______________________________________________________________________
|Number| | | | Rated |
| of | Name and Location | Kind of Coal | Kind of | Horse |
| Test | of Plant | | Furnace |Power of|
| | | | | Boiler |
| | | | | |
|______|___________________________|________________|_________|________|
| |Susquehanna Coal Co., |No. 1 Anthracite|Hand | |
| 1 |Shenandoah, Pa. |Buckwheat |Fired | 300 |
|______|___________________________|________________|_________|________|
| |Balbach Smelting & |No. 2 Buckwheat |Wilkenson| |
| 2 |Refining Co., Newark, N. J.|and Bird's-eye | Stoker | 218 |
|______|___________________________|________________|_________|________|
| |H. R. Worthington, |No. 2 Anthracite|Hand | |
| 3 |Harrison N. J. |Buckwheat |Fired | 300 |
|______|___________________________|________________|_________|________|
| |Raymond Street Jail, |Anthracite Pea |Hand | |
| 4 |Brooklyn, N. Y. | |Fired | 155 |
|______|___________________________|________________|_________|________|
| |R. H. Macy & Co., |No. 3 Anthracite|Hand | |
| 5 |New York, N. Y. |Buckwheat |Fired | 293 |
|______|___________________________|________________|_________|________|
| |National Bureau of |Anthracite Egg |Hand | |
| 6 |Standards, Washington, D.C.| |Fired | 119 |
|______|___________________________|________________|_________|________|
| |Fred. Loeser & Co., |No. 1 Anthracite|Hand | |
| 7 |Brooklyn, N. Y. |Buckwheat |Fired | 300 |
|______|___________________________|________________|_________|________|
| |New York Edison Co., |No. 2 Anthracite|Hand | |
| 8 |New York City |Buckwheat |Fired | 374 |
|______|___________________________|________________|_________|________|
| |Sewage Pumping Station, |Hocking Valley |Hand | |
| 9 |Cleveland, O. |Lump, O. |Fired | 150 |
|______|___________________________|________________|_________|________|
| |Scioto River Pumping Sta., |Hocking Valley, |Hand | |
| 10 |Cleveland, O. |O. |Fired | 300 |
|______|___________________________|________________|_________|________|
| |Consolidated Gas & Electric|Somerset, Pa. |Hand | |
| 11 |Co., Baltimore, Md. | |Fired | 640 |
|______|___________________________|________________|_________|________|
| |Consolidated Gas & Electric|Somerset, Pa. |Hand | |
| 12 |Co., Baltimore, Md. | |Fired | 640 |
|______|___________________________|________________|_________|________|
| |Merrimac Mfg. Co., |Georges Creek, |Hand | |
| 13 |Lowell, Mass. |Md. |Fired | 321 |
|______|___________________________|________________|_________|________|
| |Great West'n Sugar Co., |Lafayette, Col.,|HandFired| |
| 14 |Ft. Collins, Col. |Mine Run |Extension| 351 |
|______|___________________________|________________|_________|________|
| |Baltimore Sewage Pumping |New River |Hand | |
| 15 | Station | |Fired | 266 |
|______|___________________________|________________|_________|________|
| |Tennessee State Prison, |Brushy Mountain,|Hand | |
| 16 |Nashville, Tenn. |Tenn. |Fired | 300 |
|______|___________________________|________________|_________|________|
| |Pine Bluff Corporation, |Arkansas Slack |Hand | |
| 17 |Pine Bluff, Ark. | |Fired | 298 |
|______|___________________________|________________|_________|________|
| |Pub. Serv. Corporation |Valley, Pa., |Roney | |
| 18 |of N. J., Hoboken |Mine Run |Stoker | 520 |
|______|___________________________|________________|_________|________|
| |Pub. Serv. Corporation |Valley, Pa., |Roney | |
| 19 |of N. J., Hoboken |Mine Run |Stoker | 520 |
|______|___________________________|________________|_________|________|
| |Frick Building, |Pittsburgh Nut |American | |
| 20 |Pittsburgh, Pa. |and Slack |Stoker | 300 |
|______|___________________________|________________|_________|________|
| |New York Edison Co., |Loyal Hanna, Pa.|Taylor | |
| 21 |New York City | |Stoker | 604 |
|______|___________________________|________________|_________|________|
| |City of Columbus, O., |Hocking Valley, |Detroit | |
| 22 |Dept. Lighting |O. |Stoker | 300 |
|______|___________________________|________________|_________|________|
| |Edison Elec. Illum. Co., |New River |Murphy | |
| 23 |Boston, Mass. | |Stoker | 508 |
|______|___________________________|________________|_________|________|
| |Colorado Springs & |Pike View, Col.,|Green Chn| |
| 24 |Interurban Ry., Col. |Mine Run |Grate | 400 |
|______|___________________________|________________|_________|________|
| |Pub. Serv. Corporation |Lancashire, Pa. |B&W.Chain| |
| 25 |of N. J., Marion | |Grate | 600 |
|______|___________________________|________________|_________|________|
| |Pub. Serv. Corporation |Lancashire, Pa. |B&W.Chain| |
| 26 |of N. J., Marion | |Grate | 600 |
|______|___________________________|________________|_________|________|
| |Erie County Electric Co., |Mercer County, |B&W.Chain| |
| 27 |Erie, Pa. |Pa. |Grate | 508 |
|______|___________________________|________________|_________|________|
| |Union Elec. Lt. & Pr. Co., |Mascouth, