by metal distributed about the line of
action (the forces transmitted through the piston rod and
connecting-rod) : builders of large gas engines would not
dare build them with any other type of frame.
Every explosion, in the type of engine illustrated, is a
force tending to open up the frame in exactly the place
and manner in which it evidently let go, and the intermit-
tent application of such a force is very apt to have the ob-
served effect in time.
The writer has scon a number of accidents of this very
kind in this type. The peculiar circumstance was the
position of the piston after the accident and the fact flirt
the frame settled hack into place. The rear end of the
frame, together with the cylinder, usually makes a rapid
rearward journey until stopped by something solid.
L. I'.. Lent.
Brewster, N. Y.
The break would seem to have been caused by a pre-
mature ignition. This is a common occurrence with hot-
tube ignition, causing beds to break unless made extra
heavy. It was only a short time ago that the writer saw
a new 50-hp. engine bed break from this very cause.
ii. Strom.
Titusville. Penn.
The accident was probably caused by water in the
cylinder or preignition, as stated. Personally. I favor the
preignition theory, as the hot tube is quite liable to vary
the time of ignition — more so than the mechanically timed
electrical system; or the charge may have preignited lie-
cause of incandescent carbon in the cylinders, overheating,
etc. It doesn't seem that enough water could have been
drawn into the cylinders from the gas line to have caused
any damage, as only a small part of the charge i- gas
Forrest E. Carpenter.
Salmon Falls. X. II.
SS
Cotnasiffieiovft ©eh A.iniasia(n>ini£a
IM gv ggir Si-mas
I note in your Dee. •.'!> issue, page 930, two articles on
ammonia-compressor diagrams. The first, by Charles
Mugler, does not give the clearance of the compressor
either in per cent, of displacement or in per cent, of the
crank-end and head-end volumes. This information
should hi' given, as otherwise it is impossible to judge
whether or not the compression obtained is that for a
machine in good condition. The compression curves just
after the suction valves have closed seem to show an un-
usual increase in pressure, which may be due to piston
leakage, but without knowing the clearance of the com-
pressor it is impossible to draw correct adiabatic curves
on these diagrams. If the diagrams are drawn to scale,
the pressure at the end of suction for both ends of the
compressor is about 19 lb., whereas for a compressor with
properly designed suction valves the pressure at this
point should lie higher than the pressure recorded on the
suction gage. Tin- i- due to the inertia of the vapor in
the suction pipe which keeps the valves open even after
the piston has reached the end of the stroke. The exces-
sively high discharge pressure, even after the discharge
valves are open, indicates that either the ammonia con-
denser to which this machine is connected is too small,
or the discharge pipe too small in diameter for its length.
The fact that there is a hook at the end of the expan-
sion line of the right-hand diagram, and not one on the
left-hand one. -how- that the suction valve on the right-
hand end of the machine either stick- or is provided with
a stronger spring than the one on the left-hand end.
In regard to I). II. Crawford".- discussion of the am-
monia-compressor diagram, I do not agree with his ex-
planation of the broken-line discharge curve BCDE |
29). Whenever an ammonia-compressor ciagram is tak-
en with a rather weak indicator spring, these -zigzag
lines are frequently noticed and are generally caused by
the momentum acquired by the indicator piston from the
rapid rise of pressure in the compressor near the end of
the compression stroke, and seldom by the chattering of
the discharge valve.
Fred Ophdls-.
New York City.
<»
Msnr&dl^ Sft.m§|iEag|
The illustration show- a handy staging for use when
working on shafting, pulleys, the fronts of boilers, etc
One Application ok the Staging
Any handy man can make and attach it to a couple of
ladders without difficulty.
Thomas Sheehan.
YVilliamstown. Ma>s.
; ;
PeedUWgvfteK5 Hea6®pi
In the issue of Oct. 13, page 540, 1.. B. Carl commented
on the relative merits of open and closed feed-water heat-
ers.
The writer, having had considerable experience with
feed-water heaters, begs to call attention to one statement
made therein as follows: "A closed heater is not suitable.
where the exhaust steam is intermittent, because the sud-
den changes in temperature will loosen the tubes." This
is true of the straight-tube type only, and where proper
provision is not made to allow for the unequal expansion
of the shell and tubes.
I believe the best heater for resisting the effect of sud-
den temperature change- is the coil type when properly
designed and built, as it will operate for any number of
year- without any of the joints becoming loosened, due
February 9, 1915
IM> W E If
205
to expansion and contraction. All the joints should be whence it is obtained from the faucet Q. The residue
brazed, as these arc best able to stand the boiler pressure from the distilled water is run oil through the pipe •/.
and sudden temperature changes. controlled by the valve /'.
W. ('. Beekley. 10. b. IIayks.
Hartford, Conn. Eouston, Tex.
Tlhe BJagphft Emigaiaeeip OlRF Dva&y
The editorial in Power, Oct. 13, 1914, entitled "The
Night Engineer Off Duty"' was certainly appreciated by
me, for I spent three years on the night turn.
It calls to my mind a little incident of Yankee in-
genuity. Several years ago, while erecting an ice plant in
the South, I visited the factory one night to see how the
machine was running, for we hail just started and I was on
the lookout for trouble. I found the old man who had the
night turn sitting in a chair, holding a 12-in. monkey-
wrench in his hand. As he did not seem to be using it, I
asked why he was holding it. and this was the answer: It
had been too hot that day to sleep much and he was sleepy.
If he went to sleep he would loosen his hold on the wrench,
it would fall to the floor and awaken him. He would then
gel up and take a look around the engine room, sit down
and pick up his monkey-wrench alarm and take another
rest.
Perry Losh.
Muncie, Ind.
FrssiC^acsiE Use fosr Gavs~lEifi\§|ainie
lExdhsvaastl
The sketch shows a water-distilling apparatus operated
by the waste heat in the exhaust gases from an internal-
combustion engine. It is adapted to power houses,
factories anil boats where pure water for drinking and
other purposes is desired.
I. a re
aimi^ ILa^phxfts
all T
1 1
I
i
N M
=
™
'M
)
H
Section' through Distilling Apparatus
The apparatus consists of a cast-iron drum C divided
into two separate compartments N and M, a heat-
insulating cover /.'. a cooling tank 1) divided into two
separate compartments / and L, and a condensing coil K.
The exhaust gas from the engine enters the drum C
through the pipe //, fills the chamber N, and passes out
the pipe B. Water enters the compartment M, through
the pipe S, regulated by the valve G, is vaporized from
the heat in compartment A, passes through the pipe A
into the condensing coil K, surrounded by cold water in
the tank /. is condensed, and flows into the reservoir L,
The sketch shows the connections of a three-wire gener-
ator. For simplicity it is shown with two poles, although
four or more are usual. The armature generates 220
volts, obtainable from the outside wires connected to the
brushes. Two slip-rings mounted upon the armature
shaft are connected at dia-
metrically opposite points ol
the armature winding, and
from brushes bearing upon
the slip- rings conductors are
carried to the ends of an
iron-cored reactance coil, to
the center of which is con-
nected the middle or neutral
wire of the three-wire sys-
tem. A resistance might be
used for this purpose, but as
the device is continuously
subjected to alternating
e.m.f., reactance is more ef-
fective in limiting its value.
The net result of the ar-
rangement is that 220-volt
motors may be operated from
the outside wires and 110-
volt lamps from either outside wire and the neutral. The
reactance carries direct current only when the two sides
of the service are unbalanced. The unbalancing direct
current entering the reactance at the center divides, half
flowing around the core in one direction and half in the
other; its magnetizing effect is. therefore, practically
nothing.
An inspector was called to find out why the lamps fed
by such a unit flickered. Inspection of the taps from
the rings to the winding disclosed that they were not
tapped to the winding at equidistant points. Changing
the taps to points of symmetry stopped all flickering.
J. A. Hop.ton.
Schenectady, N. Y.
Connections of Three-
Wiiiio Generator
^essuaire
Vsvlwes
A drain should be connected just above the back-pres-
sure valve. If connected at a higher point, the vapor
may condense and create a static head above the valve,
which will prevent it opening under ordinary pres-
sure.
The vent pipe may be dispensed with by drilling small
holes in the seat of the back-pressure valve. The escape
through these openings will be sufficient to relieve air-
binding in the heater and drain back any condensation
in the exhaust or vapor pipe.
T. W. Reynolds.
New York City.
206
POWER
Vol. 41, No. G
Usasaf© BSowoiff Papanag*
A couple nt' years ago I was a fireman and assistant in
a small cold-storage plant. There were three boilers,
but we only fired one, which was sufficient to carry the
load. The night fireman asked me to do all the blowing
down on No. 2 boiler, as its blowoff valve was situated so
far back in a dark corner that if anything should happen
he wouldn't have as good a chance to get out in the dark
as 1 would in daylight.
I did so until one day the boiler inspector told us to
disconnect No. 2 blowoff, as he did not believe the pipe
between the valve and boiler was made up very tight.
You may imagine our surprise to see it drop out of the
elbow near the boiler after giving it only a half turn
when unscrewing it. The pipe had only two threads
caught, and they were nearly eaten out. The steam
fitters had cut it too short, but used it anyway to save
cutting another. I learned afterward that the night
fireman knew of this, hence his distaste for blowing down
this boiler.
C. Kxowlaxd.
Louisville, Ky.
m
Wlh^ tfiae Gage Haimdl Valbsrattedl
The cause of the gage hand vibrating, as referred to
by A. E. Aldrich in the Jan. 5 issue, was the intermittent
steam flow caused by the cutoff of the reciprocating en-
gines. During the daily periods referred to there was
some change in conditions, as an additional unit in
service or vice versa. The oiler in turning the valve sim-
ply closed it a little more than usual, which should have
been done before.
Jonx F. Hubst.
Louisville. Ky.
m
Cosft of ©peiraftaimfl Vsvcoaunsia Aslh=>
Maimdlllainigi Sysftenms
The discussions of vacuum ash-removal systems in the
July 7, Sept. 8 and 15, and Oct. 20 is>ues, following the
article describing the Girtanner-Daviess system in the
April 7 number, have been both interesting and fair-
minded and have brought out a number of instructive
features. The point is to be emphasized, however, that
the instances of expensive installation and heavy repairs
cited do not refer to the system described in the original
article, as the discussions refer to motor and blower cost-
instead of a steam jet. Even Mr. Sandstrom's estimate
of charges in the July 7 number is based on his experience
with a blower system.
The absolute cost per ton of ashes removed has no com-
parative value as a criterion. The most economical sys-
tem, from wheelbarrow up, for an unfavorable location,
may still leave costs high. Furthermore, the final re-
ceiving tank may be ignored for purely comparative costs
of different systems (unless special expense is here ne-
cessitated by the peculiarities of a system) since such tank
should rather be imposed equally on each system by the
final disposition made of the ashes. This system will
discharge directly onto a dump or into any receptacle.
The maximum repair bill for a year on steam-jet instal-
lations ranging in price, for pipe line only, from a few
hundred up to $1 100 has been a fraction over $112— about
one-seventeenth of the 40 per cent, experience of Mr.
Sandstrom. Again, one man is well able to handle the
seven tons per hour for which Mr. Sandstrom wishes to
hire two, and this cuts his labor cost in half. In moder-
ate-sized plants the system may be operated by the fire-
man along with his other duties, and in larger plants the
attendance is a minimum. The initial cost is low, so
that interest on the investment does not eat up economies
secured. The steam used in the jet amounts to 5.29c. per
ton (see Apr. 7 Powee).
Gietaxxeu-Daviicss.
St. Louis, Mo.
Fas&dlaini§| ftlh© Besft Cosj.I1
The letter, "•Finding the Value of Coal," by William
A. Dunkley, in the Jan. 5 issue, interested me. One
point of importance was not stated in the article, and
that is, whether the coals furnished by the roads A and
I! were of sensibly the same character. If the fuel tests
of the two coals showed wide variations in ash, volatile,
sulphur and heat, trouble in the fire-room could have
been predicted in advance of the change from one coal
to the other, provided no change was to be made in the
method of handling the fires.
The following quotation from a paper read by me
before the New Jersey Clay Workers" Association at the
winter meeting at New Brunswick, N. J., Dec. 29, 1914,
should serve to make clearer the fundamentals involved
in the problem which confronted Mr. Dunkley:
. . . The combustion of coal in a furnace is a complex
process, and the different combinations of equipment and
methods of handling the equipment are almost infinite. And
there are numberless kinds of coal. That statement is made
advisedly. Considering alone the inherent characteristics,
that is, the sulphur, volatile, ash, the fusing point of the ash,
and the heating value of the coal, you can, within certain
limits, find coals with all of these factors in any proportion
you may desire. Here are five variables and each one has a
considerable range of variation. In addition there is the vari-
ation in the physical condition of coal; that is, whether it
comes in the form of dust — the slack — or screened to a certain
size, or what is called the "run of mine." Then there is the
question of coking or noncoking.
There are few, if any, industrial uses for coal which re-
quire definite adjustment of every one of these variables.
Certain definite limits of part of the characteristics already
mentioned are especially required in any particular case,
without, however, limiting the remaining factors. The first
point is, therefore, that you must know what factors are
material in the selection of your coal before you can change
to a new coal with any reasonable expectation of getting
better results, or the same results at less cost.
The chief use of coal is to produce heat by its combustion.
In any particular process to accomplish the best results a
certain amount of heat must be released in a certain length
of time. Let us assume for the present that this is the whole
problem, disregarding all other questions, such as the avoid-
ance of smoke, fumes injurious to the product, etc. That
limits us to three variables — the heating value of the fuel per
pound, the amount of fuel burning at one time, and the
amount of fuel burned per hour. The first is determined by
the selection of the fuel, the second by the area of the
grates, and the third by the thickness of the fire and the
amount of air supplied to it. It is obvious that if we change
any one of the three, we will directly affect the result, which
is a given amount of heat liberated in a given time. This
may seem rather elemental, but the point I wish to bring out
is that frequently the user tries to change one of these
factors (usually the coal) without making corresponding
readjustments in one or both the remaining conditions, with
the result that lie concludes there is only one kind of coal
he can burn satisfactorily. Frequently, a minor change in
equipment or methods of firing will make possible the use
of another coal at considerably less expense
Carlton YV. Hubbard.
Brooklyn, N. Y.
February 9. 1915
POW E T!
207
Ttpo-aalb]!© wnftlh Oil Sepsia.&ftos0
Can any Power reader suggest a remedy for trouble
with an oil separator? Since taking over tny present
plant I have had considerable annoyance from grease
passing over with the steam into the heating system from
the separator of a small engine Located in the cellar,
where the connections are arranged as in the accompany-
ing sketch.
A new separator and various kinds and sizes of seals
Heating System
BP Valve
Oil
Separator
_^_
To Atmosphere
Arrangement of Oil Separator Which Gives
Trouble
have been tried without effecting a remedy. We carry
8 in. of vacuum and the grease is drawn through the
separator. Several so called experts have seen the con-
ditions and each has advised different sizes, loops, etc.,
but upon trial none of them has proved satisfactory.
II. 6. Goodwin.
Lachine, Que.
&
My article on industrial education for operating engi-
neers, which was published in Power, July 28, 191 1. was
intended to draw out discussion. I was glad, therefore,
to hear from William E. Dixon, in the Nov. 10 issue, even
though he does not agree with me and thinks the sort of
trade school 1 was connected with so long is a "pure
and arrant fake."
This problem of industrial education is far from being
solved; those who have worked the hardest and the Longesl
realize that better than those who are on the outside look-
ing in. Many mistakes have been made, and many more
will be made. The fact remains, however, that the in-
dustries are today so organized that learning any trade
under the old conditions is practically impossible. The
few large shops which realize this fact arc providing
schools within their own walls. These have all the prob-
lems to meet which are met by the public trade school,
if politics can be kept out of the latter, and that is
possible.
There is no need to forget the cultural, civic or busi-
ness side of a boy's education because he is in a trade
school. I do not know what schools Mr. Dixon has sen.
but his name is not on the visitors' hook at the Worcester
Trade School, so I am sure be has not been shown that
school l>\ anyone in authority able to explain what is
really done there. While sonic things are far from per-
fect, they are not those to which he alludes. These schools
should, and most of the state-aided schools do, gi\c at
least one-third of the pupils' time to regular high-school
studies. Their hours are much longer, and consequently
this time is almost equal to the total time which the regu-
lar high schools give.
Some interested in industrial education do believe
a trade school should teach trades solely. We have never
felt that we could conscientiously send out a graduate
unequipped, so far as his mentality allows, for the battle
of life.
It is not easy to find the right teachers. We had one
for a short time who had a first-class license. He bad
handled some big plants and came well recommended He
knew nothing except by rule of thumb, could not tell
that to anyone else, and would not be helped by those who
did know how to teach.
A man who knows what he is trying to teach, who has
not forgotten that he was a boy, and who has a cheerful
disposition has a fair chance of learning to teach by ex-
perience alone. Certain tricks of the trade of teaching
he may learn from more experienced men. These relate
almost entirely to discipine. The largest job is how to
impart what one knows to students so that it makes an
impression and is within their comprehension. When an
engineer has clone a certain thing for years he easily loses
sight of why he does it. It is enough to tell a helper
to do a thing, and he does it until it becomes a habit.
That is not education. A man has not learned how to do
a thing until he understands the reasons for doing it.
Mr. Dixon should prove his statement that "the schools
cannot even hope to get an equipment that would serve for
much more than a toy." There is no reason why a school's
money should not go as far as that of any corporation.
In fact, experience shows that it can be made to go farther
than any other city money. Builders of the best machin-
ery have made concessions that, taken alone, would lit oul
a school in far from toy fashion. The cost per pupil for
adequate equipment is less than that for equally good
machine-shop equipment.
Mr. Dixon hints that desirable boys will not go to
school to learn to be engineers. That depends on what
you will take. If you start a school with riffraff it will
be hard to get decent boys into it. A school cannot afford
n be snobbish, but it can make a manly attitude toward
the work a condition of membership. There are plenty
such boys, but they will not go where the other kind are
tolerated in any considerable numbers.
"It is bad practice to try to teach a person an idea
until that person lias a desire to know it," says Mr. Dixon.
If my father had humored me when I was a small boy, I
would not have begun to get ideas yet. A boy should be
taught while he is young and receptive. The instructor
is of little use who cannot make steam engineering at-
tractive to a boy. A boy must lie brought to the point
where he knows that it is up to him to learn before he
will learn many things.
The crying ill of all our educational systems is that
the pupils do not wake up to their needs until it is too
late. They are so delicately handled now that they think
they know much better what is good for them than their
parents The adequate substitute for the stiff stick in the
208
POWER
Vol. 41, Xo. 6
hands of a raw-boned Yankee teacher as an idea awakener
has never been found. If this notion that a boy should not
be taught anything until he has discovered for himself
that he needs to know it were ever followed except on
paper, our schools would be picnics and education would
be below zero.
E. H. Fish.
Worcester. Mass.
m
GoE&ttmcftos3 Closed asadl ©pesm@dl
The diagram shows the connections of a starting-bos
used in conjunction with a contactor which ruptures
the arc, thereby saving the rheostat contacts when the
starter is thrown to the off position. It also acts as a
no-voltage release to open the motor circuit should the line
become dead, with no one in attendance. Upon simul-
Fteld
CjUaft/re U"~»firnlti
Stabting Device
taneously twisting handle li and moving it in a clockwise
direction, an auxiliary contact arm mounted on 7i, and
brought down by the twisting motion, touches the button
b, to which is connected one end of the operating coil /
of contactor c. This closes the local break through the
contactor and the motor takes current. If the handle is
kept twisted and in contact with d, as it is advanced, coil /
will remain energized throughout the travel of the handle.
At the end of its travel the handle engages a spring clip
on post e and the twisting stress may be released, because
coil / is then energized independently of the auxiliary
contact.
It will be noted that at the start, when the auxiliary
contact rests upon button b, the full line voltage is applied
to the coil /. but after the contact reaches segment d. re-
sistance r is cut into series with coil /. This is a feature of
safety as well as of economy, because less current
quired to hold the contactoi closed than is required to
close it: and if the voltage should leave the line, thereby
causing the contactor to open, it would remain open un-
til someone returned the starter to the '"off" position and
repeated the starting cycle, because with r in series with
/, the current would be insufficient to close the contactor.
One of these outfits in a lumber camp, where it was
exposed to the weather, was complained of because in go-
ing from the "off" to the "on" position the contaetoT
would open immediately after closing. Insulation strip i
is used simply to preserve a smooth surface for the auxil-
iary contact in its travel from button b to the segment d
Investigation showed the trouble to be due to this insula-
ting strip having absorbed rain and so swelled as to raise
the auxiliary contact finger out of contact with b before
it had made contact with d. This, of course, demagne-
tized coil / and permitted the contactor to open. The
trouble was remedied by sandpapering the surface of i
below the surfaces of button b and of segment d. It i-
interesting to note that an open-circuit in resistance r
may cause the same failure.
J. A. HORTON.
Schenectady, X. Y.
ILoss h>w ttlh© UJs© ©f SlacM C®siE
Here is an account of two boiler tests that may inter-
est some engineer operating the Hawley down-draft fur-
nace. Plants with these furnaces have their troubles when
using slack coal. When we have mixed coal we can show
good results, but with slack we cannot keep it on the top
grate. The result is that we cannot carry the load with
the same number of boilers on the line. With mixed
coal I ran a test on Dec. 2, 1914, on a 150-hp. Coatsville
fire-tube boiler with a Hawley down-draft furnace. The
first test was very good, the evaporation from and at 212
deg. F. per pound of dry combustible being 11.66 lb., the
horsepower-outjmt 287, an over-rate of 91 per cent., and
the efficiency of the boiler and furnace was 69 per cent. It
cost 1 ().'.' 1 cents to evaporate 1000 lb. of water.
The followiiiir day I ran a test on the same boiler, with
the same fireman, and tried to get as near to the first
test as was possible, but using coal containing very few
lumps. This second test showed a decided falling off.
We evaporated 10.63 lb. of water per pound of com-
bustible and developed 249 hp., an over-rate of 66 per
cent, in place of 91 per cent. It cost 11.25 cents per
thousand pounds of water in place of 10.21 cents and the
efficiency was only 64 per cent. The loss in twenty-four
hours on nine boilers amounted to $21.33 with slack coal.
Harry Biehl.
Philadelphia. Penn.
Cosiminatiatss.tlotP SlhotPtt^Ciirciiflattedl
An inspector was called to find out why the armature
of a motor was heating and "shooting like a gun.'" He
ascertained that the commutator had just been slotted
in a lathe. The side mica was very thin and the lathe
tool used was too thick; the result being that the tool
curled shavings from the bars and at the end of the stroke
ib of the shaving was jammed into the mica and
across an adjacent bar. The burrs had been picked out
where they could be seen, but some were too deeply em-
bedded.
A- -non a- the motor was started, all the coils that were
short-circuited by bridged bars were heated by the local
short-circuit current- which, as the speed became greater.
became sufficiently heavy to burn out the short-circuits
that had not been picked out. The noise like the report
of a gun was due to the extinction of the arc by the mag-
netic field. The motor was then run up to full speed
and without any further demonstration. The arc-extin-
guishing properties of the magnetic field explain why
armatures that burn out in service are not as badly dam-
aged as might be expected.
J. A. Hortox.
Schenectady, X. Y.
February 9, 1915
POWER
209
iliiiiiiiiiiiiiiiiiiiniiiii iiiiiiiiimiiiiiniiiiii i nun n i iiiiiiiiiiiiiiiiiiiii iiiiiiiii mi iiiiiiiiiiiiiiiiiiiiiiiini u nun niiniii in iniiiiiii in m am in it iiiinnni J
Salt in Fireclay — What is the purpose of adding; salt to
fireclay used in setting the firebrick of boiler furnaces?
M. G. W.
The addition of about a pint of salt to a bucketful of or-
dinary fireclay causes partial vitrification of the fireclay
whin it becomes heated, and increases its adhesiveness to
the firebrick.
Removing Stains from Gage-Glasses — Hot
moved from boiler water gage-glasses?
can stains be
S. M. E.
Most stains formed on boiler gage-glasses can be re-
moved with a swab of clean waste moistened with a weak
solution of muriatic acid. In the cleaning process care should
be taken, however, not to employ wire or other material
likely to scratch the glass and thereby weaken it.
Coefficients of Expansion — What are the relative rates of
expansion of aluminum, brass and cast iron for the same in-
crease in their temperature?
C. R. H.
The coefficients of expansion or proportionate increase of
length for each degree increase of temperature of the metals
named are: Aluminum, 0.00001234; brass, 0.00001; and cast
iron, 0.00000556.
Bedding- Underground Pipes in Sand or Gravel — What ben-
efit is to be derived from bedding underground steam or water
pipes in sand or gravel?
J. N. R.
The principal advantages obtained are more perfect grad-
ing and better subdrainage. In case of steam pipes, whether
or not they are laid in conduits or coverings of any kind,
subdrainage is important in reducing the convection of heat
from the pipes to the surrounding earth, and in case of water
pipes complete bedding in sand or gravel affords better pro-
tection against frost.
Drainage of Boiler Steam Main and Arrangement of Stop
Valve — How should a main steam pipe slope and boiler stop
valve be placed between a boiler and engine?
D. J.
The slope of the piping and arrangement of the stop valve
should be such that all condensation between the valve and
the boiler will drain back into the boiler, and the slope of
the piping beyond the valve should be such that the water
will drain from the boiler toward the engine. Stop valves
should be so arranged that pressure from the boiler will tend
to raise the valve from its seat, and they should be given
such a position that there will be no accumulation of con-
densate above the valve when it is closed.
fare of Standing Boiler — When a boiler of a battery is
not required for some time, is it injured by standing with
water at the usual level carried for steaming?
W. B.
There will usually be more rapid corrosion of the interior
above the regular water line, and especially near the water
surface, when so standing than when steaming. When not
required for some time, the boiler is better preserved by emp-
tying it of water and drying thoroughly. If that is im-
practicable, interior corrosion can be reduced by completely
filling the boiler with water, although for most situations this
results in more rapid exterior corrosion than when the boiler
stands empty, due to condensation of the moisture of the
atmosphere.
Pressure in Discharge Pipe with Drop Leg; — Neglecting
pipe friction and inertia, what pressure would a pump have
to work against if the discharge pipe rose to a height of 150
ft. and returned with an open end at the level of the pump?
G. K.
For starting flow in the descending leg, the pressure
pumped against would increase to
150 X 0.434 = 65.1 lb. per sq.in.
As a column of water 34 ft. high would balance the pressure
of the atmosphere, then if a solid column 34 ft. or more in
height were maintained in the descending leg of the dis-
charge pipe, a vacuum would be formed in the upper end of
the ascending pipe, thus relieving it of pressure equal to that
of the atmosphere. The net head pumped against would then
be 150 — 34 or 116 ft., which would be equivalent to
116 X 0.434 = 50.34 lb. per sq.in.
Coal Required under Stated Conditions — With the temper-
ature of feed water at 200 deg. F. and a combined boiler and
furnace efficiency of 60 per cent., how many pounds of coal
of a calorific value of 1?,500 B.t.u. per lb. would be required
to evaporate 13,600 lb. of water into dry saturated steam at
130 lb. gage pressure?
T. B.
The total heat required to convert a pound of feed water
from 32 deg. F. into dry saturated steam at 130 lb. gage
or 145 lb. absolute pressure would be 1192.8 B.t.u., and as each
pound of feed water at 200 deg. F. would contain 200 — 32 or
168 B.t.u. above 32 deg. F., then to raise 13,600 lb. of water
from 200 deg. F. to dry saturated steam at 130 lb. gage pres-
sure would require
13,600 X (1192.8 — 168) = 13,937,280 B.t.u.
With a combined boiler and furnace efficiency of 60 per cent.,
from each pound of coal containing 13,500 B.t.u. there would
be realized
13,500 X 0.60 = 8100 B.t.u.
and, consequently, the evaporation of 13,600 lb. of water un-
der the conditions stated would require
13,937,280 B.t.u. H- 8100 B.t.u. — 1720 lb. of coal.
Pipe Surface Required for Heating AVater — How many
lineal feet of 2-in. iron pipe, or of brass or copper pipe of
the same size, would be required as heating surface in a
closed tank to heat S00 gal. of water per hour from 50 to ISO
deg. F. with exhaust steam at 1 lb. gage pressure?
A. M. D.
In raising the water from 50 to 180 deg. F., each pound would
receive ISO- — 50 or 130 B.t.u., and as 800 gal. of water would
weigh S00 X SJ = 6666 lb., and, neglecting losses by radiation,
the total heat to be transferred would be
6666 X 130 = 866,580 B.t.u. per hr.
As the temperature of the steam would be about 213 deg. F.
and the average temperature of the water would be
50 -f ISO
— =115 deg. F.
2
then the mean temperature difference between the steam and
the water would be
213 — 115 = 98 deg. F.
For this mean temperature difference, iron pipe would con-
dense about IS. 5 lb. of steam per square foot per hour, and the
latent heat of steam at 1 lb. gage pressure being 969.7 B.t.u.
per lb., then for each square foot of pipe surface there would
be a liberation of
18.5 X 969.7 = 17,939.45 B.t.u. per sq.ft.
so that
S66.5S0
= 48.3 sq.ft.
17,939.45
of iron-pipe surface would be required. As 1.60S lin.ft. of
2-in. pipe would be required per square foot of external
surface, the total heating surface would require
1.608 X 4S.3 - 77.7 lin.ft.
of 2-in. iron pipe. Under the same conditions brass pipe
would condense about twice as much and copper pipe about
2J times as much steam per square foot of surface, and there-
fore
of brass pipe, or
about 3S.S lin. ft.
about 33.3 lin.ft.
of copper pipe, of the same external diameter as standard 2-
iron pipe, would be required.
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR]
210
P 0 W E E
Vol. 41, No. 6
,i.i
-m\Eiini(
>tkfldl
>tuur°i
-uiWiwiiiilliuiNiir . ;::
Sft©aiffiift=3£2agpin\<e Cycles
The diagram representing the ideal performance of the
steam plant is given in Fig. 1, repeated from Fig. 3 of
the article on "Heat-Engine Cycles."' A brief review of
this Rankine cycle is as follows :
Line AB shows complete evaporation and the transfer
of the steam to the engine or turbine, without loss of
heat by radiation, loss of pressure by pipe friction or
throttling, or loss of volume by initial condensation.
Its right-hand end may also cover superheating, which, of
course, takes place at boiler pressure.
Curve BO shows adiabatic expansion, possible only in
a cylinder of some imaginary, thermally neutral sub-
stance. This expansion is carried clear down to the exhaust
pressure at 0.
Line CD represents complete expulsion of the steam
from the engine and its contraction to the liquid state
in the condenser (or atmosphere).
back as pressure and steam temperature are lowered,
curve EF falls less rapidly than would an adiabatic from
E. In shape, curve EF is here drawn as an equilateral
hyperbola, following the law
Pressure X volume = a constant, or pv = c.
Sometimes the hyperbola is called the theoretical curve
of steam expansion. The title is undeserved, for thermal
conditions within the cylinder are so complex that the
formulation of any theory of expansion is impossible.
The very prevalent use of this curve in laying out pre-
liminary or illustrative diagrams is based on two wholly
practical facts or considerations. The first is that the hy-
perbola is a fairly good working average of the expansion
curves of actual indicator diagrams; the second, that it is
an easy curve to plot.
The best collection and discussion of data as to the form
of real steam curves that have been made will be found
in the paper on "Cylinder Performance," presented to
Fig. 1. Diagram Representing Ideal
Performance of Steam Plant
0 M N V
Fig. 2. Illustrating Clear-
ance and Compression
Fig. •">. Loss Due to
Clearance
This diagram implies that the engine lias no clearance
at all. It is the form of ideal action in either piston en-
gine or turbine, but the interpretation is somewhat dirl'ei-
ent for the two types of machines. The engine will now
be considered.
Area ABCDA, Pig. 1. shows the maximum output of
work per pound of steam, within the particular limits of
pressure and temperature, and the best possible efficiency.
In the actual plant there are four ways or directions in
which this ideal performance fails of realization. These
sou pi es of Loss are :
(1) Pipe and valve losses, of heat and pressure, in-
clined in the transfer of steam to and from the cylinder.
(2) Thermal action of the cylinder walls.
(3) Incomplete expansion.
( [ ) Clearance and compression.
Of these, Nos. 2 and 3 will first be taken up, then
No. 1. and finally No. 1 ; and in the consideration of
them the evolution of the actual indicator diagram from
the ideal outline ABCDA will be shown.
The effect of initial condensation, by the cooler metal
surfaces with which the steam entering the cylinder comes
into contact, is evidenced in the shrinkage of steam vol-
ume from .1/.' to AE. And then, because the heat thus
taken from the steam at high pressure begins to come
the American Society of Mechanical Engineers by J.
Paul Clayton, in May. 1012, and reviewed in Poweu
for .June 18, 1912. The subject is too extensive for more
than a reference here. It is enough to say that when
there are conditions favoring excessive cylinder-wall ac-
tion, such as small size and low speed, with early cutoff,
the expansion curve will run much above the hyperbola.
On the other hand, with high superheat and small thermal
action, it will fall much more rapidly. But in the general
run of ordinary conditions, departures from the form
pv = c are comparatively small.
Returning to Fig. 1, it will be noticed that the as-
sumed curve EF rises steadily toward the adiabatic BC as
the steam expands. In further illustration of the same
point, curve LM is a hyperbola drawn from B. The ver-
tical distance between LM and BC at first grows larger,
then diminishes: hut when it is remembered that this
difference is a relative quantity, to be compared with the
whole pressure from base line OY up to the curves, it is
seen to increase progressively.
Now in ideal operation, or in the process reasoned out
for getting the maximum work from a pound of steam.
expansion is carried clear down to exhaust pressure.
There is very good reason why this ought not to be dene
in the real engine, and why it is more economical to -top
February 9, 1915
po w e 1;
211
at some such point as F. To get the small amount of
work represented by the triangular area to the right of
line FG would require a cylinder more than twice as large
as is needed to contain volume BG. First of all, this
would make the engine cost more, hut worse than that, it
would involve continual losses in operation. It the
cylinder is too big ami cutoff too early, the waste <hw
to thermal action by the cylinder walls becomes relatively
greater. And in driving the piston by a small mean effec-
tive pressure such as will prevail beyond FG. the loss
of work through machine friction will exceed il E
fective work done by the steam upon the piston, and
the result will be a net loss rather than a gain.
The matter of clearance and compression is taken up
in Fig. '.'. As the first step, the combined expansion
and release lines E'F'G' are transferred directly from Fig.
1. These lines represent the performance, in an engine
without clearance, of one pound of steam which enters
the cylinder, does work, and goes to the exhaust. But now
there is to he associated with this working steam a certain
proportionate amount of clearance steam. In Fig. 2,
the volume PE' of the working steam in its condition at
cutoff is moved out to IIB, leaving hack of it a space PH
The Diagram Obtained in
Practice
filled with clearance steam. Of course, this division is
imaginary, for there is no separation into distinct volumes.
The point is that, of the steam present at cutoff, a portion
IIB is going to be discharged, while the remainder PlI
will be caught and compressed.
As the whole body of steam expands along curve BG,
the clearance quantity has its increasing volume measured
out to the similar curve HK. Since these curves are taken
to be of the same form as E'F' , horizontal distances be-
tween curves HK and BG are the same as between line
OP and curve E'F'. In effect, then, the original no-
clearance diagram PE'F'G'Q is shifted over to the right of
curve UK. This distorts its shape, but does not change
its area above a horizontal line through F' or G; below
that pressure, however, there is a loss, the cause of which
can be stated in two ways. The first is, that F'G' would
be changed to a curve GR. as shown in Fig. ;i, at a con-
stant distance from curve HK; ami the vertical release
line GD cuts off the extended area GRD. The other form
of statement is, that since effective volumes of the work-
ing steam arc measured over from curve UK. and these
grow shorter below the terminal pressure at C, the lower
end of HK cuts under the effective diagram and dimin-
ishes its area.
The loss due to clearance is more fully illustrated in
Fig. ;j. At the beginning of expansion the steam in the
cylinder is partly condensed, because of wall action. At
the beginning of compression the steam left in the cyl-
inder is likely to he nearly or quite dry, perhaps even
a little superheated. Consequently, the quality of the
clearance steam is higher at E than at K, and its volume
is greater; then the compression curve runs to the right of
///v. or the clearance steam requires more work for its
compression than it gives back in expansion.
The lost ana ( 'h'/)( ' is, in effect, an addition which com-
pression makes to the work not utilized because of in-
complete expansion. This triangular figure mav be ear-
ned over to the position -IK L.I: and then we say that
while the clearance steam really follows curve UK all the
way down to exhaust pressure, its effective delivery of
work ends at the pressure of n lease. Any work of expan-
sion to the right of J 1, simply helps the outrush of steam
during release. A condensed statement regarding clear
ance losses may be made as follows:
If the whole weight of steam represented by volume
PB came from the boiler into an engine without clear
ance, it would do the work represented by area PBCDQP,
Fig. ;;.
Actually, because of clearance and compression, the
useful work really performed is only that represented
by area ABCDEFA.
But the area PAFEQP is not all loss, for a part of it is
covered by the work PHJLQP of steam which did not
come from the boiler, but was saved over from the pre-
ceding cycle. The net loss is then the shaded area
APELJHA.
This lost area is made up of three parts. In order to
separate them, the compression curve is extended as FG,
here made similar to UK. This continues up to admis-
sion pressure, the prevailing difference in quality be-
tween compression and expansion, and shows a com-
plete working cycle EGIIKE for the clearance steam.
Then the three partial losses are :
Area AFGA due to throttling of the live steam as it en-
ters and fills the clearance space.
Area EGIIKE due to cylinder-wall action, working out
through the cycle of operations of the clearance steam.
Area JKLJ, in effect, as has been explained, an addi-
tion to the incompleteness of expansion.
In regard to the proportions of this diagram, it is to
be noticed that the difference between curves EG and II K
is exaggerated, being too great relative to the quality
at cutoff shown by the ratio of AE to AB in Fig. 1.
The ideas developed in Fig. :i open the way to a more
or less definite rational determination of the best degree
of compression corresponding to a certain set of condi-
tions on the expansion side of the indicator diagram. The
indefiniteness is due in part to uncertainty as to the exact
form of the expansion and compression curves in the ac-
tual engine, and for the rest to modification of the sharp-
cornered diagram by the pipe and valve effects shown in
Fig. I. But this general idea of the several sources of
loss makes it easier to understand the results of experi-
ments made to determine the effect of compression upon
economy.
In Fig. t, the outline ABCDEFA is the same as in Figs.
2 and IS, hut its proportions are changed to something
nearer those of common indicator diagrams. It only re-
mains, then, to sketch in curves of admission and release
and a line of increased back pressure, and thus conic to the
end of the evolution of the actual indicator diagram.
Knowledge of the magnitude of these pipe and valve effects
comes wholly from experience, or from familiarity with
the performance of the various classes of engine.
212
P 0 W E E
Vol. 41, Xo. 6
PMimtt
erffir&^miy
SYNOPSIS — Description and data of test results
of the municipal refrigeration plant at Lubeck,
Germany. The poppet-eat re compressor engines
use highly superheated steam and son:, exhaust
steam is used for ice making. Unusually good re-
sults are obtained.
In contracts for ice-making and refrigerating machinery
it is customary for the manufacturer to guarantee the capa-
city, to enumerate the temperatures to be maintained in cold-
storage rooms, and. if the purchaser is exacting, to insert the
guarantees for coal, steam, power and cooling-water con-
sumption. A test is usually made to see if the machinery
supplied fulfills the various requirements. Such tests are in-
structive, but for commercial reasons, probably, they seldom
get into print.
In the following only the acceptance tests of the equipment
of the refrigeration plant for the city of Lubeck, Germany,
are given.
The mechanical equipment of the "Kuhlhaus Lubeck" con-
sists essentially of one 17% and 29^4 by 29%-in. tandem-com-
pound Swiderski steam engine of 320 hp.. using superheated
steam, connected to a Balcke surface condenser. In the con-
nection between the low-pressure cylinder and the surface
condenser is inserted an oil separator. From the condenser
the condensate is taken to a reboiler for the purpose of ex-
pelling air and foreign gases, a portion of this water being
required for making distilled water ice. and the remainder
is returned to the boiler. The distilled water is forecooled in
a countercurrent cooler.
This main engine is coupled to a pair of 13x23%-in. double-
acting horizontal Borsig ammonia compressors of the opposed
type. A duplicate engine, intended for reserve, is connected
to a single ammonia compressor 13x23% in.
To take advantage of the increased capacity obtained when
operating with a higher evaporating or suction pressure, one
of the four ends of the double compressor unit is used only
for ice making, keeping the brine in the freezing tank at
about 19 deg. F. The guaranteed capacity of this compressor
cylinder half is 36.4 tons or
110,000 calories X 3.96S3 = 436,513 B.t.u. per hour.
The ice-tank room and brine tank are designed on the
Linde system, the brine-cooling coils being placed underneath
instead of between the cans. The rated daily capacity is 22
tons of 2000 lb. each.
With the 300- or 400-lb. American blocks the freezing time
is 42 to 60 hours, -while the small European 55-lb. blocks
(average size 7x7x35 in.) with 19-deg. brine freeze in IS. 4
hours; there are 612 of these small cans in the freezing tanks.
When cooling brine to 14 deg. F. for the cold-storage
warehouse the guaranteed capacity of any one of the com-
pressor cylinders is 61.15 tons of refrigeration. (One ton of
refrigeration = 2000 X 144 B.t.u. = 2SS.000 B.t.u. per 24
hours.) The brine is cooled by direct-expansion coils. The
brine tank has circulation partitions and agitators. Another
tank, supplied with cold water, is used for cooling the liquid
ammonia. The ammonia condensers of the atmospheric type
are on the roof.
From the flywheel of each engine a belt leads to a lineshaft
under the engine-room floor, and from this lineshaft are
driven two 70-kw. Siemens-Schuckert generators, one being
a spare. The boiler house has two Borsig water-tube boilers.
one a spare, built for 170-lb. pressure and superheating to 625
deg. F. Each boiler has 969 sq.ft. of heating surface.
The cooling water supply, guaranteed capacity 26S gal.
per minute, is obtained from two wells. The water in one
is lifted 131 ft. to the surface, in the other 98 ft., by a Borsig
air compressor, also in duplicate. The water is discharged
into a receiving basin near the boiler house, and forced to
the ammonia condensers by a belt-driven volute pump. A
duplicate pump, driven electrically, is provided for this serv-
ice. As a further safeguard for insuring uninterrupted oper-
ation, provisions are made for using city water if necessary.
For producing the necessary hot water for scalding pur-
poses in the abattoir a steam-heated hot-water apparatus is
erected in the boiler house: capacity 26.5 gal. of water per
minute heated from S6 deg. to 176 deg. F. Preheated water is
"Eis I"nd
•Excerpts from an article by Richard Stetefeld.
Kalte Industrie."
taken from the surface condenser, the latter in turn receiving
its cooling water from the ammonia condensers. In this
manner the water is utilized to the fullest extent. Steam
meters measure the quantity of live steam fed to the hot-
water apparatus. The plant is well equipped with all kinds
of indicating and recording instruments.
The following is abstracted from the report of acceptance
tests made after all the machinery had been installed and
operated during the summer of 1913.
BOILER TEST
Of the two boilers, which are alike, only the one which
happened to be clean at the time was tested, U being assumed
that the other boiler would have shown equal efficiency.
Date of test Oct. 18,1913
Type of boiler (Borsig Steilrohr Kessel) Water-tube
Number of boiler and year built 20,994 — 1913
Evaporating surface, sq.f t 969
Superheating surface, sq.ft 269
Grate surface (flat) total, sq.ft 36.2
Economizer, sq.ft 377
Guaranteed performance:
i:\aporation normally, 5070 lb. water per
hour; 396S lb. steam to be superheated.
Overall efficiency, per cent 76
Temperature of superheated steam, deg. F 625
Gage pressure, lb 170
Conditions:
Heating value per pound of coal as fired, mini-
mum B.t.u 11,500
Permissible residue, per cent 6
Draft after passing economizer, at least 0.6 to
0.8 in. of water column.
Feed-water temperature, not less than 95 deg.
F.; from economizer. 158 deg. F.
Coal analysis:
Average calorific value of coal sampled, 12,145
B.t.u. per pound as fired.
Results of test:
Date Oct. IS. 1913
Load Normal
Duration of test 4 hr. 2 min.
Temperature of fireroom 57.2 deg. F.
Draft at rear of boiler, in. water column 0.3
Draft after passing economizer, in. water
column 0.6S
Flue-gas temperature after economizer, deg. F. 405
Flue-gas temperature at rear of boiler, deg. F. 653
Per cent, of CO. 13.38
Per cent, of 0 5.72
Steam pressure, gage, lb 167
Steam pressure, absolute, lb 181.7
Temperature of superheated steam, deg. F. . . 62S
Temperature of saturated steam, deg. F 374
Amount of superheat, deg. F 253
Total heat of saturated steam (above 32 deg.
F.) B.t.u. per lb 1.197
Heat of superheat, 254 X 0.646 (spec, heat)
B.t.u. per lb 164
Total heat of superheated steam. B.t.u ^•*^1
Feed-water temperature to economizer, deg. F. 97.1
Feed-water temperature from economizer,
deg. F 1S1.3
Heat supplied in boiler, per lb. of superheated
steam. B.t.u.. 1361 — (97.1 — 32) = 1.295.9
Water evaporated during test, lb 21,076
Water evaporated per hour, lb • ■ 5,225
Water evaporated per hour per sq.ft. heating
surface, lb 5 . 39
Coal consumed during test, lb 2.595
Coal consumed per hour, lb 643
Coal consumed per hour, per sq.ft. grate sur-
face, lb 1 ' ■ 8
Water evaporated during test, per pound of
coal fired, lb. 522:, ^643 8.14
Heat contained in 1 lb. of saturated steam =
1197 — (97.1 — 32), B.t.u 1.132.9
Ash and refuse, percentage 9
Heat imparted to saturated steam per lb. of
coal as fired, B.t.u.. 8.14 X 1131.9 = 9,214
Efficiency of boiler and economizer, referred
to saturated steam, per cent.,
9214 B.t.u. in steam
100 X = '6
12.145 B.t.u. per lb. coal
At the time of this test it was impossible to ascertain the
steam consumption of the main engine, which would nave
shown the capacity of the superheater. Therefore, the over-
all efficiency of steam generation could not then be had.
However, a month later the steam consumption of the engine
was found to be 2SSS lb. of superheated steam per hour. The
work done by the superheater may, therefore, be taken at
2SS8 X 164 B.t.u. = 473.632 B.t.u.
This divided by 643 results in 736.6 additional heat units ob-
tained per pound of coal fired, making the total
9214 + 736.6 = 9950.6 B.t.u.
February 9, 1915
P 0 W E R
213
The heat utilized by the boiler, economizer and superheater,
based on coal as fired, is
9950.6
100 X = 82 per cent.
12,145
leased on combustible it is
9950.6
100 X = 90 per cent.
12.145 X 0.91
The number of pounds of superheated steam obtained per
pound of coal as fired is
9950.6
= 7. 68 per cent.
1295.9
A repetition of this test was deemed unnecessary because
substantially the same results had been secured at a prelim-
inary test.
TEST OF ENGINE COUPLED TO AMMONIA COMPRESSORS
An official trial of the tandem-compound main engine with
17% and 29V& by 29%-in. cylinders, of the poppet-valve type,
coupled to two 13x23%-in. opposed ammonia compressors, was
conducted. The reserve engine, a duplicate, was not tested
for steam consumption, because the indicator diagrams taken
from it under like conditions agreed with the diagrams ob-
tained from the main engine, proving that the power and
economy of the two engines in the plant are the same.
Dimensions and Conditions Imposed:
Diameter of high-pressure cylinder, in 17.718
Diameter of high-pressure piston rod. in 3.7.16
Diameter of high-pressure tail rod, in 2.749
Diameter of low-pressure cylinder, cold, in 29.525
Diameter of piston rod, crank end, in 4.12S
Diameter of piston rod. head end, in 3.736
Stroke, in 29.527
Revolutions per minute 95
Gage pressure of steam at throttle, lb 164
Temperature of steam at throttle, deg. F 572
Cooling surface of surface condenser, sq.ft 592
Amount of cooling water supplied per hour, cu.ft. . . 2120
Temperature of cooling water, deg. F 6S
Guarantees:
Indicated English horsepower of engine, normally 320
Indicated English horsepower of engine, maximum 394
Steam consumption per English i.hp.-hr., lb., at
normal load 10.5
Steam consumption per English i.hp.-hr., lb., at
maximum load 11.2
Mechanical efficiency of engine, per cent., at normal
load 89
at maximum load 90
As for guaranteed efficiency of the exhaust-steam oil sepa-
rator, the amount of oil remaining per thousand pounds of
condensate was not to exceed 0.003 lb.
Results:
Horsepower indicated 275 . 9
Revolutions per minute 95
Gage pressure of steam at throttle, lb 160
Temperature of steam at throttle, deg. F 576.3
Receiver pressure, inches mercury 5.7
Vacuum, inches mercury ^T'S
Duration of test, hr 4.8
The steam consumption of the engine was found to be 2S88
lb. per hour. In calculating the indicated horsepower from
the diagrams due allowance was made for the expansion of
the cylinders under working temperature. The result was
275.9 i.hp. Accordingly, the steam consumption per indicated
horsepower-hour during the test was
2888 lb.
■ = 10.47 lb.
275.9
The coal consumption per i.hp. per hour was
10.47
= 1.363 lb.
7.68
This consumption, it will be noted, was obtained while the
pressure of admission and the load were slightly below the
figures stipulated in the contract. The normal indicated
horsepower of 320 was not developed because the attached
ammonia compressors and auxiliary machines required less
than 320 i.hp. Diagrams show that the engine is easily
capable of developing 320 i.hp., and will not at this load ex-
ceed the consumption guaranteed. By lengthening the cutoff
the maximum power of 394 i.hp. may be obtained.
TESTS OF COLD STORAGE AND ICE PLANT
Of the two double-acting opposed Eorsig ammonia com-
pressors coupled to the engine one and one-half compressor
cylinders operate on the cold-storage plant, cooling brine to
14 deg. F., while the fourth compressor cylinder half operates
on the ice-making tank, cooling brine to about 19 deg. F. The
refrigerating capacity of the one and one-half compressor
cylinders was ascertained by measuring with Poncelet nozzles
the column of circulating brine cooled per hour through an
observed range of temperature. The fourth compressor-
cylinder half as well as the single compressor of the reserve
engine were indicated to ascertain their working conditions
and refrigerating capacity.
Dimensions nnd Conditions Imposed:
Diameter of ammonia compressors, in 12.992
Piston-rod diameter (no tail rod) 3.643
Stroke, in 23.622
Revolutions per minute 95
Exterior pipe-cooling surface, sq.ft. in brine-cool-
ing tank 3,229
in ice-making tank 1,292
in ammonia liquid cooler 291
in atmospheric ammonia condenser 4,338
Temperature of circulating brine in tank. deg. F. . 14
Temperature of brine in ice tank, normal, deg.... 19.4
Temperature, initial, of condenser water, deg 50.0
Temperature of liquefaction of ammonia, deg 71.6
Temperature of under-cooled ammonia, deg 52.7
Guaranteed tons refrigerating capacity of one
compressor when cooling brine to 14 deg. F.
equals
185.000 calories per hour
= 61.2 tons.
3023.95
Same for one and one-half compressor cylinders,
tons 91.8
Guaranteed daily ice-making capacity of one com-
pressor-cylinder half from distilled water
cooled to 53.6 deg. F., lb 44.000
Indicated horsepower of one compressor when
cooling brine to 14 deg. F 57.2
Indicated horsepower of one compressor-cylinder
half, cooling brine to 19.4 deg. F 33
Consumption of 50-deg. F. condenser water, gal,
per min 265
The power consumption expressed in horsepower was as
follows:
One and one-half compressor cylinders, cooling
brine 85.8
One-half compressor cylinder making ice 33
Steam-condenser pump 4.4
Water-supply pump 20.5
Brine-circulating pump 9.7
Brine-circulating pump 8.8
70 kw. X 1.34
Generator, = 101 . 5
0.925
Losses in transmission 29
Total 292.7
Dividing by 0.S9, the mechanical efficiency, the indicated
engine horsepower necessary according to the guarantee is
32S.4.
Capacity of brine-circulating pump for brine-wetted
air-cooler, per min., gal 396 . 5
for frosted air-cooler, per min. gal 396.5
Current consumption of ice crane, kw 2.5
Current consumption of fans, kw 13.5
Results of tests made Oct. 18 to 21, and Nov. 21. 1913. Re-
frigerating capacity of one and one-half compressor cylinders:
Quantity of brine circulated per min., gal 543
Heat capacity per gal. of salt solution per deg. F.
62.35 lb. X 0.946
temperature rise. B.t.u. = =.... 7.88
7.4805
Temperature of incoming brine, deg. F 19.9
Temperature of outgoing brine, deg. F 13 . 8
Temperature reduction of brine, deg. F 6.1
Heat abstracted from brine per min., B.t.u. 543 X
7.88 X 6.1 = 26,100
Corresponding tons of refrigeration performed by
26,100
one and one-half compressor cylinders, =. . 130.5
200
Excess capacity of the one and one-half compressor
cylinders over the capaeitv guaranteed =
130.5 — 91.8 = 3S.7 tons, or 42* per cent.
In connection with this brine-cooling test the following
interesting temperatures were noted:
Temperature of ammonia at suction pressure, deg. F. 5
Corresponding gage pressure, lb. per sq.in 19.1
Temperature of ammonia in suction pipe of com-
pressor No. 1, which operates with the same suc-
tion pressure in both ends, deg. F 4.1
Temperature of ammonia in suction pipe of com-
pressor No. 2. only one-half of which operates
on the brine tank, deg. F 6.3
Corresponding gage pressure, lb. per sq.in 20.2
Temperature of saturated ammonia at discharge
pressure, deg. F 74.6
Corresponding gage pressure, lb. per sq.in 125.5
Temperature of ammonia in discharge pipe No. 1
compressor, deg. F 187.7
Extent of superheating, deg. F.. 1S7.7 — 74.6 113.1
Temperature of ammonia in discharge pipe of No. 2
compressor, deg. F 182.2
Temperature of liquid ammonia leaving aftercooler,
deg. F 54-4
Temperature of ammonia entering brine-coolir.g
coils, deg. F 14.6
Temperature of ammonia vapor at inlet to atmos-
pheric condensers, deg. F. . 148 . 8
Temperature of liquid ammonia leaving condensers,
deg. F 65.4
Temperature of cooling water,
to liquid ammonia cooler, deg. F 48.9
from liquid ammonia cooler, deg. F 55.8
leaving ammonia condenser, deg. F 65.4
Under the above conditions the double compressor (with
cylinders Nos. 1 and 2) was running at 94.5 r.p.m., and the
"The amount of this excess capacity suggests the possi-
bility of error in the quantity or specific heat of the brine.
514
P ( I \Y E R
Vol. 41, No. (i
diagrams taken showed the following indicated horsepower:
Compressor No. 1. working full 78.85
Compressor No. -, one end only 3 9 . 1 rt
Total indicated horsepower 118.01
Thus the indicated compressor horsepower per ton of
refrigeration in cooling brine to 14 deg. F. was
lis. 'II
= 0.904 per ton.
130.5
while the guaranteed power consumption had been equiva-
lent to
57 -'
= 0.935 i.hp. per ton refrigeration.
mis
The piston displacement (area X stroke X r.p.m.) of com-
pressor No. 1 is as follows:
12.992- X 0 TV"! : 132.6 sq.in.
less one-half the area of the rod or 4.93 equals 132.6 — 4.93
= 127.67 sq.in.. winch, times the stroke of 23.6 in., is 3013
cu.in.; and this multiplied by 94.5 X 2 strokes = 569,500 cu.ln.
as the displacement of the cylinder.
The brine-cooling half of compressor No. 2 has a dis-
placement of 273,900 cu.in.. and the total for the one and one-
half cylinders is 843,400 cu.in. per minute.
Thus the piston displacement per minute per ton of refrig-
eration "when cooling brine to 14 deg. F. was 6419 cu.in.
The piston displacement of the head end of compressor
No. 2. making ice, is 3132 cu.in.. which times 94.5 strokes
gives 296,000 cu.in. per minute, or 40 tons of refrigeration
when cooling brine to 14 deg. F.
Since it requires, with the water available, at most 1.6 tons
of refrigeration to produce one ton of ice, the ice-making
capacity of this compressor-cylinder half is 28.7 tons in
twenty-four hours, or 26.3 tons for twenty-two hours' opera-
tion daily. The guaranteed capacity of 22 tons is, therefore,
exceeded.
The indicated horsepower of the fourth compressor-half
when cooling brine to 14 deg. F. was 39.65, equivalent to
39.65
= 1.38 i.hp. per ton of ice.
28.7
which corresponds to 1.55 i.hp. in the steam cylinder of the
engine.
During the brine-cooling test the cooling water was sup-
plied by the electrically operated volute pump located in the
boiler house. The quantity delivered at 19S5 r.p.m. was
found to be 252 gal. per min. Consequently more than the
normal quantity of work was done with less water than the
26S gal. allowed under the guarantee.
The power indicated at the main engine was 2S3.32 i.hp..
and the total power consumption of the establishment was
but 9 per cent, more than was guaranteed.
The delivery capacity of the deep-well pump also was
checked by noting whether the water level in the receiving
basin remained constant while the cooling-water pump was
discharging to the condensers at the rate of 268 gal. per min
It was found that even then some water returned to the wells,
consequently the well pump was fully up to the capacity
guaranteed.
The various features of special interest in the plant are
the consistent use of reserve machinery, the obtaining of all
power from one economical engine using superheated steam,
making ice as a byproduct from exhaust steam, the efficient
boiler plant, also the comparatively high rotative speed of the
compressors (95 r.p.m., against SO to 60 in this country). The
low coal consumption and low power consumption lead to
an unusual economy in the ice-making department. The
coal consumption per indicated horsepower-hour was 1.365 lb.,
or 32.76 lb. per twenty-four hours. This, multiplied by 1.55
i.hp. per ton ice, equals 50. S lb. Increasing this by 33?: per
cent, to cover all possible auxiliaries, the total is 67.7 lb.
Thus the number of tons of ice made per ton of coal fired is
:
= 29.5.
67.7
In American plants 10 tons of ice1 per ton of coal is consid-
ered quite satisfactory. It must be remembered in this con-
nection that the initial temperature of the cooling water
was 50 deg. F.. the suction pressure nearly 20 lb. gage, and the
condenser pressure only 126 lb. gage. The remarkable econ-
omy of this plant is directly traceable to these favorable
operating conditions and to the use of a compound condens-
ing engine using highly superheated steam for driving the
compressors and for all the auxiliaries of the plant. The re-
quired distilled water for filling the ice cans was obtained
only because the refrigerating effect needed to make the ice
was only 26 per cent, of the total refrigerating effect pro-
duced by the two compressor cylinders. The total amount of
n passing through the engine was 34 tons per day. which,
after deducting the water of condensation and ether losses.
would not have yielded quite enough distilled water for mak-
ing the maximum of 29.5 tons of ice per day.
lEimgpiini©*
By Henri G. Ciiataix +
The object of this paper is to describe and discuss the
features of design of an eight-cylinder, four-stroke cycle gas-
oline engine, which has been developed during a number of
years for railway traction.
Fig. 1. Side View of Eight-Cylinder Engine
The problem .vas to design a complete motor car for
branch railway service, of sufficient size for seating fifty pas-
sengers and a small baggage compartment, etc., and capable
of attaining a maximum speed of 50 miles per hour on level
track. The first design included an eight-cylinder V-type, 90-
deg. engine, with cylinders 71oxS in., and running normally at
550 r.p.m. This operated commercially in a little car on a
Western road until quite recently, when it was destroyed by
Fig. 2. Timing Diagrams
fire. The second attempt was a larger and heavier engine of
essentially the same type. This was run experimentally in
service 50,000 miles in one year on various roads, and served
its purpose admirably in showing up some glaring defects,
among which were the following:
1. The exhaust valves needed regrinding once a week, as
they were unduly distorted and burnt.
2. The camshaft and valves were extremely inacces-
sible.
3. It was uncommercial to make the cylinders sufficiently
strong.
4. It was difficult to mount the engine in the car so as to
take care of the horizontal component of the reciprocating
forces: hence, there was vibration.
5. The total width of the engine was excessive.
With these facts at hand and an ever-increasing demand
for more power, the third and present engine, which fulfilled
expectations and met conditions, was designed. Fig. 1 gives
•From a paper presented before the Society of Automobile
Engineers.
^Engineer, Gas Engine Department. General Electric Co.
February !), 1915
P 0 W E E
215
an idea of its construction. To overcome the first difficulty
mentioned, auxiliary exhaust valves with port entrance to
the cylinders were embodied in the design. The cams actu-
ating- these valves are so laid out that the valve is entirely
free of its seat when the piston passes the port opening. The
liming is shown in the diagrams of Fig. 2. This arrangement
Fig. 3. Showing Cylinder Construction
has worked well, and the auxiliary valves need practically
no attention except about once a year. The exhaust valves
in the head need to be ground about every 50,000 miles.
The second change was the relocation of the camshaft due
to its inaccessibility, and also because the stroke of the en-
nine was to be lengthened. Two externally located camshafts
Fig. 4. Eeciprocating Forces of 90-Deg. and 45-Deg.
Engines
were decided upon, with the cams, shafts, etc., running in a
bath of oil. One actuates the auxiliary exhaust valve, and the
other imparts the proper motion to the long push rod extend-
ing to the top of the cylinder and connected to the intake and
exhaust valves.
In an engine of lliis size the L-head form of cylinder had
little to recommend it The castings had to be made very
heavy, otherwise they would crack; and heavy castings in-
terfere somewhat with tin- cooling. lOxtremely strong con-
struction at this point was essential. Pig. 3 shows the form
of cylinder construction adopted, namely, a barrel, a head and
1 ■ I tained (herein, held down to the base by long-
studs. Note that the water circulating systems of the head
and the barrel are distinct. The arrangement of two valves
actuated from one cam is riuite satisfactory :it 500 to 600
r.p.m. "With higher si is the design would be unsatisfactory,
as the mass of the moving parts would necessitate unduly
high spring pressures. In Fig. 3, A indicates the make-and-
break spark plugs, E the air-starter valves, C and B the water
inlets, and D the exhaust ports.
A 45-deg. angle between the rows of cylinders was decided
upon, to decrease the horizontal component of the reciprocat-
ing forces as well as the overall width. Thus each cylinder is
set 22% deg. from the vertical.
Tlie crankshaft has four crankpins, of which the two outer
are ISO deg. from the two inner pins and two pistons are at-
tached to each pin. The connecting-rods are mounted side
by side on each crank. It was thought advisable to adopt this
construction for mechanical simplicity. The piston-pins are
held fast in the rods and find their bearings in the piston
proper. No bushings are used.
The reciprocating forces for one cylinder along its axis are
0.0000284 X W X r X N! (cos 9 +
W = Weight of reciprocating parts = 59 lb.;
r = Crank throw in inches = 5;
N = R.p.m. = 550;
n = Length of connecting-rod divided by throw of crank
= 4.5;
8 = Crank angle in the direction of rotation from top dead
center of piston.
Fig. 4 shows the reciprocating forces for this engine rep-
resented graphically and compared with the 90-deg. cylinders.
The specifications of this engine are as follows:
Cycle 4
Number of cylinders 8
Revolutions per minute 550
Stroke 10 i
Displacement 503 <
Valve area: Inlet 7.07 i
Exhaust 4 91 e
Valve lift j i
Mean velocity of air in intake pipe 7100 f
Exposed radiating surface per cylinder: Max 384 sq.i
Min 133 sq.i
Section of connecting-rod:
Projected bearing surface: End
Center 15
Max 2 . 58
Min 1 57
Number of bearings 5
Length of cylinder 23£
Length of piston 1 1 g
Piston-pin center below piston top 5jj
Number of rings 6
Ring size J
Ring spacing j
Length of connecting-rod, c. to c 22 \
Diameter of piston-pin 2
Diameter of shaft 4
Length of end bearings . . 0
Length of center bearings 33
Number of camshaft bearings 4
Length of camshaft bearings 2'
Diameter of camshaft . . , 1 \
Cylinder-wall thickness \
Water space around cylinder }
Height overall 6 ft. 32
Length less generator 7
Length in. ■hiding generator 9 ft. 3
Width overall 4 ft. 7J
sq.Ill.
sq.in.
sq.in.
Last year a sample of coal from the Bering River field in
Alaska was tested by the Navy Department and found to be
unsatisfactory for the use of the navy. A test has since been
made with coal from the Matanuska field, of which Admiral
Griffin says:
Unlike the tests that were made with Bering River coal
last year, it was not necessary to hand-pick the Matanuska
coal for the purpose of these tests. It was used in the same
condition as when delivered, and the results are so satisfac-
tory as to justify the belief that Matanuska coal is in all
respects satisfactory for navy use, provided the coal tested
is a thorough indication of the general character of the coal
in the field.
Secretary Daniels said at a recent hearing that it compared
favorably with the best steaming coal that the navy has, and
that it was put down at 97 per cent, against 100 for the best
coal.
216
POWER
Vol. 41, No. 6
ussacal©!? stiff"©®®''"
By James E. Howakd
The efficiencies of riveted joints under rupturing tensile
stresses constitute the values on which working loads are
commonly based. Alleged factors of safety are employed,
fortunately not less than five on important work, because
a fairly good distribution of load is not always characteristic
of riveted construction. The most important feature, how-
ever, is in the elastic behavior of the joints, which appears to
be ignored. As a matter of fact, few riveted structures are
free locally from strains which do not exceed the elastic limit
of the material. The structures are not necessarily endangered
by the presence of such overstrains, as this will depend upon
the character of the work to be performed. Multiple-riveted,
double butt-strap joints may have a degree of rigidity equal
to or even in excess of the solid plate for comparatively low
tensile or compressive stresses, but loads ranging from, say.
15,000 to 25,000 lb. per sq.in. commonly show a material
divergence in the behavior of a joint over that of the solid
plate.
When frictional resistance contributes toward the initial
rigidity of the joint, it is uncertain whether the favorable
showing of the joint in the laboratory test is realized and
maintained under service conditions. Vibratory effects and
changes in temperature seem likely to cause a creeping of
the plates and disturb the initial state of the different plies,
when taken in conjunction with a constant load, or, it may
be more marked, in the case of alternate stresses.
Referring specifically to the strength of those parts on
which reliance is placed in the design of a riveted joint, first
comes the tensile strength of the plate taken as a whole;
next to this the strength of the steel between the rivet holes —
that is, on the net section. On the latter section the strength
per unit of area is not the same with different pitches. It
may be greater or less than that accredited to the gross
section per square inch It is also modified according to
whether the holes are drilled or punched, and may be greater
in one case or the other according to the distance from rivet
hole to rivet hole. It is not likely that the strength with
punched holes will be greater than with drilled holes in
practice, since very closely pitched work is required to bring
about such a result. The reason, however, that a punched
plate may display greater strength than a drilled one is found
in the hardening of the steel by the punch and die at the sides
of the holes.
The tensile strength on the net section of the plate is
usually greater than on a strip of uniform width several
inches in length. The increased area of metal on each side
of the center line passing through the rivet holes has a
reinforcing effect on the net section of the plate. This gain
in strength is a substantial one in single-riveted work, and
in multiple riveting when the same pitch is maintained in the
different rows. The reinforcement is greater in close-pitched
than in wide-pitched riveting, and is at the sides of the holes,
but if they are very far apart there results a loss instead of a
gain. The reinforcement is therefore not a fixed amount, but
depends upon the proportions of the joint.
When the pitch has been considerably increased, as in
butt joints with double covers, in which one strap is con-
siderably wider than the other, joints which fail by the rup-
ture of the plate net infrequently show a diminution in
strength on the net section, and the plate tears apart at
the outside row of rivet holes. The presence of a few rivets,
widely spaced, in the outside row promotes tearing of the
plate, the line of rupture starting at a rivet hole and reaching
an advanced stage before the plate at the middle of the pitch
is separated.
Tests on staggered riveting have shown a tendency for
the plate to draw down along shearing planes, obliquely
to the direction of pull, encountering a rivet in the adjacent
row. That is, the design of the joint was such that those in
adjacent rows occupied critical positions with reference to
each other, and while the zigzag path from one row to the
other was longer than from rivet to rivet of the same row,
nevertheless the plate showed a preference to fracture along
this greater length, and the interposition of rivets in the
second row in critical places was a probable source of
weakness.
Chain-riveted work creates a favorable impression when
observing and comparing the behavior of different types of
joints under test. The distance between rows in chain rivet-
ing admits of being very much reduced over current practice
without impairing the ultimate strength of the joint.
It will be of interest to refer to the strength of riveted
joints at higher temperatures. Under exceptional circum-
stances the joints of steam boilers might be exposed to
temperatures considerably above that due to the steam pres-
sure. Joints have been tested up to a temperature of 700
cleg. F., and the strength was found to follow the law which
governs that of plain steel bars at different temperatures.
There was a drop in strength at 200 deg., followed by an
increase, which reached a maximum at about 500 deg., after
which the strength fell off. Among the several joints tested
at 500 deg. the maximum gain over the cold joints was 27.6
per cent. The shearing strength of the rivets showed an in-
crease at the higher temperatures. Furthermore, it was
found that joints which were overstrained at these higher
temperatures, even beyond the limits of duplicate cold tests,
when subsequently tested to destruction at ordinary temper-
atures, retained substantially the strength which they had
when hot. There was some loss in the ductility of the steel,
but without approaching a state of brittleness.
So much for the ultimate strength of riveted joints. At-
tention must be given the behavior of the joints under stress
and whether the working loads are constant or variable,
direct or reversed stresses, and in the case of repeated
stresses, how many repetitions there will be and the maximum
stresses involved. The examinations of some stress-strain
curves prepared from earlier tests shows that the joints in
general take a wide departure from the curve representing
the solid plate, this being noticeable at 15,000 lb. per sq.in.. and
in some joints as early as at 10,000 lb. This was true with
joints having efficiencies of 70 to 80 per cent. Among the
joints thus compared were double- and triple-riveted butt
joints and quintuple joints in which the inner butt strap was
wider than the outer one.
Under 15,000 lb. per sq.in. the joints, in general, displayed
an extension one and a half times to over twice the extension
of the solid plate. These joints were of the types which are
used in steam boiler construction. Observations on the be-
havior of double-riveted lap joints on some steam boilers
which had been in service showed greater extension across the
longitudinal seams at the middle of the sheets than in the
vicinity of the girth seams.
It is of interest whether riveted seams retain their primi-
tive state under prolonged service' stresses or whether they
do not slip and eventually display increased extensions under
lower loads than suggested by the laboratory tests. From
the limited number of observations made it cannot be said
that the rigidity of joints on actual structures is greater
than would be expected. If there is a difference, they are
probably less rigid in actual structures.
The frictional resistance due to the shrinkage of the rivets
is apparently a factor in the early behavior of a joint.
Whether this force drawing the plates together is acting to
its full extent will depend upon the manner in which the
riveting is done. A limited range in temperature in cooling
is sufficient to apply a contractile force equal to the elastic
limit of the rivet metal. But since the hot rivet metal has
a very low elastic limit it is necessary to hold the plates to-
gether firmly until the rivet has cooled to nearly its final
temperature. This requirement is an obstacle to rapid driv-
ing, but full efficiency in frictional resistance between the
plates requires its observance.
•From a paper presented at the twenty-second general
meeting of the Society of Naval Architects and Marine
Engineers.
CONCRETE TILE STANDARDS. By Huntley Abbott. Pub-
lished by Huntley Abbott, 11 Pine St., New York City.
Paper; 59 pages. 9x12 in.; illustrated. Price 50 cents.
DRAKE'S TELEPHONE HANDBOOK. By D. P. Moreton.
Frederick J. Drake, Chicago, 111. Cloth; 2S6 pages, 4x6%
in.; 161 illustrations. Price, $1.
A Coal Treatment Alleged to Be Advantaceous — There has
recently been in Germany quite a flood of preparations put
upon the market for the purpose of making a brew in -which
coal or coke is to be wetted before being put upon the fire.
The alleged result of using these preparations is that the
coal burns more readily and that there is a great saving
in the amount of fuel required. Herr T. Oryng, of the lab-
oratory of the Berlin Fermentation Institute, has analyzed
a number of these preparations and found them to consist
of various salts, such as sulphate of magnesia, sulphate of
soda, common salt, nitrate of soda, and so on, generally with
a small proportion of oxide of iron. He concludes that they
cannot have the effects attributed to them. — Foreign Ex-
change.
Vol. II
POWER
NEW YORK, FEBRUARY L6, 1915
Create $he Opporfttuimtty
'JTHE man who "makes good" usually has to
create his own opportunity.
We often hear it said: "Wait until the oppor-
tunity offers itself." Many men are still waiting.
Many men will be waiting when they are old and
gray.
We might as well say to a salesman: "Wait
until business offers itself! Wait until business
comes to you!"
The successful salesman is he who creates his
own business; his own opportunity, in other words.
He is the man who uses his head, and gets all there
is out of his own faculties, education and energy.
In a like manner the successful engineer or the
successful man in any other job is he who creates
his own opportunity — make yourself so valuable
to your employer that he cannot do without you.
When this point is reached you are on the road
to advancement and success.
A man may arrive at his work before the whistle
blows in the morning — he may not leave until
after it blows at night.
Yet— he does not earn his salary if his mind is
not on his job. And even if opportunity does
knock at his door he will be asleep and it w'ill pass
on to the next fellow. But, you are as good as
the next fellow if you only realize it.
Therefore:
Pow«n
1111 nmmii iiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiiiiiiii i i iiiniiiii Hiiiiiiiiiiiiiii it
Wake up! Put your mind to your work! Think! Be
a little bigger than your job! Create an opportunity!
and the future will be bright and rosy.
You can do it-
riiuiFNiinii; nniiiiiirriiiriii iiiinim Illllilllililiiiliiiliiiuiiiiiii
[Wr,
K B.Lamb, I
minimi iiiinmii
218
P 0 W E K
Vol. 11, No. :
'ujiMcipal Flaunt
By Thomas Wilson
SYNOPSIS — Modern 1200-kw. plant, arranged
on the unit plan, supplies current for sired light-
ing and eventually will enter the commercial field.
( 'osi of installation and opera/in;/ expense. A
feature is a provision to utilize auxiliary exhaust
-team in the lower stages of the turbines.
simr 1895 Kalamazoo. Mich., has had a municipal
plant for street lighting. Are generators supplied
about 100 lamps operated on a m ilight schedule.
With the growth of the city, which now has a popula-
tion of about 15,000, the service became inadequate,
and after 17 years of use. both machinery and lamps
were out of date and inefficient. Late in 1912
the city issued bonds to build a new plant, to re-
habilitate the are system and, in the downtown dis-
trict, to install an ornamental system of stand-
ard five-light units. During the year 1913 the
plant was erected and in February, 1914, operation be-
gan. The service is from dusk to dawn every night
and the average daily period of operation is 12 hours.
The plant is near the
Kalamazoo River, so that
an abundant supply ol
cooling water is .available
fur the condensers. As boil-
er Iced it is used only
when the city supply fails,
as the river water is mud-
dy and contains acid from
the discharge of paper
mills. A spur from the
Michigan Central R.R. enters the property to facilitate
coal delivery.
The exterior of the building (Fig. 1). which rests on
concrete foundations, is built of brick supported by steel
framework and is covered by a flat concrete roof. Its
present dimensions are 52x100 ft. and one end is sealed
with sheet iron, so that an extension may be easily
made to house the additional equipment necessary when
funds are available to enter the commercial field. Pro-
vision has also been made for overhead coal bunkers,
special coal- and ash-handling systems and a traveling
crane in the turbine room. These improvements arc
indicated in dotted lines in Fig. 5. They will be in-
stalled at a future period.
The plan and sectional elevation, Figs. 5 and 6, show
that the layout has been arranged on the unit system.
Each boiler connects directly with a turbine, although
for protection against shutdown the steam-supply pipes
are cross-connected. There is a feed pump for each
boiler and a concrete stack serving both units. The
present equipment consists of two boilers rated at 310
hp. each and two liOO-kw.
turbo-generators with their
condensers and auxiliary
equipment. For each kilo-
watt of turbine there i~
0.52 boiler horsepower. At
rating each turbine alone
calls for 9720 lb. of steam
per hour. The steam is
supplied at 200 lb. gage
pressure and an average
Fig. 1. Exterior of Kalamazoo Municipal Lighting Plant. Fig. 2. The Two 600-Kw. Generating Units
February 16, 1915 P U W E R 219
superheat of 150 cleg. The cost of the installation is is to have a wet coal storage into which the coal will lie
given in Table 1 : dumped from railroad cars. A gantry crane with a
table l— cost of station grab bucket will pick up the coal and deliver it through
i£ckns: ^!?.ana. e"ei™°""K .*'^ .:/:..'. ::::::::::: *^M<> the roof into overhead coal bunkers, each having a ca-
Equi'ifm'e'nt .'.'.'.'.'.'.'.'.'.'.'.'.'.v.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'. ikiit pacify of 85 tons. A iitomat ic scales and a chute to each
563' stoker hopper will complete the equipment. Ashes will
cost per k'iiowatt of turbine capacity, $79.64. be discharged into a hopper underneath the boiler-room
The various items include all labor and installation floor thence into an ash car. The latter will be
charges, but the amount charged for equipment does not wl led to the end of the building, raised by a hydraulic
take into account the cost of rectifiers, lamps, or other hoisl to the firsl floor and its contents will be delivered
apparatus belonging to the lighting system proper. Omit- to a section of the coal-storage pit reserved for the pur-
ting the building and engineering fees, the cost per kilo- pose. The crane can then be used to load the ash into
watt reduces to $46. At present the building item is the ears which deliver the coal.
Pig. 3. Vertical Water-Tube Boilers and Under-
feed Stokers
Pig. 1.
Condenser Auxiliaries in the Con-
''ensei; Pit
top-heavy, but the additional capacity soon to be installed
will reduce the unit cost considerably.
Boiler Room
Vertical water-tube boilers were stlected. Each has
3089 sq.ft. of heating surface and Id I sq.ft. in the super-
heater. As shown in Fig. :!. underfeed stokers serve the
boilers and forced draft is supplied by a 1 10-in., three-
quarter-housed steel-plate fan driven by either one of two
vertical engines, one on each side of the fan. The speed of
these engines, and consequently the draft, is controlled in-
directly by the steam pressure through automatic re-
lators. The slack rises 1 15 ft. above the boiler-room floor.
The inside diameter at the bottom is 8 ft. and a taper of
1 in. to every •"> ft. reduces it at the top to 5 ft. 6 in.
At present the coal is stored in a temporary shed. It
is loauul into a car which passes over a platform scale on
its way to the stokers. The ashes are wheeled out and
disposed of on the premises. Much better facilities have
been provided for the ultimate construction. The plant
West Virginia slack averaging about 13,000 B.t.u. per
lb. is the fuel burned. It is bought on the B.t.u. basis
established by the Bureau of Alines and the cost is close to
$2.70 per shori ton.
Generating Units
Horizontal four-stage turbines of the velocity I type drive
three-phase, four-wire generators at a s] d of 3600 r.p.m.
(Pig. "'). Sixty-cycle current is supplied at a'voltage of
3300 or 1000, and the rating of the turbines at SO per
cent, power factor is 600 kw.
The steam-supply pipes to the turbines are 5-in. di-
ameter, and with a rate of 10.2 lb. jaer kw.-hr. at normal
load, 9720 lb. of steam per hr., or 102 lb. per min., must
How to the turbine. At 200 lb. gage, pressure and 150
deg. superheat, the volume of this. amount of steam is
434.10 cu.ft. The velocity of the steam in the supply
pipe is then
1:34.16 -r- 0.1389 = 3126 ft.
or, in round numbers, 3100 ft. per min. For a turbine
220
P 0 \V E II
Vol. 41, No. T
this velocity is low. A supply velocity of 8000 ft. per a 16-lip. turbine at 1000 r.p.m. and a 7-in. circulating
min. is not uncommon in the present-day practice. A pump capable of delivering 1200 gal. per min. The
smaller supply pipe could have been used, but in the pres- latter is driven by a 25-hp., 410-volt motor which receives
ent case the saving in first cost would have been negligible, its current from the generator leads through a step-down
Each turbine is served by a three-pass surface condenser transformer. This connection was made to facilitate
having 1600 sq.ft. of surface. This is an allowance of starting and to insure the presence of cooling water as
hi
■
At
'L V;
N
in
IS
COAL S70RME PIT
Fig. 5. Sectional Elevation thhough Station, Showing Proposed Coal- and Asm-Handling
Facilities
Fig. 6. Plan of the Station
'.'-;; sq.ft. of surface per kilowatt of turbine rating. At
'.'S-iu. vacuum and with ?5-deg. cooling water, the con-
dense]- is guaranteed to care for S500 lb. of steam per
br. This reduces to 5.3 lb. of steam per sq.ft. of con-
densing surface. The auxiliaries (Fig. It area combined
air and condensate pump of the radial jet \\\k driven by
soon as the main unit is put into operation. It was
thought that one steam and one electrically driven auxil-
iary would make a more flexible out lit than two similar
units. From the feed pumps, stokers, fan engines and
the turbines operating the air pumps there would be
more than enough exhaust steam to heat the feed water.
February 16. 1915
P 0 W E It
221
and turbine-driven circulating pumps would only increase
the surplus.
Turning Exhaust Steam into Tubbines
To utilize the exhausl steam from the sources just men-
tioned to best advantage, the ingenious plan shown in
Fig. ~, has been adopted. Each of the steam-using auxil-
Turbine
Aut Reg. r
Valve
Check
Valves
Aut Reg
Valve *
Back
Pressure
Valve;
•a
□Feed Water
Heater
TURBINt R.OOM
BOILER. ROOM
Fig.
Piping fob Utilizing Exhaust Steam
iaries discharges into a common exhaust system which en-
ters the feed-water heater and is also tapped into the
fourth stages of the main turbines. To the latter auto-
matic regulating valves control the supply, and check
V es prevent steam flowing from the turbines to the ex-
haust system. The heater uses as much steam as it re-
quires. Any excess builds up the pressure in the system,
and when it exceeds the pressure at the points of entrance
to the turbines, the automatic valves open and admit the
surplus. This usually occurs when the turbine is carrying
a light load. A back-pressure valve opening to the at-
mosphere protects the system.
In another plant this idea has been completed by
the same engineers so that exhaust steam may enter the
turbine or steam may pass from the turbine to the ex-
haust system, depending on the relative pressures. The
connections are shown diagrammatically in Fig. 8. Two
back-pressure valves are employed. The one at A opens
toward the turbine and valve B toward the exhaust system.
These valves are set at approximately 2 lb. pressure. If
the turbine is heavily loaded and the pressure at the point
"i entrance is relatively high, valve A must remain
i losed and valve J! will admit steam to the system. With
conditions reversed and the pressure greater in the sys-
tem, valve .-1 opens and admits steam to the turbine. As
usual, an atmospheric relief valve set at a higher pressure
than the other valves, affords protection against a pos-
sible emergency.
Switchboard and Line
Fig. 9 shows the front of the switchboard, which has
11 black-slate panels and four double blue Vermont arc
panels set out 11 ft. from the wall. The board is equipped
with the latest instruments and provides for remote con-
trol. Back of the board are the oil switches, instru-
ment transformers, etc., mounted on pipe framework, and
four of the mercury arc rectifiers. There is a total of
eight 75-light outfits, four being in the basement. Ii
will be noticed in Fig. 10 that the wiring is unusually
neat and accessible and that there arc free passageways
immediately behind the board and between the switches.
Fig. 11 is a view in the basement showing rectifiers, cut-
out- and the entrance of the cables into the underground
ducts. Aliont 225 ft. from the station the cables are
brought up through iron-pipe risers to a terminal tower
am! by means of flexible jumpers are connected to the
pole line lead-.
The 534 luminous arc lamp-, each taking 1 amp. at 80
\olts. are hung on 12-ft. mast arms and are equipped
with a special cutout to protect the trimmer againsl the
high voltage of the circuits. These arcs serve the resi-
dence district, the business center being lighted by 234
ornamental (ive-light posts spaced 75 ft. apart on both
sidi - of the streets. The top lamp of cadi cluster is rated
.it LOO watts and the four side lamps take 60 watts each.
For the illumination of alleys there are II four-ampere
tungsten lamp.-. The city hall is also lighted by the plant.
Operating Costs
\- previously stated, the plant is operated from dusk
to dawn own night in the year, irres] five of the phase
of the moon. One boiler is banked through the day, but
two shifts of employees are required. Seven men are em-
ployed in the plant — one chief engineer, two assistant en-
gineers, two firemen and two day men. The period of
daily operation averages 12 hr. and as the entire load is
lighting, it remains practically constant. Up to midnight
the load averages 280 kw. The lower lamps of the orna-
mental clusters are then cut out and the load drops to
230 kw. The total kilowatt-hours for the night, then,
average 3060. In this, however, the current for the air-
pump motors is not included, as the supply to these mo-
tors is tapped directly from the generator leads and is
not metered.
On an average from Apr. 1 to Sept. 1, 5.85 tons of coal
were burned per night; from start to midnight, 5800 lb.:
Sources of Exhaust Steam
Fig. 8. Improved Abbangement Allowing
si i \m to Flow to ob t'lioM the Turbine
from midnighl to shutdown, 4800 lb., and 1100 lb. were
required for bankii ,„. This is an average of 3.82 lb. per
net kilowatt-hour. In the above period, containing 153
days, the total money spent on the plant for coal, labor,
supplies, etc., was $7249. This figures $47.38 per day.
and dividing by the output gives an operating cost of
1.55c. per kilowatt-hour. A fixed charge of 12 per cent.
for interest, depreciation, taxes and insurance on an in-
vestment of $95,563, the total cost of the plant, amounts
to $] L,467.56 per year, or $31.42 per day. and, based on
the present net load, 1.02c. per kw.-hr. Adding the operat-
POWEI!
Vol. 41, Xo. V
Fig. 9. Front View of Switchboaud and Arc Panels
ing and fixed charge? gives a total cost of 2.57c. per
kw.-hr.
As might naturally be expected, the cost of putting a
TABLE 2 — RESULTS OF TESTS OX BOILERS
Boiler Boiler
Total Quantities, Lb. — No. 1 Xo. 2
Total water evap., corrected for losses, lb. 67,054.00 70,!
Total coal fired, lb S, 911. 00 9,193.00
Total refuse, lb 912.00 953.0(1
Total ash in refuse, computed from anal-
ysis, lb s:;o.oo S67.50
Total combustible in refuse, computed
from analysis, lb S2.00 S5.50
Total equiv. water evap. into dry steam
f. and a. 212 ties:. F ". 75 05.0 1.281.00
Temperature. Degr. F. —
Av. temp, of feed water 200.50 198.80
Av. temp, of steam at superheat outlet.. 502.00 544.20
Av. superheat 120.00 162.20
Av. temp, of flue pases 501.00 495.50
Pressures —
Av. steam pressure, gage, lb. per sq.in... 194.70 197.40
Av. steam pressure, absolute, lb. per sq.in. 209.40 212.10
Flue Gr-ses—
Av. CO- contents of flue gases, per cent... 9.50 LI. 50
Av. CO contents of flue gases, per cent... . 0 7" 0.50
Ay. O contents of flue gases, per cent 3.00
Coal— ' v '
Moisture in coal, per cent 4.42
Volatile matter in coal, per cent
Fixed carbon in coal, per cent
Asli in coal, per cent 10.36
Sulphur in coal, per cent 0.90
B.t.u. per pound of dry coal 13,245
Ash-
Ash, per cent 91.32
Volatile combustible matter and fixed
carbon, per cent S.68
Capacity —
.Maximum hp. developed 300 300
Hated hp 310 310
A v. hp. developed 225 ll1:,
Evaporation — •
Water evap per lb. of coal as fired, lb... 7.53 .71
Equiv. evap. f. and a. 212 deg. per lb. of
coal as fired S.52 9.11
Equiv. evii, f and a. 212 deg. F. per lb.
of dry ,ial S.90 9.52
Equiv. evap. f. and a. 212 deg. F per lb.
of combustible 1 •' 4 T 11.20
Efficiencies —
Efficiency of boiler, furnace and super-
heater, based on dry coal, per cent 65.20 70.00
Efficiency of boiler, furnace and super-
heater, based on combustible, per cent. 76.70
Loss of combustible, per cent, of coal fired 0.9] 0.91
Heat Balance —
Heat value of fuel utilized, per cent 65.20 70.00
Heat value of fuel lost, per cent 0.91 0.91
Heat lost by radiation, conduction and
in stack, per cent 29.19
kilc i watt-hour on the line is high, but considering the
conditions, the showing is excellent. The plant was de-
signed for a much larger load than it is now carrying, and
TABLE 3— RESULTS OF TESTS OX GEXERATIXG UNITS
Approximate
Load on Turbine, KW.
Total Quantities — 600 450 300
Weight of condensate, including
leakage, lb 18,256.0 15,057.0 7,811.0
Actual steam consumption, corrected
for leakage, lb 16,971.0 14.476.0 7.12.."
Total energy generated bv generator,
KW.-hr 3,070.0 940.0 45". o
Hourly Quantities — ■
Leakage per hour 257."
Av. power developed by turbine, kw. 614.0 425.0 300.0
Average Temperatures, Deg. F. — > y— ;
Av. temp, of room at mercury column
Av. temp, of steam (superheated) at
throttle 540.6
Av. temp, of steam (saturated) at
throttle 380.6
Av. deg. of superheat 160.0
Av. temp, in exhaust nozzle of tur-
bine 74 5
Temp, due to av. vacuum in exhaust
nozzle £2.0
Av. temp, of condensate 72.5
Av. temp, of circulating water in-
take 59.5
Av. temp, of circulating water, dis-
charge 69.5
Average Pressures —
Av. pres. of steam at throttle, gage,
lb 196.0
Av. pres. of steam at throttle, abso-
lute. 11. 210.7
Av. vacuum in exhaust nozzle, in. hg.
(corr. for temp.) 28.5
Av. reading of barometer, in. hg.
(corr. for temp.)
Av. abs. press, in exhaust nozzle,
in. hg 11
Av. abs. press, in exhaust nozzle, lb.
sq.in o.-.t
Economic Results —
Actual consumption of steam per
kw.-hr., lb 15-3 15.4 16.5
consumption of steam per kw.-hr.
(corr. for conditions of steam and
vacuum upon which guarantees are
based), lb 15.9 16. o 17.1
Guaranteed consumption of steam
per kw.-hr. (based on 200 lb. gage
press.. 150 deg. superheat at throt-
tle. Abs. hack pressure 2 in. hg.),
lb ! 16.2 16.2 1.4
Consumption of coal. lb. per kw.-hr.:
(a) Turbine without auxiliaries... 2".
(b) Turbine with auxiliaries 21
to w e i;
22:1
:is soon as the city enters the commereial field, it is ex-
pected that additional generating capacity will be re-
quired. At present only one unit is maintained in opera-
tion at less than half load fur 12 hr. out of the 24. The
overhead expense imposes a heavy burden on small output.
The double shifts make the labor cost high, and coal for
banking adds to the fuel cost. With a commercial load
requiring current during the day. tin' plant, would he kept
in continuous operation and the generating units would
he operated at about rated capacity. There would he less
loss from banking the tires and some returns for the work
of the day shift. The total output would lie much larger
at but little additional expense, so that the cost per unit,
would be greatly reduced.
is not as high as might he expected, hut is attributed to tne
fact that the boiler was started cold, so that a certain
amount of the fuel was required to heat up the setting.
The efficiency of 70 per cent, obtained on No. 2 boiler is
good, considering the fuel burned, which is West Virginia
slack of the analysis given in the table.
The results of the tests on one of the generating units
are given in Table '■'>. The duration of the tests was S hr. :
5 In-, at full loml. 2 lir. at three-quarter load and ]]■_, hr.
at one-half load. At half load the electrical energy was
absorbed in the lighting circuits normally supplied from
the generators. For the higher loads a water rheostal
was used. The coal consumption during tin' tests was
2.31 lh. per kw.-hr., as compared to 3.82 lb. obtained
PRINCIPAL EQUIPMENT OF KALAMAZOO MUNICIPAL PLANT
Size Use ( Iperating Conditions
310 hp Steam generators 200 lb. press., 150 deg. superheat Wi
Co.
Co. Equipment Kind Size Use Operating Conditions Maker
Boilers Vertical water-tube. . 310 hp Steam generators 200 lb. press., 150 deg. superheat Wickes Boiler Co
2 .stokers Jones underf I . .. Under boilers Controlled by Cole automatics The Under Feed Stoke
2 Vmerica
2 Superheaters . . Foster 104sq.ft Superheat steam Av. superheat, 150 deg Power Specialty Co.
1 Fan i housed 140 in. dia Draft for boiler furnace Driven by either of two 5x7-in. Troy eng The Under Feed Stoke, Co.
America
1 Heater Open 1500 hp Heat boiler feed water 750 lb. water per min. from 50 deg Warren Webster A Co
2 Pumps Duplex 7Jx4Jxl0-in. ... Boiler feed water 2011 lb. steam Henry R. Wnrthington
2 Turbines Hor. vel. tvpe, 4-stage 000 kw Main units 200 lb. press., 150 deg. superheat, 3600 r.p.m. General Electric Co.
8 Generators.. Three-phase, 4-wire.. BOO kw Main units 2300/4000-volt, 60-cycle, 3600 r.p.m. General Electric Co.
2 Exciters . Direct-current 7 kw. . . . . Excite main unit-. Mounted on shaft of main unit General Electric Co.
■ Wheeler Condenser & Engine
in;.' Co.
2 Condensers.
2 Pump-
Surface, 3 pass 1000 sq.ft Serve main unit Cooling water fn
and
No. 10.
Serve condensers Drj
Condenser circulating
' turliii
400(1 I
Pump- Centrifugal 7-in Condeni
water
switchboard, rectifiers, lamps and hue equipment.
The fuel cost per unit is one of the host indications of
plant economy. In the present instance this item ap-
proximates 1.0C. per kw.-hr. For the conditions (coal
costiii"; $2.70 per ton, only one unit running and at less
than half load, and nearly 20 per cent, of the coal used for
Kinking) this cost is low. It compares favorably with
plants of the same or greater capacity running at full
load, and indicates what may be expected of the present
plant when it is operated under favorable conditions.
Official Tests
That the plant is efficient is shown by the results of the
official tests made on May 15 and 16 of this year by rep-
resentatives of the consulting engineers and the city.
Table 2 gives the results of the boiler tests, each of 8-hr.
duration. An efficiency of Go.'' per cent, for boiler No. 1
'■ii by lli-hp. Tt
en by 25-hp. G.E. 440-v. motor, 900 i
Wheeler Condenser & Engine
ing Co
\\ heeler I '. >nden 5ei a i ngi
iliK Co
under the present unfavorable operating conditions. The
steam consumption at full load was found to he 15.3 lh.
per kw.-hr.. and when corrected to the guaranteed con-
ditions of 200 lb. steam piressure, 150 deg. superheat ami
'an absolute hack pressure of 2 in. of mercury, was ](i.'i lb.
The coal burned under the boilers had an average heal
value of 12,650 B.t.u. per lb., as fired. An average of
2.31 Hi. was required per kilowatt-hour, so that the total
heat expended under the boiler to generate a unit of elec-
trical energy was
2.31 X 12,650 29,221.5 B.t.u.
One kilowatt-hour is equal to 3412 B.t.u., so that the ther
mal efficiency of the generating plant is
'!ll"'
— 25-5=11.67 percent.
Fig. 10.
Switching Chamber at Rear of
Board
Fig. 11. Rectifiers in Basement and Equip-
ment Protecting Line
224
P 0 W E R
VoL 11. No.
For any steam plant of the type and capacity, this is as
high a "thermal efficiency as can be expected.
It is evident that the plant is uptodate in every re-
spect and can be operated at high efficiency. Jo reduce
the present unit cost, it is merely a question of obtaining
enough commercial service to properly load the plant.
E. W. Messany is chief engineer of the plant, and
Woodmansee & Davidson, of Chicago, were the consulting
engineers responsible for the design and construction of
the station.
By Frank Richaeds
A letter from a California correspondent asks why it
is that more has not been made of the Cummings system
of compressed-air power transmission. He says that from
the results which have been actually attained by the system
it could be advantageously employed in many places,
especially as, besides the economy of it. there is no danger
of fire or explosion, and it can be operated under water.
Notwithstanding that the return-air or two-pipe pump-
ing system, for raising water by the direct pressure of air,
is quite extensively and successfully employed in different
parts of the country, and that this system has been fully
described in various publications, the essential principles
of the Chiinmings system in it- entirety are not generally
well understood even where it happens to be known at all.
Patented a full generation ago. it seems to have been ex-
ploited mostly in California, and it may be worth while
to call the attention of power users to it again.
It is rather curious that the new departure which this
system represents— the use of higher pressures— is quite
iii line with the improvements in steam engines, in oil
engines, especially of the Diesel type, and in electrical
practice. It maybe claimed, however, that the two-pipe
the air into the atmosphere again, a constant intake pres-
sure of, say 100 lb. is maintained at the compressor. The
air is compressed to. say 200 lb., i- transmitted to and is
used in the motor at that pressure, and then is exhausted
and carried back to the compressor at a pressure of
100 lb., to be compressed and used again, and soon.
DIFFERENT PeESSDBE RANGES COMPARED
The accompanying diagrams, Figs. 1. 2, 3, are all
drawn to the -nine scale for equitable comparison, and
may be studied together, although each represents an op-
eration entirely distinct from and unrelated to the others:
that is. they are not successive stages of one operation.
In each case the same volume of air fills the cylinder at
the beginning of the compression, but the actual weights
aoo Pounds. Gage
Fig. 1. Am between 0 and 100 Lb. Gage
air system "goes them one better."' In the compound-
er the triple-expansion steam engine it seems to be the
last added portion of the'pressure which secures the econ-
omy, but the entire ran-.- of the pressure from the bottom
to the top lias all been retained, while the compressed-air
system here to be spoken of retains and uses only the
higher, and presumably more profitable, range of pressure.
The essential feature of the system is the constant
maintenance of a high pressure upon the air employed.
Instead of continually compressing fresh atmospheric
air up to. say 100 lb. gage, using it in the motor at that
rare, with or without expansion, and then exhausting
O F H
Fig. 2. An; between 100 and 200 Lb. Gage
or quantities of air are very different, only Fig. 1
beginning the compression with "free air," or air at at-
mospheric pressure.
Fie. 1 represents the adiabatic compression of a given
volume of air from atmospheric pressure, say 15 lb. to the
inch absolute, to a gage pressure of 1"" lb., or 115 lb. ab-
solute. Fig. '.' shows the compression of an equal volume
(not an equal weight) of air, but under an initial pres-
sure of 100 Hi. gage, to a delivery pressure of 200 lb. : and
in Fig. 3 an equal volume of air at 200 lb. is compressed
10 lb.
In each case the initial volume of air compressed is
represented by the area of the rectangle ABDCA. When
the air has been compressed to the gage pressure speci-
fied in each ease its volume is represented by the area
EBDFE, and this will be the volume assumed to be dis-
charged into the pipes and receiver. As we are speaking
now from the purely theoretical viewpoint, nothing is said
about clearance or other allowances made in practice.
It is well understood that the operation of compression
invariably increases the temperature of the air very much,
but this temperature it is impossible to maintain, and un-
less reheating is employed, the air is never used at the
high temperature at which it is delivered by the com-
pressor. As the air cools to normal temperature before
it is used, its volume being reduced proportionately, the
actual volume available for use is represented by the area
GBDEG, this being in Fig. 1 only about an eighth of the
initial volume, and not much more than one-half the
volume EBDFE. as delivered by the compressor.
The air delivered under either compression represented
may be said to have equal working value, volume for
volume, the available pressure being 100 lb. in either
case, the air in Fig. 1 at 100 lb. working against atmos-
phere only, the air in Fig. 2 at 200 lb. working against.
Fe
16, 1915
P ( ) W E Tt
225
a back pressure in the return pipe of 100 lb., and that
in Fig. 3 at 300 having a back pressure of 300 lb.
Tn compressing air from loo to 200 lb., as in Fig. 2.
tlic temperature of the air is not raised nearly as much as
in Pig. 1 and, consequently, the shrinkage in cooling
from volume EBDFE to volume (!lll>ll(l is proportion-
ately much less than in Fig. 1. The volume GBDHG here
O F H
Fig. 3. An; between 200 and 300 Lb. Gage
available for work is mure than one-half the initial vol-
ume ABDCA, or four times the volume available in Fig.
1. At the same time it is to he noted that the mean ef-
fective pressure in the compressor cylinder for the stroke,
which is the measure of the actual work of compression,
i- decidedly less than double that of Fig. 1. Getting fully
four times the available volume for less than double the
bower employed certainly looks like doubling the effi-
ciency by halving the relative cost of the compression.
In Fig. 3, compressing the air from 200 to 300 lb., the
heating of the air is still less and the consequent shrink-
age by cooling also is less. The available volume deliv-
ered, GBDFG, is five times the corresponding volume in
Fig. 1, while the mean effective pressure required for the
compression and delivery of the air is less than 2.1 times
as much, which seems to be decidedly more than doubling
the efficiency.
It has been assumed in each case above that the initial
air temperature is 60 deg. F. With the same increase of
KIO lb. in pressure the final temperatures will be 485, 163
and 121 deg., the rise of temperature being, respectively,
125. 103 and 61 deg. The enormous rise of tempera-
ture in compressing from atmospheric pressure has led
to the general adoption of two-stage compression, with
intercooling of the air. thereby gaining something in
economy, avoiding the overheating of the surfaces, the
burning of the lubricants and the danger of fires and ex-
plosions. With the heating that occurs in Figs. 2 and 3
there is no necessity fur employing the two-stage com-
pressor, and little possibility- of anv increased economy
through its employment.
The ratio of final ami initial absolute pressures is: In
Fig. 1, 7.666; in Fig. 2. 1.869; in Fig. 3. 1.465. The
ratio of the volume after cooling to 60 den'., or the volume
available for use, to the initial volume is: In Fig. 1,
0.1301 ; in Fig. 2, 0.535 and in Fig. 3, 0.6825. The rela-
tive costs of compression, as measured by the power used.
or the mean effective pressures fur the compression divided
by the volume after cooling, are: In Fie-. 1, n.<; ^_
0.1304 = 319; in Fig. 2, 78.88 -=- 0.535 = 147; and in
Fig. 3, 86.83 -=- 0.6825 = 127. Here the ratio of the cost
in Fig. 1 is 319 -=- 147 = 2.17, and of Fig. 1 to Fig. 3
it is 319 -^ 127 = 2.51.
It is understood that wherever this air is used — that
is, the air of Fig. 2 and Fig. 3 — whether for driving a
rock drill, for a steam pump or an air motor of any kind,
the air instead of being discharged into the atmosphere.
as. it would he from Fig. 1. is piped hack to the compres-
sor with only 100 lb. of its pressure use.]-, then, volume
for volume, the air used would be of the same power value
in either case, if nut \]^n\ expansively. As the available
volume delivered as shown in Fig. 2 i- four times that
in Fig. 1, a compressor of one-fourth the capacity, or, at
equal piston speeds, with a cylinder one-half the diame-
ter, will lie sufficienl fur the work. The maximum un-
balanced pressure against the piston would be no greater
i ie case than in the other, only it would be continued
for a longer or a shorter portion of the stroke. There
would be no additional strength required in any of the
working part- of the machine, excepl that the air cylinder
and connections would have to be strong enough for the
maximum pressure.
As the same air is used over and over again in the two-
pipe system, arrangements being provided for making up
leakage losses, there is no appreciable accumulation of
moisture and no possibility of freezing up, even if suffi-
ciently low temperatures should occur, which they do not.
At the same time more or less of the lubricant is carried
back and forth in the air and comes in contact with the
working surfaces. As the system is a closed one, being
entirely out of touch with the surrounding atmosphere and
not affected by the local pressure, it will work at one alti-
tude just as well as at another.
Why the System's Use Has Been Limited
Now as to why the system has not been more extensively
employed ; there is the fact to begin with that even yet
it is not. generally as well known and understood as it
should be. Then, evidently, it would not be likely to be
much used for intermittent work, such as the driving of
rock drills which are continually changing their location,
and where the maintenance of the return connection would
cost in time and trouble enough to cancel the prospective
advantage.
Apparently, the best employment of the system would
be for the driving of ordinary steam pumps where con-
stant pressure is usually required for practically the
entire stroke. The air of Fig. 2. at 200 lb. pressure and
100 lb. back pressure, or the air at the higher pressures
of Fie-. 3 does nut permit much profitable expansion in use.
When used for rotative purposes in an engine or motor,
the cutoff, as the compression diagram suggests, should
never occur earlier than three-quarter stroke, so that the
cutoff that may be accomplished by a good slide-valve
engine would be all that would be available in any ease.
In this respect the air in Fig. 1 would have some advan-
tage, as, to secure the greatest economy, it should be cut
off before half-stroke, and a certain saving would be ac-
complished by the expansion which would not lie possible
where the higher pressures were employed.
There is a necessity for the compressor supplying the
air and tl ngine or motor using the air to approximately
keep pace with each other, not necessarily stroke for
stroke, but so that, with the aid of suitable receiver ca-
pacity, the delivery and the return air pressures shall he
maintained as constant as possible. This implies that
the two working units of the system should be adapted
to each other in capacity and that an automatic pressure
governor should control the compressor.
326
P 0 W E R
Vol. 41, No. 7
>©to:
Bi C. V. Hull
SYNOPSIS — Description of the growth and de-
velopment of a novel power plant in which the gas
tractors under test are employed to furnish elec-
tricity for tlie factory.
One of the manufacturers of gas tractors has an un-
usual power plant. Power is furnished by the tractors
under tot. which are belted to 220-volt generators oper-
ated in parallel. A three-wire system with balancer set
is used for current distribution. The growth of this
plant has been rapid and the changes in its development
are interestmg.
to undergo a thorough test while furnishing power. As
there was but one generator, traitors were generally
changed during the noon hour. Shutdowns during shop
hours came quite often, but the lone was small at this
time and there was no great loss.
The increasing demand for power soon made it neces-
sary to install the second 110-yolt generator. The two-
wire system was continued, using the two generators in
parallel. This made it possible to test two traitors at
the same time and to change an engine without "dropping
the load." There were times, of course, when a temporary
heavy load caused a delay in changing engines.
The further demand for power was met by a third
Tractors Driving Generators
In the first plant power was furnished by a stationary
engine belted to the lineshaft. This worked nicely until
the buildings were enlarged and more machinery put in.
It was then decided to use the tractors under test to drive
110-volt generators. Accordingly, a small power house
was erected and one 110-volt generator installed. Some
of the machines in the shop were motor-equipped, while
others were belt-driven from lineshafts which were motor-
driven.
With this plan the tractors were worked out in the yard
and as soon a- they were lit went into the power house
generator. It was then decided to change the distribu-
tion, using a three-wire system with two of the genera-
tors running in parallel. When the load was not too
heavy only two of the three generators were run on the
three-wire system. This allowed the use of 110- and 220-
volt circuits at all times. The machines and lights were
>o connected that most of the 110-volt load was on
one side of the system ; heme the two machines in parallel
carried considerably more than half of the load.
In order that any of the three generators might be used
alone, double-throw switches were installed on the switch-
February 16, L915
i'n w e i;
227
board. By means "I' these switches, any two of the gen-
erators could lie operated in parallel, with the third one
running mi the opposite side of the three-wire system.
These generators were all compound-wound, but switches
were put on them so that the series windings of the fields
mighi be short-circuited when they were running in
parallel.
When one of these generators played out, a three-wire
machine was tried with indifferent success, and it was
| replaced with another 110-volt generator.
Usually, three dynamos were run during the Jay and
up to 8 p.m., after which only two generators were used.
In order to equalize the load after s p.m., one of the large
110-voH motors was fed by an individual circuit through
a double-pole double-throw switch. When the three dy-
namos were iii use this motor was fed from the two
in parallel on the positive side, and when only two gen-
Soon alter this, tun 200-amp. dynamos were also installed
in nil of the machine shop. These were arranged to
be driven by one engine by the use of a double pulley
on the first dynamo. They were also connected with
double-throw switches so that they could be used in par-
allel or to teed the three-wire system. This outfit wa- very
convenient, for small loads could he carried and it helped
to keep tin- voltage quite steady when used to feed the
three-wire system. After putting these machines in cir-
cuit all the dynamos were run with the shunt fields
onl .
Rapid increase in production, however, demanded more
. and it was derided that a new power house should
luill and that 220-volt generators, with a halancer
set, should l»
It was not possible to get the power house ready for
time, so machines Nbs. I. '.'. :;. 5 and 6 and two 220-
Fig. .. Diagram of Generator Wiring
erators were running the motor was usually switched to
the negative side to more nearly balance the load.
A single-pole double-throw switch was installed in
the machine shop, so that an incandescent light circuit
of some size could he switched as required. When this
switch S, Fig. '.'. was thrown to the right, the lights were
on a two-wire circuit connected to the two dynamos in
parallel. After 8 p.m. this switch was closed to the left,
ami the lights became a part of the three-wire system.
All are lamps were connected between the positive and
neutral wire- of the three-wire system, and the polarity of
their supply was not changed.
When the motor and lights were switched to t!i
ide the load was nearly balanced.
The next addition was a larger 110-volt dynamo, of
600-amp. capaoih (nol shown in Fig. 2) for use with
i 80-hp. tractors, although other tractors were used
with it as well.
volt dynamos. Nos. ; and s. were used for a considerable
period. It was always necessary to start tin.- 110-volt
units first and then cut in the 220-volt machines. The
double unit (5 and ii ) was always cut in "against itself"
(on opposite sides of the three-wire system) to prevent
any possibility of mistake with 1, 2 and 3. One of the
220-volt dynamos was set up in the yard under a tem-
porary sited, but whenever it rained the belt had to be
removed. A temporary switchboard was set up in the new
r house, and the other 220-volt machine was installed
there.
It was a rather mixed-up power plant during the period
just before the change-over. In the old power house there
were three 110-volt dynamos and in the yard one 220-
volt machine; in the mai bine shop were the big 110-volt
dynamo, one 220-volt dynamo and the two 110-volt ma-
chines, combined in one unit. Two 220-volt dyn
were next set up in the new power house with a tern-
328
P O W B B
Vol. 41. No. ?
porary switchboard. It was at this time that the tem-
porary balancer set described in Power, July 14, 1914.
was put iu service.
This plan of operation continued for some time, though
all the 220-volt generators were moved to the new power
house. When at last the other 220-volt machines ar-
rived and the new switchboard was set up, the 110-volt
dynamos were taken out of sen Lee, the two 110-volt. 200-
amp. machines being combined to make a balancer set.
In connection with generator Xo. 8 (Fig. 2) is shown
the permanent plan of wiring the 220-volt generators, of
which there are 10 at present. Each panel carries a
wattmeter, an ammeter, a voltmeter, a pilot light, a cir-
cuit-breaker, a rheostat, and a switch with fuse blocks.
The unit system in this plant gives great flexibility
and makes it possible to rush the testing of tractors dur-
ing busy times. These tractors range from 30 to 80 hp.
There is never any trouble regarding shift changes, for
the care of the tractors requires but little time and all fill-
ing is done with In-'- connected to pipe lines. The power
is cheaply developed, lor the tractor motors use fuel at
4c. per gallon. Of course, the greatest advantage is the
thorough testing of the tractors with little, if any, extra
All in all, the plant is very satisfactory and effi-
cient, though the noise is not pleasing to the man who
is accustomed to quiet-running Corliss engines.
'mitt Fuarfnisl
Electricity
By Herman- T>. Walker
c:
SYNOPSIS — -4 hydro-electric plant which forms
part of the Minidoka irrigation project in Idaho
sells its surplus power to the community at such
rates as to encourage the use of electricity for
heating and carious domestic purposes, a notable
example being the high school at Rupert.
There is not more than one thousand population in
each of the towns of Heyburn, Rupert and Burley, which
are the post offices and marketing centers for the farmers
on the Minidoka irrigation project, in the southern part
of Idaho ; but it is probable that few cities have adopted
electricity for so many purposes. To irrigate this part of
what used to be known as the Idaho Desert, the U. S. Rec-
lamation Service built a dam 600 ft. long and 50 ft.
high across the Snake River, forming an artificial lake
covering 26 square miles, and at this dam installed a
hydro-electric plant capable of producing 30,000 hp. The
Government carries this power to the towns and farms
scattered over the project, uses part to pump water to land
too high to be irrigated by gravity, and sells electricity to
farmers, settlers and distributing companies in the towns,
at rates as low as half a cent per kilowatt-hour.
The lowest rates are made for power and for heating
purposes. In the winter the power from the government
plant is not ueeded for pumping water, and the low rate-
offered have resulted in man}- of the houses and bu-
buildings being heated by electricity at a lower cost
than they could be heated with coal, which in this section
(Wyoming bituminous i is worth about $6.25 a ton.
Nearly every house and many of the barns on the Mini-
doka project are lighted by electricity, while the farmers"
wives do their cooking on electric ranges, and the farm-
ers run their pumps, grind-tones, cream separators, churns
and other farm machinery by electricity.
Last year the town of Rupert built a $50,000 high
school, and after figuring on costs, left oif the chimneys
and put in an electric heating plant. This schoolhouse
has probably the most modern equipment of any in the
United States, if not in the world. When the janitor
desires heat for the building he throws a switch instead
."veling coal, and when he leaves for the night he
throws out the switch instead of banking his fires. The
building is a three-story brick structure, designed to ac-
commodate 600 children, and the electrical installation
exceed- 435 kw. The heating plant has a connected ca-
pacity of about 400 kw. and consists of eleven units,
which makes it possible to regulate the heat with ease.
Each unit has a capacity of 36.5 kw., on 400 volts, and
consists of a stack of grid resistances.
The air is drawn in through a two-way damper which
permits it being taken from either inside or outdoors. A
fan with a capacity of 20.000 cu.ft. per min., located be-
yond the heaters, forces the hot air into the plenum cham-
ber, the floor of which is dropped a few inches below the
rest of the basement and is kept flooded with water. The
hot air is blown across the surface of this water before
entering the flues leading to the various rooms. About
tony gallons of water a day is evaporated and carried to
the rooms with the hot air. thus keeping the atmosphere
moist. Foul air is exhausted through ventilating shafts
leading to the roof.
An hour or two before school opens in the morning, the
janitor starts the fan, turns on as many units of the
electric heaters as he thinks necessary, and turns the air
damper to draw the air from inside the building into the
heating chamber. When the temperature has readied
about 70 F.. he turns the damper to draw the air from
outside. When the building is closed at night, the two-
way dampers are turned to exclude the outside air, the
heating units are all switched onto 220-volt transformer
taps, the fan is shut down and the air is allowed to cir-
culate by natural current during the night. This keeps
the temperature high enough to make the warming-up
process in the morning quick and easy. The heating
installation is designed to heat 20,000 cu.ft. of air per
min. from zero to 70 deg. F.. and has worked satisfac-
torily.
It ha- cost somewhat more for current than it would
have cost for coal to heat the school, but the school au-
thorities are convinced that the saving in the cost of in-
stallation, fireman's wages and depreciation has more
than made up the difference, and that the electric plant
under the existing conditions is actually more economical
in the long run than furnaces or boilers. Furthermore.
February 16, L915
l'OW E R
22'J
there is the greater elasticity of operation and the ease of
adjustment to meet varying weather conditions.
Power for this heating is supplied by the Government
at a Hat rate of $1 per kw. per month, based on the maxi-
mum demand for the month, with the stipulation that
the maximum demand for the season must be paid for at
least four months out of the year.
In addition to the electric heating, the school has a
complete domestic-science department with an equip-
ment of individual electric hot-plates Tor twenty pupils.
There is also a large electric range for baking and for
cooking the dishes supplied to the school cafeteria, where
the pupils are supplied with hot meals at cost. An elec-
tric water still which not only furnishes distilled water for
i he school, but also supplies the local drug store, where
the water is exchanged for the chemicals used in the
school laboratory, is another unusual equipment. Water
tor the toilets, the shower baths in the gymnasium, dish-
washing in the domestic-science room and for the labora-
tory, is heated by a :!-kw. circulating heater connected to
a 250-gal. hot-water tank. The machinery in the manual-
training room is operated from the 10-hp. variable-speed
motor which drives the ventilating fan. A 450-watt stere-
opticon is a part of the school equipment.
On this project, in summer, the government power
plant sends current to several points to pumping plants,
and pumps water for irrigating approximately 50,000
acres of farms, mostly alfalfa fields, the average pumping
lift being 66 feet.
The Government is required to allow a certain amount
of water to pass through the dam at .Minidoka, as there
are interests further down the stream which have prior
water rights. The water passed on for rise below is dropped
through 10-ft. penstocks and drives five main generating
units of the vertical type, each of 2000-hp. rated capacity
under a head of 46 ft., and two 180-hp. turbine-driven
exciters. The power is transmitted at 33,000 volts oyer
40 miles of transmission lines to the pumping stations
and transformer stations for town use. The average cost
of generating electricity and delivering it at the pumping
plants on the project, including 10 per cent, on the in-
vestment for depreciation and other items, has been about
0.6c. per kw.-hr. The cost of pumping water for irri-
gation has been about $1.40 per acre per season.
The rates charged to consumers on the project are:
FLAT-RATE LIGHTING
Pi i Month
For 20 incandescent 15-watt lamps SI 50
Per additional lamp 0 05
For 5 incandescent 15-60-watt lamps 1 . 50
Per additional lamp 0.25
Per light over 60 watts, for each 60 watts '.r fraction thereof. 0.2f
Per arc lamp, 700 watts, to In p.m J 51 1
Per arc lamp, 700 watts, all night 4.00
HEATING RATES
P, r device, per 1,000 waits, winter 1.50
IVr device, per 1,000 watts, summer 2 50
FLATIHON RATES
Per flatiron, 700 wails 0.50
METEIIKD LIGHT AND APPLIANCE RATES PER KW.-HR.
First 25 kw.-hr. in month 0 07
Fur 25-50 kw.-hr. in month 0.06J
For 50-100 kw.-hr. in month 0.06
In excess of 100 kw.-hr. in month 0.05§
POWF.i: RATES PER KW.-HR.
First 100 kw.-hr. in month 0 05
For 100-200 kw.-hr. in month (I 01
For 200-500 kw.-hr. in month 0.03
For 500-1000 kw.-hr. in month 0 015
For 1000-2000 kw.-hr. in month. . n mis
In, li ii ii 1-5000 kw.-hr. in month . . 0,007
Fir 5i -511.0111) kw -hr. iii mimili ii 0063
F..r 511,000-75.000 kw.-hr. in month 0.0000
For 75,000-100,000 kw.-hr. in month 0.0057
In excess 100,000 kw.-hr. in month. 0.0055
Mew lEMnsoim CommlbDiafaftnoira Pfi{f<=
The accompanying illustration shows the latest addi-
tion to the lone list, of Ellison gages. Hy the application
of a simple system of cross-connecting, the cover-type
dilferential draft gage, the Hue draft, the furnace draft
or the differential between the flue and the furnace,
indicating the variations of the air supply, can all be
indicated on a simple gage, over the full length of the
scale. The fittings are of brass and the tubing of copper.
Each connection is furnished with a piece of rubber tubing
for a V's-im pipe, serving as ,-t flexible joint for relieving
the gage from pipe strains and from shocks when the
pipe lines are accidentally struck with the fire tools. By
means of the elbows with locknuts, the combination can
be turned to the right, left, or up.
The tube at the right connects with the flue piping
on the boiler side of the damper, or with the last pass,
and the connection at the left with the furnace piping
in the usual manner. To indicate the flue draft the flue
cock is opened and the other two are closed, the cock
New Ellison Combination Differential Draft
Gage
at the left being pinned at quarter turn and so vented
that when closed, the zero end of tin gage is open to the
atmosphere.
To indicate the furnace draft the outside cocks are
closed and the middle cock opened, the economical range
of furnace draft being maintained between the pair of
pointers at the left, which are set as directed on the cover-
type differential draft gage.
To give a continuous indication of the variations in
the air supply, for which the gage is chiefly intended,
the outside cocks are opened and the middle one closed.
The reading is maintained between the second pair of
pointers, which are set to check with the furnace pointers,
the right being red, beyond which the liquid should not
pass except under excessive overloads. The object of
the pointers is to maintain the liquid as nearly as possible
to zero and still carry the load without producing CO.
To establish the liquid at zero all cocks are closed and
the plug over the chamber unscrewed until the vent in
the threaded portion stands out of the fitting.
Manifolds cau be furnished in place of the flue nipple,
for connection with various flue-gas passages, while a
pressure nipple can be furnished with an ashpit con-
nection, for indicating the blast or the differential between
the ashpit and the furnace. The scale of the gage is
divided into hundredths of an inch, and the movement
of the fluid is magnified ten or fifteen limes. The in-
ventor and maker of the gage is Lewis M. Ellison, 6233
Princeton Ave., Chicago, 111.
230
P 0 W E B
Vol. 41. No.
areett-C^iirreinitt Motto
11 to
By F. A. Awitt
SYNOPSIS — The effects of open field circuits and
how to locate the trouble; also the use of a water
rheostat as a substitute for a starting box.
The causes of direct-current motors failing to start as
described in Part 1 (Feb. 9. 1915) will not affect other
parts of the apparatus, such as causing the fuses to blow,
starting box or other parts of the machine to heat, etc.
A break in the field circuit will produce several differ-
ent effects, depending upon the winding, the setting of the
brushes, and whether or not the machine is loaded. If
series-wound it will not start, for the field winding is part
if the armature circuit. If shunt-wound and the brushes
are set at the neutral position the motor will not start,
but shifting the brushes off neutral will cause rotation
in the direction in which the brushes are shifted, provided
the machine is not loaded. A compound-wound machine
with the shunt field winding open will usually start
whether loaded or not, but unless heavily loaded it will
usually race. If the series field winding is open it will
have the same effect as in a series machine.
In the shunt field circuit a break may occur anywhere
between the first contact point on the starting resistance
around to where the field coils and armature leads connect
to the line wire, as indicated by the arrowheads in Fig. 1.
As the no-voltage release coil on the starting box is located
in an unprotected place, it is usually one of the chief
sources of open circuit in the shunt field circuit; there-
fore, it should be given first consideration.
Assume a condition as illustrated in Fig. 2 where the
no-voltage release coil is open at X. This interrupts the
shunt field circuit, but leaves the armature circuit com-
plete, and may cause any one of the effects enumerated.
Where an attempt is made to start a shunt- or compound-
wound motor with the shunt field circuit open, if it start-
it will run at high speed, the starting resistance will be-
come very hot. and if an attempt is made to cut out the
resistance the fuses will blow and the machine will spark
badly at the brushes and commutator.
A simple test for this defect is to disconnect the arma-
ture lead A on the starting box, close the switch, aud
bring the arm upon the first contact. If the field circuit
i- closed, a spark will occur when the arm is allowed to
drop back to the off position : if open, no spark will occur.
To locate the defect in the starting box, disconnect the
armature and field connections, close the switch and
bring the arm upon the first contact; then test with a
lamp, as at L and L' , Fig. 3. When the lamp is connected
to terminal A it will light, for the circuit is completed
through the starting resistance, as indicated. When con-
nected to terminal F it will not light, for the circuit is
open at X; the coil may then lie tested by connecting the
lamp first to one and then to the other terminal, as indi-
cted at a and /;. If the lamp lights at a aud not at b,
as in this case, it indicates that the circuit is open between
the two terminals of the coil, which may be removed and
again tested to make sure that the trouble has been prop-
erlv diagnosed.
It the defect cannot be located and repaired and the
coil has to be rewound, it does not necessarily mean that
the motor has to be shut down until the repairs have been
made. This difficulty can be temporarily overcome by
connecting terminals a and ft with a piece of wire. How-
ever, it will now be necessary to tie the starting arm or
remove the spring, to keep it in the running position.
Fiji- a more detailed explanation on- open circuits in field
coils see Power. Aug. 4, 1914.
Sometimes it is necessary that the starting box be taken
to the shop for repairs, or it may have been completely
burned out and a new one is required. In such cases, if a
duplicate starter is not at hand the motor must remain
shut down unless some substitute is provided for starting.
11 of the most convenient substitutes is a water rheostat.
This is made up of a common 10- or 12-quart pail, a wood
or pulp pail being preferable, as there is less danger of a
short-circuit. Two electrodes must be provided; one a
flat plate which rests on the bottom of the rheostat and
connects to one side of the line, the other any piece of
metal that is at hand and connects to the armature. The
pail is filled with water containing a handful of common
salt to increase its conductivity. This size of rheostat will
be sufficient for starting a 25- or 30-hp. 230-volt motor
under full load, or a 100- to 150-hp. motor under light
load.
Fig. 4 illustrates the proper method of connecting the
rheostat in circuit for starting a shunt motor. In making
the connection care should be taken to get the rheostat in
series with the armature only and the field connected
directly to the line, as shown. If the field is connected to
the armature wire leading to the movable element of the
rheostat, the motor will have a very weak torque at start-
ing. To start a motor with a water rheostat proceed as
follows :
See that electrode a, Fig. 4. is removed from the rheo-
stat ; then close the line switch and lower a slowly into the
pail. As soon as it is immersed in the liquid the machine
should start. Continue to lower a gradually until it
comes in contact with electrode b at the bottom of the
pail. To insure good contact while the machine is run-
ning, a single-pole switch S may be used to short-circuit
the rheostat after the machine has been brought up to
This short-circuiting switch must be open when
the line switch is closed to start the motor, or the fuses
will blow. If difficulty is experienced in getting the
motor to start properly through the rheostat, more salt
may be added.
The proper method of connecting a compound motor is
shown in Fig. 5, which is practically the same as for a
shunt machine. If a metal pail is used electrode b may
be dispensed with and the line wire connected directly to
the pail.
A short-circuit in one or more of the field coils of a
multipole machine will prevent it from attaining normal
speed. However, it will start with a good torque, but as
the speed increases sparking will occur at the commutator
and brushes and excessive current will be drawn from the
line: and by the time three or four points of the starting
February J G, 1915
P 0 \Y E R
231
resistance are cut out, conditions will become so bad as to
necessitate shutting the machine down, or the fuses will
blow.
A ground in two or more field coils if the system is in-
sulated, or a ground in one Held coil where the frame of
the machine and one side of the line are grounded, will
have practically the same effect as a short-circuit in one
of the field coils. A method of locating these defects
was described in Power, Sept. 1, 19] I.
Another defect which will prevent a motor from attain-
ing full speed is a short-circuit of a group of armature
roils. This will cause the machine to start with a jerky
will draw an excessive current from the line and blow the
fuses if the starting resistance is cut out.
To set the brushes on the neutral point when the ma-
chine is standing still, follow out the leads of the arma-
fcure coils located between the polepieces and set the
brushes on the segments to which these leads connect. The
proper position for the brushes is usually opposite the
center of the polepieces or opposite the center of the
space between them. In mosl modem machines it is op-
posite the center of the polepieces.
If the machine is compound-wound a short-circuit be-
tween the series and shunt field coils will have about the
Testing foe Break in Circuit and Starting Motor by Means of Water Rheostat
effort, and before the armature has accelerated very much
it will act as though heavily overloaded; and if an attempt
in made to cut out the starting resistance the fuses will
blow. The method of locating this defect was treated in
Power, Nov. 17, 1914.
Two grounds in the armature winding will have prac-
tically the same effect as short-circuiting a group) of coils.
One ground in the winding, combined with a ground on
the external circuit, will cause the fuses to blow.
If the brushes are shifted so that they are equidistant
between the neutral points, the machine will not start, but
same effect as a short-circuit in the field coils of a shunt
machine. This condition is illustrated in Fig. 6, where
a short-circuit is indicated at X between the shunt and
series field coils on polepiece B. On account of the low
resistance of the series field winding, the current through
the shunt field coils will take the path indicated by the
arrowheads, short-circuiting the shunt field coils on pole-
pieces V and I) and part of the coil on />'.
A quick test can be made for this defect, as shown in
Pig. 7. Open the connection between the series and shunt
fields at the motor and the armature connection A at the
232
P 0 W B B
Vol. 11. Xo. r
starting box. Connect a test lamp in the shunt fie' 1
euit a/ indicated, close the switch and bring the start-
ing-box arm upon the first contact. If the lamp lights
it denotes a short-circuit between the series and shunt
fields, as shown by the arrowheads. The defective coil
may be located by opening the connections between
the field poles and then testing between the series and
shunt coils on each polepiece with a lamp or volt;
In locating trouble never forget to test the machine
and the controlling device for grounds, as a combination
of grounds on a motor and controller sometimes produces
-nine very puzzling and, at first thought, unaccountable
effect* which are easily explained after the trouble has
been located.
for
By Charles L. Hubbard
SYNOPSIS— A brief treatise on the selection of
boilers for isolated plants, together with the n
important matters to be considered in connection
with boiler design and operation.
Selection of a Boiler
Among the governing factors in the selection of a boiler
are the pressure to be carried, size and number of units,
available space, and cost. To these may be added details
of construction, relating especially to accessibility for in-
spection, cleaning and repairs.
When the boilers are furnished by builders of estab-
lished reputation, it is not usually necessary for the engi-
neer to prepare detailed drawings and specifications. Gen-
eral requirements as to pressure, amount of heating and
grate surface, and type of furnace and setting are fur-
nished the builder, from which he, in turn, prepares speci-
fications for the approval of the engineer and which are
submitted with his bid. This applies especially to water-
tube and patented boilers, of which there is a great va-
riety. In the case of tire-tube boilers of the horizontal
type, the engineer often furnishes specifications, particu-
larly where any departure from standard construction is
required.
The boilers most frequently used in isolated plants are
the horizontal return-tire-tube and the standard makes
of water-tube boilers. Vertical fire-tube, locomotive and
marine boilers are also used in special cases. In the mat-
ter of fuel consumption for a given capacity there is
little choice in the differeni types of equal grade, hence
adaptability and cost arc the governing features in mak-
ing a selection.
Return-tubular boilers are rarely used fur pressures
over 150 lb. or for sizes much above 125 lip., because
of the thickness of plate required, which in general should
not exceed % or % in., owing to its exposure to the hot-
test part of the fire. Within these limits they are an effi-
cient tvpe and are especially adapted to low basements.
Tlie first cost of a return-tubular boiler is somewhat Less
than a water-tube boiler, which is sometimes a deciding
factor.
For larger units and higher pressures some form of
water-tube boiler is usually selected. Boilers of this type
are also frequently employed in small- and medium-sized
plants on account of greater safety, and special designs
are constructed tor locations when' headroom is limited.
BOILEB (' LPACITY.
The capacity of a boiler is based upon the weight of
steam which it will furnish in a given time under speci-
fied conditions; the standard of measurement being the
',.. i- lit « I <li\ steam evaporated per hour from and at 212
deg. The performance of a boiler operating under other
conditions may be reduced to this standard by the use of a
table of "Factors of Evaporation,*' which may be found
in most handbooks. Table 1 gives the factors of evapora-
tion over a small range and in a condensed form merely
for present purposes.
TABLE 1. FACTORS OF EVAPORATION
Temper-
ature of
Feed
Gage Pressure in
Pounds
per Square Inch
Water.
Deg. F.
100
110
120
130
140
150
160
170
ISO
50
1.20S
1 210
1 212
1.214
1.215
1.217
1.218
220
1.221
60
1.198
1 200
1 2(12
1 . 2113
1 21'.-.
1.207
1 208
1.210
1 211
70
1.187
1.189
1.191
1.193
1.194
1.196
1.197
1.199
1 200
SO
1 177
1.179
1.181
1.183
1.184
1.186
1 ls7
1.189
1.190
90
1 1157
1.169
1.170
1 172
1.174
1.176
1 177
1.179
1 180
100
1.156
1.158
1.160
1.162
1.164
1.165
1 167
1.168
1.170
Example — A boiler supplied with feed water at a tem-
perature of TO deg. generates 4000 lb. of dry, saturated
steam per hour at a pressure of ISO lb. gage. What is it-
equivalent evaporation from and at 212 deg.?
The factor for the above conditions from Table 1 is 1.2.
hence the equivalent evaporation under standard condi-
tions is 4000 X 1-2 = 4800 lb. of steam per hour.
The heat required to evaporate one pound of water from
a temperature of 212 deg. into steam at atmospheric pres-
sure is 970.4 B.t.u.
One boiler horsepower represents the capacity to evap-
orate 34.5 lb. of water per hour from and at 212 deg.,
which process requires 970.4 X 34.5 = 33,479 B.t.u.
In practical work this is commonly taken as 33,000, which
gives results on the side of safety.
What is commonly known as heating surface includes
all the plates and tubes exposed to hot gases on one side
and water on the other. Surface coming above the water
line and exposed to hot gases on one side and steam on the
other is called superheating surface.
The effectiveness of the various heating surfaces de-
pends upon their location and character, but in all com-
putations relating to boiler capacity, it is customary to
assume a uniform value for the entire heating surface
which shall represent a fair average under ordinary work-
ing conditions.
For power work an evaporation of 3 to 3.5 lb. of water
per sq.ft. of heating surface per hour may be taken, which
34.5
rails Ecr
3
11.5 sq.ft. per hp. in the first case am
3 1 5
— '-- = 9.9 sq.ft. in the second.
3.0 '
Builders usually rate their boilers on a basis of 10 sq.ft.
of heating surface per hp. for water-tube boilers and 12
sq.ft. for return-tubular boilers, but as no uniform rule
February 16, 1915
I'd w E 1;
233
is followed in this respect, the engineer should always
specify the amount of heating surface required rather
than the horsepower. Some engineers call for a guaran-
teed evaporation under standard conditions as to feed-
water temperature, steam pressure and coal consumption.
In the case of return-tubular boilers, it is well to state
the diameter and number of tubes for a given diameter of
shell, as the efficiency is lowered by crowding them too
closely together. Table 2 gives tube data as recommended
by the Hartford Steam Boiler Inspection & Insurance
Co.
TABLE 2. TUBE DATA
Diameter of Shell, In. Diameter- of Tubes, In. Number of Tubes
Efficiency
The efficiency of a boiler plant is made up of the com-
bined efficiencies of the furnace and boiler and is ex-
pressed, by the ratio :
heat absorbed by water in boiler per lb. of coal, as fired
calorific value of one lb. of coal, as fired
When oil fuel is used or mechanical appliances are pro-
vided for feeding the coal or creating a draft, the heat
required per pound of fuel for this purpose must be de-
ducted from that delivered by the boiler in the form of
steam for useful purposes in order to obtain the net effi-
ciency. The heat absorbed by the water in the boiler per
pound of coal equals
9TU.4 X W X g X /
w
in which
W = Apparent weight of water evaporated, in
pounds per hour;
q = Quality of the steam;
/ = Factor of evaporation for the conditions of feed
temperature and steam pressure during the
test;
w = Weight of coal burned, in pounds per hour.
The calorific value of coal varies with the kind and the
locality from which it conies, and should be determined
in each particular case for accurate results. For approxi-
mate work, the following values may be used:
TABLE 3. CALORIFIC VALUE OF AMERICAN COALS.
Kind of Coal Calorific Value in B.T.U. per Pound
Anthracite ... 13,200
Semi-anthracite 13,800
Semi-bituminous 14,700
Eastern bituminous 13,600
Western bituminous 12,300
In general, the efficiency will run from 50 to 70 per
cent., averaging about GO per cent, in well designed and
carefully operated isolated plants of good size. This ap-
plies to boilers working under normal conditions. When
forced beyond the capacity for which they are designed,
the efficiency falls off somewhat, although not so much as
was formerly supposed.
Boiler Performance
This relates to the various results obtained in the prac-
tical operation of steam boilers, such as rates of combus-
tion and evaporation, coal per horsepower-hour, etc.
The weighl of coal burned pec square foot of grate per
hour depends principally upon the kind of fuel, the type
of furnace and the strength of draft. Table 4 gives about
the average for different grades of coal burned under
natural draft. These figures, however, may vary 2 or 3
lb. either way, according to local conditions.
TABLE 1. RATES OF COMBUSTION WITH NATURAL DRAFT
Pounds Burned per Sq.Ft.
Kind of Coal of Grate per Hour
Anthracite buokwheaf No. 1 9-12
Anthracite pea 12-15
Anthracite nut 14-18
Semi-anthracite, -.n. moil's. . 14—18
Semi-anthracite, run of mine 18-22
Semi-bituminous, screenings 18-24
Semi-bituminous, run of mine 18-24
Bituminous, slack 18-24
Bituminous, screenings 20-26
Bituminous, run of mine 20-28
With mechanical draft the rate of combustion may
be greatly increased if desired, but is not usually carried
much over 30 lb. in stationary plants of medium size.
With certain types of stokers, however, the best results
are obtained with small grate surfaces and high rates of
combustion, but for average practice with hand-fired fur-
naces, the figures given should be generally followed.
The rate of evaporation depends partly upon the grade
of fuel and partly upon the boiler and furnace efficiencies,
which in turn are influenced by the character and ar-
rangement of the heating surface and its relation to the
grate area. Table 5 gives the pounds of steam evaporated
per pound of coal for different calorific values and effi-
ciencies within the usual range in isolated plants.
TABLE 5. POUNDS OF STEAM FROM AND AT 212 DEC PER POUND
OF COAL
Calorific Value of Coal in
Combined Efficiency of B.T.U. per Pound
Boiler and Furnace 12,000 13,000 14,000 15,000
50 per cent 6.2 6.7 7.2 7.7
60 per cent 7.4 8.0 8.6 9.3
70 per cent 8.6 9.4 10.1 11.8
The pounds of coal per horsepower-hour is found by
dividing 34.5 by the rate of evajioration obtained in any
given case. Table <i lias been prepared for the same con-
ditions of boiler efficiency and calorific value of fuel as
Table 5 and gives the pounds of coal required per boiler
horsepower per hour.
TABLE 6. COAL CONSUMPTION PER BOILER HORSEPOWER-HOUR
Pounds of Coal per Boiler
Horsepower per Hour
Calorific Value of Coal in
Combine d Efficiencies of B.T.U. per Pound
Boiler and Furnace 12,000 13,000 14,000 15,000
50percent 5.6 5.2 4.8 4.5
60 per cent.. 4.7 4.3 4.0 3.7
70 per cent.... 4.0 3.7 3.4 3.2
Boiler < 'apacity for Power — All power requirements
should be reduced to indicated horsepower. This, multi-
plied by the water rate of the engine, reduced to an
equivalent evaporation from and at 212 deg. and divided
by 34.5, will give the boiler horsepower required. Ex-
pressed as a formula, this becomes
. . i.hp. XW.E. Xf
in which
bJip. = Boiler horsepower required;
ijip. = Indicated horsepower to be supplied;
W.R. = Water rate of the engine under given condi-
tions of feed-water temperature and steam
pressure ;
f = Factor of evaporation for given conditions.
Example — What boiler capacity will be necessary to
supply power for a factory requiring 500 i.hp. at the en-
234
POWER
Vol. 41, No. 7
gine? Power is to be furnished by a low-speed engine us-
Lng 20 lb. of steam per indicated horsepower per hour.
The average feed-water temperature is (iO deg. and the
steam pressure 100 11). gage. In this ease
i.hp. = 500;
W.R. = 20;
/= 1.198;
which, substituted in the formula, calls for
500 X 20 X 1.198
3X5
= 34? boiler horsepower
This gives simply the boiler power for supplying the en-
gine. If steam is required for other purposes, such as
the driving of pumps, heating, ventilating, etc., the ca-
pacity should be increased accordingly.
Boiler Capacity for Heating, Ventilation, etc. — The
general method employed in this ease is the same as above
described. All heating requirements are reduced to
pounds of steam per hour and the result divided by 34.5
to find the boiler horsepower.
Palnaft for EimgaEaees'SEag Purposes
By E. X. Pehi v
The writer had occasion recently to investigate the prin-
iples of paint making, because bis employers were not
satisfied with the result.- in the upkeep of painted surfaces
in their various power plants. The results of these inquir-
ies may be of interest to practical men.
There are many ways of making paints, but only a few
for good paint. There are also many ways of using paint,
but only a few for getting good results. Nothing goes
further toward improving the appearance of a power plant
than the judicious use of paint and varnish, and a man
need not be a highly trained painter to get fairly good
results if the underlying principles are known.
Protective coats may be divid 1 into three general
classes, viz., paints, varnishes and dips.
Paints consist of a body, which is to be the protective
coat, and the solvent in which the body is dissolved. The
solvent in some paints evaporates and leaves the body, in
others, it oxidizes and hardens with the body. In addi-
tion to these two ingredients, it is customary to add color-
ing matter, unless the body is already of the color re-
quired.
Varnishes consist of a body and solvent, and are used
to give a glazed finish, impervious to the elements. Var-
nishes are sometimes used as fillers, prior to the appli-
cation of paint ; again, they are used as a protection to the
paint, particularly if the paint is of an expensive and
highly ornamental character. Dirt may be washed from
varnish, whereas it sticks more or less to paint. Varnishes
may be colorless and transparent, or may be stained to any
desired color.
Dips are protective coatings into which articles may
be dipped, after which the coating is harde 1 to the
desired texture by cooling, baking in an oven or by
further dipping in another compound. Such coatings
include lacquer for brass, east iron, copper or wooden
pipes, etc.
Well known combinations for paint are white lead and
linseed oil and coloring matter, kerosene or gasoline and
lampblack, or linseed oil and lampblack.
Without doubt, there is no paint known that equals
pure white lead and boiled linseed oil for general pro-
tection. For white coats, it may be used without other
ingredients; for any other color, the pigment may be
procured at any paint shop. It is almost impossible to
get contract work done with pure white lead and pure
boiled linseed oil ; but this is the only way to have high-
grade work done. The writer has had to go to the greatest
extremes, with inspectors, chemical tests, etc., in order I
to compel contractors to use pure white lead and linseed '
oil. because of their high cost. The usual substitute is
zinc, and even this is often mixed with chalk or lime.
Red lead is an excellent protection for steel work; it
does not show the dirt and is much cheaper than white
lead.
Cheaper paints are made with asphaltic and tar prod-
ucts dissolved in gasoline, distillate, benzine, benzol, lin-
seed oil or kerosene.
Varm>he-~ consist mostly of rosins or tree gums dis-
solved in turpentine, alcohol, gasoline or boiled linseed
oil. The solvent then evaporates (known in this ease as a
spirit varnish) or hardens by oxidation (known as an oil
varnish). Among the cheaper varnishes are shellac, in-
side finish, etc. The more expensive varnishes are those
intended to endure stress of weather, like automobile
finish, etc. The pyroxylin or celluloid varnishes are made
from cellulose. The celluloid is dissolved in wood alco-
hol or in amyl acetate (banana oil), and may then be
mixed with coloring matter or heavier bodies, such as a
solution of asphaltum in gasoline. It then imparts a
high, glossy finish. It has been found, however, that the
pyroxylin varnishes do not withstand the elements and are
therefore suitable for inside work only.
The pyroxylin varnishes are suitable for finishing
and protecting metal surfaces, provided the metal is
not highly heated. They also prevent oxidation, and pre-
serve highly polished surfaces. A fine grade of pyroxylin
varnish may be made by dissolving moving-picture films
in wood alcohol. The film can be secured from any large
film exchange, as they always have quantities of worn-out
films on hand, which are merely burned up as so much
waste. A thousand feet of film, unwound and stuffed
into a ten-gallon drum, may be covered with wood alcohol
and the drum closed. It should be left for a week, and the
drum turned over every day. Then the liquid may be
drawn off ami will he found to be a good grade of var-
nish. The drum may be filled again, as the film will last
for months. The emulsion settles to the bottom as a sort
of mud. and one must Ite careful to decant the liquid
so as to leave the settlings in the barrel.
The varnish is ideal for glossy, metallic surfaces, par-
ticularly those that tarnish, such as brass-work, metallic
paint, copper pipes, etc.
The metallic paints consist merely of finely divided
metal mixed with some oil or body which will cement
them together and to the surface, and then the liquid
portion will either oxidize or evaporate. The metals con-
sist of gold, silver, bronze, brass, copper, aluminum, iron.
and sometimes zinc. These paints must not be confused
with ordinary paints, which are compounds, such as lead
oxide (white lead; red lead is another lead oxide), white
zinc (zinc oxide) or copper ship paint, which is copper
sulphate as a rule. The finely divided metals which go
to make metallic paints are secured partly by grinding.
partly by el» trolysis, and others are hvproducts of some
other process or industry. The cheaper gilt paints are,
of course, imitations, but the more expensive ones are
February 16, 1915
powe i:
235
pure gold leaf. The leaf is so very thin as to be reason-
ably cheap, since it takes thousands of them to make a
pile one inch high.
Dips are very important to the engineer, because they
are the principal method of protecting pipe, brasswork,
etc. Most dips are applied hot. Pipe dips are mostly
black, and must withstand the action of water, air,
weather, soil and heat. The coating must he hard and
glossy, but must not chip or crack, nor run or flow when
subjected to moderate heat. Such results may he obtained
with certain grades of coal-tar products, also asphaltum.
The coal-tar products are affected more easily by heat
than the asphaltum, kit it is important to get the proper
grade of asphaltum. Probably the mosl satisfactory is
a medium grade of air-blown stock of such hardness as
will lie determined after a few experiments. This asphalt
should he dissolved in boiled linseed oil in a \al over a
fire until the mixture contains two parts of molten as-
phaltum to chic of linseed oil. Care must lie taken not
to get the mixture too hot, as the asphaltum will he brittle
if burned. A lair dip is obtained with only 10 per cent,
of linseed oil, hut the coaling is more likely to chip.
Lacquer lor brass work is made in numerous ways, hut
a fair coating can he obtained by dipping in a hot mixture
of pure linseed oil and pure white rosin melted together.
Care mus! be taken that the bath does not take fire.
Tlhe F^.F€lhs\se ©f Coal
l!v Moiai.vx B. Smith
SYNOPSIS — Some factors which ought to be
considered by the consumer when purchasing coal.
In connection with the purchase of coal two questions
arise, both of which may seem odd but which neverthe-
less bring forward intensely practical answers. The
first is. why does the consumer purchase coal? and the'
second, how does the consumer purchase coal? The
first question may be answered by the simple statement
that the coal is bought for heating purposes. This answer
is ready and straight to the point; but how about the
second question — can this be answered as readily as the
first? Unless the purchaser has been through the mill
thoroughly he will state that he buys coal from his dealer
at so much per ton, plus freight charges, and then puts
it in storage in field or bunkers, or perhaps burns it
at once in the furnaces.
It is worth while to consider the answer to the second
question. There is more involved in the purchase than
mere tonnage. The purchaser himself admits that it is
heating value which he desires. Therefore, he should
look for heating value per ton of coal bought and also
for nonheating properties in the coal.
Stop to consider, then, some of the factors to which
tlio consumer ought to give attention when purchasing
coal for Ins plant. In the first place, he is forced by
current practice to buy "tons of coal," regardless of
the true value to him, unless he is in a position to insist
upon "heating value per ton of coal."
What does this mean to the consumer? It means
that he is paying for mere weight of coal, for freight
on mere tons, for handling at the plant of mere tons,
for crushing mere weight, for storage of weight only, for
burning weight only and for handling ashes — all based
upon mere avoirdupois rather than upon heat value. Is
this common sense or good judgment? Hardly.
Supposing that he is in a position to insist upon heat-
ing value in every ton of coal which he purchases, and
to make his insistence strong by means of the proper
tests on all coal received at the plant. What then ? The
purchase of coal then becomes a matter, not of mere tons,
but of heat units per ton or per pound, a measure of the
coal's real value.
When the purchaser has reached this position regarding
coal, lie can then go ahead and by comparative tests select,
the coal best suited to his plant equipment. That coal
which is by its characteristics best adapted to the con-
ditions of the plant and the load is the highest grade
u>able, regardless of cost.
It is customary to state the heat value of coal in terms
of heat units per unit of weight, generally stated as
British thermal units per pound (B.t.u. per lb.) based
on the sample dried at 105 deg. C. for one hour. Unless
the exact characteristics of the coal are known, a pound
of it may have diverse meanings to the buyer. To make
this clear, the accompanying diagram has been made to
illustrate graphically how "one pound of coal" may have
great significance when all costs and efficiency in the
plant are considered.
Assume the initial cost at the mines to he the same for
each of the five coals shown. How much of the total
cost is productive? Only that portion represented by
the heat content of the coal purchased. How much of
the total cost is loss? The difference between the total
cost and the productive cost. The content of fixed carbon
and volatile matter is a measure of the productive cost,
whereas the ash content is the nonproductive cost. Which
is wanted, heat value or ash ?
No. 1 coal is a purely hypothetical coal, not found in
nature, but shown here for the sake of comparison only.
Coals Nos. 2 to 5 are representative of coals on the market
and show a common range of characteristics. Which
of these coals will give the best results in cost and
efficiency in the plant, from mines to bunkers and
ultimately to the ash dump? Does storage value mean
anything when, through strikes at the mines or stoppage
of transportation by floods, the plant is threatened with
a shutdown ? If so, which of the four coals would it be
preferable to have the bunkers or field filled with in
such an emergency ?
The cost does not stop with the original price per ton
plus freight, for handling, crushing, storing charges on
the coal and also handling of the resultant ash must
still be covered. It is generally conceded that coal high
in ash and sulphur is harder on all handling apparatus
than a coal of lower ash and sulphur content. The costs
for upkeep of apparatus will then be in proportion to the
23G
P0WEI5
Vol. 41, So. 7
wear and tear upon such equipment. In the furnaces
evolution of heat is the desired output and will vary di-
rectly with the heat content of the coal used. The higher
the heat value, the greater the amount of heat liberated,
all other conditions being similar. Finally there are the
charges for handling the ashes produced. These costs
vary directly with the ash content of the original fuel
burned.
In general, it may be said that the higher the qual-
ity of coal which the plant will handle economically,
the lower will be the eosts and the greater the efficiency
of the plant. It is not necessary that the dealer be held
to a strict specification of properties of the coal purchased,
although it is wise for the purchaser to acquaint himself
with such characteristics and for his own satisfaction
NO. l.COAL
(-« TOTAL FREIGHT AND HANDLING PRODUCTIVE — - ----)
100 X COMBUSTIBLE
--STORAGE VALUE 100% •
TOTAL COST IS PRODUCTIVE
NO. 2. COAL
•TOTAL FREIGHT AND HANDLING -
PRODUCTIVE FREIGHT AND HANDLING
6% ASH
92% COMBUSTIBLE
ASHk— COMBUSTIBLE CONTENT-
STORAGE VALUE AND PRODUCTIVE COST
TOTAL COST PER POUND
rf
NO. 3 COAL
TOTAL FREIGHT AND HANDLING
-PRODUCTIVE FREIGHT AND HANDLING
16 XflSH 84 % COMBUSTIBLE
■t
COMBUSTIBLE CONTENT
-STORAGE VALUE AND PRODUCTIVE COST-
TOTAL COST PER POUND
NO 4 COAL
TOTAL FREIGHT AND HANDLING
PRODUCTIVE FREIGHT AND HANDLING-
14 % ASH 16 % COMBUSTIBLE
COMBUSTIBLE CONTENT
STORAGE VALUE AND PRODUCTIVE COST
-TOTAL COST PER POUND
NO. 5 COAL
-TOTAL FREIGHT AND HANDLING
(* -PRODUCTIVE FREIGHT AND HANDLING
32 %/LSH 68 % COMBUSTIBLE
ASH-
"t
COMBUSTIBLE CONTENT
STORAGE VALUE AND PRODUCTIVE COST-
TOTAL COST PER POUND
ONE POUND —
Diverse Meanings of One Pound of Coal to
Consumer
formulate a specified analysis. He will rind that daily
tests on all coal received at the plant, or possibly weekly
averages, will afford him valuable data, and if he sends
copies of all such tests to his dealer, he will find himself
possessed of powerful ammunition with which to con-
vince the dealer that it is to his interests, as well as those
of the purchaser, to furnish the coal desired. Such an
arrangement tends toward mutual satisfaction since it
places both parties to the contraci on an equitable footing.
The tests which should be made regularly are those
to determine the heat value per pound of coal as fired,
ash content as fired and percentage of sulphur. These
tests give all the required data. Other tests may be made,
often of value to the consumer, such as the determination
of fixed carbon and volatile matter. Moisture must al-
ways be determined in order to calculate the coal to the
condition "as fired" or net weight of coal burned. These
are simple tests, and the apparatus is not expensive when
the results are considered. By all means adopt the
oxygen-bomb type of calorimeter for determining the heat
value of coal. Other calorimeters are at best only ap-
proximate in their results, although cheaper in first cost.
The purpose has been to point out the real meaning
of "coal" to the purchaser and consumer and to emphasize
the fact that only by knowing the fuel can the user reach
that degree of standardization in his fuel purchase and
combustion which has been the real factor in producing
the high efficiency of the modern power plant. It is a
fact that uniform fuel means uniform and economical
operation in the plant.
Sssmofii© i%.gpf2ailIco>ia ana §Il®wvaEIl®
1 leer power
i found wun uv yer papers The uther da and i saw
whare a Hull lot uv ingineers had Eote leters ter yu, so
i thot ide skrible this wun ter let mi brother ingineers
no bout the perfeshun doun our Wa. ive bin folerin in-
gineerin fer nigh Onto 22 yere (not countin the tim i
hawled gravl fer pete swint).
ime runin a engin 6 foot by 11 foot not countin the
brase i had put agin the silinder hed what got kraked
wun da whil i wuz Out lookin at The cirkus go bi. i
haint ever mesured the boilr Yit but wil az sune az i kin
lioro a tape Lin.
mi bos cum clown the uther da an toled me he ud jest
got a Notis frum the antysmok kumitty (witch i gess is
sumthin lik the temprunce unyon) to kwit makin so
mutch smok Doun at his spok factry. The bos sed he
gesst he wud hav to git a nu ortymobil stokr lik the
Notis sed.
Now that jes maid me rile Up, caus i lai dame tu bein
the best stokr fierman Herebouts. i haint extry big, but
ime stoutern a hors. Why i shuveld 400 lb. uv bug dust
in mi furnis wun da in 3 minits by Bill jones watch, i
dident Ink ter se if It maid eny smok, but i dont bleve it
did, fer twuz on a munda i maid the rekard an the wi elder
Simpling, just acrost the wa allers Washes on munda
and she wud ov razed cane if eny sut got on her close.
The bos kin tri sum wun in mi plase if he wants ter,
butt he wil be Sory an wish i wuz back cuz i kno rite
whare ter hit the guvnr ter make er stop evry tim the
ingin runs Off.
A feller cum in next da and sed he wuz the smok in-
spektr an wuz backd up by the mayer. the mayer haint
no frend uv min and i wudent Vot fer him las spring
cuz wen he wuz tax inquizitr he stuk me 2$ fer a chocalet-
culerd dog thet i hed trid ter driv Off fer a yere.
The inspektr feller sed he gest if mi boilr bed mor draft
it wudent mak so mutch smoke, i jest up an toled him
he didnt no his biznes cuz i bed often notisd wen smokin
mi pipe thet the Harder i suckd the more smok i maid, an
it stans ter reson a boilr Wil du the saim. he tride
ter tel me ther wuz a patent furnis what burnd the smok
an i toled him ter quit foolin cuz yu kant burn nothin
what yu kant git hold uv. He went out alukin sad liek.
i ges tba ar tryin ter pla a jok on me lik tha did ter
the last pol Basin wen Old judkins sent me bout tu miels
ter boro old Skinners ski links. If eny smok feller cuius
roun tryin ter bothr yu, jest thro him out.
yurs t rally Hi Swope
February 16, 1!J15
POWER
2::r
iiiiiiiiiiiimmiiiiiii II i.
iiiiiiiiiiiiiiinniiiiiiiiiniiiiii
. iiiiiiiiiiiiiiiiiiliiilllilllill iiiiiiiiiimi1
Gr©©dl S]p©cSi!icaifta©iniS
A specification or written contract should be a bind-
ing agreement that will hold good in law, and should
also define or describe so clearly that no doubts can arise.
when examined in detail, as to the meaning, scope and in-
tention of the agreement. Simple, direct and comprehen-
sive language alone will fulfill these needs. Xo matter
how complex the idea, some way of expressing the mean-
ing that will be clear to all parties is always to be found.
Yet it is the rule, rather than the exception, on contract
jobs for owners, engineers, inspectors, contractors and
mechanics to be hindered one or more times by a dispute
over the interpretation of some clause of the specification.
At such times it seems as if the ideal contract will
never be written. Each of the interested parties is able
to show good reasons for his contradictory interpretation
of the meaning. The owner justifies his effort to get
the best class of service and material for the least possible
expenditure, and the contractor, on his side, strives to
make the contract call for the least material and labor.
These opposing interests of owner and contractor are the
reason for the binding character of the agreement, and
the frequent ambiguity of meaning may in many cases
be traced to over-anxiety on the part of the writer to pro-
duce a document binding in law.
At the same time these opposing interests call no less
for clear unambiguous specifications than for legal safe-
guards for the protection and control of both parties.
Probably the best way to obtain such specifications is to
have them written by some disinterested third party who
is thoroughly familiar with the work to be done, the legal
demands, and the necessity fur perfect clearness. An-
other method of obtaining clear specifications and one
which has been receiving considerable attention is the
use of a uniform standard specification. Where applicable,
this method appears to be best, the standard form hi
adapted from time to time to agree with an ever widen-
ing experience.
It i- the engineer's judgment that counts, not only
in the performance of his duties in the engine room, but
in his administrative position as the head of an important
department.
His vocation is unique in that there is no well de-
fined term by which to designate it. If it were only a
matter of keeping boilers and machinery in operation,
starting and stopping, and looking after details, he
might be called an attendant, but if he i< to be truly suc-
cessful he must have more than the ability to do these
things. lie must have mechanical ability as a workman,
as well. This part of his work savors of a trade. He must
also have a knowledge of mathematics, physics and
chemistry before his calling takes on the characteristics
of a profession.
Then there are the things learned by experience; they
are peculiarly the property of the engineer. They in-
crease his knowledge and better his judgment in his
routine work, and that is a strong point, hut his know-
Ledge cannot stop here. It must extend to the executive
end of his duties and covers what is now a very important
part, and what is fas! becoming more important — the
business part of his work. To know what is best in his
plant to get results, that is what the employer wants.
and it requires a knowledge of uptodate equipment of
apparatus, appliances and devices, as furnished by trade
papers, circulars and catalogs and by personal investiga-
tion, and finally, it requires good judgment in the selec-
tion of those best suited to the conditions of his own plant.
A man may have all this at his command, but the
"what" and "when" in the matter figure largely. He must
work in harmony with the powers that be. A proposition
that might not receive encouragement at one time might
be sought for at another. The management has other
things to look after besides the power end, and the engi-
neer must use good judgment in his relations therewith.
Knowledge and experience improve judgment, and they
are both valuable assets to the engineer.
JE.Ea§piraees=Hin\jg> Foliates aim Go^airte
D©c£si©ims
The doings of the civil courts are thought by many en-
gineers to he about as uninteresting as any human activ-
ity can be. That this is a mistake will be discovered by any-
one who will take the trouble to glance through a few
volumes of decisions handed d wi • the supreme court
of any state having a large indi =i . population. Scat-
tered through the pages of these pu ilications are many
absorbing "stories" of both human ; nd scientific interest,
and the engineer who has never made the acquaintance of
opinions of this kind will do well to look into the subject
the next time he is in a public library or within visiting
range of a courthouse.
Naturally, the chief engineering interest centers in those
decisions which bear most directly upon accidents, except
in the findings of the Federal courts, where patent deci-
sions of the most absorbing technical significance may be
found. By and large, the>e decisions contain clear-cut
statements of the circun stances surrounding accidents in
the plant and or tht fie d which are often instructive in
suggesting ways of avowing the recurrence of trouble,
and which almost invariably assign responsibility in a
way which appeals powerfully to men with the reasoning
powers of engineers. It is surprising how soon one can
acquire the knack of scanning decisions of this kind for
material of technical importance from the engineering or
operating standpoints, and the excellent indexes which
these volumes generally have are most helpful.
Without attempting to list the topics treated in the
findings of the higher courts, it may he noted that these
include explosions, short-circuits in electrical generating
MS
POWEB
Vol. 41, No. 7
equipment, accidents on transportation and distributing
systems, failures of material due to defective manufac-
ture, the results of negligence in dealing with high-ten-
sion conductors, omission of safeguards on and around
machinery, failure to live up to the terms of contracts,
oversights in the erection and use of structures, tools and
forms for concrete molding, the value of new ideas in
equipment design and arrangement, and a host of other
matters which make very interesting reading, entirely
apart from the discussions of legal problems which neces
sarily go with the setting forth of facts and the interpre-
tation of their relations to one another. Especially in the
patent cases is one likely to find engineering points of
note, since expert testimony is usually brought into the
proceedings and the analysis of equipment designs car-
ried to extraordinary lengths.
The study of court decisions bearing upon engineering
questions is well worth the while of men of technical
training and occupation, and it is a pity that so many en-
gineers fail to realize the interest and instructive value
of the material hidden away in such opinions. Court de-
cisions will never rank among the "best sellers," but no
greater mistake could be made than to assume that they
are too dry to be worth scanning except in cases with
which one has personal associations. If one does nothing
further we would advise at least the reading of the di-
gests of cases of engineering interest which appear from
time to time in our department, "Eecent Court De-
cisions."
m
Ain\giIl^2giiHt§| Hike Fl^iatl8© C®Eadli&ii©m\
It is always gratifying to the editors to know that
readers have made practical use of matter which has ap-
peared in Power's pages. Under the same heading as this
editorial, on page 239 is the report of a reader on his
plant, as examined according to the questions in the fore-
word, "A New Year's Letter," which appeared in the
issue of January nineteen.
Incidentally, Mr. Hawkins is to be complimented on
the excellent showing which his plant made. We are sat-
isfied, however, that it was not for the purpose of elicit-
ing praise for himself or his plant that he sent us this
report with his permission to print it, justifiable as may
be his pride in the condition found. Rather do we be-
lieve that he is sincere in hoping that the idea may be
of value to others who would take it as a suggestion to
measure their own plants, not so much to discover how
well they have done, but wherein they may make improve-
ments.
In his own case it would appear that Mr. Hawkins has
been frank in his criticism of things that are not all that
they might be, and it is in this direction that we feel he
and all who try the test will derive the most benefit. In
fact, it was our purpose in printing the New Year's let-
ter to have it bring to mind all of the points upon which
an examination of a plant is desirable. While most of
them would incur to any painstaking engineer, a few
might easily be overlooked.
The scheme of marking or grading the condition by
percentages for each question was rather original and has
its value to any individual, as it affords comparable fig-
ures. It would not, however, serve as a basis for compar-
ing different plants, at any rate not unless the marking
were done by the same person, on account of the personal
factor entering in. No two people would judge alike.
Further, as Mr. Hawkins pointed out. the average per-
centage of the plant as a whole is not fair while equal
weights are allowed to each question and answer. To
carry out that plan relative importance of one thing to
another should be taken into consideration. It is also
evident that two different plants could not be justly com-
pared without some modification of the marking system.
The scheme does have value, however, in comparing the
condition of the same plant from year to year.
We believe that good may come from a discussion of
the idea and will welcome suggestions for elaborating
or improving upon the method of plant analysis.
Soot lowers the heat-absorbing efficiency of boiler-
heating surfaces ! Soot obstructs the passage of the prod-
ucts of combustion! Soot is a direct cause of corrosion!
And soot is smoke! Altogether, soot is the undesirable
of the boiler plant, an enemy of efficiency that is always
present and cannot be entirely eliminated, but must be
limited if economy in steam generation is to be realized.
As a destroyer of boiler efficiency, soot is more potent
than would be five times the thickness of asbestos spread
over the heating surfaces. In obstructing the passage of
gases it not only reduces the area of free passage, but
the soot clinging to the heating surface has a marked
retarding effect on the flow of the gases in proximity to
the heating surfaces, thus further reducing the rate of
heat transfer to boiler contents. Corrosion of boiler tubes
and surfaces is accelerated by deposits of soot, either
through electrolytic action or the eating away of the metal
by the sulphur constituents that are present, to some ex-
tent, in all soot. Then soot contains, or is, practically
all the visible, wasteful and objectionable constituents
of smoke. Within the furnace, boiler and flues soot is
merely soot; issuing from the chimney it is black smoke.
Suppose that, as some claim, one thirty-second inch of
soot mi the heating surfaces produces as great a loss as
blowing out a pound of steam for every ten pounds gen-
erated. Steam escaping into a boiler room at any such
rate would soon make it impossible for the fireman to re-
main near his boiler and would be such an evident sign
of waste that it would not be countenanced in any plant,
no matter how slipshod its operation. Nevertheless, a
mean thickness of one thirty-second inch of soot may be
found on the heating surfaces of many a boiler — it will
frequently collect in ten hours' operation. Again, assume
that a three-sixteenth-inch coating would be as detri-
mental to efficient operation as throwing away sevei
pounds of steam for every ten pounds generated, which
if allowed to escape into the boiler room, would quickh
scald to death the boiler-room force or bring about their
asphyxiation. Three-sixteenths inch of soot is rarely fount!
clinging to all heating surfaces, it is true, but such ac
cumulation is not unknown in out of the way corner
of the boiler, corners that are difficult to cleanse of soot
Perfect combustion of fuel would be the only way
eliminating soot. This being impossible of realization,
every means of improving combustion musi be taken am'
(he heating surface of the boiler frequently cleaned.
Too great efforts to prevent soot accumulation cannot be
made, for it surely ami continually settles on every surface
that lies in the path of the products of combustion.
February 16, 1915 P 0 W E E
|ii in mi iiiiiiiiiniiiiiiiii illinium imiiiii iiiininnii miinfliimmiiiiiii i m m
239
■ _ !"
©mrespoimdleimci
* "' » »""»"« '« "> ™iiiiiimiiiii mini Ilium Hum I in. Ilnl mm lnlllll Hll rriiririiiiiiini iiiiiiiiiiiiiiiiiii.
One way to cut down Sunday work is to have packing
ready cut and prepared to lit each gland. It should
be kept in boxes labeled with the size and the rod it is
cut for'. It is also a good plan to keep the packing hooks
on a rack in the same locker, then with a good heavy
pair of gauntlet gloves an extra ring of packing can be
slipped in during the noon hour. When a job of this
kind is to be done in a limited time, it is most important
to have everything ready before the machine is shut down.
Then, just as soon as the machine is stopped, get busy.
The heavy gloves protect the hands, and with all the
tools laid out within reach and in order, the job does not
take long.
A. D. Williams.
Cleveland. Ohio.
As 1 read the "'New Year's Letter" on the first page
of the issue of Jan. 19, I mentally answered the questions
asked, as they applied to our own plant, and after finish-
ing the letter the question arose in my mind, "Assuming
the best practical operating conditions to be 100 per cent..
what percentage, as an average, will our plant show ?" The
result of this self examination was interesting, and the
method in which it was made may be of use to others de-
siring to make the same test. Each question was con-
sidered on its own merits, keeping in mind as a standard
the best practices as advocated in the columns of Powek
during the past year.
Per
Cent.
1. Are our boilers clean? Yes 9S
2. Is the brickwork in good condition, and are all
cracks and unnecessary openings air-tight? Some cracks
in setting 96
3. Is the feed-water heater clean and working effi-
ciently, and is the water as hot as possible? The heater
is clean, but not of an efficient type. Exhaust is also
used for heating the building, and hotter feed water
would mean more live steam for the building. Could be
improved in summer 94
4. In water-tube boilers do we know that the baffling
is tight and that the gases are not short-circuited
directly to the stack? Yes 100
5. Are we sure that all bio wolf valves are tight and
that we are not blowing down too much? Yes 100
6. Are our dampers working, and do we use them
instead of closing the front doors on hand-fired boilers,
allowing cold air to filter through the brickwork, etc.,
or on stoker-fired boilers allow the fires to burn down
too low? No. Dampers are not properly used. Draft
is controlled by speed of stoker engine and fan, and is
unsteady SO
7. Are we carrying a steady maximum steam pres-
sure? Yes 100
8. Are all our grates, gages, flue cleaners and other
boiler- and engine-room tools and auxiliaries kept in
proper condition? Yes 100
9. Have the soot and ashes been cleaned out of the
base of the stack and combustion chamber? Yes 100
10. Do we know that our draft is the maximum pos-
sible under the existing conditions? It is too high 9S
11. Are we using a minimum amount of labor to prop-
erly perform the work in both engine and boiler rooms?
Yes. 100
12. Are the engines operated as economically as pos-
sible under the existing conditions? Yes 100
13. Do the pistons leak? No 100
14. Do the valves leak; are they properly set? There
is no leakage, and they are properly set 100
15. Is there any undue loss of pressure between the
boiler and engine? No 100
IB Is there anv steam loss from leakage in steam
lines? Xo gx
IT. Is the back pressure on the exhaust a minimum?
Could be lower in winter, but would give no better
economy, as engines are not intended to operate on a
vacuum gg
IS. Are all steam traps in good condition, or are
valve seats cut, floats collapsed or other parts defective?
Holly drain system is used, with very few traps; these
are in good condition and do not leak 100
19. Are all exposed surfaces subjected to loss of heat
by radiation covered? Yes, except pipe flanges 94
20. Do we know that all valves on steam lines and
all drain valves are tight and in good condition? Yes. . 100
21. Are all drains from oil separators, heaters, piping,
etc., clear and in good order? Yes 100
22. Are we using the proper auxiliaries to keep the
feed-water temperature at a maximum, and are motor-
driven auxiliaries operated under a maximum efficiency?
In winter, yes. In summer we could do better with a
more efficient type of feed-water heater, as the exhaust
is wasted and the temperature of feed-water in summer
is low ga
23. Have we the maximum vacuum possible with the
present temperature of water, barometric head, and water
supply? No, a higher vacuum could be carried in winter,
but more live steam would be used. In summer engines
run noncondensing 96
24. Do we keep the maximum load factor on all appar-
atus in use? Yes, on boilers, but engines operate a
great deal of the time underloaded. Have one more unit
than is needed and smallest unit is too large for the light
load at night. Only one is used at a time 80
25. Do we try to keep down the cost of supplies such
as lamps, oil, waste, packing, etc.? Yes 100
26. Do we know that our apparatus and station light
and wiring are in safe condition? Yes loo
27. Have we fire extinguishers and fire hose on hand
and properly connected? Yes 100
2S. Have we taken all precautions to prevent accident
by protecting all openings by railings, inspecting ladders
to see that they are safe, looking after all weights or
other heavy parts that may be suspended from above,
seeing to it that all pulleys, blocks, tackle chains, and
other tools are in proper order? Yes 9S
29. Are there any oily or slippery places in or around
the plant, or any piping or apparatus in use that is
.showing signs of strain? No, except high pressure in
feed line due to leaking pump governor 9S
30. Are high-tension apparatus, switchboards and all
exposed wiring properly guarded and danger signs used
where necessary? All wiring is protected by guards ex-
cept front of generator switchboard, and wide .space
back of distribution switchboard is used for storage of
lamps, wire, etc 90
31. Have we prepared for extreme weather conditions
in the way of ice, floods, lightning, etc.? Y'es 100
32. Have we taken care of the effects of high wind
and rains on our stacks, windows, roofs, etc.? Yes,
except main sewer from building is too small and causes
water to back up through plumbing fixtures on basement
floors during very hard and long rains 95
33. Do we keep accurate records of the operation of
the power plant and other machinery? Yes, but could be
improved 9S
34. Is the operation of the plant harmonious, the men
satisfied with their work and with each other, and with
the salary received? Yes, as a rule 9S
35. What is the general appearance of the plant: is
it kept clean, with bright work polished, floors clean
and all machinery clean? Yes 100
Adding the percentages for each item and taking the
average, we get a general average of 97 per cent., or in
other words, the general condition of the plant taken as
a whole has a rating of 9"i per cent, of the best practical
operating conditions that could be obtained in a plant of
this character. The nature of the work is that of an
office-building plant. We have a greater engine capacity
than is required and could get along just as well with one
less engine. The other equipment is all required to pro-
vide continuous operation. The lowest percentage of any
part of the equipment is in the furnaces, which could be
improved by installing a better means of controlling the
draft and by operating the blower continuously at a uni-
form speed, with the dampers partly closed at times.
There are some other changes that could be made to im-
240
P 0 W E E
Vol. 41, No. :
prove the efficiency, but would require a change of the
equipment in use at present.
This test, if honestly made, is interesting, and of bene-
fit in check?ng the general condition of the plant at the
end of tli' jeax. If it were made at the beginning of
each year it would give the engineer an efficient means of
telling whether the condition of the plant was getting
worse or better, as compared with previous examinations.
It has the disadvantage that a low percentage in the
boiler efficiency would be more expensive than a low per-
centage in the condition of the fire extinguishers, for in-
stance, but would not show in the general average unless
the several percentages were multiplied by their relative
importance.
I would like to know what other engineers think of this
self examination, which I admit is not absolutely correct
from all points of view, and what they would suggest to
improve it.
J. C. Hawk in-.
Ilvattsville. Md.
=§ftesiina Asia Ejecftos3
In regard to the unsatisfactory ash ejector described
in the issue of Dec. 2"2, 1914, p. 889, I would suggest that
if Mr. Clark will advance his steam nozzle to about 1(1
in. beyond the intake of his ejector, or, in other words,
2 Live steam pipe
I m 'of 145 lb. gage pressure
2 Pipe nozzled 1o
l"af discharge
Xoxzle FOB Ash EjECTOB
beyond the bottom of the ash hopper, and use a 2-in.
steam pipe nozzled down to l in. at the discharge in-
stead of a bell nozzle, and entirely close the end of his
larger pipe where the steam pipe enters, he will undoubt-
edly eliminate his ejector troubles.
In a plant where I was once employed we had almost
the same trouble, and changed it to something like the
inclosed illustration, and the ejector worked very well;
but it did not have the capacity needed for the four boil-
ers, which it was intended for, so we made two of them
and the trouble was ended.
H. L. Burns.
Oran, Mo.
I think if E. II. Clark would change the plan of
piping a little and increase the size of the steam pipe
the ejector would probably be a success. In his arrange-
ment I believe the steam helped to clog the pipe instead
of clearing it.
In the arrangement shown in the accompanying illus-
tration, (he steam jet creates a suction in the pipe A,
which pulls the ashes from the hopper, and they have a
high velocity when they reach the nozzle which blows
them on through the pipe. If the end of the pipe were
not open the ashes fed into the hopper would clog up
I know of an arrangement similar to this one, which
is in successful operation, and I think it is worth a trial.
as it would only require a Y-iitting in the present line
Plan
Anotheb Steam Ash Ejectok
a few feet ahead of the hopper and a larger steam pipe
with a single nozzle — one made of brass I think is the best.
The pipe line must be air-tight back of the nozzle except
at the open end, as noted.
G. Clevexstixe.
Pottstown. Penn.
Motor Lnlsidl ©Eae TelPinaairasill
\\ here motors or generators may be required to oper-
ate in either direction, both the armature terminals and
the field terminals are brought to the outside of the frame
for convenience in connecting. Shunt- and compound-
wound machines may have four, three or two terminals
brought to the outside. Where there are four, all con-
nections are to be made outside, and where there are three,
Fio. ;!.
one armature terminal and one shunt-field terminal are
connected inside, as indicated in Fig. 1. This connection
may be found on generators, the rotative direction of]
which has been specified. Where there is but one pair of
leads issuing from the frame, it means that the arma-
ture terminals and field terminals have been paired
and connected inside the motor, as indicated in Fig. 2.
Such a connection is never found on machines as received
from the makers, because, in the case of a motor, it would
require starting with the shunt field short-circuited by
February 16, 1915
PO W K i;
241
the armature; and, in the case of a generator, there would
be no convenient way of cutting in the field rheostat.
The limit in terminal economy was reached in the case
of a series motor operating a line of shop shafting. The
motor apparently had but one terminal; that is, only one
terminal issued from it. This condition had passed un-
noticed until the motor developed an open circuit which
had to be located. The motor was supported by an iron
shelf bolted to the iron building, traversed by the car
tracks and, upon disassembling, it was found that one
armature terminal had been connected to one end of the
Beries Held and the other armature terminal was brought
out lor external connection, as indicated in Fig. 3. In-
stead of the other end of the series field being brought
to the outside of the motor, it was connected to one of
the iron tield shells with a bolt and the connection taped
over, so that it could not lie seen. The open circuit
was due to the bolt having loosened and burned off.
J. A. HORTON.
Schenectady, N. Y.
'0.
In the Nov. 10 issue, Christian L. Hern inquires for
a suitable gasket for ammonia-compressor valves. I have
hail satisfactory results with gaskets made from pure tin
or from solder, half tin and half lead. Make this up in
the shape of a cylinder by forming up sheet metal an
inch or so larger in diameter than the gasket and six
or eight inches long. Inside of this use a mandrel about
1/2 in. smaller than the gasket. After pouring, chuck
in a lathe, bore and turn to the inside and outside dia-
meters of the gasket and then cut off to the proper thick-
ness. These gaskets have always made tight and lasting
joints for me.
Perky Losh.
Muncie, Ind.
The article in the .Ian. Ill issue, page 81, under the
above heading, brings out a number of interesting points
in the proposed boiler code of the A. S. M. E. It would
appear that these specifications, formulated by the manu-
facturers of safety valves, represent the best modern
practice embodying the combined experience and judg-
ment of those who have had the best opportunities for
studying the subject. While in the main the specifications
cover the subject in an excellent manner, there are several
points which, looking at the matter from a practical
standpoint, seem a handicap to the code and impossible of
fulfillment.
Assuming that the code is adopted and placed before
the legislature of a state, the promoters of the hill will
have a hard enough row to hoe to convince steam users
and other taxpayers of the desirability of legislation along
these lines as a public safeguard. It will he hard to
convince legislators in states where boiler laws similar t<>
the proposed code are now in force that anything will be
gained by discarding the present rules in regard to safety
valves and adopting the code rules. Other states which
might be favorably disposed toward this legislation would
await the action of the states which now have boiler
rules and, undoubtedly, would act along the same lines
as the pioneers. It would seem, therefore, that in loading
the code with fine-spun theories and lofty ideals the
safety-valve manufacturers have not given full considera-
tion to the practical side of the matter.
In the proposed code the size of a pop safety valve
for a boiler is based on the discharge capacity of the
valve. To determine (his capacity it is necessary to take
into consideration the total weight, in pounds, of fuel
burned per hour at time of maximum forcing, the heat
of combustion in ll.t.u. per lb. of fuel used, diameter
of the valve scat in inches, the vertical lift of the valve
disk measured immediately after the sudden lift due to
the pop, and the absolute boiler pressure per sq.in., or
gage pressure plus 14.7 lb.
A study of these requirements suggests many interest-
ing questions which affect the practical application of
this rule. How can it be determined when a boiler is
h'ing forced to its maximum capacity? Take, for ex-
ample, a hand-fired return tubular boiler on which a good
fireman with high-grade fuel is having a struggle to
maintain steam pressure. Now, if an automatic stoker
were installed on this boiler, more work could be obtained
from it before the same conditions would obtain. It
might be that several types of stoker would be tried nut,
each doing a little more work than the one preceding it,
before the right one was found. In each case, however,
the boiler or. rather, the furnace would have reached its
maximum capacity and, undoubtedly, the safety valve
would have been changed each time. Take the case of a
locomotive, in which the maximum capacity is only at-
tained when the engine is being worked. In this case the
greater part of the steam goes through the engine and
the safety valves are never called upon to take care of
the maximum evaporation of the boiler.
The heat of combustion of the fuel would, of course,
he determined by calculations from a chemical analysis
or by burning a sample in a calorimeter. If fuel is
tested today there is no assurance that subsequent tests
would not show a higher value, possibly to such an extent
that a change of valves might be required to conform to
the code. A great many steam plants have no coal-storage
capacity, and the coal is delivered day by day as required,
and many an engineer can tell without a calorimeter
that the heating value of the coal varies load by load.
In the case of a number of paper mills in the Middle
West, the principal fuel is "hog feed," or wood chips.
The boilers arc equipped with stokers which are always
ready to go into service automatically if the supply of
wood fuel decreases and the steam pressure tends to fall.
In one of these plants they have six 90-in. by 20-ft.
tubular boilers, and burn about five tons of coal a week
in addition to the wood fuel. Now, under the code the
safety valves would have to be proportioned, not on the
normal conditions, but on the theory that the boilers
were being forced at all times to their maximum with
coal as fuel. Many similar instances could he cited where
it is frequently found necessary to make a quick change
in the nature of the fuel.
The vertical lift of a safety-valve disk can be deter-
mined by a laboratory test involving delicate registerine;
and recording instruments. If the valve lifts a certain
amount, expressed in thousandths of an inch, today, what
assurance is there that it would not lift a few thousandths
of an inch more or less tomorrow, making the test
valueless?
At the top of page 39 of the code, a table of values i<
242
P 0 W E B
Vol. 41, No. 7
given, which may be assumed as the heat of combustion
of various fuels. If it is fair to assume this value, win-
not assume a value for each of the other variants in the
rule or formula, which would bring us back very closely
to the rule now in use in Massachusetts and Ohio? This
could be modified, if necessary, by the addition of the
paragraph in the rules of Ontario and other Canadian
provinces which provides that, when considered necessary,
the safety valves shall lie tested under full steam and full
fires for at least fifteen minutes with feed water shul off
and stop valve closed: if the accumulation of pressure
exceeds 10 per cent, of the working pressure of the boiler,
a larger safety valve must be substituted.
By this means the whole purpose of a safety valve
would be fulfilled and steam users, inspectors, and boiler
manufacturers would have a reasonable idea as to where
they stood on the safety-valve proposition.
Geo. E. Perkins.
Brooklyn. X. Y.
BJessOlectledl <t© Clhmiag© Faeldl
In taking off some indicator diagrams from an engine
we had occasion to put on an additional load. For this
purpose it was decided to run a small turbine set as a
motor. The main generator and the turbine set had been
so arranged that they could be connected in parallel if
desired, and an adjustable resistance was inserted in the
Connections between the ifwo Machines
armature circuit of the turbine set at X to limit the flow
of current when starting as a motor.
When switch No. '.' was closed an.! the resistance grad-
ually cut out. the resulting current How was so [
that the belt driving the main generator began to slip:
finally, it came oil'. The trouble was at on e laid to a
short-circuit in the turbine-generator circuit running to
the switchboard. Testing out showed the circuit to be
live from shorts, and after carefully looking over the
field connections of the turbine set. it was found that the
series field connections A and B had not been reversed for
operation as a motor.
The turbine-generator had a large seri field effect.
When the switch was closed and the resista ice was being
cut out, the current, flowing through the :■ ries field in an
opposite direction, produced a differential action and
neutralized the flux produced by the shunt field. As the
torque is the product of the field strength and that of
the armature, and the starting torque required was large,
the armature revolved very slowly. Hence, the counter-
electromotive force was low and permitted abnormal cur-
rent through the armature.
After the necessary changes were made no more trouble
was had and the engine tests were made with excellent
results.
Carl E. Eismann
Rexford, X. Y.
V
ILsmcM of S^sacIhiB'oimistnni lira CfiaecM-
Referring to the article in the issue of Jan. 12, page}
IS. under the above caption, it appears that the final
arrangement, which gave satisfactory results, was to leave
fhe four heated vessels connected to a main return linl
with only one check valve in the same.
3/owoff*
Proposed Haxd-Regulated Retuuxs
As regards the Massachusetts rules, which propose
require a separate check valve in each return line for heat
ing boilers connected two or more in a battery and fired
independently, it would seem that there is no analogy
een this proposed method of connecting boilers and,
the boiler in question, which furnished four unfired ves-
sels with steam.
In tlie case where one check valve is used on the main
return line, if one boiler is furnishing most of the steam,
while the fire under the other is banked, the water will
tend to flow through the return connection away from the
boiler which does the work, due to the slightly higher
.-team pressure. The function of separate check valves in
each return line i< to prevent tin-. The illustration shows
boo the connections should be made. With separate cheeks
in each return line, the water level in the boilers will
varj with the rate at which each boiler is forced, but
would, however, be controlled by the stop valves shown,
similar to the ordinary feed valve, so that if the check
valves did not work in synchronism it would make no
matei tal difference, for the water level would be controlled
entirely by the stop valves.
A. W. MacNabb.
Newark, N. J.
| Regulating the water level by stop valves as suggestei
would require someone in constant attendance, which is
not often the case with small heating plants.— Editor.]
February 16, 1915
P UWEE
243
B^ecordl Sleepiimg' fiim ttJhe Power PJamft*
SYNOPSIS — The importance of keeping accurate
daily records and the necessity of analyzing and
comparing them. Losses which would otherwise
go by undetected are discovered and the sarin;/ in
the course of a year is well worth the trouble.
Occasionally one finds a plant in which fairly complete
Sally records are kept and a capable man in the capacity of
Supervising engineer to make daily comparisons of oper-
ation of the furnaces, boilers, engines, generators, etc., but it
is probably an exception to the rule, particularly in the
smaller or medium-sized plants.
It is usually difficult, and frequently impossible, for an en-
gineer to persuade his manager to furnish him with the nec-
essary instruments and devices to make daily tests on oper-
ating conditions, and the necessary printed forms on which
to record the data for purposes of comparison and for detect-
ing the location, or even the existence, of preventable losses.
Yet the writer's experience with several plants has proven
that the savings made in one month as a result of the daily
tests and records frequently will pay for all the additional ex-
penses incurred within a year.
In nearly all plants managed by the writer he has insisted
on installing scales to weigh all coal as used and the ashes
daily, a water meter in the boiler feed line to measure all
water fed to the boilers, a kilowatt-hour recording meter to
measure electrical output, and suitable printed forms on
which to record the daily records of pounds of water evapo-
rated per pound of fuel, pounds of refuse from furnaces and
its percentage to the total fuel, pounds of fuel consumed,
rate of combustion, electrical output, pounds of fuel per kilo-
watt-hour, boiler output in horsepower hours of operation,
steam pressure carried from recording- gages, and similar data
which local conditions would suggest.
These records should be as complete as the nature of the
plant justifies; some types of plant naturally require more
■ lata than others, but in all cases sufficient data should be re-
corded to make daily comparisons of value in detecting losses
which may arise within the course of a few hours.
From these daily records suppose it is noticed that the
boilers evaporated 6 lb. of water per pound of fuel today,
while yesterday 7 lb. was evaporated; there Is a cause for
this difference, and the right kind of a man will not be
satisfied until he finds it. It may be due to a new car of
fuel, the quality of which is not as good as the former car;
perhaps the firemen were "too busy" to scrape the boiler
flues. Show them how to be more systematic, so that they
will always have time for this work and show them con-
clusively that you know what is going on in the boiler room
and cannot be fooled. Perhaps the load was lighter — then
take the matter up with the works manager and try to per-
suade him to balance his operating conditions to better ad-
vantage. Some boiler plants are so located with relation to
adjoining buildings that when the wind is from certain di-
rections the draft is affected, materially reducing the furnace
efficiencies. Notice from the records if this applies to your
case; if so, estimate the losses during a month from this
cause and then figure out how long- it would take the pos-
sible savings to pay for an addition of 50 ft. to the stack.
Then put it up to the general manager. There is always a
cause for every effect; the records show the effect, and it is
up to you to locate the cause and remove it as soon as pos-
sible.
Suppose the records show the number of pounds of fuel per
kilowatt-hour to have been six yesterday and four for the
day before; why this difference? Assuming the load conditions
and the boiler evaporation to be the same for the two days,
there evidently has occurred a change in the engine economy.
This may be due to one or several things; get busy and find
the cause.
It is not always easy to locate the immediate cause of
these variable losses, but daily analysis of operating perform-
ances will soon make a man quick in running- down the
trouble and will train him to take the necessary steps to
prevent their recurrence.
The knowledge that someone is daily going- over the oper-
ating records also has a decided effect on the engineer and
•Prom a paper by S. J. H. White presented at the annual
convention of the Indiana Engineering Society in Indianapolis,
lml.. Jan. 21 to 23, 1915.
fireman. At first these men usually resent the idea of be-
ing so closely watched, but by taking them into your confi-
dence, showing them the various records, complimenting them
upon securing better results, and consulting with them in the
effort to locate undue losses, they soon learn and realize that
this watching is of personal benefit to themselves and adds to
their store of knowledge. Usually, there will be voluntary
competition between shifts and between neighboring plants
to see who can g-et the most work out of a pound of fuel.
Of course, the writer has found men who resorted to
tricks to fool him. One fireman thought that blowing off the
boilers at light-load periods and letting in fresh water would
raise the rate of evaporation. It did slightly, and sufficiently
to start an investigation of the steam consumption of the
engine, as at first it appeared that it was taking more steam
than ordinarily. The engineer, of course, was notified of an
apparent loss of economy in his engine, and after checking
the rate carefully he became busy in trying to solve the pe-
culiar problem of the boilers' apparently generating more
steam than the plant was consuming. He found the cause and
discharged the fireman.
Another fireman was complimented when his rate of evap-
oration showed an improvement. By permitting the safety
valve to open frequently he raised the rate of evaporation,
but wasted fuel in doing so. Two or three days' record were
sufficient to put a stop to this practice.
The writer believes in frequent testing for line-shafting
losses. The tests are simple and inexpensive, especially in
case the plant is group-driven by electric motors. The daily
hunting for preventable losses is less expensive than the
ignoring of them. The load conditions seriously affect the
efficiencies of furnaces, boilers, and practically all engines.
It is desirable to pay attention to this point and attempt to
persuade the works manager to better balance his production
departments. One hour or day the power plant may be
seriously overtaxed, while the next hour or day it may be
carrying a decided underload. Usually, these conditions can
be avoided or at least improved upon.
A few years ago the writer took charge, as supervising
engineer, of an isolated plant which was entirely too large
for the work required. The load factor at that time was
about 18 per cent, of the engine and generator rating, and as
a result the losses were large. The engine was a simple Cor-
liss, belted to an alternating-current generator, and the boil-
ers were of the regular horizontal return-tubular high-pres-
sure type. The engine was operated at 108 r.p.m., but an order
was issued immediately for the proper pulleys for the gen-
erator, engine and governor to drop the speed to 82 r.p.m.
The result was a saving of 25 per cent, in coal consump-
tion. The only apparent solution for better economy was
more load. The shop was fully equipped with men and ma-
chinery, so there was no chance for more load here. The rate
of evaporation of the boilers was approximately 3 lb. of wa-
ter per pound of coal. Evidently, then, there was a chance
for improvement in the boiler room.
Gas was used for heating the baking ovens in the japan-
ning department, and the writer designed and built in the
shop an electric oven. It was so successful that six more
were built within a short time. This electric-oven load was
just what was needed to bring the load factor up to 41.4 pet-
cent, of the plant rating, and gave the boilers more work to
do, with the result that the evaporation increased to 6.5 or 7
lb. of water per pound of fuel. As the rate of evaporation
more than doubled with this increased load, it required actu-
ally less fuel to operate the plant and saved between five and
six dollars for gas per day.
There was still a loss not located, and it was logical to ex-
pect it to be in the furnace. Each furnace had 30 sq.ft. of
grate area, and tests showed that the rate of evaporation
was highest, other things being equal, when from 18 to 20
lb. of screenings were consumed per square foot of grate pet-
hour; a decrease in this rate of combustion, or an increase,
lowered the rate of evaporation, the latter showing a greater
loss.
Previous tests on the boilers showed that their evap-
orative efficiency fell rapidly from half load to no load,
while the curve of evaporation from one-half to 1 Vt load was
fairly flat. As the load was sufficient to require in one boiler
a combustion rate of about 35 to 40 lb. of fuel per square foot
of grate, the furnace efficiency was low. If both boilers were
operated to gain in furnace efficiency, the boilers were so
underloaded that they showed poor efficiency. Evidently, it
was a question of increasing the height of the stack, using
forced draft, or adding to the grate area.
A higher stack or a suitable forced-draft system would
have increased the economical rate of combustion, but th« In-
244
POWE K
Vol. 41, No.
crease in grate area seemed worthy of trial, and new grates
having an area of 36 sq.ft. were installed in one furnace.
This resulted in some saving during the daytime, but at
night, when the load was light, the losses were greater than
with the smaller grate area. The net gain, however, was con-
siderable.
At this time the company was contemplating moving to
another city, so that the writer did not recommend a higher
stack, which, after all. was the proper solution of the prob-
lem, as it is in a great many plants.
The daily losses detected and removed by a careful survey
of the records amounted to over $1000 per year on coal
costs alone, with an output of approximately 231,000 kw.-hr.
This reduces to 4.3 mills per kw.-hr. and is about 31 per cent,
of the total cost of production, including fixed charges, or
about 70 per cent, of the cost per kilowatt-hour for fuel,
labor, oil and waste only. The cost per kilowatt-hour during
1913 in this plant, including fixed charges of 14 per cent, on
the investment, fuel, labor, oil and waste, was $0,014. In view
of the fact that the load factor was only 31.4 per cent, of
rating, the writer considers this an excellent record, and one
which it is possible to make only by the closest supervision.
The weighing of coal proved to be valuable in another way.
The management closed a contract for coal with a certain
dealer. The writer detected a decided difference in the
quality of the coal and a shortage of weight after the third
car had been shipped on this contract. He reported the
matter and made complaint, but the matter was not at-
tended to as it should have been. Inside of a short time
the company had been billed with 70,000 lb. of coal which it
had not received. In other words, the weights on the bills had
apparently been raised 10.000 lb. per car, and further, the
coal was not shipped from the mine specified in the contract.
The daily records showed this up clearly. Without them, how
much would have been lost on short weights alone in a year's
time, to say nothing of the losses resulting from the rate
of evaporation dropping from 6.5 to 4.5 lb.? The contract was
canceled, and coal was purchased elsewhere of a much better
quality on a square-deal basis.
The facts given show that it pays to keep records. Never
be satisfied with results which may seem good, but which may
possibly be improved upon. In all lines of work continual
digging is the only successful way to secure the best re-
sults.
(Q)U,T
.cojiimcF
By D. D. Ewing
While approximately one-half the states have passed laws
authorizing the creation of public-utilities commissions, many
of the commissions are as yet in the formative stage and have
not passed any regulations on watt-hour meter accuracy and
meter testing. The percentages of error allowed by the com-
missions of several states are:
Permissible Error,
State Per Cent. Remarks
f Meter must not creep
New York 4 ... on 110 per cent.
I voltage.
New Jersey \ { g* )
Connecticut 4
Maryland 4
Indiana 4
Massachusetts 5
Wisconsi n 4
Washington 4
The following requirements, abstracted from the rules of
the Wisconsin commission, have been widely copied in other
states:
(a) No electric meter which registers upon no load shall
be placed in service or allowed to remain in service.
(b) No electric meter shall be placed in service or allowed
to remain in service, which has an error of registration in
excess of 4 per cent, on light load, half load or full load.
Cc) Each service meter shall be tested at least once each
vear, the test to be made by comparing the meter while con-
nected in its place of service, with suitable standards on
light-load, half-load and full-load rate of operation.
(d) Each service meter shall be tested and adjusted for
accuracy at the time of its installation.
(e) A complete record shall be kept of all tests made on
electric meters.
(f) Each company supplving electrical energy on constant-
potential svstems shall adopt and maintain a standard average
value of voltage, as measured at any consumer's cutout, which
shall remain constant from day to day. and vary during any
one day by an amount not more than 6 per cent, of the
minimum value.
It is interesting to note, in this connection, that the per-
missible error in gas meters, as defined by the regulations
of most of the above named states, is only 2 per cent., despite
the fact that electrical quantities are capable of more precise
measurement than is the flow of gas.
The question may be asked: How near do the meters on
the market conform in accuracy to the requirements of the
regulations? Manufacturers of direct-current meters usually
claim that their meters will register within 2 per cent., plus
or minus, from 5 per cent, of full load to 50 per cent, over-
load, the meter being capable of carrying the overload con-
tinuously. Some makers place the lower load limit at 10 per
cent, instead of 5. The lower load limit with alternating-cur-
rent instruments varies from 2 to 5 per cent, of full load
among the different manufacturers, the accuracy and overload
limits being the same as for the direct-current meters.
The initial accuracy, or accuracy when new, of most mod-
ern meters is largely a matter of adjustment. In fact, by care-
ful adjustment a good meter may be made to give an initial
registration within 1 per cent., plus or minus, from 2 per cent,
load to 50 per cent, overload, and a registration within V4
•From a paper read before the Indiana Engineering Society
at Indianapolis, Jan. 21 to 23.
per cent, from 10 per cent, load to 50 per cent, overload. Such
very careful adjustment is hardly a commercial feasibility,
however, as it would make the first cost of the meter too high.
Moreover, the maintenance charges would be excessive if such
a high grade of adjustment were maintained.
Most types of meters are fairly accurate when new, but
permanency of calibration is one of the most important of
the features that distinguish the good meter from the poor
one. In the modern meter increase of friction is the factor
that most often affects the permanency of calibration. Also,
the variation of the meter friction from instant to instant
makes it difficult to secure consistent results in light-load
tests. The effect of increased meter friction is to make the
meter run slow. With a well designed and constructed meter,
it is the exception rather than the rule that the percentage
registration increases as the age of the meter increases.
While increased friction tends to make the meter run slower
at all loads, the effect is most marked at light loads.
Evidently, no power company would care to keep in opera-
tion a meter in which the friction had increased enough to
even slightly affect the full-load registration. With meters
of lower torque ratio than 200 to 1, the errors will be greater,
other things being equal. However, if a well designed and
constructed meter is properly installed, the friction does not
increase very rapidly.
A comparison of the rules above abstracted with the
operating characteristics of the meters leads one to believe
that in general the regulations cover the ground fairly well.
There are several points, however, that merit further dis-
cussion. Rule (d) is hardly specific enough and, as it stands,
is capable of broad interpretation. It does not specifically
state that the test is to be made either on the consumer's
premises, with his load or a load having similar character-
istics, or elsewhere under conditions approximately similar
to those on the consumer's premises, and be in service a year
before the error in calibration was discovered. In rules (b)
and (c) light load is not defined. If a meter is adjusted so
that it is registering within the limits of permissible error,
as fixed by the rule, at 10 per cent, load, the error at 2 or 3
per cent, load may be anywhere from 5 to 15 per cent.
The ruling that electric meters may have an allowable
error of plus or minus 4 per cent, does not seem consistent
with the 2 per cent, ruling for gas meters. It seems that
a ruling allowing the permissible error on 5 per cent, load to
be 6 per cent., and the error on half and full load to be 2 per
cent, would be much better. Such a ruling would protect the
consumer far more than does the straight 4 per cent., be-
cause with the latter all meters can be adjusted by the power
company to be approximately 4 per cent, fast at the higher
loads, because meters have a tendency to slow down with
age rather than to speed up. At the same time such a ruling
would not work any particular hardship on the public-service
companies because the light-load error passes the 6 per cent,
point long before the error at full load would pass the 2
per cent, limit. Also, some time would be saved in meter
testing, because the variable friction of the meter makes it
difficult to secure consistent results at light loads, and with
a wider range of permissible error at light load, meters would
not have to be tested so often.
February 16, 1915
POWEE
245
In conclusion, the writer believes the efficiency of the
mmission rules above abstracted would be increased if:
(1) They specifically stated that meter tests made on the
stomer's premises be made either on the customer's load or
load whose characteristics were known to be approximately
e same.
(2) Meter tests made elsewhere than on the customer's
emises should be made with the conditions of voltage and
wer factor as near like those existing on the customer's
emises as is practically possible.
(3) The light load should be defined as 5 per cent. load.
(4) The permissible errors should be taken as 6 per cent.
5 per cent, of full load and 2 per cent, at half and full
'*~~
rC*
ruin
t^.
■■—
'
-
—
_--
"■
~'
■0
til
^
„--
--
„.
,-■
--'
__M
HVH
iron*
By E. W. Weaver
The piston being the part first affected by the impulse of
the explosion, friction at this point decreases the efficiency
of the engine to a greater extent proportionately than at any
point farther on. Therefore, it is of prime importance that
its tit in the cylinder be the best obtainable and that it be
sufficiently free to allow for the necessary oil film and for
slight distortions under heat, yet close enough to prevent
"piston slap."
0.007
c 0.005 -
c
■fe
J? 0.001
I
g 0.003
<u
c 0.002
c
O 0.001
? 3 4 5 6
Diameter in Inches
Maximum, Ideal and Minimum Clearances
The problem is not like that of a solid plunger operating
in a cylinder of heavy body and under such conditions as to
insure an unchanging form and permit of copious lubrication.
Instead, it is that of a comparatively delicate piston work-
ing in a cylinder with walls as thin as the designer dares
make them and subject to extreme variations of temperature
at different points.
The ideal allowance will be considered apart from that of
manufacturing tolerances. Some engineers make the piston
0.001 in. small for each inch of diameter of the cylinder bore.
The writer prefers to allow from 0.002 to 0.0025 in. for each
inch of diameter above 2 in. This is shown in the chart.
As it is impossible to manufacture commercially parts that
are all exactly alike, due allowance must be made for varia-
tions. The engine builder has the choice of three methods —
(1) putting limits on the drawings and holding the inspection
to such a point that any piston will work in any cylinder;
(2) sorting and assembling the cylinders and pistons accord-
ing to size; (3) making all the pistons a closer fit than they
are expected to run at and lapping them to the proper fit, each
in its own cylinder.
Only the first method, that of strictly interchangeable pro-
duction, will be considered. The fixing of the limits to which
the work is to be done is very important, as it directly affects
the cost of the product. The drawing should represent what
the engineer expects, what the shop will guarantee and what
the company is willing to pay for.
Considering the cylinder first, a permissible variation be-
tween maximum and minimum size of 0.0015 in. is absolutely
necessary — 0.002 in. is the ordinary allowance — and the cylin-
•From a paper presented at the annual meeting of the
Society of Automobile Engineers, New York, Jan. 6 and 7.
der must not be tapered or "out of round" to exceed the
given allowance. A variation of 0.001 in. between the maxi-
mum and minimum size for the piston is the usual allowance.
If wider limits are given, more care must be exercised in
assembling or the quality of the engine will be lowered.
As the head of the piston is exposed to the intense heat
of the explosion, it must be made considerably smaller than
the skirt. The amount is usually fixed at from 0.002 to 0.0025
in. smaller for each inch in diameter.
The fit of the piston ring in the groove is another import-
ant point. The ring must be loose enough to operate freely
and close enough to prevent gas from leaking past. The
minimum safe allowance is 0.0005 in., and the tolerances on
both ring and groove must be given in such a way that this
allowance is not diminished. The closest limit that is being
worked to commercially is 0.0005 in. variation between the
minimum and maximum of both ring and groove width. This
would be expressed on the drawing as "o'Ugs" for tne width
of the groove and "o Us" for tne rinB- Allowance must also
be made between the ends of the piston ring for expansion
under heat. From 0.006 to 0.015 in. is the usual amount.
The fit of the pin in the piston is the final point at which
great care must be exercised, the proper allowance being
0.001 in. The hole in the piston, being reamed or broached,
can be held from exact size to 0.0005 in. under size. In the
case of a 1-in. piston pin, the hole in the piston would be
dimensioned from 1.000 to 0.9995 in., while the pin would be
given as 0.9990 to 0.99S5 in., thus insuring a minimum allow-
ance of 0.0005 in. and a maximum allowance of 0.0015 in.
It should be stated in conclusion that the suggestions in
this paper apply particularly to water-cooled engines.
The world-wide activity in the search for petroleum de-
posits of commercial importance which characterized the year
1913 continued unabated during the early part of 1914. During
the later part of the year, development in proved areas was
greatly curtailed and exploration work postponed on account
of the European war and the enormous overproduction of oil
in the United States and Mexico.
The following paragraphs are from a statement by John
D. Northrop, of the United States Geological Survey, discuss-
ing the petroleum developments in foreign countries in 1914,
which has just been made public by the Survey.
NORTH AMERICA
CANADA — The. productive fields of Ontario and New
Brunswick continued to furnish the declining petroleum out-
put of the Dominion. Though considerable effort was made
to extend the boundaries of the productive areas, new pro-
duction sufficient to offset the decline in older wells was ob-
tained only in a few places. Good gas wells continue to be
found in the Tilbury district, Ontario, but attempts to retard
the declining oil output were unsuccessful.
MEXICO — Early in 1914 field operations in the oil districts
of Mexico were very active — more so in the northern fields
at Panuco and Topila than in. the southern fields, where the
work was interrupted by the belligerent political factions.
The bringing in of an enormous gusher by the Corona Oil
Co. (Dutch-Shell) at Panuco on Jan. 11 became the signal for
a pronounced increase of work in the northern fields, where,
as in the southern fields, the lack of adequate storage facili-
ties tended to hamper developments greatly. Work in all
districts was abruptly curtailed and in many places terminated
in April. Late in the year the rosumpton of local oil consump-
tion by the Mexican railroads and mining industries served
to revive activity to some extent.
Of more than passing interest was the fire which raged
about the famous Potrero del Llano No. 4 well of the Mexican
Eagle Oil Co., during the latter part of the year. Seepages
of oil escaping to the surface after the well had been capped
were ignited by lightning on Aug. 14, and up to the close of
the year the fire, though confined to a small area, had defied
all efforts to extinguish it.
SOUTH AMERICA
COLOMBIA — The discovery of petroleum and natural gas
at Tubara, near the important Caribbean seaport of Barran-
quilla, indicates the development of an important oil field in
close proximity to the Panama Canal.
BOLIVIA — Geologic investigations have shown the presence
of a considerable area of prospective oil land, south of Sucre,
and the reported acquisition of petroleum concessions in that
region indicates that the area will be thoroughly tested.
2 it
POWE E
Vol. 41, No.
LeEsi&nv© <G<o>@fts of Sft©®.ffim airadl
BH^ dl s=© => IE- II © etei ©
The question of relative efficiency and cost of installation
and operation of hydro-electric and steam plants brought out
some marked differences of opinion among experts at the
recent hearings before the U. S. Senate committee while the
Ferris water-power bill was under consideration.
Paul M. Lincoln, president of the American Institute of
Electrical Engineers, advised that increased efficiency and
lower unit cost of installation in the steam plant within
recent years altered the hydro-electric situation materially,
and that the value of potential water powers had perhaps
been overrated because of failure to consider this fact.
"There is much public misconception," Mr. Lincoln declared,
"as to the profits of hydro-electric companies, which are
generally considered as very large because of the idea that
water power costs nothing and the cost of operation is small,
while the company's income is large." "On the contrary,"
he stated, "the interest, sinking-fund charges, taxes and
depreciation on the larger initial cost of "water-power instal-
lations are comparable with the cost of coal in a steam
station. The invested capital in a water-power plant is so
much greater than the public realizes that with interest
charges at not more than 5 or 6 per cent., in a majority of
cases from 70 to SO per cent, of a water-power company's
Income is absorbed. This return to capital is not profit."
"When the cost of installation for water-power develop-
ment amounts to $100 per kilowatt capacity against an instal-
lation cost of $50 per horsepower for steam," declared Mr.
Lincoln, "it is always a serious question whether the steam
plant is not likely to be more economical and profitable."
Several other electrical engineers testified along the same
lines, urging the discrepancy between steam- and water-
power installations and the growing efficiency in steam gen-
eration of power, to such an extent that advocates of the
water-power bill intimated the possibility of an organized
effort on the part of the electrical engineers and water-power
companies to affect the pending legislation by depreciating
the potential and actual value of water powers in the minds
of the committee.
In support of his argument Mr. Lincoln said that engineers
have claimed it would be cheaper to install a steam plant
in St. Louis to furnish light and power in that city, than to
transmit hydro-electric power from the Keokuk dam. An
auxiliary steam plant, he claimed, could undoubtedly be
installed in Buffalo to take the peak of the load for that city
while the Niagara Palls Power Co. carried the main part of
the load, and the combination would give Buffalo cheaper
power than is now being furnished by the Niagara Falls
company. Is other words, the cost of the hydro-electric
installation to carry a high peak is disproportionate to the
return from this peak. He admitted, however, that, consider-
ing the entire load factor, the Niagara water power trans-
mitted to Buffalo was developed cheaper than power could be
generated there by steam. When questioned about Western
power development and costs, he suggested that if water-
power installation cost more than $150 per kilowatt capacity
in Los Angeles, it would probably be found that steam power
could compete with it.
Both O. C. Merrill, chief engineer of the Forest Service,
and George O. Smith, director of the U. S. Geological Survey,
attacked the statements of Mr. Lincoln and other engineers
who testified along the same line. Mr. Merrill declared that
Mr. Lincoln's statement that steam and hydro-electric pro-
duction cost on the average about the same was startling,
but wholly incorrect, and proceeded to quote figures from
plants in operation. According to these figures the actual
switchboard cost of power sold by the New York Edison Co.
(Waterside No. 2 station) is approximately five mills per kilo-
watt-hour. This cost includes labor, fuel, supplies and
repairs. On the basis of power generated, where 24.9 per
cent, is lost in distribution, the Edison station cost is approxi-
mately four mills per kilowatt-hour. Fuel and labor costs
of generation at steam plants in California were quoted as
0.336c. for Long Beach and 0.372 for Redondo, while the
generation cost at the Pacific Gas & Electric Co.'s Borel
hydro-electric plant was only 0.033c, or, with transmission
cost added, 0.12S cent.
"On this basis," declared Mr. Merrill, "it would be as
profitable to invest $3S0 per kilowatt capacity for installation
at the Borel plant, considering the load factors in each
instance, as to invest $50 per kilowatt capacity at the Long
Beach steam plant; while the fact that this steam plant
was being operated on a 20 per cent, load factor and the
hydro-electric plant at 69 per cent, load factor, justified even
a larger discrepancy in installation cost."
"In general," said Mr. Merrill," hydro-electric installation
costing eight times as much as steam, instead of three times
as much, might be considered economical and profitable."
Dr. Smith attacked the water-power engineers for having
made much of the increased efficiency of steam production
without having mentioned the equal Increase in efficiency
of hydro-electric production. Quoting from a report of Samuel
Insull, president of the Commonwealth Edison Co., of Chicago,
he showed that within the last ten years this company, with
its steam plant, had quadrupled its investment and increased
its output fifteen-fold. In 1903 a one-dollar investment in
the Chicago plant yielded 3 kw.-hr„ while in 1913 the one-
dollar investment yielded 10 kw.-hr. Chicago, all steam, now
shows a per capita consumption of a little over 300 kw.-hr.
and an average income of a little more than 2c. per kw.-hr.,
while San Francisco, part steam and part hydro-electric, shows
about the same average consumption, and an average income
of a little less than 2c. per kw.-hr.
As compared with the showing of the Chicago steam plant
of 10 kw.-hr. per dollar of investment, the San Francisco
plant had shown 6 kw.-hr. to each dollar of investment in
1911, while the ratio for the Montana Power Co. (all hydro-
electric), where the average consumption was as large as
1000 kw.-hr. per capita, was 15 kw.-hr. per dollar of in-
vestment.
Uinidl©v©E<n>p©dl P®w©2* ana JEasttesria
IRawers
The rivers of the northeastern and middle eastern por-
tions of the United States are the best known in the country
and the earliest in point of development, and their usefulness
as sources of power and centers of industry has been demon-
strated for several generations. Nevertheless, it has been
shown by the work of the United States Geological Survey
during past years and is demonstrated in one of the reports
of the Survey that in spite of the long familiarity of manu-
facturers and industrial men in general with most of these
rivers, the water resources they afford have not yet been
appreciated and by no means developed to their fullest ex-
tent. In fact, there are very few rivers in this great region
in "which the development of water power has come any-
where near the maximum possible degree of usefulness.
The report mentioned, "Water-Supply Paper 261," con-
tains records of flow during several years of the principal
rivers in the section referred to, which empty into the At-
lantic Ocean. In developing a water supply enormous sums
of money may be uselessly expended unless observations of
this kind are made throughout the various stages of stream
flow.
©2=
The rapid industrial development of this state in recent
years has given rise to numerous problems relating to water-
supply. With an annual rainfall of 45 in. both surface and
ground waters in Connecticut are large in amount, but the
rainfall is sometimes deficient through periods of several
weeks or months. Consequently, farmers must endure periods
of drought, manufacturers must provide against fluctuating
water power, and congested districts must arrange for ade-
quate water-supplies. With increasing population conflicts of
interest arise between water-power users and domestic con-
sumers, and towns dependent on the same streams. With the
development of irrigation and drainage another set of inter-
ests is making demands.
To meet the present situation and to provide for the future
the first step in the solution of the water problem is a com-
prehensive study of the facts as regards both surface and
underground supplies. How much available water is stored
in the gravels and sands and bedrock of the state? How much
does the amount fluctuate with the seasons? What is its
quality? How may it best be recovered in large or small
amounts? What is the expense of recovering it? How much
water may the streams of the state be relied upon to supply?
How much is polluted? How may the pollution be remedied?
To what use should each of the various streams be devoted?
What is the equitable distribution of ground and surface
waters among the conflicting industries and communities?
Realizing the importance of such studies to Connecticut,
the state joined forces with the Federal Government in order
to carry on the work. In 1911 a cooperative agreement was
entered into by the United States Geological Survey and the
Connecticut Geological and Natural History Survey for the
purpose of obtaining such information. The work in 1911-13
was done by A. J. Ellis and that in 1914 by H. S. Palmer,
both of the United States Geological Survey.
February 16, 1915
POWER
847
The five areas first chosen for study represent more or
less typical geologic conditions in different parts of the
state.
Reports, including detailed maps, of the Hartford, Stam-
ford, Salisbury, Willimantic. Saybrook, and Waterbury areas
have been completed and will be published at the expense
of the Federal Government, as water-supply papers for free
distribution. Similar reports on the Pomperaug and Plain-
ville areas pre in preparation, and tentative plans contem-
plate covering the other towns in the same manner in order
to obtain a detailed and authoritative inventory of the
ground-water resources of the entire state.
cieiacy &m\c
Model Wall Slhow How IRiw<es=s
At a meeting of the West of Scotland Iron and Steel
Institute, J. Golder, in a paper on "The Steam Turbine," said
that as regards efficiency, the Elberfeld turbine in 1902 gave
62 per cent. A Chicago machine is guaranteed to give 74
per cent. A 35,000-kw. turbo set for New York is guaranteed
to give 75 per cent, efficiency. As regards size of unit, so
far as the turbine is concerned, there is room for still
further increase, and 50,0OO-kw. sets are projected for the
Greater London scheme; 10,000 kw. is getting quite common.
A line of advance for which the turbine has long been wait-
ing is the combination of high power with high speed. Ideal
conditions for this are found in the case of the direct-coupled
turbo-compressor, and some remarkable machines have been
made.
For example, a Rateau turbine capable of 3000 hp. at 4000
r.p.m. has been installed in the Midlands. Generator makers,
realizing the possibility of this compact and cheap prime
mover, have risen to the occasion, and 3000-kw. at 3000
r.p.m. Rateau machines have been successfully installed.
Fraser & Chalmers have built a mixed-pressure turbine nom-
inally of 2000 kw. at 3000 r.p.m., but as this machine does
its full load with low-pressure steam, it follows that the
design is safe for a pure high-pressure turbine of about
double that capacity. Continental builders are said to have
made a 6000-kv.-a. set at 3000 r.p.m., and a 20,000-kw. set at
1000 r.p.m. The Chicago set of 25,000 kw. runs at 750 r.p.m.
Rateau sets are under contemplation for an output of 15,000
kw. at 1500 r.p.m.
Ftmlb)lic='U(tnllaty ILegpsls^aoini aim
Representatives of light and power companies have pre-
sented their arguments to the joint legislature of the State of
Washington, favoring a bill which provides that a company
desiring to found competing power plants must procure certifi-
cates of necessity from the public-service commission on a
showing that the company already in the field is unable to
furnish adequate service or is charging unreasonable rates.
A further provision legalizes indeterminate franchises subject
to public-utility commission authority as to rates and service,
leaving plants subject to municipal purchase as going con-
cerns by condemnation. Municipalities granting franchises
retain jurisdiction over original construction of plants or
systems. If the city and the company are unable to agree
upon terms in thirty days, the public-service commission is
empowered to grant the franchise. This power is also con-
ferred upon the commission in disagreements where one com-
pany is serving two cities or desires to pass through one not
served.
Representatives of the Stone & Webster Corp. addressed
the body on the proposed bill and urged its adoption, which
is practically assured. They stated that public service had
reached a point where it was no longer possible to attract
the capital needed for further development of power and
light projects, due to the fact that many franchises are now
entering upon the last year and the statutes give no security
in renewals upon which to base future bond issues for exten-
sions.
Another argument urged by the light and power men is
thaL the state, through the public-service commission, has
regulated their operation and fixed limitations of how much
they may earn on such investments, but has provided no
protection for the companies from irresponsible and ruinous
competition. They ask the enactment of the pending law as
a measure of protection to offset restrictions imposed by state
regulation of rates and service.
^©SiSSUlS'edl
To show the way in which rivers are gaged — that is, how
the volume of running streams is measured — by the United
States Geological Survey, the exhibit maintained by the Sur-
vey at the Panama-Pacific Exposition, in San Francisco, will
include a display of automatic gages, run by electricity, which
record the fluctuating heights of water of an artificial river —
one flowing through a tank.
The work of measuring the flow of the various streams of
the United States every day in the year and some of them
several times a day affords an invaluable basis for the study
of our water resources. Upon the data thus obtained engi-
neers depend in working out plans of water-power develop-
ment, irrigation, drainage — in fact, every project in which
running water is a factor.
JOHN QUINN
John Quinn, efficiency engineer of the Mingo Steel Works
& Furnaces, died on Saturday, Jan. 30, 1915. He was at his
desk at the usual hour on Saturday morning, but complained
of a sharp pain in the chest. He left the mill about 11 a.m.
for his home, and passed away quietly at noon. He is sur-
vived by the widow, two sons (Robert S., master mechanic,
and Herbert L., assistant master mechanic, Mingo Steel
Works & Furnaces), and four daughters.
John Quinn
Mr. Quinn was born in Ireland in 1S50 and came to this
country at the age of 20. He worked in a printing office in
Cleveland for a short time and then entered the employ of
the Newburgh Furnace, now the American Steel & Wire Co.
He moved to Mingo Junction, Ohio, in 1S82, as chief en-
gineer of the Junction Iron & Steel Co., and upon the con-
solidation of the Laughlin Steel Co. and the Junction Iron Co.
in 1884 he was made master mechanic, holding this position
*hrough the various changes made in this company until
1911, when he was made efficiency engineer.
He was a man of sterling character, high ideals and un-
questioned ability in his chosen profession. His advice and
counsel were eagerly sought, not only by the men in his
employ, but by his superiors.
Mr. Quinn was actively interested in the religious, char-
itable, educational, industrial and financial life of the com-
munity, being president of the board of stewards of the
M. E. Church, a member of the publishing committee of the
Pittsburgh "Advocate," a member of the Ohio Valley Hos-
pital Association, president of the Board of Education, effi-
248
POWER
Vol. 41, No. t
ciency engineer of the Carnegie Steel Co. and president of
the First National Bank of Mingo Junction, Ohio.
In his long association with the Carnegie Steel Co. he
made many friends among steel men and the allied industries,
who will learn with regret of his sudden demise.
the warring countries will naturally be less than originally
planned. The papers now rapidly coming in indicate that
the proceedings will form an important collection of engi-
neering data and a broad and detailed review of the progress
of engineering art during the past decade. The Committee
of Management is inviting all important engineering societies
to send delegates, and the presence of a considerable body of
them is well assured. Membership in the Congress, with the
privilege of purchasing any or all of the volumes of the pro-
ceedings, is open to all interested in engineering work. For
full particulars apply to W. A. Cattell, secretary, 417 Foxcroft
Building, San Francisco, Calif.
Francis W. Hoadley, well known to mechanical engineers
the country over from his long connection with administra-
tive forces of the American Society of Mechanical Engineers,
and since connected with the "Engineering Magazine," "Cas-
sier's," and other publications, has accepted a position upon
the staff of "Safety Engineering."
Clifton Reeves, head of the Reeves-Cubberly Engine Co., of
Trenton. N. J., has been chosen by Secretary Wilson, of the
Department of Labor, as a member of the Federal Board of
Arbitration, for duty in the South. He has gone to Wash-
ington to receive further instructions and proceed to his ap-
pointed field. Mr. Reeves' appointment to this important
board is the result of his interest and activities in labor mat-
ters. For 10 years he was secretary of the Employers' As-
sociation, during which time he assisted in the adjustment
of several labor differences. He has resigned his position
with the association, but will continue with the engine com-
pany.
B. F. Grout, consulting engineer, of Pittsburgh, Penn., and
at one time professor in the School of Mines of the University
of Minnesota, has recently been engaged by the Minneapolis
General Electric Co. in connection with the tests of the
efficiencies of its turbines in the Coon Rapids plant. Mr.
Grout, in connection with his work at Massena, N. T., in-
vestigated very fully what is known as the chemical method
of measuring the volume of water flow. In this method a
solution of salt is introduced into the penstock above the
water wheels, and samples of the water issuing from the
draft tube below give a measure of the quantity of water
passing through the wheels. Mr. Grout, on Saturday, Jan.
30, gave a talk on the subject of these chemical tests befors
the Engineers' Club of Minneapolis, at a dinner held at the
University Club.
BTUSHHESS STEMS
Louisiana Engineering Society — At the annual meeting of
the Society held Jan. 9, 1915, in New Orleans, the following
oncers were elected to serve for the ensuing year: President.
L. C. Datz; vice-president, Samuel Young; secretary, W. T.
Hogg; treasurer, E. H. Coleman; director, Ole K. Olsen (to
serve 3 years). The other members of the Board of Directors
holding over are A. T. Dusenbury, W. B. Gregory and W. H.
"Williams.
Boiler Inspectors — At a recent meeting of the American
Institute of Steam Boiler Inspectors of New York City, E.
Haggerty was elected president; J. H. Pollard, secretary; and
J. Turnbull, vice-president. The annual dinner will be held
Feb. 20 at Rector's, Forty-eighth St. and Broadway. Promi-
nent guests will attend, and with a star toastmaster in
charge, it is promised that the dinner will eclipse any of
the previous ones.
Equitable Dinner — In celebration of the completion of their
part of the work on the new Equitable Building in New York
City, about sixty mechanical and electrical material men gave
a dinner to William Gordon, superintendent of mechanical
and electrical equipment of the Thompson-Starrett Co., at
the Hotel Claridge, Friday evening, Feb. 6. The committee
of arrangements consisted of Paul H. Brangs, of the Heine
Safety Boiler Co., who acted as toastmaster and George L.
Gillon. vice-president of the National Metal Moldings Co.,
who was master of ceremonies.
International Fngineering Congress — The technical success
of the International Engineering Congress at San Francisco,
Sept. 20-25, is now well assured. From 200 to 250 papers
and reports, covering all phases of engineering work, will be
contributed by authors representing some eighteen different
countries. The Congress will, therefore, be truly international
in sroDe and character, although the representation from
The Terry Steam Turbine Co.,
inted E. F. Scott representative
with offices at 702 Candler Bldg.
Hartford, Conn., has ap-
for the State of Georgia,
The Pittsburgh office m
charge of H. A. Rapelye is now located at 1624 Oliver Bldg.
The Terry Steam Turbine Co., Windsor St. at Windsor
Ave., Hartford, Conn., is sending out a 64-page bulletin giv-
ing details on various turbo-pump applications. Anyone in-
terested in any kind of pumping problem can have a copy
for the asking.
The Builders Iron Foundry, Providence, R. I., has pub-
lished a new bulletin — No. 142 — which contains much inter-
esting and valuable information on many important water-
works systems throughout the United States and Canada. It
is sent free on request.
The Bruce Macbeth Engine Co., Cleveland, Ohio, has re-
cently received orders for one 150-hp. natural gas engine
from'the Magnolia Petroleum Co., Fort Worth, Tex.; one 60-
hp. artificial gas engine direct connected to generator, from
the Ingersoll-Gaukler Co., Detroit; one 90-hp. natural gas
engine from the Solar Electric Co., Brookville, Penn.; one
90-hp. natural gas engine from the Empire Marble Co., Cleve-
land; one 40-hp. natural gas engine direct connected to gen-
erator, from the Alhambra Theater, Sandusky, Ohio.
COMTIRACT
Bids received until Feb. 23, 1915.
Water Meters and Machinery
BUREAU OF ENGINEERING
DEPARTMENT OF PUBLIC WORKS.
Chicago, February 3, 1915.
Sealed proposals will be received by the City of Chicago
until 11 a.m. Thursday, February 25th, 1915, at Room 406
City Hall, for manufacturing and delivering to the City of
Chicago Water Meters, made according to designs prepared
by the City of Chicago. The following quantities of water
meters are desired:
1,500 %-inch meters.
2.000 1-inch meters.
750 lVj-inch meters.
750 2-inch meters.
The city will furnish detail drawings and one set of pat-
terns of each meter. The contractor is to turn over to the
city upon completion of his contract special machinery, tools,
dies, jigs, etc., used in the manufacture of the meters, ac-
cording to plans and specifications on file in the office of the
Department of Public Works of said city, Room 406 City Hall.
Proposals must be made out upon blanks furnished at
said office, and be addressed to said department, indorsed
"Proposals for Water Meters," and be accompanied with One
Thousand Dollars in money or a certified check for the same
amount on some responsible bank located and doing business
in the City of Chicago, and made payable to the order of the
Commissioner of Public Works.
The Commissioner of Public Works reserves the right to
reject any or all bids.
No proposal will be considered unless the party offering
it shall furnish evidence satisfactory to the Commissioner
of Public Works of his ability, and that he has the necessary
facilities, together with sufficient pecuniary resources, to ful-
fill the conditions of the contract and specifications provided
such contract should be awarded to him
Companies or firms bidding will give the individual names
as well as the name of the firm with their address.
L. E. McGANN,
Commissioner of Public Works.
,,^'^s^
POWER
Ill
Vol. 11
NKW YORK, FEBRUARY 33,
l'J15
\u. a
The Transmission Line
By Berton Braley
im&:
SIXTY THOUSAND volts I bear
On my towers, high in air,
From the river, frothing white,
From the turbines' whirling might,
To the city ways which beat
With a million human feet.
Touch me not — or you will die,
Yet the city's life am I,
And my very force which slays
Keeps the crowded streets ablaze
—Lights and signs that glow and gleam
Like bright figures in a dream.
When from every towering dome
Pour the workers, going home,
When the street-cars, clanging loud,
Move amid the surging crowd,
It is I who bring the force
Which propels them on their course,
I who lift the evening's pall,
I who light the buildings tall,
Yes, the glare that paints the sky
From the city — that is I!
So, along my copper trail,
Men must watch me, lest I fail,
Men must risk their lives to care
For the burden that I bear.
There's the city's work to do
And the current must go through —
For the lights that men must burn
For the myriad wheels that turn,
All the pleasure, toil and strife,
Look to me for light and life,
Yet, though I'm the city's breath,
Touch me not— for I am DEATH!
250
p u w e a
Vol. 41, No. 8
^/Ke Panama Paci/ic Inlernaiional Expo/iliorx
Race Track, Aviation and Athletic Field State and Foreign Pavilii
Drill Grounds Stock Exhibit Fine
Third of its class held in the United Stales and twelfth
of its class held anywhere in the world, the Panama-
Pacific Exposition was officially opened when President
Wilson touched the button last Saturday. Contrary to
the usual international expositions, it is not the celebra-
tion of an anniversary of some past event, but com-
memorates a modem achievement — the completion of
the Panama Canal. In its exhibits it is intended to show
particularly the advance which has been made in the last
ten years, or since the Louisiana Purchase Exposition.
There being less of history in it than is usual, it is espe-
cially interesting to contrast some things contemporane-
ous with the years of the various World's Fairs. For ex-
ample, in the steam-power field, we have, as typical of
their respective times, the big Corliss walking-beam
■ngine at the Centennial Exposition at • Philadelphia in
1876 the quadruple-expansion 2000-hp. Corliss engine at
Fkont End of the Palace oi Machines'!
the Columbian Exposition at Chicago in 1893, a 5000-hp.
angle compound engine and a steam turbine of 3000 kw.
at the Louisiana Purchase Exposition at St. Louis in
1904, with turbines as large as 5000 kw. built at that time,
and now 35,000-kw. turbines, though none of that size
will be exhibited at San Francisco, for the Panama-
Pacific Exposition does not generate its own power
for lighting and the operation of moving exhibits, but
purchases its current from the Pacific Gas & Electric
Co. which has over 90,000 kw. in hydro-electric in-
stallations and approximately 100,000 kw. in steam in-
stallations, the steam plants being boosters or auxil-
iaries in case of breakdown of the hydro-electric sta-
tions. Three-phase, 60-cycle, alternating current of 11,-
000 and 1< volts will be furnished in amount up to
9000 kw. between 5 and 7:30 in the afternoon of any day
or up to 15,000 kw. at any other time. The 18,000 kw.
steam plant of the Sierra & San Francisco Power Co. is
held in reserve, ready in case of interruption of the Pacific
Gas & Electric service. The exposition's secondary dis-
tribution is at various voltages — 117 for lighting, and
230 and 140 for power. Direct current by conversion
through motor generators is available at 250-125 volts.
The Centennial engine drove the machinery by means of
lineshafts gear-driven from the engine and extending
throughout the building.
Tin ( 'entennial Engine
This engine was really a pair of beam-engines and
formed the most prominent exhibit at the Centennial.
They operated condensing and were supplied with steam
at so lb. pressure. The valves and valve-gears were Cor-
liss and tlie cylinders were In in. in diameter with 10-ft.
stroke. The beams were 27 ft. long by !' It. deep and
weighed 11 tons each. The) were connected at right
angles to a shaft carrying the flywheel, which was a cui
gear wheel 30-1't. diameter and 2-ft. face, and was il
heaviest cut wheel that had ever been made up to that
time. It geared with a 10-ft. pinion on an underground
shaft 256 ft. long running across the building. This
lineshaft at each end and two intermediate points was con-
nected by 6-ft. bevel gears to transverse shafts extending
lengthwise of the building. These shafts were belt
eight overhead shafts, each 658 ft. long. The engine
made .'Hi r.p.m.. giving a piston speed of 720 ft. per min.
The peripheral speed of the spur gears was 3384 ft. per
min. The engines were rated at I 100 hp.. but could de-
velop 2000. The cylinders were jacketed with live slea
February 23, 1915
P 0 W E It
251
^an FrancL/co. Cali^rnia. Fbk20 io Dec.4,19D
id Industries
Mines and Metallurgy
"estival Hall
Machinery
The "Zone" Amusen
Concessions
Steam was supplied b) twenty vertical boilers tun
bj Corliss, which also supplemented the steam supp
the Pump Annex. Ea. li boiler contaii i :;' in.
in diameter in a shell 1 ft. n, diameter bi 11 ft. high.
The total heating surface of the twenty boilers was given
as 13,000 sq.ft.
Columbian Faik Engines
A heterogeneous collection of engines ., en at
Chicago — horizontal and vertical, high-speed and low-
speed— and no one type ran be taken as representative of
that time. The largesi engine shown was a 2000-hp. Allis
Reynolds-Corliss) engine with 20-, t0-, tin- and 70x
i-.'-in. cylinders and <;<i r.p.m. The flywheel was 30 ft.
diameter bj 76-in. fare and carried two belts 6 i't. wide,
each driving a Westinghouse 10,1 -incandescent-lighl
dynamo. Another notable engine was the 1250-hp. four-
cylinder triple-expansion Buckeye engine with its distinc-
tive valve-gear. Its cylinders were 20, :;■.' ami 36x48 in.
The flywheel was 20-ft. diameter by 72-in. face and it also
Vestibule to Tin: Palace or Machinery
252
P O W E R
Vol. 41. No. 8
MACHINERY BY/ILDING^
PHILADELPHIA 1876
n
POWER. TRANSMISSION
Source : One 1400-hp. slow- speed
Corliss ermine in. the center of one
of Ihe main bays.
Transmission by one main, line of
underf loor shafting, 352 ft. lon£
and 8 overhead lengthwise shafts
each 624ft. lon&.The intermediate
jackshafts were driven throuijSh _
6"ft. bevel fiears.
=ru
■■■M ATERIALSqf CONSTRUCTION1-
STOKE 15.000,000 L».
LUMBER 5.000,000 Bd.Ft.
WROUGHT IRON 760.000 Lb.
TIN ROOFING 700.OOOSq.Pt.
CAST IRON 500.000 Lb.
GLASS 175,000 So.Fr.
NAILS 20.000LB.
Constructed with brick curtain
■walls, square timber columns and
wrou£ht-iron roof
trusses
POST DETAILS
erd SHAFT BAN6ER.
HANDLING MATERIAL on. SKIDS and ROLLERS
I
MECHANIC TRANSMISSION
^ZL
February S3, 1915
row E i,
253
KT TWO EXPOSITIONS
SAN FRANCISCO 1915
7
MATERIALS qf CONSTRUCTION
PILES 45,000LmFr.
LUMBER 7.5OQ0OOBd.Ft.
B0IT5,WASHERS,Etc. 3.000.000 Lb.
COMPOSITION ROOFING 326,000 S<jTt.
GLASS 106,000 S<j.Ft.
HAILS 4 Carloaps
Built entirely of wood, being the largest
building of mill design
POWER DISTRIBVTION
Source :Two electric -power stations
connected by distributing mains
u/ith all parts of the building.
Total ?.O,000Hp.
Power Circuits Three -phase 60-
oucle 230-volt and single - phase
6<kvjclell7-volt.
Lighting Circuit: 60-cycle
117-volt three -wire ,
System
254
PO W E II
Vol: 41, No. 8
drove through a 6-ft. belt. It has since developed that
fewer cylinders and larger ratios are better and even
triple-expansion engines are not warranted except with
the higher pressures used in marine service.
Louisiana Purchase Exposition Engines and
Tuebines
At this time (1904), the struggle between the turbine
and the reciprocating engine was on and the advantage of
the former, even in large units, was yet to be established.
The largest turbines of their day were 5000-kw. Those
exhibited were a 2000-kw. Curtis, a 1000-kw. Hamilton-
Hol/warth, and a 400-kw. Westinghouse-Parsons. There
were 21 engines, of which the 5000-hp. Allis-Chalmers
angle compound was the largest, most impressive and
most typical of the art and time. It bad cylinders 11
and 94x60 in. and drove a Bullock generator by direct
there was do occasion to install a prime mover of the size
that must be taken as representative of this period for
large capacity. Such a one. however, is the 35,000-kw.
turbo-generator now being completed for the Philadelphia
Electric Co. This tuiit, with its condensing equipment,
will occupy a floor space of 1355 sq.ft., which is in marked
contrast with the 2376 sq.ft. required for the Centennial
engine. The horsepower output of the two units per
square foot of area occupied is 34.6 for the new turbo-
generator and 0.6 for the Centennial engine. The respec-
tive weights arc 1,200, lb. and 1,400,000 lb., and the
s] ds 1200 and 36 r.p.m.
Centennial and Panama-Pacific Machinery
Buildings Compared
The machinery buildings of the Centennial and Pan-
ama-Pacific expositions furnish a number of striking com-
[nside the Machinery Palace during the Installation of Exhibits
connection at 75 r.p.m. Pour three-cylinder vertical com-
pound 3000-hp. Westinghouse engines driving 2000-kw.
generators were really no! exhibits, but a part of the out-
lit bought by the Exposition.
Present-Day Prim k Movers
At San Francisco, as the exhibits arc not furnishing
power for any considerable part of the exposition's needs,
parisons and contrasts as shown on the two accompany-
ing pages. These give, by a few illustrations and tabu-
lated data, a comparison of general dimensions and a few
important features of these two great buildings. The
Centennial Machinery Hall was a larger building, both
in length ami floor area, than the present Panama-Pacific
Palace of Machinery. Put this must not be looked upon
as a step backward, for at Philadelphia the building de-
iruary 23, 1915
p < > w e i:
355
retell to machinery included everything that could be
brought under that general head. In keeping with our
present tendency toward specialization, the exhibits at
San Francisco have been divided so that printing presses,
typewriters, and similar machines now go to the Palace
of Liberal Arts, while locomotives and all means of trans-
portation have a building of their own.
One of the striking contrasts between the two build-
in..:'- is in the materials of construction, for strange as
ii may seem, mure metal was used in the Machinery Hall
..I Philadelphia in years ago than in the present Palace of
Machinery in San Francisco. The two pages of illus-
trations give a hint as to the kind and quantity of these
materials.
Another contrast worthy of mention lies in the provi-
sions made for installing exhibits. In Philadelphia there
was a total absence of crane service — not a single crane of
any kind was used. At San Francisco there are two 30-
ton cranes in the middle bay, with one 20-ton crane in
each of the two principal side hays. The skids, rollers,
ami tackle lit 1876 have given way to the traveling cranes
of L915.
General Features of the Present Fair
The grounds are in the city limits of San Francisco and
face north on the bay. There are 2% miles of buildings,
covering an area of 635 acres. While this area is only
about half that occupied by the St. Louis Fair (1240
acres) and not even quite as much as the Chicago Fair
(733 acres), this is an advantage rather than otherwise,
for it means that the tiring distances in he walked are
less. It cost more, however, than any exposition to date,
for it represents an investment of $58,000,000, whereas
the Louisiana Purchase Exposition cost $50,000,000, the
Columbian Exposition $20,000,000 and the Centennial
Exposition $8,000,000. For the present fair nothing
was contributed by the Government as in the cases of the
Chicago and St. Louis expositions. The palaces cost more
than $12,oo().o()(i. Another distinguishing feature of this
Fair is that the structures were finished three months
before the opening, and it was the first international ex-
position to be considered completed on tune.
White does not predominate in the buildings. The
walls are of an ivory tint, and the roofs generally red and
llat, with great domes ami lofty towers of blue and gold,
and green-latticed windows. Add in this the effect of the
myriads of flowers, palms ami trees, and it is evident that
there is here no lack of color.
The tallest feature is the Tower of Jewels. 435 ft. high.
Hn either side of it are the main exhibit palaces. 14 in
number. Height m general marks these buildings as
compared with the previous fairs, for the Avails of the
palaces are as high as the average six-story city block,
•lust east of the group is the amusement section known as
"The Zone," to which there has been devoted 65 acres.
To the west of the group are the pavilions of the 12 states
ami 38 foreign countries participating. In addition there
are the parade grounds, live-stock pavilion, life-saving
stations and the aviation ami athletic field.
Eight exhibit palaces subdivided by courts make up
the main group, seemingly under one roof ami appro-
priately called "The Walled City." The buildings arc
in a rectangle, their walls being interconnected and
broken only by archways and entrances giving access to
the courts between the buildings. The buildings are all
of tlie same height ami the architecture generally similar.
The courts dividing them north ami south are known as
the Court of the Universe, tin/ East court, or the Court of
Abundance, ami the West court, or the Court of the Four
Sen-, ,ns. These eight central palaces are: Mines ami
Metallurgy, Transportation, Agriculture, Food Products,
Varied Industries, Manufactures, Liberal Arts, ami Edu-
cation.
Palace of M mhixery
Flanking this group on the east is the Palace of Ma
thinery, in which centers the most of interest to PoWEJi
readers ami of whose exhibits mure will be told in later
--lies, h ,,,-t approximately $650,000, and is the largest
wooden building in the world. It was the first of the ex-
position palaces to be completed. Ground was broken on
New Year's Lay. 1913. The architecture is Roman, ami
i he decoration is classic in form, but modern in expression
and suggests machinery ami invention. Inside, the build-
ing, is divided into three north and smith aisles, each 101
ft. high ami 75 ft. wide, extending the length of the build-
ing which is 961 ft. long. On each side of the main struc-
ture are side aisles 70 ft. wide covered with shed roofs 1 1
ft. high to the soffit of the trusses. The total width of the
building is :;<;T ft. ami the total floor space 370*000 sq.ft.
In other words, it is about three blocks long, Sy2 acres in
size and as tall as a 13- or 1 1-story building. Lincoln
Beachy, the aviator, flew from one end of it to the other
under the roof. This was the first time an aeroplane
flight was attempted indoors.
To facilitate the installation of heavy exhibits there
are two 30-ton traveling cranes with 5-ton auxiliary
hoists in the middle bay and a 20-ton traveling crane in
each of the two principal side bays, all operating the
length of the building. Railroad tracks enter and cross
the building at the center at right angles to the crane
travel, so that shipments received by rail can be unloaded
from the cars directly by the cranes.
The first machinery exhibit was installed May 27, 191 I.
nine months before the opening of the Exposition. 'Phis
was a Busch-Sulzer Diesel engine of 500 hp. The occa-
sion was celebrated with fitting ceremonies attended by
exposition, state ami city officials and several hundred
engineers. The exhibit is to In1 seen in one of the illus-
trations herewith.
Wherever possible, the exhibits are to be in operation,
ami many of them will also embody the exhibition n!'
-aietv devices being arranged by William Dbolittle, safety
inspector of the National Metal Trades Association.
To increase the convenience of viewing the building's ex-
hibits electric chairs operating on tracks are provided, s, ,
that visitors may go from place to place by the pressing
of a button and thus may spare themselves the fatigue
which is such a drawback to exposition sight-seeing.
The sculptural feature of the Machinery Palace are
three figures typifying the Triumvirate of Power, which
are repeated in rotation at the tops of the 60-ft. columns
flanking the entrances. These are called "Electric
Power," "Inventive Power" and ■"Steam Power" and are
the work of Haig I'atigian. an Armenian by descent, but
a resident of San Francisco. They are 16 ft. high and of
a deep-golden color. Electric Power shows a man con-
trolling a lightning holt with his right band, and dominat-
ing earth under his left foot. Inventive Power is sym-
bolized by a heroic figure wearing the wreath of achieve-
ment ami holding in his right hand a globe from which
rises in flight a winged man. The power of steam is
256
POTVEE
Vol. 41, No. 8
typified by a man in the act of creating motion with a
driving rod of a steam engine attached to a crank which
gradually blends with the earth.
Othee Buildings
Flanking the central group upon the west and sepa-
rated from it by a lagoon, which it partly encircles, is the
Palace of Fine Arts. The Palace of Horticulture rovers
approximately five acres and lias as its most prominent
feature a steel dome 186 ft. high and 153 ft. diameter,
surmounted by a half-sphere '.'li ft. high, weighing .'<:
tons. It is planted with flowers and at night is one of the
Argentina. Australia, Austria, Bolivia, Brazil, Canada,
Chile, China, Costa Rica, Cuba, Denmark, Dominican
Republic, Ei uador, France Guatemala. Haiti, Holland,
Honduras. Italy, Japan, Liberia. Mexico, Xew Zealand,
Nicaragua. Norway, Panama, Persia, Peru. Portugal, Sal-
vador, Spain, Sweden. Turkey. Uruguay and Venezuela.
Visiting the Exposition has been facilitated as much
as possible by the railroads and local hotels. Bates are
being offered on all lines and the hotel men have formed
an association, binding themselves to adhere to reasonable
prices. In addition numerous boarding houses are avail-
aide, so that accommodations within the means of all are
One of the Three Main Portals of the Palace of Machinery
most spectacular features of the illumination. Festival
Hall will be the rendezvous of conventions, among them
the Engineering Congress next fall. Nearly all of 350
congresses anil conventions will be held here.
Methods of indirect lighting are used for out-of-door
effects for the first time at any exposition. The palace
walls are flooded by light from high-power arcs, concealed
or shaded from the eyes of the spectators by ornamental
metal shields or banners. Domes are illuminated from
within by powerful searchlights arranged to give varying
colored effects. Architectural features are accentuated by
the use of "jewels" of polished crystal.
Of the nations which committed themselves to partici-
pate before the war. none has withdrawn. They include
claimed to lie provided in abundance. Still, it is urged by
the management that prospective visitors secure their
reservations in advance to forestall any chance of dis-
appointment in getting just what they desire.
One of the most important features of the Exposition
will be the series of congresses, conferences and conven-
tions. A- the material exhibits will show world progress
on all lines, so will the congresses gather together the ex-
perience of the ages in education, science, art. industry
and social service.
All. in all. the Exposition holds attractions that cannot
but make it worth while to any who can find the oppor-
tunity, to see it, and this aside from the advantage- of
viewing the country there and on the way.
H'liruarv s.
L91S
P O W E R
25:
Goulds Samig]le=Stie5ig© Cenaftipif=
The illustration shown herewith i- that of the Goulds
hoi'i/oiital single-stage, single-suction, inclosed-impeller
Rntrifugal pump with the casing and bearing cap re-
■oved. This pump is designed for directly connecting
with electric motors, and is intended to run with differ-
ent speeds for different capacities and heads.
bearing upon babbitted surfaces. These collars also serve
to space the impeller properly in the casing. The water-
way, or volute, is proportioned to convert the energy of
the velocity of the water leaving the impeller into pressure,
with a minimum of loss due to shock or eddies.
The casting forming the stuffing-bos cover of the cas-
ing contains two bearings and carries the complete pump
when assembled. The outboard end is split horizontally:
the bearing cap is held in alignment with the hearing by
Centrifugal Pump with Casing and Bearing Cap BorovED
The casing is of the volute type, supported on the
bedplate so that it can be swiveled in any one of eight
positions. This is a convenient Feature where space for
pipe fittings is limited, and also allows a discharge elbow
to lie dispensed with.
The impeller is of the inclosed type and is hydraulically
balanced against end thrust. The slight amount of end
thrust occurring in operation is taken up by shaft collars
the taper dowel pins and studs with locknuts. An opening
with a hinged lid is provided in the top tor inspection
of the oil rings. Between the inboard end of the bear-
ing and the lace of the stuffing-box there is provided a drip
pocket with a drain hole, which catches the necessary drip
from the gland and is piped to a sewer.
This pump is manufactured by the Goulds Manufactur-
ing Co.. Seneca Falls, N. Y.
'mss
SYNOPSIS — Will Quizz, Jr., in looking on while
a hydrostatic test is applied In o boiler, sees a dem-
onstration of //<///• Hi i spoils system usually works
nn l. Will, however, derives some benefit from liis
experience by consulting Chief Teller.
9
pressure up to 200 lb., when the shell leaked like a sieve.
One nt' us has this percentage business twisted. What i-
a 50 per cent, over-pressure, Chief, and how do you figure
it? 1 want to know which of us was wrong."
"I am glad you got some practical information during
your vacation. Will, by seeing how other plants are operat-
ed. Per cent, means 'by the hundred.' Your problem is eas-
ily illustrated by our decimal money: A dollar is 100
cents, and one penny or centum is therefore 1 per cent.
A dime is ten one-hundredths, or 10 per cent., and half a
dollar is 50 per cent. One hundred represents the base
and 50 per cent, added would, of course, he a total of 150.
'•You say the boiler is intended lor 100 lb. steam pres-
sure, and that it was to he tested to 50 per cent, over-pres-
sure. Fifty per cent, of 100 lb. is 50 lb. Then the total
test pressure should be
100 + 50 = 150 Hi.
By putting on 200 lb., or doubling the working pressure.
the inspector added 100 per cent., incidentally showing
an extremely low percentage in his knowledge of percent-
age."
858
I'D WEE
Vol. il. No. 8
ip&A~]P]hflgg EgEnMiomi
I'.v Albert li. [sbaei
SYNOPSIS — Explanation of the induction
and ma >!i">t of tlu
mon systems of spark-plug ignition.
Simple Induction Coil
The air gap across which is sent the ignition current
offers a very high resistance to it- passage. For tin-
son a current of low voltage from a battery or a low-ten-
sion magneto is unable to jump the gap. To transform
this low-potential current to one of very high potential,
amounting to many thousand volts, a device known as the
induction coil is employed.
In its simplest form, the induction coil is composed
of several layers of coarse wire (the primary I wound
around a cure of soft-iron wire and surrounded by many
layers of tine wire (the secondary). The core tends *o
concentrate the lines of force and becomes an electromag-
net when the coil i< m use. In Fig. 1 i> shown such a coil,
with only one layer of eai h winding, fur simplicity.
When a current is sent through the primary a magnetic
field is set up around it. the lines of which pass through
the core parallel to the axis, coming out at one end and
entering at the other after passing through the layer- of
the secondary winding. A current is thereby induced
in the secondary, the potential of which depends on the
relative number of primary ami secondary turns. When
the current through the primary has reached a constant
value, the induced current in the secondary ceases to flow.
The magnetic field set up by the primary also tends to
retard the current flowing through it, so that it takes
longer for the field to build up from zero to maximum
than to drop from the maximum to no field when the flow
of current ceases. The voltage of the current generate I
in the secondary winding depends also upon the rapidity
with which the intensity of the magnetic field changes.
For this reason the current generated in the secondary is
of much higher potential when the circuit through the
primary is broken than when closed.
Xo current can be induced or generated in the sec-
ondary winding unless the intensity of the magnetic field
is either increasing or decreasing. Thus there arc two ini-
p ilses of current in the secondary, one when the primary
circuit is closed and the other when it is opened; but, as
previously staled, the current induced at the break of the
circuit is the only one of sufficient voltage to be utilized.
Induction Coil with Vibeatoe
The simple coil jusi described i- used in a system ex-
plained later, where the make-and-break occurs once for
each explosion and where onlj one spark is produced.
There are systems, however, in which a series of shori
sparks are produced for em h ignition. These add a -mall
mechanism to the simple coil, called a vibrator (see Fig.
'.' i. A current sent through the primary produces a mag-
netic field, making the core an electromagnet. The ten-
sion of the spring tend- to keep the two platinum points
together, thereby keeping the primary circuit closed: but
when the core become- magnetized it exert- enough force
to attract the spring and open the circuil rapidly. \-
- i a- the circuit is opened the core becomes demag-
netized and the spring flies back, again closing the circuit.
This making and breaking of the circuit by the vibrator
occurs at the rate of aboul one hundred per second, de-
pending on the adjustment. Each time the primary cir-
i n it i< broken a small current of high potential induced
in the secondary jumps the air gap of the spark plug.
As previously stated, a current is also induced in the
primary winding each time the circuit is broken, and
unless a condenser is employed to take up this current,
considerable arcing will occur at the two platinum points,
preventing a rapid break of the primary circuit and burn-
ing away the points in a short time.
The condenser consists of layers of tinfoil separated
from each other by a waxed- or varnished-paper insula-
tion. No connection i- made between the two sides of the
riser within itself. The action is such that the cur-
rent generated in the primary winding when the circuit
i- broken is absorbed by the condenser, but as soon as this
induced current ceases to flow the condenser discharges
again. The discharge current, however, flows back
through the primary in the opposite direction to that of
the battery current, thereby quickly demagnetizing the
core. Therefore, the condenser not only does away with
the undesirable .-parking at the points, but also lessens the
•r Platinum Comucts
' 'Kirk Plug Ertd
Secondary
U J LA-A"
Fig. 1. Simple
J x diction Coil
■ Spring
S^_/ Batferu orLotf Tension
Magneto End
Fio. -.'. (.'oil with Vi-
beatoe and Condenser
thee to the flow of the battery current. It is gener-
ally inclosed in the box containing the coil.
Since1 the secondary current is of very high potential.
there would be danger of the insulation being punctured
if th.e circuit through this winding could not be com-
pleted. Tin- might happen if a wire had been discon-
nected from a spark plug, if one of the secondary leads
were broken, or if the ground connection became loose
or had been left off. Therefore, to prevent the destruction
of the coil from thi i safety spark gap is inserted
in the system of each induction coil and high-tension
magneto. The distance between the two point- is greater
m the safety gap than in the spark plug, hence the current
will always jump the gap in the spark plug, except under
tin' i onditions mentioned.
Tht M igneto
In the induction coil just described the secondary wires
remained stationary, while the lines of the electromag-
netic field i hi them as the intensity of the field was
: It instead a stationary magnetic held be em-
ployed and the win- lie moved through it, a similar re-
February
L915
P ( ) W E K
250
miIi would be obtained. This is the principle employed
in the magneto, the essential parts of which are the per-
manent magnets producing the magnetic Seld, the pole-
pieces through which the magnetic lines of force pass
before crossing the path of the armature, and the arma-
ture which consists of a core ami windings. The core is
generally of the shuttle type and the windings depend on
(he type of magneto; if lew tension, the windings consist
merely of heavy wire.
The current generated is not constant during one revo-
lution of the armature, hut whenever the armature wind-
Piq. ■>. Make-and-Break with Simple Coil and
Spare Plugs
Lng passes through the strongest portion of the field, the
maximum current is generated; this happens twice dur-
ing each revolution. To obtain the best spark the maxi-
mum current must he utilized, and to do this the mechan-
ism must he constructed so as to make this adjustment
possible. The interrupter is generally on the same shaft
as the armature, hut the distributor arm is on a shaft
placed above the armature shaft ami is geared to the
latter. The armature shaft and distributor shaft are so
geared that when the interrupter acts to produce a spark
the distributor arm will he in contact with or over one
of the segments. To make clear the relation between the
speeds of the shafts, assume a four-cylinder four-stroke-
cycle engine. Two explosions occur per revolution of the
crankshaft and, since two breaks occur at the interrupter
points per revolution of the armature shaft, the speed of
Contact Segment
Spark
Plug
Induction Coil
Ground Connections, >-i
Fig. 4. Vibrator Induction Coil (Single Coil)
the two will he the same. There will be four segments,
one for each cylinder, to distribute the high-tension cur-
rent: thus the distributor shaft will make one-half a
revolution for each one of the armature shaft.
Difference between High-Tension and Low-
Tension- Magnetos
The chief difference between a low-tension and a high-
tension magneto is that the latter is self-contained and
very compact, while the former requires a separate in-
duction coil. The high-tension magneto has wound on its
armature, in addition to the layers of heavy wire, manj
layers of light wire which ^n-\c as a secondary winding.
Instead of using a separate coil the armature serves both
as a generator ami as an induction coil.
The diagrams showing the different systems have I n
drawn to show the wiring and not the constructional de-
tails; therefore, the interrupter has not been shown on the
shaft with tin' armature. Another thing to note is that
the safety spark gap and the condenser have been omitted
to prevent confusion.
Simple Coil (Make-and-Break)
When ordinary spark plugs are employed the make-and-
break points are outside the cylinder. There are two
systems in general use, one in which there is a long make
and a second in which there is a very short make. The
mechanism is so timed that it is mechanically operated
whenever the spark is to occur. The break in the latter
system occurs so quickly after the make that the eye can-
not detect the two points in contact at all. The I'uiida-
Spark Plug
Ft.
' Battery
Vibrator Induction ('oil (Multiple Coil)
mental principle of operation is the same, however, in
both (see Fig. 3).
The current passes from the positive terminal of the
battery through the primary winding when the points are
in contact. This produces a strong magnetic field in the
coil, and when it is allowed to shrink suddenly on the
opening of the circuit, a current of high voltage is induced
in the secondary. The latter flows through the distribu-
tor and jumps the gap in the spark plug, completing its
circuit by way of the ground.
Vibratos Induction Coil (Single Coil)
In this system, which is shown in Fig. 4, a single in-
duction coil is used. When the timer or commutator
closes -the primary circuit, which occurs when the roller
is in contact with the segment, a current flows from the
positive terminal of the battery through the vibrator, the
primary winding, the ground and the roller to the nega-
tive terminal of the battery, thus completing the circuit.
Each time the circuit is broken by the vibrator, a high-
tension current is induced in the secondary, which jumps
the spail-. -up of the spark plug. The spark produced at
the gap is not merely one, but a series of sparks which
succeed each other so rapidly that they appear continuous.
2C0
PO W E R
Vol. II. X... 8
It should, of course, be understood that the roller mech-
anism of the timer is connected by shafts and gears to the
crankshaft, so that there is a definite relation between the
speeds of the two, and the spark is made to occur at a
definite time.
Vibratos Induction Coil (Multiple Coil)
The wiring of this system (see Fig. 5) is so arranged
that whenever a current passes through any of the in-
duction mils, it must firsl pass through the master vibra-
tor which is in series with each coil. This saves the use
of a number of vibrators and gives a spark of the same
intensity m all cylinders. Assume that the roller mech-
anism is rotating in the direction indicated by the arrow.
When it touches segment \o. 2. the circuit through the
primary is closed, provided that the switch is on. The cur-
rent then passes from the positive terminal of the battery,
through the winding of the master vibrator, coil X... -J.
segment 2 and back to the battery, causing the vibrator to
act as before explained. Each time the circuit is closed
Spark Plugs
"Insulated Contact
Fig. 6. Low-Tension
.Magneto
Fig.
High-Ten >m\
Magneto
and broken by the vibrator a magnetic field appears and
disappears in the induction coil Xo. 2, and sets up a sec-
ondary current of high potential, which current jumps
the air gap of Xo. 2 plug. The primary wire from each
of the induction coils to the commutator also serves to
ground the secondary wire on the respective coils, thereby
eliminating four wires. In following out the circuit- it
should be noted that the roller mechanism is connected to
ground.
Low-Ten sn>\ Magneto
The system shown in Fig. 6 will operate m either of
two ways, depending on the design of the rotating cam
which operates the interrupter mechanism. With the cam
as shown the system work- as follows: The current gener-
ated in the armature of the magneto passes through the
primary of the induction coil, except when the points of
the contact-breaker come together. It is so arranged that
the points come together while the maximum current is
being generated in the armature. At this instant the
major portion of the current passes through the inter-
rupter. The sudden decrease in current flowing through
the primary of the coil causes a rapid shrinkage of the
held, which, in turn, induces a small current of high volt-
age in the secondary winding; this passes through the
distributor, across the air gap in the plug and through
I he mound, completing its circuit.
When the cam shown at .1 is used the points of the
interrupter are always in contact except during a short
period preceding the production of the spark. The cur-
rent from the armature of the magneto passes through
the interrupter until the point 0 of the cam reaches the
breaker arm. At this instant the points separate and the
whole current is forced to pass through the primary wind-
in-' of the induction coil. Although this induces a cur-
rent in the secondary winding, it i> not of sufficient poten-
tial to jump the spark gap. While the maximum current
is being generated in the armature, the point D on the
cam strikes the breaker arm and the contact points are
instantly brought together again. The larger part of the
current now flows through the interrupter again and the
rapid decrease in the current passing through the primary
winding causes a sudden shrinkage of tic magnetic field.
This induces a current in the secondary of sufficient ten-
sion to jump the spark gap.
High -Tension Magneto
The system shown in Fig. 7 is often called the true
high-tension magneto system. The breaker or interrupter
mechanism is on the shaft carrying the armature and
rotates with it. The roller cams, on the other hand, may
rotate on pinions whose positions remain fixed.
In the position shown, the grounded contact arm is
about to lie pushed inward by the roller cam; thus the
interrupter points are about to separate. The armature is
short-circuited through the interrupter points except
when the spark is to occur. The mechanism is so timed
that this takes place when the maximum current is being
generated. When a spark is to occur the points are sepa-
rated and the primary circuit is opened. The current im-
mediately ceases to flow through this winding, causing the
field to shrink very rapidly. This, in turn, induces a
small current of high potential in the secondary winding
on the armature, which passes through the distributor,
jumps the spark-plug gap and completes its circuit
through the ground.
Dual System
Tn this there are two distinct ignition systems which
are generally not connected in any way, two sets of spark
plugs often being employed. It. is a combination of the
systems shown in Figs. 5 and 7, namely, the vibrator in-
duction coil and the high-tension magneto.
Duplex System
This system is the outcome of an improvement on the
one shown in Fig. '. The high-tension magneto is so
designed that the armature may be used not only as an
induction coil for the current generated in itself, but
also for the current from' a battery. Thus only the bat-
tery is added, but the wiring becomes more complex. An
advantage is that without separate induction coils the
engine may be started on battery current, which is gen-
irally easier than with the current from the magneto.
This i- due to the fad that the engine must attain con-
siderable speed before the voltage of the current generated
,u the magneto becomes equal to that of the battery,
namely, six to -even volts.
Februan 23, 1915
PO"W E I!
261
es*
By Alfred < Iradenwitz
A new type of 1>1< iwcr has I n brought out by Messrs.
Siemens-Schukert Werke, of Berlin, Germany. Like all
blowing machines "I the screw type, the Schlotter blower,
Fig. 1, requires but small floor area, is bigh-8] d and
FlCi. 1. SCHLOTTEB BLOWER, MOTOB DRIVEN
Fig. "2. Rotok and Casing
is reversible. Back pressures up to 1 L5-in. water column
are overc ■ bj a single-stage blower, the maximum
efficiency being upward of M<> per cent.
Each blower comprises a 5-vane rotor, Pig. 2, and a
guide wheel, Fig. 3, at the outlet. The1 thrust surfaces
of both wheels arc of the s rm type, that is. surfaces
engendered by the rotation of a line and its simultaneous
displacement along the axis of rotation. The feature of
the guide-wheel principle is that the entrance edges of
the guide wheel, so far from coinciding with the outlet
edges of the rotor cross them at right angles everywhere.
The air current issuing from the rotor is thus subdivided
radially by each guide blade and is. at a given air supply,
dealt with without a shock.
The curvature of tin: guide blades, which increases in
the direction of rotation of the rotor, results in a con-
Fig. :;. i iinu; Wheel of Blov\ eb
traction of the air current and in a further acceleration
of the resting guide wheel, so that a considerable portion
of the axial thrust, is engendered in the latter. Because
of the inertia, the air currents on issuing are slightly
rotating and convergent to the axis, so that the minimum
cross-section of the jet in the case of a free motion of
the air lies at about half the Length of the diameter in
from of the distributor.
+- 60
£ 50
c
| i0
20
lilll
0.3 04
05
03 1.0
Fig. I. Efficiency Curves of Schlotteb and
Centbifi gal Fan of Usual Design
The ell'u ieiicy of a blower depends mainly on the extent
[o which dynamic pressure in the adjoining tubings can
be converted into static pressure. Tests have shown a
maximum efficiency of about so per cent, to be obtain-
able in tlie rnosl favorable case, when connecting the
blower to a line of pressure pipes, and 75 per cent, can
262
POWE B
Vol. -II, No. 6
he reached with a short outlet tubing corresponding to an
increase on cross-section of about 20 per cent., the effi-
ciency decreasing in the case of a diffuser, according to
the widening of the latter. These results have been
confirmed by tests made on a number of middle-sized
blowers, chosen at random, by Professors Brabbee and
Kloss. of the Berlin Technical High School, the maximum
efficiency found with a pressure pipe connected to the
blower being TS per cent.
An even more important factor than the high maximum
efficiency is the fact that the efficiency curve of the
Schlotter blower is flat, so that the efficiency remains
high over a wide range of loads, from the highest back
sure down to a free escape. In Fig. 4. curve .1 shows
the efficiency curve of a Schlotter blower as compared with
that of a centrifugal fan of the usual design, as shown in
the curve P.
Another advantage of the blower is that its power con-
sumption for a given number of revolutions remains
stant over practically the whole range of loads. This
is valuable in case the back pressure of an installation
cannot be predetermined exactly or when working condi-
tions, with a given amount of air. entail variations in
back pressure, such as, for instance, with the individual
ventilating of mines, when using air pipes of variable
lengths.
i lie annular east-iron body of the blower is provided
with a foot and comprises in its hollow hub the beai
carrying the shaft on the journal of which the rotor and
the half coupling (belt pulley) are keyed overhung. Ball
bearings are used. Water cooling is provided for the
j- when the blower is used with hot gases.
Tlie standard design is modified in various ways to
suit spieeial requirements. The annular body may be
fitted with a flange in the place of the foot, in case the
blower is to be fixed to a wall. Since every blower is
fitted with a thrust bearing to .leal with the axial thrust.
there is no objection to placing it in a vertical position.
When the blower is to work through a conduit, a suction
bend is joined to the annular body through which the
driving shaft passes.
The rotors are east either of some light metal (special
aluminum alloy) or a high-grade bronze, according to
their dimensions and numbers of turns and the gas
temperature.
The blower is preferably driven through direct coup-
ling with electric motors, steam, water or air turbines.
The most important applications of the blower are for
ventilators for boiler and engine rooms; for the individual
and main ventilation of mines and tunnels; for air heat-
ing, drying and mist-dispelling plants; for forced-draft
furnaces and for the removal of dust and shavings.
>igirMinig
iministorinaieiFS
By Norman G. Meade
SYNOPSIS — Actual inhalations in tin- design of
n small transformer such as used for bell cir-
cuits or signaling devices.
Small transformers with low-voltage secondaries are.
to a large extent, replacing batteries for many purposes,
such as the operation of electric bell-, signaling devices,
ete. ; and where alternating current is available they are
much more satisfactory, as they require no attention. As
the secondary voltage i< generally below 12 or 15 volts,
ordinary bell wiring is sufficiently insulated for the sec
ondarv circuits.
The design of the small transformer involves the same
calculations as transformers for lighting and power pur-
It is necessary to know or assume several quan-
tities, such as the useful secondary output in kilowatts,
the primary voltage, mdary voltage, and the frequency
of the system on which the transformer is to operate.
Let it be desired to design a transformer to operate from
a 110-volt, 60-cycle circuit, which will have a secondary
voltage of 10 and a secondary current of 10 amp.
_ ,. . watts output
Efficiency = — - —
watts input
For an output of 100 watts, assuming an efficiency of 85
per cent..* the input would be 100 -=- 0.85 = 118 watts.
Therefore, the total estimated losses are not to exceed 18
watts. These losses are made up of three components —
hysteresis, eddy currents and copper losses. The copper
or T'B loss and the core loss (hysteresis and eddy cur-
rents i should be about equal. For intermittent service
the copper loss can be somewhat the larger of the two;
hence it will be taken as 10 watts and the core loss 8 watts.
Assume the density of the sheet-iron core to be 30,000
lines of force per square inch. For annealed sheet iron
at this density, the hysteresis loss is 0.15 watt per cubic
inch. The eddv-current loss should be small on account
-<— -
35a-
k
<a >
K
<'---l.5a->
y
< a->-
k
t
k
A
*^
*l.i!>
Hi''
£.
y
Figs, l and 2. Cose Dimensions
of the laminated core; therefore assume it to be 2 watts
and the hysteresis loss o' watts. The volume of the iron
in the core will then be
6
07l5
40 cu.in.
•This efficiency is somewhat lower than would be obtained
in a well designed transformer of this size under full load. —
EDITOR.
The core must be proportionate with regard to the
winding space and the length of the magnetic circuit. Let
a represent the width of the core, as in Fig. 1, 7a the
height of the core, 3.5a the total width. 1. 5a the horizon-
February 23, 1915
powe i;
263
tal inside distance between legs, and 5a the distance be-
tween the yokes. The cross-section of the core is a2. Then
the volume of the core is
V = (2 X 3.5a + 2 X 5a)a2
V = 17a3
40 cv.in.
Whence, a = yl *« = 1.34, approximately.
Let a be 1.5, on account df sonic loss of space due
to laminations. Then the core dimensions will be as shown
in Fig. 2 and the available winding space will be 2.25 in.
between cores and 7.5 in. between yokes. Let the length
of coil be 7 in. The secondary will be wound next to the
cores so as to reduce the length of the heavier wire, and
the primary will be wound over the secondary. The sec-
ondary current at full load will be 10 amp., and, as
the primary and the secondary coils are wound in two
sections, tile secondary voltage for each coil will be 5
volts, but the conductor will carry 10 amp. Allow 1000
circ.mils per ampere. Then the size of the secondary con-
ductor will be 10 X 1000 = 10,000 circ.mils, which cor-
responds nearest to a No. 10 wire.
The primary watts at full load are 118; hence the
primary current will be
Primary watts 118
Primary voTfiuje = 110 = L0T amp-
The power factor can be neglected and, as the magne-
tizing current is small, the primary current will be taken
at 1.25 amp. The size of the primary wire will then be
Core
-Insulating Tube
Secondary Coll
Insulation
'Primary Coit
'Insulation
Fig. 3. Suction through Core and Coil
1.25 X 1000 = 1250 circ.mils, which corresponds nearly
with a No. V.) wire.
The relation between the maximum flux and tl ffec-
tive primary voltage is as follows:
F _ 4.44 N X TpXn
p 108
where,
f*p = Primary voltage;
N = Maximum magnetic flux;
Tp = Primary turns;
n = Frequency.
The maximum magnetic flux equals the flux density,
in the present case 30,000 lines per square inch, times
the cross-section of the core in square inches; that is,
N = 30,000 X 2.25 = 67,500 lines.
Substituting in the above formula.
np _ 4.44 X 67,500 X Tp X 60
1Q8 ' anC*
n =
110 X 108
= 611 (approximately)
p 4.44 X 67,500 X 60
To arrive at even numbers make the total primary turns
612, or 306 turns on each core. The number of secondary
turns will be
Secondary voltage 10
Primary voltage X p = TTo X 613 = 56
or 28 turns to (be coil. The arrangement of the wind-
ings on the core is shown in Pig. 3. The corners of the
core .ire slightly rounded and it has four segmental
blocks of hardwood on four sides. The wood should be
well filled with shellac or insulating paint. The inside
diameter d of the secondary coil figures 2.12 in., as il-
lustrated in Fig. I; but as the corners of the core are
rounded, the inside diameter will be taken as 2 in.
From a magnet win- table it will be found that No. 10
wire has 8.54 turns to the inch and. as the length of the
coils is ; in., there is twice the space needed for the sec-
ondary winding „f 28 turns per coil. Therefore, it will be
Pig. i. Illustrating Method of Detf.kminint; Inside
Diamktki; of Secondary Coif
necessary to wind a cord the diameter of the wire parallel
"Mb it, to make a good job. The secondary winding should
I"' wound on a stiff insulating tube of 'the required di-
ameter; a piece of mailing tube will do. Before winding,
the tube should be thoroughly impregnated with insulat-
ing compound. For winding, the tube should be slipped
on a wooden arbor and placed in a lathe. When the
winding is in place the ends should be secured with cord
and wrapped with two or three thicknesses ol oiled cloth,
then wrapped with webbing and painted or shellacked.'
The ends of the winding should be cut off about an inch
from the core and flexible cord for the leads soldered on
and the joints taped.
Each primary coil consists of 306 turns of No. 19 wire;
there arc 22.77 turns to the inch and 22.77 X ~ =
159.39 turns to the length of the coil, which will make
about two layers for the primary coils. Flexible leads
are soldered to the primary winding and the whole is
bound lengthwise, thai is, inside and out, with webbing
and thoroughly painted. The coil should now be wrapped
with oiled cloth.
In building up the cores the sheets of iron should be
cut in different lengths. For example, referring to Fig.
2, cut half the sheets 7% in. long and half 10.5 in. and
assemble them with alternate strips, long and short: then
securely rivet the bundle. The yokes should be assembled
m like manner, which will allow the ends of the yokes
and those of the cores to mortise. One yoke and two 'cores
can be assembled and riveted, the coil slipped on and the
second keeper placed in position and riveted. The coils
should be so connected that the current flows in opposite
direction- m (he two legs.
The F'l; loss should be checked after calculations are
made and if too great, should be decreased by increasing
the size of the wire. This is a cut-and-try method to
secure the proper size of wire.
264
POWER
Vol. 41, No. 8
JtLSSt for Ftl&E&
[In the issue of Jan. 19 we asked for accounts of stu-
pidity m a class with those printed in the same issue un-
der the heading, ••Some Original Ideas." Following are a
few of the best stories which have been received. —
Editor.]
The following method of laying up three 18-ft. bj 72-
in. return-tubular boilers was at least unusual. After
pouring 18 gal. of cylinder oil through the top manhole,
the boilers were filled and then slowly drained. The man
in charge expressed an opinion that the boilers would be
protected from rust indefinitely, in which I presume he
was correct. The removal of the oil, however, upon re-
suming operations will call for another original idea. —
Ernest A. Tichenor, South Connellsville, Penn.
A student taking an examination in steam engineering
was asked what a "self-supporting stack"' was. He
answered that it was one which paid the interest on
the investment by using natural instead of fan draft.
A turbine test man was sent to the stockroom for putty
and came back lugging a 50-lh. keg of white lead and
asked for some dry putty, as the new stuff was too soft.
[This last joke looks "putty"' thin to us. — Editor.]— R.
Blumenfeld. Brooklyn. N. Y.
In a small town a short distance from Xew York City
a town meeting was called to consider alterations to the
steam-heating system in the high-school building, as it was
not working properly. A member of the school board
made a report, with recommendations, which was severe-
ly criticized by one of the Board of Aldermen, who
made the following statement:
"The heating plant was not installed correctly in the
first place, for the boiler is in the wrong end of the build-
ing, as it is now in the south end and should have been
placed in the north end, because steam in pipes will flow
better from north to south than from south to north."
Thi above statement was actually made in public, and
if desired, I will furnish proof of its authenticity. —
W. .1. Armes, Norwood, Mass.
During the recent cold spell I noticed a large bulged
place on the brass plunger of a deep-well pump temporar-
ily out of use for repairs, which resembled a snake alter
swallowing a large toad. On examining the piston it was
found to he hurst a distance of' five inches, due to water
leaking past the threads on the rod and freezing solid.
On the same repair job it was necessary to take down a
part of the discharge line which contained a three-inch
gate valve. On removing the valve it was turned around
several times. Anyone would have thought all the water
had been spilled out. but such was not the case, and the
result was a hurst valve, but it was not noticed and wa>
put back in the line.
When all was apparently ready the valve outside was
opened to the tank pressure, and a large spray of water
issued from the ruptured valve, of which a bystandi r
and myself soaked up a good supply. The young man
thought it was from over-pressure, and explained it to the
fireman by saying that he saw it open up like a clam
shell.— W. H. Corbin, Sharpies, W. Ya.
jayes* Quaaelel,~Acftsinig? M©!ffiliey=
A quick-acting and convenient monkey-wrench differ-
ing from the usual design has been placed on the market
by the Bayer Steam Soot Blower Co.. of St. Louis. The
ordinary thumb-nut is replaced by a sliding collar which
may be moved up and down the handle to operate the jaw.
The motion of the collar is transmitted to the screw of
the wrench by means of a pin attached to the collar and
fitting into a spiral groove in the screw rod. Moving
. ollar toward the outer end of the handle closes the jaws
and vice versa. When the collar is up against the mov-
able jaw the wrench is wide open. In this position the
Bayer Quick-Acting Moxkey-Wrexch
wrench may be slipped over a nut. A pull on the collar
will adjust the jaws, and pressure to do the turning may
he applied at the same instant.
Including the cap at the end of the handle, the wrench
is made up of live pieces : The handle and stationary jaw.
the movable jaw. the collar, screw roil and cap. The handle
i- a solid steel forging of elliptical shape with a recess
for the screw rod. The latter is thus protected so that
!here is little opportunity for bending it or getting it out
of alignment. The collar is easy to move, and altogether,
the wrench is a most convenient tool.
Heat Value Calculation — The combustion of a given ele-
ment always results in the generation of a fixed amount of
heat. Thus, when a pound of pure carbon burns completely
(forming CO=). 14,600 B.t.u. is produced. Consequently, the
heat value of carbon is said to be 14,600 B.t.u. per lb., which
is the unit of weight almost universally used in this country.
When a pound of pure carbon burns incompletely (forming
CO), only 4450 B.t.u. is produced. But if, in turn, the resulting
2} lb. of CO, which is a combustible gas, is burned, 10.1">0
additional B.t.u. is liberated, making the total heat produced
equal to 14,600 B.t.u., just the same as though the pound of
carbon had burned completely (to COs) in the first place.
Hence, the heat value of CO is
10.150
= 43:>0 B.t.u. per lb.
2.333
The heat values for carbon and hydrogen were established
by experiment and hence probably are not absolutely exact.
In fact, some authorities give values for carbon as low as
14,220 and as high as 14.647, and for hydrogen as low as
61,816 and as hisrh as 62.032, but 14,600 and 62,000 are the
most widely accepted and used.
February 23, 1915
P 0 \V E R
265
Step>=IB)esvriiajg Accsunrmmllsiftoir f©s»
By W. R. Bankhead
In the power plant at the Puget Sound na\ v yard
there is a 500-kw. vertical turbine, the step bearing of
which is supplied with oil by tun duplex pumps .capable
of delivering oil at 800 lb. per sq.in. The oil passes
through a baffle before reaching the bearing, which re-
duces it to a pressure sufficient to support the weight of
the moving parts. This pressure varies from 155 lb. at
no load to 190 at lull load. These pumps also supply oil
to the other bearings of the turbine and to a tank for a
gravity system.
The step bearing has been burned out several times on
account of the failure of the oil pressure. The pumps
originally had no governor nor air chamber to steady
the pressure. A failure for one second would cause the
bearing to begin to cut, and the machine had to be shut
down for repairs.
An accumulator of some kind was needed, and as the
space was limited it was decided to install a vertical steel
tube, into the bottom of which the oil should be pumped,
compressing the air in the top of the tube, which acts as a'
spring to force the oil out to the step bearing in case the
oil pump failed. This form of accumulator is cheaper
to build than a weighted-piston type, costing only about
one-half as much.
The tube is 11 ft. long, 12 in. inside diameter, and V2
m. thick, and is made of seamless rolled steel. In each end
of the tube -"',-in. steel heads were welded by the oxy-
aeetylene process, and when tested to 2000 lb. hydrostatic
pressure it was found to be tight ; this is necessary to
To Step
Bearing
Fig. 2.
CM Check Valve
From Pumps
Details of Alarm System
make such an accumulator successful. There is a cheek
valve between the pumps and the accumulator and a gage
Fig. 1. Vertical Accumulatob A in Limited Space neab On. Pumps
266
r u w e h
Vol. 41, No.
between the accumulator and the baffle. The gage is
so fitted that when the oil pressure falls below 600 lb.,
a gong which can be heard all over the engine room an-
nounces the drop in pressure.
Fig. 1 shows the location of the accumulator A. The
baffle B is at the base of the turbine foundation, and 0
is the check valve between the pumps and the accumula-
tor. D is the connection to the compressed air. The
high-pressure oil gage which closes the electric circuit
is shown at G. The accumulator was first filled with com-
pressed air at 100 lb. to insure a good supply and to re-
duee the quantity of oil necessary. Fig. "2 shows the de-
tails of the alarm system.
The primary purpose of this accumulator was to guard
against a Midden failure and to give the operator warn-
ing in time to start another pump or to shut down the
turbine. For 1? min. after the pump is stopped the ac-
cumulator will maintain a pressure sufficient to support
the step bearing with the forced lubrication system still
on, and for 23 min. to the step bearing only.
In practice it has proved better than was expected,
as it keeps steady pressure and acts as a governor for
the pumps, which can be run on a wide-open throttle.
The turbine has been running almost continually for
eight months day and night without any step-bearing
trouble whatever.
Instead of being an uncertain and unreliable machine,
the accumulator has made this turbine one of the most
dependable in the plant, and we have been able to "for-
get"' the step bearing.
KtitimiE t]
o^aif<
.BnaninK
liv II. WlEGAXD
SYNOPSIS — Tells in a simple and thorough way
tiow to set the valves of a four-valve engine I" run
either over or under.
In setting the valves of a four-valve engine the usual
method of placing the engine on the center is used.
A tram may be used to facilitate marking the different
positions of the crosshead. crank, etc.
Turn the engine, which is supposed to run over, until
the crosshead is at the point of the crank end relea>c II.
Fig. 1, which shows the positions of the crosshead, crank,
throw of eccentric and rocker-arm in diagram form. A~
the crank-end exhaust valve must be line to line' with the
port to open and, when the crosshead is at C, begin to
close for compression, it is evident that the rocker-arms
must be in the same place at these two points of cross-
head or crank position.
Therefore, it is not necessary to connect the valves until
the right position of the eccentric has been found. Set
the throw of the eccentric near the angle of advance point
B, and mark the position of the rocker-arm line by a
line across the pin and hub or hub and pin-boss; then
fasten the eccentric with the setscrew or a false key and
turn the engine over to the crank-end compression point
Op
Fig. 1.
C. The throw of the eccentric will now be at D and the
rocker-arm. instead of returning to /•'. will go beyond it
to n. The eccentric must therefore be turned back until
the rocker-arm reaches point H, central between F and Gf.
To accurate!) locate //. divide the distance between
the marks on the hub and pin or pin-boss. The throw
of the eccentric is now at J and the rocker-arm at //.
with the crank and crosshead at ('. Turned over to R,
the throw of the eccentric will be at E and the rocker-arm
will have moved to L and back to H. The crank-end ex-
bausl valve can now be set line to line and the rods and
valve lexer put in the desired position. The latter may
be fastened with a false key and a line drawn across the
face of the lever and the valve stem to mark the position
Fig. 2.
of the valve. The crank must now be turned back to M,
the point of head-end compression, and the head-end ex-
haust valve connected and set line to line with the port.
The eccentric will now be at X, the rocker-arm at 0.
Turned over to E or head-end release, the throw of the
eccentric will be at Q, the rocker-arm at 0. the cross-
head at E. and the valve will begin to open for release.
The eccentric and valve levers can now be marked for
keyseating and the rods locked and marked for length.
To set the admission valves, place the governor in its
midway position and turn it so that with the weights
"in," the throw of its eccentric is in line with that of
the exhaust eccentric; then fasten it there. Next turn
the shaft to its crank-end center and throw the weights
of the governor out. 'With the valve-gear rods set at
their proper lengths, set the crank-end admission valve
line to line with the port and fasten the lexer to the stem.
Now throw the weights in and note how fa r the valve
has opened. The designer will give the lead and the lap
of the valve at dead-centers. Suppose this valve should
have ' i-in. lead and 3V,-iu. lap, it must move ^% in. by
throwing the weights out or in. If it does not move
enough the governor must be advanced, or set back if the
February 23, 1915
POWER
2c;
valve moves too much. The two large circles, Pig. 2, rep-
resent the greatest and the leasi travel of the eccentric.
The diameters of the two smallest circles, Pig. '.'. represent
the greatest and least trawls of the valves, the nexl large:
One the bore of the wheel ami the (wo large circles the
positions of the eccentric with governor weights in ami
out. The arc AH drawn from the center of the pivof
pin P marks (he path of the center of (In- eccentric and
Fig. 3. Positions of Valves
the two dotted lines drawn from the center "I' the wheel
mark (he throw of the eccentric at its greatest and at its
Leasi travel. It will he seen that the position of (he gov-
ernor is given by the distance between (he two eccentric
circles or (he amount of valve motion at dead centers;
also that the throw of the eccentric at leasi travel i>
opposite the crank and that it is impossible for the valves
to open if they have lap at dead-center, while the governor
weights are out. After finding the correct governor po-
sition (he crank-end valve may lie set to its proper lap
and the engine turned over to the head-end center for set-
ting the head-end valves in the same way.
Turn the engine over one revolution with the weights
out to make sure that the admission valves do not open,
then turn it one revolution with the weights in to note the
point of admission to the point of cutoff and (o see that no
negative lap occurs from overtravel. which would, happen
>H E
OP
Fig. 4.
if the valve in Pig. ;! were turned further in the direction
of the arrow. By decreasing the governor travel the neg-
ative lap may be reduced if it is not over T'j; in.; if more,
a new valve is usually required. The governor, valve
lexers and rods can now be marked as described.
To reverse this engine set (he exhaust valves by turn-
ing (he shaft to /,', Fig. 4. the point of crank-end re-
lease, when the engine is running under. Then (urn the
eccentric in the running-over direction until the crank-
end exhaust valve is line to line with the port. The throw
of the eccentric will be at J, the rocker-arm at // and.
turned over to (', the throw will In' at K, with the valve
again closing for compression. The head-end exhaust
valve will he line to line at E and < '.
Tin weight-arms of the governor and the springs ami
links require changing to throw the eccentric (he other
way. The key has to he taken out and the governor turned
in the direction of running "under" until, with the en <,.■■
on its crank-center and the governor weights "in," the
Fio. 5.
crank-end admission valve has ^4-in. lead. Fasten the
governor and turn the engine under to the head center
ami the head-end \al\e will show the game lead. Now
throw the weights out and examine the lap: if it is not
quite right the governor may have to he moved a little
cither way. The engine i- reversed and the new key-
ways may lie marked.
Fig. 5 shows the position of tin' eccentric for running
under and also the keyways for running the engine in
both directions.
W\ .1. A. EOHTON
An operator complained (hat his induction motor was
overheating and .Mated that it was free from grounds; (hat
the trouble was in the motor itself because the one that it
had replaced operated normally up (o the time of its re-
placement; and that his service voltage was 550 to 600.
He added thai one phase took hardly any current, while
the two other phases did all of (he work.
As the replaced motor had operated normally, the un-
balanced symptom suggested a reversed internal connec-
tion. Accordingly, a winder was sent to inspect the end
connections and to change (hem if necessary. Xo changes
were needed because the connections were all right, dust
after trying the motor and before the oil switch had been
opened, the winder approached the connections with the
intention of taping some hare ones. The operator hastily
opened the oil switch and warned him that the line volt-
age was 550 volts and that one leg was grounded through
a fault. The winder was no general trouble man, but
he had looked at the aameplate of the motor and, as In-
had seen I tO m>Hs marked on it. he failed to see any good
reason why a I 10-volt motor should be operated on a 550-
volt circuit. Wrong voltage was (he only trouble.
A- far a- the unbalancing of (he phases was concerned,
what had seemed to be an unbalanced condition was due
to the fact that the operator, in using a single ammeter
on a three-phase circuit, failed to note that the current
had changed while changing his meter from one leg
of the circuit to the other. The three legs had not been
read under like conditions of the load.
268
POW E B
Vol. 41, X,.. B
?2° Cc
>y Co^uumo
Something of an event in the history of the American
Society of Mechanical Engineers occurred Saturday. Feb.
13, when the council approved the proposed Boiler I
finally submitted by the committee appointed for that
purpose. Probably no one appreciated what an important
undertaking this would prove when the suggestion Ma-
first made that the society draft standard specifications
for the construction, equipment and use of steam boilers
with the hope that they might be made the basis of uni-
form legislation in the several state-. Certainly no one
anticipated the monumental task it would develop into,
nor the keenness of the interest that would be enlisted
from so many quarters, many of them unexpected. One
member of the council in moving a vote of thanks to the
committee characterized the code as the greatest single
piece of work that the society has ever done.
In spite of the opposition that was manifested, espe-
cially in the early part of the committee's work, by the
various industries which feared the code would tend to
injure their business and were jealous lest others might
obtain advantages over them in one way or another, all
of these conflicting interests were finally reconciled: the
council approved the code unanimously and even from
outside of the society there is practically no objection to
the code in its final form.
It is reported that immediately it became possible to
secure a copy of the code in its approved form, one was
rushed to Indianapolis to be embodied in a bill to be pre-
sented, and it is believed that the State of Indiana will
adopt the code entirely in the very near future and that
eight to a dozen other states are all ready to follow suit
before many months have passed by. The council voted
not to discharge the committee, but to continue it in-
definitely with the idea that it may be made a permanent
committee by action of the society, with power to revise
the code from time to time whenever that may be war-
ranted due to advances in the arts. This committee was
augmented to include not only the original members. I nit
the later advisory committee of eighteen members.
While the existence of the committee dates back to
Sept. L5, 1911, when it was appointed during the presi-
dency of the late Col. E. I). Meier, "to formulate stand-
ard specifications for the construction of steam boilers
and other pressure vessels and for the care of same in
service," most of its real activity has been shown during
the past year.
The council's instructions were to formulate a model
engineers' and firemen's license law. a model boiler-in-
spection law and a standard code of boiler rules. The
necessity of properly constructing, installing and inspect-
ing boilers was naturally to receive consideration and the
make-up of the committee was appropriately chosen. The
accompanying portraits show the original members.
The chairman. John A. Stevens, at the age of 21 was
granted an unlimited engineer's license for ocean steam-
ship— highest class. He resigned as first assistant en-
gineer of U. S. M. s. -St. Paul" in 1893 to take the
position of chief engineer of the Merrimac Manufactur-
ing Co. in Lowell. Mass. For eleven years he made all
power-plant layouts and estimates for this company. In
L90"i tie was : b d by the Governor a member of the
Massachusetts Board of Boiler Kules and served two
terms of three years eai b, during the first of which the
Massachusetts rules were formulated, which have since
been the pattern of so many other states. Since 1909
he has practiced consulting engineering.
The other members of the committee included two
professors of engineering, two boiler manufacturers, a
steel-plate manufacturer and an insurance engineer.
Prof. I!. C. Carpenter is professor of experimental en-
gineering at Sibley College, Cornell University, Ithaca.
X. Y., a consulting engineer with extensive practice and
experience in the boiler field, the author of ■"Experimental
Engineering" and other engineering books, and is fre-
quently called as an expert witness in legal cases con-
cerning boilers.
Prof. Edward F. Miller is professor of steam engi-
ne; at the Massachusetts Institute of Technology,
Boston, Mass.. and similarly qualified by experience. His
special services on the committee were in connection with
- ifety-valve specifications and mathematical formulas.
Col. E. D. Meier, since deceased, was the president and
chief engineer of the Heine Safety Boiler Co., St. Louis.
Mo., and a builder of water-tube boilers.
Richard Hammond, president of the Lake Erie Engi-
neering Works. Buffalo. X. Y., brought the experience
of a maker of marine and tubular boilers to the commit-
tee. His advice was especially helpful in relation to rules
concerning large-diameter boilers and stayed surfaces.
Dr. Charles L. Huston, vice-president and works man-
ager of the Lukens Iron & Steel Co., and also of the
Jacobs-Shupert TJ. S. Fire Box Co.. was particularly val-
uable to the committee as its special metallurgical expert.
tor he is one of the foremost investigators into the sci-
entific manufacture of iron and steel plate.
Finally, as the representative of the field of boiler in-
spection and insurance. William II. Boehm, superintend-
ent of the departments of steam boiler and flywheel insur-
ance of the Fidelity & Casualty Co.. New York, rounded
out appropriately the committee's personnel.
A (irst preliminary draft of the rules proposed after
consideration had been given to the rules then in force
in such >tates as had any, was prepared and distributed
among authorities qualified to criticise it and make sug-
gestions at the St. Paul meeting of the society in May of
last year. The interest aroused prompted the arrange-
ment for a public hearing in Xew York in the fall. Tin-
took place in September and another in October, after
which the code was revised and a third printing made
of the preliminary draft. The fourth printing was called
a Progress Report and brought formally before the an-
nual meeting in Xew York last December. The unusu-
ally extendi on which ensued has already been
referred to. Shortly thereafter there was a conference
with the boiler manufacturers' association at which it was
ed to revise the code at once while the suggestions
were fiesh in mind and submit the details to represen-
tatives of all organizations and interests who would be
affected by the proposed code. The result was the ap-
pointment of the following advisory committee:
February 23, 1915
P U \V E E
269
270
1' 0 W E K
Vol. 41, No. S
I>. S. Jacobus, advisory engineer, Babcock & Wilcox Co., New
York.
IT. H. Clark, general superintendent of motive power, Balti-
more & Ohio R.R., Baltimore, Mel.
H. H. Vaughan, assistant to vice-president, Canadian Pacific
Ry.( Montreal, Canada.
A. L. Humphrey, vice-president and general manager, AVest-
inghouse Air Brake Co., Wilmerding, Penn.
Karl Ferrari, Erie City Iron Works, Erie, Penn.
H. G. Stott, superintendent of motive power, Interborough
Rapid Transit Co., New York.
I E. Moultrop, assistant superintendent construction bureau,
Edison Electric Illuminating Co. of Boston, Mass.
W. F. MacGregor, superintendent of experimental department,
J. I. Case Threshing Machine Co., Racine, Wis.
Richard D. Reed, H. B. Smith & Co., Westfield, Mass.
M. F. Moore, assistant to president, Kewanee Boiler Co., Ke-
wanee, 111.
SJ. F. Jeter, supervising inspector, Hartford Steam Boiler In-
spection & Insurance Co., Hartford, Conn.
Thomas E. Durban, general manager, Erie City Iron Works,
Erie, Penn.
F. W. Dean, consulting engineer, Boston, Mass.
William F. Kiesel, assistant mechanical engineer, Pennsyl-
vania R.R., Altoona, Penn.
Arthur M. Greene, Jr.. professor of mechanical engineering,
Rensselaer Polytechnic Institute, Troy, N. Y.
Charles E. Gorton, Gorton & Lidgerwood Co., New York.
Elbert C. Fisher, vice-president and general manager, Wickes
Boiler Co., Saginaw, Mich.
C W. Obert, associate editor, American Society Mechanical
Engineers, and secretary to the Boiler Code Committee,
New York.
The work of revision has continued without interrup-
tion, since December 15, except for Sundays and holidays
including both day and night sessions. After so tedious
a grind it is naturally very gratifying to the hard-worked
committee that its efforts have been successful and the
report received by the council. For its part the council
and all the members of the society, and engineers and
others outside of the society too, for that matter, should
and do feel their obligation for the earnest work of the
men engaged on it. Is it too much to say that humanity
generally should honor these men, for their efforts are
certain to result in decreased loss of life and property
from boiler accidents?
The valves are of the double-seat type and the disk work-
ing between tin1 seats is self-seating, which prevent leak-
age due to dirt deposited on either disk or scat.
The filter chests arc the same as in the single type of
filter, each divided into an inlet and an outlet chamber
A new type of Blackburn-Smith feed-water filter and
grease extractor, having twin bodies controlled by a sin-
gle set of inlet and outlet valves, is built by James Beggs
& Co., 38 Warren St., Xew York City.
A plant carrying a varying load, or one which operates
twenty-four hours per day, requires a filter having con-
siderable flexibility as to capacity, and one which would
permit of the cleaning of one part while the other was in
operation. If such a filter were of such size that either
side alone could carry the regular load, then the two
sides could be thrown in during the peak load, and so fil-
ter the water at all times without interference by the
necessary cleanings. This filter, Fig. 1, is designed to
meet such conditions.
The turning of both valves to one limit bypasses the
corresponding body, and the other body is bypassed up-
turning both valves to the other limit, thus permitting
the alternate operation and cleaning of either side. The
combined operation of both sides, as would be desirable
during the peak load, is accomplished by turning the
valves to mid-position.
The filter is made up of a number of parts, so that
breakage or disarrangement of any particular section
does not necessitate tin disi ontinuance of all filter service.
Fig. 1. New Twin Filter
Fig. 2. Section through the Filter
by a partition carrying the filtering cartridges. Fig.
2 is a sectional view. The opening of the filter for clean-
ing is facilitated by the use of a cover held by swing
bolts. A crane witli a turnbuckle lifts, swings and holds
the cover during cleaning.
Cast Iron— The average weight of cast iron is taken at
450 lb per cubic goot, or 37.5 per sq.ft., one inch thick.
February 23, L915 POW E B 271
iiiiiiiiiiuiii ilium lumimiiiiiiiiiiiiii inniiiiiii u imiiiuiiiiiiiiiu iiuiiiinii mm mini iiimiiiiu urn miiiiiiiiini urn n i iiiiiiiiiiui m i i minium i ss
(Oiauo
Tlh© Boilles3 Cod©9© aoC©inmir5m©imce=
College graduation exercises are significantly called
"Commencement." To be sure, Commencement marks
the completion of the students' college course, but the be-
ginning of their serious or useful life. On page 268 we
report the Boiler Code's "Commencement." Its course
of preparation is completed and it has obtained the de-
gree of A. S. M. E., which in this case is added before
its name instead of after. A great work is done, but
another great work is just beginning, without which all
the labor of compiling the code would amount to naught,
for until the states or municipalities adopt it into their
laws and, indeed, until the laws are enforced no real good
will be accomplished.
It must be "ratifying to those who have given them-
selves m> unselfishly to the task of getting the code in
shape, at no inconsiderable expense of time, money and
effort, to find many states and cities already eager to
avail themselves of this expert assistance in getting
proper statutes on their books regulatinir steam boilers.
This great movement to promote the safety of boiler
operation has started auspiciously. As stated in the ar-
ticle referred to, Indiana has already prepared to apply
the code and it may even be a part of this state's laws
before this issue of Power reaches its readers. Indiana
will thereby have the distinction of being the first to
adopt the code after its approval by the council of the
American Society of Mechanical Engineers. Wisconsin,
however, stole the march on all her sister states by adopt-
ing it before its completion, in the law which went into
effect January 1. 1915, for this law provides that the code,
as soon as approved, shall become a part of it. Penn-
sylvania and Tennessee have departments already estab-
lished, administered by the police authority, which prom-
ise to adopt the code, and Ohio, now operating under an
excellent set of laws, has intimated her intention to re-
vise them to conform with the uniform code. Active
work is also being taken up in New Jersey and Florida,
and the prospects for other states following suit in the
near future are excellent.
To speed the good work of bringing the code to the
attention of the law makers a legislative committee has
been formed, representing three bra&ches of the boiler-
making industry. Its member.- are: Isaac Barter, Jr..
of the Babcock & Wilcox Company, representing the
American Boiler Manufacturers' Association; Thomas E.
Durban, of the Erie City Iron Works, representing the
National Tubular Boiler Manufacturers' Association:
and II. P. Goodling, of the Farquhar Company, repre-
senting the National Association of Thresher Manufac-
turers. Thus the water-tube, lire-tube and portable boil-
er interests have united to bring about with all possible
dispatch that condition which will be so much to their
advantage — uniform requirements in all localities, so that
their product built to meet one standard set of specifi-
cations may be used in any part of the country without
modification.
That I'iiwei; takes a keen satisfaction in this wave of
reformation goes without saying. It will not imitate the
daily newspapers which delight in attempting to appro-
priate the credit to themselves whenever a cause they have
championed triumphs. While it is only fair to claim
that no single institution ha- so consistently and persist-
ently and for so long a time urged the need of proper
laws to safeguard the handling of steam boilers as has
Powek. to which its pages for many years back bear wit-
ness, it suffices in that the much looked-for end i- now
in sight, and we are -hid to bestoM the credit where credit
is due. We honor ourselves in saying "well done" to
the men who have finally crystallized our cries and those
of many others, that there should he laws, into these
definite recommendations that these are the laws that
should be. With tins change of text we shall continue
to preach the doctrine and plead for the adoption of the
A. s. M. E. code.
asa
The Mayor and his advisers are bending their efforts
to centralize the licensing of buildings, electrical work,
engineers and firemen, etc., under one head, namely, the
present Bureau of Licenses. As far as the Boiler Squad.
which now performs the function of Licensing engineers
and firemen and of inspecting boilers, is concerned,
the proposed plan is to allow it to continue inspecting
boilers, while men from the Si paid would be assigned
to the Bureau to examine applicants for engineers' and
firemen's licenses.
Engineers of the city have been alarmed because they
understood that all of the functions of the Boiler Squad
were to be exercised by another department. Because the
present work of the Squad is satisfactory, a change was
not looked upon with favor. But the change as proposed
by the Mayor's committee is really of little significance as
far as the engineers and firemen are concerned. One or
two bills covering the function of licensing of various
men and kinds of work in the city have been introduced
in Albany, but it i< too -non to tell just what dispo-
sition will be made of them. If passed as originally writ-
ten the Boiler Squad will become defunct.
It must be admitted that the Police Department is not
the logical bod}- to administer the work of inspecting boil-
ers and licensing engineers. The real solution of the ques-
tion is the creation of a state board to conduct such work.
This does not necessarily mean that local boards could
not exist contemporaneously, as we point out editorially
in this i-
The Boiler Code Committee of the American Society of
Mechanical Engineers in its report just completed, has
made quite complete recommendations on uniformity of
boiler construction. Probably, befon ?erj long, a sup-
272
P 0 AV E E
Vol. 41, No. 8
plenaentary report embodying recommendations as to 1 1 1; *
uniformity of boiler inspection and of the licensing of en-
gineers anil firemen will lie presented. These recommen-
dations will lie scientific. They will lie based upon all past
experience in such work and will embody the best of all
that demonstration has proved good. They will lie satis-
factory tn all nf tlie various interests involved.
The Boiler Squad has been guilty of disreputable acts
in the past. It is likely to go wrong again at any time,
and those interested would again be confronted with the
old conditions. If there must fie local boards in New
York and Buffalo, the two cities that have combated a
state law the hardest, lei them have them, but they should
conform to the regulations of the state hoard.
It is not too soon for engineers and owners in New-
York who are interested in their own welfare and in
public safety, to create sentiment favoring a state law-
embodying the recommendations of the American Society
uf Mechanical Engineers as to uniformity in construction,
inspection and licensing.
m
Sttafte dirndl ILocail Himspecftaoim
DepaiipflsffiKeir&tts
In states where some of the principal cities are already
provided with departments for inspecting boilers and ex-
amining and licensing engineers, efforts to pass a state
law are hampered by the opposition of local politicians
and officials, who fear the loss of the patronage and po-
sitions which go with the municipal ordinance. There is
also to be dealt with the Home Rule sentiment, and the
natural reluctance to give up a successful local adminis-
tration for one administered from the capitol, which would
have less direct contact with local men and conditions.
But the state-wide law need not involve the abandon-
ment of the local systems. Most of the state laws either
exempt from inspection boilers which are under the care
of boiler-insurance companies authorized to do business
in the state, or, better, accept the findings of inspectors
of such companies after such inspectors have been ap-
proved by the state department having charge of boiler
inspections, thus becoming pseudo state officials, although
in the pay of their respective companies. In this way the
-tale department has a record of all boilers and is as well
assured of their satisfactory condition as though they
were inspected by men paid by the department itself.
The same principle may well he, and in Wisconsin is,
extended to municipal departments. The local board goes
on making its own inspections and examinations, granting
its own certificates, keeping it- own records, and collect-
ing its own fees, but in addition reports to the state de-
partment, which is thus able, in connection with its own
work in those parts of the state which have no local sys-
tem, to keep a complete record of all the boilers and engi-
neers in the state and to exercise some supervision over the
whole. The state hoard may, for example, adopt a code
of boiler rules, such as that recently completed by a
committee of the American Society of Mechanical Engi-
neers, the requirements of which would lie enforced by I lie
local and insurance, as well as by their own inspectors.
This would result in uniformity of practice, not on 1 \ as
between different parts of the same state, but, it is hoped,
as between the states themselves, for state boards would
probably avail themselves of the expert work which lias
been expended upon the production of this code, and all
adopt practically the same requirements. An association
of the heads of state departments could be a clearing house
for information deduced by the investigations and ex-
perience of each, and by recommending revisions of the
code as the advisability of such revisions develop, main-
tain substantial uniformity throughout the nation. And
the local inspectors would be a part of the system and in
line for advancement to the positions of larger responsi-
bility and emolument which it offers.
February 20 the greatest world's fair to date opened
its gates. Our leading article this week is an extensive
account of the Exposition, covering somewhat its general
features, but more particularly such as will especially in-
! eii^t the engineering field. This is the first of a num-
ber of articles which we expect to present, dealing more
in detail with the exhibits with which our readers will
be concerned, and in the fall an account will be given of
the International Engineering Congress, which likewise
will lie the most notable that has occurred. •
The Exposition stands as a commemoration of the
greatest piece of engineering in history — the connecting
of the Atlantic and Pacific by a canal across the Isthmus
of Panama, the benefits of which to mankind will continue
down the centuries. The Exposition can hardly have so
far-reaching an effect, but if it repeats the experience
of like undertakings of the past it will mean much in
furthering the progress of all lines of human endeavor
by showing what has thus far been accomplished, and
thereby indicating the directions in which continued im-
provement is to be desired.
A fair of this kind is, naturally, of most direct ad-
vantage to those who can visit it, and no one who has the
opportunity to get to San Francisco should neglect it. It
is a liberal education in itself. Next best is to read the
descriptions of it which will appear in the periodicals
of all kinds. This, too. is an opportunity not to be over-
looked. Present-day achievements in the illustrating and
printing arts bring within the means of all the ability
to gain much of the good that would come from an actual
trip to the Pair. But seeing the Fair and reading about
it both require a disposition on the part of the individ-
ual to avail oneself of the opportunity to broaden one's
knowledge.
More indirect, but of certain advantage to the most
indifferent, is the influence which such an exposition has
on the world at large by stimulating a striving for better
things in all lines — art, business, profession or calling of
any kind — in consequence of the examples set by the ex-
hibits and in other ways. No one can visit such an
impressive collection of the world's best without coming
away with new ideas to apply, and these in turn inspire
those who do not go.
Innumerable endless chains of uplift are started with
every such demonstration of modern achievement. The
greater the undertaking, the greater the effect. If argu-
ment were needed it could be continued ad infinitum to
justify all the stupendous labor and expenditure involved
in the Panama-Pacific Exposition. Thanks be for the
inspiration that conceived the idea and the energy which
carried it to fruition !
February 23, L915 po \\- ].- g
Kiniii iiiniiii iin am inn iiiiiiiniiiiiiii ilium mini , ,
273
iimiiiiiii i .iii. .11,, iiuiiiiiiiiiiiiiiiuiiiiiiniii iii lining
©F2°(
pomKoieinio
■■■" ■ niiiiiiiiiiiraiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiimunin i niiiiiiiiiiiin muggm g
.'iniiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii i iiiniiii mini
iilllillllllliillin n
Costl of Stteam
H. L. Strong's article on page L33 in the issue of Jan.
under the above heading, strikes an important note.
Every engineer is interested and anxious to know how
much it costs to make steam in the other fellow's plant,
but the mere statement, that A's -team costs 25c. per thou-
sand pounds 'lues not tell it all. However, it may be
used as a basis for comparison and a standard method of
arriving- at tins cost should be used. The statement should
contain the following items : Coal, lb. at ;
Water, gal. at ; Power for Electric-Driven
Auxiliaries; Labor; Miscellaneous Expense; Mainte-
nance: Fixed Charges. The first three item- are self-ex-
planatory.
Under "Labor" should be charged supervision, fore-
man, fireman, ash- and coal-conveyor operators, boiler
cleaners, ashmen and shovelers, helpers and laborers, ami
all other labor, aside from maintenance, incident to opi r-
ating the station.
"Miscellaneous Expense" takes care of oil, waste, etc.
'•.Maintenance" should include labor and materials re-
quired to maintain in proper condition buildings, stokers,
conveyors (ash and coal), boiler-room auxiliaries, p
and fittings, feed pumps, electrical apparatus, and all
other tools or apparatus used in the boiler room in con-
nection with making steam.
Under "Fixed Charges" should be charged depreciation
of buildings and equipment, insurance (boiler and fire)
and taxes.
The sum of these items gives us the total cost of produc-
ing steam. This sum divided by the net amount of steam
rated, from and at 212 deg. F., and multiplied by
1000, gives the cost per thousand pounds of steam, from
and at 212 deg. F. -Net" -team i- the steam produced
by the boilers which is available for power, etc It is the
total feed water less steam lost by blow-down and that
used by boiler-room auxiliaries, or the amount registered
by flow meters on the outlet from each boiler, less the
steam used by auxiliaries. From recur,],- of steam pivs-
-ure and feed temperature it is a simple matter to reduce
p) pounds, from and at 212 deg. F.
After following the above form or an equivalent and
arriving at the cost of steam per thousand pound.-, there
are three important items to he considered before the costs
in different plants are comparable. These are (1) cost
Of fuel, (2) load factor, and (:!) equipment.
(1) Coat of Fuelr—li the cost ><( the coal used in two
plants is known and the charges against cost of steam
are kept in accordance with the foregoing form, it is a
simple matter to adjust the charges and determine what
the total cost.- would he if the fuel costs were the same.
For instance: A hums 2000 tons of coal per month, at
S4 per ton and his steam costs 28c. per thousand pound-,
if hi- coal cost him $3.50 per ten the total charges for the
month would he $1000 less and. consequently, the cost per
thousand pounds of steam would he correspondingly
lower.
, Load Factor— The character of the load on a
boiler plan! has considerable to do with the cost of out-
put. A plain whose load is steady, with -mall fluctua-
tions, such as a central lighting and power plant, can
produce -team cheaper than, say a plant supplying an in-
dustry where -team is used for driving engines or tur-
bines, for drying ovens, for miscellaneous manufacturing
purposes and for testing manufactured apparatus, under
which conditions it may be necessary to carry hanked fires
under one thousand horsepower or more of boilers. Jo
order to keep coste comparable, the coal used for banking
should be kept account of separately from that used for
loaded boilers. Only the coal used for actually producing
steam should he charged to the cost of steam. This hank-
ing, or stand-by, coal should he charged to the depart-
ment- responsible, and should not he charged to one boiler
plant when making cost comparisons with others.
(3) Equipment— There is no way of bringing a va-
riety of equipment to a standard basis. However, if the
other two factors are made equitable, then, if there is
much difference in the cost of producing steam in two
plants, it is fair to claim that it is due to equipment and
management, and the plant which shows the cheaper
production should he given the credit for having the more
efficient equipment and organization.
C. W. Howard.
Erie, Penn.
e§aia§|
Under the a hove caption, in your editorial in the issue
of Jan. 26, you say all coal mined must or should be used
as fuel. Your argument is good as far as all coal is con-
cerned, hut if the substance delivered at the plant eon-
tains 15 per cent, or more of slate, then the only apparent
remedy for this condition is for the consumer to protect
himself by the B.t.u. clause in his contract. In the plant
of which I have charge we buy all our coal on the B.t.u.
basis, and since we adopted this method (three years ago i
we show a saving of from 10 to 30 per cent. As to cost
of analysis, it is small compared with the saving effected.
<»ur contract reads $2.20 per ton (2000 lb.) (nut ami
slack), coal to test 13,400 B.t.u. per pound (100 either up
or down not to be taken into consideration), moisture
not to exceed 2 per cent., ash not to exceed 10 per cent.,
samples to be taken with a 2-in. pipe from each load as
delivered: part of each sample to he put in a can ami
sent to a chemist satisfactory to both parties, on the thir-
teenth and twenty-seventh of each month: consumer to
pay for the analysis, which is $3. 150 for each sample, or
$6.60 per month. There are coal companies that refuse
to consider any contract that has this clause included in
it. which goes to show that it is a good thing lor the
consumer.
In January of last year there was a shortage of coal
in this city, and dealers took advantage of that condition
and boosted the price 50c. per ton, and delivered anything
that looked like coal. Of course we got the same'grade
row e i:
Vol. 41, No. 8
of coal that tlic other plant? did, but we were protected
by our B.t.u. clause and instead of paying $2.70 and some-
times higher, we paid sl.i 15. The plant consumed 264
tons that month, which if it had stood up to the guarantee
of 13,400 B.t.u. would have vest us $2.20 X 264 =
$580.80, hut on account of low B.t.u. the price went down
to $1.'! 15 X 264 = $460.68, or $114.12 rebate.
Xow. suppose we had been like the other fellow and
were paying *vJ.70 per ton. we would have paid $3. TO X
•Ml = $"i 12.80 for that same coal that cost us $1.1 15 per
ton, ot $252.12 more than we actually paid. You must
admit that this is a good proposition for the consumer,
your employer. If the coal runs above the guarantee
of 13,400 B.t.u. you can well afford to pay the premium.
To .-um the whole matter up. it places the consumer
in a position where he tan get just what he pays for and
pays for just what he gets.
In times gone by the eoal game has been in the hands
of the dealer, hut a B.t.u. contract evens up the game and
gives the plant owner an equal show.
O. Newton.
Lakewood, Ohio.
8
Several changes had been made in the equipment of a
small refrigerating plant, including the addition of a
compressor the size of the old one. The new machine
did not produce the expected gain in refrigerating ca-
pacity; in fad, when run alone on the load it failed to
do the same work as the old compressor. It was decided
that the Minion [j u was too small to serve the two ma-
Aufo mafic Check
Valve
Suction
i
Com phi ssoe I Ionnectioxs
chines, so a duplicate line was put in. Chi improved
matter- but little.
The suction gage on the new machine registered 8 lb.
lower than the one on the old compressor when running
and would increase 3 to I lb. after the machine was shut
down. There was no ter available, so the in-
i rease was ascribed to inaccuracy of the gage. This com-
pressor ran much warmer than the old machine.
An automatic check valve was provided in the suction
line, as shown. One day when the machine was started
the engineer was surprised to hear a hissing sound in the
valve similar to that madi bi steam passing through a
throttled valve, lie found the bypass open and closed
it as it should he in normal operation. This stopped the
Doise, hut did not satisfy the engineer, for he correctly
reasoned that if there had not been a considerable differ-
ence in pressure on the two sides id' the check valve there
would have been no hissing sound. lie noticed by this
time that the suction gage indicated 10 lb. lower on
tin- machine than on the old one. which was 2 U). greater
than it had ever been before; the machine was also hotter
than usual.
The valve .1 had been closed when he took charge, and
he hail been told by several who were supposed to know
that it was to lie kept closed. lie opened it a few turns.
and immediately the machine began to pound heavily.
He closed the valve-, and after a few revolutions the ma-
chine ran normal.
The engineer reasoned that there must have been an
accumulation of liquid in the suction line hack of the
check valve, and when he opened the valve A this opened
the check valve wide, and the accumulated liquid was
swept into the machine. He decided to try again, but
first he shut off the liquid line to the expansion coils and
pumped down until the machines were running hot so as
to he sure to prevent slugs of liquid remaining in the suc-
tion line. Xow he opened the valve A gradually. The
suction gage jumped from 10 lb. lower than the other
gage to 5 lb. above, the machine cooled to the same tem-
perature as the other, and the clattering of the valves
that had always been present was silenced.
The trouble was in the check valve. This valve is in-
tended to shut off the suction pressure in case of accident
or blowout on the machine or discharge line. It depends
on the head, or discharge pressure, to keep it open. The
valve .1 hihng shut, there was little pressure in the pipe
leading from it to the check valve, and consequently the
check valve was nearly closed, which throttled the flow
of gas to the machine. There was a welcome increase in
ity. and the new machine now does as much as the
other.
Thomas (1. Tiu'kstox.
Chicago, 111.
s£
Part of our boiler plant consists of four 90-in. return-
tubular boilers rated at 400 hp. each and frequently de-
veloping as high as 700 lip. as indicated by the flow me-
ter-. Induced draft is used, and the coal burned per
square foot of grate averaged, until recently, about 20
lb. One of these boilers has a concrete setting, which in
other respects is the same as for the other three boilers,
which are brick set. The furnace was lined with fire-
brick and the bridge-wall was of the same material, but
the combustion-chamber walls were bare concrete. These
walls were approximately "2 ft. thick and had a 2-in. air
nine. I have no information as to the mixture, but ap-
parently it was about 1:3:5 cement, sand and crushed
-tone.
The boiler has been in service twenty-four hours per
day for about three-fourths of the time, for about ten
years. The furnace lining has been renewed repeatedly,
but nothing was done to the setting until a few mo
when it was found that the combustion-chamber
walls ha.! wasted away nearly to the air space: in fact.
we cut into the air space in cleaning away the burned
•See "Power." Dec. 15. 1914, p. S40; Jan. 12, 1915, p. 62; Jan.
26, i>. 131, and Feb. 2. i>. 169.
February 23, L915
I'D W E I!
275
material. The only practicable repair was a brick lin-
ing, which was accordingly put in. A new concrete Lining
could have been pul ill if there hail heen sutliejeut time
to allow the concrete to se1 or harden before using it.
In other respects the setting is sound except for two or
three old cracks. These boilers have not all been in the
same length of time, but the two nearest the age of the
concrete-set one have hail all or part of the eombustion-
■ hamber linings renewed. The worst fault with concrete
to he the difficulty of repairing, when that becomes
necessary ami tin- example seems to indicate that Eor
boilers operated moderately a concrete setting with a fire-
brick-lined furnace will last as long as the boiler.
11. L. Stbong.
Yariuoutln [lie, Maine.
(CsiS'Jb'iiflSpeftSoinv TV ©-via lb He
In connecting up. lor emergency use on gasoline,
a small gas engine that hail been operating on natural
gas, considerable trouble was experienced at first in
getting satisfactory operation. The engine was >till to
he operated normally on natural Lias ami was piped so
that it could be switched from one fuel to the other by
changing valves. The gasoline carburetor was connected
to the air suction pipe as shown in the sketch, the other
branch of the air pipe having a meter cock in it. By
.losing the meter cock ami the natural-gas valve and
Carbureter- ■ ->-_
;j
Section through Mixing Chamber
opening the gasoline supply to the carburetor the engine
could he run on gasoline: and by shutting off the gasoline
supply and opening the meter cock and gas valve it could
be run on natural gas.
In running on gasoline it was found necessary at lir-t
to give the carburetor needle valve one full-turn opening
and after about a half-hour's run the engine would begin
to cough, backfire, and slow down. Then if the supply
were shut off for a minute it would pick up again and
run along all right for about another twenty-minute
period, when the backfiring and slowing down would
recur. The trouble lav in the fact that the gasoline.
having to travel quite a distance from the carburetor
through the air pipe and the chamber A to the cylinders,
would not all stay in the gaseous form, hut would partly
liquefy and form a little pool in .4. The engine would
draw from this pool as well as from the carburetor, and
would get too rich a mixture and start to backfire and
slow down.
A small hole was drilled at B with the idea that
air suction through it would help to volatilize the gasoline
which collected at the bottom of .1. This helped matters
somewhat, hut still the operation was not uniform.
The trouble was finally remedied by connecting one
end of a flexible metal tube to the air intake of the
carburetor, the other end being attached to q "stove"
around the engine exhaust pipe at its hottest point.
This gave the carburetor hoi air, and the gasoline re-
mained in a volatile condition throughout its passage to
the cylinders. The operation was then uniform and
satisfactory, and the best running point of the carburetor
needle valve was found to he one-half turn instead of
one turn, as previously.
I). \. McClinton.
Pittsburgh, Penn.
Commenting upon the letter of Mr. Weaver in the
Dee. 15 issue on "Emery around a Dynamo," I believe
that if his rules and advice were generally followed it
would lead to trouble ami give repair men plenty of bus-
iness. The use of emery on either commutators or brushes
should he condemned, as even with the utmost care par-
ticles of emery are likely to become embedded in the
mica, brushes or commutator bars and cause no end of
trouble by cutting and -coring the bars or brushes.
The use of oil on a commutator i> another bad practice
that is far too common. If it is necessary to provide a
lubricant for the commutator a brush with a small per-
centage of graphite should he used. Oil is hound to gel
into the mica and in time will help carbonize it. caus-
ing short-circuits between the liars: which, in turn, will
cause the brushes to spark and the commutator to pit and
wear.
If a commutator is badly worn or out of true it should
be turned off, and if properly done, there will lie no need
to use a file. After turning, the final finish is obtained
by the use of fine sandpaper and any burrs of copper left
from the turning can be picked or cut out with the point
of a knife or tool. Should the commutator not be in had
enough condition to need turning, it can he trued by
••stoning.'' Sand-stones for this purpose can he obtained
in any desired grade and in various shapes; a handy size
being 2x'2x t in. in a medium-coarse sand.
In stoning generator commutators the brushes should
he lifted and the stone applied with a fair pressure. In
the case of motors in operation it can he accomplished the
same as sandpapering. After stoning, a finish is ob-
tained by the use of fine sandpaper, and then all dust
should be blown off with a bellows or hose and the com-
mutator wiped with a dry rag.
After turning or stoning a commutator it is advisable
to fit the brushes. This is done by placing them on the
commutator under pressure and running a piece of fairly
coarse sandpaper hack and forth under the brush with
the sand side toward the brush. This will grind the
brush down to a surface that conforms to the curvature
of the commutator.
There are many different grades of brushes for use for
different services. It sometimes occurs that the liars
of a commutator are soft and wear faster than the mica,
resulting in high mica. An abrasive brush on a commu-
tator of this sort will cut the mica and the bars at an even
276
P O W E II
Vol. 41, No. 8
rate, or in a case of this kind ir is good practice to under-
cut the mica slightly. Proper undercutting will not
cause excessive brush wear. Undercutting is usually ad-
vocated on high-speed machines and is rarely resorted to
on Low- or moderate-speed machines, unless, as has been
said, the mica tends to remain high between the bars.
After the commutator of a machine is in good condi-
tion it will only be necessary to wipe it off occasionally
with a dry rag. The brushes also should be wiped off oc-
i asionally, but in the majority of cases should not be re-
moved to do so, as there arc few holders in use that will
permit of the removal of a brush and its exact replace-
ment relative to the commutator surface. Lifting the
brush slightly off the commutator allows wiping it off.
Bex. J. Oppexheim.
Bound Brook, X. J.
The furnace changes and results obtained, as described
in the article of this title by -Morgan B. Smith, appear-
ing- in Power, Jan. 19, p. 92. are similar to what was
done by Westinghouse Church Kerr & Co. under the
writer's supervision at the plant of the Detroit Edison Co..
at Defray, Mich., in 1009. 1910 ami 1911, which work
was referred to in the discussion of Dr. D. S. Jacobus"
paper on "Tests of Lam..' Boilers," in the 1911 Proceed-
ings of the American Society of Mechanical Engineers.
In the furnaces at Del ray the stoker arches were cut
back and the division walls between the stokers were at
firs! constructed so as to conic no higher than the fuel
lied. Later, we went "a step further, eliminating the
division walls between the stokers, moving them together
-<> a> to present a continuous urate surface across the
furnace, and substituting a short flat suspended arch for
the customary construction. By these changes all brick-
work other than the inclosing walls was removed from the
furnace-, the troubles with the arches were eliminated
ami better combustion condition- were obtained.
It is interesting to note that the results obtained by
us some years ago in the furnaces at the Defray plant are
confirmed by those reported by Mr. Smith at this later
time from the use of a similar construction.
H. 0. Pond,
Westinghouse Church Kerr & Co.
New York City.
ss tUh© ©SI Ball
The work of the power engineer is now primarily con-
cerned with the diminution and prevention of losses more
or less secondary in character. One of the best examples
of this kind that have come to the writer's attention
is that of the lubricating oil for one of the largest
Xew York City office buildings. When this plant was
originally installed a high-grade cylinder oil costing about
fifty cents a gallon was used, and the oil caught by the
separators allowed to run into the sewer.
The first economy was the connecting of all oily drips
to a common receiving tank, from which it is pumped
To two centrifugal oil separators. These separate the
oil and water, the oil being returned to the filters and
then to the oiling system. The water is returned to
the feed-water heater and from there to tiie boilers.
The next step was the purchase of graphite lubricators
to be used with the cylinder lubricators on the engines,
pumps, etc. The graphite lubricators are filled with a
paste made of graphite and cylinder oil and connected
in between the cylinder lubricator and the steam pipe.
Tin- oil from the cylinder lubricator in passing over the
graphite picks up enough to form a mixture of graphite
and oil. which lubricates the cylinder. As the lubrication
i- done li\ the graphite, it is possible to use a much lower
grade of oil. because the latter ads principally as a carry-
ing agent for the former. In the case under discussion it
was possible to use a 35c. oil. which, with the cost of the
graphite, reduced the cost from 50c. to under 30c. per gal.
The separators in handling the oily drips discharge
the water and oil as formerly, and also catch and retain
the graphite on the plates. These are cleaned every week
and the graphite is used in the boilers in place of
compound. This system has been in operation for some
seven or eight years, and the oil is used over and over
without showing any reduction in lubricating qualities.
The make-up oil required costs less than $250 a year, and
it i- calculated that the savings effected pay for the cosl
of the equipment about once every 11 months. The cosi
of the separators was about $500 each and the graphite
lubricators *1."> each. The equipment for this change cost
less than $21 ><><") and returns a profit of fully 100 per cent.
W. L. DriiAxn.
Brooklyn, X. Y.
CTh§j.jmg|edl Great? IPLafta®
Changing the gear ratio of a motor drive is not a wise
procedure unless the person making the change knows
the probable result. A change that will slow the arma-
ture may increase its load beyond safe limits, and a
change that will make the armature run faster may in-
crease its speed beyond the tensile limit of its band-wires.
The folly of random gear changes on direct-current trac-
tion vehicles of various kinds can be testified to by some
crane and car operators. Induction motors, while simi-
larly subject to overloads incident to decreased gear ra-
tios, offer the assurance that they will never exceed syn-
chronous speed very much, even when driven by the grav-
itation of their connected load, and will never reach syn-
chronous speed when driven by the current alone. Above
synchronous speed, alternating-current motors have a
tendency to load themselves by generation.
There are times when changes in gear ratio may be
productive of improved operation. An operator of a
huge locomotive turntable had a gasoline engine installed
on one end of the table. The engine did well until traf-
fic increase demanded faster motive power. He then sup-
plemented it with a three-phase induction motor, in-
stalled on the opposite end of the table. The motor
handled the work twice as fast as the engine had, but for
several reasons, including variable voltage, variable fre-
quency and abusive handling, it began to give trouble by
heating. Ammeters showed that the motor was never
overloaded except at starting, but that it was starting a
large proportion of the time. To ease the starting, the
gear ratio was increased 20 per cent. This stopped all
trouble without materially affecting the speed of oper-
ation, because the armature ran faster.
J. A. Hoktox.
Schenectady, X. Y.
February 23, 1915 POWEB ■.',;
llllllllllllllllllllllllllllllllllllllllllillllllllllllllllllllllllllllllllllllllllM Illlllll I Illlllllllll 1 Hill ........_
unqf^mrnes o
'imeiral Imifterestt
i .■ ;■ ... i '-,i'rs
Highest Temperature of Peed Water with Open Heater —
Why cannot the temperature of water in an open feed-water
heater be raised higher than 212 cleg. P.?
H. R.
Because the water is under atmospheric pressure, and 212
deg. F. is the temperature at which water is converted into
steam at that pressure.
Relative Transmission l>> Rubber and Leather It. -Hint; —
What thicknesses of rubber belting are equal for transmis-
sion of power to single and double leather belts?
R. C.
When made of cotton duck weighing two pounds per yard
coated with best India rubber, 3- and 4-ply rubber belting is
usually taken as equal to single leather belting and 5- and
6-ply as equal to double leather belting.
Total Heat of Steam — What would be the total heat of a
pound of steam at gage pressure of 100 lb. per sq.in., with a
barometric pressure of the atmosphere of 28.5 in. and tem-
perature of 62 deg. P.?
S. G.
One inch of barometric pressure at 62 deg. F. is equal to
0.491 lb. per sq.in., and therefore the absolute pressure of the
boiler steam would be
100 + (0.491 X 28.5) = 113.99
or practically 114 lb. absolute, and according to Marks and
Davis' steam tables, a pound of steam at the latter pressure
would contain 1188.7 B.t.u. above 32 deg. F.
Wetter Steam Requires More Feed Water — When our
boiler is pushed to its highest capacity, why is it that the
water level gradually goes down, but as soon as the damper
is partly closed and with the feed pump operating at the
same speed, the boiler-water level comes up again?
C. J. P.
It is quite likely that when the boiler is forced wetter
steam is generated, and although doing the same amount of
work, greater weight of steam of the lower quality is dis-
charged from the boiler, thereby requiring replenishment of
feed water in excess of the rate required for maintaining the
proper water level with the damper partly closed.
Regulation of Oil Burners — In the use of oil burners how
can the best regulation of the oil. steam and air supply be
determined?
A. C. S.
The best regulation of oil burners is obtained by observa-
tion of the top of the smoke-stack and the color of the fire.
When the burner valves and the air supply are correctly
adjusted, the flame is a bright white and there is no smoke.
When the supply of steam is too great, steam will appear
around the burning spray and will be discharged from the
smoke-stack. If too little steam is being used, atomization
will be incomplete, and if the air supply is insufficient the
color of the flame will be red, and incomplete combustion
will be indicated by the discharge of smoke from the stack.
Advantages of Extended Front Boiler Setting — What are
Che advantages and disadvantages of an extended front set-
ting as compared with a flush front setting for a horizontal
return-tubular boiler?
W. C.
The principal advantages of the extended front are the
employment of a shorter brick setting and obviation of pas-
sage of the furnace gases direct to the front smoke connec-
tion, as is likely to occur with a flush front setting, from
settling of the fire-door arch or other causes of leakage of
the joint between the fire-door arch and the under side of
the boiler. The disadvantages are that with a low setting
the front extension may be in the way of the fireman, and
also that the extended front does not present as good an
appearance as the flush front.
Depth of Front and Back Conneetions for Return-Tubular
Boilers- — What should be the depth of front and of back
smoke connections for horizontal return-tubular boiler set-
tings?
G. R.
The depth of back connections for any size of boiler should
be not less than 24 in., so as to allow sufficient space for
examination and expansion of tube ends in the back tube
sheet, and for boilers larger than 66 in. in diameter the depth
of back connections should be not less than 28 in. Greater
depth is advantageous for equalizing the distribution of the
heated gases to all tubes of the boiler. Front connections
should be of such form and depth as to permit of an easy
sweep of the gases to the uptake. The minimum depths
should be 12 in. for boilers up to 54 in. diameter, 16 in. for
boilers 60 and 66 in. diameter, and 18 in. for boilers 72 and
7^ in. diameter.
Operation of Centrifugal and of Inertia (Governors — What
is the difference between the operation of centrifugal and of
inertia governors?
J. E. B.
In centrifugal governors a change in position of the gov-
ernor parts is effected solely by a change of centrifugal force
resulting from a change of speed. In inertia governors, re-
volving weights are so arranged that when the engine wheel
is accelerated, as by removal of load, the inertia of the
weights causes them to lag behind and assist centrifugal
force in adjustment of the valve gear for admission of less
steam, thus checking the speed, while if the speed of the wheel
is retarded, as by an increase of load, the momentum of the
weights causes them to surge ahead and assist the spring
action of the governor to attain a position of parts that will
increase the speed. Therefore, inertia governors are prompter
than centrifugal governors, and also may be more powerful
and closer in regulation.
Air Required for Burning a Ton of foal — What volume of
air should be supplied for burning a ton of coal?
B. S.
Most fuels require between 11 and 12 lb of air per pound
of fuel, according to their analyses, and it is usual to con-
sider that 12 lb. of air will be required to burn each pound of
coal. But to make sure that each atom of carbon will meet
with an abundance of oxygen, it is necessary to admit an
excess of air to the furnace, the amount depending on the
force of the draft. With natural draft at least twice as
much and with forced draft at least l'v, times as much air
will be required. As one pound of air at 62 deg. F. has a
volume of 13.14 cu.ft., then for burning a ton (2000 lb.) of
coal the air supply should be not less than
12 X 2 X 13.14 X 2000 = 630.720 cu.ft.
of air with natural draft, nor less than
12 X 1% X 13.14 X 2000 = 473.040 cu.ft.
of air with forced draft.
Loss of Water Level in Gravity-Return Boiler — What may
be the cause and remedy for occasional loss of proper water
level in the sectional boiler of a low-pressure gravity-return
steam -heating apparatus?
H. B. L.
The proper water level will not be maintained by auto-
matic return of the water of condensation to the boiler when
the temperature of steam in the pipes or radiators is so much
reduced by radiation of hea _iiat the pressure, plus the static
pressure of the return connection, is less than the sum of
the pressures required for overcoming pipe friction, and
opening the return check valve added to that in the boiler.
Under these conditions the water level may also become re-
duced by the water of the boiler backing up into the system
through leakage of the return check valve. The remedy is
to obtain higher relative pressure in the return water by
increasing the sizes of steam supply pipes or increasing the
static pressure of the return water by raising the level of
pipes and radiators or lowering the boiler.
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
2 ; 8
POWE B
Vol. 41, \u. 8
lastticitty SMmdl EmidlvUiFainic® ©f
By C. E. Stkombteb
In the present paper it is proposed to inquire into the
causes of steam-pipe failures by dealing: with about a hundred
reported explosions which have been attributed to fatigue and
to want of elasticity, though it may have to be admitted that
bad material and workmanship, including- injudicious or un-
necessary annealing, have occasionally either accelerated the
failures or have been their chief causes.
In dealing with this subject it will first be necessary to
fix on a standard of comparison for the fatigue stresses which
may have caused the failures: but in order not to complicate
this subject, and also because definite information is not
available, it will for the present be assumed that Guest's law
for steel also applies to copper, which means that the cir-
cumferential stresses in pipes, due to internal steam pressures,
do not affect the bending stresses which in the cases under
consideration have caused the fractures. Then, also, nothing
is as yet known about the influence of temperature on the
power of copper to resist fatigue stresses, though it is prob-
able that it has a weakening effect: but temperature also in-
creases the elasticity of copper, so that as regards deforma-
tions due to fatigue stresses no serious error will be committed
by leaving these two temperature influences out of account.
According to experiments the relationship between the
fatigue stresses (±S) and the number (X) of the stress cycles
(revolutions) which cause fracture is expressed by the formula
*S = Fl + C (10" -s- N)l
Here C is a constant depending on the nature of the ma-
terial and Fl is the fatigue limit of the material. Both Fl and
C have been obtained by breaking a number of samples by
fatigue stresses and marking off the test results on diagrams
in which the ordinates were spaced to represent (10" -s- Mi.
The test results were then found to lie on straight lines
which, when prolonged, cut the zero ordinate at the heights
El. which were then adopted as being the fatigue limits.
These tests could naturally not have been continued to an in-
finite number of revolutions, and there was therefore no ab-
solute certainty that this exterpolated fatigue limit was a
reality until by improved methods of testing this point was
firmly established. In other words, more recent experiments
have demonstrated the fact that this formula applies not
only within the range of previous experiments, say from two
thousand to twenty million alternations of stress, but also to
an infinite number. WShler's experiments, and in fact all
past experiments which have been examined, confirm the
above-mentioned formula.
Wohler's experiments confined themselves to steels, ex-
cept one series of tests on wrought iron, but they have been
extended by the author to embrace, at least as regards tor-
sion-fatigue tests, about fifty different qualities of steel and
steel alloys, cast and wrought iron, nickel, copper, aluminum,
phosphor bronze, magnalium. and other alloys, and in all
cases the test results harmonized with the formula, which may
therefore be accepted as correct. A matter of even greater
importance than the general form of the formula is that the
fatigue limit can now be expeditiously determined with
greater accuracy even than the static tenacity. In one case
its extreme values among eight test pieces cut from one
crankshaft differed by less than ±0.4 per cent, of the mean
value.
Unfortunately no bending fatigue tests have been made
on copper, but this omission will be made good in the near
future, and the determination of the fatigue stresses which
caused fractures in copper pipes will therefore have to be
based on deductions drawn from a few torsion-fatigue tests on
copper bars which are summarized in the following formula,
in which ± St. is the alternating shearing stress due to tor-
sion strains which cause failure at the nth revolution:
Copper bar as rolled * St = 5.4 + 0.37 (10" -S- N)
Copper bar as rolled * St = 5.6 + 0.51 (10* 4- Nil
Mean of above * St =5.5 + 0.44 (10« -s- N)l
Copper bar annealed in vacuo ± St = 2.55 + 0.87 (10" -5- N)S
Copper bar annealed and chilled in water * St = 2.69 + 0 97 (10" -4- N)i
It having been found that on an average the bending
fatigue limit for steel is about 60 per cent, higher than for
torsion, the last of the above torsion-fatigue limits may
reasonably be increased from 2.69 to 4.30 tons per square inch
for the bending-fatigue limit for copper, and as the same
comparative tests on steels show that the value of C for
bending is three and a half times as great as that for tor-
sion, the value of C=0.97 may be increased to 3.4 tons per
square inch and the formula for the bending-fatigue stresses
of copper is probably
= Sb = 4.3 + 3 4 (10" -=- X)i
As wrought-iron and mild-steel pipes are now largely used
on steamers, formulas for their bending-fatigue stresses are
of interest. Among the writer's own tests he finds the follow-
ing results for basic steel, which is the quality of which many
welded-steel pipes seem to be made:
TABLE I
Fatiirue Limit,
Tons pel Sq.In.
Values rif C
Tons per Sq.I
British ordinary
British dead soft. .
German ordinary
German dead soft
9 69
11 26
11.34
8 94
4 53
3 92
4 in
4 79
Mean for mild basic steel ....
10 31
4 33
"Paper read before the Institution of Naval Architects and
abstracted from "Engineering," London.
It will be noticed that the fatigue limit for the softer
qualities of basic steel, which contain about 10 per cent, car-
bon, are not necessarily lower than those for ordinary mild
qualities, which have about 40 per cent, carbon. This is due
to the presence of varying percentages of nitrogen, which
element has a tenfold greater influence than carbon on the
fatigue limit. The fatigue limit for cast steel is only a little
higher than the above, viz.. about twelve to thirteen tons per
square inch.
The formula for the bending-fatigue stresses of mild steel
may therefore be written
=t Sb = 10 30 4- 4 . 33 ( 10" -r- N l i
Only one set of bending-fatigue tests has been made on
wrought iron (by Wohler). The results can be expressed by
the formula.
=*Sb = 6 73 + 4 43 (108 -h Nil
Among the Board of Trade reports on steam-pipe failures
there are none which may be attributed to fatigue of mild
steel, but there are a fairly large number of failures of cop-
per pipes, of which a few are capable of being analyzed with
the help of the above formula. The following are the report
numbers of the failures in question — failures said to be due
to vibrations:
Straight pipes — Xos. 94S, 1113.
L-bends. like Fig. 6— Nos. 453. 854. 945, 95S. 1024, 1049, 1057.
1095, 1111. 1164. 1181, 1187, 1207. 1291. 1296. 1491, 1516, 1611,
1651. 1795, 1852, 1895, 1931.
U-bends. like Fig. 9, without central branch — Nos. 480, 1011.
1021, 1069, 1172. 11S5, 1313, 1426, 1435, 1501, 1922, 2105.
U-bends. with central main pipe at right angles to bend,
similar to Fig. 9 — Nos. 970.992, 1015, 1036, 1696.
S-bends and two L-bends placed at right angles to each
other— Nos. 657, 718. 749, 772, 775, 915. 1290, 1527, 1654, 1709,
1926. 1993.
Expansion bends with straight lengths — Nos. 767, 943, 1616,
17:'",. 1852, 1895. 1931.
The following failures are probably due to looseness of
the engine or the boilers:
Engine seating loose — Nos. 742. S33, 1013. 11«0, 1355, 1443,
1666, 1922, 1964, 2021, 208S. (In these cases it is presumable
that the movements were appreciably great and as numer-
ous as the revolutions of the engines, which on an average
may be assumed to be 60 per minute for six months a year.)
Boilers loose — Nos. 543. 72S, 1210, 1467. fin these cases it
is probable that the movements were large but few, and the
empirical rule for the fatigue stresses does not apply.)
Relative movement between boilers or engines and the
ship's structure — Nos. 1268, 1543. 1291. 2176.
Shaft brake and engine raced violently — No. 1216. (This
pipe had many bends, otherwise the stresses might have been
estimated.)
Most of the aforementioned cases cannot profitably be
analyzed on account of complexity of form and absence of
details. However. Nos. 958. 1049. 11S1 and 1954 of the first
group and Nos. 1355, 1543 and 2021 of the second group are
suitable for this purpose. The estimated fatigue stresses
which fractured the aforementioned ten pipes are contained
in Table II.
No allowances have been made for the internal steam pres-
sures and their temperatures, though with the exception of
February S3, 1915
P 0 W E R
279
2021, for which the steam pressure was 200 lb., the pressures
in all the cases were 160 lb.
Case No. 1954 deserves special attention, for the estimated
fatigue stresses are approximately equal to the static tenac-
TABLE II. ESTIMATED FATIGUE STRESSES UNDER WHICH
CERTAIN COPPER PIPES FAILED AFTER N REPETITIONS
Estimated
Assumed
Fatigue
Age at
Number
Stresses,
Report
Time of
of Revolu-
Tons per
Number
Fracture
lutions
(10«-rN)i
Sq.In.
Remarks
Failures due to Vibrations of the Engine
958 (1)
12 months
15,000.000
0 505
6.02
'ir,s (21
25 months
31,000,000
0.423
5.74
Port pipe
1049 (1)
2J years
40,000,000
0.397
5.65
1049 (2)
1 year
15,000,000
0.505
6.02
1181 (1)
10 years
150,000,000
0.285
5.27
1181 (21
24 hours
86,000
1 846
10.57
Heavy weather
8 J years
120.000,000
0 302
5.33
1954 (2)
4 hours
14,000
2 900
13.85
Engines racing
Failures <lu.- to
'.oosc Engine Seatings
1355
35 months
44,000.000
0 388
5.62
4 years
6U.0OO.IHKI
0 359
5.52
U-bend secured to
deck beam
3 years
45,000,000
0 386
5 61
Long bend
fry of copper. The fact that this pipe withstood these alter-
native stresses for four hours suggests either that the
adopted value of C = 3.4 tons per sq.in. per 1,000,000 revolu-
tions is too high or that the copper was of a harder quality
than usual. Among the 200 cases of steam-pipe explosions
reported on by the Board of Trade, only three have been
TABLE III (Figs. 1 to 5).
Estimated
Inclinations Estimated Displacements
a S x 4 y
Kg. 1 ... +MXL+EXI + J M X L» -s- E X I'
Fig 2 + J Y X L» + E XI + I Y X L> -s- E X I
Pig. 3 ... +|»MXI(v E X 1—0.571 M X If ■*■ tMXH'+EXI
F'B- 4 — 0.571 X XK'r + 0.356 XXIl'r -|XXH"t E X I
E X I E X I
I' ig. 5 . +YXR'-S-EXI -}yR»+EXI +i.VXK' + KXI
M is the external bending moment shown in Figs. 1 and
3; X is the external horizontal pull shown in Fig. 4; Y is
the external vertical pull shown in Fig. 5; E is the modulus
of elasticity, say 13,000 tons per sq.in. for wrought iron and
steel, 8300 for copper, and 4500 to 8000, or say 6000. for cast
iron; I is the moment of inertia of the section of the pipe
and is equal to (D* — d<) n h- 64, where D is the external and
d the internal diameter of the pipe; a, fx, and »y are the
acquired inclination and the displacement of the ends of the
pipe (see Figs. 1 to 5); Sb, the maximum bending stress for
any moment M, is % M X D + I, which expression can be
introduced in the formulas when the movements produced by
X and Y are known.
One application of these formulas can be illustrated with
the help of Fig. 6, which represents half a U-bend. Assume.
as was the case in Prof. Bautlin's experiments, which will
shortly be dealt with, that the flange A, which is the middle
of the bend, is a fixture and that a pull X is acting hori-
zontally on the flange C. Then the bending of BC is the same
as that in the curved pipe in Fig. 4, X being applied as in
£ L- *lxM
\< L, H
The Letters Correspond to Those ix the Algebraic Expressions in the Te.vi
found in which measurements of movements which may have
caused the failures are given.
Report No. 1467 mentions that the boiler rolled % in. Re-
port No. 1296 mentions that when getting up steam the length
between the two valves (no dimensions given) shortened by
0.47 in., and the difference of level between the two valves
altered by 0.44 in., the boiler top having risen ft in. as com-
pared with the ship's structure and the engine stop-valve,
which had risen Vs in. The history of this pipe is interesting
It was made of solid-drawn copper and put in service in
July. 1899; it cracked near its flange Jan. 17, 1900 (five and
one-half months' interval). The cracked end was cut off
;md replaced by a sleeve, which cracked nine hours after
lighting the fires. A new sleeve of thicker copper ( U in.)
was now fitted, which ran, say, from the end of February to
July 30. 1900 (about five months), and then cracked. A new
pipe with a larger bend was fitted (August, 1900), but this
pipe cracked (no date given). The crack was repaired and
the gland made workable. These several failures seem to
have been due, not to frequent movements associated with
the revolutions of the engine, but to steady stresses caused
by the difference of expansion of the boiler and engine, in-
tensified by the vibrations of the engine. No experimental
data as to the endurance of copper under these conditions are
yet available.
No. 1318 reports that the boiler top rose up ft in. and the
engine % in. due to the raising of the steam pressure, the
two boilers separated by % in., and the distance between
the engine and one boiler stop-valve was reduced by ft in.
In this case the explosion was due to imperfect brazing of
one of the flanges.
To understand the stresses which arise when pipes are
strained, the several possible deformations of straight and
curved pipes, as represented in Figs. 1 to 5, have been ex-
pressed mathematically in Table III.
that figure. The bending of AB is represented by the two
cases. Figs. 3 and 5, M being equal to XR and Y equal to X.
Then the acquired inclination of a of the flange B is ac-
cording to the third and fifth lines of Table III:
a= (%t RXXXR-H XR-) -H E X I = 2.571 X X R- H- E X I.
The displacement A of the flange C is the sum of the
displacement Jy of Figs. 3 and 5, of ix of Fig. 4, and of the
product of the inclination a into the radius R of the bend BC
•i=<XXR3-r 0.785 X X R' + 0.356 X X R3 +2.571 X X R3)
-r- E X I = 4.713 X X R3 H- E X I.
The bending moment at A is of course 2X X R, and this
is equal to SxI-=-y2D, where D is the external diameter of
the pipe. On replacing I by X2R X D -=- 2S, the stress S at
the flange A can be expressed in terms of the displace-
ment A:
S = AXDXEH- 4.712 R=
For copper, the value of E is about S300 tons per sq.in.. so
that for pipes of this material S = 1750 2> X D H- R:, and assum-
ing 4.3 tons per sq.in. as being the fatigue limit for copper, the
maximum permissible movement of half a copper U-bend
(Fig. 6) should not exceed
Ac = R= t 405 D
For steel and wrought iron E = 13,000, and therefore S =
2750 J X D -=- R2, and assuming the fatigue limit for wrought,
iron to be 6.75 tons per sq.in., we have
M = R- -f- 410 D for wrought iron
Assuming a fatigue limit of 10.3 tons per sq.in. for mild
steel, we have
A.
R-'
265 D
Thus a U-bend (Fig. 7) of S in. diameter and S ft. high
which forms part of a long length of pipe will take up the
following expansion movements without injury to itself: 1.10
in. if of copper, 1.40 in. if of wrought iron, and 2.20 in. if
280
P 0 AY E I!
II. No. 8
of mild steel. This last result agrees with experiment A in
Tables IV and V.
TABLE IV. PROFESSOR BAUTLIN'S EXPERIMENTS ON THE ELAS-
TICITY OF BENDS
Outside Diameters
Height. and Thicknesses. Moment of M.I.
Details of Bends In. In. Inertia I Millions
A. mild steel pipe 94 7 S.iX8.2X0.26 27.0 BIO
B. mild steel pipe 88.8 5.3X5.1X0175 2.65 80
C. cast-iron pipe 94 7 8.5 X 8.4X0 78 139.0 275
D. mild steel tod... 54.fi 3 14 square 8.0 240
E. mild steel rod. 62.5 3 14 square 8.0 240
Prof. Bautlin carried out some experiments on U-bends
shaped as shown in Fig. 8*. As the bends were not square
other but similar formula to the above had to be constructed
for estimating the displacement of the flange C. These are
recorded in the columns marked "Est." in Table V. The ob-
served displacements are to be found in the columns marked
"Obs." The modulus of elasticity of the cast-iron pipe was
7S70 tons per sq.in.
The formula for these bends is
\ = 17.27 X X R3 -f- E X I and S = 2, X D X E -=- 17.27 R=
It must not be overlooked that whereas in the previous
case (Fig. 7) the height of the bend is 2R, in the present case
(Fig. S) it is 3.414 R. The agreement for the mild-steel rods
between the estimated and observed displacements is satis-
factory, but pipes seem to be rather more elastic than was
expected. The discrepancies between the estimated and the
observed displacement for the mild-steel pipe A have been ex-
plained as being due to slight puckers on the insides of the
bends of the pipes. In part they are also due to the thinning
during the bending operation. Generally speaking. Professor
Bautlin's important experiments confirm the mathematical
estimates of the deformations of bent pipes, and these may
therefore be applied to the few exploded steam-pipes for
which the probable alternating stresses have already been
calculated. It is unfortunate for the present investigations
that the Board of Trade reports contain so little informa-
tion about those parts which, in the opinion of the reporting
surveyors, are not the direct causes of the explosions. Among
tons per sq.in., the relative movements of the two ends of
the pipe should by the formula be ± 0.3S in. In the longer
branch. L and R seem to be respectively 7". in. and 68 in. As-
suming the correctness of the previously found stresses of
± 5.74 tons per sq.in., the relative movements of the pipe ends
should be ± 0.25 in.
Report Xo. 1049 deals with another L-bend of solid-drawn
copper of 5ai in. external diameter. According to the sketch,
L and R seem to be respectively SO in. and 25 in. Assuming
the correctness of the previously found alternating stresses of
± 5.65 tons per sq.in. for the first failure after 2% years'
running, the relative movements of the two ends of the pipe
should be 0.049 in., and for the second failure after 12 months'
running the alternate stresses would be ± 6.02 tons and the
relative movements should be 0.051 in. The comparative
smallness of these relative movements is due to the rigidity of
the small bend, which was only five times as large as the diam-
eter of the pipe. In fact, the pipe probably acted as a stay be-
tween the engine and the boiler and restricted their move-
ments while being fatigued. Had the relative movements been
larger and the stresses more intense, the failures would have
occurred sooner, as happened in the following two cases:
Report No. 1181 deals with an L-bend of solid-drawn cop-
per 6% in. external diameter. According to the sketch, L and
R seem to be respectively 42 in. and 50 in. Assuming the cor-
rectness of the previously found alternating stresses of ±
10.57 tons per sq.in. for the failure, which occurred after 24
hours' heavy service immediately after previous annealing, the
relative movements of the ends of the pipe should be 0.27 in.
Seeing that the estimated alternating stresses during the pre-
vious ten years' running were only ± 5.27 tons per sq.in., the
relative movements of the pipe ends during this longer pe-
riod do not seem to have exceeded ± 0.14 in.
Report No. 1954 deals with an L-bend of sheet-copper 4.92
in. external diameter. According to the sketch. L and R seem
to be respectively 93 in. and 32 in. Assuming the correctness
of the previously found alternating stresses of ± 13.85 tons
per sq.in. for the new pipe, which failed during a run of four
hours in heavy weather, the relative movements of the ends
TABLE V. PROFESSOR BAUTLIN'S TEST RESULTS
Difference between two Successive Thrusts in Pounds
440 660 ■ 880
Estimated and Observed Displacement of Flange C. Inches
Est. Obt.
0^84 0^69
Est.
Obs.
Est.
Obs
0.30
0.68
1.42
0.10
0.19
0.24
0 30
ii ;:;i
Est.
,il,.
Est
0.60
Obs.
2.96
The elastic limit was reached with pipe A with a thrust of 1S09 lb.
about one hundred reports on steam-pipe explosions, which
it is believed were brought about by want of elasticity, the
diameters of the pipes and the thicknesses at the points of
fracture are given, but rarely is any mention made of the
lengths or the elasticities of these pipes, although these are
the determining factors.
For the purpose of this paper, these lengths, as well as the
radii of curvature, had to be approximately ascertained by
scaling them with the help of the diameters as sketched. It
is therefore possible that the dimensions which have been
adopted in the following calculations are not always correct.
U-bends (Fig. 9) with central branch do not seem to have
failed, and this form need not be discussed.
L-bends and simple U-bends (see Fig. 10). The following
formula for the displacement Sy in the case of L-bends and
2Sy for U-bends can be determined in terms of the horizontal
pull T and the bending moment M by combining the formula
in Table III for the cases represented by Figs. 1, 2 and 5. As
there is no pull X. and as the sums of the deflections of the
length L and the bend is zero, T can be eliminated and M ex-
pressed in terms of Sb. the maximum bending stress.
8y = 0.712 Sb X R= (L + 0 65 R) -h E X D (L + R>
For copper E = 8300 tons per sq.in., so that
Sy = SbR (L + ii i3Ri ± 11,600 X D X (I. + R)
This formula has been used in calculating the displace-
ments Sy for the following L-bends and 2Sy for U-bends. Sb
being the fatigue stresses which have been previously deter-
mined for the separate cases.
Report No. 958 deals with the two separate L-bends made
of electro-deposited copper of 5 in. external diameter hooped
with iron bands. The shorter length, in which, according to
the sketch, L and R seem to be respectively about 11 in. and
57 in., failed after 12 months' service. Assuming the correct-
ness of the previously found alternating stresses of ± 6.2
•Zeitschrift des Vereins Deutscher Ingenieure, 1910, Vol.
54. page 43. Also Mitteilungen iiber Forschungsarbeiten des
Vereins Deutscher Ingenieure, Vol. 96.
of the pipe should be ± 0.23 in. For the old pipe, which failed
after eight years' running under stresses of ± 5.33 tons per
sq.in., the relative movements should be ± 0.09 in.
Report No. 1355 deals with an L-bend of solid-drawn cop-
per 5.19 in. external diameter. According to the sketch, L and
R seem to be respectively 70 in. and 100 in. long. Assuming
the correctness of the previously found alternating stresses of
± 5.62 tons per sq.in., the relative movements of the ends of
the pipe should be ± 0.39 in.
Report Xo. 1543 deals with a U-bend of solid-drawn copper
4.94 in. external diameter. Judging by the sketch, L and R
seem to be respectively 16 in. and 46 in. long. Assuming the
correctness of the previously found alternating stresses of
± 5.52 tons per sq.in., the relative movement of the ends of
the pipe should be ± 0.26 in.
Report No. 2021 deals with an L-bend of solid-drawn copper
5.5 in. external diameter and 0.25 in. thick. According to the
sketch, L, and R seem to be respectively 6S in. and 42 in. As-
suming the correctness of the previously found stresses of
± 5.1 tons per sq.in., the relative movements of the ends of
the pipe should be ± 0.17 in.
X IBLE VI ESTIMATED INTENSITIES OF FATIGUE STRESSES AND
THE RELATIVE MOVEMENTS OF THE ENDS OF THE
FRACTURED PIPES
Assumed Estimated
Report Number of Fatigue Stresses, Fatigue Move
Number Vibrations Tons per Sq.in. ments. In.
Failures Due to Vibrations of the Engines
958(1) 15,000.000 =t 0.02
958 i -'i 31.000,1X10 * 5 74
1H49 ill 40,000, =■= 5.65
1019 121 15,000.000 * 6.02
11M 111 ... 15ii.iiihi.ih«i =1= 5.27
ll.sl (2) S6.000 =■= 10.57
1954(1) 120,000,000 ± 5.33
1954 (2) 14,000 ± 13. S5
Failures Due to Loose Engine Seatings
1355 44,000,000 ± 5.62
1543 60,000,000 * 5.52
2H21 45.0OIi.ikxi =e 5 01
0.3S
0 25
0 049
0.051
0. 14
0.27
0.09
0.23
n 39
0.26
0 17
February 23. 1915
P <» WER
281
These and the previous estimates are summarized in Table
VI. They are all based on the empirical formula which cor-
relates the fatigue stresses for copper and the number of their
lepetitions up to the point of failure. The experiments on
which it is based are comparatively few. and more compre-
hensive ones will shortly be carried out on a new fatigue-
testing machine which is nearing completion; but seeing that
the results of fatigue tests with mild steel are consistent,
tin' intended further experiments on copper will probably
merely confirm those already obtained.
Assuming the correctness of the empirical formula, then,
judging by the estimates contained in Table VI, relative move-
ments between engines and boilers of ±0.38 in. (see No. 958)
or more should be 'allowed for. These were associated with
fatigue stresses of ± 6.02 tons per sq.in., which exceed the
fatigue limit of ± 4.3 by 1.7 tons per sq.in. If these relative
movements of ± 0.38 in. had not exceeded ± 0.27 in., the pipe
would not have failed. Had the pipe been made of steel it
would also not have failed, for although its modulus of elastic-
ity is 13,000, as against S300 tons per sq.in. for copper, the
respective fatigue limits are 10.3 and 4.3 tons per sq.in., and
the maximum relative movement to wrhich such a steel pipe
would have submitted without injury would have been ± 0.43
in. Conversely, if a steel pipe of the above dimensions were
replaced by a copper one and the relative movements of its ends
were maintained at ± 0.43 in., then the fatigue stresses in the
copper pipe would be ± 6.77 tons per sq.in., or ± 2.47 tons
above the fatigue limit of ± 4.3 tons, and the copper pipe
would fail after 3,600.000 repetitions. This means that if any
copper pipe were to fail after experiencing 3,600,000 stress
cycles, which corresponds to 42 days' continuous running of
the engines at 60 revolutions per minute, and if it were to be
replaced by a steel pipe, this would last forever, and as most
of the pipes dealt with in the Board of Trade reports did last
longer than 42 days, the number of explosions would have
been correspondingly reduced if steel pipes had been used in-
stead of copper.
But — and this is the point which should not be overlooked
. — it is highly probable that the cast-iron valves to which these
steel pipes would have to be attached would have fractured at
an early date, because the resisting moments of steel pipes
are 1.56 times greater than those of copper pipes of the same
dimensions, and even copper pipes are occasionally strong
enough to fracture the cast-iron valves to which they are at-
tached, as is evident from the following Board of Trade re-
ports:
No. 389. A copper pipe with fairly large bends broke the
neck of the valve-chest to which it was attached.
No. 556. The thrust on an expansion-gland acting at the
end of a copper pipe as a lever broke the neck of the valve-
chest to which it was attached.
No. 971. A copper pipe attached to the end of a combined
expansion gland, stop valve and throttle-valve casing broke
the latter.
No. 1072. A copper pipe broke the cast-iron neck of a
steam chest to which it was attached. The other end of the
pipe formed part of an expansion gland which was attached to
the engine whose lateral motion was the cause of the fracture.
No. 1177. A copper U-bend between the boiler and its en-
gine acting on the end of a throttle-valve casing broke it.
No. 1572. The thrust of an expansion gland acting at the
end of a copper bend broke the valve-casing to which it was
attached.
In the following cases the pipes were of wrought iron:
No. 1230. A straight wrought-iron pipe between an ex-
pansion gland on the engine and a short cast-iron bend on
the boiler stop-valve broke the neck of the latter.
No. 1404. A straight iron pipe which ended in an expan-
sion joint broke the neck of the valve-casing to which it was
attached.
The following rather unusual failures may be due to bad
material, but seeing that they occurred both with sheet-cop-
per, solid-drawn and electro-deposited pipes it is not unlikely
that they were due to fatigue stresses. However, as all
these cracks are along the neutral line of the copper bends
where there are no bending stresses, but where the shearing-
fatigue stresses are maximum, it is not unlikely that these
alternating shearing stresses were relatively more intense
than the bending stresses near the flanges. It should also be
remembered that the fatigue limit for shearing stresses is
only ± 2.5 tons per sq.in.
No. 1231 deals with a sharp bend of sheet copper 3.55 in.
external diameter which cracked near the brazing line, which
is also the neutral line of the bend. The bend was eight
years old when it failed.
No.. 1262 deals with a bend of sheet copper 10.2 in. external
diameter which cracked near the brazing line like the above-
mentioned bend. This pipe failed after sixteen months' work.
No. 1662 deals with a bend of solid-drawn copper 6% in.
external diameter which failed along the neutral line after
three years' wink, when it was repaired and annealed, but
it failed again after seven years.
No. 1839 deals with an expansion bend of solid-drawn cop-
per 5.42 in. external diameter which failed along the neutral
line after nine years' work. Locally the tenacity was re-
duced to 5.6 tons with no elongation.
No. 1SS2 deals with a bend of solid-drawn copper 5.2 in.
external diameter which failed along the neutral line after
three years' work. It had probably been damaged locally
while being repaired. Locally the tenacity was reduced to 7
tons with 1.5 per cent, elongation.
No. 2110 deals with an expansion bend of solid-drawn
copper 5.4 in. diameter which failed along the neutral line
after four and one-half years' work.
No. 2140 deals with an expansion bend of solid-drawn
copper %V2 in. external diameter which failed along the neutral
line after six years' work.
No. 9S6 deals with a bend of electro-deposited copper 3%
in. external diameter which failed along the neutral line after
three years' work.
No. 13S3 deals with a bend of electro-deposited copper 4.8
in. in external diameter which failed along the neutral line
after seven years' work, close to a repair sleeve which had
been brazed on three months before the explosion.
No. 1736 deals with a bend of electro-deposited copper 3.8
in. in diameter which failed after one year's work. The ten-
acity was locally reduced to 12.5 tons with 5 and 8 per cent,
elongation.
No. 1770 deals with a bend of electro-deposited copper 5.4
in. in external diameter which failed after two years' work.
The tenacity was reduced from about 13.5 tons with 45 per
cent, elongation to between 9 and 10 tons with 5 to 7 per
cent, elongation.
No. 2163 deals with an expansion bend of electro-deposited
copper 6 in. external diameter which failed along the neutral
line after six years' work.
If. as seems probable, the above 12 failures (about 8 per
cent, of the total) were due to sheer fatigue stresses, which
are severest along the neutral lines of beams, they would
indicate that the bends had been subjected to more compli-
cated forces than have been assumed when dealing with the
other failures, but in the absence of any details about the
relative movements of the engines and boilers it is fruitless
to venture on any estimates, except to say that the formula
for torsion fatigue stresses should be applied to these cases
and that the stresses which are due to the internal steam
pressures should not under any circumstances be overlooked.
While studying those Board of Trade reports which seemed
to have a bearing on the present question it was noticed that
many copper pipes had failed shortly after being annealed, al-
though until then they had worked satisfactorily for years.
This experience would suggest either that annealing does not
remove the effect of fatigue stresses or that, if carried out in-
judiciously, it changes tough copper into a brittle material.
In the following list of reported cases the numbers in pa-
rentheses denote the periods in months which elapsed be-
tween the dates of annealing and of failure:
Pipes of Erased Sheet Copper. — Nos. 1922 (4), 1210 (5), 1021
(6), 2105 (17), 1011 (19), 1443 (23).
Solid-Drawn Copper Pipes — Nos. 1839 (%), 1926 (2), 1709
(5), 1327 (6), 1327 (8), 1993 (9). 11S7 (10), 2003 (21), 2110
(36), 1898 (48).
Electro-Deposited Copper Pipes — Nos. 1164 (3), 1501 (12).
970 (12), 1610 (19).
The average life of a copper pipe after being annealed
seems to be about one year for each one of the above three
groups, but as already suggested these cases do not prove that
annealing is or is not a remedy for fatigued copper. This
experience as regards copper does not apply to steel pipes.
As a safeguard against fatigue stresses in steam-pipes ex-
pansion glands are sometimes fitted, but they are not always
applied where wanted: they sometimes stick fast, and if badly
designed the pipes blow out of their sockets.
This latter class of accidents is illustrated in reports Nos.
779, 1702, 2246.
Pipes which stuck fast in their sockets and did not take up
the movements are to be found in reports Nos. 283, 1296,
1404, 1666, the last being a doubtful case.
In the following cases the thrusts of the pipes in the glands
acting on long bends fractured these near the roots or the
glands had stuck fast and the fractures were due to fatigue:
Nos. 556, 1113, 1187, 1207, 1230, 1343, 14S9, 1572, 1583, 1605, 1609,
1S52, 1916, 1978. These are mostly marine cases.
In the following cases the expansion glands neither pre-
vented the pipes from fracturing nor did they cause the
fractures: Nos. 169, 584, 971, 1011, 1035, 1056, 1072, 1109, 1172,
lis:,. 1214, 1264, 1398, 1461, 1515, 1537. 1556, 1747, 1771, 1899,
2<hh;. About half <>f these rases occurred on steamers.
282
POWE R
Vol. 41, No. 8
t£&e MsiiPirasmiSiEa M@dl.mil
At the annual meeting of the American Museum of Safety
held in the United Engineering Societies Building, 29 West
Thirty-ninth St., New York City, Feb. 10. 1915. the E. H. Har-
riman memorial gold medal for the American steam railway
making the best record in accident prevention and industrial
hygiene affecting the public and its own personnel during the
year ending June 30, 1914. was awarded to the New York
Central R.R. The award was marie to this road for its record
on the New York Central & Hudson River R.R. prior to its con-
solidation with the Lake Shore. The medal was offered by .Mrs.
E. H. Harriman to be awarded through the American Museum of
Safety. The committee of award consisted of: Arthur Wil-
liams, president American Museum of Safety, Samuel O. Dunn,
editor 'Railway Age Gazette"; Prof. Alexander C. Humphreys,
president Stevens Institute: Hon. Chas. P. Neill, former r. S.
Commissioner of Labor; and Hon. Edgar E. Clarke, member
Interstate Commerce Commission. The medal was received
on behalf of the railroad by Alfred H. Smith, president. The
silver medal was awarded to the operating department, and
the bronze medal to Dennis Joseph Cassin, who had been an
engineer on the Central since 1S67. He had never had an ac-
cident.
V
■mdlnmigi ©i
The formal Board of Trade inquiry in connection with the
terrible boiler explosion that occurred at the Thornhill Iron
& Steel 'Works, Dewsbury, on Aug. 10 last, causing the death
of eight men, and more or less serious injury to 17 others,
provides a lesson which it is to be hoped will be taken to
heart by every boiler attendant in the country, as to the -
criminal folly of interfering with the action of safety valves.
The facts of the case were very simple. The boiler, which
was one of eight at the works, all coupled together, was of
the Rastrick type, heated by the flames from iron furnaces,
and was normally worked at 55 lb. per sq.in.
The works were closed from July 31 to Aug. 10, and when
the boilers were started the engineer noticed steam blowing
off at the safety valves on No. 4 boiler, and without exam-
ining the stop valve or the pressure gage he assumed that
the escape of steam was due to some defect of the safety
valves — of which there were two loaded by levers and weights
— and tried to correct it, first by sliding the weights to the
end of the lever, and this proving insufficient, by adding a
weight of 50 lb., which, being still inadequate to prevent the
escape of steam, was supplemented with another 63 lb. As
a matter of fact, which was proved after the explosion, the
stop valve was shut and the boiler thus isolated from the
others to which it was supposed to be connected, and the
escape of steam was due to the steady rise of pressure in
the boiler, in which steam was being generated without any
outlet, and was being bottled up by the extra load on
the valves. There could, of course, be only one end to this
incredible madness, and that was reached about two or three
hours after the fire was started, when the bursting pressure,
which would probably be getting near 200 lb., was reached
and instantly converted the whole works into a heap of
ruins, killing or injuring nearly everybody in the place.
How anyone with a knowledge of boilers could be guilty
of such recklessness as to overload safety valves in this de-
liberate way, without seeing what the pressure was or mak-
ing sure that any steam generated had at least access to
the safety valves of the other boilers, surpasses belief, and
we can well understand the Board of Trade Commissioner,
when he heard the frank admissions of negligence at the
inquiry, "wondering whether or not he was in a lunatic
asylum." There were, of course, no technical questions in-
volved in the explosion, for whatever type of boiler had been
used the explosion would inevitably have occurred. The in-
quiry resolved itself into one of fixing responsibility for the
disaster, and in view of the engineers admissions as to the
personal part he played there could be no doubt where it
lay. The only excuse he could offer was that he thought the
stop valve was open, as it was left open when the boilers
were laid off on July 31, but he took no steps to verify this
assumption or even to look at the pressure gage before he
proceeded to hang on weights practically equivalent to a
man sitting on the end of the levers. Who shut the stop
Valve it was impossible to find out, and as regards responsi-
bility little matters, for the most ordinary precaution should
have suggested to the engineer that freedom for escape of
the steam generated in the boiler should be provided in some
way before such "an act of madness" as the overloading of
tile safety valves was resorted to.
The question remains, how can the consequences of similar
crass ignorance be guarded against in the future? The or-
dinary lever type of safety valve does, it must be admitted,
permit of being easily tampered with and overloaded. Of
course, whatever type of safety valve is used there is little
to protect it from interference, from reckless ignorance or
malignant ingenuity, though a locked-up valve which no one
could touch would protect such a fitting to some extent from
the former risk, and as the Commissioners, in their judg-
ment, which saddled the responsibility for the explosion en-
tirely on the engineer and the boiler attendant who assisted
him, emphasize the necessity of valves which can be pro-
tected from any interference being adopted, it is possible we
may before long see some Board of Trade regulation of this
kind imposed on all steam users. — "The Mechanical Engineer,"
Manchester, Eng.
B
ElainffiaEtica^noEJi of §sini©Mer SESHoIfee
With the idea of bringing about a better understanding
between the metallurgical industry and agriculture as to
the troublesome smoke problem at smelting and ore-roasting-
plants, the United States Bureau of Mines has just issued
"Bulletin S4 ."* Copies may be obtained by addressing the
Director, at Washington, D. C. Cnvners of smelting plants
are making every effort to devise ways and means to do
away with possible damage and annoyance from great volumes
of smelter smoke, comparatively rich in sulphur dioxide and
other injurious constituents.
It has been customary to discharge the smelter smoke by
very tall chimneys, on the assumption that if the noxious
gases are discharged at considerable height they will have
opportunity to diffuse more thoroughly and thus become so
diluted as to be comparatively harmleoS, but the efficiency
of this method is now being questioned. There is reason to
believe that the use of high stacks increases the area to
damage, whereas low stacks may intensify the damage but
concentrate it within a small area. Probably high chimneys
do not serve their purpose as well as was anticipated, and
the better method may be to dilute the smelter smoke and
discharge it from a number of low stacks.
Dascuassedl
A battle royal on the subject of electric rates was started
on Feb. 5 before the Committee on Public Lighting of the
Massachusetts Legislature, which is considering House Bill
No. 346, relative to the prices to be charged for electrical
energy by central stations. The bill was brought before
the committee on petition of the New England Power League,
an organization formed about three years ago by manufac-
turers, business houses, engineers of isolated plants and others
interested in the economical use of power. Ernest Stevens,
chief engineer of Riverbank Court Hotel, Cambridge, Mass .
led the advocates of the bill, which provides that no public-
service corporation shall be allowed to sell electricity at less
than 5 per cent, above the cost of production and distribution,
that the maximum price charged for electricity shall not
exceed 25 per cent, over and above the cost of production
and distribution, and that the Board of Gas and Electric
Light Commissioners shall have power to determine such
costs after a thorough examination of all books and properties
belonging to such companies.
The principal evidence on behalf of the bill was offered
by Thos. W. Byrne, consulting engineer, of Boston, who con-
tended that 90 per cent, of the users of electricity purchase
energy at the maximum price and that these small users
are charged at least five times as much per kilowatt-hour as
the large consumers of power, who easily buy electricity at
two cents or less per kilowatt-hour. The speaker urged that
the central-station policy is to "charge what the traffic will
bear," and said that the National Electric Light Association
at its Philadelphia convention in 1914 had gone on record
in support of the principle that the value of central-station
service was in a large measure determined by the ability of
the consumer to install a private plant.
Mr. Byrne contended that the basis of rates should be a
fair return on the investment and advocated a valuation of
all existing electric-lighting properties in the state by the
Gas and Electric Light Commission, for the purpose of check-
ing up the reasonableness of the rates now in force. He
pointed out that in the decision of the board in the Worcester
street-lighting rate case, the commission had called attention
to the power of the company to dictate prices to the small
consumer. Members of the Power League feel that present
•The suggestions contained in this bulletin may also be
applicable to the power-plant smoke problem. — EDITOR
February 23. L915
POWER
283
central-station rates in various cities of the state are dis-
criminatory, and favor requiring the commission to set forth
its views upon the price differences, if any, which should be
allowed between lighting and power rates, and between resi-
dential and other users, as related to the quantity of energy
purchased and as affected by long and short periods of use.
The owner bought the second-hand boiler about a year
ago, when he was told not to carry over 80-lb. pressure.
From the appearance of the boiler it ought not to have been
used and should have been in the scrap pile.
This is the third explosion of old boilers that has occurred
in this vicinity in the last three years, which goes to show
the great need of state boiler inspection and engineers'
license laws.
Usraafosd Stipes
According to recently compiled figures made by the U. S.
Geological Survey, the total available water power in the
United States amounts to about 200,000,000 hp., of which only
6,000,000 is developed. The total available is estimated on
the basis of practicable maximum storage of waters possible
by the construction of dams and reservoirs. Without storage,
the available water power is placed at only fil,678,000 hp., of
which the present development is about one-tenth. The water
powers as listed by the Geological Survey are distributed in
the several states and sections of the country as follows:
North Atlantic States
971,000
295,000
2lli;,(Mlil
273,000
16,000
164,000
2,037,000
127,000
821,000
South Central States:
Alabama
Louisiana
Arkansas
Oklahoma
236,000
New Hampshire..
913,000
Massachusetts . . .
Rhode Island
Connecticut
New York
75,000
2,000
73,000
250,000
Pennsylvania ...
South Atlantic State
Delaware 13,000
Maryland 146,000
Dist. of Columbia 13,000
Virginia 1,044,000
West Virginia.
North Carolina.
South Carolina.
Georgia
Florida
4,910,000 western States:
Montana 5.197,000
Idaho 3,OS0,000
Wyoming 1,566,000
Colorado 2,036,000
New Mexico 527,000
Arizona 2,038,000
Utah 1,581,000
Nevada 331,000
Washington 10,376,000
Oregon 7,935,000
1,261,000
1,050,000
812,000
752,000
16,000
5,107,000
California
9,3S2,000
North Central States:
Ohio
Indiana
Illinois
Michigan
Wisconsin
Minnesota
Iowa
Missouri
North Dakota. . . .
South Dakota. . . .
Nebraska
Kansas
213 000 Summary of States:
14L000 North Atlantic . .
South Atlantic . .
North Central
South Central
414,000
352,000
8 04,0(10
593,000
458,000
195,000
248,000
90,000
439,000
323,000
4,910,000
5,107,000
4,270,000
3,342,000
Western 44,049,000
Grand total 61,678,000
IFaftal Saiwumiiil
)<DnH@ir IEs£pIl©sfl©!a
On Jan. 20 at about 10 a.m. the boiler of a portable sawmill
near Beverly, Mo., exploded, killing two and seriously injuring
another. A father and his four sons were operating the saw-
mill on the lowlands of the Missouri River. The engine had
teen stopped to make some adjustment to the saw. Two of
Ihe boys had just left for home near-by, and the other two,
aged 7 and 18 years, respectively, were in front of the boiler.
The explosion killed the two boys instantly, disfiguring
them almost beyond recognition. The father was found in
the underbrush near-by, severely scalded and unconscious.
It is believed that he will recover. The boiler was blown
through a shed and across a boggy creek for a distance of
about 300 ft. from its foundation, striking the ground twice
before it finally stopped.
The boiler was of the locomotive type 11'- ft. long with
firebox 30x4S in. The front part of the crown and sides of
firebox were forced down nearly to the bottom of the furnace.
This was the only part that gave way. the tubes, shell and
outer firebox sheets remaining intact. The firesheets and
stay-bolt ends were badly pitted and eaten away by corrosion,
so that the stay-bolts had very little hold. At some parts
of the blowoff opening the plate was less than one-sixteenth
of an inch thick.
The safety valve and steam gage had not been found
up to the time of writing this, as the ground was covered
with several inches of snow that had fallen the following
night. The inside of the boiler seemed clean. The water
column and connections were clear so that it showed the
true water level. The injured man claims that there was
plenty of water in the boiler just before it exploded.
Digested by A. L.
UJecBSaoirtis
H. STREET
Assumption of Risk by Employee — An employee of a power
company who was directed to make repairs on a dam while
water and ice were running over it assumed the risk of being
swept from the dam by the force of the stream, according t'O
a late decision of the Maine Supreme Judicial Court, an-
nounced in the case of Monk vs. Bangor Power Co., 92 "At-
lantic Reporter," 617.
Negligent Operation of Hollers — When negligence of an
engineer leads another employee of a common employer to
believe that an explosion has occurred or is imminent, and
such other employee is injured in attempting to avoid the
danger apprehended, the employer may be held responsible
in damages, unless the "fellow-servant rule" happens to be
applicable. This statement is warranted by a late decision
of the Indiana Supreme Court, in the case of Stringer vs.
Vandalia R.R. Co. (106 "Northeastern Reporter," 865), wherein
defendant was held liable for injuries sustained by a brake-
man leaping from a locomotive after the engineer had per-
mitted the crown-sheet of the boiler to run dry and then
suddenly turned water on it, causing the crown-sheet to fall,
under circumstances which naturally tended to make the
brakeman suppose that an explosion had either occurred or
was imminent.
Edward P. Burch, E. E., has opened an office as consulting
engineer, in the Dime Bank Building at Detroit. General prac-
tice is contemplated, with specialization in mechanical and
railway work and in property valuations.
Dr. Robert Grimshaw, one of the early editors of "Power"
and the only living charter member of James Watt Associa-
tion No. 7, N. A. S. E., of New York, attended the Feb. 13
meeting of that association. Dr. Grimshaw is on a brie!
visit to the United States, having lived for many years in
Germany.
Guy E. Marion, secretary-treasurer of the Special Libraries
Association, has severed his connection with Arthur D. Little,
Inc., the well known chemists, engineers and managers, of
Boston, where he has been located for the last five years in
charge of their information department. He has offices in
the Tremont Building, Boston, with W. H. Manning, landscape
designer.
William W. Cole, of 43 Exchange Place, and Arthur S.
Ives and Rolland A. Davidson, composing the firm of Ives
& Davidson, of S4 William St., announce the formation of a
partnership for the general practice of engineering, under
the firm name of Cole, Ives & Davidson, with offices at 61
Broadway, New York. Especial attention will be given to
investigations and reports for financial interests, inventories
and valuations of public utility or industrial properties and
design, installation or management of power plants of all
descriptions.
Walter N! Cargill has been appointed superintendent of
power and lines of the Rhode Island Co., with head-
quarters at Providence, and will take up his new work on
Apr. 1. For eight years he was in charge of engineering,
construction and operation in the one substation and 10
power stations of the lines north of Boston now comprising
the northern portion of the Bay State Street Ry. He re-
signed in 1911 to join the enginering staff of the Stone &
Webster Engineering Corporation, where he has since been
occupied with investigations, appraisals and problems of a
mechanical character in connection with the generating
plants designed, examined or operated by the organization.
Lyndon F. Wilson, vice-president of the Railway List Co.,
Chicago, has resigned to become vice-president of the Bird-
Archer Co., New York, manufacturers of boiler compounds.
584
r 0 W E B
Vol. 41, No. 8
effective Apr. 1, 1913. He was born at Rush Lake, Wis., Nov.
4, 1SS3. He was educated at Ripon College, Lawrence Uni-
versity and the University of Wisconsin, and after some
general machine-shop and power-plant experience, became
an engineer in the service of the United States Government
(Department of the Interior), passing examinations in steam,
electricity, and heating and ventilating. After one year in
this service, he joined the engineering department of the
Western Electric Co. and was so engaged until the fall of
190S, when he became mechanical department editor of the
•Railway Review," Chicago. In the spring of 1909 he became
editor of the "Railway Master Mechanic" and was subse-
quently given editorial charge of "Railway Engineering," both
being published by the Railway List Co. He was promoted to
the vice-presidency of this company in the summer of 1913
After Apr. 1, Mr. Wilson will be located in the Chicago office
of the Bird-Archer Co.
COAL SAMPLING AND ANALYSIS — Technical Paper \
the Bureau of Mines, Department of the Interior, is a collec-
tion of notes on the sampling and analysis of coal, by A. C.
Fieldner. Copies may be had free by applying to the Di-
rector of the Bureau of Mines, Washington, D. C.
GEORGE WESTINGHOUSE — To those who did not know
him personally, a reading of the Tribute, by Arthur Warren,
will give an idea of the elements of his greatness and suc-
cess, and of the fullness of the life which he lived. Mr.
Warren's association with the master was intimate and of
long duration, and his Tribute is an evident labor of love.
PENNSYLVANIA RAILROAD has issued a booklet, for
distribution at the Panama-Pacific Exposition, describing its
activities and exhibit at the Fair and containing a map of
the entire system, which, it is claimed, serves 52 per cent, of
the population of the United States. It also contains illus-
trations of the proposed L'nion Station in Chicago, the main
span of the East River bridge, and a model of New York City.
A photograph of the last is also reproduced in colors on the
cover page. This model shows the city just as if one were
looking at it from an aeroplane. It reproduces faithfully
not only the main physical features of Manhattan Island and
the surrounding country and water courses, but the prominent
buildings, the streets, the bridges spanning East River, the
parks, and the squares.
CENTRIFUGAL PUMPS — What is probably the most com-
plete commercial publication devoted solely to centrifugal
pumps is being distributed by the De Laval Steam Turbine Co..
of Trenton, N. J. This book of 29S pages contains over 300
illustrations, including centrifugal pumps for all capacities
and heads and for motor and steam-turbine drives, diagrams
showing the "characteristics" of such pumps and explaining
the relations between impeller-blade angles and character-
istics, interior views and views of parts showing the con-
struction, views showing the method of manufacture by the
use of limit gages and methods of testing, installations of
pumps for various services, also numerous illustrations of the
DeLaval reducing gear employed to allow electric motors,
water turbines, steam engines and steam turbines to operate
at the most economical speed when driving a centrifugal
pump. The text matter is divided into chapters under such
headings as. "The Introduction of the Centrifugal Pump and
the Work for Which It is Adapted"; "Features to be Con-
sidered in Selecting Centrifugal Pumping Equipment"; "The
Use of the Characteristic Curve"; "Methods of Testing Cen-
trifugal Pumps"; "System of Manufacture for the Production
of Interchangeable Parts". "Details of Design and Construc-
tion of Single-stage and Multi-stage Pumps"; "The Speed
Question, Particularly Relating to Steam Turbine-Driven
Centrifugal Pumps"-; "Helical Speed-Reducing Gears"; "Mo-
tor and Belt Drives"; "High-Duty Steam Turbine-Driven
Pumps as Compared with Reciprocating Pumping Engines
for Water-Works Service" : "The Adaptation of Pumps for
Circulating Condenser Water. Feeding Boilers and other
Steam Power-Plant Service"; "Drainage and Irrigation
Pumps"; "Hydraulic Pressure and Elevator Pumps"; "Pumps
for Marine Uses. Mining Service. Fire Service and Hot Water
and Brine Circulation", etc. Tables and charts are given for
determining the resistance of pipes and the relation between
heads and spouting velocities. The investigation of the
lumping problem, together with drawing up of specifications
for centrifugal pumps, are also treated at some length. The
< lapters on 'Tump Characteristics" will prove more valuable
to the pump user than many of the more technical treatises.
The chapter on "Water Works Pumps," showing that under
many conditions the centrifugal pump can handle water at a
cost 20 to 40 per cent, lower than it can be handled by re-
ciprocating pumps, because of the lower fixed charges, it is
thought will be a revelation to many who have not recently
given this matter consideration.
VALVE GEARS. Bv Charles H. Fessenden. McGraw-Hill
Book Co., New York. Cloth; 170 pages; 6x9% in.; 171
illustrations. Price $2.
THE "MECHANICAL WORLD" POCKET DIARY AND YEAR
BOOK for 1915. The Norman Remington Co., Baltimore.
Md. Cloth; 439 pages, 4x6% in.; illustrated; tables. Price
50 cents.
THE "MECHANICAL WORLD" ELECTRICAL POCKET BOOK
for 1915. The Norman Remington Co., Baltimore, Md.
Cloth; 303 pages, 4x6% in.; illustrated; tables. Price
50 cents.
THE DESIGN OF STEAM BOILERS AND PRESSURE VES-
SELS. Bv George B. Haven and George W. Swett. John
Wiley & Sons, New York. Cloth: 416 pages, 6x9% in.;
197 illustrations, including several plates; tables. Price
TIRADE CATALOGS
D. G. C. Trap & Valve Co., Inc.. Fuller Building. New York.
Folder. Brown steam trap. Illustrated.
De Laval Steam Turbine Co.. Trenton. N. J. Catalog B.
Centrifugal pumps. Illustrated. 298 pp., 6x9 in.
Pelton Water Wheel Co.. 90 West St., New York. Bulletin
No. S. Water wheels. Illustrated, 64 pp., 6x9 in.
The Terry Steam Turbine Co., Hartford, Conn. Bulletin
No. 19. Centrifugal pumps. Illustrated, 64 pp., 6x9 in.
L. J. Wing Mfg. Co., 352-262 West 13th St., New York.
Bulletin No. 27. Turbine Blowers, Type E. Illustrated, 20
pp., 6x9 in.
Gas Engine & Power Co. and Chas. L. Seabury & Co., Mor-
ris Heights. N. Y. Catalog. Seabury water tube boiler. Il-
lustrated, 46 pp., 6x9 in.
Schutte & Koerting Co., 12th and Thompson Sts., Phila-
delphia, Penn. Sectional Catalog. Heat transmission ap-
paratus. Illustrated, S'»xll in.
Positions Wanted. 3
Positions Open.
Bureaus). Bi
harge 50c. an insertion, in advance
ivii Service Examinations). Employment Agencies (Labo~
Op portunities. Wanted (Agents and Salesmen — Contract
Work). Miscellaneous Educational — Books). For Sale, 5 cents a word, mini
mum coarse, S1.00 an insertion.
Count three words for keyed address care of New York: four for Chicago-.]
Abbreviated words or symbols count as full words.
Copy should reach us not later than in A.M. Tuesday for ensuing week's issue
Answers addressed to our care. Tenth Ave. at Thirty-sixth Street. New York of j
1144 Monadnock Block. Chicago will he forwarded (excepting circulars or j
similar literature!. j
No information given by us regarding keyed advertiser's name or address. j
Original letters of recommendation or other papers of value should not be In- j
closed to unknown correspondents. Send copies.
Ad vertisements calling for bids. S3. 60 an inch per insertion. P j
pumi
POSHTHOHS OFEM
\N EXPERIENCED CENTRAL-STATION ENGINEER re-
quired to take charge of a 4000-kw. steam and electric plant,
containing turbine- and engine-driven AC. and D.C. genera-
tors, water-tube boilers and stokers; must be particularly
well versed in steam economy: plant located 50 miles from
Chicago; salary $1."00 per year: only a thoroughly competent
and well recommended man need apply. P. 430, Power, Chi-
cago.
Competitive examinations for the ciril-scrnee positions named below will >•■ '
or up to the dates girt n. For detailed information, write the addri Ml a speafiei.
ELECTRICAL ENGINEER (male); $200-$300 per month:
for vacancy in the Accounting and Engineering Dept. of the
Illinois Public Utilities Commission. Write to the State Civil
Commission, Springfield. 111.
DRAFTSMAN (male): $75-$100 per month: examination
Mar 6; for vacancy in the Accounting and Engineering Dept.
of the Illinois Public Utilities Commission. Write to the
State Civil Service Commission. Springfield, 111.
GAS ENGINEER (male: ?250-$333.33 per month; for va-
cancy in the Accounting and Engineering Dept. of the Illinois
Public Utilities Commission. Write to the State Civil Service
Commission. Springfield. Til.
r
*/
Vol. 41
POWER
NEW YORK. MARCH 2, \'.)\:>
No. 9
TMIE 1LOHGEM. WAY IS SAFI
28G
P 0 W E Pi
Vol. 41, No. 9
Mini!
©mi
By Thomas Wilson
SYNOPSIS— An attractive plant equipped with
angle-compound- centrifugal pumping units. Its
rapacity is I -Y) .000 .000 gal. in I /ccnty-four hours.
The efficiency of the pumps is 70 per rent. The
equipment cost $1 18,000.
One of Detroit's show plants, put in commission in
October, 1912, is the Fairview sewage-pumping station.
The machinery is neatly arranged and kept in excellent
condition. The boilers wear a "dress suit" of white
enamel brick, which with metal trimmings at the corners
and across the front add to the general attractiveness
of the boiler room.
The building itself is of the classic style of architec-
ture to harmonize with the surroundings, as eventually
the plant will be in a residence district. Buff Eoman
brick walls trimmed with terra cotta are reinforced by
a steel frame. Concrete slabs covered by red tile form
the roof. Within, a wainscoting of white glazed tile,
walls of gray face-brick, a floor paved with red tile,
steel doors, electroplated railings and Fenestra steel sash
lend an attractive appearance.
The plant is located at the loot id' Parkview Ave.,
near Waterworks Park, and 234 ft. hack from the harbor
line. It was designed to raise domestic sewage ami storm
water from a 9-ft. sewer draining 3500 acres of residence
property and discharge it into the Detroit Eivcr. The
vision wall in I he basement. This well is 1:31 It. long,
10 It. deep and !) ft. wide. As shown in Fig. 1. the
sewage flows by gravity into the suction of the pumps
Fig. 3. Boilers in Their Dkess Suits of White Tile
7/
DRI V E WAY
TYPICAL CROSS-SECTION
Fig. I. Plan and Vertical Section through Station
sewage enters a screen chamber, shown to the left of the
main building in Fig. 2, and passes on to a water gal-
lery formed between the building foundation and a di-
Pig.
Fairview Sewage-Pumping Station
and through cast-iron pipes is raised 36 ft. to brick out-
lets discharging into the river. IIvdraulically operated
gate valves are placed in the discharge lines.
The pumping equipment consists of two steam-driven
units, each having a capacity of 100 eu.l't. per sec, and
a motor-driven pump capable of delivering 30 cu.ft. per
sec. Provision has been made in the design of the
plant for the future installation of a third steam unit.
The pumps are id' centrifugal type set horizontally with
vertical shafts and hall' imbedded in the concrete of the
basement floor. Two are 42-in. units and the third is
a 24-in. pump, the suction connections to the water gal-
lery bein- .") I ami 36 in. diameter, respectively. The
large pumps arc driven by variable-speed angle-compound
engines. IS and -U\ by 36 in., which, at 1 ">0 lb. gage pres-
sure, is lb. receiver pressure, a vacuum <>( 25 in. and a
speed of loo r.p.ni.. indicate 500 hp. The steam supply
March 2, L915
P 0 W E It
287
pipe is 6 in. diameter, the high-pressure exhaust LO in.
and the low-pressure exhaust 12 in. All piping except
the loop to the throttle is underneath the floor. Con-
nection between engine and pump is effected by a i*1/^"
in. vertical shaft 40 ft. long. Near the center of its
length a bronze and cast-iron thrust bearing carries the
weight of the shaft. The bearing runs in oil and is pro-
vided with a water jacket which may be used if needed
oil long continuous runs. Ordinarily, the oil keeps the
hearing cool.
water-tube boilers are installed, with -pace for a third
unit. Top-feed stokers with a projected grate area of t8
sq.ft. serve the boilers. City water is used as boiler feed,
as the river water supplied to the condenser is muddj
and unsuited for the purpose. Either a duplex pump
or an injector handles the supply, which is raised to a tem-
perature of 200 deg. in an open heater, taking exhaust
steam from the feed and condenser pumps.
Meadowbrook run-of-mine coal is burned. It is stored
in a 200-ton hunker in front of the boilers and delivered
\o. Equipment Kind
2 Engines Angle, compound
PBINCIPAX EQUIPMENTS FAIRVIHW SEWAGE PUMPING STATION
size Use Operating Conditions
Maker
on i 36 by
35-in Drive cent, pumps.... Steam press. 150 lb., vaouum 25 in., 100 r.p.m. Wisconsin Engine Go.
2 Pumps Centrifugal. 12-in Main units.. . Capacity 100 sec.-ft. against 36 ft. head Camden Iron Works
1 Pump Centrifugal. 24-in.. . Main unit Driven by 150 hp. Westinghouse motor, 360
r.p.m Camden tron Works
1 Condenser Barometric lt'.-in Servingengir.es River injection water, vacuum, 25-in Camden Iron Works
1 Pump.. Centrifugal. . ti-in. discharge Water to condenser ... . Driven at 350 r.p.m. by 8xl0-in. Shepherd
double engine Camden Iron Works
1 Pump Centrifugal 2-in. discharge .Sump pump Driven by ."clip. Westinghouse motor, 1120
r.p.m Camden Iron Works
1 Crane. Traveling, hand op-
erated 14 tons Serves main pump room Northern Engineering Co
2 Boiler- Vertical water-tub 300 hp Generate .team 150 lb, pi - . sal steam, stokers Babcock & Wilcox Co.
. Top feed Projected area
18 sq.ft.. Serving boiler?. Detroit Stoker Co.
1 Pump.. Duplex. Sx5xlO-in. Boiler feed pun Canton-Hughes Pump Co.
1 Injector 2}-ii) Boiler tied Penberthy Injector Co.
1 Heater Open .. 600 hp. Host feed water Use exhaust steam from pumps Warren Webster & Co.
A barometric condenser maintains a vacuum of 25 in.
hi the engines. Cooling water is obtained from the river
and is forced to the condenser head by a centrifugal pump
driven by a double 8xl0-in. vertical engine at a speed of
550 r.p.m.
The 24-in. pump is directly coi cted to a 150-hp.,
550-volt, three-phase motor, having a speed of 360 r.p.m.
Current at 6500 volts, supplied from the public lighting
plant, is stepped down to the proper voltages for the
motors and lamps in the station. The ordinary dry-
weather flow is handled by this unit, which, due to the
Fig. 4. Angle-Compound Pumping Engines
large capacity of the wati c chamber, may lie shut down
during peak loads at the source of electric supply. The
plant i- operated on three shifts per day and ordinarily
an hour and a half of pumping on each shift will dispose
of the sewage. It is necessary, however, to keep the boil-
ers banked and the steam units ready for service, as a
heavy storm would soon supply enough surface water to
tax the capacity of the station.
In the steam-generating part of the plant, two 300-hp.
by hand to the stokers. Over the top of the hunker a y±-
'ton electric hoist is suspended from an 8-in. I-beam. The
track extends out of the south end of the building where
coal is delivered by wagon. Eventually a dock will be
built and coal will be delivered by water.
Due to the intermittent operation, satisfactory operat-
ing data are not available. In the guarantee the pumps
were to have an efficiency of 70 per cent, and the engines
to develop an indicated horsepower-hour on 14 lb. of
saturated steam. The three units have a total capacity
of 150,000,000 gal. in 24 hr. The building cost $144,00o".
the site $20,000 and the equipment $118,000. Per mil-
lion gallons of daily capacity, the total equipment of the
station cost $786.66. Smith, llinchinan & (Irvlls, of
Detroit, were the architects and engineers for the station
and Charles Meny is chief engineer of the plant.
The Rate of Rndiation from bare steam pipes is approxi-
mately 3 B.t.u. per lir. for each square foot of surface ex-
posed to a temperature difference of one degree between the
steam inside the pipe and the air surrounding it. Therefore,
the square feet of surface multiplied by the temperature dif-
ference (inside and outside of the pipe) multiplied by the
constant 3 gives the total loss in B.t.u. per hour from a given
pipe.
Interesting Accounts are to hand from Sweden regarding
the results of trials lately conducted by a leading Swedish
company on two sister steamers, one, the "Mjolner," being
fitted with turbo-electrical engines and the other, the "Mimer,"
with ordinary triple-expansion engines. Each is of 2225 tons
displacement and designed for a speed of 11 knots, a stipula-
tion being that in each case the engines were to develop '.inn
i. hp. The most important factor, however, was with regard
to the consumption of coal, which was guaranteed to be 30
per cent, less in the turbo-electrical vessel than in that fitted
with the triple-expansion engines. For the trial trip, which
lasted seven hours, the screws of the "Mimer" were fitted to
the "Mjolner," so as to avoid possible difference arising from
any difference in construction. During the trip the turbo-
electrical engine developed 975 i. hp., or 75 more than the
guaranteed maximum, while the average speed was 11. S knots.
as against 11 guaranteed. Good as these results are, the
small consumption of coal exceeded the most sanguine ex-
pectations, amounting to 0.4 kg. per indicated horsepower,
which works out at 35 per cent, less than the consumption
on the sister ship, the "Mimer." Both steamers are to be
employed in the coast trade and their hulls have been espe-
cially constructed for navigation on the ice. — "The Ensrineer."
.
1* U \\ r E R
Vol. ll, No; y
^mteresftiimg Steam-Pip© lini§>4al!sv{ti©f!i
By Hubert E. Collins
SYNOPSIS — Two old boiler plants arc piped to
give a common steam supply and to equalize the
load on each. Details of the pipeline construction
are giv< n.
The United Piece Dye Works, Lodi, N. J., were con-
fronted with the problem of maintaining operation with
an insufficient boiler capacity in one of the mills during
the past winter and space did not permit of putting in
The -in. header from the power plant runs into the
one ovei the front of the boilers in the mill plant
and tl headers there are connected with a 10-in.
header. As this combined boiler plant carries 120 lb.
pressure and the boilers at mill A 75 lb., a reducing valve
is situate at the mill B end of the pipe line.
Eqtj ■ t: '\<; Steam Lines
The lines connecting these two boiler plants are called
equalizing steam lines, as the purpose is to equalize the
capa ity to conform to the needs of either plant.
The arrangement of the two steam headers in the boiler
rooms of mill B allows steam to be faken from either of
them, from the power boiler plant oi >om all three.
These three supply sources lead to the 10-in. header.
Fig. 1. From a line about twelve fee* from the front
Fig
1. Location op Valves., Trap, Expansion
Joints and Anchorages
more boilers. A larger plant, however, had some capacity
to spare which would be of assistance to the other ii:' prop-
erly connected. The two boiler plants were not far from
1500 ft. apart, and it was decided to connect the headers
of the two boiler rooms with two <i-in. steam lines. The
combined capacity of these two boiler rooms is around
3000 hp. Mill .1 has about 2000 boiler-horsepower capa-
city.
The boilers in mill B are connected to two headers,
Y ■"- POWE.R
header, the 10-in. line branches to the outside wall of the
building next to the river. This line has a 10-in. stop
valve A, which is bypassed through an 8-in. reducing and
regulating valve C, with stop valves B and D on each side
of it. At the point where the 10-in. line comes outside
the wall over the smoke breeching, two G-in. lines are
m
Expansion G
| Anchor 1 1
(TrdDU Anchor 0«B
| 1 Anchor L / I^U\
\ \ I \ Expansion M / j
lYHH Hn .'uj ill
\ m
r- m
if in— nil ■ £VHl
m
W~ ..
■ -.*-"
^^tart
EH^^U^^^T1'^ r'l^^5
L
/ V - ^^-^POWER
Fit
Steam Mains from Mill Boiler Plant
one over the front and the other over the rear of the
settings. The power plant in mill />' is connected to a
single header, which is connected to the mill boiler head-
ers with a 6-in. bleeder. These three headers are the
sources of steam supply, connected as shown in Fig. 1.
taken through two 6-in. valves. These two lines run
parallel to the mill .1 boiler plant. From the 10-in.
header they run at right angles horizontally to the wall
of the power boiler plant, turn at a right angle and pass
over the smoke flue on to the corner, then another right-
March 2. 1915
pow e i;
389
angle turn and along to a poini midway of the engine-
room wall, where they drop t<> the level of the river bank.
The lines are supported on brackets made East to the wall
of the building, and are pitched in the direction of fkffi
with a fall of 1 in. in 15 ft.
1 w
Eft ~~.
i-^t
""-arte
^BL *ril l ?H
Expansion P ^A
AA
Fig. 3. Two Steam Lines Running under a Bridge
The pipes are anchored at the first corner of the power
boiler-plant building and near the pier support outside
the engine room, where they take the first drop. Midway
between these anchorages // and / is placed the first slip
expansion joint G.
After the first drop the lines run horizontally along the
river bank on wood supports. At the bottom of the first
fall is placed a tee on each line that acts as a drop-leg,
from which the drippage is removed. The lines are
pitched down along the river bank in the direction of flow,
8 iii. to 15 ft., to a point beyond the railroad trestle ( Fig.
2), also at the turn between the anchors ./ and K ( Pig.
1 ). At the first support from the power boiler plant and
the engine house is the anchor L. The distance from
these third anchors to the fourth set on the river hank
is 256 ft. A set of expansion joints M is placed in
front of the fourth anchorage. From fourth to the fifth
anchorage is '.':;; ft. and the expansions N are placed just
in front of the anchorage J.
Fig. 2 gives a view of the steam lines as they come
from mill B boiler plant arou id and along the wall of
the power boiler plant to the point where they drop to the
ground surface and along the river bank to the expansion
A. at which point they turn to run under the bridge
to reach the yard of mill A. At the extreme left of Fig.
2 can be seen the .smoke fine, over which these steam lines
pass. The pipes are supported on the walls above the
ground by brackets. At the extreme right is the housing
for the expansion joints A.
Ten feet beyond this the lines drop 2 f in., then turn to
go under a bridge. At the first support after turning
from the railroad track is the anchorage ./. Just beyond
is the expansion set /'. The lines run under the bridge
with a fall nf about 1 in. in 15 ft. and next to tin- retain-
ing wall of the mill A side the drop is '- I in. At this
point the lines turn at another angle and pass through
this wall underground to the receiver room, where just
inside the wall iii the pipe tunnel are placed the valves Q
and R on the horizontal runs. From these, the lines
are joined in a V and empty into a receiver, which catches
all drippage from the valves 8 and T. It also takes care
of the drippage from the vertical lines over the receiver,
and which is dropped by the trap U, placed in the re-
ceiver pit. From the receiver the lines are taken from a
Y on the top. Two (i-in. valves F and II' are placed on
the top of this V and from these valves the lines extend
through the roof of the receiver house ami are carried
over the roof of the adjacent buildings.
Fig. :! shows the two steam lines near the point where
'he\ turn toward the bridge, looking toward the trolley
bridge and mill .4 yard from the mill 11. The first
pipe is for water; the two steam lines are just hack of it.
Fig. I shows the steam pipes passing from under the
bridge through the concrete abutment in front of the
receiver house. The steam lines in this view are the ones
on a line with the lower side of the bridge girders. The
-team pipes are also shown as they leave the receiver house
to tlie level of the roof of the adjacent building and rest
on the roof supports.
At the second roof support is placed the anchor A
( Fig. 1). The pipes have a fall of 1 in. in 15 ft. over
the roofs of the buildings and are pitched down from the
point over the receiver house. Fig. 5 shows the lines on
the roofs from the point over the receiver house almost to
Fig. 4. View from the Otheb Stuk ok the P>ridge
the first turn, shown in Pig. 6 at the extreme left. On
the second support beyond this turn (not shown ) is placed
anchor Y. Fig. 1, and in front of it is the expansion Z.
On the edge of the roof at the alleyway the lines break
at right angles horizontally and run over the alleyway
roof. One line feeds the li n ishi tig-room side of mill A,
going through the roof of the alleyway to the finishing-
room steam main, which runs horizontally and at right
angles to the equalizing lines just under the roof. Just
in front of this break in the line is a drop-leg, to which
is attached a trap, and next to this drop-leg is the valve
290
P 0 \V E B
Vol. 41, No. 9
B'. The 6-in. drop-leg ends in a blank flange, from
which the drip line is taken to the trap in the basement
almost underneath the drop-leg. The other equalizing
Line supplies the dye house and runs across the roadway
in front of the alley, turns at right angles horizontally
for a few inches and then drops to the S-in. dye-house
main. At the second support over the alley i> placed
the anchor (" on the dye-house main only. Expansion
in the finishing-room main is taken care of by the drop
Start from P6.
From receiver
Fig. 5. Pipe Lines ox Roof
of Fig. 1 and the other illustrations will show as feu
turns and bends as circumstances would allow. The ex-
posure to the weather required care as to the drainage
and the amount of pitch given seems to have been ade-
quate.
The supports were required to carry an average of 530
Hi. each when spaced 1 -j ft. apart. Figs. ; and 8 show
the type of the ground and roof supports, respectively.
The ground supports have a plank 10 in. by •") It. on the
bottom to take tin- weight. They are bedded on stone or
brick. The two side braces are buried in the earth and
thus take up any lateral thrust in the direction of the
pipe lines.
The roof supports are braced to take this thrust. In
order to distribute the weight on the roof as much as
possible, a continuous line of plank was placed under the
legs of the supports.
Fig. 9 represents the type of support used on the side
walls of the buildings that the lines skirted. A channel
was placed at the back of the wall to distribute the load.
Fig. 10 shows how the anchorage of the pipe is made
at the different points. It consists of a distance piece
made of %x3-in. iron, to hold the pipejii line above
the wood support, and a strap of the same size of iron
to hold the pipe down.
Fig. 1 1 shows the method of anchoring along the rivet-
bank. In addition to the clamp on the support, there is
a clamp mi the pipe with a rod leading from it to a plank
buried some feet in front of the support.
The pipes were covered with 85 per cent, magnesia
molded nonconducting material, wired on and covered
with magnesia cement on the flanges and fittings. Over
the covering was placed rubberoid paper wired on and
over this was sewed tarred canvas.
Settling of the supports on the river bank was looked
Turn
TO finishing room
To dye hou6e
Fie i). Neab View of Pipe Lines
through the roof of the alleyway. The expansion in the
dye-house main beyond the anchor C is taken care of at
the drop to the 8-in. main, which forms a swing joint.
Det uls of Construction
The details of construction of the line and its accessor-
ies are of interest, because some of the conditions met
were outside the average experience.
The installation of these lines offered many difficulties,
as much of them were exposed to the weather. A study
Pom' lnd Method of Supporting Them
lor and taken care of by placing the loose lengths of pipe
on the supports for about ten days before the roller
bases were lined up. There was considerable rain during
that time and therefore there was but little settling after
the line was in position.
Some Performances
When the steam lines were put under steam pressure,
there were less than ten leaks on all this piping ami U
three defective flanges.
March 2, 1915
I'd w e i;
291
While the pipes were -till bare and the temperature of
atmosphere was 30 deg. 1'.. the lines were heated and
put in commission within 25 ruin, without water-hamm ir
pom condensation.
After tin' lines were covered and in commission, the
losses by condensation were cheeked. The two dumping
traps on the line were observed to lake, on an average,
. for an operation. As the amount of water dis-
charged by each operation was known, a close estimate
of the amount of condensation was secured. The trap
al the receiver discharges at each operation G5 lb. of water
445
2.3 per cent, loss ly condensation
The charl I Fig. 12 | gives some idea of the performance
of the two lines. The heavy line gives the steam pressure
at the source of supply at the pressure-regulating valve
in mill B. The 'lotted lines give the pressures on each
of the two lines at a distance (lose to 1300 ft. from the
source of supply. One point gained by these equalizing
lines was that there was a more uniform pressure in mill
.1. as shown by this chart, whereas prior to this the daily
si §a
h! dround
AVOODEX CtBOI'XD
Support
Pig. 8.
Pipe Support on
Roof
Fig. 9. Wall
Support
Fig. 10.
Anchob uje
Pit
1 1. Method of
Anchorage
steam variation amounted to as high as 45 lb. pressure.
The drop in pressure in the 1300 ft. of pipe can also he
observed, At the point of maximum drop, the amount is
15 lb., while the two 6-in. pipes are supplying steam at the
rate of 30,000 lb. per hr.
When the lines were first installed a trap was placed on
the drop-legs at the first drop out. de the wall of the en-
gine room. Tt was later observed .hat after the lines were
warmed up there was not enoi^ii condensation collected
at that point to operate the trao more than once or twice
"6 769K>IIIZI23456789IOII2l2345678910lll2l2345&789IOII!2l234567a9IOII12l2i4S6789IOIII2l23456789IOIiei2345&
A.M. — P M. ?4< AM. ►]< P.M >4<— -A.M:— >4< PM — »]< A.M. >4< P.M.
— >KJ TUESDAY DEC. 9th-- >J<- WEDNESDAY DEC. 10'" -— j+fr THURSDAY DEC 1 f
POWER
Fig. L2. Charts of Steam Pressure os Steam Lines
MONDAY DEC. 6, tOI-l
and number A' 20 lb. During a given period in Decem-
ber the trap- were watched and it was observed that tin-
trap V was operated five times per hour during the 24,
and trap A' three times. The amount of steam flowing
through the pipes was recorded by -team-How meter-.
The average amount of steam per hour for the six days
of the observation was 18,990 lb.
Amount of condi nsation equaled :
65 X 5 X 24 = 7800
•.''I 3 24 = 1 ! id for finishing-room side.
144') for dye-house side
Total for 2-1 In-.. 10,G80 lb.
10,680
= 445 11, . per lir.
per day. The trap at this point was therefore discon-
nected and only the drip valve left to use when first
warming up.
SS
The Effect of Vanadium in plain carbon-steel castings is
to increase the elastic limit ibout 30 per cent., giving a much
higher proportion of available strength for the same ulti-
mate strength.
8!
.An Effective ''reatment by which the porosity of cement
user] in constru ..snal work can be stopped and the free lime
neutralized is said to be the painting of the surface with a
solution of S% ,'d o, zinc sulphate in a gallon of water. A
■■•action between the zinc sulphate and the free lime occurs
as deeply as the .Nation penetrates, and by it the insoluble
neutral salts, calcium sulphate and zinc hydroxide are pre-
cipitatec.' into th^ pores. This priming coat should be given
some 90 ir to dry, the surface then being brushed and painted
with two coa's of a good cement paint.
. :
IM) W ER
41. N(
>eeping TirgusR of Plsumtt Operaftioim
F»y A. D. Williams
SYNOPSIS — Recording instrumi istem
'ant records employed at the Cleveland Munic-
ipal plant.
Economic conditions make it necessary to keep an
accurate check upon each process of power-plant oper-
ation. The new municipal plant in Cleveland is pro-
vided with facilities for determining the heat value of
coal and the analysis of coal, ashes and flue gases: instru-
ments and meters are installed which either indicate or
record changes in the operating conditions: and a few
simple forms provide a complete report of operation.
The bunkers at the plant have a storage capacity of :i tOO
tons, and the coal cars are spotted on two tracks above it.
the coal being dumped through steel-bar grating- which
are shown in Pig. 1. Telpher weighing larries having a
capacity of two tons each are used to transport the coal
from the bunker spouts to the stoker hoppers. Each tel-
pher operator turns in a report giving the weight of coal
delivered to each boiler and the time of delivery. These
weights are totalized for each watch and entered on the
daily plant report.
This daily plant report is arranged to give a complete
insight into station operation, there being twenty items
to be filled in for each watch. Sixteen of these are ob-
Fig. 1. Geating oveb Coal Bunkeb. Fig. 2. Office. Fig. 3. Turbixe Governor and Gages
Slack coal is delivered at the plant in dump cars run
on a switch over the eoal bunker, and four samples for
analysis are taken from each car. All the samples for
each shipment are mixed and crushed, and two laboratory
samples are taken — one for analysis in the laboratory, the
ether to be held as a cheek sample in case any question
arises. The chemist determines the moisture, ash and
sulphur content of the coal and its heat value, the last
determination being made by a Parr oxygen bomb calor-
imeter. The price paid for the coal is based upon a speci-
fied standard of 13.000 to 13,099 B.t.u. with Less than 15
per cent, ash and k>> than :! per cent, sulphur. Lower
'•.eat value and higher ash and sulphur are penalized,
while a premium is paid fur a higher heat value. A
blank form i- provided upon which all shipments of coal
received arc reported by tin- chemist, together with its
analysis.
tained from the readings of meters or recording instru-
ments, three are computed from other items and one is
obtained by reference to a steam table. The equipment
of meters and gages in this plant is interesting. Fig.
2 shows the engineer's office where eight different record-
ing instruments are installed. The readings of the C'l V.
recorder are checked every few days by an Orsat ap-
paratus. One electric meter is found in the engineer's
office : this is a graphic megowatt meter which totalizes the
entire electrical output of the three main generating units.
The feed water for the boilers is metered or weighed
by a V-notch meter having a capacity of 2T5.000 lb.
per hour, and its temperature is recorded before it ei
and after it leaves the economizers. The temperature of
the flue gases is also recorded at both ends of the econo-
mizers, and the temperature of the ingoing gases i- a
continual cheek upon the combustion results obtained
March '?. 1 ! 1 1 r,
I'll W K R
203
E
DAILY PLANT REPORT
. 53RD ST MUNICIPAL LIGHT PLANT. DATE
;-
W.cr lb. ,«]
CW lb. ,»ul
-'
„! ,„„un,i„,
t „|
,,.,, ,„„,„
,„„„,
..
H
I
„r |b „J
Pea] autpw of wfcTnw k-w hr.
A„„l,.r. |..,d |.,k
V.S„, I...J 1.- I« (ll.U<H, )
1 -Hi. 1 l-wbr- (IMOvoli.)
.
U. sio.w per k» Generated:
L_
. Output
1
DAILY RECORD
MACHINES IN USE V n,
E. 53»o ST MUN.C.PAL LICH, PL.~T O.T.^^WJLfef
—
—
■
—
-
>_
—
—
-
-
-
-
giJfrnHfur,
WifW •
COAL CONSUMED
BOILER No. 1
BOILER No 2
BOILLB No 1
BOILER No 4
Boua Nb i
BOll.EB N„ .
1W
Wo«ht
Tune
w, ,n
r™
Wt,,M
T.n» j Wright
1..UI
Wt.rk.
_J]_=^
■
DAILY REPORT OF CARS COAL RECEIVED
E. 53RD ST. STATION
-"
woo»r Luc
«u»»
™
"SIT
.«.,,..
- — r- — i -
=3
Poems for Operating Records
in the boiler furnace. A further check upon boiler op-
eration is obtained from the indicating flow meter showing
the strain output and by draft gages which show the draft
pressure in the combustion chamber and in the boiler
bias! main, while the .-team temperature and pressure in
the header actuate recorders installed in the engineer's of-
fiee. An indicating draft gage in the induced-draft Fan
mom shows the draft at this point in the line.
The test of the boilers and stokers developed an inter-
esting draft feature. In these boilers, a cross-section of
which was shown in Power of Jan. 19, the combustion
chamber is extremely high, resembling the well known
Delray
ta ined :
setting.
Top of He i pass
I'.iii torn >>l Iasl pass.
Upper damper. — 0 10
rhe f«
II
<w ing
Iraft r.
idings
Were ob-
1
o
3
4
b
156 s7
149 .">!
197 80
27:! S3
— (1 . 00
+0 19
o ,
— (1 10
ii 06
+0. 16
+11 06
+o a?
—0.05
1 II L>L'
+ 0 01
—0.03
—0.09
r-0 16
—0.07
—0.43
— 0 08
4-0 15
—41 15
PRINCIPAL EQUIPMENT OF METERS ANDG \CKS, EAST 53D ST STATION, CLEVELAND MUNICIPAL ELECTRIC LIGHT PI-ANT
>. Equipmenl Kind Use Location Makei
Barometer . Mercurial Atmospheric pressure .. . Turbine room. . ...
Pressure gage. Indicating Exhaust pressure Main unil
Pressure gage Indicating . . . Inlei pressure Main unil
Pressure gage. Indicating ... Steam pressure. Mam unil
Pressure gage Imlicatiim Bearing-oil pressure Main unit ....
Pre sure gage Iu<lie;,ting P. ! i\ -oil preSSUT*. .Mam unil
Vacuum gage Mercurial Condenser varan i m Main unil
Tachometer. ......... S]
Flow meter G. V, Indicating.. Ste
Draft gage.. Indicating Bo:
I )r.at gage. Inclined i ube Boi
Draft gage Indicating . Drj
'I In i r 1 1, 1 1 Recording Ga
Steam gage., Recording . He
Thermometer. Recording. <*>
Thermometer. Recording Fei
(Thermometer, Recording Fei
Thermometer Recording Ga
CO, recorder, Simmance-Abady... Coi
Feed-water metei Lea V-notch , Fe.
Integrating and recording.
Totalizing meter (elec- Graphic recording, :j cir-
Main unit Sehuchardt .V- Schutte
On boiler setting . . . General Electric Co
On boiler setting Precision Instrument Co.
Each boiler setting Schaeffer & Budenberg
Induced draft (an i n Precision Instrument Co.
South en. I Ml l.nih-r room .... The Prist. ,1 < \ ,
Engineer's office Schaeffer & Budenberg
Engini er's on" The Bristol ' to
Engineer's ..dice The Bristol Co.
Engineer's office The Bristol Co.
lonomizei Engineer's office . The Bristol Co
a record Engineer's office Precision Instrument Co.
supply.. Recorder in engineer's office Yarnell-Wari g Co
essure
i. in. mi/-., i
trie)
Each auxiliary turbint for pow
The ivitchboard equipi.>en1 c
* ami i
load in megowal
■iter service has a gage ami tachometer
Engineer's Office Westinghouse E. •k M. Co.
i he main units.
294
POW E R
Vol. 41, Xo. 9
These readings show positive pressure at the top of the
tirst pass, which is rather remarkable. At the same time
the ('(Jo in all the tests was over 15 per cent, and in only
two did the oxygen run over 3 per cent.
mag sv.
By J. F. Jones
Centrifugal pumps, unless submerged, must !«• primed
before they will operate. The experience of tin- writer
with priming while in charge of an irrigation plant in the
Uulf Coast regions of Texas may be interesting.
This plant lilts water from the San Jacinto River to a
300-ft. wooden Hume, which discharges into a canal sys-
tem watering several thousand acres el' rice. The four
centrifugal pumps used have rather long discharge pipes,
Fig. 1. The pump shown is a 30-in. single-suction,
'.'o.OOO-gal. per min. capacity pump ami is rope-driven by
a Greenwald compound condensing engine.
The discharge pipe i- 61! ft. long, the upper end being
closed by a flap-valve. For priming, a steam ejector was
connected to a 2-in. hole on top of the pump casing. The
ejector produced enough vacuum in the suction-pipe, pump
and discharge pipe to fill the suction pipe and pump with
water: then the engine would he started and brought
up to speed.
This is the usual method of starting recommended by
the pump builders. The length of the suction and dis-
charge pipes caused many small air leaks, which con-
dition was further aggravated by the difficulty of making
the flap-valve seat air-tight. One night when shutting
Fro. 1.
Relative Locations of Pump, Engine and
Flume
down there was a loud report and a stream of water came
pouring down from the end of the flume. It was found
that the upper end of the discharge pipe had collapsed
for a distance of several feet and that the heavy cast-iron
flange on its end was broken and torn loose from the
flume.
The cause of the accident was plain. When the flap-
valve on the end of the discharge pipe closed, the water
ran down through the pump, forming a vacuum in the
pipe, and the atmospheric pressure collapsed it. Just
why a pipe calculated to resist an internal pressure of
150 lb. should fail under an external pressure of less than
1") lb. may not he apparent at a glance, hut there was no
disputing the fact. It was clearly time to make a change
in the method of starting this pump.
First, the flap-valve was removed and a swinging gate
was put in the flume several feet from the cud of the
arge pipe which, being open to the air. could not be
subject to a vacuum. Second, the ejector was taken off
the top of the pump casing and connected to a 114-in.
pipe-threaded hole drilled in the highest part of the suc-
tion elbow. Fig. 2. With this arrangement, the pump
i:- started as follow - :
First, it i- necessary to have the lower end of the
Ejector
Fro. ■?.
Eow the Present Priming Ejector 1c
i 'n\ \ 1 1 1 1 H
discharge pipe contain enough water to seal the discharge
outlet of the pump easing. The leakage from the gati
in the flume was usually ample for tin- purpose. Except
when the water in the flume was low. it would be necessary
to open the gate by hand to allow enough water to flow
back into the discharge pipe.
Second, the throttle would be opened and the engine
brought up to speed, as shown by the cutoff hooks begin-
ning to trip by the action of the governor. When the
ejector was started, and as the sealing water would be
held in place by the revolving impeller, a vacuum was
created in the suction pipe and in the pump sufficient
to cause them to fill with water. When the pump "cot
the load." as shown by a slight decrease of speed, the
throttle was opened.
As the ejector no longer had to exhaust the air from
the 67 ft. of discharge pipe, the time required to start the
pump was shortened, usually taking only four or live
minutes for priming. A vacuum gage on the suction side
of the ejector was found desirable.
Simplified Formulas — Two rules or formulas for finding
tin capacity of tanks in t'. S. gallons and for finding- the heat-
ing surfaces of boiler tubes are given below, which are easily
worked out by simple multiplication, no division being i
sarv:
Rule — To find the capacity of a cylindrical tank in U. S.
gallons, square the diameter in inches, multiply by the length
or height in inches and multiply the product by the constant
0.0034.
Formula, D- X H X 0.0034 = capacity
Proof, fi.7sr,4 -H 231 = 0.0034 the constant
Rule — To find the beating surface of boiler tubes, mul-
tiply the diameter of the tubes in inches by their length in
feet and that product by the constant 0.261S.
Formula, !> < 1. X 0.2ms -- heating surface
Proof, 3.1416 cir. h- 12 in. - 0.2618
The EiKhth Annual Report of the District Police of the
State of Massachusetts, for the year ending (let. 31, 1914,
regarding the examination and licensing of stationary engi-
neers, contains the following: The number of applicants
examined for licenses as engineers or firemen was 64ln>. of
which 2955 were granted licenses and 3535 were rejected: for
operators of hoisting machinery 147 were examined, 125
passed and 22 were rejected: grand total of applications,
number licere- i of. 3557
L915
]•() \V E 1!
■!'X
[More "original ideas" sent in by readers in response
our request in the Jan. l'J issue for stories of amusing
ipidity. — Editor. |
In a certain power plant which the writer visits occa-
Hiallv. there is a recording boiler feed-water meter,
line six months ago the nozzle became so stopped up with
e sediment in tin' feed water that the records were
irlhlcss. Nevertheless, the engineer religiously changes
c charts every day and reads the integrating dial, in
ite of the fact thai he knows the nozzle is plugged up.—
mn L. Hebbetd, Milwaukee, Wis.
MssxedUPipessiuiff'© Tsunrlbiiini© siias
The Columbia Plate Glass Co., Blairsville, Penn.,
recognized that the utilization of exhausl steam for
generation of power would effect a desirable saving
coal costs and help the production by giving better
has
the
The following piece ol* rank stupidity is reported "just
lor fun."' We purchased a forced-draft system for a boiler,
which was a miserable failure. When the writer told the
representative of the company the facts of the case lie
hauled out his data sheet and started to lake down the
data which were given him. lie finally asked what kind
of coal we burned, and when told it was pea coal he im-
i liately said: "That's the reason it would not work.
This blower is so delicately adjusted and carefully de-
signed for buckwheat coal that it could not be expected
to work on pea coal." — T. Newbury, Monroe, X. Y.
A 10-kw. dynamo was used to light the mill, and short-
circuits were common. One night a short came on that
nearly threw the belt. I looked the main mill over, but
failed to find it. In a short time it came on again, and 1
finally asked some of the men if they had done anything
to the wiring. One of them said he had put an extension
on a certain light, but had insulated it so that he knew
it was all right.
lie had found a couple ol' pieces of hare No. 12 wire,
also a long piece of rubber tube. lie twisted the wires
together, put them in the rubber tube, attached the socket
to one end, and hooked the other ends on the circuit
wires. lie said he didn't see how there could be trouble,
when they were covered with the rubber tube. — I". ('.
Wood, Copenhagen, X. Y.
"Last week," said a friend of mine, "I was called to
inspect an engine installation that our firm had sold.
Complaint had been made that neither the pump nor
the injector that came with the outlit would work. Wc
had sold engines and boilers equipped with pumps and in-
jectors of this particular kind for many years and never
received any complaints about them. I was rather curious
and somewhat perplexed as to what the trouble could be.
"When I arrived at the plant and the steam pressure
was brought up to normal. I attached one end of a hose
to the suction side of the feed pump and put the other
into a pail of water. The first stroke of the pump emptied
the pail. Then, with a barrel of water I tested out the
pump ami injector and both worked perfectly. There
was only one conclusion to arrive at. and to the accom-
paniment of a few choice remarks the cover over the well
used as a source of water-supply was removed and revealed
the trouble — the well was dry.
"The manager was told that the cost of the lesson that
neither pump nor injector could create water would be an
even $50." — C. E. Anderson, Chicago, III.
Pig. 1. The Mixed-Pressure Turbine Unit
mim/'m/mmn.
Km. 2. A.RKANGO] i:vr of the Turbine vnd Condenser
cilities for output. Accordingly, a 300-kw. mixed-pres-
sure Kerr steam turbine was purchased, Fig. I. It is a
450-hp. capacity, seven-stage, impulse-type unit con-
nected through reduction gears to a 600-r.p.m., direct-
current generator. The exhaust steam from several Cor-
liss engines is piped to the turbine and ordinarily enough
steam is obtained from this source, at a pressure of aboul
one pound above atmosphere, to generate all of the elec-
tricity required in the plant. Whenever the Corliss en-
gines are shut down, live steam is admitted automatically
through expanding nozzles.
296
POWER
Vol. 41. No. 9
The turbine exhausts into a surface condenser of the
water-works type — that is, it is installed in the water-
supply line to the mills, Fig. 2, and this water produces
the cooling effect necessary for a vacuum of "2S in. on its
way to the grinding tables. This feature of the installa-
tion eliminates any pumping of water for The condenser
and makes use of the water which is being pumped. The
condenser is designed for a water pressure of SO lb., the
pressure carried in the mill lines.
The turbine is placed beside two engine-driven gen-
erator sets which haw operated continuously on high-
pressure steam for years. It is estimated that these ma-
chines used about $20 worth of coal per day. so that the
saving effected by the exhaust turbine is about $6000
per year, or enough to cover the cost of the machine in
a period of two years. The turbine operates continuously
twenty-four hours a day. six days a week.
Oil under (i lb. pressure is pumped to the bearing, and
then flow- by gravity to an oil reservoir in the bedplate;
there it is strained and cooled. A small -team turbine-
driven centrifugal pump is bolted on this bedplate and
used for starting the oiling system before the turbine is
started.
Sfor©iag!,{nh off ©as
By .1. E. Terman
Nearly all authorities on boiler construction have ad-
vocated the use of diagonal seams for boiler patches ol
small size. Heine, the common use of the horseshoe and
diamond shapes, where bags or similar defects in the
vicinity of girth seams have made the removal of a part
of the shell plate necessary. The writer has long been
an advocate of such a method of repair and does not
now wish to be understood a- having changed.
However, analyzing diagonal boiler joints in the light
of what is known of the strength of riveted joint-, it
appear- possible that there may be an error in assuming
that such angular joint-, unless occupying a position of
angularity of 15 deg. or more with a line parallel 10 the
axis of the boiler, are superior in strength to joints of
the same design placed on lines parallel to the axis of
the boiler.
It was determined by experiments on riveted joints
made many years ago, that in order to insure the break-
ing of the net section of a double-riveted joint as illus-
trated in Fig. 1. the combined net section of the metal
from A to C and (' to B would have to he about ::u to
35 per cent, greater than from A to /;. With less metal
on the diagonals than indicated, the break would be lia-
ble to occur, as illustrated on the right-hand side of Fig.
1. at the last space between rivets.
There are probably two reasons for the diminution of
strength in the angular section, the first being that the
material is not subjected to true tensile stress, but is
partly in shear and is weaker to resist a -tie-- of this
character: the second reason is. the material can draw
down more readily in the inclined sections than in the
longitudinal. The latter reason i- based on the effect
noted in testing materials, where, if a sample of plate
is tested in the shape which was formerly used by the
F. S. Government and illustrated in Fig. 2. the te-ted
tensile strength would he about 10.000 11). higher than if
tested in the form shown in Fig. 3, which is the stand-
e the area of metal at the time of failure is
greater than would be the ease with the same-sized test
specimen arranged in the form illustrated in Fig. 3.
This increase of area is due to the reinforcing effect
oi the additional metal (Fig. 2) close to the ruptured
section, the radii of the semicircles on the side of the
test specimen being only one-half inch.
Rivet holes in a plate produce the same effect on the
apparent strength of the net section of metal between the
holes as is produced by the semicircles in Fig. 2, and
this eii'eet i- maximum when the line of holes is at right
angles to tin direction of applied stress and diminishes as
the ancle between the line of holes and the direction of
applied -tress decreases.
It is. of course, true, as can lie demonstrated by cal-
culation, that the stresses in a cylinder due to internal
pressure and at right angles to the direction of an angular
joint such as GH, Fig. 4. is less per unit length of joint
than if the joint occupied a position parallel with the
axis of the cylinder, as EF. However, the girth-wise
-tie— is the same in all parts of a cylinder, and unless
the angle between F.F and Gil is such that the net sec-
0
Proposed Tests fob Diagonal skim-
tion of metal from G to II is 30 per cent, or more in ex-
■ e- of the net section of metal from E to F, then failure
along Gil may be expected, if the test result- lor the
strength of angular net sections in riveted joints hold
g 1 in such a case.
It appears that no tests have been made to determine
the effect on it- strength of varying the angle of a joint
with respect to the direction of the applied stress. How-
. it may be inferred from the behavior of the angular
sections between rivet holes in tests made on riveted
joints located at right angles to the applied stress, that if
.-I series of test specimens were prepared as illustrated in
Fig. 5. the rivet holes being drilled the same distance
apart lor each specimen, hut the line of holes occupying
a different angle on each specimen, a- Xo. 1. No. '.'. No.
::. etc., indicated in Fig. 5, the breaking strength of the
different specimens would probably not vary greatly. If
such tests were conducted using a sufficiently wide range
of angles, they would demonstrate in a measure if the
angularity of a joint as commonly used in making re-
pairs is a real factor in determining its strength. It
March
L915
i'o\v e i;
297
mighl be argued thai in such a test the actual conditions
with respect to the stresses applied to a joint mi a cyl-
inder subjected I" internal pressure would not be repro
duced, because in the latter case there would be longi-
tudinal stresses produced by the pressure acting on the
heads of the cylinder. However, by including such longi
tudinal stresses the joint could hardly be expected to shov>
greater strength than when considered without taking
them into account. Also, in the horizontal-tubular type
of boiler, it is possible thai the longitudinal stresses in
the shell along the bottom ol" the boiler are a negligible
quantity. After all is said and done in the matter of
estimating the strength of short boiler seams as used for
patches, we cannot hope to have c e very close to the
true facts in the ease, because the distribution of the
-tresses in the shell or patch, due to difference in the
fitting of the patch and lit of rivets in the holes, would
be likely to materially change the results in every ease.
The intent of this article, as stated at the beginning,
is not to discourage the use of diagonal boiler joints for
patches, but to show that by the usual methods of cal-
culating the strength of such joints there is a possibility
that some of the most important factors entering the
problem have been neglected. It is also probable that
considerable changes in the angularity of such joints
may produce relatively slighl changes in their strength.
The determination of the facts, as regards the effed
on the strength of a tesl specimen when pierced by rows
of rivet holes equally spaced, but occupying various an-
gles with respect to the line of direction of stress, as
illustrated in Fig. 5, would be an experiment easily per-
formed by anyone having the facilities to make tensile
tests on large specimens, and the results would be of great
interest to all engaged in boiler design and construction.
8!
ITireforic]
Modern largi
The writer would add two more properties as being
desirable, although some might, perhaps, consider them
covered by the properties specified by Mr. Etigg. They
are:
7. Resistance to erosion.
8. The ability to withstand sudden temperature changes
without frittering or spalling off.
Technological paper No. in of the Bureau of Stand-
ards gives the melting points of various bricks as follows-
Melting Point,
Chemical
Kin-]
,f Brick
Degre< s 1 Degrees V.
Nature
1 'ireclay
1555 1725 2863-3169
Neutral oi acid
Bauxite
1565-1785 2881-3277
Basic or neutral
Sitiea. . .
1700-1705 3092-3101
Acid
( 'liruiinl.
2050 3754
Neutral
Magnesia
2165 3993
Basic
Iron, silica, alumina, lime and sulphur are the clinker-
forming elements of coal. The degree of fusibility of the
clinker varies directly as the percentages of sulphur, iron
ami lime and inversely as the percentages of silica and
alumina.* The tendency of the iron to combine with
silica in the coal and ash and form a slag is well known,
and a cinder of this kind will have a strong affinity for
the silica in the brickwork. This is one of the reasons
that silica and fireclay brick have a strong tendency to
disintegrate at high temperatures along the side of the
furnace, ('inder in cooler furnaces sticks to the brick-
work, which is often damaged in the attempts made to
bar the clinker loose. AYith certain kinds of cinder it is
possible to feed a small quantity of limestone and melt
a pasty slag free from the side walls. Fluorspar has a
similar effect upon some cinder. Both of these remedies
should be used with discretion and care to avoid fluxing
the cinder to such an extent that it will flow down on
the grate bars and chill there, in which case it will be
more troublesome than in its original consistency.
There is no reason why silica brick should not be used
above the cinder line, for the upper parts of the walls and
for coking arches, where they are exposed to the action of
the flame only. Silica brick are used in this manner in
basic openliearth furnaces and have proved durable.
Bauxite brick have been tried to some extent for tin
side walls of the firebox. These brick cost from two to
three times as much as silica or high-grade fireclay brick.
They are very bard and tough, the cinder does not stick
to them and they last considerably longer than silica brick
where exposed to the action of the slag. They have one
serious disadvantag< — a tendency to spall or fritter oh
if suddenly chilled. In a lirebox this is often troublesome.
The barring doors for the fires arc generally located close
to the side walls, and whenever these doors arc opened a
blast of cold air will be drawn in along the walls unless
the draft can he so well balanced that the furnace is
slightly above or at the same pressure as the atmosphere.
When the furnace is below the atmospheric pressure this
chilling draft results in rapid spalling close to the door
and it nia\ he necessary to shut the boiler down to patch
this portion of the lining long before the rest of the fire
requires repairs. Bauxite brick, even with this disad-
vantage, have proven quite durable, lasting from three to
eighttimesas long a.- the cheaper hrick. Although bauxite
is extremch refractory, it must be almost completely
calcined, otherwise it will shrink excessively af furnace
temperatures. These brick must be burned in an oxidiz-
ing atmosphere, otherwise the iron compounds in the
'See "Metallurgical and Chemical Engineer
•That sulphur causes clinkering is not generally agreed.
The belief that it nas no appreciable influence on clinkering
is on the increase. — EDITOR.
298
p o w e i;
Vol. 11, Xc
bauxite will be reduced and the brick will have a low heat
resistance. Bauxite brick arc frequently considered as
basic though in many ways they partake of a neutral
character. Bauxite is mined extensively as an ere of
aluminum. I be average composition of that from Georgia
is:
, i„ , (Si( .,i 3 f>n pel cpni.
I - . . j i pi roxfdi (Fe.OJ ....... 1 50 per <«nt.
Vlumina i \1 .' ' ) 5S 'u p< r ■•■ni
Water (II-1 ») 32.33 per cent
Titanium "(Ti( >,i I 50 per cent.
Another material used in making refractories which
may possess so possibilities of assisting in building
durable fireboxes is chrome iron ore or chromite. These
brick cost more than twice as much as bauxite brick, but
are neutral in character. This material is infusible and
it is difficult to sinter it thoroughly, and unless thoroughly
sintered it does not stand erosion.
TYPICAL ANALYSIS OF CHBOM'TE
Se quioxide of chromium (Ci'oOa) 35-50 pel cent.
Alumina (A1,0,) . ......" 16-28 per cent.
Iron peroxide (Fc03) 17 per cent.
Silica (Sil K) 1- 8 pel cent
Magnesia (MgO) in- 17 per cent.
Lime (CaO) 1- 2 per cent.
Chrome brick are well adapted to resisf extremely hish
temperatures, though chrome iron ore is variable in
composition.
Wi
.aimgiimig
tl
Om Fremiti
By Gordon Fox
SYNOPSIS - Directions for changing over a mo-
tor into n generator, and vice versa; also a discus-
sion of the relative characteristics when operated
miller these conditions.
Occasions often arise making it desirable to utilize a
direct-current motor as a generator, or vice versa. Most
direct-current motors and generators are very much alike;
the armatures and commutators are identical, the brushes
are the same except as to setting, and the fields are
similar. That the machines are interchangeable is shown
by the fact that if two direct-current generators, A and B,
are operated in parallel (driven from separate sources)
and the engine driving .1 be shut down, its generator will
run as a motor and draw current from generator B.
A motor is, in reality, a ••counter electromotive-force
generator." The armature rotating within the field poles
generates a voltage less than the impressed voltage by an
amount sufficient to allow the load current to How. As the
load increases the motor .-peed decreases, the counter elec-
tromotive force decreases and the current increases. A 230-
volt compound-wound motor may have a counter electro-
motive force of perhaps 225 volts at no load and 213 volts
at full load, the decrease being due partly to the drop in
speed. Consider that the no-load speed of this motor is
900 r.p.m. and its full-load speed 850 r.p.m. If, instead
of driving a mechanical load, the machine were driven at
a speed of about 950 r.p.m. it would act as a generator,
tending to generate more than 230 volts ami pumping cur-
rent out into the line. The armature IE drop must be
subtracted from the line voltage to obtain the counter elec-
tromotive force of a motor but must he added to the line
voltage to determine the generated electromotive force of
a generator. Therefore, as a generator a machine must
run faster than as a motor to operate at the same line
voltage.
As a generator it is further desirable to have a little
leeway for the use of the held rheostat. This necessitates
., greater increase in speed to compensate for the slightly
weakened Held. Moreover, generator voltages are usually
higher than motor voltages upon the same system because
of the line drop. In general it ma\ lie stated that a motor
must lie driven about Id per cent, above its speed rating in
order to deliver rated voltage as a generator. Conversely.
a generator used as a motor upon rated voltage will rotate
about 10 per cent, below the speed indicated on its name-
plate. These figures are at best only approximate, due
to the wide range of characteristics of different designs.
In connecting a compound-wound motor for use as a
generator the only change ordinarily required is the re-
versal of the series field connections. If this is not done
the scries held will buck the shunt held and the voltage
regulation will be very poor. If the direction of rotation
as a motor he unchanged, the machine will build up as a
generator. If the rotation as a generator be opposite to that
as a motor, then it becomes necessary to reverse the arma-
ture terminals in order to enable the generator to build
up. If this is not done, the voltage generated in the arma-
ture through the action of the residual magnetism will
cause the held coils to buck the residual effect rather
than to aid it.
The external connections of a generator differ from
those of a motor, in that the generator requires no start-
ing resistance in series with the armature, but is pro-
vided with a rheostat in the shunt field circuit.
If a shunt motor be used as a generator it will not de-
liver a very satisfactory voltage. The purpose of the
compound winding of a generator is to maintain the volt-
age or to cause it to increase under load. A shunt machine
will drop in voltage from 5 to 15 per cent., under load,
depending upon the design. The voltage can. of course,
he regulated by manual control of the field rheostat. A
compound-wound motor should be selected if possible
where automatic voltage regulation is desirable. Standard
motors are built for 50 per cent, to 40 per cent, compound-
ing effect ; that is. the series ampere-turn- at full load are
20 to 40 per cent, of the -hunt ampere-turns at rated volt-
age. The majority of over-compounded generators arc
designed for a voltage increase of about 10 per cent, under
full load. This requires perhaps 20 per cent, series am-
pere-turns at full load, since generators are ordinarily op-
erated above the knee of the saturation curve where the
series ampere-turns are proportionately less effective.
Therefore, a motor having 20 per cent, compounding is
usually well adapted to run as a motor.
Since it is desirable to have some rheostat leeway for
controlling the voltage, the shunt field will usually be
March % L915
1' u \Y e i;
299
porked at a lower density as a generator than as a motor.
he deficiency in magnetic strength being compensated by
icreased speed. A low density al qo load means that the
mpounding ampere-turns liave greater effect. It will
anally be found thai a compound-wound motor adapted
rator service lias an excess of compounding. This
i a good faull inasmuch as ii is an easy matter to shunt
ie series winding with german silver resistance and thus
ljust its value as desired.
The full-load neutral, or best running, brush position
>r a motor is at a point shifted from the no-load neutral
1 a direction against that of rotation. In a generator
ie neutral shifts with the direction of rotation as the
>ad is imposed. Consequently, if a machine be operated
ist as a motor and then as a generator, the rotation being
achanged, it i- necessary to shift the brushes a consider-
ile distance in a direction with the rotation. On the
her hand, if the rotation be reversed, the original motor
lift against tin1 direction of rotation now becomes ;i gen
■ator shift with the rotation, and further change will
kely be unnecessary. However, if. due to increased
iced, the machine operates as a generator upon a weaker
?ld than it had been running as a motor, the armature
action- will have an increased effect and a greater shift
ay lie required.
An interpole motor is well adapted for use a- a gener
or. If a compound motor is not available the interpole
otor is its best substitute, since the action of the inter-
poles i. -in lie utilized to -nine extent in securing the volt-
age regulation desired. The interpoles of a motor have
the same polarity a- the main pole- preceding them in a
direction against the rotation. The interpoles of a gener-
ator have the opposite relation, being of the same polarity
as the main poles following, in a direction with the rota-
tion. When an interpole motor is i hanged over into a
generator the relative polarity of the armature and the
interpole must he reversed. One armature terminal
is usually connected permanently to one interpole ter-
minal. In making the change it is :essary to reverse
this connection, using the other interpole terminal and
the same armature terminal.
One cause of the dropping off in voltage of a shunt
generator under load lies in the armature reaction. Since
the interpole neutralizes armature reaction, it tends
to thus better the voltage regulation. The regulation of
an interpole generator can he further improved by giving
the brushes a slight shift oil' neutral in a direction against
the rotation. This procedure is in a way similar to shift-
ing the series winding of the interpole over to the follow-
ing niain pole. The magnetizing effeel of the interpole
assists the main pole-, increases their magnetism under
load and. therefore, tend- to maintain the load voltage and
to improve the regulation.
It is obvious that the procedure for changing a genera-
tor into a motor is the exact reverse of that for changing
a motor into a generator.
.im ttlhie Gas ErniElm*
By E. X. Percy
SYNOPSIS — Directions for systematically follow-
ing up the trouble when an engine refuses to start;
and, after having located II"' trouble, suggestions
for remedying it.
When a gas engine refuse- to start, there is usually one
of two things wrong — the mixture or the ignition. It is
best to test out the ignil lir-t because it is easy to de-
termine definitely if the trouble is from this source.
First, test the battery by short-circuiting it with a piece
of wire and note if a fat spark is obtained when the wire
is snapped across the terminals. All engine- with electric
ignition have a timing commutator, regardless of the
system used. Therefore, turn over the engine to a firing
point, and if high-tension ignition is used the buzzer on
the coil should sound. If it does not. it is probably out
of adjustment or the spark-plug points need going over
with a fine file or piece of emery paper. The adjusting
screw should then be turned carefully hack and forth
until the buzzer begins to sound.
After the buzzer is working, place a screw-driver on
the cylinder head and tip it until within about ,',., in.
of the spark plug. If no spark jumps across from the
top of the plug to the screw-driver, the indications are
that either the plug is foul and the points short-circuited,
the connection is broken, or the high-tension cables are
leaking sparks onto the frame somewhere. The farther
the spark jumps the stronger the battery.
One of the most baffling troubles is a weak battery.
This may comply with the usual tests without giving in-
dication- of troubles, yet the spark will not he hot enough
to ignite the mixture in a cold engine, although it may
have been working well when the engine wa- >lmt down.
For this reason, it is wise to use batteries only for start-
ing, after which a generator or a magneto should be
switched on.
Engines having make-and-break ignition should be
tested in the same way. so far as the timer is concerned,
hut there is no buzzer. Instead, a screw-driver or piece
of wire i- .-napped aero.-.- the win' connection on the make-
and-break plug, the other end of the wire being in con-
tact with the engine cylinder. If a fat spark is had in this
way, the igniter may he removed and -napped by hand.
to see it' it -parks. The wire should then be connected,
and the ground side of the igniter should touch the iron
of the cylinder, ('are should he taken that the mixture
in the cylinder is not ignited, or the operator may get
burned. The make-and-break plug may now he returned
to the cylinder and the adjustment examined. In this
connection it should he remembered that the spark is
made when the electrodes separate — not when they come
together — and the quicker they separate, the better will
be the spark. For this reason, slow-speed engines must
have a snap-off mechanism for a make-and-break spark,
while a high-speed engine can get a good spark from an
igniter connected directly to a cam rod, without a snap-
off mechanism.
Having determined that the trouble is not with the
ignition, or having fixed such trouble as may exist, ant]
still not being able to start the engine, it becomes neces-
sary to investigate the mixture. If the engine is operat-
:;oo
r o w i ■: i;
Vol. II. No.
iug on gas of any kind, there is an excellent method of
getting the right mixture into the cylinder. Let the air
gas be m'I as nearly correct as possible under the cir-
cumstances; then draw in a charge by turning over the
engine by hand, and compress it slightly. Open a eylin-
dei pet-cock slightly and apply a match. If the flame
i- smoky, there is too much gas in the mixture; if it is
hard to light, there is not enough gas, particularly if the
lianie is colorless. If the flame is a clear blue or silver.
the mixture is about righi and should ignite. In fact, it
may ignite by striking hack into the cylinder through the
oek, hut lid harm will be done, except to move the
piston slightly. If there is much compression the mix-
ture may blow out of the pet-cock so hard that it will be
difficult to light it.
With carbureting engines, this same plan is successful,
but is attended with risk of fire, because of the tendency
of liquid fuels to colled around the engine, their vapors
greatly increasing the risk. In this type of engine trou-
ble may he expected in starting in cold weather. To make
certain of starting easily, fill the jackets with boiling
water, if possible, and prime each cylinder with one squirt
of gasoline, and fill the inlet pipes with air saturated with
gasoline. If the engine still refuses to start, take out the
spark plugs and drop a lighted match into the cylinder.
first making sun- that there is nothing in the vicinity to
take lire. The cold gasoline in the cylinder will c-
and rush out of the spark-plug hole with a roar, and the
operator must he careful not to gel too close. This is
practically the only remedy for a flooded cylinder, except
to laboriously turn over the engine until it is dried out.
Many of the cheaper engines have no carburetors, but
merely a valve which lets the fuel into the inlet pipe, and
some rough device for cunt rolling the air. They fre-
quently give trouble in starting, no matter how familiar
the operator becomes with them. The best way to start
such an engine is to have the fuel shut off, prime the cyl-
inder, and squirt fuel over the inside of the inlet pipe.
The engine will then start, and run for several revolu-
tions, during which the fuel valve may be opened until
the operation is regular. The reason for this is that this
type of fuel valve usually Hood- the engine when starting,
and a flooded cylinder is decidedly troublesome.
Unless an engine is badly Hooded, it will start on most
any kind of a mixture, hut will not run Ion-, nor will it
develop much power unless the mixture is just right.
Find out first where the adjustments are. then start the
engine by priming, and after it is going, Iced it with the
squirt can with one hand and adjust the carburetor with
the other, until it is fairly under way. Then, when under
load, make the adjustments that seem to do the work best.
H black smoke is given off, the mixture is too rich. This
should not he confused with blue smoke which comes only
from an excess of lubricating oil. There is usually a
small c\,c." of oil in the crank case when the engine is
first started, and for this reason the supply of lubricant
should not he eul down unless the smoke continues for
some time. When the engine misses, and "coughs" back
into the carburetor or inlet pipes, the mixture is too lean,
and more fuel is required. The greatest economy is
SCi ured by using the thinnest mixture that will carry the
load reliably. Mixtures rich enough to smoke are weak,
not strong. The strongesl mixture has been found to be
that which contain- a little more air than necessary to
properly hum the fuel.
There are some two-stroke-cycle engines, mostly small.
that are perfect mules of obstinacy when being started.
The reason is that after the fuel is carbureted it does not
go into the cylinder at high velocity, as in a four-stroke-
cyi le type, but is first detained in a cold crank case, where
the fuel condenses, and air or a very lean mixture
io the cylinder. Also, many of these engines have gauze
in the inlet port to prevent backfiring into the crank case.
This gauze, when cold, condenses much of the fuel, and il
becomes necessary to prime the cylinders in starting, but
it is equally important to refrain from flooding them. A
I method is to draw off all the lubricating oil from the
crank case and replace it with oil which has been heated
until it smokes. This will usually heat the engine enough
to start easily, as the cylinder does not have fo be particu-
larly hot if the crank ease is hot enough to keep it from
condensing the fuel.
In starting a cold engine, it pays to lake the 'rouble to
heat it up by one of the methods suggested, for after such
treatment it starts so easily, provided the ignition is all
right, that the uselessness of tugging and straining is
apparent. The writer has seen engines of |n or 50 hp.
started by pouring a tea-kettle of hot water into the jacket
of one cylinder. Those that give the most trouble are nf
the cheap factory type, without adequate carburetors nr
reliable ignition, yet they are used extensively in contract-
ing work, agricultural machinery, and general small
power work. The gas or gasoline engine is just as reliable
as the steam engine, provided it is made equally well and
receives equal attention and study.
There are now many devices and systems for making
these engines self-starting. These systems, as a rule, are
reliable, hut a man must know his engine just the -
and he able to know that it is in condition to start, before
he risks using up the power stored by the self-starter for.
that purpose.
v
C©Ejapsvip®.ftive Tests of §^©^©2=°
l'.i II. S. Knowltox
Through the courtesy of the engineering department
'•( the Norton Co.. Worcester, Mass.. the following lest
data are given, showing the comparative efficiency of
hand and stoker firing in the boiler plant of this com ern
at Barbers Crossing. This plant was recently equipped
with self-dumping, underfeed stokers, which are compara-
tively new in the field of power-plant equipment. The
figures given arc among the first to lie published upon
their operation. Their most striking features are: In
place of stationary dead plates are moving, air-supplying
urate-, carried by the reciprocating sides of the retort-:
moving overfeed urates extending across the entire width
of the stoker, and pusher noses with ash-supporting plates
for continuously dumping the refuse. This is the only
type of underfeed stoker having live urate surface- and
the continuous automatic dumping of refuse.
A- shown in the illustration, the Norton installation
consists of a set of three-retort unit- per boiler,
steam-generating equipment of the plant having five 300-
hp. vertical lire-tube boiler-. The stokers are chain-
driven from a fan shaft carried alone' the boiler front--.
the fan being loi ated in the engine room to enable il
under th : eve of I eer, besides furnishing ;: means
Man
1 9 1 5
I'd W E \l
;;oi
ixhausting air from (lie engine room and aiding in the
itilation. The fan is 5 ft. <> in. diameter, with three-
irter housing, and is driven by a 7x6-in. vertical in-
sed engine, the maximum speed being t50 r.p.m. The
discharge to the stoker air chambers is through a
terete dud in the floor with a maximum cross-section-
irea of L720 sq.in., each stoker being supplied through
I8xl8-in. branch duct, while the cross-section of the
in duet is diminished accordingly at each boiler. The
speed is automatically controlled by the boiler pres-
I'he boilers are fed with water by a centrifugal pump
li a capacity of 90 gal. per minute, the pump being di-
fc-connected to a/ 20-hp., 440-volt induction motor run-
g 3600 r.p.m. This is about the smallest size of
View of Bom i: Room of Norton Co/s Plant
centrifugal feed pump capable of being operated at good
efficiency, in view of the limitations of water passages.
It is estimated that the steam consumption of the boiler-
feed equipment of the plant has I n cut in half by the in-
stallation of the motor-driven pump.
A fuel licil about 2 ft. thi.k is maintained on the grates,
and above each set of retorts i- a hopper containing 750
lb. of coal.
At a coal cos1 of about $-1 per ton, the equipment of
the five boilers of the plant will pay for itself in about
two years.
In analyzing the tests the Norton c pan] points out
thai they represent an average taken from daily pracl i< e.
While the hand firing is not all it should have been, the
stoker eliminates all i hance of earele sne ■ likely to arbe
in a plant of moderate capacity not equipped with record-
ing instrument maintaining a constant check on the fire-
man. The company has had but one stoker in operation
continuously for about a year, and in that time has had
no expense' for repairs. The design of the working parts
seems well balanced, as no weakness has so far developed.
Thr capacity of the stokers has nut as yet had to be tested,
hut the company is of the opinion that, if necessary,
TEST DATA
Boiler No 1 3
Type of firing Stoker Hand
Date May 14, 1914 June 16, 1914
Time 7 a.m. - 6 p.m. 7 a.m. - H pin
Duration.... 10 hr. 10 hr.
Average temperature feed watei 179 deg. 157 deg
A. verage gage pressure .. 142 lb. 142 1b
Coal burned 8690 lb. S470 II,
Ash . . 72(1 lb. 79(1 lb
Per cent, ash by weight. . 8 9
Watei fed.. 07.20(1 lb. 80,774 lb.
Quality steam, assumed Dry Dry
Water evaporated per lb. coal fired. . 11.21b. 9 53 lb.
Equivalent evaporation per lb coal 12 2 lb. 10 ">7 lb.
Per cent. CO, 10.8 7.6
Per cent. CO 0 3 0.3
Heating surface 3444 sq.fl 3324 sq.fl
( Irate surface 3.", sq.fl 42 sq K
Evaporation per sq.ft. healing surface
per hr 2.8 II,. 2.4 lb.
Evaporation per sq.ft. grate surface
per hi 277 1b. 102 1b.
Coal burned per sq ft. grate surface per
hr 2o lb. 20 1b.
Flue temperature 401 deg. F. 473 .1 1 I
Per cent, combustible in ash 12 42 Not determined
B.t.u. per lb. coal as fired I 1,1,00 14,600
Relative efficiency, per cent 81 70
EQUIPMENT i.\ CONNECTION WTTH TEST
Equipment Manufacturer
Boilers, "Manning" DM. Dillon Steam Boiler Works
Stoker, "Riles ". Sanford Riley Stoker Co., Ltd.
Centrifugal feed pump De Laval steam Turbine Co.
Draft fans B. F. Sturtevant Co.
it could push the boilers much beyond their rating. It
is now doing with three boilers what formerly required
four. This is due to the ease with which the boilers can
he maintained at full rating and better efficiency. When
the coal-hopper installation is complete, with facilities
for overhead gravity delivery of fuel, it is expected that
one fireman will handle five boilers, whereas under the
old methods of hand firing two men were required.
The Storage Buttery is composed of three fundamental
working elements, namely, the positive plate, the negative
plate and the electrolyte. There are several processes used
in the manufacture of the plates, but the one most generally
employed consists in making the positive elements of lead
peroxide (PbO:) and the negative of sponge lead (Pb). The
electrolyte consists of sulphuric acid (H.SO,) diluted with
water (HsO).. The active materials are held in their re-
spective positions by bad grids.
There are various theories in regard to the chemical reac-
tions which take place in a storage cell, but the one most
generally accepted is that the passage of the current upon
discharge causes the acid to react upon the active materials
of the plates, forming in their places lead sulphate (PbSOq),
the reaction being accompanied by a reduction of part of the
acid and the formation of water in its place. This is the
cause of the decrease in the density of the electrolyte ob-
served upon discharge. The chemical formula expressing the
reaction at the positive plate upon discharge is
I., ad Sulphuric Lead
, roxide Acid Sulphate
PbOj + H-SO, - I'bsn,
\v
iter
H..O
Oxygen
+ O
Thai of the negative plate is
Sponge Sulphuric Dead Hydrogen
Lead Acid Sulphate
Pb + H.SO, PbSOi + H2
Upon charging, the current is passed through the battery
in the direction opposite to I bat of discharge, with the result
that the reactions expressed in the foregoing equations are
reversed. The lead sulphate is reduced, the active materials
— lead peroxide and sponge lead — are restored to their re-
spective plates and the acid taken from the electrolyte on
discharge returns to it, the water previously formed disap-
pearing. This replenishment of the electrolyte causes the rise
in density observed upon charging
302
P UWEG
Vol. 41. N(
or4y Years9 Advance imi S4eama
'©weir
SYNOPSIS — Comments on the accompanying
graphical comparison of the Centennial Corliss en-
gine with a turbine of the same power, showing
its relative size, and a turbine of the sunn size,
giving its relative power.
In the account given of the Panama-Pacific Exposi-
tion in last week's issue reference was made to the big
Corliss engine which was a feature of the Centennial
Exposition at Philadelphia in 1876. This was in con-
nection with an outline of the advance which has been
made in steam prime movers since that day. The ac-
companying page illustration shows this progress of forty
years graphically and gives briefly some of the more im-
portant data respecting the three units shown, The story
is Qoi complete in that it leaves out the chain of steps
in the evolution, but it was not the purpose to portray
this. Rather was it the intention to contrast and com-
pare the old Centennial engine with the turbine form
of prime mover, which is generally adopted today where
large power capacities are desired in the space allotted.
Directly beneath the Corliss engine is shown a turbine
of equivalent power, reproduced to the sa scale rder
to compare the relative sizes of the two machines. In
other word-, they are shown as the two machines would
actually appear when viewed at the same distance from
the observer. At the bottom of the page is shown, also
to the same scale, another turbine, the largest at pres-
ent in operation. The comparison of spaces required by
the three units is unfair to the turbine- in that they
are complete electric generating units, whereas the Cor-
liss engine shows only the steam end. its output being
purely mechanical energy — lor direct-connected steam-
electric unit- were unknown at that time.
In the article of last week mention was made of the
manner of distributing the power from the Centennial
engine through an elaborate system of shafting with both
gear and belt drives. This needs no repetition for the
present purposes, but more in detail i- in order concern-
ing the engine it-elf. which will include some of the prin-
cipal facts already given.
The Centennial engine had its cylinders and means
of connection with the single flywheel, in duplicate, so
that it was strictly a pair of beam engines, although con-
nected as one unit. George II. Corliss, of Providence,
E. I., was the inventor and manufacturer. The engines
were designed to work expansively, with steam at an in-
itial pressure up to SO lb. The valves and valve gear
were Corliss type with several improvements specially
designed for and first applied to these engines. The
cylinders were 10 in. diameter and the stroke Ml ft.
Each of the beams wa- 21 ft. long by 9 ft. deep and
weighed 11 tons. The flywheel, to the shaft of which
the engines were connected at right angles, was a cut-
gear wheel 30 ft. in diameter by "2 ft. face width and
weighed 56 tons. Tt made .".(i r.p.m.. giving a piston
speed of 720 ft. per mill.
The pinion which the flywheel drove was 1(1 ft. diam-
eter and weighed 8y2 ton-. This rotative -peel is in
marked contrast to that of both the turbines, which is
the big factor in accounting for the disparity of sizes be-
tween the two type- of machine. It is a fundamental
law that the power developed increases as the speed so.
naturally enough, increasing the speed a hundred times
means a greatly reduced size of prime mover.
An interesting comparison, if it could he made, would
be that of steam consumption per horsepower-hour, but
unfortunately Mr. Corliss would not allow the figures to
be given out for his engine, if indeed they were ever de-
termined by tc-t : but doubtless a better economy would
have been shown by the Centennial engine in spite of the
lower steam pressure used, the absence of superheat in
the steam, and the use of live steam in the cylinder jack-
ets. The engine developed 1 100 hp. and could lie driven
up to 2000 hp. when required. The platform on which
the engine stood was 55 ft. diameter, or 2376 sq.ft.
area, so that it is fair to consider this as the floor space
occupied. The total height was :i!i ft. ami the total
weigh! ;oO tons.
Striking by contrast are the figures for the turbine
of the same power shown beneath the engine. As before
stated, it runs at 100 times the speed, or 3t)00 r.p.m..
but it occupies only ' ,, the floor space, or 110 sq.ft.,
and weighs about g'3 as much (22 tons). Its height is
less than J - as great ( ) ft.), but it uses nearly twice the
steam pressure (150 lb.). The turbine shown in this
instance is of the Curtis type, as built by the General
Electric Co., rated at 1000 kw.. which is very nearly
the equivalent of ] 100 hp. If anything, the turbine is
more powerful than the engine, for the brake horsepower
developed by the turbine would he more, there being some
loss in the transformation to electrical energy through
the generator.
The picture at the bottom v( the page is that of the
30,000-kw. so called cross-compound Westinghonse-Par-
soiis type turbine built by the Westinghouse Machine Co.
and the Westinghouse Electric lV .Manufacturing Co. for
the [nterborough Rapid Transit Co.'s Seventy-Fourth St.
station in New York City.
In some ways it makes a better type to compare with
the engine, for it is also practically two machines and oc-
cupies very nearly the same floor spact — 51 by 40, or
'.'0 10 sq.ft. Therefore, whereas in the first case the Cen-
tennial engine was compared with a turbine of the same
power, here it is compared with one of the same size and,
incidentally, nearly the same weight — 000 tons. The
power, even allowing for no los-es between the turbine
and its generator, is seen to be nearly •.".) times as great
(40,200 hp.), the steam pressure \M L. time- as much
C'oo lb.) and the speed of the high-pressure rotor 42
time- as much (1500 r.p.m.) and that of the low-pres-
sure rotor '.'1 times as much (I.jO r.p.m.).
The use of two speeds is a notable advauce in the de-
sign of this form of prime mover. To get the most suit-
able blade speeds for both the high-pressure and the low-
pressure steam in elements all on one shaft and avoid
severe stresses, involves mechanical difficulties. Using
a high speed for the high-pressure element and a slow
speed for the low-pressure overcomes these difficulties.
March 2, L915
I' U W E E
303
^^ENTOFSTEAM-PCTO
-rue ILU
„5Twr.ONS M* ^RAVeO IN m SAHt BtLATlVe PROPORTION *THt DlMtHS1ONS OPTHt ^
CYLINDERS
R# Diameter 40 in
/ Stroke 10 ft.
GEAR FLYWHEEL
Diameter 30 ft
Face 2 ft.
Weight 112.000 lb.
PINION
Diameter 10 ft
Weight 17.0001b.
WALKING BEAMS
Length 27 ft.
Width at Center 9ft.
Weight 22.000 ib
Platform Diam
Total Height
V
55 ft.
39 ft.
Total Weight
1.400.000 lb
Steam Pressure
25-601b.persq.in.
Speed 36 r.p.m.
hP- CENTENNIAL COELI55 EN°
A
Length 17 ft.
Height 7ft.
Weight 44.0001b.
•v m
*4oa
Steam Pressure
150 lb.persq.in.
Speed 3600 r.p.m.
1#
P- curtis-type TURbo -gene^0"
°J
Length 51ft.
Height 13 ft.
Weight
1.800.0001b.
Steam
Pressure
200 lb per
sq. in.
A
SPEEDS1
High- pressure
Rotor
1500 r.p.m.
Low-
pressure
Rotor
750r.p.m.
°\ ^ARSONS-TYPE TURBO-GENE^
:'.04
P OWE R
Vol. 11, N.
In addition to the dissimilarity dimensioually, there
is not the slightesi resemblance in form between the
machines at the bottom and top of the page, yel within a
period of forty years both have been designed to perform
the same work — to convert the heal energy in steam into
work.
Some of the advantages which the later form lias over
the earlier have been mentioned. Another is its ability
to use steam at very low pressures, say 26 to 29 in. vacu-
um. The reciprocating engine becomes prohibitively un-
wieldy when it carries the expansion of steam into a
very high vacuum, and the excessive condensation off-
sets the desirability of low exhaust pressures. That is
when the turbine as a coworker with the engine comes
in, and in the future we shall probably see mure and
more of the combination units — reciprocating engines ex-
hausting into steam turbines. Thus are the rivals be-
coming partners.
N
V©Ms\.§f© OaE Swl&elhie©
Low-voltage current is usually employed to trip high-
voltage automatic oil switches on the occurrence of ab-
hand-operated switches alternating current is generally
used. In many instances, however, neither low-voltage
direct current nor alternating current is conveniently or
cheaplj available, in which case automatic protection is
secured by the use of a high-voltage series trip.
For this service the General Electric Co. has developed
an arrangement representing an improvement on types
of high-voltage series tripping devices heretofore in use.
The new features are accessibility of the working parts
for inspection, cleaning or adjustment while in service,
without danger; calibration at the oil switch itself and
not at the insulator supporting the series tripping
solenoid; and the use of a new type of solenoid, consist-
ing of a lew simple and rugged parts that need practical-
ly no attention after installation.
The solenoid plunger is connected to the tripping
mechanism of the oil switch by a wooden rod. Calibra-
tion, that is, change in current tripping values, is ac-
complished by a movable weight located near the operat-
ing mechanism of the switch, at a considerable distance
from the high-voltage current.
This type of series trip is furnished for instantaneous
or inverse time-limit operation. Time delay is obtained
l'\ means of a dashpot mounted on the tripping
mechanism at the switch.
Go©dl Service frotna
The illustration shows two brine pumps at the plant of
the Independent Tacking Co., Chicago. One of these
unit- ha- been working 24 hr. per day for nearly a year
normal condi
are intended
arc iiMiallv t
t ion
to
rippt
again
»uard.
1 hv I
it with
Series
>t which
Electric
[irect
The Pump Heavily Frosted
without a stop for repairs. Covered with four to live
inches of ice, it has run continuously at aboui 900 r.p.mj
against a head of 20 hi.
The pump is of the two-stage, all-bronze centrifugal
type, made b) the American Well Works. It has a
capacity of .">()() gal. per minute and is driven by a \ar-
iable-speed direct-current motor. When starting the brine
fhrougb the system, the pump requires about 21 hp.
The speed is boosted to 1300 r.p.m. and the head is about
80 lb. When the brine is in circulation, the speed is
the automatic features lowered and only about 8 hp. is required to drive the
ally operated switches pump. The second unit is held as a reserve, as there is
rent, and for tripping danger of freezing the system.
Triple-Pole, Time-
riup
March 2, 1915
POWER
30:>
I.il. , I. , , , .:!;.!
HIT!'! II 1 Illlllll'i'lllllllilllllll ' I I'llMi:
The need of adapting the fuel to the furnace and vice
i has long been recognized. Adapting the refrac-
tor}' lining of the furnace to the temperature ranges and
character of fuel is, at most, rneagerly practiced, if at all
in boiler work. It is common to line the furnace with
one kind or grade of refractory material, yet the brick in
act with the fuel and ash is subjected to conditions
never imposed upon that above the fire line. The latter
i- exposed chiefly to high temperatures only, while that
> . besides being highly heated and carrying the load
due to the weight of the brick above, is subjected to the
■ hemical influences of the slag of the fused ash. Clinker
tends to stick to the brick. When hit with a bar to loosen
it. the brick is usually broken away where the clinker
joined.
It would seem worth while, as pointed out on page 297,
to use in most plants a highly refractory, tough, non-
frittering though expensive brick for that part of the fur-
nace lining below the fire line, while a cheaper grade
could be used above. The coal that will give the greatest
number of pounds of water evaporated per unit of cost is
best for the plant. Should not the refractory material
that will give the longest service per unit of area or
volume per unit of cost under the existing furnace tem-
perature ranges be most suitable?
v
Fuel is capable of producing energy because it has
the capacity of combining chemically with something,
the union producing heat. The rise in temperature is
simply an increase in the. velocity with which the molecules
move.
If a weight is in contact with the earth it has no in-
herent energy with respect to the earth. It cannot fall.
Place it at an elevation, and it has potential energy which
it can exert in other forms, as does the hammer of a pile
driver or the weight of a clock.
The atoms of carbon and hydrogen in fuel attract, and
are attracted by, atoms of oxygen, as the earth and the
weight attract each other. When this attraction is suffi-
cient, as in the furnace, to overcome the existing arrange-
ment they rush together, gathering velocity and momen-
tum, as doe- the weight falling to the earth. The] do
not impact and lose this velocity, as do the weight
and the earth in overcoming the resistance of yielding
substances or setting up molecular vibration at the point
of contact (the heal of impact), but vibrate about each
other like miniature planetary systems, with a vastlj
increased velocity. Their temperature i- a function of
this velocity and their mass; a measure of their momen-
tum.
When they come in contact with the molecules of the
boiler plate they set them into more active vibration, and
this vibration is passed on to the molecules of the water,
inciting them to such rapidity of motion that they break
away from each other and fly off, like stones from a sling-
shot, impacting upon the walls of the containing vessel
and producing by their bombardment that which we
recognize as pressure.
The gases, cooled (having imparted a part of their
velocity or momentum to the atoms of the heating sur-
face), pass off to the atmosphere. They are in the con-
dition of the weight and the earth which have come to-
gether; the clock which has run down. They cannot get
up any more velocity or momentum in themselves by fall-
in »• any closer. How. then, are they to be separated that
they may be again available as media of energy?
When the carbon combines with the oxygen they form
carbonic-acid gas, the gas which makes the bubbles at the
soda fountain and gives the sparkle to wine. When hydro-
gen combines with oxygen they form water. To decompose
the carbonic-acid gas or the water, that is. to dissociate
these molecules into atoms of carbon or hydrogen and
oxygen, takes as much energy as is generated by their
combustion or coming together.
And here comes in one of the most wonderful, beau-
tiful and mysterious of Nature's processes, described in
this way in an old school chemistry, the name of the au-
thor of which we do not recall : It is a peculiar property
of vegetation that under the influence of sunlight it can
overcome the attraction which exists between the atoms
of carbon and oxygen, appropriating the carbon to its own
use, building it into its structure, and letting the oxygen
go free into the atmosphere. To separate these elements
in our laboratories, we are obliged to resort to the most
powerful chemical agents and to conduct the process in
vessels composed of the most refractory material, under
all the violent manifestations of light and beat: and
we then succeed in liberating the carbon only by shutting
up the oxygen in a ^till stronger prison. But under the
C|ttiet influence of the sunbeam, in that most delicate of
all structures, a vegetable cell, the chains which unite
together the two elements fall off, and while the solid
carbon is retained to build up the organic structure, the
oxygen is allowed to return to its home in the atmos-
phere. To separate a pound of carbon from the oxygen
with which it unites in burning would require the ex-
penditure of an amount of energy which would raise the
weight of a ton to a height of over a mile, and yet, in
the economy of Nature, this process is constantly going
on, not with the noisy demonstration of prodigious effort,
but quietly, in the delicate structure of a green leaf wav-
ing in the sunshine.
The mosi promising direction in which to look for a
more direct or rapid process than that of waiting for fuel
to be produced by the slow growth of vegetation is through
the discovery of the secret of the vegetable cell, and the
application of the sun's energy either to the direct pro-
duction of other forms or to the synthetic production of
fuel. At a meeting of the French Society of Civil Engi-
neers some time since. M. Daniel Bertholet said that,
working in conjunction with M. Gaudechon, he had sue
306
P 0 W E R
Vol. 11, Xo. 9
eeeded in producing the principal sugars by acting with
ultra-violet light on a mixture of gaseous carbon dioxide
and water. In a further set of experiments compounds
of carbon, oxygen, hydrogen and nitrogen were produced
by acting with these ultra-violet rays on a mixture of
carbon dioxide and ammonia. In these conditions the
carbon dioxide is decomposed just as it is by chlorophyll
under the action of sunlight. Activity in this direction
would be much more promising than that in the direction
of the fuel mixtures, of the rise and decline of which so
much has recently appeared in the public prints.
B?Le©p>aE&§£ TTVaelhl of P!s\ini&
Opeirsiftloaa
Plant revenue is derived from plant output, but for
many years the switchboard output was the only thing
about the plant that was metered except where the local
authorities applied a water meter to the service pipe. Of
course, the monthly payroll, repairs and the cost of fuel,
oil and supplies were recorded, and in a few cases the
weight of the coal Bred was noted. Occasional indicator
diagrams were taken on the engines, and some plants were
tested when new. Records along these lines were at one
time considered the last word in refinement, although
there were some who strenuously maintained that there
was a big gap between the grate bars and the switchboard,
where serious plant losses might occur undetected. One
of the difficulties to be overcome in isolating these losses
was the supposedly fragile nature of the instruments re-
quired and their unsuitability to the boiler room.
When the steam turbine came into general use in cen-
tral stations the steam-engine indicator retired, and then
there really was nothing between the grate bars and the
-witehboard to tell what was happening except the re-
cording steam-pressure gage. The first instrument to
become a factor in boiler-room operation after this was
the CO, meter. This revealed many sources of leakage
and expense without adequate return and put a premium
upon complete combustion. The Orsat apparatus revealed
high oxygen and checked the combustion recorder. Be-
tween the-e two lies the responsibility for a general ad-
vance in fire-room practice and the patching up of boiler
settings. The disadvantage resulting from porous brick-
work brought the marine type of setting to the attention
of power-plant engineers, and sheet-steel casings are not
uncommon in modern practice.
Extended experience, however, showed that there were
still uncovered sources of waste. High I 0 tsionally
failed to be an accurate index of economy, particularly
where a number of boilers were employed and premiums
paid. Instances occurred where it took more boiler- to
carry the load than were absolutely necessary, or low steam
pressure somewhere was revealed by an unexpected jump
in the load curve. The investigation of uptake tempera-
tures and draft pressures furnished a partial cure for the
trouble, but the final check was the use of the steam me-
ter and the feed-water meter.
Incidental to the introduction of these instruments
came the close study of boiler settings, boiler output and
the possible increase in power output, increase in grate
area and large boilers. It took years for the metallurgi-
cal engineer to learn that the low-roofed furnace designed
to force the heat into the bath by close contact with the
flame was a mistake, lie raised the roofs of his furnaces,
gradually learning that the larger combustion chamber
and the radiant heat resulted in economy of fuel and re-
duced roof repairs. Today the same lesson is being brought
to the attention of those interested in boiler output along
economical lines. The published tests of the Delray boil-
ers and the tests and operating results secured in the new
Cleveland municipal plant indicate what the boiler room
can do.
ILa<c©ims® ILegfasIlgs&aoia asa Mas.§§gv=
It limits to knowledge of
operation the examination of
applicants for licenses t<§
operate.
It limits to knowledge of
engine operation the examina-
tion of applicants to operate
engines.
A new engineers' license law (House Bill 1111) i> be-
fore the Massachusetts legislature and is occasioning a
great deal of interest. It appears under the patronage
o! ;i voluntary committee, which has headquarters in
the Sears Building, a secretary in the person of Richard
11. Stanley, and representatives from the paper, pulp, cot-
ton, woolen, metal-working, quarry and lime industries,
and the boards of trades. The difference between the
present and proposed laws is thus set forth by the prop-
agandists :
PRESENT LAW PROPOSED LAW
It recognizes no difference It recognizes much differ-
in the risk oZ operation be- ence in the risk of operation
tween steam engines and between steam engines and
steam boilers. steam boilers.
It fails to determine the It determines the scope of
scope of examinations and to examinations and requires
require them to be uniform them to be uniform through-
throughout the state. out the state.
It permits the requirement
of knowledge of the principles
of design in the examination
of applicants for licenses to
operate.
It permits the requirement
of knowledge of the princi-
ples of design of boilers in
the examination of applicants
for licenses to operate en-
gines.
It permits the examiner to
require involved mathematical
calculations, thereby denying
employment to competent
men.
Complex and difficult to un-
derstand.
The bill appears, probably from oversight, to tail to
forbid the operation of engines between twenty-five and
one hundred and fifty horsepower without a licensed en-
gineer, and is evidently designed to forestall any attempt
to restrict the supply of available engineers and firemen
by subjecting them to an impassable examination and to
the requirement of a licensed man for everything about
the power house from superintendent to coal passer.
Another bill (House Bill Xo. 19) puts into effect, if
passed, the recommendations of the Chief of District Po-
liee with regard to the examination ami certification of
inspectors of boiler-insurance companies.
Sosrsae Dattes to Meimeirialbeir
lv. . 15, L912, Hall of Records Test begun.
Dec. 15, L913, Hall of Eecords Test finished.
.Mar. "?, 1915, Advisory board of engineers still de-
bating.
Would fourteen months of silence have followed the
conclusion of the test had the figures favored the New
Edison Co.5
It prevents the examiner
from requiring involved math-
ematical calculations.
Simple and clear.
.March %, L915 I'OWEB 307
llllll! III! II I If! lllllljlllllllllllllllllllllllllllllllllll Illllllll Illllllllllllllllllllllllll llllllllllllllllllllllllH'i II Illllllllllllllllllllllllllllllll Illlllllllllllllllllllll IIHIIIIIIIIIIIIIIIIIIIIII Illlllllllllllllllllll Illlllllllllllllllllllllll I IIIIIIIIIIS
>mi(S<
-
At present there is much needed discussion of safety
in refrigeration plants published in Power. The use of
safety valves does not meet with general approval, and
there are several g 1 reasons for this. Alter a safety
valve has been set to operate at a certain pressure, say
300 Hi., it may be a long time before the pressure from
any cause will reach a point that will cause this valve to
open. All ammonia plants are troubled with dirt, scale
and chunks of litharge and it is almost impossible to
To Compressor,
?^j 't j^nmoma end
Ammonia Pressure Raises tin Governor, Giving
Earlier Cutoff, Thereby Reducing the
Compressor Speed
clean these completely out of the piping system. Some
of this foreign matter will be carried along with the es-
caping ammonia and deposited on the seat of the safety
valve, preventing it from closing tightly, though it be
of the best design. The idea of using a body of water
as an absorbent has been completely answered by Mr.
Fairbanks, of Boston (see Power, Dee. 15, pp. 849 and
»6), and the writer will not touch on that point here.
The various laws of different states regulating the opera-
tion of steam boilers (notably those of Massachusetts,
which some consider to be the best) are useless unless
strictly lived tip to. This is mentioned only to illus-
trate that, no matter what safety device may be ordered
by law for the safe operation of refrigeration plants, that
device will be of no avail unless it is of such design that
it ean be easily looked after and kept in good working
onler at all times.
Investigation of numerous accidents to refrigerating
plants has proved that a large percentage were due to
the carelessness of someone operating the plant. The
most destructive accidents may be summed up as those
caused b\ excessive pressure from the loss of cooling
water on the condenser, not opening the discharge valve
from the compressor tp the condenser after the former
had been pumped out for packing the rod or other re-
pairs, or from a heavy charge of liquid being carried
over from the low-pressure side of the system, and in a
lesser degree the breaking of a follower plate or a valve
stem, which in either case must cause the destruction
of the compressor regardless of any and all safety de-
vices on the market.
1 make it a practice to replace all suction valves that
open into the compressor, after they have been in con-
tinuous use two years. This is done on the assumption
that the constant hammering that they are subjected to
must cause crystallization. In fact, I once broke a valve
stem that had been, as near as I could learn, in con-
tinuous use about five years, by striking it a sharp blow
with a small hammer. Within the past year one of our
compressors developed a badly cracked follower. I men-
tion these things to show that fatigue or weakening of
parts is a cause of danger that cannot receive too careful
consideration by owners and operators.
There are two devices for preventing an excess pres-
sure being generated in a refrigeration system that have
come under my observation. One consists of a small
safety valve piped directly from the compressor cylinder.
that discharges into a cylinder fitted with a piston, the
crosshead of which engages the governor stem. When
the pressure in the compressor cylinder exceeds a prede-
termined point, say 200 lb., the safety valve admits am-
monia to the pressure-regulating cylinder, lifting its
piston, which in turn lifts the governor spindle and dis-
engages the hooks so that the steam valves cannot be
opened bj the valve gear, and the engine comes to a stop.
This works well on a machine with one -team cylinder,
as this device has no method of breaking the vacuum, as
in a compound condensing machine. Tt is not as quick
in action as the method now employed by the writer and
which has given satisfaction for over si\ years. The
refrigerating machine has an engine stop, ami the ends
of the ammonia compressor are piped to a pressure gage
•o designed as to permit the use of the pointer as an elec-
tric switch to close the electric circuit putting the engine
stop in motion. This action closes the throttle and breaks
the vacuum, stopping the machine in as short a time as
seven seconds. The device is adjusted to operate at 200
lb., and in very hot weather, when the working pressure
has been close to that point, it has been found impossible
308
P O W E R
II. No. 9
to keep the machines in operation until the head pressure
had been lowered. The stop is also equipped with ;i re-
mute control, with six stations located in different parts
of the engine room and one general station outside the
building, where, by breaking the glass and pulling down
a lever, the power planl ran be brought to a standstill.
\ system of this kind that prevents the generation of an
-ive pressure in the refrigerating system is the best
means of promoting safety in handling large quantities
of ammonia.
In case of a fire that would be likely to destroy a build-
ing used for refrigeration purposes, there would be little
choice between blowing the high-pressure ammonia from
a pipe ten feet higher than the building and allowing the
building to collapse, bursting the ammonia pipes. It is
commendable practice to carry ammonia relief pipe- to
i he top of the smoke-stack.
il. W, Geake.
Xew York City.
'. '.
ClhiSiinmlbes3
About two years ago a combustion chamber on one of
our 1000-hp. gas engines cracked [rom top to bottom, a
distance of about 14 in. This engine is used as an
auxiliary and has not been run very much since then.
When the crack firs! developed, the cylinder could be used
by starting the engine with no water in the jacket, the
crack closing by expansion due to the increased tempera-
ture and preventing the water from entering the cylinder.
The opening seemed to become larger, however, and
finally the cylinder could not he used at all.
A.t first it was though! nseless to try to repair the break,
but later, representatives of two welding firms were con-
sulted. One agreed to weld the .rack at an exorbitant
figure, but would not guarantee the job; the cither ex-
pressed the opinion that it could not be repaired.
After this I asked permission for a trial at repairing
it, which was granted. T began the job with Smooth-
On cement and %-in. Norway-iron studs. The second
hole was drilled so as to cut into one-third the diari
of the first, and so on all the way up the crack. The
studs were screwed in with the iron cement, cut off and
-lightly peened. The repair proved successful.
J. B. LiNKKi;.
Charlotte. N. C.
Sftsiirtiir&gf a StnasvM Motos1
In the Jan. I".' issue Walter S. G-riscom tells of difficulty
in starting a small motor. This trouble was undoubted-
ly due to a weak field, which in turn, was probably caused
by low voltage at the motor terminals, due to drop re-
sulting from a long length of small wire or bad or loose
connections. Such a drop will be aggravated by an in-
crease in amperage, and a shunt motor under these con-
ditions may have little field strength and possibly not
enough torque to start the motor. Putting resistance
in the armature circuit would partially overcome this
difficulty, but I fail to sec the necessity for leaving the
lamps in circuit after the motor is up to speed.
Several years ago a motor-generator was set up and
opi rated in our plant by a young fellow who didn't care
to have anybody advise him. He was never able to start
the machine without help and a careful manipulation of
the -tailing box. The machine was later turned over
to me, and I found that the connections on the starting
box had been made so that the field was in series with
the starting resistance. After changing this the motor
started promptly.
I have also seen the experiment tried of electrically
connecting two 50-kw. shunt-wound machines while idle,
and attempting to bring both up to speed together, one
acting a- a generator and the other as a motor. The
main circuit-breaker would invariably trip without notice-
able indication on the voltmeters or without producing
appreciable torque in the second machine.
II. L. Strong.
Yarmoutln ille, Maine.
WSao Gets ftlh© Fipoatmotaosa?
Concerning the Foreword in the issue of Dec. 15, I'-'ll,
and Mr. Farnswortb'- deductions on page \'r!. issue of
Feb. '.'. 1915, I can see no reason for saying that only
nne of the men has made preparation for the position!
Neither can J agree with him. that the manager has no
light to consider hi- own likes or dislikes in the matter.
I think that any engineer will agree that he can do a whole;
lot better with a plant where he is on good terms with
the bos- than otherwise. A man who is popular with
his mates will be more likely to have harmony among his
men when he gets to lie the chief than a man who is ill
tempered, surly or just plain cranky. I say this from
experience. Neither will they resent his authority as
mill ii as they would if he were a grouch. I have heard
men say behind my back when I was foreman: "Yes,
he look- and acts like a kid when he is playing with the
boy-, but when the whistle blows he knows how to handle!
bis men. and if he tells you to do anything, you had bet-l
ter do it." I could skylark with the boys or men of myl
crew outside of working hours and maintain discipline
among them when on duty, and I have the reputation of
getting the best possible service from my men.
Because a man is grouchy, this does not unfit him for
the position, but everything else being equal, the cheer-
ful man will have more harmony and stand a better eham e
of success. Personally, I would feel more like doing my
best for the man who would treat me like a chum than I
would for one who would hardly sav "Good morning"
civilly.
If a man is steady, sober and honest, does it not - ounj
for many points in the promotion game? Of cour-e. if
these are the only points they are not sufficient, but if
he has seen long service he must have acquired consider-
able ability. Of course, there are men who make good
assistants but very poor chiefs, and the ideal chief is
who will combine the good qualities of all three: such
men are born, however, not made, and this j- the reason
that we often see a young fellow installed as chief while
hi< assistants are double his age and experience, vet lack-
ing the knack of control.
However, all this does not help the manager to deride.
but if I were in hi- place 1 believe I would choose the
one with the cheerful temper if I liked him personally.
I think being a hustler doe- not imply being always
hurrying or on the run.
A. A. l'o \\r:i\i:i).
Oxford. X. J.
March 2, 1915
P 0 W E R
309
Motes <d>k& Sim die Sift os3 Dasi^ifSifflms
While it is obvious that the indicator diagrams shown
n I'iuvkh, Nov. 3, 1914, p. 650, are due to a slipped
ccentric, it is not evident that the rod is out of adjust-
lent. Granting that the diagrams were taken from an
ngine with a simple slide-valve, both adjustments are at
milt. While the data given are not complete, it is pos-
ible to show that if the shaft were 4 in. in diameter, the
ngineer would need to lay off with dividers 23/m in- am1
dvance the eccentric that amount. For the engine in
uestion this would need to be multiplied by the ratio
f the diameter of its shaft to -1 in.
rect setting as indicated, but with the same terminal pres-
sures. In the original diagram, Fig. 1, the atmospheric
line is about 51/, lb. too high. It should be where the
dotted line is, though this does not affect the diagram so
far as valve analysis is concerned. The crank-end dia-
gram is similar.
3
Per Cent. Stroke
A - 25 F - 19 % Near dead center.
Cut off. . . ...... B - 84 D - 81 G - 32%
Release . . . C - 78 E - 64 Near end of stroke.
Compression J - 2 E - 0 H - 72%
Interesting freak diagrams, Figs. 4 and 5, are from
the head and crank ends of a 7%xl5-in. piston-valve en-
gine, normal speed, 220 r.p.m. This 35-hp. engine was
FI6.5 FIG-6
Some Rather Peculiak Indicator Diagrams
This is easily done graphically by drawing the shaft
circle to scale and a 4-in. circle concentric with it. Lay
off on the latter a chord as given and continue radial lines
through its ends to the shaft circle. It would be easier
in laying this out on the shaft to use two chords of l^V
in. (on the 4-in. shaft) instead of one. This ratio is the
scale factor of the diagram used to get the data given
below. The rod should also be lengthened fa in. multi-
plied by this ratio.
Since no information is given regarding the compound-
ing of this engine, no speculation has been made concern-
ing the action of this low-pressure cylinder or the effect
on the revised diagram. Figs. 1 and 2 show the original
diagrams traced with events marked. Fig. 3 gives the
■card obtainable under favorable conditions with the cor-
not running over 100 r.p.m. at the time the diagrams
were taken. Fig. 6 is from the head end taken after
setting the valves. The crank-end diagram is sim-
ilar, though at this time it was not quite as perfect.
Diagrams 7 and 8 were taken under similar cir-
cumstances from the same engine. This condition of the
valves is one that might result from the breaking of an
inner valve ring, where the ring caught between the two
valves and slipped the rods and the eccentrics — an acci-
dent that has occurred on this type of engine.
To those interested in valve setting, these diagrams
should claim attention, for to correct faults it is often
necessary to locate all the events, though the action is
complicated here by the relative movement of the two
valves.
310
P 0 W E R
tl, No. 9
The valve gear is such that the main valve is indi-
rect, as it takes steam on the inside, lias a travel of 2%
in. and a nonreversing roeker. The eccentric is some
thirty inches behind the crank.
The rider valve eccentric is about thirty degrees ahead
id' the crank when the governor is down and some ninety
degrees ahead when running light. Its valve is also in-
direct, as its motion is reversed by a rocker pivoted at its
center to the center of the main valve rocker. The valve
takes steam on the outside and its travel, both relative
and absolute, varies. The latter is about 3% in. when
the governor is down and may be from 4 to 4% in. when
carrying a load, varying with the load and with the set-
tin--.
Because of this variable valve travel a valve diagram
does not represent the movements of the parts as well as
it does for the simpler valve gears, such as the Meyer.
The results of a Zeuner diagram for the first two dia-
grams may be of interest. Taking, for convenience, a 4-in.
valve travel and a connecting-rod five times the length of
the crank, it is found that the events check as shown. For
the final setting, which was made for y64-m. lead on the
head end and for equal cutoffs, we have the following:
Port Port
Steam Opening Opening
Admis- Com- Lap, Dead, Steam, Exhaust,
End sion Cutoff Release pression In. In. In. In.
Head 0 32 99 72 lfj A A J
Crank 0.5 32 99 68 1H A H A
These port openings are the maximum possible and
must be compared with the actual ports to get under
travel. All dimensions, except the percentages of stroke,
must lie multiplied by the ratio of the actual valve travel
to 4 in.
A. E. Nottingham.
West Lafayette, Ind.
The editorial, "The Wrong Slant,'' in the Dec. 15 num-
ber, calls attention to the status of the steam engineer
in most factories. Besides being an "expense" he is often
the "goat" for any accident that may occur which re-
duces the output of the factory. The power item being
large in the production of some articles, the engineer is
often held accountable for losses, and sometimes when he
is in no way responsible. Even when he is not charged
directly with the responsibility for losses, he is in-
formed that the loss in department so-and-so was due to a
drop in steam pressure or to a few minutes' interruption
of light or power service, and this in a tone which leaves
him with the impression that life is just one thing after
another.
In a factory making food products, where much steam
was used for cooking and drying, the foremen of the differ-
ent departments seemed prone to charge their short or
otherwise unsatisfactory outputs to a drop in steam pres-
sure. This so got on the nerves of the master mechanic
that he persuaded the manager to buy a recording pres-
sure-gage. This was fixed to the wall above the master me-
chanic's desk and connected to the steam main in the
boiler room, which was in the adjoining building.
A few days later the manager sent for the master me-
chanic and informed him that the output of Mr. Jones'
department had been seriously reduced the night before
on account of a great drop in the steam pressure. The
master mechanic produced the chart taken from the gage
at ; o'clock that morning and showed that during the
previous 24 hr. there had been no abnormal variation in
the pressure and that the statement of Mr. Jones was
just a plain lie. The manager must have had a heart-to-
heart talk with Mr. Jones, because late in the afternoon
Jones called on the master mechanic and had quite a
lengthy but friendly chat. No reference was made to steam
pressures, but Jones kept his eyes on the pressure gage
throughout the conversation. As he was about to leave he
pointed to the gage and asked, "What is that thing there ':"
"That:" said the master mechanic; "0, that's a trap to
catch four-flushers."
C. 0. Sandstrom
Kansas City, Mo.
Under the above title, on page 11? of the Jan. 26 issue.
there is reference to a device patented by C. P. Hall, of
the Rookery Building, Chicago.
If my memory serves me rightly a coupling of this
construction was designed by William G. Bond, chief
engineer for the National Biscuit Co., Tenth Ave. and
Fifteenth St., New York City, some fifteen years ago.
and it may now be in service in that plant.
I was in charge of the electrical equipment and assisted
Mr. Bond in the preparation of the working drawings of a
coupling that I am almost positive was similar in every
way to the detail you have shown.
Newton L. Schloss.
New York City.
m
<GriP®tuittiiimg| ■aasadles* Heav^'
Mgiclhinira©2=5^
I have seen engine erectors use neat cement for grout-
ing under engines. This, I believe, makes a grouting in-
ferior to a mixture of one part cement and one part clean
sand, or even two of sand to one of cement. While neat
cement gets very hard, it cracks easily.
It is a matter of considerable discussion whether, in
setting engines, the leveling wedges should be left in or
taken out after the grouting has set. With the wedges in.
almost the entire weight of the engine remains on them,
as the grouting will not set up tight enough to take the
weight and the engine is much more apt to work loose
on its foundation.
I once had a three-cylinder vertical, direct-connected
engine that worked badly. The engine was raised a quar-
ter of an inch, the old grouting knocked out and some
four hundred pounds of sulphur run under the base. Sul-
phur was used because the foundation had become so oil-
soaked that it would have been impossible to get a cement
grouting to bond. That job was done more than four
years ago and the engine does not show the slightest
movement.
In doing this work it was found that a wedge had been
left under each side of the base at about the center of the
engine. Tl' these wedges had been pulled out in the first
place, the engine would never have started working as it
did ; it was simply rocking on the wedges.
D. N. McClinton.
Pittsburgh. Penn.
.March 2, L915
POW E II
311
llllillllllllllllllllllllllllllilllllllllllllliliiliiniiliiliinni iiitiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiillliiillliliiiiiilliliiiiiiiiiiiu Iiiiiiiiinn IIIIIIIIIUIIII Illllll II II Illllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll Illllllllilllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
■ (.-mi li im- of Boiler Tubes — When a return-tubular boiler
een in continuous use for five years, the tubes having"
been i erolled a number of times, is it possibli to eul "ff the
■ Is by further rerollings?
F. C. T.
If the boiler tubes are rerolled in such a manner that they
are each time expanded inside of the tube sheet, then a suffi-
cient number of rerollings will cause the tube ends to split
or to break off, especially if the tube material has I >m<
weakened by corrosion.
Breakage of Shafts in Hubs of Pulleys- What reason is
to be assigned for repeated breakage of our shafting inside
of the hubs of driving and receiving pulleys?
J. O. B.
The shafts break in th. hubs of the pulleys because those
are the points where, mainly from tension of belts, the shafts
axe subjected to greatest bending stresses. The remedy is to
reduce the bending stresses by placing bearings closer to the
pulleys or using larger pulleys, thereby transmitting the
same power with less belt tension and also less journal fric-
tion.
Relative Water I seil by Refrigerating Systems — Is there
any difference in the quantities of water required by absorp-
tion and by compression systems of refrigeration of like
capacity -'
G. B.
It is customary to use a little more water for absorption
ms than for compression systems having simple steam
engines. When compound condensing engines are used for
driving compressors the water used to obtain 2*1 in. vacuum
is about the same as required for a standard absorption sys-
tem of equal refrigerating capacity.
Latent Heat of Fusion anil of Evaporation — How many
B.t.u. must be added to 1 lb. of ice at 32 deg. P. to melt it to
water at the same temperature: and how many B.t.u. must
be added to 1 lb. of water at 212 to convert it into steam at
atmospheric pressure?
F. A.
The heat required to melt a pound of ice at 32 deg. to
water at the same temperature is 144 B.t.u., this being the
latent heat of fusion of ice. Conversion of a pound of water
at 212 deg. F. into dry saturated steam at atmospheric pres-
sure, requires the addition of 970.4 B.t.u.. called the latent
heat of evaporation at atmospheric pressure, one B.t.u. being
taken as Civ, of the heat required to raise a pound of water
from 32 to 212 deg. F.
Conversion of Gage Readings into Absolute Pressu
With a barometric reading of 29.4 in. what would be tie ab-
solute pressures corresponding to 100-lb. gag. pressure and
26-in. vacuum?
C. R.
Assuming that the barometric and vacuum gage readings
are, as usual, based upon heights of mercury columns at a
temperature of 62 deg. F.. at which temperature an inch of
mercury column is equivalent to 0.491 lb. per sq.in., then for
a barometric reading of 29.4 in. a gage pressure of 1"" lb
would correspond to
100 -)- (29.4 X 0.491) = 114.435 lb. per sq.in. absoluti
and 26-in. vacuum would correspond to
(29.4 — 26) X 0.491 = 1.669 lb. per sq.in. absolute.
Temperature of steam at Reduced I'renKiire — If dry satu-
rated steam at S5-lb. gage pressure is passed through
ducing valve what will be its temperature if reduced to 4-lb.
gage pressure?
Q. W. D.
My referring to Marks and Davis' steam tables it may be
Been that each pound of dry saturated steam at 85-lb gage
pressure, or 85 + 15 = 100 lb. absolute, contains 1186.3 B.t.u.
above 32 deg. F. Neglecting the heat lost by radiation and
in work overcoming friction in passing through the reducing
valve, which under ordinary circumstances would be negligi-
ble, each pound of the steam at the reduced pressure of 4 lb.
gage, or 4 + 15 = 19 lb. absolute, may be regarded as con-
taining the same number of heat units as in the original con-
dition, viz.. 1186.3 B.t.u. above 32 deg. F. Referring to the
same tables of heat of steam at various pressure and with
different degrees of superheating, it is found that the tem-
perature of dry saturated steam at 19 lb. absolute, when sat-
urated, contains only 1155.2 B.t.u. per pound above 32 deg. F..
and the temperature is 225.2 dog. F.. but when superheated
60 deg. F. each pound contains 11S3.6 B.t.u., and when super-
heated 70 deg. F. each pound contains 11SS.3 B.t.u. The degree
of superheat corresponding to 11S6.3 B.t.u. is therefore found
by interpolation to be
60 +ril8L3_ZL.1183JS
LllSS 3 - 1 183 6
(To
60) I = li."> 7 deg. F
md the actual temperature would be
225.2 + 65.7. or about 29] deg. F
Efficiency of Boiler and Crates — What would be the effi-
ciency of a boiler and grate if the evaporation of 37.968 lb. of
water from feed water at 170 deg. F. into dry saturated steam
at Hi) lb. per sq.in. gage pressure required the combustion
of four tons of coal of a calorific value of 13,000 B.t.u. per lb.?
V. K. S.
Each pound of feed water at 17u deg. F. would contain
170 — 32 = 13S B.t.u. above 32 deg. F.
and as a pound of dry saturated steam at 110-lb. gage pres-
sure, or about 125 lb. per sq.in. absolute, contains 1190.3
B.t.u.. then each pound of water evaporated into steam would
require
1190.3 — 138 - 1052.3 B.t.u.
so that under the conditions stated the evaporation of 37,!>i;s
lb. of feed water would require
37.96S X 1052.3 = 39.953,726.4 B.t.u.
Allowing 2000 lb. per ton, then in using four tons of coal the
heat absorbed per pound of coal would be
39,953.726.4
= 4994.2 B.t.u.
4 X 2000
As the efficiency of the boiler and grate would be equal to
Heat absorbed per pound of coal
lue of 1 lb. of coal
Piston Speed Assumed ia Pump Formula — What pump pis-
ton speed would have to be assumed for figuring pump ca-
pacity by the formula. Gallons pumped per minute = d2 X 4.
in which d represents the diameter of water piston in inches?
K. H.
ing for slippage or reduction of piston area
d. the delivery would be expressed by the
Without allov
by the piston f.
— formula:
(1) Gallons per niin.
d2 X 0.7854 X L X n
231
iiiich
d = Diameter of water piston in inches:
L, = Length of stroke in inches;
n — Number of single strokes per minute:
231 Number of cubic inches per gallon.
Callings Piston speed in feet per min., then as
L
X n or II
L X n,
formula * 1 ) r
(2) Gallons
Therefor
ig-ht be written
d2X 0.7S54 X 12 S
per min. = -
d2X 0.0408 XS
.■hen
231
the given formula would be true -when
d2X 4 = d2X 0.040S X S,
S = 9S.04: or, in other words, the given formula
would be correct for an assumed piston speed of 98.04 ft.
per min. without any allowance for slippage or piston rod,
which would be equivalent to assuming a piston speed of 100
ft, per min., with an allowance of
(100 — 98.04) X 100
- 1.96 per cent.
100
reduction of capacity by slippage and piston rod.
[Correspondents sending us inquiries should sign theii
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
312
P (") W E H
Vol. 41, No. 9
>ct of Vac^a^iiinm inn Stteamm
Nmrlbiinies*
By G. Gerald Stoney
SYNOPSIS- An interesting article dealing with
the thermal gains anil losses due to vacuum in
lane! and marine turbines.
The degree of vacuum which gives the same velocity ratio
at the exhaust end as throughout the whole turbine is the
Vacuum under which the best results are obtained: conse-
quently, a turbine designed for 29 in. vacuum, barometer
30 in., requires more rows of blades or wheels than one
designed for 27 in., the number of rows or wheels of a
given diameter in each case being proportionate to the B.t.u.
available in the range between the initial and final pressures
and temperatures through which the turbine works. There
may be considerable latitude in the velocity ratio at the
exhaust end without seriously affecting the available economy.
Neglecting the effect of the reheat factor, which is small in
modern high efficiency turbines, and also neglecting terminal
losses, with 175 lb. absolute initial pressure and a superheat
of 150 degrees, the gains per inch of vacuum in the B.t.u.
Bt.u Available
M
^
\
4^
%
^
t*
1
X^
■^
^5
&**
3
«£<gfc
t
<s*v
5^Tj
?£vo*f
1 s
ins
Per Cent Gams per Inch of Vacuum
Fig. 1. Distribution of Heat during Adiabatic Expansion ; Initial
Pressure 175 Lb. Absolute; 150 Deg. F. Superheat
available during1 adiabatic
and are:
expansion are as shown in Fi
Between 23 in. and
on about 300 B.t
Between 24
Between 25
Between 26
Between 27
Between 28
Between 2S*£
TABLE
3 per cent, or an increase of 9 B.t.u.
t 11
.t.u
.tu.
t.u
.t .11
.t.u
and 25
and 26
and 27
and 2S
and 28V>
and 28%
and 29
Between 29 in. and 29%
For saturated steam at 175
approximately the same.
In the case of an exhaust turbine working with, say 15 lb
absolute, the gains per inch of vacuum as shown in Fig. 2 are
TABLE 2
Between 23 in. and 24 in., 9 per cent, or an increase of 10 B.t.u
on about 110 B.t.u. available at 23 in.
~ u
available at
n., 3 per cent, or 10 B.I
n., 4 per cent, or 12
n., 5 per cent, or 15
n., 6 per cent, or 21
n., s per cent, or 29
n., 9 per cent, or 36 B.I
n., 11 per cent, or 42 B.I
n., 13 per cent.
absolute, the figures are
Between
24
n,
and
25
n.,
10
per
cent
or
11
Between
25
n.
and
26
n..
11
per
cent
or
13
Between
26
n.
and
n.,
12
per
cent
or
li
Between
n.
and
28
14
per
cent
or
Between
28
n.
and
28%
n.
17
per
cent
or
30
Between
:»':
n.
and
i>%
n.
20
per
cent
or
38
Between
28%
n.
. 1 1 1 i 1
29
n.
23
per
cent
or
In
Between
29
n.
and
29%
n.
27
per
cent
or
b'l
•From a paper read before the Institution of Mechanical
Engineers, England.
For each degree Fahrenheit that the temperature due to
the vacuum is reduced, there are approximately 1.5 more
B.t.u. available, and this is approximately the case through
the whole range considered in tables 1 and 2 and Figs. 1
and 2. These gains due to vacuum are attainable when the
turbine can be suitably designed, but, in the case of high-
speed, large output land turbines, allowance must be made
for increased terminal losses.
For example, in a 3000-kw. land turbine at 3000 r.p.m.
with an initial pressure of 175 lb., 150 degrees F. superheat
and a vacuum of 29 in., the consumption will be about 12 lb.
per kw.-hr., and the steam per hour will be 36,000 lb. or 10 lb.
per second. The volume at exhaust, allowing for condensa-
tion, will be about 6000 cu.ft. per second. With present
materials available, it is not in general customary to go
above about 550 ft. per second for the mean velocity of the
blades at the exhaust end, giving a mean diameter of 42 in.,
and as the blade height cannot be more than one-fifth of
this, or S.4 in., the area of the annulus is 7.7 sq.ft. The
velocity of the steam leaving the blades through the re-
stricted area will then be 780 ft. per second and involve a
loss of 12 B.t.u., assuming that
the velocity ratio and angle of .
S K the blades are such that the
° steam leaves them axially, as it
should, to give the minimum
loss. Even under these condi-
tions there is still a gain of 6%
per cent, between 28 and 29 in.
vacuum. For still larger pow-
ers these effects become more
pronounced, until conditions are
eventually reached in this
class of turbine having a highly
restricted exhaust end when an
increase in vacuum causes no
gain. It is the aim of designers
to increase the limiting vacuum
by using higher blade speeds
and enabling an exhaust end of
larger dimensions to be em-
ployed. This is undoubtedly a
direction in which increased
efficiency in large power high-
speed turbines is to be found.
The effect of increased blade
speed is appreciable, as for a
given vacuum the reduction in
available gain varies inversely
as the fourth power of the
blade speed, since as the blade
height cannot well be more
than one-fifth of the mean
diameter of the blades, the area
at the exhaust will vary as the square of the diameter, or as
the square of the mean blade velocity. Therefore the longi-
tudinal velocity varies inversely as the square of the mean
blade velocity, or the B.t.u. lost, inversely as the fourth
power. Of course, the reduction can be halved by adopting
a turbine with double flow at the exhaust, but this often
introduces complications, although many economical land
turbines of large power have been designed on these lines.
Something can also be done by shaping the exhaust suitably,
so as gradually to reduce the velocity of the steam on
leaving the blades.
The case of reduced loads will now be considered. With
throttle governing, the initial steam-pressure is reduced in
accordance with a right-line law similar to the Willans law
for the steam consumption, and it may be taken that in this
case the initial pressure at no load is approximately atmos-
pheric. If at full load the initial pressure is 175 lb. absolute,
at half load it will be about 95 lb., and at quarter load, 63 lb.
At half load, with a vacuum of 2S to 2S«. in., the percentage
gains in consumption per inch of vacuum would be increased .
by about one per cent., and at quarter load by about two and
one-half per cent, above those given in tables 1 and 2, owing
to the reduced B.t.u. available by reason of the reduced
initial steam-pressure. The amounts of these gains will
depend on the velocity ratio throughout the turbine, which I
has been assumed to be constant at full load.
March 2, 1915
POWER
3] 3
At reduced loads with throttle governing, the velocity
atlo will be approximately the same as at full load through-
ut the turbine, except near the exhaust end, where it will
ie greater at reduced loads. This may either slightly in-
rease or diminish the efficiency at the exhaust end, according
s the general velocity ratio is high or low, but in general
he effect will be small.
With nozzle governing, the gains due to increased vacuum
t reduced loads are somewhat less than with throttle gov-
rning, and the amount depends on the type of nozzle
;overning used, but broadly, at full load and at reduced loads
he gains in consumption per inch of vacuum are more
learly equal with this type of governing. When a turbine
s not bladed so as to give the full velocity ratio up to the
xhaust end at full load, it is obvious that the above gains
to vacuum must be modified.
du
410
23 24 25 26 27 28 n 29
Vacuum Barometer 30"
70 80 90 100 110 120 130 140
Temperature of Vacuum, Deg Fahr
Fig. 2. Distribution of Heat during Adiabatic Ex-
pansion; Initial Pressure 15 Lb. Absolute;
Saturated
Direct-coupled marine turbines especially, from considera-
tions of weight and space, are often bladed to give uniform
velocity ratio at full speed with about 26 in. vacuum, and
from various causes many land turbines have been similarly
bladed. In turbines so bladed and with ordinary steam pres-
sures, it has been found by experience that the gain per
inch of vacuum at full load is as follows:
Between 26 in. and 27 in., 4 per cent, or 12 B.t.u.
Between 27 in. ana 2S in., 5 per cent, or 17 B.t.u.
Between 2S in. and 28% in., 6 per cent, or 22 B.t.u.
Between 28 V& in. and 29 in., 7 per cent, or 27 B.t.u.
In the turbines so bladed and at constant speed, as in land
work, the velocity ratio at the exhaust end would automat-
ically become at half load uniform with the rest of the
turbine at about 2S in., and for quarter load, at about 2.x :i4
in., so that in general it may be said that the theoretical
gains as given will be completely obtained at reduced loads,
but for strict accuracy, each case should be considered on
its merits. It may be noted here that, although there is a
decrease in efficiency at the exhaust end by having a cramped
exhaust and low velocity ratio, there is but little loss when
the exhaust end is large and has an unnecessarily high
velocity ratio.
Marine turbines running at reduced speeds when the load
is reduced may now be considered. Geared turbines can be
and should be bladed for high vacuum, and the blading should
be for nearly the highest vacuum obtainable in the waters
in which the ship trades, as there is but little loss by running
?. turbine bladed for high vacuum at a lower one. For
example, it should be bladed for 28% to 29 in., the vacuum
obtainable in home waters and the like, and not for 27 V4
to 28 in., which will be the vacuum obtainable in the tropics
with a good condensing plant. In such turbines the full
theoretical gain due to vacuum will be attained at full speed.
At half speed and one-eighth power, if the consumption at
full load is assumed to be 12 lb. per shaft horsepower, and
at half speed 16 lb., the steam at half speed will be one-sixth
that at full speed, and the velocity ratio three times that
at full speed for the same vacuum, so that the exhaust end
is amply large enough for the highest vacuum which can be
attained, and therefore the gain due to increased vacuum
will be somewhat more than that at full speed.
In most cases, blading a geared turbine for high vacuum
as compared with low vacuum adds little to the weight,
and generally only necessitates the exhaust end being made
somewhat larger. It is important that the exhaust between
the turbine blades and the condenser should be free and unre-
stricted, so that the loss of vacuum between the last row of
blades and the steam space in the condenser should be a
minimum. This applies to all classes of turbines.
It is equally important that the loss of vacuum between
the steam space in the condenser and the air-pump suction
should also be a minimum. In other words, given a condenser
and an air pump of the highest efficiency, the difference in
vacuum between the air-pump suction and exhaust end of
the turbine should be reduced to an absolute minimum. The
importance of this requirement should be carefully noted when
analyzing data obtained from any particular turbine installa-
tion, whether land or marine, as otherwise erroneous con-
clusions may be formed. For example, if any of the many
factors in design which influence the efficiency of any given
installation as a whole are not provided for, it is futile to
carry a vacuum higher than such provisions warrant: the
consequent sacrifice in economy is measured in such cases
by what is obtained and what is obtainable Sometimes
a definite velocity is fixed on for the velocity of the steUm
in the exhaust, but this has the difficulty that it depends on
the vacuum for which the condenser is designed. A better
way is to make the area of the exhaust have a definite ratio
to the area of the annulus of the last row of blades, and in
direct-coupled marine turbines this ratio is generally 1.5 to
1.7, but in geared turbines it can be increased to about 2.
30
E26
1"- 1 1 1 1 1
Vacuum due to 60 Fahr. \ .
| \, ,* PERnaawM™----
==
M
£=100,
w
f=45'
|»30"'
■g-zo*
$-*-
Fig. 3.
20 30 40 50 60 70 80 90
X= Ratio Circulating Water to Steam
Vacuums with Different Amounts of
Cooling Water
This means that, if the reduction of velocity can be made to
take place gradually as in a diverging orifice, most of the
terminal loss at the blades will be recovered, and much can
be done in this direction by careful attention to having grad-
ually diverging stream lines of steam from the blades to
the condenser. A rule sometimes used on land is to have
18 to 20 lb. of steam per hour per square inch of exhaust area,
and in many cases this works well. More careful attention
is required in the future as to the shape of the exhaust, for
at present many exhausts are so shaped as to cause consider-
able and unnecessary loss of vacuum.
3 1 4
IMiWER
Vol. 41, No. 9
The case of a direct-coupled marine turbine, only bladed
for 26 in. at full speed, is rather different. Here, at full
speed, the effect of vacuum will be as given on page 312, but
the cases of half speed and one-eighth power have to be
specially considered, more particularly on account of such
devices as cruising turbines, etc. If we assume the steam
per shaft horsepower with Parsons turbines to be 13 lb.
at full speed and 21 lb. at half speed, and that the shaft
horsepower at half speeds is one-eighth that at full speed,
the steam per hour will be one-fifth that at full speed.
Assuming that throughout the main turbines generally the
velocity ratio is 0.5 at full speed, then at half speed the
velocity ratio throughout the main turbines will be 0.25,
except at the exhaust end, where it will be 1.25. This means
that the full effect of vacuum will be obtained up to over
29 in., and on account of the low velocity ratio, the effect,
provided the condensing plant will respond, will considerably
exceed the theoretical at lower vacuums.
Up to the present the turbine alone has been considered,
but in a complete installation, whether land or marine, there
are many other factors to be taken account of. As increase
in vacuum is associated with a correspondingly lower tem-
perature of condensate, it follows that if the vacuum is raised
160
£26 -120
1 §
g 24 £ 100
20
Vacuum due to tt
Vacuum due to t?
\ 1^-— — ^ — z^-—~~ — *
X
y V
/
V j/
\ /
\y
^-^ i
T""-— — .
U
1 1
t,
300 400
Conducti
500
<ity K
Fig. 4. Vacuums axd Temperatures with Varying
Conductivity: Circulating 'Water (c>0 Dei;. P.)
60 Times Amount of Steam C'oxiiexsed
and the condensate is delivered to the boiler at the same
temperature at which it leaves the condenser, either the
quantity of steam generated in the boiler per unit of coal is
decreased or the quantity of coal per unit of steam generated
is increased. If the difference between the temperature due
to the vacuum and that of the condensate is taken as constant,
a reduction of 10 degrees in the temperature of the feed-water
delivered to the boiler is equivalent to an increase of about
one per cent, in coal consumption per unit of steam gen-
erated, or
Between 26 in. and 27 in. = 1 per cent.
Between 27 in. and 2S in. = 1% per cent.
Between 2S in. and 29 in. = 2 per cent.
Such a condition never arises in practice on land or at
sea, as the condensate is invariably heated either by the waste
gases from the boiler or by the exhaust steam from the
auxiliary engines, or by both. Land installations usually
include an economizer in the boiler uptake, and the practical
requirement in such a case is that, in order to prevent
sweating on the tubes, the feed water should be delivered to
the economizer at a temperature of about 120 degrees P.
But even at the highest vacuum there is usually sufficient
exhaust steam from the auxiliaries to raise the condensate
to this temperature, so that such a system represents the
highest economy attainable with any given plant.
Marine installations present a different problem by reason
of the large quantity of exhaust steam available from the
auxiliary engines, and it may be noted that the heat in
exhaust steam is used to the greatest advantage possible
when it is redelivered to the boiler with the feed water.
It follows that in order to attain maximum economy on
shipboard, all the exhaust from auxiliary engines should be
condensed by the feed water. A perfect installation from
this point of view would be one in which the turbine works
under the highest attainable vacuum with efficiency, and in
which the exhaust steam is maintained at such pressure as
will enable its heat to be wholly transferred to the feed
water. In fact, the economic pressure for the auxiliaries to
exhaust at is that in which the whole of their exhaust can
be condensed by the feed. Obviously there should be no
surplus exhaust, and if there is, it should never be discharged
into the main condenser, because of the highly prejudicial
effect of oil on the heat-transferring efficiency of the con-
denser tubes and on the vacuum. The direction in which
progress is to be made on marine turbine installations would,
therefore, appear to be, (a) high vacuum turbines; (b) high
efficiency condensing plant; (c) economical auxiliaries; (d)
efficient exhaust-steam feed-heaters.
In some cases where there is a surplus of auxiliary steam
it is turned into the low-pressure turbine, and here there is
an apparent partial recovery of the loss, but this arrangement
has the defect of fouling both the turbines and the con-
denser with oil and reducing their efficiency, so that the
power of the turbine may easily be reduced to a far greater
extent than it can be increased by the use of such surplus
steam. If, however, the steam is used in this way, it should
be carefully filtered.
In order to consider further the effect of vacuum on an
installation, it is necessary to consider the question of the
condensers and the power necessary to work them. In a
surface condenser there are three losses to be considered:
(a) the temperature rise in the circulating water; (b) the
resistance of the tube to heat transmission from the steam
to the water; (c) air insulation of the condensing tubes.
These may be summed up in the apparent conductivity
K of the condenser — that is, the B.t.u. transmitted per square
foot per hour per degree Fahrenheit difference of temperature
between the steam and the water.
Let
ti be the temperature in degrees Fahrenheit of the inlet
water to condenser.
ts be the temperature in degrees Fahrenheit of the water
leaving the condenser.
T be the temperature in degrees Fahrenheit due to the
vacuum.
X the ratio of circulating water to steam condensed.
S steam condensed per square foot of condenser surface
per hour.
■nience this is reckoned on the outside of the tubes.)
(For
Ther
As it takes i
each pound
K = 2.3 SX log T _ ^
ordinary practice about 1000 B.t.u. to condense
f steam we may write
1000 = X (tL. — t,)
the equation becomes
. 3 S X 1
As the maximum vacuum a condenser can produce is that
due to the temperature of the exit water, the object of the
designer is to have S as small as possible. With a condenser
in average conditions of cleanliness and efficient air with-
drawal, the value of the conductivity K is obviously much
higher than with inferior air extraction or a dirty condenser.
The conductivity is also influenced by the load. For example,
in a heavily loaded condenser, under the best conditions, a
value of K of 1500 or even higher has been reached, while
in condensers under low load it may be no higher than 300,
so that this method of comparison requires to be used with
some discretion.
Fig. 3 shows the vacuums obtainable with various values of
K, S and X, and Figs. 4 and 5 the effect of conductivity at
various rates of condensation for X = 60 and X = 30. All
these are for an inlet temperature of 60 deg. F. and similar
curves can be plotted for any other temperature, but as they
are all similar in character, those for 60 deg. F. are alone
given. It will be observed from Figs. 4 and 5 that the effect
of reduced conductivity, such as is caused by air, is much
more at high rates of condensation than at low, showing that
the effect of a faulty air pump or dirty condenser is much
more when the rate of condensation is high. It will also
be seen that, approximately, the loss of vacuum below that
theoretically obtainable depends only on the" rate of condensa-
tion and on the amount of air insulation, and not on the
quantity of circulating water — that is, that 5 is approximately
independent of X, always assuming a condenser free from oil
on the outside of the tubes and scale on the inside. From
the curves it follows that there is not much use in bavins
more circulation water than about sixty to eighty times the
March '.'. L'915
P ( ) W E R
315
steam condensed at full load in home waters and the tropics
respectively.
Figs. 4 and 5 also show the importance of having ample
surface, and confirm what has often been found, that money
put into a condenser of ample size is money well spent.
Ample surface also gives a good margin to allow of the
condenser getting dirty or for overloads. With a high rate
of condensation, especially if the condenser is dirty, when
an overload is required the vacuum will drop so much that
not only is there often difficulty in getting the overload out
of the turbine, but the boilers are still further overtaxed due
to increased steam consumption causing the steam pressure
to drop just at the time it is most important to have full
pressure. It is usual in modern power stations to have a
vacuum of about 20.1 in., barometer 30 in., with GO deg. P.
cooling water and circulating water >>G times the steam
condensed, and 28 in. with SO deg., 70 times, and it seems
as if these conditions cannot be much improved upon, as, if
the circulating water were increased in this case from 6G to
100 times the steam, the improvement in vacuum would only
be about % in., and the pumps and circulating pipes would
have to be increased 50 per cent. With 65 times as much
anil a moderate rate of condensation, such as 6 to 8 lb. per
square foot at normal load, there is an ample margin for
overload, an overload of 50 per cent, only reducing the
vacuum by about half an inch.
In cases where there is not a supply of natural cooling
water or only a restricted supply, or where cooling towers
are used, the question of the best vacuum must be most
carefully considered, and so many factors come into the
case that each problem must be considered on its merits and
alternative schemes worked out to find which is best. Such
cases it is not proposed to deal with in this paper.
In the mercantile marine, the only question that has to
be considered is the case of full speed at sea, and everything
has to be arranged for the highest economy at that speed.
In a recent geared turbine meat-carrying ship, the turbine
is bladed for about 28 Vi to 2S% in. vacuum, and the con-
densers have a surface of 8 lb. per square foot or 1% sq.ft.
per shaft horsepower, or equivalent to, say, 1.35 per i.h.p.,
and circulating "water equal to 75 times the steam condensed,
so as to provide for tropical waters. The vacuum is 29.1 in.
with GO deg. F. sea temperature, 28. S in. with 60 deg. F.,
and 28 in. with 80 deg. F.
The weight of the Scotch boilers is 62 per cent., of the
main turbines 12 per cent., of the condensers 3 per cent., of
the circulating and air pumps with their pipes G per cent.,
and of other auxiliaries, pipes, etc.. IS per cent, of the total
"weight in engine and boiler rooms.
If the surface of the condensers were halved, giving 16
[b. per square foot, keeping the same circulating water, there
would be a loss of vacuum of about one-half inch, and a
saving on the total weight by the smaller condensers of 1 V>
per cent. This would increase the steam consumption by,
say, 5 per cent., and therefore the weight of the boilers, by
5 per cent., and the total weight by 1% per cent., not to
Bpeak of the 5 per cent, extra coal that would have to be
carried. A reduction in the circulating water would also tend
the same way. It is much more economical to save at the
low temperature or condenser end of the system than at
the high temperature or boiler end, and therefore to have as
high an efficiency in the condensing" plant as possible and
turbines made to suit. The increase of weight, in the
condensers and turbines is much more than counterbalanced
by the saving of weight in the boilers and coal to be carried.
High efficiency in the condensing plant means not only suffi-
cient surface and sufficient circulating "water, but also most
efficient ail' withdrawal, as, for example, by a steam jet.
The case of warships has also to be considered. In the
case of a battleship with direct-coupled turbines, the weight
of the water-tube boilers is 35 per cent., turbines 25 per cent.,
condensers 3 per cent., circulating and air pumps, etc., 4
per cent., and other auxiliaries, etc., 33 per cent, of the total
engine and boiler room weights. The condensers condense
at full power 18 lb. per square foot, and the circulating water
is 65 times the steam. This gives, with 60 deg. F. sea tem-
perature, a vacuum of 28% in. Direct-coupled warship
turbines are bladed for about 26 in. for reasons given before,
but with geared turbines bladed for higher vacuums, it is
evident that it would pay to reduce the boilers and increase
the condensers. At reduced speeds the condensers are lightly
loaded, and here, as explained before, the highest vacuums can
be taken advantage of by the turbines. With the lightly
loaded condensers, the loss of temperature and vacuum due
to the conductivity between the water and the steam through
the tubes becomes small, and the important point is efficient
air withdrawal.
At half speed or one-eighth power the condensers are only
loaded to about 4 lb. per square foot, and as the vacuum is
generally only about 28% in., this means a conductivity of
about 150 as against 600 to S00 B.t.u. at full load. But if
greater care were taken to install air-withdrawing apparatus
of the highest efficiency and ample capacity, such, for example,
as is obtainable with a steam-jet combination, this vacuum
could be raised to 28% or 29 in. with sea water at 60 deg. F.,
provided the condenser was of suitable design, thereby effect-
ing a gain of at least 3 per cent, on the coal consumption,
an amount which would far outweigh the comparatively slight
additional cost and weight of the apparatus. This gain is
independent of the drop of temperature of the condensate,
as at low powers there is always more exhaust steam available
than can be condensed by the feed "water. Other types of
warships can be similarly considered, but the case of the
destroyer is especially difficult, as it is essentially a com-
promise, and here it has been considered economical to load
up the condensers at full speed to about 27 lb. per square
foot and reduce the circulating water to about fifty times.
With the advent of geared turbines the case becomes
different, since they can be bladed for high vacua with little
increase in the weights and sizes of the turbines, and it is
clear that the greatest benefits from the highest vacua will
be found. It is to be expected that in such cases there will
be a large increase in the surface of the condensers and
30 160
§26 o|2Q
Vacuum due jo ti
Vacuum due to t2
\
\
/
t,
/
ti
22 80-
20 60
0 100 200 300 400 500 600 700 800
Conductivity K
Fig. o. Vacuums and Temperatures with Varying
Conductivity; Circulating Water (60 Dec.
F.) 30 Times Amount Steam Condensed
improvement in air withdrawal, with a consequent reduction
in the boilers and fuel carried.
The aims of an efficient condenser are to have the maxi-
mum of heat transfer from the steam to the circulating"
water — that is, a minimum difference between the tempera-
ture due to the vacuum and the temperature of the circulating
water leaving the condenser, and also to deliver the con-
densate to the hotwell as near the temperature due to the
vacuum as possible. And here it is important to consider the
steam consumption of the auxiliaries and the air-withdrawal
arrangements which comprise air pumps in some form, to-
gether with the withdrawal of the condensate from the
condenser. It is not proposed to enter into the different
types of air pumps, but as the driving power of these pumps
is at most only about one per cent, of the power of the
turbine at full load, and in general much less, the importance
of the steam used per unit of power required for driving
an air pump is negligible compared with its vacuum-produc-
ing qualities. The steam requited by the circulating pumps
depends on the steam consumption W in lb. per water
horsepower-hour, of the engine driving the circulating pumps,
the ratio X of the circulating water :o the steam condensed,
and the total head h in feet on the pumps. We have then
WXh
percentage of steam used by pump =
20,000
For example, if we take W = 60,
feet, we have percentage used = 3.6.
For X = 30, the percentage is 1.8.
X
60, and h — 20
316
POWER
Vol. 41, No. 9
The difference in the hotweil temperature, between con-
densers using these quantities of circulating water, is about
17 deg. F., so that without allowing for condensation it may
be said that in this case the temperature of the feed, after
it has condensed the steam from the circulating pump, is
largely independent of the quantity of circulating water,
and this has to be considered in making up the final balance
sheet, which alone enables the most difficult problem of the
best vacuum for any particular installation to be considered.
m
MadlwHtratteff" G©imveiraftH©sni ©if
The third midwinter convention of the American Institute
of Electrical Engineers was held at the Engineering Societies
Building, New York City, on Feb. 17 to 19. In his opening
address. President Paul M. Lincoln referred to the great
service of an engineering society in promoting exchange of
ideas, the idea usually being worthless unless passed along
to receive the benefit of other minds.
The application of electric motors was the topic of the
first session, D. B. Rushmore opening it with a paper on "The
Characteristics of Electric Motors." This paper, in the nature
of an outline, was followed by carefully prepared discus-
sions on different types of motors, each speaker selecting a
particular type.
On Wednesday afternoon five papers were presented: "Ef-
fect of Moisture in the Earth on Temperature of Underground
Cables." by S. E. Imlay; "Oil Circuit-Breakers," by K. C.
Randall; "Comparison of Calculated and Measured Corona
Loss Curves," by F. W. Peek, Jr.; and "A 100,000-Volt Port-
able Substation," by C. I. Burkholder and Nicholas Stahl.
Three papers comprised the Thursday morning program:
"Distortion of Alternating-Current Wave Form Caused by
Cyclic Variation in Resistance," by Frederick Bedell and E.
C. Mayer; "Dimmers for Tungsten Lamps," by A. E. Waller;
and "Searchlights," by C. S. McDowell.
The Friday morning session was devoted to "Electrical
Precipitation," three papers being presented, namely: "Theory
of the Removal of Suspended Matter from Fluids," by W. W.
Strong; "Theoretical and Experimental Considerations of
Electrical Precipitation." by A. F. Nesbit; and "Practical Ap-
plications of Electrical Precipitation," by Linn Bradley. The
last technical paper was on "Electrical Porcelain," by E. E. F.
Creighton.
STATUS OF THE ENGINEER
The most interesting feature of the convention program
was the discussion on Wednesday evening of the "Status of
the Engineer." The list of speakers showed that care had
been exercised to have the subject dealt with from several
angles. A, C. Humphreys, president of Stevens Institute,
and Prof. G. A. Swain, of Harvard, represented those respon-
sible for the training of engineers; E. W. Rice, Jr., president
of the General Electric Co., and E. M. Herr, president of the
Westinghouse Electric & Manufacturing Co., represented the
largest employers of engineers, and L. B. Stillwell, H. G.
Stott and J. J. Carty represented successful engineers now ac-
tively engaged in the profession.
Mr. Stillwell in opening the discussion predicted that if
the engineer wrould take a more active part in public affairs,
proper recognition would follow. To this end, however, more
liberal and less technical education is needed in the colleges.
He charged the national engineering societies with having
failed to raise the prestige of engineers, pointing out by way
of comparison what the Bar Association has done for the
legal profession. In this connection he suggested that the
engineering societies jointly formulate a code of ethics, which
should be enforced strictly, even to the point of expulsion
from membership for any violations of the rules. Further-
more, the societies should adopt a policy with regard to
license legislation and also advise on public questions such as
water-power development, etc.
Mr. Rice in taking up the discussion reviewed some of the
engineering achievements and their effects upon modern civi-
lization; yet engineers have practically no voice in running
the Government. In the present Congress there is only one
engineer out of a total of 43n members in the House and none
in the Senate, about 70 per cent, being lawyers. In view of
the number of public problems directly or indirectly related to
engineering, which are up for consideration it would seem
advisable that the representation include some who have had
engineering training. "This training." said Mr. Rice, "makes
a man search for facts and represents a blending of con-
servatism and radicalism."
E. M. Herr. speaking from the standpoint of the manu-
facturer, believed that mathematical training and analysis
tend to unfit a man to deal with the human element, and
attributed to this fact the failure of many engineers in suc-
cessfully handling men. He advised the application of the
"Golden Rule" as the best solution to this phase of the
problem.
Speaking from his experience as an educator, Doctor
Humphreys was of the opinion that boys now come to college
poorly prepared, because much of their time has been taken
up in the preparatory schools with irrelevant studies. He
believed that the engineer should receive a more liberal
education, but did not advocate a six-year course, adding:
"The sooner a man gets out of college after learning the
fundamentals, the sooner will he become a specialist." With
regard to present regulative tendencies of the government
through commissions, Doctor Humphreys seemed to think that
it was being carried too far, and often took the form of con-
trol rather than regulation. He especially lamented the ap-
parent disposition in some circles to regard business as dis-
honest, and expressed the belief that with engineers occupy-
ing a prominent part in the Government and on commissions,
this country would be brought back to a sane regulation of
its affairs.
Professor Swain endeavored to show why engineers as a
class are not recognized to the same extent as men in many
other professions. "Leadership," he said, "depends upon per-
sonal qualities, some inherent and others received by training,
and it is doubtful whether engineers think straighter than
lawyers or business men, or have greater breadth of view.
In fact, the engineer is apt to confine himself too closely to
technical subjects to the exclusion of outside affairs." As a
remedy for this condition, he suggested a broader curric-
ulum in the technical schools, with less details, which can
be learned later, and a better training in English and in
such liberal subjects as will promote personal qualities. The
speaker believed the remuneration in engineering to be fair
and comparable with the average in other professions, al-
though admitting that large fees were the exception rather
than the rule in engineering. The ability of doctors and
lawyers to command large fees was probably due to the char-
acter of their work appealing to the emotions, or in the case
of the architect to the vanity of the client; wThereas in the
case of the engineer his work is a cold business proposition
and its value is measured accordingly.
Mr. Stott seemed to think the present status of engineers
fairly satisfactory, although he believed that engineers in
the government service are often deprived of proper credit
by their superiors, who often have no technical training
whatever. He believed engineers should specialize and, in
doing so, should follow their own inclinations.
Mr. Carty spoke of the engineer as concerned with prob-
lems of organization, but warned against "scientific man-
agement" masquerading as engineering.
The entertainment included a trip to the new power house
of the United Electric Light & Power Co. on Thursday after-
noon and a dinner dance at the Hotel Astor that evening.
Probably the most successful and most enjoyable so far
was the fifth annual dinner of the New York Section of the
American Institute of Steam Boiler Inspectors, held at Rectors
in New York, Feb. 20. The attendance was large. 110, made
up of people interested directly or indirectly in the inspec-
tion of boilers. In the role of toastmaster Michael Fogarty
distinguished himself as usual. The speakers in addition to
the incoming, retiring and past officers of the Institute were:
Dr. D. S. Jacobus, of the Babcock & Wilcox Co., who rehearsed
something of the history of the American Society of Mechan-
ical Engineers' Proposed Boiler Code, with which he, as a mem-
ber of the advisory committee, was very familiar; Fred R.
Low. editor of "Power." and Herman Van Ormer and John H.
Gleason. both of the Boston office of the Hartford Steam
Boiler Inspection & Insurance Co., and Inspector Lanigan
of the New York boiler squad.
Shrinknsre Dnrinjr Solidification — A few exceptions to
those substances which undergo the usual shrinkage during
the process of solification are pointed out by the "Mechan-
ical World." These exceptions include cast iron, antimony
and bismuth. When melted cast iron is poured into a mold
it expands in solidifying and presses into every part of the
mold. The pattern in the casting is, therefore, as clearly
traced as it was in the mold. After it has changed from
a liquid to a solid, however, the order is reversed, and in
cooling down from the first stage of solidification to normal
temperature a shrinkage of about % in. to the foot takes
place.
A clear-cut cast cannot be obtained from lead, which
is one of the reasons why antimony is made a constituent
of type metal. Gold coins have to be stamped; they cannot
be cast so as to produce a clear-cut design, for the same reason.
March 2, 1915
POWER
31 ;
eimiir&g* of tllhe E,xtp©§iiM©ini
At noon, Pacific Coast time (3 p.m. Eastern time), Saturday,
Feb. 20, President Wilson pressed a button in Washington
giving an electric signal for the opening of the Panama-
Pacific International Exposition in San Francisco. In last
s issue a number of the features of the Fair were given
as most likely to interest "Power" readers, and more is yet
to be printed of certain of the exhibits and the lessons to be
drawn from them with respect to past, present and future.
As the day of opening dawned, the city which had been
looking forward to it so long seemed fairly to break out with
its pent-up enthusiasm. For an hour from 6:30 o'clock, all
means of noise-making seemed to be in commission, from
steam whistles, automobile horns, car gongs and church bells
down to rattles, tin horns and the usual facilities available to
the individual. A large crowd had gathered on the grounds
hours before the opening, and before the end of the day the
attendance had broken all records of like kind, exceeding
300,000, in spite of the clouds and showers.
The dedicatory ceremonies were short and simple. The
citizens, headed by Governor Hiram W. Johnson and Mayor
Rolph, representing the state and city, were welcomed to the
grounds by the officers and directors of the Exposition and
officers of the Federal Government. Addresses "were delivered
by President C. C. Moore of the exposition, Dr. Frederick J. V.
Skiff, director-in-chief; Governor Johnson, Secretary of the
Interior Frank K. Lane representing President Wilson, and a
few others. Invocations and benedictions were pronounced
by clergymen representing the Roman Catholic, Protestant
and Jewish faiths. President Wilson forwarded a message
of congratulation to the directors, which was read to the
crowd.
At the Washington end the ceremony was staged in the
East Room of the White House, where places were reserved
for members of the Cabinet and the California delegation in
Congress. Assistant Secretary of the Navy Roosevelt repre-
sented the Government Exposition Board. At the President's
touch, two signals were sent, one by telegraph to San Fran-
cisco and one by wireless to Tuckerton, N. J., and relayed
thence to San Francisco.
With the receipt of the signal the Fountain of Energy was
started, flags of all the nations were raised on the various
poles and pinnacles, signal bombs were exploded from towers,
an aeroplane circled the Tower of Jewels, scattering doves of
peace, and the doors of the Palace of Machinery swung open,
revealing the exhibits within in motion.
James Smieton, Jr., who has been acting in that capacitj
for the past year, has been appointed secretary-treasurer
of the Society for Electrical Development.
N. H. Brown, until recently Chicago representative of
the Bury Compressor Co., has been made sales engineer of
the Erie Pump & Equipment Co., Erie, Penn., successor to
the Northern Equipment Co. and the Erie Pump & Engine
Works.
John S. Huey, formerly with the Allis-Chalmers Manufac-
turing Co., and more recently with Woodward, Wight & Co.,
has been appointed by the Kerr Turbine Co., Wellsville, N. Y ,
as its district sales agent for Louisiana and southern Missis-
sippi. His office is in Room 41S, Hibernia Bank Bldg., New
Orleans, La.
Matthew T. Slattery, an Ohio state boiler inspector in
general charge of the district which includes Cleveland, has
been appointed commissioner of the Cleveland smoke pre-
vention division to succeed E. P. Roberts, whose resignation
was recently noted.
William M. Davis, an occasional contributor to "Power,"
has accepted a position as efficiency engineer for the Texas
Co. He will have a force of a dozen or more in service,
who under his direction will be trained to make surveys and
inspections of customers' plants and prepare reports show-
ing how to obtain the best service with the lubricants in use.
John W. Exler has been elected president of the James
Lappan Manufacturing Co., of Pittsburgh, Penn. Mr. Exler
has been employed as a boiler maker and iron worker for
over 40 years. In the '80s he was engaged as foreman with
i'he Niles (Ohio) Boiler Co., and later with Reeves Bros. Co.,
at Alliance, Ohio. He has also filled some important posi-
tions with large Pittsburgh manufacturing concerns.
A. S. Baldwin has resigned as manager of the Best Manu-
facturing Co., to take effect not later than Apr. 1. This
company has recently been absorbed by the Kennedy-Stroh
Corporation, which has its complete organization. Mr. Bald-
win was for two years superintendent of the American £
British Manufacturing Co., Bridgeport, Conn.; four and one-
half years general superintendent of the Driggs-Seabury
Ordnance Corporation, Sharon, Penn., and for three years
general manager of the Alberger Pump & Condenser Co.,
Newburgh, N. Y. For the present his address is General
Delivery, Oakmont, Penn.
Erasmus Darwin Leavitt, of Cambridge, Mass., has been
elected an honorary member of the American Society of Me-
chanical Engineers, of which he was the second president.
Mr. Leavitt was assistant engineer in the United States Navy
from 1861 to 1867, consulting engineer for the Calumet &
Hecla Mining Co. from 1874 to 1904, and has acted as consult-
ing engineer in many large capacities. He is a member of
all of the professional engineering societies, and was awarded
the degree of Doctor of Engineering by Stevens Institute of
Technology in 1884.
Technical Associations' Secretaries — Technical societies
and associations have become so numerous and important
that a society of Technical Associations' Secretaries has been
organized, and held its first annual meeting in the rooms of
the American Society of Mechanical Engineers, Engineering
Societies Building, 29 West 39th St., New York, on Saturdav,
Feb. 27.
Transaction.* of the International Engineering Congress
(to be held Sept. 20-25, at San Francisco, Calif.) — Volume I
will comprise a unique series of papers on the engineering
of the Panama Canal. The various topics and subdivisions
of the work have been arranged by Col. G. W. Goethals,
chief engineer of the canal, and now governor of the Canal
Zone. Col. Goethals has also selected the author for the
treatment of each paper, and he will himself contribute the
introductory chapter. The various authors are, in general,
the officers who were in direct charge of the actual work
of construction, and the collection of papers thus becomes
a first-hand account of the engineering of the canal, writ-
ten by the men who were in immediate and responsible
charge of the undertaking. There will be 24 papers in all,
profusely illustrated, 22 of which deal with actual construc-
tive and engineering problems connected with the work, one
with the preliminary work in municipal engineering in the
Canal Zone, and one with the commercial and trade aspects
of the canal. This volume can be obtained only through
enrollment in the congress. The transactions of the con-
gress as a whole will include from seven to nine other vol-
umes, covering all important phases of engineering work.
Membership in the congress, with the privilege of purchasing
any or all of the volumes of the proceedings, is open to all
interested in engineering work. Full particulars can be had
upon application to W. A. Cattell, secretary, 417 Foxcroft
Building, San Francisco. Calif.
HOW TO RUN AND INSTALL A GASOLINE ENGINE. By C.
Von Culin. Published by Norman W. Henley Publishing
Co., 132 Nassau St., New York City, 1915. Revised Edi-
tion. Size. 3^4x6 in.; 96 pages, illustrated. Price, 25c.
This little book is printed as a pocket instructor for the
beginner or the busy man who uses a marine engine for
pleasure and who does not have the time or the inclination
for a complete technical perusal of the subject. The method
of treating the various topics by the author is such that a
man who has no technical knowledge of a gasoline engine-
may obtain enough information to enable him to operate one
successfully, either of the two- or four-stroke-cycle type.
Many pointers are given regarding the causes of trouble in
gasoline engines, and the remedies. If the reader absorbs all
the information contained in the book he should be able to
operate his gasoline engine without any particular trouble.
The book is well illustrated and contains a remarkable
amount of information for such a small volume.
HAND FIRING SOFT COAL UNDER POWER-PLANT BOILERS
is the title of Technical Paper SO, by Henry Kreisinger
issued by the U. S. Bureau of Mines, as an aid to firemen'
throughout the United States. Copies mav be obtained
without cost by addressing the Director of the Bureau of
Mines, Washington, D. C.
The paper, which contains descriptions of methods of firing
318
P 0 W E R
Vol. 41, No. 9
soft coal under power-plant boilers and of handling; fires so
as to have the least smoke and to set the most heat from
the fuel, seeks to meet the needs of the men, many without
technical education, who are employed in small plants. For
this reason the language used is plain and simple, and tech-
nical terms have been avoided as far as possible.
Under "General Directions on Firing Soft Coal," the follow-
ing statements are made:
When burning bituminous coal under power-plant boilers
the best results are obtained if the fires are kept level and
rather thin. The best thickness of the fires is four to ten
inches, depending on the character of the coal and the
strength of draft. The coal should be fired in small quantities
and at short intervals. The fuel bed should be kept level
and in good condition by spreading the fresh coal only over
the thin places where the coal tends to burn away and leave
the grate bare.
Leveling or disturbing the fuel bed in any way should be
avoided as much as possible; it means more work for the
fireman and is apt to cause the formation of troublesome
clinker. Furthermore, while the fireman is leveling the fires
a large excess of air enters the furnace, and this excess of
air impairs the efficiency.
The ashpit door should be kept open. A large accumula-
tion of refuse in the ashpit should be avoided, as it may
cause an uneven distribution of air under the grate. When-
ever a coal shows a tendency to clinker, water should be kept
in the ashpit. All regulation of draft should be done with
the damper and not with the ashpit doors.
In firing, the fireman should place the coal on the thin
spots of the fuel bed. Thin and thick spots will occur even
with the most careful firing, because the coal never burns
at a uniform rate over the entire grate area. In places where
the air flows freely through the fuel bed the coal burns faster
than in places where the flow of air is less. The cause of
this variation in the flow of air through the different parts
of the fuel bed may be differences in the size of the coal,
accumulations of clinker, or the fusing of the coal to a hard
crust. Where the coal burns rapidly, the thin places form.
Before throwing the fresh coal into the furnace the fireman
should take a quick look at the fuel bed and note the thin
spots. In a well-kept fire these spots can be usually recog-
nized by the bright hot flame. The thick places have either
a sluggish smoky flame or none at all. In order to place
the coal over the thin places the fireman should take a rather
small quantity of coal on his scoop, for it is much easier to
place the coal where it is needed with small shovelfuls than
with large ones.
The coal should be placed on the thin places in rather thin
layers. If the fireman attempts to fill up the deep hollows
in the fuel bed at one firing, the freshly fired coal may fuse
into a hard crust, thus choking the flow of air, causing the
fuel to burn slowly and starting new high places. If the
high places in the fuel bed are missed on one or two firings
the hard crust at the surface will gradually burn through
or crack, thus allowing more air to flow through, and the
place will get back to its normal condition. Of course, if the
high place in the fuel bed is caused by clinker the flow of
air will not be free until the clinker is removed with the fire
tool. Whatever may be the cause of the high places in the
fuel bed, the fireman should remember that they are places
where the coal does not burn. There is no use in putting coal
on such a place.
If the firings are too far apart the coal in the thin spots
may burn out entirely, allowing a large excess of air to enter
the furnace in streams. If those streams of air are not
properly mixed with the gases from the coal, only a small
percentage of the air is used for combustion, and most of it
passes out of the furnace, depriving the boiler of considerable
heat. If, for instance, air enters the furnace at atmospheric
temperature, say 75 deg. F., and leaves the boiler at about
575 deg. F., it carries away the heat that was absorbed in
raising its temperature 500 deg. F. This heat is lost to the
boiler. Another loss of heat occurs when holes form in the
fuel bed, because pieces of unburned coal fall through the
grate when the fireman attempts to cover the holes with
fresh coal. Therefore, in order to avoid the formation of
holes, firings should be made at short intervals, particularly
if, for any reason, the fuel bed must be kept thin.
NEW PUBLICATIONS OF THE BUREAU t >F MINES
Fourth Annual Report of the director of the Bureau of
Mines to the Secretary of the Interior, for the fiscal vear
ended June 30, 1914; 101 pages.
Bulletin S4, Metallurgical Smoke. By Charles H. Fulton;
92 pages; 6 plates; 14 figures.
Bulletin S5, Analyses of Mine and Car Samples of Coal
Collected in the Fiscal Years 1911 to 1913. By A. C. Fieldner,
H. I. Smith, A. H. Fay and Samuel Sanford; 44 pages; 2 fig-
ures.
Technical Paper SO, Hand-firing Soft Coal under Power-
Plant Boilers. By Henry Kreisinger; S3 pages; 32 figures.
Miners- Circular 21, 'What a Miner Can Do to Prevent Ex-
plosions of Gas and of Coal Dust. By G. S. Rice; 24 pages.
Publications should be ordered by number and title.
Applications should be addressed to the Director of the
Bureau of Mines, Washington, D. C.
X
A Simple Test for Animal and Vegetable Contents in oil
is to shake up with the sample in a test tube about one-fifth
or one-quarter of its own volume of a saturated solution of
borax in water. The presence of animal or vegetable matter
is indicated by an opaque white line of saponification, which
forms between the water and the oil after they are allowed
to separate. Paraffin in oil may be detected by heating a
sample up to 450 deg. The presence of paraffin is indicated
by a material darkening in the color of the oil.
TIRADE CATAILOQS
Chain Belt Co., Milwaukee, Wis. General Catalog No. 56.
Elevating, conveying and concrete machinery. Illustrated,
304 pp., 6x9 in.
Jeffrey Mfg. Co., Columbus, O. Bulletin No. 147. Swing
hammer pulverizers for coal, etc. Illustrated, 48 pp. Bulletin
No. 167. Belt conveyors. Illustrated, 24 pp.
Wm. B. Scaife & Sons Co., 221 First Ave., Pittsburgh, Penn.
Pamphlet. "Pure Clear Ice." Illustrated, 12 pp., 5xs in.
Pamphlet. Central Power Station Economy. Illustrated, 8
pp., 4x9 in.
The Compressed Gas Manufacturers' Association, In-
corporated, requests manufacturers of valves, cylinders, re-
cording gages, filling and weighing stands and of material
and appliances which enter into the manufacture, transpor-
tation and sale of compressed gases to send catalogs, price
lists and full descriptive details to the secretary of the as-
sociation. 2r> Madison Ave.. New York City.
BUSHHESS ITEMS
The Kerr Turbine Co., Wellsville, N. Y., has appointed W.
E. Storey, as its Toronto, Canada, representative, with offices
in the Kent Building. Mr. Storey was formerly identified with
the Underfeed Stoker Co., and more recently with Goulds
Manufacturing Co.
The Nelson Valve Co., of Chestnut Hill, Philadelphia, has
issued a revised edition of its twelve page folder entitled
"Double Disc vs. Solid Wedge." It contains an interesting
history of the development of the gate valve. Copies will be
mailed on request.
A very attractive circular has just been issued by the
Homestead Valve Mfg. Co., Pittsburgh, Penn., illustrating
many styles of Homestead Valves. "Here is Your Opportunity
to End Your Valve Troubles" is the title. It is being sent
to steam users everywhere.
The Yarnall-Waring Co., of Chestnut Hill, Philadelphia,
has recently secured an order for "Lea" V-notch meters from
the Philadelphia Electric Co., for its great new Christian
St. power house, for what is believed to be the largest feed-
water V-notch metering installation in the world, comprising
two ^00,000-lb. per hr. "Lea" V-notch recording meters com-
bined with two 20,000-hp. Webster feed-water heaters and
purifiers, to heat and measure 20,000 boiler hp. of feed water.
Make-up water for this plant will be measured by a 175,000-
lt). per hr. "Lea" V-notch recording meter.
3 advance
nt Agencies (Labo-
a- __
Work). Miscellaneous i Educational— Books), For Sale, 5 cents a word. mini
mum charge, si. 00 an insertion.
Count three words for keyed address care of New York: four for Chicago
Abbreviated words or symbols count as full words.
Copy should reach us not later than Hi A.M. Tuesday for ensuing week's Issue
nswers addressed
144 Mnnadnock
| similar literature).
Xo information given by us regarding keyed adv
Original letters of recommendation or other papers of value should not be in-
FOSDTHOHS OFEH
SALESMAN* wanted, one who sells to wholesale plumber
and hardware suppliers, to sell machinery cotton waste. P.
439. Power.
DESIGNER, thoroughly capable of laying out a complete
line of evaporators. Reply, stating age. experience, salary
expected, references, etc., P. 43S, Power.
DESIGNER AND CHECKER, with experience on condens-
ers and their auxiliaries; only first-class men need apply;
state age, experience and salary expected. P. 437, Power.
HIGH-CLASS CHIEF ENGINEER, for modern, medium-
sized packing house in Middle West; must have experience
and thorough knowledge of boilers, refrigeration, electricity
and packing-house machinery. P. 442, Power, Chicago.
P0SHTH0HS WAMTE1
ENGINEER (marine and stationary certificates), familiar
with boilers all types, reciprocating engines, turbines and
usual electric and refrigerating equipment; experienced and
competent as chief; New York City or vicinity. P. W. 4 4 4.
Power.
POWER
Vol. ll
\K\V YORK, MARCH 9, 1915
Xo. in
The Boiler Inspector
Confesses
The old boiler inspector looked at me over his glasses
with all the seriousness of a strong man approaching the
eonfessional. He WAS going to confess.
££ "TW 770, SIR. 1 ae\
^<W But as a y<
yi 1 knew wer<
never made half-way inspections,
pung man I passed conditions
rere no! real bad, but bad enough
to warrant giving attention. If a boiler
nit down at such a time, it meant delay. The
gng er or the superintendent complained and every-
o1 a grouch. If 1 felt that the boiler would go
ttntil my nexl visit, which might be in six months, I'd
pass ii to make everybody happy. There was nothing
seriously wrong in doing tin's, for if I doubted thai the
boiler would last until my next visit, it had to be made
right, kick or no kirk.
"This wen! on for years. In one plant, the B
works, I'd thus favored the engineer a few times. The
next time I was in the town T was anxious to gel over
to this plant for I knew the boilers needed inspection
About four o'clock that day and just as I was washing
up after I'd finished the A company's boilers, Wil-
kens. the engineer, came rushing into the washroom and
asked :
"'Did you hear about it ?'"
" 'About what ?' "
" 'Why, two boilers al tin ,'. works jus! exploded.
They say 1 I women were killed.
"I didn't, reply: I couldn't. My knees shook; I grew
hot and cold— ] was sick! When I arrived a
fire lines had been established and there was a heavy
police guard which wouldn't let me through. I looked
into an ambulance and saw three forms covered with a
sheet.
""Walking around to the next block I got into the yard
through an alley. In the debris I hunted for the re-
mains of the boilers, one of which T knew had a thin
crown sheet — the sheet I'd inspected and passed. As
! stooped to pick up a steam gage, my hand nearly
touched an arm, the hand of which bore a wedding ring.
I drew back trembling until the dampness at my feet
caused me to look down. My shoes were soaked in
blood! Oh! hut I was sick. I felt worse than a mur-
derer— I had murdered fourteen !
"Nearly crazed. I ran to the street and hoarded a car
for the hotel. I tried to hide behind a newspaper, inn
it rustled loudly in my shaking hands. I turned, pre-
tending to look out the window. Init the reflection of my
face in the glass frightened me more than the staring
eyes across the aisle.
"Investigation showed that the fireman had opened
tlie blowoff valve, and before closing it rushed away on
a signal from the engineer. Before he returned the
explosion had happened. This knowledge relieved my
mind, but I had Learned my lesson.
"Now ] take no chances ; I strike the sheets or blowoff
Miie- solidly. If they are badly corroded, I must know
it. Yes, they say I'm too exacting. Some complain to
our head office, hut I'm going to inspect rightly or I'm
not going to inspect at all.
"A good engineer never complains about a tho
inspection. Some p ■ ones do. hut we must proteel
them against their own shortsightedness
320
P 0 W E li
Vol. 11, No. 10
©EH
By Warren 0.
SYNOPSIS — The principal features of this hy-
dro-electric development are: A concrete dam
50 ft. high and 675 ft. • creates a stor-
reservoir having a capacity of 2,600,000,000
cu.fi.: two miles of conduit foi ing the
water from the dam to tin- power plant, consis
of a section of i ' tunnel, a
section of 11-ft. and 12-ft. diameter woods
t. diameter steel /ape;
gantic surge tank 50 ft. in diameter and 105
ft. high, mounted on a structura 00 ft.
high; four 8-ft. diameter sti cs equipped
with rat res of at
containing tour W,000-hp. horii
equipped with heart) flywheels, each driving a
rotor, together with the transform-
ing, switching and control a md, finally,
a transmission line J$ miles in length operati
60,000 volts.
The completion of the new Salmon River hydro-elec-
tric plant (Fig. 1). of the Salmon River Power Co.,
located near Altmar, N. Y.. and about forty-five miles
erates power for transmission ever lines owned and con-
trolled 1>\ separate and independent companies. All lines
in Canada are owned by the Ontario Transmission Co..
Ltd., a subsidiary corporation. In the United States
the power ruining from the Ontario Power Co. is dis-
tributed by the Niagara, Loekport & Ontario Power Co..
about 816 miles of transmission lines through the
western and central sections of New York State. The
latter company has leased the entire property of the Sal-
mon River Power Co. in perpetuity and acquired all its
capita] stock, thus securing for itself a new source of
power at the eastern end of its transmission lines, sup-
plementing that which it now receives from Niagara
and from its own steam plants at Lyons and Auburn.
Wateb Supply
The Salmon River, which is -1 1 miles long, has it-
source in the foothills of the Adirondack Mountains and
Bows through the north-central part of New York State
discharging into the eastern end of Lake Ontario. The
river drains a watershed, the tributary area of which is 190
square miles and in which there is an average annual rain-
fall of aboul sixty inches. In the 17 miles between Still-
water, where the dam is built, and Lake Ontario, the river
falls 650 It., and has a drop of more than 400 ft. in a dis-
tance of less than eight miles. At Salmon Falls the drop
i, 1 in ii. Figs. 2 and •'! show a general plan and profile
of the development.
The concrete dam. Fig. -1. which is located near Still-
water, where the river banks form ideal abutments, ereates
an artificial lake over 8 miles long and 5% square miles in
area. The crest of the dam is at elevation 935 and with
the crest at this height, the average net head produced
at the power house, less than two miles away, is 245 ft.
Fig. 1.
C 80SS-SE( I lo\ THROUGl
Plant
northeast of Syracuse, has attracted considerable atten-
tion to this source of water power, which, with the >■
tion of Niagara Fall-, is the greatest in the State of New
York.
The power from the Salmon River will join that coming
from Niagara, as the Salmon River plant has been
designed to operate in parallel with the Ontario Power
Co., of Niagara Fails. The latter, loi ated in Canada, gen-
The dam. constructed of concrete, is 675 ft. long and
has a maximum height of 50 ft., with an average thickness
of 51 ft. Tli.' cubical contents are 30,000 yd.
Water i- conveyed from the reservoir first through the
intake where the screens and head gates are located, into a
600-ft. section of reinforced-concrete-lined tunnel drilled
through the rock and having an internal diameter of 1".'
ft. The lining of the tunnel is in no instance less than
March o, 1911
POWEB
321
one foot in thickness and is reinforced with circumferen-
tial rods closely spaced. From the tunnel the water passes
into a 7825-ft. length of wood-stave pipe, 3450 ft. having
an internal diameter of 12 ft. and the remainder 11 ft.
Pig. 5 shows the manner in which the wood-stave pipe is
held circumferentially with %- and l-in. steel bands.
Each Wand is in three sections, all united by malleable-iron
first, or bottom course of the shell, is of l-in. plate with
triple-riveted butt joints. The thinnest plate in the tank
is '/, in. thick. The portion of the riser inside the tank
is stiffened every I ft. by Mx^.-in. angles to take care
of any temporary differences in the elevation of water
inside the riser and in the tank proper.
The 12-ft. riser from the distributor connects with
Figs. '. and 3. General Plan and Pkofile of tile Salmon Riveh Development
slices. Where the soil is soft the pipe is supported by
timber cradles. At ail other points it is laid on the
ground and banked with earth. To equalize external | in-
sure when empty] □ ; tl pipe and to permit air to escape
when filling, relief valves are provided at intervals. The
lower end of the wood-stave pipe is connected through a
specially constructed joint, packed with oakum and lead
wool, to a 1200-t't. section of lli/o-l't. steel pipe, which
conveys the water to the crest of the hill behind the power
house. At this point. Fig. 6, there arc
a number of novel and original features.
Surge Tank
First, there is a distributor, Fig. i.
which is a 12-ft. steel pipe of %-in.
steel plate, 210 ft. long and joined at
one end to the pipe line in a huge con-
crete anchor block, the other em! being
closed by a bulkhead. The bottom of
the distributor is 160 ft. below the crest
of the dam. From the center of the
distributor a 12-ft. riser branches off
to the surge tank. Fig. 8, the largest of
its type yet constructed. The surge
tank consists of a cylindrical shell 50
ft. in diameter and 80 ft. high, sur-
mounting a bowl bottom of 25 ft. in
depth, making a total height of 105 ft.
and having a capacity of 1,400,000
gal. of water. It is supported on lit massive steel col-
umns spaced as shown in Fig. i. which elevate the bot-
tom of the lank so ft. above the ground level. The total
height of the complete surge-tank structure is 205 ft.
The thickness of the bowl bottom plates is % in. and
the longitudinal seams are triple-riveted butt-strap joints ;
the horizontal seams arc quadruple-riveted lap joints. The
the surge tank by means of a special expansion joint.
In order that the accelerating or retarding head required
to produce the new velocity in the pipe line and demanded
by a change in load on the plant may be more quickly
established, the 12-ft. riser is reduced to a diameter of
10 ft. inside the tank. This interior riser is flared at the
top to a diameter of 15 ft. and terminates 5 ft. below the
top of the tank proper. In the annular opening formed be-
tween the 12-ft. riser and the 10-ft. riser at the bottom of
Fig. 4. Salmon 1,'ivf.i: Concrete Dam
the bowl, ports have been provided, so that water moving
toward the tank Hows partly into the main tank and
partly into the interior riser, and conversely, water flowing
downward through the 12-l't. riser Hows partly from the
10-ft. riser and partly from the main tank through tin
ports.
The surge tank aits as a hydraulic regulating device
322
POW EE
Vol. -11, No. 10
for the plant and to proteci the long pipe line from
shock. When the plant is in operation and a sudden de-
mand for more power irs, requiring more water, this
tern by sudden demand.- for and rejections of power may
be effectively damped before serious oscillations in the
water column are set up. Also, by the use of this "dif-
ferential" principle both the maximum head and the re-
quired storage capacity in the tank are reduced, making
Fig. 5. Twelve-Foot W >-Stave Pensto* k
i- supplied largely from the surge tank, while the velocity
in the pipe line is increasing to the required degree.
When the power Load is suddenly diminished or thrown
off the plant, the surplus water -urges into the tank, pro-
ducing a rapid rise in the interior riser and a slower rise
in the main tank. The head produced in the riser cheeks
the velocity of How in the pipe line and limit- the pres-
sure.
If. under very severe and unusual conditions of lead
change, the water in the riser should reach the top, it
would spill over into the main tank and be retained.
The ports at the bottom of the tank are carefully de-
signed ,-o a- to introduce just the right amount of re-
sistance to the flow of water to or from the tank proper
in order that any .-urge- produced in the hydraulic sys-
Bell-end
Connection
Fig. 6.
Surge Tame ox Hill Back of the Power
Plant
lrauli
possible lower construction co-ts and better
regulation.
Another interesting feature in connection witli the
surge tank is the provision which lias been made to pre-
vent freezing. The tank is housed in with a framed
w< len structure, which provides a -eric- of air spaces
!! -actings
for column bases
of surge tank
ELEVATION
Pig. ;. I'i.w wn Elevatiojj oi rra L2-Ft. Distributor
March 9, L915
iMi w i: Et
323
through which warm air is blown whenever necessary by
fans Located at the base of the tank.
Hydraulic Valves and Penstocks
Four 8-ft. penstocks are connected to the distributo]
through hydraulic valves of a new design. The normal
head under which these valves operate is 154 I't. An ex
terior view of one of the valves is shown in Kg. !l ; a sec-
tional view in Fig. 10. The valve consists of a casing
which supports an
interna] stationary
shell .1. headed
against the flow of
water, as indicated
by the arrow. A hol-
low movable plunger
/.' carries a bronze
ring 0, which seats
against a ring D.
The movement of
the plunger is con-
trolled by a four-way
valve ami suitable
piping. The pipe F
i- connected to the
penstock on the in-
take side of the
valve, the pipe F is
piped into the space
behind the plunger,
G into tin' space be-
tween the plunger
and the shell, and II
discharges to the air.
To close 1 he valve
the pressure in the
pipe E is put in com-
munication with the
pipe F. and pipe G
with II by means of
i he Pour-way valve,
thus putting pres-
sure behind the plun-
ger and gradually
closing the valve.
When opening the
valve the pipe E is
put iii communica-
tion with G, and /•'
with the pipe//. The
plungi r can be stopped ai anj point between its full
open and closed position, its exact position at any time
being designated on the indicator shown in Fig. 9. The
four-way valve is either hand or motor driven and can be
electrically controlled from the main switchboard in the
power house. In order thai the switchboard operator may
know that the valve is operating properly, a pilot lamp,
controlled h\ suitable contacts on the valve indicator, is
installed on the control switchboard in the power house.
From the valve chambers four 8-ft. steel penstocks,
which are anchored above ami below in heavj concrete
blocks and laid in trenches which arc back-filled, run to the
power house. Two are seen in Fig. 6, as they had not
been covered with earth at the time tin- photograph was
taken. The thickness of the -ted plate of which the
Ne \i; View of the
StJBGE Tank
penstocks are constructed varies from | g in. on the upper
horizontal end to 7S in. at the lowei end, where they en-
ter Hi,' power house.
Poweb House
The power house is constructed of reinforced-concrete
columns connected with heavy concrete beams. The pan-
Fig. 9. An s-Ft. Johnson Pemstock Valve
els around the large window areas are filled on the inside
with -ami-lime brick and with red brick on the outside.
The building is rectangular, with a projecting feeder bay.
In the feeder hay and along one side of the main generator
room i> a gallery about l'.1 ft. above the main floor. A
Id-ton electric crane, with main and auxiliary drive of
250-voli direct-i urrent motor.-, -pan- the generator room,
which i- 38 ft. wide.
All intake pipes, draft tubes and discharge tunnels
ate under the building, embedded in or formed of concrete
which rests on solid rock; the arrangement of this i-
showrj in the plan and elevation views, Figs. II ami 15.
Main Units
There are four turbines of L0,000-hp. normal ratine
of the Francis horizontal, single-spiral, double-discharge
Fie.
in. Section m, View ot tii e Pen-
STOCK V MA B
type, which are provided with outside-balanced wicket
gates op, oated b\ hydraulic governors.
The turbines have gua ranteed efficiencies of S"2 per cent.
at full load. 85 at three-quarter load, 80 at half load and
70 at quarter load. ( >n the turbine shafts are mounted
heavy flywheels to assisi in governing and to facilitate the
operation of the electrical equipment of the plant in paral-
lel with other plant- on the transmission system. Reliel
Vol. II. No. 10
valves on the turbines, operated by the
Minis, prevent excessive pressure
rises upon sudden closure of the tur-
bine gates. STos. 1 and 2 units are
shown in Pig. 14.
The hydraulic governors. Fig. 12,
are adjusted to permit of not more
than 15 per cent, increase in speed
e normal on the sudden removal of
i be full load carried by the generator.
r cent. Eor half load, 3 per cent.
or quarter load and 1.5 per cent, for
rie-tenth lead.
The turbines discharge into a tail-
race through short concrete draft tubes,
entering at an obtuse angle to pre-
vent eddies. The tailrace is under the
power house, which is built over the
lied of a branch of the river. The exit
uf the tailrace from the building is
closed by a curtain wall which pre-
\eiits the ingress of cold air.
The four generators directly eoupled
to the turbine shafts are G(i00-kv.-a.
capacity, 6600-volt, 25-cycle, three-
phase units. The exciter of each ma-
chine is mounted on an extension of
the --halt. Flu. 1 1. and is adapted to
voltage and power-factor control by a
voltage regulator. The pole faces of each
generator are provided with damping
grid-. The generators are of the semi-
inclosed type, and the cooling air is
discharged through a large opening in
the top of the casings. They are de-
signed to operate either as generators
or synchronous condensers, in order
that they may he used both for gener-
ating electrical energy and for power-
factor correction on the long transmis-
sion line from Niagara. Each is de-
signed to carry 20 per cent, overload
and i< also capable of operating at full
current output up to 7500 volts. The
limits of voltage regulation allowed at
normal kv.-a. load were for 10(1. 90
and 80 per cent, power factor. 12, 25
and 28 per cent., respectively.
Station Electrical Equipment
The electrical equipment for each
generator further consists of three
2200-kv.-a. single-phase, 25-cycle, oil-
cooled transformers. Fig. 13, with a
normal ratio of 6G00 to 34,650 volts,
the high tension in star giving GO. 000
rolts on the line: a 6600-volt, 1200-
amp., triple-pole, single-throw circuit-
breaker, automatic for reverse power,
and the necessary connecting cables and
auxiliaries. The duplicate high-ten-
sion busbars are hung from the roof.
over the gallery, upon which are locat-
ed the high-tension line and the trans-
former circuit-breakers ami line i
March 9, 1915
POW E R
Fig. 12. Hydraulic Governori
Via. L3. Oil-Cooled Transformers
PRINCIPAL EQUIPMENT OF SALMON RIVER POWER PLANT
No. Equipment Kind
4 Turbines Horizontal single spiral
4 Generators Alternating currenl
4 Generators Direct current.
4 Governors Lombard . ...
1 Surge tank Different ia!
Use
i units 37."»
Operating Conditions
n., 245-fl head
n , 6600 volts, 25 cycles, three-
4 Valves Balanced hvdruuh.
1 Crane Electric. . .
12 Transformers... Oil-cooled.
4 Circuit-breakers Single-thro
4 Circuit-breakers Single-throw
2 Circuit-breakers Reactance type.
3 Transformers... Self-cooled
10,000-hp
7920-kv -a max .Main units 37;
phi
150-kw . Exciter units 375 r.p.m, 125-245 volte
Speed-control, main units Belt-driven from generator shaft
50x105 ft .
1,400,000 gal. Regulation of pipe line
8-ft Controlling penstock water Hydraulically operated, electrically con-
trolled
40-ton Generator room Motor-operated
2200-kv.-a Generator to line voltage Single-phase, 25-cycle, GG00-G0.OOO volts
7920-kv .-a Between generators and
transformer 6600 volts, L200 amperes
7920-kv .-a. . Between transformers and
high-tension bus 6C,000 volts, 100 amperes
32,000-kv.-a.... Between high-tension bus
and line 60,0<>() volts, 300 amperes
100-kw Station service Delta-connected. GGOO to 2200 volts
Maker
Wellman-Seaver-Morgan Co.
Westinghouse Electric & MfL'.
Westinghouse Electric & Mfg.
Lombard Governor Co.
The Kennicott Co.
Wellman-Seaver-Morgan Co
Shaw Electric Crane Co.
Westinghouse Electric &. Mfg.
Westinghouse Electric & Mfg.
Westinghouse Electric & Mfg.
Westinghouse Electric & Mfg.
Westinghouse Electric & Mfg.
Fig. 14. Two of the Foub 10,000-Hp. Turbines and 7290-Kv-A. Generators
326
P 0 W E E
Vol. 41, No. mi
coils. Directlj under the buses are the necessary discon-
aei ting switches.
Fur station service there are three 100-kw. self-cooled
transformers which step the voltage from 6600 down to
820 volts. They are delta connected mi both sides.
On the main floor, under the gallery, are the generator
circuit-breakers, main and service transformers and a
storage battery for switch operation. The control switch-
hoard is on the lower floor of the feeder hay. and is of
the vertical panel, remote-control type
Transmission Line
Tlie transmission line from the power house to the sub-
station of the Niagara, Lockporl & Ontario Power Co.. at
By Ide L. Benedict
Instances are frequent where power-plant machinery
has been improperly selected. This may not have been
the resull of ignorance or misrepresentation, hut of fail-
ure to give due consideration to the probable operating
conditions. Cases of the installation of units of incor-
rect size are probably more numerous than those in which
an unwise choice of the type of prime mover has been
made. It would seem that we rely too much upon at-
taining ideal conditions, when estimating the performance
>f a new tv]
Fig, L5. Elevation or the Power Plani
Solvay, X. Y., is about 42 miles long and comprises two
circuits carried on steel towers with suspension insula-
tors.
The plant was first put into commercial operation in
April, 1914, with two units running. The third and
fourth units were placed in service in October, l!»lf. and
the plant is now carrying a maximum load of 23,000 kw.
The engineering work was carried on under the direc-
tion of V. G. Converse, chief engineer of the Salmon
River Power Co. Messrs. Barclay Parsons & Klapp had
charge of the engineering and construction of the dam.
and also acted as consulting engineers for the entire work.
Huuinn Knersy in Electrienl I nits — On an average & man
dissipates about 2.5 kw.-hr. per day. This is spent partly
in muscular action, partly in the production of heat in the
maintenance of the body temperature against radiation. There
is thus a continual power consumption of about 100 watts.
or . .ne-seventh of a horsepower. About one-half of this is
ii. nl in maintaining the body temperature. The human body
has ..bout the same heating effect upon the surroundings as
a 16-cp. carbon filament lamp. — "Scientific American."
machine. There may sometimes he
g I reason for this and the expecta-
tion is realized. On the other hand
the conclusion may have been reached
from a superficial survey of the oper-
ating factors, and the actual result-
fall far short of the prediction. Ex-
amples can l.e cited of new- gas-erjgii ■
installations of excellent operating
record which were soon displaced bj
steam turbines on account of the
rapid increase in the price of gas.
On the advent of the low-pressure
turbine too much was expected of it,
not only in effecting a remarkable
saving- jn fuel consumption, hut also
in providing a new lease of life, from
an economical viewpoint, for existing
engine equipment. While the ma-
jority of the low-pressure turbines
have been economic successes, there
are one or two exceptions from which
a lesson may he drawn
First, the low-pressure turbine is
dependent up. .n a favorable vacuum
being maintained, and secondly, a
good load must he carried upon the
unit. Otherwise the potential econ-
omy is sacrificed.
The accompanying curves, taken
from the records of such a low-pres-
sure turbine plant exemplify this
phase of power-plant engineering and operation. The aver-
age saving in coal consumption throughout the year was
somewhat less than 4 per cent., representing a reduction
from 4.25 lb. to about 4.1 lb. per kilowatt Under favor-
able conditions, the low-pressure turbine should effect an
improvement of over 25 per cent, and lower the coal rate
to 3 lb. or better. An analysis shows that the load is
a widely swinging one and the fluctuating condensing-
water conditions preclude high vacuum being regularly
maintained. Furthermore, the power consumption of
the condenser auxiliaries is abnormal on account of the
rise and fall of the water-supply level, ami as the station
furnishes only a direct-current output and the turbine
i- coupled to an alternator, converting machinery with it>
attendant losses is required. So the operation of the
low-pressure turbine is prejudiced, and it would he an
unfortunate commentary upon this type of prime mover
if all of these controlling factors were not made clear.
As will he observed, the load on the plant did not vary
sufficiently to have any appreciable hearing. The dif-
March 9, L915
P 0 AY E R
327
ference in coal rate from month to month is partly ex-
plained by the irregularity with which coal is received.
The curves show twelve months preceding and twelve
months succeeding the installation of the low-pressure
turbine. Some theories may be advanced as to the rea-
or the apparent irregularities. The high coal rates
i at about the same time as the heavy load. As a
-mi ion's economy should ordinarily improve with an in-
i rease in output, the cause for the variation may be due
to engines pulling loads at long and uneconomical points
of i utoff, or the hand-fired boilers may have been forced
to a point where their efficiency fell off rapidly.
Sometimes the winter coal rate will increase on ac-
count of the greater radiation losses and the introduc-
tion of colder air into the furnaces, if the condensing
equipment is not capable of operating on a low-terminal
temperature difference, and therefore does not utilize the
benefit of the low circulating-water temperatures. But
apparently, these circumstances do not exert much hear-
ing in this ease. Sufficient measuring and indicating
! Doffed lines indicate engine log
Full lines indicate combined engine
and turbine log
Curves indicate visual mean rates
'OCT. NOV DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.
COAL RATES
instruments were not installed to provide for a compre-
hensive analysis.
In attempting to obtain a clue fur these results it may
lie set down that the variations may follow from such
cause- a-: ( 1 ) change in quality of coal delivered; (2)
state of repair and adjustment of equipment, proper set-
ting (if valves, cleanliness of boiler tubes, leaks, etc.: (:!i
distribution of load between units, or the operating load
factor of the different units: (li the efficiency of the
operators during the periods under comparison.
Visual mean curves have been drawn so as to coun-
terbalance the irregularities in billing the coal and other
charges from month to month. The eoal rates when run-
ning with and without the' low-pressure turbine approach
each other closely except in April, when a happy set of
conditions seems to have been hit upon in the operation
of the low-pressure turbine. As compared with the n m-
condensing engine, the economy of the low-pressure ap-
proaches the proper point, taking the maximum dip of
the solid line, while in the month of August the compari-
son is somewhat startling. The station is subject to a
rapid swinging of the load over 15 per cent, either side
bS the mean, and this no doubt has an important ef-
fect upon the coal consumption.
The wav in which the load divides between the engines
and the turbine may account for a good part of the dis-
crepancy, particularly as the entire output of the low-
pressure turbine, which is direct-coupled to an alternat-
ing-current generator, must flow through a motor-gen-
erator set. with a loss of 20 per cent, or more, depending
upon the load carried.
Oil and scale on the blades id' the turbine won/d notice-
ably affect the ultimate economy, hut during the period
under discussion the turbine was in good condition.
The unit under consideration i- of LOOO-kw. capacity;
steam pressure carried, 1"><> lb. gage; and vacuum sought.
28 in. (30 in. bar.), though it ranges around 21 in. and
less.
In view of this development, which might have been
foreseen had these conditions been reckoned with, the
natural inquiry is what would have been the most ap-
propriate machine to have installed? The plant was
equipped with single-cylinder Corliss engines. Undoubt-
edly, a straight condensing turbine would have best sat-
isiied the requirements and provided a unit perse modern,
and would have obviated the perpetuating of the use of
the reciprocating engine, as has become necessary with
the installation id' the low-pressure turbine. Besides,
floor space might have hen economized, and it would
also have made it simple to carry out further extensions
both in consistency of type and arrangement.
One thing that should lead to careful consideration in
engineering work is that any failure to fully regard all
governing conditions will probably be cast up later as a
display of lack id' ability, and consequently the installa-
tion becomes a conspicuous error.
]R®dlesa§|ime<dl ISc&ir&oini lE^psvstisacnisti
This thermostatic trap was described in the April 25,
1911, issue of Powek, and was then manufactured by
John \V. Barton, Cleveland, Ohio. It has been slightly
redesigned, and is now manufactured by the Automatic
Steam Trap & Specialty Co.. Detroit, Mich. The former
trap consisted of an inner and an outer expansion tube
and a casing bidding the two heads. The redesigned trap
has hut one inner brass tube, an outside steel tube and
a valve. A short extension screwed onto the brass tube
seats against a tlat disk, which is adjustable for different
temperatures of .-team. In other respects the trap is the
same as the original one. The brass tube is five to
expand and as us length increases more rapidly than
that of the steel tube, when heat is applied it will seat
against the disk. Reinforcing ring- around the brass
tube tend to prevent buckling.
When the trap is first installed the disk is adjusted
so that the valve will close when the brass tube is full
ol' -team. When this steam cools into water the brass
tube shortens, pulls away from the valve disk and allows
the condensation to escape. Steam following the water
again expands the tube and doses the valve. This opera-
tion is repeated, and the system to which the trap is
attached is kept free of wafer.
Anthracite — When the first two tons of anthracite coal
were brought into Philadelphia in 1803 the eood people of
that city, so the records state, "tried to burn the stuff, but
at length, disgusted, they broke it up ami made a walk of
it." Fourteen years later Col. George Shoemaker sold »i li
or ten wagon loads of it in the same city, but warrants were
soon issued for his arrest for taking money under false pre-
tenses.
528
P 0 \Y E E
Vol. 41, No. 10
?s4iosiiS ©mi OvepEn&ULli:
£rMers\ili©ini Plant
By Thomas G. Thurston
SYNOPSIS — An article alive with practical sug-
gestions for finding the weak and the leak spots
in a refrigeration system, and putting the plant in
good condition for the next season's run.
The time is here when the demand on the refrigerating
system is lowest. Preparations should be made for the
time when part or all of the system can be shut down
for repairs to put it in good condition for next season's
run.
Notes should be made of the defects and troubles that
have been contended with during the season and steps
taken to remedy them. .Joints that cannot be kept tight
with reasonable tension on the holts should be marked
for attention when the system is shut down. Leaky
valves should receive the same treatment. If the am-
monia charge is loaded with oil and impurities, pump
it out and have it purified.
The Ammonia End of the Compressor
Open and go over every part of the compressor: Ex-
amine the cylinder for shoulders and score marks; see
that it is round and of uniform diameter throughout its
length. Examine the piston and rings and see that the
former is a snug fit in the cylinder and that the rings
fit in the piston grooves. See that the rings have suf-
ficient tension; if they have not they can be peened out
a little with a hammer, although this is a makeshift.
Examine the connection of the piston to the rod and make
sure it is firm. Caliper the piston rod and if it is worn
or scored have it turned or replaced with a new one.
If the old rod is turned, be sure and make a junk ring
for the bottom of the stuffing-box to keep the packing
from squeezing out between the smaller rod and the
bottom of the box. If the rod is much smaller than
the original the stuffing-box gland should be babbitted
to about one-sixteenth inch larger than the rod.
If the machine has false heads inspect them and the
seats for score marks and signs of ammonia blowing
through. Grind them in with emery or powdered glass
and oil, or, if they are too had, they will have to be faced
first.
Go over the valves, seats and cages thoroughly. If
the valves and seats are not much worn they can be ground
in : otherwise, get new ones. See that the valves fit
snugly on the guides and that the springs have the proper
tension. The correct spring tension can best be deter-
mined by the indicator. Any other way is merely guess-
work.
In most designs of valves there should he a small hole
in the valve or guide to let the latter act freely. If
tins opening is neglected the gas in the valve or guide
will compress or form a vacuum, depending on which
way the valve is moving, and interfere with its free
action.
Examine the check valve in the discharge; see that it
seats properly : grind the valve in or rebabbitt the disk if
necessary; be sure that it does not fit too loosely on the
guide, fur if it docs it may hammer and will not seat
properly. Clean, oil and grind in the relief valve and
see that it works freely. If the suction line has an auto-
matic check valve in it, this should be cleaned and oiled
and the valve and seat examined.
Some plants have an elaborate system of piping for
oiling the stuffing-boxes and for relieving gas from them.
These should be cleaned, as they generally accumulate
packing and dirt. Clean out the oil separator; if it
cannot be opened it can be fairly well cleaned by blow-
ing it out with a steam hose. Clean, oil and test all
the gages. Test all the thermometers if any are used.
The Steam End of the Compressor
The engine cylinder, piston and rod should receive the
same attention as similar parts of the compressor. Ex-
amine the valves and valve gear thoroughly. Caliper
the crosshead guides, and if they are much more worn
in the center than at the ends, have them bored or
planed. If the crosshead shoes are badly worn they should
be babbitted. Caliper the crosshead pins, and if they
are not round, have them turned. They may be dressed
with a file. See that they fit tightly in the hole in the
crosshead. While the machine is dismantled run a line
through the cylinders and see how the cylinder guides and
main bearings align.
Take the main bearings apart, clean them and see that
the oil grooves are open and sufficiently deep. Examine
the cranks to determine if they are loose on the crank-
shaft, or if the crankpins are loose in the disk. When
the crankshaft is placed in the bearings be sure to ad-
just the quarterboxes so that the shaft will line up witli
the cylinder. After the engine is assembled, adjust the
clearance on both the compressor and engine. On an
engine and a double-acting compressor this is practi-
cally fixed; on a single-acting machine the clearance is
adjustable and should be set as close as possible consistent
with safety. Some operators have run the piston clear-
ance as low as l/ei in., where the machine is equipped
with false heads. The writer believes it should never be
less than TV in.
The Condenser
The condenser should be examined before it is shut
down, and all joints that have caused trouble by leaking
should be marked. This applies to the joints that may
be tight, but have been drawn up with more than a rea-
sonable tension on the bolts to keep them tight. Leaky
valves should also be marked. Open a few of the coils,
and if there is much oil or foreign matter present they
should be cleaned.
Make a steam connection to the gas header, shut off
all the gas valves, open the ends of the liquid header or
disconnect the coils altogether. Then blow out the coils
one at a time by turning steam on the header and open-
ing the gas valves in succession until the oil and foreign
matter are blown out. "When this is done disconnect
March 9, 1915
P OWEIi
;;■;;>
the steam connection and pump about 100 lb. of air pres-
-ure on the header and blow the coils as before.
Clean the scale and mud from the outside of the pipes
with a wire brush if it is an atmospheric condenser. If
it is of the double-pipe type remove the return bends
and clean the inside of the pipes with a tube scraper
or a turbine cleaner. Open the water headers and clean
out the sand and scale that have accumulated in them.
Remove the bonnets from the valves on the gas liquid
line and pump out headers. Examine the seats and
disks and if they are scored or show signs of blowing
through or the babbitt i- squeezed out, they must be
ground in or rebabbitted. Renew the gaskets on all
the bonnets. If it is important to keep the machine
running continuously during the season, renew the gas-
kets between the valves and headers unless certain that
the gaskets are in good condition and will not I>1<'«" out
if they start to leak, hut may he drawn up without un-
due -train on the bolts.
The gaskets between the valves and the individual
stands are not so important, as a blowout on this side
of the valve puts only one coil out of service. For this
reason the gaskets between the valves and headers should
receive particular attention. If a gasket blows out be-
tween the stand and valve or any place in the stand, it
L- only necessary to shut off the gas and liquid valves,
pump out the coil and repair the blowout, when conven-
ient to do so. In the meantime the rest of the con-
denser may be kept in operation. For this reason it is
also important that the valves be tight. The gaskets in
tbe headers should also receive the same attention.
Renew the packing on all the valve stems, also the
gaskets in all the leaky joints. Draw up all bolts and
i! any are rusted so they cannot be turned with reason-
able effort, replace them with new ones. Inspect the
pipes and headers thoroughly for pitting and corrosion,
especially at the water and ammonia joints. If any of
them are badly eaten away put in new S.
Testing fob Leaks after Repairing
After everything has been thoroughly examined and
repaired, pump an air pressure on the condenser a little
higher than the maximum head-pressure carried. This
will show bail leak- or joint- that have not been tight-
ened. Make thick soapsuds and apply with a brush to
all the joints under pressure. Leak- will be indicated
by the formation of soap bubble-. Alter all the leaks
that have been found are taken up. pump the pressure
up again, shut the discharge valve on the machine and
see that the bypass valves arc tight, also the blowoff
valve on the oil trap and other connections to the dis-
charge line, [f there are no leaks and all the valves arc-
tight, the pressure should bold for a long time. If the
pressure falls rapidly there is a valve open somewhere
or a bad leak, and this must be found.
If the pressure falls gradually, a few pounds an hour,
it i- generally caused by small leaks that will take up
after the condenser is in operation or can be found with
a sulphur stick after the ammonia is turned into the
condenser.
After the high-pressure test, let the air out of the
condenser and pump a vacuum on the latter and let it
stand for several hours to see if it will hold; sometimes
a line or coil that will stand a high-pressure test will
not hold a vacuum for even a short time. About the
only way to locate these leaks is to hold a lighted can-
dle to the suspected joint; if it leaks the flame will he
drawn in. If the vacuum test is satisfactory, pump all
the air possible out of the condenser, and turn the am-
monia into it immediately (to keep air from leaking in).
until the pressure comes up to five or ten pounds. Xow
go over every joint with a sulphur stick.
Leaky Wateb Pipes ix Condenses
Tests must now be made for leaky water pipes if it
is a double-pipe condenser. The return bends must lie
off and the sulphur stick held in front ami at both ends
of each pipe in succession. Corroded pipes must be re-
placed by new ones.
When the leaks have all been attended to, pump full
pressure on the condenser and test it again. If this test
i- satisfactory put on the return bends and test these
and the water headers with water pressure.
Expansion Coils
Unless one is certain that there is no oil present in
the expansion coils, it is better to open a few of them
and investigate. If there is oil it should be blown out.
Make a steam connection to the coils, disconnect all the
coils in the case of a brine tank, and first blow each out
with steam. If it is desired to remove every trace of
oil. pump a solution of caustic soda through the coils
after blowing them. In either case they must finally
be thoroughly blown out with air.
Renew the gaskets on all the joints opened and tighten
the rest. Go over tbe suction and expansion valves and
repair those that may require it. If brine tanks are
used, clean them out thoroughly. Pipe bangers and sup-
ports around a brine tank deteriorate rapidly and should
be looked after. Any of the header- on the liquid or
suction sides of the tank that have caused trouble by
leaking should be attended to. After the coils have been
cleaned, test them as the condenser was tested, although
it is not necessary to use as high pressure.
L nhs wo Auxiliaries
Joints in the lines that have caused trouble during
the season should have the gaskets renewed. Remove the
bonnets from the stop valves and examine the seats and
disks. Note the position of the valves in the line. Nearly
all ammonia valves are of the globe or angle type and
should be placed in the line so that the flow will lift the
disks off their scats in case they come loose from their
stems. If the valve is placed in the line in the reverse
position and the disk comes loose from the stem, it will
act the same a- a check valve and stop the flow. This
is dangerous, especially in a discharge line. Inspect the
lines for pitting and corrosion. If any are rusted badly
they should be renewed: if any of the liquid or suction
lines are uninsulated they should be covered ; if the liquid
receiver is in the engine room it also should he covered.
Inspect the brine pump closely for pitting and honey-
combing in the surfaces exposed to the action of the
brine. The writer remembers one case where the wall
between two valve chambers became so weakened from
this cause that a large piece blew out and disabled the
pump.
m
A High Boiler Pressure is to be carried on ill'' battleship
"Nevada," now Hearing completion — 295-lb. gage. Oil-fired
Yarrow-type boilers will lie use
330
1' ( ) \Y E R
Vol. 41, No. 10
oulers
By J. C. Hawkins
^©r-TunIb®
SYNOPSIS — Simple and thorough direction* for
talcing out and putting in tubes in various kinds
of boilers. What troubles to expect when expand-
ing and beading tubes. How to get a bagged tube
through the tube sheet. The use of tools to do this
kind of work.
Renewing Tubes ix Horizontal Tubular Boilers
The location of the tube to be renewed will govern to
some extent the procedure in getting it out. If the tube
can be taken out at the lower manhole it can be cut oil'
at both ends inside the heads with a bent chisel or with
an inside tube-cutter. Fig. 2. The bead on the outside
of the sheet is then cut off with a chisel and the tube
ripped through the seat. The ripper, with dimensions, is
shown in Fig. 1. In ripping the tubes the workmen
should be careful not to cut the tube seat. After the
cut is made the ends are closed, Fig. 3, and the piece
knocked out. If the tube cannot lie taken out at the man-
hole it must come nut through the tube hole.
Tubes are usually covered with hard scale and are
sometimes bagged or blistered, so it may save time to
run the tube-cleaner through the tubes to be taken out.
When a tube is to come through the tube hole it is not
cut inside hut the ends are ripped and closed up and
the tube forced out through the hole.
This may be done in many different ways and the one
to be chosen will depend chiefly on the condition of the
tube. It may be forced out a few feet with a sledge-ham-
mer and a block of hard wood on the back end. but there
is but little room at the back chamber to insert a long
block or liar to drive it out. It may he possible to get a
flat bar down between the tubes by getting on top of them
and swinging the bar against the end of the tube. A
chain hoist or block-and-fall hitched to the projecting
end of the tube and to the wall will help. If the tube
is badly scaled, striking it with a hammer close to the
head will help to knock off the scale. Sometimes, turning
the tube with a pipe wrench or chain tongs will screw it
out of the sheet, especially if a chain hoist i< attached to
the end to pull it along. After it has been forced part of
the way out the projecting end ran he rut off with a pipe
cutter and a new hitch taken on the remaining part.
As the back end will be battered up in driving the
tube out it will not come through the hole without being
closed up; this can be done from the outside with a
hammer and chisel. Often, more damage is done to the
tube hole in getting an old tube out than by working
the boiler several years. After the old tube is out the
seat is cleaned and the new tube slipped in. Some engi-
neers recommend that the end- of new tubes be annealed
in a charcoal fire before putting them in. to make them
more homogeneous and prevent them from cracking while
being expanded. This is not necessary if precautions are
taken to put the tube in properly so that it will not be
stretched excessively in expanding.
In some fire-tube boilers copper ferrules are used to
fill the space between the tube and the sheet. Thi- is
not necessary unless the tube hole has been stretched by
repeated expanding. Strips of copper or copper ferrules
should be used to fill the space. Whatever the material,
it should be softer than the head to prevent stretching
the tube sheet. Copper gives the best results. The tubes
in a fire-tube boiler should project through the head about
one-quarter inch on each end to allow for beading after
the tube is expanded. If it extends more than this, the
tube is likely to be cracked in beading over. The ends
should he expanded tight before heading. Before start-
ing to expand the tube, see that both ends extend through
the proper distance, then have a helper hold the front
end tight with a bar to prevent it from slipping while the
other end is being expanded. In placing the expander
in the tube care should be taken to have the rolls extend
an equal distance at the sides of the sheet and that the
tube expands gradually all around to prevent splitting.
There are two types of expanders — the prosser and
the roller, or dudgeon. Fig. 4. The former does its work
by a turned taper wedge being driven into the center of a
block made up of a number of wedge-shaped sections.
The roller expander, which gives the best results and is
generally used, consists of a frame carrying th zee steel
i i fr
Tools fob Cutting and Beading Boiler Tubes
rolls forced out against the tube by a taper plug. The
plug is tapped lightly to set the rolls out against the
tube and is turned to roll the tube against the seat. If
the tube hole is not round the tube will be expanded tight
into all the cavities by the roller.
One difficulty sometimes encountered by an inexperi-
enced man in using the roller expander is that when the
tube is a loose fit the plug is driven in snug at the start.
This will tend to stretch the tube at three points, and
when turning the plug the rolls will not move out of
these spots. If this occurs the rolls will have to be
loosened, set in a different place and the tube gradually
rolled until these spots »re worked out. Sometimes this
March 9; 1915
TOW E \l
331
causes much trouble, but if the pbag is tightened grad-
ually as it should be, no trouble will be given.
Sometimes the workman is at a loss to know when
to stop rolling. As soon as the tube is rolled out tight
the rolls will seem to be turning on a smooth surface and
the plug will lie tight when tapped with a hammer. It
is best to stop at that time and examine the joint. If
there appears to be spots that are not rolled out tight the
expander should be used again. Afer the tube is ex-
3Q
]ieB
3L
U
Taper Bolts Dudgeon for Water Tube Boilers
FIG.4.
Tube- Expanding Tools
pander! the ends should be beaded over flat against the
head. This can be done best with a beading tool. Fig. 5.
The bit of these tools should be about % or i/o in. wide.
Tool A is used first to draw the edges over, striking
lightly to prevent splitting, and B is used to draw it down
fiat against the tube sheet. Fig. 6 shows proper and im-
proper beading.
Replacing Tubes in Water-Tube Bqileks
Water-tube boilers are built in so many different shapes
that no rule applies to all boilers. In the Babcock
& Wilcox, Heine and some others of similar design,
all the tubes except those in the bottom and top rows will
have to come out through the tube hole. Those in the
bottom row usually have to be replaced much more often
than the others.
The easiest way to get out a bottom tube is to cut it
at both ends with the ripper, Fig. 1, made long to extend
through the water leg and close the ends up. The tube
may then be cut in pieces and easily taken out by cutting
it in the furnace near the bridge-wall and again back of
the bridge-wall. If the boiler has horizontal baffles on
the lower tubes it need not be cut. The most convenient
way of cutting a tube is with the five-wheel pipe cutter,
Fig. 7, but it may be done with a plain three-wheel cut-
ter by turning the tube with chain tongs. Tubes above
the bottom row must come out through the tube hole.
It is a hard job to get bagged tubes through the tube
holes. If the enlarged part can be reached with a long
chisel between the tubes it may be split and closed up to
go through the header. After being driven as far as
possible from the back end it will have to be treated in
the same way as in fire-tube boilers. It has been neces-
sary, where the tube was badly bagged, to put a clamp
on and use a jackscrew on each side to get it out.
Tubes in water-tube boilers are not beaded as in fire-
tube boilers, but are "belled'' or flared out; that is, ex-
panded to greater than the original diameter outside the
header. This is done by first expanding the tube in its
scat, then pulling the rolls out so that the end projecting
beyond the header, which may be from Vi to % in., will
be expanded to a diameter about ]/i >n- larger than the
tube. In putting in the new tube care should be taken
to replace the baffle brick, which may fall out when the
old tube is removed. The best expander for water-tube
boilers is made as shown in Fig. I. This is similar to
the plain dudgeon, but the end which carries the adjust-
ing collar enables the collar to be set at any distance from
the rolls. The advantage of this is that the center of the
rolls may be set over the tube seat irrespective of the dis-
tance the tube projects through the header. The plug
used in this expander is made long enough to extend
through the header to give plenty of room for opera-
tion.
The tubes in the vertical boilers of the Wickes and
Cahall type are removed through handholes in the head
of the steam drum and the new tubes are put in in the
same manner as in horizontal water-tube boilers except
that the tube must be blocked up in place in the mud
drum while the upper end is being expanded and belled.
In Stirling boilers the tubes are so spaced (except in
some of the older types) that any tube may be taken out
without disturbing any other tube. A Stirling boiler of
given horsepower may be high and narrow or low and
wide. As the tubes are not all the same shape or length,
it is necessary to order them from the makers, stating
the type and size of the boiler and for which row they
are wanted. The rows are numbered from back to front,
No. 1 tube being the one nearest the back wall between
the back drum and the mud drum, No. 2 is next toward
the grates, etc. They are numbered in the opposite di-
rection to the flow of gases.
To get these tubes out, rip the ends about six or eight
inches at the lower end and four inches at the top end.
Close up the end and push it down into the mud drum
until the top end comes out. Swing it around and pull
it out, then twist it around until it will slip out between
the other tubes and through the door in the setting.
This is sometimes quite a puzzle, but unless the tube is
badly warped it will come out easily. The new tubes are
marked "Top" on the end that goes into the steam drum
and can be put in only one way. Each is also marked
with the number of the row in which it belongs. Roll
them in as mentioned. They must be blocked up in
place and the top end rolled, first being particular to get
the bend in line with the others. If this is not done
trouble will be experienced in taking out the tube next
to it. The first two or three rows next the fire are most
likely to give trouble and are generally badly warped.
These tubes should be belled in expanding, not beaded.
In any boiler where the seat is in good condition and
the tube properly expanded there is small chance of leak-
age, but as a precaution the boiler should be given a hy-
drostatic pressure test at one and one-half times the work-
ing pressure.
Calking a:td Riveting
Each time the boiler is out of service the tube ends
and joints should be examined for leakage, which usually
shows as a grayish-white substance on the fire side of the
plate. If the seams appear to have been leaking, they
should be calked with a round-nose tool, Fig. 9. The
calking should be done while the pressure is off or \er\
oo2
POW EE
Vol. 41, N<
low. If on testing after calking it is found that the leak
cannot be stopped, some of the rivets may have to be re-
placed. If it is a lap-riveted. Longitudinal seam the leak
may be caused by a lap crack and the inspector should
be called in to examine it. Although reriveting may be
done by the engineer, it is best to call in a boiler maker.
Should the shell over the lire become bagged and, require
a patch, the job should be turned over to a boiler maker.
If the bag is not bad enough to need a patch, it may be
driven up by heating it with a blow-torch, beginning at
the outer ed^e and gradually driving it up. Have a
template made of the radius of the outside of the shell as
a gage.
Replacing Headers in Water-Tube Boilers
At the first glance this appears to be a hard proposi-
tion. Renewing a header in a Bahcock and Wilcox boiler
is no worse than renewing several tubes when they have
to come out through the tube holes. These headers
are cast steel and must be ordered from the factory, stat-
Tools for Removing Boiler Tubes
rag the number of tube holes and whether the header
is for the front or back end. Sometimes the front head-
ers become cracked at the lower end by the brick below
the header falling out, exposing the end to the heat of
the furnace, and as the pockets below the lower tube
usually contain some scale, the header becomes over-
heated. A header may be ruined by having a piece cut
out of the tube seat in ripping out an old tube.
In one instance five headers were cracked on the
front end and two on the back end, when the blowotf pipe
pulled out of the flange fitting, draining the boiler and
causing the tubes to overheat. The feed water was on
at the time and as this came in contact with the over-
heated headers they cracked.
To replace these headers an assortment of special tools
is required. As the tubes arc usually in good condition,
except possibly the bottom one. the header is split off
the tubes. This is done by a block made to lit the tube
cap-hole and split in half, having a taper slot and wedge
as shown in Fig. 10. The tube cap-hole is nicked with
a chisel at the top and bottom and will usually split from
one hole to the next. This leaves the tubes in good order
but with the ends expanded. The nipple connecting the
top end of the header to the steam drum is then split with
the ripper, closed up and then pulled out.
After the old header is removed the ends of the tubes
are swedged down to the original size. They are heated
in a charcoal furnace, Fig. 11. made of a short piece
of 5-in. pipe having one end drawn down to IVi m- aud
the other capped. In the lower side of the cap is con-
nected a 1 -in . pipe 3 ft. long to act as a handle and to
which the air pipe is connected. A hole in the top of
the 5-in. pipe with a hinged cover admits fresh fuel. The
air supply is taken from the air-compressor line or other
source. A piece of firebrick is placed in the tube about
a foot from the end and the heater slipped over the end
of the tube. It will only take a lew minutes to heat
the tube to a brighl red.
The swedge used to draw the end down should be made
as shown in Pig. 12. This is turned out of a solid piece
of machinery steel. The bore is tapered from 4% in.
at the mouth to 4 in. at the end of the taper, and straight
from there to the bottom. This is driven on the hot tube
with a sledge and if driven quickly only one heat will be
necessary. To prevent the rear end from being loosened
while swedging, block it by bracing to the wall or a solid
part of the boiler. After the tube ends are drawn down,
all the tube and nipple holes are cleaned out in the new
header and it is slipped onto the ends of the tubes, which
will have to be raised up and entered with a bar. Two
pieces of wood 2x4 in. and about three feet long are made
with holes bored to slip over the stud of the tube-hole
caps, one in the new header and one on each of the old ones
on each side, top and bottom. This brings the header
up to place and square with the tubes. Care must be
taken to get the header exactly in line, because if this is
not done, much trouble may be given in putting in new
tubes at any future time; they will bind on the adjacent
tubes and will not go through the baffle-walls if the header
is crooked.
After the header is in place and properly squared up
with the tubes, the nipple holes should be lined up with
the throat piece, and also with the mud-drum end if it
is a rear header. Sometimes, with these holes in line, the
tubes do not sufficiently extend through the holes to al-
low them to be belled. The cause may be that the header
on the opposite end has been pushed out in swedging the
tubes ami can be sprung back. If this cannot be done,
it will be necessary to push the header on farther and roll
the nipples in at a slight angle. Cut the nipples from
a piece of new tube and expand them in place with the
adjustable expander, using the jointed plug shown in
Fig. 4. The top end should be expanded first. The
bottom end of the top nipple may be rolled through the
top tube-cap bole with the jointed plug. In rolling the
mud-drum end of the bottom nipples with the loose
collar of the adjustable expander reversed to increase the
distance between the collar and the rolls, taper rolls are
used instead of straight ones. The plug is entered through
the lower tube-cap hole. This will bell the projecting end
of the nipple. Before expanding the nipple in the header
make sure that it is square with the tubes, especially
if it is on the front end.
After the work is completed a hydrostatic test of one
and one-half times the working pressure should be given.
Some of the joints on the opposite end from the new
header may show signs of leakage and will have to be re-
expanded. This work of replacing headers may be done
under the supervision of the engineer
March 9, 1915
fOWEE
33:3
rav<
'creeims ®& Delra^
>Y C. F. HlRSHFELir
SYNOPSIS — Endless screens specially designed
to simplify the washing operation. If desired
they may be washed continuously while in opera-
tin n.
An interesting installation of traveling screens for
screening the circulating water has just been completed
at the Delray plant of the Edison Illuminating Co., of
Detroit. This plant contains eight vertical-type Curtis
turbines with an aggregate rated capacity of around 93,-
000 kw. The circulating pumps which serve the condens-
ers of these units have an aggregate capacity of about 173,-
000 gal. per min.
This large quantity of water is drawn from the De-
troit River, on the bank of which the plant is built. After
flowing through the condensers it is returned to the river
at a point farther down stream. At all times of the year
the water is a] it to contain large quantities of floating and
submerged debris of one sort or another, and in the fall of
the year it generally carries large quantities of grass and
other marine growths which have broken loose from the
flats at the lower end of Lake St. Clair and at the en-
trance to the river. At certain periods large quantities
of fish of various sizes also appear at the plant.
To prevent the clogging of pump runners and of con-
denser tubes, it is therefore necessary to screen the water
thoroughly before it is circulated through the plant. Be-
fore the installation of the traveling screens this was done
by passing the water first through gratings or trash racks
and then through vertical screens. A so called screen
house is located at the plant end of the intake canal.
The water flows through arches under one wall of this
house and then through the gratings, which give it a rough
screening. These gratings are about 6 ft. in width and
Washing
Jets
\\ Direction
of Travel
Fig. 1.
Are lngem i-.vr of
Screens
Fig. 3. Bndless-
Belt Screen
a little over 7 ft. in length. They are made of %.\3-in.
flat iron bolted together with broad sides adjacent, and
with %-in. spaces between neighboring bars. They are
set with the edges of the bars toward the current and at
an angle as shown in Fig. 1, two gratings being joined
end to end to give a total length, or height on the incline,
3f the Edison Illuminating Co. of
of about I41/0 ft. There are twelve of these units ar-
ranged along the length of the screen house. Removable
gratings in the floor above facilitate inspection and clean-
ing.
After passing through the gratings the water strikes
the vertical screens. These consist of copper-wire screen
fastened upon a rectangular frame made of channel and
angle irons. The frames are about 9 ft. wide by about
12 ft. high and are divided into four rectangular panels
Fig. 3. Screen House Partly Completed
by horizontal and vertical cross-members. Each panel
is braced by two diagonals. This construction affords a
stiff frame and does not give large unsupported areas of
screen. The wire screen is so woven that the mesh is
rectangular and the openings measure approximately 14
in. in each direction.
These screens are arranged in units of two each. The
back of one screen of a unit is placed adjacent to the
face of the other screen of that unit, thus making the
water flow through the two in series. The two screens
of a unit are dropped into vertical channels which serve
as guides and support them in a vertical position with
their lower edges resting on the bottom of the water
way. This arrangement makes possible the raising of
one screen of a unit for washing without entailing the
closing of gates or the passing of unscreened water.
There are six of these units distributed along the length
of the screen house on a line parallel to that of the grat-
ings already described.
In ordinary operation all of the screens were washed
three times per day, but when the water contained large
quantities of marine growths it was often necessary to
wash screens continuously, and even then the water in the
rear of the screens frequently fell to an alarming extent.
When a screen is to be washed, the checkered iron floor-
plates above it are first raised and moved out of the way
by a small hand-operated winch carried on a car rolling
on a track laid in the screen-house floor. One screen is
then raised by means of a traveling crane and placed in
J34
fc>0 W EE
Vol. 41, No. 10
a wash box, which is mounted on wheels and travels along
the rails just mentioned. This bos is open on the side
opposite the rear of the screen when in position, and the
screen is washed by means of a fire hose and nozzle which
plays the water against the rear of the screen, thus driving
out all debris which has been caught in the mesh and forc-
ing all accumulations off of the face or front side of the
screen. The wash water, with its burden of trash, (lows
when a unit is raised is prevented by closing a gate at the
entrance to the canal or passage in which that unit i-
housed.
The screen house is shown partly completed in Fig. '■'>.
with one screen lowered into place and the rest raised in
the position they would occupy when being inspected or
repaired. The circulating water flows from under the
trestle at the right, through the screens, and into the old
Fk;. 4. Several Units iv Operating Position
to waste through a spout fastened to the bottom of the
wash box.
The new screens were designed to simplify the washing
operation. They can be washed continuously while in op-
eration, if desired. Each unit consists of an endless belt
carried over sprocket wheel- at tin- top and bottom of a
frame, as shown in Fig. '2. The belt- are made of panels
formed of a light frame and wire screen similar to that
used on the older screens.
The belt can he moved by means of a geared motor in
the direction indicated in Pig. 2. the speed being 15 ft. per
min. The debris collected on the face of the belt can thus
be carried up over the top and down the back and washed
off into a trough, as shown in the drawing.
For ordinary water conditions, the screen- stand sta-
tionary mo.-t of the time, each screen being moved and
washed once in four or five hours. In case of very bad
water, it is. however, possible to wash all screens continu-
ously, thus precluding the possibility of 'jetting low water
in the plant because of fouled screens.
Seven of these screens have been installed in a new
screen house located over an enlargement in the old in-
take canal, and there is room for the installation of three
more. Each frame with its motor and screen belt forms
a unit and is located in a separate compartment or canal
between concrete walls. These walls carry inclined guides
on which the frame of the unit is supported and on which
it can be slid upward and out of the water for inspection,
painting or repairs. The passing of unscreened water
screen house, which can be seen to the left. The interior
of the completed screen house is shown in Fig. L with
seven screens in operating position.
Gripwell pulley covering i- a cement to be used on
the face of pulleys to prevent the slipping of the belt
and to permit of running it loose. It is applied to the
pulley, which has been cleaned with a strong solution of
sal soda dissolved in water to remove all grease, etc., in
a thin coat with a finish and is then allowed to stand
until hard and dry.
In the case of large belts a covering of canvas 14 in.
narrower than the face of the pulley is applied to the
latter about twelve inches at a time, and rubbed down
hard with the cement until the pulley is covered.
It is claimed for this covering that it prolongs the
life of the belt, the bearings and the machinery, that it
eliminates the taking up of bell- and 1- waterproof.
This pullev covering is manufactured by the Gripwell
Pulley Covering Co., Hollis, L. I.. X. Y.
Tantalum is much harder than diamond, as is shown by
the fact that the only effect produced by a diamond drill,
worked day and night for three days on a sheet of metal
1 x in. thick, with a speed of ">000 r.p.m., was a slight dent
in the sheet and the wearing out of the diamond. When
red hot, tantalum can be easily drawn into wire or rolled
into sheets.
March !), 1915
P 0 W E B
33o
irect-Ctirreir^tL Ainnmskftiuipe Wimidliimi
'rimicapiies
Bv Jacob Gintz, Jr.
SYNOPSIS — Directions for the proper spacing
anil co ii ne cling of coils in both scries and parallel
windings.
The principle of armature winding is nothing more
than placing a number of coils, properly spaced and con-
nected to the commutator, so that they accumulate the
induced electromotive force produced in the various coils
which are connected in series between the brushes.
There are two types of direct-current windings — lap,
br parallel, and series, or wave, windings. These are
again divided into classes according to the number of
winding elements per slot; that is, if a winding has one
element per slot it is called a "one-layer winding," and
if it has two elements per slot it is called a "two-layer
Winding." Two winding elements form one complete
coil, and the distance that these two elements are apart
depends upon the number of coils and poles and is ex-
pressed in the number of winding spaces.
^^^^ ^r^^^i^
even if it is made odd as explained above. This applies
in lap, or parallel, windings only.
When the spread of a coil has been found, the distance
from the end of one coil to the beginning of another is
Y ± 2 = Yf
where Y is the spread of the coil, counted across the back
end of the armature (the end away from tin' commutator I
and ) j tbe front pitch, also expressed in the number of
winding spaces, hut counted across the front end of the
armature. The pitch Yf, however, is not a winding
pitch, hut merely the distance from the end of one coil
to the beginning of the next. In many cases it has been
found that instead of considering the pitch }'/, it is easier
for the winder to know that the winding is to lie placed
from right to left or from left to right and that the be-
ginning of the second coil is to be two winding spaces
from tin' first.
There is an advantage when using — 2, in that the ends
of a coil do not cross one another in connecting to the
9 10 II 12 13 U 15- 16 17 16 19 20 21 22 23 24 0>ilN?
i — i i i * ' ■
Pig. 1. Front Pitch Fig. 2. Fhont Pitch
Less than Bace Greater thax
Pitch Back Pitch
When an armature is being prepared for winding, tin1
first step is to insulate the slots, the ends of the core,
the shaft and any other parts of the metal with which the
winding may come in contact. The materials used for
this purpose are fiber paper, shellacked canvas or muslin
on the smaller armatures, and on the larger ones, micanite,
press-hoard, empire cloth and various other materials.
The coil must he so placed that both its elements do not
come under the influence of the same field polarity at the
same time, that is, while one side of the coil is influenced
by a north pole the other side must lie influenced by a
south pole. The distance between opposite sides of the
same' coil is called the pitch, or spread, and is found by
the formula
(^A = Y
P
in which C is the number of coils to be placed on the
armature, A the number of times the current divides at
the negative brushes (once at each negative brush ). /' the
pairs of poles and )' the spread of the coil, expressed in
the number of winding spaces. The value of Y must
be an odd number. Should it result in an even number,
it must be made odd by adding one. If it results in a
mixed number, drop the fraction, and if the remaining
whole number is odd the value of Y will be the same,
;j. Winding Laid Out in Accordance with Data
in Table 1
commutator, thus obviating the danger of short-circuit.
When -+-2 is used the leads will cross as shown in Fig. 2.
In Fig. 1, Y = 5 and Yf = 3
In Fig. 2, Y = 5 and Yj = 7
If the connections in Figs. 1 and 2 arc applied to two
armatures and both are run in the same frame, that in
Fig. 1 will run in one direction and that in Fig. 2 in
the opposite direction.
In lap, or parallel, windings there will be as mam
brushes set around the commutator as there are poles in
the machine. If such a winding is run with less brushes
than poles the entire winding will not be active, and in
the ease of small machines sparking at the brushes would
strongly interfere with operation.
For a practical example of a lap, or parallel, winding
consider an armature having 24 slots and 21 coils to be
placed in a four-pole machine.
In the winding where there is a like number of coils
and slots (each coil being represented by two winding
elements) there will he two winding elements per slot, and
it will be termed a two-layer winding. There will also
be 2 t commutator bars, since there must be as many bars
as active coils. In a four-pole machine the coils must
spread at leas! one-quarter of the circumference, or 180
electrical degrees Now 6nd the spread or pitch expr<
336
P ( ) W E R
Vol. 41, Xo. 10
in the number of winding spaces, with C = "24 and .1 =
2. In lap- or parallel-wound armatures there are as
many brushes as poles; then two brushes will be nega-
tive and two positive, and as the current will divide once
at each negative brush, there will be two divisions of
current. Also P = 2, since there are 4 poles (one north
and one south pole make one pair). Applying the for-
mula ;
0 + -l v 24
—5— = 1, 01 —
26 or 22
= 13 or 11
While it is possible to use either 13 or 11 winding
spaces, one spacing having no electrical advantage over
the other, it is better to use the smaller value, because it
requires less wire to wind the armature, saving material
and cost of manufacture.
Having chosen 11 winding spaces for the spread of the
coil, then the first coil will be placed in winding spaces
Nos. 1 and 12 (11 spaces between). This being a two-
layer winding, space No. 1 will be in slot No. 1 and
space Xo. 12 will be in slot Xo. 6. To locate the begin-
ning of coil No. 2, apply the formula, Y ± 2 = Yf. This
will give the number of winding spaces to be counted
back from the end of coil Xo. 1 to the beginning of coil
Xo. 2. Remembering the advantage and disadvantage
TABLE 1
Coil
Spaces Xo.
Slots Xo.
No.
Spaces Xo.
Slots Xo.
1 and 12
1 and 6
13
25 and 36
13 and IS
3 and 14
2 and 7
14
27 and 3S
14 and 19
5 and 16
3 and S
IS
29 and 40
15 and 20
7 and IS
4 and 9
16
31 and 42
16 and 21
9 and 20
S and 10
17
33 and 44
17 and 22
11 and 22
6 and 11
IS
35 and 46
18 and 23
13 and 24
7 and 12
19
37 and 48
19 and 24
15 and 26
8 and 13
20
39 and 2
20 and 1
17 and 2S
9 and 14
21
41 and 4
21 and 2
19 and 30
10 and 15
43 and 6
22 and 3
21 and 32
1 1 and 16
23
45 and S
23 and 4
23 and 34
12 and 17
TAB
24
.K 2
47 and 10
24 and 5
Spaces Xo.
Slots Xo.
Coil
No.
Spaces Xo.
Slots No.
1 and 8
1 and 4
9
17 and 24
9 and 12
3 and 10
2 and 5
10
19 and 26
10 and 13
5 and 12
3 and 6
11
21 and 28
11 and 14
7 and 14
4 and 7
12
23 and 30
12 and 15
9 and 16
,j and 8
13
25 and 2
13 and 1
11 and IS
6 and 9
14
27 and 4
14 and 2
13 and 20
7 and 10
15
29 and 6
15 and 22
S and 11
parallel windings only), this number of bars, known as
the "lead pitch." being determined by dividing the num-
ber of commutator bars by twice the number of poles.
If this results in a mixed number it should be increased
to the next whole number. The reason for these con-
nections is that when the coils are under commutation
they should be in neutral position.
When coil AB. Fig. 4, has moved to the position A'B',
its conductors are moving parallel with and are not cut-
ting the lines of force; hence, they will not produce an
electromotive force. At the same time the commutator
bars, to which the coil leads are connected, are under the
brushes C. If the coils were connected as in Fig. 5 with
the brushes set as in Fig. 4, it would be impossible to
operate the machine, because there would then be a dead
short-circuit of the coil whose liars were under the brushes.
In some types of armatures there are two or three
times as many commutator bars as there are slots in the
armature core, the coils being wound with two or three
wires in hand, which is the same as winding so many in-
dividual coils and connecting them together as one. There
are two methods of connecting the coils to the commu-
tator, namely, in parallel or individually. When two
or more coils are connected in parallel it is to do away
with the handling of large conductors and to make it
easier to wind and shape the coils; in this case there
of the minus and plus values of --' in this formula, then,
Y ± 2 = Yf, or 11 ± 2 = 13 or 9. Taking the minus
value of Yf, which is 9, and counting 9 winding spaces
back from Xo. 12 will bring the beginning of coil Xo. 2
in winding space No. 3, in slot Xo. 2. Then, spreading
the second coil 11 winding spaces between Nos. 3 and
14 will bring it in slots Nos. 2 and 7. Table 1 indi-
cates the number of the winding space and the number
of the slot between which the coils are wound.
By following this table Fig. 3 is constructed. The
spacing of brushes, expressed in the number of commu-
tator bars from the toe of one brush to the toe of the
next of opposite polarity, is determined by dividing the
number of commutator bars by the number of poles. In
Fig. 3, 24 liars -f- 4 poles = 6 bars from one brush to
the other.
In connecting the windings to the commutator one
should know how the brushes will be set in relation to
the polepieces. If they are to be set as in Fig. 4. the
beginning of each coil should be connected straight out
from the slot to the commutator bar. or if they arc ., t
as in Fig. 5. the beginning of each coil will be connected
a certain number of commutator bars to the right (in
Pig. I Fig. 5
Winding Decexdext ox Setting of Brushes
will be as many commutator bars as there are slots. When
there are two or three times as many commutator bars
all the coils will be connected separately. This is done
to keep the potential between the bars down to a mini-
mum: that is. about 5 volts between bars of machines
not exceeding 110 volts, 10 volts between bars of ma-
chines not exceeding 220 volts. 15 volts between bars of
machines not exceeding 550 volts, etc. These differences
in potential apply to both series- and parallel-wound arma-
tures.
The series-wound armature is little different from the
parallel-wound armature except in the connections be-
tween the coils and the commutator bars.
A wave, or series, winding is sometimes called a two-
circuit winding, because it requires but two brushes (one
pair) and. as previously explained, there is but one divi-
sion of current for each negative brush, which is equal
to two paths, or circuits. To find the spread, or pitch, of
a coil in a series winding, apply the same rule as in the
parallel winding, but the value of Y can be any number
— odd, even, or a mixed number. Series windings are
.March 9. 1915
l> 0 W E B
337
divided into two classes, namely, single- and average-step
windings, depending on the value of Y. If )' is an odd
number the winding will be single-step, in which case Y
will equal the commutator pitch (the distance between
opposite ends of the same coil expressed in the number of
commutator bars). When }' is even it must lie made odd
try adding one hut the commutator pitch can have two
beginning of coil No. 2 in winding space '■'> in slot No. %,
Then spread coil No. 2 from space '■'> to 10 in slots 2
and 5. Table 2 indicates the number of the winding
space and the slots between which the coils will be wound.
The connections between the coils and the commutator
are made according hi the commutator pitch, which in
this problem can he cither ? or 8. as previously explained.
13 14 15 Coil No.
Fig. G. Illustrating Fig. 7. Illustrating
the Shout Pitch the Long Fitch
values, that is. it can have the original value of 1* or it
can equal the coil pitch, which was made an odd number,
as explained ; this is termed average-step winding. The
two values of the commutator pitch are called the "long"
and the "short" pitch. The short pitch is preferable
because it results in fewer crossings of leads from the
coils to the commutator. Fig', b' illustrates the use of
the short pitch in a four-pole series winding, showing
two coils in series between adjacent commutator bars
from right to left, and Fig. 7 shows the long pitch with
two coils in series between adjacent bars from left to
right.
If a series-wound armature has been connected accord-
ing to the short pitch and is reconnected with the long
pitch, it will reverse the direction of rotation of the
armature.
If the value of Y should result in a mixed number the
fraction is dropped. In a four-pole winding this can only
be i/£ : in a six-pole winding %, etc. By dropping the
fraction there will be an inactive coil, that is, one which
will not be connected to the commutator. This, however,
will occur only in the older types of armatures, for in
the modern designs this has been eliminated, there being
an odd number of coils in the winding. In any two-
circuit winding it is impossible to connect an even number
of coils.
For a practical example of a wave-, or series-wound
armature, consider one having 15 slots and 15 coils to be
placed in a four-pole machine. This will he a two-layer
winding, since there are as many coils as slots, and 15
commutator bars will be required. Then C = 15, P = 2,
and A = \, since only one pair of brushes is required
and there will be but one division of current.
Then
C ± A „ 15 ="= 1
A v 15
- = Y, or — ;
= 8 or 7
Using the minus value of A, as previously explained
(in parallel windings), Y = 7. Referring to Fig. 8, this
will spread coil No. 1 between winding spaces 1 and 8
(which is seven spaces from No. 1) and it will he located
in slots 1 and 4. To find the position of coil No. 2,
apply the formula Y ± 2 = Yf. Using the minus value
of 2, as explained for parallel windings, Yf = 5. Count-
ing 5 winding spaces back from No. 8 will bring the
Pig. 8. Wave Winding Based upon Data in Tabu, 2
Using the short pitch 7, the coils will be connected as
indicated in Table 3.
The spacing of the brushes in Fig. 8 is found by divid-
ing the number of commutator bars by the number of
poles; that is, 1.5 -r- 4 = 3% bars. By placing a nega-
tive brush on bar 1 and a positive brush 3% bars away,
which will be between bars 4 and 5, the direction of cur-
rABLE 3
Beginning of '-nil Xo.
1 t . bar No
1
End of .-am.
to bar No.
8
Beginning of coil No.
2 to bar No
2
End of same
to bar No.
9
Beginning of coil No.
3 to bai No
3
End of same to bar No
10
Beginning of coil No.
4 to bar No
4
End of same
to bar No.
11
Beginning of coil No.
5 to bar No
5
End of same to bar No.
12
Beginning of coil No.
6 to bar No
6
End of sam<
to bar No.
13
Beginning of coil No.
7 to bar No
7
End of same
to bar No.
l I
Beginning of coil No.
8 to bar No
8
End of same
to bar No.
15
Beginning of coil No.
9 to bar No
9
End of same
to bar No.
1
Beginning of coil No.
10 to bar No
1(1
End of same
to bar No.
Beginning of coil No.
11 to bar No
11
End of same
to bar No.
3
Beginning of coil No.
12 to bar No
12
End of same
to bar No.
4
Beginning of coil No.
13 to bar No
13
End of same
to bar No.
Beginning of coil No.
14 to bar No
14
End of same
to bar No.
6
Beginning of coil No.
15 to bar No
1.5
End of same
to bar No.
7
TABLE 4
Beginning of coil No.
1 to bar No.
1
End of same
to bar No.
9
Beginning of coil No,
2 to bar No.
2
End of same
to bar No.
10
Beginning of coil No.
3 to bar No.
3
End of same
to bai No.
11
Beginning of coil No.
4 to bar No.
4
End of same
to bar No.
12
Beginning of coil No.
5 to bar No.
5
End of same
to bar No.
13
Beginning of coil No.
6 to bar No.
6
End of same
to bar No.
14
Beginning of coil No.
7 to bar No.
7
End of same
to bar No.
15
Beginning of coil No.
8 to bar No.
8
End of same
to bar No.
1
Beginning of coil No.
9 to bar No.
9
End of same
to bar No.
Beginning of coil No.
10 to bar No.
10
Eml . f same
to bar No.
3
Beginning of coii No.
1 1 to bar No.
11
End of same
to bar No.
1
Beginning of coil No.
12 to bar No.
12
End of same
to bar No.
Beginning of coii No.
13 to bar No.
13
Ene of same
to bar No.
Beginning of coil No.
14 to bar No.
14
End of same
to bar Xo.
7
Beginning of coil No.
15 to bar No.
15
End of same
t.ri.ar No
8
rent through the winding will he as indicated by the
arrows. If the windings in Fig. 8 were connected ac-
cording to the long pitch, the connections would be made
as indicated in Table 4.
The brushes being set in the same position, the currenl
will he reversed, which would also reverse the direction
of rotation of the armature.
If the brushes were set as in Fig. 4, in relation to the
poles, the beginning of each coil would be connected
straight out from the slot to the commutator bar, and if
they were set as in Fig. 5, the beginning of each coil
would be swung a certain number of liars to the left (in
series windings only), this number being found by divid-
ing the number of commutator bars by twice the number
of poles.
In Fig. 8 the positive brushes are set across bars
4 and 5, and as there are as many coils in series
between adjacent bars as there are pairs of poles, there
S38
row B R
Vol. 41, No. 10
will be two coils in series. Therefore, there will be two
coils short-circuited — Nos. 5 and 12, winch are marked
with small circles.
The formulas employed in this article are somewhat
different from those found in textbooks, but they arrive
at the same results. A winder will always remember thai
the winding step Y must be an odd number, and that the
difference between any two adjacent coils must be two
winding spaces; also, before connecting the winding to
the commutator he will find out in which position the
brushes are going to be set. This will apply to both
series and parallel windings.
which were manipulated as necessary to get the desired
rate of flow as indicated by the pitometer. This method
of regulation permitted constant rates of flow to be
maintained, and the temporary isolation of the discharge
from the service lines gave the desired freedom from
surges which would otherwise have been present in the
mains.
At the Roseland Pumping Station, Chicago, two booster
pumps were recently installed to raise the pressure of
50 to 60 II).. normally carried in the water main, to a
maximum of 87 lb. (200 ft.) for the Washington Heights
section.
Each unit, as shown in Fig. 1, consists of a 14-in.
Worthington horizontal centrifugal pump direct-connected
to a 115-hp. Kerr turbine running at 2750 r.p.m., a
325-sq.ft. Worthington cylindrical shell waterworks type
surface condenser located in the suction next to the pump,
a 5.\l2x10-in. single vertical flywheel-type air pump with
attached hotwell pump, and a 4-in. automatic atmo-
spheric-exhaust valve. The main pumps are of the
single-stage, double-suction, screw impeller type with
volute casings, and the turbines are each controlled by
twn governors — a speed-regulating governor and a pres-
sure-regulating governor. The former is of the oil-relay
type and the latter of the Fisher type, designed to main-
tain a constant pressure in the mains regardless of any
fluctuations in either the capacity or the suction pressure.
Some of the principal dimensions are
as follows: Suction inlet of pump. 13
in. square; discharge outlet, 14 in.
diameter (corresponding to a velocity
of 714 ft. per sec.) ; steam inlet to
turbine, 2y2 in.; exhaust outlet, 12 in. :
condenser water outlet, 13 in. square.
and water inlet, 20 in. diameter. A
steam pressure of 170 lb. gage is car-
ried. The manufacturers gu tranteed
that each pumping unit would develop.
a duty of not less than (.7,000,000 ft.-
lb. per thousand pounds of steam at the
pressure stated, and not less than 98
per cent, quality when delivering at
the rate of 5,000,000 gal. of water per
24 hr. against a head of 85 ft. (not including friction
through the pump nor through the suction and discharge
piping as measured between the suction- and discharge-
pressure gages).
The acceptance tests were conducted by a board of
three engineers — one representing the City of Chicago,
one the contractor, and the third selected by the first two.
In order to vary the capacity and maintain the same
constant during each run. the discharge piping system
was isolated from the Washington Heights high-pressure
system and the water returned to the low-pressure system
through cross-over valves controlling the rate of flow.
A pitometer was installed about one mile west of the
station at a point convenient to the valves mentioned.
Fig. 1. One of the Booster Units
In accordance with the specifications, the quantity of
water pumped during the tests was mc.isured by a 30-in.
venturi meter, which is a part of the permanent equip-
ment of the pumping station. The air pump was oper-
ated condensing, and the condensate from it was weighed
along with the condensate from the main turbine.
The curves in Fig. 2 show the relation between head,
capacity and duty through the range covered by the
5 6 7
CopacH-y in Million Gallons per Z4- H ■-■■
Pig. 2. Curves Showing Performance of Pumps
tests, the dotted lines showing the probable performance
beyond this range.
The west pump showed a duty of 73,000,000 ft.-lb.
per 1000 lb. of steam, corrected to an initial pressure
of 170 lb. gage and 98 per cent, dry, and a capacity
of 5.120.000 gal. per 24 hr., thereby exceeding the guar-
anteed performance by 8.95 per cent, in duty and 2.4
per cent, in capacity.
The tests of the east pump, when operating against
the specified bead at 85 ft., showed an initial duty of
71.000,000 ft.-lb. per 1000 lb. of steam, corrected to the
initial conditions, and a capacity of 5,280,000 per 24 hr..
therein- exceeding the guaranteed performance by 5.97
per cent, in duty and 5.6 per cent, in capacity.
.March <), 1915
piiiiiuiiiiuiniiiiiiiiiiiii'iiiiiiiiiiiii mini
P U W E 11
n
Engineering
Few engineers are privileged to keep in touch with
the progress of laboratory and mathematical investigations
in different parte of the world, which affect power-plant
development and operation in indirect ways. The rea-
sons are that intense absorption in -practical" problem-
takes so much time and that research work is conducted
for long periods with little publicity because the follower
of pure science hesitates to give out results not well es-
tablished. It is a great mistake, however, to look upon
research as a subject of mainly speculative interest, for
out of experiments and studies often far removed from
matters of routine operation sometimes come develop-
ments ot immense engineering value.
In a lecture given recently at the Worcester (Mass.)
Polytechnic Institute, Professor Albert Kingsbury, in-
ventor of the thrust bearing associated with his name,
outlined the steps in lubrication research, extending over
many years, which led to the final development of this in-
teresting equipment. Without recounting the sequence of
events, it is of interest to note that the most delicate re-
sources of the physical laboratory were drawn upon in
measuring the axial eccentricity of a revolving piston fit-
ting closely in a cylinder in which the only lubrication
was provided by a film of air about one-thousandth of an
inch thick; in studying the wedge effect of rotation upon
the lubricant, and in comparing experimental observations
with the predictions of Reynolds, whose remarkable math-
ematical studies of bearing friction, published in the
"Transactions of the Philosophical Society of Great Brit-
am" as far back as Ism;, threw a flood of light upon many
phenomena of obscure explanation noted in the subsequent
tests.
The dependence of bearing friction upon -peed rather
than upon load under these condition.-, the practicability
of measuring pressure distribution at different points on
bearings by multiple gages of the mercury type, the check-
ing of piston displacement by a telephone receiver, set-
screw, battery and contact method, taking advantage of
the excellent insulation provide] by the minute -kin of
air between the piston and the cylinder, and the study
of tool-point lubrication by microscopic observation of
cuts in a running lathe, all bad a bearing upon the in-
vestigation which need not lie detailed here, but they serve
to point out that it is rash to limit the possibilities of
scientific method or to take it for granted thai because
a phenomenon in friction, thermodynamics or electricity
is obscure, it is beyond the reach of modern laboratory
apparatus. Few of us need to master the detailed calcu-
lations of Reynolds, Lord Kelvin and other savants in
the field of mechanical friction, but it is singular and in-
teresting that the experimental result- of Kingsbury were
so accurately forecasted by mathematical research, which,
however, in the case of Reynolds, made the mistake of sup-
posing that the minute quantities involved could not be
experimentally measured.
11111 ' '""»»» iiiiiiiiiiniiiiiiiiiiimimmmiiimimim inimmimmim minimi immimmimmiiiiiiiiiin
Each type of investigation thus supplemented the other,
and the two together ultimately brought forth a useful
form of equipment for commercial service, in which the
principles determined in investigations which might seem
largely theoretical were turned to account in the design
and construction of apparatus for power-plant applica-
tions. In a broad sense, the final research was a byproduct
of a study of the friction of screws— a point worth bearing
in mind in observing and recording collateral phenomena
in connection with any technical investigation.
A Skaggesfted A<cUvUy for tUe
JEimsfiinieeriiagf IF©tLainic
Few realize the prodigious rate at which additions are
G made to available engineering information. In the
first place, there are constantly appearing new branches
and ramifications to engineering. A half-century has de-
veloped electricity into a great industry with an extensive
literature, abstract and applied. In a quarter of a cen-
tury the internal-combustion engine has grown from a
driver of coffee mills to one of rolling mills. A couple
of decades has seen the evolution of the steam turbine
with all the consequent changes in power-plant apparatus
and design.
These in our own field: in other fields as great or
greater developments have taken place. And with all this,
in addition to the fund of knowledge which we have ac-
quired and are -till acquiring about the old things, come
voluminous contributions to current knowledge about the
new. Research laboratories are discovering; committees
are investigating and reporting; professors and post-
graduates are studying; inventors and developers and
manufacturers and users are finding out: professional so-
cieties are hunting all who have special information and
inducing them to add it to the general fund. The techni-
cal press has, for its reason for being, the production
and recording of such information. The specialist who a
lew years ago could get all the available information
about his subject in a few standard volumes, the proceed-
ings of a single society, anil perhaps a monthly magazine,
could now keep so busy reading about it that he would
have no time to pra< tice.
In the mass of engineering literature produced, tran-
sient as may be the interest of much, subject to criticism
and refutation as may be a great deal, duplicative and
ecu contradictory as may be some, there are recorded the
accumulated knowledge of and thought upon the subject.
If out of this, the material of permanent interest could
be put upon record in an orderly fashion, so that the
seeker for knowledge upon a particular phase of any en-
gineering subject could find it all together, what effort
and time and money would be saved to the delver for facts
already known and the traveler upon paths which have
been already demonstrated to lead into a dead end.
To what worthier purpose could the trustees of the En-
gineering Foundation so generously established by Am-
brose Swasey devote their initial activities than to the
340
P 0 W E R
Vol. 41, No. 10
development of some method of analyzing, classifying and
filing engineering information? With sufficient time and
talent, a system rould be evolved under which the period-
icals could print against the titles of articles of reference
value or even against individual paragraphs, numbers,
of the Dewey-decimal or other system, which would auto-
matically lead these articles or card-index references to
them into the right file. The principal reason that this
has not been already done is the want of a standard filing
system for engineering information.
This is the one engineering purpose in sight which is
broad enough to warrant the use of a fund designed "for
the advancement of engineering art and sciences in all
their branches, to the greatest good of the engineering
profession and to the benefit of mankind." And the mo-
tion by Henry Hess, in his discussion of the paper by Ed-
win J. Prindle, dealing with the classifying and indexing
of the records of the American Society of Mechanical
Engineers, to the effect that it be suggested as an object
of their interest and activity, should have been sustained.
One might as well not have a thing as to have it and
not know that he has it.
What better use could the means available be put to
than in taking stock of current engineering knowledge,
classifying and arranging it for ready reference, and or-
ganizing a system whereby new information would flow to
its appointed place as it develops ?
Asaaly^airag Station D©§ig»ini
The study of generating plant and substation designs
is instructive to any engineer. Even if an operating man
never expects to lay out a plant it pays him to scrutinize
the arrangement and composition of other installations
than his own, for it gives him a broader outlook upon local
problems and a sense of proportion which is a valuable as-
set. The more plants one visits, or studies through care-
fully prepared descriptions in the technical press and in
the transactions of engineering societies, the more appar-
ent it becomes that standardization in design is a long
way off, and fortunately so. Nearly every installation
has some peculiar feature of note, and it is always in-
teresting to weigh and compare the merits of different
ones.
A plant recently examined illustrates these points.
Situated in a deep valley above a small town, the station
is close to the edge of a cliff and utilizes a head of one-
hundred feet, with a maximum development of about
thirteen thousand horsepower in three direct-connected
generating units of modern design supplied with water
by. a pair of large penstocks leading to the wheels from
a dam a short distance above the station. The plant rep-
resents a gradual development which has been carried on
by its owners with great skill in view of the local diffi-
culties encountered. No criticism of these men is intended
in the following comments upon the layout in relation to
the latest ideas in hydro-electric development, which are
simply advanced to show the importance of viewing in-
stallations from the standpoint of trying to see wherein
they might be more efficiently arranged were the oppor-
tunity to build anew a Horded. In other words, it is
important to try to determine for oneself whether each
installation visited measures up to the most advanced
practice known to the visitor, and if not, to quietly study
wherein it appears to fall short. This does not mean any
failure to appreciate the good points of any layout or
to condemn a plant for a few apparent defects for which
its present owners and even its original designers may
not be responsible, for the art of station design advances
as do other affairs, and the best of today soon becomes
eclipsed by the practice of tomorrow.
In the case selected, there are industrial plants on the
river in the town which utilize eighty feet of additional
fall in scattered wheels with both mechanical and electric
drives. If the development were to be made today, the
existing hydro-electric plant would not be built, but in-
stead, a tunnel would be driven through the hill on one
side of the town to the river over one hundred and eighty
feet below on the other side of the barrier, and the entire
development would be on the basis of utilizing maximum
head in concentrated generating units. This would be
bold compared with the ideas of the builders of the ex-
isting station, but this is the day of bold conceptions in
engineering.
Close scrutiny of the present plant indicates the desir-
ability of building a straight operating room free from
angles, so that the switchboard can be seen from all
points ; of bringing the water into the wheels in penstocks
which do not obstruct the view in the operating room and
the movement of a high-powered traveling crane from end
to end; of placing the switchboard where the shortest
possible cable runs from the generators will be required
that are consistent with good visual control of main units;
of providing ample space for oil switches in outgoing lines
and straightway runs for high-tension wiring; of plac-
ing the chief engineer's office in a commanding position
in relation to the operating room instead of in a distant
wing of the building without visual connection to the lat-
ter; and of avoiding unnecessary complications in high-
tension bus and switching arrangements for the sake of
a flexibility in operation seldom required in actual ser-
vice.
Bearing in mind that the design of any station upon
which good engineering is expended is more or less of a
compromise, it is none the less true that critical examina-
tion of such installations pays well for the time and
trouble put upon the work, provided at every point effort
i- made to formulate constructive and not merely captious
criticisms.
That our insistence upon the danger of the breathing
head is warranted is again attested by another failure of
this sort, this time of a bumped head on a Stirling boiler
in New Bedford. Fortunately, the defect was discovered
before an explosion or serious damage occurred.
March 9, 1915
P 0 W E B
341
©inresipoinidleini©*
niiiiiiiiiiiiiiiuiiim mm 1 1 Ml mmm
11111 :: ' "I Nil ,i
Usairag Grs&pMtle lira B©nfl©s=s*
Mr. Weaver's letter in the Jan. 36 issue on the use of
graphite reminded me of nn experience with it in two
or three plants. One plant had three 100-hp. locomotive-
type boilers which were heavily scaled. After washing, I
put 10 lb. of graphite into each boiler and then fed i/T'b.
every twenty-four hours. In three months our boilers
were free from scale, and in less than eight months from
the date of beginning the use of graphite we had saved
about $80 on the coal bill.
It seems to me that engineers expect graphite to act
too quickly. It should be remembered that the graphite
must get between the scale and the boiler shell and work
the scale off by mechanical means. By feeding the graph-
ite in the manner mentioned, a total of 160 lb. of hard
scale was removed from a boiler in less than 70 days.
G. A. Bennett.
Denver, Colo.
Mr. Weaver's experience with graphite as a scale re-
mover coincides with mine. I find that graphite and a
good mechanical tube cleaner go together. The graphite
will soften and loosen the scale and make it easier" for the
mechanical cleaner to bring it down in either a water-
tube or fire-tube boiler. If a boiler is badly scaled it is
slow and hard work to get the scale off even after the
graphite has loosened it, but the cleaner will break it up
and quicken the process of removal.
A. A. Blanchard.
Oxford, N. J.
niiiiiiiiiiiiiiiiiiniiiiii n iiiiiiiiiiiiiiiiiiiiiiniii {ll i
Pasffivpeirs
s>s@
The municipal water-works here has four vertical water-
tube boilers of 450 hp. each. While the load seldom re-
quires the operation of more than one boiler at a time,
two are always under steam in order to provide service
in case anything should happen to either boiler. This
precaution is necessary, as the pumping engines operate
on the Holly system without reservoirs.
During night loads it is advisable to bank one of the
boilers. This had been tried on one pair of boilers with
fair success. The other pair, however, could not be prop-
erly banked. Examination showed that the dampers
stuck on the bottom while at the tops they were open as
niueh as four inches. Each boiler has three damper pad-
dles operated on one stem. At one time a strip had been
cut from the bottom of a paddle to increase the clearance.
This merely aggravated the trouble. Later the center
paddle had been tied to the outer ones by straps which
[Sightly bettered conditions.
As this failed to give satisfaction, further examina-
tion showed that the stem was bearing at the ends
only, the center supports being over the notch for taking
out the dampers, and apparently in upside down. The
weight of the moving parts caused the damper to settle,
8trike the bottom first and prevent the top from closing.
•See "Power," Tan. 6. Mar. 3 and 31, and Apr. 7, 1914.
The more that was chipped off the bottom, the lower the
damper sank. The result was inefficient operation when
this bank of boilers was in use and a poorer draft when
the other bank was on duty, as both are attached to the
same stack.
The trouble was remedied by placing a small support
under each of the centers between the paddles, thus keep-
in- the bottoms free. The stack now has a much better
chance to operate at full efficiency. How much coal went
Proper Open Position
Support Upside Down
Actual open position
due to no center
support
Arrangement of the Damper
up the chimney since the boilers were installed is proble-
matical. What we do know is that since April, when
the station was taken over, the coal consumption has de-
creased 30 per cent, and the pumps run much slower, in
spite of the fact that our meters are reporting more
water consumed.
H. C. Wight.
Dayton, Ohio.
m
Vacuus mm
In reviewing the many references to the effect of high
vacuum on reciprocating engines which have appeared
in a long series of volumes of Power, I have been im-
pressed with the omission of consideration of the change-
able temperature of condensing water throughout the
year. Again and again the disadvantage of larger con-
densing apparatus, with its resulting high cost, is set
down against the gain due to high vacuum, when any
such gain is acknowledged at all. I have yet to see a
single instance where the question is considered as to
whether during the winter time (when high vacuum is
available, inasmuch as cool entrance circulating water
or injection water makes it so) it is desirable to have
air-pumping apparatus of the requisite design and in
a requisite state of maintenance, to make the potential-
ly available high vacuum actually existent.
It is, of course, only in recent years that any serious
opposition has appeared to the old view that 35 in. or
342
POWER
Vol. 41, Xo. 10
slightly more represented the most economical vacuum
for reciprocating-engine service — an argument apparent-
ly based on the widest experience in the days when it
was customary for the hotwell water to be used as feed
water without subsequent heating with the exhaust steam
from independently driven auxiliaries. When this long
accepted conclusion began to be questioned there re-
mained a strange absence of any consideration of the
possible desirability of keeping the condensing apparatus
of moderate size, so that during summer weather only
moderate vacuum could possibly be attained, but uti-
lizing steadily increasing vacuum as condensing water
becomes colder from summer to winter.
Utilization of this scheme necessitates air-removing
apparatus of the best possible operating characteristics.
But such apparatus is relatively inexpensive when it
represents dry-vacuum pumps used with surface con-
densers and still less expensive when it represents mere
modernized design of jet condensers of the barometric
Hi- equivalent form. Why has it not become recognized
that a condensing-engine equipment is not installed, and
should not be thought of as installed, to maintain some
definite and constant vacuum throughout the year,
whether it be 2(> or 28 in. or more, but as installed is
capable of maintaining a certain vacuum in summer and
a much higher vacuum in winter, and is to be so operated
throughout the year as to maintain as nearly as possible
a constant vacuum efficiency referred to the changing
vacuum available?
H. L. H. Smith..
Brooklyn, X. Y.
iBjmg (iaS'Q'asinvel
Several years ago. while operating a substation. I had
a peculiar experience with a large booster set used for
charging a storage battery ami boosting one of the long
feeders. The system was Edison three-wire with the
neutral grounded : 230 volts across the outside wires and
115 volts to the neutral.
The switches on the high-tension side of the system
were remote-controlled, and to operate these, as well as
the protective devices on the different units a separate
operating busbar was connected across the positive main
busbar and the neutral. Fig. 1 shows the connections
of the booster and operating busbar.
The first indications of trouble occurred one Sunday,
when one of the attendants received a shock while clean-
ing the booster. Everything on the switchboard was
apparently as it should be, so I touched the machine rather
gingerly in several places, to see if 1 could repeat the per-
formance, but without resiilt>. With a test lamp I then
tested every conceivable place and finally went over the
machine with the portable voltmeter, without finding
anything wrong.
Everything won along all right for a couple of weeks,
when, on Sunday, while making an insulation test the
chief found the operating busbar grounded and told me
to locate the trouble. To my surprise the operating
busbar tested clear, whereupon I decided that the chief
had been mistaken and told him so the next day. lie
maintained, however, that the busbar was "rounded when
in- tested it .
Two days later the chwf received a jolt from the com-
mutator of the booster, lie was too busy at the time to
investigate, but instructed me to do so. Again everything
tested clear, only to be followed by the night man re-
ceiving a shock from the same machine.
This was getting to be a joke, so I connected a lamp
between the frame of the machine and a water pipe to
make a ground and placed the lamp directly above the
desk so that anyone would be sure to see it in case ;t
should light, for the instant the machine became ground-
ed on either side, the current would rlow through the
lamp to ground and back to neutral.
One evening, while I was sitting at the desk the light
suddenly (lashed in my face. I grabbed the test lamp
and tested from the positive booster-generator to the
frame, but without results. When I applied the test lamp
to the negative booster-generator and the frame the lamp
lighted up brilliantly. I disconnected the machine from
every possible source of potential, even from the operat-
ing busbar connections to the speed-limit device, but the
lamp burned as brightly as ever. I finally gave up in
disgust and sat down to think it over, when suddenly
the light went out.
Nobody was near the machine at the time, but the
assistant was just switching oil' the lights over the booster
.? ggsAgr
Fig. 1. Booster
Connections
Fig. 2. Speed-
Limit Device
set. There was a light over each of the four bearings.
These were run in conduits up alongside of each bearing
pedestal and clamped to it. I had the lights switched
on and, sure enough, the lamp over the desk lighted up
again.
One of the light sockets was broken, so this was re-
placed and the light over the desk stayed out with the
machine lights on. I decided that the trouble had been
located, concluding that, due to the broken socket, the
lighting circuit had been grounded intermittently on
the machine.
Two days later, while cleaning the commutator on the
negative generator I received a jolt that made me jump.
One hand was on the frame at the time, and the other
happened to touch one of the brush-holders. The lamp
was connected again and lighted up as before. The lights
over the machine were out at the time, so it was con-
eluded that they could not be the cause.
A few nights later the night operator again received
a jolt from the machine, and at the same time the signal
lamp indicated; but he was unable to find anything
wrong.
One Sunday, shortly after this. I was sitting at the
desk when the light suddenly Hashed. The assistant was
around the machine at the time and at that particular
instant was wiping the end of the bearing and the inside
March 9, 1915
P 0 W E R
343
of the hood over the speed-limit device. I had him go
over it again and the signal lamp went out. Evidently
the trouble was in the speed-limit device.
Fig. 2 illustrates the construction of this device, in
■which X represents the contact points or clips of the
switch, C is the switch blade hinged on a pin screwed
into the main bearing, and D is a weight hinged on a
pin fastened to the shaft and revolving with it. Centrifu-
gal force tends to throw this out when the shaft rotates,
u ii i i 1 at the predetermined speed it strikes the switch
blade C, closing the circuit and tripping the circuit-
breaker. The tripping speed is regulated by adjusting
the tension of the small spring .s'. It was the switch
C that caused all the trouble, for it was not insulated
from the pin on which it was hinged ; consequently, when
the switch closed it grounded the machine.
To complicate matters the switch worked rather stiffly
and made contact with one clip before touching the other.
In wiping the machine the operator moved the blade C
just enough to make it touch one clip without closing
the switch, which would have tripped the circuit-breaker.
This grounded the machine. Sometimes, clue to the
jarring of the machine. C would drop down again, or
it would stay up until the next time the operator wiped
it or sometimes for several days. With the signal lamp
connected from the mac-bine to ground, this also grounded
the operating busbar.
"What made the matter still more puzzling was the fact
that the lighting circuit was grounded on the machine
at the same time. To remedy the trouble we bored out
the hole in C and put in a fiber bushing.
Thomas G. Thukston.
Chicago, 111.
A circular issued by the Bureau of Standards points
out that at present there is no accepted authoritative defi-
nition of horsepower and, therefore, different equivalents
of this unit in watts are given by various books. They
state that inasmuch as the horsepower is a gravitational
unit of power, it varies with latitude and altitude, being
552 ft. -Ih. per sec. at the Equator and 549 ft. -lb. per sec. at
the North Pole. They recommend the adoption of the
horsepower as 550 ft.-lb. per sec at 50 latitude (approxi
mately that of London) and sea level and that the equiva-
lent in watts be taken as ; 16.
There are too many engineering quantities for which
there are no exact definitions, and it is to be hoped that
the engineering societies will adopt standard values. The
engineering congress to be held at San Francisco this fall
would afford a line opportunity to settle this and several
other values, such as the British thermal unit.
While the writer believes in exact definitions for engi-
neering quantities, be is of the opinion that the Bureau of
Standards has over-estimated the commercial importance
of the variation of the horsepower with latitude and alti-
tude. It claims that this variation is enough to be or
commercial importance and should be taken account of in
engineering tests. The greatest error that could occur
due to a variation in latitude and altitude is % of 1 per
cent. Practically the only tests made at the present time
are to determine the water rate either per indicated horse-
power or per brake horsepower.
In the first case the error of the indicator is easily 1
per cent, and the personal error in working up the card
can hardly be less than 1 per cent. Other variables, scich as
weighing the water, etc., will affect the result, so that any
engine test can hardly be guaranteed to within 2 to •'!
per cent. This would also be true when measuring brake
horsepower. It would hardly seem worth while to take into
account a variation of less than % of 1 per cent., when
the known error is four to six times as much. This is on
a par with boiler tests published from time to time, in
which the results are carried out to the fourth and fifth
places.
Another quantity which has even more effect on the
water rate per horsepower with different altitudes than
gravity is the pressure of the atmosphere. Yet the
writer thinks that the decrease in hack pressure with in-
crease in altitude is not considered of sufficient commercial
importance to be taken account of.
W. I j. DlJRAND.
Brooklyn, N Y.
[Of interest in connection with this letter is the edi-
torial, "The Kilowatt and the Horsepower," on page 720
of the Nov. 17, 1914, issue. — Editor.]
■48
H<o>s!m©=Mgidle FeedUWsiftes3 Meatteif
The criticism by E. H. Pearce in the issue of Dec. 8,
1914, on pace .SHI, of the total result obtained from a feed-
water heater which I described on page 502, Oct. 6, 1914,
is entirely just. What I neglected to say was that
the first heater gave such satisfactory results that five
more were made, some of which were larger than the one
described. I regrei the blunder very much.
Samuel L. Robinson.
Providence, R. I.
v
PiPolbsilbS© (Ca^s© ©if ISon!©!?
L©st©B&§
Referring to the tabulated list in your issue of dan. 26
of boiler explosions which occurred during the first half of
1914 and your editorial comment thereon that "these
statements (of the probable cause) are not always as full
and satisfactory as might be desired" is very true.
Tube failures and other conditions found after the ex-
plosions are not the true causes thereof, but are rather the
results of conditions for which the tubes should not be
held responsible, such as the nature of the feed water —
too hard, containing mineral salts and other scale-form
ing constituents, suspended insoluble matter, or oil which
was not filtered out. In the last case, boilers tubes of
all kinds are apt to suffer, no matter how excellent they
may have been when first put into the boiler.
It has been stated by Messrs. Stromeyer and Barron
in a paper before the Society of Naval Engineers of Gr at
Britain, that % in. of scale will raise the temperature
of a boiler plate 300 dee. \-\t whereas less than 0.001 in.
of oil will produce a far worse effect. They also state that
the effect of oil is intensified where scale is present, there-
fore no effort should be spared to keep it out of boilers, not
only when slight quantities are found floating on the sur-
face of the feed water, but particularly when the oil is in
the so called emulsified condition, as indicated by a cloudy
appearance of the water.
344
P 0 \Y E R
Vol. 41, No. 10
There are many and adequate systems now in use to
render hard and scale-forming water practically harmless.
and also processes which remove every trace of oil from
feed water, so that there is no good reason why boilers
should be fed with poor water, which is the source of
most boiler troubles and serious accidents.
It is to be hoped that state or Federal control will be
made more strict in regard to the details gathered relat-
ing to boiler explosions, so that no particulars which
might throw light upon the true causes of such disasters
can be withheld from publicity.
A. E. Krause.
New York City.
His basement separator cannot be given that much
fall, but the one on the first floor can be arranged with
the seal in the cellar instead of as located, and then it will
work. Then he should take the exhaust from the engine
in the basement and put it into the heating line at a point
near where the other separator enters, moving the base-
ment separator up there, so as to get enough fall to take
care of it with a seal in the cellar. I have shown this in
a sketch, using only one seal of larger capacity. Perhaps
a separate seal for each would be more satisfactory, es-
pecially if the separators should be of different patterns
or if the piping areas are restricted.
W. F. Meinzer.
Brooklyn, N. Y.
Referring to Mr. Goodwin's trouble with the oil sep-
arator described on page 207 of the Feb. 9 issue, as I have
experienced similar trouble and overcame it successfully, I
offer him a solution as per the following sketch.
He states that he carries eight inches of vacuum on
his heating system. This will sustain a column of water
about eight feet high in the pipes leading from his oil
Heating Si/ stem
Remedy Suggested for Trouble with Oil Separator
separators, and he should have at least that amount of fall
from the bottom of his separator to the top of any seal
that he uses. He does not state whether he ever has any
pressure above atmosphere, and I take it for granted that
he has, so he will need some seal to prevent steam blowing
to the atmosphere when such is the case. His sketch
shows only sixteen inches of head in one case and prac-
tically none in the other.
If he can get no more fall than he shows, it will lie bet-
ter to remove the seals entirely and run a line direct to the
seweT with a swing check valve on as low down as possible,
i pening toward the atmosphere. This will give a head of
water over the check to open it against atmospheric pres-
sure, and the check will prevent entrance of air into. the
system. If he carries a pressure above atmosphere the
addition of a steam trap id' large capacity will prevent
the loss of steam.
Referring to Mr. Goodwin's inquiry in the Feb. !) issue
regarding trouble with oil separators, the heating system
is carrying eight inches of vacuum, which means that a
head equivalent to eight inches of mercury, or about eight
feet of water, must be carried on the separator side of the
seal before the oily drips will overflow the seal.
From the sketch it is evident that the seals are set too
close to the separators. My advice would be to run both
drips together into a ^-in. lifting trap of the tilting
type. When the trap dumps it will cut off the inlet and,
consequently, the vacuum of the heating- system, allow-
ing the trap to discharge by gravity.
W. L. Dl'RAXD.
Brooklyn, N. Y.
Referring to H. G. Goodwin's letter in the Feb. 9
i: sue concerning "Trouble with Oil Separators," it is sug-
gested that the drip loop in connection with the larger
separator should be dropped at least 4 ft. so as to give suf-
ficient head in case of vacuum in the exhaust system, and
a V^-in. vent inserted in the top of the last leg of this
loop, and a check valve placed at the discharge end near
the connection to the waste line. In reference to the
smaller separator, it is suggested that the seal loop be
replaced with some form of "grease trap" with a check on
the discharge side.
Charles A. Nelson.
Chicago, 111.
The oil chain in the outboard bearing on a new gas en-
gine gave much trouble when the engine was first put in
service, by stopping and allowing the bearing to get
warm unless it was noticed in time and started again be-
fore the hearing was dry.
The cap was removed and the chain run around by
hand. One joint between two links was rather still', but
aside from this, there was apparently nothing wrong.
The joint was limbered up, the cap replaced, and the en-
gine started again, but before the week was out it was as
bad as ever.
Upon a closer examination, the chain was found to be
dragging on the bottom of the oil well. Three or four
links were taken out, making the chain just long enough
to clear the bottom nicely, which entirely eliminated the
trouble.
Eabl Pagett.
Coll'cyville, Kan.
.Manh 9, 1915
Safety
row e i:
345
Now that New York City has a law making it com-
pulsory alter a few months to have elevators provided
with safety devices on gates or doors, discussion in Poweb
as to the working of these would he welcome. Several
buildings m Xew York have such devices.
In the building where I am employed there is an elec-
tro-mechanical -ate lock which lias worked well for the
last tour years. The elevator cannot be started unless all
gates in the shaft are closed tightly. When a gate is
open a magnet placed over the operating valve (hydraulic
car) is energized and, through an arm connected to the
lever of the valve, prevents the latter from being moved
by reason of the lever being held rigid. To bring out
the relative merits of different devices for this service
I hope discussion will be forthcoming.
AT , at t 3 W- T- OSBOKX.
.Newark, N. J.
[ Xew York City lias no such law. A proposed ordi-
nance making the use of such devices compulsory ami
calling -lor the inspection of all elevators in the city was
presented before the aldermen some time ago, but that
body lias not yet acted on it.— Editor. 1
StisnMlainig SmmaM M©t©ips
W. S. Grimscom's diagnosis of the trouble experienced
in starting a small shunt motor without a starting box
when changed from driving a bottle-washing machine
to driving a jig saw, referred to in his letter in the Jan
12 issue, is quite correct, although he might have overcome
the difficulty by shifting the brushes. The decrease in
the starting torque was caused by the excessive current
m the armature which set up a very strong magnetizing
force from the neutral points of the armature across the
polepieces.
The current in the armature of a direct-current ma-
chine produces magnetic poles at the neutral points which
cross-magnetize the main poles, weakening the pole tip
back of the neutral point and strengthening the one in
front the degree to which the polepieces are weakened
and strengthened depending up,,., the position of the
brushes. If the brushes are set slightly in front of the
neutral point one is about equal to the other, but if set
back of the neutral point the pole tip back of the neutral
will be weakened faster than the one in front ,< strength-
ened, resulting in a decrease in the field strength This
accounts tor the increase in speed of a motor by shifting
the position of the brushes backward around the commuta-
tor against the direction of rotation. This shifting of
the brushes, however, is limited by the sparking at the
commutator. B
The brushes may be sel far enough back of the neutral
point to cause no ,11 effects under normal working con-
ditions, but when subject to an extreme overload current
as in Mr. Gnscom's case, the distorting effect may be
peat enough to weaken the motor or even cause the
armature to develop a backward torque.
Mr. Griscom could have remedied his trouble by riving
the brushes a forward lead, thus causing the armature
••urrent to strengthen the polepieces instead of weaken-
ing them. He could also have improved his lamp start-
Big device by short-circuiting it with a single-pole -witch
■f1*!. ""' ,""""' Qad '" accelerated. Furthermore a
starting bo* could have been secured for this purpose
'"lately the cos! of the lamps and fittings not
to mention the more satisfactory operation of the driven
machine when running under the proper conditions For
a temporary starting device a water rheostal could be
U7L :""1 this could be made to give as satisfactory re-
sults, as far as starting is concern,, I. a- a starting box
., rhe Practice of starting .hunt motors by connecting
tt«««» Erectly across the line is no, to be encot
except m the case of small, slow-speed machines up to
about 14 hp. running at a speed not exceeding T50 r.pm
and starting under very light load. If there is liability
of the load stalling the motor while starting, a start,,,:,
box should be used, even under these conditions. In a
great many cases where trouble is experience,! in the
operation of small motors it is from no other cause than
improper starting. In small series and compound motor.
the above rule need not be so rigidly followed, for the
series held winding helps choke down the starting
current, and as the current increases in the armature
it a so increases in the series field winding, causing a
much greater increase in the starting torque than in the
shunt machine, which will accelerate the load more rapidlv
than is possible with a shunt motor.
xT ,. . _. A. A. Fredericks.
-New York City.
m
In reading the article. ".Selecting a Pump for General
Service by Charles L. Hubbard, m the Feb. 9 issue
I was disappointed at not finding more helpful informa-
tion „r suggestions, and more so in discovering a real lack
men? °Wledge aud a tendency to erroneous state-
It is stated that direct-acting steam pumps, engine-
and turbine-driven plunger pumps and centrifugal pumps
are adapted to conditions where the friction head in the
suction pipe plus the elevation does not exceed fifteen
to eighteen feet. Should it not be mentioned that a
centrihura pump is not as well adapted where there is
a suction head. For it must be -primed" before it will
pump water? Sometimes this is a comparatively easy
operation but often it is not. The various method- of
Pnming a centrifugal pump might be stated, for
certainly the availability of some method of priming
night be a deciding factor in the selection of a cen-
trifugal pump.
If the water supply of a power house must be pumped,
the distance between the pump and the power house is
hardly the only consideration when choosing the tvne
"f Pump or determining whether to convey steam from 'the
boiler house to the pump or -to drive the pump by an
electric motor or gasoline engine" or "to install and care
tor a special boiler."
In pumping water from artesian wells the air lift is
often desirable, but not "to increase the flow" The
normal flow of a well cannot be materially increased by
""■v method "' Pumping, and the air lift is QOt the tvne
"I pump winch will always give a maximum delivery from
a given-sized hole.
Mr. Hubbard says that •••deep-well pumps have an
efficiency 0 40 to 50 per cent, and a slippage of 10 to
15 I"'1' cent T «ave used several double-acting deep-
346
F O W E R
Vol. 41. No. 10
well pumps which showed an efficiency of over 80 per cent,
and had no slip whatever. Moreover, these pumps de-
livered much more water from the well than we could
possibly obtain with an air-lift pump.
The statements regarding centrifugal pumps show a
surprising lack of knowledge concerning this type, which
is so widely used. Their efficiency is given as from 60
to 80 per cent, for the better types, working under the
conditions for which they were designed. But. he says.
"it is not possible to obtain as high an efficiency as with
the best design of piston pumps when the latter are kept
in first-class condition.'" The efficiency of direct-acting
piston pumps is given as from 65 to 75 per cent, and
of triplex pumps as from 60 to 80 per cent. According
to the figures given, the efficiencies of all three types are
remarkably similar.
The statement that •"turbine pumps are designed for
high lifts and are usually compounded in order to reduce
the peripheral velocity and thus reduce the friction"' is
beyond my comprehension. Evidently, the design which
characterizes volute and turbine pumps is not (dear to
Mr. Hubbard, nor is the reason for compounding, as he
calls it. High heads require multi-stage pumps, ami
compounding does not necessarily decrease friction.
L. B. Lext.
Brewster. X. Y.
:*:
Vmcoa^unnm Mesittiiimg wMIh\©^a&
In an article on ""Vacuum Heating without Thermo-
stats," by E. F. Henry, in Power of Oct. 50. 1914, the
nithor states that "provision is always made for inject-
ing water into the return pipe, so that the pump will not
attempt to pump steam."" This is a rather broad state-
ment, ami in this connection the writer wishes to say
that if the ''raps on the radiators leak steam, then it i-
necessary to have jet water at the vacuum pump. How-
ever, if a pro lerly constructed thermostatic trap is used —
and there arc such to be had — the necessity for jet water
is obviated.
In the article referred to it appears as if the author has
the idea that thermostatic traps are altogether imprac-
tical. The writer can cite a vacuum installation where
the radiators are twenty-odd Eeet below the vacuum pump,
yet the condensation from these radiators is lifted to the
pump without the use of jet water. Attention is called
to the fact that a twenty-foot lift, including friction in
die piping, would correspond to a vacuum of approximate-
ly IS in. At this pressure, water boils at KO deg. P.,
approximately. This should reveal the fact that, in case
any leakage occurred, the lilting of the condensation
would lie impossible, since the vacuum line would be
quickly filled with steam. The writer can refer to many
.aeiium systems of heating where no jet water is being
used, ami where the vacuum pump is quite aide to produce
a vacuum of from 8 to 1") in.
Mr. Henry i^ quite right in saying that in some cases
a thermostat has been removed without materially affect-
ing the operation of the system. However, in such in-
stances the radiator from whose trap the thermostat has
been removed must lie located at quite a distance from
the vacuum pump, or at a point when' the vacuum is
low and the discharge from the radiator has ample oppor-
tunity to cool before coming to a portion of the return
line where a higher vacuum is carried, and even then,
trouble is likely to occur.
Theoretically speaking, the substitution of globe valves
for the thermostatic trap at the return end of the radia-
tor might work very well, but from a practical stand-
point it will be almost impossible to throttle the return
from each radiator so that it will allow only the con-
densation to pass, especially since then' is no means of
telling just the amount of openings that would be ob-
tained by turning valve handles each a certain distance,
because different valves would give different opening-.
Besides the uncertainty of valve opening it must be re-
membered that condensation in a radiator may be in-
creased at times as much as 100 per cent, or on the other
hand may be so much reduced as to allow steam to blow
through. The use of jet water at the pump may pre-
vent the pump from pumping steam, but in such a case
the steam is in the return line, up to the point where
the jet water enters. In such cases one of the main ad-
vantages of a vacuum system is curtailed, to say nothing
of the complications usually brought about by the use
of jet water, which destroys steam, and it is generally also
the case that surplus water has to be discharged from the
system.
D. X. Ckostiiwait. Jr.
Marshalltown. Iowa.
We are given to understand by E. F. Henry's statements
under '"Vacuum Heating Without Thermostats" that he
refers to all types of vacuum return valves, although it
should be borne in mind that the term '"thermostatic"
would be more proper, and then strictly correct only
when applied to those valves which operate by the expan-
sion of a volatile liquid inside a disk, as distinguished
from the float type of valves. His reference to the virtue
of the vacuum system as means of abstracting more heat
from the steam "before it is thrown away" must be in-
tended to apply only to the use of exhaust steam.
The scheme Mr. Henry proposes has been employed
satisfactorily on gravity systems with the return open to
tlie atmosphere and no pump. This is similar to the so
called vapor system. With this system, however, a special
valve is used that can be shut off and so set. that when it
is wide open only the right quantity of steam is admitted
to the radiator. This scheme could also be used with a
vacuum pump on the return line, provided the difference
between the supply and return were always the same —
a condition that would lie impossible to maintain in
practice and would immediately be upset by the least
change in either the steam pressure or the vacuum in the
return.
With hot-blast heaters, where the rate of condensation
changes with every variation of the outside temperature.
the scheme would be impractical.
If globe valves are used on the radiators, as suggested,
another disadvantage would be that the heating unit-;
could never be shut off unless two valves were used.
Taking all points into consideration, T would not
advise any engineer to install a heating system and put a
vacuum pump on the return line and use n0 vacuum
valves: neither would I advise changing over an existing
system with the sole idea of a large saving in operating
cost, for there will lie none.
W. L. Dukand.
Brooklyn, X. V.
March 9, 1915
P O W E R
347
^lecfopic°ILii!R]h^
©s
When electric plants first came into use they furnished
current for lighting purposes only, and their total cost
of doing business was, therefore, charged up to the cur-
rent sold for this purpose. It did not take long to learn
that if the same equipment which was installed to provide
for light customers could be operating in the daytime,
they could afford to sell current cheaper during the day
than at night, provided they could continue to charge the
cost of doing business up to the light customers. This
Led to the conception and final birth of the present rate-
making "theories."
What citizen or court would permit a street railway to
charge a passenger riding on a car during rush hours a
fare several times larger than that charged at other
times of the day? Can you justly ask a street-ear com-
pany to charge less for a ride in an owl car just because
the load in the power plant at that time is in the valley
of the load curve, ami because they might to be glad to
have "even a little revenue during that time"?
The electric-light companies seek to show that they
are the one exception and that they should he allowed to
charge up a greater proportion of their cost of doing bus-
iness to the small consumer who cannot "kick back," and
a lesser proportion to the larger customer who can.
F. F. Chandler.
Indianapolis, Ind.
VilbiPSiftaoirtv Dsme ft© Mnsslinigl BEsidles
We have in our plant a 100-hp. impulse single-stage
turbine running 12,000 r.p.m. The wheel is 24 in. diam-
eter and mounted on a shaft whose diameter is % in.
There are 196 blades on the wheel and the peripheral ve-
locity is, as usual, quite high, being 1256 ft. per second.
An examination of the turbine to discover the cause
of excessive vibrations of the shaft showed a gap in the
rim where four blades had broken off (Fig. 1). Wheels
running at this high speed must be perfectly balanced.
The loss of a single blade will cause noticeable shaft vi-
brations.
The blades of these single-stage turbines are made wiai
bulb-shaped shanks which fit into slots in the rim of
the disk. The outer ends of the blades are hanged to
Fig. l.
Turbine Wheel, Single-Stage, Unbalanced
by Loss of Fotjb Blades
Fig. 2. Section of Blading
form a continuous rim of metal (Fig. 2). No special
apparatus is needed in replacing the blades. In this
case the wheel and shaft were removed from their bear-
ings, the shanks of the broken blades punched out and
new blades inserted by driving in from the side. The
Sanges were then filed true.
.Moisture in the steam, small particles of scale, etc.,
are probably responsible for the breakage. There is no
separator in the steam line, though one should be put
there.
R. S. Hawley.
Golden. Colo.
ss
The direful consequences of blocking up a Corliss engine
governor have been so often impressed upon our minds
that, with many of us, the faculty of reasoning whether
the practice is always hazardous has either never been
allowed to awaken or has been quickly inhibited at its in-
ception. The opinion is prevalent that no argument, how-
ever reasonable, can justify this practice, and that even to
discuss it on the negative side is in itself criminal. Yet
there is scarcely any danger — I do not say peril — that
cannot be risked with impunity at some opportune time,
and certainly there e i conditions under which the gov-
ernors may he blocked i ] with comparative if not com-
plete safety. In case of huge engines operating under
fluctuating load- it i> ;< dei ideil advantage in economy.
Engineers employed in treet-railway plants know that,
during certain pei'ods < f th< day, when the peak loads are
reached, it is some'.) aes necessary to prevent the governor
weights from droppin bel n the point of maximum cut-
off by fastening up the starting pin. Judging from many
an attendant's apprehension at that particular time.
however, few seemingly understand that the breaking of
a governor bell on one out of two or more engines driv-
ing generators c ected to the same set of busbars will
he attended with little if any c il consequences. Even in
industrial plants, in which tv. > or more engines are con-
348
PC) W E i;
Vol. H. No. 10
nected mechanically by means of the factory shafting,
the danger is slight provided (and here i- where reason
and common sense enter) the load is. while the pin is up,
at all times equal to, or greater than, the full-load capac-
ity of the largest engine then in operation.
The ease is similar to two horses drawing a loaded
wagon. One of them may lie fresh and impatient, smart-
ing under the restraint of its harness. It prances, jerks
and endeavors to rue away with the load, but finds it be-
yond its strength to do so and therefore it i> forced to fol-
low the gait of its more conservative brother. Suppose
Common Flyball Governob
two engines operating under similar conditions of heavy
load, and suppose that the governor belt on one breaks
when the starting pin is up. What will happen? Simply
tins, the other engine will obligingly give the unrestrained
one all the load it can take and the latter is immediately
forced to adopt the speed of the other engine. It really
due- not matter whether the governor revolves when the
load is so heavy as to bring the weights down on the start-
ing pin.
To sum up. my point is that under conditions as stated
an engineer may attend to his ordinary duties with as lit-
tle concern about his engine- a- at any other period of the
day. and my only justification for so elaborately enunciat-
ing it is that we all have enough trouble without borrow-
ing more.
The great danger lies in the neglect to release the start-
ing pin when the load become.- light, and — but this intro-
duces another matter — carelessness, which is not the sub
ject of this writing.
Regarding the one-engine plant, I can only repeat the
frequently iterated admonition never to block up the gov-
ernor unless an independent speed-limiting device is
part of the engine's equipment or the ingenuity of the
chief engineer has removed, or at least diminished, the
certain risk attendant upon the practice. Where neces-
sity spurs, it really is not a difficult matter to devise some
scheme to lessen the danger, as the many creditable ef-
forts that have been described and illustrated in power-
plant papers prove.
In one plant I was shown an ingenious device which I
mention because of its surprising simplicity. The type
of governor and the essential details are shown in the il-
lustration. A is the oil dashpot, in the bottom of which is
inserted a loose piston of a thickness equal to the depth
of the step in the movable rest-collar B. Leading from
below the throttle is the %-in. pipe C, which communi-
cates with the bottom of the dashpot and has the cock D,
whose handle connects with the arm of the idler, as a
shutoff.
It is apparent that the arrangement is such that when
the governor belt breaks, the idler will fall and open
the cuek, which, by supplying steam below the loose pis-
ton, should force the governor weights to their highest
position against the collar E. If one will remember that
the piston is always lubricated by the oil contained in the
dashpot, and that the steam-cock D is also prevented from
sticking by the same oil seeping past the loose piston
into the pipe, I think it will be agreed that its success is
probable if the diameter of the dashpot allows of sufficient
area. In no way does it lessen the utility of the dashpot.
R. 0. RlCHAKDS.
Framinu'ham. .Ma>s.
In a steam plant using water from the city main the
water meter got out of order, the readings being less
than they ought to be. The cause was located in the lay-
out of the triplex power boiler-feed pump, which had a
bypass from the discharge pipe to the suction.
There had been a light load for a couple of months and
the temperature of the feed water entering the boileiv was
higher than at normal load. The bypass was slightly open
most of the time, as that was the only way to reduce the
water-supply and to get a steady feed. This constant
circulation of hot water back to the suction pipe caused
considerable heat to get to the meter, which was located
near the pump, and put it out of order.
When a new meter was installed two horizontal check
valves were placed between the meter and the heater.
Later, there was a complaint, of a pulsation in the mains
of about 12 lb. I connected in the suction line an air
chamber made of 4-in. pipe capped on both ends. The
lower tap was tapped and made up with a lio-in. nipple
a valve and another nipple screwed into a tee on the suc-
tion line. The body of this air chamber was drilled and
tapped at the top and bottom for %-in. pet-cocks, and
these with the valve kept the chamber clear of water and
recharged with air. Since then there has been no pulsa-
tion or water-hammer.
John Powbbs.
Xew lied lord. Ma<s.
March 9, 1915 POWER
einiiuiiiiiiiii iiiiiiiuiiiiiiiiiiuini nnniiiiiiiiiiiiiiiiii mm iiffliniiiiii iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiniiiii Illinium ilium
349
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiinig
Iiniq^uiiiiriies of Gemier^Il IiMerestt
inn nil iniiiiiiiiiiiiiiiiiiii iiiiiiiiini iiiiiiiiiiiiiiiiiiiiiiiiniii i inn iniiiiiiiiiiiiiiiiiiiiiiiii miiiiiiiiiiiiiiiiiiiiniiiiiiii iiiiiiiini minim m iniiiiiiiiiiiiiiiiiiiiiin iiiiniiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiini
Calking of Butt and Double-Strap Joint — Where is the
calking done on a butt and double-strap boiler joint?
R. G. M.
On the outside along the edge of the narrower strap,
where the rivets are close enough together to obtain a good
calking pitch.
Steam Lap of Slide Valve — What determines the amount
of lap that should be given to the steam side of a D-slide
valve?
J. D. P.
The travel of the valve and the angular position of the
crank at the time of cutoff.
Delivery in Duty Trials of Pumping Engines — In making
duty trials of pumping engines what is the usual method
of determining the quantity of water delivered?
A. E. W.
The delivery is usually determined from plunger dis-
placement, after making due allowance for slippage and
leakage, which should be ascertained by actual test.
Units of Compression — What is meant by the term "units
of compression" as applied to the operation of a recipro-
cating engine?
S. C. N.
The expression has been used in designating the number
of clearance volumes displaced by the piston during its
compression of the exhaust. If, for instance, compression
of the exhaust begins at the completion of 75 per cent, of
the return stroke, then if the clearance is 5 per cent, there
will be (100 — 75) -=-5 = 5 units of compression.
Cleaning Heating Coils of Grease Deposits — How can
steam-heating coils be cleaned of grease that has been de-
posited by the use of exhaust steam?
W. C. C.
The grease can be removed by filling the coils with a
solution of caustic soda made in proportions of about 20 lb.
of soda to a barrel of water. The coils should be filled with
a warm solution, and after having them filled for about 24
hr. the solution should be drained off and replaced with
clean warm water, which should be blown out of one coil
at a time with high-pressure steam.
Setting Boilers with Same Heislit of Tubes — When two
horizontal return-tubular boilers, respectively 72 in. and
60 in. in diameter, are set together, should the upper rows
of tubes of the boilers be at the same level, so that there
will be the same height of safe water level in each boiler?
S. L. G.
There will be no advantage setting the boilers with their
upper rows of tubes at the same level, for dependence can-
not be placed on maintaining the same water level by con-
necting the boilers together below water line, as the proper
water level must be maintained by regulation of the feed
through a feed stop valve for each boiler.
Relative Economy of Engine with Increase of Speed —
If the main receiving pulley on a jack shaft is increased in
diameter from 72 in. to S4 in., requiring the engine to make
nine more revolutions per minute to drive the shaft at the
same speed, will not more steam be required by the engine
for driving the same power?
E. H.
There will be ~-/M, or %, as much work required of the
engine per stroke and less steam will be required per stroke,
and for the same economy the consumption of steam would
need to be only '/■, as much per stroke, but whether more or
less steam would be required per hour for developing the
same power would depend upon relative points of cutting
off and other conditions affecting economy.
Connecting Two Engines to the Same Receiving Shaft —
For obtaining the power of both engines would it be prac-
tical to connect a Corliss and an automatic engine to the
same receiving shaft?
J. W. D.
For good regulation it would not be practical, as the gov-
ernors would not synchronize. An approach to ordinary
regulation, though only for gradual loading and unloading,
could be obtained by adjusting the governor of the automatic
engine for carrying the load up to a point where its speed
would become reduced to the working speed of the Corliss
governor. Then, with the automatic governor blocked
against admission cf a greater amount of steam, the Corliss
engine could pick up any additional load with a reduced
speed. But anj sudden change of load would give rise to
spasmodic variations of speed of unusual extent and duration.
Besides the uncertainties of speed regulation there is an
additional objection to connecting the engines as proposed,
especially when they are widely separated, arising out of
the danger of starting up one engine and sustaining a water
smash in the cylinder of the other.
Running Shunt Motor as a Dynamo — At what speed will
a 30-hp., 115-volt, 120-r.p.m. shunt motor have to be run
when used as a dynamo?
H. G. C.
It will have to be run faster as a dynamo than as a
motor to deliver the same voltage to the line, because of
the drop in the armature circuit. In the motor the speed
will be great enough to produce a counter-electromotive
force equal to the difference between the impressed voltage
and the armature (IR) drop. In the dynamo the speed must
be such as to generate an electromotive force which, minus
the IR drop, will equal the line voltage.
To solve the problem accurately it will be necessary to
know the armature resistance. Assuming this to be 0.0S
ohm, then as a motor rated at 30 hp. and 115 volts will
have a full-load current of about 165 amp., the armature
drop would be approximately
165 X 0.0S = 13 volts.
The counter-electromotive force would be
115 — 13 = 102 volts
generated at 120 r.p.m. Run as a dynamo, the armature
would have to generate
115 +13 = 128 volts.
Therefore, as a dynamo, the speed would be
120 X 12S H- 102 = 150 r.p.m.
Changing Speed of Induction Motor — How can the speed of
an induction motor be changed?
F. II.
There are five ways in which this may be accomplished,
namely: (1) Changing the applied voltage, (2) changing the
rotor resistance, (3) varying the number of poles, (4) operat-
ing in cascade, and (5) varying the frequency.
The usual means under the first method is the use of a
compensator, or autotransformer. This method does not give
very satisfactory speed regulation; the efficiency and power
factor decrease with the speed.
In varying the resistance of the rotor winding a constant
speed is not obtained over the torque range of the machine,
but changes with the torque. As in the first case, the effi-
ciency decreases with the speed.
The third method is ap] licable when only two speeds are
desired; as the number of speeds increases, the necessary
wiring becomes cumbersome and complicated. The power
factor is not appreciably affected in this case, but as it is
necessary to open and close the supply circuit in making the
change, variation in primary current and fluctuations in volt-
age are apt to result.
In cascade operation two motors are necessary, the rotors
being connected together mechanically. The stator of the
first is connected to the supply and its rotor (which is of the
slip-ring type) feeds the stator of the second motor; the rotor
of the latter is usually connected to an adjustable resistance.
This method is frequently used where the speed changes are
frequently made, and the horsepower relatively high, such as
in electric locomotives. The power factor and efficiency of
two motors in cascade are less than a single machine of the
same capacity.
The fifth method mentioned, namely, varying the fre-
quency, is usually impracticable.
[Correspondents sending us inquiries should sign their
communications with full nanus and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
350
P 0 W E 11
Vol. 41. No. 10
[More stories of stupidity am! ignorance competing
with "Some Original Ideas" as printed Jan. 19, 1915.]
While I was employed in a large plant, it became.
necessary to remove the bonnet of a 36-in. valve. The
assistant engineer, the happy owner of License No. 1,
was put on the job. The valve bonnet had been un-
molested for many years. Afte1- he had worked for about
one hour, I discovered that ne had twisted off 31 of
the stud bolts. Two men had to work twelve hours drill-
ing out the studs with a ratchet and "old man'' to re-
pair the damage. Answer — Always cut the nuts with a
chisel. Nuts are plentiful and split easily with the grain
nf the metal. — Janus Browning, Juliet, III.
A few years ago, while 1 was running a lighting plant
in a small country town, a high-school professor visited
the plant one night witli his class in physics, and asked
my permission to explain the electrical apparatus to the
boys and girls. I gave my consent after cautioning him
to be careful not to let anyone get hurt. Then I prepared
to listen to the discourse myself, thinking this would be a
good chance to add to my small store of electrical knowl-
edge.
After lining his class up in front of the switchboard,
he said, "Now, first we will have a little demonstration in
magnetism," and taking a large jackknife from his pocket,
before I realized what he was doing lie placed it squarely
across the main switch. The report and flash that in-
stantly followed were appalling. The professor's hand
was badly burned, and the switch had two large scallops
melted out where the knife had touched it, and the back
springs, handle, and blades of the knife were Eused to-
gether. The professoT explained that he thought the
switch would attract the knife. — C. M. Knowland, Lot is-
ville, Ky.
In an artillery electrical plant an officious artillery en-
gineer annoyed the electrician sergeant very much by aim-
lessly playing with the apparatus. The sergeant, there-
fore, got some electric primers and concealed them in
a cable conduit and connected them to the dead side of
several switches, and then found important business else-
where when the officer appeared again. Of course, the
officious one started his usual performance, but very soon
heard an explosion, ami continuing his monkey business,
the noise was soon repeated. lie couldn't seem to locate
any trouble, and it "got his goat." He hunted up the
sergeant and breathlessly said: "I .-ay. sergeant, you'd
better go down there and see what the trouble is, for
every time I close a switch there is an explosion." And,
of course, the sergeant hurried away to make an investi-
gation.
Some years ago a central station in this vicinity was
operating several old Thomson-Houston arc machines. A
policeman on that beat frequently stepped in for a few
minutes. One night be came in looking kind of glum
ami remarked that he wasn't feeling very chipper — kind
of still' and rheumatic. When no one was looking he
took bold of both brushes of one of the arc machines. He
said afterward it was pretty harsh treatment, and one do-e
was enough, but maintained it knoc! 1 'be rheumatism
out of him. — //. L. Strong, Yarmoutkviile, Maine.
Posrttsilblle F&itmM ILocsvMseir
A portable fault localizer, for quickly locating a ground
on an electric cable has been developed by the Westing-
house Electric & Manufacturing Co. The position of a
ground is read directly from the dial in per cent, of
length of the defective cable. It is an application of
the wheatstone bridge, with all the necessary apparatus
contained in one portable case wired for connection to the
circuit to be tested. Its use assumes that the cable is
grounded at only one point and that a parallel conductor
of the same length and resistance is available.
After proper connections are made, a dial on the in-
strument is revolved by means of a knob in the middle of
the localizer until the galvanometer shows no deflection
when the key is closed. The reading of the meter then
gives the percentage of length of the feeder from the
point where the test is being made to the location of the
ground, assuming the total length of the feeder to be 10o
Para lie! Conductor
Outfit fob Locating Faults
per cent. : the red scale indicating that the ground is on
the conductor connected to the binding post marked red.
and the black scale indicating to the binding post marked
black. Direct current only is used in these tests.
The variable-resistance arms consist :>f two loops ot
low-resistance wire attached to the side of a revolving-
disk, upon which the dial is attached, so that contact i-
easily made from two brushes attached to the case and
connected to the galvanometer terminals. As the disk is
revolved the point of contact between the brushes and
the resistance loops is thus varied, as in the slide-wire
bridge. The dial is calibrated in percentage of the length
of the conductor tested, mi that the reading is direct.
;*■
IRwaHes f©2* TlhiicIKlimes© aimed! Weigphft
©if ILesidl Pap>es
The thickness ot lead pipe required to withstand a given
pressure may be calculated by the following formula:
0.433 X H X R
2 7 4 5
in which
T — Thickness of pipe in fractions of an inch;
H = Head of pressure in feet;
R = Radius of pipe in inches;
from which we get
T - 0.000157S X H X R
For lead a factor of safety of 10 is required, hence the last
rule becomes T = 0.00157S X H X R
or, if we take D = the diameter of pipe in inches, instead
of radius R, Ae get
T = 0.0007S9 X H + R
The formula for the weight of lead pipes is
W 3.S6 (D=— d-); or 3.S6 (D + d) X (D — d)
in which
W = Weight of pipe per lineal foot in pounds:
D = External diameter of pipe in inches;
d = Internal diameter of pipe in inches.'
3.S6 = A constant.
li 9, 1915
I' 0 W E If
351
Mm for ©ffff=Pes\K ILoad
By L. H. Morris
SYNOPSIS — Saving effected in a small municipal
plant where an oil engine was installed to handle
the load between midnight and 7 p.m., the steam
plan! handling the evening load.
At present much attention is being given to the oil
engine in the West and Southwest, where plants of small
and medium size are to be installed. However, it is not
alone in new plants that the oil engine finds application,
but also in existing steam plants where additional power
is necessary, or where a more economical engine is found
desirable to handle tbe off-peak load. This is especially
true as regards the small electric-light plants of capacities
up to three or four hundred kilowatts, where the load
from midnight until morning consists of the street lights
and a few residence lights, and where the day load consists
of a few motors of small power. In such cases a steam
plant of a size to carry the maximum evening load must
operate at a low load factor during fifteen to eighteen
hours a day, and the resulting cost per kilowatt-hour is
often too high to show a fair profit on the investment.
A situation along these lines arose in a municipal light
plant with which the writer is connected. This plant,
including the pole lines, etc., was purchased from a private
company some years ago at a total cost of $35,000. The
power house contained a 125-hp. noncondensing Corliss
engine belted to a 75-kv.-a. alternator, a 75-hp., high-
speed engine belted to a 40-kv.-a. alternator, two ?2-in.
I iy lS-ft. and one 54-in. by lb-ft. tubular boilers, together
with the usual switchboard, piping, pumps and heaters.
A fair estimate of the replacement cost of the plant,
including the building, would not exceed $12,000, leaving
the outside system to carry tbe remaining $23,000. less
the franchise value: although the entire plant and system
could be replaced for less than $20,000.
The load consisted of the lights for the entire town, a
few small motors, and a 15-hp. motor driving the city
water-works pump. The amount of water pumped was
approximately 72,000 gal. per day, the bulk of this being
used by the railroads ami mill. This pump was thrown
onto the line whenever the engineer found the water in
the standpipe getting low.
The plant has been under municipal control for about
four years, and at no time have the earnings been as
large as was expected. This, of course, led to much dis-
satisfaction and caused the resignation of several plant
operators. Finally, there came into office a new set el'
city official.; who were committed to a policy of running
the plant on a profitable basis, or of turning it over to
a private company.
This ultimately led to an investigation of the oil engine,
especially the high-compression type. It was generally
understood that the plant required a 150- and a 75-hp.
engine. The investigation readily proved that this type
of engine would have a high maintenance charge ami
would require higher-grade engineers than the town could
afford to employ, even though the fuel cost he exceedingly
low. The medium-compression or semi-Diesel was finallj
decided upon, but the entire scheme was abandoned upon
learning the cost of the two units.
Finally, a new superintendent was employed, who de-
cided to approach the matter in a more systematic way
and, therefore, ran a test on the plant with the idea of
learning the exact load and the total amount of fuel used
per hour.
Curve No. 1, Fig. 1, shows the hourly load for the
twenty-four hours. It will be noted that the output is
below 10 kw. from midnight until 6 p.m., while from 6
p.m. until 11 p.m. the load is considerable. Furthermore,
the crosses marked 1. 2. '■'>. etc., indicate the hours during
which the pump motor was in operation, from which may
be judged the load at these hours with the pump motor
eliminated (this motor required 13 kw. ). Curve No. 2
shows the fuel cost per hour, while curve Xo. 3 covers the
total fuel and labor cost per hour.
An examination of these curves shows that the coal
used per hour was out of all proportion to the kilowatt
output. It is readily admitted that the excessive fuel
charge is open to criticism, and it is self-evident that
Fig. J. Iloria.Y Load of Steam Plant
either the engines were in bail condition or the firing
was had. A tesl on the high-speed engine showed that it
used 59 lb. of steam per kilowatt-hour at full load, which,
while high, is not excessively so. in view of the belt loss.
Furthermore, a casual investigation of the firing method
in vogue during the hours of light load indicated that the
greater part of the less was in the boiler room. However,
even if the firing conditions had been improved, the
352
POWE E
Vol. 41, No. 10
fuel cost would still have been high, because of the
vavving- load.
As already mentioned, the original idea of purchasing
two nil engines had been abandoned on account of the
cosl : therefore, a plan was adopted whereby the plant
could use both a small nil engine and one of the steam
engines.
Houkly Load of Steam- and Oil-Engine
Plant
As a means of evening up the load a Ixii-in. duplex
power pump was installed to handle the city water, this
being driven by a 5-hp. motor operating twenty hours a
day. while retaining the centrifugal pump and motor
for additional fire protection. This would cause the load
to lake the form of curve No. 1. Fig. 1. In this way
the load would not exceed 40 kw. (hiring nineteen hours
of the day; and as the load each day was almost uniform,
it could be assumed with safety that this value would not
be exceeded for some time to come.
A 60-hp. medium-compression oil engine was purchased
at a total installed price of $3800. This engine was of
the single-cylinder horizontal type with a guaranteed
fuel consumption of 0.(>r>7 gal. of desulphurized fuel or
crude oil per horsepower-hour, and furthermore was to
have a 25 per cent, overload capacity. This was belted to
the 40-kv.-a. alternator already installed.
The setting of one of the 7 '.'-in. by 18-ft. boilers was
altered so that oil could lie used as fuel. This involved
but slight expense, as the alterations consisted of building
a eheckerwork of firebrick on the bridge-wall and of
covering the grates with a layer of cinders and firebrick.
This type of furnace is not ideal for the use of oil. but
is one quite generally used where there is a possibility
of changing hack to coal. Some time in the past the
plant had used oil as fuel when it could he obtained at
70 to site, pei- barrel, and consequently it was not acces-
sary to purchase a burner, pumping outfit or storage
tank.
The plan of operation was to run the oil engine from
midnight until 7 p.m. and then cut in with the steam
engine, it being easy to raise steam in about thirty min-
utes. The oil cost 3c. per gallon delivered. Very little
oil was actually used under the boiler from 11 p.m. to
12 p.m., as the steam was allowed to go as low as 50 lb.
during this hour, so that the oil saved here made up for
the oil used in steaming up between 6 p.m. and 7 p.m.
This saved about 1000 lb. of coal that would have been
used in banking fires and steaming up.
With this method of operation it was possible to dis-
pense with one man and to raise the salaries of the
two engineers. The night engineer worked from 7 p.m.
to 7 a.m., the (lay engineer from 7 a.m. to 7 p.m., while
the fireman's hours were from 12 noon to 12 midnight.
This allowed two men to be on duty during the heavy
load when the steam plant was in operation, and also gave
the day engineer time to do repair work each after-
noon.
As regards the total saving; it was impossible, of
course, in ordinary operation to find any one day's load
which corresponded exactly with the clay's run plotted in
Fig. 1. Consequently, arrangements were made to run
a twenty-four-hour test on a Sunday, wherein each hour's
load was made the same as on the first test with the
exception of the waterworks load, which was distributed
over twenty hours instead of seven.
Accordingly, on Saturday night the standpipe was
filled, a water rheostat was arranged for manipulating
the load and at midnight and each hour thereafter the
load was kept to the proper value. It was thought best
not to run the pump motor, as it was necessary to take
care of the commercial load, which might be slightly
larger than during the former test.
Fig. 2 shows the results of the test plotted as to load,
fuel cost and total cost. The oil engine, while handled
by the city employees, did not come up to the guarantee,
hut the ease of operation and apparent reliability more
than offset the increased fuel consumption. The steam
plant used a large amount of oil per kilowatt-hour, caus-
ing the fuel cost to be much higher during the peak
hours than it was during the corresponding hours of the
first test. However, all banking of fires was avoided,
with a resultant saving of fuel, and all things considered.
the oil proved more satisfactory.
For comparison, the costs per day under both con-
ditions are given below, showing a net saving of $2209.70
per year, which represents a return of 57 ^ per cent, on
the cost of the oil engine and the alterations to the boiler.
As soon as the city can raise more funds, a larger oil
engine will undoubtedly be installed.
Steam Steam
Plant and ( >il
Fuel: coal at $1.80 per ton, oil at $0.03
per gal $11.60 $7.29
Labor: 2 engineers at $72 per month, 2 fire-
men at $60 8.80
2 engineers at $S0, 1 fireman at $60 7.33
Total cost per day $20.40 $14 .62
Net saving per day $5.78
Net saving per year 2209.70
Cost of engine and alterations 4200.00
Cost less value of old steam engine 3S50.00
Saving on investment 57 ^£ per cent.
The amount of lubricating oil was practically the same
on each test owing to the bad condition of the high-speed
engine.
March 9, 1915
p o \v e n
353
M sue Ih ana 5 nag* m Pas&oira Rairagl
By <;. Strom
A piston ring with a plain Burface will wear to its
bearing in four or five hours if properly made and fitted.
The real cause of leakage is distortion of the ring in man-
ufacture. Fig. 1 shows some of the effects of such dis-
tortion.
To produce a properly fitting piston ring, a easting of
the required dimension is secured. A spider with the
same number of screws as there are jaws in the chuck is
then inserted and the screws tightened slightly, Fig. 2;
this is to prevent springing the casting when chucking.
diagonally, using a hacksaw or milling cutter, and
fitted into a chucking fixture G, Fig. 1. which is T1jj in.
larger in diameter than the finished ring and is relieved
ys in. for one-sixth of the circumference opposite which
the cut in the ring i- placed. This is to allow the points
to spring slightly outward and when turned off will pre-
vent the point- from "digging" into the cylinder.
The fixture with the ring inside is put on the special
faceplate P and tightened. The chucking fixture is then
removed and the face of the ring turned. Only one ring
at a time should he chucked; if several are placed together
they will buckle and he spoiled. A diamond-pointed tool
should lie used with a V,00-in. feed per revolution. Three
DISTORTION DUE TO
■HAMMERING UPON THE
RIN6 WHEN CLAMPED IN CHUCK
DISTORTION DUE TO DULL
CUTTING TOOLS WHEN
MACHINING
LATERAL DISTORTION
DUE TO THE CHUCMN3
STRAINS
FIG 2
PISTON RIN5 PROPERLY
CHUCKED FOR FACING OF B
This space to clear
the points of ring£
A or 6 cap screws
1 according to diameter
T
spa
FIG. 3. EXPANSION CHUCK FOR
FACING RING
EXPANSION DISK
FIG.4 PISTON RING FILING
AND CHUCKING FIXTURE G.
FIG.5. PISTON RING CHUCK WITH
RING, PLATE P, AND CHUCKING
FIXTURE IN PLACE
Process of Machining Piston Rings ind Some Distobtions
The casting is then placed in a lathe, chucked upon the
spider screws and end B faced true. Holes // are drilled
for bolts or tapped for capscrews for bolting to the face-
plate. This must lie faced true. The casting is ma-
chined to the required dimensions, allowing g^-in. thick-
ness and width for re-turning. In both machining and
cutting-oil' operation- the tools must lie kept sharp, other-
wise the ring will have a wind impossible to remove.
The ring is then placed on an expansion chuck, Fig. 3,
to have its sides faced a- follows: Place the ring, which
should be a sliding fit. on the expansion disk, loosen the
four capscrews slightly, press the ring against the chuck
plate with a board, tighten the taper plug and the cap-
screws and then all is ready for facing. Three light cuts
are required on each face, using 1/ln„-in. feed.
After both sides of the ring are finished it is split
cuts should be taken across the ring with a sharp tool,
allowing Viooo f°r the finishing cut. The finished ring
should be the diameter of the cylinder plus Viooo f°r
wearing in. and no filing is necessary. The piston should
have dowel pins to keep the ring from rotating. In
slipping the ring on the piston and into the groove a
tin shield should be used instead of wire nails, ami the
like, as is sometimes done.
In fitting new rings no allowance need he made for cir-
cular expansion. This will leave the joints tight when
the ring has worn to a bearing and there will be no blow-
ing or leakage.
It might be argued that so tight a ring would score and
cut itself and the cylinder. This is not true. A tight
piston will quickly score its cylinder, but a tight ring will
not. The foregoing is for rings ranging from 3-in. to 18-
354
POWER
Vol. 41, No. 10
in. diameter and y8 to ^ in. thick and from & to 1 in.
wide. The following table gives the dimensions of sev-
eral sizes of rings and the allowance for tension.
PISTON RING DIMENSIONS
Diam. of Width of Thickness of Diam. of Ring Allowance for
Finished Ring, Finished Ring. Finished Ring, before Splitting, Tension on
In. In. In. In Ring. In.
IS 1 ft ISA ft
0
!
9
i
8
A
7
A
6
5_
5J
5$
I
4J
i
17ft
16*
ISA
"ft
13}
12i
Hi
10ft
Bft
m
I,'-
4J
3i
E5xteia@i©im ©If ttlhe Duaiastoia
The much discussed Dunston Station at Newcastle-upon-
Tyne has been undergoing extensions, although completed
only four years ago. An agreement was entered into with
the Teams Byproducts Co., Ltd., to purchase the surplus gas
from a large battery of Otto-Hilgenstock coke ovens about
1U miles from the Dunston Station. Gas is carried to the
station in 16-in. welded steel pipes and is burned under
water-tube boilers. The station was originally laid out for
four 6000-kw. units, only three of which were installed. The
new installation consists of a 12,000-kw. turbo-alternator
of the impulse reaction type, built by Richardsons, West-
garth & Co., Ltd., and Brown Boveri — the turbo and alter-
nator, respectively. Merz & McClellan, of Newcastle-upon-
Tyne and Westminster, are the consulting engineers.
8
E)©©asa©ia fes= Mtuuaacap&E ILagpht
Columbus, Ohio, has a municipal light plant which has
been in operation for several years, and in the past few years
has been selling some of its day output to private parties.
A citizen, James M. Butler, sought from the courts an injunc-
tion against the city to prevent this practice, the case being
outlined in the Jan. 20, 1914, issue of "Power." Since then
the newly elected city solicitor, Henry L. Scarlett, has defend-
ed the city.
There were two main contentions made in support of the
petition and amendment by plaintiff's counsel: (1) That the
City of Columbus, by reason of the sale of current from its
electric light plant to private consumers at less than cost is
operating its plant at a loss, which loss must be paid by the
taxpayers; and (2) that in the sale of such current there is no
uniformity or classification of prices among customers. The
operation of the plant by the city officials under these condi-
tions was claimed to be such a. gross and manifest abuse of
their discretionary powers and such a disregard of the rights
of the taxpayers as to amount to fraud upon them, entitling
plaintiff as a taxpayer to an injunction..
The city solicitor argued in reply that an electric-light
plant, such as is owned by the City of Columbus, is operated
by the city acting in its proprietary capacity as distinguished
from its governmental capacity. Thus the plant would be
run as a business concern and, as such, might have pr:..its
and might have losses. The sale of electricity for private
purposes so far has been incidental, in order to dispose of
a portion of the day load, which otherwise was a waste
product. The principal use of the plant being for lighting
the streets and other public places, it is apparent that when
the night load and a very small part of the day load are
utilized on city properties the entire operation and main-
tenance cost, including interest and depreciation on the in-
vestment, is a burden upon the public. If the sale of the
extra available day load to private consumers pays the extra
operating cost incurred by its generation and a proper de-
preciation and interest charge on the extra equipment neces-
sary for its generation and distribution, and contributes
anything, however small, to the fixed charges, then the day
load is sold at a benefit to the city and not at a loss.
Municipalities and their officers have the legal power, and
it is their duty to apply the surplus power and use of all
public utilities under their control for the benefit of their
cities and citizens, provided always that such application
does not materially impair the use of these facilities for the
purpose for which they were primarily created.
As to its rates for private service, the city plant was in
competition with a privately owned plant, and had to meet
that competition as any business concern would. It did not
have enough power to supply the whole city, and therefore
furnished electricity to such customers as might use a suffi-
cient quantity, in the judgment of the officers, to net the best
returns. The contracts were entered into voluntarily by the
private parties, and the rates made were agreed to and were
satisfactory. No intimation was raised by the plaintiff that
a higher price would have been secured, and so no foundation
is laid for charge of fraud. No private consumer had sought
court relief on the basis of unequal rates.
Judge Rodgers ruled against the plaintiff and in favor of
the defendant, the city, and denied the injunction sought.
Some quotations from his ruling are of wide interest, and are
as follows:
I am unable to reach the conclusion that the pleadings
make a case for injunctive relief, either on the ground of mis-
application ot corporate funds, or abuse of corporate powers,
or the execution or performance of contracts in contravention
of the laws governing the city, or through fraudulent or
corrupt procurement. The right of the city vO furnish electric
current to private consumers is conferred by statute wherein
it grants the power to establish, maintain and operate munic-
ipal lighting, power and heating plants, and to furnish the
municipality and the inhabitants thereof with light, power
and heat, and to procure everything necessary therefor. And
in the exercise of this power the city is exercising an admin-
istrative function. It is fundamental that, in the exercise
of such duty, courts will not interfere unless the discretion
of the officials is so grossly and manifestly abused as to
amount to a fraud upon the taxpayers and a disregard of
their rights.
Apparently, the theory of plaintiff's counsel is that, what-
ever service the city renders to one of its private citizens,
it must be remunerative at least to an amount equal to the
cost of the service. In other words, the service must be self-
sustaining: otherwise it cannot be rendered by the city to
the individual.
I do not understand that this is the theory upon which
the various public utilities of a municipality are operated by
it, such as the water-works, lighting and power plants, gas
plants, garbage- and refuse-disposal plants, the removal of
ashes and other refuse from the residences of its citizens
and the like.
The statute granting authority to cities to furnish light
and power to its inhabitants does not confer power on the
city to sell electric light or power to the inhabitants, but
confers power to furnish such light and power. Whether
such light and power may be furnished above, at or below
cost or even free to the inhabitants, does not appear by the
express language of the statute. . . . The city is given
power to furnish its citizens electric light and power, and
it is left with the city to fix the terms upon which such light
and power may be furnished. If the city sees fit to furnish
light and power to its inhabitants at less than cost, I see
nothing in the statute to prohibit the city, through its offi-
cials, from exercising its discretion to that end. If plantiff's
contention were correct, that in the sale of electric current
to the inhabitants there must be no loss to the city, and
that the sale price must at least equal the entire cost of
production, a municipal plant might never be able to furnish
its citizens with electric light or power. Of necessity, every
municipal plant of this character must start with a few
customers; yet as a matter of economy must make prepara-
tion in the way of lands, buildings, installation of machinery,
wiring, poles, and the like, for probable future increase of
business. On the other hand, if the power conferred by the
statute upon the city to furnish electric light and power
to its inhabitants is construed to mean authority to sell at
such prices as the city may determine, the city in the exercise
of its proprietary functions is put in a position to operate
the plant as business men would engage in a like enterprise.
As a matter of economy business men would probably build
their plant, not alone to supply present needs, but in antici-
pation of probable future demands, with the view that the
future returns on the investment on account of increasing
business would make up for any present losses.
The statutory authority of cities to furnish electric light
and power to the inhabitants is found in the general enumera-
tion of powers recited in the statutes, and these powers
include the power to maintain police and fire departments, to
provide for a supply of water, to establish, maintain and
regulate free public band concerts and free public libraries.
to provide for the renting of free public hospitals, to provide
for the collection and disposal of sewage, garbage, ashes and
animal and vegetable refuse, etc. For the use and benefit
of its citizens the city charges them for some of the benefits
above mentioned which the city has power to furnish, and
for others it makes no charge whatever, as for example, the
removal of garbage, ashes and refuse matter and the extin-
guishing of fires.
As it appears to me, so far as the city has the power to
and is furnishing a part of its inhabitants electric current, who
are willing to pay the price therefor, it is not within the
province of the court to interfere with the prices at which
the city is disposing of its electric current, merely on the
ground that the city thereby is losing money.
A further contention is that the prices charged for the
electric current are not uniform under the same or like condi-
tions and are discriminatory among the city's customers. I
am inclined to the opinion that the pleadings show a wrong
in this respect that is in need of a remedy. That ;i citj
through its officials cannot discriminate in furnishing service
of any kind to its citizens, but must act impartially in furnish-
ing such service, appears to be fundamental. However, is
the plaintiff a proper party to make complaint? The dis-
crimination in rates charged and paid for the electric current
March 9, 1915
POWER
355
in no wise appears to affect the plaintiff as a taxpayer. In
other words, it is not shown that his taxes would be less if
there were no discrimination in rates, or in fact would be
affected either way: nor does it appear that he has sought
to have the city furnish him service at a reasonable rate,
and it has been refused, although the city is furnishing like
service to others on more favorable terms. In this view of
the case I am of the opinion that the plaintiff does not allege
sufficient facts in the respect just mentioned to entitle him
to injunctive relief.
'&.
M.^&<e Fualblllcl^ ©ipdosredl
One of the most far-reaching orders that the upstate Pub-
lic Service Commission of New York has issued in years
went into effect Feb. 15, requiring the rate schedules of all
gas and electric corporations and all municipalities subject
to the regulation of the commission to be filed in the com-
mission's office, and to be kept in convenient form for the
inspection of customers at all offices of such corporations
and municipalities where contracts for service are made or
payment for services received.
This order follows out the plan of the commission in
regulating other corporations under its control, and requir-
ing the fullest publicity of all rate schedules in order to
prevent discrimination. The order specifies that the rate
schedules are to be uniformly printed and that when asked
for by a customer the person having charge of them in the
corporation's office shall give all necessary assistance in
gaining information therefrom. The schedules include not
only rates, present or proposed, but regulations for service
and privileges and facilities under each rate.
Tlhe C©s°2ros!®ia of CoiadleEasep
"We have received from E. Bates, "White Bay Power House,
Sydney, X. S. "W., a copy of a paper on the corrosion of con-
denser tubes, read by him before the Electrical Association
of New South Wales in 1913. In this paper Mr. Bates states
that the exceedingly serious corrosion of condenser tubes ex-
perienced at the Ultimo power station of the Sydney Tram-
ways had been completely checked by the simple procedure
of painting the whole of the interior of the cast-iron water
boxes with an anticorrosive paint. Following the success
at Ultimo, the same procedure was adopted with equally good
results at the power station of the Adelaide Tramways, where
much trouble had been experienced from condenser-tube cor-
rosion. Attempts to check this by improving the contact
between tubes and tube-plate and by suspending zinc plates
in the water boxes had all failed, but on learning of the
results achieved by Mr. Bates at Sydney, it was decided to
try the same plan at Adelaide. In the first instance, the in-
terior of the water boxes, covers and pipes of one condenser
were painted with three coats of biturine solution. The re-
sult was that the corrosion did not recommence until the
paint was washed off. Subsequently an anticorrosive paint
was used, and was found to last three times as long as the
biturine solution.
As is well known, many engineers have made claims to
success in stopping condenser-tube corrosion, but in many
cases an extended trial has proved these pretensions to be
illusory. An example brought forward at the discussion on
Mr. Bates' paper was one presented at the Ithaca meeting
of the American Association for the Advancement of Science
in 1906, by W. W. Churchill, who declared that tube cor-
rosion at the Bay Ridge station of the Brooklyn Edison Co.
had been traced to stray currents and that the trouble had
been completely checked by installing a booster to provide
a counter electromotive force. One of the speakers on Mr.
Bates' paper related, however, that he had visited New York
subsequently and learned that the plan in question had
proved a complete failure, and that the booster sets provid-
ing the counter electromotive force had been thrown out of
service. It is therefore interesting to learn from Mr." Bates
that his system is still in use at the Sydney power stations,
and with excellent results.
The trouble originally arose with the condensers of cer-
tain 5000-kw. turbo-generators. Electrolytic methods of
protection were tried on the installation of a new unit, and
for eight months this condenser gave no trouble and elec-
trolytic protection was deemed a success. Then, however,
the tubes began to fail rapidly. It was therefore decided to
try Mr. Bates' plan on two of the older condensers, and when
it proved successful with them, the same process was adopted
in the case of the new condenser, the electrolytic protection
being dispensed with. During the succeeding nine months not
a tube failed in this condenser.
Mr. Bates' method is based on the hypothesis that the cor-
rosion, being of the pit-hole type and practically confined
to the bottom of the tubes, must be due to the deposit of
electro-negative material, and this material must, he con-
cluded, have been derived from the corrosion of the cast-iron
water boxes. He states that once a pit hole is started by
the deposit of such material, the corrosion will proceed even
if the initiating cause be washed away subsequently, since
when local corrosion has commenced the "balance" of the
alloy is upset. The ordinary condenser tube has, he says, a
composition giving a minimum waste by corrosion in normal
conditions. If the constitution is altered locally by selective
dissolution following the deposit of electro-negative matter,
then, even when the latter is removed, the corrosion will
continue, owing to the "balance" of the alloy having been
disturbed.
During the 15 months which have elapsed since Mr. Bates'
paper was read the number of tubes removed from the two
older 5000-kw. condensers has, he informs us, not exceeded
three per month, while before the Bates method of protection
was adopted it was not uncommon to lose 150 tubes from one
condenser in a single week. — "Engineering."
Digested by A. L. H. STREET
Daniagen Caused By Power Dam — A hydro-electric power
company is liable to a suit in a county into which its dam
backs water to the injury of inhabitants of that county,
although its principal place of business and its plant may
be in other counties, according to the decision of the Georgia
Supreme Court in the case of Central Georgia Power Co. vs.
Stubbs, 80 "Southeastern Reporter" 636. The court decided these
further propositions: The Georgia statute, which permits
suit to be brought in the county where the cause of action
arose, is not unconstitutional. If water is so impounded by
the dam as to create a nuisance, to the injury of an adjoining
landowner, he may recover damages, including those brought
about by sickness of himself and family caused by the nui-
sance, but, the conditions complained of being permanent, he
must recover all of his damages in one suit, not being entitled
to prosecute successive actions for continuing injury. The
power company is not liable for loss of trade at his mill
resulting from people moving away on account of the nuisance.
Insurance of Boilers — A peculiar case involving the lia-
bility of a fire-insurance company on an ordinary fire-insur-
ance policy for injury to a stationary boiler was recently
passed upon by the Kansas Supreme Court. It appears that
at the close of a business day the boiler was left more than
half full of water, with the gas which furnished the fuel
turned off. The next morning it was found that someone had
entered the building and caused the fire to be restarted and
kept up long enough after the water was exhausted in steam
or by draining to injure the boiler. The next morning the
gas was found turned off. On these facts the Supreme Court
decided (McGraw vs. Home Insurance Co., 144 "Pacific Re-
porter," J21) that the evidence was insufficient to warrant
the inference that someone not connected with the plant had
maliciously caused the injury, so as to render the insurance
company liable for the loss. The court holds that proof of
the facts stated was not inconsistent with the injury having
been caused by someone connected with the plant, in which
case the insurance company could not be held on the policy.
Responsibility for Boiler Explosion — In lately affirming
judgment against the defendant in the case of Eberts vs.
Mount Clemens Sugar Co. (148 "Northwestern Reporter," 810)
for injuries sustained by the plaintiff, an employee of the
defendant, in a boiler explosion, the Michigan Supreme Court
held that an employer's duty to make proper inspection of
boilers to promote the safety of employees cannot be dis-
charged by merely entrusting it to a certain employee. In
other words, an employer is liable for injury directly at-
tributable to the negligent omission to discover any defective
condition of a boiler, although the immediate act of care-
lessness may have been that of a co-employee of the injured
worker to whom the duty of inspection was entrusted. In
this case it was the plaintiff's theory that the rear stay-plate
of the boiler became bulged or corrugated by overheating,
that this was a dangerous condition likely to result in a
failure or explosion, and that an inspection, which was negli-
gently omitted, would have disclosed such condition. On the
other hand, the defendant claimed that the condition could
not have been discovered by a reasonable inspection before
the accident and that the initial rupture occurred not in t!i
stay-plate, but in the combustion chamber.
3.36
P 0 W B 1!
Vol. 41, No. 10
H. WARD LEONARD
H. Ward Leonard, the well known electrical engineer,
died suddenly at the Hotel Astor, New York, on Feb. IS, while
attending- the annual banquet of the American Institute of
Electrical Engineers. He was born in Cincinnati, Feb. 8,
1S61, was graduated from the Massachusetts Institute of
Technology at the age of 22, and a year later became asso-
ciated with Mr. Edison in the introduction of the central-
station business. After three years in this line he was with
the Western Electric Light Co. for a short period, and later
became part of the firm of Leonard & Izard. This concern
was finally absorbed by the Edison company, and Mr. Leonard
became general manager of the combined Edison interests.
In connection with the Ward Leonard Electric Co., which
he founded, his later life was identified with a large number
of important inventions, among which are the Ward Leonard
system of motor control, used generally by the U. S. Navy;
the well known multiple-voltage system which bears his
name, a lighting system for trains and automobiles, and
an electric gear shift, besides other inventions relating to
mine hoists, electrically driven reversible rolling mills, lo-
comotives, elevators and gasoline-electric trucks. In 1903
he was awarded the John Scott medal by the Franklin In-
stitute, and also received medals at both the Paris and the
St. Louis Expositions. He was a life member of the Amer-
ican Institute of Electrical Engineers. A widow survives
him.
The Irish-American Association of Stationary Knpriiieers
is the newest organization in this craft. It meets at K. of
C. Hall, SI Hanson PI., Brooklyn. Harry F. Burns, at the
same address, is president.
National District Heating Association — The next annual
convention will be held in Chicago, June 1, 2 and 3, 1915, with
headquarters at the Hotel Sherman. The papers will be:
"Commercial End of the Heating Business," by C. F. Oehlman,
of the Denver Gas & Electric Co., Denver, Colo.; "Typical Hot
Water Heating Plant," by W. G. Carlton, New York City;
"A Pressure Study Survey," by C. C. Wilcox, of Common-
wealth Power Co., Jackson, Mich.; "Exhaust Steam vs. Live
Steam for Heating," G. W. Martin, New York City; and a
paper, the title of which is not yet announced, by E. F.
Tweedy, of the New York Edison Co. Reports will be made
by the committees on rates, underground construction, public
policy, education, meters, station operating and station rec-
ords. In addition, there will be three addresses by men of
national reputation. Altogether, the next convention promises
to exceed in attendance and interest any that the association
has ever held.
MEW PUJBILHOATHONJ
PRACTICAL IRRIGATION AND PUMPING. By Burton P.
Fleming. Published by John Wiley & Sons, New York,
1915. Size 6x9 inches; 260 pages; cloth. Price, $2.
According to the author, the farmer is now looking toward
the vast areas on the higher ranges, or mesas, where the
latent agricultural possibilities of the soil are enormous. To
irrigate this land means the pumping of surface and sub-
surface water, and it is the purpose of this book to treat
chiefly of the subject of pumping. The author considers the
matter of wells and well sinking, pumps, pumping machinery,
selection of prime movers for pumps, and irrigation by wind-
mill-operated pumps. The chapter on pumping costs should
prove interesting to those interested in irrigation. Con-
tractors and engineers, who are called on in their professional
capacity to solve the pumping difficulties of irrigation jobs,
should find the book of value.
HANDBOOK OF FORMULAS AND TABLES FOR ENGI-
NEERS. By Clarence A. l'ierce. instructor in power
engineering in Sibley College, Cornell University. With
mathematical sections by 'Walter B. Carver, assistant
professor of mathematics, Cornell Universitv. Published
by the McGraw-Hill Book Co., New York. Flexible
leather; 16S pages; thin paper; tables and diagrams.
Price, $1.50.
This book is a compendium of tables and formulas fre-
quently used by students and practicing engineers in mak-
ing calculations in higher mathematics, mechanics and
machine design, and should be found of great convenience
to those who may have forgotten or are doubtful of some
of the applications cf higher mathematics in the solution
of enginering problems.
The work is divided into 10 principal sections, covering the
subjects of algebra, geometry and trigonometry, analytical
geometry, calculus, measurements, physical and chemical
properties of substances, mechanics, strength of materials,
standard gages, fastenings and flanges, and mathematical
tables. It also gives a Mollier entropy chart of the thermal
properties of steam. The book affords in convenient form a
collection of tables and formulas most commonly used by
engineers and for which they have usually been dependent
upon reference to a number of handbooks and textbooks.
BUJSHB3ES
The Lea-Courtenay Co., 90 West St., New York, due to
increased business, has opened its own Chicago branch in
the Conway Building, with Mr. Maher, formerly of the Maher
& Byrne Co., as manager.
The Whitlock Coil Pipe Co., Hartford, Conn., has just
published Bulletin No. 22, Series No. 3, dealing with the
subject of heating surfaces in steam actuated water heaters.
Copies are mailed on request.
The Schaeffer & Budenberg Mfg. Co., in order to take
care of its increasing business, has moved its offices and
plant to the splendid new building at South Fifth and Berry
St., Williamsburg, Brooklyn, N. Y.
"Central Power Station Economy" is the title of a very
interesting booklet published by the Wm. B. Scaife & Sons
Co., Pittsburgh, Penn. It is a treatise on water purification
for all purposes. Copies are mailed for the asking.
The Combustion Engineering Corporation, 11 Broadway,
New York, has just issued a new booklet descriptive of the
type "E" stoker. It is a 20-page booklet, well illustrated,
giving a complete description of the stoker, construction and
operation and showing several installations. Copies are
mailed on request.
William B. Merrill & Co., 336S "Washington St., Boston,
Mass., has received order to furnish "Tripp" metallic pack-
ing for all piston rods and valve stems of the new steamer
now being built for the New York & Porto Rico Steamship
Line. The company has also received during the past month
orders for 234 sets of "Tripp" metallic packing from In-
gersoll-Rand Co.
COHTIFIACTS TO BE ILET
Bids received until liar. 12, 1915.
Five Pumping Engines
MAYFAIR PUMPING STATION.
Department of Public Works.
Chicago, February 17, 1915.
Sealed Proposals will be received by the City of Chicago
until 11 A.M. Friday. March 12th, 1915, at Room 406 City
Hall, and then publicly opened, for furnishing and erecting
five pumping engines at the Mayfair pumping station, Chi-
cago, as follows:
Three pumping engines, capacity 25 million gallons per
day, normal head 140 ft.
Two pumping engines, capacity IV % million gallons per
day, normal head 200 ft.
The contract includes discharge piping and suction con-
nections for seven engines, according to Plans and Specifi-
cations on file in the office of the Department of Public
Works of said City, Room 406 City Hall.
Proposals must be made out upon blanks furnished at
said office, and be addressed to said Department, indorsed
"Proposals for Five Pumping Engines, Mayfair Pumping
Station," and be accompanied with Twenty-five Thousand
Dollars in money or a certified check for the same amount
on some responsible Bank located and doing business in the
the City of Chicago and made payable to the order of the
Commissioner of Public Works.
The Commissioner of Public Works reserves the right to
reject any or all bids.
A deposit of three hundred dollars ($300.00) will be re-
quired to insure return of plans and specifications.
No proposal will be considered unless the party offering
it shall furnish evidence satisfactory to the Commissioner of
Public Works of his ability, and that he has the necessary
facilities together with sufficient pecuniary resources to ful-
fill the conditions of the Contract and Specifications, pro-
vided such Contract should be awarded to him.
Companies or firms bidding will give the Individual names
as well as the name of the firm with their address.
L. E. McGANN,
Commissioner of Public Works.
!3, SF
Vol. 4!
POWER
NEW YolfK. MARCH 16, L915
%J!S#
No. 1 1
© it'liresnaaEa
35S
POWE B
Vol. 11. No. 1
^tleimsioini ©i
Cob Plant
By. W'aiikkx » ». Rogers
SYNOPSIS— The chiej features <<\ the station
equipment are water-tube boilers having superheat-
ing coils, and eight steam turbines consisting of
three 8750-kv.-a., four 5000-kv.-a. and our ',250-
Icv.-a. units; a combined forced- and natural-
draft system is operated with the new boilers, the
forced-draft fans being turbine driven and the
first to operate with a reducing gear between the
fan and turbine.
It is doubtful if any steam-power plant in this coun-
try operates with so much depending on continuity of
service as the one at Cos Cob, Conn., which supplies elec-
trical energy to the New York, New Haven & Hart-
turd RE.
When the Cos Cob plant was first built and the New
Haven system was electrified as far as Stamford, Conn.,
11,000 volts, single-phase, was the working voltage of the
of overhead-contact wire insulation, together with roll-
ing stock and other apparatus, would require replacing.
Under the old system all of the current flowing in
cither the overhead wire, the rails or ground return was
in the same direction for the greater part of the trackage
involved. With the new arrangement the generators at
the power house do not directly feed the contact wire.
but are connected to 2 2, 000- volt auto-transformers at the
power house, which have their centers grounded to the
rails : the terminal voltage of the generators is, as former-
ly. 11,000 volts. One terminal of the transformer is
carried to the contact wire and the other to feeder wires.
Tuhbine l'i. \ \ I
Two views of the turbine room are shown in Fig. 1,
in which there are eight horizontal steam turbines with
a total rated capacity of 35,500 kv.-a. : single-phase, 25-
cycle current is used for railroad electrification, but three-
phase for the other transmission.
Fig. 1. Two Views of the Co- Cob Ttjkbine L'i.
generators and on the lines. The voltage was supplied
from the generator terminals to the contact wires with-
out the aid of transformers. A- this was a departure
from existing practice, new problems and difficulties,
naturally, were introduced, hut the system was developed
and the difficulties were overcome with two exceptions.
One was that of electro-magnetic disturbances in neigh-
boring telegraph and telephone circuits paralleling the
railroad tracks. This disturbance had been corrected in
a measure, hut with the necessity of using larger currents
as traffic increased, the adding of neutralizing trans-
formers and other corrective apparatus did not appeal'
satisfactory.
The other need was in relation to transmission volt-
and as it was planned to extend the electrification
of the New Haven line- to New Haven, a distance of 15
miles, as well as to take on the Harlem River branch
and freight yards, it was necessary to add to the original
plant the turbines and boilers required to carry the in-
creased load. There were difficulties in the' way of
raising the transmission voltage, because about 350 miles
The turbines of the old station are connected to surface
condensers having engine-driven circulating and inde-
pendent air pumps. The four new turbines exhaust into
jet condensers. Fig. 2 shows an elevation of the piping
and arrangement of the condensers in the basement. Fig.
■'! is a side elevation of the new boiler room.
Exciter current is furnished for the generators in the
old plant by two 12 and 22 by 13-in. compound-vertical
engines, each directly driving a 125-kw.. 125-volt, direct-
current generator. For the new units there are two tur-
bine-driven, 125-kw., 125-volt generators driven through
a reducing gear from one turbine. There is also one 125-
kw., 125-volt generator driven by a 190-bp., 110-volt in-
duction motor at 480 r.p.m. and one IT'o-kw., 125-volt
generator driven by a 260-hp., 440-volt induction motor
at 480 r.p.m.
Along one side of the turbine room are two turbo-gen-
erators of 130-kw. capacity, each delivering 2300-volt,
single-phase, 60-cycle alternating current at 3600 r.p.m.
The electrical energy developed by these units and from J
a motor-driven set consisting of a 500-hp.. 110-volt indue-
March 1G, 1915
POWE E
359
tion motor and a i50-kv.-a.. 2300-volt alternating current. Ian placed above the boilers and between the economizers
three-phase, 60-cycle generator at 720 r.p.m., is for op- and the stack. The furnace gases from eight boilers pass
crating railway signals. The plan view. Fig. k shows through two economizers and those of the other six pass
the location of the various units in the new half of the through but one before going to the fan and stack,
plant. There is a noticeable absence of piping in the In the boiler-room addition there are 11 water-tube
•ischarge-
Flume '''"■" ; •>, _.
Intake Flume-
Fig. 2. Side and End Elevation of Turbine and Condenser Rooms
jrTqT^/)l!>J'_>i>ilbJi&l&/&&!^2?X
Feed Wafer
Heater
~— Forced Draft Fans
dol/er Feed Pumps Future Fan Forced Draft
Forced Draft
Fan
Pig. 3. Side Elevation of the New Boiler Room
urbine room and but little in the boiler rooms; most of
he pipe lines are in the basement.
Boiler Rooms
In the old boiler room, Fig. 5, there are 1-1 three-drum
ater-tube boilers, each having 5200 sq.ft. of heating sur-
ice. The furnaces are fitted with mechanical stokers,
'he boilers are arranged two in a battery, with eight on
ne si,l,, ;,,,,] ^ on the other side of the boiler room.
ach furnace is supplied with induced draft by a single
boilers (Fig. 6), each having 6250 sq.ft. of heating sur-
face. The tubes are 14 and 18 ft. in length and 3*4 in.
in diameter. These boilers are of the counter-current
type, the hottest water meeting the hottest gases and the
coldest water meeting the coldest gases. The direct heat-
ing surface, or that in contact with the radiant heat of
the furnaces, is 12 per cent, of the total heating surface,
or \ 50 sq.ft.
The boilers are equipped with superheaters, which sup-
erheat the steam 100 deg. F. Each boiler furnace is fitted
oGO
imi w E 1;
Vol. 41, No. 11
ECONOMIZER
50 SECTIONS LONG
12 TUBES WIDE
Fig. 4. Plan of the New Section of the Plant
with a seven-retort underfeed stoker driven by the in-
duced-draft fan turbine. A combination forced- and in-
duced-draft system is used. There are three double-inlet.
up-blast, forced-draft, turbine-driven fans (Fig. ?) in the
pump room, which is under the firing aisle of the boiler
room. Each fan is 42 in. in diameter and delivers 100,-
000 cu.ft. per min. at 50 deg. F., against a resistance of
5 in. of water. This would require 190 hp. per fan at a
fan speed of 510 r.p.m. The turbines run noncondens-
ing at 2040 r.p.m.. against a hark pressure of about two
pounds. Each has sufficient capacity to supply about
twenty-five horsepower more than is required by the fan,
for the purpose of driving stoker mechanism. Under
normal operating conditions but two of the three fans
are in operation, and the capacity required of them
with the boilers running at 200 per cent, rating will be
95,000 cu.ft. per min. per fan. At this load the main-
tained resistance is figured to be only 4 in., but 5 is
supplied to be on the safe side.
The speed of the fans is governed by the boiler pressure,
200 lb., 100 deg. superheat, acting on a regulating valve
which controls the .-team supply to the turbines. The
difference in speed between the turbine and fan is due to a
set of 4 to 1 reduction gears composed of a pair of
double-helieoidal gears and flexible couplings, Fig. 8.
As the stokers are driven by a series of chain drives, the
feeding of the stokers and the speed of the fans are
regulated by the steam pressure and operate in unison.
The position of the fans is shown in Fi«-. 3. Space has
been provided for a future fan outfit.
At the back of each row of boilers, and between them
and the economizers, is a main smoke flue, 6 ft. 9 in. wide
and 10 ft. 6 in. high. One flue connects with two econo-
mizers, which receive gases from eight boilers. On the
opposite side of the boiler room the smoke flue of sis boil-
ers connects to a single economizer of the same size as
the others.
The induced-draft fans, of which there are two for
each row of boilers, are placed between the economizers
and the 12i/>-ft. diameter metal stack. The general
arrangement and a plan view of the boiler room are shown
in Fig. 4. One of the engine-driven fans is shown in Fig.
9. Each of the four fans is designed to handle 140.000
en. in. of gas at 500 deg. F., against 1%-in. suction.
Fig. 5. Old Boiler Room
Fig. 6. New Boiler Room
March 16, 1915
PO YY E i;
361
Fig.
Turbo-Driven Forced-Draft Fax
The normal volume of air handled is considerably less
than that mentioned. The fans are on the ground floor of
the boiler room. Their bearings are water-cooled.
As there are three economizers used in connection
with the 14 boilers, the average is 8330 sq.ft. of boiler
heating surface to one economizer. The boiler pressure
being approximately 200 lb., the economizers carry about
50 lb. greater pressure. Each economizer has 624 pipes
in 52 sections, each 12 pipes wide. The pipes are 10 ft.
long between headers and are arranged in staggered rows.
In the other boiler room there are also three economizers
of 52 sections, 10 tubes in each.
The damper arrangement is such that if any battery of
two boilers be cut out of service, the gases from the others
will still go to the economizer. In case it is desirable
either or all economizers can be cut out and the furnace
gases bypassed to the stack. Although there are two
fans for six boilers, on one side of each boiler room
space has been reserved for another economizer and two
additional boilers.
Pumps
In both the new and the old boiler plants the pump
room is in the boiler-house basement. Figs. 10 and 11
show a view of each. In the old pump room there are
three 12&20xl2xl8-in. duplex pot-valve, boiler-feed pumps
which supply the turbine glands with water. In the new
pump room there are two boiler-feed pumps of the
same size as the others, and two 8x8xl8-in. duplex pumps
for supplying gland water to the turbines.
Fuel Suppli
There are two sources of coal supply — by rail and by
water. Barring delays, the fuel is delivered in barges to
a wharf, hoisted by a clam-shell bucket and discharged
into a coal crusher, from which it is loaded into two 2y2-
ton cable-drawn cars. These cars are hauled up the single-
track runway. Fig. 12, and discharge the coal into the
bins at the turbine-room end of the boiler house. At the
opposite end of each boiler room is a second bin, sup-
plied from cars which discharge into an underground hop-
per and crusher from which the coal is elevated to the
bins hv a bucket conveyor.
In case there i- no available coal supply from the rail-
road, the hunkers can be Idled by loading the 5-ton larry
ear used ordinarily to supply the stokers from the other
coal bunkers and discharging its contents into a chute
leading to a hopper above the conveyor. Tims, the supply
of coal in the bin not reached by cable ears is maintained.
An ingenious track arrangement permits of the cable
cars passing at a turnout on the runway. This is
made po>>ible by the use of outside- and inside-flanged
carwheels. A glance at Fig. 13 shows how the cars
take the rails. One ear has the inside-flanged wheels
k- -7\3- >J
Fn;. s. Diagram of Fax Unit
and the other car outside flanges. Fig. 12 shows the
cars about to pass at the turnout. This arrangement re-
quires but a single track and reduces the construction
cost of the trestle.
From the bins the coal is discharged into the larry
scales, where it is weighed and then run along the track
Fig. 9. Engine-Driven Induced-Draft Fan
362
POW EE
Vol. 41, No. 1J
above the stoker hoppers. Five men handle all the coal
consumed in the plant. Two are at the hoisting tower, one
above the coal bunkers and one man in both boiler rooms
to handle the barney ears.
Ashes from each stoker fall into a brick-lined hopper
under which a ear is run to receive its load, which is
loom and conn.', ting the main steam line at the loop end.
A study of the piping scheme shows its simplicity, al-
though provision has been taken to insure continuity
oJ service.
While the addition to the plant is practically a
separate power plant in itself as applied to the steam end.
Fig. 10. New Pump Room
Fio. 1 1. Old Pump Room
drawn out into the yard by a small storage-battery loco-
motive and dumped for filling-in purposes.
Piping
An end elevation of the new boiler room is shown in
Fig. 14. which with Fig. 1 presents the details. Each
boiler is connected by an 8-in. bram h pipe to the main 10-
in. header. The header is constructed on the loop plan
and so valved that any two boilers and their section
of header may he cut out of service without interfering
with any other units. The headers back of the two rows
the new boiler room is connected to the old by a 10-in.
. ross connection, which is connected with the 15-in. cross-
feeder in the turbine basement.
The 10,000-hp. feed-water heater for each boiler plant
is in the basement and is piped to the boiler feed-water
pumps by a 12-in. pipe having a 7-in. branch pipe to
each pump, which discharges into a 9-in. main connect-
ing with the economizers. From the economizers the
9-in. feed line forms a loop along the front of the boiler
and supplies them through 3%-in. branch line-.
All boiler hlowoff pipes are in a tunnel under the main
Pig. 12. Single-Tback Runway Using Double-Cab Service
of boilers drop to a to-in. cross header in the turbine-
basement. From tin- a 10-in. lead is run to each of
the new turbines. This piping is shown in Fig. 2.
The 6-in. auxiliary header has three sources of steam
supply. It is also designed on the loop plan, tapping otf
from each of the 15-in. vertical header pipes and also
from the 10-in. end of the main steam loop in the boiler
. The auxiliary steam line supplies the condenser
turbines through 3-in. pipes. The exciter turbine re-
- it- steam supply through a -i-in. pipe connecting
with that section of the 6-in. header running to the pump
smoke flue. The blowoff main for the economizer is also
in this tunnel.
As in most large power plants, the pipe lines are desig-
nated by colors. In the Cos Cob plant the- pipe-line color
scheme is as follows: White — high-pressure -team lines:
red — Holly return system; yellow — auxiliary exhaust and
all low-pressure drips; black — boiler-feed lines: blue —
all water pipes other than feed and fire pipes: gray — fire
protection: dark green — air pipes; light green — crank-
case oil piping; pink — cylinder oil piping; brass, no
paint — turbine oil piping.
March 16. 1915
P OWE K
363
As is now the general practice in modem power plants,
all of the electrical-control apparatus is at one side
of the turbine room. A gallery runs the length of the
building and at one end is the chief engineer's private
office, the general office and switchboard room (Fig. 15).
On the same level are the remote-control oil switches
(Fig. 16). Below, in suitable compart-
ments, arc the duplicate busbars. At
the hack of the station, a general view
of which is shown in Fig. IT, is a trans-
former house in which arc six 7200-
kv.-a. auto-transformers, which raise
the voltage from 11.000 to 22,000 volts,
the center point of the transformers
being connected to the rails.
Fig. 18 is a diagram of the pres-
ent system of distribution. Line auto-
transformers are arranged along the
brack and are similarly connected for
reducing the voltage to 11,000 for
the locomotives. The center termin-
al of the outdoor transformers is con-
nected to the rails, one terminal to
the contact wire and the other to
the feeder wire. This arrangement
breaks the line into short lengths. Ref-
erence to Fig. 18 shows that a train
draws its current from the transformers on either side of
it. If the train is midway between transformers half of
the current will complete its circuit through the rails
and ground in one direction, and the other half through
the current supply balances regardless of which trans-
former the larger amount is taken from.
The changes from the old to the new system were con-
siderable, because the transition had to be made without
interfering with the operation of the train service, making
necessary many temporary connections and the perfecting
Fig. 13.
Teack ami Turnout Arrangement foe Cable-
Prawn Cars
of details which would allow of a rapid and easy change-
over when the final connections were made.
When it is considered that about 350 miles of track
is electrified it is seen that it was important that each
EL III VJ
ZROSS fISH TUNNE!
W///WM/WM
Fig. 14. End Elevation of the New Boiler Boom
the rails and ground in the other. When the train is
nearer to one transformer than another it will receive
the greater part of its current from the nearest one and
the smaller part from the distant transformer. Thus
man along the line should know what to do and when to do
it. At some points the changes consisted of merely dis-
connecting a few wires, and at others many changes were
essarv. As the final work was done at 'night, team
364
P 0 W E 1;
Vol. -11, No. 11
stilti
Pig. 15. Control Room wtttt Switch and Bench
BOARDS
Pig. 16. Aisle between Remotely Controlled
Oil Switches
^3MMT74B[
' Bra ■
'V&> V
1 ! ^^sS
Jrwy
J 1*
gJHf
1 / ^£W2$W
wSantt:
•^wV^riritfB^uJuvTvS
vjUJMHdl
-; I i ♦WT.iSjKS
Wt^?j
Fie. 17. General View of the Station
work of the highest order was imperative amil a mis-
take would mean delay.
But four hours, from 2 to 6 a.m., w< re available for the
final change-over. At 2 o'clock the power plant was shut
down, and all concerned were notified. Within two min-
utes the load dispatcher received the first '"ready" re-
port. This was quickly followed by others and within TO
minutes from the start the last report was in and all work
on 350 miles of track had been finished.
The power-house changes required longer, but at 3: 21
a.m. the plant was ready to start up under the new sys-
tem. At 4: 4-5 a.m. every part of the system was reported
ready for service and at 5 : 25 the first train received cur-
rent by the new system. At 5 : 3 1 the operating depart-
ment was advised that full normal service might be re-
sumed.
The entire work of addition and reconstruction of both
the power plant and lines as herein described was per-
, ^-"y
Sectional/zing
Auto-transformers ■
Pig. is.
Diagram of the New System of Electri-
fication
formed by the Engineering Department of the New York,
New Haven & Hartford l!.Ii.. and the plans for the en-
tire work were prepared by Westinghouse Church Kerr
& Co.. to whom the author is indebted for line drawings
of the power-plant addition.
principal equipment of the cos cob power plant addition
No. Equipment Kind
4 Turbo-generators Horizontal . .
4 Condensers Leblanc, jot.
4 Turbines Single-stage
1 Turbine Horizontal
2 Generators Direct-current.
2 Motors Induction
2 Generators Direct-current
2 Turbo-generators Horizontal
With 5O0O-kw turbines
Condenser pump drive .
125-kw. . Driving exciter generator
125-kw Exciting main generators
100-kw.
125-kw
130-kw
Driving exciters
Exciting main generators
Signal service
1 Motor-generator Direct-t
,-cted 500-hp.,450-kv.-a.. Signal:
14 Boilers Bigelow-Hoirnsby. 6250 sq.ft. heating
surface. Steam generators
14 Stokers Taylor Seven-retort ... With main boilers
It Superheaters.... Foster. With main boilers
3 Turbines Single-stage 215-hp Driving IL'-in l.i
3 Fans Up-blast-multivane 42-in Forced-draft
3 Engines Slide-valve Driving induced-draft far
3 Fans Encased.. 12-ft. diameter. Induced-draft.
3 Economizers. . Sturtevant S33 sq.ft. heating
surface Willi Bigelow boilers. .. .
2 Pumps Duplex-pot-valve . 12&20xl2xl8-In . Boiler feed
2 Pumps Duplex SxSxlS-in Water to gland on turbine
Operating Conditions Maker
ISO lb. steam, 100 deg. superheat, 1500
r p.m., 1-phase, 25-cvcle, 11,000 volt Westinghouse Companies
28-28J-in. vacuum Westinghou-e Machine Co.
180 lb. steam, 100 deg. superheat. 680
r.p.m Westinghouse Machine Co.
180 lb. steam, 100 deg. superheat De Laval Steam Turbine Co.
750 r.p.m , lLVi volts Westinghouse Electric & Mfg Co
4S0 r.p.m, 440 volts Westinghouse Electric ,v Mfg. Co
4S0 r.p.m.. 12.3 volts Westinghouse Electric & Mfg. Co
3G00 r.p.m., 23(1(1 volts, single-phase,
flUevelos Westinghouse Companies
72(1 r.p.m., 2300 volts, three-phase, 60
cycles Westinghouse Electric & Mfg Co
1 SO lb. steam, forced and induced draft . Ri
Driven by forced-draft turbines At
iihi deg. superheat Po
L801b steam, variable-epeed D«
Turbine-driven, with reduction gears B
180 lb. steam, variable-speed. . Sk
Engine-driven, variable-speed R.
With flue gases. . .
\ utomatically controlled
I \.[i-1:nit-speed. :illt omatieul I v
trolled
Co.
ering Co
F. Sturtevant Co
Sturtevant Co.
en Steam Pump Co.
Wilson-Snyder Mfg. Co.
March 16, 1915
P 0 AV E E
;;i,:
M»is&tfc&iiin\iiiragg Mlglhi IirasuslsittioKa
IR,esIstLsiEace
By H. Jr. McLellan
AVhere electrical machinery is subjected to fumes, as
aometimes when located in gas-engine stations or near
chemical plants, it is necessary that special precautions
be taken to insure the insulation resistance being main-
tained at a high value. Deposits of carbon and copper
dust, dirt, or chemicals will often be found on the wind-
ings of apparatus operated under these conditions. These
ire conductors and, consequently, lower the insulation re-
Bistance over the surfaces, making the current likely to
creep from exposed live metal parts to the core, and so
cause a burn-out.
Ordinarily, the deposit appears not to attack the insu-
lation, and the only thing necessary to prevent trouble is
to clean the machine at frequent intervals, testing its
condition by leadings of insulation resistance. In order
that the surfaces may be readily cleaned, they should first
have a good smooth finish, such as is obtained from
Beveral coats of varnish. Most machines have this finish
when sent from the works, but under certain conditions
it may become rough, and then it is necessary that the
bindings be revarnished.
The insulation resistance is most readily measured
with a megger, or if this is not available, a high-resist-
ance voltmeter may be used in the following manner:
First, read the voltage across the line; then connect
the voltmeter in scries with the insulation resistance (be-
tween a commutator bar and the shaft) and read the volts
avain.
If R is the resistance of the voltmeter, V the reading of
the voltmeter across the line, and V1 the reading in series
with the insulation, then the resistance of the insula-
tion is
R, =
The resistance of the voltmeter is usually marked on the
back of the instrument or on the carrying case; if not, it
may be obtained from the makers.
When the insulation resistance of a machine shows a
value of less than 250,000 ohms, this indicates that the
windings are covered •with dirt, and steps should be taken
at once to clean them thoroughly. The best method is to
thoroughly blow out the machine with compressed air.
After this measure the insulation resistance. If it has
reached a high value, say not less than 2 megohms, it
indicates that the insulation surfaces are in good condi-
tion, but if little improvement is noted, thoroughly wipe
all parts of the machine with a soft cloth and take insula-
tion readings at frequent intervals during this opera-
tion, with a view to determining where the greatest im-
provement is effected. AYhen the resistance reaches a good
value, say not less than 2 megohms, the windings should
be thoroughly sprayed with a good air-drying varnish. It
is useless to spray the machine while covered with dirt,
with the insulation resistance low; in fact, if this is done,
it will he impossible to remove the dirt after it is coated
with varnish, and the machine may have to be completely
reinsulated.
AVhere compressed air is available, the best method for
applying the varnish is as follows: Procure a length of
i/^-in. rubber tubing, say about 3 yd., and near one end
fit an ordinary gas tap, as shown in the sketch, leaving
about 3 in. of pipe from the tap. In the other end fit a
tundish, then tie the paint tube on top of the air pipe.
Varnish is poured into the tundish and will flow down
the pipe, the supply being regulated by the gas tap.
As it tries to pass the end of the air pipe it will be blown
into a fine spray, which can be directed to the desired
spot. The machine should stand for at least twelve hours
after varnishing to allow for thorough drying.
In general it is desirable to give the machine more than
one coat of varnish, and where the surface of the insula-
tion is very rough it may be advisable to apply as many
as four coats. These may be applied one after the other,
allowing sufficient time between applications for the ma-
chine to dry, or they may be applied at convenient inter-
vals. In the latter case, the machine must, of course, be
thoroughly cleaned before each application. The point to
keep in mind is that if the machine is to be easily cleaned
there must be a good smooth finish on all surfaces over
which the current is likely to creep, and this surface must
be cleaned at frequent intervals.
V
Rubber Tube -77'
Device fob Applying Varnish
In dealing with direct-current apparatus, especial at-
tention must be given to deposit forming on the under side
of the armature coils between the commutator necks and
the core, and on the mica between the commutator necks
and the V-ring. Consequently, in cleaning such ma-
chines, these parts and the ihsides of the machines behind
the commutator should receive particular care. A soft
tape should be threaded under the armature coils, one at
a time, and worked back and forth until all deposit is
removed, especially from the corners where each coil
leaves its slot.
Alternating-current apparatus is in general not likely
to show a decrease in insulation resistance after running,
as in alternating-current machines there are seldom any
exposed live surfaces except collector rings, brush gear,
etc., but the machines generally, and these parts espe-
ciallv, should be carefully cleaned at frequent intervals.
Si
A New Canadian Periodical — "Mine. Quarry and Derrick"
is the name of a new fortnightly magazine "devoted to the
development of the mineral resources of Western Canada."
The first issue made its appearance under date of Feb. 3,
1915, and it is promised by the publishers, Laurence & Wil-
liam, of Calgary, Alberta, to reappear "every second Wednes-
day." The staff consists of J. C. Murray, editor; W. C. Mc-
Ginnis, associate editor; R. W. Coulthard, contributing edi-
tor, and L. S. Kempher, manager. In the salutatory the in-
tentions are declared to be to give real expression to the needs
of the great Canadian West; to discuss the technical and
other problems to be met; to correct errors and misconcep-
tions, and, above all, to give the investing public the truth
as to present conditions, all as relating to the fields of oil
production, metal mining, coal mining, quarrying and the
manufacture of cement and clay products.
366
POWER
Vol. 41, No. 11
it<
Mai Fadden
SYNOPSIS — Points mil the advantages of the
plate nil re anil explains the construction and oper-
ation of several of the most widely used make*.
By the use of plate valves, a much higher piston or ro-
tative speed is possible. Heretofore, the speed of air
compressors has been limited by the air valves, as abnormal
wear and breakage of valves resulted when the piston
speed exceeded 500 ft. per min., caused by the excessive
weight and high lift. The mechanically operated Corliss
inlet valves have the disadvantage of semirotating surfaces
which require positive lubrication and are liable to stick
and cut. A complicated valve-gear is also employed,
which requires adjustment at frequent intervals.
One of the principal advantages of plate valves is in-
creased efficiency, due to the light weight of the valve
proper and light initial tension of the valve springs, al-
lowing the air in and out of the cylinder with small power
consumption by the valves. With a light valve and low
INLET AND DI5CHARGE VALVE
valve "b" keeper "a"
Fig. 1. The Borsig (German) Valve
spring tension the minimum pressure is required to keep
the valve open throughout that portion of the stroke in
which it is operating. Another advantage is the low lift
which, combined with lightness, reduces the momentum
attained on opening, insuring quiet operation and little
necessity of cushioning mechanism. The air is admitted
to the cylinder in a constant stream and at lower tem-
perature and higher pressure than where the ordinary
chattering high-lift poppet valves are used. The valves
are silent in operation up to the hignest speed, which dem-
onstrates the absence of hammering and fluttering, and
reduces wear of the valve and the valve seat. The cost
of repairs with the standard makes of plate valves is small.
The higher safe speed of compressors using plate valves
means a reduced cost of installation, not only of the com-
pressor unit, but of the building and foundation, since a
compressor for a stated capacity, equipped with plate
valves and operating at high speed, requires approximately
two-thirds the floor space taken up by a slow-speed com-
pressor equipped with the old-style poppet valves. In
the case of motor-driven units high speeds mean the ad-
ditional advantage of smaller and less expensive motors.
m ifiri
discharge valve
Another German Valve
To sum up. the principal advantages of the use of
plate valves are as follows:
1. Improved mechanical and volumetric efficiency over
the old-style poppet valve.
2. Minimum wear; cost of repairs reduced to a negli-
gible amount.
3. The valve requires no lubrication.
4. Silent operation at the highest piston speeds.
INLET AND DISCHAR&E VALVE
SPRING AND VALVE B
keeper'a"
Fig. 3. Mesta Machine Co.'s Plate Valve
5. The air end is simplified, owing to the elimination
of all complicated valve-operating mechanism.
6. Dependable and efficient at high 'speeds.
7. Floor space and cost of installation reduced on
account of greater capacity of smaller units due to high
speed.
8. Continuous operation under severe conditions.
Prominent American builders of large and niedium-
sized compressors have adopted the plate valve for use in
March 16, 1915
P 0 \Y E R
36?
their compressors only within the last two or three years.
Conditions were ripe for the innovation, because of
keen competition by foreign manufacturers, who have
employed the plate valve with success for some years.
In the following description of plate valves only those
of standard Continental and American construction will
be discussed. They may, however, be taken as represen-
tor
INLET VALVE DISCHARGE VALVE
Fig. I. Valve Used \:\ the Curtis Manufacturing
Co.
tative for the whole development along this line, since with
|. u exceptions, they follow closely the original German
lesign.
Fig. 1 shows a section elevation and plan view of the
Borsig valve, manufactured by A. Borsig, Berlin. The
valve consists essentially of a thin sheet-metal disk of
light weight, and is made to form two spiral arms
VALVE B GUARD OR KEEPER "A"
Fic 5. The Roglek Plate Valve (Ingersoll-Rand
Co.)
sei ured at the center of the valve by two studs, one in each
arm; a small movement of the valve arms is allowed on
each stud, depending on the lift of the valve. Above
the valve disk a keeper or stop is provided, in which a
large helical spring is seated. This spring serves to load
the valve and press it firmly on its seat. The point of sup-
port of the arms is located in the center of the valve lift
so that the disk is bent upward when the valve is opened,
and owing to the small mass of the valve proper, its inertia
is negligible. The construction of this valve is such that
it may be used for either discharge or inlet.
Fig. 2 shows a plate valve used by the Zwichauer Mu-
schinenfairik Aktiengesellshafi Zwichau, Saxony, one
of the large compressor builders of Germany. The valve
complete consists essentially of six pieces. The seat is a
circular iron casting having either one or two ports. The
keeper is a simple iron casting having ports cored through
to allow the passage of air from the inner edge of the valve.
The valve spring is of the helical type of rectangular sec-
tion, allowing a much more compact arrangement where
fully compressed than a spring of circular section. The
valve keeper is provide'd with a recess of sufficient depth
to accommodate the spring when the valve attains its
greatest lilt. The valve proper consists of a thin disk
stamped from sheet steel, being centrally guided by pro-
jections on the valve seat. The valves are not inter-
changeable for inlet or discharge.
Fig. 3 shows the construction of the Mesta automatic
plate valve, manufactured by the Mesta Machine Co., of
Pittsburgh, Penn., under the Iversen patent. The valve
Valve A"
<juide on Keeper
INLET VALVE
D1SCHAR6E VALVE
Fig. 6. The "Simplate" Y.u.ve (Chicago Pneumatic
Tool Co.)
proper consists of a light, thin, annular steel plate, guided
by a flat volute spring. The spring is permanently fast-
ened to the valve plate by prongs or clips bent over the
outside edge of the spring. The valve lifts parallel to the
seat and employs no guiding surfaces or guide pins. The
valve seat is a circular iron casting having one or more
annular ports. The valve keeper consists of a thin plate
i'f steel, with punched ports or recesses provided to allow
the free passage of air from the inside of the valve.
Fig. -f shows the details of the inlet and discharge valves
made by tile Curtis Manufacturing Co., of St. Loui^.
Mo. The valve proper is a thin disk stamped from sheet
steel. The valve seat i> of phosphor-bronze, having in-
dependent ports or cored passages for the flow of air. The
inlet ami discharge valves arc of independent design, hut
are not interchangeable. The inlet-valve keeper is of
steel and provided with a suitable recess to accommodate
the valve spring. The valve complete is held in a pocket
in the cylinder head by a flat-head stud. The discharge
valve proper is screwed into a tapped hole in the air-cylin-
der head. The spring is held in a pocket and a seat is
provided in the cylinder head to act as the valve keeper or
buffer. These valves, due to their thin construction, per-
mit the passage of air around the outside edge only, as the
valve is guided on a circular projection at the center of the
valve seat.
Fig. 5 shows a section of the TJogler plate valve, built by
368
P 0 \Y e i;
Vol. 41, No. 11
the Ingersoll-Rand Co., and which is essentially of Ger-
man design. The valve proper is made of special steel,
treated, tempered and ground. Narrow, integral spring
arms, ground to about half the thickness of the valve
proper to give them elasticity, are located at the middle
portion of the valve. These arms art as a connecting
means between the fixed and moving parts of the valve,
holding the latter in one position and seating it always in
the same plaee on the valve seat. The valve seat is of spe-
cial material, cast with circular ports. The keeper is a
special casting provided with tour spring pockets to ac-
commodate the four main valve springs which hold the
valve on its seat against the slight tension of the integral
valve arms. A cushion plate, fixed at the center only and
having a certain amount of elasticity, is employed to cush-
ion the valve at the point of full opening. It will be noted
by referring to the cross-section that a washer is placed
between the valve proper and the valve seat and between
the cushion plate and the valve proper. All parts are
kept from turning by a dowel pin and are clamped to-
gether by a through bolt.
Fig. 6 shows the "Simplate" valve, designed and built
by the Chicago Pneumatic Tool Co. The seat is of spe-
cial material east with one or more circular ports, depend-
ing upon the size of the valve. The valve proper in the
one-ported valve consists of a thin plate, or ring, stamped
from sheet steel, heat treated and tempered, then ground
to present a true surface on the seat. The multi-ported
valves of larger size have two or three distinct and separ-
ate valve di>ks. operating independently of each other.
These disks are similar to the one used in the one-ported
valve, as described above. The valve keeper on the inlet
valve is of special cast steel with suitable ports arranged
to allow the now of air from the inner valve disks. The
discharge-valve keeper is of cast iron, provided with ports
similar to the inlet-valve keeper. Both inlet- and dis-
charge-valve keepers have drilled recesses for the accom-
modation of the valve springs. Plain, small, helical
springs of light tension are employed on the inlet valve,
while on the discharge valve, springs of slightly greater
tension, together with buffer or cushion springs, are used.
All springs are galvanized to resist the corroding action
of the moisture in the air. Valve seat and keeper are
held together, in the case of both inlet ami discharge
valves; by a centrally located stud and castle nut, as
shown.
>teainni C
By Frank G. Philo
SYNOPSIS — Interesting cost ilata of a boiler
plant for a large manufai turing establishment.
The value of steam-cost data depends primarily on the
accuracy with which the coal and steam are measured and
the care with which the labor and all operating records are
kept. This being the case, it will probably not be amiss
to go into detail as to the methods used in obtaining the
following data.
Coal Weighing and Analysis
The fuel burned is a mixture of No. 3 buckwheat with
about 10 per cent, soft coal. To obtain the total weight
of coal consumed as well as the proportions of the two
coals mixed, the following method is used. The hard
coal is weighed as received in the railroad cars, on care-
fully tested track scales which check within 10 lb. with
standard weights. The hard coal is then dumped into a
machine which mixes it thoroughly with the crushed soft
coal. The mixture is carried overhead by a conveyor and
dumped into cable cars of 2-ton capacity each. The
weight of the mixed coal is obtained by weighing the small
cars on a second set of scales at this point. From the
hard-coal weights and the weight of the mixture the total
weight used, as well as the percentage of each kind of
coal in the mixture, is obtained. The automatic mixer
is so designed that it can be adjusted to give any pro-
portions of the two coals desired. The cost of the mixture
is increased about one cent for each 1 per cent, of soft
coal added. The function of the soft coal is to act as a
binder for the small anthracite and to supply the neces-
sary volatile matter which assists materially in starting a
tire after cleaning periods. The soft coal also helps to
burn out the fires more thoroughly before dumping.
Analyses of coal and cinders are made daily. The
number of cars of coal which the sample represents, to-
gether with the road and car numbers, are entered on the
laboratory sheet. The average analysis for the month
is found by multiplying each analysis by the number of
cars it represents and dividing the sum of these totals by
the total number of cars used during the month.
The average analyses of the coal fired during the first
six months of 1914 were as follows:
Jan.
9 .27
2 4 IS
11.070
10,043
68.82
Feb.
9 05
23. S4
11.140
10.132
69.27
Mar.
8.72
24.09
1 1 . 1 .-ii l
10,178
69.29
Apr.
S 44
I'll Js
11,563
10.5S7
72 99
May
8.01
19.72
11,674
10.739
73.85
June
7.91
Ash ulrv baas)
B.t.u. (dry basis) .
B.t.u (as fired).. .
Combustible (as
fired)
24 . 22
11,051
10,177
69.79,
Feed-AVatei; Measurement
Feed water is measured by two venturi meters of 3000
and 4(loo en. ft. per hour capacity, respectively. The
adjustments of these meters are checked weekly and once
a month weight checks are run by passing water at work-
ing temperature and pressure through the meters into
carefully weighed tank cars, which are run alongside the
boiler house. These tank cars have a capacity of about
60.000 lb. of water. All tests are run for at least 30
min.. sci the personal errors in starting and stopping are
small. The errors of the meters were found to be practic-
ally constant for any given rate of flow. The average error
over the working range covered in practice was found and
a correction applied to the daily meter readings. The
average error of the meters was found to be about :^4
per cent. low.
March 16, 1915
POWER
369
All water blown from boilers and economizers, as well as
all water discharged in emptying boilers and economizers
for repairs, is subtracted from the water registered by the
meters. Tbis water amounts to from 1 to 2 per cent, of
the total water passed through the meters during the
month. The blow-down pipes from each boiler are pro
vided with plug cocks and valves. The blow-down head-
ers from cadi battery of boilers have gate valves. All
blow-down valves and lines are inspected daily to insure
against loss of water from boilers by leakage.
Records of Operation
Daily reports are made showing the weight of water
evaporated, the average rating developed by the boilers,
Eeed-water temperatures, steam pressure, economizer in-
let and outlet water and flue-gas temperatures, flue-gas
analyses, coal and cinder analyses and all useful infor-
mation regarding the operation of the boiler house.
All materials and supplies are kept in a main store-
room and can be obtained only upon presentation of a
dgned requisition from the foreman in charge. All labor
and materials used by other departments for repairs and
maintenance of the boiler house are charged against the
boiler house at the end of each month. Thus the cost
of labor and material furnished by the pipe, electric, ma-
chine and carpenter shops for work done in the boiler
bouse is always obtainable. In reporting materials used
all supplies amounting to $20 or over are itemized. Time
slips for all employees of the boiler bouse are filled out
by the foremen and are sent to the time keeper's office
every day.
Load Factob
The load factor of this plant is very high as the plant
is run at full load 2i hr. per day, and about 26 days per
month. During the shutdown periods about one-quarter
of the total rated boiler capacity is in service.
LOAD ON BOILERS
Jan. Feb. Mar. Apr. May June
Average b.hp. per hr.
(operating hr.) 7698 S070 7094 6341 6200 61.51
Average b.hp. per hr.
(total hr.) 7501 77S1 6357 5764 5878 5626
Average load factor (oper-
ating hr.) 116.6 122.3 107.5 96,1 94.9 93.2
Average load factor (to-
tal hr.) 113.7 117.9 96.3 S7.3 89.1 85.2
Total rated b.hp. of plant, 6600.
Average operating boiler horsepower = average boiler
horsepower developed per hour while the j)lant is in op-
eration.
Total average boiler horsepower = average boiler horse-
power developed during total hours during the month.
Operating load factor = load factor based on operating
boiler horsepower =
Operating boiler horsepower X LOO
66U0*
Total load factor = load factor based on total average
boiler horsepower =
Total average toiler horsepower X 100
6600
OPERATING COST OF EVAPORATING 1000 LB. WATER FROM AND AT
212 DEG. F., CENTS
Jan. Feb. Mar. Apr. May June
Coal and freight 10.64 10.38 10.76 9.62 9.82 9.67
Labor 2.60 2.56 2.81 2.89 2.99 3.12
Total 13.24 12.94 13.57 12.51 12.81 12.79
Operating cost per boiler
hp.-hr., cents 0.46 0.45 0.47 0.43 0.44 0.44
•Rated capacity of plant.
OPERATING COSTS AS PER CENT. OF TOTAL OPERATING COSTS
Jan. Feb. Mar. Apr. May June
Coal and freight 80,4 80 2 79.3 77.0 76.7 77 2
Labor 19.6 19.8 20.7 23.0 23.3 22.8
Jan. Feb. Mar. Apr. May June
Tonscoalused 12,331 11,145 10,450 8.392 8,865 8,136
Cost per 2000 lb. delivered $1.66 $1.68 $1.68 $1.64 $1.67 $166
Lb coal per boiler hp.-hr . 4.419 4.263 4.419 4.044 4.054 4 017
B.t.u. per lb. (as received). 10,043 10,132 10,178 10,587 10,739 10,177
Efficiency (boiler, econo-
mizer and furnace) . 75.5 77.6 74.4 78.3 76.9 81.1
Efficiency (boiler and fur-
nace) 69 4 71 2 09.0 72.6 71.4 74.2
Efficiency figures arc based on the total coal used dur-
ing the month, including that used for starting and bank-
ing fires, etc. The total water evaporated is checked
against the total coal fired. The gain in efficiency due
to the economizers is figured from the rise in the feed-
water temperature through the economizers.
OPERATING LABOR COSTS PER TON OF COAL FIRED, CENTS
Jan. Feb. Mar. Apr. May June
Handling coal 4.40 4.67 4.90 4.39 4.44 4.78
Firing coal.. 21.25 21.84 21.19 24 08 24.70 26.01
Bemovingasb.ee 3.26 3.28 3.38 4.02 4.24 4.46
General 11.63 11.64 14,44 16,59 17.42 18.26
Total 10 54 41.43 43.91 49.08 50.80 53.51
INDIVIDUAL COSTS AS PER CENT. OF TOTAL COSTS
Jan. Feb. Mar. Apr. May June
Coal and freight 75.9 75.0 75.2 714 69.6 70 1
Operating labor 18 5 18 5 19.7 21.3 21.2 22.6
Maintenance labor 1.1 07 0,9 1.6 1.1 1.2
Maintenance material ... 4 5 5.8 4.2 5.7 8.1 6.1
TOTAL COSTS OF COAL, MATERIAL AND LABOR, DOLLARS
Jan. Feb. Mar. Apr. May June
Coal and freight. . 20,469.46 18,723.60 17,550.00 13,762.88 14,804.55 13,505.76
Operating labor. . . 4,998.98 4,617.37 4.5SS.59 4,118.79 4,503.42 4,353.57
Maintenance labor 298.03 171.59 213.S9 307.28 238.90 23X.4II
Material 1,204.68 1,437.33 972.49 1,100.50 1,725.73 1,179.32
26,971.75 24,949.89 ^.i.:«0.97 19,289.45 21,272.60 19,277.05
DIVISION OF LABOR, BOILER ROOM
6 a.m.-O p.m., Day Shift 6 p.m.-6 a.m., Night Shift
Foremen 1 — 12 hr., $3.25 1 — 12 hr., $3.25
Water tenders 1 — 12 hr., $2.75 1 — 12 hr., $2.75
Ashmen. 3— 12 hr., $2.16 3— 12 hr., $2.16
Repairmen 11— 10 hr., $2.16 1— 12 hr., $2.16
Firemen 16 — 12 hr, $2.75 16 — 12 hr., $2.75
Coal handlers 7 — 12 hr., $2.16
Chief engineer 1 — 8 hr., salary
Efficiency engineer. . 1 — 8 hr., salary
41 men 22 men
Total 63 men
The boiler equipment consists of fourteen 300-hp.
B. & W. boilers ami si\ 100-hp. Edgar water-tube boilers.
All boilers are equipped with Green economizers. One
foot of economizer surface is provided for each two feet
of boiler-heating surface served. All boilers are hand-
fired and are equipped with Grieve grates and forced
draft produced by a 125-hp. Green fan. The grates have
about 8 per cent, air space. The ratio of grate surface to
heating surface is 1 to 30. The ash hoppers are of cast
iron lined with brick. Ashes are dumped into small cars
of one-ton capacity each and are pulled up an incline by
a steel cable and dumped into the railroad cars. Coal is
bandied and delivered to the bunkers by the Mead-Mor-
rison system of cable cars.
Foreigrn-Bullt Vessels Admitted to Amerirnn Registry —
Under the act of Congress of Aug. 18, 1914, the foreign-built
vessels admitted to American registry up to Feb. 19, 1915.
have numbered 129, with 468,509 gross tons, or 303,284 net
tons.
The Horsepower Constant is the number of horsepower
per pound of mean effective pressure developed by an engine
when running at its normal speed. It will be different for
different speeds. Knowing the constant, one need only mul-
tiply the mean effective pressure (obtained from an indicator
diagram) by this constant to know what indicated horse-
power the engine is developing. Evidently, by the definition,
the horsepower constant is all of the "PLAN" formula ex-
cept the P.
370
P (.) \Y E R
Vol. 41, No. 11
^initoiiRuij
By M. R. Bush
SYNOPSIS — Simple directions for making ca-
pacity lest* of centrifugal pumps.
Although the methods and apparatus to be described
are particularly adapted to testing small pumps, they
apply with limitations to pumps of large capacity.
Apparatus
The apparatus for measuring the quantity7 of water de-
livered by the pump is most important. Where available,
weighing tanks will prove most satisfactory for this pur-
pose. Usually, they are arranged side by side, and in be-
tween the two a hopper is so placed that the water may be
turned from one into the other without interrupting the
flow.
Each weighing tank should be of such capacity that it
Fig. 1. Partition to Obtain Uniform Flow
will accommodate as much water as will flow in at least
two minutes, and have a quick-acting delivery valve of
such size that the water can be let out of the tank in one-
half the time required to fill it. This will then give time
for closing the valve for the reception of the next charge of
water and for caring for any unseen delays that may
occur while the other tank is being filled. A satisfactory
valve for these tanks is a large gate valve in the floor of
the tank, operated by a steam or air cylinder on the out-
side and held to its seat by the weight of the water. This
form of valve may be easily opened or closed and the con-
trolling valves placed within easy reach of the man oper-
ating the scales. The scale beams should be so arranged
that they may be read from the same platform.
Another form of apparatus used to measure the quan-
tity of water is a single large tank fitted with a weir, as in
Fig. 1. The capacity of the tank should equal about five
minutes' discharge of the pump. It can be made of steel
(or wood lined with sheet zinc) and the plan dimensions
such that the length is two-and-a-half times the breadth.
The weir is placed in the end, not along the side of the
tank, and should extend the width of the tank to avoid end
contractions* of the water passing over the weir. A par-
tition running parallel with the weir and extending from
the top to within 2 ft. of the bottom divides the tank into
two compartments. Tbe water should come into the tank
on the side of the partition opposite the weir. This ar-
rangement will prevent a serious "velocity of approach"
of the water to the weir. If the tank is of wood, it will
be necessary to provide a strip of V4~m- or iVm- iron l°r
the weir, which may be either set into the wood or screwed
to the inside of the tank. The sharper the edge of the
weir, the better the results that will be obtained.
Still another form of apparatus for measuring the de-
livery of the pump consists of a large tank of rectangular
plan, from one end of which a wooden trough extends, as
in Fig. 2. This trough is inclined at an angle not to ex-
ceed ten degrees from the horizontal, and is of such .width
and depth that it will carry away the overflow from the
tank when inclined at the angle selected. The pitch of the
trough must not be too great, for this would mean a high
velocity through it, thus bringing about a large friction
loss. However, it must be inclined sufficiently to carry
away the pump delivery. If lined with zinc or copper
sheeting, the sides of the trough will reduce the friction
loss. Provision must be made for accurately measuring
the depth of water in the channel or trough and a current
meter for obtaining the velocity of the water in the chan-
nel is also necessary.
The water must start from the tank into the channel
with almost no initial velocity ; more accurate measure-
ments are then possible. To provide for this condition a
partition must be inserted across the short dimension of
the tank, as described in the tank with the weir.
The most common type of drive for the small centrifu-
gal pump is the electric motor. The connection to the
pump is often by a belt long enough to allow 10 to 12 ft.
from the motor-shaft center to the pump-shaft center.
The power input to the motor is measured by an am-
meter and a voltmeter if using a direct-current motor,
and by a wattmeter if using alternating current. In the
direct-current system the voltmeter is shunted across the
line at some convenient point near the motor and tbe am-
meter is placed in series with the armature circuit. In the
alternating-current system the wattmeter is placed in
'When water escapes to the atmosphere or from one vessel
to another through a "drowned" (submerged) orifice, or
whether it flows from an open channel or nozzle, the stream
will get smaller — contract at a certain distance from the
orifice; hence the term contraction.
Fig. 2. Rectangulab Weib with Trough
series with oue of the windings. The reading must be
multiplied l>\ three if a three-phase circuit is used. In
either system provision should be made to vary the speed
of the motor.
If it La possible to substitute a direct-connected motor
for the belt drive, better results will be obtained in that
it will be possible to measure the power input to the pump
more accurately. A convenient method is to insert be-
tween the motor and pump couplings a direct-reading
March 16, 1915
POWER
371
osmometer which records the horsepower upon a grad-
ted scale. However, this Ls a rather expensive apparatus
.1 is necessary only when great accuracy is required.
A strainer and check valve should always he placed on
e lower end of the suction pipe, Fig. 3. The strainer
11 prevent any large pieces of foreign matter being
awn into the pump. The valve will prevent the suction
£3.
Fig. 3. U-Tube fob Measuring .Suction* Head
head being lust, if the pump is shut down for a short time,
and will also assist in starting the pump.
To measure the suction head a mercury column, con-
sisting of a glass TT-tube a little more than half full of
mercury, is attached to the suction pipe as nearly as pos-
sible to the pump. A vacuum gage could be used for this
purpose and attached to the same place on the suction
pipe. A thermometer is needed in the well to determine
the water temperature.
To measure the delivery head a pressure gage is at-
tached to the delivery pipe near the pump. A throttle
valve placed in the delivery pipe near its discharge end
enables one to vary the pressure against which the pump
50 100 150 200 250 300 350 IOC
U.5 Gallons per Minute
Fig. 4. Horsepower-Quantity Curves
works. Two speed counters are usually provided, one
for taking the motor and the other for taking the pump
revolutions.
An opening in the pump casing is necessary to provide
for starting. This hole is fitted with a plug and should
be from 1 to l1/" in. in diameter.
Having provided suitable apparatus, there are two tests
that may be run — the constant speed and the variable
speed.
CoXSTAXT-SrEED TEST
This is the most valuable test because a centrifugal
pump is designed to run at a constant speed. Having
lillcd the pump with water through the hole in the casing,
open the throttle valve in the delivery pipe and start the
motor. When the pump is running at its normal speed
see that the throttle valve is vide open so thai only the
static head to the point of delivery and the friction head
in the pipe exist. This will be the condition of largest
capacity, smallest head.
The following readings are taken and repeated every
two or three minutes for the same conditions until five
are recorded, and for each new set of conditions : Voltage,
amperage (if direct current is used), wattage (if alter-
nating current is used), suction pressure, delivery pres-
sure, speed of motor, speed of pump, and the necessary
readings for determining the quantity pumped. One read-
ing of the thermometer will usually be sufficient during
the test, as the water temperature will vary slightly, if
any.
The delivery throttle valve may now be closed to some
extent to shut off the flow and correspondingly increase
the pressure. Readings are taken at every 5-lb. increase
Fig. 5. Showing the Proper Value of "H"
in the pressure to start with, and the interval may be de-
creased if found necessary when approaching the condi-
tion of maximum pressure, no quantity.
Care must be taken in starting the test when the valve
is wide open, not to overload the motor by pumping too
large a quantity. There are pumps with which it is im-
possible to overload the motor, as the motor horsepower —
quantity cum — is of a form shown in Fig. -4. If a con-
stant-speed motor is not being used, it will be necessary
to slow down the motor as the quantity decreases, as the
tendency will be to speed up the pump beyond its rating.
If the well from which the water is pumped is not of
sufficient capacity, the level will fluctuate somewhat, pro-
vided the weighing-tank method is used. This will be
noted only if the water pumped is let back into the well
after being weighed.
Before finishing the test the height of the center of the
pressure gage above the water level and also the height
of the point of attachment of the mercury gage above
this level should be recorded.
The following calculations will be necessary to convert
the readings taken into terms for plotting the curves :
Obtain from a table of the properties of water at different
temperatures the weight of a cubic foot of water at tin
temperature recorded. With this figure the number of
cubic feet pumped per second may be obtained from the
pounds per second, if the weighing-tank method is used.
372
P 0 W E K
Vol. 41, No. 11
-o
Motor
Pump
Weighing Tank
-a
s.
>£
t
^
o
s
A
as
3
a
d
£
£w
£
m
!
a
w |
TJ"
•a
3 ^
l.s
3
>
& 3
3"
.5
d
03
1
°.d
D.
1°
si
« -
*£
a
3
a
3
W
■a
a
X
:»
a
H
a
a"
Pert
jrmanee
at N R.j
.M.
Remarks
Discharge
i
^
Water Hp.
g
s
OS
h
a
s
o
§
■° a
B
!|
•J 1
1
a
X
3-~
z
h
*§cn
O
£>
W
£
S
Fig. 6. Form for Kecording Centrifugal-Pump Test Data
By the weir method of measurement the quantity may
be calculated directly by the use of Francis' formula:
Q = 3.33 bHi
in which
Q = Cubic feet per second ;
h = Width of weir in feet;
H = Height of water level above the weir.
Care should be taken that it is measured far enough
back from the weir so that the true height is obtained, as
in Fig. 5. An accurate method of obtaining height H is to
measure the level of the water by means of a hook gage
suspended over the center of the tank.
With the channel method of measurement the water
cross-section must be determined in some manner, and
this section in square feet multiplied by the velocity of the
water in feet per second will give the flow or discharge in
cubic feet per second.
Fig.
50 100 150 200 250 300 35(
U.S Gallons per Minute
Results of Speed Test on 12,000-G
Hour; Turbine Pump
The pressure head P in feet is obtained from the gage
pressure in pounds per square inch by multiplying the
same by the factor 2.31. The suction head in feet is ob-
tained from the suction pressure in inches of mercury by
multiplication by the ratio 17: 15.
The total head against which the pumps are working is
obtained by addition of the suction head, pressure head
and the vertical distance in feet between the center of the
pressure gage and the point of attachment of the mercury
gage. The friction head in the delivery pipe, the suction
pipe, the foot valve and strainer are accounted for by read-
ings of the pressure and suction gages.
The horsepower output of the motor, in the case of di-
rect current, is obtained from the product of the amper-
age, voltage and motor efficiency, divided by the factor 746.
The motor efficiency must either have been determined
beforehand by separate test or obtained from the motor
manufacturers. In the case of alternating current the
motor output is the watts input times the motor efficiency.
The belt loss is subtracted from the motor output to
find the true power input to the pump. This loss will de-
pend upon the condition of the belt texture, the tension
put upon the belt and the amount of slip. The variation
of the ratio of the motor and the pump speeds gives some
indication of the loss of power in the belt.
The water-horsepower exerted by the pump is obtained
as follows :
62.5 X QH _ QH
Water-horsepower =
550
where
Q = Cubic feet water per second ;
H = Total head on the pump in feet.
The efficiency of the pump is then the water-horsepower
divided by the horsepower input to the pump.
Fig. (! is a form showing the readings necessary and
the factors t<> he calculated. Fig. 7 shows the curves ob-
tained from an actual constant-speed test on a small tur-
bine pump of 12,000 gal. per hr. capacity. Without doubt,
it will be impossible to keep the pump at exactly a con-
stant speed, and to pint (he curves for constant speed it
.March 16, 1915
P O \Y E K
373
will !»' necessary to correct the readings of quantity, head
and horsepower by means of the following formula:
Q' = Q x A
N
IV = H X
HP' = III' X
where Q', IV ami ///" are the quantity, head and horse-
power at speed .V, which is the constant speed at which
the pump should run. and Q, H and HP are at the speed
N, the actual speed recorded while the readings are being
taken.
Vakiable-Speed Test
Such a test may he run when it is the desire to know at
what speed the pump will give the best efficiency ; in other
words, for what speed the pump was designed.
The apparatus used in the former test can be used in
this test. Commence at a speed somewhat below that
which has been judged to be the normal speed of the pump,
and with the valve wide open take readings of the power
input to the motor, speed of motor, speed of pump, pres-
sure gage, suction gage and quantity pumped. Take only
one set of readings, and then increase the delivery pressure
and take another set. Continue to increase the pressure,
taking readings at every change until the throttle valve
is entirely closed. Then open the valve, speed up the
pump 50 or 100 revolutions and take the same readings
as before with the same increases in pressure.
The calculations may be made by the same formula and
rules as formerly, but in plotting the curves it will be
necessary to plot only the efficiency curves to ascertain at
what speed the pump should lie run to work most econom-
ically. A set of such efficiency curves taken from a
test is shown in Fig. 1 . The normal speed of the pump
was 1650 r.p.m., at which speed, as shown, the best effi-
ciency was obtained.
One Thinjir to Remember is that if a man does not know,
he cannot be cussed into knowing;, especially if you have
only a short time in which to give him the treatment. A
better plan is to wait an opportunity, and not let it pass
when it comes, to talk with the man and do your best to
give him help by way of instruction and advice. — D. R. Mac-
Bain, before the Traveling; Engineers' Association.
V
Three-Metal Rr0n7.es — A description of the ternary metals:
Copper and tin with lead, zinc, phosphorus, manganese
and aluminum. Lead imparts plasticity to bronze, and di-
minishes hardness and temperature changes ("imparts a
lower mutual freezing point"). Microscopic examination
shows that the lead is distributed throughout the mass.
Segregation, to which bronzes rich in lead are liable, is
prevented by the addition of 1 per cent, nickel, sulphur
added as galena, phosphorus, or arsenic. A small addition
of zinc does not materially alter the structure of bronzes,
while ductility and tensile strength are slightly increased.
Bronzes containing zinc are more easily forged and cold-
rolled and are less readily corroded by sea water. Phos-
phorus may exist entirely as solid solution (up to 1 per
cent.) or as Cu3P: it greatly increases the hardness and
resistance to wear, while impairing the tensile strength,
elasticity and elongation. The maximum in commercial
bronzes is about 0.8 per cent. P, with about 8 per cent. Sn.
The valuable properties of manganese bronze are its strength
and noncorrodibility; commercial products often contain
more aluminum than manganese. True aluminum bronze
seldom contains more than 11 per cent. Al: it is useful in
casting, though it shrinks considerably. The addition of tin
increases its ductility. — "Journal of the Franklin Institute."
By A. D. Williams
A blowoff basin or tank is one of those details of a
power plant that often cause trouble. Restrictions are
frequently imposed regarding the discharge of steam into
sewers, and much steam is released where the blowoff
pressure becomes equal to that of the atmosphere. The
basin, Fig. 1, was designed for the East Fifty-third St.
station of the Cleveland municipal electric-light plant
and presents desirable features. It is constructed of plain
1:2:4 concrete, as it is buried in the ground. For use
above ground the design must be modified and strongly
reinforced concrete or steel plate used, the latter prefer-
ably.
This basin is designed to separate the steam from the
hot water by whirlpool action, the blowoff pipe entering
the basin tangentially, as shown in the plan section. The
l 2-1 Anchor Bolts,8 "long,
8 "Cast Iron _ - -* - J. serin Concrete
25%'C.toC
6 Blowoff
line
PLAN OF BLOWOFF BASIN
■4-%xlO Bolts
-t Lugs wrfh%'
" Boits,l2"lorg,
■ a lot each End
- • , -*' -.• z spaced
&c: befween
SECTION THR0U6H CI.
CORNER BAR (2 REQUIRED)
r* SJ9" -=H
p-.^-.-.-.-.-^K
8 "Cast Iron Pipe '
to Sewer
Standard Cast Iron
t Manhole *_
Surface of Oround
*\g.
DETAIL OFCOVER
FOR STANDARD
I1ANHOLE
(l REQUIRED)
section a- a
Section and Details of Concrete Blowoff Tank
concrete is protected from the action of the entering
stream by a •'*■ j -in. bent plate. In action the water has a
tendency to spread out on the walls of the basin, leaving
the center open for the escape of the steam released. This
action of the water explains the location of the cast-iron
waste pipe close to the wall, where it will commence to
take water to the sewer as soon as the whirling water cov-
ers it. The lip around the manhole and the curved top are
designed to prevent the whirling sheet of water from
spreading on the top and trying to climb out of the man-
hole. The curve and lip work upon the same principle as
similar parts of a steam separator, and throw the water
down into the tank.
To simplify the form work required in constructing
the tank, the top may be chamfered as indicated by the
dotted lines, tit one side of section .1.1. In building a
basin on this design the internal form is best constructed
of <l t steel, galvanized or plain, held in place by a
wnoilen skeleton built so that a man can work inside the
Form to place the concrete bottom of the tank. In this
way any scam between the walls and the bottom can be
avoided.
37-i
POWEB
Vol. 41, No. 11
The basin is designed to receive the blowoff from six
boiler.- with in. 134 sq.ft. of heating surface each. 1 1 de
sired, the inside diameter of the basin may be increased,
but it would be inadvisable to reduce the diameter, as the
blowoff water enters it at a high velocity.
An extremely hazardous method used by a wrecking
company to raze a brick chimney is shown in the illustra-
tion. This chimney was 6x6 ft. inside and 125 ft. high,
and belonged to an abandoned power
plant. Fig. 1 shows the method used.
The bricks were dug out one on side
and three jack-screws placed in the
opening; then those on the opposite
favored, even when it is desired that the chimney fall
within a small radius.
The whole circumstance furnishes a good illustration
of the rule-of-thumb method used by many contractors.
instead of making a few simple calculations. It is likely
that this same process had been successfully used before
on a small stai L therefore they supposed it would do for
all others, but a method winch proved entirely satisfac-
tory in handling a small stack might not be at all suc-
cessful for a large heavy one. Many serious accidents
have occurred in trying to adapt methods suitable enough
Fig. 1. Method Employed
Fig. 2
side and also back to the center of the chimney were
knocked out. The idea was to tip the stack over
with the jack-screws, but too much of the brickwork
had been dug out and the remaining bricks failed. The
result was successive failures which let the stack down
almost vertically, as shown in Fig. 2. The fountain-like
upheaval of bricks in Fig. 3 would make it appear that
the base was blown out from under the stack, but such was
not the case.
Fortunately, no one was hurt by the premature falling
of the chimney. There were two men on the scaffold
when it started to collapse, but they jumped down and
escaped from the danger zone. The top of the stack fell
only forty feet from the base. This method is not to be
in one case, but entirely inadequate in another,
he hoped that they will not experiment again.
Ocean Volume to Land Area — One per cent, of the con-
tents of the oceans would cover all the land areas of the
globe to a depth of 290 ft. — U. S. Geological Survey.
Two Causes for a Belt Not Running; True upon properly
built pulleys mounted upon correctly aligned shafting: The
belt may not have been made straight in the first place, or
the ends may not have been joined squarely. Otherwise
there may have been a lack of uniformity in the texture of
the hides from which the belt was made; belly leather to-
ward one edirr- and flank leather toward the other, and the
two stretching unequally.
March 16, 1915
P 0 W E R
375
Stop Acts Wlh\©ir& ES.©dl IBff-esiMs
The value of a dependable safety stop on a steam en-
gine was demonstrated a few days ago, when the piston
rod of a 23x36-in. Wright engine parted. The engine
was operating in the basement of the J. T. Perkins Co.'s
factory, Kent Ave. and Hooper St., Brooklyn, N. Y.
Fig. 1. Cylinder Head and Pieces of the Flange
The rod parted at the keyway in the crosshead, resulting
in the knocking out of a cylinder head, breaking the
flanged part into small pieces clean around the body
of the head, as shown in Fig. 1.
No one was injured, and the property damage was
slight. Fortunately, eight bales of camels' hair, weighing
about -400 lb. each, were piled in line with the cylinder,
and these received the head and piston as they were driven
from the cylinder, and undoubtedly saved the lives of
two operators who were working on a machine in line
with the cylinder.
The engine was running at a speed of 90 r.p.m. with
a boiler pressure of 125 lb. The piston rod shows on
the face of the fracture that the break for the most part
was old, the lighter surface at the right side of the right
Fig.
The Light Shading Indicates the New
FlJ.U'TURE OF THE PlSTON Roll
view of Fig. 2 indicating the new fracture in the metal.
The break was evidently caused by ordinary working
strains, the metal appearing to be of good grade.
When the rod parted, the Wright safety stop, which
is designed to operate with both high and low speeds,
threw the catch blocks on the steam valves out of action,
allowing the valves to remain closed and so preventing
steam from entering the cylinder.
Because of the prompt action of the engine stop and
the non-escape of live steam at boiler pressure into the
factory, damage to the goods was prevented and the pos-
sibility of a panic and loss of life was avoided.
v
IFLoss Exqpsur&siioia J©nm\.&
The illustration herewith shows an expansion joint, the
primary feature of which is that of guiding the pipe Line
so that it will be in alignment with that part of the piping
which is held rigid, and thus prevent the ordinary wear
and tear on packing experienced in slip-tube expansion
joints. This joint automatically permits a lengthening
or shortening of the pipe line to which it is applied up to
a. maximum of a 4-in. change of length without creating
strains or distortions.
Referring to the illustration, the flanges, which are at
each end of the joints, are of a size to permit of joining
with the pipe-line flange on the larger end, the flange on
the smaller end being bolted to a standard fitting which is
anchored, or to the pipe line that is properly guided and
anchored.
If it were not for the outer sleeve this device would be
nothing more than an ordinary slip-joint, providing lineal
Section through Boss Expansion Joint
play for expansion and contraction. The slip-joint sec-
tion, however, is of improved construction, as the packing
space is ample and the slip tube is made of bronze, so that
it will not rust in the packing.
The particular feature of this joint is the outside sleeve,
which introduces an effective and rigid guide. This sleeve
is cylindrical, machined on the inside and bolted to the
body. The companion flanges, which travel in this guide.
according to the amount of contraction or expansion of
the pipe line, are machined on their peripheries to secure
alignment, and wear of the packing of the slip joint and
sagging of the line at the expansion joint are avoided.
This prevents the tendency to leak and the joint will re-
main tight for long periods without adjustment of the
packing.
This type of joint is made for a pressure of 200 lb. per
sq.in., in all sizes up to and including 24 in. Each size
will accommodate 4 in. of travel for expansion and con-
traction, and if a longer traverse is desired, special joints
can be obtained.
This expansion joint is manufactured by the Alberger
Heater Co., Chicago and Granger St., Buffalo, N. Y.
iS
Idle Boiler* should be thoroughly washed out and dried.
Trays with unslaked lime should be placed inside and the
boilers should be closed air tight. If the boiler is to stand
ready for immediate use it should be filled with water to
which burnt lime has been added, hut unless the boiler is
one of a battery and is kept warm, it is likely to condense
atmospheric moisture from outside and corrode if filled with
water. — Exchange.
376
P 0 AY E E
Vol. 41, No. 11
urn imiueinnic
Reference to the opposite page affords striking con-
trast between the internal-combustion engine of forty
years ago and the present highly developed product in
its special adaptations to various kinds of service. The.
two upper views represent the machines exhibited at the
Centennial Exposition at Philadelphia in 1876, and
among the rest are some that will be seen at the Panama-
Pacific Exposil i "ii.
AYhile the first attempts to produce an internal-com-
bustion engine date back to the latter part of the eighteenth
century, when gunpowder was used as the energy-produc-
ing medium, little was accomplished until 1860, when
Lenoir placed on the market the first practical engine.
This was horizontal, double-acting, and the cycle was
patterned somewhat after the steam engine, the charge
being drawn in during the first half of the stroke, ig-
nited, and expanded during the latter half, then expelled
on the return stroke. Owing to its extravagant use of
gas, however, the Lenoir engine did not meet with much
success.
The next engine to attract popular attention was the
Otto and Langen, brought out in 1866. This was en-
tirely different from the Lenoir and embodied the atmos-
pheric free-piston principle. It consisted essentially of
a long cylinder open at the top and containing a piston,
the rod of which carried a rack. By means of a spe-
cial clutch and pinion this rack was made to engage
with the flywheel shaft on only part of the down stroke
and that part of the up -stroke during which the charge
was being drawn into the cylinder. The operation was
essi ntially as follows :
The mixture was drawn in for about one-sixth of the
cycle) which was destined to revolutionize the gas-engine
industry. It was the first gas engine to use compression
and in principle formed the basis of the modern inter-
nal-combustion engine.
Just previous to this, however, in 1873, a Philadelphian
by the name of Brayton brought out an oil engine in
which the oil and air were mixed under considerable pres-
sure outside the engine and passed into the cylinder
through a fine-mesh wire screen, burning just beyond
it. the object of the screen being to prevent backfiring
into the port. The mixture was admitted for practi-
cally one-third the stroke and burned at a uniform pres-
sure. The inlet valve then closed and the heated products
of combustion forced the piston to the end of the stroke.
The exhaust port opened just before the end of the
stroke and on the return stroke compression was car-
ried to the pressure in the air and fuel tanks.
Engines of this type were built in sizes of 1 to 10 hp.,
and were extensively used, the chief troubles being back-
firing and the extinguishing of the pilot flame. Also,
the addition of compressors for the oil and air made the
installation somewhat cumbersome.
Without attempting to enumerate or describe the in-
termediate steps in the development of the gas and the
oil engine, associated with the work of Dugald Clerk,
Dr. Diesel and others, we will pass to a consideration of
some of the present-day types. The familiarity of the
reader witli the principles of operation involved and their
general construction makes a description unnecessary,
hence, space will be devoted only to certain comparative
features, some of which are included in the following
tabulation :
COMPARATIVE FEATURES OF DIFFERENT TYPES
Type Cylinders
Otto Single, single-acting, 0 in.
x 5 ft. 10 in 3
Brayton Double, tandem, vertical,
6x9-in
Automobile 6-cycle, 3?x5-in
Aeroplane 8-cyl., 5x7-in
Farm Single
Blast-furnace gas Twin-tandem, 44xf.ll
Weight
Weight per Horsepower
Fuel Consumption
35 hp. at ISnO r
200 hp. at 1700 i
6 hp. at 350 r.p.i
5M0(i hp. at S3 J i
Diesel 4-cyl., 19x24J-m 500 hp. at 200 r.p.m. . .
stroke and was then ignited by a naked tlame, whereupon
the rack disengaged from the pinion and the piston was
projected upward: the latter part of the stroke, after
the gases had expanded and cooled, being due to the
inertia of the piston. On the downward stroke the rack
engaged the pinion ami the weight of the piston, aided
by the atmospheric pressure on its upper side, performed
useful work and stored energy into the flywheel. As the
pressure of the eases below the piston increased above
the atmosphere, they were slowly expelled from the cylin-
der and the speed of the piston decreased. At this point
the pinion disengaged, only to engage again at the begin-
ning of the up stroke fc.r drawing in the next charge.
The admission of the charge, ignition and exhaust were
controlled by eccentrics and there were about 20 strokes
per minute.
The engine was essentially limited in output and a
great drawback was its irregular and extremely noisy
operation. This led Otto to bring out, in 1876, a new
engine operated on the four-stroke cycle (Beau de Rochas
2S eu.ft. coal gas per hp.-hr.
About 2 lb. per hp.-hr.; oil of 0.S5
sp.gr.
500 1b 14.5 1b
650 lb 31 lb 0.1 gal. per hp.-hr.
155C lb 258 lb
1 Olio, 000 lb 3S0 lb
1S1.000 lb 362 lb 0 40S lb. per hp.-hr.
The automobile has been responsible for the develop-
ment of the gasoline engine to a high state of perfection
during the past ten years, the motor shown representing
one of the standard makes. In accordance with the
latest practice, this is a long-stroke, high-speed type witli
cylinders cast en bloc, and weighs only 141/*. lb. per horse-
power.
Since the practical application of the aeroplane fol-
lowed closely that of the automobile, the experience with
the latter was invaluable in the design of a motor for the
former. The departures were essentially in the reduction
of weight, increase of power and provision for continued
operation at maximum load. The engine shown repre-
sents one of the most successful American designs, in
which the weight has been reduced to 31/j lb. per horse-
power and the fuel consumption to 0.1 gal. per horse-
power-hour— another vital point in aeroplane work.
The farm engine, on the other hand, had been devel-
oped with a view to ruggedness and foolproof operation,
with fair economv and little attention to weight. The
March 16, L915
POWER
377
EV0IM0^theINTERNAL-COMBU5aONtN(iINE
378
POWER
Vol. 41, No. 11
6-hp. engine shown, which is representative, weighs two
unci one-half times that of the 200-hp. aeroplane motor
and three times that of the 35-hp. automobile motor.
The 5000-hp. gas engine is one of a number of similar
units operating on blast-furnace gas and driving gen-
erators and blowers at the Gary plant of the U. S. Steel
Corporation, and represents one of the largest of its kind
now in operation in this country. Owing to the size of
the cylinders, 44x60 in., and the pressures involved, the
construction is necessarily heavy, and it is probable that
•"iOOO hp. will be about the limit for engines of this type.
Just as the Otto engine was the pioneer in the gas-
engine field, so was the Brayton in the oil-engine held.
It needed, however, the genius of Dr. Diesel and the un-
tiring efforts of the manufacturers who took up his
patents to produce what is today the most highly effi-
cient heat engine in existence. To obtain this economy
extremely high working pressures are required — 500 to
GOO lb. per square inch as compared with 50 lb. in the
Otto and slightly more in the Brayton. This necessi-
tates heavy construction, the engine shown, which is one
of American make that is being exhibited at the Panama-
Pacific Exposition, weighing 362 lb. per horsepower.
JSTSiCQl©
Siimc
By Steeling IF. Bunnell
Much has been done toward operating steam-boiler
furnaces on wastes of various plants, in utilizing slack and
culm or coal-mine wastes and in developing power from
city garbage. The question of economy is of first impor-
tance in deciding whether or not a low-grade fuel should
be used. There are three elements to be considered;
namely, the quantity of heat which can be produced
per pound of fuel, the efficiency with which this heat
can be transmitted to the boiler, and the cost of the fuel
put into the furnace. Coal at $3 per ton delivered at the
fire room and having a lieat value of 10,000 B.t.u. per
pound and fired in a furnace under conditions which give
70 per cent, boiler efficiency, must be fired at the rate of
10,000 divided by 0.70, or 14,300 B.t.u. of coal to put 10,-
000 B.t.u. under the boiler; and as 2000 times 10,000
B.t.u. cost 300c, the cost of 14,300 is 0.214c. Assuming
that it costs 30c. to fire a ton of this coal, the cost of the
coal in the furnace should be increased by ^j, or -fe, mak-
ing 0.235c. to put 10,000 B.t.u. into the boiler.
In comparison with this coal, suppose a fuel to be ob-
tainable at 50c. per ton, giving only 4000 B.t.u. heat
\alue per pound and capable of being fired with a boiler
efficiency of 50 per cent. The ( omputation shows 20,000
B.t.u. required to put 10,000 B.t.u. into the boiler; so, as
8,000,000 B.t.u. cost 50c, 20,00C will cost %c If this
Fuel costs 50c. per ton to fire, it will be necessary to add
jj$, or 100 per cent, to obtain the cost of 10,000 B.t.u.,
making the amount 0.25c. There is no money in firing
this fuel under these conditions, as the cost is slightly
more than the cost of good coal. It would, however, be
desirable to use the low-grade fuel if it were a waste ac-
cumulating like sawdust and wood refuse in wood-working
factories, in which case it would cost less to burn it than
to cart it away. If the value of the fuel were 6000 B.t.u.
per pound instead of 4000, it would figure -fee. for fuel
and the same for firing, making 0.1 66c. for 10,000 heat
units delivered to the boiler as compared to 0.235c. for
tbe coal at $3 per ton.
In every case it is important to consider all the con-
ditions in. connection with the various fuels which can be
obtained, not forgetting that good coal can be fired by
average firemen, while low-grade waste requires special
skill to handle it successfully.
The mechanical difficulties in burning low-grade fuel
are important and must be met by special construction and
firing methods. Fine coal and dust tend to fall through
the grates, no matter how small the openings are made.
These fuels also tend to pack together, making a strong
draft necessary to force air through the fire. Agricultural
wastes, like spent tan bark, often contain a weight of water
equal to or greater than the combustible. It costs as much
to evaporate water in the fuel as in the boiler.
The draft for burning most kinds of low-grade fuel
should be strong. The worst and wettest garbage is suc-
cessfully burned in furnaces supplied with forced ashpit
draft under pressures of 2 in. and more of water. If
means can be provided to heat the air before entering the
ashpit, by using waste heat from the flue gases, the com-
bustion in the furnace is imptroved. The moisture con-
tent of the fuel should be reduced as much as possible.
Sometimes this advantage can be gained by a change in
the mechanical operation producing the waste. If not,
it is usually necessary to fire the fuel as it comes, regard-
less of the quantity of water it may contain, as fuel-dry-
ing operations on a large scale are practically impossible.
One instance to the contrary, however, is the burning of
sewage sludge, wliich is first dried by passing it through
a rotary drier in which hot flue gases circulate. Sewage
sludge, however, has no heat value, and is burned merely
to dispose of it without nuisance.
With most materials containing much moisture the
drying must take place in the furnace and this requires
careful watching and stoking. Sometimes a drying hearth
can be provided on which the wet fuel can be first charged
and allowed to dry in the direct heat of the fire. It is im-
portant to observe that the fuel must not be burned faster
than it can be dried, or the fire will soon be blocked
and extinguished by wet material. The fireman must,
therefore, manage to keep a brightly burning fire of dried
fuel and to supply wet fuel so that most of the moisture
will dry off before the fresh material is charged on to the
burning surface.
A common difficulty with low-grade fuel, particularly
coal waste and tlie rubbish from cities, is the presence of
mineral matter which forms clinker. With good coal the
proportion of noncombustible substance amounts to only
a small percentage, not enough to form very bad clinker.
Factory ashes from well handled fires contain only a small
fraction of unburned carbon and are finely divided into
small particles. From the average house furnace, however,
tbe ash contains one-half or more of combustible carbon.
Su.li ash. tired in a suitable furnace with forced draft,
would be of commercial value. As tbe combustible por-
tions of low-grade fuel burn away, the areas of worthless
ash and clinker remaining become larger. The melting
clinker tends to inclose particles of unburned coal and
prevent air from reaching it. With all low-grade fuels,
therefore, the fire must be carefully watched, and the free
passage of air through it must be maintained by stoking,
and breaking up areas where combustion is giving out
from lack of accessible fuel.
.March 10, 1915
SaillllllllillllllllNIIIIIMlIlllUOMUIIIllllIlllllllllllllinilllllllllllillllllillllllllllli
POWE B 379
unuuiiiiui iiiniiiiiii i iiiiiiiiiiiiiiiiiiiiiiiuiiiiiiiiiiiiiiiiiiiiiiiiiumiii'iiiiiaiiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiiiiiiiuiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiij
[iiiiiiiiiiiiimmraiiiniiiuiui
imiiiiiiiisa ii iiiiiiiiik -
Fllywlh©©! I£sspIl©sI©Eas
In the power plant the boiler is commonly regarded as
the most dangerous part of the entire equipment. Prob-
ably nine out of every ten engineers are of this opinion,
and it is not surprising, as the number of boiler ex-
plosions in this country is excessive, the casualty list is
large and the value of property destroyed is greater by
far than in other lands, where rules for safety are more
rigidly and uniformly enforced. From people who should
know, however — men dealing every day in power-plant ac-
cidents— comes the surprising information that the fly-
wheel is more dangerous than the boiler. In other words,
the ratio of flywheel explosions to the number of flywheels
installed is greater by one-third than that for boilers.
This doc- not refer to totals, as boiler explosions would
then have the lead by a large margin, owing to the greater
number of boilers installed.
Viewing power-plant safety from this standpoint, it is
evident that more attention is due the flywheel. Every
boiler has its safety valve, and if statistics are of any
value every Awheel should have at least equivalent pro-
tection.
The potential energy stored in the flywheel is tremen-
dous, although, owing to the swift and even turning, ap-
pearances are to the contrary. There is no indication of
danger, and as a result, proper precautions are not often
taken. The rim velocity of an average flywheel is close
to a mile a minute and it is seldom that a wheel ex-
plodes at a velocity lower than three miles per minute, or
264 ft. per second. The damage that might ensue from
the heavy pieces of disrupted wheel moving at this terrific
velocity may, perhaps, be imagined. Numerous articles
in the past have recounted the actual results.
Property damage, however, is only a minor considera-
tion when compared to the safety of employees. For
every flywheel explosion the average is one man killed or
injured, and the toll for the year is so heavy as to warrant
every precaution which will tend to prevent these acci-
dents.
The function of the governor is to control the speed of
the engine and with it the flywheel. Usually, there is also
included a safety provision to guard against emergencies,
but this is a secondary consideration in the design, and
there are certain contingencies which it will not take care
of. With this single protection against accident, de-
rangement of the valve gear or failure in the governor's
own mechanism may result in disaster. An independent
device is needed to make safety doubly sure, and this de-
vice is the safety stop.
When the engine reaches a predetermined speed, the
stop automatically shuts off the steam and relieves the
engineer of the dangerous task of trying to close the
throttle under emergency conditions. If the governor fails
to work, the stop is on guard to prevent destruction. In
military circles the secret of success lies in a strong reserve
to supplement and reinforce the first line. In the engine
room the stop occupies the same position. It is ready to
come to the rescue of the governor, and if kept in good
working condition it will reduce the number of accidents
and afford added protection to the engineer.
Neglecting the damage to properly and the interrup-
tion of service usually resulting from a flywheel explo-
sion, the device is warranted from the standpoint of safety.
At best, power-plant work is dangerous and there are few
places in which the "safety-first" slogan is more urgent.
The life of at least one engineer every week is surely
worth saving, and if the installation of safety stops will
effect even a small reduction in the fatalities, there is not
a power plant in the country which should not have one.
It is due the engineer, and incidentally, the reduction
of property loss may be worth while to the owner.
Cosiapiislsor^ IBoileir HKispectta©^
In most of these United States a man may buy any old
kind of a boiler that he wants to, new or second-hand,
have it set up by the local plumber, hire the hunk to run
it who will do it for the least money, and put any amount
of pressure upon it that he sees fit.
It may be said that ordinary business prudence and fear
of damage to himself and his own people and property
would preclude a man from taking too long chances; but
any government or insurance inspector can tell of numbers
of death traps set by the cupidity or. in justice be it
.-aid, more often by the ignorance of the boiler user.
Last year the inspectors of the Hartford Steam Boiler
Inspection & Insurance Co. condemned outright 756
boilers as unsafe to use, and pointed out 23,012 defects in-
volving the safety of the boiler.
In the same time the inspectors of the Fidelity &
Casualty Co., of New York, condemned outright 340
boilers and pointed out 11,130 serious defects.
This, after the boilers had been prepared for inspection
by the agents of their owners. These are only two, but
the largest two, of a number of companies carrying boiler
insurance. There are nine such companies doing business
in Massachusetts.
Is it not reasonable to suppose that, if these boilers
had not been inspected by specialists, there would have
been a considerable addition to the loss of life and prop-
erty by boiler explosions ?
It is true that boilers which have been insured and in-
spected have exploded. Inspectors are human and fallible.
They may overlook obvious faults, and there are hidden
cracks in lap seams and flanges which the best of them
could not detect; but this is no reason for condemning
the whole system and renouncing the good which they are
doing.
If the inspection incidental to insurance has revealed
this number of serious defects, why would not an equally
thorough and efficient inspection of uninsured boilers
reveal an equally large proportion of defects and ob-
\ iate an equally large proportion of explosions ?
Are the boilers whose owners take a chance apt to be
3S0
POWER
Vol. 41, No. 11
better selected, installed and operated than those whose
owners take the precaution to insure them ?
In Massachusetts 17,9(59 boilers are inspected by the
insurance companies. The state inspects the rest of them,
6723, itself. This is what all the states ought to do.
Public safety ought not to be left to the "ordinary
business prudence" of any man in the matter of boilers
more than in storing and using gasoline or explosives.
A boiler full of hot water under pressure is just as
dangerous under a sidewalk or a building as a keg of
gunpowder.
The necessity of governmental regulation seems too
obvious to question. Everybody docs it but us.
Saffefts^Vaflve Capacity
One of the hardest nuts which the American Society of
Mechanical Engineers' committee, while preparing the
standard boiler code, had to crack was the question of
safety-valve capacity. Previous to the last annual meet-
ing the manufacturers of safety valves got together
and said : "Now, let us go at this thing scientifically.
What has a safety valve to discharge?"
•"Steam."
""How much steam?"
"As much as the boiler can make — and then some."
"How much can the boiler make?"
"Ah ! that depends upon the boder, and the furnace,
and the fuel, and the air supply, etc. But if we take the
heat value per pound of the fuel and multiply that by the
number of pounds which can be burned under the boiler
per hour, multiply that again by the combined efficiency
of the boiler, furnace and grate, and divide the product
by the difference between the total heat per pound of
steam as made and the heat per pound in the feed water,
we shall find the amount of steam made per hour. Then
we can give them a table of the discharge capacities of our
valves of different sizes, and they can tell right away how
many valves, of what size, it will take to discharge this
amount of steam."
But the discharge capacity of a valve depends upon its
lift, and there are makers who believe in high lifts and
those who do not. After long discussion the valve manu-
facturers agreed unanimously upon the table of capacities
which appeared in the third and fourth reprintings of the
tentative report of the committee.
The proposed method evoked storms of protest. The
conception of the country pipe fitter struggling with the
B.t.u. per pound of fuel, the heat of the liquid and of
evaporation, and the possible effect of draft on rate of
combustion, was a little too much. The government and
insurance inspectors vowed that it would take longer to
inspect the safety valve than it would the boiler.
The question was therefore turned back at the safety-
valve men, and they, unable again to meet upon a com-
mon ground as to a standard rate of discharge for
safety valves, have presented a table giving the dis-
charge in pounds per hour at minimum, intermediate
and maximum lifts. The three-inch valve of no manu-
facturer shall lift less than five-hundredths nor more
than one-tenth of an inch at one hundred pounds gage,
and it is guaranteed to discharge certain amounts per
hour at each of these lifts and the average of them.
At its rated capacity a boiler is expected to evaporate
about three pounds of water per square foot of heating
surface. In some of the large stations they are evaporat-
ing ten or more. If it be assumed that any boiler may
possibly be subjected to this rate of evaporation some
time in its life, and the amount of steam to be provided
for by the safety valve be assumed at ten times the number
of square feet of heating surface, the calculation would
become an extremely simple one. A boiler having one
hundred square feet of heating surface might possibly
be subjected to conditions under which it would evaporate
ten thousand pounds of steam per hour, and to discharge
this would, by the table submitted, require one four-and-
one-half-inch or two three-inch valves, at one hundred
and fifty pounds gage pressure.
This gives somewhat more valve area than is common
in ordinary practice, and ordinary practice seems to be
good enough, for we never knew of a boiler which ex-
ploded for want of safetv-valve capacity when the safety
valve was operative at all. The modern high rate of com-
bustion is provoked and intentional, and can be attained
only purposely by well managed fires urged by artificial
draft. A boiler even in the heart of a conflagration would
not accidentally do as much. A smaller though somewhat
less convenient factor than ten would doubtless have to be
used, but it would seem that the heating surface is the
logical measure of the safety-valve capacity. The grate
area may be changed from time to time, oil or gas may
be used, the boiler may simmer under a natural draft
or fume under the action of a blower, the fuel may
vary from wet tanbarl to oil or natural gas, but the num-
ber of square feet oi heating surface is always the same.
and if the boiler is provided with safety-valve area to take
care of all the steam which that heating surface can gen-
erate, it will make no difference who gets the boiler or
what he does with it, as far as this phase of the question is
concerned.
Committee work in engineering organizations is usu-
ally hard, tedious and trying, but the fellow who never
did any is the one who most loudly proclaims that ifs a.
sinecure.
a
Beats all how some engineers can go through most of
their lives telling themselves they do not need to keep
studying the progress of their calling, and then suddenly
become most enthusiastic over engineering educational
work. In nine cases out of ten you will find that the
change of front is due to the central station making a
strong bid for their jobs.
8
Several inquiries have come to us regarding the decision
of the American Manufacturing Company, of Greenpoint,
L. I., to discontinue running its power plant and to pur-
chase power from the Brooklyn Edison C mpany It would
seem that the amount of power here used could be gen-
erated on the spot more cheaply than a public service
company could furnish it, and we sought, an interview
with the officials of the company for the purpose of learn-
ing, if possible, the facts which led to the decision. The
only statement which was forthcoming was that it had
been made to the advantage of the American Manufac-
turing Company to purchase its current from the Brooklyn
Edison Company and that there was nothing to discuss
regarding comparative costs. The mere cost of production
is not always the controlling factor in the interrelations of
Bin- Business.
March L6, L915 POWER 381
duiiiiiiiiiiiiiiiiiiiinii ['ilium ittiimi iiiuiiiiiiniiii iii.i)iinii mum mini miiiimiii mi im i 111 numiiiiiiiimiiiiiiiiinnnmiiunniiiiiini miinin iiiiium iimiiiiiiiiiiiumj
espomi©
in inn mini m i mini i mini minim mmin mninnnniininnmu nm tin iiinni' nun i uiniiiii ill mil in mil mini i nniiimnnnnnnnuiF
When transformers are connected in parallel or series
it is first necessary to determine which are like poles.
After the transformers have been set symmetrically, con-
sider all right-hand terminals of one polarity, say positive,
.-Hid all left-hand terminals of the opposite polarity; then
proceed as though connecting batteries, as indicated in
Pig. •!. which shows two transformers connected in paral-
lel. By comparison with Fig. 1 it will be seen that the
grouping is similar. There is always a chance of the
leads being brought out of the transformers to give the
wrong polarity, and to guard against a short-circuit, con-
nect a piece of two- or three-ampere fuse-wire in the low-
voltage side as shown at /'. Fig. :>. Then close the primary
circuit with the secondary disconnected from the load,
and if the connections are correct the fuse will not blow.
After reading .Mr. Fox's article on transformer connec-
tions in the issue of dan. 12, I feel that although In-
process of testing the polarity of transformers and group-
ing them to obtain various results is instructive, it could
I..- somewhat improved by adding a simplified method for
remembering the various connections and ways for deter-
mining when the devices are connected properly.
The opinion seems to exist among practical electricians
with a limited knowledge of electrical theory, that there
is one particular kind of parallel and series connections
/or batteries and some other kind for transformers or other
devices: hut this is not true, as there is one hard and fast
rule that applies to all. When batteries are con-
laMMJO.
ffiOTM
*--E----4
2E
i< E >
F
F1C-.IO.
Connections of Transformers
uei ted in parallel all positive terminals are connected
together, likewise all negative terminals, and then a posi-
tive and a negative lead are brought out from the group
as indicated in Fig. 1. What is true for this is also true
for any other electrical device, from which the rub1 for
parallel connection may be obtained, namely, connect
like poles to like poles and bring out two unlike leads.
In connecting batteries in series a positive terminal
is connected to a negative terminal until all are con-
nected except one negative and one positive; these two
are connected to the device to be operated. This is in-
dicated in Fig. 2 and is true for any device, from which
the law for series connections is obtained, namely, con-
nect unlike poles until but two remain unconnected:
brine these two out to the load.
FIG.8 FIG.9.
If the fuse blows, cross cither the primary or the secondary
leads of one transformer as in Fig. -I ; this will correct
the defect, irrespective of which transformer had the
wrong polarity. A test lamp or voltmeter may be used in
place of the fuse. If the connections are correct the lamp
should not light nor the voltmeter read. The fuse, how-
ever, is not only the most likely to be at hand, but is also
the most reliable, as there is always a chance of a defective
lamp or instrument.
When transformers are connected in series the same rule
i- followed as in batteries, and by comparing Fig. 5 with
Fig. 2 it will be seen that the same relation of connections
is maintained in both cases. However, if the leads are
brought out of one transformer to give the wrong polarity,
the proper voltage relation will not he obtained on the sec
ondary side, which should be as indicated, and instead of
the voltage being 2E between the two outside terminals,
it will be zero. This can be remedied by crossing the sec-
ondary or primary leads on one of the transformers.
There are usually four leads brought out on the low-
voltage side of all small commercial transformers; the
two center leads being brought out crossed as in Fig. 6.
This brings the like terminals of each coil adjacent to
each other and eliminates crossing them on the outside
when the coils are connected in parallel as shown in Fig.
382
POWE R
Yol. 41, No. 1 1
*. Care should he taken not to conned the two terminals
of each coil together as in Fig. S. for this would be a dead
short-circuit.
It may he easy lor those familiar with the laws of
graphics and alternating currents to depend upon connect-
ing transformers so that thej form an angle of 60 or 120
electrical degrees to each other to obtain a delta or star-
connection on a three-phase circuit : hut for the man that
does not possess this knowledge, the fact that the delta
connection, as far as the grouping i- concerned, i- noth-
ing more than a short-circuited series connection should
greatly simplify the matter, as will he understood by refer-
ring to Fig. 9. The three transformers are connected
in series as are the batteries in Fig. "?. hut instead of
Lng out the two outside terminals to the load as in the
battery connections, they are connected together to form
a complete loop with a lead brought out from each junc-
tion point. To make sure that the connection- have been
made properly and the transformers are all the same po-
larity connect a piece of fuse wire as at /; if the fuse does
not blow the connection- are correct and the transformers
are of the proper polarity.
The making of a star connection may be greatly simpli-
fied if it is remembered that like terminals of the trans-
formers are connected together (it may he either the right-
hand or the left-hand terminal) and the other three ter-
minals are brought out to the line as in Fig. 10. which
shows the three right-hand terminals connected, with the
three left-hand ones brought out to the line.
A. A. Fredericks.
New York City.
v
Eowm
A disastrous boiler explosion occurred at the electric-
light plant at Menlo, Iowa, shortly after 6 p.m., Feb.
14, killing three men instantly and completely demolish-
ing the power house.
The boiler was of the return-tubular type, of 60-hp.
Fig. 1. Wreckage after Boiler Explosion
capacity. The safety valve was set at 95 lb. The rupture
occurred in the rear sheet, which ripped entirely around
where it joined the middle sheet, and was thrown a
distance of about 300 ft., breaking a number of telegraph
lines in its descent. The rear flue sheet was thrown a
distance of 600 ft., and fell through the roof of a dwell-
ing shown in Fig. 2 and landed in the kitchen. A heavy
stop valve fell in the yard of the <ame residence. As the ex-
plosion occurred at the supper hour, the occupants of
the house were seated at the table in an adjoining room
and no one was injured.
The power house -too,! some distance from other build-
ings and being constructed of heavy concrete, the injury
to the surrounding property was slight, consisting of some
damage to roofs due to falling pipes, brick, etc. The
heavy concrete walls, together with the fact that the
boiler was set below the ground line, undoubtedly prevent-
ed much damage to the adjoining property.
\o definite cause is known for the explosion, as all
those who might know were killed. The 1. oiler was about
L8 cars old and fairly clean and free from scale. The
men were evidently sitting directly in front of the boiler,
judging from the position in which the bodies were found.
Fig. 2. The Tube Sheet. Fig. 3. The Bear Circular
Sheet Xear Railway Track. Fig. 4. Clo-e
View of Pitted Sheet
Had the accident occurred a few minutes later it is likely
the loss of life would have been much greater, as it was
the custom of a number of the employees and others to
spend some time at the plant after the supper hour.
S. Kiklik.
Stuart, Iowa.
I Figs. ?. 3 and 4 were received later from J. C. Bruff,
Atlantic, Iowa, without additional information as to the
probable cause of the explosion. — F.ditoi;.]
March 16, 1915
1' 0 \\
)nlM©2'©iaft
ES. sites
There appears to be a prevalent idea that central sta-
tions sell power below cost to large consumers and make
up the loss by charging the small ones bigh rates. It
doesn't seem to occur to some of these | pie, however,
that if this were true it would be a wise policy to cut out
the large consumer and make a still larger profit.
The average power company has a scale of many dif-
ferent rates to cover different conditions, and the writer
will attempt to explain the reason for some of them. To
make the explanation more simple, he will compare the
prodm-t an. I sale of electricity to ire. Let the square
Bgure represent a pond with a crop of ice. Jones, the ice-
man, builds up a trade from house to
house to sell in lots of 50 to 100 lb.
daily from his wagon and will cut the
area marked A. lie also looks over
the grocery and provision markets
that, will take 200 to 500 lb. daily
and estimates that the area marked II
will supply them. There is likewise a
large demand from the ice-cream fac-
tories and soda fountains, each of
which will require 1000 to 2000 lb.
per day, and he secures that business, requiring him to
cut area marked C.
In the town where Jones does business Smith and
Brown have small icehouses which are badly in need of
repair, and it occurs to them that Jones can harvest the
balance, or area marked D, cheaper than they could har-
vest their own, so they arrange to take that amount
from Jones. To harvest ice marked A.
Cost of labor per ton $100
Cost ot machinery, house and other equipment per ton 1 ;50
c
D
B
A
Diagram
Representing
Pond
Total cost per ton
To harvest B, in addition, wil
require another
story
d the labor will be more efficient,
on the icehouse
making
Cost of labor per ton *o 85
Cost of machinery, house and other equipment per ton 0.85
Total cost per ton $1.70
To harvest C, in addition, will require another story
on the icehouse and the labor will continue to become still
more efficient, making
Cost of labor per ton SO. 75
Cost of machinery, house and other equipment per ton 'niai
Total cost per ton $1.35
To harvest D will require another story on the ice-
house, still using the same machinery as at first, and
there will lie a slight improvement in labor, making
Cost of labor per ton $0.70
Cost of machinery, house and other equipment per tun " I :,
Total cost per ton $1.15
Leave out the shrinkage and otheT Losses before sum-
mer and consider the delivery.
A two-horse team is worth $5 per day and two men will
cost about $5 more, making $10. These will make two
trip- pei' day, delivering one ton per trip to householders
taking 50 to 100 lb. of ice. The usual rate to consumers
of small quantities is about $8 ]>er ton. so it is easy to Bg-
ure the profits:
Two tons at $S per ton Jit; (in
Cost of two tons at $1.15 $2.30
Cost of team 5.00
Cost of two men 5.00
1 2 SO
Gross profit $3. Til
38:5
The rate to markets which lake 200 to 500 lb. may lie
$6 I""' ton, and a similar team would make three trips per
day, or deliver three ions, the profit working out as fol
lows :
Three tons at $6 per ton six Oft
<'ost of three tons al si i;. «Vis '
Cosl .no -- , ';
' It Of tH o ,, ;; ....
— — 13.45
Gross profit ~$4~55
The rate to ice-cream factories ami soda fountain:-,
which take 1000 io 2000 lb. at a time, and allowing the
team to make five trips daily, may be $l per ton, working
out as follows:
Five tons at $1 per ton .« on
Cost of five tons at $1.15. $575 * °
Cost of team - ,HI
Cost of two men ... ..[[.. .. 500
15.75
Gross profit $4.25
Now Smith and Brown have arranged to take their own
ice from the house, using about ten tons each per day,
and Jones made them the ridiculous price of $2 per ton:
but the profit comes out as follows:
10 tons of ice at $2 t
Cost of 1:: tins -t $1 I- "i, ' ";:
Gross profit $8.50
,r is c\ ideut that Jones cut down bis cost by harvesting
the whole field, ami if he bad stopped at A he would have
had to charge at least $10 per ton to householders, to make
a reasonable profit.
On the other hand, he could not charge the markets, ice-
cream factories and Smith and Brown (whose business
caused the whole lot to he cheaper) the same price as
the householder for two good reasons — he couldn't gel
the business, and if he did the profits would be unreason-
able.
If Jones found it necessary to give up part of his busi-
ness and had his choice, which part would hi' drop?
Charles U. Seed.
Worcester, Mass.
©IIl<=I£-img|air&© T@iradl©inicnes
In the Feb. !) issue, under the heading "Oil Engine Ten-
dencies,"' Mr. Ward makes a number of statements to
which I wish to take vigorous exception, based on many
years of work on this subject.
OiL-FiF.i. Situation
.Mr. Ward states that, since petroleum is composed of
15 per cent, gasoline, 15 per cent, kerosene, 10 per cent,
high-grade distillate above 39 Ar^. Baume, 10 per cent.
low-grade distillate below ::'.! deg. Baum6, 15 per cent, lu-
bricating oils and a remainder of 5 per cent, '•slop." not
over 10 per cent, is of such a nature as to require a crude-
oil engine to utilize it. In Mexico, for instance, there is
much oil which is of an asphaltic base and so low in vola-
tile or refinable products as to be practically valueless lor
refining. The oil to which Mr. Ward referred was evident-
ly of a paraffin base, which constitutes less than half the
oil supply. 1 1 I am correct, over 60 per cent, of the raw
product a- drawn from the wells is available only for use
in the heavy-oil engine, fur generating steam, etc
Skm [-Diesel Ti pe
It is further Btated in the article that by chan
from 5oo to 300 lb. compression, the fuel does not burn
:;si
IM> W E R
Vol. 41, No. 11
immediatel) upon entering the combustion space, a- the
hear of compression is insufficienl to ignite it. 1 haw
demonstrated thai for a running engine 150 lb. is suffi-
cient t<> ignite the fuel.- the hot plat.' being needed only
[or starting in the engine which 1 haw developed. Mr.
Ward says that the semi-Diesel typo should lie built as
Ikmm as the regular Diesel; further, that the maximum
pressure in the semi-Diesel is 500 lb. The Diesel must
have a relief valve set at from 750 to 800 lb., indicating
that the pressure frequently runs to 800 lb., whereas
the semi-Diesel pressures do not run over 500 lb. Ac-
cording to tin- the semi-Diesel need be built only five-
eighths a- strong as the Diesel. The writer's experi-
ments would tend to indicate that an oil engine can be
built which nee.l he but little heavier or stronger than the
conventional gas engine.
Two-Stroke-Cycle Type, Fuel Injection and Hot
Bulb
Of these points I have little to say. except to voice the
opinion that the two-stroke-cycle type can be beaten on
every point by the four-stroke-cycle type. The fuel in-
jection i- -til! MTV crude and is only slightly developed
Iron: what Brayton disclosed in 1890. It seem- possible
K. greatly improve upon the present arrangements, but
my experiments along this line as yet are incomplete. Hot
bulbs seem to he uncalled for and are not very practical
lor la rue sizes.
Water Injection
This is the weakest point in the semi-Diesel type. Mr.
Ward says that a pressure of 300 lb. is not sufficient to
ignite the fuel, and yet he mentions the use of water
injection in order to keep the temperature of compression
within bounds. The use of water from a thermodynamic
point is as wise as it would he to propose to govern an en-
gine by an automatic brake that would absorb the un-
needed power and in this way regulate the speed of the
engine. Provided the engine can first be started, the
Brayton fuel injection can be used on the semi-Diesel
type and the waste from the water injection can thus
In' avoided.
Lubrication
The writer tails to see any problem in the lubrication
of the oil engine not met in the gas engine. The jacket
should lie used to keep the temperature at a point which
i- reasonably below the safe line. To go below this point
is wasteful; to go above it is dangerous.
The writer got into a controversy with an engineer
in the employ of the original Diesel Engine Co. of
America in 1904. The point was the maximum tempera-
ture in the engine, which at that time was taken to be
the temperature of compression. Temperature calcula-
tions were made from a Diesel diagram and submitted to
the company. The answer was that the engine worked
and that was all that the firm was interested in. The
writer was interested, however, and as a result of this
lack of interest on the part of the oil-engine men con-
cerning their engine, has been able to be the first appli-
cant in the TJ. S. Patent Office on many lines of develop-
ment of the oil engine. There is a thermodynamics of the
steam engine. In the gas engine one is limited by prema-
ture explosion, in the amount ,,f compression carried. In
*See paper by the writer presented before the last meeting
of the Society of Naval Architects: also abstract of same in
"Power,' Jan. iC, 191',.
the Diesel, owing to starting troubles, one is limited in the
minimum compression on account of lack of ignition. The
ml engine, once it is started or warmed up, can be operated
on any pressure from, say 125 lb. up. The best method
for getting the oil engine into a condition to avail itself
of this low pressure of compression depends upon the use
of the engine. For large engines there can be no better
method in tl pinion of the writer than to follow the
practice of the steam engineers, namely, that of warming
up their engines by the introduction of steam into the
jai kets.
John F. Wextworth.
Quincy, Mass.
wavairas
><DHleirs caE&'
Tribes
Referring to the discussion of the above subject which
was started by the picture and story of a burst boiler
tube given in' the Dec. 8, 1914, issue, page 805, the
editorial comment on page 95, Jan. 19, 1915, is correct
in stating that increasing the furnace heat increases the
evaporation. However, Mr. Kent is right in saying
that there may be times when the beat will be greater.
as when the -team gets low and it becomes necessary to
regain the pressure: the heat must he increased and also
the evaporation, but the average evaporation remains
the same.
The temperature of the water in the tube has nothing
to do with overheating the tube, for the water, either
hot or cold, will take up all of the heat that can be
forced through the insulation of oil or scale in the tube.
The pressure has a great deal to do with the bursting
of the tube, as it will require more overheating to burst
the tube at low pressure than it will at high pressure.
Willis W. Nelson.
Spokane, Wash.
tj)ili Sjepsvif^
Referring to the query by 11. G. Goodwin in the issue
of Feb. 9, page 207, I would suggest that for a possible
source of trouble he should examine his sewer connections.
Referring to his sketch, we lind that, as nearly as can be
estimated, there is a difference of ten to twelve feet head
in the two connections leading to the sewer. If the sewer
connection is not adequate and is connected to other
sources, it is possible that water backs up in the pipe lead-
ing to tlie oil separator in the basement until conditions
allow the oil and evliau-t steam to pass over into the heat-
ing system. This oil would naturally be carried into the
heating system through the lower oil separator on account
of the difference in head between the pipes leading from
the two oil separators.
If such a condition existed the remedy would be to
disconnect the exhaust from the 25-hp. engine in the
basement and connect it with the same piping which leads
from the 100-hp. engine on the first floor. This would
remedy the trouble it' the oil were passing into the heat-
ing system from the basement floor only. If oil then
1 over and if the rain-leader connections from the
building led into the same sewer, the remedy would be to
run independent sewer connections from the oil separators
and from the heatinu system.
W. R. Metz.
Washington, D. C.
March 16, 1915 POWER 385
piiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiuiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiinii iiiiimi iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiuiiiiiiiiniiiiniiiiiiiiiiiiiiiiiiiiiiiiiiuniiiiiiiiiiiiiiiiiiiiii iiniiiiiiiiiiiiuiiiiiiiiiiiiiiiiiiiiiiitiiiiiiiniiiiR
Eirnqf^airies ©f Geimeiml I nutter esft
iiiiNNiiiiiiiiiiiiniiiiiiiiiiNii iiiiiiiiiiiiiiiiiiini mi iiiiiiiiiiiiiiniiiniiiiu iiiiiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiii iiiniiiiiiiiiiiininiiuiiiiiiiiiiiniiii iiiiiiiiuiiiiiiiiiiiiiiuiiiunniinniiiiiiuiniiiiiiitniiiiiiiiiniiiniiiiiiiiniiiiiiiiiiiiiiimiiiiiiiii mm™ iiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiinii
Chatter of Reducing Vah
valve to chatter?
-What will cause a reducing
E. H
A reducing valve is likely to chatter if the valve is large
in proportion to the use of steam at the reduced pressure. In
most cases the remedy for chattering is to throttle the supply
or to throttle the valve which admits low-pressure steam to
the diaphragm.
Advantages of Mechanical Stokers ESurning Cheap Fuel —
Why are mechanical stokers better adapted for burning the
cheaper grades of fuel than hand firing?
<;. M.
A mechanical stoker can usually handle a lower grade
of fuel because it carries a cleaner fire, the coal is fed more
uniformly and the air required for combustion can be sup-
plied at a more uniform rate.
Percentage of Output for Kxeitation — What percentage
of output of an alternating-current generator is required
for excitation?
L. H.
The excitation of a generator will vary according to the
load and the voltage, but, under normal conditions and rated
load, will amount to from 1 to 2 per cent, of the generator
output in large machines and slightly more in smaller
machines.
Weight of fast Iron, Wrought Iron and Steel — What is
the weight per cubic inch of cast iron, wrought iron and
steel?
G. L.
The weight of each varies with the texture and method
of manufacture. The approximate mean values used in cal-
culations are 0.2604 lb. for the weight per cubic inch of
cast iron; 0.2779 lb. for wrought iron, and 0.2S34 lb. for steel.
but more commonly 0.26 lb. for cast iron and 0.2s lb. for both
wrought iron and steel.
Heating of Conduits Containing Wires of Polyphase Cir-
cuit— When the wires of a polyphase circuit are put in sep-
arate conduits, instead of all in one conduit as is usually
done, why is it that the conduits heat?
E. D.
The greater the distance between conductors of a poly-
phase circuit, the greater the induction set up between these
conductors, hence, the greater the heating effect thus pro-
duced. Putting the conductors in the same conduit lessens
the distance between them, thereby cutting down the in-
duction and the heating effect.
Required R.p.m. to Develop loop Hp. — How many revolu-
tions per minute would be required for development of 1000
hp. by a pair of hoisting engines having cylinders 30x60 in.
ami ;t mean effective pressure of 90 lb. per sq.in.?
W. C. R.
As 1000 hp. would represent a development of
33,000 X 1000 = 33,000,000 ft. -lb.
of work per minute and as one revolution of the engine
would develop
90 X HO X 30 X 0.7SS4) X "%. X 4 = 1,272,348 ft. -lb.
then for the development of 1000 hp. the engine would have
to make
33.000,00(1 -f- 1,272,348 = 25.93 r.p.m.
Working- Pressure for Old Railer — Is resistance of a
hydrostatic test pressure HO per cent, in excess of the
working pressure proposed for an old boiler sufficient for
determining the safety of the boiler operated at the pro-
posed working pressure?
A. B.
A hydrostatic test pressure would only determine whether
the boiler would probably be tight for the proposed working
pressure. The working pressure should be decided from
computation of the safe working strength of parts, based
upon internal and external inspection before and after the
hydrostatic test, with due consideration of the condition of
the material and previous kind and length of service of the
boiler.
Higher Efficiency with oil than with Coal Burning —
Why are higher boiler efficiencies obtainable with oil burn-
ing than with coal burning?
W. E. C.
Oil burning can be conducted with admission of but little
more air than that which is required for furnishing tin-
oxygen actually necessary, the furnace doors need not be
opened while the boiler is under steam, and the boiler sur-
faces are not so quickly fouled with soot. In coal burning,
to obtain distribution of an adequate amount of oxygen for
the perfect combustion of each atom of carbon in the coal,
it is necessary to introduce sufficient air to contain aboul
double the quantity of oxygen actually required by the
combustion. Therefore, in oil burning there is less loss from
excessive air supply and, consequently, higher efficiency.
Difference of Mater Pressure from Difference of Tem-
perature— What would be the difference in pressure per
square inch of a column of water 4 ft. high at a temperature
of 40 deg. F. and at 100 deg. P.?
i; W. L.
The weight of a cubic foot of water at 40 deg. F. is 62.42
and the pressure per square inch exerted by a column 4 ft.
high would be
62.42
X 4 = 1.733 lb. per sq.in.
144
and as the weight of a
the pressure exerted by
ature would be
ibic foot at 100 deg. F. is 62.02 lb.
4-ft. column at the latter temper-
.112
X 4 = 1.722 lb. pe
and the difference of pressure would be
1.733 — 1.722 = 0.011 lb. per
Discharge of Steam to Vat — What will be the rate "I
discharge of steam at 100-lb. gage pressure from the open
end of a 1-in. pipe into water contained in an open vat
with the end of the pipe submerged about one foot'?
W. E. P.
The rate of discharge can be approximately determined
by the Napier formula for discharge of steam through an
orifice into a pressure which is less than .'iS per cent, of the
initial absolute pressure, viz.:
A X P
\Y
70
in which
W = Weight of steam discharged, pounds per second;
A = Area of orifice in square inches;
P = Absolute initial pressure,
according to which the discharge would be about
0.7S54 X (100 + 15)
— 1.29 lb. of steam per second.
70
Clattering Kxhaust Valves — How can I stop the clatter-
ing noise of the exhaust valves of a noncondensing Corliss
engine, which usuallj occurs when the engine is running
light?
B. N.
The noise is probably due to the valves becoming un-
seated from expanding the steam below atmosphere, in
which case the remedy would be to run the engine with
lower initial pressure, obtained by carrying- lower boiler
pressure or by throttling, and thus secure higher terminal
pressure. If it is not practicable to reduce the initial pres-
sure, expansion below atmosphere can be prevented at small
cost of economy by joining together the indicator connec-
tions of opposite ends of the cylinder and, ' having them
throttled sufficiently to prevent bypassing of more steam
than found barely necessary to prevent the clattering of
the exhaust valves, by admission of only enough pressure
from one end of the cylinder to the other to prevent expan-
sion below atmosphere.
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
l'o w e i:
Vol. n, No. 1 1
CoinffiffiinS@sn©im ©2=dl©E=s M©dluBc^n©!nv
ana. 3Edlns©!a States
Following so closely upon Governor Whitman's investiga-
tion of the New York Public Service Commission as to im-
ply a belated attempt to make good, the commission, after
nearly four years of investigation and protracted hearings,
has announced a decision in the Stadtlander case. By this
the New York Edison Co. is ordered to reduce its maximum
price of electricity from 10 to Sc. per kilowatt-hour. This re-
duction, if put in effect, will mean a saving of perhaps two
million dollars annually to the large number of small con-
sumers.
Commissioner Maltbie, who conducted the hearings, offered
a resolution to reduce the price from 10 to 6*Ac. per kilo-
watt-hour, allowing the company to charge for the meters.
This was voted down, 4 to 1, and Commissioner Williams'
resolution for a reduction from 10 to Sc. was substituted. The
former would have meant a greater saving to the large re-
tail consumer, such as the storekeeper, but would hardly have
favored the average householder as much as the recommenda-
tion adopted.
Just what action the Edison company will take in com-
plying with the order is not known.
V
ILairg!© Goffimpo^airadl Coiadleinisnmig
HI©nstt
The largest compound condensing hoisting engine in the
world was recently ordered by the Homestake Mining Co..
and built by the Nordberg Manufacturing Co. It is of the
duplex inclined cross-compound type, as shown by the side
view. The two high-pressure cylinders are 2S in. in diameter
and the two low-pressure 52 in., all with a common stroke
of 42 in.
The hoist is built with two reels, each on a separate
crankshaft. The reels are driven by axial plate clutches
Nordbkrg Compound Condensing Hoisting Engine
and equipped with gravity post brakes, air-operated. The
hoist lifts 1 2, (inn lb. net of ore per trip from a depth of 3200
ft. in a vertical shaft. The rope is %x7% in., and the total
rope pull is 41,900 lb.
The initial steam pressure is ISO lb. gage. All cylinders
are steam-jacket >d. and the exhaust pressure is maintained
at 26-in. vacuum by a special design of counter-current jet
condenser developed by Mr. Nordberg for hoisting-engine
work. The circulating and dry-air pumps are direct-connected
and driven by a simple Corliss engine.
The arrangement of this engine, having two main crank-
shafts connected with side rods and a reel mounted on each
shaft, was necessary, owing to the topography of the ground
around the shaft where this hoist is being installed. The
only desirable location for the engine house bore such a
relation to the shaft that the two ropes from the head sheaves
to the hoist stand 12 in. center to center. With two ropes,
each Tr'i in. wide and their centers 12 in. apart, it is obvious
that it "would be impossible to mount two reels on one shaft,
as is commonly done.
The inclined cylinders and the relative position of the
tianks are such as to give practically a uniform turning
. ffort
On small compound condensing hoisting engines working
from depths of less than 1000 ft., the Nordberg company has
Obtained economies of less than 30 lb. of steam per shaft
horsepower-hour, including the steam used by the condenser,
and it is expected that the Homestake hoist will break all
records for low cost of hoisting as soon as it is put in
operation. — "Engineering & Mining Journal."
Uinms©dl Wales' Migph&s
What may well be helpful legislation is proposed by the
Washington Water-Code Commission in a bill for the dis-
tribution of unused water rights in that state, and empower-
ing the commonwealth to proceed by power of eminent do-
main to ascertain existing and proposed rights. The pro-
posed law aims at more "widespread use of the abundant
waters and creates a new department under the direction of a
hydraulic engineer who shall hold office for six years at an
annual salary of $6000. Under the provisions of the bill an
individual may exercise the power of eminent domain in the
acquisition of water rights by petitioning the state which
prosecutes the action in court and determines the rights of
the parties.
It is urged in support of the bill that existing water titles
are hazardous and that much of the water of the state is
withdrawn from necessary use by the mixed condition of
affairs. It is held that the state has enough unharnessed
water power to furnish all the heat and power now gen-
erated by coal. Capital, it is urged, declines to develop wa-
ter rights when titles are in the present precarious condition.
&.& MSEIlaini®<s
■Powell P
.©1L MsiBEtK
A dam fifty feet high that will flow the west branch of
the Penobscot River back twenty-four miles and merge three
lakes in one, is to be built this spring by the Great Northern
Paper Co.
Before anything could be done toward the construction of
this dam it was necessary to build a highway through the
wilderness from the shore of Moosehead Lake to the gorge of
Ripogenus, as in no other way could the cement and other
materials be transported to the site. Two years have been
occupied in building this road.
It is estimated that 40,000 to 60,000 horsepower can be
developed at the gorge, but the dam is to be constructed
primarily for the purpose of increasing the water-storage ca-
pacity of the west branch. The present storage capacity,
estimated at 16,000,000.000 cu.ft.. will be increased by
the new dam to 24,000,000,000 cu.ft., while at Twin Lakes,
some distance below, there has been created a storage of 15,-
000,000,000 cu.ft. Together, these storage basins will furnish
a uniform flow throughout the year sufficient for the opera-
tion of the great pulp and paper mills at Millinocket and East
Millinocket, where 1200 to 1500 men are employed and two
thriving villages have grown up,
Goiairaoirs (Gir©©Irl Pllgiir&tt of £D©1hr©att
Edlasoini
Before the Cleveland Engineering Society on Feb. 9, Prof.
C. F. Hirshfeld gave an interesting talk on the new station
now being erected by the Edison Illuminating Co., of Detroit.
A brief abstract of the address follows:
A study of conditions indicated that a new plant would
have to be installed and that economy and safety of distribu-
tion dictated a location about as far east of the business
district as the older Delray plant is to the west of that
district, with its heavy and concentrated loads. The Connors
Creek site was finally selected as meeting this requirement
as well as offering proper facilities for the receipt of coal
and an adequate supply of circulating water.
One-third of the contemplated first plant on this site is
now completed. The finished plant is designed to contain
six 25,000-kv.-a. turbo-alternators and twelve 2365-hp. boilers
similar to those now in use at Delray. It is probable that the
turbo-alternators later installed may have greater capacity
than those first contemplated.
Surface condensers, arranged for 35,000 sq.ft. of cooling
surface, have been used. These condensers are so arranged
that half of the tubes, with which the steam first comes in
contact, contain cold circulating water. The circulating pumps
are motor driven, and the air is withdrawn from the condenser
by means of a motor-driven rotative dry vacuum pump
arranged for two stages in one cylinder.
March L6. 1!M
I'd w e i;
38',
All auxiliaries, with the exception of the boiler-feed pumps,
are electrically operated, the power being preferably taken
from 1000-kw. turbo-alternators installed for that purpose.
These small units and the boiler-feed pump turbines exhaust
into heater condensers, the condensate from the main units
being used as the circulating water for these condensers.
The mixture of circulating water and condensed auxiliary
Steam serves as boiler feed. It is hoped that this arrangement
will make possible the attainment of all of the advantages
of electrically driven auxiliaries, together with the advantages
accruing from the use of steam-driven auxiliaries.
Throughout the plant many innovations of a minor char-
acter have been introduced for the purpose of obtaining
greater thermal and operative efficiency.
\3» So <Gre©l©gpcai!l S^iipv©^ ss.4 ttlh©
PgiEagisrasi 3£xrp©sa{tii©in\
The exhibit of the United States Geological Survey at
San Francisco occupies 62x7S ft. in the Palace of Mines and
Metallurgy, flanked on one side by the display of the Bureau
of .Mines and on another by the Alaskan exhibit. The cen-
tral feature is a booth, containing stage-like settings of a
scene, partly modeled and partly painted. The first repre-
sents an undeveloped district in the arid West being studied
by the Survey. Topographers, geologists and a stream gager
are at work. The second scene shows the same district after
development. The results of the stream gaging have been
utilized in planning a power plant which shows in the dis-
tance and an irrigation project which covers the valley floor.
A coal bed is being mined on one side; an oil field is under
development elsewhere; a sandstone bed is being quarried in
the foreground; mining and milling are in progress in the
mountains; a town has been built, and roads, railroads and
other evidences of civilization abound.
On recessed screens are shown pictures illustrating the
different kinds of Survey work and the part they play in the
development of the country. At one end of the space is shown
the per capita production of minerals in the United States
in 1SS0, about the time of the Centennial Exposition and of
the organization of the Survey, and in 1913. A series of
cases illustrate what our common things are made of. what
the raw material looks like, and where it occurs in the United
States; as examples, an aluminum saucepan, an electric-bulb
filament and a fountain-pen point.
At the west end of the space is an exhibit of the power and
fuel resources of the United States, including maps showing
the distribution of the black shale from which oil is derived
and the apparatus used in the field in determining the shales
that are worth studying. In the portion of the exhibit re-
lating to water resources is a display of automatic gages be-
ing run by clockwork and recording the fluctuating height of
water in a tank.
Stereoscopic pictures will be arranged in boxes of fifty
each, on a table at which one may sit and study various
features of Survey work. There are also shown four series
of pictures of the Grand Canon and Rocky Mountain region,
taken in the early days of the Geological Survey by the fa-
mous photographers, Jackson and Hillers. Other cases show
the gem minerals, the rare mineral ores, etc.
aiagf dirndl VeEaftnllsiftnoira ©,£ &h±<s
UJifiiaVeiFsa&y ©if HHMim©BS
The Department of Mechanical Engineering of the Uni-
versity of Illinois has been developing work along the lines
of heating and ventilation, under the direction of Prof. A. C.
Willard. A considerable amount of equipment for the experi-
mental study of heating and ventilating problems has been
installed within the last few months.
A recent addition consists of an air washer and humidifier
specially arranged for experimental purposes. Complete con-
trol of the volume and temperature of the water circulation
and of the air passing can be maintained. The washer is
equipped with a double bank of spray nozzles which, by means
of a finely divided mist, wash tin air passing and also cool
and humidify it. After passing the nozzles any entrained
water in the air is removed as the air passes through a
double row of V-shaped eliminators. The washer has a
capacity of 3150 cu.ft. of air per minute at a velocity of 450
ft. per minute through the spray chamber. The spray water
is circulated by a motor-driven centrifugal pump with a
capacity of 30 gal. of water per minute at a discharge
pressure of 25 lb. per sq.in.
When humidification is desired, it is necessary to saturate
the air leaving the washer, and for this purpose a steam
and water mixer of the injector type is installed in the tank
below the spray chamber. The operation of this mixer is
made to depend upon the temperature of the entrained spray
water leaving the eliminator plates. A water-temperature
regulator is placed in the path of the discharge from the
eliminators, and this automatically operates a pneumatic
diaphragm valve in the steam line leading to the mixer.
Since the temperature of the saturated outgoing air and of
the entrained spray water will be the same as they leave
the eliminators, the regulator maintains a definite tempera-
ture of outgoing air of known humidity (100 per cent.).
The temperature of the outgoing air is also under the
control of a duct thermostat which operates the pneumatic
diaphragm valve supplying steam to a tempering coil placed
in the inlet to the air washer. This coil makes it possible
to preheat the air and determine the cooling effect or "humid-
ifying efficiency" of the washer over a wide range of entering
air temperatures. As an air washer or cleanser this apparatus
is guaranteed to remove 98 per cent, of all solid matter con-
tained in the entering air. The flow of air through the
washer is induced by a multi-bladed fan with a 24-in. diameter
rotor. This fan is driven through a transmission dynamometer
by a variable-speed motor.
M©dlimcvln©ini aim ILaggfeiftainigl IRai&©§
In support of a bill to reduce residence-lighting rates from
6c. to 5c. per kilowatt hour, a schedule has been filed with the
city council of Seattle of the earnings and profits of the munic-
ipal light and power plant, after having made reductions to
6c. per kilowatt hour, and a partial report of the net profits of
the plant for the year 1914.
Since the beginning of 1911 the council has made four re-
ductions in the residence-lighting schedule. About the middle
of 1911 the rate was cut from 8%c. to 7c. and the minimum
charge from $1 to 75c. per month, and in 1912 the rate was
cut to 6c. and the minimum charge to 50c. per month.
xes^atD©
)©<ca§a©iras
After careful examination by its engineers and accountants
the New York Public Service Commission, Second District,
has approved a method for the utilization of a large water
power at Minetto, owned by the Columbia Mills, Inc., and to
be leased to the Niagara, Lockport & Ontario Power Co. for
use on its Syracuse and near-by lines, through the creation of
a new company to develop the power. The stock of the new
company, called the Northern New York Power Corporation,
is to be taken bj the Columbia Mills in part payment for its
power. The bonds, interest and principal are also to be guar-
anteed by the Columbia Mills,
Though the Columbia Mills is a corporation organized
under the business law, the Commission holds that, as it al-
ready sells a small amount of electricity to employees and
other neighbors, it comes within the definition of an electrical
corporation in the Public Service Commissions law, and as
such its ownership of the stock of the other electric cor-
poration must be approved by the Commission.
The Northern New S"ork Power Corporation is authorized
to issue $900,000 of its 6 per cent, first mortgage bonds at not
less than 97 to net $873,000. Of this sum $350,000 is to be
paid in cash to the Columbia Mills for its water rights, prop-
erty, etc.. and $ (.",5.000 is to go for the completion of the hy-
dro-electric development. In addition, the power corporation
is to issue $500, ' capital stock. This, at 125. is to be turned
over to the Columbia Mills, in payment of the balance on the
property transferred. The Commission further approves the
lease of the new company's thus acquired and developed hy-
dro-electric property to the Niagara. Lockport & Ontario Co.
The Commission has also approved a new link in the chain
of power transmission lines in the northern part of the state.
by approving franchises of the St. Lawrence Transmission Co.
to extend its lines from Norfolk to Hannawa Falls, there to
connect with the line of the Northern Power Co., and from
Hi to the Canadian bonier, where connection is
made with the lines of the Cedar Rapids Transmission Co. of
Canada, connecting the Cedar Rapids power with that at
Hannawa Falls and elsewhere through the territory.
The Commission limits the use of these lines to transmis-
sion purposes only, through the villages of Norwood, Massena
and Potsdam, and the towns of Pierrepont. Potsdam, Norfolk.
Stockholm and Massena. for which the company holds fran-
chises, but in which other local companies, such as the Nor-
wood Electric Light & Power Co.. are already doing a dis-
tributing business with the approval of the Commis
3S8
p o w ]•: i;
Vol. n. No. 11
CHARLES A. SCHIBREN
Hon. Charles A. Schieren, millionaire philanthropist and
once mayor of Brooklyn, died Mar. 10, of pneumonia. Mrs.
Schieren, haying contracted the same disease, died on the
following day. Born in Rhenish Prussia in 1S42, Mr. Schieren
came to this country at the age of 14 with his parents, who
settled in Brooklyn, N. Y. At first a cigar maker, in 1st; 4 he
went to work in the leather-belting factory of Philip F. Pas-
quay, in New York City. When his employer died in 1865.
Mr. Schieren assumed the management of the concern and
continued with the successors of the old firm until 1S6S>, when
he founded the firm of Charles A. Schieren & Co. The busi-
ness grew steadily and numerous agencies were established
in Europe, as well as in this country and Canada. In 190s
the Charles A. Schieren Co. was incorporated, and is today
Charles A. Schieren
cerns in the world.
York City, and tan-
one of the greatest leather-beltim
with factories at Ferry and Cliff St.,
neries at Bristol, Tenn.
Mr. Schieren was chief organizer and vice-president of the
Hide and Leather National Bank, president of the Germania
Savings Bank and a director in the Nassau National Bank,
Brooklyn Trust Co. and the Germania Life Insurance Co. He
was a member of many clubs and was the chief organizer
of the Brooklyn Academy of Music. During the Spanish-
American War he was treasurer of the American Red Cross
Society. In 1893 he was elected mayor of Brooklyn on the
Republican ticket. He refused a renomination.
Mr. Schieren married Louise, daughter of George W.
Bramm, in 1S65. They had eight children, fouf of whom died.
The living ones are Charles A.. Jr., G. Arthur, Harry V.
Schieren and Mrs. Albert H. Mathews.
Prof. G. A. Goodenough, of the Department of Mechanical
Engineering of the University of Illinois, recently gave a lec-
ture on "The Development of the Steam Turbine" before the
College of Engineering of the University of Wisconsin.
L. B. Marks and J. E. Woodwell, consulting engineers, 103
Park Ave.. New York City, will dissolve partnership on May
1, 1915. Mr. Woodwell will locate at S West Fortieth St..
where he will continue the general practice of consulting
engineering, and Mr. Marks will remain at 103 Park Ave.
and specialize, as heretofore, in illuminating engineering.
B. H. Bryant, civil engineer, has returned from Guatemala,
Salvador and Honduras, where he had been locating railroad
lines as chief locating engineer of the International Railways
of America, and is taking a much needed vacation in Wash-
ington, D. C. Mr. Bryant, who has acted in the capacity of
division engineer, chief engineer, construction engineer and
general superintendent of steam railroads in the United
States, Canada, Mexico, Brazil and South American countries
for many years, is well known among railroad men. He
expects to return to active work in the spring
JEHGSHEIOOMG AFFAHIRS
National Association of Master Steam and Hot Water
Fitters — The twenty-seventh annual convention of this asso-
ciation will be held at Milwaukee, Wis., June 21-24. It is
suggested that those who contemplate going to the San
Francisco Exposition can very nicely arrange to attend this
convention and continue on their way to California, while
those who expect to attend the convention of the National
Association of Master Plumbers can leave at the close of
this convention and reach San Francisco in time for the other.
InJXW fujbilecateohs
SANITARY REFRIGERATION AND ICE .MAKING. By J. J.
Cosgrove. Technical Book Publishing Co., Philadelphia,
- 1'enn., 1915. Size, S«>x6 in.; 331 pages, 45 tables; cloth.
Price, ?3.50.
The author has aimed to make the treatment graphical
rather than mathematical and theoretical. To persons seeking
an introduction to refrigeration and ice-making this book is
one of the best that has come to our attention. It will also
be a good book for many operating refrigerating engineers
for it is well adapted to giving them the ground-work in
theory that so many need. The first fifty pages are devoted
to a simple treatment of heat. We cannot recommend the
book to consulting refrigeration engineers, for, obviously,
if it is adapted to the needs of the operating man it cannot
lie well suited to the consulting engineer. For the most
part the book is descriptive of the systems of refrigeration,
their applications, accessories and of ice-making systems.
GRAPHIC METHODS FOR PRESENTING FACTS. By Willard
C. Brinton. Published by the Engineering Magazine Co.,
New York, 1914. Cloth, 7x10 in.; 371 pages. Price, $4.
The engineer has a well defined and a standardized method
of representing objects. The blueprint "language" has a
literature satisfying the simplest as well as the most com-
plicated needs. But very little information is available
regarding the best means of showing the relations between
data by the difference in the length, size and direction of lines,
areas and curves. Mr. Brinton's book, which is designed to
serve as a handbook in the preparing of charts and the plot-
ting of curves, is said to be the first dealing with methods
of graphical presentation. That a great deal of the subject
matter appeals primarily to nontechnical readers in itself
makes the book valuable to the engineer illuminating data
for a non-technical audience.
Some of the methods covered are the use of vertical and
horizontal bars, the comparisons of objects by their size or
number, map presentations, and organization and routing
diagrams. The treatment of curves, described in six of the
seventeen chapters, includes their general arrangement, the
advantages of comparative, cumulative and frequency curves,
and suggestions for executive and financial curves.
At the end of the book are given a checking list and a
set of rules for graphic presentation, the two forming prac-
tically a summary of the entire contents. The list is a set
of questions with which a curve can be checked to see whether
it comes up to the standard. The rules are suggested as a
basis for the standardizing of graphical presentations. The
chapters are logically arranged, but the headings given under
the chapter numbers in the list of contents could well have
been repeated in the text, thus definitely locating the par-
ticular heading.
The book will prove a useful aid to the many who hitherto,
in preparing charts and curves, have depended mainly on
their own ingenuity to satisfy the needs of executives as
to the information in and the arrangement of the graphical
reports rendered.
/////AV^V
Vol. 11
POWER
NEW YOI.'K. MAKCII 33, L915
<'"'">S
No. 13
and id
Chats
])©imsil Be a
agger
Results are what count, and as
long as an engineer gets them
quickly and efficiently, how he
gets them is his own concern.
Nothing on earth demoralizes
an organization and takes the
heart out of an engineer like
a manager who is constantly
changing his mind.
I
F A MAN IS HIRED to fill a certain
position, give him credit for having horse
sense enough to run his own job, at least
until he proves the contrary to be true.
By this is not meant that a manager is never to
check up the work that his engineer is doing,
but results are what count, and as long as an
engineer gets them quickly and efficiently, how
he gets them is his own concern.
No two humans were ever created exactly
alike. Such being the case, it is seldom that
any two will tackle a given proposition in the
same way — and right there is the rub.
Give a man credit for a personality and ideas
of his own, and don't tell him he is blundering
the instant he deviates from a plan you had
in mind. Forget the details. The chances
are ten to one he knows more about them than
you do, and anyway, your engineer is being
paid for the express purpose of looking after
them and relieving your shoulders of that
burden.
Don't make an errand boy of him, or reduce
him to such a state of indecision that he will
come and ask if it will be all right to have a
couple of men out Sunday to wash the boilers.
Such tactics kill all the initiative an engineer
possesses.
When you give instructions make them clear
and concise and give them to the chief and not
to some man under him, if you wish him to
maintain any discipline and have the respect
of his helpers ; and before you give instructions
settle in your own mind first, just what result
you wish to attain and then stick to it.
Nothing on earth demoralizes an organisation
and takes the heart out of an engineer like a
manager who is constantly changing his mind.
A man gets so he will exert no effort whatever
to "make things hum," because he knows that
as soon as he gets a piece of work nicely started,
in will come the boss, change his mind and
then a "patched up," "made over" job will
be the result.
In other words, be consistent. Treat your
chief engineer as if he were a man who knows
his business, and don't nag him until his head
is so busy thinking up new words to describe
your special brand of ivory that he has no time
to think of his plant, as the former kind of
"thinks" don't help the coal pile.
[Conlribultit hii Kurl A Mhji. Krnrsur</i Sin l>
390
POW E Jl
Vol. 41, Xo. 12
Adldlitioini to ftlh© Westtportt Power
By Wabben 0. Rogers
SYNOPSIS — Owing to /'; • ss the
Westpori power plant, the original capacity of
which wa.< 22,500 lew., has recently been enlarged
by putting in a 15,000-kw turbine and six w
tube boilers, each with a heating surface of 10^.70
sq.ft. The boiler furnaces are each equipped with
an 11-retort underfeed stoker. A special design
of jet condenser, so far as known, the largest built,
is used with the near turbine, and is designed to
take care of .200,000 lb. of steam per hour with a
vacuum of 28.5 inches. The brick chimney is
supported by steel girders and columns. The base
of the chimney is leeel with the top of. the boiler-
room roof, 65' ft. above the ground level.
The electric and gas business in Baltimore. Md., is eoi -
trolled by the Consolidated Gas. Electric Light & Power
Co.. and until three year- age nearly all of the electrical
energy was generated at the company's steam plant at
Westport, on the west bank of the Middle Branch of the
Patapsco River. Prior to the addition the plant had a
rated capacity of :!0.000 hp. : a small steam plant of 8000-
hp. capacity on Gould St. and a small water-power plant
at Ilehester are also operated by the company.
Although the Westport plant, Fig. 1, is tied in with the
McCalls Ferry* hydro-electric plant of the Pennsylvania
Water & Power Co.. this company is separate and distinct
Fig. 1. Showing Addition to Westport Power Hocsk
as an organization, from the Consolidated <ias. Electric
Light dc Power Co. The former company, however, has
a contract with the latter calling for the capacity of the
latters plant in ease of failure to the hydro-electric sta-
tion apparatus or transmission lines. This arrangement
also applies to the United Railways Co.. which has a
steam plant of 26,000-hp. rating that is operated in an
auxiliary capacity during the peak-load hours.
Since the contract was made with the Pennsylvania
company the electric business of the Consolidated com-
•Described in the May 13, 1913, issue of "Power."
pany has increased 150 per cent., being now 2y2 times
as great as three years ago. As a matter of prudence the
Westport plant has been enlarged sufficiently to take
care of its business in casi of a breakdown of the water-
power plant. The former equipment consisted of four
2500-kw., one 5000-kw. reciprocating units, as shown in
Fig. 2. View of thf Old Exgixe Room, Westpoet
Powee House
Fig. 2. and a ~500-kw. turbine, or a total continuous ca-
pacity of 22,500 kw. The new 15.000-kw. turbine thus
gives a station capacity of 37,500 kw. The old plaut has
a. total in boiler heating surface of 120,000 square feet.
Tubbine Room
The turbine room, which contains two horizontal tur-
bines, adjoins the engine room shown in Fig. 2. The
smaller turbine is a *o00-kw.. 13,200-volt, three-phase, 25-
cycle unit running at 1500 r.p.m. It occupies the space
formerly taken up by a vertical turbine, recently dis-
carded. The condensing apparatus of the original tur-
bine is used with the newer unit and consists of two jet
condensers, two 13xl4-in. engine-driven 20-in. volute..
pumps for injection water, and two 8&10x24x24-in. dry-
vacuum pumps, the steam ends of which are equipped
with Corliss valve-gear. One of the condensers is shown
in Fig. 3.
The 15,000-Kw. Unit and Condenser
The new 15,000-kw. unit is shown in the foreground of
Fig. 4. It is a 13,200-volt, three-phase. 25-cycle, 1500-
r.p.m. machine. The condenser for this unit is. as far as
March 83, 1915
P OWEB
39J
known, the largesl jel condenser ever built. A partial
view of one end is shown in Fig. 5 and a side view in Fig.
<>• It is desig I to take care of 300,000 lb. of steam per
hour, at an absolute pressure of 1.5 in. with 10 deg. F.
injection water, using 35,000 gal. per minute.
Used with the 7500-
K\v. Turbine
The floor space available for the condenser and air
pumps under the turbine and between the turbine foun-
dation walls was 14x15 ft. This necessitated several
departures from the usual design of jet condensers and
demanded highly efficient apparatus.
6. Largest Known Jet Condenser, Capacity
300,000 Lb. of Steam per Hour
The condenser consists of a horizontal cylinder 10 ft.
id diameter and 30 ft. long, with a 7-ft. 6-in. by. 10-ft. 9-
in. rectangular flanged exhaust opening at the top and two
G-ft. diameter wells on 8-ft. centers at the bottom. These
wells are bolted to a base plate with the condenser. The
pumps are driven by two turbines mounted on independ-
ent base plates and are located below the generator and
connected through extended shafts with flexible couplings.
These turbines at their rated speed of 1050 r.p.m. de-
velop 300 hp. each under full-load conditions.
To effect a balanced condition and uniform distribution,
the injection water is taken in at each end of the con-
denser through two 34-in. pipes running through the con-
denser shell and bolted to each head. These pipes, are
fitted with brass nozzles which direct the water against
spray plates; the water is further broken up by Stag-
gered trays with serrated edges, placed under the injec-
tion pipes. The air and noncondensable vapors arc re-
moved from the condenser at each side. This arrange-
Fig. 4. General View of the Turbine Room from
the Traveling Crane
Fig
One End of the Large Jet Condens
the Pump Turbines
392
POWER
Vol. 41, No. 12
Fig.
View at Rear of the Boilers
merit of water distribution and spray, combining the
features of parallel-flow and counter-current types of
jet condensers, makes it possible to effect close terminal
differences between the vacuum temperature and the tem-
perature of the discharge water at light and at full loads.
Due to the arrangement of the air and removal pumps,
it is possible to operate the condenser with but one set of
pumps if at any time the turbine is carrying half-load.
Boiler House
The boiler room is laid out at right angles to the tur-
bine room and contains at present six boilers each of
10,470 sq.ft. of heating surface, forming a unit designed
to furnish steam for one 15,000-kw. turbo-generator or
1.43 kw. capacity per sq.ft. of boiler beating surface.
Additional units of six boilers each will be added for
each 15,000-kw. generator installed. The present stack
serving the six boilers is of sufficient capacity to serve
another unit of six.
Two walls df the boiler house are temporary, being
made ct asbestos-covered corrugated iron, which can be
readily removed for extension. The asbestos color corre-
sponds closely with the color of the concrete in the per-
manent building walls, and the general appearance of
the structure is not marred by the temporary walls.
The boilers are set singly to allow access to both sides
of the furnace, and they are supported from the building
steel. The aisle between the rear ends of the two rows
of boilers is unusually wide, giving ample space for op-
erating blowoff valves ami for repair work (Fig. ?). The
space in front of the boilers is wide and well lighted, pro-
viding ample operating space for stokers, etc. (Fig. 8).
The building is provided with modern sanitary features
consisting of a lavatory, toilets and shower baths. Ample
light is admitted by numerous and large windows, rolled-
steel sash and wire glass being used, with ventilating
sections. A large storeroom is provided for in the base-
ment, for repair materials and supplies.
Boilees am> Stokers
The water-tube boilers are three-pass, of the water-leg
type, and are designed to operate at 200 lb. pressure.
Each boiler i- provided with a superheater of 1425 sq.ft.
of heating surface, to give 100 deg. of superheat under
all conditions of load. The ratio of superheater surface
to the boiler heating surface is 1 to T.34 sq.ft.
A balanced draft is maintained in the combustion cham-
ber by means of apparatus which controls the flue damper
of the boilers and also the forced-draft damper of the
stoker, so that a constant draft or negative pressure
is maintained. Each boiler has four blowoff valves and
an 8-in. steam delivery pipe.
Each boiler is equipped with an 11-retort underfeed me-
chanical stoker with a grate area of 156 sq.ft., this being
the area of the combustion chamber in a horizontal plane.
This gives < '» T sq.ft. of boiler heating surface to 1 sq.ft.
of grate area. These stokers are guaranteed to maintain
'Mil' the boiler rating continuously or three times the
boiler rating for a period of two hours. Forced draft
is provided by four paddle-wheel blowers directly con-
nected to horizontal engines: they deliver air at a maxi-
mum pressure equivalent to 6 in. of water.
Fig. 's. Stoked Side of the Boiler
Fig. 0. Trolley Bridge and Grab Bucket
March 23, 1915
P 0 W E It
39a
The stack lias an interna] diameter of SO ft. .3 in. and is
built of radial brick. It is supported on sis heavy
Bteel columns and 72-in. girders, the base of the stack
being 65 ft. above the foundation on which the steel is
[•allied. The height of the stark is 215 ft. above the
steel supports and 250 ft. above the boiler grates. The
foundation for the stack is a monolith 35x40, 8 ft. deep,
resting on 198 piles driven to an average depth of ~!~> ft.
Grillages of steel beams are placed in this foundation,
distributing the weight evenly from the columns to all
The new boiler house is designed to receive coal by cable
ears over a bridge from a high-speed coaling tower to be
constructed on the bulkhead line. At present coal is trans-
ferred from the system supplying the boiler house serving
the reciprocating engines.
The coal is brought to the plant in barges, from which
it is lifted by a grab bucket and transferred by a trolley
over a bridge into the old house (Pig. 9). Goal is de-
posited in a movable crusher which, after crushing, de-
livers it to the hunkers. From one of these hunkers it
^-ni'c.i.
Fig. 10. Plan and Elevation of the Most Important Piping in the New Boiler House
of the piles. The weight of the stack is 122 I tons. The
cross-section is 320 sq.ft. or 2.92 sq.ft. of .urate area to 1
sq.ft. of stack area. When the additional six boilers
are installed there will he 5.8 sq.ft. of grate area to 1 sq.ft.
pf stack area.
The steel breechings connect the Hues at the tops of the
boilers and extend in a straight line to the bottom of the
stack, which they enter by making a quarter turn upward.
The dimensions of the breeching are gradually increased
by a tapering construction to give proper cross-section for
the several boilers connected. The arrangement at the
base of the stack gives minimum friction or interference
of gases in entering.
flows by gravity into a 2-ton skip hoist which lifts it to a
hopper aho.ve the roof, From which it is discharged to a '.i-
ton electrically operated car. This ear transfers coal over
a bridge on the roof of the power house to the new boiler
house and dumps it into hoppers. From these hoppers
it is delivered into hand-push cars which distribute it to
the bunkers above the new boilers. The bunker above
three of the boilers has a capacity of 400 tons and that
above the other three has a capacity id' (100 tons to provide
for an additional row of boilers to lie installed in the fu-
ture.
From these bunkers the coal passes to automatic weigh-
ing scales, two for each boiler. Eaeh scale discharges into
394
p o w e u
Vol. 41, No. 12
Fig. 11. Ash Outlets from Ash Pits
Fig. VL Service and Heateb Pumps
a chute equipped with a distributor which feeds the
stoker hoppers, shown in Pig. S.
Ashes from the stokers drop into ash hoppers in the
basement. At the bottoms of these hoppers are 24x36-
in. cast-iron gates. Ash ears run on tracks below these
hoppers (Fig. 11) and are loaded by opening the gates
mentioned. The ashes are used to reclaim land adjacent
to the boiler house.
Piping
Fig. 10 gives a plan and section of the more important
piping in the new boiler house and turbine room. The
main high-pressure piping in the boiler house consists
of a loop of 15-in. pipe. Each of the boilers connects with
this header through a long 8-in. bend. The 15,000-kw.
turbine is served by a 14-in. connection. The new boiler
house is connected -with the old one by an 18-in. pipe line
and the 7000-kw. turbine is supplied from this pipe,
the arrangement of valves being such that steam can be
taken from either the old or the new house.
The high-pressure steam for auxiliaries in the base-
ment of the turbine and boiler rooms is supplied by an-
other lonj) header located in the basement. This header
receives steam from the main boiler-room header through
either of two 8-in. connections and supplies the four
blower engines in the basement, the steam-driven pumps
ami turbine auxiliaries.
Van Stone joints ami welded nozzles were used on all
high-pressure piping. Steel valves with monel-metal
seats were used and I'.M 1 drilling for all flanges. Re-
mote-control valves are installed on the principal units
and main connections so that some may be closed from
a control point in emergency.
The exhaust piping is located in the basement, the con-
nections from each of the auxiliaries leading to a main
24-in. exhaust line which rises to the two feed-water
heaters. Just above the connection to the feed-water
beaters a 24-in. relief valve is placed to force the steam
through the heaters and to relieve the exhaust above
a predetermined pressure.
All steam piping is covered with 85 per cent, magnesia
of ample thickness to conserve heat, and the various
classes are painted with colors that indicate their func-
tions. The high-pressure steam piping is white, ex-
haust steam bull', fresh cold water blue, salt water green,
and blowoff and drain connections black.
Two 10.000-hp. open heaters receive the exhaust steam
and deliver the hot water to a V-notch recording meter
and tank. An 8-in. vent with exhaust head is provided
for each of the heaters, to pass air and excess steam.
All of the pumps for the new boiler house are located
in the space under the stack on both the basement and the
boiler-room floor levels, this location being central for
present and future boilers.
Three boiler-feed pumps (Fig. 13) are provided, each
nf 500-gal. capacity per min. against 240 lb. per sq.in.
They are driven by 110-hp. noncondensing, three-stage
turbines at 2500 r.p.m., the pump having an efficiency of
65 per cent.
HE^
M "-
*
i
Power
Pio. 13. Boiler-Feed I'i mips
March 23, L915
PO AV E II
395
PRINCIPAL EQUIPMENT OK THE NEW EXTENSION" TO THE WESTPORT POWER PLANT
No. Equipment Kind Size Use Operating Conditions Maker
1 Turbine... Horizontal Cur- 175 lb steam, 100 deg. sup., 1500
las. 7500-kw Main unit r.p.m General Electric Co.
1 Turbine... Horizontal Cur- 175 lb. steam, 1 leg up., 1500
da 15,000-kw Main unit r.p.m General Electric Co.
2 Condensers Jet 72.O0O |h. so-am per hr With 7500-kw. turbine 2S'-in. vacuum .. Alberger Pump & Condenser Co
Fleming 12xI4-in Driving are. pumps 250 r.p.m .... Harrisburg Foundry & Machine Works
Volute discharge 20-in With small condensers Engine-driven. . . Alberger Pump & Condenser Co
Jet 25.000 gal. per mm With 15,000-kw. turbine . 2S.5-in. vacuum . .. C. II. Wheeler Mfg. Co.
Single-stage... 300-hp Driving condenser pumps. . 1050 r.p.m . Terrv Steam Turbine Co.
Thissen No. 2ll \V ith large jet condenser 1050 r.p.m C. H. Wheeler Mfg. Co.
Edge Moor 10,470 sq.fl heating surface Steam generators. 200 lb. steam, Km deg. superheat Edge Moor Iron Co.
Foster With boilers 100 deg. superheat Power Specialty Co.
Taylor S ft., 3 J in. x 19 ft., 0 in. Boiler furnaces Automatic American Engineering Co.
Steam-flow On mam boilers Continuous General Electric Co.
Automatic Weighing hopper coal Intermittent Richardson Scale Co.
1 Crane Gantty 7500-lb rapacit.t 1 nloading coal . Motor-operated Morgan Eug < ■,,
4 Engines.. Fleming 9)£12-in Driving Sirocco fans Variable-speed Harrisburg Foundry & Machine Works
4 Fans Sirocco. 9 ft. dia wl I , 3 i
wide Forced draft Engine-driven, variable-Speed
Draft-control Air control to furnaces Maintaining balanced drafl
Volute 2J-in... ... Service Motor-driven, 1420 r.p m
Induction.. "l-hp Driving service pumps 440 volts, three-phase, 142(1 r p
Induction. 20-hp Driving heater pumps .. , 440 volts, thiee-phase. 1430 r p
Supplying heaters. 2S-lh. head. 1430 I
2 Engine:
2 Pumps. . .
1 Condenser
2 Turbines...
2 Pumps
6" Boilers
'' Supel I
6 Btokers
I, Meters
12 Scales
0 Regulat
2 Pumps.
2 Motors.
3 M itors
2 Pumps \'olute
2 Heaters. ..Cochrane. .. 300,000-gal ca; r.-e.lnater Exhaust steamlroni aux. turbines Harrison Safety Boiler Workb
1 Meter... \ -notch .. .... Measuring feed water Continuous Harrison Safety Boiler Works
\mei iean Hlowel Co.
Blaiadell-Canady Co.
Alberger Pump & Condenser Co.
Westinghouse Electric & Mfg. Co.
Westinghouse Electric & Mfg. Co.
Uberger Pump & Condenser Co.
2 Pumps.
2 Engines
2 Pumps.
Turbine 5-in Boiler feed 2400
Driving boiler-feed pumps 2100
Recip 2-stl 24x24-in Dry vac. for 7500-kw. tur-
I Engine-driven
turbine-driven . . Alberger Pump A Condenser Co.
p.m., 185-lb. Steam Alberger Pump & Condenser Co.
Corliss, horizon-
tal
Alberger Pump & Condenser Co
8j24-in For dry vac. pumps Variable-speed Alberger Pump & Condens.
volute. lG-in 7500 turbine
Two service pumps, each L50-gal. capacity ]>t'r min.
against a 90-ft. head, are driven by li/.-lip. induction
motors at 1440 r.p.m. The efficiency of these pumps is
55 per cent.
These pumps supply water to two 25,000-gal. service
tanks on the roof of the boiler house, one located on each
side of the stack and supported by the same steel struc-
ture that carries the stack. This water is used for cooling
and miscellaneous purposes.
Two heater pumps, each of 1000-gal. per min. capacity
against a 50-t't. head, are driven by 20-hp. induction
motors. Each pump has an efficiency of 65 per cent.
Condensing water is supplied through a reinforced-
concrete tunnel 10x12 ft. inside dimensions and the dis-
charge water is carried away by another tunnel of the
same construction and dimensions, under the basement
floor,, but located at a somewhat higher elevation. From
the fcoller room to the bulkhead line, a distance of 26?
ft., the water is carried through two lines of reinforeed-
Engine-driven Alberger Pump & Condenser O
concrete pipe, 9 ft. inside diameter with a 9-in. wall.
These pijjes were molded in sections 15 ft. long, each sec-
tion weighing 28 tons.
The photograph shows the largest single-tandem, gas
blowing eng constructed to date in this country. It
is one of two units buiri by the Mesta Machine Co. for
the Pennsylvania Steel Co.'s plant at Steelton, Penn.,
and has ga> cylinders 46 in. in diameter, air cylinders 84
in., and a stroke of 60 in. The speed will range from 45
to 85 r.p.m., depending upon the operating conditions.
The air end is equipped with automatic plate valves
(Iversen patent) that require no valve-gear, which makes
possible the placing of the air cylinder directly hack of
the gas cylinders, so that the air-cylinder piston can 1><
driven directly through an extension of the gas-cylindei
piston rod. The engine is of the center-crank type.
Largest Single-Tandem Blowing Engine
396
row e i;
Vol. II. No. 12
eceimtt Development aim ttlne Coini<
sfbmcttiioini ©f ttlhe Uimiiffilow EmieXmie
l'.Y PROF. .1. S'lVMPF*
Since the first uniflow engine was erected in the shop
of the Erste Bruenner Maschinenfabrik, engines aggre-
gating more than 600,000 hp. have been put in operation.
This figure proves better than words can do the value of
the uniflow principle ami the Micros is the mure gratify-
ing to the pioneer, because in the beginning he had to
back the new idea against almost everybody.
Much credit must he given to the German licensees
such as Gebruder Sulzer, Maschinenfabrik Augsburg-
installed in a cotton mill. Still larger engines have been
made by Ehrhardt & Sehmer for driving rolling mills,
among which arc a 6000 and a 7000 hp., probably the
largest output lor single-cylinder engines ever made.
The standard Sulzer engines have no tail rod. Ii
required much experimental work to find the mixture
of cist iron suitable for piston and cylinder, and a large
self -upporting piston needs careful lubrication to insure
reliable operation. Other builders, like Ehrhardt &
Fig. 1. Two Views of 2000-TTp. Sulzf.t: TTniflovv Engine fob a Cotton "Mill
Nuernberg, Elsaessische Maschinenfabrik, Ehrhardt & Sehmer, use tail rods with their big engines. Taking up
Sehmer, Masohinenfabrik Esslingen, A. 6. der Goerlitzer
Maschinenfabrik and Maschinenfabrik Badenia, which
last developed the uniflow locomobile engine. Professor
Stumpf praises especially Sulzer Brothers, whose uniflow
engines show the same high-grade design ami workman-
ship as everything manufactured by this company. The
largest engine which they have buill i< one of 2000 hp.
•Abstract by W. Turnwald oi an article bv Prof Stumpf
published in the "Zeltschrlft d. Vereines deutscher Ing-enieure."
i he weigh! of the piston on a bearing surface outside
of the cylinder facilitates lubrication, the hearing surface
being small ami having low temperature; the frictioi
in the cylinder is reduced to that of the piston rings only.
insuring long life of this pari of the engine. Cylinders
for big uniflow engines have to be bored in such a way
as to make the bore uniform under working tempera-
tures.
In Pig. I are piven two views of the 2000-hp. Subser
March 23, 1915
P 0 \Y E R
Pig. i- Plan and Elevation of 2 )-Hp. [nstallation
J9S
POWBS
Vol. 41, No. 12
March 33, 1915
rOWE E
399
engine; this engine having a tail rod only because the
order called for it.
The driving parts, even those for driving the condenser
air pump, arc entirely inclosed. Forced-feed Lubrication
is used, tin- oil being supplied under a pressure of about
15 lb. by a small gear pump on the lavshaft. The pump
draws the oil from a reservoir in the basement and forces
it into the main bearings, the discharge from the oil is
collected in the crank pit and runs through a filter back
to the reservoir to be used over and over again. Cylinder.
stuffing-box and valve stems arc lubricated from a separate
oil pump, which is also driven by the lavshaft: every
feeder has its own plunger and the quantity of oil pumped
is easily adjustable. The cylinder-oil consumption of a
single-cylinder uniflow engine is of course considerably
less than that of two- or three-cylinder compound engines
All the larger engines are now built with lavshaft and
layshaft governor. The Sulzer engines have the governor
close to the head-end bearing to prevent unnecessary
deflection of the shaft. The governor acts by changing
the stroke and the angle of advance of the eccentrics.
Valve motions for uniflow engines have to he adjusted
with small lead, and since the range of cutoff is short —
only 25 per cent, maximum cutoff being required — it is
possible to keep the variation of the lead within one-half
of one per cent, or less.
Double-heat poppet valves of the type used in com-
pound engines have not proven successful with uniflow
engines, where -team tightness of the valves is imperative.
This can be insured only by making the valves as short
as possible, by making one seal resilient and by balancing
only to a certain amount, which has to be calculated.
Fig. 2 shows valves of different types, suitable for uniflow
engines. Such valves can be comparatively small. The
cutoff is short and the gain in economy by reducing the
clearance space outweighs the loss due to throttling. A
good example of this is the cylinder of a pumping engine
shown in Fig. 3, in which the clearance was reduced from
4 to 1.3 per cent, by using smaller valves, resulting in a
reduction in -team consumption of more than one pound
per horsepower-hour.
Tin- elevation and plan of the 2000-hp. Sulzer engine
as installed are shown in Fig. 4. All the piping is be-
neath the floor level, the steam pipe at one side of the
engine, the exhaust pipe and air pump) at the other. The
condenser i- connected to the exhausl belt through a
wide opening so the pressure can equalize immediately.
Qun Metal
Fig. 9. Piston of Uniflow Engine
The air pump is driven from the main shaft by means of
a crank and bell crank.
Belts are used for transmission, one for every story of
the factory. The governing of the engine fulfills all the
requirements of spinning machinery, with a comparatively
light flywheel, because the governor of a uniflow engine
control- more directly than in the compound engine where
the influence of the governor is limited to thi high-pres-
sure cylinder. The steam consumption < f this engine is
better titan that of a triple-expansion of the same size.
Indicator diagrams are shown in Fig. 15 ; noteworthy is
the shape of the compression line, which is almost
adiabatic.
An 18x2 1-in., 150-r.p.m. side-crank engine, designed
some time ago, is shown in Pigs. 5 and 8. Cylinder and
cylinder heads are jacketed, the steam for the cylindei
jackets being taken from the steam main before the
valve so the engine may be wanned up before starting it.
Pig. 10. Cuosshead of Uniflow Engine
The condenser is placed close to the cylinder and is used
as a muffler in case the engine is operating uoncon-
densing. The air pump is driven from the engine shaft
by an eccentric. The pump has no suction valves and
\er\ low clearance. The steam valve is of the resilient
type shown at .1 in Pig. 3. Bypass valves for the addi-
tional clearance -pace. Fig. ', , arc of a new type to give
400
P O W B It
Vol. 11, No. 12
the mallest clearance when operating condensing. For re-
lief valves the steam valves are relied on. The clearance
i E this engine does not exceed 1:25 per cent, when
operating condensing: The piston, Fig. 9, which is
extremely light, is made in two parts of east steel, fitted
with three rings at each end. No tail rod is used, hut the
piston has a brass-mounted hearing surface in the middle
and covering one-third (if the circumference. The piston
itself has ample clearance all around. The details of the
i rosshead are shown in Fig. 10.
It is wrong in principle to build uniflow engines for
condensing service with auxiliary exhaust valves. The
short compression is wrong and just as wrong is the
increase of clearance space and surface connected with
these valves. Even for noncondensing service, with steam
pressures as used in modern power plants, auxiliary ex-
haust valves show no gain.
Professor Naegel, of the Technische Eochschule, Dres-
den, who conducted elaborate temperature measurements
on a uniflow cylinder, says in his report: "... The
uniflow engine of the Stumpf type is able to utilize the
steam in single-stage expansion in a more perfect way
than it was possilile to do before with the best multiple-
expansion engines. The reason for this is the elimination
of the initial condensation and the reduction of heat
transmission through the walls, accomplished by the
particular flow of steam through head jacket, steam valve,
cylinder and exhaust ports, which constitutes the "Una
flow Principle."
The effect of scale on the operating efficiency of a boiler
and the difficulty and cost of its removal are factors which
have led to the design of various types of apparatus for
removing the suspended matter and scale-forming in-
gredients before the water enters the boiler. It will be
generally conceded that this is the proper method to
follow and that the solution of the problem rests in
securing a device that will do the work efficiently and
at a low cost. Quite recently, the Bayer Steam Sool
Blower Co.. of St. Louis, has given some attention to this
question and i- putting on the market the purifier illus-
trated herewith. It is licensed under Kay patents and is
made for return-tubular and the various types of water-
tube boilers.
Km. 2. Separs -im: Tank in Part Sic tion
Fig. 1 shows the purifier applied to a return-tubular
boiler and Fig. 2 shows the tank in part section. The
device consists of a cylindrical tank varying in size from
16x00 in. for a 100-hp. boiler to .">:!xl44 in., the larger
boilers being of the water-tube type. When the boiler is
in operation a circulation of hot water is set up through
the connecting piping and the tank. Any sludge remains
ill the tank and may be blown out through pipe A', while
Bayer Purifier Attached to Keturn-
TtFBULAR BOILEK
. ... -„. .__. ,.." .......
Fig. •'!. Stirling Boiler Served by I'crifier
the water is forced through an outlet at the top of the
tank and returned to the boiler through the blowoff pipe
1>. There are three forces which tend to produce circula-
tion through the system. The internal circulation in the
boiler forces the water to the rear end. and it is at this
point that pipe B inters the boiler just below the water
level. The difference in weight of the water columns
within and exterior to the boiler also tends to produce
circulation, and this is augmented by the action of the
ejector nozzle N and pressure from the boiler-feed pump.
Water thus comes from the boiler at a temperature cor-
responding to the pressure, mixes with the feed at the \
March 23, L915
P 0 W E 15
401
fitting N and discbargee against the head of the tank
through the elbow A" to obtain a uniform flow through
the tank. The latter is made large enough so that the
velocity of the water will be relatively slow, giving time
for the foreign matter heavier than water to be deposited
on the bottom of the tank. The purified water then
returns through pipe I) to the boiler. By properly pro-
portioning the sizes of pipes B and ('. the water in the
tank can be maintained at a temperature bu1 little lower
than that in the boiler. The tank will therefore separate
the suspended matter and scale-forming ingredients
affected by temperature. II' it is necessary to treat the
water, the reagent should be mixed with the feed water
before it enters the tank, so that the impurities will be
precipitated in the purifier instead of in the boiler.
Scraper .1/ has been provided to pull the deposited
matter toward the blowoff at the opposite end of the tank.
Valve F allows air to escape when first filling the tank
and may also be used for drawing off samples of water for
testing purposes.
On cither types of boiler the operation is substantially
the same. The pipe discharging to the tank is always
tapped to that portion of the boiler just below the water
line, toward which the water on the surface flows. The
return pipe is connected to the water leg, mud drum or
boiler blowoff, depending on the type of boiler. Fig. 3
shows the purifier connected to a Stirling boiler.
T\\<> sets of examination questions written from mem-
ory after the test was over:
1. How would you determine the highest safe working
pressure on a boiler of the horizontal type?
2. How would you determine the area of safety valvi —
first, lever valve; second, pop valve — required on a horizontal
tubular boiler?
3. How could you determine at whal pressure a lever valve
was set to blow off, also a pop valve?
4. How would you figure out the number of braces required
to properly support flat surfaces above the tubes in a boiler
of the horizontal type?
5. Give the dimensions for riveted joints single and double,
also the sizes of rivets required for the following thicknesses
of metal: ft in.; ;,, in.; % in. Give pitch of stay-bolts, also
size for bracing the following area: 20x32 three-eighth-inch
plate to sustain 120 lb. pressure.
6. Determine the capacity of a pump or injector necessary
to supply a boiler rated at 100 hp. with sufficient water, the
calculation to be based on the assumption that 30 lb. of water
is evaporated per horsepower per hour.
7. Give your ideas for the proper connections of water
column and steam gage to boilers. Make a sketch of same.
8. What is the best way to set two 60-in. boilers? Give
thickness of walls, spaces and such dimensions as are neces-
sary for the execution of the work. Describe the principle
of fuel combustion, the effects of sulphur in fuel, the neces-
sary elements and conditions for best results.
9. Describe what you would do in making an internal
examination of a horizontal tubular boiler.
10. Describe what you would do in making an external
examination of a boiler.
11. Give the names of the different types of boilers you
are familiar with and how classified.
12. Give the names of the principal types of boilers in
common use.
13. State what experience you have had in boiler con-
struction, repairing or operation.
14. What in your opinion is the cause of leaky tubes?
15. How would you determine the point of leakage from
an internal view of boiler, and how would you determine
if inside plate "was cracked or rivet broken from viewing
the external part of boiler where the leakage was?
16. What, in your opinion, is the cause of boiler explosions?
17. What means would you suggest to minimize the
hazard?
I. Draw a diagram showing the admission valves of a
Corliss leaking and one of the exhaust valves leaking.
'.'.. What is the effect on a cross-compound if the valves
of the high-pressure sides are leaking?
3. If the receiver pressure is too high what effect has it?
What would you do to equalize the work done in both engines?
4. How would you change the speed of the Corliss engine?
5. I 'raw a diagram of a high-speed engine, showing the
valve leaking.
6 Which would you prefer — a simple slide-valve engine or
an automatic cutoff, both having the same-sized cylinders
and to run :it the same speed doing the same work, and
why? Is there any difference in horsepower?
7. Where is the steam cut off in a pump and can the
valve motion be made to cut off in an ordinary steam pump
any earlier in the stroke.
S. On a triple-expansion engine draw a diagram showing
the intermediate admission valves and exhaust valve leaking.
9. What effect will it have on the low-pressure cylinder,
if the admission valves are leaking?
10. In a Corliss engine, what determines the point of
cutoff and how?
II. In an automatic cutoff engine what determines the
point of cutoff and how?
12. If you want to change a Corliss engine with a single
eccentric from noncondensing to condensing, what would you
do; and with a double-eccentric engine what would you do?
The chief claim for this hacksaw blade, as will readily
■ appreciated from the illustration, is its flexibility.
The blade shown, twisted into a coil one inch in diame-
NoNBREAKABLE HACKSAW BLADES
ter, was subsequently straightened out and run for the
full life of the saw teeth.
This type of uonbreakable blade is the latest addition
to the line made by E. C. Atkins & Co., Indianapolis,
Ind. — A merican Mai hinist.
: :
A Correction — Hubert E. Collins writes that he was in
error in stating in his article on an "Interesting Steam-Pipe
Installation," on page 2S8, issue of Mar. 2, that the main
which he describes was covered with 85 per cent, magnesia.
The covering used was the Nonpareil High-Pressure type,
manufactured by the Armstrong Cork & Insulation Co., Inc.
:•■:
Some Common MlffConceptionfl — A mass of aluminum
weighs one pound; a mass of lead of equal size weighs some-
thing more than four pounds. Some will thoughtlessly say that
aluminum is more than four times lighter than lead. Weight
(heaviness) is an attribute of matter; lightness is absence,
or deficiency of weight. To say that one article is a certain
number of times lighter than another is like saying of two
vessels that one is four times emptier than the other.
It might be added thai it is equally erroneous to say that
one body or substance is colder than another There is no
such thing as cold; there are only varying degrees of heat,
although we commonly regard as cold those things that are
below 9S deg. F., or below the temperature of the human
body. A substance that is at the freezing temperature is
quite hot compared with liquid air, as the latter boils vio-
lently when placed upon a cake of ice. Temperatures that
are fatal to life are far below those used in metallurgical
processes.
402
P 0 W E R
Vol. 41, No. 12
Aeit
By W
Ennts
SYNOPSIS — .1" explanation Is given of under-
lying principles and method of computing a table
of Properties of Air Saturated ivith Moisture, to
gether with examples of applications of the table.
Most engineers are familiar with the steam table, or
table of properties of saturated strain, but not as many
of them are as well acquainted with the properties of
saturated air. The table presented herewith is the result
of computations made by senior students (of the class of
1915) in mechanical engineering at the Polytechnic In-
stitute of Brooklyn : T. B. J. Merkt, Samuel Blakeman,
George Wieber, Walter L. Betts, S. Ishimura, E. P.. Ful-
ler, .Murray Harris. John DeGroot, Harvey Sand. Van
Wyck Hewlett.
Before showing Mime of the use.~ of the table, the method
of computing it will be explained. To begin with, the
word "saturated," as applied to a mixture of air and
water vapor, has a different meaning from that under-
stood when we speak of "saturated" steam. When dry air
and moisture are brought together at any temperature,
the moisture vaporizes until the vapor pressure is that
"corresponding" with the temperature, i.e., that pres-
sure which, according to the steam table, is the pres-
sure of saturated steam at the given temperature. The
mixture is then called saturated air, and the water va-
por in the mixture is saturated steam. If, however,
the supply of water is insufficient, its pressure, after it is
all vaporized, will be less than that which the steam
tables give, and the vapor, or steam, will be superheated.
From the Marks and Davis steam tables, at 40 deg. F.
the pressure of saturated steam is 0.121? lb. per sq.in.,
and its density, or weight per cubic foot, is 0.000410 lb.
With these data, we proceed to compute the properties
of 1 cu.ft. of saturated air.
According to Dalton's law, in a mixture of two or
more gases, tin- total pressure is the sum of the partial
pressures of the constituents, anil each partial pressure
is that pressure which the gas in question would exeri
if it alone occupied the total space. If our mixture i- 1
cu.ft. at standard atmospheric pressure ( 1 t.691 lb. per
sq.in.) and Hi deg., the partial pressure of the an- is
1 L69? - 0.1217 = 1 J. 5753 lb. per sq.in.
The weight of air in the mixture is computed from the
formula:
144 P 2.6986 /'
R {T + 460) ~ T + 160
II"
where
1!' = Weight of dry air in 1 cu.ft. of mixture, lb
P = Partial pressure of air. lb. per sq.in.;
R = 53.36 :
T = Temperature Fahrenheit.
The total weight of 1 cu.ft, of the saturated mixture
then
Weight of dry air 4- weight of steam, or
2.6986 X 1 1.5753
-4- o.(HlU41,=
40 -f- too
ii.o; n; + o.OOOll
(Note: 1 cu.ft. of dry air unmixed with moisture,
at atmospheric pressure and 10 deg. F., would have
weighed
2.6986 X 1 L697
= O.OT'.H lb.)
4o + 40O
The wetness, or absolute humidity, of the saturated
an' is defined as
Weight of steam -=- weight <</ air, or
0.00041 -f- 0.0787, = 0.00521.
The table shows thai as the temperature increases, the
steam pressure and weight of steam increase, while the
weight of dry air and its pressure decrease. When a tem-
perature "I' '.'1'.' ilc:. is reached, the mixture is all steam,
the aii pressure and weight are both zero, and the humid-
ity has the greatesi possible value. At all temperatures
the mixture weighs less than the same volume of dry air
would weigh at standard atmospheric pressure.
Unsaturated air contains less than the maximum pro-
portion of steam for the existing temperature. The steam
(consequently superheated) exerts a pressure p' less than
the saturated pressure p. Its density, or weight per cubic
foot, ir' is similarly less than the saturation density w.
What is called relalire humidity is defined as
t
v
Using primes to denote unsaturated conditions
P' = 14.697 — p';
and the absolute humidity
p
to = w—;
J1
U"' - »
,P'
the unsaturated air is
Some Applications
i!e ureal Gas Equation — One of the commonest for-
mulas in heat and power calculations is that relating to
the volume, pressure and temperature* of a gas:
v-V-
144 P
R {,T + 460)
as already stated ( V = volume of I lb. of gas in cu.ft.).
For dry air, 7i' = 53.36, but in nearly all engineering ap-
plications we deal not with dry, but with moist air. The
i ,-/M- i • ■ t*o*c i . 85.8 ?<■'+ 53.36 IP
value of II lor such air is not 53.36, but . , .„. .
■w + w
As an illustration, consider a mixture at 200 deg. F..
haying a relative humidity of 0.90. At this temperature.
the saturated steam pressure is p = 11.52. The partial
pressure of the superheated steam in this unsaturated
mixture is then by definition,
p' = r X P = °-90 X 11-52 = 10.368 lb. per sq.in.
The weight of 1 cu.ft. of saturated steam at 200 deg. is
w = 0.02976 lb.
The weight of steam in the unsaturated mixture is
w' = rw = 0.90 X 0.02976 = 0.026784 lb.
The partial pressure of dry air in the unsaturated mixture
P
i i.r,'.i;
l i.e.);
10.368 = 4.329 lb.
per sq.in.
The weight of the dry air is then
0.07911 lb.
P' 4 329
W' = W = 0.0130 X ,'-,.-„ = 0.0178 lb.
/I O.l I I
March S3, 1915
P 0 W E B
ioa
PifopeirtlSes ©f Air SatUasmftedl wittlh M©iis<U2S'e
At Norma! Atmospheric Pressure Pb = 14.6971b.
Note: Pb varies about | lb. per 1000 fi .if altitude. 7ut>0 grains = 1 lb.
umn T = Temperature Fahrenheit
umn A = Weight of 1 eu.ft. of dry air. 11>., = 2.6980 Pb -=- (T + 460).
iimn p = Steam pressure, lb. per s.|.in., from steam table. Note: This is the maximum pressure ' l,,ii the steam can exert at the temperature T, so that
the steam is saturated,
umn P = Dry air pressure, lb, per sq.in., = Pb — p.
umn w = Weight of sttam in 1 eu.ft. of mixture (tabular density), lb. This is the maximum weight of steam that 1 eu.ft. of mixture can contain at the
temperature T.
umn W = Weight of air in 1 eu.ft. of mixture, lb.. = 2.6986P ■=- (T + 460).
umn rp = Lb. of steam mixed with 1 lb. of dry air, oi absolute humidity.
umn w + W = W. ighf ..f 1 eu.ft. of mixture, lb.
105
106
107
108
109
110
0.0807
0.0805
0.0804
0.0802
0.0800
0.C799
0.0797
0.0795
0.0794
0.0792
0.0791
0.0789
(I 07SS
0.0786
0.0784
0.0783
0 0781
0.0780
0.0778
0.0777
0.0775
0.0774
0.0772
0.0771
0.0769
0.0768
0.0766
0.0764
0.0763
0.0762
0.0760
0 , 0759
0 0757
0.0756
0.0755
0.0753
0.0752
0.0750
0.0749
0.0748
0.0746
0.0745
ii 0743
0.0742
0.0741
0.0739
0.0738
0.0736
ii 0735
0 0734
0.0732
0 0731
0.0730
0.0728
0.0727
('. 1.726
0.0724
ii i 723
0.0722
ii 0720
0.0719
0.0718
0.0716
0.0715
0.0714
0 11712
0.0711
0.0710
0.0709
0.0707
0.0706
0.0705
0.0704
0.0702
0.0701
0.0700
0 0699
0.0697
0 0696
0.0695
0 0694
0.0693
0.0691
0.0690
0.06S9
0.0688
0.0687
0.0685
0.0684
0.0683
0.06S2
ii 0886
0.0922
0.0960
0.0999
ii miii
ii 1081
ii 1125
ii 117u
0. 1217
0.1265
n 1315
(i 1366
ii 1420
0.1475
0. 1532
(i 1591
ii 1651
n 1715
n 1780
ii 1848
ii 1917
i |989
0 2063
0.2140
0.2219
0.23(1
ii 2385
0.2472
0.2562
(i 2654
H 2749
0.2847
0.2949
0 3054
0.3161
0.3272
0.3386
0.3504
0.3626
0.3751
II l-s.s.sli
0.4012
0.4148
0.4288
0.4432
0.4581
0.4725
0.4893
ii 505
(l .-.22
n 539
0.557
0.575
0.594
0.613
0 633
0.654
0.675
0.896
ii 718
0.714
0.765
ii 7 VI
0.813
G.838
ii 864
(i 891
0.918
0.946
n 975
1 . 005
1.035
1 066
1.098
1.131
1 165
1.199
1.235
1.271
1.308
1.346
1.386
1.426
1. 167
1 . 509
1 . 553
1.597
1 . 642
1.689
14.608
I 1 605
II i.i 1
14.597
14 . 593
14.589
1 1 585
14.580
1 1 575
1 1 571 1
14.566
14.560
I 1 555
14 550
14 . .544
I I 538
14 532
14.522
14.519
14.512
14 51 5
14.498
14.491
14.483
14.475
14 467
14.459
14.450
14.441
14.432
14.422
14.412
14.402
14.592
14.381
14 . 370
14.358
11.347
14.334
14.322
14.3(19
14 296
14.282
14 286
14 . 254
14 . 239
14 224
14.2077
14.192
14.175
14.158
14.140
14.132
14.103
14.084
14.064
14.043
14.022
14.001
13.979
13 6.56
13.932
13. 90S
13.884
13.859
13 833
13.806
13.779
13.751
13.722
13 . 692
13.662
13.631
13.599
13.566
13.532
13 498
13.462
13. 126
13.389
13 351
13.311
13.271
13.230
13.1S8
13 144
13.100
13 055
13 008
12 961
12.912
0 000304
316
ii ;«i(i32.s
0.C00340
0 000353
C. 000367
0. 000381
0.000395
ii 000425
0.000441
ii 000458
M492
ii 000510
0 0 29
0.000567
O.00O5S7
0608
i 000630
n urn 65 .
;..
0.000700
0.000724
0.000749
0.000775
0.000801
0.C00828
0.000856
Ht.SV.
0.000915
0.000946
0.000977
0.001C09
0.001043
0.001C77
0.C01112
0.001148
0.001186
C. 001224
0 001263
0.001304
0 001346
(I 0615S6
0.001433
II (101477
0 001523
n 001570
n 001619
i 001670
(l (1IH723
0.001777
0.0C1832
(I IXI1SS0
(, mil, ,17
0.01 -'i « 7
0.002068
0.002131
0.002195
0.002261
12329
0.00239S
0.002469
0.002542
0 002617
0.002693
C. 002771
0.002851
ii 002933
0.003017
0.0031C4
0.003192
ii CM32S2
ii nti337t
0.003469
0.003565
0.003664
0.003766
0.003871
i 003978
ii 004087
0.004198
n 004312
ii 004 129
ii 004548
n 004671
0.004796
054
0.005187
\V
0.0802
0 0801
0.0798
i .,7', 7
ll (1795
0.0793
O 0791
0.0789
0 0787
ii 0785
ii 0784
0 0782
,, ,,7 mi
0.0778
il (1770
n 11773
0.0773
0.0771
i, 0769
0 '767
ii 0765
0.0763
ii 0761
0.0760
0.0758
0.0', 56
0.0754
0.0752
0.0750
0.0748
ii , 716
0.0744
0.0742
,, i 7H
0.0738
C.0736
0.0734
0 . 0733
0.0730
ii 0728
0.0726
n (1724
0.0722
ii 1 1721 1
0.0718
. 0716
0.0714
0.0712
0.0710
0 . 0708
il 1 1765
0.0703
0.0701
0.0699
0.0697
6 1
(i 0692
0.0690
II II6S.-N
0.0685
0.0683
0.0680
0.0678
0.0676
C.0673
0.0671
II 666s
0.0666
0.0663
1. (166(1
n 116.-.-,
0 66,33
0.0653
0.0650
0.0647
0 0644
0.0642
0 . 0639
0.0636
0 0634
0 . 0630
0.0627
0.01,24
0.0621
II II61.S
0.0615
0.0612
0.0609
0.0606
II 66,(12
0.0599
W
II 116376
(I (0.394
(I 011411
li (16127
0.00444
ii 00463
0 IK 136 1
(I 0053(1
1 61,36,3,
0 iii 586
,, 366116
II 0(1632
0 . 00657
33
C. 00709
736
0.00763
0.00793
n i ins.,,:
0.00855
' -ss
,, , 0922
O.C0956
0.00991
0.01028
0.01064
0.01104
0.01144
0.01186
II 61221
(I 01274
.. .,1326
0.01380
ii (il 111.
0.01467
0.01518
0.01572
0.01626
6 01685
0.01744
n 01805
0.01869
0.01934
II (12661
II ( 121166
II U2139
0 02222
,, 02288
II 63367
6 02447
(i ( 2535
0 02621
6 62712
ll 02804
0.02900
0.02998
0.03100
0.03204
0 03312
0.03423
0 03537
0 03655
0.03776
0 03902
0.01030
0.04163
0.04300
0 04440
0.04586
0 04736
0 04891
0.05049
0.0521
II ,6,3s
0 11316
1 6571
0 0592
0 0611
0.0652
0.0672
0.0694
0.0716
0.0739
II 11763
11 67ss
0 0813
il 0839
0.0860
w +W
n 0805
n 0804
0.0802
n ( ism i
0.0798
0.0796
1 1 '6 63
II 6763
0.0791
ii 0789
0.0788
0.0786
0.0785
0.0783
0.0781
0.0780
ii 0778
0.0776
0 "773
0.0773
0.0772
0.0770
0.0768
0.0767
0.0765
II 11763
0.0762
0.0760
0.0758
ll 0756
0.0755
0.0753
0.0752
0.0750
0.0748
0 0747
0.0745
0.0744
0.0742
(I 0740
0.0739
0.0737
( , 0735
(6 11734
(I 0732
(I 67311
0 0729
ll 6727
0 i'726
ll 0724
ll (17 22
0.0721
0.0720
0.0717
0 0715
0 0714
0.0712
0.0710
0.0709
0.0707
0.0705
0 0704
I) 6762
0.0700
0 . 0699
0 0697
(I 111,63
0 0693
0.0692
0.0690
0 . 0688
II 0686
I! lli.sl
(I 6I.S3
0.0681
0.0679
0.0677
0.0675
0.0674
0.0672
l 76
0.0668
0.0666
0 0664
(I 11662
0.0660
0 6636
0.0657
0 0655
0 0653
0.0651
135
136
137
138
136
166
167
•168
6 no.si
0.0680
0 0678
0 0677
0.0676
0.0675
0.0674
0 0673
ii 11672
0 0670
0.0669
0.0668
0.0667
0.0666
0.0665
0 0064
0.0663
II 6662
0.0660
0.0659
0.0658
0 . 0657
0.0656
0.0655
0.0654
0.0653
0.0652
ii 0651
0.0650
0.0649
0 0647
0.0646
II 6645
0.0644
0 0643
0.0642
0.0641
(i 0640
0 0639
0.0638
0 , 0637
C 0636
133
0 . 0634
0.0633
0.C632
0.0631
i 10
ii 0629
0 0628
0 0627
0 6625
0 (1624
(1 (1623
II 6622
0.0621
0.0620
0 0619
11 66,1s
0 0617
0.0616
0.0615
0.0614
0 0613
0 0612
190
0 11611
191
0.0610
192
0.0609
193
11 1161 IS
194
0.0607
195
0.0606
196
0.0605
197
II 66114
198
0.0o03
199
0.0602
200
0.0601
201
0.06C0
202
0.0600
203
11 11566
204
11 1156 s
2i 15
206
(1 11566,
.'"7
0.0595
209
0 0592
ii 0591
0.0591
■
1.886
L.93S
1.992
2.047
2.103
2.160
2 219
2 376
2.340
2.403
2.467
2 533
2.600
2 ss.5
2.960
3 037
3.115
3 . 195
5 377
3 361
3 446
3 533
3 . 623
3 714
5 S66
3 902
: '
4.098
4. '99
4.303
I Ills
4.515
4.625
4 737
i 851
4.967
5.086
5.208
5.333
5.460
5.589
5 721
5.855
5.992
6 131
6 273
6 117
6 564
6 714
6 s.,7
7 623
7 182
7 344
7 51
7.68
7.85
8.02
8.20
8.38
- 57
8.76
8.95
9 14
6 3!
9 54
9 74
9 95
1(1 17
10 61
10 <3
I I 06
11.29
11.52
11.76
12.01
12 26
12 51
12 77
13.03
13.30
13 57
13.85
14 13
14 41
14.70
12 . 862
12.811
12.759
12.705
12 650
12.594
12.537
12 47s
12 41S
12 357
12 294
12.230
12 164
12.097
12 028
I 1 657
II 885
11 si 2
11.737
11 6611
11 582
11 56J
11.4211
11.336
II 251
11.164
11.074
10 983
16 sss
10 765
li 698
10.599
III 46S
10.394
10.289
10 182
10.072
6 666
9 846
9 73"
9.611
9.489
9 364
9.237
9.108
s 676
S.842
8.705
5 56,6
8 424
8.280
8.133
7.983
7 S3II
7.674
7.515
7.353
7.187
7.017
6 847
6.677
6.497
6.317
6.127
5.937
5 717
5.557
5 557
5 137
I 657
1 717
4 527
4 307
1 087
3 867
3 167
3 177
2 937
2 087
2 437
2 187
1 927
1.667
1 397
1 127
(l S47
0.005323
0.005462
0.005605
0.005900
0.006052
0 . 006207
0 00653
ii 00669
0 00686
0.00703
0.00721
0.0C739
0 00757
0 00776
0 . 00795
0 00814
ii 00834
0 00854
ii 00875
II 66S66
II II66 1S
II 61,616
i: 00962
0.00985
0.01008
(I 01032
o 01056
0.01080
0.01105
0.01131
0.01157
0.01184
ii 01211
0.01239
0.01267
0.01296
0 01325
0.01355
O.013S6
0 6 1117
II 6144s
il 01480
0.01513
1 61516,
,, i 1580
ii 0161 1
0 01649
ii 01685
n IU721
ii 01758
0.01796
i 01834
0.01873
0 01912
II H1953
II 11199 4
0.02036
0.02078
0.02121
II 62165
0 63316
II 62255
n 112561
,, 023 13
ii 02444
'i 02544
1 1133 55
II 62617
6 I 37611
02753
ii 02807
(I 02919
0 03153
0.03214
0 65276
0 03339
0 03402
0.03466
0 03531
0.03597
0.03732
W
0.0596
,, ,1563
ii 0589
n H5S6
ii 0582
0 . 0578
0.0575
ll 0571
0.0567
0.0564
0.0560
0.0556
0.0552
0 0548
0.0544
0.C540
0.0536
0.0532
li 11.527
ii i '^:.
II 11514
0.0510
0.0505
II 6.561
0 0496
0.0491
0.0486
0 0481
0 0476
0 0471
0.0461
0 0456
0 0450
6 0445
0.0439
li 643 4
0.0428
0.0432
0.0417
0 0411
0.0405
0.0398
0.0392
0 0386
0.0380
0 0373
ii 0367
0.0360
0.0353
0.0346
0.0340
0 0332
0 0325
ii 0318
0.0311
0 0303
11 6266
ii 0288
0 0280
0 0272
0 0265
0.C256
II 621s
0 0240
0 0231
0 0223
n 6214
,| 6365
0 0196
ii 0187
n 617s
ii 0168
11 61.56
ii 0149
0 0140
0.0130
0 0120
0 0110
II 1.666
0 0089
6 61 7s
ii 0068
0 0057
0 0046
0.0034
0 0023
ii hi 12
0
w
0.0894
II 6636
0.0952
II II6S2
0.1014
0.1046
0.1080
0.1115
0.1151
I lls7
0.1225
0 1262
0.1306
0 1348
0 1391
0.1437
0.1484
0 1531
0.1581
0 1633
0.1687
0.1743
0.1801
0. 1861
0.1922
0.1986
0.2053
0.2123
0.2194
II 2367
0 2245
0 2426
0.2510
0.2598
0 2689
li 27S5
0.2884
0.2988
0.3095
0 . 3207
0 3327
0 3451
0 3579
0.3714
0 . 3857
0.4005
0.4162
6 4326,
0.4498
0.4681
0.4872
0 567 3
1 5290
0 5516
0.5758
0.6011
0.6285
0.6576
II 6sss
0.7215
0 7564
0 7947
6 B357
0 8805
0.92S6
0 9804
1.036
1.098
1.165
1.239
1 322
1 416
1 521
1 . 633
1 766
1.918
2 091
2 290
2 52S
2.822
3 177
3.614
1 187
4 940
6, 015
7 6.1 is
10.33
15,74
w + W
0 0649
0.0647
0.0645
0.0643
0.0641
0 0639
0.0637
0.0635
0.0633
0.0631
II 662s
0.0626
0 0624
0.0622
0.0620
0.0618
0.0615
0.0613
0.0611
0.06C8
j. 0606
0.0604
0.0602
0.0599
I! 6567
0.0594
0.0592
0.9589
0.0587
ii 0584
n 0582
0.0579
0 ".577
0.0574
0.0571
0 0569
(l (1.561
0.0563
0 0561
0.0558
0.0555
0.0552
0 0549
0.0.546
0.0544
0 0.541
(I 11.53 s
0.0535
,, , 3
ii 0528
0 . 0525
0.0522
0.0519
0.0516
0 9513
0.0509
0.0506
0.0503
0 0499
0.0496
0 0493
0 0489
11 ins,.
0 0482
6 "17s
II 6474
0 0471
0.0467
0.0463
0 0460
0 0456
n 0452
0.0448
0 0444
0 0440
0 0436
0.0432
0 0428
(I 0423
0 0419
0 0415
0 0410
() 0406
0 O401
II 6567
II 11362
0.0387
0.0383
n 0378
0.0373
404
P 0 W E R
Vol. 41, No. 12
about
= 0.982 cu.ft.
Si w relative humidity
u\ and ir..
Pi
The value of /?. instead of being 53.36, is then
(85.8 X 0.026784) -f (53.36 X 0-0178) _
0.u"->ljTS4 + 0.01TS
Ethel of Tvu> Humidity — If a mixture at
100 deg., having a relative humidity of 0.603 i- cooled, say
to 90 deg.. the relative humidity will be increased. The
original 1 ru.lt. of mixture will become
460 + 90
4^; 1 1 +~100
From the table, this mixture originally contained, and
-nil contains 0.60 ■ 0.002851 = 0.001711 lb. of moist-
ure. The maximum amount which it could contain, if
saturated, at 90 deg., is 0.982 X 0.002131 = 0.00209 lb.
The new relative humidity is then 0.00K 11 -f- 0.00209
= 0.S-.'. Cooling might be carried on to a point at
which this figure would exceed 1.0. when some of the
moisture would separate out as liquid dew. [n symbols,
Pi'«i / Tx + 460\
Pi "•> \7'-> + 460/
where
Tx and T2 = Initial and final temperatures, n
tively :
Corresponding tabular densities;
Tabular steam pressure for Tx;
Partial steam pressure of the unsatu-
rated mixture at Tl.
Frosts — On a tool night in spring or autumn, the prob-
ability of a freezing temperature before morning depends
largely on the relative humidity of the air. If this is
high any considerable cooling will be likely to increase
it beyond 1.0; that is. to can-.' a condensation of vapor
as dew. Such condensation, the reverse of evaporation
(which consumes heat), liberates heat and thus tends to
keep the temperature from falling further. With a
stated temperature at midnight, then, other things be-
ing equal, a freezing temperature before morning is less
likely to be experienced if the relative humidity is high.
v
Aiff aim Jeft^Coimdleiases3 Ptraieftiice
By Everakd Brown
While most of the larger steel works and other manu-
facturing plants operate many engines condensing, it i>
surprising to note the universally poor vacuum main-
tained. The range seems to be from ".'1 to 24 in., and ii
i- seldom one finds an installation carrying 26 in. Mani-
festly, this condition <]>^> not obtain from choice, but
rather because of the apparent difficulty, or impossibility.
of doing better with the equipment in use.
It might seem that the type of equipment employed i-
at fault because the jet type of condenser is preferred
for general mill purposes, both for central installations
serving a number of engines ami for individual units.
That this is not the case is evidenced by the fact that
thi re are installations where condensers of this type, both
barometric and low-level, give as good results, for the
service, as the surface type.
Inquiry among mill engineers as to the reason for such
poor vacuum will usually elicit the reply that either
there is leakage m the exhaust piping or the air-removing
capacity {,\' the equipmenl is too small. To those not
familiar with mill-operating conditions, the former rea-
son will no doubt appear inexcusable and reflect on the
diligence of the engineer in charge, while the latter will
reflect on the manufacturer of the condensing equipment
lor not supplying a sufficiently large air pump. Full
realization of what the mechanical department in a manu-
facturing plant often has to contend with will materially
lessen any blame for leaky piping. The blame can be laid
at the door of the condenser builder more often, because
In- has not given proper consideration to leakage. Per-
haps em- of the reasons for this is his eagerness to get
the order for the equipment, and by offering a smaller
air pump he can keep the price down to an attractive
figure. Should he get the order and it is found that the
air pump is too small, he can always claim that there is
excessive air leakage. This is bad practice because the
bidder takes advantage of the purchaser, who usually be-
lieves that an air pump will be furnished of sufficient
capacity to take care of at least a reasonable amount of
leakage.
It may also happen that the bidder is not given suf-
ficient reliable data as to operating conditions, in which
event he can only base the size of the air pump upon
the theoretical quantity of air that will enter the eon-
denser, pin- a certain percentage for leakage which, of
necessity, can only he a vague assumption. As a eon-
sequence, the amount of this leakage is usually underesti-
mated and the air-removing capacity of the condenser
made too small.
Proposals tor a certain-sized condenser plant were
submitted by three different bidder-, all based on the
same set of specifications. Taking the proposal offering
the largest air pump as a standard, it was found that one
of the other bidders offered a pump of half the capacity
and the third a pump of about two-thirds the capacity,
based on an equal number of revolutions for each, which
is probably a- fair a way of making a comparison as
any. because it is a comparison of the durability of the
pumps. It is doubtful if the pump having the largest
air-removing capacity was large enough, so that it is ob-
\ ious what the result would be if one of the smaller pumps
were put in. The speed at which a pump operates con-
trols its capacity, and in the above instance it was in-
tended that the smaller pump should run at a higher
speed, which brings up the question of relatively high
maintenance i ost.
It would seem that condenser builders have established
certain standard sizes of condensers and air pumps for
handling given quantities of steam, apparently without
due consideration of varying conditions. They can, of
course, estimate with accuracy the amount of air that
enter- with the steam and water, provided there are no
unusual conditions with which to contend: and experi-
ence should have told them long ago how- much additional
air-pump capacity is required because of unpreventable
leaks.
The secret of a satisfactory condenser installation
hinges primarily on the question of air removal, which
means an air pump of sufficient capacity to take care of
any reasonable amount of leakage. Oftentimes this leak-
age cannot he prevented because of local conditions, or
its prevention proves more expensive to bring about than
the cost of the extra steam required as a result of a poorer
vacuum. How much better it would lie to install an
amply large pump and run it slowly during the colder
weather or when the out lit is new and more efficient,
and then, it necessary, speed it up a little as leaks be-
March 23, 1915
P 0 W E E
-10.3
gin to develop or as the hoi weather sots in. Such an
installation will also provide capacity for future increase
in load mi the condenser, a contingency which often arises
in mill practice where increasing the load on equipment
is common.
It will require a little more steam to operate a larger
air pump, hut when compared to the losses due to a poor
vacuum or to the cost of maintaining an air-tight sys-
tem, this becomes quite insignificant. A use for this
extra steam as it is exhausted from the air pump can
nearly always be found it looked for: such. I'm- example,
as heating feed water for boilers, an avenue thai olfers a
chance for considerable saving In power costs and possi-
bly one which lias been overlooked in many cases.
Tesft ©if a*. 31(
rir&jsLBini©
By ('has. S. Salfeld
Some time ago a 16-hp. Fetter two-stroke-cycle semi-
Diesel oil engine, made at Yeovil, England, was shipped
to this country and subjected to a series of tests by the
writer. The engine is of the single-cylinder, vertical,
crank-case compression two-port type, 9%-in. cylinder
bore by KM L.-in. stroke and running normally at 325 r.p.m.
It is provided with a flywheel weighing 1000 lb. and sup-
ported by an outer bearing. The exhaust ports open and
(lose at ;."> per cent, of stroke and the scavenging ports
at 88 per cent.
The fuel-injection pump, owing to wedge regulation,
commences to inject at varying times, according to the
load. At maximum load this occurs at about 46 deg.
before the upper dead center; at rated load about 34 deg ;
and at smaller loads, still later. The end of the inject ion
period is constant at all loads and is reached when the
crank has almost completed the compression stroke, that
is, about 5 cleg, before the dead center. The governor
raises and lowers a wedge interposed between the pump
lever and the pump plunger and thereby graduates the
impulses according to the load.
The cylinder head is an adaptation of the well known
Hornsby-Akrovd principle. Its upper part, against which
the fuel is sprayed, is uncooled but usually remains black.
No hot bulb of the generally accepted term is employed,
hut to facilitate starting a short nickel tube is provided.
Water injection into the scavenging port is furnished,
although it is not supposed to lie used up to the rated load.
The engine is one of several British makes which are
widely advertised as being capable of operating with a
fuel consumption not exceeding one-half Imperial pint,
which would be equivalent to 0.6 U. S. pint, or 0.075
U. S. gal. While the writer is convinced that such
economy can be and is obtained with thoroughly well
designed engines of this class, neither he nor several of
his assistants were capable of realizing such consumption
on this particular engine. The very best they ever ob-
tained, but not by any means the average, was 0.597
lb., or 0.0886 I'. S. gal. .if 12.5-deg. distillate, which is
an excess of 18 per cent. The cause was noi far to seek
and presented itself in the unreliable performance of the
fuel pump and injector. Further satisfactory character-
istics of the engine are its capability of operating without
Water injection even beyond the rated load, its high me-
chanical efficiency, and the equally high volumetric effi-
ciency of the crank-case air pump.
Particularly by eliminating the water injection have
the makers solved a problem which, id' late, has heen a
source of considerable trouble and anxiety to a. number
of manufacturers. This has heen done partly at tin1
expense of power output. Fntil early in 1913 this size
of engine was rated at 20 b.hp. and water injection was
used. The makers then decided to rate it at 1G b.hp.
ami abandon the use of the injection water. The writer
operated the engine at the maximum load the governor
would permit, namely, S3 b.hp., then removed the governor
wedge so that more oil could he admitted, and it was
evident that a considerably higher horsepower might yet
have been developed with water injection.
During the principal trials the fuel used was distillate
of 0.820 sp.gr., or 39.5 deg. Baume. Tests with crude oil
and with fuel oil were also made, and these will be found
appended. The first named tests gave the following-
results :
Appro*. Load
B.hp
Rp.m
M.e.p 1
Net i.hp
Net raech. eff. . .
Oil per b.hp
4.025 8.1
335 335
14.0 19.fi
9.3 13.0
43.3 62.3
%
12,3
335
24.6
16.3
75.6
%
14.9
334
29.2
19.3
77.3
16.45
334
30.1
19.9
82.7
0.613
15
22.1
318
38.5
24.25
91.1
0.635
0.636 0.627
The average volumetric efficiency of the crank-case
air-pump was 80.4 per cent., which was practically con-
stant at all loads. At maximum load (22 b.hp.) the
scavenging pressure was 3.(1 lb. per sq.in. and the com-
pression pressure 1 1<> lb. The explosion pressure varied
from 250 to 318 lb. and the exhaust pressure was about
28 lb. ,
The following test was carried out with Peruvian crude
oil ,,r 0.895 sp.gr. (26 (leg. Baume), 105 deg. F. Hash
point, and 18,001 B.t.U. per lb.:
Fuel per B. Hp.-Hr.
i; tie
R.p.m.
LI..
U. S. Gal.
16.4
334
0.625
0.0S37 With injection wat
16.3
332
0. fills
0.085 1
15.5
335
0.618
ii 083
14.::
338
0.626
0.084 [ Without injection
10.0
340
5.761
0.102 water
5.2
344
1.23
0.165
0
345 5.42 per hr.
0.72
fi per hr. J
The
consumption of
28
deg. fuel oil (0.886 sp.gr
was as
follows
r- Fuel per B. Hp.-Hr.-,
Lb. U.S. Gal.
B. Hp
R.p.m.
15.9
322
0.646 (ins;
14.9
324
0.676 0.091
9.5
5.1
325
334
0.893 0.121
1.33 0.1S
'I'he best consumption obtained with 12.5 deg. distillate
was :
;. Hp.
R.p.m.
Fuel
Lb.
per
B. Hp.-Hr.
U. S. Gal.
British Im-
perial Pints
15.1
13 8
9 85
5.1
326
328
: |
333
n 597
0.606
0.703
lira;
o.oss
0.089
0.104
0.217
0.59
0.59S
0.694
1.435
The regularity of running was satisfactory except at
no load, when considerable '"hunting" occurred. This
was not >\\\r to any defect in the governing apparatus,
but to insufficienl heat in the combustion chamber, the
compression pressure of 1 to lb. apparently being a little
low. Nor did this ■•hunting" occur with all fuels; with
crude oil it was altogether absent, but with fuel oil and
with distillate it was distinctly noticeable. A throttle
valve on the air inlet would have been a remedy, hut
none was provided. The exhaust was visible with all
fuels and at all loads, hut was in no way objectionable.
406
row e it
Vol. 41, No. 12
]£iB?©c& ©f Teffimpeiraftuaire oira C®.p^=>
city ©if (Ceim&ff'aif'imgfal Piflfflnvjps
By Job \ How \i;i>
At a recent test of a centrifugal boiler-feed pump an
opportunity was afforded to determine the effect of vary-
ing temperatures upon the capacity. It was a standard
Piatt 3-in. three-stage pump, driven by a Terry steam
3100 "£
i
3000 £
'6
•+-
2900 £
c
£
o
£800 «;
£210
195
0 40 80 120 160 £
6<allons per Minute.
Fig. 1. Capacity Test mi: Constant Head ami
Constant Speed
turbine, and designed for 150 gal. per nun. againsl 1!»">
lb. pressure at 3000 r.p.m. As the head on the suction
was only about 30 in. above the center line of the pump,
the builders would nut guarantee to handle water at a
temperature greater than ISO deg. F. The water was
measured by a G. E. flow meter which was afterward cali-
brated and found correct.
The capacity test gave the results for constant head
and for constant speed, shown by curves in Fig. 1. The
^s
k,
s^,
^>
Jfi}£
N?.
*
Speed Constant at 3020 R.p.m.
Presi
ure
195 Lb
170
100 l£0 140 160
Gallons per Minu + e.
Pig. 2. Results of Temperature-Capacity Test
first curve was obtained by the use of a pump governor,
and the second when the governor was cut out, the ca-
pacity being varied by throttling the discharge.
In order to make the temperature-capacity test, the
temperature of the Mater in the open heater from which
the pump took its suction was varied by controlling the
amount of steam passing into it. The result is shown
by the curve in Fig. 2. The great variation is undoubted-
ly due to the extremely small head on the suction side of
the pump.
While the guarantee was for only 180 deg., it was found
that by speeding up the pump somewhat, water at 190
deg. could be handled safely.
BvuinSdlaiag
By Ai.i'iikd A. Winter
At a time when we are all interested in figures on eco-
nomical power costs, based either on theoretical calcula-
tions or test results of newly constructed uptodate equip-
ments. I venture to show cost figures from an out-of-date
plant, such as a large number of engineers have in their
care. These figures are not record breaking, and no doubt
some who arc skilled in obtaining real efficiency will throw
up their hands in dismay. But the thought that it is
sometimes well to sec ourselves as we really are, impels
me to -how our figures for 1913 ami 19] 1.
The plant has two Babcock & Wilcox boilers (total nor-
mal rating 475 hp.) equipped with Murphy furnaces, and
one deck tubular boiler, flat-grate, 150-hp. in reserve, and
two high-speed, single-valve engines — one a 22xl8-in. and
one a 1 lxli-in., also a 10-kw. direct-connected unit for
night lighting, as the plant runs only in the daytime.
The larger engine has two driving pulleys on its shaft,
one running a belt drive through certain of the buildings
and one driving a 100-kw. belted generator.
The smaller engine is direct-connected to a 75-kw. gen-
erator. The power is about equally divided between shaft
and electric drive and is used for various purposes of
manufacturing, this being a property with tenants, to
whom power is sold.
POWER COSTS FOR 1913 AND 1914
Items
Taxes
Insurance
Water rent
Coal
Labor (operating )
Labor (extra repairing)
Supplies for operating repairing —
Oils
Packing:
Boiler compound
Boiler-room supplies
Furnace and stoker supplies
Pipe, valves and fittings
Lumber and mill work
Sand, cement, stone and lime...
Electrical supplies
Tools
Hardware
Miscellaneous
Repairing (outside labor) —
Boiler, furnaces and stokers.
Engineer and pumps
Electrical
Belts
Roofs, spouts, etc
Stack
Pipe fittings
Miscellaneous
1913
1914
$r,62.r.o
$562.50
225.00
225.00
500.00
500.00
6,420.45
5,305.65
4,144.00
4,151.50
503.45
373.01
171.66
136.34
47.71
13.26
136.50
134.62
51.05
68.80
2(54.35
49.31
119.44
3.58
9.35
32.42
43.56
14.07
40.04
4.71
13.90
34.13
2S3.10
314.13
133.30
12.00
111 ss
7.5 5
24.50
38.58
315.30
324.00
3.50
50.30
$13,S90.0C
$12,489.00
1,500.00
1.500.00
$15,390.00
$13,989.00
Total operation and repair expenses
Depreciation on $37,500 (4 per cent.)...
Total $15,390.00
Horsepower 1913
Generated at boilers 42S
Loss — condensation, friction and transmission 85
Delivered to tenants 343
Cost at boilers i without depreciation account) $32.50
Cost at boiler (with depreciation account) .... 36.00
Cost delivered to tenants (without depreciation
account) 40.00
Cost delivered to tenants (with depreciation
account) 45.00
297
$33.00
4 2.00
17.00
March 23, 1915
POWEB
407
v&g.
ir© => IOecthriic
By J. .M. Wanchope
Two power plants were recentlj installed by a mining
company in northern Idaho, which are normally oper-
ated withoul attention, excepl once a day when the mine
ician looks them over.
The company buys most of tin- power used in its mine
and mill, it being delivered at 2300 volts, three-phase.
Having several water rights on small streams, it was de-
cided to put them to use. One lueation was a short dis-
tance from the mine, where a head of too ft. with suffi-
cient water to develop 150 kw. could be obtained. Another
was found where, by utilizing three small streams with
heads of 100, 160 and 250 ft., respectively, sufficient
water to develop another 150 kw. was obtained.
The waterwheels used were of Pelton type with belt
drive to the generators. As the plant had three heads,
three wheels were secured to one shaft, each being adapted
to a different head. The nozzle of each wheel was fitted
with a deflector to direct the water from the wheel with-
out stopping the flow.
Each -plant was fitted with a common flyball engine
j riior. driven by a belt from the wheel shaft and so ad-
<l that with a rise in -peed of from 5 to 10 per cent.
normal a small weight was released, which in falling
released a heavy one. This was so connected to the de-
flector lever that the latter was moved to a position to cul
off the water from the wheel, causing the unit to stop.
The generators operate in parallel with the power
company, feeding into the mining company's lines on the
customer's side of the meter, thus decreasing by their out-
put the power purchased. The electric company thus
provided the governing, as the generators were operated
under constant load, the nozzle being set according to
the amount of water available.
Automatic -witches were used for the generator^ with
no-voltage and overload trips on them. In case the
electric company lost their load the effect was practically
the same as a short-circuit on the small plants, due to the
heavy load thrown on them. The switches would then
instantly open, and the wheels and generators would start
to speed up, causing the trip on the flyball governor to
release the weights which raised the deflectors, thus shut-
ling down the units. Of course, when this happened the
electrician at the mine or mill knew that the load had
dropped and started the units up again as soon as
the power company had returned the voltage to their
line.
As tin' mining company was hilled for the power used
partly on the maximum amperes drawn from the line of
the power company as determined by a graphic ammeter,
it paid the mining company to keep the peak as low as
possible. The two plant- were operated with a Leai
power factor up to the capacity of the generators in cur-
rent, to keep the current drawn from the line as near
unity as possible, the mine load being composed of in-
duction motors and naturally lagging. Power-factor me-
ters were in-tailed at each plant and in the substation of
the power company on the mining company's feeder. The
plants operated nicely under these conditions. There
would have been no return- if an attendant had
kept at each plant, hut under the conditions as stated they
returned a fair interest on the investment.
[More stories at stupidity an <mpeting
with "Some Original Ideas," as printed Jan. 19, 1915.]
Still Thirsty
A chief of a small electric-light plant, being somewhat
dry on sundry occasions, decided to tap the line leading
to hi- boiler-feed pump, where cool palatable water was
being handled. What was his surprise to find hi- dipper
dry! He had tapped the suction which operated under 12
or 1-1 inches of vacuum. — •/. 1!'. Fowlkes, Denver, Colo.
Now It Surely "'Has Came'
El' Dorado Republican Mountain fltmornt
»nd Weekly Nugget/
Proprietors iod Publisl.e
. NEW POWER MOTOR
A New Power-Creating Motor.
No Eilernil Ener(y Required.
jflountoin JlemturaJ
• ■' ■ i ■ i I ■■ , ■ I <ai und ■nddnppcd un n
maile um. or. i \t . !,rtf- 0,d? »s it >
It ...nil t* railed « "-her! «,thin ^Dat^U^l^ialik »nd rh
<
I woond-op ud
' ', - "
e .!..,.
tr eenennng eleciricU, »t i no.ni
Sheapli for Irritating firm tind. to
r r»r o,»,oB ! „„.l
the motor t. if"
t „ 'i.l.raK '•'
(Reproduced (Tom clippings received anonymously)
Where 'i he Water Went
It i- accessary to carry a rather high pressure of steam
at the Depot building here, and the water comes hack so
hot that -team comes out of the overflow, which I can close,
a- it i- in the boiler room.
One night, while 1 was cleaning fires, the tank ran dry
and I opened the make-up valve, leaving the overflow
closed, which backed the water up in the return pipe. On
discovering my mistake I opened the overflow and relieved
the pipe. In the meantime the car inspector had tapped
the pipe in the building to heat wash water and. having
plated hi.- bucket of water and turned on the steam,
stepped outside a moment. On returning he found the
bucket empty, and accused his partner of emptying it.
Although lie is supposed to thoroughly understand steam
heat, he -till content]- that his partner, instead of the
the water.
This is amusing, bul not the most stupid occurrence
that has come under my observation. — Willis W. N<
108
P U W E E
Vol. 41, No. 12
Concrete
Foundation ,
2&fcj
Fig. I. Leaning Chim-
ney in Brooklyn,
100 Ft. Higb
A. JLeasaanag* Cfeilmniiraey PlUassmlbedl
By Tikim is s. Clakk*
Many methods have been employed to bring back
to the vertical position tall columns such as chim-
neys, shafts, towers, and the like, which have leaned
or settled « >ui of plumb. The
procedure has often been very
expensive and hazardous as
well as slow. In the ease of
chimneys it has compelled
shutting down the boilers and
a consequent loss in output of
the manufacturing plant. A
new. unique and inexpensive
method was recently em-
ployed to straighten quickly a
100-ft. factory chimney in
Brooklyn, X. V., without in-
terruption to the plant.
The Problem
Under one side of the foun-
dation the soil had softened,
and settlement, had taken
place, due to leakage from a
water pipe near the foot of
the foundation, whose exist-
ence had been Eorgotten. Fig.
1 shows the leaning chimney.
To excavate on the low side
of the foundation to the depth of the footing course, crib
under it, and attempt to jack the structure back plumb,
would have involved large cost, loss of time, and not a
little risk. The greal weighi of the 100-ft. column and
the additional pressure due to the
leaning would have required pow-
erful jacks and a substantial Foot-
tng to jack against. There would
have been danger also of cracking
the mi reinforced spread founda-
tion, and additional foundation
would have had to be placed be-
Fore i In' jacks and cribbing could
have been removed safely.
Another method to straighten
a leaning chimney, employed to
some extenl in Europe, is to saw
out a course or a portion of a
course of brickwork on the side
of the columns away from the
direi I ion of lean, in wedge-shape,
with an ordinary two-man cross-
cut saw, and allow the portion of
the chimney above the cut to set-
tle back. This method is, to say
the least, not entirely satisfactory nor does il remedy the
defect entirely, as the portion below is still out of plumb
and the bearing surface of the foundation footing is no1
brought to the horizontal. For these reasons these two
methods were abandoned.
The chimney was in operation, so it was no! possible to
determine the amount of its lean by plumbing to a center
on the inside. The deviation from the vertical was there-
fore determined with a transit by a simple triangulation;
it was found to be l.sl/2 in. From this figure, with the
known height of the chimney, it was determined that the
toe of the footing on the high side must be settled 2%
in. on a line exactly opposite the direction of the lean.
The problem was to remove just enough earth between
the center of the foundation and the toe of the high side
to gradually settle the foundation back 2% in. at the toe.
Levels were taken on the high side anil an indicating
plumbline fastened to the side of the chimney.
How in i: Wore Was Done
A trench was excavated on the high side to the depth of
the foundation, about -4 ft., the length of the trench equal
to the square side, and its width equal to half the width
of the foundation, or about 8 ft. Four 2-in. wrought-iron
pipes, 8 ft. long (half the width of the foundation), were
sharpened sawtooth fashion at one end. These pipes were
successively driven under the high side of the foundation
near its center (Fig. 2). then withdrawn, and emptied of
the material in them by driving a steel rod through the
pipe. Successive insertions were made about a foot apart.
As the pipes were withdrawn, the adjacent earth crushed
into the holes left.
In this way but a small quantity of earth was removed
at a time, and but a small quantity gave way at a time;
the yielding occurred just where wanted. The chimney
settled back gradually, with no shock or no danger. The
amount of settlement, its direction, and the rapidity of
settlement were always in absolute control. The telltale
plumb-bob gave the direction as well as the amount of
movement.
A1 one period of the operation the chimney began to
settle slightly out. of line. It was only necessary to drive
•Engineer, Alphons Custodis Chimney Construction Co.,
99 Nassau St., New York City.
Fig. 2. Method of Removing Earth dndek High Side to Bring the
Chimney Rack to Plumb
the pipes more often at a certain point to bring the shaft
back to line.
When the column was again plumb the trench was tilled
up. The underground leak in the drain pipe had been
previously stopped to prevent further softening of the
earth on one side. The chimney has since remains!
intact.
The work was done by the Alphons Custodis Chimney
Construction Co., of New York. The method was devised
by the writer. — Engineering News.
March 23, 1915 P o \V E 11
m i. i mini iiiiiiiuiNiiiiiiiiiiiiiiiiiiiiiNiiiiiiiiiiiii imiiiiiiiiiimu iiiiiiiii imiiiiniir
40!)
Editorials
ainiiiillllilllllllliil 'iiiiiiiii iiiiiiiii iiiii i mil i mi mini iiniuiii iiiiiiiiimin iiiimmii u urn imm, n i n ■<•■ m §
Tlh© Km$»nm±<e<BT ,mft Ftmlbllac
Operating engineers seldom have U> address legislative
committees, public-service commissioners or municipal
officials in formal hearings, but when thej do it is worth
while to know how to do it. As a class, engineers arc
men of deeds rather than of words, while lawyers are
fairly characterized by the latter qualification. It is not
easy to carry a petition successfully through a public body,
and the causes which tend toward failure in this direction
deserve careful consideration.
Engineers seeking legislation or other regulatory action
must first of all present their cases upon the solid founda-
tion of facts. Hearsay evidence cuts very little figure with
the average committeeman, but a few essential facts and
figures throwing light upon the problem in hand, set
forth in a plain, logical way, will do wonders in com-
manding a respectful hearing. Often it pays, no doubt,
to club together and retain counsel to look after the
legal side of proposed measures; hut above all. it is
essential to stick absolutely to known facts and conditions
and not to attempt to strengthen the case by introducing
evidence of uncertain nature. It is better to say "I
don't know"' a hundred times in a forenoon before a
committee, when the witness or proponent of a measure
is not fully informed, than to try to "bluff through" on
suppositions — a lesson that is none too easily learned in
other walks of life.
A fair degree of consideration for the views of one's
ments is desirable, so far as it doe- not jeopardize the
objects of the petitioners. Thus, a hill may he drawn to
limit central-station rates in a way that will make life
more tolerable for the plant engineer. The latter ought
to he able to gain his object without attacking the
desirability of giving existing capital a reasonable re-
turn. In advocating any measure the proponents ought
to be prepared to meet the question of its effect on present
business organizations. One of the greatest defects seen
in legislative committee room- i- the inability to see more
than one side of a question — a defect which narrows the
character of evidence presented and often leads to disaster
when the finding comes through. The engineer cannot
be expected to present a case with the skill of a Webster
or a Choate, hut he can certainly make sure of his facts
ami stand on those, even in the fa.e of severe cross-
examination. Restraint in advocating any cause goes
further than excessive one-sidedness.
Recent observation of the work of engineers in hearings
emphasizes the importance of presenting only pertinent
data, of avoiding tempting side-issues and personal
grievances not affected by the proposed measures, and
"I putting in evidence hearing toward a definite demon-
stration of the need for a given hill. The burden id'
refuting a measure may lie thrown upon the engineers'
opponents in many cases. The avoidance of needless
work is as important as tin- presentation of facts hear-
ing directly on the matter in hand. Mere assertions that
•> hill is desirable count for little. Cooperation is ab-
solutely essential ill ••framing up" a proper line of attack
in supporting legislation on behalf of the engineer, and
simple, direct methods arc invaluable in dealing with
public authorities.
inhere 2s H© IRoyavl IFl©adl
Knowledge is not to he found by waiting with idle
brain and hands. Knowledge may he acquired only by
those whose desires are sufficiently strong to urge them
to make the effort, both mentally and physically, to win it.
The fields of knowledge are unfeiieed. There are no
barbed-wire entanglements to obstruct the way, no
trenches across the road, to he won only by fixed bayonets
and the strenuous charge or spectacular bravery. Neither
is the road to knowledge the velvet-covered royal way made
smooth by the toil of others. He who seeks must build the
road for himself. Each step means the expenditure of
time and effort, with no limit upon the results that may
be attained, except the self-imposed limitations of the
seeker.
The means of acquiring knowledge are within the reach
of all. Free libraries and leading rooms are open to all
who care to enter, and in them may be found hooks and
periodicals covering almost every subject. Attendant-
are there who will inform the seeker where he may find
books and articles upon the desired subject. A letter,
costing two cents to mail and inclosing a stamp for a re-
ply, will bring an answer or suggestions as to where the
answer to nearly any question may he attained, not ob-
tained. The printing press has made hooks low in cost,
and reasonably few are required to cover any one line of
research. Hut no hook is id' any use until taken from the
shelf and opened. Ace- ago someone said. "You must
' n ep before you can walk, walk before you ,-an run." The
aviator doc- not jump into his machine and immediately
reach the height of the clouds. The tower is not started at
its full height and built down to the ground.
In building the tower the first step is excavating for
lis foundation, by clearing away the soft, springy surface
to a linn footing. A foundation must he laid before the
builders are ready to -tart on the tower. The aviator
starts hi- machine on the ground and gradually rises.
In learning to walk each step in advance mu-t he made by
itself and completed. There is no short cut; no royal
road. Experience i- the onh real teacher. Tin- highei
branches of any subject cannot he understood until the be-
ginner has learned to understand the fundamentals of that
siihjci t. ha- learned to reason, ami cadi one must learn to
think for himself. No power outside of tin' individual
tan cause Ins brain to work. No power can teach unless
the brain is ready to receive and able to understand. One
may he able to repeat a rule, parrot-like. Word for word,
hut Hides- the reason for that rule is clearly understood
it is of little value, for it cannot he applied with intelli-
gence.
410
row ]•; b
Vol. 41, No. 12
How many engineers can show a blueprint or any
kind of a plan of any portion of their plant, or of any of
its equipment? How many have a list of the machinery
in their plant, giving information in regard to its size,
date of installation, make and purpose? Yet without
these, they cannot promptly answer requests for informa-
tion from the head office.
Construction plans showing the relative locations of
pipes and the different pieces of apparatus, of electric-
wiring ducts and panel boards, of valves and the purpose
they serve are often laughed at when the apparatus is
installed. They help, however, in later locating new
equipment without interference from a long forgotten
sewer or buried pipe line. It is often hours and weeks
before the new man on the job is broken in and can
perform all the duties of his position without question-
ing one of the older men. In the one-man plant many
tedious hours are spent in doping out the various lines of
pipes and their valves. .Many a shutdown is caused by the
lack of some simple little diagram or plan, one that a
man could make in a week or even a day. What the lack
of that plan costs can only be measured by the size of
the plant affected. One man's time for a week may be
forty hours, which is the same as forty men losing one
hour each, or four hundred losing six minutes each. And
six minutes is a very short shutdown.
The lack of plans is rarely the fault of the engineer,
the man in charge of the plant. lie often has all that
he can do to keep it running. Lack of plans is due to
the endeavor to cut down cost, that terribly high first
cost, and often to trying to save time, because it would
take too long to make a drawing to scale. No one seems
to realize that if the scale drawing is nut made in the
office before construction, a full-sized model is built in
the field by cut, try and fit methods. You can get out
of paying for the drawings, but you cannot escape pay-
ing for the unnecessary waste of time caused by the lack
of drawings. True, you may not be able to see the
amount you pay for measures made in the iield, for cut-
ting and fitting, but pay you do, either in money or in
tinic. not only in the first cost, but in upkeep, in making-
repairs.
Lubricating oils are made up from a few easily ob-
tainable base oils or greases. The number of combina-
tions and their proportions are unlimited, but the func-
tion which each ingredient has in the compound appears
t<> lie unknown to the purchasing public. We do not
know exactly what qualities are improved by adding
certain oils, or whether what are popularly known as
adulterants may not lie better than the oils with which
they are mixed. Knowledge of this kind can only be
gained by long and careful test, the expense of which
no one firm should stand.
If a consumer understood why John Smith's No. 3XX
oil is all rigid in the heat of a closed engine room, but
refuses to work after the room is properly ventilated,
he could discuss the oil question more intelligently. As
it is now, oil is bought on representations of the most
general sort and on the trial ami error system. There
is not always a certainty that the same brand of oil doe:
not change while it is being stored by the purchaser.
Who knows what the effect may be of pouring a new bar-
rel of oil into a tank in which there remains a few in-
ches of some old oil, especially when he knows the com-
position of neither? There may be chemical changes
going on even with mineral oils. We can lie confident
that there are changes with time if the oils are of animal
or vegetable origin.
This is a serious problem. It is not so much that the
saving in oil would amount to much. It would not,
but the saving in power is important. Power is mostly
generated to be transformed into heat by way of friction.
In some sections of the country power costs so little
that it has hardly to be considered, but generally, the
engineer is held responsible for the size of the coal bill,
and a man who can cut the consumption is worth more
than one who does not take into consideration all the
possible wastes that may be going on. In some plants
the engineer's responsibility is assumed to end at the
door of his plant, but most owners would welcome his
assistance in reducing costs, even to his suggesting the
oil to be used in the shop or mill. The man whose pay
envelope depends on the low cost of power has a right
to ask that every precaution be taken to see that his
power is intelligently consumed.
Tliis problem is too large and of too universal interest
to expect that any one maker of oil will shoulder the
burden. Some university or other public institution
should assume it. We know much about oils, but our
knowledge is based more on their manufacture and chem-
ical composition than on physical tests, and while the
composition of an oil may be duplicated if known, it is
its physical properties that interest the engineer.
If the present engineers and firemen's license law in
Massachusetts is so woefully wrong and objectionable as
the supporters of the new license bill would have us
believe, it seems strange that it should have taken about
twenty years to find it out.
No matter how good a law may be, it will not find
universal favor. The present law in Massachusetts may
have its little defects. Even so, why should a new bill
be introduced? Are amendments to the present law.
where needed, impossible? Those for and those against
the bill now before the Massachusetts legislature should
know that the function of license laws is to promote
public safety. With this in mind as the fundamental
basis to work on, the present situation ought to be easily
adjusted to the satisfaction of all without destroying a
law which, on the whole, has been long and widely recog-
nized as good.
The letter, "Live Steam vs. Live Men" on page 412, is
printed, not because of its news value, for there is noth-
ing unique about it, but to call attention again to the
dangerous conditions that are permitted to exist and the
necessity for regulations which will prevent them. How
naive the observation that "It (the bill) was supported
b\ a number of engineers and opposed by a number of
manufacturers."
"Aye. there's the rub."
When a daily paper thus throws its influence against
a good measure, it is only natural that its motives should
be questioned.
March 23, 1915 POWER lu
pill uiiiiin illliiiiumiwi limn iiiuiiiiiiniiiiiiii Dill minim s u inn 1 11:1 iiiiiiiihiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiu m«'M« imiiiiiiiimiiiiniimi nun in iiiiiiiiiiihiiii mt
©FF(
0)©mi(sieiniC(
■■ mi mum iiiuiiiiimiiiii niiniuiiiiniiiiiiiiiii mi, ;.::n:: n milium mi i miiiii mi mm, imm asm mi 7=
E. H. Clarke inquires in the issue of Dec. 'fi. 191 I. as
to why his ash ejector will no! work. 1 believe that if be
will plug the end of the 6-in. pipe at the hopper end and
fit a nozzle about % in. diameter, as shown in the illustra-
tion, about three feet from the discharge end, he will get
•. -^''Diom here reduced
'~-wi'fh C.I block
Vacuum Ash Eandleb
over bis trouble, as it is far easier to draw ashes out by
a partial vacuum than to blow them out. At the same
time, I think that less steam will be taken with the suction
outfit, although steam ash ejectors of any type are very
wasteful and should not be used if it is possible to use an
elevator or conveyor.
E. R. Pearce.
Rochdale, England.
Dry batteries are used extensively for operating bells,
tank signals, ignition work on engines, etc., and to many
engineers it is a constant source of worry to keep them
in good condition. The nature of the work demanded of
the batteries often calls tor their use under dam]), hot. drj
01 other unfavorable conditions. The life of the average
dry battery depends more on the conditions in which it
works than on the actual current drawn from it.
The writer has adopted the scheme of protecting batter-
ies from dampness and changes in temperature by cover-
ing them with paraffin, the results being not only increased
life of the battery, but also increased efficiency. All that
i- necessary is to secure a light wooden or even pasteboard
box large enough to hold the required number of cells
and sufficiently tight to hold melted paraffin. The box
should be of such a shape that the batteries may be sel
mi end with about half an inch between cells, and i
i ough so that they may be covered completely, including
binding posts and connections, to a depth of at least half
an inch. The batteries should be connected as usual
and the terminal wires led outside the box where a switch
may be connected if desired- Paraffin is then melted
over a steam hath or in a double boiler and the box filled.
It should be remembered that the paraffin will shrink
in cooling, and for this reason it is necessary to cover
the batteries to a considerable depth to insure their t>
completely covered after cooling.
A set of cells fixed in this manner is waterproof and
proof againsl drying out. They will last at leas! twice
as long as they would if not covered. The writer has rei
ords of sets that have given service in ignition work for
from sixteen to twentj months. For bell work they should
last longer. The cos! of covering the batteries in this
manner is very small. Any suitable-sized box may be
used and the cost of paraffin is not over twenty-five cents
foT a sei of four batteries.
James II. Beattie.
Washington, I ». C. '
'to a locomotive crane which I was operating, the bot-
tom of the truck frame was about 24 in. from the top of
the rail. When the wheels jumped the track the first
thing to strike was the bottom of the axle boxes, and the
weight of the apparatus (about ^0 tons) would fall on
the boxes on one side, meaning that two new boxes (if
all four wheels went off the rails) had to be replaced
before the crane could be opera t.M again, beside letting the
crane sink down to the axles, as the track was laid on
lilled-in ground.
To overcome this difficulty I used two timber- thai
were in the old lumber pile and bolted them t'a<t under
Timbers under Crane to Prevent Damage and
Facilitate Replacing when Derailed
the truck frame, leaving aboui a two-inch clearance be-
tween the bottom of the timber and the top of the rails.
V\ hen the (fane jumped the track again it could onh : ink
two inches and res! on the timbers both hack and front.
Alter that il was "iiK necessarj to swing the loaded
bucket over the rails, raise il to the top of the boom and
the latter till it- weight together with that of the
bucket overbalanced the hack end of the crane. Then
when the wheel- were clear of the rails. \>y setting a jack
or a heavy block or a slant againsl the side of the frame
and raising the boom, the crane would tilt over and the
wheels would fall back on the rails. When one end was
;}■:
P 0 W E E
Vol. 41, Xo. 12
on the rail? the position of the boom was reversed
and the same operation performed on the other end.
Instead of taking four or five hours with five or six
men. as formerly, to get the crane back on the track, it
takes about fifteen minutes with one man besides the op-
erator. Xo heavy lifting, no broken boxes, and little loss
of time.
John II. Honey.
New York City.
Gostt ©IT ©p>©iP©.ftiiE&§g Vsi.cxumEia Aslh^
In the Feb. 9 issue of Powek the Girtanner-Daviess
Co. revives the discussion on the cosl of operating vacuum
ash-handling system-, which was carried on in the issues
of July ;. Sept. 8 and 15, and Oct. 20 of last year.
In this discussion the error is made of assuming that
repairs and depreciation are synonymous. The yearlj
repair cosi of $32 is compared with the 10 per cent, de-
preciation of the system given in my previous discussion.
The fact that the cost of repairs for the first year is but
a nominal sum is no assurance that the equipment will not
go down in the second year of its operation. To get at
the actual rate of depreciation, the two year.- and more
would have to be considered. Any system of accounting
that does not take into consideration all the items com-
prising the cost of ash removal, and that over a number
of years, is going to prove misleading.
While it is true that my experience with the vacuum
system of ash removal was limited to a single installation.
and that of the blower type, it nevertheless gave me a good
impression of the abrading power of swiftly moving ashes
on iron and steel pipe, with its consequent effect on the
cost per toil of ash removal.
From an operating standpoint, success or failure of a
vacuum ash-handling system depends on the amount and
composition id' the ashes. An installation that is consid-
ered a success in the Fast where a low-ash coal i- available
may prove a failure in the West where coal running up-
ward of 20 per cent, ash containing a high proportion of
silica is frequently encountered.
There is no denying that the vacuum system of ash
removal i- a convenience so far as the labor of handling is
concerned, although pulling and breaking clinker into a
6-in. hole is not so convenient as pulling them into a
bucket conveyor or car. ami if the cost can lie kept down
to a reasonable amount, the vacuum system should soon
prove itself the champion in its field. Personally, how-
ever. 1 do lint look for its general adoption.
C. < ». s INDSTBOM.
Kansas City, Mo.
The article in the Feb. J issue emanating from Messrs.
Girtanner-Daviess is interesting reading-. Discussion of
engineering questions, however, in an engineering journal
should 1"' accompanied by stub array of data as will be
really informative to engineers. The information given
in the letter referred to doi • i titute engineering
data, but 1 trust that from the experience of Messrs.
Girtanner-Daviess such data may shortly be forthcoming
SO that engineers may receive some much needed informa-
tion concerning a system or plan which has its undoubted
merit-.
G i oege L. Prentiss,
Xew York. X. T. Parson Mfg. I o.
In reply to the above letters by Mr. Sandstrom and
Mr. Prentiss of the Parson Manufacturing Co., we have
the following to offer: Since our last letter we have had
the opportunity to investigate one of our systems and
find that in the straight pipe, hopper- and all parts
against which the ashes do not directly impinge the
wear is not excessive. Over 18,000 tons of ashes, clinkers
and coke passed through the line in ten months and the
wall of the straight pipe was reduced less than is in.
In the bends of the pipe, which are made in four sections.
the second sei tion, which leads from the straight line into
the curve, is the one that shows the most rapid wear. In
this case over 2500 tons of ashes passed the given point
before replacement was necessary. The cost of replacing
this section is about $10, or 0.4e. per ton of ash handled.
It was not necessary to replace the other sections in this
particular installation, although 8000 tons has been the
limit in other installations.
According to the above data it is estimated that the
straight pipe is good for the conveyance of at least 200,000
tons of ashes, and on this basis the depreciation would be
about 10 per cent, on the line. This, of course, represents
maximum operation, and where the service is less the life
of the straight pipe, made from specially hard chilled
ron 1 in. thick, would lie indefinite. In other words,
the installation on a ?- or 8-ton-per-day performance.
would last longer than the boilers or other equipment
which it serves.
Some of the points mentioned by the parties discussing
this subject are based on ordinary pipe of the usual thick-
ness which costs more per pound and wears out more
quickly, requires additional labor, costs more for upkeep
and depreciates more rapidly.
If there is any further information desired, or any
direct inquiry made, we shall be glad to give specific data
on installations in operation for IS months.
Pi. H. Millei;.
St. Louis, Mo. Girtanner-Daviess.
ILIv© Stegctsm veips^ss ILi^© Meim
Here is a copy of a clipping taken from our local paper
four years back:
A hearing was held Friday before the committee on labor
on the bill which provides for the licensing of steam engi-
neers and the appointment of a chief engineer with a brood
of assistants — all drawing live steam from the state treasury.
It was supported by a number of engineers and opposed by
a number of manufacturers. The committee is expected to
blow the whistle for the recall of this bill.
And here is a bit of personal experience in our own city
of wry recent date by a local engineer:
With a friend I visited a neighboring power plant in
which a boiler fifteen or twenty years old was doing duty.
The first thing that 1 noticed was a lever safety valve
supporting at the outer end of the lever, not only the
weight which went with it. but a six-quart pail containing
a varied assortment of bolt-, obi iron. etc. For the un-
informed I will say that this would hold the steam in
the boiler to a pressure perhaps twice that for which it
was built, or even more, when from its age the pressure
should probably not be allowed to exceed two-thirds that
for which it was originally designed. Being curious. I
asked the engineer ( ?) what steam pressure he carried,
lb- took me to the steam gage and rapped the pipe a
number of times: the pointer each time would find a
new position, showing that it was out of order. Also.
March 23, 1915
POWER
413
there was a gage-glass and only two gage-cocks, but as
there was a lively fire under the boiler, I did not care
to ascertain if they were working properly, so took a
hurried departure, inviting my friend to come along and
fearing for the safety of the 25 men working within one
hundred feet of this "live steam" which threatened then-
lives through the gross carelessness or ignorance of the
man in charge, the owner or both.
Would it not be well to have a boiler-inspection and
engineer's license law on our statute books before we
attend the funeral of a friend, or perhaps a son or
brother, killed by a boiler or engine accident, even if
those who enforce it do draw "live steam"' from the state
treasury?
I will vouch for the above facts, substantially as pre-
sented.
A Connecticut Engineer.
Bristol, Conn.
Tlhe EMesel Ermgpiim© DeifeE&dledl
In the article on "Oil Engine Tendencies'' in the Feb.
9 issue we note among the objections which can be raised
against the Diesel engine that "it is complicated in de-
sign, necessitating strict attention to the minutest details
and requires a very high grade of workmanship." We
are led to wonder why, and since when, have sound work-
manship and conscientious care and attention become ob-
jectionable. Surely, it is one of the great merits of the
Diesel engine that those who build it thoughtfully bring
to bear upon its production the best of brains and labor.
No complication of design requires this ; the engine is
essentially simple. This accuracy of construction and
honesty of material and workmanship are demanded by
the higher pressures in this class of engine.
By years of experience the reputable and more prac-
ticed Diesel-engine builders in Europe have eliminated
the troubles first encountered with these higher pres-
sures. The correct practices in four-stroke-cycle design
have long since been firmly established, and it is of this
knowledge that we availed ourselves when we became the
sole licensees of the Swedish Diesel Engine Co., a firm
with 17 years' specialized experience.
It is correct to state that close adjustment must be
maintained at all times, but Mr. Ward goes astray when
he adds that skilled attendance with corresponding high
cost is essential. The adjustments are extremely infre-
quent, for the wear upon these engines is so slow that it
does not become sufficiently pronounced to need attention
in less than 10,000 operating hours, and frequently more.
The only requirement of the attendance is that it shall
be intelligent. The distinction between the terms
"skilled" and "intelligent" is important and must be
observed. The one implies high wages and difficulties
of supply ; the other brings the attendance to an ordinary
level. With the simple instructions we are issuing for
the care and maintenance of our Diesel-type engines any
engineer of average clearheadedness will be able to operate
them with a maximum of satisfaction, obtaining prolonged
and economical service.
The estimate that between 400,000 and 500,000 hp. in
the aggregate is supplied by Diesel engines in Europe is
far from the mark. The writer made a close computa-
tion about 12 months ago and arrived at the total of
1,800,000 hp., but by this date the figure will have been
exceeded. The firm which made of Diesel's project a
practicable engine and translated his ideas into a sound
commercial prime mover has itself sold over 400,000 hp.,
or as much as Mr. Ward estimated for the lower limit
of the total European output.
R. W. Crowly,
Mcintosh & Seymour Corp.
Auburn, N. Y.
C ©mm Ibmsfta© ira
I have carefully studied the Bureau of Mines. Technical
Paper No. 63, on "Factors Governing the Combustion of
Coal in Boiler Furnaces," and find it interesting. The
object and scope of the investigation promise informa-
tion that engineers are eager to have. It is true that there
is a lack of knowledge of the underlying principles of
correct furnace design, but perhaps when this investiga-
tion is completed there will be available information really
useful in practice.
Recorded results show that practically the same amount
of combustion space is required for burning both 28.4 and
44.3 lb. of coal per square foot of grate per hour. This is
the case for all percentages of excess air. This is more
noticeable when presented graphically as shown herewith.
It requires about 40 per cent, more combustion space to
produce 0.2 per cent, or less combustible in the gases, at a
combustion rate of 21 lb. per square foot than at 28 lb.;
therefore, it does not seem reasonable that it would re-
quire the same space for a rating of 44 lb. as 28 lb. Also,
above 44 lb., as is shown by the chart, the space required
increases.
This paper shows that a long and spacious combustion
space is necessary to allow for complete combustion of
Excess Air Per Cert
50
30
S 5 20
Cubic feet of Combustion Space Necessary 0.2 Per Cerrtor Less
Combustible feted
Curves from Bureau of Mixes Paper
the gases and increased efficiency. From t lie bulletin's il-
lustration, Fig. 10. on the variations in furnace condi-
tions during test No. 121, it will be noted that the aver-
age temperature at section G was about 300 deg. F. less
than at section .1. a distance of about 29 ft. Upon re-
ferring to the data on this test it will be found that the
rating was exceptionally high, (>1 lb. per square foot. Also
one figures that the loss caused by the drop in tempera-
ture amounts to more than the loss that would result
from incomplete combustion.
Furthermore, this loss due to a restricted combustion
space occurs for short periods during peaks and would not
balance the floor space and investment and maintenance-
cost of space necessary for complete combustion.
' 1/
1
j
*j
,J/
§
/
26-
•
/
-
■
0
E
)
<b
)
)
8
)
'
0
II
0
1
0
1
)
12
0
HC
414
P 0 W E B
Vol. 11. No. 12
Information on the amount of combustion space needed
for certain grades of coals burned at certain ratings is
necessary if we are to calculate the investment and main-
tenance costs.
Meridian. Miss. Charles M. Rogers.
The letter by C. L. Juno regarding broken capscrews,
on page S91 in the issue of Dec. 22, reminds me of a some-
what similar job.
One day it was noticed that one ammonia compressor
fastened to its pedestal base with twelve lYpin. capscrews
was moving a little and that three of the capscrews were
broken and most of the others loose. The machine was
Keys to Take Strain from Capscrews
shut down, the broken pieces drilled out. as we had plenty
of room and good tools, and new capscrews put in.
We soon found two more broken ones, and as time went
on it was a common thing to find broken or loose cap-
screws, and to hold those two compressors steady became
a troublesome problem, although we made a new set of
capscrews with bodies a snug fit in the holes through the
pedestal. Finally, slots A were cut 1 in. deep and '■) in.
wide at both ends on both sides, making lx3-in. slots, or
keyways, one-half in the pedestal and the other half in
the cylinder flange, and extending clear across.
Tight-fitting keys were made and driven into these slots
after the capscrews had all been pulled up as tight as
possible. This cured the trouble, as the strain was on the
wedges instead of on the capscrews.
Chicago. 111. A. G. Solomok.
Mr. WnEM^fflms" IR,@jj©2in\dleir
In the .Mar. 2 issue a reference is made to the Hall of
Records' test, under the title "Some Dates to Remember.'"
which suggests, at least indirectly, that the New York
Edison Co. is endeavoring to withhold the results of the
test from publication. On the contrary, we have repeat-
edly urged that the report be completed and signed at
the earliest practicable moment. The test — probably the
most complete ever made of a private plant — was con-
ducted under the supervision of a committee consisting of
some of our most eminent practical and theoretical engi-
neers, as representatives of the City, the Bureau of Muni-
cipal Research and ourselves.
Numerically, the representatives of the Edison com-
pany on the committee are in a minority. Quite apart
fiom this, however, the character of those who have been
in charge of the proceedings should preclude any sug-
gestion of influence, undue or otherwise, concerning their
final action, whether in favor of or against the operation
of the private plant or the service of this company. Af-
ter the completion of the test, some time has been re-
quired for analysis ami study before the preparation of the
report. All this we understand is now practically com-
plete, and it is expected that the report will soon be ready
for publication.
Knowing that you would not even unwittingly do in-
justice either to the gentlemen who have given so much
time to this important question or to this company, we
feel that you will take such fair means as may be neces-
sary to avoid misunderstanding, through inference or
otherwise, from the editorial in question.
Arthur Williams,
General Inspector, Xew York Edison Co.
Yew York City.
| We are glad to learn that Mr. Williams is as anxious
as ourselves to see the report on the Hall of Records' fcesl
made public. The impression is current that the represen-
tatives of and sympathizers with the Edison company on
the committee, through zealous efforts to serve their
client-' interests, were largely responsible for the delay. —
Editor.]
WW as. Radiattoa- Wotmld Hot
In part of a direct-heating equipment, a two-pipe radia-
tor connected to a vacuum return system failed to heat.
There was about one pound pressure on the steam side
and about three inches of vacuum on the return line.
At first the case seemed puzzling, especially as the ad-
mission valve and the thermostatic return-end trap proved
to be unobstructed and all the other radiators in the
building were heating nicely. An examination of the
lines leading to this particular unit showed that it wa.< the
end one of the series. In other words, it was fed bv the
\\)\\\u\y
Floor
.. . - -
J- J- J
rfr)
t
Trap
o
■Trap which was I
Stopped
Vacuum Line
&
Pluc
Trap- Preventing Circulation of Radiator
extreme end o( the steam line and tapped by the extreme
end of the vacuum or return line.
As shown in the sketch, a trap had been installed in a
jumper across the space beneath the floor where the
radiator was, the supposition being that the arrangement
would keep this extreme end dry. However, when the
cap cover was removed from the trap an old lead pencil
was found firmly wedged under the thermostat. Thi<.
of course, propped it up and completely destroyed its
function. A short-circuit was thus formed, shunting the
heating unit entirely. When the obstruction was removed,
the trap closed and the radiator promptly warmed up.
Philadelphia, Perm. Edward T. Binns.
March 23, 1915
P 0 W E It
1 1 5
'Jli&ggE'&ffimS
The ammonia compressor was a vertical, two-cylinder,
single-acting machine with two cranks at 90 deg., driven
by a water turbine. Only one ammonia indicator
Fig.
Correct Diagram;-
(Thompson type) was available, so pipes were led from
the two cylinders to a three-way cock between the two
cylinders. As the two cranks were at an angle other than
180 deg. to each other, it was necessary to attach a re-
ducing rig to each erosshead. The two pantographs used,
being direct-reducing rigs, caused both diagrams to fail
Diagrams Incorrectly Taken
at the left end of the card, and made it desirable, if not
necessary, to take them from the two cylinders on separate
cards. Normal diagrams arc shown in Pigs. 1 and 2.
During the noon hour while I was away for lunch,
the man operating the indicator did some investigating
and devised a short cut to suit himself. Finding by
experiment that one reducing rig, acting indirectly with
respect to the one for the other cylinder, would put the
two diagrams on opposite ends of the same card, and for-
getting that the function of a reducing rig is to move the
indicator 'drum in time with the piston to which it is
attached, he discarded one pantograph and got the
diagrams. Pig, 3.
When the pencil point wore down and the diagrams
became faint, he unscrewed the handle from the pencil
mechanism and jammed the point so hard against the
drum that the pencil arm bent sufficiently to catch under
the end of the front pedestal shaft and cut otf the tups
of the diagrams as shown in Pig. 1. No less than half
Top of Diagrams Missing
a dozen such diagrams were taken and delivered to the
man operating the planimeter, who integrated the areas
and entered them on the log sheet without question.
F. V. Larkin.
So. Bethlehem, Perm.
The issue of Nov. 24, page 746, describes a device used
to assist a flyball governor to maintain the speed of an
engine within 1 per cent, from no load to a 25 per cent,
overload. It is stated that one of these compensators has
been in use for five years, giving good results, and that it
should prove of value in rolling mills, sawmills, etc.,
where the variation in the load is great.
Judging from the illustration and the description, it
is my opinion that it would be useless, if not a detriment,
even on engines operating with a comparatively steady
load.
Suppose the load should suddenly become greater; the
reduction in the speed of the engine would cause the gov-
ernor to drop for a longer cutoff, thus throwing the com-
pensator out of level. This in turn would cause the mer-
cury to shift to the lower end of the tube and by its weight
hasten the downward movement of the governor. So far
its work is admirable, but what would take place when
the extra load goes off?
The governor tends to rise for a shorter cutoff and,
in addition to lifting itself, is burdened with the extra
weight of the mercury in the lower end of the compensa-
tor. This will require a higher speed of the governor and
of the engine than if the device were not used.
When the extra load came on and the mercury took
the lower end of the tube, the governor would not allow
the engine to drop to as low a speed as if the mercury
tube were not used. On the other hand, the governor
would require a higher speed in order to raise the addi-
tional weight to a point where the tube would be level.
or inclined the opposite way if necessary. What is gained
one way is counteracted in the other, and should the fluc-
tuations in load be great and frequent, the device might
prove to be a detriment.
416
POWER
Vol. 41, No. 12
Another statement says the division walls prevent any
sudden shifting of the mercury. It seems that to hold
the speed within narrow limits the shifting should be
ii. and if the device provided for this in both direc-
tions, without the necessity of lifting it at the expense of
the speed of the governor after it is once out of level, the
results would approach the ideal.
I am inclined to think the description does not cover
the ground : that something is omitted that would explain
the apparent defect, because if it has been used for five
years with good results, we have no right to dispute the
statement.
The article also says "it has the same effect as auto-
matically increasing or decreasing the weight of the
balls," etc. This is true, but which way will the change
in speed of the engine be for a given change in the gov-
ernor balls? By test, the engine was found to run slower
for an increase in the weight of the governor balls and
vice versa, the dead weight or counterpoise weight re-
maining unchanged. Therefore, when the tube shifts for
a longer cutoff it produces the same effect as if the ball-
were made lighter, and an opposite shift produces the
same effect as if they were heavier.
Joseph Stewart.
Hamilton. Ohio.
Among other things bought in a job lot were about four
dozen gage-glasses of good quality but too short for any
of our regular connections. I hit upon the following way
of making use of them:
The upper packing nut was replaced by a reducing
coupling, threaded to suit, into which a short brass pipe
was screwed. The lower end of this pipe was threaded
to receive a pipe cap, which had been bored out a neat
fit over the gage-glass. This formed a good stuffing-box
for lower pressure. It happened in this case that the bore
of the pipe was just right for the glass, otherwise a washer
at the end of the pipe would have been necessary, to form
the bottom of the stuffing-box.
Short glasses may be utilized on low-pressure work
by using a piece of hose to join the ends wherever they
may come, thus forming a flexible joint. Long receiver-
tank glasses will often last longer when in two parts than
in one.
Arthur D. Palmer.
Dorchester. Mass.
Wlrn^ thi® ©M Eiragaiaeeir Lo§4
Mas Jolb
Coming back to Boston after live years in South Amer-
ica, the first thing I did was to visit my old friend. Bill.
the engineer. Long before I can remember — in fact, be-
fore I was born — he was there at the plant. I had thought
many times of him, his big, smiling face, as he sat in a
larjie wooden armchair in the engine-room doorway smok-
ing his old pipe; and he always had a friendly word for
us kids.
Arriving at the engine room, I was surprised not to see
Bill in the doorway : even the chair was missing. The old
engine had been displaced by a turbine, and at the desk
was a strangeT reading a blueprint.
I asked for Old Bill (I never did know his last name)
and was told I would find him in the pipe shop. It made
me feel good to hear that he was still at the plant and it
did not take me long to cross the yard. The first man I
met was Bill, but what a different man !
"Are you Bill, the engineer?"
"Yes — I used to be."
"Used to be : what's the trouble : why are you not now?"
"Well," said he. ""the 'Old Man' died and his son took
charge a couple of years ago, and that fixed me all right.
He put in new machinery and then he wanted me to make
tests on the boilers and turbine, and to send a monthly
report of everything to the office. I didn't know how to
do those things. They got a new engineer, but kept me
around the plant, and there you are. Many a time I
wish I was dead, as this come-down is awful."
The thought came to me right there, how many engi-
neers of the old school will go the same way, because they
don't know !
H. C. Harbis.
Boston. Mass.
■M
ComrosSomi of Hs*@ira. aiadl S&eel
Pipe
There are no reliable data as to the relative ability of
iron and steel to resist corrosion. Furthermore, it is a
difficult matter to identify the two materials without the
acid-etching test. Some time ago, an engineer with many
years" experience in the installation of steam and hot-
water heating plants remarked that he could tell whether
the pipe was iron or steel by the way a die cut. Some
short pieces of pipe were submitted to him to separate
the iron from the steel. His attempt met with such indif-
ferent success, as shown by the acid test, that he re-
marked : "There's one thing certain, I don't know iron
from steel."
Besides threading easier, he believed that iron pipe re-
sisted corrosion better than steel. Both these beliefs were
shaken when he learned that he coitld not distinguish be-
tween the two.
The popular notion is that if it corrodes easily, it is
steel : if it offers considerable resistance to corrosion, it is
iron.
Some years ago the purchasing agent for a packing
house ordered from the mill a number of bars of strictly
wrought iron. There was no wrought iron in the plant.
everything being soft and medium steel. The manager
had the order filled from the steel stork, savins : "If they
discover the difference we'll refund their money and give
them the steel." The manager had some misgivings until
another order was received from the same asent for more
iron. This is an incident of which I have personal knowl-
edge.
Later. T was employed in two different packing ho
and was amused by the stories of the wonderful durabil-
ity >'i wrought iron and the utter worthlessness of steel
under packing-house conditions. There, is much differ-
ence of opinion among those who ought to know: one
makes a test that proves conclusively that steel corrodes
faster than iron : then another makes a test that proves
the contrary. The only vital difference I have been able
to find i- in the price, steel being cheaper.
C. 0. Saxpstiiom-
Kansas City, Mo.
March 23, 1915 POWER 417
piniiiiiiiiiiiiiiiii inn nun imiinmiiiiiiii minim i iiiiimmiiiniiiimii iiiiiiiniiiimn i iiiniii m mi iiimiiiiiinii m n minium m inn iiiinmimi mm iiiiiiiiiiiiiiiiiiing
.imcjvULiimK
i3meFg\Il IimtLeiresft
i
Conversion of Heat into Work during; Expansion — Why
should steam lose any of its heat when expanding and doing
work, if it loses none while expanding and doing no work?
W. R. W.
Heat and energy are mutually interchangeable, and when
work is done in the process of- expansion it is performed not
by loss but by conversion of some of the heat of the steam
into energy, each heat unit thus transformed being con-
verted into 778 foot-pounds of energy, and as a consequence
of the transformation, the remaining heat in the steam must
be less than the heat which it contained before doing the
work.
Brake Power of Engine — What brake horsepower is de-
veloped by an engine when the length of brake arm is 60 in.,
tare weight of brake 20 lb., total pressure of brake arm 156
lb., and brake wheel makes 200 r.p.m.?
T. R.
The brake horsepower is given by the formula
Length of brake arm in feet X 2 it X net weight or pressure lb. X
hence there would be
60
— X 2 X 3.1416 X (156 — 20) X 200
= 25. S9 b.hp.
Metering; Fuel <;as at Different Pressures — What would
be the relative weight of equal volumes of fuel gas measured
by a volumetric meter at S oz. and at 12 oz. pressure?
R. V. S.
For the same temperature the density would be directly
as the absolute pressure. Taking the pressure of the at-
mosphere at 14.7 lb., or 235.2 oz., per sq.in., and assuming
the gas pressures are quoted in ounces per squa"re inch in
excess of atmospheric pressure, then for 8 oz. pressure the
absolute pressure would be
235.2 + S = 243.2 oz.
and for 12 oz. pressure it would be
235.2 + 12 = 247.2 oz. per sq.in.,
hence, a given volume metered at a pressure of 12 oz. would be
247.2
as much or about 1.6 per cent, more than when metered
243.2
at a pressure of S oz. above atmospheric pressure.
\Veig;ht of Plunger When Submerged — When submerged
in water, what would be the weight of a hollow bronze pump
plunger Is in. in diameter by 70 in. long, having ends 4 in.
thick and sides % in. thick?
S. C.
The weight immersed will be the difference between the
weight of the plunger in air and the weight of the volume
of water displaced. The volume displaced would be (18 X 18
X 0.7854) X 70 = 17,812.9 cu.in.. and taking the weight of
water as 0.0361 lb. per cu.in., the weight of water displaced
would I.- 17,812.9 X 0.0361 = 643.046 lb. The hollow part of
the plunger being a cylinder li''L. in. in diameter by 62 in.
long, the net volume of metal would be
17, si 2.9 — [(16% >' 16 ^ X 0.7854) X 62] = 4555.7 cu.in.
and taking the weight of bronze as 0.3195 lb. per cu.in., the
weight of the plunger in air would be
4555.7 X 0.3195 = 1455.55 lb.
so that the weight of the plunger submerged would be
1455.55 — 643.046 = 812.51 lb.
of Alternator
the field coils of an
Effect of Short-Clrcuit in Field Coils
would be the effect of a short-circuit ii
alternator?
\\ . C. R.
It would depend somewhat upon the windings and the
way they are connected. If the machine is either one-, two-
or three-phase there would be a decrease in the voltage. If
the windings of the three-phase machine are delta connected
there will be local current set up in them which may be so
serious as to cause overloading that would affect the lights
connected to the machine. One ground in the field, with the
rest of the system insulated, would have no effect, but if
combined with a ground on some other part of the circuit it
would cut out one or more of the field coils.
Origrin of "Horsepower" — What is the origin of the term
horsepower?
R. C.
Before the introduction of steam engines, the work of
horses was employed for driving mills, pumps and other
machinery, and the power required for their operation was
commonly expressed in the number of horses required, and
numerous estimates were used for the average "working
power of a horse. For rating the power of their steam
engines Boulton and Watt adopted an estimate based upon
their observations of the power of strong draft horses em-
ployed S hr. per day at London breweries. They found that
a horse was able to go at the rate of 2V2 miles per hour and
at the same time raise a weight of 150 lb. by means of a
rope led over a pulley, and the rate of work performed, viz.,
2% X 5280 ft. X 150 1b.
= 33,000 ft. -lb. per min.
60
thus established as a horsepower, has been continued as the
standard among English-speaking peoples.
Size of Common Exhaust Pipe — What is the rule for find-
ing the diameter of a common exhaust pipe for engines hav-
ing, respectively, 4-in., 6-in. and 7-in. exhaust connections
without materially increasing the back pressure?
P. E. M.
The relative flow of steam of the same density in different
pipes varies as
1 d»
\ d + 3 6
in which d = diameter in inches. Assuming that the exhaust
is at the same pressure in each pipe at the point where they
are joined together, then without materially altering the
back pressure from what it would be from an equal extension
of each exhaust pipe, the diameter of the common exhaust
pipe would be the value of d in the equation
\d-
ii"
\ 4 + : 6 \6 + 3.6 \ 7 + 3.6
198.27
By assigning different values to d the nearest even pipe
size required is found to be between 9 and 10 in. and there-
fore a common exhaust pipe of 10 in. diameter should be
employed.
Capacity of Closed Water Heater — What quantity of
\vat»r can be heated from 60 deg. F. to ISO deg. F. by a
sufficient supply of exhaust steam ai 4-lb. gage pressure in
a closed heater containing 21 three-inch iron U-tubes hav-
ing an average length of 16 ft.?
P. B. B.
Standard 3-in. iron lap-welded boiler tubes have an in-
ternal dian
amount to
eter of
in., and the heating surface would
12
X 3.1416 X 16 X 21 = 244.
sq.ft.
Taking the average temperature of the steam as 21S deg. F.,
and average temperature of the water as 120 deg. F., the
perature difference would be 9S deg. F., for which
there would be a condensation of about 18 11.. of steam per
square foot of pipe surface per hour, and as each pound of
steam would libi rati ihout 966 B.t.u., the total heat trans-
mitted to the water would amount to
966X18X244.72 = 4,255,191 B.t.u. per hr.
and as each pound of water raised from 60 to ISO deg. F.
would require
180 — 60 = 120 B.t.u.
ould be
4,255,191 4- 120 = 35,459.9 lb.
or about
35,456 -=- 8.33 = 4256 gal. of water heated per hour.
[Correspondents sending us inquiries should sign their
communications with full nami post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
418
POWEB
Vol. 41, No. 12
^FMliE Ol
^uisetlts
Several hundred engineers and firemen attended a hearing
at Boston, Mass., on Mar. 10, given by the legislative commit-
tee on mercantile affairs upon House Bill 1111, a measure
introduced by various interests to render the licensing of
engineers and firemen easier than under the present law.
The hearing was one of the most hotly contested of the
session, operating engineers from all parts of the state
registering their opposition to the proposed changes in the
law.
ABSTRACT OF THE BILL,
The bill provides that to be eligible to apply for examina-
tion for a fireman's license, a person must have been employed
as a fireman for not less than one year. The examination
must be of a practical character, to ascertain whether the
applicant has thorough knowledge of the functions of a steam
boiler and its appurtenances, of the proper methods of opera-
tion and cleaning, how to proceed in case of accident, low
water, or in the event of signs of distress; of packing hand-
holes, manholes, valve stems and pipe flanges, and of the
proper condition and management of boilers and their acces-
sories, including pumps and other feeding devices.
Steam engineers' licenses are required by the bill in the
operation of all engines of 25 hp. and over, with the usual
exceptions of railroad locomotives, agricultural engines, etc.,
instead of the 9-hp. limitation of the present law. Thirty
days are allowed for evidence of a second violation, in place
of "one week as at present. To be eligible for a first-class
engineer's license, a person must have held a second-class
license or must have been in charge of an engine or engines
of over 150-hp. rating each, for a period of not less than two
years, or must have served as a steam-engine erector, me-
chanical engineer or master mechanic of a plant having an
engine or engines of over 150 hp. rating each, for not less
than three years. The examination for a first-class engineer's
license is required to be of a practical character to show
whether the applicant has thorough knowledge of the con-
struction, proper care and safe operation of steam engines
and their appurtenances.
A second-class engineer's license entitles a steam engineer
to have charge of any steam engine or engines not exceeding
150 hp. each, und-^r charge of a first-class licensed engineer.
To be eligible for a second-class license, a person must have
operated a steam engine or engines for not less than one
year, or must have served as a steam-engine erector, mechan-
ical engineer or as master mechanic for not less than two
years. The examination covers about the same range of
topics as for a first-class license with the exception that
knowledge of engine construction is not required. A person
seeking a third-class engineer's license may take an examina-
tion upon presentation of a request signed by the engine
owner or user, such license entitling the holder to operate a
particular engine or engines without limit as to size. In
other particulars the bill generally follows the existing law.
It provides for the retention of all existing licenses and for
their exchange, when desired, for licenses under the new
law, according to a tabulation which need not be reproduced
at this time.
Edward P. Butts, chief engineer of the American Writing
Paper Co., Holyoke, the original petitioner for the bill, was
the first speaker. He pointed out that under the present law
engines and boilers are held to be equal as hazards. He
contended that the boiler presents the greater risk, indicated
by the fact that most boilers are insured against accident,
but comparatively few engines. Constant attendance, he
held, is essential in the boiler room, but not at the engine.
The present law is complex, in his opinion, and the petitioners
object strenuously to the lack of uniformity in examinations
for licenses. The character of the examinations depends too
much upon the discretion of local inspectors and is fre-
quently too technical. Mr. Butts contended that firemen
should not be examined on points in boiler construction nor
engineers on details of engine design, claiming that the
examiners should ascertain merely whether a man is com-
petent to run the equipment without any extended theoretical
knowledge of it. He held it to be unfair to owners of
plants using water power a large part of the year to require
them to hire skilled engineers for twelve months, when
steam-auxiliary service may be needed only for two or three.
Another point which the bill is designed to care for is the
elimination of the first-class engineer as a necessity to the
operation of portable engines. Connecticut has no such license
law as Massachusetts, and the speaker contended that the
operation of engines and boilers is just as safe there as in
the Bay State.
William McCorkindale, Holyoke, representing the Parsons
Paper Co., attacked the questions given candidates for a
second-class engineer's license on the ground that they are
too technical. In a specific instance one candidate failed
through inability to tell the examiners the physical proper-
ties of steam, the ratio of expansion in turbine blades, and
why a fusible plug melts when low water occurs in a boiler.
C. A. Crocker, Chemical Paper Manufacturing Co., Holyoke,
said that too much discretion in the enforcement of the
existing law is placed upon the inspectors in local districts.
He felt that the bill provides as well for safety as the existing,
law and pointed out that a man to have charge of a large
plant should not necessarily have a fireman's license.
James O'Brien, Lee Marble Works, Lee, said that the pres-
ent law requires his concern to put a steam engineer on each
channeling machine because the engine is rated at 12 hp.
This, he said, has been a great embarrassment, because
specially trained men are required to operate channelers in
quarries. Under the present law he could not even utilize
the services of the manufacturer's erectors in the operation
of channelers. He cited the case of an experienced erector
employed by the Sullivan Machinery Co., Claremont, N. II.,
to instruct Russians and other purchasers in the use of chan-
nelers made by this company. This erector could not obtain
a Massachusetts license because he was unable to answer
purely technical questions about steam engineering. The
present law limits engines to 9 hp. without a licensed engi-
neer, and the speaker urged that a 25-hp. limit be adopted.
He said that at present a man with a third-class license
could run a single engine not exceeding 50 hp. in rating,
but if such a machine broke down and the employer wanted
to run two 10-hp. engines or two 25-hp. engines by the same
man, there would be a violation of the statute.
Mr. O'Brien said that these restrictions made it much
harder for Massachusetts companies to compete with concerns
in other states and led indirectly to the employment of fewer
engineers than would be the case under the proposed law.
Thus, in Georgia, no license is required to operate quarry
machines by steam, and there is no law in Vermont which
licenses engineers and firemen. He thought that in these
industrial plants special licenses should be given in many
cases. He said that in the paper industry conditions are
fully as troublesome through the present law, which may
force electrification of many mills if operators of paper
machines are not allowed to start and stop their steam-driven
apparatus without the immediate supervision of licensed
engineers. The ruling of an inspector now on duty in the
Connecticut Valley, that a certain mill should employ a
steam engineer for each paper machine, threatens to increase
the payroll by $300 per week.
George P. Gilmore, an engineer with the American Printing
Co., Fall River, brought out the point that the number of
engineers' licenses issued has fallen from 97 first-class in
1911 to 62 in 1913, and from 1S6 second-class to 115. He
stated that there are 1726 first-class licenses outstanding in
Massachusetts today and 1796 second-class. At the present
rate of increase it will take twenty-eight years to replace
the present number of first-class engineers and eighteen
years to replace the second-class men. He objected vigor-
ously to the absence of any appeal from the decisions of
the examining board.
Capt. White, Lowell Paper Tube Corporation, Lowell,
contended that the law should specifically limit the powers
and scope of examiners. Requirements for licenses should
be definite, as in the Navy, where the speaker had spent
36 years. The naval examination of firemen is always oral
and purely practical. Capt. White bewailed the fact that
a man can fire a torpedo-boat boiler and still be unable to
get a fireman's license for a Massachusetts stationary plant.
Frank Dresser, American Steel & Wire Co., Worcester,
pointed out that in his opinion the bill does not impair safety.
The United States Ste^l Corporation does not consider the
holder of an engineer's or fireman's license as necessarily
qualified for plant operation. The company desires to know
what sort of an examination was given and does not favcr
the present non-standardized methods. Knowledge of stresses
in steel is unessential to the proper handling of power plants,
the speaker contended. The company at present employs
125 engineers and firemen at Worcester, and in normal busi-
ness periods 200.
Frederick M. Ives, for the Massachusetts Electric Lighting
Association, Boston, also favored the bill.
Clifford Anderson, for the Norton Co., Worcester, said
that one of the best engineers in the state operates a 250-hp.
steam engine, a 500-hp. gas engine, and a 1000-hp. steam tur-
bine in the company's plant, on a special license. This
engineer, who has maintained the engine service for twelve
years without a minute's loss of time, who has run the gas
engine with a loss of only 0.5 per cent, in working time, and
who has run the turbine unit one year and three months with-
out a moment's stoppage due to machinery trouble, cannot
get a first-class license in any other plant because of his
March 23, 1915
P 0 \Y E K
419
inability to answer highly technical questions put by the
•examiners. The speaker attacked the present law on the
grounds that it keeps out competent men, and he criticized
examinations upon theoretical points.
Samuel M. Green, Springfield, Mass., consulting engineer,
appeared on behalf of the Springfield Board of Trade and a
large number of paper and other manufacturers in the
Connecticut Valley. He said that his clients do not consider
that the Massachusetts license is an index of a man's ability
to operate a given plant and that often the examinations
■contain foolish questions. The bill stipulates that the exam-
ination of both engineers and firemen shall be of a distinctly
practical nature. Mr. Green stated that the American Society
of Mechanical Engineers has been considering a standard
set of regulations governing the licensing of engineers and
firemen, but that it had withdrawn the plan of closely fol-
lowing the Massachusetts law in this respect. The speaker
■contended that there are numerous inconsistencies in the
present law which work hardships to the plant owner. Thus,
the law now holds that an engine of over 50 hp. must be
-operated by a man with a second-class license. By reducing
the speed of a 60-hp. engine on a paper machine 15 per cent.,
for example, its rating may be cut down so that it can
be run by a third-class engineer. In one plant the owner
employed a technical graduate as plant engineer. He was
refused a license because he had not fired a boiler for a year.
At the Hotel Kimball, Springfield, an engineer from New
York State was refused opportunity to take the Massachusetts
examination because he had not resided in the latter state
for from four to six weeks. Mr. Green contended that firing
is not an essential preliminary to an engineer's job.
OPPOSITION TO THE BILL
A. M. Huddell, Boston, who said he represented 13,000 men
affiliated with the Massachusetts branch of the International
Union of Steam and Operating Engineers, maintained that
the bill jeopardizes public safety and contended that while
uniform examinations and uniform enforcement of the present
law are desirable, the present bill should not be substituted.
If the bill passes, third-class plants will be legislated out of
existence. Mr. Huddell attacked the provision of the bill
allowing thirty days to pass instead of the present seven
.after an inspector has found a plant improperly manned,
before a violation can be charged. He said that an inspector
ought to be permitted to enter a plant at any hour rather
than at a so called "reasonable" hour, as stated in the bill.
Manufacturers can get all the relief they desire from the
present law if it is properly enforced. The speaker advocated
the establishment of a mechanical department separate from
the District Police, who now enforce the boiler and engine
laws of the state.
D. G. Kimball, Roxbury, Mass., representing the National
Association of Stationary Engineers, said that the entire
plant should be in charge of the chief engineer, whereas
the bill tends to divide the responsibility of the plant between
the engineer and the fireman. He protested vigorously
against lowering the standard of the examination and set
forth the importance of an engineer's acquiring a broad
knowledge of his profession, including both theory and prac-
tice. "Our aim," said Mr. Kimball, "is to enable an engineer
to rise higher in his work. He should study and keep up
with his trade, and we favor the present law because it
tends to that end."
C. C. Harris, Springfield, Mass., president of the Brother-
hood of Power Workers, held that it is unsafe to place a man
in charge of a steam plant unless he knows something of the
construction of engines. He cited instances of accidents to
paper-mill steam-driven machinery through the mishandling
of the equipment by unlicensed men. Failure to drain the
pipes in one case cost two lives, through an explosion which
followed suddenly turning on steam.
Thomas Hawley, head of the Hawley School of Engineer-
ing, Boston, was a vigorous opponent of the bill. Mr.
Hawley said that the present law had served well for over
twenty years; that it had led to great improvements in the
handling of plants and had enormously diminished the num-
ber of explosions, besides raising the caliber of engineers
and firemen. The proposed measure does not provide any
really easier examinations and is a step in the wrong
direction. The speaker ridiculed the inconsistency of the
bill in requiring a man to work a year as a fireman before
getting a fireman's license. The present law permits a man
to start in as a helper. A way must be provided by which
a man can enter the business.
The speaker pointed out that the present examinations
•are practical. Thousands of firemen have been examined
■on the operation of boilers and not on their responsible care.
Under the terms of the bill a man practically unqualified
■could be put in control of equipment on which he has
not been examined. The examinations are not unduly
difficult. The speaker favored requiring that the applicant
be able to understand the English language before a license
be granted. In the Slater Mills, at Webster, Mass., a disas-
trous explosion occurred because a fireman who did not
understand English closed a stop valve instead of opening
another valve, as ordered. "Trick" questions are not used
in the examinations. Mr. Hawley said that the bill is
unnecessary; that a line must be drawn somewhere in
establishing the limits of engine size for a new class of
license, and pointed out that just above and below such a
line there is always room for complaint. He condemned as
particularly dangerous the section of the bill providing that
a third-class license can be issued to enable a man to operate
any particular steam-engine plant, there being no limit on
size here. A man has to get a job before he can get a third-
class license, under the bill. Special licenses are troublesome
and should be discouraged. Mr. Hawley brought out the point
that familiarity with marine engines and boilers by no means
fitted a man to run stationary plants. Torpedo-boat equip-
ment, for example, is different from that of a factory or
central-station plant. In one case a navy fireman knew
nothing about the location of the fusible plug in a stationary
boiler.
T. N. Kelly, Lowell, Mass., criticized the division of re-
sponsibility between the fireman and the engineer and said
that under the present law an extra first-class fireman's
license provides for correcting local differences due to water-
power service a part of the year. H. M. Comerford, Boston,
took the same ground.
Capt. George Dimand, Lawrence, Mass., opposed the bill
on the ground that it would work hardship to both employer
and employee. Division of authority between engine room
and fire room is most undesirable. The bill would allow any
fireman after running one year to take charge of any boiler
plant. This is an insufficient time for a man to grasp the
operation of the plant as a whole.
The bill was also opposed by Elmer Stevens, Cambridge,
Mass., representing the New England Power League. He con-
tended that the personnel of engineers in Massachusetts has
improved under the existing law, emphasized the fairness of
the present law, and touched upon the certainty of a square
deal in examinations. The committee reserved its decision.
At the recent convention of the Indiana Engineering So-
ciety H. O. Garman, chief engineer of the Public Service
Commission of Indiana, discussed a simple method of com-
puting a rate, which was thought fair and reasonable to
the different classes of consumers and would give a rea-
sonable return to the investor. As expressed by Mr. Garman,
the difficulty now with a great many rates placed on file with
the commission by the utilities is that they are too com-
plicated for the ordinary consumer to understand. In many
cases the latter, in trying to choose, for instance, an electric
rate, is compelled to give up in despair and seek the advice of
an expert in selecting a rate that will be economical. The
ordinary user is completely lost when he comes in contact
with such terms as "load factor," "connected load," "maxi-
mum demand," "assessed demand," "measured demand," "off-
peak load," "fixed charges," readiness-to-serve charge,"
"energy- charge," etc. The tendency now is toward a simpli-
fied rate schedule which can be more nearly understood by
the ordinary consumer.
The rate evils, as they have been discovered in Indiana, are
not so much rates that are unreasonably high as they are
rates that are grossly discriminatory. The unjust discrimina-
tions have been brought about by competitive conditions and
by lack of publicity.
The failure of the general public to realize that there is a
"readiness-to-serve charge" gives rise to a great deal of dis-
satisfaction. When they can be educated to understand that
there is such a charge, they see why it is necessary to charge
the small consumer at an apparently higher rate than the
larger one. The former feels that he is being persecuted be-
cause he is a helpless small consumer, when, in fact, in many-
cases it would not be possible to furnish him service at all
at a rate within his reach were it not for the large user.
Those officers of the public upon whose shoulders falls the
duty of fixing these rates are becoming convinced that more
simplicity is needed. It works out better to have rates that
are less scientific, so called, and more easily understood by
the greater number of consumers; and after all, the utiHty
is not so much interested in a scientifific rate as it is in the
gross return that a rate will bring. In other words, what
seems to be needed most in rate schedules is less scientific ob-
scurity, a reasonable gross income to the utility and more
simplicity and uniformity for the consumers.
420
POWER
Vol. 41, No. 12
Every correct rate should take into account three elements
of cost to the utility: Readiness-to-serve cost, energy cost,
and customer's cost. Some of the elements of cost entering
into readiness-to-serve cost are: Interest return on agreed
valuation, rentals, part of allowance for obsolescence, taxes,
insurance, and part of the operating costs. The energy cost
is made up principally of the so called operating costs, while
the customer's cost is made up of items that are directly
traceable to the customer, such as reading meter, billing,
collecting, testing meter, and the like.
To make the rate matter clearer to the ordinary con-
sumer, an example will be taken by way of illustration. As-
sume, for instance, three classes of consumers of electricity-
power, stores and residences. Assume the cost per kilo-
watt of demand per month to be $1,20, $3.40 and $4.60, re-
spectively. Assume the energy cost to be $0.01 per kilowatt-
hour and the customer's cost per month to be $0.40. Then a
table can be computed showing the varying cost per kilowatt-
hour, as the hours' use of the demand varies from 15 min. to
24 hr. in one day.
VARYING COST PER KILOWATT-HOUR AS TIME OF USING
DEMAND VARIES
Hr. Use of De- Cost per Kw.-hr,
mand in 24 Hr. Power Stores Residences
0.25 $0,223 $0,517 $0,677
0 50 0.117 0.266 0.346
1.00 0.063 0.137 0.177
1.50 0.046 0.094 0.121
2.00 0.037 0.073 0.093
3.00 0.02S 0.052 0.066
4.00 0.023 0.042 0.052
5.00 0.021 0.035 0.043
6.00 0.019 0.031 0.038
7.00 0.018 n. ci2> 0.034
8.00 0.017 0.026 0.031
9.00 0.016 0.024 0.029
10.00 0.015 0.023 0.027
1100 0.015 0.022 0.025
12.00 0.014 0.021 0.024
24.00 0.012 0.015 0.017
Mr. Garman was well aware that there were many condi-
tions and kinds of service which would seem to justify a
multitude of rates, all of which might stand the test of fair-
ness and reasonableness, but in the practical administration of
a rate schedule it seemed best to take advantage of averages
and work toward simplicity of schedule.
OBITUARY
aimg| IBoSEeir IBusirsts
A heating boiler being installed in the new Country Club
building by the C. C. Hartwell Steam Fitting Co. burst Mar.
3 on being tested, according to a New Orleans (La.) corre-
spondent. Robert Snow, in charge of the job, was badly
scalded, though he may recover. That he was so seriously
injured was thought to be due to his heroism in forcing his
way to the cutoff valve so as to shut off the steam. But for
this action it is considered likely that Ernest Keppler, a
helper, who sprained his ankle in trying to get away from
the danger, would have been scalded to death. Joseph Mar-
tinez and William L. Purduit, also employed on the installa-
tion, sustained burns of the face and hands.
Snow and his helpers had just completed the erection of
the boiler, and in making a test the pressure had been
raised quickly to capacity. It was stated that the work-
men, relying on a larger factor of safety than seems to have
existed, raised the pressure past capacity for the sake of a
thorough test.
IEUS1MES
STEMS
The E. Keeler Co. of Williamsport, Penn., has been awarded
a contract for 1* water tube boilers by the Illinois State
Board of Control. Nine of these are 300 hp. and nine 400 hp.,
with automatic stokers.
The Buffalo Forge Co., Buffalo. N. T., is sending out a
new catalog (No. 201) on Niagara Conoidal Fans. It con-
tains many illustrations of actual installations, complete
tables for capacities, speeds and horsepowers for all sizes of
fans, as well as dimensions and characteristic curves. Copies
are sent to consulting engineers, manufacturers, architects,
etc., on request.
The Tarnall-Waring Co., Chestnut Hill, Philadelphia, has
just received orders for four "Lea" V-notch recording liquid
meters in combination with Webster feed water heaters
aggregating 1,125,000 lb. per hour capacity, from E. I.
duPont DeNemours Powder Co., Wilmington, Del., following
original installation of "Lea" system by them two years ago.
Also an order for a 275,000 lb. per hour capacity "Lea" V-
notch recording_ liquid meter for the new power plant of
the Victor Talking Machine Co., Camden, N. J., following the
installation of a 150,000 lb. per hour "Lea" instrument by them
two years ago.
WILLIAM H. ARMSTRONG
William H. Armstrong, Grand Worthy Chief of the Uni-
versal Craftsmen Council of Engineers of the World, died
Mar. 16, at St. Rose's Hospital, New York City. He was one
of the best known operating chiefs in the engineering pro-
fession, in both land and marine service. He was for
many years chief engineer of the Rogers Peet Co. Building
at Broadway and Warren St.
Mr. Armstrong was an active member of a number of
engineering organizations, including Elmer E. Chambers
Council, No. 5, U. C. C. of E.; Stephenson Association, N. A.
S. E., and the United Engineers of Greater New York. He
was Past Master of Ocean Lodge, No. 156, F. & A. M.
W. H. Hoyt, C. E. 1890, College of Engineering, University
of Minnesota, member of the American Society of Civil Engi-
neers, assistant chief engineer of the Duluth, Missabe & North-
ern R.R., has been elected president of the Minnesota State
Surveyors' and Engineers' Society.
Maj. A. B. Blevins, president of the North Louisiana In-
terurban & Electric Co., died from heart failure Mar. 4 at
his home in Shreveport, La. He was the founder of the
Town of New Birmingham, Tex., and one of the earliest
developers of the iron-ore region of Texas. He went to
Louisiana in 1912 and had been working ever since on the
interurban line which is to connect Shreveport and Mon-
roe, La.
The American Boiler Manufacturers' Association has called
a meeting of boiler manufacturers and others interested,
to approve the code of uniform boiler specifications recently
completed by the American Society of Mechanical Engineers.
The meeting will be held at the Fort Pitt Hotel, Pittsburgh^
Penn., Mar. 29, at 10 a.m.
Boston Engineers' Club announces the following program
for the coming month: Thursday, Mar. 25, 1915, "Locomotives,
Ancient and Modern," illustrated talk by George W. Stetson:
Thursday, Apr. 1, 1915, Franklin A. Snow will describe some
of his contracting experiences in South America; Thursday,
Apr. 8, 1915, "Butte, Montana," an illustrated talk on modern
mine development and operation, by George A. Packard ;.
Thursday, Apr. 15, 1915, "Trees in Spring," illustrated talk
by George Winthrop Lee; Thursday, Apr. 22, 1915, "Auto-
genous Welding and Cutting by Means of the Oxy-Acetylene
Torch," illustrated talk by Henry Cave.
University of Illinois Notes — Prof. C. R. Richards, of the
department of mechanical engineering of the University of
Illinois, has designed a hydraulic absorption dynamometer,
several of which have been built in the college shops. One
is to be connected to the new 60-hp. six-cylinder Peerless
automobile engine in the mechanical engineering laboratory.
The engineering experiment station is conducting tests of
various building materials to determine their coefficients of
heat transmission. The work is being done by L. C. Lichty,
research fellow, under the direction of Prof. L. A. Hard-
ing, of the department of mechanical engineering. The
results of the tests are expected to be of especial value to
heating and ventilating engineers. Apparatus for testing
steam nozzles has just been installed in the mechanical engi-
neering laboratory. Prof. O. A. Leutwiler and Messrs. H. W.
Waterfall and A. B. Domonoske, of the department of mechan-
ical engineering, are conducting an interesting series of tests
on a friction clutch for the purpose of determining the
relative value of different commercial materials used for
clutch linings.
Accidents Due to Poor Lighting — That fully 25 per cent, of
the accidents to workmen are caused by insufficient lighting
for men working at night, is the opinion of experts who have
made a study of the subject. It is estimated that $250,000,000'
is the average annual cost of injuries to workmen in the
United States alone, and that over 50 per cent, of these acci-
dents are preventable. — "Popular Mechanics."
POWER
Vol. II
NEW YOI.'K. MAKCII 30, LU
No. 13
Uy Josh Wellbb
MaES\tef
THE salesmen "lay" for me at night, they wait
for me at morn;
I know they will be on my trail when Gabriel
blows his horn.
They take my time when I should work, they do not
seem to care ;
I have no chance to change my pants, no time to pray
or swear.
Oh, Holy Moses, Holy Smoke and Holy Mack'rel, too,
Look down at once and tell me quick, what can I,
should I, do?
I BOUGHT a monster bulldog once, with teeth like
Teddy R.;
I tied him at my office door and left that door ajar.
I chuckled low, I chuckled long, and then I chuckled
some;
I said, "We'll see some royal sport when those fresh
salesmen come."
They came at last, they came i.i force, that bloody
salesmen gang;
They had a dentist with them, and lie pulled each
blooming fang.
I BOUGHT a pound of strychnine once and put it
on some meat,
The rascals sniffed and smelled of it; they were
too wise to eat.
I nearly killed a salesman once, a sassy red-haired runt,
He talked of testing furnace gas or some such crazy stunt .
I broke his neck, I broke his back, I broke his head
and slats;
I threw him on a garbage pile to feed the dogs and rats.
NEXT morning when I came down town my eyes
popped from my head,
The salesman on the garbage pile had risen
from the dead.
He stayed and talked and talked and stayed and used
up all my day ;
At last I bought his worthless junk, there was no
other way.
I sat before my fire one night to warm my frosted foot,
A salesman cuss came down the flue and filled the
house with soot.
HE talked of scale and soot and ash and said my
tubes were bad,
My heating surface punk, or worse. He sold
me all he had.
Then when I got my nightie on, my "Now I lay me"
said,
I found another salesman hiding underneath my bed.
There is no joy in life for me, no rest where'er I go,
Some salesman's always butting in, this world's a vale
of woe.
4ND when at last I shuffle off and hike for Peter's
f\ gate,
X -*- 111 find some salesman waiting for me there
as sure as fate.
And if I give the scamp the slip and get inside the wall,
He'll steal St. Peter's golden keys and catch me after all.
Ha, ha, ha, ha, ho, ho, ho, ho, and likewise hee, hee,
hee,
At last I know what I shall do, just watch my smoke
and see.
I'LL buy a ticket right straight through to Satan's warm domain;
The bunch will all be after me, they'll all be on my train.
I'll bribe the Devil and his imps, I'll bribe them till I'm broke,
But I'll get those salesmen in the pit and pile on lots of coke.
And when one tries to scramble out he'll find me standing by,
Armed with a red-hot pitchfork, and I'll jab him in the eye.
Read the Above to the Next Salesman That Calls on Yo
422
F 0 M E R
"Vol. 41, No. 13
'roiecft wst Mimic!©
By A. P. Connob
SYNOPSIS— The Minidoka project of irrigation
consists oj the Snake River dam to impm
water whicJi supplies two main ■ which is
also used to operate he, 1200-lcw. turbo-generator
units at the power house. The current generated
is transmitted to four pumping stations at dis-
tances of from twelve to twenty miles from the
poiver plant, elevating the water from the mam
canal into canals at a higher elevation. The
pump* hare a capacity of about 125 sec.-ft. each.
The .Minidoka project, situated in the counties of Lin-
coln and Cassica, Idaho, is typical of some of the Federal
Figs. 1-6. Views of the Minidoka Power Plant
March 30, L915
POW EE
423
Government's undertakings requiring power Eor opera-
tion. In this case a storage dam 1-300 ft. long impounds
the water of an 18,000-square mile watershed and is sup-
plemented bj diversion dams 60.0 ft. long. The dams are
of tl arth- and rock-fill type, having an average height
of ">(» to 52 ft., and raise the water level sufficiently
to supply two Bystems of canals having an aggregate
length of 130 miles, and supplying 190 miles of smaller
i anals.
In addition, power is taken from the impounded waters
hydro-electrically and transmitted to pumping stations
at the terminals of these main canals where the water is
pumped to higher levels for distribution to branch canals.
At present about 6000 lew. is generated. This power is to
supply water to 70 miles of main and 60 miles of branch
ft., requiring a somewhat contracted arrangement of the
units and apparatus.
The sub-basement of the power house is in reality a
tunnel space for the passage of water through the dam
whenever 1 1 ites of the dam are opened. The
basement provides for the hydraulic portion of the plant,
such as th«' penstocks, turbines and incidental casings. On
thi main door are the generators, auxiliary apparatus and
accessories. The gallery is for the switchboard, trans-
formers, high-tension switches and the like.
'J'li!' main transformers are in the power station and
step up the voltage of the generators from 2300 to 33,000
volts, the connections being delta on the low-tension side
and Y or star on the high-tension side. A spare trans-
former is provided for emergencies. The transformers
K Future extension
m this direction
{ultimate capae'rty PLAN
of extension, 5 units)
Fn;. ;. Showing the Akilangement of the Power-Plant Apparatd
canals by means id' pumping stations located at distances
of from 12 to 20 miles from the dam. The water is stored
in Lakes Jackson and Walcott, and the average run-off
about 7,200,000 acre-feet. The altitude of the projt i I in
4200 ft. above sea level. The hydro-electric generating
units work under an average head of 35 ft.
In Fig. 1 is shown the main-dam, power house and the
high-tension transmission line, looking from Lake Wal-
cott. The power house is built of concrete and is a pa
the dam; its general appearance from the intake side i-
shnwn in Fig. 2. Interior views are shown in Figs. 3, I.
5 and <i. The maximum inside width of the building is
lo ft., and the usable width for the generators is about 20
/ H-
Samegate doses
both openings, upper
and loner
SECTION A-A
are air-cooled by means of motor-
driven fans. The air duet for the
same is suspended from the gal-
ery and is shown in Figs. 3 and 4
above the control apparatus for
the generating sets, etc.
GrENER ITOR8
The vertical-type, revolving-
field generators at present in-
stalled consist of five 1200-kw.,
111 olt, three-phase, 60-cycle
tnd two small direct-current gen-
erator exciter sets which also
run the station motor-. The
rated capacity of each alternator is I ion kv.-a. at 85 per
cent, power factor at a speed of M»t r.p.m. The gener-
ators are arranged on the mam floor and connected with
m h- extended -haft-. The 120-kw. exciters
are compound-wound, for 125 volts at 125 r.p.m.
Tt i;t;t\ is
The 1800-hp. main turbines arc of the inward-flow.
axial-1' ingL -runner type fitted with pivol gates.
Those for the exciters are 180-hp. All of the tur-
Q the arched columns in the basement,
and ladders ami passageways enable even part ;
reai U<-<l easily for inspection or repair.
KM
TOW ER
Vol. II, No. 13
The turbines are arranged for low head and arc sup-
plied with penstocks 1" ft. in diameter directed toward
the turbines at a 15-deg. angle, with curved ends to reduce
friction. Fig. 6 is a view of the governing apparatus.
The penstocks are practically self-supported and are un-
covered. The larger ones are closed by gates weighing 5
tons each, and operated by 6-hp. motors which receive
energy from the 125-volt, direct-current busses. The
gates for the exciter turbines are operated by a 2-hp.
motor. The mechanism of the gates is outside the powei
station over the gates and is inclosed. The gates are ar-
ranged to close the upper and lower outlets in the dam
South-Side Canal, and these are filled with water by grav-
ity. The latter is ahoiil !."> miles long and terminates ad-
jacent to canals known as G, II and .1. which are situated
on higher levels. A transmission line is run I'.' miles
across the countn from the power station to these canals
to feci] the motors at the pump bouses. The pumping
station No. 1 takes the water from the Main South-Side
Canal and raises it to the level of Canal (J, which is about
30 miles long. About a mile distant water is taken from
(anal G and raised to Canal II through No. 2 pumping
station. Canal II is ahout 25 miles lone, and Canal J is
fed with water from II through another station, No. 3.
] State Land
|] U.S. Reserve
• • • Transmission Line
Fig. 8. .Map oi the Minidoka Project, Showing the Area, Its Canals axd Transmission Lines
so that when the upper one connecting with the penstock
is open the lower one opening through the dam will be
closed, and when the latter is open the former will be
closed. This enables each gate to do double duty and
avoids the need of two sets. They may lie operated by
hand when desired.
The draft tube <>t' each turbine is enlarged at the end to
improve the discharge. The penstocks and draft tubes are
made of boiler iron in riveted sections. The station is
provided with a 25-ton traveling crane for handling heavj
pieces.
Gen be h.
There are two main canals running from I he dam.
known as the Main S"orth-Side Canal and the Mam
Pumping station No. I is on a transmission line on the
north side of Snake River and takes water from the North-
Side ('anal. This station is ahout "v'O miles from the dam,
by air line, and about 30 miles by following the transmis-
sion lines. These are shown in Fig. 8. The layout of the
ni is such that the transmission lines are tied in and
are run to include the various towns on the project. The
main object of the power is. however, the pumping.
The pumping stations are buildings of substantial
dimensions and are equipped with ample pumping units
for the duty expected at each location. Each station has
air-cooled step-down transformers. Exciter and motor-
generator sets are provided for the minor direct current
required for small motors and lighting in the pumping
station-.
March 30, L915
POW E II
425
The ultiinair capacity of the pumping stations in
pi raping units is as follows: No. 1. four pumping units.
ai h of 125 sec.-ft. capacity ; No. 2, three pumping units,
of 124 sec.-ft. capacity: No. 3, one pumping unit
of 125 3ec.-ft. acitj ; No. I is about the size of that
for No. 3.
Details of a pumping unit are shown in Pig. '•<. It is
driven by a 2200-volt synchronous, three-phase, vertical
motor. The pumps are of the centrifugal type, talcing the
water centralis ami forcing it out peripherally. The
]jiuu]is are arranged to he always submerged, and the
nt of water supplied and raised h\ each is con-
trolled by gates with lips, which close the ingress oings
to the pumps. The gates in each case are operated
through a lever mechanism actuated by a floal disposi I
the incoming water. Fig. 9.
A baffle plate is provided above the entrance of each
pump to keep out obstructions and to serve as a guide for
the lip-operating rods. A grating in front of the water
<st Bearing
*v fsj— - __ 1 pump
the device, so as to retain the door in an open posil
In the sectional view through the closing device, the
vertical shafi E, operated by the arm /.'. is provided with
a crank /■' at its lower end. which is connected to the linli
G with the pi-ton //. A check valve / opens to admit
the retarding fluid when the furnace door is opened, hut
prevent- the fluid from passing through the piston, when
the piston moves in a direction to close the door.
mding around the piston is controlled
by the ueedle valve A', by the adjustment of which the
flow of liquid is governed through the bypass, which
regulates the speed at which the door will close.
When the furnace door is opened it moves the upper
end of the casing id' the closing device relatively to the
spring detenl C, until the latter engages within the notch
!>. thereby holding the door open. After firing, the door
is given a slighl push inwardly, which u i detent
_, ~~-~ ,<
Vertical Section or & Pumping Unit
Details oi i :i. Moituow Fukxace System
i and permits the spring L to close the door. Tin- opera-
lion of the spring is controlled by the movement id' the
piston //. which i- governed bj the bypassing of the fluid
through the passage ■/.
This device is the invention of J. II. Morrow, chief
engineer, Greal Northern Hotel, Chicago, III.
entrance of each pumping station keeps out general rub-
bish and ice. The float mechanism has a lexer and rack
for raising it independently of the water.
The water raised by the pumps i~ diverted through an
upwardly curved pipe or duct, from which it goes to its
respective canal.
Moscow FtmrEigvce S^sttesnn
The Morrow system is an automatic furnace door-
closing device to assist combustion, to obtain the maximum
amount of heat from the find and to eliminate smoke.
The equipment consists of a check with a supplemei
device for holding the door of a furnace wide open while
the fireman is putting in the fuel, and which on the
release of the catch allows the door to -wing to a closed
position, hesitating long enough when partly closed to
allow an inrush of the required amount of air necessary
for combustion.
The' checks are mounted upon the furnace door and
are operatively connected by the links .1 (see illustration i.
with the boiler front. B is the opi ax, which is
connected to the link .1 at one end and to the retarding
mechanism at the other. (' is a spring detent, which.
when the furnace d • i- open, will engage within the
notch I>. formed in the upper surface of the easing of
IRusHes £©ir Weasalhitt ©f CsiSft~3Is'<D>:ni
The usual method adopted for calculating the weight of
east-iron pipes consists in finding the cubic contents of the
metal in inches, and multiplying that by the weight of one
cubic inch of cast iron — 0.26 lb.
EXAMPLE — Taking a pipe 12 in. internal diameter, £ in
thick, 9 ft. long, we have outside diamet.r 13 in. — 132.732
rea, internal diameter 12 in. ~ 113.097 in. area.
L13.097 19.635 sq.in. sectional area.
9 ft. = 10S in., hi
19 635 1 0 "i" cast iron, and
2120 v- I :'.:, lb.
The two flanges, or one .socket, are usually reckoned equal
to one foot length of pipe.
Another formula for calculating the weight of cast-iron
pipes is
W 2.45 (D + d) X <1' — d)
W lineal foot in pounds:
D = External diameter of pipe in inches:
Internal diameter of pipe in inches;
2.34 = A constant.
A very useful approximate rule for the weight of cast-
iron pipes is. for a pipe 9 ft. long, with flanges at each end,
and 1 in. thick, allow 1 cwt. for every inch in diameter, keep-
ing the thickness and weight proportional, either more or
less.
EXAMPLES — A 12-in. pipe, 9 ft. long, flanges at each end.
1 in. thick, will weigh approximately 12 cwt.
A 12-in. pipe, '.' ft. long, flanges at each end.
9 c\\ t.
A 10-in.
.7 cwt.
% in. thick
-Bjorling.
thick
r.'i;
pow i; i!
Vol. II, No. 13
•inisaini!
>nm\<
By W. J. A. London*
SYNOPSIS — An unusually Interesting article on
the considerations entering into the design of small
condensing turbines, with particular reference to
the Terry "return-flow" machine.
Since the introduction of the small direct-connected
turbine on a commercial basis, some eight years ago, until
recently, fully 90 per cent, of the machines called for
were intended for noncondensing service. In the few
eases where they were called upon to operate condensing,
such as for marine work, little attempt was made at
economy, as the operation of these machines condensing
was more a matter of convenience than of water rate.
It lias been acknowledged that the designing of small
turbines is much different from that of large machines,
for were a small turbine designed on the same principles
and lines as a big machine, a hopeless commercial failure
would result. There have, therefore, been two din not
fields in turbine work; the principles governing the de-
signs of small and large machines being so much at
variance that they might be said to be almost as different
as the designs of a steam and a gas engine.
3
O
I
I
n
1
1
I
1
X
2
CO
a.
\ V
\ V
T5
C
V\
c
^N^'
0!
+■
G
<?>^
"%
^22
^
orjt
5^,
^hulL
r£RRY
TYPE)
u
f-
1}
*z4
1
1 1 7
Designed Full Load in Brake Horsepower
Fig. 1. Relative Effects on Water Rati: of Varying
Diameter of Wheel 'ntj Designed Pull Load
The characteristics shown are due to increased windage
losses on the larger wheels. All curves are plotted for the
same conditions of steam pressure.
Most small turbines were installed to operate non-
condensing, being used primarily for auxiliary apparatus,
the exhaust being used in feed-water heaters. Small
isolated plants wi d noncondensing, the exhausl
steam being used for industrial or heating purposes.
For isolated plant-. 3ucb as small pumping installa-
tions of, say 150 to 500 hp., where economy was of much
importance and the saving by operating condensing suffi-
cient to offset the firs! cost, maintenance, etc., the tur-
Chief engineer, the Terry Steam Turbine Co.
bine has been at a disadvantage as compared with the
reciprocal ing engine.
The average thermal efficiency of small turbines is
in the neighborhood of !<• per cent. With this efficiency
all exhaust steam can be utilized without "blowing off."
so that no higher efficiency is required or even desirable.
Single
Row Wheel
Wheel I
3-Row
;; <iee)
1
I
1
/
jl/
Fig.
Velocity Ratio- Wheel Velocity-^
Steam Velocity
2. Relative Efficiencies of Impulse Wheels
with Various Numbers of Rows of Buckets
Forty per cent, efficiency does not represent the highest
available in this class of machine, but it is conceded to
be about the highest commercial efficiency. The cost of
small turbines varies approximately directly as the
square of the diameter of the runner, whereas the effi-
ciency is increased approximately only inversely as the
square root of the runner diameter, so any saving in
-lean, consumption must be accompanied by a marked
increase in first cost.
Above 500 to 600 hp. the Held of the large turbine.
where water-rate efficiency is of paramount importance.
is approached. These machines operate condensing in
the same proportion that the small machines operate
noncondensing, and the whole problem of design must
be attacked on a totally different fundamental basis.
For powers of, saj l"'11 to 500 hp., condensing, where
high efficiencies were desirable, the reciprocating engine
until recently bad no serious competitor in the steam
turbine. The reason for this is obvious. The recipro-
cating engine was developed, and the meager demand
iall high-efficiency turbines did not warrant the
manufacture of special machines, and furthermore, tb
i' would nut pay the price that would have to lie
charged.
Conditions have changed rapidly during the last two
1 so, and there is now a big demand for small
condensing turbines of high efficiency, both high- and
low-pressure, which has led to the development of a
third class of machine to meet the requirements of thi<
market. To distinguish this class from the small and
the large machines, it is permissible to call it the "in-
ii
i
March 30, L915
PO W E II
iv;
termediate design." This design should have as far as
possible, the simplicity and accessibility of the small
machine with an efficiency approaching that obtainable
with the larger units.
When Parsons and DeLaval built their first turbines
the main trouble was not with the turbine itself, hut with
the ■■other end," or the driven unit. A turbine is ol
little use l,\ itself, ami it was net until it was demon-
strated that it had e • to stay that generator, pump
and blower makers awoke to the fad that they must
remodel their apparatus to meet turbine requirements.
Rapid as the turbine development has been, it would
have been more so had it not been lor the slow develop-
'i' "f 'he "other end." And past events have again
repeated themselves in the field of the "intermediate
design." This machine would n,,t have been possible
u:|- divided horizontally, hut the center diaphragms and
the center-diaphragm glands were not. whereas in the
machine shown all diaphragms, and diaphragm and end
-lands are thus split, reducing disassembling and assem-
bling time lo a minimum. See Fig. ;,. right.
In the larger frames ther important change has
been made The high-pressure wl I of the Terrv type
which was incorporated in the first machine has been
superseded l>\ a two-row multi-velocity type of wheel
running a1 a high peripheral speed. Extensive experi-
ments have -how 11 that, up to certain peripheral speeds
and certain powers with a given thermal drop, the Terry
type "I' bucket is well adapted, hut beyond this range the
two-row bladed wheel has the advantage. See Fig. 5.
There are several factors entering into the correct
design of a wheel of this type other than the actual or
Wheels and Guide Vanes of Early Tkkky
had it not. been for the rapid strides that have taken
place along the following line,: (a) The manufai
at reasonable cost of high-tensile steel f0r turbine wheel,;
(b) the increase in permissible speed of generators,
blowers, etc.; and (c) the introduction on a commercial
basis of tlie speed-reducing gear.
In Poweb of Oct. 28, 1913, a brief description was
given of the return-flow condensing steam turbine that
had just been developed by the Terrv Steam Turbine
pO. for this so called ■•intermediate field."
On the completion of tests of the first machine, several
modifications and improvements naturally suggested
themselves ami are incorporated in the latest designs.
Pol' turbines of -mall power the latest tests show some
remarkably good efficiencies, as will be seen by the de-
tail- of the tests published herewith.
One of the main changes in design has been to carry
the principle of the horizontally divided case to the last
extreme. In the original return-flow mac bine the casin<*
theoretical blade efficiency, which make this problem
interesting and more complex than one would suppose
from a superficial studj of the subject on a purely blade-
efficiency basis. Disk friction, the powei transmitted
or rated power of the machine, commercial considerations
regarding lir-i eosl (which controls the selling price), are
all lug fa, -ior- independent <<( any blade-efficiency theory.
The return-flow turbine is designed so that the pres-
sure in the first stage will be about 2 to 5 lb. above
the atmosphere. With ordinary steam pressures of. say
150 lb., and allowing two impulses, the peripheral ve-
locity of the buckets niu-l be ab ut C'lii ft. per sec. for
best efficiency. At 3600 r.p.m. this calls for a pitch diam-
eter of mi ._, in. For tine,, reversals the diameter of wheel
would be in the neighborhood of 24 to 26 in.
Fig. 1 shows the relative efficiencies of three types of
wheels and the important relation that skin friction am!
windage bear to the overall efficiency. A "two-velocifrj
stage" wheel is more efficient from a blade-efficiencv stand-
428
P 0 AY E I!
Vol. 11, X... 13
poinl than a "three- or four-velocity stage" (see Fig. '.').
yet the friction created l>\ the increased diameter is far
more undesirable than one would at first imagine, and the
advantage gained 1a augmented blade efficiency is more
than offsel by the added losses in other directions.
Low-Pressure Supply
High-Pressure
m
Fig. 4.
Diagrammatic Section ov Return-Flow
Tl BBINE
The various formulas of Stodola, Lewicki, Odell and
others, for skin friction of disks, show clearly how big a
factor tin's (-in be, and while these formulas are somewhal
vague and indefinite regarding certain conditions that
have to be taken into account, they all agree that this
friction loss varies as the second to the 2.5 power of tin-
diameter of the wheel and nearlv as the cube of tin1
peripheral velocity. Again, these formulas do not take
into account the windage of the blading, which is ob-
viously greater in a bladed wheel than on & bucket wheel.
Tn reverting to the bladed type of wheel in the high-
pressure end. instead of the semicircular-type bucket, it
is interesting to note in passing that the first turbine
experimented with by E. C. Terry in 1893 was on this
principle. Pig. 3 shows the wheels and guide blades of
this early machine, the patent number of which is 508,-
190.
The Terry type of machine is, primarily and essen-
tially, a noncondensing turbine. Its simplicity and con-
sequent unlikelihood of derangement make it an ideal
machine for the duties that it is called upon to perform.
Within certain limits of speed, vacuum, etc.. the two- or
three-stage Terry combination makes an equally good
condensing machine, having a thermal efficiency as high
as Hint of the single-stage noncondensing design; but
when confronted with the necessity for high speeds, high
vacuum and larger powers, the wheel becomes imprac-
ticable at the low-pressure end owing to its inability to
handle a large volume id' steam to the best advantage.
In the later machines, therefore, the low-pressure wheel
has been replaced by a series of single velocity-stage
impulse wheels. That practically all authorities agree
that this type of wheel for low-pressure work forms the
ultimate turbine element is evidenced by the fact that
it is being adopted by practically all turbine builders of
both large and small machines, with the one exception
of the builders of the reaction, or Parsons, type; and that
this type of machine is not adaptable to small powers is
evidenced by the fact that the builders themselves resort
to the impulse principle in their smaller designs.
Again, the "composite design" of velocity staging in
the high-pressure end and pressure1 staging in the low-
pressure must be the last word in turbine development
if latest designs of practically all the turbine builders
both here and in Europe are any criterion. [See the
article on page 436 of this issue. — Editor.]
Fig. 5. Potoes of Old and New Designs or Return-!Plow Turbines
Rotor of new machine having two rows of impulse blading
on the high-pressure wheel
March 30, 1!U
POW B 1!
429
The obvious advantage of high vacuum in a turbine,
particularly in a low-pressure turbine, with the difficulty
of designing, building or keeping glands vacuum tight
without the necessity of a water seal with its attendant
25
25
26 27
Vacuum. Inches
Fig. 6. Pehcentage Increase in Poweb Available
(Theoretical) peb Incb Vacuum with
Condensing Tubbines
complete envelope of steam above atmospheric pressure,
eliminating the possibility of air leaking into the casing.
The rotor and the lower half of the casing of the return-
flow machine are shown in Pig. 5.
One other importanl feature in connection with the
arrangement of glands on the return-flow turbine is thai
ii" supplementary steam Bupply is necessary for sealing
them when tinder full load, and even at light loads any
strain that finds its way through must pass through
the low-pressure end of the turbine, thereby doing work,
whereas with the ordinary type of steam-sealed glands all
the steam which does manage to escape goes directly
to the condenser without doing any further work. That
this auxiliary steam supply can amount to quite a factor
is evidenced by various tests that have been made. Of
course, when a machine is new the glands are tight, so
that the leakage during this period is imperceptible, but
after setting the machine for commercial operation or if
it has been in operation for some time, it is hard to know
without repeated tests what this steam leakage amounts
to. In big machines this is never, however, a serious
amount, bin in small ones it can be quite a big percentage
of the total st '-a m used.
A careful analytical study of the performance of
labyrinth glands was made and published by If. M. .Mar-
piping and subsequent sediment troubles, led to the de-
parture from the orthodox straight-How principle to the
return-flow design for the elimination of this long-
standing bugbear in turbine work. This question of
gland leakage often results in trouble between the tur-
bine and the condenser makers when trying to meet
guarantees, while the customer looks on and sees the
machine run at a lower vacuum than called for and pays
the coal bill anyway.
It is often advocated that with a steam seal on the
glands and a little steam blowing outward into the engine
room there cannot be an] air leaking into the turbine.
This contention i- wrong, as has been demonstrated many
times. It often happens that there is a counter current
going on, air traveling along one part of the gland and
steam passing out of the glands in the opposite direction,
this condition being the hardest possible phenomenon to
detect. Fig. I shows diagrammatically the construction
of the return-flow turbine with the low-pressure end in a
Pig. ?. Diagrams of Link Motion Terry. Mixed-
Pressi re Governor Control (Rateatj System)
1. POSITION' when STARTING turbine; high- and low-
pressure valves open. Piston C forced down by ample
supply of low-pressure steam.
2. SPEED REGULATION: High-pressure valve closed.
Turbine running on ample supply of low-pressure steam.
3. PRESSURE REGULATION: Low-pressure supply
stopped; piston lifted by spring, closing low-pressure
valve and opening high-pressure valve. Governor is
always free to close both valves if load is suddenly taken
off the turbine.
tin. and the formula derived from bis experiments is
given in his book on steam turbines, as folio..,-:
y-88^r,(y+%/*)
where
W = Weight discharged in pounds per second:
A = Area in square feet available for flow;
P1 = Initial absolute pressure in pounds per Bquare
inch :
T, = Initial specific volume of tin- steam;
A=Xumiier of points at which the steam is wire
drawn :
/',
x = — . where /'. denotes the absolute pressure on
Pi
final discharge from the last ring of the
packing.
430
POWER
Vol. 41. No. 13
This formula checks up fairly closely with actual tests
made by the writer ou a 2000-kw. machine having a
mean labyrinth diameter of 8 in. and 12 elements or
restrictions.
From the formula it will he seen that the amount of
steam passed by a labyrinth gland is directly propor-
tional to the diameter of the glands. This diameter of
Fig. 8.
Terry Return-Flow Turbine with Rateau
Mixed-Pressure Control Mechanism
gland does not follow any relation to the output of the
turbine, and it will be seen that the smaller the machine
the larger the percentage of steam thai will be passed
by the gland i so. as mentioned above, while the amount
of steam passed by a labyrinth gland in large machines
can be an insignificant factor, it is obvious that in the
small machines it can be a serious item. For instance,
the figures mentioned above in connection with the
2000-kw. machine show the total steam passed as 1 ' '
lb. per hr. On the basis of 15 lb. per kw. this would
give a percentage loss due to the glands of 0.6 per cent..
whereas reducing this quantity in the ratio of the diam-
eter of the glands, namely, s in. to. say 5 in. on a ^ttit-
kw. machine, the gland leakage would lie reduced to
111 lb., but the percentage of the total steam consump-
tion would be increased to 2.5 per cent., the latter based
on a water rate for the smaller machines of 22 lb. per
kw.-hr.
fig. U shows the theoretical saving per inch of vacuum
in a straight high-pressure condensing and a low-pres-
sure turbine. In the low-pressure machine the vacuum
is. therefore, of much importance. We must not look
upon this as a question of efficiency so much as a ques-
tion of how much horsepower one can obtain from a
given amount of exhaust steam. Then it means that
rn ivasing the vacuum from 27 in. to 28 in. the amount
of power available from a fixed quantity of exhaust
steam is increased 15 per cent. No precaution is too
great for the purchaser to take to insure himself against
losses at this point irrespective of any guarantees that
may be given either from the turbine or the condenser
builder.
The success of the low-pressure turbine intelligently
installed is undisputed, but the bulk of the research
and development work has been along the lines of the
larger machines. The marked saving in these machines
has naturally led to the introduction of the low-pressure
turbine in small plants such as breweries, ice plants, etc..
with just as successful results as with the larger units.
Low-pressure turbines of ."in hp. and more have recently
been installed, ami many more installations are in course
of construction. With the exception of a few isolated cases
where a lixed supply of exhaust steam can be depended
upon indefinitely, the low-pressure turbine has given place
to the mixed-pressure machine, the latter having the ad-
vantage that should anything happen to the engine or
other source of low-pressure steam supply, the full power
of the turbine can be obtained when operated with high-
or mixed-pressure steam. The return-flow turbine is par-
ticularly applicable to low- and mixed-pressure work, as
the effect of vacuum in a machine of this kind is of much
more importance than in a high-pressure condensing
machine.
For satisfactory operation under mixed-pressure condi-
tions and where the low-pressure supply is liable to
decrease or fail, a special arrangement of governor
mechanism is designed, so that the high-pressure steam is
automatically admitted to make up for any deficiency in
the low-pressure supply. The system employed by the
Terry Steam Turbine Co. on its mixed-pressure turbines
is what is known as the mixed-pressure Rateau control.
manufactured under license from the Rateau Steam Re-
generator Co.. the design being modified to eliminate the
complicated oil-relay mechanism necessary on larger
machines.
The direct-connected governor of the Terry type is
used directly connected to the governor valves. The
Low - Pressure,
Met -
i DiQ 4^
Fit
\i;i; lngement of Low-Pressure Steam Ixi.et
on Return-Flow Turbine
principle of this mechanism is shown in Fig. 7, and a
photograph of the actual machine fitted with this con-
trol is shown in Fig. 8. All the levers art' mounted on
ball bearings to eliminate friction as far as possible.
The governor running at high speed has more power
than the usual low-speed geared governor and the
mechanism itself being balanced by counterweights as
March 30, 1915
?UW E B
431
shown in Fig. 8, the governor is relieved of all external
loads other than to operate the balanced valves.
In all turbine practice, both in high- and low-p
machines, the question of pipe connections and the
elimination of stresses od the turbine is well known to
be a serious problem. This is particularly so with the
w-pressure machines
ZZO
215
£210
D.
O
a.205
<D
Q
..200
<u
i
§.195
at
W
£190
1 185
ID
180
175
'
&/
w
/y
it
zooo
2500 3000
Speed in R.p.m.
big piping necessary for
again of further im-
portance in the smaller
units, which, on account
of their compacl size
and light weight are
susceptible to distortion
from outside stresses.
The common practice is
to bolt the low-pressure
valve and piping direct-
ly to the turbine casing.
This entails consider-
able risk of pulling the
tu r bin e and, conse-
quently, the whole unit
out of line, causing vi-
brations and generally
unsatisfactory running.
To eliminate this in the
return-flow turbine the
low-pressure steam sup-
ply is not rigidly con-
nected with the turbine
proper, but is bolted
to an entrainer or separator which in itself is bolted
rigidly to the bedplate (see Fig. 9). From this en-
trainer the steam is led vertically through a flexible
steel pipe which leads to the top of the turbine casing.
In this way no outside stresses due to the heavy low-
pressure steam-supply piping are thrown mi the turbine
itself. Furthermore, by the introduction of this addi-
tional entrainer. drier steam is obtainable in the turbine
than would be the case were the inlet piping connected
directly to the turbine proper.
Throughout the design of the machine special atten-
tion was paid to obtaining the best possible water rate
consistent with a compact and reliable mechanical de-
Bign, and the figures given in the table of some receni
Fig. 10. Tests of Impulse
Wheels. Showing Ef-
fect of Finishing
Blades
tests -In. i some remarkably high efficiencies lor turbines
of Mich small power.
The hist degi iency can be obtained only by
a careful stud} of the correct areas through the blade
passages an ial attention to the finish of the
ing in the wheels to eliminate friction and eddies.
By the adoption of drawn material for the blading, true
areas can I btained. Tin- machine, as built/conforms
closely to calculation-, a- ha- been evidenced repeatedly
by the careful observation of pressure drops through the
various stages, these falling almost exactly in line with
the calculated drops. The adoption of polished wheels
further enhances tl (Bciency.
Some interesting experiments were carried out to de-
termine tl (Feet of rough and finished blades and
wheels. Fi-. in shows two curves, one with rough drop-
I blades, the other with blades polished to a true
section and with the wheel polished.
The first 108-in. diameter return-tubular boiler re-
corded under the laws of the Commonwealth of Massa-
chusetts was recently built at the shops of the D. M.
br Read's fob
P] RFORMANCESOF TERRY RET! KN-I LOW TURBINES
Tut bine
Number
1383
1333
13S3
1333
1 3 S3
1383
1333
I -7!
1-71
1874
175H
1750
1750
1750
1750
17:,i >
1750
1750
1750
1750
1750
2044
2044
2044
2044
2044
Initial
Steam
I', .. Ii -
Valve, LI.
12- 3
128.8
128 -
12s s
7 03
:. _'..
2 16
- 25
1 75
1IHI 4
I
125 5
125 5
125 5
125 5
0 25
0 25
I. 25
0.25
124 7
125 II
125 0
125 II
125 II
Vac. Ex-
hau&1 . In.,
Hg. Re-
: rred to
30-In
Barometer
25 64
28 00
21 16
28 00
25 60
2:i 75
21 75
21 35
28.00
2- 57
27 36
25 25
25 25
25 25
20 01
26 el
26 HI
20 01
20 411
26.49
2- .111
26 49
20 49
Load in
B.hp.
30s 1
ill :-;
254 5
343 'i
410 'I
101 J II
321 7
233 4
119 6
11.7 ..
:;-l 'i
1,7 .1
107 5
2 '7 6
227.8
343 0
295 11
325 II
24(1 II
lsll (l
in., 1
•.- s
'is 2
Speed i
R.p.m
3640
3 140
3640
3640
2000
1000
:;.
25.KI
2102
3600
3600
: ',21 11 1
2MHI
2400
51 .. 1
1500
3500
40110
3600
3600
3600
3600
3600
Initial
-
Deg F
Superheat .
or Quality
10 6
Drv
10.0
Dry
85.0
89.0
93.7
70 5
12.0
0.981
12 5
26 9
Dry
21 o
20 0
2'. 'i
20 0
110.0
110.0
110 (I
110.0
27.4
Dry
Dry
Dry
Dry
Steam pi 1
1 1 Ictual
T..tal
Steam p. r Water
Hi. Cor- Rate pri
recti d to Kw.-hr.
Drv Steam, Actual,
Lb. Lb. Lb.
020 7 - 037G
0370
5016.0 5H09
51.09
8086 H
71.7., '. . ,
on,,.: i.
8340 ii
0220 H
3440 II
5133 0
3771 I.
0,41 1'. 'I
.,'
0s7t il
o-7l ..
i,-7l i.
0-71 ii
5105 .1
3310
.,: 12
6575
3870
0575
0575
01 8
Water
Rate per
B.hp-hr.
Actual.
19 7
2C: •>
27 111
38 I
1 , 30
16 17
1 5 26
15 71
1(12 0
41 04
2s 94
30 10
15 (Ml
Water per
B.hp-hr.
Corrected
.,, Drv
Steam, Lb
17 2'.
1 I 13
0. ....
11.77
22 (t. I
II HI
15 7s
16 59
10 13
17 ii-
IS. 82
14 30
16 62
18 10
Tin rnial
I tffiriency
Ratio "
0 535
II 501
II 401
II 520
II 019
,. 6 19
" 521
0 443
n 414
,, 597
.. 609
II 55s
.i 512
ii 604
., 587
ii 554
0 175
0 438
0.620
0 595
0.57S
0.568
0 539
0.495
Water
Rate on
Which
Ratio la
Dry steam
Dry steam
Dry steam
Dry steam
A'-tual
Actual
Actual
Actual
Actual
Dry steam
Dry- steam
Dry steam
1
Dry steam
Dry steam
Dry -team
Dry -team
Dry steam
Actual
Actual
Actual
Actual
Dry steam
Dry steam
Diy steam
Dry steam
Dry' steam
432
POAV EB
Vol.41. No. 13
Dillon Steam Boiler Works, Fitchtmrg, in accordance
with the Massachusetts state laws, for a safe working
pressure of 125 lb. The recorded number given to it
at the State House in Boston is 971.
The boiler is 9 ft. in diameter and IS ft. long. The
firebox-steel shell plates, and the flange-steel head- are
% in. thick. The boiler has 200 l-in. by L8-ft. Parkes-
burg charcoal-iron tidies, and has a butt-strap, double-
riveted steam drum 30 in. diameter by 6 ft. lung. The
hare boileT without tubes weighs 211,000 lb. (13% tons)
and complete with all castings and fittings, 84,440 lb.
( 1:2.22 tons).
v
In order to make the boiler lighter for transportation
hut sixteen tubes were put in at the time of shipment.
These were to brace the tube sheet, the rest of the holes
being plugged so that the boiler would no! sink in case
it fell overboard while unloading it from the vessel to
the lighter, or in case it was necessary to float it
from the boal to the shore. It was shipped to Porto
Bico.
The boiler is of interest on account of its large
diameter, and because it is the first of its size record-
ed under the la\\s of the Commonwealth of Massachu-
setts.
Metelknin
licsJ
Di s>peosui s vi
By OSBOEN MONNETTf
SYNOPSIS — I ml ust rial furnaces, hand-fired or
stoker equipped, specially designed to eliminate
smoke.
In studying the smoke problem it will he noticed that
there are a great many furnaces burning coal and making
l< 77J'—-4
Fiu. l. Fertilizes Tank with Modified Double- Arch Bridge-Wali
Setting
special furnaces which have no application whatever to
the generation of -team. The nature of the work
demanded of these furnaces is such as to make them
peculiarly susceptible to the making of smoke: in fact,
some of the processes require -itch a low rate of com-
bustion that it is difficult to get the proper temperature
for complete combustion. In this class one of the worst
smokers has been the ordinary hand-
fired annealing oven.
On a large scale the use of powdered
coal has successfully cleaned up this
class of plant and has generally re-
sulted in a substantia] saving of fuel
over the hand tiring, although the in-
vestment required is considerable. On
a smaller scale, or where the product
is of small size, such as automobile
part-, producer gas has been success-
fully used. Producer gas is also well
adapted for enameling ovens, and china,
pottery and terra cotta kilns.
Fig. •.'. Crude-Oil Still with Hand-Fired Coking Furnace
smoke other than those installed under a boiler. In
the various industries common to a large city enormous
quantities of coal are consumed in metallurgical and
•Copyright. 1915, by Osborn Monnett.
tSmoke inspector, City of Chicago.
Fig. 1 shows the layout of a hand-fired low-temperature
furnace in connection with a fertilizer tank. The setting,
which is of the double-arch bridge-wall design, is low.
and excavation has been made under the furnace proper.
Using the coking method of tiring and ample air admission
March 30, 1915
l'f)\v E 1;
I;;:;
for Hie semibituminous coal, tins Eurnace ran be operated
without dense smoke, hut it. requires careful attention
and this is difficult to gel in this class of plant,
A crude-oil still, with a special hand-fired Furnace
Fig. :i. Pot Annealing <>vf,\ ind Burke Gravity- Feed Furnace
""' latter any of the various gravity-feed furnaces can
'"' used. Fig. 3, showing a small Burke furnace attached
to a pot annealing oven, is typical of this class of service.
Powdered coal and producer gas arc also being used in
this work. There is probably no class
of metallurgical work in which one or
'In' other of the above fuels will not
give satisfaction.
As mentioned before, the underfeed
stoker is peculiarly adapted to special
furnace work, owing to the fact that
the necessary air I'm' combustion is sup-
plied by mechanical means. Figs. I
and 5 show typical reheating furnaces
equipped with this type of stoker.
Rotary drying is another service in
which the underfeed stoker works out
well. Natural draft on this work is an
uncertain quantity, placing at a disad-
vantage stokers depending on a stack
for their air supply. A furnace ar-
ranged for connection to a rotary dryer
is shown in Fig. (I. 'Phi. ,„'lf|jt' ls
adapted to the drying of fertilizer, gar-
bage, blood, sand, sugar-beet pulp, or
any similar substance from winch it is
desired to drive oil' the moisture.
"
Fig. 4. Jones Underfeed Stoker Serving Reheating
Furnace with Underground Breeching
Fig. 6. Rotary Drying Furnace Fitted with
Underfeed Stoker
Ocean \ <>l
cent, of the
cover all t]
In a depth
Survey.
ie to Land Area — One per
itents of the oceans would
land areas of the globe
290 ft.— U. S. Geological
v
sha ' i center.
Fni. :>. Typical Reheating Furnace with Underfeed Stoker \\i
I ^dependent Stack
arranged for low rates of combustion, is shown in Fig. 2.
This furnace is designed for the coking method of firing
with semibituminous coal. There is considerable brick-
work in the furnace, designed not only to give good
mixture, hut also to isolate the shell from the beaf to
prevent burning of the still. Too high a temperature at
any one point would he disastrous, so the furnace is
provided with a spring arch the entire length of the tank.
Coal is charged on the front of the grate and pushed down
when fully coked.
Natural <:hs and fuel oil an' also used for this and
similar work where the price is low enough so thai these
fuels may compete favorably with coal. When burning
Horsepower and Torque Defined — It is
important to understand clearly the dif-
ference between horsepower and torque.
The former is the rate of doing work,
while the latter is only one of the quanti-
ties making: up horsepower. The torque
of a motor is sometimes denned as the
pull or force exerted at the surface of
tile armature, multiplied by the radius
of the armature. For commercial pur-
poses, however, is i< defined as Hi,
pull exerted at a certain radius from the
convenience this pull is usually expressed
in pounds and the radius in feet, which, multiplied by the
peripheral speed, gives an expression in foot-pounds which
is readily reducible to horsepower. Assuming that the force
is applied at a distance of one foot from the center of the
shaft so that r (radius) = 1, then
hp. X 5252
From this it is evident that for a given motor and a
given horsepower, the torque varies inverselj as the speed.
If the first definition of torque is assumed, that is, the force
acting at the surface of the armature — it is apparent that
the torque would be dependent on the diameter of the arma-
ture as well as the speed; whereas, by the second definition,
it is independent of the armature diameter. In motor appli-
cations one is concerned with the torque exerted on th
motor shaft and not at the surface of the armature.
i:;i
I'HWEK
Vol. 41, No. 13
lpOh<=>Teinisi©ini SwMcMim> Systems
By John A. Randolph
SYNOPSIS — Factors determining the extent and
arrangement of high-tension switching equipment
to be employed, and descriptions of several of the
mure common systems in use.
in determining the arrangement of a high-tension
switching system several fundamental factors must be
considered. One is the nature of the service, inasmuch as
the scheme of connections for a lighting and industrial
service is generally different from that of a system feed-
ing railways. Another is the type of station (central
station or substation), which will largely determine cer-
tain features of the design. The magnitude and extent
of service will also have an important bearing, as will
the number of high-tension feeders and the voltage to
lie carried. The distance of the station from its center ..I'
distribution is a vital factor, as is also the space avail-
able for installation purposes. Safety to life and prop-
erty should not be overlooked, although this is perhaps
raised in eider to transmit the given power over the lim-
ited cross-section of conductor. This will permit a com-
paratively small number of high-tension switches being
used, but they will he larger and more cumbersome than
those for lower voltages. Wide clearances between con-
ductors and between live parts and ground must be main-
tained in extra high-voltage work ; therefore, more space
is required for a given amount of apparatus and conduc-
tors than in the case of lower-voltage installations. If
this space is limited it may be necessary to limit the
output of the station. Here also, the factor of safety to
life and property is of more importance than in other
cases.
The money available for construction purposes is a de-
termining factor in that it may be necessary to sacrifice
many advantageous features to save expense. This is often
hazardous, but exigencies may demand it. To conform
to this restriction it may be necessary to use but one bus,
with a correspondingly smaller number of switches, or
to otherwise arrange the switching apparatus in the sim-
FEEDERS
FEEDERS
\ \ \ Oil Switches
\ S 1.5
6<
- t 1 ''Bus
T Oil Switches
o o o o
Generators
FIG.2.
Generators
-feeder Buses
mm
o
Generator Buses
tlairj Bus
Auxiliary Bus
Generators
Group Buses
m
FEEDERS
FIG 6
of more importance in the design of the compartments
and supports than in the determination of the diagram-
matic layout. Furthermore, the money available for con-
struction purposes is a governing factor, and precautions
must be taken to insure continuity of service at all times.
In regard to the nature of the general service, it can
be slid of the railway system that, owing to the large
amount of exposed conductors, such as third rails, trolley
wires, underground contact rails and ground returns, the
liability to short-circuits and consequent interruptions
in operation is somewhat greater than on lighting systems,
especially such of the latter as are installed in under-
ground conduits. Therefore, greater precautions againsl
shutdowns are advisable I'm' the railway station.
The number of high-tension feeders and the voltage
carried will depend largely upon the extent of the service
and the distance of the source of supply from the distri-
bution center. If the generating station. f..r instance, is
run by hydro-electric power and is located in the moun-
tains a long distance from the point at which the energy
is used, it will l.e necessary to make the number of high-
tension feeder- as low as possible in order to save trans-
mission-line costs. To do this the line voltage mu-1 lie
plest possible manner, which is by no means the safest.
However, in connection with the first cost, the future
continuity of service should be borne in mind. Lack
of patronage, due to unreliable service, may cause the
-.company to lose in a comparatively short time an
| amount greater than the saving effected by limiting the
flexibility of the switching system.
Single-Bus Ststhji
The simplest method generally employed for the ar-
rangement of switches and buses on a high-tension system
is shown in Fig. 1 (the "bus'" in this case signifying one
set of busbars). One bus is used to which all the genera-
tors and feeders are directly connected, there being only
one oil switch to each generator and to each feeder cir-
cuit. Disconnecting switches S are generally installed for
isolating sections on which serious defects exist or on
which it is desired to make repairs. This arrangement
is often used in railway substations. To add to the flexi-
bility of such a plan, the machines and feeders are some-
times connected to the busbars at the same points, discon-
necting switches being placed between these points, as
in Fig. -2. This provides better facilities for the isolation
of feeders and machines with their corresponding bus sec-
tions.
The single-bus system has the advantage of minimum
space and comparatively low initial cost, but it has the
disadvantage id' not making possible the ready transfer
of machines or feeders from the sections to which they
are normally connected, to other sections. On a single-
March 30, 1915
P 0 \V E n
):,.,
bus system such as shown in Figs. I and "-'. the machines
iimI feeders always receive or deliver their energy al a
fixed point. Moreover, if a sectionalizing switch i-
openedj the sections on either side of the gap are entirely
separated and work independently.
Two-Bus System
In the larger modern centra] station-, it i- customar}
to install two buses — the main bus and the auxiliary bus.
There are several methods bj \\ liich the feeders and gener-
ators may he connected to the buses. In one of these.
shown in Fig. ■">. two selector switches with each feeder
and alternator permit a connection to either of the two
buses. Sectionalizing switches are also located at inter-
vals in each bus. With this arrangement, if it becomes
accessary to isolate a section of either bus the feeders and
machines previously connected to that section can 1 as-
dy transferred to the other bus without interruption in
the service. Moreover, if the demand on one bus becomes
so heavy that it is in danger of becoming overloaded, part
of the load can lie transferred to the other bus; or, where
two buses are used, it is possible to so divide the load on
the station that accidents occurring on one part of the
lystem will not affect the system a- a whole.
Group Si stem
An arrangement commonly employed in central sta-
tions and on railway systems using a number of substa-
tions for distribution is shown in Fig. t. In this scheme
a main and an auxiliary bus are used, but the feeders, in-
stead of having independent connections to the two oper-
ating huses. are connected to group buses which, in turn,
are connected by selector switches to the main and auxil-
iary buses. An advantage of this arrangement is that
fewer selector switches are oecessary; also, in case- of
emergency, a number of feeders can lie transferred si-
multaneously from one operating bus to tl ther, thus
saving time and simplifying the work of the operator.
Another diagram making use of a group bus for feed-
i rs is shown in Fig. 5. In addition to the main bus and
the feeder group huso, there is a series of generator buses.
Four circuits are connected to each generator bus sec-
tion— one comprising the feed from the generator or other
source of power, another a connection to the main bus.
and the other two serving to connect the generator 1ms to
two adjacent feeder group buses. The function of the
main Litis is to tie all the individual huses together and to
maintain the power supply on any generator bus after its
particular machine tias been -lint down. Furthermore.
i serves to equalize the load on all the generators. The
outgoing feeders are connected to the group buses. In-
asmuch as every group hits is connected to two adjacent
generator buses, it is possible to isolate a generator or
-roup bus without serious inconvenience to the system as
a whole. Moreover, all or a part of the main hits can be
disconnected from the rest of the system without inter-
rupting the service. Another advantage is that one or
two groups of feeders can he led from either one or two
generators independently of the rest of the system. This
affords especial convenience in testing.
An arrangement somewhat >imilar to that of Fig. 5,
but incapable of as many combinations, is shown in Fig.
6. A main operating bus is used whereby all the gen-
i rators and all the feeder groups, or both, may he tied to-
gether through tlie main bus switches S. The genera-
tors ma\ he disconnected at will as lone as the main bu
i- kept alive and the switches N are closed. Moreover,
the individual feeder groups may he isolated from the
main bus a- Ion- a- the respective generators for those
groups are kept riinniiiLj. A disadvantage of this system
is that an isolated group, if kept alive, is absolutely de-
pendent upon one particular generator. Furthermore, if
the main I'voA line of the -roup i- out of commission the
group itself is also put out id' service. The same result
"ill ensue if the generator bus is out of service. In tin
more flexible arrangement of Fig. :> these disadvantages
do not exist, inasmuch as every group has a connection
to two separate generator buses.
Multiple- Voltage System
In the systems described thus far the voltage on the
buses ha- been the same a- that of the generators. Bov
ever, where two or more services with different vol;
an1 to he supplied from one central station, it is often
fCEDERS
I i
o
QQQ
Step - DdvnUrans formers
OOOO
6600-Vo/r Generator
v^Step-UpTransformers OJ&J "£CC
t ' ' ' , ■
Fio.
advisable to install a separate bus for each service; such
an arrangement is illustrated in Fig. ?. The generator
voltage of 6600 determines the pressure of the generator
bus. However, lor the t0,000- and 120,000-volt services,
separate huses arc installed whose power supply comes
from the generator has. but with the voltage increased by
means of step-up transformers. A 220-volt bus tor low-
tension work is fed through step-down transformer- whose
primaries are joined to a 6600-voll bus fed directly from
the generator bus. For flexibility the various buses are
divided into sections, and between the-,' sections are
switches which can he quickly opened or closed at the
will of the operator.
The Expansion of steam Linen may he found by the
formula
r CX(T-t) XL
when
E = Expansion in inches;
T — t = Temperature difference:
L=Lenerth of pipe in inches;
C = The coefficient of expansion of the metal of which
the pipe i- made
The coefficients of expansion of various pipe materials
an Cast iron, 0.00 )65; steel, 0.0000067; wrought iron,
0.000006!>, copper, 0.0000095; brass, 0.0OOO105,
L36
POW E il
Vol. 41, No. L3
Hua^eiat Ifflmp^owodl Oil Falft<eir
Tlie accompanying illustration shows out' of the stand-
ard Biters now being made by Wm. W. Nugent & Co., of
Chicago. This particular design may be circular or square
in section. It is made in eight different sizes, the ca-
pacities being from 6 to 100 gal. per hr., respectively.
.Multiplication of the filtering chambers will, of course,
give an apparatus of any desired capacity. The cylin-
drical filtering and water-separating section, shown at
the top in the illustration, is independent of the reser-
Nugext Improved Oil Filter
voir, and is supplied separately if desired. A tank suit-
able for oil storage may be available at the plant and if
appearances do not count an oil barrel may be used. In
the latter case the barrel is turned upright and the fil-
tering chamber set over the open end.
From the phantom view the path of the oil from inlet
to storage may be traced. In the top part are two semi-
circular sections, one known as the dumping tray and
the rear half as the screen chamber. If the filter is con-
nected to an oiling system, the dirty oil and water which
may be present enter the dumping tray through the inlet
shown. By raising the lid it may also be poured into this
compartment. In the vertical wall separating the two
sections is a fine-mesh copper screen through which the
oil passes into the screen chamber. From here it flows
downward through a short pipe into the water-separating
and precipitating chamber. It enters under the surface
of the water, rises to the top and overflows into a central
pipe supplying the filtering bags. The water passes un-
der the inner partition, shown at the right of the chamber,
and over the second partition to the outlet.
Depending on the size of the filter, one, two, three,
four, six or eight sets of filtering bags are provided, three
in a set, all on independent rings. The two smaller ones
arc made of comparatively thin fabric, while the material
forming the largest is much heavier. An electric light
lias been provided so that the filters may be inspected
through the sliding door shown in the illustration. The
machines having four, six or eight sets of bags are sus-
pended from a central spindle and each may be rotated
to a position in front of the door. The cock controlling
tin' drip at this point may be closed and the bags in-
spected or cleaned. The pipe leading from the screen
chamber is of such a size that it cannot supply enough
oil to flood the filters. If more should come to the dump-
ing tray than can be eared for, the surplus escapes through
the overflow at the top and eventually is returned to the
filter. ( Ither features are the steam coil in the water-sep-
arating chamber and the facilities for cleaning.
Tsisirlbanae
Five years ago we called attention to the evident ten-
dency to unification in turbine types, and the adoption
by several builders of the velocity-stage for the initial
expansion, and by the builders of velocity-stage turbines
of single-velocity impulse or reaction stages for the lower
ranges. We pointed out that by allowing the initial
expansion to take place in a single set of nozzles, and
using a velocity-stage of two rows of moving and a single
row of reversing buckets to absorb the velocity so gen-
erated, the steam is reduced in pressure from, say 150, to
30 lb. before it is introduced to the turbine case, decreas-
ing the pressure upon the balancing plates or dummies,
diminishing the temperature to which the rotor drum and
hell are subjected, and eliminating the long section of
short blades, admittedly the least efficient of the reaction
turbine, on account of their large windage in the dense
medium of the high-pressure steam, and of the large pro-
portion of their clearance to the active surface.
The anticipations expressed in this article have been
realized, and we present upon the opposite page a number
of the machines of this composite type as now built by
prominent companies. The presentation is, however,
by no means complete, and should include the General
Elei trie Co. and the Westinghouse Machine Co., if not
other American builders. The builders of the turbines,
sections of which are shown, are as follow-:
1. Bergmann, Berlin.
2. British Westinghouse, .Manchester.
3. Melius & Pfeiminger, Berlin and Munich.
I. Tern . Hartford, Conn.
5. (iutcholl'muigschiitte, Oberhausen.
6. Brush, London.
7. Allgcmeine Elektricitats Gesellschaft, Berlin.
8. Brown Boveri, Baden.
March 30, 1915
p o w e i;
137
438
P 0 W E E
Vol. 41, No. 13
Bi G. A. Field
The temperature of the jacket water should be eon-
trolled to suit the individual case. For instance, large
engines require cooler cylinders than smaller ones, and
oil engines often require slightly higher temperatures
than those burning gas or gasoline, because of the tend-
ency of the oil to condense on the cylinder walls. In au-
tomobile engines the jacket water often readies the boil-
ing point without any serious results. Under average
conditions the temperature of the cooling medium on en-
tering the cylinder jacket will not exceed (iO (leg. F.
and on leaving should not exceed 160 deg.. L50 deg.
being better practice. Should the temperature of the
Arrangement of Cooling System
cooling water exceed L85 deg.. there is danger of deposit
in the jacket.
As a safeguard against incrustation of the water jacket
soda may he introduced, about a pound a month being
used for every 11 cu.ft. of reservoir capacity. The jacket
should hi' flushed out frequently. Another method is to
lill the jacket space with one part sulphuric acid and ten
parts water and allow it to remain over night.
For small engines, not hopper cooled, hut using the
tbermo-siphon system, ordinary tanks or reservoirs are
used. In tin- case the bottom of the reservoir should
not he below the water outlet of the cylinder jacket, as
the circulation is maintained solelj by the difference in
the density of the water due to the difference in tempera-
ture at the inlet ami the outlet. The height of the water
in the reservoir should not he less than four inches above
the discharge of the return pipe. The capacities of reser-
voirs of this type are, of course, dependent upon the size
of the engine and should be from -Ml to CO gal. per lip.
Water injection in various quantities directly into the
combustion chamber is also used, but lias not as yet dis-
placed the water jacket to any great extent. A very small
quantity of water is commonly injected with the fuel
of oil engines to prevent preiguition and also, by low-
ering the temperature of the burning charge, to prevent
the decomposition of the line particles of oil before evap-
oration is fully attained. This results in a decrease in the
amount of carbon deposited in the combustion space.
It is estimated that about one-third the total heat sup-
plied to the engine is carried away in the cooling water.
Manufacturers guarantee a heat consumption of from 11,-
0(1(1 B.t.u. per b.hp.-hr. for full load, to 10,000 or 30,000
B.t.u. for one-quarter load. Therefore, with a safe allow-
ance for ordinary working conditions of 12.000 B.t.u.
per b.hp.-hr.. based upon full-load rating, it will be seen
that about 4000 B.t.u. per b.hp.-hr. must be carried away
by the cooling medium,
As one B.t.u. is required to raise 1 lb. of water 1 deg.
F.. for an average range of 90 deg. it will require 4000
-^ 90 = 14."> lb. of water, which is equivalent to approxi-
mately 5.35 gal. per b.hp.-hr.
Practical experience shows that small hopper-cooled
engines require from 0.3 to 0.6 gal. of cooling water per
b.hp.-hr., while larger engines using forced circulation
should have a pump capacity of from 10 to 15 gal. per
b.hp.-hr.
An economical and efficient arrangement for recooling
the jacket water, and also providing for loss due to evap-
oration or danger of the pump failing to operate, is shown
in the attached sketch. The cooling tower may be placed
on the roof at some elevation above the engine, and it
should be iii the open air. The hot water is delivered
along the under side of the ridge at A and is sprayed
outward on each side against the sloping sides through
holes drilled in the pipe. The sides are made of fine
woven wire, which permits lice passage of the air and
carries the water down to the open tank below. Water
enters the tank from the city supply pipe until tin' level
reaches a sufficient height to dose the float valve.
After starting the engine, the valve B is opened and
the centrifugal pump is started. The pump, being at the
lowest point in the line, is always primed and the cool-
ing water immediately takes the circuit downward from
the tank through the water jacket of the engine, into
the pump, and upward to the spray and back to the tank.
Should the pump fail to operate properly or stop alto-
gether, the circulation will still be maintained: the water
being constantly replenished by the city-supply pipe
through the automatic lloat valve. After passing through
the cylinder jacket the water, instead of passing through
the pump, will (low upward through the pipe C and into
tin drain. By means of the float valve, all losses due
to evaporation are replenished, making the system auto-
matic.
The pump should, if possible, be belted to the engine.
but may be run by an electric motor. In shutting down
the engine the valve H is, of course, closed and the pump
stopped.
Mil n mi I Training Schools i" tin- United States numbered
279 in 1913, with 65,699 students.
March 30. L915
PO W E l;
439
Engine wheels of large size, especially those designed
for high rim speed, arc in many instances, being built
up with wooden rims, and many old-style cast-iron wheels
on large engines are being replaced with the modern
wood-rimmed wheel. Such a change has recently been
made at the large cotton mill operated by the Berkeley
Co., at Berkeley, If. I. The two independent Corliss en-
gines at this plant, each having a separate flywheel and
shaft, are operated together as a cross-compound, in con-
junction with an independent condensing apparatus. The
cylinder of one is 26 and of the other 52 in. in diameter,
each having a 72-in. stroke. The wheel of the high-pres-
Bure engine, 25 ft. in diameter and 88 in. width of face,
was originally of east iron, the .enters being in two pieces
forced upon the shaft, and the arms and segments, eight
of each, being east separately.
iIm' pad on the rim segment, to prevenl further di
""'"' "f the cracks. Such repairs as could be man
tween a Saturdaj night and the following .Monday morn-
ing were attended to, and the wheel was operate.! with the
niiI1 l<>ad the greater part of the following Monday morn-
ing, when it was thought wise to shut down and note con-
demns. Ii was found that the pad at both ends of the
segment adjoining the one originally cracked had devel-
oped fractures, and special steel patches had to be made
up and applied to those segments before the engine could
'"' again operated. Meanwhile, it had been determined
that the wheel, cracked as described, was not safe to run,
no matter how well repaired and patched up, and an o
was placed for ; idern wheel of such design as would
permit the engine to be operated at any desired speed and
still have a greater factor of safety than could be had
with an all cast-iron wheel.
Fig. 1.
Twexty-Kivk-Foot Flywheel with Woodeh Rim at Berkeley (E. I.) Cotton Mills
This wheel was designed for aboui 50 r.p.m., and at the
time of its installation so large a wheel, with only eight
arms and eight rim segments, was considered to have an
ample factor of .mi when running, as this ran. with a
rim speed of 65.45 ft. per sec. Later, the speed of the
engine was increased to 60 r.p.m., giving it a rim speed
of 78.54 ft. per sec, and as a matter of insurance, the
built-up iron wheel was stayed for additional strength
by applying wrought-iron hand.- on the shaft on each side
of the wheel hub and having steel stays reach therefrom to
the bolts securing the joints of the rim segments; these
being It; in number, twice as many as there were
arms in the wheel.
In this manner the wheel was operated for a consider-
able time and was carefully inspected at given periods.
Some monih> ago, during such a week-end inspection,
cracks were noticed in the pad of one rim segment at the
point where the wheel arm was holed to the rim, and
while the cracks found were not such as would indicate
anv «ssity for condemning the wheel, it was the
wi>e to apply special wrought-steel patch,., to strenj
The new wheel was designed, built and installed by the
William A. Harris Steam Engine Co., of Providence,
R. [., and is of the same size as the one replaced, bul the
hubs are in two piei es, d( signed for a .lamping fit to the
shaft instead of being forced into place, and the arms,
which an- i asi separately, are 20 in number, of oval cross-
ed lion and hollow, then' being two sets of these arms, L0
in cadi set. The rim ;- 11 in. thick, built up of white
pine, and while the new wheel i- superior in every par-
ticular to the old type of wheel and has a greater factor of
, n weighs only about the same as the iron one which
it replaces, and does not, therefore, bring any greater
weight on the main hearing, tl riginal shaft being re-
oyed. The total weight of the new wheel is about
80,000 lb., of which 60,000 are in the iron work of the
hubs and arms, and 20,000 in the Wooden rim. '!"
patched-up and repaired iron wheel was operated until
the new one could be made ready, and then, during one
1 's shutdon n, il Id wheel was removed and the
one in-tailed without removing the main shafl from the
wo
P 0 \Y E 1!
Vol 41, No. 1?
It will be noticed from the accompanying illustration
that the new wheel center, while being in only two pieces,
has double faces to accepl two sets of arms, as described.
1 his center complete weighs no! Ear from 1i> tons in itself,
while the 20 arms weigh about a ton apiece.
The work of removing the old wheel and installing the
new one was carried on under pressure, so to speak, and
in cramped quarters, and the accomplishment of the com-
plete job in one week's time was considered quite remark-
able. The wood rim was built onto the arms, piece by
piece, at the mill, each piece being securely spiked and
Fig. 2.
Showing Construction ot
Wooden Flywheel
La hue
glued, and then the completed rim was- turned up true
and faced off with three independent crowns for as mam
belts of unequal width.
The builders of this wheel have installed a number
of such wheels at various places throughout the coun-
try, and make a specialty of their design and construction.
They have recently converted two 15-ft. by 25-in. iron
wheels into one wheel of 16% ft. diameter by 54 in. Eace,
by building a wood rim onto the faces of the old iron
wheels, giving them greater strength, permitting higher
rotative speed than that Por which they were designed,
and allowing the operation of one belt where two had
previously been employed, while the cos! of converting the
old wheels into one was much less than would have been
the cost of a new iron wheel to accomplish the desired
purpose, and the time required was really not so greai
as would have been needed if the old wheels nad been re-
moved and a cast-iron one substituted.
[More stories of stupidity and ignorance competing
with "Some Original Ideas," as printed Jan. 19, 1915.']
In one of the mills of this ,-\\\ there are two "'-'-in.
by 16-ft. return-tubular boilers carrying 11<> lb. steam
pressure. The average load is about 176 i.hp. The
boilers are kept reasonably clean and oil is used for fuel.
One of the mill owners thinks he needs more capacity
for steam generation because the engineer reports that
the shell of the boiler becomes almost white-hot. After
turning oft' the oil it gradually cools down to a cherry-red.
— .1. L. Han-is, McPherson, Knit.
A few years ago I read in an article, "To stop knock-
ing give your valve more lead." Very simple, thought I,
although it had been my belief that the knock was in the
piston and not in the valve. Besides, I had always
thought that babbitt metal was better than lead. How-
ever, being a believer in following directions to the last.
letter, I took the valve, valve rod. and eccentric oft, melted
out the babbitt and substituted lead. I was firm in my
conviction that it Mould be impossible to give the valve
more lead than that. The knock did not stop at all: the
article, therefore, was wrong. Nevertheless, lead is neces-
sary and it does stop knocking. — W. F. Schaphorst, New
York City.
A prize "hone-head" trick was pulled oft on a new
Corliss engine built by one of our largest concerns and
erei ted by one of their shop men, but evidently changed
afterward. At any rate complaint was made that the en-
gine would not carry the load, in fact would "lay down"
with about quarter load. One of the best shop men was
rushed to the scene, arriving just before noon. On en-
tering the engine room the very first thing he noticed was
that the eccentric connecting-rod was connected to the
upper pin on the rocker and the reach-rod connected to
the center pin — in other words the two roils were reversed
in position. The motion being so reduced, the valves were
no1 given sufficient opening, hence the lack of power.
Taking in the situation at a glance, the shop man sug-
gested going to dinner before beginning the task of put-
ting the engine right, to which the engineer agreed. They
started out together, but the shop man suddenly remem-
bered having left his gloves, told the engineer to i>o
ahead and order the dinner and be would go back after
them. While in the engine room alone, he quickly reversed
the connections, then hastened to join the engineer in a
good dinner and "trimmings." On their return to the
engine room he suggested that the engine be started up
so that he might judge of its ailment. It. of course, be-
haved all right : then he suggested putting on the load, and
to the wonder of the engineer it carried it with case. The
engineer was kept guessing to the full satisfaction of the
shop man before being told what had happened.
This is a "sure enough." "honest injun" true story. —
/•*. /,'. Compton. New York City.
March 30, L915
PO W EE
111
By F. F. Jokgensen
The illustration is of a home-made open feed-water
heater used at a coal-washing plant. It heats all of the
feed water for four I ■">(> (rated) horsepower boilers. Ex-
haust steam is taken from a I3xl6-in. double engine, a
12x1 l-in. single engine, a L3xl2-in. single engine, the boil-
er-feed pump and a small coal-drag engine.
Nearly 9000 lb. of exhaust -team per hour is avail-
able. The back pressure is but little above atmospheric,
'eedUb/ei
Details of Be iter Construci ion
so that if all the steam were condensed 970.4 B.t.u. per
lb. of steam would be obtained, or 8,733,600 B.t.u. in
all.
About 15,000 lb. of feed water per hour is required
and its temperature on entering the heater is very little
above 32 deg. during the cold weather. The temperature
leaving the heater remains practically constant at '.'I'.'
deg. In raising the temperature of the water from -V. to
212 (leg., 180 B.t.U. per lb. is required.
The heater was made from a discarded compressed-
air receiver and it lias been in service for a year, Lining
excellent results.
$<o>t Sisimila.2* B.fc.^a. "Valises
By 11i:\i;\ 1>. Jai csom
The recent and persistent agitation of the subject of
purchasing coal cm the B.t.u. basis is of value to both the
buyer ami the seller, but if coal were bought mi the B.t.U.
basis alone, it would be likely to prove an expensive
method to the purchaser, for all coals having a high B.t.u.
content are not necessarily good for use under the boilers
of the plant for which the coal is being purchased.
Coal varies widely in ash, moisture, fixed carbon ami
volatile matter. The ash is. of course, a waste, and a low
ash ((intent is advisable because it mean- that less coal
has to be fired ami less waste material handled for a given
evaporation. Moisture is a detriment because it lniM b(
evaporated ami the heat to do this must come from the
coal, and therefore, considerable moisture means a large
waste of heat. Volatile matter may or may not be of
value, depending upon what it consists of, as well as
whether it can he burned to advantage under the boiler.
The table shows the range of constituents found in
coals Inn ing the same B.t.U. value. Take the two top row -
TABLE SHOWING WIDE RANGE IX COAL CONSTITUENTS
FOR APPROXIMATELY THE SAME B.T.U. VALUES
Volatile Fixed
Value in P. tic Moisture Matter Carbon Ash
10.001 93 36.53 33.76 20.78
10,264 3.53 20.75 17.85 27. n7
10,816 to 36.24 39.75 13.18
11,142 9.04 29.65 4.",. 57 15.74
12, 11)5 3.12 35.75 47.67 13.96
11,906 ' 25.05 53. 2S 16. 0>
12,958 4.49 40.55 17 13 7.5::
13,129 3.24 17.46 66.69 12.61
14.107 1.75 36.77 55.14 6.34
14,024 2.14 16.83 71.91 9.12
of figures, for instance; the moisture varies between 8.93
.Hid 3.53 per icnt.. the volatile matter between 36.53 and
20.75; fixed carbon between 33.76 and 47.85, and the ash
between 20.79 and VS.. si. yet the B.t.u. content is practic-
ally the same.
for most boilers as set at the present time, the second
coal shown on this list, would probably be more satisfac-
tory as regards evaporation than the first, although its
ash content is higher. This i> due to the higher fixed
carbon and lower moisture. Following these figures
right through, one can readily see that there is a wide
variation in coals. Therefore, the buyer should take into
account more than tin B.t.U., and in order to be sure that
the coal purchased is the best for the purpose, it i- advis
able to burn It under the boilers and to determine the
evaporation, and then buy by specification that coal which
give- the hot evaporation for the lowest price. Test even
carol' coal and see that it conic- up to specification. Pul
a bonus and forfeiture clause in the specification, which
will give a bonus for an increase in the fixed carbon or
decrease in the volatile, ash or moisture, and exact a for-
feiture or a decrease in price for excess of ash. moisture.
or volatile matter or decrease in fixed carbon, the object be-
ing t" obtain a coal having a maximum of B.t.u. with a
minimum of waste material. The specification should
limit the minimum amount of fixed carbon as well as the
maximum amount of ash and moisture acceptable.
A New Organisation called the Institute of Industry and
:, formed in London. The institute ho|..-s.
in.iim other things, to stimulate and encourage -standardiza
Hen in methods oi" production, organization and distribution,
o, bring about closer cooperation between s I man-
it mh! labor in industry, and to consider all legislation
which maj affect Industry. -Foreign Exchange.
442
POWER
Vol. 41. No. 13
;t ©f UNmirlb© Aiir P^inmp
SYNOPSIS — .1 pump which apparently produces
over 100 per cent, vai uum, the absolute pressure in
the chamber being less than that of water vapor
present at the observed temperature.
The editor was privileged to see recently, at the works
of the Wheeler Condenser & Engineering Co. at Carteret,
X. .].. a turbo air pump under test. This pump is of the
type in which the air is expelled by a succession of rapidly
moving water pistons. Fig. 1 shows the action diagram-
matically, the rotating Impeller throwing off streams of
water at a high velocity, which are broken up by the
pointed divisions of the compression channels into plugs
which continue their course through the channels, pushing
the air ami noncondensable vapors before them. The
pump in this form was developed by the Allgemeine Elek-
trieitats Gesellsehaft, the General Electric Co. of Ger-
many, and is built by the Wheeler Condenser & Engi-
neering Co. Fig. 2 shows the exterior of the impeller
and the renewable entry piece at the commencement of
the compression channels, and Fig. :! the pump in section.
The pump under test had a capacity suitable for about
a 20,000-kw. condenser. The purpose was to determine
how nearly it would come to maintaining a tl 'etica]
vacuum when different amounts of air were allowed to
enter. The pump was arranged Eor testing, as shown in
Fig. 4. The plugs at .1.1.1 controlled carefully calibrated
openings through which known amounts of air were ad-
mitted. The temperature of the incoming and outgoing
hurling water was measured by the thermometers at V>
ami C, respectively. The mercury column at D indicate:!
the vacuum, and the Y-notch weir K enabled the amount
of hurling water used to !»• determined.
The temperature of the hurling water as measured by
the thermometer at B was 93 deg. P., ami one would nat-
urally say that the absolute pressure in the chamber /•'
could not he less than 1.556 in., the pressure of water
vapor at 93 deg. As a fact, however, the mercury gage I)
connected with this chamber showed a vacuum of 2s. s in.
Impeller
ikammatic Section of Pump
The barometer at the time read 30.02 in. If these were
right the absolute pressure in the chamber was 30.02 —
28.80 = 1.22 in., or only 0.7 S4 of the tension of water
vapor at 93 deg. with which it was supposed to be in con-
Fig. 2. Impeller and Compression Channels Fig. 3. Showing Impeller in Section and in Situ
March 30. 1915
PO W K 1,
44;;
tact. It was nut until just alter the fourth observation, as
shown in the fifth column of Table I, when the air was
being admitted at tin- rati' of 32 cu.ft. per min., that the
pressure in
than that dm
Fig. 4. l'i Mr Arranged for Testing
the temperature of the hurling water. An explanation
suggested by the engineers of the condenser company is.
that as the water is subjected to the action of the vacuum
a small amount evaporates under the reduced pressure and
a cooling effect occurs, resulting in a lower temperature
and vapor tension, or higher vacuum, in the immediate
vicinity of the surface of the water.
It is customary at the Wheeler works to refer all vacu-
ums to a 30-in. barometer. This is done in the sixth col-
While the work of planning and erecting steam piping
Seems of minor importance, its proper execution affects
the economy and continuity of the plant's operation to a
greater degree than an equivalent expenditure mi an\ other
feature of the average power plant. The factor of safety
usually employed for pipes and fittings is from six to ten
times the working pressure they are intended for. vet
constant annoyance and even disaster follow their im-
proper erection or later oeglect. Among the chief causes
of failures of pipe systems are water-hammer, expansion
and contraction, which produce distortion, vibration, mis-
alignment, poor workmanship at joints, and corrosion.
Wat
er-hammer may
he proi
Meed
by a
grea
t var
ety o
TABLE
II
Temp.
Vacuum
of
Referred o
Temp.
Exhaust Temp 1
urling
Temp.
Circu-
Temp.
:, 30-In
bv Ther-
\\:,l.
la ting
w ater
C.iii-
Bat
ponding
mometer
In
Oul
In
Out
densal
29 '.i
.ill
.".ii
:(7
39
37
44
411
29 04
.".II
38
in
:is
43
47
29 59
■ill :,
54
38
Hi
,(S
44
4S
29 .v.'
.",:'. :.
54
38
Hi
38
44
4S
29 59
53 5
54
38
411
38
44
4s
29 54
5fi :,
58
37
111
:i7
4li
411
_"t 711
53 :,
.".4
37
III
37
411
47
29 04
.ill
52
36
38
36
14
45
conditions, some of which are difficuH to forestall or
identify, but the effect is usually the same- broken fittings
or at least loosened joints, resulting in more or less serious
damage. Any depression, or pocket, below the drainage
level of the pipe line may, under certain conditions,
accumulate condensate or water enough to produce water-
hammer, therefore such pockets should he avoided. A
\al\e so placed that water may accumulate above it
when closed, constitutes one of the most frequent sources
of water-hammer. When such a location is unavoidable
a drain should he tapped in immediately above the valve,
with the small drain valve easily accessible to the operator
when at the main valve. A short open-end drain pipe is
usually best, so that the operator may he sure the drain
is not obstructed and that the steam is reasonably tree
from moisture, before opening the main valve. This is
intended to he independent of and in addition to tin
regular drainage system. Reducing fittings on horizontal
vu\i^ are frequently responsible for water pockets. Owing
Barometer
Obseive
Reading
Vacuun
In. Mer
In. Mer
30 02
28 80
30 02
28 77
30 02
28 73
:iii u.'
28 CO
30.02
27 86
30 02
27 10
30 02
26 60
30 02
24 911
30.02
24.05
30 02
21.75
30 02
211 mi
Absolute
Pressure ;it
\n inl i
In. Mer.
1 22
1 2.i
1 29
Aqueous
\ apor at 93
Dee I
In Mei
1 556
1 556
1 556
1 5511
1 550
I 556
i , 16
1 556
1 551.
1 556
TABLE I
Ratio ..( Con-
denser Pressure
to Vap. ii Pn »■
93 Deg. F
II 7M
ii 803
ii 829
ii 913
1 3S.s
1 S77
5 97
8 27
in 112 I 556
u inn of the table, and the rat io of the vacuums so found to
the vacuum (28.444 in.) corresponding to (he tension of
aqueous vapor at '.t:i deg. and a 30-in. barometer is given
in the eighth column. This ratio would, however, be dif-
ferent tor each barometric pressure taken as a base.
In Table I 1 are given the results of a test of a pump of
the same type, but of relatively small size, connected Io
a surface condenser and with cooler water, the e lenser
working at about half of its rated capacity. Notice the
close agreement between the exhaust-steam temperature
corresponding to the vacuum (Col. 3) and as observed
(Col. 4).
[98
3 290
3 S37
5 315
I, 111!
i Ibservi a
Itanium Re-
lied to 30-In.
Bar.
28 7s
28 75
28 71 *
28 5s
27 84
27 us
26 58
21 ss
24 03 ^
21 73
l'i 'is
rapid rali
Vacuum Cor-
tesponding to
Pressun oi
Aqueous Vapor
9 : Deg F.
Referred to
30-In. Bar.
28 444
28 444
28 444
28 111
2S 444
28 III
2S 444
28 111
28 444
28 111
28 1 1 1
Ratio Observed
Vacuum to
Vacuum Corre-
sponding to
93 DeK. F.
Both Referred
to 31 -Iii. Bar
1.0118
1 0108
I 0094
I 0(449
n 97ss
0 9520
II 9345
il S7I7
0.8448
II 7(140
il ill .2 I
Free \ir. Cult
pel Min.
0 II
3 II
s 7
14.0
32 0
HI ii
57 11
89.0
HIS II
165 ii
222 7
lo the rapid rale of condensation, water-hammer iiuiv
occur if steam is too rapidly turned on long lines when
cold, even though sufficiently graded and drained for
ordinary duty. It should be borne in mind that disastrous
water-hammer ma\ occur at low pressun — even below
that of the atmosphere.
Expansion and contraction, when no adequate allowance
has been made to relieve the strain so produced, always
tend to loosen joints and often distort \al\es and cause
fittings to break. Allowance should he made for elonga-
tion with an increase of temperature to which the pipe
is subjected, equal to the difference in degrees multiplied
Ill
POW E R
Vol. 11, No. 13
by the length in Inches and divided by the constant
150,000, or 0.6 in. for each 100 deg. per 100 ft. of pipe.
The most commonly used form of expansion absorber is
the ordinary, long-radius bent pipe. So called swing
joints are also used, consisting of screw fittings so placed
that expansion or contraction will cause them to change
their relative positions by turning on the thread. Two
pairs of elbows connected by short lengths of pipe are
usually necessary. The threads for such work should be
well formed and ground in with emery and oil to make as
perfect a ground joint as possible, and after wiping off
the emery they should be well lubricated and not made
up too tightly. The extra resistance to the flow of steam
caused by the elbows is an objectionable feature in addi-
tion to the difficulty of maintaining a steam-tight joint.
The slip joint, consisting of a sleeve, smooth and true,
attached to one section of the pipe and sliding in a
stuffing-box attached to the other section, is quite com-
monly used anil lias advantages and "uses peculiar to itself.
Another form is made of a pair of large circular flexible
diaphragms of steel, copper or other metal bolted to the
flanges of the two sections of pipe and bolted together at
their periphery with a flange of large diameter between.
This forms an expansion joint of considerable merit.
A corrugated copper sleeve, with supporting rings and
having a flange attached at each end, is used where the
expansion is not too great. Care should lie taken not to
tax this joint beyond the limits recommended by the
manufacturer. Ball-and-socket joints and sometimes
unions are utilized to avoid excessive expansion strains.
Vibration is usually caused by motion of the engine
or other machinery to which the pipe is attached and
the pulsating of the steam in the pipe. If this motion,
or vibration, is rapid and violent the life of the pipe
line will be uncertain. In cases where there are several
high-speed engines which cause the pipes to vibrate in
unison part of the time- and out of step at other times,
the strain becomes particularly severe at intervals. Lines
should he free to expand lengthwise, hut their motion in
other directions should he carefully limited.
Misalignment puts severe strain on the pipe and fittings,
either in connection with expansion and contraction or
independently. If the pipe line is not straight, because
of crooked threads or flanges, the difficulty will usually
increase under heat changes, although joints that have
lo lie I'oieed mit of their natural positions or strained
when cold may sometimes take an easier position when
heated; hut such strain should he carefully avoided.
Poor workmanship will soon manifest itself when the
pipe system is subjected to the foregoing conditions in
addition to the pressure sustained. Work poorly done
through carelessness or ignorance is scarcely less criminal
than if so clone with intent lo do injury. Ignorance is
no excuse and carelessness is less than none — it is a
confession.
External corrosion is sometimes serious when a com-
hination of heat and moisture is augmented by a trace
of acid or other corrosive element in the pipe covering.
This condition is more frequently met with in under-
ground construction where, incidentally, it is the more
serious on account of (lie inaccessibility of the line. It
can usually be avoided b\ a protective coating- applied
to the pipe before (he insulating covering is put on. In-
ternal corrosion is more c mon in boiler-feed lines and
return lines from steam-heating svsteins and is sometimes
due to the action of warm distilled or nearly chemically
pure water, which readily attacks wrought iron or steel.
Water not over sit per cent, pure is not likely to attack
I he piping seriously, hut if air is admitted with warm
water containing a trace of acid there is likely to be
corrosion. Cast-iron or brass pipe will usually withstand
indefinitely the action of water lit for boiler feed.
58
Powell ""Eipeiaew*9 Vailhre
The Powell " I renew"' valve, a sectional view of which
is shown, has recently been developed by the William
Powell Co., Cincinnati, Ohio. The main feature is the
removable horseshoe disk, which is arranged to slide
over the head of the stem into a socket, thus permitting
it to swivel freely. When it is desired to remove the disk
from the stem for regrinding or renewing, it is merely
slipped from the socket. Should it become needful to re-
grind the valve, it is not necessary to disconnect it from
the pipe, but by simply releasing the bonnet and unscrew-
'Tkenew" Valve in Section
ing the large hexagonal nut the valve bonnet may be
withdrawn and a pin fitted through a hole in the valve-
stem head to lock the disk.
The removable disk is made of a noncorrosive metal ap-
plicable to most temperatures of superheated steam. To
remove the seat, a screwdriver or other flat tool is used,
which engages with the lug projecting from the inne:
circle: the seat is screwed out of the valve and a new one
inserted.
u
e
Municipal Plant Lowers Hate — The City Council of Two
Harbors, Minn., has ordered the rate charged by the municipal
lighting plant reduced to 6c. per kw.-hr. for lighting instead
of Sc, as heretofore, and a new rate of 3c. per kw.-hr. for
power. Consumers who take the power rate will be obliged
to install a separate meter. The municipal power plant is a
paying proposition, and the city officials feel that they can
afford to make the reduction in rates.
March 30, 1915 P 0 W E B 445
siuiiiiiiiijjjiiiiiuuimiiiiiiiiim^ i i "Willi iiiiiuiiiiiuiiiniiiiiiiiiiiiiiiiuiiiiiiiiiiiiiiiiiiiiuiiiiiiiiiiiiL .iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiNiiiiiiiit
To many engineers the word depreciation visualizes
difficult and wearisome arguments upon the present and
past values of power-plant equipment by theorists before
commissions passing upon the right of corporations to is-
sue more stock, maintain existing prices for service, o:
olidate with others of their kind. To others depre-
ciation means the underlying reason why the company
had to buy a new condenser or feed pump last week, after
getting a good many years of satisfactory service out of
the equipment. To still others it means the cause of
getting eight hundred dollars for a compound engine in
perfectly workable condition, which cosl originally sis
thousand dollars, but which has been obliged to make way
for a turbo-unit that will generate more horsepower-
hours per cubic foot of space in a day than the faithful
old cross-compound could produce in a fortnight.
In technical literature there is hardly a subject on which
more purely speculative matter has been written than on
depreciation. Hundreds of pages in court and commission
cases have been devoted to mere definitions of the word,
and assumptions by the thousands have been made and
will be made as to values and percentages to be allowed
for depreciation in one form or another, in trying to prove
Mime administrative policy just or some existing set of
charges proper. Probably depreciation will never be re-
duced to a plain "two-and-two-make-four" basis while
progress continues in equipment and plant design, but
men closely associated with such plant and equipment can
do much toward ridding the subject of some of its most
glaring uncertainties if they attack the problem syste-
matically and are accorded the cooperation of their em-
ployers.
Depreciation is, finally, a matter of plant life. How
it shall be offset is a problem for the statisticians, but
the basis upon which the men behind the gratings and
wired-glass windows are to proceed has a direct and in-
escapable origin in the work of the engineer. How little
we really know about this life question and how much we
assume! Surely, it is time for the engineer to begin
to contribute his observations and judgment in a broader
way upon this important problem, which is always the
unknown coefficient of the manager's equation of probable
cost. Where can the engineer lay hold of the matter ef-
fectively enough to help his employer, to add some specific
solvent to the mass of undigested and hypothetical data
which is congesting the modern industrial library?
There is only one way to go about this task and that is
by keeping a record of the installation, repairs, replace-
ments, failures, and final disposition of every piece of ap-
paratus affecting an estimate of the probable life of sim-
ilar equipment at any future time : of studying the influ-
ence of performance and of idleness upon wear and tear
and upon fitness for the service of today and of day after
tomorrow; and by maintaining sufficiently complete rec-
ords to enable the owner of the apparatus at practically
imninmiiiiiiiiiiiiiiiniiii urarns
any time to determine with least delay the total outlay of
money upon it to date compared with the initial cost. It
is not too late to begin to colled such material in mam-
plants where the original equipment still handles the
daily service. Every time a piece of machinery goes into
commission fresh from the factory, the operating engi-
neer should be permitted to acquaint himself, if he will,
with its initial cosl in a- much detail as necessary; and
the dates on which spare parts are substituted, with the
cost of so doing, should lie -.-i down as part of a definite
record which will enable the expert ultimately to judge
the probable life of such equipment without guessing.
True, the mere cost of repairs and spare parts inserted
may not throw light on the life of a machine as a whole,
but here is exactly where definite data are useful in mark
ing oil' life zoiie< which will at least indicate where monej
niu-t be spent to make good the aging of equipment and
where enough durability can be anticipated to reduce tin
annual sinking-fund allowances for final replacement.
There has been too mm h temptation in the past to assume
all-around depreciation rate- on aggregations of appar-
atus having enormous differences in lift — a policy justified
by tin.- need of doing something constructive to establish
a fund capable ultimately of putting in the equivalent in
capacity of the depreciated equipment, but none the less
a policy which must sooner or later give way to the more
scientific plan of basing life ami total cost estimates
on data gathered in plant and field. There is room for real
research in this department of engineering economy.
FlmciEtig iUhe Bflgnnm©
If then.' is complaint that water powers in the public
domain in the West are being withheld from use. the
blame must rest with the men and interests responsible for
the legislative methods which made impossible the pas-
sage of the Adamson ami the Ferns bills, urged by the
Secretarv of the Interior, approved by the President, and
indorsed by the leading conservationists of the country.
Under cover of specious arguments for states' rights, fili-
busters on buffer bills, and senatorial courtesy, the same
senators and the same interests which defeated water-
power Legislation seven years ago have again made it im-
possible this year.
The remaining water-power sites in the public domain
are of enormous value, controlling as they do the key to
the development and use of the vast water powers in West-
ern canons and stream-. Many other valuable power sites
once owned by the nation have been acquired by specula-
tive and monopolistic private interests in the past for
little or no return to the Government, and have been capi-
talized at large values on which power users have been re-
quired to pay interest in the form of power rates. Other
sites are being held unused by private owners who paid
nothing, or next to nothing, for them, in anticipation of
the needs of communities not yet developed, or for the
purpose of maintaining rates for power supplied from
plants already in operation. While independent interest-
446
POWER
Vol. 41. Xo. 13
concerned in hydro-electric development have generally
expressed willingness to accept the terms of the bills be-
fore the late Congress, some of the larger and politically
more influential interests refused even to consider the
terms.
President Roosevelt withdrew the power sites which
continue in the ownership of the people to prevent them
from being gobbled up by the water-power trust. The
"'interests" at that time were powerful enough in Congress
to prevent enactment of legislation that would allow use
of these withdrawn sites under government control and
with limited terms of occupancy and u>e. These same
interests have so far blocked and defeated the efforts of
the present Administration to secure legislation of the
same nature. Tt is apparent that their purpose is to tire
out the Government, in the hope that eventually these
valuable sites maj he given away, as have others in the
nast. It so happens, however, that the nation is fairly
well informed nowadays of the value of these remaining
national assets, and there is little probability of public
opinion ever agreeing to turn them over as a free gift to
any individuals. Fortunately for the country, delay in
water-power legislation means nothing worse than delay
in development. It is a big stake for which the trust is
playing, but it has a forlorn hope of winning, and the
longer obstructionists block legislation that would make
regulated development possible, the stronger the growing
sentiment for public development and operation is likely
to become.
Many engineers are beginning to see a lucrative field
in applying the principles of efficiency to engineering, par-
ticularly to factory power plants. Many have already
gained considerable success, which has tempted other- to
follow their lead.
Efficiency applied to power plants means actually the
elimination of wastes, these wastes being usually the re-
sult of faulty engineering when the plant- were designed.
The owner of an inefficient plant is often the victim of an
inefficient or an unfit engineer. This is a reflection on
both the owner and the profession.
Xo engineer worthy of the name is really anything
else than an efficiency engineer; his whole course of study
anil practice i< to adapt nature's law to practical needs
economically. Xo standard textbook teai bes us to design
otherwise than economically. The laws relating to the
transformation of heat energy have been known fur years.
The heating of feci water,. economical sizes and cov
of steam piping, the heating value <>l exhaust steam, etc..
are not new. Certain refinements in the apparatus used
in power work have been made, and special equipment has
been devised, much of which enables improvements t" be
made, looking to the saving of both labor and coal. At
ame Time, many of the new appliances are got up to
sell. The uninitiated owner frequently falls for the ex-
pert salesmanship employed to sell these devices. Some
salesmen call themselves, and really believe they are. effi-
ciencj engineers, owing, no douht, to the ease with which
they are able to dispose of their goods. This practice has
given the engineer considerable trouble in the work he is
now undertaking, as owners and superintendents have be-
i somewhat skeptical.
The engineer who often meets with -cant tolerance at
the hand- of the owners also has himself to blame, outside
of the bad effect caused by the exploiting of bad appli-
ani es. Looking at the matter a little deeper, we find
that almost anybody can hang out hi- shingle and prac-
tice engineering. If plausible enough, he can and does
work which afterward needs considerable attention
and expense to make it perform economically. Then again,
there is almost a department-store variety of competition
among some engineers, in price cutting, resulting in the
job being a repetition of thi- practice.
We are inclined to believe that these methods have
called attention to the need for the efficiency engineer
far more than the so called recent discovery of efficiency,
or the availability of new apparatus to secure economy,
the principles of which are old ami well understood.
Other professions, such a- the medical and legal, re-
quire their members to pas- examinations and meet cer-
tain requirement- before permission is given them to prac-
tice. The profession of engineering, although really the
oldest of them all. puts no restrictions on its followers.
Would it not be best for all concerned if consulting as
well as operating engineers were prohibited from practic-
ing without a licenser
v
Sl&epfticflSffiffi gvs a.tm Asset
Orthodoxy has little place in science. Skepticism — the
insistent desire to lie "shown," unwillingness to take
things for granted — is a real asset to the engineer. It
makes him uncomfortable enough, as everyone knows,
but it helps him master his profession and makes him of
increasing value to his employer.
It is unsafe to assume that a thing cannot be clone
merely because someone says so. Reports that a certain
policy or practice is impossible must he checked before
they are accepted. Suppose, in a large plant, a subordi-
nate engineer investigates heat losses in certain piping
and reports that nothing further can be done to remedy
the situation. If the chief accepts such a report without
checking its reasoning and conclusions, is he much bet-
ter than a rubber stamp?
Cooperation and dependence upon the work of others
are absolutely necessary today in engineering as well as
in commercial activities, but a certain class of problems
needs to be handled by direct methods, with routine
thrown out of the window. All jobs which look impossible
are of this class. Plenty of them are impossible, finan-
cially or physically, but the point is not to make any as-
sumptions. If it is a report to the "boss," let it cam' the
convincing facts and arguments, so that it can be checked
at tlie first reading. If it is a job handed down to the
engineer from his superiors, let it he analyzed from every
possible viewpoint before the answer is sent back that it
is not feasible to carry out the plan.
These are more than generalities. They fit into daily
experience. They teach that merely glancing over a report
or a drawing and putting on the ■"O.K."' with one's in-
itials without a real check of the work, is largely wasted
energy, economically unjustified. Question every propo-
sition : make it prove its right to live : and by so doing
cultivate the true scientific spirit which, combined with
a sense of financial proportion, keeps the engineer high
among the intellectual and constructive workers of the
world.
March 30, 1915 PO W E R 447
^iiiiiiiiiiiiiii:i,iii!iuiiiiiiiiiiiiiiiiiiiiiiuiiiii,iii!iiiiiiiiiiiiiiii!iiiiiiiiiiiiiiiiiiiiiiiiiiiii;iiii!iiHiiiiiiiii iiiiiiiiiiiiiiiiiiiiiiiiiiiiiinillil ' iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiii illinium mm iiiiiimimiiiiiiiiiimiiiiiiiiiiiiiiiiiimiii inn i iiiiiiiiiiiiiiiiiniiiiiiii in mu
©F2f(
n)oini(niein\C(
Reflating© Watles3 IR.eejtmaa'edl Ib§^
IRefffn^eirsitlnKag Systems
Referring to <'. B.'s question, page 311, Mar. 2 issue,
I should judge that he wished to know the difference in
quantity of water required for cooling, regardless of
the kind of prime mover used. If both systems were
motor-driven the absorption system would require three
times the amounl required for a compression system of
equal capacity.
The quantity of water needed in the ammonia condenser
would be the same in either system. To overcome the
heat of absorption we need about twice the amount re-
quired in the condenser, making about three times the
quantity for the absorption system that is needed when the
compression system is used. When the strong-liquor
pump to the absorption system is steam-driven its exhaust
and other exhaust steam available can be used in the am-
monia still, the condensate from the still can be returned
to the boilers, and makeup water for the boilers can be
taken from the water that has passed the condenser in
cither system.
In small absorption systems where closed ammonia
condensers are used, it is usual to pipe the discharge
I rum the condenser through the cooling coils in the
absorber. When this is done there will be a slight rise
in the temperature of the water after passing the con-
denser, hut there will be a rise of about 30 deg. F. after
leaving the absorption cooling coil. I have used this
water to advantage in supplying a hot-water boiler when
there was a demand for hot water about the place.
C. E. Bascom.
Westfield, Mass.
B<d£H©2's for Hsolla&edl FHaiimts
The following criticism is directed at errors, as they
appear to the writer, in C. L. Hubbard's article on
''Boilers for Isolated Plants'* in the Feb. 16 issue.
1. About the middle of the first column, page 23:!, we
read : "The heat absorbed by the water in the boiler per
pound of coal burned =
970.4 X W X q Xf
w
where
11' = Apparent weight of water evaporated in pounds
per hour.
<l = Quality of the steam.
f = Factor of evaporation.
ir = Weight ol' coal burned, in pounds per hour.
It is theoretically incorrect to introduce the quality of
the steam into the computations at this point. It should
have been taken into account in figuring the factor of
evaporation.
The total heat of dry saturated steam is made up of
two parts, the sensible heat of the liquid and the latent
heat of vaporization. If we arc dealing with wet steam of
quality '/. we have for its heat content all of the heat of
the liquid plus q per cent, of the latent heat of vaporiza
tion. Obviously, it is incorrect to take q per cent, of the
sum of both parts when we should have used one part in
its entirety and 7 per cent, of the other part.
2. Near the bottom of the same page, is stated: "W.P.
= Water rate of the engine under given conditions of
feed-water temperature and steam pressure ."
The steam consumption of the engine is independent of
the feed-water temperature and the words in italics
should he omitted.
3. The last sentence of -the article, near the top of
page 2:1 1 reads: "All heating requirements are reduced
to pounds of steam per hour and the result divided by
34.5 to find the boiler horsepower." This should read:
"the result multiplied by the factor of evaporation and
divided by 34.5 to obtain the boiler horsepower."
T. B. Hyde.
Lakewood, Ohio.
Caiflc^Egi&airjigi Frnfflm-p SEapp>sig|©
The letter on the subject of calculating pump slippage,
by George L. Sullivan in the Dec. 29, 1914, issue, page
928, indicates a practical, though somewhat inaccurate
way of determining pump slippage.
The slippage of a pump depends not only on the amount
of the fluid slipping by the piston, hut a great deal of it
is due to the fluid running back before the valves close.
Therefore, at medium speeds, the cylinder is not quite
Riled to its capacity at each stroke of the piston. Thus,
it is evident that unless the slippage is determined by a
calibrated flow meter, or by weighing the water, the re-
sult will be inaccurate.
For small and medium-sized pumps it is practical to
connect a number of barrels or other receptacles in series,
so that by connecting the discharge with one of the barrels,
the water will run over and flow into the next barrel.
Knowing the capacity of the barrels, the slippage may
he determined bj subtracting the number of gallons of
water in the barrels from the theoretical capacity of the
pump, or,
s
231
where
S = Pump slippage ;
Q = Quantity of water in the barrels in gallons;
a = Area, of the cylinder in square inches;
I = Length of stroke in inches;
n = Number of discharge or working stroke- re-
quired to fill the barrels.
The pump should he allowed to make a few strokes
before discharging into the barrels. Care should be
taken to get the pump up to the normal working speed
and pressure as soon as possible.
For la rye pumps this method is not practical, as the
barrels will be filled too quickly.
Providence, R. I. Samuel L. Robinson.
448
p o w b i;
Vol. 41, No. 13
The writer, having cead the article by Professor Stumpf
in the Mar. 23 issue of Power, entitled "Kecent Develop-
ment in the Construction of the Uniflow Engine," must
take issue with the author on several points, especially the
paragraph reading as follows:
It is wrong in principle to build uniflow engines for con-
densing service with auxiliary exhaust valves. The short
compression is wrong, and just as wrong is the increase of
clearance space and surface connected with these valves.
Even when used for noncondensing service with steam pres-
sures as used in modern power plants, auxiliary exhaust
valves show no gain.
The reason for the adoption of the auxiliary exhaust
valve, as applied to uniflow engines by the Skinner Engine
Co., is to allow them to be operated noncondensing with-
out the addition of wasteful clearance spaces which would
otherwise be indispensable. It will be of interest to the
reader to learn what these valves accomplish.
\\ hen the engine is running condensing, these valves are
not in operation: but their function on a condensing en-
gine is to relieve the cylinder of dangerous compression it'
the vacuum should suddenly break. In this event they
operate automatically, and the engine continues to run
noncondensing and with high economy.
The reader will understand that, with compression
extending during 90 per cent, of the stroke and with
atmospheric pressure in the cylinder at commencement,
as would he the case in a uniflow engine without auxiliary
exhaust valves, operating noncondensing, the compression
would become so great as to endanger the cylinder. The
greatest prejudice against the uniflow engine that Euro-
pean builders have had to overcome was the fact that so
many cylinders had been cracked through the central ex-
haust ports, owing to this excessive compression when the
vacuum broke
Two cylinders were thus wrecked at the plant of
Vivian & Sons, Hafod Copper Works, Swansea. South
Wales: ami many other wrecks in Europe have been re-
ported. The writer's understanding is that several cracked
cylinders have occurred in this country on condensing uni-
flow engines not equipped with the auxiliary exhaust
valves. Such accidents prove that cylinder relief valves
cannot effectually relieve this compression; and in no case
that lias come under the writer's observation did the com-
pression lift the steam valves a sufficient amount to relieve
the cylinder of the excessive pressure.
The clearance volume required for these auxiliary ex-
haust valves is less than 1 per cent., even on small engines,
and about !/2 Per cent, on large engines. Therefore, the
uneconomical effect of these clearances is negligible.
The last statement in the paragraph quoted, "Even
when used for noncondensing service with steam pressures
as used in modern power plants, auxiliary exhaust valves
show no gain." is incorrect.
The professor condemns the use of auxiliary exhaust
valves, on account id' an increase in the clearance of less
than I per cent, which is made necessary by their employ-
ment, when, if they are eliminated on a noncondensing
engine, it is necessary to employ a clearance space amount-
ing to 1 I. '2 per cent, for an engine operating under 1 "20
lh. steam pressure at throttle, with atmospheric exhaust,
and 17.3 per cent, if the hack pressure at the cylinder is
3 lb. above atmosphere. Still greater clearance must be al-
lowed if superheat is added or if the boiler pressure is
lowered.
There are two methods of obtaining this clearance —
one by employing separate clearance pockets arranged to
he placed in communication with the cylinder when the
engine is operating noncondensing, as shown in Fig. 1,
and the other by concaving the ends of the trunk piston.
The former method is especially disadvantageous on
account of the large additional surfaces introduced. In
fact, published economy curves of noncondensing uni-
liow engines having these ilea ranee pockets show that they
are not as economical as many counterflow engines
l'.\ the second method, besides having the handicap of
additional clearance, the engine cannot he operated con-
densing with even fair economy without substituting a
flush piston ami thereby reducing the clearance.
With either method the clearance volume is lixed for
noncondensing operation and. in an existing engine, can-
not be varied to suit the changes of steam pressures, steam
temperatures or exhaust pressures.
Fig. "2 is a noncondensing indicator diagram from a
cylinder id' the construction shown in Fig. 1. The amount
of (lea ranee required for noncondensing operation with a
predetermined steam pressure is shown at the left, in
proportion to the stroke id' the engine.
That Professor Stumpf realizes this point is proven
by the following excerpts from his well known work "The
Ona-Flow Steam-Engine." Speaking of the uniflow cylin-
der as applied to locomotive practice, where his own curves
show that for a boiler pressure of '24"2 lh. (which is, of
course, much greater than is employed in stationary
plants) a clearance of 8 per cent, must be employed for
saturated steam and 10 per cent, for superheated steam,
ami where for 154 lb. pressure he admits that 13.2 per
Roiler Pressure
cent, clearance must be employed for saturated steam
and 16.] per cent, for superheated steam — all on the basis
of atmospheric exhaust — he says:
1. The volume of clearance space should be kept as small
as possible.
2. The amount of clearance losses depends upon the vol-
ume of the clearance.
3. The volume of clearance space is dependent upon the
pressure and temperature of admission steam.
4. In all cases the pressure at the end of compression
must not exceed the initial pressure.
5. Possible lines of development would be to employ
saturated steam, introduced into the cylinder in as dry a state
as possible, and superheated only a few degrees, and at a
pressure that is at present usual in compound locomotives,
so that the clearance space and the loss entailed thereby may
be reduced.
March 30, 1915
P 0 W E 11
449
In other words, he practically condemns superheat
for noncondensing uniflow locomotives, because it makes
necessary still greater clearance. The reader should bear
in mind the fact that the pressures carried in modern lo-
comotives arc much higher than those employed in station-
ary plants, and that the clearance, therefore, may be less,
but the professor wishes to reduce this clearance still fur-
ther by employing saturated .-team.
Boiler Pressure 125 lt>.
boiler Pressure 1501k
Boiler Pressure 1251k
6. Other means for improving the action of the uniflow
engine for locomotive work are to increase the boiler pres-
sures and, consequently, the compression, so that the clear-
ance volume may be reduced.
In other words, pressures from 235 to 260 lb. are not
high enough for the economical operation of a large-clear-
ance noncondensing uniflow engine.
7. Comparative tests with uniflow and counterflow en-
gines, working with superheated steam of 11 atmospheres
(161 lb. gage), have shown that the advantage rests with the
uniflow engine for light and medium loads, but for heavy and
overloads the advantage rests with the counterflow engine.
Here he admits that the large-clearance two-valve
uniflow engine is not as economical on heavy loads as the
counterflow type. Such is not the case with the small-
clearance Universal Unatlow engine employing auxiliary
exhaust valves which require the small clearance of less
than 1 per cent, which Professor Stumpf objects to, as is
proven by the reproduced performance curve of a Universal
Unaflow engine operating noncondensing, with saturated
steam at 136 lb. initial pressure.
Kg. :! -bows the Universal Unaflow construction, with
{auxiliary exhaust valves, which have the effect of delaying
the compression to that point where it is usual to start
the compression in a noncondensing counterflow engine.
This construction allows the use of small clearances, even
when operating noncondensing, which is not practical
with the two-valve uniflow engine. Fig. 4 shows the dia-
gram which it makes.
As a further proof that Professor Stumpf realizes the
disadvantages of large clearances, it is only necessary
to call attention to the fact that he sought to employ
small clearance in a uniflow engine when operating non-
condensing, by providing an auxiliary exhaust valve in the
piston, which had the effect of delaying the compression
beyond the point where the piston covered the central ex-
haust ports.
The European uniflow engine is. primarily, a condensing
engine, for the reason that except in isolated cases all
power plants in Europe operate with vacuum. In America.
however, the great majority of plants operate noncondens-
"' ~
the uniflow engine to noncondensing work, which meant
the employment of auxiliary exhaust valves to delay the
compression, appealed to American engine builders b
it was seriously considered abroad.
This prim iple, however, ha- now been adopted by a
prominent German builder, and a description of this en-
gine has been published in the European mechanical press.
One American builder, after having built and thorough-
ly tested a noncondensing uniflow engine having no
auxiliary exhaust valves, now refuses to bid on the uni-
flow engine lor n rondensing service.
The Skinner Engine Co.. to determine the relative
values of the two types under discus-ion, has made elabor-
ate tests on both, having built a two-valve uniflow engine
tor this purpose. The results of these tests were greatly
in favor of the engine with the auxiliary exhaust valves,
especially when the steam pressure was changed from that
tor which the clearance in the two-valve uniflow engine
was desig aed.
It was also demonstrated that the capacity of the cyl-
inder was reduced owing to the long duration of compres-
sion, namely. 90 per cent, of the stroke; and this reduction
of cylinder capacity compelled the employment of a larger
cylinder. This in turn would impose greater stresses
on the engine and decrease its mechanical efficiency.
The Universal Unaflow engine, which has auxiliary ex-
haust valves, has obtained mechanical efficiencies in excess
of 9T.5 per cent., proving the correctness of the principle
from a mechanical standpoint.
Professor Stumpf has admitted that, with a noncon-
densing uniflow engine having no auxiliary exhaust valves,
the volume of clearance is dependent upon the steam and
exhaust pressures, and that it should be greater for sup-
erheated than for saturated steam.
Figs. 5, (5 and T show the different clearances required
for two-valve large-clearance uniflow engines operating
noncondensing, under different steam- and exhaust-pres-
sure conditions. The full vertical line at the left of the
diagram indicates the amount of clearance required in
proportion to the stroke for different pressures of satu-
rated steam. The dotted vertical line at the left shows the
additional clearance required if the engine is to operate
against -5 lb. back pressure above atmosphere.
In many plants the steam pressure fluctuates consider-
ably and heating requirements render it advisable to em-
ploy a greater back pressure on a noncondensing engine
during the cold months: and. inasmuch as it is im-
possible to vary the clearance in an existing two-valve
noncondensing uniflow engine for the changes in steam
and exhaust pressures, the engine is not as flexible or as
efficient under these variable conditions as one employing
auxiliary exhaust valves in connection with small cylin-
der clearanci -.
Fig. 8 is a double indicator diagram of a noncondensing
Universal Unaflow engine (full line), superimposed on
the diagram (dotted line) from a large-clearance uniflow
engine having no auxiliary exhaust valves, both engines
exhausting against a slight back pressure. The Univer-
sal Unaflow engine has 4.3 per cent, clearance, whereas
the large-clearance uniflow engine must have 18.4 per cent.
clearance for saturated -team.
With the large-clearance uniflow engine, the shaded
section .1 must be added to the diagram to offset the
loss in area B caused by early compression. This loss m
area is compensated for only by the addition of more
450
P 0 W E R
Vol. 41, No. 13
steam, a later cutoff, a higher release ami less expansion.
The writer, however, readily agrees with Professor
Stumpf on one point, namely, the necessity for the em-
ployment of steam-tight valves. Valve leakage in a non-
condensing two-valve uniflow engine would Vie of more
• in, iii~ consequence than with a noncondensing uniflow
engine having auxiliary exhaust ports loeated between
the ends of the cylinder and the central exhaust ports,
for the reason that the effect of this valve leakage would he
in evidence during 90 per cent, of the compression stroke,
and such effect would be to increase greatly the final com-
pression pressure. With the same amount of valve leak-
age on a uniflow engine having auxiliary exhaust valves,
the effect of leakage operates to increase compression dur-
ing only 25 or 30 per cent, of the stroke.
Nevertheless, it is well to eliminate even this valve
leakage, and this has been accomplished in the case of
the Universal Unaflow engine by the adoption of a self-
expanding poppet valve.
A. D. Skinner.
Erie. Penn.
Mess, cells
The discussions during the past year in Power, with
regard to the allowable pressure on convex drum heads,
were of a purely technical nature, in which the aim was
to discover the proper Factor of safety, having in view
explosions due to failure of convex heads near the rool
of the flange, by the tearing out of a circular section. It
was pointed ou1 b] him- writer that the factor of safety, 5,
assumed in all rule- in this country was entirely too
lew and that a higher factor, at least 8.33, should be
used. F. <.. Gasche, in discussing the subject advocated
a factor of safety of 15.'?. based on a thorough analysis
nf the .: ■< set up on such heads. Since that time an-
other disastrous failure has occurred, resulting in heavy
property damages and personal injuries, that also adds
to the proofs of the fallacy of the factor of safety (if 5.
In this connection I would mention recent tests to
o ' ave heads that failed under hydro-
static tests. Tin- vessels were tanks or drums, ha
the following dimensions: Diameter. 114 in.: shell plate.
1 in.: Ion- seams, butt, double-strapped, triple-riveted,
with an efficiency of 80 per cent.; tensile strength of
- and shell, 55,000 lb.; thickness of heads, l1* i»- :
11 t-in. radius and single-riveted to the
shell. The required pressure was 150 lb., which gave
tor of safety of 5 in the shell. The sketch shows how
the heads were put iii. one being concave and the other
■. The heads were from the same block, being dupli-
cates in each case. Moreover, the drums were new and
were tested where built.
The first drum failed at about "210 lb., the failure occur-
ring in the B head near the flange and also by tearing
the shell near the head seam. The second drum failed by
two ruptures in the head, the shell developing no de-
fects, but the failure took place at 150 lb.
Commenting on this, I am of the opinion that the head
in the first tank was harder or -tiller than in the second,
inasmuch as the shell was injured. In other words, in
the second case the head sprung in the center enough to
cause it to rupture at a point relatively near the flange,
and in the first one the head was strong enough to force
a rupture in the shell adjacent to the head.
It seems to the writer that tests to destruction must he
accepted as conclusive practical results on which to base
deductions to determine the safe working pressure. To
this end let us compare the results with the present rule
as follows :
P =, Working pressure allowed:
/ = Thickness ;
T.S. = Tensile strength :
B = Radius, or % diameter of drum ;
5 = Factor of safety.
Then
P =
t X T.8. H X 55,000
R X o
57 X 5
217 lb.
as respects tlie A head, and 0.6 of this, or 130 lb. on I',.
Using the factor 8.33, the pressure allowed on .1 would
lie 130 lb., and on B, i!).8 lb. This gives a real factor of
about 2, based on the 150 lb. at which failure occurred.
By Mr. Gasche's factor, A would fie allowed 71.4 lb.
and B 42.8 lb., making the real factor about •'! on tin' con-
cave head. In all the above calculations the tensile
strength is taken at 55. lb. per sq.in.
Se< no\ through Drum That Was Tested to
Failure
Granted a test to destruction i- accepted a- a practical
method in determining the safe allowable pressure, and
assuming that there should lie a factor of 5 to safeguard
ist accident during the presumed life of a
then the pressure allowed would he one-fifth the burstinj
sure, or 30 lb.; as regards the weakest part, namely
the concave head.
In discussing these failures of concave heads we hav<
tlie empirical rule of allowing six-tenths the pressure al-
lowed on convex head-, but one can readily see that tin
- set up are vastly different from those on convi
heads, especially when it is considered that a vessel sul
jetted to internal pressure tends to assume a spherii
shape, and an inquiry as to the foundation of this rule i
in order.
Aloii" this line it seems t" the writer that our tee
eal colleges might well take up the matter of convex at
e heads and make a thorough inquiry and give tl
results to the public. They have facilities for doing re-
search work of this sort that are beyond the practical
man in the field. Surely the situation warrants investiga*
tion. where the factors of safety vary from 5 to 15. and
only in the latter is the efficiency of the (usually) single-
riveted joint taken care of. and such joints are only
about 5(1 per cent, as strong as the plate.
P. HoGAN.
New York City.
March 30, 1915
POWER
451.
PiracftieavE Puastmp SMpp&gg© Test
In a Large pumping station the amount of slippage was
based upon the difference between the calculated dis-
placemenl and the meter reading. At one time the station
slippage recorded was abnormally high. As the combined
output of all the pumps entered the same main, some
test was accessary to locate the responsible pump.
To do this the station was operated for a specified
time with each pump shut down in turn. The pump that
was old of service when the best slippage record was made.
was identified lor special test. The suction side manhole
plates "civ removed, ami water was then bypassed to the
disc haivv chamber and allowed to accumulate a pressure
there. Large quantities of water rushed from the suction
manholes. This indicated that no mistake had been made
and resulted in a derision to rewilve the pump.
1'JiW Mil) T. BlNNS.
Philadelphia, Penn.
BDxqpIlosHOKa of InlcD&^Wsvtleir TgvimlrX
Power plants are not the only scenes of disastrous
explosions. On Oct. 20, 11)11. at about 10:30 p.m. on
the premises at 18 McCann St.. llion, N. A', a hot-water
tank exploded, with the results shown in the reproduction
of photograph taken the rning after ( Pig. 1 ).
An investigation showed that a system id' installing a
pressure-reducing valve between the street main and the
dwelling is in vogue in the village, as shown in the sketch,
PlS. 1. CONDITK
if Premises afteb Explosion
Pig. ;!. The reason for this is that the pressure in the
mains is upward of 150 lb. per square inch at many point-.
Houses on the -h.pc- or top- of hills do not have c\
traonlinary pressure, but the majority of dwellings ami
business places have this system with a reducing valve,
as shown in Fig. :i.
As such valves are absolutely nonreturn, when o
placed in a dwelling without a safety valve id' some kind
on the house side, there i- no automatic means of re-
lieving the pressure if it goes hey I that for which the
reducing valve is adjusted. The only means of release
is opening some of the various taps by hand.
The family in this case left home to spend the evening
with friends, leaving the gas jet burning under the
heating coil attached to the hot-water storage tank.
This allowed the pressure at the weakest spot to reach the
bursting point. Without the reducing valve in the system
the pressure would have relieved itself into the city main.
That the stop-cock i h- \1 to tin- street was open was proved
by the fact that the first man to arrive on the scene after
the explosion closed it to prevent further flooding of
the premises.
In this case the weakest point was the lapwelded type
hot-water tank in common use, which let go alone- the
longtitudinal seam from end to end. The force was great
enough to tear the seam apart, turn the sheet out flat
Fig. 3. Type of Reducing Valve Used
Street Main
X House oupply
' 'Stop Cock "^-Pressure Reducing Vafve
Fin. 2. Diagram or Piping System
and double it over from end to end as usually happen- in
such ca
This accident shows that the authorities should insist
on the use of safety valves where reducing valve
installed or should not allow the us-e of the latter at all.
152
POWER
Vol. 41, No. 13
The wrecked dwelling has been rebuilt and the water
system installed in this same place without the reducing
valve. There are many other places where the old system
is in use, and no attempt has been made to correct the
fault in such installations. Other municipalities have the
same conditions, and other explosions have occurred from
the same cause. All should take warning, for the con-
tinuation of this system will mean more loss of property
and possibly loss of life, which will amount to criminal
i agiigence on the part of those who have the power to
correct this condition and fail to do so.
Hubert E. Collins.
Utica, N. Y.
T@§ftnia^ for Opesa Clifcasaft
In the Feb. 9 issue, page 195, there was described a prac-
tical method of testing for an open circuit in a starting
resistance. This is to close the line switch, throw the
starting-box arm on the first contact, and then bridge be-
tween the contact buttons with a piece of metal, such as
a screwdriver. Of course, the motor will start if the
metal bridges across the open-circuited part of the re-
sistance.
The scheme is possible and no doubt has been used
safely by the writer of the article. Nevertheless, it seems
dangerous. An open circuit means full line voltage at
the break, under the conditions specified. Would one
use a screwdriver to close a 550- volt circuit? When the
test is made, practically the resistance is in circuit, but
should the screwdriver slip and bridge across the contacts
at opposite ends of the box, injury to the operator's eyes
might result.
R. E. Plimpton.
Brooklyn, N. Y.
©IE Se;psvs=ei&©s' FsvSIl©dl ft® W©e=1s
An article in the Nov. 3, 1914, issue of Power, page
650, by T. W. Reynolds, under the above heading, is
faulty in the application of the figures arrived at as a
solution for the failure of the separator drain to work.
»/b Atmosphere
\b.P.YoIv
1-or. vaive
.Oil Separator
fn. ' t . ,
Heating main, j
"steam at 5"
' of vacuum
Exhaust
from Pumps
Seal
ToSener>
Seal for Oil Separator
Mr. Reynolds has treated his problem as though the
vertical drain pipe from the bottom of the separator
dipped directly under the surface of water and oil in a
cistern open to the atmosphere. His solutions are correct
for this condition, and the dimensions given will work
out in practice.
For the arrangement shown in the diagrams, however,
the dimensions given are incorrect, for the following
reason: With the siphon type of seal (this is the type
shown in the sketches) the liquid discharged from the
separator must all pass over the crest of the siphon, and
the limiting height for proper discharge will be the
distance between the crest of the siphon and the allowed
height of the liquid in the separator, not, as Mr. Reynolds
has erroneously assumed, the sum of the distances from the
crest of the siphon to the level of the liquid in the
separator and the length of the riser leg of the siphon.
This being the case, it is evident that the arrangement
snown in Fig. 3 is no better than that shown in Fig. 1
for removing drips from the separator under a vacuum
of 5 in.
To fulfill the conditions given in .Mr. Reynolds' article
the distance between the crest of the siphon and the bot-
tom of the separator would need to be about six feet instead
of four feet as shown m Fig. 2. This gives a column of
liquid above the crest of the siphon equal to 6 times 0.434
lb. per sq.in., or 2.604 lb. per sq.in.. which is slightly
in excess of 5 in. of vacuum, which equals 2.46 lb. per
sq.in.
With the six-foot dimension instead of the four-foot
dimension shown in Fig. 2 of Mr. Reynolds' article, the
siphon seal will properly remove all the condensation and
drips collected by the separator, and if the riser leg
of the siphon were made six feet also (keeping Jie crest
of the siphon six feet from the bottom of the separator,
as before outlined) the seal would properly take care of
the drips collected by the separator under all conditions
of pressure in the heating system fnm 5 in. vacuum to
about 2!/2 lb. back pressure, that is, pr?.,sure above the at-
mosphere.
P. N. Robertson.
Denver, Colo.
•Interesting in this connection are the letters on "Trou-
ble with Oil Separator," Feb. 9, page 207. and Mar. 9, page 344.
The only thing that is wrong -vith Mr. Reynolds' pro-
posed remedies is that they are no better than the original,
and besides, the figures he uses are for water at 39 deg.
F., and not for cylinder oil, although water of condensa-
tion will be caught by the separator also.
The original layout has two faults. One is that the
top of the seal is too near the same level as the bottom
of the separator. Another is that the seal is not deep
enough. As the pressure in the main will sometimes be
atmospheric, the depth of the seal should be such as to
make it safe at atmospheric pressure.
Cylinder oil weighs about 0.39 lb. per square inch per
foot of column. 1 would make the height of the seal
rather more than
After being in operation for a few minutes the discharge
side of the seal will be full of water and this column
of water 3.15 ft. in height will counterbalance about 3.5
ft. of oil. T would therefore place the top of the seal
^+(3.5 — 3.15) =6.05/?.
below the bottom of the separator.
His sketch Xo. 3 would not do for any degree of
vacuum.
R. McLaben.
Medicine Hat, Can.
March 30, 1915
POWER
453
[um%» Jf<
SYNOPSIS— Will Quhz, Jr., has a lot of ques-
tions to ask Chief Teller about the hydrometer
and the various graduations on it.
"Have you tested the brine in the cooling tank lately,
Will ?"
"Yes, Chief, the specific-gravity age shows 1.206. I
took along the other gage, the Baume. and that showed
26. What do these figures mean "
"To begin with, get the objj.t of the test clearly in
mind. What do you test the brine for, anyway?"
"To find out whether it has enough salt or calcium
chloride in it or not."
"Yes, but couldn't you tell that in some other way?
Tell me how."
"I could take a graduated flask and draw off a certain
amount of the liquid, evaporate the water out of it and
weigh the salt it contained, but that would be a lot of
bother."
"Suppose, then, you put the same amount of salt into
the same quantity of water and weigh the mixture care-
fully, you would find that for a certain degree of saltness
the weight would be the same every time and for a
greater or less degree the weight would vary accordingly.
This method would not be convenient, either, because care
must be taken to get just the correct quantity each time
and weigh it carefully. By the way. did you ever think
of why they always use those jteculiar-shaped bottle- or
flasks, with long slender necks on which there are gradu-
ations, in the laboratories? The idea is to fill to a certain
mark in a slender part for accuracy, because a few drops
more or less will change the level in a slender tube a lot,
while if the mark were on the large body of the flask
a difference of considerable magnitude would hardly be
noticeable. This same feature applies to the hydrometer,
which will be referred to later.
"Now, suppose you used the same flask, but instead of
putting the fluid into it, you put certain weights inside
of it and put the flask into the brine. It would sink
to a certain depth, displacing an amount (measure) of
liquid exactly equal to the volume or measure of that part
of the flask which was submerged and in weight equal
.o the total weight of the flask and conteuts. The level
to which it settled could then be marked on its neck
so that it might be used again as a test gage for other
brine of the same density into which it would settle
io the same mark. (This is where the long slender neck
of the hydrometer enters in, as referred to before. As
the part is -lender, it would have to be submerged
to a greater extent to displace a small amount of liquid,
and the graduations would be farther apart anil more eas-
ily read.) This method would be more convenient than
measuring out a given quantity and weighing it, or evap-
orating it in the way you just spoke of. Then by a series
of tests you might construct a scale on the neck of the
flask, so that you would know the density or saltness of
the fluid by the depth to which the flask settled and
would know by that scale how much salt there was to a
cubic foot just as well as if you had gone to the trouble
of evaporating the water out. Tf, after getting your flask
nicely graduated for brine, you should put it into pure
distilled water it would be likely to sink 'head over heels'
unless the neck was very long. This is because the fresh
water is less dense and the same vessel would sink deeper
or entirely."
"Yes, Chief. I have always" understood that objects
which will sink in fresh-water streams or lakes will some-
times float in the ocean. So this is the same thing, is it?"
"That's flic idea. Will. Then if you were making a
hydrometer you would want a fresh-water mark on it as a
means of comparison. That's just what Baume, Twaddell,
Beck and others did in constructing an arbitrary scale.
The way Baume first arrived at his scale was, the in-
strument was submerged in water, by means of the mer-
cury placed in the bottom of the glass, to a certain point
which was marked zero. If the instrument was to be used
to determine the density or specific gravity of fluids
heavier than water, it would be loaded so that it would
sink in distilled water almost to the top of the tube, be-
cause with the same amount of weight it would not sink
so far into the heavier fluid, therefore the graduation was
downward from the zero mark made at the surface of the
water. The instrument was then put into a solution of
1 5 parts of salt and 85 parts of water. The point to which
it would sink in this solution was marked 15, the distance
between these two points was then divided into 15 equal
parts, and the graduation was continued beyond 15 in
equal divisions. This constitutes the Baume scale for
liquids of greater specific gravity than water. On the
other hand, if the instrument was to be used for fluids
lighter than water a different scale was used. Baume
used for the zero point the position of the instrument in
a solution of 10 parts of salt and 90 parts of water, and
for 10 its position in distilled water, and divided this dis-
tance into 10 deg., and continued the graduation to the
top of the scale.
"There is a tendency now to discard all arbitrary scales
in favor of those which read in terms of specific- gravity
without the necessity of interpolation. The Baume scale
in its time was a very important development, but since
the specific gravity of the common fluids lias now been
established so that the instruments marked with a scale
showing the specific gravity by direct reading are prefer-
able. It will be interesting for you to look up a table
showing by comparison the Baume scale and the specific-
gravity scale."
"Yes. Chief, such a scale does not mean much, to me at
least."
"The specific-gravity scale shows by direct reading the
weight of the fluid as compared with the same volume of
pure distilled wafer at 65 deg. That is, the brine in this
case is 1.20fi times as heavy as water (62.35 per cubic
foot), the brine would be 62.35 X 1-206 = 75.194 lb.
per cubic foot. Any reading of specific gravity multi-
plied by the weight of water per cubic foot will give the
weight per cubic foot of the fluid in question. The read-
ing on the Baume scale in so called degrees must be trans-
posed by reference to a table to become intelligible."
"The term specific gravity gets me twisted somehow,
Chief. See if I have it right. Gravity, or weight, refers
to the action of the law of gravitation acting on a given
454
POWER
Vol. 41, No. 13
substance. Then the word specific added makes the weight
refer to and compare specifically with some other recog-
nized substance, so that the specific gravity of a sub-
stance is its weight compared with distilled water, bulk
for bulk. Is that right. Chief?"
'"Yes The weight of an object as shown by the scales
is independent of its bulk or volume. Its density is its
weight per unit of volume (1 cu.ft. for example). Its
relative density, or specific gravity, is its weight per unit
of volume (as before) specifically compared to the weight
of the same volume of a predetermined standard (pure
distilled water at maximum density for heavy things is
generally used and hydrogen for gases)."
••Another thing puzzles me. Chief. If a body which
sinks is put into water it will displace a certain amount
of the water which, if allowed to overflow and is measured,
will occupy the same space as the body which has been put
into the water, but they do not weigh the same. In the
other case if the body placed in the water floats, the water
which is displaced by it will be of the same weight, while
the volume of water displaced will be equal to only that
part of the body which was immersed, yet the specific-
gravity of each is given in the table. How is that deter-
mined ?"
"The specific gravity of the body heavier or more
dense than water is obtained by sustaining some of its
weight, or that part of its weight greater than the weight
of the water displaced by it. by means of scales with the
proper weights on the opposite side: then in every case
the weights so required plus the weight of the water
displaced will equal the weight of the body being tested,
while the ratio of the weight of the body in air and in
the water is its specific gravity.
"Density is defined as "the ratio of mass to volume.' It
was considered worth while by the Internationa] Congress
of Physicists at Paris in 1900 to pass a resolution de-
fining this quality as stated above, because the term i> so
frequently misused by writers on scientific subjects. Den-
sit] and specific gravity are by no means the same, al-
though one is proportional to the other. The specific
gravity of any substance is denned as the ratio of its den-
sity to the density of water.
""This old problem may interest you. as it is along
the same lines : A canal aqueduct is capable of sustaining
ten tons per running foot, the structure filled with water
weighs .-even tons per foot, and a boat weighing four tons
per foot is to pass through the canal. The question i-.
will the structure sustain the weight when the boat is in
the canal?"
An interesting way of handling ashes was observed
during a visit among some small plants where the num-
ber of boilers did not warrant the use of conveying ma-
chinery.
In line plant, a part of which is shown in the sketch,
the yard level was below the boiler-room floor. To con-
vey the ashes to this level 6-in. terra cotta soil pipe was
laid as shown. The elbow at the extreme right was
blanked off and a 2-in. pipe inserted. Water for flush-
ing the ashes out of the pipe is admitted through this
line. In this plant water from the feed-pump discharge
was used.
The large pipe should be inclined considerably and
large clinkers should be broken before entering the tees.
How the Ashes Are Flushed to the Yard
By A. B. Morrison, Jr.
In handling liquids other than water with a centrifu-
gal pump it is necessary to study closely the characteris-
tics of the liquid to be pumped and its behavior under
similar operating conditions in order to estimate even
approximately what can be expected in the way of power
and speeds to produce certain results. A centrifugal
pump was used for handling crude oil, replacing a direct-
acting steam pump which had been used for the same ser-
vice. The results obtained were so much at variance
with what had been expected that some further tests were
made to ascertain wherein the difference lay, and as a re-
sult some interesting data were obtained.
The centrifugal pump was designed to deliver 1600
gal. per min. against a head of approximately <>0 lb., the
head being due almost entirely to the friction in a long
line of pipe, the static elevation being slight. The pump
was of the single-stage, horizontal split-casing type, di-
rect connected to a steam turbine running at approximate-
ly 2000 r.p.m. The guarantees as to head, capacity
and steam consumption were made on the basis of pump-
ing clear water. On the basis of such data as were a\ ail-
able to the customer, it was assumed that the friction of
the crude oil through the discharge pipe would be ap-
proximately the same as that of an equal amount of
water. It was. therefore, considered that the pump should
show the same efficiency, approximately, pumping oil as
water. The crude oil had a specific gravity compared to
water of 0.865 to 1.
A test was run on the outfit as installed, by measuring
the steam to the turbine with a steam-flow meter, the
oil by measuring the total amount taken from the tank
and dividing by the total minutes run to get. the avi
quantity pumped per minute, and the pressure by means
ages on the suction and discharge, correcting for the
difference in level between these gages and the center line
of the pump. The speed was recorded at frequent inter-
vals, so that a good record of the pump performance was
obtained. Allowing for possible errors in the readings and
giving the outfit the benefit of every doubt, the steam con-
sumption, as shown by two different tests, was so much
greater than that guaranteed that it was evident some-
thing was wrong. A test of the turbine and pump sep-
arately, the latter pumping water, showed that both met
March 30, 1915
POWER
455
their respective guarantees as to capacity and efficiency,
so there was no apparent reason why the combined outfit
should not give the results anticipated if the assumption
as to the power required for handling crude oil were cor-
rect.
To determine how much difference existed between
pumping crude oil and water a series of tests was run on a
smaller motor-driven pump, as it was not possible to run
the turbine outfit on anything but oil. The pump avail-
able for the tests was a small single-stage side-suction one
direct-connected to a three-phase motor. It was old and
not in good condition. The suction was under a slight
pressure and the discharge was into a tank, the pressure
on the discharge being varied by manipulating a valve. By
means of a float on the tank the average quantity pumped
in gallons per minute was determined for five-minute in-
tervals. Gages on the suction and discharge gave the
pressures. The gages on the suction were, apparently,
not accurate, so that the readings were not wholly relia-
ble. At the time the test was made no wattmeter was
available, so it was necessary to read the current and volt-
age in one phase only and assume an arbitrary constant
for efficiency and power factor in calculating the horse-
0 20 40 60 80 100 120 140
Percent of Rated Capacity in Gallons per Minute
Pump Pebfobmance with Water and with Cbude On
power. For this reason especially, the curves are not
correct, and it should be understood that the relative
brake horsepower, head and efficiency are approximate.
The general forms of the curves are correct. Since the
essential idea was to determine the relative behavior of the
water and the crude oil, it was considered that the tests
answered the purpose.
An inspection of the curves shows the marked increase
in the efficiency of the pump when handling water. The
brake li rsepower was approximately the same in b ith
cases, though the weight of the oil pumped was consider-
ably less and the head generated by the pump less.
Through the pump the velocity was very high as com-
pared wiH\ that in an ordinary line of pipe, and this
high velocity of the oil caused, on account of the viscosity
of the latter, the loss in efficiency. This is shown by the
head curve. Theoretically, the head in feet should be
the same regardless of the liquid pumped, but part of the
head generated is lost in the pump because of the greater
work required to pet the oil through the impeller and
casing.
One fact not shown in the curves, but brought out in
the operation of the large pump, is that the assumption
that the pipe friction is about the same for crude oil and
water at the usual pipe velocities is quite correct. The
crude oil was pumped through the pipe line in the calcu-
lated and desired quantity, and while the required pres-
sure, measured in feet, was slightly greater than that for
water, it did not differ from that estimated enough to oc-
casion any trouble. When the velocity is as high, however,
as is necessary to get the liquid through a centrifugal
pump, the greater viscosity of the oil causes the very
marked increase in the friction and power required.
In view of the results obtained with the outfit described,
it is a question whether it would not have been better to
install a compound direct-acting steam pump. The con-
ditions were not favorable for a steam turbine, as the
steam pressure was only 70 lb. gage and the exhaust was
to the atmosphere. The pump also ran somewhat slower
than the most economical point of the turbine. There is,
of course, the argument for greater simplicity in the tur-
bine-driven outfit, both in prime mover and pump, but
the ordinary direct-acting steam pump is not likely to
give trouble and in the present case the steam consumption
would have been no greater and the first cost probably less.
SftesiSiffi^Tuas'lbaim© ©K*a^© ft<o>v §&<&<sH
Mills*
The Carpenter Steel Co.. of Reading, Penn., furnishes an
interesting example of how increased power can be obtained,
while reducing the fuel bill and the number of boilers in
service. This plant is, moreover, notable as being the first
in America, and the second in the world, to apply the steam
turbine to the driving of rolling mills through the medium
of mechanical speed-reducing gears.
The company does a general merchant trade, consisting
of high-grade tool steels, projectiles and special steels for
such uses as safety-razor blades, springs, and the like. The
two-stand, 18-in., three-high roughing mill now driven by
turbine was formerly driven by a 36x36-in. simple slide-valve
engine, operated condensing, while the 10-in. and S-in. finish-
ing mills were driven by belt from a cross-compound, 22&
40x4S-in. engine, exhausting into a jet condenser, which
gave a vacuum varying from IS to 24 in.
Besides the main power units for the mill, there were
in the immediate vicinity several service and boiler-feed
pumps and air compressors, the exhaust of which was par-
tially utilized in an open feed-water heater, the surplus
escaping to the atmosphere. While no data were obtained
regarding the steam consumption when using this equipment,
it was necessary that five boilers of a nominal total rating
of 1000 hp. be operated continuously.
With a view to reducing power costs, several alternatives
were considered. The simple engine driving the roughing
mill could have been replaced by a modern compound engine
and a modern high-vacuum central condensing plant for the
two engines put in. But because of the fluctuations of load
on the engines and the small average horsepower required,
also because of the first cost of the equipment and the
moderate economy, this scheme was not adopted.
The second alternative was the installation of a low-
pressure turbo-generator operating on the exhaust of the
compound engine to supply current to a motor driving the
roughing mill. This did not appear attractive, as it involved
a large investment in turbine, generator, switchboard, trans-
mission lines, motor, starters etc., and nearly all the current
produced would have been consumed by the roughing mill.
The third plan consid-?red, and the one ultimately
adopted, was the installation of a low-pressure turbine to
drive the roughing mill. This proposal involved the use of
speed-reducing gears, a new expedient for this work, but
one which had already been satisfactorily used by James
Dunlap & Co., Calderbank Steel Works, near Glasgow, Scot-
land, where a mixed-pressure turbine, developing 750 hp.,
drives a three-high, 2S-in. plate mill. The speed reduction
of the Calderbank mill is made in two steps — first from 2000
to 375 r.p.m. and then to 70, by means of double-helical gears
of the rigid-frame type.
As compared to the 15 to 20 per cent, loss of energy in
booklet issued by the De Laval Steam Turbine Co.
456
POWER
Yol. 41, Xo. 13
the electrical method of driving, the gear loss is not more
than 1% to 2 per cent., besides which it costs less, occupies
much less space, is simpler and requires less attention.
For the operation of the roughing rolls at the Carpenter
steel plant, an average of about 350 hp. was required, at a
speed varying from 60 to 100 r.p.m., while for the greatest
efficiency and simplicity of construction a turbine of this
capacity should run at about 5000 r.p.m. To secure the
reduction of 50 to 1, a two-step reduction gear was adopted,
the gear and turbine being mounted on one base plate and
the complete unit so located that the shaft of the slow-speed
gear is in line with the shaft of the engine which the turbine
replaces. The 26-ft. engine flywheel, weighing 47,600 lb. and
the engine shaft and bearings were left in place. In order
to avoid interruption of work while making the change and
also to provide against any possible interruption of service
thereafter, the engine was left intact and only the connecting-
rod removed, a distance piece, which serves also as one of the
flanges of the flexible coupling on the low-speed gear shaft,
being bolted onto the crank disk. After the turbine was
installed it was thus possible to operate it without load
in order to try out the installation, during which period the
engine continued to drive the mill and practically no time
was lost in changing from engine to turbine drive.
The turbine, which is of the mixed-flow type, was built
by the De Laval Steam Turbine Co., and contains eight pres-
sure stages, the first pressure stage consisting of two velocity
stages. The low-pressure steam, that is, the exhaust steam
from the engine, is admitted at the third pressure stage
and expands through the remaining stages to exhaust pres-
■sure.
The turbine is designed to operate under four different
steam conditions: When receiving engine exhaust at a pres-
sure of 3-lb. gage, and when exhausting into a vacuum of
27 in., it is to develop 350 hp. at speeds corresponding to 70
to 100 r.p.m. of the mill shaft, under which condition it is
guaranteed to take not more than 26 lb. of steam per brake
horsepower per hour, as measured at the end of the second
gear reduction. It is also to be able to carry the normal
load of 350 hp. "when using steam at 120 lb. pressure gage
and exhausting to a 27-in. vacuum, under "which conditions it
is guaranteed to take not more than 17% lb. of steam per
brake horsepower per hour. 'When receiving both high- and
low-pressure steam and exhausting to vacuum, the turbine
is to be able to carry 600 b. hp. continuously. It is also to
be able to carry a load of 600 hp. on high-pressure steam
only, as when the compound engine is not running. Under
these conditions it is guaranteed to take not more than 15.7
lb. of steam per brake horsepower per hour.
The turbine is also to be able to carry normal load non-
condensing when receiving steam at 120 lb. and exhausting
to atmosphere, making it possible to inspect or repair the
condenser or circulating pump without interfering with the
operation of the mill.
The roughing mill is three-high and consists of two
stands of lS-in. rolls. It is manually operated, two men being
employed on each stand. The reduction of a 4x4-in. billet,
17.6 in. long, weighing SO lb., to an oval 134 in. wide is per-
formed in thirteen passes, occupying 41g seconds.
Owing to the fact that the finishing mill cannot take
high-carbon steel as fast as the roughing mill can supply it,
only one billet is usually in the latter at one time, but when
rolling low-carbon steel, two billets are in at once. "When
handling one billet no speed variation is perceptible on the
tachometer, which is permanently attached to the 600-r.p.m.
shaft, while when handling two billets the speed drops about
2 per cent. The fact that there is no drop of speed with
one billet in the mill shows that the heavy flywheel is not
required for power storage under such conditions. By setting
the governor for a greater drop in speed before the high-
pressure valve opens, the power-storage capacity of the fly-
wheel can be utilized and unnecessary use of high-pressure
steam avoided.
The compound engine, operating noncondensing, ordinarily
supplies steam to the turbine under 3 to 3*i lb. back pressure,
the pressure being regulated by a multiport safety exhaust
outlet valve. The roughing mill, however, is not required at
certain times, the steel being taken directly to the finishing
mill, at which times the valves between the engine exhaust
and the turbine, and between the turbine exhaust and the
condenser can be closed and the valve between the engine
exhaust and the condenser opened, permitting the engine to
operate condensing.
In the low-pressure supply line to the turbine is placed
a receiver steam separator. To insure dry steam, a coil of
1-in. copper pipe, inserted in the 12 ft. of 10-in. pipe between
the separator and the turbine, is kept filled with live steam
and drained by a steam trap. Adjacent to the low-pressure
throttle valve of the turbine is a multiport flow valve, de-
signed to prevent the vacuum from packing up from the
condenser through the turbine into the engine exhaust line.
Without this valve there is always a possibility of air being
drawn in through leaks in the exhaust line and through
piston-rod and valve-stem packings of the engine at times
when there is little or no exhaust steam available. Such
air would interfere with the operation of the condenser.
The condenser, which is of the multijet type, is located
just outside of the engine room and is protected by a 10-in.
multiport atmospheric relief valve. With a water tempera-
ture of 72 deg. F., the condenser maintains a vacuum of 2S.2
in. with the barometer at 29.78 in. As there was a surplus
of exhaust steam for operating the circulating pumps, and
also because of the desirability of a simple, reliable con-
denser, this type was considered best.
The circulating water for the condenser is supplied by a
centrifugal pump driven by a mixed-flow geared turbine of
the velocity-stage type with two sets of nozzles and designed
to operate either with steam at 120-lb. gage or with steam
at 3-lb. gage, exhausting to a 27-in. vacuum. It exhausts
through a 10-in. pipe to the same condenser that serves the
main unit. The speed-reducing gears permit both turbine
and pump to run at the best speeds for economy, viz., 5000
r.p.m. for the former and 1500 r.p.m. for the latter. The
turbine can be started noncondensing and will carry full
load with high-pressure steam alone, thus providing both for
starting the pump before the condenser is in operation and
for carrying its full load without taking low-pressure steam.
Surplus exhaust steam not used by either turbine passes to
the open-feed water heater, which also receive the exhaust
from pumps, air compressors, etc
The cost of the installation, consisting of the turbine,
reduction gear, condenser, piping, circulating pump, valves,
etc., erected complete, was not far from $25,000, and owing
to the better economy secured through its use, it has been
possible to reduce the boilers in operation from 1000 hp. to
about 600 hp. This indicates a saving approaching $15,000
per year.
C^uas© of ftlhe "Ssiia IEM©fi>©8
The cause of the low water which allowed the boiler
aboard the U. S. armored cruiser "San Diego" to become
overheated and explode on Jan. 21, it is learned, was the top
of a bucket strainer in the feed tank came off, dropping to
the bottom of the strainer, partly closing the opening of the
suction pipe to the feed pumps. One-half of the supply of
feed water was thus shut off and as water was being carried
rather low and the engines running at full power, it was im-
possible to get sufficient water to all the boilers, with the
result that five boilers were badly overheated, when the ex-
plosion occurred.
The "San Diego" (originally the "California," built in
1907) is the flagship of the Pacific fleet that had just com-
pleted a four-hour speed trial. Her triple-expansion engines
indicate 30,000 hp., and are capable of developing a speed of
22.5 knots. The boilers are of the B. & W. marine type
(forced draft), with 1592 sq.ft. of grate surface, and 70,000
sq.ft. of heating surface. She carried a crew of S22 men,
nine of whom were killed as a result of the explosion. — A. P.
Connor, Washington, D. C.
F©s°ea^Ea Trade ©p>p©irtUa3aii£a@§
Brass and phosphor bronze wire Xo. 15.67S
Centrifugal pumps No. 13.714
Concrete mixers Xo. 15,744
Electric motor Xo. 15,699
General agency Xo. 15,691
General agency Xo. 15,740
Iron and steel No. 15,757
Machinery and tools Xo. 15,743
Machinery Xo. 15,727
River dredge and pumping plant Xo. 15,675
Steel forgings, castings, etc Xo. 13.673
Sugar machinery Xo. 15,701
Tools and technical appliances Xo. 15,692
Vacuum cleaners Xo. 13.71S
Vacuum cleaners Xo. 15.750
Wire, iron and steel bars, paint colors, etc No. 15.677
Wire machinerv Xo. 15,690
Wrought-iron fittings Xo. 15.676
Addresses and detailed information may be obtained from
the Bureau of Manufactures, Washington, D. C, and its
branch offices, as follows: Xew York, Room 409, U. S. Custom-
house; Boston. 752 Oliver Bldg.; Chicago, 629 Federal Bldg.:
St. Louis_ 402 Third Xational Bank Bldg.; Atlanta, 521 Post
Office Bldg.: Xew Orleans, 1020 Hibernia Bank Bldg.: San
Francisco, 310 U. S. Customhouse; Seattle, 922 Alaska Bldg.
March 30. 1915
POWER
457
Digested by A. L. I
^©cnsn
STREET
defendant's discharging- the noxious fumes through a high
chimney, and that it is no defense to such a suit that the
compressed-air method is in common use.
Fires Set By Traction Eneines — One operating a steam
roller or traction engine along a street or highway must
use that degree of care to avoid setting fire to adjoining
property which an ordinarily careful person would use under
the same circumstances. And if a law or ordinance requires
such engines to be equipped with spark arresters, the owner
is liable for loss directly attributable to failure to comply
with the requirement. These rules were lately announced
by the Delaware Superior Court in the case of Cecil vs.
Mundy, 92 "Atlantic Reporter" S50.
Classification of Fuel-Gas Rates — -A public-service corpora-
tion engaged in furnishing gas for heating, lighting and
power purposes may lawfully classify its rates according to
the nature of the service afforded, as well as the quantity
of gas furnished, if the classification is not unfair or dis-
criminatory against other classes of consumers. The West
Virginia Supreme Court of Appeals has just handed down this
decision in the case of Elk Hotel Co. vs. United Fuel Gas Co.,
80 "Southeastern Reporter," 922. But the court holds that
the same rate and service must be offered alike to all con-
sumers similarly situated and provided with the same char-
acter of equipment.
Impairment of Franchise Rights — After a power company
has acquired a right to use streets and highways for the
maintenance of transmission lines under existing constitu-
tional and statutory provisions, the right cannot be impaired
by a subsequent constitutional amendment. Hence, the pro-
vision incorporated into the Michigan constitution in 1909,
to the effect that public-service corporations shall not be
permitted to use the streets of a city without obtaining a
franchise from the city, cannot be deemed to impair a pre-
viously acquired right to maintain a line along certain streets.
(Michigan Supreme Court, City of Lansing vs. Michigan
Power Co., 150 "Northwestern Reporter," 250).
Washroom Law Sustained — In 1913 the Illinois Legislature
enacted a law which, in effect, requires that owners and oper-
ators of coal mines, steel mills, foundries, machine shops,
etc., provide adequate washroom facilities to enable employees
whose work in such employments causes their persons or
clothing to be covered with grime, dirt or perspiration to
such an extent as to render their remaining in that condition
unhealthful or offensive to persons with whom they come in
contact in leaving their work, to change their clothing and
wash before leaving. In the case of People vr>. Solomon,
which was recently before the Illinois Supreme Court, the
validity of this regulation is upheld. (106 "Northeastern Re-
porter," 45S.) Doubtless it will be construed as extending
to the employment of stationary engineers and firemen in
the employments covered by the law. In fact, the decision
seems to hold that it covers all employments where "em-
ployees become covered with grease, smoke, dust, grime and
perspiration" to the extent that their remaining in that con-
dition would be unhealthful or offensive to the public.
The Engineer as an Kxnert Witness — The qualifications of
an engineer to testify as to the availability of means to pre-
vent injury to adjoining property in the cleaning of locomo-
tive boilers were under consideration recently before the
Pennsylvania Supreme Court in the case of Vile vs. Pennsyl-
vania R.R. Co. (91 "Atlantic Reporter," 1049). In this case
the plaintiff, an occupant of land adjacent to the defendant's
premises, recovered judgment for injury to the land through
the fact that smoke, soot, ashes, etc., were cast upon it in
the defendant's process of cleaning its locomotive boilers by
means of compressed air. A consulting engineer, who testi-
fied in the plaintiff's behalf, admitted that he had had no
experience with locomotive boilers, but that they presented
no problems with respect to such processes that do not
equally apply to other boilers, and that he had made a special
study of power and combustion, and had had experience in
doing away with the evils of smoke, etc. The Supreme Court
holds that he sufficiently qualified himself as an expert to
enable him to testify that in such cases as this one, deposits
of soot on premises near those upon which boilers are cleaned
can be avoided by using brushes instead of blowers and by
washing the smoke to remove injurious impurities. The court
finds that this method has been found to have been effectively
used by railroads and in stationary plants for 70 years, and
that the compressed-air method was adopted merely to save
t me and expense. And it is further found that the damage
which the plaintiff sustained could have been avoided by the
Edward Wegmann and A. G. Hillberg have taken offices
in the South Perry Building, New York City, to engage as
consulting hydraulic engineers on water-works, water-power
developments, sewer systems, irrigation and drainage proj-
ects. Mr. Wegmann was for more than 30 years connected
with the construction of the Croton Water-Works. He was
the last chief engineer of the Aqueduct Commissioners and
subsequently for four years consulting engineer of the De-
partment of Water Supply, Gas and Electricity. He is well
known through his books — "Design and Construction of
Dams" and "The Water Supply of the City of New York."
Mr. Hillberg has been connected with large hydro-electric
developments, notably the Mississippi River Power Co.'s plant
at Keokuk, Iowa. For the past two years he has been asso-
ciate editor of "Engineering Record," in charge of hydraulics.
EHGHMEEEOHG AFFAURS
The Illinois Section of the American Water Works Asso-
ciation, succeeding the Illinois Water Supply Association, held
its seventh annual meeting at the University of Illinois, Cham-
paign-Urbana, 111., Mar. 9 to 11. The program included the
following papers: "The Design and Operation of Intermit-
tently Operated Water Purification Plants," E. B. Black, con-
sulting engineer, Kansas City, Mo.; "Wash Water Salvage at
Champaign and Urbana," H. E. Babbitt, instructor in Uni-
versity of Illinois; "Relation Between Bacteriological Stand-
ards and Vital Statistics at Hannibal. Mo.," w. F. Monfort, con-
sulting chemist, St. Louis, Mo.; "Loss of Head on Strainers of
Water Filters," Langdon Pearse, division engineer, sanitary
district of Chicago; "Experiences in Rebuilding and Rein
forcing a Water Works System," (). T. Smith', superintendent
and manager. Water Works Co., Freeport. 111.; "The New Har-
risburg (111.) Filter Plant." L. F. Payne and Glen W. Bass,
Central Illinois Public Service Co.; "Soft Water" (Illustrated),
Cass L. Kennicott, vice-president and general manager, The
Kennicott Co., Chicago; "Water Works Improvements at
Springfield, 111." (Illustrated), W. .1. Spaulding, commissioner
of public property, Springfield, 111.; "Coal Mining Operations"
(Moving Pictures), R. Y. Williams, director Miners' and Me-
chanics' Institute, University of Illinois; "Coal Resources of
the Danville Area," F. H. Kay, assistant state geologist,
Illinois; "Investigation of Artesian Water Supplies in the
Chicago Area" (Illustrated), Frank De Wolf, director Illinois
State Geological Survey; "The New Filtration Plant at De-
catur, 111." (Illustrated), Harry Ruthrauff, commissioner of
public property, Decatur, 111.; "The New Filtration Plant at
Quincy, 111. (Illustrated), W. R. Gelston, superintendent Citi-
zens Water Works Co., Quincy, 111.; "Kinks in the Control of
Hypochlorite at Denver." W. W. DeBerard, western editor,
"Engineering Record," Chicago; "River Sand as a Filter
Medium," L. A. Fritze, city chemist, Moline, 111.; "Choice of
Alloys in Connection with AVater Works Equipment," Horace
Carpenter, engineer, Sanitary District of Chicago; "The Prac-
tical Value of Publicity to the Water Works Man," S. C. Had-
den. associate editor, "Engineering and Contracting," Chicago;
"Treatment of Water for Locomotive Use," W. A. Pownall,
water engineer, Wabash Railway, Decatur, 111.; "The Possi-
bilities of Improved Water from Deep Wells in Northern Illi-
nois." C. B Williams, hydraulic and sanitary engineer, Chi-
cago; "Water Supply of Longview, Texas," Paul E. Green,
civil and sanitary engineer, Chicago; "Arsenic in Filter Alum,"
Edward Barton and A. N. Bennett, state water survey, Uni-
versity of Illinois; "Some Features of the Ontario Statutes
and their Administration Affecting Water Supply and Sewer-
age," F. A. Dallyn, provincial sanitary engineer, Toronto.
Canada: "The State Public Utilities Commission of Illinois and
Water Works," W. A. Shaw, member Public Utilities Commis-
sion, Springfield, 111.; "State Regulation of Municipally Owned
Plants," C. M. Larson, chief engineer, Railroad Commission of
Wisconsin; "The Illinois Utilities Commission and the Wa-
ter Works Companies," C. G. Bennett, mechanical engineer,
Illinois Utilities Commission, Springfield; "The Application of
the Theories of Regulation to the Management of Utilities."
Douglas A. Graham, principal assistant engineer, Dabney H
Maury, Chicago; "Economic Waste Aspects of Water Works
45S
POWE R
Vol. 41, No. 13
Operation," Ralph E. Heilman, assistant professor of Eco-
nomics, University of Illinois: "Ancient and Modern Account-
ing for Utilities." Edward A. Pratt, president Edward A. Pratt
Audit Co., Peoria, 111.: "Water Waste Prevention by Individual
Meter vs. District Meters," R. O. Wynne-Roberts, consulting
engineer, Regina, Sask.. Canada. The exhibits of the Associ-
ates were shown in Engineering Hall.
COX'S COMMERCIAL CALCULATOR. Bv Edward L. Cox.
Published bv Funk & Wagnalls Co.. New York. 7x11 in.;
203 pages; cloth. Price, $10.
A collection of tables, from which the product of any two
numbers whose sum does not exceed 202,000 can be found.
The use of the tables is briefly explained and illustrated.
Two key numbers must be obtained from the numbers to
be multiplied, by the use of a simple formula. Each key
number forms an unusual index to the table numbers required,
in that the digits must be taken in order from right to left
to find the correct page, column, section and line. The prod-
uct desired is the difference of these two table numbers. The
tables themselves are conveniently arranged and the book is
valuable for commercial and scientific purposes in which
products up to ten billion, accurate to the smallest unit, are
essential.
GEARING. Bv A. E. Ingham. Published by D. Van Xostrand
Co., New York. 5y..xSy> in.; 181 pages; cloth. Price,
$2.50
To the outsider the acquiring of practical gearing knowl-
edge has been somewhat of a task. In one book he may find
a complicated discussion of gearing principles; another may
give him the manufacturing methods, while he must consult
a third to find practical methods of design. Mr. Ingham has
endeavored in the one book to cover the whole broad field of
gearing. Nearly half of the 1S1 pages relate to spur gears,
but in this section is stated the theory of the involute and
cycloidal curves, which is later applied to the bevel, worm,
spiral and helical gears.
The reader is given methods of drawing gear-teeth curves,
such as the Brown & Sharpe single curve and the Grant odon-
tograph; is shown how to calculate speed ratios for simple
and compound gearing; and is informed regarding the ma-
terials and proportions of gears for the efficient transmission
of power. The diametral, circular and metric systems of
gear pitches are described. Numerous working drawings,
cross-sections as a rule, accompany the design directions,
while the manufacture and application of the various gears
are illustrated by photographs. Formulas are given so that
the reader may understand and pass through all the steps
necessary to obtain the complete dimensions, but the nu-
merous curves and tables, demonstrated by numerical ex-
amples, afford many short cuts. In general, Mr. Ingham's
work offers a simple and adequate presentation of the inform-
ation required in the design and application of gearing.
OXY-ACETYLEXE WELDING AXP CUTTING. By Calvin F.
Swingle. Frederick J. Drake & Co., Chicago, 111. Cloth;
190 pages, 4Vlx6% in.; 76 illustrations. Price, $1.
HAXDBOOK OF MACHIXE SHOP MANAGEMENT. By John
H. Van Deventer. McGraw-Hill Book Co., Inc., New
York. Leather; 374 pages, 4x7 in.; 244 illustrations. Price,
$2.50.
ELEMENTARY ELECTRICITY AND MAGNETISM. By W. S.
Franklin and Barry MacNutt. The Macmillan Co., New
York. Cloth; 174 pages, 434x73i in.: 152 illustrations.
Price, $1.25.
ADVANCED THEORY OF ELECTRICITY AND MAGNETISM.
By W. S. Franklin and Barry MacNutt. The Macmillan
Co., New York. Cloth; 300 pages, 53ixS9i in.; 217 illus-
trations. Price, $2.
SANITARY REFRIGERATION AND ICE MAKING. By J. J.
Cosgrove. Technical Book Publishing Co.. Philadelphia,
Penn. Cloth; 331 pages, 5y>xSyi in.; 103 illustrations;
tables. Price. $3.50
PREVENTING LOSSES IX FACTORY POWER PLAXTS. By
David Moffat Myers. The Engineering Magazine, New
York. Cloth; 560 pages, 5x7*2 in.; 6S illustrations, includ-
ing several plates. Price, $3.
V
Antlmold and Autilmg Varnish for Books — The following
ingredients make a varnish that has been found very useful
in protecting books from mold and from roaches: Bichloride
•jf mercury, 2 parts; orange shellac, 20 parts: oil of tur-
pentine, 250 parts, and the balance up to 1000 parts, 95 per
cent, ethyl alcohol. — "The Canal Record," Dec. 16, 1914.
Elliott Co., 6910 Susquehanna St., Pittsburgh, Penn. Bul-
letin G. Steam traps. Illustrated, 12 pp., 6%xl0 in.
The Tracy Engineering Co., San Francisco, Calif. Catalog
No. 10. Steam purifier. Illustrated, 20 pp., Cx9» in.
The Blaisdell Machinery Co., Bradford, Penn. Loose Leaf
Catalog. Air compressors, vacuum cleaners. Illustrated, 6x9
in.
Semet-Solvay Co., Syracuse, N. Y. Pamphlet. Solvay
757c Calcium Chloride for refrigeration. Illustrated, 16 pp.,
4x9 in.
B. F. Sturtevant Co., Hyde Park, Mass. Bulletin No. 206.
Generating sets with vertical engines. Illustrated, 20 pp..
6%x9 in.
Lunkenheimer Co., Cincinnati, Ohio. Booklet. "Fer-
renewo" valves. Illustrated, 10 pp., 3V2x6 in. Booklet. "Clip"
valves. Illustrated, 10 pp., 3%x6 in.
The Bristol Co., Waterbury, Conn. Bulletin Nov 192.
Bristol's long-distance electric transmitting and recording
system. Illustrated, S pp., Sxl0}2 in.
Chicago Pneumatic Tool Co., Chicago, 111. Bulletin No.
E-35. Universal electric drills. Illustrated, 8 pp., 6x9 in.
Form No. 212. Boyer riveting hammer. Illust.ated.
Harrison Safety Boiler Works. Philadelphia, Penn. Coch-
rane Engineering Leaflet No. 17. "Reducing Boiler-Room
Costs by Heating and Softening the Feed Water." Illus-
trated, 20 pp., 6x9 in.
Buffalo Forge Co., Buffalo. X. Y. Catalog No. 200.
Planoidal Fans. Illustrated, 4x pp., 6x9 in. Catalog No. 201.
Niagara conoidal fans. Illustrated, 64 pp., 6x9 in. Bulletin
No. 1S2-E. Electric fans for blowing, ventilating, cooling,
drying. Illustrated, 32 pp., 6x9 in.
Charles T. Main, engineer, Boston, Mass., is distributing
a handsomely printed volume of halftone illustrations of in-
dustrial plants of his design. This follows a similar work
issued some time since, and is inscribed "Industrial Plants,
Vol. 2." Prospective builders of anything from cotton mills
to central stations will find in it worth-while suggestions.
kusiibjes
HTEM^
The New River Co., equipment sales department, Mac-
donald. West Virginia, is sending out a list of second-hand
power plant equipment, quoting prices and terms.
Harry J. Ernst, advertising manager of the D. T. Williams
Valve Co., Cincinnati, Ohio, has been elected treasurer of
the company, succeeding R. E. Mullane, recently elected
president.
The Link Belt Co., Chicago, 111., is sending out bulletins
descriptive of the Wendell centrifugal coal drier, and the
Link-Belt electric hoist. Both bulletins show illustrations
of the equipment and go into details of construction. Copies
are sent on request.
The Chicago office of the Terry Steam Turbine Co., Hare-
ford, Conn., is now in charge of A. W. de Revere, located
in the Peoples Gas Building. This company has also opened
an office in the Michigan Trust Bldg., Grand Rapids, Mich.,
in charge of A. L. Searles.
The Sprague Electric Works of General Electric Co. has
recently opened a branch sales office in Cleveland, Ohio.
It will be in charge of Frank H. Hiil. manager, who also has
charge of the Pittsburgh office. The Cleveland office will
be located in the Illuminating Building.
The sales of Sarco steam traps, Sarco vacuum valves,
and Sarco temperature regulators have shown such substan-
tial continued increases during the past half year, that the
Sarco Engineering Co. of New York has moved its offices
into larger quarters in the new South Ferry Building, 1
State St.
A very interesting booklet has just been published by
the Murray Specialty Mfg. Co.. 55 West Woodbridge St.,
Detroit, on "Boiler Feed — How To Regulate It." It's a 32
page booklet describing the apparatus in detail and contain-
ing many clear and instructive illustrations. Testimonial
letters and installation details are also given. A request
brings a copy.
The Harvard Medical School has recently given an order
to the Builders Iron Foundry, Providence, R. I., for two extra
heavy meter tubes for boiler feed service. This institution
already has two Venturi meters on its heater conservation
system and six Venturi meters for brine measurement. M. L.
Bayard & Co., of Philadelphia, have recently placed an order
for 36 double dial indicating instruments to be used in
connection with effluent controllers at the Cleveland filtration
plant.
The Southwark Foundry & Machine Co., Philadelphia,
Penn., has secured the exclusive United States license to manu-
facture the Harris valveless engine, Diesel principle, which
will hereafter be known as the Southwark-Harris valveless
engine. The engine will be built in sizes from 75 b.bp. to
1000 b.hp. Leonard B. Harris, the inventor of the Harris
valveless engine will be with the company as consulting
engineer and naval architect, and J. P. Johnston will be in
charge of oil engine sales.
.,,/ft^r^
Vol. n
POWER
NEW YORK, APRIL 6, L915
111 1
Xn. 11
-THne Sword of Dammocles-
CREEPY, EH? No need to be if you KNOW your work. Merely a matter
of carrying mental voltage enough to hold that meat-ax in place. Even tho'
your job is a horseshoe magnet, yet— LUCK won't do. Soon another nick will appear
on that handle, recording your demise if you have nothing on your mind but your
hair. GET BUSY. Put some "JUICE" under your hat. And begin today. NOW!
too
P U W E S
Vol. 41. Xo. 14
mtimrf anndl Vemitlnlatlainitf System of
ri©Mn Oggyr
By W. L. Durj
SYNOPSIS — Modem demands for comfort and
convenience in the heating and ventilation of fac-
tory buildings have far outrun tli 3 relatively simple
requirements of former years. An interesting ex-
ample of modern tendencies is found in the equip-
ment of a new factor;/ erected for the American
Cigar Co.
The new building of the American Cigar Co., Garfield.
N. J., covers an area of 15,000 sq.ft.; it is five stories
high and has a floor area of 50,000 sq.ft. It is vised ex-
clusively for the manufacture of cigars and about 1000
persons are employed.
The power plant, Fig. 1. is located in the basement.
with natural light for the engine room and a convenient
arrangement for handling the coal and ashes.
The boiler room is equipped with two 75-hp. horizontal
return-tubular boilers arranged in a battery. While 125
lb. pressure is carried, the boilers are built to withstand
150 lb. The boiler furnaces are equipped with bridge-
wall dampers and ducts leading to the rear of the setting,
so that if it is desired later to increase the output by
the addition of forced draft, no changes to the setting will
be necessary.
The water for the boilers is taken from a driven well in
the pump room. Two 4:L£x2%x4-in. duplex, outside-
packed plunger pumps are so connected that either one
can be used to pump water from the well to the feed-
water heater, to the boilers direct, or from the feed-
water heater to the boilers. The steam piping is arranged
to control the pumps by throttle valves when pump-
ing from the feed-water heater to the boilers, or by means
of a float in the £ l-water heater when pumping from
the well to the heater. This arrangement permits of one
pump being used to handle makeup water to the feed-
water heater under automatic control, the other to be
used as a boiler-feed pump; in case of a breakdown to
either pump, water can be fed direct to the boilers by the
other.
A hydraulic damper regulator is used in connection
h itli a balanced damper in the main smoke flue. If forced
draft is installed this will also be used to operate a bal-
anced valve in the steam connection to the forced-draft
fan, permitting automatic control.
Bituminous coal is burned in the boilers. It is stored
111 a pocket adjacent to the boiler room, the coal being
supplied from a driveway overhead; The ashes are re-
nioved by an overhead trolley which discharges directly to
the driveway.
Fig. 1. Partial View of the Exgixe Room
The engine room is equipped with a 10xl2-in. high-
speed engine directly connected to a three-wire, direct-
current 110-volt generator. It was the first intention
to use a four-valve engine, but after going into the situa-
tion it was found that engine economy was of value only
during the summer months when the load was the lightest,
and that the saving would not be sufficient to warrant the
increased cost of both engine and generator. The increased
cos! of the generator would be almost as much as that
of the engine, due to the lower speed of this type of en-
gine. \~o breakdown service or extra unit was installed,
10" £f" "' ,r /6' ft-
18' -i9" 20' -\
O IP' B"a
-7-
J8"a h _JQla-J2ii-J657i?
7? ^
PLAN
Pig. 2. Plan amj Elevatiom or ihb Hot-Aib Ducts
MAIN HOT BLAST DUCT
April 6, 1915
r o w e i;
■lui
since the character of this factory did not seem to war-
rant the extra expenditure.
Exhaust steam from the engine and pumps passes to a
feed-water heater and is then used for heating hot-blast
roils, with provision for using live steam from the boilers
through a double set of reducing valves.
The building is heated by means of a hot-blast system
supplemented by a few coils and radiators. The air in
entering passes first through a tempering coil, an air
washer, and a reheater to the intake of the supply fan.
From the supply fan it is distributed by a main riser
with two branch ducts on each Hour. Fig. 2 is a plan
and elevation of the hot-air duets. Fig. 3 is a plan \ iew
of the engine, boiler and air-washing rooms.
Fig. 3. Plan of Engine, Boilee and Air-Washing
Boons
The tempering coil consists of two groups of 60-in. cast-
iron heaters set on 5-in. centers. Each group contains
20 sections, making a total of 640 sq.ft. The coils raise
the air to a certain necessary minimum temperature, as
later described, before passing to the air washer.
The air washer consists of a metal spray chamber
through which the air is drawn. Under the chamber is
a tank which is kept filled with water. A centrifugal
pump driven by a directly connected motor draws water
from this tank and forces it through the spray nozzles.
The nozzles, of which there are approximately seventy,
are uniformly distributed over the cross-section of the
washer, so that this chamber is tilled with a tine mist
so dense that it is impossible for the air to carry any dirt
through it without the latter becoming wet and heavy.
At the end through which the air leaves the spray cham
ber is placed a set of eliminator plates, which extract ah
the water and dirt. These plate are kept Hooded, so
that dirt is washed into the settling tank.
This apparatus is provided with an arrangement for
automatically controlling the humidity. The spray water
is heated when the humidity is too low in order to in-
crease the evaporation] this heating is controlled by a
Fig. 4. Showing Air Ducts and Steam Coils on the
Top Floor
thermostat placed in the air ductJeading away from the
apparatus. While one of the functions of an air washer
s to remove dust and floating solid matter from the air he-
fore entering the rooms to be heated, the principal reason
for installing one in this factory is for humidifying the
air, and in order to give the best possible conditions
for the manufacture of cigars it was decided to maintain
a humidity of at leasl 65 per cent, at all times.
For the proper operation of tin's apparatus the temper-
ature of the entering air should fulfill two conditions— it
must be not less than 32 deg. F. to avoid danger of freez-
ing the water in the washer, and it should have such a
temperature that when saturated, as it is when leaving
the washer, it will carry such a moisture content as will
give it, at the desired room temperature, a relative humid-
ity of 65 per cent.
The heating stacks consist of four groups of 60-in.
cast-iron heaters. Each group contains 22 sections, mak-
ing a total of 140S sq.ft.
The fan is a 54-in. diameter multivane, and it has
a capacity of 25,000 cu.ft. of air per minute against a
pressure of 1 in. of water. It is driven by a directly
connected 10-hp. engine. The reason for using an engine
in preference to a motor is that in case of a breakdown to
the engine generator se1 the building could still be kepi
warm ami work would not have to lie entirely suspended.
The factor determining the amount of air circulated
was the number of occupants. This being fixed, the heat
los.-o were computed, and the required temperature of
air from the reheater for extreme conditions was found
to be 120 deg. P., which temperature is given by the
arrangement outlined above.
On the first floor, which has an extended wing, and on
the top floor, Fig. I, steam coils are installed to offset
the heat losses through the roof. This is necessary to pre-
T O W E E
Vol. ±1, No. 14
vent an excess of air i>n these floors, which would occur if
these losses were taken care of by the hot-blast system.
Th ' arrangement of the air duets and outlets on the other
floors is shown in Kg. 5.
The entire heating apparatus is governed by an auto-
matic temperature-controlling system. One thermostat
is located between the primary heater and the air washer.
controlling supply valves on both sections. The valves arc
fitted with differential springs, the outer section being
the last to close, so as to maintain temperatures from 45
ttttflHI
' '* ,
» .
-* ■
->
Fig. 5.
ARRANGEMENT ol All; DUCTS \XD OUTLETS OX
the Center Fioobs
to 55 deg. 1'.. as desired. One thermostat is located in
the air washer, as previously described. One thermostat
of the two-relay pattern, adjustable from 65 to 125 deg.,
is located in The duct beyond the reheater and controls
the four valves on the steam supply to the reheater. Two
thermostats on the first floor, and three on the top floor
control the ceiling coils.
A vacuum system is used in connection with all coils,
radiators and stacks. The condensation is carried to a
6x7xS-in. vacuum pump with suction strainer and vacuum
governor. The discharge on the pump is carried to a
standpipe with a vent to the atmosphere, instead of the
i astomary air-separating tank. From there it flows to
the feed-water heater. With a heating system of this
character it is possible to carry a vacuum of 1 to '! in.
of mercury on the steam side of the system and 7 to 8 in.
on the return side.
The covering i- 85 per cent, magnesia for all -tram
pipes in the basement, being '3 in. thick on the high-
pressure and 1 in. on the low-pressure. The exhaust pipe.
which is in a chase, is covered to the fourth floor, where
the hist connection is taken off. No vacuum return pipes
are covered.
As this is one of the first buildings m this country used
exclusively for the manufacture of cigars to install an air
washer and is in the nature of an experiment, the compari-
son of the results obtained at this factory with similar
factories owned by the same company, but heated by
steam with no ventilation and humidity control, will be
wa tilled with interest.
Siimgp©°Acttiiiag| M^dlipatfiaMc F'assmip
This pump lills the requirements where a uniform flow
of a small quantity of water under high pressure is re-
quired. When motor-driven it may be mounted on a truck
and used as a portable outfit. Jt is provided with a
knockout attachment that automatically cuts olf the deliv-
m m *
~,
V* Mil
t
^3 r^
Single-Acting Triplex Hydrauuc Pump
erv of water, but holds the pressure when the predeter-
mined maximum is reached. A slight drop in the pressure
automatically starts the flow, which continues until the
maximum is again reached. The base of the pump forms
a reservoir for the liquid used in the operation.
PRINCIPAL EQUIPMENT OF THE AMERICAN CIGAR CO 'S NEW PLANT, GARFIELD, N. J.
No. Equipment
2 Boilers.
1 Engine.
2 Pumps
1 Generator
1 Heater
1 Fan. . .
1 Engine .
1 Air washer
I Pump . .
1 Motor
2 Heater groups
•ijHeater groups. .
1 Control system.
! \ i ■ in im system
1 Pump
Kind
Return-tubula
-!i[>
Steam generators
Ide 10x12-111
Duplex... 6x4x6-in
Operating Conditions
Hand-fired. 125 lb. steam,
natural draft
125 lb. steam-saturate I
Main units
Roiler feed and makeup
water Automatic and hand regulated
Ilireet-current . 50-kw Main unit 1 10-220-volt, 3-wire system. .
Combination. 150-hp Heating feed water. Using exhaust steam
Siro 54-in., 25,000 cu.ft. per min Hot-blast system 230 r.p.m.
Vertical, high-speed 10-hp., 6x6-in. cyl Driving fan. 230 r.p.m., 125 lb. steam
W 70-nozzle Washing ventilating air
Centrifugal 2-in... Water for spray nozzles 12(H) r.p.m. capacity, 120 gal
per lir
Direct-current 5-hp Driving cen. pump 1200 r.p.m . 220-volt
Vento, 60-ir. 20 sections each, total 640x sq.ft. Tempering air 0 to 50 deg
Vento, 60-in. . . ... 20 sections each, total 1408 sq.ft. Heating air 50 to 120 deg ...
Thermostat . . Heating system Automatic
Donnelly Heating system Automatic.
Simplex Gx"xS-in Handles condensate 10-in. vacuum
Henry R. Worthington
Westinghouse Elec. & Mfg
Linton Machine Co.
Vmerican Blower Co.
American Blower Co.
Blower Co.
American Well Works
WVstitiL'hnus.- Eire. iY Mfg, Co.
American Radiator Co.
American Radiator Co.
Power Regulator Co.
Jenkins Brothers
International Steam Pump Co.
Anvil 6, L915
row e 8
t63
The pump is built for either gear, chain or belt drive.
The design is Buch that any one of twelve different-sized
plungers may be furnished, ranging from l(i- to 1-in. di-
ameter, advancing by increments of ,V, in. They are ca-
pable of exerting a maximum pressure ranging from 750
to 8000 lb. per sq.in. The three plungers are of the
same diameter and work to the same maximum pressure.
The stroke is 2% in. Each lias a speed of 35 ft.
per miii. at 150 strokes, which is the rated speed, and
gives the pump a total capacity of 0.41 to l.-.'o gal. per
miii.. depending u) the diameter of the plungers.
The suction and discharge valves are located in the pump
cylinder.
_ The plungers are bronze, except on the ■;,- and %-in.
sizes, where steel is used to withstand the high pressure.
The cylinders are cast en bloc. With the fr-in. and the
%-in. plungers cylinders of forged steel are used, and for
the pumps having larger plunger diameters a special
bronze is used. The height over all is 35 in. and the floor
space required is 16x18 in. The weighl is 500 lb.
This pump is manufactured by the Eydraulic Press
Manufacturing Co., .Mount Gilead, Ohio.
Pipiimg' amid Svippart^ irni M^imicSpal
I'.l A. I I. WlLLIAJ
81 N0P8IS — Some unusual features found in tin
steam piping at the East Fifty-third St. Station,
Cleveland Municipal Electric-Light Plant.
The East Fifty-third St Station at Cleveland is de-
signed to operate at 825 to 250 lb. steam pressure with a
superheat of 125 to 150 deg. P., steam temperature of
525 to 600 deg. F. being obtained when the plant was
tested. The boilers are of the Stirling "Delray" type with
two superheaters each, from which the steam is taken
oil' through nonreturn valves ami 8-in. steam lines to a
main header divided m three sections, from each of which
one of the main units is supplied.
One of the features of the steam piping is the use of
flanges welded to the pipes and welded steel nozzles on
the header and manifold, pipe bends being used for all
changes of direction; the only castings used in con-
nection with the live -team piping are the valves. Like
most modern plants, this station is designed upon the
unit system and may be operated a- though it consisted
of three separate plants. In one way, however, it de-
parts from the unit design, namely, in the use of a large
mam steam header instead <>( cross-connection loops be-
tween units. This header is placed in the basement, near
the wall between the boiler and turbine rooms, and is the
lowest point in the steam line. \t is divided in two sec-
tions by an expansion loop ( Pigs. I and I i. eai h section
ending with a manifold tee having four side outlets from
which 6-in. inverted -I""' pipe bends are taken off and
connect with the other section. The combined area of
the bends is slightlj less than the area of the header. The
two manifold tee.- are dead-ended next to the wall by
forged-steel bumped heads welded ,„,, the opposite end
being closed by a blind flange. Each section of the header
is anchored midway between its ends and is supported else-
where by roller-, as shown in Pigs. •-' and 5. At each
anchor point the pipe rests in a heavy cast saddle, to
which it is secured by clamping rings, and band.- welded
to the pipe at these points assist in preventing anj slip-
ping "I' the rinus. Each section of the header contains
one Venturi IIopkinson-Ferranti stop valve by mean- of
which the plant can be separated into three operating
units.
This header, being the lowest point of the steam piping,
is provided with drain outlets piped to a trap set in a pit
below the floor; this provision is necessary, e\en with
superheated steam. A stop valve is placed in each of the
turbine steam leads next to the header, with the ralvi
-tem set at a 30-cleg. angle (Fig. 2). Each boiler lead
Pig. i. Expansion Bend in Main Steam Headek
I- also provided with a stop valve just beyond the ben, I to
the header, and the lead- to the far side of the boiler room
are supported at the boiler-floor level by floor-plates
ami supporting ri i d to permit tree expansion in
the Ion- lead below the floor. These sliding floor-plates
a iv -how i, ii, Pig, (i.
Pig- i shows the construction of two supports for tin
feed-water p i steel bracket an, hor built up ol
angles and plate-, the other a , ast-iron -addle an, hor with
464
P 0 \Y E E
Vol. 41. No. 14
Fig. 2.
South End of Header, Showing Supports
and Axe hoi:
Fig.
Piping at Boiler-Feed Pumps. Looking
North, and Xortii End of Header
■?,6 Extra Strong
Pipe Sends
/ To Exciter
Turbines
-TTr
dosemenf-Hoor A A Ancho
Fig. I.
I4"0.D Header ^ For Drain — ' "Rollers.-
Elevation of Steam Header. Looking West
Holler Support fbrDrain
a steel clamping plate to hold the pipe. Both of these
supports are secured to the masonry by expansion bolts.
Figs. 3 and 8 show the arrangement of the boiler-
feed pumps and the piping at this point. Three five-
centrifugal pumps are installed, all being designed
to operate at 1750 r.p.m. against a pressure head o
ft. One pump, tor emergency service, is driven by a 125-
hp. steam turbine and has a capacity of 350 gal. per
min. The center pump has a ea parity of 750 gal. per min.
and is driven by a 250-hp., 440-volt. three-phase induction
motor. The third pump is driven by a 125-hp. induction
motor and has a capacity of 350 gal. per min. The feed-
water supply is drawn from the hotwell into which the
condensate from the surface condensers is discharged,
a sufficient head being maintained to cause the water to
flow to the V-notch meter through a 12-in. supply line.
All of the pumps draw on a suction header to which the
water from the meter flows through an 8-in. line, and an
S-in. bypass is provided around the meter. From the
pumps the water enters a pressure header from which
lines run to both economizers. Two bypass risers are pro-
vided which connect to the boiler-feed loop. The pressure
end of the boiler-feed system is arranged so that there are
two possible routes for either hot or cold feed water be-
tween the pumps and the boil
The use of electrically driven auxiliaries for the con-
densers, induced draft and forced draft, and for the stoker
drive and boiler feed, eliminate- ;i large amount of small
steam piping and exhaust lines. All of the piping under
high pressure is extra strong lap-welded medium-steel
with east-steel fittings. The low-pressure piping is of
standard-weight wrought iron, cast iron or, as in the
ease of the free exhaust line, spiral riveted pipe. Each
turbine is connected to the free exhaust line by a 24-in.
!{*2 Steel band %"x4*r/J.
Welded fo Header j5traps
A
s
Cast-Skel
Saddle
_ _____ _. j. .
66 >&> 6b
Rolleb SurroRT and Anchob Blocks for
Main Steam Header
April 6, 101.-.
P 0 W B T5
465
free exhaust mite on the condenser. A 21-in. header is
located in the turbine-room basement, just below the
floor, and a riser at. the center of this header passes up
through the floor, then diagonally through the wall into
the boiler room and ends just above the roof. This riser.
CcDsfts Sim Smaall Hmidl'aasthriigifl
%"sieelY/asher
Plate
?f<-a!i
^r-^TfPl tefesfo3 Wood
' k"Steel band
I'.-i ('. \Y. Tiiayki;
When an isolated power plant can be operated at a profit
in ;i district \\ Ihtc the hydro-electric interests are well
developed, the figures should prove important.
In the present instance, the plant consists of two hori-
zontal return-tubiilar boilers, with an aggregate rating oi
226 boiler horsepower, two steam pumps, one power pump,
an open feed-water heater, a draft regulator and the usual
small accessories. The total value of this equipment is
$4100. The building is valued at $3000, the 1 LO-ft. ohim-
ney at $1200, the boiler ami accessories foundations at
$150, and the laud at $1000.
The fixed charges on the boiler plant a re us follows :
Sliding Flooi
oe Bends Le ld-
to Boilers Nbs. i,
:i and 5
;. Cast-Ikon and
Steel Anchors fob
6-In. Pipes
Interest at 5 per cent, on total investment of $9450..
Taxes at 1 per cent, on total investment of $9450. .
Insurance on building and equipment
Special boiler insurance
Depreciation on building and chimney (1.5 per cent.
on $42(111)
Depreciation on equipment (6 i^er cent, on $4250)....
Iti'pairs on building and chimney (1.5 per cent, on
• 1200)
Repairs on equipment (6 per cent, on $4250)
$4 72.50
94.50
15.00
36.00
The operating char:
follows :
which may be called upon to carry the exhaust from three
5000-kw. turbines, is the same size as the header and
i hi' five exhaust valves.
The nominal overload steam requirements of the tur-
bines is about ;0.()00 lb. per hour. This is brought to the
turbine through an 8-in. pipe, the velocity of flow brine
about IK ft. per second. In the exhaust line this amount
Engineer. 70 per cent, of time in boiler plant (70 per
cent, of 52 w.-eks). at $22 per week $800.80
Night fireman, 30 per cent, of time (30 per cent, of
52 weeks), at $1S per week 280.80
Sunday man, 52 days at $2.50 130.00
Supplie
Fig.
Plan oi
it Boiler-Feed Pumps
of steam could be carried with a velocity of about 1 10 It.
per second, at 17 Lb. absolute pressure. The reduction
in cost of the pipe and covering for small sizes is consid-
erable, so that for economic reason- the pipe should be
the smallest size that will pass tin' steam with the maxi-
mum permissible friction anil radiation looses.
TYPICAL CONDENSER DATA AND PERFORMANCE
Coal (1100 urns at $4.21), delivered short tons) 4G20.00
$4790.00
The total yearly charge for the boiler plant i- $7255.60.
With steam at 140 lb. gage, i'w<] water at 200 deg. F., coal
containing 1 t,000 B.t.u. per lb., and a boiler and furnace
operating (lb per cent, efficiency, the evaporation is
0.66X14,000 .
( , or approximately 9.04 lb. water per pound
of coal. The figure, 1022, is the B.t.u.
added to the \'vri\ Mater to produce a
pound of steam. The cos! of evaporat-
ing 1000 lb. of water is 36.5c. which
is found as follow-:
7255.60 ,, ...
x KM"' = 36.5
1100 X 2000 X '-M'4
As the demand for steam increases.
the e\ aporal i :os1 will decrease.
The power plant consists of the 101-
items with their corresponding valuations.
lowing
Land * a lued at
Building valued at
Engine foundations
she, i .■ i ■• npound engini LSO hp., direct -connect-
ed to a 125-kw. direct-current generator
Generator (125 volts i
Engine piping and separator
Switchboard
Apparatus and tools
Automate- lubricator and filter
Total
450
2MI i
1501
700
1000
250
210
,V"ll',o
Condensa-
Actual
Circu-
Hot-
Steam,
i looling
tion Itaie
\ acuum
lating
well
Horse-
Lb.
Surface,
in Lb.
30-in.
i a tei
Temp..
power
per Hi'.
Sq.Ft.
per Sq.Ft.
Bar
Deg. F.
1 1 :■
5,800
S7.000
3,282
26.5
26.8
44
110
12.000
1MI.
8,000
2.5
27. i
72
104
12,000
180,000
8,636
20.8
28.95
49
69
12,000
174,000
8,440
20 6
27.2
53
98
22,000
340,000
16.820
20.25
28.8
54
78
27,000
418,500
21,600
19.375
28.85
57
76
17,000
240,000
9,000
26.7
28.55
45
78
2000 ku
. 2S.S00
3,000
9.6
28.1
75
95
5,300
SO, 000
4,400
IS
1 27.3
1 26.75
44
84
111
106
2,500
46,000
1,300
35.4
27.3
54
101
15,000
300
50
23%
60
120
The engine-plan! fixed and operating charges are
.,n total of $9060 $453.00
90.60
15 ii"
Interest at 5 per
Taxes at 1 per cent on total oi >:<or,n
Insurance on buildings and equipment...
By wheel insurance
Depreciation on building, etc. (1.5 per cent, on $1600)
Depreciation on equpiment i4 per cent, on $7460)..
Repairs on building, etc. (1.5 per cent, on $1600)....
Repairs on equipment, etc. (4 per cent, on $7460)....
Labor (30 per
Supplies (oil, '
■
2 1. in
2 1 mi
298 )n
24.00
29S.40
$1227.80
343.20
200. lie
466
r 0 ^ E R
Vol. n. No. l-i
The engine is operated 300 days for 9 hr. a day, and
switchboard records show the average load to be 140 b.hp.
A recording flow meter shows an average of 32 lb. of steam
perb.hp.-hr. The steam cost is then
300 X 9 X 140 x 3-2 X 10.365
I
= $4415.04
This charge for steam of $4415.04, phis the $1771 for
fixed charges, labor and supp -. a total char.:'' of
$6186.04 for 378, hp.-hr., or a cost of 1.63c. per hp.-hr.
In the three winter months all the exhaust steam [nun
the engine is used for heating the plant. As this exhaust
will have at least 85 per cent, of the heat units available
that are contained in the equivalent weight of saturated
high-pressure steam, it is fair to credit this amount to
the power plant ; hence
•**£« X 0.85 = $938.30
This reduces the annual cost from $6186.04 to $5247.84
Using this basis, the cost per horsepower-hour is 1.
Bcl&el H^cdlip©@&aj.ft F©©d° Wade?
The Eckel hydrostat for regulating boiler-feed water
is illustrated herewith. Fig. 1 shows the device attached
to a boiler and piped to a feed pump. The details of
construction are shown in Fig. 2. The only moving parts
Fig. 1. Pipe Connections of Hydbostat and Pump
in the boiler are the float, tested to 300-lb. pressure,
and the rod connection, which is actuated by the float
lever as the water level in the boiler ri<e< or falls.
The vertical rod is incased in the upright supporting
stand, and it> movement is transmitted to a lever in
the i asing at the tup and on the outside of the boiler shell.
This lever is attached to a rod which pas.-es through a stuf-
fs box and by a series of levers operates a control valve
in the feed pipe.
The feed pump is fitted with a governor, controlled
by the pressure from the water end of the pump. When
the valve in the feed line is partly closed, owing to the
Fig. 2. Htdeostai with Series oe Boilers
height of water in the boiler, the pressure in the discharge
pipe is increased and this pressure is transmitted to the
regulator, partly closing it, and slowing down the pump.
Fig. 2 illustrates the type of hydrostat used on boilers
series, where more than one boiler is fed by the same
pump.
The hydrostat used with a single boiler controls the
Fig. 3. Htdkostat Used with Single Boiler
pump speed and no pump governor is used in connection
with it. as it is a governor as well as a hydrostat.
The control valve is so designed that dirt cannot
-toj i it from closing, and it works like a shear and is sup-
posed to cut off any matter that might lodge between the
ports. The valve does not wire-cut by the passage of
the water; the valve is sectional and may be easily taken
apart.
This regulator, which is made by the Eckel Hydrostat
Co., 158 Mt. Elliott Ave., Detroit, Mich., can be used on
any steam boiler.
It Is ( '(intended that fuel can be saved by using: hisher
steam velocities in pipes; the limit for safety with recip-
rocating engines is S2 to 9S ft. per sec. The Berlin Electricity
Works Co. carried out experiments and obtained consider-
able saving in fuel by eliminating pipes which had been put
in to reduce tin- fall of pressure. — Exchange.
April G, 1915
P 0 W E 11
\t\]
3R
Tm
ijps
.Mrai
By K. M. Gilbert
SYNOPSIS — Advantages and strain consumption
of traps. Explanation of the principle of opera-
tion.
Steam traps have been known for many years as a
moans of feeding boilers, but it seems that they have not
been used in small power plants as widely for this purpose
as their merits would warrant. For small boiler plants
up to 300 hp. a steam trap is an economical and satisfac-
5&. Automatic ^-Automatic Vent Valve
Outlet Check
'Valve
■ Trap Body
^-Inlet Check Valve
Fm. 1. Diagram of Elementary Tkap
tory means of feeding hot water into a boiler. A good
trap requires little attention and no lubrication; it has
no piston or piston rods to pack, and but few wearing-
parts.
For these reasons the repair charges are low — much
lower than for a feed pump. For a 100-hp. boiler at lull
load, a steam trap for boiler feeding would require about
twenty pounds of steam per
hour; a small duplex steam
pump for the same purpose,
about one hundred twenty-five
pounds. The use of a trap in-
stead of a feed pump would
at this rate save 100 lb. per
hour, which at an evaporation
nf 1 tn 1 means 1 1 lb. of coal
per hour, or 110 lb. per day
for each Kill hp.
There are two general classes
of traps, the return ami the
nonreturn. The return trap is
used when it is desired to ele-
vate or discharge the water
against a head or pressure equal to or greater than that of
the water entering the trap, as for feeding boilers or
draining a vacuum system. A return trap lias an auto-
matically operated live-steam valve and usually a vent
valve, both of which are operated by the action of the
trap when sufficient water has entered.
A nonreturn trap has no Live-steam connection, and for
this reason it cannot discharge its contents against a head
any greater than that of the water entering it.
There are several types of traps which, if named accord-
ing to the method of operating, the valves may be called
tilting, bucket, float, expansion, and differential. These
various types have their advocates, but from the writer's
experience of several years he has found that the tilting
trap has given the best service. All of its working parts
are accessible and within the sight of the engineer, who
can tell at a glance how the trap is working.
While the methods of operating the valves of the several
traps vary, the principle of operation is the same for all
types and, for the benefit of the young engineer, can be
explained by aid of Fig. 1. The drip or feed water for
the boiler enters the body of the trap through the inlet
check valve. When sufficient water has entered, the oper-
ating mechanism of the trap is so arranged that either
the weight of the water, a float valve, or a bucket, etc.,
automatically closes the vent valve and at the same time
opens the live-steam valve. The steam pressure then acts
on the surface of the water in the trap, the inlet check
valve closes and the outlet check valve opens, enabling the
steam to force the water out of the trap. When the trap
is nearly emptied the steam valve is closed and the vent
valve automatically opened. The pressure in the trap
body is reduced to atmospheric so that the drip water can
enter and again fill the trap. From this explanation it
should be readily seen that the steam consumption for
each discharge of the trap is about equal in volume to that
of the trap reservoir.
Fig. 2 shows the arrangement of piping, traps and feed-
pump connections to two return-tubular boilers. The
feed pump is for use while examining or repairing the
traps. The trap discharging into the boiler must be
placed about four feet above the water line in the boiler,
then when the steam is admitted to the trap this head is
sufficient to overcome the friction of the piping and check
feed Trap
Traps to be vented to ash pit
or to other convenient points
low Pressure Drip Trap Discharge to
Boiler Feed Trap
Fig.
Piping fob Tilting-Tb w
date Valve Check Valve
Boiler-Feed Installation
valves so that the trap is quickly discharged. In all cases
the water must flow into the I' 1 trap for, unlike a pump,
it has no power to raise water by suction. When by the
pressure in the system the water cannot he raised to the
feed trap, another trap must he employed to do this work.
The Low-pressure trap ( Fig. 2) is connected to discharge
the low-pressure drips into the feed trap. Its action is
the same as the feed trap, ami the use of the live-steam
connection makes it possible to raise the water.
The pipe connections to and from all traps should be
sufficiently Large and free from numerous turns. The pipe
connections to nearly all traps are too small, and the inlet
and discharge pipes should be one or two sizes larger than
the trap connections. The inlet pipe line should slope
468
V 0 W E E
Vol. 41, No. 14
toward the trap, and the outlet should slope downward in
the direction of the flow of water to the boiler. An air
chamber on the discharge line will prevent the noise and
shock which sometimes occurs from water-hammer.
The check valves should be of the swing type and the
others of the gate type. The live-steam connection must
be made diiect to the boiler shell or as close as possible, so
as to have the full steam pressure available for operat-
ing the trap, as a pound difference in pressure between
the trap and the boiler may prevent satisfactory operation
and reduce the capacity of the trap. The packing used
around the valve stems should be of soft material and well
lubricated. Most of the tilting-trap troubles come from
using a hard asbestos packing which in a short time be-
comes hard and binds the stems. The packing should be
braided and well lubricated with graphite.
wwmm
By T. B. Hyde
Nunnmps
SYNOPSIS — In view of the many different ex-
pressions relative to pump slippage which have
lately appeared in Power, the following article
will be of much interest fo tin' many concerned
with the subject. The volume of slippage depends
upon tlie discharge and suction pressures, condi-
tion and tightness of valves and plungers or pis-
tons.
Slip is a "dead"' loss of power. The useful work done
by a reciprocating pump is measured by the amount of
liquid pumped, multiplied by the head pumped against.
This is less than the indicated work of the pump cylinder
by an amount equal to the slip. Slip is therefore defined
as the difference between piston or plunger displacement
and the actual volume of pumpage expressed as a per-
centage of the former.
Where the pumping unit is large slip is usually
closely watched and kept at a minimum, but the same
cannot be said of many smaller pumps, particularly
those used for boiler-feeding purposes. As an ex-
ample the writer recently noted a feed pump run-
ning with 80 per cent, slip : in other words, its dis-
placement was five times its pumpage; its useful c
horsepower, represented by water delivered to the "
boilers. 4.20; its actual water horsepower, four times ;
that, say, IT. The steam consumption, or water rate, *;
of these small duplex pumps is seldom less than 120 &
lb. per water horsepower-hour, and usually higher.
Using this conservative figure for an assumption,
this pump was using 17 X 120 = 2040 lb. steam per
hour, of which so per cent., or 1632 lb. (47 boiler
hp.), was spent for slip. A feed pump can be han-
dled nicely on 15 per cent, slip, so that there was a
clear waste of 38 boiler hp., or in money, roughly,
thirty cents per hour. The main units were noncon-
densing ; it was summer and there was an excess of ex-
haust steam, so there was no justification of this waste.
Slip is greater at low pump speeds than at high. In
order to understand this clearly we must differentiate be-
tween per cent, slip, or "slip"' as it is called, and actual
volume of slip. The latter is the difference between dis-
placement ami pumpage and is reduced to per cent, slip
by dividing by displacement. The volume of slippage
depends upon discharge and suction pressures, condition
and tightness of valves and plungers or pistons, as the case
may be. It may be likened to a leaky globe or throttle
valve ; the greater the pressure, the greater the amount
of leakage ; the greater the amount of opening, the greater
the amount of leakage. Wherefore, with a given pump.
with valves and pistons in a given condition, the actual
volume of slip may generally be said to be independent
of speed ; a function of discharge pressure and time only.
But in reducing to per cent, slip, we divide this constant
amount by the displacement, which varies directly with
speed. Hence, with high pump speed (large displace-
ment) per cent, slip will be low, and vice versa.
Slip may be as high as 100 per cent., as is the case of
a pump working against a closed discharge valve or a fire
pump drifting along at two or three revolutions per min-
ute, maintaining a constant pressure on a sprinkler sys-
tem. Slip may be as low as zero or even be a negative
quantity. In the latter case the pump is actually deliver-
ing an amount of water greater in volume than the dis-
placement of the pump itself. When this occurs it is due
to the rise in pressure in the suction line when the flow
is suddenly checked, forcing water through both suction
and discharge valves and into the discharge line. This
action is similar to the hydraulic ram, where the velocity
__i2
£_^/
K,p
r-42
r^S
'/ip
It 24 26 28 30 32 34 36 38 40 42 44 46 48 50
Revolutions per Minute
Fig. 1. Slippage-Test Results of Laege Pumping
Engines
of the water being suddenly checked, it is changed into
pressure sufficient, to force a small quantity of water into
the discharge line against a pressure considerably greater
than the supply head. This negative slip occurs only un-
der a combination of favorable conditions, among which
are high velocity of water in suction pipe with slight suc-
tion head, low discharge pressure and tight valves. To
produce negative slip the amount of water passed through
by this "hydraulic-ram" action must be sufficient to more
than balance the normal slippage through the valves.
Fig. 1 shows the result of slip tests on two large cross-
compound steam-driven flywheel pumping engines. The
pump plungers of each unit have a displacement of 306
April 6, 1915
POWK B
469
gal. per revolution. These tests were conducted with
considerable accuracy, the water being measured by a
venturi meter in the pump discharge line. The discharge
pressure was 10 lb. per square inch gage; suction head
practically zero. In these pumps, when valves are in good
condition negative slip is frequently found at the higher
speeds.
Kg. 2 shows a slip test on a 12x7xl2-in. steam duplex
feed pump. Incidentally, this test was made to calibrate
Jsiasft IPOS' Fuasa
[More stories of stupidity and ignorance competing
with "So in e Original Ideas," as printed Jan. 19, 1915.']
35
30
2S
20
15
10
6
"0 2 4 <6 8 10 12 14 16 18 20 22 24
Revolu+ions per Minute
Fig. 2. Slippage Test on 12x7x12-In. Duplex Pump
the pumpj so that a revolution counter could be attached
and the pump used as a boiler feed-water meter to measure
the station boiler load. Such a slip test is simple and can
be made by any engineer in the following manner, without
any extraordinary apparatus: Blank off the regular dis-
charge line and pipe the discharge to weighing barrels or,
as was done in this case, to a larg i tank that had been
previously measured. Old fire hose was used for piping.
Put a throttle valve in the discharge line near the pump
and place a pressure gage between the pump and this
valve. At whatever speed it is desired to run the pump,
maintain the discharge pressure, by means of this valve,
the same as that against which the pump normally works.
Two other conditions — suction head and water tempera-
ture— should be maintained the same, although they are
of lesser importance than pressure and speed. In the
test referred to, these were taken care of by pumping from
the regular feed-water heater through the regular suc-
tion line. Live steam should be admitted if necessary, to
maintain the normal feed-water temperature. The pump
may be calibrated at a single speed, which should be that
at which it normally runs, or if desired, the calibration
may be extended over a range of speeds, but no compari-
son can be made between test and running conditions un-
less both pressure and speed are the same. For accuracy
suction head and temperature should be the same, al-
though any change in cither, sufficient to introduce any
serious error in results, would usually make itself no-
ticeable by hammering of the pump, indicating that the
pump was getting either vapor or air.
Duplex steam pumps tend to '"short-stroke"' at low
speeds. Strictly, this should not be charged to slip, for it
is neither a waste of power nor of steam. In the above
test, however, is was charged to slip, in order that the re-
sults of the slip test might be applied to the readings of
the counter to obtain the amount of boiler feed. This
method of measuring boiler feed can be recommended only
for places where suitable meters are not available.
We are pleased to give you the following, which we
believe is good enough to publish in Poweb
A new salesman was sent out to sell a steam engine.
The customer advised him that he would like an engine
that would run both over and under. The new salesman
explained to him that all he would have to do would be
to turn the throttle to the right to make it run over and
to the left to make it run under. — I. N. Beeler, Syracuse.
N. Y.
In a certain felt factory static electricity caused trouble
at the cards. I sent an electrician to the plant, instruct-
ing him to arrange a "comb" close to the drive belt and
connect it by wire to a gas pipe, water pipe, or any con-
ductor that ran to ground. Going to the plant afterward
to see if the trouble had been completely removed, I found
that instead of being connected to a pipe the wire was
run to a pail on the floor, which was partly filled with
water. The intention, I was told, was to empty the pail
when it became filled with electricity.
In another plant I noticed a pipe with a valve connei ted
to the steam space and running down beside the boiler
and through the setting. The engineer opened the valve
occasionally. Thinking it might be some new smoke-con-
suming device, I opened the furnace door to see how it
operated and discovered that the pipe was connected to a
small bag on the bottom of the boiler. I asked the pur-
pose of the pipe and was told that the mud and scale had
a tendency to settle in a bag on the bottom of the boiler
and that by means of the pipe he could blow steam into
the bag and displace the scale.—./?. McLaren, Medicine
Hat, Alta.
At one time along my trail of bygone experience, I hired
out as engineer of a grist mill that was located in a region
wherein capable engineers were by no means abundant.
I arrived in the village at supper time on the day
before I went to work, and didn't have much of a chance
for a preliminary look around. In the morning, when I
had everything in readiness, as I thought, for starting the
engine and was about to turn on the steam, the colored
man who looked after the place at night handed me a
stout bludgeon, with the remark: "Heah am yo' stahtah,
Boss. Yo' kaint staht dis heah injine 'thoutyo' stahtah."
"Starter for what?" I inquired.
"Why, fo' ill- heah twadlash," be explained, as he indi-
cated the head-end valve arm.
Sure enough! It wouldn't stay hooked up on the head
end at starting, and my predecessor had apparently ac-
cepted it as a matter of course that the only thing to do
was to keep prying the valve open until the governor
rose to a running position. Of course, it was simply a
matter of adjusting the safety cam on that end. This I
quickly attended to.
At sight of the engine starting off unaided by the
hickory stand-by he had offered me, my Senegambian
mentor seemi d transfixed with the wonder of it, while his
visage took on an expression of dumb amazement.
"Laws sakes, Boss!" he exclaimed when he recovered
his breath, "yo' sho done chahmed away dat hoodoo, what-
cvali yoJ done!" — M. ]>. Conroy, St. Louis, Mo.
4T0
POWER
Vol. 41, No. 14
By Everard Brown
SYNOPSIS — Improvement of load factor and
plant economy us well as regulation, particu-
larly in fin1 case of hydro-electric generation.
where storage batteries are employed to assist on
the peaks of the total. Typical load curves show
this for different flosses of service.
In large central stations for electric power and railway
service the use of storage batteries is common. Because
of their rather high initial cost, however, this use is
somewhat restricted to the larger power plants, although
there are some installations among the smaller stations
also.
The primary object of a storage battery in electrical-
railway service is to relieve the generating apparatus of
the larger fluctuations in load by taking care of the peaks
that occur at certain periods of the day, and also to act as
a reserve in case of a breakdown. By relieving the station
of such fluctuations the generating units are free to oper-
ate at a steady and, consequently, an economical load.
Moreover, storage batteries discharging on the peak loads
Fig. 1. Battery ix Power House — Railway Service
and taking a compensating charge during the period of
light load will raise the load factor, thereby improving
the economy of the plant; and, by taking slight peaks
mi an increasing station load, they retard the time of
starting additional engines. Pigs. 1 and 2 show the
fluctuations and peak loads over short periods in railway
service as taken care of by a storage battery. In both it
will be noticed that the battery is discharging much more
than it is being charged. Such a condition occurs, natu-
rally, at times when the traffic begins to increase or lights
are put on, but not to such an extent as to warrant the
starting up of another generating unit.
Heavy line batteries or battery substations are fre-
quently used on railway and district lighting systems to
relieve both the power station and the feeder system, but
principally the latter, at times of high peaks. At other
times they are used to regulate the voltage and care for
the variations in the current. Without batteries the
peaks can be taken care of only by extra generating ap-
paratus at the main power station and extra feeders to
the center of the load district. The substation battery,
being located at or near the point of heavy load, elimi-
nates these requirements and relieves the system of fluc-
tuations, so that the cars or the lights or both, as the case
may be, can operate at a steady voltage. The operation
of a railway line battery taking fluctuations is indicated
by Pig, ■'!. which shows that current was absorbed and dis-
charged by the battery at very short intervals. In this
Ht±r ~r
jtiu j
H4JI t
■"600 4+4-
<u 4<4-
2L500p±
' A. j* \j£)ISCHAf?6
\ N
<300 Tp
200
7 V: ^1||\#^:^:
1 11 1 1 1-11 1 1 1 1 i i i M i 1 1 1 1 Mi -,
100
Fig.
Battery' in Power House — Railway Service
case, however, the discharge is fairly well compensated by
the charge.
In rotary-converter substations storage batteries may
also be used to advantage. The installation of sufficient
storage capacity in such a substation will relieve the con-
verter of current fluctuations, so that the load on the
transformers, high-tension transmission lines, and the al-
ternators, engines and boilers in the generating station
m p.m p.n. P.M.
Fig. 3. Railway Line Battery Taking Fluctuations
may be maintained practically constant. An illustra-
tion of this may be seen in Fig. 4. The line pressure is
maintained between the limits of 450 and 550 volts and
is indicated by a nearly straight line. In this curve it
will be noticed that the greatest demand upon the sub-
station is between the hours of <> and lo in the morning
and 5 and 9 in the evening. This is typical of street-
railway service. It will be seen that the greatest amount
of charging is done between 9 p.m. and (i a.m.. at which
time the load is the lightest. Some charging is also done
April 6, 1915
pow e i;
1U
from 10 a.m. to 5 p.m., showing that the power-gen-
erating capacity is in excess of the load requirements dur-
ing this period.
In hydro-electric plants good voltage regulation is often
a difficult matter. At full loads a waterwheel usually
Fig. 4. Railway Line or Substation B atteky Taking
Fluctuations and Peak Loads and
Regulating the Voltage
takes all the effective water that can pass through its
opening at a given head, consequently an overload means
a drop in speed. The load variation, moreover, is gen-
erally so rapid that the inertia of the water in the pen-
stock prevents satisfactory speed regulation, regardless of
how sensitive the governor may be or how ample the wheel
capacity. These troubles can be largely overcome by
12000
|
TrtTvi/
1 J A 1
Ml
I
■ t
j
C"
1 'I
9000
'
X
J~
hi
k
s
V*
W\*
^"m
'"
[I
-'■
.
"
g 7000
F\ iM''\ w
r v
\f
AICO
E"6000
\
l
!
5000
y,
\
4000
\
3000
1
\
,
2000
XCHARGE
'
1000
12 I 2 3 4 5 6 1 8 9 10 II 12 I 2 3 4 5 6 7 8 9 10 II 12
Pig. 5. Battery at Railway Power House Taking
Peaks
the use of storage batteries. It might, be said, in fact,
that the introduction of such a battery is really equivalent
to increasing the capacity of the plant in the same ratio
that the peak removed bears to the average load. Re-
sults of such an installation may be seen in Fig. 5. In
this station as much of the power as possible is generated
by water ami a steam plant in connection with a storage
battery helps out on the peak. From midnight till 5 a.m..
it will be noticed, the hydraulic generator had a surplus
of capacity above the load requirements, so that some
charging of the battery takes place. Then from 6 :30 to
8:30 a.m. the battery helps the water power and defers
starting np the steam plant about two hours.
For small light and power plants of limited output.
Figs. f> and 7 show what the storage battery will do. In
such plants the day load is usually light : therefore, a
comparatively small battery will supply current for a
part of the time and the battery can be charged in
the evening or early morning, when the plant is in opera-
tion. In this manner a day service can be maintained at
little expense for labor and with a materially decreased
operating cost per unit of output. In addition to this
there is the advantage, common to all kinds of power sta-
tions, of having an extra source of power ready in casi of
demand, thus insuring good regulation of the voltage.
In considering the installation of storage batteries thi
room should really he in a separate building, if possible,
away from the rest of the equipment, and in order to lie!,
down the temperature and to free the room from acid
spray it should he well ventilated. In some instances il
may even he necessary to resori to artificial ventilation by
means of a fan or blower if the battery does considerable
peak-load work and requires almost continuous charging
at certain hours. As the gases given off during the
charging of a battery form an explosive mixture if con-
fined, this need of proper ventilation is important, as is
also the keeping away of any exposed flame at such a
time. In cold climates it is sometimes necessary to heat
the battery room in order to obtain the maximum capac-
ity-
In charging a battery the rise in voltage is quite grad-
ual except near the beginning and the end of a charge,
when it becomes more rapid. When fully charged the
o400
II M i
X
.
_!'
- ' -.--T--0
r° ioo
P 100
rBh
Ikz
ntk
f~m
fWte^fe
O A.M.
Fio. li.
Batteey Taking Fluctuations of Motor
Load — Small Plant
color of i lie positive plates varies from a reddish brown to
nearly black and the negative from a pale to a darker slate
color. The negative plates, however, are always lighter
in color than the positive. Excessive discharging should
always be prevented if possible, as it has a tendency to
cause excessive heating of the electrolyte and disintegra-
tion of the plates. This disintegrating as well as buckling
of the plates and sulphating are the most serious troubles
incident to the use of a storage battery, hut these can
be avoided to a large extent by proper attention. Man-
II
I
i\
BATTl
Rr
LOAD
1
h
11
, IMI
\1~A
1
\ i v li!
n
'\ j m Y\
1 1'\ 1
LJLvt JIT
111 Ijl'l i \ l\_
tttp.n'
^J TJilV '<
■"nrVftt. i
r
H
: 1 n?HM
A
\y
1 U.UII.V
\
'oENEh
A10R
LOAD
1 1
■
1
1
Fig.
5L0
Battery Taking Fluctuations at Railway
Power Bouse of Limited Output
agement of a battery installation requires more experi-
ence and care, however, than the handling of electric gen-
erators, because of the chemical actions which occur in
the former and which are more difficult to determine and
correct than mechanical or electrical difficulties encount-
ered in the generator. As for depreciation charges, they
are somewhat higher, averaging about 8 to 10 per cent.
4?2
I' ( ) W E R
Vol. 41, No. 14
The high- and low-water alarm column, Fig. 1. has
the outside appearance of an ordinary safety water col-
umn. It differs,
however, in thai
it lias no floats.
Instead, it has
two solid metal
weights hung one
above the other
by bronze rods
( Fig. 2 ) from the
opposite ends of
two bronze levers
which rest on a
bronze knife-edge
fulcrum.
The two weights
are so designed
that the bottom
one is the heavier
when both weights
hang in steam or
w hen both are
submerged, as
would be the case
at extreme low or
high water ; the
Fig. 1.
Safety-First Water
COLl-M x
top one is the heav-
ier when the bottom
one only is sub-
merged, as would be
the case when the
water level is be-
tween the top and
bottom gages.
One of the bronze
levers is connected
to the alarm whistle
valve by a km
bearing. The valve
and seat are made of
monel metal.
Referring to Fig.
2. it is evident that
when the water
stands at any level
between the top and
bottom gages, the
bottom weight will
be submerged and
the top one will
hang in the steam
space. Under these
conditions the upper
weight will weigh
more than the lower
one, and will hold
the whistle valve
closed.
Should the water
fall below the bot-
tom gage, the low-
er weight will weigh more than the upper one. which
will rise and open the whistle valve, thus giving the
low-water alarm.
Should the water rise above the top gage, the upper
weight will weigh less, and the lower one will overbal-
ance it, which causes it to rise and open the whistle
alarm for high water.
This appliance is manufactured by the Engineering
Company of Philadelphia, Harrison Building, Philadel-
phia, Perm.
By F. \V. Salmon
Many steam-driven air compressors have to operate at
speeds differing greatly from hour to hour to suit the
demands for air. This makes it desirable to choose the
cylinder ratios of the two-stage air ends with great care,
so that the machine may operate steadily and smoothly
without danger of stopping on a dead center even at the
lowesl -peed, for naturally, a two-stage compressor will
be chosen in most cases to secure economy in power for
pressures of 80 lb. or higher, and in the ease of large
compressors, often for lower pressures.
§ Z3
|f 2
£* 1
| 1
IJJiwefsp
Jr„10 6o2&l
^==^>
~~mcoo
Fig. 2. Abbangement
of Weights axd
Levees
<S v60 80 100 120 140 160 150 200 220 240
Discharge of High Pressure Cylinder in Pounds perSquare Inch
Ratios with and without Ixtercoolixg
The curves show the volumetric ratios required for a
two-stage air compressor taking dry air at atmospheric
pressure at sea level and delivering it from the high-
pressure air cylinder at pressures of 60 to 250 lb. gage,
both cooled and not cooled between the cylinders. More-
over, they are calculated to give the same power in the
high-pressure cylinder as in the low-pressure.
In various books on compressed air. such as that by
Frank Richards, Kent"- ••Mechanical Engineers' Pocket-
Book." and Suplee's ""Mechanical Engineers' Reference
Book.'" are given tallies showing the horsepower required
(neglecting friction) to compress and deliver one cubic
foot of free dry air per minute at atmospheric pressure,
to given discharge pressures, both isothermally (perfectly
cooled between the cylinders and during the compression )
and adiabatieally (not cooled at all). This given horse-
power has been divided equally between the two cylinders
and the mean effective pressures calculated for each, as
well as the resulting intercooler pressure, which may be
aken as the initial pressure for the high-pressure cylinder.
Hence the volumetric displacement to meet these condi-
tions could lie readily calculated lor several of the pres-
sures given, including the 60-lb. and the 250-lb., and
a smooth curve drawn through the points so obtained on
the chart. This covers the range of pressures needed in
over 95 per cent, of the air compressors sold, and it can
April (j, 1915
P OWEfi
473
be read close enough for all ordinary work, because in
commercial practice air compressors are rarely made to
bores of fractions of an inch.
Practically all air compressors operate between the
limits shown by the two curves. Even in a single-stage
compressor the air is cooled somewhat during compression,
ami yet in the best two-stage machine it is never quite
as perfect as isothermal compression; hence in practice
it is wise to choose the nearest commercial cylinder sizes
that fall between the curves shown in the chart. Of
course, one should consider the actual volume of air dis-
placed from each cylinder rather than the piston displace-
ment, as the cylinder ratio depends upon the volumetric
efficiency of each cylinder, which is rarely the same for
both the high- and the low-pressure .cylinders. This is il-
lustrated in the following example:
Assume, that in order to deliver the air required, a
2 4-in. low-pressure cylinder will be used having a 30-in.
stroke and giving a volumetric efficiency of 0.90 for this
stroke with the type of valves used. The size of the high-
pressure cylinder is desired that will discharge air at 100
lb. gage, with the same stroke, but with a different type
of valve which will probably give a volumetric efficiency
of 0.85.
Running up the 100-lb. line the best cylinder ratios are
found to be 2.11 not cooled or 2.30 cooled. As both cyl-
inders are to have the same stroke, only the areas have
to be considered ; hence, if A represents the area of the
low-pressure piston in square inches and a the area of
the high-pressure piston in square inches, then,
A X 0-90
constant X 0.85
452.4 X 0.90
208 sq.in.;
2.30 X 0.85
say I614 in. diameter (if fully cooled), and
452,4 X 0.90 .
a = 2.11X0-85 -2*"g-"*-J
say 17 in. diameter (if not cooled).
Thus, there is not much difference, and as explained
above, actual practice will lie between these two curves.
Of course, if the cylinders are of different strokes, their
volumes must be considered instead of their piston areas.
valve C fur air control and a mercury gage tapped in
between it and the submerged tube. Air must first be
compressed in the tank (if no service supply is con-
venient) to a considerable pressure in excess of that due
to the submergence of tube .1, which may be determined
in the following manner: Upon opening the valve (' and
upon closing the same after a maximum pressure is in-
dicated, the mercury column should recede an amount
which will represent the friction of the air in the tube at
the rate at which it has been admitted. The static read-
ing is then noted.
Upon starting up the pump or air lift, the operation is
repeated, and the difference in the two static readings
represents the recedence of the well level. These may
be reduced to feet and inches and plotted against "pump
delivery."
A similar device for determining the total head under
which the pump operates is indicated at B, Fig. 1. The
x%2%%Z2Zy,
Level with
Pump in
Operation
Method of Determining Recedence and
Pressure of Deer Wells
ES.<e<e@dl@iae@ Sinai
By G. B. Covi m;th\
The recedence in level of a deep well, due to its being
pumped at various rates, furnishes reliable data as to
its capacity. The method of determining the differences
in level by an apparatus which may be either constructed
as a permanent fixture or made up as a "portable," may
be of interest, as in most cases no space is available in
the well casing in which to lower a float or other device
by which to gage the levels.
For determining the recedence a tube A, shown in the
sketch, is let down the well outside the discharge casing,
so that the submerged end will be several feet below the
natural water level, which, if not known, may be ascer-
tained by experiment.
The tube may be of V^-va. pipe made up as shown, with
same process of operation will give accurate results with
reference to the head under which the pump is working.
The friction head without the use of such a device could
only be guessed at.
Obviously, all readings must be taken immediately after
shutting off the air supply at C or D, otherwise erroneous
readings might result, due to a change in temperature of
the air confined in the tubes, or slight leakage.
According to the "Electrical World," the main prime mover
in the generating station at Independence, Kan., is a double-
acting twin-cylinder Strait gas engine, and at one time when
this machine was needed to help carry the load an ex-
haust valve began to give trouble. Shutting off the gas and
ignition from the cylinder affected, the men on duty opened
the valve chest, took out the defective valve, and replaced it
in less than three hours without stopping the engine. The
greatest difficulty experienced came from exhaust gases that
were discharged up through the manifold from other cyl-
inders. This trouble was overcome by placing a small motor-
driven forge blower in such a position that its blast drove
these foul gases away from the workmen's faces.
i; i
P 0 W E B
Vol. 41, No. U
Surface Comideiniser for C©mm<
inaomiwes\MIhi Edisoim
sun
The accompanying drawings show the largesl Wheeler
surface condenser so far built, which is to be installed
in connection with a 35,000-kw. turbo-generator at the
Northwot Station of the Commonwealth Edison Co., of
Chicago.
Looking- first at the end elevation, the circulating wa-
ter entering the station by the inlet tunnel shown at the
bottom of the drawing is picked up by the 3i/ox4i/o-ft. rec-
tangular suction pipe of the circulating pump. This
The circulating pump is of the tri-rotor high-speed de-
sign for direct-connected drive at 1500 r.p.m. The tur-
bine is a specially designed unit built by the General
Hie. trie Co.. arranged for driving the circulating pump
from one end of the shaft and the air purnp from the
other, as shown in Fig. 4.
The deli wry id' the circulating pump is connected
through an expansion joint with the water intake of the
condenser, and under normal conditions 50,000 gal. of
Fig. 1. End Elevation of Laege Wheeleb Surface Condenses
pipe is in the form of a gooseneck, the top of which is be-
tween 11 and 12 ft. above the pump center. The pump
is below the water level, but is protected from flooding
by this siphon and no valve is needed. A priming pipe
shown connects the pump with the water in the riser of the
siphon when the small valve is opened, and this enables
tin- pump to pick up its suction and draw the main vol-
ume of water over the siphon.
water per minute Bows in two passes through the con-
r, leaving at the upper left-hand segment in the
end elevation, Fig. 1, through a circular discharge main to
the outflow tunnel.
Steam is exhausted from the main turbine through a
passage about 12x14 ft. in area. The contour of this
passage is shown in the plan, Fig. 3.
Upon entering the condenser, the steam first impinges
April 6, 1915
r u w e i;
i;.-
upon feed-heating tubes arranged at the top of the shell as
shown mi .1.1.1 m Pig. 7, through which the condensate is
pumped before going to the boiler plant. After giving up
part of its heal to these tubes, the steam flows into the con-
densing space proper, which is arranged with extra wide
tube spacing and with the tubes disposed in linos parallel
to the flow of the steam. A steam holt extends well below
the center of the shell, thus admitting steam well down
mt" the side, of the condenser, all of these featuree com
bining to give free flow of -tram int,) and anion- the
tubes. The air is drawn oil in the center at the bottom
of the condenser through a lai- tlot pipe, whirl, also
carries off the condensate. Baffles CO at the sides pre-
vent the short-circuiting of the steam to tl„ tlet.
compression channels; and these plugs, by the momentum
' "" « ll'",r bigh velocity, force the entrapped air before
them mio the discharge passage against the pressur the
atmosphere. The hurling water enters at E, Pig 5 and
is discharged with the air at C. In Pig. 2 the combined
air and condensate pump is shown at .1. the hurling
"rater entering at E and discharging at Q, into the wed
below, the air separating off, the water passing through
,l"' cooler alongside, on its way back to the pump The
condensate flows l.\ gravity to the other impeller 0f the
I'1""!' :lt the lei, „, pig. :,, and is discharged through
the pipe F, through the heater tubes at the top of the
condenser and then to the boiler plant.
The combined Wheeler condensate and turbo air pump
>j<- -V- -16-2'
^.ls?._
fl.-S'
Fto. ■>. Longitudinal Elevation of the 50.0<)<)-SQ.Ft. Condenses toe the Commonwealth Edison Co.
This arrangement of a single outlet for the condensed
steam and for the noncondensible vapor, is unusual in
ondensing units, but was possible in this instance
of the design of air pump which was employed. A
soetion of the pump is shown in Pig. 5. The air and water
'-nter the pump by a common pipe, hut are handled sep-
arately within the easing. A- the condensate enters the
chamber A, the air turns off from it to the compartment
B, and is forced out into the chamber C by a turbo-
air pump impeller shown at DD. The action of this
pump is shown in Fig. 6. The impeller diseha
at high velocity streams of water which are cut in-
to plugs by the sharp edges of the separations of the
is driven by the same auxiliary turbine which drives the
tri-rotor cir< dating pump. Thus the condenser auxiliaries
are ?erj much simplified, require less floor space and pip-
ing, and less attendance.
In order to allow the condenser free play under varying
conditions of vacuum, temperature, etc., its weight is car-
ried upon 18 I, caw railroad-type springs, as indicated in
Figs, i and ■.'. at 888, the springs resting upon heavy
concrete pillar-. The shell of the condenser is mad,
of heavily ribbed cast-iron sections, division being hori-
zontally at the center and vertically at the center, making
eight sections in all. The weight of shell, tubes, water
boxes, piping and contained water will he approximately
476
POWER
Vol. 41, No. 14
200 tons, but this downward force is counterbalanced by
an upward force when the vacuum is 29 m., of nearly L70
tons — the upward pressure of the atmosphere on the pro-
jected area of the 12xl4-ft. opening.
At its maximum capacity this condenser takes care
of 400.000 -+■ 50,000 = 8 lb. of steam per sq.ft. of heat-
ing surface per hour, which is •■some steam" even if
it be allowed that 15 or 20 per cent, of it has been
Fig. 3. Plan of Condenser Piping and Auxiliaries
Pig. I. Plan, End and Longitudinal Elevation of Tukbixe-Driven Pumps
There are 50.000 sq.ft. of surface in the condenser,
made up of 18 B.w.g. brass tubes. The rated capacity
of the condenser is 360,000 lb. of steam with a maximum
of 400,000 lb. per hour, and the vacuums to be maintained
throughout the year average about 20 in.
already condensed. Imagine an immense pan, 250 ft.
long and 200 ft. wide, full of water, over a fire burn-
ing with an intensity which would evaporate from every
square foot of the water surface over twice as much water
as a boiler does at its rated capacity, and you have an
April 6, L915
P 0 W E 1!
vn
irk which I his condenser has to
idea of the rate
undo.
At 75 lb. of condensing water per pound of steam the
condenser would require 75 X 400,000 = 30,000,000 lb.
of circulating water per hour or over 130 mi. ft. per sec,
an amount which with a fall of 10 ({. would develop
30,000,000 X 10 X 0.80
33,000 X 60 ''"'' /l/K
and which flowing at the rate of 2 ft. per sec., a rather
high rate for a mill race, would make a stream 10 ft.
wide and 65 ft. deep. At 2!) in. vacuum, or at an av-
erage pressure which would support one inch of mercury,
the volume of a pound of dry-saturated steam is (154 lb.
At its maximum capacity the condenser handles 400,000
lb. per hour or
645 X 400.1 ii id
3600
= 71, fid' cu.ft. prr sec.
which to pass through the I2xl4-ft. passage by which
the condenser is connected to the turbine would have to
have a velocity of 427 ft. per sec. One hundred miles
per hour, which is less than 450 ft. per sec, is charac-
terized in the wind tables as an ••immense hurricane."
It is true that steam initially at 200-lb. gage, and
Pig. 5. Combined Condensate and Tukbo Air Pump
with 400 deg. of superheat would condense between 20
and 25 per cent, of itself by expanding to 29-in. vacuum,
hut this is for the academical case of true adiabatic ex-
pansion and a 400-per cent, turbine. If the steam rate
is 8 lb. per hp.-hr. corresponding to 42 lb. per kw.-hr.
and an over all efficiency of 90 per cent, the turbine
is converting
8546.56 -~ 8 = 318 B.t.u.
from each pound of steam into work, 2546.56 being the
equivalent in B.t.u. of a horsepower-hour. Steam of 215
lb. absolute pressure superheated 100 deg. contains 1259
B.t.u. per lb. If 318 of these were converted to work
there would be
1259 — 318 = 941
left. The heat of the liquid at 29 in. vacuum, or 1-in.
pressure is about 47 B.t.u., which leaves
941 - 4< = 894
for latent heat. As tiie latent beat of dry-saturated
steam of this pressure is 404? the quality would he
897 -r- 4047 = 85 per mil.;
thai is, lor the actual ease there would be something
like 15 per cent, of the steam already condensed when it
came to the condenser instead of the twenty-odd per cent.
of the perfect turbine, even including the effect of the
heat lost by radiation. It is expected thai the con-
denser will he installed and in operation during the
coming summer.
Impeller
Fig. 6. Showing Action of Turbo Air Pump
Showing Arrangement of Tubes and Steam
l'\s SAGES
For the above information and use of engravings we
are indebted to Sargent & Lundy. of Chicago, consulting
engineers to the Commonwealth Edison Co., and the
Wheeler Condenser & Engineering Co., Carteret, N. J..
manufacturers of the apparatus.
How Germans Have Crippled French Industrv — Dr. Schrod-
ter claims, in a recent issue of "Stahl und Eisen " that
although the French territory occupied by the Germans is
less than 1 per cent, of the total area of France, it contains
24.8 per cent, of the steam boilers in number, and 43 per
cent, in capacity, for 11 of the principal industries the boilers
used by which have been shown in recent official reports
478
s
POWEB
itr& !L©w~
Vol. 41, No. 14
A Poweb contributor has written, asking if there
was not something unusual in the manner of controlling
the synchronous motor mentioned in the article, "Per-
formance of Low-Pressure Plant." in our Dee. 1, 1914.
issue. There is not. However, as many readers may be
interested to know how a synchronous motor is controlled
when driven by a low-pressure turbo-generator and belted
to the same jaekshaft as the engines which supply steam
to the turbine, the following, from the Jenckes Spinning
Co.. of Pawtucket, P. 1.. owners of the plant, will lie of
interest :
"The synchronous motor is belted to the main jack-
shaft, which is driven by the reciprocating engines. It al-
so runs in parallel with the low-pressure turbo-generator.
The turbine is really of the mixed-pressure type, and when
first installed the main or high-pressure valve was hit
open to he operated by the governor. Much difficulty
was experienced with the regulation and it occurred to
the owners to shut this valve, so that the turbine would
never get anything but low-pressure steam. Now, all
the governing is done by the governors on the engines.
The synchronous motor floats on the line. When the
load on the engines falls off and the turbine is not gett in-
enough steam, the load is made up by the synchronous
motor being driven as a generator, which, of course.
admits more high-pressure steam to the reciprocating
engines and more low-pressure steam to the turbine, and
the balance is again restored : if the reverse is true, or
the turbine is getting more steam than it can use. it drives
the synchronous motor which takes more of the load
off the reciprocating engine, which cuts down the sup-
ply of high-pressure steam and again restores the
balance."
lni©se<=
A convenient little contrivance for tightening clamping
wire about hose, such as is used around the power plant.
Pig. 1. Hose-Clamping Tool
Tightening the Binding Wiiie
Fig. 3. Ready to Tighten Binding Wire
is made by the Wieder Manufacturing Co., Warren. Ohio.
The tool consists of holder and handle and a slotted pin
in which a lever is fitted, Fig. 1. This pin fits in a
hole in the main part of the implement, which has a
slotted projection at the end for receiving the binding
wire.
The application is simple. The wire is placed in the
slotted end of the tool and bent around, the ends coming
about even. The device is then placed against the hose
and the loose end wound around the hose and passed
through the loop in the wire and the slot in the tightener
stud, as shown in Fig. 3. Then it is only necessary to
push the lever in the direction to tighten the binding
wire, and when tight bring the lever over to bind the
loose ends over the end, forming the loop, Fig. 2.
Remarks of the Secretary of Commerce — In passing on the
case of an employee who complained that he was required to
do work beneath his position in the Department of Commerce,
Secretary Redfield said:
Tou may understand it as my views grenerally in matters of
this kind that I do not know what the kind of work can be
which is beneath any man's position. I think there is no
work of which I know or have heard that it is beneath my
dignity to do, and I am glad to say that I have done the
plainest and hardest and. what is sometimes mistakenly called,
the most menial work, and am ready to do it again if there
is occasion for it. There is no man in the department that
ought not be willing to do any kind of decent and honorable
work whenever circumstances require it of him, and I know
of no work with either hands or head which is not both
respectable and honorable if done with the right spirit.
The "Storstad" and the "Empress of Ireland" — The action
of the Canadian Pacific Railway Co. against the former owners
of the Norwegian collier "Storstad" for the ramming and sink-
ing of the liner "Empress of Ireland" in the St. Lawrence is
before the Admiralty Court, Montreal. Originally the claim
was for £400,000, but this has now been increased to £600,000,
the additional £200,000 being, it is understood, to cover actions
for damages by loss of life, either on the part of the relatives
of the crew under the Workmen's Compensation Act or other-
wise. The "Storstad" was sold for £35,000, which was paid
into court, and this amount will be available for, and dis-
tributed among, all those who substantiate their claims to it.
.The Mersey Commission fixed the onus of the Blame on Chief
Officer Tuftness, of the "Storstad." — Exchange.
April 6, 1915
POWER
479
BDdlitoffisdls
Air&©(Uh©2* Tsriilbtiaft© ft© Eira^lini©©^®
?mm©sa
One of the chief lessons thus far taught the world by
the European war is the importance of speed in naval ac-
tivities. More than ever before in history, a difference of
a very few knots in the ability of a war vessel to cover a
course is counting in the final outcome of conflicts on the
sea. Nothing less than speed enabled the now famous
"Emden" to pursue her career; speed permitted the
"Dresden" to escape so long after the battle off the Falk-
land Islands; and it was this quality again that so
prolonged the destructive mission of the "Karlsruhe."
Lack of speed prevented the old-style battleship "Canopus"
from joining Sir Christopher Cradock in time to avert the
disaster off Coronel, and it was speed primarily that en-
abled Admiral Sturdee's squadron to crush that of Von
Spee immediately after reaching the Falklands.
rbe value of being able to make twenty-eight knots per
hour instead of twenty-four has been demonstrated by
the battle cruisers of both Germany and Great Britain in
the stirring encounters of the North Sea this winter, and
it needs no naval expert to put into words the bearing high
speed is likely to have any day upon events of supreme
historic interest on the ocean. Only a look beneath the
surface is necessary to disclose the importance of faithful
performance of duty on the part of the power-plant staff
afloat, and it is no discredit to the navigating officers or
to the men behind the guns to raise one's hat for a moment
in honor of the brave fellows of engine room and stoke-
hole on both sides of the combat whose devotion to throttle
and shovel, valve and slice bar, amid fearful and unseen
perils, is powerfully helping to decide the issues in the
greatest struggle known to history.
]Relsiftioims ©ffttlra© C©irasiiaMiin\§£ asadl
&lh\e 0-p©irsiftlimg ELirsjipiraeea*
A large part of the work of a consulting engineer
consists of analyzing conditions in isolated plants, test-
ing their equipment, and advising their owners what to
do to improve the service. Often be is called on the ad-
vice of the operating man ; more often he is not. To have
another step in and tell you how to conduct your own
business, especially if he is retained without or against
your advice, provokes resentment. But this attitude is
becoming less general. Often, the man who protests most
about the intrusion of the specialist (in our case the
consulting engineer) feels that exposure of his weak-
nesses is imminent, and of course fights against it.
Consulting engineering, like other professions, has its
quacks and fakers. But this kind of man soon gets a
reputation that does not help him to do more business
or to hold the approbation of his fellow engineers. The
work of the consulting engineer brings him in contact
with a variety of conditions and things which, together
with his technical training, give him opportunities to
gain experience that the operating man cannot hope to
acquire. It is mainly this difference of training which
distinguishes one from the other. If it were possible
for operating men to receive such training, there would
be need of but few consulting engineers.
The chief cause for the ill feeling that so many oper-
ating men have for consulting engineers is not merely
because one operates and the other advises and plans.
Most power-plant engineers appreciate the professional
services of consulting engineers, but are too often sus-
picious of their presence because of petty things expe-
rienced or heard about. For example, a consulting en-
gineer may advise that the present engineer be displaced
to make room for a friend of his own. Sometimes, this
course is necessary in order that the work which has been
done, or is to be done, may be properly carried on.
A man who has been placed in his position by a con-
sulting engineer sometimes feels that his employer is
having unnecessary work done on the advice of the con-
sulting man, or that the latter is charging an exorbitant
price for his services for certain jobs. He is under
obligation to the consulting engineer who got him his
job, and rather than incur the displeasure of his bene-
factor by informing his employer of his suspicions, he
drugs his conscience with the conclusion that the em-
plover has money enough to stand it and, after all, no
real harm has been done. These cases, we hope, are
rare.
It is difficult for most operating engineers to judge
of the equity of a charge for consulting work; also,
without full knowledge of the work planned, it is not
always easy to decide that unnecessary work is being
done. The engineer who feels that such conditions
exist in his plant should acquaint his consulting en-
gineer with his opinions and thus satisfy himself whether
he is right or wrong. Otherwise, a decision arrived at
by snap judgment might cause him to lose not only his
friend but his job.
A consulting engineer should not make a big ado
about reducing the labor force in a plant when the good
to follow will soon be offset by losses due to neglect
because of a shortage of labor. Little mistakes of this
sort sometimes lead to long disputes with labor unions
and involve more than a commensurate amount of worry,
time and money. Then again, it must be acknowledged
that in some plants a reduction of the labor force is
justified and often proves a benefit to those laid off,
because in new positions they can develop their useful-
ness to a greater extent than would be possible in posi-
tions where time killing was the chief occupation.
Operating men sometimes accuse consulting engineers
of playing into the hands of a central station. It is
difficult to believe that these alleged acts are numerous
enough to warrant as much attention as they receive in
some quarters. Usually, when a reputable consulting
engineer makes such recommendations, he does so be-
cause the condition of the plant, the owner's financial
180
POWE E
Vol. 11, No. 14
circumstances, and the power consumption all warrant
the use of purchased power.
When a plant has been allowed to deteriorate through
vcars of neglect, as some have, and chiefly because those
in charge did not sufficiently understand their business,
the blame for what eventually happens to it is, first,
the owner's, for hiring such poor service, and, second,
the engineer's, for not knowing enough of the art of
his calling to take care of his own interests.
Granting that consulting engineers are sometimes
guilty of malpractice, that some of them stoop to deeds
unbecoming a professional man, the conclusion is readied,
unwillingly, perhaps, that a great deal of the operating
engineer's troubles exist because he does not realize that
running a power plant today means more than it did in a
past well within the memory of us all. This condition
should not exist, for there are many channels open to
all for cheaply acquiring the knowledge demanded in
modern power-plant practice.
lEvifls of ILow BadldlnEti^
In spite of all that has been said and written against
these evils, slipshod methods in estimating and under-
bidding are as common as ever. Nearly every failure can
be directly traced to careless bidding and a total disregard
of overhead and suitable profit.
Bidding on heating worl still seems to be based on
so much per square foot of heating surface, and on plumb-
ing, so much per fixture installed. Such methods should
never be used except as a check upon a properly made
estimate, yet curiously enough, an ever increasing number
are still willing to try to make a living by these guess-
work methods.
To succeed, every business, great or small, must be
operated with a clear conception of overhead expense, or
calling it by a better name, the cost of conducting busi-
ness. This will vary slightly from year to year accord-
ing to the volume of business done, and should be careful-
ly obtained in percentage upon the cost of the volume done
over a given period. Past performance will usually serve
as a guide, to be used conservatively in ensuing opera-
tions.
Before any article is sold or any work entered upon, the
complete cost to the bidder should be known as nearly as
possible. First, one should find out just what material
is required and its cost, then add the percentage of over-
head. The labor required to do the job is the hardest
item to estimate accurately ; it is usually hard to get away
from the allowance of so many hours for fitter and helper
per fixture, and if cost cards have been properly kept of
previous work, this method is often adopted. It would
seem better to analyze each stage of the work and figure
on the mean speed oi the men. and then check the result
by the method mentioned, remembering always that it is
safer to over-estimate this item than to under-estimate it.
To the labor estimate should be added, as before, the per-
centage for overhead. The continued difference in bids
for the same job and the increasing number of failures
show the persistence of careless bidding.
Such ruinous competition works to the moral detri-
ment of the trade as well, inasmuch as the successful low
bidder, to come out whole if possible, is tempted to resort
to questionable methods in trying to heat the specifications.
This reflects on him by the constant disputes, the length of
time necessary to collect the final payment, and the knowl-
edge that he will not have a chance to get a rerjeat order
from that customer. Really successful bidders are known
better by the number of their old or constant clients,
whose good will is the best advertisement possible.
A little missionary work on the part of the technical
societies might do something to correct these unfortunate
conditions.
Tlhie MerM ©if Ilimdiavfldltujal I£inf©s°&
The ability to do work above the ordinary is not ac-
quired without special concentration and endeavor. This
is what may be called individuality. This characteristic
must be developed with several attendant factors if the
results are to be what the ambitious worker desires. The
expert craftsman of any kind needs that individuality,
for he uses his brain as well as his hands. For several
reasons this attribute is often highly developed in the
man who operates or works in the smaller plant.
There is an abundance of commonplace workers and
their position has become precarious, for they are in
danger of losing their individuality and power to rise
higher than their fellowmen. The man who operates a
plant of medium size need not fear being eclipsed by
the man who operates the big plant, for in the latter,
individuality may be smothered in the volume of work.
All depend- upon the man himself; he must prove his
ability for higher-grade work. If his plant is small and
his workers few, he has the greater opportunity to show
his individuality. Where resourcefulness and work of
the higher grade are sought, one looks to the expert rather
than to the utility man.
The man operating a moderate-sized plant is better
able to realize his ideals. His operating costs are low,
he has only a small force, and his overhead expenses are
small. Given these conditions, if his service deserves
it, there are not the usual obstacles to his getting suf-
ficient remuneration to more than pay for his seeming
limited place in the industrial world. He can give such
attention to details that his work will be a source of sat-
isfaction and pride. It should be understood that he
must hire only such men as will become an inherent
part of his individual operation. This makes the gen-
ius, the man who has striven to rise above the ordinary
work, an eager worker, and one who can in this way
develop his latent powers to excel those who are in the
ruts of contentment.
With a limited number of machines and a power that
can l»e supplied at low cost, the operator of the small
plant has an opportunity to compel attention. Let him
specialize. There never has been a greater demand than
exists today for the specially expert. To gain recogni-
tion calls lor courage, concentration, labor and stability.
The man who shows these qualities, no matter how humble
his position, is bound to rise.
It is greatly to be regretted that Congress failed to
approve the two hydro-electric power bills before ad-
journment. This failure, of course, means that another
year of inactivity must pass before anything can he
accomplished. Meanwhile the mills are not grinding witli
the water that is passing.
April 6, 1915
POWER
481
iiiiiiii ! i..
:. mil ; iiii.il
C©rires]poini(dleiniC(
The illustration represents the packing-boxes on an
outside-packed pump, which was not satisfactory on ac-
count of leakage. This pump works on 150 lb. steam and
a vacuum of 25 to 26 in. When the packing is tight
enough to stop the leak the pump will labor and tremble
as if under a very high pressure. Is this due to the deep
packing-boxes? Each stuffing-box is 6 in. deep, and the
12 in. of packing, when tight enough to prevent leaking,
causes a great deal of friction besides the pressure and
vacuum duty.
My suggestion is to replace 2V2 in. of the packing-
box with a bronze ring made to fit the stuffing-box and
Silllllllllllllllllllliiiiiii mil ' iiiiiiiiliini ' inn iiiiiiii ii iiiiiiiiiiiiik
I have seen centrifugal pumps which were said to work
without priming over a suction rise of 6 to 8 ft. These
were only 5- or 6-in. pumps, delivering 1000 or 2000 gal.
per min. to a discharge rise of 5 or 10 ft. In my expe-
rience I have almost invariably had to prime centrifugal
pumps, and my experience covers several, from small ones
to 10- and 12-in. pumps throwing 4000 gal. per min.
to a height of 50 ft.
The tricks of priming were many. One of the easiest
was to let enough water from a storage tank flow back
to cover the blades of the pump, and then start, when al-
most invariably, it would pick up the load at once. There
was a check valve below the pump, which, of course, made
matters much easier than the conditions described by
Mr. Jones. He certainly used his wits in sealing the dis-
charge end with the revolving impeller beating the water
that remained in the discharge pipe, and then catching
the pump with enough vacuum from the steam ejector to
raise the water from the intake below the pump. It would
be interesting to know the maximum lift for which this
method of starting a pump with steam ejector would
apply, and still more so to know just how high this par-
ticular pump did work, for it is true, in my experience,
that such tricks as this of Mr. Jones' are comparatively
easy with small pumps, but become increasingly difficult
with increasing size of the pump.
The matter of the collapse of the discharge pipe, built
to stand 150 lb. internal pressure and failing under less
than 15 lb. external pressure, is also interesting, and I
hope that experienced pipe men will favor us with some
good common-sense explanation.
Charles S. Palmer.
Newtonville, Mass.
-—-_-- >■■
Proposed Bushing for Stuffing-Box
the plunger closely, but not tight enough to cause friction,
and to fill the other 3y2 in. with three rings of soft
.-qua re flax packing, thus reducing the total amount of
packing from 12 to 7 in. I believe this will permit us to
tighten the packing and stop the leaking and still allow
the plungers to work freely. I have reduced the number
of rings on other pumps from four to two and found that
they work better with less power. The packing lasts just
as long, and the lining lasts longer than when four rings
were used.
Charles E. Sherman.
Manasquan. N. J.
The article in the .Mar. '.' i>sue. page '."J I. mi "Priming
a Centrifugal Pump," by J. F. Jones, is interesting.
Many wrould like to know more of the details of this
unique installation, accident, and repair. In the first
place, will Mr. Jones tell how far above the lower water
level the pump was and how high the water had to be
elevated to reach the irrigating flume ? I suppose the di-
mension of the pump (30 in.) refers to the diameter of
the suction and discharge pipes : and this and the capacity
(25,000 gal. per min.) stamp the machine as belonging
to the class of large pumps. Will Mr. Jones also tell
whether he had any trouble with the side thrust from the
unbalanced condition implied by the use of one feed pipe?
The principle of priming this pump, though a rather
large one, should apply to smaller pumps, with which we
have all had our troubles.
The report on the condition of the plant under the care
of J. C. Hawkins, in the Feb. 16 issue, is interesting and
instructive. It also tends to develop enthusiasm, and
this alone helps more than anything else to maintain high
efficiency in the plant.
The questions in the "New Years Letter" (Jan. 19
issue) cover nearly everything, but a few more might be
asked :
1. Is the coal-storage pit moisture-proof ? If it is not,
much time and labor are lost from too much moisture
in the coal.
2. Is the distance between the storage pit and the fur-
nace as short as possible? If not, there is a further loss
in time and labor, also wear and tear on extra machinery.
3. Is the percentage of the redeemed waste heat, that
is. the heat in the chimney gases and in the exhaust steam,
high or low ?
4. Have we all the tools necessary for emergencies?
If we have, the length of shutdowns will be minimized.
5. Are we using the right grades of cylinder and ma-
chine oils?
482
POWER
Vol. 11, No. 14
6. Is all the lubricating oil handled without waste —
the proper quantity in the right place at the proper time?
7. Are the suction heads on the hoiler-feed pumps
right to allow the pumps to operate economically ? And
are all the pumps operated at the speed conducive to a low
percentage of slip? '
s. Is the friction horsepower of the plant as small as
possible?
Samuel L. Robinson.
l'ni\ idence, R. I.
IMocl&ainijg
It is to lie hoped that none of the readers of Power
who operate engines will blindly follow the reasoning
in the letter under the above title on page 347 of the
Mar. 9 issue, without proving for himself what the effect
might be under the various conditions that could arise in
the operation of the plant. It will probably not add to
the store of knowledge of the average engineer to tell him
that the governing of a single engine in a plant where two
or more are operating, could he dispensed with provided
the load on the plant were always to be more than the
maximum capacity of the ungoverned engine and the
transmission means between the engine and the load could
be depended on to be always in order.
The writer is not an operating engineer and does not
want to pose as having superior knowledge in regard to
■ power-plant operation, but unless street-railway power-
plant practice has changed remarkably in the past fifteen
years, it would seem foolish to say that anyone could
guarantee a fixed load for any specified interval during the
period of peak loads, when the circuit-breakers are apt
to be most active. About fifteen years ago I had some
experience in street-railway operation as an engineer, and
at peak-load periods had to block the governors on some
of the engines to prevent them from dropping. I was an
uneasy individual until the load decreased sufficiently to
allow the governor-blocking devices to be removed.
If any engineer is forced to operate under similar
conditions, even for a limited time, I would advise him to
lie just as uneasy. If a governor on an engine should be-
come deranged through the breaking of a belt or from
any other cause, he should quickly stop it until repairs
are made.
There is no class of power plants, as far as the expe-
rience of the writer goes, where the load is so likely to be
^•hanged from maximum conditions to no load at all, as in
street-railway power plants, and if any reader intends to
operate such a plant with the governors blocked, as a
steady practice, it might be well t(, block the circuit-break-
ers, so that they also would be inoperative.
While it is a criticism based purely on snap judgment.
the method of applying steam below the dashpot piston
of the average governor equipment would not seem to be
practical. In the first place, one would -expect that when
this device operated, the engine room would be showered
with oil from the dashpot. and also, that if the piston
were as loose fitting or had the area of holes through
it usually required to make the operation of the dashpot
satisfactory, a %-in. pipe could hardly he expected to fur-
nish a sufficient volume of steam to insure the raising of
the governor weights.
However, a- stated above, this criticism is not based
on actual experience with the device, but since the force
of gravity can be had in unlimited quantity and is some-
times used as a pdot to cause the operation of the de-
\ ice as described, it would simplify the apparatus to omit
the steam connection and allow gravity to do all the work
through a suitable arrangement of levers.
J. E. Term an.
New York City.
m
\UimSiftow ©if vUm\§v°IPl©w
Referring to the editorial on page 201 of Powee, Feb.
0, 1915, 1 should like to add to the discussion the results
of a little research on my part.
If you will turn to your Latin dictionary, "Andrews"
Latin-English Lexicon,"' for instance, you will find :
"Una" (adverb) = in one and the same place, or at the
same time. This seems to be the only form of unus which
has a distinct sense of same. It seems to me that this would
make the spelling "una" more nearly equivalent to the
C4erman "gleich."
The hyphen in una-flow seems to me essential in view of
the fact that the use of an adverb would imply that the
word "flow" had the strength of a verb.
If the above does not entirely supply the "more subtle"
or logical reason for calling the engine by the name "una-
flow,"' which Mr. Alexander finds lacking, we at least are
willing to take the additional trouble which the unusual
way of spelling entails in view of its advertising value
as a unique (unaque) form.
Charles C. Trump,
Stumpf Una-Flow Engine Co.
Syracuse, N. Y.
35
Some erecting engineers use iron chips or filings and
ammonia water, instead of cement or sulphur, for grout-
ing under machinery.
This grout does not set like cement and its action is
different. After the ammonia water evaporates, the filings
rust quickly and combine into a mass that is about as
difficult to chip as cast iron. The engine or other machine
is held up on wedges until' the filings are hard, and the
wedges may then be removed and the holes filled in with
the same material.
S. F. Wilson.
New York City.
Referring to the article on this subject by T>. N. Mc-
Clinton, on page 310, in the issue of Mar. 2, he states that
it is a matter of considerable discussion whether the level-
ing wedges should be left under the machinery perma-
nently. Prom a number of years' experience in erecting
engines. I would strongly advise never to leave them in;
furthermore, they should he taken out before the grouting
has set hard.
A method that I practiced with good results during
the last few years of construction work, was to set the bed-
plate on four wooden blocks a trifle higher than the po-
sition desired ami (lose to the anchor bolts nearest to the
balancing point of the two ends of the bedplate. Then
these bolts were pulled down until the proper height and
level were obtained; the wooden blocks would squeeze
April 6, '1915
POWER
483
enough for this. Then the tension on the holts was re-
tnoved and the grout was poured in. I found that one part
cement and two of sand made the hardest and most lasting
grout. When the cement is hard the wooden hloeks will
give enough so as not to interfere with the proper tight-
ening of the machine to the foundation, but iron wedges
will not. Balancing the bedplate at the two heaviest
points eliminates much of the danger of springing.
One of my early experiences in the erecting field was
replacing a broken shaft of a vertical-engine generat-
ing set that had been installed less than two years. The
old shaft was removed ami no apparent cause for its break-
ing was discovered at that time. The new shaft was put
in place and the engine reassembled. When about to re-
place the outboard-bearing pedestal it was noticed that
the engine and shaft were low. As new bearings were put
in with the shaft, it was at first thought that the upper
shells were not of the same thickness. These, however,
lined up all right. The engine was then raised from the
bedplate and it was found that the outboard-bearing end
was Z9/g4 m- higher than the engine bed. When the bed-
plate was raised and the old grouting removed, an iron
wedge was found driven tight under the part on which
the outboard-bearing pedestal was set. No other wedges
were found, showing that an inexperienced erector in level-
ing the outfit had used the generator end of the shaft
for a leveling point and had driven the wedge under the
small end, springing it up until the shaft showed level.
It was surprising that the shaft ran so long without break-
ing. This incident occurred about eleven years ago, and
the shaft then put in is still doing duty.
L. M. Johnson.
Emsworth, Perm.
discharge path, but are arranged so that this
shunt with the whole or part of the resistance II. In
other words, the discharge path from the line i- through
the gap B and resistance A' to ground. After the ab-
normal potential has broken down the gap B, the direct
dynamic current follows and the field is built up by the
coil S which blow- the an- J! from it- normal path and
extinguishes it by virtue of its elongation.
V. E. Goodwin.
Pittsfield, .Mass.
ILeaiEs^ Vsilv©® nim &. Water
In a certain mining camp receiving its gravity water-
supply under a 400-ft head, the valves of the hydrants,
about 200 in all, were cut by grit in the water after a few
weeks' service. A tank was placed at a point about 30
^1 Overflow
Pressure 174 /b.
Tank and Float to Control Pressure
[©dies' mi
Hffl\!3> Al?ff>©Sft©lf,§
I have read with interest. "Modern Lightning Arres-
ters," by Charles C. Raitt, in the Dec. 22 issue. The article
gives an excellent review of the subject, together with cuts
of modern types of arresters, but I would like to call
attention to an error in Fig. 11, which is a diagrammatic
sketch of a magnetic blowout type of arrester for direc-
ft. above the highest hydrant. The water was allowed to
flow into the tank under the control of a float-operated
valve and thence into the distributing system, as shown
in the illustration.
High pressure for fire protection was provided for by
closing valve A and opening B.
H. if. Howell.
Los Angeles, Calif.
Magnetic Blowout Type of Akeester (Fig. 11)
current circuits. The sketch as published shows the light-
ning-arrester discharge path passing through gap B,
through coil 6', and to ground through the resistance R.
One of the fundamental principles of lightning-arrester
design is to eliminate inductance from the discharge path,
consequently the magnetic blowout-type arresters as act-
ually designed do not have the coil 8 in series with the
<G©odl Ts^e^tomeiatl,, G©©dl Setf^nce
The human, man-to-man treatment of firemen is being
successfully applied at the Mechanical Rubber Co., Cleve-
land. In short, the firemen at this plant, in the words of
the operating engineer, George Lowe, "cannot be driven
from their job-."
The plant contains three hand-fired and three stoker-
fired boilers, ranging from 220 to 120 hp. The men are
paid a bonus on the CO, — 20c. bonus per 10-hour shift
for 9 per cent., 30c. for 10 per cent., 40c. for 11 per cent.,
60c. for 12 per cent., and 75c. for 13 per cent, The last
figure is frequently reached.
The men have been provided with arm chairs in the fir-
ing room and a shower bath near-by. "I believe we are
-iii i essful with our firemen," says the chief engineer,
"because we treat them as men and place them on their
own responsibility. There is no question of driving them.
Thev work as if they had an actual financial interest in
the success of the plant, as indeed they have."
This attitude toward the firing force is only a reflec-
tion of a general spirit of progressive efficiency through-
484
PC) WE I!
Vol. 41, No. 14
out this plant. In the past year or so. by the application
of the system mentioned and its resultant increase in effi-
ciency, by installation of other stokers under the thin
stokered boilers, which enables them to burn coal at $1.85
in-trad of at $2.40 per ton. and by the installation of a
station ash conveyor eliminating live ash wheelers at
$2.50 per day. this power plant has saved over $18,000 per
year net.
E. W. Waldron.
New York Citv.
The vapor pipes from return tanks, blowoff tanks and
open heaters should each extend separately through the
roof; otherwise, blowing down the boilers may cause a
back pressure on the other tanks. Where separate lines
are impractical, check valves on each line joining the
vent from the blowoff tank will prevent back pressure,
but they will cause a slight resistance, due to the weight
of the check. Such check valves should be so located that
no condensate can accumulate above them, because it will
tend to hold the valve closed and may at some time freeze.
All outlets such as those from feed-water heaters should
empty into a funnel in order to make noticeable any ex-
cessive waste of water to the sewer.
T. W. Reynolds.
Mt. Vernon, X. Y.
Referring to the description of a "Xew Series Trip for
High-Voltage Oil Switches"" in the Mar. 2 issue, I would
say that we have such a switch installed on a 60.000-volt
circuit.
We found that the wooden rod running from the relay
to the trip coil on the operating lever was of such small
material that it buckled under action and made the switch
late in opening, so that the switches on the low-tension
side of the transformers opened first.
This was remedied by putting an ordinary tube insula-
tor half way up the rod, thus preventing it from buckling
in the center.
J. P.. Crake.
Duluth. Minn.
Paiira&s ifos° E.ia§>iiinie@s3]iiag> ]?®ff]poses
In your issue of Feb. 16 appears an article by E. W.
Percy, entitled ''Paint for Engineering Purposes." To
some of the assertions made in this article I believe any-
one with a technical knowledge of paint and painting
would feel impelled to make objection.
I find myself at variance with Mr. Percy's statement
that pure white lead and boiled linseed oil are unequaled
for purposes of protection. As a matter of fact, I am sure
that there are many combinations that are better. Even
for white work many believe that white lead is improved
for protective purposes by the addition of other pigments.
Be that as it may for white paint, there are at least half a
dozen colored pigments that protect better, last longer,
and cost less than any white paint.
The usual substitute for white lead is not zinc, but
barytes. The zinc is used to give a good color and,
when lead i- also used, to improve the wear of the latter.
Whether it does this or not is a subject of controversy,
but I am convinced that it does.
Red lead is not "cheaper than"" white lead, hut much
dearer, because it rovers less surface, pound for pound.
It does protect steel excellently — but "there are others."
Mr. Perry is sadly "off"' in his varnish technology.
Varnishes are usually made with fossil gums (resins and
not rosins) that were once tree gums, as Mr. Percy states,
but which probably have not been in contact with a tree
since man appeared on the earth.
Amy] acetate is the orthodox solvent for pyroxylin. I
quote from Worden a typical lacquer formula :
L.acquer, Thinner,
Ounces Ounces
Pyroxylin 5.5
Amyl acetate 45 40
Refined fusel oil 7 6
Wood alcohol, !<7 per cent 24 35
Benzine, 62 &eg 32 20
Benzine, 71 deg 20 27
"Metallic Paints,"' by long established usage, are cer-
tain iron-oxide paints made either by grinding native
hematite ores or. indirectly, by roasting certain native
ores until the iron content is completely dehydrated and
converted into ferric oxide. They are red or brown in
color. The type of paints to which Mr. Percy refers are
known in the trade as bronzes.
The copper paint used on ships' bottoms is usually the
oxide or finely divided metallic copper (copper scale).
G. B. Heckel.
Philadelphia. Penn.
£2
In a plant in Pittsburgh we have five vertical water-
tube boilers, each rated at 310 hp., working 24 hi. a
day at 25 per cent, over rating. After the use of graphite
for some two months we found it necessary to open these
boilers about once a week and inspect them by running
a light through each tube, as the scale was coming off
in such quantities and in such large pieces that it was
liable to block some of the tubes and interfere with the
circulation. After using graphite four months, our boilers
were clean and free from scale. Before using it we were
compelled to clean them completely every six months and
the front bank of tubes every 30 days. This was
expensive, as shown by the following figures. When we
were cleaning the boilers with an air-driven turbine it
cost about $1300 a year, besides having them out of
service from 30 to 60 days each year. Since we have used
graphite it has cost us about $475 a year, and we have
the use of the boilers continuously.
When we started to use graphite we fed 3 lb. per 100
hp. per day of 24 hr., and after the boilers were clean
we cut down the amount to l*/; lb. per 100 hp. per day
of 24 hr. Every time we wash out a boiler, which is
every 30 days, we put 3 lb. of graphite in the rear
steam drum.
John L. Armstrong.
Pittsburgh, Penn.
8
Mr. Wentworth's discussion of "Oil Engine Tend-
encies" in the Mar. 16 issue, page 383, contains the state-
ment : "I have demonstrated that for a running engine
150 lb. is sufficient to ignite the fuel, the hot plate being
needed only for starting in the engine which I have de-
veloped." The latter part of this sentence should have
read : '"The writer has developed a type of engine not lim-
ited in size and which nerds no hot plate." — Editor.
April 6, 1915
PO WER
is;,
A Gas©Mi?&©»I£iragg5nae TesH
The accompanying curves show the results of a brake
test on a 10-hp. gasoline engine, made to determine the
cost per brake horsepower per hour under different loads
and, incidentally, the regulation under these loads. The
gasoline pump was disconnected and the gasoline was fed
to the vaporizer by gravity from a 5-gal. can provided
with a nipple and cock; the flow being regulated so that
only a small amount appeared at the overflow. This was
Srake Horsepower
Regulation and Cost Curves
collected and poured back into the supply can, which
was weighed at the beginning and at the end of each
run. The revolutions per minute were taken almost con-
tinuously by speed indicators and the average readings
were used in the calculations. Each run was of 30 min
duration, which, although not long enough to obtain ex-
tremely accurate results, was sufficients accurate for the
purpose. The cost is based on gasoline at 15c. per gallon.
R. S. Hawley.
Golden, Colo.
OgiaSfte aim D©©p F^ui2»n&&ce
A plant owner purchased two 72-in. by 20-ft. high-
pressure tubular boilers to be erected in the West. One
of them was to be equipped with shaking grates, the other
with a special grate and furnace using forced draft
through a sealed ashpit and also through a hollow bridge-
wall. This type of furnace had been successfully installed
in other plants using Wyoming lignite, the coal to be
used in the new plant. The advantage claimed for the
special furnace was the admission of enough air through
the fuel bed to burn it to CO, which, rising above the bed,
mixed with the warm air entering through the hollow
bridge-wall and burned to CO,.
In arranging the details of the plate-steel boiler fronts,
the contractor's representative noted that the special fur-
nace required a height of 54 in. from grate to boiler. This
required the boiler to be set much higher than usual -
BO to make the fire-doors of all boilers the same distance
from the floor, he raised the second boiler so that the
furnace height was also 54 in.
Test runs on both boilers were conducted and the
boiler with the special furnace showed an evaporation of
5.2 lb. of water per pound of coal, and the efficiency was
roughly, 67 per cent. The other boiler, equipped with
shaking grates, under like conditions, gave but 2.5 lb
of water per pound of coal, the efficiency being approxi-
mately 331/3 per cent. The result was so much lower than
that attained in the old plant, where plain grates were
used and the boiler walls badly cracked, that the owners
entered an emphatic protest.
Since the type of shaking grate was a good one. Hi,
s,-"'k I'M1'"") •nnple and the setting air-tight, it was
conceded that the trouble lay in the extreme depth of
the furnace. Luckily, the steel front was so sectionalized
thai the fire-door could be raised along with the grates so
that the furnace depth would be made 26 in. instead of 54.
This was done and on a second test an evaporation of
4.45 lb. of water per pound of coal was obtained. This
value is good for shaking grates using lignite that slacks
badly and that causes an appreciable loss of fuel into the
ashpit. Perhaps the cause was that the lignite gave a
short flame and the great depth of the furnace allowed
too much air to come in contact with the burning gases.
L. H. Morrison.
Dallas, Tex.
[If the setting was air-tight above the grate the addi-
tional height of the furnace should have given good in-
stead of poor furnace efficiency. — Editor.]
it
EMag>©inmIl J©nirats
The efficiency of a diagonal seam is a matter of angles
and should be calculated for each different angle. J. E.
Terman, March 2 issue, p. 296, compares the strength of a
diagonal joint in a testing machine to a longitudinal joint
of a cylinder. To take another view of it, let us compare
the diagonal with a girth seam. That there is an additional
strain in a diagonal joint in a boiler not exerted in a test-
ing machine is pointed out by Mr. Terman. There is a
generally accepted statement that the force tending to
rupture a cylinder girthwise is one-half as great as 'that
tending to rupture it longitudinally. This is equivalent
to stating that the effective efficiency of a girth seam is
twice as great as that of a longitudinal seam of like-
design. This can easily be shown mathematically, and
the relation is so apparent that tests are not necessary
to prove it. The relative strength of a diagonal seam
compared to either a girth or longitudinal joint can be
calculated, but under test conditions do not apparently
come up to expectations.
As an illustration, consider a single-riveted diagonal
seam to hold a patch. Suppose the single-riveted 'seam
has an efficiency by test of 50 per cent, of the solid plate.
It will then have an efficiency of 50 per cent, as a longi-
tudinal seam and a comparative efficiency of 100 per cent.
as a girth seam. A diagonal seam of the same proportion
will have an effective efficiency somewhere between these
two values, decreasing as it swings from the girth seam.
If a section of the diagonal joint were tested it would
probably fail at less than 50 per cent. The inclination
is to jump at the conclusion that the diagonal seam is
weaker than the longitudinal and that the calculations
on the strength of diagonal joints are in error. A little
further consideration of the matter shows that the test
of the straight joint showed 50 per cent, and no more,
yet with this joint in another position it will be, relatively!
twice as strong.
If, then, we compare the strength of the diagonal seam
to a girth seam instead of to a longitudinal seam, as has
been the practice, we will approach nearer to the calcu-
lated efficiency for a diagonal joint. The test efficiency
will show higher than calculated, and the error will
increase as the diagonal joint deviates from the girth
joint. This comes about because in the machine there
is a pull in one direction, while in a diagonal boiler joint
4S6
POWEE
Vol. 41, No. 14
there is an endwise and longitudinal pull combined, and
until a testing machine is made that will pull in the two
directions at right angles to each other, the result of
tests along a diagonal line will not give very accurate
results.
Thomas Grimes.
Houghs Neck, Mass.
In calculating the strength of a diagonal scam it is
necessary to take into consideration the well known fact
that internal pressure exerts twice the strain on the
longitudinal scam or section of the sheet as on the girth
scam or sheet section. In Fig. 1, AB represents a longi-
tudinal seam, CD a circumferential seam, and EF a
diagonal scam. Since the strain on a longitudinal seam
AB is twice that on a girth seam CD, it is evident that
C
F
B
" .
' o
E
^1_.
D
k
— x
J
Fig. 1.
FIG. I.
Eelative Position op Seams
the smaller the angle a, the greater the internal pressure
a given diagonal seam will withstand.
Now, the force acting on a unit of length on a diagonal
seam EF is the component of the girthwise and longi-
tudinal stresses. In the three
types of seams suggested,
with the plate, size and
pitch of rivets the same, the
efficiency of the seams will
be identical, but the inter-
nal pressure they will with-
stand will depend on the di- FIG.2.
rection of the seam with Fig. 2. Calculation of
reference to the axis of the Efficiency of Diag-
eylinder. onal Seam
P = the bursting pres-
sure of the cylinder through the solid sheet and if E =
the efficiency of the joint, the bursting pressure through
the joint AB, Fig. 2, will be PE.
From this is derived the formula
AC-
^ dUc
i?Vl — 3sin*a §Vl — 3sin2a
effective efficiency of diagonal seam, and from it a table
of constants may be calculated.
The effective efficiency of the diagonal seam may be
determined from the formula
EE =
h V 1 + Bsin*a
where
EE = Effective efficiency of diagonal scam:
E = Efficiency of ioiut calculated as a longitudinal
seam ;
a = Angle made by girth seam and diagonal seam.
With a table calculated from the formula, and by its
use E and a being known, it is only necessary to divide E
by the required factor to determine the effective efficiency
of the diagonal seam; or, the efficiency of the longitudinal
seam being known, to lay out a diagonal seam of equiva-
lent efficiency at a given angle, multiply the efficiency of
longitudinal seam by the factor corresponding to the
given angle. The product will be the efficiency of the
joint at that angle. In repair work we can calculate the
efficiency of the longitudinal seam, assuming the highest
efficiency E practical for the seam in the patch. Dividing
the first into the second will give the greatest angle at
which the effective efficiency will equal the longitudinal
efficiency.
E. D. Ievington.
Boston, Mass.
Plpaiagl BtmfofolleE'S t© Av©£dl
Of all inefficient things, a bubbler drinking fountain
seems the most wasteful. 'When, as boys, we used to lie
down at the edge of a brook to drink, we did not think
of the brook as flowing for that express purpose, but
when we open a bubbler valve the flow is solely for the
sake of getting a drink, and we consume about one per
cent, of what flows and waste the rest.
We think of the installation of a drinking fountain as
a plumber's job. A plumber will tell you at once that
any waste pipe must go into the sewer. The water that
has gone by one of these bubblers is just as good to feed
the boilers, flush the closets, or for any mechanical pur-
pose as it ever was.
The waste pipe can be made to discharge into an open
tank or into the return tank of a vacuum heating system
and thus improve the vacuum because the water is cold.
There should be an effective check valve in the line so that
hot water cannot back up into the bubbler. This is es-
pecially necessary if the drain pipe surrounds the feed
pipe for a short distance. I know of a case where the
water in the bowl which had backed up heated the supply
pipe enough to scald a man by the first rush of water.
It is better to discharge into a separate tank from which
the water can lie pumped wherever desired, and in that
way prevent waste.
E. F. Henry.
Worcester, -Mass.
With high steam pressure and superheat there is likely
to be more or less trouble when making repairs, on ac-
count of leaking stop valves on the sections of headers
which have been cut out.
In some plants it is the practice to cross-connect the
suctions of the dry-vacuum pumps. A convenient use
can be made of this connection when making pipe re-
pairs. If the section of the header cut out has a con-
nection to an engine or turbine, the throttle can be
opened wide, the inlet valves blocked open, the connec-
tion to the condenser opened, and the dry-vacuum pump
will then draw the leaking steam past the point of re-
pair.
Of course, the proper way would be to replace the
valves, but this cannot always be done. However, with
the bolts out of a flanged joint and the steam burning
the hands, the foregoing stunt will be found worth while.
John F. Hurst.
Louisville. Kv.
April 6, 1915
POWK R
4S1
Himqpuiiiries ©f (GeimejpsJ lEntterestt
iiiiiiiiiiiiiiiiiiiiiiiiNiiiiiiiiiiimiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiiiiiiiiiini mini iiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiin iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiimiiiiiiiiiiiiiiiiiim iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiinniiiiiiiniiiiiiiiiiiiiiniiiiiiiiiiniiiiiiimiiiiiiiiiiiiiiiiiiiiiiniiiiR
i rushing Strengrth of Boiler Plate — In computing the
strength of a boiler joint what is understood by the crushing
strength of the plate?
J. R.
The crushing strength of the plate is its ability to resist
distortion from the compressive stress which is incident to
drawing the sheet against one side of a rivet in exerting
shearing stress in the rivet.
Safely of Cracked Mud Drum — Would it be safe to con-
tinue the use of a cracked mud drum of a water-tube boiler
after drilling and plugging the ends of the cracks?
F. S.
The drilling and plugging might reduce the tendency of
the cracks to extend in length, but could not otherwise in-
crease the safety of the drum, which may not have sufficient
strength for safety even if the cracks do not extend.
Relative Heat Value of COj and of CO — What are the
relative heat values derivable from carbon in fuel burned
to CO: and to CO?
G. B.
When carbon is burned completely to C02 there will be
given off 14,500 B.t.u. for every pound of carbon burned, but
when CO is formed there are 4400 B.t.u. given off per pound
of carbon burned, or less than one-third as much heat.
Relative Lengths of Pump Cylinders — Why is the water
cylinder of a steam pump made longer than the steam cyl-
inder?
J. W. D.
So that there may be latitude in length of the piston rod
without the water piston overrunning or leaving too little
clearance in the ends of the water cylinder for the greatest
possible stroke of the steam piston in either direction.
Boiler Foaming; from Temporary Use of Good Feed Water
— How is it explained that the temporary use of a good qual-
ity of feed water causes a boiler to foam?
G. N.
Where a boiler is coated with scale a pure feed water
will sometimes dissolve the scale, leaving the metal bare in
spots which transfer heat much faster than parts that are
covered with scale, and the violent boiling over places where
there is little or no scale is likely to result in foaming or
priming.
Circulating: Pipe for Itlmvoff — How can a circulating pipe
be connected to the blowoff pipe of a return-tubular boiler?
R. C.
A circulating pipe of a size smaller than that of the
blowoff pipe can be connected from a point in the blowoff,
outside of the rear wall and on the boiler side of the blow-
off valve, to a point in the rear head of the boiler a short
distance below the water line. The circulating pipe should
be provided with a stop valve, which should be closed when-
ever the boiler is blown off, but at all other times should
be left wide open.
Per Cent, of Fuel Saved by Heating Feed Water — What
is the formula for calculating the per cent, of fuel saving
from the use of a feed-water heater?
A. S.
For practical purposes the heat saved in raising the
temperature of feed water may be regarded as directly in
proportion to the rise in temperature. The steam pressure
and feed-water temperatures before and after heating being
known, the fuel saving can be computed by the formula,
100 (t — to
Fuel saving in per cent. = ■ ■
H + 32 — U
in which
t = Temperature F. of feed water after heating;
ti — Temperature F. of feed water before heating;
H = Total B.t.u. above 32 deg. F. per pound of steam at
the boiler pressure (to be obtained from tables of
properties of steam)
Maintaining Air Supply in Air Chamber — How can a sup-
ply of air be maintained in the pump air chamber of a high-
pressure service pump?
J. G.
An automatic air pump for supplying the air chamber
may be provided by connecting a vertical 2-in. or 2% -in
pipe about 30 in. long, with a stop valve at its lower end,
to one head of the water cylinder and providing the upper
end of the pipe with a tee and Hi -in. check valve opening
inward and a %-in. check valve opening outward and con-
nected to the pump air chamber. For operation of the air
pump it is necessary that the pump to which it is attached
shall be in operation. To start the air pump, first open the
valve connected with the water cylinder to charge the air
pump with water; then partly close the valve until the check
valves begin to work.
Compression of Steam in Duplex Pump — How is compres-
sion of exhaust accomplished in the steam end of a duplex
pump?
W. Li.
Separate steam and exhaust passages are provided in
each end of each steam cylinder, the cylinder ports of the
steam passages being located in the extreme ends of the
cylinders or nearer the ends than the cylinder ports of the
exhaust passages. The exhaust ports are placed so near
together that before completing the stroke from one end
of the cylinder the piston covers the exhaust port at the
other end of the cylinder. When the exhaust passage is thus
closed, any exhaust steam then remaining in the cylinder
and steam passage on the exhaust side of the piston is com-
pressed by it during the remainder of the stroke.
Computation of Indicator Diagrams — An 8xl0-in. engine
having a 2-in. diameter piston rod runs at 200 r.p.m. The
indicator diagram from each end of the cylinder has an area
of 2.5 sq.in. and a length of 4 in., and the scale of spring is
50 lb. per sq.in. WThat is the i.hp.?
S. H E.
In each diagram the mean effective pressure would be
area 2.5
X scale of spring, or X 50 = 31.25 lb. n-.e.p.
length 4
The area of the 8-in. diameter piston being 50.265 sq.in. and
the cross-section area of the 2-in. diameter piston rod being
3.1418 sq.in., then for 10-in. stroke and 200 r.p.m., there
would be
10
31.25 X [50.265 + (50.265 — 3.1416)] X — X 200
12
— ■ = 15.37 i.hp.
Application of the Prismoidal Formula — What would be
the cubical content of a piece of timber 16 ft. long, 6x6 in.
at one end and 4x8 in. at the other?
T. E. H.
Assuming that the ends are parallel planes, as, for in-
stance, both square with one of the edges of the timber,
then the content can be found by the prismoidal formula
A + a + 4 M
Volume = L X
6
in which
L = Length;
A = Area of one of the parallel ends;
a = Area of the other parallel end;
M = Area of cross-section midway and parallel to the
parallel ends.
The ends being, respectively, 6x6 and 4x8, the parallel
mid-section would be 5x7, and the length being 16 ft., then
the volume would be
(6 X 6) + (4 X 8) +4 (5 X 7)
(16 X 12) X = 6656 cu.in.
r.r
66S6
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
JSS
P 0 W E T;
Vol. 41, No. 14
Nuithunre MetJhodls of UftMisnmiE
SYNOPSIS — Economic pressure due to increased
demand and cost of coal will force improved
methods of combustion and the recovery of the
carious byproducts contained. The relative costs
of fuel and capital are the determining factors.
There is no need for conservation as ordinarily
understood. Future generations, with their fuller
knowledge and wider vision, will be better able to
take care of themselves.
There is at the present day a certain amount of coal buried
in the earth's crust. Coal is being slowly formed at some
points on the surface of the earth, but the rate of formation
is so low in comparison with the rate of consumption that
for all practical purposes the supply available for human
consumption may be assumed to be that already formed. If
this view is taken, it is evident that the amount of coal which
can be used by man in the future is definitely limited; when
he has used up the coal now in the earth's crust, or that
part of it which he can extract, there will be no more avail-
able for use.
The estimates of the length of time which will elapse
before this condition is attained vary greatly, but most of
them allow humanity at least a few hundred years before
the exhaustion of all available coal. Opinions as to what may
happen when the time of ultimate exhaustion arrives are
equally variable. Some believe that humanity must perish
because of the enforced cessation of industries and because
of the impossibility of keeping warm during the cold seasons
of the year. Others believe that by that time hydro-electric
development will have been carried to such a point that elec-
trical energy will entirely take the place of heat derived from
coal. Still others are satisfied to let the future take care
of itself and to assume that the human brain is going to
be able to continue to devise methods of changing the environ-
ment to suit the needs of the human animal.
I am inclined to take the last view myself, as I believe
that the centuries of human history which are available show
that each successive generation has become better able to
force its dictates upon nature rather than to be subservient
to the unrestricted action of natural forces. In other words,
subsequent generations will be better able to care for them-
selves than the present generation and there is no need to
waste good time and effort in trying to solve their problems
for them with a smaller stock of knowledge and a narrower
vision.
In taking this viewpoint it is not necessary to hold our-
selves responsible to future generations for the use we make
of the coal stores which we are depleting at such a rapid
rate. We may consider ourselves free to use this material
as our industrial development requires, though we are, in a
certain sense, morally bound to make that usage as economical
as possible on the basis of the general principle that it is
not good economics to waste wealth of any sort.
If, then, we attempt to look into the future for the purpose
of predicting the methods which will be in use for the
utilization of coal, we must not warp our vision by an errone-
ous assumption of the necessity of conserving the supply.
We must rather study industrial developments of the past
and after discovering their general trend, attempt to apply
this knowledge to the particular field under discussion.
It has been characteristic of nearly all industries that they
started in a small way under conditions which did not require
the most economical production. Thus the shoe industry was
started by numerous individuals scattered over the country,
who purchased leather, nails, thread and other raw materials
in small quantities and then worked them up into shoes on
individual orders received from people living in the immediate
neighborhood. The modern packing industry sprang from the
small butcher who slaughtered for local consumption and
disposed of the hides and other byproducts in the easiest
way possible. The clothing industry was originally confined
to the home, the land or the live stock producing the raw
material, which was worked up by the family of the owner
into the clothing required by that family.
All of these industries have grown until they are scarcely
recognizable as the offspring of their forebears. This has
•Abstract of paper read by Prof. C. F. Hirshfeld before
the Detroit Engineering Society, Mar. 23, 1915.
been brought about by organization, which is merely the
combination of capital and the division of labor for the
purpose of producing the biggest possible yield from given
raw materials or natural supplies.
In the shoe industry scientific development produced the
marvelous machines which are now used in producing leather
and shoes and the railroads which later transport the factory-
made product to the scattered consumers.
In the packing industry the refrigerator car made possible
the concentration of the slaughtering industries and, coupled
with mechanical and chemical invention, assisted in building
up large modern plants.
Spinning and weaving machines, cutting, sewing and press-
ing machines, coupled with the railroads, have made possible
the huge centralized clothing industries of the present day.
The study of the packing business tends to throw consid-
erable light upon the probable future development of the coal
industry. It is not so many years ago that, in this country
at least, meat on the hoof was so plentiful that it could be
slaughtered in most expensive ways and still be sold at a profit
at such a low figure as to bring it "within the reach of prac-
tically all families. Conditions are now different and meat on
the hoof is comparatively scarce. It therefore brings com-
paratively high prices and if all or practically all of the
purchase price, transportation and slaughtering expenses had
to be borne by the meat and hide, the prices of these com-
modities would be so high as to put them beyond the reach
of many families even in this comparatively opulent country.
But the modern packing house manages to sell every part
of the animal for some purpose. Some parts, such as those
sold in the form of dressed meat, are disposed of after little
modification, 'while others, such as horns, hoofs and fat, pass
through elaborate manufacturing processes before they are
ready for the market. "When it is remembered that every
one of the numerous products is sold on the average at such
a price as to bear its share of the cost of the animal, of its
transportation, and its slaughter and dressing, it is evident
that the principal product, meat, can be sold at a lower price
than would otherwise be possible. Moreover, waste has been
reduced to a minimum; all parts of the animal -which cannot
be used for food are used for other purposes.
The coal industry, particularly in this country, is in much
the same position today as would be a packing house which
produced meat only. Coal is removed from the mine, put in
marketable condition "with the minimum possible expenditure
and shipped to the consumer. The greater part of it is burned
under boilers just as it is received or after breaking to
smaller sizes.
As the supply in sight in the ground decreases, as mines
become deeper and as freight rates increase, coal becomes
more and more expensive. This process must continue so
long as the methods at present in vogue in the industry con-
tinue and the cost of coal must ultimately become a serious
burden on industries in which the coal charge forms a large
fraction of the total charge. In view of what has happened
in other industries it is but natural to assume that when
economic pressure makes it necessary, the coal industry or
the methods of utilizing coal will be so modified as to obtain
the maximum possible number of products with the maximum
possible economic value from each ton mined, provided such
products are obtainable.
We are accustomed to think of coal as merely so many
stored or latent units of heat energy purchasable at so much
per thousand or million. It is far better, however, to view it
as a collection of chemical substances and combinations which
are capable of almost an infinite number of transformations
and recombinations to form innumerable new end products.
If coal were merely a collection of units of heat energy the
cost per unit would of necessity continue to increase until it
reached a prohibitively high value. Taking the view just
suggested, however, it is possible that chemical jugglery of
the constituents may be made to develop substances market-
able at such prices as to materially reduce the necessary sell-
ing price of units of heat energy.
The principal constituents of coal are carbon, hydrogen,
oxygen, nitrogen and sulphur, and these are the blocks out
of which innumerable organic and inorganic chemical com-
pounds are built. Just how these various constituents will
be liberated or recombined for the purpose of increasing the
economic value of a ton of coal in order that the selling price
of units of heat energy may be kept down to a reasonable
figure, must be more or less a matter of speculation. It is,
however, pertinent to note that processes of this kind are
already in use in some of the European countries and par-
ticularly in Germany, and it is reasonable to suppose that
April 6, 1915
POWEK
489
future development will follow along- some such lines as those
already partially developed. An investigation of these methods
may therefore assist in arriving at a more correct prediction
of future methods.
In general, development is carried on along three lines:
First, the thermal efficiency of heat engines and plants is
brought to the highest possible figure in order to reduce to a
minimum the number of heat units which must be purchased
by anyone concerned in the generation of power; second, by-
product fuels of various varieties are made from the raw
coal, or from the coal in the process of utilization and some
of these may have such desirable properties as to be worth
more per unit of heat energy than is the raw product. Their
use or sale therefore tends to reduce the price paid for heat
units in the raw coal. Third, many byproducts useful in
numerous arts are made and their economic value helps to
reduce the cost at which units of heat energy or their products
must be sold to yield a profit.
It will be observed that when the coal-mining and con-
suming industries develop in this way, they begin to approach
the condition of the modern packing industry. The capital
involved is enormously increased; many more kinds of labor
are required and the subdivision of labor is carried to a far
greater extent; and the economic value of the product per
ton of raw coal is enormously increased.
The parallel may be drawn still more closely. Meat for
human, consumption may be considered the primary product
of the packing industry. The selling price is continually
increasing, but the rate of advance is kept lower than it
otherwise would be by increasing the number of products
per unit of raw material, giving a greater economic value
to the products per unit and reducing the charges against
the primary product. Heat energy may be said to be the
primary product of the coal industry and the selling price
of this is continually increasing. The rate of advance is kept
lower than it otherwise would be by increasing the number
of products per unit of raw material, giving a greater
economic value to the products per unit and reducing the
charges against the primary product.
Development along these lines has thus far progressed
along two principal paths. The raw coal is subjected either
to a destructive distillation process with the exclusion of air,
or to a process of incomplete combustion in the presence of
air The former method yields a solid fuel called coke;
combustible gases of a more or less permanent nature; con-
densible vapors of great chemical and fuel value; and other
substances, such as ammonia, cyanides, sulphur compounds
and others. The latter method yields solid, incombustible
refuse or ash of comparatively small value; large quantities
of combustible gas of great value; condensible vapors which
are becoming of greater chemical importance daily and are
also becoming available as fuel; and small quantities of
chemical compounds of more or less value.
By such means as these fuel material becomes available
in solid, liquid and gaseous forms, and the particular variety
best suited to any use may be chosen therefor if price permits.
It is, of course, impossible to obtain more heat units than
were originally contained in the fuel. There is in reality
always a loss in these processes, but the thermal efficiency
with which the smaller number of resulting heat units can
be used may more than balance the thermal losses occurring
during the modification of the fuel. Great developments have
been made in the use of gaseous and liquid fuels during the
past few years. It is now possible to use such fuels for the
generation of steam, for industrial heating, and for the opera-
tion of prime movers at efficiencies much higher than seemed
possible of attainment a short time ago. Surface combustion
and the internal-combustion engine in its various forms are
pointing out lines of development leading toward constantly
increasing thermal efficiencies.
These statements must not be interpreted as an argument
for the immediate adoption of gas firing and of the universal
use of the internal-combustion engine. Other matters must
be given consideration as well as the cost of fuel. The cost
of capital is of equal importance.
At present the costs of capital and of fuel are both increas-
ing, but the cost of the latter is increasing more rapidly than
that of money. Even now the cost is such as to warrant
greater capital investment for procuring greater thermal
efficiency than could have been justified a few decades ago.
Ultimately the cost of fuel must rise to such values as to
warrant the investment of the necessary capital and the
training of the necessary labor to make possible the use of
fuel in such ways as to produce the greatest economic produc-
tion per ton of raw material.
When that time comes it is probable that coke, or some-
thing resembling it, will be the principal solid fuel; gases
formed during the production of the solid will be used in
internal-combustion engines, or by surface combustion, or in
ways not yet discovered; and liquid fuels formed during the
production of solid fuel will be used in high-efficiency, liquid-
fuel engines. Before they are used the liquid and gaseous
fuels will be robbed of many valuable constituents, which
will l.e used in producing fertilizers, medicines, paints, dyes,
preservatives, waxes, flavoring extracts, commercial chem-
icals and many other products yet undreamed of.
Summarizing these ideas, it seems probable that:
1. Improved or more economical methods of utilizing coal
will not and need not be brought about by any consideration
of conservation as ordinarily understood.
2. Such methods will be brought about by cumulative
economic pressure due to the natural operation of increased
demand for fuel combined with decreased quantities and
increased cost of mining and transportation.
3. When such methods are thus forced upon humanity
they will follow, in a general way, the course developed
in other industries under the force of similar circumstances.
4. These methods will consist of a preliminary treatment
of the raw material to produce fuels with different physical
and chemical characteristics which will adapt each form
to use in particular kinds of apparatus or in particular
industries.
5. Coincident with this treatment will be produced numer-
ous non-fuel byproducts of great value in the then existing
markets.
6. The spreading of the cost of the raw material over so
many products will prevent the excessively rapid rise in the
selling price of fuel per heat unit and this, combined with
high efficiency methods of utilization made possible by the
relative prices of fuel and capital, will yield the same sort,
of an economic balance as now exists. Humanity will prob-
ably then, as now, bemoan the fact that it could not have
lived several generations before, when fuel was "cheap," and
will probably express great sympathy for the coming genera-
tions that will have to face the problems of life with a still
more depleted coal supply.
Many will probably object that the cost of modifying coal,
as, for instance, by the destructive distillation process, has
always been so expensive that little is to be hoped for along
such lines in the future. In answer to such criticisms it is
only necessary to point out the fact that despite the rising
prices of coal, labor and capital, the selling price of gas
made by such processes has steadily decreased. It is admitted
that further decrease cannot be brought about by exactly the
same methods as have been used in the past, but it shows
very little faith in the progress of the human race to assume
that the present status in any industry represents the ultimate
development of which humanity is to prove capable.
Seedioir&o A. ^
[hit,, <CIhincsi.fi?©
The chief paper presented before the meeting in the Grand
Ball Room of the LaSalle Hotel, Mar. 19, was by Heywood
Cochrane, Western manager for the Carbondale Machine Co.
The subject was "Ice Making as a Byproduct for Central
Stations," a digest of which follows:
One point of difference between the electric-light and the
ice plant is that of distribution. There is hardly any limit
to the extent of the former, but the latter soon reaches a
size where the cost of distribution more than offsets the
saving. Individual plants of from SO to 150 tons, located
in the best centers of distribution, are preferable to large-
capacity plants adjacent to the station.
With condensing water under 70 deg. F. it is possible to
use exhaust steam at 3 lb. pressure in the generator of an
absorption system. This steam is condensed, furnishing a
portion of the distilled water required for making ice. About
55 to 60 lb. of steam per hour per ton of ice is required for
this purpose. With condensing water at 90 to 95 deg. it is
not possible to run on less than from 20 to 25 lb. exhaust-
steam pressure, because of the high condensing pressures
necessary. Such pressure would seem prohibitive, yet plants
operating under these conditions are proving economical. It
is not generally known that, properly designed, the absorp-
tion machine is an ideal installation for warm water condi-
tions. Just as it takes little more coal to carry 125 lb. boiler
pressure than it does 100 lb. (less than 1 per cent.), it takes
comparatively little more steam in the generator to produce
an ammonia pressure of 200 lb. than it does 150 lb.
An electrically driven compression plant will require from
43 to 70 kw.-hr. per ton of ice, depending upon its size and
local conditions. At lc. per kw.-hr. the power costs per ton
will usually average between 50 and 60c. From the central-
station manager's standpoint, in the larger cities, such as
Chicago, the privately owned electrically driven plant is the
490
POWEB
Vol. 41, No. 14
proper combination, while in smaller cities it is much more
profitable to own the ice plant direct.
It is possible in a properly designed compression and
absorption plant, say of SO tons' capacity, with a 20-ton
machine of the former type and a 60-ton of the latter, to
make ice at a lower fuel cost than 35c. In this case there
should be two 40-ton tanks, the compression machine being
used on one-half the coils of one tank and the absorption
machine on the rest. The steam from the compressor and
auxiliaries would furnish the 3600 lb. of exhaust required for
the generator of the absorption machine. Making all raw-
water ice with coal at $2 per ton, having an evaporative effi-
ciency of only 6 to 1, 6*2 tons would be required and the
fuel cost would be 16c. per ton of ice. Such an 80-ton plant
could be run on a 125-hp. boiler, and with a second such
boiler in reserve, the first cost, interest, depreciation, etc.,
would be low, so that including labor it should hardly be
more than 30c. per ton.
If a neighbor could be found requiring a certain amount
of power and heat, a straight SO-ton absorption machine could
be installed. By using the expansive force of the 4S00 lb.
of steam per hour required by the generator, in an economical
uniflow engine, current could be sold, not bought, which
would further reduce the operating cost.
One drawback about the electrically driven plant is the
possibility that public-service commissions at any time may
decide that the rates quoted ice plants are too low and order
them raised. Rates higher than lc. per kw.-hr. seem prohibi-
tive, although they are paid in some places. Sometimes the ice-
plant manager looks only at the comparatively low operating
cost when running full capacity and forgets that service
charges add to the cost at other times. The importances of
such charges should never be underestimated.
A properly designed combination plant owned by a central
station in a Southern city of about 50,000 inhabitants was
described.
REFRIGERATION VS. HEATING
Otto Luhr was asked to explain in an elementary way the
principles of operation of a refrigerating system. He did
this by comparing it to an ordinary steam-heating system,
as in reality it is nothing more than a heating system re-
versed, with the only difference that in a steam-heating
system heat is carried into the rooms that are to be heated,
whereas in a refrigerating system heat is carried out of the
rooms that are to be cooled. In both cases the latent heat
capacity of the heat-carrying mediums is of vital importance.
In ordinary steam-heating systems there is a boiler and
heating coils. The boiler is partly filled with water, and the
heat that is created by the combustion of fuel is absorbed
by the water, which is changed into steam by the constant
addition of heat. This steam is conveyed to the heating
coils at comparatively low pressure and temperature, the
latter usually being about 212 deg. F. As the room tempera-
ture is generally about 70 deg. there is a difference of 142
deg., and heat will constantly flow from the radiators into
the surrounding air.
With the refrigerating system the reverse process takes
place. The system consists of a heat-carrying medium con-
fined in piping similar to that of the heating system. If
the medium could be purchased cheaply no further apparatus
would be necessary, but as it is expensive the heat absorbed
by it must be abstracted and used over and over just as is
the water in a heating system. To do this a heat elevator
in the form of an ice machine and a heat extractor in the
form of a condenser become necessary. The temperature of
the medium is raised either directly by steam or by the appli-
cation of power in the form of compression. It is necessary
to raise the temperature of the medium in either of these
two ways so that water or air of ordinary temperature will
remove some of the heat contained. Water is generally used,
as it is cheaper. It has the same effect on the heat-carrying
medium as the room temperature has on the heating system.
"When it arrives at the condenser the medium is in a gasified
state, and by the action of the cooling water, wrhich con-
stantly takes heat away from the gas, it is liquefied. It is
then ready to start on the same cycle, which is constantly
repeated.
Mr. Luhr explained how the liquid ammonia in the coils
was vaporized by absorbing heat from the room to be cooled,
and enumerated some of the qualifications which go to make
up a good refrigerating medium.
As to the different systems, each was well adapted for
specific cases. For instance, it is not good policy to use a
CO. machine when the cooling water is scarce or high in
temperature. On the other hand an ammonia-compression
machine would not be desirable when there was plenty of
exhaust steam and an abundance of low-temperature cooling
■water, especially when low temperatures were to be carried
in the cooling system.
The principles of operation of refrigeration systems can
best be understood by keeping a steam engine or a heating
system in mind and considering the refrigerating end a
reverse process. In a steam engine the efficiency is the
greatest the farther apart the inlet and outlet temperatures
of the steam. In the compressor it is just the reverse: that
is, the closer the two temperatures can be brought together
the higher will be the efficiency. For this reason it is
necessary to work with a suction pressure as high as possible
and with a condenser or discharge pressure as low as possible,
as long as the proper refrigerating results can be obtained.
This means that the pipe surface in the refrigerating room
must be large, so that the difference in temperature of the
medium in the pipe and the air surrounding the pipe can be
small.
CO: MACHINES
Fred Wittenmeier, vice-president and chief engineer of
Kroeschell Brothers Ice Machine Co., explained the action
of the C02 machine, which is now made in capacities up to
150 tons. Its greatest application is in hotel basements, on
board ship and in other places where space is limited and
where the escaping fumes from a possible rupture of the
pipe lines might cause serious inconvenience.
In the last ten years air cooling by means of the C02 system
has also made rapid progress. The usual practice is to place
direct-expansion coils in the air washer. The properties of
COo were briefly given, and the results of tests made on an
air-cooling system in a church and on an ordinary refrigerat-
ing system on board ship were shown on the screen. The
principal object was to show that with condenser water in the
eighties good results could be obtained from the C02 system,
notwithstanding the general belief that it is not adapted for
use with high-temperature cooling water. In the test on
the air-cooling system, the water "went into the condenser at
84 deg. and came out at 106 deg. From the ship log the
inlet temperature of the water was 82 deg. and the outlet
temperature SS deg. As far as economy was concerned, under
normal conditions the C02 system gave results comparable
to those obtained from ammonia or S02 systems.
FROM THE VIEWPOINT OF THE CENTRAL STATION
E. W. Loyd, of the Commonwealth Edison Co., discussed
the topic of the evening from the viewpoint of the central
station. In efforts to obtain a load which would improve
their load factor, particularly in the summer months, an
investigation was made of the ice-making field. Many data
were collected and the amount of power required for refriger-
ating installations determined. This "was turned into kilowatt-
hours and a price fixed at which the company could sell
current. Rapid progress has been made and one third of a
million tons of ice is now produced in the City of Chicago by
central-station power. This is 10 per cent, of the total made
in Chicago, and has been made possible by the recent develop-
ments in raw-water ice making. The trend seems to be
toward raw-water ice where fairly pure water can be obtained.
It was originally estimated that the load factor on an ice
plant was about 65 per cent., but according to data collected
by the company the annual load factor does not exceed 45
per cent. Exceptions were found, but in any case it was
not above 65 per cent, on an annual basis. As to the kilowatt-
hours required per ton, there was a wide variation, largely
due to the varying efficiencies of the plant and the equipment
installed. The company found that the number of cans em-
ployed per ton of ice has a bearing on the subject. At the
present time they were supplying 7000 hp. for ice making,
and the total amount of power required for this purpose
in the city was estimated at 70,000 hp. The rate charged
was lc. per kw.-hr. An analysis shows that the distributing
cost is low, as the current is delivered in large quantities to
one service. The increment of cost to take on this business
was a minimum. It increased the summer load and reduced
the overhead charges, and it could be shown that the rates
were comparable to those for other classes of service.
MULTIPLE-EFFECT COMPRESSION
By means of some simple experiments and lantern slides
Gardner T. Voorhees explained the action of his device de-
signed to obtain multiple-effect compression. Low-compression
vapor first enters the cylinder, and near the end of the stroke
vapor under a higher pressure is admitted. The cylinder thus
contains a denser charge and at the same speed does more
work, or the same amount of work with less power. The
device by which these results were obtained was illustrated
and the results of a number of tests given to show the
economies obtained. In one particular case, with 90 deg. F.
cooling water, 70 per cent, more ice was made for 25 per
cent, less power, after the compressor was fitted for multiple-
effect compression. Slides of the Quincy Market Cold-Storage
April G, 1915
P 0 W E K
491
& Warehouse Co.'s (Boston) machine, the largest In the
country, were shown. This machine, designed by F. L. Fair-
banks, is fitted with a multiple-effect compression device
and has given excellent results. For a complete description
of this machine see "Power," Dec. 8, 15, 22, 29, 1914, and Jan.
6, 1915.
By A. B. Waller
The introduction of tungsten lamps has brought about
a complete redesign of the apparatus used for lamp dimming
in theatrical work. The control rheostats, or dimmers,
which were built to regulate the illumination of carbon
lamps were found unsatisfactory when the carbons were
replaced by the metallic-filament tungsten lamps.
The resistance characteristics of the two types of lamps
in actual operating conditions indicate the reason for the
difficulty. Tungsten has a positive temperature coefficient
of resistance, while carbon has a negative temperature co-
efficient. For instance, if we have a carbon and a tungsten
filament of the same cold resistance, when both are at full
incandescence, the tungsten will have 35 times the resist-
ance of the carbon filament.
The curves shown were plotted from tests made on a
40-watt tungsten lamp and on a 100-watt carbon lamp, both
giving practically the same candlepower at lin volts. Curve
A, which is for the carbon lamp, has little slope between
the 10- and the 100-watt abscissas, an interval which rep-
resents the working range of the lamp. Since the lamps
must be totally extinguished without opening the circuit,
wc
-1
&s
1 ^
-
Carbon Filament Lamp
'urve for 40 Waft I/O Vol
200
9 (
t
Tungsten Filament Lam/.
>
100
A
ui
0
0 10 20 30 40 50 fcO 70 60 90 100
Lamp Power in Watts
Lamp Resistance vs. Lamp Power
the dimmer is built with enough resistance to reduce the
input below 10 watts, in this case to 6 watts, which is attained
. at 28 volts.
The calculation of the resistance per step of a dimmer
for a carbon lamp is similar to that of a generator field
rheostat, or of any other controller operating in series with
a substantially constant resistance across a constant-supply
voltage. The current of the lamp at the rated 110 volts is
0.9 amp., the minimum to which this will be reduced by the
rheostat is 0.1S amp., and the working resistance of the
lamp is approximately 122 ohms. At the minimum current
the resistance is actually 138 ohms, but it is satisfactory in
designing to take the resistance as constant at 122 ohms.
The negative coefficient of the carbon filament produces
a slight change of resistance which assists the action of
the dimmer. When a resistance step is cut into circuit, the
current flowing is reduced, the filament cools and increases
in resistance, which causes a further slight decrease in the
current. Any part of the rheostat cut out of circuit in-
creases the current, thus raising the filament temperature
and allowing a slightly greater current to pass. This action
is most pronounced at low voltages, the lamp resistance
remaining practically constant over the greater part of the
working voltage.
In striking contrast is the tungsten lamp, which opposes
every attempt at control, and must be regulated by much
finer divisions of resistance to get gradual dimming. The
shape of curve B indicates that the tungsten filament
changes in resistance throughout the entire working range
•From a paper presented at the midwinter convention of
the American Institute of Electrical Engineers, New York,
Feb. 17 to 19.
of the lamp; furthermore, that the rate of change is not
constant. The correct resistance for each step is readily
obtained by calculating the resistance required in series
with the lamp at various voltages. At 110 volts the tungsten
lamp takes 0.35 amp., and the minimum is 0.08 amp. at 10
volts. The corresponding resistance change is from 312 to
125 ohms.
A comparison of curves A and B shows the marked con-
trast between the tungsten and the carbon lamps. The re-
sistance of the tungsten lamp at full incandescence is about
16.5 times its cold resistance, while that of the carbon fila-
ment at full incandescence is approximately half the cold re-
sistance. The tungsten filament becomes visible red at 1"
volts, the carbon at 28 volts.
Two Flywlheefls Exqpllodle a^t
HMiinaois Steel C©."§ Pllauiaft
During the morning of Mar. 17, shortly after 3 o'clock,
two immense flywheels exploded in the No. 1 rail mill of the
Illinois Steel Co. at South Chicago. Out of 150 employees
imperiled, one man was killed, two have since died, two
more were scalded about the face and arms by escaping steam
and a fifth received two scalp wounds. The property damage
is estimated at $75,000, and about 300 employees will be
thrown out of work until the mill can be rebuilt, which will
probably take about six weeks. That more were not killed or
injured is a marvel that might be explained by the immediate
rush for safety by employees accustomed to danger and con-
sequently alert to the slightest warning.
After a shutdown for the winter, the mill had been re-
opened about 10 days previous to the accident. It consists
of a long building about 80 ft. wide, housing three com-
pound engines and their respective rolls. The dummy en-
gine, which caused the accident, was located at the north
end of the mill, the finishing engine 112 ft. south, and 104 ft.
farther on the blooming engine. They are all of the tan-
dem-compound type and practically in line. The dummy en-
gine was installed in 1890 and compounded in 1905. It had
cylinders 34&60x66 in. and a speed of 80 r.p.m. The fly-
wheel, which was of the solid-rim split type, weighed 65
tons, and its dimensions were about as follows: Diameter,
25 ft.; face, 20 in.; thickness of rim, 20 in. The finishing en-
gine had cylinders 40&70x66 in. and a 70-ton flywheel. The
blooming engine was about the same size.
From the blooming rolls the bars of metal are passed
along to the roughing rolls driven by the finishing engine,
then to the dummy rolls and back to the finishing rolls. At
the time of the accident a bar had just been rolled by the
dummy engine and passed back to the finishing set of rolls
at the center of the mill. While waiting for another bar to
be delivered from the roughing rolls, the dummy engine
speeded up and the flywheel exploded. The flying pieces from
this wheel caused the flywheel on the finishing engine to giv<
way, and between the two 125 ft. of the roof was brought
to the floor. A traveling crane having a 77-ft. span, and at
the time being located above the dummy engine, was de-
molished, but in stopping some of the heavy parts helped
to save a considerable portion of the roof. Of the few pieces
landing outside the building, one passed down into a shed
and damaged a number of motor armatures which had been
stored there.
The low-pressure cylinder of the dummy engine was de-
molished, the connecting-rod broken and the bedplate cracked
at the bearing. The finishing engine was stripped of its
valve gear. A piece of one of the flywheels smashed a valve
bonnet on the high-pressure cylinder of the blooming engine
and ruptured the steam connection between the two cylin-
ders. A wiper on this engine was instantly killed and a
machinist and a helper burned about the face and arms by
the escaping steam. More damage at this point was pre-
vented by a roll rack containing nine 30-in. rolls, three high
and three wide. Seven were broken. The engineer on the
finishing engine was so badly hurt that he died a little later,
but the engineer of the dummy engine escaped with a couple
of scalp wounds.
Fortunately, the steam piping had been designed for just
such a contingency. The main supply pipe had been carried
outside the building. The pipe leading to each engine passed
through the wall, then down and directly across to the throt-
tle, so that there was no overhead piping to flood the mill
with steam in case of a rupture.
The governors were of the standard automatic-cutoff fly-
ball type, driven from a sheave on the main shaft by three
independent ropes. In addition, each engine was equipped
with a quick stop which might be operated from a number
of push buttons placed in convenient locations. There was
no automatic stop to set a definite limit on the speed. Such
492
row E R
Vol. 41, No. 14
a device in working; order, whether electrical or mechanical.
would have prevented the accident.
Several years ago an automatic electric stop had been
tried out on the blooming- and finishing engines, hut the
graphite, scale and dirt common to steel mills interfered with
its operation. The contacts would build up, close the cir-
cuit prematurely and frequently stop the engine with a bar
in the rolls. It was not stated how often the contacts were
inspected, but the result was a discontinuance of the auto-
matic feature. Dependence was placed on the engineer at
the throttle and the hand-operated stops previously men-
tioned.
In his report the engineer of the dummy engine claimed
to have pushed one of the buttons, but apparently too late to
save his engine. This action, however, would shut off the
steam and eliminate one of the sources of danger.
Admission to the scene of the explosion was not granted,
so that it is impossible to form accurate conclusions as ta
the cause of the accident. It was claimed that all the equip-
ment was in good order, as far as known. No flaws were
detected in the metal of the flywheels, and the governors
had operated satisfactorily during the 10 days since the
shutdown.
The following theories are advanced as possibilities Not
infrequently, water finds its way into the pits of the fly-
wheels. Some of it may have been splashed on the ropes
driving the governor, causing them to slip and allowing the
engine to run away. Breakage of the ropes would produce
the same result. Either might happen in the grease- and
scale-laden atmosphere of a steel mill, depending upon tlve
frequency and thoroughness of inspection.
WsiHe5r=P©w©s= Mottos* Drive ins a
An extremely flexible arrangement has been worked out
by the Northwestern Consolidated Milling Company for one
of its large flour mills at Minneapolis. This plant is driven
by both a waterwheel set and a large synchronous motor con-
nected to the same shaft. When water is plentiful the tur-
bine wheel is operated at full load, pulling the mill and con-
verting its surplus power into electrical energy in the motor
unit, which is for the time operated as an alternating-current
generator. The electrical energy thus generated, amounting
to several hundred horsepower, is used to supply other mills
and elevators operated by the same company.
When, however, the output of the waterwheel is in-
sufficient to pull the mill itself, the synchronous motor is
called into service, taking its supply from the mill steam-
turbine plant. In case of low water this motor is used to drive
the whole mill. On still other occasions, when the mill is shut
down and it is desired to utilize the water power, the water-
wheel can again be used to drive the motor unit as a genera-
tor, feeding its entire output into the mill system. In pre-
paring the switchboard connections for this flexible arrange-
ment it was, of course, necessary to provide for reversing the
wattmeter connections by means of a reversing switch \ hi
the motor is operating as a generator. — "Electrical World."
Most of the trouble with the "North Dakota's" engines
has been with her blading, and most of the repairs have been
in renewing defective blading, nozzles, and the like. When
she was sent to the Norfolk yard last month, to again undergo
s. an examination disclosed that most of the blading
in the first and second rows of the first stage were broken,
having been bent over and twisted out of shape by the
steam pressure, almost like so much cardboard. It is now
being repaired, and when finished, the ship will again be
placed in commission, although it is the opinion of the
department steam engineers that eventually the turbines will
have to be removed and replaced with either electrically driven
machinery or turbine reduction gear.
W. C. GREEN
W. C Green, well known to the Western mining trade for
the past 2."j years, and for the past six years representative
of the .Mechanical Goods Department of the Diamond Rubber
Co., died Feb. 13, from an attack of pneumonia. Mr. Green's
work for the Diamond Rubber Co. will be carried on by
<'. A. Tracy.
FREDERICK W. TAYLOR
Frederick Winslow Taylor, distinguished for his labors
in the field of increasing industrial efficiency, and the orig-
inator of the Taylor system of scientific management, died
in Philadelphia. Mar. 21, of a sudden attack of pneumonia.
He was born in Germantown, Penn., in 1S56, and received
his early schooling in this country and in France and Ger-
many. Impaired eyesight prevented his entering college
at the age of IS, and he began an apprenticeship in a Phila-
delphia pump works. Completing this course, he entered
the Midvale Steel Works and shortly afterward was in charge
of the toolroom. In six years he was chief engineer of the
company. By night study he was enabled to obtain an en-
gineering degree from Stevens Institute in 1&S3.
While at Midvale he studied systematically the production
and its expense, and increased the output 200 to 300 per cent.
by increasing the men's pay 25 to 100 per cent. Later, this
became his specialty: "The development and application of
the science of shop organization and management." From
1S90 on he practiced as a consulting engineer along these
lines. In 1898, while retained by the Bethlehem Steel Co. to
increase its machine-shop output, he with Maunsel White
discovered the Taylor-White process of heat treatment, in-
creasing the cutting efficiency of tool steel.
He presented two notable papers to the American Society
of Mechanical Engineers: "A Piece-Rate System and Shop
Management" and "The Art of Cutting Metals." In 1906 he
was president of the society.
T^rfolimes iira
Once more the U. S. Dreadnaught "North Dakota" is in
drydock for repairs to her turbines. These engines have been
in trouble a good part of the time since the big ship was
launched in 1910, and the navy's experience in this case has
been such an unhappy one that it is unlikely that engines
of this kind will be installed in new battleships.
Something like $200,000 has been spent on the "North
Dakota" for repairs in five years, nearly half of which has
been for repairs to the turbines. Naval experts deny that
the frequent troubles with the engines are due to defects
in material or construction, but charge the cost wholly to
inaptitude.
Curtis turbines were installed in the "North Dakota" as
a test for this type of engine and the "Delaware," a sister
ship finished and launched in the same year, was equipped
with reciprocating engines. On their trial trips the "North
Dakota" made her required speed of 21 knots an hour, while
the "Delaware" did half a mile better. Navy Department
officials say that in coal consumption and efficiency the
turbines have not made good, in comparison with other types
of engines. At cruising speed, the coal consumption of the
"North Dakota" has been from 30 to 40 per cent, greater than
that of the "Delaware," even when the turbines were working
well and in good repair.
W. D. Ranney has been appointed chief smoke inspector
for the City of Columbus, Ohio.
William Siebenmorgan. formerly chief engineer of the
C & C Electric & Manufacturing Co., of Garwood, N. J., is
no longer connected with that company, his resignation
having taken effect early in February.
EMGEHEER1HG AFFAIRS
The American Society of Mechanical Engineers is to hold
a meeting in San Francisco on Sept. 16 and IT, in connection
with the Panama-Pacific Exposition. For the benefit of those
who will attend, a special train schedule will be arranged
over the Southern Pacific. It is planned to pick up at New
Orleans those members who will start from the Middle West
or South and other points farther west than New Tork.
According to the schedule as at present arranged, the party
will leave New Tork either Thursday evening, Sept. 9, or
Friday evening, Sept. 10, and will stop at Niagara Falls,
the Grand Canon and possibly Colorado Springs. The Hotel
Clift has been selected as the headquarters of the society
during the meeting. An International Engineering Congress
will be held in San Francisco from Sept. 20 to 25.
POWER
^<^>'
\..l. M NEW V(M;K. APEIL 13, L915
mi I I
No. 15
Two Wi\y§ of QoimiM tto W©rfe
Botlh Sir© g? e ft ft ii e& g| ftih© sam© salaf ^ saowp Ibsmfc ra<o^ for Soirag?
iniiiiiiiii I i ii in mm iiiii 11 imiiiii n minimi miiiiii niiiimi iiiimmir niiiiinmm
(SuQucxtt'il by tht: IctU-r from Milton W. Elmoutorf, WilkiluibwQ, Penn.t l> loe 515)
491
1' UWEB
Vol. 41, No. 15
'Citric Power Plant ait
CMttfeimaeinip V4.
\'<\ Thomas Fb \ m i:i:
SYNOPSIS — ZViis hydro-electric development op-
erates under a head of ',•>'" ft. and was built to
utilize the storage of a reservoir already provided,
the water of which performed no work in flowing
to the lower reservoir through East Creek. The
plant consists of two lS50-hp. turbines, which drive
two WOO-kw. generators. Provision has been made
for a third unit.
The hydro-electric plant of the Fittsford Power Co.,
which is located in the town of Chittenden, about seven
miles north of Rutland, Vt., presents an interesting fea-
ture in the fact that it operates under a higher head than
any similar plant in the East.
The purpose of this development was to utilize the
storage of a reservoir already in existence, the waters
from which, in flowing along what is known as East
Creek to a lower reservoir, performed no useful work.
As the lower body of water served a hydro-electric plant
of 1200-kw. capacity, erected in 1905 and in active opera-
the maximum head with a minimum length of penstock.
A study of the contours of the East Creek valley
showed that by keeping the pipe line on the east side a
suitable gradient of 0.3 per cent, could be obtained, which
would permit a wood-stave penstock being built from the
outlet of the reservoir to a point about 2700 ft. east of
the proposed power house. At this latter location the
drop is abrupt, thus requiring a steel penstock from there
to the power house.
From the outlet of the dam of the Chittenden reser-
voir, a wood-stave penstock, 5-ft. inside diameter, extends
13,400 ft., except a section A, where the contours com-
pelled the introduction of a &-in. steel pipe on an 80-ft.
radius curve. At B there is a curve of 80-ft. radius, 75
ft. long, formed of three lengths of TViu. steel pipe, the
first of which is a taper section, changing from 60 to 54
in. From B to C the diameter of the steel pipe is 54 in.,
and from the latter point to the venturi meter, just out-
side the power house, it is 52 in. The thickness varies
between A and -A in.
Fig, 1. Link
THE
of Penstock fbom Old Poweb House to
New Uaii and Power Station
tion. no water could be diverted from this basin, and the
logical location of the new station was one as near to
the elevation of the lower reservoir as nature would per-
mit, to secure the maximum head, and so placed that all
water discharged through the new plant would be avail-
able for subsequent use at the existing station already in
operation.
The upper reservoir, although several times larger than
the lower, is of comparatively small capacity, the quan-
tity of water impounded being about one billion cubic
feet. The area of the reservoir is 2414 acres, and that
of its watershed about twenty-seven square miles. Not-
withstanding the static head of 48? ft., the small amount
of water available makes the horsepower development
rather limited. The capacity of the two units at pres-
ent installed is about 3300 hp., but provision has been
made for the future addition of another similar unit.
After surveys and examinations of the territory, the
location of the Pittsford Power Co. plant was decided
upon as shown in Fig. 1, where it is possible to utilize
The elevation of the water in the Chittenden or upper
reservoir, when the dashboards are on the dam, is 1021
ft., and the center of the outlet pipe in the dam is 975
ft., so that, dependent upon the stage of the water in
the reservoir, the initial head on the penstock may vary
between 4(i and 5 ft., which is about as low as it is de-
sirable to operate.
Connection between the outlet valve of the reservoir
and the penstock is made through a steel nipple, which
has a manhole and a 24-in. nozzle. Upon this nozzle was
placed a 24-in. steel pipe, 55 ft. high, to act as a vent to
prevent collapse when drawing off the water. This pipe
was protected by a double frost casing of wood staves and
is heated electrically by an old car heater.
For a distance of about 1400 ft. from the outlet of
the dam the penstock was made of spruce cut from the
company's tracts near the site of the work. The spruce
staves were 3% in. thick, made from 3x8-in. and 3x6-in.
stock ami milled so that it took 21 staves from the wide
stock and 7 from the narrow to make a section of pipe.
April 13, L915
P 0 \V E E
495
The w l-stave penstock, excepl the firsl I 100 ft., is
made of live Douglas fir, <%x6-in. stuck, kiln dried,
the finished staves being 2% in. thick Mini 36 p
being required to make a section of 60 in. diameter.
All bands were %-in. diameter openhearth steel, a
complete hand consisting of two pieces, one having stand-
ard beads at each end and the ether having 7-in. rolled
threads at each end.
The spacing "l' the bands varied between (i1-. in at
the dam, where the maximum head would lie 16 ft., to
;; in. at the end of (he wood-stave section, where the
maximum head would he 85 It. Manholes of pressed steel
are provided at intervals, as indicated.
loiMi k\v. generator, together with the necessary auxiliary
apparatus, and to keep this plant in operation until the
permanent plant could he built and a similar unit in-
stalled, whereupon the apparatus in the temporary station
would he removed to the permanent power house.
Early in February work mi the temporary power house
was abandoned, as it had been decided to build the en-
tire project, and work was begun on the excavation acc-
essary to provide a uniform gradient of 0.3 per cent, for
the pipe line.
Tile drains of 12-in. diameter were put in at the places
where lills were to bo made. The tile was laid in a bed
of clean sand or gravel, and the joints cemented. Small
Fig. 2. Concrete Trestle Supporting the Penstock
At a point near where the wooden and the steel pipes
join, an equalizing tower 14 ft. in diameter and 90 ft.
high is locale, i. The elevation of the bottom of this
tower is 950, or 10 ft. above the center line of the end of
the wood pipe, and the top of the tower is 19 ft. higher
than the flashboards at the dam. This tank consists of
one 10-ft. ring at the bottom and sixteen 5-ft. rings
above. Each ring is made up of three segments, bent
and dipped before shipping.
About Jan. 1, 1914, it was decided to undertake tin
construction of part of this development by the company
forces, ;,s it had a contract which stipulated that from
July 1, 1914, it was to deliver a maximum of 600 kw.
To live up to this agreement, provision was made to
build the main penstock Prom the dam to a point about
6500 ft. distant, where at 1> a right-angle turn was made,
and by running a distance of 1080 ft. a static head of
about 200 ft. would be available. It was intended to set
up at this point one of the two 1875-hp. turbines and a
rubble walls were built at the intakes and outlets of
these culverts.
The wood-pipe line crosses East Creek twice, requiring
two trestles, and also crosses a small brook. The tres-
tles have rubble abutments, and the intermediate piers are
of a uniform type, being 2x8 ft. at the top, with the front
and back vertical and the sides battered t/o in. per foot
from the top. They are of 1:2: 4 gravel concrete, rein-
forced with vertical and horizontal bars. Fig. 2 is a
photograph of tin- largesi trestle.
The Chittenden dam is 1000 ft. higher than Butland
ami 10 miles distant: the power bouse is 500 ft. higher
and 7 miles distant. With the exception of about two
miles near the city, the roads are poor. The freighter-
hauled at the rate of 8:; per ton, and in all about 2000 ton-
had to be moved. The 30-ft. lengths of steel pipe varied
between 3^ i and 5 tons.
About 40 per cent, of the wood stave line was composed
of curves. With the exception of the stretch between A
196
row e i;
Vol. 11, No. 15
Fig. 3. Chittenden P
House
and /., all curves were either 360 or 300 ft. radius. In
the locality mentioned there were some curves of these
radii, but also a few sharper ones, notably one at about 175
ft. radius. The average construction progress on curves
was about 200 ft. per day of 10 hours, and on tangents
about 300 ft. The best day's work was 420 ft., made on
a tangent where the staves averaged about 25 ft. in
length.
At points where the stave pipe joined the steel pipe,
the latter had the rivets countersunk for a distance of 4
ft. from the end, and presented a smooth outside surface
for the staves to be fitted over.
It became evident in the latter part of May that the
permanenl power house could not Be in operation by
.Inly 1. and so it was decided to build the temporary in-
stallation. Therefore, work was resumed with a view to
getting in the foundations for the turbine and generator.
At the point IK Fig. 1. a steel tee had been inserted
in the main line, and from this a 3-ft. penstock line
1080 ft. long, of which the upper oRO ft. was of spruce
ami the lower 500 ft. of ^4-in. steel plate, single lap,
with %-in. rivets, was built. The spruce staves were
milled by the company, and one-piece hands were used.
The steel pipe was sublet to a local firm, which made it
right at the site of the work.
The ends of the steel tee were punched for %-in. bolts
mi 3-in. centers and the staves of the penstock were bolted
to I lie steel tee. At the back of the tee a connection
was made to a 3-ft. diameter steel pipe, 80 ft. high.
erected to fulfill the function of a surge tank and vent.
About three feet from the downward end of this steel
tee a 5-ft. diameter V^-in. steel boiler head was set up
as a bulkhead to divert the water through the temporary
power-house penstock and to permit turning on the water
before the rest of the line was finished. Oakum was
packed in wherever possible between the bulkhead and
inside of the pipe.
The temporary plant was in operation until Oct. 1,
at which time the machinery was dismantled and placed
in the permanent plant. The penstock was taken apart
and utilized at Molly Brook, where a small collecting
basin was built at an elevation of 80 ft. above the pen-
stock at that point and the water conveyed through the
3-ft. penstock into the mam pipe line.
The steel pipe was placed alongside the trench by the
Fig. 4. Interior of the Chittenden Powee Plant
April 13, 1915
P O W E R
497
company and the pipe contractor's gang rolled the lengths
in the trench and used two small derricks to aid in
bolting up.
The reaming, riveting and calking followed in the
order named: an expansion join! was placed 1448 ft.
from the dam to allow for movement of the pipe pre-
\ ious to filling it with water and covering it.
The surge tank is on a rocky knoll at the point B.
The concrete foundation is, on an average, '■> ft. thick,
and six 2%-in. stay-holts, fitted into boles dialled in the
rock and also embedded in the foundation, provide
against movement. The connection between the pen-
stock and the tank consists of a 18-in. steel pipe. Be-
tween this pipe and the end of the wood pipe, a distance
At the bot-
valve, is a
12-in. blowoff valve designed to pass such water as might
leak past the butterfly, so that no water could leak down
the pipe when not so desired. There are manholes in
the steel pipe near the butterfly valve and at two inter-
mediate points and the pipe may also he entered through
the turbines.
The surge tank has a manhole near the bottom, and a
ladder outside affords access to the top. After testing,
a frost easing 18 ft. in diameter, or 4 ft. larger than the
diameter of the tank, was built. Old 2-in. planks of
various widths were used, butted off square without the
edges being beveled radially. The first set was placed
so that adjacent pieces broke joints, nailed plumb in
place, and then %-in. bands on ".'-ft. centers were clinched
tight. The remaining set- were easily added. At the
top i- a silo roof, in which a door i- arranged to admit
air if thi' drawing off of the water should tend to form a
vacuum. The frost casing was covered with a coaling of
cement-lime plaster applied to a wire lath as a pro-
tection againsl lire and decay; provision was made for
heating during the winter months.
Power House
The permanent power house i- a single-story structure
38x71 ft. inside and 22 ft. high (Fig. 3). 'The foun-
dation walls aiv of 1 : •.' : I gravel concrete of an average
depth, excepting the south wall, of about (i ft.; they
are 18 in. thick and rest on a 12-in. footing course '■>
ft. wide. The south wall, which forms one side of the
tail race within the building, has a depth of from 12 to
19 It. and i- 30 in. thick.
The walls id' the building consist of a 12-in. double*-
ed brick wall, pilasters 28 in. square being introduced
30 as to divide the north and south walls
into four bays and the cast and west into
three hays.
The roof is framed of three transverse
girders, between which arc standard
I-beams, and is covered with a 4-in. con-
crete slab reinforced with triangle-mesh
reinforcing. The roof is waterproofed
with six layers of tarred felt and stone
screenings.
The steel penstock enters the building
normal to and through an opening in its
front wall, and about eight feet from the
south wall. Three nozzles lead, from the
penstock to feed the turbines; they are
24 in. inside diameter and flanged to
take a 24-in. valve, fitted both for hy-
draulic and hand operation. When the
pipe had been Idled and tested the pen-
stock was heavily anchored with concrete.
The tail race lies at the south side of
the buildhig and : 1 I ft. wide, and 18
ft. deep. Over the west or hack end of
this building was built a small room, in
which is installed a low-pressure boiler
for heating the building.
The turbines are placed over the tail-
race, each being carried by a pair of
12-in. H-beams, secured by anchor bolts
and concreted in. Space has been pro-
vided for three units, although at pres-
ent only tw7o have been installed. The
the Francis type with wicket gates, are
at 720 r.p.m. under a 430-ft. head at
full gate opening. All the gate-operating mechanism
is on the outside of the flume, and is controlled by a
governor of the direct-connected type, arranged for elec-
tric control. The runner consists of a bronze runner
hand with a cast-iron hub, the latter being securely
keyed to the turbine shaft. The spiral Hume is made of
a single iron casting and has the form of a true evolu-
tionary spiral. The gate- and the guide ring are made
of cast steel, and the gate ring of cast iron. The tur-
bine shaft is made of hammered steel, li in. in diameter
on the driving end and 41.4 in. on the remote end. The
driving end of the shaft is fitted to the huh of the 5-ft.
9-in. east-iron flywheel, which weighs about five tons.
The remote end rests in an end-thrust bearing arranged
to operate in a hath of oil.
TT0
turbines,
of 1850
of
hp.
498
POWER
Vol. 41. No. 15
The draft tube is about 15 ft. long and has a diam- ings are flanged, and faced and drilled to take the T%-in.
eter of 48 in. at its lower end. To protect the line flanges of the adjacent steel pipe. The meter is con-
against undue rise in pressure caused by the action of neeted to an automatic register indicator recorder,
the governor under the varying conditions of load, a re- _,
lief valve capable of discharging 30 cu.i't. per second is Electrical Equipment
installed. The station is designed for a maximum continued ca-
The side of the flywheel remote from the turbine is pacity of 3000 kw. at 44,000 volts and 80 per cent, power
Figs. 6 and 7. Plan and Side Elevation of the Hydro-Electric Plant
fitted with a flange, to which a forged flange on the factor, this energy to be generated by three units and
generator shaft is fitted to couple the two together
An interior view of the power house is shown in Fig.
4. Figs. 5, 6 and 7 are plan and elevation of the power
plant. Just outside the power house there is inserted in
the pipe line a venturi meter with a 52-in. inlet and 27s
delivered through two 44.000-volt feeders. Two units
and one feeder are now in regular operation, and the
third unit and second feeder will be added when neces-
sary to take care of the future increase in load.
Each generator is rated at L250 kv.-a., 2300-vo4
42-in. outlet. Both the inlet and outlet ends of the cast- three-phase. 60 cycles: and with a 25-per cent, overload
April
If) I
POW EE
199
for two hours the rise in temperature is guaranteed not to
exceed 55 deg. C. above the room temperature of 2o deg.
C. Each generator has its own direct-connected exciter,
operating in parallel at 125 volts.
There are at present two hanks of transformers, each
consisting of three single-phase, lOO-kv.-a., 2300-44,-
000-volt, water-cooled transformers, and with a 25-per
cent, overload for two hours, the rise in temperature is
guaranteed not to exceed 55 deg. C. above a room tem-
perature of 25 deg. C. Cooling water is supplied from
the penstock at a reduced pressure.
The switchboard is of marble and consists of exciter
feeder panel with voltage regulator, generator, lighting
and a blank generator panel. All control and instrument
wiring is installed in iron conduit laid in the concrete
floor. As the oil switches are remote-controlled, 125
volts is the maximum on the switchboard.
A 2300-volt bus of copper tubing is supported verti-
cally on the north wall back of and above the trans-
formers. The generators connect to this bus b\ means
of lead-covered, varnished-cambric insulated cables laid
in fiber ducts below the main floor, and the usual nil
switch and disconnecting switches.
Each transformer bank is connected to the 2300-volt
bus through disconnecting switches ami to the 44,000-volt
outside bus on the roof by means of copper tubing through
the roof bushings and a three-pole air-brake switch, this
switch being hand-operated from the station floor.
The 44,000-volt bus, three-pole, air-brake switches
and lightning-arrester horn gaps are mounted on pipe
framework supported on the roof, the entire roof being
used for this purpose.
An iron stairway at the west end of the building pro-
vides easy access to the roof through a door and landing
at the main-floor level.
Electrolytic lightning arresters of indoor type are con-
nected to the horn gaps through roof bushings. The
present feeder connects to the -44,000-volt transmission
line through a three-pole, 44,000-volt, indoor-type, re-
mote-controlled auto-oil switch and the usual disconnect-
ing switches and choke coils.
The Pittsford Power Co. development was designed
ami constructed under supervision of W. S. Barstow &
Co., engineers and managers, of New York City.
:•;
The I'oillon urate illustrated herewith is designed to
burn fine dust. Lignite, coke and other grades of coal. The
particular feature is that the direction of burning gases is
from i lie end- of the urate toward the center of the Eur-
PoiLLON FUBNACE GRATE
ill the ordinary furnace the liberated gas flows toward
the bridge-wall and upward. With this grate the currents
are from the front of the furnace toward the rear and
from the rear toward the front, caused by the angle of the
air spaces in the grate. The result is that the liberated
gases from freshly fired fuel at the front mingle with the
hot gases from the rear end of the furnace, and their com-
bustion takes place before striking the cooling surface of
the boiler tubes.
The mingling of the two currents distributes the flames
PRINCIPAL EQUIPMENT OF CHITTEXDF.X HYDRO-ELECTRIC POWER PLANT
>. Equipment Kind Size Use Operating Conditions Maker
Turbines Francis, wicket gate- . 1850-hp. . Driving main generators 430 ft. head, 720 r.p.m . S. Morgan Smith Co.
Generators Alternating-current . 1250-kv.-a. . . Main units 720 rp.m., 2300 volts, 3-phase, 60-cycle. .. . General Electric Co.
Governors Direct-connected With main turbines Electrically controlled .-. . Lombard Governor Co.
Exciters Direct-current With main generator- ... Coupled to generator shafts. 125 volte . . General Electric Co.
Switchboard Marble. . . Electrical control of units General Electric Co.
Transformers. . . . Water-cooled 400-kv.-a Stepping-up current 2300-44,000 volts, single-phase, 60-cycle . . . . General Electric Co.
All electrical apparatus in power house, such as switches, lightning arresters, etc ... ...... General Electric Co.
Illumination is obtained from six 2.)0-watt tungsten
lamps in deep-bowl reflectors hung close to the ceiling,
the outlet boxes and connecting conduit for wiring being
cast in the concrete roof. Extra illumination and plug
receptacles for portable lamps are conveniently distrib-
uted on the walls of the building. Outdoor lighting i-
provided for the roof by means of street lighting fix-
tures, thus assisting greatly in inspection and repair at
night.
Illumination is controlled from the eight-circuit light-
ing panel, which is a part of the main switchboard. A
double-throw switch mounted on this panel enables the
lighting supply to be taken from the 2300-volt bus
through a 3-kw. transformer or from the exciter bus.
The permanent power house was placed in operation
about Oct. 1, 1914, and the unit from the temporary
plant was set up during that month.
over a large tube area and prevents the hottest flames
from striking the tube in the form of a jet, as would be
the tendency were they to go to the tubes with no inter-
ruption.
As illustrated, the grate (which is placed on the market
by Julian Champeaux, 36 Down-hire Hill, London,
X. W.) is used in connection with a blower.
Boiler Accidents — A report submitted at the convention of
the American Society of Mechanical Engineers in New York
City last December contained the following statement:
Every year there averages in the United States between
1300 and 1400 serious boiler accidents, of which 300 to 40u
are violent explosions. These accidents kill between 400 and
500 persons, injure 700 to S00 more, and destroy more than
half a million dollars' worth of property. In a single ex-
plosion, that of the R. B. Grover Shoe Co., at Brockton, Mass.,
58 persons were killed, 117 more were injured, $250,000 worth
of property was destroyed, and an aggregate of $280,000 was
claimed in the personal injury and death suits that were
brought. In a period of 46 years, since 1S67, over 10,000
people have been killed and over 15,000 injured in boiler ex-
plosions
500
r ( ) w e 1;
Vol. 41, No. 15
•micy
By Ceo. F. Willie
SYNOPSIS — The importance of the preliminary
work while laying out a power installation. Only
by studying the conditions and selecting the equip-
ment to suit can one expect to hare a truly ef-
ficient phut!.
This is the day of efficiency in all classes of manufac-
turing, and the successful manufacturer looks for it all
along the line. After a plant is huilt. the operation is
closely watched in order that efficiency in all departments
may be secured. Many schemes, from piecework to bonus
payment, are used, all to add to the one proposition — effi-
ciency.
But how few manufacturers or owners go at this matter
from the first inception of the plant! It is decided to
build a factory for a certain purpose, costing say $250.-
000. It is easy to find architects competent to build the
housing, and the plans are made, submitted and accepted.
But the power plant, the real heart of the proposition —
the boiler and engine equipment, the electrical power to
be used for lights and motors, the pumps, economizers.
heaters, condensers — all this is usually left to the archi-
tects, who are the last people who should have any sa]
as to this part of the outfit, as their experience and effi-
ciency are practically limited to the building itself. They
work out the balance of the scheme as best they may,
as an accessory to the original in which they are most in-
terested, and men are too often influenced by personal
acquaintanceship and prejudice.
The use of oil and gasoline engines, producer-gas
equipment, electrical driving and its advantages and
disadvantages — these problems are neither thoroughly
considered nor gone into expertly, but are usually left to
the good or bad judgment of the original designers of the
building itself. When it is known that in building a fac-
tory costing the amount mentioned, there might be made
a saving of 10 per cent., or $25,000, by calling in engineers
in the special lines mentioned, their cost being but a small
part of the saving named, it is curious that such technical
ability is seldom called for, and the fat tory is built with-
out the owners knowing what might have been saved for
the same capacity or what might have been added to the
capacity reached, by the advice of technical experts in the
particular line for which the factory is built.
The writer is often confronted by the advertisement of
some manufacturer of belts, for instance, who will take a
whole page in some technical journal to tell about a big
belt he has just supplied to some concern. This will be a
triple leather belt, 84 in. wide ami 160 ft. long, we will saw
and he goes on to tell how many steer hides it took to make
it,, how much it weighs, what it will drive, etc. In the
writer's opinion, anyone shows poor judgment who uses
a belt any wider than, or even as wide as, 24 in. He also
believes that manila-rope transmission for anything in
the way. of main drives from 50 hp. up is cheaper and bet-
ter than any belt drive. In the case of such a belt as men-
tioned, the saving in the original cost by using ropes
would be some $2000, and the ropes would have as long
life as the belt, with less slippage and a smoother and more
positive drive all around. In such a case it is probable
that the designers of the plant have seen so many wide
belts in other plants that they have no idea anything else
could lie used. It is a case of mental suggestion.
Take the case of a company building a $75,000 sawmill.
Tt is \\illing to and usually does build the plant from the
plans of the maker of the machinery to be used, who is
naturally a much interested party. A.s a judge of the de-
sign the purchaser calls in his old foreman, who has been
with him many years, and as he ran the old plant suc-
cessfully he i> considered an authority. He well knows
every weak place in the old plant, and he is firmly re-
solved that in case he has anything to say about the new
one. these sveak spots will be eliminated. So when the
new plans are offered him for his criticism, he rigidly
turns down anything that looks like the trouble spots he
had to contend with for so many years, and finally ap-
proves the plans submitted. He does not know what new
troubles the new plant will bring, and he is not capable of
selecting from the mass of technical details of machinery
offered the best to be used. So the concern buys, and
the mill is built. It may run to the satisfaction of the
owners, but like a doctor's mistakes, all that have been
made are buried ; and while it might have been possible
to build the same mill for less money, to build a better mill
for the same money, to build a mill at the same cost which
would produce the same amount of lumber with a few-
less hands, all this is unknown, and the expert engineer
was never called in, everything being left to the judgment
of one man who knew all about one mill and nothing of
any other.
The writer's experience of something like twenty-five
years in designing and building plants has shown him that
efficiency rarely begins at the commencement of the opera-
tion— where it more properly belongs than at a later pe-
riod— and that nine out of ten plants are built from crude
ideas of owners and employees. One manufacturer who
intends building is positive that he will use electrical
transmission throughout. He does not know exactly why.
but he has read of the great strides that have been made
in introducing this system, ami as a factory a few blocks
away has just been completed and this transmission is
used throughout, why should not he use it? It may he
that this is the least desirable system for his special re-
quirements, bat he does not call in a transmission expert
to secure his views and advice. The electrical people are
willing to meet him more than half way and confirm
his views and wishes. So he spends much money for a
power-transmission scheme that does not suit his condi-
tions and is satisfied forever afterward because his factory
runs and produces.
No one maker of machinery builds a full line of the best.
He may have one or two machines that cannot be equaled,
one or two that are about as good as others, and the rest
of his line not so good as those built by his competitors.
But the tendency is to buy the full equipment from one
maker, on a blanket proposition covering the full list of
machines required. This, in a way. largely depends upon
the salesman that secures the order. Many times the
writer has sold the complete equipment for a plant on
April i:i. L915
POW E R
501
the strength of one machine which his company originated,
and built better than anyone else. The fact that this ma-
chine cost several hundred dollars more to build than was
got for it mattered not, as this was made up on the re-
mainder of the order. Six out of ten times we sold the
power plant, which we did not build at all, and which we
bought as cheaply as we could so long as it approached the
requirements — said requirements being suggested by our-
selves, of course Had a competent engineer been called
in on these jobs, it is likely we would have secured the or-
der for the one machine we built better than our competi-
tors ami that the rest of the equipment would have been
ordered from other makers as it should have been.
Were a man to contemplate building a home to cost
$75,000 or an office building to cost $250,000, he would
first go to the besl architects he knew of to procure the
plans They would supposedly have at their command
technical engineers who were thoroughly conversant with
all building requirements and whose efficiency would be
added to that of the members of the designing stall'. The
plans would be prepared with great care and thoroughness,
and after a careful analysis by the owner, would be ac-
cepted and built from. Were the same man to contem-
plate the building of a sawmill costing as much or more,
he probably would leave the important part of the whole
proposition to "Jim." who bail run the old plant for thirty
years and who should know just what was needed in a new
one.
As to power efficiency, the proper kind and character of
the boiler plant, whether steam or gas or electricity should
be used, all swings on the opinion of the old employee,
whose influence is not to be laughed at either. Good or
bad, his advice is followed, greatly to the embarrassment
of the expert, should one he called in.
In the city in which the writer lives, is one of the largest
and, supposedly, one of the most advanced companies in
the world, which has become famous by dividing its profits
with its employees, with which strikes are unknown, and
whose power plant is one of the sights of the city. It has
been shown by technical engineers of high standing, after
an investigation lasting for weeks, that by scrapping its
beautiful engines — nickel-plated and in a room as beauti-
ful as any parlor — the company could make a saving in
fuel and upkeep amounting to many thousands of dollars
yearly. Would it do it? No, because a man who had
been for years close to the president and had sold the com-
pany its valves and small equipment advised against it —
said the plant was all right as it was and that the ex-
perts did not know what they were talking about. His
advice "went," anil no change has been made. Thin sim-
ply goes to show the small amount of credence given the
technical engineer in matters within his own province, and
on which ne has absolute information.
In the really great and advanced plants engineers may
be found who are employed at salaries running up to
^'.'■"i.OOO a year and more, and they are cheap men at the
price. But in the half-way plants, the ones costing up to
the half-million mark, where the technical engineer is
nearly always badly needed, he is seldom called in. It
is easy to be too technical, so to speak, but the combina-
tion of fifty-fifty — half experience and half technical
knowledge — will, when secured for even a small plant,
well repay the owners, not only in the original cost, but in
the following years of operation.
[More stones of stupidity ami ignorance competing
with "Some Original hints," us printed -Inn. ID, nil-',.]
"What's tin' matter?" asked the superintendent of the
second-class licensed engineer on hearing the receiver re-
lief valve blowing fiercely on the 1200-hp. compound en-
gine.
"I guess the exhaust pipe has burst between the engine
and the condenser."
"Well, the vacuum is up to 27 in., isn't it?"
But the engineer was making haste to start the larger
engine and did not wait for argument. The superinten-
dent, win, had formerly been the chief in that station,
walked over to the low-pressure side of the engine and
pushed the reach rod up forward on the governor, and
the relief valve stopped blowing. The engineer returned
hastily to sec what hail caused the engine to become quiet
so suddenly. He was cautioned not to tell anyone that
he thought the exhaust pipe on a condensing engine had
hurst with 2", in. of vacuum, but thereafter to watch the
governor on the low-pressure side to see it did not unhook
again, leaving both steam valves closed. — /.'. A. Cullra,
Cambridge, Mass.
A WEtfc KNOWN EXPRESSION
M0RC0££3Ji3T0ir0U
A young man recently out of college secured employ-
ment as helper around a power plant in an industrial es-
tablishment. One day the engineer was called to another
part of the plant and left the young man alone in the
power house.
After a time the engineer noticed a cloud of steam
coming from the blowoff pipe. He did not pay much at-
tention to it at first, thinking that the young man had
too much water in the boilers and wanted to blow down a
little, hut when the blowing had continued for some time
he started I'm- the power house to investigate.
Upon arriving, he found that a gage-glass had broken
and that the helper had the blowoff valve wide open. When
questioned concerning his reason for having the valve
open, he said that he wanted to let out the pressure so
that he could put in a new glass.
It might lie well added that the young man had not
studied engineering while at college, but is now a good
engineer and has had some six or eight years of experience
in the "school of hard knocks'' since the incident re-
lated.— Earl Pagett, Coffeyville, Kan.
502
P 0 'W E E
Vol. 41, No. 15
>l-EmiElinie ImistaMg^tiioini mt 'Pal©
By Herbert Haas
SYNOPSIS— By installing a SOO-hp. Diesel
engine to carry the day load and using one of
the steam units to help out on the peak, a sav-
ing of about $6000 has been effected. Heavy Cali-
fornia residue is used.
In 1913 the City of Palo Alto. Calif., contemplated
replacing its old and rather wasteful steam engines with
a steam turbine of excess capacity above the equipment
then in operation, which consisted of a cross-compound,
slide-valve engine coupled to a 200-kw. alternator, a simi-
lar engine driving a 100-kw. alternator, both operating
noncondensing, and a single-cylinder, simple engine, with
Corliss valve gear, belted to a 50-kw. generator. The two
larger engines furnished practically all the load, which
for a short period, between 7 and 10 p.m., ruse to 330
kw. The steam turbine was to be a 500-kv.-a. unit, oper-
= 250
0 150
°100
Shaded part\ represents
■peak load, to be supplied-
b'y /00 kilowatt, steam '
engine \
40 JdN_Ebr_Ql6SEL_EN6INE_i
Load above\ curve and under, horizontal lint\^an\ be 'furnished
'by-Diesel -engine\developing-increased-busjness~and~irnproved-
load
is load, furnished
now by Diesel engine
E- Z 4- 6 8 10 B E 4 6
K- A.M. — >K- P.M.-
8 10 R Z 4 e
->K A.M.
Fu:. 1. Load Characteristics for 24 Hr.
atmg condensing, its excess capacity being intended t>>
take care of expanding power and light business.
Fig. 1 shows the load characteristics during 24 hr..
based on a .yearly average of the load in 1912. It will be
noticed that it is a typical lighting load, only a portion
of the power being used in the daytime to operate pump
motors. With a load factor, then, of about 30 per cent.,
this would have become still more unfavorable after the
installation of a 500-kv.-a. turbine, for the load would
have been around 20 per cent, of the rated capacity of the
turbine during the greater part of the time.
Therefore, the writer advocated the installation of a
Diesel engine, which, to save in initial investment, was
to be of moderate size only, sufficient to carry the entire
load except between 6 p.m. and 10 p.m., when one of
the existing steam engines was to operate in parallel
with the Diesel engine to supply the peak load. The
average fuel consumption of the steam plant was 11,000
lb. per day for an average output of 2620 kw.-hr. per day,
or 4.2 lb. of fuel oil per kilowatt-hour. It was figured
that the Diesel engine would furnish 2400 kw.-hr. (oper-
ating at fractional loads, as shown in Fig. 1) with a fuel
consumption of 1800 lb., and that the 100-kw. engine
unit, operating at full load, would furnish the other 200
or 250 kw.-hr. with a fuel consumption of about 4 lb. per
kw.-hr., or 800 to 1000 lb. of fuel oil, in addition to a
moderate amount of oil to keep one of the boilers always
under steam as a stand-by. Thus, about 22 to 24 bbl. of
fuel oil, costing 90c. per bbl., could be saved per day.
Against this saving had to be charged interest and amort-
ization on the capital invested in the Diesel engine plant,
the slightly higher cost of cylinder lubrication and main-
tenance. It was thus figured that a saving of $6000
to $7000 per year could be made by the installation of a
Diesel-engine set. The operating force was not increased,
so the labor item remained the same. It will be seen
from the load curve that the Diesel engine would be
operating only at about 50 per cent, of its capacity during
tho day, so that considerable reserve capacity was avail-
able for a future increase in load during this period, and
any increase in the peak load could still be furnished by
the existing steam equipment.
One of the requirements of the engine was the burning
of California crude oils or residues, of the same or simi-
lar quality as that which is burned under the boilers.
The power plant is some distance from the railroad, the
fuel oil being pumped to it through a pipe line, which
would make it difficult to supply two different oils, one
for the boilers and the other for the Diesel engine.
In view of the extensive development of this type
in Germany, and after thorough investigation, the Kcirting
Diesel engine was selected, as this engine was found to
be giving excellent service in Mexico, running on the
heavy asphaltic oils and residues similar to the California
oils. The engine is of horizontal construction and has
four cylinders. The shaft is extended, and carries the
flywheel and the alternating-current generator between
the left outer main bearing and an outboard bearing.
Beyond the outboard bearing there is a further shaft ex-
tension, to which are keyed the armature and commu-
tator of a 10-kw. exciter. The shaft is forged in halves,
coupled together between the halves of the engine. To
the right-hand shaft end is bolted a crank disk, from
which is driven the air compressor. Each shaft sec-
tion has two cranks, set at 180 deg. The generator is a
two-phase, 60-cycle, 40-pole Fort Wayne machine, wound
for 2300/2400 volts, and rated at 250 kv.-a., which at 80
per cent, power factor is equivalent to an output of 200 kw.
The pistons are of trunk pattern made especially long
to reduce pressure exerted through the crank and pis-
ton pins and prevent wear of the cylinder liners. The
valves are seated in the cylinder heads, and are all easily
accessible, being mounted in individual cages, and can be
quickly exchanged. This is of importance, as the exhaust
and fuel-injection valves have to be cleaned monthly:
spare valves are put in their places and the removed
valves are then cleaned at leisure, and kept in readiness.
The governor and valve-gear shafts are operated di-
rectly from the main shaft through helical gears run-
ning in oil. The governor shaft operates the engine gov-
ernor, lubricating pumps, and fuel pumps. Of special
note is the construction of the fuel pump and the fuel
injector. The pump does not have to force the oil against
the injection air stored around the fuel-valve needle at
a pressure of 800 to 900 lb., a practice common to many
April 13, 1915
i'U \\ E 1;
503
Diesel engines. Instead, the pump works al just enough
pressure (only a few pounds) to lifl the oi] into a cham-
ber in the Euel injector durum' the suction stroke of the
piston. The governor can, therefore, act directly on the
pump plunger and vary it- stroke according I" the exad
fuel requirements of the engine, proportionate to its load.
The fuel injector has no oeedle valve, but consists of an
open Korting atomizing oozzle. A Eew deg] s before
the completion of the compression stroke, a valve in the
fuel injector connecting with the injection-air supply
pipe is opened, admitting the highly compressed air, at
800 to 900 IK. which carries the fuel-oil charge (stored
in the injector during the suction stroke) into the cyl-
inder, at the same time completely atomizing it.
Each cylinder has its individual fuel pump, two pumps
being mounted cm each valve-gear shaft. The Hartung
governor acts on all four pump plungers simultaneously,
pressure stage being vertical, the intermediate and high-
pressure stages being tandem horizontal cylinders. Be-
tween each stagi there in an intercooler and oil separator,
and the compressor cylinders arc all water- jacketed for
ling. The interposition of coolers and « > i l separators
is an important safeguard to prevent explosions. The
injection air is stored in two wrought-steel bottles, 8-in.
diameter by <i ft., of which one only is in use, the other
acting as a reserve.
The oil flows ic> the fuel pumps by gravity from a
supply tank holding one day's supply and supported on
a shell' attached to the wall of the engine room. It is
pumped to this tank from the concrete main storage
tank, which is built into the ground outside the power
house. This fuel oil, being a residue of California crudes
(topped oil), has to be heated on account of its high
viscosity. This is usually done by using the heated jacket
Fig. 2. Installation of Korting-Diesel Engine \t Palo Alto, Calif.
through wedges which increase or decrease the throw of
the plungers with an increase or decrease in the load of
the engine. This method of governing is very sensitive.
the engine adjusting itself instantly to changes in load.
Another feature worthy of note is the method of start-
ing. Instead of using high-pressure air, which takes con-
siderable power tci compress, the engine is started with air
at £20 lh. and can be started with a pressure as low as
110 lh.. if necessary. The air i- stored in a sheet-steel re-
ceiver. This method of starting i- made possible by hav-
ing the exhausl valves open during the compression
stroke, so that the cylinders work against atmospheric
pressure only; when the engine is up to speed, the se-
quence of the valve play is changed, the air is compressed,
and the find charge is admitted, the exhaust valves then
discharging the products of combustion.
The air fur starting the engine and the injection air
for atomizing the fuel and forcing it into the engine
cylinder is furnished by a three-stage compressor, the low-
water of the engine. For starting, a gas oil is used
(Standard Oil Co.'s Star fuel oil) and, after a few min-
utes' operation, the engine and circulating water are
warm enough to substitute the residue'. At Palo Alto,
however, the latter is now heated by steam and the engine
runs continuously on the residue.
The air intake for the engine and for the compressor is
mi the outside of the power house, the air main and in-
dividual air conduits leading from it being built into the
engine foundation and connecting with the air-intake
pipes of the cylinders. The exhaust gases are passed
through two double silencers and then through pipes
leading under tin' boilers, from which they are carried
off by the holler Mack. The pipe connections between
the exhaust ports and tin1 silencers are water-cooled to
prevenl ce i e radiation and heating of the space im-
mediately around the engine heads.
All internal lubrication is supplied by two Bosch lu-
bricating presses operated from the governor shafts. The
504
P 0 W E R
Vol. 41, No. 15
piston pins are also lubricated by these. The lubrica-
tion of the main bearings and of the crankpin bearings is
supplied by a geared lubricating pump, which forces a
stream of oil to each bearing, collecting rings prevent-
ing any being spilled. The oil is fed to the crankpin
bearings by lifting rings. All oil is collected in the crank
case, flows through a filter and cooler, and is returned
to the main container, located below the floor. The bear-
ings are also provided with individual glass reservoirs and
rings for use in case the lubricating-oil pump should
fail.
For testing the engine before shipment, 4 tons of
Standard Oil Co.'s Richmond fuel oil (a residue) was
Load
5.
4 90 0.60
60 0.55
225
B.Hp.
500 550
I.Hp.
Fig. 3. Performance Curves of 300-Hp., Fotje-
Ctlinder Kortixg-Diesel Engine
shipped to Germany. T!. E. Mathot, of Brussels, acted
as consulting engineer for the City of Palo Alto, and
conducted the tests at the works of the builder. The
principal test data are here given, and the engine per-
formance is shown in Fig. 3.
The California fuel oil (Richmond Fuel Oil) had the
following properties:
Lower heat value 17,741 B.t.u.
Gravity at 59 deg. F. (15 deg. C.) 0.94S
Flash point in open air 185 deg. F.
Boiling analysis —
Oil begins to boil at 223 deg. C.
Amounts distilled in per cent, of the volume
at 250 deg. C. 1.5
at 300 deg. C. 12.5
Contents in ash, per cent 0.01
Contents in coke, per cent 5.29
Contents in asphaltum, per cent 1.65
Contents in water, per cent 0.1
Contents in insoluble matter, per cent 0.002
Viscosity (Engler) at 20 deg. C 129.3
at 50 deg. C 12.9
at 80 deg. C 3.48
Chemical analysis —
Carbon, per cent S6.59
Hydrogen, per cent 11.47
Oxygen and nitrogen, per cent 1.33
Sulphur, per cent 0.61
Note — The oil is very high in constituents, boiling above
300 deg. C, also high in coke.
The guarantees for fuel consumption made by the build-
ers, with a 10 per cent, tolerance in their favor, with oil
having a mean lower heat value of 18,000 B.t.u. per lb.
per b.hp.-hr., were : At full load, 0.420 lb. ; at % load,
0.0440 lb.; and at i/2 load, 0.510 lb.
The fuel consumptions determined by test, using the
oil with a heat value of 17,741 B.t.u. per lb., were as
follows : At full load, 0.388 lb. ; at % load, 0.385 lb. ; and
at i/2 load, 0.439 lb.
These figures are lower than those guaranteed, espe-
cially if the difference in heat value of the oil used is
taken into consideration. Indicator diagrams were
taken simultaneously on all four cylinders, also on the
low and intermediate pressure stages of the air com-
pressor. The small clearance space in the high-pressure
cylinder of the compressor did not permit of attaching
an indicator to it. The fuel consumption given includes
all work done by the engine and the compressor and
represents the net work delivered at the shaft.
Since the engine has been installed and its output has
been checked by the output of the generator, the average
fuel consumption falls within the guarantee. Some diffi-
culty was at first experienced in finding a cylinder oil
which would stand the high temperature in the engine
cylinders and compressor. This was met by lowering the
cooling-water temperature issuing from the jackets, and
principally by experimenting with different oils until
one was found that had the desired properties and gave
satisfaction. The most gratifying result of the installa-
tion is the fact that the predicted saving has been
fully realized, the City of Palo Alto saving about $20
daily above its previous practice; and the work of Messrs.
J. F. Byxbee and A. V. Youens, representing the City of
Palo Alto, is an example of what a progressive municipal-
ity under proper guidance can do in furnishing cheap
lighting and power service.
Qtifl£cI&=A<cttl3ag£ "WVeiaclh
The wrench shown has instantaneous adjustment. It
is operated by placing the object to be turned between
the jaws and pressing the movable jaw in, or drawing it in
with the thumb-trigger under the handle, until it strikes
the object.
The grip is then maintained and increased by an auto-
matic locking clutch which acts as a cam and has a neutral
position that allows the jaw to move freely in and out.
The neutral and locking positions are automatic in action.
Automatic Quick-Acting Wrench
The clutch is made of one piece, and with the mechanical
principle involved, the harder the pull on the wrench the
tighter is the locking action. A slight pressure on the
clutch opens the jaw.
This type of wrench is made in several styles by the
Automatic Wrench Manufacturing Co., Boston, Mass.
&
Mouse Cnused Plant Shutdown — Recently a dead mouse
was discovered between the terminals of a 2200-volt oil switch
connected to a 2000-kw. generator in a small central station
in the Middle West. The engineer, while attempting to re-
move the mouse with a pair of sticks, accidentally got it
across two exposed parts of opposite polarity, thereby caus-
ing a short-circuit, which severely burned him, destroyed the
switch and shut down the plant.
April 13, 1915
P 0 \Y E K
505
Dnrecil-C^iirreinitt TIh\.iF<
Systems
llv Gordon Fox
SYNOPSIS — The different methods of equaliz-
ing the voltage on a three-wire system, with special
reference to the motor-generator set.
In the majority of plants in which direct current is
used there are two competing conditions affecting the
selection of the voltage. Economy in wiring for motor
service demands the highest voltage consistent with relia-
bility and safety, which is commonly considered to be 230
volts at the generator; whereas the lighting layout usual-
ly employs tungsten lamps on a 115-volt circuit. These con-
ditions have led to the extensive adoption of the three-
wire system. The 115-volt load will ordinarily be much
smaller than the 230-volt load, and the unbalancing of the
two sides of the low-voltage system is not likely to be
great if care be taken in making the wiring layout.
A number of different means are utilized for obtaining
the three-wire service and double voltage. The earliest
method is but little used. This employed two separate gen-
erators, each wound for 115 volts, placed in series. The
two machines combine in carrying the load on the outer
wires, while each handles its own 115-volt load. The
voltage regulation may be manual or automatic. Perhaps
the most common present-day application of this system
is that in which a generator having a double commutator
is used. The armature is wound with two separate 115-
volt windings, each connected to one of the commutators
on the opposite ends of the machine. The commutators
are connected in series for 230-volt service and their com-
mon point supplies the neutral. A machine of this kind
is represented in Fig. 1.
The most popular means for providing three-wire serv-
ice is the so called three-wire generator. This is, ordi-
narilv. a standard 230-volt machine in which the arma-
-^mmm^
Fig.
1. Three-Wire Generatoe with Double
Commutator
ture is tapped at two or more points ISO electrical degrees
apart, the taps being brought out to collector rings.
Where the unbalanced load is small two rings will suffice,
hut if the unbalancing is likely to be considerable it is
better to provide four rings and to tap the armature at
tour points 90 electrical degrees apart, so as to secure a
two-phase arrangement. Leads from the collector rings
arc brought out to a compensator that is merely a react-
ance coil. An alternating current is collected from the
Fig. 2. Connections fob Three-Wire Generatoe
rings and this current magnetizes the reactance coil, in-
ducing a counter voltage such that only a small magnetiz-
ing current flows across. The central point of the coil is
always the neutral of the system, since it is always half
way between symmetrical conductors of opposite polarity.
In this manner the half-voltage point is provided. In the
case of unbalanced toad a direct current passes through
the reactance coil and collector rings and part of the arm-
ature winding. In a two-phase arrangement the unbal-
anced load current is distributed over more armature coils,
so that heating is more uniform and voltage regulation is
better; hence, the preference for this type where unbal-
ancing is likely to be severe. Eecently, there have been
placed upon the market three-wire generators in which
the reactance coil is built into the spider of the armature
and the neutral is brought out from the center of this coil
by a single collector ring. This makes it possible to tap
the armature at more points for a multiphase reactance
coil, without the disadvantages of a multiplicity of col-
lector rings.
Three-wire generators are commonly designed and
rated for 10 per cent, unbalancing, although sometimes a
greater amount is specified. These generators may be
flat, drooping or overcompounded in their two-wire volt-
age characteristic, and they will ordinarily maintain the
neutral within a 5 per cent, range Three-wire generators
are connected as shown in Fig. 2, the shunt field being
connected across the armature and the series field being
divided into two sections, one-half in each side of the
line. In this manner the compounding effect is averaged
for unbalanced conditions. These machines may be oper-
ated in parallel the same as two-wire machines. However,
there must be two equalizers because of the division of
the series field. In adjusting the compounding of three-
506
P 0 W E E
Vol. 41, No. 15
wire generator? it is necessary to use similar german-sil-
ver shunts around each of the series fields, and in propor-
tioning the load division between two machines to operate
in parallel it is necessary to adjust the series circuit re-
sistances between both equalizers and busbars instead of
just upon one side, as for two-wire machines. When two-
wire machines are paralleled the ammeter shunts are
placed between the brushes and the series fields to prevent
cross-currents from one machine affecting the instruments
of the other.
It is possible to provide two-voltage service from a two-
wire system by the use of a series of storage batteries con-
nected across the outer lines with the neutral wire con-
nected to the middle point. On balanced load the bat-
tery floats across the line. If the load is unbalanced the
battery on the heavily loaded side discharges, while that
on the lightly loaded side charges. The combined charge
and discharge currents flow
through the neutral supplying
the unbalanced current. The
neutral voltage must shift
enough to cause this charge
and discharge action, so that
two combining to feed the extra current to the heavily
Loaded side. The motor armature carries a current greater
than that of the generator armature by an amount suffi-
cient to supply the losses of the set. When the machines
are running light their counter electromotive forces are
equal and are almost equivalent to the impressed voltage.
When an unbalanced load occurs on one side the voltage
of that side decreases so that it is less than the electro-
motive force of the balancer unit, and that side of the
set becomes a generator. The voltage across the other
unit increases so that its motor action is strengthened and
it is enabled to carry the generator load of its mate. It is
necessary that an appreciable shift of the neutral occur in
order to bring about this change, so that compound bal-
ancers are often used in order to secure better voltage
regulation.
Shunt-wound balancers having the fields in series or
parallel across the outer wires have practically constant
excitation for both units. If the central point of the
series-connected shinii fields 1"' connected to the service
neutral the excitation on the loaded, or generator, side is
weakened and that on the motor side is strengthened.
This tends to increase the motor electromotive force and
FIG.S FIG. 6
Pigs. 3 to 7. Different Boostek Pield Connections
the regulation is imperfect. The voltage can be adjusted
by means of end cells or by the use of a booster.
Double generators or three-wire machines are feasible
for plants generating their own power. If only 230-volt
power is available and three-wire service is desired, it is
necessary to provide a means for locally maintaining the
fixed neutral and providing unbalanced current. This is
commonly done by the use of some form of balancer.
There are several types of such sets, the more common
of which will be here discussed.
Motor-generator balancer sets are ordinarily composed
of duplicate units direct-coupled and mounted upon ;i
common bedplate. They may be either shunt or com-
pound wound and are sometimes equipped with interpoles.
The armatures are wound for half line voltage ami are
connected in series across the outer leads, their common
j mint being the neutral. The difference in the sets lies
mainly in the arrangement of the field connections.
Shunt-wound balancer units may have the fields wound
for either half voltage or full voltage. If wound for full
voltage the fields are paralleled, and if wound for half
voltage the fields may be in series with their central point
either connected to the neutral or isolated from it. Fig. 3
shows one connection for a shunt-wound balancer set.
With a balanced load both machines run light as motors.
With a greater load between the neutral and the positive
side, machine .1 acts as a generator and B as a motor, the
reduce the generator electromotive force. The regulation
with this arrangement is therefore poor. If the fields be
interchanged as in Fig. 4 the generator electromotive
force will be strengthened on the loaded side, tending to
maintain the voltage, while the counter electromotive
force of the motor is decreased, tending to speed it up,
run the generator faster, increase its electromotive force
and likewise maintain its voltage. Hence, this connection
gives the better voltage regulation.
The action of the compound-wound balancer set (Fig.
5) differs somewhat from the shunt-wound type. Here
the series field of the motor side opposes its shunt field,
while the series field on the generator side assists its shunt
field. ' Hence, the motor speed is maintained better or is
caused to increase, while the generator voltage is likewise
built up, tending toward good regulation. With the con-
nection shown in Fig. 5 the series field of the motor car-
ries more current than the series field of the generator,
since the motor armature circuit carries the current to
supply the losses of the set. The differential action upon
the motor is. therefore, strong and the motor is likely to
lie unstable and to race under heavy loads.
The arrangement shown in Fig. 6 causes both series
fields to carry the same unbalanced current, thereby im-
proving stability. That of Fig. 7, in which the series
fields are interchanged, places the generator series field
in the motor circuit and vi<<- vt mi. Since the motor arm-
April 13, 1916
POWER
507
ature current is greater than (ho generator armature cur-
rent, the cumulative action of the generator field carrying
motor current is stronger than the differential action of
the motor series field carrying generator current. The
excess of compounding is shifted from the motor to the
generator, the rise in speed under load is decreased, there
is less tendency to instability, and the voltage regulation
is improved.
The units composing a balancer set act alternately as
motor and generator. Therefore, the brushes must he set
in a central position corresponding to no-load neutral.
The neutral of a generator shifts in a direction with the
rotation, while that of a motor shifts against the rotation.
The brushes, therefore, cannot be located properly for
both conditions. Since the motor end carries the greater
load, it is well to give the brushes a slight motor lead to
favor this mode of operation. It is a characteristic of the
interpole motor or generator that the neutral remains
fixed for all loads. Therefore, the condition of inter-
changeability can well be met with interpole machines
and one position of the brushes will be correct for all
operating conditions. Without interpoles commutation is
a limiting feature and the units must be rated low to pre-
vent sparking under load with the brushes set at a com-
promise position. The tendency to instability is somewdiat
greater for interpole sets than for those without these
poles. The fact that the brushes of noninterpole machines
are behind the full-load neutral as a motor, tends to hold
down the load speed. In the interpole machine this effect
is removed and the general tendency to maintain speed
under load and to race is sometimes evidenced. The in-
terpoles of balancer sets may require shunting with ger-
man silver, the same as is done with ordinary interpole
motors.
The stability of compound-wound sets depends to some
extent upon the degree of compounding. Balancers are
ordinarily flat compounded or are adjusted for this de-
gree of compounding by means of german-silver resistance
shunted across their series fields. If a balancer set is
connected to long feeders it may be desirable to overcom-
pound to compensate for drop in the feeders. About 5
per cent, overcompounding is as much as can be safely
provided in most sets.
Balancer sets are started with the shunt fields con-
nected directly across the outer lines, with the center point
disconnected from the neutral. The two armatures are
connected in series through a starting box and are brought
up to speed without load. The central point of the fields
is then connected to the neutral of the set, and the voltage
is adjusted for equal division. Then the neutral of the
set is connected to the service neutral, and the unit is in
operation.
Balancer sets may be successfully operated in parallel,
but careful adjustment is necessary to secure even volt-
age regulation and proper load division. The units must
be connected in the same manner, so that their relative
speed and voltage-regulation characteristics will corre-
spond. If the units are compound-wound one or more
equalizers are necessary. If the fields are connected in
series in the neutral line, as in Fig. 6, one equalizer wdl
suffice. If they are connected as in Figs. 5 or 7 two equal-
izers will be required. Care must be taken to see that the
equalizers connect corresponding points. The series fields
should be connected on the inside next to the neutrals,
as shown; if connected outside and the units were paral-
leled, there would be cross-currents through the equalizers
into the leads to the line wires. Since the machine am-
meters, fuses or circuit-breakers are connected in these
leads, it is desirable that only the current for the unit
protected should be able to traverse this circuit. In paral-
leling balancer sets the same rules hold as in paralleling
any direct-current generators. If the series field circuits
between the equalizers and the neutral do not have resist-
ances inversely proportional to the machine ratings, then
it is necessary to insert german-silver resistances in the
series field circuit of that unit in which the resistance is
proportionately low.
Adjustments
There are a number of adjustments possible upon bal-
ancer sets. Consider the case of two compound-wound
interpole sets that are to be adjusted to regulate properly
and to run in parallel. First, the brushes of one end of
one set should be located upon neutral by running that
end as a motor upon half voltage and shifting the brushes
until the speed of rotation is the same in both directions
running light. This procedure is then repeated for the
other end of the set. Next, connect one end as a motor
and the other end as a generator, separately. Connect
the shunt fields as they will be connected in service. Load
the generator end and note the voltage and speed regula
tion. If the voltage regulation is not flat (assuming that
flat compounding is desired) then shunt both series fields
with similar german-silver shunts and adjust the shunts
until the desired result is approximately obtained. If
violent sparking or racing occurs it may be necessary to
shunt the interpoles also. The correct interpole shunt is
best found by using a low-reading voltmeter and "explor-
ing leads" which bridge from segment to segment of the
commutator and indicate the position of no voltage be-
tween bars. When the interpole is of the correct strength
the neutral will be at the same point both at no load and
full load.
With these preliminary adjustments made, the set may
be tried out as a balancer. The rheostats should be set
for equal voltage division at no load. Then full unbal-
anced load may be thrown first on one side and then on
the other and the voltage regulation noted. If it is not
exactly as desired a slight adjustment of the german-silver
shunts may be necessary. Possibly, one method of con-
nection will be found to give more satisfactory resides
than another. Both sets having been thus adjusted and
tried out singly, they may then be tried for parallel oper-
ation. If they fail to divide their load properly it may
be necessary to insert german-silver resistance in the
series field circuits of one of the units.
The method of protecting balancer sets depends upon
the importance of uninterrupted service and the delicacy
of the connected load with voltage change. Lamps are
more susceptible to injury through excessive voltage than
are motors. Fuses are quite frequently used in the line
leads of balancer sets. A circuit-breaker in the neutral
operating the circuit-breaker in the main lines by means
of a trip coil will cause severance of power when excessive
unbalanced load occurs, or a differential voltage relay may
be used to trip the line circuit-breaker when excessive
voltage inequality occurs.
The required rating of balancing equipment compared
to the connected load depends largely upon local condi-
tions. One side of a building may be dark while another
508
P OWEE
Vol. 11. No. L5
side is Light, or lights may be required in the central por-
tion of a room when not necessary near the windows.
Many causes contribute to unbalancing, and the amount
as compared to the load is rather difficult to determine.
It is desirable to maintain the unbalanced load in any
system as lov as possible. For this purpose throw-over
switches are sometimes provided, which make it possible
to transfer one or two two-wire circuit; from one side of
the system to the other to maintain an approximately bal-
anced condition. Where this is not done it may be pos-
sible to connect over some of the circuits from one side
of the system to the other to secure a better average bal-
Sometimes, three-wire switchboards for distribu-
tion circuits arc arranged to make interchange and rear-
rangement of circuits easy, so that balanced conditions
may be maintained even though circuits are added or
modified. Balancers are mosi frequently installed capable
of handling 10 per cent, unbalanced load, that is, a load
of one-tenth of the conna ted load all on one side of the
line. Balancer units must each have a capacity equal to
one-half of the rated unbalanced power, plus the losses >
the set.
Among the various types of multiport valves built
by the Harrison Safety Boiler Works, at 17th St. and
Allegheny Ave.. Philadelphia, Penn., is the multipart
flow valve for use with mixed-flow turbines. Its pn
Multipoet Flow Valve in Section
pose is to close communication between the exhaust line
from the engine and that stage of the turbine to which
the exhaust steam is admitted, whenever the pressure
in the latter falls below atmospheric.
In performing this function a vacuum is prevented in
the engine exhaust pipe, the presence of which would
result in the infiltration of air through leaks and past
piston-rod and valve-stem packing, which would result
in an overburdened condenser air pump.
In preventing the formation of a vacuum the drain-
ing nl' the receiver nil separator is net interfered with;
this also applies to the oil separators on heaters and
receivers in the engine exhaust line.
When a mixed-pressure turbine, one which receives
-team at two different pressures, usually live steam and
exhaust at about one or two pounds above atmosphere,
i< equipped with this flow valve, the exhaust steam is
automatically cut off as soon as the pressure in the ex-
haust line approaches a predetermined maximum, say
one pound above atmospheric. Tin- action causes the
flow of exhaust steam to back up and maintain a pro-
sure in the exhaust-steam main, live steam being used
by the turbine during the period the valve is closed.
A- -non as tlie exhaust-steam pressure builds up above
the predetermined point the flow valves open and the
live steam is cut out by the action of the governor.
The construction of the valve is shown herewith.
Each valve disk is connected to and balanced by a piston
of the same area. As the pressure in the turbine in-
termediate inlet acts on the top of the valve disk and on
the under side of the balanced piston, it has no effect
so long as the disk is closed. The pressure of the en-
gine exhaust acting on the lower side of the valve disk is
the pressure of the atmosphere acting on the
upper side of the balanced piston. Whenever the pres-
sure in the engine exhaust line exceeds the atmospheric
a certain amount, determined by the tension of the
spring pressing on the upper side of the disk, the valve
opens wide, because as soon as it leaves its seat the pres-
sure on the two sides of the balanced piston forces
it out against the spring. Striking of the piston is
prevented by buffer springs. When the pressure in the
turbine inlet opening drops near to atmospheric pressure
it, reinforced by the spring, forces the disk to its seat.
The valve thus prevents steam from flowing from the
engine exhaust line to the turbine unless the absolute
■ ire in the former exceeds a certain minimum. As
the balanced pistons are steam-sealed, no air is admitted
by them.
A Ohegvp C©^es°i5ra^ £©2° S&eatna
A nonconducting coating for low-pressure steam pipes and
the like, used for the past ten years with perfect satisfaction
by a Boulogne engineering firm, is described in a recent issue
of the "Revue Industrielle" as being conveniently applied and
cheap, while it can be prep"-ed by any steam user. It con-
sists of a mixture of wood sawdust with common starch, used
in a state of thick paste. If the surfaces to be covered are
well cleaned from all trace of grease, the adherence of the
paste is perfect for either cast or wrought iron. For copper
pipes there should be used a priming coat cr two of potter's
clay, mixed thin with water and laid on with a brush.
The sawdust is sifted to remove too large pieces, and mixed
with very thin starch. A mixture of two parts of wheat
starch with one part of rye starch is the best for this pur-
pose. It is the common practice to wind string spirally round
the pipes to be treated, keeping the spirals % in. apart to se-
cure adhesion to the first coat, which is about 14 in. thick.
When this is set, a second and third coat are successively ap-
plied, and so on until required thickness is attained. When it
is all dry, two or three coats of coal tar applied with a
brush will protect it from the weather.
California's Crude-Oil Production in 1914 was 103,623,695
bbl., against 97.S67.14S bbl. in 1913.
Water Power in Switzerland is conserved and utilized to
such an extent that in some towns not an ounce of coal is
used. Power, light and heat are furnished by water power.
April 13, 1915
POWE I!
509
iFelty Vsilv©s°°A IMsc^issiioini
By A. B. Cakhaht*
SYNOPSIS — Discusses a paper read by Pom/I:!
MacNicoll before the Institution of Engineers and
Shipbuilders, Scotland. This paper dealt chiefly
with a special safety ruin in which the passage
through the seat is nearly equal to the full mlet
area; the main or relief valve is not spring-loaded,
but is controlled by the action of a pilot valve. The
reviewer shows thai this, as well as other ideas, is
old, and that valves so constructed hare never been
successful. In America si nee 1860 only two prin-
ciples of construction have proved mechanically
satisfactory. Foreign practice compared with our
own.
It was before the Institution of Engineers and Ship-
builders in Scotland that Hazleton R. Robson presented
his paper in 1873 demonstrating the advantage, of springs
instead of dead weights and levers for loading safety
valves. This was several years after spring-loaded pop
safety valves had been introduced into this country.
Recently Donald MacNicoll, of Cockburns, Limited,
Glasgow, read a paper on safety-valve design before that
society, the paper dealing chiefly with tests of some spe-
cial "full-bore" safety valves recently applied to boilers
of destroyers in the British Navy. The interesting fea-
ture in these valves is that the passage through the seat
is practically equal to the full area of the inlet. But the
main relief valve is not spring-loaded and proportioned to
give automatic opening and closing, to make the amount
of blow-down in pressure adjustable, hut is in effect sim-
ply an adaption of the "compound" whistle valve common-
ly used in this country, having a steam piston whose opera-
tion is controlled by the action of an auxiliary pilot valve.
This idea is not new, for other valves operating upon
the same principle have been patented in Great Britain
and in this country; and as long ago as 1S71 Thomas
Adams read a paper before the same society, in (llasgow,
describing a relay type of safety valve patented by him,
in which the opening of the main relief valve was con-
trolled in similar manner by the action of a much smaller
valve. But none of these valves has ever been commer-
cially successful, and Mr. MacNicoll's paper indicates that
mechanical difficulties have been encountered in the latest
typo, and that much must still be accomplished before it
is as satisfactory as the safety valves commonly used in
this country. For example, he says: "All the valves lift
at about 7 lb. above the working pressure, drop or close
on their scats at the working pressure, ami are absolutely
tight at not more than 7 lb. below the latter."
Mr. MacNicoll's paper is interesting, but much of the
work he refers to has already been done in this country,
and much, if not all, that he describes as the latest en-
deavors in such experimental work in Great Britain, is
Bhown in various American natents issued twenty-five to
forty years ago.
The safety valves commonly used in Great Britain
are not of the type so familiar here. Instead of having
the "pop"' feature, most of them are valves without any
•Superintendent. Crosby Steam Gage & Valve Co.
expansion cnamber al the lip to give full initial lift, and
which depend upon long anil flexible springs to permit
sufficient opening at the seat. But although many in this
country know that the safety valves used abroad do not
afford as much relief in steam discharge as pop safety
valves, it is interesting to find the corroboration of tins
in Mr. MacNicoll's paper. Of safety valves commonly
made there, he says :
In connection with the Board of Trade type of valve, the
accumulation allowance or the amount of excess pressure
over the working pressure, when all stop valves and feed-
check valves are nhut and the specified amount of coal being
burnt, must not exceed 1 per cent, of the working- pressure.
The Admiralty allowance is 7 per cent., but with the feed
maintained; this latter, of course, is essential for water-tube
boilers. In most cases, with Board of Trade valves it has
been found that when the working- pressure exceeds 210 lb.
by gage, this allowance is exceeded.
Mr. MacNicoll says that a possible explanation of this
undue rise in pressure, indicating insufficient valve-dis-
charge capacity, lies in an insufficient escape-pipe area,
resulting in a throttling of the escaping steam, causing
back pressure on the valves and preventing them from lift-
ing properly.
This pressure has gone up as high as 40 lb„ whereas it
should never be more than about 15 It has been
suggested that in certain cases an accumulation test has been
stopped, owing to the accumulation having got considerably
beyond the allowance, and was still rising, the surveyor know-
ing at the same time that he was not justified in condemning
the valves, as the area was correct and compression of spring
in order, according to the Board of Trade formula. It would
appear in cases of this sort that the valve had not enough lift-
ing effort.
Concerning the lifts of such valves, he says:
It must be remembered, however, that American safety
valves have very different fittings from those manufactured
in this country. The rigid type of spring adopted in the
former giving less than % the diameter of the valve for ini-
tial compression, necessitates a carefully designed seat and
plate on the lid to lift the valve sufficiently The
short rigid spring is noticeable when compared with the pres-
ent British Board of Trade type Since the intro-
duction of the spring-loaded Board of Trade type of valve.
the design has altered but little It should In- se1
to lift at from 5 to 7 lb. above the working pressure, and when
properly constructed should drop on its seat at about the
working" pressure. The compression of the spring at the
blowoff pressure should be *4 the diameter of the valve.
He describes also the Admiralty type of spring-loaded
safety valve, in which "the specified initial compression
of the springs is equal to the diameter of the valve, or four
times the elasticity of the Board of Trade springs." Even
the great length of the springs, 111/2 or 13 coils, or more,
is not sufficient to insure proper lifting of the valves to
afford free steam discharge, as is further evidenced by
Mr. MacNicoll's quotation from a report of the trial, made
some five or six years ago, of an experimental type of
valve :
The ordinary spring-loaded safety valve is usually big
enough to take away all the steam that an ordinary boiler can
generate under ordinary firing conditions. Certain peculiarities
are inherent, but seem to have become accepted with resigna-
tion by engineers. For instance, the lift is usually indequate,
owing to pressure accumulating above the valves, and acting
downward en the larger area provided by the lip
When the valves lift, the rush of steam past the lip prevents
the valve closing until the pressure in the boiler has fallen
considerably below the working pressure. This is known as
"drop," and may amount to as much as 10 per cent, of the
working pressure. It is usually looked upon as inevitable,
but is a serious matter on a full-power trial where the loss
010
l'OW EB
Vol. 41, No. 15
of water is measured and when il is important to maintain
full boiler pressure over a Ions period, hence the practice of
bavins a man told off to watch if any valve lifts, and to at
once tap it down again on to its seat.
Concerning the lift of safety valves, he comments upon
the experiments made a few years ago, and says:
Although the balance-disk valve was not considered satis-
factory, it was agreed that a valve giving a greater lift than
the ordinary type was desirable. The ordinary type of valve
lifts about A of its diameter, while the Gibson valve lifted ,'s.
Referring to the experiments made in 1874, he -ays:
It is suggested that with a specially designed Cockburn
valve it reached the full amount — namely. '4 of the diameter —
but this is not likely, and certainly a rule proposed by the
committee allowed for a lift of only Vsn of the diameter.
This would seem to indicate that foreign safety valves,
in spite of the long' springs, do not have the excessive lifts
with which they are sometimes credited in discussions of
the subject. The duty under our present tariff is not high
enough to prevent the importation of safety valves from
abroad if they were desired. Some manufacturers in this
country are often called upon to duplicate such valves for
marine boilers in special cases, but even this intimate
knowledge of their construction has not led to their gen-
eral introduction here. One statement made by Mr. Mac-
Nicoll concerning some of the valves tested, using large
springs made according to the Admiralty rule, indicates
that the long springs have disadvantages that might de-
velop into exaggerated difficulties under American condi-
tions of service:
In torpedo-boat-destroyer work also, the large springs had
been found to be a source of trouble; excessive vibration
keeping the springs continually on the dance, and serious
leakage consequently ensuing.
Mr. MacNicoll describes the experiments of J. II. Gib-
son, of the firm of builders of the British torpedo boat de-
stroyer "Cossack," which was one of the first vessels burn-
ing oil fuel in which serious difficulty was experienced
with the ordinary Admiralty safety valves:
During the accumulation trial the steam pressure rose to
a dangerous extent with the pointer of the gage going up
rapidly. To prevent an accident the easing gear was applied.
It was observed that it required only a very small additional
lift to the valves, somewhere about yM in., to keep the ac-
cumulation within the specified amount While
the new valves were being manufactured, he carried out an
experiment on one of the original valves. A small steam
cylinder fitted with a piston was attached to the boiler shell
in the vicinity of the safety valve. The piston was attached
to the easing gear in such a manner that on the piston moving
outward the valves were eased. The bottom of the cylinder
was connected with the waste-steam space of the safety
valve. The effect was that the excessive pressure in the
waste-steam space assisted the valves to lift instead of pre-
venting them from doing so.
This experimental valve was described, at the time, in
Engineering (London), Feb. 26, 1909, and mentioned by
the writer in an article in Power, Mar. 23, 1909. The
comment is made that "the trials were most satisfactory.*'
but subsequent events cast doubt upon this conclusion. It
is apparent that only one such valve was ever made; and
the idea of utilizing the excessive back-pressure in operat-
ing a lever to overcome its harmful effects seems too much
like lifting one's self by the boot-straps. In the torpedo
boat destroyer "Swift," constructed later by the same firm,
each safety valve, "instead of having an external cylinder
as previously mentioned, was fitted with a balancing pis-
ton, or disk, which neutralized the effect of back-pressure
in the valve casing." This device was sufficient to over-
come the difficulty with the safety valves, as far as the
accumulation allowance under test was concerned.
But this idea also, of a larger disk fixed to the valve
spindle, is not new, for it is shown in many of the older
patents. A somewhat similar scheme for using the back-
pressure to give extra lift to the valve was an important,
feature in the old "Crosby-Meady" muffled locomotive pop
valve of lss">. that showed lift of 1/4 in. This had a con-
siderable sale thirty years ago. In justification of such a
device, the report upon the tests of these experimental
valves says :
To obviate the objectionable action of this pressure [the
back pressure in the valve casing] and. if possible, to make
it perform useful work is the object of this invention. By
making the balancing disk equal in effective area to the valve,
the effect of the fluctuating pressure in the valve box is elim-
inated, and the valve lifts gradually and quietly to the full
amount permitted by the compression of the spring, and the
allowable accumulation The removal of the lips
from the valve and seat steadies the action of the valve, and
prevents "beating" or "chattering," thus increasing its life
or period of steam-tightness.
"Gradually and i/iiictli/" in the original report empha-
>ize the desirability, sometimes too little appreciated, of
the practical advantages of smooth and quiet operation of
a boiler safety valve, as compared with the sudden and
violent explosiveness that sometimes results from an ef-
fort to obtain an excessive rate of discharge or an in-
stantaneous relief. However, it is evident that the de-
sired results were not fully realized, for Mr. MacNicoll
says :
Subsequently, Messrs. Cockburns made valves of this type,
but it is regretted that while amply meeting with accumula-
tion conditions, the question of when the valves commenced
to lift and when they shut off tight was a most vexed one.
With the ordinary type of valve the lift is definite — a distinct
"pop" is heard, although simmering may have taken place
for some time previously. With the balance-disk type the
first slight feather at the waste-steam pipe was taken as the
commencement of lift, this gradually increasing till the valves
were blowing full; the range of pressure every time the valves
lifted was about 30 lb. per square inch. Similarly, on the
valves closing again the range was 35 or 40 lb. per square
inch. These valves were refitted repeatedly, with no better-
ment.
Mr. MacNicoll describes the difficulty they had with
continued leakage at the valve seat (attributed to distor-
tion of the seats of the valves, which were 3l/2-in. size)
and mentions the improvement in the behavior of the
valves after they were fitted with a different type of disk,
but makes the significant statement:
After this they never gave satisfaction, and about IS
months thereafter were replaced. Subsequently, it was found
that this type of valve had been used in the United States for
a considerable time.
The next form of experimental valve tried was upon
the same principle, but had a much larger piston fitted
above the valve disk, so that back pressure in the body
would force the disk further from its seat. It does not
seem logical to have developed this idea so far; for the
real purpose of any safety valve employed should have
been to discharge the escaping steam, for the relief of the
boiler, rather than to throttle the discharge pipe to gain
more lifting power inside the valve body. For of what use
is it to gain greater lift and larger opening at the valve
seat if free discharge of the steam from the valve casing
is not permitted ? This valve appears to have been inoper-
ative except under special conditions. To again quote Mr.
MacNicoll:
The piston was made considerably larger than the valve.
and a stop valve was fitted to the outlet as shown, so as to
maintain any desired pressure in the waste-steam space. This
valve could be made to give a lift of M of its diameter under
favorable conditions, but was found to be somewhat erratic
in its action, and the slightest increase to the lift on the
stop valve from that which allowed of full lift to occur
in the safety valve prevented the latter from lifting more
April 13, L915
1' ( ) \V B r?
511
than a very small amount. The drop also was very inconstant
— generally the valve was considered unsatisfactory.
As an alternative device, intended as an improvement
upon tlir experiments described, a compound valve was
devised, in whirl] the opening of a small spring-loaded
pilot valve allowed the steam behind a piston (if larger
area to force open a main relief valve against the boiler
pressure.
Such valves are interesting in principle, but have been
described in earlj i . S. patents; for example, in the pat-
ents to Shepard in 1873, to Anderson in 187 7. and to
s. -i i\ I'll in 187!), as well as in that to Collier in 1882. Many
variations in the mechanical embodiment of the same idea
have been tried, lmt bave never been able to displace the
familiar automatic safety valve of the "pop" type. In
the discussion of Mr. MacNicoll's paper. R. A. .McLaren
stated that he had designed a valve on much the same prin-
ciple between twenty and t\\cnty-live years ago.
George W. Richardson, the inventor of one of the early
successful American safety valves, was granted his first
patent in 1866, and this was followed by another in 1869,
the papers of which describe the adjustable ring for regu-
lating the amount of blowdown in boiler pressure. Among
the numerous safety valves shown in United States patents
since 18fi0, only two fundamental principles of construc-
tion have proven mechanically satisfactory. These are
Richardson's idea of an overhanging lip and stricture
ring, forming an adjustable "huddling chamber" sur-
rounding the valve seat, and Crosby's opposite plan of us-
ing a flat, double seat and controlling the blow-down by
regulation of the small part of the discharge that is by-
passed through a central chamber beneath the disk, in-
stead of at the valve seat. All the later commercially
successful improvements have been based upon the ideas
of one or the other of these two pioneers.
One difficulty met with in the designing of any spri un-
loaded pop safety valve that is to Lie self-regulating and
automatic in operation, is the limitation upon the amount
of spring compression and lift of the valve that can be eas-
ily attained without sacrifice of some of the desirable
characteristics of such valves. Therefore, the devising of
other forms of boiler relief valves has been a favorite
field for inventors' schemes. Even during the discussion
of Mr. Robson's original paper before the Institution in
Glasgow in 1873, David Rowan remarked: "When we
have a safety valve which will lift one-fourth of its diam-
eter, or to give an area equal to the diameter of the valve,
then the question will he put on a scientific basis."' This
underlying idea has persisted ever since, and is rediscov-
ered in turn by each one who gives original thought to
the subject. This is doubtless the reason why so many
have experimented with various forms of balanced-pi-ton
and relay valves, which apparently would give "full open-
ing" for boiler relief.
A reliable automatic safety valve must do more than
merely discharge steam. In fact, the opening of a relief
valve to give "full discharge" is one of the simplest details
in the problem, and easiest of solution. Even Mr. Rowan,
back in 1873. said that it "could easily be done.'' The
greatest difficulty arises in getting the valve closed again.
The wide range of blow-down commonly accepted in for-
eign practice, or in the operation of valves on marine boil-
ers, would not be countenanced by operating engineers in
this country, after their experience with modern pop safety
valves.
Comment.- appearing incidentally in Mr. MacNicoll's
paper ate especially interesting as indicating that some of
the safety-valve specifications appealing in the new A. S.
M. E. Code arc wise and proper. For example, he em-
phasizes the Lesson drawn from some of the safety-valve
experiments, that discharge piping of ample size must be
provided lor carrying away the exhaust steam from the
safety valve. In connection with the subject of springs
for -a lit ■-. valves lie sa\ s :
There appears to be a broad rule, however, for determin-
ing a sal'.' spring — that is. one which will remain for any
length of time under a load with the coils almost touching.
maintain this compression, and resume its free length when
the load is removed.
The recently approved specifications of the A. S. M. E.
on this subject are intended to accomplish this to insure
that springs used in safety valves shall not under any cir-
cumstances take any permanent set.
After describing in detail the construction and method
of operation of the piston type of valves in the latest ex-
periments, Mr. MacMcoll comments:
If they are placed near the top of the boiler and have
easy leads in the waste-steam pipe, no vibration or movement
will take place. If, however, they are fitted with internal
pipes there is a tendency to vibration; apart from this, in-
ternal pipes are most dangerous when fitted to safety valves,
and serve no useful purpose.
This seems to be further confirmation of the wisdom of
the provision in the A. S. M. E. Code that safety valves
shall be connected directly to the shell of the boiler.
There has been some discussion concerning the most
practicable method of calculating the total boiler evapora-
tion for which safety valves should be provided, and upon
this point one comment of Mr. MacNicoll's is pertinent:
With the advent of oil fuel in the Navy, the size of safety
valves based on a formula taking coal as a factor proved
altogether inadequate. It appears somewhat singular that the
formulas for arriving at the size of safety valves, in the case
of the Board of Trade rule, should be derived from area of fire
grate and steam pressure, and in connection with the Ad-
miralty, from heating surface and steam pressure. One would
have thought the factors necessarily presenting themselves
would have been evaporation and steam pressure
Turning to the rule formulated by the Board of Trade, it
appears somewhat strange that they should have decided on
a rule which gives a "disk area" and not a "clear area" for
the escape of steam As already stated, it now
appears that it would have been better had the Board of
Trade rule settled the actual area for discharge. During the
experiments by the committee it was found that the lift was
\ . ■ 1 1 . i hi -
Tlhe KHoirsepow©!? ©If a (GsiimrmoEa
A matter of speculation likely to interest engineers is
the enormous energy or horsepower developed in the
breech of a big modern cannon discharging a projectile
weighing, say 1850 lb., at a velocity of 2000 ft. per sec,
when
W = 1S50 lb.:
V = 2000 ft. ;
g= 32.16.
wv*
The formula
E =
*9
gives I L0,000,000 I't.-lb.
This amount of work must be accomplished during the
projectile's travel in the gun, probably not over 1/100 of a
second. Therefore,
110,000,000 X 100
— — — - = 30,000,000 Aw.
550 r
or in another way. the vertical distance a body would have
512
r 0 AY B T?
Vol. 41, No. 15
to fall to attain a velocity of 2000 ft. per sec at a uniform
rate of acceleration due to gravity would lie about (iO.OOO
ft. A projectile weighing 1850 lb., falling this distance
would generate
L850 X 60,000 = 111,000,000 ft.-lh. of energy.
The same amount of energy would be required to produce
the same velocity at the muzzle of a cannon and represent
in horsepavi er
111.000.000 -f- 550 = 200,000+ hp.
if done in one second; but the actual time is probably
about as the length of the gun is to the velocity, or 20 to
2000. or Vioo of a second. The energy exerted for the
shorter period must be 100 times greater, or equal to
20.000,000 hp.
SStieff'
SS.e^mlsitos'
The Foster automatic feed-water regulator is designed
to maintain water at the predetermined height. Nor-
mally, the water in the boiler or water column >eals the
end of the pipe leading to the top of the expansion
tube, so that steam is excluded therefrom and the tube
is cool or contracted. In this condition of the expan-
sion tube the long arm of. the bell-crank lever .1. Fig. 1,
is free to swing outward and allows the weight to de-
PP*3
Fig. 1. Details of the Fosteb Feed-Watek Regulatoe
press the arm of the lower bell crank B, so as to slide
the valve C downward into a closed position, cutting off
and preventing water from entering the boiler through
the feed line.
When the water recedes below the predetermined level,
it uncovers the opening in the pipe leading from the
water column to the top of the expansion tube and per-
mits steam to enter it. This heats and expands tube D,
carrying the adjusting screw E, which can be set for
any desired variation, upward against the short arm of
tin' lull-crank lexer .1. thus swinging the long arm of
the latter inward or toward the expansion tube. This
carries the lower bell-crank lever B and raises the weight,
drawing the valve C upward, opening the main feed
Fig. 2. Regulatob and Connections
valve, and permitting water to flow through the feed
pipe into the boiler. The flow continues until steam
is again cut off from the expansion tube D, allowing the
latter to contract sufficiently to close the valve C. Fig.
2 shows the regulator and pump connections. This reg-
ulator is manufactured by the Foster Engineering Co.,
119 Monroe St.. Newark, N. J.
tales
The British Board of Trade rule for the thickness of brazed
copper steam pipes is
D X P
Kono
in which
T = Thickness of plate in fractions of an inch;
D = Diameter of pipe in inches;
P = Working pressure in pounds per square inch.
For working pressure of brazed copper steam pipes,
6000 X (T + ,'„)
P =
D
To find the weight of copper pipes.
W = 3.03 (D= — d-); or 3.03 (D + d) X (D — d)
in which
W = Weight per lineal foot of pipe in pounds;
D — External diameter of pipe in inches;
d = Internal diameter of pipe in inches;
3.03 = A constant.
To find the weight of brass pipes per lineal foot,
W = 2.82 (D= — &-); or 2.82 (D + d) X (D — d)
in which
W = Weight of pipe per lineal foot in pounds;
D = External diameter of pipe in inches;
d = Internal diameter of pipe in inches;
2.S2 = A constant.
April 13, 1915
gpnilUI 1 1 Ulimilllliri lllft'M" ' m i m»nnm i n n n 1111cm tin i n i m iihhiiiiiiihii n i unnHiim I II m UUIII'JII
POWER
513
iiiii!I|iiiiiiiiiiiii>iiiuiiiiuiiiii;iiiiiiiiiiiiiiiiii[iiiiiiiiiiiiiiii
siiiiiiiiMiiHiiniiiiiiiiii'iiiiimiin;!! iiii»:iiuij=
I
dlitlori
...'"■ .
There have been ructions in the good old Common-
wealth of Massachusetts for the past few weeks. A power-
fully organized attack has been made upon the existing
law by the employers, who complain that it contains, in
addition to its provisions for safety, features that impose
unnecessary hardships upon the employees and useless
burden upon the manufacturers; that it recognizes no
difference in the risk of operation between steam engines
and steam boilers; that it fails to limit the Bcope of ex-
aminations and permits the requirement of knowledge of
the principles of design in the examination of applicants
for license to operate, of a knowledge of the principles of
boiler design in an examination for a permit to operate
engines, and permits the examiner to require involved
mathematical calculation, thereby denying employment
to competent men.
There have been, for a long time, evidences of friction
between the employing and the laboring interests, over the
interpretation and administration of the law. Shall a
single licensed man in responsible charge suffice for a
plant, or shall everybody, down to the coalpasser, be re-
quired to have a license?
Shall the examiner simply satisfy himself that a man
knows enough to keep water in the boiler and the safety
valve clear, or shall he assure himself, broadly, of a man's
ability as an engineer and of his general understanding
of the principles of and of his familiarity with, the ap-
paratus involved, in the processes of the oversight of
which he seeks responsible charge?
Shall an inspector fearlessly and impartially enforce
the provisions of the law and the Code, or must he handle
friends of the appointing powers with particular consid-
eration to hold his job?
Stories are told of an inspector who made seventy-three
arrests and got seventy-two convictions, whose pernicious
activity was checked by laying him off for three months
"for using language unbecoming an official." On the
other hand, it is maintained that the inspectors appointed
by the District Police do not all know too much about
boilers themselves.
The manufacturers, therefore, had a bill, known as
House Bill Xo. 1111, introduced, which provided that
with every licensed person employed there may be one
unlicensed person employed, who, in the presence and
under the personal direction of the licensed person, might
operate steam boilers and their appurtenances; defined
what was meant by "control," "operation," "have charge
of," etc., as used in signifying where Licensed men were
required, etc. The bill also required a different examina-
tion and license for a man who was to have charge of en-
gines than for one who was to have charge of boilers, and
provided a practical examination for both, with the priv-
ilege of having present an observer who might take notes.
This bill met with strenuous opposition from the engi-
neers, and on Mar. 22 the Governor addressed a message
to the Legislature, in the course of which he said:
As you are doubtless aware, there has been for some years
a serious controversy between the representatives of organized
labor and the representatives of the manufacturing interests,
in regard to some of the provisions of the existing law
relative to engineers' and firemen's licenses and in regard
to the enforcement of law by the Boiler Inspection Depart-
ment of the District Police. I am informed that after
repeated conferences and long discussions these differences
have now been amicably adjusted and an agreement reached
whereby the opposition of organized labor to House Bill No.
1111, amending the law regarding engineers' and firemen's
licenses, is withdrawn and the support of the manufacturers
to the bill herewith transmitted is accorded.
The bill "herew ith transmitted" takes the inspection of
boilers and the examination of engineers entirely out of
the hands of the District Police and establishes a Bureau
of Steam Engineering and Inspection to take care of it.
Bill Xo. 1111 was withdrawn by mutual consent of a
committee composed of engineers and manufacturers, and
in its place another bill has been drawn up, amending the
present law so as to overcome the objections of the manu-
facturers without prejudice to the engineer.
Hew Metlhodls ©if Ps*©dl'aacain\§>
Gas ©Mime
Widespread interest has been created within the past
few weeks by reports in the daily press of discoveries
calculated to greatly increase the supply of gasoline,
besides making available benzol and toluol, which here-
tofore have been produced from coal tar. The toluol
is an important ingredient in modern high explosives.
First came the announcement of Dr. Snelling's process,
to be followed closely by that of Dr. Eittman, and fin-
ally the information that Edison had started a plant
for the production of benzol and a number of residual
product.-, ordinarily imported from Germany but now
cut off as a result of the war.
In Dr. Snelling's process synthetic crude oil is pro-
duced from hydrocarbons such as kerosene, fuel oil,
lubricating oil and paraffin (themselves originally ob-
tained from crude oil), by heating in an air-tight vessel
or "bomb" until about eight hundred pounds pressure
is reached, the substance occupying only about three-
elevenths the volume of the bomb. The action appears
to consist of a rearrangement of the atoms, and upon
cooling, crude oil is obtained. This synthetic crude oil,
when subjected to fractional distillation, will give off
approximately fifteen per cent, gasoline. Thus the proc-
ess is cyclic and through repetition can be made to
yield a large proportion of gasoline.
Dr. Rittman's process, it appears, depends upon
"cracking," but the petroleum is first vaporized and then
subjected to the necessary pressures and temperatures
for the production of gasoline, or further, benzol and
toluol. Fifty to seventy-five per cent, of gasoline is
said to be attainable, besides the other products.
The Edison process has not been made public.
Both Dr. Snelling's and Dr. Rittman's processes are
still in the laboratory stage and it would be useless to
make any predictions as to their probable effect on the
51-4
POWEB
Vol. 11, No. 15
fuel and byproduct situation in this country. However,
lest some be misled into the belief that the relatively
large percentage of gasoline thus obtainable will greatly
affect the price of that fuel, it may be pointed out that
in the Burton process, controlled and employed by the
Standard Oil Co., about seventy per cent, of the crude
may be converted into gasoline. It is understood, how-
ever, that ordinarily not ovei forty to forty-five per cent,
is extracted, not because of any mechanical or chemical
difficulties, but solely for commercial reasons. That is,
if the market demands are such as to make it more profit-
able to sell forty per cent, of the heat units of the crude
in the form of gasoline, thirty per cent, as kerosene,
twenty per cent, as fuel oil, etc., the process will be
adapted to meet these conditions. If the market de-
mands for these products are in some other ratio, the
condition will be met. In other words, the Burton pro-
cess is used as a "balance wheel" to suit the market and
effect the most profitable production.
Now, if the new processes are developed commercially
will they not to a large extent serve a similar purpose?
As an economic problem it is not reasonable to suppose
that the production of gasoline will be increased to such
an extent as to greatly lower its price to the consumer
if the demand for the heavier oils for use in the oil
engine is such as to make an increased production profit-
able; similarly with the other distillates.
Perhaps the most important feature of Dr. Eittman's
discovery, as concerns the public, lies in the fact that
it is government property and as such will lie free to
all. Thus the independent refiners may take advantage
of it and will be able to compete with the Standard.
While they will also be governed largely by market de-
mands, they may serve as a cheek against any artifi-
cial boosting of prices or demands; provided, of course,
their supply is unhampered. Again, the production of
the toluol and the other residuals, while possibly unable
to compete with the imported coal-tar products after
normal conditions have been resumed, will neverthe-
less serve as an important asset in time of necessity.
Osftlmig Motor late
Inadequate records of local motor installations are a
common source of delay in power plants in which the
operating engineer has jurisdiction over electrical as well
as steam equipment. Trusting to memory as to the size
and speed of individual motors may be all right when only
a few are in service, but in a large plant it pays to keep
an uptodate card or loose-leaf record showing in detail
exactly what each motor is doing. The necessary data
include the horsepower rating of each motor, its pulley
diameter and face, the speed at normal rating, and the
pulley and speed particulars of the main shaft of ma-
chinery or grouped tools driven, pinion and gear sizes,
and the number, make and capacity of the machines run
by each motor. In a representative mill installation
where this information is maintained by the plant engi-
neer each motor is provided with an index card bearing
the above particulars; and in addition, space is left for
recording test data, so that at any time the plant manager
can be informed accurately of the load on any motor, just
how many machines it is driving, and how many it should
drive if loaded to its full rating. With modern induction
motors this plant runs its machine drives in many cases
on the basis of loading individual motors from fifteen to
twenty-five per cent, beyond their nameplate rating. In
case of any desired change in tool arrangement, alteration
of slock or other modification of the installation, the engi-
neer's record shows at a glance just what the condition of
each drive was at the last test and indicates the course to
be followed with reference to the addition of machines to
any group or the substitution of a motor of different size
to meet the proposed load conditions. Every lineshat't in
tin' mill is identified by a letter corresponding to the card
record of the motors, and the amount id' time saved in
making estimates of local power requirements is surpris-
ing, compared with the ordinary method of making a
new power survey every time any question of importance
arises in connection with the capacity of the motors
S
Judging from the evidence, the average writer of speci-
fications has little knowledge id' piping work, but a great
desire to cat. li the unwily bidder. Many specifications
are voluminous, and many and devious are the methods
used to avoid telling the bidder all that he should know
in order that his bid may be intelligent and his chance
of loss minimized. At the other extreme are the specifi-
cations that arc manifestly lacking in detail.
Specifications of cither kind are neither creditable to
the architect or engineer who wrote them, nor valuable
to the owner, nor are they in the interest of clean compe-
tition. Rather do they work against the honest bidder,
who justly refuses to spend his time doing the architect's
work, knowing from experience that others competing
with him, with less respect for their trade, are only too
willing to propose a system that will just pass. The hon-
es1 bidder and the owner arc the injured parties, and
the less conscientious bidder has a field for his activities.
It is true that piping work must conform to certain regu-
lations, but the opportunity to skimp the job is ever pres-
ent, and in heating work the chances arc still greater and
the use id' inferior material more frequent.
After the contract is secured, there is invariably con-
stant wrangling over the interpretation, both parties put-
ting forth good reasons for their contradictory renderings,
the owner trying to get the best service at the least expense
and the contractor striving his utmost to make the con-
tract call for the least material and labor. There is also
room for argument regarding the acceptance of material
supposedly "equal" to that called for, the final judgment
being usually left to the representative of the architect,
whose experience in such matters is by no means commen-
surate with the dignity of the position he is to fill.
Why should specifications not be written with precision,
so as to be deserving of respect, inspiring the desire for
clean competition, with scant opportunity for work that
will barely pass?
m
The advocates of the Water Power Trust claim that it is
better that the water powers should be developed, even at
the expense of turning them over to private capital for this
purpose, than that they should lie dormant and the fast
diminishing coal supply he burned up to produce the
power which they might generate. It is probably better
that anthracite coal should be mined and supplied to the
public even at eight dollars a ton than that it should lie
in the ground, but it would be a whole lot better to have it
mined by the people themselves and made available at half
tlie cost. Don't let the wdiite coal get whore the black is.
April 13, L915 PO W E I.' 515
giiiiiiiiiiiinii ' i uii i . i minium in mi ;, miniums
Corirespoinidleimo
r mmiiimmimmmii
It takes me from twenty to twenty-five minutes to get
to my work. One morning, across from me in the car
was a fellow who was very much engrossed in reading
some article in Power. Next to him was another man
Bound asleep, with his feet stink out in the aisle. The
former seemed to he enlightened on some subject which
had puzzled him. The other, dead to the world, was
keeping passengers busy stepping over his feet.
At the shop I again noticed the same two men. The
"dead one" was at the drinking tank, complaining to a
fellow workman about the small pay he was getting; the
other was busily engaged with his work. I learned that
they were getting the same pay, although the dead one
had worked twice as long at tin- place. I went my way.
satisfied that I had a mirror worth holding up to my fel-
low readers.
Milton W. Elmendorf.
Wilkinsburg, Perm,
[The cartoon in this issue was drawn from a sketch
accompanying the above letter. — Editor.]
\UiniaifiiOw ILiragaEaes
I have read with great interest tin- letter in the Mar.
30 issue of Power, criticizing Professor Stumpf's article
on the uniflow engine. In view of the distance of Pro-
fessor Stumpf and the delay in the mails due to the war. I
take the liberty of replying to this article. I was asso-
ciated with Professor Stumpf during the introduction "I'
the uniflow engine in Germany and am familiar with his
work.
The question at issue seems to he whether or not uniflow
engines should he fitted with auxiliary exhaust valves.
There can he no question that condensing engines are bet-
ter without these valves. They not only add to the mechan-
ism and complication of the machine, but they decrease the
thermal efficiency even if locked closed and absolutely
tight, as they must have some clearance; and as the steam
remaining in this clearance is not raised in pressure by
compression, it causes a much greater loss than the same
amount of clearance at the end of the stroke would.
It is true that when uniflow engines wen.- first brought
out several cylinders were wrecked, but these were cracked
by initial strains due to improper design and not by high
compression. There have been two accidents in this
country that were probably due to excessive compression
caused by loss of vacuum, but these engines had Corliss
valves which could not lift sufficiently to relieve the pres-
sure, and they broke at the cylinder heads and not
through the exhaust ports.
The fact that there is in successful operation in Eu-
rope more than 600,000 hp. of condensing uniflow en-
gines without auxiliary exhaust valves and that engine
builders continue to leave them off, is proof that they arc
not required for safety. Since the first engines were buill
there has n,,t been a single accident of the kind mentioned
above with an engine built from Professor Stumpf's de-
sign.
The question of ooncondensing engines presents a dif-
ferent problem. The uniflow engine requires large clear-
ance and consequent loss (Fig. 8 of the article in question
is incorrect and misleading, as may be seen from the ac-
companying cut, in which both cards have the same admis-
sion : the loss is by no means the shaded area B, as the
description of Pig. 8 states), hut this loss decreases with
high steam pressures and low back pressures. Aux-
iliary exhaust valve- also cause additional losses due
to partially defeating the uniflow advantage and the
additional clearance as mentioned above. These losses
increase with high steam pressures and low back pres-
sures. We therefore have two engines — one in which
"" 'Ac/mAss/o/7
Auxiliary Exhaust on Uniflow Engines
the efficiency increases as the steam pressure in-
creases and the back pressure decreases, and the other in
which the efficiency decreases as the steam pressure in-
creases and the back pressure decreases. The engine with
auxiliary exhaust valves mu-t be more efficient at low
steam pressures and high back pressures, and the engine
without, auxiliary valves must be more efficient at high
steam pressures and low back pressures.
^ here these curves of efficiency cross cannot be accu-
rately determined until there are more data of authentic
trials of these types available than at present, but from
the data at hand it is probably somewhere between steam
pressures of 120 and 150 lb. at atmospheric exhaust.
It must not be understood that it is accessary only to
build an engine on the uniflow principle to make it eco-
nomical. There is just as much difference between uni-
flow engines as between those of any other type, and the
engine must be properly designed to get good results.
I am not surprised that ""One American builder, after
having built and thoroughly tested a ooncondensing uni-
flow engine having no auxiliary exhaust valves, now refuses
to bid on the uniflow engine for noncondensing service."
if he cannot build an engine which will do better than
•.' 1 1 | lb. of -team per hp.-hr. If this engine had been
properly designed for the work, it would have done a1
least 25 per cent, better.
516
POW I. I!
41, No. 15
One test does no! prove anything, especially if the re-
sults are negative, and it is of no value whatever unless
all conditions are noted.
There have been many trials by disinterested experts,
and records as low as 1 I lb. of steam per i.hp.-hr. (non-
condensing) have been made with uniflow engines without
auxiliary halves, and these records bave never been ap-
proached with engines fitted with auxiliary exhaust
valves.
W. Ttjenwald,
Syracuse, X. Y.
$400; excavating (800 yd.), $250; concrete and labor,
$1250; iron pipes and nozzles, $550; total, $2150.
The cos! of a cooling tower with fan to perform the
same amount of work was estimated at $5000. The brass
High efficiency, low first cost, durability and attractive-
ness are the chief merits claimed for the cooling pond
described herewith and illustrated in Figs. 1 and 2. The
jets of spraying water have all the charm of a collection
of fountains — a sight incomparable with the old-style
towers or the newer masonry towers. The device described
belongs to the Rea Patterson Milling Co., of Coffeyville,
Kan.
Besides the pleasing appearance, the next important
feature of this dei ice is its durability. Being all iron and
concrete, there is practically no wear and nothing to re-
quire attention or get out of order, and there is no danger
from wind storms. Fifteen pounds" pressure is all thai
is required to operate the spray. The loss by evaporation
is about the same as in other spray cooling devices.
This cooler handles 1500 gal. per min., reducing the
water to normal temperature. This is regulated by the
pressure, and thereby the height to which the spray rises;
the humidity of the atmosphere is also a governing factor.
The cost of the plant was as follows (estimated) : Ground,
Fig. 2. Plan and Elevatios oi Cooling Pond
nozzles are of special make and cost $500 for the
twenty used. The bottom of the pond is lined with five
inches of concrete and the depth of water is about three
feet. The concrete columns supporting the pipes are 12
in. square in cross-section, and they are spaced 12 ft. 0
Fin. i. Cooling Pond Designed and Installed i;y the Plant's Operating Engineer
April 13, 1915
P 0 W E R
517
in. apart on straight runs
service about a year.
Coffeyville, Kan.
The cooling pond has I n in
J. I. Blaib.
Pl^tt© VsiS^y© fos*
HngIh=S
essosrs
I have read, with much interest, Mr. MacFadden's ar-
ticle on "Plate Valves for High-Speed Air Compressors,"
appearing in the Mar. 16 issue, and I wish especially to
refer to the statement that it requires less power to oper-
ate these valves than it does other types of valves.
I have heard several discussions on the actual pressure
required to open inlet and discharge plate valves and there
seems to be a wide difference of opinion as to the actual
pressure required. Many of us are interested in this sub-
jeet and would be interested to know if there are any
actual data by which we ran determine the pressure re-
quired to open these valves. I presume that this, to a
certain extent, depends upon the design of the valve, but
authentic published data will be highly interesting.
J. I. Blouxt.
Birmingham, Ala.
IR.eg'aallsittoir
The function of a damper regulator is to check the
draft when the boiler pressure reaches a predetermined
limit. Having determined the amount of air required
to burn a certain kind of coal and the quantity that it
i< desired to burn per square foot of grate area per hour,
Pressure Controller
"Q
Damper
Weight-
^
Damper Regulator Electrically Controlled
it is desirable that the flow of air through the lire bed
be maintained as nearly con-taut a- possible. The damper
should remain shut only long enough to check the rise
in pressure and reopen when the pressure has decreased
one pound below the predetermined limit. If it requires
0.68 in. of draft to burn No. 1 buckwheat coal at SO lb.
per sq.ft. of grate area per hour, and the damper is ad-
justed to control the air supply to that amount, then the
regulator should open and close between the limits of
1-lh. rise and fall in steam pressure, and the fire will be
allowed to cool hut little before it is burning again at
the lull intensity. It will be found that under that close
regulation with natural draft a much more uniform and
higher average CO., can be maintained and the efficiency
of the boilers increased, with the resulting saving in coal.
The illustration shows an electrically controlled damper
regulator that I designed to meet conditions where the
( loses! possible regulation is expected. The results with
natural draft are nearly equal to those obtained by a
balanced draft system without the use of blowers, which
increased tin: cost of power required to operate such
system-.
IIexkv \V. (Jeare.
Xew York City.
In the editorial in Power of Feb. 9 on "Formulas
for Bumped Heads** you failed to mention several with
which engineers should be made familiar. Here are some :
Mind everybody's business but your own.
Always butt in where you are not wanted.
If your boss happens to be a large man and tells you
that you are not on your job, call him a liar.
Pick out a good huskv fireman and kick him in the
slats.
Fail to duck your nut when you pass under a low pipe
line.
Come home at 2 a.m.. stewed to the gills, and tell your
wife that you had trouble at the plant and had to work
overtime.
These few will no doubt direct a course of investigation
which will result in digging up many more "formulas
for bumped heads."
E. L. Aixe.
Reading, Penn.
&
Some years ago I had the opportunity of experimenting
in preparing boilers for a long period of idleness. The
steam generators consisted of three horizontal-tubular
boilers, 100-hp. each, and were in good condition. The
feed water being badly incrusting, a boiler compound
was used to prevent pitting and corrosion.
Before laying up the boilers they were cleaned inside
and out and a coat of red lead spread on all accessible
external parts. Boiler No. 1 received the following treat-
ment: The inside was dried and a box of quicklime was
put in to absorb any moisture remaining. Before closing,
a pan of charcoal was burned to consume the oxygen of
the air. The handhole plates were then replaced and
the boiler made practically air-tight. Boiler No. 2 was
filled with water ami 150 lb. of soda dissolved in it, which
i^ equal to 50 lb. to each 100 cu.ft. of water. All open-
ings were then tightly closed. Boiler No. 3 was com-
pletely filled with feed water, and all the air was allowed
to escape through a valve at the top. In each boiler was
hung a polished wrought-iron bar.
Nine months later I was called back to prepare the
plant for operation. On opening boiler No. 1, the iron
liar was found to be slightly rusted, hut the oxide was
easily rubbed off with the finger. The bar hung in No.
2 was as bright as the day it was put in. Boiler No. 3
was found to have lost about half its water in some way,
leaving the bar above the water line This liar was badly
518
TOWER
Vol. 41, No. 15
rusted, the corrosion having eaten into the metal g^ in.
My opinion is that the dry method is the best and cheap-
est, there being no danger of freezing in extreme cold,
and no water to leak out.
K. Hudson.
Spokane. Wash.
v
ReseaSaiagl a ISaM lEiragnira© V
The following shows what may be done in an out-of-
the-way place when there is a will to do it. The valve
and valve seat of a Ball engine. Fig. 1. being worn, the
valve was sent to the shop and overhauled, but the engine
could not be spared long enough to send the cylinder
away.
The tool shown in Fig. 2 was made to true the upper
seat after the lower one had been leveled and scraped.
T . . , _, Upper valve seat on
Two-piece balanced w^icn device illustrated
valve.. was usec/ . , - stez
\ Lower valve seat chipped,
filed and scraped
Fig. 1. Type of Valve Operated On
Tool
(Round]
\Stock J
Revolving
Tool Head
J Brass Friction Nut
l]| Lock Nut
l_ j Nut holding Tool Head
!»o ! d
Set-screw
for holding
tool ^
Base held to place by
forcing friction nut
against top seat
Fig. 2. Tool Used in Truing Valve Seat
It consists of a east-iron block A fur a base and a revolv-
ing tool head B. The cutting tool was set away from the
renter Ear enough to swing across the width of the face
of the seat. Four holes vvere bored to receive the small
bar used to rotate the tool head. The tool was set upon
the lower seat and the adjusting nuts set up against the
upper seat lightly, the tool was then adjusted to the de-
sired nit. ami the bead rotated with the bar in one hand,
while the base was held steady with the other. The ad-
justing nut required frequent changing at first, but as
the work progressed only slight adjustments were neces-
sary. A surface approximately 8x10 in. was gone over
in about five hours, taking a cut from almost nothing to
3/64 in. The tool cost $5, making a satisfactory job at a
low cost.
E. A. Jannet.
St. Joseph, Mo.
S3
Q^iclrl M,©p>aiiir ft© CcDinasinmllgitos'
We have three 1500-kw., GOO-volt, direct-current gen-
erators for operating a street-railway system. These rim
at 750 r.p.m., and the commutator bars are held in place
by three shrink rings which are separated from the bars
by mica insulation.
A short-circuit developed between two of the bars, and
Illustrating How Repair Was Made
investigation showed that it was directly under one of
the shrink rings. To save the time and expense re-
quired to take off the shrink ring, a TVin. hole was
bored between the two bars showing the short-circuit: it
being necessary to drill nearly the whole depth of the
shrink ring. After the short was cleared the hole was
filled with a composition of mica and shellac, and the
machine was put back in service after twelve hours' shut-
down and has since been operating and carrying full
load u i 1 limit difficulty.
J. B. Crane.
Duluth, Mum.
®.
A.atP Inlose aimd! IBtiacl&eft as
A.stnuna©2Ma IrHelsimett
To be able to remain calm when there is a serious
ammonia leak about the plant is a valuable asset to a
refrigerating engineer.
The following is an excellent example of the engineer
doing the right thing at the right time. He was operat-
ing an absorption plant when a serious break in the
ammonia end of the aqua pump occurred. Before he
could shut the valves the ammonia fumes had become so
strong that he was compelled to leave the room. The
engineer realized that the charge of ammonia would
be lost unless the valves were shut immediately. Reach-
ing in through a window he pulled the air hose loose
from the air hoist. He then put the end of the hose
into a three-gallon water bucket, and with the hose at
the back pulled the bucket down over his head, and with
his improvised helmet was able to get at the valves to
save the ammonia. The air. which was at a fairly high
pressure, blew the ammonia fumes from his face.
0. A. Robertson.
Atlanta. Ga.
April 13, 1915
P O W E E
519
nag a.
.Mr. Lent's criticism in the .Mar. 9 issue, of the writers
article on pumps in the Feb. 1) number, seems to be de-
voted largely to deploring the tatter's lack of knowledge
upon the subject rather than to imparting useful in-
formation to replace that which he discredits.
The suggestion that the priming of a centrifugal pump
should have been mentioned is a good one. The length
of the article, however, did not allow of a discussion of
many of the important details relating to the various
types mentioned, and this was omitted, with others
of a similar nature. Possihly a second reading will
bung out the fact that the matter of distance was not
the only factor noted regarding the selection of a pump
for a given set of conditions.
A deep-well pump having an efficiency over 80 per cent,
and no slip, is interesting as showing what can be done
through good design and careful adjustment, but is hard-
ly to be taken as current practice. The Deming Co., large
manufacturers of this type of pump, give average effi-
ciencies even lower than the ones criticized, while those
for triplex pumps are practically the same as given by
the writer.
Methods employed for increasing the flow of artesian
wells are discussed in detail by Professor Turneaure, in
•'Water Supply." Part I, American School of Correspon-
dence, and might be of interest to Mr. Lent. The use of
the air lift for increasing the flow of artesian wells has
been recommended to the writer by the consulting engi-
neer of a large concern making a specialty of sinking
wells and installing pumps of various kinds.
Gebhardt's "Steam Power Plant Engineering" gives
the efficiency of direct-acting steam pumps as varying
from 50 to 90 per cent., according to the conditions under
which they are operated, with an average of about G5 per
cent, for actual practice. The writer's estimate of 60
to 80 per cent, does not appear to be outside the usual
limits. The Lawrence .Machine Co. recommends efficien-
cies of 50 to 60 per cent, when estimating the power for
driving centrifugal pumps of the type used for circulating
hot water in heating systems, while tests of high-class
machines, as given in standard works on pumps and pub-
lished in the catalogs of the Worthington and De Laval
companies, show efficiencies running from 70 to 80 per
cent. The range of 60 to 80 per cent., as given in the ar-
ticle, does not seem unreasonable when compared with
average results.
Regarding the statement relating to the action of volute
and turbine pumps, Gebhardtfs "Steam Power Plant En-
gineering," pages 630-631, may throw some light on
the matter.
In brief, the writer has no desire to discredit the views
of Mr. Lent or enter into any controversy, but he wishes
to emphasize that the statements made in the original
article seem to be well supported by authorities of high
standing and to be based on average current practice.
Charles L. Hubbard.
Boston, Mass.
Charles L Hubbard's article, "Selecting a Pump for
General Service," in the Feb. 9 issue is of interest, and
may be modified and enlarged upon without limit. The
following may be of additional interest.
It may be worth while to note that the usual steam
consumption for this type of pump is more nearly 200 to
350 Mi. per developed horsepower per hour than mi to 160
lb. The latter would be difficult to obtain under idea!
conditions of tight steam valves and pistons working on
smooth, polished, well lubricated surfaces, the best
hydraulic piston packing, fitting snugly to the water-cyl-
inder barrel, and tight suction and discharge valves. Even
this extravagant use of steam is not a serious disadvantage
when the pump is installed under proper service condi-
tions, as the exhaust steam can often be used advanta-
geously.
Under normal operating conditions direct-acting steam
pumps should not have a slippage of more than 5 per
cent., and any pump having 15 to 30 per cent, should
receive prompt attention from the operating engineer.
A normal speed of 100 ft. per min. is conservative.
Boiler-feed pumps frequently operate at halt' this rate,
while general -service pumps operate satisfactorily at 50
per cent, excess speed. The piston speed of a pump has
little or no relation to its proper operation unless the
valve area is restricted. The important consideration is
the number of piston reversals, hence the number of
times the flow of water is interrupted. The higher the
speed the lower the steam consumption per indicated
horsepower per hour, due to the reduced cylinder con-
densation.
A single, or simplex, pump is one having a single steam
and water cylinder arranged along the same center line.
A duplex pump is two single pumps placed side by side,
the steam valves receiving their motions from the piston
rods of the opposite sides. Owing to its simplicity, posi-
tive operation and even rate of discharge, the duplex type
is often preferred, although the single pump has a slightly
lower steam consumption.
Power Pumps
The power pump has more universal application than
the steam pump, because of the extensive use of electricity
and the gas and oil engine, to which it is either belted or
directly connected. The belt drive is preferable, as it is
quieter, more flexible, and provides a safety, which may
prevent serious damage to the pump. It is frequently
objected to where the pump is to be automatically started
and stopped. In such cases, the belt should be selected
with care and the drive carefully laid out.
The belt should not be allowed to run slack or slip, as
this eventually results in its destruction, and interrupted
service. A proper-sized belt, cut from the best hide, thor-
oughly stretched, carefully made and rightly installed.
with an idler for maintaining a constant tension, is a most
satisfactory drive ami should operate for years. Where
an idler pulley is not desired or where there is much mois-
ture, a rubber belt will give more satisfactory service than
leather. If the space is limited, a close-belted idler drive
is to lie preferred to a gear drive, and especially is this
so in apartment houses ami office buildings, where the
noise of the gears may be transmitted through the piping
system.
The power pump is much used for elevator, domestic
and irrigation service, as it may he conveniently located
and long lines of steam pipes are eliminated. The dis-
charge is positive, hence a relief valve should always be
placed in the discharge line, close to the pump, to prevent
excessive pressure and damage to the pump.
In the larger sizes and where the plunger loads are rea-
sonably large, the efficiency is from 80 to 90 per cent.
520
POWER
Vol. 41, No. 15
A slippage of 15 to 20 per cent., as stated by Mr. Hub-
bard, is excessive; it should not be mure than 3 to 5 per
cent. Most power pumps, especially the vertical triplex,
are outside-packed ami the slippage past the plungers is
evident.
Power pumps are either horizontal or vertical ; the
larger sizes are usually horizontal. Both types are built
single, duplex, triplex or quintuplex. The vertical triplex
is the must popular high-grade power pump, because of its
moderate cost, smooth discharge and generally satisfac-
tory service.
Deep-Well Pumps
This class of pump performs the most severe kind of
work, and there are indeed few deep-well pumps which
render reliable service year in and year out. There is great
difficulty in maintaining the well rods, which frequently
reach five or six hundred feet to the water level below the
ground, and in some cases of oil wells, three or four thou-
sand feet below the surface. Because of their great length
and the large inertia stresses due to the rising and falling
column of water, the rods are frequently broken, and until
the wreckage can be removed and the rods renewed the
service is interrupted.
The vertical artesian steam engine is so cushioned that
rod troubles are slight on wells up to 200 ft. deep. The
power-well head has troubles all its own, especially on
deep wells. The difficulties have, however, been largely
eliminated by the triple-plunger barrel and well head,
known as the "Glendora" deep-well pump, manufactured
by the Deane Steam Pump Co. With this construction
the column of water is always moving upward. There is
no reversal of stress in the well rods, and the efficiency is
85 per cent, and more, as against 65 to 70 per cent, for
the single-acting power-well head.
Mr. Hubbard states that deep-well pump efficiencies are
40 to 50 per cent. This is true only of the centrifugal type.
There are installations where centrifugal deep-well pumps
give better initial efficiencies, which are maintained only
by frequent tuning up.
Centrifugal Pumps
Centrifugal pumps are most desirable for clear water
and low heads. Efficiencies of 60 to 80 per cent, are nor-
mal, but appear absurd if the slippage is as great as 20
to 6ii per cent., as given by Mr. Hubbard. The foregoing.
of course, assumes that the pumps are of good design and
construction, properly maintained and operating under
suitable conditions. It is evident that the discharge head
might be so great that there would be no discharge and
the slippage would then be 100 per cent. A slippage of
20 to 40 per cent, would be reasonable for a well designed
pump operating under the conditions for which it is
designed.
A peculiar characteristic of a centrifugal pump is that,
as the pressure on the discharge is increased above some
fixed pressure for a particular pump, the required driving
power is reduced, and. as the pressure is reduced the re-
quired driving power is increased. For this reason the
centrifugal type is not adapted to fluctuating conditions
of service.
Am Lifts
The air lift as a pump would be simple were it not
necessarily complicated with compressors and air-storage
tanks, which are more or less dangerous and in some
states must be regularly inspected by a properly author-
ized inspector. The efficiencies given by Mr. Hubbard are
misleading, as the net overall efficiency is generally be-
tween 20 and 30 per cent., with isolated cases of better
efficiency.
Hydraulic Ram
A hydraulic ram would hardly be considered as a pump
for general service, and it may be located only where the
supply of water is itself elevated.
Robert E. Newcomb,
Supt. Deane Steam Pump Co.
Holyoke, Mass.
A small vertical boiler on a locomotive crane at the
works of the Champion Fibre Co. at Canton, N. C, re-
quired a new set of flues and an upper flue sheet. Time
being the essence of the contract, a novel means was em-
ployed by the boiler maker. To avoid the necessity of
removing the firebox in order to get inside to hold the
"dolly'- on the head of the rivets while driving, a piece
Dolly-Bar and Hammer Used ox Repair Job
of 3-in. shafting, the right length to reach from the
center flue hole to the rivet heads, was prepared, hinged
and pinned to a lever put through the center flue opening
(which was bushed to prevent injury to the edge).
The new bead was fitted in place in the usual way and
the riveting process was carried on in the following
manner: The heated rivets were passed inside of the
boiler to a pair of long, specially made tongs operated,
through one of the tube holes in the lower head, by a
man stationed in the firebox. He in turn placed the
rivet in the proper hole. Then the end of the dolly-bar
was brought to bear on the rivet head as described and the
pneumatic riveter "turned loose" on the outer end. The
cost of the job and the time consumed were, of course,
materially less than they would have been if done in the
ordinary way.
H. Kilday.
Canton, X. c.
[We presume there were "good and sufficient" rea-
sons for not wishing to invert the heads and drive the riv-
ets from the outside. The rather unsightly appearance
of such a job is sometimes objectionable. — Editor.]
April 13, 1915 POWER 521
fpimiiiiiimmiuiiiiiiumn n inn mm inn mum ilimii iiiimiii imiiiiii mi iiiiiiiiiiiiiiiini i i mi i limn imiiiiiimimiiiiiiiinii mi minimum i iiiiiiiiiiiiiiimiiinniu nmmiiiiu mg
ImiqpuiiiiFiLes ©f Qeimers\Il Hunter estt
ilinjliiiiiuiiuuinnili iiiiiiniuiiiuuin mini mninnil mm i i mum i i mil mi mm u milium inn n iiimmuuiii uminuiiiuuimnmiiiiiii i I
Temperature for Pourinc Babbitt Metal — How can the
proper temperature for pouring babbitt metal be known?
F. I,.
When a yellowish tinge has formed on the surface, or if
a white-pine stick is heavily browned or slightly charred
when inserted in the molten metal, then the proper tem-
perature has been reached for pouring.
Disadvantage of Loir Boiler Settings — What is the dis-
advantage of low, as compared with high settings for return-
tubular boilers?
C. B. L.
Settings which are too low may be wasteful of fuel, for
when a boiler is set too close to the grates the flame is cooled
by coming in contact with the boiler surfaces before com-
bustion has been completed.
Calculation of Calorific Value of Coal — How is the calorific
value of coal determined from its analysis?
J. M. E.
The heat value of any coal may be calculated from its
ultimate analysis, with a probable error not exceeding 2 per
cent., by Dulong's formula,
Heat value in B.t.u. per lb. = 146C + 62o(H J + 40S
in which C, H, O and S are the respective percentages of
carbon, hydrogen, oxygen and sulphur present in the coal.
To Draw True Vacuum Line on Indicator Diagram — How
is the true vacuum line drawn on a steam-engine indicator
diagram?
M. G.
The line representing true vacuum "would be below the
atmospheric line a distance which represents atmospheric
pressure. Therefore, at sea level the true vacuum line is to
be drawn with a straightedge below the atmospheric line of
the diagram, and parallel to it, at a distance which, accord-
ing to the scale of the indicator spring, represents 14.7 lb.
per sq.in.
Objections to Sulphur in Coal — What are the objections
to the presence of sulphur in coal for steaming purposes?
C. R. S.
The calorific value of sulphur is less than ft that of carbon,
and its presence in fuel is objectionable because the gases
formed from its combustion attack the metal of the boiler,
causing rapid corrosion, especially in the presence of mois-
ture. Sulphur is also objectionable because it unites with
the ash of the coal to form a fusible slag, or clinker, which
chokes up grate bars, forming a solid mass having embedded
in it considerable quantities of unconsumed carbon.
Absolute Tec
perature?
eant by absolute tem-
G. R.
Since substances can be cooled below the zero point of the
ordinary thermometer, it does not represent the true zero
of temperature at which there is an entire absence of heat:
and while this has never been reached in cooling substances,
experiments indicate that it is 460 deg. below the zero of the
Fahrenheit scale. Hence, to change Fahrenheit degrees to
absolute temperatures add 460 to, or to change from absolute
to Fahrenheit degrees, subtract 460 from, the number of
degrees.
Obtaining Length of Open Belt — What is the rule for
finding the length required for an open belt?
R. B.
The best method is to measure the length directly by
passing a tape line around the pulleys. When this cannot
be done an approximate formula is
(R — r)*
Length = 2 L + 3.1416 (R + r) -\
L
in which all dimensions being in feet or inches,
L = The distance between centers of the pulleys;
R = Radius of larger pulley;
r = Radius of smaller pulley.
Lous of Draft in Flues and Elbows — What is the relative
loss of draft in round and square smoke flues and what al-
lowance should be made for elbows and lengths of flues?
W. C.
The retarding effect of a square flue is about % greater
than for a circular flue of the same area, and for brick
flues is about J greater than for steel flues. Short right-
angle turns reduce the force of draft about 0.05 in. for each
turn and a circular steel flue the same size as the stack
causes about 0.1 in. draft loss for each 100-ft. length of flue.
In average power plants it is usually practical to reduce
the loss of draft by providing a smoke flue with a cross-
sectional area about 20 per cent, greater than the cross-
sectional area of the stack.
Duty of Steam Pump — What is meant by the duty of a
steam pump?
H. N. M.
The duty of a steam pump is the number of foot-pounds
of useful work realized, or the equivalent number of pounds
of water lifted 1 ft. high, per 1,000,000 heat units furnished
by the boiler; i.e.,
Foot-pounds of work done X 1,000,000
Duty =
Total number of heat units consumed
The old unit of comparison was the number of foot-pounds
of work realized per 100 lb. of coal, and this was inexact, as
the amount of steam depended upon the quality of the coal
and the evaporative efficiency of the boilers. The modern
unit of comparison is not seriously at variance with the old
unit, as in good boiler practice 1 lb. of coal will yield at least
10,000 B.t.u. in generation of steam.
Loss of Heat from Steam Pipe — What would be the loss of
heat from an uncovered 6-in. steam pipe 80 ft. long, contain-
ing steam at 100 lb. gage pressure?
W. B.
Bare pipe will radiate approximately 3 B.t.u. per hour per
square foot of exposed surface per 1 deg. of difference in
temperature between the steam contained and the external
air. The temperature of steam at 100 lb. gage pressure being
338 deg. F., and assuming the temperature of air surrounding
the pipe to be 80 deg. F., then the loss of heat would be
(338 — 80) X 3 — 774 B.t.u.
per hour per square foot of exposed pipe surface, and as the
external diameter of 6-in. pipe is 6.625 in., the total pipe
area exposed would be
6.625
X 3.1416 X 80 = 138.75 ft.
and the loss of heat would amount to
138.75 X 774 = 107,392.5 B.t.u. per hour.
Equivalent Evaporation — With an average temperature of
feed water of 136 deg. F., 2900 tons (each 2240 lb.) of coal
were required to evaporate 38,000,000 lb. of water into steam
at an average gage pressure of 137 lb. per sq.in. What was
the equivalent evaporation from and at 212 deg. F. per pound
of coal? J. A. M.
The evaporation under the actual conditions was
38,000,000
= 5.S49 lb.
2900 X 2240
of water per pound of coal. The steam tables show that 1 lb.
of steam at 137 lb. gage, or about 137 + 15 = 152 lb. absolute,
contains 1193.6 B.t.u. above 32 deg. F., and as each pound of
the feed water contained 136 — 32 = 104 B.t.u., then for
conversion into steam at the stated pressure each pound of
feed water received
1193.6 — 104 = 10S9.6 B.t.u.
As the latent heat of evaporation of a pound of water at 212
deg. F. is 970.4 B.t.u., the factor of evaporation was
1089.6 -f- 970.4 = 1.1228
hence the actual evaporation was equivalent to an evapor-
ation of
5.849 X 1.122S = 6.567 lb. of water
from and at 212 deg. F., per pound of coal.
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
.v>->
P 0 W E R
Vol. 41, No. 15
timi
SYNOPSIS — An enumeration of the various tests
to determine tin qualities of an oil. Results ob-
tained are only approximate.
A brief description of a desirable lubricant is that its
viscosity should be the least possible which will allow it to
stay in place and do the work. Summarizing the commonly
desirable characteristics, they are:
1. The oil should possess cohesion.
2. It should possess the maximum possible adhesion.
3. It should be as far as possible unchangeable.
4. It should be commercially free from acid.
5. It should be pure, that is, it should be what it pur-
ports to be.
TYPES OF VISCOSIMETER
The first to be discussed is the viscosity test, which is
used to measure the internal friction of the oil, or, as an
engineer might put it, the shearing modulus. This test is
of value because a lubricant is really used to keep a shaft
or journal and its bearing apart. The journal really revolves
on a sheet of lubricant, an action which has been described
as revolving on the molecules of the lubricant. The ease with
which the molecules slide over one another therefore deter-
mines, to a certain extent, the friction loss in a bearing.
A fine example of the effect of the viscosity of lubricating
oil is furnished by an experience in a certain spinning mill.
This mill was operated with power derived from an engine
carrying about the maximum load of which it was capable.
The lubricant used on the spindles was changed to one which
was supposed to be better. It was then found that the en-
gine did not have power enough to drive the machinery in
the mill; as a matter of fact, it was unable to start the
machine in motion. Examination showed that the only
essential difference between the two lubricants was the pos-
session of higher viscosity by the new oil.
The measurement of viscosity of lubricating oils is in a
certain sense unsatisfactory, because the results obtained
with the different instruments which are available for mak-
ing this test do not agree among themselves. It is there-
fore customary to state the instrument which was used in
determining any quoted viscosity.
One of the most commonly used viscosimeters is the
Saybolt instrument. This is of the pipette type, having a tall
pipette of rather small diameter immersed in a jacket which
may be used for maintaining any desired temperature dur-
ing the test. The test is made by filling the pipette to a cer-
tain point and noting the time of efflux, in seconds, which
is taken as the measure of the viscosity of the oil tested. Or
the so called specific viscosity may be determined by dividing
the time required for the efflux of the oil by the time required
for the efflux of the corresponding volume of water. The
Saybolt instrument was developed by the Standard Oil Co.
and was used as a standard for many years, and is today.
The instrument most commonly used in Germany, and now
coming into rapid use in this country by both the Government
and individuals, is known as the Engler viscosimeter. This
differs from the Saybolt principally in using a shorter pipette
of larger diameter. It is used in the same way, but the specific
viscosities as determined by the two instruments do not agree.
None of the commercial viscosimeters really measure the
viscosity, becaues it can be shown that the tube through which
a jet is discharged must have a length of from 175 to 200 times
the diameter to give a true measure of viscosity. Any of the
commercial instruments can, however, be standardized by
measuring the times of efflux of standard solutions of cane
sugar or of glycerin. By such means the readings of these
instruments can be interpreted in terms of absolute viscosity
in dynes.
Numerous viscosimeters made of glass have been tried,
but unfortunately no two glass instruments can be made ex-
actly alike except at prohibitive expense. For this reason,
the glass pipette once used as a standard by the Pennsylvania
R.R. was abandoned. It should, however, be noted that a
glass pipette, calibrated with glycerin as above described,
can be used.
The viscosimeters just mentioned are all of the efflux
variety, but there are numerous other forms available, and
some of them are particularly well adapted for testing the
viscosity of certain commercial products other than oils. For
•Abstract of paper read by Prof. A. H. Gill before the
Detroit Engineering Society, Mar. 19, 1915.
icaftiEng Oils*
instance, the retarding effect exerted on a paddle revolved in
a viscous liquid may be used as a measure of the viscosity
and is so used with varnishes, glue and paste. Another form
consists of a cylinder suspended from a torsion wire. The
retarding effect upon this cylinder when swinging back to
normal position after a displacement can be used as a meas-
ure of viscosity.
It should be particularly noted that the viscosity varies
rapidly with the temperature. It is therefore necessary to
state the temperature at which any determination was made.
FRICTION TEST
There is really no satisfactory test of the adhesive quality
of a lubricant. It is commonly supposed to be determined
by a friction test. This is made by measuring the frictional
resistance offered to the rotation of a standard journal in
a standard bearing when lubricated with the oil in question.
The results obtained depend partly upon the viscosity of the
lubricant and partly upon its adhesion. Modern research
shows that viscosity tests show about as much as do friction
tests, but this is not necessarily so, and must not be assumed
to be universally applicable.
GUMMING TEST
A third test, and one which is of great importance, is
known as the gumming test. This is particularly applicable
to petroleum oils and is used to indicate the extent to which
the oil has been refined. It serves indirectly to indicate the
extent to which the oil may be expected to change due to
oxidation when in use. Numerous opportunities have been
offered to check the results obtained with this test and re-
sults obtained in practice with the same oils, and all of this
experience tends to show the great value of the gumming
test.
This test is made by putting a small quantity of the oil
to be tested in a small glass vessel, such as a cordial glass,
and then mixing with it an equal quantity of nitrosulphuric
acid. A properly refined oil will show little, if any, change,
but a poorly refined oil will be indicated by the separation
of large quantities of material of dark color. This color is
due to the oxidation of the tarry matter contained in the
lubricant. Experience has shown that oils containing large
percentages of tar absorb the most oxygen, that is, they
are mildly drying oils.
The results obtained by the gumming test agree well
with carbon-residue tests made by distilling to dryness in
a glass or a fused quartz flask. The carbon-residue test
has been found of great assistance in choosing a satisfactory
cylinder lubricant for gas engines, as a large amount of
carbon means trouble in the engine cylinder. The lowest
carbon content mentioned by the author was 0.11 p.;r cent.
The oil giving this test showed no tarry matter when tested
with nitrosulphuric acid. In general, a gas-engine oil
should not contain more than 0.5 per cent, carbon as deter-
mined by the carbon-residue test.
FLASH, FIRE AND EVAPORATION TESTS
When an oil has been found to have satisfactory viscosity
and has given satisfactory results in a gumming test, it
must next be checked for safety, that is, the flash and fire
test must be made. The amount of volatile matter given off
at the temperature at which the lubricant is to be used is
often of great importance. A case is on record in which
a serious mill fire was spread by vapors given off by the
lubricant used in the various bearings. The oil used in this
mill gave off 25 per cent, of volatile material when raised to
145 deg. F.
It is advisable to include an evaporation test with the
flash test of lubricants. The evaporation test is made by
exposing about 0.2 gram of oil at a proper temperature and
determining the loss by weight in a given time.
The flash test is made by heating the oil slowly in a vessel
surrounded by a proper bath and determining the lowest
temperature at which a flame passed over the surface will
ignite the vapors which are given off.
FREE ACID TEST
It is generally conceded that lubricants should be prac-
tically free from acid, and the so-called free acid test is made
to determine the extent of acid content. The mineral oils are
agitated with sulphuric acid during the refining process for
the purpose of removing tarry materials, and this acid must
be practically all removed from the oil before it is put on
the market. Oils may become contaminated with acid from
another source as well: namely, the animal or vegetable oils
which are occasionally mixed with them for the purpose of
April 13, 1915
P 0 W E R
523
modifying their characteristics. A content of 0.3 per cent,
of acid is generally considered the maximum allowable.
SPECIFIC GRAVITY
It is often desirable to determine the character of the
raw material from which a given lubricant was made. This
can be done in the case of oils refined from petroleum by
means of the specific-gravity test. Experience has shown
that lubricants made from petroleum with an asphaltic base
run from 7 to 10 deg. Baume heavier than similar lubricants
made from petroleum with a paraffin base.
In examining oils, it is well to bear in mind that the
viscosity is easily increased by the use of a material known
as oil pulp or oil thickener. This is really oleate of alumina,
and while it brings up the viscosity, it does not give the
greasiness expected when that particular viscosity was
specified. At ordinary temperatures, a small quantity of this
material will greatly raise the viscosity.
COLD TEST
There is another test, known as the cold test, which is of
value in some cases. If an oil is to lubricate a bearing, it
must be fluid enough at the temperature of use to readily
flow into that bearing. Many ruined bearings and some fires
have resulted from the use of an oil which became too viscous
to flow under the conditions of use. For such /easons. it is
customary to chill samples of oil and to determine the tem-
peratures at which they become too thick to flow readily.
IODINE TEST
Tests other than those already described are often made
on animal and vegetable oils. They are generally made for
the purpose of determining whether the oil under test is
what it is supposed to be. It is a simple matter to mix dif-
ferent animal and vegetable oils in such a way that they
will give a product capable of passing any one or possibly
two given tests, but it is impossible to make such a mixture
successfully pass all of the tests w'hich would be passed by
the pure oil for which the mixture is to serve as a substi-
tute.
The chemist is often at a great disadvantage in testing such
mixtures, because there are no exact specific tests for some
of the animal and vegetable oils. The presence of some can
be determined absolutely, but unfortunately, this is not true
of all.
The iodine test, by which is meant the determination of
percentage of iodine absorbed by the oil under set condi-
tions, has long been used to indicate the character of vege-
table and animal oils present in a sample. At one time it
was believed that the so-called iodine number was a con-
stant for any one oil and that this test was therefore per-
fect. It is now known that this is not true, the iodine num-
ber varying with the condition of the material from which
the oil was made.
It is a simple matter to determine the presence of petro-
leum oils in a mixture of oils with animal or vegetable ori-
gin. This is done by saponification, which serves to separate
the petroleum oil, which does not saponify, from the others
which do.
MAUMENfi TEST
There is a comparatively new test, known as the Maumene
test, which gives results comparable with those obtained
with the iodine test, but is much simpler and therefore more
readily performed by the average individual. For this test,
50 grams of oil and 10 c.c. of sulphuric acid are placed in a
beaker and slowly stirred with a thermometer. The maximum
temperature rise which occurs is noted and used as an indi-
cation of the character of the oil.
TESTS ONLY APPROXIMATE
It should be appreciated by the practical man that the
tests of lubricating oils give only approximate results. Thus
any one viscosimeter as ordinarily made will give consistent
results on the same material at the same temperature, but
different instruments of the same type and apparently ex-
actly alike will give results on the same material which
vary several per cent. Similarly, large errors are often ob-
tained when using friction machines. With tests otherwise
properly conducted, it appears that the absorption of oil by
the metal of the journal and bearing may be sufficient to
cause appreciable errors. Tests have shown that it may take
several hours to eliminate the effects of the last oil tested so
as to get correct results with a given sample.
No rigid directions can be given for the choice of oils
lor given purposes. It is best to try various lubricants
which can be purchased for any given lubricating problem
until one is found which gives satisfactory results. This
should then be completely tested and the results of the test
should be used in writing specifications on the basis of
which bids are to be asked. When the problem is handled
in this way, the different prices asked for lubricants which
will meet the same specifications will often be found most
remarkable.
Ws*©ufljg»lhiil H^OKa siimdl SfteeH Tribes*
By J. <;. Stbwaet
When the British Engineering Standards Committee con-
sidered the question of screw threads for pipes they compared
the merits of two well known forms of thread, viz., the Whit-
worth or British standard bolt thread, the Sellers, or U. S. A.
standard, and another, not so well known — the Briggs Amer-
ican standard pipe thread. The committee decided by a ma-
jority (of which the writer was not a party) to accept the
Whitworth thread, principally because the tools to make it
were already in the hands of every engineer and plumber in
this country, but also because taps and dies made to this
form have little tendency to change by wear, which is not
the case with the American standard forms of bolt and pipe
joints.
However, any pipe joint, in order to be petroleum tight
under high pressure (many oil lines work at 1000 lb. per
sq.in.) must be of very special and accurate construction,
and for this class of work the Briggs thread has alone proved
satisfactory. It will be noticed that the crest of the thread is
very sharp, much more so than the contour of the root. One
result of this is that a difficulty occurs in maintaining the
screwing tools to their correct shape. This is minimized by
forming the tools to the correct profile by a single cutting
tool which leaves the sharp crests on the master tap. As
there is a considerable amount of cutting surface to be worn
away on the master tap, the sharp edges stand up to their
work for some time without losing appreciably the sharpness
of the thread.
The difference in the power required to draw up a coupler
with the Briggs thread, as compared with one with the Whit-
worth, is marked, particularly as such threads are made on a
cone with a taper of ^ in. per inch. With the Whitworth
thread little movement can be given to the coupler with a
heavy pipe wrench, after it has been drawn up by hand, as
compared with that which can be obtained in a Briggs thread
joint. There is little doubt that Briggs himself, in putting it
forward in his paper which was read in America in 1886, Cell
into confusion. His description of his proposed thread, which
was subsequently adopted as the American standard pipe
thread, is as follows: "The thread employed has an angle of
60 deg.; it is rounded off top and bottom, so that the height
or depth of the thread, instead of being exactly equal to the
pitch, is only four-fifths of the pitch." But, having an angle
of 60 deg., the depth could not be equal to the pitch. There
can be no doubt that what he meant to say instead was "the
depth appropriate to the pitch." This depth measures 0.SG6
and as the depth was to be 0.8 the amount to be taken off
the sharp edge or crest was 0.066, as against 0.17 on the Whit-
worth standard.
The question arises, Can a joint be made in this manner —
i.e., with the Briggs thread — be undone, and remade if oc-
casion arises? The answer is that it depends upon the treat-
ment given when the joint is first made. If the couplings
are driven very hard upon the screwed ends of the pipes it
may be found impossible to disengage without injury to the
thread and again remake the joint. But if the joints are
screwed up with proper care and with a liberal use of thick
viscous oil, these joints with this form of thread can be un-
made and remade five times at the least computation.
Many engineers are under the impression that a coarse
thread is stronger than a fine one, but that the converse is the
case may be readily demonstrated. Take a pipe or bolt, and
screw it at one end with a fine thread and with a coarse
thread at the other, with nuts to correspond; place a spiral
spring between them and draw up until one of the threads
strips. This will invariably be found to be the coarse thread.
An important item in drawing up a specification for steel
pipes is the method of bending them to the required pattern.
There are two ways in which a steel pipe may be bent.
The straight length of pipe may be set on a table be-
tween supporting dogs and bent by drawing the free end
of the pipe against the dogs. By this method the pipe is con-
stantly under the observation of a skilled operator, who is
careful to arrest any local drawing of the metal on the out-
side radius, by causing the pipe to thicken on the inside radius
rather than to reduce on the outside. The other way is to
bend the pipe between a pair of dies, each forming a half-mold
of the bend to be made. Curiously enough, some engineers
seem to be under the impression that the correct way to
•Abstracted from a paper read before the Institution of
Engineers and Shipbuilders in Scotland, Feb. 16, 1915.
524
POWER
Vol. 41, No. 15
form a bend is by dies, whereas the two methods will not
stand comparison.
When a piece of tube is bent into a curve, first, one side
of the tube must stretch or become extended in length;
secondly, the opposite side must, in a lesser degree, become
shortened; and, thirdly, the cross-section of the tube must
become an ellipse. Condition No. 2 is no disadvantage, and
condition No. 3 can in most cases hardly matter, as the cross-
sectional area is only slightly diminished. The consequences
of No. 1 may seriously injure the bend, the result being a
reduction of the thickness of the wall, even to the extent of
rupture; this does actually take place frequently when the
radius of the bend has a small ratio to that of the cross-sec-
tion of the tube.
It follows that in making a bend it is desirable to control
and relieve the stretching at the expense of the other two con-
ditions. The only way of exercising this control is for an
expert workman to watch the action and cool the part where
he can detect thinning. Along the outside of the bend it will
be more prevalent at one point than at others, and wherever
it is apparent it will accentuate itself as the metal gets more
attenuated and weaker. An experienced bender will stop the
bending and cool the yielding part by a water jet before
resuming. He may require to cool many parts many times
before he completes the operation of forming his bend. This
manipulation is quite impossible if the forming is done be-
tween a pair of dies.
No doubt, bending pipes in dies is a more expeditious proc-
ess, suited to unskilled labor, and therefore cheaper, but
the quality of the work is altogether inferior. Bending of
pipes in dies should never be employed or sanctioned for any-
thing but the sizes of pipes of, say 2-in. bore and under. To
confirm this opinion one has only to drill holes in the back of
two pipes bent by these two processes, when the difference in
thickness of the metal will at once establish the superiority
of the first mentioned method.
I have purposely avoided reference to the controversial
subject of the relative merits of steel and cast iron for pipes.
Some years ago, "when steel pipes were introduced for the
gas and water supply of our Colonial possessions and other
markets far removed from the manufacturing centers, these
light lap-welded tubes proved of inestimable value in develop-
ing new towns and colonies, which, had it not been for their
low cost and the low freight on them, would in many cases
have been without water supply to the present day. With
very few exceptions these pipes have given every satisfaction,
recent reports from all sides showing that they are practi-
cally as free from corrosion as when laid. This being so,
there is a natural disinclination to pay the extra price and
freight charges of the thicker hot-rolled weldless pipe.
As regards its application to water and gas pipes, the
total value of steel pipes for that purpose manufactured last
year in this country was about £7,000,000, or three times
as much as it was 15 years ago. The steel pipe maker, there-
fore, has certainly nothing to complain about. I believe that
during the same period, the production of cast-iron pipes
has remained about stationary, but I have no definite statis-
tics on this point.
A few representative cases may be cited as illustrating
that the rapid transition from cast iron to steel indicated by
the above figures is well warranted. For the water supply of
Perth, Western Australia, a cast-iron pipe 12 in. diameter
was laid about twenty-five years ago, and this was supple-
mented 17 years ago by a steel pipe 21 in. diameter. The
former has been twice scraped to remove the internal nodular
incrustation due to rust, some of these nodules being found to
be from 2 to 3 in. thick. On the other hand, the steel pipe, on
recent inspection, was found to be practically free from cor-
rosion. This case is remarkable from the fact that the water
is from the same source and practically identical with that
pumped through the celebrated 350-mile line of 30-in. steel
pipe for the water supply of Coolgardie, the internal corrosion
of which in places (principally due to portions of this pipe
line being allowed to run only half full, that is, between wind
and water) has led to a good deal of extravagant comparison
of the relative corrosion-resisting qualities of steel and cast
iron coupled with the assertion that the laying of this main
in steel was a false economy. The real facts of the case are
that the local authorities knew full well from the above-cited
experience in the Perth water supply that any trouble ex-
perienced with this main in steel would certainly have been
very much worse in cast iron.
Sixteen years ago the town of Bradford laid about 15
miles of 36-in. steel pipes. At that time there was a difficulty
in supplying bent pipes of this size, and the bends in the line
were therefore furnished in cast iron. A recent landslide at
one of these bends dislodged the leaded socket between the
straight steel pipe and the cast-iron bend, when it was found
that the surface of the cast-iron pipe was heavily incrusted,
owing to corrosion, thus seriously reducing the capacity of the
pipe, but the steel pipe was found to be in almost the same
condition as when laid, with the glossy surface of the Angus
Smith's solution practically intact as originally applied 16
years ago.
Twenty-two years ago Vancouver actually risked its wa-
ter supply with a 16-in. steel main only Va in. thick. Inspec-
tion of this main last year demonstrated that the estimate
of steel was not exaggerated, this very thin pipe being so
little affected by corrosion that the engineer estimated its
life to be worth at least another twenty-five years.
Thirty-three years ago the Kimberley Water Co., South
Africa, laid down a wrought-iron water-supply main 14-in.
and lS-in. diam., and % in. thick, of which the present man-
ager stated early this year: "With the exception of the por-
tion which runs through a salt marsh, and which was re-
placed some three years ago, the pipe line is in as good a
condition as when it was put down, and we do not anticipate
any trouble for at least another twenty-five years."
I have selected the above cases for citation, because they
represent pioneer work in four continents, and have led to
the very general adoption of steel pipes throughout Austral-
asia, Canada and South Africa, while the favorable expe-
rience of Bradford is now leading to the adoption of steel for
the water-supply mains of some of the largest industrial
centers in the country.
Years ago steel established itself as the material for high-
pressure steam-boiler feed, and all other high-pressure ser-
vice. In addition to the large number of steel, steam, feed,
boiler and general service tubes to be found on every modern
steamship (the boilers of the "Lusitania," "Mauretania" and
"Aquitania" alone contain 100,000 fire tubes), the saving in
weight effected by tubular construction has led to its adop-
tion on board ship for many purposes where other sections
and materials were formerly used.
Upon the general question of whether the experience of the
last few years would warrant the conclusion that the weldless
processes of tube making have now been developed to the
stage that they will, in the immediate future, in competition
with the welded tube, emerge triumphant, and that after all
the difficulties which for so many years have accompanied
these efforts continuously, I can only say this: In Germany,
where the weldless process has been most sedulously pursued,
the older methods of making tubes have not been developed
and improved in any degree approaching to the way in which
these older systems have been advanced by the Americans,
and in this country.
I have had many opportunities of seeing tube works in
Germany anil in the United States, and I am convinced of
this — that if the Germans had devoted as much labor of
mind and as much of money to the improvement of their weld-
ing plants as they have upon experiments on weldless proc-
esses, their competition would have been much more se-
verely felt here.
To summarize, the question is this: Can we produce by
the old-established, known method of making tubes a tube
as reliable as one made by the weldless process, and produce
it so as to be able to sell it at the same price? In this country
we can, and in America it is still possible. Commercially, the
two processes have nowhere met each other on equal ground.
There has also existed, very generally, a theoretic prejudice
in favor of the word "weldless," which has proved strong. In
Germany the weldless process is universal. In this country
and in the United States it is almost non-existent. Of course
we all know how often we have been told that the Germans
are beating us in everything, and how miserably incompetent
and antiquated in their methods our manufacturers are, but
we do not often hear the Americans branded as prejudiced
fools, unable to take care of their own interests. The ques-
tion is sometimes put thus: Is a tube any better for having a
weld? No one can pretend that it is, and when a weldless
tube can be produced of as reliable material and at about the
same cost as a welded tube, the days of the latter will be
numbered. That that day has not yet arrived is manifest, but
that it is always growing nearer is certain.
A. Yesis*"® IBoaEeip EDxqpIl©§n©E&§
The annual report of the Marine Department of the Board
of Trade upon the working of the Boiler Explosions Acts dur-
ing the year ending June 30, 1914, is now before us.
The number of explosions, 6S, and the number of lives
lost thereby, 22, are both below the average, but the number
of people injured, 74, is above the average. This is an exact
reversal of the state of affairs set out in the immediately
preceding report. Twenty-eight of the "boiler" explosions re-
ported upon resulted neither in loss of life nor in injury to
limb. The 96 casualties are thus attributable to 40 explosions.
The report is distinguished by the record of an unusually dis-
astrous explosion. On Aug. 26, 1913, a Beesley boiler, 22 years
April 13, 1915
P 0 W B R
525
..1.1, failed at the works of Walter Scott. Limit.-. 1. Hunslet,
Leeds, killing- 9 men and injuring IS. Investigation showed
that the center Hue tub.- had become worn out anil that its
first ting had collapse. 1 for its full length anil hail fractured
circumferentially. The insurance company, its assistant engi-
neer anil one of its inspectors were found to blame, and had
In pay costs totaling £600.
Twenty-nine of the explosions occurred to "boilers" which
wen- under the inspection of public bodies, but in 14 of these
cases the explosions were not due to material defects, and
therefore presumably could not have been guarded against
SBJGI
Tfce Xmiiinl Dinners of The Atlantic City Association
\. A. s. 1-;. are always a success in point of attendance and
speakers. The latest, given Mar. 20, was in keeping with all
previous ones. The guests of the evening were Col. Lewis
T. Bryant, Commissioner of Labor for Xew Jersey; George
Atlantic City X. A. S. E. ind Guests at Dinner
by inspection. Of the causes of the explosions, deterioration
or corrosion is most prominent, with 20 cases. Defective de-
sign or undue working pressure was responsible for 19, de-
fective workmanship, material or construction for 12, ignor-
ance or neglect of attendants for 9, and water hammer and
miscellaneous causes for 4 each. As for the types of boilers
which exploded, the horizontal multitubular was the greatest
offender with 13 cases. Vertical boilers came next with 7.
Tubes in steam ovens were responsible for 5. locomotive boil-
ers fur 4, while Lancashire. Cornish and other flue boilers re-
sulted in 3 and water-tube boilers in 2 explosions. Steam
pipes, stop-valve chests, etc., are classed as boilers in the acts,
and these are debited with 11 explosions. There are three
cases of pipes failing by fatigue caused by vibration. In one
case it was a cast-iron feed-water pipe, 21 years old. In
the two others the parts which failed were the main steam
pipes, one being sixteen months old and the other but two
months old. There are two cases of failure by fatigue caused
by expansion and contraction. In one a cast-iron steam pipe
28 years old was concerned, and in the other the front end
plate of a single-ende.' marine boiler B% years old was the
part at fault.- - 'The Engineer, ' London.
R. Starrs, of the Paterson, N. J., Board of Education; and A.
L. Case, of the Engineers and Firemen's License Bureau.
Other representative X. A. S. E. men and city officials were
present.
Detroit thief Engineers Dine — The second annual banquet
of the Chief Engineers' Club of Detroit, Mich., was held at
the Hotel St. Clair, Mar. 13, 191."..
This club, which has been in existence only three years,
is composed solely of chief engineers, and to be eligible to
membership one must occupy the position of chief engineer
in some steam plant. At the first annual banquet there were
42 present. This year S6 attended.
Immediately following the banquet there was a vaudeville
entertainment given by stars from some of the leading De-
troit theaters. The affair was under the direction of the
entertainment committee, J. H. Roberts, chairman.
Following is a copy of the menu card:
BILL OF MATERIAL
Exciter
Bleached Fiber I
Center Punches
Feed Water Agitators
Di fruit Chief Engineers' Club Dinner
526
POWER
Vol. 41, No. 15
Aggressor Carbon Brushes
Electrified Voltage
Aeroplanes
Gas Producers Aggregate
Silencer Circuit Breakers
Cement Pats
Refrigerator Assorted Gaskets
Treated Feed Water Fuel Testers
The executive committee for 1915 is as follows: Past-presi-
dent. Charles Mery: president, John Gretzinger; vice-presi-
dent. Alex Warner; secretary, H. C. Hayes; financial secre-
tary, Edward Kahl; treasurer, Alex Kothe; marshal, F. J.
Linck; assistant marshal, J. P. Field; entertainment commit-
t< . . J H. Roberts.
©Ihl© Adl©p>&s tlhe A. S.
The following "Special Notice" has been issued by the
chairman of the Ohio Board of Boiler Rules:
The Ohio Board of Boiler Rules at their meeting on Mar.
25, 1915, adopted the following resolution:
Until further notice, an Inspector holding a Certificate of
Competency and a Commission authorizing him to inspect
steam or hot-water boilers which are to be installed within
the State of Ohio, is hereby authorized to inspect during con-
struction and on completion stamp "oHIt> ST1 >" with Serial
Number any boiler constructed in accordance with Rules
formulated by the Boiler Code Committee as submitted to
the Council of the American Society of Mechanical Engineers
on February 13. 1915.
OHIO BOARD OF BOILER RULES,
H. V. NEFF, Chairman.
Mar. 29, 1915.
H@w Orfesiias ILaM.©iy ft© Hwe
Muasaicapsil Plsuraft
That the City of New Orleans will have a municipal light-
ing plant, involving an ultimate outlay of from five to six
million dollars, became apparent Mar. 15, when it was
announced that engineers sent by George F. Bishop, of
Cleveland, to make a survey of the proposition had com-
pleted their work and would soon make a report. There has
been organized agitation for a municipally owned plant in
the Southern city for many months and the New Orleans
Railway & Light Co., which is at present supplying electrical
energy for the city and private consumers, apparently isn't
so powerful a factor in the city and state affairs as it used
to be. The present street-lighting contract with the company
expires Sept. 30 but, according to Commissioner E. E. Lafaye,
whose department would have jurisdiction over the munici-
pally owned plant, it will not be necessary to execute a
new contract on that date or to make other arrangements,
as the contract may be extended so as to give sufficient time
for the construction of the municipal plant should that be
decided upon.
Arthur D. Little, Inc., chemists and engineers, of Boston,
are establishing an office in the Chemists' Building, 50 E.
31st St., New York.
Harry B. Aller now has charge of the Chicago territory of
the Ohio Injector Co. He will handle its complete line of
stationary power-plant equipment.
The Southwark Foundry & Machine Co.. Philadelphia,
Penn., is now actively engaged in the manufacture of hydraulic
and steam hydraulic presses and has a considerable volume
of this work in hand at the present time.
A correction — The advertisement of the Girtanner-Daviess
Engr. & Contr. Co., St. Louis, Mo., in the Mar. 16 issue read
"Sixteen installations since Jan. 1, 1915." This should have
read "Twenty-two installations since Jan. 1. 1915."
G. L. Simonds & Co., 500 Gaff Bldg., Chicago, 111., sales
department of the Vulcan Soot Cleaner Co., has been awarded
the contract for Is Vulcan soot cleaners to be applied to
IS Keeler boilers to be furnished for the Illinois State Board
of Administration.
A souvenir card being sent out by Yarnall-Waring Co.,
Chestnut Hill, Philadelphia, is a moving picture of the
Simplex seatless blow-off valve. It is really a valve model
and shows the construction and operation of the valve in
detail. Sent on request.
The Hoppes Manufacturing Co., of Springfield, Ohio, re-
cently made a sale of two 1,000,000 lb. per hr. Hoppes V-notch
recording meters to the West Penn Traction Co., Pittsburgh,
Penn. This is believed to be the largest installation of
feed water metering equipment in the world and will be
operated in connection with Hoppes feed water heaters.
The Lagonda Manufacturing Co., Springfield, Ohio, has just
published a booklet entitled, "Lagonda Boiler Room Special-
ties ." This booklet describes and illustrates the several types
of Lagonda boiler tube cleaners with latest improvements
and boiler quick repair tools. It also covers the Lagonda
automatic cut-off valve and multiple strainers. Copy may
be had on request.
The American Pulley Co.. of Philadelphia, Penn., manu-
facturer of the celebrated "American" wrought-steel split
pulley, has just completed arrangements for the opening of
its own store at 119 Jackson St., Seattle, Wash., where it
will carry a large and complete stock of pulleys for the
accommodation of dealers in the Northwest. Archie Chan-
dler, of Seattle, will represent the company in the distri-
bution of its product among dealers on the Pacific Coast.
The Buffalo Forge Co., Buffalo. N. Y.. has recently re-
ceived contracts for heating and ventilating apparatus for
the following public buildings: Private Ward Hospital,
Wilkes-Barre, Penn.; Southwark Public School, Philadelphia.
Penn.: Merchants National Bank, Richmond. Ya.; Union High
School, Alhambra, Calif.; High School, Compton, Calif.; El
Paso Telephone Co., El Paso, Tex.; public school. Garden
City, S. D.: Concordia Club. San Francisco, Calif.; Blooms-
burg church, Bloomsburg, Penn.
Practically all the sizes and types of Edison Mazda multiple
lamps are affected by reductions in list prices that were put
into effect Apr. 1, by the Edison Lamp Works of General
Electric Co. On the regular straight side and round bulb
lamps, from the 10-watt to the 250-watt sizes, also on sign
lamps, stereopticon lamps, etc., the reductions range from
3 to 20c. per lamp, according to the size.
On the gas-fiiled, multiple lamp of 100- to 1000-watt sizes,
the reductions range from 50c. to $1 per lamp, the average
reductions being between 20 and 25 per cent.
On Jan. 1, Lee H. Parker became president of the Spray
Engineering Co., 93 Federal St., Boston, Mass., maker of
Spray cooling equipment and air washers. Mr. Parker's ex-
perience in the engineering field has been unusually broad,
he having severed a connection of 10 years with the Stone &
Webster Co. to assume his new duties. Previous to this con-
nection Mr. Parker had been for six years with the General
Electric Co. and had also for some time represented large
English engineering interests in South America. Mr. Parker
was graduated from Cornell University in 1SS9 with the
degree of M. E.
For the territory comprised by Kansas, Nebraska, south-
ern part of Iowa and western part of Missouri, the Mcintosh
& Seymour Corporation, of Auburn, N. Y., has appointed as
its agent Stanton A. Hadley, 621 Delaware St., Kansas City,
Mo. Mr. Hadley is interested in the machinery-supply busi-
ness of Hadley-Hudson Co., Kansas City, but in the future
wil devote his whole time to the sale of Mcintosh & Seymour
Diesel type engines and steam engines and Gould pumps.
Previously district manager for the Griscom-Russel Co., of
New York, Mr. Hadley was prior thereto contractor, machinery
salesman, erecting man and earlier with the A., T. & S. F. Ry.
The Manati Sugar Co., in the Province of Oriente, Cuba,
with offices in New York City, has recently placed an order
with the Westinghouse Electric & Manufacturing Co., East
Pittsburgh, Penn., for electric motors to drive all of it .-.
machinery in its new mill with the exception of the engine-
driven rolls. This order covers a total of 32 alternating-
current motors, having a total capacity of 1042 hp. All of
the auxiliaries in this next extension of the Manati Sugar
Co. will be motor driven, these auxiliaries including cane
and bagasse conveyors, centrifugal pumps, crystalizers, agi-
tators, etc. All of the new material will be in operation for
the 1915-1916 grinding, and the electrical equipment will be
delivered in time for this operation.
STATEMENT OF THE OWNERSHIP. MANAGEMENT,
CIRCULATION, ETC., APR. 1. 1915.
of Power, published weekly at New York, N. Y., required by
the Act of August 24, 1912.
Editor, Fred R. Low, 10th Ave. at 36th St., New York, N. Y.
Managing Editor, Henry R. Cobleigh, 10th Ave. at 36th St.,
New York. N. Y.
Business Manager, William Buxman, 10th Ave. at 36th St.,
New York. N. Y
Publisher, Hill Publishing Company. 10th Ave. at 36th St..
N. w York. N. Y.
Owner, Hill Publishing Company, 10th Ave. at 36th St., New
York, N Y.
Owners of \',\ or more of Stock Issued.
John A. Hill. 10th Ave. at 36th St., New York, X. Y.
Fred R. Low. 10th Ave. at 36th St., New York, X Y
John McGhie, 10th Ave. at 36th St.. -New York, N. Y.
Fred S. Weatherbv, 1600 Beacon St., Brookline, Mass.
Frederick A. Hals'ev, 356 W. 120th St., New York, N. Y.
G. Eugene Sly, 50 Union Sq., New York, N Y.
Frederick W. Gross. 215 E. 11th St., Erie, Pa.
Alfred E. Kornfeld, 10th Ave. at 36th St.. New York. N Y.
Emma B. Hill. 80 Munn Ave., East Orange. N J.
The balance of the stock issued (less than 1', each) is
owned by 71 employees, 4 ex-employees, and 14 others who
are wives, daughters or relatives of employees.
Known bondholders, mortgagees, and other security holders
holding 1 per cent, or more of total amount of bonds, mort-
gages or other securities. Mortgage on building held by
Dime Savings Bank, Brooklyn, N V
C. W. Dibble, Vice-President.
HILL PUBLISHING COMPANY.
Sworn to and subscribed before me this 31st day of
March, 1916
RICHARD L. MURPHY,
Notary Public.
(My commission expires March 30, 1917.)
POWER
Vol. ll
NEW YOKK, AIMML 20, I!
No. L6
LT 1.30 lb.
coal per
kw.-hr.
and24 hr. a
day service,
the turbine
will use 504
tons of coal.
It would re-
quire a train
of 14 cars,
each carrying
about 35
tons, to haul a
day's supply.
A good miner
would be 5 1
days getting
out enough
coal to last
the turbine
unit one day.
The condensing water daily required by
the turbine is as great as the daily
water consumption of any one of
i the following cities: Hoboken,
N.J.; Manchester, N.H.; Sag-
inaw, Mich. ; Binghampton,
N. Y. ; Charleston, S. C. ; Gal-
veston,Tex. ; Norfolk, Va. ; Stam-
ford, Conn. ; Chattanooga, Tenn. ;
Woonsocket, R. I.; Superior, Wis.
Approximately 100,000,000 gal. of water
would be required for the condenser for a
24-hr. run at the rated load of 30,000 kw. The
sectional area of the intake tunnel is more than 138 sq
One of the Westinghouse "Cross-Compound" Turbines for the 7ith Street Station of the
Interborough Rapid Transit Co., New York City.
The turbine will furnish power for electric railway traffic. It can haul
at one time a line of people 36 miles long, allowing a space of only
two feet between each person. Used solely for illumination with
arc lamps it could light an area of 40 sq. miles with lamps
arranged as in lighting city streets. For the
same output the higher economy of
each of these turbines would effect
a saving of approximately 240
tons (2000 lb. each) of coal every
24 hr. over the consumption by
the engines which they displace.
IF the con-
denser
tubes were
slit and flat-
tened out
there would
be enough
metal to com-
pletely cover
over an acre
of ground.
Placed end to
end the tubes
would extend
36 miles. The
tubes are each
1 in. diameter,
No. 18 g~ge
and are all of
admiralty
composition.
V98t
(/ ;# Based on 24-hr. operation and
;/' with coal at $3.00 per ton this
would mean a saving of over $700
a day for each turbine. The old Man
hattan-type engines were installed in 1901
528
POWER
Vol. 41, No. 16
By Charles H. Bromley
SYNOPSIS— What the installation of 30,000-
lcw. cross-compound turbines has meant for the
Seventy-Fourth Street station of the Interborough
Rapid Transit Co., New York City. Many ex-
cellent views of the turbines, and of the station
during their insinuation . are shown. A table of
ratios and important data concerning the station
forms a valuable part of the article. See also the
Foreword in this issue.
'"The 5000-kw., direct-connected units now being built
by the E. P. Allis Co., of Milwaukee, for the main power
station of the Manhattan Railway Co., at Seventy-Fourth
and Seventy-Fifth streets on the Fast River, New York
City, are the must powerful steam-operated machines
of which we have any knowledge outside of the engines
of the great ocean steamers.''
So reads the opening paragraph of the leading article
in Power for June. 1901, which describes the units
installed in the Seventy-Fourth Street station of the pres-
ent Interborough Rapid Transit Co. These units were
the last word in large stationary steam engines. Yet three
have been, and a fourth is being, broken up for junk de-
spite the fact that they were in as perfect physical condi-
tion and that their economy was as good, as a month after
installation.
A Notable Example of Obsolescence
Amid the din of rock drills, hammer blows, rumbling
cranes, the hum of turbines and the clack of releasing
valve gears, this station is rapidly developing from the
old to the new. Yet it is little more than a decade since
these units were installed. Such is the rapidity of power-
plant progress, such the ruthlessness of obsolescence.
As is generally known, these old units have two cro.-s-
compound engines each — the low-pressure vertical, the
high-pressure horizontal — connected to a common crank-
shaft. The rated capacity of each is 8000 hp., but at one-
third cutoff. 150 lb. initial pressure, 26 in. vacuum and
75 r.p.m., each can develop a maximum of 12,000 hp.
The guaranteed steam consumption (dry saturated), un-
der the above condition but for normal rating, was 13 lb.
per i.hp.-hr. Today the consumption is nearly the same,
being 17.3 lb. per kw.-hr.
Why Low-Pressure Turbines Were Not Installed
The economy and the excellent physical condition of
the units have caused many to wonder why low-pressure
turbines were not connected to them, as practiced with
such satisfactory results at the company's Fifty-Ninth
Street station. Briefly, the chief reasons are these : First,
the economy of the turbine as a prime mover at the time
of the Fifty-Ninth Street installation was not nearly as
good as at present. Secondly, the engines at Fifty-Ninth
Street, in addition to being in excellent physical condition,
were designed for a higher pressure than those at Seventy-
Fourth Street, and. quite important, they have poppet
valves in the high-pressure cylinders, adapting them to
high-pressure superheated steam, while this advantage is
not possessed by the Corliss- valve units at Seventy-Fourth
Street. Thirdly, the complete expansion turbines (tur-
bine and generator combined) now going in at Seventy-
Fouiih Street were bought at a comparatively low figure —
about one-third the price per kilowatt paid for the engine
units. Fourthly, it is necessary to economize on space
at Seventy- Fourth Street, and complete expansion tur-
bines accomplish this far better than combination units.
For a more exhaustive analysis of the reasons for the selec-
tion of low-pressure turbines for the Fifty-Ninth Street
station and of complete expansion turbines for Seventy-
Fourth Street, see the article by the writer in Power,
Mar. 24, 1911. page 398.
Supplement to POWER, April 20, 1915. Vol. 41, No. 16.
Parts of the Westinghouse 30,000 Kw. "Cross-Compound" Turbine for the 74th St. vStation, Interborou^h Rapid Transit C<
1 Steam Piping Between High- and Low-Pressure Turbines
2 Ring of Intermediate Blades for Low-Pressure Casing.
3 Casting for One of the Spindle Ends.
One of the Two Low-Pressure Exhaust Openings
Bottom Half of Low-Pressure Casing.
Low-Pressure Rotor.
The Unit Comf
«
igh Rapid Transit Co., New York City.
■^ High- Pressure Rotor,
j 8 Low Pressure Side Assembled.
.* 9 The Unit Complete.
April 20, 1915
POWE II
529
Fig. 1. Note the Steam Passages in the Tube Bank. Condensers
si pported on springs mounted on screw jacks
As an indication of the advance in the economy of prime
movers in recent years, the water rate of the new turbines
for Seventy-Fourth Street is 30 per cent, better than for
the engines they displace. Fur 30,000 kw. output per day
of 24 hr., the turbine would save about $700 in coal alone.
Why Cross-Compound Turbines Were Selected
The chief feature of these 30,000-kw. units is that they
consist of two turbines, a high- and a low-pressure, erected
side by side. Each half drives a generator, the high-pres-
sure running 1500 r.p.m. and the Low-pressure 750; the
generators are tied together electrically. The turbine is
of the reaction type throughout, no impulse wheel being
used. The high-pressure element is single-flow, while the
low-pressure is a double-flow machine. By dividing the
unit into two unconnected parts the heat drop in each cas-
ing is also divided, which eliminates the distortions and
the consequent, severe stresses feared in large turbines
having single casings. Most important, however, is the
fact that by using two speeds the relations of steam ve-
locities to blade speed- may be correctly met in both the
high- and the low-pressure ends. The double-flow prin-
ciple as applied to the low-pressure end also obviates the
necessity of dummy pistons to balance the end thrust.
The advantages of the cross-compound principle from the
designers' standpoint have been so well brought out in an
article written especially for Power i Sept. 11, 1914, page
■ \~i 1 ) by Francis Hodgkinson,* designer of these units,
that tl e leader is referred to it for further particulars.
BOILEK PRESSURE INCREASED AFTEE THIRTEEN YEARS5
Si RVICE
Until shortly before the installation of the new tur-
bines, the Seventy-Fourth Street station furnished dry
saturated steam to the engines at 160 lb. pressure. As
the turbines are to have an exhaust pressure maintained
at 97 per cent, vacuum ( 29.1 in., or 0. 1 t2 lb. absolute), it
•Engineer, turbine department, Westinghouse Machine Co.
Fio. 2. The Gage Hoard for One
of the 30,000-Kw. Turbines
Fig. :;. This 32-In. Shaft, 16-In. Bole, I !u i thb ii
ix Three Hours with Oxyacetylene Torch
wa- desired to obtain the advantages of a higher initial
pie-sure than 1(30 lb. So the advisability of increasing it
to 215 lb. was considered. The boilers bad been de
530
POWER
Vol. 41, No. 16
for 212 lb., with a factor of safety of •">. though never
worked at that pressure, and had given thirteen years"
service.
Pieces were cut from the steam drums and subjected
to physical tests, which showed that the tensile strength is
greater now than called for in the original specifications,
55,000 lb. having been specified, while the tests showed the
present strength to be from 64.000 to 09,000 lb.
It is interesting to know that micrometer measurements
of the plates show them to be from 0.01 to 0.02 in. thicker
than the original specified dimensions.
After an investigation of all factors affecting safety,
the owners and the Police Department decided that 215
lb. pressure was permissible, and a well-known insurance
company assumed the risk at normal premium rates. In
the calculations used to determine if 215 lb. would be
an allowable working pressure, a factor of safety of 5 was
consequently, need more flue cross-sectional area, and
partly because the feed temperature is high with all-steam
auxiliaries, the economizers were removed. This enlarged
the effective flue area enough to increase the natural draft
I nun ().; to 1.25 in.
May Attempt to Cool Firebrick
It is the company's practice to set the firebrick in the
furnace side walls from the grate to a point a little above
the fire line, so that they may be renewed without dis-
turbing the rest of the brick. This is true of all refrac-
tory material in contact with the fire. Heretofore, the
same quality brick has been used below and above the fire
line. But as the furnace and fuel-bed temperatures with
the underfeed stokers will lie higher than with the over-
feed, it may be found expedient to use a better grade be-
low the fire line. In the hope of using a low-grade, low-
Fig. 4.
One of the Circulating Water Pumps.
( ' \i'\citv 37,500 G ll. pee M i\.
Fig.
Revolving Screens at the Condenser
Water Intake Tunnel
used. All cast-iron mud drums were replaced with
wrought steel, and steel fittings were put in to replace
the cast-iron one- removed.
Changes Made in the Boiler Room
The need for higher rating of the boilers at greater
economy was the deciding factor in the removal of the
overfeed stokers and the installation of those of the under-
feed type. With the former and the old engines 1150
kw. per stoker was the permissible maximum attainable,
while with the latter and the new turbine 3750 kw., or
225 per cent, more, may be satisfactorily carried. The
engineers for the purchaser state that the furnace effi-
ciency for the underfeed stoker is 10 per cent, greater
than for the overfeed in average running. The boilers
will operate at 300 per cent, rating during the peaks.
which come twice a day, each lasting about two hours.
As the boilers run at higher rating than formerly ami.
priced brick without experiencing the usual troubles, the
experiment of embedding in each side wall a pipe carrying
exhaust steam and air which will be discharged through
small holes in the walls, is being tried out.
Ratio Kilowatts to Boiler Horsepower
There are 70 boilers in the Seventy-Fourth Street sta-
tion, six of 600 hp. each, the remainder, 520 hp. Eight
of the latter were allowed for each of the 7500 kw. maxi-
mum capacity, reciprocating engines, giving a ratio of 1.8
kw. per rated boiler horsepower, installed capacity. It
is worthy of note that eight of these boilers will be al-
lowed for each 30,000-kw. turbine unit (see footnote under
table, page 531), a ratio of 7.2 kw. per rated boiler horse-
power installed, during peaks — the highest yet practiced,
though it should be understood, of course, that an equiva-
lent output is sometimes reached in other large plants
during peaks. Unfortunately, at this time an economy.
April 20, 1915
POWEK
531
Important Data, Seventy-Fourth St. Station
of the Interborough Rapid Transit Co., New York City, 1915
BOILERS
Total number of boilers 70
Heating surface, each, square feet —
Six 6000
Sixty-four 5200
Number of boilers with superheaters* 32
Superheating surface per boiler, square feet 968
Grate surface per boiler, square feet 92
Number sq.ft. heating surface per sq.ft. grate sur-
face 56.52
Number sq.ft. superheating surface per sq.ft. grate
surface 10.52
Number sq.ft. heating surface per sq.ft. superheat-
ing surface 5.37
Heating surface per connected kilowatt, sq.ft 1.386
Kilowatts per sq.ft. superheating surface 3.88
Kilowatts per sq.ft. grate surface 40.76
Kilowatts per boiler horsepower, installed capacity 7.21
Type of boilers Babcock & Wilcox
Designed for 212 lb. pressure with factor of safety of 5
Present pressure, lb 215
Boilers now have wrought-steel mud drums.
Boiler rating on peaks, 300 per cent.; between peak,
about 100 to 150 per cent.
Underfeed stokers, seven-retort •'Taylor,"
American Engineering Co.
Capacity of each stoker on peaks, kiv 3750
Chimneys —
Number 4
Height, above lower grate, ft 261
Diameter, inside, bottom, ft 18
Diameter, inside, top, ft 17
Boilers per chimney 16
Coal burned per sq.ft. grate, lb. per hr. —
At normal rating 19
At maximum rating 60
•Only 32 boilers would be required and would be actually
used to supply steam to three 30,000-kw. turbines, and of these
32 boilers it is anticipated that not less than four would be
out of service continuously for repairs, overhauling, etc. The
ratios are based on eight boilers per 30,000-kw. turbine, how-
ever.
TFRBIXKS
Three 30,000-kw. "cross-compoun
Builders The
Speed: High-pressure, 1500 r.p.i
750 r.p.m.
,000
i in present installation
Westinghouse Machine Co.
i.; low-pressure,
3-phase, 25-cycle,
Generators: Each,
11,000 volts.
The two generators of each unit are tied together
electrically.
Pressures: High-pressure initial, 200 lb.; initial
pressure of low-pressure side, 12 lb. abs. at
16.000 kw.; 15 lb. abs. at 25,000 kw. ; 19 lb. abs.
at 30,000 kw.
Superheat at throttle, deg. F
Vacuum, 97 per cent., or in inches of mercury
Performance guarantees: Operating conditions — 200
lb. gage pressure, 120 deg. F. superheat and
29 in. vacuum (referred to a 30 in. barometer).
Net Kw. Load
Lb, of Steam
of Generator
per Kw.-Hr.
15,000
12.07
16,000
11.94
18.000
11.77
20,000
11.54
22,000
11.40
24,000
11.30
25,000
11.27
26,1
11.32
28,000
11.47
30,000
11.63
Rankine Cycle
Efficiency, per Cent.
70.73
71.61
72.54
74.89
75.56
75.76
75.42
74.44
73.41
Most economical load, per cent, of max 24-hr. load
Steam consumption of auxiliaries, per cent, main
unit consumption —
At most economical load
At full load " '
Power consumption of auxiliaries, per cent, main
unit power, at full load
Blading, reaction; bronze throughout.
Peripheral speed last rows low-pressure, ft. per sec.
Total weight, lb
Weight per kilowatt, lb
Heaviest piece to be lifted by crane, tons
Floor space, outside measurement, sq.ft. approx...
Kilowatts per sq.ft. floor space
400
500,000
1600
18.7
R. Worthington Co.
50.000
in. long.
37.500
150
CONDENSERS
Builder Henry
Total tube surface, sq.ft
Tubes, admiralty, 1 in. diam., 20 ft. 3 =
18 gage.
Chief guarantee, 350,000 lb. steam condensed, water
at 60 deg. F„ 65,000 gal. water per min., main-
taining 97 per cent, vacuum, 29.1 in. mercury.
Tube area per kw., sq.ft
Circulating pumps: Two per condenser, centrifugal:
capacity each, gal. per min
T>'Pe Twin-shell, counter-current
Circulating-water pumping capacity per kw., gal.
per hr
Circulating-water pumping rapacity per lb. steam
condensed at consumption of 350,000 lb per hr.,
pounds
On guarantee, 65,000 gal. per min., lb
Diameter discharge pipe, in
Cross-sectional area intake tunnel, sq.ft.. approx...
Revolving, self-cleaning screens In intake.
Maximum speed of tide in river, miles per hr.,
approx
Area of each exhaust in condenser, sq.ft
Steam velocity through each exhaust opening, ft.
per sec
Reciprocating dry vacuum pump, size, in 14x39x30
Maker Laidlaw-Dunn-Gordon Co.
MISCELLANEOUS
Turbine foundations of structural steel
Kilowatts per cu.yd. concrete in foundation
The foundations for the 7500-kw., max. 24-hr.
rating engines each had 1500 cu.yd. of con-
crete.
Anticipated station load, kw
Total upward pressure of atmosphere on condenser
when carrying 29 in. vac, lb
107
138
7
142
227
100,000
290,566
P 0 W E I?
Vol. 41, No. 16
or performance-at-different-load, curve of this turbine
is not available for publication. It may be said, however,
that it is liberally 'designed, for tests show that the con-
sumption at full load is but little higher than that at the
most economical load. Also, the turbines — three are to
be installed for the present— will each easily earry 32,000
to 33.000 kw. with but a slight increase in steam consump-
tion. The two now in service each carry this load nearly
every morning.
Rubber Expansion Joints in Circulating Water
Pipes
There are two condensers, one connected to each low-
pressure exhaust outlet, and each is in three sections.
The total tube surface is 50,000 sq.ft., in 4T80 admiralty
tubes, each 20 ft. 3% iu. long, 1 in. diameter and of 18
gage. The chief guarantee is 350,000 lb. steam condensed
per hour with water at 60 deg. F., maintaining a vacuum
of 97 per cent. (29.1 in., or 0.442 lb. absolute). The steam
opening into each condenser is 142 sq.ft. in area. The
openings in the bank of tubes to assure steam getting
down around the bottom tubes are plainly shown in
Fig. 1. Fig. 2 shows the gage board used.
The circulating-water pipes which supply both con-
densers are 60 in. diameter. A novel feature of construc-
tion is that there are no expansion joints between the tur-
bine and condenser, each condenser being rigidly bolted
to one of the exhaust flanges of the double-flow low-pres-
sure turbine, there being provided a 36-in. connection
with a copper expansion joint between the two condensers
to maintain equilibrium of pressure. Hence, to provide
for the expansion and contraction of the turbine under
different operating condition-, it is necessary that the con-
densers be able to translate themselves with reference to
each other. This necessitates quite flexible expansion
joints between the circulating pipes and the water cham-
bers. Copper expansion joints were first installed, but it
was found that these held the condensers too rigidly and
that they would not move with the expansion and contrac-
tion of the turbine. This difficulty was overcome by sub-
stituting rubber expansion joints. Inasmuch as the pip-
ing was in place, the joint must be so designed as to make
use of the flanges and. to avoid special rubber work,
must admit of using plain sheet rubber instead of a
molded piece. The rubber is of a good grade and is five-
ply, Vii m- thick and made rip similar to belting.
Reference to Fig. 1 will show that the condensers are
supported on heavy springs resting on screw jacks.
The air pump is of the reciprocating kind, being
14x39x30 in.
Fig. 4 <hows one of the circulating pumps and Fig. 5
the revolving type of screen used at the intake.
Structural-Steel Supports
The economy in the use of concrete by using structural-
steel supports for turbines over the old solid engine foun-
da ns is well demonstrated at Seventy-Fourth Street.
The foundations for each of the 7500-kw. engine units
required 1500 cu.yd.. while for each 30,000-kw. turbine
supported on structural steel, but •.'7 5 cu.yd. is needed
and this chiefly to stiffen the supports against vibration.
This is the heaviest turbine yet to be supported on struc-
tural steelwork. Although the tandem-compound, 30,000-
kw. unit in Waterside No. 2 is so supported, it weighs
less. The condenser support of the Waterside structural
work has a system of spring beams to avoid the necessity
of an expansion joint between the turbine exhaust open-
ing and the condenser steam inlet.
In the removal of the large engines it was found ex-
pedient to cut the main shafts. These are each 37 in.
diameter with a 16-in. hole, and by employing the oxy-
acetvlene torch it took but three hours to make a cut.
See 'Fig. 3.
The Construction of tin-: Turbine
The high-pressure side contains 38 rows of blades and
differs but little from any other single-cylinder reaction
turbine. The first 8 rows are mounted on a ring bolted
to the casing. Following this are 19 rows mounted on
a second and longer ring, or barrel. The remaining 11
rows are mounted directly on the casing. The rotor is 20
ft. I--'S m. long. The views on the insert give a good idea
of the construction and size of one of the units.
The low-pressure turbine is double-flow. The casing
is a simple shell affair except that it has some interesting
reinforcing members. There is no blading mounted di-
rectly on the casing, but instead, it is all put on rings or
barrels bolted to the casing. One of the intermediate-
pressure rings for the low-pressure machine having the
blading mounted is also shown in the insert.
The low-pressure rotor is made up chiefly of a hollow
drum secured to two spindles, one at each end. The in-
termediate-pressure blades are mounted directly on the
drum, and the low-pressure blades are put on rings which
slip up over the spindles and are bolted fast. The spindle
castings with the risers weigh 72,500 lb. each and are of
steel. The rough ends without the risers weigh 38,500
lb. each.
A C©ffimein\l! foir ILeatlheir
To prepare a cement suitable for leather belts or for fast-
ening- paper covering to pulleys, get the best cabinet maker's
glue, in a quantity suitable to your requirements. A large
quantity can be prepared if desired, for it will keep for some
time after being mixed, if not permitted to dry out. Break
the glue into pieces and put in a dish, with water just
sufficient to cover it, and let stand twelve to fourteen hours,
or until all of the water has been soaked up. Then melt
the glue in a water or steam bath and add strong vinegar to
thin it. It should then be evaporated until it will appeal-
quite stringy from the stick or spoon used to stir it while
hot.
A leather belt should be roughed or furred with sand-
paper or a coarse file, which will make the joint stronger than
if the leather were left smooth. If the leather is warmed
before applying the glue, a better joint can be made. The
laps should be scraped down to a thin edge and their length
should be equal to the width of the belt. In making the joint,
lay the belt on a board so that the parts come even, then
fasten with a couple of nails through the leather a foot or
more from the joint on each side, so that when one piece is
raised from the other to apply the glue, it will fall back into
the proper position. Apply the glue warm and pound the joint
all over with a hammer and a block laid on the leather. A few
tacks driven through the joint will assist in holding it to-
gether properly until the cement has set.
The same preparation can be used for fastening paper, cloth
or split leather to a pulley to increase the driving power of
the belt. If of iron, the pulley should be well cleaned by
scraping and then washed with strong vinegar or a weak
solution of sulphuric acid in water. Wipe dry and apply the
paper, which has previously been covered with the hot glue.
Two or three thicknesses of heavy straw paper will be found
sufficient, and each layer should be firmly glued on. As soon
as the first layer is applied and before the glue has had a
chance to cool, roll or hammer the paper to bring it in con-
tact with the pulley. Each layer should be treated in the
same way. A belt should remain undisturbed for about five
hours after the joint is made, before an attempt is made to
use it. Three or four hours "ill be sufficient for the paper
covering on the pulley.
April 20, 191J
p uwiiii
533
This clutch, which is manufactured by the Akron < icar
& Engineering Co., Akron, Ohio, might be termed a
multi-disk cone clutch. In its design it retains the sim-
plicity of the two-cone clutch, allows Bmooth engagement
due to momentary slipping, and will release instantly. To
avoid a too sudden engagement of the cones their face an-
M ON
Ideal Multi-Cone Clutch
gles are greater than those of the ordinary two-cone type,
and tire clutching force and pulling power so lost are more
than compensated for by the addition of a third cone,
which practically doubles the pulling power. The cones
run in an oil hath which leaves a film between them and
permits a slippage before being broken down by the pres-
sure of coming into engagement. Owing to the face an-
gles and the small unit pressure on them, as well as the
oil hath, immediate disengagement occurs when the clutch
is thrown out.
-Means are provided to prevent the oil from escaping
to the outer surfaces where it would be thrown off by cen-
trifugal force. The horizontal pressure exerted by the
throw in the mechanism is distributed equally around the
circumference and does not distort the cones from a true
circle.
When the clutch is out the throwing mechanism is -till
and centrifugal force cannot throw it in. When it is in
centrifugal force cannot throw it out, hut will tend rather
to keep it in.
Referring to the illustration, tin- driving ring .-1 is keyed
to the shaft at B. The middle or driving cone 0 is driven
by the ring .4 through two feathers D; both friction sur-
face- of this cone contain oil grooves. The driven cones
E and F are brought into contact with C when the
shifter sleeve G is pushed in, thus throwing the rollers //
outward and forward against the adjustment ring I, which
carries the cone F forward into contact with C, and the
latter into contact with E. As the cone- come into con-
tact singly, too sudden clutching is prevented. The cone
F is caused to revolve with E by means of the lugs ./ pro-
jecting outward on /•', which lie between the lugs K on the
casing L. The inner faces of the lugs A" are turned true
ami hold the ring / central. The casing screws on the cone
E and is locked by the screw .1/. The inner end of the
locking screw A' projects into one end of the numerous
Blots 0 in the outside periphery of the ring / and i ai
it to revolve within the casing /.. The adjustment of the
clutch is made by inserting the screw into one of the -lots.
The rollers // and Q and their pivot pins are large in di-
ameter and in hearing area. The link.- /•' straddle the lugs
>'. the ends of which are raised slightly.
In throwing the clutch out. t he rollers // -t like the lugs
8 and pull tin' cone /•' forward, which gives the maxi-
mum clearance for the oil films between the cones. The
throwing mechanism is powerful, the multiplication be-
tween the horizontal force on the shifter sleeve Q and the
pressure on the cone faces being approximately 100 to 1
on all ■ .
g®
An unusually large fan for cooling air-blast transform-
ers ha.- recently been installed at the Blue Island Power
Station, Public Service Co. of Northern Illinois, by the
Buffalo Forge Co., Buffalo, X. Y. The installation was
made under the direction of Sargent & Lundy, engineer-.
It consists of a direct-connected hlower handling continu-
ously in. nun eu. ft. of air per min. at 70 deg. P. and 29.92
in. bar., with a static increase in pressure of 2.6 in. water
gage. The hlower is directly connected to a 30-hp., 25-
cycle, three-phase, t70 r.p.m. motor. Aside front the size
of the unit, the interesting feature is the operating speed.
Most transformer cooling units are 20,000 cu.ft. per
min. capacity or below, and although direct connection is
desirable, it ha- heretofore involved prohibitive expense
for the slow-speed motors necessary on larger units. The
hlower in tin- case i- a turbo conoidal high-speed type,
Motoe-Dbiven Fax of 40,000 CT.Ft. of Are pes Mix.
such as has been used in connection with motor and steam-
turbine-driven forced-draft units for underfeed-stoker
work. Althi res required for cooling
air-hla-t transformers are considerably less than for stoker
work, the -| cl of this fan is high enough to permit the
use of a motor at a price which is not excessive. The fan
is of the multiblade type with compact housing. The
photograph 3hows the relative sizes of the fan and the
motor. The fan has a static efficiency of 60 per cent, and
requires '.'? b.hp
534
P 0 \V E i;
Vol. 11. \.i. L6
TBneorettical ElnBicieimcy ©f Hei\t
Lmgiiinie;
By R. C. H. Heck
SYNOPSIS — Distinction between "actual" and
"ideal" efficiencies, explanation of tin- Carnot cffi-
i iency and when it should be applied, also the error
involved in using the "air standard" in connection
with the Carnot efficient!) in internal-combustion
ines.
The term "iieat engine" covers all forms of apparatus
onverting heat into work, and the only practical way
of making this conversion is by means of an expansive
medium which may be either a liquid (alternately vapor-
iiid condensed) or a dry gas mixture. In judging
the performance of a heat engine there are three efficien-
■ H - to be considered — actual, ideal and relative.
Actual efficiency is the ratio of the heat converted into
work (or work output measured in heat units) to the
plesl possible scheme, thermally, is that of the ideal Car-
nut engine, in which the temperatures of heat reception
and heat rejection are constant throughout the respective
operations, and in which there are no losses by radiation,
cylinder-wall action or machine friction.
The temperature-entropy diagram in Fig. 1 represents
the working of the Carnot cycle. The expansive medium
is ((infined in a suitable cylinder with a piston, and at .1
it has the upper temperature and a high pressure. Re-
ceiving heat at the constant absolute temperature Tv if
changes to state B by isothermal expansion. The quantity
of heat Qj received is represented by the area ABFEA ;
which has the width EF = Qx -+- Tx. This horizont
distance EF is known as the '"difference in entropy" and
will he represented by -V. Applied to steam, EA repre-
-i i its the absolute temperature corresponding to the given
pressure; the condition at A would be hot water at
A
B
1200-1
u
/
C
QfQ2
1000-1
/
«
B 380° F
c/
"V-
peratu
00
1-
w/
D
C
Q2
| 600-
| 40°-
A
y
E
D
a
a
E
B^-
^/
j/D
80° P
1
1
F
1
<
i
1
1
1
t^
I
200-
1
l
l
1
1
A
6
J
K H
0 E Entropy. N
F
0
0.5 1.0
Entropy, N
1.5
3 E
&
Entropy, N
F
Fig. 1
Pig. 2
Fig.
:l
heat supplied, these quantities being determined by tes
Experiment. No heat engine converts into work more
than a minor portion of the heat energy which it receive-.
Tin- i- due largely to the inherent nature (if the heat-
process and in lesser degree to imperfections of
actual material and operations. For any set of limiting
conditions it is possible to calculate, from thermodynamic
theory, the efficiency of an ideal heat engine, free from
all secondary imperfections.
This ideal efficiency is the proper basis for judgment
Mini performance. Thus, a conversion ratio of 0.2-1
for tlie best -team turbine may seem a poor showing, hut
when theory determines that an ideal apparatus under the
same conditions could convert only 0.34 of the heat re-
ceived, it appears that the real engine is doing about TO
per cent, as well as the ideally perfect one. In medium
to very good practice this relative efficiency, the ratio of
actual to ideal, ranges from o" to 75 percent.
Tin: Oahnot Engine
Any heat engine operates bj receiving heat at high
temperature, converting a part of it into work, and reject-
ing the remainder as lieai at low temperature. The sim-
this temperature, and the area ABFEA would represent,
the latent heat necessary to change the water into dry
saturated -team, which condition is represented at B;
finally. AH (= EF = .V) is the distance necessary to
make the area ABEFA proportional to the latent heat at
temperature T1.
At B in Fig. 1 the supply of heat is shut off and expan-
sion continues in the perfectly nonconducting cylinder
until the temperature i- lowered to T.. at <'. The drop in
temperature is due to the expenditure of heat energy in
the work of expansion; hut since no energy is transferred
in thermal form, there is no change of entropy. A no-
heat-transfer operation is called adiabatic.
From C to D the medium is compressed isothermally
(at constant temperature) at T... surrendering the heat
Q2 = AT, = area DCFED, and adiabatic compression
from D up .1 completes the cycle. With a heat input Q,
and heat. <>x — (J... converted, the efficiency is
F.
>, - <?,
(1)
which is a general expression applicable to all heat en-
April 20, 1915
powki:
535
gjiies. ffere Q, = XT, and Q., = XT,, so that the effi
cieney of this cycle may also be expressed by
E
m
1\ t1 + 460
in which /, and I., are the Fahrenheit temperatures cor-
res] ding to the absolute temperatures 71, and '/'_..
Sometimes this Carnot efficiency is used erroneously
as a standard when it dues not lit the conditions of the
actual plant. A notable example is found in the issue of
dune 9 last, in the abstract of a lecture by F. G. Gasche,
mi "Power In]' Steel Mills." For a steam turbine using
steam superheated to 700 deg. F. and with exhaust at 80
deg., the ideal efficiency is there computed as
700 — 80 620
11UO
E =
o.o35
700 ( ttiO
As a matter of fact, this result is about 60 per cent, in
excess of the correct value.
Ideal Steam Cycle
Fig. 2 shows the ideal cycle for the steam engine or tur-
bine, within the limits just named and with the addi-
tional datum that vaporization shall take place at 380
deg., or that the boiler pressure shall he about 195 lb.
absolute. The cycle begins at A with 1 lb. of feed water
at exhaust temperature pumped into the boiler. Curve
AT, represents the heating of the water up to the boiling
point of 380 deg. F., or 840 deg. absolute; it receives heat
and acquires entropy as the temperature rises. The hori-
zontal line EC represents the isothermal, or constant-tem-
perature, operation of vaporization. At C the steam is
dry saturated, and its superheating from 380 to 700 deg.
is represented by curve CD. At D the total heat of the
steam is 1370 B.t.u., and the heat imparted, beginning
with water at 80 deg. F. (540 absolute), is 1322 B.t.u.,
represented by area (IABCDHG.
The operation ABC I) is performed in the boiler, and
we assume that the steam is carried over to the engine
or turbine without, loss of heat by radiation or of pressure
by pipe resistance. Then adiabatic expansion, whether in
the ideal non-conducting cylinder or in the formation and
utilization of a perfect steam jet. lowers it to stale T.
Abstraction, of heat in the condenser, of the exhaust heal
Q., (area EAGHE = 879 B.t.u.), is represented by the
isothermal line EA. The ideal efficiency is now, as
against the 0.535 previously figured, only
0,
1322 — 879 I i:i
-7322— = 1322-a335
The diagram shows clearly the error involved in using
for T, in the t'amot expression, equation (2), the highest
temperature reached by the medium, instead of making it
the temperature id' heat reception. When the latter tem-
perature varies, as here, it might be replaced by a mean
value of equivalent effect, although that is not the direct
or the better way of calculating E. Just to see how
nearly the vaporization temperature of 380 deg. would
come to serving as such an effective average value, try it
in equation (2), from which will be found
E =
30U
380 — 80
380 + 400 ~ 840
= 0.357
Evidently t1 = 380, or 1\ = 840, is a little too high for
this purpose.
Because so much of its heat reception is at T, and all
of its heat rejection at T ... the steam cycle is fairly near
tin' Carnot in general form. The practical reason for this
is that the constant-pressure operations of vaporization
ami condensation are characterized also by constant tem-
perature. Bui in no sihei £ gas-engine working do
isol hernial opera! ions find place.
1 1 1 to Gas-Engine Cycle
Consider the Otto cycle outlined in Fig. 3. The opera-
ion begins at .1 with a charge of gas mixture under at-
mospheric pressure and of a little higher than atmo
pheric temperature. Line AT, shows adiabatic compres-
sion, follow i'il by tbr reception, at practically constant
volume and with a rapidly rising temperature, of the heal
of combustion. This beating ahum curve BC is followed
by the ideal adiabatic expansion CD, and exhaust is taken
to be equivalent to constant-volume cooling along curve
DA. The actual performance, in an actively conducting
cylinder and with combustion more or less retarded, is
somewhat of the form sketched by the dotted line.
It has been usual, for a simple calculation of theoretical
efficiency, to assume that the gas mixture is practically
the same as air in properties and that its specific heal i
constant, not rising with temperature. Under the latter
assumption the ratio of low to high temperature is the
same on any ordinate in Fig. 3, whether at the extreme
lines BE and CF or on nnv vertical //>/. If then
T,
Th
. etc.
it is evident that the conversion area ABCDA will be to
total heat area EBCFE as TB — TA is to TB, or that
the Carnot ratio will apply if the limiting temperatures
of either adiabatic are used in place of certain constant
temperatures.
The principal purpose in writing this article has been
to lay before the readers the fact, to be found only in the
more recent textbooks, that the use of this simple air
standard involves a large error. Computed results from a
typical example are laid out in Figs. 5 and 6, where the
dotted diagrams marked n are for ideal air and the full-
line diagrams h represent the behavior of an actual gas
mixture.
The medium selected in the example is a blast-furnace
Lias with a moderate excess of air in the combustible mix-
ture. Its heal value is such that perfect combustion gen-
erates ju-t looo B.t.u. per pound of mixture, the diagrams
being drawn for that quantity. The specific heat rises
with tin' temperature according to the constant-rate law
shown by straight lines Nos. 2 and 3 in Fig. I. id' which
No. '-' is for the original mixture anil Xo. 3 for the prod-
ucts of combustion; line Xo. 1 shows the uniform value,
Cv = 0.169, for the ideal air medium.
One main determinant is the pressure of 175 lb. abso-
lute at the end id' compression in Fig. 5 (points /; and
/."). This and the initial atmospheric pressure and an
assumed temperature of 80 deg. F.. or 540 deg. absolute,
at .1 and .1' are the only conditions common to the two
cases, although the compression curves AB and A'T' are
very much alike. The greatest difference is -ecu in the
temperature rise from T> to (' and ]',' to c", with the re-
sulting expansion lines CD and CD'. Curve c is a rough
gues> at l he probable actual indicator diagram.
Of course, such a tremendous rise of temperature as
that which tarries <" up to more than 7000 deg. in Fig. 6
and the corresponding pressure to 1100 lb. in Fig. 5 is
53G
P 0 \Y 1: B
Vol. 11, No. 16
physically impossible. Even the more reasonable height
of point 0 runs into a region where dissociation is prob-
ably a potent influence and where our knowledge of spe-
cific heat is vague. But disregarding the fact that the
conditions of diagram a are largely imaginary and those
of b in some degree doubtful, the results of calculation
may be summed up as follows:
In diagram a, Fiji. C, the four corner temperatures are:
TA = 540 deg., TB = 1104 deg., Tc = 7021 deg.: and
TD = 343 1 deg. Then the efficiency is
E
1104—540 7021 3434
= 0.511
1104 7Q21
In diagram b the corresponding temperatures are:
TA = 540 deg.. TB = 1092 (leg.. TC = 1818 deg.. and
TD = 331.") deg. With these the Carnot ratios at the lim-
iting ordinates BA and CD are very different, being
1092 — 540
[092
= 0.505
4818 — 3315
and 1818 M"'-
A notable effect of higher specific heat is the relatively
smaller vertical width of the effective area ABCDA, as
0.4-1
0 Z 4 6 8 10 12 14
Specific Volume, Cubic Feet perRaund
■ Fig. 5
compared with A'B'C'D'A' ( Fig. 5). Efficiency is found,
however, not from temperatures but from heat quantities,
as referred to in the method of equation (1). Along
curve BC (Fig. 6) the heat received from combustion is
1000 B.tu., while that rejected along DA is 632 B.t.n.;
then the effieiencv is
/:
632
L000
= 0.368
The physical data for a calculation such as is repre-
sented by diagrams 6, Figs. 5 and 6, are not complete in
full accuracy. The methods of calculation arc more
directly related to Fig. 5. involving data as to pressure,
volume and specific heat: and the heat converted, 368
B.t.u., is strictly equivalent to the work area ABCDA in
Pig. 5. When entropy is calculated, rather as a secondary
quantity, a discrepancy develops: the diagram in Fig. 6
failing to close by the amount .1,-1.
lness OF Ideal Efficiency
Ideal efficiency, or the performance and output of the
Rankine cycle represented by Fig. "2. is regularly used as
a standard of comparison for steam action: but with in-
ternal-combustion engines it is little used. The simple
air standard is so much in error as to be worthless, and
the more correct method requires complicated ami diffi-
cult calculations. For one thing, it musl start in each
case with the proportions of the particular gas mixture,
upon which the average fundamental physical properties
of the medium are dependent : and even with the simple
straight-line law for variation of specific heat with tem-
perature (itself probably no more than an approxima-
tion), the change of temperature in an adiabatic operation
can be found only by a troublesome trial solution. Merely
to -tate and outline tlie calculations for Figs. 5 and 6,
including a number of intermediate points on each curve,
would take considerable space, with no explanations or
ifs; and while the direct calculation of ideal efficiency
alone is much shorter, it is yet rather beyond the scope of
ordinary use. Therefore, gas-power engineers will prob-
ably continue to ! witli actual efficiency as a
measure of performance.
The really important result from the example here sel
C
7000-
.1
A
,.6000-
i i
/
/ i
/ i
c
/
/
H 5000-
U-
c
! /
/ 1 yS
£ 4000-
a/ /<
H
b 3000-
/ b/-^ /*
E
CO
E
P 2000-
'"ts^^ ^^^^
_2
s
B
-^
< 1000-
n-
A,A
540
Absolute
0 005 0.10 0.15 0.20 0.25 0.30 0 35
Entropy of one Pound of 60s Mixture
Fn.. 6
forth is the relatively low value, 0.37, for true ideal effi-
eiencv. as against 0.51 under the assumption of constant
specific heat. Considering the intense action of the cyl-
inder walls in a gas engine, the relative efficiency is not
likely to be over 0.6. Applying this to 0.37, we get a
probable actual value of 0.22, and see that so far as the
conversion of the heat supplied to it i- concerned, an
engine using blast-furnace gas is much in the same class
with g 1 steam engines and turbines. This does not, of
course, deny the great economy of using such gas directly
in the engine instead of burning it under steam boilers.
Coal for foke — In the last five years the coal used in
metallurgical coke manufacture has averaged around 65.577,-
000 tons, yielding 43.983.000 tons of coke, valued at Sill, 736.000.
i if this total. 14.767.000 tons were used in byproduct coke ovens,
yielding, besides the coke 54,491,000 cubic feet of gas 94,306,-
000 gallons of tar, and $9,190,000 worth of ammonia. When it is
considered that every year approximately four times these
enormous totals of byproducts are absolutely wasted tli
the use of non-byproduct ovens, the vital importance to the
country of a general use of the modern, scientific byproduct
ovens will \>e appreciated. — "Journal of the Franklin Insti-
tute."
April 20, 1915
POW E R
537
s©ip~ Valve Tes£
In the endeavor to test to destruction one of the feather
valves now being used by the Laidlaw-Dunn-Gordon
plant of the International Steam Pump Co., for air and
gas compressors, the builders fitted a small vertical
compressor with one of the standard-type feather valves
and with an annular valve of the so called low -lift,
plate type, the latter being of standard German manu-
Fig. 1. Seating Surface of Feather Valve. The
Lighter Portion Shows the Surface after
Forty Million Revolutions of the Pump
facture. The valves were used alternately for intake
and discharge. The compressor was operated at a speed
of 560 r.p.m. against a pressure of 10 lb. during each
working day of ten hours, for a period of six months,
aggregating in that time something over forty million
revolutions. During this period three of the annular
valves gave out, while the original feather valve at the
end of the period had gone no further than to perfect
its seat. Fiir. 1 is a photograph of one of the blades
used, the lighter portion indicating the polished surface
of the seating area.
Forty million revolutions represents about a year's op-
eration at 225 r.p.m. The speed of 5G0 r.p.m. should.
on the basis of ordinarily accepted practice, result in
destructive action four times as fast as a speed of 280
revolutions, which represents about the limit of commer-
cial practice at present. The builders claim, therefore,
that this run of forty million revolutions at 560 r.p.m.
i.- the equivalent of at least four years' normal run-
ning, and the valves, judging from their appearance,
had not even begun to deteriorate.
The valve on which this test was made is designated
by its builders as the Laidlaw feather valve (patented),
seat on the ground face of a slotted casting, the slots
being slightly smaller than the strips. The valves are
not held rigidly at any point, but are restrained in
movement bj a curved guard with slots staggered to the
slots in the seat, the spaces between being milled out on
a curve against which the valve bows up when in an open
Fig.
Three Elements Comprise the Feather Valvi
Fig. 2. The complete contrivance consists of three ele-
ments only. The valves proper are strips of light flexible
flat steel stock similar- in appearance to ordinary clock-
spring stock, but more flexible and of a much lower
temper. These strips, which in the average valve are
about y2 in. wide and vary in length from 4 to 12 in.,
Pig. ::. Details of the Valve Assembled
position, to allow the passage of air. The ports are
shown in Fiir. '■'•.
The guard is lightly bolted to the seat, the strip-
being thus held between, free to bend up and down in
the middle, their ends always remaining in contact
with the seat, giving a breathing rather than a slapping
action. The movement of the valve is controlled by
the air flow, the valves themselves having negligible
spring action, the best results being obtained with the
highest flexibility. They are so light as
to respond instantly to change in air
flow, their flexibility not only permit-
ting air to flow through them with a
minimum of spring resistance, but also
resulting, with the reversal of air travel,
in almost perfect contact with the seat.
The notable feature of this valve as
compared with (be older type of poppei
or with the newer type of low-lift plate
valve, is the fact that it seats not l>\
impact of the entire valve, but by in-
creasing contact from the ends to the
center. This characteristic, in com-
bination with extreme lightness and
flexibility, not only results in the
marked durability demonstrated by the
b-t rallied out, but also permits a lift area greatly in
excess of that obtainable with the annular low-lift typo.
seating by impact. The valve as applied to a compressor
is shown in Fig. I.
In efficiency of performance the valve shows actual
measured volumetric efficiency approaching within less
-
POWER
Vol. 41. N . 16
Fig. 1. Feather Valves Applied to an Air Com:
than 1 per cent, of the efficiency indicated by a diagram.
which latter indicated efficiency shows only the reexpan-
sion loss from clearance. This close approach of the
actual to the indicated efficiency is a significant check
on the valve performance, inasmuch as the clearance
reexpansion indicated by the card, and which is" inevit-
able in any practicable air compressor, is not an econ-
omical loss, the energy return of the clearance reexpan-
sion being practically identical with the energy absorbed
in its compression.
Contact seating, in addition to contributing to a high
degree of durability and permitting the high lift which
gives the valve its exceptional efficiency, also accounts
for its remarkably quiet action.
Extreme simplicity of makeup permits the valve to
be made reversible as regards seat and guard, so that
the same valve can be used in its cylinder optionally as
an intake or a discharge valve, the construction of both
being identical and their function being determined only
by the relation of the seat to the cylinder bore,
j ]
Mtiag|eia<lI>s HIradiiic-m£©s:, 3R@dltiaeaK&g|
A simple indicator reducing motion has been designed
recently by Win. W. Nugent & Co.. of Chicago. It may
be attached to any Nugent telescopic erosshead-pin oiling
device or to a special stand on the floor. The former
Fig. 1. Nugent Redtji inc. Motion
Attached to Crosshead-Pin
■-'; Device
Fig. 2. Sim: View
Reducing Moi [ox and
Oiling Devi* i:
of Fig. ■".. Reducing Motion Supported
bi Stand Secured to the
Floob
April SO, I91i
I'o W E K
539
method of attachment is shown in Figs. I and 2 and the
door stand in Fig. 3. Either i> mounted at the center of
the stroke.
As shown in the Srst two illustrations, the reducing
motion consists of a forked member which straddles and
is clamped to the oiling device mounted on the top guide
to the crosshead. The forked member just referred to
supports two horizontal tubular guides for an oscillating
block which reproduces on a smaller scale the motion
of the piston. The block is moved back and forth by
the telescopic tube of the oiling device. A pin that is
free to turn passes horizontally through the block. The
former is bored radially to allow the telescopic tube to
pass through.
A given point on the tube naturally moves in the
an- of a circle, but the arrangement allows the block
to travel horizontally, as it may slide along the tube
away from or toward the fulcrum, as it moves either side
of the central position. As the pin is free to turn, there
i no binding action on the tube. The cord is attached to
this same pin and on its way to the indicator passes
through a swivel guide pulley. The device accurately
reproduces the motion of the piston and can be easily at-
tached to or removed from the supporting element.
A Q^jesftnoim PuazzsMir&g &<a> Soma©
Many of our very practical engineers do not understand
the reason for the greater efficiency or economy of a com-
pound condensing over a simple condensing engine. The
prevailing idea seems to he that power ami efficiency are
derived only from a greater number of cylinders. The
principal difference in the two engines is entirely over-
looked— the difference in the loss of heat through cylinder
condensation; otherwise the greater number of cylinders
would he of no advantage, hut a disadvantage.
Consider the diagram of a 300-hp. simple condensing
engine, admitting steam at a pressure of 300 lb. absolute
and a temperature of 287.2 <]eg. F. and expanding down
to 1 lb. absolute and 102.9 deg. F., thus losing 2s 1.4 deg.
F. ; or, in other words, admitting steam at the high tem-
perature of 387.3 deg. I'1, into a cylinder which has been
cooled to some extent by the expanded steam at 102.!) deg.
F., thus condensing and Losing a large percentage of the
incoming steam in reheating the cylinder.
With a compound engine with steam at the same pres-
sure and temperature, and the high-pressure cylinder
expanding it down to 27 lb. absolute at 245.1 deg. F., the
temperature difference between the admission ami exhaust
is only 142.2 deg. F. This exhaust from the high-pressure
cylinder is admitted into the low-pressure cylinder at
practically the same pressure and temperature, and ex-
panding in its turn to 1 lb. absolute and 102.9 deg. This
makes a difference of I 12.2 deg., the same' difference of
temperature between the admission and exhaust in the
high- and low-pressure cylinders.
By having two cylinders, as in the compound engine.
the extreme difference in temperature met with at admis-
sion in each cylinder is reduced.
Kate of Combustion is the amount of fuel burned per hour
per square foot of grate surface. It varies from about 5 lb.
in small furnaces to 100 in large furnaces under forced draft.
The ordinary rate for anthracite is from 5 to 15 lb. and for
bituminous coal 5 to 25 lb.; in locomotives, from 45 to 90 lb.
Juastt for FuHia
A foreigner who spoke very little English was second
fireman in a plant id' eight 150-hp. horizontal return-
tubular boilers. The so called "Hunkie" was told one
day to take one of the boilers out of service for cleaning
and repairs, lie shut the header valve all right, and when
the steam pressure had fallen to 60 lb. he went to blow
down the boiler, hut the blowoff pipe was completely
stopped up. lie then took the blind flange oil' the cross on
tin' end of the pipe and commenced poking at the obstruc-
tion with a rod while there was still CO lb. pressure on
the boiler. Somebody caught him before he completed the
"suicide act."—/''. F. Jorgensen, Gillespie, 111.
In a plant where I was employed a man who was in-
terested in the plant and was supposed to understand elec-
tricity came in one evening during the peak-load period.
There were two machines, and Xo. 1 was permanently con-
nected up, hut No. 2 was only temporarily connected,
and in such a mi or that one main circuit-breaker served
both machines, although only one could lie run at a time.
The feeder switches were all of the quick-break type.
These switches were something new to the gentleman,
and I showed him how they worked, and remarked that
the large one was the main switch for the idle machine.
At this time I turned to a storage-battery panel, and
hang went the circuit-breaker and everything went out.
He had simply tried that large quick-break switch, hut
when things were in order again he remarked: "I guess
it is a good idea to leave things alone that we are not
acquainted with."
In this same plant we were required to take ground
readings from all of the circuits once a day, before the
evening load came on. The "boss" had a ha hit of coming
in frequently and pulling out and putting in switches
and watching the effect on the ground indicator. On one
occasion he came in before I had tried the circuits and
proceeded as usual. It happened that I went over to
the engine while he was engaged with the switches and co-
incident with my move he threw in a switch which had
been open, and started a commotion. I was innocent of
any connection with the short-circuit, which was on that
line, but circumstantial evidence was against me. Our
"friendly relations'" were not ■■-trained" at all. hut the
"boss" sort of lost interest in grounds. — 11. L. Strong,
Yarmouthville, Me.
The fellow who painted the commutator has nothing
on a painting stunt pulled oil' by one of my men last
fall. I decided to give the machinery a coat of paint.
The hoys prided themselves on the appearance of the
lagging, valve-gear and especially the well polished cylin-
der head of a Corliss engine. One afternoon all the paint-
ing was completed with tin' exception of an oil guard on
this engine. The middle-watch man was told not to run
the machine that night, hut to finish the painting job.
The following morning I found our nice lagging, cylin-
der head, bonnets and valve-gear, including the sole plate
and dashpots, all painted green, and it had begun to run
and then baked. The color of the atmosphere was "some
variegated" wdiile we were scraping paint. — E. B. Mertens,
Milwaukee! Wis.
540
POWER
Vol. 41, Xo. 16
By Norman i). Meade
Dispatching of passenger elevators in large office build-
ings has received considerable attention recently, and it
has been the aim to obviate the human element as far as
possible. The engineering stall' of the Insurance Ex-
AdjuSting Screw
Horizontal
Revolving
Wheel
Fig. 1. Plan of Dispatcher
change Building, Chicago, has designed and installed an
automatic electric dispatcher which times the starting of
the elevators from both the bottom and the top floors.
This building is a modern 18-story office structure cover-
ing half a city block and is equipped with sixteen electric
passenger elevators arranged in four banks on four -
of the building.
elevators are of the Otis traction type, operated
by 25-hp., 220-volt direct-current motors controlled by
Otis type MF4 controllers. Eight operate as express cars
and eight as locals. The floor signals fur the former nor-
mally do not operate below the twelfth floor, but on occa-
■ _■ of Contact
' in each Revolution
Fig. 2. Cam ami Spring Contact
sions such as Sundays and holidays, a switching arrange-
ment is provided which throws in the signals for all flour-.
The automatic dispatcher presents several novel features
and signals the starting of the elevators independently of
the hall men. who merely direct persons to their desired
ation in the building.
There is a bell located at the top and at the bottom of
each bank of elevators, operated by the dispatcher. Thi>
bell is adjustable so that the timing of the cars may range
from 20 to 60 sec. A 220-volt to 15-volt motor-generator
set, with an auxiliary storage battery, furnishes energy
for the dispatcher.
Fig. 1 is a plan view of the dispatcher, which consists
essentially of a horizontal revolving disk operated through
••educing gear- by a %-hp. motor at a constant speed.
Four vertical columns attached to the slate base support
four independent hollow shafts to which are attached fric-
tion wheels and cams: a contact spring rest- on each cam.
but is normally out of electrical contact except once in
each revolution. The horizontal shafts arc hollow and in-
Llevator J.- -
A.5.C.D Automatic
Disp-~ '
Contacts
B r-*C
HOY-ttains,
Fig. 3. Wiring Diagram of System
close a threaded rod which engages with a central pro-
jection from the friction wheel that passes through a slot
in the shaft. Hence, the position of the friction wheel
on the shaft can be varied by turning the adjusting screw
one way or the other. Moving the friction wheel toward
the center of the revolving disk decreases the speed and
moving it toward the outer edge increases it.
Details of the cam and spring-contact arrangement are
shown in Fig. 2. The former is insulated from the latter
by a fiber shoe, except when the spring escapes over the
April 20, L915
row E it
541
lip of the cam, and an open circuit normally exists.
Fig. 3 is a wiring diagram of the motor-generator sei and
the dispatcher with its switchboard. The double-pole,
double-throw switch in the center of the board is for dis-
connecting the motor-generator set and connecting the
batteries in case of e rgency. A relay is connected in
the generator circuil and in case of failure of the latter,
releases its armature which closes a local circuit and
lights a telltale lamp, warning the attendant.
The dispatcher equipment on the hoard consists f
four sets of fuses, four double-pole switches, four telltale
lamps, and four relays — one o tlit Fur each hank of ele-
vators. As the horizontal shafts of the dispatcher re-
volve,, contact is made each revolution as the contact
springs slip over the lips of the cams, tlcsing the circuit
through the relay coils and the single str ke bells which
are connected in series. The relay draws down its arma-
ture and closes the circuit through the telltale lamp, which
lights, indicating that the signal lias been given. Cars
star! in order in cadi bank of elevators, one after the
other at the signal, and return from the top in the same
order on receiving the signal.
flffiig
efteir
The recording pyrometer shown is of a new type devel-
oped by the Wilson-Maeulen Co., 1 East Forty-Second St.,
New York City, and is to he marketed under the trade
name of "Tapalog."
"Tapalog" Autographic Pyrometeb
A special feature of this instrument is that the carriage
containing the record paper, typewriter ribbon and other
recording mechanism is pivoted to drop away from the
galvanometer so that the paper and ribbon can he changed
without danger of injuring the galvanometer.
The record is taken on the under side of the strip. The
tracing paper used is visible from both sides and the
speed of the reei id is 1 in. an hour. A dot is made
every T2 seconds, and during the intervening period the
pointer is free to swing to its line position.
The depressing member which makes the dot is oper-
ated by a three-cell dry battery; the dock merely shows
tlie time. The indicating scale is mounted on the front,
of a "hopper bar thai is pulled down by an electromagnet,
with a blow to make the record, and this bar is over-coun-
terbalanced so that it tends lo rise quickly after the down-
ward stroke, at the bottom of which the electromagnetic
circuit is opened.
The Tapalog will take a single record of one tempera-
ture in o -olor, hut it. is generally furnished with an
automatic switch which, every minute and a half, switches
I he Tapalog from one thermocouple to tin' next, and
brings another portion of the multi-color typewriter rib-
bon under the pointer, so that the different records are
taken in as many as four distinctive colors.
Multiple recording is important, for instance, in a
large furnace where thermocouples are inserted at differ-
ent points: the r cords, all being on one sheet, show defin-
itely whether the furnace is evenly heated or just what the
degree of uneven heating may be — the whole graphically
set forth in a multiple record. The ribbon that passes
under the record paper is made in the form of an endless
belt so that it is not necessary to employ any mechanism
to reverse the direction of travel.
This pyrometer may be located a long distance from the
furnace, and to overcome shrinkage it is provided
throughout with bakelite disks, washers, plates and other
working parts.
Stteavm-TwiT'IbSirii© JRcaMiimgHiMIlIill
The rolling min has been one of the last stands of
the large reciprocating engine. The Carpenter Steel
Co., of Reading, Penn., lias, however, recently installed
a low-pressure steam turbine for driving two stands of
18-in. three-high mills. The turbine is of the De Laval
multi-stage impulse type, in nine stages. It runs at
5000 r.p.m., and the speed is reduced by double helical
involute gears, first to 600 and then to 100 r.p.m. The
Jahns governor, with which it is supplied, may be adjust-
ed while the machine is in operation, to vary the speed
from 100 to 70 r.p.m. on the mill shaft.
The turbine will operate normally with 3 lb. gage
pressure at the turbine throttle, and with 3 in. absolute
pressure in the turbine wheel case at the exhaust end,
under which conditions it will carry 350 hp. at the speeds
mentioned and require not more than 2(1 lb. of steam per
hour per brake horsepower, the power being measured
at the end of the second gear reduction. It may be run
low-pressure condensing, mixed-pressure condensing, high-
pressure condensing, ami high-pressure noncondensing.
"With 120 lb. pressure at the throttle and 3 in. absolute
pressure in the turbine wheel case, it is guaranteed not
to require more than 17% lb. of steam per brake horse-
power-hour. As a mixed-pressure turbine, with the same
pressure conditions, it will carry 600 b.hp. continuously,
and is also designed to carry the full load of 600 hp. on
the high-pressure steam alone, under which condition it
is guaranteed to take not more than 15.7 lb. of steam per
brake horsepower-hour.
American Cicar Co.'n Plant — We have been informed by
Clark, JMaellullen & Riley, 101 Park Ave., New York City,
that the plant of the American Cigar Co., Garfield, N. J.,
described by W. L. Durand in Apr. 6 issue was designed and
installed by them. This building is the first in the country
used exclusively for cigar manufacturing to put in an au-
washing system.
5-12
POWEK
Vol. H, No. 16
Vacviatuiina Fltjaidl Coolies5
This device has been designed for the purpose of
reducing the temperature of water below that of the sur-
rounding atmosphere. Referring to Fig. 1, where the
Fig. 3. As the air enters through the coolin.e chamber
it is compressed by passing through a smaller orifice at a
high velocity, and is thereby reduced to about 65 deg., at
which temperature it is drawn through the cooler and
comes in direct contact with the falling water. The
method of baffling the water and the air by means of
tongued baffle plates, Fig. 1. causes the drops of water to
Fig. 5. Perforated Steel Pan
FIG. 4 FIG3
Fig. 2. Air-Cooling Chameer. Fi<;. 3. Strainer.
Fi<;. !. Tongued Baffle Plates
cooler is shown in the form of a rectangular tower, the
air is taken through the air-cooling chamber, details of
which arc shown in Fig. '2. at a velocity of about 2000 ft.
per min. In this chamber is a manifold sprayer which
subdivides the water after it has passed through a strainer.
Fig. <;. End View of Cooling Tower
come in contact with the cooler air twelve or fourteen
tunes during their fall from the inlet to the outlet.
At the top of the cooler is a steel pan about twenty
inches deep (Fig. 5), into which the hot water from the
lenser is pumped and the bottom of which is perfo-
April 20, 101
P 0 W E II
543
rated at regular intervals with 1-in. holes. Each hole is
connected to a funnel-shaped tube, Fig. I, which tapers to
14 in. diameter at the base, thus forming sprayers. These
(lilies are so designed thai with the weight of water which
passes through it is impossible For them to become clogged
or to retain any foreign matter that may he in the water.
The water is distrilmted to the t nlies in the form of a
Bpray, and when sufficient is in the pan to cover the holes,
the exhaust fan. Fig. 6, placed under the tube, forms a
partial vacuum into which is precipitated the falling hot
water and vapor.
The exhaust is under the top pan. By circulating the
water through the cooler alter il has heen heated from
mii to 160 deg. F. in passing through a condenser, it is
brought back to he used again at a temperature of 70 to
73 deg. F. after passing through the cooler.
This cooling tower is manufactured by the Vacuum
Flue & Cooler' Co., >i)5 Highland l$ldg„ South Highland
Ave., Pittsburgh, Penn.
x
ILsurfge ID) ©^a lb He EaxIhgiAuisft Faftftiiir&g*
The accompanying illustration shows a 72-in.. cast-
iron, double exhaust fitting which was recently made in
the shops of the Hunsicker Engineering Co., Lebanon,
Penn. So far as known this is the largest fitting of
its kind ever made in the East.
It is used in connection with a 5000-kv.-a. turbine,
1500 r.p.m., at 80 lb. boiler pressure. The condenser
used in the equipment is a No. 23 barometric type. The
double outlets connect with the expansion joints of the
Two Views of 72-In. Double Exhaust Fitting
turbine and the large end connects with a 72-in. exhaust
line. It weighs 11 tons and is is ft. in length over all.
The Kfficienoy of Compressed Air can be greatly increased
by reheating. The gains are both direct and indirect, the
chief direct gain being in the greatly increased efficiency of
fuel used in the heating stoves as compared with the effect
when coal is burned under boilers. It is commonly stated,
and the statement is fairly correct, that when 1 lb. of coal
is burned in a reheater stove the commercial effect is as
great as when 3 lb. are burned under a boiler. The increase
in commercial efficiency when reheating air from 60 deg F.
to 400 deg. F. may be put at 35 per cent. The indirect gains
are better lubrication of the compressed-air engine, less
Investment required, as a smaller plant will be needed, re-
duction of compressor-engine friction as compared with the
useful work done. — Exchange.
I'.y E. o. Watbes
The theory of belting, as presented in standard hand-
hooks, does not seem to harmonize with examples taken
from everyday practice. There appears to he conflict be.-
tween textbook theory and machine-shop practice, but
this conflicl is more apparent than real.
Primarily, a belt is made in such a length that it will
he stretched enough to give il an initial tension. When
the driving pulley starts it will ause one-half of th
belt to tighten and the other half to become more or lesi
slack. When the difference in tensions becomes slightly
greater than the resistance of the driven pulley, it, in
turn, will start up, provided the resistance does not exceed
the maximum value determined by the coefficient of fric-
tion between the belt and pulley surfa e and the arc of
contact made by the belt. This maximum ratio is that
number whose common logarithm is 0.00758^^, where /*
is the coefficient of friction and 6 is the are of contact
measured in degrees. For any proposed installation of
belting ft is known (it is usually about 180°) ; and n was
determined many years ago by hanging pieces of belting
with weights attached to the ends, over fixed sheaves, and
finding out what excess weight hanging from one end was
required to produce slipping. Accordingly, our maximum
T
limit for „, is fixed, and since Tt — Ts is determined by
*s
the power to he transmitted and the belt speed, we have
only to make Tt and Ts large enough so that their ratio
will he within the required limit, and
to (house a helt sufficiently wide and
thick to stand this maximum pull.
Suppose, for example, that it is de-
sired to transmit 100 hp. between two
30-in. cast-iron pulleys, 30 ft. apart
and on the same level, at a belt speed
of 2500 ft. per minute. The resistance
of the driven pulley will be 1320 lb.
at the rim, and this same figure will
represent the excess of Tt over Ts.
Since the an- of contact is 180 deg.,
and p-, according to the experiments tv-
7'
I'crrcd to above, is about 0.3, ,., must
J s
be greater than 2161 lb. and Ts greater
than SI 1 lb. Of course, the excess will
he made as small as possihle in order to
avoid undue pressure on the shaft bear-
ings and an unnecessarily large belt;
hut there must he an actual excess, or the belt -will soon
stretch permanently— so much so that it will he necessary
to shorten it by cutting out a piece, so as to keep it from
slipping. As for the size of helt to he used, the standard
rule of 111 Ih. maximum tension per inch width of double
helt, corresponding to a maximum tension of about 375 lb.
per sq.in., gives us a helt having 5.75 sq.in. sectional area,
which would probably mean a double helt 20 in. wide.
According to F. W. Taylor's recommendations, the max-
imum tension should he only 54 Ih. per inch width of
double helt, if h is desired to have belts which will give
the least expense for repairs and lost time on machinery.
In that case, our calculations show that a 30-in. double
belt or, preferably, a 20-in. quadruple helt must lie used.
oil
P 0 W E K
Vol. 41, No. 16
So much for the design of belting transmissions by
theoretical formulas. On the other side of the question,
our own observation tells us, first, that for transmitting
100 hp. at 2500 ft. per min., very few I'm tones use belts
much over 20 in. wide and % in. thick, and second, thai
such belts, when running between pulleys a considerable
distance apart, will often sag on the loose side anywhere
from one-third to three-quarters of the mean diameter of
the pulleys. Xow we can very easily find the tension at
the two ends of the loose portion of the belt by means of
a little mechanics and the use of the well-known fact that
a licit or rope, when suspended between two points, hangs
approximately in a parabolic curve whose equation is
ir.r-
y = ■>. a
in which
y = Vertical distance of any part of the belt from
the lowest point :
x = Horizontal distance of the same point from the
lowest point ;
w = Weight per unit length, and
M = Tension at the lowest point.
Taking y = 2 ft. and x =15 ft., corresponding to
a point on the loose side of the belt just as it is leaving one
of the pulleys, and assuming the weight of leather as
0.036 lb. per cu.in.. we have, for the 20-in. double belt,
w = 2.47 lb. per ft. and H = 130 lb. At one end of the
span the tension Ts will consist of a horizontal component
equal to 139 lb. and a vertical component equal to the
weight of half the span, or approximately 37 lb. This
gives us Ts = 143.8 lb., which, to say the least, does not
check very well with the minimum value of 841 lb. ob-
tained by theoretical deductions. Even if the heavier belt
were used, according to Taylor's recommendations. »
and H would merelv be doubled, and Ts would then be
288 lb.
In the opinion of the writer this discrepancy is due to
two things — the arc of contact and the coefficient of fric-
Ts
0.00758/10. The arc is increased very materially by a
slight sag in the loose side of the belt, if that side is the
upper one. In our problem a sag of 2 ft. at the middle
of the span means an increase of about 15 deg. in the
arc of contact, and this difference alone is enough to in-
rp
crease the allowable ratio of -^ from 2.57 to 2.78. How-
ever, a much greater change is caused by the second factor.
It is not generally known that the coefficient of friction is
very decidedly increased by slippage between the belt and
pulley surfaces, although this fact seems to have been
recognized many years ago by several investigators of the
practical mechanics of belting. Uhwin gives the equation
u = 0.2 + 0.004 V~T. where V is the belt velocity in
feet per minute, on the assumption that the amount of
si i'ii will increase as the speed of a helt becomes greater.
P.arth. after making a very careful analysis of some tests
carried out by Wilfred Lewis for Wm. Sellers & Co., de-
2
duced the two following equations: ft = 0.6 — j. j_ ~
where v is the velocity of 'slippage of the belt relative to
one of the pulleys, in feet per minute, and in the other
140
tion assumed
the theoretical formula log
The last of these, like Unwin's equation, depends only
on the velocity of the belt, and is supposed to be used for
ordinary bell transmissions where the total slip between
the driving and driven pulleys is about 1% per cent.
Now a slip of 3 per cent, is very common in belting prac-
tice, and for hells that are running at all loose it may
easily reach (i per cent. In such a case, a bell running at
2500 ft. per min. will slip over each pulley with a veloc-
ity of 75 ft. per min., and ,«, according to Earth's first
T
formula. = it. 575. At that rate, the ratio ^-, as figured
T
by the same equation that gave us 7=- = 2.57, may be in-
-1 s
1 reased to 7.1, and Tt and Ts, instead of being, respee-
tively, 2161 lb. and 841 lb., are reduced to 1536 lb. and
216 lb. This value of the tension in the loose side of the
belt lies about half way between the tension which it was
figured would be required to support a 20-in. double belt
with a 2-ft. sag I etween the pulleys, and that required for
a 20-in. quadruple or 40-in. double belt with the same sap.
In other words, a 20-in. triple belt can be used in the
transmission which we have been figuring, and allowed to
sag 2 ft. on the loose side, in spite of the preliminary
calculations which showed that such a heavy initial ten-
sion would be needed that the helt would pass from pul-
ley to pulley in practically straight lines.
The upshot of the whole matter seems to be this: Al-
rp
most any value within reason for the ratio -^- may be
Js
obtained by calculation, simply by juggling with the
coefficient of friction ; it is therefore worse than useless
to use the standard formulas for the design of belt trans-
missions, unless we take into account such factors as the
belt's speed and slip, which are usually neglected. If,
however, we can get a pretty accurate value for the coeffi-
cient of friction, we can figure belt tensions which will
agree quite satisfactorily with those which we observe in
practice. It should be noted that this can be done with-
out in any way taking into account the effects of cen-
trifugal force, which, in the opinion of some, should be
given the entire credit for making it possible to run slack
belts.
sf Hea^Iini^ Feed
= 0.54
500 + V
Wi
By C. E. Andebson
Notwithstanding the economy of using exhaust steam
for heating water for boiler feed and other purposes and
the widespread information on the subject, the writer
is constantly coming in contact with cases where live
steam is used for heating water and for other purposes
where exhaust steam might readily be employed.
Theory and practice prove beyond a doubt that a saving
of 10 to 20 per cent, in coal consumption may be effected
by heating feed water, the amount varying according to
conditions. Where large quantities of hot water are used
for other purposes a much greater saving may be made
by using exhaust instead of live steam to heat it. In
some cases it is more economical to run noncondensing,
but if the exhaust furnished by the pumps and other
auxiliary machinery is nearly enough, it is good practice
to make up the deficiency by bleeding the intermediate
receiver.
April 20, 1915
POWET!
545
The following calculations may be of interest, showing
the value of the feed-water heater. For convenience, as-
sume a heater working continuously at its full capacity
for ten hours a day ami supplied with exhaust steam from
the average noncondensing engine developing about ^~>
hp. Taking water at 60 deg. P., the heater will deliver
about 1200 gal. per hour, or 12,000 gal. per day at about
210 deg. F. One gallon of water weighs about 8% lb.,
and 12.000 gal. will weigh 100,000 lb. Since it requires
150 heat units (B.t.u.) to heal one pound of water from
60 deg. F. to 210 deg. F., 100,000 lb. requires 15,000,000
heat units.
Roughly speaking, one pound (weight) of live steam
will furnish 1000 heat units, therefore. 15,000 lb. of live
steam would be |uired to do the work. Under good
conditions one pound of coal will evaporate 10 lb. of
water. This figure may be exceeded in some instances,
hut probably the majority of cases fall below it. On
this basis no less than 1500 lb. of coal per day will be
required. Assuming a working year of 300 days, this
gives a total of 150,000 lb,, or 225 tons, of coal burned,
which at $4 per ton would cost $900.
This sum represents the saving by the use of a heater
with exhaust steam. Of course, these figures are arbitrary
and the result will be more or less fully realized in
practice, according to circumstances.
The Curnon Steam Meter is nothing more than the fa-
miliar low-pressure recording gage of the diaphragm typo.
and its pressure regulator which utilizes the Bourdon
tube. The meter is sensitive and fairly accurate. The
charts used with the instrument are directly calibrated in
pounds of steam per hour, so that no calculations are nec-
essary to secure the desired data. The installation is sim-
plified by the use of double cocks both on the test plug
and on the meter.
Pig. 1. Cusnon Steam Meter
The principle employed in this meter. Fig. 1, is that of
the l'itot tube, consisting of two small tubes with their
ends bent at right angles and inserted in the pipe in
which the steam is flowing in such manner that the end
of one faces against, and that of the other with, the direc-
tion of flow. The rush of steam past the tuhes causes in
one a slight increase, and in the other a corresponding de-
crease, iii the statii pressure in the pipe. The difference
in pressure is a measure of the velocity of the steam,
and by connecting the two tubes to a sensitive differential
pressure recorder a record is obtained of the quantity of
steam passing through the pipe to which it is attached.
Fig. 2 shows the l'itot tube mounted in the Curnon plug.
The special feature is that the tuhes are of such length
Fio. ■.'. Arrangement of the Pitot Tube
as to reach exactly to the center of the pipe, where the
speed of tin- flow is highest and where eddy currents are
least likely to interfere with the accuracy of the meas-
urements. The low-pressure tube has a long elbow, which
further increases the pressure difference and the motive
power available to secure clear records of small variation
in load. A single three-way cross controls both tubes and
enables steam to be blown through them for cleaning pur-
poses.
Fig.
Metei: without Casing
All of the moving parts are mounted on a cast-iron
base, as shown in Fig. 1. The outside dimensions when
mounted in a box are 15x9x9 in. and the weight is about
fifti pounds. Fig. 1 is a view of the diaphragm box,
which is arranged in the back plate of the meter case.
The two pressures in the test plug act upon the sides of
a sensitive diaphragm, which is stiffened by two plates
and controlled by a strong flat spring. The movements
of the diaphragm are conveyed to the pen through a sys-
tem of levers which multiply and rectify the movement
in such a way that the curves traced upon the paper chart
directly represent the weight of steam passing through
the pipes.
546
vow e i;
Vol. II. No. L6
As the accuracy of the instrument would be affected by
any variation in boiler pressure, each is fitted with an
automatic pressure regulator consisting mainly of a hol-
low spring of the Bourdon type, arranged centrally be-
low the recording drum and linked at its free end to the
multiplying gear. This is shown in Figs. 1 and 3. The
interior of the Bourdon tube is in communication with
the steam pressure in the pipe, and the movement oi
free end so aits upon the pin gear as to automatically
correct the reading for any fluctuation in pressure.
The connection between the meter and the %-in. cop-
per test tube may he any reasonable distance away, either
above or below the pipe.
The double cock, shown in Figs. 1 and :!. at the top,
is constructed so that both ports arc opened and dosed si-
multaneously. In the closed position the meter is con-
nected to the atmosphere and the pen must always stand
at zero on the chart. This enables the operator to check
the adjustments at any time. Between the plug and the
meter are the condenser coils, which consist of %-in.
copper tubing fitted to the plug horizontally and on an
exact level with the Pitot tube in the steam space. The
Fk;.
DlAPHKAGM BOX IX SECTION
condensing coils insure that the meter, as well as the
connecting pipe, is always tilled with comparatively cold
water, regardless of the displacement due to the move-
ment of the diaphragm.
The meter is manufactured by the James Biddle Co..
1211 Arch St.. Philadelphia. Penn. Each one is supplied
with a test book, condenser coil, two 10-ft. copper con-
necting tubes and 100 charts and ink. The standard
charts are calibrated in pounds of steam power and *re
available in various rang - for each size of pipe. The in-
strument is fitted with a "v4-hr. chart and an 8-day clock.
_^©iradi©invs<eip
The illustration shows a pair of 34-in. ejector con-
densers recently installed by the Deane Steam Pump Co.
in the city electric generating plant of Holyoke, Mass.
The apparatus serves a 3500-kw. horizontal double-flow
turbine and maintains 28 to 28% in. of vacuum in the
turbine exhaust chamber.
Lk '
IIF] I
ray
3.-A r1' ^
3aE
^^^EL^. . jmHHI^^^^IH
B^i
A Paib of 34-In. Ejectob Coxdexsers
In the construction a lifting device has been provided
to permit the cone to be raised to discharge any trash
which may stop the annular opening in the condenser
after passing through the -trainer. The tees shown at
the to] i of the condenser are so designed that the cone can
be lifted through the tee in case of desired changes, re-
pairs or alterations. A pointer on the cone-raising spin-
dle indicates the amount of opening around the cone. A
device has also been incorporated to center the cone and
prevent vibration of the lower edge when it is in its work-
ing position. The long run of 50-in. exhaust-steam
riser ami the 16-in. injection pipes arc noticeable. These
are botb made of lap-welded steel tubing. The exhaust-
steam riser is in one piece 25 i't. 8% in. long and the in-
jection risers and the drop pipes are also each in one piece.
Expansion and contraction of the piping under varying
temperatures are taken care of by spring suspensions.
V
Formidable Looking Formulas — Many engineers will go
down without a struggle before a formula which has a
logarithm, entropy or a sine, cosine or tangent in it. It is
just as simple to look up one of these quantities and to sub-
stitute the value given in the table for the letters of the
formula as it is to hunt up the steam temperature corre-
sponding to a given pressure, or the area corresponding to
a given diameter, and the same hook which contains the
tables of the properties of steam and of circumferences and
areas will usually have the other things, too.
April 20, L915 POW E 1! 547
3ii in mi nun ii inn milium milium liimiiii i mi iiiniiu iiiiuiiuuuiiii i imiiiiiiiiii i iiiimi imiiiii iiiiiiiuu iiiiiiiiiiiiuiuuuuiui lining
EdliitoiriisJb
iiniliiiniuiiiiiiinuuniiiiiiiiiiiiiiiuinniHiiiiiiiiiiiiiiniuiiiiiiiiimiiuuiuiu u ; . < u mm "mini, mimiiiniiiiiiiiiiim m i i • : mmiiiiiiiimiiiiiiiiu ■ 1 1 in iiiiiimiiimim IS
There next followed the Srsl real tryout of the tur-
bine on a large scale, when in 1905 about 10,000 kilo-
watts in turbines were run in competition with a nearly
equal capacity of reciprocating engines in the L-Street
station of the Boston Edison Company. The results
of these competitive trials do not need to be told.
Ami all this truly remarkable advance had been made
almost simultaneously with the installation of large re-
ciprocating engines in such stations as the Seventy-
Fourth Street of the [nterborough Rapid Transit Coin
pan;,: Waterside, No. ".'. of the New York Edison Com-
pany, new in 1902; and the Fifty-Ninth Street station
of the [nterborough Rapid Transit Company, new in
1904. This is the most conclusive evidence that the
early development of the turbine was rapid beyond the
expectations of the best engineering talent of the time.
There are lew more I'oivel'ul examples of what the
economy of the large steam turbine means in the gen
erniioii of power than the recent changes in the Seventy-
Fourth Street station of the [nterborough Rapid Transit
Company, New York City, which are described in this
issue. When it pays to discard to the junk pile en-
gines of large power, nearly as good as new, to make
room for turbo-generator units, it shows that designers
have been accomplishing things. And yet, in doing so
they undo their admirable work of but a short time ago.
These great engines should not go into oblivion without
a word being recorded of their life's history, too much
of which has perhaps already been forgotten. The in-
stallation in the Seventy-Fourth Street station in 1901,
beside being one of the most notable, was virtually the
last stand of the large reciprocating engine for electric
generating units.
They were designed by that Connecticut farmer boy,
Edwin Reynolds, who became one of the eminent figures
in the steam-engineering history of the country. It is
told that Mr. Reynolds was invited to New York to
discuss with the Manhattan Railway Company's engi-
neers the subject of selecting the type of engine for the
Seventy-Fourth Street station. When he left the E. P.
All is works in Milwaukee, the question was unsettled.
At Albany a telegram informed him that a committee
representing the railway company would meet him at the
Grand Central station. When he reached Harlem, the
story goes, he had sketched on the back of a letter the
design ultimately adopted, the sizes of cylinders and prin-
cipal parts being indicated. And the problem was to
crowd 12,000 horsepower in each engine, which had to
go in a limited space.
It seems that Fate had decided that this daring stroke
should he about the last, for the turbine was beginning
to demonstrate its possibilities. The first important in-
stallation was in 1899, when some 400-kilowatt machines
were put in the plant of the Westinghouse Air Brake
Company. About a year later attention here and abroad
was centered in the two 2000-kilowatt units of the Elec-
tric Light & Power Company. Hartford, Conn. This
was the most notable installation in point of capacity
and because the expansion was completed in one cylinder.
Then came the announcement that several 5000-kilo-
watt units were being built for the combined station
of the Metropolitan and District roads. London.
The fact was being established thai the larger the
capacity of the turbine the re favorable was its per-
formance, and 1905 saw contracts closed for a 10,000-
kilowatt Brown-Boveri-Parsons machine for the West-
phalian Electricity Works, Essen, Germany. At this
time the Brooklyn Heights Railroad Company got two
'. 500-kilowatt units, which were then the largest tur-
bines in this country.
©sua asa
SttgxaliKDim ©©sn^na
If power-plant designers generally were experienced in
station operation, more consideration would be given to
adequate space for equipment and attendance. The tern | >
tation to cut down on space is great, to save in the
amount of material required to inclose the plant and in
the fixed charges per horsepower of capacity. This con-
sideration limits stations built in country districts as well
as those on valuable city land, and the operating stall
frequently finds itself lacking in room.
Some of the difficulties of attempting to operate in a
cramped location may well be considered as an offset to
the demands of an initial layout extremely economical
in structural material. The importance of adequate
clearance will be conceded by any student of "safety first."
Where bare c luetors are to carry high voltage, the
designer generally appreciates the element of clearance.
It is fully as important in many low-voltage plants to
provide adequate spacing between conductors and metal
work ami between lines and horizontal or vertical pas-
sages. The commercial value of the loads carried, even
if there were no personal hazard in the crowding of live
c luetors into restricted spaces, often makes it inad-
visable to take chances of interruptions. Tt should never
be possible lor an engineer, climbing an iron ladder and
momentarily losing bis grip, to swing outward so far
as to touch the exposed contacts of an instrument trans-
former. Designers who will properly separate circuits
carrying high voltages sometimes neglect to spend enough
] icy on low-tension bus structures and switch cells
to protect the service and the operator from mischances.
A thorough investigation of the relation between the
labor cost of station service and the space requirements
of the plants covered would be of much interest. Equip
mcnl arrangement is important, but accessibility and
freedom to reach apparatus without traversing circuitous
paths are also. Main units are rarely so crowded to-
day in new stations as to hamper removing sections of
548
P (MY E R
v !. H, No. 16
machinery, but in the placing of auxiliaries and in
the arrangement of piping, valves and platforms, much
en to !»' desired. A construction engineer who rose
to a high place in a consulting organization recently re-
marked that few things in his early experience had
proved of greater value than several months of service
as a substation operator after the close of each day's
work in the drafting department. The actual handling
of the equipment gave him a knowled ice re-
quirements that was reflected in his later work, lie
knew what room the switchboard operator needed to
manipulate manually connected switch levers in criti-
cal moments: he appreciated the desirability of being
aide to read instruments easily from all apparatus-con-
trolling points; and he realized the handicap of crowded
motor-generator set- and transformers closely adjacent to
railings or too near aisles for rapid movement.
In order to get the benefit of the reduced labor cost
per kilowatt of capacity of modern generating unit-,
i i- worth while to make sure that subordinate equipment
i- sufficiently separated to enable it to be operated and
maintained without adding needlessly to the station
payroll through the comparative inaccessibility or ob-
structive features of the apparatus and its arrangement.
Ample space in which to use tools specially adapted to
the adjustment of complex machinery and fittings is of
enough value to justify, usually, at least a moderate in-
crease in building cost. In other words, flexibility and
compactness are not always synonymous in first-class
designing.
'Uiairesvsoixass.lbll© ILaces&s® ILaws
Nobody would deny that it is the duty of the state
to see that boilers are safe and that they are safely
operated.
If a factory inspector makes you provide fire escapes
and put guards around gears and belts, if a plumbing
inspector insists that the plumbing, even of your dwell-
ing, shall be sanitarily installed, if the fire and insurance
authorities can dictate how much combustible or ex-
plosive material you can have around and how you must
keep it. sureh somebody should pass upon the adequacy
of steam boilers, to the consequences of the failure of
which not only industrial workers, but occupants of office
buildings, customers of department -tore-, guest- of hotels.
and even the pedestrian upon the street, are subjected.
Nobody would deny that the state — which is the
people — should provide for the safety of the people by
the inspection of these boilers and of the man who runs
them — if that were all that there is of it.
The man who owns boilers and hires men to run them
is afraid that this will not be all.
When he sees laws passed, denying to a man the
privilege of working at his vocation because he was not
born am! brought up in the town where the job is —
When he sees rule- adopted, denying to an engineer
coming into a community, be he the best engineer in the
world, anything except a chance to work in a subordinate
capacity, with the lowest grade of license —
When he sees examiners acting in collusion with organ-
ized labor, to keep down the supply of engineers by re-
fusing men licenses to nan -team plants because they
cannot design triple-expansion engines —
When he sees engineers' organizations straining the
interpretation of existing laws so as to require every
laborer about a steam plant to lie a licensed man —
He i- afraid that the legislation, however be)
in its declared purpose, however innocent in its seeming
intent, i- of sinister design and hostile to his interests.
Mosl of the opposition to the passage of eng
license law - i< inspired by this fear. Most of the difficulties
experienced by the A. S. M. E. committee appointed to
formulate standard specifications for the construction of
steam boilers and other pressure vessels and for the care
of the same in service came because ii included in it-
report a recommended form of license law. As one
member put it. ""this committee, appointed to get up a
blueprint of a horizontal return-tubular boiler, tried to
involve the society in objectionable legislation." The only
way that the report could be gotten through at all was
by leaving out all reference to legislation and all sug-
gestions for laws which would bring about the adoption
of the Code by the various states.
As we started in by saying, nobody has any tenable
objection to the adoption of boiler inspection and engin-
eers' examination laws, when he is satisfied that they are
not excuses to add to the difficulties of the employer and
subterfuges to obtain unnatural and unfair advantages for
the present holders of jobs in power plants under a
specious anxiety for the public safety.
The real effort for such laws is sincere and honest, and
those who are making it should most forcibly disavow
any ulterior purpose in their agitation and frame their
1 legislation so that it cannot be abused.
It is Imped that the American Society of Mechanical
Engineers' Code, above referred to, will come into
universal use in this country. Its adoption by the various
states, for which powerful interests are striving, opens
the way to. if it does not go hand in hand with, the
examination and licensing of engineers. Those who are
seeking legislation to bring this about should unite their
■efforts with those who are striving for the boiler-inspection
laws and make their demand so reasonable and so sensible
that they cannot reasonably be denied.
EDffeett of 3HIIg°lh §&©.minfii PiresstiSff'®
In the days when seventy pounds was so usual a steam
pressure that it was taken b. the committee on boiler
trials of the Centennial Exposition as representing aver-
age practice, such an occurrence as a flywheel explosion
was almost unheard of. The maximum mean effective
pressure which could possibly be gotten was that which
would result from carrying seventy pounds full stroke.
With an initial pressure of one hundred and fifty pounds,
the attainable mean effective pressure in case something
goes wrong with the governor is more than twice as great.
Tin- means that the velocity generated in a given time
would be more than twice as great : but since the centrifu-
gal force increases as the square of the velocity, the stress
generated in the flywheel in a given time would be over
four times as great. An accident which prompt action,
under the less strenuous conditions id' twoscore year- ago,
would have headed off. would be likely to be all over
now before the attendant could gather hi- wit- get into
motion, and close the throttle.
April 30, 1915 POWER 549
aiuiiiiiii iiiiiiiiiiiiiiiniiiiiiiiiiiin iiiiiiiiiiiiiiiiiiiiiiiiiinii Minn nniiiii inn miiiiiiiiiii mi .' iiimiiiiiiiiiiiii iiiiiiiiiiiiiiiuniiiimiiiiiiiiimuiiniiiiiiiiiiiiiiiimii i;n iiiiimiimmiuimiiiiiiiiiiiiiiii i iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiunn
C©o?esp©inidleinic<
Rsifte Dascirisrmlifi\avttii<o>Ea aim
Maassandhmasefitis
In the Feb. 23 issue there appeared an item dealing
with the attempt of the New England Power League to
gel .'i bill through the Massachusetts Legislature tending
to make more equitable the rates Eor electricity. Perhaps
it would be interesting to your readers to learn more as
to why the League takes tins attitude.
The schedule of the Boston Edison Co. appears to be
the only one which is susceptible of having curves plotted
which mean anything; but the conditions existing in must
of the other electric companies in the state are the same
as shown by the curves of the Edison company. There is
no difference, so far as results are concerned, between a
charge for the privilege of being connected to the lines
plus a charge for the power delivered, and charging a
high price to the small consumer and a low price to the
large consumer. Twelve cents a kilowatt-hour to a small
consumer and one cent to the large one represent the
range in power costs in Massachusetts. This applies to
both demand plus a current charge and a straight charge.
To illustrate the Boston Edison schedule, Fig. 1 lias
been drawn, which shows that from 0 to 15 kw. there
is a demand charge of $60 per kilowatt per year. From 15
kw. upward, this demand charge decreases, and at 10,000
JOO 500 400
Kilowatt Demand
Fig. 1. 1 'km \\n ( 'harges
kw. demand is $15. 152 per year. This applies to perma-
nent rates, that is, to those who make a permanent contract
for more than one year. If the contrad is only for a year,
the reduction is not so great ; but even under these condi-
tions, at 500 kw. the demand charge is only $31.20.
Capitalizing these charges, the lower curve is obtained,
which would indicate that from 0 to 15 kw., the cost per
kilowatt of demand is $428; whereas at 10,000 kw. it is
only $109.70. This in itself is rank discrimination, be-
cause it is impossible that a city plant could he built with
the necessary distributing lines at $10!). TO per kilowatt.
It is even worse than it appears on the surface, because of
the diversity factor.
It has been proved by one of the largest companies thai
the diversity factor of the large load is practically unity,
whereas that of the small load ranges between 3 and I.
that is. a large consumer will usually require in the powi r
Kilowatt-Hours Used per Month (Thousands)
Pig. '.'. Prices for Energy Used
plant a capacity equal to his maximum demand, whereas
the small consumer will require an installation in the
power plant equivalent to only one-third or one-quarter
of his maximum demand. As the large consumer is
charged for a value less than one-third of the actual cost
of the apparatus, the small one on the other hand is
charged at a value of three to four times those shown on
the capitalized demand costs, or from. $1282 to $1712
per kilowatt of actual station capacity.
These figures alone are sufficient to make the New
England Power League and others feel that it is time
some laws were passed which would make an equitable
division of the power costs.
Another item of discrimination is the division between
yearly and permanent contracts. It will be noted from
Pig. 1 that from 15 to 155 kw., yearly and permanent
contracts are the same, but that above 155 kw. there is a
decided difference. To my mind this is discrimination.
because there should be no point at which these two
contracts should be the same if there is any reason for a
division between the two characters of contract. If it
costs more to handle yearly customers than it does perma-
nent ones, it will cost more for any character of load.
So far attention has been called only to the demand,
and it will lie noted that there is a wide variation in de-
mand charges. Let us look now at the energy used.
Fig. 2 shows the variation in these charges for various
consumptions in kilowatt-hours pel- month. It will be
noted that here again there is a marked decrease in cost
solely for an increase in the amount of current used. It
would seem that if there were a large difference in the
cost for the demand, there should be a uniform price for
the current, for certainly the demand charges as laid out
i over much more than the fixed charges on the small load.
and do not cover nearly as much as the fixed charges on
the large load. Therefore, In order to even matters up.
it would seem as though tic powei' charges for current
o50
POWK 1;
Vol. 11, Uo. L6
delivered should be uniform. They are not, and again the
small consumer gets the worst of it. Up to 1500 kw.-hr.,
he has to pay 5c. per kw.-hr. From this point on, the
rate decreases to a marked extent, until at 55,500 kw.-hr.
the price is under 2c. for permanent rates. For yearly
rates, however, the price is approximately 2.6c. Eere again
there is a division between the yearly and the permanent
rates. \s has been stated before, if there is any reason for
a division, it should apply to all characters of load ; but it
does not. The division take- place at .VMM) kw.-hr. per
month.
In my opinion there is no question as to the injustice
and discriminatory feature of the demand charge as out-
lined, as well as the current charge; and I am heartily
in favor of any attempt which may be made to bring
about a more uniform and jus! arrangement of charge
for electric light and power.
Henhi D. Jackson.
Boston, J I ass.
Pffisimlimg ©. CeE&thraiFvDiflgvE Puasimp
This is a problem which confronts many operators of
centrifugal pumps. In the Mar. 2 issue there is an article
on this subject by J. F. Jones, in which he describes the
trouble he had in priming a 30-in. pump. While his
method is all right, it does not exhaust all of the air from
inside the casing, and no doubt there is considerable
"rumbling" in the pump while it is in operation, with a
possible chance of injuring the impeller. By referring to
Fig. 2 of Mr. Jones' article, it will he seen that it is impos-
sible to remove all the air from inside of that part of the
casing which is above the point where the ejector suction
enters the suction elbow on the pump. By running
with air entrapped inside the casing, the delivery is no
doubt reduced. '
When a pump such as that shown by Mr. Jones is
started with air inside the casing, it is difficult to get rid
of all of it through the discharge pipe. What might be a
more satisfactory way to prime this pump would be to
connect the ejector as shown in Fig. 2 of Mr. Jones' arti-
STEAM EJECTOR
RELIEF VALVE
Positions of Ejectoe and Belief Valve
cle, except that the suction should be cross-connected to
the top of the casing. The method of starting would lie
the same as that adopted by Mr. Jones, except that after
the pump is running and before stopping the ejector, the
hitter's suction to the top of the pump should be opened
and that to the elbow closed. This will exhaust the air
from the top of the casing. In this way the delivery
should be better than it' there were some air in the casing.
It is not always best to leave off the flap valve, and it is
often necessary to have one on the end of the discharge
pipe. When a flap valve is used it is necessary when
shutting down, to have some way of breaking the vacuum
in the discharge pipe which is due to the water running
back down the pipe and through the pump.
The possibility of collapsing the discharge pipe on a
pump such as that de-
scribed by Air. Jones,
can be avoided by
placing a relief valve
near the flap valve on
the discharge pipe.
The position of this
relief valve is shown
in Fig. 1. It should
be placed on the high-
est point of the dis-
charge pipe.
A suitable relief
valve can be made as
shown in Fig. 2. The
spring for holding the
v a 1 v e on its seat
should be of such
strength as to allow
the valve to open when
a vacuum of about 20
in. of mercury is pro-
duced inside the dis-
charge pipe. Th e
opening will permit
air to enter, thus breaking the vacuum and preventing
the possibility of collapsing the discharge pipe. An or-
dinary rubber pump valve ami seat are shown as making
up this relief valve. A gate valve should be placed as
shown. This is left open while the pump is running, and
it fni- any reason the pump should stop and the flap valve
close, the relief valve would open automatically when the
vacuum inside the discharge pipe became great enough
to overcome the pressure of the spring..
J. E. Poche.
Xew Orleans, La.
Fig. 2. Belief Valve
In the issue of Mar. 16, Mr. Seed has an interesting ar-
ticle showing the reasons for different rates and using
the cutting and delivery of ice as an illustration.
In his figures it appears that the cost of labor decr<
much too rapidly in the handling of the various quantities
of ice; also the investment cost. It is hard to conceive
that the investment will decrease from $1.50 a ton to ! 5 .
with an increase of four times the amount handled. It
costs more to add a story to an icehouse than just the la-
bor and material. Furthermore, the reduction in price-
to the various large consumers is not as great as will prob-
ably take place in actual conditions, and nothing like as
great as in electric sales, where the ratio of the small
to the very large consumers' rate is often 10 to 1. and
the small consumers' rate to the average, about (i to 1. Mr.
Seed's greatest variation is 4 to 1, when the largest con-
sumer has no delivery cost at all.
In answering his question, "If Jones found it neces-
April 20, 1915
I ' ( > W E K
551
saiy to give up a part of his business and had his eh
which part would he drop?" it all depends od the figures.
If he sold two tons at $8 per ton, and they cost delivered
$12.30, there would be a gross profit of $3.70. [f I
the next three tons at $4 a ton and they cost him $13.45,
he would have a loss of $1.45. If he sold five tons at $2.50
a ton and they cost him $15.75, he would have a loss of
$3.25. If he sold ten tons at $1 and they cost him $1 1 .50,
he would have a loss of $1.50. Under these conditions
which would he choose? These figures correspond more
closely with actual electric prices, as is shown by the fol-
lowing table. One if the large companies sold power
as follows :
Kilowatt-Hours Receipts Cost
Motor service 25,471,000 $1,114,624 $743,000
Street railway S, 319, 000 142, 9S7 242. 2<m>
Street lights 17,739,000 781,792 516,500
Commercial liuhtine, sn.all 24,56s, 2.457. •.15, nun
Commercial lighting, large 42.495,000 1,792,000 1,240,000
Other companies.... 4,248,000 121,530 123,700
These costs, like those shown in Mr. Seed's illustra-
tion, are the average operating costs of the plant and do
not take into account interest or depreciation. If the
company had to choose which class of customer it would
drop, which would seem the more probable — the small one,
paying 10c, or the large one paying considerably less?
I realize that the figures given here do not recognize
many differences in expense to the various characters of
load, the cost being the average as shown by the Public
Service Commission's report. At the same time, I be-
lieve that this illustration shows the absolute futility of
trying to compare the manufacture and sale of electricity
with ice.
Electricity must be sold as it is manufactured, because
it is not possible to store it commercially. This being
the case, if we have a customer or group of customers
who will demand a certain definite load all day, giving
unity power factor, the investment is used to its maxi-
mum and therefore the price of the power should: be low.
If, however, another customer comes along who requires
power for only a short period, an additional investment
is compelled; and as the power is used but a short time,
the investment is used but a short time and the fixed
charges are high; and also, as the machinery is used but
a short time, the labor charges arc large, which means in-
creased cost. This latter is to all intents and purposes the
condition which exists with the large power users. Dur-
ing the summer they can be run very largely from the
plant which is installed to handle the lighting load: but
during the winter they cannot, and apparatus which is
idle during the rest of the year has to be put into the plant
to meet the power load. This being the case, the invest-
ment charges against these power users are very large.
This will counterbalance any inaccuracy of the figures
given above when taken in the sense of neglecting the in-
terest and depreciation charges; they are comparable and
accurate if these charges are taken into account.
Henry. I). Jackson.
Boston, Mass.
That all do not reach the same conclusion from the
same starling point is well illustrated in the letter of
Mr. Seed on page 383. Using the same figures given,
if Jones supplied only one of the classes of customers
and could take his pick it wound be as follows;
To consumers taking 50 to H|i) lb.:
Two tons at $S per ton $16.00
Cost of two tons r.t $2.50 $5.00
Cost of team 5.00
Cost of two men . 3.00
15.00
Gross profit $1.00
Profit per ton, $0 50
To markets, etc., 200 to 500 lb. per delivery:
Three tons at $6 per ton $18.00
Cost of three tons at $2.50 $7.50
of team 5.00
Cost of men 5.00
Gross profit $0.50
Profit per ton, $0,163-
For ice-cream factories, etc., 1000 to 2000 lb.:
Five tons at $4 per ton $20. Oil
Cosi of five tons at $2.50 $12.50
Cost of team
Cost of two men 5.00
22.51
Gross loss $2.50
Loss per ton, $0.50.
To Smith & Brown, 10 tons at icehouse:
Ten tons at $2 per ton $20.00
Cost of ten tons at $2.50 25.00
Gross loss $5 00
Loss per ton, $0.50.
It is seen that the small consumer is the only
who pays much profit alone. Whom would .Tones serve if
lie could get only one class?
Using the figures exactly as Mr. Seed gives them and
supplying all classes, the profit per ton is
Small consumer 2 tons, pro.'.* ',3.70, per ton $1.S5
Markets, etc 3 tons, profit 4.55, per ton 1.511
Ice-ci earn factories 5 tons, profit 4.25. per ton 0.85
Smith & Brown 10 tons, profit 8.50, per ton 0.S5
Jones will sell more ice to small consumers than to
the other classes, and if he could only sell 1000 tons
it is easily seen to which class he would prefer to sell.
I still fail to see why the large consumer should get
all the benefit of cheaper production or pay so much less
profit per unit.
Harry D. Everett.
Washington, I). C.
Tesftiinii^ Si
In the Mar. 16 issue M. R. Blish makes two mistake- in
defining the method of computing the head on a centrifu-
gal pump. On page :!T2 he states that the total head i
the sum of "the suction head, pressure head, and the ver-
tical distance between the center of the pressure gage and
the point of attachment of the mercury gage." The first
error is the omission of a velocity-head correction. It
is quite common for the suction pipe on a centrifugal
pump to be a size larger than the discharge pipe, in which
event we should have to include the difference between
the velocity heads in the suction and discharge piping
at the points where the ^;{^v< are attached. This ma
proved in various ways, but may readily be seen if we
but realize that it requires power to increase the kinetic
energy of the water as well as to increase its pressure.
Only where the two pipes are of the same diameter, so
that the velocity-head correction is zero, would Mr.
Blish's definition apply.
The second error is that here, as well a- on page 371,
he implies that the indication of the mercury manometer
is the value of the pressure at the point of its attach-
ment to the suction gage. It is well known that .n
igi reads the pressure found within it-elf and that
552
P 0 W E R
Vol. 41. No. If.
its height must be considered in finding the value of the
pressure at the point of attachment. The same is true of
a suction gage. If the suction head is read by means of a
vacuum gage, the definition of total head should be cor-
rected to read, and the vertical distance between the cen-
ters of tlir pressure and vacuum gages. If the suction
head is read by a mercury manometer, the point corre-
sponding to the center of the vacuum gage will be the top
of the mercury column on the side of the CT-tube that
is connected to the pump.
The words in italics are based upon the assumption that
there is a continuous column of water between the vacuum
gage or the mercury manometer and the point of attach-
ment to the suction pipe. Such a condition may be real-
ized if the connecting tubing be filled with water before
the pump is started and if the point of attachment is not
,u a place where a pocket of air may accumulate. If
the connecting tubing contains air only, then Mr. Blish's
method of computation would be correct. This is be-
eause the weight of the column of air between the mercury
manometer and the suction pipe is negligible and hence
the manometer reading would be the value of the pressure
at the point of attachment. In order to maintain this
condition, however, it is necessary to have some means of
permitting air to be drawn into the connecting tubing
during a test, allowing water that has accumulated to be
drawn back into the suction pipe. The figure shown in the
article does not indicate any such provision. Unless one
does have some means of admitting a small quantity of air
during the test, it is better to fill the connecting tubing
with water. Otherwise, if the tubing contains water and
air both, it will be difficult to properly compute the true
suction pressure. In the case of a pump delivering water
under a high head and where the vertical distance from
the suction -age to the suction pipe is small, the error in-
troduced may be negligible, but under other circumstances
it might be appreciable.
Objection must also be raised to the arrangement of
suction piping shown in Fig. 3, on page 371. It is a fun-
damental principle that a suction pipe must contain no
summits, otherwise air will accumulate and finally inter-
fere with the flow of water or cause it to cease.
Mr. Blish seems to have the impression that the inser-
tion of bafflles in a weir box is to "prevent a serious veloc-
ity of approach."' Baffles are used to quiet the water and
cause it to flow uniformly, but have no effect upon the
velocity of approach. The latter is determined solely by
the dimensions of the cross-section of the box.
In connection with measuring the rate of discharge of
the pump, the author might have mentioned the most com-
mon method used in testing, which is by means of a cali-
brated nozzle on the end of the pipe. Also the venturi
meter is a valuable device for such purposes.
In starting a centrifugal pump, the author states that
after priming, "open the throttle valve in the delivery
pipe and start the motor." While this may be permissible
with proper starting device- at the motor, a better proced-
ure would be to bring the pump up to speed before opening
the discharge valve. In that way a smaller load would lie
thrown on the motor at starting, since the horsepower with
the valve closed is about one-third that required with the
valve wide open.
The efficiency curves shown in Kg. ', tor speeds of 1200,
1400 and 1G5U r.p.m. are consistent with one another.
but the curve for a speed of 1700 r.p.m. is somewhat doubt-
ful. When there is an increase in the maximum efficiency
of only about 3 per cent, for a range of speed from 1200
to 1650, it is hardly likely that there will be a drop of
about 8 per cent, in passing from 1650 to 1700 r.p.m.
Further, it will be noted that the maximum efficiency at
each speed is attained at greater values of the rate of
disc-barge as the speed increases for the first three speeds,
but for 1700 r.p.m. the maximum efficiency is shown as
occurring at a smaller rate of discharge than at 1(550
r.p.m. This ;> hardly reasonable ami makes one suspicious
of the accuracy of the test data used.
R. L. Davgherty.
Ithaca. X. Y.
RepsiSs'iEag Corliss Vsvlve IBoiraEtietl
One of tlie admission-valve -terns and bonnet bearings
on a Corliss engine got overheated from running dry, until
it gripped and broke tlie bonnet, as shown, A good repair
job was done by boring out the bonnet and making a
Break
\J/ff\
Valve Boxxet with Bushing
sleeve, or bushing, a driving fit. After forcing it into
the bonnet it was turned down and bored out to fit the
valve stem.
When the parts were reassembled very little adjustment
was needed to set the valve to the builder's marks. The
job was done in four hours by two men.
Jul in" Powers.
Xew Bedford, Mas>.
Fuaft^flinig ILiimeirs lira wittlh Eeys
When a key is too loose and it is necessary to put a
liuer in with it. there is sometimes difficulty in getting
the liner to go in with the key, or if the liner is put in
first, to get it to stay in place while the key is being
driven. To overcome the foregoing. I saw the end of the
key, as shown, and insert the end of the liner, doubled
Slot in Key for Liner
if necessary, and bend it back along one face of the key.
Whether the liner should be placed on the oue face or the
other depends on the depth and relative smoothness of
the keyways.
I'll u;l.i:s Berman.
New York City.
April 20, 1915
POWE R
553
Referring to the subject of the letter by A. (i. Solomon,
page 111, -Mar. 23, this difficulty seems to be quite
common. Three years ago I had some trouble with a
small ammonia-compressor cylinder held in place by
eight %-in. capscrews. The screws would become loose
and the cylinder would slip on the bedplate at each
stroke.
1 overcame the trouble in a way similar to that de-
scribed by Mr. Solomon, but more simple. I drilled a
:'riii. hole 2 in. deep at the joint of the cylinder flange
and the frame, then fitted a dowel pin and drove it in
tight. Since then there has been no difficulty in keep-
ing the cylinder rigid.
L. M. Johnson.
Emsworth, Penn.
Tn the issue of Mar. '33. page II I. 1 notice an account
of a method used to prevent the breaking of the capscrews
used to secure the cylinder of an ammonia compressor to
the base.
Xo doubt, putting in tight-fitting keys would prevent
breaking more bolts, but if this means were used on a
steam cylinder, I am afraid that before a great while the
base would lie broken, unless some provision were made
for the expansion and contraction of the cylinder, which
apparently was not done in the case of the ammonia cyl-
inder.
To fit bolts snugly into the holes is wrong, in my opin-
ion, for the cylinder is heated and expands, while the base
remains practically cool and expands very little, thereby
putting a shearing stress on the bolts. If the bolt holes
had been elongated about Vx in., I believe the trouble
would have been overcome without the expense of putting
in the keys. I would advise using only one key in any
case, and enlarging the holes in the other end to allow for
expansion, as stated.
H. S. Mellen.
Philadelphia, Penn.
Ga^s I£xqpE©sii©ir&§ nm IB©!!!©!?
T would like to bring to your attention a recent acci-
dent in one of our boiler rooms, with the suggestion that
it be published, and commented on by readers.
The boilers were of the vertical water-tube type, pro-
vided with two sets of fire-doors with automatic stokers
(underfeed) between them. Forced draft for all the boil-
ers was furnished by an automatically regulated engine-
driven blower, supplemented by natural draft from the
stack.
Owing to some minor troubles it had been necessary to
cut out one of the two boilers in operation the night
before the accident and it, together with the third boiler,
had both the natural and the forced draft cut off by the
dampers, leaving only one boiler in service to carry the
load. This was being forced, with the stack damper wide
open, the blower running at full capacity and the stoker
rapidly feeding coal. The fireman in cleaning the fire
(with only one fire-door open ) found a clinker had formed
over the tuyeres. As he loosened this an explosion oc-
curred in the firebox, precipitating him backward against
the coal bunker and burning him severely. The engi-
neer, who was standing directly in front of the other lire-
door of the same boiler, was not injured, as the safety
latches on the latter (which had been installed after two
similar occurrences of a minor nature) prevented its open-
ing, thus justifying their adoption. But the (leaning-out
door at the base of the stack was blown open by the force
of the explosion, which appears to have been considerable.
Presumably, this was a carbon-monoxide explosion facili-
tated by the sudden inflow of air through the tuyeres when
the latter were cleared. The lower limit of the explosive
range of carbon monoxide in air is in the neighborhood of
1"> per cent., and it is difficult to understand how such a
rich mixture as this could have remained in the firebox
with one fire-door open and the stack draft in operation.
We might add that all ashpit doors were sealed and that
it is the practice at this works to keep all stack dampers
wide open on boilers which have fires under them. When
it is necessary to cut out a boiler the forced draft is shut
oil', and as soon as the lire is dead the damper is closed.
We referred a description of this accident to three
prominent companies, one of them supplying forced-draft
equipment with turbine blowers, one supplying forced-
draft equipment with steam blowers, and the third a well-
known boiler insurance company: also calling their atten-
tion to a letter in Power of Mar. 18. 1913, on a carbon-
monoxide explosion. Their comments are in part as fol-
lows:
First Letter —
We never had any experience of this sort, nor have we
ever heard of any with the exception of one case in the
writer's early experience with forced draft.
The power plant consisted of six water-tube boilers with
which, on account of poor draft, it was difficult at times to
keep up steam pressure. The ashpit doors had been removed.
The writer recommended forced draft and made a test on one
boiler with a turbine blower which was very noisy. To reduce
the noise we decided to build a duct around the blower and
run it up to within 10 ft. of the boiler-house roof, but as we
were not sure that this would give the desired results, we
built it of wood and had it lined with shoddy and used card-
board to keep it in place.
During the night the fireman was not able to keep down
the steam pressure even with all dampers closed, something
which had never happened before, and he closed the ashpit
doors of the one boiler which was equipped with the blower,
and no doubt also opened the fire-doors of all the boilers.
After a while there was an explosion, and the duct caught
fire and also set fire to the roof of the boiler room. The
writer's explanation of this explosion was as follows: The
ashpit doors were closed and the fire-doors open. The
damper of the boiler was closed. The duct acted as a chim-
ney and the air went through the fuel bed, caused the forma-
tion of carbon monoxide, which went into the ashpit through
the blower and up the duct. This heated up the duct, and
through leaks around the blower enough air got into the
duct to mix with the carbon monoxide and cause the explo-
sion. This experience and other trouble with this particular
blower were among the causes that led to the inception of
our present type of blower.
We have in the neighborhood of a thousand installations
and, as stated before, we have never had trouble on account
of carbon monoxide, though many of our installations are
operated automatically, so that when the steam pressure
goes up both the blower and the damper close and finally
shut down completely. Many other forced-draft systems are
operated in the same manner.
The letter to "Power" to which you refer is quite interest-
ing, and the only explanation that the writer can give for such
an occurrence is that a steam-jel blower was used. This type
of blower is small in diameter and the air goes through at a
high velocity, and consequently, when shut down little air
goes through it by the draft of the chimney. No doubt the
damper was also closed, and perhaps just prior to the blower
being shut down there was a high rate of combustion and a
high temperature of the fuel bed. On account of all this the
combustion continued, but not enough air being present, it
was incomplete, and carbon monoxide was produced.
With a turbine blower conditions are different. When it
is shut down there is enough air going through the fan casing
:,.-,!
POWER
Vol. ll. No. 16
through natural draft to cause complete combus ion pro
the dimper is not entirely closed. We do not recommend
stopping the blower, but we have never thought of the car-
bo, -monoxide danger, but simply do not recommend it on
account of believing it desirable to change as little as poss.ble
the temperature of the fuel bed. In other words, we recom-
mend That the blowers be run at the slowest rate for the
ightest load and be speeded up when the load mcreases.
We do not think it possible that a high percentage of
carbon monoxide can be reached with the dampers open and
the fire-doors and ashpit doors closed, and we do not think
possible even with the damper closed provided the flower is
not being run at full speed at one tune and shut down com-
pletely afterward. It should be run at as near as possible
the same speed all the time, this speed of course depending
upon the variation in demand for steam. We have never con-
side red it unsafe to automatically close off the blower when
the boiler pressure reaches a certain point, though as stated
before, we do not recommend it. But in view of the two ex-
periences mentioned in your letter we would not now consider
it safe to shut the blower completely and the damper at the
same time when the temperature of the fire is high. I : the
damper is open there will be no danger when the blower s
stopped provided the blower is large enough so tha. the air
can pass through it by natural draft.
Second Letter —
We have vour favor referring to the explosion in a boiler
at one of vour works. We have heard of this occurring. The
case we have in mind was one in which the damper in the
stack or main breeching was closed at the time the explosion
took place. We can readily conceive of such a condition, that
is damper closed and gases being given off by the coal w ith
insufficient air supply, with the result that a large volume o
CO forms Then when more air is admitted, although the
blower is started, it may be possible for an explosion to occur
from the higher temperature resulting with a renewal of com-
bustion, particularly if the stack damper is closed and the
gases confined.
Apparently, in your case the damper was open, since jou
point out that the clean-out door in the base of the stack was
forced open by the explosion. This would appear to indicate
that your stack was small and that the suction was insuffi-
C'e Such explosions are much more likely to occur in the com-
bustion of soft than of hard coal, on account of the presence
of the hydrocarbon gases, which are so much more volatile^
We are not inclined to believe that so high a percentage of
CO can be formed with the damper open, even though both
the ash- and fire-doors be closed. _
With regard to operation, the method we recommend is
the automatic action of the main blower line by means of a
balanced valve and automatic regulator, with a bypass around
the former so as to keep the blowers going continuously the
regulator taking care of the slight fluctuations in the oad.
If the load is extremely variable, then it may be possible to
install a balanced valve in the bypass where the throttle
valve is, this balanced valve being controlled by another
regulator to shut off at a point, say 3 lb. higher than the
first regulator If, on the other hand, the periods of high
and of low loads are known and are not too frequent, then
this condition can be best corrected by opening, more or less,
the throttle valve in the bypass to the balanced valve in the
blower line.
Third Letter-
In the Las! comment it is evident that the writer o
I,,,,!,,,! the points that the opening of the fire-door
e the lire and that if the clean-out
door u, the ha-' ol the stack w blown ..pen. the damper
must necessarily have been open— as was actually the case,
is n-r the amount of CO necessary for explosion, Von
Schwartz, in -Fire ami Explosion Risks," cites Professor
Bunte, of Carlsruhe, as authority lor 16.6 per cent, and
; 1 s per rent, as the lower and upper limits of the amount
of CO in admixture with air which will permit explosion
when ignited by an electric spark, at the same time stat-
in..- that the explosion of such can lie prevented by the ad-
dition of ;i:, to 10 per cent. C02. Von Schwartz also g
the approximate figure's of 13 to 75 per cent, for ignition
by flame and 636 to si 1 deg. C. as the temperature at
which pure CO will explode without air.
From a preventive standpoint the comments quoted do
not give much information, and we are at a loss to know
how' "to guard against explosions of this character with
this particular installation. We have experienced dust ex-
plosions from the loosening of deposits of soot m the flues,
oil-gas explosions with oil-fired systems, earbon-monoxide
explosions from negligence in completely closing stack
dampers ami also severe accidents from flarebacks from
boilers equipped with steam-hlower systems— the latter
caused by too high -team pressure or by tiring the coal too
far back in the furnace, where it obstructed the draft. For
all these there seem to have been reasonable remedies, hut
for a case such as that mentioned we see no cure other
than instructions to keep the tuyere openings clear "1
clinkers, which was. after all, what the lireman was try-
ing to do.
A general discussion by qualified persons would be ap-
preciated.
L. A. DeBlois,
E. 1. du Tout de Nemours Powder Co.
Wilmington, Del.
v
Sfor,miim©r ana Frntnap Suacftaoini
I have found that a strainer, made as shown in the
illustration saves a lot of trouble by preventing small
sticks and stone- entering the pump and lodging under
the valves.
The strainer is made fast to a brass ring, which will
hold against the end of the pipe and keep the screen from
Jl_
We have had considerable experience on gas explosions,
due to carbon monoxide from soft coal, from natural gas,
etc but are unable to advise you definitely as to the lowest
range or percentage of carbon monoxide and air that would
result in an explosion. While this particular feature is worth
investigation as of scientific interest, yet the percentage of
such air and gas mixtures in a furnace will, of course, vary
widely.
Assuming conditions as described in your letter, we pre-
sume the fire-doors, etc., were so arranged that no air was
permitted to enter above the fire, the supply being from the
blower svstem. Therefore, with the tuyere openings blocked
with clinkers and no air admitted above the fire, carbon
monoxide would be generated faster than it could escape, and
the furnace, and even the chimney (with one boiler chimney),
vould be filled with carbon monoxide, which would rapidly
■De built up to a point where it would be explosive.
It seems if the damper had been open, say 50 per cent.,
when the fireman opened the fire-door the draft would have
quicklv carried away the carbon monoxide and thus averted
the accident. The matter of closing dampers from 75 to 9o
per cent, while the furnace is loaded with coal which is set-
ting free its volatile constituents strikes us as wrong. In
our opinion the damper should have a limit closure when a
boiler is in service.
Removable Stkaixek
being drawn into the pump. A handle, or hail, is conven-
ient to pull the strainer out for cleaning. A tee is used
in the suction pipe instead of an elbow, and the strainer
put in as shown, and a plug is used to close the end of
the tee and to make the appliance easily accessible. The
mesh of the screen should he suitable to the size of the
pump and the kind of service. Brass or copper wire i-
preferable, hut galvanized wire will answer in some cases.
Ithaca. X. V. JOHM P. Koi.u;.
April 20, 1915 PO W E R 555
iiiiiiu iiiiiiiiiiiiiiiiiiii iiiiiiiiiiii i mm i iiiiiiniiiimiiiiiiii iiiiimmiii iiiiimiiiiiiiiiii mi miiimilll iiiiiiiiu i iiiiiiiiiiiiiini mm i in iiiiniuiiiii miiiiiiiiiiiiiiiiin miming
Iirnqpuiiiiriies ©if G©mieirs\Il Iimfteirestl
M
inmiiimiii nun minimum i ■ i ininmiiinii mi i i mmmiinni i minimi imiiimmin iiiiiiiiiiiini iiiiiiu ii mi i i ininmiiiinimi nnniininmnniiiiiil
Side for Connecting Equalizing Switch — On which side of
an electric generator should the equalizing switch be con-
nected "
W. H. M.
An equalizing switch is to be connected on whichever
side of the generator the series field winding is placed.
Vacuum Not Ascertainable from Temperature — Would de-
termination of temperature of the condensate discharged
from a condenser be an accurate method of measuring con-
denser pressure by ascertaining pressures corresponding to
temperatures given in the steam tables?
A. J. F.
The temperature of the condensate would not be a true
indication of the pressure, on account of the presence of air
in the condenser.
Backfiring Trouble — Would placing a wire screen in the
intake pipe of a gasoline engine between the carburetor and
cylinder prevent backfiring?
C. E. S.
A screen would undoubtedly prevent backfiring through
the intake pipe, but would not remove the cause of imper-
fect operation of the engine. The backfiring may be due
to wrong timing of the ignition, improper seating of the
inlet valve, thus allowing the exploding mixture to get by
it into the intake pipe, or a combination of a lean mixture
and too early ignition.
Measure of Ductility — What is the measure of the duc-
tility of a metal?
E. H.
The percentage elongation and the percentage reduction
of area are usually considered together as the measure of the
ductility of a metal. After a bar of the material under ten-
sile stress has passed its elastic limit it begins to be perma-
nently elongated in the direction of the pull. The increase
in length multiplied by 100 and divided by the original length
is the "percentage elongation." When a bar is elongated it
shrinks in cross-section, and just before it breaks it usually
"necks down" at the point of fracture. The original cross-
sectional area minus the area of smallest cross-section after
fracture is called the "reduction area," and this difference
multiplied by 100 and divided by the original area is the
"percentage reduction of area."
Increase of Bolt Tension after Cooling — If a 1%-in. diam-
eter steel bolt is drawn up tight when at the temperature
of 160 deg. P., how much will its tension be increased after
it has cooled to 70 deg. F.?
R. B. N.
If there is no yielding of the head, nut or screw from
compressive stresses, the additional tensile stress in the bolt
due to cooling will be the same as that required for elongat-
ing the bolt as much as it would elongate or contract for the
same change of temperature. The coefficient of lineal ex-
pansion or contraction of steel is 0.0000065 of its length per
degree change of temperature, and therefore the elongation
or contraction per inch of length for a change of 160 — 70 =
90 deg. F. would be
0.0000065 X 90 = 0.0005S5 in.
As for steel, the modulus of elasticity, or load per square inch
of cross-sectional area divided by the extension per inch of
length, is 30,000,000, then for an extension of 0.000585 in. the
stress would be
0.0005S5 X 30,000,000 = 17,550 lb.
per square inch of cross-sectional area, and for 1%-in. bolt,
or a cross-sectional area of
1% X 1% X 0.7854 = 1.767 sq.in.,
the stress would be
17,550 X 1.767 = 31,010.85 lb.
Size of Feed I'ump — What size of single feed pump should
be employed for a boiler which requires 3850 lb. of feed wa.ter
per hour?
W. H. M.
A uniform feed-water supply would be equivalent to
3850 -^8J = 462 gal.
per hour, requiring a pump displacement of
(462 X 231) H- 60 = 1778.7 cu.in. per min.
Bui to meet emergencies the rated capacity should be about
double the delivery required for uniform rate of feeding, i.e.,
neglecting slippage and reduction of piston area due to the
piston rod, the displacement capacity should be about 3558
cu.in. per min. Allowing a maximum speed of 60 strokes per
3558
minute the piston displacement should be , or about 60
60
cu.in. per stroke.
To determine the size of water cylinder, either the area
of the piston or the length of the stroke must be selected.
Neglecting slippage and reduction of the area of piston due
to the piston rod and assuming the diameter of water cyl-
inder as 3V4 in., the area of the piston would be
3'/4 X3!4 X 0.7854 = 8.295S sq.in.
requiring a stroke of
60
7.23 in.
8.295S
and for most practical purposes the commercial size, 5V£x3i4x7
in. (5^-in. diameter of steam cylinder, 3 y* -in. diameter of
water cylinder, 7-in. stroke) would answer.
Pressure Required for Running Noncondensing — If an en-
gine, operated with steam at an initial pressure of 120 lb.
absolute. Vi cutoff and 26 in. vacuum, loses its vacuum, what
initial pressure would be required to operate the engine non-
condensing with the same length of cutoff, the valve setting
and load remaining unchanged?
S. S.
The mean forward pressure per pound of initial is given
approximately by the formula
Pm = (1 +loge R) (f + O— c
in which
Pm = Mean forward pressure per pound of initial (ab-
solute) ;
loge R = Hyperbolic logarithm of the ratio of expansion;
1 + c
R = Ratio of expansion —
f + c
f = Fraction of stroke completed at cutoff;
o = Clearance per cent, of piston displacement.
Assuming 5 per cent, clearance, the ratio of expansion
would be
1 -f c 1 + 0.05
f + c ~~ 0.25 + 0.05
and as the hyperbolic logarithm of o.5 is 1.2528, the mean
forward pressure per pound of initial would be
(1 + 1.252S) (0.25 + 0.05) — 0.05 = 0.6258 lb.
and for 120 lb. initial absolute the mean forward pressure
would be
120 X 0.625S = 75.1 lb.
When running condensing with 26-in. vacuum the back
pressure would be
30 — 26 = 4 in. mercury,
or
4 X 0.491 = 1.964 lb. absolute,
and the m.e.p. of an ideal diagram would be
75.1 — 1.964 = 73.136 lb. m.e.p.
but when running noncondensing the back pressure would be
about 1.5 lb. gage, or about
15 + 1.5 = 16.5 lb. absolute
and to obtain the same m.e.p. (73.136 lb.) for the ideal diagram
the mean forward pressure would need to be
73.136 + 16.5 = 89.636 lb.
If in each instance the actual is the same per cent, of the
ideal diagram, and as the mean forward pressure when cut-
ting off at Vi stroke is 0.6258 lb. per pound initial absolute,
then to realize a mean forward pressure of 89.636 lb. absolute
would require
S9.636 -i- 0.6258 = 143.2 lb. absolute,
or about
143.2 — 15 = 128.2 gage pressure.
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
556
POWE E
Vol. ±1, No. 16
>rtliilbll<
C
oinnilfanuisttiioini
By Alax E. L. Chorltom
One might at first sight say that the combustion engine
most ready to work on different fuels would be of the self-
ignition type, in which the heat of compression is sufficient
to ignite the incoming fuel, and the only change necessary
in going from liquid to solid fuel would be in the fuel-
injection device. In practice, however, owing to the difficulty
with solid-fuel injection, such a type would not prove work-
able, and even when the fuel is first gasified the results do
not justify the complication. The problem of designing an
engine is better met by trying to combine known types for
gas and oil, in which good results are obtained at present
and which in general principles show the same characteristics.
In the normal engines for both gas and oil the chief
difference lies in the degree of compression. Thus, the corn-
type. A change of parts for such an engine does not present
any difficulties. The gas fittings are provided with electric
ignition, which is also suitable when gasoline is used, while
the kerosene and good crude oil would be self-ignited by
the hot bulb. Fig. 1 illustrates the practical application of
these modifications. The results obtained with this engine,
are:
Kerosene . . .
Producer gas
Compression,
Lb. per Sq.In.
Maximum
Pressure,
Lb.
M.E.P.
Lb.
B.t.u. per
B.hp.-hr.
55
90
210
230
58
65
14,500
12,000
This type of engine is suitable only for comparatively low
powers, and the range of fuels does not include any heavier
SECTION A-A
V7?
mot duie
arran6e0 for oil
arranged for gas or gasoline
Fig. 1. Convertible Engine for Small Powers Using Gas and Liquid Fuel
pression of a modern gas engine may vary from 90 lb. when
using coke-oven gas, to 150 lb. for producer gas; while for
the liquid-fuel engine using crude or residual oils the com-
pression pressure may exceed 500 lb., but may be considerably
less if the temperature of ignition is obtained by uncooled
surfaces or auxiliary or pocket firing is used.
As there is no fundamental difference in engines for
gaseous or liquid fuels except in their conventional cycles,
it follows that any schemes of convertibility must provide
means whereby the requisite compressions can be readily
obtained, but as there is a great gap between 500 and 150
lb., the tendency is to combine the lower-compression oil
engine and the higher-compression gas engine and thus deal
than good crude oil. Furthermore, its economy on oil is not
high. It is described here because it contains the basic
principles of a more suitable engine for large powers.
GROUP 2 — This group is represented by the Diesel engine,
with a compression of over 500 lb. when using tar oils
(unless an ignition oil is used). As the maximum compression
for gas normally does not exceed 150 lb., there are mechanical
difficulties in building an engine in which both of these com-
:l \. GAi
Fig. 2. Indicator Diagrams with Oil and with Gas
with a smaller compression-pressure range. The desirable
characteristics of the convertible engine are: Simplicity and
reliability, high economy for each fuel, first cost (little above
that of the standard engine), easy convertibility, and as
nearly as possible the same power developed for each fuel.
Consideration of the subject may be more clearly under-
taken by dividing the types of engines in use into three
groups, with further subdivisions, due to peculiarities of
design: (1) Engines of low compression and low power: (2)
engines of high compression and higher power; (3) engines
of medium compression and higher power.
GROUP 1 — As an example of the first group, take the
ordinary motor-car engine having a compression up to 90 lb.,
and which, with slight modifications, will run on gasoline,
good kerosene with an exhaust-heated carburetor, town gas
and producer gas. It is designed for and works best on
gasoline; fairly well, however, but not so economically, on
town gas: requires very good kerosene and is not efficient
at the low-compression with producer gas.
To extend the range to use a poorer grade of kerosene
or a good grade of crude oil, means must be provided whereby
more heat is available for the ignition. This can be con-
veniently done by the addition of an unjacketed portion to
the cylinder head; then the engine becomes of the hot-bulb
Fig. 3.
Convertible Engine with Exhaust Valve
Attached but without Head
pressions can be obtaineJ with reasonable modification.
Furthermore, the Diesel has an expensive high-pressure com-
pressor which is unnecessary for the ordinary type of gas
engine. Apart from mechanical difficulties, we may compare
the commercial possibilities of this type, the oil and gas
sides being
as follows for engines
of the
same cylinder
dimensions:
Abnormal
Maximum
Compression, Pressure,
Lb. per Sq.In. Lb.
M.E.P
Lb.
Approx. B.t.u.
per B.hp.-hr.
Oil engine . .
Gas engine.
500 Over 1000
150 600
100-110
SO
sooo
These figures show how incompatible the two designs
are, for they illustrate that the Diesel structure must be
built twice as strong for the very high maximum possible
pressure, owing to the fuel valve sticking, etc. The higher
April 20, 1915
POWB R
557
mean effective pressure used is some compensation for thin
extra cost and weight. The mean cylinder pressures reveal
a still further disadvantage when the gas conversion is con-
sidered; for besides this high first cost, there is a reduced
power, owing to working at a lower mean effective pressure —
80 as against 100-110 lb. A convertible engine on theae
lines does not seem a commercial possibility.
Same Engine as in Fig. 3 Arranged for Oil
and fob Gas
GROUP 3 — The range of the compression of these engine3
lies between that of Groups 1 and 2, and usually is from
150 to 300 lb. A compression of 150 lb. is suitable for most
forms of producer gas, but because of preignition it is not
usually exceeded. On the other hand, it is necessary for all
compressions below self-ignition pressure to employ some
auxiliary means to obtain the necessary temperature for the
proper combustion of the residue oil. Normally, the additional
heat is obtained by an unjacketed surface or ignition bulb
at the cylinder end.
The various devices concerning temperatures, compression
and convertibility of this group may be considered by sub-
dividing it under the following heads:
a. Engines working with a compression not exceeding 150
lb. both for oil and gas, and which may employ pocket-firing
with or without air injection for one and electrical ignition
for the other, or some combination, the smaller compression
not involving material mechanical changes of the parts.
b. Engines working with a higher compression for oil
than gas, involving some modification of the combustion
chamber by substitution of a part for oil as against a part
for gas; otherwise maintaining the simplicity of both types.
c. Engines obtaining the necessary change from gas to oil
by temperature control of the air charge, together with
alteration of the valve settings.
d. Engines employing the super-compression of Dr. Dugald
Clerk, to control effectively the compression required for
either fuel. (Pinal ignition temperature by other means.)
Under subdivision a there are a large number of engines
used only for oil, but which might, without much alteration,
become effective in the use of gas, although the whole
combination is not as efficient as the highest individual
member.
In considering division 1>, a useful comparison of its
possibilities is given in tabular form, for engines of the
same cylinder dimensions:
It will be seen from this that the outputs and general
figures relative to the engine bear a great similarity. More-
over, the diagrams of Fig. 2, taken when running on oil and
on gas, are similar. Therefore, the possibilities of this type
of convertible engine appear great, and an engine which has
been made in considerable numbers to fulfill these conditions
is shown in Figs. 3 and 4. (Built by Messrs. Ruston, Proctor
& Co., Ltd.) These views show clearly that in both casesr
the engine presents the ordinary features of the four-stroke-
cycle type, and the only change involved in converting from
oil to gas lies around the combustion bulb of the oil engine,
and in the change from an oil-type to a gas-type piston.
The arrangements in division c may be justified for
mechanical and constructional convenience, but they can
hardly be defended on the score of efficiency. In one method
the jacket of the cylinder cover is formed to withstand a
pressure, and is worked in the manner of a boiler. The
increased heat is impressed in the charge of air during the
compression stroke to raise the temperature sufficiently for
ignition. This arrangement thus replaces the hot-bulb or
unjacketed end of the cylinder. It has some advantages, in
that it is perhaps more controllable and the steam generated
may be used for some useful purpose, perhaps in conjunction
with an exhaust-heated boiler for an auxiliary steam cylinder
on the main engine. The water injection of some hot-bulb
engines is also done away with. This type of engine is
unusual in practice.
When in use as a gas engine, such a convertible machine
would have to dispense with the pressure-jacket temperature
when using the lower compression and temperature needed
for such an engine. Actual heating of the inlet air may be
a practical convenience for dealing with a particularly re-
fractory oil not amenable to the available compression of the
engine. The valve setting may be modified to give suitable
compressions for oil and gas; this can be worked in conjunc-
Abnormal
Maximum
Compression,
Pressure,
M.E.P.
B.t.u. per
Lb. per Sq.In
Lb.
Lb.
B.hp.-hr.
.... 250-280
fiOO
600
80
80
Gas engine.. . .
150
N.Miii
Section through Clerk Super-Compression
Engine
tion with the temperature arrangement just described. The
gas engine, however, suffers in loss of output.
The Clerk super-compression engine (Fig. 5) is a
much more suitable and promising type for dealing with
the variable compression problem of the convertible engine.
In this, an extra charge of air or inert gas is added to the
working mixture at the end of the suction stroke, by which
means much lower maximum flame temperatures are obtained
and a higher mean cylinder pressure is rendered possible.
As a convertible engine, it is particularly suitable, for by
varying this amount of added air the compression can be
adjusted between wide limits, the final temperature being
controlled by any of the previously indicated means. For
instance, with a compression of 300 lb. maximum, the full
displacement of the air pump may be used; for the lower
compression of the gas engine one can, by any suitable
valvular means such as an ordinary bypass, reduce the amount
of discharge as required.
CONCLUSION — The conclusions of the author are that, for
powers up to say 1000 b.hp., a type such as the Ruston is
the most suitable as a convertible engine, while for still
larger powers, when tandem engines and size and weight
of removable parts become a problem, the Clerk super-com-
pression type offers very interesting and hopeful possibilities
in this field.
558
P 0 V B I!
Vol. -41, No. 16
Tr©unlbl(
jmco^ninifteredl wMIh
CarBomi
Bir^m*
>Ih(
By E. II. Maetindale
SYNOPSIS — The paper is divided into five sec-
tions, based on the location of the cause of the
trouble: (1) field, (2) armature, (S) commuta-
tor, including brush rigging, (Jf) external electri-
cal, and (5) external mechanical.
The characteristics of carbon brushes which commonly af-
fect the operation are resistance, hardness, abrasiveness, co-
efficient of friction, contact voltage drop and heat conduc-
tivity. None of these terms needs explanation, but the writer
wishes to emphasize the importance of not confusing hard-
ness with abrasiveness. By abrasiveness is meant the scour-
ing or cutting action of the brush. Relative hardness may
be judged by cutting the brush with a pocket knife or by
marking with it on paper, or if more accuracy is desired, a
set of pencils from 2B to 8H will be an aid, as a pencil softer
than the brush will mark it and one harder will scratch it.
The hardest brush with which the writer is familiar has no
abrasive action, while one of the softest has a decidedly
abrasive action.
FIELD TROUBLES
As the field coils are connected in series or series parallel,
a partial short-circuit may occur in one coil without ma-
terially affecting the heating of the coil. This is usually at-
tended with severe sparking at one or two studs, although in
a wave-wound machine the commutation may be little af-
fected. This trouble can best be located by noting the voltage
drop across each coil with a constant current through the
coils. Similar trouble may be caused by an error in rewinding
a field coil. On some machines the shunt fields are con-
nected with two or three fields in series and two or mere of
these groups in parallel. A partial short-circuit in one coil
will then affect the entire group, electrically unbalance the
machine, and cause heavy short-circuit currents.
In a cumulative compound machine one series field may be
reversed accidentally and, as the load increases, sparking will
occur usually at two adjacent studs; or the entire series
field by mistake may be connected to oppose the shunt field,
which will result in blackening of the commutator, with
severe sparking at heavy loads. The best way to detect this
is to excite separately the shunt and the series fields, being
sure that the current flows in the same direction as when the
machine is in operation. The polarity of each pole should be
tested with a compass and should reverse as the compass is
passed from one pole to the next. Furthermore, the polarity
of each should be the sanW when either field is excited. In a
generator the voltage will decrease and in a motor the speed
will increase as the load increases.
Unequal air gaps are responsible for much commutation
trouble. If one pole face is nearer the armature the flux
across the gap is greater and a higher voltage will be de-
veloped in the coils under that pole. This may result in heavy
short-circuit currents between the studs adjacent to that
pole and other studs of the same polarity.
ARMATURE
An open circuit in an armature coil causes the most vicious
form of sparking, accompanied by pitting of the mica be-
tween the commutator bars connected to this coil and the ad-
jacent ones. The usual method is to connect an incandescent
lamp in a testing circuit, and with two pointed terminals make
a bar to bar test on the commutator; the open circuit is shown
when the lamp does not light. Similar sparking in a lesser
degree may be caused by a high-resistance connection be-
tween the end of a coil and the commutator riser. This can
be detected by passing a current through the armature and
noting the voltage drop between adjacent bars, as the voltage
will be higher than normal when the poor connection is in
the circuit measured. This method may also be used to detect
an open circuit, but a voltmeter reading as high as the volt-
age impressed on the armature must be used.
A short-circuit between two sections of a coil, two coils in
the same slot, the end connections of two coils, or between the
commutator bars, will be evidenced by excessive heating of
the coils affected, and unless repaired will sooner or later re-
sult in a burned-out coil. The same method may be used
as in the preceding case, and the voltage between adjacent
bars when the coil is in the circuit will be below normal.
The demagnetizing and cross-magnetizing actions of an
armature have serious effects on the commutation of many
machines. To get good commutation in a non-interpole ma-
chine, the brushes usually must be set ahead of the mechan-
ical neutral on a generator and back of the mechanical neutral
on a motor.
If the brushes are shifted far to obtain good commutation,
and if the magnetization of the polepieces is not well above
the knee of the saturation curve, the demagnetizing effect of
the armature may seriously reduce the voltage of a gen-
erator or increase the speed of a motor. On the other hand,
the cross-magnetizing effect may be sufficient, if the brushes
are not shifted to the electrical neutral, to place the coils
undergoing commutation in a heavy field, with resultant
heavy short-circuit currents, severe sparking at the brushes
and all the attendant evils. The remedy is to widen the
neutral field by filing away the edges of the polepieces.
COMMUTATOR
Commutator-brush troubles are numerous, and often diffi-
cult to identify. One of the most troublesome problems with
non-interpole generators or motors which do not operate at
Unequal Spacing Due to Brush-Holders Being
Rotated Too Far
constant load is the difficulty of finding a point at which the
brushes will operate at all loads without injurious sparking.
This is due to the cross-magnetizing action described.
Spring tension, or the pressure with which the brushes
bear on the commutator, seldom receives proper attention.
The most economical pressure is the lowest consistent with
a low contact loss, a clean commutator and freedom from
sparking, glowing or pitting of the brushes. It is seldom
advisable to use a pressure less than 1% lb- Per sq.in. of
cross-section. The writer recommends on stationary ma-
chines a pressure of from 2 to 4 lb., depending on local con-
ditions and the grade of brush; and from 4 to S for crane
motors, haulage motors, railway motors and similar machines.
Brush spacing is important, but is usually neglected. In
the sketch the studs are equally spaced and the dotted lines
show the correct brush position, but owing to the brush
holders on arm A being rotated too far in one direction and
on arm C too far in the opposite direction, the voltage gen-
erated in section ABC is different from that in AFE or CDE,
and this will result in short-circuit currents between A. B
and C, high enough to neutralize the unequal voltage.
The magnitude of this short-circuit current may be illus-
trated by a test conducted a few years ago by the writer
on a 400-amp., 250-volt, six-pole shunt generator. On one
positive stud the brush holders were rotated to place the
brush % in. ahead of the collect position; the other positive
studs were left unchanged. With the brushes incorrectly
April 20, 1915
P 0 W E E
55!)
spaced but operating at the best point, the short-circuit cur-
rent was not excessive. When the brushes were shifted two
bars away from the neutral and with no external load on
the machine the short-circuit current rose to 800 amp., or
twice the normal full-load current. As the voltage back of
this current was low the actual power loss was small, but the
heating of the windings ami the effect on the commutator and
brushes were serious. This is an extreme case, but a smaller
difference in spacing may often be serious.
From the time a commutator bar touches one edge of a
brush until it leaves the opposite edge, the current in the
coil undergoing commutation should fall from full load to
zero, and rise in the opposite direction to full load. If the
current in the coil is more or less than that value, the final
adjustment comes as a sudden rush of current as the bar
leaves the brush. In many machines the time of commuta-
tion is less than 0.001 sec. The blushes should therefore be
shifted to a point where the coils undergoing commutation
are in a field strong enough to make this change. If the
brushes are too thin, sufficient time is not allowed for commu-
tation, and if too thick, the coil may over-commutate.
If there is not sufficient clearance between a brush and its
holder or if foreign matter becomes lodged in the holder, the
brush will not move freely and may make poor contact, re-
sulting in blackening of the commutator, sparking, heating
and other evils.
On the other hand, if there is too much clearance and the
brushes are not equipped with shunts, the current may pass
from the brush to the brush holder through a small arc and
cause undue wear of the holders. On machines which have
been in service a long time trouble frequently arises from
worn holders. This is particularly true if the machine runs
in both directions, as the brush face changes when the ma-
chine is reversed and thereby reduces the time of commu-
tation and increases the current density in the brush faces.
Brushes in worn holders are also more inclined to chatter
and chip.
Brushes are sometimes ordered longer than standard with
a view to securing a long life, but the spring usually trie, 3
a side push and causes trouble, which shortens the life i f
the blushes and perhaps damages the commutator.
Noise of carbon brushes is due to a mechanical vibration
called chattering. If due to the friction of the brush on the
commutator, the noise may have various pitches. The remedy
is a change in spring tension, angle of operation or grade of
brush, although relief may be obtained by lubrication of the
commutator at intervals. If the noise results from high mica
or wide slots in a slotted commutator, the pitch of the sound
will correspond to the number of bars passing under tne
brush in a second. If the noise is caused by slots, it may
be necessary to change the spring tension, the angle of oper-
ation, or grade of brush, as lubrication is not advisable on a
slotted commutator.
Pitting or honeycombing of the brush faces is nearly al-
ways caused by short-circuit currents or a very low brush
pressure, but occasionally it is due to insufficient current car-
rying capacity of the brushes. Many cases of pitting may be
corrected by reducing the thickness of the brushes, but it is
better to look for some other cause first, as already de-
scribed.
A loose commutator bar may be flush with other liars when
the machine is stationary, but may be thrown out slightly
when running, owing to centrifugal force. This will lift the
brush and will burn one or more bars just ahead of the high
bar, depending on the number which the brush spans, and
further, will burn some of the bars back of the high bar,
depending largely on the speed of the machine and the
brush pressure. Its presence can often be detected by the
knocking sound of the bar hitting a brush once every revolu-
tion.
In repairing commutators and sometimes in manufactur-
ing them, commutator bars of different hardness are used,
and one bar may wear faster than another, causing a flat spot
or a high bar.
Blackening of a commutator may be caused by sparking,
the use of too much lubricant, or by the character of the
brush. Blackening will sometimes occur on every alternate
bar or every third bar, corresponding to the number of coils
per slot, and may often be shifted to another group of bars
by shifting the location of the brushes. This seems to be
due to a magnetic kick in the coil undergoing commutation
wh.n the armature tooth next to the coil suddenly leaves
the field. The remedy is to have the neutral field wide enough
to permit the tooth to leave the strong field before the commu-
tator bar comes under the brush.
The best practice in commutator slotting consists in under-
cutting the mica about 8/« in. below the surface of the com-
mutator. It is important that great care be exercised to see
that all the slots are free from strips or particles of mica
flush with the commutator. It is not advisable to use lubri-
cant or artificially lubricated brushes on a slotted commutator,
as the lubricant may get into the slots, collect dirt and cause
short-circuits between bars. On slow-speed machines, where
the peripheral speed is not sufficient to throw out particles of
dirt, the commutator slots should be blown out or scraped
out at regular intervals. On a slotted commutator a brush
with no abrasive action may lie used and will result in long
life of the commutator and brushes. A non-abrasive brush
or a self-lubricating brush does not necessarily mean a soft
brush.
Heating of the commutator on a machine may be caused by
any form of sparking, short-circuit currents, friction of
brushes, high brush pressure, too low brush pressure caus-
ing high contact loss, dirty commutator, overloads, too small
commutator, resistance of windings, loose connections, eddy
currents and hysteresis. As the ultimate capacity of a ma-
chine depends on the allowable temperature rise, it is im-
portant to prevent heating wherever possible.
OUTSIDE ELECTRICAL CAUSES
Outside electrical causes of commutation trouble may be
briefly stated as overloads, line surges, and cross currents be-
tween two or more machines running in parallel. Where the
angular speed of a reciprocating engine varies greatly, surges
may occur, caused by a slight reduction in speed of motors on
the circuit when the voltage is low and a consequent rush
of current when the voltage leaches its maximum. It may be
impossible to locate surges or cross-currents without the
use of an oscillograph.
OUTSIDE MECHANICAL CAUSES
If an armature is mechanically unbalanced severe vibra-
tion may occur, especially if it is run at high speed. This
may produce flat spots, unbalanced electrical conditions,
loosening of commutator bars and other serious troubles.
If the machine is on unstable foundations similar troubles
may be experienced, owing to vibration of the entire machine.
In this class may be placed crane motors and similar ma-
chines which, however, are usually designed with this factor
in view. Poor belt lacing or uneven gears may produce vibra-
tion or strain, with the same results.
The third part of '.he Institute of Metals' "Contributions
to the History of Corrosion" has been issued. It consists of
a contribution by Arnold Philip, Admiralty chemist, attacking
the conclusions of G. D. Bengough and R. M. Jones, and a
supplement containing their reply. An abstract of the first
two parts appeared in "Power," Dec. 2, 1913, page 7S1.
We do not reproduce the third part at length, as it seems
largely to reinforce Bengough and Jones' original work and
conclusions, namely, that entrained pieces of coke are not
grave causes of condenser-tube corrosion. Some of their
minor points concerning the technique of their experiments
may, however, be of interest.
The point is made that the method of determining loss of
weight is of little use in investigating corrosion. Of all fail-
ures, 90 per cent, "are caused by local dezineification, and
when once this has been started loss-of-weight methods are
useless. The action was quite local and irregular, and the
white zinc salt was strongly adherent and usually could not
be removed without injury to the underlying oxide layer."
The authors conclude that, consequently, a means of de-
tecting dezineification is the only rational way of detecting
the progress of corrosion. Here they leave us at sea. The
only method available giving actual measurement seems to be
microscopic investigation, especially of sections cut at right
angles to the supposed dezincified spot. This involves de-
struction of the specimen. The next best is a hardness test
by rubbing with a blunt steel needle, the dezincified area be-
ing softer than the unchanged brass. In fresh specimens the
eye with proper training can detect the dezincified spots, even
in the early stages; in old specimens the copper oxidizes, and
this copper cannot be told from the ordinary oxide layer.
Another point made is that when various plates of metal
are being tested for resistance to corrosion it is not fair to
take pieces of tube and flatten them, or clean them, or anneal,
or in any other way alter the normal skin of the metal. After
attention has been called to this it seems self-evident, yet we
have known cases where it has not been observed.
Another point spoken of is that sea water to which suffi-
cient sodium carbonate has been added to make it alkaline
in reaction instead of neutral, r.£ is normal sea water, is
much more active in producing dezineification than the nor-
mal sea water. Here is a practical point in condenser prac-
tice.
-,bO
pow e n
Vol. 41, No. 16
S£„ IL©^
.©Easusffiffies's
as
The Engineers' Incitation Club, representing consumers
of electricity in St. Louis, has filed a petition with the public-
service commission of Missouri, protesting against the al-
leged discriminatory rates charged by the Union Electric
Light & Power Co., of that city. The present maximum rate
to small consumers is 10c. per kw.-hr., whereas it is charged
that certain large consumers pay less than lc. per kw.-hr.
The petitioners would have the rate fixed at a maximum of
5c. per kw.-hr. for the first 120 hr. of installed capacity
used per month, with all in excess thereof at 2%c. per kw.-hr.
It appears that the Union Electric Light & Power Co.
procures a large portion of its supply from the Keokuk hydro-
electric development. This power is generated by the Mis-
sissippi River Power Co., but instead of purchasing direct
from this company the defendant buys through intermediary
companies known as the Mississippi River Power Distributing
Co. and the Electric Co. of Missouri. It is alleged that these
corporations are under common control and through collusive
agreements are defeating the purpose of Congress in making
the water-power grant, and instead of the public being the
beneficiaries of low rates, a few promoters and stockholders
in the companies mentioned are reaping the benefit.
EHQIHEEIRIIHG AFFAHIRS
American Association of Refrigeration Meeting; — The fifth
annual meeting of the American Association of Refrigeration
■will be held at the Hotel Astor, New York City. May 11 and
12. There will be important reports from officers and stand-
ing committees and commissions of the association, including
a detailed financial statement of the Third International Con-
gress of Refrigeration.
The Ohio Society of Mechanical. Electrical and Steam En-
gineers will hold its next meeting June 17 and IS, at Toledo.
Plans are being made for an outing, together with the regular
reading and discussion of papers. Among papers to be given
are: "Firebricks for Boiler Settings," by W. G. Heisel; "Some
Features of the Cleveland Municipal Lighting Station," by
F. W. Ballard; "Low-Pressure Turbines," by a representative
of the General Electric Co., and "Attainment and Mainte-
nance of Boiler-Room Efficiency," by a representative of the
Harrison Safety Boiler Works.
The American Boiler Manufacturers' Association and the
National Tubular Boiler Association at a joint meeting held
in Pittsburgh on Mar. 29 unanimously approved the Code of
Boiler Specifications prepared by the committee appointed
for that purpose by the American Society of Mechanical En-
gineers, and steps were taken toward securing its adoption
by the various states. Several of the members and the rep-
resentative of a prominent boiler-insurance company declared
that they should adopt it as their standard, whether com-
pelled to by legislation or not.
The National Gas Engine Association is to hold its annual
meeting on June 23 and 24 at the La Salle Hotel, Chicago.
Reports will be presented by the Standardization. Insurance,
Cost Accounting, Legislative and Publicity committees. The
following papers are scheduled: "The Data Work." by Prof.
P S. Rose; "Educating the Buyer to Tour Type of Engine,"
by H. G. Diefendorf; "Possibilities of the Farm Lighting
Plant," by C H. Roth; "What of the Kerosene Engine?" by
C. E. Bement; and papers by unannounced speakers on "The
Future Work of the Association," "How Dealers May Be
Induced to Buy for Cash" and "The Magneto of the Future."
An accessory exhibition will be arranged, space in which can
be secured by addressing the secretary, H. R. Brate, Lake-
mont, X. Y.
COAL GAS RESIDUALS. Bv Frederick H. Wagner. Pub-
lished by the McGraw-Hill Book Co.. 239 West 39th St..
New York, 1915. Cloth; 179 pages; 6x9 in. Price, $2.
Convinced that, even under normal conditions, the recovery
of coal-gas residuals is an important means of conserving
our natural resources, Mr. Wagner has described German
theory and practice in recovering coal gas byproducts and
has given estimates of initial and operating costs and of the
possible income from the production of tar. naphthalene, cyan-
ogen, ammonia and benzol. Coke is not considered, but is to
be treated in a separate volume. Most of the methods out-
lined were devised by the German chemist Feld, and relate to
installations in Germany. Unfortunately, no photographs are
given, but the book is illustrated by drawings of the different
apparatus required.
PRACTICAL IRRIGATION AND PUMPING. By Burton P.
Fleming. John Wiley & Sons, Inc., New York. Cloth;
226 pages, 5%x8*4 in.; 27 illustrations; tables. Price, $2.
HEATING AND VENTILATING BUILDINGS. By R. C. Car-
penter. John Wiley & Sons, Inc., New York. Cloth;
sixth edition; 598 pages, 6x9^4 in.; 290 illustrations; ta-
bles. Price, $2.
HEAT ENGINEERING. By Arthur M. Greene, Jr. McGraw-
Hill Book Co.. Inc., New York. Cloth; 462 pages, 6x9%
in.; 19S illustrations. Price, $4.
CENTRIFUGAL PUMPS. By R. L. Daugherty. McGraw-Hill
Book Co., Inc.. New York. Cloth; 192 pages; 6x9% in.;
Ill illustrations; tables. Price, $2.
VOCATIONAL MATHEMATICS. By William H. Dooley. D.
C. Heath & Co., New York. Cloth; 341 pages; 5x7'2 in.;
illustrated: tables. Price, $1.
McNab & Harlin Mfg. Co., 55 John St., New York. Bul-
letin. Brass fittings. Illustrated, 5x7 in.
Trill Indicator Co., Corry, Penn. Booklet. Outside spring
engine indicator. Illustrated, 16 pp., 6x9 in.
The Scranton Pump Co., Scranton, Penn. Bulletin No. 101.
Duplex piston pumps. Illustrated, 16 pp., 6x9 in.
Armstrong Cork Co., Pittsburgh, Penn. Folder. Nonpareil
high-pressure covering for boilers, etc. Illustrated.
"Gripwell" Pulley Covering Co., Candler Building. New
York. Folder. Gripwell pulley covering. Illustrated.
The Lagonda Mfg. Co., Springfield. Ohio. Catalog W-l.
Lagonda locomotive arch tube cleaners. Illustrated, 12 pp.,
6x9 in.
York Mfg. Co.. York, Penn. Booklet. Ice-making and re-
frigerating machinery, ammonia fittings and supplies. Illu-
trated. 20 pp.. 6x9 in.
Automatic Steam Trap & Specialty Co., Detroit, Mich. Cat-
alog No. S. Barton expansion automatic steam trap. Illus-
trated, 16 pp., 3%x6 in.
Hercules Float Works, 200-10 Franklin St.. Springfield,
Mass. Catalog. Seamless copper floats and air chambers. Il-
lustrated, 8 pp., 4xS% in.
Harbison-Walker Refractories Co., Pittsburgh, Penn. Cat-
alog. Silica, magnesia, chrome and fire clav brick, etc. Il-
lustrated, 160 pp., 4x6% in.
Yarnall-Waring Co., Chestnut Hill, Philadelphia, Penn.
Bulletin R. A. Richards unloaders for air compressors. Il-
lustrated, s pp., 6x9 in.
Chicago Pneumatic Tool Co.. Fisher Building, Chicago, 111.
Bulletin No. 34-M. Class O steam and power driven com-
pressors. Illustrated, 36 pp., 6x9 in.
BUSHMESS ITEMS
Swift & Co.. Chicago, 111., have recently placed an order
with the Builders' Iron Foundry, Providence, R. I., for an
extra heavy 4-in. Venturi meter tube with type M register-
indicator-recorder for use on their boiler feed service.
The Ingersoll-Rand Co., 11 Broadway, New York, has just
issued Form 3015, "Portable Air Compressors," which is a
32-page illustrated treatise on the subject of portable air-
compressing outfits. Copies are mailed free on request.
The American District Steam Co., of North Tonawanda. N. Y.,
has opened offices at Suite 610, West Street Building, 140
Cedar St., N. Y. This office will be in charge of G. C. St.
John, formerly president of the New York Steam Company.
The Elliott Co.. 690S Susquehanna St.. Pittsburgh, Penn.,
has published two new leaflets of interest to power-plant
men, one on twin oil strainers, type "U," and the other (Bul-
letin J) on pump governors. Copies will be sent on appli-
cation to the company.
J. G. De Remer, member of the American Society of
Mechanical Engineers, American Institute of Electrical Engi-
neers, and formerly chief mechanical and electrical engineer
of the United Light & Power Co., San Francisco, has been
made manager of the general engineering department of the
American District Steam Co., of North Tonawanda, N. Y.
The Canadian Fairbanks-Morse Co., Ltd., has been ap-
pointed selling agent in Canada for Penflex metal hose, man-
ufactured by the Pennsylvania Flexible Metallic Tubing Co..
Broad and Arch St.. Philadelphia. The Canadian Fairbanks-
Morse Co. lias branches in l-i of the largest cities of Canada.
and will carry a complete stock of Penflex in different sizes
and styles at its different warehouses, so that Canadian con-
sumers will have the same service as purchasers on this
side of the boundary.
POWER
Vol. II
\K\V FORK, APRIL 37, L915
No. 1?
SUNDAY SUPPLEMENTS often attract
our attention
By printing, with scareheads two inches
in height,
An extended account of some splendid invention
Whose wonderful value has just come to light.
We are calmly assured that, for turning out
power,
This latest contraption will soon be supreme,
But its memory lives for a day or an hour,
And still we rely on the pressure of steam.
Just as likely as not, it's a new style of turbine,
Designed to be run by the ambient air,
And adapted for service in regions suburban,
In cities, in deserts, and most anywhere;
Or if not, it's a waterwheel, complex and weighty,
Intended to turn in the rush of a stream,
With a total efficiency tar above eighty —
Yet still we depend on the power of steam.
Now and then it's a form of perpetual motion,
Producing its energy quite without cost,
Or perhaps it's a wave motor set in the ocean
To harness the forces that long have been lost.
And our minds are amazed at the marvels of
science
Displayed in each clever, ingenious scheme,
But we pass them all by, and we pin our reliance
On motors deriving their power from steam.
We are told that the gas engine sooner or later
Will drive out the type that we credit to Watt,
But as gas-fuel prices grow steadily greater,
Deep down in our hearts we are sure it will
not.
So we dig out our books, as befits modern
toilers,
And leave the romancer to fancy and
dream,
While we add to our knowledge of
engines and boilers,
Convinced that there's
always a future for
steam.
562
P 0 W E R
Vol. 11, No. 17
jm&ainK
nimeinie
ter9 Imi<
By Thomas Wilson
SYNOPSIS — .1 1,.00-kv.a., two-unit plant generat-
ing current for light and power and the pumping
of city water. Furl costs less than y±c. per hw.-
hr. The operating cost is 0457c, and including
overhead, the total cost is 0.96c. per hw.-hr.
In the past few years the Diesel engine has made rapid
progress, and it is now generally conceded that there are
certain fields in which it excels. Where oil can be bought
at a reasonable figure, these engines, as now made, show
which is operated by the Citizens Heat, Light & Power
Co., contains two 200-kv.a. units, furnishing commercial
and street lighting for "Winchester and four adjacent
towns. Power service is supplied over the same circuits,
and at the station, current for pumping water to the
home town and to run the air compressors serving the
prime movers. Three-phase current is generated at 2300
volts. During the day one unit will carry the load, which
runs up to 160 kw. At the peak, which lasts from 5 to
10 p.m., the load is practically double, and in the morn-
ing hours it is comparatively light. It is thus evident
Fig. 1. Diesel-Engine Fnits
remarkable results. The initial expense is high, but this
is offset by an operating cost so low that the total per
unit of output will fall below thai of the average steam
plant. There are no stand-by losses, and with proper care,
maintenance is no higher than with steam. The engine
may be brought into service on short notice, and the labor
required to operate is less than would maintain a steam
plant of equal capacity. In plants under 10(10 hp., such
as would be employed in small factories or for the lighting
of small towns, the Diesel engine is at its best.
An interesting example of a small central station tend-
ing to prove the above assertions may be found in Win-
chester, Inch, which has a population of 5100. The plant.
that one machine must be operated continuously and the
other for live hours, the two running in parallel. During
the latter period there is no reserve unit. Both machines
must operate every day, and for the past two years
and three months, during which they have been m
service, this schedule has been maintained without a shut-
down.
The engines are of the three-cylinder vertical type,
16x24 in., with a speed of 165 r.p.m. They are rated at
225 hp. and are connected directly to 200-kv.a., three-
phase, 60-cycle generators, which, at SO per cent, power
factor, will deliver 160 kw. As shown in Fig. 1, the
exciters are belted to the shaft. The latter machines are
April
1 9 1 5
POWER
563
rated at 11 kw. and are driven al a speed of 600 r.p.m.
The two units arc exad duplicates.
Air for fuel injection and starting is supplied by two
three-stage, motor-driven air compressors and is stored
at a pressure of 60 atmospheres, in in steel bottles. This
is equivalent to 882 lb. per sq.in., and on heavy loads the
pressure is run up to 955 Lb. When only one engine is
running, the smaller compressor, which has cylinders 8, 5
and 2% l'\ <s in., is operated. This machine is belt-driven
by a 25-hp. induction motor. The other compressor,
which has cylinders 10, 6*4 and 3 by 12 in., is large
enough to serve the two engines, and is operated during
the peak load. It is belt-driven by a 50-hp, induction
motor.
Jackel water is drawn directly from the mains and is
returned to the reservoir, located near the plant. As a
large quantity is used for this purpose, the -: '•• '■""-
perature is small, so thai no lime -is deposited in the
jackets.
Fuel is stored in an underground oil house located be-
tween the plant anil the railway. It has two 8000-gal.
tanks, which are filled by gravity from railway tank cars.
An interesting method was used when installing these
tanks. Everything, including the foundation, was made
ready for their support. The pit was then tilled with
water and the tanks rolled into Jhe opening. As the water
was pumped out, they gradually settled and were guided
into place with little difficulty.
From the underground storage two elevator tanks in
the engine room are filled with oil by a motor-driven
pump, or by a band pump which has been provided to
guard against emergencies. From this elevated location
on the engine-room wall, the oil flows by gravity through
a strainer to the fuel pumps, which force it up to the
Fig. 2. Motor-Driven, Three-Stage Compkessor
fuel valves. A meter attached to each engine measures
the quantity of oil in gallons, and a gage shows the pres-
sure in the air line.
The plan! is equipped with an uptodate switchboard
consisting of nine gray-slate panels, carrying horizontal
edgewise ammeters and voltmeters, polyphase integrating
wattmeters, induction watt-hour meters on the different
circuits, a synchronizing indicator, a power-factor indi-
cator and a Tirrill voltage regulator. The switches and
copperwork are standard throughout.
Water for the City of Winchester is obtained from a
reservoir on the premises, which is supplied from seven
8-in. wells 190 ft. deep. A pressure of 45 lb. is main-
tained on the system, and in case of fire it may be run
np to 95 lb. To supply this water, three triplex
power pumps are installed in the station. Two of these
have a capacity of 250,000 gal. each per •.' 1 hr. One is
driven by a synchronous motor which has double the
capacity needed and is over-excited to raise the power
factor on the electrical system. The other is driven by a
40-hp., 8xl2-in., three-cylinder gas engine. A large fire
pump of the same general design, driven by an induction
motor, is also installed. Its capacity is 150,000 gal. per
'.J t hr. Ordinarily, one of the smaller units will supply
the demand for water. In ease of lire the second small
unit, or tin' lire pump, which is large enough to supply
all requirements may be started. Natural gas from a
Fig. 3. Switchboard
commercial pipe line is used in the gas engine. An addi-
tional source of power is thus afforded that will tend to
prevent a shutdown should anything happen to the elec-
trical plant.
Cost of the Equipment
Table 1 gives the cost of the generating equipment as
entered on the company's books. The engines, air com-
pressors and everything required for their operation cost
$29,000; the generating equipment. $5000; foundations
TABLE 1. COST OF GENERATING EQUIPMENT
Engines and air compressors $29,000
Generators 5.000
Foundations and installation 2,
Switchboard B.OOO
Building and oil tanks 10,000
Total $52,000
Rated engine horsepower 450
Generating capacity, see. p.f., kw 320
Cost per horsepower , fit 5.55
Cost per kilowatt $162.50
TABLE 2. OIL USED AND COST PER UNIT
Fuel Cost
i >il per per
100 Kw.- Cost of Kw.-Hr.
Months Kw.-Hr. Gal. Oil Hr., Gal. Oil at 3c. Cents
November, 1014.. HIT. 270 8,280 7.7 $24S.40 0,2316
December, 1914.. 119,560 9,250 7.7 277.50 0.2321
January, 1915 94,010 S.930 9.5 267.90 0.2849
Totals 320,840 26,460 S.2 $793.80 0.2474
and installation. $2000; making a total of $36,000. Per
kilowatt of generating capacity, this reduces to $112.50.
Adding to the above total the cost of the switchboard, the
building and the oil-storage tanks, gives a total of $52,000,
or $162.50 per kilowatt of generating capacity. Com-
pared to the cost of a steam plant per unit of generating
capacity, this is high. Interest and depreciation on thi<
figure naturally handicap the plant, but are more than
offset by the low operating cost.
Data taken from the log book for the three months
previous to the writer's visit show that the load averaged
over 100,000 kw.-hr. per month. The quantity of oil used
averaged 8.2 gal. per 100 kw.-hr., which is a trifle under
564
POWER
Vol. 41, No. 17
0.6 Hi. per kw.-hr. The fuel oil used ranges in density from do with the maintenance item. Lubricating oil. waste and
32 to 34 deg. Baume and its cost delivered in tank-car supplies averaged $20 per month. The sum of the va-
lots was 3c. per gal. Dividing the total cost of the oil by rious operating items is only 0.457c. per kw.-hr., and when
the total output in kilowatt-hours, the average fuel cost an overhead of 12% per cent, is added, the total is below
for the three months was 0.2474c. per kw.-hr. This is lc. per kw.-hr. delivered to the switchboard. This show-
ing is exceptional for a small plant, and if the load should
increase up to the rapacity of the generating units, the
overhead cosi per unit will be reduced, which in turn
will lower the total operating cost appreciably.
To 0. \'. Eiler, superintendent of the company, we are
indebted for the information contained in this article.
much less than in an average steam plant of the same
capacity .
Table 3 gives the operating, overhead and total costs
TABLE 3. GENERATING COST AT SWITCHBOARD
C. per Kw.-Hr.
Fuel at 3c. per gal
[One chief engineer. $75 per mo 1
Labor | One assistant engineer, $60 per mo. \ $195
I One night engineer, $60 per mo J
Maintenance per month, $926
Supplies, lubricating oil, waste, etc., $20 per month
Operating cost
Overhead: Interest, depreciation and taxes,
on $52,000
$0,247
0.1S23
',•■;
J0.4570
0.5065
Total cost
$0.9635
of power generation. It will be noticed that only three
men arc required to run the plant continuously, but dur-
ing the writer's visit two were carrying on the work, an
So (EL Bio Oil C«
The essential feature of the S. & K. oil cooling ap-
paratus is its high efficiency, which is attained by the
arrangement of the cooling surface and the method used
to pass two mediums through the apparatus, exchanging
the heat through the tube walls in counter currents.
As the thickness of the tubes lias considerable influence
PRINCIPAL EQUIPMENT OF WINCHESTER OIL ENGINE PLANT
No. Equipment Kind Size Use Operating Conditions
2 Engines Diesel... 3-cyl., 16x24-in. Generating units 32-34 deg. oil, air 60 atm., 165 r.p.m Busch-Sul;
2 Generators . Thiee-phase, 00-cvclc 200-k\v Generating units 2300-volt, direct-driven by Diesel engines (Fort Way
2 Generators. . Direct -current ... 11-kw Exciter 125-volt, 600 r.p.m, belt-driven (Fort Way
Three-stage Sxox2JxS-in. 60 atm., belt-driven by induction mo-
10x6Jx3xl2-in... Air for Diesel engines. tors Ineei soil-Rand Co.
7Jxl2-in Pump city water Chain-driven by Fort Wayne synchronous
motoi Goulds Manufactuting Co
Maker
Bros. Diesel Engine I
) General Electiic Co.
) General Electric Co.
Air compressor
1 Pump Triplex .
1 Pump Triplex 7|xl2-in Pump city water D
1 Pump
Triple
llxl2-in Pump city wat"
Dii
i by 40-hp. Nash gas engine Goulds Manufacturing Co.
i by 50-hp. independent motor. . . . Goulds Manufacturing Co.
l by 1-hp. motor Chas. S. Lewis & Co.
2 Meters Integrating
2 Gages Indicating
4 Lubricators. . . . Force feed Thn
Switchboard and all instruments.
accident to the chief engineer bavin
. . Trahern Pump Co.
Measure-soil toengines National Meter Co.
Pressure in air line . Schaeffer & Budenberg Mfg. Co.
Lubricate cylinder of
engine and air com-
pressor .... Geneial Electric Co.
kept him away.
The two Diesel-engine units were started Dec. 1. 1912,
and during the 27 months of operation about $2">0 has
been expended for maintenance. The equipment is. of
course, new. but indications are that this item will not
materially increase for years to come. The superintend-
ent wdio lias charge of the executive work of the company,
and incidentally keeps his eve on the plant, is an experi-
enced Diesel-engine operator, and this has something to
ACTIVE] MEDIUM
on the heat condition, comparatively thin walls are used,
which also make a saving in weight and space.
The tube sheets of the apparatus arc built of metal
in which the tube ends are cast, and therefore the spacing
and the shape of the tube may be so chosen as to give
DETAIL X
ENLARGED
SECT/ON A- A
Details of the S. and K. Oil Cooler
April 27, 1915
P 0 W B R
5C5
the best results in heat transfer, instead of bein§
termined by the strength of metal required for expand-
ing, rolling or inserting of the tube end and spacing
the tubes.
This oil cooler serves the purpose of removing the
heat from the lubricating oils used on bearings and can
be used in am forced lubricating system. The arrange-
ment consists of a continuous circuit in which the oil
is taken by pumps from the bearings and forced through
the apparatus, where it is cooled and then returned to
the bearings.
In order not to block the supply of cooled lubricant
coming from the machine, the hot oil is removed quickly
and rapid circulation is obtained, which is a factor in
cooling the bearings.
The illustrations show an important part in the con-
struction of the cooler. The arrangement of packing
prevents any mixing of the oil and water, and any
leakage will come to the surface and be at once de-
tected. The apparatus requires a small pump for water,
which keeps down initial cost and operating expense-.
The water passages can lie , leaned by removing the cover
without disconnecting any pipe, and the whole tube bun-
dle can be withdrawn to inspect the outside of the tube-.
The oil cooler can lie used in any position, but it i-
better to use it in a vertical one, as the flow of both
water and oil is more uniform, ami any sediment in tin-
oil will settle at the bottom and is easily removed.
The appliance is manufactured by the Schiitte & Kilt
ting Co.. 12th and Thompson St.. Philadelphia, Penn.
Tlhe Specific Heavft svm\<£
IP teasioim ©f Hee
By H. C. Dickinson and X. S. OsBORmE
Results of previous determinations of the specific heat
of ice by certain observers have indicated a rapid increase
in the specific heat on approaching the melting point,
whereas A. YV. Smith* has found the heat capacity of ice
to be practically constant up to temperatures close to zero.
The present investigation has been undertaken with the
object of securing further evidence as to the thermal be-
havior of ice at temperatures near the freezing point and
of obtaining reliable data for the construction of tables
of the total heat of ice and water in the range of tempera-
ture with which refrigerating engineers are concerned.
The measurements were made by means of a calorimeter
of aneroid type, i.e., without stirred liquid as calorimetric
medium. The samples used were from 400 to 4?0 gram-
each. Three were of redistilled water of fairly high
purity, while a fourth, which was distilled directly into
the container, appeared from the experimental results, to
have a much higher degree of purity.
In the determination- oi spei i ic heat it is found that
over the range of temperature covered by the experiments
( — tO to —0.05 deg. <'.). the specific heat S in M-deg.
calories at any temperature 8 of the four ice samples is
represented within the limit of experimental error by the
equation
S = 0.5057 + 0.001863 a — 79.75-
in which the constant I is assumed to represent the initial
freezing point of the specimen and has the following
•Physical Review." 17, p. 193; 1903.
value: Sample No. 1. —0.00125 I; No. 2, 0.00120 /; Xo.
3, 0.00095 I: No. t. 0.0000.5 I.
[The large calorie, or French heat unit, is usually taken
as the amount of heat required to raise one kilogram of
water one degree Centigrade, or from 15 to 16 deg. C.
The "20-deg. calorie" as used by the authors means the
heat necessary to raise one kilogram of water one d(
Centigrade at 20 deg. C. instead of at 15 deg. C. — Edi-
tor.]
From the fact thai the term which represents the de-
parture of the specific heat from a linear function of the
temperature is found to depend on the purity, being less
the higher the purity of the ice, it is concluded that the
specific heat of pure ice in 20-deg. calories may be closely
represented by the equation
S = 0.505; + 0.001863 6.
Determinations of the heat of fusion made upon three
of the samples used for the specific-heal determinations
gave the following values: Heat of fusion of sample No. 1.
79.68 cal.; No. 2, 79.85; No. t, 79.75; mean. 79.76 cal.
The results of a previous investigation at the Bureau of
Standards using different methods to determine the heat
of fusion of ice give, when corrected for the newly found
value for specific heat, a mean value of 79.71 20-deg.
calories.
The mean for the two investigations is 79.75 20-deg.
calories per gram.
For the use of engineers a table of total heats of ice
and water is given, expressed in B.t.u. per pound at tem-
peratures from — 20 to -4-1 no deg. F.
TABLK OF TOTAL HEAT OF
Difference in Total
Heat per Pound
from Ice at t to
ICE AND WATER
Difference
in Total
Heat
per Pound
from
Water
at 32 Deg.
to Water
at t'
lit— h^
B.t.u.
per Lb.
Ice at Water at
32 Deg. 32 Deg.
Haz— Ht h3^-Ht
t B.t.u. B.t.u.
Deg. F. per Lb. per Lb.
— 20 23.8 167.2 -32 0.0
— IS 22.9 166.3 34 2.0
—16 22.1 165.5 36 4.0
— 14 21.3 164.7 38 6.0
— 12 20.4 163.8 40 8.1
—10 19.6 163.0
— 8 is. 7 162.1
— 6 17.9 161.3
— 4 17.0 160.4
— 2 16.1 159.5
158.6
15.2
14.3
13.4
12.5
11.6
10.7
9.7
155.9
155.0
154.1
153.1
1 5"2 2
151.2
150.3
149.3
14S.4
147.4
146 4
145.4
144 4
A Monster Aqueduct — The aqueduct conducting the waters
of the Owens River, at Los Angeles, is said to be the largest
in the world. It is designed to deliver a minimum of 258,000,-
000 gallons of water daily into the San Fernando reservoir, 25
miles northwest of the city. No pumping plant is required, as
the source of supply is several hundred feet above the city.
The water will furnish a great amount of power — 7000 horse-
power is anticipated — for electric lighting and other purposes.
The total cost of the water-works will be $25,000,000, and the
installation of the power plant w'ill cost approximately $5,000,-
000 more. — "Exchange."
4 2
10.1
44
12.1
46
14.1
48
16.1
50
18.1
52
20.1
54
22.1
56
24.1
58
26.1
60
28.1
62
30.1
64
32.1
66
34.1
6S
36.1
7n
3S.1
7°
40.1
74
42 1
76
44.1
7v
46.1
SO
4S.1
82
50.1
84
52.1
86
54.1
88
56.1
90
58.0
95
63.0
100
6S.0
566
i'<nv ee
v.. i. m. v.. i;
dlgwsAy
T^arlbiinK
. .mi turbine of the Ridgway Dynamo & Engine
Co. is of th>' Rateau type ami is built under license from
Professor Rateau ami C. 11. Smoot, of the Rateau-Battu-
; Co., the American representatives of the pro-
fessor. As our readers know from previous descriptions,
the Rateau is a pressure-stage turbine, ami is shown in
conventionalized section in Fig. 2. Steam is expanded
through the set of nuzzles at the left, impinging upon the
: wheels EE, the engraving showing some of the
blades in section. The pressure drop in passing through
each set of nozzles is sufficient to generate only a ve-
locity which can lie practically abstracted by the single
row of buckets upon which the steam impinge- in each
stage.
With the first few pounds of drop in pressure the ve-
locity generated is great in comparison with the im I
one-third of that which would be generated by effecting
the expansion in a single stage, 9 stages will be required:
if one-fourth 16 stages; etc
Fig. 1 shows this type of turbine, as built by the Ridg-
way Dynamo & Engine Co.. connected with a 375-kw.
alternator at the power plant of the Cascade Coal & Coke
Co., at Tyler, Perm. This is a mixed-pressure machine
ned for high-pressure steam of L25 lb. gage and ex-
haust steam of lb Hi. absolute pressure ami runs at 3600
r.p.m. The low-pressure steam i- the exhaust from re-
ciprocating engine units, pumps, etc. By the installation
of this unit tin' capacity of the power plant was increased
66 per cent, without any increase in the boiler plant, and
with an actual decrease in the amount of coal consumed
over the previous operating condition.
Fig. :; i- a section of the regular high-pressure type.
Fig. 1. 3T5-Kw. Ridgway Tukdu-Deivex Fxit at Plaxt of Cascade Coal & Coke Co.
of volume, so that a smaller nozzle section is required to
pass the same weight of steam. It is not until the lower
pressure reaches about 58 per cent, of the higher that the
volume begins to increase faster than the rate of flow
necessary to take care of it, and the area of the nozzle
3es. As the pressure-drop in
the Bateau turbine for the ordinary condition is well with-
in this range, the nozzles are converging. Although the
steam expands in going through them, the outlet is
smaller than the inlet, as shown in Fig. 2. After having
its velocity reduced by passing through the moving
blades, is discharging into a second series oi
nozzles, where it is further expanded, and so on until
it is discharged to the condenser. The number of si
required for complete expansion varies inversely as the
square of the velocity. If the velocity per stage is to be
i enters at A, passes through seven sets of nozzles
and bladed wheels having passages of ever-increasing
tion, and is finally discharged into the exhaust passage
at the right. There are. therefore, eight different pres-
sures existing in the machine, counting those of the steam
chest and the exhaust passage, and the chambers contain-
ing these different pressures are divided by heavy parti-
tions. But whatever the pressure in any chamber, it is
the -nme on both sides of the wheel revolving in each
chamber, so that, with the symmetrical buckets used, there
is no end thrust, and all that is needed to keep the shaft
in place and the nozzles and blades in their proper rela-
tions are the few thrust rings RRR in the bearing of the
low-pressure end.
Pig. ■': -how- the partitions in section, and it will be
seen that they are heavier and more securely packed where
April 27, 1915
POWER
56?
the shaft passes through them, in the caw of the high-
pressure stages to the Left, tkan in those at the right,
where the pressure differences are less.
As the pressure is the same all around the wheel,
critical Bpeed, and'on which are turned, the thrust rings re-
ferred to. The wheels are machined from disks of flange
steel, and arc keyed upon ther shaft, .being separated from
each other by steel collars which run against the packing
in the diaphragms which divide the stages. The buckets are
machined from solid bars, the material selected, usually
bronze, being adapted to the particular service for which
the turbine or stage is designed. They are made in the
Fig. 2. Conventionalized Section of Nozzle and
Blading
there is no tendency for the steam to leak by it, and the
clearances, both longitudinally, as at .1 and B in Fig. 2,
and radially, as at 0 in the same figure, may be com-
fortable and generous, the axial clear-
ance even in small machines being ^
and the radial y2 in. In large turbines
these clearances are as much as % and
1 in., respectively.
The rotating element consists of a
high-carbon steel shaft of such diam-
eter that its normal speed is below the
Section and Details of Governor
two styles. Fig. 7, the smaller being secured by rivets
through their shanks, so placed as to retain the maximum
possible section, the larger with bulb ends which are
driven into slots in the periphery of the wheel and peened
solidly into place. Each bucket of either type carries its
own shroud and, when assembled in the wheel, is in rigid
contact at its outer end with the adjacent bucket, afford-
ing mutual support against vibration and damage.
The easing, the heads, and the diaphragms which sep-
arate the stages, are split horizontally, the top halves of
the diaphragms being attached to the upper half of the
Fig. 3. Longitudinal Section Ridgway-Rateau Steam Turbine
568
POW EB
Vol. 41, No. 17
casing and lifting with it. The steam and exhaust con-
- are made to the lower half, so that they need not
be disturbed when the turbine is opened. The nozzles
with small area for the initial stages are machined east-
ings bolted into place, as shown in Fig. 5. In the later
stages the blades forming the nozzles are cast in place in
the diaphragm and extend all or part way around its
periphery, as shown in Figs. 6 and ;.
throttle valve through the lever B. Additional tension
may be put upon the governor through the bandwheel E,
in Fig. 3. The thrust which is interposed between the
rlyball governor and the valve gear is provided with two
ball hearings to take the direct thrusl as well as any side
thrust due to lack of perfect balance. The usual au.xil-
Fig. 5. Cast Nozzles
For the high-pressure boxes and the diaphragms the
packing is made of carbon blocks. Fur the low-pressure
boxes a water impeller is used, so arranged that it does
not prevent the adjusting of the clearance between the
stationary and revolving elements.
The governor is mounted directly upon the end of the
main turbine shaft, as shown in Fig. 3. It is shown more
in detail in Fig. 4. The actuating weights consist of the
longer amis a, of three bell-crank levers fulcrumed upon
tool-steel knife-edges, the relative location of which is
shown in the detail drawing in the lower right-hand cor-
Fig. v>. C vst-In Nozzles
iary governor, which shuts the turbine down automatical-
ly when the speed exceeds a predetermined limit, is in-
cluded. The bearing lubrication is by the gravity-pres-
sure system with circulating pump, filter and cooler, or
b\ iin-- oiling with water-cooled bearings.
The turbo-alternator, also made by the Ridgway com-
pany, is of the revolving-field type, with radial slots for
the field coils. In the process of stacking the core num-
erous air ducts are provided, insuring a more thorough
ventilation than is possible with a solid core. Generous
ventilating ducts are also provided in the stator, and an
Fig. T. Full Peripheral Nozzle
ner, the parts being similarly lettered. The small projec-
tion- shown at the end of the lever in the section are buf-
fers. A- the weights fly outward the member b. upon
which the other arm of the bell crank presses through
tool-steel cup points. i> moved to the left against the ten-
sion of the spring, turning the larger bell crank A around
the fulcrum C and communicating its movement to the
Fin. s. Pull Set of Moving Bladejs
outside lagging directs the heated air to an outlet at the
bottom. Direct-current turbo-generators arc carried di-
rectly upon the turbine shaft without the interposition
of gearing, the strength necessary to resist the high cen-
trifugal fori c being secured by holding the winding which
is made of bur copper wedged into the slot by heavy bronze
rings.
April 27, L915
P 0 W B u
569
This meter, Fig. 1, is designed for the measurement of
ii used in buildings heated from an outside source.
by weighing the water of condensation. It can also be
used lor measuring various liquids where a gravity dis-
charge permits, hut it will not operate under pressure.
The meter consists essentially of a tilting copper bucket
which measures the condensation. When sufficient water
Fig. 1.
Interior of the Simplex Coxdexsatiox
Meter
has run into one side to overbalance it, the bucket tilts,
discharging the contents into the meter case, and then
through the outlet pipe to the return system or to the
sewer. In tilting, the empty side i^ brought to the filling
position. The tilting action is repeated until water ceases
i" tlow to the meter.
The bucket is mounted on a shaft that is supported on
roller or ball bearings on the outside of the meter case.
In the bottom of the case are dashpots which remain
Fig.
Auxiliary Bucket ix Tiltixg Bucket
filled with water and serve as cushions to prevent
objectionable noises in the operation. A recording
dial indicates the number of pounds of Mater that have
passed through the meter.
To prevent waste of condensation when the tilting
occurs, an auxiliary bucket has been arranged to catch
the water discharging from the inlet nozzle. This is
shown in Figs. 2 and 3. Referring to Fig. 2, the open
spaces in the main bucket are for the inlet nozzle to
discharge into the empty half. The auxiliary is made
with two sections, each discharging to opposite sides of
the main tilting bucket, which, when one side contains a
certain height of water, starts to tilt to the disi h
position.
Fig. 3 shows the operation of the auxiliary in catching
the water which would otherwise be wasted between the
point of beginning oi the bucket dump and the time when
the center partition of the main bucket passes under the
nozzle. During this period the water i- diverted to the
empty side.
The auxiliary bucket cannot cut off the total amount
of water which would he discharged during the complete
tilting movement. It doe-, however, intercept a large
percentage of this waste, deferring to Fig. :;, the heavy
arrows marked .1 indicate the hulk of water entering the
main bucket. As s i as this has received its full quota
of water, it tilts ami discharges, and at that instant the
edge of the auxiliary bucket passes under the nozzle open-
ing and the water passes into it, as shown by the arrows
B, thence through a hole in the middle partition to the
other side of the bucket, where it is received and weighed
on the next discharge. The operation when getting under
way for discharging is necessarily slow, and while gather-
Fir;. 3. Diagram of the Tiltixg Bucket
ing momentum the auxiliary bucket cuts off the water.
After the bucket has acquired momentum and is traveling
at a rapid velocity, only a .-mall amount is wasted, owing
to the fact that it passes over to the other half of the
auxiliary and back into the side which has already
discharged.
Tests of these meters show that this very simple device,
which requires no actuating mechanism, takes up and
records the bulk of the waste water which would other-
wise have entered the bucket after it had started to dump,
and for which, previously, corrections had to be made in
the testing.
This meter is manufactured by the American District
Steam Co., North Tonawanda, X. Y.
v
Steam Separators with receivers of liberal proportions
should be used near engines, to provide a reservoir of steam
near-by and to minimize pulsations in the lines.
X
An Experience in Seeking Help, cited by Charles T. Porter
in his "Engineering Reminiscences." is more typical of former
times than the present.
"I called upon a friend who was a great mathematician and
tne editor of a series of mathematical books then largely used,
and stated my trouble in calculating the centrifugal force and
momentum as applied to my governor. He illuminated the
subject to me as follows: 'You seem to be a persevering
young man; keep hard at it and you will solve the difficulty
by and by.' "
5T0
r u w b k
Vol. ii. No. i;
The fact is established, not only by numerous ami re-
peated tests, but by everyday practice, that the uniflow
engine requires only about the same amount of steam as
a compound engine. There are others besides our corres-
pondent who cannot see
how this can be. Here is
one way of accounting
for it.
A 100-per cent, engine,
i.e.. an engine that could
turn into work all the
heat set free by working
steam between 150 Hi
gage, 100 deg. superheat,
and atmospheric pressure,
would run on about 13i/o
lb. of steam per hour per
i.hp. The best actual en-
gines require 17 or 18 lb.
If an engine used 18 lb.
per hp.-hr., it would de-
velop Vis °f a hp.-hr. per
pound of steam. A horse-
power-hour is equivalent
to 2544.65 B.tu. Hence,
the engine converts
2544.65 -=- 18 = 141.4
of the 1252 B.t.u. which
is brought into it with
each pound of steam into
work.
If the engine had no
losses it could run on 13.5
lb. per i. hp.-hr., and con-
vert
•2544.05 -^ 13.5 = 188:5
B.t.u.
What becomes of the
difference between this
and the 141.4 B.t.u. con-
verted by the best actual
engines and the much less
converted by the less effi-
cient types ?
The heat which is car-
ried into the engine cylin-
der by the steam can get
out in only three ways:
Radiation;
Conversion to work;
In the exhaust.
And it has got to get out
as fast as it goes in, or it
will accumulate in the cyl-
inder and melt it down.
The radiation loss from
a well lagged cylinder is triflin
Jkl£
a large part of the forward stroke, and given out
to the exhausting steam throughout the entire re-
turn stroke or until, by compression, the tempera-
ture of the inclosed steam equals that of the walls.
Whatever o-0es to nullify
.1// incredulous correspondent writes:
I studied with interest Die article under this liead-
ing in Power of Nov. 17, and a* I hare written be-
fore in regard to this engine. I do nut see how it can
show good economy.
Regardless of the test data given (which are un-
doubtedly correct figures), there remains much that
should be explained. Take the figures on page 702
in regard to compression; it is found tit, it with 26-in.
radium there will be about 38 lb. compression with
•• < learance of 5 per cent. This dues not seem so bad
at first thought, but it is bad. for figuring along the
same line. I find that at half stroke there is a back
pressure of IS lb. — i.S lb. above atmosphere. Imag-
ine producing a 26-in. vacuum for an engine that is
in direct connection with it for only T\7 stroke, and
at half stroke is exhausting or. what is of the same
effect, has a back pressure over 3 lb. higher than it
would have running noncondensing ! In the several
iirttiles I hare seen regarding this engine, the claim
is made tliat the exhaust steam not returning through
the cylinder keeps a more even and hotter tempera-
ture. So far, in my experience it never has been ex-
plained to me why steam is hotter at a given pressure
traveling in one direction than in some other. If the
engine exhausts down to 2 lb. the temperature will
be around 126 degrees, regardless of whether it de-
parts by the back or front entrance. If not. why not f
Then again, there is some condensation in any steam
cylinder mid. us is well known, this portion of the
impulse charge sticks more or less U, cylinder walls
and, in general, lags behind the portion that remains
steam. Then it would seem that a large percentage
of this near water will not get out of the exhaust, but
will remain to be compressed, for that -»{1 of stroke in
the uniflow cylinder. Perhaps this lends to high
economy. If so, why?
I note this particular engine lias steam jackets.
This, of course, will increase I he economy of am/ type
of cylinder, but down home it is the custom to take
lite cost of maintaining this steam jacket. This takes
us sort of back to the coal heap, which, after all, is the
item that most interests us of the monkey-wrench
and overalls. We do not write for argument, we wish
to learn. That is why we take Power. So. if the
editor and the higher professors will bear with us and
show us just how some, nice things are done and why,
ire will be truly thankful.
It is evident that most
of the unutilized heat escapes in the exhaust.
How does it get there?
It is absorbed by the containing surfaces, the cylin-
der walls, port surfaces, cylinder, and piston heads
when the steam is hotter than they are. i.e.. through
or to discourage Ibis trans-
fer of heat between the
working medium ami the
containing surfaces, tends
to reduce this bypassing of
the heat from the hot to
the cold side, from the
steam chest to the exhaust,
without doing work, and
hence tends to increase
the efficiency of the engine.
Suppose a cylinder could
be so thoroughly jacketed
on heads and on barrel
with steam so hot that the
inside skin of the contain-
ing surfaces would be as
hot as the entering steam.
When the steam came in it
would remain in a vapor-
ous or gaseous condition,
instead of some 20 per
cent, condensing upon the
cooler iron, as in the usual
ease, and it would retain
its initial condition until
cutoff occurred and expan-
sion commenced. Then it
would commence to cool
and to absorb heat from
the containing surfaces.
Perhaps it has some super-
heat in its initial condi-
tion, so that it will not
commence to condense im-
mediately, or until the
temperature has been re-
duced by expansion enough
to use the superheat all up.
Superheated steam, dry
steam, is a very poor ab-
sorber of heat. The heat
from the cylinder head can
radiate or "shine" through
it, as the heat from the
sun can radiate through
the air without warming
it up much. It is only
when the sun shines on the
rocks, and other substances
which will readily absorb
its heat, and then the air passes over them and picks the
heat up by convection, that we get an energetic heating
effect. The mere shining of the sun through the air
heats it hut little, as witness the temperature at elevations
where there is little solid material, as compared with the
exposure, to absorb and radiate the heat.
April 37, 1915
P 0 W E R
571
Under these conditions it can readily be conceived that
even after the expansion has proceeded until the steam is
below the saturation point, or even if there is initial con-
densation, the film in immediate contact with the hot sur-
faces gets dried out and superheated. Then the absorption
of heat from the surfaces stops or becomes very slow.
The effect is analogous to that produced when a stra-
tum of air gets around the cooling surface in a con-
to the point where it again covers the central port — usu-
ally about one-tenth of the stroke. When the exhaust port
is covered there is the volume of the return stroke yet to
be completed, pins the clearance volume, full of steam
of the exhaust pressure; that near the piston probably at
a temperature corresponding to its pressure, that in con-
tact with the hot bead superheated considerably above
that temperature. As the compression proceeds the tem-
denser, or when, in a boiler with poor circulation, the
-nam does ii. it gel readily away from the heating surface,
or when, in a high vertical radiator, an inside pipe is so
smothered that the already heated air hugs it instead
of getting away and allowing other and cooler air to come
up and be heated. So long, in the case of the engine, as
this blanket of highly heated steam can be kept against
the hot surfaces, there will be little transfer of heat to the
contents of the cylinder, to be carried off in the exhaust.
Now, in the case of the counter- flow, or usual, type of
engine, where the exhaust and the steam valves are both
at the same end of the stroke, there comes, when the re-
lease occurs, an immediate rush of the steam backward
toward the hot head, in a struggle to get out at the open
exhaust port, as shown in Fig. 1. This steam, even if it
were superheated to start with, has become cool and moist
by expansion and the conversion, with consequent con-
densation, of more of its heat into work than it could spare
and remain dry. The protecting blanket of superheated
steam is swept away from the hot surfaces of the entering
end, and the cold wet steam impinging upon these sur-
faces absorbs heat from them by evaporation and con-
vection to be carried uselessly into the exhaust or to make
more work for the condenser. In a single-valve engine,
where the same port is used for inlet and exhaust, even
the surfaces of the port through which the hot entering
steam must come are washed and cooled by this heat-
absorbing mixture of low-pressure steam and water.
With the uniflow, or central-exhaust, engine, Pig. '.'.
there occurs no such reversal of flow. When the piston
passes over the central port the steam is released from that
end of the cylinder, the hotter steam at the head or jack-
eted end simply expanding and pushing the cooler wetter
steam before it. The protective blanket on the cylinder
head and the hot end of the cylinder is not swept off, but
remains intact, and all the heat which is carried to the
exhaust is thai which the steam in the exhaust end of the
cylinder can pick up in sweeping over the cooler piston
head and the walls near the exhaust port, as it is pushed
out of that port by the expansion of the rest of the steam
from the pressure at release to that of the exhaust or con-
denser, and by the backward movement of the piston up
perature rises with the pressure, and there will be some
condensation against the piston head, which is now ab-
sorbing heat that will be carried off in the next outrush
of exhaust, but when the compression stroke is completed
the clearance will be full of steam of practically the ini-
tial pressure, the cylinder head and clearance surfaces
will be good and hot and the piston head as hot as it could
get by taking heat from the compressing steam, so that
the entering steam is received upon surfaces of about its
own temperature and initial condensation much reduced.
Our correspondent, in saying that he would not care
Fig. ;;
to maintain a condenser which was in communication
with the cylinder for only one-tenth of the stroke, loses
sight of the fact that the diminution in , the back pre
endures throughout the stroke by reason of the lower
initial compression pressure. Fig. 3 will make this plain.
The full line represents the counter-pressure running
noncondensing, the dotted line condensing, the exhaust
port closing when the return stroke is one-tenth comp
in both cases. The diagram ought also to make plain to
our correspondent that the method by which he computed
the absolute back pressure at half stroke to be IS lb. ab-
solute has something the matter with it. The steam
used in the jackets is included in the steam rate- reported.
572
POWER
Vol. 41, No. IT
ator N©l:
By Francis H. Davits
SYNOPSIS — Motor noises classified as to the na-
ture of their causes — namely, magnetic, ventilating,
and mechanical. How to detect the cause and the
remedy to be applied.
Primarily, the noises arising from the operation of any
machine may be divided into two classes — those directly
transmitted by the air and those transmitted through the
ground and walls. Air-transmitted noises may arise
from several causes, but in the case of electric motors
they are usually magnetic, being due to vibration of arma-
ture teeth and laminated pole shoes under a high-fre-
quency alternating field. Such noises are characterized
by a penetrating hum or shriek and are difficult to cure.
Their intensity depends upon the field strength, the fre-
quency of reversal, the form of the core and pole stamp-
ings, and the manner in which these are put together.
Designers appreciate the importance of reducing mag-
netically generated noises to a minimum, and the follow-
ing points out what experience has proved necessary to
this end.
Magnetic Noises
It is inadvisable that the pitch of the armature slots
at the circumference exceed % in., as it is found that wide
and open slots produce oscillations of the field flux which,
acting on the laminations, cause vibration and consequent
noise. Where the slots are wide, iron wedges may be in-
serted, the action of which is to spread out the flux and
allow the teeth to enter and leave the field more gradual-
ly. The same effect is secured in many armatures by slant-
ing the slots instead of
arranging them parallel
with the shaft axis ; and.
with a similar object,
pole shoes are sometimes
constructed with their
horns on the slant as
shown in Fig. 1, which
allows the core teeth to
enter and leave the field
gradually. A noisy ma-
chine may sometimes be
cured by this alteration
to the poles, which is
comparatively simple
provided the poles are of the solid and not the lam-
inated class. It is generally understood that for noise-
less running the polar horns should be well rounded
and tangential to the armature (Fig. 2) instead of em-
bracing it closely at the tips, the object being to reduce
the intensity of the field at the extremities.
Weakening the field by increasing the air gap is another
method of minimizing magnetic noise, but this results
in a higher speed for an equal output.
Laminated poles are certain to give rise to noise unless
the laminae are so tightly built up that vibration is im-
possible. Furthermore, the rivets securing the lamina-
tions must be as close as possible to the outer edges, par-
Fk
ticularly those passing through the horns, as this will ren-
der them less liable to vibration arising from the rapidly
changing density of the magnetic flux as the teeth of the
armature core pass the horns. This effect is at a maxi-
mum when the number of slots in the armature core is
small, because then the magnetic disturbance will be
greatest. Therefore, the designer allows for as many
slots as possible, taking care also that they are so pitched
that one does not leave the pole at the same time as an-
other arrives under it; such spacing will cause maximum
swinging of the flux and consequent noise. In other
words, the length of the
pole face measured on
the arc should not be a
multiple of the slot
pitch.
Ventilating Noises
Sei 'Mid to magnetical-
FiG. '.'. ly generated noises are
those arising from the
ventilating arrangements. The churning of the air
by revolving parts and its flow at high velocity through
the end-shield openings set up a deep noise compar-
able to that of a fan. It is not very objectionable, but
may be lessened by partially closing the vents in xhe
end shields, although this interferes to some extent with
the ventilation. It is important that there be as few
projecting parts as possible in both the field and arma-
ture as these act as vanes and propellers.
A more objectionable noise is that caused by air passing
at high speed through ventilating ducts. It is often diffi-
cult to distinguish this from magnetic noises. This
point may be settled, however, by running the machine
up to speed and then switching off the current. It is al-
ways possible to modify ventilation noises by reducing
the speed, and in some cases a small reduction will be
effective.
Mechanical Noises
Noises arising from mechanical causes are usually at-
tributable to faulty design, poor workmanship, or wear.
An armature that is out of balance will set up heavy vi-
brations and an annoying sound that will travel some
distance through the framework or vails of the building,
unless special steps are taken to isolate the machine.
Bearing wear, also, will result in an armature losing its
true concentric position with regard to the poles, and
this sometimes causes a heavy knock. The remedy for
an unbalanced armature is, obviously, to balance it care-
fully, noting whether it is a case of a sprung shaft and
not an original fault, or if the bearings are worn and
require replacement. When the bearings are in good con-
dition and it is found that the armature is not truly con-
centric with the fields owing to bad assembling, this can
often be rectified by the insertion of liners or their with-
drawal from between the poles and the yoke ring, unless
the field be one solid casting. In the latter case liners
can sometimes he placed under the bearing pedestals.
Another likely cause of knocking is a loose part, and it
April
1915
i'o w )•: i;
573
is often necessary to overhaul the machine thoroughly in
order i" locate it. Motors working under arduous condi-
tions of frequent reversal are apt to develop a loose
armature core owing to wear of the keyv a \ .
It, is well known that sound is carried by solid bodies
better than by air; consequently, a noisy motor may cause
annoyance at a considerable distance, particularly in
the case of buildings of steel structure. In such eases the
only remedy is to isolate the machine from the floor, wall
or ceiling upon which it is fixed. There are numerous
ways of doing this, one particularly good one being the
placing of felt under the bedplate, with washers of a
similar material inserted under tin1 heads of the holding-
down bolts. It is also well to hush the holes in the bed-
plate with similar felt, for if the holts touch anywhere
they will act as conductors. It should be borne in mind
I hat felt of the ordinary type, such as that used for roofing,
is quite useless and cannot.long retain any sound- or vi-
bration-absorbing properties that it may originally possess.
Special felts are made for this purpose, sometimes with
cork and rubber inserts.
Minor Noises
Among the minor noises are those arising from the com-
mutator and brushes. A high liar in the commutator is
a not infrequent cause, hut the hissing common with
many motors is due to the brushes being either too hard,
improperly bedded, tight in the boxes, or adjusted at
the wrong tension. These faults are easily located ami
call for only obvious remedies. The motor itself is not
always the greatest sinner, and a noisy installation may
often he quieted by proper attention to the belting or
other form of transmission used. The flapping- of a slack
belt is easily remedied, though the noise set up by a slip-
ping belt may require more drastic treatment. Should
the slip be due to overload a larger belt and, perhaps,
larger pulleys must he provided; or if it arises from too
small an arc of contact the centers must be increased or an
idler pulley employed.
There are also, of course, the usual remedies of wooden
or paper pulleys and various dressings having for their ob-
ject better adhesion of the belt to the pulley. For quiet
operation belts should not be run against the joints and
metallic fasteners should not be broader than the belt
nor project through to the running side. Where chain
drives of the "noiseless" type are installed proper atten-
tion is all that is required to enable them to justify their
name. If, however, they are not properly erected and
are allowed to become too worn, dirty and dry, a certain
amount of noise is inevitable. Spur gearing is a type
of transmission which frequently gives rise to much noise.
and for the best results the wheels must he truly cut, well
lubricated ami correctly distanced. The last is especially
important, for if the wheels engage too closely or are
too far apart they will cause objectionable noise. Fiber,
paper ami rawhide pinions are to be recommended and
provide the best solution of the problem of quiet spur gear-
l p, Iliiiu mid Duplicate Steam-Pipe Systems should be
indulged in sparingly, especially if much extra length of
pipe is involved, or should be so arranged that unused sec-
tions can be shut off. This applies, of course, to exaggerated
and complicated systems designed to meet every possible
contingency. There can be no objection to a complete loop
where the boilers and engines are set practically parallel to
each other, so that the headers may easily be connected at
each end.
New Commutator Luishk'Ant
To a young man was assigned the duty of caring for
the motor in a small manufacturing concern. It had
been the custom to rub the commutator with a cloth
dampened with thin oil after the power had been shut off,
while the armature was still rotating. One evening the
-wah cloth was missing, but a bottle of shellac and a
cloth were handy, so he used that on the commutator. In
the morning the motor refused to start at all, and an in-
spector was sent for. He found a finely polished commu-
tator, but the brushes were all stuck tight and had to be
pried loose. — R. A. Cultra, Cambridge, Mass.
A Parallelism Indicator
A glass company in western Pennsylvania had five ver-
tical gas engines of about 600 hp. installed, but brought
suit against the builders, claiming that the engines were
not as guaranteed. "\Ye have one of the same kind, run-
ning with the generator in parallel on a 23,000-volt high-
tension line. The engine builders and the glass-company
officials visited our plant to see the engine and get our
reports. After we had explained that the generator was
operated in parallel with the main plant about 100 miles
away, one of the glass-company officials watched the
make-and-break igniters working, and then asked the en-
gineer if the engine was in parallel every time the thing
clicked. — R. G. Curren, Jr., Kit /aiming, Penn.
An Improved (?) Boiler Joint
Fig. 1 shows the original longitudinal triple-riveted
joint on the shell of a boiler, with an efficiency of 76.5
per cent. The Chief Engineer (?) wanted to have a
higher working steam
pressure in the plant
than he was carrying.
He had heard of
boiler joints being
made stronger by
having a cover strap
and two additional
rows of rivets put in,
so he got busy and
ordered the change
made on his boilers.
He cut out all rivets from the original joint and had
a cover strap fitted. He had one row of rivets added
on each side, as shown, Fig. 2. After all the inconven-
ience and cost of labor due to this change, he was in-
formed the joint bad exactly the same efficiency as before.
The weak point of the original joint was the net section
of plate between the outer rows of rivets. In his change
be added one row of rivets on each side of the original,
but spaced them the same distance apart as the first
three rows were. The three center rows were changed
from single to double shear, hut there still remained the
two outer rows in single shear, and the net section be-
tween the outer rows had the same value as in the orig-
inal joint. Therefore the joint efficiency was the same.
If this fellow had asked for proper advice he could
have been put right and saved dollars for his company
and trouble for himself. The boilers are still in use,
but at no higher pressure. — J. A. Sawyer, Phila., Fcnn.
©
r
o
o;
0
Q
1©
Q
O!
0
Q
:©
Q
o!
J
....
©
_i® 1
Attempt at Strengthening
Joint
574
POWER
Vol. n, No. 11
By T. PI. Reabdon
A high percentage of C02 in uptake gases indicates in
a general way a high degree of efficiency in the process of
combustion, but it may not he so generally known that
an increase or decrease in this gas indicates the char-
acter of the coal or fuel.
Theoretically perfect combustion is impossible whether
conducted with laboratory refinement or with boiler-room
methods. By perfect combustion it is understood that
the agents that enter into the reaction are present in
quantities necessary to yield the final products of combus-
tion with no excess of any reacting element. It is clear
that if a sample of pure carbon could be burned to com-
pleteness with the theoretically necessary quantity of
oxvgen, the sole product of combustion would be C02 and
the percentage of this compound in the combustion prod-
ucts would be 100. Further, if a sample of fuel con-
sisting of both carbon and hydrogen were burned under
the same conditions the products of combustion would be
CO„ and water, and if a sample of these products were
drawn into an aspirator for subsequent titration with
caustic potash it would be found that the water present
as aqueous vapor in the condition of superheated steam.
would condense, its volume becoming practically nil. This
removes it from the sample, leaving only C02 as the gas
that later will be drawn into the burrette for measure-
ment.
When combustion is supported with the theoretically
necessary quantity of air, certain differences will be ap-
parent. Air consists of a mechanical mixture of oxygen
and nitrogen, the proportions by volume being usually
taken as, oxygen. 21 per cent.; nitrogen, 79 per cent. If
the complete combustion of carbon could be carried out
with the theoretically necessary quantity of air, the per-
centage of C02 in the stack gases would be the same
as that of oxygen in the air. viz.. 21 per cent. This i- a
limiting high mark obtainable only with ideal conditions
and with a combustible consisting entirely of carbon.
As soon as experiments are made with a fuel consisting
of a mixture of carbon and hydrogen, the percentage of
CO., in the products of combustion will dimmish, even
with perfection in the processes.
Carbon unites with oxygen according to the equation
C + 02= C02; L2 4- 33 = 44.
Hydrogen unites in a similar way with oxygen as follows:
2 H2 + 0, = 2 1LO; 1 + 32 = 36.
An inspection of the equations shows that 12 parts by
weight of carbon require 32 parts by weight of oxygen
for perfect combustion, or 1 part by weight of carbon re-
quires 2% parts of oxygen. For hydrogen we find that
2 parts by weight require 16 parts by weight of oxygen.
or 1 part hydrogen requires S parts of oxygen. The
weights and volumes of air required for carbon comsump-
tion and for hydrogen, respectively, are in the same pro-
portion, i.e., weights being equal, hydrogen requires three
times as much oxygen or air for its combustion as car-
bon does.
Each per cent, of hydrogen content in the fuel, there-
fore, reduces the percentage of C02 0.21 per cent., because
in combustion hydrogen yields no C02 and dilutes the
stack gases by introducing three times as much inert
nitrogen as would accompany the oxygen used in case the
hydrogen content of the fuel had been carbon.
It is obvious that as hydrogen increases in amount in
the fuel the percentage of CO. must diminish, and that
if the hydrogen became equal to 100 per cent., the per-
centage of (()._, would be 0.
A study of this subject is interesting, and will mate-
riallv aid in making clear the significance of C02 in the
stack gases and the extent to which its presence is in-
fluenced by various factors.
Siiradl Moist
Engineers will find the Canton portable floor crane and
hoist a convenient, and in some plants a necessary appli-
ance Eor handling heavy work which would require several
men and much time to perform by hand.
The crane bed is fitted with two rear-bearing and two
Portable Floor Cbane and Hoist
guide wheels. The latter are provided with a tongue so
that the tool can be pulled from one part of the plant to
another, the same as if the load were on an ordinary truck.
The crane arm and its windlass are bolted to the body.
In the engine room the contrivance will be found con-
venient for handling cylinder heads, heavy pillar-block
caps, steam pumps or any other apparatus which would
require jacking, especially where an overhead crane is
not available.
This hoist is manufactured by the Canton Foundry &
Machine Co., Canton, Ohio.
8
A Fine Engine-Room Performance — The sinking of the
German cruiser "Xiirnberg" by the British cruiser "Kent,"
in the action off the Falkland Islands, was due, primarily.
to the remarkable work done by the engine-room and stoke-
hole staffs of the "Kent." The trial speed of the "Kent."
which was an eleven-year-old ship, was 'liV* knots, and it
looked as though her attempt to overtake the 23V4-knot
"Xiirnberg" would be fruitless. But in response to the cap-
tain's appeal, the engineering force managed to push the
speed up to 24 knots per hour, or one knot more than the
ship had ever steamed since she first went into commission,
and gradually she overhauled and got within range of the
enemy. — -"Scientific American."
April
L915
P 0 \Y E R
A. Btriieff IHn story of (lib©
TIhe5fEim©siraefteB*
By \Y. S. Atchison
In looking at a thermometer — apparently a glass tube
containing either quicksilver or a colored liquid and
having some sort of a scale — one is not apt to realize the
thought, skill and research it has taken to bring this
simple, yet universally accessary article to its present
state. For many centuries scientists have worked in an
endeavor to perfect it, but only during the pas! Eorty
years have they found out all the details necessary to the
manufacture of a more or less perfect article.
Many people are credited with the invention of the
thermometer, Drebble, a Hollander, being referred to more
than any other; but to Galileo Galilei, the laurels should
probably be handed. According to history it seems that
about 1592 he invented at Padua an instrument described
as "a alass containing air and water, to indicate changes
and differences in temperature."'
With the idea started, the Grand Duke of Tuscany in-
vestigated this invention and improved it more or less
between 1030 and 1640. The original thermometer con-
sisted of a glass tube about 16 inches long with a hollow
ball, or bulb, at the end. The whole was heated until the
air inside became rarefied, when the open end was placed
in water, the tube being kept upright. As the air in the
tube cooled or contracted, the fluid (water was originally
used) rose to a certain point and any subsequent changes
caused the level of the fluid to be either elevated or
depressed.
This was used by Sanctorius as a "heat measure," or
fever thermometer. It is on record that he had his patients
hold the top of the thermometer so the level of the fluid
would be arrested at a point equal to the temperature of
the person holding it. A point was undoubtedly deter-
mined by a normal, healthy person beforehand, and it
is reasonable to assume that Sanctorius drew his de-
ductions by noting the distance above or below this
"normally healthy" person.
Before ten years had passed the Grand Duke of Tuscany
had carried out his idea of first partly filling the tube with
alcohol and closing the open end, thus sealing it and
excluding the air. Realizing that the level of the liquids
in these various instruments meant nothing, pupils of
Galileo sought to make a scale of temperature and melted
onto the tube of their thermometers small glass balls about
the size of a pin's head, the zero of the scale being the
point to which the liquid fell in a freezing mixture of
salt and water.
At one time the bright minds of Europe decided that
the freezing point of liquids varied to such an extent that
it could not be used as a test point, and suggested taking
the temperature in a cave cut straight into the bottom of
a cliff fronting the sea to the depth of 130 ft., with 80 ft.
of earth about it.
About 1662 Hooke, placing his instrument in freezing
distilled water, marked "zero" at the top of the column
of spirit after immersion of the bulb. Soon after this
he suggested that the second point should he the boil-
ing point of water, but this was not adopted at the time.
Delance suggested that the freezing point of water should
be marked "cold" ( — 10 deg.) the melting point of butter
"hot" ( + 10 deg.) and the space midway between
"temperate" (0 deg.), with ten divisions between each.
In II I I Fahrenheit arranged a scale for thermometers
that showed the freezing of water at 32 deg. and the
boiling of water al 212 deg. Many suggestions have been
made as to why he graduated the freezing and boiling of
water into 180 divisions, one being that as he was an
astronomical-instrument maker and as his machines
divided to full circles (360 divisions), he used a half-circle
for his scale. Seventeen years later Reaumur, a French
physicist, broughl out a scale on which the freezing point
of water appeared as 0 deg., the distance between this
and the boiling point of water being divided into eighty
equal parts. Anders Celsius, professor of astronomy at
the University of Upsala, proposed a scale in 1742 and
called the freezing point of water 100 deg. and the
boiling point of water zero degrees.
These points were afterward reversed by Christin of
Lyons (France) in 1843, and the result is the well-known
Centigrade scale. Athanasius Kircher was the first to use
quicksilver in thermometers. Quicksilver and alcohol
have been accepted by the scientific world as convenient
and accurate means to indicate the temperature of any-
thing with which the tube containing them may come in
contact.
For high temperatures quicksilver is used, as it freezes
at about — 38 deg. F. ( — 39 deg. C.) and boils at 662 deg.
F. (— 1-357 cleg. C). As the freezing point of mercury is
fairly high, alcohol thermometers are invariably used in
very cold climates. This liquid freezes at — 203 deg. F.
(—131).:. deg. C.) and boils at 173.5 deg. F. (+78.5
deg. C).
From the foregoing it will be seen that quicksilver is
unsuitable for any very low temperature and alcohol is
unsuitable for any very high temperature.
Conversion of Thermometer Scales
To convert Centigrade degrees to Fahrenheit degrees,
multiply by 9, divide the product by 5 and add 32, if the
temperature is above 0 deg C. When the temperature is
below 0 deg. deduct 32 instead of adding.
In converting Fahrenheit degrees to Centigrade degrees
subtract 32, multiply by 5, and divide by 9, if the temper-
ature is above 0 deg. F. When the temperature is below
0 deg. F. add 32 instead of subtracting.
To convert Reaumur degrees to Fahrenheit degrees
multiply by 9, divide by 4 and add 32, if the temperature
is above 0 deg. R. When the temperature is below 0 deg.
deduct 32 instead of adding.
In converting Reaumur degrees to Centigrade degrees,
multiply by 5 and divide by 4.
To convert Centigrade degrees to Reaumur degrees,
multiply by 4 and divide by 5.
Centigrade, water freezes at 0 deg. and boils at 100 deg.
Fahrenheit, water freezes at 32 deg. and boils at 212
deg.
Reaumur, water freezes at 0 deg. and boils at 80 deg.
3$
t!nes of Tungsten — Tungsten is used principally as an
alloy of high-speed steel — that is, steel used in making
tools used in metal-turning' lathes running at high speed —
to which it imparts the property of holding temper at higher
temperature than carbon steels will, according to the U. SJ.
Geological Survey. The now well known ductile tungsten
is used for incandescent lamps, which are fast displacing
carbon lamps. This alloy is practically insoluble in all the
common acids, its melting point is higher than that of any
other metal, its tensile strength exceeds that of iron and
nickel, it is paramagnetic, it can be drawn to smaller sizes
than any other metal (0.0002 in. in diameter), and its spe-
cific gravity is 70 per cent, higher than that of lead.
576
p o w ]•; i:
Vol. 41, Xo. 17
of ilHn©
PFiimfiinig O
By Davis H. Tuck
©vermnnnieiniii
SYNOPSIS — Wherein our plant supplies light,
heat and power for the Government printing tiffin1
and for the new Washington post office. Tin- old
plant iras remodeled and Hie electrical circuit*
changed from a I iro-icire. 120-voli to a three-wire,
240-120-volt system. Test figures of the rede-
sigm d plant are given.
Due to the proximity of the new Washington, 1». C,
post office to the Government printing office it was deemed
advisable to obtain energy for heat, light and power
from the power plant of the printing office. The electrical
also decided to replace one of the small reciprocating gen-
crating units by a turbo-generator of sufficient capacity
to carry the load of both the printing office and the new
post office. By such a change a gain in efficiency could be
realized by the substitution of a more efficient prime
mover and by the utilization of one unit of relatively large
capacity in place of several small units.
The boilers in the plant were overtaxed during the win-
ter months by the requirements of the printing office and
were not adequate for the increased load imposed by the
new post office. Therefore, it was necessary to add to the
boiler equipment and. as the stack was not large enough
to produce the additional draft required by the additional
boilers, it was necessary
to build a suitable stack.
Fig. 1 is a plan and ele-
vation of the plant before
the changes were made.
The boiler equipment
consisted of eight 300-
hp. hand-fired Scotch-
marine boilers with aux-
imF
LONGITUDINAL SECTION A-B
energy required by the printing office had increased un-
til the distributing lines were likely to become overtaxed
with a subsequent increase of load. The generating equip-
ment had been added to from time to time until there
were four units in the plant. The power-receiving cir-
cuits of the new post office were designed for 210, and
the lighting system lor 120 volts. The power-receiving
circuits of the printing office were for 120 volts.
After an analysis of these conditions it was decided
to change the two-wire. 120-volt system, to a three-wire,
240-120-volt system to meet the requirements of the new
post office and at (he same time increase the capacity
of the distributing circuits of the printing office. It was
F10. 1. Plan and Elevatiox of the
Plant before the Change Was Made
diary apparatus including two feed-water
heaters. The generating equipment con-
sisted of two cross-compound Allis engines
directly connected to two ''00-kw. Crocker-
Wheeler direct-current generators, one sim-
ilar unit of 300-kw. capacity, and another
of 125-kw. capacity. Two air compressors of 1500 cu.ft.
of free air per minute capacity supply air at 50 lb. pres-
sure to various industrial processes in the printing office.
One pump of 2,000,000 gal. per 24 hr. capacity main-
tains a high-pressure system for industrial processes and
for fire protection in both buildings.
The original plans of the changes to be made include
the installing of four 500-hp. water-tube boilers with
superheaters, siokers. feed pumps and piping: an alterna-
tive plan called for putting in two boilers with auxilia-
ries, similar to those already in place, should the appro-
priation not permit of water-tube boilers.
The new feed-water heater was to have a capacity Eor
April 27, L91S
POWE It
577
heating Hie water for not less than 1600 hp. of boilers
to a temperature within 2 cleg, of thai of the exhausl
-train. All piping in that part of the boiler house which
was iii contain the new boilers, excepl the main steam
header, was to be removed, and all steam, exhaust, water
and waste piping necessary for the new equipment pul in.
Changes in the heating feed pipes in the printing office
and for the post office were also to be made, and coal- and
ash-handling machinery was to be put in for both the new
and the old boilers. The erection of a 200-ft. chimney
to be 10 ft. 6 in inside diameter at the top to serve the
new boiler was also contemplated.
The new turbine and three-wire generator were to
be of 1000-kw. rapacity. In the proposal for this unit
it was stated that in case the guarantees of the builders
US POST OFFICE
PIPE WALL ANCHOR
Fig. 2. Details of Tunnel Construction and Wall
Brackets
di tie red. they would be evaluated for the purpose of com-
parison as follows : The cost to generate steam to be
taken at 16c. per 1000 lb., the unit being assumed to oper-
ate 16 hr. per day, 365 days in the year, and the algebraic
sum of the savings at one-half, three-quarter, full and one
and one-half load, with load factors of 20, 50; 15 and 5 re-
spectively, would represent the gross savings per year ef-
fected by the units with the lower steam consumption over
the unit with higher.
The generator was to have a capacity for two hours of
150 per cent, of its normal load of 1000 kw. The maxi-
mum temperature rise of the generator, after being run
at full normal load continuously for 21 hr., was not
to exceed by more than 15 deg. ('. the temperature of the
surrounding air corrected to a standard room temperature
of 25 deg. C.j in accordance with the standards adopted
by tl e American Institute of Electrical Engineers.
Changing of the 300-kw., 120-volt generator to a three-
wire 120-240-volt generator and all necessary connections
and wiring to the switchboard were also included in the
original plans, also the changing of the switchboard and
instruments from the two-wire to a three-wire system.
The two 600-kw. generators were I > be connected in series
to form a three-wire system. There would then be in-
stalled one unit of 300-kw., one of 1000-kw. and one of
1200-kw. capacity. The switchboard was to consist of 16
panels and two sets of busbars, one for lighting and one
for power, with switches so arranged that either si
busbars could be um\ for cither lighting or power.
A tunnel from the printing office to the posi office
for thi ping for heating and for the electric wir-
ing was required, the construction of which was to con-
form with the plan and elevation in Fig. 2. A wall
bracket, anchor and roll supports such as used are also
shown. The tunnel is of course larger than necessary for
this particular purpose, but was made large enough to ac-
commodate a future mail-conveying equipment.
As the appropriation made by Congress for the addi-
tions to the power plant was not sufficient to earn' out
all of the improvements planned, it was decided to dis-
tribute the appropriation and purchase two 500-hp. water-
tube boilers, without superheaters, one feed-water heater.
all necessary piping, ash-handling machinery, chimney,
turbine and generator to carry out the changes on the 300-
kw. generator and switchboard and to construct the tun-
nel.
It was also decided to change the two 600-kw. 120-volt
rators to 240-volt generators and install balancer sets
for the new three-wire system instead of cross-connecting
them as originally intended. The new plant therefore
consists of one 300-kw. generator, two 600-kw. generators
and one 1000-kw. generator all arranged for the three-
wire system.
Referring to Fig. 1, the two 300-hp. Scotch marine
boilers at the right of the new chimney were replaced by
two 500-hp. Babcock & Wilcox, cross-drum, water-tube
boilers. The old stack, which was of steel construction
lined with firebrick, 6 ft. I in. inside diameter and 150
ft. high, was removed and the new 200-ft. brick stack
was constructed as indicated. The r.'5-kw. unit next to
the office was replaced by the 1000-kw. turbo-generator,
which upon acceptance tests conformed to the guarantees
of the makers. The results of the tests of the boilers and
turbo-generators are given in detail in the accompanying
report-.
On account of the amount of steam used for other
purposes, including steam heat, live steam for industrial
uses, for pumping water and for use in air compressors, a
test was made on the steam-generating engines and it was
found that they used about 20.5 lb. of water per kilowatt-
hour. Then the total coal consumed multiplied by 20.5
and divided by the total water evaporated gives the coal
consumed per kilowatt-hour. From this point the follow-
ing formula is used to determine the cost of energy per
kilowatt-hour.
Cost per l>r.-hr. =
— X {Be Ew) | Ec Be Sm-\
kw.-hr.
where
W = Total pounds of water evaporated;
iv = Water evaporated pei pound of coal;
Be = Boiler-room expense;
De = Dynamo expense;
c = Coal per kilowatt-hour;
Kir Engineer's wages*
Ee = Engine-room expense (engines and generators
only) ;
o = Office expense.
The load factor, defined as the ratio of the average load
5 ; 8
P 0 W E K
Vol. 41, No. 17
Test No. I — Heimikt hi Stea.uim; Test of Fuel
Results of boiler trial made by the U. S. Bureau of Mines at the Government printing office, Washingtc
termine the ability to make the guarantee at 150 per cent, rating.
Principal conditions governing trial: Draft kept about constant; coal wet in hopper.
Dimensions, Proportions, Etc.
Boiler, Babcock & Wiloox Cross Drum
Grnte surface, sq.ft 102
Water-heating Burface, sq.ft 5200
Date of trial Sept. 22-23, L91 I
Duration of trial, hr. (9:00 p.m. to 3:00 p.m.) 18 00
Method of ptarting and stopping test Mtemate
Kind of coal New River
Average Pressures, Temperatures Fahrenheit. Etc.
Steam pressure bv Ease, lb. per sq.in. 129.3
Force of draft between damper and boiler, in. of water 0 72
Force of draft in furnace, in. of water 0. 59
Temperature of air entering ashpit, deg 94
Temperature of feed water entering boiler, deg. 72
Temperature of escaping gases from boiler, deg 540
Quality of Steam
Per cent, of moisture in steam 0.0
Quality factor of steam (dry steam = unity) 1.000
Total Quantities
Weight of coal as fired, lb 47.595
Per cent, of moisture in coal 3.09
Total weight of drv coal consumed, lb 46,032
Total dry ash and refuse, lb 1,415
Total combustible consumed, lb. 41,017
Total combustible consumed, determined from analysis of coal and
refuse, lb tl.ttO
Ratio of drv asli and refuse to dry coal, per cent 9.6
Total weight of water fed to boiler, lb. 420. l.'is
Equivalent water fed to boiler from and at 212 deg . lh 50l'.,r,ns
Total water evaporated, corrected for quality of steam, lb 42(1, 43K
Factor of evaporation based on temperature of water entering boiler. . 1 18S
Total equivalent evaporation from and at 212 deg. F., lb 506,6(18
Hourly Quantities and Rates
Dry coal charged per hr., lb 2,557
Coal as fired, charged per hr., lb 2,639
Combustible consumed per hr., lb 2,312
Combustible consumed per hr., determined from an analysis of coal
and refuse, lb 2,302
Dry coal charged per sq.ft. of grate surface per hr, lh 25 07
Combustible consumed per sq.ft. of water heating surface per hr., lb. 0 445
Water evaporated per hr., corrected for quality of steam, lh 23,6ttl
Equivalent evaporation per hr., from and at 212 deg. F . lh 28,1 15
Equivalent evaporation per hr. from and at 212 deg. F. per sq.ft. of
water heating surface, lb 5.412
Moisture,
Volatile matter.
Fixed carbon . . .
Ash
Approximate Analysis of Coal, Test Sample
\, Fired,
Per Cent.
3 09
20 5fi
71.06
Laboratory
Moisture and
Ash Free
Per Cent.
Total
Sulphur (separately determined)
Moisture as fired, as per cent, ol
ash free coal, test sample
20 7
70.9
5.3
.29
Ultimate Analysis of Coal. Car Sample
Hydrogen.
CarboD . . .
Nitrogen .
Oxygen . . .
Sulphur.
Ash
Moisture and
Ash Free
Per Cent.
4 77
88.65
1.72
3 66
Total.
Analysis of Refuse, Moisture iter
Combustible
i::uti,\ mattei
( lalorific Value
Caloiifie value by oxygen calorimeter, per lh. of dry coal,
B.t.u.. ..
Calorific value by oxygen calorimeter, per lb. of com-
bustible, B.t.u
Calorific value by oxygen calorimeter per lb. of coal as
fired, B.t.u.,
*Used in computath
14,727*
14,722
15,584*
15,574
14,270*
14,267
other determinations made as check.
Capacity
Evaporation per hr. from and at 212 deg. F., lb
Hp. developed (34.5 lb. of water evaporated per hr. into dry steam
from and at 212 deg. F. equals one hp.) B.hp
Rated capacity per hr., from and at 212 deg. F., lb
Percentage of builders rated hp. developed, per cent
Economy Results
Water fed per lb. of coal as fired, lb
Water evaporated per lb. of dry coal, lb
Equivalent evaporation from and at 212 deg. F. per lb. of coal aa
fired, lb
Equivalent evaporation from and at 212 deg. F. per lb. of dry coal, lb.
Equivalent evaporation from and at 212 deg. F. per lb. of combustible,
lb..
Equivalent evaporation from and at 212 deg. F. per lb. of coal i
termined from analysis of coal and refuse
ide-
S15 8
17,940
156.9
12.17
12,23
Efficiency
Efficiency of boiler including grate, heat absorbed by boiler per lb. of
dry coal, divided by heat of one lb. of dry coal, per cent
Efficiency of boiler, heat absorbed by boiler per lb. of combustible,
divided by heat value of one lb. of combustible per cent.. . . .
Efficiency of boiler, heat absorbed by boiler per lb. of combustible, de-
termined from analysis of coal and refuse divided by heat value of
one lb. of combustible, per cent
Smoke Data
Perc -ntatre of smoke as observed, Ringelmann chart method per cent.
black
Methods of Firing
Average thickness of fire, in
Air per lb. of dry coal, lb
Air per lb. of combustible, lb
Analysis of Dry Gases by Volume
Carbon dioxide (C02), per cent
Oxygen (03> per cent
Carbon monoxide (CO), per cent
Nitrogen (Ns), Argon (A2), and inert gases, by difference, per cent.. .
Total
Heat Value or the Distribution of the Heating Valv
Heat absorbed by boiler
Loss due to evaporation in coal
Loss due to heat carried away by steam formed by
burning hydrogen 535
Loss due to heat carried away in dry flue gases 1,944
Loss due to carbon monoxide 73
Loss due to combustible in ash and refuse 731
Loss due to heating moisture in air
Loss due to unconsumed hydrogen and hydrocarbons,
to radiation and unaccounted for 391
le of the Combustible
Combustible Burned
B t.u. Per Cent.
11,868 76.1
3.4
12.5
0.5
4.7
Total calorific value of one lb. of combustible .
15.5S4
Test No. 2— Results of Boiler Trial at 50 per Cent, of Rating
MadP by U. S. Bureau of Mines at the Government printing office, Washington, D. C, to determine the ability to make
guarantee at 50 per cent, of rating.
Principal conditions governing trial: Coal wet in hopper throughout test; load steady.
1 Ml
Proportions, Etc.
Boiler, Babeock & Wilcox Cross Drum
Grato surface, sq.ft. chain grate 102
Water heating surface, sq.ft 5200
Date of triil Sept. 21-22, 1914
Duration of trial, hr. (0:02 a.m. to3:02 a.m > IS
Method of starting and stopping the test Alternate
Kii d of eoal New River
Size oi coal, run of mine Apparently
Average Pressures, Temperature Fahrenheit, Etc.
Steam pressure by cane, lb. per sq.in. 129 4
Force of dratt between damper and boiler, in. of water. 0.11
Temperature oc air entering ashpit, dec 98
Temperature oi feed water entering boiler, deg 71
Temperature of escaping gases from boiler, deg 360
Quality of Steam
Per cent, of .nt'Sture in steam
Quality facto ol steam (dry steam
Total Quantities
Weight of coal as fired, lb
Per cent, of moisture in coal
Total weight of dry coal consumed, lb
Total dry ash rind refuse, lb.
Total combustible consumed, lb
Total combustible consumed determined from analysis of coal and
refuse, lb
Ratio of dry ash and refuse to dry coal, per cent
Total weight of water fed to boiler, lb
Equivalent water fed to boiler from and at 212 deg. F., lb
Total water evaporated corrected for quality of steam, lb.
Factor of evaporation based on temperature of water entering boiler.
Total equivalent evaporation from and at 212 deg. F., lb
Hourly Quantities and Rates
Dry coal charged per hr., lb
Coal as fired, charged per hr., lb
Combustible consumed per hr ., lb.
Combustible consumed per hr., determined from an analysis of coal
and refuse, lb
Dry coal charged per sq.ft. grate surface per hour, lb
Combustible consumed per sq.ft. of heating surface per hr , lb
Water evaporated per hour, corrected for quality of steam, lb
22. son
2.71
22,272
2,545
19,727
19,771
11 4
215,172
255,840
214.742
1 ISO
2.Vvi2.s
1237
1272
1096
1096
12 13
o 211
11,930
April 27, 1915
POWEE
579
Test No. 2 — Continued
Approximate Analysis of Coal. Tefll Sample
Per Cent.
l
Per Cent.
Moisture and
Ash Free
Per Cent.
Moisture.
2.7*
21 5*
2 71
21 35
70.30
5.64
23 20
76.71
Ash
r, 6*
Total
Sulphur separately
Moisture as Bred,
ash free coal, tes
100 00
1 i
1.13
2.94
100 00
1.23
- p'*r cenl of moisture am
sample
Ultimate Analysis of Coal.
Car Sample
Moisture
1 r,->*
Pet Cent.
Moisture and
Ash Free
Per Cent.
4 4
M 6
1.6
2.4
1.2
5.8
4 71
89.80
1.74
2.52
1.23
100.00
ure Free
100.00
Analysis of Refuse, Mois
Per Cent.
47.9
52.1
loo.oo
Economy Results
Water fed per lb. of cnnl as fired, 11.
Water evaporated per lb. of dry coal, lb.
Equivalent evaporation from and at 212 deg i>- r lh. of coal as fired, lb.
Equivalent evaporation per lb. of dry coal, lb
Equivalent evaporation per lb. of combustible
Equivalent evaporation from and at 212 deg. F. per lb. of combustible
determined from an analysis of coal and refuse, lb
Efficiency
Efficiency of boiler, including grate heat absorbed by boiler per lb. of
dry coal, divided by heat value of one lb. of combustible
Efficiency of boiler, heat absorbed by boiler per lb. of combustible,
divided by heat value of one lb. of combustible
Efficiency of boiler, heat absorbed by boiler per lb of combustible, de-
termined from analysis of co 1 and refuse, divided by heat value of
one lb. of combustible
Smoke Data
Methods of Firing
Average thickness of fire, in
Appearance and action of coal on grate; burns well when wet,
Description of flame, difficulties in handling fire, refuse, clinker, and
general remarks Short yellowish flame; refuse high in carbon.
Air per lb. of dry coa.
Air per lb. of combustible
Analysis of Dry Ga3cs by Volume
9.40
9.64
II 15
11 46
12 4!t
12.91
Carbon dioxide (COa)
Oxygen (02)
Hydrogen, and hydrocarbons
Nitrogen (N3), Argon (Aa), and inert gases (by difference) .
0.0
5.5
r Cent,
14.3
4.6
0.1
81.0
Calorific Value
Calorific value bv oxvgen calorimeter, per lb. of drv coal,
B.t.u 14,666* 14,706
Calorific value by oxygen calorimeter, per lb. of com-
bustible. B.t.u 15,569* 15,611
Calorific value bv oxvgen calorimeter, per lb. of coal as
fired, B.t.u...." 14,270* 14,308
Capacity
Evaporation per hr. from and at 212 deg. F , lb. 14,185
Hp. developed (34.5 lb. of water evaporated per hr. into dry steam
from and at 212 deg. F. equals one boiler hp.) 41 1 2
Rated capacity per hr., from and at 212 deg. F., lb 17,940
Builder's rated boiler hp 520
Percentage of builders' rated hp. developed, per cent 79 . 1
Total
Heat Balance <
100.00
i of the Heating Value of the Combustible
Combustible Burned
Heat absorbed by boiler
Loss due to evaporation of moisture in coal
Loss due to heat carried away by steam formed by
burning hydrogen
Loss due to heat carried away in dry flue gas
Loss due to carbon monoxide
Loss due to combustible in ash and refuse
Loss due to heating moisture in air
Loss due to unconsumed hydrogen and hydrocarbons,
to radiation, and unaccounted for
Total calorific value of one lb. of combustible
Shop and Acceptance Tests of Tuubine
Test Number
19
Date
Time, f r >m
Time, to 5:30 p,
Per cent, of normal full load
Throttle pressure, lb. per sq.in., gage..
Inlet pressure, lb. per sq.in., gage
Vacuum in l.p. outlet by mercury
column
Vacuum referred to 30-in. barometer. .
Barometer
Temperature at throttle inlet, deg. F.
3-5-14
3-5-M
3-6-14
4:30
7:30
3:05
;o p.m.
8:30 p.m.
4:05 a.n
50
100
150
149.5
150.3
151.5
65 2
125.8
137.4
26 64
26 3
25.5
27 53
27 22
26.46
29 li
29.08
29.04
374.5
375 . 7
375.5
Speed shown by continuous counter in-
dicator, r.p.m
Load in kilowatts
Total net lb. of steam condensed per hr.
Lb. of steam per kw.-hr
Superheat at throttle, deg. F
Acceptance Test
Vacuum, full load, in. of mercury
Vacuum, 150 per cent, of full load, in. of mercury
Temperature of injection water, deg. F
Temperature of discharge water full load, deg. F. .
With 125 per cent, full load, deg. F
Injection water used, lb. per hour
Steam pressure, lb. per sq.in
3642
3609
3583
500
1000
1500
10,862
19,161
31,329
21.72
19.16
20.9
9
9.8
9
POWEB PlaXT-
-Statf.mekt of Operating Expexses
October, 1914
Operation :
Boiler-room labor
Engine-room labor
Dynamo-room labor
Fuel
Water
Engine oil
Cylinder oil
Waste
Boiler-room supplies. .
Engine-room supplies. . . .
Dynamo-room supplies
Office force and supplies
Ash handling
Total
1519.67
577.83
445.50
1,530.03
Cost per
Ki,.l..
0 164c.
0.182
0.140
II Is.'
51
IV
2
73
79
24
13
27
101
ill
19
78
"016
0.001
0.025
0.004
Excl. of coal
Excl. of waste
and oil
Operation:
Boiler-room labor
Engine-room labor ...
Dvnamo-room labor
Fuel
Water
Engine oil
Cylinder oil
Waste
Boiler-room supplies
Engine-room su]i|, Mr .
Dynamo-room supplies .
Office force and supplies..
Ash handling
Total $3,340.88
Maintenance and 1 1
Buildings and fixtures $22.98
Boilers 53.62
Economizers
Pumps 4.76
Auxiliaries, boiler room 14.66
Piping 28.76
Engines 1.00
Generators
Condensers
Switchboard and meters
Auxiliaries, engine-room 4 . 08
0 002
0 005
0 009
Total
$129 .86
1 093c
Total
$601.29
618.34
II',.-, N.-,
I.XS'1 93
35.28
1 53
16 91
21.22
1.30
Ml 11
17.37
Total $3,749.43
Maintenance and Repairs:
Buildings and fixture.. $21.62
Boilers 16.84
Economizers
Pumps 7.76
Auxiliaries, boiler room 33 74
Piping 26 12
Engines 14 70
Generators
Condensers
Switchboard and meters
Auxiliaries, engine-room
Cost per
Kw.-hr.
0 152c.
0 156
II 118
0 477
Kxel. of ?oal
Excl. of waste
and oil
0.002
0 009
T 006
0 004
Total.
i •>;
0.030c.
Total— power plant $3,470 54
Total output, kw -hr., printing office 280,316. 1
Total output, kw.-hr., post office. 36,792.9
Total kw.-hr., including both 317,109 0
"Total coal consumed (854 tons 2S9 lb.) 1,913,249.0 lb.
Total lb. water evaporated 15,846,713.0 lb.
Average lb. water per lh. coal 8.28 lb.
Coal consumed for electrical purposes (350 tons 432 lb) 784,432.001b.
*For all purposes.
Total— power plant $3,872.08 0.975c.
Total output, kw.-hr., printing plant
Total output, kw.-hr., post office
Total output, kw.-hr, both
*Total coal consumed (tons 1220+2225 lb) 2
Total lb. water evaporated 22
Average lb. water evaporated per lb. coal
Coal consumed for electrical purposes (tons 4394-1249 lb.).. .
♦For all purposes.
332 521 . 2
6. .400. 5
39.' ,92 1.7
735,025.0 lb.
288 332 o
S 13
984,609 lb.
580
p o w e n
Vol. 41, No. i;
lor the twenty-lour hours to the maximum load for that
time, is about 71.7 per cent.
The cost per kilowatt-hour for electrical energy is low
as compared with the figures prevalent for plants of this
size. It will be noted, however, that there are no over-
head charges such as interest, depreciation and insurance.
The Government carries no insurance, and because of the
method of securing money for new apparatus by appro-
priation from Congress it is not necessary to make in-
terest and depreciation charges.
The plant is now operating under the new conditions
and all changes were made without any interruption to
the service.
The work enumerated herein was designed by and the
equipment installed under the direction of W. P. Metz,
M. E., Superintendent of Buildings.
The old equipment was removed and the new equip-
ment installed by the W. G. Cornell Co., acting as gen-
eral contractors.
Ds^edl^e PtLanrapi Maladies Asfees
By 0. D. flAVAnn
'The Giant Portland Cement Company, Egypt, Penn..
has developed a method of handling its boiler-room ashes
which is believed to be new. It is an application of the
centrifugal dredging pump which confines its use to
Pulley
4 Discharge Line
ball Bearing /*> Waife *"'*
Eikvation of Apparatus fob Handling Ashes
plants having plenty of cheap water and those which
waste the ashes within a few hundred feet of the build-
ing. The apparatus described was adopted, not because
it was believed to be in all respects the best for the
purpose, but because it was at hand.
The plant consists of four 250-hp. and one 400-hp.
water-tube boilers, hand-fired with anthracite barley coal.
The grates are stationary and the ashes are drawn through
the front doors. In front of the boilers and just under
the floor is a 12-in. spiral conveyor; a small opening un-
der each boiler d : is provided for the ashes to enter.
During cleaning, a stream of water is turned into the
conveyor at it- head, which serves to quench the heat
and assist the conveyor by partially floating the ashes.
The ashes are discharged into a crusher which reduces
the clinkers to pieces of about two inches diameter. This
crusher is home-made and consists of a cast-iron cyl-
inder 8 14 in. in diameter by 12 in. long, with 1-in. spikes
driven into tight-fitting holes and projecting 2 in. These
rows straddle stationary spikes 2 in. apart. The cyl-
inder is driven by a gear from the conveyor shaft. Prom
the crusher the ashes drop into the well where a 4-in.
horizontal-type dredging pump is mounted on the side
wall, the weight of the shaft and runner being carried
by a hall hearing at the floor level. The suction pipe
is bent to come in the center of the well and terminates
about a foot above the bottom. A 1-in. water pipe is
led down and turned up, with a 21-r,n- nozzle directly
under the suction and 6 in. away. The pump gland is
water-sealed by a Vk~in- pipe tapped in above the 4-in.
control valve. The water pressure at the valve is about
25 lb. The discharge, consisting of a 4-in. pipe, is led
up and out to the waste bank. A thimble of 5-in. pipe
is put over the suction and connected by a chain to the
lever at the floor.
The process of operation is as follows : Drop the thim-
ble before turning the ashes into the well to keep from
obstructing the water pipe; run in all the ashes the well
will hold. When ready to pump out, open the 4-in.
valve four turns and open the gland water valve. Allow
water to rise over the pump runner before starting. When
the pump has run a short time on water only to insure
the discharge pipe being clean, raise the thimble and al-
low the ashes to mix with the water. As high as fifteen
cleanings have been put into the well before pumping
out and have then been ejected in 30 min. The speed
of the pump is 658 r.p.m. The variation of speed with
head, as given by the manufacturer, is:
Head in Feet Speed, Rp.m. Head in Feet
30
Speed, Rp.m.
230
364
574
630
680
90
100
Speed, R.p.m.
727
812
890
960
1000
10S5
1145
Four horsepower is required for each ten-foot elevation.
v
The Colorado River Basin — A recent publication by the
United States Geological Survey contains much information of
value to all water users. All people interested in the water
flowing in the streams of the great Colorado River basin
should become familiar with the reports on the subject pub-
lished by the United States Geological Survey. Such reports,
covering the entire country, appear each year in twelve parts.
as water-supply papers. Part 9 of this series is devoted ex-
clusively to the Colorado River basin. This paper gives the
results of measurements of flow made at about 140 regular
river observation stations in the states of Colorado. Wyoming,
Utah, New Mexico, and Arizona, and at about 60 miscellaneous
points in those states. This information is necessary for the
proper and economical installation and operation of water-
power plants, irrigation projects, systems of municipal water-
supply, works for the prevention of damage caused by devas-
tating floods — in fact, all works that involve the use or
control of water.
April %1, 1915 POW B R 581
mm iiiiiinuii urn niiim i iiiiiiitiiui mil i iiiuiiiiiuT'. mi nun iiiiiniimi iiiinimimi iiiiiiiiimiiiiiiiiiiiiniiiiiuiiniliililliliiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiillllllliiliuimj
xdlMoricmlb
i i . 1111111111111'
G£&©©sliE&g| as. Fjpof©§si©im
A correspondent recently asked us if we would advise
him to continue studying electricity when he prefers
steam engineering. We replied to this, as we would to
any similiar question, that on general principles it is
wise to study the subject which must appeals to one,
and that anyone is most, apt to succeed at the calling
he likes best. It is better to be a successful steam engi-
neer than a failure at anything else, no matter how much
more attractive the other position might seem to be.
The young man's doubt arose from his feeling' that
steam was getting out of date. This, of course, is ridicu-
lous, for the present at least. There is no denying' that
water power is gaining in use, and fortunately so, for the
coal supply is certainly diminishing, but there will be
plenty of fields for good steam operating engineers until
long after this generation has finished thinking about it.
There is a lot of truth in the verse foreword in this issue.
GuaMii^'avll.!in\g> aiia lEirngpiimeeTriiifiige
lolofcfoy
The temptation to scatter one's energies over too great
an area is particularly strong in engineering. The vari-
ous branches of the profession are so inclusive, and the
limitations of the individual are so marked, that the de-
sire to make use of every possible opportunity to broaden
one's knowledge of applied science often carries a man
off his feet, so to speak, and results in a good deal of in-
tellectual lost motion. Experienced men know how to
guard against the dissipation of their resources, and one
of the best methods is the cultivation of a hobby within
the field of one's work.
By this is meant settling one's thoughts largely upon
one special line of practice for a stated period, such as
the rest id' the winter and the early spring, and concen-
trating all one's extra efforts in the endeavor to acquire
a real mastery of the selected subject. Thus, one man
will decide to make a study of mechanical stokers, getting
every catalog and reading every printed thing he can lay
bands upon in this connection during the next two months
or so, talking with men who operate, buy, sell and repair
stokers, besieging the local public library for books con-
taining matter on this theme, and absorbing data and in-
formation with might and main at every opportunity.
Another man may prefer to take up the study of coal,
following so far as he may the latest advances in its labora-
tory testing by the government, getting the new points
of view regarding the volatile products of combustion, and
perhaps reading about the methods of mining and pre-
paring fuel for market. The next man may prefer to start
a system of interchanging and comparing operating data
among engineers of his acquaintance; another may want
to master standard wiring methods or study the limita-
tions of the gas engine and the producer.
All such work has real value. It should not blind a
man to what is going on in the field as a whole, hut giving
direction to his special interests, it enables progress in
mental acquisition to lie cumulative and thus tends to
lead one further into the mastery of a special subject
than is possible by mere desultory reach ig and observa-
tion.
One engineer began a collection of station-operating
costs in this way, and became so interested in the sub-
ject that he filled many pages of a notebook with com-
parative figures of the same and of different plants for
three or four years. Much of the data were obtained from
returns on file with the Public Service Commission of h s
state, and ultimately he was able to sell some of the ma-
terial to outside interests who heard that he was assem-
bling these costs, figured upon both unit and total bases.
The material sold was all public property, being reported
to the state annually, although few people knew of its ex-
istence, and in its study the engii eer observed many
interesting tendencies of practice, not ng particularly the
effect of larger generating units upon t.ie cost of labor per
kilowatt-hour, the influence of the day-load upon statio i
efficiency, and other valuable data.
The best thing about thus cultivating what might be
called a transient specialty is the enduring grasp of the
subject which, if once acquired, never entirely leaves one
high and dry in dealing with it later, but broadens the
interest of the busy engineer in many inter-related
branches of his profession.
Ssiff© Pipimvg?
We have laws or ordinances regulating the use of
boilers, the installation of electric wiring, plumbing and
for safe building construction, yet for some unknown rea-
son nothing in this direction has been accomplished with
regard to the safety of steam piping. There is not even
a rule making imperative the use of nonreturn valves at
the boiler, and at both boiler and header when more than
one boiler is used on pressure, possibly bee* ise these
valves cost more than the ordinary globe or gate valves.
The deciding consideration of all work seems to be the
price; the safety of jjlant and humanity are usually sec-
ondary considerations.
Engineers seem to be averse to specifying exactly whose
apparatus they require; such and such a make "or equal"
is the usual way of putting it, possibly to avoid misinter-
pretation as to motive. However, more than one manu-
facturer's material is good, and why not mention more
than one name, being particular in each case to specify
each maker's classification ? The pecuniary motive will
at least be absent, the specification will be clearer to all
interested, and such a practice will go far toward discour-
aging the sale of competing material now on the market,
which is invariably sold as the "equal." It is also well
to remember that ability of this "equal" material to fulfill
its name is often left to the judgment of others, who may
not be as conscientious as the engineers. The usual clause
relating to a guarantee for defective material and work-
582
POWEB
Vol. 41, No. IT
manship is akin to locking the stable after the horse
is gone. What good can the guarantee and actual re-
placing of defective material do to those physically in-
jured ?
It should be the aim of engineers to secure laws looking
to the safety of piping -work — in fact, the safety of all
engineering work. Particularly where pecuniary interest
can work against the safety of human life, the use of
safety devices must be imperative. Rules as to layout and
material, based upon past experience, must be enforced.
This will also give the engineer a freer hand in designim:
for the penurious owner, whose sole aim is to get out as
cheaply as possible.
&
Msil&iEajg* life® Mosft ©if IEfficieiacy
In the report of the Committee on Prime Movers, pre-
sented at the Philadelphia convention of the Xationa!
Electric Light Association, the point was made that a feel-
ing exists among power-ptlant owners that the use of so-
called "efficiency instruments" has been in a measure
instructive, but that on the whole the results have been
disappointing. The apparent reason set forth is that it
fl as supposed that an operator with such an instrument
before him would mterpret the record and apply the ob-
vious remedy for any poor results, whereas in reality, the
plant does not realize from automatic station records the
benefits which these might be made to yield. This is an
important matter for consideration, in fairness to the busy
operating engineer and in justice to his employer.
It is possible to load down a plant with automatic in-
struments whoso records and indications give very little
help to those in charge of the installation, but many plants
suffer from the lack of instruments in important locations
where moment to-moment records would be of immediate
help in operation. Without desiring to condemn any par-
ticular apparatus, unless equipment of this sort makes ex-
tremely direct measurements of a simple kind, its imme-
diate usefulness to the operator is problematical except
where such records have been interpreted by exhaustive
comparisons with other periods, and this is a species of
research work for which many engineers have no time.
The interpretation of highly analytical records, in con-
nection with some of the larger power stations, is there-
fore assigned to specially designated efficiency engineers
having a technical knowledge of thermodynamics and
chemistry, who are not burdened with routine operating
duties and who report direct to the chief engineer all con-
clusions and recommendations, based upon a continuous
analysis and study of the significant records of plant per-
formance and personal knowledge of station apparatus and
operating conditions. The distinction between operation
and the analysis of plant data is a real one, and in com-
panies where the output is large enough to warrant the
expense, such a division of labor may be very useful.
In most plants, however, the control of production
economy must rest in the hands of those who run the sta-
tion from shift to shift, supplemented by occasional or,
preferably, regular studies of performance by the engi-
neering staff Day after day, as the load varies, it is im-
portant to keep various pressures and temperatures, vol-
umes and weights close to predetermined figures. For
such work reliance upon steam gages, steam meters, coal
scales, watt-hour meters, draft gages, and, almost above
all else, upon thermometers located at strategic points.
must take the place of so called continuous graphic test
records whose significance cannot be taken without con-
sidering their relation to other and complex phenomena.
To take the case of the carbon-dioxide recorder, for ex-
ample, it should be clear that unless such data as this
apparatus gives apply to the plant as a whole and not to
a single boiler uptake, little immediate use can be made
of the observations yielded.
In a nutshell, it is better to determine by tests what
temperature-, pressures and volumes spell maximum plant
efficiency for a given load and operating conditions and to
try to approximate those readings, than to attempt to
rapidly interpret highly complex indications drawn from
portions of the station only, without having time to weigh
and balance a wide range of such data. That is, efforts
should be concentrated upon maintaining instrument read-
ings known to be favorable to economy of operation, leav-
ing the comparison of complex indications for the time
when analyses can be studied at will.
There is room for establishing in many plants certain
limits of operating efficiency expressed in maximum and
minimum instrument readings, to stay between which
should be the main object of the engineer's routine work.
Prompt adjustment of fuel supply, water supply and air
is more necessary in meeting the momentary conditions
of service than drawing academic parallels between the
percentage of ash in the pit of boiler Xo. 6 today and
the same date of last year. For efficient handling of a
plant one must have, first, a staff responsive to changes in
its service conditions and competent to recognize the lim-
its of efficient manipulation of individual apparatus, and
second, the ability within the reach of the plant to draw
from station history conclusions of value in meeting the
demands of daily routine and emergency service.
m
Popularity among his fellows is a Dig asset to an engi-
neer, but unless he has a commensurate amount of pro-
fessional competency behind it, he's some day going to be
a disappointment to himself and his friends.
:>:
The report of the commission which began about three
years ago to investigate the use of electricity in the
Netherlands states that the managements of a number of
industrial concerns are of the opinion that it is most
advantageous to furnish their own power. Many an
American manufacturer found that out long ago.
On January 16, 1909, President Roosevelt sent to Con-
gress a special message which seized the occasion of his
veto of an apparently innocent bill granting water-power
rights in Missouri to proclaim the discovery of a brand
new trust — the Water-Power Trust — and to denounce ii
as a menace to the people which in a short time would Lie
worse than even the Standard Oil Company.
"The movement is still in its infancy," declared the Presi-
dent, "and unless it is controlled, the history of the oil
industry will be repeated in the hydro-electric-power industry
with results far more oppressive and disastrous for the people."
Subsequent developments have shown that it was no
mare's-nest that the President unearthed. The "new
trust" has proven itself powerful enough to hold up
any legislation insuring the perpetuation of the people's
rights in the water power of the country.
April 27, 1915 P 0 W E R 583
annum i mi mi minim mini iiiiiiiiiiiiiin i iniiiiiniii iiiiiiiiiiiin i i mm nm m iiiiiiiiiiiiiiini inn inn i i m inn
CoirrespoinidleinicD
i
The top and middle bearings of our 2000-kw. Curtis
vertical turbine formerly received lubricating oil fed by
gravity from an overhead tank. We were dissatisfied with
this method of feeding and decided to take oil from the
valve-oil line and run it through a reducing valve to the
To Tof^*.
ia~H330
Kj
-6-.
Oil to Valves. 100 lb
Reducing Valve
Piping fob Oiling System of Vertical Cdetis
Tdebine
bearings. The hydraulically operated valves receive oil
at 100-lb. pressure; the bearing-oil pressure is now main-
tained at 18 lb.
The changes made in the piping are shown in the
sketch. The amount of lubricant fed to the bearing is
controlled by manipulating sight-feed valves. We are
well pleased with the change.
William Johnson.
Newton Square, Penn.
:*:
QsiS=Eiragami© C<o><a>IlIjm§| Wsiftea*
The article on "Gas-Engine Cooling Water," by G. A.
Field, in the Mar. 30 issue, contains some statements
which do not seem to be in accord with good practice.
Discussing thermo-siphon cooling systems in small
engines, he states that the bottom of the water tank
should not be below the level of the water outlet of the
cylinder jacket. He evidently means the jacket inlet
opening, but even in this case the statement is not
correct. It is usual in small engines to place the water
tank so that the bottom is on a level with the engine
base, with the tank outlet opening some three or four
inches from the bottom, this being connected to the en-
gine by the necessary pipes and elbows. It is safe to
say that 90 per cent, of tank-cooled engines are arranged
in this way and are giving perfect satisfaction.
In constructing an overhead tank special emphasis
should be placed on the fact that, if the tank is placed
at too great a height, there is danger of cracking the
cylinder jacket. Many engines do not have a thick jacket
wall and. stressed as it is by expansion, the jacket does
not require many pounds of water pressure to fracture it.
T recall one installation where the cooling tank was
placed on the roof of a three-story building, and the
jacket fractured the first day the engine ran. When a
new cylinder was received it also developed a crack after
a i'rw hours' run. It was decided that the hydrostatic
head due to the height of the tank caused the trouble.
This was partially demonstrated when the tank was
placed at the rear of the engine room, and no further
trouble was experienced.
L. H. MoKKIfON.
Fremont, Neb.
'&.
ClhsiimgBinig Speed ©f TlhiP©©°
IPIhsise BiradluactLnoBa Mtottos3
A two-speed, three-phase, 50- to 125-hp. induction mo-
tor, used to drive a rotary pump for pumping salt water
into the fire mains for fire protection and for flushing pur-
poses, was found to be too slow on the low speed to be of
any use for flushing, as it gave only 30 lb. pressure en Lhe
mains and would not raise the water to the highesi point
in the Hushing system. Therefore, the pump had to be
run at the high speed all the time, using nearly 1)0 kw.
and leaving the low-speed winding useless.
For the two different speeds, the motor has two wind-
ings on the stator, which are entirely independent of each
other. The high-speed winding has 6 poles, with the
coils connected on the inner end of the motor, and the low-
speed winding had 10 poles, with the coils connected
on the outer end. There are 90 sluts in the stator, making
Arrows show
location of dead coils
Fig.
1. Original Con-
nections
Pig. ■'.. Ch ustged Con-
nections
it suitable for both a 6-pole and a LO-pole, three-phase
winding, but not for an 8-pole winding, if all the mil-
were to be used.
After careful consideration it was decided to change
the low-speed winding from 10 poles to 8, leaving IS of the
coils idle. A change was also made from delta to star
connection and from series to parallel to increase the
conductivity for the greater current necessary.
Fig. 1 shows the connections as they were for 10 poles,
and Fig. 2 for 8 poles. The actual work of making the
change was simple and cost only a few dollars, being paid
for by the saving effected in less than a week's time.
58 f
P 0"W E B
Vol. 41, Xo. 17
The motor, when tested out at no load and at full load.
was found to run just as well as when connected as a 10-
pole motor with all the coils in use. It has been running
almost constantly lor over two wars on the low-speed as
• pole motor, giving 45 lb. pressure on the mains.
which is all that is needed, and using only 40 kw., thus
making a saving of over 1400 kw.-hr. per day.
W. If. Baxkhead.
Bremerton. Wash.
CosHrosii©^ ©if Hip©^ sunidl §&©©H
The conclusion of < '. 0. Standstrom in the issue of
Mar. 23, page 116, that there is no vital difference be-
tween wrought iron and the steel used in its place will
doubtless I e concurred in by many who have attempted
to distinguish between these two materials by ordinary
tests. The reason is that the recent advances in the art
of steel making have produced a steel which has nearly
all the ordinary characteristics of wrought iron. It i-
tough, soft and stronger than wrought iron and does not
harden when quenched from a red heat.
Of its man >• uses, the one of most importance to the en-
gineer is Ln tidies and pipes. When welded pipe was firsl
made, wrought iron al me was available, and for several
years after the advent of steel its use was not even con-
sidered for welded pipe, but recently a pipe steel has been
developed. Following are the comparative chemical
analyses and physical tests of steel and wrought pipe as
i -ported in the 1913 "Proceedings of the American Gas
Institute:"
Steel Pipe, Wrought-Iron Pipe,
Chemical Analysis — per Cent. per Cent.
Si. icon 0.01
Sulphur 0.05 0.03
Phosphorus 0.10 0.17
Manganese 0.30 trace
Carbon 0.07 trace, irregular
Oxides (slag) 0.10 1.20 to 2.00
Physical Prorsrties —
Tensile strength.... 5S.000 lb. per sq.in. 46,000 lb. per sq .in.
Elastic limit 34,000 lb. per sq.in. 2S, 000 lb. per sq.in.
Elongation 22 per cent, in 8 in. 12 per cent, in S in.
Reduction in area... 55 per cent. 25 per cent.
It will be noted that wrought iron contains considerable
cinder, or slag, a peculiarity of wrought iron as made by
the old puddling process. This slag can frequently he
ol served in a cross-section of iron pipe, especially with the
aid of a magnifying glass. The tensile strength of the
iron was measured when the sample was pulled long -
tudinally. and would he considerably less if pulled trans-
versely to the direction of rolling, while the steel is prac-
tically of the same strength in all directions. A wrought-
iron pipe, therefore, will fail under a lower bursting pres-
sure than one of steel. At first, considerable difficulty
was experienced in threading steel pipe, and dies which
would cut a fairly good thread on wrought pipe would
make a ragged thread and work hard on steel, but cor-
rectly designed dies with more rake and relief have been
made.
As to their relative durability and resistance to cor-
rosion there is much contradictory evidence, and it is
difficult to from prejudice. One of the
most generally accepted theories is that corrosion i-
to electrolytic action, and such conditions seem to affect
both iron and steel alike. It is true that structures made
from puddled wrought iron have remained in good condi-
tion after exposun o he elements for more than a cen-
tury. On the other hand, under certain conditions, iron
and steel pipes installed together have been destroyed 1 >\
corrosion within a few months, both being about equally
affected.
With its passing it seems likely that wrought iron is
esteemed more on ai count of its pas! reputation than be-
cause of am distinct superiority over the modern product.
It is also quite probable that much of the so-called
wrought iron supplied to the trade at the present time is
in reality steel, and the satisfaction it gives depends upon
its quality and whether it is adapted to the purpose for
which it is used.
William A. Di wkli-y.
Atlantic City, X. J.
C. < ). Sandstrom states that there are no reliable data
regarding the relative ability of iron and steel pipe to re-
-1-1 corrosion. The following is taken from the National
Birth tin ■
Prof. T. N. Thompson in March, 1906, installed alternate
pipes of the two metals in a hot-water line, and at the end
of a year discovered that steel pipe had approximately 7]_-
per cent, longer life than wrought iron under such conditions.
In a similar test carried out by a committee appointed by the
American Society of Heating and Ventilating Engineers with
iron and steel pipe made by various companies, Professor
Thompson reported: "We believe this test demonstrates that
modern steel pipe of good quality is at least as durable as
modern strictly wrought iron and is very much superior to a
poor quality wrought iron in this class of work." (A. S. H.
and V. Engineers, 1909.)
Teste carried on by the Pittsburgh Coal Co., H. C.
Prick Coal Co. and others indicate that steel is at least
equal to wrought iron, in resisting corrosion (Iron Age,
July 13. 1906).
In his textbook. "The Metallurgy of Iron and Steel,"
Stoughton, one of those who carried out exhaustive
investigations, says: "The evidence goes to show that
properly made steel corrodes no more than wrought iron."'
J. Xewton Fried, in his recent book, "The Corrosion
of Iron and Steel." states that "it would appear, there-
fore, that when everything is taken into consideration
there is practically nothing to choose between wrought
iron and steel as at present manufactured" (page 286),
and finally concludes with these word- : "These and many
other instances might be cited as illustrating the fact
that good steel corrodes at much the same rate as good
wrought iron" (page 288).
A. Sang, in a thorough resume of the question, entitled
"The Corrosion of Iron and Steel." says that "properly
protected steel and iron rust to about the same extent, the
steel doing so more uniformly."' and adds, "The best qual-
ity of charcoal iron is practically as resistant as the best
quality of steel used for similar purposes" (page 4!)).
and in regard to pipe, says : "The carefully acquired ex-
perience of the largest manufacturers of tubes in the
world, which induced them recently to abandon the manu-
facture ' t-iron pipe, teaches that the use of steel
in place of iron, at least in the United States, for the
special purpose of tubing is to lie preferred; the tendency
of steel to pit is somewhat less than that of iron and it
welds at the joint fully as well'" (page Ml.
Prof. Ira H. Woolson {Engineering News, Dec. 8,
1910) secured 89 samples of corroded pipe from sevei
bath houses in New York City. Of these samples 17
proved to be wrought iron and the remainder steel. He
concluded: "In my judgment, from the evidence col-
lected there was absolutely no difference in the corrosion
April 87, 191!
PO w E i;
585
of tin' two classes of pipe; they appear to he equally sus-
ceptible to the attack."
Dr. W. II. Walker (New England Water-Works As-
sociation, March, 1912), of the Massachusetts Institute <>i
Technology, secured n' I samples of wrought-iron and steel
pipe in adjacent service. These had been in use from 2
to l ; years. He reported thai of the 64 samples 20 favor
steel, IS iron, S shew iiii 1 1 i ll'ereiiee ill corrosion anil 17
mi corrosion at all. These results again demonstrate that,
taken mi the average, there is no difference in the corro-
sion of iron and steel pipe. Conversations held with en-
gineers in charge id' plants during this investigation con-
firm the statement alreadj made that a pipe is fre-
quently called steel when corrosion is found to he exces-
sive, while it is set down as iron if it. rusts hut Little.
P. DeC. Ball (Cold Storage and Ice Trade Journal),
in a paper read before the American Society of Refrigerat-
ing Engineers, made the following statements:
From 33 years of personal experience and observation con-
structing, erecting and operating ice-making ami refriger-
ating machines, absorption and compression types, and using
iron pipes for the first 14 years, and iron and steel pipes for
the next 19 years, we are convinced that local conditions only
govern the corrosion of pipes in refrigerating and ice-making
machines, and that, chemically and mechanically, mild-steel
pipe meets the requirements of the refrigerating engineers in
all respects, and better than any other pipe for the reason
that it is superior in point of finish, strength, strength of
seam and uniformity of material.
James E. Noble.
Toronto, Out., Canada.
IBms'imedUOiatb Sftanpftes*
On account of the liability of an operator to try to
start a motor with the field switch open, it is not customary
to install switches in the field circuits of motors. Where
standard starting boxes are used, proper connections to
Showing Wrong Field Connection
the box insure that the line voltage will not be applied
to the armature with the held nnexeited, unless through
some fault an open circuit exists. Where a starting box
that does not handle the field current is used, it is safe
to connect the held circuit across the service side of tin'
line switch so that closing this switch will energize the
held before the voltage can be applied to the armature,
through the starting box.
Opening of the line switch then opens the field circuit.
hill also opens the armature circuit. Irrespective of the
details of the field connection, however, if the motor fails
to start when the starting handle is thrown, and flashing
Of the starter indicates the armature to be taking current,
a piece of magnetic metal should be held to the polepieees
t" see if they are energized.
A manufacturer replaced a motor with a larger one
which had been bought second-hand. Both motors had
three leads. The shop had been rewired with larger wire
for the new motor and the operator thought he had con-
nected the second machine the same as the first. It de-
veloped, however, that he had connected the free field
wire, as indicated by the dotted line. BO that both ends of
the held were connected to the same side of the circuit.
The result was a burned starting box before be found out
the trouble.
J. A. HoRTON.
Schenectady, N. Y.
The article in the Mar. 30 issue of Power on "Effi-
ciency Engineers" sounds good. Why not get up a.
National Society of Efficiency Engineers based upon
"deeds performed" as a degree of eligibility. Let appli-
cants state the efficiency they are able to produce, as
well as twelve sales or installations of merit on each
account they may handle. There is a crying need for
factory efficiency, particularly in this Southland, where
negro labor is so prevalent. Thousands of plant mana-
gers are innocently losing a lot of money every twelve
months, because they have never been "put wise" to a
better way to run their plant.
J. S. HOFFECKER.
Richmond, Va.
§fts°<Bia^a©sntly dirndl FEywlfo©©]!
Referring to your editorial on '-Effect of High Steam
Pressure on Flywheel Risks," there is another phase of
the current effort to get the greatest amount of energy
out of a dollar's worth of engine which you might have
mentioned. The amount of energy produced per vnil
of time depends upon the piston speed as well as upon
the mean effective pressure, and the raising of the piston
-pee, I from the GOO ft. per min. usual 25 years ago to
the 900 or more now not uncommon makes possible
an increase in energy produced per second of 50 per
cent, or more from this cause alone: and this energy,
in addition to that due, as your editorial pointed out.
to the increased boiler pressure, is available to accelerate
the flywheel.
The fact that a flywheel running with a rim speed of
90 ft. per see. has a smaller factor id' safety than one
running at 60 is too obvious to mention, yet it may he
well to point out again that tne stress from centrifugal
forces increases as the square of the velocity, is 2' j times
as great at HO as at CO ft. per sec. and that if the en-
gine runs away the wheel will hurst in less time starting
from a rim speed of 90 than of (JO ft. per sec.
P. II. Williams.
New York City
-isr,
P 0 W E E
Vol. 41, No. 17
[In the case of a runaway engine the comparison is
between the piston .-pcd attained and not that at which
the engine is rated. At the end of a number of seconds
the piston speed of a runaway engine might be greater
if the piston speed to start with were 900 ft. per miii.
than if it were 600, but it is not at all likely that it
would be \V-> times as much — Editor.]
nirag
sxs5 aimed! Wafi©ir°
©SE©2»§
With reference to J. C. Hawkins' article under this
heading in the .Mar. 9 issue. 1 wish to call attention to
the statement, "The roller expander, which gives the
best results and is generally used, consists . . ."
There was a time when the roller expander gave best
results, because the prosser was undeveloped, but now-
adays the sectional expander is more generally used.
Both types have their good and their bad points. The
roller expander does not bind the tube as firmly to the
sheet as does the sectional tool, and there is always
danger of rolling the tube too thin, although there is
less danger of this with the sectional expander. The
principal danger connected with the use of the sectional
tool, according to the findings of the engineers of a
large Eastern railroad, is that the tube sheet is liable
to be cracked or unduly stressed. So far as I know,
there are no other defects of this type A few years
ago the roller expander was regarded as faster than
the sectional, but the latter seems now to be well received.
W. P. SCHAPHOBST.
New York City.
Every engineer at some time has to solve the little
problem of the size of pipe required to equal two or more
other pipes, and although this is not a difficult mathemat-
ical problem, it involves square root, and that is a thing
many prefer to do without. The sim-
plest way to arrive at the solution is to
use a chart, as shown, which gives the
answer by direct measurement.
The rule is to fix the sizes of the two
pipes, one on each scale of a square. The
diagonal distance between these two
points is the diameter of the pipe re-
quired.
For example, for a pipe to equal two
2-in. pipes, measure the diagonal from
2 in. on one side of a square to 2 in. on
the other; the result is 2|| in., the size
Graphic Method of Proportioning Pipe Sizes
pipe which would be sufficient; but 3-in. is the nearest
commercial size.
The line from 3 to 1 marked 5 is just a reminder of the
method of constructing a square. With 3 on one side
and t on the other and the diagonal distance 5, the
first two lines will be at right angles to each other, and a
square is produced. The result will be the same whether
the pipes are measured in any linear unit or simply
pieces of wood cut or marked to length, so long as they
arc equal to the pipe diameters.
Mathematically, the operation is to multiply the
diameter of each of the smaller pipes by itself (as 3X3
= 9 and i X 4 = 16) and add them together (9 +
16 = 25) ; then any larger pipe the diameter of which
similiarly multiplied by itself equals or comes nearest the
other amount (as 5 X 5 = 25) will have approximately
the same carrying capacity as the other two.
With piping of more than 6-in. diameter it is better
to use the square root of the fifth power proportion, but
this brings us up against a root again and so is outside
the present scheme. Still, it gives 8 in. for a combination
of two 6-in. pipes instead of 8y2 in. as given by the
chart, so the chart is on the safe side.
E. Hampton.
Concepcion, Argentine.
sS
IBlowofi? Papain^ Fsslltunres
Reference is frequently made to blowoff pipe failures
and fatalities. Some of the fool things done are almost
beyond belief. In a plant in which I operated the night
shift the blowoff pipe was made up by screwing a nipple
into the cracked outer end of the valve as far as it would
go, then backing it out an indefinite number of turns on
entering the other end into the next fitting. The piping
was frequently disconnected and connected up again by
the foregoing process. I chanced to step on the pipe in
passing and it fell apart, after which I refused to blow
down the boiler on account of this connection, so the
owner gave it a "gingerly" little blow night and morning.
One day a new man, who was not familiar with the
situation, nearly lost his life by opening the valve wide,
which caused the pipe to give way. Such negligence
seems to me to be criminal.
J. N. Woodruff.
West Liberty, Ohio.
m
ILusibiriicattSimg C<Dssaaimusfta^©s*s
I have been reading with interest the articles on the
care and management of direct-current generators and
motors and will mention a method of commutator lubri-
cation that I have found entirely satisfactory. Since em-
ploying it I have had no trouble, whereas previously I had
to give the commutators my attention every few hours. I
take some %-in. square flax packing that has been treated
with beeswax and tallow, cut a piece the length of the
commutator bars and lay it on in front of the brushes,
the friction holding it in place. A piece that will just
tit between the end of the brush-holder and the commu-
tator with a little pressure is better, for the friction holds
it up against the brushes and there is enough lubricant
from the packing to keep the brushes well lubricated.
The wiping effect on the commutator keeps it clean and in
a few days a nice polish will be observed.
After running the machine for a week or so, note if
there is any copper wiping over the mica ; if there is, sim-
ply take a sharp file and undercut the latter a little.
C. E. CuiIMlN'liS.
Boulder, Colo.
April ••>:, 1915 P(J\Y E B 5%',
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiui iiiiiiiiiiiiiiiiiiiiiiiiiini iimiiiiiiiiiiniiiiiiiiiiiuiiiiiiiiiiiiiiiiiiiiniiiiiiNiniiiNiiiiiiiiiii mi iiiiiiiiiiniiiiiiiiiiiiiiiii am iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiini nun iiiihiiiiiiiNiiiiiiiiiiiiiiiiiiiiiiiiuiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiing
1
ft :;:;;;,r;iu,|.iii/'iiir .-■ 1 1- ::■■=. i ■ i : ; : Tilhl' !:vi:!:m i II!!''!"!'!'!!!:! :-"'' ii!ilil"ill!i:illlll' iinii
iii:ii!ii: !:::ii:iiiiiiii!!ii;:' ;.i
End Play of Crankshaft — What may be the causes of end
play of the shaft of a vertical engine?
F. J. I.
Endplay may be caused by the crankpin brasses being out
of line and bearing alternately on opposite ends of the crank-
pin, or to the shaft being out of line causing a wobbling mo-
tion of the flywheel, or in a single-crank engine, to lost mo-
tion in the crankshaft bearings.
Breakage of Firebox Stay-Bolts — What is the cause of
breakage of the ordinary form of firebox stay-bolts?
J. M. B.
The chief cause is unequal expansion of the two sheets
which are connected, one being usually in full contact with
the fire and the other being heated only to the temperature
of the confined water. This difference in temperature of the
sheets gives rise to considerable relative motion between the
two sheets resulting in formation of cracks in the stay-bolts
near the inner surface of the sheets.
I se of BoIIer-Tnbe Ferrules — What is the purpose of us-
ing ferrules on the ends of boiler tubes?
G. B.
Ferrules are used where the effects of expansion are severe
upon the tube ends, as in locomotives and boilers having fire-
box tube sheets. Soft-copper ferrules are also used for filling
tube-sheet holes that are too large for properly receiving
the expansion of the tube ends. In cases where the tube ma-
terial is especially weak or thin and is therefore likely to
spring back when expanded, strong ferrules of hard brass or
steel are driven inside of the tubes at the ends.
Position of Crankpin at Half-Stroke — In a horizontal en-
gine does the crankpin stand vertically over or under the
shaft when the piston is in the middle of its stroke?
W. L.
It cannot, for when the crosshead is in the middle of its
stroke the distance from the center of the crosshead pin to
the center line of the shaft is equal to the length of the
connecting-rod, and as this is less than the distance from
the center of the crosshead pin to the center of the crankpin
when vertically over or under the center of the shaft, the
crosshead must be at some distance from half-stroke toward
the shaft for the connecting-rod to place the crankpin ver-
tically over or under the shaft.
Maximum Capacity of a Boiler — What is meant by the max-
imum capacity of a boiler?
H. G.
The term refers to the boiler's highest rate of evaporation,
or the largest number of pounds of water the boiler can
evaporate per hour under stated conditions of temperature
of feed water and pressure of steam generated. For purposes
of comparison the evaporation under actual conditions is
usually expressed in the equivalent evaporation from feed wa-
ter having a temperature of 212 deg. F. into steam at atmos-
pheric pressure, and as steam at that pressure would have
the same temperature, the standard is generally referred to
as "evaporation from and at 212 deg. F."
Degrees Baumf- and Specific Gravities — In stating the den-
sities of liquids, what are the relative values of degrees Baume
and specific gravities?
J. R. C.
For liquids heavier than water the relative values are
given by the formulas.
Specific gravity = 145 -=- (145 — deg. Be.)
or
Degrees Baume = 145 — (145 -j- sp.gr.)
and for liquids lighter than water the relative values are
given by the formulas.
Specific gravity = 140 H- (130 + deg. Be.)
or
Degrees Baume = (140 -i- sp.gr.) — 130.
Case-Hardening Steel Governor Pius — How can steel gov-
ernor pins be case-hardened?
M. G.
Case-hardening can be performed by heating the pin to a
dull-red color, and after covering with pulverized cyanide of
potassium or prussiate of potash the surfaces which are to be
case-hardened, the operations of heating and coating are to
be repeated. After the pin has cooled down almost to a
black it is to be plunged in water and left until perfectly cold.
In heating the pin the temperature should be raised gradually
and so as not to burn or scale any wearing surfaces. The
chemicals employed are violent poisons and care should be
taken in handling them. A good way to coat the heated pin
is to roll it over the pulverized chemical when spread out on
a flat plate .
Resulting Temperature of Mixtures — What is the method
of determining the resulting temperature of a mixture of
two substances having different temperatures?
J. F.
The final temperature of a mixture of two substances of
different initial temperatures is given by the formula:
(W X S X t2) + ( w X s X t,)
T =
(W X S) +(w X s)
in which
T = Final temperature of the mixture;
W = Weight of the hotter substance;
w = Weight of the cooler substance;
S = Specific heat of the hotter substance;
s = Specific heat of the cooler substance;
t. = Initial temperature of the hotter substance;
t! = Initial temperature of the cooler substance.
To Find Kadius of Bumped Head — Knowing the diameter
and height of bumping of a steam drum head what is the
formula for determining the radius to which the head is
bumped?
L. B. R.
In the figure if
R = The radius to which the head is bumped,
d = The diameter of the head, and
H = The height to which the head is bumped,
then
R>
-©'
+ (R — H)a
from which
0"
that is. the radius of bumping is equal to the square of the
diameter divided by eight times the height of the bump, plus
one-half of the height.
Boiler Efficiency — What was the efficiency of the boiler
and grate using 14.27S lb. of coal having a calorific value
of 13.000 B.t.u. per lb. for evaporation of 11,315 gal of water
from a feed temperature of 170 deg. F. into steam at 110 lb.
gage pressure?
V K. S.
Allowing SJ lb. per gal., the water evaporated amounted
to
11,315 X 81 = 94,291.6 lb.
and the pressure of the steam was approximately
110 + 15 = 125 lb. per sq.in. absolute.
Referring to Marks and Davis' steam table it is seen that
at 125 ib. absolute, each pound of steam contains 1190.3
B.t.u. above 32 deg. F., and as the temperature of the feed
water was 170 deg. F., or 170 — 32 = 138 deg. F. above 32
deg. F., each pound of feed water must have received
1190.3 — 13S = 1052.3 B.t.u.
so that the total heat received from the boiler was
94,291.6 X 1052.3 B.t.u. = 99,223,050.6S B.t.u.
and as the coal contained
14.27S X 13,000 = 185,614,000 B.t.u.
the efficiency was
(99,223,050.68 X 100) -=- 1S5. 614, 000 = 53.4 per cent.
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR]
P O W E 17
Vol. 41, No. 11
The illustration. Fig. 1, is a semiseetional view of the
new Cookson return steam trap. The device is compact,
simple and positive, and it has a powerful valve mechan-
ism. It is easily accessible, is regrindahle, and the disk
and reversible scats arc made of monel metal.
Tin operation of the trap is simple. Pig. 1 shows it in
a filling position with the boiler pressure on the outlet
Fig. 1. Semi-Sectional View of the Trap
check valve. When the returning condensation is to go
to the boiler, the trap is located three or four feet above the
water line, so that the water will drain to the boiler by
gravity. If any returns are below the water line the pres-
sure on them must be sufficient to elevate the water into
the trap.
The accumulation of a given amount of water in the
trap causes an upward movement of the float, Fig. 2,
which communicates with the valve mechanism to the
counterbalanced quadrant and connecting-rod. This ac-
tion tilts the weighted valve lever, which opens the steam
valve and lets the boiler pressure into the trap, closing
the check valve on the inlet end. With the pressure in the
boiler and in the trap equalized, the water tlows to the
boiler by gravity. After discharging, the floats drop ami
the weighted valve lexer is tilted to its former position,
automatically venting the trap of boiler pressure, and
allowing condensation to flow into it until a sufficient
amount has again accumulated to cause it to repeat the
operation of discharging into the boiler.
To provide against any loss of steam a water seal of sev-
eral indies remains in the trap after each discharge. Fig.
2 shows a detailed drawing of the trarj and the valve-
operating mechanism. The only thing in the body of
the trap is the high-pressure float that actuates the valve
mechanism. The design of the valve and seat makes
it possible to regrind them while the trap is in operation.
As the valve mechanism is on the outside of the trap it
is easily accessible, and its movement indicates whether
the trap is in operation or not. This trap is manufac-
tured by the 1). T. Williams Valve Co., Cincinnati, Ohio.
ig-\ r*
Fig. 2. Details of the Thai' Construction
April 27, 1915
r OWEE
589
Fr&cttiiomisdl Horsepower Motors
I'.i Bern a bd Lester
SYNOPSIS Tin development in the design mi, I
construction of the single-phase motor is traced
from its origin in the present Him-, and the operat-
ing characteristics of the commoner types of single-
phase motors am described and illustrated liy the
use of speed-torque curves.
During the last ten years the field for the use of fractional
horsepower motors has increased enormously and many new
devices have become available commercially. There have
been three principal causes for this development in the small-
motor field:
1. Efficiency engineering: in every field of endeavor has
brought to the mind of the public the realization of the
saving that can be accomplished in time, labor and money by
operating small appliances electrically.
2. Wide distribution of central-station circuits, primarily
for the purpose of lighting, has greatly increased the possible
field for the use of small motors.
3. The performance of the small motor as a reliable
source of power and its proper application have established
the confidence necessary to encourage the investment of time
and money in the development of the industry.
Since single-phase, alternating-current distribution is so
largely employed for lighting and, consequently, is available
as a supply for small motor-driven machines, the develop-
ment of a simple, reliable and efficient small single-phase
motor has had a large share in the growth of this industry.
Single-phase motors of the series, repulsion or induction
type, or some modifications or combinations of these principal
types, have been largely used.
Seri» Motob
The series single-phase motor, owing principally to its
varying speed with change in torque, has a limited applica-
tion. It can be safely used only where the load is rigidly
connected to the driving shaft and where large variations
in speed are permissible with variations in load. This type
of motor is successfully used with fans attached to the motor
shaft, and for exhausting or supplying air, as in the case
of fan-type vacuum cleaners or forge blowers; also for
portable electric tools, in which case the power is turned
off when the tool is not in actual service. Its use, however,
is limited to these or similar applications. A great advantage
in the series motor, when especially constructed, is that it
can be operated upon direct current or alternating current
of most commercial frequencies and t'he same voltage, with
speed-torque characteristics sufficiently similar to produce
results generally satisfactory in motors of small capacity.
Kepulsiux Motob
The single-phase repulsion motor, which is a modifica-
tion of the series motor, possesses in general the same
limitations in regard to its speed-torque characteristics as
the series motor. However, without load it does not attain
the same dangerously high speed. Since the brushes are
short-circuited, the interchangeability from alternating- to
direct-current circuits does not exist.
Induction Motob
The single-phase induction motor possesses a speed-torque
characteristic in which the speed holds practically constant
under a varying torque. This is well suited to the large
majority of small motor-driven machines, provided a means
is supplied to bring the rotor up to a speed at which the
inherent torque produced is sufficient to accelerate the load.
The split-phase induction motor is by far the most common
type in fractional horsepower sizes. The most difficult
problem has been in overcoming the absence of starting
torque in the simple single-phase motor, and the principal
steps in this development will be mentioned.
The first split-phase, self-starting motor was developed
by Tesla and used for driving small desk fans, but was not
employed generally for power service. Several years later,
about 1S93, single-phase induction motors of larger capacities
were developed and used, but as there was no device for
starting the motor, it had to he started by hand. Like any
polyphase induction motor, when connected to a single-phase
circuit and operated on one phase only, it would run in either
direction, if started by some external force and accelerated
to a point at which the torque developed by the primary of
the motor upon the rotating element was sufficient to carry
the rotor up to speed. The speed-torque curve of such a
motor is shown in Fig. 1, curve AD. From 1S93 to 1895
self-starting split-phase motors were designed with two
windings in the primary — one for running and the other for
starting. A phase splitter, consisting of a manually operated
external switch and resistance, connected the primary wind-
ings to the supply circuit and inserted resistance in the start-
ing winding. A phase displacement in this way existed
between the currents in the two windings, which exerted
a torque upon the rotor in starting, the starting winding and
resistance being cut out as soon as the motor came up to
speed. Later, motors were designed with starting devices
supplied with a condenser in place of a resistance. This
produced a greater angular advance'in the phase displacement
than was the case with the resistance starter. In this
particular, therefore, a somewhat improved operating char-
acteristic was obtained, due to higher power factor, the
condenser remaining in the circuit while starting and running.
About lsus single-phase induction motors were designed,
which started as series motors. The secondary winding was
similar to that of a series motor, the commutator bars being
short-circuited as the armature accelerated, after which the
motor ran as an induction motor. Shortly after this an
advantage was found in starting as a repulsion instead of a
series motor, since the motor so constructed could be con-
nected externally for use either upon 110- or 220-volt circuits.
Motors designed in accordance with this principle are now
widely used, especially in sizes above % hp. An automatically
operated centrifugal governor within the rotating element
short-circuits the commutator bars. Curve B, Fig. 1, shows
■ the speed-torque characteristics of such a motor while start-
ing compared with that of the induction motor (curve AD).
The line ab represents the speed at which the motor auto-
matically switches from a repulsion to an induction motor.
Another development in the split-phase motor was in the
use of an external clutch or clutch pulley. Owing to difficulty
in obtaining sufficient starting torque to enable the motor
to be used for other than accelerating very light loads, cen-
trifugal clutches were used, allowing the rotor and shaft to
accelerate to a point at which a liberal torque was exerted
Excerpts from paper presented at Cleveland Section.
. E. E . Mar. 19, 1915.
50 100 150 200 250
Torque in Terms of Full Load, Per Cent.
Km. I. Speed-Tobque ( Iubves
by the rotor; at this point the clutch took hold and applied
the load to the motor. Within the past few years marked
improvements have been made and sufficient starting torque
can now be obtained without the use of a centrifugal clutch,
for many classes of service. A light, high-resistance starting
winding, in addition to the running winding, is used.
Curve AC, Fig. 1, shows a typical speed-torque of such a
motor. This starting winding is cut out by means of a
centrifuga'.ly operated switch placed within the motor and at
a speed slightly below that corresponding to full load.
590
P ( ) W E R
Vol. 41, No. \:
It is interesting to note that small-motor engineers
encounter almost identically the same problems as those
which apply to larger industrial motors, in so far as cycles ot
operation and speed-torque requirements are concerned. For
instance, in the application of small motors to washing
machines with wringers, the wringer is the limiting feature,
taxing the motor with sudden peak loads. This application
may well be compared with a motor-driven rolling mill. The
*- - : j\ Points ot which storting
■vindinqs open
~ — Point at which clutch operates
Full Lood Current
12 3 4 5
Seconds
Fig. •.'. Curves showing Starting Current
10 Chicago, 111 845 South Wabash A\
11 Minneapolis,
Minn Federal Building
12 si Louis, Mo.. . . Chemical Building ... .
13 De
tog-
Illinois, Indiana, Michi-
gan, Wisconsin.
Minnesota, North Da-
kota. South Dakato.
Mi: — uri. Kansas, Okla-
homa, Iowa.
Colo Central Savings Bank Build- Colorado, Wyoming, Ne-
braska, Utah.
Montana, Idaho.
Power Building
15 Si attle, V\ ash Fifteenth Avenue, w est and
Blaine Streets
16 Portland, Ore Railway Exchange Building.
17 San Francisco, Cal Angel Island
18 Los Angeles, Cal Post Office Building
Washington.
Oregon.
California, north of the
northern boundary of
San Luis Obispo, Kern,
and San Bernardino
Counties; also State of
Nevada.
California, south of the
northern boundary of
San Luis Obispo, Kern,
and San Bernardino
Counties; also State of
Arizona.
All of the postmasters throughout the United States are
cooperating in this work by distributing application blanks
both to employers and employees. The appropriate blanks
may therefore be had on request to any postmaster. How-
ever, in those cities designated as zone headquarters applica-
tion for blanks or information should be made direct to the
Inspector in Charge of the Distribution Branch at the office
of the Immigration Service at the address indicated in the
foregoing table.
motor-driven meat grinder compares closely with the motor-
driven pulp-mill beater, and the coffee grinder with the
rock or stone crusher. In the design of high-speed motors
for fan-type vacuum cleaners, the problems closely parallel
those of the high-speed turbo-blower.
In applying split-phase motors, aside from the general
characteristics outlined elsewhere, special attention must be
given to those characteristics of starting torque, pull-out
or maximum torque and temperature rating. The starting
torque varies approximately as the square of the impressed
voltage; consequently, any reduction in the voltage of the
circuit produces more than a proportional reduction in torque.
Furthermore, the starting" current of split-phase motors
materially exceeds the full-load running current. This factor,
in addition to light wiring or insufficient transformer capacity,
often results in a reduction in starting torque. Good practice
in small-motor application provides that the motor should
be able to start the driven machine when the impressed
voltage is as low as 20 per cent, below the rated voltage.
A centrifugal clutch is often incorporated in the design of
the motor, not only to insure an ample starting torque and
reduce the effect of the current taken during starting, princi-
pally by cutting down the time during which it is taken,
but also to provide an element of flexibility in the case of
a machine rigidly connected to the motor. The clutch will
slip in the event of sudden or extreme overload, thus pro-
tecting the combined unit.
X
Hew Fedleiral EmptosHnmeiatt
The Department of Labor, through the Division of Informa-
tion of the Bureau of Immigration, has recently established
distribution branches throughout the country for the purpose
on the one hand of developing the welfare of the wage earners
of the United States and improving their opportunities for
profitable employment, and on the other hand of affording
to employers a method wThereby they may make application
for such help as they need, either male or female, citizens
or alien residents, and have their wants supplied through the
distribution branches. No fee is charged employer or employee
for this service.
The following is a list of the headquarters, together with
the states comprising the zone or jurisdiction over which they,
respectively, have control:
Zone Location of States or Territory
No. Branch Local Address Controlled
1 Boston. Mass Long Wharf Maine, Massachusetts,
Rhode Island.
2 New York, N. Y.. United States Barge Office . . New York, New Jersev,
Connecticut, New
Hampshire, Vermont.
3 Philadelphia . Penn. Gloucester City, N.J Pennsylvania, Delaware.
West Virginia.
4 Baltimore, Md Stewart Building Maryland.
5 Norfolk, Va 119 West Main .Street Virginia, North Carolina.
6 Jacksonville, Fla.. Federal Building Florida, Georgia. Ala-
bama. South Carolina
7 New Orleans, La. Immigration station Louisiana, Mississippi,
Arkansas. Tenness r
8 Galveston, Tex .. . Immigrate n station Texas, New Mexico.
9 Cleveland, Ohio. . Post Office Building Ohio. Kentucky.
Wes&esna H^dls*©^!
ID @v © 1 ©pern © iaH
The Montana Power Co., which is attempting to enter the
Cceur d'Alenes, Idaho, in competition with the Washington
Water Power Co., has 101,000 hp. of hydro-electric plants in
operation, 120,000 hp. under construction, 127,000 hp. of unde-
veloped water-power sites and S000 hp. of steam reserve. A
second unit of Prickly Pear Valley irrigation project will
be completed this spring and an additional 3500 acres served
with water in 1915.
During the last three months of 1915, according to the
report for the year ending Dec. 31, 1914, the company expects
to receive a large additional revenue from railway electrifica-
tion now under way on the Chicago, Milwaukee & St. Paul Ry.
The Great Falls hydro-electric plant, which will have an
ultimate capacity of 80,000 hp., will be in operation in July,
and four of the six units of installation will be completed
in the present year. Current is expected to be furnished
from the Thompson Falls plant by June. Two units will
be installed this year and two added as demanded. About
75 per cent, of the work at these two developments has
been completed The Hauser Lake plant has been increased
to 34,400 hp. and the Black Eagle plant to 5100 hp. Sixty-
seven miles of additional transmission lines were placed in
operation in 1914.
National Association of Stationary Engineers, Columbus,
Ohio, Sept. 13-18.
American Order of Steam Engineers, Atlantic City, N. J.,
June 21-25.
Universal Craftsmen Council of Engineers, Rochester, N.
Y., Aug. 3-7.
Canadian Association of Stationary Engineers, Hamilton,
Ont., July 2 7 - 2 r< .
N. A. S. E. STATE CONVENTIONS
California
Colorado
Connecticut
Illinois
Indiana
Iowa
Kansas
Kentucky
Michigan
Minnesota
Missouri
New England
New Jersey
New York
Ohio
Pennsylvania
Texas •
West Virginia
Wisconsin
San Francisco
Denver
Hartford
Decatur
Richmond
Clinton
Wichita
Lexington
Jackson
Mankato
St. Louis
Holyoke. Mass.
Trenton
Auburn
Columbus
Pittsburgh
Dallas
Clarksburg
Sheboygan
V
May 27-28
Aug. 6
June 25-26
May 2K-2S
June 9-12
June 2-4
May 5-7
June 10-12
June 23-25
July 7-9
May 19-21
July 7-10
June 3-6
June 11-12
Sept. 12-13
June 18-19
The Temperature at Which « atf r Boil.s depends on the
pressure upon its surface. At 1 lb. absolute its highest tem-
perature is 102 deg. F. ; at 14.7 lb., 212; and at 300 lb.. 4 17".
deg. (see steam tables).
April 3T, 1015
P 0 W E R
591
IReceffiift Cotnurft Decisions
Digested by A. L. H. STREET
Duty to Snfeguard riiildren Against Wires — An electric-
power company which knew that boys were accustomed to
play on a wall near an electric wire carrying a dangerous
voltage was bound to maintain the wires in safe condition,
and, therefore, is liable for the death of a boy who came in
contact with a wire where it was uninsulated, according to
the decision of the New York Supreme Court announced in the
case of Meehan vs. Adirondack Electric Power Co., 150 "New
York Supplement," 714.
Care in Handling Electricity Standardized — The degree of
care required in the maintenance of electric wires is declared
by the Washington Supreme Court, in the recent case of Card
vs. Wenatchee Valley Gas & Electric Co., 137 "Pacific Re-
porter," 1047, to depend upon the character of the current
carried, slight care being sufficient where the current would
not injure persons coming in contact with it and the highest
care being required where the current would cause death or
serious injury. The court finds that the jury were warranted
in finding that an electric-power company was negligent in
failing to insulate a high-power wire which was strung only
17 ft. above the land of one who was killed through inad-
vertently bringing a pipe in connection with the wire while
repairing an irrigation ditch.
Proving Negligence in Explosion — In suits for injuries
from boiler explosions, it often becomes difficult to establish
the cause as a basis for holding the owner responsible if it
appears that the accident was due to negligence attributable
to him. This question arose in the recent case of Gill vs.
Brown (169 "Southwestern Reporter," 752), which was passed
upon by the Tennessee Supreme Court, and it was sought to
hold an employer liable for injuries sustained by plaintiffs
while at work in the former's sawmill, caused by the ex-
plosion of a steam boiler, on the theory that the mere oc-
currence of the explosion raised a presumption of negligence,
in the absence of affirmative proof to the contrary on the em-
ployer's part. But the court held that the mere fact of an
explosion does not change the rule of law which places the
burden on the plaintiff in every personal-injury action to
clearly establish the fact that the injury complained of was
produced by some negligence attributable to the defendant.
The court, however, held that proof in this case that the boiler
was very old (the evidence tended to show that it had been
used for 40 years) and the finding of several rusted rivets in
the wreckage warranted a finding that the boiler had been
negligently permitted to remain in a dangerously defective
condition.
Alfred Kauffmann is now vice-president of the Link-Belt
Co. in charge of operations at Indianapolis. Mr. Kauffmann
served in the engineering department at Philadelphia for a
number of years, from which he was promoted to take charge
of the erection work of the company. He was later transferred
to the sales department, looking after the coal-mining business
in the East and particularly in the West Virginia field. His
many friends will be glad to learn that in recognition of his
competent and able "work he has been elected vice-president
of the Link-Belt Co.
The American Iron and Steel Institute will hold its eighth
general meeting at the Waldorf-Astoria, New York, on May
28 and 29. The program, which will be announced in the
near future, will contain only a few formal papers in order
to encourage informal discussion.
The Detroit Engineering Society announces the following
meetings: May 7 Mr. John O'Connor, Jr., of the Mellon Insti-
tute of Industrial Research, will speak on "Some Points in the
Indictment of the Smoke Nuisance;" May 21 Mr. H. M.
Brinckerhoff is expected to give his deferred talk on the
"Detroit Traffic Situation."
Boston Association No. 12, of the National Association oi
Stationary Engineers, will celebrate its twenty-first anni-
versary with a ladies' night at 995 Washington St., on the
evening of May 3. All members of the N. A. S. E. and their
families are invited to be present.
Pratt Institute, Brooklyn, N. Y„ exhibits the work of day
Students on Apr. 29, 2 to 10 p.m.; Apr. 30, 10 a.m. to 10 p.m.,
and .May 1, 10 a.m. to 5 p.m. The students will be engaged at
their regular work, and the engineering public is invited to
inspect especially the methods and equipment of the School
of Science and Technology.
International Engineering Congress — Volume II of the
Transactions of the International Engineering Congress to be
held in San Francisco, Sept. 20 to 25, will comprise two series of
papers, one on the subject of waterways and one on irrigation.
The former subject will be treated under four general topics
with possibly two additional. These topics cover the general
field of the province of waterways in internal commerce,
economic aspects, physical features, natural waterways, tow-
age and propulsion. Irrigation will be treated under 11 topics
covering: Methods of handling irrigation enterprises; duty of
rater; relation between demand and supply; underground
sources; stream sources: tail water from hydro-electric plants;
regulations for use; methods of charge; metering; drainage:
dams in general; and also recent developments in India and
in the Argentine Republic. This volume will comprise from
20 to 25 original illustrated papers, together with contributed
discussions. The transactions of the Congress as a whole will
include from seven to nine other volumes, covering the various
fields of engineering work. Membership in the Congress with
the privilege of purchasing any or all of the volumes of the
proceedings is open to all interested in engineering work. Full
particulars may be obtained from W. A. Cattell, secretary.
417 Foxcroft Building, San Francisco, Calif.
DIRECT-ACTING STEAM PUMPS. By Frank F. Nickel. Mc-
Graw-Hill Book Co.. Inc., New York. Cloth; 25S pages,
6x9 V4, in.; 218 illustrations; tables. Price, $3.
ENGINEERING ECONOMICS. By J. C. L. Fish. McGraw-Hill
Book Co., New York. Cloth; 217 pages, 6x91,2 in.; illustra-
tions; tables. Price, $2.
STEAM TURBINES. Bv James A. Moyer. Published by John
Wilev & Sons, New York, 1915. Second edition. Cloth;
376 pages; 6x9 in. Price, $3.50.
While intended as a manual for those operating, designing
or manufacturing steam turbines, an outline of elementary
thermodynamics and of the use of entropy and velocity dia-
grams is given. The part of the text relating to the design
of nozzles and blades is valuable as an explanation of the
theory, but the lack of detailed proportions and dimensions
prevents its being of much use to designers. Since the first
edition was issued, new applications of turbines have come
into use, and accordingly, in the second edition Professor
Moyer has either added or revised chapters on low-pressure,
mixed-pressure and bleeder turbines. The essential elements
of commercial types of turbines are clearly described and the
methods of testing explained. With the exception of the
numbering of the illustrations, the arrangement of the book
is excellent. But to look at Fig. 192, which precedes Fit
in turn followed by Fig. 195, gives the impression that the
illustrations, in reality a most valuable part of the book, were
an after-thought. The volume also contains interesting chap-
ters on power-plant costs, an outline of plant design, and a
theoretical discussion of gas turbines.
POURING OF BABBITT METALS
In a treatise on the "Pouring of Babbitt Metals," the Syra-
cuse Smelting Works, of Brooklyn, N. Y., offers suggestions
which every engineer would do well to follow: Among other
things it says:
Better service may be obtained if you will learn that it is
of the utmost importance to pour babbitt metals at a low
temperature.
When practical, take the chill off the mandrel and shell
by warming, as this will dry off the moisture which causes
blow-holes, and also makes the metal flow better.
On the subject of remelting metals is the following:
Instructions are generally given to stir before pouring.
Those who give these instructions intelligently do so because
the tendency is to pour metals too hot and the stirring lowers
the heat.
This dispels the idea which many engineers have, that tin;
592
POWER
Vol. 11, No. 17
purpose of stirring the molten metal is to reunite the sep-
arated alloy.
To determine whether the melted metal needs cleaning, it
advises that the surface be examined while it is at a fair
pouring heat. If fine, spider-web lines appear on the sur-
face after skimming, the metal is clean.
OXYACETTLENE WELDING AND CUTTING. By Calvin F.
Swingle, M. E., author of "The Twentieth Century Hand-
book for Steam Engineers and Electricians," etc. Chicago:
Frederick J. Drake & Co. Size, 4C,x6% in.; 185 pages; 76
illustrations', indexed. Price, cloth, $1 net; leather, $1.50
net.
This volume deals with many types of generators and
portable apparatus in detail, together with the chemical
properties and considerations of the gases used. There are
numerous illustrations of different types of equipment, with
notes on the mode of operation.
The chapters on torches, their management and character-
istics are instructive, and useful information is given relating
to the consumption of gas and methods of handling, with
illustrations, weights and dimensions of torches in general
use. Actual welding and cutting work could with advantage
have been treated at greater length and illustrated with
practical examples giving information on the work done by
others and conclusions to be drawn therefrom. The impres-
sion that this mode of welding is applicable to everything
should be avoided. While its uses are increasing, other forms
still have a very large field where the oxyacetylene method
is too costly and uncertain in its results. Costs of operation
could also have been dealt with to advantage. The illustra-
tions are not all that could be desired, but the book is well
indexed; and no doubt will find favor among those interested
in the apparatus required but who do not wish highly technical
descriptions.
Though the names of some of the makers of apparatus
are included, they are few. That of the Davis-Bournonville
Co. is an especially conspicuous omission, in view of the great
amount of pioneer work which this company did in introducing
the art into this country. Some authors inject too much
advertising into their books to have them wholesome, but
this one seems to have gone to the other extreme. Credit
should be given where credit is due, especially when it will
be of actual interest to the reader.
PREVENTING LOSSES IN FACTORY POWER PLANTS. By
David Moffat Myers. New York: The Engineering Mag-
azine Co. Cloth; 5HX7V2 in.; 560 pages; 6S illustrations.
Price, $3.
That the saving of coal in our industrial plants is neces-
sary for the present generation, as well as those to come,
can hardly be denied. The monetary saving effected today,
while enabling us to procure certain improvements in our
plants, to give better working conditions to our employees,
higher wages, and increased dividends, is only one side of the
question: possibly that uppermost in our minds, but the conse-
quent conservation of our available coal fields is of greater
importance to posterity.
Power-plant efficiency has made considerable progress in
the past few years, but still not as great as efficiency applied
to other lines of business, possibly because the efficiency engi-
neer meets with greater obstacles in this field. It is usually
easy to convince the manager of an industrial plant of the
advisability of installing a machine that will enable him to
cut down lis labor or double his output; it is simply a matter
of the co:.t of the machine installed and its earning power.
"When the efficiency engineei seeks to impress this same
man with the saving that can be effected through the employ-
ment of proper methods applied to the coal pile, he usually
meets with considerable uphill work, and frequently with
ill-concealed skepticism. Managers and owners, when ap-
proached on this subject, are prone to reply that they have
made very good arrangements with their coal dealer, that
they have good firemen, the steam they are allowing to go
up in the air does not amount to much anyway, and kindred
other replies only too familiar to engineers that have tried
to lead them back to the path of efficiency. Some again, will
realize that there is waste in exhausting to atmosphere, the
use of bare steam pipes, the use of long and badly arranged
shafting, the unintelligent handling of boilers and coal.
These men are indeed wise and. regrettably, 1 30 few.
The work under review deals "with this important subject
in a clear and illuminating manner and should be of great
benefit to all engaged either in the owning, operating, design-
ing or rehabilitating of power plants, great or small. The
theory and practice are ably explained. Every item of loss,
with its consequent result, is traced in successive steps from
its origin back to the coal pile. Methods of prevention,
together with actual examples from the author's wide experi-
ence, are carefully shown.
The engineers at present exploiting this field, or those
who may have this intention, would do well to read this
work and apply the principles therein. Many useful tables
and tabular results of actual tests are given.
The author undoubtedly intends the volume to be read in
its entirety, as no index is provided. The subject, to be
thoroughly appreciated, must be completely read.
BUSINESS ITEMS
Arthur G. McKee & Co., contracting engineers, of Cleve-
land. Ohio, have issued an attractive brochure, elaborately il-
lustrated with examples of their work.
The Indiana Steel Co.. Gary, Ind.. has installed "Diamond"
Soot Blowers, made by the Diamond Power Specialty Co., De-
troit, Mich., on 26 boilers.
The Chicago Pneumatic Tool Co.. Chicago, 111., has re-
moved its New York office from 50 Church St. to 52 Vander-
bilt Ave., and its Boston office from 191 High St. to 1S5 Pleas-
ant St.
L. R. Merritt & Co. has removed its office from 95
Liberty St. to larger quarters in the Vanderbilt Concourse
Bldg.. 52 Vanderbilt Ave., New York. This company represents
the Brownell Co., Springfield Boiler & Mfg. Co., Craigs Ridg-
way & Son Co., Coppus Engineering & Equipment Co., Ad-
vance Pump & Compressor Co., James McMillan & Co.
The Harrison Safety Boiler Works, 17th and Clearfield St.,
Philadelphia, Penn., is sending out Cochrane "Engineering
Leaflet" No. 18. This 48-page booklet contains an article by
W. S. Giele entitled "Laboratory for Investigating and Testing
Liquid Flow Meters of Large Capacity" and an article by
James Barr, B. Sc, entitled "Experiments Upon the Flow of
Water Over Triangular Notches." Copies are mailed on re-
quest.
Bird & Son. E. Walpole. Mass., has recently ordered of
Builders Iron Foundry', Providence, R. I., a venturi meter with
type M indicator-recorder for boiler feed service. This con-
stitutes the fourth venturi meter installed by this company
for measuring boiler feed water. The Inland Steel Co., of
Indian Harbor, Ind.. recently ordered an S-in. venturi meter
tube with type M register-indicator-recorder for boiler feed
service.
"Retail Coal Pockets, Third Edition" is now being dis-
tributed by the Guarantee Construction Co.. 142 Cedar Street,
New York. Specialists in constructing buildings and appa-
ratus for handling coal and ashes for power plants. This 32
page 6 by 9 booklet illustrates many pockets recently erected
by them, describes modern coal handling methods, and ex-
plains which are most suited to various conditions. A copy
will be mailed on request.
Recent installations of American standard copper coil feed
water heaters, made by the Whitlock Coil Pipe Co., Hartford,
Conn., include: Hainesport Mining & Transportation Co.,
Philadelphia, Penn., 600-hp. for its dredge "Philadelphia;"
Lake Champlain Transportation Co.. Whitehall, N. Y., 100-hp.;
L. M. Hartson Co., No. Windham, Conn., 50-hp.; Metropolitan
Water and Sewerage Board, Boston, Mass.. 150-hp.; Chatham
Bars Inn, Chatham Bars, Mass., S0-hp.; Brawn-Willard Co.,
Portland, Maine, 100-hp.; Rhode Island Mill, Spray, N. C,
500-hp.; Northwestern Electric Co., Portland, Ore.
* Wanted, 3 cents a word, minimum charge 50c.
Positions Open. (Civil Service examinations). Employment Agencies (Labor
Bureaus), Business Op portunlties. Wanted (Agents and Salesmen — Contract
Work). Miscellaneous (Educational — Books), Eor Sale. 5 cents a word, mini-
mum charge. S1.00 an insertion.
Count three words tor keyed address care of New York; four for Chicago
Abbreviated words or symbols count as lull words.
Copy should reach us not later than 10 A.M. Tuesday for ensuing weeks Issue
Answers addressed to our care. Tenth Ave. at Thirtv-sixth Street. New York or
1144 Monadnork Block, Chicago will be forwarded (excepting circulars or
similar literature).
No information given by us regarding keyed advertiser's name or address.
Original letters of recommendation or other papers of value should not be In-
closed to unknown correspondents. Send copies.
ailing for bids. $3.60 an inch per Insertion. P
POSITIONS OPEN
MASTER MECHANIC for rolling mill. T. 4S7, Power.
A CENTRIFUGAL PUMP DESIGNER with experience <n
designing high-speed pumps of small and medium sizes for
high- and low-head service; applicants must state fully their
experience, age and salary expected. P. 491, Power.
POSITIONS WANTED
CHIEF ENGINEER, employed in central station: seven
years' experience with engines, turbines, dynamos, boilers;
married; age 30. P. W. 4SS, Power, Chicago.
Vol. II
POWER
NEW YORK, MAY 1. 1915
No. 18
!P^sIhi0 Domi'lt KimocSl'
Written by
L. R. W. Allison,
Newark, N.J.
A FAMILIAR PHRASE that has many limes stared
at us from a conspicuous position upon a door;
three sun pit words that arc almost invariably pass-
ed by with entire thoughtlessness, attributing the signifi-
cance directly to only the entrance thus slightly guarded.
BUT stop to analyze, consider more fully the
meaning beyond the external marking and
we find that the expression strikingly pertains
to each one of us and our daily endeavors, con-
veying a teaching of sterling worth.
"Push, Don't Knock" has its limits on the door of the office, it has
no limits on the door of our future. It is erasible from the former,
but it is stamped indelibly on the latter.
Push at the door of the office and it opens just so far; push at the
door of personal advancement, and the more persistent and ener-
getic the push, the wider does it extend.
In this sense, push is progress, and progress is going forward.
The engineer cannot remain as stationary as his engines, he must
move, either slipping up or down the ladder of bigger things.
There are two general classes of men, the pushers and the pushless,
one drives forward and keeps his step, the other is driven forward
and falls backward. One uses his best efforts, the other abuses
them.
The motto of the progressive engineer commences with "Push"
and includes "Don't Knock." This man doesn't cry for a chance
for advancement, he tries for it, and with that real ambition and con-
fidence in his own ability that gets there. The engineer with push
in his makeup embraces every opportunity offered him, and if it
isn't offered, he makes it. he shows right in his own plant what he
can do.
Opportunity is like the live steam line under heavy load, it's never
empty, it's never used up. The pressure back of it is the enthusiasm
that is put into the work of every day. That is the real power
on the job.
To knock is the easiest thing on earth; everyone can grumble,
whine and complain and "knock" his associates, his boss and his
plant. It doesn't require any real ability to do this — it's boy's play.
But did you ever see an engineer who is alive to every chance for
advancement spend valuable time in "knocking"? He's too busy
with something to waste his efforts in nothing.
The long running hit in the game of life is the real demonstration
of your real superiority. Consider it from any angle, you will find
that it is this alone that counts.
To "Push, Don't Knock" is the creed of energy; it's the 9tnall be-
ginning that offers a big ending; it doesn't require deep thinking to
see it. It's the handwriting on the door of opportunity for the man
who will push it open wider and wider without knocking.
591
POWER
Vol. 41, No. IS
,©^uise<
By A. P. Connob
SYNOPSIS This hydro-electric power plant has
been builf to supply electrical energy for construc-
ting the Arrow Rock dam about fifteen miles dis-
tant. Then are three 625-kv.-a. vertical-type
generators, each with its exciter couplet! to the
upper end of the generator shaft. The rolltii/e
of the main units is 2800, which is stepped up
:.000 volts for transmission. When the dam
impleted the plant will be used for supplying
gy for local use.
The project which the United States Reclamation Ser-
vice is undertaking for irrigation purpose? at Boise. Idaho.
lias in reality three natural subdivisions, one being in
long, and which terminates in the Deer Flat Reservoir.
The possible power development i- estimated at 15,000
hji. The power possibilities from the various streams
in the vicinity of the project are great, and a number of
hydro-electric plants have been constructed.
The turbines of the Boise hydro-electric plant, Fig. 2,
rest on the discharge tunnels, thus utilizing short draft
tube-. Fig. 3. The thrust bearings are just above the
wheel pits, and the alternators re»t on the main floor
of the generator room. There are three vertical-type
alternating-current generators, each of 625-kv.-a. capacity,
with exciters mounted on the end of each shaft. The
units generate 2300-volt three-phase current at 60 cycles,
and this is transformed to 22.000 volts for transmission
to the Arrow Rock dam. The generators are synchronized
Fig. 1. Dam and Power House at Boise River
the valley of the Payette, the second in the Boise Valley
and the third in the valley on the north side of the Boise
River. The reference in this article is to the part of the
project which makes use of the Boise River for power
purposes.
The dam across the Boise River, Fig. 1, which makes
its waters available for irrigation and power purposes,
is situated about eight miles above the City of Boise.
The dam raises the water level 33 ft. and diverts water
into a canal extending 23 miles to Indian Creek, the
channel of which is then used for about nine miles, v. here
the water is then directed into another canal, eight miles
on the 22.000-volt side of the transformers, and provision
is made for operating them in parallel. The generators
are of the revolving-field type and have a rating of 500
kw. at 80 per cent, power factor with a speed of 180
r.p.m.
The exciters are supported by the top spiders of the re-
spective alternators. The capacity of each is sufficient
to furnish the maximum field current for two alternators,
plus 10 kw. for local or other requirements. The exciters
are designed to generate direct current at 125 volts. A
regulator is used to control the generator voltage. Fig.
4 is a plan of the plant.
May 1, 1915
POWEE
595
Fig. 2. Generating Units of the Boise Biver Powei; Plant
the station, and is driven by ;i 220-volt induction
motor.
The present capacity of the plant is 1500 kw. A cer-
tain amount of electricity is used for local purposes on the
dam, and some is used by the surrounding community, but
the greater amount is intended and used for the building
of the dam some fifteen miles distant. Nevertheless, the
plant is a permanenl structure and it is proposed to turn
nor] Vjovernor] governor]
\ 3- 625-K.V.A. Generators
Blower \ I80R.P.M. /
j Mi \ J ^Conduits
^J — ' 3- 62S-KVA. Transformers Switch boa rd__
ri-ltm
y Floor of Slucing Tunnels, El. 2773
Pig. 3. Elevation of One oi the Tukbo-Generatob
Sets
The transformers for the alternators are air cooled by
motor-driven blowers. An air compressor having a ca-
pacity of 50 cu.ft. per min. is provided for the a Is oi
K --- <— -j l....i....j.6?:0 >)
Pig. 1. Plan of the Boise Power Plant
the power over to local uses when the Arrow Pock dam
is finished.
The plant is compact, the size of the power house being
about sixty by forty feet. The irrigation canals which
the dams in the project supply with water are in all
about four hundred miles in aggregate length. The lat-
erals from them are in the aggregate one thousand miles,
an indication that the project is of mure than ordinary
consequence and magnitude.
59ti
PO \Y B \l
Vol. 41, No. 18
^rlbiini(
By F. B. Low
SYNOPSIS An explanation, "written so you
can understand it." of the diagrams which show
the working of the strum in turbine blades and
how the energy of the swiftly mucin;/ jet is ab-
sorbed and converted.
To one riding in a railway car a ball traveling along
parallel to the track, as in the line mn, Pig. 1. and with
the same velocity as the car would appear to be stationary
relatively to the car. just as though it were attached
thereto by an invisible rod. If the car slowed up, the
ball, although preserving its own velocity, would appear
to shoot ahead, while if the car speeded up the ball would
appear to be moving backward, with a velocity in either
ease equal to the difference between it^ own speed and
that of the car.
ball were batted from rest. And it would be coming
straight toward him, for its motion relatively to the car
would be in the line uc; but as the ball is going forward
at the same time that it is moving sidewise toward the
car. its path relatively to the ground would be ab, just as
though it had gone to b" first with its original velocity and
direction, and then from //" to bj but the car has gone
ahead at the same time, so that it would hit it in the
same spot and with the same velocity and at the same
right angle as though both car and ball were standing
still when the ball was impelled in the direction ac.
At the end of the first half-second the ball, if moving
only in the direction ac, would have gone from a to c',
one-half of a to e, but in the same time, on account
of its movement in the direction parallel to the track,
would have gone from c' to V, so that at the end of the
half-second it would be found at b' ; and so for any sub-
Let the line ati. Fig. ".'. represent in length and direc-
tion the velocity and direction of the ball. Set off upon
it a distance cb representing to the same scale the velocity
of the car at any instant. Then ac, the difference of these
veloi ities, will be proportional to the speed of the ball rela-
tively to the car; that is, to the velocity with which it
would appear to the man in the car to be moving. Sup-
pose the velocity of the car to be increased to that repre-
sented by the line db; then to the man in the car the
ball would appear to be moving backward with a velocity
proportional to da.
Eeturning to Fig. 1, suppose something should give
the ball an impulse in the direction ac. with a velocity
proportional to the length of that line, the velocity of the
car and the previous velocity of the ball in the direction
mn being proportional to ab" = cb. To the man in the
ear the ball would appear to be coming straight toward
him, just as though the car were standing still and the
division of the time it would be found upon the line ab,
which is the path that it would follow relatively to the
ground.
[f we represent, then, by the line ab the velocity and
direction of the ball relatively to the ground, and by the
line cb the direction and velocity of the car, the line ac
joining their extremities will represent in length and di-
rection the velocity and direction with and in which the
ball approaches the car and with and from which it would
appear to the man in the car to be coming.
With the ball still moving in the line ab and with a
velocity proportional to the length of that line, suppose
the velocity of the car to be reduced to cb, Fig. :>. Then
the ball, although moving in the same direction and with
the same speed relatively to the ground as before, will
appear to the man in the car to be coming at him in the
direction ac. Fig. 3, and with a velocity proportional
to the length of that line.
Ma\ I. 1915
P 0 W E B
597
Applying this to the relative motion of steam in a tur-
bine, let ab, Fig. I. represent, by its direction and length,
the direction and velocity of a jet of -team issuing from
a nozzle. Let cb represent the direction and velocity
in and with which the blade moves. Then the jet would
approach the blade in the direction ac and impinge upon
it with a velocity proportional to (he length of that line.
If the blade were symmet rical, so as to turn the jet back
at the same angle, the jel would leave the blade in the
direction cd and— neglecting In— from friction, impact.
etc. — with the same velocity, cd = ac.
Suppose a ball t<i be fired from a gun placed at an angle
upon a car. as in Fig. ■">. 1 1* the car were standing still
Pig. 4 or (J is the typical diagram for a single-stage im-
pulse turbine. The initial velocity is 1', and the final
velocity, I',. The -mailer V2 in relation to Vx, the
greater the proportion of tin- energy of the jet which has
been absorbed by the turbine.
So long as the jet approaches the blade at an angle, as
at a. there will he some sidewise direction to the final
velocity 1",. As the angle a becomes less, the smaller may
F, become, as in Fig. 7, until the jet is in line with the
blade, Fig. 8, when the sidewise component disappears al-
together and the diagram becomes a straight line, as
shown in that figure. Its full length, ab — Vv represents
3>
►le
d1—
the ball would go off in the line cd relatively to the
ground, but if the ear 'were moving with a velocity which
was to that with which the hall is projected as <Ir is to cd,
the ball would, by reason of the velocity acquired as a
part of the car's contents, move forward a distance pro-
portional to de in the same time that it moved the dis-
tance cd in the direction of its projection. Instead of be-
ing at d, therefore, it would be at e, and the path that it
would have followed relatively to the ground would be ce.
In Fig. 1 we have a similar case. The steam is coming
out from the blade in the direction and with the velocity
cd, but it is traveling with the blade with the velocity
and in the direction cb = de. Set off de, equal in length
and parallel to cb, and the line ce will represent the direc-
tion and velocity of the steam when it leaves the blade with
respect to the ground or to the stationary nozzle.
1^^) Moving—*
>J>])J>J>M)r 'Moving — »
Moving
Siafionaru
Moving __>
the initial velocity; cb = a. the blade velocity, and ac =
i?e, the relative velocity and direction of entry, just as it
did in the preceding figure, only that the triangle has been
closed up and c lies upon the line ah.
If the jci at, say 1000 ft. per sec, and the
blade is running away from it at o00 ft. per sec the
598
P O W E R
Vol. 41, No. 18
jet will be overtaking the blade at the rate (that is ap-
proaching it with the relative velocity) of 1000 — 500,
or Re = V1 — u — ab — cb = 500 It. per sec. This
is Re, the relative velocity with which the jet enters the
blade. Neglecting friction, the jet is reversed in the
blade and thrown backward to the same velocity Rd rela-
tively to the blade: but. like the ball that was fired back-
ward from the car in Fig. 4. it must have its forward mo-
tion subtracted from its backward velocity to show its ve-
locity relatively to the ground. And when, from the
relative velocity of discharge Rd. Fig. 8, we subtract
the blade velocity a, by setting off upon the line dc =
Rd the line de = u, we have nothing left, indicating
that velocity and energy have all bean abstracted, that
the steam has been brought completely to rest.
.*-.
In order to do this for the abstract case the blade ve-
locity u must be one-half the initial absolute velocity 1",,
Fig. 7 ; for in order that the blade velocity u = de, Fig.
8, may equal and cancel the relative discharge velocity
Rd = cd, u must also equal Re, to which Rd is also
equal; and since ah equals Be + u, each of these quanti-
ties, if they are equal, must be one-half of ab.
Fig. 9 is the typical diagram for a sirgle stage of a re-
action turbine; cd = Rd represents the direction and ve-
locity with which the steam is discharged from the blade;
/; is the blade velocity, and V., the velocity relatively to the
ground, as in the other diagram. So long as the jet i> de-
livered at an angle there will be some residual velocity
72 in the jet. By reducing the angle and increasing
the blade speed, as shown in the dotted position, this resid-
ual velocity could be reduced from ec to .e'c, but it is
only when de becomes parallel with and equal in length to
dc that the residual velocity disappears altogether. The
blade of a reaction turbine must run at the same velocity
as the jet, in order to reduce its velocity to zero and ex-
tract all of its energy. If a car were paying out a cable
slower than the car was running, it would be dragging
the cable along the ground. If it were paying the cable
out faster than the car was running, it would be pushing
the cable backward. If the speed of the cable through
the opening in the car equaled the forward movement
of the car, the cable would be laid quietly upon the ground
with all the velocity and momentum which it possessed,
as a pari of the < ar's contents, taken out of it.
In Fig. 10 the triangle cdec has been moved from the
position which it occupies in Figs. 4 and 6 and attached
to the other triangle at a instead of at c, producing the
diagram which, as shown in the firmer lines, is frequent-
!. i 'i 'ii in turbine literature. The jet travels a distance
proportional to ab in a second, in the direction in which
it is discharged, but moves only a distance proportional
to fb in the direction db in which the blade is moving.
As/
%J/
y
Av
\ y
e
m
b
u
1
X— .
'
u
This line fb (the length of which is determined by
dropping upon it a perpendicular as af from the other ex-
tremity of the line to one extremity of which it is con-
nected ) represents the ••component" in the direction db
of the velocity represented by ab. This component of the
entering velocity is fb; the component of the discharge
velocity ae is ef, opposite in direction from fb. The blade,
therefore, has overcome, or annulled, the velocity fb and
has gotten up new velocity fe. In other words, it has re-
tarded the steam enough to destroy the velocity fb and
accelerated it enough to produce the velocity fe. But re-
tardation is only negative acceleration, and the effect is the
same as though the steam had been accelerated from rest
to a velocity proportional to be.
The force which must be exerted upon a body to pro-
duce a change in the velocity of its motion is equal to the
product of its mass and the acceleration produced.
The energy is equal to the product v'i the force and
the space through which it is exerted.
The energy produced by the flowing through the blades
of a given mas- of steam per second will be
Energy = mass X acceleration X blade speed
i/orce) ■ X (space)
May 4, 191
P 0 W E R
599
Tlie acceleration is be and the blade speed u, equal to
hh or e#, so that the area of the rectangle ebhge equals the
product of the acceleration and blade speed, and the en-
ergy absorbed by the blade equals mass X area ebhge; that
is, is directly proportional to that area.
The energy stored in a moving body is the product of
the mass and one-half the square of its velocity. The
energy in the entering- steam is proportional to mass
V-
X 9 > or to the area of the square upon the line ab
multiplied by one-hall' of the mass. The residual energy
in the escaping steam is mass X ~k~, or the area of the
2
square erected upon the line ae multiplied by one-half
78 72
the mass. The difference, mass X — — 5 — » represents
2
the difference in the energy of the steam as it enters and
leaves the blade. But, neglecting friction, etc., there is
no other place for the energy to go than to be absorbed by
the blade, and the difference ought to be equal to the en-
ergy which we found to be so absorbed; hence
y 2 yz
Mass X — - — 5 = mass X ebhge
Or, since the mass is common to both,
T2 — V?
ebhge = -1 — „ —
That is, the area ebhge equals one-half of the difference
between the areas of two squares on ab and ae, or the dif-
ference between the areas of the two squares is twice the
area ebhge* Notice also in passing, that the work done
is directly proportional to the line eb; that is, to the force
exerted in the direction of the blade movement.
The velocity-stage turbine abstracts a portion of the
residual energy V2 by passing the steam again through
the same or another set of blades. Suppose the size and
speed of the turbine were such that a blade velocity u
of 400 ft. per sec. could be obtained. Suppose, further,
that the conditions as to initial pressure, superheat and
vacuum were such that the steam would attain a velocity
of 4000 ft. per sec. if allowed to complete the expansion
in a single stage.
If the turbine were designed so that the steam would
acquire half this velocity in the first stage, there would
have to be three more such stages to complete the ex-
pansion; that is, if the work were to be equally divided
between the stages, or if in no stage was the velocity to
exceed 2000 ft. per sec, it would have to be a 4-stage tur-
bine. The energy in a moving body varies as the square
of the velocity. There is only one-quarter as much energy
in steam flowing at 2000 ft. per ^vr. as at twice that speed,
so that three similar stages with velocities of 2000 ft.
would have to be used to take out the other three-quarters.
The velocity dei reases inversely as the square root of
the number of stages — i/o the velocity for 4 stages, %
the velocity for 9 stages, etc.
Suppose, then, the steam is expanded in the first stage
through a range that will give it a velocity of 2000 ft.
per sec. The blade speed is 400 ft. per sec. and the
angle a of the nozzl( 20 deg., as shown in Fig. 11. It
•Vi" = (x + u)2 + y2 - x= + 2 xu + u2 + ya
W = (x — u)= + y- = x2 — 2 j:u + u- + y3
Subtracting the two equations
V,: — V..2 = 4 xu
v,-— v22
Hence — 2 xu = 2 x X u, which is the area ebhge,
2
for eb = dc = 2 x.
will be seen that there is considerable residual velocity
V.,. The only way to reduce this would be to reduce
the initial velocity I'',, which, as just shown, would re-
quire a number of stages varying as the square of the
number of times the velocity is reduced, or to increase
the blade speed u, which by the conditions of the case
is impossible.
The somewhat common impression that reducing the
blade speed and employing more stages produces better
economy is not borne out by this analysis. For the ab-
stract case the hydraulic efficiency depends upon the ratio
of the steam speed to the blade speed and would be the
same for one-half the blade speed if the steam speed were
also halved. The turbine built with the greater number
of stages would, however, bo the more efficient because of
the reduced surface friction, and because of the greater
area of blade passage due to the lower velocity. The
nozzles would occupy a greater number of degrees of the
wheel surface and the gain from reheating would be slight-
ly greater.
Fig. 11 shows diagrammatic-ally a Curtis turbine. The
high-pressure steam enters at A and expands in the noz-
zles BBB, impacting upon the moving blades CO, which
are carried upon the crown of the running wheel, as shown
at the left. Carried upon the casing is a set of stationary
blades I)D into which the steam is discharged with the
velocity and in the direction Ed (of the diagrams), and
in which the steam is turned around and discharged
upon the blades E, also attached to the moving wheel.
The blades E are deeper than the first ones C, not be-
cause the steam is supposed to expand in going through
them, but to allow the constant volume of steam to pass
at a decreased velocity. It comes off from the last row of
blades E at the same pressure as that with which it left
the nozzle B, but with its velocity very much reduced,
and passes to the second set of nozzles FFF to have its
velocity accelerated by another expansion.
If the blades were symmetrical the diagram for the ab-
stract case would be that shown by the heavy lines in Fig.
12. The velocity V2 with which the steam leaves the
blade O is the same with which it enters the stationary
blade 1) and with which it is discharged in the reverse
direction upon the blade E, but the angle of this line is no
longer 20 deg., and that of the relative entry Re (see
line BE, Fig. 12) approaches the bucket at much too
broad an angle. The buckets are, therefore, so fashioned
as to send the steam off at a sharper angle than that at
which they receive it. Notice that a line drawn across the
tips of a blade, as mn, Fig. 11, is not square with the
line of the blade's movement. This results in a diagram
more like that shown by the lighter lines in Fig. 12.
The final residual velocity V3 is reduced to that indi-
cated by the line EG. The initial energy is proportional
to the area of the square on Vv the energy of the steam
as it enters the second rotating blade by the middle square,
the difference being proportional to the energy taken out
in the first blade. The residual energy is proportional to
the smallest square and the energy taken out by the
second blade to the difference between the areas of this and
the middle square. The side of the second square is the
V2 and of the smallest square the Ys of the lighter dia-
gram. Unsymmetrical buckets on the moving wheel re-
sult in end thrust and must be used with discretion.
The reaction of a jet, or the force with which it pushes
the nozzle backward, is mass X velocity. The absolute ve-
GOO
POWER
"Vol. 41, No. 18
locity with which the jet leaves the blade is Rd in Fig. 13 ;
the component of this velocity in the direction of the blade
movement is x = u -f- m. The energy absorbed per sec-
ond is the product of this force by the space moved
through in a second, that is, by the blade velocity. It is.
therefore, proportional to mass X«X (w -f- m) = mass
X (u2 -f- urn). The energy due to the issuing velocity
is mass X ~a~ » that tu;e to the residual velocity mass X
a
-, and the difference mass X
(Z£_a).
Leaving off the mass, which is common to both, it
would seem that, as in the case of Fig. 10, the rectangle
ebhge = if -\- um, representing the energy absorbed,
ought to be equal to one-half the difference of the two
squares representing to the same scale the initial and final
energies. But the difference in the two squares is easily
proven to be u1 -\- 2 um.* Twice the rectangle would be
2 if -f- 2um. The difference in the squares is less than
twice the rectangle by just if; that is, by just the square
of the blade velocity. This is because there was in the
steam not only the energy due to the velocity with
which it issued from the jet, but the energy which it took
to get it into the blade and moving with the blade's ve-
locity. If a diagram similar to Fig. 10 be drawn with the
line ac = Re at right angles to the movement of the
blade, it will represent the action of a pure reaction tur-
bine, and the additional energy will be found in the
motion represented in the line ab of such diagram.
By J. C. Hawkins
Nearly every type of modern boiler furnace recom-
mended to assist in giving complete combustion and
to prevent smoke consists of firebrick piers, baffle walls.
etc., placed directly in the path of the gases to cause a
better mixture of the air and combustibles.
These gases are at a high temperature and impinge on
the baffles and piers, often causing the firebrick to melt
down quickly. The writer has seen bridge-walls in stand-
ard horizontal water-tube boiler settings, in which the
top of the wall was melted and had run down on the back
like huge icicles. The same trouble, only of a more seri-
ous nature, may occur in the arch of a dutch-oven fur-
nace. If the arch is wide it exerts considerable pressure
on the side walls and when the bricks become hot they
tend to crush, the wall settles and exerts a greater pres-
sure on the side walls. If the walls are not well stayed
they will be pushed out and much air may leak in where
it is not wanted.
The writer had considerable trouble of this kind in a
battery of two vertical water-tube boilers with dutch-oven
furnaces. The grate was 81 in. wide in each boiler and
each furnace had a single-span arch. Each time the arch
was renewed, which was about once a year, it pushed
the walls farther out, and it was necessary to put in addi-
tional tie-rods. The accompanying sketch shows how this
was accomplished. Four rods, 1*4 in. diameter each, were
used; one was set at the end of the arch and one just
inside the front wall. The lower rods were put in below
the grate and close to it so as to be out of the way and
not interfere with the pulling of the ashes. The top rods
were covered with firebrick and ashes to protect them from
the heat. The rods were made long enough to pass through
the two settings, with a long thread and nut on each end.
On account of close quarters the rods had to be linked in
the center to get them in place. Four pieces of old rail-
road rail, each about 6 ft. long, -were used as buckstays.
In addition to these rods a 5-in. railroad rail about 8 ft.
long was embedded in the center wall and also in the out-
side walls at the point where the arch rested, to strengthen
the wall at this point.
This arch was constructed of a special grade of furnace
brick and would last about a year, with hard firing. It
is not usually possible to patch this arch when the center
burns out, as it is generally sprung out of shape and
sagged in the center. It is left as long as it will stand.
y- + (u + m)2 = y= + u3 +
How the Furnace Arches Were Stayed
then torn out and a new one built. In the parts of the
lining where the brick is not subjected to the extreme heat
common firebrick will be found satisfactory and cheaper
than the high-grade brick used in the furnace. After the
bricks become glazed over, which protects them, they
should not be disturbed until it is necessary to repair
them.
Flualdl CMi&!|g=SwMFace
To overcome the necessity of heating Cling-Surface
belt dressing without impairing its efficiency has long
been the aim of the Cling-Surface Co., Buffalo, N. Y.
This has been accomplished, and the dressing has been
i 'inverted to a semifluid ready for use at any temperature
above 60 deg. F. In other words, no heating is required
during eight to ten months of the year, nor in the winter
if it is kept in a warm room. Where it is kept in a
cold loom or exposed to winter temperature, it need not
lie heated above 100 deg. F., and then only for a few
minutes for softening.
D. S. Coal Production in 1914 — According- to Edward W.
Parker, statistician of the United States Geological Survey,
the total coal production of the United States in 1914 was
about 510,000,000 short tons, a decrease of about 60,000.000
tons compared with the record output of 1!U3. Practically
all of this decrease '>>as in the output of the bituminous
mines. The production of Pennsylvania anthracite in 1914
was not materially different from that of the preceding year,
which was S1,71S,6S0 Ions tons. In l'.Ul, however, about
1,000,000 tons (principally nut and steam sizes) went into
storage, so that the quantity sent to market was about
1,000,000 tons less than in 1913. The principal decreases in
the production of bituminous coal were in the coking districts.
It is estimated that in Pennsylvania alone the production of
bituminous coal decreased between 20,000,000 and 25, 000.000
tons, and that the larger part of this decrease was in Fayette
and Westmoreland counties, which constitute the Connells-
ville and Lower Connellsville coking districts.
.May 1, L915
1M)\V E i;
601
Imifteoor Wiiraimg' for OglhitLimij
kim<
By A. L. Cook4
8TN0PSIS — The first of a series of articles cov-
ering the methods employed in making plans of
lighting and power systems for industrial estab-
lishments and office buildings! and in calculat-
ing the sizes of wires required for such service.
The treatment is such as to meet the requirements
of superintendents or engineers in charge of such
buildings, who may be called upon to make addi-
tions to or changes in the equipment; and no at-
tempt has i" < a made to cover problems which
should be handled by the illuminating engineer or
a power specialist. The first installment covers the
voltages and systems employed, the National Elec-
tric Code Hubs, llir types, number and spacing of
lamps and the determination of the lighting load.
The usual voltages employed for lighting are about
120 or 240 with a two-wire system and 120 for each side
with a three-wire system. Either direct or alternating
current may be used. Occasionally, three-phase or two-
phase alternating current is employed for lighting, be-
cause of peculiarities in the conditions of supply. For
alternating-current lighting GO cycles is generally used,
since 25 cycles is not as satisfactory owing to a flickering
of the lights in some cases. It has been found, however,
that tungsten lamps having a rating of 60 watts or more
can be employed satisfactorily on 25 cycles. With ordi-
nary inclosed arc lamps, 25 cycles is not satisfactory, al-
though flame-carbon arc lamps can be used on this fre-
quency. For direct-current motors, the standard voltages
are 115, 230 or 550, and for alternating-current motors,
110, 220, 440 and 550 volts are commonly employed, al-
though in some cases for very large motors, 2200 volts is
used. The frequency may be either 60 or 25 cycles, and
occasionally 40.
The voltages given for lighting and power service are
the values at the lamps or motors. The standard genera-
tor voltages for direct current are 125, 250 and 600, and
for alternating current, 120, 240, 480 and 600, which al-
lows a reasonable drop between the generator and the load.
In some cases a multivoltage system is used for motors, in
order to give a ready means of varying the speed. This
is not generally necessary, however, since modern direct-
current motors permit wide -peed variation by a change
in the held strength.
The choice of a particular system for lighting or power
service is affected by a number of fa. -tor-, such as the
character of the existing system or the central-station
source of supply, and the relative sizes of the power and
lighting loads. When an extension is to be made to an
existing installation, the same system must be used for
the extension, unless the addition is so large or the re-
quirements differ so widely that a change in the system or
the addition of a different kind of supply can be seriously
considered. For a new plant moTe freedom of choice ex-
ists, and the relative merits of the various systems will
therefon I asidered.
Direct vs. Alternating Current
For lighting, either alternating or direct current would,
in general, be satisfactory, ami the advantage of easy
change of voltage in the case of the former makes it pref-
erable in supplying buildings covering large areas. Bow-
ever, the lighting load is usually small, compared with
the power load; hence the choice is fixed by the power re-
quirements. The important advantages and disadvan-
tage's of alternating and direct current for power supply
may lie summarized a- follows:
DIRECT CURRENT ALTERNATING CURRENT
It is not generally feasible The voltage can be easily
to use more than 240 volts for transformed, using voltages
lighting. Therefore this limits suitable for lights and motors,
the voltage of the system if
supplied from the same gen-
erator as the motors.
2. Maintenance is higher,
ring to commutators.
3. Wide speed
motor by simple
high efficiency.
2. There is no commutator:
hence the motor is more
rugged. It will stand larger
momentary overloads, there is
no danger of Are from sparks
at the commutator and it is
more reliable.
iriation of 3. Speed variation is difficult
leans, with and the motor is less efficient
at reduced speeds.
*Head of Departrr
tute. Brooklyn, N. Y.
it of Applied Electricity, Pratt Insti-
4. Motors have better start- 4. Operation is not satisfac-
ing characteristics for cranes tory on high-speed elevators
and elevators. and large cranes. Starting
current is greater.
5. Starting current is lower 5. Starting current for or-
for usual types of constant- dinary type is large. Special
speed motors. arrangements are necessary
to reduce it.
6. A somewhat larger gen-
erator is required for a given
motor load.
The relative sizes of the power and lighting loads will
have an important bearing upon the selection of the sys-
tem. In some cases of light manufacturing, particularly
if all the work is in one building, where the feeders would
lie short, direct current might well be used, employing
120 volts two-wire for small systems, and 2 10 volts three-
wire, or possibly two-wire, for larger systems. If a two-
wire system be used, the feeders would be about one-fourth
as large for the 240 volts as for 120 volts; but, on the
other hand, the lighting would have to be supplied at 240,
which would entail somewhat greater cost for lamps ami
maintenance. It is better to operate the motors at ".'10
volts and supply the lights on a 120-240-volt three-wire
Bystem. By this means, the saving in size of feeders is
nearly as great as if the entire load were supplied at 240
volts and the advantage of the lower-voltage lamps is se-
cured. The additional power-house equipment is of small
cost.
For most industrial uses, the alternating-current motor
is satisfactory, and in some cases almost necessary, either
because of the great distances from the power house or the
602
POW E 8
Vol. 41 , No. 18
severe operating conditions due to dust, moisture, etc.
Its principal disadvantage is the difficulty in adjusting
tli.- speed. With a direet-cnrrent system it is possible to
obtain motors which will allow a speed change of three to
one. When the speed is adjusted to a given value be-
tween these limits, it will remain practically constant re-
gardless of the load. Such motors are extensively used
for driving lathes and .similar machine tools. It is pos-
sible to provide means by which the speed of an alternat-
ing-current motor ran In- adjusted to as wide a range as the
direct-current motor, but usually at a sacrifice in effi-
ciency; whereas, the direct-current motor has nearly the
same efficiency at all speeds. Moreover, the variable-speed
alternating-eurrent motor, having been adjusted to a par-
ticular speed, will not maintain this as the load changes;
instead, the speed will increase as the load decreases. This
wide speed variation is objectionable where constant speed
with varying load is necessary, as in machine-tool driving :
but for some purposes, such as ventilating fans, centrifu-
gal pumps, paper machines, and the like, where the load
does not vary suddenly, the use of an alternating-current
adjustable-speed motor is satisfactory. Alternating-cur-
rent motors are not a- satisfactory for cranes and elevators,
owing principally to the difficulty of control, particularly
when making stops. For this reason direct-current mo-
tors are to be preferred for high-speed elevators and large
cranes. Therefore, in an office building where the eleva-
tor load is usually greater than the other motor load and
the length of the feeders i- not great, the direct-current
system is preferable. For large buildings the three-wire.
240-volt system should lie used, the motors operating at
240 volts and the lights at 120. Only in small building-
should the 120-volt two-wire system be used.
If the building is not supplied from a power plant on
the premises, hut obtains its supply from a central station,
the type of service will depend upon the system of the
supply company. If only alternating current is available
it will he best to use alternating-current elevators unless
the speed is high (above 300 it. per min.) rather than pro-
vide the necessary transforming apparatus. For indus-
trial establishments in general, the alternating current
is to be preferred unless the cranes and variable-speed
tools form a large proportion of the total load. If it is
absolutely necessary to use direct current for some of the
motors, it is better to provide alternating-current service
for general uses, with a direct-current supply for cranes
and special work.
When installing any wiring it is desirable to conform
in all respects to the local rules governing such installa-
tions. The rules of the National Board of Fire Under-
writers, called the "National Electric Code.'' form the
basis of most of the regulations which have been issued by
various cities and other parties interested, and must be fol-
lowed in order to obtain lire insurance on property. These
rule~ may he obtained gratis from the National Board of
Fire Underwriters by applying to it- New York. Boston
or Chicago offices. The Inspection Department of the
Associated Factory Mutual Fire Insurance Companies,
with an office in Boston, has issued the "National Electric
Code'" with explanatory notes, thus giving in many cases
more specific directions for the proper installation of elec-
trical apparatus than is contained in the "Code." In many
cases there are rules issued bj the city inspection depart-
ments, which are substantially the same as the "National
Electric Code," hut care should lie taken to see that the
work not only meets the code requirements hut also con-
forms to the local rules. In the following discussion the
rules of the "National Electric Code" are followed.
Choice ami Distribution or Lamps
The -abject of the proper illumination of industrial
establishments has in the past few years been given con-
siderable attention on the part of factory superintendents
and managers, who have begun to realize that it pays to
pro\ ide sufficient illumination. Investigations have shown
that an efficient lighting system increases the output from
2 to 10 per cent., and it has also been found that the num-
ber of accidents is materially reduced when adequate light-
ing is provided.
For interior illumination of buildings, there are avail-
able the following types of lamps:
Lamp Service
1. Carbon-filament A.C. or D.C.
2. Gem- or metallized-filament A.C. or D.C.
3. Tantalum A.C. or D.C.
4. Tungsten, including "nitrogen" filled lamps A.C. or D.C.
•". Inclosed-carbon arc A.C. or D.C.
6. Metallic-flame or magnetite arc D.C.
7. Flame-carbon arc A.C or D C
8. Nt-rnst A.C. or D.C.
9. Cooper-Hewitt mercury arc A.C. or D.C.
While all of the foregoing types have been used for in-
terior illumination, the practice lias now become so stand-
ardized as to make the tungsten lamp by far the most com-
mon for ordinary heights of ceilings. The metallic-dame
arc and flame-carbon arc are used for lighting large floor
areas with high ceilings, particularly where there is more
or less smoke and gas. The so-called nitrogen-filled lamp,
which is a special form of tungsten lamp with the bulb
filled with nitrogen or a similar gas. is very useful where
large lighting units can he employed, and the tendency is
to use this in place of the metallic-flame or flame-carbon
arc, owing to the reduced cost of maintenance. The mer-
cury arc has also been used extensively, principally because
of its small power consumption, but it produces such an
objectionable color that it is unsuitable for many uses and
can better hi' replaced by the nitrogen-tilled lamp. This
gives a light even whiter than the ordinary tungsten lamp
with a power consumption not much greater than that of
the mercury arc. Present practice, therefore, for rooms
of ordinary height, has narrowed down to the use of tung-
sten lamps with glass or steel reflectors, mounted near the
ceiling and arranged to give sufficient illumination to the
entire room. In general, drop cords with individual lights
have been eliminated as far as possible and are used only
for special work which cannot be lighted from the over-
head lamps. Where it is necessary to use individual lights,
a 16-ep. carbon-filament or a 40-watt gem lamp is used.
The latter is preferable as it gives the same candlepower
as the carbon and requires about 20 per cent, less power.
Table 1 gives data on the various sizes of tungsten lamps.
TABLE 1— DATA ON TUNGSTEN LAMPS*
Size. Watts per Approximate Current,
Rated Candle- Candle- Life, Amperes
Watts power power Hours 120 Volts 240 Volts
25 24 1.05 1000 0 21 0.11
40 39 1.03 1000 0.33 0.17
GO 00 1.00 1000 0.50 0.2T.
100 105 0 »:< 1000 0.83 n 12
l.r,0 107 0.90 1000 1.25 0 62
250 27S 0.90 1000 2. OS 1.04
400 445 0.90 1000 3.33 1.67
500 ■ 0.90 1000 4.16 2.08
1200 222 0.90 1000 1.67
t300 353 0.85 1000 2.50
t400 534 0.75 1000 3.33
i.Miil 714 0.70 1000 4.10
t750 1150 0.65 1000 6 25
tlOOO 1005 0.60 1000
•From figures supplied by the National Lamp Works of
the General Electric Co. The above applies to 120-volt lamps;
for 240-volt lamps the watts per candlepower are about 10
per cent, higher.
T.Vitrogen -filled lamps of 120 volts only.
May 4, 1915
P 0 \Y E R
603
Sizes smaller than 25 watts are manufactured, but are not
suitable for industrial Lighting. For multiple inclosed-
flame arcs the following values are typical:
Dil
Voltage
Watts
Amperes »-a
Power factor • • ■
Candlepower ' '"'
Watts per candlepower u.41
ct Current
110
715
0.62
1600
0.32
Iu the case of the arc lamp, the candlepower refers to
the average for the lower hemisphere of the lamp. For
the tungsten lamps the candlepower and efficiency values
are based on average candlepower in a horizontal direc-
tion when the lamp is vertical, no reflectors or shades be-
ing used.
It is not the intention to go into the details involved
in the determination of the proper number and spacing
of lamps for all classes of service, as this is a task for the
illuminating engineer. Careful calculations of such a
problem require considerable experience and a knowledge
of the effect of reflection from walls and ceilings. It is
frequently necessary, however, to make a rough estimate of
the amount of power required for lighting, in order to pro-
vide the necessary feeder and generator capacity. There
are a few simple rules that ran be applied in such cases,
which will give satisfactory results under usual condi-
tions.
It is first necessary to determine the amount of power
required for a given floor area. This will depend, of
course, upon the amount of light necessary, which will
vary with the character of the work carried on. Table 2
gives the number of watts required per square foot of floor
area For different classes of work, with various arrange-
ments of tungsten lamps. These values are based on good
practice and will give first-class illumination under aver-
age conditions. The principal item which would affect
these values is the color of the ceilings and walls. For
-, stores, corridors and drafting rooms it is assumed
that both the ceilings and the walls are fairly light in
color, while for factories, warehouses and power houses
they would be darker and less light would be reflected.
The figures given for general office illumination are suffi-
cient for usual office work, while those for special illum-
ination should be used where bookkeeping or work of a
similar nature is carried on. The amount of power al-
lowed for a drafting room -is sufficient to provide suitable
illumination without the use of individual lamps. For
rooms where rough manufacturing is carried on and
where close application to the work is not required, the
figures for general factory illumination should be suffi-
cient; for fine machine work, toolmaking and bench
work, those for special factory illumination should be
used. The lamps should be provided with suitable re-
flectors, in order to direct as much of the light as possible
on the work. There is a great variety of these reflectors,
but they can all be groi ped in a few general classes, each
of which is best adapted for particular conditions. There
are on the market several types of glass reflectors which
direct most of the light in a downward direction, but
allow a certain amount to pass through to the ceiling.
The best example of this type is the prismatic "Holo-
phane." In order to have a good distribution of light,
it is necessary to employ the proper style of reflector;
hence a different size is manufactured for each size of
tungsten lamp. It is necessary also to use the right type
of shade holder in order that the lamp may be correctly
located in the reflector.
Since modern systems of illumination are usually laid
out to give practically uniform lighting over the entire
floor area, it is necessary to use different types of reflec-
tors for different heights of ceilings and spacings between
lamps. The Holophane prismatic glass reflectors are made
in three styles: "Extensive," for low ceilings; "inten-
sive,"' for medium ceilings; and -focusing," for high
ceilings. Glass reflectors are best adapted for offices,
stores, drafting rooms and similar places, where it is de-
sirable to light the walls and ceilings, as well as the
work. They have also been used quite extensively for fac-
tory lighting, but are not suitable for use where there is
danger of breakage.
Steel reflectors are made in a number of styles, with
white porcelain-enamel surfaces, white painted surfaces,
or aluminum painted surfaces. In general, the porcelain-
enameled reflector is better than the others, owing to a
great reflecting power, and the ease with which it can
"ig. 1. Bowl Type
Dome Type
be kept clean. There are two general types of steel reflec-
tors— the bowl, shown in Fig. 1-a, and the dome, in Fig.
1-/). These reflectors are made in various sizes to suit
particular tungsten lamps, and in various shapes for dif-
ferent heights of ceiling. The dome type (b) should be
TABLE 2— POWER REQUIRED FOR ILLUMINATION.
TUNGSTEN LAMPS'
Watts per Square Foot
Direct Indirect
Class of Work A B
Office— general 100 H2,
Office— special £■-» -•«"
Drafting room £»« *•£"
Corridors and halls 0.50
Factories — general
Factories — special
Warehouses ....
Stores
Power house
0.80
1.50
0.50
1 25 2.00
0.80
Storage °-30
•If nitrogen-filled lamps are used, multiply the watts per
square foot as given above by 0.75.
used generally ; the bowl type (a), which incloses the lamp
more than the dome, being used only when the lamps are
mounted so low that they would be in the line of sight of
the workmen. When steel reflectors are used, the ceilings
are not illuminated, except by a small amount due to re-
II • ti,,n from the benches or tables; but for many indus-
trial applications thi is not objectionable. In offices the
steel reflector- d i not give a pleasing effect. Values for
cither glass or steel reflectors are given in column A of
Table 2, since they are both classed as direct illuminants.
For the same character of walls and ceilings there would
be only a slight difference in the amount of illumination
produced by the two types.
In some cases, particularly in drafting rooms, the indi-
rect system of lighting is preferable. With this the light is
directed upon the ceiling and is then reflected onto the
work. It results in lower efficiency, but in many cases
is justified, in order to eliminate troublesome shadows.
A modification of this system involves the use of reflectors,
604
P 0 W E E
Vol. 41, No. 18
which allow a small portion of the light to be directed
downward, giving what is called a semi-indirect system. A
satisfactory arrangement with this system is to employ
glass reflectors mounted on suitable fixtures and pointed
toward the ceiling, instead of downward, as is usual. The
indirect system depends for its efficiency upon light-col-
ored ceilings and walls, and therefore is better adapted
for use in offices, stores and drafting rooms than in fac-
tories.
The allowable watts per square foot for a given class
of work can be found from Table 2, and when multiplied
by the floor area, will give the total power required. It
may seem to some that the height of the lamp above the
work would have a decided effect upon the amount of
power required, but this is not the case provided a suit-
able reflector and proper spacing of the lamps are em-
ployed. There is, however, a considerable difference in
lighting depending upon the number of units employed
and the color of the walls and ceiling.
As an example, the figures of Table 2 will be applied to
the lighting of four floors of a factory building having
a width of 46 ft. and a length of 135 ft., divided into
nine bays 15 ft. wide, with a line of columns down the
center of the building. Table 3 gives a tabulation show-
ing the lighting to be provided for each floor.
TABLE 3— EXAMPLE OF LIGHTING CALCULATION
Floor
Character
of Work
Ceiling
Height,
Feet
s
Area.
Sq.Ft
6210
6210
6210
6210
Assumed
Watts
per
Sq.Ft.
0.30
1.50
1.50
0.50
Size
of
Unit
60
100
100
100
Actual
Watts
per
Sq.Ft.
0.35
First floor — Machine shop 14
Second floor — Assembly... 12
Third floor— Stock room.. 12
1.74
1.74
0.58
This building would employ direct lighting by means of
tungsten lamps, and steel or glass reflectors. From the
1
a | a
a
a
a i a
a
a
a ! a
n
a
Correct Incorrect
Fig. ".'. Spai im. op Ceiling Outlets
given floor areas and the allowable watts per square foot,
the approximate amount of power can be estimated. This
would be sufficient for an estimate of the total load re-
quired for the lighting, but in general it is best to choose
the size of units and determine the number to be employed,
since the spacing which must be used often modifies the
total load.
The spacing and size of unit to be used are affected by
the height of ceiling as well as by the arrangement of
the beams or girders. There is a certain relation between
the height of the lamps and their size, which must be ad-
hered to as closely as possible, in order to get uniform
illumination without objectionable shadows. For low ceil-
ings the units should be small and closely spaced, while
for high ceilings large units, more widely spaced, should
be used. Table 4 will serve as a guide to the selection
of the proper size of unit. This should lie used in con-
nection with Table 5, which gives the approximate spac-
ing of lamps of different sizes.
The units should be mounted at least 8 ft. from the floor
and more if possible ; a height of 10 ft. being satisfactory
for rooms with ceilings 11 to 16 ft. high. For higher
ceilings, cranes and other obstructions usually fix the
height of mounting. If deep girders divide the ceiling
TABLE 4 — SIZES OF LIGHTING UNITS FOR VARIOUS
MOUNTING HEIGHTS
Height of Unit above Floor Size of Unit, Watts
Up to 9 ft 40 or 60
9 to 11 ft 60 or 100
11 to 16 ft 100 or 150
16 to 20 ft 150 or 250
20 ft. and abo\c 250, 400, 500 and nitrogen-filled
lamps or flame arcs
TABLE 5— APPROXIMATE SPACING DISTANCES FOR
LIGHTING UNITS
Watts Watts
Size of per Size of per
Units, Sq.Ft., Spacing Units, Sq.Ft., Spacing
"Watts Direct* Distance Watts Direct* Distance
40 0.3 11 ft. 6 in. 150 1.5 10 ft.
40 0.5 9 ft. 150 2.0 Sft. 8 in.
40 0.S 7 ft
250 0.3 29 ft.
60 0.3 14 ft. 2 in. 250 0.5 22 ft. 5 in.
60 0.5 lift. 250 0.8 17 ft. 8 in.
60 0.S 8 ft. Sin. 250 1.0 15 ft. 10 in.
60 1.0 7 ft. 9 in. 250 1.25 14 ft. 1 in.
60 1.25 7 ft. 250 1.5 12 ft. 11 in.
60 1.5 6 ft. 4 in. 250 2.0 11 ft. 2 in.
100 0.5 14 ft. 400 0.8 22 ft. 5 in.
100 0.8 lift. 2 in. 400 1.0 20 ft.
100 1.0 10 ft. 400 1.25 17 ft. 11 in.
100 1.25 9 ft. 400 1.50 16 ft. 4 in.
100 1.5 Sft. 2 in. 400 2.0 14ft. 1 in.
100 2.0 7 ft.
500 0.S 25 ft.
150 0.5 17 ft. 4 in. 500 1.0 22ft. Sin.
150 0.S 13 ft. S in. 500 1.25 20 ft.
150 1.0 12 ft. 3 in. 500 1.50 IS ft. 3 in.
150 1.25 lift. 500 2.0 15 ft. 10 in.
•The figures given apply to ordinary tungst lamps. In
general the spacing of lamps should be about 50 per cent,
greater than their height above the work illuminated.
into bays, the lamps should be located slightly below the
bottom edge of the girders if possible. Having fixed upon
a suitable mounting height, a size of unit should lie chosen
by reference to Table 4. The rating of this unit divided
into the total watts for the given floor area will give the
required number of lights. This number should then be
laid out upon a plan of the room and the spacing checked
with the average values given in Table 5. The lamps
should be located without reference to the individual
machines, so that a change in the latter would not affect
the system. Each light should, if possible, be located in
the center of a square, the length of the side being the
spacing distance assumed. The lamps should be arranged
in parallel rows, the distance between rows each way be-
ing as nearly as possible equal to the given spacing dis-
tance. The distance from the wall to the first row should
be about one-half the spacing distance, except where
benches are located at the side walls, when the first row of
lights should be located about 13 to 18 in. nearer the wall
than the edge of the bench. If the room is divided into
bays by deep girders or columns, each bay should be
treated as far as possible as a unit, and the lights so spaced
as to avoid shadows from the columns. If the size of
lamp first selected does not give a suitable number for
convenient location, a different size should be chosen and
another arrangement tried. It is, of course, desirable to
use as large a unit as possible, to reduce the cost of the
wiring: on the other hand, a smaller unit gives more uni-
form distribution of the light, greater freedom from
shadows, and less trouble due to one light being extin-
guished. With a smaller unit it is also possible to arrange
a more flexible method of control, allowing some ol the
lamps to be extinguished during a part of the time, and
resulting in a saving in power.
In the example selected, the basement requires about 0.3
May 1, 1915
l' O W E i;
605
11 ft. 6 in., the two rows next the walls being 5
watt per square foot. From Table I either 10- or 60-watl
lamps could be used. From Table 5 it, will be seen (bat.
ID-watt lamps, to give 0.3 watt per square foot, must be
spaced on 11-ft. 6-in. centers. This does not work in
well, since the bays are 15 ft. wide. If 60-watt lamps
are selected the spacing could be 14 ft. 2 in., which would
allow one lamp in each row per bay. Allowing four rows —
two either side of tbe line of columns — gives a total of 36
Ol en
lamps or 3G X 60 = 2160 watts, which gives - — —
0.35 watt per square foot. Tbe spacing of the rows would
,46
T.
ft. 9 in. from the wall.
For tbe first floor about 1.5 watts per square foot will
be required. From Table 5 it will be seen that a 100-
watt unit would give a spacing of 8 ft. 2 in., and from
.Table 4 that this size is suitable for the height of ceiling.
Therefore, two units per bay can be allowed, giving a
spacing of 7 ft. 6 in. With six rows there would be a
total of 108 units, requiring 10,800 watts. This is
equivalent to 1.74 watts per square foot, which is some-
what more than was assumed. If the same number of 60-
watt units were selected, a total of 6480 watts would be
required, or 1.04 watts per square foot. Because of the
columns through tbe center seven rows could not be used
and with eight rows the spacing would be too small and
the cost of installation too great. The distance between
the wall and the first row would ordinarily be one-half
the distance between the other rows ; but in this case,
as there would be benches along the walls, the rows next
the walls could be located 2 ft. away and the other rows
spaced evenly, giving about 8 ft. 5 in. for the distance
between these rows. The other floors would be treated
similarly. If there are no beams to divide the room into
bays, the problem is simplified, but it must be remem-
bered that the lamps should be located in the center of
the square or rectangle and not at the corners ; see Fig. 2.
Vaxiaiflinm Me^&Biagl Systems
By W. L. Dukand
The use of vacuum heating systems has increased to
such a large extent in the last few years that a general
description of this method of heating may be of interest
to engineers who are not familiar with it.
The advantages of a vacuum system over a gravity
system may be summarized as better circulation, the use
of smaller pipes and the absence of air valves. In build-
ings with steam power plants, when the exhaust steam is
in excess of the requirements for beating, a vacuum
heating system is a distinct factor for economy, since
the back pressure on tbe engines can be reduced to
atmospheric, thereby correspondingly decreasing the water
rate of the engines, and for v rv high buildings, buildings
with large floor areas, or a group of buildings, a vacuum
system is practically the only type of steam heating system
that will work satisfactorily.
One of the claims set, forth by the manufacturers of
vacuum valves is that wide variation in temperature is
permissible. This is, however, more a talking point than
anything else, as in tbe best-designed systems the pressure
in the radiators is rarely lower than 2 in. of vacuum or
more than two pounds above atmosphere, or a range of
only about 10 deg.
There are three types of vacuum return valves on tbe
market — the float, the thermostatic and the differential.
The iloat type acts on the principle of a bucket trap, the
condensed water raising a float which opens an outlet
that allows the water to run out- until just enough is left
to maintain a seal, when the outlet is closed. A very
small opening is left for the air to escape. This type of
valve has the disadvantage that the opening for the escape
of air allows steam to leak into the return lines, keeping
the temperature of the returns so high that it is necessary
to use an injection of cold water at the pump to maintain
the desired vacuum.
In almost every case the manufacturers of the float
type of valve have gone over to the thermostatic type. In
this a hollow metal disk, usually made of copper, is filled
with one or more liquids that vaporize at or around 200
deg. The action of this valve is extremely simple. Any
air or condensed steam of a lower temperature than the
valve is set for passes through the outlet, but as soon
as steam reaches the disk tbe expansion of the liquid inside
shuts the valve off. The advantage of this over the float,
type is that it is noiseless and does not pass steam, thus
doing away with the use of jet water at the vacuum pump.
Thermostatic valves may be divided into two classes —
one in which the expansion disk is on the pressure side
of the valve and the other in which the disk is on the
vacuum side. In most eases either kind of valve works
satisfactorily, but experiments have shown that those
with the disk on the pressure side can carry about 20 in.
of vacuum, as against 10 in. for the other kind.
The third type of vacuum return valves is used on
what is known as th differentia] system. In this a
weighted check valve with restricted orifice is placed on
the return side of each radiator. These valves are
placed at different points, usually at tbe bottom of each
return riser on the end of a horizontal run. The valve
disk is weighted with a number of lead disks, the size
of Opening and weight of disks being so proportioned that
for each lead disk a difference of pressure of 1 in. of
mercury is required to lift the valve. By varying the
number of disks any vacuum from 2 in. or 3 in. to 15 in.
can be carried, as may be desired. This is the only type
of valve by which the vacuum carried can be so varied,
a feature which is advantageous for systems spread out
over large areas or which have long horizontal runs.
In its installation a vacuum system is no different from
a gravity system except that smaller pipes can be used,
especially for the returns, and the vacuum valves are
placed on the radiators and no air valves are used. The
main return line is carried through a strainer to the
vacuum pump, which can be either steam or electric
driven, and from there it is pumped to a small tank with
a vent open to the atmosphere. This relieves the tank
of entrained air, and the return water is either fed direct
to the boiler or through a feed-water heater.
It is not advisable to cover the returns in a vacuum
system, as the exposed pipe surfaces allow the water to
become sufficiently cooled for operation of the vacuum
pump without the use of jet water. Where vacuum return
valves are used dirt pockets should be provided, and in
starting a new system the interiors of the valves should be
removed and the system should be operated for four or
five weeks as a gravity system.
606
P 0 W E E
Vol. 41, No. 18
Tlbe F©^@rs©Ea Power Plaint OH
This filter, which is manufactured by the Richardson-
Phenix Co.. Milwaukee, Wis., embodies new principles
of oil purification. Its operation is as follows :
The dirty oil enters through the strainer box at the
top and passes down through the removable strainer,
where large particles of foreign matter, such as waste
and the like, are strained out : the oil then goes to the
heating tray where its viscosity is reduced. It then
flows to the compartment below the heating coils and
down through the funnel. The further operation of the
precipitation compartment is more clearly shown in
Fig. 2.
Passing down through the tube conductor, the oil
is spread out by a baffle under the lower tray. Under
the action of the greater head which builds up in the
water. As oil is lighter than water, the top of the over-
flow is a little lower than the level of oil in the precipi-
tation compartment. As more water is precipitated out
of the oil, the water level in the precipitation compart-
ment tends to rise and the leg of the U-tube, which is
inside the filter, becomes heavier because it is made up
of a greater proportion of water and less of oil, thus
water flows over the top of the funnel until the two
legs of the U-tube again balance. In this way a low-
water level is automatically maintained in the precipi-
tation compartment.
Referring to Fig. 1. the level of the oil in the top
tray is maintained constant by the skimmer, and the oil
then flows through a pipe into the filtering compartment.
which contains nine noncollapsible filtering units, sttch
as is shown in Fig. 3. The oil passes from the outside
to the inside of the filtering units, then out through
the nozzles which project through the wall of the filter-
Fig. 1.
Showing Interior Construction
of the Filter
Fin. 'J. Section through
"Water-Separating
Chamber
£
Fig. 3.
xoncollapsible filtering
Unit
tube conductor, the oil is forced to take a zigzag path
upward, passing under and over several trays, as shown
by the lines of flow. It then passes out through the
opening below the heating tray to the filtering compart-
ment. The separated water collects in the bottoms of
the different trays and is bypassed to the bottom of the
precipitation compartment by means of funnels that sur-
round the tube conductor, and does not again come in
contact with the traveling oil.
The water which is removed by the precipitation process
is automatically ejected by an overflow tube at the
right, which consists of two concentric pipes. The water
flows upward through the outer tube and spills over the
top of the funnel. The lower end of the tube can be con-
nected to a sump or sewer. The funnel is threaded and
can be raised or lowered, providing for proper adjust-
ment for oils of different specific gravities. This water
overflow simply operates on the U-tube principle; that
is, the column of water in the outer pipe balances a
column in the filter made up partly of oil and partly of
ing compartment, to the clean-oil compartment. The
nozzles on each unit lit into a spring-actuated valve so
that any individual unit can be withdrawn and cleaned
without interfering with the continuous operation of
the filter. When the unit is withdrawn, this valve
closes and prevents unfiltered oil from flowing into the
clean-oil compartment. The filtering cloth is so ar-
ranged that it is free from folds or plaits, thus rendering
every square inch active in filtering.
No oil can pass to the clean-oil compartment until
the level in the filtering compartment reaches the outlets.
Thus no filtering takes place until every square inch of
cloth is submerged in oil ; then as soon as a slight head
builds up over the outlet, the process of filtration begins
and is distributed over all of the surface, which is
subjected to equal pressure.
The head of oil over the filtering disks is shown by
an indicator at the top of the gage. When the filter is
being operated at normal rating this gage should show a
level of about three inches. If a greater height is in-
May 4, 1915
row B E
eor
dicated it shows that the nil is not passing through the
cloth as last as it should and that the cloths need clean-
ing. The filters arc rated at 3-in. nead over the filtering
di-ks, but space is provided for carrying a 6-in. head.
Thus the apparatus is capable of handling short over-
loads of 100 per rent., so that in case a large batch of
oil should he run in. the filter will he able to take care
of it.
The advantage in arranging the filtering cloth in a
vertical position and having the oil pass from the outside
to the inside of the unit,- is that the slime and sediment
which collect mi the cloth continually work toward the
bottom and drop oil', thus automatically tending to keep
the surface clean. The filtering medium is a special
grade of cloth that docs not act as a screen, hut actually
filters the oil largely by capillary action.
The water level in the precipitation compartment
should be carried as low as practical. The gage shows
the clean-oil level. The cock on the fitting at the bot-
tom of this gage provides for withdrawal of clean nil to
use in cans for hand oiling. The right-hand gage shows
the level of the oil in the filtering compartment. This
should at all times be full of oil.
All of the level gages have sheet-metal guards in hack
of them which are white enamel on the inside. This
makes it easy to see at a distance the oil level and also
protects the glass from breakage.
A thermometer shows the temperature of the oil be-
fore it enters the precipitation compartment, thus enab-
ling the engineer to adjust the quantity of heat supplied
so that the proper viscosity will lie maintained. An-
other thermometer shows the temperature of the oil in
the clean-nil storage compart m int.
The filter body is constructed of galvanized sheet steel
reinforced with channel ami angle iron. All joints are
lapped and closely riveted and soldered.
The only parts needing periodical cleaning are the
filter cloths. The filtering units can I asily removed
without interfering with the continuous operation of the
filter ami should he lifted out and set in a pan of kero-
sene or gasoline and brushed down with a stiff brush;
this is possible because all the sediment collects on the
outside of the cloth. Occasionally, the cloth.- can be re-
moved and washed in gasoline or kerosene to thoroughly
clean them.
The filter is built cm the unit principle, and has been
constructed with a capacity of toOO gal. per hour in a
single unit.
:■:
©im'tts for E^effriE©Fom4Eimtf Emu
>n
l!v Thomas (f. Thueston
SYNOPSIS — Thirty-four sensible "don'ts" for the
operating engineer handling refrigeration machin-
ery.
Don't start an ammonia compressor without first not-
ing that the discharge valve is open. The writer remem-
bers when this was overlooked in starting a 250-ton ver-
tical machine, and two men who were working up under
the ceiling above the machine came near being overcome
with the gas. If the machine is not provided with a re-
lief valve, the head is liable to he blown off.
Don't forget to turn the water on the condenser just
before or immediately after starting the machine. If
this is not done until the head pressure becomes high,
leaks are liable to start in the condenser, both from the
excess pressure and the increased temperature. If al-
lowed to go too long the results will be as bad as for-
getting to open the discharge valve.
. Don't neglect to watch the head pressure while starting.
The header valve on a condenser had been shut, and the
operator, in a hurry to start, forgot it and blew the re-
lief valves. Watching the head pressure will warn you,
if you have forgotten it, to turn the water on the con-
denser.
Don't be m too much of a hurry to open the suction
valve when starting, especially if the machine has been
shut down for a long time, without pumping down the
expansion coils and suction line. Open the valve slowly
and keep your hand on the discharge pipe if possible. If
this suddenly gets cold and the discharge valves begin to
work unusually quietly, there is liquid coming back with
the gas and the suction valve must be choked off until
the machine begins to warm up again, otherwise it may
wreck the compressor and may cause loss of life. If
there is a slamming, or pounding, in the cylinder similar
to an engine getting a dose of water, shut the suction
valve until it stops, as this i< an indication of a danger-
ous condition.
Don't forget to close the suction valve when shutting
down even for a little while, and don't forget to close the
liquid valve in the liquid line from the receiver to the
expansion coils, or to close the expansion valve when
shutting down a machine, if it is working alone. If
these are not done the liquid will accumulate in the ex-
pansion coils and the suction line and make trouble when
starting up again, or until it is pumped out.
Don't forget to watch the stuffing-box when starting
up. This usually has to he tightened when the machine
has been shut down for a long time, and it must be let
out again gradually as the rod and packing warm.
Don't try to run the packing after it gets burned or
hard ami lose< it- resiliency. It will wear the rod and
waste ammonia. Packing is cheaper than new rods or am-
monia.
Don't run the crossheads loo loose on an ammonia com-
pressor, and don't tighten the crosshead -hoes any old
way. Either will make trouble in the stuffing-box. Put
the compressor crank on the crank-end center and adjust
the shoes so that the piston rod is the same distance from
the guides at both ends of the stroke.
On the compressor the thrust of the connecting-rod
usually presses the crosshead against the top guide except
when the crank passes the center, when the weight of the
crosshead drop- it down on the bottom guide. If the
crosshead is loose this will cause the packing to leak and
wear it out quickly. This applies only where the engine
and compressor are placed parallel, or side by side; if
they are placed tandem, or opposite each other, the thrust
608
P U \V E R
Vol. U, No. IS
on the compressor crosshead is the same as m the engine,
and the guides should be adjusted accordingly.
Don't use more oil than necessary. If more is used it
gets through the packing into the cylinder or goes out
through the gas relief line into the suction pipe and the
machine and out into the system, where it makes trouble.
Don't pump oil into the compressor cylinder. Usually
enough oil leaks in through the stuffing-box and the gas
relief line in addition to what circulates around the sys-
tem to keep the compressor well lubricated. The only
exception I have ever found to this was a 200-ton vertical
double-acting machine. On this we had to pump about
one-half pint every twenty-four hours into the top of the
cylinders to keep the discharge valves working freely and
to lubricate the cylinders.
Don't neglect to blow down the oil traps regularly.
If you are not using more than a quart of oil every twenty-
four hours, blow the traps at least twice a week, although
even- two or three days is better. If more than this is
used, blow them at least every two days, and if the oil con-
sumption is a gallon a day they should be blown every
day.
Don't run the compressor excessively hot or ice cold:
either one means loss of efficiency and capacity. The best
results are had in the average plant by keeping the tem-
perature of the discharge so hot that the hand can be held
on it without burning.
Don't circulate water in the water jacket if the water is
not warmer on leaving the jacket than on entering. To do
so wastes water and refrigerating capacity.
Don't be satisfied with any suction pressure. Experi-
ment with the expansion valves and see how high you
can get the pressure without making the machine too
cold; then try and keep it there unless the temperatures
drop.
Don't run with a high head pressure unless it costs
more for water to keep it down than for coal to pump
against it.
Don't neglect to purge the air and foul gases out of
the condenser regularly ; this will help to keep the head
pressure down. Any time the head pressure begins to
climb without apparent reason or some of the coils get
cold it is an indication of air or foul gas in the conden-
ser, and the latter should be purged.
Don't neglect to pump out the air before starting in
case any part of the system has been opened for alterations
or repairs; it will save the trouble of purging it out of
the condenser later on and save ammonia, as some am-
monia always escapes with the air when purging.
Don't pump a vacuum on the system unnecessarily;
it is likely to draw air into the system, and you will have
to purge it out again.
Don't run with an insufficient charge of ammonia;
keep enough in the system so that there is at least from
four to six inches in the gage-glass on the ammonia re-
ceiver when limning at maximum capacity. If the liquid
level gets too low, some of the gas will pass over to the
expansion coils with the liquid. Power has been used
to compress this gas and water to cool it, and when it
passes the expansion valve it will take some of the liquid
that you have spent power and water to produce to cool
it to the temperature of the suction gas. You are not
only doing useless work in compressing and cooling the
gas, but doing so absorbs sonic of the useful work already
done, reducing the capacity and increasing the cost of
operation.
Don't neglect the ammonia leaks. It does not take long
for a dollar's worth of ammonia to leak out if there are
a few small leaks in the system. Every week go over
the points in the system with a lighted sulphur stick.
The machine, and the high-pressure side of the system
especially, need watching. Test the condensing water,
jacket water and brine with litmus paper or Nessler's
solution.
Don't neglect to shut the water off the condenser if it
is shut down for any length of time, especially if it is
old and subject to leaks: allowing the water to circulate
over it cools it too quickly and may start a number of
new leaks.
Don't neglect to clean the frost off direct expansion
coils. The best way to do this is to run a hot gas con-
nection from the discharge of the machine to the liquid
line and pump hot gas into the coils ; this will clean them
quickly and thoroughly. Clean coils mean lower tempera-
tures or the same temperatures at a reduced speed of the
machine and therefore reduce the operating cost.
Don't neglect to inspect the valves and the false
beads if there are any: see that they seat well, that the
springs are not broken and are of the proper tension, and
that there are no scored places on the seats and valves
where the gas can blow through.
Don't neglect to pump out thoroughly before opening
any part of the system for alterations or repairs; some
men have a habit of letting whatever gas is in the ma-
chine blow to the four winds. It is just as easy to pump
it out, much nicer to work around, and it saves the am-
monia.
Don't break open an ammonia joint or any part of the
system until you are certain the pressure is off, and don't
be too quick in opening it even then. Loosen the bolts a
little and open the joint easily. In case there should be
pressure on it you can draw it up again before it gets
too strong for one to stay around it. You will at least
have a good chance to get away. Some men have lost their
lives by neglecting to take this precaution.
Don't pull up too hard on a joint that is under pres-
sure ; you may break the flange, lose your life, and a part
of the ammonia charge. If a joint does not stop leaking
after it is drawn up reasonably tight, pump the line out
and renew the gasket.
Don't get excited in case anyone gets a dose of liquid
ammonia or ammonia-saturated oil; douse him with
water. Turn the fire hose on him if there is one.
Don't connect a stop valve in an ammonia line so that
the flow of the gas or liquid tends to close the valve. The
writer remembers two cases where the valves came off the
stems and caused much trouble. In one case the valve
shut off the flow and blew the relief valve on the com-
pressor. It took much time to locate the cause. In
the other case the valve did not stop the flow, but ham-
mered back and forth on the scat, wearing the disk and
seat so much that a new valve was needed.
Don't neglect to keep the oil out of the expansion coils.
It there arc signs of oil Ln the system, open the coils as
soon as they can lie spared and blow them out. first with
steam and then with air, and lie sure they are thoroughly
dry before closing them.
Don't open or shut a valve without first checking to
make sure that it is the right valve.
Mav 1, 1915
P 0 \V E E
609
Don't be in too much of a hurry when pumping an air-
pressure test with an old machine on n system that has
been in service for a long time. II' there is oil in the ma-
chine or discharge line, it may cause an explosion due to
the compressor getting hoi enough t<> ignite the oil. Run
tin- machine slowly and keep plenty of water en the water
jacket if it has one. If the machine or the discharge
line gets very hot. shut the machine down until it cools.
Don't forget to keep up a rapid circulation of water
when pumping out a double pipe or a submerged con-
denser. Otherwise it will freeze1 and hurst. The same
also applies to a brine cooler.
Don't leave the suction lines uncovered outside of the
coolers. It means extra work without anything to show
foi It.
Don't run an ammonia plant without an ammonia hel-
met. When something blows out some day it will save
its cost in ammonia and mav save life.
are made in two sizes, one for collecting over an 8-hr.
period and the other over a 24-hr. interval. The col-
lection chamber is tapered to compensate for the change
in the rate of flow of the water from the chamber due to
the decrease in static head as the water lowers in the
-_^
"kfib
B 1
B^l
— — ■jlfl
1
«ggS
■So
Ta
'cc/i
B>©H<eir=JR©©tr!a
a8\.ime©s
The accompanying illustrations show the principal
portable instruments recently developed by the Defender
Automatic Regulator Co., Oriel Bldg., St. Louis, Mo.
Pig. -1. Di ples I (raft Gage
vessel. Consequently, the gas is drawn in at a con-
stant rate and an average sample for the entire period
is obtained. A gage glass on the collector is provided
to indicate the height of the water at any time.
Fig. 4 illustrates a "duplex" draft gage for indicating
the draft in the furnace and at the damper or stack,
and the drop in draft through the boiler. Outlet A
connects with the lower or longer tube, which has a
range up to 1 in. and is generally used for the uptake
Fig. 1. Three-Pipette Machine
Fig. 2. Single- Pipette Machine Fig. .:. Gas-Sample Collector
Fig. 1 is a modified type of Orsat with three pipettes
for determining the C02, 0 and CO contents of the Hue
gases. The ease and covers are of metal, and the header,
ordinarily of glass, is here made up of rubber connec-
tions and glass tees, not subject to breakage.
A single-pipette apparatus for use where the Co. ion-
tent only of the gases is required is shown in Fig. 2.
Fig. 3 is a combination gas-sample collector and CO.,
anatyzer. Where desired the gas-sample collector is
furnished without the analyzer attached. The collectors
draft. Outlet B connects witli the shorter tube, which
has a range up to 0.9 in. to measure the furnace draft.
The difference between the two readings gives the drop
in draft through the boiler. These gages are furnished
mounted in either an inclosed or open aluminum case.
In addition to the instruments illustrated the company
also makes a high-range brass-inclosed thermometer for
flue-gas temperature observations, single-tube draft gages
and a ••multiple" type draft gage mounted on a wooden
panel for direct attachment to the boiler.
lilt)
I'll WEK
Vol. 41, No. 18
Sa-vasag Ies F©dl®rs.Il H^aaSdliiirftg
> > > o) 2-
Since its inception in 1905 the Federal Building in
Chicago has been equipped with a boiler plant to supply
steam for hydraulic elevator pumps, engine-driven air
compressors serving a pneumatic-tube service, fan engines.
boiler-feed and service pumps, and some live steam for
the heating system. The exhausl from the units just
mentioned only supplied about half the heat require-
ments of the building in the colder weather. Current for
light and power had been purchased from the central sta-
tion at a price of 1.9c. per kw.-hr. for the first 100,000
kw.-hr. per month, and 0.9c for all current in excess of
this amount. Eventually, it was decided to install a gen-
erating plant that would produce all the current needed
and at the same time furnish more exhaust steam to the
heating system. This equipment was described in the
Apr. 28, 191 1. issue of Power, and from the saving made
in the first month of operation it was estimated that the
gross saving would exceed $1 i.nno a year. As shown in
the accompanying table, this estimate has been exceed. '.1
by nearly $2000. In exact figures the gross saving ef-
fected by the plant during its first year of operation was
$15,984.70. The total investment for the generating
units and all additions to the plant was $43,000. Allow-
ing 5 per cent, for depreciation and 3 per cent, for in-
terest, which is more than the government usually re-
ceives, gives $3440 to be deducted from the total saving.
This still leaves a balance of $12,544.70, which is over
29 per cent, on the investment and indicates that the
plant will pay for itself in about 3i/o years.
In the previous article the entire equipment was given
in detail and in the following it is briefly summarized-
The building is equipped with 45,000 sq.ft. of indirect
and 65,000 sq.ft. of direct radiation on a two-pipe vacuum
system. Seven passenger elevators of 3000 lb. capacity
each, four 4000-lb. freight elevators and four 2000-lb.
hydraulic lifts are served by one pumping engine, 16&20x
20x5^4x24 in., and two duplex tandem-compound pumps,
Iii,\25x7%xl8 in., working against a water pressure of
750 lli. For the pneumatic-tube mail-handling system
there are four air compressors driven by cross-compound
engines ranging in capacity from 75 to 125 hp. There
is also a 20-ton absorption refrigerating system to cool
the drinking water. To serve this equipment, five 350-hp.
water-tube boilers had been installed. This gave plenty
of reserve capacity for the generating plant. Incidentally,
its installation did not increase the number of boilers in
operation. There was plenty of unused space in the
basement for the four generating units which were event-
ually installed. Two of these are 200-kw. machines and
two 100-kw. generators directly driven by four-valve en-
gines.
Steam How meters are installed for the different ser-
vices, and a water meter measures the total amount of
boiler feed. The monthly and yearly totals, as read from
these meters, are given in the table. With more exhaust
steam to heat the feed water, it will be noticed that the
average evaporation per pound of coal is 8.18 for 1914-15,
as compared to 7.3 for the previous year. About the
same amounts of steam went to the elevator pumps and to
the air-compressor engines. The live steam to the boiler-
feed pumps, fan engines, heating system, etc., was consid-
erably less, as there was more exhaust available for the
2|;
cS a
f^a
m
K
~W-
<
H
■~x6
'"•73
><
O
Z
P-M°
h
b
d t-'S1*"
O
"P
o
a
. «<"£
w
-
0
Tot
\V:il
3 LSol
Lb
V.
«
>
i-'i,
o
u
oooooooooooo
fed t- S > 01
I I II I I I I I I I I
1 1 1
1 1 1 1 II 1 1 1
Mi
1916
row ]•: i;
611
heating system. Prom the Isi of May to the end of Feb-
ruary the engines used 52,827,422 lb. of steam. Dividing
by the total kilowatt-hours generated in the same period,
the consumption per kilowatt-hour is 15.8 lb. During
the night hours the engines operated at light Loads and the
pressure was dropped to 1 Hi lb., as compared to L60 lb.
during the day. Besides, in the early part of the year all
of the units were tuned up and more machines operated
than were necessary. These [actors account for a water
rate which is higher than may be expected In succeeding
years.
With the demands made by the other services about the
same, the generating plant caused an additional operating
expense of $8873.05, excluding the amount paid for cen-
tral-station current. Dividing by the total output, the
cost per kilowatt-hour amounted to 0.623c. The increase
in coal consumption was 1926 tons, and to operate the
generating units two extra men wen' required. The
wages tor these extra employees, coal at an average of
$3. ill per ton and the additional oil and supplies required
made up the excess in operating cost just referred to.
When the $24,857.75, the amount paid tin- central sta-
tion for current, is added to the operating expenses of the
plant, the total of $67,760.98 for the year ending Febru-
ary, 19] l, exceeds the total expense for last year by $15,-
984.70. It is true that the current used during the year
■■■is less by 85,620 kw.-hr. More current was used for
lighting, hut the power demand was considerably reduced
ow ing to changes in the service and to doubling up motor-.
making one do where formerly two had been employed.
Had it been possible to reduce the electrical service in
1913 to the same figure, the amount paid for current
would have been reduced $770.58, as the excess came un-
cle]- the 0.9c. rate. Putting both years on an equal basis,
the gross saving would then be $15,214.12. Deducting the
•$34 10 for interest and depreciation leaves a net balance of
$11,71 (.I'.', which is 27.4 per cent, on the investment of
$43,000.
attio ©f Ore^m£ereinitig\J to L©in\g1itai<
dliirml Stresses imi Bonier Joiinite
By. .1. K. LlNDERHURST
SYNOPSIS — 77,,. article considers those condi-
tions which sometimes make the ratio of tin1 cir-
cumferential tu the longitudinal stresses more than
lint to one.
The average engineer who knows how to calculate the
strength of boilers usually believes that estimating the
strength of a cylinder to resist internal pressure is
a simple problem. It' all the factors are considered
the problem is not simple, and the calculation of the cor-
rect efficiency of the longitudinal joint, usually consid-
ered the most difficult part of the problem, is one of the
simplest.
Fig. 1, for example, is a part of a seamless cylinder,
and if one were asked what is the relation between the
circumferential and lengthwise stresses, he might state
at once that the former is just twice the latter. The
mathematical demonstration that this is so is apparently
simple, for if the portion of this cylinder is taken of
such length that the lines LM and A'.V equal the cir-
cumference of the cylinder, then the area on which pres-
sure is exerted and tends to produce rupture is 2 r X
LM. when r is the radius of the cylinder.
The area exposed to pressure that will exert a length-
wise stress is the internal cross-sectional area id' the cyl-
inder, or 3.14/-. Now, since we have taken LM equal
to 3.1 1/-. or one-half of the circumference of the cylin-
der, the first expression for area becomes «Jr X 3.1 Ir.
or (i.'iSr2, which is twice the amount of the figure ex-
pressing the area of the internal cross-section, and
therefore the lengthwise stress should be one-half of the
circumferential.
No attention was given to thickness in making these
calculations, for the shell was considered as a line with-
out thickness. In Fig. 2, the thickness of the cylinder
i- indicated by the cross-section lines, and it is seen that
if the circumference on the diameter KL is equal to LM
and A'.V. the area of metal alone LM and 7v".Y will not
quite equal tin- cross-sectional area of the -hell as indi-
cated by the section lines, because this area equals the
thickness time- the mean circumference, which is half-
way between the outer and inner surfaces, and not the
thickness times the inner circumference.
Another factor not usually considered, and one which
make- the difference between the longitudinal and maxi-
I i.i.i jstr \n \i. Relation of Circumferential to
Longitudinal Stresses in Boiler Joints
mum girthwise stresses greater than the one to two ratio,
is as follows :
In considering the strength of cylinders, where the
thickness is small as compared to the diameter, it is not
customary to assume that the circumferential stress is
unequally distributed over the thickness of the plate: but
such i- the case and. instead of the stress being equal
throughout the plate thickness, it is greatest along the
inner surface and leas! alone the outer. No -tress
612
F 0 W E R
Vol. 41, No. 18
within the elastic limit of a material can be applied with-
out producing corresponding stretch. Since a cylinder
cannot increase in diameter without stretching the inner
surface a proportionately greater amount than the outer,
the stresses in the plate will not he uniform. This is evi-
dent, if we consider a cylinder made up of concentric
layers, as in Fig. 3. If such a cylinder were cut open
to be free to expand, internal pressure applied to in-
crease (he diameter would cause the dimension W, which
is the amount of separation of the outer layer, to lie equal
to F. if the layers of material were very thin. This il-
lustrates how the material is supposed to behave in a solid
plate cylinder under pressure. Since the actual stretch
of all layers is the same, the stress produced in them is
not uniform, on account of their varying length. The
difference in the strength of a cylinder calculated in this
way and one figured in the usual way is expressed by the
ratio between the length of the outer and inner circum-
ferences of the shell; or, since these circumferences are
directly proportional to their radii, the ratio would be that
between the inner and outer radii. For example, in Fig.
4, if /. were of such dimensions that it would equal one-
quarter of r (r being the inner radius of the cylinder),
then the strength calculated in the usual way would be
thickness X strength of shell per sfj.in.
inner radius
= bursting pees
Assuming ;■ at 4 in. and, therefore, / at 1 in., and 50,000
lb. per sq.in. as the strength of the shell material, we
have, as bursting pressure,
1 X 50,000 ,
4
If the fact that the circumferential stress is not even-
ly distributed in the shell is taken into account, the burst-
ing pressure is found to be
x <•"'"''• "'i^, or i,,500 X | = 10,000 lb.
outer rmtius
bursting pressure, which is a difference of 20 per cent.
In boiler shells, where the diameter of the boiler is
large, as compared to the thickness of plate, neglecting
this feature in estimating the strength is not of impor-
tance but to show the effect it may be well to consider an
example. Take a boiler of 60-in. inside diameter and
made of i^-in. plate subjected to a pressure of 125 lb. per
sq.in., the boiler being assumed to be seamless. The load
carried in a girthwise direction is
125 X 30 X 2 = 7500 lb.,
but as this load is not equally distributed throughout the
thickness of the plate, the maximum fiber stress at the
inner surface is about 7620 11). per sq.in. The endwise
-tic-- is due to the pressure of 125 lb. on an area of
2827.43 sq.in.. or a load of 353,428.75 lb. The area of
shell available to support this load is 17.4 sq.in., which is
the cross-sectional area of the shell. Therefore, the stress
per square inch longitudinally is
353,428.75
47.4
= 7456 lb.
-o that the highest fiber stress girthwise is something
Over 2 per cent, greater than the lengthwise stress in the
shell of this boiler when considering it as a cylinder
without tubes. As ha- been stated, the slight difference
in calculating boiler shells by either method is not enough
to warrant consideration. It is well, however, to know
just what we are talking about when we state that the
girthwise stress in a cylinder subjected to internal pres-
sure is twice the longitudinal stress.
Some like to express the relative values of these two
stresses graphically and state that, as in Fig. 4, if we take
any horizontal length of the shell, as /. and a correspond-
ing length on the circumference /, the pressure on the tri-
angle inclosed by the two radii produces the stress length-
wise of the shell on the section 1 in. long, and that the
stress in the circumferential direction is due to the pres-
sure on the rectangle Ir. Since the area of this rectangle
is just twice that of the triangle, the stress due to the
pressure is in the same proportion.
The difficulty in this case i> the same as in the case
of Fig. 1 as regards accuracy, for only lines have been
considered without thickness. If the metal to stand the
load is to be equal in both cases, the length 1 in the
case of the circumference of the shell would have to be
taken on the mean circumference, in which case the tri-
angular area would not be one-half of the rectangular, and
therefore the resulting stresses would not be in the ratio of
one to two.
This latter method of comparing the values of the
stresses in a cylinder is called the graphic method.
SpeciiScsiSSoias foir §G©as.m ILsnaes
By D. Ckaft
In specifications for steam lines for power using high
pressures of steam, a mistake is commonly made in call-
ing for lines as large as the connections of all the engines
and turbine. It appears to the writer that many of the
small engines and turbines used in power-plant work are
provided with connections which are made large enough to
supply the steam required at the minimum pressure likely
to be used by any purchaser for the maximum rated ca-
pacity.
In our plant the piressure carried is 175 lb. All of the
smaller machines here were originally connected to steam
lines out of proportion to their capacity. For instance,
two 5-hp. Terry turbines driving hotwell pumps had l1 r
in. steam lines: a 6x8x6-in. air compressor compressing
to 50 lb. had a 2-in. line; two 6x9-in. engine- driving cir-
culating pumps and carrying a 6-hp. load had 2l/2-in.
steam lines, and there were several similar instances of
excessive sizes of connections.
We have reduced some of these lines to one-sixth
of their original capacity. In addition to reducing losses
from saving radiation we have saved considerable in ex-
pense and annoyance of keeping large throttle valves tight,
and there is a marked reduction of governor trouble. The
large governor valves throttled the steam so closely thai
from wiredrawing of the steam the valves required fre-
quent grinding, reseating and renewing.
By reducing the size of these valves and lines we have
overcome our trouble. Where we made these reductions
in pipe sizes the lines were made only large enough to
transmit 30 lb. of steam per hour for each horsepower re-
quired, with an allowance of about in per cent, for drop
in pressure.
The Most Economical Pipe Size for the average demand
should be used, with provision for increasing the boiler
pressure or opening a supplementary "booster" line during
maximum demand when the engine cannot otherwise carry
the load. Recent tests here and abroad prove that sub-
stantial saving may follow a reduction in pipe size or shutting
off booster lines, thereby saving in condensation and radiation
losses.
.May 4, 1915 POWER
um iniiiiiiiiiiiiii iiiiiiiiiiniiiiiiiiiiii iiiiiiiiniiiiiiaiiiiiiiiiiiiiiiii iiiiiiiiiiiuiiiiiuiiuii mi uwiimiuiiiiiiiii um ™«
613
umiiii iii ii ihiiiiiiiiiimiiii mm iiiiiiiiiiiiiiiiiiiiih
Editorials
Facftotrs aim tHe JEsaga!nieeiri,s
What determines the contents of the engineer's pay en-
velope? Surely, in too many cases his salary, or whatever
his remuneration may be called, is the result of custom
mi the part of the establishment which he serves — a sort
of haphazard adherence to the "going" rate of pay in the
local community in this occupation. Surely, there are
other standards by which employers may fairly gage the
worth of their engineers — standards which take into ac-
count their responsibilities, their service performance and
powers of constructive suggestion.
Because a ten-thousand-kilowatt turbine today requires
less attendance than a two-thousand-live-hundred-kilo-
watt engine-driven unit did a dozen years ago, some people
doubtless think that the engineer has an easier time in a
typically modern plant, and therefore is not entitled to
higher compensation. Again, some hold that because a
plant is put on an eight-hour shift where a ten- or twelve-
hour schedule was formerly maintained, the engineer's
duties are correspondingly lightened and he deserves little
consideration in the direction of "raises.''
If any single factor is to be picked out as paramount
in rate-making for operating engineers, that factor should
be responsibility. The value of the service rendered by
the plant is one great test, and the value of the equipment
in the engineer's charge is another. It matters little
whether the machinery is highly automatic in its opera-
tion so far as engineering responsibility is concerned,
compared with the amount of money invested in it and
the penalties of service interruptions. There may be
less manual effort in handling a fifteen-thousand-kilowatt
turbine and its auxiliaries than in operating an engine-
driven outfit of a fifth that capacity, but the risk of dam-
age, the question of daily cost when such a machine stands
idle, the importance of its output, and the value of tech-
nical judgment in inspection and maintenance, all tend
to place the man in charge of high-powered units in a
special class as regards payment — a class which is recog-
nized in many concerns, but which on principle ought to
be appreciated all along the line more than it is.
In a word, the hours of daily service should cut little
figure in salary or wage detei initiation, and the same may
be said of the output per unit. At first blush, the plant
turning out a big total of daily horsepower-hours might
be set up as a standard of payment, but while peak loads
increase the engineer's anxieties, the daily test of his
work comes down to his ability to turn out whatever out-
put the load demands, at the lowest cost consistent with
reliable service. The ability to save the plant owner
money, realized in the daily work of the engineer, should
not go unrewarded. Profit sharing is just as good a
plan in the power house as in the factory, but a g I
many employers have yet to realize it. Certainly, the
engineer who works diligently to improve the efficiency
of his installation, who studies how to make it yield the
best possible service, and who knows from accurate records
ni :..■•■: ..,.,,.
just what the physical results of those efforts are, is dem-
onstrating his fitness for responsibility and is keeping
his "cutting edge" sharp to good purpose.
Analysis of local conditions in power plants should ac-
company consideration of the problems of compensation
in the future, and the farther the plant owner gets from
mere imitation of what others are doing, the better it will
be for all concerned.
uradl ftlfive
A chimney has two principal functions— one to produce
a draft, the other to take the gases high enough above
our heads so that we do not notice them. Until someone
invents an invisible chimney we shall have to put up
with tall tubes sticking up into the sky line.
Various attempts have been made to disguise chimneys
in the interest of the artistic. Greek columns, campaniles
and other architectural units have been pressed into ser-
vice, but the incongruity of such works of art belching
clouds of smoke has made them less artistic than the chim-
ney which pretends to be nothing but a chimney. Brick
and concrete afford materials which can be made more
or less ornamental — the former by shape and color, the
latter by shape alone. The steel stack seems seldom to be
anything but a parallel tube without ornamentation.
A steel stack has very decided advantages from a finan-
cial point of view. If it had to he replaced every year
it would cost only about what the interest would be on a
brick stack and its foundation. As it lasts from five to
twenty-five years, according to the coal and weather,
there is little to be said against it except as a matter of
looks. There is a prejudice on the ground that it will
not draw, but that is probably ill-founded. If there were
any great difficulty from radiation it could be helped by
means of a jacket or an inner tube, neither of which
is often resorted to. On the score of looks there is noth-
ing that can be said in favor of the ordinary factory
stack. A degree of ornamentation is sometimes attempted
by painting colored bands or by lettering the name of
the owner on the side, but that is bad in that it attracts at-
tention to an ugly thing.
It would seem as though a steel stack could be designed
the lines of which would be at least pleasing when seen
from sufficient distance so that the material was not in
evidence. There is no insurmountable difficulty in mak-
ing a tapering tube of steel. It is even possible to give
it the slight swelling which appears to be necessary to
make it look like a straight taper. The largest expense ap-
pears to be for an ornamental head, which may cost as
much as the rest of the stack, but which, if made on
simple lines relying on distance to obscure the lack of
detail, should not be very expensive. Then if, instead of
painting it a dead black, it could he made a gray or
some neutral color, it would be still less noticeable, and
that is the real object to be attained — practical invisibil-
ity, or making it attract as little notice as possible.
(il-i
POWER
Vol. 41. NTo. 18
LooMissgi <Qw& foi? tithe Fnirae P©iin\tts
The small details in the layout of a power plant, al-
though often receiving scant attention, are important fac-
3 in its operation : and it is surprising how nearly every
plant illustrates practice which is either worth following
or which might well be avoided. Station lighting, for in-
stance, too often receives insufficient consideration, par-
ticularly in the use of shades or reflectors capable of con-
centrating the light on machine parts needing frequent
inspection or adjustment. Also, the use of unshaded
lamps mounted low on columns in stations with high ceil-
ings is extremely wasteful. Boiler rooms are notoriously
ill-lighted in many stations, and here is a field for the
practice of engineering skill along lines as yet relative!)
undeveloped. No lighting installation, however, will give
adequate results if neglected as to periodical cleanh
fixtures.
The numbering of switches and motor starters to cor-
respond with the apparatus controlled has important
hearing upon convenience of operation. In emergencies
requiring the sudden stopping of a motor-driven centrifu-
gal pump and the starting of another, no time should be
lost through the manipulation of the wrong switch. Sim-
ilarly, the labeling of lighting switches with appropriately
keyed circuit numbers, including specific areas covered,
when feasible, is desirable. The mounting of generator
field rheostats sometimes is a troublesome problem. In a
recently completed station this apparatus was placed be-
hind the switchboard, but so far above the floor as to
obstruct, the light from the windows, consequently it had
to be blocked up with a wooden strut which obstructed the
passage at the rear of the board. In a section of the plant
containing refrigerating coils, lights were placed on the
alternate stairway landings only, thus giving too dim an
illumination for rapid and safe travel, and in the freezing
room no effort was made to protect the local switches and
fuses from vapors.
Although many of these loose ends are taken in hand
after the plant is in regular operation, they are usually
sources of inconvenience, extra cost, and danger, and
should be guarded against wherever possible.
Produce
Frequently, the operating engineer of a factory power
plant is called upon to make changes or extensions to the
existing plant, possibly occasioned by the addition of build-
ing or machinery made necessary by the desire of the
owner for increased facility. At such times the import-
ance of intimate knowledge of details of the existing power
plant, together with the exact knowledge on the part of
the operating engineer of the actual value utilized of the
owner's dollars worth of coal, cannot be too forcibly in-
sisted upon.
The operating engineer who is content to just operate
his plant without knowing exactly what part of the own-
er's dollar invested in the coal pile is being put to useful
purpose, will fail when called upon for advice to meet the
new conditions. He is the one who will sulk in the cor-
ner when the boss employs outside talent to solve his prob-
lems. In the corner with his face to the wall he will re-
main, for he has entirely neglected to grasp and use the
opportunities given him.
How many operating engineers have traced the pound
of coal fed to the boiler from the pile to the switchboard ?
How many ever stop to realize that only about fifteen
cents out of a dollar's worth of coal actually reaches the
switchboard!' The missing eighty-five cents in too many
instances is almost a total loss, whereas with proper
knowledge and equipment as much as sixty cents of this
can be saved and put to proper use.
The salesman who sold the engine and generator boasts
about the combined efficiency of his apparatus being !)-J per
cent. This is not to say that the owner is getting ninety-
five cents at the terminals of the generator on the dollar
paid for coal. He is not. This combined efficiency means
that for every hundred pounds of steam given the engine
at the throttle, all the electrical energy that can be
obtained from ninety-five pounds is realized at the ter-
minals.
Possibly one will ask. why try to save the exhaust
a from the engine? The answer is that the steam
exhausting from the engine contains more than twice as
much heat value as is actually used in the engine and
transformed into electrical em
The exhaust steam should be turned to good use, such
as heating the buildings, or possibly supplying apparatus
required in the process of manufacture, such as drying
looms and kettles, and also to heat the feed water sup-
plied to the boiler, thereby reducing the work required
from the coal.
Until recently, the owner invariably looked upon the
coal bill as a necessary evil. Times are changing. The
efficiency engineer is making rapid progress. Be in a po-
sition to tell the boss just where his dollar's worth of coal
is going. Maybe, when he asks your advice on new equip-
ment you can tell him that by making certain changes
in the existing plant, there will be boiler capacity enough
to carry the increased load, thus materially lightening
the burdens on his pocketbook.
Don't wait for the efficiency engineer to tell your boss
where his money goes; get there before him. You are
the one that should tell him.
8
Is it any more onerous or less reasonable to require a
user of a boiler to provide it with an adequate safety valve,
than to require him to furnish an adequate fire pump ; to
insist upon an open exit from a fire-room which is liable
to become a torture chamber filled with scalding steam
from the bursting of a steam pipe or fitting or of a boiler
tube, than from an ordinary workroom; to require the
furnace doors which will not allow the fire to be
blown out over the premises and the people, and to pro-
vide an outward escape for the steam and gas from a boiler
setting in case of a bursting tube, than to insist upon
guards around belts and flywheels? Has not "safety first"
a- much import in the power plant as elsewhere?
:♦:
The head of an organization of steam-boiler firemen in
New Jersey recently informed us that the educational
v ork that has been vigorously conducted among engineers
in that state during the past few years has had the effect
stablishing unusually favorable relations between
engineers and firemen. There is more thorough coopera-
tion between the two today than ever before, he stated.
m
When the average man begins to educate himself he soon
learns that he does not know as much about his calling
as he thought he did. Once he is conscious of this, he is
likely to be less arrogant and more helpful to his subor-
dinates.
May 4, 1915
P 0 W E E
Coinr esjpoimdleiniee
^IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIUIIIIIIIIIIIINIIIIIIIII IIIIIIIIIIUIIIII 1IUIIIII [ I !l!ll!l!ll!!llllllll!:ill Ill ill ...
Referring to the request by Charles S. Palmer, as
printed on page 481 of the Apr. 6 issue of Power, and
in particular to the question relative to the maximum
lift that the steam ejector when applied to priming
centrifugal pumps can be expected to develop, I offer the
following :
The depth in feet from which the water can be raised
to the pump by vacuum created by the ejector depends
upon local conditions, such as tightness of piping and
pump parts and the steam pressure used. Theoretically,
it should be 33+ ft., which would indicate perfect vacuum,
but in practice 25 ft. is near the maximum when the
best range of steam pressures — -40 to 80 lb. gage — is
employed, and all valve stems, stuffing-boxes, pump and
pipe joints are tight against air leakage. Usually con-
siderable care must be exercised to keep the air leakage
down to a minimum.
With Mr. Palmer, I should be much pleased to receive
through your columns the common-sense explanation of
the collapse of the discharge pipe on the pump mentioned
in the article referred to.
Penberthy Injector Co.,
L. A. Purcell.
Detroit, Mich.
Psriitiffiiair&gl .m C^OE&foHiiraflggall P^jtEimp
Some years ago I had the pleasure — and the work —
of spending a season at a fairly large-sized irrigation
plant in the cane and rice belt of southern Texas. I do
not remember the capacity of the pumps, but it was con-
siderable. There were two centrifugal pumps, each driven
by a tandem-compound Corliss engine of the nonreleasing
valve-gear type; the speed was 175 r.p.m. Each had a
separate suction and discharge, the former being 72 in.
and the latter 45 in. diameter.
These two pumps Formed one of the two plants that
were necessary to put water on the rice lands. The plant at
which I was stationed was called the lower lift. It was
on the Brazos River and the engine-room floor was about
50 ft. below the surrounding land level. This was neces-
sary, as the water level in the river became low during
the dry season, and then the pumps had about 12-ft. lift.
From the river the water was discharged into a canal
about 35 ft. above the pumps. At low water this gave a
total lift of something like 47 ft. The shaft stuffing-box
was, of course, water-sealed. These pumps would easily
lose their suction if they slowed down as little as five
revolutions per minute below their regular speed. They
always had to be primed when the water in the river was
lower than the engine shaft. There was no valve in the
suction line. The discharge line was provided with a gate
valve operated by hydraulic pressure, which was usually
assisted by a half-dozen men with chain blocks and bars.
There was a 4-in. steam ejector connected at the highest
point in the pump case. Whenever a pump lost its suction
it was stopped, the discharge valve closed and the ejector
started. Sometimes the air would be dispelled and the
case filled with water in from 15 to 20 minutes, but
generally it took over half an hour and sometimes longer,
owing to leaks in the pump and piping. The ejector took
more steam than the engine and the boilers were crowded
during priming. Often, while priming one pump the
steam pressure would become so low that the other would
slow down and also lose its suction. There were times
when the ejector would just begin to discharge water when
it would have to be shut off owing to the danger of the
other pump slowing down.
As soon as the ejector began discharging a full stream
the pump was started and brought up to speed as quickly
as possible. The discharge valve was never opened till
the pump was up to speed and then opened slowly. It
was inconvenient to start either of these pumps with the
discharge valve open. Although the ejector was a
veritable steam eater it was the best means of priming
we could get.
The other plant of this irrigation system was located
about 19 miles from the river and took water out of the
canal and discharged it into the irrigation ditches which
supplied the rice fields. This plant was known as the
upper lift and the pumps were built on the ground level,
so there was scarcely any suction lift.
A. G. Solomon.
Chicago, 111.
So©£ IRetnmovgil
In the Feb. 16 issue I read with interest the editorial
"Soot," page 238.
Some time ago I made some observations on a horizontal,
vertical-pass, water-tube boiler to determine the effect
iBEFORETUBESl AFTER I5JPA55 | AFTER 2=SPAS5 |AFTER3^PA5S| AFTER BOILER
WERE BLOWN.HADBEEN BLOWN l MAD BEEN BLOWN .HAD BEEN BLOWN, MAD BEEN BLOWN.
Effect of Soot Removal
of soot removal on the combustion and the temperature
of the gases just after leaving the boiler.
It is our custom to blow the external surfaces of the
tubes off with compressed air at about 100 lb. pressure.
This is done daily except Sunday, which means that the
616
POWER
Vol. 41, No. 18
boiler is accumulating soot and dust for 48 hours. The
accompanying curves were plotted from data taken after
each pass had been blown.
The draft pressures and condition of the tire were kept
as nearly uniform as possible. The boiler is served by a
front-feed inclined urate stoker. The temperature was
taken at a point jusi alter the gases left the last pass.
The flue-gas sample was taken at the same place, and
analyzed with an Orsat.
It will be interesting to note in these curves the
peculiar relation between the draft pressures and CO,.
II. R. Blessing.
Philadelphia. Penn.
The editorial in a recent issue of Power relative to the
soot problem furnishes food fur thought. Why is it that
many power plants equipped with flow meters, C02 re-
corders, pyrometers, draft gages and other appliances
designed to promote boiler efficiency still stick to ancienl
hit-or-miss methods of removing soot deposits from their
boilers? In Germany power-plant operators realize that
soot has about five times the heat-resisting qualities of
asbestos, and most boilers have stationary soot-blowing
equipment.
In this vicinity such installations are, comparatively
speaking, few. The writer has in mind a plant where
boiler tubes are blown twice a week. After this blowing,
from 11^ to 2 tons of sunt is removed from each boiler.
The work is done by an attendant with a hand hose, and
as such men are but human, and dragging a hot steam
hosi about a boiler room is anything but a pleasant job,
more than one dust slide is skipped in the operation. The
time saved between the opening of a couple of valves on
a stationary equipment and the shifting about of a hand
hose is so apparent that no comment need be made on it.
There have been numerous interesting and instructive
discussions in Poweb on flue-gas analysis, boiler settings
and general power-plant practice, but this important
subject of soot removal has not received much attention.
Will not some who have equipment of this kind let us
hear about it ?
J. Pkiefer.
Brooklyn. X. Y.
Fuamaps
I read with a great deal of interest the article by ST. R.
Blish in the Mar. 16 issue. Mr. Blish devotes consider-
able attention to the measurement of the discharge by
means of weirs. I would like to suggest, however, that a
much more convenient way of measuring the output from
centrifugal pumps of either small or large size is by the
use of a venturi meter tube with a mercury manometer.
Such an arrangement is shown, herewith. The tube
is placed directly on the discharge from the pump and the
pump performance may be tested under actual operating
'ton- if desired. This arrangement also has the ad-
vantage of being permam at if so desired, and a daily rec-
ord of the pumpage ma] ept. Any falling off in per-
formance may lie noted a- -non as it occurs ami the trouble
corrected, if possible. If it is desired to test the pump
under a ads than could be obtaine 1 at
any particular time. ! ement ran lie mod
- ewhat by placing a valve directly on the outlet cone
ami throttling it to obtain the head desired.
Mr. Blish in his article describes the use of a baffle
plate to prevent serious velocity of approach of the water
to the weir. With the Venturi tube this will not be re-
quired since the method of measurement by taking pres-
sures at the upstream and throat or constricted portions
of the tube 1- independent of the initial velocity of the
flowing water.
The instrument is also considerably more convenient
to read than the hook gage used with the weir. The
manometer shown i^ a modification of the U-tube type and
employs the same principle as the single-tube mercury
barometer, the heavy pressure from the inlet of the meter
tube being received upon the surface of the mercury in the
Vextuki Tube and Manometer for Testing
Centrifugal Pi sips
large well at the bottom of the instrument. The throat
pressure is conducted to the top of the single glass tube.
The scale may fie graduated directly in gallons per min-
ute. This type of instrument makes unnecessary the ad-
justing of the scale or rod and is particularly convenient
in eases where it is desired to take frequent readings
of suction and discharge heads, speed, temperature, etc.,
at frequent intervals with a small number of observers.
Alan A. Wood.
Providence, E. I.
Feedlaica^ Gs'Siplhltl© to ]B©al©iPS
The writer has experimented for several months to
discover a satisfactory method of feeding graphite into
stationary boilers and has found the following to be best.
The feeder shown in Fig. 1 is used in plants where com-
pressed air is available, and that in Fig. 2 where com-
pressed air cannot be had.
Fig. 1 is composed of a 6-gal. galvanized-iron tank A
with a loose-fitting lid on top ; B is a 1-in. pipe extending
through the bottom and three-fourths of the way to the
top of the tank, with a tee on top to prevent the attendant
from filling the pipe with graphite when he is charging
the tank. A 1-in. gate valve or straight-way air-cock C is
used as shown. A globe valve should never he used here
on account of its liability to clog. A 1-in. line D should
be connected to the suction of the feed pump. A sight-
/.'. through which the attendant can sec the amount
of 'j raphite being led. is provided.
A > rin. line F should be connected to the city water
line or to the discharge of the feed pump. A nozzle 0
is used with a j^-in. opening pointing to the bottom <■
the tank on a 45-deg. angle, to prevenl graphite
May 1, L915
po w b n
617
Bettling to the bottom of the tank and keep it well mixed
with water. A l/o-in. valve / is used to drain the tank
for recharging.
This feeder should be installed, so that the sight-feed is
above the water line of the heater, and so that it will not
till with water.
To charge, close the valves H and C, open I, and drain
water into the bucket. If this water contains graphite it
Fig. 1.
Graphite Feeder Used Where C
Air Is Available
m PRESSED
can be put back into the tank after charging. After put-
ting in the required amount of graphite, pour the water
drawn from the tank hack into it, stirring the contents
well to mix thoroughly, open valve C wide and regulate
the feed with //.
Fig. 2 consists chiefly of a 150-gal. steel tank A, four
%-in. pipes B with g^-in. holes drilled 2 in. apart on one
Fig.
Graphite Pump Operated by. Boiler-Feed
Pump
and arranged in the tank so that the holes point
downward, to keep the graphite from settling. A Vo-iu.
air line C is connected to the compressed-aii supply; 1>
is a H^-in. suction line; E l^-in. swinging check valve;
F a single-acting pump made of 2-in. brass pipe with a
'.'J I oxl-in. pipe tee on one end and the boimet of a '.'■•'." L.
in. valve on the other. The piston brail is made of brass,
with two packing rings. The piston rod is made of %-in.
cold-rolled brass, with a permanent nut on the end of the
rod and a sliding nut with a setscrew, so that the stroke
of the pump can be adjusted to any desired length, regu-
lating the amount of graphite fed with each stroke of the
feed pump. The graphite pump is driven by the piston
rod of the feed pump; // is a 1 -in. discharge line, G is
connected into the suction line of the feed and contains a
1-in. swing check valve.
C. X. Wiley.
Pittsburgh, Penn
The diagram represents the connections of a three-
phase compensator for starting squirrel-cage induction
motors. The leads from the line and to the motor are flex-
ibly connected to the rocker-drum contacts marked ''off."
When the handle is in the position marked ''start," the
rocker makes the connections indicated by the double
dotted lines: and with the handle in the running posi-
tion, the connections are as indicated by the double full
lines. In the starting position the line wires connect to
the autotransformer terminals and the motor leads to the
autotransformer taps, thereby applying approximately
half voltage to the motor. In the running position the
line wires are connected directly to the motor leads so
FIG. I
Compensator Connections
that the motor gets full voltage. The autotransfonner
is then entirely cut out.
It will be noted that the fuses are in circuit only on the
running side. Inspection of the diagram also show- that
the three wires that connect the cylinder contacts t
motor are in use irrespective of the position in whicrrahe
starter may be; therefore, an open-circuit that affects
operation in both positions is either local to these motor
wires or to the line wires beyond the compensator con-
nections.
An operator complained that his motor would not Mart
from either side of the compensator, but would buzz,
thereby indicating single-phase operation. Just above
the compensator there was a small panel carrying the
uses and studs b\ means of which tl impensator wires
connected to the line wire- and to the fuses and
motor wiies. Connections were made with terminals
similar to that indicated in Fig. 2, the ends of the wires
being soldered into the sleeves and the eyes being slipped
618
POWER
Vol. 41, No. 18
onto the studs and held there with nuts. With a bell
the open circuit was finally located in the sleeve of the
terminal wire marked A, Fig. 1. This had been caused
by a laver of resin between the wire and the sleeve, the
resin having been used as a soldering flux.
J. A. Hokton.
Schenectady, N. Y.
H©ttes ©eh HiradlHC aft©^ Dns^s5 annas
In the Mar. 2 issue. A. R. Nottingham, under the above
caption, discusses freak diagrams, particularly one that
appeared in Power for Nov. 3, 191-4. He states: "In the
original diagram Fig. 1. the atmospheric line is 5y2 lb.
too high. It should be where the dotted line is, though
this does not affect the diagram so far as valve analysis is
concerned."
Granting that the diagram was taken from the low-
pressure cylinder, since neither the scale of the spring nor
the vacuum line is given, how did Mr. Nottingham arrive
at the conclusion that the atmospheric line is 5i/2 lb. too
high? As a matter of fact the diagram was claimed to
have been taken from the high-pressure cylinder of a com-
pound engine, and the atmospheric line should have been
below the exhaust line, equal to the receiver pressure,
which could not have been high in this ease as most of the
work was done by the high-pressure cylinder.
Victor Boxx.
New York City.
iOHfles0 of a, Tspgi©{ta©Ea B£E&gpnne
The photographs reproduced show the general ap-
pearance of a traction engine after the boiler had exploded.
The age of the boiler and the condition of the safety valve
and steam gage are unknown to the writer. The shell
was badly corroded and in one place had leaked and been
patched, as may be seen at the lower part of Fig. 3. The
weakest point seems to have been at the edge of the seam
(which joined the body to the firebox, where the sheet was
corroded nearly through. There was but little scale on
the surfaces.
The explosion occurred while the engine was standing
on the public highway. The shell was carried 300 yards
by the force of the explosion and the whistle was found
one-quarter of a mile away. Fortunately, no one was
hurt.
Clatlin, Kan. J. J. Beejiax.
b oi Shell
Fig. 1. Part of the Wreckage
Fig. 2. Sjiokei'.ox End
May 4, 1915
POWER
019
TUnaeqjtiaall Adip Crap
Some time ago the writer had some experience with a
generator failing to operate correctly, the cause of which
may interest readers of Power.
The machine was a 100-kw. 220-volt shunt-wound gen-
erator direct-connected to a gas engine, and operated
various amusement devices and lights at a summer resort.
The rated voltage would build up readily, but as soon as
any load was connected, the voltage would fluctuate and
the brushes spark badly, and no amount of shifting would
remedy the trouble. The engine was checked for its
Shims
inserted here,
instead of here
Frame Showing Where Shims Were Inserted
rated speed as shown on the nameplate and found correct,
and no appreciable variation was noted when load was
applied.
Upon inquiry it was found that the generator had just
been installed, having been purchased second-hand. The
field frame was split horizontally, and in order to facilitate
handling and shipment to its present location the gen-
erator had been taken apart. As the men who had set
it up were not experienced in handling electrical ma-
chinery, the natural conclusion was that possibly the
field coils had been wrongly replaced or the brushes
improperly spaced.
The fields were tested for polarity and found correct,
and the spacing of the brushes was also gone over. It
was while the armature winding was being examined to
determine the neutral position of the brushes, that the
unusual size of the air gap became apparent. Further
examination of the frame revealed the presence of shims
between the halves of the frame. The men who had done
the erecting then explained that after they had placed the
top half of the frame in position they noticed that there
was just sufficient room beween the top of the armature
and the bottom of the field coils to prevent rubbing while
the armature was turned, whereas the space between the
lower side of the armature and the bottom coils was quite
liberal. So they had cut up some sheet iron and inserted
it between the halves of the frame to make the air gap
on the top of the armature equal that at the bottom.
Here was the cause of the trouble.
A hoist was rigged from one of the roof trusses above
the generator, the bolts holding the halves of the frame
were taken out and the upper half was raised enough to
remove the offending shims. The halves were then tightly
bolted together and the air gap at the top and bottom
carefully gaged.
The bolts holding the frame to the base were then
loosened, and while the frame was steadied on all sides
a jack, placed as shown in the sketch, raised it enough
to insert sufficient shims to make the air gap equal at
top and bottom. This completed, the engine was started
again and the generator carried full load without further
trouble.
The next morning one of the men found the shims that
were sent with the machine and that should have been
placed between the base and frame in the first place,
securely tacked inside of the crates, out on the rubbish
heap.
P. Justus.
Cleveland, Ohio.
5H®Edlai»g| Power ©f a BoEG
In deciding the size of a bolt to be used it should be
assumed that it may be tightened by a helper who is in-
structed "to get it tight.'' To him this means that he is
to put his whole weight on the wrench, if not extend the
handle with a piece of pipe as long again.
To get a simple analogy to the action of a bolt clamping
two pieces of metal together, take two erasers and fasten
them together with a pair of light elastic bands, Fig. 1.
Just as soon as a pull is exerted on the erasers they come
apart enough to show light between them. The bands are
more elastic, so they yielded more than the erasers were
compressed by them in the first place. If very soft erasers
and heavy bands are used, then quite a pull can be exerted
on the erasers before any light will show, because they will
go back to their original thickness before the same pull
has stretched the elastics that much. This explains why it
is necessary to have joint packings with some give to them
to hold pressures. If the flanges and the bolts were of
the same material it would be theoretically impossible to
Rubber Band and Bolt Analogy
make up a tight joint without packing. Practically, it is
feasible because the pressure of the bolts is hardest close to
the bolt itself and the metal around the bolt hole is com-
pressed more than that further away and more than the
bolt is stretched.
Fig. 2 shows this more clearly. The, full lines show a
bolt and nut drawn up just tight enough to touch the two
flanges .4 and B. When the nut is drawn down hard the
flanges are each compressed to the dotted lines C and D
(exaggerated, of course) and the bolt itself is stretched
to the line E at the same time. No matter how tightly
the bolt is set up, it will continue to lengthen with addi-
r,20
POWER
Vol. 41, No. IS
tional pull. Now suppose that some pressure is brought
to bear to separate the two flanges. It will stretch the
bolt, but every particle that the bolt stretches, the flanges,
which were compressed, tend to go back to their original
thickness, so that there is a tight joint until the flanges
have got back where they started from; then the opening
is due to the additional stretch of the bolt. If an elastic
packing is inserted at F it will also keep the joint tight
until all the pressure on it due to the bolts is released. A
corrugated copper gasket acts in the same way, the corru-
gations, which are flattened out under pressure, coming
back when the pressure is relieved.
The longer the bolt, the more it will stretch under a
given pull. An eight-inch bolt will stretch four times
as much as a two-inch, but the packing has only so much
give in it, hence the decided advantage in using short
bolts where possible. The stretch also decreases as the
square of the diameter increases. A one-inch bolt will
hold four times as rigidly as a half -inch; not merely four
times as much in pounds, but with only one-fourth the
stretch for a given load.
There is, however, an advantage in a comparatively
long bolt in places where it can act as a relief. If a cyl-
inder is full of water the bolts may stretch enough to let
it out without further injury, but, aside from this emer-
gencv, the use of short, thick bolts is good practice.
E. H. Fish.
Worcester, Mass.
M sitslxan Ea ® try
To the articles under this title in the issue of Mar. 2,
page 310, and Apr. 6, page 482, much can be added and
still leave the matter of grouting unsettled in the minds
of many.
My belief is that at least an inch should be left between
the top of the foundation and the machine, and that the
Engine Frame-
Foundation Bolt-
Another System of Wedges
latter should he leveled by means of wedges placed as
shown on the illustration, one set on each side of every
foundation Bolt. When the leveling is complete, every
bolt should he tightened, so as to hold the machine tight-
ly against the wedges. The latter should all be left
permanently under the machine; and they will not slip
if they are made of cast iron with the surface left rough.
The grouting material may be either neat cement,
a mixture of sand and cement, sulphur, or lead. It
should be poured so that it will cover the top of the
foundation under the machine, and also cover the ends
of the wedges on the outside, as shown. If a mixture of
sand and cement is used it should be sufficiently thin
to flow easily. On account of the cost, lead is seldom used,
but it makes a very satisfactory job. Sulphur cannot be
used under machines where the heat will be so great as
to melt it.
J. E. POCHE.
New Orleans, La.
Tib© BonlletP Hsaspectloi? C©m\fe§ses
I have read the lurid description of a boiler inspector's
confession as printed on the Foreword page of the Mar.
9 Power. There is one item in it which causes me to
wonder how it ever "got by" the editorial force.
It is this : "Investigation showed that the fireman
had opened the blowoff valve, and before closing it rushed
away on a signal from the engineer. Before he returned
the explosion had happened. This knowledge relieved
my mind, but I had learned my lesson."
It is needless to tell you that an explosion might
possibly be caused by a sudden opening of a blowoff valve,
but if the valve had been open for any length of time
and left open, as in this case, the pressure would have
been gradually lowered and the boiler would not have
exploded.
Charles H. Garlics.
Pittsburgh, Penn.
[The chance of avoiding the rupture of a boiler de-
pends on the pressure being reduced to nearly zero before
the sheet or sheets become bursting hot. This may
happen with the blowoff valve open. But if two or
more boilers under pressure are connected to a common
header and one bursts a sheet because of low water, a
violent explosion would likely follow, blowoff open or not.
There was more than one boiler in the plant mentioned
in the foreword. — Editor.]
PtrnEssittnoias Sua Stesiinm Fapes
Correspondence published in the columns of Power
has quite frequently referred to the methods which have
been employed, with varying success, to cure pulsations
of steam pipes. The remedy most commonly suggested
is to place a receiver of moderate size in the steam pipe
near the engine.
I have designed and had built several receivers of
varying capacities, the smallest having a volume twice
that of the cylinder which it supplied. Others were much
larger, but not one was big enough to show any appreciable
diminution in the vibrations in the line. However, there
were advantages gained, which more than paid for the
work and expense of putting them in, such as drier steam,
higher initial pressure and a better steam distribution in
the engine cylinder.
But in no instance did I succeed in stopping the
vibrations entirely, without throttling the supply to the
receiver until the flow in the steam pipe was compara-
tively steady.
I have -een just one receiver placed in the steam line
to an engine that was large enough to stop the vibrations
entirely, and that one, I am sorry to say, I did not and
would not at that time dare to recommend.
Two boilers cross-connected by a drum riveted to the
shells supplied steam to a 14x42-inch Corliss engine
running 80 r.p.m. The four-inch steam pipe to the engine
was about forty feet long, and vibrated in spite of anchors
May 4, 191o
POWER
621
to such an extent that calking and reriveting the drum
nozzles was a serious matter.
The solution of the problem was finally left to the
engineer, who had the steam drum (which was 42 in.
dia. by 14 ft. long) taken from the boilers, set vertically
and connected direct to, and placed directly at the top of,
the throttle valve of the engine. There was no further
trouble from vibration or leaking rivets, and the initial
pressure in the cylinder was six pounds higher than before
the change was made.
That was the only receiver I ever saw large enough for
the purpose intended, and the only one I know of that
proved to be a complete solution of the pulsation nuisance.
F. L. Johnson.
New York City.
,Ka^HEa©
©sifted! wnHlr& (C©fflm<=
•©ssedl i^nir
The following scheme was worked out for turning over
and lubricating a 15x32x36-in. compound engine, tem-
porarily laid up, with compressed air instead of steam.
Reference to the illustration will explain the piping
arrangement.
All the fittings were in stock in the shop, and the job
was done at little cost. To start up, fill reservoir F with
Piping Abbangement for Compeesbed Air
light cylinder oil, open starting valve A, close receiver
valve B, then open valves G and D slightly. Regulate
the oil with valve E.
After the engine starts there is a fall of pressure in the
line from the compressor on account of wire drawing
in the small line. The receiver being closed off, the pres-
sure dues not drop rapidly and is higher at C than at A,
thereby causing the atomized oil to flow through nozzle
G into the engine.
C. II . Reed.
East Chicago, Ind.
TellepIhoEae IR©c©aves' G©iniiiii©<c&©etl
tt© C®iMp©irs
A telephone receiver lias been my constant friend
about the plant for the past twelve years, for various uses,
one of which is in
»W" sp ^
Ceiling
Telephone
Dry Cell Receiver
6erman.
Wire
connection with cali-
pering, especially the
work inside of engine
cylinders, as in Fig. 1.
The most convenient
way is to have the
two sides of the cali-
pers insulated from
each other. In Fig. 2,
where the work in
the lathe completes
the circuit, causing a
click in the receiver,
an ordinary pair may
be used with a cigar-
ette paper between
the work and one
side of the calipers.
This method is espe-
cially useful in align-
ing engines.
Use a slender ger-
man-silver wire for
the line, taking care
that it is insulated
from the ground if
an ordinary caliper
is used, or put a cig-
arette paper next to
the cylinder wall; then, with one side of the circuit
connected to the aligning wire and the other to the cali-
pers, a circuit will be completed when the two come in
Fig. 1. Aligning ax Engine
Fig. 2. Gaging Outside Work
contact. A click will be heard when a contact is so slight
that it cannot be seen or felt. Care should be taken not
to use too much battery power, as it is annoying to the
ear.
Amos J. Carr
Fort McKinlev, -Me.
Heating Surface of Superheaters — Experiments prove that
5 B.t.u. per sq.ft. of heating surface will be transferred to
steam for each degree of difference between it and the gases.
622
POWER
Vol. 41, No. 18
er Plaia&§
By R. E. Horton*
The writer and his assistants have frequent need to cal-
culate the cost of coal required by actual or hypothetical steam
plants under comparison with proposed hydraulic stations.
After a few laborious repetitions of computations going back
to fundamental factors, the office practice was standardizes
in the interest of general economy and capacity. A table pre-
pared is here given as of possible interest to others.
Computations were carried through and tabulated for the
yearly coal consumption in tons at a rate of 1 lb. per hp.-hr.
under various conditions. Now it is only necessary to ascer-
tain or estimate and combine (1) the simplest unit coal con-
sumption (per horsepower-hour, including allowance for
shrinkage and waste if any); (2) the average horsepower in
use when running; (3) the allowance for banking; (4) the
hours' use per day, and days per year.
FACTORS FOR CALCULATING AMOUNT OF STEAM COAL
REQUIRED PER HORSEPOWER-TEAR
Gross Tons, Net Tons,
2240 Lb. 2000 Lb.
310 365 310 365
Method of Operation Days Days Days Days
10 hr. per day, no banking 1.38 1.63 1.55 1.83
10 hr. per day plus J for banking 1.84 2.17 2.07 2.43
12 hr. per day, no banking 1.65 1.96 1.86 2.19
12 hr. per day plus i for banking 2.21 2.61 2.48 2.92
24 hr. per day, no banking 3.32 3.91 3.72 4.38
For example: A plant runs 10 hr. per day and 310 days
per year, produces 500 hp. average, uses 2% lb. per hp.-hr. of
steam coal, has I allowance for banking; coal costs $3.50 per
gross ton. From the table, the proper unit consumption per
horsepower year is 1.S4 gross tons.
Then,
2.5 X 1.84 X 500 X $3.50 = $7735 annual cost.
Sometimes it is necessary to know the tons of ash that
will have to be disposed of each year; then it is necessary
only to substitute the decimal percentage of ash in the coal
for the price per ton. For 15% ash the foregoing case shows
2.5X1.84X500X0.15 = 345 gross tons.
— "Engineering News."
By H. C. Dickinson and 1ST. S. Osborne
The term aneroid calorimeter is applied to a type of instru-
ment in which equalization of temperature is secured by
means of the thermal conductivity of copper instead of by
the convection of a stirred liquid. The calorimeter, consisting
of a thick-walled copper cylindrical vessel in the walls of
which are embedded a coil of resistance wire to supply heat
electrically and a platinum resistance coil for use as a ther-
mometer, has been found useful over a wide range of tempera-
tures and is applicable to a variety of problems.
For use at low temperatures the device is mounted in a
jacket surrounded by a bath of gasoline, the temperature
of which can be controlled thermostatically to within a few
thousandths of a degree at any temperature between — 55 and
+ 40° C. or can be changed rapidly in order to keep it the
same as that of the calorimeter when heat is being supplied
to the latter.
Differences in temperature between the surface of the
calorimeter and that of the jacket are measured by means
of multiple thermocouples which have 10 junctions distributed
over the surface of each, thus making it possible to apply
accurate corrections for thermal leakage between the calorim-
eter and the jacket even when the temperatures of both
are changing rapidly.
The platinum resistance coil (for use as a thermometer)
embedded in the calorimeter shows slight irregularities in
its behavior, probably due to the difference in expansion
between the platinum and the copper which surrounds it.
Uncertainties on this account, while in general negligible,
can be avoided by measuring the temperature of the outer
bath with a standard resistance thermometer, using the
thermocouples to measure the small difference, usually not
more than a few thousandths of a degree, between the
•Consulting Hydraulic Engineer, 57 No. Pine Ave., Albany,
N. Y.
tAbstract of a paper issued by the Bureau of Standards,
Department of Commerce, Washington, D. C.
calorimeter and the jacket. The thermometer could probably
be improved by changing the construction.
Results of a series of experiments (page 565, Apr. 27, 1915,
issue) give the constants of the resistance thermometer and
the heat capacity of the calorimeter, including a tin-lined
cell for use in determining the specific heat of ice and water
and the latent heat of fusion of ice.
A series of check experiments on the specific heat of water
shows the order of reproducibility of results which can be
obtained with this calorimeter to be 1 part in 2000. Measure-
ments made at temperatures between 0 and 40° C. gave results
which agree to within the limits of experimental accuracy
with the unpublished results of a long series of experiments
made in the usual form of stirred-water calorimeter. The
results are also in satisfactory agreement with the most prob-
able values deducible from the data of the most careful
investigations published by other observers.
IsaiE^ieiac© ©if Hsadlscsiftos' C©ia=
Ea©ctlaini8> Pipes*
By Thomas W. Morley
It is usually stated that one of the conditions for accuracy
in taking engine-indicator diagrams is that the connection
between the engine and the indicator should be short, direct
and of ample bore. The effect of bends, undue restrictions
and excessive length of indicator pipes would be to delay the
pressure change at the indicator, and hence to cause errors in
the diagram. This resistance can best be investigated ex-
perimentally, and the author, having been able to find only
very meager evidence as to the errors introduced by va-
rious connections, has conducted experiments to find out
whether the arrangements commonly used are responsible
for measurable errors.
A small steam engine was used to produce cycles of pres-
sure change typical of those occurring in steam-engine prac-
tice. The engine employed was vertical, with a 6%-in. cyl-
inder, 6-in. stroke, and ordinary slide-valve and link-motion
valve gear. The cutoff was kept at about 0.4 of the stroke
throughout the experiments.
Alternative indicator connections, long and short (Fig. 1),
were arranged, and pairs of diagrams taken through these
connections were compared. A and B denote the points at
B
■^"ig Bore
Q
Pig. 1. Alternative Indicator Connections
which the indicator cocks were coupled. The upper end of
the long pipe was, of course, suitably fixed.
At first, two similar indicators were placed at A and B,
but it was found that, although of the same make, they did
not give diagrams that admitted of convenient comparison.
In subsequent experiments only one was used, care being
taken that no change in the steam pressure or engine speed
took place while the indicator was transferred from one
position to the other.
Before the arrangement shown in Fig. 1 was adopted, pre-
liminary experiments were made, using next the engine a two-
way cock connection. The length between the upper and the
lower positions was the same as in Fig. 1.
♦From a paper presented before the Institution of Engi-
neers and Shipbuilders in Scotland.
May -A, 1915
POWER
623
The diagrams thus obtained differed widely. For example,
at 325 r.p.m. and a maximum pressure of 50 lb. per sq.in., the
mean effective pressures were 36.4 for the lower and 20.4 lb.
per sq.in. for the upper diagram. Even at 80 r.p.m. the differ-
ence was about 30 per cent. This was caused chiefly by the
small bore (ft in.) of the two-way cock. After It was bored
out to % in. the difference of the diagrams fell to 4 per cent,
at about 300 r.p.m. The use of the two-way cock still had
the drawback that, when the upper indicator was in use, the
pipe connection formed an appreciable addition to the cyl-
inder clearance volume. This in itself might affect the cycle
of pressure change in the engine and so account for the dif-
ference in the diagrams.
In the final arrangement, shown in Fig. 1, the pipe con-
nections to each indicator cock were constantly open to the
cylinder, so that the pressures in the whole system were al-
50-
40-
30-
20-
10
r
' 0
SHORT CONNECTION
j 50
I 40
ct 30
20-
10
LONG CONNECTION
Speed 190 R.p..-n.
Fig. 2. Indicator Diagrams from Alter-
native Connections
ways unaffected. Also, except for the short %-in. channel at
the cylinder wall, the connections to the indicators were of
uniform bore. Under these conditions a number of tests were
made with gage pressure up to 75 lb. per sq.in., and speeds
up to 280 r.p.m. Fig. 2 shows a typical pair of diagrams. The
differences between them are so small that they would be con-
cealed if one had been superposed on the other. The chief
visible difference in the diagrams was that those taken with
the long connection showed more waviness of outline, due, no
doubt, to the oscillations set up in the long pipe.
The following table shows the results of the experiments:
Mean
Maximum
Effective
Pressure
Pressure
Long Con-
Short Con
Speed
(from
nection
nection
Difference
of
Diagram)
P!
Pa
Pi— P2
Differ-
Engine
Lb. per
Lb. per
Lb. per
Lb. per
ence
R.p.m.
Sq.in.
Sq.in.
Sq.in.
Sq.in.
per Cent.
150
48
27.32
27.48
—0.16
—0.6
153
29
15.46
15.46
178
76
49.44
49.44
182
73
49.9
49.9
190
25
13.15
13.15
190
31
17.75
17.6
+ o'i.5
+ 0'.85
195
40
24.4
24.0
+ 0.4
+ 1.6
190
48
29.65
29.9
—0.25
—0.85
195
55
35.1
35.1
190
60
38.2
38.2
190
60
38.6
38.2
+ 0.4'
+ l'.i '
190
68
44.9
44.9
272
25.5
12.24
12.44
— o'i'
—1.6'
240
70
43.2
42.8
+ 0.4
+ 0.95
254
66
42.12
43.02
—0.9
—2.1
284
38.5
22.1
21.5
+ 0.6
+ 2.8
280
42
24.8
25.2
—0.4
— 1.6
275
47
27.7
28.1
—0.4
—1.4
280
53
32.6
32.3
+ 0.3
+ 0.95
270
62
37.9
37.8
+ 0.1
+ 0.25
The general conclusion to be drawn from the experiments
is that the influence of the connecting pipes does not subject
indicator diagrams to any appreciable error, except in ab-
normal cases. The difference of the mean effective pressures
was always small, in only two cases exceeding 2 per cent.; and
was in fact within the limit of probable error of the indicator
itself.
In the discussion following the delivery of the paper the
conclusions reached were questioned because the connection
at A in Fig 1 had two bends and the long pipe was in com-
munication with the cylinder while the indicator at A was in
use. In answer to the latter objection the author explained
that the arrangement used satisfied the real object of the
experiments, which was to compare the influence of long
and short pipes connected to a point at which a certain
pressure cycle took place. The indicator at A need not give
a faithful record of the cylinder pressures. Coming now to
the other objection, the indicators at A and B were separated
from the point where there was a constant cycle of pressures
by a bend and a short pipe in one case, and in the other by
an easier bend and a long pipe. Experiments other than those
described in the paper had been made on this engine with
connections of about the same length as that to A, but with
a different number of bends. No appreciable difference in
the results had been observed. It was therefore considered
that any difference in the influence of the two connections
would be due to their lengths alone and would not be
obscured by the bends.
Wlt&y Slh©*aEdl S^aclh TEaanags Se?
A leading machinery firm in Bombay expressed the opin-
ion that American boilers could not be successful in India, be-
cause of the steel used not being of the right quality as re-
quired by government testers. American manufacturers do
not follow Indian specifications, and offer openhearth steel in-
stead of basic. The market in India is for boilers built for
high pressure. The steel should not be too hard, but some-
what flexible. German boilers have sold well in India because
they are made of steel that expands well. Nearly all boilers
used in India are of Lancashire type. This firm states that it
imported a boiler from the United States' about 15 years ago
and still has it on hand, being unable to sell it. Boilers in
India are mostly used for cotton mills, ginning factories, etc.
— Henry D. Baker, U. S. Consul, Bombay.
aira©
sstt
Although the local newspapers reported that an accident
had taken place on Mar. 31 at the plant of the Boston Manu-
facturing Co., Waltham, Mass., the causes given varied from
a blowout of the cylinder head of a turbine engine to a tur-
bine explosion. Perhaps the most comprehensive was the
statement that the explosion in a 750-kw. engine blew up the
generator and badly damaged the boiler.
Further investigation has shown that at 5:45 p.m. on the
date mentioned, the exhaust casing on a 750-kw. G-E Curtis
turbine was blown to pieces, hurling through a window the
engineer, William Finley, who was standing near. Outside
of the turbine the damage was confined to the wrecking of
the engine-room windows and the dislodging of a few bricks
by pieces of the casing blown against them.
The accident is said to have been caused by the closing
of the exhaust valve before the throttle was closed, the re-
lief valve provided for such emergencies failing to operate.
Messrs. John S. Griggs, Jr., and David Moffat Meyers have
consolidated their consulting practices with offices at 110
West Fortieth St., New York City. Mr. Griggs was a member
of the consulting firm of Griggs & Holbrook, New York, and
has been in practice for the past twenty years. Mr. Meyers,
who is the author of the recently published book, "Prevent-
ing Losses in Factory Power Plants," was formerly mechani-
cal engineer for the United States Leather Co. The firm will
specialize in mechanical and electrical propositions for indus-
trial and other installations.
C. P. Poole, chief engineer of the Department of Me-
chanical Engineering of the City of Atlanta, Ga., has been
appointed a member of the International Jury of Award in the
Department of Machinery of the Panama International Expo-
sition. Mr. Poo'.e. who will be remembered as one of the
editors of "Power," has been for some time in charge of
what was known as the Department of Smoke and Gas In-
spection of Atlanta, and under his direction the activities of
the department have broadened out so as to make necessary
the reorganization indicated by the new title.
Stationary Engineers' Day at the Fair — The management
of the Panama-Pacific Exposition has designated Saturday,
May 29, as Stationary Engineers' Day. This will enable th-
delegates and guests of the California State Association of
624
r 0 W E R
Vol. 41, No. 18
the N. A. S. E. to enjoy that day at the Fair, since the annual
convention of this association will be held in San Francisco
on May 27 and 2S.
The Fifteenth Annual Summer Session of the College of
Engineering of the University of Wisconsin will be held at
Madison during the six weeks' period beginning June 21.
Special courses will be given in electrical, steam and hydrau-
lic engineering, gas engines, machine design, mechanical
drawing, mechanics, shopwork and surveying. Further in-
formation may be obtained from F. E. Turneaure, Dean,
Madison, Wis.
The Internntionnl Engineering Cousress which is to be
held in San Francisco in September will issue in Vol. IV of
its transactions the papers presented on "Railways and Rail-
way Engineering." The field treated will cover the relation
of railways to social development, present status of railways,
economic factors governing building of new lines, location,
physical characteristics of road including track and roadbed,
bridges, tunnels, terminals, construction methods, signals,
road equipment, including motive power other than electric,
rolling stock, floating equipment, and electric motive power.
W. A. Cattell, 417 Foxcroft Bldg., San Francisco, secretary of
the Congress, will furnish particulars regarding membership
and the securing of the transactions to those interested.
These transactions will include nine or ten volumes, covering
the various fields of engineering.
HEW FUJIBIUCATHOB^
MECHANICAL WORLD POCKETBOOK, twenty-eighth issue.
Norman Remington Co., Baltimore, Md„ American agents.
Size, 4x6 inches; 330 pages. Price, 50 cents.
Besides the usual data given in previous editions of this
well-known low-priced handbook, this issue contains an ex-
tended and rewritten section on toothed gearing and a more
lengthy section dealing "with structural iron and steel work.
Also, new sections on limit gages and on the cost of power
have been added.
ADVANCED ELECTRICITY AND MAGNETISM. By W. S.
Franklin and Barrv MacNutt. Published bv the Mac-
millan Co., New York. Cloth, 5y2xSy2 inches; 300 pages;
217 illustrations. Price, $2.
This book is designed for students in colleges and technical
schools. The subject matter deals with the elementary theory
of magnetism and with advanced principles of the magnetic
measurement of current, electromagnetic induction, electro-
statics and electric waves. An outline is given of the elec-
tron theory and of its application to the vacuum tube and the
electric arc. The historical development of the theory is en-
tirely, and the mathematical largely, omitted, the treatment
being confined to concrete presentations of a few principles.
A number of problems (with answers) are given at the ends
of the chapters.
HEATING AND VENTILATING BUILDINGS. By R. C. Car-
penter. Published by John Wiley & Sons, Inc.. New York.
Cloth, 6x9 in.; 59S pages; 290 illustrations. $3.50.
Professor Carpenter's "well-known treatise, now published
in its sixth edition, is a manual for heating engineers and
architects. It gives general methods of design and construc-
tion as well as the elementary principles applying to heating
and ventilating apparatus. While the previous edition has
been rearranged to a considerable extent, the additions in the
sixth edition consist mainly of a chapter on air conditioning
and of abstracts of heating and ventilating laws. The deter-
mination and regulation of humidity and the methods of puri-
fying air are broadly described. Abstracts of the laws relat-
ing to the heating and ventilation of schoolhouses and public
buildings in 17 states are given. The book has the disad-
vantages common to most technical treatises in which an
attempt is made to keep them up to date by publishing new
editions. Even with the best of intentions it is difficult to
thoroughly revise an old book. This is evidenced in the
present instance by the many results of tests and investiga-
tions made in the late 80's and early 90's. This material
was adequate when the book was first published in 1S95, but
at the present time, although perhaps of historical value, is
surely not indicative of the state of the industry. Another
disadvantage is the difficulty in adding new material without
affecting the unity of the original treatment. For example the
present volume has two sets of sections numbered from 56 to
72 inclusive. Of course this is caused by carelessness in re-
vision, but it goes to show a minor trouble experienced in
forcing the original text to assume a new and different
form.
E. Keeler Co., Williamsport, Penn. Catalog. Return tubu-
lar boilers. Illustrated, 46 pp., 7V&X10V& in.
Armstrong Cork Co., Pittsburgh, Penn. Pamphlet. "Good
Furnaces Made Better." Illustrated, 20 pp., 3^x6 in.
The DuBois Machine Shop, 118 Hudson Ave., Albany, N. Y.
Booklet. Randerson automatic piston ring. Illustrated, 3x6 in.
Otis Elevator Co., Eleventh Ave. and 26th St., New York.
Catalog. Gravity spiral conveyors. Illustrated, 56 pp., 6x9 in.
B. F. Sturtevant Co., Hyde Park, Boston, Mass. Bulletin
No. 214. Turbo-undergrate blower. Illustrated, 24 pp., 6V4x9
in.
Allis-Chalmers Mfg. Co., Milwaukee, Wis. Bulletin No.
lf>32. Allis-Chalmers oil engines, Diesel tvpe. Illustrated, 16
pp., 8x10 V4 in.
The D. T. Williams Valve Co., Cincinnati, Ohio. Catalog No.
10. Valves, steam cocks, water gages, lubricators, steam traps,
etc. Illustrated, 320 pp., 5%x8 in.
American Blower Co., Detroit, Mich. Bulletin No. 24 —
Series 4. Sirocco heating, ventilating, cooling and purifying
system. Illustrated, 32 pp., S'ixll in.
Gas Engine & Power Co. and Chas. L. Seabury & Co.,
Cons.. Morris Heights, N. Y. Catalog No. 10. Seabury safety
water tube boilers. Illustrated, 46 pp., 6x9 in.
Richardson-Phenix Co., Milwaukee, Wis. Bulletin No. 10.
Peterson power plant oil filter and accessory apparatus for
central oiling systems. Illustrated, 32 pp., S^xll in.
General Electric Co., Schenectady, N. Y. Bulletin No. 48,904.
Electric arc welding. Illustrated, 10 pp., 8xl0y2 in. Bulletin
No. 48,905. Arc welding apparatus. Illustrated, 6 pp., Sxloy,
in.
Spray Engineering Co., 93 Federal St., Boston, Mass. Bul-
letin No. 101. Sprays for Cooling Conde„is;ng Water. Il-
lustrated, 14 pp., 6x9 in. Bulletin No. 151. Washing and
Cooling Air for Steam Turbine Generators. Illustrated. S pp..
6x9 in.
Positions Wanted, 3 ceDts a word, minimum charge 50c. an insertion, in advance
Positions Open, (Civil Service Examinations). Employment Agencies (Labor
charge, S1.00 an insertion.
Count three words for keyed address care of New York; four for Chicago =
Abbreviated words or symbols count as full words.
Copy should reach us not later than If) A.M. Tuesday for ensuing week's issue =
Answers addressed to our care. Tenth Ave. at Thirty-sixth Street. New York or =
1144 Monadnock Block, Chicago will be forwarded (excepting circulars or =
similar literature).
No information given by us regarding keyed advertiser's name or address. |
Original letters of recommendation or other papers of value should not be in- I
closed to unknown correspondents. Send copies.
Advertisements calling for bids, S3. 60 an inch per insertion. p I
p©§hth©h§ ofeh
MASTER MECHANIC for rolling mill. P. 487, Power.
A CENTRIFUGAL PUMP DESIGNER with experience in
designing high-speed pumps of small and medium sizes for
high- and low-head service; applicants must state fully their
experience, age and salary expected. P. 491, Power.
FOSSTHOMS WABJTED
CHIEF ENGINEER, employed in central station; seven
years' experience with engines, turbines, dvnamos, boilers;
married; age 30. P. W. 4SS, Powei, Chicago.
ENGINEER, competent to take full charge of industrial
power plant; familiar with usual types of steam and electric
equipment, refrigerating machinery, elevators, etc.; first-class
references; available at once. P. W. 493, Power.
MAN of wide experience in power-plant, light-plant and
water-works management, construction, installation and
operation desires position; Middle West or West preferred;
combustion engineer and all-round efficiency man; prefer to
act as chief engineer or superintendent of power for company
controlling several plants who wants better results; or would
consider manager's position; at present employed at $2500 per
year; nine years with present company; 34 years old; change
necessary on account of wife's health; anything reasonable
considered; no intoxicants, narcotics or profanity; references
given and required. P. W. 484, Power, Chicago.
AGENTS AND SALESMEN
WANTED — Thoroughly competent steam specialty sales-
man; one that can sell high-grade goods. W. 120, Power.
Chicago.
SALESMAN selling engineers' supplies wants connection
with reliable concern; Rhode Island, southern Massachusetts',
salary and commission. W. 495, Power.
X\Q%
POWER
ill \
^ :::::: ,*
^
Vol. H
NEW YOKK, .MAY 11. 191!
No. l!i
Milestoimei
626
p <j w E 1;
Vol. 41, No. 19
)lt(
By Charles H. Bhomlky
SYNOPSIS — The lecture is intended for operat-
ing men. II explains in simple words and diagrams
how a turbine makes use of the energy in the steam,
what impulse and reaction are as applied to tur-
bines, what staging is and why il is necessary; tells
in a general way what to do when starting and
stopping, and emphasizes the importance of careful
attention to the oiling system and the blade clear-
ances.
To understand the turbine it is essential that one be
acquainted with tin- tonus of energy of which it makes
use. Energy is of two kinds, potential and kinetic. The
former is rest energy, or energy capable of manifesting
itself by reason of position, as tin' weight of a pile driver
before it i> released to descend, as steam under pressure,
confined and ready to move on being released, or as a
spring compressed or elongated. Things have potential
energy by reason of their position or by the state of ar-
rangement of their molecules. Kinetic energy is energy
of motion, as the energy in a falling weight, a moving
train, a jet of water or steam. When kinetic energy i-
mentioned velocity is always implied.
The reciprocating engine uses the potential energy in
the steam, for the energy is given up by the steam as it
expands, pushing tin.' piston ahead of it. The potential
energy is converted directly into mechanical work. A
turbine changes the potential energy into kinetic before
it does work with the steam. It may make the change
complete before the steam enters the moving parts of
the turbine, or it may make it in installments — in stages.
Difference between Impulse and Reaction
This brings us to the subject id' impulse and reaction,
that is, to the two ways in which the energy is extracted
from the steam at the turbine blades. Impulse action,
when related to turbines, means to force, to impel, by im-
pact, as when you wash the floor with water from a hose.
The blow, tin' impact, with which the water strikes the
dirt drives it ahead. In an impulse turbine the steam does
the same thing to the wheel. Examples of impulse and
reaction are shown in Pig. 1. A good illustration of re-
action is the common whirling lawn sprinkler shown.
The water under pressure flows from the nozzles, causing
them to more in a direction opposite that taken by tin
water. Reaction as applied to a turbine wheel may be ex-
plained as a backward push as the steam passing through
the nozzles reduces its pressure. The wheels of reaction
turbines have blades that form nozzles, and the pressure
at the inlet side is greater than that at the outlet. This
pressure difference in the wheel is what causes it to revolve.
In an impulse turbine the pressure is the same on both
sides of the wheel. The two kinds of blading, impulse and
reaction, are shown in Fig. 2.
•From a lecture before the Modern Science Club, Brook-
lyn, N. \.
Keeping in mind the two forms of energy, it is well
now to undcrMand what is meant by staging as applied to
turbines. One of the definitions of stage given in Web-
ster's Dictionary admirably suits our needs:
Stogie: "A distance between two places of rest on a
road; hence, a degree of advance in a journey."
Steam at high pressure enters the turbine, passes
through it and comes out with most of its energy ex-
tracted. The steam is on a journey, the turbine is the
load and the intervals between stages are the places of rest
on the way. I f the steam passes through the turbine from
the high to the low pressure all at once, if it does not
rest, as it were, between the two points, if there is but one
distance between the beginning and the end of the journey
(expansion), then that turbine is a single-stage machine.
If the steam rests more than once on the way, then the
turbine through which it passes is a multi-stage machine.
In Fig. :!, left, the pressure due to the total head is ap-
plied to the wheel. It is a single-stage machine. At the
right the total head is divided into four parts. The machine
is a multi-stage one. Each wheel has but one-fourth of the
total pressure applied to it. The velocity of the water at the
nozzles is less in the multi-stage than in the single-stage
machine and therefore permits of running the wheels
slower, although about the same amount of energy is
taken out of the jets in both cases. The advantages of di-
viding the pressure or velocity drop in this way in steam
turbines will be taken up presently. A stage in a turbine
may also be considered as a compartment for a wheel
where the steam decreases either its pressure or velocitv.
as shown in Fig. 1.
By properly graduating the cross-section of a nozzle you
can expand steam from one pressure to another, making
the drop between inlet and outlet as much as desired. Such
nozzles form the communicating passages between the
stationary and moving blades or between the stages or
compartments of a turbine. It is in this way that the pres-
sure and velocity are controlled in the wheels and the
stages, or wheel compartments.
Single- and Multi-Staging
Primarily, it is the great amount of energy liberated
by the expansion id' a comparatively small weight of steam
that makes staging in turbines necessary. A pound
(weight) of steam at 150 lb. pressure expanded in a per-
fei i nozzle to I lh. absolute (28 in. vacuum) gives up 325
R.t.u., which is equivalent to 325 X 778 = 252,850 ft.-
lb. of energy.
In expanding between these two pressures in one jump
the steam would attain a velocity id' a little over 4000 ft.
per second, or more than 2700 miles an hour. Nearly all
the energy (potential) that was in the steam before its
expansion is present after expansion in the kinetic (ve-
locity) form. To convert the kinetic into mechanical
energy the steam must be brought to rest by the turbine
wheel or rotor.
In an impulse turbine expansion of the steam occurs
only in the nozzles, or stationary blades, and in a single-
May 11, 1915
P U \V E E
627
Fig. 1. Examples of Impulse and Reaction
628
pow b 1:
Vol. 11, No. 19
stage machine, like the De Laval, Fig. i. for example,
the steam is fully expanded in the nozzles and therefore it
strikes the wheel at the enormous velocity of about 1000
ft. pei sei .
If the glass in Fig. 1 were moved in the same direc-
tion as the jet. or stream, of water and at one-half the
velocity of the stream, the water would just flow over the
side of the glass and all the energy in the jet would be
extracted. To tiring the steam to rest the wheel must run
at half the speed of the steam jet, or, for the single-wheel
turbine the peripheral speed of the wheel must be 2000
ft. per sec. Under these conditions the steam would leave
the wheel with just enough velocity to force itself away
from it. To produce this effect, i.e., to get the steam to
leave the bucket with no velocity, means using an enor-
mous wheel if a fairly low number of revolutions per min-
ute is desired, or. if a small wheel is used it must run at
an extremely high speed. Mechanical difficulties do not
permit of obtaining slow wheel speeds, for the wheel would
be too large (61 ft. diameter for GOO r.p.m.), so small
wheels running as high as :!0.000 r.p.m. are used in the
small-sized single-stage Pe Laval machines. (4ears are
used to reduce the speed to accommodate the driven ma-
chine. About 500 hp. is the capacity limit commercially
for a single-stage turbine.
Suppose all the velocity were not extracted by the wheel.
Then there would still be energy in the steam which might
be applied to another wheel and from the second to a third
and then to a fourth, all on the same shaft; and so on un-
til the pressure and velocity, and therefore the energy,
were zero. With a suitable number and arrangement of
wheels, nozzles and diaphragms (partitions forming the
stage compartments) the pressure and velocity changes
through the turbine may be controlled as desired. On
page 630 the diagrams, Figs. 5, 6, 7, 8, and 9, show
the different methods of extracting the energy from the
steam. The page will make a good insert for your note-
book. The tendency here and abroad is toward the wider
adoption of the "composite" design, i.e., velocity staging in
the high-pressure end and pressure staging in the low-
pressure end. A good illustration of this design is shown
in Fig. 9. Note the large drop in pressure in the impulse,
or velocity, chamber.
For a simple and entertaining explanation of steam
speeds and bucket speeds the reader is referred to the ar-
ticle by F. R. Low in last week's issue.
Starting and Stopping
When steam is turned into an engine it fills the space
back of the piston and in some cases the whole cylinder.
warming it uniformly and therefore minimizing strains
due to expansion. In most large turbines steam would not
be admitted around the whole circumference of the rotor
when the turbine was standing still unless special "warm-
ing pipes" were provided, as they sometimes are. So, to
warm a turbine, large or small, it is always best to have
all drains open and admit steam quickly enough to revolve
the turbine, letting it warm while running. If allowed
to stand still with warming steam on, the .-team will flow
along through the blading in a path, thus creating unequal
expansion of. and imposing objectionable strains in. the
rotor and casing. If the sealing-gland water is admitted
under pressure created by a pump, a tank or from the city
mains the turbine may be started condensing. If the gland-
seal water pressure is created by an impeller on the shaft
whose speed is that of the rotor, and there is no means of
scaling, then it is best to start noncondensing, putting the
condenser in service slowly after the turbine has attained
normal speed. In this way excessive amounts of air are
not carried into the machine. Turbines using steam-sealed
carbon-ring packing may be started condensing. It is
^\
Guide
Blades
Guide
Blades
REACTION BLADING
impulse blading
Chose Sei hons of Turbine Blades
Fig. 2. Imitl.se and Reaction Blading fob Turbines
v 1 general practice to shut down the condenser quickly
when stopping a turbine, for with some designs of gland
seals cold air would be drawn in when the steam was shut
off the machine if the condenser were left running, expos-
ing the rotor to distortion, which is objectionable.
Turbine Lubrication
Lubricating oil for large turbines, vertical or horizontal,
is supplied under pressure, the oil being forced by at least
two pumps, one driven by the turbine shaft, the other a
small, usually duplex, steam-driven pump. The latter
should I"1 started before the turbine is turned oxer to in-
May 11, 1915
P 0 W E R
629
sure good circulation for starting. When the turbine
is up to about normal speed the shaft-driven pump goes
into useful service and the steam-driven one may be
stopped. When shutting down, start the steam-driven
pump and let it run until the turbine stops. Sometimes
an elevated tank is used for supplying oil for starting
and stopping. The aim always should be to have the oil
and the oil-cooling water circulating before starting, and
continue flowing without cessation until the machine is at
a standstill. This is important.
The importance of a continuous oil supply to the bear
ings of a turbine is much greater than for a reciprocating
engine. This is because of the small clearances between
the stationary and rotating parts, because the speed is
much greater, and because the bearings are near the high-
temperature parts of the machine. All of these conditions
make a hot bearing much to be feared. Should the babbitt
or white metal in the bearings reach the melting point and
become plastic, the rotor will drop, owing to its weight,
and if not stopped in time many blades may he ripped oil,
and if it is a single-flow Parson --type machine the dummy
pistons and rings will be seriously damaged. The oil
circulation system — the reservoir, the pumps, the filter,
Fig. o. Instead of Applying the Total Pressure
ox One Wheel (One Stage), the Multi-
stage Machine Uses .Moke Than One
Wheel, Applying Only Part of the
Total Pressure on Each
the cooler, the pipe lines and the oil grooves — must he
given the most thorough attention.
As the oil consumption of turbines is low on account
of no oil getting in contact with steam or condensate, and
because of the circulation system, it is good engineering to
use a high-grade mineral oil, free from acids, thickeners,
tarry, slimy and saponifiable substances. The General
Electric Co. recommends that the flash-point, open-cup
test, should be below :i:l I det;-. P. and that the viscosity
should not be more than 228 sec. at 10 deg. 0. (101 P.),
as shown by a Saybolil viscosimeter, which is the kind used
by the Standard Oil Co.
(Jood general instructions for starting are: Have all
glands sealed at about 5 to 10 lb. pressure ; the atmospheric
or free exhaust valve is usually water-sealed. Have it
scaled. Have the oil circulating through the bearings.
If the turbine is a Curtis vertical, start the step-bearing
and valve-gear pumps ami maintain the necessary pres
Condenser Pressure
Fig. 4. Turbine Staging Conceived of as Com-
partments
Note that the openings between compartments increase
from the high- to the low-pressure end to pass the increas-
ing volume of steam.
sure — 750 to 1500 lb. on the bearing, depending on the
size of the turbine. Now start the dry-air pump, the hot-
well pump and the circulating pump. Usually, there is a
pipe leading from the condenser to the top of the circulat-
ing pump. Open the valve in this line (priming line),
as it allows air to be exhausted from the pump and suc-
tion and assists the pump in picking up its water. Slow-
ly bring all pumps up to speed. If there are drains for the
different stages of the turbine, open them. Now start the
main turbine slowly, increasing- the speed and letting the
governor get control.
Look around to make sure that the oil and water cir-
culation is good, that the circulating-water pressure and
step-bearing oil or water pressure are right, and that the
governor has control. Next close the circulating-pump
priming valve. Now put on the load. If there are steam-
sealed glands, shut off the steam to the high-pressure pack-
ing, for the pressure in the first stage prevents air getting
in. It may be necessary to regulate the pressure on the
low-pressure packing. Now close the drains of the stages.
The gear may then be oiled. The main turbine may vi-
brate considerably while being brought up to speed. Do
not be alarmed at this. When this occurs admit a little
more steam quickly to get tin- rotor above the "critical
speed," when the vibration will ordinarily cease. Acquire
the habit of shutting down the turbine by tripping the
emergency governor, which should automatic-ally operate
at 10 to 12 per cent, above normal speed.
Sometimes, just, after the machine gets its load it will
lag, i.e., be slow or "jerky" with its speed. Frequently,
this is due to the pilot valve for the main steam-aeknission
valve sticking, owing to carbon which has collected on the
stem. Pour on some kerosene for the time being, but (lean
the valves as soon as the unit is stopped. In case of any
unusual disturbances inside the casing, as the noise due
to rubbing of the blades, trip the emergency governor
to avoid serious damage or. perhaps, a wreck.
For best economy the clearances between the tips of the
blades and the casing and between the sides of the station-
630
P U \Y B R
Vol. 41, No. 19
PRESSURE AND VELOCITY CHANGES IN
STEAM TURBINES
Fig. 5. Pressure and velocity changes as they occur
in single-stage turbines, which type most small tur-
bines represent. Notice that the pressure drops com-
pletely in the nozzle and the velocity completely in the
moving wheel.
Fig. 6. Multi-pressure, multi-velocity staging. The
pressure in each stage is constant, but is dropped in a
nozzle before each stage. Large Curtis vertical machines
use the energy in this way. The turbine is an impulse
machine.
Fig. 7. Pressure and velocity changes as carried out
in the multicellular (impulse) type. This kind of
turbine is a multi-pressure, single-velocity machine, of
which some of the De Laval, Zoelly, Kerr. Rateau and
others are representative types.
Fig. 8. Shows how the "pure" reaction, or Parsons,
types of turbines use the energy in the steam. The pres-
sure is dropped very gradually through many rows of
blades, there being no large increase in velocity any-
where in the machine.
Fig. 9. Pressure and velocity changes as made in the
composite design, with velocity staging in the high-pres-
sure element and pressure staging in the low-pressure
element. The diagram relates particularly to the West-
inghouse double-flow turbine. -Many turbines here and
abroad are of the composite design.
May 1
191!
() W E i;
631
ary and the moving blades, and between the dummy pis-
tons and their rings, if a single-flow Parsons-type ma-
chine, must be small, a comparatively few thousandths of
an inch in all cases. Because of the high speeds at which
turbines run and because of tire small clearances, it is es-
sential that the rotor he in mechanical balance. Adjust
ing clearances ami putting a rotor in balance are jobs re-
quiring skill carefully applied. Time does not permit of
taking up these subjects in this lecture, though they arc
of much interest and importance to t he operating engineer.
[). Williams
SYNOPSIS — This large central phial uses econo-
mizers. The gates in the hopper millets of the
coal bunker are opened and closed by emu pressed
air, the control being in the hands of the coal-
telpher operator. Delray-type boilers are used.
Stoker and draft controls are interesting.
In designing the new, or East Fifty-third Street Cleve-
land municipal lighting plant, F. W. Ballard has used
motor-driven auxiliaries throughout, but has provided a
steam-driven boiler feeder and a turbo-exciter for emer-
gency service. This plan has simplified the piping systems
Shore l'.li. and a siding from which two spurs extend over
the coal bunker. The height available at this point was
not sufficient to permit of placing the bunkers above the
boilers without excavating to a considerable depth below
the water level of the lake. As the result of this con-
dition, the station practically consists of three parallel
structures — the coal-hunker section on the east, the elec-
trical section on the west and the boiler section in the
center.
The bottom of the hunker consists of 40 steel-plate hop-
pers, each provideel with a gate opened and closed by a
compressed-air cylinder whose operation is controlled by
the coal-telpher operator. The telphers run on transverse
Fio. 1. Aisle below Bunkeb Showing Hopper Bottom with Air-Operated Gates fob Loading Telpher
and eliminated the exhaust steam feed-water heater.
Large-sized, high firebox boilers are used, with induced-
and forced-draft fans, and the waste gases from the boiler
are passed through an economizer for heating the \'tlvt\
water.
The plant is on the shore of Lake Erie at the foot of a
steep bluff on the top of which are the tracks of the Lake
tracks below the cast section of the hunker and are car-
ried by a transfer crane below the west section, an arrange-
ment which permits coal to he drawn from any section of
the bunker and delivered to any boiler. Each telpher is
provided with a weighing hopper, and the operator on
each watch turns in a report of the amount of coal and the
time at which coal was delivered to each boiler.
632
row EE
Vol. 11, No. 19
The present installation comprises five Delray-type
Stirling boilers, each fired by two six-retort Taylor stok-
Exceptionally large structural-steel coal hoppers are
provided for each stoker, from which the coal flow- I y
gravity to the grates. The central space between the two
stokers is closed by dump plates, from which the ashes and
clinker are dropped into an ashes hopper. An industrial
track is laid in the concrete floor of the boiler-room base-
Fig. 2. Pibing Aisle. Xote Lakgb Stokeb Hoppers
merit, and upon this are operated steel side-dump ash cars
and a storage-battery-operated electric ash ear. These
cars are used to carry the ashes outside of the building to
a point where they can be used in filling in and extending
the city property to the harbor line established by the
States engineers.
The lire area below the boiler is approximately 200 sq.ft.,
for an average height of about in ft. to the bottom of the
two mud drums. From this height up the combustion
chamber i- shaped like a wedge, point up, with a height of
nearly 20 ft., the two sloping sides being formed by the
of the iir-1 pass. This arrangement gives ample
for the flame to form, and the combustible gases are
not chilled below the igniting temperature by the eom-
aratively cold tubes of the boiler. In operation the in-
tcrior of this chamber shows a clear white flame at the
lower portion and transparent orange above. As one
pound of gas occupying a unit volume in the blast mam
will oci olumes in the combustio! chamber and
one an 1 one-quarter volumes at the uptake, there are some
reasons for providing space for this expansion. The -,
ond pass of the gases brings them in contact with the
superheater tubes, and at the end of the third pass they
flow into an overhead smoke flue. On test the gas tem-
peratures at this point ranged from 510 deg. F. at I'm;
pel cent, rating to 832 deg. F. at 273 per cent, rated lead.
In this plant the stokers ami the forced-draft fans are
separate motors. The speed of the fan motors
ned by controllers operated by changes in boiler
sure, while that of the stoker motors is controlled by
changes in blasi pressure. The small bouses which pro-
tect these speed controllers are shown at the left si.! ol
the aisle in Fig. "J. Additional control of the draft is sup-
plied by the induced-draft fans, •which are operated by
motors with manual speed control by means of which the
boiler tenders can keep the combustion chamber close t"
cir slightly above atmospheric pressure. This method of
operation obviates any tendency of air to seep into the
settings through the brickwork or around the cleanouf
doors and is particularly desirable when it becomes i
sarv to bar the fires, as there is no tendency to either
chill the furnace or burn the firemen. In practice this
plan seems to work out well.
From the boilers the waste erases are carried to the
i omizers and the stack by sheet-steel fines. The stack
provided is not designed to supply draft, and for that
PRINCIPAL STEAM GENERATING EQUIPMENT OF EAST 53RD STREET STATION, CLEVELAND MUNICIPAL ELECTRIC LIGHT PLANT
No. Equipment Kind Size Use Operating Conditions Maker
5 Boilers Stirling. Delrav 10.134 sq.ft. heating 225 to 275 lb. pressure; 125 deg. to 150 deg. F.
tvpe ' surface. Steam generation . superheat Babcock A: rW llcox Co
10 Stokers Taylor underfeed 6 retort . Under boilers From standby to 2, 5 per cent, boiler rating American Engineering Co.
G Motors Variable speed. 10-hp Stoker drive .. . 725 to 1125 r.p.m., 220 volts, 37.5 amp., direct
current Diehl Mfg. Co.
220-volt Cutter-Hammer Mfg. Co.
t by air duct pressure Mason Regulator Co.
B. L. Sturtcvant Co.
6 Speed controllers Pressure controlled 10-hp Stoker driv
6 Speed controllers Stoker driv.
Operators
5 Fans Multivanc 36,000 cu.ft. ail pe-
rnio Forced draft 7 in of water pressure
5 Fan motors.... Variable speed . 75-hp .... Forced draft ... 600 to 730 r.p.m.. 220 volts. 2s2 amp., direct cur-
rent Allis-Chalmers Mfg. Co.
5 Speed controllers Pres- .- 75-hp Forced draft fans. 220-voit Cutter-Hammer Mfg. Co.
5 Speed controllers . . . Forced draft fans Controlled by boder pressure Mason Regulator Co.
2 Fami. Steel housed I6x7-ft Induced draft. . Belted to motors; 70 to 210 r.p.m.: 101,000 to
cu.ft. per min , 1 in. draft at econo-
mizer inlet Green Fuel Economizer Co.
1 Fan motor Induction, variable 695 r.p m; 3-phase; stator 2300 volts, 47.5 amp.;
speed 200-hp Induced draft . otor479 volts. 207 amp. . illis-Chalmers Mfg. Co
1 Fan motor . Vari 200-hp Induced draft 540 to 740 r.p.m., 220 volts, 745 amp.. Alus-Chalmers Mfg. Co.
1 Speed contr 11 •• Manual 200-hp Induced draft . Cutter-Hammer Mfg Co
i Economizer . 2 -■,'ti<>ns in multiple,
27,000 sq.ft. heating
Feed water heater Waste gases from boilers. . . ... UP
1 Scraper motor.. Induction 3-hp Economizer soot
scrapers 1200 l
1 Scraper motor.. Induction 7.5-hp Economizer soot
scrapers 1200 r.p.m.
1 Chimney Concrete lined 13-ft diameter, 150 ft. Removal of wasti
high gases Induced draft.
Fuel Economizer Co
GO-cycle, 220 volts General Electric Co
ral Concrete Cons. Co.
.May 11, 1915
]'<> W E i;
63:5
reason has been made only of a height sufficient to carry
the waste gases up to a point a1 which they will not be-
come a nuisance to neighboring property. The two in-
duced-draft fans are close to the base of the stack ami dis-
charge into it, each being of a capacity sufficient to handle
all the load.
The normal operation of this plant provides for the
heating of the feed water by the economizers. This in-
stallation is divided in two sections, each containing 824
twelve-foot tubes, the total heating surface in both sec-
tions being 27,000 sq.ft. Each section of the economizer
be operated independently or may he cut out by
dampers. A bypass flue is also provided to lead the waste
gases direct to the induced-draft fans.
SI> \( !E WT> VOLUMETRIC DATA i >V THE STATION
Turbine room and switch gallery 8100 sq.fl
Sq.ft. per normal kw. 0 54
Sq.ft. per maximum kw 0 :;'■
Boiler room 9230 sq.ft.
Sq.ft. per boiler hp. installed ...1.82
Sq.ft. per boiler hp. (6 boilers) 1 52
Sq.ft. per kw. normal. . 0.615
Sq.ft. per kw. maximum 0 lie
Boiler room plus bunker space , , 15,330 sq.ft.
Sq.ft. per boiler hp. installed 3 112
Sq.ft. per boiler hp. (6 boilers) . _' ".-'
Sq.ft. per kw. normal 1 .024
Sq.ft. per kw. maximum 0 682
Total ground area of station 25.300 sq.ft.
Sq.ft. per kw. normal. 1 68
Sq.ft. per kw. maximum 1.13
Volume turbine room and switrh gallery 500,000 cu ft
Cu.fi , per kw. normal 3.3 33
Cu.f t. per kw. maximum 22 . 22
Volume boiler room 567.000 cu.ft.
Cu.ft. per boiler hp. installed 11 . 19
Cu.ft. per boiler hp. (0 boilers) ... 9.34
Cu.ft. per kw. normal [7.80
Cu.ft. per kw. maximum 25 20
Volume boiler room plus bunker space 841,000 cu.ft.
Cu.ft. per boiler hp. installed 16 55
Cu.ft. per boiler hp. (6 boUei I 13 35
Cu.ft. per kw. normal. . . . 56 l1'
Cu.ft. per kw. maximum :7 in
Volume of building 1.420.000 cu.ft.
Cu.ft. per kw. normal. . . 95 00
Cu.ft. per kw. maximum 03. 20
The present installation comprises:
3 main generating units, normal rating 5000 kw each
maximum rating 7500 kw. each
Five boilers, each having 10,134 sq.ft. heating surface. Space has been left for a
sixth boiler.
Coal storage capacity in bunker 3400 tons
Coal storage per boiler hp . ..1114 1b.
Coal -torago per kw. normal. . 454 lb.
Coal storage per kw. maximum . 304 lb.
The total length of the economizer is 55 ft. ? in. and it
is so designed that the free area between the tubes is
reduced as the gases become cooler.
I I '< INOMIZER DATA
Free Total
Area Free Area
Tubes Tubes Total Each Both
Number Number per per Number Section, Sections,
Sections Headers Header Section Tubes sq.ft. sq.ft.
2 16 6 96 192 56,7 113.4
2 16 8 128 256 49 9 99.8
2 80 10 600 1200 42.9 85.8
2 92 .. 824 1648 ....
Under present conditions only live boilers are installed
and there arc 4.75 sq.ft. of economizer heating surface
per nominal boiler horsepower. When the sixth boiler is
in place this will be reduced to 1.1 1 sq.ft. At present the
station is operating considerably below its capacity, and
only one section of the economizer is in use at a time.
Owing to this condition it is not fair to present the operat-
ing results obtained.
[As told in other issues of Power describing other
features of this plant, the station is the largest municipal
electric plant in the United State-. — Editor.]
Wfi&aft Causes &h±<e JrHngB* Effiffi-
caeiracy ©IT rLoc©fflni©]baEes?
I'.v E. R. Peakce
To what is the high efficiency of the locomobile mainly
due? Some are under the impression that it is due to
there being practically no steam pipe between the engine
and boiler to cause radiation and condensation. This
opinion does not appear to carry much weight wdien one
considers that there are many independent engines work-
ing with the steam conditions at the cylinder, both as to
temperature and dryness, the same as on the locomobile
and yet not having anything like its high efficiency.
In the locomobiles the engines are of the piston-valve
type, identical in all respects except for a few minor
details. Some of these sets, as built by Wolf and Garrett,
have the high- and the low-pressure cylinders placed on
the boiler at the firebox end, side by side, and are simply
jacketed with live steam at hoiler temperature, so that any
flow of heat through the high-pressure cylinder walls due
to the superheat is not lost, but is taken up by the jacket-
ing steam, eventually passing back into the engine.
That which appears to be the biggest factor in securing
high economy is the resuperheating of the steam between
the cylinders. There seems to be very little difference in
the results obtained whether the cylinders are arranged as
mentioned, and steam jacketed, or in tandem, with the
high-pressure cylinder jacketed by flue gases. This alone
tends to point to the gain being derived in the reheating,
thereby preventing condensation in the low-pressure cyl-
inder, which is undoubtedly responsible for the bad per-
formances given by many well-designed engines.
On the smaller sizes there is no reheater, the low-pres-
sure cylinder being jacketed with live steam. Usually,
these are very efficient, but do not come up to those hav-
ing reheating. In the latter type the consumption shows
marked reduction as the superheats increase, wdiich, in
the case of a AVolf engine of the tandem type rated at 60
hp., is as follows:
i
Temperature of saturated steam 190. 9C
Temperature of steam entering the high-pressure
cylinder 340. 0C
Temperature of steam entering the low-pressure
cylinder 171. 0C
Superheat entering the high-pressure cylinder 151. 9C
Superheat entering the low-pressure cylinder 57. 9C
Steam consumption at 43.2 b.hp 10.9 1b.
II
Temperature of saturated steam 190. 9C
Temperature of steam entering the high-pressure
cylinder 360. 0C
Temperature of steam entering the low-pressure
cylinder 191. 0C
Superheat entering the hiuh-pressure cylinder.... 172. 9C
Superheat entering the low-pressure cylinder 71. 4C
Steam consumption at 55 b.hp 10.29 lb.
The difference in the two cases is undoubtedly due more
to the increased superheat than to the heavier load, as
after the half-load point has been readied the consump-
tion is nearly constant. Like the locomotive, the greater
part of the evaporation takes place at the firebox, but av-
erages about 4 lb. per sq.ft. for the total heating surface.
This type of boiler has two other strong points in its
favor — there is no chance of leaky brickwork, and the end
plates and tubes being removable for cleaning purposes, all
parts are easily examined and kept in order.
The question now arises as to whether like results
could not be obtained on well-designed existing engines
by introducing a reheater between the high- and low-
pressure cylinders and carefully lagging them, assuming
that the gain in efficiency would warrant the expenditure.
034
P U W E R
Vol. 41, No. 19
The Hill-Tripp Pump Co., of Anderson, Inch, has
recently placed on the market a centrifugal pump de-
signed for a number of uses. One- to six-stage pumps
are made with capacities ranging from 10 to 20,000 gal.
per min., and these pumps are designed to pump against
heads of from 10 to 1000 ft. The double-suction single-
stage pump is designed for a maximum head of 300 ft.
and multistage pumps for heads up to 700 ft. For
higher pressures an extra heavy multistage pump is built.
The special feature of these pumps is the impeller,
with sides extending a certain distance beyond the vanes,
as shown in Fig. 1. The passage formed between the
two sides beyond the vanes is flared out. increasing grad-
ually to larger area. In all centrifugal pumps the water
leaves the vanes in a tangential direction and at prac-
tically the circumferential velocity of the wheel at the
extremity of the vanes. This being the case, the relative
velocity between the extended sides of the impeller and
the water is low and, as a consequence, there is little
friction. The shape of the extended sides of the im-
peller is much the same as the secondary part of a venturi
tube, with the added advantage that the tube travels with
the water. Owing to the design the velocity head of
the water is transformed into pressure before the water
leaves the impeller, and as it passes out into the casing
the movement of the water is slower than in the suc-
tion or discharge pipes. The loss occasioned by sta-
tionary vanes is obviated and, consequently, an efficiency
as high as ?2 per cent, is claimed for these pumps.
As indicated in the drawing at the left of Fig. 1,
single-stage pumps have a newly patented balancing
device consisting of a central rib in the pump casing.
vvhich will deflect the water discharged by the impeller
in such a way as to cause increasing or decreasing pres-
sure in the two sides of the easing. If the impeller
Deflecting Rib
builders of multistage pumps, with the exception that
the present arrangement is double-acting. As shown in
Fig. 2. a piston with a renewable ring is secured to the
shaft and rotates with the impeller. A pressure chamber
is located between this rotating piston and a stationary
part, also provided with a renewable ring opposing tin-
ring on the piston. Through a running clearance be-
tween the stationary part and a covered sleeve on the
' H? Balancing Chamber l
-Relief Outlet
Piped to Suction BaCover Sleeve.and Separator
Fig. 2. Detail- of Balancing Device
shaft, water from the high-pressure end of the pump
gradually finds its way into the balancing chamber.
Eventually, the pressure in this chamber builds up
enough to force the rotating piston away from the sta-
tionary element. In this way a circular passage is
opened up between the rings, and water flows from the
balance chamber to the relief chamber behind the piston.
The relief chamber is connected with the suction of the
pump, as indicated in the drawing. As the water es-
„</$
rti tf*h& ABSOLUTE VELOCITY WITH
^yji, w __. WHICH WATER LEAVES VANES
DEVELOPMENT OF WATER WAY WHICH
IS EQUAL TO SECONDARY PART OF A
VENTURI TUBE AND IN THIS CASE
TRAVELS WITH THE WATER
Fig. 1. Showing Special Features of Impeller Design*
should move to the left the pressure would increase on
the same side and force the impeller in the opposite
direction, or vice versa. In other words, the pressure
against ihe two sides of the impeller must balance and
hold the rotating element in a central position.
For the multistage pump a hydraulic device has been
adopted of the general type commonly employed by
capes between the rings the pressure in the balance cham-
ber is reduced until a balance is established. A thin
film of water is maintained between the rings, and the
rotating parts float continuously at a certain distance
from the stationary element. The balancing chamber
is made large enough to care for large differences in
pressure, which in high-lift pumps may amount to several
May 11. 1915
I' ( ) W E
635
Showing Vaeious Applications of the Pump to Deep-Well Head, High-Lift Centrifugal
Pump, and Vertical Discharge Head, Motor Driven
tons. It has been found desirable to make this pro-
vision in spite of the fact that each impeller is itself
hydraulically balanced independently of the balancing
system.
Should the piston have a tendency to move too much
toward the relief chamber, it will approach the outlet
to the suction of the pump and automatically reduce
the amount of water escaping. The pressure in the re-
lief chamber will then build up and force the piston
in the opposite direction, relieving the outlet and again
establishing a balam e.
Figs. 3 to 1 shea a variety of applications of the
636
P UWEE
Vol. 11, No. 19
pump. Pig. 3 i< a deep-well pump head equipped with
a four-cylinder high-speed oil engine, fitted with an auto-
matic cutoff fur control in case the pump lose-; it>
suction or the load is dropped tor any reason. Fig. 4
shows a standard multistage high-lift centrifugal pump
with the upper half of the casing removed. The con-
struction of the impeller and the balancing and relief
chambers is clearly shown in this view. Fig. •"> i- a
side view of the double-suction impeller split-case cen-
trifugal pump, and Fig. 6 show- the same pump directly
driven by an electric motor. Fig. 7 shows a vertical
discharge head equipped with a motor for driving and a
hard oil pressure pump.
By A. P. Connob
Some of the conditions of the contract under which the
United States Government buys electric current within
the District of Columbia are given herewith.
Schedule Xo. 1 provides that for a monthly current
consumption up to 3200 kw.-hr. the rate shall be 6c. per
kw.-hr.; up to 4545 kw.-hr., 5%c. ; T500 kw.-hr.. 5c. : 12,-
500 kw.-hr.. iy2c; all current in excess of 12.500 kw.-hr.
per month, 3c. But separate buildings (not connected by a
covered passageway) must Lie metered separately, so that
the total current used in a group of detached building-
occupied by one department might entitle that depart-
ment to the minimum rate, yet by the separate metering
process the maximum rate would be collected. Schedule
•1 is a work of art. as will be seen by careful reading.
SCHEDULE NO. 4— FOR BUILDINGS: WHERE PRIVATE
GENERATING PLANTS ARE NOW INSTALLED
For electricity used during months from April to Sep-
tember, inclusive, $0,025 per kw.-hr.
This service to be entirely optional with the Government,
and will become operative only upon the written request or
authority of the particular department or governmental es-
tablishment desiring it, and it will be furnished only during
the period from Apr. 1 to Sept. 30, inclusive, or for such por-
tion thereof as the service may be required; in cases where
service is furnished under Schedule No. 4, during the period
from July 1 to Sept. 30, inclusive, or any part thereof, and
where any service is required from the contracting company
at any time during the period from Oct. 1 to Mar. 31, in-
clusive, the charges for the service furnished during the
period from Oct. 1 to Mar. 31 shall be in accordance with
Schedule No. 1, 2, 3 or 5. as may be applicable and selected
by the Government, and the charges for the service furnished
during the period from July 1 to Sept. 30 shall be adjusted
to conform to the rates of charge in force during the period
from Oct. 1 to Mar. 31, or any portion thereof, and the con-
tracting company shall be paid the full amount of the dif-
ference. Schedule No. 4 is not to be available during the
period from Apr. 1 to June 30, inclusive, for buildings where
any service has been required during the period from Oct. 1
to Mar. 31, inclusive.
By the terms of this schedule, suppose during the six
summer months current to the moderate total of $2500
had been used at the 2%c. rate, and that during the win-
ter for a short period (a single day) it became necessary
to obtain current from the electric service company, the
only such contractor in the field, the answer according to
the schedule would be: '"Yes. we will furnish you the
current (service lines already in) for lie. per kw.-hr. pro-
vided you pay a penalty of $3500 for having taken cur-
rent from us during the summer (which we were glad to
sell at that time of the year) at 2%c. per kw.-hr."
It seems beyond the belief of a reasonable person that
such rates have Keen approved by the Government. This
is probably the most flagrant case of a contract unfavor-
able to the Government that can be found, and since it has
existed for a long period there is reason to believe that it
may be continued for many years.
Is it advisable for the engineer of a department to
accept and insist on the 2y2c. rate (after the apparently
sincere advice of an official close up to the Secretary not
to attempt to save money for the Government at the risk
of his personal welfare and possibly his position), or
should he permit the handing over of more than double
the money for the service during the summer in order to
avoid the personal risk!' If he succeeds in the saving,
what is there to it for him except '"art for art's sake?" If
be fails to get through the winter without a holdup, what
then? Perhaps a little light obtained in a court proceed-
ing in a test case in which the subject matter was the rate
and the apparently piratical charge for back service,
would clear up the situation. It has been established be-
yond a doubt that 2c. a kilowatt-hour is a familiar rate
of the same utility for current in buildings in the imme-
diate vicinity of Federal buildings. The rates which the
same utility charges other parties is a matter of record
with the Public Utility Commission of the District of
Columbia (and easily obtainable), and under the control
of the Government.
The time of the day in which the greater part of the
current is used by the Federal departments is certainly
favorable to a central station carrying a substantial com-
mercial and street-railway load, and in this case the
utility has one of it- power stations located most centrally
with respect to the governmental buildings and depart-
ments.
The State Department recently rented a certain hotel
building and by means of a few feet of conduit and
rewiring, it was possible to get power (electrically) from
the plant of the State. War and Navy Building at a cost
of about $30 a month, but the Comptroller of the Treasury
decided that there was no authority of law for extending
the government service or system to a "private building,"
although the hotel was used by the department for
office purposes. The current bought from the Potomac
Electric- Power Co. will cost about $100 a month.
It is gratifying to learn that the project to erect a cen-
tral power station by the Government which has so long
met with steady opposition from certain quarters is pro-
_ 3S ng and the initial bids will soon be opened. The
hydro-electric project to utilize the enormous water-power
possibilities of the Potomac River in the District of Co-
lumbia does not progress. The curious might ask, "Why
are these things thus ':''
Correctly Designed Steam Lines skillfully erected are no
more likely to fail and interrupt the service than other
features, not duplicated. It is a matter of common experience
that the hydraulic piping in a plant causes less trouble than
the low-pressure house-service piping, because of the differ-
ence in installation. The same is applicable to steam piping.
A Sulzer Diesel Engine, built for Messrs. Harland & Wolff,
for generating electricity in that firm's shop at Belfast, is
said to be the largest Diesel yet constructed to a definite order.
It is of the two-stroke cycle, single-acting type with six
cylinders, and was designed to develop 3 7 ." 0 b.hp. at 142 r.p.m..
though on trials 4500 b.hp., or about 750 b.hp. per cylinder, was
maintained for a long period. The cylinder dimensions are
approximately 30 in. bore by 40 in. stroke. — "Gas and Oil
Power."
May IK 1^15
P 0 W E R
637
dhiammimeys for Onl° sumd! Coal-
IcDtmirinininig
By F. II. EtoSENCRANTS
SYNOPSIS Available data on chimney design
relate almost solely to coal-burning plants, while
little is applicable to nil burning. For given con-
dition,* a much smaller chimney is required for oil.
That a difference exists in the requirements in stack
dimensions for a plant burning coal and for one burning
oil is generally understood. Most available data on draft
requirements and stack dimensions are applicable to coal-
burning plants, so the designer of an oil-burning plant
must rely upon his experience and judgment and on the
meager amount of serviceable information in designing
this important part of the plant. The most compre-
hensive treatment of stacks for oil-burning plants that
the writer knows of is that written by C. R. Weymouth,
presented before the American Society of Mechanical
Engineers and published in bulletin form by Chas. C.
Moore & Co., of San Francisco, Calif.
In a coal-burning plant it is important that the
draft shall be sufficient to burn the maximum desir-
able amount of coal per unit of time per unit area of
grate. Draft in excess of this merely provides addi-
tional overload capacity which may or may not be desir-
able. The objectionable feature to excessive draft in a
coal-burning plant is the interest and depreciation charges
for the increased cost of the stack to produce the excess
of draft. However, engineers are more afraid of a de-
ficiency than of an excess, and formulas deduced are
usually liberal.
In a coal-burning plant the rate at which the boiler
is steaming will demand a certain rate of combustion
which requires a proportionate increase in draft. There-
fore, the dampers will demand the required amount of
attention from the attendant.
In an oil-burning plant the rate of steaming demands
the combustion of oil at a certain rate, but this is depen-
dent upon the position of the oil-control valve and not
upon the existing draft. The boiler might be operated
from no load to full load with the same damper setting,
provided that setting would furnish the required amount
of air for the maximum load. So at all loads below the
maximum there would be an excess of air, and the smaller
the load the greater the excess and consequent decrease in
boiler efficiency. This condition would be accompanied by
a smokeless stack and a careless or ignorant fireman might
be led to think that he was running the plant economi-
cally. The trained fireman of an oil plant knows that a
faint haze at the top of the stack is desirable, as that
tells him that if he admits less air the stack will smoke
and if more the stack will be clear and an unknown
amount of excess air entering the furnace.
If the possible draft of a stack for oil burning is in
excess of that required to produce the maximum desirable
load, it has the double disadvantage of possible large
excesses of air and of possible overloads on the boiler
which might be destructive to the settings. In addition
to this, there is the same disadvantage that exists with
coal-burning plants, namely, the interest and deprecia-
tion charges on the cosl of the excess slack capacity.
Comparative Cross-Sectional Areas of Stacks
Assuming the same velocity of the gases up the chim-
ney for oil as for coal stacks, the former need be much
smaller in cross-section than the latter for the same ca-
pacity.
Assuming an excess of air of 50 per cent., the weight
of flue gases per pound of oil will be about 22 lb. Assum-
ing a heating value of 19,000 B.t.u. per pound and a boiler
efficiency of 75 per cent., the weight of flue gases per 1000
effective B.t.u. will be
22
19,000 X 0.75
X 1000 = 1.544 lb.
Assuming values for coal which are attainable with the
same amount of skill as those quoted for oil, we have, al-
lowing 100 per cent, excess air, 25 lb. of flue gases per
pound of coal; 12,500 B.t.u. heating value per pound; and
a boiler efficiency of 70 per cent. Using these figures,
the weight of gases per 1000 effective B.t.u. becomes
25
12,500 X 0.70
X 1000 = 2.857 lb.
It follows from the preceding calculations that, assum-
ing the same rate of steaming in both cases, the amount
of gas which will pass up the oil-burning stack will be
only 1.544 -f- 2.857 = 0.541 as much as that which
passes up the coal-burning stack, therefore an oil-burning
stack' for a given capacity need be only about 0.54 as large
in cross-section as a coal-burning stack.
Comparative Heights
It is impossible to give any hard and fast rule for
the height of a coal- or oil-burning stack, as so much
depends upon variable factors, such as altitude, length of
breeching, character of fuel, rate of combustion, etc.
However, it can be conclusively shown that in any and
all cases the height of an oil-burning stack will be much
less for the same set of conditions than that of one burn-
ing coal.
The draft in any case must overcome the resistance of
(1) the furnace, (2) the passes of the boiler, (3) the
damper box, (4) the breeching including its turns, and
(5) the stack itself.
Comparing the oil-burning with the coal-burning plant
with reference to the first, it is evident that the furnace
resistance of the former is much less than the latter. Due
to the injector action of the oil burner, the furnace re-
sistance in the case of oil burning often is negative; i.e.,
the injector action of the burner produces a slight pres-
sure. The furnace resistance when burning coal varies
with the character of the fuel and the variation in thick-
ness of fuel bed and with the rate of combustion. With
average bituminous coal and a rate of combustion of 20
lb. of coal per square foot of grate per hour, the furnace
resistance amounts to about one-quarter inch of water.
With reference to the second element of draft, the oil-
638
P 0 W E R
Vol. 41, No. 19
burning plant again has the advantage. As shown, the
weight of gases for oil as compared with those for coal
for the same rate of steaming is a little over one-half as
much; so the velocity of the gases through the boiler is a
little over one-halt' as great. Since the resistance to the
flow of fluids varies with the square of the velocity, the
boiler resistance for oil burning will be not over one-
third of that for coal.
The resistance of the breeching and stack will, of
course, depend upon the velocity of the gases through
them, but assuming the velocity to be the same in the two
cases, the resistances would also be equal, or nearly so.
It is evident from the above that the draft requirement
for burning coal is in excess of that required for oil and
since the draft of a stack varies with the square-root of its
height, the height of a stack for burning coal is much
greater than thai tor burning oil. It will nearly always
be twice as high or more for the same rate of steaming.
It might be suggested that an oil-burning boiler could
be operated at a higher rate of evaporation per square
foot of heating surface than is usual for coal, since the
weight of gases is so much less for the same rate. It has
been found in many tests that the efficiency is improved
when so operated, but the temperature produced in the
furnace is destructive to the setting and this disadvan-
tage more than offsets the slight gain in efficiency.
It would seem that, inasmuch as the factors affecting
draft resistance in oil burning arc so much less variable
than with coal, the problem of stack design could be
made exact, which is desirable.
OmpIhiKC RepreseiMattioinis ©f Power*
Plaint Losses
By E. D. Dreyfus
SYNOPSIS— By mi mis <,\ a set of charts the op-
erator is apprised directly of the approximate loss
incurred, in dollars and cents, through failure to
maintain the prescribed conditions.
The large central power plant usually employs a small
army of operatives. Those who supervise are generally
conversant with the technical requirements necessary for
the highest efficiencies. Imt the force as a whole does not
appreciate the significance of the different engineering
factors involved; although from a strictly mechanical and
operating viewpoint, the men may be capable and trust-
worthy. Taking cognizance of this, the West Penn Trac-
tion Co., of Pittsburgh, set about to devise a remedy by
displaying graphically the necessity for observing con-
ditions that have been found to produce the most efficient
results. The accompanying charts show the attempts
made to fasten the attention of the power-plant employee
upon the enormous losses that accumulate during the year
when the best working conditions are not maintained.
The object in Fig. i \> to impress upon the firemen the
importance of a high C02 percentage. First, it i> assumed
that an instrument has been installed which will give a
direct reading of the C02 in the flue gas. Then the
"burette" of the C02 apparatus is reproduced on the chart.
with a simple scale. A standard rule is drawn opposite.
with a dollar and cents scale substituted for the customary
inch and fractions. The normal, or standard, percentage
has been taken at 15 per cent., although a slightly lower
rate may prove best in practice. Since this represents
the most economical working condition, it is made to cor-
respond to the line of zero waste, or avoidable Losses. The
rise of the liquid in the "burette" (imaginary, of course,
while considering the chart) will be read on the "measur-
ing stick" as indicating greater and greater unnecessary
losses
Owing to the losses in dollars and cents increa
(inversely) more rapidly than the changes in CO., per-
centage, the measurements cannot be taken on the hori-
zontal line since plain scales are used in both cases. Eence,
slanting lines are drawn to conned corresponding values.
The charts are constructed upon a simple basis. A
fair estimate of the coal to be consumed during the coming
year under favorable operating conditions is the founda-
tion upon which rests all the percentages for the different
operating factors. Each case is treated independently to
avoid complication, although to have dealt with these fac-
tors in a cumulative manner would lie the technically cor-
rect way.
Each plant must, of course, be individually considered
when arriving at the percentages in any ease, and the fig-
ures in the charts are merely indicative of the method.
In view of the quality of the coal and the flue tempera-
ture-, the following CO; percentages were determined
upon :
Percentage Percentage
CO; Percentages Loss in Fuel CO» Percentages Loss in Fuel
IT, 0.000 9
0.S0S
1 T -". 1 1
2.840
4.130
5.690
9.660
L3 020
16.320
21.650
Coming to Fig. '.'. giving the losses for operating prime
movers at less than normal rated capacity (usually the
economical point), it is presupposed that there are a num-
ber of units installed which may he cut in and out to con-
form to the load, so a- to maintain a high load factor on
the individual machines. Unless a separate chart is pro-
vided for each unit, a single one must necessarily be of a
compromise character in view of the different sizes and
types. Such a compromise curve must lie employed with
discretion.
Fig. :i. for feed-water temperatures, is similar to Fig.
1, but the losses have been represented by heavy black col-
umns intended to display proportionate waste of coal, each
block having its money value indicated. This variation
was introduced to ascertain if the one arrangement would
possess more force and effect than the other.
In condensing-turhine station- the importance of high
vacuums is now fully appreciated. In this case the com-
promise i bait of Fig. | was arranged. Other charts may
be made if further refinements are carried out in the sta-
tion.
The power-plant operator lias not the same direct ap-
peal to the personal interests of his men as is possible in
May 11, 1915
I'u \Y EB
639
PER CENT
OJ^
:
1
z
3
4
^$70000
"$65000
"$mm
■:
:
"$40000
■■■$15000
~ $10000
5$25000
~$20000
i
$5000
5
^^
g
7
8
_9_
10
II
IZ
13
. _~~~
J4
...
:
15 I
t
- 1
Fin. 1. Chart fob C02, Showing Money Lost in
Wasted Coal through Careless Firing
C/
OK
210'
CORRECT
TEHPCRATURE
Vu
Mones Loss Due to L"« Feed-Wateb
Temperatures
some other lines, but the security of the employee's po-
sition and, accordingly, his source of livelihood are in-
separably linked with the best interest of the owner and
Miiacoo
Q
\
Uj
\
f$%000
Ul
5
V
ifsoooo
~j
\
: '$70000
s
\
o
\
;-450000
It
'
'450000
.
It
§\
'$■10000
',.$30000
s
>-
(0 cfc
■A
a.
tt
I lv
'$20000
ifl
5^ S>
a.
in
:,$ioooo
in
o
> ^Js>| ^.<«
to
w 4
Fig. 2. Chart Showing Money Loss Due to
Operating Turbines at Partial Load
29l2
29
STAND ARD_ TOWORK_ TO
' NO LOSS AT 28
$15500
f
1500
SAVINO
'LOSS
$2500
Fig. 4. Vacuum Chart. Showing Money Loss
per Year for Variations below 28 In.
his inherent value is gaged in proportion to what he ac-
complishes compared with the best practicable results ob-
tainable within his sphere of duties.
640
P 0 \Y E B
Vol. 41, No. 19
iriimg
:or luag
P.Y A. L. COOK
•II
SYNOPSIS — Branch circuits and feeders, insula-
tion, wire sizes, fuses, panel-hoards, switches, etc.
The first article of the series (May 4 issue) cov-
oltagt s and systt ms employed, the "National
ric Code/' the types, number and -pacing of
lamps, and the determination of the lighting load.
When the size and location of the units have been set-
tled the branch circuits can be arranged. The "National
Electric Code" specifies that a branch circuit which is
dependent upon a cutout shall not carry more than 660
watts or have more than 16 sockets and receptacles, except
by special permission in cases where Xo. 14 wire can be
carried directly into keyless sockets. Under these con-
ditions. 1320 watts and 32 sockets may be used. The
arrangement of these branch circuits should be such that
the lamps on one branch are grouped as closely as possible.
The lamps near the windows should be controlled sepa-
rately. It is also best to so plan the branch circuits that
the wires will not have to cross heavy beams or girders.
Details regarding various arrangements of branch circuits
will be taken up later.
Incandescent lamps are so sensitive to changes of volt-
age that it is necessary to maintain a steady and as nearly
as possible constant voltage on them, irrespective of the
load on the system. The tungsten lamp, however, is not
as sensitive as a carbon lamp : for a difference of 1 per
cent, in voltage the 12-volt tungsten lamp changes 3.i> per
cent, in candlepower, while for a carbon lamp the change is
SOAmp.
150ft.
(a) TWO-WIRE SYSTEM
+
2SAmp.
£ [Neutral)
OAmp.
A.
1
?
■0
25Amp.
V
v
9
Lamps
50Amp.
Lamps
25Amp.
(b)THREE-wlRE SYSTEM
Fig 3. Two- and Theee-Wire Systems
5.6 per cent. Because of this effect, lighting circuit.- should
not be supplied from motor circuits, but should be run
independently. The voltage drop in a lighting system
carrving full load should not exceed the following:
Branches, 1.5 per cent.; mains, 0.7; feeders. 1.3; total.
3.5 per cent. When there are no mains, the drop allowed
for the mains is included in the feeder drop.
Lamps used for indoor lighting should always be oper-
ated in multiple, as a series system with arc or incandes-
cent lamps is not desirable, because of the high voltage
necessary and lack of flexibility. Even the operation of
120- or 240-volt lamps in series on a 550-volt system is
not good practice except in special cases, such as railway
power houses or car barns. Because of the limitations of
the incandescent lamp the lighting system must employ
about 120 or 240 volts, the former being preferable.
The systems of distribution include two-wire and three-
wire circuits, cither direct or alternating current, and
1
28.9 Amp.
2
28.9 Amp.
A
A
^ 1
1 Lamps^s\
T
28.9 Amp.
Erf :§
1 ie.7AmpW
r I
(a)TMREE- PHASE SYSTEM
16.7 Am p.
$■$ Lamps _
J^/6.7Amp.
3>
16.7 Amp.
Ymfrk
4 (Neutral) OAmp.
(b)THREE-PHASE,FOUR-WIRE SYSTEM
Fig. 4. Current and Voltage Belatioxs in Thbee-
Phase System
three-phase or two-phase. The branch circuits are gen-
erally two-wire and will be so considered in the present
discussion. The feeders and mains, however, may be ar-
ranged on any of the systems mentioned. The two-wire is
the simplest, but the voltage is limited to that of the
lamps, which cannot exceed 240. When it is remembered
that by doubling the voltage, only one-fourth as much cop-
per is required for a given percentage drop, the advantage
of using as high a voltage as possible is apparent. On the
ether hand, the use of 240 volts on lamp circuits increases
the cost of maintenance, and the efficiency of the lamps
is lower, so that 120 volts is more satisfactory. By means
of the three-wire system, with 120 volts between each out-
side wire and the neutral and 240 between the outside
wires. 120-volt lamps may be used; but the power will
be transmitted at 240 volts and the copper required will
be three-eighths that required for a two-wire 120-volt
system. The amount of copper would, of course, be greater
than if a 240-volt two-wire system were used, as this
would take one-quarter of that necessary for a 120-volt
two-wire system. The advantages in the use of 120-volt
lamps will, however, generally justify the extra cost of the
three-wire system. Fig. 3 represents a two-wire and a
three-wire feeder system carrying a load of 50 amp. at
120 volts. One-half of the lamps would be connected
across each side of the three-wire circuit.
The three-phase system is sometimes used for lighting,
three wires being used, with the same voltage between any
two; see Fig. 4. The lamps are divided equally between
the three phases. Sometimes a fourth wire, called a neu-
tral, is provided, as shown at 6. In the arrangement
shown at a. the copper required is three-fourths that for
the two-wire system shown in Fig. 3-a. and in the four-
wire, three-phase system the copper is one-third that
sary for the two-wire.
May 11. 1915
POWER
641
The two-phase system is illustrated in Fig. 5. The
lamps are distributed equally across the two phases, ami
it will be seen that the arrangement is the same as two
single-phase circuits. There is no electrical connection
between the two phases, and consequently no voltage be-
tween them. The copper required is the same as for the
two-wire system in Fig. 3-a. Frequently, two of the wires
are combined, as shown at b. The copper required for this
arrangement is 0.73 times that for the two-wire system.
Further details of these systems will be taken up when
the method of calculating the circuits is discussed.
Conduits
In the majority of installations rigid, unlined iron con-
duit is desirable, although the first cost is greater than
where the wires are run exposed. The greater freedom
from damage to the circuits and the improvement in the
appearance of the wiring will generally justify its use.
In factory wiring, it is sometimes better to run the feed-
ers exposed, using iron conduits for the mains and
branches, particularly in an extensive plant where the
feeders can be so located that they are not likely to suffer
damage. The conduits must be large enough to allow the
wires to be pulled in after the conduits are in place with-
out damaging the insulation. The size depends, therefore,
upon the number of bends. The "Code" requires that the
maximum number of bends shall not exceed the equiv-
alent of four right-angle bends, and if more are necessary
a pull-box must be inserted in the run so that the wire
may be pulled in sections. It is desirable to make the
radius of the bends as great as is consistent with other
limitations. The stock bends, which can be purchased
from the conduit manufacturers, can be used, except in
special cases, where a longer-radius bend is desirable.
The ordinary iron conduit consists of soft-steel pipe made
25Amp.
Phase A
25Amp.
h.
f k
i
25Amp.
o*
25Amp.
V
k h
(a) TWO -PHASE SYSTEM
25Amp.
25 Amp.
35.4 Amp
Lamps
2 5 Amp
Lamps
25Amp
Lamps
. 2 5 Amp
( b) TWO-PHASE, THREE-WIRE SYSTEM
Fir;. 5. CURRENT AXD VOLTAGE BelATIONS IN TwO-
Phase System
in standard-weight iron-pipe sizes and threaded the same.
It has a heavy, smooth coating of enamel on the inside to
facilitate pulling in the wire and is either enameled or
galvanized on the outside. The galvanized conduit is
more desirable where il is to be painted after installation,
and it can also be more easilv grounded as required by the
"Code."
In Table 6 are given conduit sizes for various sizes of
wires, covering most of the conditions met in practice and
suitable for fairly long runs. For longer runs, if the
number of bends is decreased, the same sizes may be used ;
for shorter runs, the size may in some cases be reduced.
An approximate rule is to choose such a size that the wires
will just be contained inside a circle three-quarters the
outside diameter of the conduit. For alternating-current
work all the wires of a circuit must be contained in the
same conduit. This is required by the "Code," because
if run in separate iron conduits there would he excessive
Fig. 6. Illustrating Wires in Conduit
heating of the conduits and a greatly increased drop due
to the alternating magnetic field produced by the current
flowing in the wire. This effect will be greater the larger
the current, but even for the smallest wires the rule
should be followed. If the conduits are of brass, fiber or
tile, the wires can be safely separated in different ones, but
even then the drop is so great that it is generally better to
combine the circuit in one conduit. If the current is so
great as to require more than one wire for each lead of the
circuit, and it is not feasible to put them all in one eon-
TABL.E 6— SIZES OF UNLINED IRON CONDUIT FOR 600
VOLT N. E. C. STANDARD RUBBER WIRES
^—Number of Wires in One Conduit — ,
Size of Wire One Two Three Four
14* y2 in. % in. % in. 94 in.
12* % in. % in. % in. % in.
10* % in. =4 in. 1 in. 1 in.
8 ' ■ in. 1 in. 1 in. 1 in.
6 % in. 1 in. 1% in. Hi in.
5 % in. 1% in. 1% in. 1% in.
4 % in. iy4 in. Hi in. 1% in.
3 % in. Hi in. 1% in. 1% in.
2 ■':, in. 1% in. 1% in. 2 in.
1 :;.i in. 1 >•• in. 2 in. 2 in.
114 in.
1 ¥4 in.
1% in.
2 <j in.
2% in
2% in
2% in.
3 in.
3% in.
3 V, in.
2 in.
::■". in
4 in
2 in.
3',-. in.
4 in
2% in.
4 in.
4 1 . in.
2% in.
4 in.
4 ' . ill.
2% in.
3 in.
3 in.
3 in.
^ in.
c in.
% in.
000
0000
300,000
400,000
500,000
600,000
7.111,000
S00.000
900,000
1,000,000
1,250,000
1,500,000
1,750,000
2,000,000
14 duplex*
12 duplex*
10 duplex*
Based on runs not over 100 ft. long" and not over four
standard bends.
•These sizes are solid; all other sizes are stranded.
duit, the leads should be divided into two or more groups,
each containing all the poles of the circuit. The proper
arrangement for a three-phase circuit is shown in Fig. 6,
where the leads of the three phases are 1, 2 and 3 respec-
tively, 1-ff and 1-b being of the same polarity. This rule
applies for all types of alternating-current systems except
the two-phase four-wire, which is practically the same as
two single-phase circuits, and phases .1 and B may be run
in separate conduits. For direct-current circuits it is
satisfactory to employ separate conduits for each wire, if
of large size, unless there is probability of a change being
made to alternating current.
Exposed wiring may be run on porcelain cleats, or in-
sulators, the spacing being as follows:
Voltage
0 — 300
301—550
Distance from Surface
Distance between Wires
642
I'll W EE
Vol. 41, No. 19
For wires not loss than No. 8 B. & S. gage in locations
where they will not. lie disturbed, the spacing may lie made
6 in. and the wires run from beam to beam, without break-
ing around. By this means, feeders and mains may he
run in a direct line the entire length of a building and
supported by the beams or roof trusses. This results in
minimum cost and makes a very satisfactory arrangement.
Insulation
Wire for interior work may have two kinds of insula-
tion— rubber or weatherproof — depending upon the
method of running the wires. Rubber wire must be used
M' installed m conduit, but for exposed or so-called eleal
wiring, a cheaper insulation is allowed. The rubber in-
sulation used in most installations is called "Code" wire
and is manufactured in accordance with very rigid rule-
contained in the "National Electric Code." Every coil
must bear the stamp of the inspection department of the
Hoard of Fire Underwriters, so there is no difficulty in
identifying such wire. Sometimes, for important instal-
lations, a quality of rubber insulation which is better than
••('ode" wire is used, and its greater cost is often justified
by the resulting reduction in breakdowns on the system.
Public buildings, railway stations, office buildings, and
sometimes industrial plants can afford to use this better
quality for greater insurance against interruptions to the
service. No insulation poorer than "Code" wire should
ever be used, even if the work is not inspected by insur-
ance representatives.
The insulation used for exposed work consists of two
braided-cotton coverings over the copper conductor, the
inside covering being impregnated with a weatherproof
compound, and the outside one filled with a fireproof com-
pound. This is called "slow-burning weatherproof" wire.
Sometimes another type, called "slow-burning," is used,
this being similar to the other except that the entire in-
sulation is fireproof. This is satisfactory for dry places
where the wires are run exposed on insulators.
In Table 7 are given the safe carrying capacities for
various sizes of wire used for interior work as specified in
the "National Electric Code." Column A gives values
for rubber and column B for "slow-burning weatherproof"
and for "slow-burning." It will be noticed that for rub-
ber wire the current allowed is less than for the other in-
sulation, because it is necessary to keep the rubber-covered
wires at a lower temperature to prevent damage to the
insulation. The currents specified for rubber insulation
will cause the wire to run at about 29 deg. F. above the
surrounding air.
The "Code" makes no distinction in carrying capacity
between alternating and direct current. For alternating
currents, especially at 60 cycles, there is a greater drop,
particularly for large wires. Even with 500, 000-circ.mil
cables, the resistance is 2y2 per cent, greater and for
1,000,000 circ.mil it is about 11 per cent, greater. This
would result in the wires running somewhat hotter when
carrying alternating current.
Fuses and Circuit-Breakers
All wiring must be protected by fuses or circuit-break-
ers in such a manner that the circuit will be opened if the
rated current is exceeded. The size of the fuse must not
exceed the carrying capacity of wire as given in Table 7.
For example, a No. 1 wire, if rubber covered, would be
protected by a 100-amp. fuse, and if "slow-burning
weatherproof," would have a 150-amp. fuse. When ci-
table 7 — CURRKNT-CARRVINc; CAPACITY OF WIRES
FOR 600-VOLT INSULATION, N. E. C. STANDARD
FOR INTERIOR WIRING
Rubber Other
Insulation, Insulations,
Size, Size, Amperes Amperes
Circ. Mils B. & S. Gage A B
1,624 18* 3 5
2,583 16» 6 10
4,107 II 15 20
6,530 12 20 25
10,380 10 25 30
16,510 S 35 50
26.250 6 50 70
33,100 5 55 80
41,7-10 4 70 90
52,630 3 SO 100
66,370 2 90 125
83,690 1 100 150
0 125 200
133,100 00 150 225
167,800 000 175 275
211,600 0000 225 325
: ,000 275 400
Hi". 325 500
500,000 400 600
600,000 450 680
700, ( 500 760
800,000 550 S40
600 920
1,000,000 650 1000
1,100,000 690 1080
l.L'00,000 730 lir.o
1,300,000 770 1220
1,400,000 S10 1290
1,500,000 850 1360
1,600,000 850 1430
1,700.1 930 1490
1,800,000 970 1550
1.900,0110 1010 1610
-."iiii.OOO 1050 1670
Note — Voltage drop is not considered in the above table.
•Wires smaller than No. 14 B. & S. gage should not be used
except for fixture wiring and pendant cords.
cuit-breakers are employed without fuses, they must not
be set more than 30 per cent, above the rating of the wire
as given in the table. The excess current which the fuses
will carry continuously is about 10 per cent, for inclosed
and 25 per cent, for link fuses, which allows small over-
loads without interrupting the service. The rating in
Table 7 is based only on the safe current-carrying capa-
city of the wires, and should not be exceeded; but it takes
no account of the drop in the wires. In many cases, the
length of the run is so great that the drop with the rated
current would be excessive, in which event a larger wire
must be used.
In lighting installations of any considerable size, there
will be a large number of branch circuits, each provided
with the proper fuses. For convenience these are grouped,
as far as possible, in a panel-board, containing the neces-
sary branch fuses and in some cases the control switches.
For industrial plants, slate panel-boards contained in steel
cabinets with steel doors are the most satisfactory. For
office buildings, etc., slate panel-boards with steel cabinets
set flush with the surface of the wall are generally re-
quired. The doors are preferably made of wood to match
the trim of the building, although steel doors are some-
times used. While economy demands as few panel-boards
as possible, a single board should not contain more than
30 branch circuits. If more must be supplied from the
same point, it is better to use a double panel-board with
two sets of busbars and two doors. Each branch should
contain fuses for protecting the circuit and in many cases
a branch switch is also provided. These switches should
be placed next the busbars, so that when open, the branch
circuit fuses may be replaced without danger of short-cir-
cuit or shock. Branch circuit switches are not really
necessary, except when used to control the branch circuits.
In many industrial establishments, it is best to keep the
panel-boards locked and provide switches outside for con-
trolling the lights. This arrangement should also be used
in office buildings. For public buildings, such as railway
stations, most of the lights are controlled directly from
the panel-board switches and in many factories this is
May n. 1915
P 0 W E R
643
Bcr/timore Buifdjngr
Bone to save the cos! of additional switches. The feeders
Supplying the branch circuits must be run to some central
mini of supply such as panels on the switchboard. I E
central-station service is used, h is best to install a regu-
lar switchboard except when the number of feeders is
small, in which case a panel-board can be used. In every
i it a I ile switch disconnecting every wire of a feeder
Should lie provided for each circuit. The largest size of
lose allowed by the "Code" is 600 amp. for voltages up to
•..'•"iii and H»o amp. for 600-volt circuits. Circuits requir-
ing more current than this have to be protected by circuit-
beakers. Lighting circuits are not subject to large over-
bads, so that the fuses should not blow unless there is a
port-circuit. If circuit-breakers are used in place of
.Hid are arranged to automatical-
ly trip out when closed on an overload,
the -witch may be omitted. Fuses or
circuit-breakers should be large enough
tn give the full carrying capacity of the
wires, in accordance with Table 7, even
if the actual load on the feeders is con-
siderably less.
Wiring Accessories
A detailed discussion of the wiring
fittings, such as sockets, -witches, out-
let boxes, and the like, does not prop-
Ely belong in this article, but a few
ftggestions may be of value. For ex-
posed conduit work, complete lines oi
devices such as condulets have been de-
veloped to meet almost any require-
ment, and their use assists greatly in
making neat work. For ceiling nutlet-.
where there is no danger of the lamps'
!nt, a "T" fitting may be conven-
iently used, the drop to the lamp con-
■feting of a piece of half-inch conduit.
Enameled reflectors are provided com-
plete with sockets, which can be at-
tached directly to this pipe. Glass re-
Efectors require the use of an ordinary
keyless socket with a suitable shade
holder. Tungsten lamps will operate
satisfactorily in this type of fixture.
unless there is excessive vibration, in
which ease it may be necessary to use
flexible cord for the drop. For con-
cealed rigid conduit work, the outlets
are provided with pressed-steel boxes,
which should be galvanized rather than japanned, to as-
sist in grounding the conduit system. Control switches
outside the panel-boards may be either of the rotary
pi push-button variety; the latter is better for offices and
il.e rotary switch, which is somewhat cheaper, is satisfac-
tory for industrial establishments. Nothing smaller than
a LO-amp. -witch should tie used, for the sake of me-
chanical strength.
Conductivity anil Resistance are relative terms. It is cus-
tomary to divide all material into three groups depending
on their relative conductivity: First, metals and their alloys
■are good conductors: second, electrolytes, so called because
jthey may be decomposed by passing electric current through
jthem, are poor conductors; third, resistance, bad conductors or
jgood insulators consist of such well-known materials as
rubber, glass, ebonite, shellac, mica, etc.
?stm©i&e=
The new '.'-.'-.-inn Consumers' Building, State and
Quincy St.. Chicago, has an SVo-ft. asbestos-lined steel
stack in a shaft at the rear of the building. This stack.
301 ft. high above the street, was originally intended to
serve a heating plant in the building, but later service
was secured from a plant in the Baltimore Building, an
older eight-story structure at the rear.
In the basement of the Baltimore Building is one of
the heating plants of the Illinois .Maintenance Co., which
supplies steam lor heating throughout the block and also
Jnr the Fair, a large building occupying the adjacent
Smokestack of
9'Diam.—>
Section
4x4x}gBentL,
tjnchorectlo
masonry ana1
boltedtosteel
top & bottom
STACK '■ fi'Fhncjed Copper PI.
Section B~B
Connection between an Outside Smoke-Stack and ax Inside Smoke-
stack at Two Adjacent Buildings i\ Chicago
block. The smoke tlue from this plant extends in the
building only to the third floor, where a connection is
made to an unlined outside steel stack supported on can-
tilever brackets. It was realized that with this large
power plant it would be impossible to control the smoke
to -iieh an extent that it would not be obnoxious to tenants
in the higher adjacent Consumers' Building, while it
would soon blacken the white glazed terra-cotta facing of
the rear of that building. In order to forestall these diffi-
eulties the [llinois Maintenance Co. made arrangements
to connect its outside stack on the Baltimore Building
with the inside stack of the Consumers' Building.
The arrangement and tin' details are shown in the il-
lustration. As the two stacks are not in line the connec-
tion i- inclined from north to south a.- well as from east
6 1 1
I' ( ) \Y E II
Vol. 41, No. L9
tn west. A spei ial feature of the construction is that the
connection (which weighs aboui II tons and extends
across the alley) is supported Erom the framing of the
Consumers' Building, so that no part of its weight is
carried upon the lower stack. The bottom of the connec-
tion simply telescopes into the latter stack, a flashing
being arranged in the joint. This allows Tree expansion
and contraction of the stack, while in rase of lire and the
fall of the walls of the Baltimore Building (a aonfireproof
structure) the stack would drop away without affecting
the Consumers" Building.
The connection between the two stacks is a shell 8 ft.
10 in. diameter, with an elbow at each end. The bottom
elbow enters the top of the shorter stack, and the upper
elbow connects to the side of the stack in the Consum-
ers' Building. The weight is carried by 1%-in. hangers
with 2-in. pin attachments to brackets on the stack con-
nection and pin plates on the columns of the building,
as shown in Fig. 2. The lateral thrust is taken by a pair
of horizontal box-lattice struts bearing against the col-
umns of the building at the level of the 14th floor.
The design for this stack connection was made by Mun-
die & Jensen, of Chicago, architects for the Consumers'
Co. Building. The steelwork was built and erected by
the Hansell-Elcock Co., also of Chicago. — Engineering
News.
The Beaver crossbar die stock, manufactured by the
Borden Co., Warren, Ohio, differs from other die stocks
in several important features.
A bar extends across the top of the tool, carrying a
plug which rests on the end of the pipe. The dies are
made in two sections. The lower one does the rough
work of starting on the pipe with teeth especially formed
for this purpose. The die remains stationary during
starting and after the upper section begins to cut this
lower die gradually withdraws from the pipe, until it no
longer touches, as shown in the illustration.
The upper die is a narrow receding die and constantly
opens as the thread is cut, producing a perfect standard
Beaver Crosshbad Die Stock
pipe thread. These dies have the further advantage of
following the partial threads cut by the first section,
which reduces the labor and insures a correct thread
pitch without a leader screw.
The principle involved is as follows: A swiveled plug!
extends down between the dies to the bottom of the upper!
-eet h.n in starting. The pipe is started and threaded ast
usual. When the work of the lower stationary die is com-
pleted tin- pipe end comes in contact with the swiveled
plug, raising it as the second set of dies cut the thread.-
Raising the plug lifts the side posts, turns the engaged
die cam, and gradually opens tin1 dies at the pipe taperl
until the thread is completed, when the dies are released;
there is no hacking off.
The operation of the tool is simple. The dies are!
sei h\ the bandle shown, and the pipe is threaded with-!
out the attention of the operator. To cut another thread 1
the crossbar is simply pushed down, which re-positions 1
the tool. The body of the tool is made of practically")
one piece with wide openings to allow chips to get away!
and for free oiling facilities.
A universal guide centers all sizes i/4- to lV^-in. The
tool is regularly furnished with double-ended, reversible!
■ lie y2- t,> 114-in. Extra 14- by %-in dies can be I
furnished, also all sizes of dies, either right- or left-hand. 1
The Dinkel steam trap, illustrated herewith, employs
, pen. copper-float bucket A, a valve B and connee- I
tions, all of which are inside the trap chamber. Theft
valve is held closed by its own weight and the pressure >
Sei tio\ theotjgh the Dinkel Steam Tbap
within the trap chamber, and is opened by an increase
pressure exerted upon it by the action of the float
the working parts are attached to the end plate C, the
are easily removed.
As water fills the trap chamber it raises the float until
it strikes against the top of the chamber. As it can go
no further the water continues to rise and overflows into
the bucket, which, when full, sinks to the bottom of the
chamber. This action brings the projection of the lever
a rm against the thimble D on the top of the valve stem
and lifts the valve from its seat. The water in the
bucket and that above the top of the bucket is then
discharged through the connection E and through the
valve. When the discharge ceases the bucket rises until
it floats and the valve closes.
A body of water is always left above the valve seat
after each discharge, which prevents the escape of steam.
This trap is manufactured by the Flushovalve Co.,
536-538 Broome St., New York' City.
;ed
'ey
May 11, 1915 l'DW K R
a niHiii iiiiiiiiiiiiiiiiiiiiiittuiiim mil iiiiiiiiiiiii iiiiiiiiiiiiiiinii iiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiii
645
maam
The coal that produces the largest net returns per dol-
lar invested is the coal to burn. If the right kind of fur-
nace is not under the boilers to burn the coal used, it is
good business to put in that furnace and make all other
ry changes.
All of the various grades of coal mined in the United
- must be and will be burned in some way or other,
and it is the engineer's part to burn it with the greatesi
economy, both for the sake of the owner and for coming
generations.
To burn coal with maximum efficiency, exhaustive tests
have been and are being made by competent engineers
under United States Government supervision. By study-
ing their reports one can decide with certainty on the
kind of grate and setting to install. To make such tests
oneself would be out of the question, because of the ex-
pense. Government reports should be studied.
It Bs ilhe lUtt&a© Tlhasags
"It is the small details which go toward making per-
fection ; and this last is no small thing." An artist -aid
this when asked why he was taking such care in the rep-
resentation of a familiar object forming but a minor por-
tion of the work under his hand. What he replied is a
truism, something we are inclined to admit in the ab-
stract and prone to forget in the concrete. Perfection,
one-hundred per cent, efficiency, is the unattainable; yet
that should not and does not usually prevent striving for
that goal. But what is it that stands in the way. barring
the attainment of perfection? Just a Utile thing, the -mall
fractions of that last one per cent, between the attain-
able ninety-nine and the unattainable one-hundred. Small
ami insignificant in themselves, those figures that repre-
sent the nap are the wondrous monument that marks the
progress of the world, of science, of engineering, of chem-
istry. They are the fruit of the toil and the study of the
Looking back upon the methods of a few years
ago with the searchlight of today, it is difficult to re-
member that, in their time, those methods formed the
apex, that those who strove to surpass them were pioneer-
ing in the same way as those wdio now strive to pass the
mark.
Today, as yesterday, all of the works of the world are
but aggregations of the small details, their components;
and none of them is without significance. And as the
work stands as the monument of its builder, so does
each of its components. Each small detail as it lacks per-
fection contributes to the imperfection of the aggregate,
and still more will it detract if. inherently imperfect,
its functions have not been properly coordinated with the
other components. Just as the weakest link governs the
Btrength of the chain, so is the validity of any structure
dependent upon its weakest component. In itself of little
account ami of small moment, when located at a strategic
center it becomes the keystone of the arch. If it fails, then
i he deluge and the storm, the wreck ; and then, sometimes,
rebuilding.
All the lessons of the ages an bound up in a \'ow \.
easy to remember, easy to forget, lint to those who can
read their story it is written in letter- of flame, ""Forget
you not of the details, nor of the end thou wouldst attain."
The safety of life and property demands that only care-
ful, experienced men shall be allowed to operate steam
plants.
The temptation to hire cheap help or to give a de-
serving friend a job is too much for many employers.
They welcome an excuse which enables them to send
the importuning candidate to some disinterested board
or commission, with instructions to get a license or to
get placed on a civil-service list.
But how is this disinterested board to find out if
the man is qualified?
Most such boards have members who are educated,
in the common sense of the word — that is, they have
been to school. An examination to them means a writ-
ten test in which all the candidates are asked a given
set of questions on which they are marked like so many
school children.
If they stopped to think, they would realize that it
is nearly impossible to get up a single examination that
will tell a true story of the candidate's fitness. When
it is necessary to offer examinations every few weeks,
each of which must be dilferent from those which have
preceded it, the problem becomes wholly impossible of
solution along these line-. The result is that a few
questions are thinly disguised and made to answer for
a series of examinations. Shrewd men can pick out
the few questions and see through the disguises, and
armed with the knowledge that there will be little varia-
tion, they coach men who are normally unfit, so that
they can get licenses. Likewise, it is just as necessary
for the men who are fit to take this same coaching in
order to pass, for the questions of necessity have little
connection with the everyday practice of their trade.
How the essential qualities that make a successful en-
gineer can be truly judged except on the job has always
been more or less of a puzzle to us. What a man will
write as an answer to a question dealing with a blown-
ont tube, and what the man will do when confronted
with the actual accident, are two different things. It
is very much like training soldiers by giving them written
examinations. Instead of that, they are drilled until
their work becomes automatic and their officers know
that a- a matter of habit they will obey orders and obey
them in the same way every time.
Just so an engineer should lie trained so that if he
hears the sound of escaping steam in any direction he
will unconsciously do the right thing, and do it at once.
It is better lor him if he understands the reason why
and doe. n intelligently, but as a matter of safety the
646
P 0 W E P
Vol. 41, No. 19
important thing is that he shall do it without stopping
to think.
The question of the competence of the man to produce
the maximum amount of service from the minimum of
coal is also something that can be told only on the job,
and in which he can be trained only on the job. No
amount of questioning, nor even of preparation for ex-
amination, will add to the power produced per pound
of coal, nor will it give much of a line on what the man
will do once he gets on the job.
We suggest to the various legislatures which are an-
nually struggling with this problem, that they investigate
the means of training engineers in safety and efficiency
and then fit their laws to what is possible.
Ssiifegftuias'dliiE&gi &lh\© Buss ^©©srm
Close scrutiny of the arrangement of busbar compart-
ments in a number of power stations indicates the de-
sirability of paying more attention to safety features in
laving out and operating this important part of the plam.
In high-tension installations adequate space is general!;
conceded to busbar "and oil-switch equipment, for the two
are closely related and there is economy in copper where
short and symmetrical connections are possible between
disconnecting devices and busbar sections. It is the good
mechanical job that best serves the needs of a high-tension
gallery or switch room, and straight, simple runs of wire
or copper tubing, combined with what might he called a
clean-cut switching arrangement without complications in
its apparent relations to the circuits, generating units?,
transformers and busbars, make one of the best possible
designs.
In lower-voltage work it is not uncommon to find the
space assigned to switches and busbars cramped in the ex-
treme. "Week after week these portions of the equipment
stand the demands of service without a "hitch," and then.
without an instant's warning, a heavy short-circuit on
the distribution system or possibly on some interstation tie
line, hacked up by the generating capabilities of perhaps
half a dozen units, transforms these compartments into a
spectacular sample of the lower regions. The manner in
which arcs backed by ample generating capacity will at
times communicate to neighboring switch cells, accom-
panied by the carbonization of cable insulation, need not
be detailed here, hut the initiated appreciate the wisdom
of allowing plenty of space in passages around such com-
partments and of using barriers of substantial thickness in
providing accommodations for this sort of equipment. To
the casual visitor to a plant the allotment of liberal spai
to busbar and switch mechanism housed in by concrete or
other barrier construction appears almost needless, but
when operating emergencies occur plenty of elbow room is
invaluable.
Too little attention has been paid in many plants to the
lighting of such rooms by permanently installed lamps
wired in conduit and controlled from outside the room it-
self, and often, where permanent lamps are used, the
sizes are too small for throwing the necessary light into
recesses of cells. Moreover, it is petty economy to install
a low-powered unit without a suitable reflector in this part
of a station. Switch mechanism is almost always painted
black with asphaltic compound, and the point is worth
looking into whether it would not pay in some eases to
use white enamel paint or a judicious combination of the
two, m order to make the adjustable parts and points of i
lubrication stand out more prominently.
In station- where two or more men are on duty per
shift it would not be a bad plan to provide outside the
bus room a pilot lamp which will show the presence of
anyone within, and in not a few stations too little care
is taken in admitting visitors to this part of the build-
ing. If there is any place in a station outside the main
operating and boiler rooms where first-class lighting, am-
ple space, local telephone service and dual means of exit
are desirable, it is the bus room.
Present-day engineers, machinists ami others who work
in the midst of noise seem to regard it as a necessary evil,
Pump operators who are working beside noisy, nervel
racking metal gears — so clamorous that it is impossible
for them to hear spoken words without having them
shouted into their ears — should look about for means to
reduce the din. These noises can be lessened if not totally
eliminated.
It has been demonstrated repeatedly that when har-
assed by noise the average man cannot concentrate on
his work as well as he can in quiet surroundings. Then
why not make shop and plant conditions favorable to
maximum work and production by cutting out all un-
nei essary noises?
It is difficult to make workers in offices consider this
problem, because there is comparatively little noise in an
office. Office men who once worked in noisy places should
appreciate the difference and be keen to take advantage
of every possible point helpful to the highest economy and
maximum production, and at the same time if they wish
to do a good turn for humanity they will do all in their
power to promote quietness for their subordinates who are
now compelled to put up with disagreeable surroundings.
Quietness is a factor of efficiency that is too frequently
completely overlooked.
3S
One of the greatest benefits of classroom lecture or
lodgeroom study, as against self-education by soli-
tary study, is the spoken word when correctly spoken.
In classroom recitation or discussion the free and famil-
iar use of terms becomes a habit, while in study at home
the utterance of the same terms may be only at rare
intervals if at all. Should occasion arise for com-
parison, which will "show up" to the best advantage,
granting an equal knowledge of the subject matter?
Unless words and terms are used with assurance they
cannot carry the weight of conviction and will, there-
fore, serve to defeat the object of their use. A splendid
exercise for the lodgeroom is the use of a good pro-
nouncing dictionary, every fellow to take a turn at the
definition and pronunciation of words and engineering
terms more or less commonly used. Many perfectly
good words will go lame and be so disguised by improper
accent as to be hardly recognizable.
m
The prompt adoption by the Ohio Board of Boiler
Pules of the Code of Specifications for the design, con-
struction and operation of steam boilers and other
pressure vessels is very gratifying. It is hardly believ-
able that either inertia or opposition can long prevent
its universal enforcement.
May 11. L91S
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiimmiiiiiiiiiiiimiiiiii
P ( ) W E R
! ,1 Ill'i'
647
Coriresp©ini(dleini€(
minium iiimiii iliiiiniiiiiiililllilililiiiiii iiiiiiini i. Him mini milium K, , B nunn mm , Illllinlllll , unuuuihium,^
A. Haimd^" G^sr foa» 2inisa<!
The illustration shows a handy device for the boiler
cleaner or inspector. We used a 2x8-in. oak plank 4
ft. long and beveled the ends on the under side. The
wheels used were old worn-out valve disks from a feed
Boiler Cleaner's Car
pump put on with lagscrews about li in. from the end,
as shown. In this way we have a car that can he pro-
pelled to the back end of a boiler in a jiffy and we can
come out dry.
A. C. Chhisman.
Girard. 111.
Si
The stuffing-boxes on two ice machines in a small re-
frigerating plant gave considerable trouble. Unless three
or four times as much oil as is usually needed was sup-
plied, the rod- would cither run hot or leak and the pack-
Suction Header
Original
Location of
Oil Cup ■
Lubricating Ammonia-Compressor Piston Rod
ing would soon wear out. It was difficult to keep engi-
neers for a time alter the plant was started, and most of
them kept out of trouble with the ammonia rods by using
excessive quantities of oil.
Finally, a man came along that stuck to the job. As
soon as he was settled he turned his attention to the am-
monia rods. The oil-cup connections to the stuffing-boxes
struck him as peculiar and not according to the best prac-
tice, so he decided to change them.
The sketch shows the oil cup in the changed position
and also shows its original location. The machines were
of the horizontal double-acting type. In this machine there
is usually more or less gas escaping through the connec-
tion to the suction line. With the original connection
the escaping gas carried much of the oil along with it into
the suction line and into the system; in fact, the system
was loaded with oil. as was found later. Connecting the
oil cups to the under side of the stuffing-box overcame
this defect and thereafter a small amount of oil was
needed.
Thomas G. Thurston.
Chicago. 111.
Coiradloirasiffag Coal ona ©a
At the request of an oil salesman we experimented with
a is-in. copper coil 12 ft. long in connection with the
force-feed lubricator, the object being to break up the
iz'-i'p,pe
From Force Feed Pump
-i^ lZj-
■- Check
To Cylinder
Condensing Coil as Coxxected
oil by the addition of a little moisture. The steam pres-
sure carried was 140 lb. gage, superheated to about 4-K»
.leg. F.
The result was so surprising that we think it will in-
terest the readers of Power. With the same amount of
oil formerly used the valves appeared to stick. Doubling
the quantity of oil took care of that trouble, but the piston
became noisy and developed a decided pound at each end
after a 12-hr. run. and it was decided the steam-ring
springs wen- too stiff. New springs were put in, but this
did not stop the noise.
An examination 12 hours later proved the lubrication
was deficient, and there was no vestige left of a glaze on
the cylinder wall of six years' standing. The oil atomizer
was removed, and the engine again operated with the
original amount of oil with the most gratifying results.
The question is, what effect does the superheat (80 to
100 deg. F. ) have on an emulsion of cylinder oil and
water! The oil is a standard high-grade article made
648
POW E I!
Vol. 41, No. 19
from Pennsylvania crude and for superheated steam. The
i of llif condenser coil was to cut down the amount
of oil used or to substitute a lower grade.
C. II. Reed.
Easl < ihicago, I nd.
About a year ago it became necessary to renew the
tallic packing on the Corliss type valve stems of a large
pumping engine. To gel a tight job with such packing it
Powvi
Fig. 1.
Bonnet
With Packing Case
is necessary to take great care in truing and grinding the
ring.- and ball washers, and the job is expensive. The
superintendent objected and said: "We want something
we can make ourselves; it is up to you to dope out a de-
sign that is simple, steam-tight and cheap." My first
attempt is shown in Fig. 1. I don't pretend to be able to
say what happens in the grooves and nozzles, but the
steam is so busy chasing itself in and out of the grooves
that little finds its way to the end of the sleeve.
Fid. 2. Modified Form
Fig. 1 is on the exhaust valve stem of a high-pressure
cylinder working steam at 500 lb. pressure. It was put
in on Feb. 10. 1914, and has run 24 hours every day since
and is practically steam-tight.
Fig. 2 does away with the packing case and need not
fit the stem so closely. It is best for stems that do not
run true. Pig. 3 is now used on the low-pressure ex-
haust valve stems and is scaled with steam from the low-
pressure receiver at 6 lb. gage through the pipe shown
or in other cases this may be used as a drain pipe.
For all other stems the nozzles all point toward the
Fig. 3. Low-Pbessube Type
valve. If anyone is interested in the details of the ma-
chine work 1 will be glad to supply them.
S. H. Fabnswohth.
Chicago. 111.
■ysvetmtuiTnm Psp© JRep^fhredl
Early in the forenoon one day last winter I discovered
the vacuum had dropped from 28 to 27 in. and was still
going down, and when we shut down at noon it had
reached 25 in.
Condenses Pipe Split
Such unsatisfactory vacuum denoted something wrong.
so I investigated the outside piping of the barometric
condenser and found a crack t in. long and ! t in. wide
in the overflow pipe about 25 ft. from the ground. To
avoid a shutdown before the end of the week various
schemes were tried. First, the millwright filled the
crack with waste and covered this up with brown paper
shellacked to the pipe, then tried sheepskin, hut that also
May 11, 1915
pow e i;
649
wes disappointing. Glazier's putty was next tried and
it held. This soon brought the vacuum to 27 in., but
it had to be renewed every day.
The plumbers were finally given the job of putting on
Smooth-On cement for a permanent job. We then saw
what had caused the pipe to burst — it was full of ice —
and to prevent its recurrence, a small supply of steam
was piped in to keep the water ahove the freezing point.
1 wrapped canvas round the pipe from top to bottom of
the crack in the shape of a bandage, then had it painted
over.
It is about a year since this happened and the vacuum
is as good as it was before the pipe was ruptured.
Charles- Sword.
Cohoes, 1ST. Y.
v
When all the terminals of a resistance and the corre-
sponding controller fingers are numbered and the re-
sistance boxes are the same in number and of the same
relative size as the ones indicated on the controller-con-
necting diagrams, then the procedure of connecting the
devices is a simple matter. On controller prints, however,
the resistances are often so indicated as to make it diffi-
cult for the uninitiated to identify corresponding sections
and points of the conventional print and of the resistance
boxes as received.
A mill operator who was familiar only with contin-
uous-current operation, installed a three-phase, slip-ring
induction motor to drive the cylinders for the glazing of
gunpowder. His print gave the connections as indicated
_j
FIGJ FIG.2. RS
R| -b. RIQ. R5.C.R5
°R6
NO. I
R3 UR4
NO 2
FIG.3
RJ
Figs. 1 to 3. Diagrams Representing Resistance
Connections
in Fig. 1 and the resistance boxes as received were in
tour units, or boxes, as in Fig. 2, in which it will be noted
that all the terminals intended to receive controller wires
are numbered accordingly, but that the end terminals are
not numbered unless they are to receive controller
wires. Thus, in Fig. 2, the top box has one unmarked
terminal ; the next, two and the third, two ; and appar-
ently there are no wires to fill them. The unmarked ter-
minals are for the jumpers that connect the several boxes
together. On a less involved resistance layout, the ob-
ject and the manner of realizing it would be more evi-
dent. In the present case, the correct location of the
jumpers was obtained as follows:
It was noted in the sketch (Fig. 1) that from 7?x one
path led to the left through H, and R,, to R.„ and that
another path led to the right through Rt and 7?7 to B10.
Accordingly, the box with L\ in the central part, with
/.', tn one side and I! . to the other, was placed upon the
floor. It was plain that the next box to be handled had
to have Ra or R7 in it : therefore, the Rn-R0 box was laid
end-on to the box already placed. As Fig. 1 showed the
marks to progress toward the higher number, the second
box was placed with the 7?,., toward the /.'... Installing
jumper a, as in Fig. 3, then gave a continuous path f nun
R1 to /?„. The third box with 7.'r and Rl0 in it was then
placed end-on to the first box, so that by employing
jumper b, a continuous progression from R1 to /.',,, was
had. This completed what seemed to be a single long
box in Fig. 1, but which was really two boxes and part
of another.
There was now only one more to handle and only one
place for it. One end was marked R5, as was also one end
of the last box handled. As the latter box had insu-
lation washers that divided it into two parts, it was mi
placed as to bring the two terminals marked i?5 together;
these were then connected by jumper c, which gave an
independent path from R2 through R5 to /?„, just as in
Fig. 1. The coils were then marked 1, 2, 3, 4, the
jumper connections marked for identification and the
boxes placed one above the other in their marked order.
It was then noticed that the nameplates were numbered,
and if the boxes had been assembled in the order of those
numbers in the first place, the positions of the jumpers
would have been evident, as the nameplate order was the
same as that worked out.
J. A. Horton.
Schenectady, N. Y.
gs
P^a&ftiimgl BJew Headless aim WsifteiT"
In most boiler rooms, the renewal of burnt-out or
broken headers in horizontal water-tube boilers is a long
and hard job. The following method, requiring little skill
and small expense for special tools, has been successfully
used.
Two 1-in. steel rods are needed, each long enough to
reach from the outside of the front header through the
tube to the outside of the rear header, leaving about
six inches surplus on either end. Both ends are threaded
and lifted with heavy square nuts.
The water tubes, circulation tube and mud-drum nipple
are carefully crimped inside the header with an ordinary
crimping tool. The header is raised sufficiently to free
the mud-drum nipple, by using a crowbar and blocking
up with wood blocks. If the tubes have been crimped
sufficiently, little trouble will be experienced in drawing
the header from the tubes. Some of them may stick
occasionally, however, and then one of the rods is run
through the tube and used as a battering ram from the
other end, knocking the inside of the header and tending
to knock it away from the tubes. After it has been
loosened in this manner, a slight downward pull will
remove it from the circulation tube.
One of the rods is then put through one of the top
t ulics ami the other through one of the bottom tubes.
Each rod is run out through the handhole on the other
end and. if the boiler is of inclined-header type, through
one of the ordinary handhole caps so that the turning-nut
will have good bearing surface. If the boiler is of the
G50
POWE i:
Vol. 41, No. 19
vertical-header type, the handhole caps cannol lie used, as
the] are no1 sel in alignmenl with the tuhes. In this
ease, pieces of '^-m. iron fared with a wood block to
prevent damage to handhole faces must be used. The
new header is then fitted into the circulation tube and
brought as nearly into position as possible, with the ends
of the red- protruding out through the handholes. The
are fitted over the rods and the nuts put on. Then,
by simply tightening up on the nuts and guiding the
oilier tubes into place, the header is drawn up into posi-
tion and placed over the mud-drum nipple. The tubes
are then ready for rolling and flaring, after which the
rods are removed and the boiler is again ready for service.
E. T. Gray.
West La Fayette. I ml.
v
Psreveinvttiinifg W"gi&eTr=IHIa2imtfim©2* nna
The illustration shows a scheme to prevent blowoff
failures from water-hammer. An ordinary pop valve is
placed between the boiler and blowoff valve on a short
riser, to prevent scale from lodging under the valve seat.
Pop Safety Valve
Safety Valve on Blowoff
The pop should he set about three pounds heavier than
the safety valve on the boiler. On vertical boilers having
a greater head of water in the boiler, this will have to be
increased to correspond to the head of the water above
the valve. The area of the pop should be equal to the area
of the blowoff pipe.
Charles Fenwick.
Wapella, Sask.
[There would appear to be objection to the foregoing,
because the boiler might be drained of water if the safety
valve on the boiler should be slightly sluggish or stick
at some time. Also, the man blowing down might be
scalded if not carefully protected. — Editor.]
©a!I°E,Eii|giiii5i© PfistoEn Tro^IbS©
A short time ago I was called in to locate, if possible,
the trouble with an llx9-in. two-stroke-cycle oil engine.
It had recently been installed and was built by a steam-
engine company that had entered the oil-engine field.
The engineer's explanation of the trouble was that, after
starting, the engine would run for about a dozen revo-
lutions and then stop and was even much harder to turn
over by hand than when cold.
The engine was one of the hot-ball semi-Diesel types
with a long piston. Upon examination I found that the
piston diameter was 0.01 in. smaller than the cylinder
bore when both were cold, and when heated the head
end of the piston expanded more than the cylinder and
stuck. I turned the piston down to gV in. smaller than
the cylinder bore, both being cold, and the engine oper-
ated satisfactorily. It might be well to add that many
oil-engine builders do not allow sufficient side clearance
between the piston rings and the grooves, and as a re-
sult the rings soon bind and become ineffective, due to
carbonization, etc.
M. E. Griffin.
Franklin, Penn.
)a^g»irafflms
idr. Low's article on turbine-velocity diagrams, May 4
issue, considers only the theoretically perfect turbine,
when there is no friction or other losses.
It occurred to me that it might be worth while to go a
step further, so I have plotted the actual-velocity diagram
of a small single-stage turbine having three rows of
moving blades. The bucket speed is 225 ft. per sec. The
steam is supplied to the nozzles at 160 lb. per sq.in.
Velocity Diagram for Single-Stage Turbine
absolute and expanded therein to atmospheric pressure.
The theoretical steam velocity resulting from this pressure
drop is equal to about 2920 ft. per sec, but losses in the
nozzles reduce this considerably.
The other losses shown are the friction and eddy losses,
etc., which occur as the steam passes through the blades.
These are proportionally very large in a machine of this
size, because the attempt is made to utilize the large
energy drop in a single stage. Besides this, the coeffi-
cients of loss in this case have been taken well down.
The figures show that about 40 per cent, of the energy
of the steam is converted into useful work. This is
May 11, 1915
POWER
651
represented by the areas shown in simple cross-sectioning.
And the water rate of such a turbine would be ap-
proximately 40 lb. per horsepower per hour.
1'akkek M. Robinson.
New York City.
Dai
Not long ago I found it necessary to remove the cross-
bead from a liJxlS-in. engine in order to babbitt the shoe.
Arrangements had been made at the shop for this work
to be done on the following day, and as it was necessary to
the engine running as long as possible, about an
hour's time was allowed to take the crosshead out. The
2%-in. piston rod was screwed into the crosshead about
3*4 in. It was known to be an easy fit and no difficulty
was anticipated.
The start was made quite easily, but the second quarter
turn and every turn for the full length of thread was
about all that two men could pull on a four-foot bar.
After the first few turns I concluded the trouble was
due to the piston rings. There were six cast-iron eccentric
snap rings % in. wide and about % in. deep, tapering to
fij in. at the joint. These rings were doweled to the
piston, so that when turning it was necessary to turn
them also, and the force being applied to their ends
caused them to expand and greatly increase the friction.
This was relieved considerably by turning the engine
slowly and turning the piston at the same time. Under
these conditions it took nearly four hours to unscrew
the rod. The reason this difficulty had not been en-
countered before on this engine was because the rings had
been doweled when the cylinder was removed to make
other changes and the cylinder had been slipped off and
back on over the piston.
E. P. Haines.
Baltimore, Md.
Gas E.sqpE<D>sn©E2is aim Boiler
Ftuhp nances
Mr. De Blois' letter in the April 20 issue, page 553,
regarding his experience with a gas explosion in a boiler
furnace, and the letters of comment thereon are highly
interesting. The writer's experience, covering many gas
explosions of various kinds, leads him to offer another
explanation as to the cause.
Taking the conditions as they existed : The ashpit
doors were sealed, which would mean that no air could
reach the fuel except from the tuyeres or through the
door. The boiler was being forced and the coal fed rap-
idly. From this we must assume that the furnace was
more than usually hot and that there was a large quan-
tity of green coal on the side on which the door was
closed. As there was no possibility of air getting to
this coal from below, it would be subjected to destruc-
tive distillation with the consequent evolution of a large
volume of gas of a high calorific value. This gas, un-
diluted with air, would be drawn by the stack draft
through the setting, mingling with the air and possibly
burning in the rear of, or beyond, the setting. (It is
quite possible for two streams of gas and air to exist
in adjacent and clearly defined areas, without forming
an explosive mixture, particularly if moving in one direc-
tion.) Tlic sudden admission of a large amount of air
caused a disturbance that resulted in the breaking up
and intermingling of the gas and air stratas and the
instantaneous formation of an explosive mixture. From
the violence of the explosion it would appear that the
explosive mixture bad filled the setting before ignition
took place.
As to preventive measures, one can only suggest that
under similar circumstances the other fire-door be left
slightly open, to allow sufficient air to burn whatever gas
is being formed. The writer would like to know the
style of setting, the nature of its connection to the stack,
and the amount of stack draft at the fire-door.
S. M. Quixx.
Detroit, Mich.
Commenting on the letter by L. A. De Blois, on the
subject of gas explosions in boiler furnaces, it seems that
the information given in response to the inquiry sent
is not conclusive. Obviously, however, the explosion
was due to an improper gas mixture. The writer be-
lieves that the importance of proper regulation of draft
to meet changes in load has not been given as much at-
tention as it deserves. Most manufacturers of damper
and fan regulators emphasize the sensitiveness of their
apparatus. Regulators of the open-and-shut, or non-
compensated, type are inherently sensitive and will, if
in good working order, cause a complete travel of the
damper or fan-regulating valve with a slight change in
boiler pressure, sometimes under 1 per cent. The writer
is of the opinion that, while such regulators make a good-
looking record on a pressure gage, their use is rarely
justified, and this for the reason that it is not good
practice to force a fire of either anthracite or bitumin-
ous coal up to brilliant incandescence and then shut the
draft off entirely or merely leave the draft due to a short
stack. Regulators of the compensated type which cause
only partial travel for slight changes in steam pressure
are better, but in general they are not compensated
enough to prevent results somewhat similar to those
produced by the open-and-shut type. Compensated reg-
ulators, as received from the manufacturer, will generally
give complete travel with steam-pressure variations of
less than 2 per cent., and in many plants where the load
variation is frequent and considerable this practically
amounts to open-and-shut regulation. This type of reg-
\ilator also makes a good steam-pressure record.
While criticizing the use of such apparatus, the writer
is most emphatically in favor of the use of automatic
regulators designed so that a considerable variation in
pressure will be required to cause total travel of the
damper or fan-regulating valve. In most plants a varia-
tion in steam pressure of 5 or 6 per cent, is not objec-
tionable, and a regulator which is compensated to require
as much variation as this for total travel will subject
the fire to much less fluctuation in temperature and in
gas composition than a regulator of the type mentioned
above. The steam-pressure chart, however, will not be
as near a true circle as with the other type ; but the
charts from the C02 recorder will be uniformly higher,
and the furnace economy will be perceptibly better.
Emphasis should also be placed upon complete auto-
matic regulation as against a makeshift device such as
mentioned in one of the letters published. A control
which requires frequent juggling by the attendant in
652
P 0 W E K
Vol. 41, Xo. 19
to make it cover the requirements is unsatisfactory.
because no two attendants have the same ideas and many
of them have wrong ideas as to the proper control of
draft.
The writer appreciates that the statements made may
not apply directly to the conditions described by Mr. De
Blois an I I qualified to express any opinion
as i" the probable cause of the accident There is. how-
ever, a point in the design of boiler-flue dampers which
should not be lost sight of; that is. that a flue damper
should be made short enough so that when it is in the
extreme closed position there should be a considerable
percentage of opening either at the ends or around the
outside edge of the damper. Most manufacturers pro-
vide this, but the percentage of opening seems to vary
derably with different makers. I believe that gas
explosions, which occur so frequently when banked fires
are suddenly put into service, are often due to a lack of
sufficient space around the flue damper. This is an in-
teresting and important question, and I hope that it will
be thoroughly discussed in Power.
D. L. Bellixgee.
Glens Falls. X. Y.
In the issue of Apr. 20, page 553, L. A. De Blois gives
an account of trouble from gas explosions in a boiler fur-
nace and he invites comment. The installation consisted
of three boilers connected to one stack by a breeching,
each boiler being fitted with an underfeed stoker. A fire-
door was provided on either side of the stoker in each
boiler front. One engine-driven blower was connected to
the three stokers. It is not stated what type of blower,
but I assume that it is of the fan type. It is assumed
that the boilers are set in brick and also that there are
dampers in the throat connections between the boilers and
the breeching.
One boiler only was being operated, the others presum-
ably being cold. Usually, steam is carried on two at a
time. The main-stack damper was open and the ashpit
doors were sealed. Consequently, the only regulated air
inlet is through the blower duct and through the fire-
doors when open. The boiler was being forced, and the
stoker was feeding coal rapidly. The fireman opened one
of the fire-doors and removed a clinker which obstructed
the blast tuyere. On the removal of the clinker a gas
explosion followed, injuring the fireman. The stack clean-
out door was blown open.
We may assume that the explosive wras of a mixture of
CO and other gases with air. Further reference to other
combustible gases than CO will be omitted. If combus-
tion were perfect there would be no CO. If combustion
is incomplete we have both CO and C02 in the escaping
gases; and when the proportion of the CO to the CO, is
about six to one we have a condition desired in a gas
producer. When a fan-blower discharge pipe is closed or
obstructed the quantity of air flowing is reduced. This
condition is often met with in cupola practice. A tuyere
becomes obstructed with slag, cooled by the blast ; and
until the slag is removed the flow of air is reduced and,
consequently, the temperature of the bed.
If we are correct in our assumption of the quality of
the explosive mixture, where does the mixture come from?
Much coal is being fed into a hot fire ; the admission of
air is cheeked, CO is produced, and the temperature of
the furnace drops. On opening the fire-door more air is
admitted and the furnace temperature is further lowered.
Probably, if nothing more were done at this time and the
door were left open, there would be no explosion, as the
increased draft would carry off the combustible gases.
But if the air flowing in at the door and the CO already
generated do not immediately make an explosive mixture,
one must look for another air inlet. There remain two
other possible sources — the throat dampers of the cold
boilers and leaks in the boiler setting. Under proper
forced-draft conditions there is one of two conditions in
the boiler spaces — a plenum or a balance. Under either
there will be little or no inflow of air through leaks. But
there is no plenum and no balance, because the proper
openings for the admission of air are obstructed and be-
cause the stack is trying to pull as the damper is open.
There is a partial vacuum in the boiler spaces. My recol-
lection is that teste carried out by Professor Breckenridge
on a new battery of brick-set boilers at the St. Louis Ex-
position showed that the inflow of air through the settings
was large, and that he mentioned a case in which the
quantity of air so inflowing amounted to 30 per cent, of
the total stack gases.
Assuming that air did flow in through the settings or
through the throat dampers of the cold boilers, or both,
there is a mixture of CO and air, and possibly in propor-
tions necessary for rapid combustion. The temperature
in the boiler spaces is comparatively low, the draft is re-
duced, and the gases are not promptly removed. There
is now an explosive mixture awaiting some condition
necessary to combustion. The fireman removes the ob-
structing clinker from the blast tuyere, intense heat and
flame are produced locally, the flame and the explosive
mixture come together, and an explosion follows.
I have said that the air flowing in through the open
fire-door probably did not mix with the CO to form the ex-
plosive gas in large or' dangerous quantity, for the reason
given, and for this additional reason : In hand-firing fresh
fuel is added through an open door, air also enters
through the opening, but a heavy explosion does not always
follow. Therefore, fresh fuel and an open door are not
necessarily the cause of an explosion. Yet with heavy hand
firing and checked draft, even in the case of internally
fired boilers, there do occur ''puffs," which are due to the
rapid burning of a small quantity of comparatively con-
fined gas. If there is a quantity of explosive gas in the
boiler spaces, there will be explosion on the introduction
of flame.
It may be suggested that I have not given a sufficient
reason for the checking of the draft. Possibly there is
another reason. The throat connection between boiler
and the breeching may have been large enough for the
normal rating of the boiler, but not quite large enough
when it was steaming at much above rating. Again,
when three boilers are connected by a breeching to one
stack set at one end of the breeching, the cross-section
of the breeching at the further end is usually calculated
for one boiler at a little above normal rating. We do not
know that the connections were arranged in this way. but
we know that the boiler was being forced.
Because the foregoing is largely conjectural and infer-
ential, I cite the following experience: In 18S8 1 was
assistant engineer on some tests instituted in order that
the best way to fire boilers with oil-gas might be learned.
One of the boilers used was a two-furnace Scotch boiler.
The furnace mouths were closed by removable iron plates.
May 11, 1D15
P 0 W E E
653
Oil-gas and air were introduced through mixer burners;
the oils experimented with were Astatki and American
crude petroleum. These tests were made at North
Greenwich, London, Eng. Oil from abroad was usually
shipped in barrels. The Baku oil line had not then been
built, and tank ships were not in general use. The tests
were successful so far as evaporation of water per pound
of oil was concerned, but were stopped when the price of
crude petroleum jumped to 6d. (12c.) per gallon on the
dock; the price of London steam coal being at the time
lis. ($4.08) per long ton.
The oil was vaporized in a producer by steam, in some
tests superheated (with results which those who have tried
it know), in others saturated, and in still others saturated
with a later addition of superheated. We learned
that a brick bailie before the burner or, better, around it
was necessary. Pockets of water which were present in
the oil of course gave no oil-gas; the flame went out; and
when the pocket was exhausted and oil-gas again flowed
from the burner the incandescent brickwork reignited the
gas. It should be said that what we called gas was in
reality a vapor and not a fixed gas.
On one occasion, soon after lighting off, the flame went
out for a moment. The coverplates had not been put in
place. An attendant threw a bunch of lighted oily waste
into the furnace to ignite the gas when it came on again.
But it had already arrived. The explosion was violent,
and the brickwork in the combustion chamber (dry) was
loosened. I had other proof of the force of the explosion,
for I was standing immediately in front of, and only a
few feet from, the boiler when the bunch of waste was
thrown into the furnace. There was no other explanation
than that the furnace and the combustion chamber were
filled, the former partly and the latter probably com-
pletely, with an explosive gas. Did not the combustion
chamber, breeching and stack base mentioned by Mr.
De Blois contain an explosive gas? The stack clean-out
door was blown open.
A later experience, and one more like that of Mr.
De Blois, was as follows : About eighteen months ago I
was asked to make an investigation and report on a case
of boiler-furnace explosion. There were two boilers con-
nected through a breeching to a brick stack, and both
were hand fired. This fact is of some importance. When
both were under steam firing was light and no trouble was
experienced. To save fuel it was decided to try to use
only one of the boilers at a time, holding the other in
reserve, and cold. The fuel used was bituminous run-of-
mine, with an occasional addition of wood shavings and
sticks. A pile of shavings had stood on the boiler-room
floor about ten feet from, and opposite to, the first boiler.
On one occasion there had been an explosion, and flame
had leapt across the boiler-room floor and had set fire to
the pile of shavings. On the latest occasion, coal only
being used as fuel, the fireman had covered the fire with
a layer of rather fine coal. A little later he opened the
door, and finding the fire deadened, stirred it with a poker
or slice bar. Immediately, there was an explosion. The
fireman was thrown across the room and was badly
burned.
The manager of the plant argued that the cause could
not be poor draft due to insufficient stack capacity, as this
particular boiler installation had been in use for about
twenty years and furnace explosions had been a recent
experience. On examining the settings I found clean-out
doors in the rear which could not he closed tightly (one
could see about three-eighths of an inch of red light
through the opening of the door of the live boiler) ; several
large cracks in the brick walls; unnecessarily large holes
in the walls where the water-gage connections and other
pipes entered; open joints and empty rivet holes in the
breeching: front doors not fitting closely. I advised that
all setting leaks be stopped and the results noted. I
heard of no further trouble. On reading Mr. De Blois'
letter I called up the manager of the plant, and he told
me that he had had the leaks stopped and that while there
were little puffs or explosions now and then, they were
neither as severe nor as frequent as they had been. Other
running conditions were about the same as before.
I have said that the fact that the boilers were hand-fired
was of some importance; it shows that explosions are not
characteristic of stokers. The stoker was not necessarily
at fault.
It is interesting to note that in this, as in Mr. De Blois'
case, one boiler only was being operated. In this case it
will be seen that there was no blast tuyere to become
obstructed, but there was what amounted to the same
thing — heavy firing with a close-lying coal, which ob-
structed the air passages through the grate and fire ; and
insufficient draft to pull air through the fire. There was
also enough air leakage through the settings to make an
explosive mixture with the CO and other gases generated,
and there was sufficient local heat at times to fire the ex-
plosive mixture.
Arthur Scrivenor.
Richmond. Va.
lEir&Il&.E'gpiag* (GtpavifiilrXjpaim B©s°e
When the crankpin of our ammonia compressor worked
loose we decided to remove it, enlarge the hole in the
crank and shrink in a new pin.
To do the job cheaply and quickly a 1%-in. shaft, 28 in.
long, was threaded on one end with 30 threads to the
Improvised Boring Bar
inch. A %-in. hole was drilled through the shaft to
carry the cutting tool, the latter being held by a setscrew.
Two 4x4-in. wood blocks, each 2 ft. long, were clamped to
the crank and each had a bearing for carrying the shaft
of the small boring bar. The arrangement is shown
herewith.
J. H. Cunningham.
Toledo, Ohio.
654
r 0 AY E It
Vol. 41, No. 19
Grit sua ftj&e Feed=Water Mefteir
Recently, the writer experienced considerable trouble
with a Kennedy-type water meter. On opening it con-
able line coal grit was found. The puzzle was, how
did it get there? The source of supply had not been
difficulty had never arisen before.
The overflow pipe from the injector had, temporarily,
been put to discharge near the coal bin, and this pipe
lames got covered over with coal when the bunkers
were full. In this particular style of injector, a vertical
one handling 23,000 pounds of water per hour, unless the
correct amount of water is put on to suit the steam, a
considerable suction can be felt at the overflow pipe,
My due to the cheek valve on the combining nozzle
not seating tightly, so that it drew quite a little coal dust
up the overflow pipe, discharging it into the feed line
and meter.
E. E. Pearce.
Rochdale. England.
:*:
lEatfSMaeiace of Aslh Coiraftesafc
I read with interest Mr. Ellis' letter, "Influence of Ash
Content of Coal," in the Nor. 3 issue.
High ash certainly cuts down furnace efficiency; on
that point there is no argument. Mr. Ellis states that
"coal apparently follows a straight-line characteristic as
regards its value on a basis of its ash content, assuming
the same character of coal." If by "same character" Mr.
Ellis means any general class such as anthracite, semi-
anthracite, semibituminous or bituminous, I take ex-
ception to his statement.
For a given coa1 I wiH concede the straight-line char-
acteristic, but I do not see how one characteristic can be
applied to all coals of the same character. For instance,
in anthracites the heat of combustible or ash-free heat-
ing value, as it is sometimes called, vanes from 14,400 to
15,200 B.t.u. With 15 per cent, ash, the B.t.u. dry in
these limiting conditions is 12,240 and 12,920, respec-
tively, a variation of 680 B.t.u. per lb. Ou this basis, it
would appear to be advisable not only to keep the ash
down, but to buy heat and not to accept the absence of
ash as an indication of high heat. Low ash may or may
not indicate high heat. The calorimeter answers that.
The formula at the end of the letter would, perhaps,
have been better understood if an example had been
worked out. As it stands, the '"value of coal" increases
numerically as the ash content increases, which is just the
reverse of what Mr. Ellis stated. For instance, take a
coal having an ash-free value of 15,000 B.t.u. and assume
that two subsequent shipments show 10 per cent, and
20 per cent, ash, respectively. Assume the price delivered
to be $3.50 per ton. The B.t.u. of the first shipment are
13,500 and of the second shipment, 12,000.
The value of the first shipment by the formula is then
350 350
13,500 — (13,500 X 1.5 X 0.10)
350
13,500 — 2025
11,4T5
= 0.0305
The second shipment shows a value of
350
350
12,000 — (12,000 X 1.5 X 0.20) 12,000
3000
From this it appears that the worse the coal, the higher
its value, as given by the formula. If it is correct, will
Mr. Ellis state how mmh better he regards the first ship-
ment than the last, based on the figures given by the for-
mula ?
Carletox W. Hubbard.
Brooklyn. X. Y.
)tises
)asctiassa©ira
Gasoline Engine Run* ox Natural Gas
We purchased a gasoline engine that was taken out of
a wrecked automobile. It is a 5x5-in. six-cylinder en-
gine rated at 60 hp. when running at 1000 r.p.m. We
are repairing this motor and intend to connect it through
a flexible coupling to a TSO-r.p.m., 17%-kw. generator
to furnish power for our after-midnight load. The en-
gine will be operated with natural gas and the speed
controlled by a flyball governor mounted on the fan
shaft and connected with levers and rods to butterfly
valves in the air and gas intakes.
Have any readers of Power had practical experience
with this type of engine operated on natural gas? If so,
I should be glad to have suggestions as to how they have
overcome the speed-governing problem, also as to what
proportion of power the engines developed with natural
gas in comparison with gasoline.
Erwiss Gawthrop.
Pittsburgh, Penn. v
Loose Craxk Disk
Can any of the readers of Power suggest some means
of tightening a loose crank disk on a large high-speed
engine without removing it? The disk was shrunk on
Keys tight fit at
sides but not at
top and bottom
Shaft not beaded
here
Details of Craxk Disk
the shaft about three months ago, after being care-
fully calipered and fitted by a man thoroughly experi-
enced in such work, but* in a few weeks it was appar
ently as loose as the one it replaced.
M. A. Jensen.
Nebraska City, Neb.
May 11. 1915 POWER
- „„„„ mini nuuiiii iiiiniiiniiiiii m» nimuium minim nm mm inn
G55
■i.iii; .i.l.i .M :.: 11:1
.'. .
Merries of Gemieml Mfeirestt
mm mi mi mm mm n limn inmm
Effect of Inside Lap— What is the effect of adding inside
lap to a slide valve?
J. W. D.
By adding inside lap the exhaust port is closed earlier,
thereby resulting in higher compression of the exhaust.
Corrosion of Steel Uptake— What would cause our steel
stack and uptake to corrode more rapidly than formerly?
N. R.
Other things being equal, more rapid corrosion would
take place from use of fuel containing more moisture or more
sulphur, or from introduction of more moisture with the air
supply to the furnace.
in | milium ii miiiiii n mi iinm i mum in iiunnmi nn linn iinmiiiini nm n nuillll
trisodium phosphate, dextrine or starch, and a tannin com-
pound such as mangrove bark, cutch or catechu. These ma-
terials are intimately united by thorough digestion, dried,
finely powdered, well mixed and readily soluble in water.
The compound must show on analysis at least 76 per cent,
of anhydrous sodium carbonate (Na.COj), 10 per cent, of
trisodium phosphate (NasPOJSH^O), 1 per cent, of starch, and
sufficient cutch to yield 2 per cent, of tannic acid, the re-
mainder consisting of water and such impurities as are com-
mon to the ingredients.
Slope for Drainage of Boiler to Blowoff — How much should
the rear end of a return-tubular boiler be set lower than the
front end for drainage toward the blowoff?
F. W. S.
Sufficient slope for drainage is usually obtainable for
boilers 16 to IS ft. long by setting the blowoff end about 2 in.
lower than the front end.
Quality of Boiler-Feed Water— What proportion of scale-
forming substances may be contained by a water to be con-
sidered as good or poor boiler-feed water?
L. G. N.
Water containing S to 10 grains of boiler-incrusting sub-
stances per gallon may be considered as good, while those
containing 15 to 20 grains or more may be regarded as poor.
IT. S. Navy Composition Metal— What is the U. S. Navy
composition or steam metal?
J. M. C.
This is a composition metal consisting of 88 per cent, of
copper, 10 per cent, of tin and 2 per cent, of zinc. Its tensile
strength is about 32,000 lb. per sq.in. and its elongation about
25 per cent. On account of its strength and toughness this
composition is considered superior for valves, flanges and
other boiler accessories.
Danger to Cylinder from Sudden Overloading — Does over-
loading a cutoff engine have any tendency to blow out a cyl-
inder head?
G. M. S.
In case of overloading, the higher velocity of steam in the
steam pipes and passages has a tendency to suddenly sweep
into the cylinder any accumulations of condensation and
thereby endanger the cylinder and its head to rupture from
presence of water in the cylinder.
Receiver of Returns Should Be Vented — Where a low-
pressure heating system is supplied with live steam passed
through a reducing valve and there is no vacuum pump on
the returns, is it necessary to discharge the returns either to
an open tank or into the atmosphere?
M. J. N.
Where the piping is properly arranged for drainage the
returns may be collected in a closed receiver with an auto-
matic air-relief valve, though it is better to supply the re-
ceiver with an air vent that is always in communication with
the atmosphere.
Use of Iron in Place of Copper Feed-Water Tubes — A
closed feed-water heater now fitted with copper tubes is
capable of warming a uniform supply of boiler-feed water
from 50 to 190 deg. F. To what temperature would the feed
water be heated, using the same number and size of iron
tubes?
J. H. B.
By the use of iron in place of copper tubes the rate of
heat transmission would be about two-thirds as great as with
copper tubes and the temperature of the water would In-
raised to about
50 + § of (190 — 50)
or approximately to 143 deg. F.
Savins from Higher Evaporation per Pound of Coal — What
percentage of fuel is saved with an equivalent evaporation
of 9.5 lb. of water from and at 212 deg. F. per lb. of coal over
an equivalent evaporation of S lb. of water per lb. of coal?
L. S. F.
With an evaporation of 9.5 lb. of water per pound of coal
1
each pound of water requires of a pound of coal. With an
9.5
evaporation of S lb. of water per pound of coal each pound
of water requires - of a pound of coal. Therefore, when the
S
evaporation is at the rate of 9.5 of water per pound of coal.
_ lb lb of coal is saved for each pound of water evap-
8 ' 9.5
orated and the saving amounts to
Omission of Low-Down Tubes in Return-Tubulnr Boilers —
In return-tubular boilers, why is not the space generally uti-
lized for tubes on each side of manholes and handholes in
the lower part of the flue sheets?
L. G. J.
Tubes placed low down in the flue sheets are not favorably
located for receiving the flow of the gases from the combus-
tion chamber and are thus of little value as heating surfaces.
By their presence in the lower part of the boiler they not only
displace a substantial amount of water which should be pres-
ent to absorb the direct heat of the fire, but also impede
circulation in a part of the boiler where it is most needed.
15. 7S per cent.
U. S. Navy Standard Boiler Compound — What is the com-
osition of U. S. Navy standard boiler compound?
A. N. I.
This compound consists of calcined sodium carbonate, that is,
Sine of Safety Valve for Compressed-Air Tank — What size
of pop safety valve should be used for a compressed-air tank
supplied from a compressor having a rated maximum capacity
of 130 cu.ft. of free air per min. compressed to 100 lb. per sq.in.
gage pressure?
P. E. C.
The safety-valve capacity should be 25 per cent, in excess
of the rated maximum capacity of the compressor, or
130 + 25 per cent, of 130 = 162.5 cu.ft. per min.
and the size of valve required may be determined from the
formula,
Q
Q = 28 PD1, or D = —
28 P 1
in which
Q = Discharging capacity of the valve in cubic feet of
free air per minute = 162.5 cu.ft.;
D = Size of valve in inches;
P = Absolute pressure of air relieved by the valve =
100 + 14.7 or 114.7;
1 _ Lift of valve, which for standard pop valves may be
By substituting in the formula and solving for D,
1 6 - S
D = _ = 1.25
28 X 114.7 X — D
31
safety salve should be used.
656
POWER
Vol. 41, No. 19
Tlh© IEHecforaic TiracftaoEa ELle^-sift©!?*
Elevators may be classified first according to the driving
power employed, which gives three principal classes, namely,
steam-driven, hydraulic and electric elevators.
The first class is now practically obsolete. There are, of
course, a few of them still running, but there are no new
installations.
Hydraulic elevators may be divided into several groups.
depending upon the method in which the hydraulic power is
led. Some of these types are: The horizontal, rope
i; the vertical, rope geared; and the plunger, which is
connected. The plunger type practically superseded
other types of hydraulic elevators during the period of 1901
to 1907, but has itself been almost entirely superseded by the
1 to 1 gearless electric-traction type.
Without considering in detail the technical features of the
plunger elevator, the principal reasons for this change may
be summarized in its comparison with the gearless traction
type as follows:
1. Higher initial cost of plunger installation.
2. Larger amount of total space in the building occupied
by the machinery.
3. Lower car mileage and consequently more elevators
required for the same service.
4. Higher power consumption.
As to the location of the electric elevator, this is prefer-
ably directly over the hatchway, an arrangement which gives
the best traction, least amount of ropes, minimum space
required, longer rope life and higher efficiency.
The roping is extremely simple, usually six ropes of % -in.
diameter being used. The material is soft steel and in actual
installations there is generally a safety factor of not less
than 12. Each rope is provided with a self-adjusting rope
hitch of the ball-and-socket type, which, owing to gradual
creeping, prevents any excessive twisting stress and relieves
the usual bending stresses at the hitch, caused by vibration.
A traction machine is arranged so that in case of overrun
at the terminals either the car or the counterweight strikes
an oil buffer, thereby reducing the traction sufficiently to
prevent further motion of the car, e\'2n if the motor keeps on
running. The car buffer is of the spring-return type and is
mounted in the bottom of the pit.
The counterweight equals the weight of the car and usu-
ally about 40 per cent, of the maximum load. If we consider
an elevator of 2500 lb. lifting capacity, 40 per cent, of this
equals 1000 lb. (the overbalance) and this represents about six
or seven persons. With such a condition of loading it is ap-
parent that there is no net load to be lifted and, therefore, the
only power required is for acceleration and to overcome fric-
tion and electrical losses.
ROPE COMPENSATION
It is obvious that with a high-rise elevator the variation in
the net load on the elevator machine due to the shifting of
the weight of the hoisting ropes from one side to the other
as the car moves up and down would be excessive if this
was not compensated for. This compensation is usually ob-
tained by means of chains or ropes attached to the car and
counterweight and running down the hatch in a loop. The
weight per foot of these compensating ropes is such that, to-
gether with the electric cables that lead to the car, they com-
pensate fully the weight of the hoisting ropes for all positions
of the car.
For all high-speed, high-rise elevators compensating ropes
are used and in the pit a tension device is provided for the
compensating ropes. For moderate rises and comparatively
low speeds, chains are used instead of ropes.
DRIVING MOTOR
The motor is of the slow-speed type, generally having
six poles and provided with a shunt field only. The armature
is series wound with conductors of rectangular cross-section
in order to get in the maximum amount of copper. With a
36-in. driving sheave, a car speed of 600 ft. per min. corre-
sponds to 63.5 r.p.m. of the motor armature.
For a considerable time it was considered that such a slow-
speed motor delivering around 35 hp. would have an exceed-
ingly low efficiency, but this is not the case. On the contrary,
it has been demonstrated that a motor with this low speed can
be designed to have just as high efficiencies as any high-speed
motor.
Passing now to the different parts of the hoisting engine,
the driving sheave is mostly 36 in. diameter, is cast integral
with the brake wheel, and is bolted to the armature sleeve
or spider. Circular rope grooves are employed. The mag-
•Excerpts from an address of David Linquist, chief engi-
neer of the Otis Elevator Co. before the New York Section of
the American Society of Mechanical Engineers.
net brake is of the shoe type, usually provided with a series
winding for quick release and a shunt winding for holding.
The brake shoes are lined with fabricated asbestos. The
gradual and soft application of the brake is obtained by
magnetic retardation of the magnet cores. The brake shoes
used to be lined with leather, but after exhaustive tests of a
number of different braking materials it was found that a
certain kind of fabricated asbestos was the most suitable, its
particular characteristics being that the friction between the
lining and the brake wheel is constant at all times.
Elevators of the gearless traction type have been for some
time equipped with ball or roller bearings. These are used
for both the main motor and the rope sheaves. This was done
primarily to gain space, because it is readily apparent that
these anti-friction hearings take up much less room than the
plain solid bearings. Personally I consider ball bearings su-
perior to roller bearings for elevator machines. With roller
bearings slightly out of alignment, even though this be in-
sufficient to set up destructive strains, the friction will be
increased materially. As a matter of fact, actual tests have
shown that friction induced in this manner can readily be in
excess of the friction in a plain bearing. Ball bearings are'
capable of resisting a certain amount of end thrust, which in
the case of these traction machines is sufficient to take care of
the "float" of the armature, caused partly from magnetic ac-
tion and partly by the action of the hoisting ropes. Roller
bearings will permit of no end thrust at all, and therefore,
when they are used additional means must be provided to take
care of this.
It is necessary, of course, to provide some lubrication in a
ball bearing so as to prevent cutting, particularly of the cage:
therefore, grease is provided, which will stay in the bearing.
Furthermore, grease is most efficient in ball bearings for
elevator machinery to prevent corrosion of the balls and races.
A little rusty speck on either the race or a ball will soon de-
stroy the bearing; hence these bearings must be usually well
protected. If the grease is wiped out and the bearings run
perfectly dry, the apparent friction losses will have been re-
duced to about one-fifth of that with lubrication.
SPEED CONTROL
Speed variation is obtained partly by field regulation and
partly by series and bypass resistance in the armature cir-
cuit. The field regulation is usually capable of reducing the
speed down to 60 or 40 per cent, of full speed, and further
reduction is obtained by resistance control, as previously men-
tioned.
The combination of Doth methods is necessary to obtain
sufficiently slow speed — about 60 ft. per min. This slow-speed
car is required to make accurate stops both at intermediate
and terminal landings and also in order to be able to make
a very short travel or to "inch up or down to the landing."
In connection with the regular operating features of the
control apparatus, there are also a number of other features
introduced for safety. Some of these are:
1. Automatic return of car switch to off position.
2. Automatic stopping switch on car for stopping at ter-
minal landings.
3. Final cutout limit switches in hatchway, operating in-
dependently of the automatic stopping switch.
4. Automatic stopping of elevator in case of over-speed by
means of an electric contact operated by a centrifugal gov-
ernor which will apply the electromechanical-brake and dy-
namo-brake effect on the armature, and, finally, the electric
safety on the car.
5. Oil buffers, as previously mentioned, are capable of
independently stopping the fully loaded car when descending
at 50 per cent, excess speed without discomfort to the pas-
sengers.
6. Regulation of the shunt field by centrifugal governor
to maintain constant full speed with variable loads.
7. For high-rise elevators the use of a retarding and
latching device.
LOADS AND SPEEDS
Gearless traction machines utilizing 1 to 1 or 2 to 1 rop-
ing have been built for loads varying from 2000 lb. up to 11,000
lb. at car speeds from 350 to 700 ft. per min. Of these duties
the most generally used for the modern high office building,
utilizing 1 to 1 roping, is about 2500 lb. at 600 or 700 ft. per
min., although in many instances a load of 2500 lb. at 500 or
550 ft. per min. is suitable. The high rise elevators in the
Wroolworth Building run at a speed of 700 ft. per min. In the
new Equitable Building certain of the elevators are arranged
to run a portion of their travel on express service at a speed
of 650 ft. per min., and the remainder of their travel on local
service at 550 ft. per min. The change in car speed is auto-
matically accomplished at the point where the service
changes.
May 11, 1915
imi w e i;
$51
For more moderate speeds and also for the heavier loads
2 to 1 roping is utilized, which retains the same safety feat-
ures and general characteristics as in the 1 to 1.
The traction principle is also applicable to elevator ma-
chines employing moderately high-speed motors with some
form of gearing between the motor and the driving sheave.
This type of machine is most suitable where lighter ca-
pacities are involved or where the service conditions are not
■ ere. Under these conditions the power consumed will be
■ omparatively light on account of the small mileage, and
hence the more expensive gearless machine with its reduced
power consumption may not he necessary.
Two types of geared machines have been developed — one
employing worm gear and the other herring-bone gear re-
ion. Of these the worm gear is suitable for the slow or
more moderate speeds and is extensively used for this pur-
pose. The machine with herring-bone gear reduction is not
Buitable for slow car speeds on account of the difficulty in ob-
taining sufficient speed reduction. It is undoubtedly more effi-
than worm gearing, and it has been used with some
success in connection with quite high-speed elevators. The
fact that the herring-bone gear has been used for these high
speeds does not mean that it is to be considered equal to the
gearless machine, with which it cannot compare as to oper-
ating features and power consumption. The worm gear has
inherently the least tendency to vibrate, but the herring-bone
gear is generally more efficient.
The maximum efficiency of the high-speed motor used in
connection with the geared machine may be practically as
high as that of the gearless. but the efficiency at lighter
loads, which is the most prevalent running condition, is
lower; hence, the high-speed motor is at a disadvantage.
Equal amounts of field regulation may be applied to both
types.
For high speeds it may be taken that under the best con-
ditions the gearing has a loss of about 10 per cent.
ELECTRO-MECHANICAL SAFETY DEVICES
1. The safety should be so arranged that the application
of a predetermined but definite light retarding force will stop
the car and net load without shock in case the hoisting ropes
are intact.
2. The safety device should be so arranged that the ap-
plication of a predetermined definite strong retarding force
will gradually bring the car and maximum load to rest in
the case of a free falling car.
3. The light retarding force should be immediately ap-
plied, preferably by means of a centrifugal governor, in case
the car should attain excessive speed in either direction.
4. It should be possible to immediately apply the light
retarding force from within the car when desired.
5. The light retarding force should be applied automati-
eallyin case of overrun at the upper or lower terminals, and
i e arranged not to interfere with the starting of the car in
;he opposite direction.
6. The strong retarding force should start to apply the in-
stant the hoist ropes part, independent of the speed of the
car and counterweight. In safe lifts a strong retarding force
should be automatically applied independent of the parting of
the hoisting ropes at a definite speed which should be higher
than the speed at which the light retarding force is applied.
7. A tripping governor should not be necessary to apply
the strong retarding force.
8. The releasing carrier, even though improperly adjusted,
should not prevent the application of a strong retarding force
to the car in case the ropes parted.
9. The principal actuating parts of the safety should be
made to move automatically at frequent intervals, in order to
prevent them from clogging up or corroding together. This
motion of the actuating parts need only lie very small to give
the desired results, but some motion is necessary to secure
dependable action of the safety.
The light retarding force is obtained by one helical steel
spring forcing the curved wedges between the rollers of the
safety jaw. When the car is in service this spring is held
under compression by means of an electromagnet.
DISCUSSK 'X
Some questions were asked with reference to the rope
strains. In reply Mr. Linquist stated that under ordinary
conditions the apparent safety factor with the load at rest
was never less than 12. This did not take into account the
additional stress due to acceleration and bending of the rope,
which would make the real safety factor hardly over 8.
As to whether anything had been done with reference to
the employment of alternating current in electric elevator
service, the speaker replied that, up to the present time no
alternating-current elevators have been put on the market
of the direct-connected or gearless traction type. Those
in use are of the geared type, for speeds up to 350 ft. per
min. approximately. For 250 to 300 ft., two motors are em-
ployed, with a speed variation of from 1 to 3 down to 1 to
4; in other words, the reduction of speed is to 5 or V4- The
change in speed is obtained by rearrranging the connections
of the motor in such way as to change from a small number
of poles giving the high speed to a large .-.umber of poles
giving the slow speed.
With reference to the smooth application of the brake, no
known method has been used for magnetically retarding an
alternating-current brake. There dashpot retardation has to
be employed, and in the majority of cases the brake-magnet
parts are inclosed in coil-type casings and the brake-magnet
ire formed partly i"r plungers to act as dashpots.
back to tiie question whether anything has been at-
tempted in tlie line of gearless alternating-current traction
machines. Mr. Linquist stated that last year he had built such
a machine, Half of the outfit consisted of an alternating-cur-
rent motor, and at the same time it acted as a motor it also
acted as a converter. The other half of the machine con-
sisted practically of a direct-current motor with a revolving
field with unusually large speed variation and speed regula-
tion. The machine was built and tested, and so far as the
speed control was concerned it was perfect. There was field
regulation from no speed up to full speed, and it was possible
to obtain any desired speed without resorting to resistance
control. On the other hand, the losses were comparatively
high and the efficiency was not very good.- As far as oper-
ation was concerned it was successful, but considering the
cost of operation and first cost, it was hardly a commercial
proposition, because as good rerults and perhaps better could
be obtained by changing the alternating current by means of
converters or motor-generator . ets into direct current and
operating direct-current elevators.
Elecftrf© Slhip Propualsaoim
Before a joint meeting of the Western Society of Engineers
and the American Institute of Electrical Engineers, W. L. R.
Emmet, of the General Electric Co., gave an interesting talk
on the above subject on the svening of Apr. 26. The devel-
opment of the high-speed turbine paved the way for electric
ship propulsion. Its application in this field had been long
foreseen. Mr. Curtis had worked for two or three years on
the problem, and since 1900 Mr. Emmet had spent much of
his time on the turbine. About six years ago he had first ap-
proached the Navy with a view to equipping battleships for
electric drive, but at about the same time the question of re-
duction gearing had been brought to the front and the Navy
had been impressed to the extent that the collier "Neptune"
was equipped with turbines and reducing gears. The ex-
cellent results obtained aroused interest in the general ques-
tion of reducing the speed between the turbine and the pro-
peller, and as a result Mr. Emmet secured the contract to
equip the "Jupiter" electrically. During the two years this
ship has been in service it has made a wonderful record. Re-
sults 20 per cent, better thai from any ship afloat have been
obtained, and the equipment is as good as new. The tur-
bines run regularly on a water rate of 11 lb. per shaft hp.-hr.,
which may be compared to 14 lb., the best obtainable from a
triple-expansion-engine-driven vessel. Naturally, electric pro-
pulsion gained in favor, and about a year ago it began to lie
thought of seriously for battleships. As the advantages of
the electric drive increase with the power required. Mr. Em-
met bad been particularly anxicus to equip a battleship, and
only withil. the last few days the contract for the "Cali-
fornia" had been closed. An estimate on the cost of install-
ing electric drive showed that a saving of $160,000 would be
effected over the cost of the turbine equipment that had been
previously planned. In these large powers all sorts of com-
plications arise when the turbines drive the - propellers di-
rectly or through reduction gearing. With the latter the
power must be divided up between a large number of units,
as there is a limit to the size and capacity of individual
beyond which it would not be safe to pass. In ship:
where the turbines drive the propellers directly there must be
a compromise in speed. The turns made by the propellers are
much too high, aid tin- turbine runs at about a tenth of
the speed it ought to have to give the best results. Besides,
there is great complication of piping for high- and low-pres-
sure turbines, and as the pressure in some of this piping is
below the atmosphere. :ir leaks are liable to develop and
lower the efficiency by reducing the vacuum. On the other
hand, with the modern electric drive the loss cannot exceed 8
per cent. The apparatus is design.-, 1 so that practically :i
stant water rate is maintained for all loads.
In the "Lusitania." with a speed of ISO r.p.m. the propellc-
efficiency is 62 per cent. The turbines for the "California"
will have a speed of l'l'i" r.p.m. and deliver to the generato
7.". per tent, of the available energy in the steam. In the
658
r 0 W E E
Vol. 41, No. 19
latter the turbines will be simple, compacl machines, while
enormous. By dropping the
propellei speed of the "Pennsylvania" from 222 to 160 r.p.m.,
the efficiency would be increased S per cent., which would
just counterbalance the loss by electric propulsion. Compar-
ing the present equipment with an electrically propelled
"Pennsylvania.'' the efficiencies would bear a ratio of about
03 to 73 per cent.
tigating the possibilities of reduction gearing held
back electric propulsion; Parsons had condemned the latter
and favored gears. Reduction gearing has proven successful
on small ships running at moderate speeds. As the speed of
the vessel increases, however, the ratio of reduction between
turbine and propeller speeds becomes greater and the gear
problem is more difficult. The Genera! Electric Co. had be-
come interested in gearing and developed a system which was
installed on tin...- freighters equipped with turbines. These
gears may be applied to cases where electric propulsion is
bailed, but in the favorable cases the speaker could not im-
agine any arrangement of gears which would be anywhere
near as good as electric drive.
Electric propulsion is to have a wide field of application.
The company had recently figured on two large Russian
cruisers and on a number for our own navy. Mr. Emmet
stated that he could reequip the "Lusitania" and save $150,-
000 per year in the cost of coal. Electric drive for liners so
far exceeds engines that the equipment would pay for itself
in one or two years.
Slides were thrown on the screen showing the 20,000-ton
collier "Jupiter" and its power-plant equipment. At 15 knots
the vessel requires 7000 hp. The generator is of simple and
rugged construction and is not restricted as to voltage or
frequency. It has a capacity very little greater than required
by the motors, so that even a short circuit would not re-
sult in much injury. The motors are of the three-phase in-
duction type, the stator having bar windings and the rotor a
definite wound design provided with external resistance to
be used when reversing. The governor is designed much like
a tachometer with a system of fulcrums which can be moved
in and out and varied through a wide range of speed.
For the "California" each turbine will have a maximum
capacity of IS, 000 shaft horsepower and on maximum load
will require 170.000 lb. of steam per hour. The vessel has a
displacement of 30,000 tons and a maximum speed of 22 knots,
and yet each of the two turbines driving it is only 14 ft.
long. The motors are 12 ft. in diameter by 11 ft. wide. Con-
sequently, the entire equipment occupies comparatively little
space, and the first impression would be that it was designed
for a tugboat or at least a vessel much smaller than the
"California." Even the auxiliaries will be electric driven, and
the only steam piping entering the engine room will be the
two leads for the main turbines.
The two turbines will develop a maximum of 36,000 hp.,
which is required to force the vessel to 22 knots. At 14 knots
7000 hp. is required. Performance charts showed that the
water rates will remain practically constant over a wide
range of speed. At 14 and 21 knots it was 10% lb. per shaft
hp.-hr., and for the range in speed between these two points
it remained between 10 and 11 lb. At a speed of 15 knots. 28%
in. of vacuum, no superheat and 190-lb. gage pressure, the
"Jupiter" showed a performance of 11 lb. per shaft hp.-hr.
These figures are exceptional and can be obtained only when
both the turbine and the propeller are running at their most
efficient speeds. By diminishing the excitation with the speed
the efficiency is maintained and at the same time the torque
is not reduced beyond that which is required. It is simply a
case of diminishing the excitation until the propellers are
turned at the right speed with the minimum amount of steam.
One of the big problems is reversing, but it has been met by
using high excitation while the change in direction is taking
place.
With the reduction gear the great problem has been to
equally distribute the load over the entire face of the gear.
With a rigid gear most of the load is applied near the ends
of the teeth. In the General Electric design this difficulty has
been overcome by a gear made up of separate disks which will
give sidewise and distribute the load over the surface.
A number of charts comparing the relative economy of
engine-driven vessels, geared turbines and electric propulsion
showed the following water rates per shaft horsepower-hour.
For the "Vespasian," with triple-expansion engines, the wa-
ter rate was 19 lb.; with geared turbines, 16 lb.; and with
electric drive, 12.7 lb. The "Cairngowan," with triple-ex-
pansion engines, developed a shaft horsepower-hour on 17.3
lb. of steam, and the "Cairnross," a sister ship with geared
turbines, on 14 lb. It was estimated that either vessel
equipped with electric drive would develop a shaft horse-
power-hour on 11.77 lb. of steam. The above figures tend to
prove the assertion made by Mr. Emmet that electric drive
over triple-expansion engines will reduce the water rate about
one-third.
In the discussion it was brought out that as induction
motors cannot run above synchronous speed, the propellers
cannot race. Even in a heavy sea, with the propellers en-
tirely out of water there is no vibration or any indication of
a change in sliced. As to the proper fields for reduction gear-
ing and electric drive. Mr. Emmet made the general state-
ment that in all ships requiring above 15,000 to 20,000 hp.,
< ing ould make a poor comparison. In vessels requiring
in. (mil hp. and less and running at a low speed, reduction gear-
ing would perhaps make the best showing. The field for elec-
tric drive is in large merchant ships and all battleships with
the exception of torpedo boats and destroyers, where re-
strictions in weight prohibit its use.
BS,©c©mitl Co^airtt Dec:
Digested by A. L. H. STREET
Duty to Guard Ash Piles — When the owner of a power
plant has knowingly permitted children to play about a pile
upon which hot ashes from the boilers are deposited, he is
under a legal duty to either maintain a guard or give suitable
warning to prevent injury to such children, according to a
decision of the United States Circuit Court of Appeals, for
the Sixth Circuit, in the case of O'Donnell vs. Escanaba Man-
ufacturing Co., 212 "Federal Reporter," 64S. In this case
judgment was affirmed in favor of a ten-year old girl who
was burned in undertaking to walk over a pile of hot ashes.
A Mandatory Statute — A law enacted by the Oregon Legis-
lature in 1011, to promote the safety of electricians, requires
dangerous wires to be completely insulated, prohibits inter-
mingling of dead and live wires, requires the supports of
live wires to be so designated that the presence of such wires
shall be instantly apparent, and requires such wires to be so
strung as not to endanger repairmen working near them, etc.
Applying this law to an action for the death of a lineman
who was electrocuted while working on a pole which sup-
ported uninsulated wires, the Oregon Supreme Court lately
decided, in the case of McClaugherty vs. Rogue River Electric
Co., 140 "Pacific Reporter," 64, that an employing electric
company cannot excuse liability for failing to comply with
such statutory requirements, by installing switches in such
a location that electric current can be shut off while work
is being done. The court says: "The requirements of the
statute as to the safeguards enumerated are positive and
mandatory. There are no alternatives."
Kight to Enjoin Construction of Dam — That suit does not
lie to enjoin the construction of a power dam when it is
being erected under legislative authority is the gist of the
decision of the North Carolina Supreme Court in the case of
Tucker & Carter Rope Co. vs. Southern Aluminum Co., 81
"Southeastern Reporter," 771. The court said: "The defend-
ant's dam is being constructed under express legislative
authority, and is a lawful structure per se, and cannot be
restrained as a public or private nuisance. If, in the course
of its lawful operation, it may inflict injury upon the plaintiff,
it is amply able to respond in damages. Whether the relief
to which the plaintiff shall be entitled will be the recovery
of damages or the abatement of the height of the dam is a
matter which will arise when the facts are found; but cer-
tainly the courts will not stop the construction of the dam
more than IS months before its completion upon the allegation
of the plaintiff, which is denied in the answer, that it will
injure its property if built to the height that is proposed."
Effect of Washington Public Service Commission Law — Afl
construed by the Washington Supreme Court in the recent
case of Tacoma Railway & Power Co. vs. City of Tacoma, 140
"Pacific Reporter," 565, the Public Service Commission law
of that state "deals only with the questions of safety, effi-
ciency, rates and equality of public service. The power to
grant a limited franchise is still in the city. No power was
given to the public-service commission to grant, modify, or
abrogate franchises or contracts arising out of franchises,
except in regard to rates and the regulation of service in
respect to its safety, efficiency and equality. It was not the
purpose of the act to enlarge franchises, or to require the
performance of acts being exercised under a franchise which
could not be legally exercised, or for a longer period than
such acts could be legally exercised." Hence, it is found that
the law did not abrogate a condition in an electric franchise
previously granted by the City of Tacoma to an electric
company, providing that it should not furnish electricity for
lighting purposes.
May 11, 1915
PCMY E i;
659
(Cams© ©If T-oairlbaiae FaaHuaipe
The "Journal of Electricity, Power and Oas" of Apr. 17
contains the finding of the board which investigated the
recent turbine failures at the Fruitville plant of the Southern
Pacific Co.
It appears that the trouble began by one of the turbines
losing six blades of the impulse element. The load waa
shifted to the other turbine, but on the following day practi-
cally all the intermediate blading of the second machine let
go. The first machine being open and under repair at this
time, the service was crippled for several hours. Investiga-
tion showed the cause of the blade failure in the second ma-
chine to have been the rusting of the metal in which the
blades are secured. This permitted some of the blades to
come out and in turn rip out others, until the entire intei
mediate stage had been destroyed. It is believed that the
rusting resulted from leakage of .steam past the throttle when
the machine was stationar} II is very difficult to keep the
throttles absolutely tight, but arrangements have been made
so that in the future this leakage will exhaust to the at-
mosphere instead of into the turbine casing. Moreover, rust-
ing will be prevented by the introduction of brass lining
strips, which the makers are now recommending with this
type "f turbine.
or compressors and refraining from calking pipes or tighten
Ing up fittings while they are under pressure are gem
understood, but often disregarded. It is particularly danger-
ous to calk joints or tighten nuts or fittings under pressure.
Marry fatal accidents have been caused in this way.
However carefully a system is designed and installed, a
certain amount of liquid is likely to accumulate, and its pres-
ence in lire compressor is always a source of danger. The
"I", mus remedy is to provide a properly located relief valve of
sufficient capacity to permit the discharge of practically all
the liquid present before the piston reaches the end of its
stroke. There arc cases where considerable difficulty may
he experienced in equipping compressors with such devices.
but the greater safety gained is well worth the trouble.
Everj steam engine should be provided with a safety stop
wholl] independent "' the ordinary governor. In case the
governor fails to work properly and the engine starts to
"race," the independent safety stop is sir], posed to operate as
soon as the speed exceeds a predetermined limit, shutting off
the steam, bringing the engine to a standstill, and preventing
the bursting of the flywheel and other serious consequence?..
Piston rings formerly caused considerable trouble, bit
ordinary snap ilntis are now used with satisfactory results,
so far- as accidents from this cause are concerned. — "Travel-
ers Standai d.'
H<ce Plg&m\{ts Hot Him&Eim^iira© fs^oam
A<scadl©irafts
The fact that the refrigerating industry in which chem-
ic nls and highly compressed gases are used in connection
with tanks, piping and moving machinery is not immune from
accidents is attracting the attention of municipal authorities
to such an extent that regulations for installing and oper-
ating the plants have been drawn up and put into effect in
many localities. No doubt, these regulations will have to be
revised as experience is gained in their application, and in this
respect they may he expected to have a history similar to that
of analogous regulations applying to steam boilers. As in
almost every other industry, the majority of the accidents
that occur are avoidable, provided sound engineering prin-
ciples are followed in the design, installation and operation
of the plants. It follows, then, that the engineer who de-
signs the plant and the man who supervises the installation
should bear in mind the question of safety, and it is equally
important to place competent men in charge of the operation
of the plants, because the judgment and ability of the men
are exceedingly important factors in preventing accideirts. —
"Travelers Standard."
Ice~MlgiMimg| Flsinafts asa ftlh©
Tesftamijs a
wit? fox
It is customary to test a refrigerating system with air-
pressure before charging w.th ammonia. This should be care-
fully done by experienced men to avoid an explosion by the
ignition of the vapor from the lubricating oil, caused by tire
heat of compression.
A thin coating of lard oil should first be applied by hand
to the walls of the compressor cylinders and the compressor
allowed to run until the pressure reaches 100 lb. or more.
It should then be stopped long enough to cool down, then
started up again and operated until forty or fifty pounds
of additional pressure is obtained, then stopped again. When
sufficiently cooled it should once more be started, but at
reduced speed, and stopped whenever the discharge pipe be-
comes hot enough to he uncomfortable to the hand. If these
precautions are taken there is little chance of an explosion
from internal causes during the test. The men should lie
kept away from the apparatus as much as possible, however,
as there is always a possibility that an accident may occur-
through the failure of an imperfect joint or from unforeseen
weakness in some other part.
Soinme Pir«;c®yaa&a<D>ias Hce=Pl.miraft
The operating engineer of a refrigerating plant should
remember that he is subject to many of the hazards that
are to be found in the ordinary power plant and also to some
additional ones. For example, in compressing air he should
never use a machine that has recently been used to compress
ammonia, and in opening gage-cocks he should stand at the
side rather than in front of the gage-glasses. Such precau-
tions as standing at the side rather than in front of cylinders
There are in the United States over 12,500 ice-making
plants, having an aggregate annual output of about twenty
million tons. This does not include the thousands of private
refrigerating plants in small restaurants, meat markets,
grocery stores and private dwellings. The principles of arti-
ficial refrigeration are being applied in more than 150 differ-
ent industries, including among others mining, paper making,
woolen and silk manufacturing, laundering, and cobacco man-
ufacturing.
JOSEPH G. GANNON
Joseph Charles Gannon, chief engineer of the Greenpoint
Hospital, Brooklyn, N. Y., died Apr. 17 from pneumonia. He
was 47 years of age and had long been a member of the Na-
tional Association of Stationary Engineers.
ANDREW J. WILSON
Andrew Joseph Wilson, manager of the Lynn C
Refrigeration Co., and a consulting engineer, died Apr. 18,
from heart failure. He was 39 years of age and had spent
twenty years in Toronto, Can., where his .reath took place.
John Sabin, who likes to recall that he is the man who
sold the first Bundy trap something more than a quarter
of a century ago, has been appointed general manager of the
Nashua Machine Co., the manufacturer of the trar
EMG1MEER1HG AFFAPi&S
The American lloiler Manufacturers' Association will hold
its 191E convention ai the Lawrence Hotel, Erie, Pens., on
June 21. 22 and 23. Among- other matters the convention
will consider the standardization of a uniform cost system
and of mater. ..1. workmanship and terms of payment clauses
in specifications. The committee on the -V. S. \\. E. I oiii
Code will report and ways and means will be discussed d
curing the adoption of the code in the several states. The
attendance of all boiler manufacturers in the On i ted Sta«.e:
and Canada is requested. Those expecting to be present should
notify the secretary. J. D. Farasey, East 37th St. and Eri
Railroad, Cleveland, i Ihio.
The National District Healing: Association will hold its
seventh annual convention on June 1, 2 and :\ at the Hotel
Sherman, Chicago. The following papers will be presented:
"Commercial End of the Heating Business,' bj C, i-' ' ■ ■hlman,
GGO
POWER
VoL 11, No. 19
Denver Gas & Electric Co.; "Operating Experience with
Bleeder Type Turbines," by F. W. Laas, chief engineer, Iowa
Railway & Light Co., Cedar Rapids, Iowa; "The Hot Water
Heating System at the Grand Central Terminal," by W. G.
Carlton, New York City; "A Pressure Study of a Steam Dis-
tribution System," by C. C. Wilcox, engineer, Hodenpyl Hardy
Co., Jackson, Mich.: and "Exhaust Steam vs. Live Steam for
Heating," by George W. Martin, New Tork Service Co., New
York City.
April, 1914. The subjects covered are: The Strength of I-
l earns in Flexure, by H. F. Moore; Coal Washing in Illinois,
by F. C. Lincoln; The Mortar-Making Qualities of Illinois
Sands, by C. C. Wiley; Tests of Bond between Concrete and
Steel, by D. A. Abrams; Magnetic and Other Properties of
Elei tioly tic Iron Melted in Vacuo, by T. D. Yensen; Acoustics
of Auditoriums, by F. R. Watson; and the Tractive Resistance
of a 28-Ton Electric Car, by H. H. Dunn.
ELEMENTARY ELECTRICITY AXD MAGNETISM. By W. S.
Franklin and Barry MacNutt. Published by the Mac-
Millan Co., New York. 1914. Size, 4%x7% in; 174 pages;
illustrated. Price, $1.25 net.
A simple and well-illustrated presentation of the prin-
ciples of electricity, studied from its effects rather than from
the theoretical standpoint. The pump analogy is used to ad-
\antage in describing electromotive force and resistance.
While the book is intended primarily for the student, its use-
fulness to the practical man might have been enhanced had
more of the illustrations been selected from modern com-
mercial apparatus.
HEAT ENGINEERING. By Arthur M. Greene, Jr.. Professor of
Mechanical Engineering, Rensselaer Polytechnic Insti-
tute. Published by the McGraw-Hill Book Co.. Inc.. New
York. Cloth; 462 pages; 6x9 in.; 198 illustrations. Price.
$4.
This volume is announced as a textbook of applied thermo-
dynamics for engineers and technical students. The first
chapter contains a brief review of the theory of thermody-
namics. Chapters follow on heat transmission, air compressors,
the steam engine, the steam turbine, condensing apparatus,
internal-combustion engines and refrigeration. Each chapter
is concluded by a series of topics and problems. The topics
consist of a series of questions relating to the text and the
problems (without answers) illustrate its use. The book is
decidedly unusual in its treatment of the steam boiler. The
combustion of fuel in boilers is briefly described in the sec-
tion relating to internal-combustion engines, but otherwise a
consideration of the steam boiler, its theory, design and per-
formance, is missing. As half of the book applies to.appara-
tus using steam, the omission seems unexplainable. With
this exception the book appears to present a useful outline
of applied thermodynamics.
ENGINEERING ECONOMICS. By John C. L. Fish. Professor
of Railroad Engineering, Leland Stanford, Jr., University.
Published by the McGraw-Hill Book Co., Inc., New Tork.
Cloth; 217 pages; 6x9 in. Price, $2.
The title of a book is sometimes descriptive of its contents.
Professor Fish's treatise, in spite of its title, does not at-
tempt to set forth laws of wealth peculiar to engineering,
but it does explain the factors on which depend the long-
run least cost of engineering structures. The book deals
mainly with the economic selection of the means of accom-
plishing engineering ends, and this selection is defined as the
choice based on the long-run least cost. The opening chap-
ters are devoted to the derivation of formulas for calculating
simple and compound interest and to an explanation of sink-
ing funds, capitalized value and other relevant financial terms.
The essential components of first cost, such as investigation,
promotion and construction expenses, are next outlined; and
scrap value, depreciation and amortization are defined. The
application of these terms is shown in a chapter on the ele-
ments of yearly cost of service. The method of figuring
amortization and interest charges is clearly and completely
handled, but the attention paid to operation and mainte-
nance expenses seems inadequately brief. No doubt, the
author emphasized the financial and accounting problems, be-
lieving that the engineer needed no information on material
and labor expenditures. The elements described are illus-
trated by fifteen numerical examples, four of which apply to
the power plant. A useful feature is the list of depreciation
rates accepted by various legal authorities, in which apear a
number of items of power-plant equipment. There are also
a number of references to published cost data and to esti-
mating methods used in designing engineering structures.
While the book seems to have been written chiefly for the
designing, it should prove useful to any engineer requiring r.
working knowledge of the principles underlying cost-.if-
operation calculations.
ENGINEERING EXPERIMENT STATION BULLETIX
Volume 10 of the "Bulletins of the Engineering Experiment
Station," University of Illinois, has recently come from the
press, bound in half-leather and containing reports of the
work at the experiment station from September, 1913, to
BUSSBJESS HTCMS
The M. W Kellogg Co., New York, has moved its offices
into larger quarters at 90 West St.
E. G. Calles Co.. Chicago, 111., has been appointed agent
for the S-C Regulator Co., Fostoria, Ohio, for the Chicago
territory.
The McClave-Brooks Co., Scranton, Penn., has opened a
Boston office in the Equitable Building, No. 202, in charge of
S. C. Smith, manager.
The Pittsburgh branch office of the Bristol Co., Waterburv,
Conn., has been moved from 1670 Frick Annex into better
quarters at S32 Frick Building. R. B. Anthony is district
manager.
The Wilson-Snyder Manufacturing Co. and the Wilson-
Snyder Centrifugal Pump Co., of Pittsburgh, Penn., have
opened a branch office at 52 Yanderbilt Ave., New York Citv,
in charge of A. H. Sherwood.
The general sales department of the Nashua Machine Co.
will hereafter be located in the principal office of the company,
in Nashua, X. H. A Boston office will be maintained for
Xew England business, in charge of E. M. Stevens, who has
been associated with the business for many years.
M. N. MacLaren, X'ew York manager of the Nordberg Manu-
facturing Co., of Milwaukee, Wis., builder of Corliss engines,
uniflow engines, poppet-valve engines, high-compression oil
es, air compressors, hoisting engines, blowing engines,
electric hoists, pumping engines, steam stamps, etc., announces
the removal on Apr. 26 of the New York office from 42 Broad-
way to the new Equitable Building, 120 Broadway.
The C. W. Hunt Co., Inc., owing to increasing business,
has moved its Xew York office from 45 Broadway, where it has
been for 2S years, to the new building of the Adams Express
Co., 61 Broadway. It will occupy a suite of offices on the
11th floor, which will give it much better facilities for
transacting business. The company is a large manufacturer
of coal-handling machinery, conveying machinery and small
motor trucks.
The Wright Manufacturing Co. (alarm water columns
Emergency and Victor steam traps. Cyclone exhaust heads),
the Austin Separator Co. (steam and oil separators), the Mur-
ray Specialty Mfg. Co. (Murray automatic boiler-feed regu-
lators) have moved from 55-59 Woodbridge St., West, to
larger and better quarters at 97-101 Woodbridge St.. West,
Detroit, Mich. The Murray Co. has just issued an attractive
catalog, which can be had on application to the new address.
The Bruce-Macbeth Engine Co., Cleveland, Ohio, has re-
cently made the following shipments: One 100-hp. natural-
gas engine to the Fedders Manufacturing Co., Buffalo, N. Y ;
one 350-hp. natural-gas entrine and Steam Process to the
Mansfield Milling Co., Mansfield, Ohio; one 130-hp. natural-gas
engine to the Galion Iron Works & Manufacturing Co., Galion,
Ohio: one 125-hp. natural-gas engine to the Setter Brothers
to., Cattaraugus, N. Y.; one 150-hp. natural-gas engine to the
.Dunn-Taft Co., Columbus, Ohio; one 150-hp. natural-gas engine
to the Fostoria Glass Co., Moundsville, W. Va.; two 90-hp
natural-gas engines to the Brookville Glass & Tile Co
Brookville, Penn.
Kerr Turbine Co.. Wellsville, X. Y., is distributing Bulletin
No. 51, "Economy Geared Turbines," which explains the great
advantages often obtained by interposing gears between
turbine and driven generator, pump, blower or pulley, and
also explains the new method by which Economy turbine
gears are so accurately hobbed that no grinding or'polishing
is necessary for finish. A copy of this bulletin will be sent
on request. Recent sales made by the Kerr Turbine Co
include the following: City of Atlantic Citv, N. J., IS, 000,000-
gal. Economy turbo-pump: City of Baltimore. 500-kw. Economy
turbo-generator; City of Williamsport. Penn., 425 hp. turbine
for driving a pump; City of Youngstown, Ohio, two 250-kw.
turbo-alternators; dredge "Columbia," Port of Portland, Ore.,
two 100o-hp. geared turbines; Swift & Co., Chicago, 3 turbine
units; Christian Moerlein Brewing Co., Cincinnati. 300-kw.
turbo-generator; Carnegie Steel Co., Farrell, Penn., 125-hp.
turbine: Jones & Laughlin Steel Co., Woodlawn. Penn., 325-hp.
turbine; National Tube Co.. Christy Park Works, McKeesport,
lenn^, 350-hp. turbine. Export orders include East Hull
Uas to., droves, England: Corporation Gas Works, Birkenhead,
England; and Armour de la Plata, Argentine.
X
The Flow of Steam from one vessel to another through an
orifice with parallel sides increases as the pressure difference
ses, down to 58 per cent, of the absolute initial pressure.
A greater pressure difference does not affect the velocity, even
though discharging into a perfect vacuum. For example,
steam at 100 lb. pressure will increase in velocity as the pres-
sure against which it discharges diminishes down to 58 lb.,
then the velocity of the flow will remain constant no matter
how much the receiver pressure may be reduced — even to a
perfect vacuum. Therefore, steam at approximately 25J lb.
discharging into the atmosphere has attained the maximum
velocity possible in such a nozzle, which is 14 70 ft. per sec,
because 5S per cent, of 25 J equals 14.7, or ordinary atmospheric
pressure.
Vol. 1 1
POWER
XKW YOB.K, MAY is, 1915
tc,
No. 20
PURPOSEFUL
ANECDOTES
AFTER my first year in charge of
l\. our power plant I was told by
the owner that my work was satisfac-
tory— that I would be retained at the
same salary.
The news, however, did not please me
much. I had hoped for a raise. Why
didn't I get it? Would I have to
work another year at the same salary?
The more I thought about it, the more peevish
I became, until I finally decided on a unique
plan for throwing up my job. I would revenge
myself by "heaping coals" of fire on the head
of the owner. I would prove that I'm "game."
I began by working up a written "process
system" that would enable my successor to
pick up the plant where I left off, without
difficulty.
I put down in black and white the peculiarities
of our grates, boilers, draft, etc., and the
method of firing that I believed to be best —
Position of ash doors, rate of feed of stokers,
speed of fans, method of cutting out boilers,
when to do it, method of cleaning, dangers —
.arimedi
M;
And other points that had given me trouble
during my year in charge.
But I found that my grouch was beginning to
leave. Writing about my plant made me
THINK. I began to wonder if, after all, my
methods were BEST. My interest increased.
I studied. I experimented. And as a result, I
learned that my old methods were NOT best,
and I began putting BETTER methods in
force.
I continued writing my process system, alter-
ing it wherever improvements in operation
were made, and at the end of six months I had
covered the entire plant. But I realized by
this time that it was not yet at its best — that
even better overall economy was possible and
should be attained. I saw that we needed a
little additional equipment and I could
PROVE it with actual figures.
So, instead of resigning, as I first intended to
do, I handed my process system to the owner,
told him what I had done and what I had
learned. I told him what was needed and
why, and I won my point.
I did not have to wait the year out for my
raise. TRY IT.
ill i iiiiiiiiiiiiiiiiiiiiiiMiiiiiiiiiiinii ilium i nullum i inn inn i.iiiiiin i i nun in u iiiiimiiiiiiiiiimin mil miiiiii miimuiii iiuunuiniiumimmiiinmiuimiii
662
POWER
Vol. 41, No. 20
Boiler PlsMmtt of Usuiomi Brewery
Thomas Wils
SYNOPSIS— An isolated boiler plant of 1500-hp.
capacity equipped with comp and ash-
handling systems. Boilers hare the tu w marine
settings, and special precautions have been taken
to ins,m a minimum loss of draft between tin
An uptodate boiler plant, unusually complete for its
size and containing the latest features in boiler-room
n. has recently been completed by the Otto F. Stifel
n Brewing Co., in St. Louis. The commercial life
of the old boiler plant was rapidly drawing to a close,
The new building is of fireproof construction through-
out, as it is made up of brick walls, concrete floor, tile
and concrete roof, steel sash and ventilators, and no wood
except the doors. The interior dimensions are 47x64 ft.
and the height from the floor to the roof trusses is 38 ft!
h is equipped with three 500-hp. vertical water-tube
boilers, and there is space for one more of the same size.
The boilers, shown in Fig. 1. now carry a pressure of
150 lb. gage, but eventually will supply steam at 175 lb.
pressure to the equipment of the new engine room. A
feature of the boilers is the marine-type setting recently
adopted in stationary work to reduce the radiation and
eliminate infiltration of air. It is made up of 4y2 in.
Fig. 1. Boileb House of the Union Brewing Co.
and the early intention of enlarging the brewery made
the new plant imperative. As a starter only the boiler
house was erected, across the street from the brewery
It is the intention to erect an engine room adjoining but
at present the old equipment, consisting of three engine-
driven ammonia compressors and two generating units,
is supplied with steam at 150 lb. pressure from the new
boiler house. The pipe supplying steam for the above
machines and for industrial uses in the brewery passes
through a tunnel under the street. At the delivery end
the supply is controlled by an electrically operated valve
oi circle" firebrick and 3 in. of asbestos fiber covered
by steel plate. The exterior furnace walls, made up of
9 m. of firebrick and 12 in. of common brick, are
protected by V4-in. asbestos board and the steel-plate
covering. This construction prevents leakage from the
sides, and as the stoker works under a ledge it is easy
to block off the air from the front.
Stokers of the chain-grate type were installed, having
an active width of 7 ft. 6 in., a length of 11 ft. 7 in and
an area of 8? sq.ft. To the 5000 sq.ft. of heatine surface
contained m each boiler, the above area bears a ratio of
May 18, L915
row e i;
663
1 to 57.5. This is somewhat higher than the usual 50
to 1, but in this particular ease the grate surface was
made less than the average lor the following reasons:
As furl had to he carted eight blocks, it was decided in
the interests of economy to use a high grade of Illinois
; __Breeching'
W-ll-S
ASH PIT--\c - U'-IO " -J
Fki. 2. TitAxsvEKNK Section of Boilei; Plant
reduction of .urate area was desirable and its installation
an e\ idence of good engineering.
An inspection of the drawings will show that special
precautions were taken to reduce to a minimum the loss
of draft between the stack ami the furnace. In (he first
place, under average conditions a boiler of the type in-
stalled shows a draft lo>> approximately only 0.2. This
is from the hoiler side of (he damper to the entrance from
tin' furnace. 'The low drop is partly due to the static
effect id' the hot gases rising in tin' first pass and dropping
in the second pass after being cooled by coming in
contact «itli the heating surface. Through three-wing
dampers the gases discharge directly to a rectangular
breeching built up from the floors and running straight
to the stack. The breeching tapers toward the farthest
hoiler, Imt at the stack is 5 ft. 'i in. wide and 0 ft. high,
giving an area, of 50 sq.ft. in round numbers. It is
made of tile, lirchriek lined, and has a run id' 51 ft.
The stack is one of the finest for its size in St. Louis
It vises 185 ft. above the boiler-room floor and has an
internal diameter of 7 ft. 6 in. The shell is made of a
special radial tile filled with reinforced concrete, and
for a height of TO ft. is lined with lirchriek. An air space
of 3 in., unfilled, separates the lining from the shell.
For a gas temperature ranging around 500 deg. and allow-
ing 100 Ih. of gas per horsepower, the stack is figured to
Fig. 3. Longitudinal Section Showing Gbneeal Arrangement
washed coal. Tl i i - quality of coal requires less grate
surface than an inferior grade as it contains less im-
purities, and as it is high in volatile more of it can he
burned per square foot of grate than coals containing
mere ash or higher in lixed carbon. For these reasons
and because an excellent stack had been provided, which
is capable of producing a strong draft over the fire, a
produce a draft of 1 in. of water at the base for the four
boilers and 1.1 for the three boilers now installed. For
higher temperatures the draft will he slightly greater.
While clean, the breeching should not cause a drop of
more than 0.1 in. ami the return from the breeching into
the stack 0.05 in. Taking the hoiler farthest from the
stack, interference by the gases from the two other boilers
664
P 0 W E R
Vol. 41, No. 20
will cause a drop of 0.1 in. — 0.05 for cadi boiler. The
right-angle turn of the gases in the breeching at the
outlet from the boiler will cause a loss of 0.05 in., the
damper another 0.U5 in., the boiler 0.2 in. and the right
Fig. 4. Paet of Ash-Removal System i.v Fbont of
Ashpits
boilers approaching the stark the draft over the fire will
be slightly higher, but with the three-wing dampers the
intensity can of course be varied to suit the load con-
ditions, thickness of fuel bed and the character of the
coal.
It may be of interest to check the relative areas of
stack, breeching and grate, and these will be compare, I
oil the basis of three boilers, as the fourth, when installed,
will in all probability be held as a reserve unit. With an
internal diameter of 7.5 ft., the stack has an area of
11.2 sq.ft., while the breeching, as previously stated.
has 50 sq.ft. The breeching, then, is a trifle larger than
the stack, as it should be, and its area bears a ratio to the
connected grate surface of 1 to 5. This conforms with
the average ratio adopted in recent practice. Each square
foot of sectional area in the stack is intended to serve
5.9. or nearly 6, sq.ft. of grate, and each square foot of
breeching 5.2 sq.ft. of grate. Per boiler horsepower, still
considering the three units, the stack has an area of
0.0294 sq.ft. and the breeching 0.0333 sq.ft.
Figs. 2 and 3 indicate the arrangement of the plant,
the layout and size of the steam piping, and the provisions
made for handling coal and ashes. A feature worthy of
notice is the walks, giving ready access to the top of the
boilers, the steam header and the screw conveyor over the
Bend at Which Steam Nozzle Is
Introduced
angle turn from the furnace up into the boiler, 0.05 in.
The various drops total 0.6 in., and deducting this loss
from 1.1 in. leaves a draft of 0.5 in. over the fire for the
farthest boiler. With the fourth boiler installed the
above draft would be reduced to about 0.35 in. For the
Fig.
6. The Receiving
Ashes
Tank for the
bunkers. As previously stated, coal is carted to the plant
and dumped from the yard into a hopper shown at the
right in Fig. 3. Provision has been made here for a
coal crusher, which may be installed at a future date.
From the hopper the coal slides into the boot of a bucket
May 18, 1915
POWE 1;
665
elevator and may be hoisted at the rate of 30 tons per
hour. At the top of the boiler room the coal is transferred
to a screw conveyor and may be dumped through any one
of three gates into a suspended Bteel bunker of 176 tun,-'
ty. A separate spout for each boiler carries the
coal to the hoppers of tin- stokers. All three stokers are
titric driven from a sliaft turned by a 5^-hp.
■©tor.
Ashes are removed by ;i vacuum system using a steam
nozzle to supply the motive power. As shown in Figs.
ind 6, tins consists of about 100 ft. of 8-in. chilled
east-iron pipe having walls 1 in. thick, a steam nozzle
and a tank to receive the ashes. The horizontal run in
front of the ashpits is close to 50 ft. and the rise about
43 ft. The nozzle is located in the basement at the
point where the pipe turns upward. Its location is shown
in Fig. 5. The photograph was taken before the steam
pipe leading to the nozzle had been fully covered. The
far end of the ash pipe is left open, and when steam is
tinned on, air is pulled through the pipe at high velocity.
Ashes raked from the pits into the pipe are carried along
with the current of air. ami when they pass the nozzle,
are positively forced up into the tank by the jet of steam.
Through a gate at the bottom of this tank the ashes are
loaded into wagons and carted away.
The system was designed to handle 200 lb. of ashes per
minute, or 6 tons per hour, with a steam pressure of
114 lb. at the nozzle. The nozzle is % in. diameter.
and at the above rate will discharge against atmospheric
pressure about 2000 lb. of steam per hour. Charging
22c. per 1000 lb. for steam, the cost for steam only per
ton of ashes removed would be 6.4c. In a plant of this
size additional labor should not be required to operate
the system. The charge to add per ton for depreciation,
interest on investment, etc., cannot be determined without
boiler and all equipment now installed, the total cost
will reduce to $40 per boiler horsepower.
Ruebel & Wells, consulting engineers, of St. Louis.
designed and erected the plant under the direction of
Phillip Scheuerman, general manager of the brewery.
One of the annoyances in a -team plant is the cracking
and working Loose from their metal -cat- of wooden
valve handles such as commonly used on water-column
Showing How the "Kantsplit" Valve Wheel Is
Made
cocks and the like. This trouble renders the handles use-
less and wooden handles have in many cases been replaced
by metal, which, when used with steam, becomes hot and
disagreeable to handle.
The "Kantsplit" handle seems to be so constructed a,s
to prevent splitting and working loose from its bottom
PRINCIPAL EQUIPMENT OF STIFEL BREWERY PLANT
Equipment Kind Size Use Operating Conditic
3 Boilers Vertical water-tube 500-hp Generate steam 150-lb. pressure,
Maker
itural draft, stokers Wickes Boiler Co.
3 Stokers Chain grate 87-sq.ft Serve boilers Motor driven Laclede-Christy Clay Products Co.
1 Motor Direct-current 5J-hp Drive stoker shaft 110 volt, 1000 r.p.m Sprague Electric Co.
1 Ash removal system Vacuum 8~in. pipe, f-in. nozzle Convey ashes from pita Steam pressure 114 lb. at nozzle, ca- Girtanner-Daviess Engineering &
to tank pacity 200 lb. per min Contracting Co.
1 Coal handling sys- Bucket elevator and
tem screw convevor. . 30 tons per hour .. Transfer coal to bunkei Geared to motor, latio 7 to 1 Stephens- Adamaon Mfg. Co.
1 Stack Radial tile 185-ft. high, 7J ft. dia. Serve boilers 1 in. draft at base Wiederholdt Construction Co.
1 Pump Dupl'-x 10x6xl0-in Boiler feed 150-lb. steam pressure Epping-Carpenter Co.
1 Pump Simplex "Hooker". 12x7xl2-in Boiler feed 150-lb. steam pressure Reliance Machine & Tool Works
2 Lubricators Force feed Serve boiler feed pumps . Hills-McCanna Co.
1 Heater Open 1000-hp Heat boiler feed water Exhaust steam Harrison Safety Boiler Works
knowing the amount of ashes removed per year or the life
of the equipment, but at a rough estimate the total cost
should not exceed 10 to 12c. per ton.
Feed water for the boilers comes from a 1000-hp. open
heater in the old plant. It flows by gravity to the pumps,
one of which is a ]0xiixl0-in duplex and the other a
12x?xl2-in. simplex taken from the old equipment. The
water lines are arranged to feed the boilers at either top
or bottom, and for the present the water is fed at both
points, with a view to reducing pulsations set up by the
single pump. There is also a duplication of feed mains
so that one pump may supply cold water for washing
one or more boilers while the other i- supplying the hot
feed water as usual.
At present means for measuring water and weighing
coal have not been provided. It is the intention, however,
to install at an early date a water meter, coal scales below
the bunker, a damper regulator and C02 apparatus. With
these refinements so necessary for the keeping of accurate
records, the plant, for its capacity, will be one of the finest
in the country. Including building, stack, the fourth
plate. The illustration shows how it is made. The
handle is of birch or maple wood, which is used as a mold
into which is cast a metal wheel, the spokes of which
bind the fibers of the wood together and prevent it from
splitting.
A- the metal "freezes" to, and engages projection.- of.
the top and bottom plate so as to make the finished han-
dle one piece, the bottom plate cannot easily work L
The handle is inexpensive and is made by the Holton-
Abbott Manufacturing Co., 61 Gorham St., West Somer-
ville, Mass.
B
Figures on the cost of generation in small municipal
plants are always interesting. The following are taken
from the annual report of the oOO-kw. municipal plant
at Topeka, Kan., and include depreciation at 5 per
cent., interest at 4 per cent, and taxes at 1.725 per cent.
Net cost per kw.-hr. at switchboard $0.0165
Net transmission cost per kw.-hr 0.007S4
Gross cost per kw.-hr. at lamps, including all
operating-, overhead and fixed charges 0.0427
Net cost per arc lamp per year 24 . 31
Net cost per 100- watt series tungsten lamp per year 14.66
666
p o w e i;
Vol. 41, No. 20
IimHerier Wiriimg' for ILng'Jhiliinig' aimd
§®3rvfLC©~°II]II
By A. L. C 5
SYNOPSIS— How to figure the sizes of branch
eders in lighting service for both
direct- and alternating-current systems. The next
installment will i ■ uits.
Two-Wire System
The two-wire system, previously described, is the
simplest arrangement of lighting circuits. In laying out
this or any other arrangement the voltage drop for the
circuits must first be calculated. For direct-current cir-
cuits the drop can be calculated from the formula,
21.4 X D X 1
e = ; -. —
circ.rmls
where
e = Total drop in the two wires :
D = Distance in feet between the feeding point and
the load: in other words, the distance one
way ;
/ = Current in amperes.
To determine the size of wire for a given loss in volts
the formula may be transposed to
21.4 XV XI
< vrc.mils =
e
The number 22 is sometimes used instead of 21.4 but
the latter is satisfactory unless the wires are to lie located
in a very warm place. An example of the use of these
formulas may be helpful. Suppose the feeder is No.
00 B. & S. (13:;, 100 circ.mils.), the length of run
150 ft., and the load 50 amp.
21.4 X 150 X 50
13:;, li)0
1.2 volts
If it is required to find the size of wire for this circuit
with a loss of 1.5 volts,
21.4 X 150 X 50 ,„„
, 'irc.mils = — — — — = 107,000
1.5
Referring to Table ? (page 045. May 11 issue) it will be
seen that the nearest size is No. 0, which is slightly
smaller than required.
While any direct-current two-wire circuit can be
calculated by means of these formulas, it is more con-
venient to use some form of chart. The one printed
in Fig. 7 is based upon the formula already given and
is a modification of a chart devised by E. W. Stovel and
X. A. Carle (see The Electric Journal, June, 1908).
It it is desired to find the drop for the feeder already
calculated, start at 50 amp. on the lower left-hand side
and follow vertically until this line crosses that for 00
wire; then pass horizontally to the right to the line
marked 150 ft. and follow down vertically and read
1.2 volts.
To determine the size of wire as in the second problem,
start with 1.5 volts at the lower right-hand side and
follow up vertically to the 150-ft. line; then horizontally
to the left to the line for 50 amp., which also crosses
the No. 0 line at this point.
Suppose it is desired to find the drop when 6 amp. is
carried by a No. 1'-' wire for a distance of 100 ft. The I
chart ']">■< not give a value for 6 amp., but the drop can
he figured for 12 amp. and then divided by 2, since it
will he half as great as for 12 amp. Using the chart,
we obtain 4 volts, so the drop for 6 amp. would be 2
\olts.
If it is desired to find the drop for 125 amp. carried <
on a 300, 000-circ.mil cable a distance of 200 It., the
position of the 125-amp. line will have to be estimated \
between the 100- and the 150-amp. lines. Carrying this
up to the :i00, 000-circ.mil line and then across to the
right and down as before will show a drop of 1.8 volts.
Returning to the original problem, compare the size
of wire required for 240 volts with that for 120. If the
load is 50 amp. at 120 volts, this is 50 X 120 = 6000 i
watts. With the same load at 240 volts, the current would I
be 6000 -=- '- 10 = 25 amp., or one-half that for the lower I
voltage. Hence, the same percentage drop can be allowed \
for the higher voltage; that is, if 1.2 volts are allowed in
the first case, 2.4 in the second will give satisfactory
operation. From the chart it will be found that the size
of wire required is No. 5. For 120 volts, therefore. No.
00 wire having 133,100 circ.mils is required, and for
240 volts to transmit the same power, only 33,100
circ.niils, or % the size. No. 5 wire is a size not
ordinarily used, so that No. 4 would probably be employed,
but the saving due to the higher voltage is apparent.
If the load eonsiM- entirely of incandescent lamps the
current can be determined either by dividing the total
vat is on the feeder by the voltage of the lamps or by
multiplying the current per lamp (see Table 1, page 602,
May 4 issue) by the number of lamps. With arc lamps
it is best to multiply the current taken by each lamp by
the number of lamps. For alternating-current circuits,
the same chart may be used if the two wires of a circuit
are run in the same conduit and the load consists of
incandescent lamps. Alternating-current arc lamps have
a power factor of about 0.70 or 0.65, and if a large load
of these were to be carried on a feeder the drop would lie
greater than for direct-current and the method employed
for calculating motor circuits, as described later, should
be used. For wires not larger than No. 4 the chart can
be used without modification for circuits carrying alter-
nating-current arc lamps. For exposed work, where the
wires are separated several inches, the drop on the circuits
would be greater than for direct current. In the case of \
branch circuits No. 10 or smaller, the increased drop
is small even with arc lamps; consequently, the direct-
current chart can be used. For the feeders, however,
the drop should be calculated by the method used for
motor circuits. If a feeder carries both arc and in-
candescent lamps, it is not correct to add the two circuits
together. This is because of the power factor.
Braxci: Circuits
The wiring of an electric-light installation is divided
into branch circuits, to which the individual lights are
connected, and the feeders which supply the branches.
667
I" o w E t;
Vol. II, No. 20
Sometimes, a feeder supplies more than one group of
branch circuits, in which rase there are feeders and
sub-feeders, or mains, feeding the individual groups. The
arrangement of circuits varies to suil conditions. Kg.
8-a shows a scheme sometimes used in mills where the
cosl must be kepi down. Here, mains are run the length
of the room and the lights tapped directly from them
through individual fuses in the rosettes, no branch cir-
44 4 4 4
J Y Y Y Y Y
Y Y Y Y Y Y
II Y V V Y v y
[ Mams
inches
Y Y Y U
J YYYYY
444444
| Y Y v v v v
Lamps
YYY Y Y
J YYYY Y
X Switch
-t-t— : Board
reerter
1 Feeder
(") 0)
Fig. 8. Arrangement of Branch (Harris
i ii its, being used. Its principal objections are lark of
control of the individual circuits and variation in voltage
at the lights, as those nearest the fuse blocks may have
a voltage 2 or 3 per cent, higher than those at the extreme
end. A modification of this arrangement is shown in
Fig. 8-b. Here the lamps are arranged in groups taking
not more than fifiO or 1320 watts, depending on the kind
of outlet, and each group is wired separately to a panel-
board. This has the advantage of individual control of
the groups of lamps and while more expensive i- used
extensively, particularly with large-sized lighting units.
Fig. 0 shows an arrangement frequently used for small
office buildings and sometimes for factories. Here there
is a panel-board on each floor, from which the branch
circuits are run. This has some of the objections found
in Fig. 8-a since the drop to the panel on the top floor
will be greater than that to the first floor. However,
it 10 furh satisfactory for buildings of four stones or
less, particularly if the load on each panel is relatively
small. In Fig. 10 is shown a modification of this arrange-
ment which results in much better voltage regulation,
since the drop to each panel can be made about the same.
A further modification would provide one feeder for each
panel, but this is justified only when the load on the
panel is very large. As a rule, not more than three panels
should be placed on one feeder.
It is assumed that the number, size and location of thi
outlets have been settled as previously described. If control
switches are to be provided, they should be located care-
fully. For offices and similar places they should be
placed about 1 ft. from the floor, near the entrance dooi
on the lock side, so as not to be hidden when the door
is open. In factories they may be located on column- or
side walls and should be grouped as much as possible,
to save wiring. When the tenants are supplied with
meters they should be placed near the panel-board if
possible, or in the various offices. .Meters are not commonly
used, owing to the cost, the Usual method being to charge
each tenant a flat rate for lighting. The panel-board
should be as near the center of the load which it is to
supply as possible, as this results in more uniform voltage
on all the lamps. For office buildings the best location
is in the halls, the panels being, as far as possible, a1
corresponding points on the various floors, so as to give
direct vertical runs for the feeders. For factories they
should be near the center of the room, if feasible, and
for very large areas the room may be divided into two or
more parts and a panel provided near the (enter of each jf
part. The number and location of panels are fixed by
the number of branch circuits and their lengths. It is
unwise to use long branch circuits because of the high
drop, and for uniformity in wiring it is generally best
to settle on one size of wire for all branch circuits I
irrespei tive of their lengths.
As a guide in locating the panel, it is convenient to
know the length of branch which can be used and not
exceed 1.5 per cent. drop. Table 8 gives these values for I
the sizes of wire ordinarily used for branches, with the
maximum load allowable and also with smaller loads.
When using this table the distance given is that to the
center of the load. For example, if there were 8 outlets I
of equal size and spaced 10 ft. apart, the center of load I
would be at the i enter of the row ; that is, a distance of 35 1
ft. from one end. If from the panel to the first lamp were
20 ft., the distance to be u<i'i\ in calculating the drop
would be 55 ft., and it would be assumed that the entire
load on the branch was to be carried to that distance. If
the units are not all the same size the center of load would
shift toward the larger ones. To calculate the center of
load in this case multiply the distance from each unit
to the panel-board by the number of watts or amperes for
that unit, add these values together and divide by the
total watts or amperes in the circuit: the result will
be the distance to the center of load. With the aid of
tin- table the location of the panel-board may be roughly
checked.
The maximum load in watts which may be carried by
one branch has already been specified, but it is also
necessary to check the number of sockets on each branch.
For a 660-watt branch not more than 16 will be allowed,
ami for a 1320-watt branch 32 is the largest number.
These rules apply to the circuits where the lamps do not
have individual fuses, but only fuses for the entire group
on one branch. These rules would allow the use of
sixteen 10-watt lamps in the first case, and thirty-two
in the second. Since the lamps are usually larger than
this, thi' number of outlets would generally be less.
Sometimes local rules modify these general rules, so it
Fig. 9. Are 'ngement for
Small Office Build-
lngs wo Factories
Fig. 10 Drop to Each
Panel about the
Same
is always best to obtain information on this point from
all parties interested. In counting the number of sockets,
plug outlets for portable lamps must be included. It is
important to have each branch circuit fully loaded, as
each additional branch which must be provided for on
the panel-board makes an additional cost of three or four
dollars in the panel; on the other hand, it is frequently
necessarj to allow for possible extensions of the branch
or an increase in the size of the lamps. The extent of
this allowance will vary. Thus, an office building, where
tin lighting requirements might be very different with
May is. 1915
POW i: i:
669
jferent tenants, Bhould be more liberally designed than
ctory lighting, where the require ots are fairly well
bed. For the latter the branches may be loaded to 90
! nut. or more of their capacity, while for the former
is best to allow only 80 to 90 per cent. load.
After the branches have been sketched in, the size of
re should In' determined. It is common to use No. 14
r branches, but reference to Table 8 will show that the
Igths must be lather short if the allowable drop of 1.5
rcent. i- not exceeded, for the usual run- in factories
d office buildings No. \~i wire will be found more
[table; and for circuits with 1320 watts, No. 10 may
e to I"' used. It is unnecessary to check all the branch
TABLE 8— BRANCH LIGHTING CIRCUITS
Maximum length of circuit for 1.5 per cent. drop.
12
-120 Volts-
10 6
-Distances in Feet*
Gage Amp. Amp. Amp. Amp. Amp. Amp. Amp. Amp.
14 29 35 58 7n 116 138 232 276
12 46 55 92 110 1M 220 360 440
10 73 S7 146 174 292 348
8 116 139 232 278 464
•Note that the distance given is in each case to the center
of load and not to the end of the run.
circuits: one or two from each panel, which appear to
have the greatest drop, being checked by means of the
chart or Table 8. If it is found that the allowable drop
is greatly exceeded, a larger wire may be used or a re-
arrangement of circuits made. If this load is decreased,
the number of circuits will be increased, ami thus affect
the cost of the panel. Therefore, it will generally lie
preferable to increase the size of wire. In any case the
branch circuit should lie fused to its maximum capacity
as follow-:
1 25 Volts or Less 125 to 250 Volts
... 10 amperes ■"• amperes
... 20 amperes 10 amperes
Referring to the example given in Table :3 (see page
604, May 1 issue ) , let us apply these rules to the machine-
Bhop floor. The natural location of the panel would
be on one of the columns on the center-line of the room.
The column nearest the center would have four bays
on one side and five on the other, giving a maximum
length of branch circuit of about IT? ft. In this case.
it would be best to run the circuit with the length
of the room, to facilitate the control, although this
TABLE 9— LOADS ON PANELS
E
C Amperes F
A B Total D Load Max-
Panel Circuits Circuits Load in at 120 imum
Floor No. in Use Provided Waits Volts Amperei
Basement .1 4 6 2.160 18 30
First floor. 2 12 16 10,800 90 160
Second door 2 12 16 10,800 90 160
Third floor. 4 8 10 3,600 30 50
Fourth floor 5 12 16 10,800 :»i 160
Fifth floor. 6 12 16 10,800 90 160
compels crossing the beams forming the bays. There
would be a maximum of 10 lamps in one row on one side
of the panel-board, the distance to the first unit on the
farthest row being about 35 ft. and that between end unit •
67.5 It.: hence, the distance to the center of the load i>
67 5 10 v ion
., 4- 35 = 68 ft. 9 in. The load is g^ = 8.3
amp.
A Xo. 1'.' wire, carrying this load, would give a drop of
1.83 volts, or 1.53 per cent., which is satisfactory. Tin
loads on the panels can now lie obtained by adding those
on each branch, each plug outlet for a portable lighi
being figured at 50 watts. The size of the panels will
be fixed by the number of circuits, plus an allowance
for extensions. For panel- up to 10 circuits, at leasi 2
-pare circuit- should he allowed and for 10 to 20 circuits
at leas! I should lie provided. These computations, for
tin- example previously discussed, are given in Table i).
Winn locating the service connection, or switchboard,
care should he taken to place it as nearly central to
the load as possible. There is generally little cl :e,
since the board must be located in the basement if the
c is underground, and if overhead it must be as
close a- possible to the point of entrance of the wires.
If the supply is from a private power plant the choice
of location is influenced by other considerations. The
place chosen in any case should be as clean and dry as
possible, am! provision should be made for preventing
access to the board by unauthorized persons.
Feedeu Systems
After determining the loads mi the panels, it is neces-
sary to plan the feeder system according to the schemes
^"■nelNo.e 5 v FLOOR
J\PanelHo.5
Nob
3*-" FLOOR
Fic 11. Rises Diagrams foe Factory Building
shown in Figs. 8, 9 or 10. An arrangement similar to
Fig. 10 is convenient where it is desirable to provide for
cutting off the power from certain sections without inter-
ferine- with the rest of the lighting. For economy it
is desirable to have the load on each feeder as great as
possible, but there i- a limit to the size of conductor which
should lie used, particularly where two or three wires
are carried in one conduit. For office buildings, partic-
ularly, it is difficult to conceal a conduit larger than
■_' j _ in. and to take care of the lone-radius bends required
for larger conduit. In general, a wire larger than 500.000
circ.mils should not be used. For the system shown in
Fie:. <i. however, the size may run larger than this.
particularly for a two-wire 120-volt system. The feeder
sy-teni should lie planned in a preliminary way, bearing
these general statements in mind, a sketch being made
showing each panel-board with its load in amperes and
the various feeders with their lengths and loads. The load
on the feeder should be taken as the total load actually
connected to the panels supplied by that feeder. For the
example given in Table '■>. the actual load in watt- is
given in column D and the load in amperes is calculated
for 120 volts usine- a two-wire system. Fig. 11 shows
the arrangement of feeders supplying the panels.
A reasonable allowance should be made for extensions
and for an increase in the lighting load. In any case, the
fee, Id- should be sufficient to allow at least 600 watts
per branch, or, it' the arrangemeni is such that the larger
c;o
puw e i;
Vol. 41, No. 20
branches are used 1200 watts per branch may be allowed :
this shoukl include the spare circuits. The feeder chosen
should then be checked to see that the drop, with the
actual load, does not exceed the allowable amount as
specified previously. If the drop is too great the l>
must be increased in size.
Column F in Table 9 gives the maximum loads for
the example chosen. Referring to Fig. 11, calculate the
size of feeder B. The length is 170 ft., the maximum
load 370 amp. and the actual load 210 amp. This re-
quires a 500,000-eirc.mi] cable if rubber wire i- used.
The drop with 210 amp. would be 1.53 volts. The
maximum allowable drop, a- previously specified, i- 1.3
per cent, for a feeder. This is 1.56 volts for a 120-voH
, ; hence, the size of cable chosen is satisfactory. In
this case, since the subfeeders supplying panels 4 and 6
are short, practically all the drop i- in the feeder and
2 per cent, could be allowed if necessary. If the drop
in the branches is less than 1.5 per cent, it is not satis-
factory to add the amount saved in the branch circuit to
25Amp.
25Amp.
25Amp
Lamps
25 Amp
Lamps
25Amp
(a)TWO-PHASE system
25Amp.
25Amp.
35.4 Amp
±
X Lamps
\i25Amp
( t>) TWO-PMASE,TnREE-wlRE SYSTEM
Fig. 12. Current and Voltage Relations in Two-
Phase System
the feeder drop, thus making it more than 2 per cent. :
instead it should be kept within this limit.
If the total feeder drop exceed- a proper value it must
be decreased by increasing the size of feeder or subfeeder.
Generally, it is best to increase the main feeder leading
to the first panel, as the drop on the subfeeders running
to the other panels is usually small. The drop in the
subfeeders should be about 0.T per cent, and in the main
feeder 1.3 per cent. When more than one panel-board is
carried on a feeder, as in Fig. 10, the subfeeders will be
smaller than the main feeders, and would therefore not
lie protected by the fuses on the latter. To protect these
subfeeders, the panel is provided with the necessary fused
branch circuits to which they may be connected, these
circuits being connected to the main feeder where it
enters the panel. With the arrangement of Fig. 'J. the
size of feeder would be decreased for the panels on the
lower floors, the feeder entering the panel-hoard at the
bottom and leaving at the top. and fuses must be provided
at the top to protect the subfeeder above. The panel
busbars must be large enough to carry the entire current
of the panel and the subfeeders connected to it. When
the sizes of wires have been checked, the sizes of conduit
can be determined by means of Table 6 (see page 641,
May 11 issue i. bearing in mind that both wires of a
circuit must be in the same conduit if alternating current
is used.
Three-Wire Ststem
Calculation of a three-wire system is much the same I
as that of a two-wire, so that only the points of difference
will be discussed. As long as the load is the same on
each side of the system there will be no current in the
neutral. If. however, the load on the positive side were
20 amp. and on the negative 25, there would lie 5 amp.
in the neutral. If all the load were removed from the
positive sidi . the current in the neutral would be the same
as in the negative wire. Since there is always a chance
of the load being different on two sides of a three-wire
system, the neutral must be sufficiently large to earn- the
difference, and is generally made the >ame size as the out-
side wires. This is not required by the "National
Electric Code," except in certain cases, but it is good
practice. If the neutral circuit is opened when the load
ich side is the same, there will be no change in the
voltage across each group of lamps; but if the negative
side, for example, has a larger load than the positive, the
lamp- on the former would receive less than 120 volts and
those on the latter more; hence, these lamps might burn
out. Such a case might occur if a fuse in the neutral
should blow.
The location of outlets would be the same as for the
two-wire system, since the branch circuits are two-wire
in any case. The location of panel-boards and -witch-
boards is determined in the same manner, and the
arrangement of the circuits may be similar to those shown
in Figs. 8. 9 or 10, using three-wire mains and feeders in-
stead of two-wire. The layout of the branch circuits
would be made in the manner previously described, and
the drop would be limited to about l.S volts, since 120
is the voltage for the branches. The branch circuits
are so connected to the panels as to give practically half
the total load on each side: in other words, to produce
a balanced system. The actual load in each outside wire
of the feeder would, therefore, be one-half the total for
all the lamps supplied from that panel.
The determination of the feeder sizes is governed by
the same rules as tor the two-wire system. The actual
loads in the outside wires would be the sum of the loads
for all the panels supplied by that feeder. The maximum
luad should also lie determined by allowing 5 or 10 amp.
for each branch connected to either side of the circuit.
When these loads have been determined for each main
feeder and subfeeder. the size of wire may be chosen by
means of Table 7 (see page 642, May 11 issue), using the
maximum loads as before. The feeders should then be
checked for voltage drop with the actual load. The
voltage b>>s allowable in the feeders is 2 per cent, of
the voltage to the neutral, for each side of the system.
Thus, if a 120-240 volt system i- used the drop for each
side of the system may be 2.4 volts. With a balanced
load, all of this occurs in the outside wires. If the load
were unbalanced, there would be some drop in the neutral,
but in any well-designed system this is so small that it
may lie neglected.
Care should lie taken when using the chart, since it
gives the drop for a length of wire twice that marked on
the various lines, which i> the length of run. If the current
in the outside wire of a two-wire feeder is used, and the
length taken is that for the feeder, then the voltage drop
May 18, 1915
l'o AY E i;
671
obtained by tin' i hart should be divided by "2 to obtain
I tin- drop in a single wire. After the sizes of the outside
awires have been determined the neutral may be taken the
same, and then the conduit sizes are determined, using
lone conduit fur all three wires if alternating-current is
employed.
Referring to the previous example, feeder B would have
a maximum load of 185 amp. and an actual" load of 105.
A drop not exceeding 2.1 volts can be allowed in each
of the outside wires, and to carry 185 amp.. No. 0000
' cable must be used. The drop on a two-wire circuit
having a length v\' run of 1 TO ft. is 1.8 volts; hence, that
1 for 170 ft. of wire is 0.9 volt, and this is the drop on
each of the outside wires of feeder B. The actual voltage
loss on the lamps, however, is only 0.9 volt, since they
are affected only by the drop in the wires to which they
are connected.
.Sometimes a three-wire system is arranged so that it
in n be changed to a two-wire by connecting the outside
wires together at the switchboard. This transforms it
into a 120-volt two-wire system. If this is to be done,
each side should be calculated as a two-wire system with
one-half load, the outside wires being made of the size
thus determined and the neutral double this size. Some-
times, this type of system is calculated as a three-wire,
and then the neutral is made twice the size of the outside
wires, but this arrangement results in a higher drop at
the lamps than wdien it is run as a three-wire system.
Three-Piiasi-: System
Three-phase systems are sometimes used for lighting,
but should lie avoided for such service if possible. The
three-phase system with three wires takes considerably
more copper than the three-wire system, while the four-
wire arrangement saves in copper at the expense of added
complication in the panel-boards. The branch circuits
would be two-wire, as in the previous arrangements.
After the sizes of feeders have been determined from
Table 7 by using the maximum load, the drop should
be checked by means of the chart. Allowing 2 per
cent, drop, this amounts to 2.4 volts across the lamps
for a 120-volt system. The allowable drop for each wire
is 0.58 times 2.1 Milts, or 1.39, and the size should be
determined, using the actual load previously found. In
using the chart it should be remembered that it gives a
drop for a two-wire circuit, SO the voltage drop obtained
should be divided by 2. The chart can be used if the three
wires of a feeder are all in the same conduit : if not, other
methods to be described later may have to be used. If
(he three-phase four-wire system is used, the branch cir-
cuits would he divided into three equal parts as before, ami
connected between the three main wires and a common
wire called the neutral. The current in each of the main
wires would be the total lor all the lamps connected to
that wire, and that in the neutral would be zero as long
as the current in all the main wires was the same. The
actual ami maximum currents would be determined as
before, using the branches connected to one of the out-
side wires. If the allowable drop in the feeders is 2 per
cent., this applies to each main wire, so the drop in each
of these wires for 120 volts across the lamps would be
4.8 volts. The wire size can be obtained in the same
manner as before and the neutral made the same size
as the other wires.
The two-phase system, for use in lighting, is open to
the same objections as the three-phase, if all the feeders
and >ubfeeders are made two-phase. Either of the plans
shown in Fig. 12 may Lie used, h the arrangement in
a is used each phase can be treated independently and
figured as a simple two-wire system, hut with arrangement
b, the current in the common wire is obtained by adding
together the currents in the two outside wires and multi-
plying by 0.71. When the load is practically the same on
each side, the voltage drop can lie computed readily.
First calculate the drop in either outside wire with the
current previously determined, then the drop in the
common wire which would be caused by this same current.
Adil these together and let the result he represented by A.
Then calculate the drop in the common wire due to the
current from the other outside wire, and let this be
B. The total drop is V A 1 + BK
In general, the three-phase or the two-phase systems
are not well adapted for interior wiring. If either of
these systems must be depended upon as a source of
supply, it is better to arrange the circuits as a single
phase, two-wire or three-wire system.
sur<
By A. D. Williams
Manufacturing operations at the plant of the Firestone
Rubber Co., Akron. Ohio, require pressure water at 700
and 1200 lb. per sq.in., and the method adopted to obtain
this service is shown in the illustration. Two dead-weight
loaded accumulators are used, and the pumping plant is
Arrangement of Accumulator Piping
designed to deliver to the higher-pressure accumulator and
to hold it at the highest point of the stroke, delivering
water to supply the demand for both pressures. As soon
as the high-pressure accumulator rises its full height it
opens a valve and a portion of the water flows to the low-
pressure accumulator and this, when it reaches the top of
its stroke, opens a relief valve, permitting the surplus
water to return to the sump or sewer.
To prevent excessive waste of pressure water the steam
supply to the pressure pumps is shut off automatically
when hie low-pressure accumulator rises to a sufficient
height to open the relief valve. The pumps are automatical-
ly started when either the low- or high-pressure accumula-
672
rii w b i:
Vol. 41, No. 30
rops a certain amount. Tin- starting device is so ar-
-i that it will act to start the pump if the high-
pressure accumulator drops while the low-pressure ac-
cumulator still remains at its highest position. This pro-
vision is necessary, as the demand for pressure water is
variable upon each of the two pressure systems and a heavy
demand might be made on the 1200-lb; line at a time -
n.l on the 700-lb. line. In practice the arrangement
works out nicely, maintaining lull pressure upon both
lines ami taking care of all service demands.
Pressure water is supplied to the system by three pumps.
One is a I-a'.'Hx I1 L>\'-' l-in. outside-packed plunger pump
with a Corliss cross-compound steam end and flywheel.
At present this machine is operating noncondensing, but
later is to be connected to a condenser. It will deliver
300 gal. per min. at 50 r.p.ni. There are two duplex-
compound outside-packed plunger pump.-. 12&18x5%xlu
in. These comprised the first hydraulic-service installa-
tion, the flywheel pump having been added within the
year.
DnmemisiioiniS
^iniElinK
By H. L. Watso.n
SYNOPSIS — A chart for graphically determining
tlie speed, bore and stroke for a given type and
of internal-combustion engine according to
averagi American practice.
During the summer of 1912 there appeared in Power
a series of articles by Messrs. Ulbricht and Torrance
u on •"American Practice in Hating Internal-Combustion
in the form of curves from which empirical equation-
were obtained. By means of these equations it is possible
to determine the cylinder bore, stroke and revolutions per
minute necessary for an engine of any desired type, fuel,
and power; four-stroke-cycle stationary engines only be-
ing considered. These equations are given in Tables 1
and 2.
It occurred to the writer that these equations might be
plotted upon one sheet, thus reducing the work necessary
Re
Producer gas
d=ln = 1S.500 (b.hp. + 21 Average — all values,
d'ln = 17.900 (b.hp. + 1) Single-acting— horizon
d=ln = 20,600 (b.hp. + 4) tal and vertical
Double-acting — hori-
zontal
atural gas
d'ln = 15,200 (b.hp. 4- 5) Average — all arrange-
ments
Illuminate..
d2ln = 15,700 (b.hp. 4- 2) Single-acting — horizo
tal and vertical
Blast-Fun] m
d=ln = 21,000 (b.hp. + 5)
Oils and distillates
d2ln = 21,875 (b.hp. + 0 751 Single-acting — horizon-
tal and vertical
Gasoline
d*ln = 16,400 (b.hp.) + 0 .".l Single-acting— horiz
tal and vertical
Type of Engine
Relation of
n to b.hp.
Vertical
Single-acting
Horizontal single-cylin-
der
Single-acting
b.hp. 4- 14
+ 176 d = 0.91 (1) —0.45
b.hp. + 21
Horiaontal
Double-acting
b hp. + 29
d = 0 667 (1) 4- 0.4
d =0 772(1) +0
Natural Gas
d =0.533(1) + 4
Producer Ga-
il = 0.667 (11 + 2
.1 -Mi 45d= =0.91 (d-l)
d' - U.4d- =0.667 (d-l)l
d3 -0 55d2=0.772<d2l)
Natural Gas
d» -4d2 =0 533<d2l)
Producer Gas
d'-2d2=0 667<d2l>
Procedure
1. Assume tvpe of engine, b.hp. and fuel
2. Obtain <d2ln) from Table 1.
3. Obtain (n) from Table 2, col. 1.
4. Obtain (d'l).
5. Obtain (d) from Table 2, col. 3.
6. Obtain (1) from Table 2, eol. 2.
In all cases b.hp. = brake horsepower per cylinder end.
d = cylinder diameter in inches.
1 = length of stroke in inches,
n = revolutions per minute.
Engines."'* These represented the results of an extensive
thesis made at Cornell Universitv under the direction of
Professors Diederich and Hirshfeld, the data being given
i-a« copyrighted by T. C. Ulbricht and C. E.
for the solution of a problem. Upon such a chart, here-
with shown, all curves denoted by letters refer to the type
of engine, and those denoted by Roman numerals refer
to the fuel used. To further distinguish them the curve-
are represented by different kinds of lines.
May IS, 1915
r 0 W E R
673
ainujn jad 9uoi4.niOAay
S3U,0U| Ul J3pui|^3 JO JaiQLUDIQ
4-
<*
Ki
O
CO
IT)
o
O
c
CO
-4-
vffl
CO
o
CVJ
•*
iO
CO
o
CO
oo
CO
CO
ID
CO
CO
o
ro
to
ro
•c
\
4
I I I II I I I I I I I
I I MINI
\
£ g
-C 5 ClS sis ^-i;^;t<
J-g-s; ^ $> ts ^^.c c
"1 § S » fc.%<»|s^
~
\
1
^M
'
> o
0 -o
■
L
*:
+-*
., •
1
.
5 -oV :
n^
-
/
f
/
4^
■
'
E C
o
■m
CO
-
M
Olx'
-,'
i l
/
J
<b<-
1,
/
\-t
s>
,
i
v
—
§
t-1
>A
<£^k
T
'
■
-'.
/
1^-
\^*\
^
.
c
'.
'
/
;
CO
/
—
■\\
W^
•
/
t
r5
b
* •
/
/
I
o
,:
>'
'
/
fr
_ (
i 1
-q^w
}o-
l — 3 Lr>'
•'
V ,
1
r
6 ^ ft i ^ fi
¥ x/
/\M
_(_
' A' ;
_
/
w [U
■*
ro
<
(
/ /
k
V
-
: >
m 1
. . -.
~2U
'
UJ 1— UJ —
h- 3 Z
y ? 5 -
Quiz
liJ 5 H
D S «"
Z ° =>
l-i"
r^ -1 o
<-> O o
2 > II _
^ K |
m Q ^
o 2 tr
H ^ 5
cr o 7
< a: < -
X 1- u.
O if) o \
rr"t
/ /
i
\Y?
\\\ c
M
^fcsitq^eifc.
W
7-
/ —
HJ
1 V\\\\ o
wm\ in1
'■
!
<
1
---
P
f
^z
"-
-""'
—
~~
CO
r-
<B
Lfi
"4
ro
CO
—
o
c
j
•j
co
o
CO
^h |«6
CO
0-1
CO
CO
CO
iXJCO
coco
rO
\
1
1
1 1
1
—
:
1 ' ! 1
1 1 ! 1! 1 1
iP
J
!l ^ |i»
*
*
•
/////MINI
^
v
f*
N
//////
\vT
gi» a - « ^
=Ccqoooq\_>QQC1
L
9^
A/
/////
■3
r\\
—
*
/
//////
<_
W
i
?-/
V
JJllW
-w
O | CO
ro
9)
71/ /////I)
V
jy
/
,, /
Q-
• \V
y
.
'
a
..'\\
rf
^_
// //////// / /
TO
*
S)
<0/
oc
/
/ ////m.tu
~
_
-
-
-
^
y
^
vJ>
i
•\
-WJ&
ii [I i ii / 1 / 1
"\t<mI
/
.,\ao
1/
i/
ATtw
hjTi
T
K
*
S,
•
o
si
4-
jo
(L-
\
\
0 t
Oh.
O
z
c
)
1
te
^
I
N
\
A
\
<
I"
#
4
5*1
o
^
■i
^
c
y\
V
x0°
/4?
c
>
\A
V
c
<
1
c
c
c
c
674
P 0 W E R
Vol. 41, No. 20
The expression giving the power of an engine per cyl-
inder end is
Bh = PLAN
33, QUO X mechanical efficiency
where
P= Menu effective pressure;
L = Stroke in feel :
,4 = Cross-sectional area of cylinder in square
inches ;
N = Number of explosions in that cylinder end per
minute.
It may thus be said that the power is a function of
drln,
where
,/ = Diameter of cylinder in inches;
I = Stroke in inches :
n = Revolutions per minute.
The equations of the relations between b.hp. per cylin-
der end and <Pln for different fuels have been replotted
in the upper right-hand section of the chart. The curves
between brake horsepower and revolutions per minute for
engines of different types have also been plotted in this
section, while those showing the relations between bore
and stroke for engines of different types have been re-
plotted in section D.
It was necessary to plot curves giving the relations be-
tween (Pin and cL This was done by first drawing in sec-
tion B a series of curves between dHn and d2l for various
r.p.m.. and then plotting in section C curves showing the
relations between <Pl and d for the different types of en-
gines. The equations of these latter curves were deter-
mined as follows :
From Table 2, col. 2 (for a vertical, single-acting en-
gine)
d+ 0,45
0.91
whence
d = 0.91? — 0.45, or I =
dH =
rf3 + 0.45 d*
0.91
Proceeding in the same manner with the remaining types
of engines, the set of equations in column 3 was obtained.
The use of this chart is best illustrated by an example.
Let it be desired to determine the revolutions per minute.
stroke and bore for a single-acting, horizontal, single-cyl-
inder engine using producer gas and developing 85 b.hp.
per cylinder end.
First note the legends in the chart for the curves cor-
responding to the type of engine and fuel assumed. Upon
the 85-b.hp. ordinate in section A note the intersection
with the "type'' curve, /.',. giving (to the right) the
r.p.m. as 200. From the intersection of this same ordinate
with the "fuel" curve, II ab. pass horizontally to the left
to the intersection with the line in section B representing
200 r.p.m., thence downward to the curve B in section C :
from this point pass horizontally to the right, finding the
bore of the cylinder to be lyi^ in. By proceeding further
to the right tc the intersection with curve B in section D,
we will find the stroke of the engine to be approximately
25% in.
It must be remembered that these curves have been
drawn through many values plotted and, as such, represent
the average size and speed for an engine of the type and
power desired, built according to American practice, as
set forth in the original article.
FrsMraMMia C^Snimdexf' Oil
Engineers have learned by experience that if cylinder
oil is fed through a pipe connection that just passes
through the shell of a steam pipe, the oil is not well
distributed in the engine cylinder to which the pipe
is connected. A number of atomizing devices have been
Fie 1. The Atomizing Tube
used, such as perforated
pipes that extend part way
across the inside of the
steam pipe.
What is known as the
Franklin oil "carburetor'' is
made by the Franklin Oil
& 'ci> Co.. Bedford. Ohio.
It is designed to atomize the
oil so that it will mix with
the steam before it enters
the cylinder.
The device is made with
a nut having a threaded
shank with a hollow tube
extension that is plugged at
the inner end. The top of
the tube is slotted and two
rows of small holes are
drilled in the tubes about
one-quarter way around
from each side of the top
slot. Holes are also drilled in the plugged end.
heated, atomized oil is discharged through the holes.
1 illustrates the idea.
The ••carburetor" is screwed into the steam pipe with
the slotted side up when at its permanent position. The
lubricator or forced feed pump discharge pipe is screwed
to the thread inside the nut which is outside of the
steam pipe, Fig. 2. The appliance is made in three
sizes— %-, l/2- and %-m. standard pipe threads, and of
different lengths to meet the requirements of the steam-
line diameter.
Pig. 2. "Carburetor"
as Used with a
Lubricator
The
Pie.
JoiPSiEadle^
While waste is one of the minor items of power-plant
supply, a saving of any considerable percentage of the
aggregate amount spent for this commodity in one year
would be a very tidy sum. The Royal Manufacturing
Co., of Rahway, X. J., extensive dealer in cotton and
woolen waste, is making an attempt to standardize the
trade. It lias divided its wares into twelve branded
grades, of which samples are furnished in a folder. The
waste is bought by its branded name, and the packages
are guaranteed to contain not over a certain amount of
tare and to be of accurate weight, so that the payment
for a lot of hoops and bagging at waste prices, or the
padding of an order 30 to 50 per cent., is avoided.
May L8, L915
PO w e i;
Br C. P. HlESHFELD*
675
SYNOPSIS — Draft llir<>ii<jh u boiler simply ex-
plained by comparison with a pipe carrying water
iiiiilcr pressure. The stack is considered as u pump
and its action explained [nun this viewpoint.
Despite tin' fart that much has been written on the
subject of draft and its significance in boiler practice,
there seem to be many engineers to whom it is more or
less mysterious. One of the simplest methods of attack-
ing this problem and one which has the advantage of giv-
ing correct viewpoints throughout is to compare the boiler
passes, flues and other parts with a pipe or conduit car-
rying water under pressure.
Measuring Head hy Standpipe or Gage
Assume for this purpose the arrangement shown in
Fig. 1. A large vessel is fitted with an overflow, and
water is supplied constantly through the nozzle shown. If
the overflow is large enough, the height of water will re-
main constant at the level shown. The pipe leading from
tered the pipe, flow is continuously resisted by the friction
ol' the walls ami nunc of the remaining head is used in
overcoming this frictional resistance.
Thus, just before entering the horizontal pipe the
head remaining is h-h', but by the time the water reaches
the lii'st standpipe the head has been reduced to //,. The
amounf /<,' has been used to overcome resistance to en-
trance to the pipe and resistance to flow through the pipe
up to the point of location of the standpipe. The head
h.,' is used in overcoming the resistance offered by fric-
tion in the stretch of pipe between the first and second
standpi pes.
The heads of water used in the discussion above are
merely measures of pressures, and pressure gages might
have been used instead of standpipes for reading the loss
of head or pressure along the length of the pipe. This
arrangement is shown in Fig. 3. If gages 1 and 2 are
located at the points previously occupied by the corre-
sponding standpipes, the difference between the gage
readings will be equal to h.,', if converted into feet of
water.
•h-h
Illustrating Reduction of Pressure Di i co Resistance to Flow
the bottom of the vessel will, for the time being, be as
Binned closed at the right-hand end. Under such condi-
tions, the pipe will stand full of water under a head h.
If holes are drilled in the horizontal pipe and fitted with
standpipes, as shown, the water will rise in each stand-
pipe to the same height as that in the main vessel.
If the end of the horizontal pipe is opened so that a
steady flow of water can occur, the water in the vertical
pipes stands at successively lower heights as the open end
of the pipe is approached. This is shown in Fig. 2. The
explanation, as commonly expressed, is that part of the
head is used up in overcoming frictional and similar re-
sistances to flow. It is obvious that dynamic conditions
(flow occurring) and static conditions (no flow) are dif-
ferent.
Analyzing the case shown in Fig. 2 more closely, the
most obvious difference between it and that shown in
Fig. 1 is the fact that the water in the former is moving.
As water possessses mass, energy is required to give it
motion, and this energy can be measured in terms of a
head of water. Thus, in the case of Fig. 2 the required
head might he that shown by the height h'. This much of
the total head /( would be used in the large vessel for im-
parting velocity to the water. The water flowing out of
the large vessel encounters resistance where it enters the
pipe, and a part of the remaining head h-h' is lost or used
in overcoming this resistance. After the water has en-
It should be particularly noted that the pressure on the
surface of the water in the larger vessel is atmospheric
and also that the pressure of the water just as it issues
from the end of the horizontal pipe is also atmospheric.
That means that the total head h must have been used
within the system. Part was used in overcoming resist-
ances, the rest in giving the water velocity; the latter
part of the head is represented by the velocity with which
the jet of water enters the atmosphere.
If difficulty is experienced in recognizing the fact that
the pressure of (or on) the issuing jet is atmospheric, it
is only necessary to consider what would happen if it
were not. If the pressure of water in the jet were greater
than that of the atmosphere, the jet would burst or spread
laterally as soon as it issued from the confining walls of
the pipe. If the pressure of the water were less than at-
mospheric, the jet would be compressed by the atmosphere
to a smaller diameter than that of the inner surface of
the pipe.
Showing Variation in Head Graphically
Referring to Fig. I, with static conditions (discharge
end of pipe closed), the pressure throughout the length
of the pipe is the same and equal to that caused by the
head A plus that caused by the atmosphere on the liquid.
This is shown by the line AB at a height above atmo-
spheric pressure equal to a, which represents a pressure
equal to that caused by h feet of water. With dynamic
conditions, the case is different. The pressure just inside
puwe r,
Vol. 41, No. 20
the entrance of the pipe is shown by the height of A',
the distance between A' and .1 representing the head used
in giving the water its velocity and in overcoming re-
sistance to entrance at the inlet. If the pipe is uniform
for it- icngth so thai the friction loss is the same
at all points, the loss of head or pressure will be the same
per unit of length at any point along the length and the
pressure drop will be as shown by the line A'B'. When
the end of the pipe is readied, the pressure of the water
is equal to that of the atmosphere. This is shown by the
location of the point B' on the atmospheric line in Fig. -4.
Prur vs. Pan
For the purpose of getting a case which more nearly
parallels the conditions existing in the case of a boiler,
the arrangement of apparatus so far considered will be
slightly changed. Imagine a vessel connected to a pipe
and pump, as shown in Fisr. 5. When the pump is not in
operation, the water will stand at some height h in the
Atmospheric,
tion loss. The drop EF represents the loss caused by the
upper elbow and by resistances to entry at the pump, so
that the pressure which would be shown by a gage con-
nected to a point inside the eye of the pump impeller
would he that indicated at F, and obviously lower than
atmospheric. In the pump the pressure is raised fro:
that shown at F to that shown at G and then there is
gradual and regular lo pressure again because
the frictional resistance offered by the discharge pipe.
This case is practically identical with that of a boilei
under induced draft, as shown in a simplified way in.
Fig. '. . The pressure in the ashpit is that of the atmos-
phere. The air is started in motion and passes through
the grate and fuel bed against a certain frictional resign
ani i . so that there is some such drop as that indicated by.
AB in getting from beneath the grate to the interior of
the combustion chamber. Flow from that point to the
damper occurs in comparatively large passages offering
small frictional resistance, so that the drop from the coni-
S--
Atmospheric __ ^
Pressure '<
Atmospheric
Atmospheric
? loss due to velocity
i K+entrance
*- A*x
Pressure
due to C
head h ^\P
Distance along Pipe •
FIG.4
Distance along Pipe
FIG 6.
_Atmospheric_ Pressure/
E "F
This axis is several inches of water
pressure below atmospheric
FIG.7.
Showing How the Action of a Centrifugal Pdmp Is Like That oi a Fax
tank and the pipe, and the pressure on the two surfaces
of the water will he atmospheric. When the pump is
operating, the pipe is filled with water which flows up to
the top and into the pump. It is obvious that the water
is forced to flow up the pipe by the atmospheric pressure
exerted on the surface in the open tank, and if this is true,
the pressure within the pipe at the same height must be
less than atmospheric. Shown graphically, the case would
appear as in Fig. 6. In this figure, the pipe length has
been straightened and shown on the horizontal axis as
before.
At the point A in Fisr. 6, which represents conditions
just inside the entrance to the suction pipe, the pressure
is ecpial to that due to atmospheric plus that due to the
head h less that lost by conversion to velocity and by
resistance to entrance to the pipe. There is then a grad-
ual drop due to friction along the straight part of the
pipe to the point B, which represents conditions at the
entrance to lower elbow. The loss through the elbow is
greater than through the same length of straight pipe,
and there is therefore a more rapid drop of pressure from
B to C in passing through the elbow. The line represent-
ing loss of pressure or head then runs from C to E, the
pressure decreasing both because of vertical rise and fric-
bustion chamber to the damper is not great. In the region
immediately preceding the damper, the gases pass through
two right-angles and the drop is therefore more rapid for
& given distance traveled than it is in the straight run
preceding. This is shown by the increased angularity
of the line CD. As shown, the damper is only partly open
and this would cause a throttling loss BE. From this
point the losses go on as before until the air finally enters
the fan wheel with a pressure as shown by F. In pass-
ing through the fan, the pressure is raised to a value
above atmospheric as shown by G and the excess above
atmospheric is then lost in passing through the stack,
so that the gases are discharged from the open end of the
stack at atmospheric pressure.
A more complicated <a>e is shown in Fig. 8, for which
a horizontal return-tubular boiler with induced draft
has been assumed. Capital letters on the graph refer
to positions indicated by small letters in the diagram
above. TJp to the point D, the case is similar to that just
discussed. Beyond that point there is a rapid drop due
to loss in entering the tubes, a gradual drop due to fric-
tion along the length of the tubes and a rapid drop due
to losses at the exit from the tubes. This results in giv-
ing a pressure such as that shown by E just outside the
May 18, 1915
POW E It
677
tubes ni the uptake. From there on the conditions are
similar to those previously described.
A more complicated case is illustrated in Pig. !». A
fan draws air I'rom the atmosphere and pumps it into the
wind box, raising the pressure I'rom atmospheric to some
such value as that shown by A'. The drop through the
fuel hed brings the pressure back to atmospheric in the
furnace and then the various losses proceed as in pre-
vious eases except that the resistance offered by the econ-
omizer adds one more complication.
Cases in which induced-draft fans are employed are
generally readily understood because it is simple to see
that the fan acts as a pump. By lowering the pressure
at its own suction it enables the atmosphere to force it-
self through the boiler ami Hues toward and into the suc-
tion orifice. The fan then raises the pressure of the gases
by the amount required to expel them against atmospheric
pressure. When a natural-draft stack is substituted for
the fan, however, many experience difficulty in appreciat
ing the fact that conditions are not really altered.
mospheric pressure. The weight in pounds supported on
a surface one square inch in extent is the pressure in
pounds per square inch. The pressure of the atmosphere
at a height of several hundred feet above the surface of
the earth is therefore less than the pressure of the atmos-
phere at the earth's surface.
The second fact above stated is easily appreciated by
taking the following point of view. Imagine a given
weight of gas to occupy a certain volume, say one cubic
foot at a certain temperature and pressure. If this gas
is heated and allowed to expand so as to maintain a con-
stant pressure, the given weight acquires a larger volume,
>a\ one and a fraction cubic feet. Obviously, there is not
as great a weigh! in one cubic foot of space at the higher
temperature as there was at the lower temperature: that
is, the density, or weight per cubic foot, has decreased
during heating.
These principles may now lie applied to explain the
operation of a stack. Imagine a tube to stand vertical on
the surface of the earth, as shown in Fig. 10. The pres-
pressure below atmospheric
fig. 8.
C c _ .Atmospheric Pressure
J
rl I
This axis is several inches of water
pressure below atmospheric
FIG.9.
Dkaft (Pbesstjke) Vabiations in Induced- ami Fokced-Deaft Boileb Fdenaces
The stack performs the same functions as a pump in
that it lowers the pressure at its suction orifice or base so
that air under atmospheric or higher pressure in the ash-
pit can force itself through the boiler and flues into the
suction orifice. The stack then practically raises the pres-
sure of the gases to such an extent that they can lie ex-
pelled against the pressure of the atmosphere at its top.
Action of Stack
Two simple facts must be realized to understand the
action of a stack : First, the pressure of the atmosphere in-
creases as one passes from a high to a low elevation, and,
second, the density or weight per cubic foot of any gas
decreases if its temperature is raised while it expands to
such an extent that its pressure remains constant.
The first of these facts can be forcibly impressed by
regarding the atmosphere as made up of a series of lay-
ers like a pile of boards, books or blankets. Obviously,
if one could weigh all the layers above a point several
hundred feet above the earth's surface, they would weigh
less than would all the layers above a point at the earth's
surface. The weight thus obtained is what is meant by at-
sui'e at the height of the top is that caused by the atmos-
phere above that point; it may be represented by p pounds
per square inch. The pressure at the earth's surface, in-
side or outside of the stack, will be greater and may he
represented by P. It will be equal to the sum of the
pressure p and the pressure p' due to the weight of air
between a point at the height of the stack and a point at
the surface of the earth.
If a horizontal chamber be built on the side of the tube
near the bottom and he separated from the tube by a dia-
phragm, as shown in Fig. 11(a), the pressure on opposite
sides of the diaphragm will be the same and equal to that
of the atmosphere at the height d above the surface of
tin' earth. If now, the air in the tube be heated it will
expand, and some of it will leave, so that a smaller weight
will remain within the tube. The downward pressure p
at the top of the tube will be due to the atmosphere above
that point and will obviously be the same at any point in
a horizontal plane at that height. The pressure at the
center of the diaphragm on the outside will be P as be-
fore, as shown in Fig. 11 (b). But the pressure on the
tube side of the diaphragm will be P' less than P, because
678
p < > \Y e i ;
Vol. 41, No.
the column oi' hot nir inside the tube weighs less than a
column of an equal height of cold air outside of the tube.
If. now, the diaphragm be imagined to lie a friction-
less and weightless piston, it is obvious that it will move
t,, the righl because of the greater pressure on its left-
band '"' IT the lower end of the tube be imagined to be
stack and serves to maintain the necessary high temper-
ature within the stack. This process is unfortunate in
one respect. When the fuel burns, its combustible con-
stituents unite with the oxygen of the air and the weigh!
of Lias leaving the fuel bed and traveling up the .-tack
i- greater than the weight of air entering bv the amount
J: j;
X
ip j
p ip
Earth's Surface
FIG. 10.
(a)
(b)
<■ P
—
>i
&-_-
rp
-
5
|*is /
IS
5
i
1
r
£
Hi
Illustrating Why \ Stack Creates a Draft
constructed with an easy bend, the piston would be pushed
clear to the top of the tube, because at any lower point
the pressure on its lower side would be greater than the
pressure on its upper side, as shown in Pig. 12. In this
figure 1\' must be less than /',. because the column of hot
air of height a inside the tube weighs less than the col-
umn of cold air outside the tube.
A stack or chimney filled with hot air and surrounded
with cold air can thus pump the hot air out of itself
against the pressure of the atmosphere above. It should
be noted in this connection that when the stack is filled
with hot gas the pressure within at the base is less than
that outside, as shown in connection with Figs. 11(a)
and 11(b) ; that is, the stack "creates a draft." It should
also lie noted that the pressures outside and inside of the
stack are the same at the top. so that the "draft" or
"under-pressure" within the stack tapers from a maxi-
mum value at the bottom to zero at the top. This is
shown diagrammatieally in Fig. 13.
It is easy to see that the line representing the pressure
within the stack must always lie below (to the right of)
the line representing the pressure outside the stack at the
same level, from the argument given in connection with
Fig. 12. It is also easy to see that it must lie above (to
the left of) the line representing atmospheric pressure at
the top of the stack, because at any point below the top
the pressure inside the stack is equal to the atmospheric
pressure above plus that due to the weight of hot air down
to the same point.
To convert the model so far considered into an opera-
tive stack, it is only necessary to supply a means of con-
tinuously heating air as it enters the bottom of the stack.
so that the shaft will always be tilled with gas at a higher
temperature than that outside. This could be done by
the use of gas flames playing on the base or by the use of
an electrical heater placed within the air at the base.
The external cold air would enter at the bottom contin-
uously in an effort to displace the warmer air in the
shaft, but as it would be heated as fast as it entered, the
process would become nothing more than a gradual sink-
ing of the external atmosphere into the stack and a pro-
cession of that same atmosphere up the stack after being
heated.
In practice, the air in passing through the fuel causes
the latter to burn and liberate heat. Part of this heat is
carried in the products of combustion to the base of the
of fuel burned. This means simply that the gases en-
tering the stack would lie heavier than the air at the same
temperature and they must therefore be heated to a higher
temperature than would pure air to give the same "draft"
at the base of the stack.
Stack as a Pump
The stack may now he investigated in connection with
a real boiler, considering it a pump, as was done with a
blower previously. For this purpose a stoker-fired water-
FlG. 1 I.
Showing Drop in Pressure in Different
Parts of Boiler
tulie boiler supplied with a forced-draft fan has been as-
sumed, as shown in Fig. 11. Capital letters on the graph
of pressure variation indicate the same points represented
by the corresponding small letters in the diagram. The
directions taken by the various parts of the graph should
be easily understood from what has preceded.
It i- obvious that the drop of pressure from D to M
is caused by the various resistances offered to the flow of
the gas by the different parts of the boiler and setting.
If the same low pressure indicated at M could be main-
tained while no gas was allowed to flow, there would be no
loss of pressure between d and m. The pressure at d
would therefore have to be the same as the pressure at m
May 18, 1915
l' o w i; i;
67a
(neglecting slight differences of elevation) ami the graph
ressures between d and m would be a horizontal line
as indicated by D'M. This is merely another case of the
difference between static and dynamic conditions pre-
viously discussed; with static conditions there is no loss
of head, with dynamic conditions there is such a loss.
Bui the stack itself is a pipe which carries gases when
in operation, and there must be a similar loss of head in
it under such conditions. Wer te to calculate the pres-
sure at the base of the stack shown in Fig. 1 1 for a given
of conditions by using the method indicated in con-
nection with Fig. 11, a value such as indicated by the
point .1/'. lower than .1/. would be obtained. The differ-
ence between atmospheric pressure and that indicated by
M'- that is. the pressure difference Z' — is called the
theoretical draft and is the pressure difference which
would he available under static conditions, ruder con-
ditions of flow, however, part of this pressure difference
or driving force is used in the stack, so that only the
smaller pressure difference '/. remains available for over-
coming the resistances in the boiler and flues.
Gas Velocity, and Resistance
The I'rictional and similar losses in stick things as
pipes, flues and stacks increase approximately with the
second power of the velocity of flow through them. Since
greater quantities of gas flow through a stack when the
boiler is operated at high ratings than when operated at
low ratings, the loss in the stack must increase rapidly
as the load increases. If no modifying conditions en-
tered the problem, it would be necessary to have such a
high stack to act the necessary available or useful draft
at high boiler ratings that the damper would have to be
nearly closed at moderate ratings. Fortunately, this is
not necessary to any such extent as might at first seem
probable.
The temperature of the products of combustion rises
rapidly with increasing load, so thai the density of the
column of gases in the stack rapidly decreases. There is,
therefore, a tendency toward increased draft as the load
increases. This is partly balanced by the fact that in-
creasing temperature and decreasing density mean in-
creasing volume and therefore increasing velocity and
loss, but the improvement is sufficient, within ordinary
ranges, to more than balance the increased loss.
Again, with a properly operated furnace the excess air
used to insure good combustion can often be decreased
as the load increases up to a high rating, and this results
in the evolution of smaller weight of gas per pound of
fuel as the load increases. This would naturally tend to
cause a decrease of stack velocity and consequently an
improvement in draft.
It is true that in most installations it is necessary to
operate with partly closed dampers at light loads and to
open the dampers as the load increases. This is not a
necessary property of such apparatus, as it is possible to
so design the various parts that the available draft is
practically self-regulating, and this has been done in sev-
eral eases.
■Wire-Drawn Saturated Steam becomes more or less super-
heated. Therefore, the apparent loss indicated by the loss
of pressure is partly compensated for and the extra pipe
friction is the greatest loss. This loss, in turn, is offset
to some extent by the fact that the coefficient of friction of
superheated is less than that of saturated steam.
Safety lint ]R>e£rig»es*adtiE3\g Ffianratts
The special hazards of refrigerating plants have re-
cently received well-deserved discussion in the columns
of the technical press, and among those doing good work
in this direction is a recent Dumber of the Travelers
Standard. As every new industry develops, unforeseen
causes of accideni become apparent, and while the engi-
neer in charge of refrigerating machinery is exposed in
such plant- tn tb "dinary dangers of power-station op-
eration, lie is also subjected to hazard- which need to be
-i" i( tally emphasized on account of their inherent relation
to this specialized branch of mechanical service. The
growth of the refrigerating industry, employing high-
pressure gases with the attendant risk of explosions and
ether accidents, is attracting the attenti if municipal
authorities to such an extent that regulations for install-
ing and operating these plants have been drawn up and put
into effect in many localities. Experience will, in all
probability, show that most of these will have to be re-
vised, and they are likely to have a history paralleling
steam-boiler regulations.
As in almost every other industry, the majority of acci-
dents are avoidable. Leaks in gaskets, through cracks in
pipes or other defective parts of equipment under pressure,
are fertile causes of trouble. Loss of ammonia is often
the result of only small leaks, but where large quantities
of ammonia escape explosion may result from the mixture
of ammonia, hydrogen, oil vapor and other volatile im-
purities, particularly where open flames are present. In-
candescent instead of arc lamps and self-closing doors be-
tween the boiler house and rooms where leaks are liable to
occur are important safeguards. Provision by which the
ammonia supply may be shut off quickly from any one of
three or four widely separated points is also a valuable
means of protection. In case of a heavy leak the avail-
ability of oxygen helmets at convenient places will facili-
tate temporary repairs and perhaps enable a complete
shutdown to be prevented.
Too much care cannot be taken to maintain all valves
in operating condition. Many valves in a refrigerating
plant are seldom used, and unless tested with reasonable
frequency tend to rust in the stuffing-box gland and on the
threads of the packing nut. Piston rings in compressors
have given less trouble since the snap ring has been used.
While the installation of a relief valve in a bypass or in
a connection between the discharge side of the compressor
in front of the stop valve and the suction side of the com-
pressor in front of the suction stop valve will give pro-
tection against excessive pressure in the system, objections
against thi- practice have been voiced, and it is hoped that
the investigations into this phase of refrigeration safety
now being conducted will result in recommendations ap-
plicable without apprehension.
In compressing air the engineer should not use a
machine that has recently been used to compress am-
monia, and in opening gage-cocks it is safer to stand at
the side rather than at the front of the glass. Such pre-
cautions as standing at the side rather than the front of
compressor cylinders and refraining from calking pipes
or tightening nuts and fittings under pressure are general-
ly understood but often disregarded. Valve breakage is
the most frequent cause of compressor accidents and is due
principally to unnecessary wear, improper cushioning or
to deterioration of the metal.
680
hi w e i;
Vol. 41, No. 20
Care in testing initial installations of refrigerating
machinery is vitally important. Even though the equip-
ment it the factory and found satisfactory, a
further lest after assembly should be considered essential.
I ■ - customary to lubricate compressor-cylinder walls with
oil before starting a test, and more or less oil is forced into
the piping by the compressor, with resultant pocketing,
heating, vaporization and sometimes an explosion if the
temperature rise is extreme. Lubricating oil with a low
chill point.is desirable for regular use, but a high Bash
point is more important on account of the increased safety
of the latter. Gradual starting followed by cooling of
the compressor is a safer practice in testing than imme-
diate operation from standstill to normal or exi •
pressure. The use of butt-welded pipes or of unsupported
pipes is considered by many to be undesirable in refriger-
ating plants.
The device illustrated herewith is designed to stop a
pump when the tank is filled and to start it when the level
of the water lias fallen to a predetermined point.
The apparatus, Vis. 1. consists of a brass pipe, its
length being the distance between high level and low
level of the water in the tank. The upper end of this
pipe is supplied with a strainer, and a valve and copper
float are attached to the lower end. Xear the lower end
a fitting is provided to which an air reservoir is attached.
■i Continuous flexible
Copper Tubing from
Tank '-
4 Brass Couplii
4 Brass \
. P'Pe \
kfillinq
Pipe *~
'4Globe Valve
lit Plugged Tee
Regulator with extra large diaphragm
to operate under air pressure ranqinq
iromOtoBlb.
Diaphragm chamber filled rrith water
i Water
251b Pressure
Fig. 2. Regulator Connections
From the top of this reservoir a pipe is carried to the
top of the tank and thence by a flexible copper tube to
a damper regulator located near the supply pump. The
damper regulator is used to actuate a balanced valve or
other device for starting and stopping the supply pump.
The mechanism operates as follows : The water rising in
the tank to the top of the pipe overflows into it and com-
presses the air in the air reservoir. The pressure due to
the height of the water in the pipe is transferred through
the flexible copper tube to the damper regulator, and it
actuates the pump-controlling mechanism and stops the
pump. This pressure is held constant until the water
in the tank falls to the bottom of the pipe, when the float
valve opens and allows the water to escape, relieving the
air pressure: and the damper regulator acting in the
usual manner actuates the controlling mechanism and
starts the pump.
This apparatus has been in operation for four years
4 Brass Pipe
iSEh,
Top of pipe set 6
below present
over f ton from tank
Fig. l. Controlling Apparatus in Detail
or more and has proved reliable and satisfactory. It
was designed and installed by the Samuel M. Green Co.,
Springfield, .Mass.
Reducing Valves which are too large for the amount of
steam they are to pass are usually unsatisfactory. Either
they will open and close continually and chatter violently, or
will stand in a position nearly closed and become steam cut
and leaky. It is more satisfactory to use two small valves in
parallel, one set slightly heavier than the other, so that one
will supply steam up t<» its maximum capacity before the
other opens. Another way is to use one reducing valve equal
to about one-half the maximum demand, and a bypass of
about the same capacity with a hand-operated valve in it
so that when the reducing valve reaches its capacity the
bypass valve may be opened wide and the reducing valve
will close down and simply make up the shortage. This, of
course, requires that an attendant shall observe the pres-
sure gage occasionally.
May 18, 1015
POW E I!
681
"i
Tike Uir&uastuiail he& !Eimg|ii]nie@5Plinig|
Education
Operating engineers of New York City and vicinity
have recently had presented to there something worthy
ni comment in the way of engineering education, yet
the character of the presentation is centuries old and the
subject is indeed not new, though the proper recognition
of its importance is growing.
The subject is the central station versus the isolated
plant. The presentation is in the form of a three-act
play, with real engineering characters, telephones, charts,
records, instruments — everything, in fact, necessary in
depicting the problem of how an engineer, his employers
and the central station proceed with the business of set-
tling the question of continued isolated-plant service or
service purchased from the street.
The curtain goes up on the usual scene of a plant
where the engineer has tried to induce the management
to buy the instruments and equipment essential to ob-
taining and recording the data required to show the
performance of the plant, but where his requisitions
have been repeatedly turned down. The central-station
representative, being eminently fair, desires not to take
his legitimate advantage of conditions and suggests a
call after the plant has operated six months longer to
determine what it can do. The issue is forced and the
long-lacking equipment is obtained and, which is rather
important, used.
The end of the trial period sees a proud engineer, an
enthusiastic management, and a solicitor who, though
regretting his inability to "land" the plant, is frank in
his admiration of engineer and management. His little
discourse at the close of the last conference should be
learned "by heart" by every engineer and vigorously ap-
plied. It is the same old sermon about most isolated-
plant failures being primarily the fault of the engineer,
but a sermon whose value will decrease only as the need
of preaching it diminishes.
All things considered, the members of Brooklyn, Num-
ber Eight, National Association of Stationary Engineers
who conceived and who executed the idea deserve com-
mendation. There are some points which bring forth
criticism. But then, these men are not playwrights nor
trained actors, neither have they rehearsed or produced
sufficiently. Time will supply these needs.
To avoid impressions that impair the value of the
play, the members must be extremely careful not to seem
to advertise any particular make of apparatus. Some of
the slides shown during the consulting engineer's talk to
the superintendent do this too plainly, to the dissatisfac-
tion of many in the audience. But that this effect is not
intentional is evidenced by the fact that parts of the
"lines" which were similarly objectionable have been
changed, while the slides are undergoing like treatment.
When these features, which excite the critic, are removed,
the "company" will, in theatrical parlance, "put it over
great."
As a suggestion, we would add that when time permits
the evening might be made more valuable by following
the play with discussion of the question by audience and
players.
9!
M©rgninig Hs>-dlir©=EJe<c<hri<e
Hini&©5F@§(ts
The reported plan for merging control and ownership
of large hydro-electric and utility corporations in Mon-
tana, Washington, Idaho, Utah and Colorado will be
urged as an additional reason for the speedy enactment
of water-] mwer legislation, when Congress reassembles
next winter.
Secretary Lane of the Interior Department, father of
the fifty-year leasing plan for the disposal of water-power
sites in the public domain which was passed by the
House and allowed to die in Senate committee in the
last Congress, announced a few days ago that the leasing
bill would be reintroduced immediately upon the meeting
of Congress in December and expressed the hope that it
would, pass without further delay. Although the Sec-
retary did not say so, it is understood that the water-
power bill will be a part of the Administration's legis-
lative program next winter and that the influence of
the President will be used to force the measure to pas-
sage.
Consolidations and mergers said to be planned in the
states mentioned will place under single corporate con-
trol about fifty per cent, of the developed water powers
in the Western states. In commenting upon this situa-
tion, Secretary Lane said :
""Such a consolidation, involving widely separated
power plants, inter- and intrastate transmission lines
and Federal questions beyond the scope of state utility
commissions, emphasizes the necessity for Federal con-
trol and regulation in the interest of the public."
It is reported that the Electric Bond & Share Co.,
of New York, is the parent of the gigantic merger pro-
gram. The power which would come under the control
of the New York company by the consummation of the
several mergers that have been made this year or are
in contemplation would aggregate more than 5b*5,000
developed horsepower and about 150,000 horsepower of
undeveloped hydro-electric energy.
The Bond & Share Co.'s interest in the merger and
control of these Western power sites and plants is rep-
resented, according to reports, by a holding company
recently formed and known as the National Securities
Co. The Bond & Share Co., in turn, is known as a sub-
sidiary of the General Electric Co., and the completion
of the merger program will give the General Electric
practical control of the hydro-electric field west of Denver.
In the taking over of the Utah Light & Railway Co.
by the Utah Power & Light Co. some time ago, all the
important water-power plants in Utah were consolidated
into a single-headed system. The merger of plants in
682
row E R
Vol. 4], No. 20
on and Idaho now proposed, will similarly unite
the hydro-electric plants in these states, heretofore owned
by the following companies:
Developed Watki; Poweb
Horsepo\* er
[daho-Oregon Light & Power Co WOO
Idaho Railway. Light & Power Co 14.000
rdaho Power & Light Co 7500
Greal Shoshone & Twin Falls Water Power Co. .. 0000
Thousand Springs Power Co 3000
Southern Idaho Water Power Co 5000
These interests have heretofore been regarded as quite
divergent. The Idaho Railway, Light & Power Co.,
which operates the traction system in Boise, has for
some time been seeking a consolidation with the Idaho-
Oregon Light & Power Co., which docs a commercial
business in Boise. The Idaho-Oregon Co. was formerly
controlled by the Mainlands, of Oshkosh, Wis.. bu1 has
been in the hands of a receiver for some time, the receiv-
ership being forced primarily by the reduction of power
prices from fifteen to nine cents as a result of the en-
trance into that city of the Idaho Light & Power Co.,
in competition with the older concern. The Idaho Light
& Power Co. lias been trying to get into the Twin Falls
and Poeatello fields also, and there has been litigation
because of the action of the Idaho Public Utilities Com-
mission in permitting the company a "certificate of pub-
lic necessity" to enter Twin Falls and not Poeatello.
In the Utah merger, by which the water powers of the
state came under single control, there were involved
plants aggregating 112,850 horsepower of developed en-
ergy. The projected acquisition of the Washington Wa-
ter Power Co. by the same interests will give the General
Electric Co. control of the following companies in the
Northwest :
Developed Wateb Power
Horsepower
Montana Power Co 184,000
Washington Water Power Co loli.OOO
Pacific Power & Light Co 23.T50
Colorado Power Co 42,250
Utah Power & Light Co 112,850
Proposed Idaho merger 4.j,.j00
Total 5G4.:',.}0
The plan of merger proposes that shares of the older
companies shall be exchanged for shares of the new hold-
ing company, the National Securities Co., and that all
the plants will he operated by a big new company to be
organized for this purpose.
Among the power plants involved are those at Oxbow
on the Snake River and at Horseshoe Bend on the Pay-
ette, owned by the Idaho-Oregon Co. The Idaho Rail-
way, Light & Power Co. owns a power plant at Swan
Falls on the Snake River. Other plants included are
those at the Shoshone Falls on the Snake River and at
American Falls, Idaho. All these power sites were on
public land and were the property of the people of the
United States until within recent years, and practically
all of them passed into private ownership for a nom-
inal consideration and without qualification.
There is no control over water-power companies by
state utility commissions in Colorado. Wyoming, Utah
or Montana.
Without raising the question of whether the water
powers can best he developed by competition or by mo-
nopoly, advocates of the Ferris hill urged that the draw-
ing tighter of the lines of private monopoly emphasizes
the need for legislation now to protect the public's in-
terests in tin' power sites still remaining in the public
domain.
With half the power of the West under single control,
it is urged by Secretary Lane and other advocates of
the leasing plan and Federal regulation for power sites
in the public domain that the Government should per-
petually maintain a controlling hold upon these great
natural resources, the value of which is not yet fully ap-
prehended. It is pointed out by these same men that
state utility commissions cannot do much in protecting
public interests against such a great and powerful mo-
nopoly, which would lie sufficiently strong to dominate
the politic- of almost any of the states in which it op-
crate-.
A small number of Western senators and congress-
men who helped defeat the Ferris hill last winter, urged
that a leasing system would retard development, inas-
much as it would discourage investment of capital in
water-power enterprises, ami that what the West wants
is development at any price. In the face of the magni-
tude of the monopoly that will be created by the mergers
now projected, it is not believed that this position can
be maintained by this element.
"If the water power sites of the West are allowed to
pass into private ownership without restriction," said
Secretary Lane, recently, in discussing the matter, "it
is apparent that it will be practically impossible to reg-
ulate or control monopoly in this important resource
or to regulate this product in the interest of the con-
sumer. The possibilities connected with the utilization
of the water power of the United States are not at this
time realized, nor can anyone predict what changes in
the method of development and control will be required
by the public interest in the course of fifty or a hundred
years from now.
"I >ii]y by retaining the fee to these lands and rights in
the Federal Government ami a measure of control, can
the interests of the public, present and future, be prop-
erlv safeguarded."
Encouraging reports continue to come in showing the
favorable attitude of the various states toward the
American Society of Mechanical Engineers' Standard
Boiler Code. Thomas E. Durban, chairman of the Com-
mittee on Uniform Standard Specifications, of the Amer-
ican Boiler Manufacturers' Association and the National
Tubular Boiler Makers' Association, has received assur-
ances from J. D. Beck. Industrial Commissioner of Wis-
consin, that the State of Wisconsin will "stand by" the
recommendations of the committee to the fullest extent
and will publish the list of boiler makers who have
adopted the Code of the American Society of Mechanical
Engineers in the literature of the Commission, in order
to encourage the purchase of boilers from such nianu-
rers. Also an assurance by J. F. Sturgis, super-
intendent of the Boiler Department of the London
Guarantee & Accident Co., Ltd., that all specifications
furnished by that company to its assured will conform
to the A. S. M. E. Code.
May is, 1915 POWEB 683
a iiiiiiniiuiiiiiii iininiiiiiiiii iiiniiiimimiu iiiiunniiiimmuiOTi rmiinmnimmu iiiimimnnnmfflimpiniiiiiiiiiiiiiiiraiiiiiii i n in minium iiiiiiiiiiiiiniim n hiiiiiiiiiihiii n luiiiiiiiimnnninnmnnnninnnnnin iimi nt^
Corresp©imdleiniC(
m , i uumn i muni nm ilium ill i i i » mini iiim «
Lore S>p5Paffi}|g
mg
On a 24x48-in. Corliss engine exhausting into a baro-
metric condenser, the vacuum would not go over 22 in.
The trouble was located in the metallic piston-rod pack-
ing-; although it was a good tit on the rod, the tension
Brass Plugs ctndeb Springs
was insufficient. Brass plugs the size of the hole and
% in. long were put under the springs at A to increase
the tension. Now we have no trouble in maintaining a
27-in. vacuum.
Thomas Sheehan.
YYilliamstown, Mass.
QtuiSifffteir^TuflirEa Slhaffft GmapME&g"
In the Jan. 26 issue, page L17, there is an article on a
"Quarter-Turn Rod Coupling." which, it is stated, was
invented by C. P. Hall, of Chicago. Such an appliance
lias been in use many years and is known as the "Hobson"
patent.
James McClure.
Fletcher, X. C.
So Ear from the quarter-turn rod coupling being new,
1 know it to be at least twenty-five years old. A fisher-
man in a little town in Nebraska, where I lived when
a boy, carried such a contrivance around with him in his
pocket. It was made of two wooden spools and four
wires applied substantially as shown in Power.
C. 0. Saxdstrom.
Kansas City, Mo.
[The quarter-turn coupling referred to embraces the
idea of the Hobson patent, of which there are at least
two kinds. One consists of a Dumber of right-angled
rods which move in perforated guide flanges on the ends
of shafts and run at right angles, the rods drawing in
and out through the flanges as the shafts revolve. A
large angle rod serves as a center bearing. Another coup-
ling is made with lour angle rods which slide in holes
in the shaft coupling. The difference between this coup-
ling and that described in the Jan. 26 issue is that Mr.
Hall's coupling consists of six angle rods and the shaft
couplings arc made longer, so that when the rods are
fully extended the end comes at the center of the coup-
ling-, and when the rods are at their inner position they
come Hush with the inner end of the coupling. In the
" Hobson" patent, in one coupling the angle rods ex-
tend beyond the inner end of the coupling when at their
inner position, and in the other design but % of the
shaft coupling has a bearing on the angle rod when
extended. In these two respects the Hall coupling is
superior to the original patent, as a greater bearing
surface is obtained without the necessity of the objec-
tionable protruding angle rods. The principle of the
coupling is the same. — Editok.]
SaiWSimiiM I<Lin\§£iiiiti@©riffiijs|
A sawmill was binned down in northern Ontario, fifty
miles from a railway, and I was sent out to install a boiler
and engine in the new shack called a mill. There was a
55-ft. open well on the property, the water being about to
ft. from the ground level. The old pumping outfit bad
Pumping Rig Made from Fragments
been partly destroyed during the fire, and a new one was
not included in my employer's contract. The owner of
the mill said he would have enough water drawn from
the well in pails to fill the boiler and run a test. This
looked like a several days' job to me, so with the owner's
permission, after the cylinder from the deep-well hand
pump was found, although the bottom cap and valve were
missing, I rigged up an outfii as shown.
684
r<« \v i: r
Vol. 41, No. 20
The bottom of the cylinder extended to within a
of the bottom of the well, and the pipe was supported by
straps placed around it at several places. A shaft ex-
tended into the pump room, on which there was a pulley.
Another pulley with a hole drilled in one spoke was put
up over the well and connected to the pump as shown.
The first tankt'ul was raised by a couple of men pulling
on the belt to turn the pulley. The whole thing was put
together in about tour hours. I have never been hack
there (for which I am mighty thankful) but I suppose
they have a new pump, although that makeshift affair may
still be doing its day's work. It was not a noiseless outfit,
by long odds.
James E. Noble.
Toronto, Ont.
The comparison of the sale of electricity to that of ice,
by C. B. Seed, in the Mar. 16 issue, although meant to
justify central-station practice, illustrates, more than
anything else, the injustice of the system of rates in most
of the principal cities, as well as in the small towns.
To begin with, let us reconsider the example of Jones,
the ice man, together with the figures set forth by Mr.
Seed.
To harvest ice ^4 (for small consumers) :
Cost of labor per ton $1.00
Cost of machinery, house and equipment, per ton 1.50
Total cost per ton of ice ■: '-' 50
To harvest ice B (larger consumers) :
Cost of labor per ton $0.85
Cost of machinery, etc 0.85
Total cost per ton of ice $1.70
To harvest ice 0 (still larger consumers) :
Cost of labor per ton $0.75
Cost of machinery, etc. 0.60
Total cost per ton of ice $1 35
To harvest ice I) (wholesale consumers) :
Cost of labor per ton $0.70
Cost of machinery, etc 0.45
Total cost per ton of ice $1.15
Would it not be reasonably fair to all consumers, large
and small, if their rates were based upon the average cost
of labor, machinery, house and its other equipment? If
this were made the basis of rates for all, the total average
cost of the ice per ton, leaving out for the present the cost
of transportation, would he
2.50 -f- 1.70 + 1.35 + 1.15, or 6.70 -=- 4 = $1,675
The fairness of this assumption cannot well be disputed.
There is no logical reason why the small consumer should
be perpetually burdened with the first cost of the icehouse
and its equipment. Of course, the cost of transportation
will tend to change the rates somewhat, but transporting
ice is far different from the transmission of electricity.
A given amount of the latter cannot make any more trips
in a unit length of time to a few large consumers than it
•an to several smaller ones. It may be argued that there
is an extra outlay for wire in the latter case, but this item
in itself is not sufficient excuse for the great difference
in the rates to large and small consumers.
Mr. Seed states that the business of the large consum-
ers causes the whole lot to be cheaper. Yes, cheaper for
the large consumers. To further illustrate my point:
Suppose that Jones did not cater to the large consumers,
but secured several new small customers, which made it
necessary to build another story to bis icehouse. The
cost of ice per ton of lot A being $2.50 exclusive of trans-
portation, the cost of lot B per ton in this case would be
$1.70, which means that the new customers, although not
buying any greater quantities than the old one-, are get-
ting their ice for eighty cents less than the original cus-
tomers, without whom Jones would have had great diffi-
culties in starting in the ice business.
The foregoing does not sound fair, but it is virtually
practiced, as Mr. Seed's article proves. If Jones bad
been a fair-minded business man. instead of having high
rates for one set of his customers and low rates for another
set. be would lower the rates for the one and raise them
for the other until the rates of both were alike; that is.
(2.50 + 1.70) -+- 2 = $2.10.
Mr. Seed asks. "Which part of the business would Mr.
Jones drop!-'" Eet us see. If he drops the small custo-
mers .4. he will transfer the burden of the original cost of
the ice plant to the next smallest consumers, or B, and
will thus raise their rates from $1.70 to $2.50 per ton;
he would also have to raise the rates of the consumers ('
and D. But he is well aware of the fact that if he juggled
with the rates of these large consumers, they would all
proceed to install ice and refrigerating machines of their
own. He also knows that the small consumers A will not
install their own refrigerating plants, and that is why
Jones goes as far as he likes with these little fellows and
why he will not drop that part of his business.
Samuel L. Robinson.
Providence, R. I.
With no intention of questioning Mr. Seed's entire
sincerity in regard to central-station rates, I propose to
carry his analogy a little further and present another
view of the subject.
Jones cuts 1000 tons of ice at a cost of $2.50 per
ton and markets it at a cost of $6.15 per ton, and to make
a profit sells at $10 per ton. Smith and Brown, with
a new and modern plant, cut 1000 tons of ice at a cost
of $1.25 per ton and use it themselves. Jones, seeing
a wider field, installs a plant to handle a larger volume
of business at a smaller cost per unit of product and
proceeds to cut 4000 tons of ice at a cost of $1.15 per
ton, and which he markets as follow- :
A. Retail 1000 tons, costing $6.15 per ton for
delivery, total $7.30 per ton
B. Retail 1000 tons, costing $4.4S per ton for
delivery, total 5.63 per ton
C. Wholesale 1000 tons, costing $1 per ton for
delivery, total 2.15 per ton
D. Wholesale 1000 tons, no delivery, to Smith
and Brown 1.15 per ton
For the 1000 tons A he charges $S000, or makes a profit
of $700
For the 1000 tons B he charges $6000, or makes a profit
of 370
For the 1000 tons C he charges $4000. or makes a profit
of 1850
For the 1000 tons D he charges $2000, or makes a profit
of 850
Total profits $3770
Evidently. B is the least profitable and C the most
profitable part of his business, so Jones proceeds to in-
stall a new delivery system, so that
A costs $4 a ton for delivery, or a total of $5.15
B costs $2.50 a ton for delivery, or a total of 3.65
C costs S5c. a ton for delivery, or a total of
D costs nothing for delivery, or a total of 1.15
May 18, 1915
POWER
68.5
But Smith and Brown have now discovered that it is
cheaper for them to cut their own ice than to pay $2
per ton for it, and also that some of the class C business
is attractive and within their reach. Jones, being on
his job, proceeds to revise his price list all along the
line and then takes for
A. 1000 tons — $7000 (delivery and cutting costs $5150),
profit $1S50
B. 1000 tons — $5000 (delivery and cutting costs $3650),
profit 1350
C. 1000 tons — $3500 (delivery and cutting costs $2000),
profit 1500
D. 1000 tons — $1250 (no delivery and cutting costs
$1150), profit 100
Total profits $4800
and has not only increased his own profit but effectually
disposed of any competition by Smith and Brown.
Query: Would Smith and Brown get quite as good
rates if it were impossible for them to molest any of the
class C business?
Would Jones shade the price on class C business if
Smith and Brown persisted in cutting their own ice,
together with a surplus which they offered to class C
users ?
How long would Jones care for Smith and Brown if
he did not have the other three classes to produce his
revenue ?
Charles L. Ware.
Maynard, Mass.
Most engineers and firemen are not very skillful in
laying brick, but there are times when a few minutes spent
in pointing up loose brick with cement or fireclay when
the fires are out will develop a good job well done.
Getting fireclay or cement in between brick is not al-
ways as easy as it might seem. The illustration shows a
"Gun" for Pointing Up Side
sort of a square squirt gun with which you can fill up the
most obstinate crack or hole, and you don't have to be a
mason to do it, either.
We always keep on hand a little cement, and whenever
a crack shows up and needs attention it takes only a few
minutes to fix it, and the job is better than that usually
done with the time-honored trowel. Our original model
was made from a small tin can and a piece of a barrel
stave, which was used until worn out, when we had some-
thing suitable made by a tinsmith.
George C. Abbe.
Brooklyn, N. Y.
Si
Eira<cirea.sedl ftlhxe Capacity of tltae
In the plant where I am employed low-grade slack coal
was originally burned, because it was considered cheaper
at $1.35 per ton than screened lump at $1.85. Later on,
an increased load compelled the burning of the more ex-
pensive coal. About this time the price of fuel oil
dropped until it was considered more economical than
coal, when the grates were removed and an oil-burning
furnace put in. This was satisfactory until the price of
oil again became prohibitive. In the meantime the load
had increased until it was useless to replace the original
coal-burning furnace and expect to pull the load without
additional boilers.
The management, realizing conditions, allowed a self-
styled smokeless-furnace company to place its furnace
under one boiler with the understanding that it would
burn the poorest southeastern Kansas slack without smoke
or clinker. This furnace produced more smoke from
less coal than any other I have ever seen, and I have
not yet learned how to burn coal containing 18 to 22
per cent, ash and 5 to 7 per cent, sulphur content with-
out some clinker. The "patented smokeless furnace" did
not eliminate any of the natural ash content of the coal
and one was all that was needed.
It was necessary, however, to get back to burning coal
immediately, and on account of the low-set boilers stokers
could not be put in with any assurance of satisfactory
operation. Therefore, it was up to us to devise and put
in a hand-fired furnace that would deliver sufficient over-
load capacity to pull our constantly increasing load and
at the same time meet modern economic requirements
and compete with the central station.
The original layout consisted of four 250-hp. Heine
water-tube boilers set 5 ft. above the floor at the front
and 3 ft. 6 in. at the rear and baffled with T-tile which
exposed the lower half of the bottom row of tubes to
the flame. The boilers were connected to a steel-concrete
stack, 8 ft. diameter and 172 ft. high, which gave a
draft of approximately 0.9 in. of water at the dampers
and eliminated the necessity of using forced draft, pro-
vided sufficient air opening and grate surface were sup-
plied.
The grate surface was extended from 42 in. in length
to 56 in., using a shaking and dumping grate having 48
per cent, air space instead of 42 per cent. The T-tile
was replaced with a box-tile baffle which protects the un-
burned gases from the comparatively cool tubes during a
critical stage of combustion, which is completed by the
time the gases have passed through the combustion cham-
ber, provided sufficient air is admitted over the grates.
This feature was supplied by using a rather large damper
on the fire-door, the liner of which was perforated ac-
cording to common practice, and breaking up the air
prevents it from stratifying through the furnace. The
ashpits were lowered 6 in., which permitted lowering the
back end of the grates 10 in., giving them about the same
686
POWER
Vol. 41, No. 20
pitch as rh.1 bbilei tubes, and adding several cubic feet
tn tin1 combu .
A small amount of steam admitted under the grates
has a cooling effect on the molten ash and dampens that
already on the grates, thereby preventing the formation
ill' large (linkers. This makes it possible to clean the
fires by shaking the grates moderately at iy2- to 2-hour
intervals. This steam is supplied by a bleeder from sep-
arators on the power units, which were formerly trapped
into a feed-water heater. This trap, however, was almost
constantly discharging, and it was believed that, as the
feed -water heater was large enough to bring water to the
boiling point, the condensation would be worth more in
the ashpits than in the heater.
With this furnace we can develop 75 per cent, over-
rating, with but little smoke, burning slack averaging
10,000 B.t.u. and containing 18 to 22 per cent, ash and
cleaning fires once in twelve hours. Lump coal of about
11,000 B.t.u. and 10 to 12 per cent, ash is cheaper at
$1.85 per ton than slack at $1.35, and it is possible to
carry a heavier overload. The smoke seldom gets darker
than No. 2 Ringelman chart, and CO, averages lS1/^ per
cent., with no CO.
B. M. Babcock.
Pittsburg, Kan.
IE.3speirfl©ifiiC© Sim alia Isolaftedl Plaimft
The following experience of a friend was interesting
to me and may be to others :
"Eight return-tubular boilers with hand-fired furnaces
furnish steam for a manufacturing plant with a load al-
most uniform throughout the twenty-four hours. Various
steam-saving appliances had been employed in the engine
and dynamo room, but we had never received any special
consideration out in the boiler room.
"A so-called efficiency expert had given the plant at
large a general going-over, but about all the effect we
felt was to have the force cut down and the consoling
news that our department was wasting more money than
other plants of this class. Our superintendent was deeply
engrossed in what he termed the 'output' end of the busi-
ness.
"Our chief engineer was well along in years and not
very favorable to 'theoretical steam makers !' One day
the superintendent came into the boiler room and with
him our engineer and a young man who was a stranger.
The young man said little, but nothing escaped his
scrutiny; dampers, draft, coal, ashes and our methods of
firing. I felt quite curious and a little uneasy. Sure
enough, the next day we heard that the steam plant was
to be shut down and city current used. Our engineer
said he was powerless to help us as the central-station
representatives had shown that it would be decidedly ad-
vantageous to buy current, and that the superintendent
had decided to try it. There were 12 men in our crew,
who would have to look for new jobs and we were a
gloomy bunch.
".Since being put in charge of the boiler room I had
been studying up on flue-gas analysis, draft regulation,
etc.', with but little encouragement from my chief. As
it appeared that we were to lose our jobs anyway, I
pleaded with the chief to make a last effort with the office
for our plant. With courage born of desperation, I told
him the plant deserved to be shut down on account of our
wasteful habits, and that our methods were crude, etc.
He took me with him to the office, where the superinten-
dent received us cordially. The chief said nothing, but
simply turned me over to him. With nothing to lose, I
made a straight drive for my point — that with the proper
instruments and boiler-room methods our plant could pro-
duce power cheaper than the central station. The out-
come, without the details, was that arrangements were
made for a three months' trial for which we were supplied
with a set of gas collectors, differential draft gages on all
the boilers, a new damper regulator and provision for
forced draft. Team work and head work also played a
large part.
"The draft was kept at what was found by experi-
ment to produce the best combustion. Different fuel-
bed thicknesses were found to require different draft and
different ash-pit pressures to get the C02 up to the bonus
line. We were determined to make a success of it and did.
A bonus system was established among the firemen, the
charts were gone over each week and a bonus declared
in proportion to the percentage of saving. In this way
the firemen were made stockholders in this economy en-
terprise. At the end of three months, the trial period al-
lotted, every fireman had developed into an efficiency
expert.
"We never knew what the city-current fellow's figures
were, but at the expiration of our three months' test we
knew we had won. We found that the greatest source of
waste we had to overcome was excessive draft !"
Edward T. Binns.
Philadelphia, Penn.
)SiEffiipe'iP
LeM^H^on*
In the Apr. 13 issue, page 517, is a letter from Henry
W. Geare on this subject. Mr. Geare seems to assume
that by some means or other he determines how much
air is required to burn a certain kind and quantity of
coal per square foot of grate per hour, and then arranges
to pass sufficient air through to hum this coal. Of
course he does not say how this is determined, and I
believe he would find it difficult to determine. If, how-
ever, he did determine it once, it would not be the same
the next time he tried to do it, as the quality of the coal
would vary.
Further on in his letter is the statement : "It will
be found that under that close regulation with natural
draft a much more uniform and higher average CO, can
be maintained, and the efficiency of the boilers increased,
with the resulting saving in coal." Much more uniform
and higher than what? Further on he states that "the
results with natural draft are nearly equal to those ob-
tained by a balanced draft system without the use of
blowers;'' which I assume is intended to be a general
statement and rather broad in application. What is a
balanced draft system without the use of blowers? He
concludes by saying that "a balanced draft system with-
out the use of blowers increased [and now he refers to a
particular case] the cost of power required to operate
such systems." What systems?
V. H. Cakples.
New York City.
May IS, 1915
POWER
687
A Fs°es^ ft© ftlh© Oemmeirsfts
It is usual to see the bright side of transmission lines
illustrated in articles on the subject, but sometimes there
is something of value to be derived from their failures.
In the present case all the details of the transmission
hue were worked out most carefully by government engi-
neers, these were checked up, and then followed the con-
struction, inspection and testing. The towers were put
up. tested, and everything done that high-class engi-
neering practice considers desirable. This line ran from
the celebrated Roosevelt dam to the neighborhood of the
Inspiration Copper Mining Co., in Arizona, and passed
over a part of the desert in that vicinity.
The line was in service for some time and no more
thought was given to its safety, when suddenly about a
year and a half ago there arose in the desert a terrific
storm that blew and battled, as storms on the Arizona
desert can, and soon showed its disregard for engineer-
ing and the government and laid about two miles of
OxE OF THE TOWEKS AFTER THE STORM
poles or towers to the ground. The condition of one of the
towers is seen from the photograph taken shortly after.
It will be noted that the tower is clearly buckled and
that the rivets and holding parts are still intact. In
certain places breaks appear to exist, at first glance, but
closer inspection shows that these are the ends of the
cross-angles.
A. P. CONNOB.
Washington, D. C.
A liquid weigher. Fig. 1, failed to operate when the
temperature of the feed water became as high as 200
deg. P. The vapors arising from the water evidently
formed air pockets in the siphons, causing loss of suction,
consequently, the buckets would not drain sufficiently to
allow them to turn to the proper position to be refilled.
This difficulty was overcome by making two steel crank-
shafts 21/2 in- diameter, and extending from the center
of the weigher through the side walls, and attached to
the dashpots on the outside. These crankshafts have
a oi/o-in. throw and revolve in bronze bearings mount-
ed on the channel beams supporting the bedplate. An
arm, or lever, extends from the shaft to the bucket,
being fastened between the two short pieces of channels
under the bucket, Fig. 2 ; these channels serve as buffers
between the bucket and bedplate. A hole 3 in. diameter
was cut in the bottom of the bucket and a special valve,
Figs. 3 and 4, made to fit this hole.
After the bucket is filled and tilts the water is turned
into the other bucket by the deflector with which the
weigher was originally provided, and the valve stem is
raised by striking a strip extending across the weigher
some distance below the bottom of the buckets. After the
water has been emptied into the reservoir the bucket
Helical spring to return
stem to proper position
Fig. l.
Section of Weigher Showing the Siphon
and Dashpot
returns to its normal position to he refilled, and the valve
stem is forced back into its proper position by the helical
spring. Should leakage take place through this valve,
it can lie stopped by increasing the tension of the spring
by means of the nuts on the valve stem.
The size of the valve required will, of course, depend
upon the time available for one bucket to empty and
return to its filling
position. The 3-in.
valve mentioned al-
lows a bucket con-
taining 485 lb. of
water to empty and
return to its normal
position in from 33
to 37 sec.
Any sort of regis-
tering device can be
used to count the
number of buckets
dumped in a given
time. An ordinary
street-car register
can be connected so
that each time a
bucket is emptied it
will be recorded on
this register. The
amount of water
necessary to tilt a
bucket can be deter-
mined by filling one
and allowing it to
empty into a barrel
mounted on a pair of
scales. As the buck-
ets are usually filled through one weir, the total amount
of water consumed will be the product of the number
of buckets emptied, the pounds of water contained in
each bucket, and the number of weirs.
After making the above changes the weigher was
tested several times before being put into service. The
water dumped by the buckets was weighed and the
SECTION A-B
Pig. 2. Section of Valve
for Liquid Weigher
688
POWER
Vol. 41, No. 20
maximum variation differed from the average of a dozen
trials by less than one per cent.
The principal advantage of the weigher (which is
a Worthington) as it is now. over the original one, is
that there will be no loss of suction on account of the
formation of air pockets as there is no siphon effect.
The buckets will return to the proper position to be
refilled, enabling the operators to keep an accurate record
of the total water consumed. Also, the dashspots will
give less trouble, as they are no longer submerged.
J. W. Loef.
Ft. Worth. Tex.
Effects ©f TlrMr®&&Sedl Eiadl£<e&ft©s»
CocEi
During a test on an ammonia compressor a number of
diagrams were taken whose areas gave a capacity smaller
than the machine should have developed. These dia-
grams were similar to those shown in Fig. 1. The re-
expansion line appears, which would indicate a large
amount of gas in the cylinder at the end of the stroke.
Diagrams Showing Effect of Throttled
Indicator Cock
In this particular machine the compressor cylinders were
single-acting and there was every reason to believe that
there should have been a constant pressure line throughout
the stroke and a diagram similar to Fig. 2 obtained.
Investigation and experiment showed that if a series
of diagrams were taken, one after another, with the indi-
cator cock opened a little more each time, diagrams with
widely varying areas could be obtained. Further experi-
ment showed that diagrams varying from that shown
in Fig. 4 to that shown in Fig. 2, depending on how
much the cock was opened, could be taken. The reason
for the cock not being fully opened was that in trying to
have the least possible amount of ammonia escape, the op-
erator feared to open it. Instead of getting an intake line
at constant pressure, the line obtained would indicate a
decrease of pressure as the stroke progressed. This was
due to the failure of the indicator mechanism to respond
because of the reduced opening through the valve.
Sidxey K. Eastwood.
Owego, N. Y.
SftgcF&iiirsgg sua Oldl D^imsunm©
A moving-picture man in a small Western town got
hold of an old direct-current dynamo which he wished
to use with a traveling motion-picture show, his plan
being to drive the machine from a rear wheel of an auto-
mobile.
The dynamo had lain around for many years and it
was a question whether it was in operating condition.
As the "movie" man had had some trouble with the
local light plant's electrician, he did not feel like calling
on him for advice, so he called in a fellow who posed
as being every kind of a mechanic. The latter turned
on the power and got the machine up to speed, but
could get no sign of electricity from it. He then pro-
ceeded to test out with a storage battery, and finally
announced that the fields must have been burned out
and that it would be an expensive job to put the machine
in running order. The movie man hated to give up
the project and, as the lighting company's electrician
had the reputation of being an expert, he decided to try
to get him. The electrician responded reluctantly and
after calling for the battery used by the other fellow,
made the same field tests, but refused to make a positive
statement about the machine.
That evening a friend of the movie man chanced to
overhear the electrician say that it would not take him
fifteen minutes to get the dynamo to generate. The next
day this was repeated to the movie man, who immediately
called for the electrician again and told him what he had
heard. The electrician confessed to making the state-
ment and agreed to make the trial. He connected six
cells of a dry battery in the field circuit for an instant
and then brought the machine up to speed, and when the
proper connections were made the dynamo lighted up an
incandescent lamp nicely.
The machine refused to generate in the first case be-
cause it had lost its residual magnetism and the resist-
ance of the fields was so great that the storage battery
could not send enough current through them to be noticed
or to make a spark. When the electrician made the test
he wet his fingers and made and broke the circuit, so that
when the circuit was broken through the wires it was
complete through his fingers. There was enough in-
ductive kick to be felt and to show that the field circuit
was all right, though no spark could be seen. The six
dry cells were sufficient to magnetize the fields enough
to give the machine a start.
The movie man was greatly pleased, but still had
things to learn about electricity. The next day he
brought the picture machine around and proceeded to
try it out. The dynamo generated nicely until he
switched on the arc, when the voltage suddenly died
completely. All attempts to get a sign of an arc across
the carbons were futile, so once more the light company's
electrician was appealed to. Only one question was
asked — ''Did you use your rheostat the same as when
using the company's power?" The answer was, "No."
May 18, 1915
POWER
689
He was told to do so, with the result that an arc was
had without further trouble.
As the dynamo was a plain shunt machine, when the
carbons were in contact there was a dead short-circuit
across the brushes and nothing to force any current
through the field ; therefore, the field died and there was
no voltage to produce the arc. When the rheostat was
in the circuit this resistance prevented the current from
flowing through the outside circuit until the voltage was
strong enough to build up the field.
G. E. Miles.
Denver, Colo.
Dir&wiiag? IFeedU'Wa.fces' Samples
For taking representative samples of water from the
boilers we have found the fol-
lowing to give best results:
Each water-column blowoff
pipe has an extra valve near
the boiler-room floor, and a
pet-cock is connected as
shown. To obtain a correct
sample the bottom valve is
opened first, then the one di-
rectly beneath the column is
opened to blow out the col-
umn.
The bottom valve is closed
first, then the top one. Af-
ter the sample contained in
the section between the valves
has had time to cool, it may
be drawn off at the pet-cock
into any convenient recep-
tacle.
Edward T. Binns.
Philadelphia, Penn.
Piping for
Drawing
Sample o f
Feed Water
'"J
H-J-
Ca
nag Fnp>e luea
In a certain power plant subjected to a working pres-
sure of 100 lb. the lines have given considerable trouble
from leakage in the threads. The flanges on the 10-in.
main are extra heavy, with the pipe screwed all the way
through and peened. In peening these flanges the erector
simply beat down the outer edge of the pipe or, rather,
riveted it over, but did not peen the full width of the
flange. This does not make a good job and prevents the
flanges from being taken off, as it tears the threads.
These leaks could be stopped temporarily by calking,
which was done in the following manner: A calking
tool was made with a bit about % in. wide, then a small
groove was cut in the flange with a narrow chisel and
this recess calked full of tinfoil. This would stop the
leak for a few days, until it worked around the thread to
a new place. Some of them were calked all the way
around.
The most troublesome leaks were in some short pieces,
which were replaced with new ones.
In making the new pieces a full clean thread was cut
long enough to screw in the full width of the flange when
tight, and to the same taper as the thread in the flange.
No "dope" except machine oil to reduce the friction was
used in making up the joint, and the pipe was not peened
or beaded in the flange. Several nipples were made up
in this way and every one gave entire satisfaction without
a leak. Some of the other leaking joints were taken down
and the entire surface of the joint peened with a heavy
ball-peen hammer, but in a few months they were as bad
as ever.
The steam line is level and properly drained, with
hangers placed not over 10 ft. apart and adjusted to
equalize the load on each, but there is some vibration.
Steam is not shut off except at long intervals, and there
is ample provision for expansion. The principal cause
of the trouble is poor workmanship, as those sections, put
in properly, give no trouble.
I believe that for ordinary pressure a flange joint
should not be peened, and that no "dope" should be
used except good oil, because a metal joint is what is
wanted, and this cannot be had if the thread is filled up
with pipe compound.
Our experience has demonstrated that a plain screwed
joint, properly made up, will hold better than a peened
joint.
J. C. Hawkins.
Hyattsville, Md.
Si
TLJira^is^aaS PSs&ona Failtmre
The piston in our 26x48-in. Corliss engine had a piece
of metal of some description left inside when it was
plugged up, and after three years of service it worked
through the piston on the crank end and was caught
between the piston and head, as indicated in the illus-
tration. No damage was done except slightly bending
Piston Wall Worn through
the piston rod. The engine was not shut down for a
couple of days, but right after the accident it began
pounding badly on the crank end. An indicator dia-
gram was taken, which showed the usual conditions in
the head end, but high terminal pressure on the crank
end and low compression. It was at first thought that the
exhaust-valve stem had twisted, but after studying the
diagram it was decided that it would be impossible for
the stem to be twisted so that it would lower the com-
pression and raise the terminal pressure. The piston was
removed and a hole 1^x1^4 in- was discovered at the
bottom of the piston. This was bored out and filled with
a 3-in. pipe plug and the diagram was all right.
If any Power reader has had a similar experience 1
would be pleased to hear from him.
J. W. Dickson.
Memphis, Tenn.
690
pow k i;
Vol. 41. No. 20
FilHiRkg* Holes in Coinniinnitiatt&ftoiF
The commutator on a 200-kw. generator contained
numerous holes which were constantly filling with car-
bon and copper dust and short-circuiting the segments,
with the result that the holes were constantly growing
larger. All the well-known methods for filling holes
in commutators were tried, but the filling would stay
in only a short time, and it did not seem to make any
difference what pains were taken to clean the holes be-
fore the mixtures were put in ; the filling would blow
out just the same.
If more time had been available it might have been
possible to try something different, but as this was
the only source of supply except a storage battery, it
could not be shut down for any length of time.
The commutator contained 95 segments, and there was
hardly a bar that did not show some kind of hole. They
varied from pin holes to the largest, which covered
three-quarters the width of the bar and was y2 in. deep
and about % in. long. Some were situated as at A.
Fig. 1, while others were on the extreme end of the
segments, as at B, Fig. 2.
While turning the commutator would have helped to a
certain extent, as it would have taken out many of the
small holes, it was not advisable, as enough could not
be turned off to take out all the holes without weaken-
ing the commutator; also, it would have been a waste
of copper, and there probably would not have been
enough carrying capacity left in the segments to take
care of the current.
As more load was to be added in a short time, the
manager decided to purchase another generator. After
wiring the old machine so that it could be run in par-
allel with the new one, and while waiting for a pulley,
it was decided to see what could be done with the com-
mutator. It was thought best to take it apart and put
in new mica. Two straps of y^xl-in. iron were bent
around the commutator as at A, Fig. 3, a %-in. space
B being left at the top. Two bolts 0 were inserted to
clamp the strap which, in turn, held the commutator
in place after the end-plate had been removed. After
taking off the end-plate the bolts were loosened on the
straps and the mica between two of the segments was
removed and then used as a pattern for cutting the new
stock.
Then someone proposed that the holes could be filled
with solder, each segment being treated separately, so
as not to cause a short-circuit. The question of the
commutator becoming hot enough to melt the solder
was discussed, but as it had not got hot enough in the
past to melt the solder at the leads, little apprehension
was felt.
First one, then the other of the straps around the
commutator, was moved to the segment that was to be
taken out, the opening in the strap coming directly over
the segment. After unsoldering the leads the segment
was moved to the first strap, and the bolts were taken
out to allow the ear of the segment, which was higher
than the strap, to pass. The bolts were then put back
and tightened, and those of the other strap taken out,
so that the segment could be removed.
AVliere the holes were not too large they were filled
with solder, the segment having been heated with a blow-
torch. On some of the largest holes the segment was
laid down flat and a dam of clay built around the hole.
The segment was then heated and the hole tinned, and
enough solder melted to fill it. After cooling, it was
filed off level so as to conform to the rest of the segment
and was put back in the commutator. What is commonly
known as "hard solder" was used. About thirty seg-
ments were treated.
The new mica was put in where needed, and after the
leads were soldered on the segments the end-plate was
put on and the straps taken off. The commutator was
then turned, as it was out of round and the new mica
projected above the bars. It was also the means of re-
moving numerous small holes which were not filled with
solder.
The commutator was still running at the end of five
years and had given no trouble.
Leox L. Pollabd.
Fairfield, Maine.
■"ape
The overflow water from sealing glands, etc., of high-
vacuum apparatus should in all cases be so piped as to
be visible to the operator, who can then determine the
amount required. He can also detect the presence of
undue leakage. A lot of work in one instance was re-
quired to locate the cause of a drop in vacuum when the
Overflow
^.Special
Flanges
Through bob
Six on Ipipe'
Sight Glass in Place
overflow was not so piped to a feed-water heater, but if
there had been a sight glass, the absence of water, indi-
cating the presence of a leak, could have been noted.
When the apparatus is drained by gravity it is a sim-
ple matter to place an open funnel in the line, and where
the discharge is under pressure a sight glass can be made
as shown in the illustration, using special flanges and a
glass from a pressure oil cup with gaskets and through
bolts.
Johx F. Hurst.
Louisville, Ky.
May 18, 1915
P 0 W E B
691
The nuts on stuffing-box studs sometimes cause quite
lot of annoyance by working off. The illustration
lows how I remedied the trouble in a satisfactory man-
iT.
In tightening or loosening the nuts all that is required
to slip the pin out. It is a very easy matter to remove
Slot
1\
Slotted Stud foe Pin
and replace the pins while the engine is in motion, be-
cause it is not necessary to have the hole in the nuts or
the slot in the stud so tight that the pin has to be driven
in or pulled out with pliers. A flat wire or key is better
than a round one. There is no likelihood of the slot'
closing and allowing the nut to slip over the threads.
J. B. Proctor.
New Orleans, La.
worn in over a quarter of an inch on the flange of the
barrel. This continual hammering for several years
caused the studs to give way. A new barrel was made and
new studs with sufficient thread inserted.
The plunger rod was cut off just inside the collar and
threaded. A forging was made which was turned to fit
the plunger and looked like a bolt with a large round
head bored and threaded to receive the rod, as shown in
Fig. 3. A jam-nut was first placed on the rod, as there
was enough clearance to accommodate it. The pump now
runs better than it did before.
George H. Wallace.
Racine, Wis.
m castes' aiac
AccIdeHTift fta
Inl©w IFLepaitiredl
A three-million gallon duplex triple-expansion water-
works pump in a near-by pumping station was a "thorn
in the flesh" of the chief engineer ever since it was in-
stalled— some eight years previous to the accident. Af-
ter being in service about three months, it developed a
mild pound on one side that was finally traced definitely
to the water end, but repeated inspections failed to reveal
the cause of the trouble.
The water end, which was of the inserted-barrel type,
is shown in the illustration. As there are but few parts
in the water end, there seemed to be no reason for the
trouble, and several inspections showed that the jam-nut
was not loose. The noise became more distinct with time,
until the fatal day when the studs B, Fig. 1, which held
the plunger barrel in place, broke ofi: on one side so that
r ^ ~ — •
<CyMifiidletr°EiIeg\e>l
On board a Transatlantic steamship we had 8 sets of
8xl0-in. fan engines for forced draft. They were located
in a hot place over the main boilers. The boilers primed
frequently, throwing the water into the steam pipes, and
several of the cylinder covers were smashed. In one in-
stance the flange was broken so that a new cover could
dabbiH-
L
CYLINDER COVER
NUTS
Wooden Plug Held in Place with Jackscrew
not be bolted on, so we trimmed a block of wood down to
fit the bore of the cylinder and, with a sheet of asbestos
around it, pressed it down into the cylinder with a screw
WEZ_
— . _
Fig. 1. Original Condition
Fig. 2. Plunger Barrel Displaced and Bod Broken
on the out-stroke the thrust of the rod forced the plunger
and barrel off at an angle, as shown (exaggerated) in
Fig. 2. This broke the plunger rod off close to the collar.
Upon removing the wreckage the cause of the pound,
and also of the accident, was apparent. When the studs
B were put in at the shop, the threads were not chased
down far enough to permit drawing the nuts up against
the flange of the plunger barrel, with the exception of
three or four which were on one side at ('. These held
the barrel in place for a few months, and then lost mo-
tion began to appear at A, and grew worse until it had
jack, as shown in the illustration. The engine ran for
10 clays, until we reached port, with very little escape
of steam.
To prevent the cylinders breaking again we bored out
the nuts on the cylinder covers y± in. and filled them with
babbitt metal, then tapped them out. In case of water
in the cylinders it only stripped the soft metal out of
the nuts, which were then replaced with new ones and
no damage was done We carried a number of these nuts
all ready for such emergencies.
New Westminster, B. C. John Dobson.
692
POWER
Vol. 41, No. 20
Spring- Wiiir&dl£ir&|gg FissfcTLaire
The illustration shows a spring-winding fixture. Re-
gardless of the diameter of the rod the spring is to be
wound on, the tension is adjustable and the strain is taken
up by the fixture itself. It is made from a piece of ma-
chine steel ^xl^xli in. long with a 45-deg. slot in the
end, and drilled to receive a i/o-in. stud, and a standard
4S°-
Position of Fixture in Use
%-in. wing-nut. Drill a hole (say % in.) in the stud
close up to the head, and the fixture is complete. To wind
an open spring the tool is held in the tool post, getting
the lead required by the lead screw, the same as for any
other purpose. Closed springs are wound with the fixture
held in the hand and the wire will give its own lead.
F. L. Young.
Pittsfield, Mass.
The illustration shows the arrangement of the exhaust
piping, and a heater which was a source of danger that
no one had ever noticed until after the head was blown
out, resulting in the death of one man.
There were a number of steam traps discharging into
Cngines
Heater without i Relief Valve
the heater at B, and it was customary to partly close
valve .4 in case the water became too hot. This valve
had an inside screw stem and one could not tell how nearly
it was closed except by counting the turns made by the
wheel. Just before the accident the feed pumps would
not handle the water, so the water tender gave valve A
a few turns to throttle the exhaust steam. The valve
had evidently been left partly closed by the previous
watch, so that with the few more turns it was completely
closed. As there was then no means of escape for the
steam from the traps, an excessive pressure was built up.
Some of the traps were out of order and the bypass
valves were open, which allowed steam to enter at full
boiler pressure. One of the heads was blown out and
broken into several pieces. Later, all the heaters weie
fitted with relief valves.
I have seen this same condition in one other plant,
which leads me to believe that it may be a common over-
sight. I think all heaters should be fitted with some
form of relief valve.
H. A. Dempsey.
Michigan City, Ind.
Water°Level Cojmthrol
A mechanism for controlling the water level in tanks
is shown. It is adapted to all kinds of water-supply tanks
and can be installed at small cost. It consists of a throttle
valve A operated by the electric solenoid 0, which is con-
trolled by a float switch B in the water tank. This switch
consists of a brass spring to which is soldered the wire S,
Solenoid
Supporting
Brx*cke+(BrasS)
Float and Solenoid Control System
a varnished wood float E, in the center of which is fixed
a rod C with a ball end to make contact with the spring
and guided by the arm D to which is soldered the wire
T. Wire K is soldered to C and D to insure a good con-
nection. The solenoid operates the valve through which
steam enters to operate the pump.
The operation is as follows: As the water level in the
tank lowers, the float E descends, closing the electric cir-
cuit, throwing the solenoid into operation, opening the
steam valve to the water pump; when the pump has
raised the water level in the tank to its required height,
the float rises, opening the switch releasing the solenoid,
and allowing the spring L to close the steam valve.
F. B. Hays.
Indianapolis, Ind.
May 18, 1915 PO VV E R 693
gin ii win mil mi iiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiii inn iniiiiiiiiinii i iiiiiiiii iiiiii m i n iiiiiiiiiu mini i iNiiiiiiimiiiiiiiiiiimiiimiiiiiiiiiiiiiiiiuiiitj
Eimqpuiiiiries ©f (Qeinieiml 31 miter estl
ilium iiiiiiiii! in . "i r,i
Rattling of Exhaust Va
isp of the exhaust valves o
len running light or when
Ive is closed?
■* —What causes the milling
noncondensing Corliss engine
ning to rest after the throttle
R. H.
lder the conditions stated the initial volume and pressure
lam or air in the cylinder may be so small that expansion
■s below atmospheric pressure, and the .valves thus be-
unseated by the pressure ot the atmosphere.
Clearance — What is the difference between piston clearance
d cylinder clearance?
J. W.
Piston clearance is the distance the piston would have to
moved beyond the end of its stroke to strike the head of
* cylinder, and is usually expressed in linear inches, while
linder clearance is the volume of all the space between the
iton at the end of its stroke and the valve face, and is
ually expressed as a percentage of the volume displaced by
! piston in one stroke.
Obtaining Same Point of Cutoff with Increase of Spet-d —
After increasing the operating speed of an engine, how would
the same point of cutoff he obtained foi the same load?
C. H. M.
Increasing the speed would require less mean effective
pressure, and as with the same point of cutoff there would be
the same average pressure per pound of initial, then the in-
crease of speed for the same load and point of cutoff would
require a reduction of the initial pressure, obtained either by
throttling or by reduction of the boiler pressure.
Determining llrake Power with Indicator — How can the
brake horsepower of an engine be determined by use of an
indicator and without applying a prony brake?
E. R. M.
The friction of an engine is practically constant for all
loads, and as the brake horsepower is the net power devel-
oped by the engine, then for all practical purposes the brake
power of the engine could be ascertained by determining the
highest indicated power it would develop with any kind of
load and deducting the power indicated when the engine is
doing no other work than overcoming its own friction.
Operation of Automatic Cylinder Lubricator — In ordinary
forms of automatic sight-feed cylinder 1 jbricators, how is the
pressure of the oil increased so as to force it into the engine
steam pipe against the same pressure of steam as that re-
ceived by the lubricator?
A. A. G.
The condensing chamber of the lubricator is connected by
a pipe or passage to the lower part of the oil chamber and,
in addition to the steam pressure communicated through the
condensing chamber connection, the oil pressure is increased
by the pressure due to the head of water of condensation
Which accumulates in the condensing chamber and its con-
nections.
Allowance for Thickness of Plate — What length of %-in.
boiler plate would be required to form a cylindrical shell 66
in. outside diameter, with butt joint?
>; w. t.
In bending the flat plate into cylindrical form the side
that is concaved becomes compressed, the side that is con-
vexed becomes extended and the neutral axis is at the center
of the sheet. Therefore, the length of the plate will be equal
to a circumference whose diameter would be measured at tin
center of the thickness of the plate. As this is equal to the
outside diameter minus the thickness, and as the diameter
measured at the center of the plate would be 66 — >/2, or
65% in., the length of Vi-'n. plate required for 66 in. outside
diameter would be
65 % X 3.1416 = 205.774S, or about 205 35 in.
Decrease in Weight from Ii
mersed in water, why is its w
of the volume of water displai
imersion — When a body is im-
eight decreased by the weight
depth, If we imagine all these pressures resolved into hori-
zontal and vertical pressures, the horizontal pressures are in
equilibrium, while the vertical pressures are unequal ami will
tend to move the body upward, for the vertical pressures are
directly in proportion to the depth. The vertical upward
pressures passing through any point in the body will exceed
tlie vertical downward pressure by the weight due to the
height of the column of water which is displaced. It follows,
therefore, thai the total upward pressure will exceed the total
downward pressure by the weight of total volume of water
which is displaced.
Water Horsepower of Pump — A triplex pump, having
plunders in i, in diameter by 24-in. stroke and taking its suc-
tion at atmospheric pressure, made 32,200 revolutions during
10 hours' run, pumping against ISO lb. gage pressure per sq.in.
What was the average water horsepower
horsepower hours?
id the number of
With three plungers and 32,200 revolutions, during 10
hours' run there would be
32,200
3 X = 161 strokes per minute.
10 X 60
The cross-sectional area of each plunger would be
10.25 X 10.25 X 0.7S54 = 82.516 sq.in.
and each plunger making 2-ft. stroke and pumping against
130 lb. per sq.in. the water horsepower, without allowance for
slippage, would be found by substituting in the usual formula,
P X L. X A X N
Hp =-
the values P
Hp.
33,000
130, L = 2 ft.. A :
130 X 2 X 82.516 X 161
33,000
'discounted" by the percentage of slippage.
82.516, N = 161; that if
= 104.67 hp.
This must be
which can only be known by actual test. Allowing 5 per cent
slippage, the average water-horsepower would he
104.67 X (1.00 — 0.05) = 99.436
or for the 10 hours' run, 994.36 water-horsepower hours.
Height to Which Water Can Be Forced by Steam Pump —
To what height can water be forced by a direct-acting steam
pump where the steam piston is 8 in. diameter, the water
piston 5 in. diameter and the steam pressure 80 lb. per sq.in.?
F. J. B.
In estimating the height due allowance must be made for
back pressure of the exhaust and the loss of total effective
pressure of the steam in overcoming friction of moving parts
of the pump, difference of atmospheric pressure exerted on
the suction and discharge sides of the water piston, and pres-
sure required for overcoming friction of the water, depending
on its velocity through the pump, pipes and passages. These
losses depend on the design, construction, adjustment and
operating conditions. Assuming that 20 per cent, of the steam
pressure is employed for overcoming these losses, then 80
per cent, of 80 lb., or 64 lb. per sq.in. of the steam pressure,
would be available for operation of the steam piston in over-
coming the static pressure due to the height to which the
water is forced. As the area of the steam piston is
8 X 8 X 0.7854 = 50.2656 sq.in.
the total pressure available for this purpose would be
64 X 50.2656 = 3216. 99S4 lb.
and as the area of the water piston is
5 X 5 X 0.7S54 = 19.635 sq.in.
the static pressure pumped against could be
3216. 99S -=- 19.635 = 163.84 lb. per sq.in.
At the ordinary temperatures of water, each pound pressure
per square inch would be equivalent to the pressure created
by a column of water about 2.3 ft. high, and therefore, for the
conditions assumed, the pump would force the water to a
height of
163.84 X 2.3 = 376.83 ft.
Every part of the surface of the submerged body
tted to a perpendicular pressure which depends
[Correspondents sending us inquiries should sign their
communications with full names and ppst office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR]
694
POWER
Vol. 41, No. 20
Finals. L-sialbs'icsiSniragi ©51 Ftpgiuadls
Still Alive
f The following is taken in its entirety from the pages
of the American Machinist in the hope that it may come
to the attention of some intended victim before he is
separated from anv real money. — Editor.]
Those who remember the exposure long: years ago. in
1884 to be exact, by the "American .Machinist" of the alleged
lubricant put out by Henry (sometimes known as John)
Fink are likely to be surprised to learn that he is neither
dead nor sleeping, but is still on the job. although his field
of endeavor has been removed to the Southwest and the
Pacific coast. Nor has his method changed particularly, as
was discovered in a recent visit to one of his railroad victims.
Taking care to keep away from the mechanical depart-
ment, he approached the executive offices with a fine collec-
tion of alleged testimonials handsomely bound in morocco
covers. These and his winning ways, backed by the apparent
evidence, secured the cash.
In this particular instance, the mechanical superinten-
dent was an old reader of the "American Machinist" and
also possessed of an excellent memory. As soon as the
recipe, which had already been bought and paid for by the
executive department, was sent to him, he recognized it as an
old friend — or enemy. Making a few extracts from the "Am-
erican Machinist" of 1SS4-5, he sent them to the executive
offices to show how badly they had been stung. The formula
is practically identical with the one purchased and is given
below.
Since then he has answered a number of inquiries from
railroad and other shops along the Pacific coast as to the
value — or rather, the lack of value — of the lubricant, for
as soon as Fink secures a victim he immediately turns
him into a club to force others into line.
GUARDING AGAINST SIMILAR ATTACKS
For the information of those who do not remember the
original exposure and who wish to be thoroughly armed
against being victimized, we refer to the bound volumes
of the "American Machinist" for 1SS4-5-6. The original
article will be found on page 7 of the Mar. 22, 18S4, issue;
the others following on page 57, Apr. 12; page 4, May 10;
page 7, July 12. and page S, Dec. 27.
The following year tells of his Canadian exploits, his in-
dictments, and the inability to find him when suits were
attempted.
He was written to regarding the compound before the
first article appeared, but instead of proving his claims, he
answered: "We hereby notify you that any item your paper
may publish which will injure us in any way we shall most
certainly hold your paper responsible for."
The best-known firms in the country fell victims to
his wiles, paying from ?100 to $700 for the recipe. After
being bitten themselves, they came forward with letters
relating their experiences, instead of allowing others to
become victims owing to ignorance in the matter. Publicity
is the best safeguard against such methods, and we shall
be glad to hear from all recent victims, in order that the
fame of Fink may precede him and make his efforts un-
profitable, if nothing more.
DIRECTIONS FOR MANUFACTURING FINK'S PATENT
LUBRICATING OIL MIXTURE
To make 48 or 50 gal. of the mixture, take 15 to 17 lb.
best lump lime, 22 oz. pulverized french chalk, 20 oz. carbon-
ate potash, 16 oz. calcine magnesia, and 20 oz. pulverized
borax. Put these ingredients into a barrel with the head out
and add three or four buckets of hot water. After all are
dissolved, fill the barrel with cold water, stir the mixture
thoroughly and let it settle for about seven hours. After it is
perfectly settled and clear, mix the clear water of the mix-
ture with the oils you now use, in the foliowing propor-
tions.
For engines and cylinders take 17 gal. of lard or cylinder
oil, 3 gal, of castor or machine oil, 20 gal. of clea: mixture,
or 40 gal. clear mixture to give it more body. To lard oil
or any animal oil or greases: Light oil, mix one-half oil and
one-half clear mixture. Heavy oil, mix one-third oil and two-
thirds clear mixture.
To mix any kind of machine or black oil. take 15 gal. of
any kind of machine or black oil. 5 gal. of lard or animal
oil or cheap grease, 20 gal. of clear mixture, or 40 gal. of
clear mixture to give it more body.
These proportions may be varied or changed according to
the oils or greases used, the climate, or for various reasons
to suit the machinery where oils or greases are used.
Put these ingredients into a barrel with the head out and
stir them with a paddle. Do not stir the mixture more than
once. Use nothing but clear mixture to mix with oil.
If not strong enough add more ingredients to the barrel
of mixture. Rinse the barrel before making a new quantity
of mixture. Throw away the settlings in the bottom of the
barrel of mixture before making a new quantity. Use the
best lump lime and the softest water that can be procured
in the manufacture of the mixture.
For paint oil or paint would advise the use of one-half fl
linseed "i paint oil and one-half mixture. Then use same as
pure oil for painting. For wood oil use same as lard or
Perhaps this may sound familiar to some of the victims
of long ago.
Lecesaft Co^airt Deelsioias
Digested by A. L. H. STREET
Child Labor in Alabama — Under a law enacted at the
present session of the Alabama legislature, and approved by
the governor Feb. 24, 1915, it becomes unlawful to employ
any person under 16 years of age in operating or assisting
in operating any steam boiler or dangerous machinery.
Use of Streams for Power Purposes — A power company
authorized to condemn private property in the conduct of
the company's business is not entitled to interfere with the
navigable capacity of any of the navigable waters of a state
unless such interference is authorized by statute. But it
may take the private rights of property of a riparian owner
upon complying with the constitutional and statutory provi-
sions relating to the condemnation of private property. (Min-
nesota Supreme Court, in re Otter Tail Power Co., 151
"Northwestern Reporter," 198.)
Duty to Safeguard Power Machinery — Under the Iowa
statute that requires every employer to safeguard dangerous
machinery when that is practicable, a stationary engineer
cannot be deemed to assume the risk of his employer's
failure to safeguard setscrews on revolving shafts connected
with pumping machinery. But where an employee relies
upon failure to provide guards, he has the burden of estab-
lishing the fact of their absence. Then the burden shifts to
the employer to show that it was impracticable to safeguard
the machinery in the particular instance. (Iowa Supreme
Court, Winn vs. Town of Anthon, 150 "Northwestern Reporter"
1036.)
FRANK W. BALFOUR
Frank W. Balfour, district manager of the Southern Cali-
fornia Edison Co., died Apr. 25, at Pomona, Calif. Mr. Balfour
came to this country from England in 18S6 and was em-
ployed in the city engineer's office in Los Angeles. He had
been with the Edison company for fifteen years and was its
first district manager.
GEORGE L. BAULDRT
George L. Bauldry, chief engineer of the plant of Walter
Baker & Co., Dorchester, Mass., died at his home on May 4
after a week's illness with pneumonia. Mr. Bauldry was born
53 years ago at Bourne, Mass., and learned the machinist's
trade in New Bedford. Later, he was a member of the Hart-
ford, Conn., fire department. In 1S99, after a varied experi-
ence, including service with the New York, New Haven &
Hartford R.R., he entered the Walter Baker plant as a fire-
man. By hard study in night school he worked his way
upward and in eight years he became chief engineer of the
company. In addition to his engineering duties, Mr. Bauldry
bore important resposibilities as a citizen. He "was a member
of the Milton Warrant Committee for two years, and also
recently on the committee charged with motorizing the local
fire department. A few days before his death he was ap-
pointed a member of the board of fire engineers. He "was
affiliated ■with various Masonic and engineering organizations
and is survived by his widow, a brother and a sister.
A. R. I DICK) FOLEY
"Dick" Foley is dead. When the "Lusitania" received her
fatal blow and plunged into the sea off the Irish Coast, Fri-
day, May 7, she took Dick with her.
Mr. Foley, known to all as Dick, probably had as large a
circle of friends among engineers and supplymen, both here
and abroad, as any other can claim. For about 15 years he
was connected with the Home Rubber Co., which deeply
feels the loss of one so influential in building up its business.
As his friends know, Mr. Foley had made many trips abroad
for that company.
Mav 18. 1915
row E i;
695
Engineering organizations, especially the National Asso-
ciation of stationary Engineers, have few friends more loyal
and helpful than was Mr. Foley. He was a member of the
Trenton. N. J., Association, N. A. S. IS., and made his home in
that city, at 713 Hamilton Ave. The works of the company
he so long served is also in that city. He was one of the
A. B. Foley
'.-: Association of
oldest members of the National Supply]
the N. A. S. E
Mr. Foley was in the 'ally raj's. He was born in Englai;
came to this country at the age of 21 and settled in Bostc
He is survived by a widow, one son and two daughters. V
understand that his body will be shipped to Trenton f
burial.
J. E. Woodwell has remove, 1 his office to S West Fortieth
St., New York City, where he will continue the practice of
consulting engineering.
H. S. Collette, secretary of J. G. White & Co., Inc., and
The J. G. White Engineering Corporation, has resigned from
these companies, and expects to reside permanently in Cali-
fornia.
R. J. S. Pigott, formerly mechanical construction engineer,
Interborough Rapid Transit Co., New York, has been made
power engineer for the Remington Arms-Union Metallic Cart-
ridge Co. at Bridgeport, Conn.
Frank H. Williams has resigned his position with Sperry
& Barnes Co., New Haven, Conn., to accept an appointment as
chief engineer and master mechanic at John Morrell Com-
pany's plant at Sioux Falls, South Dakota.
Prof. W. H. Kavanaugh, head of the Experimental Engi-
neering Department, University of Minnesota, has been
appointed a member of the International Jury of Award, De-
partment of Machinery, at the Panama Exposition, San
Francisco. He is spending the month of May judging exhibits.
Joseph McNeil, who is well known as a former chairman
of the Board of Boiler Rules of Massachusetts, and who re-
cently has had charge of the inspection department of the
Boston office of the Hartford Steam Boiler Inspection & In-
surance Co., is now stationed in the New York office.
O. L. Remington, general manager, and H. P. McColl, engi-
neer, of the Wm. McLean Co.. importers, Melbourne, Australia,
are visiting the industrial centers of the country. They are
making a study of machinery and apparatus devoted to power
uses and have established temporary headquarters at the
Hotel La Salle, Chicago.
G. L. Fales has become associated with the Raritan Cop-
per Works, Perth Amboy, N. .1. Mr. Pales was formerly su-
perintendent of power, Tennessee Copper Co., Copperhill,
Tenn. When he left the latter concern, its employees gave
him a fine silver service as a mark of their high esteem and
good will. The readers of "Power" will remember him as a
contributor of several interesting articles on boiler oper-
ation.
The National laiiociatlon of Cotton Manufacturers held its
annual meeting :it the Copley-Plaza Hotel, Huston, Apr. 28
and 29. The business sessions were devoted to papers and
discussion on concrete construction for cotton mills and on
the dyestuff situation as affecting the cotton industry.
\. s. M. !•:. Legislative Work At a recent meeting of the
Council of the American Society of Mechanical Engineers it
was decided thai the society's representative on the con-
ference committee of tin- United Engineering Societies be
present at the state constitutional convention and cooperate
with tin- representatives of the other engineering societies in
anj matters bearing upon their mutual interests. It was
also moved that a committee of five he appointed to formu-
Eat< general principles for the guidance of those who may
s, rve Hi-' society in a representative cai ity, and particu-
larly when dealing with public questions.
Two Awards by the Franklin Institute — The City of Phila-
delphia, acting on tlie recommendation of the Franklin Insti-
tute, has awarded the John Scott Legacy Medal and Premium
to Herbert Alfred Humphrey, of London, Eng., and to Cav.
Jul- Alberto Cerasoli, of Rome, Italy, for the Humphrey pump,
a device for raising water by the direct application of the
( xplosive energy of a mixture of combustible gas and air.
The Edward Longstreth Medal of Merit has been awarded to
the late George A. Wheeler for his escalator (an inclined.
elevator for transporting persons from one level to another).
The basic invention "was first disclosed in a patent granted to
Mr. Wheeler in 1S92, and a number of patents were subse-
quently issued to him for improvements and developments.
HEW PUBILHCATHOHS
DIRECT-ACTING STEAM PUMPS. Bj F. F. Nickel. Pub-
lished by the McGraw-Hill Liook Co'., Inc.. New York, 1915.
Size 6x9 in.; 258 pages; 21S illustrations. Price, $3, net.
This book had its basis in a course of lectures delivered
by the author before the students of Columbia University. It
is not a treatise on pumping machinery in general, but, as
the title implies, is confined exclusively to the direct-acting
steam pump. Doctor Nickel's experience, extending over
thirty years in this line, not only fits him to speak authorita-
tively on the subject, but has enabled him to weave into the
text much first-hand information concerning the development
of this type of pump.
In descriptive matter it is not unlike two or three other
books on the subject, although the greater number of illustra-
tions render it, perhaps, more complete in this respect. The
treatment of such subjects as the duplex valve motion and
compounding are original; the chapter on performance fac-
tors, distinguishing between different efficiencies, heads,
speeds, etc., is particularly instructive. The text is sup-
plemented by a large number of tables covering pipe-line
friction, steam forces and duty, and a chapter on the oper-
ation and adjustments of direct-acting pumps will be found
useful, especially by the operating man.
JOURNAL OF THE AMERICAN SOCIETY OF HEATIN'd AND
VENTILATING FN' '.INFERS
The American Society of Heating and Ventilating Engi-
ne, i s has issued the first number of a quarterly journal.
According to the editorial announcement, the new publication
is not inten'ad to replace the annual volume of "Proceed-
ings, but lather to present in advance papers to be given
before the society. It will also offer a medium for a closer
interchange of ideas between members by publishing dis-
cussions on the papers, questions asked and answers sup-
plied by the members on any subjects of interest to the or-
ganization 'I'll.- headquarters of the society are at 29 West
Thirty-ninth St.. New York.
Sherwood Mfg. Co.. Buffalo, N. Y. Catalog No. 16. Oil
pumps, injectors, ejectors, etc. Illustrated, 20 pp., :PLx6 in.
The Deming Co. Salem, Ohio. Catalog J Power pumps.
Illustrated. 190 pp.. 7x9 in.
696
POWER
Vol. 41, No. 20
The Jeff rev Mfgf. Co., Columbus. Ohio. Bulletin No. 141.
Single roll coal crusher. Illustrated. 32 pp., 6x9 in.
The Watson-Stillman Co., 50 Church St., New York. Sec-
tional Catalog Xo. 92. Hydraulic forcing pumps, etc. Illus-
trated, 12S pp., 6x!i in.
"Engineering Bulletin Xo. 10" — The Peterson Power Plant
Oil Filter and Accessory Apparatus for Central Oiling Systems
is the title of a 32-page catalog recently issued by The
Richardson-Phenix Co. of Milwaukee, Wis. This catalog
describes the construction and operation of the new Peterson
Power Plant Oil Filter, and it is stated that filters of this
type having a total capacity of over 1,500,000 gal. are now in
operation. Curves are reproduced showing the results of
some interesting tests made on oil taken from one of these
niters, and a chapter on the necessity of using filters in
connection with steam-turbine oiling systems contains much
new information. The catalog contains fifty illustrations
showing many important installations of Peterson filters and
oiling systems. Copy may be had by addressing the company.
BUSHMESS ETEM^
John F. Hale, formerly with the Warren- Webster Co. of
Camden, X. J., has associated himself with the Consolidated
Engineering Co. of Chicago.
To meet the continuously increasing demand for Peerless
specialties, the Peerless Rubber Manufacturing Co. has moved
into larger quarters at 31 Warren St., New York.
The Jeffrey Manufacturing Co., Columbus, Ohio, has moved
its New York Branch from 77 Warren St. to 50 Dey St. George
H, Mueller, assistant sales manager of the company, is in
charge of this office.
The Richardson-Phenix Co., Milwaukee, Wis., has purchased
the patents, good will and manufacturing rights of the
Osborne "XoKut" valve and is now carrying a complete line
o« the various valves in stock. Literature describing the
"XoKut" valve is sent on request.
The annual meeting of the stockholders of the Joseph
Pdxon Crucible Co. was recently held in the company's office
in Jersey City. Following are the directors elected: George
T. Smith, Robert E. Jennings, George E. Long, E. L. Young,
William G. Bumsted, J. H. Schermerhorn, Harry Daily. The
officers elected by the Board of Directors are: President,
George T. Smith; vice-president, George E. Long; treasurer,
J. H. Schermerhorn; secretary, Harry Daily; assistant secre-
tary and assistant treasurer, Albert Xorris.
HEW EQU1FMEHT
ATLANTIC COAST STATES
The Edison Electric Illuminating Co., of Brockton. Mass.,
has applied for a permit to build a new substation on Ames
St., Brockton. The estimated cost is $3300.
Recent press reports state that the town of Reading. Mass..
has decided to extend its municipal electric-light service to
Lynnfield, North Reading and Wilmington. The estimated
cost of the work is $12,000. Arthur G. Sias. 179 Main St.,
Reading, is Mgr. and Supt. of the Reading municipal electric-
light plant.
The H. B. Ives Co.. Artizan St.. Xew Haven, Conn., is hav-
ing plans prepared for a one-story, brick and steel. 24x44-ft.
boiler house, and a 125 -ft. stack. R. TV. Foote is Arch.
The Eureka Flint & Spar Co.. Trenton, N. J., is having
plans prepared for the construction of a one-story, 36xS5-ft.
power house.
The Ebensburg Light, Heat & Power Co., Ebensburg. Penn.,
is preparing to install one 800-hp. Blake & Knowles open
feed-water heater and one Worthington duplex feed pump.
E. F. Craver is Gen. Mgr. and Cont. Agt.
The Eastern Pennsylvania Light. Heat & Power Co., Potts-
ville, Penn., contemplates increasing the output of its plant
at Palo Alto, a suburb of Pottsville. by 20(10 hp. The esti-
mated cost of the work is $200,000. W. B. Rockwell, Potts-
ville, is Mgr.
SOUTHERN STATES
Press reports state that the Lynchburg Traction & Lieht
Co.. Lynchburg. Va„ has appropriated SS5.000 for rebuilding its
transmission lines. It also contemplates enlarging the Black-
water St. station. J. W. Hancock is Gen. Mgr.
The Parkersburg, Marietta & Interurban R.R. Co. has
selected a site in Parkersburg. W. Va., for the location of its
new generating station to replace the present power house.
The building will be 135x150 ft., and the completed plant is
estimated to cost $500,000. Sanderson & Porter, 52 William
St.. Xew York, X. Y., is Engr.-in-Charge.
Press reports state that the Baton Rouge Electric Co.,
Baton Rouge. La., will build a new power plant to cost about
$200,000. Donald St. w; I .- Mgr.
It is reported that the Xew Orleans Rv. & Light Co., Xew
Orleans, La., will spend about $125,000 in enlarging its power
house on Market St.
The Kentucky South-Western Electric Ry.. Light & Power
Co.. Paducah. Ky„ will build a new power house in connec-
tion with its traction line from Paducah to Murray. Kv. F.
M. Smith is Gen. Mgr.
CENTRAL STATES
Bids will be received until noon. May 24, by the Board of
Education, City Hall. Cincinnati, Ohio, for the installation of
electric-lighting systems in the College Hill School on Maple
Ave. College Hill, and the Mt. Airy School, Colerain Pike and
Mt. Airy ltd.. Cincinnati. C. \V. Handman is Business Mgr.,
Bd. of Education.
The Hilliards Light & Power Co., recently organized at
Hilliards. Ohio, with a capital stock of $10,000. will install an
electric-light plant to supply the town with electricity. Le-
Etoy Bobyns, T. C. Latham and others are interested.
The Ohio Gas & Electric Co.. Lisbon. Ohio, recently or-
ganized, plans tn establish an electric-light plant in Lisbon.
Joseph S. Grayden is interested. Service is now furnished by
the Xew Lisbon Gas Co., which purchases energy from the
Youngstown & Ohio River R.R. Co.
(Official) — Bids will he received until noon. May 29, by the
Board of Trustees, .Miami University, oxford, Ohio, for alter-
ations and additions to the power plant of the University. The
work includes boiler- and engine-room extensions to power
building, boiler, feed-water heater, vacuum heating pumps.
boiler-feed pumps, power equipment changes and additions.
W. L. Tobey, Hamilton. Ohio, is Chn. of Bldg. Com. of Bd. of
Trustees. Walter G. Franz. Union Trust Bldg., Cincinnati, is
Consult. Engr.
The City Council. Painesville. Ohio, has reiected the terms
of the Cleveland. Painesville & Eastern R.R. Co.. Willoughby,
Ohio, to furnish electricity to the city of Painesville. and has
authorized ; n issue of $35,000 in bonds, the proceeds of y. hich
will be used to make improvements and buv new equipment
for the municipal electric-light plant.
The City Engineer, Ann Arbor. Mich., has submitted ten-
tative plans to the City Council for the installation of a
municipal power plant for lighting the streets and public
buildings of the city. The estimated cost is $55,585. Manly
Osgood is City Engr.
It is reported that the town of Elizabeth. 111., is consider-
ing the establishment of an electric-lighting system. It is
stated that the sum of $8000 has already Deen subscribed
for the purpose.
WEST OF THE MISSISSIPPI
It is reported that a company is being organized to install
and operate an electric-lighting system in Ute, Iowa. The
estimated cost is $10,000.
The City Council of Hays, Kan., is considering the es-
tablishment of a municipal electric-light plant. The esti-
mated cost is $27,000.
Bids are being received by the village of Ceresco, Neb.,
for the installation of an electric-light plant to cost about
$5000. G. Johnson is Village Clk. Grant & Fulton, Lincoln,
is Engr.
Bids will be received until May 17 by the Arillage Clerk of
Morrill, Xeb.. for the installation of a municipal electric-
lighting system for the village.
A special election will be held in Tekamah. Xeb., on May
IS to vote on the question of issuing $15,000 in bonds for the
purpose of establishing an electric-light and power plant
M. S. McGrew is City Clk.
At an election held Apr. 26, the citizens of Victoria, Tex.,
voted in favor of issuing $40,000 in bonds for the purpose of
installing a municipal electric-light plant.
It is reported that the Texas Power & Light Co., Dallas,
Tex., has purchased the local electric-light plant at Windom.
Tex., and will improve the property. F. R. Slater, Dallas, is
Gen. Mgr. of the Texas Power & Light Co.
Bids will be received until May 24 by the City of Montrose,
Colo., for the construction of a municipal electric-light plant.
It will cost about $6000. E. T. Archer & Co., Xew England
Bldg., Kansas City, Mo., is Engr.-in-Charge.
The Mt. Konocti Light & Power Co., Lakeport, Calif., plans
extensions and improvements to its plant to cost about $9000.
The city of Tehachapi. Calif., has voted to issue $8000 in
bonds, the proceeds of which will be used for the installa-
tion of a municipal electric-light plant.
CANADA
It is reported that the Toronto Electric Commission, To-
ronto, Ont., will build a new substation at Carlaw Ave. and
Gerrard St.. at an estimated cost of $65,000.
iittons Wanted. 3 cents a word, minimum charge 50c. an insertion, in advance =
Positions Open. [Civil Service Examinations) . Lmplovment Agencies (Labor i
Hn.inLss Op port ii ni [its, w anted (Agents arid Salesmen — Contract =
\\ i.rk). Miscellaneous I :ducational— Books). For Sale, j cents a word, mini- 1
iium! charge, S1.00 an Insertion. =
("mint three words for keyed address care of Xew York: four for Chicago I
Abbret lated words or symbols count as full words.
Copy should reach is not later lhan 10 A.M. Tuesday for ensiling week's Issue =
Answers addressed I" our run*, 'tenth Ave. at Tbirty-si\th .street. New York or =
1144 Nfonadnork block, < liieago will be forwarded (excepting circulars or I
similar literature). |
Xo Information given by us regarding keyed advertiser's name or address. |
Original letters of recommendation or other papers or value should not be In* |
closed to unknown correspondents. Send copies.
Ad vertlsements calllnji for bids. 53.60 an Inch per Insertion. P |
FOSSTIOHS OFEH
CHIEF ENGINEER wanted, one familiar with turbo-gen-
erators and Harrisburg engines, D.C. and A.C. power, also
must have experience and know good boiler practice; must
be able to do necessary repair work and make boiler tests;
location, mining town 75 miles from Pittsburgh; salary $110
per month to start; married man preferred. P. 506, Power.
POWER
M) ^ ''-\
I If I
Vol. II NEW YORK, MAY 35, 1915
iiMiiiir. inir i minium i n nil in i iiiiini iiiiiinii iiiiiiiiiiiiiiiiiiiiiiiiiumi
No. 21
minim mil urn iiiiiiiiiiiminn
©w to Braim^ Dowin th.<s (Gs\ina<
■*S£S
ftfla
s w^srifg&s*©
weapons® as legp
(598
^Frisib^ari
POWER
,00 Railway ^mi(
TO)
Vol. 41, No. 21 '■
Bv Thomas Wilson
SYNOPSIS — A 2000-kw. condensing turbine
plant supplying current for an interurban line,
for a number of mine* and for lighting. A soft-
ener and purifier converts hard, muddy and corro-
sive water into excellent boiler feed at a cost of lc.
per 1000 gal.
On the middle fork of the Saline River (more com-
monly known as the Big Muddy), two miles from Harris-
burg, 111., the Southern Illinois Railway & Power Co.
built its power plant. It has Been in operation more
than a year, supplying current at 1200 volts to a single-
track interurban line running from Eldorado to Carrier
Mills, a distance of 16 miles. The intervening stations
are Wasson, Muddy, Harrishurg, Dorrisville and Ledford.
The cars are run on hourly schedules, and in the morning
and evening hours extra service is given to convey the
miners to and from their work. Arrangements have
been made with the Illinois Central railroad for inter-
line freight service twice a day. and the coal for the
plant is hauled over the company's line.
Three-phase 60-cycle current is generated at 2300 volts,
and by motor-generator sets this is transformed into
1200-volt direct current for the railway. Current for
power and lighting is stepped up to 33,000 volts through
-— -
^
:^V"-*3HH
Fig. 1.
Harrisburg Plant of Southern Illinois Ry.
& Power Co.
Fie;. 2. View in Turbine Room
Stay 25, 1915
P 0 W E K
699
two banks of three single-phase water-cooled transformers
connected in closed delta. At the receiving end H is
stepped down to 2300 volts. The Wasson mines, which
are electrically equipped, take service. They require di-
rect current at 250 volts for cutting, hauling, etc., and
this is obtained through a motor-generator set. Through
Pig.
Motob-Geneeatohs Supplying Railway Load
three-phase, 60-cycle, 2300-voH generators at 3600 r.p.m.
Condensers arc of the surface type, cadi containing 3600
sq.ft. of surface, or 3.6 sq.ft. per kilowatt of generator
rating, and served by a reciprocating dry-vacuum pump,
a motor-driven centrifugal pump and a steam-conden-
sate pump. Each circulating pump has a capacity of
3000 gal. per min. The sucti E each connects to a
20 in. intake running wesl from the plant to a crib in
the storage reservoir. The latter circles to Eorm a IT,
so that the discharge IV the condensers is received
south of the plant at a distance of about one-quarter
mile Erom the inlet. Spray nuzzles arranged in clusters
of five help tn cool the water, and in any event a con-
siderable period of lime elapses before the water from
the condensers gets back to the intake. The total lift
for the pumps is 8 ft. The condensate is pumped to a
1600-hp. open heater, where its temperature is raised I'oi
boiler feeding.
It is evident that one generating unit will carry the
load, operating at a small overload at the peaks and at
a load factor averaging about 40 per cent, the remainder
of the time.
Fig. -4. Sectional Elevation through Engine ind Boileb Rooms
a distributing company light ami power arc furnished
to Harrisburg. Carrier Mills is also lighted, ami tin
transmission line has been extended recently to Marion.
Average Lo ld
At present the load will run about 1 1,000 kw.-hr. a
day. At the peak hours the load is about 1200 kw., but
owing to the mine and traction loads, it is erratic. From
midnight to I : 30 in the morning it will not exceed 500
kw., as the service- are reduced to street lighting and
mine ventilation.
( I EN BEATING CAPACITY
The plant has a capacity of 2500 kv.-a., or, at 80 per
cent, power factor, 2000 kw. This is divided into two
units consisting of two-stage horizontal turbines driving
Excitation is furnished by two exciters, one driven
by a motor and the other by a turbine, although the
Eormer is used lor the most part. Usually, one of the
300-kw. motor-generator sets carries the railway load,
but in the evening it is accessary to use both. The
switchboard is fully equipped with modern instruments,
hand-operated oil switches for the 2300-volt current and
remote control for the high-tension service. Leads from
the switchboard are c lucted underground in vitrified
tile conduit to the transformer building located near tin
plant.
Boileb Plant
To serve the -.'000 kw. in generating capacity there
is 1600 hp. in boiler-, a rati.) of 5 to i, or one boiler
roo
P 0 W E R
Vol. 41, No. 21
horsepowei per I1 ', kw. The boilers are of the vertical
water-tube type, contain 3977 sq.ft. of heating .surface,
and are rated at 400 lip. Dry steam at KiO lb. pressure
is supplied to the turbines. Stokers of the top-feed
type serve the boilers. Each grate has a projected area
of 64 sq.ft., which bears a ratio of 1 to t>2 to the boiler
Fig.
Spray Xozzt.es in Action
heating surface. This is high when compared to the
average 1 to 50 ratio, hut as the prates are set at about
45 deg., the actual area is considerably greater than the
64 sq.ft. given above. The stack rises 155 ft. above the
ground, or 135 ft. above the grate level. With a gas
forcing at the peaks one boiler could carry the load,
but a second is carried under bank to be ready for emer-
gencies. Under these conditions, combined with the
low load factor on the generating units, the operating
efficiency is low. From 5 to 6 lb. of coal is required
per kilowatt-hour.
The coal is pulled over the company's track from El-
dorado. It is dumped into a 30-ton hopper under the
siding at the plant. From the hopper it passes through
a crusher, which is operated only for lump coal, into a
horizontal screw conveyor. A bucket elevator hoists it
to the top of the boiler room and a second screw con-
venor distributes it to 20-ton bunkers, one on top of
each furnace. Ashes are wheeled from the pits to the
elevator boot and are delivered to an ash screw at the
top, which discharges them onto a temporary platform
outside the plant, from which they may be wheeled into
the empty coal cars. It is the intention to install a
pneumatic system which will convey the ashes directly
to the cars or a tank located beside the track.
Unusable Watki; Transformed into Excellent
Boiler Feed
One of the most serious problems the plant had to
contend with was the water-supply. The water is taken
Fig. 6. The Boilers and Water
Purifier
Fig. 7.
Pump Room, with Chemical Tank of
Purifier in Foreground
temperature of 500 deg., the draft at the stack should
be about 0.85 in. of water. Making the usual deductions
for drop through breeching and setting, the draft over
the fire for the boiler farthest from the stack should be
about 0.25 in. and on the first boiler 0.35 in.
The stack, which is of concrete, is lined 50 ft. up. An
internal diameter of 8 ft. gives a sectional area of 50
sq.ft. At eai h boiler the breeching is enlarged until
at the stack it reaches a sectional area of (!0 sq.ft., the
width being ■"> ft. and the height 12 ft. For each square
foot of stack there are 1.2 sq.ft. of breeching, 5.1 sq.ft.
of connected grate surface and 32 boiler horsepower.
Coal-Handling Facilities
The fuel burned is Saline County screenings. The
thickness of the fuel bed is maintained at 3 to 5 in.
on the inclined grates and 8 in. ou the bottom. By
from the Big Muddy River, which is well named, as the
water retains its yellow, muddy color even in the reser-
voir, where it has a chance to settle. Besides containing
;' large amount of suspended matter, at certain seasons
it is exceptionally hard and at all times is of a corro-
sive nature due to the acid drainage from the mines. A
short period of operation showed that it would be neces-
Fig. s. Chart Showing Hardness or Water After
Treatment
.Mav 25, 1915
en w E i;
701
sary to install a water softener and purifier, and this
was dune in the spring of 1914. The apparatus has a
capacity of 2000 gal. per hr. The water from the res-
ervoir is first pumped to a 25,000-gal. elevated tank.
from which it flows to the top of the softening equip-
ment by gravity. Here it is treated with 90 per cent.
hydrated lime and 58-test soda ash, the proportions being
irned by tests made twice a day. The chemicals
neutralize the corrosive and scale-forming ingredients
in the water and precipitate them in the form of insolu-
ble matter. After the chemical treatment the water is
allowed to settle and is then passed through a gravity
quartz filter which is an integral part of the apparatus.
Thence it Hows by gravity into the feed-water heater
and is pumped to the top drum of the boilers, although
provision is also made to feed through the blowoff.
It might be stated that the river is one which varies
greatly in its flow, depending upon the seasons of the
year. For this reason the quality of the water varies
widely, and the softener had to be adapted for accom-
NONINCRUSTING SOLIDS
Sodium sulphate 12.06
Sodium chloride 14.32
Total nonincrusting solids 26.3S
Total solids 29.94
The cos! lor treating tin- water has averaged about le.
per Kioo gal. It varies directly with the hardening in-
gredients in the water, but runs from 11/oc. per 1000
gaL, which is the maximum, t» thine. as the supply
al times contains such a large amount of rain water that
it practically has no hardness. During these periods
the chemical treatment is eliminated and the water is
simply passed through the filter.
In the words of the chief engineer, E. H. Clark, the
feed water is now ideal. The condensate from the con-
densers is returned to the heater and the 15 to 20 per
cent, of makeup is the treated water. When the puri-
fier was installed the boilers were thoroughly cleaned
and the scale removed. Since then they have been
opened up every 30 to 4-5 days, and washed out. During
Xo. Equipment
4 Boilers
4 Stokers
1 Stack
1 Coal conveyor
1 Coal crusher.
1 Water soli, hit
1 Heater
2 Pumps
2 Pumps
2 Condensers, . . .
2 Pumps
2 Pumps
2 Pumps
.5 Spray nozzles.
1 Exciter.
1 Exciter.
PRINCIPAL EQUIPMENT OF SOUTHERN ILLINOIS RAILWAY A POWER CO.'S PLANT
Kind Size Use Operating Conditions Maker
Vertical water-
tube. . 400 hp Genei ate steam 160-lb. pressure, natural draft, stokers Wickes Boiler Co.
Top-feed Projected area,
fit sq.ft Serve boilers Draft over fire 0 25 to 0.35 in Murphy Iron Works
Concrete 155 ft. high, S ft.
diam Natural draft for boilers GeneralConcreteConstructionCo.
Scretv-and-bucket 20 tons per hr. . . . Transfer coal from car
to bunker Driven by 20-hp. induction motor A. Lucas & Sons
Crush lump coal. ..... Driven by 20-hp. induction motor A. Lucas & Sons
Soften boiler feed Wm. Graver Tank Works
Heat boiler feed watei . . Exhaust from auxiliaries Piatt Iron Works Co.
Feed boilers 160 lb. steam . Plat t Iron Works Co.
Water from reservoir to
tank 160 lb. steam Piatt Iron Works Co.
Locomotive 9Jx9JxlO-in Blowing flues, etc. ion Hi t.-m:, Westinghouse Air Brake (
2-stage, horizon- Orive at 3600 r.p.m., three-phase, 60-cycle,
tal, Curtis 1000-kw Main units 2300-volt generators General Electric Co.
Surface. 3600 sq.fl Serve main units Piatt Iron Works Co.
Dry-vacuum ,. lOxlSxlS-in . . Serve condensers. 160 lb. steam Piatt Tron Works Co.
Centrifugal 3000 ^al. per miti. Condenser circ. water. Driven 1250 r.p.m. by 50-hp. ind. motors Plat I Iron Works Co.
20 tons per hr. . .
Cold process . . 2000 eal. per hr..
Open 1000 hp
Duplex 10x6xl2-in
Duplex 6x7xl0-in
Duple
7x5x6-in Condensate pumps 160-lb. steam Piatt Iron Works Co.
nozzle Cool condenser water Spray Engineering Co.
35-kw Excitation for main
units 125-voIt, 3601) rp.m General Electric Co.
50-kw Excitation for main 125-volt, 1200 r.p.m., motor 75 hp., ind., 2300-
units volt General Electric Co.
2300-volt synchronous motor, 430 hp., 720
Railway 300-kw Railway service. . . . r.p.m., 1200- volt, cons tan i -current generator. General Electric Co.
Turbinc-driv
Motor-drivei
modating the chemical charge to these variations in
order to maintain a uniformly treated water. The chart,
Pig. 8, shows the amount of hardening ingredients re-
maining in the treated water during a three-weeks' period
in the month of July. The average hardness during the
period is practically three grains. The following an-
alyses, made at different periods, show the large varia-
tion in the quality of the river water.
Mar. 1. l''l I June 26, 191 4
Grains per Gal. ( trains per I lal.
Calcium carbonate 1.35 9.00
Calcium sulphate 1.97
Magnesium carbonate ... ...
Magnesium sulphate 3.2a 9.3s
Silica 5.30
Iron and aluminum oxides 0.75 ...
Suspended matter Undetermined 1.21
Total Incrusting solids 12.66 19.59
Sodium sulphate 0.S7
Sodium chloride 1.60 14.63
Total nonincrustins; soli. Is.. 2.47 14.63
Total solids 15.13 34.22
The following is an average analysis of water deliv-
ered during the past summer:
INCRUSTING SOLIDS
Grains per Gal.
Calcium carbonate 2.1J
Magnesium hydrate 1.40
Silica 0.06
Total incrusting solids 3.56
the nine, months the purifier has been in service, there
has been practically no scale ami no evidence of corro-
sion.
The W. II. Schott Co., of Chicago, designed the plant
and had charge of its erection, but the engineering is
now under the direction of C. J. Davidson, of the firm
of Woodmansee & Davidson, consulting engineers, of the
same city. Under their direction the water softener and
spraying nozzles were installed. They report a bright
outlook for the plant. As previously stated, Marion has
just been added to the li<t of towns taking service, and
other prospects are in view which will increase the load
ami better tl perating efficiency of the plant.
v
The Advantaitwi of Small, High-Velocity Steam Piping; are:
Lower first cost for pipe, valves and covering, etc., less erect-
ing and maintenance cost: less weight; less radiation loss;
less chance for water to accumulate and less difficulty with
valves of smaller size.
:*
To Increase Industrial Prosperity this country needs to
export finished rather than crude products and to import raw
materials rather than manufactures. Betterment of industrial
condit'ons can come best through expansion of manufacturing.
The increase of the element of labor in the product exported
will mean that we are not bartering away our heritage of
natural resources, but rather that we are using these resources
a3 a basis simply for the expenditure of labor, which renews
itself — George Otis Smith, Director, United States Geological
Survey.
702
pow e i;
Vol. II. No. 21
imiteFfioiF Wirimi^ for ILiuJhtinnid auni<
ower ^ervuc(
P.Y A. I,. Cook
SYNOPSIS— The previous articles of the series
covered //" layout and wiring calculations for
lighting systems; the present and succeeding in-
stallments cover power circuits, including loca-
tion <</ motors mill control devices, determination
of Intnl. voltage drop and wiring calculations.
It is beyond the scope of this article to discuss the
types of motors best suited for various industrial condi-
tions, but the location of motors and (be choice of control
dc\iccs will be considered before taking up the wiring.
The location of the motor will be, to a large extent, lived
by that of the driven machine. If there is a choice, how-
ever, it should be placed where it can be easily reached
lor inspection, and also where it will be protected, as far
as I he surroundings permit, from moisture, dust and
accumulations of dirt. It is desirable to avoid where pos-
sible the use of entirely inclosed motors because of their
greater cost. Control devices also should be selected with
regard to where they are to be used ami the class of labor
which is to operate them. The] should he placed in the
position most convenient for the operation of the motor
ami should always include a switch located in sight of the
motor, by means of which all wires running to the motor
or control device can be disconnected from the supply.
This is necessary to facilitate repairs ami is a safeguard
against operation by unauthorized persons. If the motors
are supplied from near-by panel-boards, these switches can
be placed on the panels.
The systems of distribution for power include two-wire
alternating or direct current, and three-phase or two-
phase alternating current. The standard voltages for
direct-current motor service have already been specified.
A voltage of 115 should be used only where the motors arc
small and the feeders short. The best voltage for usual
conditions is 230, as this gives reasonably small conduc-
tors, even for long runs. One advantage of this voltage
is that tin' supply can easily be made three-wire for light-
ing and two-wire (230 volts) for the motors. A voltage
of ."..'ill should he used only where the feeders are very long
and the motors la rue. The panel-boards and control de-
vices will lie much larger than for the other voltages, and
the cost of maintenance of the system under usual factory
conditions will be greater. There is also greater danger
of injury to the workmen than with lower voltages. This
high voltage is not at all adapted for power supply in an
office building and is seldom used for that purpose.
A two-wire alternating-current system (single-phase
system) is adapted only to supplying motors up to ah, mi
15 hp. With alternating current, either the three-phase
or the two-phase system is ordinarily used. The former
is best adapted for the usual power supply in factories,
the two-phase system being used principally by central
stations, where the lighting and motor loads are carried
on the same distributing system; in which case the two-
phase system is easier to balance than the three-phase. It
is possible, however, to operate either system satisfac-
torily in this way. For an isolated plant, however, the
three-phase system is preferable; the lighting load being
taken from one or more phases, depending on its relative
importance compared with the power load. The choice
between 25 and 60 cycles is influenced by the fact that the
latter is better for lighting and the cost of the motors is I
somewhat less. There is also the advantage of a greater
number of available speeds in 60-cycle motors for the
range usually n led.
Choice of Motoks
Alternating-current motors have definite speeds. Bxed
by the frequency and depending upon the number of poles,
whereas direct-current motors have greater flexibility in
this respect. The available no-load speeds for alternating-
current motors for the usual range are given in Table ID.
The highest speed is for the two-pole motor, and the speed
can lie made as low as required by providing a suitable
number of poles. It will be seen by reference to this
table that for 25 cycles motors can be built for only
three speeds between 500 r.p.m. and the maximum;
whereas for tin cycles there are seven speeds. All of these
speeds cannot be obtained from the same motor, which, on
the contrary, must be built for a particular speed, and
only by special design can it be run at more than one of
these speeds; even then the number of available speeds is
limited to two.
The alternating-current system is generally better
suited for factory power supply than the direct-current,
because of the greater reliability and ruggedness of the
alternating-current motor. The standard alternating
voltages available for general use with either three-phase
TABLE 10
—AVAILABLE SPEEDS FOR
CURRENT MOTORS
ALTERNATING
Number of Poles
60
-No-Load
Cycles
Spee
1. R
. 25
p.m. ,,
Cycles
2
4
6
S
10
12
14
3600
1800
1200
900
720
600
514
1500
750
500
375
300
250
214
or two-phase systems are 110, 220, 1 in or 550 volts, and
for large motors -.'•.'no volts. The ease with which the
voltage may be changed to suit conditions allows great
flexibility in the choice of a voltage for the motors. Either
220 or I In volts is commonly used, the lower voltage being
preferable for moderate-sized installations, particularly
where the supervision may be in relatively unskilled
hands. The danger of workmen receiving fatal shocks
is greater with alternating than with direct current, and
440 or 550 volts presents a real hazard in this respect ;
shock from 220 volts is seldom fatal. In establishments
of considerable size, particularly with large motors, the
great saving in feeder size with 440 or 550 volts results in
their frequent use.
More complete protection is permissible with alternat-
ing than with direct current, so that with careful planning
of the control devices and first-class wiring, these higher-
voltage systems can he made fairly safe. Sometimes 1100
or 2200 \olts are used for alternating-current motor
drive, hut as such a high voltage is adapted only for large
motors and requires special methods of installation of the
May 35, 1915
P 0 W B 17
703
wiring and control system to make it safe, these will not
be considered in this article.
The common types of direct-current motors are the
ehunl motor, which is practically constant-speed, and the
series motor, which gives variable speed. While the
former is called a constant-speed machine, since the -peed
is practically constant from no load to full load, the speed
can be adjusted through a wide range by changing the
resistance in either the field or the armature circuit, the
former method hem- preferable. The shunt motor is
adapted for any constant-speed service, such as driving
machine tools, woodworking machinery, fans, and the
like, while the series motor is besi adapted Eor driving
eranes, hoists and similar devices. For some purposes a
compound motor, which combines the characteristics of
the series and shunt, is best; the principal applications
of this type hem- found in the driving of elevators,
punch-presses, planers, etc.
The usual type of alternating-current motor is the in-
duction motor, which may he of the squirrel-cage or the
wound-rotor type. The former is the mosl rugged and the
simplest kind of motor made, and is cheaper and more
satisfactory for general use than the wound-rotor type.
A disadvantage is that it cannot start under heavy load
without taking a large current from the line, but where
the starting load i- less than full load and a constant
speed is required, the squirrel-cage motor should be used.
If the driven machine requires a large starting torque, as
for example, a compressor starting under full pressure, or
if the speed must be adjusted, then the wound-rotor type
must be used. Sometimes it is desirable to use this type
of motor ''or constant-speed service when the size of the
motor is large compared with the capacity of the gener-
ator supplying the load, because of the great drop in volt-
age caused by starting a large motor.
The full-load current required by a motor is always
marked on the nameplate, hut it is frequently necessary
to lay out the wiring before the motors have been received.
To assist in estimating the load. Tables 11, 12 and 13
have been prepared. The full-load currents given arc for
TABLE 11 — CURRENT AND SIZE OF WIRE FOR DIRECT-
CURRENT MOTORS
i t, Amperes,
pg Full Load
£; US 23(1 r.r.o
X o, v- v- v-
. Bl
— Rubber Insulat
LIE V 230 V.
ze oi w
ion >
550 V.
—Other 1
115 V.
nsulation — ,
S50
230 V. V.
0.5 5 2.5 1.1
1 8.8 4.4 1.8
2 16 S 3.4
3 24 12 5
11
14
10
14
14
12
12
14
14
14
14
14
14
14
b
14 14
14 14
14 14
14 14
5 40 20 8.4
7 5 58 29 12.1
in 76 38 15 9
IS 112 56 23.4
20 14G 73 30.5
3
1
00
0000
S
6
5
3
1
14
12
10
8
6
6
3
1
0
10 14
X 14
6 12
If
3 8
25 182 91 38.1
30 216 ins 45.2
35 2S2 126 52 6
250,000
s.-.n.iiiio
100.
0
00
000
6
4
4
000
000
0000
2 S
1 6
0 6
40 2SS 141 60 2
50 356 17s 74.4
60 42S 21) 89 5
75 532 266 1 1 1
Son,
600,000
800,000
1,100,1
0000
250,000
350,000
150,
3
1
0
00
300,000
:;."iO,
r.oo.
i;oo,ooo
0 E
000 3
000 2
250,000 1
100 710 355 148
1,700,000
600,000
0000
900,000
350,000 0
125 886 443 1SS
850,000
two
1,100,0101
850,000
300,000
1,200,000
500,000 00
150 1076 535 224
1.100,000
400,
l.MI",
700,000 0000
•Allows at least 25 per cent.
Dverloai
.
direct-current motors and for the usual type of alternat-
ing-current induction motors. For the direct-current
motors, the "National Electric Code" requires that the
size of wires shall he sufficient to carry at least a 25-per
cent, overload and the usual motor for continuous service
is designed to carry a 25-per cent, overload for two hours.
The sizes of wire Bpei Hied in Table 11 are such that the
motor can carry from 25 to 30 per cent, overload without
the <urrent rating of the wire in accordance
with the "i odr" rules. To find the current and size of
wire for a motor no! given in the table, find the ampi r<
per horsepower for the nexi smallest motor, and then mul-
tiply by the horsepower of the given motor. For example,
to find' the current Eot a 65 hp. 550-volt direct-currenl
. 89.5
motor, we tind. that the current per horsepower is — — =
1.49 amp. The full-load current for a 65-hp. motor is then
1 i:i x 65 = 97 amp. Allowing 25 per cent, overload,
the current would be 121 amp., and if rubber-covered wire
is used the size would be No. 0.
TABLE 12— CURRENT AND SIZE OF WIRE FOR THREE-
PHASE INDUCTION MOTORS, SQUIRREL-CAGE TYl'E
Size ot Wire,
, Rubber or Other Insulation *
110 V. 220 V. 440 V. 550 V.
Am
leres,
Full
L,oad
Horse
- llo
220
440
550
power
V.
V.
V.
V.
•0.5
3.6
1.8
0.9
0.7
•1.0
6.4
3.2
L.6
1.3
•2.0
11.6
5.8
2.9
2 ::
•3.0
16.4
8.2
4.1
3.3
5.0 26.S 13.4 6.7 5.4 5
7.5 39.2 19.6 9.8 7.9 21
10.0 53.2 26.6 13.3 lor 0
15.0 77.0 38 6 19.3 15 5 00
20.0 109.0 54.6 27.3 21.8 0000
2.". 0 12.-.. ii 62.6 31.3 2S.1 300,000
3.",. ii . . . 85.6 42.8 34.3
50.0 . . . 122.0 61.0 4S.6
0
200.0
179.0 89.0 72.0
237.0 lis. o 95.0
13 0 I 76 0 141.0
451.0 226.0 M.n
450,000 000 0
600,000 250,000 000
1,100.000 400.000 300,000
(2) 600,000 600,000 450,000
2500... 560.0 280.0 224.0 (2)800,000 S00. 000 600,000
:, ... 670.0 335.0 268. 0 (2)1,000,000 1,000,000 800,000
♦These motors are thrown directly on the line; all others
are provided with auto-starters set to give a starting torque
equal to full-load running torque.
The allowance mentioned for overload would he suffi-
cient in the majority of cases; but if the motor is subject
to heavy momentary overloads, as for example in the case
of a planer drive, a larger overload should be allowed.
There is a disadvantage in ('using the motor too high, as
it is then not protected against continuous overload which
might burn out the motor. For alternating-current
motors also, the ••('ode" requires that the wire shall be
sufficient to allow at least 25 per cent, overload. Tables
12 and 13 give data for three-phase and two-phase in-
duction motor.-, the full-load current value- being for
modern, high-efficiency motors. These values apply more
particularly to the squirrel-cage type; for wound-rotor
type of motor the full-load currents would be slightly
greater. Squirrel-cage induction motors take very large
currents from the line when starting, averaging about 2.9
times the full-load value with a torque equal to full-load
running torque. To obtain this starting torque, about 85
per cent, of full-load voltage is applied to the motor.
Usually, the load driven by a squirrel-cage motor is such
that a voltage of 65 per cent, can be used, and then the
starting current will 1 nl\ about 2.2 times full-load cur-
rent. A wound-rotor type of induction motor, starting
under full load, takes aboul 25 per rent, inure than the
full-load current when running.
Because of the heavy starting current required for
squirrel-cage induction motors, the rules allow the leads
to he selected in accordance with column P> of Table 3
(see page 642, May 11 issue) even when rubber-covered
wire is used. The sizes specified in Tables 12 and 13
are chosen on this basis. For wires with other insulation
the same allowance is not made; that is. according to the
"Code,'- the wire must he chosen in accordance with col-
704
POWER
Vol. 41, No. 21
umn P> also. However, the inspectors will often allow
induction-motor wires when exposed to lie fused somewhat
higher than the values given in column B. It is appar-
ent that the wires will be adequately protected from in-
jury when fused in accordance with these rules, but the
motor will not be properly protected against continuous
overloads, which would nor cause the fuses to blow, but
still would be larger than the motor could safely stand for
any length of time. It is customary, therefore, to pro-
vide ''running fuses" which are not in circuit during
starting. The ordinary induction motor is rated to stand
a 25-pei 1 1 nt. overload fur two hours, but ran carry greater
loads for short periods. Therefore, the running fuses
should have a rating about 50 per cent, greater than the
full-load current of the motors.
The rules given for determining the proper size of wire
and the fusing of motors apply to motors intended for
continuous service, which are designed to carry their rated
load continuously or to carry a 25-per cent, overload for
two hours. There are certain other kinds of service, sui h
as craues and elevators, where the load is intermittent and
the motor is required to carry heavy momentary loads. The
sizes of fuses and wire< for tin- service are chosen some-
what differently, the motors being rated at the load which
they will carry for 30 min. without exceeding a safe tem-
perature. Direct-current motors for intermittent service
will, however, carry a 50-per cent, overload for short pe-
riods without injury and will carry a 100-per cent, over-
load momentarily without injurious sparking. Alter-
nating-current motors are also rated on a 30-min. basis,
and since they have no commutator, will stand for short
periods large overloads, amounting to "2 or 'i1* times full-
load current. Direct-current motors for intermittent ser-
vice should he provided with fuses allowing at least 50
per cent, overload, and the branch circuits for the mo-
tors must therefore be sufficient to carry this current. Ii
rubber-insulated wire is used, column A of Table T should
be used; for other insulations column B should be em-
ployed. In the case of alternating-current motors, the
"Code" specifies definitely the current rating for the
branch circuits; the values given are as follows:
Percentage of
Current Rating
Service of Motor
Operating valves, raising or lowering rolls, tool
heads, etc 200
Hoists, rolls, ore- and coal-handling machines.. ISO
Freight elevators, shop cranes 160
Passenger elevators 140
Rolling tables, pumps 120
This applies to varying-speed alternating-current mo-
tor-: that i>. where the speed changes with varying loads,
as in the series direct-current motor, the current referred
to being rated for the 30-min. load rating, as previously
mentioned. The size of wire must be selected by using
either column A or B of Table 7, depending upon the in-
sulation.
In general each feeder will supply a number of motors
and in order to calculate its size the probable maximum
current to be carried by the feeder must be determined.
For usual factory conditions this would be considerably
less than the sum of the full-load currents of the motors
connected to the feeder. It would seldom occur that all
the motors would be carrying full load at the same time.
Consequently, a load factor must be assumed, the term
load factor meaning the ratio of the maximum to the
total connected load. This may vary from 40 to 80 per
cent., depending upon the nature of the work and the num-
ber and size of motors on the feeder. "Where there is a
large number of small motors, this factor would be less
than where there are a few large motors on the system.
For ordinary factory conditions, in the absence of better
information, the load factor for the feeders may lie taken
as ! 5 per cent, of the rated load of the motors. With al-
ternating current the size of wire should be checked by?.
assuming the largest motor starting and all the others
running, allowing 7"> per cent, of the full-load current for
these motor,-.
TABLE 13 — CURRENT AND SIZE OF WIRE FOR TWO-1
PHASE INDUCTION MOTORS, SQUIRREL-CAGE TYPE )
Amperes, Full Loadf
Horse-
11"
220
440
power
V
V.
V.
•0.5
:: '•
1.6
•1.0
6
2 i
1.4
•2.0
10.0
5.0
2 ",
•3.0
14.4
" -'
3.6
5.0
11.6
5 8
7 5
34.0
17.0
8.5
10.0
46.0
11.5
15.0
66.8
33.4
IK. 7
Size of Wire.
— Rubber or (Jther Insulation-
llo V. 220 V. 440 V 550 \
150.0
200.0
94 4 47.2 23.6 IS. 9 000
: 1' 27.1 21.7 0000
74.2 37.1 29.7
105.0 52.fi 42.1
155.0 77.3 61.9
205.0 103.0 82.0
30fi.o 153.0 123.0
390.0 195.0 156.0
0000 0
350,000 00
500.000 0000 000
900,000 350,000 300,000
(2) 500,000 500.000 400.000
•These motors are thrown directly on the line; all others
are provided with auto-starters set to give a starting torque
equal to full-load running torque.
tValues of current are for a two-phase, four-wire system;
if three wires are used, current in common wire would be 1.42
times value given.
The allowable voltage drop for power circuits can be
greater than for lighting circuits, but should not be too
large, particularly with induction motors, as they do not
operate satisfactorily at voltages greatly below normal.
A total of 5 per cent. drop, figured from the motor to the
service point or the power-house switchboard, is satisfac-
tory and does not require excessive feeder sizes. This
voltage drop should be divided about as follows: Indi-
vidual motor circuits. 1.75 per cent.: feeders and subfeed-
eTS, 3.25 per cent. : total, 5 per cent.
Direct-current motor circuits can he calculated by
means of the wiring chart already described (sei
.May 18 issue). Alternating-current circuits cannot he
calculated as easily. This j> because of the power factor of
the motor circuits, which is generally about 0.80. The
effect of this power factor is to make the drop greater than
if it were 1.00. as in the case of lighting loads. The
extent to which the drop is thus increased depends upon
the spacing between wires, the effect being least when
the wires are in one conduit and increasing very rapidly
when they are separated and run on insulators. When all
the wires of a circuit are run in the same conduit the drop
is practically the same as for direct current, for wires
reater than No. 0 for 60-cycle circuits and not larger
than 300.000 circ.mils for 25 cycles. The wiring chart
which was used in lighting calculations can therefore
be used for such cases. For larger wires run in con-
duit and for all wire- separated a considerable dis-
tance, as in exposed work, the drop must be calculated
by other means. The simplest method is to determine
tin' drop in the usual manner, by means of the direct-
current chart already explained, and then to determine the
additional drop which would be caused by the inductive
effect. A method for doing this has been developed by
May
1915
POWER
705
C. F. S.ott and C. P. Fowler and was published in the
April, 1907, issue of The Electric Journal.
The drop due to inductance depends upon the ratio of
reactance to resistance and also upon the power factor.
The reactance depends upon the frequency and upon the
spacing between wires. We require, then, a table giving
this ratio for the particular spacing of the wires and the
proper frequency and also a table giving the drop factor
corresponding to various values of this ratio. Tables 14
and 15 give these quantities.
An example in the use of these tables will assist in un-
derstanding the method employed. Assume a No. 00 wire
carrying a single-phase alternating current of 50 amp. a
distance of 150 ft. at a frequency of 60 cycles. The drop,
if direct current were used, is found by the chart (page
667, .May 18 issue) to be 1.2 volts. Assuming the wires
are all in the same conduit, it will be seen from Table 14
that the ratio of reactance to resistance is 0.54. Assume
that the load consists of incandescent lamps, so that the
TABLE 14— RATIO OF REACTANCE TO RESISTANCE
-Ratios for Distance bet'
2V> In. 4 In. 5 In.
60 Cycles
^een "Wires of
6 In. S In. 12 In.
10
s
6
5
0.05
0.08
0.12
0.14
0.09
0.13
0.21
0.25
0.10
0.15
0.23
0.2S
0.11
0.16
0.24
0.30
0.11
0.17
0.26
0.31
0.12
0.1S
0.27
0.33
0.13
0.19
0.29
0.36
4
3
2
1
0.15
0.22
0.26
0.32
0.30
0.37
0.45
0.54
0.34
0.42
0.52
0.62
0.36
0.45
0.55
0.67
0.38
0.47
0.57
0.70
0.41
0.50
0.62
0.75
0.44
0.54
0.67
0.82
0
00
000
0000
0.3S
0.54
0.64
0.76
0.66
0.80
0.97
1.17
0.77
0.93
1.14
1.38
0.82
0.99
1.21
1.48
0.S6
1.04
1.28
1.56
0.92
1.13
1.38
1.70
1.01
1.25
1.53
1.87
300,000
400,000
500,000
600,000
1.01
1.49
1.75
1.85
1.54
1.93
2.30
2.52
1.84
2.33
2.80
3.10
1.98
2.52
3.03
3.40
2.10
2.67
3.22
3.63
2.28
2.92
3.54
2.52
3.26
700,000
800,000
900,000
1,000,000
2.06
2.49
2.69
2.89
2.S4
3.12
3.39
3.66
3.54
10
8
6
5
0.03
0.05
0.08
0.09
40 Cycles
0.06 0.07 0.07
0.09 0.10 0.11
0.14 0.15 0.16
0.17 0.19 0.20
0.07
0.11
0.17
0.21
O.OS
0.12
0.18
0.22
0.09
0.13
0.19
0.24
4
3
2
1
0.10
0.15
0.17
0.21
0.20
0.25
0.30
0.36
0.23
0.28
0.35
0.41
0.24
0.30
0.37
0.45
0.25
0.31
0.38
0.47
0.27
0.33
0.41
0.50
0.29
0.36
0.45
0.55
0
00
000
0000
0.25
0.36
0.43
0.51
0.44
0.53
0.65
0.78
0.51
0.62
0.76
0.92
0.55
0.66
0.81
0.99
0.57
0.69
0.85
1.04
0.61
0.75
0.92
1.13
0.67
0 83
1 02
1.25
300,000
400,000
:
600,000
0.67
1.00
1.17
1.23
1.02
1.28
1.53
1.68
1.22
1.55
1.87
2.07
1.32
1.68
2.02
2.27
1.40
1.77
2.14
2.42
1.52
1.95
2.36
2.67
1.67
2.17
2.43
3.02
700,000
800,000
900,000
1,000,000
1.38
1.67
1.80
1.93
1.90
2. OS
2:45
2.36
2.63
2.87
3.08
2.58
2.87
3.15
3.40
2.76
3. OS
3.3S
3.67
3.05
3.40
3.45
10
8
6
5
0.02
0.03
0.05
0.06
0.04 "
0.05
0.09
0.10
5 Cycl
0.04
0.06
0.10
0.12
is
0.05
0.07
0.10
0.13
0.05
0.07
0.11
0.13
0.05
O.OS
0.11
0.14
0.05
0.08
0.12
0.15
4
3
i
0.06
0.09
0.11
0.14
0.12
0.15
0.19
0.23
0.14
0.18
0.22
0.26
0.15
0.19
0.23
0.28
0.16
0.20
0.24
0.29
0.17
0.21
0.26
0.31
0.1S
0.23
0.28
0.34
0
00
000
0000
0.16
0.23
0.27
0.32
0.2S
0 33
0.40
0.49
0.32
0.39
0.48
0.5S
0.34
0.41
0.51
0.62
0.36
0.43
0.53
0.65
0.3S
0.47
0.58
0.71
0.42
0.52
0.64
0.78
300,000
400,000
500,000
iiiin,
0.42
0.62
0.73
0.77
0.64
0.81
0.96
1.05
0.77
0.97
1.17
1.29
0.S3
1.05
1.26
1.42
0.88
1.11
1.34
1.51
0.95
1.24
1.48
1.67
1.05
1.36
1.65
1.88
700,000
Villi, (Hill
900,000
1,000.000
0.86
1.06
1.12
1.20
1.18
1.30
1.42
1.53
1.47
1.64
1.79
1.92
1.61
1.79
1.96
2.12
1.72
1.92
2.11
2.29
1.91
2.12
2.34
2.54
2.15
2.31
2.49
power factor may be taken as 1.0. Then the drop factor
is found from Table 15 to be 1.004. That is, the direct-
current drop of 1.2 volts must be multiplied by 1.004.
which gives 1.205 volts. Hence the alternating-current
drop under these conditions is practically the same as the
direct-current drop. If the wires are 6 in. apart the ratio
would become 1.04, the drop factor would be 1.044 and
the alternating-current drop would be 1.25 volts. If the
power factor is 0.8, the drop factor would be 1.42 and the
alternating-current drop would he 1.70 volts. It will
TABLE 15— DROP FACTORS*
Ratio of
Reactance „ ,
to , Drop Factors for Power Factors of ,
Resistance 1.00 0.95 0.90 0.85 0.80 0.70 0.60 0.40
0 1 1 00 1 00 1.00 0.94 0.88 0.80 0.70 0.60
02 100 1.01 1.01 0.98 0.92 0.86 0.82 0.67
0^ 1.00 1.05 1.05 1.02 0.99 0.93 0.89 0.74
0.4 1.00 1.08 1.10 1.08 1.04 1.00 0.93 0.82
0 5 1.00 1.11 1.14 1.13 1.10 1.07 1.01 0.92
06 101 115 1.18 1.19 1.15 1.14 1.09 1.01
0 7 102 1.18 1.23 1.24 1.21 1.20 1.17 1.11
0.8 1.02 1.21 1.28 1.29 1.2S 1.27 1.24 1.20
0.9 1.03 1.25 1.33 1.34 1.34 1.35 1.32 1.29
1.0 1.04 1.28 1.37 1.39 1.40. 1.41 1.39 1.38
1.1 1.05 1.32 1.41 1.44 1.45 1.48 1.47 1.46
1.2 1.06 1.35 1.46 1.50 1.51 1.55 1.54 1.55
1 3 1.07 1.39 1.51 1.55 1.57 1.62 1.63 1.64
14 108 1.43 1.55 1.61 1.64 1.70 1.71 1.72
15 110 1.47 1.60 1.67 1.70 1.77 1.80 1.81
1.6 L10 1.51 1.65 1.74 1.77 1.85 1.87 1.90
17 113 1.55 1.70 1.79 1.84 1.92 1.95 1.99
18 115 1.59 1.76 1.85 1.91 1.99 2.04 2.08
19 117 163 1.82 1.91 1.98 2.06 2.11 2.16
2!o LIS lies 1.87 1.96 2.04 2.14 2.19 2.25
2.1 1.20 1.72 1.92 2.03 2.10 2.21 2.28 2.35
2 2 1 22 1.77 1.98 2.09 2.17 2.29 2.37 2.45
23 123 1.82 2.03 2.15 2.23 2.37 2.45 2.53
2.4 1.25 1.87 2.09 2.22 2.30 2.44 2.53 2.62
2 5 127 1.91 2.14 2.28 2.37 2.52 2.60 2.71
26 1 30 1 95 2.20 2.34 2.44 2.60 2.67 2.80
27 132 199 2.26 2.41 2.51 2.68 2.74 2.9S
2!s L35 2^5 2!32 2.47 2.57 2.76 2.82 3.07
2 9 137 2.10 2.39 2.54 2.64 2.83 2.91 3.15
30 1 40 2 15 2.45 2.60 2.72 2.90 3.00 3.23
31 l'42 2 20 2.51 2.66 2.80 2.97 3.10 3.31
3.2 1^5 2.26 2.57 2.73 2.87 3.05 3.20 3.39
3 3 1 4S 2.31 2.63 2.S0 2.93 3.12 3.30 3.47
34 151 2.36 2.69 2.87 3.00 3.20 3.39 3.56
35 1.53 2.42 2.74 2.94 3.08 3.27 3.4S 3.65
36 157 2.47 2.80 3.00 3.15 3.35 3.56 3.75
3:7 L60 2.U 2.86 3.07 3.23 3.43 3.65 3.85
•Reprinted by permission from "The Electric Journal," Vol.
IV. p. 299.
be seen that for a power factor of 1.0 the alternating-
current drop is practically equal to the direct-current drop
lor ratios up to 0.7, being only 1 per cent, higher for
0.6. For lower power factors, however, the alternating-
current drop is, in general, different from, and may lie
less than, that for direct current. Therefore, it is neces-
sary to estimate this in each case. Table 16 gives the
usual values of the power factor for various kinds of loads.
The values for induction motors assume that all the
motors on a feeder would not be carrying full load at the
TABLE 16
Power Factor
Incandescent lamps of all kinds 100
Arc lamps, including flaming arcs.... J-»J
Induction motors (running) up to 15 hp u.bu
Above 15 hp u!>0
same time. The power factor of induction motors when
carrying full load is in general greater than the values
herewith given.
The values refer to the sizes of the individual motors
on the feeder. That is, if a feeder carried one 15- and
four 10-hp. motors the total connected motor load would
be 55 hp., but the power factor on the feeder should be
taken as 0.80. By examining Tables 14 and 15 it will be
noted that the alternating-current drop increases very
rapidly as the size of wire increases. As a rule, wires
larger" than 300.000 circ.mils should be avoided, except
TOG
TOWER
Vol. 41, No. 21
where the wires are in conduit, when a size of 500,000
circ.mils or larger may be used. If larger wires are re-
quired to carry the load two or more can be employed in
parallel. For example, find the drop on a 500,000-circ-
mil feeder carrying 300 amp. a distance of 500 ft. The
direct-current drop is 6.4 volts. [f the frequency is GO
cycles, the power factor 0.8 and the spacing (I in., the
drop factor is 2.88 and the alternating-current drop is
18.4 volts. Xo. OODO cable is about one-half the size of
500,000-eirc.mil cable; therefore, calculate the drop, us-
ing two No. 0000 (ahlcs instead of a single wire. The
current per cable would he 150 amp., the direct-current
drop would be 7.6 volts and the drop factor 1.74. Hence,
the alternating-current drop would be only 13.2 volts,
which is considerably less than for the single cable. Fig-
uring the size of wire to give the same voltage drop as
before (18.4 volts), we find that a No. 00 cable gives
an alternating-current drop of IT. 2 volts. That is, two
No. 00 cables having a total cross-section of 2GG,200
circmils will carry a total load of 300 amp. with less drop
than for a single 500, 000-circ.mil cable with a great saving
ill copper. This saving often exceeds the additional cost
of running two circuits instead of one, so this point should
always be kept in mind when laying out alternating-
current circuits. In this connection, it should be stated
that wires which are run in multiple, as in the above case,
should always be of the same size. For example, if a 500,-
000- and a 300, 000-circ.mil cable were employed to take
the place of one of 800,000 circmils the smaller wire would
take more than its share of the load, and in some cases,
might be overheated. This method can also be used for
the calculation of three-phase and two-phase circuits by
making certain modifications which will be explained
later.
Cltiaftclhi SlbafUer
An interesting clutch-shifting device for use with the
Hilliard clutch and manufactured by the Ililliard Clutch
& Machinery Co., Elmira, X. Y., is'illustrated in Fig. 2.
While to date this mechanism has been used exclu-
sively in connection with Ililliard clutches, its applica-
tion is not confined to this particular make, but it is
equally adaptable to any clutch which has a slidm-
Fig. 1. SiuiTKi: on Clutch between Pump and Motot;
member for engaging and in which can be cut the nec-
essary groove to accommodate the clutch-shifter yoke.
This device is made either in solid or split form, and
the operating mechanism is held in a set position on the
shaft by two safety collars; the thrust for engaging the
clutch is obtained by means of the rack and pinion. For
operating the pinion, several devices may be employed,
but preferably a handwheel, which can be attached by a
key or a setscrew to the stub pinion shaft or to an ex-
tension shaft coupled to the short shaft provided. The
device is convenient under certain conditions, say when
it is desired to operate a clutch from the opposite side
of a brick wall. In one case a 12-ft. extension shaft
was attached to the short pinion shaft by a coupling
common pillow blocks being used for a bearing in the
wall. On the end of the shaft an ordinary handwheel
Fig. 2. Rack-and-Pinion Clutch Shifter
was attached, and although separated from the shaft by
a brick wall, the operator had perfect control of the
clutch.
There are many places where this device would prove
useful. It is manufactured in three sizes. No. 1 size
will accommodate a 2-iu., No. 2 a 3-in. and No. 3 a
htVin. shaft. The yoke, suspended from the shaft, is
equipped with grease cups which provide ample lubrica-
tion, and the device is efficient.
Pig. 1 illustrates an Sy2-in. clutch of '.l/o-hp. capacity
and shifter on the shaft of a 15-hp. motor that is used
for driving two pumps running at 1200 r.p.m. One
pump is coupled to the motor shaft direct, the other by
means of the clutch. The convenience of the arrange-
ment is apparent.
The Area of Chimneys should be proportioned to the quan-
tity and quality of the fuel consumed per hour. Isherwood
determined by experiments that the stack area should be
from one-sixth to one-eighth the area of the grate, modified
by the velocity of the gas. This in turn is influenced by the
temperature of the gas and the height of the stack.
Safety-Valve Capacity— Below is given the number of
square feet of heating surface served by a single 4-in pop
safety valve at 100 lb. gage pressure, under the requirements
of the various rules noted. The assumption is made that the
ratio between grate surface and heating surface is 1 to 40
and in such rules as require the rate of combustion to be
assumed, it has been taken at such rate as would cause
the evaporation of 1C0 lb. of water per square foot of grate
surface per hour.
Sq.Ft.
U. S. Government rule ( a = 0 2074 "fMght of water fvaporated per hr.\
(V absolute pressure )
n - 0.2130 WP'ght "f "'•"er ""''"Porated pei hr.\
absolute pressure )""
Utoo rule (same as Mass.) ... ' ,7nn
Detroit rule (same as Mass.) . {,2j
Memphis rule (same ;is Mass.) 1 TOO
Board of Trade rule (- — \
XT , , Vabsolute pressure/" ' .iosu
.Newfoundland (same as Board of Trade rule) |UO
Alberta (same as Board of Trade rule) i?,Tn
British Columbia (same as Board of Trade rule) 1 5411
-wan (same as Board of Trade rule) ' i '-, .,,
Cntano (same as Botrd -J Trade lufe) j^g
Philadelphia ( ?L5 S "
, Vgage pressure +8.62^ li9a
Indiana (0.33 sq.in. ptr sq.ft. grate) isl0
Average ...
» 1 &S- ?oi1' r Co,Ie for water-tub,- boilers .'.'.'.'.'.'.'.'.'.I'.'. 1006
-ft-.SMI Boiler Code for 6k tube b-il.T: [ ,',
May 25, 1915
P U \Y E R
wmT&v Iff"
SYNOPSIS— Our observant friend, Will, while
reading the advertising section of his technical
journal, sees a statement that he cannot verify,
so he carries the problem to Chief Teller.
"Say, Chief, I saw a statement last night that has me
puzzled."
"What is it, Will?"
"An advertisement which says that a rise of 10 deg.
in the temperature of the feed water represents a saving
of 1 per cent, in the coal bill. I can't see how they get
that ratio."
"Let's see if we can figure it out, Will. Take youi
steam tallies and see what the total heat in steam is at.
say atmospheric pressure."
"It is 1150, Chief."
"What does that 1150 mean?"
"It means that it requires 1150 B.t.u. to convert one
pound of water from 32 deg. into steam at atmospheric
pressure."
"Right, Will ! Then 1 per cent, of the total heat would
he what? We just had a little percentage the other
day."
"One per cent., or one one-hundredth part of 1150, is
11.5. Chief."
"Then each 11.5 B.t.u. added to the feed water to be
made into steam at that pressure would represent 1
per cent., would it not ?"
"Sure."
"And 11.5 B.t.u. would raise the temperature of the
feed about 11.5 deg., so that for this case a rise in tem-
perature of 11.5 instead of 10 deg. would make a saving
of 1 per cent., eh ?"
"Yes, Chief, but the total heat is not the same for all
pressures and that would make the percentage different,
I should think."
"Yes, that is true, so look down the column of pressures
and vou will sec that at about 25 lb. pressure, the total
heat is 1160 and at 42 lb. it is 1170 and at 71 lb. it is
1180 and at 123 it is 1190, and when the pressure reaches
227 lb. the total heat is an even 1200 B.t.u. In each you
simply point off two places, so in the latter case, of course,
12 deg. per lb. of iced water or 12 B.t.u. would represent
1 per cent. That part of the calculation is easy to under-
stand, is it not, Will ?"
"But, Chief, the feed water is seldom freezing cold.
Wouldn't that change the figures or percentage ?"
"It surely would, and that is what brings the figure
down from 11.5 or 12 to about 10 for the ordinary ease.
For example, to change a pound of water at 32 deg. into
steam of 100 lb. pressure takes 1186 B.t.u.. but if the feed
water were 200 deg., there would already be in it 108
B.t.u. more than in water at 32, so that there would have
to be added in the boiler only 1186 — 168 = 1018 B.t.u.,
and the addition of 10.18 B.t.u. per lb., or the raising
of the temperature 10.18 deg.. would save 1 per cent. So
it is true that ten degrees' difference in the temperature
of feed water will make a difference of 1 per cent, when
the temperature is around 200 deg., and this is where it
ought to be, but as the steam tables arc based on the total
heat in the steam above 32 deg.. the calculation must be
from that point as a base. AH the heat that the water
contains above 32 deg., no matter from what source ob-
tained, must be deducted from the original total heat,
then the percentage of the remainder calculated as before.
since we are interested only in the heat that has to be put
into the water at a given temperature to convert it into
steam at the desired pressure. The calculation, however.
is just as easy as in the first instance, for all that is neces-
sary is to subtract the amount of heat in the water above
32 deg. from the total heat in the steam as shown by the
table at the desired pressure, then point off two places,
as before. This will show you at once the number of de-
grees the water must be heated to equal 1 per cent, of
the total heat required under these conditions.
"For example: The sun in heating the water in the
pond to 78 deg. has contributed 4(5 B.t.u. per lb. toward
converting it into steam which, for atmospheric steam,
would be 1 per cent, of the total heat required. Since, as
shown, 11.5 B.t.u. equals 1 per cent., then 46 would be 4
per cent. Then to complete the process there will be re-
quired 1150 — 46 = 1104 B.t.u. Pointing off two places
as before, 11.04 is 1 per cent, of the remaining heat re-
quired, so that 11.04 deg. added to the feed water will save
1 per cent, in B.t.u. Now, suppose a small heater con-
tributed 6 per cent, of the remaining 1104 B.t.u. or added
6614 deg. to the feed water (1',' of 1104 = 11.04 and
6% = 66.24), then 46 + 66 = 112 B.t.u. would have
been added to the feed water, leaving 1150 — 112 =
1038. Then suppose an economizer in turn contributed
6 per cent, of the remaining 1038 B.t.u., or added 62.:'.
deg. to the feed water (1 per cent, of 1038 = 10.38 and
6 per cent. = 62.28 or, for easier calculation. 62.3), then
46 _|_ 66 + 62.3 = 174.3 in all have been added, and the
total heat the furnace would have to supply would then
be 975.7 B.t.u. and the feed water is entering the boiler
at a little over 32 + 174.3 = 206.3 deg.
"To sum up this part of the story : In the first calcula-
tion 11.5 deg. rise in temperature of the feed water
equaled 1 per cent, of the total heat required ; in the sec-
ond, 11.04 deg. equaled 1 per cent, of the remaining
heat required; in the third, 10.38 deg. equaled 1 per cent.
of the remaining heat required. So you see there is no
fixed amount which equals 1 per cent, under varying con-
ditions, even with a 100 per cent, efficient plant."
"The 1 per cent, for ten degrees is only approximate,
then ?"
"That's all."
"And the saving is in heat units, not in coal?"
"Yes, but what's the difference? You have to burn
coal to get heat units, and if you save half of your heat
units vou ought to save half of your coal."
"But the saving ought to be greater with a poor outfit
than with a good one."
"How so '.'"
"Why. with a boiler of 80 per cent, efficiency I would
only have to develop -^ (= 1.25) X 10 = 12.5 B.t.u.
m the furnace to put 10 B.t.u. into the steam, while with
;o>
P 0 W E B
Vol. 41. No. 21
a boiler of only 50 per cent, efficiency I would have to
develop 20 B.t.u. in the furnace for each ] 0 in the steam.
If the feed water is 10 deg. hotter it will save only 12.5
B.t.u. per Hi. in the case of the SO per cent, boiler, but 20
in the case of the 50 per cent, boiler."
"That's right, the heating of the feed water for a poor
outfit saves more in heat units and in coal, but the same
in per cent.'*
"How can that be ?"
"What is 50 per cent, of 5 pound> '-'"
"Two and a half pound-."
"What is 50 per cent, of 3 pounds ':"
"One and a half pounds."
"But it is 50 jjer cent, in each case."
"Sure."
"Well, with the 80 per cent, boiler you must develop, as
you say. 12.5 B.t.u. in the furnace in order to get 10
into the steam. A saving of one B.t.u., or 10 per cent.,
in making the steam would make a saving of 1.25 B.t.u. in
the furnace. With the 50 per cent, boiler you would
have to develop 20 B.t.u. in the furnace to get 10 into
the steam, and the saving of 1 B.t.u., or 10 per cent.,
in making the steam would save 2 B.t.u. in the furnace.
Do you get rue !'"
"Yes."
"For the poor boiler the saving is 2 B.t.u. as against
1.25 for the good boiler.'"
"Yes."
"But 2 is 10 per cent, of 20 and 1.25 is 10 per cent, of
12.5, so that the percentage of saving is the same in both
cases, notwithstanding the actual saving is greater in t la-
case of the less efficient boiler. If you save half your
coal when you are using 10 tons a day, it will be more tons
than it would if you saved half of only six tons a day.
but it will be one-half in both cases.
"The next question arises as to how much each B.t.u.
is worth in money, which means the cost of the fuel, the
labor, etc. If the fuel is cheap the loss, of course, is not so
great when heat is wasted, yet the price per ton may be
low and still the cost of the B.t.u. it contains or that
transferred to the boiler may be high from several causes :
low heat value, high cost of labor and unfavorable loca-
tion being among the things which make it so. There-
fore, the calculation must take in the cost of the B.t.u.
at different places, by the same course of reasoning. If
each B.t.u. in the fuel costs twice as much at one place
as at another, then the heat put into the water from
some other source is twice as valuable. So you see. Will,
only the first general statement can be made which will
be universally correct and comprehensive.
"In short the B.t.u. in the water must be consid-
ered 100 per cent. It is all there. The efficiency o(
the B.t.u. in the coal is variable and dependent on the
equipment. The cost of the B.t.u. in the coal influences
the value of the B.t.u. in the water, and the cost of get-
ting the heat transferred from the coal to the water
must be considered for a complete analysis. Does the sub-
ject seem clear to you now. Will?"
"Yes, thank you. Chief, and it has given me a better
miderstanding of the necessity of watching the feed-water
temperature more closely. I think 1*11 take more interest
in that thermometer on the feed line after what you've told
me."
Ha 31 II €Sa§>e~'GiIl^.ss
Tht Hill Pump Valve Co., 18 E. Kinzie St., Chicago,
111., has recently perfected
a new gage-glass possess-
ing two distinctive fea-
tures It is easy to read
and is protected again>t
breakage to an unusual
degree. Xo metal touches
the glass. It is held in
place by rubber gaskets
and is free to expand or
contract. Three support-
ing arms keep the upper
and lower connections in
alignment and protect the
glass against breakage.
Should it break, the arms
will keep the broken pieces
within the inclosure. On
the inside the arms are
white, so that the glass
may be easily read from
any angle. To prevent con-
densation from running
down the sides of the glass
and making it less trans-
parent, a funnel has been
provided and is centered
so that the water will drop
down through the center
of the glass. The rubber
gasket and the funnel tend
to prevent corrosion at the
top of the glass, and the
former reduces breakage,
which is more or less com-
mon when inserting a
glass.
The Discovery of Oijaen is generally credited, to Dr.
Joseph Priestly, an English clergyman and scientist. The
date, Aug. 1, 1774. is commemorated as the birthday of modern
chemistry. At about the same time two others made the
same discovery: Scheel, a Swedish apothecary, who called it
"fire air"; and Lavoisier, a French chemist who called it
oxygen, meaning "acid former." To Lavoisier is due the credit
for the true explanation of combustion.
m
Development of Switchboards — In the modern electric gen-
erating station the protective devices represent the highest
class of design and workmanship in the entire installation,
while tlit- cost of the switchboard frequently nearly equals
that of the plant controlled by it. In the old days, however,
says J. Gardner, writing in "Vulcan," lew or no protective
devices were installed. For instance, in a power station still
running there are several 2000-volt 300-kilowatt single-phase
generators controlled by open single-pole switches of the
simplest type and without even a fuse in circuit; one side of
the system is grounded. Everything operates quite satisfactor-
ily until a cable gets grounded or someone makes a mistake;
then there is a serious accident. A case of this kind recently
occurred. A direct-current generator coupled to a steam en-
gine was being run up in readiness for paralleling with other
machines. When the volts were about 100 the attendant
closed the main switch of this machine by mistake. Although
the fault was discovered immediately, the rush of current into
the machine pulled the armature winding partly round the
core, and some of the commutator segments were nearly
forced out of the V rings. The driving pins in the armature
were sheared off and the insulation of the core was damaged.
The armature had to be entirely rewound and the commutator
rebuilt.
Hill i; lge-Glass
May
r o w
;oo
Failed to Eecognize a Thermometer
In our plant we have both steam and hot-water boilers.
The chief engineer hired a fireman recently, who had had
an engineer's license for over fifteen years and who knew
all (?) about engines and boilers. One day the Chief
asked me to see if the water was hot enough and to
look at the fire, as the demand was heavy. I looked
and said, "Yes, it's 160."
After that the fireman, when asked how the fire was,
would say, "Fine! I have 100 lb. on it," never realizing
that instead of 160 lb. of steam he had 160 deg. It
was about three weeks before he "caught on" that it
was a hot-water boiler. — Antoinette Vonasek, Xew York
City.
"In the Goon Old Summer Time"
The Winn trap shown in section in the accompanying
illustration is designed for use on vacuum vapor and
modulation systems of heating. It consists of an outer
casing made entirely of brass, the valve seat forming an
integral part of the casing. A ground-joint union tail
piece attaches the trap to the heating unit. In the casing
an expansion element, consisting of a seamless corrugated
bronze tube which is filled with an expansion liquid, is
inserted. The valve head is attached to the tube, and
when steam comes in contact with the latter, the liquid
The retreat from the tiring line.
the New York "Wi'trD
When the Wind Fails
A windmill for pumping water from a mine 60 ft.
deep, recently installed and having a wheel mounted on a
tower 60 ft. high on the bank of the mine, was an object
of interest. Beside the railroad track the section gang
during the noon meal discussed the unreliability of power
that was available only when the wind was blowing.
The typical section boss, a middle-aged man, had said
nothing for some time, but finally he could stand it no
longer and he broke in with: "You fellows have bright
ideas. Do you think these people are going to wait for
wind when they have water to pump ? See those cranks,
arms and bevel gears. They can put wind on those vanes
any time that they have a mind to." This ended the dis-
cussion, as no subordinate dared to question the knowledge
of his superior.— '/'. //. Reunion. Pittsfield, Muss.
Blind lock nut
Expansion element
Protecting sleeve
Ground joint union
Details of the Winn Expansion Trap
inside expands and pushes the valve head to its seat.
As soon as water collects around the tube the liquid con-
tracts and the valve opens, permitting the water to pass
through into the return line. A long sleeve guides the
valve head to its scat and protects the corrugated element
against scale and dirt.
The Winn trap is a modification of the "Welo" trap,
which has been on the European market for many years,
It is now being built in the United States by the Detroit
Steam Specialty Co., Kerr Building, Detroit, Mich.
One of «he F.ffects of Superheat— Superheating: steam in-
creases its volume a different percentage for different pres-
sures and temperatures. For example: Steam at 100 lb.
pressure superheated 100 deg. expands approximately 16 per
cent while 200 deg. increases its volume 31 per cent, or 15
per cent, for 100 deg., and 300 deg., 45 per cent., or 14 per
cent, for 100 deg. For any desired case see the steam tables
giving the specific volume of saturated steam, subtract this
from the specific volume for the degree of superheat, divide
by the specific volume of the saturated steam, and t>.3 result
will be the percentage of increase in volume. (The same
process gives the percentage difference in volume between
two different degrees of superheat.) The amount of work
steam of a given pressure will do is very nearly in direct
proportion to its volume, hence one of the advantages of
superheating.
710
POWER
Vol. 41, No. 21
HlftSftiiaill gur&d ©p©S°Sifeiinig C@SftS ©f dentals should be ample. No building has been taken into
RefEHgea-aftiosa Plants consideration because small refrigerating plants are usu-
ally located m some part ot an existing building.
By Robert P. Kehoe The advantage of making calculations of operating
As the figures given by manufacturers to represent first costs on a yearly basis cannot be doubted. In fact, the
cost, cost of operation, upkeep, etc., are often incomplete, daily operating expense alone is misleading, particularly
the following tallies will be found useful by operators and when the yearly load factor is low and a comparatively
owners interested in refrigerating and ice-making plants short period of operation must bear the depreciation and
of comparatively small capacity. upkeep expense for the year.
Table 1 refers to refrigerating plants. No particular The total cost per ton of refrigeration per day is inter-
application has been considered and the data may be used esting when compared to the cost of using ice for the same
for any of the branches of refrigeration, such as general purpose. Ice is seldom delivered for less than $2.50 to
cold storage, markets, hotels, apartment houses, water- $3 per ton, even in large quantities, and often the price
cooling plants, fur storage1, drygoods stores, and hospitals, is $3 to •$-!. The table proves that much saving can
The estimated first costs are necessarily approximate, be accomplished by the refrigerating plant, without con-
A refrigerating equipment for a hotel will cost more than sidering greater convenience, elimination of slop from
a refrigerating plant used solely for cooling water. Again, melting ice and better preservation of perishable goods
the same size plant in one hotel may cost more than in under lower temperatures.
TABLE 1. COMPARISON OF INITIAL INVESTMENT, DAILY AND YEARLY COSTS OF OPERATION OF REFRIGERATING PLANTS. WITH
DIFFERENT KINDS OF MOTIVE POWER
Refrigerating capacity in
tons per day of 24 hours. . 10 15 20 25
Electric Oil Electric Oil Electric Oil Electric Oil
Kind of Power Steam Motor Engine Steam Motor Engine Steam Motor Engine Steam Motor Engine
Investment for complete
mechanical equipment of
refrigerating plant $5000 00 $4500.00 $5300.00 $7000.00 $6400.00 $7400.00 SS000.00 $7300.00 $8400.00 $9200 00 $S400 00 $9500.00
Daily operating expense:
Labor during night and
day (assuming that engi-
neers, etc., are also re-
quired for other purposes) 2 00 1 50 1 50 3 00 2.00 2 00 3 50 2.50 2.50 4.00 3.00 3.00
Fuel:
Coal (Q] $3.50 per ton; oil
@ 3Ac. per gal.: current
@ 2c. per kw. hour 3.50 4.80 1.50 4.75 7.20 1.80 6.00 9.60 2.20 7.00 12.00 2.50
supplies....' 0.75 0 75 0.75 1.00 1.00 100 1.25 1.25 1.25 1.50 1.50 150
Net operating expense per
day $6.25 $7.05 $3.75 $8.75 $10.20 $4.80 $10.75 $13.35 $5.95 $12.50 $16.50 $7.00
Daily operating expense for
60 per cent, of year at full
capacity 1350.00 1523.00 810.00 1889.00 2204.00 1037.00 2322.00 2884.00 1286.00 2700.00 3564.00 1512 00
Full labor expense for bal-
ance of year 288.00 216.00 216.00 432.00 288.00 2S8.00 504.00 360 00 360.00 576.00 432.00 432.00
10 per cent, of investment
to cover depreciation, re-
pairs and incidentals. . . 500.00 450.00 530.00 700.00 640.00 740.00 S0O 00 730.00 840.00 920.00 840.00 950 00
Total annual expense $2138.00 $2189.00 $1556 00 $3021.00 $3132.00 $2055.00 $3626.00 $3974.00 $2486.00 $4196.00 $4836.00 $2894 00
Total expense per ton of
refrigeration per day ... . $1.00 $1.00 $0.72 $0.93 $096 $0.64 $0,84 $0.92 $0.58 SO. 78 $0.89 $0.54
another. The figures are a good average, and the compari- The economy of oil engines as compared with ordinary
son between the costs of plants with different drive is steam plants and electric motors using central-station
quite correct. current at average rates is quite evident. In the smaller
Those who now operate plants and know what their sizes of refrigerating and ice-making plants considered
equipment cost can use the table to advantage in adding in the tables, the cheaper cost of operation is even more
or deducting to the same extent as indicated in the table pronounced because small steam plants are not usually
to determine the difference in cost of other methods of economical, while small oil engines perform almost as well
drive. Then by applying the actual costs of labor and as large units.
fuel, which are known, in the same manner, it may be It may not always be advisable to install an oil en-
ascertained how economically each plant is performing gine, on account of local conditions which may favor a
and if improvement is possible. steam engine or electric motor. Steam may be required
Refrigerating plants of from ten to twenty-five tons' for other purposes. Sometimes the power plant may have
daily capacity are seldom operated by men engaged to to be located in such close quarters that only an electric
do nothing else, but usually by men required for operat- motor can be used to preserve sanitary conditions. Some-
ing other machinery. This has been considered in the times it would be inadvisable to place an oil engine or a
table. The figures may be easily corrected to suit local steam unit in the crowded basement of a hotel, restaurant
conditions, and the price of fuel also regulated to cor- or hospital where other work is going on and perhaps
respond. The table represents a fair average. where foodstuffs are handled. But if the location and
The 60 per cent, yearly load factor assumed should be requirements do not favor other power, the oil engine
close to actual conditions in the majority of plants. It will afford a marked saving in the yearly expense,
will be noted that the labor charge has been carried The table which refers to ice plants is arranged on a
through the whole year. The 10 per cent, added for de- basis similar to the table for refrigerating plants. The
praciation and repairs can be divided about half and half, cost of a special building is included, and the labor is
A 5 per cent, yearly depreciation means complete re- calculated to be used for the ice plant alone. Only half
newal in fifteen years if the 5 per cent, is calculated as the labor is included during the balance of each year
a sinking fund; 5 per cent, yearly for repairs and inci- when the plant is shut down or not operated at full ea-
711
.» ». .am POWER
May 25, L915
, , , ,- • „ f,„. ,i,f t total nrnducin"- cost of $3.2: per ton when the ycady
pacitv. Moreover, special tabulations are given fo id- a tpta 1 m Jg H^, ^ tion.
Lent yearly load factors The unportance oi tins facta > put 1 cqunaL ^ q{ ^
F^KSn^ttft: "fS opeLtion^duces - per ta. to $1.82.
Capacity in Tons of Ice_ 15 — "Fl-trie Oil Electric Oil
per Day of 24 Hours 1" oa Electric 0,1 Electric Ul ^^ E
r"?;::; £ fe T£ *£■ h s s s £ « & &
w«=j^ -—- . — «-»•— ^r^r^Ttrtrtrt:
°&CSJ=E-:.. ].. is IS !:S8 8:8 || « « « is IS IS
One night tankman
Extra labor
Fuel: Coal @ $3.50 per . 50 30 00 6 56
ton; oil @ 3 Jc. per gal.; , fi3 10 00 18 00 3 94 13 00 23 00
current (■> 2r per kw.-hr 7.00 12.00 ■> 3 ?5
Ammonia, oil. waste and 15f) , 25 2 25 2.25 3_00 ^J^OO^ _J^_ °
supplies 1-°" • .
Net operating expense per ^ M $u ^ $21 75 |29.76 J15.69 $26.00 $37.00 $18.25 $3175 $44.25 $20.81
daV Year,y Summary-50 Per Cent. Load Factor <6 Months' Full operation)
^SS^^, ,3780 00 $2,004.00 $3,915.00 ,5.355 . 00 ,2.825 . 00 $4,680.00 S6.660.00 $3,285.00 $5,715.00 ,7.965.00 $3,746.00
H^^'^cnse'for*2' ^ ^ mM 855 —0 900.00 900.00 900.00 1,125 00 945.00 945.00
balance of year '" ■'
Fixed charges; Ro5 00 750.00 665.00 750.00
5 per cent, depreciation 5-- ,„, 500 0(1 575 00 625 00 550.00
rgA-sssaita ;;:,;; ;,nm ;nno „,.„, „.„ „» ».» ».« 150.00 »..« !».« ^
Ss5S|St 6W) M , , 57S ,,„ „ 700 00 775 00 000.00 ^0_ _875^0_ tm^ ^65^ il050:00_
™™ -'" '^^ „,, ^,860.CK, $10,720.00 $6,671.00
S^ffl^^^,., ,7mo0 ,700 00 2700 00 3,™, 00 3,600.00 3,00 00 ,,,00 4,500,0 4,500.00
duced annually... . .. 1,800.00 L.SUU.W
Total cost per ton of ice per 3 03 g_15 2 33 2.79 1.91 2 02 2.52 1.62
annum ^
Average selling price to 0 „ ,. 2 g, , 96
make 10 per cent, on m- ^ g fi(| , 7g 2 93 3.31 2.48 2.52 2.B7 ~. Jo
VeStmeDt Yearly Summary— 12 Per Cent. Load Factor (5 Months' Full Operation)
Daily, operating expense $1. 745. 00 ,3.262.00 $4,463.00 $2,204 00 13.900.00 $5,550.00 $2,738.00 $4,763.00 $6,638.00 $3,122.00
during fuU operation . $2,400.00 **1W ,050 00 1313 00 1,103.00 1.103.00
■fiiftWrr..^ »•» »-s lolSSo JSS i.K iS&S J3B:8 i:« jK k^i^i«
Sttr.^eepro:$4;32~,41^00 x,50000 ^ 2,250,0 2,2.50.00 3.000.00 3.000 00 3.000.00 3,750.00 3.750.00 3,750.00
duced annually.... l.oou.uu i.ouv. 2 5_ j _0
Total cost per ton ice per , ^ , 56 3 02 2.06 2.21 2*0
annum..... .••■■•■ -ss "• 2 39 2.73 3.07 2.26
Average selling price to 3 20 3 27 3 54 2.76 2 81 3-<S
d*. T;f"",.iT™*..~oo ,*.».«. ««•.» >«.««, »..„» «. ...««.» ■».» «.<"•«> «■'«"» »•»»'» B"0'°° $2'"'™
■SSS=:- s» s« ,ss w> »s »u bm isb ssbsesss
^!I-::S.«^^^«^« = -*- -: -:
Number of tons of iee pro- , „00 00 1200 00 1,800.00 1,800.00 1.800.00 2,400.00 2,400 00 ..400 00
duced annually.... 1,200. uu 1,-00." o 2 79 lgl
Total cost per ton of ice per 2 82 2 g2 3 35 2.50 2.50 2 98 -iu
annum ;•••;■ a-w „ „. , „- 9 art 317 3.43 2.61
Average selling price to 7g 3 gl 413 3.31 3.2o 3 60 2.8J
make 10 per cent. . . . ^ Summar>._25 Per Cent. Load Factor ,3 Months' Full Operation)
Daily, operating "pen* ,1.958.00 $2,678.00 $1,412.00 $2.340 00 $3,330.00 $1,643.00 $2,858.00 $3,983.00 $1,873.00
4Zffi» J.013:00 l^OO 1.0,3 00 ,.283 00 1;283;00 1.^,00 1;350;00 ^ ^ » ffi ffi
s— ^^iWs=5-i=ssi = s -— <^ -:: -::: «■: ~: :;:::
Number of tons of ,ce pro- ^ , 3-0 w ,,350.00 1,350.00 1,800.00 1,800.00 1.800(H) —11
duced annually... »""• „„ , q, 318 2.34
Total cost per ton ice per 4 33 g 5Q .,-, 3 nl 3.08 3.00 3.43 -OS
Av^rselUng price to . " i ^ ., fi9 4 94 423 4 00 4 31 3.55 3.89 4.04 3.27
make 10 per cent 5- ^ Summary-58 Per Cent. Load Factor (7 Months' Full Operation)
Daily operating e^nse „ ..^^ $3.295.00 $5,460.00 87,770.00 .3.833.00 $6,668,0 $9,293,0 $4,370,0
-CfSS^g M ,H JM JStS .» !:K !:K»»i»]»
^1:1^::$^$^
Number of tons of ,ce pro- Q 2,100.00 3.150 00 3,150.00 3.150.00 4,200.00 4,200.00 4,-00 00 0,-0)00
duced annually.... 2,100. uu i.iuu.uv .„-«..= 1 B5 1 90 2.32 1.42
Total cost per ton ice per ., g. 0 0(. , 2, , 72 1 83 1.95 2.4o 1.55 1.90
A^agem-lling- Price t„ " ' „ 2.33 2.38 2.S3 1.97 2.31 2.69 1.82
make 10 per cent 3. OS 3 40 -•"'
712
P 0 W E R
Vol. 41, Xo. 21
Te^iliinytf ami<
.epan2°iiinij
By J. Lucae
SYNOPSIS — Describes the fundamental con-
struction of most types of pyrometers, enumerates
their faults and shows how their troubles may be
corrected. Directions are given for making an ac-
curate pyrometer of material, most of which may
be found about the plant.
Types of Pthometebs
The mechanism of most pyrometers on the market is
actuated by the expansion and contraction of liquid mer-
cury or metals.
Fig. 1 shows a straight-stem pyrometer. Fig. 2 a high-
temperature mercury thermometer, and Fig. 3 a hori-
zontal-face or hake-oYen pyrometer. Fig. 4 shows a sec-
tion of the stem of a straight-stem instrument. A %-
in. brass pipe acts as a casing for a copper rod B welded
to a plug C screwed into the bottom of the pipe. A collar
D fastened to the pipe serves as a guide for the rod.
The top end of the copper rod is countersunk to receive
the end of a lever which transmits the movement of the
rod under expansion or contraction to a hand on a dial.
The length of the copper rod varies according to the
temperature range it is desired to register. Some straight-
stem instruments use a copper pipe on the lower end
of a brass rod. Other pyrometers have a stem made of
a piece of graphite on which is mounted a brass rod, as
shown in Fig. 5. The dial, its mechanism and the
are fastened to the end of the pyrometer stem so that the
expanding and contracting element is held between two
points, one at the lower end of the pipe, the other at
the pointer-operating lever. The coefficient of expansion
of the stem tube and that of the rod are different, and
the rod always expands or contracts more than the pipe,
its movement being multiplied by levers in the dial casing.
Fig. 6 shows the interior of a vertical-face instrument.
When the rod A in the stem expands it transmits its
movement to the pivoted pin B and to the lever C, which
carries a rack operating a pinion to which the pointer
is attached. The spring D fastened to the lever exerts
a constant pill on the pivoted pin and holds it in its
position.
The dial end of a horizontal-face instrument is shown
in Fig. 7. The movement of the expanding element is
transmitted by a pivoted pin; as in Fig. 6.
Fig. 8 shows a mercury pyrometer. A heavy, seamless
steel tube with a TV-in. hole at .4 holds the mercury. The
spring B is welded to the cap of the tube, the other end
connecting with a lever. a~ shown. The tube and spring
are filled with mercury by holding both upside down ;
before they are filled the end of the tube is welded and
sealed. The movement of the spring is not usually al-
lowed to exceed *4 m- When it does, mercury is let out
of it by unscrewing the stem at 0 until the expansion is
14 in. One should make sure that the tube is screwed in
tight again, as this joint will sometimes leak mercury
when it is supposed to be tight.
Pyrometer Troubles
Sometimes the pointer on the dial will move in jumps
instead of slowly. This indicates that there are loose
joints somewhere. The bottom plug may be loose or
dirt may have collected around the guide collar (D, Fig.
I), preventing free movement of the rod. When this
happens the rod will bend as indicated by the clotted
lines (Fig. t). and of course the instrument cannot in-
dicate correctly. To remedy this take the case off the
stem (pi]"' 1. unscrew the bottom plug and wash the
stem and rod with gasoline. The rod must be straight-
ened before the instrument is reassembled. Xow put
the stem in a pail or vessel of boiling water for a few
minutes and set the pointer on the 212-deg. F. mark.
Whenever there is no movement of the pointer for varia-
tions in temperature the usual cause is that the pivoted
pin has fallen from its bearing.
Teocbi.es Caused by Graphite Eod
The graphite-rod pyrometer is subject to a peculiar
trouble. After long service the rod seems to slowly
disintegrate, its diameter becoming less and less until
its expansion for a given temperature rise is not what
the instrument was calibrated for. The remedy, of course,
is the use of a new rod of the original diameter and
length.
A "Home-Made" Pyrometer
Many plants and shops where a pyrometer is needed
only occasionally will find the one described herewith
serviceable and accurate. A piece of tV-in. steel pipe A,
1 in. diameter and 24 in. long, is threaded inside at
one end to receive the plug B, and the other end is thread-
ed on the outside to screw into the base of the case. A
lira— spring strip C 3^x^4x30 in. is formed spirally,
having i/o-in. pitch and l£-in. diameter. This spring will
be about 10 in. long. One end is brazed to the plug B,
and the spring and plug are put into the pipe A. The
guide-disk D is then brazed or soldered to the other end
of the pipe. This disk has a 3Vln- hole to guide the
steel spindle E, tV m- diameter, which should be fastened
to the lower end of the spring by a rivet or screw before
the spring is put into the pipe. The top end of the
spindle should be pointed to permit forcing on a 5-in.
hand or pointer F. A piece of tin or sheet iron 6 in.
diameter is used for the dial. The flange G is now-
screwed into the pipe, the dial fastened, and the pointer
laid near-by, ready to be forced on the spindle. The in-
strument is now ready for calibration.
Pack the stem for its full length in a pail of chopped
ice. After about ten minutes force on the pointer, and
under and to one side mark 32 deg. F., the freezing
point. Next immerse the stem in water kept at 100 deg.
F.. as indicated by a correct thermometer. When the
pointer will move no more make the 100-deg. F. mark
on the dial. Xext heat the water to 200 deg. and mark
the dial. Also, mark it at 212 deg. The stem is next
immersed in crude oil heated to 300 deg. F. For the rest
of the dial the spaces between 300 and 400, 400 and 500,
etc.. may be divided off equally up to 650 deg. F., for
which range the instrument is well suited.
Pyrometer At. arm
Sometimes it is desired to call the attendant's atten-
tion by alarm when a certain temperature has been
May 25, 1915
POWER
713
Indicating Pyrometers and Their Mechanism. Fig. 9 Shows One That Most Any Engineer Can Maki
714
1* ( ) \Y B K
Vol. 41, No. 21
reached. This may he done by putting on the pointer
pin an adjustable piece A, Fig. 10. which is held in posi-
tion by a thumb-nut. A light flat spring is soldered to
the pointer and contact poles are fastened to the instru-
ment, as shown. The movable contact piece B is sel
over the desired temperature mark on the dial, and when
this is reached the spring on the pointer makes contact,
closing the circuit and ringing a bell.
Should it be desired to have the pyrometer indicate
the highest point reached after the temperature has
fallen, a dummy pointer may be used. This is an ordi-
nary pointer mounted as shown in Pig. 11. and which is
free to move so that the indicating pointer may push it
around by engaging the projection A on the dummy.
Usually, the dummy pointer is painted red or white so it
can be easily distinguished.
imiinig Up Small TMirfbiini*
II. Hurley*
The successful operation of any turbo-generator, turbo-
pump or turbo-blower set depends so much upon the
satisfactory alignment of the complete unit that too
much attention cannot be paid to this matter when erect-
ing these machines. The idea that because the unit is
on a cast-iron bedplate the latter cannot be sprung is
erroneous, as it is easy to twist a bedplate by wedging
unevenly or by pulling down holding-down bolts at. say.
opposite corners.
Another mistaken idea is that because a machine is
fitted with a flexible coupling, alignment between the two
ends of the unit is unnecessary. The so-called flexible
coupling will take care of a small amount of misalign-
ment and also should eliminate the thrust of one machine
being thrown onto the other. In other words, it has the
effect of making each end of the machine self-contained,
but owing to the high speed at which these machines run
it should never be assumed that a flexible coupling will
satisfactorily take care of any appreciable misalignment.
and the machines should be lined up with a flexible
coupling just as accurately as if the coupling were solid.
The rough-and-ready method of lining up with a
straight-edge across the two coupling faces, Fig. 1, often
STRAIGHT-EDGE
' ::- - . —--^]
Fig. 1. Lining Up with the Stbaight-Edge
is satisfactory, but this is only so when the couplings are
true in themselves. This condition, however, is often by
no means the case and couplings are frequently found to
be out of true on their own shaft. To take care of this
possibility, therefore, the following method of lining up
is suggested, taking into account all the possibilities of
untrue couplings in addition to the regular and orthodox
method of lining up.
Try out couplings to ascertain if they run true by
placing a straight-edge on one half of the coupling,
then by the use of a thickness gage, Fig. 2, ascertain the
high and low side of one half by rotating one half, then
take a mark at !>0 deg. from those points and use those
•Mechanical department, the Terry Steam Turbine Co.
Fig. 2. Application of tuf, Wedge
points exclusively both for horizontal and vertical lines.
Then in turn let this half stand still and rotate the
opposite half in like manner. Place the straight-edge on
both faces at those points until both flanges are flush on
the sides, allowing the regular amount on the turbine
side, top and bottom, for heat expansion for the generator,
boiler-feed pump, circulating pump, blowers or other
sets according to their different temperatures when
operating.
This same method should be used on the faces of
couplings, as it happens sometimes that couplings run
out on the faces when they run perfectly true on the
sides. In this case a taper wedge may be used to find the
high and the low points. Then, when those points are
obtained, use such liners as may be required to bring the
faces parallel.
It i- generally understood that bases are leveled at the
works before the sets are bolted clown. If this is properly
done the sets may be placed for grouting by inserting
wedges at all points where it will effect the coupling in
the direction required.
Should the set be erected on the job, then follow the
usual course by first leveling the base and allowing height
enough for substantial grouting, which is usually about
% in. ; then locate the sets as described.
Always use metal liners or wedges, as wood is apt to
shift on account of the dampness of the grouting, with
disastrous results. When the grouting is properly set
the sets should be cheeked and the bearings properly
May 25, 1915
P 0 W E R
715
washed out before oil is put in. The governor should
be worked back and forth to free it and remove rust
which may have accumulated while standing.
Many couplings arc not drilled to jig and, therefore,
the pins will only fit in the holes which are matched.
Couplings are generally stamped in a ease like this,
showing where they should be matched.
When sets are doweled at the works, or if for any
reason it is necessary to change liners, the holes should
lie again reamed when the dowels are taper and should
not he driven hard enough to stretch the metal, but
tapped slightly until the tapping becomes solid.
All flanges should be brought to the turbine or pump
square, and when rigid no soft gasket should be used to
draw the sets out of line and shear (he dowels.
In lining up generators, place chalk marks at one point
on each end of the armature; all aligning should be done
from these marks with the use of a wedge or a feeler, as
taking several points on the armature would not be correct
on account of the high spots in the banding. In all cases
make sure that the core of the armature and the core of
the polepieces are equally centered with each other so as
not to cause a thrust on the turbine bearing. The core
of the armature is always longer than the polepieces.
It is hard to decide how far out couplings can be
allowed to be and still work satisfactorily, but the writer
would say that if they are out more than l/M in. any
way, special care should be exercised in starting the ma-
chine, and if it does not run smoothly enough this should
be reported, with a special remark about the couplings
being ou1 of the true, so thai the matter may be taken up
with the coupling makers.
The mixture for grouting in a machine should be half
pure cement and half sand. After grouting, the machine
should be allowed to set for 48 hours. Foundation bolts
should be left loose or screwed down by hand until after
the concrete is set, when they may be tightened firmly.
In lining up, as previously mentioned, use iron wedges
only. They shoiud be placed under the spot where the
weight comes and as near the foundation bolts as possible.
c<
Compressors
By R. S. Bayard
SYNOPSIS — Shows by simple explanations and
plain calculations how an intake duct drawing air
at atmospheric instead of room temperature lowers
the average cost of compressed air.
It has often been observed that the output of an air
compressor is greater in winter than in summer; that is,
it seems that a machine which has had to "hustle" to
furnish air in summer, may be able to maintain the re-
quired pressure at a reduced speed during the winter.
The reason for this is often asked, so an explanation
will be of interest.
This difference can be observed only when the com-
pressor takes its air through a duct leading from the
outside air, because it is due to the effect of the differ-
ence of air temperature between the compressor intake
and the place where the air is used or conveyed through.
Imagine a cylinder having a perfectly tight piston
held, we will say at midstroke, and the half-cylinder full
of air at atmospheric pressure and at a temperature of
60 deg. F. The atmospheric pressure is, with 30-in.
barometer, 14.7 lb. per sq.in. With the piston held rig-
idly and leak-tight, assume that we can heat the cylinder
so that the air inside will become 100 deg. F. This
will cause the air to expand and try to occupy more space,
but if the piston will not move the air cannot expand,
so it will increase in pressure. Mathematically, the
pressure produced in this way will be
, a » v, 10° + 460 1 4 r> V, 56° 1*0,.™
U-7 X 60 + 460 - U-7 X 520 = l0-84 a- *" S«'m'
That is, the new pressure, absolute, will be equal to the
first pressure, absolute, multiplied by the ratio of the
absolute temperatures. (The absolute temperature is
found by adding 460 to the Fahrenheit temperature, as
done above.)
If, in the cylinder we are considering, the piston is
allowed to move as the air expands and if it lias no
friction, so that the air pressure does not increase, the
final volume will be larger than the original volume in
the ratio of the absolute temperatures. If the original
volume was, say 10 cu.ft., the final volume after the
piston has moved due to increase of air temperature will
be
100 + 460 560
iU X 60 + 460 _ 10 X 520 ~ 10-
cu.ft.
At the usual room temperatures (about 520 deg.. F.
absolute) the increase of volume is, roughly, 1 per cent,
for every 5-deg. F. increase of temperature.
Let us see how the foregoing applies to a compressor
plant. Irrespective of the outside temperature, the air
in the shop pipe lines will he nearly at the temperature
of the room by the time it reaches the tool. Suppose in
winter this temperature averages 68 cleg F. and that the
air finally reaches the tool at this temperature. If the
compressor takes in 1000 cu.ft. of free air (air at at-
mospheric temperature and pressure) directly from the
room, it will also deliver 1000 cu.ft. of free air at the
tool, because the final temperature is the same as that
at which it entered the compressor.
In summer the same conditions apply as lone- as the
compressor takes its air from the same room in which the
compressed air is used; but if the compressor is provided
with an intake duct leading from the outside air. the
results will be quite different. First, consider the win-
ter condition. Suppose the shop temperature averages
68 deg. F. and the outside air 30 deg. F. If the air
is used at 68 deg., its volume will be considerably greater
than the volume taken into the compressor from the
outside air at 30 deg. If it requires 1000 cu.ft. of
716
r 0 W E K
Vol. 41, No. 21
free air per minute at shop temperature to run the
tools, tin compressor will have to take in onlj
30 + 460
4!Hi
1 ,X68T460=1000 + 528 = 939CM^
which is a saving of over 1 per cent, in air capacity,
.-peed and horsepower. In summer, when the outside
temperature is practically the same as the temperature
indoors, there would be no saving by using the intake
duet, except, as is often the ease, when the compressor
takes its air supply directly from the hot engine room.
Thus, it is seen that the compressor would run at a
speed about ? per cent, lower in winter than in summer.
The colder the climate, the more pronounced this effei I
would become.
An actual case where the application of an intake
duct to a compressor represented an appreciable saving
recently came to the writer's attention. An air com-
pressor furnishing an average of 2500 cu.ft. of free
air per minute to a machine shop took its supply from
the basement of the engine room, where all the year
round the air, heated by a network of steam pipes,
averaged 95 deg. F., while the shop averaged 70 deg.
F. During the winter months the outside air averaged
32 deg. F.. and in summer 70 deg.
Rased upon the average consumption of 2500 cu.ft.
per min. for 10 hr. a day, the air used amounted to
an average of
2500 X 60 X 10 = 1,500,000 cu.ft.
per day at the shop end.
As the compressor-intake temperature averaged 95
deg. F.. the compressor was obliged to run fast enough
to take in
L,500,000 X
95 + 460
1,500,000 X
530
70 + 460
= 1,570,500 cu.ft.
of engine-room air per day.
The cost of compressed air in this plant was found
to be 2.8c. per 1000 cu.ft. at the compressor. Thus
the cost of furnishing air to the shop wa-
12^29 X 0.028 =$43.97 per day
By putting in an intake duct and furnishing air to
the compressor at 30 deg. F. in winter, the compressor
could have run slower and would have had to take in
only
1,500,000 X^±^= 1,500,000 X^
70 + 4 60 o30
= 1,387,000 cu.ft. per day
At a cos! of 2.8c. per 1000 cu.ft. at the compressor
intake, the average cost of air for the plant during winter
would then l»i
1,387, )
focxF
X 0.02S = 138.84 per day
During the summer, when the outside and inside tem-
peratures both averaged 70 deg. F.. the compressor would
take in only the amount used in the shop, or 1.500.000
cu.ft., which at the cost of 2.8c. per 1000 cu.ft. at coin-
nressor intake would be
With the intake dint in use we then have a daily cost
for air of $38.84 for winter and $42 for summer. The
average for the year may then be taken at $40.42 per
day. as against $43.96 with the compressor taking air
from the engine-room basement.
During a working year of 300 days, the annual cost
for air would then compare:
Without intake duct ?43.96 X 300 = $13,1S8
With intake duet 40.42X300= 12,126
1,500,000
1000~~
X 0.028 = $42 per day
Giving a net saving with the duct of $1,062
Capitalized at 10 per cent., this would justify installing
an intake duct costing $10,620. As this figure approaches
more nearly the cost of the compressor than it does the
cost "I' the duct, the conclusion is obvious.
Incidentally, the saving of $1062 per year amounts
to more than 8 per cent, of the yearly cost for air. It
certainly looks worth while to install an air-intake duct
under such conditions.
The planetary motion devised and used by Watt to
convert reciprocating into rotary motion is of interest.
first because it was brought into use to circumvent a
patent previously obtained by Wasborough on the simple
crank for the same purpose. The other interesting fea-
ture is a condition where two gear wheels of the same
diameter engage, but one makes two revolutions for
each one revolution of the other. This may be easily
tried out. or demonstrated, by using two coins with the
edges sharply milled. Hold one of them stationary with
the head up. or stick it fast with a little mucilage. Place
the other with the head up directly in a vertical line
above the head of the first. Now rotate the upper coin
to the right around the fixed coin. It will be seen that
by the time the former has reached the half revolution
or the point directly below the fixed coin it will have
turned one complete revolution, standing head up
again. Another complete revolution will be accomplished
by the time it reaches its original position. It will
therefore have made two complete revolutions while en-
gaged with a stationary coin of the same size.
It is obvious then, that if the coin being rotated were
held head up all the way around, and the other coin
made to rotate as on its center the latter would have
to make two complete revolutions by the time the two
coins had reached their original relative positions. One
revolution is due to the crank motion and the other,
to tooth engagement. This is proved by using a travel-
ing gear twice the circumference of the shaft gear,
which will produce a 3 to 1 ratio by reason of doubling
the larger gear, instead of what might be expected — a
4 to 1.
Examples of the modern application of the planetary
gear in the opposite way may be found in some geared
chain hoists and also in some automobile transmission
gears for slow speed.
Lloyds Safety-Valve Rules require that two safety valves
he fitted to each boiler, the combined area of which shall
equal at least % sq.in. for each square foot of grate area
and the accumulation cf pressure shall not exceed 10 per
cent, of the working pressure. Each valve is to be so made
that no extra load can be put on while under steam pressure.
May 25, 1915 POWER 717
gjiiiiuuiiuiiiuiiiiiiiiiiii iiiii iiiiiiii iiiiiniiiiiiiiii liillililili iiiiiiiiiiiiiiiiiiiiii in iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii i iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiin Illianillll
editorials
lllllll" ...' iil T'l I ' ,,;.; ...... IiU'i'.:,!. ■:.!!! ; : , ■ '!. ., i':.i::. ., .... . i n „„,. i:ii|<i:il!l!i'i
Mfldhngaira Es ami ILana©
Michigan made a gallant fight for the adopt ion of the
boiler code of the American Society of Mechanical Engi-
neers during the session of the legislature recently closed.
A bill (Senate Bill No. 234, File No. 299) provided for
the appointment of a board of boiler rules to formulate
rules as near in conformity with the A. S. M. E. code as
possible. It passed the Senate without a dissenting vote.
The bill was then referred to the Committee on State
Affairs in the House and two hearings were granted, but
those in charge of the bill were unable to secure the re-
porting of it out of the committee. The belief is gen-
eral that if this bill had been reported out it would have
been enacted into law with little opposition.
It is believed that at the next session of the legislature
the A. S. M. E. code will be adopted by the state and a
system of license regulations put in force.
It was discovered during the fight for the passage of
this bill that opposition on the part of the thresher en-
gine interests and the threshermen's organizations is
weakening and coming to a realization that modern boiler
practice and means for public safety must prevail and are
a good investment.
This is the first time in the history of Michigan that a
bill relating to boiler matters or engineers has passed
either house of the legislature without a dissenting vote.
Michigan is in line. Let her move up to the window
and receive her code.
The two principal sources of hazard to life around a
power plant are the boilers and the electrical equipment,
particularly where high voltages are employed. Just as
safety in the boiler room depends upon the construction
of the boilers and their intelligent operation, that in the
electrical end of the station depends upon the proper in-
stallation of the electrical equipment and the care in
handling it. The excellent work of the Boiler Code Com-
mittee of the American Society of Mechanical Engineers
in preparing its recent boiler code, has been emulated
by the Bureau of Standards, which has been at work for
nearly two years on an electrical safety code. It is
particularly fitting that this work should have been
undertaken by this bureau, devoted in its scope to scien-
tific and engineering problems and in a position to ap-
proach the subject with an open mind. While the bureau
has employed experts especially for this work, it has in no
way attempted to force its own opinions on the public,
but instead has endeavored to learn the views of various
electrical companies and, through conferences and sifting
of these views, to arrive at a set of rules which will repre-
sent the best practice.
The rules are divided into four parts, the first three
dealing respectively with the installation and maintenance
of electrical supply stations and equipment, electrical
supply and signal lines, and electrical utilization equip-
ment ; the fourth covers rules for the operation of
electrical equipment as concerns both the employer and
the employee. Part I.* which is printed as a separate
bulletin, was first published last August in- a tentative
form and was widely circulated for comment and criti-
cism. It has now been revised in accordance with a
number of suggestions and, in conjunction with Parts
1, 2 and 3, is being circulated for further criticism before
final revision.
Lack of space prevents our reprinting the rules, but we
would urge those readers who are interested to obtain
copies from the Superintendent of Documents at
Washington, and send in such suggestions as may seem
advisable.
While the Bureau of Standards has no direct power to
enforce the observance of such rules, it is believed that
most electrical companies and even private plants will
find it advantageous to adopt them. Moreover, it will
form a set of uniform rules, which public-service com-
missions or municipalities may find it convenient to
enforce.
TalrSlinigf ClhaiPil® of a )L^.^^eir
To ''make good" in the new sphere of duty is the honest
ambition of every right-minded engineer who is promoted
to larger responsibilities. Not always, however, does he
find his hopes realized under the changed conditions.
Failure to do so may be due to many causes.
Causes beyond the engineer's control cannot be helped.
Vicissitudes such as the collapse of a factory business
through changed economic conditions, the sale of an in-
dustrial plant by the owners to others who prefer to
discontinue power production locally because of repre-
sentation on central-station directorates, or the maladmin-
istration of a property through nepotism will discourage
any but the trained operator, who knows that in the long
run there is sure to be a market for his services. It is
more important to consider those factors in service over
which the engineer may maintain mastery — those policies
which lead to success when properly directed and applied
in the new field of usefulness.
On taking over a larger installation the temptation
arises to emphasize the weak spots left by one's predecessor
and to make a clean sweep of methods which at first
appear open to criticism. It is wiser to make haste slowly.
The sharpest possible analysis is commendable, but little
is lost by taking sufficient time to get one's bearings.
No installation looks the same from within as it does
from the outside, and to make a brief inspection of a
plant as a possible chief engineer, and then later to go
over the installation as its responsible executive are two
very different things. No two plants are exactly alike,
and even if similar in makeup, will not run in exactly
•See "Power," Dec. S, 1914.
718
p o w ]•: r
Vol. 41, No. 21
the same way. The engineer who takes time to learn
the personal abilities of his new subordinates and the
strong and the weak features of the equipment, individu-
ally and collectively, is wise. Lei him avoid attempting
to reform the whole institution the first week, and by
the second or third week he may find it possible to begin
to effect some real economies through the cooperation
of those under him. While a glaring instance of pre-
ventable waste should not be allowed to continue even
for a week, it pays to let the old staff discover that the
new chief is willing to learn, that he is glad to receive
the help of those more familiar than he with the local
equipment and load situation, and that he is determined
not to act mi snap judgment to impress the "boss" with
his instant ability to cut costs and make a new r&
An exceptional man may take over a new job of this
kind and almost immediately inaugurate an efficiency
policy which revolutionizes practice within the station.
Such an overturn may be accompanied by a substantial
crop of recommendations for discharge, without waiting
to find out if the men most familiar with the routine
work cannot gradually be brought to work in harmony
witli the new program. It takes time to find out what
those already on the ground can do, and a plant may fail
to do its best work for many reasons other than incom-
petency of the force. It is nearly as important for a
new chief engineer promoted from within to introduce
his executive ideas moderately. Where a subordinate
engineer is not available to promote, the new chief needs
insight and tact to get the best from his predecessor's
force.
A contented staff has more to do with economical
operation than some realize, and whether an engineer
takes charge from within or from without, a probationary
receptive period is an effectual means of getting acclimated
to his new responsibilities.
When examining operating and test records, a similar
skill in instantly "spotting" departures from the normal
is of great advantage. It takes practice to scan tabular
data rapidly without losing their significance. The start-
ing point is to know what to expect in a routine way,
and this can be acquired by continued study and observa-
tion. Roughly, each plant may be said to have a set of
"constants"' of its own. That is, the temperature of the
feed water will run between such and such limits when
every day's record of coal consumption per kilowatt hour
keeps down to the average minimum consistent with the
local conditions : the variations in steam will follow a
well-defined cycle, if this is varied purposely, or will hold
close to a predetermined zone above and below a fixed
average so long as things go as they should. Seasonal
variations will be noted in the temperature of intake and
discharge water.
It is the engineer's task to maintain normal conditions
of service and instruments help in this work, but perhaps
too much reliance is placed on automatic charts at times.
The really professional understanding of one's plant is
the kind that combines the keen ear and the microscopic-
eye with a continuous apprehension of a considerable
number of physical data which set a standard for even-
departure from efficient operation. In other words, when
the readings of instruments depart from the normal by
a certain differential, when test sheets contain figures
that jump out of the routine range for a little while, the
expert engineer notes them at once and if possible acts
promptly and reduces preventable losses.
Intense personal interest in an installation leads to
skill in diagnosing the approach of abnormal conditions
through knowledge of what seem trifles to the man of
mediocre ability or to the layman. The result is a
reduced maintenance expenditure and a better record for
service continuity, to say nothing of an almost inevitable
improvement in operating economy.
L©c«
Coimdliftloias
The ability promptly to detect abnormal conditions in
plant operation is most valuable to the engineer. Nothing
so clearly denotes the expert as immediate appreciation
of the existence and cause of any unusual sound. The
same is true with respect to scrutiny of the log sheet
and to the study of test data.
While many sources of inefficient operation are sound-
less, cultivation of a keen sense of hearing is worth much
to the engineer. With high-speed machinery, even very-
slight departures from the normal tend to become magni-
fied. Every plant has in a measure its own sound
characteristics, due to the sort of load it carries and to
the peculiar combinations and sizes of main and auxiliary
units in service. From long experience most engineers
will sense abnormalities in sound almost subconsciously,
but a new man will need to make a special effort to
develop this faculty as quickly as possible. Things happen
pretty fast when an unusual condition becomes cumu-
lative, with modern turbine and high-powered auxiliary
equipment; the value of machinery under the control of
the engineer today runs to figures far in excess of a
decade ago : and the ability to see ahead and to catch the
drift of sounds which the untrained visitor would never
notice is very important.
The Federal Government inspects the locomotive which
draws your train, and no steamer can carry passengers
without a certificate from the Federal inspector that its
boilers have been inspected and its engineers examined
and found safe and competent. The Federal Government
also requires the stationary boilers in the District of
Columbia to be inspected and requires a competent attend-
ant for them, but only four out of forty state governments
are equally solicitous for the safety of their citizens. The
people are protected when they travel, because the Federal
Government can do it. but not when they stay at home,
because the state government will not.
The troubles of the engineer are many and sometimes
unique. One of our good friends up along the Hudson
River finds so much moisture in the air used for forced
draft that in winter ice accumulates on the under side
of the grate. Sometimes, especially when the fire is about
lour hours old. ice so plugs the air spaces in the grate
that it becomes necessary to put a steam hose in the ash-
pit and melt it so as to pass enough air to keep up the
required rate of combustion.
•0.
Our contemporary. The Electrical Review of London,
"eannot approve of all methods adopted by American
consuls" in stimulating trade activity with Prance, Why-
should they ?
May 25, 1915
POWER 719
Hill WIIKIIIIIIIlllllllllllllllllllL'.'iillllllllllllllll i.l,; HIIIIII Illlllllll lllllllMlllilllllllllllllll Illllllllllllllll Illlllllllll IIIIIIIII1IMIIIUIIIIIIIIIII IIIIIIIIU
;©rresip©inidleinice
Grsis EsEpIlosnoitas isa lB©aileir
air ncmno in slowly/
CO 60IN6 OUT SLOWLY^.
Ill your issue of Apr. 20 I read the interesting com-
munication by L. A. De Blois, concerning a gas explosion
in a boiler furnace The three correspondents appear
to be at a loss to explain the formation of an explosive
mixture, or. in other words, the entrance of a sufficient
amount of air into the formed carbon monoxide under the
condition described; that is, with the fire-door closed.
the tuyeres blocked by a clinker and the damper wide
open. It seems to me that the formation of an explosive
mixture under these conditions is a very natural occur-
rence.
Carbon monoxide is somewhat lighter than air. and
on account of the higher temperature in this case it is
considerably lighter than the outside air. The open stack
with the closed furnace, there-
fore, represents a vessel having
a lighter fluid at the bottom
and a heavier one on the top.
These two fluids, if not in mo-
tion, are in unstable equilib-
rium, and it is only natural
that a slow flow of the lighter
gas toward the top on one side
of the stack and a correspond-
ing return flow of the heavier
air on the other side of the
stack would take place. I be-
lieve that the sketch will make
this clear.
The moment the fireman
broke off the clinker and there-
by opened the discharge from
the fan, rapid combustion was
Fni. 1. How
Air May
Have En-
tered Fue-
XACE AND
Cai -in Ex-
plosion
started, with a consequent development of high tempera-
ture, probably projecting a flame into the combustible
mixture. This started the explosion because the time
intervening between the opening of the fire-door and the
breaking off of the clinker was not sufficient to remove
this explosive mixture from the furnace.
It seems to me that a reliable arrangement for prevent-
ing this occurrence could be made. If the conditions of
the furnace, its operation and the fuel used are such as
to permit a constant admission of a small amount of air
above the fire, an opening should be provided in the fire-
door and it should be made impossible to close this
opening. In this case, even if the tuyeres were complete-
ly blocked, the constant, if slight, draft would remove
any carbon monoxide that might be formed.
If, however, the existing conditions do not permit this
sort of an arrangement without de-
stroying the efficient operation of the
furnace, a bypass may be provided in
the air supply, branching off between
the blower and the tuyeres and en- STA
tering the furnace above the fire.
This bypass should have in it an un-
balanced damper which is normally
closed but which opens when the pres-
sure in the air-supply pipe rises on
account of the tuyeres being stopped
£=^
U^
WITH COUNTERWEIGHT
Fig.
\\\ p iss around Grate
up. This damper (or virtually, check valve) could
easily be provided with an indicator on the outside
by which the fireman's attention would be called to the
fact that the tuyeres have become clogged (see Fig. 2).
This analysis is based only on the information which I
can gather from the communications as I found them
in Power. Should my understanding of the case be in-
correct, I would appreciate a word from Mr. De Blois,
to clear the situation in my mind.
Robert Cramer.
Chicago, 111.
rzo
P 0 \V E E
Vol. 41, No. 21
The battery in question was rated at 50 amp. at an
8-hr. rate and supplied current for lighting and for a
few small motors from 6 p.m. until T a.m. It had been
badly overloaded at times, and despite repeated warnings
Current passes from cell No. 7 to coils C and D,
thence to post E and the flat spring attached to it,
through F and G and down post H, via the hydrometer
to cell No. 1. As soon as current flows, C and D are
energized and L is Lifted and also the rod which is
attached to it. This throws the joint J upward, and the
coiled spring pulls it back, drawing F out of contact with
E and breaking the circuit. Once L has been pulled
up, it cannot fall, because the spring contacts A and B
are so formed and adjusted as to prevent it. As soon
as L bridges A and B. line current flows through the
coil of the circuit-breaker and trips that device, thus
opening the battery circuit.
If anyone should gain entrance to the engine room and
attempt to reset the breaker, the latter would immediately
open again, because by the closing of the breaker its trip
coil would again be energized. Furthermore, as the re-
lav is under lock and key, no one could reset it except
the engineer having the key.
It remains to relate that the principal offender was
the first to be caught. When he had carelessly pulled
the battery down and the circuit-breaker had opened,
he found himself in inky darkness.
William E. Dixon.
Cambridge, Mass.
Wiring of Automatic Cutout
to various people around the institution, the overloads
would recur all too frequently. Finally, it was decided
that something more effective than warnings was neces-
sary. After considering various plans, it was decided
to install a circuit-breaker which would be tripped when
the recording hydrometer dropped to a certain point.
This hydrometer was already equipped with a contact on
the pen arm, which dipped into an adjustable mercury
The photograph, Fig. 1, is of a crankpin that failed re-
cently on one of our 24x36 first-motion hoisting engines.
When the pin failed both guides broke, the rear cylinder
head was broken out by the piston, and the piston and
piston rod were ruined. The engineer shut the throttle
the instant the accident happened and threw on the brake,
thus stopping the cages where they were and preventing
a more serious damage. Fig. 2 gives the dimensions of
Two Views of Broken Crankpin
cup, so that this part of the job was very simple. It
was necessary to construct a relay to close the trip coil
circuit and install a circuit-breaker. The sketch shows
the relay and wiring diagram.
When the hydrometer reaches the lowest point desir-
able, it closes the circuit through solenoids C and D and
part of the battery. It was best that this circuit
should be broken as soon as it had accomplished its
purpose so as not to further drain the cells. This was
provided for as follows :
the pin and shows where the break occurred. This sort
of failure is what is called a fracture in detail.
It was not due to any flaw in the material, nor does
it seem possible that the pin was too small. The maximum
steam pressure carried is 120 lb., and with this pressure
on the 24-in. piston the total load on the pin would be
less than 55,000 lb. The 41/o-in. pin, the cross-section-
al area of which is lSy^ sq.in., should be large enough to
(any the load with a large factor of safety. Of course,
if there was any slack rope the starting load would be
May 25, 1915
P 0 W E I!
721
greatly increased, but the ropes are always kept closely
adjusted. No doubt the trouble was due to a fault in
the design of the pin. It will be seen that the corners
• hi both sides of the y§-in. collar next to the crank disk
are perfectly sharp, with no fillets whatever. These were
the weak points at which the fracture could start. The
%-in. collar mentioned was a part of the crankpin.
Probably it would have been better if this had been a
Fig. 2. Original Design,
Failed
Fig. 3. New
Design
separate collar shrunk on at the proper place, thereby
eliminating the sharp corners. We have three hoists of
the same size in service, and considerable trouble has been
experienced in the past with crankpin failures. Occasion-
ally, the wrecks have been rather serious. More than once
the whole cylinder was wrecked and had to be replaced.
Various grades of steel pins have been experimented with,
but the results were practically the same. So it was
decided to change the design of the pin. Fig. 3 B shows
the new design adopted. It is thought that the %-in.
radius fillets on each side of the collar will stop the
trouble. However, these new pins have not been in service
long enough to prove anything yet.
I would like to know whether any of the readers of
Powei: have had similar experiences, and if so what steps
they have taken to remedy the trouble.
F. F. JOBGENSEN.
Gillespie, 111.
P^atrmip> Woualld BJ©tt IRtmia
When a duplex tandem compound pump failed to start
it was at first thought that the steam valve had shifted,
but links A were disconnected and the valves operated
by lever B. One side of the pump made full strokes,
Conditions Inside of Pump
but the other side moved only a few inches in the center
of its travel and struck something solid.
Head C and the low-pressure piston I) were removed,
and in the bottom of the cylinder was found the nut from
the end of the high-pressure rod, and the large disk E
which screws in the center of the wall F between the two
cylinders.
Head H was removed and it was found that a followei
bolt T had dropped out of the high-pressure piston and
had worn the cylinder head about half through, at //.
This bolt was found wedged in the hole in the center of
the high-pressure piston, as shown. The bolt T was
taken out, the high-pressure piston put back on the rod.
and the large plug E put into its place. The cylinder
head C was put on, but piston D was left out, and by re-
adjusting the spools at K the pump ran very satisfactorily
until a new piston could be secured.
Albert Carpenter.
Adams, Mass.
Your Mar. 23 editorial, subject ""Lubrication,'' suggests
a few comments. Modern equipment such as high-pres-
sure compound condensing reciprocating engines, turbine.-,
and Diesel, producer gas, locomobile and uniflow engines,
air compressors of several stages, also eight- and twelve-
cylinder automobile engines, require the best oil obtain-
able; any other kind retards smooth operation. Si. me
engineers admit that their engines are better judges of
good oil than they are.
The present standard of oil analysis needs revision.
Oils varying in chemistry and physical properties mate-
rially render selection difficult. Few buyers are able to
differentiate between the good and the bad. The Independ-
ent Petroleum Marketers' Association, recognizing this
deficiency, selected a committee of experts about two years
ago to investigate this situation, but so far no report has
been made, nor has any new standard been adopted.
Most of the crude oil produced in this country, or
about T6 per cent., is of asphaltic base and of low market
price. The other 24: per cent, is of paraffin base, rank-
ing very high ; in some instances a premium is paid for
it. It is the difference between the two that puzzles many
engineers. To them the finished oils look alike, whether
Eastern or Western products, but when the asphaltic-base
oil is used under high-pressure modern conditions, the
asphalt condenses at its critical temperature. This de-
posit may be found in cylinders, packing rings and piston
rods, accumulating until sheared off. It causes engines
to labor hard, calling for increased oil supply and also
finds its way into condensers, reducing their efficiency.
Asphalt has no lubricating value and should be abandoned
when trouble presents itself.
The paraffin-base oil. mainly from Pennsylvania, has
the reputation of being the most reliable oil found any-
where. It is becoming scarcer every year. During 191 1
the production in Pennsylvania fell off 963,282 bbl. If
the same ratio continues, in about eight years it will
cease.
The widely used red engine oil, being of an asphalt
base, wears rapidly. It disintegrates after being fed to
the bearings a few time- and causes abrasion. Next, an
imperceptible wear of the metallic rubbing surfaces be-
gins and the oil finally finds its way into the lilters, dirty,
with its lubricating value reduced until it is gradually
worn out. In a short time another barrel must be or-
dered. Its ultimate cost is high. Buyers may recognize
herein why they find it necessary to order oil so frequently.
The remedy is to install an outfit which returns the used
oil to a filter, ami adopt a bright-yellow, good oil (not
acid-treated) which may he fed by drops, or in a stream in
;■.".'
P 0 W E P
Vol. 41, No. 21
hot weather. Such an oil wears longer and needs little
replenishing and that at longer intervals. Its ultimate
eosl i- low.
Under any given conditions the oil which results in the
lowest cost, owing to consumption, cost of coal needed
tn overcome Erictional resistance, and cost of repairs due
in metallic wear on metallic journals and brasses, is the
best.
A modern high-pressure compound condensing engine
requires the best oil obtainable. Such oil cannot be bought
at a low price. But it may be the cheapest in the long run.
Dependability, long service and ultimate cost are the de-
termining factors. When engines labor and groan and
valve and eccentric rods vibrate, or traces of asphalt ap-
pear, an immediate change of oil is advisable. Soft spots
may appear in cylinders, causing wear, or leaky throttle
valves, causing corrosion when the engines are idle. Or
the trouble may lie due to stale, rancid animal oil used in
animal-oil compounds, coming in contact with hot steam
and decomposing, forming acids. This causes soft spots,
and if not remedied will result seriously. No reputable
oil company wdl use rancid animal oil, or rancid wool fat
or De Gras, which may be detected by its odor. Animal
oil for compounding should lie sweet ami fresh and pre-
served in refrigerators when the temperature is above 50
deg. F.
The writer's method of handling lubrication problems
is to diagnose each case by itself. With practiced eye
and well-trained ear the remedy is simple. In general, the
modern uptodate little-drop method of cylinder lubrication
supplied by a mechanical lubricator operated from the
valve movement, when accompanied by a good oil, results
in perfect lubrication, requiring the smallest consumption,
at the lowest ultimate cost.
Joseph \V. Froiieyer.
St. Louis, Mo.
il a\H.nira§| 11 wo ©s3 iraoir© UJasigSFSifflms
Taking diagrams simultaneously is essential for the
purpose of accurately determining the horsepower devel-
oped, and also for valve setting. Sometimes it is neither
convenient nor possible to make use of the magnet attaeh-
Indicafor
Low-
Pressore
Cylinder
Operating Four Indicators
ments in handling two or more indicators. In using mag-
. nets dry batteries and wiring connections must be pro-
vided. The magnets must be delicately adjusted in or-
der to make the proper pencil mark, and considerable
time and trouble are entailed in making such adjustments.
In lieu of magnets the following method may be adopted :
At each end of a cord about two feet longer than tin-
distance between the indicator cocks make a loop about six
inches in length so that there will be no knots to interfere,
pass the loop over the pencil arm. which has been previous-
ly provided with an clastic band to hold the pencil oil'
when not indicating. We now have a flexible connection
to both indicators, and a pull on the cord will take as many
diagrams as desired.
When indicating a cross-compound engine a third cord
may lie looped about the cord on one cylinder or the latter
may lie of sufficient length to reach the other cylinder
where the operator can control all four indicators simul-
taneously. I have found this method simple and conven-
ient.
L. L. Loomer.
Waterbury, Conn.
This will help out if your stock has run out and the
pump valves have to be repaired before new studs can lie
obtained. Cut ofi the old valve stem and use the top
part B as a nut after it has been drilled and tapped, then
i a
Head Used as a Nut
take a bolt or brass rod and make a stud A. This will
answer the purpose as well as a new one. The nut may
be pinned or riveted on if necessary.
John M. Ruppert.
Philadelphia, Penn.
CoiradleirassitLIoEa fiposmi Wg\-ft©tr=
wlh©©! Csisaira^
Waterwheels expose to the air a large surface which
sweats under certain atmospheric conditions. Disposing
of this water becomes a troublesome job to the operating
engineer.
A channel or flange is usually cast around the periphery
of the sub-base and drained to the tailrace. On the
20.000-hp. units in a certain plant several hundred square
feet of surface are exposed to the heated air of the power
house and the condensation is copious. During the first
months much of the operator's time was taken up in
disposing of the condensation collecting in the drainage
channel, as the operating conditions made it inadvisable
to utilize the customary drainage tubes.
The wheel, revolving rapidly in the closed casing,
always produces a considerable vacuum at the shaft.
This vacuum was utilized through a %-in. pipe tapped
into the casing, fitted with a valve, and extended to the
drainage channel to remove the water.
Walter Swaren.
Havward, Cal.
May
1915
P ( ) W B 1?
72?
Lema©vnEas
>©ir&dl ©Easels
.Etigsiaees'S
lessffiiSiifiislmni
At the steam station serving the Twin City Lines we
have live Curtis turbines of the vertical type, equipped
with Worthington three-pass condensers. A great deal
of trouble was caused by the accumulation of air, especial-
ly in the water box at the end of the last pass. The top
of this box is about twenty-four feet above the level of
the water in the river, both the intake and discharge
pipes being submerged, making a sealed system.
Various devices were tried to remove the air, among
them the plan of tapping the top of the box and connect-
ing to the condenser, the pipe being fitted with a globe
valve which was opened and closed by hand. The ob-
jection to this scheme was thai, if the valve was opened
too wide, too much water would he taken oxer into the
An; Receiver wi> Pipe Cos \k<
Condenser
condenser. We tried to overcome this by extending the
pipe in the form of a loop pj, the upper part being aboul
Forty feet above the river level, hut we found that the
water would go over in "slugs". We then decided on
placing a separator in the uptake side of the loop, and
one was made up of 6-in. pipe and fittings approximate-
ly the same as shown in the accompanying illustration.
Later, we applied the Mason racuum regulator and have
found the 1-in. regulator, with a pipe of the same size.
large enough to handle all the air.
"Slugs'' of air and water pass up the 2%-in. pipe into
the separator through the shorl piece of pipe shown by
dotted lines, the water separates from the air and flows
out through the discharge pipe into the circulating dis-
charge. By means of the weights on the lever of the
regulator it is possible to obtain any desired vacuum in
the separator.
We have found that this device gives excellent satis-
faction, and wlen nine adjusted, it needs no further
attention on the pari of the engini ei
Geo. W. Caywood.
Minneapolis. Minn.
Some time ago there was an editorial m Power on
this Subject, and it may not hi' too soon to bring it up
again. At that time it was stated that the engineer ap-
plying for a position as salesman is handicapped through
lack of actual selling experience ami because he has no
pasl record of sales ability. The questions now arise:
What is sales ability? What qualities must the success-
ful salesman possess?
In order to approach a business man at all it is neces-
sary that one he neat in pergonal appearance; then, when
one gets to his man, one must have a fair command of
English and a pleasant disposition to start a conversation
and, once the conversation is started, self-confidence in
the line and oneself, together with a thorough knowledge
of the specialty offered for sale, to maintain the conversa-
tion until the goods offered have been shown up at their
best. There is such a thing as saying too much in some
cases; therefore, tact and a knowledge of human nature
are also required.
The qualities mentioned are the principal ones that go
into the makeup of a successful salesman. What has the
practical engineer to offer bis prospective employer in
the sales game. The engineer, to he successful in even
a fair-sized plant, must have all the qualities mentioned
above, with a few more thrown in. He must be tactful,
to keep his crew working smoothly; he must he neat about
himself and the plant; he must have an agreeable nature,
to keep peace with his employer and the tenants in
the building; he must have a thorough knowledge, not of
one, hut of a dozen and one different appliances to keep
his plant going; and he must possess facts and figures
and know how to present them when he and the central-
station man meet on the mat in the manager's office.
The engineer, therefore, can offer the manufacturer
of steam specialties the same qualities that the salesman
can, plus practical experience, which more than offsets the
lack of actual selling experience in the beginning.
The manufacturer should hear in mind a few proved
Tacts. Many a perfectly dependable piece of apparatus
has been returned to the makers ami condemned because
it failed to do what it was sold to do. Why? Because it
was installed under conditions where it could not oper-
ate efficiently, or otherwise. It was sold by a man who
was only a salesman and did not know whether it would
iperate. A practical engineer would have made no such
mistake; he would know from experience that only fail-
ure could result.
It is to the interest of the manufacturer, not only that
an appliance should operate, hut that it should' operate
at maximum efficiency. Repeal orders are the life of a
concern, ami a good piece of apparatus will fail unless
properly installed.
hast, hut not least, while the engineer is not always
the buyer he can always he the knocker. An engineei
salesman can walk into a plant, and being an ex-engineer,
he usually has no trouble making a friend of the aver-
ngineer. lie sees things about the plant an ordi-
nary salesman would not notice ami can probably make
-lions which will lead to a sale. lie asks question
the average man would not think of and gets information
which the ordinary salesman could not obtain. If there
i complainl aboul anything he usually gets it first, and
thus has the opportunity of correcting the fault bi
724
POW K I!
Vol. 41, No. 21
it goes further and causes unpleasant business relations.
While going about he can collect trade data at little or
no cost; data which usually cost the manufacturer quite
a little to secure through other sources.
The average buyer of today appears to hail from
the corn-cob state: he must be shown, and who is better
qualified to show him than the man who can get into a
pair of overalls and install and operate bis plant? All
i : gineers will not make good salesmen, but in view of
what is required of the modern engineer one can safely
say that a larger percentage of men who can qualify for
salesmanship in the engineering field can be taken from
the ranks of the operating man than from any other body
of men.
A. II. Poiilmax.
Brookhn, N. Y.
itnmp m
In the plant where I am employed a small vacuum
pump on the returns from the heating system developed a
crack about three inches long in the cast-iron cylinder of
the water end. When we overhauled it we found that the
crack did not extend through the brass lininsr and that
Plug Extended ixto Lixixg
the water got in between the iron and brass at the drip
opening. We screwed a brass plug into the drip opening
flush with the bore and smoothed it up nicely. On start-
ing the pump the crack did not leak a bit and had closed
up somewhat.
I think the pressure between the lining and the cylin-
orced the crack open, as at time- it has to work very
hard.
Howard IT. Whitaker.
West Somerville, Mass.
A Pim can sua attic Pip© Sftoppeir
Difficulties are encountered at times m clearing out
obstructed drain pipes on account of abrupt turns in the
piping, which a steel "snake" or its equivalent is unable
to pass around, and it i> necessary to use a hose connected
to the hydrant pressure to clear the obstruction.
If, however, a plug is removed and a hose connection
made, the water, instead of passing through the obstructed
piping, will ascend in risers and overflow from the sinks
or washbowls above. A case of this kind recently came
within the writer's personal experience. The 3-in. dram
pipe, with a 2-in. screw plug in the end. passed through
a basement wall. About 12 in. from the end of the pipe
a 2-in. riser extended to the floor above.
To make a water-tight connection witli the drain pipe
and prevent backflow in the riser, the device shown was
made up in a few minutes from material that happened
to be at hand. A 2-ft. piece of a bicycle inner tube,
having the valve attached, was cut off and slipped over
a %-in. iron pipe and bound tightly at each end by wind-
ing stout cord about it and the pipe. Over this a piece of
m
Pneumatic Stopper ix Use
3-in. cotton hose was placed and bound in like manner.
A line of hose was attached to the service supply and con-
I to the %-in. pipe, and the end was inserted in the
drain pipe as shown and the tube inflated with a foot
pump, which produced a water-tight coupling.
T. H.^Eeakdox.
Pitt-li.-M. Ma-.
The company for which I am working built a new plant
a year ago, and the blowoff piping was something novel
to me, although it may not be to all readers of PowEit.
The engineer who has had to go into a hot combustion
chamber and install a new blowoff pipe after an elbow has
failed will appreciate this arrangement, as it does away
with a threaded elbow. The pipe should be extra heavv.
Bent Pipe for Blowoff
and will be better if made of wrought iron, which is ea>-
ily bent. This leaves a clear passage for scale and sedi-
ment in blowing off the boilers, and if properly protected.
I see no reason why it should not last for years; it will
certainly reduce the danger from water-hammer and el-
bow failure. The company furnishing this equipment
always uses a bend instead of an elbow, wherever possible.
J. A. Epplt.
Thomasville, Ga.
May 25, 1915
POWER
725
Ana HDsrmoirggeia©;^ (GrSi§E5.<e&
The writer has used a gasket for a steam main, made
as shown in the illustration. Long pieces of lead rope
were inserted between the pipe flanges and wound around
the bolts. A mixture of red lead and linseed oil was
then added, the whole being flattened and spread out by
Lead Rope as a Gasket
the strain on the bolts. Tins form of gasket may be
tightened as required from time to time, taking care that
the lead does not spread too much and project into the
bore of the pipe.
T. W. Reynolds.
New York City.
S5^EBSiE=(Cnsr,<E^fl5ft MsiES.©°®s.Eadl'=]Bs3@siBi
Use a U-tube of glass or iron pipe, into which the
wires should be fastened by pushing through a cork and
varnishing, or, if the tube be of glass, they may be fused
in place. The tube should then be filled with mercury
to a point slightly below the ends of the wires and enough
oil put on it to cover the tips of the wires.
The loosely lifting piston is to be placed in the other
Electric Circuit Completed by Wise of Mercury
side of the tube and so connected to the float or mech-
anism that is to operate it, that it will be depressed and
displace enough mercury to cause the column to rise in
the opposite side and close the circuit by submerging the
points of the wires. This will be accomplished away
from the air and under oil, and may be used with safety
around gas or other explosives.
This device does not require attention, as the oil can-
not "creep out." It can be made as acid- and fumeproof
as the electric conductors themselves, and also "foolproof."
II. King.
Wilkinsburg, Penn.
The illustration shows a high- and low-water alarm for
a tank, which we developed after considerable experiment-
ing.
The situation was more difficult than usually met with,
on account of the water being supplied to the tank by
two pumps discharging at opposite ends of the tank, the
agitation 'causing waves which kept the float and switch
in almost constant motion.
A casing open at the bottom was fastened inside of the
tank in which the float was placed, and after this the
Float Inside OF C ISING
surface agitation had little effect. The rising and lower-
ing of this cork float opens and closes the electric circuit
which rings the alarm bell in the engine room. The
float fits in the casing so as not to turn over, and the
light chain allows considerable variation in the water
level before the alarm sounds.
Irving Cobb.
Atlantic City, N. J.
nim ftlh© CoIldU
A water-heating plant gave oil' various noises and our
steam fitter was called to remedy it, and I was invited to
go along. The heater was in the basement, and as we
entered, the pipes gave off a continual chatter, then got
quiet for a time, and then jerked in a way likely to tear
the piping out.
At first we thought the steam fitter had got confused
in his connections at the top of the tank, but the system
had been in successful operation one winter. After find-
ing this connection right we took down the cold-water
pipe and found a piece of broom handle inside, which at
rirsi was a loose fit in the pipe, and it let the water past
Eor ;i Imic. but had filled with sediment, with the results
inciil loiieil.
J. N. Woodruff.
W. Liberty, Ohio.
726
POWE K
Vol. 41, No. 21
§&©^sini So C©EaSrsil E5esiS<=
air&gi §>;^§<t©ffini
The Northwestern Electric Co. operates an IS, 000 horse-
power hydro-electric plant on the White Salmon River. The
plant supplies energy to the City of Portland. Ore. A re-
serve was needed in order to back up the water-power sta-
tion. The plant installed is described by G. Broili. in the
"Journal of Electricity, Power and Gas." It was found that
in order to serve the public properly, either a storage battery
or a steam plant would have to be installed. The steam plant
was finally chosen because of the possibility of installing a
central heating system.
Two 3500-kw. turbines were placed in the basement of a
large Portland office building. These turbines operate non-
condensing and act as voltage regulators on the electric
end by varying the field excitation. The turbines can be
made to carry enough load to furnish the steam required for
the heating system, or the steam can be bypassed through re-
ducing valves, or a combination of both can be used. As the
turbines are always connected to the electrical system, they
will quickly take up the load should there he any interrup-
tion of the service from the water-power plant. No delay
can take place, such as often happens on many hydro-electric
systems where the steam plant must be brought quickly into
operation in emergencies. These turbines are ready to put
out their full capacity at all times for an indefinite period,
which is not the case with a storage battery.
In ordinary operation one or two turbines are run and all
the steam required for the heating system goes through the
turbines, carrying a part of the load. An automatic governor
developed at the plant keeps the low pressure to within one-
half pound of whatever is required. The plant has been
operating successfully since starting. The boiler pressure is
185 lb. with 125 deg. superheat. The amount of superheat is
greatly reduced in the turbines, but when any steam goes
through the reducing valves, there is trouble in the heat-
ing main due to the excessive superheat. "While a cold spray
of water in the heating main beyond the reducing valve will
absorb the superheat, experiments are in progress to perfect
a system that will be more desirable.
The results obtained show that the central-station ser-
vice is financially satisfactory, not to mention the item of
service which is hard to estimate in money. Steam heat has
been furnished for one year to an office building with 152,000
cu.ft. of space, and 1321 sq.ft. of radiation. In a previous
year, the fuel cost was $438.40 and the labor cost $520, mak-
ing a total of $95S.40. The steam heat from the central sta-
tion costs $520 for the year, thus making a saving of $438.40
over the fuel costs in the private plant. Another case is given
of a well-built hotel, three years old, with 640,000 cu.ft. of
space and 3650 sq.ft. of radiation. The fuel cost during 1913
in the private plant is compared with the net central-station
steam cost for 1914 in the following table:
Private Plant Cent. Heat.
Month l Fuel only) Total
Januarv $194.60 $145.58
February 174.65 11S.5S
March 124.75 S0.00
April 99.80 67.86
Mav 99.80 55.10
June 24.95 31.50
Julv 24.90 40.50
August 49.90 44.01
September 49.90 71.28
October 99.80 99.50
November 123.75 123.53
December 212.54 132.43
$1179.34 $1009.87
These figures show a fuel saving of $169.47. but in addition
to this there was a saving made in labor amounting to about
$1200 per year, making a total of about $1370. It will be
noted that in the milder months of winter and in summer,
central-station service exceeded in cost the amount paid for
oil fuel for the private plant. This is explained by the fact
that with central-station service better heating is enjoyed at
all times and more hot water is used because of its being
available, thus giving the hotel tenants a much more satis-
factory service in every way.
The pressure in the heating mains is about 5 lb. Two
20-inch lines leave the station, and the sizes are gradually
reduced. The lines are tied in w-ith cross-lines wherever pos-
sible. Condensation in the mains averages about 0.025 lb. per
hr. per sq.ft. of pipe surface and is practically constant re-
gardless of the load or time of the year. Radiation of heat
from the underground pipes is reduced to the lowest possible
amcunt by the use of a very efficient insulation made to sur-
round the iron steam pipe. First a layer of asbestos paper is
carefully wrapped around the pipe, then an air space of about
one inch is provided by centering the pipe within a heavy
wooden-stave pipe casing. This casing is lightly banded with
steel wire and painted with heavy tar paint. The interior is
lined with bright tin to reflect radiated heat from the iron
pipe, and between the tin and the wood is a sheet of asbestos
to prevent charring of the casing. Expansion and contrac-
tion are taken care of by special joints known as variators,
placed about every 50 ft. along the street trenches. The
right-angled house service connections are taken off at the
anchored point where needed.
To Ca^lcuslsitl© thx<s Inloirsejpoweir
The table gives the horsepower generated by one cubic
foot of water per second (7.48 gallons) falling a distance of
one foot, which is 0.0965 horsepower, or 72 watts, and is the
basis upon which the following table was calculated.
Hi'KSEPOWER GENERATED BY ONE CUBIC FOOT PER SECOND,
FAILING DISTANCE 5 TO 200 FT.
lip of 1
Hp. of 1
Fall or
Cu.Ft. or
Fall or
Cu.Ft. or
-I.-ad ii
40 In
Head in
40 In.
It
Water
Kilowatts
Ft.
Water
Kilowatts
5
ii 183
0.360
35
3.380
2.521
6
0.579
0 431
40
:; win
2 s70
7
ii 676
0 504
45
4 340
3 237
8
(l 772
0 575
50
4 820
3 595
9
0.869
0 648
55
5.310
3 961
10
5
It 71S
60
;, , 'in
4 319
11
1 06 ■
ii 792
65
6 270
4 677
12
1.159
0 865
70
ii 7i.ii
5 042—5 k
13
1.255
II 'XV.
75
7.240
5.401
14
1 . 352
1.008—1 kw.
80
7.720
5 759
15
1 448
1.080
85
8.210
6 124
16
1 545
1 152
90
8 liOII
6.482
17
1 642
1 225
95
9.170
6.840
IS
1 738
1 296
100
9.650
7.19S
19
1 835
1.368
125
12 070
9.004—9 k
20
1.932
1 441
150
14.48
10 . S02
25
2.410
1.797
175
111 no
12.607
30
2.890
2 S90
200
19 31
14.405
Equivalents from this table may be converted to suit any
case by multiplying the horsepower of 1 cu.ft. of water under
any head by the head in feet times the number of cubic feet
per second of water available.
For determining the flow of a stream, or the amount of
water available for power purposes, the water is measured by
means of a weir — an instrument quite well-known in all of
the irrigating districts. A small weir table is appended.
TABLE FOR WEIR ONE FOOT IN LENGTH
Quantity in
Depth in Cu.Ft. per
In. on Sec. fol Each In M
Crest Ft. in Length Ii
1 ii 08 3
1* 0.15 6
2 0.23 9
2\ 0 30 12
3 0 I" 16
3! 0.50 20
4 0 65 26 10 2 55 102
4J ll 77 31 10| 2 75 110
5 0 90 36 11 2.93 117
1 hi 42 11'. 3 15 126
.; 1 18 47 12 3 35 184
6) 1.34 54
Quantity in
Cu.Ft. per
th in In
. Sec. for Each
- Ciest
Ft. in length
7
1.50
7*
1 66
8
1.81
s*
2.00
9
2. IS
9J
2 35
10
2 55
10|
2 75
11
2 93
This* table was calculated for depths of
to twelve incites by one-half inch increments
width of one foot.
\-ater from one
and for a weir
Tlk© C©@& of Effimplosniimgf
Imic©Effii-p©&©imis
At a recent gathering of machine tool builders it was
stated that it costs $30 to $35 to engage a workman, test him
and discharge him if inefficient. This figure is based on the
records of a large manufacturing plant, and it is easy to see
how much can be lost per annum if great care is not exer-
cised in selecting the new hands. It is even more nee
to be careful in putting new men on a power-plant staff, since
an incompetent man may cause damage running into thous-
ands of dollars in a very short time. The quality of the work
done by a mechanic or machine operative can be very quickly
gaged, but it is not so easy to estimate the abilities of a
shift engineer unless he blunders right at the start. A keen
chief will, of course, get to know the caliber of his man before
very long, but an emergency may occur, and the mischief may
be done before the discovery of incompetence has been made.
Heat Generated in n Circuit represents work done in over-
coming the resistance of the circuit.
May 25, 1915
P 0 W E R
727
Am&siaoiiaaa a Heaft Velhacle
By Albert Johnson
[The following paper by Albert Johnson, of the Herf
& Frerichs Chemical Co., was firsl read before the Amer-
ican Meat Packers' Association, Chicago, and since then
has been read before other like organizations. The ex-
planations and presentation will commend it to those
new at operating refrigerating equipment. — Editor.]
HOW AMMONIA CONVEYS HEAT
Let us see how anhydrous ammonia becomes a conveyor of
heat. When one pound of anhydrous ammonia has passed
through the regulating valve into the low-pressure pipes it
remains a liquid until it can grab hold of from 500 to 600
B.t.u. of heat. Then the pound of liquid changes into a
pound of gas. But it refuses to change from liquid to gas
until that much heat leaves the room and enters the liquid
ammonia on the inside of the coils, thereby turning it into gas.
The changing of the liquid into gas is what absorbs the
heat. Therefore, it is always necessary to have plenty of
liquid ammonia w'ithin the low'-pressure pipes.
Do not, under any circumstances, allow gas to pass through
the regulating valve, for then you only add heat to your
rooms instead of subtracting it. Remember, the gas is the
loaded vehicle, while the liquid is the unloaded vehicle, being
• tnpty. The liquid has plenty of room for heat units, but
the gas has little room for beat units, since it is already
loaded with them. It cannot carry any more. So it is well
to watch and see that only liquid passes the regulating valve
into the low-pressure pipes.
This is a more serious question in operation than you
may think possible, and the subject is more fully covered in
my former paper read before the International Congress of
Refrigeration, and entitled "The Value of a Liquid Seal," which
can be had upon application, free of charge.
Bear in mind that it requires heat to vaporize ammonia —
the more heat, the quicker the evaporation; whereas, the less
the heat, the slower the evaporation, which explains why
"sharp freezers" are so apt to fill up with liquid in abundance,
while the rest of the system may be suffering from the lack
of liquid.
After the liquid has been changed into vapor by the heat,
it has practically spent its energy as a refrigerant, for the
gas has obtained its full load of heat and is ready to carry
it away.
USE OF THE REFRIGERATING MACHINE
So far the ammonia, or vehicle, has been "running down
hill," requiring no power. At the bottom of the hill is the
loading platform where the heat is taken aboard. After this
il*s an uphill pull, and a good strong horse is required to
pull it up to the unloading platform. The horse may be
called a "refrigerating machine."
The machine gets behind the heat-laden gases in the
frosted low-pressure pipes and pushes them up to the top of
the hill to the unloading platform, or ammonia condenser,
where the loaded gas is changed back into a liquid. Just at
the moment when the gas becomes a liquid it releases or
dumps out the heat that it formerly picked up in the rooms,
and the water in the condenser then absorbs the released
heat units and carries them away.
Thus we see how necessary is the refrigerating machine
to push the loaded vehicle, ammonia, along the uphill grade
of high pressures direct to the top, or unloading place, at the
condenser. But that is all it has to do, for the real work of
freezing is performed by the ammonia, not by the machine.
The initial as well as the final operation is done by the
vehicle called ammonia, which must not be forgotten.
Thus you can readily see how anhydrous ammonia actually
becomes a so-called vehicle for removing heat units from
insulated rooms and carrying them, with the aid of the
refrigerating machine, upstairs or downstairs, around corners
and angles to condensers, there to unload its heat. Then
it goes back to repeat the operation.
WRONG NAME FOR A VALVE CAUSED TROUBLE
A regulating valve controls the flow of liquid ammonia
into the low-pressure pipes. That is all it is there to do.
It cannot do any freezing, since only the ammonia does that.
I mention this because, way back in the early days of this
industry, somebody misnamed that valve — the expansion valve
■ — without thinking of the consequences.
Ever since then many operators got the erroneous idea that
this valve actually did the heavy work of freezing, and they
would fondle it and handle it, fuss over it and play with it,
sometimes resetting it twenty times a day, then listening to
hear the gas gurgle ", spit through it. The misnaming of
this valve has cost the owners of plants hundreds of thou-
sands of dollars in time lost fooling with it and in lack of
ency caused by relying on this valve during eril
moments of climbing temperatures, when the receiver should
be watched instead. It is best to call it a regulating valve,
to save confusion of ideas, much money and false impressions.
When I speak of heat-laden gases in suction pipes it may
e you. Try to put your hand on a frost-covered suction
line and imagine it contains real heat. It actually does, and
lots of it, only it is called latent heat, or insensible heat. A
thi rmometer cannot register it, nor can you feel it by touch.
But it is there just the same. Apparently, the pipe is
cold, for it is usually covered with frost, yet the cold gas
inside of that pipe will deliver heat enough to warm up
enormous quantities of condensing water from 10 deg. to 30
dog. F. per pound.
We learn how the vehicle ammonia is relied upon to take
the initiative in the work of removing heat. It is essential
to work with not only dry, but pure ammonia. Note the
difference between dryness and purity, for volatile hydro-
carbons may exist in the liquid itself, which cause abnormally
high pressures. Such foul gases refuse to liquefy and they
fill up the condensers.
These bad gases must be blown away. Hydro-carbon gases
are both colorless and odorless, which makes them hard to
find. They are hidden, and like latent heat we know them
by the effect they produce when they refuse to liquefy, causing
excessive fuel bills or power bills and great ammonia con-
sumption.
It has been estimated that in order to purge 15 lb. of
uncondensable or hydrocarbon gas from the system you lose
85 lb. of pure gas, because the two are closely associated or
intermingled, so that when the purge valve is opened the
good as well as the bad gases are liberated unavoidably
together.
GOOD AMMONIA REQUIRES NO PURGING
Good ammonia requires no purging, for good ammonia is
free from volatile hydro-carbons. The evaporation test does
not disclose the presence of volatile carbon compounds, for
they evaporate together with the ammonia. The working
test seems to be the most reliable. The test for air in ship-
ping cylinders means little as to quality and has the disad-
vantage of being deceptive.
Ammonia is like fullers' earth, because both require a
working test to prove their effectiveness. In both cases
results count more than analysis. A chemical report on
fullers' earth is about as valuable as a chemical report on
anhydrous ammonia. However, in making an exhaustive ex-
amination of ammonia a thorough chemist will demand to
see the raw material as well as the finished product. In test-
ing cement, for instance, a thorough chemist will also examine
the clinker or raw material as well, in order to obtain data
for proper valuation. The clinker may be overburnt or under-
burnt, and the chemist is right in demanding a sample of the
raw material.
The purchase of anhydrous ammonia should be like the
hiring of a man. You expect a man to perform some service
and keep on doing so. In purchasing ammonia you must
expect it to serve you by picking up or absorbing all the
heat units possible and unloading them in large quantities
day by day, without getting tired or worn out on the slightest
occasion. Remember, you do not buy ammonia like other
merchandise, to be sold to others from the shelf. Instead
of that, you invest your money in an article that must work
for you day and night, and produce results in heat-carrying
capacity. For, to produce one ton of refrigerating duty the
vehicle, ammonia, must fetch and carry away 2S8.000 B.t.u. of
heat from insulated rooms in the shortest time possible, and
that is why the question of ammonia as a heat vehicle is so
serious as to affect the profits in a refrigerating plant.
e aft Ottawa
Electricity for cooking at a price equal to 50c. gas is what
Controller Ellis, of the Ottawa Municipal Electric Department,
has attained for the city. The present price of gas is $1.25
per thousand cubic feet, less 12 per cent, discount, plus a $2
a year meter rental, or about a net rate of $1.20 per thousand
cubic feet.
The annual report of the municipal electric department for
1914 pointed out the reduction in rates since the hydro-elec-
tric installation was first made. At that time the rate was
8c. per kw.-hr., less 10 per cent, discount, with no floor-area
charge; whereas now the rate is 2c. net per kw.-hr., and 3V4c.
per 100 sq.ft., less 20 per cent, discount, for floor space, and lc.
net for excess current used other than for lighting.
728
POWER
Vol. 41, No. 21
i^.siffies'icsiHa A.ss©ca^aoKa <oi
K.etts'ag.
The annual meeting of the American Association of Re-
frigeration was held in the Hotel Astor, New York City, May
11 and 12. Inasmuch as the association interests itself more
in the commercial application of refrigeration than in its
technical and engineering side, operating engineers have little
to gain from a knowledge of its activities other than to get a
broad perspective of the state and advance of the applica-
tion of refrigeration. To be sure, this is important and it is
from this angle that the operating engineer should watch
what the association is doing.
The meeting consisted chiefly of three business sessions
and a banquet. As President Frank A. Home, of New York
City, was not present at the first session, Past-President
Homer McDaniel, of Cleveland, opened the meeting.
In his address Mr. Home approved the recommendation
of the commission on legislation and administration that the
man of the testing committee, were last year's officers re-
elected: President, Frank A. Home; vice-president, E. O. Mc-
Cormick, Thomas Shipley, Homer McDaniel, Col. Jacob Rup-
pert, Jr., James Craig, Jr., Roderick H. Tait, R. H. Switzler;
secretary, J. F. Nickerson; treasurer, John S. Field; chairman
of Executive Committee, William J. Rushton; chairman of Ad-
visory Committee, H. W. Bahrenburg; chairman of Committee
on Papers and Lectures, Dr. F. W. Frerichs: chairman of Fi-
nance Committee, Theo. O. Vilter; chairman of Committee on
Trade Extensions, Dr. H. Dannenbaum; chairman of Commit-
tee on State and National Investigations, Dr. Mary E. Pen-
nington; chairman of Board of Engineers on Educational
Work, Gardner T. Voorhees; chairman of Commission on
Gases and Units, Prof. Edward T. Miller; chairman of Com-
mission on Testing Refrigerating Machinery and Insulating
Materials, J. H. Bracken; chairman of Commission on Ap-
plication of Refrigeration to Foods, G. Harold Powell; chair-
man of Commission on Industrial Refrigeration. Peter Neff;
chairman of Commission on Railway and Steamship Refriger-
Banqttet of the American Association of Refrigeration, Hotel Astor
association authorize the engagement of a reporting agency
to keep the association in the closest possible touch with
proposed legislation — local, state and national — affecting the
refrigerating industry. Mr. Home also recommended the en-
gagement of a paid manager, who, working under the secre-
tary, would devote his whole time to the affairs of the or-
ganization. That the president feels the need of more vigor-
ous, extensive and complete committee work was evident
from the manner in which he explained the need and value of
committee reports.
Dr. H. Dannenbaum, chairman of the committee on trade
extensions, in his report stated that the reports of the De-
partment of Commerce show that the value of ice and re-
frigerating machinery exported from the United States in the
fiscal year ending June 30, 1914, was $978,457. Of this,
Europe's purchases amounted to $34,SS3; North America's
$271, S43; Asia's, $100,010; South America's, $428,266; Oceania's,
$13S,091; and Africa's, $5364.
The Commission on Legislation and Administration re-
quested Dr. Pennington and Dr. Barnard and Mr. Coe to draft
a Federal storage law to be similar to the uniform cold-
storage law already drafted.
The banquet, held in the College Room of the Hotel Astor.
was enjoyable, and among the speakers were Borough-Pres-
ident Marcus M. Marks; Dr. Mary Pennington, chief of the
food research laboratory of the Bureau of Chemistry and
chairman of the association's committee on state and na-
tional investigations; G. Harold Powell, general manager of
the California Fruit Growers' Exchange; and Homer Mc-
Drniel, a past-president of the American Warehouseman's
Association.
All the officers, with the exception of J. H. Bracken, chair-
ation, Carl Howe; chairman of Commission on Legislation and
Administration, E. O. Whitford; chairman of Publication
Committee, N. H. Hiller; chairman of Committee on Mem-
bership, Bruce Dodson; chairman of Press Committee, E. D.
Ansley.
To Cailcaalai^© Sft©g\.sim IFLeq^airedl
to ©pes^te P^mmp
For a direct-acting pump in fair condition, operated at a
piston speed of 100 ft. per min., assume an average steam,
consumption per indicated horsepower-hour of, say 150 lb. dry
saturated steam, which is a so-called "water-rate" of 150 -f-
60 = 2.5 lb. i.hp.-min.; and multiply this water rate by the
indicated horsepower of the pump, as shown by the following:
Find the steam required to pump 9000 gal. of water per
hour, from a shaft 450 ft. deep, using a simple direct, double-
acting pump running at a speed of 100 ft. per min. and dis-
charging through a 3-in. column pipe.
The effective head, in this case, is
h, = 450
/9000\2
+ \ 60 )
4. ',11
)0 X 3'
= say 502 ft.
The indicated horsepower of this pump will then be
H = 0.00034 X 150 X 502 = 25.6 lip.
The weight of steam required to operate this pump, under
the assumed conditions, will be
Steam consumption,
2.5 X 25.6 = 64 lb. per min.
— "Coal Age "
May
1 9 1 5
POWER
m
Digested by A. L. H. STREET
Rights of Water Consumers — A water company which shut
off water from a customer's hydraulic elevator on the latter'S
refusal to paj an excessive bill, is liable for resulting damages
sustained by the customer, regardless of whether the error
in the bill was innocent or deliberate, according to the
decision reached by the Court of Appeals of Kentucky in
the late case of Louisville Tobacco Warehouse Co. vs. Louis-
ville Water Co., 172 "Southwestern Reporter," 928. The court,
however, upholds the right of a water company to make any
reasonable regulations tor the conduct of the company's
business, including the cutting off of service for nonpayment
of just charges which have accrued. But all regulations must
apply to all persons similarly situated.
Duty to Install Lightning Arresters — An owner of an elec-
trically propelled passenger elevator is liable for injury result-
ing to the operator from shock caused by lightning, if the ac-
cident be attributable to the owner's failure to install light-
ning arresters, according to the holding of the Springfield, Mo.,
Court of Appeals, in the case of Melcher vs. Freehold Invest-
ment Co., 174 "Southwestern Reporter," 455. Speaking of the
measure of care to avoid injury resulting from use of elec-
tricity as power, the court declares that ordinary care requires
the exercise of the highest diligence to take precautions
against accidents, by installing such safety appliances as
are reasonably available. And the decision adds that, since
lightning arresters are well-known devices, an owner of an
elevator who fails to install one cannot avoid liability for
accidents of the kind mentioned by showing that other per-
sons owning similar buildings have not installed them.
Suit for Flowage of State Lands — Suit was brought by the
State of Minnesota against the Minnesota & Ontario Power
Co., for $200,000 damages claimed to have resulted from
flowage of M0. noo acres of state lands along the international
border in the maintenance of the company's power dam
across the Rainy River. The company, in addition to operat-
ing large pulp and paper mills in northern Minnesota, supplies
electric light and power to various industries and municipal-
ities. The state threatened another similar suit against the
same company on account of prospective flooding of 50,000
more acres of public land near Kettle Falls on the same river,
where the company is constructing another power dam. The
suit brought, by omitting to claim any right to enjoin opera-
tion of the dam, recognizes the validity of the right granted
to the company by the United States and Canada to maintain
the dam.
Liability for Explosion of Boiler — An employer may be
held responsible for injury to an employee, caused by explo-
sion of a defective boiler after the making of repairs thereon,
on the theory of negligence in failing to apply the hydrostatic
test to the boiler, if that would have disclosed the defect.
This is the holding of the Court of Civil Appeals of Texas,
lately announced in the case of Ligarde vs. National Railway
of Mexico, 17:.' "Southwestern Reporter" 1140, in which the
plaintiff was awarded a verdict for $20,000, which the Court
of Civil Appeals declares was not excessive, for injuries sus-
tained by plaintiff in an explosion of a locomotive boiler in
repair shops. The following statement of the court, bearing
on the duty of inspection, would seem to apply to all classes
of steam boilers:
The engine was old, was in the shop for repairs, and it
was the duty of anpellant to apply all tests necessary to
ascertain how much steam the boiler would sustain. The
only perfect test was the hydrostatic, and the jury was
wairanted in finding that the railroad company was negligent
in not applying that test.
Contributory Negligence of Engineer — A stationary engi-
neer, who, being thoroughly familiar with the working condi-
tions of machinery, fails to take proper steps to stop the
machinery before placing his hands in a dangerous position,
in making repairs, cannot recover against his employer for
bonsequent injury, even though there may have been insuffi-
cient light in his place of work. This is the gist of the
decision of the Supreme Court of Wisconsin, announced in the
case of Hansen vs. Campbell Laundry Co., 151 "Northwestern
Reporter," 262. The plaintiff was the engineer in the de-
fendant's plant and found it necessary to tighten some nuts
in the mechanism of a pair of automatic underfeed stokers.
Instead of shutting off the steam by using one of the three
valves, which he knew would absolutely close off the steam,
he turned a dial point to zero, and supposing that would stop
the machinery, reached his hand into a steel case containing
movable mechanism. There was sufficient escape of steam
past a regulating valve to cause the machinery to move, and
his hand was injured in consequence. He brought suit to
recover for his injuries, but the Supreme Court holds that
the trial judge properly denied recovery on the ground of
contributory negligence. The Supreme Court attributes care-
lessness to the plaintiff in failing to use the valves, as
affording the only safe means of stopping the machinery, and
finds that any insufficiency in lighting of the premises did
not contribute to the accident by preventing the plaintiff
from using the valves, or by ascertaining whether the dial
point was at zero.
C. E. Lesher, associate geologist of the land-classification
board of the United States Geological Survey, has taken
charge of the work of compiling the statistics of coal produc-
tion published in the annual volume "Mineral Resources."
This work has heretofore been directly under Edward W.
Parker, whose resignation from the Geological Survey is ef-
fective July 1.
A. O. S. E. Convention — The American Order of Steam En-
gineers will hold its twenty-ninth annual convention at At-
lantic City, N. J., during the week commencing June 21. The
local convention committee, assisted by the officers of the
American Supplymen's Association, are hard at work com-
pleting the final arrangements. The Continental Hotel on
Tennessee Avenue has been selected as the headquarters, and
the elaborate mechanical exhibit will be located at the Morris
Guards Hall, on New York Avenue.
A. S. M, E. Spring Meeting — The spring meeting of the
American Society of Mechanical Engineers is to be held at
Buffalo, N. T., June 22 to 25. The society has met at Niagara
Falls before, but. this will be the first time at Buffalo. David
Bell is chairman of the local committee of arrangements;
James W. Gibney, vice-chairman; C. A. Booth, secretary, and
C. H. Bierbaum, treasurer. The Engineering Society of Buf-
falo is to join with the local A. S. M. E. members and engi-
neers generally in acting as hosts. The headquarters will be
at the Hotel Statler, where all sessions will be held except
the first one, which will be at Niagara Falls in the large
auditorium of the Shredded Wheat Biscuit Co. The papers to
be presented include "Laps and Lapping." by W. A. Knight
and A. A. Case; "Model Experiments and the Forms of Em-
pirical Equations," by E. Buckingham; "Rational Design and
Analysis of Heat Transfer Apparatus," by E. E. Wilson;
"Influence of Disk Friction on Turbine-Pump Design," by F.
zur Nedden; "A Study of an Axle Shaft for a Motor Truck,"
by John Younger; "Corrugated Furnaces for Vertical Fire-
Tube Boilers," by F. W. Dean; "The Effect of Relative Hu-
midity on an Oak-Tanned Leather Belt," by William W. Bird
and Francis W. Roys; "The Relation between Production and
Costs," by H. L. Gantt; "Design of Rectangular Concrete
Beams," by Howard Harding; "Some Mechanical Features of
the Hydration of Portland Cement and the Making of Con-
crete as Revealed by Microscopic Study," by Nathan C. John-
son; and "Surface Condensers," by Carl F. Braun.
Chicago A. S. M. E. Discusses the Electric Locomotive —
Friday evening. May 14, was the last meeting of the season
for the Chicago1 Section of the American Society of Mechanical
Engineers. As usual, the meeting was an informal dinner
session in the 1 1 •- ■ 1 Room of the Hotel La Salle. At a prelim-
inary business meeting the following officers were selected
for the following year: H. M. Montgomery, chairman; Joseph
Harrington, vice-chairman; Robert H. Thayer, secretary;
other members of the committee, Charles E. Wilson and H. T.
Bentley. The subject for the evening was the "Electric Loco-
motive." It was a timely topic for Chicago and a goodly num-
ber of the engineers took advantage of the opportunity to
learn what has been done and what is being done in this
field. A. F. Batchelder, chief engineer of the locomotive de-
partment, and A. H. Armstrong, assistant engineer of the rail-
way and traction department, both of the General Electric
Co., gave talks of exceptional interest on the subject. The
former confined himself to the design and by means of numer-
ous lantern slides traced the development from, the first
locomotive installed by the Baltimore & Ohio R.R. Co. In
1895 to the recent combination passenger and freight locomo-
730
l'OWER
Vol. 41, No. 21
tives for the mountain divisions of the Chicago, Milwaukee
& St. Paul Ry, The designs of truck, control arrangement,
type of motor and other interesting features were illustrated
in the numerous slides presented. Mr. Armstrong centered his
talk on where the locomotive is used, the excuse for its ex-
istence and a comparison with the steam locomotive. He
dwelt particularly on the Butte, Anaconda & Pacific 2400-volt
direct-current locomotives, those of the New York Central and
the immense machines recently built for the Chicago, Mil-
waukee & St. Paul Ry. Data on tractive effort, weight on
drivers, efficiencies and limitations were given, and upon re-
quest were followed by an interesting summary on the devel-
opment of current collectors. Both talks were highly appre-
ciated by the audience, and no doubt valuable information
was absorbed, which may help in the solution of one of
Chicago's knotty problems — the electrification of its steam
railways.
The National Association of Manufacturers will hold its
20th annual convention at the Waldorf-Astoria Hotel, New
York City, May 25 and 26. Among those scheduled to address
the convention are ex-President Taft, whose subject will be
the "Clayton Act and Other Things;" Senator Warren G. Hard-
ing, of Ohio; Dr. Eugene L. Fisk, M. W. Alexander and Arthur
D. Little. James A. Emery will outline the work of the newly
created Federal Trade Commission. Walter Drew, of the Na-
tional Erectors' Association, will discuss the work of the
Federal Commission on Industrial Relations. Committees will
report on fire and accident prevention, union label, immigra-
tion, uniform state laws, trademarks and copyrights, and in-
dustrial betterment. Incidental to the convention will be a
unique exhibition devoted to various phases of industrial
education with students actually at work in various lines of
industries. In this will be included exhibits from New York
City; Newark, N. J.: Fitchburg, Mass.; New Haven, Conn.;
Altoona, Penn.; Detroit, Mich., and other places where well-
known trade schools are established.
i©01§ RECEIVED
MEW EQUIPMENT
VALVES AND VALVE GEARS. Volume I. By F. D. Fur-
man. John Wiley & Sons, inc., New York. Cloth; 253
pages, 6x9% in.; 300 illustrations. Price, $2.50.
POWER HEATING AND VENTILATION. Part III. By
Charles L. Hubbard. McGraw-Hill Book Co.. New York.
Cloth; 408 pages, 6x9% in.; 220 illustrations; tables.
Price $3.
THE "PRACTICAL ENGINEER" POCKETBOOK AND DIARY
FOR 1915. Distributed by the Magnolia Metal Co., New
York. Cloth; 632 pages; 3%x5 in.; numerous illustrations
and tables.
Kerr Turbine Co., Wellsville, N. Y. — Bulletin No. 52. Econ-
omy turbo-pumps. Illustrated, 24 pp., 6x9 in.
Cresson-Morris Co.. Philadelphia. Penn. Form No. 1001.
Barometric condensers. Illustrated, 28 pp., 9x12 in.
The Richardson-rhenix Co., Milwaukee, Wis. Bulletin
No. 40, Phenix oil and graphite cylinder lubricator. Illus-
trated, 4 pp., 8^x11 in.
The Draper Mfg. Co., Port Huron. Mich. Catalog No. 7.
Valve facing tools, ball check valves, brass, iron and steel
balls, pneumatic flue welders, pneumatic tube welders, etc.
Illustrated, 40 pp., 6x9 in.
Negotiations were recently closed for the sale of the Cleve-
land Clutch Co. to the Reliance Gauge & Column Co., 5902-5912
Carnegie Ave., Cleveland, Ohio.
The contract for furnishing material under circular No.
891 for complete pumping plant for Dry Dock No. 1, Balboa
Terminals, Balboa, C. Z., was awarded by the Panama Com-
mission to Henry R. Worthington, 115 Broadway. New York.
August Mietz. 12S Mott St., New York, has recently secured
orders for Mietz & Weiss oil engines from the Grinden Art
Metal Co., of Brooklyn. N. Y. (2); the Town of Schleswig. Iowa
(2); I. H. Pitts & Son, Waverly Hall. Ga.; Marcus Mason &
Co., South Framingham, Mass.; George Buckley, Menlo, Iowa;
U. S. Government, for lightships Nos. 101 and 102 (two 200-hp.
direct reversible marine-type oil engines and four 50-hp. oil-
engine air-compressor outfits).
ATLANTIC COAST STATES
The Cambridge Electric Light Co., Cambridge, Mass., has
made application to the Board of Gas and Electric Light Com-
missioners for authority to issue $100,000 in additional capital
stock, a part of which will be used for making additions to
the system. W. E. Holmes, Newton, is Treas. and Gen. Mgr.
The Hudson Ice Co., 136 Oakland St., Jersey City, N. J.,
is preparing to build a 100-ton ice plant at Central and
Jefferson Ave., Jersey City. S. H. McKnight is Pres.
It is reported that the Council has engaged W. S. Temple,
Philadelphia, i'etin., to prepare plans for the construction of
a municipal electric-lighting system for Millville, N. J.
It is reported that the Town Council of Patton, Penn., is
considering the establishment of a municipal electric-light
plant. Service is now furnished by the Penn Central Light
& Power Co., Altoona.
SOUTHERN STATES
It is reported that the Planters Oil Mill & Gin Co.,
Kosciusko, Miss., is in the market for additional power equip-
ment and boilers.
The City of Oberlin, La., has appointed a special committee
to engage an engineer to prepare plans for the construction
of a municipal electric-light plant. W. D. Stockwell, Mayor,
is Chn. of the Com.
CENTRAL STATES
The municipal electric-light plant at Ashley, Ind., was
destroyed by file recently at a loss of $4000. George W. Caryl
is Mgr.
At a recent election in Chalmers, Ind., the citizens voted
in favor of installing an electric-lighting system. It is
reported that the plant will be constructed by a stock com-
pany, and will eventually be purchased by the town. T. C.
Smith, Chalmers, is Engr.
The City Council, Lanark, 111., is considering the establish-
ment of a municipal electric-light plant.
It is reported that the Board of Public Works, Oshkosh,
Wis., has been instructed to advertise for bids for a dynamo
and connections for an independent lighting system for the
new high school in Oshkosh.
WEST OF THE MISSISSIPPI
It is reported that the Iowa River Light & Power Co.,
Eldora, Iowa, contemplates spending about $50,000 for im-
provements to its system. A new power station will be built,
and the output of the steam plant increased. J. C. Lundy is
Mgr. and Cont. Agt.
The city of Shellsburg, Iowa is considering the question
of establishing a municipal electric-lighting system. The
estimated cost is $10,000. It is reported that the Cass Inter-
urban Co. has also made an offer to build a transmission
line from Urbana to furnish electrical service to Shellsburg.
The town of Marietta, Minn, is considering the question
of establishing a municipal electric-lighting system.
The citizens of Kirwin, Kan., have voted in favor of a bond
issue of $12,000 to be used for the installation of a municipal
electric-light plant.
The town of Corder, Mo. has appropriated $6000 for the
purpose of buying light and power equipment.
The city of Poplar Bluff, Mo., has voted $75,000 in bonds
for the purpose of establishing a municipal electric-light
plant. Contracts for the installation of the plant have been
awarded.
L. B. Myers, El Reno, Okla., and associates, will establish,
according to press reports, an electric-light and power plant
and ice factory at North Pleasanton, Tex. The estimated
cost is $40,000.
It is reported that the city of Seguin, Tex., will make
improvements and extensions to the municipal light and power
plant to include the construction of a new building and pen-
stocks, the installation of a 187-kw., three-phase, 60-cycle,
2300-volt, waterwheel type generator, exciter and switch-
boards, two 150-hp. vertical waterwheels and transmission
machinery. Owen A. Gofford is Mgr., Cont. Agt. and Supt.
of the plant.
It is reported that Morris Sass, Ardmore, Okla., is in the
market for power equipment, including a gasoline engine.
It is reported that the City Council of Reno, Nev., is
considering a bond issue of $750,000 to be used for the con-
struction of a municipal electric-light plant and water-works
system. J. R. Parry is City Clk.
Bids will be received until May 28 by R. W. Davis, Mayor,
Harrisburg, Ore., for one 35-hp. motor of 900 to 1300 r.p.m..
one 25-hp. motor, 900 to 1200 r.p.m., and one 5-hp. motor of
about 1500 r.p.m.
The City Trustees of Escondido, Calif., have decided to
call a special election to vote on the question of a bond
issue to be used for purchasing the property of the Escondido
Utilities Co.
CANADA
It is reported that the city of Sherbrooke, Que., will pur-
chase electric meters, controllers, etc., to the amount of about
$27,000. W. E. C. Gatien is City Clk. No bids will be asked.
The Canadian Niagara Power Co., Niagara Falls, Ont.,
contemplates making extensive improvements in its plant.
Philip P. Barton, Niagara Falls, is Gen. Mgr.
The City Council of Kelowna, B. G, is considering the
establishment of a municipal electric-light plant, estimated
to cost $120,000. It is reported that a bylaw will shortlv be
submitted to the rate-payers.
POWER
NEW YORK, JUNE 1, 1915
No. 22
The Salesmen's Reply
By Willi \m A. Dunelet
An answer to "The Troubles of the Manager,"
in the March 30 issue.
■>.\\\li/,/
We get our hat times here
•m Earth, then climb the
"gold* n alair."
THE MANAGER'S a grouchy cuss, although
he has it soft
And lounges in an easy chair and wears out
good broadcloth
He has his car, he has his golf ; these joys cannot allay
The grouch that grips his vitals when we boys come
his way.
Outside his door an office boy confronts us with a
frown
And says, "Come back some other time, the 'Old
Man's out of town'
And if at last we pass the door and beard, him in his
lair.
He acts as though "Old Nick" himself would be
more welcome there.
He sits and smokes our good cheroots (We buy them
three for five),
And he is game to buy our goods in case he can
survive.
We show him how to save his dough and how to
spend it too.
He may have tried some other line, but ours is
"something new."
We're agents of prosperity and keep him up to date,
And any plant with-
out our goods
would meet a
sorry fate.
But when hi
O'ls t" Satan'i
1. 'In:, iril
find no
tale*
there.
Some time ago we met a chap who ran a power planfv
And every day he'd tear his hair, and cuss, and rave,
and rant.
Directors had him going right, the dividends were
slim,
And costs were soaring out of sight; looked like
"good night" for him.
His durned old plant was out of date, and leaks were
everywhere,
And here a groan and there a knock, were crying for
repair.
He wasn't wise to boiler scale, much less to C02
And half his good bituminous was wasting up the flue.
We talked to him until our throats were parched as
desert sand;
But "soda water" fixed us up (guess you will under-
stand).
And finally, he was convinced and purchased half
our line;
And now, that same old power plant is running
something fine.
We are the manager's best friends, we help him to
progress,
And steer him up the narrow path to honor and suc-
cess.
Andwhen atlast he shuffles off, beyond the milkyway.
We have a line of golden harps to make his future gay.
And if instead, he goes below in spite his good intent,
We'll lag him well with fireproof paint, asbestos and
cement.
But when he gets to Satan's realm, he'll find no
salesmen there;
We get our hot times here on Earth, then climb the
"golden stair."
.32
P 0 W E K
Vol. 11, No. 22
>wer Flaunt! ©f tllne
IKlectlrie Co,
r>v c. r. Laksen
SYNOPSIS — This power plant supplies electrical
energy for motor and lighting service and for o
ating the pumping plant. Exhaust steam is used
for district steam healing. Lignite containing
6590 B.f.u. per ' as a fail. Burning
42 lb. of coal per square foot of grate area. S lb.
of wafer is evaporated per square foot of boiler
heating surface.
The power house of the Hughes Electric Co. supplies
the town of Bismarck, N. D., with light, heat and power
and also pumps the water for the Bismarck "Water Supply
Co. The boiler room, Fig. !. contains four water-tube
boilers, each rated at 306 hp., having 3060 sq.ft. of
heating surface, and two return-tubular boilers, each
rated at L50 lip. The boilers are hand-fired, as no
sri'kci's arc known
for burning lig-
nite that will give
d results as
are obtained with
hand firing. Each
furnace of the
large boilers is
equipped with IS
sq.ft. of grate sur-
face, or one to
each 63.75 sq.ft.
of heating surface.
The grates used
are of the flat saw
dust type, perfo-
rated with half-
inch holes, which
give about 20 per
cent, air space.
This dues not con-
form with modern
practice for burn-
ing low-grade fuel,
as with an in-
creased grate sur-
face a boiler can be forced to a greater extent, but it
is a question if the combustion will be so complete with a
lignite fuel that is low in carbon and contains so much
volatile matter that must be taken care of to obtain effi-
ciency. With this ratio of grate to heating surface, -'5 lb.
of water is evaporated per square foot of heating surface
and 42 lb. of coal is burned per square foot of grate sur-
face.
Lignite burns much like dead wood or brown paper,
with a natural slow draft, and it can burn like a black-
smith's fire and give off very little heat. It will slack
and turn into dust, and when fired under a boiler in this
condition the design of grate is of importance, as with a
10 per cent, air space there is little chance for the fuel
to rest while it burns, for it is in continual motion, roll-
Fig. 1.
ing around and mixing with ashes, which results in a
flameles> fire. If the air pressure under the grates is in-
creased, holes will be blown in the fuel bed through which
air will pass freely and cool the furnace.
It is necessary to level off the bed of fire or fill the holes
with a fresh supply of coal, but if the fire is in bad shape
there is no remedy, and the only thing to do is to pull it
and start a new one. With less air space the fuel has a
chance to rest on the bridges between the holes and each
hole will form a little burning jet, as a higher air pres-
sure can be maintained under the grate. The greater the
velocity of the air through the holes, the greater the in-
crease in the temperature ; about 1900 deg. is obtained
and a flue-gas temperature of about 150 deg. F., with
an average of 12 per cent. C02.
There is a peculiarity in burning lignite coal as it
car be easily wasted owing to the amount of air required
for combustion.
The long flame.
with its low tem-
perature, carries
the unignited
gases through the
boilers and up the
smoke-stack and
produces a deceiv-
ing temperature
of flue gases. It
is possible to burn
60 lb. of coal per
square foot of
grate surface and
evaporate but 3 lb.
of water per
square foot of
heating surface
and have a flue-
eas temperature
of but 350 deg. F.
Then again, it is
possible to change
the air supply,
break the coal to
suitable sizes, burn 35 lb. of coal per square foot of grate
surface, evaporate the same amount of water per square
foot of heating surface and have a flue-gas temperature of
150 deg. F., a decrease in fuel consumption of 11 per cent.
An average evaporation of 1.5 lb. for a month's run is
obtained in many tests, and during short tests as high as
1.85 lb. of water per pound of coal has been evaporated;
the temperature of the feed water being 190 deg. F., steam
pressure 110 lb. and the coal containing 6590 B.t.u. This
is equal to an evaporation of 8.8 lb. of water from and at
212 deg. F. per pound of combustible and shows an effi-
ciency of about 7T per cent. These results are obtained
by using forced draft with a slow velocity, so that the
heat in passing through the boiler is absorbed by the water.
It is not advisable to force a boiler above its normal rat-
Boiler Boom of the HroHEs Electric Co.'s
Power Plant
June 1, 1915
eo \' :■: i;
73:3
ing. It is easy to lone the fires and send a flame out
at the top of a 50-ft. stack, but at the same time the boiler
is not generating steam in proportion to the fuel burnt.
It is not an easy matter to lay down a general rule fur
burning lignite. The coal burned at this plant is a low-
grade fuel containing about 6500 B.t.u., between 35 and
10 percent, moisture and from 5 to 10 per cent. ash. It
is not suitable for long shipments or storage in warm
wither, as it slacks, or pulverizes, like burnt lime when
it loses its moisture.
It is delivered to the power house in railway ears and
unloaded into a bucket conveyor about 150 ft. long, ex-
tern ling <>0 ft. outside of the building alongside the
railroad track. Two cars can be unloaded at the same
time. In the overhead run the conveyor is provided with
chutes for each boiler. Its capacity is 25 tons per hour
and it is driven by a 10-hp. motor. The cars on the side
track are moved by a car puller driven by a 5-hp. motor.
The cost of handling the coal from the cars into the
boiler room is 9c. per ton. The plant is 25 miles from
the mine and the coal, which runs in size from 6-in and
down to dust, costs $1.75 per ton delivered at the plant.
( Miiv in a while a car of slack is received, at $1.15 per ton.
which helps to bring the average price of the fuel down.
The boiler room
is 60x80 ft. and
Mil ft. high. There
are three steam-
driven boiler-feed
pumps, two vacu-,
tini pumps, one
a i r compressor,
one boiler-washing
pump and one
open feed-water
heater. The last
is merely a tank,
and as the conden-
sation from the
heating system
lias at times a
temperature of
165 deg. F., it is
found to he more
economical to turn
the exhaust from
the vacuum and
boiler-feed pump
into the heating
system when live steam is required. Otherwise, it heats
the feed water up to about 200 deg. P.
A 30-in. fan for forced draft is driven by a 15-hp.
motor. The air for this fan is taken from above the boil-
ers and as it passes through the combustion chamber to
the ashpit, it is warmed to some extent. The main boiler-
feed pump has an 8-in. suction pipe and a 6-in. discharge,
with 2.5-in. feed line to each boiler. The regulating valves
are conveniently located: the steam pipe from the boilers
to the 12-in. header is 6-in., equipped with automatic
stop valves. All pipes, fittings and valves are extra heavy.
The engine room, Fig. 2, is 30x115 ft. and 25 ft. high ;
it is neatly finished, and contains only the generating
units, exciter and switchboard. It has a terrazza floor
•with marble borders, and the side walls are wainscoted
5 ft. high with white enamel brick; the engine beds above
Fig. 2. General View of the Engine Room
the ll • line are painted silver gray; across one end of
the room is a. balcony, where the chief engineer has his
desk. A winding iron stairway leads to this balcony.
The engine room contains live units. The smallest is a
I2.\12-in. engine running 270 r.p.m., with a steam con-
sumption of 28 lb. per- i.hp.-hr., and is directly connected
lo a 75-kw., 230-volt, direct-current generator. Unit
No. 2 is a L6xl6-in. engine running 270 r.p.m., with a
steam consumption of 28 lb. per i.bp. br., and is directly
connected to a 1 00 kw., 230-volt, direct-current generator.
Unit No. 3 is a 20xl8-in. vertical engine running 200
r.p.m., with a steam consumption of 35 lb. per i.hp.-hr.
and is directly connected to a 200-kw., alternating-cur-
rent, 60-cycle, 2300-volt generator. Unit No. 4 is a
I 1 1 |,s'.'"i\ 18-in. cross-compound engine running 200
r.p.m., and uses 22 lb. of steam per i.hp.-hr.; it is directly
connected to a 250-kw., (10-cycle, 2300-volt alternating-
current generator. This unit has its exciter on the main
shaft. Unit No. 5, Fig. 3, recently installed, is a 23x30-
in. engine running at 150 r.p.m., and uses 23 lb. of steam
per i.hp.-hr.; it is directly connected to a 500-kw., 60-
cycle, 2300-volt, alternating-current generator. This
generator is excited by a 35-kw., 125-volt, direct-current
generator driven by a 50-hp. induction motor. Switches
are arranged so
that either unit
can he excited
from the 35-kw.
exciter. A motor-
driven exciter is
used for No. 3
unit, as the com-
p a n y furnishes
either direct or al-
ternating current
to its customers.
There is also a
100-kw. motor-
generator set, and
as this is usu-
ally generating di-
rect current the
] >ower factor in
the alternators is
increased by hav-
ing this synchron-
ous motor in the
c i r c u i t . The
switchboard has
fourteen marble panels and is equipped with voltage regu-
lator for the alternating-current circuit, circuit-breakers,
switches for the generators and transmission lilies, volt-
meters, ammeters and wattmeters, and synchronizing in-
dicator. In the engine room is a 30-kw. constant-current
transformer for city arc lights.
The plant has equipment sufficient to supply an ordi-
nary city of 20,000 inhabitants with electricity. Bis-
marck has a population of 1000 and about thirteen years
ago the company started an electric plant with a 50-kvv.
unit. The rapid growth of the city, however, has constant-
ly made demand for more units. The rate charged for
cooking service is 3.5c. per kw.-hr., for lighting service
it is LOc. to 1.2.5c, and for power service the rate is ac-
cording to the amount used, from 1.5c. u^i.
The company is operating the < ity pumping station lo-
,:;i
row E i;
Vol. 41, No. 22
rated on the banks of the Missouri River. The water flows
b\ gravity into a receiving well 12 l't. in diameter. Prom
there the water is pumped to three reservoirs on a hill
200 i't. above the river. Each reservoir holds about one
million gallons. A 13xl6-in. triple-plunger pump, bell
driven by a 100-bp. induction motor was recently in-
stalled. The speed of the motor is 450 r.p.m. with a 26-in.
diameter pulley; it is belted to a countershaft with a 70-
in. diameter pulley. 22-in. face. A "20-in. double-ply
leather belt is used, and the crankshaft is speeded down
to 34 r.p.m. by cut gears. The plungers have a displace-
ment of 935 gal. per min. and the water pumped is 926.5
gal. per min. This allows 8.5 gal. for slippage, or 0.9 per
cent.-. 46 kw. are recorded by the wattmeter at this load,
and as the theoretical kilowatt consumption for lifting
926.5 gal. to an elevation of 200 ft. is 34.8, this gives
a 6-in. connection to the feed-water beater, and a 12-in.
main to the beating system. The condensation is returned
to the healer by vacuum pumps. Central beating has
proved so satisfactory that the demand for steam has in-
creased more rapidly than the electrical output, and to
such an extent that in cold weather about 60 per cent,
of the total steam generated in the boilers passes through
a reducing valve to the heating system. The rate for steam
is 40c. per 1000 lh. All customers are charged on a meter
basis.
Condensation from the mains and branches is trapped
off where the pipe enters the customer's building. These
bleeders trap off aboul 20 per cent, of the steam output
from the boiler. In the L6-in. header is a 16-in. oil
and steam separator, from which the condensation trapped
off a tints to 12 per cent. The condensation from the
Fig. 3. The Latest Engine Installed Driving a 500-Kw. Alternating Generator
a combined efficiency of 75.7 per cent, for the motor and
pump.
There is pumped 1208 gal. per kw.-hr. to an elevation
of 200 ft., 13 ft. of this being suction lift. As the Nos.
4 and 5 units give the best steam efficiency, these are oper-
ated the most. With either, 8 lb. of lignite coal is
burned per kilowatt generated and put into circuit; this
includes steam Eor operating the boiler-feed pump and
the vacuum pump for the heating system; also current
for operating the forced-draft system, for the motor and
for the station lighting. In summing up the combined
efficiency of these units and the pump, it shows that one
pound of this low-grade lignite coal is elevating 151 gal.,
or 1258 lb., of water 200~ft.
A central heating system is also operated. The ex-
haust pipes from the engines are connected to a 16-in. ex-
haust header, which has a 12-in. outlet to the atmosphere,
high-pressure pipe line and receiver, steam separators and
exhaust from the boiler-feed pumps, enters the open feed-
water heater and amounts to about 4 per cent. The total
of those items amounts to 36 per cent, of steam generated
but not passing through meters. Those losses are not
constant, as the percentage lost is less in cold weather
with a greater steam consumption, though owing to these
condensations the company receives only 27c. per 1000
lb. of steam generated ; still, the output of steam for the
month of December, 1914, made a. favorable showing, as
9,844,000 lb. was recorded by the meters in the heating
system and 3.444,400 Jo. of coal was burnt during the
month, at a cost of -$5(186.32. or $1.56 per ton. As dur-
ing the winter months there are many sunshiny days with
a comfortable temperature, considerable exhaust steam
escapes to atmosphere during peak loads. This is a nat-
ural loss and cannot be controlled.
June 1, 1915
POWE R
735
No. Equipment
4 Boilers
2 Boilers
1 Blower
1 Motor
1 Coal conveyor..
1 Motor
1 Pump..
1 Pump..
1 Pump..
1 Pump..
2 Pumps.
PRINCIPAL EQUIPMENT OF THE HUGHES ELECTRIC COMPANY'S POWER PLANT
Kind Size
Franklin water-tube. . 306-hp
Return-tubular 150-hp
Sturtevant 30-in
Direct-current 15-hp
Bucket 2-~> tons per hour,
Dixect-euirent 9-hp. inclosed. . .
Outside-packed 14x9xl6-in.
Duplex 8xGxl2-in. .
Duplex 7x5xl0-in..
Duplex 5x3lxS-in..
Duplex 7x9xl0-in. .
1 Air compressor. . Locomotive type 9x9xl0-in..
1 Car mover
1 Motor
1 Engine. . . .
1 Generator. .
1 Engine. . . .
1 Generator.,
1 Engim
1 Generator..
Geared down to drum Two loaded cars.
Direct-current 5-hp. inclosed- . .
Simple horizontal 12xl2-in-i 125-
hp
Direct-current 75-kw.
Simple horizontal 16xl6-in., 160 hp,
Directrcinrent lCC-kw
Simple vertical 2Gxl84n.v 300 hp,
Alternating-current . . 200-kw
Steam generators. .
Steam generators. .
Forced draft
Driving blower ...
Car and elevt. coal.
Driving coal con-
veyor
Boiler feed
Boiler feed
Boiler feed
Boiler washing
Returns from heat-
ing system
Cleaning generat-
ors
Moving coal cars. .
Driving car mover
Generator drive. .
Light and power. .
Generator drive. , .
Light and power.
( reneratoi drive.. .
Light and power. .
1 Engine
1 Generator
1 Engine
1 Generator
1 Motor generator
1 Exciter
1 Motor
1 Exciter
1 Motor
1 Exciter...
1 Transformer
Cross-compound, hor-
izontal
Alternating-current. .
Simple Lentz
Alternating-cuirent .
Alternating- and di-
rect-current
Motor-driven
Induction
Motor-driven
Induction
On engine shaft. .
Constant-current .
141&25xlS-in.,
300 hp
250-kw
23x30-in., 750-hp.
500-kw
100-kw
35-kw., 125 v
50-hp
11-kw., 125 v
20-hp
80-amp., 125 i
30-kw., 2200 v
Operating Conditions Maker
Hand-fired, steam pressure, 140 lb Franklin Boiler Works Co.
Hand-fired, steam pressure, 130 lb Western Supply Co.
Motor-driven B. F. Sturtevant Co.
General Electric Co.
Motor-driven , Link-Belt Co.
Intermittent - General Electric Co.
140 lb. steam Union Steam Pump Co.
140 lb. steam . Dean Bros. Steam Pump Works
140 lb. steam Dean Bros. Steam Pump Works
140 lb. steam, as wanted Geo. F. Blake Manufacturing Co.
Winter months , Dean Bros. Steam Pump Works
Steam-driven Wesl inghi use Air Brake Co.
Motor-driven Link-Belt Co.
230 volts Geneial Electric Co.
140 lb. steam, 270 r.p.m _..«. American Engine & Electric Co.
270 r.p.m., 230 voits General Electric Co.
140 lb. steam, 270 r.p.m American Engine & Electric Co.
230 volts, 270 r.p.m. General Electric Co.
140 lb. steam, 200 r.p.m Bates Machine-Co.
60-cycle engine drive, 200 r.p.m., 3 phase, 60-
cycie General Electric Co.
Generator drive 140 lb. steam, 200 r.p.m Buckeye Engine Co.
Light and power . . Three-phase, 60 cycle, 200 r.p.m General Electric Co.
Generator drive.... 140 lb. steam, 150 r.p.m Erie City Iron Woika
Light and power.. . Three-phase, 60-cyck, 2300 volts, 150 r.p.m. L. General Electric Co.
Light and power. . Three-phase, 60-cycle, 2300 volts, 150 r.p.m\4N "General Electric Co.
Exciting generator Reversible General Electric Co.
Exciter drive Motor driven General Electric Co.
Exciting generator 60-cycle, 1200 r.p.m General Electric Co.
Exciter drive Motor-driven General Electric Co.
Exciting generator 60-cycle, 900 r.p.m General Electric Co.
Arc lights Engine-driven. General Electric Co.
During the heating season there is no consideration
given to an economical cutoff in the engine cylinder, as
with a 50 per cent, cutoff the terminal pressure is about
60 lb., and as this volume passes into the heating system
it gives a momentarily increased velocity ;J00 times a
minute, which is noticeable all through the system, and
for this reason good service has been given with as low
as 2.5 lb. pressure at the power house.
Simplex condensation meters are used in the system,
and steam traps are the standard traps in use where ad-
visable.
The output of electricity for the month of December,
1914, was 175,495 kw. Of this 25,000 was sent through
a 6600-volt transmission line to a railroad shop five miles
from the power house. This leaves 150,495 kw. for Bis-
marck with its 7000 inhabitants, or over 20 kw. for each
person per month.
8
Ceiate^i ©ales* ffos* VeirK&cgvl
Maintaining an adequate supply of oil on vertical crank-
pins has never been an easy problem, and when the pin
carries two or perhaps three bearings, as in the case of
angle-componnd-centrifugal pumping units, the difficul-
ties are increased.
As an easy solution to this problem Wm. W. Nugent
& Co., of Chicago, are offering the central crankpin oiler
shown in the accompanying illustration. It consists of
a horizontal oiler arm and a funnel to receive the supply
of oil. One end of the arm is secured to the crankpin by
a bolt, and the receiving end is centered over the vertical
shaft. It is evident that while the funnel revolves with
the crankpin there is no lateral movement, so that the fun-
nel will remain under the oil feed shown just above. De-
pending on the number of bearings on the crankpin, the
central arm has one, two or three compartments fed
through an equal number of concentric funnels.
• In the illustration shown the pin has three bearings for
the three connecting-rods of a triple-expansion engine.
As a consequence there are three compartments in the arm
and three funnels, one feeding to each compartment and
each compartment feeding a bearing through oil holes
Nugent Oiler for a Vertical Crankpin
bored in the crankpin. By means of the open feeds above
the funnels the supply of oil to each bearing can be regu-
lated to suit requirements while the unit is in operation.
Feeding through the BIowotT Pipe — About the only excuse
for feeding a boiler through the blow off is that it helps keep
the pipe clear. A circulating pipe connected outside of the
setting will do as well and allow the boiler to be fed in a
safe manner through an internal feed pipe.
.
po w e i:
Vol. 41. X... 22
Verier WnriimE for LigMmig' dirndl
>r Service*
r.v A. 1.. Cook
SYNOPSIS — Power panel-boards; the two-wire
direct-current system, ami single-phase, two-phase
ay)d three-phase <r power. Full direc-
tions for calculating circuit* arc given, together
with ill ust rati re examples. The series concluded.
The choice as to the use of conduit or open wiring for
power cin-uits in factories ran lie based upon the same
considerations as were discussed in connection with the
calculations of lighting circuits. If open wiring is to
be used, it should he confined to tin- feeders, which can
he located on the ceiling of the room, where they are
not exposed to damage; and the branch circuits, which
must run in more exposed places, should he placed in
conduit. If a combination system of this kind is em-
ployed, a suitable bushing such as a condulet should be
used at each end of the conduit, since an ordinary iron
conduit bushing will not he approved by the inspector.
This also applies to the end of the conduit at the motor
and at the switchboard. The wire used i- the same as
for lighting service and i- installed under the same rules.
Usually, the branch circuits for a group of motors
can best he supplied from a common point at which a
panel-board is located. Each branch circuit on the pan-
el-hoard should he supplied with a knife switch and
fuses. Sometimes a switch and fuses in the main bus-
bars of the panel are also provided, hut this is not nei es-
sary unless other - ihfeeders are supplied from the panel.
Spare circuits should always he provided in every panel-
board, the size and number depending upon the probable
additions to the motor equipment.
For an installation of any size, one or more switch-
board panels must he provided either at the service point
or the power station. These panel- should contain a
circuit-breaker for each feeder and may or may not have
a knife switch, depending upon the type of circuit-break-
er used. If the board is under expert supervision, a-
in a power plant, fuses lor each feeder may be omitted.
The "Code" does not allow a fuse larger than 600 amp.
for 250 volts or less, and 400 amp. for 550 volts; so
circuits of larger capacity must he protected by circuit-
breakers alone. For direct-current service, the carbon-
break type of circuit-breaker with overload trip is satis-
factory for most uses. For alternating-current service
the carbon-breaker type is satisfactory for 110 or 220
volts, but for higher voltages an oil circuit-breaker is
much better. For these high voltages it is difficult to
get sufficient spacing on the switchboard between ad-
jacent circuits to make the use of carbon circuit-breakers
safe. The cost of the oil type i- greater, hut the result-
ing saving in the size of switchboard and the more satis-
factory operation make it- use desirable.
For power feeder- it is always best to provide circuit-
breakers of some kind rather than to use fuse- only.
because the fluctuations in load would result in great
expense for replacing Mown fuses if they were depended
upon to open the circuit in all cases of overload. The
first cost of the switchboard i-. of course, greater, but
the saving in replacing fuses and the ability to restore
the service more promptly after an overload fully justi-
!|"- use of circuit-breakers, particularly in industrial
establishments. They can often lie used to advantage in
protecting individual motors, and of course they must be
used for load- exceeding the rating of the largest fuses.
According to the "Code," if circuit-bn used
for -mailer loads, fuses must also he used unless the cir-
cuit-breakers are under expert supervision, as in a power
bouse.
Two-Were System
The method of laying out a two-wire system for power
is similar to that for lighting. The usual arrangement
woidd be similar to that shown in Figs. S and '.» (page
668, May l.S. 1915), each panel-board supplying a num-
ber of motors. Usually, the two-wire system is employed
for direct-current supply, the single-phase system, which
al-o uses two wires, being suitable only for small motors.
In the following, therefore, only the direct-current two-
wire system will be considered. A two-wire supply for
motors may be obtained from a three-wire system by
connecting across the outside wires of the system. Some-
times the motor- are run from the same feeders that sup-
ply the lights on a three-wire system, but this is not
desirable because of the voltage fluctuations and greater
liability of interruption: and it is therefore best to run
lower and lighting feeders from the supply
point.
In locating the panel-boards and -witchboards, the
same- considerations apply as for lighting service, already
discussed. The size of wires for the individual motors
may he obtained from Table 11 (page 703, May 25,
1915). This table does not take into account voltage
drop, which should he calculated by means of the wir-
hart, assuming full-load current on the motor. If
the drop exceeds about 1.75 per cent, the size of wire
should be increased. When the size of wire has been
checked in this manner, the fuses for the branch circuit
should he chosen, using Table T (page 642, May 11,
L915), and fusing to the full capacity of the wire, unless
this fuse is the only protection for the motor, in which
case 35 or :!(> per cent, overload should he allowed.
I" total C ie. ted load on each panel-board may be
obtained by adding together the full current of all the
motors on that panel, with a proper allowance for spare
circuits. This result is then multiplied by the load
factor, an estimate of which must he made carefully;
in the absence of definite information 0.75 would be a
fair figure to use. After the load has been calculated.
the size of the feeder may be determined by reference
to Table 7. The voltage drop with the given load
should then be determined, and if it exceeds about 3.25
per .cut., the size of wire should he increased. If the
r supplies several panel-boards, or if the motors
are connected to various points on the feeder, the drop
should lie calculated for each section separately ami these
values added to obtain the total drop. The size of fuses
or the setting of the circuit-breakers on the feeders
.Tunc
101;-)
P O \Y E Pt
737
should be such as to allow the full current capacity of
the wires in accordance with the values given in Tabic 7,
irrespective of the actual loads on the feeders.
Three-Phase System
The three-phase system for power supply would em-
ploy three wires with equal voltages between them. The
four-wire, three-phase system would not be used for
motors, the neutral wire being used only when lighting
is to be supplied. Ordinarily, three-phase motors re-
quiring three leads would lie used, although small single-
phase motors might be run from a three-phase system
by connecting them across one of the phases. The gen-
eral arrangement of the branch circuits and feeders
would be similar to that for direct-current. Because of
the higher voltages which may be used, however, the
branches may be made longer and the number of panel-
boards thereby decreased.
The sizes of the branch circuits for individual motors
are given in Table 12 (page 703, May 25, 1915), which
applies to squirrel-cage motors, [f motors of the wound-
rotor type are employed, the wire should be made large
enough to carry at least 1.5 times lull-load current,
using column A or 1! of Table , (page 642, May 11,
1!>15), to determine the size. In this case the starting
current would be only slightly greater than the full-load
running current, consequently fuses selected to protect
the branch circuits would also protect the motor, so that
the so-called "running fuses" used for squirrel-cage mo-
tors could be omitted. All three of the wires should be
of the same size, as the currents are equal in all of
them.
Table 12 takes no account of the drop in voltage on
the wire-;, therefore this should be checked. If a drop
of 1.75 per cent, is allowed between terminals of the
motor, as previously specified, a drop of 0.58 of this
value, or I per cent., can be allowed in each wire. After
figuring the direct-current drop for one wire, calculate
the alternating-current drop by the method previously
described. Take, for example, a 50-hp., 4t0-volt, 60-
eycle, three-phase motor. From Table 12 it will be
found that the size of wire should be at least No. 0.
The full-load current is CI amp. If the length of the
branch were 100 ft., the direct-current drop would be
1.24 volts for two wires, or 0.62 volt for one wire. As-
suming that the wiring is in conduit, it will he found
from Table II (page 705, May 25, 1915) that the ratio
of reactance to resistance is 0.38. With a power factor
of 0.85 (see Table 15) the drop factor is 1.07; hence,
the alternating-current drop per wire would he 1.07 X
0.62 = 0.66 volt, and the total drop, 1.73 X 0.66 =1.11
1 14
volts. This is only ~- 0.002, or 0.2 per cent.,
which is much below the maximum of 1.15 per cent,
allowed for the branch drop. In this case, therefore,
the size of wire is taken as No. 0 because it is the smallest
wire which will carry the current safely. If it had been
found that the drop was greater than 1.15 per cent., the
wire size would he increased as required.
In determining the total load on a panel-board, it is
necessary to estimate the maximum load which would
have to he supplied at any particular time. As previ-
ously explained, this would generally lie less than the
sum of the full-load currents of all the motors supplied
from the panel. With squirrel-cage induction motors
care should he taken that the wire is large enough to
carry the starting current of the largest motor together
with the normal running current of the others. For ex-
ample, suppose a panel-board supplies the following
motors :
One 15 -hp., 220-volt 3S.6 amp. full load
One 5 -hp., 220-volt 13.4 amp. full load
One 7.5-hp., 220-volt 19.6 amp. full load
One 10 -hp., 220-volt 26.6 amp. full load
Total 98.2 amp. full load
Suppose that, from a knowledge of the operating con-
dition-, the load factor can lie taken at 0.15; the maxi-
mum current would then be 0.75 X 98.2 = 73. C amp.
There is also a 20-hp. motor supplied by this panel-
board, which, when starting; take- 158 amp. The total
is the combination of the running current of the several
motors and starting current of the 20-hp. motor. The
running currents arc, however, at a power factor of 0.80
and the starting current at a power factor of about 0.50.
hence, they cannot he added together directly; in fact,
the total current i< less than the sum of these two cur-
rents. To add these currents, we have to divide each
into a "reactive" part and a "resistance^" part by multi-
plying by the proper factor. The values of these factors
for the usual power factors are as follows:
TABLE 16 — REACTIVE AND RESISTANCE FACTORS
Power Factor Reactive Factor Resistance Factor
i.oo o i oo
0.95 0.31 0.93
0.90 0.44 0.90
a 85 0.53 0.85
0.80 0.60 0.80
0.75 0.66 0.75
0.70 a 71 0.70
0.65 0.76 0.65
0.60 0.80 0 60
0.55 0.84 0.55
0.50 a S7 0.50
0.45 0.89 0.45
0.40 0.92 0.40
Applying these factors to the example.
Resistance Pactob Reactive Pactob
73.6 X 0.80 = 50 73.6 X 0.(i0 = 44.2
158 X 0.50 = 79 158 X 0.87 = 137.5
138 l-si.;
The total current is V (138)'-' + ( 181.7 )2 = 22s.-.'
amp.
Prom Table 1 it will be seen that a No. 00 wire would
probably be sufficient. If the two current- were added
in the usual way the result would be 231.6 amp., which
in this case would approximate closely the total current.
The nearer alike the power factors of the two currents,
the less need there is for employing the exact method
rriven above.
The arrangement of feeders and subfeeders supplying
the panel-hoards may be laid out in the manner alreadj
described. Usually, there will he two or three panel-
boards supplied from feeder, hut the number will
depend upon the size of the motors and their location.
It is desirable to keep the number of feeders a mini-
mum, and on the other hand, it is not wise to use ex-
cessively large Feeders, because of the great voltage drop.
In general, the use of a feeder larger than 300,000 ciiv.
mils is not justified when alternating current is used.
The drop on the feeder should be calculated in a manner
similar to that employed for the branch circuits, as has
already been explained. The current to be used should
be the maximum-load current, which is calculated by
multiplying the sum of the full-load currents of all the
motors (including an allowance for the spare circuits
on the panel-board ) by the proper load factor. When
p o w e i;
Vol. II. No. 22
a motor is starting there will be a larger voltage drop,
lmt this occurs only for a brief period and can generally
be neglected if there are a number of motors on the
feeder. When squirrel-cage induction motors are start-
ing the current is large and the power-factor is about
0.50. There would therefore be momentarily a very
large drop if the motor starting is large as compared
with the other motors. An approximate value of this
drop can be determined by neglecting the drop due to
the motors running, and calculating the drop for the
motor starting alone. The actual drop would then be
somewhat greater than this owing to the current taken
by the motors running, but would be less than the sum
of these two drops. The reason for this is that we have
a different power-factor for the running motors and the
motor starting, and therefore, the total drop is less than
the sum of the two drops.
Two-Phase System
Either the four-wire or the three-wire, two-phase
system may be used. If the four-wire system is used,
the two windings of the motor are connected across the
two phases of the supply; with the three-wire arrange-
ment, the windings of the motor are connected between
the outside wires and the common wire. Care must be
taken that neither of the windings is connected across
the outside wires, as this would subject the winding to
an excessive voltage. If the motors are provided with
three Terminals, the common terminal must always be
connected to the common wire. If the direction of ro-
tation is to be changed, this should be done by reversing
the connections to the outside lines, keeping the common
lead connected to the common wire of the system. If
a motor having four terminals is to be connected to a
three-wire, two-phase system, the two windings of the
motor must be identified, by testing if necessary, and
then one terminal of each winding must be connected
to the common wire. The three-wire, two-phase system
is commonly used, because of the saving in the cost of
the circuits. The relative values of voltage and current
in the various leads of the two-phase systems have al-
lien explained in connection with the calculations
of lighting circuit-, and the length and general arrange-
ment of the branch circuits are governed by the same
general rules as were given for the other systems.
In Table 13 is given the full-load current and the mini-
mum wire size for two-phase, four-phase, squirrel-cage
induction motors, the current given being the value for
each of the four wires: the size of wire also refers to
each of the four wires. If a three-wire, two-phase sys-
tem is used the currents in the outside wires and the sizes
of these wires are as given in the table, while the current
in the common wire is 1.1'.' times that given and hence
the size of this common wire must be increased pro-
portionately. For example, assume a 50-hp., 220-volt,
two-phase motor, with a four-wire system ; the size of
each of the four wires would be Xo. 0000 and the full-
load current 105 amp. With a three-win.', two-phase
system the two outside wires would be No. 0000 and
each would also carry a current of 105 amp. at full load.
When starting, the current in the outside wires is 2.'.) X
105 = 305 amp., which requires a Xo. 0000 wire, as
given in the table. The starting current in the common
wire, however, i- 305 X 1-42 = 434 amp., and from
Table 7. a 400.000-circ.mil wire will be found necessary.
If the wound-rotor type of motor is used, the wire
should be sufficient to carry at least 50 per cent, overload
continuously. Hence, in the case of this 50-hp. motor
the current would lie 1.50 X 105 = 158 amp. If four
rubber-covered wires are used they should each be No.
000, and if three wires are used the outside wires should
be Xo. 000. The maximum current in the common wire
would be 15S X 1.42 = "2 2 I amp., which would require
a Xo. 0000 wire. In the case of squirrel-cage motors
running fuse- are required : that for the common lead hav-
ing a capacity about 1.42 times that for the otitside leads.
In the foregoing no account has been taken of the
cottage drop, the size of wire given in Table 13 being
the minimum size that should be used. It frequently
happens that the voltage drop for the branches is small
for either three-phase or two-phase systems because of
the high voltages used. In any case, however, where
there is a possibility of the drop being excessive, cal-
culations of this should be made. In a four-wire sys-
tem, since the Two phases are independent, calculate the
circuit as if it were a two-wire, single-phase system, and
calculations need !«■ made only for one phase. The
drop on one phase can first be calculated by means of
the direct-current chart and then the proper correction
made for alternating-current by means of Tables 14 and
15. The allowable percentage drop in the branch cir-
cuits is about 1.75 per cent, for each phase. For ex-
ample, take the 50-hp. squirrel-cage motor already men-
tioned. Assume a frequency of 60 cycles, a power factor
of 0.85 and a length of branch circuit of 200 ft. As-
suming a four-wire system, the smallest-sized wire which
can lie used is Xo. 0000 and the full-load current is
10.". amp. Hence, the direct-current drop on one phase
would In- 2.1 volts. If the wires are in conduit the
ratio, from Table 14, is 0.76 and the drop factor is
given in Table 15 as 1.27. Therefore, the alternating-
current drop is 1.27 X 2.1 = 2.07 volts. This is 2.07
-;- 220 = 1.2 per cent., and the size of wire is satis-
factory.
If a three-wire system were used, the drop would be
calculated as follow-: The current in each outside wire
would be the same as before, namely. 105 amp. Heme.
the drop in each of the outside wires would be 1.05
volts, from the direct-current chart. With alternating
current, the drop in each outside wire would be one-half
that previously found, or 1.34 volts. Since the currents
in both outside wires are the same, the current in the
common wire is 1.42 X 105 = 149 amp. under full-
load conditions. It has already been found that the min-
imum size of this wire is 400.000 circ.mils, and the
direct-current drop for this wire, with 14!) amp. flowing,
is given by the chart as 0.8 volt. For alternating cur-
rent, the ratio in Table 14 is 1.49 and the drop factor
1.67 from Table 15. Hence, the drop on this wire is
1.61 X 0.8 = 1.34 volts. The total drop on one phase is
V 1.34- 4- 1.34- = 1.9 volts or 0.9 per cent., which shows
the sizes chosen to be correct.
In finding the total load on the panel-board the meth-
ods described under the three-phase system should be
employed, using the proper load factor and allowing for
the starting-current. The drop in the wires may be cal-
culated by the rules given for the branches, since in
all case- the loads are balanced. The same rules legard-
ing the combination of currents at differenl power factors
apply.
.! ■ 1, 1915
POWER
739
ffil(DF<
01 EH
apacM^
By Joseph II irrington
SYNOPSIS— Stirling boiler furnace equipped
with Roney stoker remodeled -« ihnl the capacity
of Ihr boiler was increased from ISO to S09 per
cent, of rating. Attention in the dampers in-
ed ihr draft over Ihr fire. An extension of
thr furnace arches nnJ the stopping of needless
poking of Ihr fire obviated dense smoke.
Having had occasion recently to overhaul a plant Eoi
the combined purpose of increasing capacity and de-
creasing smoke, the results obtained may be of interest
to Power readers. The plant in question consists on
its steam-generating side of 500-hp. Stirling boilers
equipped with Roney stokers having 103 sq.ft. of grate
surface. Two 1 75-f t. stacks serve the two lines of boilers
through straighi breechings of ample proportions.
This plant had not only been making objectionable
smoke, but it was not possible to get from it much more
than the boiler rating. Preliminary tests under the
former operating conditions gave but 030 hp., or 130
per cent, of rating. These unsatisfactory results were
partly the fault of the initial design ami partly the result
of defective stoker conditions and operation.
A< in the majority of smoke problems, this one was
founded on the insufficiency of the draft. When the
furnace draft was brought up to the point corresponding
to normal condition-, combustion was noticeably affected.
The actual increase was about 30 per cent., or from 0.33
Fig. 1. Diagrammatic Analysis of
Original Conditions
to 0.48 in., which under these conditions meant a radical
difference in the furnace efficiency.
A part of the draft loss was due to a large damper in
the main breeching near the stack. This was originally
intended to be operated by a damper regulator, but had
fallen into disuse and. although left wide open, was re-
sponsible for considerable interference with the gas
flow. Its removal was a benefit, and owing to the slight
friction loss in the breeching the rtack draft was ap-
proximated at the boiler dampers. Dampering is usual-
ly overdone or underdone, and its influence for good or
evil is still but little1 recognized. With the writer the
conviction is gaining that a main breeching damper
Fig. 2. The Remodeled Furnace
should be used only in certain special cases which must
be selected with discretion.
Another heavy loss was chargeable to dampers, only
this time it was the individual boiler dampers. Like
the majority, these dampers did not close tight enough
to exclude air leakage through the cold boilers. This
was heavy, and the resultant volume of gases and in-
filtrated air was so great as to overload the stack.
Temperatures were affected and the friction loss increased
so that nothing like normal draft intensities were reached
until this infiltration was -topped. Some day the
idea of having airtight boiler dampers will lie seriously
proposed and find many advocates.
Sufficient draft in the furnace having been acquired, it
was necessary to see that the furnace itself was able to take
care of the increased volume of gases evolved at the higher
capacities. An analysis of the furnace condition- i-
shown in Fig. 1. The cause of the smoke is apparent
at a glance. Much of the volatile matter was slipping
around the end of the short arch, across the chamber
above, to the upper end of the first bank of tubes. The
heavy excess of air at the lower end of the fire was filling
the flame spaces of the front bank and holding away the
hot gases that might otherwise have come into contact
with tin' tubes. At the upper end of the furnace, tempera-
tures were so far down that further combustion was
impossible. The rest of the story was readable at the
top of the stack.
Just as the cause became apparent, the remedy was
obvious. In Fig. 2 is shown the furnace designed for
this ease. Extended comment is unnecessary. A more
liberal supply of air was provided under the Roney arch
and the proper fuel-bed thickness for different ratings
was determined.
An important item was the handling of the stoker The
men seemed to think that the more they poked the bettei
they did. This was all changed and the stoker allowed
to do the work. Intelligent and effective coupe >
on the part of the chief engineer resulted in the develop-
r-io
I'd WEE
Vol. 41, No. 22
ment of skilled firing, with Less distress to the men and
far better results from the stoker. It became apparent
immediately that the stoker would do the work if left
alone, and today it is the practice to poke only when
there is special reason for it. Poking is done locally
and as little as may be required to trim the fires in that
particular spot.
ities up to 243 per cent, of rating were obtained
for eight-hour periods, with an average increase in ef-
ficiency of 8 per cent. The highest hour showed 1545
lip., or 309 per cent, of rating. This was done without
any injury to the stoker or furnace and without objection-
able smoke. Furnace temperatures naturally were high,
owing to the high rate of combustion and the reduction
in excess air. On the high rating test an average of
13. IT per cent. CO, was obtained at the end of the flame
ind 11.96 per cent, at the damper. Moreover, practically
all of the combustion took place in the furnace, which
besides producing a high temperature was favorable to
the absorption of the heat, the completely burned gase
sweeping over the entire heating surface. The damper
draft was 1.28 in. and the furnace draft 0.578 in.
While reference was just made to the highest capacity
test of the series, the average was well above double
rating. To give a better idea of the principal results,
a table containing some of the averages is appended.
SUMMARY OF PRINCIPAL RESULTS
musi gei under the scale, for the hydrogen bubbles must
have their source in the water and not in the metal.
The developmenl of this elaboration on the zinc-plate
method of combating corrosion will be watched with in-
terest.
Coal
Evap.
TJptake
Fur.
per
F. and
Per
Fur.
Corn-
Draft.
Draft.
Flue
Sq 1 ■
Capa-
A. as
Cent.
and
Test
In. of
In. of
Temp.,
of
city,
Fired,
Exces.
Grate
Effi-
Xo.
Water
Water
Deg. F.
Grate
Hp.
Lb.
Air
Eff.
ciency
4
0.881
0 451
7_'s 53
39 46
1039 2
S.654
S3 0
93.3
77.31
5
n «:,
0.447
663.20
48.70
1039 0
7 010
65.0
89.6
63.36
6
0.936
0.447
694 . 30
47.96
1OSO.0
7 408
67.0
90.2
66.9(1
7
0 619
0 313
677 22
46 40
1076.9
7.621
65.3
84.6
64.40
8
0.702
0 356
741 25
43.36
Mil II
7.400
54.5
87.8
68 30
9
1.2S0
0.57S
747 211
55 Til
1188 ii
6.774
66 5
S8.3
61.90
10
D.891
0.449
733.60
53 57
1211 1
7 440
42.0
93.0
65. IS
To prevent the electrolytic corrosion of boilers and
similar vessels, the Cumberland Engineering Co., of Lon-
don. Eng., has developed a rather interesting apparatus.
Essentially, it consists of anodes that are insulated, that
is, connected to the boiler shell by an insulated bolt, and
that form the positive side of the circuit, while the shell
itself is connected to the negative side, making it the
cathode. The aim is to pass low-tension current, which
may be regulated by resistances fixed on a switchboard
or similar place. The current is supplied at from G to
10 volts, and an ammeter mounted on the board enables
the operator to tell how much current he is sending
through.
The elements of the water contained in the vessel are
elctrically charged when the current is on, and at the
anodes there assemble the anions. When this occurs a
film of hydrogen i~ said to form over the immersed portion
of the vessel, thus protecting the latter; the oxygen, acid
and other corrosive agents being attracted to the iron
anodes, which become reduced just as zinc slabs do and
must be renewed.
The claim is made that hydrogen, in being liberated
from the surface of the metal in bubble form, tends to take
from the surface any scale or other matter that may lie
clinging to it. This claim, then, presupposes that water
In 1884 the Sehliehter .lute Cordage Co.. of Frank-
ford Junction. Perm., started
to put up a 200-ft. brick
chimney, when it was found
that the ground upon which
the chimney was to stand
overlay a quicksand into
which a %-in. iron rod
would settle, if released, be-
yond hope of recovery. Mr.
Herman Dock, to whom the
design and construction of
the chimney had been in-
trusted, simply cast a block
of cement 30 ft. square and
5 ft. in thickness in an ex-
cavation, where it was de-
sired that the chimney should
stand, and built the chimney
upon this floating block with-
out any piling or other sup-
port. The chimney is square.
as shown in the accompany-
ing photograph, 13 ft. at
the base and 11 ft. 6 in. at
the top. and is composed of
solid masonry without any
i Hie. the internal dimensions
being G ft. at the bottom,
and. contrary to the usual
practice, G in. greater at the
top. Its height is about
200 ft. and its total weight
something like 1000 tons.
It sways freely in the wind,
and its movement may be
felt by putting the hand be-
tween it and the engine-room
wall, but it has suffered no
permanent departure from
the vertical. Four hundred
barrels of Portland cement
were used in casting the floating base: 1200 hp. of boilers
are attached.
8
Steam Consumption in Pumpinc — The common type of di-
rect-acting pump, so much employed in mining, is well known
to be wasteful in respect to the consumption of steam. This
is owing to the necessity of using steam at full pressure
throughout the entire length of stroke. Only a compara-
tively few pumps are designed to use steam expansively
and these are not adapted to the commonly high lifts in
mining. Steam consumption, in pumping, ranges from 10 or
15 lb. per i.hp. per hi., in triplex, flywheel pumps when run
condensing, to an average of 150 lb. per i.hp. per hr. in direct-
acting pumps. The consumption of steam, in pumps of the
latter type, varies from 100 to 200 lb. per hp. per hr., depend-
ing on the speed of the pump and its condition. In this elass
of pumps, the consumption of steam is less as the speed is
increased. — "Coal Age."
The Floating
Chimney
nil;
row e i;
711
\\-\ Thomas J. Rogers
The pump or pumps used in connection with a hy-
draulic elevator system should be of sufficient capacity
tn deliver the maximum quantity of water required
promptly on demand. Their are times during the day when
the elevator system is heavily and quickly loaded and the
water required is considerably more than the average
quantity per minute pumped during the rest of the day.
A pump large enough to care for these rush periods at a
slow speed would, of course, he uneconomical during light-
load periods. A common practice is to have a relay pump
which may be run together with the main pump when
the quantity of water required exceeds the capacity of one
unit.
The crank and flywheel pumping engine for large ele-
vator installations is superior in steam economy to other
types, hut is not available in small units, because it can-
not he stopped and started automatically; ami if kept
running constantly it will pump through a bypass part
of the time and much of the possible economy will he
lost.
The writer has obtained good results with a compound
separable duplex pump, in which either side may lie op-
erated independently of the other or both run together
in duplex. This machine can he operated intermittently
according to the demands of the service, and it is under
governor control; it can he stopped when the proper
pressure has been established and there is no demand for
water, and started quickly when a slight drop in pressure
occurs in the tanks due to the operation of the cars. When
running duplex each of the two steam ends has control
of the closure of its own steam valves, ami the opening
of them is controlled by the opposite engine.
The stroke is long and constant and the valve area
large, though each valve is of small diameter. This type
of pump closely approaches the economy of the crank and
flywheel pumping engine, requires less attention, and
the cost of operation and repairs is so much less than
for the crank ami flywheel type that, considering first
cost, cost of foundations and installations, it is quite as
economical an installation. It has the further advantage
that it can be run either duplex or simple, one side only
being operated during the periods of minimum demand,
juch as for night service, Sundays and holidays. This fea-
ture is particularly convenient when it is necessary to
examine the piston packing, valves, etc, or when making
examination or repairs to the steam end. as one side may
be operated while such work is being done to the other
side. This, of course, is impossible with the ordinary
duplex pump or the crank and flywdiecl engine.
The maximum economy of any steam engine is obtained
only when it is running at its full normal speed. In
the case of a duplex or a crank and flywheel pump operat-
ing during the periods of minimum demand, the engine is
necessarily run much below this speed; but in the ease of
the separable duplex type described, one side is shut down
and the other operated at its full normal speed, meeting
only the decreased demand.
On the steam end the method of connecting up is sim-
ple. It is well to use one valve in the main steam line
•and one in each of the branches, the exhausts being
brought out and connected together in the most conven-
ient manner to suit the situation. The side elevation
shows the auxiliary steam chest and the control valve
fitted to the side of the main steam chest, and by means
ol which the proper "timing" or duplex action of the two
pumps is secured by movement of the piston in this aux-
iliary chest through the duplex lexers and rods shown.
Working duplex, this machine operates positively and is
a true duplex, hut not subject to short-stroking. Throw-
ing the pump in or out of duplex is the work of hut a
minute, requiring only the pushing in of the handles
of the control valve on the auxiliary chest on both sides
to throw the pump into duplex running, or throwing them
out of duplex by merely pulling these handles out.
When the pump is running as a duplex machine and it
is desired to shut down one side, both handles are pulled
out. leaving the pumps running for the minute as two
separate units, then by shutting the valves on one side
Auxiliary Valve
Elevation ind Plan of Elevator Pump
that pump is cut nut, while the other side continues to
operate as a single-cylinder, double-acting pump.
The water end should he titled with two valves nexl
to the cylinders which should connect to the main pump
discharge through a tee. In case of running one side
and opening the other cylinder for repairs, renewal of
valves, etc., the closing of the valve next to the cylinder
out of commission would isolate that one on the dis-
charge side. The suction may have two separate lines at
the pump.
In fitting an elevator pump, no matter what type,
it is well to put relief valves on the water cylinders so
that if by any chance the pump should be started with the
stop valve in the main discharge line closed, excessive
pressure will not be created in the pump cylinders. In
such cases the relief valves usually discharge into the
surge or the suction tanks.
Pumps used for delivering water up to about 250 lb.
pressure into a closed tank, as on hydraulic-elevator sys-
tems under air pressure, are usually controlled by a pump
1 12
P 0 W R B
Vol. 41, No. 22
pressure regulator. Where the pressure carried is above
250 lb. and up to an exceedingly high pressure an accumu-
lator is used to govern the speed of the pumps.
Owing to the nature of the service being intermittent,
the water on the suction side should flow to the pump
h\ gravity with a head of from four to live feet over
the under side of the discharge valves.
A aecessarj fitting to the water end of a hydraulic
elevator pump is a suction air chamber. While the ma-
i nine is in operation the water is rushing into the pump
with considerable force, and should the regulator act and
the machine stop at the end of its stroke, the water will
continue to rush in with force enough to raise the suc-
tion valves from their seats and allow them to fall back
with a loud pound. The pump air chamber prevents this.
The discharge air chamber should he kept at least three-
quarters tilled with air under pressure, and by application
of ;i gage-glass its contents can he seen at a glance. A
good method of recharging the discharge air chamber
with air, should it become filled with water, is to run a
line from the top of the air chamber to an air compressor
with a check valve in the line close to the air chamber.
If an air compressor is not available the best way is to
attach an aerating valve in the suction line between the
suction valve and the pump, and by running with this
valve open to the atmosphere and the suction valve closed
or partly closed, the machine will draw in air and force
it into the discharge air chamber.
©tors to
imiess
Bvi
By Bill B. Bangek
SYNOPSIS — The alarming prospect revealed by
the clipping (and it is an actual one that is repro-
duced) from the Eureka . What it really
shows is central-station enterprise.
While I was loalin" around my engin' room th' other
day a feller blew in and started to look over th' shebang.
lie seemed mighty interested in th' generators, peeked
into "em here and there until I began to fear it would
be necessary to send for an ambulance or an undertaker.
"Mr. Banger.'" said he after a spell, and I pretty nigh
lost my equilibrium, seein' it's so long since I was called
anythin" hut Bill, except by th' firemen, who call me
most anythin". ".Mr. Banger," says he. "this electricity
stuff is all to th' futurity; you and I may not live to see
any particular progress along electrical endeavors, but it
will come, it's sure to come !''
I hadn't given th' feller much attention more'n to see
he didn't get electricuted or fall into th' flywheel or
some such minor accident, hut his remarks made me hesi-
tate in th' even tenor of my ways and squint at him
over th' top of my glasses, which I have to wear on special
occasions. A man with such broad perception of th' gen-
eral trend of things, especially along electrical lines, was
worth lookin' at a second time, by heck. Somehow or
other, I had got th' idea that some considerable progress
had been made in th" electrical generation and trans-
mission of power and was somewhat surprised to hear that
it wasn't likely that th' stranger and myself wasn't
liable to live to see any material progress in electrical
matters, leastwise not of a startling nature. Seein'
1 didn't have anythin' to say. 1 kept my mouth shut for
once and waited for the next spasm.
"You'll tie surprised, Mr. Banger."' said he. "to see
how electrical matters are progressin' in our town of Eu-
reka. Of cour.se, we don't come up to New York, hut
when you compare th' difference in size we are a close
second, and lots of people are beginnin' to tumble to th'
fact that we are on th' map. Of course, our trolley ser-
vice ain't as big as what you have in this here city, but
we get there just th' same.
"And our great white way is some class, I can tell you.
One big electric light in front of th' grocery store and
two in front of th' movin' picture sho', all on th' main
street. Some town, I tell you."
Before I had a chance to say anything he started off
again until I thought he was wound up for good. "I'll
tell you. electricity is goin' to work havoc with th' steam
and gas engin's and I can prove it." Whereupon he pulled
out a newspaper clippin' and handed it to me to read.
Here is what it said : [A reproduction of the clipping is
shown herewith. — Enrroi;.]
YF11L USE ELECTBIC POWEB.
Two Large Eureka Institutions Will
Use Jfew Power.
Electricity is rapidJy replacing steam
and gasoline engines as a means of
power. The Eureka Roller Mills has
placed an order with the Eureka Light
and Power Company for a 20 horse
power motor. This large motor will
soon be here and will be given a
thorough tryoivt by the milling com-
pany. As soou as the motor has prov-
en to the satisfaction of the manager
that it will do the work expected of
it, the engine now used will be dis-
carded.
The Home Steam Laundry will in-
stall five electric motors. These are
now here and will be connected up in
p. few days. This order consists of
five motors — two 5-horse, two.2-horse
and one on-half horse. These five
motors will do the work now done by
a steam engine and are supposed to
be much more economical. The steam
engine, however, will be retained in
order to furnish steam and hot water
for laundry purposes.
Well, I swan! When I finished readin' that clippin'
I felt like putty nigh goin' over in a heap on th' engin'
.Inn. 1, 1915
p o w ]•; i;
743
room floor. Just to flunk of ;i large 20-hp. motor bein'
given a tryoul to <■ if it would acl satisfactorily! If th'
motor does come up to th* scratch — and I calculate that
there might be some doubts about it. seein' it's such a mon-
ster— I suppose tli" large 20-hp. steam engin' what has
been runnin' th' mill will have to go.
My \isitor said there wasn't any more progressive
parties in th' town than th' mill and th" laundry people,
Ian I wondered how th" laundry people figures th' thing
..hi that th' 15*4 hp. in motors was goin' to be a gain,
when they were goin' to keep th' old boiler — no it's th' en-
gine— to furnish steam and hot water for laundry pur-
poses.
It looks to me as if th' roller mill and laundry people
wem't th' only ones that had their eyes peeled It
seems somewhat like as if the central-station evil, as it's
sometimes called, was abroad in th' midst of Eureka and
that tli" business solicitor was a feller whal was on to his
job.
When 1 finished readin' th' clippin' Mr. Man was
standin' with his thumbs in th' armholes of bis vest, and
I Swan! When I Finished Readin' That Clippin' I
Pbettt Nigh Fell Into a Heap on th' Engin'-
Room Floor
was teterin' back and forth on bis toes and heel6 like a
i- performer, and lookin' prouder nor a pussy cat
with a litter of little toms.
"Some units." say- he, "and it all goes to show that our
people are awake to th' savin' what can be had by usin'
electricity."
"That's as may he." says I. "Of course, 1 don't know
how ..hi that 20-hp. engin' is or how much steam it chews
up per horsepower developed, which might be from i; ni-
ls up to 60 or "it Ih. per horsepower, ii all depends on th"
. agin' and th' engineer what has been nursin' th' thing.
"If th" engineer at th" mill is goin' to be kicked out in
ih' cohl and tli" steam plant shut down, and if th" charge
for electrical energy is low enough and if th' steam en-
gin' was a steam eater, why there is a chance — mind, I
say a chance — that th" mill people will come out at th"
nd of th' horn. If th' engin' is a good one and tli'
neer knows his business, and if th' cost of juice ain't
right, then 1 would ad - them mill fellers to keep cool
aii.l not he in a hurry to throw th' engin' and boiler out
onto tli' scrap heap. They might be -lad to start 'em
up again when th' eontracl with th' electric company
runs out." -a>. - I.
Th' stranger kinder looked stalled awhile and said
he didn't think any mistake had been made and that even
if it did cost more to run th' mill by motor than by
steam, it didn't matter much, hut showed that they wen
progressive anyhow. "Don't you know that th' intro-
ii of all new innovations is prone to result in finan-
cial losses, more or less?" says he.
"Well," says I. "there is somethin' in what
and so we'll let th' mill proposition drop and take a whack
at th" wash factory. Accordin' to th' clippin' th' boiler —
no th' engin' l.ut we'll assume it'- th' boiler — is ;
hung onto and kept in th' business. Tt will take jit
many men to run that boiler for keepin' up steam and
heatin' water as it did to run th' boiler and th' 15%-hp.
engin'. Th' only difference in th' operatin' cost will he in
th' savin' ..I' fuel that was i < I. urn to keep th'
engine' goin', and a few quarts of engin' oil once in a
while. Now, accordin' to all precedents, it's goin' t.. .-..-i
more to run them motors than it would to buy coal to run
th' engin', unless a mighty low rate for juice has been
made. I would give th' wash fellers th' si ■ what
I handed out about th' mill. It won't h* a mite foolish
lor "em to keep th' engin' right t.. home, foi bere have
been lots of cases where engin's have been started up again
after havin' been put on th' shelf while th' company was
learnin' wisdom by experience and handin' out dollars
to th' central— tatioii fellers."
When th' feller was gettin' ready to get out, I gently
put my hand on his shoulder and told him that what looks
big in one place was less than commo in another, es-
pecially in electrical matters, and that although th' two
enterprises in Eureka had put in a total of Sb'Y2 hp. in
motors and while it might, tie a big thing in that town, it
was not a criterion that all steam and gasoline engins were
goin' to be put out of business all over th' country, A 20-
hp. motor may he some stunt in Eureka, hut it would
hardly be able to shift th" hrushes on th' 3750-kw shunt-
wound, direct-current generator that was built about a
year ago.
"Down in th' so called sleepin' city of Philadelphia,"
says I. "they have a 35,000-kw. turbin' generator and out
in Chicago they have a small 25,000-kw. unit. )ut on th'
Mississippi River there is a plant that will, when it's fin-
ished, generate about 300,000 hp., and 150,000 hp. is
now in. and out on th' Pacific coast they have an electric
transmission line 400 miles long, and one line out that way
carries 150,000 volts every day. by heck.
"Just let me give you a little tip," says I. "Elec-
tricity may he for futurity, as you -aid. but it'> a mighty
big proposition now, and unless both of us turn up our
toes pretty dinged soon we are goin' to see some more
big stunts pulled oil'. They won't cause much stir, be-
cause things move so fast these day- that it take- some-
thin' more than an ordinary earthquake to make us take
notice — we take it as a matter of course and don't give a
ding.
"When th' next feller in Eureka puts in a 2o- to 30-hp.
motor you won't pay much att.-ntii.ii to it, for you'll be
gettin' used to progress and take it as a thing to be ex-
pected. (In th' other hand don't he surprised if th' mill
and laundry feller- go had,; to th' steam engin' just as
-...hi a- they get th' chance. Goin'? Well, so long."
744
p o w e i;
Vol. 41, No. 22
nmomnnieaJl Vmetumm for
T
By Winslow II. Eerschel
SYNOPSIS — Discusses the conditions which in-
fluent/' flip degree of rum tan which it is best In
carry mi a turbine.
It is unfortunate that the word "economy" is used for
steam consumption, as a low water rate (lues not neces-
sarily mean economy at the coal pile. That depends upon
the gain in power as compared with the increased cost
of obtaining higher pressures, superheat or vacuum.
The whole question of cost of power is complicated and
depends to such an extent upon local conditions that it
is impossible to find any general formula for obtaining
power at the lowest cost. Without considering variations
in pressure and superheat, factors which mainly depend
500 1000 2000 3000 4000 5000 6000
Work of Air Pump in Foot-Pounds per Pound of Steam
Fig. I. Variations ix Work of Dry and of Wet Air
Pumps for Assumed An; Leakage
on whether a high first cost is more than offset by low
operating expenses, let us confine our attention to the
question of vacuum, since the cost of producing a vacuum
may he measured in units of power and subtracted from
the power of the prime mover to give net or effective
power. What one wishes to know is what vacuum will
give the maximum effective power.
In steam engines, as is well known, the large size of
cylinders required and the great amount of cylinder con-
densation prevent high vacuums from being truly eco-
nomical or from giving a very low water rate, so that a
vacuum of about 26 in. is as high as it is advisable to
go. With steam turbines, on the other hand, it is possible
to have the steam at exhaust nearly at the point of
saturation, so that the question of condensation is of
minor importance, and it is feasible, at least in large-sized
turbines, to design the blading to take care of the highest
vacuum which an air pump can produce. The most
economical vacuum is therefore not determined by the
same considerations as in the case of steam engines.
To simplify the matter it will be assumed that the
cooling water is delivered to the condenser by gravity, and
neglecting the cosl of tin cooling water and the higher
cosl of an installation capable of producing a higher
vacuum, we shall consider merely the power required
to produce the vacuum by pumping the cooling water.
condensed steam and air from the condenser out against
the atmospheric pressure. This problem has been in-
vestigated by Stoilola ("Die Dampfturbinen." Fourth
Edition, p. 548) where he has assumed that the ratio of
cooling water to condensed steam is equal to 50. It is
obvious, however, that this is only an average or special
case, since the higher the temperature of the cooling
water, the greater will be the amount of it required to
produce a given vacuum. In fact, the temperature of
the cooling water available is often the deciding factor
as to whether a steam turbine or some other form of
prime mover shall be adopted, and frequently leads, in
warm climates, to the substitution of the Diesel engine.
The presence of air in the condenser is mainly due
to leakage through the stuffing-boxes. According to tests
of George A. Orrok ("Journal A. S. M. E.," 1912,
p. 1625), while the volume of air in city water at 52 deg.
F. was over 1 per cent., this had been reduced to less
than 1 per cent, in the feed water with a temperature of
18^ deg. F. He found that with turbines of from 5000
to 20,000 kw. capacity, the amount of air discharged
by the dry-air pump, at atmospheric pressure and
temperature, varied from 1 cu.ft. per niin., with the units
in the best condition, to 15 or 20, when ordinary leakage
was present, or to 30 to 50 when the units were in bad
condition. These figures are checked by Stodola's state-
ment that we may ordinarily expect the air to amount to
1.5 to 2.5 cu.ft. per min. for each 1000 kw. capacity.
Thomas C. MTiride (Power, July 14, 1908, p. 74)
points out that manufacturers of condensing apparatus
for steam engines usually allowed for handling from 4 to
fi volumes of air per 10,000 volumes of exhaust steam,
and gives results of tests in which the amount of air
varied from 18 to 74 volumes. These figures arc based
on a 26-in. vacuum and a hotwell temperature of 110 deg.
F. lie also states that the amount of air to be handled
should be as definitely specified as the amount of steam,
or else the air-pump manufacturers should not be held
responsible for the vacuum obtained.
In a more recent article, Prof. C. L. W. Trinks
(Proceedings of the Engineers' Society of Western
Pennsylvania, June, 1914, p. L91 ) gives the weight of
air normally expected by builders of air pumps as 0.25 to
0.50 per cent, of the weight of steam. This would indicate
a growing recognition of the large amount of air usually
present in a condenser and its marked effect in reducing
the vacuum which would otherwise be obtained.
In the calculations three different amounts of air
leakage have been assumed/ — 0.31, 0.62 and 0.93 per cent,
of the weight of steam. These amounts correspond
respectively, to about 20, 40 and 60 volumes of air per
10,000 volumes of exhaust steam, when reduced to
M'Bride's basis of comparison, or to approximately 15.
30 and -15 cu.ft. per min. for every 1000 kw. capacity.
June 1, 1915
row e i;
; !.-
Comparing our assumed values with those of the author-
ities quoted, we may say thai the smallest amount of air
could be obtained with stuffing-boxes in the besi con-
dition, the second amount under ordinary conditions,
while the third value might be reached and exceeded with
the stuffing-boxes in poor condition.
The work done by the air pump is found as follows:
If // is the pressure in the condenser in pounds per square
fool and ps the steam pressure as given in the steam
tallies for the temperature of the condenser, then the
pressure of the air in the condenser is the difference
between these two pressures. Therefore, the weight per
cubic foot of the air is D = — „ _, , where T is the
absolute temperature (that is. 459.6 plus the temperature
in degrees F.) of the condenser, and /,' is the air constant
53.34. Let 1) be the weigh! per cubic foot of steam at
80°
E icn
'!
$■
</)
°
I I
§
<£
o.
TS
|
/
/
u
,
/ /
S
/
1 L-r
,'
'J
o n . i r
60,000
£E
i- the weighl of cooling water per pound of steam con-
densed. The value of m may be found from the equation
/,
t,
where // is the total heat of the steam, I, is the tempera-
ture of the cooling water, and /, is the temperature of
the condenser. The heat // is determined by the vacuum,
I., may be estimated approximately for any given locality,
and /j remains' to be determined so that the sum of IT,
and U*3 shall be as small as possible. It may make the
mutter clearer if we imagine two separate pumps — the
dry-air pump which does the work of compression, II',.
and the wet-air pump which does the work of pumping,
II'.. Then it is evident that with a given temperature of
cooling water and a certain amount of air leakage, the
vacuum may be increased to the desired amount by in-
so"
!
"""]
/
I
I
1 1
y / 1
so
y
///
^^s
v
1 — (-HT
I — — — -Jg
'-
;::
1
1
1 1 ,
1 11
/ / 1
tb(i
// / /
^/■V/ / /
^Wt^&'m
— m 1 fill
::::::
. | SO" 70° <
/ '
l- -III
i
itt
, / / *
"'.",":" i
no air in steam
(impossible)
AIR IN STEAM=03I% BY WEIGHT
{VERY GOOD STUFFING BOXES)
AIR IN STEAM =068 % BY WEIGHT
(GOOD STUFFING boxes)
1 1 ||U<
'
60
'ifff
~\L ___ \^0^\
K?'
\
i^P"-'
III 1 I I ; ^
4f T-'-M
I [W
Ml' so
^^^~^i60°
"ffl-TTTK
^^0^ ^\ \
~
5 26 27 28 .29
.
::: :± w
so
\ \
\ v
\0
0
i ~M -
25 26
n 28 <
9
AIR IN STEAM =093% BY WEIGH
(FAIR STUFFING BOXES)
,V
^*
1 ' ^='
^50
l^z^-^
60
--I---44
M
llf\
-
Pig. "3. Gkaphical Presentation of Data Contained in Tables
temperature T. Then, if we have C pounds of air with
each pound of steam condensed, the weight of mixture
to be pumped for each pound of steam is C (1 -\ — ^ ).
The theoretical work to compress this weight of
mixture, that is, the work required with an ideal air-
pump efficiency of 100 per cent., will be
D } k - 1
Wl=C(l +
RT
er-']
where pb is the barometric pressure and fr is the exponent
for the adiabatic compression of the mixture of steam
and air which may be taken equal to 1.41. To get the total
work of the air pump, Wt -f II'., we must add to \\\ the
work required to pump out the cooling water, which is
>" (?>b — p)
",
= "',
where Dz is the weight per cubic foot of the water and m
creasing the work of either of the two pumps; that is,
the vacuum may be improved by decreasing the tempera-
ture of the condenser by the use of more cooling water,
or by decreasing the pressure by speeding up the dry-air
pump. For a given vacuum, IT, will increase with a rise
in the temperature of the condenser, while II*., will de-
crease, and at a certain condenser temperature, depending
on the vacuum and on the temperature of the cooling
water. 11\ -f- Ws will be a minimum.
In Fig. 1 are shown variations in ]\\ and W2 for an
assumed air leakage of 0.62 per cent, of the weight of
.-team. As II', is proportional to the leakage of air, it
is easily found for any other amount. Since II'., varies
with the temperature of the cooling water (though ll*1
does not), different sets of curves are shown for tempera-
tures of 32, 50, 60, 70 and 80 deg. F.. each set consi
of three curves for vacuums of 25, 27 and 29 in. Bv
means of this diagram we have obtained by trial the
condenser temperatures which would make the total
: L6
r i ) \T E E
Vol. H, No. 22
air-pump work a minimum under various conditions.
The results are shown in Table I. With the temperature
of condenser known, we are in position to find values
ol n, which are also given in Table 1 and shown in Fig. 2.
TABLE I — Continued
Leakage
of Air,
in per
Cent, of
Weight of
Steam
0.00
Temper-
ature of
Cooling
Water,
Deg. F.
32
Temper-
ature of
Con-
denser,
Deg. F.
77
113
124
L32
113
124
132
113
124
132
100
109
113
104
111
114
Vacuum,
Inches of
Mercury
Total Work
Of
Air I'll m p.
in Ft. -Lb.
per
Pound
of Steam
710
21. S
IS. 2
14. S
12.0
100
L08
113
340
10.6
330
9.7
11S0
36.3
870
27.3
630
20.4
470
15.5
380
13.1
360
11.8
1900
7 -
1200
37.7
820
2:. .7
560
18.3
430
15.2
390
13.5
4500
140.0
1950
61.3
1110
34.9
700
22.fi
530
1S.0
440
I 5 . 6
5350
164.0
1740
54.3
910
29.5
660
22.0
530
18.7
2150
32.1
1560
25.6
12S0
21.7
1000
18.2
840
15.6
725
13.7
3300
55.0
2120
36.7
1650
30.2
1210
24.7
990
19.9
720
17.8
1820
89.8
2740
52.3
2000
37.9
1410
27.5
1120
22.6
930
18.7
S220
164.0
4010
7T. v
2670
52.2
1700
32. S
1280
25.2
1060
23.0
7750
164. 0
3930
70.0
2110
41.0
1530
31.8
1280
29.0
3010
40.0
2260
28.7
I860
25 1
1440
22.4
1200
17.4
1020
16.0
4600
66 5
2980
43.2
2310
33.1
1710
1390
21 .7
1190
IS. 5
6820
99.9
3700
61.9
2760
41.4
1960
30.1
1 560
25 6
1300
21.7
104H
::^s , ii
5440
82.8
3570
61.8
2300
39 6
ITT"
28.3
1450
25.5
L0040
165.0
5540
75 S
4890
49.4
2040
35.4
16S0
30.0
Total Work
I ,ea kage
of
of Air.
Temper-
Temper-
Air Pump,
in per
n n i .■ i.i
ai ure of
in Ft. -Lb.
Valu
Cent "i
Con-
Vacuum,
per
of
w eight ol
Water,
Inche
s of
Pound
Ratio
Stea in
Deg. F.
1 1. g [•■
Mercury
of Steam
m
0.93
32
5 5
29
3S40
42.7
62
2S
5
2SS0
32.. S
68
2s
2380
2 VII
73
27
1840
2 4 . :.
77
2fi
1 "..in
21.5
93
25
13111
16.5
50
64
29
r,7fio
70. S
71
2 s
5
3730
47.3
78
28
2920
35.5
S5
27
2i:.n
2 8 . 6
91
2fi
1760
24.:.
95
25
1480
22.4
60
68
29
8440
123.8
75
28
5
472M
66.0
82
2v
3450
45.1
ss
2 7
2440
35.7
96
26
I960
27.8
10 4
-•"'
1630
22.6
70
72
29
13250
494.0
SO
28
5
fifiio
98.8
86
28
4410
61.8
95
27
2S50
39.6
In London Engineering of Jan. 9. 1914, p. 38, is
given a diagram "due to J. M. Newton," showing values
nl in for various vacuums and initial temperature- of
Ling water. The effect of varying amounts of air
leakage i-. however, not shown as in Fig. 2 herewith.
In mu-T cases m would be easier to measure than the
average temperature of the mixture in the condenser and
could lie used as an indication of whether the dry- and
wet-air pumps were each doing its proper share of the
work.
To find the vacuum which will make the net work
a minimum, we must assume the water rate of the
turbine and the efficiency of the air pump. By net
work is meant the work developed per pound of steam
by the turbine, minus the air-pump work per pound of
steam needed to produce the vacuum. We have assumed
the turbine to be acting under 150 lb. gage pressure, dry
steam, without superheat, and have taken air-pump
efficiencies of 50, 65 and so per cent. Stodola assumed
for the air pump an efficiency of 50 per cent, and took
for the turbine an admission pressure of 142 lb. with
an initial temperature of 572 deg. F., or 218 deg.
superheat. Using, as he did, an indicated efficiency of
65 per cent, and a mechanical efficiency of 90, this
would l>e equivalent to assuming that the water rate
varied with the vacuum, as shown in Table II, which also
gives tin' water rates herewith employed.
TABLE 11
Water Ral •
Water Rate
Used
Value in
L'sed
Value in
by Stodola,
Ft.-Lb.
in Fig. 2,
Ft.-Lb.
Lb. per B.hp.
of 1 Lb.
Lb. per Blip.
of 1 Lb.
per Hour
ot Steam
per Hour
of Steam
14.0
63,300
18.5
17,900
13.5
65,600
17.6
ii. urn
12 8
69.1 'in
16.7
53,200
12.1
15.9
55,700
11.5
77,100
15.4
57,600
11.0
14.7
60,300
The writer has assumed that the turbine was designed
for a vacuum of 2? in. and that, consequently, the
efficiency decreases slightly from the maximum of 50.0
per cent, when the vacuum is either higher or lower than
the normal. The efficiencies are somewhat lower than
the constant value of 58.5 per cent, taken by Stodola
Jl
1, 1915
row Ei;
", i;
and apply more especially to small-sized turbines, while
his value would be more suitable for the Larger
Stodola assumed various rates of air leakage up to
aliout 150 eu.ft. per min. for a 1000-kw. turbine, and
found that with his assumed efficiency the mosi eco-
nomical vacuum was always over 2!) inches, increasing
with a decrease in the amount of air in the condenser.
He used a temperature of cooling water of 50 deg. F,
and a value of m = 50. Talile III shows the results
obtained with m having a variable value as in Table 1.
Where the most economical vacuum is different for two
different efficiencies of the air pump, both vacuums are
JUJST F©R FTLJM
TABLE III
Leakage Temper-
of Air in ature of
percent. Cooling Vacuum,
of Weight Water, Inches of
of Steam Deg. F.
0.00 32
50
60
Net work of Turbine in Ft.-Lb.
per Pound of Steam, with Air
Pump Efficiency In per Cent.
Equal to
:,ii
SO
50
Mercury
(Stodola)
29
58.S80
59,210
59,410
79,080
29
57,940
58,480
58,820
78,1 in
29
56,500
57,380
57,930
76,700
28.5
53,700
54. 1!n0
:,:,, n;n
73,200
2S
52,220
53,020
53,520
69,620
29
56,000
56,990
57,610
76,200
29
53,700
55,220
56,170
73,900
29
(50,660)
(52,870)
5 1,270
(70. still)
28.5
52.120
53,380
(54,170)
71,620
2S.5
( 19,580)
(51,430)
52,580
69,080
us
,0,360
1, /hi
(52,360)
(67,760)
is
(47,840)
( 19,650)
50,790
65,240
27
48,980
50,050
(50,560)
(04,880)
29
54.2S0
55,670
56,530
74,480
29
(51,100)
53,220
5 i. , ,n
71,300
28.5
51,640
(53,020)
(53,870)
(71,140)
28 .5
50,200
51,910
52,490
69,700
2 s .5
I 16,720)
i t9,2::ii)
(50,780)
i;«, 22<i
28
(4S.560)
50,210
51,230
(65,960)
18,600
( 19,660)
(50,320)
1 64, .-.OH)
27
47,420
48,750
49,590
63,320
0.93 32 29 52,620 54,390 55,500 72,820
50 29 (48,780) CI, 450) 53,100 (68,980)
50 28.5 50,140 51,860 (52,940) 69,640
60 28.5 (48,160) CO, 330) 51,700 67,660
60 28 48,800 50,390 (51,380) (66,200)
70 2S (46,880) 48,920 50,190 64,280
70 27 47, r,(iii (48,820) (49,640) (63,400)
SO 27 46,160 47,780 48,780 62,060
Note — Where the most economical vacuum is different for
two different efficiencies of the air pump, both vacuums are
driven, the values of the net work, which are not maximum,
being inclosed in parentheses.
included in the table, the values of the net work, which
are not maximum, being inclosed in parentheses. The
same results are shown graphically in Fig. 2 for air-pump
efficiency of 65 per cent. For cadi of the four amounts
of air leakage, from zero to 0.93 per cent., there are
five curves for the five different temperatures of cooling
water assumed. It will he seen that the most economical
vacuum is by no means always as high as 2!) in.
In the last column of Talile III is giveu the net work
of a turbine, assuming the same efficiency for the air
pump and the turbine as taken by Stodola, but taking
values of iii from Talile I. A comparison of columns
4 and 7, Table III, shows that a higher turbine efficiency
makes but little difference in the most advantageous
vacuum, so long as the efficiency of the air pump is the
same. In no case, however, would the most advantageous
vacuum, for given conditions, be as high as here calculated,
because no account has been taken of the cost of bringing
cooling water to the condenser, which increases with m
and hence with the vacuum.
Before Applying a Hydrostatic Te.st to any boiler, gagi
lines should be located and gages fixed in order to detect
any tendency to bulge or become distorted when under pres-
sure and show whether the parts return to their original
contour or not. Otherwise, the test will be of little value
or may even do serious damage, leading to failure later.
Such tests should be made by skilled and experienced men,
never by thoughtless amateurs.
A Painstaking Jon. hut in the W'uong Place
A green man taking down some circuits cut the wires
and instead of carefully separating the ends on the live
side he spliced the two lines together, then soldered and
taped the joint. That evening when it was time to turn
the current on thai line, things were lively for a while.
— Harry l>. Everett, Washington, D. ('.
What Is Ele< tricity?
I'm going to slip von one by Ike Hedges. He says:
"In the fall of 1913 I dropped oil at Bologna, Italy, on
my way from Venice to Florence. Consulting my Baede-
ker, 1 learned thai the famous thing about Bologna was
its ancient university, and thai three great men in the
electrical world had at one lime attended this famous
institution of learning — Galvani, Volta and Marconi.
The conclusion, therefore, is inevitable, that whatever
electricity may be, its basic principal is sausage." (Well,
it might be "wurst") — Terrell Croft, St. Louis, Mo.
A Livki.y Time
The second item in the "Just for Fun" column, Mar.
9 issue, reminded me of a similar incident.
The electrical system was being changed from a two-
to a three-wire system, and a temporary wooden switch-
board was being built above and to one side of the one
m use. The carpenter above was nobly trying to balance
a long piece of "two by four" that was slowly but surely
getting away from him. He yelled for help. His helper
below, a large steel square in his hand, realized the need
of quick action. He looked around for a place to lay
the square, and one of the main switches happened to
be the place. The action was quick. No one was serious-
ly hurt, though there was a most confusing mixup of
men, fire, noise and the "two by four." The helper, who
had vanished as though swallowed by the earth, "showed
up" four days later. — C. If. Dalrymple, New York.
"A Pound's a Pound the World Around"
I read your ".lust for Fun" column with considerable
pleasure and was particularly interested in an article in
the Feb. 23 issue, page 264, in which the member of the
school board made such wise remarks about the flow of
steam. It reminded me of a somewhat similar experience
while superintendent of a municipal plant in a mining
town in Illinois. After a new boiler bad been completely
installed the Village Hoard came down to the plant to
see it put under pressure. Among the various suggestions
for raising the necessary hydrostatic pressure, one was to
fill it full, close all vahes and build a light fire so that
the expansion of the water would give t be desired pressu re.
The idea was all light, only I explained to them that the
safety valve was set for only 150 Hi. and would blow at
that pressure, and would have tn have a gag on for the
test and thai I could pump up the pressure in a much less
time. One of the members, the owner and operator of
a steam-operated brick yard, said that it ought not to
lift at 150 lb. water pressure as l."i0 lb. steam pressure
was equal to 250 lb. water pressure and the valve wa
set for steam pressure. — W. J'. Martin, Connelton, Ind.
;-±s
P 0 w E i;
Vol. 41, No. 22
irstl Uimiiffiow Pfennt oi Ps^cJfic C©s\s4
SYNOPSIS The requirements demanded gener
ating sets capablt of providing elevator and light-
ing service without flickering lights and also to take
rare of a large roof sign which is thrown on and
< very thirty seconds. The engines and boilers
arc in a common room; there is no dust, as fuel
oil is burned in the boiler furnaces. The uniflow
engines on test with less than 150 lb. steam pres-
sure showed an average steam consumption from
one-fourth to full load of less than 20 lb. per in-
dicated horsepower-hour.
The power-plant equipment of the New Hotel Ros-
slyn, Los Angeles, Calif., presents the solution of an en-
gineering problem which will be of interest to engineers.
users i" purchase ii a1 a rate of approximately $0.0135
per kw.-hr.
The building was originally laid out with the inten-
tion of purchasing current, and therefore the space thai
could In- allotted to the power plant was very small. This
difficulty was largely overcome by the fact that oil-burn-
ing boilers were installed. The spare between the nearest
engine and the boilers would hardly permit the slicing of
tires if eoal were used lor fuel.
E. Ii. Ellingwood, consulting engineer, of Los Angeles,
was employed by the architects, Messrs. Parkinson &
Bergstrom, to make the plans for the power plant and
heating system.
Three "Universal Ohaflow" engines were selected,
two being of 200-kw. capacity at 200 r.p.m., and the
third of 100-kw. capacity at 225 r.p.m. (Fig. 1). Di-
Pig. 1. Oxe 100-Kw. and Two 200-K\v. "Universal Unaflow" Engines Directly Connected to Direct-
Current Generators
This hotel is 12 stories m height, with basement and
sub-basement, and contains, with an annex. 850 rooms.
There are four passenger and three service elevators,
of the high-speed traction type. It was required to
provide generating capacity that would take eare of the
elevators and lighting load from the same circuit with-
out causing the lights to flicker. Clusters of tungsten
lamps against light-colored ceilings and walls were to be
used, which would have a tendency to magnify the least
flickering of the lights.
In addition to the fluctuating elevator load, provi-
sion also had to he made to take care of a large roof sign
which was to be thrown entirely off and on at intervals
of 30 sec. Besides being able to cope successfully with
the fluctuating nature of the load, the plant had to he
an economical one. because electricity in Los Angeles
is sold on a sliding scale, making it possible for large
reet-current three-wire generators were selected. The
boiler plani consists of three L96-hp. water-tube boilers
(Fig. 2). equipped for the burning of fuel-oil. The
steam pressure is 150 11). at the boilers. Saturated
steam is employed. The engines oil a test at somewhat
lower steam pressure than 150 lb. showed an average
steam consumption from one-fourth to full load of less
than 20 lb. per i.hp.-hr. The plant is a good invest-
ment for the owners of the hotel, as the total cost id'
operation, including interest, depreciation and a charge
of $0.50 per sq.ft. per y^ar for floor space, is $0.011(i
per kw.-hr.
The total connected load is about 760 kw.. of which
260 kw. is motor load; and although this is of a decid-
edly fluctuating nature, owing to the trait ion elevators
and the intermittent electric sign, no flickering of the
lights in any part of the building can be noticed.
June 1. 1915
P 0 W E i;
; id
Tl ngines and boilers will attract the attention of
asters engineers, owing to the fad thai they are placed
l one room, which is finished in white. This arrange-
iriit is possible and practicable on account of burning
lel-oil under tin' boilers. The engine and boiler room
i> well lighted by 200-watt tungsten lamps suspended
close tn the ceiling. Fig. '■'< is a view of the switchboard,
which is also shown in part in Figs. 1 and 2.
In addition to the power plant, there is a refrigerat-
ing svstcm calculated to provide circulating water in
every room at a temperature of ■'5'; deg. P., the test con-
ditions being rigid, as only 8 oz. of water was allowed to
lie drawn from the faucets in order to arrive at the test
temperature of the water. The refrigerating equipment
Fig. 2. Three 196-Hp. Water-Tube Boilers; Fuel
On. Is Used in the Furnaces
Fig. o. Switchboard fob <ii neratob and Circuit
( Iontrol
consists of one 18-ton horizontal ammonia compressor,
direct-driven by a Corliss engine at GO r.p.m. The plant
manufactures 1200 lb. of ice every 24 hours, and fur-
nishes refrigeration I'm- all cold boxes in the storage de-
partment of the hotel, the liar, the cigar and flower shops.
4=M
1 ,~T" il_J | ;"- 3 I TANK PUMPS
:?5
BOILER FEED PUMPS
IK PUMPS U
:
A
A = Separating Tank
B" 5' "Sump Vent
C = Sand Trap
D= 8'l.P Steam to Present heating
System and 3/ast Coils
O O"
FILTERS** '
'FILTERS
CIRCULATING
PUMP j^_
MOT WATER TANK
3SS*
I
'-.FEED WATER J V>
HEATER P) ■
-'" J . .
CONNECTION AT-X
Fig. I. Plan of Kxoixk axd Boilki; Room
;:,(>
POW E I!
Vol. 41, No. 2%
PRINCIPAL EQUIPMENT OF THE
No. Equipment Kind Size Use
2 Engines Universal Unanow. . . 200-kw. Main unite
1 Engine. Universal LnaHmv lllll-kw. Main unit
Diri 200-kw. Main units
i Direct-current. 190-kw. Main unit
Water-tube 196-hp., St. -am generators.
\tiuiioiiia . l.N-tun.. UrfriL'i-iation system
1 Engine. Corliss.. Driving ammonia compressor
1 Pump.. Tank Water to storage tank .
2 Heaters .Tank Hot water for house
>r the 1 iuild using exhaust steam,
Ventilating >ystem, exhaust fans,
Water for lavatory, laundry and kitchen purposes is
heated in a battery of two combination tank heaters
thermostatically controlled, the water being circulated
throughout the building by centrifugal pumps. The
water-supply for the building is Erom roof storage tanks
of 34,000 gal. capacity, automatically filled by a steam-
driven tank pump located in the sub-basement.
Steam heat for the building i by means of a system
using exhaust steam exclusively.
The ventilation in the service department, lobby and
dining room and the exhaust ventilation from all the
toilets, lavatory and bath systems is provided by fans.
The water for refrigerator, laundry and boiler-room
i^e is treated by the lime and soda process, as Los An-
geles city water runs from •.,'.) to 26 deg. German hard-
ness.
The compact nature of this plant, as shown by the
plan, Pig. I. was necessary on account of the limited
tl • space turned over to the engineer for the installa-
tion of the equipment.
ILualtlwiielesr ©©•vialblie^Acttiifiig*
At the factory of the Luitwieler Pumping Engine Co.,
Rochester. N. Y., may be seen a double-acting triplex
pump operating at speeds from 100 to 300 r.p.m. The
HOTEL ROSSLYN, LOS ANGELES
Operating Conditions Maker
200 r.p.m , 150 II' team, saturated Skinner Engine Co.
2\!~> r.p.m., 150 lb. steam, saturated Skinner Engine Co.
200 r.] three-wire system ( Iroeker-Wheeler Co.
;n , tiir,-, -win- sVst, in Crocker-Wheeler Co.
Engii
n, 66 r p ... . 12001b
I : i team, 66r p.m .
i : o taticaliy controlled.
Badeniiausen Boiler Co.
Vulcan Iron Works.
Murray Iron Works
Henry U. Worthington
Frank L. Patterson
I' A Dunham Co.
I'. I'\ Sturt.vaiit ' 'o.
Pump Running While liEsTixn on Rolls
illustration shows the pump operating upon a pair of pol-
ished steel rollers 2 in. diameter, the rollers resting on
the top of a table. There is no air chamber on the pump
and the gage needle' stands still, showing that the water
pressure is constant. To show that no vibration exists,
a wire nail •"> in. long stands motionless upon the top of
the pump; on either side of the rollers other nails of the
same size stand on <-\n\ touching them. If there was any
moverj i of the rollers the nails would topple over, but
the pump operates at these high speeds day after day
with the same nails standing immovable.
The Luitwieler pump was described on page 53 of the
July s. 1913, issue. All the driving mechanism is in-
closed in a hath of oil and i ds practically no attention.
OlsjaeirasaoiraSp Wengphfts E&inidl Costs
©f Sttesysim Tua5p3bimi©s*
By A. A. PoTTERf .\xi> S. L. SimmeringJ
Tables 1 ami 2 were compiled from data supplied by
manufacturers and should prove of value in connection
with preliminary estimates. The dimensions, weights and
cost tlata are for condensing units ami include the tur-
bines and alternating-current generators.
The values in Table 2 were plotted and the following
equations were deduced, giving the cost in dollars (C)
of the turbine and generator, in terms of the capacity in
kilowatts.
Impulse ////us C = 5040 -f- 9.2kw. (Dollars)
Recti lion types C = 7400 -f- 8.26 lew. (Dollars)
Size
Lgth.
Will tit Hght.
Weight
Lgth. Width Hght
Weight
Kw.
ft. in.
ft.
ni. ft. in.
Lb.
ft. in. ft. in
ft. in.
Lb.
300
IT, 111
5
0 5 4
18,500
16 0 6 0
24.000
:;iiii
20 0 6 0
5 10
37.900
500
18 0 6 0
30.000
500
16 1
3 6 6
34,800
20 9 6 0
5 10
42. tain
1000
24 0 6 0
60.000
1000
1.; 11
6
10 7 0
45,000
IS 4 6 9
6 S
52,250
2000
i'ii r,
9
0 7 9
75,000
25 6 9 4
7 9
105.000
2000
26 0 7 0
'11'.
5 )
25 1
in
7 9 S
175.000
34 9 11 5
9 1
236,1
50 ml
34 0 SO
190,000
10000
32 5
12
'.' 12 n
310.000
45 0 10 0
320,000
TABLE 2 — COST
OF CONDENSING
STEAM TURBINES AND
GENERATORS
t — Impulse
Type— s
, — Reaction Type — ,
Si
ze, Kw.
It. p.m.
( 'est
R.p.m.
Cost
300
3600
$8,000
3600
$7,650
:,no
;;i;iii.
9,600
3600
9,550
1000
3600
14.000
3600
13,750
2000
::i;imi
23,000
3600
22.800
5000
1S00
55,000
3600
48,7
00
10000
1800
95,000
1800
90,000
Duty of n I'niii; — There are different definitions for what
is termed the "duty of a pump," each giving a different esti-
mate or value. The duty is sometimes defined as the weight
(lb.) of water raised through a vertical height of 1 ft. for
each 100 lb. of coal burned; or, more simply, the theoretical
work (ft. -lb.) performed per hundredweight of coal burned
under the boiler. It is observed that this definition is faulty,
because it combines furnace and boiler efficiencies with that
of the pump itself, besides estimating only the theoretical
work performed, thus eliminating friction, which is often a
most important factor. The true definition of duty in pump-
ing is the actual work performed in a given time (ft. -lb.), per
million B.t.u. delivered to the pump in the same time. Or.
less frequently, the duty is estimated in foot-pounds of work
performed per thousand pattnds of dry saturated steam con-
sumed.— "Coal Age.'
♦Copyright, 1915, by A. A. Potter and S. L. Simmering.
tl'rofessor of steam and gas engineering, Kansas State
Agricultural College.
{Instructor in steam and gas engineering, Kansas state
Agricultural College.
June 1, 1915
POWE E
751
ll.ii! . I'l!'
I!!. I!
.'!' ',. ' !!';!'! I. I:. . :
aiiiiiliiiiiliiiiiini minim ' mmiii iiniinii ni
Always present in every community arc the ""kill-joys. '
who set- nothing but ruin ahead if this or that is done.
Yet somehow, we always have lived through the admin-
istrations that were prophesied to bring the country to
disaster and, strangely enough, we are getting better all
the time. It seems as though progress has a certain
momentum that will carry it on in spite of all obstacles,
including the well-meaning people who cannot anticipate
success except by time-worn methods.
In this connection a recent utterance of George Otis
Smith, director of the United States Geological Survey,
in an address at the University of Illinois, is to the point :
The trouble with oo many of the business men of the day,
and especially with those who come to Washington to oppose
new legislation, is their nearsightedness. They cannot see
country-wide public opinion and do not appreciate the obvious
fact that the financial centers are not also the centers of
national thought. The result of this, as I expressed it in con-
versation last winter with a New York gentleman who was
largely interested in water-power development, is that the
business interests oppose something at one Congress which
two years later they would accept; but the next Congress is
already considering a more advanced legislative proposition.
We are all more or less progressive, I told him, but the
opposition has been just one lap behind.
The bright light of publicity is coming to shine more and
more upon the inner workings of all private business which
has anything of the public-service character. Only about
three years ago, at a conference on water-power policy, I
heard the representative of the banking houses interested
in the hydro-electric business tell the Secretary of the In-
terior, with considerable warmth of spirit, that one thing the
men who make possible the development of our country by
their contribution of capital would not stand for was any
legal requirement of inspection of their accounts by the Gov-
ernment. A corporation has its rights, they contended, just
the same as a private man in business. Last year in the
same room, when the utilization of a large power site owned
by the Government was being discussed, I heard those asking
Cor the permit dismiss the question of Federal inspection of
their books with the remark, "That need not be discussed, our
books will of course be always open to any authorized rep-
resentative of the Government." The ultimatums pronounced
by the ambassadors from Wall Street, State Street and West
Adams Street are short-lived in the present atmosphere of
popular interest in these business questions.
To go back to our first thought that progress is going
to "get there" '•nevertheless and notwithstanding," the
situation is much like that of a trolley car or automobile
trying to cross a busy street. People and traffic will
continue to hold up the car by passing in front of it
like so many obstructionists until the Law. personified
in the traffic "cop," gives the car the sign to come ahead.
Then the pedestrians have to look out for themselves and
let the car pass. The car loses a little time, and so do
the people, but eventually all get on and no harm is done.
So it will be with the questions that Congress or State
Legislatures arc called upon to decide. Ultimately, they
will be settled the right way, and the sooner opposition
is withdrawn the sooner conditions will adjust themselves
to everyone's satisfaction. Right is the good of the
majority, and private interests mindful only of their
profit will do well to accept the inevitable without ex-
pensive delay. It is futile to hinder progress.
To most engineers the study of principles is less inter-
esting than apparatus embodying them — details of valves,
piping, generators, etc., grip the attention far more read-
ily than what look to be theoretical abstractions. This
is only natural, for most people think in concrete terms;
the specific appeals to the intellect of the great majority
more than does the general ; and iron and steel, water and
coal, copper wire and insulation, belong so positively to
the realm of things seen and handled that many minds
never get much beyond these visual conceptions.
Mastery of details is essential to engineering success, but
advancement to professional standing calls for recognition
of principles. We hear too much about the "man behind
the throttle," as though mere manipulation were the in-
dex of the engineer's ability. Striking phrases like these
are useful in their place, but are largely figures of speech,
and their symbolism should not be taken too literally.
Without brains to guide the hand on the throttle, to ap-
preciate what goes on on each side of the valve disk, and
to anticipate in imagination the results of various steps
in plant operation, we should have short shrift from the
business world. Power to think in terms of principles — to
theorize — is the means to rise out of mediocrity into dis-
tinction. Acquiring it means drudgery and plenty of it,
but it also means advancement on a solid foundation, with
a broad comprehension of the significance of details which
mere cleverness in mastering the latter can never supply.
Appreciation of the laws of steam, hydraulics and elec-
tricity, knowledge of the strength of materials and com-
prehension of the chemical and physical principles bear-
ing upon combustion of fuel, the production of steam or
producer gas, a broad grasp of the elements of lubrication
and of the essentials of heat phenomena, will serve the
engineer well in time of need. It goes without saying that
to understand the why of his work as well as the how,
these important matters cannot be neglected. Even after
a man has gone through a rigorous course in mechanical
engineering and spent several years in practice within the
plant, it will pay him to occasionally review the funda-
mentals of his profession. Defects in early training can
thus be remedied, and most of us have weak spots in our
technical armor.
In these days of distributed information, with interest-
ing bulletins and catalogs coming from all quarters of the
land at the price of a postal card, it is easy to form the
habit of following applications of principles to the exclu-
sion of studying fundamentals themselves. It is amaz-
ing how helpful it is to review the element- of steam engi-
neering, for example. Much of the matter can be gone
through rapidly, but such a review strengthens the grasp
of the reader on the great essentials of his occupation and
thereby better fits him to grapple with fresh problems
in his own field. Judgment in the application of these
principles is developed as the seasoned operating man re-
freshes his mind again and again with the foundations
of his profession; the true significance of detailed prac-
P o w F. n
Vol. 41. X... 22
tire becomes more apparent, and the ambitious worker
thus prepares himself tor greater responsibilities ami
more accurate dei isions.
'&.
General industrial activity makes for our prosperity as
a nation. If the shops ami mills are inactive, this depres-
sion affects all seriously, including the operating enginei r,
whose function it is to keep the power wheels in motion.
As the time approaches for the convening of the two
-t organizations of operating engineers in America,
it is to be hoped that, with their avowed objects for gen-
eral good and their tremendous possibilities for advance-
ment in knowledge and prosperity, they will give some
heed to the upset and unrest of business conditions and
find means to cooperate with the commercial interests in
seeking a remedy.
While the war has had its influence, helping some busi-
ness although hurting most, il would not account for so
much idleness when the crops are big and their prices
high, when our financial condition is strong, and when
labor and capital were never so willing to cooperate.
Conservatism, or in other words, lack of confidence seems
to be the trouble. It is a time when the cautious are very
slow about taking even the slightest risks.
One contributing cause of tin- uncertainty ami fear i-
that honest business interests are in doubt as to just what
they can do lawfully in the face of so much new and un-
tried legislation. They do not know how to conduct
their affairs in accordance with laws that are apparently
interpreted one way today and another tomorrow, con-
sequently, some have ceased to do business; their plant-;
are closed and their employees idle. A wild '•touting on
the horn of plenty" is merely noise, not a remedy, nor is
the "popular' legislation of those politicians who are
actuated by narrow ami sordid self-interest. Our in-
dustrial prosperity furnishes the sinews of our citizenship,
and our membership in the engineering organizations
gives us ample authority to work in every legitimate way
fur those interests. No one influence ha- been so power-
ful as that of the engineers in placing wise boiler laws on
the statute books, in safeguarding lives and property
against criminal operation of power plants, and in fram-
ing the license laws governing our fellows. Is it not
time, then, that we voice our protest against unwise i
lation, investigation and control wherever and whenever
it affects us? Our Government i- a government of the
people; we have a part in it. It i- sovereign in its power
to so adjust ami fix conditions that we. the people, may
enjov the honest activity in our vocations, which is our
right.
We need a much wider publicity for each proposed
legislative measure, whether h affects our field directly or
only indirectly. Therefore, we believe that every organ-
ization whose purpose it is to uplift ami promote the in-
terests of its members should have timely knowleds
proposed laws, and when affected by them should have
the chance to express it- approval or disapproval.
Cuaftftami^ 00IL'vyiinm]b©2;>I>0 ©tmte of
Ability to write a clear-cut, straightforward report
unencumbered with superfluous material is worth culti-
vating. Many an operating engineer would Iread the task
of preparing a report, for instance, on the desirability
of replacing a vertical cross-compound engine with a tur-
bine. Usually, it is not so much the engineering pro
as the literary end of the work that looks burdensome.
Sound figuring is demanded first of all, but if the correct
conclusion is reached there should be little further anxiety.
The form of report desired will depend on the employer,
but most busy men want a terse, clear statement of eon-
elusions, to which they can turn at once. While it is
proper to include it. the reasoning upon which the recom-
mendation is based is secondary. It is very easy to
encumber a report with useless description and discussion.
Such matter has appropriately been called "lumber" by
an engineei experienced in scanning written matter, and
good judgment in eliminating it is profitable.
In the ease mentioned, a well-considered report might
follow a statement of the problem in hand, with the
conclusion that it will pay to make the change and that
the annual saving would be about a certain sum. The
rest of tin report may then he an appendix in support of
the contention.
The argumentative part of the report might include a
statement of the capacity and service of the equipment
displaced ami the present operating costs and fixed
charges, takii - care to mention all assumed factors, like
the pi of interest, insurance and depreciation
allowed. Test data on which existing cost figures are
based maj be summarized, and the limitations of the
equipment in point of space, in meeting a growing load.
etc.. discussed. Then should follow an estimate of the
cosl of substituting a unit of increased capacity, with
the fixed charges and estimated operating cost, with the
statement of authority for steam consumptions assumed,
guarantees offered, etc., and a final tabulation of yearly
cosl o a stated service, with a checking of the total
againsl sent total if desired, or a comparison of
unit expense- at the busbar. Modifications in auxiliary
plant should also be covered in their proper places.
Tn presenting such information literary style will
largely take care of itself if the report is logical and
intelligible at all points. If it lacks clearness, if it cannot
lie checked by another competi nt engineer without con-
sulting the writer, if it includes long and rambling
accounts of possible equipment combinations without
predicting definite results, and if it fails to concentrate
similar information effectively, the force of the engineer's
recommendations may be greatly weakened.
It is the technical judgment of the engineer that the
employer values, and the selections of factors, the arith-
metical processes and methods adopted concern him less.
To an extent, the less language a report contains, the
more helpful it will be to the employer's decision.
In January, 1909, a half dozen year- ago, President
ell w role :
The people of the country are threatened by a monopoly
far more powerful, because in far closer touch with their
domestic and industrial life, than anything known in our
experience. A single generation will see the exhaustion of
our natural resources of oU and gas and such a rise in the
price of coal as will make fhe price of electrically transmitted
water power a controlling factor in transportation, in manu-
facturing and in household lighting r.nd heating.
And it -till threatens: witness the defeat by it- pro-
ponents of administrative water-power legislation in the
late Congress.
June 1, 1915
POW E B 75:;
iiiimitiiintiii iiiixiu nana mm «"" "i""™ ■ ' Ilin11111 IN"" Il1""" "'" """""" """' """" '""" ""' """ """"'"""" """'""
,„„„„, ,„„ a mm mail m inn mm i i ■ mm i i ■ - mmn urn ■ ■ ■ ■ ■ ■
the working fluid, ad reproduces and is exactly parallel
to be. The heat converted into work is proportional to the
area abed, or its equivalent as a rectangle abmn. The
heat rejected in the cycle consists of two parts represented
by the areas edd'e' and bec'b'. The latter is exactly equal
to the heat required to carry out the process da. If, in
the course of rejection of heat along be and the drop of
temperature from T + dT to T a means is provided
for storage of this heat and the maintenance of such tem-
Tlheore^ac^E EiBfitcaeimcy of Heafc
I£>imjg|lE&©s
The article by Mr. Heck in the issue of Apr. 30, con-
cerning "Theoretical Efficiency of Heat Engines," con-
tains a reference to an earlier statement by myself in
Powbk of June 9, 1914. In general, the detailed analysis
of the problem by Mr. Heck is entitled to unqualified ap-
proval, were it not for the risk that some of the inferences
might contaminate the future bibliography on the effi-
ciency of heat engines because of an incomplete quotation
of my remarks. The omission of the dosing sentence of
the paragraph to which reference is made is herewith
supplied: '-This (53.3$ I cannol be approached on ac-
count of practical limitations.'" This would seem to be
sufficient reassurance that 1 am not disposed to attach
any value to the perfect gas formula as an indication of
the attainable performance of heat engines.
In stating the "perfect gas" formula as a limit, I am
not only sale, but also following the practice of authori-
ties in thermodynamics sufficiently to remove the second
law, for which the formula is simply an algebraic expres-
sion, from the realm of discussion. There may he other
and lower limits for particular operations, but they do not
serve as a means of disproving the validity of the Carnot
cycle as one of limiting high efficiency . Nor do they estab-
lish "ideal steam cycles,'' as there are alternatives to the
Rankine cycle which surpass it in efficiency.
There is a process, as indicated by Boulvin in 1897 and
reproduced in the translation by Bryan Donkin of "The
Entropy Diagram and Its Applications," which produces
a working cycle for any fluid, including steam, attended
by a higher efficiency than that of the Rankine cycle.
In fact, carried to the limit it would have the same effi-
ciency as the Carnot cycle, theoretically. In order to avoid
a further misinterpretation I will now insist that this
cycle, like that of the Carnot, cannot be completely real-
ized on account of practical limitations. Nevertheless,
an incomplete process can be devised and has actually
been applied with noticeable improvements over the Ran-
kine cvcle.
Referring to the entropy diagram Fig. 1 (Fig. 7, Boul-
vin-Donkin) as reproduced without reference to a scale,
ab and cd are isothermal lines, be is an arbitrary path of
Fig. 2
peratures, it may with adequate equipment be applied to
the heating of the fluid at a certain part of the path da
without the intervention of a source of heat. The heat
stored is represented by bec'b' and is returned to the fluid
as the area d'daa'. The efficiency of the cycle is the ratio
abed abmn
d'dabec' a' abb'
E =
Since an infinite number of heat reservoirs cannot be ap-
plied, the theoretical limits of the cycle cannot be realized.
But a modified adaptation of a limited number of regen-
erators or heat reservoirs, each operating in a particular
temperature range, can he applied, with the result that
the limit of thermal efficiency may be considerably higher
than that of the simple Rankine cycle. The latter is not,
therefore, an "ideal steam cycle."
Referring to Fig. 2 (Fig. 8, Boulvin-Donkin ) : replace
the continuous line be by the broken line b I .' 3 i 5 c and
the line da by a similar broken line d6 i 89 10 a and we
have a cycle having the same efficiency as the Carnot and
which may be designated as a system for "regenerative"
feed heating. The essential features of this cycle consist
of abstraction of heat from the steam during its transit
through a multiple-expansion engine and a successive
higher heating of the feed water in a number of closed
heaters, transferring their heat at different temperatures
between T, and T .. For example, the heat absorbed dur-
ing the operation 7 .' .', $ and between the temperatures
T. and Tt is transferred to the feed water after it has
been heated to the temperature T3 and through the part
7 8 9 10 of the cycle. A perfect storage and restorage of
heat in this manner is impossible, but a move in that di-
rection, with highly gratifying results thermodynamically.
lips been made in the case of the multiple-expansion pump-
ing engine for the Wildwood station of the City of Pitts-
burgh and devised by B. V. Nordberg.
754
POWER
Vol. 41, No. 22
A simple addition of but two elements of this regenera-
tive feed-heating process is capable of such improvement
of the Rankine cycle and of the illustrative example pro-
posed by Mr. Heck that his figure of 0.335 for thermo-
dynamic efficiency is too low and is not therefore an "ideal
steam cycle." Moreover, the limitation of saturated-steam
temperatures to 380 deg. F. is one which engineers need
not hesitate to transgress, as pressures of TOO lb. per sq.in.
and more on certain types of small boilers have been ap-
plied without calamity. The rapid improvements in the
construction of steam turbines reveal that their de-i:
are possessed of sufficient courage to venture on even to
the utilization of a modified regenerative feed heating
to further improve the cycle of operations, when, if ever,
we may hope for a near approach to the realization of an
efficiency indicated by the "perfect gas formula."
F. 6. Gasche.
South Chicago, 111.
Ptunnmp 1BL<E
The owner of a greenhouse wished to install a gas-
engine-driven pump for watering. To provide for future
demands for more water, and to avoid excessive pressure
if the demand should decrease while the pump was be-
ing operated, it was necessary to provide for controlling
the flow by means of the variation in pressure.
An ordinary single-seated back-pressure valve with
outside dashpot was purchased and remodeled, the dash-
pot being placed on the opposite side so that pressure
Piping of Regulatob
under the piston tended to close the valve. A common
lever safety valve was connected to the discharge pipe
near the tank, with its discharge leading through a ^-in.
pipe to the bottom of the dashpot. A drip-cock was
placed in this line for relieving the pressure, but it was
not necessary.
In operation, when the pressure exceeds that for which
the safety valve is set, the valve opens and admits water
under pressure to the dashpot. This raises the lever
and weight and closes the valve. The pump then runs
idle until the pressure in the tank falls and the safety
valve closes. The slight leak around the stem of the
safety valve relieves the pressure and the suction valve
opens, due to the weight.
The pipe leading to the safety valve is extended nearly
to the bottom of the tank to avoid loss of air, which would
leak much faster than water if the seat of the valve should
become worn.
To prevent the pump from becoming air-bound when
running idle, it was necessary to drill and tap the water
passages at the ends of the cylinder and connect check
valves. The discharge from these was run through a
globe valve to the hopper of the engine, and the overflow
led to the sewer. This gives the engine cooling water
in sufficient quantities when the pump is working,
and the water in the hopper is sufficient for cooling when
the pump is running idle.
The device will operate to open or close the suction
with a variation of 5 to 0 lb.
A. H. BULLARD.
Syracuse, X. Y.
^©weiatlainiM Wanes' !nIa^IMnl©^!, lira
Regarding the suggestion of a safety valve on the blow-
off line by Mr. Fenwick in the issue of May 11, page 650,
and the editor's comment that the boiler might be drained
of water should the safety valve on the boiler become slug-
gish, there is little likelihood of the valve opening at all
after it has been in use a short time. Such has been my
personal experience with safety valves on hot-water out-
lets, unless moved off their seat every day.
A safety valve will work on cold water, air and steam,
but if hot water containing even a small quantity of lime
or other scale-forming material is allowed to pass through
it, the valve will become so attached to the seat that it may
require a sharp blow to loosen it after the spring is re-
moved. The surest way of preventing water hammer is
to use two valves — one a slow-operating screw stem and
the other a quick-operating one if desired — and always
open the quick-acting and close the slow-acting valve first.
James E. Xoble.
Toronto, Out., Canada.
35
nM ILeevIfe isa Sweater T^slbe
By exploring with a lighted candle over the tops of the
tubes in a vertical-tube heater under slight pressure, it
was found that one was leaking. The candle would be
instantly extinguished when held over the leaking tube,
but not when held over the others. By sliding a wad of
waste into the tube on a wire it was determined that the
leak was about half-way down. The heater could not be
spared long enough to put in a new tube. The question
was how to stop the leak. To plug the tube in the usual
way the heater would have to be taken down to get at
both ends.
The first attempt consisted in driving into the tube
each side of the leak a wood plug long enough to reach
the heater heads at both ends. This did little good.
Xcxt. a quantity of Smooth-On cement was put on top
of the plug below the leak, another plug driven in, with its
top above the leak, more Smooth-On cement added, with,
still another plug on top extending to the upper head.
Had sufficient time been allowed for the cement to harden,
this plan would probably have been successful, but the tube
got to leaking again after a time.
The trouble was finally stopped as follows : A plug
long enough to reach to the bottom head of the heater was
driven below the leak and a quantity of molten babbitt was
poured in and tamped tight with an iron bar. Then an-
June 1, 1915
P 0 WEE
755
other plug long enough to reach from the babbitt already
in to a point above the leak was driven in, and more bab-
bitt was poured and tamped. A plug reaching to the top
head was then put in, and the leak was effectually stopped.
G. E. Miles.
Denver, Colo.
18
IR©©©2"^©nss Hiadlacsiftlinig €ssig|©
Originally, the only way of telling the amount of water
in our 17,500-gal. reservoir was by going out and looking
down into it. In summer it was not so bad, but when the
thermometer registered 40 deg. below zero it was different.
I constructed a gage to indicate the water level, which
works to perfection. On a lx6-in. board, the length of
which corresponded to the depth of the reservoir, I fast-
ened two pieces of 2-in. maple flooring E with their
grooves facing each other. A block D, to slide freely in
the grooves, is fastened to a light rod II , and on the end
of this rod is a float F. A 3-in. pipe is used for the float to
work in, and this extends down to the level of the bottom
of the reservoir. A %-in. pipe connects the 3-in. pipe to
the suction pipe 67 (or to the bottom of the reservoir
itself) and maintains the same water level in the 3-in.
pipe as that in the reservoir. To the block D are fastened
springs / and J, and to the top and bottom of the board
Indicator axd Alarm
are fastened contacts C and (" . At the top a bell is placed
connected to batteries B. The gage is graduated in feet
and inches and is so marked that the reading corresponds
with the height of water in the reservoir.
When the reservoir is full the spring / on the block
makes contact with C at the top, completing the circuit
and ringing the bell, and at the bottom a similar con-
tact is made when the water is low. The wiring is con-
cealed behind the gage board, and a switch can be used
to cut out the bell.
The gage is located in the most convenient place and
wired so that the bell may be where the operators are
most likely to hear it.
Thomas K. Lee.
Benson, Minn.
T@ Pjpeveimtl €2Jg\.g£©° Glass©®
Anyone troubled with separator glasses breaking should
make a drop or trap in the bottom connection so as to
form a water seal. This will stop the flow of steam
Water Seal in Gage Connection
in the glass. The drop needs to be only from 3 to 6 in.
The illustration shows the application of the idea.
Fred W. Schneider.
Clay Center, Ohio.
§5
§&©sitnm PsresstuiE'es aurac
Sp©edl
'astona
The editorial on page 548 of the Apr. 20 issue very
properly called the attention of the operating engineer
to the increased hazard in engine operation today, as
compared with twenty years ago, due to the increase in
the steam pressures used. I had thought to criticize this
editorial, because it did not take account of the fact
that during the time steam pressures have been mounting
higher and higher the demand for closer regulation for
electric-light engines has increased, and in order to meet
this demand for closer governing the weight of the fly-
wheel has steadily increased.
The increased weight of flywheels has acted, of course,
to retard the speeding up of the engine when the gov-
ernor lost control, and this, in some measure, has acted
to counteract the effect of the higher steam pressure
tending to hasten the approach of the bursting speed
in case of accident. I hesitated about sending such a
criticism in, because it requires considerable temerity to
take issue with an editor and I was not so sure that I
was altogether right, not holding a first-class engineer's
license; but since I have seen the remarks on this same
editorial by Air. Williams on page 585 of the Apr. 37
issue, I am willing to take a chance.
How a change in engine design during the last 25
years so that a working piston speed of 600 ft. per min.
has been made 900 ft. per min. — or if made 9000 ft.
per min. — could have such effect on the safety of fly-
wheel operation as pointed out in Mr. Williams' article,
is more than I can understand. Calling attention to the
:.v,
P 0 W E E
Vol. II, No. 22
high piston speed of the modern engine as a factor con-
tributing to flywheel accidents seems about on a par
with figuring the explosive energy in a boiler from the
number of pounds of coal burned per square foot of
grate surface. Will not Mr. Williams enlighten us fur-
ther on how high piston speed affei t- the safety of the
flywheel ?
A. K. Jones.
Melrose, Mass.
?!
Steasim Coal aira Ws*.ft©sr TanraM
The illustration shows a large water-supply tank. It
is exposed, that is, it is erected outside and elevated GO
ft. from the ground: the water is pumped by motor or
windmill from a river some distance away. The pipes to
and from the tank are run underground in a waterproof
Sidle
era
Steam Connections to the Watek Tank
box. The pipe A carries the exhaust from three duplex
steam pumps, one of which is always working and some-
times all three are in service. A separator B that removes
water and oil from the steam is provided, and another. C,
which removes the oil from the condensate, so the clean
water flows along pipe D and discharges into the hotwell;
the oil is discharged into a filter. The exhaust riser
runs to the tank, where it enters a coil surrounded by the
tank water.
Where the pipe passes from the building to tin tank
it is covered for protection from frost and cold. The
steam in the coil keeps the water in the tank from freez-
ing. The water is used for domestic service as well as for
the power plant, therefore the exhaust steam could not
be discharged directly into it. The water in the pipes
or tank has not fro/en. although the outside temperature
has been as low as -'id deg. F. below zero. A relief valve
was attached to the exhaust pipe near the pumps to pro-
vide for any possibility of a stoppage in the coil or else-
where.
.T a vies E. Noble.
Toronto. Ont.
The
Dealer,
stoker
use it.
following .lipping from the Cleveland Plain
I believe, expresses the true inward feeling of the
in a moment of resentment. You may care to
Our muscles ache from stretch and strain,
Our eyes are sore with salty sweat;
Our blistered skins are gnawed with pain,
Our souls, the Devil claims for debt.
Before us there a gage is set —
The only oriflamme w'e know!
Above, they fight the foe we've met —
Who gives a damn for us below?
The great guns boom across the main,
The Steam Boss comes with curse and threat.
We stuff the hot, red maws in vain
Another pound of steam to get!
With senses taut, we toil and fret
And wonder how our fortunes go.
Above, we know they battle yet —
Who gives a damn for us below?
A crash — a rear — and cries profane!
We slip, we sprawl — our floors are wet!
The bulkheads close, and we — remain!
The Steam Boss lights a cigarette.
The hot steam scalds, the waves abet —
ok* — we die — we have no show-
To save the rest! But Where's regret?
Who gives a damn for us below?
Prince! And you of the epaulet!
The world on you will praise bestow,
From Admiral to young Cadet.
(Who gives a damn for us below? i. — Planchette.
William 1). Taylou.
Lorain, < >hio.
In a recent issue it is stated that boiler inspectors do
not always report defects, to which statement I agree.
We have state inspection here, but it seems as if the main
thing i- to get the inspection fee. I have been inspecting
boilers for some time for various companies and have
followed both the state and insurance-company inspection
in various plants.
In one plant in New Mexico 1 was sent to inspect three
horizontal-tubular boilers carrying 150 lb. pressure that
had been inspected about fifteen days before. The follow-
ing defects were found: A handwheel was gone on a
water-gage cock : three wheel- missing on the gage-glass
imks; brickwork on all the boilers in bad shape; a 6-in.
globe valve had a hole in the body, over which a piece of
packing was clamped to stop the leak; the pressure gages
had not been tested for three years: some flues were
leaking on all of the boilers at the back head, and two of
the boilers had small bags on the fire sheet : in one boiler
two braces were broken and they all needed scaling. I
recommended thai the plant be closed until repairs were
made, anil the superintendent nearly had a fit.
Another plant contained water-tube boilers that had
been giving trouble from pitting tubes. The engineer
claimed to have been an inspector and resented my making
an inspection, but as I was boiler foreman I made one
at the next washout. The tubes were clean owing to using
a cleaner. When the manhole was removed on the steam
drum, the steam line was found leaking so badly past the
valve that the line had to be cut and a blind gasket put
in to keep the steam out.
The drum was badly scaled, seven riser tubes were
plugged and the rest were dirty. The risers were cleaned
June 1, 1915
POW E R
75:
and a new set of tubes recommended, ;ils<> that all leaks
in the steam line and valves be repaired before the lioiler
was returned to service.
It is time that the United States Government controlled
the inspection of all boilers or enacted some law that
will make it a criminal offense to report a lioiler in good
condition unless it is so.
L. B. MOORELAND.
Denver, Colo.
(Clhsupggiin&gg § ma Si II II Sftos'Si^e
In charging a small storage battery the common meth-
"(I is to use a bank of lamps for regulating the current,
is shown in Fig. 1. By this means the current pass-
ing through the battery is roughly determined by the
n umber and size of lamps used. The simplest way to
determine the correct battery connection is to connect
the wires first one way, and then the other, and note
which way the lamps burn the dimmest ; the dimmest
is the correct way. Another simple method is to put
the ends of the wires into a cup of water containing a
little salt, acid or sal ammoniac; the wire around which
the most bubbles are seen is the negative and should be
connected to the negative side of the battery.
The foregoing method is very wasteful of electrical
energy. Suppose a three-cell battery is to be charged
from a 110-volt circuit; the battery will take only a
little over six volts and the difference must be taken up
by the lamps. Therefore, less than 7 per cent, of the
energy expended is actually used in charging the bat-
tery. '
To avoid this loss the writer devised the method shown
in Fig. 2, where L and L' represent the wires leading
Fig. 1. Usual Method of Charging Battery
from the exciter to the main field of an alternator and
8 is the usual double-pole switch on the exciter circuit
of the switchboard. One of these wires is disconnected
from the switch S and is connected to one side (2) of
a two-point switch, the common point (1) of which
is connected to switch 8 at P. From terminal 2 on the
two-point switch a wire leads to one side of the flat-
tery and the other side is connected to the remaining
point (3) of the switch through an ammeter. A rhe-
ostat is connected as shown so that the current flowing
through the battery can be regulated. The meter must
be connected so as to measure only the current flowing
through the battery.
When the two-point switch is connected from point
1 to point 2 the battery is out of circuit and should
have one of its wires disconnected to prevent it from
discharging through the rheostat. The battery should
never be connected in circuit when the exciter is not
running, for then it will either discharge through the
rheostat or through the exciter, depending ou which
way the two-point, switch is thrown.
s
T
V
Fig. 2. Charging Batter* i\ Sekiei
Field
with Generator
lb,
two-point switch is turned
To put the battery in circuit,
to it and then turn the switch
If the connections are right the
being excited will fall slightly
ittery is deducted from that of
mnections are wrong the voltage
When not charging,
tn connect from 1 to 2
first connect the wires
to connect from 1 to '■>.
voltage on the machini
as the voltage of the 1
the exciter, but if the <•
of the machine will be raised slightly, as the voltage of
the battery will be added to that of the exciter. This
is the only test for polarity required. The battery should
alwavs be disconnected before shutting down the machine
charging it, as otherwise its current will be discharged
through the exciter armature and the polarity of the
machine may be reversed.
"When charging batteries by this method the only en-
ergy wasted is the little taken by the rheostat. This
will depend on the current required for charging as
compared with that passing through the exciter circuit.
If the exciter circuit does not carry as much as is called
for to charge the battery, the latter will have to be
left in circuit longer; that is, it will have to be charged
at a lower rate.
(J. E. .Miles.
Denver, Colo.
EEecttrncsiMy C©ir&for'®M©dl IDsyinmpes'
]R@g|'aflEsift©ff!
In Mr. Carples' comments on my letter that appeared
uniler the above heading in Power, Apr. 13, page 517,
he says he believes it would be difficult to determine the
quantity of air required to burn a certain kind and
quality of coal per square foot of grate per hour. He
further says I do not explain how this is determined. It
is quite easy to determine, when one is getting the best
758
P 0 W E R
Vol. 41, No. 22
{ m . — ; 1 >le flue-gas analysis daily, and the coal runs uniform,
as it does.
Mr. Carples is quite right in his contention that the
quantity of air required changes with the quality and
kind of coal and must he redetermined when these factors
change. It is well known that the average C02 can he
kept at a higher percentage under close draft regulation
than when allowed a wide fluctuation, and that un-
der close regulation the efficiency of a boiler will be
high.
There is no balanced-draft system that I ever heard of
that operates without Mowers. What my letter makes
clear is that we accomplish results nearly equal to those
obtained by balanced-draft systems and without the use
of blowers or the cost of power to operate them. 1 hope
this is clear to Mr. Carples.
Henry W. Geabe.
Xew York City.
Stmppll^ ifos* Oal°<C^as]hflOKa
On large hoisting engines and others which are re-
versed frequently the links are shifted by an independent
steam-cylinder equipment. In order to avoid too quick
and destructive motion of the piston, another cylinder
filled with oil is fitted with a piston and D-valve and
connected, to oppose the steam piston's motion by acting
Cushioning Device for Reversing Engine
on a cushion of oil. The illustration shows the general
arranpement.
If the oil does not entirely fill the cylinder there is
sure to be a jerky motion at the beginning of the stroke
somewhat similar to that of a direct-acting pump which
is getting air with the water it is pumping. To make sure
that the cylinder was tilled at all times, I connected a
large oil cup J to the oil-cushion cylinder by means of
small pipe and check valves .4 and B. as shown. The
action is as follows: When the piston moves in the
direction of the arrow, check valve A opens, if there is
a partial vacuum created, and admits a little oil. At
the same time cheek B is dosed, so that there is no escape
of oil through it. In the other direction the action is
reversed, and the oil cylinder is kept full at all times.
G. D. Dearborn.
New York City
e Knag's
While making some changes on a direct-current switch-
board some time ago, we ran out of lugs, or terminals,
and as it would take two days to get them from the near-
est supply bouse, we decided to make them out of half-
inch brass pipe annealed by heating to a dull red and
ducking in water. We then sawed oil' several pieces
Terminal Lug Made of Pipe
about 2y2 in. long and drove a piece of %-in. round
iron in one end about 1 in. The other end was then
put in a big vise about l1/^ in. and flattened down. The
iron was then removed and the hole drilled in the flat
part, which was then finished up with a file. The lugs
proved to be just as strong as the cast ones and, being
of brass, were also good conductors. This saved us two
days' delay.
J. Gekber.
Dansville, X. Y.
I have been a reader of Power for a long time, but do
not remember reading any articles about the paper mills.
I am now in charge of a plant consisting of 3300 hp. in
steam and 1400 kw. generated by water power, furnishing
power for making sulphite fiber and paper. Perhaps I
am over-zealous in my line of business, but I should like
to hear from others working along the same lines, and
perhaps we might compare notes and help one another
Only one who has worked at it can know the varied ex-
periences encountered in the pulp- and paper-mill work
Steam is used for everything, from thawing frozen pulp
to blowing out screen plates, and when things are going
along fine, suddenly a 6-in. pipe line is opened into a
digester, or two or three steam jets into the beaters, which
will keep a man finessing how his coal report will look in
the morning.
Lefs make ourselves heard.
W. II. Holmes.
Lincoln. X. H.
I am sending a list of questions (from memory) which
were recently asked in an examination for the position of
third-class engineer, hoping they may help others.
1. What causes scale, and how is it prevented?
2. What is a water column, and is it always dependable?
3. What is a fusible plug, and what is it used for?
4. Describe a heating- system, and show how condensation
is returned to the boiler.
5. Name several causes for an engine pounding and the
remedy for each.
6. How is an engine governed? Describe a governor.
T. Describe a feed-water heater, and give two reasons why
water should be heated before entering a boiler.
8. What parts of an elevator should be inspected daily?
9. What care should be used in starting a new boiler?
10. (a) Sketch a round pipe strap. What is the vent for?
(b) How is a 4-in. soil pipe calked?
R iymond J. Carey.
Fitchburg, Mass.
June 1, 1915 POW E B 759
§l II B8W in liiilliilil nil .mum mil limn I mill I ilililiinii iiiinui m nun nun mum u uiiiiiiniii I mini i miiniinm iiiiiiiiihiiiiiiiiiiii iiimiiinn c
Iiniqpuiiiriies ©f General Inntterestt
1 in iiiiiiiiiiiiiiiini iiiiiini 111! ttiiniiinilli inn mail u inn I mum mini i mi niimimm uiiiyiiiimiiii miimmiiiiiiiimimiiiiiiiiiiiiiiii iiimi mi i minium g gggj
Short-Stroke of Pump — What will cause a duplex pump to
reverse before completing the stroke?
c. w. o.
The pump will short-stroke if the lost motion of the steam
valve is not enough to delay reversing of the steam valve
until the piston has completed its stroke.
Chnngrins; from Xoncondensingr to Condensing: — What dif-
ference should be made in the setting of the valves of a com-
pound engine to run condensing in place of noncondensing?
M. D.
For running condensing the principal change required in
the valve setting would be to secure earlier closing of the
exhaust valvts of the low-pressure cylinder, so as to obtain
the same cushioning effect from compression of exhaust steam
of lower pressure.
Flash and Burning Points of Oils — What is the difference
between the flash point and the burning point of an oil?
J. R.
The flash point is the lowest temperature at which the oil
discharges vapors that ignite with a flash when a lighted
taper or match Is passed at intervals of a few seconds over
the surface of the oil, while the burning point is the tem-
perature which the oil must attain for the vapors to burn
continuously over the whole surface.
Advantage of Narrower Belt — Where the narrower belt is
sufficient for transmission of the power, what saving of power
would be obtained by substituting a 3-in. single leather belt
in place of a 4-in. single leather belt for transmission of
power from an electric motor?
P. C.
For the same total belt tension there would be no saving
of power except that lost in bending the wider belt around
the pulleys. With belts in good condition, the power thus lost
is so small that the saving from use of the narrower belt
would be inappreciable.
Why Smaller Discharge Pipe Worked Better — For pump-
ing water over a hill a pump with a 4-in. discharge pipe would
not do the work, but upon replacing the pipe with one 2% in.
diameter, a satisfactory amount of water was delivered. Why
should delivery be better by use of the smaller discharge
pipe?
E. A. W.
It is probable that at a time when the larger pipe was in
use a greater rate of discharge was permitted from the lower
end than was being supplied by the pump, and that siphonage
caused the discharge line to become airbound at the crest of
the hill.
Kinking of Boiler Flue-— What would cause one flue of a
return-tubular boiler to become warped, or kinked out of line,
more than others in the same horizontal row?
F. K.
If the flue was under stresses of cold bends, such as it
might have received from rough handling or from straight-
ening the flue before it was set in the boiler, the stresses pres-
ent would draw it more out of line with each repeated heat-
ing and cooling and permanent distortions would be pro-
duced to a greater extent when the cooling was sudden,
as by admission of much cold air through the fire-door for the
purpose of checking a hot fire.
States Having Workmen's Compensation Acts — In what
states have workmen's compensation acts been passed?
S. K. C.
To this date Workmen's Compensation Acts have been
adopted by 30 states, as follows: Arizona, California, Colorado,
Connecticut, Illinois, Indiana, Iowa, Kansas, Louisiana, Maine,
Maryland, Massachusetts, Michigan, Minnesota, Montana, Ne-
braska, Nevada, New Hampshire, New Jersey, New York, Ohio,
Oklahoma, Oregon, Rhode Island, Texas, Vermont, Washing-
ton, West Virginia, Wisconsin and Wyoming. In addition to
•these an act was passed by the State of Kentucky, but was
declared unconstitutional.
standards of Hardness of Water — What is the basis upon
which the degree of hardness of water is designated?
J. B. R.
Hardness of water is usually designated according to one
of the following standards of hardness:
French — Milligrams of calcium carbonate in 100 grams of
water or parts per 100,000 of water.
Herman — Milligrams of lime in 100 grams of water, or parts
per 100,000 of water.
English — Grains of calcium carbonate per Imperial gallon of
70,000 grains.
American — Grains of calcium carbonate per U. S. gallon of
58,381 grains.
Power Required for Operation of Pump — For raising water
to an elevated tank, what horsepower will be required to
operate a 7xl0-in. pump making 95 strokes per minute with
a suction lift of 8 ft. and working against a pressure of 70 lb.
per sq.ln., allowing for 15-per cent, slippage and 22 per cent,
of the power lost in friction?
K. C.
With 15-per cent, slippage the effective length of stroke of
the pump would be 85 per cent, of 10 in., or 8.5 in. A suction
lift of S ft. would be equivalent to overcoming pressure of
the atmosphere of
8 X 0.434 = 3.47 lb. per sq.in.
which, together with the discharge pressure, would amount to
3.47 + 70 = 73.47 lb. per sq.in.
pressure overcome by the piston. The area of piston being
7 X 7 X 0.7854 = 38.4846 sq.in.
the work performed in lifting the water would be
38.4846 X 73.47
at the rate of
•
12
■X 95 = 190,264.73 ft. -lb. per min.
190,264.73 -f- 33,000 = 5.76 hp.
With 22 per cent, of the applied power lost in friction, the
power required for operation of the pump would be
5.76
= 7.38 hp.
1.00-
■0.22
Torsional Deflection of Iron Shaft — What would be the
torsional deflection of a vertical iron shaft 10 in. diameter
and 150 ft. long, running 200 r.p.m. and transmitting 1350 hp.?
G. H. R.
The angle of torsion is given in degrees by the formula,
583.6 Pal
d' G
which
1 = Length of shaft (inches),
d = Diameter (inches),
P = Force (pounds) applied at the extremity of a lever
arm = a in inches,
Pa = Twisting moment,
G = Modulus of torsional elasticity, which for an iron
shaft would be equal to about 10,000,000.
Transmitting 1350 hp. at 200 r.p.m., the foot-pounds would
1350 X 33,000
0 ft. -lb. per revolution,
ould be
and the twisting moment, I'a, in inch-pound
222,750 X 12
= 425,420
2tt
As 1, the length of shaft, is 150 ft. = 1800 in., and d, the
diameter, = 10 in. ,then by substitution the formula becomes,
583.6 X 425,420 X 1800
A — = 4.47 deg.
10' X 10,000,000
which on the circumference of a 10-in. diameter shaft would
measuri
10 X 3.1416 3 1
0.39 in., or about - +
360
64
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
760
I'm w i: 1:
Vol. 41, X.i. 22
Co im^e Eafta ©ia
Members of the National Association of Stationary Engi-
neers in Missouri held their annual state convention May
19-21 at the Planters Hotel in St. Louis. With the 40 delegates
and a number of visiting engineers from the vicinity, the at-
tendance was up to normal. At the opening session, Wednes-
day morning. Associate City Counselor Charles H. Davies.
in behalf of Mayor Kiel, welcomed the delegates to the city.
In the response Fred W. Raven, national secretary, sum-
marized briefly the aims and policies of the organization and
the benefits to be derived from the practical education avail-
able to the members. Referring to Missouri's well-known
motto, he suggested that the "me" be changed to "them." In
other words, the members should show others the benefits to
be derived from, and get them into, the organization. First
of all, more interest must be taken in the work. Missouri
has been drifting, and if she is to keep pace with her pro-
gressive neighbor, Kansas, there is urgent need of good work
in the state. More enthusiasm, individual effort and the elec-
tion of active officials were the things most needed.
J. H. Van Arsdale, past-national vice-president, reminded
the engineers that they were assembled for the purpose of
collectively seeing what could be done for the benefit of the
organization. It stood for education, and many benefits could
be derived from membership if advantage were only taken of
opportunities available. Although national officers were doing
all they could to improve the official paper there was need of
the assistance of the engineer. The latter was not doing jus-
tice to the paper when he failed to credit its advertising pages
as the source of inquiries for power-plant products. State
President Daggett responded, urging a full attendance in the
exhibit hall. The convention was then formally opened and
the usual committees appointed.
Bennett-Dreyer-Buss Belting
Co.
Big Muddv Coal & Iron Co.
C. J. & F. E. Briner.
Broderick-Bascom Rope Co.
Busch-Sulzer Bros. -Diesel
Engine Co.
Clement-Restein Co.
Commercial Electrical Supply
Co.
Crandall Packing Co.
Crane Co.
Dearborn Chemical Co.
Donk Bros. Coal & Coke Co
The Edward Valve & Mfg. Co.
Walter L. Flower Co.
The Garlock Packing Co.
A: Co.
Hawkeve Compound Co.
Heine Safety Boiler Co.
Price Hill.
Home Rubber Co.
H. W. Johns-Manville Co.
Kayser Tanning Co
Keystone Lubricating Co.
Kupferle Bros. Mfg. Co.
Modern Engineering Co.
Morse Engineering Co.
Mound City Oil & Supply Co.
Mount Olive & Staunton Coal
Co.
"National Engineer"
New York Belting & Packing
Co.
Otis Elevator Co.
The P.-K. Engineers.
The Peerless Rubber Co.
Pierce Oil Corporation.
The William Powell Co.
"Power."
Reeves & Skinner Machinerv
Co.
Ridgway Dynamo <t Engine
Co.
St. Louis Pneumatic Tool &
Supply Co.
F. C. Schwaner & Co.
Spencer Turbine Cleaner Co.
Standard Oil Co.
Western Boiler Compound &
Chemical Co.
Western Valve Co.
/aceEasaE&g
IFassedl
Governor Walsh of Massachusetts signed an act on May 17
(Chapter 259) relative to the licensing of engineers and fire-
men, following extended discussion of this subject by the
present Legislature. The act retains the supervision exer-
cised by the boiler-inspection department of the district
police over steam boilers and engines, licenses, examinations,
etc. Its definitions of classes of licenses are of chief interest.
The act provides a nine-horsepower limitation on the size
of boilers and engines that may be operated without a license.
with the well-known exception of boilers and engines of loco-
motives, motor vehicles, residences and agricultural power
Missouri X. A. S. E. Delegates Assembled at St. Louis
Routine business occupied the afternoon session. In the
evening a get-together banquet proved a great success.
Afterward, the diners retired to the exhibit hall and joined in
favorite selections from the official songbook.
Much of the Thursday morning session was taken up by a
discussion on the needs of the state organization. The ad-
visability of discontinuing the convention, holding it at less
frequent intervals or perhaps combining with Kansas, was
considered. That general opinion favored continuance along
the usual lines was evidenced on Friday when Kansas City
was chosen as the convention city for 1916.
Thursday afternoon was featured by an inspection trip
through the Anheuser-Busch Brewery and the manufacturing
plant of the Busch-Sulzer Bros. Diesel Engine Co. In the
evening an illustrated lecture by E. A. Garrett on the product
of the latter company drew a large attendance.
On Friday morning news of the death of C. H. Huntington,
president of St. Louis No. 2. was received with many mani-
festations of sorrow. The convention drew up suitable reso-
lutions and authorized a presentation of flowers. Only nec-
essary business was completed and all entertainment features
on the program, such as a vaudeville entertainment listed for
that evening, were eliminated. The following officers were
elected and installed: L. Kjerluff, president; Charles Parkin-
son, vice-president; Rice Nance, secretary: F H. Munsberg,
treasurer; F. Middleton, conductor; Jacob Newpert, door-
keeper; Fred Key, trustee; S. J. Hunt, deputy, and L. Kjerluff,
assistant deputy.
The companies represented in the unusually good exhibi-
tion and those who contributed follow:
The V. D. Anderson Co.
Arrow Boiler Compound Co.
Baumes-McDevitt Machinery
A. Leschen & Sons Rope Co.
The Lunkenheimer Co.
James P. Marsh & Co.
George F. Matthews & Co.
units. Under its terms, to be eligible for examination for a
first-class fireman's license, a person must have been employed
as a steam engineer or fireman in charge of operating boilers
for at least a year, or must have held and used a second-class
fireman's license for not less than six months. To be eligible
for examination for a third-class engineer's license, a person
must have been employed as a steam engineer or fireman in
charge of operating boilers for not less than one and one-half
years, or must have held and used a first-class fireman's
license for at least one year.
To be eligible for examination for a second-class engineer's
license a person must have been employed as a steam engineer
in charge of a plant having at least one engine of over 150
hp. for not less than two years, or he must have held and
used a third-class engineer's license either as an engineer,
assistant engineer or fireman for not less than one year, or
have held and used a special license to operate a first-class
plant for not less than two years: except that any person
who has served three years as apprentice to the machinist or
boiler-making trade in stationary, marine or locomotive
engine or boiler works and who has been employed for one
year in connection with the operation of a steam plant, or any
person graduated as a mechanical engineer from a duly recog-
nized school of technology, who has been employed for one
year in connection with the operation of a steam plant, shall
be eligible for examination for a second-class engineer's
license. A person must have been employed for not less than
three years as a steam engineer in charge of a plant having
at least one engine of over 150 hp., or he must have held and
used a second-class engineer's license in a second-class or
first-class plant for not less than one and one-half years.
Licenses shall be distributed as follows:
Engineer's licenses: First-class, to have charge of and
operate any steam plant: second-class, to have charge of and
June 1. 1915
P < > AY E P
761
operate boilers or engines, no one of which shall exceed 150
hp., or to operate a first-class plant under the engineer in
direct charge; third-class, to have charge of and operate boil-
ers not exceeding 150 hp. in the aggregate, or engines not
exceeding 50 hp. each, or to operate a second-class plant under
the engineer in direct charge; fourth-class, to have charge of
and operate hoisting and portable engines and boilers; port-
able class, to have charge of and to operate boilers and port-
able engines except hoisting and steam fire engines; steam
fire engineer's class, to have charge of and to operate steam
fire engines and boilers.
Firemen's licenses: Extra first-class, to have charge of and
operate any boiler plant; first-class, to have charge of and
to operate any boiler where the safety valve is set to blow at
a pressure not exceeding 25 lb. per sq.in., or to operate high-
pressure boilers under the engineer or fireman in direct charge
thereof; second-class, to operate any boiler under the engineer
or fireman in direct charge thereof. A person holding an
extra first-class or first-class fireman's license may operate
a third-class plant under the engineer in direct charge of it.
Special license: A person who desires to have charge of
and operate a particular steam plant may be examined for
such a license, but no engine of over 150 hp. is to be operated
by such a person except where the main power plant is run
by water power exclusively during the major part of the
time and has auxiliary steam power for use during periods of
low water.
Mo A, §= I£o C©mw©E&ftfi©ia
The annual convention of the Pennsylvania N. A. S. E.
will meet at Pittsburgh, June 18 and 19. Headquarters
will be at the Monongahela House, where all sessions are to be
held. State President J. D. Rostron, of Chester, Penn., will
preside. The other state officers are: P. O. Johnson,
M©w Jolhiras
IrH© -jp Manas IB^iallcdlaini^s
edll<csift©<dl
After the general exercises dedicating the new engineering
building and power plant of the Johns Hopkins University, at
Homewood, Baltimore, Md., an inspection tour through the
engineering laboratories and power station was arranged for
the evening of May 81. A short talk was given by the heads
of the various departments, explaining the main features of
the work under their charge, closing with a few general
remarks by the newly installed president, Frank Johnson
Goodnow, lately constitutional advisor to the Chinese Gov-
ernment. Instruction in mechanical engineering is in charge
of Prof. Carl Clapp Thomas, M. E. ; that in civil engineering
is directed by Prof. Charles Joseph Tilden, S. B., and in charge
of the department of electrical engineering is Prof. John
Boswell Whitehead, Ph.D.
The power-station equipment is used as far as possible
for both instructive experiments and supplying heat and elec-
tric'current for the buildings. The steam and electric distrib-
uting systems are in light, roomy tunnels, which also afford
convenient passageways from building to building.
In the power station are four B. & W. type water-tube
boilers, each having 2640 sq.ft. of heating surface and carry-
ing 125 lb. pressure. They are equipped with automatic feed-
water control, high- and low-water alarm, and in the brick
setting there are openings for thermometers, draft gages, CO*
recorders. Under two boilers there are underfeed (Taylor)
stokers and under the other two overfeed (Roney) stokers.
The air supply from the fan to the stokers is measured by a
Thomas recording gas meter, designed by Professor Thomas,
and an accurate record may be made of the air supply to-
Check with the flue-gas analysis.
The brick chimney, 160 ft. high and 7 ft. in diameter, has
openings at various points (and convenient staging or bal-
Jas. D. Rostron, State President (center)
Pennsylvania N". A. S. E. Officials
P. O. Johnson, State Vice-President (left) ; and R. B. Ar
e, State Secretary (right)
Philadelphia, vice-president; R. B. Ambrose, Pittsburgh,
secretary, and D. E. Seeley, Dubois, treasurer. The com-
mittee in charge of the local arrangements for the con-
vention is made up from the membership of the three Pitts-
burgh associations. This committee, of which George A. Bu
Miller is chairman and L. S. Evans (care Lawrence Paint Co.,
Pittsburgh) is secretary, is preparing an elaborate entertain-
ment and inspection program.
few Jersey H, A.
The state convention of the New Jersey National Associa-
tion of Stationary Engineers will be held in Masonic Hall,
Warren and State St., Trenton, June 3 to 6, inclusive. Dele-
gates' headquarters will be at the Trenton House, opposite the
exhibit hall. A large attendance is expected on account of
Trenton being a central location.
J. F. Lightford, president of Trenton No. 4, N. A. S. E., is
•chairman of the executive committee; William Hirst, vice-
chairman; William W. Law, treasurer; E. A. Corbett, secretary.
conies) from which gas samples may be obtained, and also
the temperature and velocity determined.
By using Orsat flue-gas apparatus, of which there are two
side by side, one a German type and the other American, the
composition of the flue gas may be determined and the degree
of efficiency of the furnace operation indicated. A Pintsch
CO? recorder, which is a new and interesting development,
takes samples of gas from the breeching just below the
damper. It passes through a dry excelsior purifier, then
enters a cooling coil that is jacketed by the water used to
operate the ejector. This brings the gas to a constant tem-
perature. It next passes through a small precision gas meter
containing light mineral oil and then through an absorber,
where the C02 is removed. The absorbing agent is slaked
lime mixed with sawdust to keep it porous. This can be
readily renewed once a week at very small cost. After leav-
ing the absorber the gas passes through another cooling coil
to remove the heat generated by the absorption of the CO? and
is then directed through a second precision gas meter. The
siphon ejector is placed after the second meter. The first
meter measures all the gas; the second measures a lesser
quantity by the amount of CQ2 absorbed, and therefore runs
762
POWEK
Vol. 41, No. 22
slower. A differential gear and mechanism transmutes this
speed difference into vertical pen motion and makes a record
on the chart. The pen is released and makes a dot on the
chart for every cubic foot passing, its relative position indi-
cating the percentage of C02. The coal- and ash-handling
systems are so arranged that during tests accurate weights
may be taken.
From the boilers the steam may be led through an inde-
pendently fired superheater to the engines or by a direct line
in a saturated state, so as to demonstrate the effect of super-
heat on the efficiency and steam consumption in the engines
under various conditions of operation.
In the main engine room there are three units: A Harris-
burg four-valve reciprocating engine rated at 150 hp. at 200
r.p.m., directly connected to a Westinghouse 100-kw., 250-volt
generator. A Kerr (Economy) turbine, connected to an
Allis-Chalmers 100-kw. generator; and a Westinghouse tur-
bine set. All of these are so piped that the exhaust steam
may be used for heating the buildings or may be directed to
a Wheeler surface condenser having 300 sq.ft. of cooling
surface capable of condensing 2500 lb. of steam per hour with
cooling water at 70 deg. The condensation may be led to the
weir tanks and measured. The cooling water also is meas-
ured by a venturi meter.
In another part of the building a Nash producer-gas engine
rated at 14 hp. is supplied by a Smith suction gas producer
using anthracite coal, which gives the student an idea of the
general requirements of such apparatus.
A Diesel-type crude-oil engine loaned by the Allis-Chal-
mers Manufacturing Co. is used for experimental purposes.
It is equipped with special attachments for testing and is
capable of using almost any kind of clean liquid fuel.
On the floor above, a Buckeyemobile engine, directly con-
nected to a 75-kw. generator, represents the latest develop-
ment in a self-contained steam unit of remarkable efficiency.
Various other equipment connected with the heating and ven-
tilating operation, and meters, oil testers, calorimeters, etc.,
give the student a comprehensive insight into actual power-
plant management and, together with extensive laboratory
equipment, make it possible for the instructor to demonstrate
the latest practice in engineering.
Walter R. Johnson is no longer associated with the Har-
rison (Cochrane) Safety Boiler Works. He was formerly
Southern representative, with headquarters at Atlanta, Ga.
H. D. McCaskey has been designated as statistician in
charge of the Division of Mineral Resources, U. S. Geological
Survey, succeeding Edward W. Parker, resigned, as noted
elsewhere. Mr. McCaskey was a mining engineer in the
Philippine Mining Bureau from 1900 to 1906, and has been with
the Geological Survey since 1907. He will also continue his
work upon the metallic resources of the United States.
Edward W. Parker, statistician in charge of the Division
of Mineral Resources, U. S. Geological Survey, and for many
years the Government coal statistician, leaves the Govern-
ment service July 1 to accept a responsible position with the
anthracite mining interests. Director George Otis Smith, of
the Survey, has gone on record as expressing his regret at this
termination of Mr. Parker's long and efficient service, which,
in addition to the work mentioned, has comprised a study of
coal testing and conservation and the publication in the en-
gineering press of many papers on coal mining and production.
The Worcester Polytechnic Institute will celebrate its
fiftieth anniversary June 6-10. The dedication of a new
gymnasium, a special meeting of the American Society of
Mechanical Engineers to be held at the works of the Norton
Co., and the annual commencement exercises are among the
events scheduled. President Wilson, who was the commence-
ment orator twenty-five years ago, has expressed a desire to
be present, and it is hoped that the pressure of public busi-
ness may permit his attendance. Gen. George W. Goethals
has already accepted an invitation to be present.
ATLANTIC COAST STATES
Bids will be received until June 1 by the Children's
Institution Department, Boston, Mass., for a 15-kw. direct-
connected engine and generator at Rainsford Island. John
O'Hare is Comr.
The town of Milford, Mass., is considering the purchase
of the plant of the Milford Electric Light & Power Co. Wil-
liam Plattner, Attleboro, has been retained to appraise the
value.
At a recent town meeting in Sterling, Mass., an appropria-
tion of $5900 was made for extending the transmission lines
of the municipal electric-lighting system as follows: Camp
grounds at Sterling Junction. $2600; Rowley Hill district,
$2(100. and to the Chocksett district, $1300. H. W. Rugg is
Mgr. and Supt. of the municipal plant.
Bids will be received until June 1 by C. B. J. Snyder, Supt.
of School Buildings, Park Ave. and 59th St., New York, N. T.,
for additions, alterations and repairs to the electrical equip-
ment in Public Schools 25, 31, 44, 62, 177 and 188, Borough
of Manhattan.
It is reported that the Crucible Steel Co. of America,
Harrison, N. J., will build a new power station on Cumberland
St. in connection with the extensions to its plant.
The Atlas Finishing Co., Homestead, N. J. (West Hoboken
post office), plans to build a one-story power house.
The Toms River & Island Heights Electric Light & Power
Co., Toms River, N. J., will soon install one 125-hp. Coates-
ville boiler in its plant. C. A. Brant is Secy, and Mgr.
The Borough Council of St. Clair, Penn., is considering
plans for improving the municipal electric-light plant. J. J.
Hughes is Mgr. of the plant.
The City Council of Cumberland, Md., is reported to be
considering improvements to the municipal electric-lighting
system at an estimated cost of $15,000. A high-speed steam
turbine, directly connected, will be installed, and the present
street-lamps will be replaced by new ones. James P. Gaffnev
is City Engr.
SOITHEHN STATES
According to press reports, the North Carolina Electrical
Power Co., Asheville, N. C, plans to build a steam-driven
auxiliary electric plant on the French Broad River to cost
about $150,000. Generating equipment for 4000 hp. will be
installed this year. W. T. Weaver, Asheville, is Pres. and
Mgr.
At a recent election the citizens of Waynesville, N. C,
voted in favor of issuing $25,000 in bonds to be used for
the installation of a municipal electric-light plant.
Bonds in the sum of $10,000 have been voted by the
citizens of Gleason, Tenn., for the construction of a municipal
electric-light plant.
The Lancaster Electric Light Plant, Lancaster, Ky., will
increase the equipment of its plant to provide 24-hr. service
for the town. Alex Walker is interested.
CENTRAL STATES
Press reports state that the City Council of Oberlin, Ohio,
is considering the installation of a municipal electric-light
plant and water-works system.
It is reported that the new Alhambra Theater, Sandusky,
Ohio, will be equipped with an independent electric-light and
power plant. The equipment will include a 90-hp. Bruce-
McBeth engine and a 50-kw. generator, directly connected.
It is reported that the Western Drop Forge Co., Marion,
Ind., will increase its power plant by the addition of 700 hp.
WEST OF THE MISSISSIPPI
Bids will be received until June 7 by the Town of Alta
Vista. Iowa, for the construction of an electric transmission
line and a distribution system for the town. F. Rabe is
Town Clk.
The town of Charter Oak. Iowa, has sold bonds, the pro-
ceeds of which will be used for the installation of a municipal
electric-light plant.
A special election will be held in Lake City, Iowa, to vote
on the question of granting a 25-year franchise to the Central
Iowa Light & Power Co., Boone, to furnish electricity for
lamps and motors in Lake City.
The City Council of Wilton Junction, Iowa, has rejected
the offer made by the Davenport & Muscatine Ry. Co., Daven-
port, to build a transmission line to Wilton Junction, and
will rebuild the municipal electric plant. George Bannock
is Mayor.
Preliminary plans are being prepared for the installation
of a municipal electric-lighting system for the town of
Muscotah, Kan.
It is reported that the Texas Southern Electric Co., Vic-
toria, Tex., has purchased the electric-light and ice factory
of the City Ice & Electric Co., Del Rio, Tex. The reported
purchase price is $90,000. The new owners will improve the
property.
Bids will be received until June 3 by Wilson & Cutting,
Engrs., 325 Electric Bldg., Butte, Mont., for the installation of
an electric-heating system (indirect with fan) in the High
School at Burley, Idaho. The»building contains 40 rooms.
The plant of the Morton Electric Co.. Morton, Wash.,
owned by F. M. Broadbent, has been sold to C. O. Smith of
Pe Ell, AVash., at approximately $20,000. The plant will be
enlarged and improved at once.
It is reported that the West Virginia Mining Co., operating
the Lone Surprise mine at Republic, Wash., will install a
200-hp. compressor, a new Diesel engine and an electric hoist.
POWER
Vol. 11
NEW YORK, JUNE 8, 1915
No. 23
The Power of
Ambition
Do you want to be more suc-
cessful, earn more money,
occupy a better position in
life? You can do it. Your
life is in your making.- Be
you what you may, you can
rise to a height limited only
by your ambition and your
energy.
You say you are now putting
in the better part of the day
in a hot and stuffy power
plant. That should not deter
you. You are AMBITIOUS.
Can't you feel an invisible
something forcing you up-
ward, almost against your
conscious will, continually
urging you onward and on-
ward? You know that to
attain a higher position, you
will have to make yourself
more valuable to your em-
ployer and to the world. One
way to do this is to study good
books; subscribe to the best
technical magazines; so that
you may keep informed of
the latest progress in your
business.
Your limit is not the Chief
Engineer's desk. It is but a step from that to an
executive position. Once you start working in earn-
est, you will be surprised at THE POWER OF
AMBITION.
iiiiiiniiiii:i:i! Niaiiiiiiiiiiiiiiiiii
CMsift
what you
may, you can
rise to a height
limited only by
your ambition
and energy.
greater effort; if adverse, it
will only make you clench
your teeth and fight the
harder. But first you must
fix in your mind what object
you are going to attain;
choose a definite goal, so that
you can concentrate all your
efforts toward it.
In this fight for advancement,
it is very much as in actual
warfare — ■ once the general
discovers where the enemy
lies hidden, he can muster all
his forces to overcome them,
without having to spread
them over a large area with
the consequent weakening of
his power.
Be sure to set your mark high
enough. "Hitch your wagon
to a star." And above all,
don't allow yourself to be-
come discouraged at the first
obstacle you meet.
rj Any weakling can he down
and quit, but it takes a
MAN to be up and at it when
he encounters an obstruc-
tion in his path to success.
Just as the athlete becomes stronger by continued
physical exertion, so you will become stronger in
character by overcoming the obstacles confront-
ing you.
Every circumstance will be a spur and an incentive to Now then, FIRE UP! See what you can do!
!HI ;
(Contributed by Herman Block, Brooklyn, N. Y.)
;g4
P 0 \\ E li
Vol. -11, No. 23
'©wer Flaunt ©f New7 IL^uiinmlber
By Thomas Wilson
SYNOPSIS— A direct-current plant with 600-kw.
generating capacity and 800 hp. in Scutch marine
boilers. Engines equipped with popp< I valves oper-
ated by eccentrics on a layshaft. Smalt steam pip-
ing and large receiver separators a feature. An ex-
cellent switchboard on which vertical circuit-break-
ers replace the usual switches and fuses on feeder
panels. Gravity ventilation for engine and bo
rooms.
On May 2, 191 !. the work of tearing down the old
Roanoke Building at the comer of Madison and La Salle
St.. Chicago, was started, and at the present writing the
Lumber Exchange Building, which has taken its place,
is practically complete.- The latter structure is a 16-story
To supply this building with heat, light, and power for
the electric elevators is the purpose of the power plant
located in the sub-basements. This plant contains a num-
ber of interesting features such as are indicated in the
synopsis. Generally speaking, it is substantial and upto-
date in every respect. For the services for which it is
intended the plant has been laid out to operate at high
economy, and a special effort has been made to hold the
labor and maintenance items to a minimum.
It has been estimated that the load will run close to
300 kw. during the heating season and up to 200 kw. in
the summer months. Consequently, units of these capaci-
ties and four boilers rated at 200 hp. each were installed.
At any one time two of these boilers will easily supply
sufficient steam for the generating units and there will
lie two in reserve. Exhaust steam will be used for heating,
Fig. 1. Engine Boom of Lumbeb Exchange Building
office building. 217 ft. tall from sidewalk to cornice.
erected by the L. J. McCormick estate. The steelwork
was designed for 20 stories, and the supporting risers have
been carried through the roof, so that if desired an exten-
sion may be easily made at any time. Below the sidewalk
there is a basement and two sub-basements containing the
engine and boiler rooms, the floor of the latter being 45
ft. below the street level. The two levels for the power
plant were necessary, as the adjacent building rests on a
floating foundation, within 30 ft. of which deep excava-
tion was not permitted. The frontage on La Salle St.
is 135 ft. and on Madison St. 101 ft. At the inner corner
a 17x75-ft. light-shaft above the third floor reduces the
outline to an L shape. The building is of substantial con-
struction throughout and, with its artistic terra cotta ex-
terior, presents a handsome appearance.
and to furnish a sufficient supply during nights and holi-
days a specially designed 100-kw. turbo-generator with a
high water rate will carry the load.
Boilf.k Installation
After due consideration of the magnitude and variable
character of the load, it was decided to install units of
200-hp. capacity. These boilers are of the Scotch marine
dry-hack type, 96 in. in diameter and 16 ft. long. By
means of a sheet-iron thimble lined with firebrick each
boiler is connected with a dutch-oven furnace equipped
with a top-feed stoker. Eventually, the air supply for the
furnace will be drawn around this thimble and introduced
into a closed ashpit. The stoker is provided with crush-
ing rolls at the bottom of the magazines, which not only
crush the coal, but also force it onto the grates. The latter
June 8, 191o
P O W E n
765
are V-shaped and are inclined atari angle of 15 deg. The
actual grate surface is 53 sq.ft. and 50 per cent, of this is
air space. To the L595 sq.ft. of heating surface in the
boiler, the grate area hears a ratio of 30.1 to 1. This is
considerably lower than commonly allowed, hut the boilers
are rated on 8 sq.ft. of surface per horsepower and the
large air space in the grate permits a high rate of com-
bustion.
The boilers arc desig 1 Eor '->(h) lb. pressure, but arc
operated at L60 lb. gage. They are covered with magnesia
block, and with a handhole <>n each side and one on the
top of the boiler, are easily accessible so that cleaning
may be effected in a comparatively short time. There is
diameter, but a t-in. lining all the way up reduce? the
bore to 5 ft. I in. A powerful draft is thus available, and
the proper intensity over the lire is obtained by damper
control. Differential draft gages with four connections —
one to the ashpit, one over the (ire, one at the rear of the
boiler and one to the uptake — make it possible to read the
draft at the particular points just mentioned or the drop
in draft through the furnace ami boiler. The smoke flue,
which is immediately in front of the boiler and runs over
the nar ends of the furnaces, is of tapering section. It
lias one right-angled turn ami at the stack its area is 27
sq.ft. This may be compared to 22 sq.ft., the free area of
the stack, and to a connected grate surface of 212 sq.ft.
Fig. 2. Boiler Installation with One of Tunnel Cars at the Eight
little loss from radiation. The boilers will hold their
heat well over night and by the omission of the usual
brick setting air infiltration is obviated. High economy
should be obtained, and with a furnace which can be hand-
fired if necessary, reliable and continuous service may be
expected. It is planned to run two boilers during the day
and bank one at night. By forcing, one boiler might
handle the load, but two are carried on the line to guard
against a possible interruption of the service. A point
worthy of consideration is that all repair parts that these
boilers may need can be conveyed to the boiler room
through the elevator shaft-
Natural draft is supplied by a steel stack rising about
300 ft. above the boiler-room floor. The shell is <i ft. in
To the last figure the breeching area bears a ratio of 1 to
8, but as it is not expected that more than two boilers will
lie operated at any one time, the ratio actually becomes
1 to -1, which is close to standard practice.
Feed water may be drawn from the heater or the city
mains and is forced to I be boilers by either one of two
simplex pumps. To guard against interruption of the
feed, the supply lines to the boilers are in duplicate and
are cross-connected so that parts of either line may be
cut out of service if desired. Provision has also been
made for weighing tank- to I"' n>n] in testing the boilers
or as a check on the V-notch meter.
Illinois screenings is used as fuel. It may he delivered
by wagon or through Chicago's underground freight tun-
?66
P O \Y E R
Vol. 41, No. 25
nel. Tlicre are four chutes from La Salle St.. each dis-
charging to a 50-ton reinforced-concrete hunker, one for
each boiler. When the coal is delivered through the tun-
nel, the cars arc run in on the boiler-room floor and
dumped into a hopper beside the track. From this hopper
a screw conveyor forces the coal to a bucket elevator,
which at the top of the boiler room turns at right angles
and delivers the coal to any one of the four bunkers. In
the horizontal run the buckets scrape the coal along a
-sr.-v vii -j=U
ff ?j D ET
FIRST FLOOR fl , Q ^ H
'.-PiT FOR COAL fiOIST
J SECTION A-A
A = IB heating Nam
B " f4*Atmospher/c Exhaust
C= Expansion Tank
Pig. 3.
Plan of Engine Room and Elevatiok
thbotjgh Plant
trough and through gates in the bottom of this trough,
which are operated by handwheels in the engine room,
and discharge it to any one of the bunkers. A track scale
weighs the coal on its way to the magazines of the stoker.
Ashes are shoveled directly into the tunnel cars, which at
stated intervals are removed from the plant.
To prevent spoiling the fires in the boiler furnaces, a
rubbish burner has been provided. This is a hot-water
boiler with a coal grate below and a tube grate above for
the paper and other waste from the building. Water for
house service passes through this boiler and absorbs the
heat from the waste material. Additional heat is supplied
by closed heaters in the engine room, provided with ex-
haust-steam connections and temperature regulators.
From the third floor down all sewage must be raised to
the street. For this purpose a duplex motor-driven sewage
ejector has been provided in the boiler room. To care
for an excessive quantity of water, a turbine-driven cen-
trifugal pump with a 10-in. suction and 5-in. discharge,
has been installed. The sewage must be elevated about
40 ft.
In the selection of the generating units, economy and
regulation were the first considerations. With an electric-
elevator load the variations are excessive and close regula-
tion is necessary to prevent the fluctuations showing in
the lights. Poppet four-valve engines were chosen as the
prime movers fur the two larger units. The valves are of
the balanced type and are positively operated by cams
oscillated by eccentrics on a layshaft. Between the two
eccentrics an inertia governor mounted on the layshaft
controls the speed. On its way to the inlet valves the
steam passes over the ends of the cylinder, tending to
reduce initial condensation and increase the economy of
the engine.
For these units, which are of 300- and 200-kw. capacity
respectively, the guaranteed steam consumption at full
load is 20.8 lb. per i.hp.-hr., but from results obtained
from engines of the same type a lower rate is expected.
The generators are two-wire, 2-tO-volt machines specially
provided with extra large air gaps and heavy series wind-
ings to care for the heavy inrushes of current caused by
the electric-elevator load. Compensators provide for
three-wire distribution on the lighting. The engines are
equipped with an automatic oiling system with an over-
head tank and drainage from the bearings to a filter in
the boiler room. Cylinder lubrication is effected by three-
feed pumps driven from the layshaft. One feed goes to
the throttle and one to each end of the cylinder. A reduc-
ing motion attached to a standard on the guide barrel and
driven by the crosshead is a permanent fixture of the
engine.
During the summer months it is the intention to run
the smaller engine unit. In the heating season the large
A- 4' ,Blo*t>f
■f Pomp
C - Elerator i
'-■■-■ r :-;---'
L= Boiler Feed Pumps '
Fig. 1.
Plan or Boiler Room below the Engine
Room
unit will carry the load. From preliminary estimates
it was figured that during the day there would be suffi-
cient exhaust steam for heating, as in addition to the en-
gines there are a number" of steam-driven pumps. At
night, howrever, and on holidays the load will be light,
and rather than supply the live steam which would be
necessary for heating through a reducing valve, it was
deemed advisable to utilize a turbo-generator with a water
rate purposely made high by the addition of nozzles so
June 8, 1915
POWEH
767
that sufficient exhaust steam would be available for heat-
ing. In other words, the turbine will act as a reducing
valve and at the same time generate all of the current that
is needed.
The unit consists of a 150-hp. single-stage turbine
directly driving a 100-kw., -.'ID-volt, direct-current gen-
erator at a speed of 2200 r.p.m. It was built especially
to meet the requirements of the particular class of service
existing in this plant. The governing device is so de-
signed as to give practically constant b] 1 under all con-
ditions of load. At this writing the turbine has not been
machine which may be installed at some time in the
future. All condensation from the loop and the auxiliary
header returns directly to the main header in the boiler
loom, and from here it is trapped to the heater.
The remarkable feature about the piping is the small
[.■ads supplying the generating units. A 3-in. pipe sup-
plies the 300-kw. machine, and the lead to the smaller
e i- ..ii!;. '.'I1. in. in diameter. A 25-per cent, over-
load on the engines will require a steam velocity of about
8000 ft. per min. in these pipes. As standards go, this
velocity might he considered excessive, hut as the pipes are
installed. A fuller description of this unit will he given
when the results of the acceptance tests are available.
Piping Akka no km ent
From the accompanying line drawings the piping ar-
rangement will he evident. Six-inch boiler leads connect
with a 12-in. header at the rear of the boilers. Risers lead
up to a 5-in. loop in the engine room and to an auxiliary
header supplying the boiler-feed, fire, house and vacuum
pumps. From this header there are also reducing-valve
connections to the expansion tank, so that live steam may-
be supplied to the heating system when the turbine
unit is not operating. If a large amount of live steam is
required, the 5-in. reducing valve will be used. For a
small quantity to supplement the exhaust-steam supply,
a 1%-in. reducing valve has been provided. This relieves
the larger valve and prevents the wire-drawing that would
occur with a small quantity of steam passing through.
The 5-in. loop now supplies the smaller engine and the
turbine and is also intended for a 150-ton refrigerating
used in conjunction with receiver separators four times
the volumes of the cylinders and large throttle valves, not
the slightest trouble has resulted during the short time
the plant has been in operation. The loop from which the
small engine draws its supply is suspended from rings in
the ceiling by means of turnbuckle hangers. It is not even
anchored, and yet there is no evidence of vibration due to
the cutoff of the engine. The reasons for this small pip-
incr are, of course, less radiation, less condensation and a
lower initial cost for piping and fittings. As the engine
throttles are 8 and 1 in. respectively, the supply of steam
is not curtailed, and any inequalities in pressure which
might result with the usual installation are smoothed out
by the large separators.
Through a tunnel under the engine-room floor the ex-
haust piping passes out into the boiler room, thence up
to the heater, which is on the engine-room floor, and on
to the expansion tank and the hot-water heaters for house
service. The relief valve to atmosphere is set for a back
pressure of 2 lb.
768
POW E K
Vol. 41, No. 33
A feature of interest is the separation of the V-noteh
meter and the feed-water heater. The connections are so
arranged that either may be cut out of service without
affecting the other or both may operate independently;
that is. the meter may measure the water to one boiler
which is perhaps running on test, while the water for the
other boilers is drawn directly from the heater. Piping
connections have also been made so that the returns from
the heating system or from any or all traps can be meas-
ured separately. Ordinarily, of course, the water passes
from the heater to the meter, and with this independent
arrangement the exact quantity is recorded just as it flows
to the boiler. When the meter is installed in the heater,
the flow over the V-noteh may be greater or less momen-
tarily than the amount of water fed to the boilers. The
seventh floor. A 5-in. pipe supplies the main floor and
the basement.
Ventilation for the basement and the toilets is provided,
and effected by motor-driven exhaust fans. The engine
and boiler rooms depend on the pull of the stack for
their supply of fresh air. Cold air from above is drawn
down through the elevator shafts and stairways and in
this particular case also through two ducts leading to grat-
ings in the sidewalk. Fresh air passes across the engine
and boiler rooms on its way to the furnaces, so that the
rooms are maintained at a comfortable temperature. The
stack has been erected in a square easing, with consider-
able clearance between the wads and the shell. Conse-
quently, there is a free passage for the air from the boiler
room to the roof, so that the ventilation is continuous
Fig. 6. Vacuum and House Pumps, Opex Heatee axd V-Notch Meter
flow over the weir is the amount recorded on the chart,
so that instantaneous readings and the actual boiler feed
may not check, although either system over a period of
time will record the same amount.
Another feature, not as common as it should be. is the
provision of a small auxiliary pump to relieve the fire
pump. Any slight unbalancing of pressure is cared for by
the small pump. The fire pump is maintained ready for
instant duty and is automatically cut into service when
the capacity of its auxiliary is exceeded.
Heatixc axd Ventilation
To heat the building, 21,408 sq.ft. of direct radiation
has been provided. It is served by a vacuum system of
the Van Auken type, with overhead distribution. Every-
thing above the main floor is taken care of by a 10-i'n.
riser that distributes downward from the attic on the
whether the dampers to the furnaces are open or closed.
The same system has been applied to the McCormick
Building with wonderful success. The engine and boiler
rooms are exceptionally cool. The air currents were
studied by means of silk flags hung from wires stretched
across the room. In this way the openings for air admis-
sion were properly located and any necessity for deflectors
to send the air to all parts of the room was made evident.
The same procedure must be followed in the new building
under discussion. The air currents common to the build-
ing must be established, and proper methods adopted to
produce uniform distribution and satisfactory ventilation.
To heat the hallways tfie same principle was applied,
hut this time utilizing the pull of the building. Vento
coils are placed within inclosures off the hallways, and
through grills fresh air from the street is drawn over the
heating surface into the hallways. This relieves the dif-
June 8, 1915
POWE B
Fn:. :. Fkont View of Switchboard, Showing Vertk il-Type Cibj tit-Breakers
ference in pressure between the interior and the exterior
of the building, and when the doors are opened uo great
quantity of cold air is drawn in. The hall is maintained
at a satisfactory temperature, and in this regard the usual
difficulties are eliminated.
Elevatob Details
The elevators for the building are of the 1 to 1 gearless
traction type. Five are passenger cars having a capacity
of 2500 lb. at a speed of 550 ft. per niin. The sixth ele-
vator is for freight service. Its capacity and normal speed
are the same, but heavy lifts may be effected at slow -peed
by the use of an extra 6000-lb. counterweight. All of
the ears are driven by 220-volt, 34-hp. motors having a
rated speed of 58.5 r.p.m. The ears have interlocking
that must be closed to within 4 in. before motion is
possible. There is also a special hoard for recording the
stops and signals.
For service between the main floor and the basement
there is a tOOO-lb. hydraulic lift, operating on a water
pressure of 125 lb. The equipment, consisting of pres-
sure tanks, a motor-driven pump and a small air com-
ply ssor belted to the pump shaft, is located in the engine
room. Near-by is a small air compressor, which is motor-
Fro. 8. Reab View of Switchboard, Showing Simplicity of Popper Work behind Feeder Panels
ro
POWER
Vol. -11, No. 2c
driven and supplies air at 100 lb. pressure for blowing the
dust from the switchboard, generators and other equip-
ment of the plant.
Switchboard Equipment
The switchboard is an excellent example of a modern
installation. It is equipped with the latest instruments
and lighted by means of reflectors above the panels, but
the feature which distinguishes it from the ordinary is
the use of vertical-type circuit-breakers on the feeder cir-
cuits. These breakers are connected directly to the bus-
bars so that intermediate connections and fuses are elim-
inated. This results in an unusually simple arrangement
hark of the hoard and effects a considerable saving in cop-
per. The circuit-breakers are of the interlocking type.
machines or on one machine, as desired. The lower stud
of each breaker is connected to a bus. The upper stud is
carried hark oi' the bus, and a bar connection extends
directly down to the terminal board. It may he noticed
that all of the feeders terminate on panels at the bottom
of the switchboard and that no flexible copper leads are
used save those for the instruments. It is evident that
the copper work is all straight-run and the arrangement
unusually simple.
Frank IT. Getchell, electrical engineer for Holabird &
Roche, architects for the building, is the designer of the
switchboard and the remainder of the electrical equip-
ment. The mechanical equipment of the plant and build-
ing was laid out by John B. Blake, mechanical engineer
for the same company, under the supervision of M. T.
No. Equipment Kind
i Boilers Scotch-
PRINCIPAL EQUIPMENT ( >F LUMBER EXCHANGE BUILDING PLANT
Size Use Operating Conditions
200-hp.. Generate steam 160 lb- press., natural draft stokers
4 Stokers Side-feed 53 sq.ft. grate. . Serve boilers 45-deg. grates. 50 per rent, air space.
2 Pumps Simplex 7x6£xl0-in.. . Feed boilers 100 lb. steam press
4 Draft gages. . Differential Measure boiler draft Four connections
1 Rubbish burn-
er Hot-water boiler Burn waste from building Water head 130 lb
1 Conveyor Screw 10 tons per hr. . . . Coal from hopper to ele-
vator Motor-driven
1 Conveyor Bucket 1(1 tons per hr. . . Coal from screw conv. to
bunkers Motor-driven
1 Scale Track Weigh coal to furnaces
1 Sewage ejectoi Duplex-electric. Raise sewage to sewer Operated by 2 C.-W. 7. 5-hp. motors
1 Pump Centrifugal 10-in. suction, 5-
iti discharge For emergency sewage Driven by Wait turbine
1 Engine Four-valve pop-
pel 22x32-in Main generating unit 160 lb. steam, 150 r.p.m
1 Generator Direct-current. . . 300-kw Main generating unit 240 volts, 150 r.p.m
1 Engine Four-valve pop-
pet lSx3C-in Main generating unit 160 lb- steam, 150 r.p.m
1 Generator. .... Direct-current.. . 200-kw Main generating unit 240 volts, 150 r.p.m
1 Turbine Single-stage im-
pulse. 100-kw Main generating unit... . 160 lb. steam, 2200 r.p.m
1 Generator Direct-current. . 100-kw. . Main generating unit. . . 240 volts. 2200 r.p.m
2 Balance sets 115 volts, 20 amp Balance three-wire system 1000 and 1150 r.p.m
1 15 volts, 40 amp
1 Switchboard* . Slate 12-panel Control and distribution
current
24 Circuit break-
ers I.T.E. "Direc-
tite" Feeder pant-Is , .„
3 Circuit break-
ers I.T.E Generator panels
1 Heater. ...... Sorge-Cochrane,
open 500-hp Heat feed water Exhaust steam
1 Meter V-notch Record boiler feed
2 Heaters Closed 1200-gal. pet hr. , Hot water for house . Exhaust steam
2 Pumps . . Vacuum . ^xl2xl2-in. lb -at inn >v-t>-in 1 ill Mb. steam.
1 Pump Simplex 7x6] x 10-in House service 160 lb. steam, head 130 lb
1 Pump Tiiplex fixS-in. . House pump Driven by 15-hp. C.-W. motor, S00 r.p.m
1 Pump Underwriters. . . 14x7!xl2-in . . Fire service 160 lb. steam
1 Pump Duplex 6x4x6-in Auxiliary to fire pump ...
1 Air compressor Single-stage 8x8-in Comp. air for cleaning. . . . Driven by 15-hp C.W. motor. S00 r.p.m., 100
lb. press
6 Elevators 1 to 1 gearless
traction 2500-1 b Serve building 550 ft. per min., 34-hp. motors
1 Lift Hydraulic 400O-lb First floor to basement . . Water pressure 125 lb
1 Pump Triplex 4x60-in Serve hydraulic elevator. . Driven by 5-hp. C.-W. motor
1 Oiling system . Pump and gravi-
ty Lubricate generating units Filter, gravity tank and complete system ...
2 Cylinder lubri-
cators Three-feed . . . For main engines Driven from layshaft
7 Cylinder lubri-
cators For steam pumps
*Weston ammeters and voltmeters, Sangamo wattmeters, Esterline graphic ammeter and voltmeter.
Maker
Springfield Boiler & Manufactur-
ing Co.
McKenzie Furnace Co.
(Marsh) American Steam Pumi
Co.
L. M. Ellison
Kewanee Boiler Co.
Webster Engineering Co.
Webster Engineering Co.
I ngineering Co.
Yeomans Bros. Co.
Henry R. Wortbington
H. H. Wait
H. H. Wait
Crocker-Wheeler Co.
The Cutter Co.
The Cutter Co
Harrison Safety Boiler "Works
Harrison Safety Boiler Works
W. Raratrwaneth & Son
International Steam Pump Co
American Steam Pump Co.
Deane Steam Pump Co.
International Steam Pump Co.
International Steam Pump Co.
Chicago Pneumatic Tool Co.
Otis Elevator Co.
Otis Elevator Co.
Deane Steam Pump Co,
Richardson-Phenix Co.
Richardson-Phenix Co.
Richardson-Phenix Co.
nonclosing on overloads, and as the busses may be run
close to the board, studs of standard length are used.
For lighting, the distribution is three-wire and the
power circuits are two-wire. As a consequence two- and
three-pole circuit-breakers are employed, but for the sake
of uniformity the positive poles at the top, the negative
poles at the bottom and the operating handles at the
center have all been placed in line. The generator panels
are equipped with overload, no-voltage and time-limit
release-type circuit-breakers in which the poles are ar-
ranged horizontally. The three busses are carried directly
across the board to the lighting panels and independent
positive and negative busses extend all the way across to
the power panels. The two sets of busses are brought to-
gether by means of a suitable tie-switch. It is thus
possible to carry the power and lighting loads on separate
I\ human, chief engineer of the McCormick estate. C. G.
Harding is the chief operating engineer in charge of the
plant.
B.t.u. to Calories — To convert B.t.u. per pound to calories
per kilogram, divide the number of B.t.u. by 1.8; to convert
calories per kilogram to B.t.u. per pound, multiply the
calories by 1.8.
Pressure Drop in Steam Lines is comparable with line
drop in electric distribution systems, which is known to be
energy lost, but the desired terminal voltage is obtained and
the drop compensated for by" a slight increase of voltage at
the source or apparatus designed to use the lower voltage.
Feeders or steam lines large enough to cause no drop are
not feasible; the amount of drop to be permitted is the
variable quantity. The greats radiation loss from excessively
large steam line-' *ias no counterpart in the electric-distribu-
tion analogy.
June S, 1915
POWER
!7j
3P© L>©!
nini
It T. M. Rome
!©4©if
SYNOPSIS — The arti<I<- describes a method of
finding the core loss of a serif* motor by test with
the aid of a motor-dynamometer.
The losses in a motor or generator are: The field
loss F, due to the heat generated in the field windings by
the field current; the armature loss A. due to the heat
generated in the armature windings; the loss in the
brushes; stray power hiss S, which includes eddy current
and hysteresis losses, chiefly in the armature core; and
losses due to friction in the hearings, at the brushes, and
windage, or air friction.
The heat losses can he calculated from the equation,
watts lost = J2R
where R is the resistance of the part under consideration
and / the current flowing in that part. The resistance
should be that at running temperature.
Stray power loss cannot lie accurately calculated by any
simple data and is usually determined by experiment. In
this article the author will give a simple and reasonably
accurate means of finding the core loss in a series motor.
It is necessary to know all the losses mentioned in order
to find the efficiency of a motor or generator. Core-loss
tests are made by the manufacturers on one machine for
40 80 IZO 160 200 Z40
Amperes
Fig. 1. Speed Curve for 500-Tolt Series Motor
each type and class, and hold, with but slight variation--,
for all machines of the same size and design. While it is
usually impractical to make these tests outside a labora-
tory, still it is interesting to know how they are carried
out. Following is the method employed by one of the
.largest manufacturers of electrical machinery in this
country :
I be motor or generator under test is mounted on the
tesi -tand and is connected by means of a sleeve coupling
i" a similar motor which runs as a generator and fur-
nishes the load. Holding the motor voltage constant, the
load is varied from about 30 to 175 per cent, of normal,
and the corresponding speeds are carefully observed.
COUPLING DRIVING MOTOR
Fig. 2. Showing Driving Motor axd Bearings which
Allow Frame to Turn About lis Axis
From these data a speed curve is obtained having revolu-
tions per minute as ordinates and current, or load, as ab-
scissas; such a curve is shown in Fig. 1.
The motor is next disconnected from the position men-
tioned and is connected to a motor dynamometer, as
shown in Fig. 2. The motor of the latter is mounted on
ball bearings so that the frame is free to turn as well as
the armature. A lever arm is attached to the side of the
frame, and from this a spring-balance is suspended, the
other end of the balance being fastened to the floor.
This spring-balance furnishes the force necessary to 1
the frame from revolving. The machine under test is
linn run as a separately excited generator operating at
zero load.
About five speeds are selected from the speed curve,
and runs are made at each, using five different field exci-
tations for each speed. At the lower speeds the field cur-
rent on the generator will, of course, have to be higher
than at high speeds. Having decided upon the speeds
and corresponding field excitations, the field of the motor
under test is completely demagnetized by means of a re-
versing switch installed for that purpose, and the driving
motor is started at the lowesl speed decided upon. The
set is now run until the reading upon the spring-balance
is constant. This first reading takes care of all fric-
tion losses in the driving motor as well as the motor
under test.
The maximum field current is now thrown on and.
keeping the speed constant at the first, value, the pull on
the spring-balance is noted. The four other values of
field current are applied consecutively and the corres-
ponding spring-balance readings recorded. The fields are
then demagnetized as before by momentarily reversing the
field current and a second friction reading is taken, which
should check exactly with the first. This process is sim-
ply repeated for the higher speeds and their correspond-
ingly lower field currents.
The watts loss in the armature can now be calculated.
The net pull on the spring-balance, that is, the reading
with the field excited minus that with the demagnetized
field, is a measure of the watts lost. The length of the
arm from the spring-balance to the center line of the
row e it
Vol. 41, No. 23
motor shaft can be measured, and the other values in the
equation
Watts =
■2-lnW
33,000
X 746
are known, where
/ = Length of the lever arm in feet :
n = Revolutions per minute of the driving motor;
W = Xet pull on the scales in pounds.
From the data thus obtained five curves may be drawn.
one for each speed, having watts for ordinates and field
current for abscissas. These should be drawn on the
same curve sheet as was used for the speed curve; see
Fig. 3.
The core-loss curve may now be readily drawn in. Sup-
posi desired to find the point where the core-loss
MOO
1Q00
300
800
700
600
500
400
300
200
100
0
2200
2000
1800
1600
1400
1200
1000
800
600
EOO
0,
\
1 \
y
^L
-S-
f
at
/
oo i
• '*s
/
s
/\ L&
JS
11/
/! ^x---««_
;
soo
-ll/A
7££er£mu
VbJFs ■
%
f // /
Y
0 40
Fig. 3. Core-Loss axd Speed Curves
120 160 £00 240
Amperes
curve crosses the 500-r.p.m. curve. Find the field cur-
rent corresponding to 500 r.p.m. from the speed curve;
this is about 140 amp. The point where this field current
crosses the 500 r.p.m. curve will be one point on the core-
loss curve.
A somewhat quicker way. but not as accurate, is to find
the field current corresponding to a given speed and then
run the motor under test at this speed and field excitation.
The pull on the spring-balance is recorded as before and
the watts lost calculated. This will give a point on the
core-loss curve corresponding to the field current used;
other points may be obtained in a similar manner.
The first method is the more accurate inasmuch as any
error will quickly show in the core-loss curves taken at
constant speed.
As will be seen, tne core loss of a series motor varies
greatly with load. With a shunt machine, on the other
hand, it is practically constant irrespective of load.
The advantage of the method described lies in the fact
that the electrical calculations are reduced to a min-
imum. It is not necessary to know the input to the driv-
ing motor or to know what losses there are in it.
The curves here shown are taken from a 50-hp. 500-
volt G. E. railway motor.
As Usual, No Mtstest When Found Out
On arriving at the plant in response to a distress call
from the night man, I inquired what was wrong. He
placed his hand gingerly on the low-pressure valve-chest
cover and informed me it was hot. It was quite evident
from the smell in the room that something was hot. He
then told me that the engine had not been running evenly,
but he could locate no other "trouble."
Upon examination I found the pedestal bearing hot
and the bronze bearing gripping, causing the engine to
slow down and then race. The oil drain-eock had been
accidentally opened while cleaning the engine, and al-
though the machine had been running over an hour, the
so-called engineer had not discovered the lack of oil, but
instead was looking for "something mysterious." — F. E.
Wood, Whitinsville, Mass.
Absurdity Not Always Funny
I read with some amusement the letter by Mr. New-
bury in the issue of Mar. 2, under the column headed
"Just for Fun/'' wherein he refers to the blower salesman's
remarks. While the statement was absurd, it does not
sound quite so funny to one who has had the following
experience.
A blower was sold, and the manufacturer was advised
shortly afterward that the plant operator could not run
the blower because it blew the gases out into the boiler
room. Upon investigation he found that the man operat-
ing the plant insisted upon opening the blower valve
to its full extent, regardless of the amount of air required.
As the blower was installed with a fair margin of extra
capacity, it was not ordinarily necessary to ojjerate it at
its full rate. Still, the fireman thought he ought by all
means to do so. even if he spoiled the fire and filled the
boiler room with gas. The main thing in his mind was
to operate at full speed.
Is this experience any less funnv than the other? —
T. L. Hoyt, New York City.
As Good as Ever
In the palmy days of the Mississippi River shipping,
the captain of one of the crack racing boats, the "Natchez,"
I think, was preparing to sail up the river from New
Orleans, and finding that a rival boat was to sail about
the same time, took occasion to impress upon his colored
fireman the importance of having a good head of steam at
starting time.
A few minutes before time to depart the captain
strolled over in front of the boilers and was surprised
to note that the steam gage showed exactly zero.
Naturally he wanted to know why in "hellenblazes"
and several other things the fireman hadn't got up steam,
to which the colored gentleman replied : "Dat's all right.
Cap'n, dat thing's done been around once."
The above is a "wheeze" for which the writer can not
vouch, on account of its npt being true; still, it man
interest such readers as hare not heard it before. But
if the steam gages had the stop pin taken out or were
made so they could go around the second time we would
be willing to believe the story, judging from some known
incidents. — L. A. States, Gastonia, N. C.
June 8, 1915
1' U W E R
773
Horsepower ComisHamife for Gc
Type F §tes_iii_i_-FI_ow Metier
By Hubert E. Collins
SYNOPSIS — This article contains horsepower
tables to be used with the G. E. si cam -flow meter
ivith several sizes of steam pipes. The tables are
not corrected for moisture or for any other inner
mechanism than a No. 6.
Chart readings taken from the G. E. Type F steam-flow
meter must be computed by the method laid down in the
instruction book No. Y 328, Sept., 1913, which also
contains diagram No. 11, with the formula as shown
herewith.
Meters not having the integrating attachment require
considerable computation to figure the daily output reg-
istered. In order that the average of a day's run can be
arrived at, the chart reading should be figured at least
every half-hour. To get the rate of flow at any half-
hour period requires four computations. If the factory
has a number of meters, the work is considerable.
The accompanying tables are figured for a No. 6 inner
mechanism General Electric Type F steam-flow meter for
which the constant K cp on the chart is 1.000. To use
the tables with any other inner mechanism, multiply the
reading from the table by the constant Kcp tor that one.
These tables do not take into consideration the moist-
ure of the steam or superheat, and any reading from
them must be corrected for one of these. This means
that it is necessary to multiply by constant K^
To illustrate the calculation of one of these figures in
the table, let us figure the rated boiler horsepower pass-
ing through a L2-in. pipe at 1 00-11). pressure, the chart
reading being 2.
Then
K, = 0.835;
A'3 = 15,750;
Lcp
1.000.
1 5,750 X 0.835 = 13,151 lb. of straw per hour rate
13,151 ;•;..,. ;
30
TABLE 1.
1 1 1 i U SEPOWER CONSTANTS FOR "TYPE F." G.E. STEAM
FLOW
METER
Gage
Pipe Sizes
Pressure
12-Im.
10-In.
8-In. 6-In.
4-In
3-1 n.
20
241
161
95 53
21
12.2
25
260
173
102 57
23
13.2
30
275
183
108 61
24
14
35
2SS
192
113 64
25
14.6
40
301
201
118 67
23
15.3
45
315
210
124 70
28
16
50
328
218
129 72
29
16.6
55
341
227
134 75
30
17.3
60
354
236
139 78
31
18
65
364
243
143 81
32
18.5
70
375
250
147 83
33
19
75
385
257
151 S5
34
19.6
SO
396
264
156 88
35
20
85
406
271
160 90
36
20.6
90
417
278
164 92
37
21.2
95
427
285
168 95
38
21.7
100
438
292
172 97
38.9
22.2
105
446
207
175 99
39.6
22.6
no
456
304
179 101
40
23.2
115
464
309
182 103
41
23.6
120
472
315
186 105
42
24
125
483
322
190 107
42.8
24.5
130
490
327
193 109
43.6
24.9
135
498
332
196 110
44.3
25.3
140
506
337
199 112
45
25.7
145
514
343
202 114
45.7
2'i.l
150
525
350
206 116
46.6
26.6
_ _ _ _ _______ .__
| |
*" 09 =Tr^
Moisture, no M-L__
10 ■»"""" /BOOOC
-,cN0>^' - t TIT
07 >-r / TIT
vi =>- 7
n* ** / |i i
vl __ C, 1 1 1"
Tr*PE VrB'ORDIN&FLOW m 1 \ /
1 | MET LI III / rVSf'''
o±t : ows i / - .v\R/ - i,
<ri Z 0.510 K3 1 II | / y
= ■* 4 o 0717 / ~ II
Zi** c *= noJ>« / ^^
£UJ 5 ' " 0.&Q0 ,n/n _ „** ,nmn
+ oV/r mnn i'900 ' ^ 'mo
Jcl 7 1 no <1 ' ■■"" Measured Internal Pipe Diameter in Inches
d t q- o » j | iu, j , \c ih , | w , io _u; _. | « _o do ou
Diagram No. 11, for Use with Type V Recording Steam-Flow Meter
:;;
POWER
Vol. 41, No. 23
For the purpose of calculating the tables the following
constants are taken from the chart:
Constants
. internal diameter = 15,750
. internal diameter = 10,500
. internal diameter = 6,200
. internal diameter = 3,500
. internal diameter = 1,400
. internal diameter = S00
K,
100
105
110
115
120
125
130
2-in
pipe
=
llj-in
0-iii
pipe
9»-m
s-ii,
pipe
=
7 : -in
t.-Sl.
pipe
=
55-in
4-in
pipe
3i-iu
O-lii
pipe
=
2J-in
Gage
Gage
Gage
Pressure Constants
Pressure
Constants
Pressure
Constants
20
—
0.46
65
=
0.695
110
=
0.87
25
0.495
70
0 715
115
0.885
30
=
0.525
75
=
0 735
120
=
0.9
35
0.55
80
0 755
125
0 92
40
=
0 575
85
=
0 775
130
=
0.935
45
0 6
90
0 795
135
0.95
50
ii 625
95
0 815
140
0 965
55
0.65
100
0.835
145
0 98
60
=
0 675
105
=
0.85
150
=
1.000
1
241
260
275
2SS
301
315
328
341
354
364
375
385
396
406
417
427
438
446
456
464
472
483
490
498
506
1.5
362
390
412
432
451
472
70S
724
735
747
482
520
550
576
602
630
656
682
708
792
812
S34
854
876
892
912
928
944
996
1012
102S
1050
2.5
602
650
11-7
720
752
787
820
852
885
910
937
962
990
1015
1042
1067
1095
1115
1140
1160
1180
1207
1225
1245
1265
1285
1312
TABLE 2. HORSEPOWER PER HOUR TRANSMITTED
Pipe Diameter = 12 In.
Chart Reading
723
780
825
864
903
945
984
1023
1062
1092
1125
1155
1188
1218
1251
1281
1314
1338
1368
1392
1416
1449
1470
1494
1518
1542
1575
3.5
843
910
962
1008
1053
1102
1148
1193
1239
1274
1312
1347
1386
1421
1459
1494
1533
1561
1596
1624
1652
1690
1715
1743
1771
1799
1837
964
1040
1100
1152
1204
1260
1312
1364
1416
1456
1500
1540
15.S4
1624
166S
1708
1752
1784
1824
1S56
1SS8
1932
1960
1992
2024
2056
2100
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
1084
1205
1325
1446
1566
1687
1S07
1928
2048
2169
2289
2410
1170
1300
1430
1560
1690
1820
1950
2080
2210
2340
2470
2600
1237
1375
1512
1650
1787
1925
2062
2200
2337
2475
2612
2750
1296
1440
1584
1728
1-72
2016
2160
2304
2448
2592
2736
2880
1354
1505
1655
1806
1956
2107
225 7
2408
2558
2709
2859
3010
1417
1575
1732
1890
2047
2205
2.11.2
2520
2677
2835
2992
3150
1476
1640
1S04
1968
2132
2296
2460
2624
2788
2952
3116
3280
1534
1705
1875
2046
2216
2387
2557
2728
2898
3069
3239
3410
1593
1770
1947
2124
2301
2478
2655
2832
3009
3186
3363
3540
1638
1820
2002
2184
2366
254 s
2730
2912
3094
3276
3458
3640
1687
1875
2062
2250
2437
2625
2S12
3000
3187
3375
3562
3750
1732
1925
2117
2310
2502
2695
2—7
3080
3272
3465
3657
3S50
1782
1980
2178
2376
2574
2772
2970
3168
3366
3564
3762
3960
1827
2030
2233
2436
2639
2842
3045
.12 1-
3451
3654
3857
4060
1S76
2085
2293
2502
2710
2919
3127
3336
3544
3753
3961
4170
1921
2135
2348
2562
2775
2989
3202
3416
3629
3843
4056
4270
1971
2190
2409
2628
2847
3066
3285
3504
3723
3942
4161
4380
2007
2230
2453
2676
2899
3122
3345
3568
3791
4014
4237
4460
2052
2280
2508
2736
2964
3192
3420
3648
3876
4104
4332
4560
20SS
2320
2552
2784
3016
3248
3480
3712
3944
4176
4408
4640
2124
2360
2596
2S32
3068
3304
3540
3776
4012
4248
4484
4720
2173
2415
2656
2-9-
3139
3381
3622
3864
4105
4347
4588
4830
2205
2450
2695
2940
3185
3430
3675
3920
4165
4410
4655
4900
2241
2490
2739
2*'—
3237
3486
3735
3984
4233
4482
4731
4980
2277
2530
2783
3036
3289
3542
3795
4048
4301
4554
4807
5060
2313
2570
2827
3084
3341
3598
3855
4112
4369
4626
4883
5140
2362
2625
2887
3150
3412
3675
3937
4200
4462
4725
4987
5250
TABLE 3. HORSEPOWER PER HOUR TRANSMITTED
Pipe Diameter = 10 In.
Chart Reading
120
125
130
135
140
210
218
227
236
243
250
257
264
271
278
2-5
292
297
304
309
315
322
327
332
337
343
350
241
259
274
288
301
315
327
340
354
364
375
385
396
406
417
427
438
445
456
463
472
483
490
498
505
514
322
346
366
3S4
402
420
436
454
472
4S6
500
514
528
542
556
570
584
594
608
618
630
644
654
664
674
6S6
700
402
432
457
480
502
525
545
567
590
607
625
642
660
677
695
712
730
742
760
772
787
805
483
519
549
576
603
630
654
681
708
729
750
771
792
813
834
855
876
891
912
927
945
966
981
996
1011
1029
1050
563
605
640
672
703
735
763
899
924
Ml-
973
997
1022
1039
1064
1081
1102
1127
1144
1162
1179
1200
1225
732
768
804
840
872
908
944
072
1000
1028
1056
10S4
1112
1140
116S
11 —
1216
1236
1260
128S
1308
1328
1348
1372
1400
724
778
823
864
904
945
981
1021
1062
1093
1125
1156
1188
1219
1251
12S2
1314
1336
1368
1390
1417
1449
1471
1494
1516
1543
1575
805
865
915
960
1005
1050
1090
1135
1180
1215
1250
12S5
1320
1355
1390
1425
1460
14S5
1520
1545
1575
1610
1635
1660
16S5
1715
1750
8S5
951
1006
1056
1105
1155
1199
124S
1298
1336
1375
1413
1452
1490
1529
1567
1606
1633
1672
1699
1732
1771
1798
1826
1853
1886
1925
966
1038
In—
1152
1206
1260
1308
1362
1416
1458
1500
1542
1 58 i
1626
Mil-
1710
1752
1782
1-21
1 -.'4
1890
1932
1962
1992
2022
2i >5-
2100
1046
1124
1189
1248
1306
1365
1417
1475
1534
1579
1625
1670
1716
1761
1807
1S52
l.-li-
1930
1976
200S
2047
2093
2125
2158
2190
2229
2275
1127
1211
1281
1344
1407
1470
1526
15S9
1652
1701
1750
1799
1848
1897
1946
1995
2128
2163
220.5
2254
22S9
2324
2359
2401
2450
7.5 8
1207 1288
1297 1384
1372 1464
1440 1536
1507 1608
1575 1680
1635 1744
1702 1816
1770 1888
1822 1944
1S75 2000
1927 2056
1980 2112
2032 216S
2085 2224
2137 2280
2190 2336
2227 2376
22S0 2432
2317 2472
2362 2520
2415 2576
2452 2616
2490 2656
8.5
9
1368 1449
1470 1557
1555 1647
1632 1728
1708 1809
1785 1890
1853 1962
1929 2043
2006 2124
2065 2187
2125 2250
2184 2313
2244 2376
2303 2439
2363 2502
2422 2565
2482 2628
2524 2673
2584 2736
2626 2781
2677 2835
2737 2898
2779 2943
2822 2988
2864 3033
2915 3087
2975 3150
9 5
11,
1529 1610
1643 1730
1738 1830
1824 1920
1909 2010
1995 2100
2071 2180
2156 2270
2242 2360
2308 2430
2375 2500
2461 2570
250S 2640
2574 2710
2641 2780
2707 2850
2774 2920
2821 2970
2888 3040
2935 3090
2992 3150
3059 3220
3106 3270
3154 3320
3201 3370
3258 3430
3325 3500
TABLE 4. HORSEPOWER PER HOUR TRANSMITTED
Pipe Diameter = S In.
r Chart Reading
3.5 4 4 5 5 5.5 6 6.5 7
100
105
110
115
120
108
113
118
134
139
143
147
151
156
160
164
208
214
220
226
234
240
246
252
258
262
268
273
279
285
289
294
298
303
309
190
204
216
226
236
248
258
268
278
2S6
294
302
312
320
328
336
344
350
358
364
372
3S0
3S6
392
398
404
412
237
255
270
282
295
310
322
335
347
357
367
377
390
400
410
4211
430
437
447
455
465
475
482
490
497
505
515
306
324
339
354
372
387
402
417
429
441
453
516
525
537
546
55S
570
579
5—
597
606
618
332
357
378
395
413
434
451
469
486
500
514
528
546
560
574
:,—
602
612
626
637
651
3S0
408
432
452
172
496
516
536
556
572
-,—
604
624
640
656
672
il—
700
716
728
744
760
772
784
796
427
459
486
508
531
558
580
603
625
643
661
679
702
720
738
756
774
787
805
819
837
855
868
882
895
909
927
510
540
565
590
620
645
670
695
715
735
780
800
820
840
860
875
895
910
930
950
965
980
995
1010
1030
522
561
594
621
649
6S2
709
737
764
7S6
-0-
830
858
S-ll
902
924
946
962
984
1001
1023
1045
1061
1078
1094
I'll
1133
570
612
648
678
7ms
744
774
804
834
858
882
906
936
960
984
1008
1032
1050
1074
1092
1116
1140
1158
1176
1194
1212
1236
663
702
734
767
806
838
871
903
929
955
9S1
1014
1040
1066
1092
1118
1137
1163
1183
1209
1235
1254
1274
1293
1313
1339
903
938
973
1001
1029
1057
1092
1120
1148
1176
1204
1225
1253
1274
1302
1330
1351
1372
1393
1414
1442
712
765
810
847
885
930
967
1005
1042
1072
1102
1132
1170
1200
1230
1260
1290
1312
1342
1365
1395
1425
1447
1470
1492
1515
1545
760
816
864
904
944
992
1032
1072
1112
1144
1176
1208
124S
12-11
1312
1344
1376
1400
1432
1456
1488
1520
1544
156S
1592
1616
1648
807
867
918
960
1003
1054
1096
1139
1181
1215
1249
1283
1326
1360
1394
142S
1462
1487
1521
1547
1581
1615
1640
1666
1691
1717
1751
855
918
972
1017
1062
1116
1161
1206
1251
1287
1323
1359
1404
1440
1476
1512
15 IS
1575
1611
163S
1674
1710
1737
9.5
902
969
1026
1073
1121
1178
1225
1273
1320
1358
1396
1434
1482
1520
1558
1596
1634
1662
1700
1729
1767
1805
1S33
1S62
1S90
1919
1957
10
950
1020
1080
1130
1180
1240
1290
1340
1390
1430
1470
1510
15P0
1600
1640
1680
1720
1750
1790
1820
1S60
1900
1930
1960
1990
2020
2060
June 8, 1915
POWER
775
With these constants table No. 1 is figured. This table
gives the horsepower for the given pipe sizes and steam
pressures for a reading of 1 on the meter chart. When
using this table, multiply the chart reading by the con-
stant corresponding to the pipe sizes and gage pressure.
Then correct for moisture or superheat. If another in-
ner mechanism than a No. 6 is used, correct for that, as
already stated.
The integrating attachment to one of these meters does
away with the necessity of calculating the steam flow at
stated periods and averaging the result, or adding them
to get the total. The device gives the total chart read-
ing, which is multiplied by the result of the calculations
given with Diagram No. 11.
With the integrating device the following formula is
given for Type F meter with nozzle plug:
Total flow in lb. =
net dial reading X 4.7 X iT, X K% X -g"8 X K4 X Kcp
revolutions of chart in 24 hr.
TABLE 5.
HORSEPOWER PER HOUR TRd
NSMI1
'TED
Pipe
Diameter
= 6 In
Chart Reading
essure
1
1.5
2
2.5
3
3 5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
20
53
79
106
132
159
185
212
238
265
291
318
344
371
397
424
450
477
503
530
25
57
85
114
142
171
199
228
256
285
313
342
370
399
427
456
484
513
.541
570
30
61
91
122
152
183
213
244
274
305
335
366
396
427
457
488
518
549
579
610
35
64
96
128
160
192
224
256
288
320
352
384
416
44S
480
512
544
576
608
640
40
67
100
134
167
201
234
268
301
335
368
402
435
469
502
536
569
603
636
670
45
70
105
140
175
210
245
280
315
350
385
420
455
490
525
560
595
630
665
700
50
72
108
144
ISO
216
252
288
324
360
396
432
468
504
540
576
612
648
684
720
55
75
112
150
187
225
262
300
337
375
412
450
487
525
562
600
637
675
712
750
60
78
117
156
195
234
273
312
351
390
429
468
507
546
585
624
663
702
741
780
65
81
121
162
202
243
283
324
364
405
445
486
526
567
607
648
688
729
769
810
70
83
124
166
207
249
290
332
373
415
456
498
539
581
622
664
705
747
788
830
75
85
127
170
212
255
297
340
382
425
467
510
552
595
637
680
722
• 765
807
850
80
88
132
176
220
264
308
352
396
440
484
528
572
616
660
704
748
792
836
880
85
90
135
180
225
270
315
360
405
450
495
540
585
630
675
720
765
810
855
900
90
92
138
184
230
276
322
368
414
460
506
552
598
644
690
736
782
828
874
920
95
95
142
190
237
285
332
380
427
475
522
570
617
665
712
760
807
855
902
950
100
97
145
194
242
291
339
388
436
485
533
582
630
679
727
776
824
873
921
970
105
99
148
198
247
297
346
396
445
495
544
594
643
693
742
792
841
891
940
990
110
101
151
202
252
303
353
404
454
505
555
606
656
707
757
808
858
909
959
1010
115
103
154
206
257
309
360
412
463
515
566
618
669
721
772
824
875
927
978
1030
120
105
157
210
262
315
367
420
472
525
577
630
682
735
787
840
892
945
997
1050
125
107
160
214
267
321
374
428
481
535
588
642
695
749
802
856
909
963
1016
1070
130
109
163
218
272
327
381
436
490
545
599
654
708
763
817
872
926
981
1035
1090
135
110
165
220
275
330
385
440
495
550
605
660
715
770
825
880
935
990
1045
1100
140
112
168
224
280
336
392
448
504
560
616
672
728
784
840
896
952
1008
1064
1120
145
114
171
228
285
342
399
456
513
570
627
684
741
798
855
912
969
1026
1083
1140
150
116
174
232
290
348
406
464
522
580
638
696
754
812
870
928
986
1044
1102
1100
TABLE 6.
HORSEPOWER PER HOUR TRANSMITTED
Pipe Diameter = 4 In.
Chart Reading
essure
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
20
21
31
42
52
63
73
84
94
105
115
126
136
147
157
168
178
189
199
210
25
23
34
46
57
69
80
92
103
115
126
138
149
161
172
184
195
207
218
230
30
24
36
48
60
72
84
96
108
120
132
144
156
168
180
192
204
216
228
240
35
25
37
50
62
75
87
100
112
125
137
150
162
175
187
200
212
225
237
250
40
26
39
52
65
78
91
104
117
L30
143
156
169
182
195
208
221
234
247
260
45
28
42
56
70
84
98
112
126
140
154
168
182
196
210
224
238
252
266
280
50
29
43
58
72
S7
101
116
130
145
159
174
188
203
217
232
246
261
275
2! in
55
30
45
60
75
90
105
120
135
150
165
180
195
210
225
240
255
270
285
300
60
31
46
62
77
93
108
124
139
155
170
186
201
217
232
248
263
279
294
310
65
32
48
64
80
96
112
128
144
160
176
192
208
224
240
256
272
288
304
320
70
33
49
66
82
99
115
132
148
165
181
198
214
231
247
264
280
297
313
330
75
34
51
68
85
102
119
136
153
170
187
204
221
238
255
272
289
306
323
340
80
35
52
70
87
105
122
140
157
175
192
210
227
245
262
280
297
315
332
350
85
3fi
54
72
90
108
126
144
162
180
198
216
234
252
270
288
306
324
342
360
90
37
55
74
92
111
129
148
166
185
203
222
240
259
277
296
314
333
351
370
95
38
57
76
95
114
133
152
171
190
209
228
247
266
285
304
323
342
361
380
100
38.9
58.3
77.8
97.2
116 7
136.1
155.6
175
I'll
5
213.9
233.4
252.8
272.3
291.7
311.2
330.6
350.1
369.5
389
105
39.6
59.4
79.2
99
118.8
138.6
158.4
178.2
198
217.8
237.6
257.4
277.2
297
316.8
336.6
356.4
376.2
396
110
40
60
80
100
120
140
160
180
200
220
240
260
280
300
320
340
360
380
400
115
41
61
82
102
123
143
164
184
205
225
246
266
287
307
328
348
369
389
410
120
42
63
84
105
126
147
16f
189
210
231
252
273
294
315
336
357
378
399
420
125
42.8
64 2
85 6
107
128.4
149.8
171.2
192.6
214
235.4
256.8
278.2
299.6
321
342.4
363 . 8
385.2
406.6
428
130
43.6
65 4
87.2
109
130 S
152.6
174 .4
196 2
218
239.8
261.6
283.4
305 2
327
348.8
370.6
392.4
414 2
436
135
44.3
66 4
88.6
110,7
132 9
155
177.2
199,3
221
5
243.6
265.8
287.9
310.1
332 2
354.4
376.5
398.7
420.8
443
140
45
67
90
112
135
157
180
202
225
247
270
292
315
337
360
382
405
427
150
145
45.7
68.5
91.4
114.2
137.1
159.9
182.8
205 . 6
228.
5
251.3
274.2
297
319.9
342.7
365 . 6
388.4
411.3
434.1
457
150
46.6
69.9
93.2
116.5
139.8
163.1
186.4
209.7
233
256.3
279.6
302.9
326.2
349.5
372.8
396.1
419.4
442.7
466
TABLE 7.
HORSEPOWER PER HOUR TRANSMITTED
Pipe Diameter
= 3 In
Chart Reading
essure
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9 5
10
20
12.2
IS. 3
24.4
30 . 5
36.6
42.7
48.8
54.9
61
67.1
73.2
79 3
85.4
91.5
97.6
103.7
109.8
115.9
122
25
13.2
19.8
26.4
33
39.6
46.2
52.8
59.4
66
72.6
79.2
85.8
92.4
99
105.6
112.2
118.8
125.4
132
30
14
21
28
35
42
49
56
63
70
77
84
91
98
105
112
119
126
133
1 Id
35
14.6
21 9
29 2
36.5
43.8
51.1
58.4
65.7
73
80.3
87.6
94.9
102.2
109.5
I10.8
124.1
131 4
138 7
146
40
15.3
22.9
30 6
38.2
45.9
53.5
61.2
68.8
76
5
84.1
91.8
09.4
107.1
lit. 7
122.4
130
137.7
145.3
153
45
16
24
32
40
48
56
64
72
80
8S
96
104
112
120
128
136
144
152
160
50
16 6
24.9
33.2
41.5
49.8
58.1
66.4
74.7
83
91.3
99.6
107.9
116.2
121 5
132.8
141.1
149.4
157.7
166
55
17.3
25.9
34.6
43.2
51.9
60.5
69.2
77.8
86
5
95.1
103 8
112.4
121.1
129.7
138.4
147
155.7
164 3
173
60
18
27
36
45
54
63
72
81
90
99
108
117
126
135
1 11
153
162
171
180
65
18.5
27.7
37
46.2
55.5
64.7
74
83.2
92
5
101.7
111
120.2
129.5
138.7
148
157.2
166.5
175.7
185
70
19
28.5
38
47.5
57
66 5
76
85.5
95
104.5
114
123 . 5
133
142.5
152
161.5
171
lsn :,
190
75
19.6
29.4
39.2
I'l
58.8
Os r,
78.4
88.2
98
107.8
117.6
127.4
137.2
147
156.8
166.6
176.4
1S6 2
196
80
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
85
20.6
30.9
41.2
51.5
61.8
72.1
82.4
92.7
103
113.3
123.6
133.9
144 2
154.5
164.8
175.1
185.4
195.7
206
90
21.2
31.8
42.4
53
63.6
74.2
84.8
95 4
106
116.6
127.2
137.8
148.4
159
169.6
180.2
190.8
201.4
212
95
21.7
32.5
43.4
54,2
65.1
75.9
86.8
97.6
10S
5
119.3
130.2
141
151 '.i
162.7
173.6
184.4
195.3
20%. 1
217
100
22.2
33.3
44.4
55.5
66.6
77.7
88.8
99.9
111
122.1
133 2
144 3
155.4
166.5
177.6
188.7
199.8
210 9
222
105
22.6
33.9
45.2
56.5
67.8
79.1
90.4
101.7
113
124.3
135.6
146.9
158. 2
li i'l 5
Isii 8
192.1
203.4
214.7
226
110
23.2
34.8
46.4
58
69.6
81.2
92.8
104.4
116
127.6
139.2
150.8
162.4
174
Is;, 6
197.2
208.8
220.4
232
115
23,6
35.4
47.2
59
70.8
82.6
94.4
108.2
118
129.8
141.6
153.4
165 2
177
188.8
200.6
212.4
224.2
236
120
24
36
48
60
72
84
96
108
120
132
144
156
168
180
192
204
216
228
240
125
24.5
36.7
49
61.2
73 B
85.7
98
110,2
122
5
134.7
147
159.2
171.5
183.7
196
208.2
220.5
232.7
245
130
24.9
37.3
49.8
62.2
71 7
87.1
99.6
112
124
5
136.9
149.4
161.8
174.3
186 7
199,2
211.6
224.1
236.5
249
135
25.3
37.9
50.6
63.2
75.9
88.5
101.2
113.8
126
139.1
151.8
li.l 1
177.1
189.7
202.4
215
227.7
240.3
253
1 10
25.7
38.5
51.4
64.2
77.1
89 0
102.8
115.6
128
5
141.3
154.2
107
179 9
192.7
205.6
218.4
231.3
244.1
257
145
26.1
39.1
52.2
65 2
78.3
91.3
104.4
117.4
130
5
143.5
156 6
169.6
182.7
195.7
208.8
221.8
234.9
247,9
261
150
26.6
39.9
53.2
66.5
79.8
93.1
106.4
119.7
133
146.3
159.6
172.9
186. 2
199.5
212.8
226.1
239 4
252 7
266
POWE B
Vol. 41, No. 23
The numeral 4.T stands for the integrating dial con-
stant which is given on the naraeplate.
To use these tables the formula is as follows:
Total horsepower =
net dial reading X constant X horsepower from Table 1
revolutions of chart in "'4 hr.
To change to miniber of pounds of .-team, multiply
the above by 30.
If other than No. 6 inner mechanism is used, multi-
ply the above by the constant given in Diagram 11 for
the proper mechanism.
Correct for moisture or superheat.
For example, let us assume the following : The steam-
pipe diameter is 12 in. ; the average steam pressure at
100 lb. equals 43S hp. (Table 1); the integrating-dial
reading for 24 hr. is 30; the dial constant is 4.7; and
the reading of the meter chart in revolutions is 1.
Then
30 X 4.7 X 438
— = 61,758 total horsepower
Where the integrating device is not in use, the Tables
2, 3, 1. 5, 6 and 5 arc of especial use. With these the
horsepower for any chart reading and given pressure can
be read direct; each table is for a given pipe size.
Jimveriler
>to<ti©im
of
SYNOPSIS— The equipment includes nine 2500-
kiv. rotary converters, outdoor transformers and
high-tension switches and special control and pro-
tective apparatus.
The installation of nine 2500-kw. 60-cycle rotary con-
verters at the Little Tennessee Plant of the Aluminum
Company of America at Maryville, Tenn., in addition to
constituting one of the largest 60-cycle rotary-converter
installations in the world, presents a number of interest-
ing features in the arrangement of the controlling and
protective equipment. Energy is brought to the station
by the Tennessee Power Co. over a single-circuit trans-
mission line 70 miles in length, consisting of 400,000-
circ.mil stranded aluminum cables, carried on steel towers
55 ft. in height, the lines being hung from suspension in-
sulators. Temporarily, a transmission voltage of 66,000
is used, which later will be boosted to 110,000 volts.
Two banks of three 3650-kv.-a. 110,000/66,000-volt
outdoor-type single-phase transformers are used to step
down to the converter voltage, four sis-phase machines
Fig. 1. Interior View of Station, Showing Converters and Control Panels
1915
p o w b n
777
operating from independent secondaries on each bank,
with provision for operating one spare unit from any set
of secondaries of either bank. Automatic overload pro-
tection is provided by tbree-pole outdoor oil circuit-
breakers equipped with outdoor condenser-type terminals
and ring-type current transformers. The breakers are
solenoid operated, and are controlled from the control
desk located in the station. The breakers are isolated
from the transmission line by means of three-pole outdoor
disconnecting switches which arc mechanically controlled
by a handle installed in the station. One of these switches
is shown in Fig. 2 between the supports of the transmis-
sion tower. The outdoor lightning arrester of the elec-
trolytic type, shown at the left, provides protection
against lightning.
The low-tension leads from the transformers are carried
directly through the station wall and the six-phase con-
nections are made beneath the floor. The aluminum-
strap bus arrangement shown along the right-hand station
wall in Fig. 1 provides the necessary connections for
transferring the spare converter to any set of secondaries
of either bank of step-down transformers.
The converters are ordinarily started from the 500-volt
direct-current side, although two are arranged so that
alternating-current starting motors may be used. Owing
to the size of the machines and their large overload capac-
ity, the switching equipment for both the alternating-
and the direct-current ends is somewhat unusual in char-
acter. For the control of the alternating-current ends of
the converters, 2500-amp., three-pole, solenoid-operated
automatic carbon circuit-breakers are used, and for the
direct-current ends the control consists of two 5000-amp.,
single-pole, solenoid-operated automatic carbon circuit-
breakers for each machine. The alternating- and the
direct-current panels are located adjacent to each ma-
Fig
Outdoor Switches and Lightning Arresters
chine, thus reducing to a minimum the length of the
main connections. Low-voltage protection is provided
on the alternating-current panels, and protection against
reversal of direct current is secured by reverse-current
relays.
The output of the converters, which is used in the manu-
facture of aluminum, is distributed through a 20,000-amp.
single-pole solenoid-operated automatic carbon circuit-
breaker, and two 10,000-amp. single-pole solenoid-oper-
ated automatic carbon circuit-breakers, mounted directly
against the left-hand wall; see Fig. 1. The panels for
the control of the direct-current ends are also on this side.
The details of the brush construction of the 20,000-
amp. breaker are shown in Fig. 3. The main brush con-
sists of six unit brushes of laminated copper so spaced
as to secure the benefit of maximum ventilating effect.
Fig. 3. 20,000-Anp. Circuit-Breaker
Auxiliary arc-interrupting contacts are located above the
main brush and on the lower portion of the carbon con-
tacts, which make the final break. Laminated studs are
used for all breakers, and a single solenoid is used for
operating each breaker, regardless of the number of poles,
making possible a very simple and direct-acting operating
mechanism.
The metering and controlling equipment for the alter-
nating- and the direct-current sides of the converters, as
well as for the high-tension side of the step-down trans-
formers, is installed upon the control desk located in the
balcony.
Current for operating the solenoids of the switching
equipment and for the station lighting is provided by a
motor-generator set consisting of a 60-kv.-a., 125-250 volt,
three-phase generator driven by a 500-volt direct-current
motor.
The electrical equipment for the station was manufac-
tured by the YA'estinghouse Electric & Manufacturing Co.
under the direction of William Hoopes, electrical engineer
of the Aluminum Company of America.
POWE B
Vol. 41. No. 23
.jmcoimspiiouio^uis iu©
?s imi
>rs\tt<
By Peter Neff
SYN0PSI8 — You can see -train leaks and smell
ammonia leaks, but yon can neither see nor smell
those heat losses by transmission through the nails
'nfine the heat units. The article suggests
how these leaks mug mean considerable loss in a
short time.
Anyone can see a steam leak or smell an ammonia
leak and know that a loss is s g on, but many are often
unaware of those silent, unnotieeable losses that go on
continually, due to heat transmission, and while these
cannot be entirely prevented, they can and should be
minimized.
A plant may have good cold water and an efficient
ammonia condenser, making it possible tc get the liquid
ammonia away from the condenser at. we will say, a
temperature of 60 deg. Then this ammonia is conveyed
through pipes to a receiver, perhaps located in a hot
engine room, with the result that the ammonia goes to
the feed valve possibly nearer 80 than 60 deg.
W hat do these "JO deg. mean ? Suppose the plant is
of 100 tons' refrigerating capacity and is circulating about
40 lb. of ammonia per minute, these 20 deg. mean about
800 heat units per minute unnecessarily added to the
load. Two hundred heat units per minute is equivalent
to a ton of refrigeration per day. so that this loss amounts
to approximately four tons of refrigeration per day. It
may be argued that this is not much in a 100-ton plant.
But the loss represents money. The greater part might
be saved by spending a few dollars on insulation, at least
covering the receiver.
See that the ammonia leaves the condenser at as near
as possible the temperature of the water available and
that it does not rise in temperature before reaching the
feed valves.
This brings up the question of the use of thermometers
about a refrigerating plant, a subject the writer will take
up at some future time. Suffice it for now to say, one
might as well try to run an electric plant efficiently with-
out voltmeters or ammeters as to attempt to operate a
refrigerating plant without thermometers.
The suction line leading to the compressor is much
neglected; sometimes it bears evidence of an attempt at
insulation, but the last state is often worse than the
first. Most engineers know of the loss due to the exposed
steam piping, but frequently do not apply this knowledge
to the suction line.
To relate an instance of how this matter is sometimes
viewed, the writer found in a plant, a 4-in. ammonia
suction line running partly in close proximity to steam
condensers and thence through the hottest part of the
engine room before reaching the compressor; obviously
this line had been put there intentionally. Upon inquiry,
this statement was given in answer: "You heat the gas
in the compressor, then desirable to heat it as
much as possible beforehand and save work by the ma-
chine."' An hour was spent in a vain attempt to convince
the operator of his error, but he had only pity for me
and my ignorence. Happily, such instances are rare.
Suppose the suction line offers 100 sq.ft. of exposed
surface, and assume a heat transmission of 10 units per
hour per degree difference. It is no uncommon thing to
find the suction line exposed to a room temperature of
80 deg.. while the ammonia gas leaving the place of
evaporation is at zero.
V e may fairly assume an average difference of 60 deg.,
or HO, lino heal units per hour, which is equivalent to five
tons of refrigeration per day. This is not all, for while
the refrigeration load has been increased, the capacity
of the compressor" has been cut down.
It is well known that refrigeration is accomplished
primarily by the heat absorbed in changing the liquid
ammonia into a gas and that this gas is at first in what
is termed a saturated condition where a given volume has
a maximum weight. It is also well known that if this
le heated it will expand and the weight in a given
volume will be reduced. As the compressor offers a con-
stant volume for the reception of the gas, it follows that
the greater the density of the gas, the greater will be
the weight handled by the compressor. So it is obvious
that it is desirable to get the gas to the compressor with-
out superheating it.
We have supposed that superheating of the gas has
taken place, owing to the exposed suction line, so that
in reality there has been an attempt to cool the engine
room or outdoors, wherever the suction line has been run,
which was neither desired nor intended, but which has
required an expenditure of energy that represents a
money Loss.
In the supposed case the 40 lb. of ammonia per minute,
when in the form of a saturated gas at zero degrees, oc-
cupied approximately 367 cu.ft. If, now, this gas is raised
in temperature to only 50 deg.. we find that the gas that
had formerly occupied the space of 36T cu.ft. will now
occupy 416 cu.ft. If the compressor is to handle the
same weight of ammonia, which it must do to produce
the same amount of refrigeration, its speed must be
increased 13} ■_, per cent.
The plant may be, as far as visible observation can
tell, working well, everything apparently in perfect order,
not a leak of steam or ammonia, and yet there may be
some such losses going on.
While, perhaps, the increased number of revolutions
does not, owing to the friction load, increase the horse-
power proportionately, it nearly does so. and almost any
engineer may calculate what this loss means in fuel cost.
The engineer who wants to build up a reputation and
to make himself valuable to the concern which employs
him will, in addition to keeping his plant free from those
defects that are obvious fy- anyone, be on the lookout for
those losses not apparent on the surface. It is this care
that makes some men so much more successful than others.
There are many other losses going on. but the examples
given illustrate the importance of looking into the heat-
transmission losses
June 8, 1915
Teste ©mi ftlh<
POWER
779
b Dis^oimsdl Sthreimg'ltlhj. of
Bonleip Pilate
>>Y ,J. W. P. Macdonald
On Apr. 10 tensile tests were conducted at the Water-
town (Mass.) Arsenal on ^1 specimens of boiler plate.
The object of the tests was to determine the minimum dis-
tance between rows at which the joint fails through the
net section along the line of rivets in one row. rather
than along- the zigzag diagonal lines. The test specimens
| Plate,
^Holes
"'A -
<--w— >
Nos I- 10
Inclusive
A
iPlak,
§Holes
^
B
O*- r.
<5">
Nosll-IS
Incl.
V
jg Plate, ^ Holes
-if- >t« //' w
B
NosJ6-/8
Inclusive
±Plate,Ji Holes
[*— — /£---- -oj
ifi*e"^"^"~2"re"-ii
'■■Si/6
N0S.I9-BI
Inclusive
fig.i fig.2 fig.5 fig.4
Specimens on Which Tests Were Made
were prepared by the International Engineering Works,
Ltd., Framingham, .Mass.. from material furnished by
the Lukens Iron & Steel Co., Coatesville, Penn. Fol-
lowing is the mill test report for the steel used :
Slab No. 9968 G 9968 J 9968 H
Physical properties —
Width, in 1.725
Thickness, in 0.380
Area, sq.in 0.655
Elastic limit —
Lb. per sq.in 36,660
Tensile strength —
Lb. per sq.in 59,680
Elongation —
Per cent, in 8 in 30.0
Reduction in area, per cent 60.3
Chemical properties, per cent. —
Carbon 0.17
Manganese 0.36
Sulphur 0.023
Phosphorus 0.018
The first ten specimens had a section 4 in. wide and
% in. thick between hole centers. The lines through
this section were placed at an angle A (see Fig. 1) to the
line normal to stress, varying from 0 to 90 deg. in 10-deg.
increments. The purpose of this series of ten was to ob-
1.915
0.447
0.856
1.816
0.515
0.935
38,090
36,16
59,340
57,76
28.0
29.5
60.7
57.2
0.17
0.36
0.023
0.018
0.18
0.44
0.030
0.012
varying proportions between the net amount of material
along the diagonal lines and that straight across between
the two holes in the same line. Nos. 11, 12, 13, 14 and
15 (Fig. 2 ) had a 4-in. pitch and represented typical spac-
ing in the inner rows of riveted joints. Nos. 16, 17 and
IS (Fig. ;>) represented the rivet holes in the two outer
rows of the ordinary type of quadruple butt joint with an
outer pitch of 15 inches. In No. 16 there is actually less
material along the diagonal lines between the two outer
rows than there is directly between rivets in the outer
row, a condition given do consideration in the rules for
calculating such joints. Nos. 19, 20 and 21 (Fig. 4)
represented the rivet holes inside the calking edge of the
sawtooth type of quadruple butt joint with an outer pitch
of 12 inches.
Where the same thickness of plate was used, test speci-
mens were all cut from the same slab, in order to have
conditions as uniform as possible. The actual results in
the first ten specimens show remarkable uniformity, par-
ticularly with reference to the elastic limit indicated by
the first scaling of the plate and drop of the beam. The
results of tests made on these specimens follow:
Width
Section
Ultimate Relative
A
(W)
Be-
Elasti.
Strength Ultimate
See
Speci-
tween
Limit
in Lb.
i in
_.b. , Strength
ig. 1)
, men,
Holes,
Pe
Per
Per
Deg.
In.
Sq.in.
Total
Sq.in.
Total
Sq.in.
Cent.
0
7
1.52
62,200
40,900
96,400
63,400
100
10
7
1.56
57,100
:;i;.t;n,i
92,700
59,400
93.6
20
7
1.52
51,100
33,600
87,400
57,500
90.7
30
1.52
45,000
29,600
81,000
53,300
84.0
40
S
1.56
40,500
26,000
78,100
50.100
79.0
50
9
1.56
:::.:
24,000
74,900
48,000
75.7
60
10
1.56
32,800
21,000
71,000
45.500
71.7
70
10
1.56
29,200
18,800
70,500
45,200
71.2
80
11
1.52
27,900
IS, 400
71,900
47,300
74.6
90
11
1.52
26,900
17,700
63,100
41,500
65.5
Curves Nos. 1 and 2 were plotted with the ultimate
strength and elastic limits as ordinates and different
angles as abscissas. These curves show that the ultimate
strength decreased almost uniformly with the increased
angle from direct tension to direct shear.
Specimen No. 11, in which the areas diagonally and
straight across were equal, and No. 16, in which the lat-
ter was slightly greater, failed diagonally through the
three holes, as was expected. Specimen No. 13 was
RESULTS OF TESTS ON SPECIMENS NOS. ll TO 21 INCLUSIVE
Section
, — Normal to Stre
Thick -
Width, ness,
In.
3.06
3.06
3.06
3.06
3.06
14.12
14.12
14.12
11.06
11.06
11.06
0.52
0.52
ii 52
0.52
0.51
0.45
0.44
0.44
0.51
0.51
0.51
Area,
Sq.in.
1.59
1.59
1.59
1.59
1.56
6.35
6.21
Diagonal Sectic
Length, Area
Diagonal
in Per Back Pitch
Cent, of (See Figs. 2-4)
In.
3.06
3.44
3.68
4.08
4.58
13.91
14.83
15.53
1 2 4 5
14.74
16.59
Sq.in.
1.59
1.79
1.91
2.12
2.34
6.26
6.52
6.83
Normal
Section
100
113
120
133
150
98
105
110
113
133
150
In.
1.45
1.75
1.93
2.21
2.54
Elastic
i — Limit in Lb. — *
Total Per Sq.in.
700
2.48
2.99
3.41
44.000
44,200
4S.000
r.ii.iKiii
51,700
204,000
224,000
222,000
27,800
30,200
31,400
83,100
32,600
3G.100
35,700
Ultimate
Strength
, in Lb. v
Total Per Sq.in
91,000 57.200
Efficiency
of Section
, — in Per Cent. — .
Theoret-
ical Actual
28,400
31,400
'< 1.500
96, 1 mi
101,000
98,600
324,600
331,200
325,400
3ns, son
309,400
316,500
59,400
60,600
63,500
63.200
51, '.inn
.-,:;. :'.nn
52,400
54,800
54,900
56,100
76.5
76.5
76.5
76.5
76.5
94.1
94.1
94.1
92.1
92.1
92.1
75.7
78.6
80.2
84.0
S3. 6
81.0
84.6
83.1
87.3
87.5
89.5
tain data for a curve giving the strength of the material
for the different angles. From this curve the propor-
tion of metal necessary along the diagonal lines could be
found directly.
Specimens Nos. 11 to 21 inclusive were arranged with
•Chief draftsman. International Engine
Pramingham, Mass.
ing Works, Ltd.,
stronger than would be indicated from the results found
in the first ten specimens, the ultimate failure being
straight across. With a riveted connection, where the
holes were forced to retain their full width and the metal
was prevented from flowing to the extent it did, as shown
by the elongation of the holes along the line of stress and
their contraction transversely, the results would probably
760
POWER
Vol. 41, No. 23
^
^
£v
jg/-
-•
Kjj
.£/
^v.
--
??s
^
or
?S
?5j£
c •■miT
have agreed more closely with those obtained with the
first ten specimens. Again, in these specimens the ma-
terial wa? given more opportunity to stretch where its
continuity was not wholly broken than if the stress was
transferred from one plate to the other by rivets.
! Xo. 13 was watched with especial interest,
e proportions conformed to those required a- a mini-
mum by the Canadian Rules, and also by the recent A. S.
M. E. Code. Specimens Nos. I \ and 15 broke directly
across, tin- third hole showing less deformation as the
proportion of material inn-eased diagonally.
It would be interesting in the line of further investi-
gating of this condition to have the five specimens 11
to 15 inclusive prepared with exactly the same spacing of
holes, only in the form of a butt joint with double strap,
the double .-hearing strength of rivets being sufficient to
insure a plate failure.
Specimen Xo. lii broke through the three holes at an ul-
65.000
m,ooo
55,000
50,000
'45,000
35,000
30.000
25.000
20,000
15,000
Angle be+ween Line through Holes and Line Normal +o S+ress
Results Obtained with First Tex Specimens
timate load far below the strength according to the meth-
ods of calculation used in the various boiler rules. This
failure shows a rather astonishing condition in the ordi-
nary type of quadruple butt joint. The condition has ap-
parently existed for years without being given much con-
sideration. In designing these joints the practice has been
to find the weakest part by calculating eight possible
methods of failure. Yet. what is the use of such calcula-
tions if the actual method of failure has not been con-
sidered at all? Xo matter if the ultimate strength by
the real method of failure may be only very slightly be-
low the calculated strength, so long as the condition ex-
ists at all, to be consistent a proper investigation should be
made. It is a significant fact that this type of joint is
not recognized by the various Canadian Rules, which we
believe are patterned after the Code of the British Board
of Trade.
Another feature noted in these tests was that in sev-
eral of the samples which failed straight across the elastic
limit indicated by the scaling of the plate was first shown
along the diagonal lines, which under the conditions would
perhaps be the proper criterion for judging the weakest
section.
Another important point to be noted wa that in the
narrow specimens Xos. 12, 13, 14 and 15, with a 4-in.
pitch, the ultimate strength came fully up to that which
might be expected from the mill-test report, but as the
specimens grew wider they fell far below. In specimens
Xos. 19, 20 and 21, the calculated strength as compared
with the solid plate should be 92.1 per cent., but actually
was only 87.3 per cent.. S7.5 per cent, and 89.5 per cent.:
and in specimens Xos. 16, 17 and 18, where the strength
should be 94.1 per cent, of the solid plate, it actually was
only 81.0, S4.6 and 83.1 per cent. These results bear out
exactly the statement made with reference to wide pitches
by James E. Howard in his paper read last December
before the Society of Naval Architects and Marine Engi-
neers.
In this question of the proper back pitch, or distance
between rows, the design should have some excess strength
m favor of the material diagonally and not be merely a
balance. Really, this part of the proportioning of any
joint is a feature of the design preliminary to the proper
calculation by the usual methods. In considering the dif-
ferent possible methods of failure, if no direct calculations
are made for the strength diagonally, the proportions
should be such that there is no possibility of the joint fail-
ing in that manner; or in other words, whatever the
method of failure may be, it should be among those for
which direct calculations are made.
These tests, which will perhaps open the way for further
research along this line, tend to arouse suspicions as to
our high efficiencies. If the 94 per cent, and more of
the strength of the solid plate are not dependable figures,
we may again be falling back on our old friend the "fac-
tor of safety" to make up the difference between actual
and assumed conditions.
S
Plheisisx ©IE suae! Qir^pKite
Quite recently the Richardson-Phenix Co., of Milwau-
kee, Wis., has placed on the market an oil and graphite
lubricator provided with an agitator that continually dis-
charges puffs of air into the oil reservoir. This keeps the
graphite uniformly mixed with the oil and obviates the
trouble usually experienced when attempting to feed
graphite to the cylinders of steam-using equipment. Re-
ferring to the accompanying illustration, the lever operat-
ing the lubricator is given a reciprocating motion from
some external source such as the valve gear of the engine.
By means of a ratchet which has four go-ahead and two
retaining pawls, the lever arm causes shaft A to revolve
in one direction, rotating the cam and causing the yoke
to reciprocate vertically for each feed.
Upon the upper stroke of piston B the oil and graphite
mixture is drawn into cylinder 21. On the downward
stroke of the piston the mixture is forced up through
the check valve 0 and tube D, thence down through the
opening F and the sight-feed glass to chamber G. From
the bottom of the chamber the mixture is drawn up past
check valve II by the downward stroke of the piston /. On
its upward stroke the piston forces the mixture through
check valve J, out into the feed line to the terminal
check valve. In the illustration a section through the agi-
tator nozzle is shown, but the oil and graphite feed is ex-
actly the same. The terminal check valve is inserted in
the steam pipe above the throttle or into the steam-inlet
passage to the valve, and the incoming steam picks up the
graphite and oil from the -atomizer nozzle.
To fill the lubricator, oil is poured into strainer K.
The quantity of oil and graphite fed for each stroke of
the pump B is regulated by means of an adjusting nut L.
To the lower end of the adjusting rod is attached a metal
strip carrying the cylinder .V. Turning the nut in a right-
June 8, 1915
POWER
781
hand direction lowers the rod and sleeve so that on its
downward stroke the plunger B does not go to the end of
the cylinder. Thus, a portion of the oil remains in the
cylinder and only a small quantity is forced up through
the sight-feed. Turning the nut in the opposite direction
raises the sleeve to its highest point and increases the feed
to the maximum.
To keep the oil warm when the lubricator is used in
cold places, a cored opening N has been provided, so that a
Section through Oil and Graphite Cylinder
Lubricator
steam line can be connected if desired. A gage-glass shows
the level of the mixture in the reservoir, and as some kinds
of graphite are liable to form a deposit on the glass, a
float-operated indicator is also provided. This consists
of a rod 0 operated by a float P.
The agitator unit is exactly the same as the mixture
feeding pump except that only enough of the mixture is
pumped by the lower plunger B to provide a seal for the
top plunger I which handles air drawn in through a vent
in the top cover of the sight-feed glass. The air is com-
pressed beneath the check valve R to a pressure of about
300 lb.; when the resistance of the spring is overcome,
the air is discharged with a puff through pipe 8 to the
bottom of the oil tank. These frequent discharges keep
the graphite uniformly distributed throughout the oil.
A three-way cock T is inserted over the check valve, so that
it may be determined whether or not the agitator is work-
ing properly.
By turning the handle to the horizontal position a by-
pass to atmosphere is opened, so that the discharge can
be observed and the air pressure tested. On the agitator
feeds the top of the adjusting rod E is slotted and the
thumb-nut eliminated. The rod may be turned by a screw-
driver and when the proper adjustment has been obtained,
it is held in place by a locknut.
Hofwegiaa Ws\tterfai]ll C©iaces<=
At a cabinet council in Christiania, on Apr. 16, it was
decided to bring in a bill to restrict further the existing
laws of 1909 and 1911 in respect to waterfall concessions
in Norway. The right of the state to regulate water-
sheds is confirmed in principle. Where public conven-
ience is not interfered with and the regulated power does
not exceed 500 hp. and is distant 12i/2 miles from an-
other fall, no concession is necessary. Concessions will,
as at present, be granted by the King, though with the
proviso that where the regulated power exceeds 10,000
hp., or where considerable interests are involved, the
terms of the concession must be submitted to the Stor-
thing (parliament) for discussion. The existing maxi-
mum period of 80 years for a concession is reduced to
60 years, though in special cases, and with the sanction
of the Storthing, it can be extended to 70 years.
The present clause giving to Norwegian citizens and
Norwegian joint-stock companies an unlimited period of
concession is struck out, but is maintained in respect
of Norwegian communes. At the termination of the
concessional period the state can demand the transfer to
it of the undertaking, with its lands, buildings, etc.,
without any compensation whatever. As regards con-
cessions for a shorter period than 50 years, an amount
can be fixed for the redemption by the state of the whole
or a portion of the constructional work, based on the
original cost of the lands, buildings and plant, according
to its technical value, less amortization.
At the end of 40 years from the date of the conces-
sion the state is entitled to take over the entire proposi-
tion at its original construction cost and the plant at its
technical value. This right may, if it be more conven-
ient to the state, be postponed to periods of 10 years
subsequent to the 40 years mentioned.
An important provision is an increase in the maximum
royalty to the state per horsepower from 26c., as at
present, to 52c, plus 26c. to the commune, or 78c. in
all ; though in special cases the total to state and com-
mune can be increased to $1.04 per horsepower. There
are, moreover, obligatory clauses relating to the supply
to the state and commune of power at fixed prices and
the use for the public of bridges and roads constructed
by the party receiving the concession.
The proposed bill, the drastic restrictions of which are
directed against foreign exploitation, is viewed with
much disfavor by the progressive element in Norway.
It is feared that its provisions with wages at the contin-
ental level, the 8-hour a day pending, and taxes at the
breaking point will do away with the notion abroad that
Norwegian waterpower is cheap.
?82
POWER
Vol. 41, No. 23
<r7i^
0)
[M.
^jw ^.4v?j!?r>: ^v^if *e=s a^?!?? £*
!J • ! i 1
j si Ij I -1 "i 1
1 i U & ItU i i i
! 1 :1 J! !j !i l \ i
i is] 1 1 1 1 1 1 j i |
1 i ~ \ 1 1 ! i ! -1 : 1 \ \
i i ;j ;? f ; f | ;j| 5
j I I»j 1: •! !l Il| \
1 ' ill i] ■: \l s « : :
I 1 |!i II || |] I IJ 1
» f ^ 1 1 1 II 11 is %il i
u £ 5 1 Ji *» >i 5; siS ;
IH
a*** aw* *fw *«__* 2222 ***£ *£££ ££££ «««
ii'i
M" ■"»■<* ■* *(D(D<D CD CD CM CM CM CM (D(D 0001 ***ff> (DODO CD CM CM COCO (OOO
-_ ___,^ CMCMCMCM CMCMCMCM CMCMCMCM OOOO O**
III
bb^tio ibtbr-r- <bo>o^- o^bs- o-«V ko>«V ^co^-r) combcM loF-b
— — — -,-- CMCMCMCM (MCMOO OO^'f **lOIO I0»(0
; J
_ __ _ - -cm cmcmcmcm cm cm cm cm cmooo nnor) ooti
f
2
VtOCob S-boiO O — CM* lobs-b oVbcO OOCOb OObl-- OCmVi- b — IO
- ---- ---cm cmcmcmcm onoo ***** wioioio ioco(o
u
i °
cm coo>o
o oo*
</> : z
o ooo
J-S
o oo*
il-i
3 r-o*
o o**
i5ii
o> bow
z
a
O
1-
<
z
<
i i ill ii lii! Ui I
si *
r- too — o *io<dcd oio-o t«"-
— — CMCMCM CMCMCMCM cmooo OOO
j f f || j; ill ]]
° ; ■*
* ibbf-cn atbboi bbiob br-cn
l|s 5 3 = : : : : : = = = ; : :
x 1 i 5jf Hi ill >i
f i -: : ! ' ill hi s>
' 15 «*! M! 5il -1 ■
!! !? illi 111 iM ?i if
If iHHt'iilfi it S1
>{l* lilt lii i!l 111!!!
": -1 |l = ^ lit 111 ''til? :
CM *lO(0C0 COOOCM **C0CD ID O CM
— — — -- -CMCMCM CMCMCMCM CMOO
I (J
<obh- F-CDOO — — CM* (Ol-COO) ocm*<o coocm* cocdocm *cocd
«- — — — — «-*-*-*. CMCMCMCM CMOOO OfO^I * ^ *
DC
CMCMCMCM CMOOO 00** lOlflbcO bb?-<D BOO
u
bKcbcn o»-cmo Vtos-O) bcM*r- — o*s- bof-
,-—-»- -.--.- CMCMCMCM OOOO ***
Q
bo> — ^- o*bb cob — o br-bb s-bcub oos.
-— — __,- — V-CMCM CMCMCMO OO** * 10 10
O
CMCMCMO 00** *lob<0 (Obf-CD bfflbo b«-CMO *10«N ODCftO*- CMO'-t
-- ^^^^ »-— -^ --CM CM CMCMCM
m
inbtDCD skcdo) bo — cm vvyho) — cWb o)-^*b cn-^tb o — ^b o> — **
— ^— ^^^.^ CMCMCMCM CMOOO OM^M* ^lOlOlO lOCDtO
4
M^^tVio bcobf- r-tobcft oo — o lobbco bbw^ cof-cDb WM'br-- oocm
j
- — -CM CMOOM^ VlOCOK CDCDOCM ^lOtDCO OCM'*© (DOCM^ (OCDOCM M'CDCD
lii
^^/■^^ =~".v^ ,^?.^f ^^ .< ^-.^^^ *Sa? ^r'.^f ri#
w ww«w cycycMcg cmwcmoj hnnh hhhh hhhhh
lii
^-?-£-» ~5^^5-5 -S-5~3~? -5-S-5-^ -5 -S-S-?-S ^-!~--^ -*-•-•-• -?-•-•-* -?~S~?^ -S-S-^S ~?-^-?^ -* ~9 -«~?~?^-S
1 ill
'f'J'J^ TfTj^CD CDCDCDCD CDtNOJCM CM (D CO b OOOt CDCDCOCM CN OJ U? U? OO't'J V^CDCD CMCMCMCM C0C0OO OOOO ^''jeDCD CDCOtDCDCO
!»
obb< booh-r- r^bbo — brtr- a>o — cm tor-b— ^cobb cMbr-b -bcob bcMin?- b — ^co bbcaV ba> — b bi--ocM Vbbow
— -.^ — — — WCMCM CMCMCMO OOO^ ^^^^ lOlOlOlO (OcOCOCO (ONr^h- f-COOOCO CDCOCDO 010)00 OOO —
. )>
^^^s? ?&? f ?? ^ A^i« iftft^ ??£ ^^ ^S?:^ s?^
rg cjoora nono nonn nono o^t^-* *^**'*
lj£ !
^ViocO r^F-bot bo — cm biocoo) — cmoio f-bcM't bb — o coboo br^b— *tbco— oidcdo cM^tbb oob^- o>c\iVb to— bbr*-
0) °
?- b — ^tco OCM
CM CMOOO -^■'t
Ei*
- -" " O OO
iis
U) r-b — io r-0)
CM CMCMOO OO
if J
<0 <DO)CMIO SO)
CM CMCMOO OO
3" -.>
0) OOCMCM tlD
-j = s:
10 S-CDOJO — 0^-10 CDCDOlO — O^lO CDr-OO — CM^lO CDh-COO) OCMO^t CDS-CD— CMO'tiO^
- —--CM CMCMCMCM CMCMCMO OOOO 000-$ -$■■»■■<*-<* t^f* mmmm lOiOtOlO CO 10 CD 10 10
2= -j
o ■"t'jinio cdcdcoo) oocmo o*fiocD r-oai— nonm mr~oo cvnryt r-r-coo ownow
i- ij
cm ■$ m co cd cdoocm '♦^tbb bocMCM ^jbbb bbcM-tt »tcobco ocmcm^ bbbb bcM^^tb
- ---- -CMCMCM CMCMCMrg otnnn nnnn -tw-? -?$$$ mmmin inuiioco toiotocoio
1°
tc
CDCDh- SCDCflO — — CM^" <0S-CDO> O CM ■* CD CD O CM ^ CO CD O (M t CO CD O CM $■ CD CD O CM ■* CD €DOCM^ CO CD O CM *J CO CO O CM'tCOODO
<
a u.
z
--CMCM cmooo obb1* V'jmb (ooobh- obooi bo
R «-
Ibbh-co bo-cM cibVb NbbV s-bocj ios-b^ bc»
Q
s-<D0)O cMO<no ios-coo cm-^ioo o^cdo* ocoeno <do
O
— cmcmcm oob^ <Vtob btobF- r-cooob bo — o ^iocds- cdojo— cyo^to cos-oo) o — cmo ^iocos- cooo— cmo^io cds-cdoo
m
iflbcob sscoo) bb — cm ^bbo) — ca^b O) — 3b o> — ^b o> — ^b o'^-^h ai~t& o>~*<d o> — ■*«> at^-itfo o> — ^b o* — ^bo>
4
ciO'fV iob(ob s-r-cob 0)o--cm ^-Viob odocmo ^tiooos- odoo- cmom*u> h-o — cm <rios-a> 0 — 0^ cococho cmoios coo) — 0^
=
-- — CM CMOO* ^tOOh- (DOOCM * «0 (D CD O CM * CO CD O CM * (OODOtM *J tO CD O CM f (0 CD OCM^CD CD O CM t CDCDOCM ^COCDO CM ^ tO CD O
~~ ~ — ~w CMCMCMCM CMOOO OfJ^t * * * 10 10101010 «>(D<D(D IDSNS r-NCDCD (DCDCD0) 0>0) 0)0)0
IS**-
.2 g -" Z
d - ?
- c fe
^3 rf O o
m o tJ
8"* 3
June 8, 1915
siiHiiiimiiimiiiiwiiiiiiiii
POWER 783
ii iiiiiiiiiiiiiiiiiiiniiiiiimii ii iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiuiiiiiiui uiiiiiiiiiiiiii ii uiiiiiiiiiinuuiuiuiiiiiiuiiiiiiiiig'
^dUtoffmls
<ClsiSs5iScsiftaoini ©if Tedhimicall
On another page is reported the organization by some
twenty national technical and scientific societies of a
Joint Committee on Classification of Technical Literature.
As its name indicates, its purpose is to propose a standard
method of classifying technical literature so that filing
may be facilitated and the valuable things which are
being forgotten and practically buried in the back
numbers of periodicals or other sources of information
may be kept easily available.
The problem before this committee is three-fold. First,
to arrange a complete classification of subjects in the
wide fields of technology and applied science. Second,
to select or develop a notation or system of indexing for
the subjects classified. Third, to set before the publish-
ers of technical journals and books, and societies that
print technical and scientific transactions and proceedings,
the value of adopting the accepted classification and nota-
tion.
From the deliberations of this committee will un-
doubtedly come suggestions as to ways in which the papers
can cooperate. It goes without saying that Power will
be glad to do its part in any such way, and undoubtedly
all others will be similarly disposed, for it will be to
their interest to have the value of their issues made more
enduring.
Power is not insensible either of the honor of having
its editor chosen as the first chairman of the committee.
Side ILa^lh£§ ®im
To many engineers, service in a hydro-electric gener-
ating station means almost exile. They dread the prospect
of spending years in a plant situated, as they often are,
many miles from a city, in a rough or mountainous
district. Others see in it opportunities for maintaining
a little country home and a pocket-sized farm as a "side
line," but fear that the work itself will lack interest
because of the absence of steam equipment, the few men
required to handle the installation in normal service, and
the apparent simplicity of the operating routine. They
feel that the opportunity to grow may be denied the
water-power plant operator — that a job of this kind may
be good enough for an elderly man who fancies solitude
and enjoys grubbing in a garden and counting eggs, but
that it cannot appeal much to an engineer with real "pep"'
in his makeup.
For some men this point of view is so ingrained that
it would unquestionably be a false move to accept a
position in a station of this kind. It is, no doubt, partly
a matter of taste whether an engineer will find satis-
faction in a steam plant in the town or in a water-power
station many miles from the allurements of city life.
But, granted the importance of applying the personal
equation to hydro-electric plant service in remote
localities, it is worth realizing that this kind of work
may possess both interest and opportunity if a man takes
advantage of his chances. The casual visitor to a hydro-
electric plant in the wilderness goes away with the
impression that there is comparatively little apart from
routine work for the operating staff to do. It seems to
the layman merely a question of opening the gates and
letting the water run through, and the wheels do the rest.
Beyond oiling the governors, keeping an eye on the
lubrication of main-unit and exciter bearings, putting
down the half-hourly instrument readings on the log
sheet and watching out for possible damage from thunder
storms, life appears to be one glad, sweet song. Wages
are moderate, to be sure, but the little farm does the
rest, thinks the visitor, and seldom does anything arise
to disturb the poise of the operating shifts.
Brethren of the water-power service know better. They
appreciate that under normal conditions, with everything
running smoothly, the days sometimes do seem a bit
long, but the wise ones in this work find fully as much
to learn as do their steam-plant brothers in the town.
It is true that the design of a hydro-electric station
generally "stays put" and that capital errors in layout
can be corrected only at relatively high cost. In its
general arrangements such a plant is a pretty rigid affair,
but this does not mean that skill is not necessary to
operate it efficiently. Waterwheels and generators have
their economical range of output no less than steam-
driven machines, and conservation of storage facilities
is as important in many plants as the careful use of fuel
in steam stations. The relations of weather conditions
to stream flow, the changes in effective head on the
wheels, accuracy with which the governing equipment
operates, effect of wear in turbine blades and passages
upon water consumption, prevention of ice formation
within wheels, proper handling of sluice gates, and the
study of voltage regulation — all challenge the interest
of the engineer of inquiring mind. The opportunity for
the installation of home-made apparatus in the auxiliary
branches of water-power plant service is large, notably
in connection with the remote control of head-gates, the
prevention of leakage, recording of river, reservoir and
tail-race elevations, economical repairs, and improved
lighting and small power applications. When a hydro-
electric plant operates in parallel with one or more other
stations, the possibilities of utilizing water efficiently
become even more interesting and important. The re-
duction of waste has not received the attention it should
in some stations, while in others it has gone to such
refinements as the installation of special meters for water-
flow records, the subdivision of local lighting and power
circuits, the inclosure of operators' quarters in electrical-
ly heated spaces of limited size, use of the more efficient
types of lamps, and recirculation of transformer cooling
water.
In emergencies the operator's skill is taxed to maintain
continuous service, no less than in steam stations. The
isolation of line troubles is almost a specialty in itself.
;S4
? 0 W E R
Vol. 41, No. 23
The man with a leaning toward investigation will find
plenty t<> occupy himself with if he confines his attention
lor a time to the good points and shortcomings of alter-
nating-current relays in relation to trouble detection and
segregation on the system at large. The study of light-
ning protection is another big subject, worthy of unusual
ability, and we repeat the profound interest always
associated with the subject of waterwheel governors. As
a factor in securing an all-round experience in powi i
production, the water-driven station will he in the run-
ning for a long time to come. Its isolation but gives
the keen student of this branch of engineering better
opportunity to master this part of his profession. Pew
indeed are the cases where the mails will not bring the
benefits of the technical press just as well as in the city.
The laws of power production are universal in scope,
and if the operator refuses to yield to the temptation to
live a routine life and sticks to his purpose to become an
expert on the work with which he is engaged, location
becomes of secondary concern for the time being and
opportunity absorbs him to a degree but little realized by
the fellow who thinks that water-power service is narrow-
ins to ambition.
stgift© i%i€>ls filsisusas I^EagaE&eeirs
The commendably generous offer made by the Kansas
State Agricultural College to assist in the educational
program of the National Association of Stationary En-
gineers of that state will most likely be accepted. State
and municipal educational institutions of an engineer-
ing or technical character might well consider following
Kansas' lead.
The college offers to direct a course of study under the
auspices of the State association, each subordinate asso-
ciation to have at least three lectures a season by a repre-
sentative of the college. Special lectures on subjects
allied with power-plant operation will also be given. The
college aims to send out questions and references to each
association. Every sixth lesson will be in the nature of
an examination, the results of which -will be reported to
the college. The associations are expected to pay for
only the traveling expenses of the lecturers; this outlay
tu lie met by special assessment. It is the intention to
begin the course July first.
The National Educational Committee of the associa-
tion supports a program similar to that offered by the
Kansas Agricultural College. It would seem that both
programs could be carried out to the advantage of all
concerned.
Plaints
To the mind of the layman cleanliness implies absence
of dirt. To the engineer it means, or should mean, ab-
sence of anything foreign to the machine or apparatus
or its functioning. As someone has said, "Dirt is matter
out of place."
The refrigeration plant is a place of transmissions.
Not the noisy, evident processes heard and seen in
turbine or engine rooms or in shaft alleys or belt races,
but the quiet, invisible transmission of heat through
metal walls. You cannot see it. Sometimes in some
places the hand, sensitive as it is to temperature differ-
ences, cannot inform even approximately how effectively
this transmission, which is so vitally necessary to the
plant's efficiency, is going on.
Elaborate, extensive and expensive tests have been con-
ducted tn reduce to accurate figures the losses due to
scale in boilers, because scale is an undesirable insulator
between heat and the water that should absorb it —
because it is dirt; because it is foreign.
The refrigeration plant is a great rendezvous of similar
foreign substance or substances having similar effects. If
the condensers are scaled the heat-laden ammonia cannot
get rid of its heat as it should, and it starts on its heat-
absorbing journey handicapped and partly incapacitated.
If this were all it would not be so bad; but when this
ammonia arrives at the working place, at the cooler and
the coils, the same coils may be so insulated with ice or
scale, or both — and both are foreign, both may be con-
sidered dirt, because they are matter in the wrong place —
that the half-able ammonia cannot even do what it is
willing to do. The compressor water-jackets, the
absorber, the generator, the precooler, the cooling tower —
all may be likewise coated with dirt. Even the noncon-
densible gases may be considered as dirt and are worse
than scale or ice, because they circulate.
The whole system must be as clean as a freshly
laundered shirt if it is to work well. How to keep it
clean and working well is the engineer's job. He is
the laundryman as well as the maker of the shirt, which
in this case happens to be refrigeration. The articles
now appearing in Powee tell him in that good old shop-
talk way how to do it best. They are useful articles, these ;
and we hope to have more of them.
Engineers in charge of industrial power plants are
more and more being made responsible for the quality
of motor service rendered on the premises. Even where
the establishment carries one or two electricians on
its payroll, the chief engineer is likely to be blamed for
motor troubles, and the anticipation and prevention of
these deserve some attention. Motors of the induction
type, if built by reputable concerns, will stand a large
amount of abuse, it is true, but the furnishing of efficient
service is today demanded almost as much as regular
operation, and superficial knowledge of what the local
motors are doing is a pitfall into which the steam engi-
neer in executive charge of this branch of the installation
should not allow himself to fall.
The larger the plant, the more justifiable it is to keep
accurate records of the repair items on individual ma-
chines, the performance of different makes, any tendencies
toward heating of bearings or moving parts, and the re-
peated need of adjustment of air-gap conditions, align-
ment of bearings, or commutator difficulties, where direct-
current motors are used. The value of card-index test
records of loads carried has been emphasized in these col-
umns ; of equal importance is the maintenance of a high
power factor in alternating-current installations. Pro-
tracted underloading of individual motors leads to over-
heating of generators from excessive idle current, and
the study of manual versus solenoid control for motors
on machine tools is one of lar°;e interest.
June 8, 1915
POWER 785
mi 'limn iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiii i iiiiiiiiiiuiiiiiniiiiiiiiiiiii mi . iiiiiiiiiiijiiiiniiiiiiiiiiiii ie
©rrespoimdleinice
Depftlh ©ff Sft^aHiLffiig|=B©s£
The writer has had the same trouble with an outside-
packed pump as described by C. E. Sherman in the issue
of Apr. G, 1915, page 481. In my case it was overcome
by fitting a dummy packing of lignum-vitae two inches
leep and filling the stuffing-box with soft packing. This
means of packing removed all trouble and considerably
reduced the friction losses.
For low pressures white-metal shavings, with a turn
of soft packing before and after, will give good results.
E. E. Pearce.
Rochdale, England.
&
Is©fflra<efor£<e Dirawiimgls
Most power-plant engineers can make pencil sketches
of the general appearance of parts of machinery, showing
the dimensions and thus conveying the desired informa-
tion to others. Most men would probably draw freehand
two or three views on the back of a report sheet and
write in such information as they thought the drawing
failed to give. A sketch in isometric perspective, or sort
of a bird's-eye view, necessitates but one view and is easy
to make, yet engineers generally think it beyond their
%Tap
-
Fig. 1. Fig. 2.
Advantages of Isometric Sketches
ability. Such a sketch shows the parts in their true re-
lation best and is really easier to draw.
In a number of cases repair parts made from drawings
capable of being misinterpreted have resulted in expensive
mistakes. One instance will illustrate. A Corliss engine
broke one of the bell cranks. The engineer took the gear
apart and sent a helper in with a sketch of the broken
piece, Fig. 1. I could see that he had laid the broken
crank on the paper and drawn a line around it, and then
put on such dimensions and notes as he thought were nec-
essary. The hub was shown dotted and there was a chance
for a misunderstanding as to which side the hub should be
on, so I phoned to him for the old casting. For some rea-
son he refused to part with it and told me to make it "just
as it says on that paper— and be quick about it," for he
had to start up at 6 : 30 o'clock.
It was forged out, finished and delivered after working
hours. Next morning there was a phone call for another
crank made with the hub on the other side, "where it be-
longs." The second crank was made as shown in Fig. 2,
but there was trouble when the bill for two cranks was
presented. Fortunately, we had retained the engineer's
drawing and the first crank.
The bill was not paid until a competent person had
passed on the correctness of the work. Of course, the
intentions were all right, but the mistake was in showing
the hub by dotted lines, indicating a lower or invisible sur-
face according to the rules of drawing. The engineer
had not known this and had committed the error.
A little time spent in practice will make anyone fairly
proficient in sketching. It is interesting and is helpful
even when correct three-view drawings are at hand.
Donald A. Hampson.
Middletown, N. Y.
5S
Cleaim Mew Sttesiinm ILiimes
Although steam has been used commercially for one
hundred years or more and steam regulating and economiz-
ing devices have been constantly increasing, many engi-
neers are still ignorant as to certain vital points. The
greatest trouble we find is that a large percentage of engi-
neers (and this refers to the educated men as well as the
ones in overalls) will connect up an entirely new line and
blow dirt, grease, white lead, red lead, iron turnings and
dirt generally through separators, reducing valves and
steam traps and all other devices.
Cannot you start a campaign of education along these
lines ? We advise wherever we have an opportunity to do
so that the lines be blown through for at least forty-eight
hours before connecting up the devices. Of course this
wastes a lot of steam, but it is paid for a hundred times
over in the avoidance of subsequent trouble.
E. E. Strong, Pres.,
The Strong, Carlisle & Hammond Co.
Cleveland, Ohio.
©sioims asa ]fl>©nil@s*
I have read the discussion on this subject for the rea-
son, chiefly, that we have had similar trouble, although
so far no damage has been done. Mr. De Blois in the Apr.
30 issue states that his boilers are equipped with under-
feed stokers. [These are of the Jones type. — Editor.]
We have four boilers, horizontal water-tube, equipped
with underfeed stokers (Taylor), and on several occasions
there have been explosions which occurred while the fire
was being worked. I have studied the conditions and be-
lieve the trouble is caused in the following manner:
The arrangement of this furnace is such that the coal
is pushed into a trough, or retort, by the slow-moving
plungers. It is then worked forward and upward by the
plunger and incoming coal. When the coal first enters
the retort it is fine and closely packed and sometimes
•See "Power," Apr. 30, p. 553; May 11, pp. 651. 652 and 653,
and May 25, p. 719.
786
F 0 \Y E i:
Vol. 41, No. 23
quite damp, as we wet the coal in the bunker to keep the
dust down.
The air holes in the tuyeres are above this trough and
about at the level where coking takes place as the coal is
moved forward in the furnace. With ordinary crushed
bituminous coal, usually quite line, the greater part of
the volatile hydrocarbons are driven off at about this point
in the furnace and pass through the incandescent fuel
bed above to the combustion chamber. After a few
hours' firing a clinker will form on the tuyere plates,
which partly obstructs the air passages through the tuyeres
and which must be broken up and removed with the slice-
bar. This is done through the small side doors. Some-
times it can be done without disturbing the green coal be-
low the tuyeres, and at these times there have been no
explosions. But at other times the upper part of the fire,
or the incandescent fuel bed, is so broken or so light after
getting the clinkers out that it is necessary to break the
lied of green coal to level the fire. This liberates a large
quantity of rich gas which is below the level of the air
openings ami has not a good chance to mix with the air
coming through the tuyere holes. As this gas rises it
comes directly across the path of the high-velocity incom-
ing air and forms a large volume of gas that is explosive
and does explode when ignited by the incandescent coke
and hot side walls of the furnace. In some cases the
flames, usually accompanied by a shower of sparks which I
think are particles of coal dust that have been ignited, have
shot out of the small doors and into the fireman's face.
When the fresh coal was quite wet this explosion was some-
times strong enough to blow open the side doors. The
reason that wet fuel causes a more violent explosion is, I
think, because the coal is packed more closely and does
not allow the gas to escape readily until the fuel is broken
up with the liar.
The air pressure in the wind-box at the time these ex-
plosions occur is usually about 1.8 to 2.5 in. of water.
The boiler damper is usually wide open, and the draft
over the fire is maintained at about 0.2 to 0.3 in. of water
in the front pass.
Mr. De Blois asks for suggestions as to how to prevent
these explosions. I do not know how his furnace is con-
structed or how the fan is controlled, but in our case the
speed of the fan engine, which also drives the stokers, is
controlled by a damper regulator which, instead of be-
ing connected to the dampers, is connected to a butter-
fly valve in the steam line to the engine. When the
pressure drops about 1 lb. the engine speeds up to about
450 r.p.m. This creates considerable air pressure in
the tuyeres, as the steam pressure is usually a little low
at this time, and when the green coal is moved with the
slice-bar a large volume of explosive gas is liberated.
As a remedy for this trouble I would suggest two
changes in the operation, either of which will bring about
similar results. First, before the fires are worked with the
bar in cleaning or leveling, close the gate in the air-supply
pipes, which the fireman will probably not do unless spe-
cially instructed. Second, change the methods of con-
trol of the fan so that the air pressure will lie constant
and will change only as the load changes, or in other
words, make the air pressure proportional to the load car-
ried by the boilers. The first change will prevent suffi-
cient air from entering the furnace at the time when
the rich gas is being driven off to cause an explosion, the
gas escaping to the stack. The doors are so small that
only a small volume of air can enter at this point, and
the air that can filter in through the setting at this low
draft pressure is negligible so far as explosions are con-
cerned. The second change would give an even air pres-
sure at all times and might prevent a proper mixture of
explosive gas. It also has the advantage of giving a
uniform rate of combustion with only the minimum
amount of excess air, a condition which makes for
economy.
I have never known an explosion to occur except when
the front doors were open, but this is the time when the
coal is being disturbed, and the air probably comes through
the tuyeres instead of through these doors.
J. C. Hawkins.
Hyattsville, Md.
&
§ tha ffi im g| ° B <o> 3K
After having a great deal of trouble with the packing
on one of my engine rods, I overcame it as follows :
Stuffixg-Box Bushed
The rod was 2 in. and the packing % in., which is too
large for a rod of that size, so I made a bushing l/j. in.
thick and drove it into the stuffing-box, as at B, turned
i'T, in. off the gland at .i and used %-in. packing, which
works to perfection. This engine makes a 60-day run
of 24 hours without a stop, with a piston speed of 400
ft. There has been no trouble with the packing during the
last 45 days.
M. J. Meeeell.
St. Louis, Ho.
'0.
Griroua&ainig? •iminidles" Heavy
With small engines — those weighing six or seven tons —
six wedges. 2 in. wide, ,s in. long and y± in. thick at
the point by % in. at the butt, are quite sufficient if
distributed one at each corner and one in the middle of
the frame at each side and all removed as soon as the
grout has set. When the engine has been leveled up with
a %-in. space left for grouting, a dam of clay or mortar
should be built around tne bed so as to let the grout
stand two inches up the side of the bed. The grout
should be two parts clean, sharp sand and one of cement,
•See previous discussion. Mar. 2, p. 310; Apr. 6. p. 4S2; Slav
4, p. 620.
June 8, 1915
i»o w e i:
787
mixed to the consistency of thick buttermilk and run
in (the bolt holes having first been surrounded with
,l.-i\ ). Mr. Wilson speaks of borings and ammonia; this
is all right Eor small jobs, but hardly feasible with a big
machine.
The old-fashioned way of bedding down to a stone bed
was good, as the stones were very little affected by oil,
whereas many foundations have been ruined by oil getting
between the bed and engine.
Care should be taken to remove all traces of oil be-
fore pouring the grout and it should not be allowed to se1
too quickly. This may be retarded in a hot room by
covering the exposed parts with burlap which should he
kept wet. Always make sure that there is a free es-
cape for the air from the inside of the box beds, other-
wise the grout will nut flow evenly tu all parts.
E. R. Pearce.
Rochdale, England.
In the issue of Apr. 4. p. 620, .1. E. Poche advocates
using iron wedges in leveling up machinery preparatory
to grouting in. Wedges of this kind serve very well for
leveling up, hut should not lie left in as he recommends,
as the base of the machine will rest on the wedges and
not on the concrete. We tried it once and had to dig
the grouting out and do the job over, because of the
engine sliding on the iron wedges. I prefer wedges of
hardwood for this work.
J. 0. Benekiel.
Anderson, Ind.
? mm ©warms
\©adl@
The cooling water, which contained a large amount of
sulphate of lime, for an air compressor ( 12 'jx 181/^x12
in.), had been throttled, and it raised the temperature of
Inlet
Out lei
Acid Piped into Water Jacket to Remove Scale
water so that it deposited inside of the cylinder jacket a
hard scale which we could not get at to remove with tools.
1 used muriatic acid piped through as shown in the il-
lustration, and it worked fine. It took ten gallons at 60c.
per gallon to do the .job.
To operate, close the lower valve and fdl the reservoir
with acid, then close the upper anil open the lower valve.
The acid forces it^ way through and disintegrates the scale
in the jacket. I used the acid over again as long as it
had any strength.
W. A. Hendry.
Grinnell, Iowa.
V
O^atees5 Ac<ta©im lira si Wattes3
I hesitate to tell the following experience with a 72 ft.
by 1? ft. (i in. horizontal return-tubular boiler, for I
would not believe it myself until I had actually seen it.
The boiler had been out of service for a few days for
cleaning and repairs. When it was ready again the
Water Column as Connected
fireman replaced the manheads and started to fill it with
water. (It has been the custom at this plant when till-
ing a boiler to leave all connection closed till an air
pressure of about 20 or 30 pounds has been reached;
then, if either manhead gasket is defective it will show
it at this pressure and can be changed without having
to pull the fire.) When the fireman returned to this
boiler he found the water showing at the top of the water-
glass. He immediately shut oft' the water-feed valve
and opened the blowoff to drain out the water to the
proper level for firing up. But he had no sooner opened
the blowoff valve than the water disappeared in the
gage-glass and did not return. He then closed the blow-
off and opened the feed-water valve, and the water
immediately rose to the top of the glass again. He
repeated this performance several times, with the same
result each time, and then called in the foreman who
also obtained the same results. He then shut both the
blowoff and the feed valves and opened valve C (valves
A and B being already open), and there was a strong-
suction of air into the boiler. Valve B was next closed,
with valves .1 and C open, and water rushed out with
considerable force. Valve A was then closed, with /.'
and 0 open, and the water immediately stopped running.
I, ut there was no suction. On opening valve A. however,
with valves />' and (' open, the suction commenced again
and the water could be seen rushing upward through the
gage-glass.
These valve changes were made many times, with the
same results. With valves .1 and B open and C closed,
the water sometimes showed at one height in the glass
am1 sometimes at another. It finally came to rest a1 a
>.s
TO WEE
Vol. 41, No. 23
point a little below the third gage-cock, but the suction
continued when valves A. B and C were opened, and wa-
ter rushed out when valve B was closed, with A and C
open, as before.
It was finally decided to take out the rear manhead to
see the actual location of the water level. Before doing
this, however, valves A, B and 0 were again opened
and the suction was as strong as ever. Valve C was
i losed and the water level, after some fluctuation, came
to rest in the glass a little below the third gage-cock.
The rear manhead was then loosened, but instead of
falling in as was expected, there seemed to be a heavy
pressure holding it in place. It required several sharp
blows with a heavy bar to loosen the head. When it
was finally driven in air and water spurted out as if
from heavy pressure. The water level was found to
be about a.- the level in the glass had last shown it.
The boiler was then emptied and all the pipe con-
nections of the water column removed and examined.
The lower horizontal pipe marked F was partly closed
with scale, but still had a free opening of ample area,
and the rest of the pipe and the water column itself
were perfectly clear.
Now. if anyone can satisfactorily explain how vacuum
and pressure can exist in the same boiler at the same
time I would like to see the explanation published in
Power. Also, why and how did the water siphon out
of the boiler in a continuous stream when valve B was
closed with A and 0 open ? Pipe G did not extend
through the shell of the boiler more than y2 in., and
the water level was eight or ten inches below it.
F. F. Jorgexsex.
Gillespie. 111.
On one of the three-cylinder vertical 200-hp. gas en-
gines in the local electric-light plant the housing was
broken as shown by the heavy dotted lines in the illustra-
tion. The fracture began at the end bearing seat and con-
tinued around the corners and along both sides, terminat-
ing at the manholes in each side. On one side of the end
Showing How Plate Was Eiveted to Housixi;
vertical center line the break extended upward and down-
ward until there was practically no support for the bear-
ing and shaft and part of the weight of the revolving part
of the generator.
The builders of the engine advised that the least time
in which they could furnish a new casting completely
machined would be three weeks, which meant a serious
delay for the lighting company.
A local firm guaranteed that it could repair the
housing in three days from the time of delivery at
its works. The offer was accepted, and a very sub-
stantial job was accomplished. The repair plates are T%-
in. boiler plate formed to fit the casting as shown, and
a] care was exercised to make a good fit around the
circular flange at the bearing seat. Where possible the
plates were secured to this flange with %-in. machine
screws fitting in reamed holes that penetrate sufficiently
into the casing flange to insure a true surface for the end
face of the bearing. In the other parts %-in. rivets
were used, and around the corners these extended
through, with heads against the fillets on the inside of
the housing.
On the whole this repair job. while a big one, is entire-
ly satisfactory, and besides saving much time, proved
cheaper than a new housing.
Franklin. Penn. M. E. Griffix.
Having read the several letters in recent issues of
Power* relative to priming centrifugal pumps. I submit
the following description of a method that I used success-
fully on a three-stage pump. This was connected to 21
drilled wells and discharged into a standpipe about 160
ft. above the pump. The wells were divided, ten on one
and eleven on the other side of the pump, with a check
valve in each lead.
An old belt-driven air compressor was used as a vacuum
pump, and the suction was connected between the wells
and the check valves. The suction pipe was run up
through the chimney, which gave it a total height of 40
ft., so that the pump would not draw water into the cylin-
der. The pump suction pipe between the check valves
and pump was tilled with water and the air pump started.
After the air was exhausted from the suction pipe, the cen-
trifugal pump was started.
Marshfield, Wis. Louis B. Carl.
The letters on this subject appearing in recent issues of
Power are interesting and instructive.
About two years ago I installed four centrifugal pumps,
each of which had a suction lift from 12 to 16 ft. The
sui tion pipes were from 4 to 10 in. in diameter and the
discharge pipes 4 to 8 in. Two of the pumps were used for
pumping sewage and two for clear water. The speed was
from 1250 to 1500 r.p.m., the discharge lift from 30 to 70
ft. Each suction pipe had a foot valve (they could not be
kept tight on the sewage pumps) and a strainer at the in-
let end. There never was any trouble in priming these
pumps. The facilities for priming consisted of a 2-in.
pipe connected to a tank 30 ft. above the pumps. The
tank was always kept full of water.
A 1-in. branch pipe from the 2-in. line was run to each
pump and a 1-in. straight-way valve put in each branch.
All the pumps had water-sealed shafts and were direct-
connected to alternating-ettrrent motors from 35 to 125
hp. The valve on each discharge pipe was opened only
after speeding up the pumps. From two to four minutes
was the time required to prime. A vacuum gage was at-
p. 294: Apr. 6, p. 4S1; Apr. 20, p. 550; May
June 8, 1915
POWER
789
tached to each suction pipe and a pressure gage to each
delivery pipe between the pump and the delivery pipe
valve.
James E. Noble.
Toronto, Ont.
X
Asa Accadleiatt Pire\y©K5}&@dl
The illustration shows how a sheet-iron wheel-pit guard
prevented a flywheel from slipping otf the shaft and prob-
ably causing serious damage. The diameter of the wheel
is only 30 in., but it is in such a position that had it
slipped off it would have wrecked the main unit of the iso-
Key Hei.h ix Plate by Guard
lated plant. One of the attendants noticed that the wheel
was not running true, and it was found that the key was
very loose and a new one had to be made.
Samuel L. Robinson.
Providence. R. I.
I have read ('. II. Bromley's lecture on steam turbines
in the May 11 issue. In the latter part he offers sugges-
tions on starting and running a turbine, and it does not
appear to be clear what type of machine he had in mind.
To pick out one or two statements: "Now close the
drains of the stages. The gear may then be oiled. The
main turbine may vibrate considerably while being
brought up to speed" . . . "to get the rotor above the
"critical speed,' when the vibration will ordinarily cease"
Mr. Bromley's opening remarks undoubtedly refer to
a multi-stage turbine; in fact, one might gather that he
has particular reference to a Curtis vertical machine. He
then appears to refer to a De Laval single-stage impulse
turbine in the same breath, as it were, for no multi-stage
units are built with shafts which run above their critical
speeds; in fact, to my knowledge this characteristic is
peculiar to the original single-stage impulse De Laval,
with its flexible shaft. T might also add that if the gears
which Mr. Bromley mentions did not receive oil imme-
diately they started to revolve, instead of after the Load
was thrown on. the beat generated would soon cause
abrasion of the teeth.
He refers also to clearances between the blade teeth and
the casing. As every turbine man knows, the radial clear-
ances for an impulse turbine can be much greater than
for a reaction, due to there being no pressure difference
between the two sides of any one wheel, wdiereas with the
reaction type these must be reduced to the smallest prac-
tical amount. There are also other statements on which
comment might be made, such as. "sometimes an elevated
tank is used for supplying oil at starling and stopping."
The gravity system, comprising the elevated tank with
cooling coils and Biter placed below, is m general use.
R. X. Austin.
Toronto, I mt., ( Ian.
1 was much interested in Mr. Bromley's lecture on the
steam turbine, appearing in the May 11 issue of Power,
particularly in his instructions for starting.
He says the turbine may vibrate considerably while
being brought up to speed and that the admission of a
little more steam quickly to get the rotor above the "criti-
cal speed" will ordinarily cause the vibration to cease.
Although his instructions seem to apply to the Curtis
turbine, this point is also true of the Westinghouse ma-
chine. If, however, the turbine is started about fifteen
or twenty minutes before il is needed for the load and
slowly brought up to speed, the vibration at the "critical
speed" will be reduced to a minimum and in some cases
done away with altogether.
John Tooker.
Richmond Hill, X. Y.
Recently, there was installed in our plant, a 15,000-hp.
waterwheel driving an alternator. The plant operates un-
der 375-ft. head and the unit runs at 375 r.p.m., the pres-
Baffle ix Draft Tube Stopped Water-Hammer
sure at the waterwheel being 158 lb. When operating at
,•";, gate opening, it was found that water-hammer occurred
in the draft tube, causing the pressure in the pipe line
to rise 25 lb. and starting leaks in the 7-ft. wooden-
pipe line.
The theory of the engineer was that, owing to the con-
struction of the draft tube, the velocity of water at that
790
POW f. i;
Vol. H. No. 23
particular gate opening was such that the whirling mo-
tion through the wheel set up a counter-current in the
center of the draft tube, causing the water to come back
the wheel ami raising the pressure. The vacuum
ui the draft tube varied from 15-in. vacuum to 5-lb.
back pressure under this condition of water-hammer.
The engineer stated that a baffle placed in the draft tube
t«> break up this whirling motion would cure the trouble,
and a piece of boiler plate 1 in. thick and 18 in. wide
was then placed therein, as shown in the accompanying
sketch.
This cured the difficulty and since then no trouble has
been experienced.
J. B. Crane.
Duluth, Minn.
MowaE&gj P-oaiflBpiir&gj E,jr&g>aEae§ h>$r
Wattes5 Piress^as5©
Handling pumping engines of the large sizes calls for a
method of procedure peculiar to itself. They must be
moved a small distance at a time and also held se-
curely in position.
Multiple-expansion pumping engines are not usually
built with reversing gears, and it is customary to move
Discharge \
Pipe Connections fob Water Pressure
them forward or backward a small amount with water
pressure. I submit the simple illustration of the pipe
connections to the plungers and valve chambers of a
twenty-million gallon pump.
The engine is of the vertical triple-expansion type.
The three cranks are set at 120 deg. apart. We have ac-
cess to a 100-lb. water pressure which is brought to bear
under the plunger whose crank happens to be in position
to be raised. This moves the entire engine. By the
manipulation of a set of bypasses the discharge area,
plunger chamber and suction area arc thrown open to
water pressure and release as desired.
Edward T. Bixxs.
Philadelphia. Penn.
Hira<c£5egvsaE&g|
An appliance for increasing the amount of water that
will flow through the outlet of a shallow tank when the
depth of the water does not exceed three times the diame-
ter of the outlet may be easily made in the following man-
ner :
Cut a sheet-metal disk of suitable thickness four times
the diameter of the outlet, and a hole in the center of
Disk over Taxk Outlet
the disk the size of the outlet. Lay out the flange in six
equal parts (see illustration). Cut the disk on the full
lines marked A and bend on dotted lines B, bringing
the planes C to a vertical position and at right angles
to D, thus forming six wings. Place the appliance di-
rectly over the outlet, using the plane D as the base. The
plane C eliminates the whirling motion of the water and
allows it to run out in a steady stream.
E. A. Buchanan.
Colfevville. Kansas.
When it comes to versatility for the fireman we cer-
tainly have to hand it to North Carolina. In this state he
can assume such roles as best' meet any and all occasions,
playing the part of fireman, scrubman, bath artist, etc.,
with full permission of the law. In fact the law helps
him to it. as shown by the following interesting extract
from the State Public General Laws of 1911, and now
operative :
Section 1 (Chapter 156). That the fireman of the Supreme
Court building shall be appointed by the chief justice and
associate justices of the Supreme Court, and when not en-
gaged in his duties as fireman shall act as assistant janitor
of the Supreme Court, and shall assist in the cleaning and
care of the Supreme Court and perform such other duties
as may be designated by the said justices of the Supreme
Court.
This law, granting these great privileges, is the noble
work of the General Assembly. How many members of
that honorable body ever visited a boiler-room to learn
what firing really meant?
L. P. W. Allisox.
Xewark, X. J.
June 8. 1915
POWER
;:m
.imqpunriies
©mere
iimfeFesil
urn iiiiiiiii
LonR-Ranee Cutoff for Corliss Engine — How can long
range of cutoff be secured with a Corliss engine?
J. C. H.
By supplying the engine with a separate eccentric for
operation of the steam valves.
Submersed Piston vs. Straightway Pump — What is the
difference between a submerged piston and straightway pump?
W. C. O.
Submerged piston pumps are like the ordinary duplex feed
pump with both suction and discharge valves above the water
pistons, the latter being submerged, while in the straightway
pattern the suction valves are below and the discharge valves
above the water pistons.
Terminal Pressure — What is meant by terminal pressure?
S. H. J.
Terminal pressure is the pressure that would be in the
cylinder at the end of the stroke of the piston if the exhaust
valve did not open until the stroke was completed. On a
steam-engine indicator diagram the terminal pressure may
be found by extending the expansion curve to the end of the
diagram. The theoretical terminal pressure is found by di-
viding the pressure at cutoff by the ratio of expansion.
Piston Displacement — What is meant by the term "piston
displacement"?
C. A. G.
Piston displacement is the space, usually reckoned in cubic
inches, through which the piston sweeps in a single stroke.
It is found by multiplying the area of the piston, in square
inches, by the stroke in inches. The displacement of a pump
piston would be the number of cubic inches of water dis-
charged by one stroke, if there were no leakage or slippage.
Spouting Velocity of Liquid — What is the "spouting ve-
locity of a liquid?
S. H. H.
The velocity with which a liquid under pressure issues
from an orifice, and unless otherwise qualified, the term is
used to signify the theoretical velocity that would be due to
the head or pressure of the liquid at the entrance of the
orifice, as given by the formula,
v = i/"2~i£
in which
v = Velocity in feet per second;
2g = 64.32;
h = Head in feet, equivalent to the pressure.
Absolute Pressure for Inches of Vacuum — What would be
the absolute pressure with 26 in. of vacuum and 29.5-in. ba-
rometer?
M. W. C.
Inches of vacuum signifies pressure in inches of mercury
column below the pressure of the atmosphere; hence, with a
barometer reading of 29.5 in., 26 in. of vacuum would repre-
sent an absolute pressure of
29.5 — 26 = 3.5 in. of mercury.
At ordinary temperatures each inch of mercury may be taken
as equal to 0.491 lb. per sq.in., therefore the absolute pressure
would be
3.5 X 0.491 = 1.71S5 lb. per sq.in.
Stacks Mounted on Boiler Settings— What are the advan-
tages or disadvantages of having independent steel stacks
set directly over the front smoke connections of return-
tubular boilers?
W. L. B.
Stacks erected in that manner have the advantages of af-
fording direct and independent draft and a saving of ground
or floor space required for independent bases and foundations.
They have the disadvantages of requiring special supports and
also of usually requiring reinforcement of the front ends of
the boiler settings to prevent the settings from being racked
by wind movement of the stack. They also present difficul-
ties in providing protection of the front end of the boiler and
setting from damage by rain water carried down inside or
outside of the stack.
Designation of Superheated Steam — How is the amount of
superheating of steam designated and how is it usually de-
termined?
S. W.
Superheating is designated in degrees of superheat, mean-
ing the number of degrees by which the actual temperature
of the steam exceeds the temperature of the boiling point
corresponding to the pressure which is under consideration.
For practical purposes the number of degrees of superheat
present is usually determined by ascertaining the actual tem-
perature of the steam by a thermor leter and deducting the
temperature of saturated steam for the given pressure, as
found from the steam table. Thus, if the gage pressure of the
steam is 150 lb. per sq.in. and a thermometer inserted in it
shows that its temperature is 470 deg. F., then, as the tem-
perature of saturated steam for the pressure is about 366 deg.
F., there would be
470 — 366 = 104 deg. of superheat.
Relative Economies of Evaporation — If, with an average
temperature of feed water of 44.4 deg. F., a boiler evaporates
36,315 lb. of water into dry saturated steam at an average
gage pressure of 110.4 lb. per sq.in., using 5326 lb. of coal,
what would be the relative economy with an evaporation of
39,000 lb. of water from a feed temperature of 45 deg. F. into
dry saturated steam at an average gage pressure of 107.6 lb.
per sq.in. and using 5600 lb. of coal, the kind of coal, duration
of trials and other conditions being the same?
M. T. J.
In the first instance the actual evaporation would be 36,315
-r- 5326 = 6.818 lb. of water per pound of coal. A pound
(weight) of steam at 110.4 lb. gage pressure or about 125 lb.
absolute contains 1190.3 B.t.u. above 32 deg. F., and as each
pounds of feed water at 44 deg. F. contains 44.4 — 32 = 12.4
B.t.u. above 32 deg. F., the heat received by each pound of
water evaporated would be
1190.3 — 12.4 = 1177.9 B.t.u.
As the heat required for evaporation of a pound of water
from and at 212 deg. F. is 970.4 B.t.u.. the factor of evapora-
tion would be
1177.9-^970.4 = 1.2138
so that the evaporation of 6. $18 lb. of water per pound of
coal would, under the conditions, be equivalent to the evap-
oration of
6.818 X 1.2138 = 8.2757 lb.
of water from and at 212 deg. F. per pound of coal.
In the second instance the actual evaporation would be
39,000 -s- 5600 = 6.964 lb. of water per pound of coal. As the
gage pressure of 107.6 lb. per sq.in. would be equal to about
122 lb. absolute, each pound (weight) of steam would contain
1189.8 B.t.u. above 32 deg. F. With feed water at 45 deg. V.
each pound evaporated into steam would receive
1189. S — (45 — 32) = 1176. S B.t.u.
the factor of evaporation would be
1176. S H- 970.4 = 1.2132
and there would be an evaporation equivalent to
6.964 X 1.2132 = 8.44S7 lb. of water per pound of coal.
Therefore, in the second instance there would be
.448
8.2757
X 100 = 2.09 per cent.
8.2757
more water evaporated per pound of coal, and for evaporation
of the same quantity of water the percentage less of coal
would be
.44ST /
X 100 X 8.2757 = nearly 2.05 per cent.
Such small variations of conditions would be required to
make the evaporative economies equal that, for all practical
purposes, the results may be regarded as identical.
[Correspondents sending us inquiries should sign their
communications with full names and post-office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
r92
POWER
Vol. 41, No. 23
Legislations nun tha
o
A. Pot i i i;1
Thirty-four states have no state laws at present and no
proposed state legislation for licensing stationary engineers.
They are: Alabama, Arizona. Arkansas, Colorado, Connecti-
cut Florida. Georgia. Idaho. Iowa. Kentucky, Louisiana.
Maine. Maryland, Michigan, Mississippi. Missouri, Nebraska,
New Hampshire. New Mexico. New York, North Carolina,
North Dakota. Tennessee, Utah, Vermont, Virginia, Wash-
ington, "West Virginia, Wisconsin and Wyoming.
Nine states — California, Delaware, Illinois, Indiana, Kan-
sas. Minnesota, Pennsylvania, Rhode Island and Texas — had
laws pending in 1915. Charles H. Wirmel, chairman of the
N. A. S. E. License Committee, asserted that a state law is
pending in Washington. I have been unable to secure from
the secretary of state at Washington any confirmation that
such a law is before their legislature.
In Indiana an attempt has been made several times to
have a state license law passed, but without success. The
manufacturers, farmers, and even many of the operating en-
gineers fought the bills introduced.
Several unsuccessful efforts were made to enact a state
law in Missouri, but nothing was brought up at the 1915
session of the legislature. The State of New Hampshire has
certain laws regarding engineers operating steamboats.
North Dakota, in Sec. S994 of the 1905 Revised Codes, holds
the engineer or other person having charge of steam boilers
and engines responsible and guilty of a misdemeanor for ac-
cidents whereby human life is endangered.
The states having city laws include Alabama, California.
Colorado, Connecticut. Indiana. Iowa, Illinois, Louisiana,
Maryland, Michigan, Nebraska. New Jersey. New York, Penn-
sylvania. Tennessee, Washington and Wisconsin. These laws
were given in detail in the "Report of the License Committee
of the N. A. S. E." in 1906.
The act of the general assembly of the State of Louisi-
ana empowers municipalities of over 50,000 inhabitants,
through their local councils, to regulate the use of stationary
and portable steam boilers, and to constitute and appoint a
board of examiners of stationary and portable steam-boiler
engineers for the carrying out of this purpose . . . em-
powers said municipalities to require persons operating steam
boilers .... to have in their possession and posted in con-
spicuous places in the engine room where employed as such,
certificates of authority . . . This act further requires
owners to have none but certified engineers, having proper
certificates and renewals thereof.
Missouri has at present the following law: "Xo person
is authorized to manage, control or take charge of or act as
engineer of any steam boiler, engine or apparatus, who has
not the requisite knowledge or ability to manage the same
with safety to the lives and property of the inhabitants of
such cities. Any incorporated association of qualified local
steam engineers in any city is authorized to appoint an ex-
amining committee for the granting of certificates of qualifi-
cations." Provision is also made that no charge exceeding
one dollar is to be made for any certificate.
The State of Maine has certain laws pertaining to school
buildings, churches or other public buildings when heated
by a steam plant located in, under or near such building.
EXISTING AND PROPOSED LAWS
Examiners — The state license laws are under the jurisdic-
tion of the boiler-inspection department of the District Police
in Massachusetts. In Montana the state boiler inspectors at-
tend to the licensing of engineers. In Nevada the boards of
county examiners regulate the operation of stationary and
hoisting engines. The state laws of Nevada are not very
extensive or definite, but aid in protecting life and prop-
erty. The district examiners, who are under the Industrial
Commission of Ohio, examine applicants for licenses, while in
New Jersey this power is vested in a bureau of the Depart-
ment of Labor, known as the "Steam Engine and Boiler Oper-
ators' License Bureau." In Minnesota 53 inspectors are ap-
pointed by the governor and these examine engineers, is-
sue licenses and inspect boilers. This system makes it pos-
sible to build up quite a political patronage. A new bill has
'Paper presented before the Kansas State Convention of
the National Association of Stationary Engineers at Wichita,
on May 14, 1915.
tDean of the Division of Engineering and Professor of
Steam and Gas Engineering at the Kansas State Agricultural
Co. lege.
• introduced into both branches of the Minnesota legis-
lature this year which is indorsed by the Minnesota State
Association of the N. A. S. E., the main features of which
will be brought out later.
Among the states having proposed state license laws in
1915. California. Illinois and Pennsylvania have an examining
board consisting of one chief engineer and several assistant
examiners. In Indiana an examining board is appointed by
the governor, but this board is under the supervision of the
chief inspector of the State Bureau of Inspection, who is ex-
officio the president of the examining board. In California
the examining board is appointed by the commissioners of the
Bureau of Labor Statistics. In Minnesota and Texas one ex-
aminer is appointed for each congressional district. The con-
tents of the bills for Delaware and Rhode Island could not
be secured. The proposed state law of Kansas vested the
licensing power in an "Engineers License Committee."
In the majority of states a person to be eligible as ex-
aminer must have ten to fifteen years of practical experience.
License Required — Those exempted from license require-
ments include operators of locomotives, motor road vehicles,
boilers in private residences, boilers and engines under the
jurisdiction of the Government of the United States, boilers
carrying not more than 15 lb. pressure, boilers and engines
i stationary and traction) when used for agricultural pur-
poses exclusively.
In Illinois and New Jersey the exemptions include boil-
ers carrying not more than 10 lb. pressure and in Illinois only
heating plants which serve 50,000 sq.ft. radiation or less. In
California boilers less than 4 hp. and also those used in log-
ging camps or in pumping or boring wells for oil or water
are exempted. The proposed bill of Indiana and Ohio ex-
empts boilers used in the production of crude oil. In some
states the existing or proposed laws exempt only such heat-
ing boilers as are provided with a device approved by ex-
aminers, limiting the pressure to 15 lb. Apartment houses
to be exempt must have less than five flats. In several
states fire-department engines are exempt.
The exemption limit for boilers and engines is 9 hp. in
Massachusetts. 30 hp. in Ohio and Pennsylvania, and 250 hp.
in Texas. In Texas this high limit is fixed in order to ex-
empt all ginners. contractors and sawmills of the state. In
Pennsylvania first- and second-class cities are exempt from
the state license act, such cities having municipal license
laws.
Classification of Licenses — Several of the proposed bills
seem to be in favor of making no differentiation between
grades or classes of engineers. California, Indiana, Illinois,
Nevada, New Jersey and Pennsylvania have such bills in
force or proposed. A large number of the cities of the first
class have unclassified license laws, the opinion being that the
license law is mainly for the protection of life and property.
The Massachusetts license law includes four different
classes of engineers' licenses, three classes of firemen's
licenses and a special license for particular plants.
The proposed law of Minnesota calls for four classes of
engineers' licenses and also a special license for portable,
traction or agricultural engines.
In Montana there are three classes of engineers' licenses
and a traction-engine license. Firemen not under the direct
charge of an engineer are required to have a third-class
license.
Ohio classifies engineers' licenses into first, second and
third grades. These licenses are granted partly upon the
percentages received in the examination, as will be ex-
plained in the next section.
The Texas bill grades engineers into three classes — first,
second, and special. The owner or lessee is held responsible
for the engineer carrying a special license.
The proposed Kansas bill provided for two grades of
engineers' licenses.
Requirements for Licenses — All proposed state bills make
provision for issuing licenses to engineers engaged in the
practice of their occupation at the time the licensing act
takes effect.
In Massachusetts where the licenses are classified, to be
eligible for a first-class fireman's license a person must have
been employed as a steam engineer or fireman in charge of
or operating boilers for not less than one year. The third-
class engineer's license requires one and one-half years' ex-
June 8, 101 '
POWER
793
perience, the second-class engineer's license two years' ex-
perience In a plant having at least one engine of over 50
horsepower. A person who has served an apprenticeship for
three years to the machinist or boiler-making trade or is a
graduate of a recognized engineering college, is eligible to
take the second-class engineer's examination if he has been
employed for one year in connection with the operation of a
steam plant. Three years' experience in a power plant hav-
ing at least one engine of 150 horsepower is the requirement
for first-class license examination.
The proposed act of Minnesota requires Ave years' ex-
perience for first-class license, three years' experience for
second-class, and one year's experience for third-class license.
In Montana the requirements are three years' experience
for first-class license, two years' experience for second-class
license, and one year's experience for third-class license.
In Ohio a first-class license is granted to applicants who
have had three years' practical experience and who obtain a
percentage of 85 or more in the examination. Two years' ex-
perience and a percentage rating of from 70 to 84 entitle
the applicant to a second-class license, while the third-grade
applicant must have one year's experience and an examina-
tion rating of from 60 to 69.
No definite requirements were outlined for the two grades
of licenses in the proposed Kansas bill.
A clause should appear in bills or acts giving special
authority to representatives or erecting engineers of any
manufacturers of boilers or engines when employed in in-
stalling, testing, or operating boilers or engines.
Fees for Licenses — Illinois and Ohio, $2 for license and $2
for yearly renewal. California, Nevada and Texas charge
$5 for license. Nevada has no renewal requirement, while
California and Texas charge annual renewal fees of $2 and
$5 respectively. The proposed law of Pennsylvania has $3
for license and $1 for renewal. In Montana the charges are:
$7.50 for first-class license, $5 for second-class, $3 for third-
class and special, and $1 for yearly renewal for all grades.
The proposed Kansas law provided for $5 fee in the case of
first-class license, $3 for second-class, and yearly renewal
charges for the two classes $3 and $2 respectively.
The present Minnesota law allows the inspector to grant
licenses for a fee of $1, which he pockets. The proposed law
includes $2 for examination and $1 for annual renewal.
Appeal from Refusal of License — A person who is ag-
grieved by the action of an examiner in refusing or revoking
a license has the right of appeal therefrom in all states ex-
cept in Massachusetts, where the action of the examining
board is final. In several states the applicant has the privi-
lege of having one outside person during the examination or
during the hearing of an appeal. This person is not allowed
to take part, but can take notes if he so desires.
Posting of License — In the majority of states the act re-
quires that the engineer's or the firemen's license be placed
in a conspicuous position in the engine room of the plant
operated by the holder of such license.
Operation without License — In Massachusetts a person
without a license is allowed to operate a plant for one week,
in Pennsylvania ten days and in Montana for a period of
fifteen days, provided notice to that effect is sent to the in-
spector. In the majority of cases no provision is made
authorizing operation without license.
Records of Operation — The Massachusetts law requires "a
daily record of the boiler, its condition when under steam and
all repairs made and work done on it" upon regular printed
forms furnished by the boiler-inspection department.
Boiler Inspection — The states of Colorado, Connecticut,
Massachusetts, Minnesota, Montana, Nevada, New York, Ohio,
Pennsylvania and Wisconsin have boiler-inspection laws. In
Colorado the governor appoints a chief and three deputy
boiler inspectors who test every stationary boiler annually.
The same is the case in Connecticut, where a boiler inspector
is appointed from each congressional district.
In Massachusetts and in Ohio, besides the boiler-inspec-
tion department, which is responsible for the inspection of
boilers, there is a "Board. of Boiler Rules." The chief in-
spector of the boiler-inspection department is the chairman of
the board of boiler rules, the other members being selected to
represent the boiler-using interests, the boiler-manufacturing
interests, the boiler-insurance interests and the operating en-
gineers. The board of boiler rules formulates rules for con-
structing, inspecting, installing and testing of boilers.
Montana seems to have had boiler-inspection laws for
many years. The 13th Biennial Report of the state boiler in-
spector shows that even in such a large and thinly populated
state as Montana the boiler-inspection department has not
only been self-sustaining, but has produced a revenue for the
state, over all expenses, of nearly $16,000. The state has no
record of a serious boiler explosion.
In New York the state Are marshal has charge of boiler
inspection.
[This office has been discontinued and the duties of boiler
inspection transferred to the factory inspector. — Editor.]
In Wisconsin boiler inspection is under the Industrial
Commission, which has a standard code of rules for the con-
struction, operation and inspection of boilers. This commis-
sion accepts inspections from qualified inspectors in cities of
the first, second, and third class.
The fees for boiler inspection are, in the majority of
states, $5 for external and internal inspection of each boiler
and $2 when the boiler is only externally inspected under
steam pressure. In Connecticut provision is made for in-
specting steam boilers owned by farmers, once in two years
for a fee of $2, provided such boilers do not exceed 5 hp. each.
In Montana a charge of $10 is made for the inspection of a
single boiler and $5 for each additional boiler.
The present law of Minnesota allows the inspectors to
charge $3 for each boiler inspection and to keep such fees.
The proposed law of Minnesota places a fee of $3 for the in-
spection of a single boiler and $2 for the inspection of each
additional boiler.
In this connection the recent act before the 1915 Pennsyl-
vania legislative session is of some interest. This act re-
quires municipal inspection of steam and hot-water installa-
tions and provides for the examination, licensing and regis-
tration of persons, firms or corporations engaged in the
business or work of steam and hot-water fitting.
DISPOSITION OF 1915 BILLS
It may be of interest to report the status of the bills pro-
posed in 1915: The Kansas bill was killed in the committee.
The Delaware, California, and Rhode Island bills were lost.
The proposed license-law bill of Pennsylvania was declared
unconstitutional by the attorney-general, principally on ac-
count of its exemptions. An act for the licensing of engi-
neers in third-class cities of Pennsylvania passed through the
committee and it is understood has a good chance of passing
the House. In accordance with this bill, the city council ap-
points an examining board, consisting of two engineers who
have had not less than six years' practical experience, to act
in conjunction with the director of public safety. The pro-
posed engineers' license and boiler-inspection law of Minne-
sota was defeated in the Senate on Feb. 18, after much hard
and creditable work on the part of the Minnesota State As-
sociation of the N. A. S. E. No definite information could be
secured regarding the ultimate fate of the bills proposed in
Illinois, Indiana and Texas.
At the seventh annual convention of the International
Railway Fuel Association, W. L. Robinson, supervisor of fuel
consumption of the Baltimore & Ohio R.R., read an interesting
paper outlining the advantages that might result from the use
of powdered coal in locomotive furnaces. The cost of fuel
for the 65,000 steam locomotives in use in the United States
is from $250,000,000 to $275,000,000 per annum, and now rep-
resents about 25 per cent, of the total transportation-account
expenses. The fuel used is principally bituminous coal, an-
thracite, fuel-oil, lignite and coke. While powdered coal
has been used successfully and rather extensively for years in
cement and metallurgical furnaces, its use for steam-making
purposes has been limited, owing to the lack of practical
development. Its possibilities, however, are great, and if the
practical difficulties can be overcome, the saving for the
various railroad companies throughout the country will be
on a corresponding scale.
Coal in a finely divided or powdered state represents the
most advanced method for producing perfect combustion.
While a cubic inch of solid coal exposes only 6 sq.in. for
absorption and liberation of heat, a cubic inch of powdered
coal exposes from 20 to 25 sq.ft., which enables the more
uniform gas production from the volatile matter in the coal
and the more prompt and perfect intermingling of gas and
air, thereby improving combustion and reducing smoke. Fur-
thermore, there is no cooling of the fire by heavy intermittent
charges of fresh coal, as is the case with hand or stoker
firing on grates.
It has been generally thought that for the burning of
solid fuels in powdered form in suspension, a bituminous coal
of less than 30 per cent, volatile matter could not be used with
satisfactory results. Mr. Robinson, however, had been in-
formed that good results were being obtained in locomotive
practice from semibituminous coal analyzing as low as 21
per cent, volatile and having 15 per cent, ash and moisture.
To give the best general results and the least trouble from
ash and slag, powdered coal should contain not more than
1 per cent, moisture and be of a uniform fineness, so that
04
row e 1;
Vol. 41. No. 33
not less than 95 per cent, will pass through a 100-mesh, not
less than S5 per cent, through a 200-mesh, and not less than
TO per cent, through a 300-mesh screen.
COST OF POWDERING
The cost of preparing powdered coal will vary with the
cost for the raw coal and its moisture content. However, a
ger.?ral average from available data covering periods of the
past five to ten years at cement and metallurgical plants has
made it possible to present the following conservative esti-
mate, assuming the cost of the raw coal at from $1 to $2
per short ton. and that it will require crushing and have a
moisture content of from 5 to 10 per cent, when placed in the
drier:
Capacity of riant in Average Total Cost for
Short Tons per Hour Preparation per Short Ton
2 From 25 to 50 cents
3 From 20 to 45 cents
4 From 16 to 40 cents
5 From 14 to 35 cents
10 From 12 to 30 cents
25 From 10 to 20 cents
The fuel required for drying the coal will average from
1 to 2 per cent, of the coal dried. The distribution of the
total may be approximately stated as follows:
Fuel for drying 10 per cent.
Power for operation 30 per cent.
Labor 30 per cent.
Maintenance and supplies 25 per cent.
Interest, taxes, insurance and depreciation 5 per cent.
Total 100 per cent.
The cost of preparing powdered coal should be more than
offset by the ability to utilize mine refuse and sweepings,
run-of-mine, screenings and slack grades of coal that cannot
be used to good advantage otherwise, and inferior grades
of sub-bituminous coals, lignite and peat of relatively lower
cost per ton than the readily salable commercial fuels.
Powdered coal may be burned by either of two generally
defined methods — the long-flame method, constituting a pro-
gressive burning of the coal such as is employed in cement
and openhearth furnaces, and the short-flame method, which
is the latest development and is used in metallurgical and
similar metal-heating work or under boilers where a similar
furnace volume obtains. A combination of the long- and
short-flame methods has been tried recently on a New York
Central locomotive equipped for burning powdered coal.
LOCOMOTIVE MODIFICATIONS REQUIRED
For locomotive work the principal requirements are an
inclosed fuel container, means for conveying the fuel to the
feeders, means for commingling the fuel with air at the time
of feeding, and afterward equipment for supplying the proper
amount of air to produce a combustible mixture at the time
the fuel and air finally enter the furnace, a suitable refractory-
material furnace in the firebox, means for disposing of the
slag, means for producing the proper draft through the
furnace and boiler, means for harmonizing the draft and the
combustion, suitable power for operating the fuel- and air-
feeding mechanism, and automatic and hand control of the
fuel and air regulation.
It is understood that the developed equipment for burning
pulverized fuel can be readily applied to all existing modern
types of steam locomotive without any changes in the boiler
except to install arch brick supporting tubes, where fireboxes
are not now equipped, and to remove the grates, ashpan and
smokebox draft appliances. There is no equipment in the cab
except the automatic hand control, which is placed in a
position convenient to the fireman. The inclosed fuel con-
tainer is suitable for either powdered coal or fuel oil and
either kind of fuel can be used by changing the feeding equip-
ment. The total weight of equipment applied will about
equal that of the equipment removed. When not in operation
the necessary draft through the boiler is obtained by the usual
stack steam blower, and by exhaust steam from the cylinders
when the locomotive is working. The supply of fuel is
regulated according to the work the locomotive is performing,
and when drifting or standing on sidings or at terminals,
it can be entirely shut off. The exhaust-nozzle opening is
about double the area of that used for grate firing.
Some of the advantages enumerated were the sustained
boiler horsepower obtained from the use of powdered coal,
the ability to increase the economical length of run, the firing
of the boilers automatically with no hand-labor, the preven-
tion of cinders, sparks, and smoke; the reduction in cylinder
back-pressure due to the enlarged exhaust passages; saving
in inspection, maintenance and operation through the elimina-
tion of grates, ashpans, dampers, etc.; a more uniform furnace
temperature, reducing the liability of firebox and flue leakage;
ability to make use of inferior qualities and grades of solid
fuel: reduction of delay from cleaning or dumping fires; and
a number of other factors which would tend to improve
efficiency and lower the cost per car-mile.
DISCUSSION OF THE PAPER
The paper aroused a great deal of interest, and the subject
was considered of enough importance to appoint a permanent
committee to keep posted on developments in this field. In
the discussion some of the difficulties experienced in burning
powdered coal were brought to light. The principal objection
and the most serious factor interfering with the continuous
operation of the locomotive was the formation of large quanti-
ties of slag, which clings to the boiler plates, fills up the
tubes and forms on the superheating surface. E. H. Stroud,
a maker of powdered-coal equipment, who has had consider-
able experience in an experimental stationary plant equipped
for burning powdered fuel, explained that there were several
essential factors which must be given attention to burn this
coal successfully. First, it is necessary to powder the coal
to the proper fineness. This is vital, because instantaneous
ignition within a few inches of the burner must be obtained.
Unless complete combustion is obtained at once, slag will
form. The furnace must get the proper amount of air, and
to insure a correct mixture mechanical means to measure the
coal and air are required. Slag was an objectionable feature,
but there is no occasion to permit it to get as far as the
boiler tubes. All of this could be precipitated in a chamber
formed by a specially constructed arch at the rear of the
firebox. It was his conviction that it paid to dry the coal.
This could be done while it was being pulverized. The cost
of pulverizing, including power, wear and tear and attendance,
at a rate of 5 to 10 tons per hour, should not exceed 15c.
per ton. Drying would add 4 to 6c. per ton. As to a capacity
of individual units, burners could be made which would
burn as low as 15 lb. per hour and as high as 5000 lb. per hr.
Joseph Harrington, who has recently become associated
with the Powdered Coal Engineering & Equipment Co., of
Chicago, discussed the question from the standpoint of smoke
abatment. In Chicago and many other municipalities electri-
fication has been urged because it eliminates smoke, soot,
cinders, sparks and excessive noise. Within the City of
Chicago alone the cost to electrify the railroads has been
estimated at $190,000,000. It would appear that the same
results can be obtained by the use of powdered coal, at a
cost which would be insignificant in comparison. A uniform
system would be maintained on the railroads and according
to an estimate by Mr. Robinson, the use of powdered coal
would result in a saving on various heat losses alone of
25 per cent. This does not include savings from the preven-
tion of smoke, soot, cinders, sparks, ash-handling, the use
of inferior grades of soft coal, elimination of smoke inspectors,
which in Chicago alone costs the railroads $65,000 per annum,
and the solution of other problems that enter into the pro-
duction of steam power in locomotives.
1C JU6'
It is conservatively estimated that within a radius of ...ty
miles from Ottawa, there is available water power of ap-
proximately one million horsepower. The Ottawa River alone
would supply 700,000, and its tributaries 300,000 horsepower.
This estimate is based upon an average of water obtainable
throughout the year from twelve to fourteen rivers. In this
section are many great lakes that can be converted into im-
mense reservoirs. A number of dams have been built on the
upper reaches of the Ottawa River, insuring when fully com-
pleted a steady supply of water throughout the year.
Eminent authorities, when calculating the relative cost of
hydro-electric and steam-generated energy, place the latter
on the basis of $25 per horsepower year. Estimating the cost
of the same power generated by water at $10 yearly, the
saving effected for an output of one million horsepower would
be fifteen million dollars. This power is all within a short
distance of Ottawa, and therefore can be transmitted to that
city very economically. The accompanying table was pre-
pared by Holgate. MeDougall and Ker, well-known civil and
hydraulic engineers, acting as a special commission for the
City of Ottawa. The data relate to existing installations
within thirty miles of the city.
Distance Hp. Output Cost per
_ i Miles) of Sub- Hp. per
Name of Power Site of Trans. station Year
Metropolitan Company 7 5,100 15.73
Metropolitan Compariv 7 11,050 13.89
Gatineau River 7 5,000 13.60
Gatineau River 7 10,000 8.80
Gatineau River 7 20, )
Lievre River 30 5.000 13.95
Lievre River 30 10,000 9.13
June 8. 1915
1' O W E If
795
Lievre River 30 ijn.min 6.99
Lievre River 3(1 30.000 6.06
chats Falls 30 5.000 13.20
Chats Falls 30 10,000 9.20
Chats Falls 30 20,000 7.80
Another section offering a splendid opening for enter-
prising capitalists to develop and exploit its water powers
and industrial resources is the Sault Ste. Marl"- district. The
Canadian share of the great falls on the "Soo" is yet un-
developed, while with the several falls on the Michipocoten
River and the Steep Hill Falls on the Magpie River, there is
easily 100,000 horsepower in the immediate vicinity. In the
district to the north, millions of dollars worth of iron and
other natural resources, the great spruce forests of the clay
belt and an unlimited pulpwood area are awaiting develop-
ment.
ioffiminn\aft(t©e ©eh Cl^@silScsiftn©Ea ©f
Delegates from iilmtit twenty national technical and scien-
tific societies met at the Engineering Societies Building, New
York, on May 21 to perfect a permanent organization, the
purpose being to prepare a classification of the literature of
applied science which might be generally accepted and adopted
by these and other organizations. It was the feeling of the
meeting that such a classification, if properly prepared, might
serve as a basis for the filing of clippings, for cards in a
card index, and for printed indexes; and that the publishers
of technical periodicals might be induced to print against each
important article the symbol of the appropriate class, so that
a file might be easily made which would combine clippings,
trade catalogs, maps, drawings, blueprints, photographs, pam-
phlets, and letters, classified by the same system.
By request, W. P. Cutter, librarian of the Engineering
Society's Library, read a paper on "The Classification of Ap-
plied Science," and after describing the existing classifications,
stated that in his opinion no one of these was worthy of gen-
eral adoption. He outlined a plan whereby a central office
could collect all the existing classifications and with the help
of the various national societies interested might compile a
general system which, although not absolutely perfect, might
be generally accepted.
The following societies were represented by delegates:
United Engineering Society. American Foundrymen's Associa-
tion, Society for Electrical Development, American Ceramic
Society, American Institute of Architects, American Society of
Agricultural Engineers, American Society of Refrigerating
Engineers, American Gas Institute, American Water-Works
Association, American Society of Mechanical Engineers, Na-
tional Fire-Protection Association. American Society of Heat-
ing and Ventilating Engineers, Society of Automobile Engi-
neers, Society for the Promotion of Engineering Education,
United States Bureau of Standards, American Physical Society,
Franklin Institute, American Institute of Mining Engineers,
American Society for Testing Materials, National Electric
Light Association, American Electro-Chemical Society, Illum-
inating Engineering Society, and American Railway Engineer-
ing Association.
The name adopted for this organization is "Joint Committee
on Classification of Technical Literature." A permanent organ-
ization was effected by the election of the following executive
committee: Fred R. Low, chairman; W. P. Cutter, 29 West
39th St., New York, secretary; Edgar Marburg, H. W. Peck
and Samuel Sheldon.
Me®diag ©f E-Eagiiraeeirlinig
P©,>mini<dlaifti©ini
The Engineering Foundation held its first regular meet-
ing May 25, and selected a board to administer the trust
founded by Ambrose Swasey, as described in our Feb. 2 issue.
The board consists of Charles Warren Hunt and J. Waldo
Smith, representing the American Society of Civil Engineers;
Dr. Alexander C. Humphreys and Jesse M. Smith, American
Society of Mechanical Engineers; Dr. A. R. Ledoux and Ben-
jamin D. Thayer, American Institute of Mining Engineers;
Charles E. Scribner and Dr. M. I. Pupin, American Institute
of Electrical Engineers; Edward D. Adams and Howard El-
liott, representing the general public. The officers elected
were: Gano Dunn, chairman, by virtue of his office as president
of the United Engineering Society; Edward D. Adams, vice-
chairman; F. R. Hutton, secretary, and Joseph Struthers,
treasurer.
A large number of applications have already been received
from those who want to use the funds for research work.
Because of the number of applications and the incomplete form
in which many of them were received, a schedule of require-
ments for applicants is being prepared by the following com-
mittee, which was chosen by the board: Dr. A. R. Ledoux,
chairman; J. Waldo Smith, Dr. M. I. Pupin and Dr. Alexander
C. Humphreys.
JecBsa®Ei§
STREET
Digi ted by A. L. H.
Spread of Fire by Portable Kngines — The law enacted by
the Wisconsin Legislature in 1913, requiring traction and port-
able engines to be equipped with a "screen or wire netting
on top of the smoke-stack and so constructed as to give the
most practicable protection against the escape of sparks and
cinders" and "with the most practicable devices to prevent
the escape of fire from ashpans or fireboxes," has just been
considered by the Supreme Court of the state in the case of
Legro vs. Carley, 150 "Northwestern Reporter," 985. The
court holds that the statute is sufficiently specific in its re-
quirements to be valid, and that a spark arrester in a thresh-
ing machine, consisting of an inverted cone of screen wire,
is not a sufficient spark arrester, if it has been permitted
to remain unrepaired after the point of the apex has burned
or rusted off.
Effect of Temporary Use of Gasoline Engine on Fire Risk —
A clause in a fire policy reading, "This policy shall be void
. . if camphene, benzine, naptha or other chemical oils
or burning fluids shall be kept or used by the insured, on
the premises insured," does not invalidate the policy on
account of the temporary use of a gasoline engine, especially
where the insurance company must have contemplated such
use of the engine. This is the holding of the Maine Supreme
Judicial Court in the case of Bouchard vs. Dirigo Mutual Fire
Insurance Co., 92 "Atlantic Reporter," 899. It appears that
the defendant company issued to the plaintiff a policy contain-
ing the clause quoted, covering a farm house and barn, and
denied liability for a loss because it resulted from using a
gasoline engine in driving threshing machinery. But the
court held that such use must have been contemplated when
the policy was issued, and that the clause mentioned must
be construed as applying to some permanent condition in-
creasing the flre risk, and not to mere temporary use of a
gasoline engine.
Responsibility for Employee's Negligence — The owner of
a power plant is not liable for injury to a boiler company's
inspector, resulting from negligence of an engineer employed
by the owner, if, in undertaking to assist in the inspection,
the engineer exceeded his authority. This, in effect, is the
decision of the Illinois Supreme Court lately announced in
the case of Johanson vs. Wm. Johnston Printing Co., 104
"Northeastern Reporter," 1046. The evidence showed that
the boiler company was employed to inspect the boiler, which
had been leaking, and sent the plaintiff to do the work. He
went into the combustion chamber of the boiler, the fire having
been drawn, and was scalded through leaking of hot water
upon him. In his suit to recover for the injury, he relied
upon the engineer's negligent failure to remain near the
boiler as he had promised to do. The Supreme Court disposed
of the case in the defendant's favor on the ground that the
engineer was not authorized to assist in the inspection, and
acted beyond the scope of his duties in so doing. The court
said: "Outside of the scope of his employment, the servant
is as much a stranger to the master as any third person, and
an act of the servant not done in the execution of services
for which he was engaged cannot be regarded as the act
of the master."
'0.
Make Dinkcl Steam Trap — We are informed by the Schiitte
& Koerting Co., Twelfth and Thompson Streets, Philadelphia.
Penn., that they also manufacture the Dinkel steam trap, a
description of which was published on page 644 of the May
II issue.
At a Meeting of tbe \mpriean Physical Society, Prof. C. \\
Chamberlain, of Denison University, Granville, Ohio, presented
and demonstrated his compound interferometer, by which it
is possible to measure 0.00000005 of an inch. It is next to im-
possible for the human mind to conceive the minuteness of a
measurement of this kind. It is equal to the apparent size
of the head of an ordinary pin viewed at a distance of 227 mi.
or the size of a silver dollar viewed at a distance of 9000 miles.
— "American Machinist."
C96
P 0 W B R
Vol. 41, Xo. 23
The Association of Iron <ft Steel Electrical Engineers will
hold its annual convention at the Hotel Statler, Detroit, Mich.,
Sept. 8-11. Suggestions regarding arrangements and inquiries
regarding accommodations should be addressed to A. H.
Swartz, Chairman Convention Committee, Churchill Ave.,
Cleveland, Ohio.
The American Society of Civil Engineers has adopted reso-
lutions providing that its representatives shall confer with
the Federal authorities on the plan by which a reserve corps
of army engineers shall be developed from its membership.
The resolutions state that these men are not only seasoned
in all lines of organization and constructive work, but are
also closely in touch with the best workers from whom the
rank and file of all branches of military service can be drawn.
A committee has been appointed to take up with the TVar De-
partment the plan of organizing this corps.
International Engineering Congress — The materials of en-
gineering construction will receive special attention in the
proceedings and discussions of the International Engineering
Congress to be held in San Francisco, Sept. 20-25. The field
will be treated under 18 or more topics, covering: Timber
resources: preservative methods; brick and clay products in
general; life of concrete structures; aggregates for concrete;
waterproofing; volume changes in concrete; world's supply of
iron; life of iron and steel structures; special steels; status of
copper and world's supply; alloys; aluminum; testing of
metals, of full-sized members, and of structures. These
papers, with discussiens, will be published as Volume 5 of
the "Transactions," and will be illustrated. For full particu-
lars apply to W. A. Cattell, secretary, 417 Foxcroft Building,
San Francisco, Calif.
HEW FUBILICATHOMS
MATERIALS OF MACHINES — By Albert W. Smith, Director
of Sibley College, Cornell University. Published by John
Wiley & Sons, Inc.. New York. Size, 5x7 in.; 215 pages;
36 diagrams. Price, $1.25.
In the second edition, which has been entirely rewritten
and considerably enlarged. Professor Smith's little book gives
an elementary view of the manufacture and properties of iron,
steel, copper, lead, tin, zinc, aluminum and the brass and
bronze alloys. The first part of the book gives a brief out-
line of the metallurgy of the materials. It also takes up
fuel combustion, the types of electric furnaces and the re-
fractory materials used in lining metallurgical furnaces. The
second part relates to chemical and mechanical properties,
and includes chapters on testing materials, on the heat treat-
ment of steel, and on brass and bronze alloys. The book is
self-contained and the reader need not consult chemistries,
metallurgies and works on strength of materials in order to
use the information.
VOCATIONAL MATHEMATICS— Bv William H. Dooley, Prin-
cipal of Technical High School, Fall River, Mass. Pub-
lished by D. C. Heath & Co., New York. Size, 5x7 in.; 341
pages; illustrated. Price, $1.
The author has prepared this book for use in vocational
schools, in which it is necessary to impress students with the
direct application of their mathematical knowledge to trade
and industry. After a review of the essentials of arithmetic
and mensuration, problems peculiar to the carpenter, plumber,
steam engineer, electrician, machinist and to the sheet-metal
and textile worker are presented. To illustrate the method
followed, the chapter devoted to engines contains an illus-
trated description of simple vertical and horizontal engines,
of the indicator, methods of calculating horsepower, mean
effective pressure from indicator cards, flywheel weight,
steam lap and size of supply pipes. Of course, the deriva-
tion of the formulas is not given, but their application and
problems relating to them are given. Much of the technical
information has no bearing on mathematics, and in addition
is not always correct. Such errors as the expression of latent
heat in degrees and the labeling of a series as a parallel cir-
cuit should have been avoided.
PUBLICATIONS OF THE BUREAU OF MINES
Bulletin 88: The Condensation of Gasoline from Natural
Gas. By G. A. Burrell, F. M. Seibert, and G. G. Oberfell; 1915;
106 pp., 6 pis., 18 Figs.
Technical Paper 101: Permissible Explosion-Proof Elec-
tric Motors for Mines; Conditions of Tests and Requirements
for Test and Approval. By H. H. Clark; 1915; 17 pp., 2 pis.,
1 Fig.
A limited supply of these papers is available for dis-
tribution to those interested. They should be ordered by
number and title from the Director of the Bureau of Mines,
Washington, D. C.
TRADE CATAIL0QS
Dodge Sales and Engineering Co.. Mishawaka, Ind. Cata-
log. Gearing. Illustrated, 126 pp., 6x9 in.
B. F. Sturtevant Co., Hyde Park, Boston, Mass. Bulletin
No. 218. Vertical engines. Illustrated. 16 pp.. 6^x9 in.
Yarnall-Waring Co., Chestnut Hill. Philadelphia, Penn. Bul-
letin C. A. Simplex-Caskey valves for hydraulic service. Il-
lustrated, 4 pp., 6x9 in.
Link-Belt Co., Philadelphia, Penn. Book No. 210. Wagon
and truck loaders for handling coal, coke, stone, sand, etc.
Illustrated, 48 pp., 6x9 in.
SKF Ball Bearing Co., 50 Church St., New York. Bulletin
No. 25. SKF Ball bearings in machine tools and shop
equipments. Illustrated, 68 pp.. 6x9 in.
Smooth-On Mfg. Co., 572-74 Communipaw Ave., Jersey City.
N. J. Pamphlet No. 4. Smooth-On Iron Cement No. 7 for
water-proofing brick ad concrete construction. Illustrated, 4
pp., *5x9 in.
The Jeffrey Mfg. Co.. Columbus, Ohio. Bulletin No. 165.
Wagon and truck loaders for sand, gravel, etc. Illustrated.
16 pp., 6x9 in. Bulletin No. 166. Wagon and truck loaders
for bituminous and anthracite coal. Illustrated, 24 pp., 6x9
BUSEHE^
The American Pin Co., of Water-bury, Conn., has recently
ordered from the Builders Iron Foundry, Providence, R. I.,
one large meter tube for boiler feed service. The Imperial
Tobacco Co., of Montreal, Canada., has also ordered a 2-in.
meter tube for the same service.
The Cooling Tower Co., with headquarters at No. 50 Broad
St., New York, has been incorporated to handle the growing
demand for the well-known "Mitchell-Tappen" cooling towers,
the patents on which are now controlled by the new company,
which also has additional patents pending. The operations
of the company will not be confined to cooling towers alone
but where the purchasers' manufacturing conditions warrant
it the new company is prepared to design and install spray-
nozzle systems and other cooling devices for the economical
re-cooling of liquids from all forms of condensing, refrigerat-
ing, smelting or gas engine plants.
■vord. minimum charge 50c
vice Examinations). Employ
tlon, in advance
: Agencies (Labor
Positions Open. (Civil
Bureaus). Business Op port unities, \\ anted i Atunts and Salesmen — Contract
Work). Miscellaneous .Educational — Books). For Sale. 5 cents a word, mini-
mum charge. SI. 00 an insertion.
Copy should reach us not later than in A.M. Tuesday lor ensuing week's Issue I
Answers addressed to our care. Tenth Ave. at Thirty-sKth Street. New York or §
1144 Monadnock Block, Chicago will be forwarded (excepting circulars or I
similar literature). f
Xo Information given by us regarding keyed advertiser's name or address. §
Original letters of recommendation or other papers of value should not be In- =
closed to unknown correspondents. Bend copies. |
Advertisements calling for bids, S3. 60 an inch per insertion. P 1
F©S1TD©M§ OFEH
MAN to sell heavily advertised power-plant specialties in
New York; must have knowledge of power-plant equipment;
an engineer will be considered; position permanent to right
man with old-established house. Write full particulars, giv-
ing salary desired and past connections. P. 518, Power.
F©§STIOH§ WAHTED
ENGINEER, experienced in alternating and direct motors
and generators, engines, turbines and ice machines; A-l ref-
erences. P. W. 521, Power.
CHIEF ENGINEER, employed in central station; seven
years' experience with engines, turbines, dynamos, boilers;
married; age 30. P. W. 511, Power, Chicago.
TECHNICAL GRADUATE, Middle West university, me-
chanical engineering, two years' practical experience, desires
position with progressive firm. P. W. 524, Power.
MASTER MECHANIC. 2S, twelve years- experience with
steam engines (all types), boilers and general machinery;
knowledge of theory and practice in mechanical and electrical
engineering: excellent references. P. W. 514, Power.
A CAPABLE ENGINEER at present employed as chief en-
gineer in a modern plant desires change where opportunity
for further advancement is greater; can furnish references as
to character, ability, etc. P. W. 512, Power.
CHIEF ENGINEER, technical education, broad experience,
energetic, successful in handling plants and men, open for
engagement July 1; desires responsible position; best of ref-
erences as to ability and character; age 42. P. W. 522, Power.
POWER
'rm' '
NEW YORK, JUNK 15, L915
^
No. 24
(Suggested by Wilbur R. Smith, Alton. III.)
Prism TSuaU Refracts
POWER
Vol. 41, No. 21
•oiler Plaimt of thu
turner CoaH
P.v \Vai;i;kn ( >. Rogers
SYNOPSIS — Six 72-in. return-tubular boilers are
installed in pairs, with but one combustion cham-
ber and one stoker for inch pair. The fuel used
is unsalable bone containing from SO to ifi per d nt.
of noncombustihh and averaging from 8000 to
11,000 B.t.u. per pound as /
A practice that will attract the attention of engineers
is the burning of high-grade coal in the furnaces of
coal-mining boiler plants. An instance where this is
not done is at the power plant of the Bessemer Coal &
Coke Co., Eussellton. Penn., where a grade of fuel for
which there is no market is burned with the aid of me-
chanical stokers, cadi feeding a common furnace for
two return-tubular boilers.
The mines are about eighteen miles northeast of Pitts-
burgh, on the Bessemer & Lake Erie E.R. The main
boiler plant consists of eight return-tubular boilers, ',2
in. in diameter and 18 ft. long, each rated at 150 hp.
Six are in one boiler house and two in another. The
sis were originally hand fired, the furnaces being sup-
plied with steam jets to assist in the combustion. The
other two were equipped with mechanical stokers sup-
plemented by steam jets, with the idea of burning the
bone which came from the mine. The arrangement did
not prove satisfactory in operation, because of the high
percentage of noncombustible in the fuel, so the furnaces
were all burning the best slack and %-in. nut coal, worth
$1 a ton at the mine.
Superintendent of Mines J. (i. Bart believed that low-
grade fuel could be burned if a properly designed stoker
were installed. An unusual condition exists in this mine.
Fig. 2.
Piece of Bone, the Bright Streaks
Being Coal
There are two seams of coal about 3^ ft. thick and be-
tween them is a binder of bone composed of layers of
slate and thin strata of coal. This is shown in Fig. 1.
A piece of bone that was taken from a car of fuel is
shown in Fig. 2 about one-half size. The bright streaks
are the layers of coal, the dark portion being bone. Be-
fore the machine was put to work removing the bone,
the latter was placed to one side by the miners and at
convenient periods was hoisted to the surface and hauled
away. The production was about 60 carloads a month,
Fig. 1. Cutting Machine Removing the Bone Binder from Between the Two Seams of Coal
Juue L5, 1915
POWER
799
ami the cost of its removal, with an average haulage
charge of about $6 a ear, was not far from $360 a month,
or $1320 a year. This bone has a heat value of between
8000 to 11,000 B.t.u. as delivered to the furnaces and
an ash content of between 30 and tO per cent.
To save the 100 tons of marketable coal that was
burned each 24 hours under the eight boilers, to cut
the cost of hauling away the bone and at the same time
tn reduce the boiler-room labor charges kept Superin-
tendent Bart on the trail of a stoker that would till the
requirements.
About two years ago the work of installing a Taylor
three-retort, underfeed stoker under each pair of boilers, or
three stokers for the six boilers in the larger room, was
H
li-flrtB?
fetiy''
Fig. 3. A Thkee-Betokt Underfeed Stoker Serving
Two 72-In. Return-Tubular Boilers
begun. A single boiler would require a two-retort stoker
and by placing two boilers over one three-retort stoker
the initial cost was lessened and the efficiency was not
reduced. Since the installing of the stokers, the boilers
have been operated at 175 to 200 per cent, rating.
Fig. 3 is a view of the boiler room, showing the stokers
placed with their center lines midway between the two
boiler units. Fig. 4 shows the stokers from the rear
end of the boiler setting.
The boilers are hung in pairs from steel railroad
rails weighing 100 lb. per yard. The shells are separ-
ated 6 in., and the space between is filled with plastic
cement. Fig. 5 gives a general idea id' the method of
placing the boilers. Each setting is IS ft. 6 in. wide,
with the boilers 6 ft. 6 in. center to center. The stokers
are each 6 ft. %%/% in. wide and extend under the boilers
9 ft. 9!/o in. They are operated by the fan blower.
Fig. 6. From the top tuyeres to the boiler shells the
distance is 3 ft. 0 in., and the top of the bridge-wall
is 1 ft. from the bottom of the shells. The combustion
chamber back of the bridge-wall is 11 ft. 9 in. wide
and 12 ft. 9 in. long, with a height of 5 ft. ti in.
Forced draft is obtained from an 8xl0-in. engine-
driven 9-i't. fan blower running at 320 r.p.m., which de-
livers air to a main duct 5 sq.ft. in area, running along
the rear end of the boilers, and from which two branches,
each 18 in. square, are taken to each stoker. These
branches join to a wind box below the stoker. An
air pressure of from % to % in. of water is maintained
Fig. 4.
Furnace ami Stoker Serving Two
Return-Tubular Boilers
in the box under the stokers. Fig. 0 shows the general
arrangement of the boiler, fan and air ducts and ash-
disposal trench.
The bone fuel now used with the stokers is removed
from the mine after being cut out from between the
two seams of coal, and is hoisted to the surface, clumped
into a single-roll crusher and then discharged to a dou-
ble-roll crusher, which delivers it to a belt conveyor in
Fig. 5. Plan of Boilers, Ami Trench and Air Di & a -
sizes not larger than l'^-in. It is then carried to an
overhead bunker having a eapafcity of ■;:,{) tons, or about
two days' supply.
It is interesting to note tli.it under former operating
conditions eight boilers were required to carry the load,
and about 100 tons of marketable coal was burned each
24 hours; the boiler-r Q force consisted of 10 men,
five to each 12-hour shift, and it was difficult to keep
300
POWER
Vol. 41, No. 2i
K~.?-J->K--*--3->j
HALF SECTION B-B HALF SECTION A-A
FRONT ELEVATION D"D
Fig. <;. Details of the Boiler Setting. Air Ducts and Ash Trench
Fig. 7. General View of the Power Plant of the Bessemer Coal & Coke Co.
June 15, 1915
POWER
801
them owing to the hard firing conditions. The six boil-
ers with their stokers now carry a heavier load than
before the change, owing to the increased outpirf of the
mine and the substituting of an electric haulage sys-
tem in place of mules. The boilers total 900-hp. normal
rating, but have frequently delivered from HiOO to 1800
hp. with but three men on a shift, or six men for the
'.' I hours.
One hundred dollars' worth of marketable fuel is saved
a day, ami refuse that formerly cost about $(i a car to
Fig. 8. The Two Generating Units
remove for filling-in purposes is for the most part burned
in the boiler furnaces, ami the removal cost of between
$300 and $100 per month is saved.
An interesting method of disposing of the ashes has
been worked out. They are flushed from the ashpit by
a 10-in. stream of drainage water pumped from the mine.
In front of the boiler a trench has been constructed,
as shown in Figs. ."> and 6, 24 in. wide at the bottom,
but with a shelf .'! ft. 0 in. wide at the top, making a
total width of 5 ft. 6 in. The extreme depth of the
trench is 3 ft. G in. The purpose of the shelf is to give
an additional water head for flushing out the ashes.
The ashes are shoveled into the trench, which is below
the level of the ashpit. A gate is provided at each
boiler and when ashes are to be removed the last gate
is closed until a head of water is obtained, when it is
opened and the velocity of the escaping water carries the
ashes with it. The plant is located at a considerable
elevation and the trench discharges at the edge of the
hill where there is sufficient ground to take care of the
ashes for years to come.
The boilers are fed under normal c litions through
a top connection, hut in case of an emergency they may
be fed through the blowoff. Each boiler connection to
the header is provided with a nonreturn valve and the
l''-in. header is likewise protected. A steam pressure
of loo lb. is maintained by the automatic speed control
on the blower engine.
A general view of the plant from the railroad side is
shown in Fig. 7. The three 45-ft. stacks serve the six
boilers, and the two taller stacks the other two. At
the extreme left is the engine room, which contains
two units: One a 500-hp>, four-valve engine directly
connected to a 300-kw.j 550-voM, direct-current genera-
tor at 150 r.p.m.; the other a 300-hp. engine directly
connected to a 200-kwv, 5.50-volt, direct-current gener-
ator at 180 r.p.m. The hoisting engine is in another
engine room; it has a 26x3ii-in. cylinder and operates
a hoist 260 ft. deep at a rate, @f LTQ cars per hour, with
an average of two tons per car.
A lOxlO-in. engine directly connected to a 40-kw., 220-
volt, direct-current generator is used for town lighting,
and as it is in the hoist-engine room, requires no special
attention.
The plant has attracted considerable attention because
of several novel features, but chiefly because of the burn-
ing of a fuel that it had previously been impossible to
use in a boiler furnace.
28
Bodice Safety §©af=OalSimg ClhaSclh
An improved solid multiple-disk friction clutch that
retains all the good points of the present clutch, with
the addition of the important features of safety, effi-
ciency and durability, has been developed by the Dodge
Manufacturing Co., Mishawaka, Ind.
All moving parts of the mechanism of this new clutch.
illustrated herewith, are concealed, making a smooth
contour, so that there are no projecting moving parts.
The design of the multiple friction disks, combined with
the new roller toggle-operating mechanism, makes it a
powerful clutch for its size.
The rolls on the toggle levers travel on conical surfaces
arranged to give high pressure on the friction disks with
a minimum amount of mechanism friction. The use of
rollers in place of sliding parts makes the device easy
to operate. The action of centrifugal force tends to
keep the clutch disengaged when thrown out.
The apparatus is self-lubricating. An oil ring, re-
volving in a large chamber, or oil reservoir, carries a
continuous supply of lubricant, which is circulated
Semisectional View of the Dodge Safety
Self-Oiling Clutch
through suitable grooves to all parts of the sleeve carry-
ing the pulley. This chamber is sealed to prevent oil
working out into the mechanism. The shifter ring for
engaging the clutch is made with a channel section that
retains oil and assures lubrication at this point.
The clutch can be easily adjusted with a single nut ad-
justment that is simple and positive. Backing off this
nut permits of the removal of the operating cone; this
exposes the toggle mechanism and allows the removal
of the inside mechanism for repairs. The best materials
are used throughout.
The device may be easily applied to stationary or
portable tools or countershafts, as well as pulleys, gears,
sprockets, etc., ami is especially suitable for high speeds.
:«
Pasadena Kleetrie Kates — Electric consumers in Pasadena,
Calif., had to pay 15c. maximum per kw.-hr. up to 190S, when
the city erected its own plant. The private company began
its fight against the city by a reduction to 12%c. The city
began operations with an 8c. rate; the private company met
it. In 1910 the city made its lighting price 5c. maximum with
a wholesale rate of 3c. and a power schedule of from 4c. to
less than lc. It is estimated that the saving to i the city has
been $100,000 per year since the plant was established. In
1913 the private company tried to put the Pasadena plant out
of business by making its maximum rate 4c. in Pasadena,
while it charged surrounding towns with no public plants at
6%c. to 10c. The State Legislature prohibited the company
from making the other towns bear the losses of the company
in Pasadena. — New York "American."
802
P (.) \Y E B
Vol. 41, No. 24
Ktttiimg Capacity im tilhi<
jFH<@©2Te
By A. (i. Solomon
SYNOPSIS — Is the plant that you have spent so
much time on this spring giving its rated capacity?
Is the condenser handling the gas as it should?
Is the gas going to the compressor at the proper
density and pressure, or is it superheated far more
than is unavoidable? Can yon add more load?
These questions are well considered in this article.
During the next six months there are several questions
which the engineer will ask himself: Is the full tounage
being got out of the plant ? Are the ammonia compressors
handling the amount of gas they should? Is the gas
going to the compressors at the proper density and terh-
verature? Are the direct-expansioD coils handled prop-
erly? Are the brine and ice tanks handled right? Are
the ammonia condensers doing their share of the work?
Is the ice machine big enough to do the work demand. Id ?
Can a little more load be added ?
The main question is to get the full capacity when it is
needed. One part of the system may be holding all the
other parts back.
Usually, the compressor is the first part considered
and blamed when the temperature of the coolers and
freezers begins to increase. In most cases putting the
blame on the compressor is not justified. There is not
much that can go wrong with the compressor. Leaky
valves and pistons may happen, but are not likely except
from long service. If the valves are ground in once a
year and the cylinders and pistons examined and put in
good condition at the same time, they will remain tight
during a season's run.
Scale and dirt from the pipework may cut cylinders
and valves, but there is little excuse for this. There are
scale traps (or should be) on the suction lines to the
compressors, and if they are cleaned at regular intervals
the scale will be caught. All new pipe intended for am-
monia systems should first be hammered and scraped
to remove the scale. With reasonable care the compressor
should give little trouble.
Condition of the Ammonia
So this really puts the success or failure of the plant
on the manner in which the ammonia is handled. First.
we will have to be sure that it is really anhydrous am-
monia that we have in the system. There are two things
that may be circulating in the system and taking up room
and not giving good results. They are noncondensihle
gases and moisture. The so-called air is the most common
and manifest- itself as follows: Increased condenser
pressure and consequently increased bark pressure: frost
melting from the machine and from the suction line;
whistling sounds at the expansion valves; high discharge
temperature and warm liquid lines and receiver. Some-
times, an insufficient charge of ammonia is taken as a sign
of air in the system. The symptoms are somewhat the
same. There should be a glass gage on the liquid receiver,
and this should show at least half full when the machine
is running on its proper load. If the liquid gets low in
the receiver, the gas is allowed to enter the liquid line
and then passes on to the evaporating coils, the compressor
and condenser.
It goes through the evaporating coils, and instead of
taking up heat by being vaporized it simply becomes sup-
erheated. The heat taken up by this gas is as nothing
in comparison to that absorbed by the liquid, but the
power required to pump it is about the same. So,
before purging the system of air, put in enough ammonia
to fill the receiver at least half full. Then, if there are
indications of air, purge the condensers. Do not expect
to get all the air out at one purging, but keep at it once
a day till it is gone.
Moisture is sometimes allowed to remain in the system
from careless handling during the steaming out of the
evaporating coils. This does not often happen and sel-
dom is the cause of' serious trouble. Moisture in the sys-
tem willin time show up in the oil traps and in the dis-
charge-gas receiver. It will look like dirty water and
is often called dead ammonia. No matter how full of
ammonia this water is, it has no place in the system if it
lies in the bottom of the gas receiver or oil trap. If there
is an ammonia regenerator or purifier in the plant, the
good ammonia can be boiled out and the moisture drawn
off. But if there is no purifier, throw the dead stuff into
tlie sewer. Noncondensible gases and moisture should
not be troublesome in the plant, for they are easily go!
rid of.
II wdi.ixg the Expansion Valves
Every engineer who operates a refrigerating plant is
sure that he knows just how to handle the expansion valves
to get the best results. It is a simple matter to open an
expansion valve when a coil in a warm room is to be
frosted.
We will assume that the cooler temperature has in-
creased to 55 deg. The direct-expansion coils are either
in a pipe deck above or else in the cooler itself. These
coils arc all free of frost. The proper way to begin
to refrigerate this room will be to put on one coil and
let it take up the steam and moisture from the atmos-
phere. This coil will frost quickly and will clear the
room of steam. When frosted all the way to the return
it should be shut off and another one put on. Do not
open the expansion valves on all the coils at the beginning.
This method of handling is to be recommended for two
reasons. First, it will keep the coils more free from heavy
frost and will give at least one clean coil to finish with.
The coils that are used at first will be clean again, as the
frost "ii them will be light, although thick, and will melt
quickly.
The other reason is not jso often considered, as its effect
is not so plainly seen. We know that the ammonia that
is in the coils when the room is hot is in a superheated
state. The temperature of this gas will be the same as
the temperature of the room. This gas will have to go
through the ammonia compressor on its way to the con-
denser. The capacity of the compressor is rated by the
June 15, 1915
I* o\Y E i;
80:;
weight of ammonia which it handles. The gas i- light
and occupies more space than a saturated vapor of tin1
same weight. J I' this superheated gas is all sent to the
compressor at once it will (for a time varying from fif-
teen minutes to one hour) greatly reduce the capacities
of the compressor and the condenser.
To get an idea of how much difference there is in the
space taken up by saturated vapor and superheated gas
we have only to look at the ammonia tallies. At 1 5.61! in.
pressure one pound of saturated vapor will occupy about '■>
cu.ft., while a pound id' gas at a temperature of 55 deg.
under the same pressure will oo upy about 1 1 cu.ft. This
superheated gas coming from the coils in the warm rooms
will meet the saturated vapor from the coils in the
cold room- and cause superheating of the ammonia pass-
ing through the suction line on its way to the compressor.
Tf a wet or humid gas machine is used, a greater
amount of liquid injection will have to he admitted dur-
ing this time to keep the cylinder cool. If the compressor
depends on a water jacket for the removal of the heat of
compression, the gas will become more superheated on its
admission to the cylinder. The temperature of this gas
often reaches !.">(> deg. at the end id' the suction stroke.
No matter which way it is looked at, there is a distinct
loss in refrigerating capacity when the warm cooler i-
first put on. By frosting one coil at a time and, by so
doing, sending the hot lnis to the machine in small quan-
tities, the loss will not he so great. Another good plan
to follow is to shut the expansion valves on all the coils
in the rooms having a temperature below 32 deg., while
getting the coils in the hot room frosted. These coils
will then pump down and give up whatever ammonia is
in them. This will give a greater amount of liquid to be
circulated through the hot coils, and when they are first
put on they will he able to evaporate more than when they
become frosted. We know that the expansion valves can
be opened much wider on a hot coil than on a cold one,
as the greater temperature and amount, of heat will evap-
orate much more ammonia. But do not forget that as
the temperature of the room is lowered, the amount of am-
monia fed to the coils must he decreased. I f the expansion
valves are left as first set, the ammonia will soon go to the
compressor in a liquid state. This liquid will, by re-
expansion, cut down on the capacity of the compressor.
The condition of the ammonia reaching the compressor
should lie regulated by means of observation of a ther-
mometer in the suction line. The closer this temperature
is to the temperature of the saturated vapor at the pres-
sure shown on the back-pressure gage, the greater will he
the weight of ammonia handled by the compressor at a
given speed.
Pipe Insulation
Superheating the ammonia by allowing heat to he ab-
sorbed through uncovered suction lines is a direct loss. A
good rule to follow in a refrigerating plant is: Any pipe
or apparatus which contains ammonia and is not used in
the absorption of heat or the giving up of heat should hi'
well insulated. This mean- to cover everything except the
evaporating coils and the condensers. But the discharge
tine from the compressor to the condenser need not be
covered, as the surrounding air will help to take away
the heat caused by compression. The ammonia liquid
line need not he covered ill slleh places where the tempi i
ture of the rooms through which it passes is lower than
the ammonia in the pipe. Do no! allow an uncovered
liquid line or a liquid receiver in a place where the tem-
perature i- higher than the condensing water used on the
ammonia condenser.
The am da goes to the condenser to give up the
heat it collected while evaporation was taking place.
Here, we sei' the loss in condenser capacity caused by sup-
erheat. The gas must first he reduced in temperature
to that of the saturated vapor at the condenser pressure
before liquefaction takes plan'. So some of the condensing
surface IS Used in taking away this superheat instead of
liquefying ami cooling the ammonia. After the ammonia
is liquefied it should he cooled to the temperature of the
coldest water available. Most plants use a cooling tower
and reservoir and have a we]] 0r city-water line for mak-
ing up what water is used or lost by wind and evaporation.
This makeup water is, as a rule, much colder than the res-
ervoir water and should he used for cooling the liquid
before it is allowed to mix with the reservoir water.
Tli- even distribution of water on the condenser is
also necessary. Do not have soi oils flooded while
others are nearly dry. Have every foot of pipe doing its
-hare of the work. Small leaks must he attended to just
us soon a- tiny are found, as they are generally the
sources of 1,,-- of the ammonia. The big leak- are
fixed at oiic. and the -mall ones should receive the
same strict attention.
aa m.mh>~S&<s<sF° Psunnap Vsviv©
This pump-valve disk i< a combination of rubber and
steel. It consists of a steel plate placed in the center of
the valve with a rubber composition on each side and
edge; the rubber is attached to the metal by a chemical
process. Tin- plate embedded in the rubber is shown in
the illustration. It- objeci i- to give snch strength to the
valve that the pressures against which it works cannot
Reinforced Rdbbeb Pump V ilve
warp, twi-t or in any way get it out of shape. The
rubber surfaces afford the proper seating qualities.
On account of the rigid reinforcement, the valve is
kept in it- true shape, high pressure i- prevented from
forcing the valve through the wch of the vahe seat and
dishing of the valve is avoided.
The "Rub-Steel" valve disk is manufactured by the
Voorhees Rubber Manufacturing Co.. 18-50 Bostwick
Ave.. Jersey City, X. .1.
S04
row e i;
Vol. 41, No. 24
>pers\tti©ini s^midl Desngmi
By Norman <;. Meade
SYNOPSIS — The uses of auto-transfoi
some of the corresponding connections; also the
culi illations anil directions for constructing one of
10-kw. capacity.
The most common use for auto-transformers is the
starting of induction motors, to supply a gradually in-
creasing voltage as the motor accelerates. Other applica-
tions are balancing coils for three-wire distribution sys-
tems and three-wire direct-current generators, single-
phase railway systems, and for general service where the
ratio of transformation is not large.
There is only one winding per phase, serving as both
primary and secondary, as is shown by the circuits of a
single-phase auto-transformer in Fig. 1. Here the same
two auto-transformers, one connected to each phase of a
two-phase, four-wire circuit for starting a two-phase mo-
tor. Ordinarily, there are several taps in each auto-trans-
former connected to a controller to provide a gradually
ing roltage for starting.
Delta connections of a three-phase auto-transformer
are shown in Fig. i> and the Y -connections of a similar
auto-transformer in Fig. 7. Both of these arrangements
may be used for stepping up or stepping down the volt-
age.
Auto-transformers as applied to three-wire systems of
distribution are shown diagrammatically in Figs. 8 and 9.
In the former the auto-transformer is connected across a
220-volt line with the neutral tapped in at the center, giv-
ing 110 volts between each outside wire and the neutral
and 220 volts between the outside wires. In Fig. 9 the
FIG 7
Connections fob Auto-Transformi rs
fig. 9
Dumber of turns is required as in the primary of a two-
coil transformer of equivalent rating and where the ratio
of transformation is approximately 2 to 1 ; also the same
weight of copper as in the primary winding of such a
transformer. The voltage per turn is uniform through-
out the winding, and to secure a low-tension voltage of
55 when the high-tension voltage is 110, it is necessary
only to make a tap midway between the ends of the coil, as
shown.
To supply 1100 watts on the low-tension side requires
a current of 20 amp., but as this is opposed in time phase
relation to the high-tension current in this section, there
will be only 10 amp. flowing in the coil. Owing to ex-
cessive magnetic leakage when the windings are continu-
ous, as in Fig. 1, it is customary to make up the winding
of several interspaced coils as shown in Fig. 2.
Figs. 3, 4 and 5 represent, respectively, two V-con-
nected auto-transformers arranged for starting a three-
phase induction motor, three single-phase auto-trans-
formers, Y-connected, for starting a similar machine: and
auto-transformer is also designed for 220 volts, but is
connected to a 110-volt circuit from one end tap and the
center tap, giving the same voltages as in Fig. 8.
Design of Aijto-Tk\n:si-okm:ebs
Assume that it is desired to design an auto-transformer
of 10-kw. capacity for a 25-cycle. 440-volt circuit with a
2 to 1 ratio of transformation, the low-tension voltage
to be 220. Let it be of the core-type constitution with
two legs and let the winding be divided into eight coils,
four per leg. Assume the efficiency to be 95 per cent.
„„. . watts output
AtflCU'HCI/ = — ; -
■' J watts input
Then for an output of 10.000 watts the input will be
10,000 -^ 0.95 = 10,526 jsatts.
This limits the total full load loss to 526 watts, which
should be about equally divided between the core losses
and the copper loss, with perhaps a little greater coppei
loss. Therefore, let the copper loss be 300 watts and the
core loss 22G watts. Assume a magnetic density of 30,000
June 15, 1915
POWER
S05
lines per square inch of cross-sectional area of the core,
which is a fair value for 25-eycle circuits. Then from
eurves showing hysteresis loss it will be found that for a
density of 30,000 lines at 25 cycles, the loss is 0.1 watt
per cubic inch of core for a good quality of soft iron in
sheets.
The eddy-current loss will be small in a properly con-
structed cmv: hence it may be taken as 20 watts and the
hysteresis loss 200 watts. Then the volume of the iron
in the core will be 200 -^ 0.1 = 2000 cu.in. The plates
should lie from 16 to 20 mils in thickness for 25-cycle
circuits, and the oxide on the plates with a sheet of paper
placed about every half-inch should be sufficient insula-
tion. The volume of the iron core has now been deter-
mined, and it remains to proportion the core itself. Fig.
]0 shows the type of core selected, and in proportioning
it due regard must be given to the winding.
The core will be made square in cross-section, with the
cornels chamfered slightly. If the cross-section is made
\ri\ small, the cores will be long and thin, the magnetic
tlux N will he small, and the coils will have to be pro-
vided with a large number of turns to generate the re-
quired electromotive force. Long cores also give rise to
a long magnetic circuit, thus increasing the magnetizing
current. On the other hand, if the cores are made very
short the wire will have to be piled up deep in order to get
it into the winding space, and the yoke across the ends will
have to be made longer. Deep windings also mean a
greater length of wire for a given number of turns. The
best proportions are largely a matter of experience. For
preliminary dimensions let the proportions shown in Fig.
11) lie used, all of the dimensions being expressed in terms
of the thickness of the core. Make the height 7 a; the
volume of the core will then be
V = (2 > 3.5 a + 2 X 5a)a2
n- being the area of cross-section and 5a the distance
between the yoke.-. This gives
V = IT a3 — 200(1 cu.in.
« hence
a 12000
a = \ = 4.8'.i sq.in.
\ 1 1
This would represent the thickness of the core if it were
solid iron. Part of the cross-section, however, is taken
up by insulation between the plates, and the corners are
cut off slightly, so it will be well to make the core 5 in.
square. The other dimensions shown in Fig. 11 follow
from this.
The impressed electromotive force is equal and opposite
to the resultant of the counter electromotive force gener-
ated by the winding and that necessary to overcome the
resistance of the winding. The drop in the winding is
small compared with the impressed electromotive force
and for present purposes may be neglected, hence the coun-
ter electromotive force generated in the winding may be
taken as equal numerically to the impressed electromo-
tive force. The number of turns required to produce this
will depend upon the magnetic flux N which threads
through the windings. The maximum magnetic flux
through the winding will be JV = Bmax X a, where Bmax
is the maximum value which the magnetic density reaches
during a cycle, and a is the cross-sectional area of the
core. In this case Bmax is 30,000 lines per square inch,
and a is 25 sq.in. Therefore,
N - 30.000 X '-•""> = 750.000.
Taking the electromotive force generated in the wind-
ing as the equal and opposite to the line voltage,
_, 4.44 x xx rx f
E = - -To*-
where
N = Maximum value' of the magnetic tlux through
the core ;
T = Number of turns on primary coil ;
f= Frequency in cycles per second;
E = Impressed electromotive force.
Applying this to the presenl example.
4.44 X 750,000 X T X 25
440 =
T
440 X 10«
528
4.4 4 X 750,000 X 25
To make ample allowance let the number of turns be
600, or 300 to each leg. The current equals 10.000 -4-
*
17.5— -
— , >
h.
A
<— 5»_> <-|— 75? -!->
<-- S*->
*
Pll
10. Pic
Coke Dimensions
440 = 22.3 amp. Allowing 2000 circ.mils per ampere,
the size of the wire will be 44,600 circ.mils, which corre-
sponds nearest to No. 4 B. & S. gage. For this size
of wire there are 4.5 turns to the inch. Allowing for in-
sulation and space between coils, there will be approxi-
mately two layers on each leg. The approximate mean
diameter of the coil is 7.5 in. and the mean length of one
turn 23.5 in., say 25 in. The total length of the winding
will then be 600' X 25 -r- 12 = 1250 ft.
The resistance of No. 4 wire is approximately 0.25
ohm per thousand feet, which gives a resistance for the
winding of approximately O.'-'ri ohm. The PR loss equals
22. 32 X 0.32 = 159 watts. As the allowance for copper
loss was 300 watts, this is well within the safe limits, and
the efficiency will be greater than that assumed tenta-
tively in the beginning.
Construction of Auto-Transformers
Having decided upon the core type of construction and
determined the size of the core, the next step is to assemble
the sheets. A wooden form should be provided, con-
806
P 0 W E Ti
Vol. 41, No. 24
forming to the internal dimensions of the core, and this
should be laid on a level surface. Half of the iron sheets
for the sides will be cut as long as the height of this form
and half will be cut the overall height of the core. Sim-
then be heated to about. 200 deg. P. and immersed in
seme good insulating compound and baked.
Provide some rounded hardwood blocks that have been
thoroughly soaked in insulating compound and place them
..-.— flo/zis -------- --
b'«
•b
•l/'ll
Wood Form
°
?
FIG. 13
FI6.I4
FIG 12
FIG 15
FIG. 16
Winding Details and Coil Connections
ilarlv the ends will be made with half of the sheets as long
as the width of the form and the other half as long as the
overall width of the core.
Place two long strips, 6 and V (Fig. 12), against the
form and select two of the shorter end strips, a and a', and
place them at the ends of the form. Next lay on two
short strips 6 and 6' and two long strips a and a'. This
construction will give lapped joints. When the desired
thickness of iron has been built up in this manner, the
iron should be clamped, drilled and riveted, as indicated.
The bolts can be removed and the top yoke withdrawn,
leaving dovetailed connections for the top of the core.
The core is then ready for the assembling of the coils.
The next step is to provide a form for the coils similar
to that shown in Fig. 13. The distance between the col-
lars should conform with the height of the coil, with the
center slightly tapered to facilitate the removal of the
finished coil. There should be about four slots on the
circumference of each collar on the spool, in which pieces
of cord are laid before winding is started. These cords are
for binding the coil before removing it from the form.
Figs. 14 and 15 show, respectively, a partially completed
and a completed coil. Flexible leads are soldered to the
coil ends and insulated as shown. When the coil is wound,
place a strip of flexible micanite around the inner sur-
face and wrap with tape and cord at four places as
shown, after which the temporary tie cord can be removed
and the coil securely wrapped with webbing. It should
around the cores as shown in Fig. 16. Slip the coils
in position with mica washers between them and between
the top and bottom coils and the core. The coils should
then be connected as indicated in Fig. 20, a, b, c and d be-
ing connected together as are e, f, g and h, and the leads
joined as shown.
■Ml
Mail
i letter
>y Dep-
Wulhall,
'ail for
'lie let-
d were
r the
for
Ced-
ler
m.m- In 1909 o,r
,.i© law class of that ;
t testified that she and hex
.a had been living apart elnce
..-ember, 1914. Mrs. Deboalt was
represented In court by Attorneys
MacOmber and Pendleton.
Deboalt made no appearance and
was unrepresented by counsel.
«.
Trapped in Boiler
Amid Hissing Steam
- Andrew Monsen. a boiler cleaner, em-
ployed by the Equitable Light and
Power Company, who lives at 61 Cali-
fornia rtreet. narrowly escaped being
scalded to death In the basement of the
Phelan Building this afternoon. While
Monsen was working Inside the boiler,
the engineer, ne>( knowing that he was
inside, turned on the steam. Monsen
was taken unconscious to tfce Central
Emcgency Hosplta.
In.
as
Mi
of tl»
Joao
Min!^
roz.
Minis
Minis'
elra Qt-1
Minis'
MInlst
Montelrc
MInlst
Costa.
MInlst
Magalha
OAKL.
Ms sister,
eloped w.
residing .
today ai
the cou:
Safety First! A Locked Valve Would Have
Prevented Tins Aci mi \ i
June !•">. 1015
row eh
807
Hffimpir<D>v©sim<sinifts ana V^BJottcfei
In the Mar. 31, 1914, issue, page II"'. was illustrated
the Boppes V-notch meter in the original form. Since
then several improvements have been made. There are
many places in which the recorder had to be located
where there was considerable vibration, and this not only
Fig. 1.
Impkoved Weighed Ri i ohdeb ami
Recorder II i \ i >
made a wide mark on the chart, but in some instances
the integrator was bo interrupted as to make it. unre-
liable. To overcome these difficulties a much longer
and heavier guide ha- been designed which has overcome
the previous defects.
Figs. I and 2 show the changes made In addition to
improving the guide, the adjusting hand 0, Pig. 1, has
been changed to the bottom of the column for adjusting
the instrument to the zero level, which obviates the
necessity for changing the brass sleeve E. All that is
necessary now to adjust the zero level is to loosen the
screws K and turn the band 0 up or down until the
^^^VStfBB
^■■iST""^
jM ^F?
^k
11 J
TO
l i«^
*~i!PaJ
Fig. 2. Improved Eecordei; Head, Showing Chart
Side of the Instrument
water drops slightly from the pet -cock C. All of the
other adjustments have been made at the factory before
shipment.
The improved recorder head, Fig. 2, is also made,
Fig. 3.
Recorder Head Placed Below the Tank
and Cabinet
when desired, to be placed below, the cabinet L, as shown
in Fig. 3. This is a desirable feature where the meter
tank has to be placed at a considerable elevation above
the floor or on the floor above the room where it is de-
sired to have the recorder head. This illustration also
shows clearly the connection of the water behind the weir
with the weighing ressel, .1. Fig. 1. These improvements
add to the adaptability of the meter.
SOS
P 0 \Y E B
Vol. 41, No. 24
TO
npe wo
By W. Lee Eouec she*
eiKSinmig aim
SYNOPSIS— Welded pipe is being more and
ware use, I each year, and the progress of its
application is therefon oj interest to watch. The
relative cost oj welded and flanged steam header
favors the former. The article illustrates some in-
teresting examples of pipe welding and gives valu-
able results from destruction tests on welded pipe.
It i- only in the past decade thai the design and con-
struction of piping systems for power plants have received
the careful though! and study of designing engineers
which their importance warrants. Joints and massive fit-
tings have been a potential source of trouble and expense,
and a minimizing of their number is desired. The per-
lighter, therefore easier to erect and support. It is built
of the same material throughout and avoids the uncer-
tainties due to defective castings and unequal expansion
strains. The number of intermediate joints is reduced to
a minimum, and in many instances they arc cut out al-
together. It has been found practical to close the ends
Fig. 1. Section Showing Construction of
Welded Joint
Eecting of the oxyacetylene torch has made this pos-
sible and also has enabled better engineering.
The old-style header, built up with cumbersome flanged
fittings, is fast becoming obsolete. It is now practical to
build headers of the same relative strength as the pipe it-
self and in lengths limited only by shipping and erecting
facilities. The relative cost is in favor of the welded
header, more particularly in the larger sizes and where
there are a numher of outlets. A welded job is also much
•With Crane Co., at Birmingham. Ala.
Fig. 2. Welded Header, 18 In. Diameter; Total
Length 48 Ft. Note Outlets of Various Sizes
of headers with convex heads, dished to the proper radius
and welded on. thereby doing away with all joints except
those at the nozzle connections.
The usual method of construction is to take lap-welded
merchant steel pipe of the proper diameter and thickness
and where necessary weld together to get the desired
length. The holes for the outlets are cut either in the
usual manner or with the cutting torch. The nozzles are
then welded on after being shaped to fit the curvature of
the pipe. Different manufacturers have various methods
of attaching the nozzles. The method used by the writer.
which has proved to equal the strength of the pipe itself,
is shown in Fig. 1. The pipe is beveled so as to form an
angular groove of about 45 deg. with the nozzle. The
fillet is then built up to the proper thickness. Nozzles
of any size up to the diameter of the header itself
have been successfully used. All welds are annealed
after the header is completed, to relieve strains that may
have been produced during the welding process. The
Fig. 3. Large Steam Header, 31 Ft. Long; Rolled Steel Flanges and Seamless Nozzles
June 15, L91T
P O W E E
SO!)
Fig. (I (Above). Tex Lengths of 8-In. Pipe Each 40 Ft. Long
Fig. 7 ( Below). An 8-In. Header, 30 Ft. Long. Note Nozzles at Each End
810
r 0 \Y E R
Vol.41, No. 34
usual tesl is a cold-water pressure 2y2 times the working
- 1 ; re.
shows an l£ ader 48 it. over all, buili in
two sections, with six 7-in. boiler connections and five
distributing outlets ranging from 2 in. to 10 in. This
header was tested to 600 lb. hydraulic pressure and has
been in sua operation for more than two years.
Fig. 9. Five Coils Having Total of
li/o-Ix. Pipe
100 Ft. of
Fig. S.
Pipe Coil fob Ammonia Plant; Has 180 Ft.
of Pipe
Fig. 3 shows a 14-in. header 31 ft. 2 in. over all, with
four 8-in. and one 4-in. seamless steel nozzles.
Fig. J: is a good example of work that would have been
practically impossible without the welding torch. All the
headers are of ]4-in. o.d. pipe :;;* in. thick. The goose-
neck was originally made in four sections and then made
into two by welding. The location of the welds can be
clearly seen in the photograph. The whole was installed
in the same relative position as shown. The 14-in. outlet
on the middle header connected to the upper end of the
gooseneck. These headers were built to meet a peculiar
condition in a Southern plant and have been in service
about two year-.
Fig. 5 is a further example of the advantages of the
oxyacetylene weld. This is a special 8-in. expansion U-
bend made to suit special conditions. The weld can be
plainly seen at the top. just over the crane hook. The
finished bend contains 3? Ft. of pipe.
In long runs of pipe it is possible to eliminate from 40
to 50 per cent, of the joints. Fig. i> shows ten lengths of
8-in. pipe for a high-pressure steam line averaging over
10 ft. cadi.
Another g 1 example of a welded header is shown in
Fig. 7. This is an 8-in. header 30 ft. over all, with two
8-in., two 6-in. and two 5-in. seamless steel nozzles. The
8-in. and 5-in. nozzles are in the same plane set at 90
deg. to each other.
The possibilities of oyxacetylene welding in all classes
of pipe have only just bfgun to be realized. It is be-
ing successfully used in ammonia work, where there is
a wide field for it. Figs. 8 and !l are good specimens of
this class of work. The former is for a reboiler in an ab-
sorption plant. The coil is 19 in. outside diameter and
contains 180 ft. of l^-in. extra heavy pipe. Fig. 9
June !•">, 1915
PO W ER
811
shows a set of the same kind of coils which nest together, cession at hydraulic pressures of from 2100 to 2300 lb.
the five coils containing about L400 ft. of Li^-in. extra The hulls showed stress a1 2300 lb. One end of the
heavy pipe. These coils were tested l" 800 lb. hydraulic pipe was then cul oil' and a %-in. thick convex head butt-
pressure, welded oil. A special flange WHS made Tor the oilier cud
Destruction Tests of Welds and the bolts increased from twelve %-in. to twelve 1-
,,,, ., , i i , , , , , ■ ,. i,,„ in. Bvdraulic pressure was again applied. At 3300 lb. the
1 he writer lias made several destruction tests m order , . . . ., , ■ , , • , ,
,, ,, ,. , i i, -,| ,i | |- ,i flanged loin ill ed OWing lo I ii' dishing ol lie rolled-
lo compare the strength ol ihe weld wiih Unit, ol Uie p J p &
.,, , , i i ii n; ; >, „ r stee flange. Neither wed on examination showed any
pipe. These have proved conclusively the efficiency ol . s
,,ii , i i ii i:,. iii , ,; mi hea ion ol failure. Ihe theoretical bursting pressure
ihe weld when properly made. In ihe hr.-i test, a piece ,,.,.. , ,. ,
,. , . ■ e ii • i , '■ - I-, i I ,;, . 1 „.;n ol 6-m. II -Wo|e|| pipe, ils given hv the lllil II II I llel II 1'er, IS
ol P.'-in. full-weight pipe, .i Ii. Long and equipped with ; ■ , • ■ ,
, ... i ii i i i i • i i i a i \ I'HH) Ih., iind this test was made without annealing the
lap-joints and rolled-steel high hub flanges, was used. A » 6
i ,i i .mi., ,,,; i„. ,,. i„ welds. I was I on in Unit the oiit.-ide diameter ol the
l-lll. seamless sleel nozzle Was welded oil IllldwaV I"'- . ,
:, ,, , ,i iii ,.;n ,.i„, i pipe was increased almost h in. Ihe thud lest was
Iween the Halites, and the ends closed with extra hcaw It ; _ • , ,
ii- i n i ii i ii .innii ii I, i,.,,,i; made with a piece ol 5-in. lull-weight hip-weld merelniiil
cast-iron blind tlanges holled on. At 3000 lb. hydraulic ' ,,,,■, , ■ ,
pressure one of the blind flanges gave way, while the weld I abou1 ,; Ei 1"M- ^tt-welded ,n the middle as in the
.hewed no signs of stress; The second test was made seeond fest> an th ends closed Wl,h a 3/8"m- thlck
with a pice of 6-in. full-weigW pipe 5 ft. long. The convex head butt-welded on. AI 2700 lb. the seam oi the
pipe was cut in the middle and hull-welded with the I'M"' opened up. This was welded with the torch and
torch. The ends were title, I with lap-joiuls and rolled- hydraulic pressure again applied. Al 3950 lb. Ihe pipe
steel flanges and blanked with extra heavy cast-iron burst, rupturing the metal longitudinally to one side of
blind flanges. Three blind flanges were broken in sue- the seam where it had been rewelded with the torch.
^mtoinniaitie Electbric Comoro!
©f Primps
I'.y George J. Kjrchgasser
frequently below the level of the sewers and considerable
wider drains in after rains or thaws. A pit is usually
provided so that this water is collected in one place. A
small pump called a sump or bilge pump, usually driven
by a vertical motor, is used to prevent overflowing into
Probably the commonest type of motor-driven machine the basement. To automatically start and stop this pump
SYNOPSIS— An interesting description of the
applications of automatic electric control devices
for pumps in various kinds of service.
to which the automatic starter has been appli
th
so Unit there will he insurance against Hooding the base
pump. From the small house and sump pump to the incut and against useless waste of electric power, is one
Pig. I Fi«- "'
Control Devices for Direct- and Alternating- Current Motor-Driven Sump Pumps
largest types used on water systems, automatic or remote of the common applications of the motor starter, or
control has proved of distinct advantage. controller.
' Sump pumps are used to keep basements clear of The illustrations. Pigs. 1 and 2, show automatic con-
waler. The basement floors of buildings of today are trailers for direct-currenl and alternating-current motors.
SI -2
P 0 W E B
Vol. 41. No. 24
In the first the float switch is mounted so that its opera-
tion is easily explained. As the water in the pit rises,
the rod .1, mounted on a float, rises also. This rod has
two stops, one of which is shown. As the float and rod
rise, the lower stop engages the movable arm B of the
floal switch. When this moves through a certain distance
the weighted tumbler
arm ( ' of the switch
causes the latter to
close, and this in
turn causes the sole-
noid D of the starter
to become energized.
The motor is thus
started and acceler-
ated to normal run-
ning speed. Tin'
pump will be driven
until the water level
has been lowered to a
predetermined point.
When this is reached
the upper stop on the
rod will have tripped
the float switch open,
which causes the au-
tomatic starter to cut
the motor from the
line and thus bring
it to a stop. The
pump may he put in
operation for leu- or
short periods, it may lie started and stopped many times
a day or only a tew times a year, hut no attention is
required, and current will be used only when necessary
and for as short a period as required to lower the water
to the desired level.
Fig. '■'<. Th i: Float Switch
Pig. 4. The Float Switch of This Motor-Driven
Return Switch Is Actuated by the Water
Levee is the Pump Govebnou
For small sump-pump equipments operated by alter-
nating-current motors the magnetic switch shown in Fig.
2 is used to throw the motor across the line or to cut
ii off, as the water level demands. In this installation
the float switch, operated by the vertical rod . I . is mounted
on the post in hack of the automatic starting-switch panel,
one end of the lever alone being visible. Fig. 3 shows how
the sump float is arranged.
Fig. 1 shows a simple but interesting application in a
school building, of the same type of automatic switch
and float switch. The latter is mounted Dear the floor
(sec .1), while a magnetic -witch is mounted on the
wall and not shown in tins view. A J^-hp., three-phase,
60-cyele, 220-volt motor of the squirrel-cage induction
type is used. Back of the float switch is shown the
Equalizing
Fig.
Showing the Pump Governor
automatic pump regulator and condensation receiver used
in connection with the steam pump to automatically
return the condensation from the heating system or other
apparatus to the boiler. Fig. 5 shows such a receiving
apparatus tor returning condensation to the boiler, in
5IN6LE PHASE MOTOR
Fig. (i. Automatic Startee fob Single-Phase Motok
which an automatic pump regulator and condensation
receiver arc employed. As the water rises, the float is
raised and at a certain lev?l causes the tumbler arm o(
the float switch to close the magnetic switch and set the
motor and pump in motion. The float switch docs not
carry the motor current, hut simply the energizing cur-
rent which causes a magnetic switch (as in Fig. d) to
dose and conned the motor to the line. After the level
June 15, 1915
pow E 1;
813
drops, the float switch is tripped open and the tor
disconnected from i he line.
In the keeping of anj sorl of open lank filled to a
desired level the same methods of control may be used,
except that the float and float-switch operations are
opposite from those used in connection with the sump
: ■<-////////////.
_ ____^
THREE PHASE MOTOR
Fig.
Wiring of Automatic Staktbe for
Thkff-I'hasf Motor
primp. Tn the ordinary tank system the motor is started
and put in operation when the level is low and stopped
when it roaches a desired high point. The same kind
of float switch or an inclosed type may be employed.
Figs. <> and 1 show the wiring for automatic control of
single- and three-phase motors respectively.
Pumps or compressors operating on closed systems are
controlled in a similar way, the automatic starter being
actuated l>\ a pressure-regulated switch instead of a float
switch, as shown in Fig. 8.
House pumps are required in all buildings where the
city water pressure is not sufficient to supply the upper
floors. These pumps are not required at all times. Inn
mil;, when the demand made (in the system lowers the
pressure maintained. To do this in the mosl econ ical
AUTOMATIC MOTOR STARTER
WITH MAIN LINE KNIFE
\SM7
DIRECT CURRENT MOTOR
Pig. 8.
Wiring and Controls for Starter for
DlREI T ( luKRENT MOTOR
ami best way. automatic control of the starting and
stopping of the pumps is necessary. The pressure require-
ments are thus always maintained. Fig. '•> shows two of
three triplex house pumps in the Continental and Com-
mercial National Bank Building, Chicago. These pumps
are driven h\ 20-hp., 220-volt, direct-current motors
automatically started and stopped by the three automatic
FlG. '.». Two of TllKF.F ELECTRICALLY CONTROLLED HOUSE POMPS IX OFFICE BUILDING
First, one- is cut in, then if the demand increases, another is started, and so on until the demand is met
814
P 0 W E P,
Vol. 11, X«i. Z4
controllers shown on the panel. This equipmenl is
arranged so that when the tiist demands are made, one
motor is set in operation. II the demands of the service
are greater than can be cared lor by one pump, the
second one is put in service and the third also, should it
be needed. A pilot arrangement on the controller panels
makes it possible to have any one of the three put in
service first, followed by the others, thus dividing the
work equally lor a given period.
In the ease of the automatic fire-pump controller any
decrease in the pressure on the sprinkler system due to
opening of a sprinkler head or to valve leakage causes
the pump to he set in motion until the pressure supposed
to be maintained in the system is again reached.
Similar machines, as vacuum cleaners, compressors and
blowers, are also controlled automatically or by a push-
button switch closing the automatic starter solenoid or
magnetic circuit in the same way that a float switch or
pressure regulator does. In buildings tenanted by dentists
and physicians compressed air is usually furnished by
compressors located in the basement and automatically
controlled by pressure regulators and automatic motor
starters, to keep a suitable pressure on the system regard-
less of the demand.
S
The balanced throttle valve illustrated herewith has
been designed to operate with ease ami with efficiency,
combined with durability. When the valve is in place
the steam enters above the disk, otherwise the value of
the bypass is lost. With the valve closed pressure
the balancing cylinder past the piston ring and through
the drain bole in the bottom of the disk cylinder. As
a result, the pressure above the disk is equal to that in
the inlet of the valve. This pressure aids in keeping
the disk tightly scaled, and it is relieved by the b
7, the opening through which is covered by the bottom
of the stem when the valve i> closed. When the hand-
wheel is turned slightly, this opening is uncovered and
the steam above the piston passes through the hob's in
the retaining ring E. theme through the hole in the by-
pass disk and through the drill holes in the bottom of
tin' main-disk guide stem .V; this relieves the pressure
above tin' piston while the valve is being opened and
the arrangement prevents pressure above the disk during
tin- opening of the valve.
Th drain hole in the bottom of the disk cylinder is
to relieve the condensed steam that may accumulate in
the cylinder when the valve is connected in a vertical
position. When the valve is in a horizontal position the
water in the disk and in the balancing cylinders will
drain past the piston ring. Both the main and the by-
pass valves are operated simultaneously. Provision is
made for regrinding the seating surfaces of the main
seat and disk seating surface.
This valve is manufactured by the Lunkenheimer Co.,
Cincinnati, Ohio.
:s
LiUNKENHEIMEB BALANCED THROTTLE VALVE
\\\ Loe Add^
The operation of a portable engine is not a very angelic
occupation, and at times it would seem that there must be
a destiny to guard the operators from misfortune.
Upon one occasion, while overhauling a second-hand
sawmill outfit, a wooden connecting-rod was used as a
template for a new rod and was left on the engine when
the workmen left the mill on Saturday evening. The
next morning the owner, anxious to try his new engine.
got up steam, turned it mi and gave the flywheel a whirl.
The wooden connecting-rod broke and the crosshead drove
the stuffing-box gland through the cylinder head.
The engineer of a threshing out lit fed vinegar into the
i at the rate of about six gallons a day for several
day-. It was supposed to prevent the foaming of the
bad water taken from ponds and muddy copperas stream-.
The engineer said that the boiler needed blowing down,
but he had twisted off the stem of the blowoff valve.
Th boiler had not been washed out in weeks. Its inter-
nal condition can better be imagined than described.
The -peed iif the sawmill engine was controlled by a lev-
« i belted to one of the arms of the governor, from which
the belt wa- removed. A wire attached to the end of this
lever extended to a wooden lever within reach of the
sawyer, thus furnishing means for shutting off the steam.
When the wire was released the balls dropped by gravity,
giving a full head of steam. The lexer was secured by be-
ing hooked behind a nail ij» a post, to lie released when the
power was needed. It can readily be imagined about how
tive the control wa-. They certainly placed great
confidence in that wire and nail; for if the lever became
unhooked or the wire broken, or even if the engine moved
its foundation, it would run wild un-
der a full bead of steam.
June 15, 1915
P 0 W E r.
815
There certainly is no machine called upon to operate
under as many trying conditions as the traction engine
of a threshing outfit. A stationary engineer would hardly
care to operate a unit under such c litions.
While descending a hill the furnace door is usually
opened and perhaps the fire damped in order to pro-
ted the crown-sheet, which now lias no water over it.
At times on a short hill this precaution is not taken,
and when level ground is reached the water comes surging
hack over the heated plate; yet, it is comparatively sel-
dom that an explosion occurs. There are occupations
mine monotonous than that of the engineer of a traction
engine.
y.
M.©ftsiiry Csrafldle°©iil ISuariaeir
The rotarv crude-oil burner illustrated herewith is
manufactured by G. E. Witt Co., 862-864 Howard St.,
San Francisco, Calif. The principal feature is the placing
of the burner on a horizontal shaft in front of the furnace.
away from the heat, the air passing through it carrying
the heat toward the hack ^<( the boiler, which overcomes
By G. A. Robertson
Then' has been considerable comment recently among
refrigerating engineers as to the proper manner of in-
stalling relief valves or other similar devices to guard
against serious accidents from excessive head-pressure iv
tin- refrigerating system.
Some have located a relief valve in a bypass line be-
tween the suction and discharge lines of the compressor,
and there have been a few installations of automatic
suction stop valves. Both of these methods have features
that are undesirable. The relief valve installed in the
bypass between suction and discharge lines, is set so as
to let ammonia gas in the high-pressure side pass to
the low-pressure side of the system, when the head pres-
sure for some reason has increased to an undesirable
point. When this valve has been lifted off its seat
once or a few times, it is almost sure to leak. In order
to inspect it, guard valves would have to be installed,
which are undesirable, or the engineer would have to
shut down and pump out the pipe lines that were by-
passed. This means loss of time and a lot of trouble.
The automatic stop valve on the suction line to the
compressor seems to be good in theory. The valve and
automatic parts are so arranged that when the head-pres-
sure reaches a certain point, the valve closes and cuts
Rotary Crude-Oil Burner Applied to a Return-Tubulab Boiler
trouble from overheating. The burner is driven by
a motor, and the device is self-contained. With the
exception of the burner, all of the apparatus is outside
the furnace.
This burner is suitable for boilers of small capacity,
and is noiseless in operation. It has also been applied to
boilers up to 140-hp. capacity, which den strates its
wide range of application for both high- and low-pressure
work.
v
Peripheral Speeds— As compared with the 38 ft. per sec,
which is considered the limit in safe speed for a cast-iron
flywheel some of the peripheral speeds attained by the
aisks of steam turbines are striking. In a paper presented
to the Manchester Association of Engineers, R. F. Halliw.lt
says: "The highest peripheral speed which it is possible to
employ is probably found in the 300-hp. DeLaval turbine, in
itrhlch, with a 30-in. wneel running at 10,000 r.p.m., a velocity
of over 1300 ft. per sec. is reached."
off the supply of ammonia gas to the compressor. There
is some doubt as to whether the valve would respond
when needed, since it is likely to stand for a long time
without operating.
The writer desires to call attention to an alarm in-
stallation Cor the compressor. An ordinary ammonia re-
lief valve (about 1 -in. } is placed between the cylinder
and the guard valve id' the compressor, and the outlet con-
nected to a yz-m. whistle fifteen or twenty feet from the
machine. The valve is set to blow at g5 or 30 lb. above
the usual head-pressure, dust as soon as the pressure
, cache-, this point the whistle blows and gives warning.
Should the machine be started with the guard valve
closed, the whistle gives warning immediately. The op-
erator could then stop the compressor m tunc to pre-
vent an accident.
816
P O \Y E n
Vol. 41, No. 24
Nott<
a>m
B^ A. A. Putter and S. L. Simmering
SYNOPSIS — Rules and approximate equations
for the capacity and cost of fans ami blowers.
For the production of artificial draft use is made of
chimneys, fans, blowers ami steam jets. Under ordinary
conditions a chimney 125 ft. high will give a draft of
about 0.75 in. of water, or about 0.4:5 oz. pressure, ami a
chimney 250 ft. high will give a draft of about 1.5 in. of
water, or O.ST oz. pressure.
A chimney, once built, i- limited in its capacity, where-
as a fan may ordinarily have a range of pressure from
0.25 oz. to i oz.. depending on the speed at which it is
operated. This range of draft pressure makes it readily
possible to meet any overload which may be suddenly
demanded of the plant. A combination of the natural or
chimney draft and forced draft is frequently used. The
chimney draft in this case is made sufficient to over-
i ome the resistance to the flow of the gases due to the tines.
passages ami chimney walls, while the draft produced
h\ the fan is sufficient to overcome the resistance to the
air in passing through the fuel bed and also to supply
the necessary air for the combustion of the fuel.
Aie Keqciked for Combustion
If the coal burned consisted of pure carbon and perfect
mixing were possible, about 12 lb. of air would be needed
for every pound of fuel burned. As a general rule, how-
ever, under actual operating conditions about 18 lb. of air
is required per pound of coal. The volume of one pound
of air at 32 deg. F. and atmospheric pressure is approxi-
mately 12.5 cu.ft.; heme, the total volume necessary at
this temperature to burn one pound of coal is about 225
cu.ft. For any other temperature t the volume becomes.
(460 + /) 225
492
If
it- — Weight of coal burned per hour;
/ = Temperature at which the air or gases enter
the draft-producing apparatus;
A = Volume of air in cubic feet per minute:
then
225 w (460 -M)
— or, A
60 X 492
The values for /. for different temperatures are as follows:
GO deg F.
3 96
300 deg. F.
5 79
80 deg F.
4 11
4110 .lee. F.
6 55
100 deg F.
-1 27
5 lug. F.
7 32
5 03
600 deg I
8.09
The forced-draft apparatus would handle the air at a
temperature of about 80 deg. P., and an induced-draft
ipparatus at about 550 deg. P., if i conomizer were
used. Hence, from the above the following approximate
rales are deduced :
Hull1 1 — The cubic feet of air to be supplied per min-
ute by a forced-draft apparatus is equal to four times the
number of pounds of coal burned per hour.
Rule 2 — The cubic feet of gases handled per minute by
the induced-draft apparatus when no economizer is used,
is equal to eigbt times the number of pounds of coal
burned per hour.
c \i'M ii'y and Cost of Pans
Table 1 gives the capacity of fans in cubic feei per min-
ute corresponding to pressure in ounces per square inch
for three different speeds. The approximate cost of the
TABLE 1. CAPACITY AND COST OF FANS AND BLOWERS
K
£
6
K
£
O
-
c_
U
O
G00
2,210
900
3,1.50
1200
1 INI
10
.-,i ii i
4,220
.SI 11
6,800
1100
9.3.50
12
450
i 25
1,580
907
10
3.170
1845
4
6,450
63
450
6,384
675
900
12,846
14
365
0 25
2.560
731
10
5.1IHI
l»ss
4
10.390
67 . 51
400
9,600
600
14,600
800
19,200
17
270
0 25
5,338
.540
1.0
10,070
1080
4
21.390
90
:;.-.i i
14.700
550
22,300
750
30.900
20
300
18.300
500
30.50O
700
42.700
25
250
22 Hi"
450
36,000
600
48,500
65
189
ii 25
10,250
:7s
10
20,490
75S
4
41.120
157
225
2 I 750
375
41.000
51 K 1
55.000
S5
■j, ii i
34,000
300
51,1
400
68,000
120
157
ii 25
14. MO
314
1 0
29,650
631
4
59,490
247.51
135
0 25
20.2IIO
270
10
40,360
541
4
81.160
315
118
ii 25
236
1 0
si 1 2a i
473
4
100,440
405
94
0 25
37.920
1SS
1.0
75,790
37S
4
152,000
563
86
0 25
46.260
172
1.0
92,430
344
4
1 ■.;,.;■:. mi
630
78
ii 25
54,400
158
1 0
108,740
316
4
218,080
675
Turbo-Blowers
Size, In
Boil
-r Hp.
Cost, iu Dollars
15
1
75
150
•Copyright. 1915, by A A. Potter, Dean of Engil
Kansas suite Agricultural College, and S !. Simmering,
Instructor in Steam and 'las Engineering, Kansas State
Agricultural College.
fan is also given in each case, and the size is expressed as
the diameter of the fan in inches. For sizes of 18 to 48 in.
t'ne relation between cost and size is very indefinite, hut
the approximate cost in dollars. ('. may he represented bv
tile equation.
0 = 0.5 D -4- 1 (lower limit)
in which U is the diameter of the wheel in inches. For
sizes of 25 to 60 in. the approximate cost is
1.66 V -4- 21 (upper limit)
and for 60 to 132 in.,
6.94 I> — 266
I" i i ect of Floe-Gas Temperature
Calculations based on a temperature of 60 deg. F. would
not be correct for temperatures of 400 or 600 ^o^., which
are common in induced-draft systems. The principles
upon which the necessary corrections are made are as fol-
lows :
When air is heated it expands, and the weight of a given
volume varies as the absolute temperature. The neces-
sary fan speed to produce a given pressure is proportional
to the square rout of the absolute temperature. The
power required to drive a fan varies as the velocity of the
How when the pressure and the outlet area remain con-
stant.
The effects of flue-gas temperature on the speed and ca-
pacity of fans are shown in Table 2.
TABLE 2. EFFECT flF FLUE-GAS TEMPERATURE
Factor for Pro-
Temperature of portional Volume Factor for Increase Factor f<>r Increosi
Gases. Deg F. at 60 Deg F of Speed io Horsepower
100 ii 77 1 28 I 28
500 0 73 1 35 1 35
550 n 725 1 38 1 38
600 0 7o 1 42 1 42
June 15, 1915 POW E I! 817
pun in iiiiiii/iiiiuiiiiii in iiiiiiiiin iiiniiiiiiiiiiiii i Minium i i iiiiiiiiiiiiiiuiini mm! inn mi n i unmnuilim
Idlitoiriisdls
The leading article of this issue should lie rend with
more than ] >:i -sin <jf interest. It tells of a moderate-sized
plant in which, by simply changing the boiler-furnace
equipment, there resulted a saving amounting, in round
numbers, to thirty-five thousand dollars per year.
Under the former conditions coal fresh from the mine
was burned in the boiler furnaees of the Bessemer Coal
& Coke Co. This fuel had a marketable value of about
one dollar per ton and one hundred tons was burned
every twenty-four bonis.
A five to six-in. layer of hone exists between the coal
deposits, and it cosi from three to four hundred dollars
a month to remove this bone from the mine. It had
no value as a fuel. When attempts were made to burn
it the result was most unsatisfactory.
Six of the power-plan! boiler furnaces were recently
equipped with mechanical stokers, and now this fuel,
that cost something like forty-two hundred dollar,- a
year to remove, is burned under the boilers, with a
saving of the run-of-mine coal formerly consumed and
a saving in the bone-removal charge. Furthermore, the
boiler-room force has been reduced from ten to six men
»lor the twenty-four hours.
This bone contains between thirty and forty per cent.
ash content and averages about eighty-five hundred
British thermal units per pound as fired. With this fuel
and the stoker equipment, the boilers have been operated
at one hundred and seventy-five to two hundred per cent,
of rating.
There is a lesson in this for the plant that might burn
low-grade fuel and does not. and it shows that intelligent
investigation into furnace conditions can result in a
surprising saving in operating expense as well as. in
this instance, the burning of a fuel that was considered
worthless. Instances are rare where such great savings
can be effected, but it always pays to be vigilant. These
people were doing their best under the old conditions,
but some one thought of improving the conditions.
§&©Meirs ffoir lL©c©sia©\2l^©s
The summary of a report by D. C. Buell before the
annual meeting of the International Railway Fuel
Association appearing elsewhere in this issue is interest-
ing as indicating the latent possibilities of the locomotive
stoker. What will perhaps come as a surprise to many is
the fact that the fundamental reason for the application
of stokers to locomotives is that maximum capacity of the
engines can be obtained with more certainty under trying
conditions than under hand-fired conditions, even with
two firemen to a cab. Formerly, the argument for
locomotive stokers emphasized the greater economy over
hand-firing and the elimination of smoke, just as did the
early statements enumerating the advantages of stokers
■for stationary boilers. Experience seems to be proving
thai it is the greatly increased capacity possible with a
minimum of labor that is the sum and substance of the
superiority of stokers for locomotives, just as if is for
stationary boilers.
Another quite natural characteristic to be expected is
that locomotive-stoker manufacturers have in most, if
not all, cases had to adapt their product to the locomo-
tives, hut were never frequently favored by designers
considering how the locomotive could be made to more
favorably receive the stoker. The stoker builders' ex-
perience parallels that of the earlj steam-turbine manu-
facturers. The turbine, of course, ran too fast, and it
was for a long time known that its speed could not lie
reduced without commercially impossible sacrifices in
economy, before builders of "the other end,"' meaning
the driven machine, made serious efforts to adapt their
products to turbine speeds.
Engineers may be progressive and radical as they wish,
but tin' fruits of their labors find commercial application
only as fast as conservative business permits.
By the way. what is the state of the art regarding
stokers in marine practice? Indications are that marine
men are going to be true to tradition ami not adopt the
stoker until its success has been absolutely assured every-
where else.
e
The first notable change in steam mains for power
plants was the doing away with the double header — the
elimination of that emergency steam container consid-
ered so indispensable when the header in service devel-
oped a serious leak. Plant designers omitted the second
header only after experience demonstrated that if the
pipe material was sound and the fitting properly done,
leaks or steam-main troubles serious enough to warrant
cutting out the entire header would not occur. The next
advance comes in the reduction of the number of flanges
on headers and in mains. A steam leak is not only an
i yesore, but makes a sound that disturbs your conscience,
drops water down the back of your neck and, unfortun-
ately, costs money. As the leaks invariably occur at
the flanges, why have more llanges than necessary?
Autogenous welding has been a great help to various
industries, and there are few places in the power plant
where it does more lasting good than it does when ap-
plied to the heavy piping. As the writer of the article
on this subject, appearing elsewhere in this issue, re-
marks, header and. pipe may be made up in lengths lim-
ited only by shipping and erecting facilities. In the case
of headers the welded header is not only lighter, being
more easily supported than a Hanged one, but it costs
less.
Welding is also proving well suited to pipe-coil con-
struction. Coils are usually inclosed in a shell or vessel,
and if a leak occurs, if must be quite serious to be quick-
ly discovered. Welding makes it possible to make up
exceedingly long coils with no joints excepi at the inlet
and outlet ends, which are outside the shell containing the
SIS
P O W E K
Vol. 41, No. 24
(•nil. Where special bends are needed, the welding process
sometimes offers an easy solution to what might be a
troublesome problem botli in construction and erection.
Quito naturally, considerable apprehension was fell in
the early days of the application of welding to high-pres-
piping. Many will not permit its application to
boilers, and it may be expected that extensive experience
with welded steam pipe or the wide dissemination of the
results of many destruction tests on welded boilers,
will lie necessary before the torch will find a field of
usefulness on boilers other than cutting old ones into
junk and facilitating their removal and transportation
to the pile. In this respect the destruction tests de-
scribed in the article referred to are interesting and en-
Leceiatt L-ncen&s© ILegps
oim aim
A- the smoke of the recent heated discussion of license
legislation rises above the good old Commonwealth of
Massachusetts, an amended license law i- seen to have re-
sulted. Supervision of boilers, inspections and licensing
remains in the hands of tin' boiler-inspection department
of the District Police.
Before considering this last amendment a little history
of tin- license-legislation tendency m the Commonwealth
during the last few years will assist in more clearl;
comprehending the causes hack of the recent change.
Section eighty-two of the original law stated that "Li-
censes shall he granted according to the competence of
the applicant . . ." Again. Section eighty-one rules
that ". . . he shall receive, within six days after ex-
amination, a license graded according to the merits of his
examination, irrespective of the grade of license for which
he applies."
In this law nothing was -aid about a man holding
grade of license being compelled to serve a specified time
before he could apply for one of a higher grade. It wa-
in 1911 that the desires of many for a time-service clause
found a plaee in the law which, as then amended, made
it necessary for applicants to have served specified limes
under lower-grade licenses before the} could lawfully ap
ply for licenses of a higher grade.
That pari of Section eighty-two relating to special
lu' rises seems to have 1 n objectionable to many manu-
facturers, particularly those whose plants were run most
of the time by water power, but which had steam power
for low-water periods or for emergency purposes. The
law allowed an engineer a special license for a particular
plant, "provided, however, that no special license shall
be granted to give any person charge id', or permission to
ate, an engine of over one hundred and fifty horse-
power." This same section also allows a man holding a
second-class license ". . . to have charge of and operate
a boiler or boilers, and to have charge of ami operate en-
gines, no one of which shall exceed, one hundred and
fifty horsepower, . .
It is Men that a plant Inning an engine or engines oi
more than one hundred and fifty horsepower and oper-
ated mosl of the time by water power was compelled to
have a first-class engineer in attendance. This, it seem-.
was the thorn in the manufacturer's side. So this year
the much-talked-of House Rill No. 1111. widely circu-
lated with a form letter urging those approving to re-
(piest their representatives to support the bill, was pre-
sented. This bill aimed to overcome the special-license
objection by providing that a person desiring to have
charge of a particular plant might, on examination, re-
ceive a third-class license, which, according to Section
twenty-one of the bill, allowed "the holder to have charge
of and operate any particular steam engine or engines."
The firemen's license would have covered the boiler or
boiler
So much was asked for in Bill 1111 that the propon-
ents suffered the experience of the dog that slopped to
look at himself while crossing the brook with a 1 e in
his mouth. A compromise was effected in which the
manufacturers are allowed to have engineers holding
special licenses to operate plants with engines of any
capacity, so long as the plants are run by water power ex-
clusively during the major part of the year.
We see no objection to tin- amendment, as it does not
make these plants more dangerous to public safety than
before, provided, of course, that the examiners do their
duty. It should ease the strained relations between em-
ployer- and engineers.
%
Tike Pluainmlb©!? saadl "Us
Can it he that the plumber intends encroaching upon
the domain of the power engineer?
From a recent issue id' the Plumbers' Trade Journal
it i- gathered that there is a growing belief among master
plumber- that their future ""resembles a broad path of
rogivss leading to the top of contract hill, the apex of
which will lie reached when the master plumber handles
not only the plumbing, but the beating, ventilating.
power plant, lighting, elevators, sprinkler equipment
and refrigeration work as well."
These are high-sounding words, my masters, and would
seem to indicate that the ""apex" alluded to is, ju-t at this
minute, impossible of discernment. It is reasonable to
say. however, that the plumber of today— once a worker
in lead and popular mainly as a medium for threadbare
witticism — has in many directions so broadened his one-
time field of endeavor as to include much inter-relcted
work. He has. for example, become "familiar with the
radiant warmth of the heating system"; he is already at-
tracted ""toward the power handled by the little copper
wire"; hi- association with boilers has privileged him to
talk intelligently on pounds pressure and B.t.u., and his
anxious inquiries in his trade papers show his interest to
lie greatly beyond the use of the soldering iron and the
pi] utter. Furthermore, he informs us that, as "con-
solidation is the modern trend in every line," be feels
that in the future he will "•handle"' a large, thick slice of
the mechanic arts — or cease to exisl '.
A most confident and ambitious person is the plumber
man. as no one will deny, lie insists that the sanitary
wholesomeness now enjoyed by the public is mainly ow-
ing to his efforts, and that in due time his trade will he
a profession.
A- to In- desire to annex the territory, to occupy the
terrain, of the powers now controlling the power-plant,
the heating and ventilatTng. refrigeration and elevatoi
domains, one is inclined to the opinion that the plumber
in his present state i- vainly striving to separate from its
main bodj a linger portion than he can successfully mas-
ticate
June 15, 1915
POW E R
•819
C©FF(
jpomidleinice
■
On page 654 of the May 11 issue is a letter requesting
information on tightening a loose crank without removing
it. I believe that it is almost impossible to do this and
make a safe job, because after the engine has been run
for some time with a loose disk it will not only hammer
the hole out of true, but will also deface the surface of
the shaft, so that the disk, if made tight, would be out
of line. Consequently, the crank would not be true.
There are several methods of tightening a disk, all de-
pending on the conditions, material available and tools at
hand. I know of one case where the disk was riveted onto
the shaft, and another where the shaft and the disk
were drilled, reamed and tapped to receive tapered bolts
at several points on the shaft. In the latter case the
disk was out of line, although it was run for some time
by leaving the erankpin brasses keyed slightly loose. This
caused a slight pound, which increased until the tap-
ered bolts became loose and hammered, so that they could
not be removed. Eventually, a new shaft and crank disk
had to be purchased. So it is cheaper in the long run
to put on the new disk first and see that the shaft end
is in proper condition before the disk is put on, or it
may lie necessary to rig a turning tool and means for
revolving the shaft to true up the battered end before
the disk is fitted.
The cause of many a loose crank disk is in the heating
before it is placed on the shaft. In most cases where
the job is to be done a long way from the shop, the disk
is blocked up on brick supports with a fire beneath it.
In many instances the fire is too hot and the flame will
concentrate through the hole in the center of the disk,
causing the edge around the hole to become very hot,
perhaps a bright-red heat before the rest of the disk
shows signs of turning red at all. This is where the
mistake is made in judging the temperature which the
metal should stand at the edge of the hole without ruin-
ing its contracting quality, causing it to crush together
or stretch when the shaft is expanding from the heat of
the disk. This is owing to the fact that the outside
edge of the disk is usually much cooler and does not ex-
pand as the shaft does, and the metal around the hole.
being hotter, is compressed, thus causing a misfit when
cold. The lire should be a slow one and very even, and
a caver should be placed over the hole to prevent the
heat concentrating on the inner surface and edges. The
disk should then heat gradually and evenly to a very
dull or cherry red and no hotter. Even though it may
be a little harder to draw on the shaft, it will contract to
a good tight fit when cold.
The space in which the metal is compressed while hot
extends back to a circle about one inch larger than the
bore for the shaft and the pin cannot be made tight
without removal and refitting, often by refitting and re-
shrinking over a shim or bushing. When the keys are
'not the proper size to lill the keyways in the shaft and
bub, small steel strips should lie made to fit on top of
them lo prevent the key from working up or down and
wearing out the sides of the .-lots, which will happen
with a loose disk or wheel, though it may not be noticed
at the I'm nt or face of the hub.
I had an experience with a crank disk that had been
overheated at the bore. This was to be put on a 650-
hp. cross-compound engine just being erected. The job
was a time contract, and the engine had to be ready or
penalties would be exacted. The time was short and it
was urgent that the disk be put on before dark, as there
was no light to work by. It was heated over a roaring
hot lire, and overheated at the center, but it went on
nicely. The engine was assembled, tightened up and
adjusted and ran smoothly with normal load. When
the overload was put on. however, the trouble was dis-
covered— the low-pressure disk had loosened, the bore
had battered about l/84 in. out of true, and one would
have thought there was 1 ft. play judging from the ham-
mering before the engine could be stopped. A new disk
was sent from the shop, but in the meantime, to avoid
loss of time and penalty, it was decided to try calking
the boss of the hub around the shaft. This held the
disk tight enough for normal load, but only contracted
the metal in the hub to a depth of y, in. or less in the
6 in. of the disk's thickness and would have given way
again as soon as load enough was put on the engine to
bring extra strain on the disk. Greater precaution was
taken in heating the next disk and it went on the shaft
nicely and gave no trouble.
R. A. Cultha.
Cambridge. Mass.
Replying to Mr. Jensen's letter, it was a mistake to
have the keys fit tight sideways. If he will pull these
and substitute keys made with side clearance, which are
tight top and bottom, driving home with a 20-lb. sledge,
he will have no further trouble. In preparing the new
keys have them made with heads to facilitate pulling
during the process of fitting, which will require some
care. After driving home, the heads can be cut off.
The keys, being tight at the top and bottom, pull the
crank to practically a forced lit on the opposite side of
the -halt.
Jonx F. Huhst.
Louisville, Ky.
I would suggest that -Mr. Jensen take out the old kevs
and replace them with new ones properly lifted. Do not
try to use up the old key- by placing liners in with them,
as this is only a makeshift.
.Making keys grip on the sides of a keyway is a method
much used by machinists in this country. Why, I do
not know. The proper way to fit a key is to have it
large enough so thai when first driven in it will go only
about three-eighths of the way. It is then driven out
and the high spots filed off. The bottom of the key
dues not require to be filed, and the sides should merely
touch.
821
P 0 W E E
Vol. 41, No. 24
Eepeat the operation, driving in and out until the ke\
readies within % in. of being home, then use a heavj
sledge for the final drive. The key is driven flush.
should any part project, chip off and file. If it has
been properly fitted there will be no more trouble.
This is the method I have used on the wheels of loco-
motives after they had been shrunk on. and were not
beaded over. The sketch did not show whether the key-
way is extended beyond the crank disk to allow the
driving out of the keys, but if not and there is room,
it will be necessary to do so. just enough to allow the
key drift to enter. "T
C. Sword.
Cohoes.- X. V.
In regard to Mr. Jensen's loose crank disk. I would
advise drilling and tapping five tapered holes, half m the
disk and half in the shaft, then screwing in tapered bolts
very tightly. Cut these off flush and peen the shaft
evenly all around so as not to throw it out of line. Take
tunc and pains with this job.
B. C. White.
Yonkers, X. V.
[Letters covering many of the points mentioned were
received from William Braunbeck, of Xew Brighton.
Penn., and James E. Xoble. of Toronto. Can. — Editor.]
Cost of Hsuadllmig Aaslhes WitSa
In the article describing the boiler plant of the Union
Brewing Co. in St. Louis, which appeared in the May IS,
1915, issue of Powkr. the paragraph on page 665 re-
ferring to the cost of handling ashes is rather ambiguous.
We are in a position to know that the 10 to 12c. was
intended as the total cost per ton. including the charge
for steam. A casual reading might give the impression
that the 10 to 12c. included only the fixed charges, such
as depreciation, interest, etc Since the article was
written we have had an opportunity to inspect one of
our systems that has been handling ashes at the rate of
60 ton- per day. and from the results of this inspection we
are confident that the main pipe will handle at least
100.000 tons before it is ready for the scrap heap. Taking
a small plant producing 10 ton- of ashes per dav. or
3000 tons per year of 300 days, as a typical example, we
have found that the cost for repairs ha- amounted to
$8.50, or $0.00285 per ton. Figuring the initial invest-
ment at $1000. interesi at 6 per cent, would amount to
$60 per year, or 2c. per ton. At the rate of 3000 tons
per year, the equipment would last for :)3:> years, or in
round numbers, say 30 years. The depreciation then
could be figured at 3.'. per cent, and this proportion of
$1000 amounts to $33.33 per annum, or $0.01111 per ton.
Summing up, tin charges for upkeep, interest and de-
preciation amount to $0.03396, or approximately $0,034.
To this must lie added a charge of about 6c. per ton
of ash for -team, making a total of $0,094 per ton, which
figure may lie compared to the 10 to 12c. given in the
article.
Ordinarily, in a plant handling 10 tons of ashes per
day. no additional labor would be required to operate the
vacuum system, but to meet all contingencies the follow-
ing comparison may be of interest: Where 10 tons of
allies per day are handled by hand over a distance of
100 ft., the cost is rarely below 20c. per ton, or a total
cost of $2 per day. Assuming this charge per ton for
wheelbarrow conveyance and also as a labor charge for
the vacuum ash-handling system, which would handle
the total amount of ashes in 2 hours, the charge against
the latter would be only 40c. as compared to the $2
given above. Adding the $0.94 for the other items enter-
ing into the cost of the vacuum system gives a total
of $1.34 for the 10 tons. Without allowing anything for
the equipment that would be needed in hand conveyance,
the saving is 66c. per day, or $198 per year of 300 days.
On this basis the earning is nearly 20 per cent, on the
investment, so that in a little over five years the equip-
ment would pay for itself. At the end of this time the
saving would be much larger, as the interest and de-
preciation items would have been eliminated.
R. H. Miller,
Girtanner-Daviess Engr. & Contr. Co.
St. Louis, Mo.
mvg=
)©££©§
The ammonia-pump piston rod is usually made of hard
hammered steel and frequently separates from the steam
piston rod. The reason for this construction is apparent.
The pump piston rod wears rapidly, and if the machine
Stuffing-box of Ammonia Compressor
is fitted with a two-piece piston rod the pump rod may
lie replaced when worn without disturbing the steam rod.
A long stuffing-box, as shown, is divided into two com-
partments by the gland A. In packing an ammonia
stuffing-box care must be taken that this gland is over
the port //. leading to the suction of the pump. With
a box constructed in tin- way the first set of packing B
is subjected to cylinder pressure. Any leakage past
this packing is reduced to suction pressure at once, thus
the second sel of packing 0 is only subject to this pres-
sure. The port // should always be kept clear. This
port can fie closed by me.fns of the plug and the space
about the gland filled with oil to act as a seal, if de-
sired.
When the stuffing-box is properly packed with alter-
nate plain (D) and sectional (E) rings, as shown in the
sketch, there is no necessity for subjecting the packing to
June 15, 1915
POWER
821
great pressure to keep the box tight. Tf the rod is worn
it should be removed at once and turned true, or if
this is impracticable a new pump piston rod should be
installed.
It is impossible to properly park the stuffing-box when
the rod is badly worn.
Thomas J. Rogers.
Brooklyn. N. Y.
lasolanae ILirasairae
n on
In answer to the inquiry of Mr. Gawthrop as to the
feasibility of using an automobile engine on natural
gas, I believe the results would not be satisfactory.
Last year in Texas, I ran upon a similar proposition.
In this case the engine was taken from an old Buiek
car and was belted to a 15-kw. alternating-current
generator. The engine was provided with a Pickering
governor, bolted to the crank case and belt driven from
the crankshaft. The governor stem, through levers,
handled the gas and air butterfly valves. We found that
it was necessary to arrange the valve levers so that, for
a given movement of the governor stem, the air valve
moved through a greater angle than did the gas valve.
This was owing to the fact that on light loads the
mixture became too lean to explode if the two valves
regulated to the same degree.
The outfit ran fairly well, although it was necessary
to watch it constantly and it required far more attention
than did the 100-hp. gas engine in the plant. The
amount of lubricating oil used was excessive, as the
engine, although in excellent condition, tended to heat
up after a three- or four-hour run. While it was im-
possible to cheek the consumption with any degree of
accuracy, it was the belief of the operators that the
gas per horsepower was at least 50 per cent, greater
than in the regular gas engine.
As regards the speed regulation, on a fairly steady
load the lights did not flicker and the voltage fluctuation
was small. However, when the load dropped off sudden-
ly the engine would speed up considerably, in which
case the engineer would run to change the gas-valve
link rod, thereby bringing the speed back to normal.
No gasoline engine will burn natural gas economically
unless means be provided to increase the compression,
such as fitting new cylinder heads. If this is not done,
the amount of gas used is excessive. For any given
cylinder dimensions an engine will develop approximately
live-eighths as much power on gas as on gasoline, in
ordinary operation. Consequently, the 60-hp. automobile
engine should develop about 50 hp. at 1000 r.p.m. or 37.5
lip. at 750 r.p.m.
Mr. Gawthrop, in using a 17V2-kw. generator, would
require not more than 21 lip. Therefore, his engine need
never deliver more than 65 per cent, of its rated capac-
ity. At this load he will do well to obtain a horsepower-
hour on less than 25,000 B.t.u., or 50 per cent, more
than a regular gas engine would use at this percentage
of full load (17,000 B.t.u. at DO per cent, load.) A
standard-make gas engine at full load will ordinarily
develop a brake horsepower-hour on 11,000 to 12,000
B.t.u. If the outfit develops 27 b.hp., the additional
heat required would be 351,000 B.t.u. per hour, which,
based on a six-hour run, would be 2,106,000 B.t.u. daily.
Not knowing the gas used, one can merely estimate
its heat content. Assuming 800 B.t.u. per cubic foot,
the autombile engine will demand 2630 cu.ft. per day
more than the gas engine. If gas costs 25c. per thousand
cubic feet, the extra fuel consumption of the automobile
engine would be about $2 10 yearly. Of course, the
lighting load will vary, so that the 27 hp. will probably
be the maximum rather than the normal load. Neverthe-
less ih,. gag consumption will be at least as much as
given above, since on any smaller load it will be still
more per horsepower-hour. Therefore, it would probably
be cheaper to purchase a gas engine, thus also avoiding
the worry, trouble and extra fuel expense that he will
undoubtedly experience with his automobile engine.
L. H. Morrison.
Fremont, Neb.
With reference to Mr. Gawthrop's inquiry, page 654.
May 11 issue, as to the use of a gasoline engine on nat-
ural gas, I would advise him to increase the compression
about 25 per cent, either by putting plates on the piston
or cylinder head or by employing a new piston to fill
up the extra clearance. Plates on the piston head are
nut satisfactory owing to the weight. He will need a
heavier flywheel also. If operated without the above, and,
as on gasoline, the engine will develop from 40 to 60
per cent, of its former power.
B. C. White.
Yonkers, N. Y.
v
I should like to call the attention of manufacturers
and dealers to the desirability of uniform-sized catalogs.
The writer, like many others, likes to file by subject, and
catalogs are very awkward to handle as they are now is-
sued. One large heating concern issues a number of pub-
lications, and no two of them that I have seen are of the
same size.
This looks like a small matter, but filing catalogs for
reference would be much more conveniently done if the
advertisers saw the matter as it appears to the user of
the catalogs.
Lewis F. Brown.
Winston-Salem, N. C.
The storage battery as a power-plant auxiliary is
looked upon by some engineers as objectionable, because
of the constant and skillful care required. The writer
believes, however, that there is no electric apparatus that
responds so readily to good care as the storage battery,
and it can be watched easily by means of a hydrometer
and voltmeter, as well as by the gassing during over-
charge. Where a battery set is properly installed in a
clean and well-ventilated place, heated in the winter to
approximately 70 deg. F., and is properly cared for and
worked in accordance with its capacity, it will repay the
owners in more ways than He.
The present lead sulphuric-acid battery appears to
reach its all-around maximum usefulness on the 220-volt
system, or less. Most batteries in power stations are
installed for emergency or standby service and depend
82a
P 0 W E R
Vol. 41. No. 24
mostly on ampere-hour capacity for maximum usefulness.
To increase the voltage above 220 means increasing the
number of cells, and proportionately increasing the cost
To keep the ampere-hour capacity the same. Consider
a 220-volt and a 5JR)-volt railway system and a proposed
ampere-hour battery. The initial cost of the former
will be less than half that of the latter, which also holds
true as to maintenance. In order to keep down the
initial cost of the 550-volt railway battery, the ampere-
hour capacity is often sacrificed, leaving a train of trou-
bles behind that are uot easily remedied, especially with
increasing load. In cases where it is possible to shut
down a few hours each night, a storage battery for
lighting purposes and light loads can be made to pay for
the investment by keeping the load factor higher on the
generating set. with a saving in coal and oil and a chance
for small repairs during shut-down periods.
Bex Dawson.
Cedar Rapids. Iowa.
On our 4"2xG0-in. Allis blowing engine, from some
unknown cause the bottom exhaust valve broke at the eye
where the stem tits in. We had no spare valves, and to
avoid a loss of several hundred dollars a day. a rapid re-
pair was necessary. The broken piece was clamped back
Valve Stem
Rivers Through valve <
Fig. 1. Exhaust Valve Repaired
Fig. 2. Dashpot Pin, Size Reduced
in place temporarily, a plate was bent into the shape
shown, and drilled and riveted to the valve. The stem
was then put in and holes were drilled through stem and
valve and countersunk. The parts were then riveted to-
gether and smoothed off to make a running fit. Fig. 1. and
the engine was started five hours after the accident.
On a 9G-in. low-pressure blowing engine with a Cor-
liss valve gear a lot of trouble was caused by the breaking
of the dashpot pins. Different kinds of material were
used without success, the pins lasting from six weeks to
three months only. A change was finally made, as shown
in the illustration. Pig. 2. Instead of making the pin
straight across, some of the metal was turned out, which
made it much lighter and gave it a chance to spring a
little. After this change, the pins lasted from six to
twelve months.
Feed K. Ginther.
Leetonia, ( Ihio.
asag mp M/suiiblbes*
inm-p Valves
When pump valves become worn they have to be faced
up or replaced with new ones. The usual way of facing
by hand, using sandpaper on a block of wood having
a true face, requires considerable work, time and sand-
paper.
The pump I have in mind has -24 valves costing $1
each, so they cannot be thrown away when they begin to
leak. The rig I use for facing the valves is made from
a square block of wood held in the lathe chuck and turned
down to the size of the disk, and the extreme end to the
size of the hole in the center of the valve to act as a
guide. Four brads, driven in and pointed so as to sink
into the back of the valve, hold it from turning while
facing. In this way old valves are made serviceable for
tune.
R. G. Currex, Jr.
Kittannimr. Penn.
An arrangement used by plumbers for the same pur-
pose as that described in the issue of May 25, on page ?24,
is made in the following way. It consists of a %-in. pipe
with a long thread on one end. over which is screwed an
iron washer about one inch smaller than the inside
diameter of the pipe to be plugged. Xext to this washer
a cup leather is placed, then a smaller washer, and a
% locknut.
The outer end of the pipe is connected to the water
service. When the stopper is inserted into the pipe beyond
the riser and the water is turned on. the pressure will
open out the cup leather and prevent any water passing
it. A ser of leather and iron washers for each size of
waste pipe will make it possible to clear almost any line
about the place.
James E. Xoble.
Toronto. Ont.
Frequently, tanks, pipes and floats of metal become
dented, which is objectionable in one way or another, and
the dent cannot be got at from the inside. There are two
ways of getting rid of the dents; one is by heating and
the other i- by hammering externally. The former method
i- preferable for very thick tanks. The heat should be ap-
plied around the depression so that the metal on the bor-
ders will be heated and expanded, and then at suitable
intervals the dented portion should be cooled. This will
keep contracting ami drawing the dented part back into
place. An easier method Jot thinner articles consist- of
tapping around the edges of the dent with a light hammer,
which will bring the dent out. Neither process is quick,
but both are effective.
A. P. Coxxok.
Washington, D. C.
June 15, 1015
r () W E R
82.;
.
Iinqf^iinri*
Geimera! Eimfteipestt
!,".,!
Butt Joint with Single (over Plnte — For a boiler shell, what
advantage over a lap joint has a butt joint with a cover plate
on orrty one side?
T. H. R.
With a single cover plate, the cover behaves simply as an
intermediate plate attached to the two main pieces by an
ordinary lap joint, and unless the cover plate is of sufficient
thickness to prevent its bending, a butt joint has no advantage
over a lap joint.
Air-Supply for Ventilation of Assembly Rooms — What
quantity of air-supply is regarded as adequate for good ven-
tilation of assembly rooms?
R. G.
The requisite air-supply by ventilating apparatus will
depend largely upon the character of building construction
and the period for which the rooms are occupied. For ordinary
conditions the average quantities recommended by authori-
ties as a minimum quantity of outdoor air which should be
supplied per room occupant per hour may be stated as follows:
For theaters, 1200 cu.ft.
For factories, workrooms, courtrooms and auditoriums,
1500 cu.ft.
For school and college rooms, 1800 cu.ft.
Reversing Eccentric with Same Angle of Advance — If the
eccentric of an engine with direct-connected valve gear is set
so that it has an angular advance of 28 deg. and it is desired
to change the direction of rotation of the engine, how far
and In what direction should the eccentric be moved to obtain
the same angle of advance with the engine reversed?
J. B.
Angular advance of 28 deg. signifies that the eccentric is
90 + 28 = 118 deg. ahead of the crank, and for opposite direc-
tion of rotation with the same angle of advance, the eccentric
should be turned back 118 deg. on the other side of the crank;
or, what would be the same thing, the eccentric might be
turned 360 — (2 X IIS) = 124 deg. forward in the first direc-
tion of rotation of the shaft.
Chimney Crack From Expansion of Lining — What causes a
crack to form all around a brick chimney at about three-
fourths of its height? The crack developed after the chimney
had been in use only a short time and reappeared after it had
been repointed.
A. H. W.
In construction, the core or lining has undoubtedly been
incorporated with the outer walls at a point above the crack,
and from expansion of the lining from heat the upper portion
of the shell has been raised from the lower portion. By driv-
ing steel wedges in the crack at a time when the lining is at
highest temperature the core, upon cooling, may separate
itself from the shell and cause no further trouble after re-
pointing the outside. The surest remedy would be to remove
the upper portion of the stack down to a point where the lin-
ing can be stopped off and rebuild the exterior in such a man-
ner that it will not be affected by the expansion of the lining.
Properties of Nlekel Steel — How is nickel steel made, and
how does its strength compare with that of simple steel?
C. S.
Nickel steel is made by adding metallic nickel, nickel ore
or ferro-nickel to the bath of the openhearth process. The
finished product usually contains 3 to 4 per cent, nickel, about
0.3 per cent, carbon, 0.7 per cent, manganese and 0.02 per cent,
phosphorus. The presence of nickel decreases the corrosive-
ness and increases the density and strength of the steel. On
account of its high elastic limit and toughness, nickel steel
is well adapted to resistance of sudden stresses and shocks.
As compared with simple steels of the same tensile strength,
a 3-per cent, nickel steel has about 15 per cent, higher elastic
limit and about 25 per cent, greater elongation, and as com-
pared with simple steels of the same carbon, the nickel steel
up to 5 per cent, nickel has about 40 per cent, greater tensile
strength with practically the same elongation and reduction
of area.
Quality of Steam by Separating Calorimeter — In using a
separating calorimeter the graduated glass gage on the in-
strument showed that the calorimeter in a given time had
collected 0.15 lb. of water, and during the same time there
was 2 lb. 14 oz. of condensate of the dry steam added to the
condensing water. What was the quality of the steam?
W. C. H.
Where W represents the weight of water that the cal-
orimeter separated from the steam, and W, represents the
weight of dry steam condensed after separation, then the
total weight would be W + W, and the quality q, or dryness,
would be represented by the formula,
Wi
Q =
W + w.
As W, = 2 lb. 14 oz. = 2"/u. or 2.875 lb., and W= 0.15 lb.,
then by substitution,
0.15
2.X75
= 0.954, or about 95 per cent.
Site of I'ump — With 50 ft. of piston speed per minute, what
diameter would be required for the piston' of a pump to supply
140 gal. of water per min., allowing 7 per cent, reduction of
displacement by slippage and piston rod?
C. W. O.
Allowing 231 cu.in. per gal. and for the reduction of capac-
ity by slippage and piston rod, the required gross displacement
would be
140 X 100
X 231 = 34,774+ cu.in. per minute,
100 — 7
which for a piston speed of 50 ft. per min. would require a
piston having
34,774
= 57.95 sq.in. of area
60 X 12
^hieh corresponds to
0.7854
or about 8 V2 in. diameter.
v/
= S.59,
Starting Torques of Motors — How do the starting torques
of series- and shunt-wound direct-current motors compare
with those of squirrel-cage and wound-rotor types of alter-
nating-current motors?
C. H. R.
The starting torque of a series motor may be several times
the full-load torque, the torque increasing much more rapidly
than the current or nearly as the square of the current, until
magnetization approaches saturation, when it varies more
nearly as the current, the maximum torque being at the min-
imum speed. In a shunt-wound motor the starting torque
varies directly as the current and may be 2 to 2% times the
full-load torque. In a squirrel-cage motor full-load torque
requires several times the full-load current, hence this type
of motor is not adapted for use where a heavy starting torque
is required. A wound-rotor type induction motor will start
under full-load torque with little more than full-load current,
and with a high-resistance rotor the starting torque can be
increased beyond the full-load torque.
Air Required for Combustion of Gas — What number of
cubic feet of air is theoretically required for the combustion
of a cubic foot of gas consisting of 75 per cent. CH4, 20 per
cent. C2H6 and 5 per cent. C3HS?
N. C. I.
In formation of the products C02 and H20 the volumes of
O3 from the atmosphere will be required in the proportions of
CH4 + 2 (O.) = C02 + 2 HaO,
0.75 of a cubic foot requiring 2 X 0.75 = 1.5 cu.ft. of Oa;
2 C2H„ + 7 (02) = 4 CO. + 6 H20.
0.20 of a cu.ft. requiring 7/2 X 0.20 — 0.7 cu.ft. of 02;
and
C3H8 + 5 (0») = 3 C02 + 4 HaO,
0.05 of a cu.ft. requiring 5 X 0.05 = 0.25 cu.ft. of Oa. That
is, combustion of 1 cu.ft. of the mixture requires
1.5 + 0.7 + 0.25 = 2.45 cu.ft. of 02.
As oxygen contained in air constitutes 20.92 per cent, of its
volume, then as 4.78 cu.ft. of air will be required to furnish
1 cu.ft. of oxygen, the 2.45 cu.ft. of oxygen needed for com-
bustion of 1 cu.ft. of gas will require 4.78 X 2.45 = 11.71 cu.ft.
of air.
824
POWER
Vol. 41, No. 24
is&rilfanuitliiQ]
\t imi
C^limidler*
By A. H.. Gibson and W. .F. Walkeb
.surfSinK
An experimental gas engine recently installed in the
engineering laboratories at University College, Dundee, ap-
peared to afford exceptional facilities for an investigation into
the cylinder losses. This engine, built by the National Gas
Engine Co., Ltd., has a cylinder diameter of 11 in. and a stroke
of 19 in., and the connecting-rod may be lengthened so as to
vary the compression ratio between the limits 5.17 and 6.62.
Governing is on the hit-and-miss principle. A special feature
is the arrangement of the cylinder jacket in two parts — one
surrounding the exhaust valve and that portion of the exhaust
passage included within the cylinder casting, and the other
covering the breech end and barrel of the cylinder. The jacket
water is led in series through the two sections, its temper-
ature being measured before and after passing through each.
The heat attributed to jacket losses in a gas engine having
the usual arrangement of jackets includes a certain amount
which, correctively, should be attributed to exhaust losses. In
In the trials the brake horsepower was varied from zero
up to this full-load capacity. Three different compression
ratios were adopted — 5.17, 5.70 and 6.62 — and three different
air-gas mixtures were used — 7 : 1, 9:1 and 11 : 1. In indi-
vidual trials of the same series the richness of the mixture
varied by not more than 5 per cent, on each side of the mean,
and in the majority of cases the variation did not exceed
2 per cent, either side.
Town gas was used, having an average analysis of: CO:,
3.S per cent.: 0:, 1.1 per cent.; CO, 13.0 per cent.; CH,, 26.3 per
cent.; C_H4. 1.7 per cent.; H. 38.0 per cent.; N, 13.1 per cent.
The gas supply was measured by a dry meter, and its mean
lower calorific value, which was used in all calculations, was
520 B.t.u. per cu.ft. The air-supply was also metered.
Systematic analyses of the exhaust gases were carried out,
mainly with a view to insuring that combustion was complete
before the end of expansion. In no case was more than a
0.70
fo.e>5
^0.60
MM1
*
Lirrk^
0.
t030
_jj££LL
Fth —
„)r«CL-
£0.i0
0.15
,r*£
y
y\
£ 50
o 45
& AD
,
^
£to
=^^
o&
~£$+££R cent
■£ to
°- m
TL0£&I£eS£,
j^_
10 15 20 £5 30
Brake Horsepower
Fig. 1. Performance with a 5: 17
Compression' Ratio; Air: Gas
= 9: 1, and 200 R.p.m.
Ratio Air to Gas
Fig. 2. Full Load with a
Compression Ratio of
5:17
150 ZOO
Revolutions Per Minute
Fig. 3. Compression Ratio = 5: IT:
Air: Gas = 9:1. Curve A at
Full Load Curve. B at .8
Load, Curve C at .6 Load
the engine under consideration the magnitude of these two
sources of loss can be ascertained with much greater accuracy.
In order to measure the heat contained in the exhaust
gases after leaving the cylinder, an exhaust cooler was fitted
to the exhaust branch. In this cooler the temperature of the
gases was reduced by their passage over a series of 33 tubes,
each % in. outside diameter and 4 in. long. The jacket water
passed through these tubes on its way to the cylinder jackets,
and its temperature was measured before and after passing
through the cooler.
The trials were carried out with a view to determine how
the distribution of heat through the engine varies with the
speed of the engine, the brake horsepower, the compression
ratio and the richness of the mixture.
The normal speed of the engine is 200 r.p.m., but in the
trials a range of speeds from 140 to 260 r.p.m. was examined.
The maximum brake horsepower depends on the speed and
mixture, its values being approximately as follows:
Spe
2d, R
P
11!
,
150
200
2.-.0
25.0
20.0
16.5
31.5
25.0
20.5
36.0
28.5
23.5
•From a paper read before the
Engineers. May 14, 1915.
Institution of Mechanical
trace of combustible found in the gas, and in the majority of
cases no trace was found.
Of the total heat in the exhaust gases leaving the cylinder,
part was absorbed by the water in the exhaust-valve jacket
and part in the exhaust-gas cooler. The latter was not
sufficiently large to cool down the gases to atmospheric tem-
perature, and their temperature on leaving the cooler was
between 200 and 300 deg. F. The heat carried away by these
gases was estimated from a knowledge of their weight, spe-
cific heat and temperature.
From the data obtained, a series of curves was plotted,
and by interpolation from these cur\es the more important
data corresponding to speeds of 150, 200 and 2."i0 r.p.m. and to
brake horsepowers of 10, 15, 20, 25 and 30 were deduced for
each gas mixture and for each compression. The main results
of the investigation may be summarized as follows:
The mechanical efficiency increases with increasing load,
diminishes as the ratio of air to gas increases (Fig. 2), di-
minishes as the speed increases (Fig. 3) and is sensibly inde-
pendent of the compression' ratio (Fig. 4). The maximum
efficiency attained in these trials, namely, at full load with
the richest (7 : 1) mixture and at the lowest speed (150 r.p.m.),
was SS per cent. At the normal speed of 200 r.p.m. and with
the same mixture, the efficiency was S5 per cent., while with
this same speed and the weakest (11:1) mixture, it fell to
76.7 per cent.
June 15, 1915
1' ( ) \Y E E
825
The thermal efficiency, as measured on the indicated horse-
power, increases with the load (Fig. 1), attains a maximum
with an air-gas mixture of approximately 10:1 (Pig. 2),
increases slightly as the speed increases (Fig. 3), and in-
creases as the compression ratio increases (Fig. 4). The max-
imum thermal efficiencies attained were as follows:
Compression ratio 5.17 5.70 6.62
, Efficiencies ,,
f 150 33.1 34.4 36.5
Speed ■,' 200 33.9 35.3 37.4
[250 31.4 35.8 37.9
As measured on the brake horsepower, the thermal effi-
ciency increases with the load (Fig. 1); attains a maximum
with an air-gas ratio of 8:1, that is, with a richer mixture
than gives maximum indicated efficiency (Fig. 2); diminishes
as the speed increases (Fig. 3), and increases with the com-
pression ratio (Fig. 4). The maximum efficiencies based on
the brake horsepower were:
Compression ratio 5.17 5.70 6.62
f 150 27.9 29.1 31.0
Speed {200 27.5 28.6 30.2
I 250 25.7 26.7 28.3
Adopting the air cycle as the standard of comparison, the
ideal efficiencies corresponding to the various compression
ratios were:
Compression ratio 5.17 5.70 6.62
Air cycle efficiency 0.482 0.501 0.532
The ratio of the actual thermal efficiency, measured on the
indicated horsepower to the corresponding air-cycle efficiency,
increases with the load (Fig. 1), has a maximum value when
the ratio of air to gas is approximately 10 : 1 (Fig. 2), in-
creases slightly with the speed (Fig. 3), and is sensibly inde-
pendent of the compression ratio (Fig. 4). At full load and
with the most efficient air-gas mixture, the relative efficiencies
■were, for all compressions:
Revolutions 150 200 250
Efficiency ratio 0.687 0.700 0.709
The exhaust losses, in per cent., diminish as the load in-
creases (Fig. 1), diminish very slightly as the ratio of air to
gas increases (Fig. 2), increase as the speed increases (Fig.
3), and diminish as the compression ratio increases (Fig. 4).
At full load the exhaust losses in these trials were between
33.6 and 42.5 per cent. The former value corresponds to a
weak mixture, high compression and low speed, and the latter
to a rich mixture, low compression ratio and high speed.
The percentage of heat carried away by the water flowing
through the cylinder jackets, not including the exhaust-valve
jacket, increases with the load (Fig. 1), diminishes as the
ratio of air to gas increases (Fig. 2), diminishes as the speed
increases (Fig. 3), and is sensibly independent of the com-
pression ratio (Fig. 4).
Since at 150 r.p.m. the period of contact per cycle, of hot
gases and cylinder walls, is 1.66 times as great as at 250 r.p.m.,
the rate of heat transmission through the cooling surfaces is
evidently much greater at the highest speed. An examination
of the indicator diagrams, moreover, shows that the maximum
pressure and temperature attained in the cylinder are approxi-
mately 6 per cent, greater at 150 than at 250 r.p.m., so that
this increased rate of transmission is obtained in spite of a
lower gas temperature. The reason is apparently to be found
in the fact that the greater turbulence of the working fluid
at the higher rates of speed increases its effective conductivity
to an extent which more than counterbalances the effects of
a smaller temperature difference and a shortened time of con-
tact. Other things being equal, a 6-per cent, increase in the
temperature of the gases would probably increase the heat
transmitted by conduction and radiation by some 15 per cent.,
so that it may be taken approximately that the effective con-
ductivity is increased in the same ratio as the speed of the
engine.
The radiation loss diminishes as the load increases, in-
creases as the ratio of air to gas increases, diminishes as the
speed increases, and increases slightly as the compression
ratio increases. At full load, radiation accounts for between
5 and 14 per cent, of the heat given to the engine, the former
value obtaining with a rich mixture, high speed and low
compression ratio and the latter with a weak mixture, low
speed and high compression ratio.
DISTRIBUTION OF HEAT UP TO END OF EXPANSION
STROKE
Since part of the heat carried away by the jacket water
passes into the cylinder walls after release, this should, in a
true heat balance, be credited to the exhaust. The item at-
tributed to radiation represents heat lost by radiation from
the hot exposed surfaces of the piston and of the unjacketed
portion of the breech, and from the outer surface of the
jackets. Although this loss is wholly due to heat flow
through tile walls, only part of this flow takes place during
the expansion stroke. The remainder, occurring after the end
of this stroke, is -also to be attributed to the exhaust.
Thus in a heat balance drawn for the working fluid up to
the end of expansion, tin- apparent heat flow into the walls is
to be increase. 1 by the greater part of this radiation loss and
to be diminished by that part of the heat transmitted to the
jacket water during exhaust. Similarly, the apparent exhaust
losses are to be increased by some small part of the radiation
loss and by that part of the heat given to the jacket water
during exhaust. The net result is that both the wall losses
and the exhaust losses, as given by direct measurement, are
to be increased by some unknown proportion of the radiation
loss.
The results indicate, in general, that of the total radiation
loss obtained by difference from the heat measurements a pro-
portion ranging from about 0.33 to 0.40 is to be added to the
apparent exhaust losses, the remainder going to increase the
.9 0.70
efficiency ra tio on I. hr _
Alk m\6A5
-'9&II —
- =7 1
^ 065
|
MECHANICAL
EFFICIENCY
AIR\T0 6AS
3 080
'
... 1
■1 1
AIR TO 6A5_
- - 9&II
-9&7
,HP^fF&^
> ,
1 i 1
- 'II
t.n,
'_*_■;
4USr Inr^
SSSsHjig/?
tvvv-
■7 \
3 30
-'9 1
1 1
AIRW6A5
£ £5
JACKET LOSSES.PER CENT.
-'9
lb
1
1
5
Compression Ratio
Fig. 4. Full Load at 200 R.p.m.
apparent jacket or wall losses. This proportion reaches its
highest value with the highest compression ratios and with
the richest mixtures.
A comparison of these with results obtained in a similar
manner by Hopkinson on a slightly larger engine, shows a
fairly close agreement. In round numbers the figures are as
follows:
Aii-
Air
= 10.8
Gas
Hopkinson Authors
8.1
Gas
Hopkinson Authors
Heat as i.hp
Heat in exhaust. .
Heat flow to walls
21
The heat entering the exhaust-valve jacket ranges from 8
to 12.5 per cent., being the greatest at low loads, low speeds
and with low compression ratios and rich mixtures. If this
be added to the cylinder- jacket loss, it gives the loss as de-
termined from trials of an engine fitted with the usual ar-
rangement of jackets.
Under favorable circumstances it appears that a heat bal-
ance sheet obtained by measuring the indicated work and
jacket heat of a commercial type of engine, and by estimat-
ing exhaust losses by difference, is in extremely close agree-
ment with the balance sheet based on the internal energy of
the gas at the end of expansion. For fairly rich mixtures and
lower compression ratios the measured jacket losses are, how-
ever, always in excess of those more correctly computed from
the internal energy of the gas.
V
Hydrogen Wa« Dlticovered or isolated in 1766 by Cavendish,
an eccentric English chemist, who called it "inflammable air."
but the French chemist, Lavoisier, named it hydrogen, mean-
ing "water former." Nitrogen was also identified as a con-
stituent of air at about the same date as oxygen and hydrogen
(1766 to 1774) and named nitrogen by Chaptal, because of its
existence in niter.
826
POWER
Vol. 41, No. 24
EllSiaoas H. A.
E-o Sttafce
The eleventh annual meeting: of the Illinois State Associa-
tion, N. A. S. E., held in Decatur, May 26-2S, proved to be one
of the best in the history of the organization. Business was
attended to promptly by the engineers, exhibits were good,
and the entertainment was lively from beginning to end.
ilood fellowship prevailed and the close cooperation between
the engineers and the exhibitors contributed largely to the
success of the convention. The first session opened promptly
Wednesday morning at the St. Nicholas Hotel, with W. H.
mgs, chairman of the local committee, presiding. After
the opening prayer by Rev. C. E. Jenney, Mayor Dan Dinneen
made an address of welcome, to which Fred W. Raven,
national secretary, responded.
Dr. G. E. Fellows, president of Millikin University, of
Decatur, in an interesting address on education, referred
briefly to the educational work of the organization, and then
turned to the broader aspect of his subject and showed how
education was correlated with the advancement made by the
buman race. Up to 150 years ago the people thought that
they needed a king to do their thinking for them and tell
them what they must do. France was the first country to
give the people the opportunity to rule themselves and to
allow them freedom of thought and action. Most of the
advancement made has been since that time. The greatest
th'ng that ever happened to this country was the act signed
by .iDi'anam Lincoln setting aside grants of lands in the
various states, which made possible the state universities
and provided higher education for the people at large. For
the past thirty years serious attention has been given to
industrial education, and during this time more progress has
been made than in all the previous years. It is evident, then,
amount ot effort to become efficient. Many men look at the
man above them admiringly and think, "He is better than I."
This admiss!on should never be made until the same effort
has been exerted to become efficient. At the close of the
address Messrs. Hickey, Tilley, Thompson, Fiske, and the
famous quartet gave an excellent and thoroughly enjoyable
performance.
At the business session Thursday morning there were 32
accredited delegates from 13 associations out of 17 belonging
to the state organization. In his report President Hill stated
that two new locals had been added in the past year and one
of these had joined the state association. The president spoke
highly of the work of the educational committee. Secretary
Anderson reported a net gain of 43 members, which was a
little over 3 per cent, of the total number affiliated with the
state body. John S. Alt, chairman of the legislative committee,
reported that license and inspection laws similar to those
in force in Massachusetts and Ohio had been presented to the
state legislature, and by compromising on the boiler pressure
and the square feet of radiation requiring a licensed engineer,
it was thought that the chances were excellent for the bill
to pass at the present sitting of the legislature. The com-
promises thought necessary were to raise the boiler pressure
from 10 to 20 lb. and to increase the radiation from 5000
to 20,000 sq.ft.
In the afternoon the engineers were taken through the
Decatur High School and shown the annual exhibit of the
pupils. In the auditorium of the school they listened to an
interesting lecture by Prof. G. E. Goodenough, of the Uni-
versity of Illinois, on the development of the steam tables
and on the properties of saturated and superheated steam.
The professor gave briefly the leading events in the develop-
ment of the steam tables, reviewing the work of Regnault,
Callendar, Knoblauch and Linde, Davis, Peake and Grindley
Delegates at Illinois N. A. S. E. State Convention"
that progress and advancement are largely dependent on
education.
In his response, John Lane, editor of the "National Engi-
neer," contended that it was a general mistake to confound
education with teaching. Schools teach men, but they must
educate themselves. If they cannot retain or apply what
they have learned, then the teaching is useless. The man
who can apply what he does know to the best advantage,
w'lether learned in college or in practice, will make the
most progress and be of the most use to the community.
After a brief talk by Charles Cullen, president of the
Central States Exhibitor's Association, W. E. Hill, state
president, was formally introduced and the meeting was
officially opened. The usual committees were appointed and
the session adjourned.
The afternoon was spent in a trip to the Wabash locomo-
tive shops. A large number of engines were being overhauled,
and the work proved to be of exceptional interest. For the
benefit of the visitors a locomotive weighing 7S tons was
raised from the floor, moved a distance of 50 ft. and lowered
upon the wheels placed for it, in five minutes. The placing
of the engine was so accurate that it was not necessary to
move it to the right or the left as it was lowered in position.
In the evening State Deputy Henry Misostow delivered an
address at a special meeting of exhibitors and engineers.
His topic was "Efficiency," of which there were two kinds,
one sensible and the other commercial. The former created
more for the same expenditure of energy. Employees were
treated »= men and encouraged to use their brains in per-
iO. ....rig their duties. In the other system men were made
into machines and their efficiency based on the amount of
their work. There should be no distinct demarcation between
engineers. Any engineer can be as good as any other provided
he puts as much energy into his work and puts forth the same
and other authorities who had contributed to the work. By
means of charts he compared the results obtained by these
various experimenters and calculators. He commented on the
accuracy of their work and in curve form presented the
results obtained from a formula he had developed after a
careful consideration of all the data that had been previously-
given on the subject.
In the evening delegates and visitors were entertained at
the exhibitors' hall, with a theater party sandwiched in be-
tween The ball game scheduled between the engineers and
supplymen for Friday morning was called off on account of
rain. At the last session on Friday afternoon, Henry Mistele,
of Milwaukee, one of the national trustees, talked on the
good of the order, referring particularly to education and
the raos* effective medium for education the association
possessed — "The National Engineer." He asked the engineers
to suppori their paper and spoke of the value of the adver-
tising section. Peoria was chosen as the next convention city,
and the f o. . owing officers were elected: Henry Misostow.
state president; Charles Scott, vice-president; G. R. Anderson,
secretary- treasurer; W. E. Hill, state deputy. "Dad" Becker-
leg installed the officers, and the convention adjourned for
another year.
The exhibits were up to the usual standard, the following
firms being represented: The V. D. Anderson Co., Crandall
Packing Co., Dearborn Chemical Co., Edward Valve & Manu-
facturing Co., Greene, Tweed & Co., Hawk-Eye Compound Co.,
Garlock Packing Co., Home -Rubber Co., Jenkins Bros., H \V.
Johns-Manville Co., Keystone Lubricating Co., Lunkenheimer
Co., "National Engineer," Peerless Rubber & Manufacturing
Co., Wm. Powell Co., "Power," Madison-Kipp Lubricator Co.,
H. Mueller Manufacturing Co., National Boiler Specialties Co.,
Perolin Co. of America, The Screiber Perfect Boiler Skimmer
& Cleaner Manufacturing Co.. Standard Oil Co.
June 15. 1915
POWER
827
Before the seventh annual convention of the International
Railway Fuel Association, held in Chicago, May 17-20, the
committee on firing practice, D. C. Buell, chairman, presenter]
an interesting report on mechanical stokers as applied to
locomotives. A brief summary follows:
The original conception of a mechanical stoker for loco-
motives contemplated the adoption of the stoker on a fuel-
economy basis. The claims were based on the fact that the
stoker supplied coal to the fire uniformly and according to the
single-scoop method; that it overcame the necessity of opening
the fire-door and the consequent cooling effect in the firebox
and that it avoided the production of black smoke. The
introduction of larger and heavier power, together with the
desire to work this power to maximum capacity on low-grade
lines where continuous firing is necessary, has brought about
a new problem. The amount of coal necessary to burn per
hour to keep these locomotives working at full capacity is
such that there has been a demand for two firemen on all
locomotives weighing over 185,000 lb. on the drivers.
The real economy of the stoker is in the increased tonnage
that can be handled by stoker-fired locomotives — not in the
saving of fuel, as seems to be the general impression. The
large, mechanically fired locomotives are able to handle more
'onnage than the same locomotives would be given if hand-
Ired, and they handle this tonnage at a higher speed and
with greater certainty than under hand-firing conditions.
The development of the stoker has made possible the develop-
ment of locomotives designed to burn coal continuously at
a rate in excess of the capacity of the ordinary fireman to
supply it, so that the real reason for the improvement and
adoption of the mechanical stoker is found in the economic
necessity of reduced operating costs. Other causes giving
an incentive to stoker development are the possibility of
increasing the capacity of locomotives already in service and
the possibility of using cheaper fuel on such locomotives.
There are three companies now manufacturing locomotive
stokers commercially; and in addition, the Pennsylvania Lines
West of Pittsburgh have developed the Crawford stoker and
applied it extensively to their own locomotives. According
to the most reliable figures obtainable on Apr. 1, 1915, there
are 935 locomotives equipped with stokers, which are dis-
tributed between twenty different lines of railroad.
There seems to be no fixed factor that can be used as a
sure guide as to the size of the locomotive that would wan ant
the installation of a stoker. One report indicates that any
locomotive of 200,000 lb. total engine weight, with cylinders
of 22 in. or over should be equipped with a stoker. A second
report states that engines having a tractive effort of 50,000
lb. or over, should be stoker-fired. It seems to be the con-
sensus of opinion, however, that locomotives should be hand-
fired when the coal consumption for an extended period does
not exceed 4000 lb. per hr. It is the general belief that the
stoker will give about 10 per cent, increased tonnage capacity
as compared with hand-firing under the same conditions as
to grade and time, although some reports indicate that the
tonnage increase will be more. Stoker-fired engines will make
better time with the same tonnage on the same grade than
hand-fired engines, and there will be a saving on the basis
of the amount of coal burred per thousand ton-miles. This
is due to the fact that additional tonnage may be handled by
stoker-fired engines with about the same gross amount of
coal as with hand-fired engines.
The meat of the whole stoker problem is, that increased
tonnage can be handled. If increased capacity of locomotives
is desired, then stokers are economical. If maximum evapora-
tion is what is required on large engines, its attainment may
result in a sacrifice of tonnage capacity. A number of other
advantages were given, such as reduction of smoke and spark
loss. The first cost of the stoker installation is between
$1500 and $1700. Maintenance cost including interest on the
original investment, is anywhere from % to lc. per mile.
This item is more than counterbalanced if a cheap grade of
fuel is used with the stoker.
Briefly summarized, the results of the use of locomotive
stokers are as follows: The stoker is over 90 per cent,
efficient. A six months' record of the use of stokers on the
Norfolk & Western R.R. shows an efficiency of 97 'i per cent.
Roads having a considerable number of stokers in service
show a performance of over 50,000 miles per engine failure
on stoker-fired locomotives. It seems conservative to state
that the stoker will show a satisfactory fuel economy based
on ton-mile performance; that is, while it may not show a
reduction in the gross amount of coal consumed per trip,
it will show that it can haul more tonnage, using about
the same gross quantity of the same or a cheaper grade of
'fuel, than a hand-fired engine. From the coal producer's
standpoint, the increased demand for slack coal and screenings
for stoker-fired engines will be of benefit. The stoker
obviates the necessity for two firemen on large engines. No
complications are introduced in the way of detention at
terminals, engine failures on the road, or in connection with
the smoke-elimination problem. To sum up, the stoker, even
in its present Btati ot development, pays in every case
where real stoker joba ar< Indicated.
Looking into the future, the development of the stoker
makes possible and practical the design of larger locomotives.
In fact, engines have been purchased within the last two
years and are being built today which would neither have
been purchased nor built had it been necessary to have
them hand-fired. Particular reference is made here to the
large decapod, mallet and triplex engines. So far, manu-
facturers have been compelled to adapt their stokers to
existing locomotives. It is safe to say that in the future
the design of large locomotives will contemplate the applica-
tion of a stoker, and the design will be modified as may
appear necessary to insure convenient, economical and suc-
cessful application of correspondingly modified and improved
stokers.
The general conditions of the central-station industry are
reviewed by T. C. Martin, in his annual report on progress to
the National Electric Light Association. While the industry
has suffered to some extent by the general business depres-
sion, and has not maintained the normal rate of increase, still
the outlook is encouraging. Figures from 65 per cent, of the
companies indicate that for the second half of 1914 there was
an increase in earnings of at least 5 per cent. The combined
operating revenue of the Brooklyn system, for example.
showed a gain for 1914 of 10.5 per cent.; the gross earnings
of the Providence system increased 9.25 per cent, over the
preceding year, and new business showed a gain of IS. 7 per
cent. The Pacific Gas & Electric Co.'s gross earnings for 1914
were about a million dollars greater than in 1913, and the
Detroit-Edison system showed a gain of 11.1 per cent. Tin-
gross earnings of the central-station industry as a whole in
1914 are estimated in excess of 375 million dollars. This is
in addition to the lighting and power work done by street-
railway systems.
The yearly peaks and load factors of the leading systems
for 1914 were as follows:
Yearly
Load
Peak Date of Yearly Factor
Load Peak Output Per
System in Kw. Load in Kw.-Hr. Cent.
Niagara Falls Power Co.. 131, 520 Jan. 5 906,513.620 78.7
Ontario Power Co 130,500 Sept. 23 781,664,400 68.4
New York Edison Co 229,787 Dec. 23 719,193,53.-, 35.7
Pacific Gas & Electric Co. 124,000 Oct. 29 658,298,000 60.6
Penn. Water & Power Co. 74.000 Dec. 17 277,200,000 42.5
Philadelphia Electric Co.. 77,728 Dec. 1 250,697,952 36.8
Boston Edison Co 65,342 Dec. 21 194,137,400 34
Brooklyn Edison Co 49,300 Dec. 9 153,946,900 35.6
Commonwealth Edison Co. 306,200 Dec. 15 1.114,130,000 43.6
Apparently, the diversity of the loads along the Atlantic
seaboard did not vary greatly, since the annual load factors
of the Boston, New York, Brooklyn and Philadelphia com-
panies are not far apart. The Pacific Gas & Electric Co., how-
ever, with its greater territory and greater diversity of load.
shows a much higher load factor, as do also the Ontario Power
Co. and the Niagara Falls Power Co.
Samuel C. Midlam died on June 2 at the age of 83 in New
York. He served >n the navy during the Civil War, was
chief engineer of the old United States Man-of-War "Otsego"
when that vessel was sunk in Albermarle Sound, and also
served on the old "Atlanta" and the gunboat "De Soto."
After his retirement from the navy, nearly thirty years ago,
he entered the service of the Hudson River Day Line. When
he retired last year as chief engineer of the Day Line steamer
"Albany," he was said to be the oldest engineer in the Unite 1
States, in point of age as well as service.
y.
Hydro-Electric PlnntM In \e\v Knelnnd are producing more
than 2,000,000.000 kw.-hr. of energy, which, if produced by
coal, would mean the annual consumption of 3,000,000 tons
of that fuel, according to figures given by Henry I. Harri-
nian, president of the Connecticut River Power Co., in an
article in the "General Electric Review."
POWER
Vol. 41, No. 24
E. A. Thompson has resigned as smoke inspector of the
City of Baltimore and will take up consulting and efficiency
engineering, with offices at the Hansa House, Charles and
German Sts., Baltimore.
Myron J. Bigelow, formerly mechanical engineer with the
Molyneux Mailing Machine Co., Buffalo, N. T., has opened a
consulting engineering office, with headquarters at 47 Haw-
thorne St., Akron, Ohio.
"I
The American Boiler Manufacturers' Association will hold
its annual convention at the Lawrence Hotel, Erie, Penn.,
June 21-23. One of the most important matters to be con-
sidered is the means of securing the adoption of the A. S. M. E.
Boiler Code by the several states. J. D. Farasey, East 37th
St. and Erie B.R., Cleveland, Ohio, is secretary.
The National Association of Master Steam and Hot Water
Fitters will hold its twenty-seventh annual convention June
21-24, at the Hotel Wisconsin, Milwaukee. An attractive
program has been arranged, and the cooperation and active
support of all members are requested to make this the most
successful convention in the association's history.
The American Supply and Machinery Manufacturers' Asso-
ciation held its annual convention at the Bellevue-Stratford,
in Philadelphia, June 3 and 4. A number of excellent ad-
dresses were made on topics vitally concerning the business
of the members, notably an address on "The Power Problem,"
by C. M. Ripley, and an address on "Fundamental Business
Conditions," by P. F. Bryant, of Wellesley Hills, Mass. The
entertainment features included a vaudeville-smoker and a
dinner-dance.
The New England Association of Commercial Engineers,
30S Equitable Building, Boston, Mass., has selected the new
building now under construction at the corner of Oliver and
Franklin St., and will use the basement and first two floors
as an exhibit, while the upper floors will be used for a meet-
ing room and lecture hall for the several engineering or-
ganizations and mechanical societies and for offices. It is
thought that the whole building will be occupied by those in-
terested in the machinery and power-equipment field. It is
expected that the exhibit will be opened on Oct. 1 in the new
building. Mr. Lewis L. Warren is manager of the exhibit.
The American Iron & Steel Institute held its eighth gen-
eral meeting on May 28 at New York. The following papers
were presented: "Blast Furnace Advancement," by Andrew E.
Maccoun, superintendent, Edgar Thomson Blast Furnaces,
Carnegie Steel Co., Braddock, Penn.; "Merchant Rolling Mills,"
by Jerome R. George, chief engineer, Morgan Construction
Co., Worcester, Mass.: "The Commercial Production of Sound
and Homogeneous Steel," by Edward F. Kenney, metallurgi-
cal engineer, Cambria Steel Co., Johnstown, Penn.; "Waste-
Heat Boilers," by Charles J. Bacon, steam engineer, Illinois
Steel Co., South Chicago, 111.; and "Recent Progress in Cor-
rosion Resistance," by Daniel M. Buck, metallurgical engi-
neer, American Sheet & Tin Plate Co., Pittsburgh, Penn.
The National Association of Manufacturers held its annual
meeting May 25 and 26 at New York. The sessions were
devoted mainly to legal and economic questions. The con-
vention adopted the report of the Committee on Fire Preven-
tion, stating that full cooperation between state legislators,
insurance companies and property owners, and the spend-
ing of more money by municipalities and legislatures for fire
prevention were the best means for reducing the enormous
waste of the nation's resources. The convention, through the
Committee on Accident Prevention and Workmen's Compensa-
tion, held that mechanical safety devices can prevent but a
small percentage of accidents, while the large majority must
be prevented by education, organization and individual cau-
tion, with emphasis upon individual caution. The Industrial
Betterment Committee rendered a preliminary report on the
legislative minimum wage, concluding that such legislation
was not wanted by employees or employers and had been un-
satisfactory to both, and that undesirable industrial condi-
tions could best be improved through practical education and
by stricter legal supervision.
The Homestead Valve Manufacturing Co., Desk D, Pitts-
burgh, Penn., is conducting a prize name contest, offering $50
cash as a prize for a suitable name for a new gate valve.
E. W. Swartwout, formerly of the Chicago office of the
Nordberg Manufacturing Co., Milwaukee, Wis., will hereafter
be associated with Mr. McLaren, in the New York office of the
company. Enlarged offices have recently been taken in the
new Equitable Building. 120 Broadway. New York. The
Chicago office will be in charge of John E. Lord.
James Beggs & Co.. manufacturers of the Blackburn-Smith
feed-water filter and grease extractor and the Beggs sewage
ejector system, have opened offices in Saginaw, Mich., and
Cleveland, Ohio. Their representatives at these points will
give prompt attention to inquiries received from the State of
Michigan and the northern part of the State of Ohio, respec-
tively.
The "S-C" Regulator Co., Fostoria, Ohio, has established
the following branch offices: Chicago, 111., 1535 Lytton Build-
ing, in charge of L. K. Deckerson and E. H. Bolton; New
Orleans, La., 315 Carondelet St., George Keller; Atlanta, Ga.,
702 Candler Building, E. F. Scott; Charlotte, N. C, 1213
Realty Building, James E. Weinhold. In Birmingham. Ala.,
the company will be represented by the McClary-Jemison Ma-
chinery Co.
The Berwind-White Coal Mining Company, Windber, Penn.,
recently ordered twenty-six 2% -in. Simplex "Seatless" blow-
off valves from the Yarnall Waring Co., Chestnut Hill, Phila-
delphia, Penn. The interesting feature of this order is that
it makes the fifth repeat order as a result of a six-months'
trial of two valves shipped Feb. 11, 1914. The Corrigan-Mc-
Kinney Co., Cleveland, Ohio, has recently ordered 56 of these
2^4 -in. valves.
The Terry Steam Turbine Co., Hartford, Conn., has ap-
pointed Merton A. Pocock as district sales manager for the
territory included in Minnesota, North Dakota and South Da-
kota. His office is 400 Endicott Building, St. Paul, and
this arrangement supersedes the company's previous selling
agreement with Robinson. Cary & Sands Co., of St. Paul. The
company has also appointed the Hawkins-Hamilton Co.,
reoples National Bank Building, Lynchburg, Va., as repre-
sentatives for Virginia.
The Diesel-type engine manufactured by the Mcintosh &
Seymour Corporation, of Auburn, New York, will in future be
sold in the Texas and Oklahoma territory through the agency
of Arthur G. Wright, 209 Slaughter Building, Dallas, Texas.
This appointment excludes that portion of Texas west of a
line drawn north and south through Del Rio. Mr. Wright's
extensive experience with the machinery business and partic-
ularly with all types of power plants, renders him a valuable
consultant to those who are considering new installations,
and his advice may be sought by all interested parties.
Among the orders recently received for Venturi meters by
the Builders Iron Foundry, Providence, R. I., are the follow-
ing: H. C. Frick Coke Co., Pittsburgh, Penn., three 4-in.
meter tubes with Type M register-indicator-recorders; Union
Bag & Paper Co., Woolworth Building, New York City, one
4-in. meter tube with Type M register-indicator-recorder;
John B. Mailers, Chicago, 111., one 3-in. meter tube with Type
M register-indicator-recorder. All these meters are for boiler-
feed service. The West India Management & Consultation Co.,
129 Front St.. New York City, has ordered for the Trinidad
Sugar Co. two 2% -in. meter tubes and Type M register-indi-
cator-recorders for the measurement of maceration water.
The company has also received two orders for meter tubes
for the measurement of air — one from the Combination En-
gine & Compressor Co., Bradford. Penn., for a 2-in. meter tube
and manometer to be used in the testing of air compressors,
and one from Purdue University, Lafayette, Ind., for a 4-in.
meter tube.
Positions Wanted, 3 cents a word, minimum charge 50c.
Positions Open., (Civil Service Examinations). Empioyi
I'.ulcaiiH). Business Opportunities. Wanted (Agents and Salesmen — ContL_
ork). Miscellaneous (Educational — Books), For Sale, 5 cents a word. ml:ii-
[ charge. Sl.UO an insertion
Count three words for keyed address
Abbreviated words or symbols count as full words.
Copy should reach v.s
Answers addressed to otu
1144 Monadnock Block
similar literature).
No information given by us regarding keyed advertiser's name or address.
Original letters of recommendation or other papers of value should not be In
closed to unknown correspondents. Send copies.
Advertisements calling fot bids. 53.60 an inch per Insertion. 1
of New York; four for Chicago
t later than 10 AM. Tuesday for ensuing week's issue
-are. Tenth Ave. at Thirty-sixth street. New York or
Chicago will be forwarded (excepting circulars or
A CAPABLE SALESMAN for power-plant apparatus; must
be posted on boilers, pumps.^heaters, and power-plant acces-
sories in general; must be man of good address, and be
capable of managing branch office in Chicago; must also be
well and favorably known to the prominent consulting engi-
neers in Chicago district, as well as the users of power-plant
apparatus; an engineering graduate preferred; state age,
education, engineering and selling experience, references and
salary expected; an exceptional opportunity for the right man;
replies will be treated confidentially. P. 531, Power.
POWER
Vol. 41
NEW rOKK, JUNE 22, 1915
No. 25
Purposeful Anecdotes
A true plain story of the success of a
plugger — to encourage those who
think only the gifted or
lucky win out.
A Life Story
TTERE is the condensed history of an engineer.
*• -*■ With self-respect and a little determination,
so he declares, anyone can do as well or better.
He was taken from school before he was 10
years old. For five years he worked at plumbing,
but did not like it. Then he worked four years at
steam and hot-water heating, attending night
school during two of these years.
Next, he became an assistant engineer on a
lake steamer. At this time he started to study en-
gineering books and journals. At 21 years he
secured a situation as an apprentice in a large
factory.
Next, he was the engineer in a large modern
hotel, after which he went with the Canadian Gen-
eral Electric Co. as trouble man in its Peterboro
works. The Ontario Government offered him a
situation as stationary engineer, and he accepted.
At present he holds a position with the Canadian
Government as chief engineer in a large plant and
has a staff of sixteen men. Incidentally, he has
received altogether several hundred dollars in the
past few years for contributions on engineering,
etc., to technical papers. He describes himself as
only an ordinary man, by no means smart or
clever, but he is temperate and has never been
afraid to do a little extra work with no extra pay.
He has been down-hearted more than once and
even wrote to Power for advice some years ago and
he received encouragement in reply. Power has
this engineer's address.
S30
po w E i;
Vol. 41. No. 25
Norfolk
SYNOPSIS Power for the electrified section of
SO miles is supplied by a 80,000-kw. steam \
at Bluestont Junction and pee substations.
Generation is at 11,000 volts three-phase, trans-
mission at Ji',.OOU rolls single-phase ami the
trolley voltage tlflOO single-phase; step-down
transformers and phase-converters on the loco-
motives transform the current for use in three-
phase induction motors. Regenerative braking
is employed.
The electrified section of the Norfolk £ Western Ry..
known as the Elkhorn grade, is located on the main line
in the southern pari of West Virginia and extends from
Bluefield to Vivian, a distance of about 30 miles. This
is a switching and short-haul division between the coal
fields and Bluefield, operated to a large extent in-
dependently of the other traffic on the main division.
In addition to the
heavy-tonnage coal-
train service, how-
ever, freight and
passenger traffic
over this section is
also handled in part
by electric locomo-
tives, which are
used as pushers on
the steep grades.
The purpose in
electrifying this
section was to in-
crease the capacity
by materially re-
ducing the time re-
quired to handle
traffic and to pro-
vide a more eco-
nomical and effi-
cient service over
the heavy grades.
The heavy freight
trains are handled
with electric loco-
motives at a run-
ning speed up the grades of 11 miles per hour, as compared
with 7y2 miles under steam operation. Further saving
in time is effected by the elimination of the delays
sioned by the steam engines occupying the tracks while
taking on coal and water at several places on the grade-.
Moreover, one electric engine lake- the place of two
Mallet steam locomotives oveT the division, or two electric
engines take the place of time Mallet- up the grades
and at practically double the speed.
The transmission and distribution system is single-
phase at 25 cycles, and power is collected from the
overhead catenary at 11.000 volts. The locomotive-,
however, are equipped with phase-converters which.
in connection with step-down transformers, change the
single-phase current of the trolley to three-phase for use
in the three-phase induction-type traction motors. Thus.
Pig. 1. Power-Plant Building and Spray Pond
while retaining all the advantages of high-voltage.
single-phase distribution and collection, the advantages
of three-phase induction motors for the heavy traction
■ a red.
Another important feature of the employment of
polyphase induction motors for traction is the electric
braking of the trains at constant speed while descending
grades. This not only utilizes the energy of the moving
trains to drive the motors as generators and thus return
j to the line, lint also permits the heaviest train to
be handled down the mountain grades with a single
engine at a uniform speed of about 15 miles per hour.
while the air brakes are held in reserve for bringing the
train to a standstill when necessary.
The Poweb Station
The ] lower station was located at Bluestone, on the
Bluestone River, mainly for the reason that this is
practically the only available source of water for boiler
feed and condens-
ing purposes in the
district, and the
company had al-
ready constructed a
dam and reservoir
here for the water
s u p p 1 y for the
steam locomotives.
The main building
contains a boiler
room 79xl5Sl/2 ft.,
and a turbine room
56xl5Si/2ft. Acjross
the east end of the
latter a section 26
ft. wide is assigned
for the switching
equipment, offices
and other facilities
and i- fitted with
intermediate floors
and galleries. On
the main floor is the
low-tension switch-
ing room, separated
from the turbine
room by a heavy wire screen; the next floor is the
operating gallery overlooking the turbine room. On
the ground floor of the extension building are the step-up
and step-down transformers, and on the second floor is
located the high-tension switching apparatus.
Coal and Asii Handling
Coal is received in hopper-bottom cars on a siding
along the south side of the station, the ears discharging
into a -tei I hopper under the track. Below the hopper is
ile-roll crusher which' empties into an inclined con-
veyor of thi I type having a capacity of about 00
ion- per hour, at a speed of SO ft. per min. This
elevates the coal to a hopper at the east end <>( the boiler-
room monitor, and from this hopper the coal is fed to a
horizontal distributing conveyor extending Longitudinally
June 22, 191J
POWEE
831
Fig. 2. High-Tension Switching Room. Pig. '■'>. Control Boahd. Pig. I. Turbine Whom. Fig. 5.
Regenerated Power Loading Rheostats. Fig. 6. One Side of Boilee Room
- 2
p o w e i;
Vol. 41, No. 25
over the boiler room. Coal is distributed by means of
nine handwher! ;ates To two storage bins
having a capacity of about 350 tons. The coal-handling
machinery is driven by alternating-current motors.
Ashes are discharged through the ashpit hoppers to
steel platform car- each carrying two 1-cu.yd. buckets.
are run outside the boiler-room basement to a
loading trolley, the buckets being lifted from the
platform ears and emptied into gondolas by means of
a traveling electric hoist. The hoist motors are 220-volt
direct current.
Boilers and Stokers
Tlie boiler plant comprises tell Stirling-type water-tube
boilers arranged in two rows with an aisle between.
Space is provided for four additional boilers. They are
designed for a working pressure of 225 lb. gage and 150
deg. superheat. Each is fitted with an underfeed stoker
of sufficient capacity to evaporate (51.000 lb. of water
per hour into steam at 300 In. gage and L50 deg. super-
heat when sup-
plied with
water a1 200
Eai b row of stok-
ers is driven by
t w i) automatic
s t e a m engines,
and the stokers
are capable o
\ eloping 300 pel-
cent, normal boil-
er rating when
burning coal hav-
ing a heat value
of 12,250 B.t.u.
Steam from the
exhaust header is
discharged into
t w o horizontal
Cochrane f e e d-
water heaters.
cadi capable of
heating
lb. of water per
hour from 4o to
g. P.
The feed water is taken from the intake canal and
pumped to the heaters by two low-head pumps of the
horizontal volute single-stage double-suction type having
a capacity of 650 gal. per min. against a head of 45 ft.
These pumps are driven by 20-hp. steam turbines. From
the heaters the water flows to the two boiler-feed pumps
which are also of the horizontal volute three-stage double-
suction type, designed to operate against a working bead
of 600 ft. These arc driven b\ 175-hp. -team turbines.
The Stack Details
The -tack is of the radial-brick type. 2fiS ft. in height,
or 250 ft. above the grate, with a minimum inside
diameter of 20 it. A 4-in. brick lining extends 75 ft.
from the bottom of the flue opening, with a 2-in. air
space between the lining and the column.
The forced-draft installation in the boiler-room base-
ment consists of three Sturtevant multivane fans, driven
by steam turbine- t! rough 1 to 1 herringbone reduction
Fi
The rated capacity of each fan is 150.000 cu.ft.
of free air per minute against a static pressure of G in. of
water when running at 540 r.p.m.
Steam-Turbine Equipm bnt
The initial equipment consists of three main generating
unit- with space provided for a fourth. These are of the
horizontal Westinghouse type rated at 10.000 kw.. with
-team at 190 lb. gage and 150 deg. superheat when
operating at a ->1 --in. vacuum and 1500 r.p.m.
Each turbine is equipped with a Le Blanc condenser,
and injection water is taken from the tunnel that run-
under the basement floor. The condenser injection water
and aii' pumps are driven by a horizontal turbine. The
air pump discharges into the intake canal and the in-
jection pump into a pipe leading to the spray-cooling
pond. Each condenser is capable of maintaining a
vacuum of 28 in. when condensing 145,000 lb. of steam
per hour, with cooling water at 70 deg. F. The exhaust
steam from the turbines driving the condenser pump is
automatically ad-
mitted to tin- main
turbines when the
supply of exhaust
steam is more than
is required for
feed-water heat-
ing. The water
from the circulat-
ing pumps of all
the condensers is
discharged into the
cooling pond. If
the supply of river
water is low ami
not suitable for
boiler use, the wa-
ter is sprayed into
the pond and then
discharged i n t o
the intake canal.
If there is suffi-
cient cold river
water of suitable
quality, the water
from the condens-
ers is not sprayed, but is discharged into the pond,
from which it is allowed to flow into the river reservoir
several hundred feet below the intake and circulates
up the stream to the intake, the complete circuit being
about 1400 ft. At the west end of the pond is a sluici
opening into two 36-in. pipes which discharge into the
river some distance below the power station. As the
normal level of the river is about 3 ft. below the bottom
■'. tlie basin may be drained by the sluice -ate
ssary.
The Steam Pipixg
The main steam header runs the entire length of tlie
boiler room on the turbiu^-room side. It is of 12-in.
ilanged-steel pipe, and is fed by 8-in. lines from the
boilers. Each boiler has an automatic nonreturn stop
and check valve, and each turbine i< led by a 12-in. line
from the header. Expansion is cared for by long radius
fiends. All straight lengths of main and auxiliary steam
Interior ok Substation
June 22, 1915
}' ( ) W E R
833
piping are of full-weight wrought steel with van Btone
extra heavy steel flanges, and all bends and offsets of the
main and auxiliary steam lines are of extra heavy steel,
the exhaust-steam piping up to 10 in. in diameter being
of merchant pipe with standard-weight screwed cast-iron
flanges, the bends and offsets of extra beavy pipe and
standard-weight cast-iron flanges. All exhaust Lines "i
L2-in. diameter or over are of cast iron with standard-
i linings.
The piping is covered with 85 per cent, magnesia
blocks 1 VI; in. thick, the smaller live-steam pipes having
one layer and the larger ones two layers. The exhaust
and low-pressure piping is covered with air-cell sectional
blocks of asbestos paper finished with rosin-sized paper
and canvas, as in the case of live-steam piping.
Generatob Inst illation
Tiie main generators have a rating of 10,000 kw. at
80 per cent, power factor, 11,000 volts, 25 cycles,
single-phase. At this rating they arc specified to operate
24 hours, with a rise in temperature not exceeding 60
deg. ('. above the temperature of the cooling air. This
temperature rating is used because the load factor and
form of the load curve are such that a rating on this basis
gives a truer conception of the size of plant required
than would be obtained by adhering to the usual temper-
ature basis of rating machines operating on a high
load factor. The armatures are wound three-phase,
the traction load being taken off one-phase only and the
auxiliary motors around the power house running off
the three-phase bus. This of course necessitates a much
larger machine for the given output, but has certain
advantages over the use of single-phase generators.
Each generator is ventilated by a blower with a capacity
ot 50,000 cu.ft. of air per minute against a static head of
5 in. of water, the fan being driven by a 100-hp.,
440-volt, three-phase motor. The blowers are located in
the basement.
There are two turbine-driven and one motor-driven
exciters. They are compound-wound machines with
commutating poles and each has a capacity of 600 amp.
at 250 volts. Voltage regulation is effected by a Tirrell
regulator.
Power for signal service is applied by two turbine-
driven generators, supplying 60-cycle, single-phase, 4400-
volt current.
Turbine Oiling System
Oil is pumped from a Bowser filter to storage tanks
having a capacity of 3000 gal. ami Located 32 ft. above
the turbine floor. From the tank it flows by gravitj to
the turbine oiling system, consisting of a water-cooled
reservoir from which the ml is pumped from the governor
and the bearings bj a gear-driven pump operated from
the turbine shaft. The oil is supplied to the governor
at a pressure of 45 lb., which is reduced to about 10 lb.
by a reducing valve before passing to the bearings. From
the bearings it returns to the cooling reservoir.
Switching Apparatus
The generator leads connect through oil switches with
a three-phase, 11,000-volt bus which is sectionalized,
three-phase power for the auxiliary services being
taken off the island section. Power for the railway
service is taken off one phase only, as previously stated.
This phase connects « ith three 5000-kv.-a., 1 1,000 to 44,-
000-volt transformers, the secondaries being connected to
14.000 single-phase feeders. The secondaries of these
transformers have their middle point- gr tded through
resistance.
Xo brick or concrete busbar compartments are used.
[nstead, the bus structure consists of copper tubing
carried on insulator- mounted on pipe framework. Cop-
per tubing and bare wire are used wherever possible,
insulated wire being employed only where the conductors
are carried in conduits. All the oil circuit-breakers are
Pig. 8. Le Blanc Condenseb undeb Turbine
electrically controlled from the operating gallery, the
control being from the auxiliary direct-current busbars
or a storage battery located in the turbine-room basement.
Regeneration Loading Rheostats
Excess regenerated power returned at no load passes
to the 11,000-volt bus and through the various trans-
formers back to the generators if they are running under
very light load or no load. l\' no other load were provided,
the regenerated power would reverse the generators and
operate them as motor-. To prevent this, a loading
device consisting of electrodes immersed in the intake
(anal and controlled I'} suitable switches, is provided.
The operation is automatic by means of a group of
relays ami magnetic switches, current transformers, etc.,
so connected that when the amount of excess regenerated
power reaches, say 300 kv.-a., the closing relays throw in
one water rheostat on the 11,000-volt bus. As soon as
the regenerated power exceeds the capacity of one water
rheostat b) 300 kv.-a.. another closing relaj throws the
second water rheostat in on the 11,000-volt bus. The
834
P 0 W E K
Vol. 41, No.
difference between the amount of excess regenerated
power and the capacity of the water rheostat in service
is made up by the generators. When the excess re-
generated power has become reduced to zero, with one
rheostat in service, all of the rheostatic load being sup-
11,000-VOLT TROLLEY
Y
■11,000 Volts-
rmmmmmsummuir)
PHASE
9) CONVERTER •
■7esvo/is ->(<— 7es volts
3-PHASE
TRACTION MOTOR
"X
Fig. 9. Phase-Convertee Circuit
plied by the generators, one of the tripping relays trips
the circuit-breakers and tins cuts the rheostat off the
ll.OOO-volt bus. These water rheostats are located outside
of the transformer house, as shown in Fig. 5.
Transmission and Substations
As previously mentioned, power is transmitted at
44,000 volts, 25 cycles, single-phase to five substations,
where it is stepped down to 11,000 volts. The oil
circuit-breakers in the substations are remote-controlled
and will be operated from adjacent signal towers or
passenger stations or the yardmaster's office, thus re-
quiring no special attendance. The transformers are
ill' the single-phase, oil-insulated, water-cooled type, with
primaries wound for 44,000 and secondaries for 11,000
volts, and arc equipped with thermostats which, at high
temperatures, close a bell-alarm circuit to the nearest
operator's office. Two transformer filter outfits have
been provided, one for the power house and the other for
the substation. Each equipment consists of a filter press,
drying oven, and motor-driven centrifugal oil pump.
Locomotive Details
From the ll.OOO-volt trolley the operating current is
taken by a pantagraph and led to the locomotive trans-
former through an oil circuit-breaker. A phase-converter
is connected to the low-tension side of the transformer
and operates constantly when the locomotive is in service.
To its extended shaft are coupled a blower for cooling
the motors, transformer and other parts, and through a
clutch, the air compressor. The converter is an induction
motor with a short-circuited or cage-wound secondary,
having two windings on its stator, one to drive the rotor
and the other to furnish current out of phase with the
main supply current. The motor circuit of the primary
winding of this converter is connected across the second-
ary of the locomotive transformer and receives current
at 725 volts. The arrangement of winding is such that
with the converter running, a current of 90-deg. phase
displacement is induced in the second winding on the
primary of the converter. By connecting this displace-
ment circuit to the middle tap of the main transformer,
a three-phase current is produced by the ordinary
No. Equipment
10 Boilers
10 Stokers
1 Stack
PRINCIPAL EQUIPMENT OF NORFOLK & WESTERN RY. ELECTRIFICATION*
Kind Size Use Operating Conditions
Stirling 677-hp Steam generation 200-lb. gage. 150 deg. superheat
Underfeed With boilers Capable of 300 per cent, rating
Radial-brick 268 ft. high
Serving boiler?.
Maker
Babcock & Wilcox Co.
Westinghouse Machine Co.
Alphons Custodis Chimney Con-
struction Co.
C. B. Nicholson & Co.
1 Coal-and ash-
handling equip-
ment.
2 Feed pumps
Boiler draft Turbine-dr
6-in. water press.; 540 r.p.m- B F. Sturtevant Co.
H Beaumont & Co. and
Shephard Crane & Hoist Co.
Boiler feed G50 gal. per
against 600-ft. head, 2750
2 Feed pumps. .
Horizontal, volute,
single-stage Supply to heater .
Cochrane Heating feed water
Horizontal, three-
phase 10,000-kv -a. Main power units..
1 Cooling-pond
equipment
Steel piping and
650 gal. per min. against 45-ft. head. 1S00 r.p.m.
225,000 lb. water per hr. from 40 to 205 deg. . . .
Steam press. 190 lb., 150 deg. superheat. 2S-!-in.
vac, 1500 r.p.m., 11,000 volts, single-phase
for traction service, three-phase for auxiliary
service.
LeBlauc Main turbines 145.000 lb. steam per hr. with cooling wac-r at
70 deg.— 28-in. vac
Westinghouse Machine Co.
Westinghouse Machine Co.
Harrison Safety Boiler Works
Westinghouse Machine Co. and
Westinghouse Elec. & Mfg. Co.
Spray .
Condensing water. ,
Pipe fittings... .
Valves
Cast-iron pipes.
Pipe covering. . .
3 Transformers. .
Heat insulation for pip-
ing and flues
Kill amp. -hr. Control equipment... 220 volts.
Turbine-driven GOO-amp. . . . Excitation for main gen-
erators L'.'iii volts, 2200 i
Motor-driven 600-amp. Excitation for main gen-
erators 250 volt-
motor
Single - phase, oil-in-
sulated water-
cooled 5000-kv.a. In power house; traction
load 11,000 to i 1,000
Westinghouse Machine Co.
Spray Engineering Co.
M. W Kellogg Co.
B. F. Shaw Co.
Prall & Cady Co.
Glamorgan Pipe & Foundry Co.
driven by three-phase
Westinghouse Elec. & Mfg. Co.
•house Elec. & Mfg. Co.
Westinghouse Elec. & Mfg. Co.
Westinghouse Elec & Mfg. Co
General Electrio Co.
1 Crane
♦Substation, line ;
equipment not listed.
June ZZ, 1915
P 0 \Y E R
two-phase and three-phase methods of connection (see
Fig. 9). It is necessary only to convert a portion of
the current used in the motors, as a large part comes
directly from the main transformers. For starting the
converter, a single-phase series commutator-type motor
is mounted directly on its shaft.
Each locomotive is equipped with eight traction motors
jf the three-phase induction type with wound sec laries
for four-pole and eight-pole operations. There are two
running speeds, namely, 1 1 and 38 miles per hour.
In starting, resistance i- inserted in the sec lary circuil
of the motor by means of a liquid rheostat. For the
14-mile speed all the motors arc connected in parallel
having the eight-pole combination, and for the 28-mile
speed they are also connected in parallel, but with the
four-pole combination.
fS
Saf© Gtymirdl Gravis© Glass
In the safe operation of a boiler it is of the greatest
importance to be able to see the exact water level, and
the more clearly the water line can be seen, the better
for all concerned. In this connection the Reordwa]
Manufacturing & Sales Co., of Chicago, has recently
perfected a gage-glass reflector and guard which makes
the water show red and protects the operator againsl
accident by breakage of the water glass. The device
surrounds the gage-glass, it
i.~ made of aluminum with
a wire-glass front. Within
the casing an electric light
so reflects on the water as to
make it appear red, thus
making a positive distinction
between that part of the glass
containing water and the
part containing steam. The
water level can lie seen from
any point in front of the
guard and the possibility of a
false level due to discolora-
tion of the glass or condensa-
tion running down the sides
is avoided.
At both the top and bottom
of the reflector rubber gas-
kets prevent the metal from
touching the water class, and
as the latter is inclosed, it is
maintained at a temperature
approaching that of the
steam. The glass is not sub-
jected to drafts in the boiler
room, and the strains due to expansion or construction
are obviated to such an extent that breakage is less fre-
quent. Even if breakage should occur, the aluminum
casing and the wire-glass cover protect the fireman from
any serious injury. The reflector is made to fit any stand-
ard water-gage glass and is easily applied.
Railroad Expenditures — The average expenditure of one of
the leading Eastern railroad systems every time the clock
ticks off a minute, is $191.63 for supplies. In a year it buys
$100,722,006 worth of material of such wide diversity as coal
and soft soap, ink and feather dusters, steel and paint.
Reflector and Safe
Guard
Getting a High Vai (TOM
The engineer was summoned to the office upstairs to
see what was wrong with the radiator. Though it was a
\aouuni system, the radiators were lull of water, which
indicated stoppage in the return line. After examining
all valves on the return line back to the boiler room, lie
went to the vai iiiini pump. Sure, there was 25 in. of
vacuum, and the pump was running free and easy, but
the valve on the suction pipe was closed. The fireman
stated he could not keep a good vacuum on the gage with
the suction \al\e open, so he closed it and used a little
more city water on flic spray jet and held up the vacuum
beautifully. — R. A. Cultra, Cambridge, Muss.
[mpoeted for * Purpose
The inclosed clipping is from a recent issue of an
English magazine. The unknown professor mentioned
in the advertisement has evidently copied his idea from
bis American brother faker, but he has put in a few new
points which are about as funny as anything I have
ever seen in an advertisement. Tie tells prospective
customers that coal ore improves on nature by making
the coal give out just as much heat as usual, but that the
coal will burn just twice as long as usual.
SCIENCE VERSUS NATURE
Science has demonstrated how it can triumph over nature,
for here is a product of mankind which actually improves
nature and makes coal give out just as much heat as usual,
but uses only half the energy.
COAL-ORE — THE HEART OP THE COAL
It is nothing more nor less than the scientific adaptation
of the natural elements of heat storing as discovered by the
eminent professor who conducted the experiments. The
application of coal-ore has demonstrated infallibly that
coal can be made to last twice as long and yet still give out
the same heat. A single shilling packet will be ample to
treat a Tun of Coal.
■I, inns /•.'. Noble, Toronto, Ont.
Circuit 1 ^complete v.\ a Foot
It was the custom of the repairmen in the car barn of
a street railway to set various traps to shock any new
comer. The drinking water was kept in a bucket on a
small shelf. A carefully concealed live wire had been run
down the back of the post with a free end of sufficient
length to be broughl around the post and hooked on to the
handle of the bucket. One day a new man started to
work, and the water-bucket trap was promptly set for
him. Water was sprinkled on the floor around the drink-
ing place to make sure that the ground connection would
be u 1. After the new comer had taken several drinks
without result (the connections being examined carefully
after each drink and pronounced 0. K.) and the rest had
gone thirsty all the morning, someone inquired as to his
"open-circuited condition." The explanation was quite
a surprise to everyone, as he stated that he had helped to
shock new men in his time and was perfectly well aware
that the water bucket was loaded. He explained that the
d he was noi affected was, that he was so unfortunate
as to have a cork foot in place of one he bad lost, and I lis I
it was only necessary for him to raise the good foot from
the ground when getting a dipper of water. The limp
was on the new- comer, but the laugh was on the gang. —
J. E. Terinmi. Hartford, Conn.
83G
POWE E
Vol. 41, No. 25
,ct©rs AilfecttiiniE C©minmo,teili©ini
By Arthur II. Brame
SYNOPSIS — The influence »/»<// commutation of
armature reaction, induction in the commutated
coils, local currents in the short-circuited mils,
and the proper selection of brushes.
In Hit' study of commutation it is necessary 1" considei
separately the influence of the distortion of the main mag-
netic field by the field produced by the armature current,
the induction in the commutated coils by the sudden stop-
ping and starting of the currents in the opposite direction,
the local currents flowing in them while they are short-
circuited by the brushes, and the important part played
by the brushes.
Consider first the armature carrying a current supplied
from some external source, as in a motor, while the field
magnets are left unexcited. Conductors on the same
side of the neutral plane carry currents in the same di-
rection, while the conductors on one side carry cur-
rents in the opposite direction from those on the other
side. The armature as a whole is, therefore, producing
a cross magnetization, or a magnetic field across that
which is established by the field magnet (see Fig. 1).
Since two magnetic fields cannot exist in the same place
at the same time, the outcome is a field across the armature
which is the resultant of the armature and the field-mag-
net fields. The armature field at both top and bottom
strengthens at one side and weakens at the other the
field due to the magnets, and this results in a distortion.
When the machine is running fully loaded the coils do
not reverse in electromotive force at points directly be-
tween the polepieces, but at points further around in
the direction of rotation in the case of generators and
backward in the case of mo-
tors, due to this distortion
of the field by the armature
currents (see Fig. 2). There-
fore, the brushes must he
given forward or backward
lead, according to whether
the machine is a generator or
motor: otherwise there will
be sparking.
Suppose the armature to he
divided into 60 coils con-
nected to a 60-bar commuta-
tor. The brushes will short-
circuit at least one of these
coils, and in some cases two.
as they pass from one side to
the other. The short-circuit
on any coil lasts but a brief
time, for if the armature he
running at, say 10 revolutions
per second, then one coil,
forming only 1/60 of the whole, will be short-circuited
for V600 of a second twice in each revolution.
Up to the moment of its being short-circuited by the
brush, the coil (in a two-brush machine) has been carry-
ing half the total current flowing in the external circuit,
and in Vuu0 of a second this current has to be stopped.
O
Fig. 1. Illustrating
Magnetic Field
Produced by
Armature
Fig. '.'. Showing Field
Distortion* Due
to Armature
Eeaction
the electromotive force in the short-circuited coil reversed,
and a current equal to half the external current, but in
the reverse direction, started in it. If this be done before
the short-circuit is broken the coil will break away from
the brush without any sparking, but not otherwise. The
only way to accomplish this is to give the brushes a further
angle of lead, so that the coil,
when on the point of being
short-circuited by the brush, is
cutting through the field in the
reverse direction, so that this
particular coil is developing an
electromotive force contrary in
direction to that which is urging
the current through it. The
reverse electromotive force on
short-circuit rapidly stops the
current flowing against it and
starts another in the opposite di-
rection. If the current in the
short-circuited coil has not re-
versed on the short-circuit being
broken, the current in it will he
opposing the currents in the
other coils on the side to which
it has now been connected, and
both will tend to arc across from
the receding commutator bar to
the brush, as indicated in Fig. 3.
It is evident that if the field magnet be magnetized
to a high degree the pole tips will be highly saturated and
the distorting effect of the armature current will be con-
siderably less, owing to the high reluctance introduced
into the circuit; hence the necessity for adjusting the
position of the brushes for changes in the load will be de-
cidedly less. In most modern dynamos this is done to a
great extent, and in many machines there is no spark-
ing at the brushes within ordinary variations of load,
even on large overloads, though the brushes be fixed in
position; this is especially true where carbon brushes
are employed and the ampere-turns per commutator bar
are small.
The current developed in the armature of a generator
has to be collected by brushes pressing on the commutator
segments. These are made either of copper or carbon, the
brush-holders being designed to suit. Arrangements must
be made for feeding the brushes forward as they wear, and
to allow any brush to be raised and held off while the ma-
chine is running. Carbon brushes offer more resistance
than copper, not only in the specific resistance of the sub-
stance, hut also, and more particularly, in the contact re-
sistance. This extra resistance, although it makes a
great difference in the resistance of the circuit formed
by the coil which is short-circuited by the brush, does not
appreciably affect the resistance of the whole circuit, and
it has a very beneficial effect on the commutating prop-
erties of the machine. Consider Fig. 4. The current is
here flowing cut by the carbon brush, and the coil B.
which is becoming short-circuited by the brush, has a
relatively high resistance put into its circuit, soon re-
ducing its current to zero. The current from coil A
June 22, 1915
TOW E R
831
now divides at the brush, the larger portion going direct-
ly through the brush and a small portion passing through
coil B to the brush, for the brush and coil B are in paral-
lel. As the coil moves further around, more of the brush
comes into contact with segment 3 and less with segment
fore, to strengthen the field; in a motor, however, the
oi commutation is to decrease the magnetomotive
force and to weaken the field. Iron is very sensitive to
slight increases of magnetomotive force, while it is com
paratively insensible to a considerable decrease of magnet-
Fig. 3
Pig. 4
Illustrating Directions oi Ajutaturi Currents
Fig. 5
2. until finally it is only just in contact with segment 2
(Fig. 5).
As this proceeds the resistance from 3 to 3 across the
brush is steadily increasing and, consequently, a larger
and larger part of the current in A passes through B
to the brush, until finally, as the brush breaks away from
2, there is little or no current flowing in that segment
and, therefore, there is no sparking at the break. This
enables the machine to be run with fixed brushes under
large variations in the load, often from zero to full load;
and the substitution of carbon for copper brushes has
often prevented sparking in machines that before gave
trouble in this respei t.
There is one disadvantage, however, in using carbon
brushes — one cannot allow as large a current density in
the brush contact, otherwise they would get exceedingly
hot. The maximum allowable current density found in
practice is 70 amp. per sq.in. against 250 amp. with cop-
per brushes. Since it takes a certain length of time to
reverse the current, the brushes must be of sufficient
thickness to short-circuit the coils for that length of
time; on the other hand, they must not be so wide as to
short-circuit a number of coils at the time, as this again
would increase the tendency to sparking on account of
increased self-induction.
Since the direction of a current causing a certain mo-
tion is opposite to the direction of the current caused by
that motion, it follows that in a generator the current
induced in the short-circuited coil has the opposite di-
rection with relation to the current flowing in the arma-
ture from that induced in the short-circuited coil of a
motor in the same position, when rotating in the same di-
rection. That is, if in a generator the brushes are shifted
so that the current induced in the short-circuited coil
has the same direction as that flowing in the half of the
armature it is about to join, in a motor revolving in the
same direction and having its brushes set in exactly the
same position, the current in the commuted coil (which
absolutely has the same direction as in the case of the
generator) would, relatively, have a direction opposite
to that flowing in the half of the armature to which it is
transferred by the act of commutation. While the brushes,
in order to attain sparkless commutation, must be shifted
with the direction of rotation, or must be given lead in
a generator ; in a motor they have to be shifted backward,
or given lag.
In a generator the effect of commutation is a tendency
to increase the aggregate magnetomotive force and, there-
omotive force. In generators, therefore, the danger of
sparking due to improper setting of the brushes is much
greater than in motors.
Curve 1, Kg. 6, shows the value of the resistance of
a unit section of brush contact plotted against current
density in that contact; the resistance decreases as the
current density increases, and for higher values than 35
amp. per sq.in. it varies almost inversely as the current
density, and the voltage drop across the contact bee >■-
practically constant, as shown in Curve 2. Such curves
0 10
20 30 40 50 60 70
Amperes per Square Inch
Fn
6. Current Density, Resistance, and Voltage
Drop of Bri shes
of brush resistance are obtained by testing the brushes on
a revolving collector ring and allowing sufficient time to
elapse between readings to let the conditions become sta-
tionary. The resistance from ring to brush is generally
greater than that from brush to ring by an amount which
varies with the material of the brush.
It would seem that, by neglecting the effect of the vari-
ation of contact resistance with current density, the re-
sult.- obtained would be of little practical importance. It
is found, however, that the variation in resistance is i
lv a temperature effect and that at constant temperature
the contact resistani e does not vary through such exi
838
POW E B
Vol. 41. No. 25
limits; also that, due to the thermal conductivity of car-
bon, the temperature difference between two points on a
brush contact is not very
Suppose that, having reached the value of 10 amp. per
sq.in., and the resistance having become stationary at
0.06 ohm per sq.in. (see Fig. 6), the current density
ivere suddenly increased to 40 amp. per sq.in. The re-
sistance in ohms per square inch would not fall suddenly
to 0.023, but would have a value of about 0.06, and tins
would gradually decrease until, after about 20 min., the
resistance would have reached 0.023 — the value which it
ought to have according to Curve 1. Fig. 6. This explains
why a machine will stand considerable overload for a
-hurt time without sparking, whereas if the overload be
maintained it will begin to spark as the brush tempera-
ture increases and the contact resistance decreases.
Sparking is cumulative in its effect because slight spark-
ing raises the temperature of the brush contact, which
reduces the contact resistance and causes the contact to
become worse.
The brush contact resistance is found to decrease as the
brush pressure increases and as the rubbing velocity de-
creases, but these effects can be neglected in any study
of commutation, since the change due to rubbing velocity
is small, while the brush pressure is fixed by the service
and is made as small as possible. The brush pressure is
seldom less than 1.5 lb. per sq.in. of contact surface, be-
cause at lower pressures the brushes are liable to chatter,
while if the pressure be too great the brushes will cut
the commutator if they are hard or will wear down
and smear it if they are soft. A brush pressure of 2 lb.
per sq.in. is seldom exceeded except for street-car motors,
in which the vibration of the machine itself is excessive,
and pressures as high as 5 lb. per sq.in. have to be used
to prevent undue chattering.
The average energy expended at the brush contact must
also be limited, as may be seen from the following table:*
Volts across
Kinds of Brush Current Density One Contact
Very soft carbon 50-70 amp. per sq.in. 0.6-0.4
Soft carbon 40-65 amp. per sq.in. 0.7-0.55
Fairly hard carbon 30-45 amp. per sq.in. 1.1-0.9
Very hard carbon 25-40 amp. per sq.in. 1.5-1.2
The product of amperes per square inch and volts drop
across one contact has an average value of 35 watts per
sq.in. It must be understood that these figures are for
machines which operate without sparking and without
shifting of the brushes from no load to 25 per cent, over-
load by using the proper grade of brush.
From the preceding, then, it is evident that sparkle--
commutation will be promoted: First, by dividing up the
armature into many sections so as to do the reversing of
the current in detail: secondly, by making the field mag-
nets relatively powerful, thereby securing between the pole
tips a fringe of held of sufficient strength to reverse the
currents in the short-circuited coils; thirdly, by so shap-
ing the pole surfaces as to give a fringe of magnetic field
of suitable extent; and fourthly, by choosing brushes of
proper thickness and keeping their contact surfaces well
trimmed.
m
The Velocity of Steam in Pipes commonly allowed for
medium and high pressure is 6000 to S000 ft. per min., but
the tendency of the present is toward much higher velocities
(even to double the figures given), especially where con-
siderable initial superheat is given the steam.
•Arnold, "Die Gleichstrom-maehine." Vol. 1, p. 351.
Bv Walter S waken
From far away Java comes an interesting example of
a temporary repair. A waterwheel was shipped from
San Francisco into the interior of Java to supply power
for a tea plantation. It was necessary to sectionalize
this wheel, and provision was made in the usual manner
for a light press fit for attaching the hub to the shaft.
The equipment for making the necessary press fit being
rather difficult to obtain in the interior of Java, some re-
fitting by hand was done. As a result, the fit of the mid-
dle spider (there being three spiders on the waterwheel
shaft) was too light. After three years' operation it be-
came loosened and worked endways on the shaft until
it passed tin- key. thus rotating freely.
It was necessary that repairs be made quickly, as the
accident occurred during the height of the season and
■MM
(3**v
■V rfT it7 . ':* S55fc
How the Wheel Was Made Fast
not more than two hours could be spared for the shut-
down. It was obviously impossible, with the crude tools
at hand, to arrange a new keyway or to put in setscrews :
therefore, wire cable was drawn across the spider and
wrapped tightly about the shaft by means of rough-
forged clamps, as shown in the illustrations. It is interest-
ing to note that but little more than two hours was re-
quired for making these repairs. The cure proved to
be temporary, as in about a week the spider had again
worked loose; then it was lashed in place in less than
half an hour, which procedure had to be followed sev-
eral times before the end of the season.
When the season was over, permanent repairs were
effected by providing two clamps, one on either side of
the wheel, with a notch in each which fitted about the
boss on the hubs. These clamps carried bosses which in
turn fitted into keyways sunk in the shaft, the whole
repair being further held in place* by setscrews. This
left the spider held by two split-claw clutches.
All of the work was done by native Javanese laborers,
under the direction of an engineer trained in the Neth-
erlands.
June 2-:\ L915
P 0 W E R
839
Air TesHiimg ami ttlhe
By A. G. Solomon
SYNOPSIS — The writer considers some of the
dangers met in testing the refrigeration system
with air. These dangers are mil altogether absent
when testing a new system. .1 special air pump
should In- provided always, so that the ammonia
machine need not be used as an air rum pressor.
Gage-glasses an- not needed on the discharge gas
receiver or on oil traps.
Using an ammonia compressor for pumping an air
test on a plant is something that should be given con-
siderable attention. It is customary to test the high-
pressure side of a plant with 300-lb. air pressure and the
evaporating coils and other low-pressure piping with from
100 to 150 lh. .Many engineers seem to belittle the
clanger of using the ammonia machine as an air com-
pressor.
Testing Newly Installed System
First, consider the risks in testing a new plant free
from oil and ammonia. The machine is new and has
been turned over by hand to ascertain that the clearance is
right. Then it is turned over with steam, or with the
motor if it happens to be motor-driven. With the steam
drive the speed can be as slow as desired, but with the
motor drive full speed is quickly reached. During this
time the compressor tides not draw anything from the
evaporating side, as an opening is left so that the air
is simply pulled in and forced out. Usually, much
oil is put into the compressor to lubricate the valves and
piston. Some of this lodges in small pockets in the
valve cages and the globe valves in the pipes. After
everything is ready the machine is turned into an air
compressor and the test is begun. A full stream of water
is turned through the water jackets, and often a hose
is fastened to the discharge line and water allowed to
flow over it to remove some of the heat of compression.
The machine should be stopped and allowed to cool
after a discharge temperature of not over 250 deg. I'1,
is reached. A thermometer should be inserted in the
discharge line at this time, even if it is not left there for
future use. The writer believes it would be a good thing
to insist on discharge-temperature readings being taken
during the test. The erecting engineer should he in-
structed as to what is a safe temperature and should
keep within that limit. The oil for lubrication of the
new compressor should be furnished by the builders, to
avoid the danger of using an inferior lubricant or one
with a too low flash temperature. This will mean thai
the thermometer- and the oil will be a part of the
erecting engineer's equipment. The lubricant used in
many refrigerating plants is good as far as the low-
temperature test goes, but when it comes to the question
of gasifying under high pressure and temperature, that
is another story. The danger of gas ignition and the
resultant internal explosion is not any greater in the old
system than in the new. The result of such explosion
may lie more serious in the former, owing to the possibil-
ity of ammonia being liberated.
Scale Mai Start Explosion
In one way, the writer thinks, a new system is more
liable to explosion than an old one. The cylinder surface
and the moving valves and piston are not worn to a
smooth finish, and the friction is therefore greater.
Minute irregularities in these surfaces may easily
create friction which may cause a spark that will ignite
the gas given up by the oil used for lubrication. In the
old compressor this danger is not present.
Another producer of sparks may be the particles of
scale in the pipes. However well the. piping is cleaned,
there is some scale which becomes loosened and may
find its way into the cylinder. A small piece of hard
scale, getting between the piston and cylinder wall, may
cause a spark. Also small particles of scale and grit
are sent through the compressor valves and the pipe work
at high speed. These may cause sparks.
Soapy Water as Lubricant Prevents Explosions
There is one positive preventive for such explosions
in testing a new plant. Do not use oil for lubrication.
Use soap and water or some other material which will
not give up a gas when subjected to heat. The amount
of moisture thus introduced into the system will do no
harm, as nearly all of it will be caught by the oil separator
in the discharge line.
The proper way, and a way the writer believes should
be insisted on. is the use of a special air pump for testing
both new and old systems. Such an apparatus can be
made to deliver air at a low temperature, and thus do
away with the danger of explosion.
Where it is necessary to use a motor-driven ammonia
compressor for pumping the air test, it should be stopped
often and allowed to cool. This is annoying and takes
a little more time, but it is safe. An hour or two more
or less will not make any difference to the plant, whereas
the bursting of a cylinder, receiver, valve or pipe work may
delav the starting of the plant a week or more.
Glass Gages Not Needed
The proper way to handle the gage-cocks on ammonia
gage-glasses needs some little discussion. There are two
different ideas as to what is the best position for the
cocks to be in — whether they should be left open all
the time, or closed and only opened to see how much
liquid is in the receiver.
The practice of placing the gage-glasses on the dis-
charge-gas receiver or on oil traps should be discouraged.
They are not necessary and are in most cases useless for
the purpose intended. On the discharge side of a com-
pression system the gas receiver or oil trap will be cold
up to the level of the oil, and by simply placing the hand
on it. the amount of oil contained is readily ascertained.
Glass cages usually become dirty on the inner surface and
the oil level cannot be plainly seen.
840
P 0 W E R
Vol. 41, No. 25
So this leaves but two places where glasses are needed.
The first is on the liquid-ammonia receiver. To success-
fully operate the plant the liquid level in the receiver
miM he known al all times. A class gage is the only
positive indicator. These glasses should he protected with
a fine-mesh screen to prevent pieces from flying when the
glass breaks. They should also be protected in some way
from the danger of being hit by something dropping on
them or by material being carried past the receiver. The
writer knows of one case where the wheel from a valve
directly above the receiver came loose and in falling it not
only broke the glass, but also one of the cocks was broken
off. Ladders and lengths of pipe are often carried around
in the engine room, and they may come in contact with
the glass. But besides such accidents, glasses often break
in a seemingly mysterious manner. In one plant where
a glass had been broken by being hit with something and
a lot of ammonia lost before the cocks were closed, the
chief engineer gave orders to keep the cocks shut except
when the operator wished to see the liquid level. Several
glasses broke during the following few weeks. This is
easily explained. When the cocks were opened and closed,
the liquid ammonia at the temperature of the condenser
was bottled up. The heat of the engine room caused this
liquid to expand and the pressure burst the glass. After
a little study this was overcome by leaving the upper
gage-cock open enough to keep the pressure from be-
coming high. Another scheme was tried with success in
There are on the market several styles of safety gage-
cocks that are provided with ball checks and are sup-
posed to shut the ammonia off in case the glass breaks.
These can lie depended on to a certain extent, but are like
most automatic apparatus in that they are liable to fail
when needed.
Gage on Brine Cooler
The other place where glass gages are used is on
shell-type brine coolers where it is necessary to know
the liquid level. These cocks are always left open and
the glasses do not give much trouble by breaking. The
pressure is seldom over 20 lb., and a man can get to and
shut the cocks without much danger. But they should
be provided with chains or chords so placed on pulleys
that they can be closed from a point at least twenty feet
away from the glass.
A large railroad company was handicapped by not being
able to quickly stop the engine which operated the coal and
ash conveyor, because this engine was located in a remote
and inaccessible place. When something went wrong
with one of the conveyor buckets, such as a section of
1 ■ \}M\ iff]
Fig. 1. Conveyor System, Push Buttons and Electrically Operated Valve
a plant where glasses had burst several times. If the
cocks were left open it invariably happened that some-
thing hit the glass; when they were kept closed the
pressure burst the glass. Finally, globe valves were
placed between the gage-cocks and the receiver, and the
core of the cocks was filed so that there was a small
opening even when they were closed. The filing had the
same effect as a leaky cock. Then the cocks were left
closed and the two valves left open. If the glass broke,
the amount of ammonia escaping was so small (hat a
man could get to the valves to shut them.
the conveyor chain jumping the track, which, while not
frequent, did occasionally happen, considerable damage
was caused, because the engine could not be stopped
quickly. Other accidents are likely to happen, such as
workmen getting caught in the machinery. In coal
breakers accidents caused by men being caught in the
machinery are frequent. In most mines it is necessary
I'm someone to ring a bell in order to have the engineer
stop the engine.
With the electrically operated valve herein described,
anyone can quickly stop an engine by pushing a hand-
June 22, 1915
I ' 0 \\ E B
841
push switch, any number of which may be located at
intervals along the length of the conveyor path, as a1
. I. Pig. 1. This device does not remove the cause of
accident, but it does offer a means [or preventing accidents
such as mentioned from resulting seriously, as the con-
veyor can be brought to a stop within 6 in. of travel
after a switch has been pushed.
Description of Valve
Pig. 2 shows a side and end view of an electrically
operated valve of the inverted-lever type. It is fitted with
Fig. 2. Front and Side View of the Electrically
Operated Valve
a hand lever B that carries an armature A by mean- of
which the valve is held open by the ironclad closed-circuit
magnet C , supported from the valve cover D. This
carries heavy binding posts E on either side, which take
the magnet and line terminals. The hand lever B is
suspended from the valve body by a link and carries a
trunnion F by mean- of which the valve spindle is held
in its highest, or open, position. When the current is
interrupted on the coil, a hand-push switch being
operated, the hand lever drops to the position shown by
the dotted lines, and as there is a clearance between the
bottom of the trunion tee and the nut and check nuts
G on the spindle, the weight of the lever strikes the
spindle an impact blow, so as to insure closing against the
stuffing-box friction. The pressure enters the valve body
on the top seat side and acting on the valve disk, keeps
the valve closed, aided by the weight of the disk spindle.
and the hand lever resting thereon.
A guide is placed on the side of the body opposite the
link, which fits into the crotch of the hand lever and
relieves the spindle of any strain which might be caused
by pulling the lever sideways. The two lugs on the body —
one for the link and the other for the guide — are in-
dentical and permit the hand lever to be turned to face
the opposite way.
The cover can also be fitted on so that the magnet will
face in an opposite direction, which permits the valve to
lie made either right- or left-hand to avoid interference
with obstructions in restricted places.
The magnet can be wound for a 10-cell storage battery
or 110-volt direct current. For 220 volts an outside
resistance unit is used in series with the 110-volt winding.
The current consumption is approximately 14 ampere
for the storage battery and TV ampere for either 110 or
220 volts, direct-current.
After the valve has been closed by the opening of the
circuit on the coil, it is again opened by liftirg the hand
lever to its highest position, where it will be held by the
attraction of the magnet, the circuit having been re-
established immediately alter having been opened, because
the hand-push switches arc of the self-resetting type.
Tins valve must lie used in conjunction with the ex-
isting stop or throttle valve on the engine, and should be
placed between it and tl ngine cylinder. The valve
is made in sizes from 1 to 2 in., inclusive. It is manu-
factured |,y the Schiitte & Koerting Co., Thompson and
I -'tli Si., Philadelphia, Perm.
:■:
Aitadhotpaini^ Fo'asiadl^.tlioini Bolts
asa
By Terrell Croft
The effectiveness of the adhesion between an iron
rod and the concrete in which the rod is embedded
does not appear to be generally appreciated by many
men who install concrete foundations for machinery.
For example, the arrangement shown was used in a
certain instance to provide an anchor for the founda-
tion bolts of a machine. The series of nuts and washers
on the lower ends of the bolts was entirely unnecessary,
as will lie demonstrated.
The maximum adhesion between a round iron rod
and concrete amounts to between 250 and 400 lb. per
sq.in. of contact area. A safe value for this adhesion
may be taken as 75 lb. per sq.in. These values have
been verified many times by actual tests. Working
from these data, it can be shown that if a round iron
rod is embedded in concrete to a depth equal to 30
times its diameter the rod will break before it pulls
from the cement if force is applied to effect its with-
drawal. Therefore, if a 1-in. diameter foundation
Bed of Generator
Unnecessary Nuts and Washers on Anchor Bolts
holt with its surface perfectly smooth be set in con-
crete for a depth of .'i0 in., the rod will break before
it can be pulled loose from the concrete. Eoughenini:
the rod by threading it or by chipping or by cutting
fins in it has very little effect, one way or the other.
However, as a matter of precaution it is always well
to use for a foundation bolt a rod threaded ami having
a nut on the lower end. On this nut a cast-iron build-
ing washer or a square piece of wrought-iron
can rest, which will insure against withdrawal if the
liolt is not sel 30 or more diameters in the concrete.
P U \Y E R
Vol. 41, No. 2~,
June 22, 1915
P 0 W B R
843
ASir=oa
■inxcy
it. Evens
SYNOPSIS — Probably no Mechanical device is as
Utile understood in detail, or is subjected to so
lunch abuse on one hand and praise on the other, as
the air lift. Mum/ engineers maintain that the air
lift is inefficient, and should never be employed
when anything else is obtainable; others credit it
with a higher efficiency than is actually attained.
Somewhere between the extremes is the proper
place for the system.
Two descriptive theories of the air lil'l have been ad-
vanced— one by J. P. Frizell in 1880 and the other by
Dr. Julius Pohle in 1892. Each was granted a patent
on a system of piping a well, and in each letters patent
the theory is given.
Mr. Frizell says: "My present invention has for its
object the elevation of water in a simple and convenient
manner by the introduction thereunder of compressed
air; and it consists in causing a column of water to
ascend in a pipe or conductor by the injection therein,
at or near its bottom, of compressed air. the weight of
the air and water thus commingled being overcome by
the weight of the external water which is thus utilized
as a motive power to elevate the water." . . .
Dr. Pohle says: "The object of the invention i- to
effect successfully and practically the elevation of the
water to a much greater height than has heretofore been
deemed economical with compressed air, and to avoid the
results due to an ultimate commingling of the air and
water, as well as to dispense with all valves, annular
spaces and solid pistons. In accordance with my inven-
tion, the air is not directed into the water in the form
of fine jets or bubbles, which would very readily com-
mingle intimately with the water, hut is delivered in
mass, and the water and air ascend in well defined alter-
nate layers through the eduction pipe."
Mr. Frizell claims a thorough aeration for his system,
while Dr. Pohle claims a piston-like layer formation of
air and water for his. Fig. 1 is an illustration of the
two principles.
Dr. Pohle's idea was that the pistons or layers of air
entirely tilled the cro-s-section of the discharge pipe, Inil
as shown in Fig. 1, in actual operation these air pistons
only partially lill the cross-sectional area. Consequently,
each ascending air piston cannot carry all the water
before it: a certain amount ( that contained between the
air piston on the walls of the eduction pipe) is not raised
and the air piston is said to "slip" by this water. This
slippage loss is the most serious to lie contended with in
air-lift practice.
In a mathematical theory developed by Prof. Elmo
G. Harris, it is shown that the air-slippage loss varies
with the square root of the volume of the air bubble
admitted to the water column, therefore it is advantag -
to reduce the size of the bubbles by any means possible.
This undoubtedly is nearly correct because it is only
reasonable to suppose that the sum total of air-slippage
losses will he considerably smaller in a rising column of
air and water if a large number of finely divided bubbles
are introduced than if a comparatively few large ones
are employed. In other words, il is evident that, taken
as a whole, the CTOSS-Sectional area of the pipe is more
effectively occupied b] the air in the Frizell aeration
principle of operation than in the Pohle piston-like layer
principle. Experiment plainly indicates that this conclu-
sion i> correi t.
ApPLIl \Tlo\ of THE Alt;
One of the lirst considerations in designing an air lift
for am set of conditions is the manner of introducing
the air, or the method of piping the \\r\\. Any system
£385=--. £-^BfeE~I--
Fio. I. Aeration Principles of Operation
that finely divides the air volume and provides a free
|ias>av,e lor the mixed air and water will he found satis-
factory, in Fig. 2 are shown a number of the systems
of piping most frequently installed, tin- letters A, B, C and
D referring to parts common to each system. Besides these
there are several manufael ured systems having specially de-
signed head ami foot pieces and for which broad claims
of superior economy are made. In some of these de-
pendence is put upon refined nozzles and deflector tubes
for obtaining the efficiency claimed.
Submergence
Air slippage is also affected by the amount of mi\i-
mergence, or the distance below the surface of the water
that the air is admitted to the discharge pipe. To thor-
oughly appreciate the importance of this feature in air-lift
design, consider briefly the characteristics of the bored
well and the water-bearing stratum that it penetrates.
Water-hearing strata usually consist of sand or gravel.
A - ■ point, which may he more or less remote, these
strata reach the earth's surface, where they r ;ive their
supply of water from rivers, springs or rainfall. The idi al
arrangement is the water-bearing stratum located between
two impervious strata, so (hat there is no escape of water
844
P 0 W E E
Vol. 41, No. 25
either upward or downward. Xo such perfect formation
exists, but nearly impervious confining strata are found,
so for the sake of simplicity of explanation we may
assume that the water is held in the stratum in the same
manner as in an underground pipe. This stratum we
will assume to have a source of supply without an outlet.
Suppose now. that, as illustrated in Fig. 3. a well
were drilled at .4. piercing the upper strata and entering
well, and the difference hetween the two is known as the
well head drop. The static head plus the well head drop
is known as the pumping head of the well.
Referring to Fig. 4. the air pressure introduced at A
(pounds per square inch) necessary to start operation of
the well is equal to the distance hs in feet multiplied by
0.434. and the pressure necessary to keep the well operat-
ing alter it has beeu started is equal to the difference in
rp
D^l
m
w
Open
.■End
Air Air,,
■ — Perforated
■ _,' Open
End
'//,
I
1
Fig. 2. Piping Systems Mosi Commonly Employed for Air Lifts
the water-bearing stratum. An outlet is now provided
and the water, seeking its level, will rise up in the well
until its surface at B coincides with a horizontal line
drawn from the surface C of the source of supply. The
distance from the ground surface to the water surface
in the well is known as the static hind.
If an air lift is installed in the well, as shown in Fig. 4,
and operation begun with the static head h, there will be
' A
feet of hs and the well-head drop multiplied by 0.434 ; bo
that the well-head drop in feet may be ascertained by not-
ing the starting and running pressures on the air gage
and dividing the difference by 0.434.
Besides the pressure reduction caused by actual falling
of the head in the well, there is a slight pressure drop
due to established column momentum. In other words.
less energy is necessary to keep a column of water moving
" " ■• ■' ■" "
W^^^^^^^^^^^y^^y
Pig. 3. Static Head of Well Bored to Wateb-Beaeing Stbatum
created a flow from the source of supply to the mouth
of the well. Immediately the initial water level XB drops
with a head loss XV due to the friction of the water in
passing through the stratum aud entering at the lower
end of the well. Under the dynamic conditions, the head
at the source cannot then maintain an equal head in the
than is required to start the same column from a state
of rest. This pressure difference is plainly equal to the
velocity head, which is - — , multiplied by 0.434.
There is a certain amount of frictional resistance in
the eduction pipe, and this increases the operating pres-
June 22, 1915
POWER
845
sure over that stated. It is usual to assume that this
pressure increase cancels the pressure decrease due to
column momentum. Fur all practical purposes, then, it
is sufficiently accurate to say that the submergence in
feet is equal to the air pressure multiplied by 2.31 or
conversely, of course assuming that the air-transmission
losses have been accounted for.
The air pressure that the compressor must operate
against is dependent upon the amount of submergence (plus
air-transmission losses) of the
air line. Experience has shown
that as the submergence is in-
creased the air-slippage losses
decrease, which means that a
lesser volume but increased
pressure of air is needed; on the
other hand, decreased sulunei
gence requires increased air vol-
ume but decreased pressure.
Since these two factors (pres-
sure and displaced volume) con-
stitute work, it is important
that the question of submer-
gence be carefully considered.
There are no rules or laws
that tell just what constitutes
proper submergence ; it is pure-
ly a matter to be determined
by actual experiment in each
ease. A number of tests should
be made with varying depths of
submergence and the most ad-
vantageous depth selected. This
is a very simple matter, in-
deed, and well worth the time
expended. To show the effect
of varying submergence on
the efficiency of an air lift,
there is reproduced in Fig. 5
a typical submergence curve.
The curve was plotted from the results obtained from a
test made on a well owned and operated by the City of
Hattiesburg, Miss.* As will be noted, the efficiency falls
off rapidly between 50 and 65 per cent, and between 75 and
95 per cent, submergence, but between 65 and 75 per cent,
the difference in efficiency is only about 1 per cent. The
most advantageous point of submergence is ;o per cent.
The proper percentage of submergence varies with the
dynamic lift, decreasing as the lift increases. From
numerous tests the writer has found the following to be
about right, though, as stated, only a test can accurately
determine the proper submergence in any particular case.
Lift Submergence Lift Submergence
Fig. i. Static Head
and Well-Head
Drop
25 to 50 ft 70 per cent.
51 to 100 ft 65 per cent.
101 to 150 ft 60 per cent.
151 to 200 ft 55 per cent.
201 to 300 ft 50 per cent.
301 to ton ft 45 per cent.
401 to 500 ft 40 per cent.
The Eduction Pipe
Another factor which affects to a large extent the
efficiency of operation of an air lift is the size and
design of the discharge or eduction pipe. The small
area of the well and the standard pipe diameters prohibit
nicety of construction, even if enough were known to
prepare an accurate design, but a material gain in
efficiency can be made by exercising a little care and
judgment in the use of our limited facilities and knowl-
edge.
It must be remembered that the discharge pipe trans-
mits a mixture of a practically incompressible liquid and
a very elastic gas. and both are under a varying pressure
At the lower end of the pipe the pressure is equivalenl
to the depth of the submergence, and as the mixture rise-?
the pressure reduces in proportion. The reducing pres-
sure causes the air to expand and occupy an increasing
area of the pipe. Tin-, causes the velocity of travel of
the column to increase as the top is approai lied.
The demands of high efficiency for transmitting a
mixture of air and water are conflicting. Air-slippage
losses increase as the velocity of flow is diminished, and
water frictional losses increase as the velocity squared is
increased. In figuring the pipe diameter it is necessary
to ascertain a velocity of flow where the sum of these
two losses is least. Here, again, is the need of experience
and experiment (for there is no other guide) and, unfor-
tunately, we have neither. Then, too, we have the varying
column velocity mentioned to contend with.
About all that can be said is that at no point in the
discharge pipe should i\w column velocity be as low as
30
XURVE
£20
E
G 10
fc
0
)
'£
)
M
)
BO
B0
10
Fki.
6ubmergence Percent
\ ariation in Efficiencies for Different
Percentages of Submergence
that with winch an air bubble will ascend in still water,
and on the other hand at no point should it be so high
that the water-friction losses overcome any gain obtained
by small air-slippage losses. Also, the column velocity
should increase as the air volume expands.
The writer has obtained good results with an initial
velocity of 8 to 1 1 ft. per ^-. and a discharge velocity of
22 to 24 ft. per sec. In high litis and consequently long
discharge lines, to prevent the velocity becoming excessn i
a gradually increasing pipe should be used. Initial and
final velocities iii each section of pipe of approximately
11 ft. and 22 ft. respectively will be found very satis-
factory.
Air Pipe
In a large percentage of air lifts the pipes for trans-
mitting the air are ion small. For obvious reasons these
should be as large as possible, within reason. A velocity
of travel of 30 ft. per -rr. is considered good practice.
Efficiency
If due consideration is given to the prevention of air-
slippage losses and other economy essentials observed, the
actual pumping efficiency of the air lift compares favor-
ably with that of any other system of deep-well pumping.
846
P 0 W E B
Vol. 42, No. 2S
When reliability and ronvenience are considered the air
lift stands alone, and where conditions are suited it should
be installed, by all means.
The very simplicity and reliability of the air lift have,
however, gotten it into trouble a number of times. It
has been installed where sufficient submergence was not
available, and, consequently, the efficiency proved low. The
one and only drawback to the air lift is the high per-
centage of submergence necessary to efficient operation.
The writer has obtained pumping efficiencies varying
from 50 per cent, on lifts of 50 to 75 ft. to 18 per cent,
on lifts of 900 to 1000 ft. These efficiencies were ob-
tained, of course, after experimenting to ascertain the
proper submergence.
St^eaina Geinieirgittaoira £ia Si Wood=
DisftBOisag Paasat
By Lawrence Eddy
A battery of steam boilers burning six different sub-
stances— gas. liquids and solids — in the same fireboxes is
rather unusual. Yet such are the conditions in the plant
herein described, and which are quite typical of the wood
distilleries in the East.
The steam for this plant is generated in three return-
tubular boilers rated at 150 hp. each. They are set over
stationary grates whose dimensions are approximately
6x6 ft. Air is supplied by a strong natural draft.
In the process of distilling hard woods several un-
marketable products are obtained which are also com-
bustible. They are burned, in this case under the boilers,
as much for the sake of being rid of them as for the heat
energy which they possess. When the wood is heated in
the ovens about 20 per cent, of it. by weight, is converted
into a noncondensible gas. In this plant, which burns 60
cords a day, this will amount to about 600,000 cu.ft.
every ?4 hrs. After washing, the gas is led in cast-iron
mains to the upper corner of each firebox, as shown in the
sketch. It merely escapes from the end of the pipe and
mixes with the furnace gases, burning with a pale-blue
flame in the top of the firebox. Its combustion is sup-
ported by the excess air which passes up through the
fuel bed on the grates. A steam jet placed in the pipes
just before they enter the fireboxes assists the flow of gas
and prevents the furnace gases from working back into
the mains and causing an explosion when the wood gas
is not running. As there is no gas tank in the line, the
supply at the boilers is intermittent and must be burned
just as it comes, without any regulating valves which
might cause a back pressure on the ovens.
The second class of fuels is the wood oils. These
distill over with the alchohol and acetic acid, in the
processes of purifying the wood vinegar or "raw liquor."
They separate from the alcohol and acid by gravity,
are washed, and run off to the tar sump where they mix
with or float on the tar. They still contain a considerable
amount of water and acid.
The residual tars which remain after the alcohol and
acid have been distilled off resemble in appearance the
familiar gashouse tar and have a very acrid odor, due to
acid which cannot be entirely separated from them. Be-
tween 1000 and 2000 gal. accumulates every day, and is
run off while still hot to the tar sump, together with the
oils previously mentioned. Brass piping (to resist the
acids) carries the mixture to the fireboxes, into which it
is injected with considerable force by a steam jet, as
shown. Xo attempt is made to atomize the liquid, i;
being merely hurled in large globules against the bridge-
wall, spattering back and burning on top of the fuel bed.
If fed too fast it builds up into a large mass which has
often nearly filled the firebox. It will also run down
into the fuel if fed too fast, and make a hard clinker in
the grates.
In connection with the plant there is a sawmill which
delivers the sawdust and refuse from 7000 ft. of lumber
r; — J~~;
'——— - i S
U o
\i "
° Finn fr c
;=1_±zr.^^_ 1 ^==
Connections at Furnace Burning Solid. Liquid and
Gaseous Fuels Simultaneously
a day to the boiler room. It is dumped into a bin by a
chain conveyor and shoveled by hand into the fireboxes.
When too green and wet to burn readily the sawdust is
sometimes mixed with coal before firing. It is the practice
to fire the sawdust all into one firebox; this is, of course,
wrong, for since it is a much inferior fuel to the coal
and the grate areas are the same, it follows that the two
boilers fired by coal are overloaded, while the one fired
with sawdust does not carry its share of the load.
As til.- waste fuels do not furnish the necessary heat
for all steam making, it is necessary to burn large quanti-
ties of fine pea anthracite coal on the grates. These fires
must be raked off the grates periodically, and in kindling
the new fire quantities of charcoal screenings are used.
These screenings are a more or less waste product, and
make excellent kindling. It is necessary to shut down the
dampers when they are on the grates, to prevent them
from blowing tip the flue, they are so light.
The careful engineer will doubtless see much room for
improvement in the arrangements mentioned, but owing
to the extremely conservative spirit in the industry it
is difficult to try out innovations; the coal bill is regarded
as a necessary evil and, apparently, no further thought
given to it.
The Simplex emergency jack, recently placed upon
the market, is a tool of usefulness and utility
wherever there are loads to be lifted or pushed. It
practically combines a crane and a jack. The accompany-
ing illustration shows the jack acting as a crane in
changing the location of a boiler, wherein pushing at an
angle and lifting are necessary.
The standard is a heavy malleable-iron casting ribbed
for stress in every direction. The circular bottom of
Jtine 22, I'M
P 0 \\ E R
si;
the frame rests with a machine lit upon two circular
shoulders, which are a part of the largo, well-proportioned
base. In this way the base takes the load, and the steel
pin aets to hold the frame in position. The rack bar
and cap are heavy drop-forgings. The top of the cap is
recessed for the chain, which is a part of the equipment.
The double socket of crucible steel makes it possible to
Simplex Emergency Jack
handle a load with the jack at any angle. A heavy trun-
nion bearing supports the socket. The working angle
of the jack is from 30 to 90 deg. to the horizontal. The
trip at the back of the base either holds the frame in a
rigid vertical position or releases it to pivot on the base.
Five feet of chain and a 5-ft. steel lever bar comprise
the equipment. The jack is manufactured by Templeton,
Kenly & Co., Ltd., Chicago, 111.
A M©siae°Msidle Cooliim^ Tower
By A. D. Williams
An expense often overlooked in the operation of a gas
engine is the cost of cooling water. This is particularly
the case in city installation- where the local water-supply
is the only one available and meter rates must be paid.
J. F. Kalb, chief engineer at the factory id' the Willard
Storage Battery Co., Cleveland, Ohio, was confronted
with a problem of this kind several years ago. As the
size of the power plant was increased by the addition of
new engines the water bill increased until it was about
$2300 per year, a part of the water being used in the
factory, but the larger portion in the engine jackets. Mr.
Kalb suggested that a cooling tower upon the roof of
the engine room would enable him to use the water over
and over again instead of wasting it to the sewer, and
finally, be was authorized to build the cooling tower
shown in Fig. 1, which was made entirely in the com-
pany's factory.
The base of the tower is a lead-lined sump or tank about
•VxKi ft., supported on a rack upon the roof and deep
Fio. 1. General View of Tower
enough to hold a foot of water. This tank is provided
with an overflow to limit its water line and a ball-and-
tioat valve to admit make-up water as required. The
use of sheet lead avoided the necessity for making water-
tight joints in the woodwork which might have been more
troublesome. The bottom of the tank was built as a
lengfodmalQA^
Slats
Pig. •.'. Details of Tower
platform, with heavy battens on its under side, and the
sides rest on the platform and are supported by brackets.
The joints in the lead lining are burnt, not soldered, and
pipe connections arc made to the lining by brass flanges
soldered to it.
Above the sump there are nine trays about a foot apart,
supported by posts that rest on the bottom of the tank.
848
I'd \\ E K
Vol. 41, No. 25
the lowest tray being 8 in. above the sump. These trays
are 1 in. deep and slightly smaller than the tank, their
bottoms consisting of racks made up of 1-in. slats cross-
ing at right angles and so arranged that the openings in
one tray are not below the openings in the traj above.
Water is delivered through a manifold and pipes to the
top tray and to the fifth tray from the bottom, the latter
arrangement being for use in cold weather. As original-
ly planned, wind-shields were hinged to the top of each
tray so that the windward side of the tower could be
closed to prevent the spray being blown out on the roof.
In practice, however, it was found that these shields
became coated with ire ami could not lie closed in cold
weather, except with difficulty. The construction of the
trays is shown in Fig. '2.
The cost of this cooling tower, including erection, was
slightly under $500, ami the first year's operation showed
a water bill of $300— a reduction' of $2000 from that of
the year before. This reduction in the bill caused the
water department to test the meter used, after which the
accuracy of the bill was not disputed.
§uapp©iHtlim§| M©ira20Eaft®s.E IR©tbiaE*in\=>
Ttmlbtfflllsiip IBoIllers
By F. W. Dean
The manner of supporting horizontal return-tubular
boilers is of considerable importance. Such boilers should
be supported at no more than four points — on both sides
Rear Supporr.^ r~\
Support.. I a r.v 'IV^^-j-j
American Society of Mechanical Engineers in 1898 and
published in Power in November of the same year. If
one end of the boiler is supported by two of the usual
brackets, one on each side, or is suspended from above
by two rods, one each side, and the other end is supported
by two rods from above, one on each side, and connected
to a hinged equalizing lever, the three-point principle is
realized. When this is done the pressure on the brickwork
and the strains in the supporting parts never change, even
if the brickwork settles. If, instead of having an equaliz-
ing lever, the rear head were connected to an overhead
beam by means of a hinged joint, the same principle would
be applied. This may be a simple and good way to earn-
out the principle.
If it is doubted that a boiler can stand the strain of
being supported at the ends, by treating it as a girder and
knowing its weight when full of water, it will be found
that the strain in the shell is next to nothing, and it will
be seen that this method of support is safe for almost
any horizontal boiler which is otherwise properly designed.
In practice the case is not as bad as that just suggested,
for the points of support are never at the extreme ends,
and they can be so chosen that the boiler becomes a well
proportioned continuous girder over the points of support,
thus reducing the shell strains to a minimum.
Another feature of the usual method of supporting the
type of boiler under consideration that merits criticism,
is the design of the brackets. While I never knew of the
brackets breaking or pulling away from the boilers, they
PLAN OF
rear end equalizer
Reab Ends of Boilers Suspended from Equalizers
near each end. If a boiler is of much length some build-
ers support it at six points. Having an intuition that it
is doubtful if the different supports will carry equal
weights, they sometimes place springs under the middle
ones, thus making the supports somewhat flexible with-
out removing the uncertainty. This is only a makeshift,
as even with the use of springs the inequality of support-
ing pressures is as great as ever.
It is a principle in mechanics that if a body rests on
three points the pressure at each point can be determined,
and will not change. A three-legged stool always rests
properly on its legs ami with unchanging pressure, even
when it rests on an irregular floor; but a stool with more
than three legs rarely presses equally on each, and if its
feet were carefully fitted to bear equally on an ordinary
floor, a little change in position would destroy the tit-
ting. This illustrates that in supporting a horizontal
return-tubular boiler the three-point principle should be
applied. This, I believe, was first done by Orosco C. Wool-
son, and by him made public in a paper read before the
should be designed with a row of rivets below the horizon-
tal part that rests on the brickwork, thus reducing the
stress on the bracket rivets.
The illustration shows how I have carried out the Wool-
son three-point principle since 1899. I first used it for 90-
in. boilers for S. D. Warren & Co., but the illustration is
that of some 78-in. boilers for Walter Baker & Co., Ltd.,
at their Montreal plant.
The Holding Power of Tubes, as shown by a series of tests,
is given by J. II. Allen as follows: Tubes expanded but not
flared or beaded, 5000 to 7500 lb. pull; tubes expanded and
ends flared, 19,000 to 25,000 lb. pull.
Pipe Corrosion — In an effort to settle the important and
mooted question as to which material better resists the ac-
tion of corrosion, the National Tube Co. fpr years has made a
practice of shipping with steel pipe wrought-iron couplings,
so that the corrosion of each material could be judged by
comparison under the same conditions of service. As a re-
sult they have concluded that there is no doubt as to the
advantage of steel pipe and have abandoned the manufacture
of charcoal and puddled iron for welded tubes.
June 22, 1915
P ( > W E 1!
849
i; ' -
:m iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
llllllllllllinilllllllllll I llllllillll Ill It
WesiM §p©£§ nsa Hydlyo-IiDILceettiric
Recent studies of water-power development for electric
transmission disclose the need of broader operating
knowledge in some instances, in order to realize the high-
esi possible plant efficiency and the safes! running con-
ditions. Foresight in development cuts a greater iigure
in hydro-electric plants than almost anywhere else, in
view* of the costliness of changing such installations once
they are completed. Both on the mechanical and the
electrical sides improvements are desirable, as the fol-
lowing typical points illustrate.
Consider the problem of utilizing the available head.
In this connection plant location is of decided impor-
tance, requiring thorough study by engineers of experi-
ence in oiiler to avoid sacrificing a portion of the water
drop which can be utilized easily without undue increase
in investment. In one plant with a thirty-two-foot head,
the available fall on the turbine runners might have been
increased to forty feet had the station been located a
couple of hundred yards down stream, and the output
could have been increased accordingly, with still less ser-
vice required of the auxiliary steam plant. The operat-
ing engineer in charge of the station pointed this out
to a visitor familar with such work, and it was seen that
the contention was true. The case was one where the
company might have saved many thousands of dollars a
year had its preliminary plans been shown to the oper-
ating staff for criticism. The adoption of the engineer's
suggestions was in no sense obligatory, and there could
have been no cause for dissatisfaction had the manage-
ment decided, in the face of all the information before
it, to proceed along the lines which it actually followed.
Failure to realize the full possibilities of such a situa-
tion, however, is a misfortune, for day and night there
is a loss of head below the tailrace in this station which
might well have been turned into the wheels and made
to earn revenue for the company.
Men who have to run plants of this kind realize the
value of adequate hydraulic arrangement, including pro-
vision for getting at the rear bearings of turbine sets
and ample sluice gates at the dam and forebay, so that
the requirements of drainage can be met properly. Now
and then only partial provision is made for emptying
the forebay or for the removal of trash and leaves from
the screens at the intakes. Ample lighting facilities
here are as important as in the generator room itself.
In one recently completed station a space of six feet
wide has been set aside for reaching the rear bearings
of the water-wheel unit.-: and this, illuminated by a
special circuit of tungsten lamps, means real comfort
and resulting efficiency for the staff. It costs something
in additional masonry or concrete to provide such a
space, but in case of trouble, accessibility of such bearings
is a valuable feature.
On the electrical side two points that deserve more at-
tention may be emphasized. One is the practice of
crowding too much switching and auxiliary apparatus
into a limited space on a switchboard gallery, and the
other is the need of better mechanical structures to sup-
port outgoing transmission and feeder lines. In one
instance where the station design was studied in the
light of operating experience, the potential transformers
for various instruments were mounted on a frame above
a concrete bus structure containing oil switches. The
designer of the station probably never gave a thought
to the danger of replacing fuses on these transformers
in sin li a locution, close to busses carrying high-tension
energy and reached only by planking carried on pipe
framing above the switch compartments. The fuses
may he replaced with tongs, but nevertheless the posi-
tion from which the operator must work is perilous, and
had the designer consulted with men experienced in ac-
tually handling the type of plant in mind, it is prob-
able that an entirely different location for the trans-
formers would have been found.
X
^Easiairaees's sumo
ises
One of the engineer's worst "good friends'' is the sup-
ply house which takes hack the articles he claims defec-
tive and replaces them without investigating whether the
article was originally defective or ruined by misuse. This
method of handling claims encourages an engineer to
become more careless in his work and works a hardship
on all concerned.
The supply houses, and their representatives, are
great factors in educating the engineer, hut if lax and
careless in their business transactions he will gradually
become the same in his work. For example, in place of
catching the hexagon on the bonnet of a brass valve in
the vise, then screwing a piece of pipe into the valve and
using it as a lever to loosen the bonnet, he will catch the
lody of the valve in the vise and try to loosen the bonnet
with a monkey- or perhaps a pipe wrench. Then, when the
body slips in the vise he will tighten it up and squeeze
the seat out of shape, and the valve will leak. This may be
cither ignorance or carelessness, but it makes no differ-
ence, he says the valve is defective and returns it. In
order not to lose the business the supply man replaces the
valve without a word and junks the ruined one.
How much better for all concerned it would be to take
the valve back to the engineer, show him how it had been
ruined and how to take it. apart, and make him pay for it,
as he should. Nearly all manufacturers test their valves
before leaving the factory, consequently they have a right
to look with suspicion on complaints regarding leakage
through the seat.
Some time ago an engineer claimed that three auto-
matic stop and cheek valves were leaking and didn't open
as they should when cutting in a new boiler. They
were taken apart and found to be covered with mud, which
caused all the trouble. The engineer should have taken
these valves apart himself before making complaint.
850
POWER
Vol. 41, No. 25
In another case, where a gate valve was placed in the
header between two engines, the first time it was closed
it "leaked like a sieve," and complaint was made. An-
other tested valve was sent, and this likewise leaked. An
experienced man was sent, and he found that the expan-
sion in the pipe Line was springing the body of the valve.
The piping was rearranged and the trouble disappeared.
In a new pipe line there is always a lot of pipe scale
cuttings, etc., that may lodge in the valve the first time
the steam is turned on.
Returning material to obtain new when you are not
justly entitled to it is dishonest. You might just as well
break into a place of business after nightfall and take
what you want. Besides, we pay the bill in the long run.
DetfSimM© Em\.gpm\©©rii?n§| IEdlnacaftioEa
Attendance at commencement exercises this month
brings many rewards to those fortunate enough to hear
the distinguished speakers from far and near, but there
is one striking consolation for the man who must stick to
Ins daily task while others loll about the campus and
drink in good advice in the auditorium. That is the
eternal value of scientific principles, both pure and ap-
plied, as a mental resource and stimulus to the individual.
Thousands of words have been spoken this month upon
the subject of technical education and its relation to mod-
ern industry. Much of this has been interesting to hear,
but a large part of it has been self-evident, with remarks
of scarcely more than a commonplace value to the engi-
neer, be he graduated from the school of experience or
from the university of books and laboratories.
We have no quarrel with present methods of engineer-
ing education, but we do wish to emphasize the surpassing
value of concrete studies in contrast to the ocean of gen-
eralities poured forth by many commencement speakers
at this season. Some of these men rose to the occasion and
drew appropriate lessons for the engineering profession
from these epoch-making days in the world's history.
Others — well the feeling of many a man after sitting
through some of these exercises is one of thankfulness for
the solid interest and profitableness of definite engineer-
ing principles and problems as a field for putting forth
one's best powers of thought and expression. Those of us
in, or closely allied with, engineering work can rejoice that
we do not have to spend three-quarters or more of our
waking hours groping about in the fogs of speculative
theory which beset the footsteps of so many "educators."
How much more interesting it is to stop leaks in the plant,
to figure out a method of utilizing more heat units be-
tween the turbine-discharge outlet and the feed pump, to
rectify a poor valve setting on the basis of a skillful
indicator diagnosis — yes, to master the situation in deal-
ing with that oil salesman, or to make the boss's jaw set
with satisfaction in showing him an exceptionally good
report of station performance!
A man may have gone hack to his Alma Mater this
vear to celebrate some notable anniversary in his life, and
yet he may have come away and gone straight to his job
again with greater enthusiasm than ever for the principles
on which his work is based and greater interest in its
puzzling difficulties. He may have been given inspiration
for taking up regular work again by speakers of interna-
tional fame, or he may have been driven back into his own
thoughts by the skill with which titled and ''degreed"
orators enunciated the perfectly obvious. However it may
be, there is not the shadow of a doubt that one of the
greatest blessings about working in the engineering field,
with all that it implies in self and cooperative education,
is the necessity of definite aims, of striving toward some
concrete attainment. The lasting opportunities before the
engineer for the mastery of specific principles and prob-
lems put the hypotheses and assumptions of people less
accustomed to deal with realities far into the background
as objects of tangible achievement.
It is always gratifying to see a college or university
with a decidedly practical trend. More and more is this
becoming the spirit of the modern educational institu-
tions, as contrasted with the learned, but not always use-
ful, reputations which they once held.
The Oregon Agricultural College is making a first
attempt to carry its engineering instruction out to the
people of the state. During the past three months
lectures and demonstrations have been given to the Port-
land branch of the International Union of Steam Engi-
neers, with an average attendance by the members of over
one hundred and fifty. In addition to the lectures,
demonstrations have been carried on at various plants
in the city, and a number of experiments and exercises
have been conducted by individuals interested. One
typical instance resulting from this instruction was a
saving of eight per cent, in the cost of fuel in one of
the largest plants in Portland.
The subjects taken up this year were "Combustion
Control" in connection with the operation of heating
plants, and "Refrigeration." This work was given by
Prof. P. H. Rosencrants. There was also one lecture
in "Electrical Engineering," by L. F. Wooster. The
work proved so successful that it will probably be carried
forward on a larger scale next year, according to a re-
port of Prof. P. I). Iletzel, the Director of Extension.
While we do not wish to see the spirit of the age too
commercial, real efficiency as measured in dollars and
i cuts i-. alter all, the one for which it pays to strive, and
if tin' colleges (,ui teach us how to cut down the fuel ex-
pense in our steam plants eight per cent., it behooves us
to give them an audience.
Of course, it does not follow that the savings will be
general or that they are always possible. There are many
engineers and steam-plant operators who could teach most
college professors a great deal about economical combus-
tion. At the same time, the college professors may have
come from the ranks and, through the school of experience,
know something about firing themselves.
m
There is a letter by one of our esteemed contributors
on page 852 id' this issue that nearly all should read —
assistants as well as chiefs. It is about wage increases.
Assistants should read it because it will reveal to many
what the chief is "up against" when he tries to increase
the wages of his subordinates. Chiefs should read it
to either remind them of, or acquaint them with, the
things they should consider before attempting to add to
the payroll burden. Employers realize more and more
that good wages attract high-quality labor, and most of
them will increase wages when convinced i^ is deserved.
But none will make weekly or monthly donations.
June 22, 191.'
po w E i:
851
. '... . . ■ ;,i.n:i:i:n . i: .:'... ., ,■■■! .,■ ■■■!,! ■
Coinrespomidleinice
On starting up a small belted generator that had not
been in use for some time the bearing on the commu-
tator end ran hot. The operator, thinking the bearing
might be pinching, put liners between it and the cap.
Then the bearing got hot
quicker than before. When
the cap nuts were loosened
slightly with the machine
running, the shaft was Been
to rise out of the bottom
bearing and follow up the
cap; and the bearing got hot
very quickly. This indicated
that there was an unbalanced
magnetic pull on the arma-
ture.
An examination showed
polepiece A to have a smaller
air gap than B, C and D, which were all alike. There
were a few shims back of the polepieces and by removing
those back of .4 the air gap under A was equalized with
those under B. C and D. The cap was then put back
on the bearing without any liners and pulled down
tightly, and the bearing did not go above a moderate op-
erating temperature.
Showing Unequal Air
Gap
D. X. McClinton.
Pittsburgh, Penn.
In a recent issue of one of my engineering magazines
I noticed under the heading of "Court Derisions,"' the
following statement concerning child labor in Alabama :
Under a law enacted at the present session of the Alabama
legislature and approved by the Governor Feb. 24, 1915, it
becomes unlawful to employ any person under 16 years of
age in operating or assisting in the operation of any steam
boiler or dangerous machinery.
This evidently is a first >tep (and a rather weak one)
in the right direction, for which the engineers in that
state should be thankful, but if the law has only reached
that stage where children are prohibited from acting in
the capacity of engineers, then the engineers of that state
a long, hard road to travel before they can expect
to get a safe and Bane license and boiler-inspection law
and the recognition which is due their position.
It is my opinion, and I believe that there are many
others who will agree with me, that children of 16 year-
should be in school. Certainly, the work and responsi-
bility of operating a -team boiler and engine should nol
be intrusted to a child.
In Alabama there are comparatively few boilers as
compared with Massachusetts and other manufacturing
states, and probably for that reason sufficient pressure
has not been brought to hear to put through a reasonably
safe law in regard to the operation of power-plant
machinery. When we consider that Massachusetts, with
its present rigid laws in regard to the construction,
inspection and operation of boilers and examining and
licensing those who are to have charge of them, is nol
satisfied with its present laws, and is trying to enact more
adequate and in some instances more rigid ones; that
Ohio, which now has rigid boiler-inspection and engineers'
license laws ie about to adopt the new regulations as
proposed by the A. S. M. E.; that Wisconsin has already
adopted these laws, and some other states and muni-
cipalities are contemplating the same step — it does seem
that the present situation in Alabama is many years
behind that of the other states.
These facts bring out the question, Are the boilers in
Massachusetts, Ohio or \\ isconsin more dangerous or the
men as a rule less proficient than those of Alabama and
some other state- where there are no inspection and license
laws? It is probable that the reverse is the case. Is
there any right-thinking employer in any of the states
which have any semblance of inspection and license
laws (no matter how opposed he may be to the present
laws of his state) who will admit for a moment that a
boy of 1G or 17 years of age is a competent person to
have charge of his engines and boilers? I think not.
He may be satisfied to have these lax laws by means of
which some other employer may hire the boy, and thus
make it possible for him to get a man at boy's wages.
Then there is another phase of the subject which
appeals to most employers, aside from the safety of the
plant, and that is efficiency. It is well known that it
often lies within the power of the engineer to regulate the
cost of producing power. For this reason the progri
employer insists on having a man of mature knowledge,
judgment and experience in the power plant, to say
nothing of a 16-year-old boy who cannot possibly have
acquired these qualifications.
It seems to be the aim of some of the employers in some
of the states where the laws in this respect are rather
lax or where there are none at all, to vigorously oppose
legislative bills that come up in regard to boiler-inspect ion
and license laws on the grounds that they are unnecessary
and will cost them more money through the engineer's
being able to control the supply of engineers to some
extent, and of the necessity in some cases of getting
other men. They can only see the almighty dollar that
they may have to pay for the services of a competent
man. to one who has to prove to an exacting board of
examiners that he is competent to safely and efficiently
operate this class of machinery before he is allowed to
have charge of it. But they lose sight of the double
that will conic to them through the more efficient
of the plant by the man who can prove thai
he has the skill to do it.
As time 2 laws that govern the requirements
of engineers become more exacting, and the employer,
realizing the importance of the engineer's position,
demands more efficiencj in this department, and only
those men who are persistent in their efforts to improve
852
P 0 W E B
Vol. 41, No. 25
their conditions and who are willing to work conscientious-
ly for their employer's interests, will succeed in holding
the best positions in the engineering field,
J. C. Hawkins.
Hyattsville. Md.
ss
The threads on one plunger of a geared triplex pump
gave way at the point where it screwed into the crosshead.
In order to keep the machine running, the disabled
plunger, crosshead and connecting-rod were removed and
the cylinder closed, as shown. In the illustration A is the
sq. .
Plunger Removed and Opening Capped
plunger packing, which was not removed, B is a rubber
gasket covering the opening in the end of the cylinder,
C is a piece of sheet metal under the gland D to rein-
force B. When these parts were assembled and tightened
down, the pump was kept running with the two good
ones until a new plunger could be made to replace the
disabled one.
The construction of the plunger and crosshead is shown.
in which the plunger screws into the crosshead which is
cylindrical and runs in a bored guide.
Earl Pagett.
Coffevville. Kan.
used to case oil' a bit more than they can today. Any-
how, it's Bill's job to know his men, and so long as the
kilowatt-hour expense goes down, I'll back him in sharing
the profits with the men."
This is not the kind of manager with which some engi-
neers have to deal, as is shown by the following questions
asked in a recent case where the chief thought his men
ought to have a further advance in pay because of their
faithful work, their punctuality, willingness to see the
boss through any troubles and increasing familiarity with
the service requirements.
""The work lias not changed or increased since the last
raise, has it!' The men have had frequent raises in pay
in the last decade, haven't they? Do you recall any class
of men in your station that did not share in the previous
increases? The hours have been reduced, have they not?
Can you point to any specific increase in the men's effi-
ciency since the last raise? Does the mere fact that your
firemen understand English better justify this company
in giving them more money? How many men have you
today in this plant that were not on the payroll at the time
of that last increase? Were not the men just as busy
then as now '? Have you any more or different machines
now? Has the output increased enough to make it per-
ceptibly harder for any man to do his daily work, and have
you had to hire any more men to meet this condition?
What sort of repair jobs have come up that have been
handled quicker than before by the men as the result of
their greater familiarity with the station and at how
much less cost? Don't you pay the 'going rate' of wages
in this station ?"
By this time the engineer is likely to be reduced to a
point where a reply is impossible unless he has anticipated
just such objections. There is no use in considering the
manager as a leather-hearted tight-wad, for he is only
trying to protect the investor, although sometimes protect-
ing the investor and sharing the profits may be parts of
the same policy.
H. S. Knowlton.
Cambridge, Mass.
sag a JPressiaire
map
It sometimes falls to the lot of the chief engineer to
approach his superior relative to an increase of pay, not
for himself, but for the men of the plant. The task is not
an easy one at best. Many a plant owner or manager who
is personally a good boss to work for finds it necessary to
put such requests "on file." Unless an engineer can show
his superior why it will be good policy to increase the
existing wage outlay, he will do well to refrain from ask-
ing for it.
Hard-headed business men do not increase wages with-
out good reason. The engineer must never forget that
to the man of affairs the power plant is usually incidental,
and it is a mistake not to appreciate proportion when seek-
ing to add to the payroll. The faithful work of an engi-
neer through many years makes the presentation of recom-
mendations a fairly easy matter so far as the continuance
of friendly regard goes. "Bill says the firemen ought to
have 15 cents a day more." says a manager of this kind,
"and I guess he's right. He has been cutting the unit fuel
cost 10 per cent, in the past six months. He tells me
the peak is broadening and that we now have to run No. 6
and Xo. 7 boilers through the noon hour, when the boys
Some time ago we installed a large pump to maintain a
pressure of about 2200 lb. on the rams of a number of
hydraulic presses. The accumulator on the line between
the presses and the pump was weighted by building a
cement block upon it. Subsequently, it was found that
the weight was insufficient, and after some careful figuring
the fact was brought out that it would be necessary to
remove the whole cement block in order to get room to
put mi the pig-iron weights that our pressure called for.
This looked like a big and expensive proposition, so I
advised running without an accumulator. This was ob-
jected to by the superintendent, and to my surprise the
pump agent sided with him, but later they told me to
go ahead and try it. I am pleased to say that after a
year's operation in this way. the pump is giving good
service, and I have less trouble with it than with its mate,
which is attached to an accumulator.,
I calculated that 88 lb. pressure per square inch, acting
on the 10-in. steam piston (having an area of 78.54 in.),
exerted a total pressure of 6911 lb.; operating a 2-in.
plunger on the water end against 2200 lb. per sq.in. would
June 22. L915
POW E B
853
jn-1 balance. It was therefore necessary to raise the
boiler pressure slightly to overcome friction.
This pump is of.the single-c] linder t\ pe, and we experi-
enced no trouble with it until about two months ago,
when the pressure tell a1 each stroke, and as a uniform
and constant pressure is called for in our work, it was
necessary to find the cause. The piping and joints were
examined for leaks, the packing was renewed, the valves
in the pipe lines were tested, and the pump valves were re-
moved and inspected, hut still the pressures varied. 1
decided that the trouble lay in the discharge valves, but
was unable to see what it was.
On Sunday I thought it would not be amiss to give
the valves a little grinding, although they did not seem
to need it by any means. The next morning the pump
acted much better and the variation in pressure was
much less. Here was the cause, ami a very small cause
it was at that. Since then I have made a thorough job
of the grinding, and the pump is giving splendid ser-
vice.
While grinding does not appear to change the surface
of these valves, results show that it does. I believe
grooves are caused by the action of the water under high
pressure, and while they are not to be detected by the
eye or touch, under a glass they are easily seen. Engineers
who have not had such experience will be surprised to
know how rapidly water under high pressures can get
through minute holes.
A. D. Palmer.
Dorchester, Mass
:*■:
Reinxewnir&g> Puasimp) PEsunagfeirs
The illustration shows a method of renewing the
plungers of an outside-packed plunger pump. Those
furnished by the manufacturer are of cast brass, the
shell being from 14 to V2 in. thick, according to the size
of the pump and the working pressure. Fig. 1 shows
the original plunger and Fig. '.' the new one. The beads
A and B were cut off, turned and threaded as shown in
Seat
*—■
■
Pump Plunger M ide of Pipe
Fig. 2. The shell was replaced by a length of extra-
heavy seamless bronze pipe, seated and threaded to take
the heads .-1 and B.
The cost of the newr plunger, including material and
labor, is one-half that of the one furnished by the manu-
facturer. This difference in cost is i\m' to the fact that
in making the castings there is always difficulty in keep-
ing them free from blow-holes, and another irregularity,
the shifting of the core
The life of the cast-brass plungers does not in any
way compare with those of seamless bronze pipe, and
when the latter is worn down, it, is only necessary to
replace the shell,
Herman Fiebig.
Brooklyn, N. Y.
Referring to the article bj I-'. F. Jorgensen, on the sub-
ject of erankpin failures in the issue of May 35, on pane
720, I consider that the pin was not large enough in
diameter for a cylinder of the size given ("'4 in.). There
is an approximate moment of 2y2 in., therefore,
55,000 X 2M2 = 137,500 in.-lb.
The section modulus of t^-in. diameter equals 0.98 X
4l/23 = 8.91, say 9.
138,500 -=- 9 = 15,278 lb. stress per sq.m. of pin.
This is too high a stress for such work as hoisting. The
normal stress should not be more than half of this, say
7000 lb. per sq.in.
The fillets are good and should be on all such pins.
A still better design is to countersink the collar in the
crank from one-quarter to one-half inch, and more where
possible. I would suggest that a larger pin be made and
put in before another accident occurs, because a larger
pin is really necessary, and no doubt the erankpin box
is of such design that the bore can be somewhat in-
creased.
R. G. Cox.
Cleveland, Ohio.
The addition of fillets is undoubtedly an improvement
on the old pin that failed, but the main trouble is that
the pin is too small for the load. The information given
indicates that the maximum pressure upon the pin Was
54,000 lb. and the liber stress in the pin at the point
where it broke was 15.100 lb. per sq.in. As the stressf-
ul a erankpin occur twice in each revolution, it is nec-
essary to use a low fiber stress, generally between 8000
and 12,000 lb. per sq.in., according to the grade of
steel. Assuming a fiber stress of 9500 lb. per sq.in., the
new pin should be 5% in. diameter. Heat-treated or
alloy steel may. of course, lie subjected to higher stres 1
The impact load is sometimes very high, and this is an
added argument for designing the rods and pins of such
engines for low fiber stresses.
A. D. Williams.
Cleveland, Ohio.
It is evident that the absence of a fillet contributed
nun h toward the failure. In locomotive practice, failures
occur even with liberal fillets. I recall a series of pin
failures on 18x2 1 -in. eight-wheel engines on a .Middle
V esi railroad at one time. The engines were some eight
years old at the time, ami well cared for. The back pins
binke off just inside of the pin hub, and the fractures a
a rule resembled the illustration shown on page 720,
May 25.
The principal part of the fracture was toward the
center of the wheel, a smaller break was on flu- outside
of the pin, and the pin hub was chafed bright for one half
to three-quarters of an inch in from the face of tl
hub. indicating a bending of the pin for some lime prior
to fracture. The face of the fracture being quite smooth
at th tside of the pin and gradually becoming coarser
S54
P 0 W E R
Vol. 41, No. 25
toward the place of final rupture, shows the characteristic
fracture of the material of which the pin was composed.
The original wrought-iron pins were replaced by either
wronght-iron or forged steel in different engines, but
both of the new kinds broke, some in as short a time as
six weeks. They generally broke about, one-quarter to
one-third of the pin's diameter before the final rupture
took place.
Alter the failure of the new pins of the same size as
the original, the pin hubs were bored one-quarter inch
larger and case-hardened pms of Low Moor iron were put
in. There were no more failures for about a year after-
ward while I was working there. The cause of the
fractures was evidently due to the thrashing of the rods
at high speed, although on that type of engine we did
not have any trouble from breaking main pins, notwith-
standing they carried the tw~o rods and had the piston
pull to reckon with. On another road I saw a number of
main-pin failures, and the fractures showed the same
general features.
When the brasses are removed, a coating of white-lead
paint on a freshly wiped pin will disclose cracks, the
paint becoming discolored by the oil in the cracks.
However, this test will be of no value where the fracture
is within the pin hub.
C. W. Hayxes.
Koine. X. Y.
Cesatrifoa^Sil Puasiap Beeavsrm© Aair
Houses ell
The centrifugal pump .4 draws salt water from the tank
B, through 590 ft. (400 4- 92 + 98) of 12-in. pipe.
When the machine is stopped there is about three pounds'
pressure on the suction side at the pump.
The pump discharges through line CD into tank E.
The latter supplies salt water to the condenser M through
0
TANK[ ]£
CONDENSER
* A j
PIMP.; | 1
J !
^ !
ii
400- ^
Piping Diagram of Pump. Condenser and Tanks
pipe UK; F is an overflow pipe. This was intended
to eliminate hand regulation of the pump discharge;
if the quantity was too great it merely overflowed from
the tank back through F into the suction of the pump.
However, the water flowing back through F sucked in
air. This was drawn through F into the pump, causing
it to become air bound, and it would deliver no water.
Another thing contributing to the air binding was the
fact that when the pump was working up to capacity
there was a vacuum of about 15 in. at its suction due to
the friction of the 590 ft. of piping. When this vacuum
exceeded the head due to B(l, air would be sucked in
through the pipe F.
The above conditions were remedied by doing away with
tank E and pumping directly to the condenser through
pipes CHE (shown dotted) regulating the capacity b\
means of valve A".
Frank McMoreow.
Xew York City.
&;
Power-plant men usually have a hard time cleaning
their hands. At our place we keep a supply of fine sand
by the sink, which we apply to our hands after soaping
them well. This takes the grease off without injuring
the hands. I have always been troubled with chapped
hands in the winter, but scouring them in the sand once
or twice a day overcomes this trouble.
J. 0. Bexefiel.
Anderson, lnd.
m
£km U'lnmssmsiJ PSsHoks F^iluas5©
In the issue of May 18. page 689, J. W. Dickson
describes a unusual piston failure and asks to hear from
readers who have had like experiences. A similar accident
was related in Power about five or six years ago, and since
then this has occurred twice in the plant of which I have
iharge. Both were in 22-in. pistons on low-pressure air
compressors of different make. In neither case was any
damage done to the compressor. In the first the damage
was repaired in the way described by Mr. Dickson; in the
second a new piston was required, which the builder
supplied without charge.
No time was lost in finding the cause of the pounding,
thanks to the article in Power, which was fresh in the
writer's memory when the first failure occurred. The
trouble in each case was due to core iron (used to stiffen
the sand core ) being left in the piston when it was cleaned.
this cleaning out of the core being a difficult matter on
account of the small opening provided for the purpose.
The pounding was caused by the increased clearance
volume.
P. L. Werxer.
McKeesport, Penn.
One morning a number of years ago. a sudden loud
"thump" inside of our 16x36-in. engine shook things up
pretty well. The chief shut the engine down promptly,
took off the cylinder head and found that a nut from
one of the adjusting bolts between the bull ring and
piston had worked off and worn a hole through one
bead of the piston and nearly through the other. These
places were drilled out and plugged, after which the en-
gine ran as well as ever.
Later we had an experience on a condenser pump sim-
ilar to that described by Mr. Dickson and repaired it in
the same way.
\Y. u. Perkins.
Bristol. Conn,
June 22, 1915
POWER
855
We had a very similar accident with a straight-line
steam compressor. The piston in the steam end was of
the built-up type, and two of the centering capscrewe
worked loose. One wore through the follower plate
(which was one inch thick), fell out into the crank end
of the cylinder, and broke the follower plate. A new
cored piston was cast and put in place of the built-up
type, and the compressor has since been running very sat-
isfactorily.
P. F. Oates.
Santa Barbara. Chili., Mexico.
The illustration shows a safety or danger sign used
in our plant. When the men go to work on shafting or
belts they are instructed to hang this sign on the throt-
DANGER!
MEN WORKING DN
5HAFTINB
Metal Danger Signal
tie valve and waterwheel gate as a warning to the engi-
neer and others not to start any prime mover, and even-
man working on the job must sign his name on a pad
near-by. When he has finished with his work he must
cross out his name and the last man off the job is to
take the sign or signs down. Our danger sign is 8x23
in., made of galvanized iron painted with aluminum,
with a red border and red letters.
A. D. Skixnei:.
Chadwiek. X. Y.
I was called upon recently to repair a motor that had
met with a rather unusual accident. It was a 100-hp.,
three-phase, 440-volt machine operating a gyratory
crusher in a rock quarry. Heavy rains had caused a
slide, and a rock had fallen from the quarry face through
the motor room, breaking one of the leads to the auto-
starter. This caused the no-voltage release to act, cut-
ting out the motor at the auto-starter. A greater mass of
rock was loosened by the first slide, and about five hun-
dred tons crashed through the motor room, covering the
motor entirely. In a short time smoke was seen coming
up through the debris, and someone cut off the power at
the quarry substation. Upon uncovering the motor, it
was found apparently uninjured, but the auto-starter was
seen to be in the "starting" position. Upon test, the mo-
tor showed forty badly burned coils.
Investigation showed that the first slide had cut out the
motor safely, but the second slide (only a few seconds
later) must have struck the auto-starter handle so as
to throw it into the '•starting" position, and to wedge
it there. The motor could not start for at least two rea-
sons: First, because one lead had been broken by the
first slide, leaving the motor on single-phase; and sec-
ond, because the machine was blocked by the rock from the
second slide. The auto-starter was so wired that there
were no fuses on the starting side, and the substation
fuses were too large to relieve the motor, so it had to
stand with the one phase hot, causing damage to forty
coils. The auto-starter was uninjured.
The worst coils were cut out, and the others repaired
so that the motor was put into commission 14 hours
after the accident.
D. D. SlIALLEY.
Bagley. Calif.
m
Saffa^le^Uiniatl Powe? PE®.!nifts
A short time ago the writer was asked to investigate the
proposition of installing a municipal electric-light plant in
a small town, and after determining as nearly as pos-
sible the probable load, it was decided that the conditions
would warrant the installation of two 75-kw. units.
Several types of plants were considered, but the one
which attracted special attention was the proposal to
install a 125-hp. anthracite gas producer and a 100-kw.
generator, to which would be connected two 2-cylinder gas
engines of TO hp. each, one on either end of the generator
and connected thereto through a clutch. The principal
advantage claimed for this arrangement was that, the gas
engine being uneconomical at light loads, either engine
could lie used separately when the load was light, thus in-
creasing the load factor toward the most economical point.
Then, as the generator load rose above the capacity of one
engine, the other could be cut into service and both run
in parallel. It was claimed that this plan had been tried
and found successful, even when running alternators in
parallel, and that no trouble was experienced in the regu-
lation.
The load to be handled was residence, store and street
lighting with a small intermittent motor load on the wa-
ter-works pumps. It would average about 50 kw. at the
-tart, with a peak during the evening. The system ar-
ranged in this manner would allow one engine to be oper-
ated during the regular load, alternating every clay and
using both on the peak. This would also give time to
keep the engines in good running condition.
Another advantage claimed was that, as only one gen-
erator would be used, the first cost would be less, including
a smaller switchboard and less wiring. It was further
proposed that when the load had increased to an aver-
age of SO or 100 kw., a second unit consisting of one
engine and one generator (with an additional producer)
could be installed and operated at about full load. The
combination unit would then be held as a reserve and
used to help out on the peak load, running one or both
engines as the conditions required. This plan would in-
sure the engines' being fully loaded at all times and
would reduce the coal consumption per kilowatt-hour to
the lowest point.
Arguments that may be advanced against this plan
are that the system consists of outside pole lines and there
would be considerable danger from lightning. The gen-
erator and switchboard would of course be protected by
lightning arresters, but there is a possibility that the gen-
erator might be damaged from this source, which would
put the entire plant out of commission. An alternating-
current generator as a rule is not as liable to be damaged,
856
POWER
Vol. 41. No. 25
in the machine itself as a direct-current machine, there
being no commutator; but trouble might develop, either
in the machine itself or in the exciter, which would put
the entire plant out. 1 1 is probable thai no breakdown
service could be provided, as the idea is to take the load
away from the central station at the expiration of the
franchise.
Another proposition was to install two 100-hp. boilers
and one Corliss engine to operate at 125 lb. and 150
r.ji.m.. and direct-connected to the generator. The builder
claimed that this arrangement could lie depended on to
run IS or 24 hr. a day. 7 days a week, and with only a
few minutes' stop once or twice a week for keying up and
other minor adjustments. This would fill the require-
ments of the plant for several years to come or until
money was available for a second unit. It must be re-
membered that these plans were not advocated as being the
best, but to get a plant with the money available at the
time the central-station franchise expired.
The greatest objections to this single-unit steam plant
in addition to generator trouble is that in order to carry
the peak and the increasing average load, it would be
considerably underloaded a greater part of the time, and
the steam consumption would be correspondingly high.
The matter has not yet been settled. Usually, it has
been considered poor policy to depend on one unit for con-
tinuous operation, although the writer knows of several
instances where this was done for a number of years, and
the engine, as a rule, was stopped only half au hour at
noon once a week, running 24 hr. a day and carrying ap-
proximately full load.
J. C. Hawkins.
Hyattsville, Md.
§§
There appear to be two principles that might be used
to improve the action of boiler furnaces in addition to
those already utilized. They have been used in analogous
arts and might lie availed of to make the combustion of
the fuel used with boilers more efficient.
The first is based on the old method of brightening
a fire by means of a poker or iron. It consists in plac-
ing the iron in a dull fire where the combustion is
most prominent and leaving it there. The iron accumu-
lates and stores the heat and not only prevents the fire
from dying out, but conveys the heat to other parts of
the fuel. It also takes up heat that would otherwise
pass off in the gases. When the iron becomes red-hot it
acts like a burning coal, except that it does not burn out
and stop heating.
This principle could lie used in boilers by placing a
number of rods across the furnace so they would come in
contact with the fuel above the grate. They could even
be extended along the path of the furnaces through the
boiler parts, so that the gases would have heat supplied
to them during the entire period. The rods, being con-
ductors, would supply heat to the gases at all points at
about the same temperature as they (the rods) were at,
in the furnace. The rods would deteriorate, but that
would not of itself be an argument against their use.
If the rod was hollow, particularly in the portion
that was in the furnace, it could be used to convey the
draft or air to the furnace where it was needed and with-
out cooling the fire, and at the same time the air would
tend to keep the rod sufficiently cool to prevent melting.
The second principle consists in using materials that
will raise the temperature of the fire and that do not burn
themselves — for instance, chalk, unglazed ware, etc. This
principle is like that used in an incandescent gas burner.
It might lie employed by mixing the material with the fuel
or by installing it in some back part of the furnace so
as to heat the gases or promote combustion in some spe-
cial part of the boiler. In any case, it would serve to in-
crease the efficiency of the fuel used and to stabilize the
operation of the boiler in somewhat the same way that a
flywheel does the action of a reciprocating engine.
These are theoretical suggestions. Cau they be made
of practical use?
A. P. Connor.
Washington, D. C.
'M
Differential draft and air-supply gages are inexpensive
in comparison with the saving they represent. Time
is well spent in their upkeep. Imperfect connections to
furnace or ashpit thwart their purpose.
Water has too variable a capillarity to be employed as
an indicating fluid. Kerosene may be used in an
emergency. The best liquid is a mineral oil of 39 degrees
gravity, Baume scale, at 60 deg. F. and specific gravity
about 0.834. This oil evaporates slowly, is a good lubri-
. cant and will recede to the zero mark. To set the
differential gage both ends should be free to the
atmosphere. The liquid should be poured carefully into
the reservoir end until the zero mark has been reached.
No set of rules can be laid down as to the amount of
draft to be carried, as load, fuel-bed thickness and other
factors affect each case differently. A near approach to
a balance seems to be the aim in many plants. It is
true that a high degree of perfection in combustion can
thus be attained and a high CO, record made, but for
practical operating conditions I prefer at least 0.02 or
0.03 in. of water over the fire. Of course, a pressure
of 0.06 or 0.07 in. or even 1.02 in. under the fire will
do no harm if the firebed is well sealed.
Edward T. Binns.
Philadelphia, Penn.
M.eEta©^nimg Sca.1© fi?©sim OiI=
Operators of oil engines often experience trouble with
the cooling water sealing up the cylinder jackets; in
fact, in some localities the jacket almost fills with scaly
deposits in a few weeks. The method usually employed
is to allow a dilute sulphuric-acid solution to remain
in the jacket for a few hours, thereby loosening the scale.
This is effective, but rather severe on the cylinder walls.
A short time ago the writer met with this trouble and
eliminated it by using graphite mixed with oil and placed
in an ordinary hand oil pump connected to the cylinder
jacket. Tlie i ngineer operating this engine gives the
pump two or three strokes a few ti+nes each day. It
seems that the graphite acts upon the jacket in the
same manner as on boiler tubes.
L. H. Morrison.
Fremont, Neb.
June 22. 1915
P 0 W E R
857
Iirnqrunioes ©f Geime-ml IiMerest
Estimating Piston Speed of Duplex Pump — In a duplex
pump how is the piston speed determined from the length of
stroke and the number of revolutions per minute?
F. P. K.
The term, piston speed, has reference to the average ve-
locity of the water pistons, and when each side makes the
same length of stroke the average piston speed in inches per
minute would be found by multiplying the length of stroke
in inches by two, and by the number of revolutions per min-
ute. This product divided by 12 would be the average piston
speed in feet per minute.
Drilling Small Holes in Glass-
drilling small holes in glass?
-What is a good method of
G. W. K,
Small holes can be drilled in glass by employing a flat
drill lubricated with turpentine. In drilling small holes
through thin glass, care should be taken that the drill does
not break through and thereby shatter the glass. Where
possible, the drilling should be done from both sides. Another
method is to employ a drill made of brass pipe having its end
cut off square and one or more slots in its side for the intro-
duction of flour of corundum.
Stability and lsoehronism ot Governors — What is the dif-
ference between stability and isochronism of steam-engine
governors? G. R.
A governor is said to be stable when it assumes a definite
position for each particular speed and when a change of
speed is necessary for a change of position, while a governor
which is in equilibrium at but one speed is said to be isochro-
nous. Perfect isochronism would be impractical, as the slight-
est increase in speed above the normal would result in cutting
off the steam, accompanied by a sudden decrease of speed,
following which the steam valve would open wide, thus giving
rise to extreme fluctuations.
Water Hammer in Steam Pipes — What is the explanation
of water hammer in spaces containing steam, and particularly
the snapping and cracking noise often heard in steam pipes?
R. W. R.
Water hammer is attributed to the impact of particles or
slugs of water upon each other or against the sides of a pipe
or other containing vessel, due to the formation of vacuous
spaces that result from cooling and condensation of the steam.
Water is comparatively incompressible, and a continuation of
the high velocity of the steam toward such a vacuous space
after condensation has taken place and the movement of
slugs of water toward those spaces at high velocity by the
elastic force of the steam result in violent impacts, similar
to those occurring when inelastic bodies impinge upon each
other at high velocities.
Size of Steam Pipe — Allowing a velocity of 5000 ft. per
min., what diameter of steam pipe would be required to pass
6500 lb. of steam per hour at a gage pressur
sq.in.?
of SO lb.
Referring to the steam tables
volume of dry saturated steam ;
lute, is 4.65 cu.ft. per lb., and a
6500 H- 60
B. E.
, it is found that the specific
t SO lb. gage, or 95 lb. abso-
5 the flow would be
10S.33 lb.
of steam per min., the volume flowing per minute would be
1HS.33 X 4.65 = 503.73 cu.ft.
and the required cross-sectional area of the steam pipe for a
velocity of 5000 ft. per min. would be
503.73 X 144
= 14.5 sq.in.
5000
,-hich corresponds to
4
diameter, and therefore 4%-in. steam pipe would he the near-
est commercial size suitable.
Relative Merits of Belt Dressings — In what particulars
should the relative merits of belt dressings be considered,
and how can they be practically compared?
E. W. C.
The leading merits of belt dressings consist in (1) in-
creasing the coefficient of friction between the belt and the
pulley, enabling transmisison of a given power with a lower
belt tension; (2) increasing the pliability, and (3) prolonging
the life of the belt. The relative friction can be practically
determined by treating each half of the length of a belt with
one of the dressings or by applying the dressing to only one
half for comparison with an untreated half, and, with the belt
in use, observing which half first shows slippage when the
belt is gradually loaded to its transmitting capacity. Or,
after use for some time, the relative coefficients of friction
can be approximately determined by alternately hanging the
belts over the same pulley, and determining which condition
requires the greater load to be suspended from the belt over
one side of the pulley to slip the belt in raising a given weight
suspended from the belt over the other side of the pulley.
Relative pliability is made apparent by observing which
belt forms a smaller loop when folded over on itself, or when
equal lengths of each belt are gathered, and suspended. The
effect of dressing on durability of a belt can only be deter-
mined by test of time and usage.
Volume of Air for III
of air is required for cc
ruing n Pound of Coal — What volume
ibustion of a pound of coal?
The
formula
air required is given approximately by the
Weight of air in pounds = 12C -f 35 (H -
in which C, H and O represent the parts of a pound of carbon,
hydrogen and oxygen in a pound of the coal.
Applying the formula to the analysis of most coals will
show that about 12 lb. of air is required for combustion of a
pound of the fuel, and as one pound of air at 62 deg. F. has
a volume of 13.14 cu.ft., then 12x13.14, or about 158, cu.ft.
of air will be required to burn each pound of the fuel. For
certainty, however, that the carbon will meet with an abund-
ance of oxygen, it becomes necessary to admit an excess of
air, depending on the draft, and the weaker the draft the
more the excess required. Hence, with chimney draft it is
usual to supply about 300 cu.ft. of air per lb. of coal, and
with forced draft about 200 cu.ft. of air per lb. of coal.
Discharge of Water from Hydrant — What quantity of
water would be discharged per minute through a short 2-in.
pipe connected to a Are hydrant in which the pressure is 60
lb. per sq.in.?
M. A.
The rate of discharge would depend upon the roughness
and length of the pipe and the pressure at the entrance of the
pipe. Assuming that the pressure 60 lb. per sq.in. is main-
tained while discharge is taking place, then as 60 lb. per
sq.in. would be equivalent to
60 X 2.3 = 13S ft. head
and as the theoretical velocity in feet per second due to the
head would be given by the formula.
v = l/2gh
in which
v — Velocity in feet per second;
g — 32.16, the acceleration of gravity;
h = 13S;
then.
v = v/64.32 X 13S, or about 94.2 ft. per sec.
If the pipe has a smooth bore and a length 3 to 3*4 times
its diameter, that is, 6 to 7 in. long, and has a smooth, square
entrance end, then the actual velocity of discharge will be
about SI per cent, of the theoretical, and as the cross-sec-
tional area would be
2 X 2 X 0.7S54 = 3.1416 sq.in.
the discharge would be approximately
u. M x 94.2 X 12 X 3.1416 X 60
= 747 gal. per min.
231
It is assumed that the pressure at the entrance of the 2-in.
pipe is ascertained from indication of an accurate pressure
gage during the discharge, as that pressure is not to be con-
fused with the static pressure which exists only when no dis-
charge is taking place.
858
POWER
Vol. 41. No. 25
With a registration of over one thousand, the thirty-eighth
annual convention of the National Electric Light Association
at San Francisco, June 7-11, was an unqualified success. The
eight-story building, "Native Sons of the Golden "West," served
as headquarters for registration and meetings, and the Hotel
St. Francis, adjoining, cared for most of the delegates and
was the center of the social features of the convention, espec-
ially the reception given on Monday night by the president,
H. H. Scott. On the same evening was dedicated the "Temple
of Light." an Ionic colonnade erected around the Dewey monu-
ment in Union Square. This was turned over to the visitors
by John A. Britton on behalf of the local members, and
President Scott accepted it on behalf of the convention.
At the opening session on Tuesday morning, the visitors
were greeted by Mayor Rolph, of San Francisco, and by John
A. Britton, general manager of the Pacific Gas & Electric Co.,
who briefly outlined the progress of the Pacific Coast States,
with special reference to the important part played by elec-
tricity in their development.
Response was made by President Scott, who in the course
of his address pointed out the great decrease in the price
of electric service during the past 15 years, whereas the price
of most commodities had increased. This had been due to
increased efficiency in production and to more efficient light-
ing, the public having derived the benefit.
The remainder of the morning was taken up with the
reports of the secretary and of several committees. T. C.
Martin, as chairman of the Committee on Progress, dealt with
the present conditions of the electrical industry, pointing out a
steady increase in spite of the recent business depression,
although there have been practically no additions to the
number of large central stations during the past year. The
second part of the report (read at the hydro-electric session)
was devoted to hydro-electric and transmission work, and
discussed the pending national legislation on conservation.
It suggested that the law be framed so that the banker
shall know reasonably well to what extent the investor is
protected and to what extent he must accept risk. Opinions
were quoted from a number of men associated with hydro-
electric work, notably Hugh L. Cooper, who stated that within
the past 10 or 12 years hydro-electric plants aggregating over
600,000-hp. capacity had either been through receivership or
had proved bad investments.
FIRST TECHNICAL SESSION
The first technical session was held on Tuesday afternoon,
at which were read the reports of the committees on Meters,
Electrical Apparatus, and the Grounding of Secondaries, as
well as two papers — one on "Application of the Diversity
Factor," by H. P. Gear, and the other on "Features of the
Lighting of the Panama-Pacific Exposition," by W. D'A.
Ryan, illuminating engineer of the Exposition.
In the report on electrical apparatus, attention was called
to the introduction of the phase-advancer in performing the
same functions as the synchronous condenser in connection
with inductive motor loads. While condensers serve primarily
for regulating a complete installation, the phase-advancer
provides an economical means for regulating the power factor
of an individual motor. Among the recommendations of the
committee were the use of electrolytic arresters with rotary-
converters and suitable methods of grounding the converter
frames. Modifications of the rules of certain member com-
panies to conform to those of the majority with regard to
motor connections was urged, as this would greatly simplify
the problems of manufacturers and distributors of standard
commercial motors.
FIRST ACCOUNTING AND COMMERCIAL SESSIONS
Simultaneously with the first technical session were held
the first accounting session and the first commercial session.
The order of business of the former included an address by
the chairman, H. M. Edwards, and reports from the Library
Committee, the Question Box Committee, the Committee on
Uniform System of Accounts, and a paper by L. R. Reynolds
on "Some Opportunities of Public-Utility Accountants."
The commercial section, after listening to an address by
the chairman, Douglas Burnett, heard the reports of the
committees on Foreign Relations, Finance, Publications, the
Education of Salesmen, and the Commercial-Department Term-
inology.
On Wednesday morning the association listened to an
address by President Moore of the Panama-Pacific Exposition,
who reviewed the hydro-electric development on the Pacific
Coast and spoke of the electrical illumination at the Exposi-
tion. He said that about 850 conventions had chosen San
Francisco for their place of meeting this year.
Following President Moore's address were held the first
hydro-electric and second technical sessions, the second com-
mercial session and the second accounting session. Chairman
Wagner called to order the hydro-electric and technical ses-
sions and the report of the Hydro-electric Committee was
read by Mr. Downing, in the absence of the chairman, R.
Bump.
REPORT ON PRIME MOVERS
The report of the Committee on Prime Movers was next
read by Mr. Coldwell, in the absence of Chairman Moulthrop.
The report called attention to the improvements in the design
of surface condensers during the past year and also to the
increased economy obtained by large steam turbines. Two
new stokers of the underfeed type for high capacity were
described, and considerable space was devoted to the subject
of economizers. The steady increase in the rate of evapora-
tion, with a consequent increase in the volume and velocity
of the flue gases and a somewhat higher temperature at the
boiler exit, together with the improvement of condensing
apparatus, producing lower vacuum and lower hotwell tem-
peratures, have created conditions more favorable to the use
of economizers. Under "Gas Power," figures "were quoted to
show that there are vast quantities of fuel-oil in the United
States and in Mexico and that there is much activity in Diesel-
engine work among American manufacturers. The gas-engine
situation however, seems to be little changed from that of
last year; this also applies to the gas producer.
In discussing the report, Henry Hull, of the Puget Sound
Traction, Light & Power Co., of Seattle, stated that it had
been the experience of his company in burning low-grade,
highly volatile lignites, such as are available on the Pacific
Coast, that the best results were obtained by the use of
continuous chain grates of large area installed in furnaces
with dutch ovens. He believed it impera'tive that the coal
be of uniform size to prevent occurrence of holes in the fuel
bed and to secure a uniform fire; also that it is necessary,
in using a chain grate, to employ a free-burning coal, as any
tendency to coke will give trouble from jamming and piling
up at the back of the furnace.
June 82, im;
PO WE R
859
ciatioi\ At, The Exposition
In tlie speaker's opinion, the use of economizers depends
entirely upon the individual conditions. In plants operating
with steam-driven auxiliaries and where leaks in boiler set-
tings are minimized and baffling kept tight, the advisability
of installing economizers appears doubtful. He believed that
if more attention was given to utilizing the heat in the
boiler itself, the results would tend to offset the desirability
Of the economizer.
A written discussion by Professors Rosencranz and Phillips,
of the Oregon Agricultural College, dealt with the control of
combustion when burning oil fuel. The authors pointed out
that the combustion of oil is practically an instantaneous
process, and assuming the ratio of oil to air to be correct
with a uniformity of mixture and the proper combustion space,
maximum efficiency of combustion will result. An instrument
showing the instantaneous rate of flow of the air and oil
to the furnace would go far to solve this problem. The C02
recorder has been a big help in this respect, but it is handi-
capped by the fact that it is from three to ten minutes late
in its indications, which is a disadvantage on variable loads.
It was pointed out that the boiler itself could be made its
own gas or air meter by attaching a differential draft gage,
one end to the combustion space and the other end beyond
the last pass. This would measure the boiler resistance,
which will be different for every rate of flow, and hence be
an indication of the rate of gas flow through the boiler.
Mr. Philip Torchio, in discussing economizers, gave the
results of some observations made in Europe about a year
ago, to the effect that a considerable saving, probably as high
as 8 per cent, in fuel consumption, was possible under certain
conditions by the use of economizers. However, the whole
equipment of the station must be laid out for such use of
economizers. He believed that in this country it would prob-
ably be difficult to apply the economizers without changing
the auxiliaries and drafts of the boilers, which would make
the problem quite expensive. In new stations, however, he
believed that economizers could be used profitably by design-
ing them for use with the stacks of the Epozee type, in which
air is blown into the stack and creates a draft as in the case
of a steam injector. He called attention to the difference
between European and American practice, in that the former
employed motor-driven auxiliaries almost exclusively.
F. H. Varney, of the Pacific Gas & Electric Co., discussed
the use of soda ash in the boilers, his contention being that
if air is kept out of the boilers there is no need for soda asn
to prevent pitting. For this reason his company has adopted
the open type of heaters.
Appended to the Prime Movers' report was a paper by
C. M. Allen, which discussed weirs, current meters, pitot tubes,
venturi meters, floats, waterwheels and meters, the moving-
screen method of measurement, and the salt-solution method.
Briefly, the latter method consists of discharging a known
amount of salt solution into the water before it passes
through the wheel, then analyzing the water as it discharges
from the wheel, and from accurate chemical analysis deter-
mining the total amount of water discharged by the wheel.
Another method was also cited, of injecting color into the
conduit close to the forebay and measuring the time elapsed
until the color appears in the tailrace.
Professor Peaslee, in discussing Mr. Allen's paper, described
a conductivity meter for measuring the flow by the salt-
solution method without chemical analysis.
The next paper was entitled 'Practice in High-Head Hy-
draulic Plants," by J. P. Jollyman. of tin- Pacific ':.is &
Electric Co., who reviewed the present practice along the
Pacific Coast, pointing out that this favors the use of steel
pipes with either riveted or welded joints. Expansion is
usually provided for by long-radius binds, rather than slip
joints, which are employed only where the pressure is not
excessive. For heads up to 700 ft. and specific speeds as low-
as 12, Francis turbines were recommended, and impulse
wheels for heads up to 3000 ft. or over, with specific speeds
as high as 4 for heads up to L'000 ft. He considered the most
desirable speed for wati iwheel-driven generators of 3000 to
15,000 capacity to be about 400 r.p.m.
In discussing Mr. Jollyman's paper, M. T. Crawford referred
to two 10,000-kw. generators in the White River plant of the
Puget Sound Traction, Light & Power Co., which were origin-
ally fitted with the usual fan type of rotor for sucking air
along the shaft and forcing it out through the windings on
the stator. With this equipment the machines carried a rated
load with a normal temperature rise of not over 40 deg. C.
above the incoming air. It was found, however, that on warm
summer days the temperature of the air to the generator
room reached as high as 35 deg. C, and any overloading of
the machines would give a fairly high temperature in the
windings. Accordingly, the generators were inclosed and the
incoming air taken from inclosed spaces above the tailrace
outside the building. A number of spray nozzles are kept
playing in these inclosed spaces, so as to greatly increase the
humidity, and the air goes in at a temperature of about 17
deg. C. The generators can now be operated satisfactorily at
40 per cent, overload, and the temperature is cut down to 40
deg. between the laminations and the incoming air.
"Analysis of Waterwheel-Governor Efforts" was the sub-
ject of a paper by E. D. Searing. This gave a resume of an
interesting series of experiments made in analyzing a governor
problem at one of the hydro-electric plants of the Portland
Railway, Light & Power Co. Steam-engine indicators were
connected to each end of the governor cylinder of the water-
wheel unit, and continuous records of the varying pressures
from each side of the governor piston throughout one cycle
of operation were obtained. An analysis of the effort of
separating friction and unbalance was made, and the rise of
pressure in the wheel casing, high pressures in the governor
cylinder, overspeed devices and wicket gates themselves, were
thoroughly studied.
The next paper was on "Oil-Burning Standby Plants," by
C. H. Delany, of the Pacific Gas & Electric Co. This paper
will be abstracted in a later issue. In discussing Mr. Delany's
paper, E. A. Weymouth mentioned an installation at the plant
of the Inspiration Copper Co., in which the boilers are equipped
with steel casing and most thoroughly insulated. The boiler
efficiency at tin quarters load is higher than at full rating,
and at one-half load it is higher than at three-quarter load.
This is explained h\ the fact thai radiation is much greater
in the case of the ordinary brick setting; and as it is :i
practically constant quantity for all loads, at light load it
will be proportionately greater. The absorption of heal by
the heating surfaces is better at light load, hut with a brick
setting the radiation loss offsets this. With the stei 1 -
however, and a proportionately less radiation Ios:
not hold true to such an extent, with the result that the
efficiency is nearly 2 per cent, better at half load thai
full load
S60
POWE R
Vol. 41, No. 25
The last paper of this session was by D. M. Downing, on
the "Water-Power Development on the Pacific Coast." This
gave a general review of the whole subject and was fully
illustrated.
SECOND COMMERCIAL AND ACCOUNTING SESSIONS
The second commercial session, also held on Wednesday
morning, took up the report of the Committee on Sales
Development in the West, and that of the committee on
Merchandising and Recent Development of Electric Appliances.
At the second accounting session, an interesting paper on
'Workmen's Compensation Insurance" was read by Walter
G. Cowles, vice-president of the Travelers Insurance Co. He
expressed the opinion that the stock-insurance system is the
only one that furnishes reliable means for reducing future
losses to present fixed values. "European practice," he said,
"along compensation lines, can teach us little or nothing,
because the conditions there and here are widely different."
Following this was a paper on "Electric-Vehicle Cost
Accounting," by W. P. Kennedy, and another on "Record of
Property or Construction Expenditures," by T. R. Ferguson.
SECOND HYDRO-ELECTRIC AND THIRD TECHNICAL
SESSIONS
The hydro-electric and technical sessions were continued
on Wednesday afternoon, the order of business including the
report of the Committee on Overhead Line Construction, a
paper on "Electric Line Distribution in the Pacific North-
western States," by J. C. Martin, the reports of the Hydro-
Electric Sub-Committees on "High-Tension Transmission and
Construction," on "High-Tension Apparatus," and on "Main-
Line Electrification of Railroads."
On Thursday morning the fourth and concluding technical
session took up the report of the Committee on Terminology
and that of the Committee on Street Lighting, the latter
prepared by J. W. Lieb, of the New York Edison Co., covering
a digest of the information made available through an investi-
gation of the street illumination which has been conducted
in New York during the past year. M. J. Insull presented the
report of the Committee on Accident Prevention, and Mr.
Torchio that of the Committee on Underground Construction.
The final paper of the session was on "Opportunities of the
Public-Service Company in General Accident Prevention," by
C. B. Scott, of the Chicago Middle-West Utilities Co.
The third accounting session considered the report of the
Committee on Cost Accounting, a paper by O. B. Coldwell
on "Analytical Accounting for Central-Station Purposes," and
another paper by W. E. Freeman, on "Statistical Machines."
Reports of the Rate Research Committee and the Power
Sales Bureau were considered at the fourth commercial ses-
sion, as well as three papers — "The Commercial Application
of Resistance Furnaces," by C. W. Bartlett, "A Stassano
Furnace Installation at Redondo," by W. M. McKnight, and
"Electric Furnace Power Loads," by F. T. Snyder.
On Thursday evening the Public Policy meeting was held,
at which the report of the Public Policy Committee was pre-
sented by W. W. Freeman, and addresses were made by Max
Thelen, of the Railroad Commission of California, and by
John H. Roemer, a former member of the Wisconsin Railroad
Commission.
ENTERTAINMENT FEATURES
Members of the National Electric Lignt Association at-
tended the Exposition in a body on Thursday afternoon, where
a photograph was taken in front of the Tower of Jewels. The
ceremonies Mere held in Festival Hall, and addresses were
made by President Moore of the Exposition, President Scott of
the Association, Samuel Insull, Arthur Arlett and Mayor Rolph;
and greetings were read from Thomas Edison, Alexander
Graham Bell, Elihu Thomson, Frank J. Sprague, Charles P.
Steinmetz, Charles M. BruL-h, and J. J. Carthy. President
Moore presented President Scott with a bronze medal com-
memorative of the convention.
The entertainment features also included a musicale and
tea for the ladies on Wednesday afternoon, an automobile
trip Thursday morning and luncheon at the Cliff House, after
which they joined the men at the Exposition in the afternoon.
Friday was spent on an all-day sightseeing trip to Mount
Tamalpais and the Muir Woods. Special credit is due to F. H.
Varney, chairman of the local entertainment committee, for
unusual thoughtfulness in providing for the comfort and
convenience of the guests.
E. W. Lloyd, general contract agent of the Commonwealth
Edison Co. of Chicago, was elected president of the association
for the coming year.
m
Hew Jj<BTB<esy M. A. S. ID.
<G©irweE&fts©mi
While it was generally known that the Trenton convention
of the New Jersey N. A. S. E. would consider important asso-
ciation affairs, no announcement had been made that the ex-
hibit was to be one of the best-arranged and attended dis-
plays of engineering supplies ever connected with a state
convention of the association. The exhibit, held in Masonic
Hall, was opened to the public on Thursday, June 3, by Mayor
Frederick W. Donnelly, with an address of welcome. A fea-
ture of the opening evening was an automobile tour of the
Xew Jeksey X. A. S. E. Convention Exhibit Hall
June 22, 1915
P 0 W E E
861
city "engineered" by the Mayor and Frank V. Tuthill, of the
McLeod & Henry Co., and enjoyed by a number of engineers
and supplymen.
The business sessions were held June 5 and 6 in the Tren-
ton House, with Charles Sumner, president of the association,
in the chair. About a hundred delegates attended. National
Vice-President Walter Damon, of Springfield, Mass., and James
Taylor, secretary-treasurer of the Life and Accident Depart-
ment of the association, addressed the delegates during the
Saturday session.
The Educational Committee reported that depressed busi-
ness conditions had caused a slight lull in the educational
activity of the various local associations; this was not serious,
however, as the state committee had made special efforts to
keep the smaller and most-in-need-of-help associations inter-
ested, with the result that their educational work on the whole
was more commendable than that of the larger associations.
The committee expressed the belief that there was no more
thorough and inexpensive way of creating educational interest
than by question-and-answer contests held by each associa-
tion. Many associations have received valuable assistance
from a pamphlet written by the instructor for Newark No. 3
Association. These "Examination Questions" are to be ob-
tained by addressing No. 3 at 103 Market St., Newark, N. J.
The Legislation Committee handed in a short report at the
Sunday session. A. L. Case, chairman of the board of exam-
iners of the State Engine and Boiler Operators' Bureau, point-
ed out some of the defects in the present license law and read
passages from a proposed bill that was vetoed by the gov-
ernor. The law as it now stands reads that "the provisions
of this act shall not be construed to include or apply to men
holding marine licenses or to men in plants under the juris-
diction of the United States Government, or to locomotive
engineers." Many of these engineers "were refused licenses
because the attorney-general handed down an opinion that
they could not be lawfully given to them. The law needed
amending when an engineer holding a license to run a dinky
tugboat could operate the largest plant in the state and be
immune from any action the license bureau might take. The
vetoed bill also provided for a well-deserved increase in the
salaries of examiners, from $1200 to $2000 a year. The con-
vention adopted a resolution introduced by Newark No. 3
■which embodied the amendments needed in the present law
and stated that the governor's veto of the bill was the result
of snap judgment. This resolution was ordered printed and
circulated.
The next convention of the New Jersey State Association
will be held in Paterson, N. J
Both Joseph Carney and William Reynolds, members of
the National Board of Directors, refuted the rumor that the
"National Engineer" was subsidized by central-station inter-
ests. A resolution was passed and ordered circulated em-
bodying their denials.
Saturday a smoker and cabaret were given by the supply-
men under the direction of Frank Martin, of Jenkins Bros.,
at which, among others, appeared the well-known but always
entertaining trio — Jack Armour. Billy Murray and Herbert
Self. The new officers elected are: President, Dennis Bartley,
of Jersey City; vice-president, Thomas Brown, of Newark;
secretary, James S. Heath, reelected; treasurer, William
Krause, of Passaic. During the convention the ladies sold
cigars, candy and tags and otherwise added to the pension
fund for indigent engineers. Mrs. McCoy, state deputy for the
ladies' auxiliary, gave an interesting report of the doings of
the state and national bodies.
A list of the exhibitors follows:
BJsitlioir&giS BDasfornctl MesittSiiagl
Albany Lubricating Co.
Cherry Chemical Co.
Corbett, E. A.
Crew, Levick & Co.
Crook & Son, A II
Dearborn Chemical Co.
Dick, R. & J.
De Laval Steam Turbine Co.
Engineering Supply Co.
Fisher & Norris.
France Packing Cc.
Garlock Packing Co.
Greene, Tweed & Co.
Home Rubber Co.
Homestead Valve Co.
Industrial Requirements Co.
Jenkins Bros.
Johns-Manville Co.. H. W.
Keystone Lubricating Co.
Lunkenheimer Co.
McArdle & Co.
McLeod & Henry Co.
Morehead Manufacturing Co.
"National Engineer "
Ohio Blower Co.
Otis Elevator Co.
Peerless Rubber Manufactur-
ing Co.
Philadelphia Grease Co.
"Power."
Quaker City Rubber Co.
Reeves-Cubberley Engine Co.
Clement Restein Co.
Richardson Scale Co.
Robinson Co., W. C.
Roto Co.. The
Roebling's Sons Co., John A.
Squires Co., C E.
Stahl, Harry E.
Standard Regulator Co.
Steam Appliance Co.
Underwood & Co., H. B.
Webb & Sons Co., Elisha.
Zurn Oil Co.
Following the schedule of fittings and flanges published
on page 782, June 8, 1915, the address of the National Associa-
tion of Master Steam and Hot Water Fitters should have been
given as 260 West Broadway, New York City.
<in June 1, 2 and 3, the seventh annual convention of the
National District Heating Association was held at the Sher-
man Hotel, Chicago. The meeting was a great success. The
papers and committee reports presented were of a high
quality and indicated a vast amount of work in their prep-
aration by practical men engaged in the heating business.
The material presented was received with enthusiasm and
discussed at length. The association has made wonderful
progress since its inception six years ago. and a continuation
of the present interest and enthusiasm will insure results of
inestimable value to the field of district heating.
On Tuesday morning President H. R. Wetherell called the
first session to order. Harry Miller, prosecuting attorney, in
behalf of the mayor, welcomed the visitors to the city. The
response was made by D. S. Boyden. first vice-president of
the association. In his presidential address Mr. Wetherell
believed the day had come when steam heating should not
be regarded as a byproduct of the electrical end of the plant.
It was up to the association to put heating on a paying
basis. The public-service commissions of the various states
were already insisting that the heating be made independent
of the electrical plant so that the low rate formerly made in
connection with lighting would be eliminated. By putting
customers on a meter basis the consumption of steam would
be greatly reduced over the old flat rate and the cost would
be lowered to a reasonable figure. It was important to give
strict attention to service and in every way possible satisfy
the customer.
Secretary Gaskill reported the association in better finan-
cial condition than ever before and an increase of 44 members,
which was 14.66 per cent, of the membership in 1914. He
advised the election of honorary members and recommended
that a suitable badge be presented to the retiring president.
At the end of the session A. P. Biggs, chairman, presented
the report of the station record committee. This dealt prin-
cipally with franchises. Copies of franchises under which 25
different companies were operating had been obtained and
the contents had been spread on a large data sheet, which
was available at the convention. A collection and comparison
of such data, it was thought, would eventually result in a
standard franchise. A table on the steam consumption of
various classes of building and the cost of trenching was in
course of preparation and would be appended to the report
before it appeared in the "Proceedings."
At the opening of the afternoon session J. F. Gilchrist,
vice-president of the Commonwealth Edison Co., of Chicago,
gave an interesting address on steam heating and the advan-
tages of concentration in the generation of electricity and
steam. As heat was one of the requirements of the race, it
was evident that the heating business was founded on a solid
foundation. It was one of the fundamental things human
beings required, and in this respect was a little ahead of its
big brother, the lighting and power business. In establishing
central heating in Chicago, there had been no special fore-
sight. The company had been forced to it. When they at-
tempted to displace the isolated plant, it became evident that
they must know something about the heating business and be
in a position to furnish heat. The speaker explained how the
Illinois Maintenance Co. had been founded in 1S99 and how it
had been built up to its present proportions. No comprehen-
sive system had been laid out. It was arranged so that the
electric-light contract for a building included the right to
operate the plant in the basement to furnish steam for heating
and to connect the plant with the piping of the adjoining
building. Eventually, the piping was carried across alleys
and in some cases streets, so that at the present time there
are several plants taking care of a number of buildings. Mr.
Gilchrist touched upon the importance of metering the steam,
so that it would be to the interest of both the seller and user
to minimize the consumption.
Although the possibilities of concentration in the heating
business were not so great as in the generation of electric
current, the following advantages were enumerated: The re-
duction of smoke, the possibility of obtaining high-grade
labor from which higher economy might be expected, a de-
crease in the fire hazard and a reduction in the expenditure for
handling fuel and ash.
In the United States 517.453,000 tons of coal was consumed
per year. Of this amount central stations used 17,375,000
tons, street- and electric-railway plants, 10,078,000 tons; steam
railways, 100,000,000 tons; and all other uses, 390,000,000 tons.
Electric light and power and street railways only consumed
5 per cent, of the fuel. If the hydro-electric output was
reduced to a steam basis this would account for 17,-
S62
POWER
Vol. 41, No. 25
000,000 tons, so that the entire electrical output would only
require 44,000,000 tons per year, or less than 10 per cent, of
the total. The speaker expressed a desire to see a comparison
of the work done in the different fields. It was certain that
outside of the electric light and power business the coal is
burned much less efficiently. Coal for domestic use was esti-
mated at 50 to 100 million tons, leaving the remainder for
heating and industrial purposes. By concentration much of
this coal could be saved or at least be held to the same figure
notwithstanding the increase of population. It was the
speaker's opinion that there will in the next few years be a
great development in the heating business. The importance
of this service in connection with light and power will become
greater in the years to come. The distribution of heat was
a natural monopoly, and it should be permitted to act as such.
It should be made independent of lighting and power and
should come under the same regulating bodies as the central-
station companies.
REPORT OF PUBLIC-POLICY COMMITTEE
Recognizing the desirability of all utilities following some
form of general policy, the association has a standing com-
mittee on this subject. In the report presented the following
items were briefly considered: Education of the public as to
cost and advantages of heating service, extension, appraisal,
rates, municipal ownership, legislation and franchises. The
comments were general, leaving it to future years and com-
mittees to elaborate and definitely design the policies that
should be pursued as conditions change and future develop-
ments require.
UNDERGROUND CONSTRUCTION
At the Wednesday morning session H. A. Woodworth pre-
sented the report of the underground construction committee,
which was prepared to give the society the benefit of the best
practice that the present day affords in the selection of ma-
terials and the installation and operation of district heating
mains. Letters had been written to various companies affili-
ated with the association asking for particular data which
they possessed. The replies showed a wide variation in the
methods used throughout the country, and a study of the data
indicated that these variations were not due to the geograph-
ical location or climatic conditions. It was clear that one of
the greatest needs was a closer attention to standardization.
In the report the various items relating to the design, con-
struction and operation of mains were discussed briefly. Most
of the data had been drawn from the letters, but other data
had been received from outside sources. Items requiring re-
search work, such as the design of high-pressure steam
feeders and tests on automatic valves as they affect line
capacity, were turned over to authoritative persons to insure
accuracy in the results. In an appendix to the paper, descrip-
tions were given of the underground insulations and conduits
as they are placed upon the market by the various engineer-
ing and manufacturing companies.
BLEEDER TURBINES
Following an extended discussion on Mr. Woodworth's
paper, F. W. Laas read a short paper on operating experi-
ences with bleeder-type turbines. As a preliminary the
author related an experience he had had with a 1500-kw. tur-
bine of this type, also an experience with a cross-compound
condensing engine supplying steam from the receiver for heat-
ing and eventually from the exhaust of the low-pressure cyl-
inder against a maximum pressure of 25 lb. Mr. Laas enum-
erated the features a successful bleeder turbine should
possess, some of the points to be watched in its operation and
by means of data from specific cases explained the operating
advantages of this type of turbine.
EDUCATIONAL COMMITTEE REPORT
At the afternoon session Wednesday, D. S. Boyden summar-
ized the report of the educational committee. The work had
been divided among the various members of the committee as
follows: The establishment of a standard for transmission
losses from buildings of all constructions, Reginald Pelham
Bolton; the establishment of standard methods of proportion-
ing direct radiation and standard sizes of steam and return
mains, James A. Donnelly; the establishment of a standard
coefficient for heat losses affected by wind movement, H. W.
Whitten and R. C. March; the establishment of standard
heating elements for cooking apparatus, with special refer-
ence to low-pressure steam, D. S. Boyden.
Mr. Bolton's contribution to the report brought out the
wide variation in the hitherto accepted bases of computation.
The various transmission losses through building materials
were presented in tabulated form, with several suggestions
for further observation, which may help to determine these
losses definitely.
Mr. Donnelly's report was devoted mainly to the data re-
quired in estimating the heat requirements for buildings. It
opened with tables of heat losses through building materials,
including the losses through various thicknesses of concrete.
These were followed by rules for estimating the amount of
air required for ventilation. Under transmission from radi-
ating surfaces a useful table was incorporated giving the
relative surface in pipe coils and wall radiators. Another
table showed the comparative transmission from a standard
direct radiator at various steam temperatures. This was
followed by a table giving the proportionate amount of ra-
diation required to heat a room to 70 deg. F. from various
outside temperatures, with steam in the radiator at 210 deg.
F. A feature of many of the tables was that proportional
requirements were given for conditions varying from the
usual standard of 0 deg. outside and 70 deg. inside. Consid-
erable space was devoted to the operation of gravity hot-
water heating systems, vacuum-steam heating systems,
forced hot-water heating systems and vacuum-vapor heating
plants. In the section devoted to standard sizes of steam
mains, a table of steam-pipe sizes based on the Unwin formula
was included. Another table gave the comparative carrying
capacity of pipes, so that after one size is figured for a certain
condition, capacities of all other sizes may be readily ob-
tained. At the conclusion of the report data were given on
standard sizes of radiator connections and return mains, with
a table showing the standard rating for steam mains as well
as the standard for wet returns and for various percentages
of steam carried in dry returns, figured for a drop in pressure
of 1 oz. to 100 ft. of straight pipe.
A close study of the records of the Public Service Co. of
northern Illinois for the past two years, in connection with
other data referred to in last year's report, enabled the mem-
bers of the committee having the work of determining the
effect of wind on heating to obtain data from a large group
of buildings of varied construction. The constant given last
year was modified and now may be used safely, allowing for
certain factors which may affect isolated cases.
The report by D. S. Boyden on standard heating elements
for low-pressure cooking apparatus was one of progress only.
Much remains to be done in this line. The report indicated,
however, that apparatus in the kitchen and elsewhere that
had formerly operated at pressures of 40 to 60 lb. will do the
work satisfactorily on pressures as low as 3 lb. provided the
heating elements are properly designed.
ELECTION OF OFFICERS
The commercial end of the heating business was discussed
in a paper by C. F. Oehlman, and immediately after its pre-
sentation the election of officers took place, with the following
results: D. S. Boyden, president; B. T. Gifford, first vice-presi-
dent; George W. Martin, second vice-president; W. S. Monroe,
third vice-president; D. L. Gaskill, secretary and treasurer;
Thomas Donahue and C. F. Oehlman, members of the executive
committee.
HOT-WATER HEATING
At the fifth session, Thursday morning, W. D. Carlton read
his paper on "The Hot-Water Heating System at the Grand
Central Terminal" in New York City. The paper was brief,
giving in outline the arrangement and general construction,
some of the operating features and capacities and the method
of computing rates for the service.
REPORT OF STATION-OPERATING COMMITTEE
The report of the station-operating committee was then
read by Byron T. Gifford, chairman. It included results of a
boiler test conducted along lines suggested by last year's
committee; statistics on operating costs, with tabulated re-
sults from a number of typical plants; the accounting of oper-
erating costs; general information regarding coal, with a
table giving the designation, origin and analysis of a great
variety of fuel; meters and their uses, including a description
of the new Republic flow meter; and miscellaneous points of
interest, such as the reason advanced by the New York Steam
Co. for softening water that originally contained only 3%
grains of total solids per gallon.
EXHAUST VS. LIVE STEAM
At the last session of the convention, on Thursday after-
noon, C. C. Wilcox read a paper comparing the u:e of exhaust
and of live steam for heating. Tests were conducted on the
heating systems of Peoria and Pckin, 111. From a study of
the tests, the following conclusions were derived: The heat
consumption for the heating system under similar weather
conditions was found to be the same for either live- or ex-
haust-steam operation; the rate of steam *eent to the heating
system is increased as the heat content of the steam is dimin-
ished; the carrying of an electric load in addition to the
heating load cannot be accomplished without an increase in
fuel; the main condensation with live steam is less than with
exhauct steam; the pressure drop between the station and
the end of line is more with exhaust than with live steam.
June 22, 1915
P 0 W E R
863
which may be accounted for by the increased amount of steam
delivered to the system: pulsations in pressure caused by
the engine exhaust are not propagated very far from the
source. A paper by George W. Martin on the same subject
was read in abstract as a part of the discussion on the paper
by Mr. Wilcox. Mr Martin stated that it seemed to be the
opinion of many engineers that in heating a building with
exhaust or live steam a less quantity of the former was re-
quired. A number of instances were cited to show that this
was not the case, provided the same temperatures were
maintained in the rooms and equal attention given to obtain-
ing economical results from the boilers. Investigations in
several buildings had disclosed the fact that the bypass for
admission of live steam into the heating system had been too
small, so that enough steam could not pass through to the
system. It gave the impression that the boilers were not
large enough to supply the demand. By enlarging the bypass
the difficulties were overcome, and the live steam gave as
satisfactory service as the exhaust from the engines.
This concluded the papers, some of which will be abstract-
ed more fully in these columns at a later date. Before ad-
journment the convention discussed the advisability of pub-
lishing a quarterly bulletin devoted to association affairs.
A unanimous vote gave the board of directors power to act if
the proposition was found feasible.
ENTERTAINMENT
Special entertainment for the ladies was provided in ".he
way of a musical and card party, shopping excursions, auto-
mobile sightseeing rides, and a lake excursion on the United
States training ship "Isle de la Luzon." On Tuesday evening
a theater party was attended by all, and on Wednesday even-
ing the banquet, followed by professional entertainment and
dancing, was a great success. Fully 160 sat at table and all
spent a most enjoyable evening.
EXHIBITS
The exhibits were more numerous than usual and pre-
sented an interesting variety of meters, pipe coverings,
valves, steam traps and other equipment used in district
heating. Following is a list of the firms represented: Ameri-
can District Steam Co., American Radiator Co., Armstrong
Cork Co., V. D. Anderson Co., Boylston Steam Specialty Co.,
Cannelton Sewer Pipe Co., Central Station Steam Co., Con-
solidated Engineering Co., G. M. Davis Regulator Co., Detroit
Lubricator Co., G. T. Hornung, Jenkins Bros., H. W. Johns-
Manville Co., Michigan Pipe Co., National Air Cell Covering
Co., Republic Flow Meters Co., E. D. Tyler, Westirghouse
Electric & Manufacturing Co. and A. Wickoff & Sons Co.
Woircestteir Fol^edhsanc C@J©=
Fifty years of engineering instruction at the Worcester
Polytechnic Institute was fittingly celebrated on June !> and 9
by exercises preceding the annual commencement, this ar-
rangement affording an opportunity for both undergraduates
and alumni to attend and listen to the many prominent engi-
neers and educators who participated.
Starting with a reception by President and Mrs. Hollis
at the Bancroft on Tuesday evening, the principal exercises
were held on Wednesday morning in Mechanics Hall, the
speakers, besides President Hollis, including Governor Walsh
of Massachusetts; Doctor Brashear, president of the American
Society of Mechanical Engineers; President Lowell of Harvard;
and Booker T. Washington, the well-known negro educator.
On the platform with the speakers was a large number of
delegates from engineering societies and colleges.
President Hollis, in his opening address, sounded a warning
against carrying efficiency methods to extremes, claiming
that "anyone can understand the application of good sense,
good will and system in the mills and factories, but no Ameri-
can can approve any plan that lessens the responsibility of
the individual by turning him into a machine."
Doctor Lowell was of the opinion that control over the
forces of nature, as gradually worked out by the engineer,
had more to do with human prgress, and especially the aboli-
tion of slavery, than any change in morals. He pointed out
how, in the days of the Roman Empire, the ships were rowed
by slaves, but as soon as other and better methods of pro-
pulsion were worked out through control of nature's forces,
the necessity for these slaves ceased. He cautioned, however,
against the misuse of engineering knowledge in lines that
would be detrimental to humanity.
The Governor extended to the Institute the congratulations
of the State, and was followed by Doctor Brashear, who in
his characteristic humorous strain touched upon the human
element in engineering work, emphasizing that education
should not be for the good of the individual alone, but more
particularly to enable one to better aid mankind. Doctor
Washington told of the work being done in the negro trade
schools with which he is connected in the South.
On Wednesday afternoon the local and visiting members
of the American Society of Mechanical Engineers listened to
a paper by Professor Alden on the history of the Washburn
shops. These shops, in which the students of the Institute
receive their practical training, consist of forge, foundry and
machine shops and are carried along on a strictly commercial
basis, the student working as an apprentice along with a
paid journeyman.
In the evening a banquet was held at the Hotel Bancroft,
about 600 attending. The speakers included Senator Weeks
of Massachusetts; Major-General Wood; Howard Elliott, presi-
dent of the New York, New Haven & Hartford R.R. ; Arthur
D. Little, of Boston; Mayor Wright of Worcester; and Francis
W. Treadway, ex-lieutenant-governor of Ohio.
<ST~W<a>w<eT SMscaflssaosra &k a
The outstanding feature of the conference of Western
governors held in Seattle during May was the discussion on
legislation for the use of water power. Those who took part
in the conference were the governors of Oregon, Washington.
Idaho, .Montana, Nevada. Arizona. Utah and Colorado. Gov-
ernor Carlson, of Colorado, read a paper entitled "Unlocking
the West."
That satisfactory results will follow the regulation of
water-power sites by the Federal Government rather than
the states was questioned by Governor Carlson. He did not
favor the adoption of legislation by Congress along the lines
of the Ferris bill, which provides that permits for the us.-
of water power situated on government land shall be granted
for fifty years, carrying the right of the Government to take
over the property at the end of that time at a reasonable price
for its physical value.
"We can't trust the state to manage water-power re-
sources as well as we can trust the Government," Gov-
ernor Boyle said in reply. "States are clamoring now to give
away their resources, and while they may pretend to have the
door closed, nevertheless their natural resources will be
packed out of the windows."
"It is an outrage and shame the way our reasources in
Oregon have been managed," said Governor West. "The
plan of Secretary Lane for the leasing of water-power sites
is a just one. The bill he proposes does not take away any
of the sovereign rights of the states. They cannot be taken
away by an act of Congress. What is a granted privilege to-
day becomes a vested right tomorrow, and that is why the
leasing system is best."
The argument was advanced that the royalty paid to the
Government would be borne by the consumers of power and
light, as it would be counted by the managers of the hydro-
electric projects as a proper item of operating cost.
Governor Carlson outlined his position clearly and force
fully in his paper:
So long as the Department of the Interior revoked power
permits only for misuse and nonuse. millions of dollars were
put into power plants upon the public domain. The mo-
ment this principle was departed from, all development
ceased. It is now proposed to remedy the situation
by giving permits that will run for fifty years and
carrying the right of the Government or the state or munic-
ipality to take over the property at the end of the term upon
a basis of physical valuation. The plan also proposes to
regulate the price of power and to divide the taxes assessed
against the property between the Government and the state.
For the sake of argument only, conceding the right of the
Government to pass such a law. and supposing that it will
pass. I do not believe any great development will follow.
It is entirely unlikely that investors will put money into proj-
ects where no title passes; where the property might be sub-
ject to the onerous rules and regulations which thereafter
might be promulgated; where there is possibility of conflict
between the laws of the state and the rules of the Depart-
ment of the Interior.
Investors are not likely to take kindly to a plan that
would keep a property upon their hands if the venture be a
losing one. or that might be taken from them if it proved a
profitable one. The power of eminent domain inherent in
every sovereign state has been used again and again when it
has "been found necessary to beneficially use the waters of a
stream. Private property has always been subject to the
exercise of this power by the state or delegated agents, and
the only theory that would prevent its exercise by the states
upon government lands is that such are not held by the Gov-
ernment in a private proprietary capacity, but as a su-
perior sovereign power within a sovereign state. There is
not a line in the Federal Constitution giving the Government
a right to set up an independent sovereignty within the
borders of a state, and I believe the time is not far distant
when Congress will pass legislation declaring the inherent
rights of Western states. Our greatest obstacle at the present
864
P 0 \Y E B
Vol. 41, No. 25
time is to bring- the East to our view. This is not as diffi-
cult as it was ten years ago. The multiplication of cases
where millions of dollars of capital were planned to be ex-
pended in 'Western states for the development of its low-
grade ores, of lighting plants, power plants, interurban
lines, irrigation projects, etc., that have been diverted to
Mexico. Bolivia and other foreign countries will strike home
sooner or later to the Eastern manufacturer, and he will
undergo the inevitable disillusionment of the enchanting-
theories of the ultra-conservationist.
"I think the policy of the Government holding title and
leasing power sites to individuals, giving them only tempo-
rary control, is opposed to the best interests of the states,"
said former Governor Hawley, and he recited several cases
that have gone to the highest courts of the land, upholding
the sovereign power of the states in the management of their
resources.
The conference, however, before its adjournment did not
come to a definite agreement on legislation for the use of
water power, as it was the sentiment to postpone action until
the water-power conference to be held in Portland, Ore., Sept.
21-23, which the governors will attend. This question is also
expected to be one of the leading features of the national
conference of governors of the country to be held the last
week in August, at Boston, Mass.
IFlaitlIir&g| ©f Diesel EEagpiraes
In the course of a lecture before the Junior Institution of
Engineers, W. A. Tookey, the well-known English authority
on internal-combustion engines, referred to the high rates
asked for insurance against breakdowns of Diesel engines
and to the occurrences reported from time to time in the
technical press, in which broken crankshafts, seized pistons
and similarly serious accidents are mentioned. These oc-
currences, he thought, proceeded mainly from the overstress-
ing of cranks and the excessive heating of pistons, due to a
prevalent tendency to over-rate the permissible output from
given cylinder dimensions. He was inclined to lay the blame,
not upon the technical men responsible for the details of
construction, but upon those who are intrusted with the nego-
tiations with prospective purchasers and who are particularly
interested in claiming as small a ratio as possible between
horsepower developed and initial cost. Cases had occurred in
which lack of appreciation of this point had led to the engines
working overloaded, or where it was found necessary to re-
duce the load originally contemplated, in order to avoid risk
of breakdowns. Thus it bad happened in a number of cases
that the Diesel engine had not enjoyed the reputation that its
high thermal efficiency and general reliability so amply mer-
ited when properly selected, erected and maintained.
Proceeding further to discuss this phase of the subject,
the speaker pointed out that while the limit of power in an
internal-combustion engine cylinder is definitely established
and recognized, the rating of electrical machinery is purely
arbitrary and apparently, therefore, much more elastic. Ex-
perience had dictated that a "rated" output about 10 per cent,
below the permissible maximum, or overload rating of Diesel
engines, is satisfactory and convenient. In smaller cylinders
this could be based on a higher mean pressure than is advis-
able with cylinders of larger sizes.
He concluded with references to the manipulation of de-
tails in starting, running and stopping, and many valuable
practical hints were given in this connection, both for single-
and multi-cylindei engines. Particular emphasis was laid
upon the paramount importance of scrupulous cleanliness ami
conscientious management, a matter which depends quite as
much upon the personal attribute of the attendant as upon
his technical ability.
CLAUDE H. HUNTINGTON
Claude H. Huntington .lied May 21 after a brief illness.
At the time f his death he was president of St. Louis
Association No. 2, National Association of Stationary Engi-
neers.
HARRY H. WHEELER
Harry H. Wheeler, of St. I. .mis, Mo., died suddenly on
June 2, from injuries received in an automobile accident. II"
was a past-president of St. Louis Association, No. 2, X. A. S.
E., and was a brother of William Wheeler, of New York, a
Past-National President of the organization. About twenty-
five years ago lie left New York City to make his home in
St Louis. He is survived by a widow and three daughters.
JOHN P. FARLEY
John F. Farley, who died June 6 in Brooklyn, had foi
many years been employed as an engineer in the Department
of Water Supply. Gas and Electricity of the City of New
York, and for the last four years had been with the De-
partment of Sewers. He was a member of the N. A. S. E. and
the International Union of Steam Engineers.
WILLIAM NAYLOR
William Naylor died June 13 in Chicago at the age of 83.
He was born in Lancashire, England, and seven years later
began work operating hand machines in a calico-printing mill.
He was apprenticed as machinist's assistant in the railroad
shops at Bradford at the age of 9 and worked continuously
until he retired last year. After serving several years as a
locomotive driver on roads running between Yorkshire and
Liverpool, he left England in the fall of 1858, and reached
America by way of New Orleans, after a voyage of seven
weeks on a combination steam and sailing vessel. He came
by boat up the Mississippi and Ohio Rivers, and was employed
as a sawmill operator and flour-mill engineer in Wabash
County, Illinois. At the close of the Civil War he moved to
William Xaylor
Missouri, and in 1S68 to Chicago. He worked as engineer in
flouring mills until 1871, when he engaged with Field, Leiter
& Co., now Marshall Field & Co. In those days the engineer
and one fireman were able to easily take care of all the
machinery of the corporation which today has 20 or 30 build-
ings and 250 men in the various engine departments. Mr.
Naylor's long and faithful service was fully appreciated by
the Marshall Field Co., which retired him last year on a
handsome pension. He was a member of the National Associa-
tion of Stationary Engineers since 1S90, treasurer of the
Robert Fulton Association continuously for 22 years, and was
also a member of the Chicago Steam Engineers' Club. He
was married to Ann Haigh before he left England and was
the father of Charles William Naylor, Past National President,
X. A. S K It was said that he was a friend of almost every
operating steam engineer in and about the city of Chicago.
CHARLES E. CHINNOCK
Charles E3. Chinnock, a manufacturer of telegraph instru-
ments and one of the pioneers of the electric-light and tele-
phone industries, died June 11 in Brooklyn, X. Y„ in his
seventieth year. When the telephone and electric light were
still in their infancy he became associated with Thomas A
Edison, was later the superintendent of the first central station
of the New York Edison Co., and as the vice-president of the
Edison United Manufacturing Co., the parent Edison company,
he was largely responsible for the founding of the Edison
Electric Illuminating Co. of Brooklyn. The Edison United
Manufacturing Co. was merged with the Thomson-Houston
Co., which afterward became part of the General Electric Co.
Mr. Chinnock was also chief electrician of the Metropolitan
June 22, 1915
POWER
865
Telephone Co., now the New York Telephone Co., and he
patented many electrical inventions, among them an auto-
matic trano: -lit', ;r, for t aching telegraphy that was adopted
by the U. S. Governm:nt. Another of his inventions used
by all tin t Ieph ne and telegraph companies is a method of
suspending a".i 1 cables.
AUSTIN I. RD BOWMAN
Austin Lord Bowman, one 01 me foremost bridge build-
ers and engineers in this country, died June 3, at his home
in New York City He was born in Manchester, N. H., in
1861. and studied engineering at Yale, graduating in 1883. He
engaged in engineering work continuously until the time of
his death, specializing in design and heavy construction in
both railroad and bridge work. Of his more important work.
the construction of the Kings County Elevated Railroad in
Brooklyn, his service as engineer in charge of construction
for the American Bridge & Iron Co., and his reconstruction of
the bridges on the Central Railroad of New Jersey are es-
pecially worthy of mention. He was made a member of the
American Society of Mechanical Engineers in 1899 and was
also a member of a number of other engineering societies.
In 1907 he entered the service of New York City as con-
sulting engineer of the Bridge Department, and in a few
years was made chief engineer of the department, the po-
sition he held at his death. Commissioner Kracke, of the
Bridge Department, and the chiefs of thirty departments
under him, drew up suitable resolutions expressing their
condolence, which will be embossed on parchment and pre-
sented to the family of their associate.
FE1SOHALS
S. H. Viall, assistant chief of the Chicago smoke depart-
ment, has severed his connections with the city and is open
for engagement.
Robert H. Kuss has severed his connections as sales engi-
neer with the Edge Moor Iron Co. and will devote his time
to advisory engineering.
J. A. Carson, better known as "Jack" Carson, formerly
with the Durabla Manufacturing Co., is now connected with
the Home Rubber Co., Trenton, N. J.
Hill & Ferguson, consulting engineers, 100 William St.,
New York City, have opened a laboratory for analyzing water
and chemicals used in water treatment, as well as coal,
oils and boiler compounds, and for testing the calorific value of
coal.
S. F. Jeter has been appointed chief engineer of the
Hartford Steam Boiler Inspection and Insurance Co. This
is a recently created office, the holder to have general charge
of the mechanical work for the company. Mr. Jeter for the
past four years has held the position of supervising inspector
in charge of the inspection service of the company.
The Connecticut State Association of the N. A. S. E. will
hold its annual convention at Hartford, on Friday and Sat-
urday, June 25 and 26. The Engineers' Committee, assisted
by the officers of the Supply Men's Association, has about
completed the final arrangements, and a successful meeting
is looked forward to.
The American Society of Refrigerating F^ngineers will hold
its fourth Western meeting at San Francisco on Sept. 23 and
24. A special train, leaving Chicago Sept. 15 and arriving
in San Francisco Sept 21, has been arranged for the members,
their families, and friends. Those attending the meeting
will have the opportunity of attending the International
Engineering Congress, which takes place from Sept. 20 to 25.
Details of the trip may be obtained from the secretary of
the association, W. H. Ross, 154 Nassau St., New York City.
The American Railway Master Mechanics' Association held
its 4Sth annual convention, June 9-11, at Atlantic City, N. J.
During the sessions committee reports were presented relat-
ing to locomotive stokers, smoke prevention, locomotive
boilers, fuel economy and boiler washing. The Committee on
Locomotive Stokers reported that the device was withstand-
ing the test of continuous service with remarkable durability.
Nothing novel has been presented during the past year, but a
great deal of good work has been done in redesigning and
improving detailed parts to better withstand the service.
Data gathered from the scatter-type stokers In more exten-
sive use show that the cost per 100 miles ranges from 43 to
68c, and the miles run per failure from 1000 to 5000. The
committee felt unable to point to any rule in terms of "weight
pf engine or train load, or to general conditions where the
stoker will always be applicable or necessary. This is owing
to the wide range in physical and operating conditions and
in the character and prlci of fuel. According to the Com-
mittee on Smoke Prevention, continued use of the steam-air
jets and quick-action blowers has further demonstrated that
locomotives thus equipped may be kept comparatively free
from smoke, provided the engine crews are properly in-
structed and carry out such instructions at all times. The
report also presents a brief description of the Joint Smoke
Inspection Bureau of the railroads operating in Chicago, and
states that the record books of the City Smoke Department
show a reduction in density of railroad smoke from 22% in
1910 to 7', in 1914. The committee on locomotive boilers rec-
ommended rules for determining stresses in such apparatus.
These rules are the result of an analysis of existing practice
of a number of representative railroads and locomotive
builders. Since fuel economy depends not only upon the use
of locomotives designed to have maximum efficiency, but to
a large extent on their proper operation, the Committee on
Fuel Economy presented a standard manual of instruction
for enginemen and firemen. It is intended that thte manual,
while embodying all the essential points of efficient locomo-
tive operation, should be brief and free from technical data.
Superheaters, properly maintained and efficiently operated,
are by far the most valuable mechanical aid to fuel economy
ever applied to locomotives, and by their use savings of from
20 to 25 per cent, in coal and water are obtainable. The com-
mittee believed that to obtain the best results from the
superheater a temperature indicator is desirable. The Com-
mittee on Boiler Washing gave an outline of the general
practice of washing locomotive boilers. Many railroads have
found that the use of hot water for boiler washing results in
a saving of time, water and fuel. Chemical means of pre-
venting incrustation are largely used. The chemicals are
placed either in engine or wayside tanks, preferably the lat-
ter. The use of water-softening plants has resulted in an
average increase in mileage between flue-setting and boiler
repairs of over 100 per cent. In a paper on "Variable Ex-
haust," J. Snowden Bell stated that while these devices have
effected an economy in fuel, none has proved sufficiently
satisfactory or desirable, and it is not believed there are any
at present in railroad service in the United States. In Europe,
however, the early introduction of the variable exhaust has
been followed by its general application. As an appliance
designed to operate in the direction of economy of fuel, the
variable exhaust merits careful consideration. If this be
given, no doubt a variable exhaust can be produced to satisfy
the requirements; that is to say, it would be properly con-
structed, automatically operable and fool-proof because inde-
pendent of the human factor.
DYNAMOMETERS. By F. J. Jervis-Smith and Charles V.
Boys. D. Van Nostrand Co., New York. Cloth, 267 pages;
5^x9 in.; 119 illustrations. Price, $3.50.
DISTRICT HEATING. By S. Morgan Bushnell and Fred B.
Orr. Heating and Ventilating Magazine Co., New York.
Cloth, 290 pages; 6x9% in.; 82 illustrations; tables.
Price, $3.
LOCATION OF CARBURETION TROUBLES MADE EASY.
Chart arranged by Victor W. Page. Published by the
Norman W. Henley Publishing Co., New York, 1915. Price
25c.
A plate showing a typical gasoline system as applied to an
automobile motor, with a section through the carburetor.
Motor troubles traceable to poor carburetion are diagnosed
and the remedies prescribed; also general directions are in-
cluded for the adjustment of carburetors. The automobilist
will find the chart very useful.
HANDBOOK OF MACHINE SHOP MANAGEMENT. By John
H. Van Deventer. Published by the McGraw-Hill Book
Co., New York. Cloth, 374 pages; 4x6 ?4 jn.; 244 illustra-
tions. Price, $2.50.
This book is a careful effort to collect the best available
information and data upon the details of management and
to present them in concise form for the convenience of man-
agers of machine shops and similar undertakings. To use the
author's analogy, the book bears the same relation to those
treating of systems of management that a book giving the
fundamental data bears to books on the general theory of
machine design. There is little that is speculative, and the
information for the most part relates to data and elements
S66
P 0 vY E R
Vol. 41, No. 25
3f management that have been tested in actual practice. The
book is arranged in handbook form, with seven sections.
Under Section I are collected material and data on organiza-
tion and system. Details pertaining to drafting-room systems,
standardization of drawings and filing methods are given
in Section II. The information in Section III relates mainly
to the selection and installation of equipment, while Section
IV contains data on shop and production orders and methods.
Section V deals with timekeeping, payroll methods and
cost-keeping. In Section VI are given data on shipping,
transportation and tracing methods. In the last section
information on safety mechanism, fire prevention and sanita-
tion is given. While the beginner will find much of interest
and profit in the book, because of the necessarily abbre\ iated
treatment it will prove of more value to those "who have
already given some attention to these matters, and who can
therefore use discrimination in selecting material.
EL INGENIERO T CONTRATISTA
The title given applies to a new Spanish engineering pe-
riodical, the first number of which was issued in June. While
the publication is begun in a small way, it is hoped to make
it really useful in advancing the interests of American engi-
neering practice in Spanish-America. It is published by Dod-
well & Co., Ltd., 135 Front St., New York City.
McNab & Harlin Mfg. Co., 55 John St., New York. Bulletin.
Regrinding valves. Illustrated, 20 pp., 5x7 in.
Scranton Pump Co., Scranton, Penn. Bulletin No. 102.
Duplex plunger pumps. Illustrated, 12 pp., 6x9 in.
Link-Belt Co., Philadelphia, Penn. Bulletin No. 221. Cir-
cular storage system for storing coal, etc. Illustrated, 4 pp.,
6x9 in.
Chicago Pneumatic Tool Co., Fisher Building, Chicago, 111.
Bulletin No. 34-U. Instructions for installing and operating
Class N-SP fuel oil driven compressors. Illustrated, 24 pp.,
6x9 in.
Elliott Co., 6910 Susquehanna St., Pittsburgh, Penn. Bul-
letin L. Reducing valves. Illustrated, 8 pp., 6%xl0 in.
Bulletin M. Balanced valves. Illustrated, 4 pp., 6y>xl0 in.
Gifford-Wood Co., Hudson, N. Y. Bulletin No. 17. Pivoted
bucket carrier for conveying coal, ashes, etc. Illustrated,
16 pp., 6x9 in. Bulletin No. IS. Adjustable car loader for
handling ice, house ice cutter. Illustrated, S pp., 6x8 in.
The Sullivan Machinery Co., Peoples Gas Building,
Chicago, 111., has moved its Boston office from 35 Federal St.,
to Room 1010, Unity Building, 1S5 Devonshire St.
The Kern Commercial Co., 114 Liberty St., New York,
has received an inquiry from a client in Scandinavia for
various steam specialties, such as lubricating apparatus and
cups, injectors? valves, manometers, etc. The company is in-
viting figures.
The Terry Steam Turbine Co., Hartford, Conn., has ap-
pointed Joseph Battles as district sales manager for Denver,
covering States of New Mexico, Colorado. Wyoming and the
western portion of Nebraska. Mr. Battle's address is 326 First
National Bank Building, Denver, Colo.
The Mcintosh & Seymour Corporation, Auburn. New York,
has appointed V. E. Raggio, 1107 Nevada St., El Paso, Texas,
to represent the company in Arizona, New Mexico, Texas west
of a line drawn north and south through Del Rio. and the
States of Sinaloa, Sonora. Chihuahua, and Durango, in Old
Mexico.
The Ingersoll Rand Co., 11 Broadway, New York, has
recently issued a catalog, form 3031, descriptive of the new
"Ingersoll-Rogler" Class "FR-1" Steam Driven Single Stage
Straight Line Air Compressors. The catalog is profusely il-
lustrated showing the details of the machine in section and
is sent on application.
Wi
Ice Making Plants in the I". S. — We are advised by the
editor of "Ice and Refrigeration" that the number of ice-
making plants in the United States is not 12,500, as given on
page 659 of our May 11 issue, but 1245, as given in the "Ice
and Refrigeration Blue Book."
The World BeNtoivs Bis Prizes, both in money and honors,
but for one thing. And that is initiative. Initiative is
doing the right thing without being told; but next to do-
ing the thing without being told is to do it when you are
told once. Next, there are those who never do a thing until
they are told twici uch get no honors and small pay. Next,
there are those who do the right thing only when necessity
kicks them from behind, and these get indifference Instead of
honors, and a pittance for pay. — Elbert Hubbard.
ATLANTIC COAST STATES
It is reported that the Athol Gas & Electric Co., Athol,
Mass., contemplates extending its transmission lines to Peter-
sham, Mass., if sufficient business is guaranteed. The esti-
mated cost of building the line and installing the distribution
system is from $10,000 to $15,000. George MacKnight, Athol,
is Supt. and Ch. Engr.
The City Council of West Newbury, Mass., is considering
the installation of a municipal electric-lighting system. The
present service is furnished by the Newburyport Gas & Elec-
tric Co.
It is reported that the City Council of Lindenhurst, N. Y.,
is considering the installation of an electric-light plant in
connection with the municipal water-works system.
The Diamond Match Co., Oswego, N. Y., has awarded the
contract for the construction of its new power house in
Oswego. The equipment will include two 500-hp. boilers
(with space for a third one of the same size) and two 1000-kw.
generators. The boilers will be equipped with automatic
stokers.
SOUTHERN STATES
It is reported that contracts will soon be awarded by the
Town Council of Dayton, Va., for the installation of a muni-
cipal electric-light plant. Bonds to the amount of $24,500
were recently sold for this purpose and the construction of
a sewer system.
The People's Light, Heat & Power Corporation. Westpoint,
Va., contemplates the construction of an addition to its plant
and the installation of another unit. Samuel MacWatters is
Supt.
The City of Hertford, N. C, is considering a bond issue of
$12,000, the proceeds of which will be used for the installation
of a municipal electric-light plant.
The City of Warsaw, N. C. has granted a franchise to
Oliver Pettit, Clinton, N. C, for the installation and operation
of an electric-light plant.
Plans are being prepared for the construction of a muni-
cipal electric-light plant at Ucala, Fla., estimated to cost $75,-
000. H. C. Sistrunk is City Clk. Twombly & Henney, 55 Lib-
erty St., New York, N. Y., is Engr.
The City of White Castle. La., will install a municipal elec-
tric-light plant to cost about $25,000. Xavier A. Kramer, Mag-
nolia, Miss., is Engr.
It is reported that E. B. Jones and John E. Green are in-
terested in the establishment of an electric-light plant at
Crossville, Tenn.
It is reported that E. H. Crump, Mayor of Memphis, Tenn.,
is agitating a project to build or buy a municipal electric-
light plant. A bond issue of $1,500,000 is said to be available
for the purpose.
The Commercial Club of Harlan. Ky., is reported to be
promoting the establishment of a $250,000 electric plant in
Harlan, to be built by an association of Cincinnati capitalists.
CENTRAL, STATES
It is reported that the Canton Electric Co., Canton, Ohio,
has purchased a site for the construction of an addition to its
power station. The company has authorized improvements
to its system to cost about $250,000. W. C. Anderson, Canton,
is Mgr. and Supt.
The Board of Education of Cincinnati, Ohio, Charles Hand-
man, Business Mgr., has engaged an engineer to prepare plans
and estimates of the cost of installing electric generating
stations in a number of the larger school buildings of the
city.
A special election will be held June 22 at Painesville, Ohio,
to vote on the question of issuing $35,000 in bonds for the pur-
pose of improving the municipal electric-light plant.
The Ohio Light & Power Co., Tiffin, Ohio, has made appli-
cation to the City Council of Granville, Ohio, for a franchise
to supply electricity for domestic and commercial purposes in
the latter place.
C. C. Outland, Mayor of Zanesfield. Ohio, and E. Huntzinger,
Piqua, are preparing to organize a company to install and
operate an electric-light plant in Zanesfield.
It is reported that the Mohawk Mining Co., Calumet, Mich.,
plans to install an electric-light and power plant.
WEST OF THE MISSISSIPPI
According to press reports, bids will soon be asked for
the installation of a municipal electric-light plant in Daven-
port, Neb. Charles F. Sturtevant, Holdredge, Neb., is Consult.
Engr.
At a recent special election in Tekamah, Neb., the citizens
\oted to issue $15,000 in bends to be used for extending the
municipal electric-light plant to furnish 24-hr. service. M. S.
McGrew is Secy, and Cont. Agt. of the plant.
It is reported that arrangements are being made for the
installation of an electric-light plant in Michigan, N. D.
The Town of Chilhowee, Mo., has voted a bond issue of
$6SU0 to be used for the installation of a municipal electric-
light plant.
It is reported that W. B. Rollins & Co.. Midland Bldg., Kan-
sas City, Mo., is preparing preliminary plBns for the installa-
tion of a municipal electric-light plant at Harrisonv ille, Mo.
The estimated cost is $15,000.
It is reported that the Sterling Consolidated Electric Co..
Sterling, Colo., will shortly install a 250-kw., three-phase. 60-
cycle. 2200-volt generator and engine. The company will
purchase stokers for three boilers, poles and wire. H. L. Titus
is Mgr.
POWER
Vol. II
NEW YORK. JUNE 39, 1915
No. 26
Tlhaft P
lL©S\dl
PiroIbJeiM
>v Beeton Bralet
WE'VE rustled for power contracts and landed a lot as well,
We've hunted the country over for fancy outfits to sell.
We've peddled electric irons, we've boosted electric pots,
And gathered up fans and sold 'em in regular carload lots,
We've hinted and preached and threatened and advertised year on year
And talked to the folks like Uncles and written 'em plain and clear,
But in spite of our ceaseless efforts, our labors almost sublime
Full half of our power units are idle most of the time.
And that's the fault of peak load
(It never is a weak load)
Which jumps upon the backs of us at certain times of day
A bold and not a meek load,
A make-you-swear-a-streak load,
Oh, if it weren't for peak load our labor would be play.
THE sun goes down in the western sky and the stars come into sight,
And the homes of the busy city are drawing on us for light,
The theaters glow in glory, the signs and the street lights glare,
And here at the central station we've worry enough tc spare,
For the straining boilers tremble, the laboring engines throb
And we start up the whole equipment to handle the heavy job.
It's trouble enough on week days to manage the problem well
And then when Saturday Night comes round — say, SATURDAY night
is Hell!
And so we cuss the peak load
The big load, the freak load,
Which jumps upon the backs of us at certain times Oi day,
A strong and not a weak load
A make-you-swear-a-streak load,
Oh, if it weren't for peak load our labor would be play.
IF only the load were steady each hour of the twenty-four
We wouldn't be fretting and fuming and figuring any more
On boosting the "off hour ' business by every kind of scheme;
But the peak load still is with us and life is no idle dream.
For all of the new inventions we've brought to the public's view
Electric curling irons and vacuum cleaners, too,
For all of our advertising, our urging in prose and rhyme,
Full half of our power units are idle most of the time.
And that's the fault of peak load
(It never is a weak load)
Which jumps upon the backs of us at certain times of day,
A not at all unique load
Yet, in a way, a freak load
Oh, if it weren't for peak load our labor would be play.
868
P 0 W E K
Vol. 41, No. 26
Imig'tomi Avenge Power P
ScraimtoinL, Pemnnio
T>y Warren 0. Rogers
SYNOPSlS—i n r, modeled at a
cost of $2,000,000. sir new water-tube boilers,
each with 5580 sq.ft. of heating surface, hare been
installed. Tlie generating anils consist of three
turbo-generators and tiro reciprocating eng\
driven anils, the latter exhausting to a district
heating system during cold weather. Culm /<<< ;
having an average calorific value of 10.300 B.t.u.
is burned in the boiler furnaces. This fuel has
been through the washery twice on, I contains ap-
proximately 5.02 per cent. \ Iter, 74.98
per rent, fixed carbon and 20 per eeat. noncom-
bustible matter. At _/<;.; per rent, of boiler rating
6.01 lt>. of water i I from and at 212 deg.
in the old boiler plant. A ' ■ new
boilers gi\ . of water
from and at 212 d<-<j.
The City of Scranton, Penn., is situated in the heart
of the Lackawanna Valley, one of the greatest anthracite
producing regions in the country. The mines are dotted
here and there all along the valley ami range in size from
those requiring 50 it 100 hp. in their operation up to
those requiring from 2000 to 3000 hp. Many, in fact
most, of these mines still use steam power and their elec-
trification is for the future.
Naturally, in this region the greatest competitor of a
central station is cheap coal, and in order to obtain and
keep its business it must be in a position to sell electrical
energy at an attractive rate and to give reliable service.
When the American <Jas & Electric Co. took over the
Scranton properties eight years ago, there were six com-
panies supplying electric service from four generating
stations to consumers, the combined yearly output of these
plants being about 11.000,000 kw.-hr. Today the yearly
output of the company generated in its two stations is
more than 60.000.000 kw.-hr., which is distributed over
70 square miles, furnishing current to 16 cities and bor-
oughs, ranging from 200 to 130,000 in population.
The old properties were becoming obsolete, and to meet
the increasing business both for the present and for the
Fig. 1. General View of the Xew Washington Avenue Tower Plant, Scranton, Penn.
June 29, 1915
POWE i;
8G9
future the suburban power plant on Washington Ave. has
been rebuilt with the exception of the old boiler room.
The new power house is 200 II. Long, o'l ft. wide and 3"!
ft. high to the steel roof trusses. The basement is 11 l't.
6 in. deep and contains the condensing apparatus. A new
fireproof boiler house 120 ft. Long, 115 It. wide and 40
ft. high to the roof trusses, forms an ell with the old
building.
The plant, before being remodeled, contained three 300-
kw. alternating-current generators, two being belt-driven
from two engines, from which alternating current was
secured, and one was motor driven. These units were run
separately with a total Load of L200 Lew. The old station,
with its belt-driven units, was typical of the old-time
plant.
New Turbine Hoom
A view of the present turbine room is shown in Fig. 1,
two of the three units being in the foreground. There are
two Curtis-Rateau 10,000-kv.-a. horizontal turbo-gener-
ators and one 4500-kv.-a. unit, both generating current
at 4000 volts.
Two of the orig-
inal 3500-hp. en-
gines are retained.
One, a cross-com-
pound with cylin-
ders 36&66x48 in.,
is directly con-
nected to a 4000-
volt, 2000-kv.-a.
three-phase, 6 0-
cycle alternator,
and runs at 100
r.p.m. This en-
gine is arranged
to run condensing,
to the atmosphere,
or to exhaust into
a heating system
working against
an average back
pressure of 8 lb.
The other recipro-
cating unit is a
twin engine with
cylinders .'!<1\ 18
in., and runs at
100 r.p.m. It is
directly connected
to an alternator of
the same size as
that of the com-
pound unit. This engine, which has been in service about
four years, is designed to opi insi a tO-lb. hack
pressure, as that was the pressure carried on the com-
mercial heating system at the time it was installed. The
weight of each flywheel is 65 tons.
The compound engine is piped to a surface condenser
containing 6000 sq.ft. of cooling surface, or 1.7 sq.ft. per
h]i. The volute circulating ami the hotwell pumps in the
basement are turbine-driven. The 8x20xl2-in. air pump
is on the main floor. The condensers lor the turbines are
connected by expansion joints. The 10,000-kv.-a. turbine
condenser has 30,000 sq.ft. of cooling surface, or 2.66
sq.ft. per kw. The condenser for the latest 10,000-kw.
Fig. 2. Combined Fan and "Natural-Draft Coolixc: Towkrs
turbine installed is of the usual design, hut it has a
a] arrangement of the tubes. It contains 150,000
sq.ft. of cooling surface, or :; sq.ft. per kw. of turbine
capacity. That For tin1 t500-kv.-a. unit has 11,000 sq.ft.
of cooling surface, or :i.] sq.ft. per kw.
The 20- ami the 28-in. triplex volute circulating pumps
lor both condensers are turbine driven, and are on bhe
main floor, as are also the L2x30xl6-in. ami the 8x20x12-
in. dry-air pumps for the L0,000- and the t500-kv.-a.
units. A \ .- 1 1 1 1 1 1 1 1 1 within 2 in. of the barometer is main-
tained with injection water al 70 deg., ami within 3 in.
ai 80 deg. I'.
Circulating water flows to the pumps by gravity from
eight cooling towers at the rear of the plant and 50 ft.
above the basemen! floor. The return water is through a
42-in. diameter cast-iron pipe, and is controlled bj motor-
driven valves.
Cooijnc Towers
The cooling towers. Fig. 3. are of the combination fan
and natural-draft type. They are built over a covered
concrete reservoir
with com rete col-
umns extending
above the reservoir
on which the tow-
1. and leav-
ing openings be-
tween the columns
for the entrance
of air when the
towers are oper-
ated on the stack-
d r a f t principle.
The air spaces he-
low the towers are
separated by con-
crete aprons ex-
tending from the
under side of the
top of the reser-
voir down to a
point below the
water level, thus
making each tower
independent of the
others, so far as
opera i ion is con-
cerned. The stacks
are I milt of sheet
steel riveted and
are cylindrical in
form, the lower
parts being "-' I ft. m diameter ami the towers 70 ft. high
from the top of tin je supporting piers.
Each tower is provided with two 10-ft. diameter fans
mounted on one shaft and driven by a motor in a concrete
housing close to the tower. The cooling surface consists
of dressed cypress board's Bel i dee. each course being
arranged al righi angles to the course below.
Warm circulating water is brought to each tower
through a 14-in. discharge pipe entering at a point ju-t
above the fans ami extending up through the center of
the tower to a point just over the cooling surface. On
the top of this discharge pipe is a self-rotating water dis-
tributor, which is revolved by the reaction of the jets of
870
POWER
Vol. 41, No. 26
circulating water and rotates on a lignum-vitee bea
which, being lubricated by a part of the circulating water,
requires no attention.
The special openings between the supporting piers at
the base of the tower are provided with steel doors hinged
8 i * •' V*
4
Fig. 3.
Two Coolixg Towers, Capacity 5000
Peb Min.
Gal.
at the top and partly counterweighted with chain and
weight to facilitate opening and closing. The lower part
of the tower can be entered through one of these draft
doors, and the distributor and upper part of the cooling
surface are accessible through a door arranged at the side
of the stack. A ladder extends from the ground to the
top of the tower, passing close to the platform in front of
the upper opening.
This battery of towers is capable of cooling the circulat-
ing water from the condensers serving a power plant of
14,500 kw.. when maintaining a vacuum within 3 in. of
the barometer, and during summer weather conditions
with forced draft.
In cold weather, or when the load on the power station
is light, the fan- are stopped, the draft doors are opened
and the towers allowed to operate on a stack-draft prin-
ciple, thus saving the power accessary to operate the
fans.
There are also two natural-draft cooling towers work-
ing in connection witli a 10,000-kw. turbine. These towers
are shown in Fig. 3. They are about 250 ft. long, and
100 ft. high, and are of the all-wood natural draft type,
built under a license from the Balcke Co. of Germany.
So far as known, these are the largest natural-draft cool-
ing towers installed in the United States.
The condensate and circulating pumps are mounted
on a single bedplate and driven by a steam turbine
through a common shaft. Pig. 4 shows the unit in part.
The pump A is a combined hydraulic-air and conden-
sate pump. There is but one connection to the con-
denser— the condensate and Don-condensible vapors being
separated in this pump. In case the hurling water used in
the air pump becomes too hot it can be cooled by city
water.
The centrifugal circulating pump B is of standard
type. An interesting teeming this installation, as
shown by the readings for a day herewith givpn, is that
the vacuum is better than 29 in. practically throughout.
1 1 is understood that this showing is a record in this
country, and there are no data available from for-
eign plants showing such results. The readings are as
follows :
SCRAXTOX ELECTRIC COMPANY Feb. 25, 1915
1
O
Q
-I
=
5
—
ll
|
o
C
a
71
3400
55
63
60
3S
29 24
50
51
38
50
1500
:.:-;
59
57
36
29 25
48
4s
38
48
1500
aooo
51
;...
53
36
28 25
46
47
38
47
1500
800
V.i
51
36
29 44
46
47
.-in
47
1500
sMI
40
v
47
36
29 4S
45
46
off
1500
800
44
4,j
45
34
29 4S
47
47
o:T
3200
46
.,:;
Is
32
29. 4S
49
50
38
50
3800
50
58
58
32
29.25
47
4s
;>s
50
1
61
57
35
70
29 3
50
51
38
50
.V.I III
64
61
32
70
29 24
.54
56
38
53
4 Mill
55
65
62
34
70
29 24
58
OS
38
57
! si in
56
i;n
63
34
70
29 29
56
38
56
5600
5T
62
64
36
70
29 20
55
56
38
55
ii
56
66
63
36
70
29 24
53
54
39
53
5400
''-
64
36
29.19
58
59
38
57
5400
57
67
67
35
29 19
58
59
38
50
0000
59
70
68
.;-,
27 14
53
38
48
Hi inn
58
69
67
35
70
29 19
-n
52
38
48
5200
57
6s
65
32
29 2)
48
50
38
47
SOOO
59
78
70
30
29 1
51
53
39
49
sooo
59
70
72
30
29.05
52
56
39
49
The combined condensate and turbo air pump* is
driven by the same auxiliary turbine that drives the
circulating pump. This arrangement is compact and
requires less attention than the general arrangement of
condensing apparatus. The exhaust steam from the
pump turbine is connected to the second stage of the
10,000-kw. turbine. The exhaust pipe from the pump
turbine is fitted with an automatic trip throttling valve
close to the connection to the large turbine. There is
also a back pressure valve set at 15 lb. pressure absolute.
The pressure in the first stage of the turbine is 30 lb.
and that of the second stage is 13 lb. absolute, therefore
the exhaust steam enters the second stage of the large
turbine at a pressure of 2 lb. above that existing in that
Fig. 4.
Turbo-Air axd Coxdexsate Prap on Shaft
WITH ClRCrLATIXG PfMP
portion of the turbine. In the near future the exhaust
steam from the other turbine auxiliaries will be con-
nected to their respective turbines and the exhaust steam
used in the second stage. »
The makeup water is taken from the city water
mains. The feed water is taken from one 4000-hp. open
•Details of a test of one of these air pumps were published
on page 442 of the Mar. 30, 1915, issue.
June 29, 1915
TO W E K
871
Fig. 5. A Long Line of Motor-Driven Units
heater by two 16xl0xl8-in. outside-packed pumps con-
trolled by a pump governor and from one 5000-hp. heater
by two 500-gal. capacity centrifugal boiler feed pumps.
Exhaust steam from the auxiliaries is used for heating
the feed water, all, with two exceptions, exhausting into
a common header. The circulating pumps on the 10,000-
kv.-a. turbine units are arranged to run either condens-
ing or noncondensing, assuming that with both main tur-
bines in operation more than enough exhaust steam would
be obtained for feed-water heating.
Auxiliaries
Along the switchboard side of the turbine room is a row
of motor-driven units, shown in Fig. 5, consisting of the
following :
Two 1400-hp. synchronous motors directly connected to
two 1000-k\v., 550-volt railway generators, speed 514 r.p.m.
These units have a 125-volt exciter mounted at one end of
each shaft.
Two 250-hp., 4000-volt synchronous motors, each directly
driving tin 6.6-amp. arc-light machines at 514 r.p.m.
One 186-hp., 4000-volt synchronous motor directly con-
nected to two 6.6-amp. arc-light machines at 514 r.p.m. mo-
tor circuits.
One 150-hp. induction motor driving 100-kw., 250-volt,
direct-current generator at 580 r.p.m.
One 300-hp. induction motor driving a 200-kw., 250-volt,
direct-current generator at 580 r.p.m.
There are three exciter units: One is a 150-kw., turbine-
driven set generating 125-volt direct current at 3775 r.p.m.;
one is an induction. 250-hp. motor-generator set generating
125 volts at 720 r.p.m.; and the third is a lO&lSxlO-in. ma-
rine engine directly coupled to a 150-kw., 125-volt, direct-
current generator, at 340 r.p.m.
BOILER Roo.M
The old boiler room contains only water-tube boilers,
of which four arc of 180-hp. capacity, four 600-hp., and
Fig. 6. One of the New Double-Deck Boilers
Section through One oi the IIoilkrs
five 300-hp. The eight largest arc equipped with dutch-
oven furnaces and dumping grates. The five small ones
have shaking grates. All are equipped with regulators,
and but two have superheaters.
In the new room. Fig. 6, there are six special-type,
double-deck, water-tube boilers with two hanks of 18-19-
ft. tubes, each IS seel ions wide: the upper one is 10 and
the lower 5 i ulies high. These boilers arc double-end
and are at present baud bred. Mechanical stokers are to
lie installed in the near future capable of handling the
grade of fuel now being burned. Each boiler contain
5580 sq.ft. of heating Burface and is rated a1 558 lip. The
grate surface is 217 sq.ft., which gives 2.51 sq.ft. of heat-
ing surface per square fooi of grate surface. Washed
buckwheat and anthracite culm are used.
872
POWER
Vol. 41, No. 26
Fig. 7 is a section through one of the new hoilers.
Forced draft is used, the main air duct being between
Following are the results of teste recently run on two of
these boilers :
BOILER TESTS AT THE WASHINGTON AVENUE PLANT
Boiler: Babcock & Wilcox W.S.V.H. Special. 18 Sections, 10 High,
18-ft. Tubes.
18 Sections, 5 High. 19-ft. Tubes. Two 42-in.
)rums — 5580 sq ft
H S.-Rat-
ing 558 hp. Babcock & Wilcox Superheater — Furnace Double End. Hai
d-fired. 217
sq.ft. G.S.
Coal: Washed Buckwheat No. 2 — Slush — Bituminous — "Shawmut
Aug. 19, 1914
Hr. 8.07
Washed
Aug. 21, 1914
8 00
Slush
Aug. 24, 1914
8.17
90% slush
Aug. 25, 1914
S 00
7092 washed
—30% slush
Aug. 27, 1914 Ac
8.00
10% soft—
90% washed
. . 1914
8.00
W ashed
Lb.-Sq.In.
Deg. F.
Deg. F.
Deg. F.
156.00
437 20
68 30
64.00
155 00
439 90
71.40
65 50
154 00
445 70
77.70
65.00
157.00
445 00
75.60
65 30
158 '»i
441.60
71 70
65 00
158.00
437.80
67 90
65.00
Lb.
Lb.
1 2408
237. 523
294.719
1.2408
173.634
215, 445
1 2447
214.563
267,067
1 2437
226,173
281,291
306.720
380,946
1.2399
285,960
354,618
Water per hour from and at 212 d»'Lr
Lb.
36,520
26,931
32.6S9
Lb.
Per Cent.
41,793
9 50
45,600
16 35
4S.400
16 47
51,960
12 79
8.49
7.56
Lb.
Lb.
37,823
11.351
38,122
14,941
40,429
13,092
45.314
17,039
12.0S9
45,111
12,066
Per Cent.
1.24
0 12
2.86
Lb.
11.210
14,923
12,729
16.998
12,009
12,042
Lb.
128
406
501
Lb.
Lb.
Lb.
Per Cent.
280
11.490
26,333
30 38
1,377
16,300
21322
42 76
1,540
14,269
26,160
35 29
1,602
18,600
26,714
56 74
12,674
33,447
27.48
1,035
13,077
32,034
28.98
oi H.O
0 43
0 53
0 50
0 52
0 55
0.49
n. of H,0
0.04
0.06
+li 'il
+0 01
+0.03
+0.01
Draft in furnace { ^£nt
n. of H.O
0 14
0 12
0 08
0.06
— 0 02
—0.06
n. of H.O
n. of BlO
0 15
1.46
0 12
2.09
0.09
1.88
0 09
2.68
— 0 02
1.83
0 07
Pressure in ash pit {j^t-""
1.74
n. of H.O
Deg. F.
1 41
513
1.81
485
1.87
511
2 46
520
1.82
544
1.65
535
Deg. F.
Lb.
91
23.98
26 39
84
27 43
SO
30.07
S2
29 17
80
28.24
Lb.
21.70
22 06
22 91
26 22
26 69
26.11
Lb.
6.50
4.80
5.90
6.30
8.50
7.90
Actual evaporation per lb. of coal as fired
Lb.
5.68
3.81
4.43
4 35
6.09
Equivalent evaporation from and at 212 deg. per lb.
Lb.
7.79
5.65
6 61
6 21
S.26
7.86
Equivalent evaporation from and at 212 deg. per lb.
Lb.
Per Cent.
Per Cent.
11.19
1058 50
189.70
65 54
9.87
780 6
139 90
52.57
10.21
947 50
169.80
61 56
1019 10
182 60
57 71
13S0 20
247 30
66 61
12S4 60
230 20
64.79
Per Cent.
76 19
67 48
70 27
71 99
76 07
74.59
Gas analysis CO, P.
r Cent. Vol.
12 00
9.10
10 20
9 70
13 20
13 00
O,. ..... . Pt
r Cent. Vol.
7.. 50
10 70
9 40
9.40
6.40
6.70
CO... Pi
r Cent. Vol.
0 00
0 00
0 00
0 00
Trace
Trace
N. . . Pe
r Cent. Vol.
80 50
80 20
80.40
80 90
80.40
80.30
Per Cent.
9 50
16 35
16 47
12 79
8.49
7.56
Per Cent.
8.98
9 60
11 87
9 34
10 05
9.44
Per Cent.
Per Cent.
Per Cent.
71.94
19.08
11,533
14,252
1 24
63 SS
26 52
10,430
14,194
0 12
62.03
26 10
10,420
14,100
2.86
64 22
26.44
10,441
14,194
0 24
72.77
17.18
12,034
14,530
0 66
72 30
18.26
11,772
14,401
0.20
Per Cent.
1.96
2 56
2 00
1 24
1.12
2 64
Per Cent.
36 16
38 92
27.20
37 70
38.44
39 06
Ash
Per Cent.
61.88
58.52
70 80
61.06
60 44
58 30
the ash hoppers and opening to a blast box which is
equipped with hand-operated dampers for controlling the
volume of air admitted below the grates. The staggered
arches are 18 in. wide and spaced 15% in. This arrange-
ment is to provide a baffling which, with its high tempera-
ture, will cause the furnace gases to burn before striking
the comparatively cool tube surface: also, to diffuse the
heat currents so that they will reach the heating surface of
the lower bank of tubes from end to end.
This method of arch construction has developed trouble
in that the arches have been found difficult to keep in
place. To preserve them in place a pillar "2x4 ft. in size
has been built between the bridgewall and an arch 11
ft. long, 9 ft. high and 6 ft. cross-section, and arched
15 in. at the center. This arch replaces the bottom
one, Fig. 7, and the brick column has proved satisfactory.
The six new boiler furnaces will be so equipped.
Resting on the top row of the lower bank of tubes is a
tile baffle wall, which extends 10 ft. 9 in. from the lower
end of the tubes. The upper bank is baffled for three
passes of the gases, the superheater being placed between
the first and second pass.
In order to facilitate cleaning the space between the two
banks of tubes, provision has been made to remove the
dust to the ash hopper through a 10-in. dust chute. Dust
from the stack is taken care of by an S-in. chute which is
brought down to a point convenient for discharging into
a tile drain running to the ash accumulating pit.
The capacities secured in the tests are interesting in
view of the poor quality of coal used, and this is also true
of the efficiencies. Heat balances which have been worked
out from three of these tests show the following results :
11.71
10.91
0.33
0.46
0
0
25.22
15.18
5.44
5.52
Aug. 19 Aug. 21 Aug. 28
Heat absorbed by boiler 65.54 52.57 64.79
Loss due to moisture in coal 1.02 1.92 0.S0
Loss due to burning hydrogen .... 2.35 -.71
Loss due to chimney gases 11.31
Loss due to moisture in air 0.54
Loss due to incomplete combustion. 0
Loss due to carbon in ash 14.62
Loss due to radiations, etc 4.62
Air assumed to have 60 per cent, saturation in all cases.
Air for the forced draft in the old boiler room is
supplied by two 14-ft. and one 10-ft. steel-plate blowers
and in the new boiler room by two turbo- and one motor-
driver, fan. Ashes and soot in the old boiler room are re-
moved and discharged into a tank 70 ft. above the base-
ment floor, by means of a 5-ft. exhaust fan which runs at
a speed of 1440 r.p.m. and is driven by a 100-hp. motor.
Ashes from the new boilers are dumped from the hop-
pers into half-round tile drains in which they are flushed
by mine water into a pit. from which they are taken by
a crane and loaded into railroad cars (Fig. 12).
An interesting method of getting rid of ashes from this
plant was used about two years ago. As, is well known,
under the City of Scranton are many coal mines that have
been worked out to a large extent, and this power plant is
over a mine, the top vein of which is about 130 ft. below
the surface. Pillars had been left to support the roof.
June 29, 1915
po w k i;
873
8. Culm Bank and Scraper Conveyor
huge piles is being reclaimed by passing it through wash-
eries, and is sold in the market in the various sizes of
buckwheat. The fine dust, dirl and bone were looked
upon as of m> particular value, and in some cases were
discharged to any stream handy or returned to a bank
For rewashing.
The tin I used at the Scranton suburban plant has been
through the washing process twice and is so line that a dxy
sample taken from the bank and passed through a rV
and over a ' ( -in. mesh screen gives 8 per cent.; through
a %-in. and over a 's-in. mesh, <i per cent.; through
1 § in. mesh, or dust, gives 76 per cent.. An approximate
analysis showed volatile combustible matter 5.02 per cent..
fixed carbon 74.98 per cent., noncombustible matter 20
per cent., ami a calorific value of 10,500 B.t.u.
This fuel is so fine and dust-like thai it is accessary I"
thoroughly wet it before firing to prevent its being carried
over back of the bridgewall before it has bad a chance to
become completely ignited.
Fig. 9. Ci i.m Bank, Electrically Operated Jib Crane and Crusher House
To prevent the ground from settling under the plant, two
8- and one 10-in. bore holes were dialled through to the
three veins, which were worked1' out, and the ashes from
the boilers were flushed into the chambers and' passages ;
thus making a solid support for the plant.
It is proposed to return to this method of ash dis-
posal as the companj has about 30 acre- of mine surface
which is available for filling in. A bore-hole will be
drilled in one corner of the ashpit and the ashes Hushed
to the abandoned mine. There will also be an ash-
storage tank of a size to hold about si.\ days' ash
accumulation. This is so that the contents of the ash
basin and that of the bin can be sent to the mine at
one flushing and so decrease the labor cost, as it. is nec-
essary to emploj men at the outlet of the Hushing pipe.
It is estimated that with tins arrangement one man
will do the work formerly performed by six.
Pi EL
Culm hanks are common in the anthracite region, as
up to a few years ago there was no demand for the finer
grades of anthracite. Toda} the coal contained in these
Pig. 1<>.
Scraper Conveyor Discharging to Old
Boiler House
The casual observer would hardly believe that this
grade of fuel could he burned to advantage. That it can
be utilized in a boiler furnace with good results is shown
ST4
POWEE
Vol. 41, No. 26
Fig. 11. General View of the Plant, Showing Coal-Conveying Apparatus and Water-Cooling Towers
by a test run on four 480-hp. boilers in the old boiler
room. The grate surface per boiler is 168 sq.ft., with 12.5
per cent, of air space. An air pressure of 1.72 in. of
water was carried in the ashpit, with a draft over the fire
of 0.02 in. and a draft under the damper of 0.45 in. of
water. The boiler horsepower developed was 163 per cent,
of the boiler rating, with an equivalent weight of water
evaporated from and at 212 deg. F. of 6.0? lb. per pound
of fuel.
Fuel is carried from the culm bank at the rear of the
plant by a 6-in. reinforced chain with scraper every 2 ft.
The conveyors, which travel at a speed of about 65 ft.
per min.. are shown in Figs. 8 and 10. The culm is taken
to a crusher house shown at the left in Fig. 9, and as it
contains considerable roek, it is taken to the top of the
building and dumped into a -"^-in.-mesh revolving screen.
The material passing through goes to tin- conveyor line,
Fig. L0, which discharges to tin' boiler house where it is
hand-fired to the furnaces. What does not pass through
the screen goes to a pair of 24x"21-in. chestnut rolls, and
then drups into a second set of rolls of the same size,
which reduces it to pea-coal size. It is then returned to
the elevator and passed through the screen in order to
mix it with the finer fuel coming from the culm pile. An
electric jib crane with a "2-ton clamshell bucket is used
for handling the culm from the pile to the conveyors.
Fuel for the new boiler room is obtained by rail from
another culm pile owned by the company, and is stored in
the yard close to the boiler house. Here it is handled by a
10-ton, three-motor traveling crane equipped with a two-
ton grab bucket. Fig. 11. This takes the coal from either
the cars or the bins and discharges it into a crusher, which
passes it to a 30-in. belt conveyor, Fig. 12. The latter de-
Fig. 12. Ash- and Goal-Handling Apparatus
Fig. 13. Station Switchboard
June 89, 11)15
V 0 W E R
875
posits the coal onto a 32x32-in. overlapping buckel con-
veyor, which elevates it to the top of the building and
dumps it. into either one of three S4-in. bell conveyors
that discharge into the bunkers. These conveyors have a
rapacity of about 120 tons of coal per hour and are
equipped with automatic self-reversing traveling trippers
arranged so that their travel may he controlled by hand.
Steam Heating
The exhaust-steam system of the company is one of the
largest in the Tinted States. It comprises over 15 miles
of mains ranging from 2y2 to 22 in. in size. Both the
times thai of the other, and below 10 decrees the differ-
ence in back pressure is four times greater than thai at
the illuminating plant.
One pound pressure is carried at the point of delivery
to a building. It' the pressure drops below this the engi-
neer is at once notified. With tie' beginning of the heat-
ing season, lite exhaust steam from one cylinder of the
twin engine at the illuminating plant is turned into the
beating main; exhaust steam from the compound engine
at the suburban plant is turned into the main, but the back
pressure on the low-pressure cylinder is not increased
No. Equipment
1 Turbo-generator
2 Turbo-generators.
1 Engine
PRINCIPAL EQUIPMENT <>F THE WASHINGTON AVENUE POWER PLANT, BCRANTON, CEN'N.
Size Operating Conditions
150 lb. steam, 1200 r.p.m., 4000
Engine
Gem ators. . . .
Turbo-generator.
Mi,t . >r-generator.
Horieontal, L2-etage I500-kv.-a
Horizontal, B-etagc L0,000-kv.-a
Cross-mmpnund... 36&rj6x4S-in.. 3600-hp
Twin, Corliss :iC,&:it>x-i8-in., 3-r)00-hp.
AltrrnritiiiR-current 2000-kv.-a M:
Horizontal — d -c . 150-kw Ex
A.-C. and d -
Make i
Main unit
Main units
Main unit
Main unit
Condena
Condena
Pump. .
Pump . .
Turbine
Turbine
Turbine
Turbine
Pump. .
Pump. .
Pump
Pump
Towers. .
Towers . .
Pumps
225-hp. motor, 1 50-kw.
gen Exciter for mam units
Surfa'-e UllOflsq.ft cooling surface With compound engine,
Surface 11, (KH) sq.ft. roo|inL' sur-
face With 4500-kv.-a. turbine
3ur1 20.000 sq.ft. cooling sur- With 10,000-kv.-a. tur-
fno bine
Surface 30,000 sq.ft. cooling sur-
face. With 10.0iiO-kw. turbine.
Volute 20-in With 4ooii-kv -a turbine
condenser
Volute 28-in With 10,000 kv.-a. tur-
bine condenser
Volute 10-in With cross-compound en-
gine
Single-stage Driving 20-in. pump
Driving 2s-in. pump
Driving 10-in. pum>>
Single-stage. . Driving turbo and cen.
pump
3x20x1 2-in With compound
condenser
8x20xl2-in With 4000-kw. turbine
condense]
[2x30xl6-in. . . Y\ ith 75004™ turbine
condenser
Steam-drive:
Steam -drive;
Bteani drv e
Turbo
Centrifugal.
Cooling
Mo 70.
With 10,000-kw. turbine
condenser. . . .
With 10,000-kw. turbine
condenser.
< '■ " li'i'.' i'«,ml<-iiMiiL' water
Cooling condensing water
oh-. 3-phase, 60-cycle General Electric Co.
150 lb. steam, 1800 r.p m , "
■ oH i, 3 phaa . 60-cycle l ;■ neral Electric Co
150 ll>. steam, condensing or non-
condensing, 100 r.p.m Robert WetheriU A Co.
150 lb. steam, non i
100 r.p.m Robert Wetherill A Co.
100 r.p.m., 4000 volts, 3-i
80 cycle I ieneral Electric Co.
150 lb -team, 3775 r.p.n
volts < ieneral Eli etric Co.
3-phase, 60-cycle, 4000 volts,
d.-c. 125 volts, 720 r.p.m General Electric Co
L'ii-in. vacuum — Albergei Pump A Condenser Co.
Within 2 in. of barometer, 70-
deg. injection water Mberger Pump & Condenser Co.
Within 2 in. of barometer, 70-
di g injection water Mb. rger Pump & Condenser Co
Wheeler Condenser & Engineering
29+-in, vacuum Co.
Turbine-driven, triplex. Alberger Pump & Condenser Co.
Turbine-driven, triplex Alberger Pump A Condenser Co
Turbine-driven Alberger Pump & Condensei I V
ISO lb steam Alberger Pump &• Condenser I So
150 lb. steam Alberger Pump A ( tondi d ei '
150 lb. steam ... Alberger Pump & Condensei I !o
L501b steam, 1 500 r.p.m . General Electric Co.
150 lb Bteam, ... Alberger Pump A < 'ondenser Co,
150 lb steam Alberger Pump A Condenser ( !o
150 lb steam
Turbine driven, I500r p.n
Vlberger Pump A Condenser Co
Wheeler Condenser A' Engineering
Wheel*i Condenser A Engineering
Turbine driven, 1500 r.p.m. Co
Fan and natural draft Uberger Pump & ' ondi aa r I o
Natural draft \\ heeler Condenser A Engineering
Heaters
Motor-generators.
1-2 Motors and gener
ators
1 Motor-generator.
1 Motor-generator
1 Engine
1 Generator
4 Boilers
Boiler-feed.
On boiler-feed pumps
Duplex, outside -
p li I ed I6xl0xl£ in
Kitts . .
Stilwell, open . . Heating boiler-feed u ater
Synchronous mo-
tors, d.-t gen .. U00-hp.— 1000-kw Railway service
2 -3 Motor-generators Synchronous mo-
tors, d.-c arcgen. 250-bp.. ..... .... Arc-light service
Synchronous mo-
tor, d.-c. arc gen.. 186-hp Arc-lighl service
Induction motor, 150-hp. motor, 100-kw,
d.-c. gen. ... gen. . . . Motor service
Induction motor, 30O-hp. motor, 200-kw.
d.-c gen. ... gen Motor service.
Marine... L0xl8xl0-in Drives 125-volt generator
Direct-current 100-kw Exciter unit
tube, Ster-
ling. 180-hp Steam generators
Water-tube 600-bp . . Steam generators
300-hp Steam generators.
1 50 lb. steam, automata
I fsing exhaust steam
Co
ol Si i inton Pump Co.
Kitts Mfg Co
Plat! iron Works Co
55o vo Its, 514 r p m General Electiic Co
1000 roll . 6 6 amp ,d c, ~.u
r.p.m ( ieneral Electric Co.
KXXJ volts, 6 6 amp . d -c . 51 1
r.p.m ( ieneral Electric < '<•
250 volts, d -c . 580 t p i
Westinghouse Elec. A Mfg. Co.
Blov
■ set .
Blower .
Motor
Crane
Conveyor. .
( lonveyor. .
< ton i ■ ■■■. oi ■
Water-tube.
Water-tube,
ble-deck, 558-hp Steam generator
Engine-driven . 14-ft. dia Forced-drafi
Engine-driven. . . lo-ft dia Forced-draft
Motor-driven . ">-it dia Ash-removal system
Alternating-current 100-hp - - Driving .""• - f t ash blower
Jib 2-ton Handles culm
Belt 30 in. wide v Handles coal from cars
to belt conveyor
Bucket 32x32-in Handles coal from 30-in
to 24-in. corn i
Belt 24-in wide Handles coal to bins. . .
250 volts, d.-c., 580 r.p.m. Westinghouse Elec A Mfg Co
IVi lb, steam, 340 r.p.m (Ieneral Electric <
125 volts. 340 r.p m General Electric Co.
150 lb. steam, Dutch-oven fur-
naces BabCQCk A Wilcox Co.
150 lb. steam, Dutch-oven fur-
oaces Edge Moor Iron (\>
150 lb. steam, hand-fired Heine Safetj Boiler (',,
150 lb. steam, will be Btoker-
fired Babeock A Wilcox Co.
Variable-speed \merican Blower Co.
Variable-speed American Blower Co.
Intermittent American Mower Co
Intermittent General Electric Co
Motor-operated Brown Hoisting Machinery Co.
Intermittent, motor-dr:
Robins Conveyor Belt Co.
Mead-Morrison Mfg Co.
Robins I lonveyor Belt Co
illuminating and suburban plant supply steam to the
system, and it has been found advisable to carry the heav-
iest back pressure on (he illuminating plant, which is
nearest the center of distribution. With a winter temper-
ature of 35 deg. P., the pressure at the suburban plant
is carried at twice that at the illuminating plant. With
lower atmospheric temperatures down to 1" deg., the pres-
sure gradually changes until the suburban plant has three
above 15 lb. In case it is necessary to carry more than 15-
Ib. pressure, owing to a drop in atmospheric temperature,
the twin engine is used instead of the compound. If it is
necessary to carry more than 15 11). at all times, the piston
of the low-pressure cylinder is removed, the valves are
placed in the open position, and the piston-rod hole
plugged. This allows any desired pressure to be carried.
An auxiliary supply of live steam can be had, if for any
876
POWER
Vol. 41, No. 26
cause the exhaust-steam supply should be insufficient, by
reducing the live-steam pressure from 150 to 5 lb. "With
40-lh. hack pressure about 130,000 lb. of steam is furnished
to the system per hour by the suburban plant, and about
50,000 lb. by the illuminating plant at 10-lb. back pres-
sure.
Fig. 13 is a view of the suburban-station switchboard,
and Fig. 14 the busbar compartments. The two plants
and the substations are connected by tie lines, of which
there are four between the two power stations, four from
the suburban plant to the Dix Court substation, and one
from the latter to the illuminating plant. This arrange-
ment, in connection with the motor-generator sets, makes
Fit;. 14. Busbar Compartments
a flexible combination, because in ease of an interruption
in service the motor-generator sets can lie used to generate
either alternating or direct current.
There are also two tie lines from the Dix Court substa-
tion to the Hampton power planl of the Delaware. Lacka-
wanna & Western R.R. Co., which provide a breakdown
arrangement to the advantage of both companies. The
conditions are that the Hampton plant has a heavy day
load and the illuminating company a heavy night load.
and either is supposed to help the other to the extent of
2500-kw. per hr., or more if desired when it is possible to
do so.
In building the new power house the principal problems
encountered were those of keeping the service up to the
standard and at the same time tearing down the old build-
ing and constructing the new one over the old. Founda-
tions for new units were built and old ones dismantled,
requiring planning weeks in advance. The remodeling
was carried on with but one complete shutdown, and that
for only about \'< minutes, which reflects great credit
upon the engineer in charge. The work cost not far from
$2,000,000.
v
When the soot from the tubes of a boiler is blown down,
most of it collects in the dust-settling chamber, from
which it is occasionally removed through the clean-out
doors. This operation necessarily involves labor and time
out of service for the boiler. The illustration shows the
application of a conveyor to a boiler setting for remov-
ing the soot each time the tubes are cleaned. It is op-
erated by steam pressure and is installed in a pipe line
that has connections to the combustion chamber of the
Steam-Operated Soot Contetob
various boilers, as at C. Each connection is furnished
with a slide gate, as at 0. to cut in or out any particular
boiler. Only the slide gate to the boiler being cleaned
is open. Steam is then admitted to the conveyor, creating
a high vacuum, and floating particles of soot are drawn
into the system.
Sometimes the amount of soot to be handled is consider-
able, and as the steam consumption of the conveyor is
the same under all conditions, after leaving the conveyor
it makes a mixture not readily discharged, and for this
reason a special elbow E is used. The boss is tapped to
take a centrifugal spray nozzle, which injects water to
wash the soot down the discharge pipes.
As the water is under pressure and as the nozzle is con-
nected to the discharge in the direction of the flow, it not
only helps to wash out the soot, but the water issuing from
the centrifugal nozzles gives added velocity sufficient to
overcome any reasonable counter pressure.
This soot conveyor i- manufactured by the Schiitte &
Koerting Co.. Thompson and Twelfth St.. Philadelphia.
Fenn.
S
Painting Itoiler Drums — In a plant equipped with B. & W.
boilers developing MOO hp., the interiors of the drums were
scalded, painted both above and below the water line with
silica-graphite paint, and allowed 4S hr. to thoroughly dry.
This treatment was repeated every ten months. Pitting'
stopped, and where it had previously taken sfcic men seven
days to clean the drums of one boiler, two men now clean
them in a day. This experience is quoted from a letter of
the chief engineer of the New York Life Insurance Co., in the
April issue of "Graphite."
June 20, 1915
P 0 \Y E B
8?7
Tlhe S©\utft]h wg\rI<l°Harif is Dnesel EinijpjfiinK
SYNOPSIS — .1 two-stroke-cycle engine with no
scavenging or starting valves in (he head, employ-
ing a stepped piston for both starting and scaveng-
ing and possessing unusual means of fuel control.
The impetus given the heavy-oil-engine industry in this
country by the expiration of the original Diesel patents in
1912 has been marked particularly by the number of
steam-engine builders who have entered this field. Some,
choosing to follow foreign practice, are building under li-
cense from foreign firms with modifications to suit Local
conditions; others have developed what may be termed
distinctly American designs. Among the latter may be
mentioned the Southwark-Harris Diesel engine, buill
by the Southwark Foundry & Machine Co., of Philadel-
phia, from the designs of Leonard T>. Harris.
This is a two-stroke-cycle type intended primarily for
marine service, but also adapted to stationary work, the
engine being somewhat simpler for the latter service, as
no reversing is required. Because of the ingenious, ye!
simple and flexible, control for maneuvering, the marine
type will be described.
Unlike most two-stroke-cycle Diesel engines, there are
no starting nor scavenging valves in the head, the only
opening being for the fuel atomizers, of which there is
one to each cylinder in both marine and stationary types.
There are two atomizer-actuating levers in the marine
type, one for ahead and the other for astern ; in the sta-
tionary type there is, of course, only one atomizer-actuat-
ing lever. This arrangement makes possible a very sim-
ple cylinder-head casting.
The pistons, as shown in Fig. 3, are stepped, the Lower
part serving as a scavenging pump besides acting as a
guide in the place of a crosshead. The cylinders are in
pairs and each scavenging piston serves the adjacent cylin-
der of thai pair through the passage .1. valve !'._.. mani-
fold .1/ and port D. This will be understood when it is
Fig. '.'. End \'h \\ Snow [ng Pumps
Fig. 1. 240-Hp. Southwabk-Harbis Diesei Engine
POWER
Vol. 41, No. 26
remembered that the cranks of a pair are set at 180 deg.
Therefore, when the scavenging piston of cylinder No. 1
is traveling upward, compressing the air in the scavenging
cylinder, ports and manifold, the pistons of No. 2 are
traveling downward, and when No. 2 working piston
has uncovered its port 1>. the scavenging air, under a pres-
sure of about ~. lb., will rush in and force the spent prod-
ucts of combustion out through the exhaust ports E. The
air-delivery valve of cylinder No. 2 prevents the scaveng-
ing air of No. 1 from being forced into the scavenging
Fig. 3. Sectional Elevation
Pi is the main piston; P2. the scavenging and air-starting
piston; V,. scavenging-air inlet valve; A. scavenging-air out-
let passage and starting-air inlet passage; Vs, scavenging-air
delivery valve; M, maaifold; D, scavenging-air inlet ports; V3.
the air-operated intercepting valve ;0. outlet for starting air;
S, silencer; F, vents; B, injection-air storage bottle: C, cam-
shaft: R, atomizer-actuating rockers; K, push rods: L, atom-
izer levers; X, atomizer spindle; E, exhaust ports; I, injection
air from compressor: B, bypass to starting bottles; Id, bell
crank.
cylinder of No. 2 while its pistons are on the down
stroke.
An unusual feature of this stepped piston is its use
1 1 ir starting the engine — a most important factor in
marine work, as it avoids admitting cold starting air to
the highly heated working cylinders and pistons when re-
versing and maneuvering. Moreover, as the area of the
stepped piston is greater than that of the working piston.
starting air of relatively low pressure, 175 lb., can be cm-
ployed. Since the starting i- independent of the working
cylinders, the fuel can be admitted to the latter while
the starting air is still on. This will be found advan-
tageous when starting under load, as the starting air can
thus be used to help out until the momentum has been
built up.
01' interest in this connection are the diagrams of Fig.
-1. No. 1 is from the scavenging cylinder when starting
;.'a" f/RST Outward stroke
•^."SECOND AND CONSECUTIVE OUTIIARD STROKE
' ALL RETURN STROKES
PIA6RAM N0.2
Fig.
DIAGRAM NO J
\|ih \lo|; DIAGRAMS r'HOM WORKING AMI
St ihting Cylinders
with air. while No. :! was taken simultaneously in the
working cylinder. Line a, diagram No. 1, represent- the
first outward stroke, b the return stroke, and c the succes-
sive outward strokes until the starting air is shut off. It
will lie noted that after the first stroke, a pressure of only
30 Ih. is required, owing to the power given back in
the working cylinder by the expansion of the compressed
Showing Fuel Control
working
air within it. Diagram No. 2 shows the rn
of the scavenging piston.
starting and I'uel-injeet ion air is Furnished by a two-
stage compressor driven off the main shaft and having a
control valve on the suction. The compressor delivers >he
high-pressure ait- for fuel injection directly to a steel air
bottle mounted at the hack of the engine frame. The
June 29, 1915
POWE K
879
starting air is supplied to the starting bottles through a
reducing valve.
There is a separate fuel pump for each cylinder, makirj
four in all in the engine shown. These are mounted al
the end of the engine (see Fig. 2) and the stroke is varii 'I
by the governor.
A better idea of the operation of the fuel pumps will be
gained by reference to Fig. 5. First, however, it will be
necessary to revert to Fig. 1, which shows the pump shaft
Tx driven from the main crankshaft through the ver-
tical shaft T and worm irears. At the end of 7', is
mounted a cam U, Fig. 5. which acts laterally upon the
bell-crank levers W; these in turn work the pumps through
the arms \\\, working in yokes on the pump stems. The
fulcrum pins of the bell cranks are carried on laterally
sliding plates V, the movement of which is effected
From Fuel ' Supply Tank
Fuel Pump
Fig. fi. Partial Side Elevation, Showing Further
the Control Features
through two worm spindles, each carrying a pair of right-
and-left-hand worms meshing with sectors X. The upper
worm spindle extends to the right and connects through
gearing with the governor shaft, while the lower worm
spindle extends to the left carrying the handwheel YL
and connecting through links and a rack (see Fig. 6)
with the main control handle Y.
When the pointer of the main control handle is in the
central, or "stop,'" position (see Fig. 1) the bell-crank
lexers II" (Fig. 5) are separated so as not to be actuated
by the cam U. Through the arrangement of links shown
in Fig. 6, this position of the bell cranks is held ordinar-
ily through the starting period. When the control handle
is turned pasl the first notch to the running position, the
lower worm spindle is rotated an. I, bj mean- of the sectors
and slides, brings the hell-crank Levers closer together, so
that they are actuated hy the cam U, and the fuel pumps
arc sel in operation. Th< governor, uovi acting through
the upper worm spindle, is able to control the position of
the bell i ranks and vary the stroke of the pump- to suit
the load. The -mall ha mlu heel >', permits manual con-
trol of the fuel without altering the position of the main
control wheel )'. By this mean- the engineer i- enabled
to control the speed of the engine at will, and the gov-
ernor will maintain control at this -peed. This feature is
ally useful in marine work when running through a
heavy head sea u ith the engine racing.
In addition to the fuel control through varying the
stroke of the pumps, the lift of the fuel atomizers may be
altered at will from the control wheel while the engine is
running. Referring to Fig. 3, thi lower ends of the atom-
izer push-rod- may be swung outward through the arc
on the upper side of the rockers, which in turn are actu-
ated by the cams on the main camshaft. It will be seen
that when the push-rods are at the extreme right the rock-
ers can hi' actuated without imparting any motion to the
atomizer spindles. When they arc moved to the extreme
left the atomizers will have their greatest travel. In-
termediate positions of the push-rods on the rockers will
correspond with definite openings of tin.' atomizers. These
push-rods are shifted by means of the hell cranks shown,
which in turn are operated through vertical rods connected
with the horizontal bar Z (Figs. 1 and 6), also connected
with the control handle. The operation is obvious.
A four-cylinder, 240-i.hp. Southwark-Harris engine has
just been installed in the yacht "Southwark," owned by
C. P. Vauclain, of Philadelphia. The "Southwark" is
98 ft. overall, 16-ft. beam and ? -ft. draft, and on her
first trial trip made a -[ d of about 10 miles j)(.r hour
against the tide and a head wind, with the engine turning
up at 225 r.p.m. Extensive test- are now being made
and the results will he available at an early date.
The principal dimensions, horsepower, weight, etc.,
of the sizes listed are given in the following table:
particulars of stationary type
Ap-
prox-
imate
Weight
I.Hp. Cylin- With- Weight
No. of per del Dia- out Fly- per Floor Length
Cylin- Cylin- meter. Stroke, wheel, I Hp , Space, Overall,
I.Hp. ders der In. In. R.p.m. Lb. Lb. Sq.Ft. Ft. In.
120 2 60 9 13 300 14.000 117 21 6 6 9
240 4 60 9 13 300 25.000 104 34 10 2
360 6 60 9 13 300 35,000 97 45 13 7
225 2 112 5 12 21 200 27.000 120 51 9 8
450 4 112.5 12 21 200 47. em let 80 15 4
675 6 112.2 12 21 200 66,000 102 110 21
400 2 200 16 2S 150 116 14 6
800 4 200 16 28 150 180 22 6
1200 6 200 16 28 150 244 30 6
MARINE TYPE
240 4 60
360 0 60
480 8 60
450 4 112 "'
675 6 112 5
900 8 112 5
800 4 200
1200 6 200
1600 S 20U
16
13 300 25,000 104 34 10 2
13 300 35,000 97 45 13 7
13 30O 14, i •<) 5 56 5 17
21 200 (7,000 let 80 15 4
21 200 66.000 102 110 21
21 200 85,000 94 5 140 26 8
28 150 180 22 6
214 30 6
28 150 308 38 6
Increased the Capacity of the IMant — B. M. Babeock in-
forms us that in his letter under .he foregoing caption. May
18 issue, the beginning of last paragraph on page 685 should
read: "The grate surface was extended from 6 ft. in length
to S ft., giving 56 instead ,f 42 sq.ft. of grate surface," in-
stead of, "the grate surface was extended from 42 in. in
length to 56 in."
sso
P 0 \Y E E
Vol. 41, No. 26
TfiESHEinig
Enftifif^fli^al
■»Y E. .M. IVENS
SYNOPSIS— Several letters on the troubles ex-
perienced in priming centrifugal pumps hare
appeared recently in Power. Interested, and
drawing on his wealth of experience in this prac-
tice. Mr. Iri us presents the following, which shows
several ways of overcoming priming I roubles. It
is a timely, practical and interesting article.
The several letters thai have appeared in Power on'
the subject of priming centrifugal pumps indicate that
much interest centers in thai topic.
It is more or less well known thai before a centrifu-
gal pump of the suction type can pick up its water, the
air contained in the space between the top of the im-
peller blade or blades and the surface of the water in
the suction basin must be expelled. With the removal
of this air there occurs, inside and outside of the pump
and piping, a difference of hydrostatic pressure which
causes the water to rise in the suction pipe and submerge
the rotating parts, and immediately, discharge of water
begins. The heighi to which water may be so lifted
obviously depends upon the barometric conditions at the
time. At sea level the theoretical lift is equivalent to
14. T lb. of pressure (approximately 34 ft.), but owing
to the impracticability of obtaining and maintaining a
perfect vacuum, it is impossible to operate a pump having
so high a lift. Pump manufacturers seem to have agreed
that 25 ft. (dynamic) is the practical limit and advise
that less than this be employed if possible.
There are but two principles that may be followed
in priming a centrifugal pump and its piping. One is
to actually withdraw the air. using vacuum-forming ap-
Fig.
1. Steam Ejector
for Priming
Pump
Foot Yalve
Fig. •'. Displacing Air
Pilling Pump with
Water
paratus of some kind, and the other is to displace the
air with the liquid to be pumped. Fig. 1 illustrates
an elementary installation wherein the former method
of priming is employed, and Fig. 2, the latter.
In Fig. 1 the air i- exhausted by means of the well-
known steam ejector placed on top of the pump casing.
As shown, the system is closed to the atmosphere by
means of the flap valve placed at the end of the dis-
'"Power," Mar. 2, p. 294; Apr. 6, p. 4S1; Apr. 20, p. 550; May
4, p. 615; June S, p. 778
charge pipe. Plainly, this method can be employed
only when steam is available, ami even then it is ob-
jectionable in that the Hap valve is with difficulty made
air-tight. The method is exceptionally tedious and ex-
pensive when relatively high lifts and long suction and
discharge pipes arc necessary.
In Fig. '.' water is admitted from some outside source,
usually an overhead tank provided For the purpose,
through the funnel shown and i.-- held by means of the
foot-valve attached to the lower end of the suction
■Ejerlcr
Fig. 3. r!\ pical Location of Pump for
Drainage or Irrigation Systems
pipe. An air vent is provided at the top of the volute
to prevent •'locking." It frequently happens that obstruc-
tions find their way through the strainer and lodge on
the seat, preventing a complete closure of the valve and
making priming temporarily impossible. Expensive
shutdowns often occur and considerable annoyance is ex-
perienced with foot-valves, when water is drawn from
rivers, lakes or other open bodies of water, as is done
in rice irrigation and land reclamation.
Centrifugal-pump installations are seldom as simple
as those just described. More often, long and angular
suction lines are necessary and various other conditions
peculiar to the requirements have to be met, such as
method of drive, angle of suction and discharge nozzles,
stability of water level in the suction basin and the na-
ture of the pumping head.
The writer is fortunate in that he has had the oppor-
tunity to design and install a number of pumping plants
having a wide range of capacities and pumping heads.
With the experience gained it has been found possible
to overcome the typical priming difficulties previously
mentioned and thus preclude the possibility of annoy-
ance due to loss of vacuum, and at the same time meet
the conditions imposed by the nature of the duty. Fol-
lowing are three descriptions of priming methods that
have given satisfaction and may be applied to advantage
in many places. These will be recognized as embody-
ing the principles already given, but somewhat modified
to meet the requirements of each installation.
Fig. 3 illustrates an installation of a low-lift, large-
capacity pump such as used in Irainage projects. As
may be noted, both suction and discharge ends are water-
sealed and consequently the use of the troublesome
foot and flap valves is dispensed with. A steam ejector
is fitted to the top of the pump casing for priming.
In the event that steam is not available, a vacuum pump,
independently operated, may be substituted. This meth-
od of installation possesses other advantages not perti-
nent here.
June 29, 1915
P O W E i;
881
Fit;. I shows a row of motor-driven turbine pumps the contained water out of the discharge, and a surging
installed in the water-works plant of a small Louisiana results. Tin- relieves tin1 pressure above the small
town. The four larger pumps have each a capacity of check valve, it is opened by the air pressure beneath
850 gal. of water per min. againsi 100 Hi. pressure and air rushes in from the pocket, breaking the par-
and are reserved for lire purposes only. The smaller tial vacuum created. The column pressure then closes
pump is lor constant service and has a capacity of 100 the check valve, and the air admitted by its raising
Pig. i. Layoi i oi Pumping Plant km; Small Louisiana Town; Note the Suction Lift
gal. per nun. againsi 15-lb. pressure. Current for tin'
motors is supplied by two oil-engine-driven alternators.
The arrangement of valves and piping is such that
any one or all pumps may he placed in service at any-
time. The suction line is s in. diameter. 125 ft. long,
and the Math suction lift is P.' ft.
These pumps are primed by the method of displace-
ment. Located in the suction line and in the manner
shown in Pig. 5, is a surface priming valve designed by
the writer. This valve is a combination check and flap
valve having all parts made readily accessible by suit-
ably located hand holes. Fig. 6 shows the exterior of
tin- valve and Fig. ', a vertical cross-sectional view.
The operation of priming and the action of the valve
are as follows: Water is admitted from the standpipe
Fio.
Application of Valve Shown in Pig.
to the pumps through the bypasses indicated in Pig. 1.
and the air is vented off through pet-cocks provided on
the tops of the pump casings. When water appear- at
the pet-cocks, the system is filled from the discharge
nozzles to the surface valve. Between the valve seat
and the water surface there remains an unfilled space
or air pocket. Before the column can he started this
air must he disposed of, and this is done by the action
of the small check valve shown at .1, Fig. ;, and in the
manner later explained.
The motor is now started, and when the full-load
speed is reached there appears a tendency to force
tin1 high point, which is the discharge nozzle of
the pump. Continued operation of the motor i- accom-
panied by continued making and breaking of vacuum due
to surging, until finally the air pocket disappears. The
large flap is then opened by the rising column and
occupies the recess provided in the valve body. A free
passage is offered to the column, and the only resist-
ance encountered is that caused by part of the weight
of the flap.
A- shown in Fig. '. . cleaning of the valve seat may-
be easily accomplished through the handholes and a thor-
Fig. C. The Ivens Priming Valve
ough examination or renewal of all moving parts made
by removing the large cover plate to which the flap is
attached.
The writer has used tin's valve with gratifying
on medium-lift pumps where it was necessary (owing
to fluctuating suction lift) to attach the valve
to the suction elbow, or V connection, on the pump
882
POWER
Vol. 41, No. 26
and some 20 ft. above the water level. Several rice-
irrigation plants located on the Mississippi River are
using the valve in this way.
A rather interesting system of automatic priming
suggested by the writer is employed by a large sawmill
in Louisiana. A diagrammatic illustration of the in-
Fig. 7. Section of Ivens
Priming V \i.vk
stallation is shown in Fig. 8. The equipment consists
of a 750-gal., two-stage turbine pump, direct-connected
to a 100-hp., 2200-volt, three-phase, 60-cyele, 1740-r.p.m.
motor, and a 6x4^-in. vacuum pump, gear-driven by a
5-hp., 220-volt, three-phase, 60-cycle motor. The plant
is located on the Mississippi River about a mile and a
half from the electric generator which furnishes the cur-
rent for the motors.
The suction of the vacuum pump is connected to a
chamber and thence to the discharge nozzle of the pump,
as shown. The chamber is made of 6-in. pipe and con-
tains a cedar float suspended by a rod attached to
a check valve above. The weight of the float and rod
should lose its column, the vacuum pump starts auto-
matically and the process of priming is repeated.
This installation has no regular attendant, and dif-
ficulty has uever been experienced since first starting.
It is quite true, as Mr. Palmer says (Power, Apr. 6
issue), that considerable trouble has been experienced in
priming centrifugal pumps, but often the operator is to
blame and frequently the fault lies in the method of in-
stalling the equipment. In answer to trouble calls the
writer on two occasions traveled several hundred miles,
to find the pump rotating in the wrong direction. On
a number of other occasions the trouble was caused by
leaky suction pipes or air locking due to the accumu-
lation of air at high points in the suction piping.
One unpleasant experience was caused by the designer's
disregard of frictional loses, and an attempt was being
made to operate several pumps with a suction lift far
in excess of that theoretically possible. In every in-
stance the operator first stated that the pumps were de-
fective and then, after his difficulty had been overcome
for him, it was "priming trouble."
dhatracttefflsftacs ©if M.8idl5&<t5©ia
The Bureau of Standards will have ready for distribution
shortly a paper entitled "Characteristics of Radiation Pyrom-
eters." A careful study of this type of temperature-meas-
uring instrument was considered urgent on account of the
extensive use of radiation pyrometers in the technical in-
dustries. These instruments are widely used in the tem-
perature control of the various processes involved in iron
and steel manufacture, alloy-foundry work, glass, ceramics,
and brick manufacture, smelting, gas works, steam genera-
tion, lamp manufacture, etc.
Many of the instruments examined show different tem-
perature readings for different focusing or sighting distances.
Fig. 8.
Pumping Plant Having Motor-Driven Air Compressor Which Automatically Keeps
Pump Primed
is sufficient to hold the check open under 25-in. vacuum
when the chamber is empty. If, by any chance, water
should enter the chamber, the buoyancy of the float per-
mits the check to close immediately. This prevents water
being drawn into the cylinder of the vacuum pump.
The motor operating the vacuum pump is equipped
with a pressure-control switch, the pressure pipe of which
is connected to the discharge nozzle of the centrifugal
pump. Operation is as follows :
Both motors are started simultaneously and the vac-
uum pump rapidly withdraws the air, priming the sys-
tem. When a pressure of 10 lb. is reached in the water-
discharge piping, the pressure switch actuates and the
vacuum pump is stopped. If, at any time, the pump
Errors thus occasioned may amount to several hundred de-
grees. The effect of dirt upon the lenses and mirrors is of
serious importance. The question as to whether the pyrom-
eter absorbs all the heat radiation falling upon it is dis-
cussed, and the theory of the instrument and the connection of
its behavior with the theoretical radiation laws are given.
The bureau receives a large number of these instruments
for test and standardization from various technical industries
throughout the country. Heretofore, this testing required
about three days for a single instrument, on account of the
difficulty in heating a furnace to an exactly uniform tempera-
ture. A new method has been developed which permits a
satisfactory standardization of a radiation pyrometer within
one hour. Many suggestions are given for minimizing the
errors to which the pyrometer is subject, and it is shown that
this type of instrument, suitably designed, adequately cali-
brated and correctly used, is a trustworthy pyrometer hav-
ing many advantages over other types of temperature-meas-
uring devices, both for scientific and technical use.
June 29, 1915
P 0 W E E
883
nirein
f©2°
By William A. Ili:i-i;i.t
■Minn
SYNOPSIS — An unusually complete, inter
and highly valuable article mi mi important sub-
ject iiiimil which liiili' has been written.
Chemically pure fireclay consists of silica and alumina
and combined water. Pure fireclay is called "kaolinite"
and consists of aboui H> per '-cut. of alumina, 16 per cent.
of silica and 1 I per cent, of combined water. It acquires
in its travels various impurities, such as iron, lime, mag-
nesia, alkalies, soda and potash, together with more or
less organic material.
In this country the most important fireclays are found
in Kentucky. Pennsylvania and Missouri.
Physical and Chemical Properties <>f Fireclays
Flint clays arc more nearly chemically pure than plas-
tic clays, because of the difference in their formation.
The flint clays have practically no plasticity, while the
plastic clays vary from slightly to highly plastic.
The colors of plastic fireclays range between the two
extremes of white and black, with such intermediate colors
as gray, brown and olive. Flint clays do not show a
marked color difference, being either white, gray or mot-
tled black. The color of clay is not always a -ale guide
in its selection for quality, for in some cases it indicates
the amount of contained impurities in both the flint and
the plastic clays.
IilPl/KITIES IX FlUECLAYS
The impurities in fireclays occur in various forms —
the iron, for instance, as pyrites (sulphite of iron), some-
times in large particles widely distributed, and at other
times in small particles uniformly distributed. Again,
the iron occurs as carbonate of iron, usually in large, hard
lumps. The lime occurs as gypsum and as limestone.
When magnesia occurs, it is usually associated with lime
in limestone. The alkalies enter in the form of mica or
feldspar.
The amount of contained impurities in the finished
product, firebrick, is not always a reliable indication of
the temperature at which the brick will soften, as is clearly
shown by the curves representing the result of 44 dif-
ferent tests.
Method of Manufacture
The impossibility, on account of excessive shrinkage and
consequent liability to warpage, of using all raw clays
makes necessary the calcining, or burning, of some of
them, preferably the Hint clay, to obtain a high-grade
product. The amount to be used of this calcined, or
burned, clay is determined by the physical and chemical
qualities the manufacturer i- striving to obtain for the
i baracter of work. As flint clays ami calcined clays have
no plasticity, a bonding material is necessary, this being
supplied by a plastic clay. The amount of the latter used
for bonding varies from 15 to 50 per cent. In some
classes of work, practically all plastic clay is used.
•Paper before the Ohio Society of Mechanical, Electrical
and Steam Engineers.
TWith the Charles Taylor Sons Co., Cincinnati, Ohio.
Firebricks arc used in innumerable way: — in the va-
rious metallurgical furnace-, in the manufacture of lime,
cement and glass, and in the settings of -team boilers.
The last practice, particularly in later year-, ha- de-
manded a higher grade of brick than was satisfactory un-
der the former milder working conditions. The more
general use of mechanical stokers, their greater degree
of perfection and the v thorough knowledge by the
operators of the theory id' combustion, have developed con-
dition- which have made high-grade firebricks much
sought for. The development in the manufacture of fire-
bricks has not kept pace with tin' comparatively more
marvelous increase in the severity of service m boiler
and stoker installations.
Boiler-Fuhn m e Conditions
With the present modern equipment much improved
combustion occurs, much higher temperatures prevail and
higher ratings arc obtained than were possible with the
less intelligently designed and operated installation- and
boiler and stoker equipment of former years. Whereas
some years ago a 50-per cent, overload on a boiler was
about the maximum to be expected, it is now not un-
common to see in i he larger plants stoker-fired installa-
tion- operated at 100 to I .'.o per cent, over their commer-
cial rating.
While not much though! was given to the seleeti
firebrick in previous years for boiler work, and a brick
of mediocre refractoriness would -how reasonable life, the
best todav i- none too good under the present extremely
severe operating condition-. It is not to be inferred that
much progress and improvement have not been made in
the manufacture of fireclay brick, as a superior article is
today being made by most manufacturers, and continued
advancement may be expected.
It would seem from present-day experiences that the
capacity of most stoker-fired boilers is limited only by the
ability of the firebricks to withstand particularly the ex-
treme temperatures generated. As an example of high
temperature- : In some stoker-fired furnaces a quantity of
platinum was melted in a graphite crucible, the melting
point of platinum being 3191 deg. F. This temperature
approachc- closely the melting point of pure fireclay,
which is 3326 deg. F.
Kefractoiuks wrri i limn Melting Points
Efforts have been made to substitute materials with
melting points higher than the commercial fireclay brick.
but because of the inability of these materials to with-
stand certain other condition-, such as sudden heating and
cooling, pressure at high temperatures, the action of cer-
tain gases of combustion, and the chemical action of
certain fused ash. these substitutions have failed to real-
ize tin' theoretical expectations. The other refractories
that have been given a trial in boiler work are silica,
bauxite, chrome and magnesite.
Silica bricks, made from silica rock, or ganister as
it is sometimes called, and bonded with about 2 per cent,
of lime, have the particular objection for use in boiler-
furnace work, especially in arches, of being unable to
POWER
Vol. 41, No. 26
withstand sudden changes of temperature without spall-
ing. The lime used as a bond in silica bricks combines
with the silica and makes a product that is hard and
dense after burning. Although silica bricks are highly
refractory and should stand high temperatures, it would
not be practicable to maintain, in boiler furnaces, con-
ditions that would be favorable to their long life and
general use. In furnace side-walls silica bricks, because
they are an acid material, would be readily attacked by
the usually basic ash, the ash of nearly all coals being
high in ferrous oxide (oxide of iron) which is basic in re-
lation to silica.
Silica bricks would stand the service well with an oil
or gas flame, as far as chemical action is concerned, but
here again the sudden change in temperature following the
sudden turning on or shutting off of the burners would
cause a rapid deterioration through spalling. With coal
the furnace temperature is not so suddenly reduced, as
the fuel bed acts as a reservoir of heat.
A silica brick in comparison with a fireclay brick has
a permanent expansion ; that is to say, upon repeated
heatings its size increases up to a certain point, the rate
of increase varying with the different makes of silica
bricks. For example, upon the first heating it increases,
say, to about 0.04 in., upon the second heating to about
0.03 in., and upon the third to about 0.02 in. — a total of
0.09 in. If, then, it bad reached its limit, further heating
would increase the size only temporarily, the brick re-
ducing to its final size upon being cooled. The tendency
of the firebrick is to become slightly smaller, if anything,
upon repeated heatings.
Springs in Arches Unsuccessful
Silica bricks have been used in the arches of heating
furnaces in metallurgical operations, and the expansion
of the silica arch taken care of by sets of springs placed
on the sides of the furnaces at each end of the arches.
This is a costly and an annoying arrangement, so we are
told, and so far as known is not sufficiently satisfactory
to meet with general adoption.
Chrome and magnesite bricks, used in basic openhearth
furnaces and other places where the temperature and
chemical action is severe, would seem to be ideal for
use in boiler side-walls, but because of their inability to
withstand much pressure at high temperatures and the
heating and cooling effects, these materials are out of the
question.
On bauxite bricks experiments are being made to deter-
mine their value as a refractory in boiler settings. It
has been difficult thus far to make a product of bauxite
which will give uniformly good results, by reason of
the wide variation in the chemical composition and physi-
cal properties of the raw material and the difficulty met
with in attempting to control the crude ore. On account
of the value of bauxite to the aluminum manufacturer
the fields of the best ore are owned by the aluminum in-
dustry, and what is available to the brick manufacturer
is of inferior quality. Also, more than the usual methods
must be employed in reducing the great shrinkage in
bauxite, which requires calcining at high temperatures.
Bauxite brick, too, is likely to spall.
From the discovered deficiencies of these special re-
fractories— namely, silica, magnesite, chrome and baux-
ite— for boiler furnace and arch practice, it would appear
that the manufacturer who is striving to develop an ex-
traordinarily refractory product for this class of service
must confine himself in his experiments to find the proper
combination of fireclays.
Selection and Use of Materials
Much trouble with firebrick settings is due to improper
selection and ignorance in the use of the materials, and
also in many cases to lack of care in constructing and
laying up the work. In arches, particularly where the
service is hard, care should be taken that all bricks in
the same row are of the same thickness and shape, as
it is difficult to secure high-grade brick of the same
thickness and uniformity. This fact is apparently recog-
nized by the United States Government, which makes
liberal allowances for variation in the size of firebrick in
its specifications. In a maximum of 9 in. in length it
allows a minimum of 8% in., although this wide varia-
tion should not occur in any one lot of brick and is a
variation that the manufacturer would not be proud of.
A conscientious mason will carefully select his brick,
culling out those of irregular shape, and will try the
selected brick dry over the arch-form with a straight-edge.
Then he dips them in a creamy solution of fireclay and
rubs them in place. Bricks of uneven thickness should
be cut and rubbed. If this care is not exercised large
fireclay joints will be required and the life of the arch
seriously shortened.
Wedges should be used as often as is necessary to keep
the bottoms of the bricks in even contact with the arch
form, and the key-brick course should make a true fit
from top to bottom. The key brick should be driven from
1 to about 11/2 inches, depending upon the hardness
of the brick and the width of the arch.
Fireclay Mortar and its Relation to the Life of
Firebrick
All firebrick, whether fireclay or special refractories,
should be laid in mortar of nearly the same composition
as the brick itself to prevent a fluxing action, such as
would be caused if, for instance, siliceous mortar were
used with magnesite brick. In the case of fireclay bricks,
a good grade of fireclay should be used, the refractoriness
of which is practically equal to that of the bricks them-
selves. This precaution is sometimes not taken, with
the result that the fireclay begins to melt at a lower tem-
perature than the bricks will stand, and in melting dis-
solves the bricks adjoining it, much the same as a piece
of copper is melted at a temperature lower than its natural
melting point when placed in a pot of melted babbitt
metal. Inferior clay used in an arch may therefore result
in the softening of the bricks and the collapsing of the
arch.
Foreign materials, such as salt and lime, added to fire-
clay to make it soften and fuse the brick together is, in
the manufacturer's opinion, a practice not to be recom-
mended, as both of these materials are active fluxes and
readily attack the bricks, especially at high temperatures.
In mixing fireclay to be used as a mortar, best results
can be obtained by using a certain amount of fire sand ;
that is, pulverized calcined clay or bricks. This prevents
shrinkage of the raw clay and the crumbling out of the
joints. Regarding the benefits derived from boiling fire-
clay, there is a difference of opinion. Some boil the clay,
feeling that it takes out the shrinkage, 'although there is
not enough heat in the boiling process to take out any
June 89. 1915
PO W !•: R
885
appreciable shrinkage; bul boiling results in a complete
mixture, making it free from lumps and putting it in
shape tn make a tight job.
Laboratory Tests Compared with Practical Tests
In selecting bricks to be used in furnace practice, the
manufacturer is often asked for an analysis of the brick
he intends to furnish in order that the user may judge as
to its quality. The analysis alone of a brick does not af-
ford the best way to judge its suitability for the work in-
tended, as the analysis merely shows its composition with-
out giving any information as to its physical properties,
which are usually more important than the chemical com-
position. The analysis does not reveal the way in which
the impurities occur — an important item in considering
the temperature to which the bricks may be subjected
without danger of failure. The curves show clearly that
the melting point cannot he judged by the analysis alone.
On these curves showing the fusibility of 44 differeni
firebricks, the per-
I
of the sample. This way of determining the melting
point has the advantage over other methods using pyrome-
ters, inasmuch as these cones take into account the time
element; time should be considered in determining the
softening temperature of any fireclay product, as a brick
which melts at a high temperature, say in one day, can
be melted at a much lower temperature by holding the heat
Eor a longer time.
The melting point is sometimes determined by means
of an optical pyrometer. This is also a good method,
if all tests are carried out in the same length of time, so
as to be comparative.
The temperature at which a piece of firebrick melts in
an electric testing furnace is often higher than this same
brick will stand in a boiler or commercial heating furnace.
as in such furnaces there arc conditions, such as the ac-
tion of the slag and furnace gases, which are not present
in the small electric furnace test. On the other hand.
3 5 7 9
90
80
70
60
50
40
30
20
S>'°
° 0
£l5
o
°- ii
9
7
5
3
I
w
^
^>£v
V-
^
ALUMINA PER CENT.
I 3 5
centage of silica.
alumina and total
fluxes present in
each brick, it will
be n o te d that
brick No. 5 melt-
ed at Cone No.
3iy2, or 3200 deg.
F., and had 12 per
cent, of alumina.
47 per cent, of sil-
ica, the sum of
mixes being 12
per cent. ; brick
No. 21 melted at
Cone 30, or 3046
deg. V.. and had
50 per cent, of
silica, 38 per cent,
of alumina, the
sum of fluxes be-
ing 11 per cent. It
would seem from
the similarity of
these analyses that
these two bricks would melt at
but owing to the difference in the
is more refractory than the other.
To secure a sample for determining in a laboratory
the melting point of a firebrick, the usual method is to
knock a corner, about one inch high, off a brick, the bot-
tom of the test piece so secured forming a triangle, each
side of which measures approximately one-half inch. This
piece, together with three small cones, each having a
different known melting point, is then placed in an elec-
tric furnace for observation as the temperature of the
furnace increases. When the sample piece of firebrick,
in the form of a small pyramid, loses its shape, it is con-
sidered melted, and the highest pyrometric cone which
is melted alongside of the test piece indicates the melting
point of the brick. For example, if three pyrometric cones
were used, each having a different melting point, say
3218, 3254 and 3290 deg. F., and the 3254 deg. cone was
left unaffected, while the 3218 cone was melted at the
time the brick sample started to melt, we would know that
between 3218 and 3351 deg. P. was the melting poinl
Number of Analysis
13 15 17 19 21 £3 25 27 29 31 33 35 37 39 41 43 45
£>'—?>f-X
V^
l*\£
A
^Vv/
A
^Aa
33
32
31 «
30 E
29 z
u
28 g
<u
26 cr>
25 "1
24
3 II 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45
Number of Analysis
Results of Analysis of Forty-Four Firebrick
in the electric
furnace the brick
is surrounded by
a high soaking-in
heat, no chance
being afforded for
radial ion, as is the
case with bricks
in furnace walls
in some types of
furnace arches.
The service due to
heat alone is not
as severe on fire-
bricks placed in
walls exposed to
the atmosphere as
in partition or di-
vision walls be-
tween furnaces,
where the heat i.
acting on both
sides of the wall.
That this is true
IS demonstrated
by the longer life
the same temperature,
lysical structure one
that arches exposed to the air on one side will show over
those subjected to fire on both sides. Although brickwork
will show longer life where there is such cooling actum.
this gain is usually had at the expense of lost heat energy.
United States Government Tests
Another way to determine the softening point
by
means of the government load test. This consists in plac-
ing a brick on end, loaded 50 lb. per sq.in. of cross-sec-
tion, and in having it successfully stand a temperature
of 2400 deg. F. for one hour without showing any defor-
mation, checking, spalling, or contraction greater than
y2 inch in length. In making this test the heat is brought
up so that 2400 deg. F. is reached in four hours, and
this temperature is maintained for another hour. An-
other government test consists of breaking up a brick and
subjecting the pieces to a temperature of :!200 deg. F.,
which it must stand without softening. Under the load
test, if the brick contains many impurities, its fluxing
action will occur at this or a lower temperature ami
the brick * soften, thereb" allowing it to compress un-
POWER
Vol. 41, No. 26
der ili«' total weight of 562 lb. This load tost is bet-
ter than the melting- or softening-point tot, as it shows
more clearly the temperature at which the brick com-
mences to soften, and this is the temperature which the
user of firebrick, especially firebrick for boiler practice,
is interested in. It is also a more comparative test than
the melting-point test, as the time element is always the
same and it is merely a case of measuring the length of
the brick before and after testing to determine the con-
traction; whereas in the melting-point determination the
question always arises at just what point the brick is
considered melted, that is. whether it is melted when
the tip and sharp corners of the pyramid become rounded
or whether it is melted when the piece of brick is seen to
distinctly flow, the difference in temperature between these
two points being considerable, as the viscosity of most
brick is high.
Conductivity of Riuck Important
The conductivity of firebrick is a property seldom men-
tioned in considering brick for boilers; but tests have
shown that a bard-burned, dense brick possesses a higher
conductivity than a soft, open-grain one. The chemical
analysis does not provide information as to the rate at
which a fireclay brick will conduct heat, this property
depending upon physical makeup.
Some Causes of Failure
A not mirequent cause of trouble in arches is spalling,
which is a popping-off of large piece- of the bricks. This
sometimes results from arch bricks becoming frozen or
wet through a leaky boiler tube, header cap. drum seam or
water used in washing out or in turbining the boiler tubes.
With this condition unnoticed or unknown to the opera-
tors, a hot lire is started before the bricks have been
-lowly dried, with the result that some, if not all, of the
bricks crack and pop off. Once this action is started in
any part, the balance of the arch is usually doomed to
early destruction. This is because the adjoining bricks
are exposed on more than one side to the action of hot
gases, more area is receiving heat and more heat i< being
absorbed by these bricks than they have capacity to take
i are of by conduction and by final radiation to the atmos-
phere or a cooler zone of the furnace.
Why Spalling Happens
Spalling, again, may be caused by the natural inabil-
ity of the brick to withstand the high temperatures of
large volumes of slowly moving or confined gases. The
ends id' the brick are absorbing heat faster than they can
conduct it to a comparatively cooler zone, consequently
the clay in the exposed ends becomes vitrified, the elas-
t icity of that portion is lost, and when further heating and
cooling take place the difference in the rate of expansion
and contraction between the two parts of the brick causes
a separation, the vitrified section dropping oil' unless held
temporarily by the compression of the arch.
Spalling is also tin1 result of strains due to inrushes
id' comparatively cold air striking the incandescent bricks
and suddenly contracting them. These cold blasts occur
when fire-doors are held open too long, or when hand-
or stoker-fired grates are improperly operated and large
holes in the fuel bed permit a strong draft to pull the
cooler outside air into the furnace.
A test sometimes resorted to by prospective buyers
to determine the value of a brick for archwork, is one
wherein the sample is placed in the furnace, brought up to
a red heat, and suddenly dropped into a pail of water.
If it does not crack, it is assumed that it will not spall
in service. This is no indication of the ability of a
firebrick to withstand the heating and cooling strains in
an arch, as the conditions are not the same. In heating a
brick in an open fire it expands uniformly in all direc-
tions, and when thus suddenly cooled the contraction
is likewise equal in all directions, whereas a brick in an
arch is exposed to high temperature on one side and to
comparatively cool gases on the other. When the bricks
in an arch are suddenly cooled by a draft of cold air, the
upper ends contract at a different rate from the remain-
ing portion.
It is found that a close-grained, hard-burned brick is
usually more susceptible to this action than a soft, open-
grained, or porous, brick, which is more elastic and bet-
ter able to adjust itself to this expansion and contrac-
tion. The theoretical explanation of this is that in a
close-grained, or fine-ground, hard-burned brick, the mole-
cules are more closely associated and heat is more rapidly
transmitted from one molecule to the other. Open-
grained bricks for this reason act, we might say, more as
insulating material, tending to repel the heat instead of
absorbing it. When making this comparison we have
in mind only such bricks as are made of highly refractory
clays, as no matter how carefully a brick may be con-
structed, if it has not clays of such refractoriness as will
resist the action of the temperatures applied, it will be
useless for the work.
Another trouble with arches is caused by the improper
setting of the skewbacks, through a failure to pack them
tight against the buckstays at the sides of the furnace.
or using with them, as filling-out pieces, firebrick which
come up tight to the buckstays and are set snugly to-
gether without fireclay joints.
Allowance foe Expansion and Contraction
Arches should be designed and constructed so that
they will meet no interference when expanding or con-
tracting. They should not be tied into front-wall brick-
work or carry the weight of any other part of the setting.
One also .should strive to secure as nearly as possible the
same conditions both under and above the arch for its en-
tire length. In other words, if an arch within a boiler set
ting is made a continuation of the dutch-oven arch out
side the setting, there is liability of the arch breaking.
The extension furnace arch has its upper side exposed
to the cooler atmosphere, while the inner arch is in con-
tact with the hot gases id' combustion on both sides. The
rate of expansion of these two differently located parts id'
the arch, it is evident, will be different.
Spring of Arch
Arches with too much spring frequently buckle and
break their backs when they rise by expansion. A rise
or spring of 2 in. to the foot of furnace width is the com-
monly adopted practice. This gives a reasonable spring to
the flatter arch and acts as a resistance to expansion, keep-
ing the arch tight.
Rounding off the last, or end. bricks in an arch fre-
quently lessens or remedies the trouble caused by the spall-
ling off id' these ends, and due to the gases making a short,
right-angled turn and throwing an intense heat into the
June 29, 1915
POWER
887
corner of these bricks, which have two of the faces
posed.
Different Brick foe Different Parts of Furnace
In considering firebricks for different parts of a fur-
nace, it must be borne in mind that the conditions in side
walls are different from those in an arch and that a brick
which often gives excellent service in arch practice docs
not always give correspondingly good results in the side
walls of the same furnace. It is therefore well in some
cases to use two kinds of brick rather than to try to make
one kind do for both places.
Arch practice requires a brick that is not only suffi-
ciently refractory to withstand high temperatures, but
one that will withstand these temperatures under much
compression, that will not spall and that has a minimum
amount of shrinkage and expansion.
In the United States Government tests made on vari-
ous bricks throughout the country, many bricks were
found which would hold up under a temperature test
of 3000 and 3200 deg. F. without softening, but only a
few, we understand, stood the heat test under pressure.
Furnace side walls are not so much affected by spall-
ing as they frequently are through the chemical ac-
tion of the fused ash and distilled gases of some coals.
Generally speaking, where coal is used as fuel, furnace
side walls require a brick less porous and soft than would
be used in an arch, in order to stand abrasion from the
lire tools and the cutting action of the clinkers when
being disturbed or removed.
Arch Blocks
Blocks for arches and side walls are sometimes used
and in many cases give better results than standard 9-in.
brick. They have the advantage of reducing the num-
ber of joints and parts to lay, and the radial arch blocks
turn true to the given circle. These blocks are usually
made on special orders of a certain combination of clays,
are tried for fit, and by some manufacturers machined
down, where necessary, on a carborundum wheel to secure
level sides and to insure a good fit. On account of the
greater mass of contained material, these blocks must be
carefully and slowly dried on a cool floor and painstak-
inglv burned.
The planetary type of gear shown in Figs. 1 and 2
is a recent development of the Turbo-Gear Co., Baltimore,
Md. It is designed to be used as a speed-reducing or
speed-increasing gear and will run either right- or left-
hand. The driving and driven shafts rotate in the si
direction.
The gear consists of a large internal double-helical
gear made of an openhearth steel forging. A double-heli-
cal pinion cut integral with the high-speed shaft is made
of chrome-vanadium. The intermediate double-helical
gears are made of manganese-bronze and are mounted on
hardened and ground forged-steel shafts which are secured
td the cast-steel slow-speed member by means of a taper
fit and Woodruff keys.
The slow-speed member to which is secured the slow-
speed shaft is mounted on two heavy-duty ball bearings,
one on each side of the gears, and supported directly by
the heavy housing. The slow-speed member, the shaft
carrying the intermediate gears and the high-speed shaft
and pinion are independent of each other for support and
each is supported directlj by the housing.
The housing is made of casl iron, horizontally split
to afford accessibility to all internal parts. It is heavy
and well ribbed to provide a rigid support for the gear
members in order to secure quiet operation. Caps pro-
tect the high- and low-speed bearings from dust.
The high-speed -baft has a central passage through
which the oil is pumped, and a continuous stream is
-prayed on the gears through radial passages in the
Fig. 1. Turbo-Reduction Gear
— »j
Km. 2. Section through the Turbo-Reduction
Gear
pinion. The high-speed bearings, besides having forced-
teed Lubrication, arc provided with oil rings and an oil
reservoir for emergency use. The superfluous oil from
the high-speed bearings is collected by a centrifugal oil
ring and forced through the hollow shafts carrying the in-
termediate gears, Hushing their bearings. The oil. after
lubricating the bearings and gears, is immediately drained
to the main oil reservoir in the base of the housing; here
it is strained, cooled, returned to the pump and used over
again.
888
PO W E 1!
Vol. 11, No. 2(>
On Apr. 20, 1915, the St. Louis & San Francisco
R.R. began removing the smoke-stack at its North
Springfield shops. This stack was 1 Hi ft. high, S ft.
in diameter and composed of sheets ^ to ^ in. thick.
steam pressures and the use of superheated steam, at
the same time giving a higher efficiency under ordinary
low-pressure steam conditions.
Au automatic cutoff control gives high steam economj
under conditions of varying load or varying steam
pressures. This control is regulated by a centrifugal
Removing a Steel Stack with the Oxvacetylexe Torch
Seventeen rings were removed, the height of each being
50 in.
Oxyacetylene was used in cutting down this stack, says
E. \Y. Allen in the American Machinist, at a cost of
$283.?:) for gas and labor. On account of the condition
of the stack, it would have cost approximately $500,
if any other method had been employed and would have
taken 17% days to remove it. By using oxyacetylene it
was removed with a saving of about $216, and the work
completed in -i\ days.
Eimg|eirs©EE°!R,aiir&dl Hiifflh EfficneiniC^
The coristanl demand for higher efficiency and greater
economy and the increasing tendency towards the use
of higher steam pressures have led to the development
by the Ingersoll-Rand Co.. 11 Broadway, New York City,
ol an improved -mail steam-driven, high-speed air com-
pressor.
The machine is designed along the same lines as the
company's former small steam-driven type, bid embodies
many improvements which give it a higher efficiency in
the air end and a considerably lower steam consumption
iii the steam end. These improvements are as follows:
The adoption of the Ingersoll-Togler air valves, which
allow of high speeds, give high compression efficiency, are
almost silent in operation and are independent of any
operating mechanism.
Balanced-piston steam valves, designed alter the most
advanced European practice, permit of high speeds, high
flywheel governor which acts to shorten or lengthen the
stroke of the piston valve, thus changing the cutoff.
All wearing parts are copiously and automatically oiled
by means of automatic splash lubrication, and inclosed
Steam-Dkiven All; Compressor
make f(
leanliness
construction and removable <
with great accessibility.
The machine i- designed and constructed with special
attention to rigidity without excess weight. The bearing
surfaces are large and special provision has been made
Tor ready adjustment ><( all parts, without loss of
time.
The automatic cutoff control is supplemented by an
air unloader, which assures economy while possessing
a high degree of automat ism which is essential in a small
compressor designed lor severe duty, and generally sub-
ject to considerable neglect.
June 29, 1915 P 0 W E R
FVtmJfts of thus ILocosiaotlav© IB©iE©iP
The most cheering pail of the paper on "Fruits <>f
the Locomotive Boiler hispei -t i< >n Law." read lie tore the
Western Railway Chili by Frank McManamy and pub-
lished elsewhere in this issue, is that the number of
serious locomotive boiler accidents is decreasing, not
because of the application of appurtenances simple oj
automatic, not because money is being invested in this
and that contrivance, but just because the law promotes
more thorough maintenance and greater carefulness of
operation. Yes, of course, this could have been done
without the law. But it was not, And therein lies
the chief force of any good boiler-inspection law.
"No railroad man," says Mr. McManamy, "with
knowledge of conditions and practices prior to the passage
of the law can question the fact that, generally speaking,
inspections are now more carefully and more regularly,
and repairs more promptly, made, and the question of
repairs is less apt to be determined by the number of
loads in the yard awaiting movement."
There is just as much morality and altruism in
railroad men as in any other class. And it is with due
appreciation of these virtues that we remark that the
improved conditions mentioned by Mr. McManamy exist
because the potential offenders know that they are being
watched more closely now than before the passage of
the law. The same is true in stationary practice.
Most of us are good anyway, but if we know we are
being watched we are better. We admit this to ourselves,
but seldom to others.
This looseness or carelessness often manifests itself
in acts or conditions thai cannot be said to be due to
exigencies of the service, or to sacrifice of safety for con
venience, or to the erroneous idea of saving monej bj
putting off the day of spending it in needed repairs to
parts in dangerous condition. This kind of laxity is
detestable, because it is void of reason and inexcusable.
• For example, during the last fiscal year the department
records show that eighteen persons were injured by studs
blowing out of fireboxes 01 wrapper sheets. Doubtless
most of them gave long and ample warning, by leaking,
that they needed renewing. It is also true that, usually,
they can be renewed more cheaply before blowing out
than after. But do, the} arc tinkered with. The\
are calked or neglected altogether until finally they blow
out.
For this sort of psychological phenomenon no boiler
law can of itself do any good. The attitude of mind that
allows this condition to continue can be cured only by
education, whether it comes by persuasion and reason or
is got by the offender-victim being nearly killed before
he learns his lesson.
That some opponents of boiler-inspection laws still
offer the argument that all boiler explosions are crown
sheet failures, therefore man failure- and not preventable
through law, is evide t from one of Mr. MeMananiy's
statements. Of course such a contention is mere froth.
In the locomotive-inspection service during 1914, as
compared wilh 1912, crown-sheet failures decreased
forty-eight per cent, and the number killed, sixty-four
pi r cent.
From Mr. MeMananiy's paper ii appears that on some
locomotives the location, relative to the highest point
of the crown-sheet, of (he hoitom liftings for gage-glasses
constitutes a menace.
It is difficult enough, owing to grades, curves and stops,
to keep. the crown-sheets of locomotives covered at all
times, even where the glasses are conveniently and
properly located, and to put them elsewhere is nothing
short of criminal. On a busy division particularly, an
engineer has so much to watch along the right-of-way
that simply a glance from his seat should enable him to
see the water level. But we learn that on some types of
locomotives the engineer must leave In- seat to see the
water level, and on others must step hack out of reach
of the throttle, brake valve and reverse lever to try the
gage-cocks. The strongest condemnation of these con-
ilil ions is loo mild.
Happily, the aim of all is to reduce the hazards and
attain better conditions generally. And the law is re-
sponsible for the movement.
In our issue of June S, on page 785, we printed a
idler from E. B. Strong, president of the Strong,
Carlisle & Hammond Company, calling attention to the
importance of seeing that new steam lines are clear id'
grease, white lead, iron tilings and dirt id' all kinds
before they are put in use. so that foreign matter may be
I ept out of separators, reducing valves, .-team traps, and
all other de\ ices.
The necessity of doing this seems so self-evident that
it hardly would appear that comment on the subject was
(ailed for, but inasmuch as a man of Mr. Strong's ex-
perience has found thai carelessness in this particular
is common, we feel the importance of calling attention
to it on this page, in an effort to do as Mr. Strong
suggested — start a campaign of education along the lines
of showing the importance of clearing steam lines before
they are put in use.
There is a saying somewhat to this effect, although
not in exactly the same words, that •'the man who would
not put dirt in the works of his watch would nevertheless
put things into bis stomach which arc equally bad for
that organ." The author of this remark might have
gone further and added that the man who takes great
pains to keep the brasswork on his engine polished, and
other things about his plant neat, will sometimes do just
such careless things as to connect up a steam line with
lengths of pipe that have lain where thej could ac-
cumulate dirt and rust in the interior, or that possibly
are fouled with 'hip- from threading, witl blow-
ing these lines out with steam befor ng to
890
POWER
Vol. 41, Xo. 26
them anything so susceptible to injur}- from foreign parti-
cles as a separator or a reducing valve or even a steam
trap.
Surely this is one of the big little tilings about a
steam plant that the engineer in charge should give
bis personal attention to. whether the work is being
done by outside help or by his own force, so that no pipe
connections may be made in such a way that there is
any risk of foreign matter getting into the system.
LfSceims© (Cosmnnmifttt®©® Tal&©
BJoftnc©
When the framers of the present Xew Jersey license
law had completed their task, with the assistance of an
attorney, no one of the many who looked over the bill
could find fault with it. When the license bureau began
its work, however, a defect showed itself.
The law states that "provisions of this act shall not be
construed to include or apply to" marine engineers, i
neers in plants under the jurisdiction of the United States,
nor locomotive engineers. They were and are willing to
be examined and pay for licenses, but the attorney-general
says that they cannot lawfully be granted licenses. They
are now aggrieved and protest vigorously.
The import is far more serious than appears on the sur-
face. The wording of the law is such that an engineer
holding a license to run a dinky tugboat may operate the
largest and most complex stationary plant in the state
and be immune from any action that the license bureau
may see fit to take.
This is important, and license committees should take
a lesson from Xew Jersey's error.
Obtaining the investment and operating advantages
possible with high boiler ratings has confronted the
engineer with high-temperature problems that, while
serious, are being admirably met. Procuring the most
suitable firebrick for given conditions is only one of these
problems, but it is so far the one furthest from a satis-
factory solution.
The engineer may, after tests and experience, select
the most suitable of available bricks, but it is the
manufacturer's function to produce bricks that will meet
the extremely high temperatures associated with modern
boiler-room practice. When a boiler is operating at from
two hundred to three hundred and fifty per cent, of
rating, the furnace is filled with a dazzling white gas
and the temperature approaches three thousand degrees
Fahrenheit. This is within a few hundred degrees of
the temperature at which pure fireclay will melt.
With the widely fluctuating furnace temperature, the
bricks are subjected to severe expansion and contraction.
Arches frequently have extremely high temperatures on
one side and comparatively cool gases on the other; side
walls are affected by the chemical action of the fusing
ash; and poor clay, when between joints, soon drops
out, exposing the brick to a soaking-in heat. And so it
goes, the sources of trouble being numerous, and greatly
increased if the masonwork is not of the best.
Notwithstanding the seriousness of the firebrick prob-
lem, it is a fact that little really useful information
relative to it has been published. The article elsewhere
in this issue is one of the best general ones that has come
to our attention. It is replete with information that
any engineer can use, whether he operates at a high or
a low rating, or a large or a small boiler plant.
But it is not enough. There are many plants where
the firebrick problem has been, and is now being, in-
vestigated and the need for immediate dissemination of
results is urgent. Those who have investigated ex-
tensively and discovered and compiled truly useful and
applicable information should give others the benefit by
making it available for publication.
©o©3 tth® A2ia©3radl©dl Mas
We have just received a communication which brands
as discriminative the .Massachusetts license law as
amended. As told editorially in our issue of June fif-
teenth, the law was amended to allow plants operating
the major part of the time by water to be in charge of an
engineer holding a special license. The writer of the
letter wishes to know why plants having waterwheels
should be so favored, while the same liberties are not ex-
tended to plants run by electric motors, driven by
purchased current the major part of the time.
If the danger is no greater in one case than in the
other, then there is no reason why the plant operated
most of the time by electric motors, but only part of the
time by its own high-pressure-steam-driven machinery,
should not be allowed to be operated by a man holding a
special license. Where none of the engines and boilers
in such a plant is not of greater capacity than one-hundred
and fifty horsepower, a special license will cover the plant.
But if any of the engines or boilers are of greater capacity
a first-class engineer must be in charge, though the plant
is driven most of the time by purchased current.
Technically, it is easy to show that the amended law
is discriminative in favor of water power, but plants op-
erating on purchased current most of the time and run-
ning their own engines and boilers some of the time are
lew. The condition rarely exists, because when an in-
dustrial plant uses purchased current it uses it exclusively
or only on overloads, which are carried by new equip-
ment just as soon as the latter can be advantageously in-
stalled. Of course, breakdown service is available in some
plants, but. as its name implies, it is only for emergencies.
It is not at all likely that serious trouble will follow the
discovery of this technical discrimination, because there
are few, if any. such plants in existence to be discrim-
inated against. In plants such as our correspondent has
in mind, the owner will find it good business to keep a
thoroughly competent man in charge, regardless of what
the law allows him to do. The law will allow you to
take your watch to a blacksmith for repair, or get your
hair cut by a gardener who trims the hedge, but you would
not take advantage of either opportunity.
m
Efforts are being made before the Xew York Constitu-
tional Convention to have the Public Service Commis-
sions made constitutional bodies surrounded with all the ■
safeguards afforded the courts. There are few depart-
ments in the state government wherein personal integrity
and moral courage count for more, and any step that will
help to render the public service commissions free from
personal or political influence is commendable.
June 29, 1915
POW E I!
891
,■!:■ i
Cojnresjpoinidleinice
To Stnaooftlhi a Valve §©a(t
A 1 -in. globe valve, although nearly new, gave trouble
by leaking. It was
in a ratber cl a r k
corner, so for a long
time i t w as no I
n o t i c e (1 that the
valve seat bad be-
come roughened
from some c a u s e.
When discovered, the
first thought w a s
that a new valve
would be necessary,
as we had no tools
at hand for dressing
the seat, but a piece
of flat file s h o r t
enough to be turned
around while lying
flat on the seal did
the work. A con-
trivance for rotating
the file was made
from the shank of
an old wood hit, flat-
tened and shaped as
shown in the illus-
tration. With this
tool in a common bit
braee, the valve seat was quickly made as smooth as when
new.
G. E. Milks.
Denver, Colo.
Valve Seat Smoothing Tool
? Eagn usees'
edl ami Pec^alllsiff'
About the middle of last month a turbine connected
to a 250-kw. generator in a cold-storage plant in New
York City wrecked itself and instantly killed the
engineer in charge. The cause of the accident is not
definitely known nor the circumstances leading up to
it, as the engineer was alone in the room at the time.
From indications, however, it is believed that the
bearing-cap on the end of the shaft next to the rotor bad
become loosened and that the engineer was tightening
or adjusting if at the time. The shaft was 1% in.
diameter and ran at 9000 r.p.m. It, was impossible to
tell from the wreckage whether it was the shaft or the
bearing which gave way first, as both were badly broken
up.
The duty of this set was particularly severe, as there
was no duplicate machine and it was kept in constant
operation, except a stop of half an hour on Sundays, so
that most of the adjustments which were made had to
be done while the machine was in service. This accident
demonstrates anew the extreme risk to man and ma-
chinery of making even minor adjustments not intended
to be made while the machine is in motion, and especially
so when operated at such high speed.
William South akd.
N'eu Yuik City.
Hinig§=> suae
In the May I issue under the caption, "Inn rior
Wiring Cor Lighting and Power Service," Mr. Cook makes
some statements that are not quite up to the latest
practice. First, in reference to the voltage employed by
alternating-current motors, he states that in some eases
for very large motors 2200 volts is used. Now 2200 volts
is commonly used and 6600 md 7500 volts are occasion-
ally used for large motors. Probably (he most notable
GGOO-volt induction-motor installation is the three G000-
hp. machine group in the rail-mill department of the steel
works of the IT. S. Steel Corporation, at Gary, Ind. A
description of these motors was published in Power in
the issue of Apr. .">, 11)10. Ill a recent steel-mill install-
al 6600-volt induction motors have been used through-
out ; the machines ranging in size from 350 to 3000 hp.
and aggregating approximately 12,000 hp.
Another important installation is the 300-hp., 7500-volt
induction motors used to drive the exciters in the new
power house of flic United Electric Light & Power Co.,
New York City.
K we include synchronous condensers ami frequency
changers in (his category, it will lie found that the
voltage is even higher, as there are a number of 1 1,000-
and 13,200-volt synchronous motors in operation in this
country; probably the highest-voltage machine of this
type being the I6,500-volt, liOOO-kv.-a. synchronous con-
denser used for power-factor correction by the Southern
California Edison Co., of Los Angeles. What in all
likelihood is the largesi frequency changing set in service
today is that installed to interconnect the Boston Elevated
and Boston Edison systems. This set consists of a
13,200-volt, 25-cycle unit rated at 9000 kv.-a., and a
13,800-volt unit rated at 9000 kv.-a.,
Secondly, with direct-current systems it is possible to
obtain motors that will allow a speed change of 3 to 1.
One of the latest productions id' the electrical industry
is an adjustable-speed reversible direct -current motor for
metal planers and slotters, having a speed range of 250 to
1000 r.p.m. by field control; these machines have been
standardized up to 50 hp. Motors for continuous service,
with a speed range of I to I, have been built in sizes
up to I •.'."> hp., and 225-hp., 500-volt machines with a
speed range of 225 to 675 r.p.m., or 1 to 3. Moreover,
I L5-230-volt machines may he had with a speed ran
1 to G in sizes up to 25 hp. continuous-service rating.
or i"> hp. intermittent-service rating.
Thirdly, Mr. Cook appears to use the terms "ad-
justable speed" and "variable-speed" alternating-currenl
892
P 0 W E E
Vol. 41. No. 2G
motor? synonymously, whereas they mean two different
Tlir variable-speed machine is one in which the
speed is constant tor constant load, but varies with the
load, accelerating with light loads and dropping again
when the load comes on, as in a direct-current motor
with armature control or a phase-wound rotor polyphase
induction motor with rheostatic control. Adjustable-speed
machines are those in which the speed remains ap-
proximately constant at any adjustment, irrespective of
the load. One of the best examples of this type is the
direct-current shunt motor with field control. Until
recent years only direct-current motors were available
for strictly adjustable-speed drives, which is also true
today for small motors where wide ranges of speed are
required. However, during the past eight or ten years
schemes have been developed for adjusting the speed
of alternating-current motors, so that now the adjustable-
speed polyphase induction motor in many cases compares
favorably with the direct-current machine, especially
in large units for rolling-mill drives, mine fans, etc.,
and in some cases it shows an advantage over the
direct-current machine. For example, in 1913 a 600-hp.,
2200-volt adjustable-speed polyphase induction-motor set
for driving a rolling-mill was installed, having six differ-
ent synchronous speed adjustments between the limits
of 300 and 500 r.p.m. This set consists of two machines
arranged so that they can be connected in cascade. The
primary motor has a phase-wound rotor with its stator
wound for 14 and 16 poles; the secondary motor is a
squirrel-cage machine having its stator winding arranged
so that it can be grouped for 4- or 8-pole connections.
It is worthy of note that this set was chosen in preference
to a direct-current machine, and that it has proved very
satisfactory in service.
A. A. Fredericks.
New York City.
The illustration shows a method I used in realigning
a belt-driven exciter so the belt would not slip off under
heavy load.
The material required consists of four pieces of angle
iron selected in proportion to the size of the machine.
The combination of lateral and transverse slots gives free-
Slide Rail
~\
Jlt^O/d 'Foundation
J£\' bolts "A^n
iiiiiiiiiifmiiiiiiiniiiiiiiiiiiiiiiliiiiiiiiiiiiiiiiini////
dom of motion to square up the machine. For ordinary
aligning four symmetrical angles will do. However, should
a machine have to be shifted endwise considerably, slots
can be cut in the foundation angle bars.
Feed E. Walchli.
Kalispell, Mont.
Dashpot
TVe had considerable trouble in keeping the latch blocks
and plates in good condition and the cutoff equalized on
a Brown twin-engine. It was im-
possible to maintain an equal cutoff
or equal distribution of the load be-
tween the two sides.
The valve-stem stuffing-boxes be-
ing very shallow, it is difficult to
prevent some leakage, and most of
the time there is more or less water
dripping into the dashpots. A sort
of drip cup is provided under the
stuffing-boxes, intended to catch
and carry off the leakage, but it is
of little value. It is desirable to
keep water away from the valve
gear because it washes off the oil,
but there is no room to put a
shield where it will do the most
good. I therefore arranged a sheet-
metal hood over each dashpot, as
shown in the illustration. Pre-
vious to this we were tinkering with
latch blocks and plates and adjust-
ments continually, but now the en-
gine runs for months without requiring more than slight
adjustments to the valve gear.
H. L. Strong.
Yarmouthville, Maine.
Hood in Place
^-■(MAKE 4 ANGLES THUS)
Material for Mounting Generator
The terminals of some field coils are so located that
it' the coil has been turned over or turned end for end
while installing, the appearance of the terminals makes
the mistake evident. There are coils, however, which
may be inverted without the appearance of the ter-
minals suggesting any irregular condition. The terminals
of such coils are located in the centers of opposite sides
or of opposite ends, and the coil appears the same
irrespective of the manner in which it may have been
installed. Any such mistake which results in the current
circulating in the wrong direction will reverse the
polarity of the coil, and if the number of reversed coils
is a sufficiently large proportion of the total number, the
machine will be unable to build up its field. At all
events, the voltage obtainable will be reduced and com-
mutation will be impaired.
An inspector was called to locate the trouble in a gen-
erator that was unable to build up its field; even when
the machine was separately excited from another, the
value of the voltage obtainable was very small. The
machine had been in a flood and had been disassembled
for cleaning. The operator stated that he had marked
the field spools when removing them and that he had
June 2!). 1915
TOW E K
893
replaced them just as they hud been marked. He
evidently either had marked the spools incorrectly or
had failed to observe the marks carefully while re-
assembling, because on raising the brushes, exciting the
Held from another machine and testing the polarity with
a nail, all the bottom poles were found to be of the
same polarity.
The terminals of the field coils were in the centers of
opposite ends of the coils and two alternate coils had
heen installed end for end. thereby reversing two coils
out of five and making five consecutive similar poles.
An inspection of the direction arrows stamped on the
flanges of the held spools confirmed the supposition.
Where the marks on the flanges are not plain or where
there is any doubt as to how a coil should he placed, the
best plan is to temporarily place and connect the coil
and test the polarity with a nail or compass. Where a
compass is used by an inexperienced person, it is best
that the test be made with the armature withdrawn;
otherwise, the poles induced in the armature core by the
polepieces may cause misleading results.
E. C. Parham.
Schenectady, N. Y.
':■'
lEsrfhisi^is&^GrgiS M©a.ft®dl Boileir
In one of the power houses of a large engineering works
where gas made from bituminous coal supplied the motive
power, the heat from the engine exhaust was utilized to
generate the steam supplied to the gas producers. The
plant was run with the ammonia-recovery process, thus
requiring 1 to 1.25 lb. of steam for every pound of coal
5l
Safety Valve
Steam Outlet
TT Gusset Plate
lop Row\ of Tubes\
rT-
—ll'-li"-
IL
Drain Blortoff
■19-7%
Section through Boiler
used. Three 1000-hp. engines and exhaust boilers were
to be installed, although only one unit was at first put in.
The exhaust pipe was 30 in. in diameter and had two
gate valves arranged so that the gases could be led
either to the boiler, from which they entered a large
masonry chamber, or silencer, built in the ground, or
they could travel directly to the silencer.
The sketch shows the boiler, which evaporates 2.5 lb.
of water at 100 lb. per sq.in. per brake horsepower
delivered by the engine. It was of horizontal cylindrical
construction, 1!) ft. 7% in. in length and 7 ft. 5 in. least
internal diameter, the sides being V<rm- plate and the ends
of %-in. plate; the tube-sheets were % in. There were
182 tubes, S^-in. outside diameter at 4%-in. pitch,
giving over 1700 sq.ft. of heating surface. The tube
sheets were stayed by seven 1 Vo-in. stays, and midway
the tubes were supported by a plate cut out at intervals
around the circumference to permit of freer circulation
of the water.
The exhaust gases entered the firebrick-lined compart-
ment shown and, after passing through the tubes, entered
a 3V2-ft. compartment, also supplied with a manhole
and drain, and then through a 30xl8-in. reducer to the
silencer. The working level of the water was about 1 in.
above the top row of tubes.
The boiler was fitted with the usual safety valve,
manhole, steam and water gages, a 3-in. steam connec-
tion for heating the feed-water tank, a 3-in. feed inlet,
a blowoff valve and mudholes, and was connected to
the gas producers by an 8-iu. steam line. Below the
steam opening in the boiler was a ^-in. copper plate
clearing the opening by 2% in., for preventing priming.
The heating surface of the tubes was 1723 sq.ft.
G. Moore.
Newark, N. J.
The lead gasket illustrated and described by F. W.
Beynolds in the issue of May 25, on page 725, has been
used with fair success under different conditions for many
years. A light piece of lead pipe is often employed for the
same purpose. Such a gasket may be improved by
drawing into the pipe a piece of asbestos rope to act
as an equalizing cushion.
James E. Noble.
Toronto, Ont.
If the stator coils of a three-phase induction motor are
delta-connected, each will be subjected to the full line
voltage; if Y-connected, however, each pair of line wires
will include two stator coils in series, in which case the
voltage per coil will be approximately 0.58 of the line
voltage. Moreover, in a Y-connected stator the current
of the line and of each coil is the same, whereas with the
delta connection the line current divides between two
paths. The operating characteristics of the motor will
vary accordingly as one or the other of these connections
is used, because the resistances and reactances involved
differ in the two cases.
For several years a three-phase induction motor had
successfully driven the compressor used for storing with
compressed air the whistle-blowing reservoir of a fire-
alarm system. Owing to continuous neglect of the
automatic governor, abnormal pressures obtained at
times, with the final result that the stator burned out.
It was rewound, after which, firemen in the outlying
districts began to miss fires and invariably gave the
excuse that they had not heard the whistle. Bepeated
trials proved the excuse to be well-grounded; the whistle
was inaudible in districts where it could be plainly heard,
even if an opposing wind were blowing, before the stator
was rewound.
Investigation disclosed that the motor was heating
abnormally and that it could store against only GO lb.
pressure, whereas it formerly had been able to store at
lfio lh. without any distress. Checking of the rotor
speed showed the slip at (iO lb. to be 240 r.p.m. On a
normal motor the slip would not have exceeded GO r.p.m.
The end shield was then removed and the connections in-
spected, and it was found that the coils which
bough! for the rewinding were greater in number and had
smaller wire than those of the original" winding. The
repairman had installed the new coils in the same manner
894
POWEE
Vol. 41, No. 26
as he had found the old ones, and in the absence of
instructions he was justified in doing so. The original
coils were Y-connected and the new ones were also, but
they should have been delta-connected.
J. A. HORTON.
Schenectady, N. Y.
I observed an engineer carefully pointing a pine plug
to drive in ms a substitute for a pump-cylinder cock that
was lost. Inquiry developed that lie believed the steam
would have less chance to blow the pointed plug out
than if the end was blunt.
Since then I have heard others pull off the same line
of argument. It is true, of course, that if steam or water
is issuing with considerable force a pointed plug may
be more easily entered, but that is "another story." I
hope I will not be classed as a "plug fitter" by reason
of the foregoing observations.
A. E. Baker.
Cambridge, Ohio.
Diagrams taken from a 9xl6x24-in. Corliss enaine
with the low-pressure cylinder disconnected for experi-
mental work showed a peculiar back-pressure line. The
Fig. 1. Diagram Indicates Leakage
Pig. 2. Condition after Increasing Tension
Fig.
Steel Spring to Give Tension to Ring
hump in the exhaust line, shown in Fig. 1, would appear
on the head end for a day or so, then show up on the
i rank end for a few days, and then back to the head
end again, owing to sonic change in the position of the
piston ring.
A piece of heavy clock-spring was filed and peened to
fit, as shown at A. Fig. 3, and just long enough not to
bind when the ring was compressed. The joint was open
about vV of. an inch when compressed to the cylinder size,
allowing sufficient clearance for the spring. Before in-
serting the piston in the cylinder the joint of the ring
was turned to the top of the piston to prevent spring A
working loose and cutting the cylinder. Other diagrams
were takeri after this change, with results as shown in
Fig. ■>.
William Smith.
Union Hill, N. J.
m
The accompanying illustration shows a chain com-
pensator for a Corliss engine governor. The chain has
all of thi' advantages of a gag pot, and in addition the
governor will take hold quicker in bringing an engine
up to speed when starting up than if a gag pot is used.
Heavy Steel-' t
Chain Cable 9 9 ^T
Links \, JStiid
Bolt
Chain Compensator for a Corliss Engine
Governor
When the governor balls are in their lowest position the
major part of the chain pulls down on the lever, and
when the balls are in their highest, position the major
part if the chain is supported by the standard.
C. E. Bascom
Westtield, Mass.
:*:
S&oifinm D©iam©15§Ihi©dl Two §&s\clrXs
On the night of May 27, a storm blew down the two
30-in. x 75-ft. smoke-stacks of the Moberlv artificial ice
plant at Moberly, -Mo. Only one boiler was in use at the
time. and. strangely, the 1%-in. water-column pipe was
torn out from that boiler, blowing all the water out. The
stack fell in such a way that it did not damage the build-
ing or equipment except as stated.
C. F. Doetiring.
Moberly, Mo.
June 29, 1915
PO w hi;
895
'I'liraimm
'.".:...
Isnq^uiiiraes of Gemieral ImnleresH
sin iiiiiiiiiiiiiiiiiiiiimiimi mnii n iiiiiiiiiiiniiiiii iiiiiiiiiiiiiiiimiii mi iiiiiiiiiiiiiiiiiiiiiniiiiiiii iniiniiiiii mini iimnn limn imiiiiiii i inimmiiminmiii i ritfrtiniiinr inn mill mm iimiiiiminis
Weight of Spanish I.ilirn — What is the relation between the
weight of the Spanish pound used in Latin-American countries
and the avoirdupois pound of the United States?
P. P. C.
The Spanish "pound," or more properly "libra," is equal to
1.0161 United States avoirdupois pounds, or 1 lb., 0.2676 oz.
Capacity of Pump — What is the capacity, in gallons per
minute, of a duplex steam pump with water cylinders 6 in.
diameter, when running at a piston speed of 90 ft. per min.?
E. P.
Without allowing for reduction by presence of the piston
rod, the piston displacement in each water cylinder would be
(6 X 6 X 0.7854) X 90 X 12 = 30,536.35 cu.in. per min.
and, without allowance for slippage, the combined pumpage
of two water cylinders would be
(2 X 30,536) -=- 231 cu.in. per gal. = 264.4 gal. per min.
and, allowing 5 per cent, slippage, the delivery would be
264.4 X 0.95 = 251.18 gal. per min.
Factor of Evaporation with Superheated Steam — What
would be the factor of evaporation in the generation of steam
at 135 lb. gage pressure with 100 deg. of superheat, from feed
water at 200 deg. P.?
R. J. F.
A gage pressure of 135 lb. per sq.in. would be equivalent to
about 150 lb. absolute, and by reference to Marks and Davis'
Steam Tables it is found that a pound of steam at 150 lb.
absolute, when superheated 100 deg. F., contains 1249.6 B.t.u.
above 32 deg. As the latent heat of steam at 212 deg. F. is
970.4, then, as compared with evaporation from and at 212
deg. F., the factor of evaporation would be
1249.6 — (200 — 32)
= 1.1146
970.4
Testing Flow of Steam — How can a test be made of the
weight of steam used by a small steam pump?
W. L. B.
If one of the several types of steam meters is not available,
a close approximation to the rate of flow can be determined
for a stated pump speed and other operating conditions by
placing a gaging stop valve in the steam line to the pump
and ascertaining the flow that takes place through such a
valve under the same conditions of valve opening and pressure
on each side of the valve as when the pump is in operation.
For the purpose, place a pressure gage on each side of the
valve and. with the gaging valve partly closed, observe the
indication of each pressure gage while the pump is in opera-
tion. Then, with the pump shut down, determine, by increase
of weight, the rate at which the steam condenses when dis-
charging without loss into about three-fourths of a barrel
of water, having the same opening of the gaging valve and
same readings of the pressure gages as when the pump was
in use. The pressure on the discharge side of the stop valve
can be regulated by throttling the escape of steam to the
condensing water.
Relative Economy with Different Initial Pressures — What
would be the relative economy of employing steam at an
initial pressure of 75 lb. and at 100-lb. gage pressure per sq.in.,
if in each instance the clearance is 5 per cent., cutoff at %
of the stroke, the average back-pressure 4 lb. gage and the
boiler-feed water 200 deg. F.?
G. K.
By referring to a table of mean pressures per pound of
initial pressure with different clearances and points of cutoff
(such as given on page 115 of Low's "Steam Engine Indi-
cator"), it may be seen that with cutoff at % stroke and
5 per cent, clearance, the mean pressure per pound initial
absolute would be 0.6258 lb. Therefore, with an initial pres-
sure of 75 lb. gage, which is equal to about 75 -4- 15, or 90, lb.
absolute, and back-pressure of 4 lb. gage, or 4 + 15 = 19 lb.
absolute, the mean effective pressure would be
(90 X 0.6258) — 19 = 37.322,
and with an initial pressure of 100 lb. gage, or 115 lb. abso-
lute, and the same average back-pressure, the mean effective
pressure would be
(115 X 0.6258) — 19 = 52.967 lb.
As the density of steam at 90 lb. absolute is 0.2044 lb. per cu.ft.,
and of steam at 115 lb. absolute is 0.2577 lb. p.r cu.ft., then
for the same cutoff and same diagram factors the relative
weight of steam required per pound m.e.p. would be as
0.2044 0.2577
to , or as 1.1256 to 1.
37.322 52.967
For comparison of cost, it may be assumed that in each
instance steam is generated from a feed-water temperature
of 200 deg. F. A pound (wt.) of steam at 90 lb. per sq.in.
absolute contains 1184.4 B.t.u. above 32 deg. F., hence each
pound raised from feed water at 200 deg. F. would require
1184.4 — (200 — 32) = 1016.4 B.t.u.
while a pound (wt.) of steam at 115 lb. per sq.in. absolute
contains 118S.8 B.t.u. above 32 deg. F, and each pound raised
from the same temperature of feed water would require
1188.8 — (200 — 32) = 1020.S B.t.u.
Therefore, the cost of steam required per lb. m.e.p. or per hp.,
employing 75 lb. boiler pressure, would be to the cost employ-
ing steam at 100 lb. boiler pressure as
1.1256 X 1016.4 to 1 X 1020.8, or as 1.1207 to 1.
Action of Bourdon «agc Tube — What causes the tube of an
ordinary Bourdon spring pressure gage to become straighter
for an increase of pressure?
J. R.
As the tube is curved and flattened at right angles to the
plane of curvature, when inflated there is a tendency for it
to assume a circular form of cross-section, giving rise to
tensile stress in the tube material which forms the outside
of the curve and compressive stress in the material forming
the inside of the curve.
Diagram Illustrating Action of Gage Tube
The action is the same as though the curved tube was com-
posed, as shown in the figure, of a number of straight tubes
of cross-section like ACDB joined together in polygonal form
EFGHJ. Such sections, when independently inflated to the
oval form of cross-section acdb, would be represented by the
trapezoids E^EjEi, FiF»F3F4, etc. But, as shown by the
figure, when the sections are thus separately inflated, they
would separate along the outer, or convex, side as at H2KJi
and would be compressed together along the inner, or con-
cave, side of the tube as indicated by the overlapping J,KHS.
Hence, after inflation of the sections, when a section like H
remains continuous with an adjacent section like J, the latter
being held stationary, then for H- to remain in contact with
Ji and for H;) to remain at J«, the inflated section H would
have to assume the position H5J1J4. Like movement of the
consecutive sections would result in a change in their align-
mi Tit to that indicated by the dotted lines, and the action of
straightening out from inflation would be similar if the orig-
inal sections "were short enough to form a continuous curve
of flattened tubing, such as used in the Bourdon spring pres-
sure gage.
[Correspondents sending us inquiries should sign their
communications with full names and post office addresses.
This is necessary to guarantee the good faith of the communi-
cations and for the inquiries to receive attention. — EDITOR.]
896
P 0 W E 1:
Vol. 41, No. 26
[eai&a?r&g M^an&s
During the last heating: season, engineers of the Merchants'
Heat & Light Co.. Indianapolis. Ind., have been making tests
to determine whether any part of the central hot-water
heating system in that city needed renewal. The tests were
also designed to discover the location of any overloaded sec-
tion of the piping system. The procedure of the tests was
as follows: Observers were stationed at the plant, at the end
of the main trunk line about 800 ft. from the plant, and at the
end of laterals about 3000 ft. from the trunk line. With these
watchers in readiness and with constant pressure maintained
on the system, the fires under the circulating boilers were
dropped simultaneously at a prearranged time. Immediately
afterward the fires were forced skillfully to bring the water
temperature back to normal. The various observers took
simultaneous time and temperature readings, noted the fall
in temperature as the cooler water passed their respective
stations and also the time that elapsed before the tem-
perature was restored to normal. With these data and
with the distance between stations known, a few simple cal-
culations gave the speed of the water in the mains and the
line losses in deg. F. occurring between the power plant
and the point of reading. The results were plotted with time
as ordinates and temperature as abscissas. The curve pro-
duced clearly showed the passage of the cooler water by a dip
in an otherwise comparatively straight line. Near the station
the readings showed the dip to be very pronounced. Further
out on the system it became more shallow. These dips gave
an indication of the relative line losses in the main and
laterals, while the velocity of the water was taken as the
most definite indication of the loaded conditions of the pipe,
high velocity indicating heavy loading, low velocity, light
loading. Considering velocities of 4 ft. per sec. in mains and
3 ft. per sec. in laterals as the maxima allowable, the test
data show conclusively that almost the entire system is in
good operating condition, although the lines were laid four-
teen years ago, and according to some theories of deprecia-
tion, should now be ready for replacement.
Readings were also taken on all lines to determine the
difference between the flow and the return pressure. These
data will be of value in considering future loading of the
lines, because in general customers should not be added to a
line with a differential pressure of less than 1 lb. per sq.in. —
"Electrical World."
iiragttoia
Through its Extension Division, the University of Wash-
ington, Seattle, has adopted an interesting plan to en-
courage the active development of local water power, afford-
ing free expert advice for proper and effective installations
at available properties. In this, the primary purpose is to
assist individual owners of water sites who might be unable
at the moment to employ experienced engineering talent, as
well as small rural communities similarly situated, inspiring
active interest in the possibilities presented.
The inauguration of this department has led to consider-
able activity along cooperative lines. Owners have been sup-
plied with information applicable to service, in a consistent,
economical and profitable way. In some cases recommenda-
tions to employ consulting engineers have been made, it be-
ing the particular province of the university to suggest the
most feasible plan, with all essential data, rather than carry
the proposed project to completion.
In explanation of this new public consulting department,
the university calls to notice that hundreds of small water
powers are still undeveloped in the state. Many farms and
country homes are so situated that electric power for light-
ing and cooking could be secured at a very reasonable cost,
while in some cases, heating by electricity is possible at an
economical figure. Investigations show that a large propor-
tion of the small water powers are worthy of the utmost de-
velopment. Owners do not always know the value of their
sites and on such uncertainty cannot afford to employ an en-
gineer capable of giving the necessary advice; on the other
hand the engineer cannot afford to give his services free.
As regards the working of the plan, the University of
Washington, being a state institution, is in a position to lend
assistance by sending an expert to report on the advisability
of development. If no extended surveys are required, this en-
gineer will suggest a proper method of procedure and prob-
ably make some little sketch to be followed in the construc-
tion. Should surveys be necessary and the expense is justi-
fied, it will be so reported and the owner asked to secure
some private engineer to make them, provided the owner
wishes it done at his expense. No charge is made for the
information or technical advice given out by the university
engineer, excepting his necessary traveling expenses, which
must be borne by the person asking his services.
CoimwgEa&aoia ©IF Atnmeir'acsiia Boiler
The twenty-seventh annual convention of the American
Boiler Manufacturers' Association, held at the Hotel Lawrence,
Erie, Penn., was called to order by the president, W. C. Con-
nelly, on June 21, with 10S manufacturers' representatives
present. The report of the committee on uniform boiler laws
recited the efforts which had culminated in the A. S. M. E.
code. Thomas E. Durban, chairman of the committee, said
that the industrial commissions of Pennsylvania and Wisconsin
had already adopted the code. He was assured that California,
Chicago and St. Louis would adopt, and that the conservative
Master Boiler Builders' Association had already approved
the code. N. A. Baumhart, chairman of the Ohio Board of
Boiler Rules, told the convention that the Ohio rules would
be amended to include the A. S. M. E. code. John A. Stevens,
chairman of the A. S. M. E. committee that formulated the
code, urged its promulgation on behalf of the consulting
engineer.
C. H. Wirmel, formerly head of the Ohio Boiler Inspection
Department and chairman of the N. A. S. E. committee on
legislation, invited the attendance of those interested in the
general adoption of the code at the N. A. S. E. convention to
be held at Columbus, Ohio, in September. John T. McCabe,
boiler inspector of Detroit, approved the code, but held that
the city or state could only prescribe absolute essentials, and
even then the burden of proof rests on the inspector. He
also announced that he would pass A. S. M. E. boilers wherever
made. Dr. C. L. Huston stated that "two dollars per ton"
was not the only difference between furnace and flange steel.
The firebox plates, which are stressed by unequal tempera-
tures, required more rigid inspection. The steel used should be
openhearth selected from the middle of the run, and there
should be closer supervision of the entire process. Mr. Lynch,
representing the Association of Steel Manufacturers, testified
to its approval of the code, which was a credit to Messrs.
Stevens and Durban. H. P. Goodling, speaking for the
portable-engine interests, said the principal objections to the
enforcement of the code would be the inspection and license
requirements. The attempt to adopt such measures in Florida
had been frustrated because the small operators were afraid
they would have to employ licensed men. Michael Fogarty,
a delegate to the New York Constitutional Convention, said
that a boiler law must be passed before the code could be
adopted. At his request the convention adopted a resolution
indorsing a proposed constitutional amendment. A copy
of the resolution was sent to the Hon. Herbert Parsons, chair-
man of the committee on industrial relations of the New
York Constitutional Convention. T. W. Herendeen, secretary
of the National Boiler and Radiator Manufacturers' Associa-
tion, expressed his association's approval of the code and
pledged cooperation in securing its general adoption. G. S.
Barnum, of the Bigelow Boiler Works, told of a rumor that
a law or rule might be passed admitting code boilers to
Massachusetts. T. M. Rees, of Pittsburgh, belatedly protested
against the adoption of the code. He especially objected to
its condemnation of lever safety valves and lap joints, quoting
"Power" to show butt-strap joints were not immune from
cracks. The convention voted to refer his objections to the
committee on A S. M. E. boiler code. C. V. Kellogg, president
of the National Tubular Boiler Makers' Association, told of
its activities and expressed sympathy with the A. S. M. E.'s
efforts to promulgate the boiler code.
President Connelly recommended for consideration: The
adoption of uniform specifications covering material guaran-
ty s, workmanship and methods of payment; ways and means
to secure universal adoption of the A. S. M. E. code; the
securing of laws whereby boilers approved by authorities in
one state should be recognized as good in all states; the action
of water-tube boiler manufacturers in guaranteeing boilers
for 200-per cent, capacity, thus cutting the market for boilers
in half.
The convention decided to form an administrative council
consisting of one member each from the American Boiler
Manufacturers' Association and from other allied organiza-
tions. This council will conduct a campaign for the adoption
of the boiler code, the campaign expenses to he prorated
among the interests represented, to the amount of $12,000 a
June 29, 1915
pow E i;
897
year. A model inspection and license law was referred to
this council to be modified and adapted to conditions in various
parts of the country. H. D. Mackinnon presented a report
of the committee on uniform cost system. The convention
adopted suitable resolutions on the deaths of Past-President
B. D. Meier and Past-Treasurer Joseph P. Wrangler. The
following officers were elected: President, W. C. Connelly
(reelected); first vice-president, C. V. Kellogg; second vice-
president, G. P. Barnum; third vice-president, 10. C. Fisher;
fourth vice-president, Isaac Harter, Jr.; fifth vice-president,
Charles F. Hooper; secretary, J. D. Farasey; treasurer, H. N.
Covcll; representative on administrative council, E. R. Fish.
Past-Presidents Richard Hammond and Henry J. Hartley were
elected honorary members. Fifteen firms joined the associa-
tion during tlie past year, making S7 companies and 15
associate members enrolled. Six of the fifty charter members
were present at the convention. The convention passed a vote
thanking the Brie City Iron Works, Union Iron Works, Burke
Electric Co., and the visitors that had contributed to the
discussion and the committee work. The business sessions
concluded with a banquet at the Hotel Lawrence on the
evening of June 22.
amid Vfeiiii^iiiL®^
r>\ a. ii. Baekeb
SYNOPSIS — The author discusses the general
nature of unsolved heating and ventilation prob-
lems and outlines some interesting experimental
work now being conducted at the University Col-
lege.
The twin sciences of heating and ventilating have more
unexplored problems and greater difficulties attending their
solution than almost any other branch of engineering. This
is due to the immense complexity of the two sciences, the
difficulty of defining in exact terms the results to be expected
and the fact that the criterion of success has of necessity
been the feelings of individuals rather than the readings
of scientific instruments. In addition, the immense power of
adaptability of the human organism tends to make actual
variations of conditions appear unimportant in practice. In
this branch the first obstacle is the great difficulty of finding
the facts.
Consider, for instance, the first problem for an engineer
endeavoring, without previous experience, to arrange a satis-
factory scheme for ventilating a building. He would begin
with the assumption that the artificial ventilation of a build-
ing consists of forcing in a calculated volume of air. If he
were familiar with fans and the laws of the flow of air in
ducts, he might think the task easily accomplished. But
after he had once tried to satisfy the occupants of the build-
ing, he would find the distribution of air currents- a problem
of great difficulty even in a small building. Although each
of these currents obeys rigidly accurate laws of nature, as a
whole they are so complex that their expression as terms of
exact science is almost impossible. Complaints of the ventila-
tion of almost every public room are heard, but should the
ventilating engineer be held responsible when no one can
specify what is wrong or what is needed to put it right?
The arrangement of a satisfactory heating system is no
less complex. Heat is delivered into the room by convection
currents of heated air and by radiant energy. These forms
of heat are quite different from each other, yet they can be
instantaneously transformed from one to the other and back
again. Their measurement, a^ain, is not a problem to be
easily solved. The mere act of measuring the amount of
radiant energy turns all or part of it into convected heat.
The most baffling difficulty, however, in the attempt to
reduce this subject to an ordered science is that the object
of both heating and ventilating, though primarily physio-
logical, is also to some extent psychological. The primary
object is to keep the inhabited rooms healthful; to keep them
comfortable is of almost equal importance. The effect of any
given condition on the human body is, if possible, more com-
plicated than the laws which govern air currents and heat
flow. The author believes that in the interests of health the
temperature maintained should be as low as can be endured
without real discomfort. Yet others will say that the room
should be so warm that the occupants feel comfortable
without any effort. No one can tell us within 300 per cent,
how much fresh air per head per hour is the minimum con-
sistent with health. A room filled with air absolutely pure,
so far as chemical analysis can detect, may feel very stuffy.
For instance, in the House of Commons the air is, chemically
speaking, as pure as in any room in the world. No less than
•From a paper read before the Society of Engineers (Inc.),
in England, and abstracted in "The Mechanical Engineer."
13,000 cu.ft. of air is supplied per head per hour, yet it
produces the effects associated with defective ventilation —
lassitude, sleepiness, and infection. A room may, on the
contrary, feel fresh and sweet when, judged by chemical
standards, the air is very bad. The author has analyzed air
containing 25 volumes per 10,000 of C02, which felt as fresh
as a spring morning, although 10 volumes is regarded as
the extreme allowable impurity.
The future of heating and ventilating depends, on the
scientific side, upon the further analysis of the conditions that
produce the feeling of comfort and other effects. This half
of the problem is for the psychologist. The attempt to specify
healthful and comfortable conditions involves experiments,
that in essence are attempts to calibrate human beings.
The practical side of the problem depends on the controlling
of these conditions and on the further development of con-
struction and transmission apparatus. We must first be able
to express exactly each of the chemical and physical condi-
tions which make up the sum total of the room condition.
The criterion of successful design must not be the self-
contradictory feeling of people, but must be the exact reading
of radiometers, hygrometers, airmeters, apparatus for the
analysis of air, dust counters, thermometers and other instru-
ments.
The practical problem is to introduce heat in quantity
and form to make the building comfortable. As heat can
be introduced by convection currents and by radiation, there
will be at least two corresponding temperature conditions in
a room. The expression "temperature of a room" commonly
means the reading of a correct thermometer in the room.
This thermometer does not indicate the temperature of the
surrounding air, for it is largely influenced by the amount
of radiant energy impinging on the bulb and having no con-
nection with the air temperature. The problem is not solved
when the heaf causes a thermometer in a room to read a
certain figure. Of course, in designing a large system a
great deal of calculation is required to obtain a uniform and
proportional flow to all parts of the apparatus. Even when
this is done a large number of persons undoubtedly cannot
» ndure apparatus heat in any shape.
To get to the bottom of the problem the temperature of
the air itself and the temperature corresponding to the radiant
conditions should be studied. To make a systematic beginning
we must also develop experimental means for recognizing and
measuring air and radiant temperatures, and quantities of
convected heat and radiant energy. It is necessary to de-
termine experimentally the relation between the thermometer
rating, the air temperature and the radiant temperature. The
term "radiant temperature" signifies the temperature regis-
tered by a thermometer if there were no air in the room at
all — a sort of mean of the temperature of the surrounding
walls.
Separate instruments have been devised at the University
College for registering the air and radiant temperatures.
The first shows the mean temperature of all exposed surfaces,
such as the walls of the room and the furniture, affecting the
bulb of the thermometer. The principle of the instrument is
to surround a delicate thermometer with air at the same
temperature as that of the room, and also to envelop it with
a surface whose temperature can be adjusted to any degree
and held absolutely uniform. The instrument for finding the
temperature of air is constructed on the principle that a
thermometer surrounded both bj air and by double-walled
surfaces at the same temperature as the air in the room will
read exactly the temperature of the room air. Tf the radiant
mi air temperatures are made Identical, both will be the
same as the thermometer reading.
898
1' I) W K K
Vol. 41, JNO. Zt>
The author claims to have proved with these instruments
that the stuffy feeling often associated with heating systems
is caused largely by too high air, and too low radiant tem-
peratures. The freshness of a building depends on keeping
the air temperature relatively low and the radiant temperature
high. This explains why a room warmed by an open fire
often feels much more comfortable than one heated by a
radiator. The temperature and humidity of the air are the
important points, and not its chemical freshness, freedom from
C02 or from other organic products.
In this connection it is important to separate the heat
communicated to a room as radiant energy from that com-
municated by warming the air. In an apparatus contrived
for this purpose, a canopy collects all the warm convection
currents proceeding from the heater. A delicate electrical
method is applied for testing the quantity and temperature of
the heat. The heater is surrounded by radiant-heat meters,
such as radiometers and thermopiles.
The effect on the human organism of dust in the air must
be determined, but as there are millions of particles per
cubic inch, special methods are required for counting them.
In the "Aitken" dust counter a minute sample is measured
and diluted largely with a known quantity of pure and
dustless air. The particles of dust in a fraction of this
enlarged volume are deposited on a glass plate underneath
a microscope and actually counted. By multiplying by the
total number in a cubic inch, the original sample can be
calculated.
In no respect has the science of heating and ventilation
been more backward than in the knowledge of laws governing
the movements of air. The flow of air is brought about by
the operation of very trifling momentary and constantly
varying causes. So, no doubt, is the flow of electricity in
relatively large quantities at low voltages. The ventilating
engineer is also concerned with a comparatively large flow
of air at low differences of potential. The electrician would
And difficulty in investigating the current through a cube of
copper measuring three feet in every direction. Local circuits
would be set up by any accidental distribution of electro-
motive force, such as those set up by the movements of a
magnet in the neighborhood. This exactly corresponds to the
problem with which the engineer is confronted in ventilating
a building. Air is introduced, for instance, into a room at a
certain point. At other points in the room, sometimes near,
sometimes remote, from the point at which the air is intro-
duced, currents of air which the occupants of the room call
"drafts," are experienced. It is held up as a reproach to
the ventilating engineer that these exist, and so no doubt
it is. Tet the laws of pneumatics are quite as definite as
those of electricity. The difficulty is in gaging and controlling
the working conditions. In developing experimentally the
laws of pneumatics on a basis somewhat similar to those of
electricity, standard units must be evolved comparable with
those of electrical science.
We are experimentally testing the validity in all kinds of
pneumatic flow of a fundamental formula similar to Ohm's
law. The law may be stated as H = RQ:. The unit of
aeromotive force H is naturally a foot of air column, or that
difference of pneumatic pressure against which it would
require one foot-pound of work to force one pound of air.
The unit of flow Q is one cubic foot of air per second. Since
the corresponding unit of resistance is closely equal to the
resistance of a hole 6 in. diameter in a thin flat plate, a
pressure equal to one foot of air column will cause a flow of
one cubic foot per second through the hole. If we can com-
pare all pneumatic resistances with this unit, we will under-
stand the flow of air better than when working with the
present complicated formulas. The fundamental difference
between the laws of pneumatic and of electrical flow is that
in the former the aeromotive force is nearly proportional to
the square of the flow, whereas with electricity the electro-
motive force is exactly proportional to its first power. These
differences are not sufficient to exclude the application of
similar experimental methods. A large apparatus, the pneu-
matic analogue of the Wheatstone bridge, is used for the
determination of pneumatic resistances, and sundry methods
of battery resistance have been applied to determine the
internal resistance of a fan. If we can specify the proper
resistance in pneumatic units for a boiler flue and chimney,
we can deal rationally with the much vexed chimney problem.
This problem has been treated only in the most incomplete
and perfunctory manner. We can determine, by the applica-
tion of these rules, the actual resistance of a boiler flue, and
can tell exactly the maximum capacity of a plant in heat
units or in pounds of steam, even without lighting the fire
in the boiler. To thus determine the resistance of boiler flues
and chimney shaft, it is only necessary to have a fan dis-
charge to the boiler through a chamber in which a constant
low pressure of air can be maintained. The resistance between
the fan and the boiler inlet is then varied, the current meas-
ured, and the pneumatic resistance can be at once established.
It is easy to show that the total resistance of a boiler
plant consisting of three Lancashire boilers, 28 ft. by 7 ft.
6 in., with a chimney 100 ft. tall, should be about 0.00172 unit
of resistance. It is even possible to determine this resistance
without a fan or an anemometer, but with a very accurate
micrometer pressure gage. By measuring accurately the
pressure in the inlet chambers due to the pull of the chimney,
the flow of air through the flues at any given moment can be
determined by calculation. The resistance of the boiler flues
and chimney in pneumatic units can then be easily found.
Enough has been said to show engineers that there is more
in this subject than the collection of rough rules of thumb
found in the current literature. At present, heating and
ventilation resemble mechanical science at the time of Newton,
or electrical science at the time of Faraday. It would be
very much to the advantage of mankind if engineers would
take more seriously a subject worthy of a high place in
practical science.
guilts of tlhe IL©c©raio4iv(
Iimspecttiomi ILaw*
By Prank McMANAMrf
The following table shows the inspection work performed
each year since the passage of the law three years and eight
months ago, and the decrease in the percentage of locomotives
reported defective indicates in a measure the improvement in
conditions:
1914 1913 1912
Number of locomotives inspected 92,716 90,346 74,234
Number found defective 49,137 54,522 48,768
Percentage found defective 52.9 60.3 65.7
Number ordered out of service 3,365 4,676 3,377
It does not, however, fully show the improved conditions
resulting from the operation of the law, because, as pointed
out in our 1913 report, attention was first concentrated on
the more serious defects, so that the number of fatalities
might be reduced; therefore, the improvement is more accur-
ately indicated by the reduction in the number of casualties,
as shown by the following table:
•From a paper before the Western Railway Club, Chicago.
tChief, boiler inspection department, Interstate Commerce
Commission.
1914 1913 1912
Number of accidents 555 820 856
Decrease from previous year, per cent... 32.3 4.2 ...
Decrease from 1912, per cent 35.1 ... ...
Number killed 23 36 91
Decrease from previous year, per cent... 36.1 60.4 ...
Decrease from 1912, per cent 74.7 ... ...
Number injured 614 911 1005
Decrease from previous year, per cent... 32.6 9.3 ...
Decrease from 1912, per cent 38.9 ... ...
The data cited are taken from the records up to July 1,
1914. A check of the first six months of the present year,
that is, from July 1, 1914, to Jan. 1, 1915, in comparison with
the corresponding period in the preceding years, shows the
following results:
During the period ended Jan. 1, 1914, there was a total of
349 accidents that resulted in injury, with 15 killed and 3S5
injured thereby. During the period ended Jan. 1, 1915, there
was a total of 253 accidents that resulted in injury, with 6
killed and 271 injured thereby, or a decrease of 27.5 per cent,
in the number of accidents, 60 per cent, in the number of
killed and 30 per cent, in the number injured by the failure
of locomotive boilers and their appurtenances.
June 29. 1915
PO W E i;
899
Going: back further and making a comparison with the
corresponding period for 1912, we find that during the six
months period ended Jan. 1, 1913, there were 470 accidents
that resulted in injury, with 24 killed and 512 injured thereby.
In other words, the number killed by failure of locomotive
boilers and their appurtenances during the first half of our
fiscal year beginning on July 1, 11112, was 12^ per cent, greater
than for the corresponding periods in the two following fiscal
years, with almost as great a decrease in the number Injured
and the number of accidents. Or, to state the whole matter
briefly, in three years the number killed by failure of Locomo
tive boilers and their appurtenances has been reduced from
about 100 per annum to less than one-fourth that number,
and the number injured from more than 1000 per annum to
less than one-half that number, with a corresponding decrease
in the number of accidents.
WHY LAW HAS REDUCED BOILER ACCIDENTS
These are the direct results of the operation of the Loco-
motive Boiler Inspection law and indicate the manner in
which it is fulfilling the purpose for which it was enacted —
to promote safety. The question will no doubt arise as to
just what the law has done to produce such results; and in
reply I will say that they are due to a number of reasons,
among which are more careful inspection, more prompt re-
pairs and attention to minor defects, investigation and classi-
fication of every accident that resulted in injury, with a view
to determining the cause and remedying it, and giving pub-
licity to the information collected.
FEDERAL INSPECTION PROMOTES BETTER MAINTE-
NANCE OF BOILERS
No railroad man with a trace of honesty and a knowledge
of conditions and practices prior to the passage of the law ran
question the fact that, generally speaking, inspections are
now more carefully and more regularly, and repairs more
promptly, made, and that the question of repairs is less apt
to be determined by the number of loads in the yard awaiting
movement, although unfortunately that is still occasionally
considered to be the deciding factor; an illustration being a
recent request by a master mechanic to operate a locomotive
with 43 broken stay-bolts a distance of 312 miles, because
they needed the power.
FIREBOX STUDS NEGLECTED
The importance of giving attention to minor defects can
be shown by an illustration: During the last fiscal year 18
persons were injured from studs blowing out of firebox or
wrapper sheets. In almost every instance they gave warning
of their defective condition by leaking before they blew out;
and they can be renewed with less expense to the company
at that time than after they blow out and cause injury. It
should be done, and the practice of repairing leaking studs
by calking, or permitting them to continue in service without
repairs, should be discontinued.
Investigating every accident to determine the cause, and
classifying it so that the number and causes of the various
accidents can be readily seen, has been an important factor
in shortening the accident list. This information is given
publicity in our annual report for the purpose of directing
attention to the causes of accidents so that they may be
avoided.
FEWER CROWN-SHEET FAILURES
I have recently had occasion to read care'ully statements
made before Congressional committees at the lime the boiler-
inspection law was pending, to the effect that all boiler ex-
plosions were real../ crown-sheet failures due to low water,
therefore, were man failures which could not be prevented by
Federal supervision; and still more recently have listened to
a repetition of these statements from a source which would
indicate that they represented the consensus of opinion of
railroad officials. To correct this misapprehension, attention
is directed to the records of such accidents since July 1, 1911.
During the year 1914, as compared with 1912, accidents
which are usually termed boiler explosions which resulted in
injury have decreased 44 per cent, or from 97 in 1912 to 54 in
1914, and the number of killed and injured has decreased 64
per cent., or from 290 to 104. During the same period crown-
sheet faiures due to low water decreased 48 per cent., or from
92 to 4S.
I am directing attention especially to this class of acci-
dents, first to show that such casualties as these, which were
said to be unpreventable, have been materially reduced, and
also because our investigations have shown that by proper
application and maintenance of boiler appurtenances they
can be still further reduced. I refer to the location, manner
of application and maintenance of such appurtenances as in-
jectors, gage-cocks and water glasses.
INCONVENIENT LOCATIONS OF GAGE GLASSES A MENACE
Rule 42 provides that "every boiler shall be equipped with
:it least <••!<■ water glass and three gage-cocks. The lowest
gage-cocks and the lowest reading or. the water glass shall be
not less than 3 In, above the highest point of the crown-
sheet." While it may be a compliance with the letter of the
law to locate these appurtei :es where they can be most
easily applied, regardless oi their convenience to the engine-
n. it is manifest!] not a compliance with the intent of the
law and Is nol conducive to safety, as an improper or incon-
venient locatl aj seriously Interfere with their proper
use. As an illustration of an impropei i n, a certain type
of locomotive has the water glass dlrectl; behind the engl-
i r and out of sight of the fireman. As these locomotives
are used In | vici on a busy division, where it is
at times necssary for the engineer to read a signal each 20
sei or less, it is certain that under such conditions the read-
ing of the water glass will not be as frequent as it would il
placed in a more i venlent location.
In other instances glasses are found so obscured by other
boiler appurtenances or by improper shields that it is diffi-
cult, and under- certain conditions impossible, to see the water
level. A recent investigation of a crown-sheet failure showed
that the cab arrangement was such that the water glass and
gage-cocks were !• in. above the engineer's head and that ne
regularly carried a small keg to climb upon to try the gage-
cocks. Can il be seriously questioned that such conditions
cause accidents, particularly when operating in a busy ter-
minal?
Using a shield that obstructs the 'view of the water glass
is also too common. In some Instances it has been found that
the shield almost entirely obscures the water glass. On deck-
less locomotives we frequently find the water glass located
behind the wind sheet or hack wall of the cab, in such a posi-
tion that only by leaving his usual position and peering in-
tently into the space between the boiler head and wind sheet
can the engineer see the water level. On the same type of
locomotives we find gage-cocks so located that to try them
the enginer must step back out of reach of the throttle, brake
valve and reverse lever. The inevitable result is that when
bJSy switching, or when trying to get a tonnage train over a
hill on a slippery rail, gage-cocks located out of reach are not
used as often as they otherwise would be.
VITAL IMPORTANCE 'if CORRECT LOCATION OF BOTTOM
GAGE-GLASS Fl ,'TING
The manner of application is also important, both as to
water glasses and gage-cocks; and in reference to this I will
quote a paragraph from a. paper I read before this club in
1913:
locateu wiiiiuui niucn regard to uie neigni 01 trie crown-sheet,
the proper height of the lowest reading of the glass being
obtained by the use of nipples of various lengths. When this
opening to the boiler is made below the highest point of the
crown-sheet, if the top water-glass cock is closed or the open-
ing restricted, water will show in the glass when there is
Having me ntting so applied mat me glass cannot under any
circumstances show water when the crown is bare, and this
means that the fitting should be so designed and located that
the proper reading of the glass can 1m- obtained and the open-
ing to the boiler kept above the crown-sheet.
I am referring to this again for the reason that investiga-
tions conducted since that time have shown positively that the
combination of conditions shown in that paragraph is one
cause of crown-sheet failures, one of which occurred quite
recently.
GAGE-COCKS AND THEIR DRIPPERS
We also find that the manner in which gage-cocks and
gage-cock drippers are applied indicates that the purpose
for which they were applied did not receive sufficient con-
sideration. While the application of a dripper is important
to prevent the discharge from the gage-cocks scalding
anyone in the cab, it should not be so close to the cocks that
the nipples extend down into the dripper, preventing engine-
men from seeing the discharge, as dripper pipes occasionally
become obstructed and till with water, in which event the
sound of water and steam are identical.
This is not offered as an excuse for crown-sheet failures
due to low water, because we believe there are no excuses;
but our investigations have shown that these conditions are
sometimes the cause of such accidents; therefore, sufficient
care and foresight should be exercised to so apply all these
appurtenances that they will to the best advantage serve the
purpose for which they are required
900
pow b n
Vol. 41, No. 26
FREQUENT FAILURES OF INJECTOR STEAM PIPES
Failure of injector steam pipes continues to be one of the
most frequent causes of serious accidents, and is the only
one which shews an increase during the present fiscal year
over the corresponding period for the previous year.
Of 16 injector steam-pipe failures five were due to nuts
breaking, one to threads stripping, one to a nut being too large,
five to collar or sleeve breaking and four to defective brazing.
Each of the accidents due to the nut breaking or stripping
resulted from attempting to tighten the joint without shutting
off the pressure, for which the remedy is obvious, although
perhaps somewhat difficult to apply.
BRAZED JOINTS DANGEROUS UNLESS REINFORCED
The other nine failures, four of which were due to poor
brazing and five to collar or sleeve breaking, could, I believe,
have been prevented by extending the pipe through the collar
or sleeve and flanging or beading it, thus reinforcing the
collar and reducing the strain on it, as the end of the pipe
itself will be solidly held in the joint; therefore, it will carry
the load. If properly applied in this way. brazing is not nec-
essary, although it can be done if desired. This method of ap-
plication is at least as cheap as brazing, and defective or im-
proper workmanship can be discovered by inspection, which
is impossible with the brazed connection.
The discussion on the location of the bottom fittings of
gage-glasses was to the effect that that fitting should always
be placed above the highest point of the crown-sheet, not-
withstanding the complaint of some engineers that such loca-
tion prevents a timely warning of foaming.
W.
Fnael°Oil for Locomotive Use*
From 1907 to 1914 the use of fuel oil by railroads increased
112 per cent., until a total of 31,000 miles, distributed over
50 railways, was operated with this fuel. For a time during
the years 1912 and 1913 there appeared to be a tendency to
discontinue the use of oil, on account of the great demand for
the distilled products of crude oil used for other purposes,
leaving a diminished supply of fuel oil and residuum. Open-
ing up of new fields, more efficient methods of distillation, the
production of gasoline from natural gas, etc., have again in-
creased the fuel oil suppl;., and its use is again extending.
In the combustion of fuel oil, where a steam spray is used
for vaporization, we are confronted with the fact that in the
process of atomization the particles of oil are started on their
way to the flues even before they are partly burned. The first
result of these particles coming into the heated portion of the
furnace is to separate the carbon from the hydrogen, the
former thus being left as a fine dust floating in the furnace
in such a manner as to be easily carried to the flues uncon-
sumed, to be deposited as an insulating layer of soot, or to be
carried out of the stack in the form of black smoke. If these
fine particles of carbon were attached, as in a bed of coals, a
supply of air could easily complete their combustion. With
liquid fuel, therefore, the diffusion must be simultaneous with
ignition, with the resultant long flame. The surface tension
of oil, especially when the particles are finely divided, is such
as to make the drops assume a spherical form of extreme
rigidity and therefore expose the least possible area to the
oxygen. We are thus brought to realize that large furnace
volume is essential to the burning of fuel oil. While the rela-
tive dimensions are of minor import to the volume, it is evi-
dent that a flame passage of sufficient length to prevent un-
consumed particles passing to the flues must be provided. It
was the realization of the limited volume of the locomotive
furnace that brought about the change from back- to front-
end burner arrangement a few years ago, in an attempt to
lengthen the flame path.
While it is generally conceded that lack of oxygen is
responsible for smoke, the restricted furnace volume and the
attending lack of time for the proper mixture of the gases in
the more highly heated portion of the furnace is the most
common cause for black smoke from an oil-burning locomo-
tive. One of the difficulties met with in the use of oil in the
locomotive is the frequent necessity for the removal of soot
from the flues, by means of sanding out. This, of course, is
attended with several disadvantages, not the least of which is
the resultant loss of fuel.
Special attention is brought to this point in connection
with locomotive oil-burner furnace design because of the
general tendency to restrict the furnace volume by carrying
draft pan and brickwork too high in the firebox, covering up
valuable heating surface and bringing about the continual
necessity for forcing the fire at the expense of the remaining
exposed surfaces.
One of the principal requirements in the burning of oil is
to expose the fuel to the furnace heat so that the greatest
possible area is presented to the oxygen. A study of the
atomization of oil is therefore of some importance, and it will
be readily seen that the stretching of the surface of fuel oil
is a study of capillary action and that it is not hard to deter-
mine the work necessary. Oil in bulk has little surface, but
when broken up into fine particles it has the combined surface
of the spherical areas of the drops thus formed, and the work
of atomization is the work of stretching the surface o' ex-
posure.
Theoretically, it should be possible to atomize oil to a
definite fineness of spray by means of a mechanical device
much more economically than by means of the steam jet.
•Abstract of paper read by G. M. Bean before the Inter-
national Railway Fuel Association, Chicago, May 17-20, 1915.
Fig. 1. Burner at Back of Furnace
Many attempts have been made along this line, with almost
as many failures. The simplicity and flexibility of the steam-
jet burner make that method difficult to improve, and the fact
that the type of burner now in use on the majority of locomo-
tives is practically the same as the one first introduced in
this country would lead to the belief that when improvement
is made in the oil-burning locomotive furnace, it will not
be made in the burner. One of the simplest of all burners
and now standard on the Santa Fe Ry. has been in continu-
ous use on that line since oil was first introduced as fuel, and
has never failed, in itself, to show up well in connection with
any furnace design. In other words, where failures in design
or arrangement were met with, it was always traced to other
features being wrong, rather than the burner. The type of
burner therefore seems of minor importance, so long as it is
simple, substantial, not easily stopped up and easily cleaned.
Locomotive furnaces are not considered ideal for the use of
fuel oil, and for this reason as much as any other there have
been as many different furnace arrangements as there have
been localities in which oil fuel has been used.
At the first inception of the idea in this country it was
natural that the designs used in Russia should be followed.
The burner was placed under the rear of the firebox, Fig. 1,
and directed forward with an upward incline, so that the
flame shot under a low, short brick arch, with the result that
combustion became so intense in this limited space as to cause
the flame to pass from under the arch with such velocity as
to impinge on the door-sheet, side-sheets and crown-sheet,
with detrimental results. Bad water conditions throughout
the Southwest aggravated this to such an extent that the life
of fireboxes was only about eighteen months or two years,
and the replacing of them soon became a severe burden. The
back-end burner arrangement also required an excessive
quantity of firebrick, which not only gave trouble by continu-
ally burning out, but also served to cover up valuable heating
surface, restrict the furnace volume and throw an increased
load on the remaining heating surface.
While the back-end burner arrangement is still in use to
some extent throughout Texas, it has entirely disappeared
from every other section. The burner is now placed in the
front end of the draft pan. Fig. 2, and directed toward the
rear in such a manner that the draft is forced to reverse the
direction of the flame before it passes to the flues. The
furnace is open, the brickwork is kept low and the maximum
of heating surface is exposed. The correct drafting of this
arrangement is still a somewhat debatable subject, but the
general idea seems to favor the admission of the principal
volume of air through openings in the vicinity of the flash-
June B9, 1915
POWEK
901
wall, whtch is built up under the door, it being the plan to
admit this air through numerous small openings, preferably
circular in shape and distributed well over the rear third of
the draft pan in such a manner that the air is brought in
contact with the flame from several directions and not in
too concentrated a volume. A small amount is also admitted
around or under the burner, so as to prevent it from over*
heating and to keep the flame from dragging on the floor of the
pan. This arrangement results in a uniform distribution of
heat and the consequent lengthened life of the fireboxes and
flues, until it can safely be said that for service under like
conditions, a firebox on a locomotive burning oil will last
longer than one in a coal burner If consideration is given to
the extra work possible to be obtained from the oil burner.
Oil requires from 20 to 30 per cent, more air per pound of
fuel than the average bituminous coal. There is a tendency
to restrict the air openings in draft pans of oil burners, and
it is generally the rule that with locomotives of the same
class in both oil- and coal-burner service, the oil burner will
have the smaller nozzle, indicating the necessity for main-
taining a higher front-end vacuum to draw in the necessary
amount of air to make the engine steam properly. This is
attended with the added difficulty thai the high velocitj ol the
entering air produces a more concentrated column or stream,
which is difficult to break up, requiring a heavy atomizer, the
use of which has its disadvantages.
There is a question whether the open furnace created by
the front-end burner arrangement is all that can be desired,
for it is true that the gases will follow the path of least
resistance and the velocity at the center of the combustion
space will be much higher than at the sides, this indicating
the necessity of some sort of a baffle to increase the velocity of
flow at the top and sides where the gases wipe the heat-
absorbing firebox sheets. It is also apparent that when the
flame path is surrounded by heat-absorbing surfaces to hasten
the process of diffusion and shorten flame length, the sub-
jecting of the gases to the presence of incandescent baffles is
desirable.
Aside from the two furnaces outlined there is in service on
one of the Southwestern railways, as well as on some Mexican
railways, the arrangement shown in Fig. 3. This differs from
the others in that it has a burner in both the front and the
rear of the draft pan, directed toward each other, the line of
flame of the front burner being slightly higher than that of
Burner ^_
Floor-
HoppeA\ \ftopper Poor
Fig. 2. Front-End Buhner Furnace
the rear. This furnace also has the advantage of the low
brickwork and large exposed heating surface. In fact, the
opposing burners do away with the necessity for a high flash-
wall under the door.
In the two last-named types it is the practice to keep the
brick low on the sides and expose all possible heating surface.
Firebrick for this service must be of good quality, as the
firebox temperatures range from 2500 to 2750 deg. F., which,
with the fluxing action of the salt and alkalies carried in
the oil, are severe on the furnace and cause it to give out
readily, making frequent renewals necessary. The proper
maintenance of brickwork is essential to good results, and the
possibility of the brickwork falling down in the path of the
flame must be avoided, as it usually results in an engine
failure.
The oil supply is carried in tanks built to fill the coal space
of the tender and piped from there through suitable connec-
tions to tlic burner, n is generally necessary to provide
means for heating the oil so as to insure a proper flow, as
gravltj i.s depended upon for the necessary pressure. This
heating Is also an aid in atomizing, and various means are
provided for the purpose. The original practice was to turn
steam directly into tin- oil, but aside from an emergency
feature, this lias been generally abandoned, as the accumula-
tion of condensation gave trouble in disposal, as well as by
getting into the oil line ami Interfering with tin- burner oper-
ation. The draining of tin- condensation from the tank was
Rear Damper
Fig. 3. Burner and Brick Arrangement in the
Hammel Furnace
always accompanied by some loss of oil, and the direct heating
often resulted in overheating the entire contents of the tank,
with the attending loss. An improvement was to place steam
coils in the space and heat indirectly. This had some advan-
tages, but it also caused trouble by overheating and by the
pipes leaking at the joints. It is probable that the box heater
is the most desirable arrangement. It is indirect in its action,
only heats a sufficient volume to insure a supply at the burner
and is not liable to cause trouble by allowing water to get
into the oil storage.
The oil-storage tanks are provided with suitable gages or
measuring devices to give a check on their contents at all
times. Means are also provided for cutting off the supply
of oil to the burner in case of accident, such as a wreck or
a break between the engine and tender. The supply of oil
is regulated by means of a suitable valve placed near the
burner and operated through connections by the fireman. In
some climates it is necessary to provide an auxiliary heater
in the pipe line to reheat the oil before it goes to the burner.
Such a heater should be used only when necessary, as exten-
sive heating tends to carbonize the fuel in the oil-supply line
and the burner.
Emphasis should be placed on the fact that the oil fireman
is an important factor in the success of the operation of oil-
burning locomotives. He must intelligently follow every
movement of the engineer that demands regulation of the
fire. He has two gages to guide him — the top of the stack
and the steam gage. That is. the proper steam pressure must
be maintained with the least possible smoke. A thin gray
color at the top of the stack is usually indicative of proper
combustion.
Given a modern locomotive with a furnace designed along
the lines indicated, with equipment in proper adjustment and
an intelligent engine crew, the result should be of as high an
order as is so far attainable with steam-operated motive
V
The twentieth annual convention of the New York State
Association; N. A. S. E„ was held June 11 and 12 at Auburn.
Upward of fifty delegates were In attendance at the business
sessions, which were held in Woodmen's Hall. The first floor
of this building was arranged for the use of exhibitors. The
convention was called to order Friday morninc: by F. J De-
Witt, chairman of the local committee. He introduced City
902
POWEE
Vol. 41, No. 26
Attorney William S. Elder, who welcomed the delegates in the
absence of Mayor Charles W. Brister. State-President Fred-
erick Felderman responded to this address of welcome. The
next speaker was Charles G. Adams, secretary of the Auburn
Chamber of Commerce, who gave a description of the manu-
facturing- resources of the city. National Vice-President Wal-
ter Damon, of Buffalo, dwelt briefly on the aims and principles
of the association. He was followed by Past-Xational-Presi-
dent Reynolds, of New Jersey, who outlined the aims and
and David Larkin. chaplain. William Bedard was chosen to
succeeded himself as state deputy.
The exhibitors were as follows:
Albany Lubricating Co.
Amer. Steam Gage & Valve Co.
Anderson Co.. V. D.
Auburn Woolen Co.
Burg & Hill
Clapp Mfg. Co.
Home Rubber Co.
International Harvester Co.
Interstate Machine Co.
Johns-Manville Co., H. W.
Keystone Lubricating Co.
Lunkenheimer Co.
Delegates to New York State X. A. S E. Convention, in Front of Auburn State Prison
plans of "The National Engineer." State-President Felderman
then called the business meeting to order and announced the
various committee appointments.
A feature of the convention was a luncheon given to the
delegates and guests at the Osbourne House, through the
courtesy of the Mcintosh & Seymour Corporation. Afterward,
special cars conveyed the party to an inspection of the com-
pany's plant. The entertainment program also included an
illustrated lecture on oil and steam engines, given under the
auspices of the Mcintosh & Seymour Corporation: an inspec-
tion of the Auburn prison: a trip to the plant of the Empire
Gas & Electric Co., and auto rides for the ladies to points
of interest in the city.
A pleasant surprise to State-President Felderman was the
presentation of a handsome clock. A silver service tray was
given to his wife. Past-National-President Reynolds made the
presentation addresses. A memorial service for members who
had passed away during the past year was conducted by
Vernon N. Tergin, pastor of Calvary Presbyterian Church. At
the closing session Niagara Falls was chosen for the June,
1916, meeting. The state officers unanimously elected were:
William H. Aydelotte. of Niagara Falls, president: William
Downey, New York City, vice-president; William Roberts,
Yonkers, secretary; William Downes. New York City, treas-
urer; Joseph C. Putrich, conductor; George Ely, doorkeeper;
Mcintosh & Seymour Corp.
McLeod & Henry Co.
"National Engineer"
New Birdsall Co.
Otis Elevator Co.
Peerless Rubber Mfg. Co.
"Power"
Quaker City Rubber Co.
Roebling Sons Co., John A.
Smith & Pearson
Wadsworth. David & Son
Woodruff & Murphy.
Columbian Rope Co.
Crandall Packing Co.
Cross, Orrin C.
Cuddy & Geherin
Dearborn Chemical Co.
Dunn McCarthy Co.
Eccles Co., Richard
Engineering Supply Co.
Garlock Packing Co.
Garrett Coal Co.
Henry & Allen
Herron Hardware Co.
To conserve and continue the work done by Frederick W.
Taylor, the initial steps have been taken to found an or-
ganization to be known as the Frederick W. Taylor Coopera-
tors. In harmony with Mrs. Frederick W. Taylor's request,
James M. Dodge. Carl G. Barth, Morris L. Cooke and H. K.
Hathaway have taken the initiative and have issued a pre-
liminary letter stating the purpose of the organization. This
is to gather books, data and other material that would be
of use in a biography or for a memorial to Mr. Taylor, and
to provide for the continuation and extension of the Taylor
System of Management.
June 29, 1915
P 0 W E B
903
^r Admiral IsIhieiFW©od Des\d alt 9!
Benjamin Franklin Isherwood, engineer-in-chief of the
United States Navy during the Civil War and one of the
founders of the experimental theory of the steam engine,
died at his late residence in New York on June 19, in his
93d year. Born Oct. 6, 1S22, in New York City, he was a
great-grandson of a distinguished French military engineer,
Captain Du Clos. an officer on General Lafayette's staff in
the American Revolution. His early schooling was received
at the Albany Academy, where he studied natural philosophy
under Joseph Henry, after which he entered the employ oi
the Utica & Schenectady R.R., and later went to work on
the construction of the Croton aqueduct, on its completion
entering the service of the Erie R.R.
His entry into governmental service was under the
Lighthouse Board, where he seems to have performed work
of responsibility, for he was sent to
France to superintend the construc-
tion of some lighthouse lenses from
designs by himself. The steam-en-
gineering corps of the Navy was
meanwhile being organized by-
Charles H. Haswell, and Isherwood
was one of its earliest appointees,
being made first-assistant engineer,
and in 1848 was promoted to chief
engineer. Meantime the Mexican
War had been fought and he had
been an active participant on ship-
board; in fact, he was in every
naval action. He served on the
"Princeton," the first American
screw steam vessel, and later on
the "Spitfire." After the war he
cruised for three years in the "San
Jacinto," attached to the Asiatic
squadron.
One of the earlier performances
that brought Isherwood profession-
ally into notice was the design of
alterations for the engines of the
"Allegheny," 1S51-52. He arranged
the cylinders with a back-acting
motion in a manner which antici-
pated the type of engine afterward
bearing his name. The device showed
his mechanical ingenuity, although
the vessel as a whole was not a
success, and the experience taught
him in future designing to provide engine frames strong
enough to allow for weakness in the hull, a point which was
especially important when so many old vessels, many of which
were of light construction, had to be equipped during the
Civil War.
At the outbreak of the Civil War, Isherwood, although
some distance from the top of the list, was appointed to the
responsible position of engineer-in-chief of the war navy.
His appointment was dated Mar. 26, 1SG1. Not only did he
evince a dependable zeal for the Federal Government — which,
at a time when so many officers were going over to the
Confederacy or wavering in their allegiance, was no small
recommendation — but his professional qualifications were of
an exceptionally high order. For many years past he had
given his attention to systematic experimental research in
steam engineering, where he had done splendid work and
was probably the leader in America. The result of some of
these researches had been given to the public, notably in
1859, in a book entitled "Engineering Precedents," which
embodied his studies on the indicated power of engines,
frictional losses, power expended in actual propulsion of
vessels, etc. It is interesting to note that this book had the
first published indicator diagrams reproduced from actual
engines.
The task confronting Isherwood upon his appointment
was that of evoking a new and large navy out of nothing,
or next to nothing, in a short period. At the beginning of
the war the Government had only 69 vessels of all classes,
34 of them being sailing ships. By the end of the year 1861
it had improvised a navy amounting to 211 vessels, with
2301 guns and 20,000 men, which by the close of the war
had grown to 600 vessels of all classes.
One of the reasons for Isherwood's success was his strong
common sense, which was shown particularly in the design
Late Beak Admiral Isherwood
of the machinery built during the Civil War. Although the
adoption of a low ratio of expansion, and hence high mean
pressure, gave him small engines, the machinery was very
heavy. Designers working 30 or 40 years later, with im-
proved mat. -rials, have criticized this machinery, forgetting
one point with which Isherwood was supreme — this ma-
chinery was desig I tor war vessels, and it was absolutely
essential that it should not break down. The enormous ex-
pansion of the Navj led to the employment of large numbers
of patriotic but comparatively unskilled engineers. To have
intrusted delicate machinery to such men would have been
to run the risk of disaster. For the same reason, such ex-
pansion as was obtained depended only on the ordinary
Stephenson link, there being no separate and complicated
cutoff gears. But almost incredible was his ability to find
lime for the continuation of elab-
orate scientific investigations, to
profit by his unrivaled opportunity
for practical experiments, and even
during those busy years to publish
in huge volumes the results of his
researches.
In 1S63, when swift cruisers were
coming into- use, speed qualities re-
ceived especial attention. About
this time the rivalry in design be-
tween Isherwood and Ericsson was
carried out In the construction of
twin 4200-ton ships — the "Mada-
waska," with engines of Ericsson's
design, and the "Wampanoag," fitted
with Isherwood engines. The latter
had a pair of 100-in. cylinders with
4-ft. stroke and wooden gears, to
make 2.04 revolutions of the screw
for each double stroke of the piston.
Here, again, we note an illustra-
tion of Isherwood's sound common
sense. The machinery, which for
the time was extremely powerful,
was to go into a relatively light
wooden hull, and to have used
direct-driven engines would have
racked the hull. Ericsson's engines
were of the same size, but directly
connected to the shaft. In the trials
the "Wampanoag" made a wonderful
record for those days, attaining an
average speed of over 16 knots in a winter's sea, and during
several periods of a six-hour run over 17 knots were ob-
tained. The "Madawaska" also was capable of high speed,
but she could not stand the racking. This did not disprove
Ericsson's essential correctness in having, long ago, come
out as an advocate of direct, ungeared connections, but the
abnormal narrowness of the vessel created a special condi-
tion to which the design of her machinery was not adapted.
Not for 21 years was the "Wampanoag's" speed again reached
in the Navy.
In the early personnel struggles, Isherwood was a cham-
pion of his corps. He contended that naval engineers required
not only technical training, but theoretical education, and
should possess official rank, which has since become estab-
lished. It is largely to him that we may credit the Con-
gressional Act of 1S64 providing for the education of midship-
men as naval constructors or steam engineers.
After serving as engineer-in-chief for eight years, cover-
ing the stressful period of the war, Isherwood was succeeded,
in 1S69, by James W. King. The remainder of his term in
the service was largely taken up with special duties. His
experiments with screw propellers at Mare Island are scarcely
less famous than the expansion tests and those on the econ-
omy of compound engines.
By operation of law he retired In 1884 with the relative
rank of commodore (since raised to rear-admiral). More
than a quarter of a century of life was still in store for him,
however. He made his home in New York City, interested
and active in research, scientific and literary work, and in-
dulging in extensive tours abroad. The published output of
his life in books and papers has been considerable. His
"Experimental Researches in Steam Engineering," compiled
In Civil-War times, has become a classic, and, as the late Dr.
Thurston pointed out, "his conclusions, once ridiculed, are
now the basis of the modern engineer's practice."
904
PO WEE
Vol. 41, No. 26
Illustrated, S pp., 6x9 in. Bulletin No. 153. Centrifugal pumps
for house service. Illustrated, S pp., 6x9 in. Bulletin No. 300.
Triplex pumps. Illustrated, 4 pp., 6x9 in.
BEN B. LAMPREY
Ben B. Lamprey died June 14, at the age of 68, in West-
field, Mass. He was born in Moultonborough, N. H., and in
his younger days conducted a hotel and ran a steamboat line
at Lake Winnepesaukee. He was the inventor of the Lamprey
arch plate and of other devices for low-pressure steam boilers,
and was the owner of the Lamprey Boiler, Furnace & Pro-
tective Co., of Boston.
M. A. Hudson, formerly vice-president and general manager
of the J. E. Lonergan Co., Philadelphia, Penn., has become
general manager of the Central Western branch, United Roof-
ing & Manufacturing Co., with headquarters in the Marquette
Building, Chicago.
J. N. Oswald, formerly a member of the engineering de-
partment of the Pittsburgh Ry. Co., has been appointed
mechanical engineer with the Vacuum Oil Co., Pittsburgh. He
was the first erecting engineer of the Nagle Corliss Engine
Works, of Erie, Penn., and was for 11 years at the head of
the power department of the Gould Coupler Co., Depew, N. T.
Mr. Oswald is president of Pittsburgh No. 3, N. A. S. E.
Osborn Monnett, after a creditable service of four years as
chief smoke inspector of the City of Chicago, has become as-
sociated with the Institute of Thermal Research of the
American Radiator Co., Chicago. In this connection he will
offer his services to smoke commissions and smoke inspectors
throughout the United States and in every way possible co-
operate with those interested in the movement to standardize
smoke ordinances and to abate the smoke evil in the heating
field. Mr. Monnett was an associate editor of "Power" before
taking the Chicago position.
EHGHMEERIIMG AFFAHRJ
The Canadian Association of Stationary Engineers will
hold its annual convention July 20-22, at Hamilton, Ont. It
is expected that the attendance of delegates and the dis-
play of exhibits will be larger than ever before. The local
committee, with the assistance of the officers of the Exhibi-
tors' Association, has arranged an enjoyable entertainment
program.
The New England States Association of the National As-
sociation of Stationary Engineers will hold its annual con-
vention in Holyoke, Mass., July 7-10. The Nonotuck Hotel
has been selected as the headquarters. The meetings of the
delegates will be held in the large hall of the Temperance
Building, and the City Hall has been secured for the exhibits.
An enjoyable program of entertainment has been arranged
by the local engineers' committee and by a committee of the
supplymen.
International Nickel Co., 43 Exchange Place, New York.
Catalog. Moncl metal. 12 pp., 4x8% in.
General Electric Co., Schenectady, X. Y. Bulletin No.
42.552. Motor generator sets. Illustrated, 2S pp., SxlOK in.
Chicago Pneumatic Tool Co., Fisher Building, Chicago, 111.
Bulletin 34-X. Class A-G "Giant" gas and gasoline engines.
Illustrated, S pp., 6x9 in.
Fisher Governor Co., Marshalltown, Iowa. Bulletin Cata-
log. Pump governors, reducing valves, pressure regulators,
etc. Illustrated, JUsSU in.
Ingersoll-Rand Co., 11 Broadway, New York. Form No.
3031. Ingersoll-Rogler Class FK-1 air compressors. Illus-
trated, 24 pp., 6x9 in. Form No. 4034. Leyner-Ingersoll water
drill. Illustrated, 4 pp., 6x9 in.
A. S. Cameron Steam Pump Works, 11 Broadway, New
York. Bulletin No. lot. Station and sinking pumps. Illus-
trated, 36 pp., 6x9 in. Bulletin No. 150. Double suction volute
centrifugal pumps. Illustrated, 16 pp., 6x9 in. Bulletin No.
l.il. Turbine centrifugal pumps. Illustrated, 20 pp., 6x9 in.
Bulletin No. 152. Single suction volute centrifugal pumps.
ATLANTIC COAST STATES
Bids will be received until 2:30 p.m. June 29, by E. S. El-
wood, Secy., State Hospital Comn., Capitol, Albany," N. Y., for
the construction and equipment of a power house and electri-
cal work at the Middletown State Homeopathic Hospital, Mid-
dletown, N. Y.
The Board of Education, Paterson, N. J., has engaged Lewis
E. Eaton, Consult. Engr., to prepare plans for a light and
power plant for the High School. An appropriation of $5000
has been made for the work.
SOUTHERN STATES
An election will be held June 29 in Orangeburg, S. C, to
vote for a bond issue of $15,000, the proceeds of which will be
used for the improvement of the municipal electric-light plant.
Edward Howes is City Engr.
The City Council of Cordele, Ga., will engage an engineer
to prepare plans and estimates for the construc.'ion and oper-
ation of a municipal electric-light plant in Corjele.
At a recent election the citizens of Toccoa, Ga. voted in
favor of issuing $35,000 in bonds to be used for the installa-
tion of a municipal electric-light plan'
CENTRAL, STATES
The Falls I ubber Co., Cuyahoga Falls, Ohio, is having
plans prepared '"or a one-story brick and steel power house
for its plant. Ernest McGeorge, Leader-News Bldg., Cleve-
land, is Engr.
It is reported that the Ohio Public Utilities Commission has
authorized the Dayton Power & Light Co., Dayton, Ohio, to
issue $172,000 in additional capital stock, the proceeds of
which will be used to increase the output of tht c~)t from
20.000 to 30,000 hp.
The City Council of Wellsville, Ohio, will soon adve?t.se for
bids for the sale of $60,000 in bonds, the proceeds of which
will be used for the construction of a municipal electric-light
plant.
It is reported that bids will be received until July 12 by
the Wernette-Bradfield-Meade Co., Arch, and Engr., Grand
Rapids, Mich., for the construction of a power plant for the
Imperial Furniture Co., Grand Rapids.
It is reported that the City of Petoskey, Mich., is preparing
to rebuild the municipal electric-light plant. J. W. Lovelace
is Mgr. and Supt.
The Town of Three Rivers, Mich., is reported to have $50,-
000 in bonds available for the construction of a municipal
electric-light and water-works plant. George Champe, Toledo,
Ohio, is Consult. Engr..
WEST OF THE MISSISSIPPI
It is reported that the Des Moines Electric Co., Des Moines,
Iowa, contemplates the construction of a 44.000-volt transmis-
sion line to Knoxville, Iowa, to furnish energy to the Knox-
ville Electric Co.
(Official) — Bids will be received until July 1 by the City
Council of Davenport, Neb., for the installation of an electric-
light plant to cost about $5000. Charles F. Sturtevant, Hold-
rege, Neb., is Consult. Engr. Noted June 22.
The City Council of Holdrege, Neb., has extended the fran-
chise of the Holdrege Lighting Co. for a period of 25 years.
The company has agreed to reduce its rates for lighting and
will make various improvements in its plant.
The Union Light, Heat & Power Co., Fargo, N. D., is en-
larging and improving its power station, and will install new
equipment, including two 1500-kw. steam turbines, two water-
tube boilers, a three-unit motor generator set of 600 hp., boiler
feed pump, exciters, switchboard, etc. M. L. Hibbard is Mgr.
(Official) — Bids will be received until 2 p.m., July 15, by
John A. Ryan, Secy., Bd. of Pub. Wks., Chillicothe, Mo., for
installing in the municipal electric-light plant the following
equipment: One 375-kw., three-phase, 60-cyele, 2300-volt gen-
erator, direct-connected to a steam engine or steam turbine
to operate condenser, with separate exciter, switchboard panel
and instruments, power circuit panel, etc.; one 500-g.p.m.
motor-driven centrifugal pump, for use with condenser, and
one 12-in. barometric condenser, one 12-in. horizontal oil sep-
arator, and the necessary pipe, valve fittings, etc., required
to install the pump and condenser. Harper & Stiles, Grand
Ave. Temple, Kansas City, is Consult. Engr.
The Missouri Public Utilities Co., Cape Girardeau, Mo., has
been granted a franchise to construct a transmission line from
its power station at Charleston, Mo., to East Prairie, a dis-
tance of 12 miles, to furnish electrical service to the latter
place.
It is reported that H. W. Wright and Thomas Peterson,
both of Peoria, 111., are considering plans for the installation
of an electric-light and power plant in Fulton, Mo. Energy
for the operation of the plant will be obtained from the Keo-
kuk Electric Co.. Keokuk, Iowa.
Henry S. Grimes has made application to the City Council
of Lowry City, Mo., for a franchise to install an electric-light
plant in Lowry City.
It is reported that the Citv of Brownsville, Tex., is con-
sidering the sale of the municipal electric-light plant to a
company which will also take over the street-railway com-
pany and combine the two properties J. W. Davis is City
Engr.
BJN01NG SECT. JIM I2 ^
TJ
1
P7
V.41
Engin .
Power
^fJlTW STORAQt
PLEASE DO NOT REMOVE
CARDS OR SLIPS FROM THIS POCKET
UNIVERSITY OF TORONTO LIBRARY
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Books to Borrow
Open Library
TV News
Understanding 9/11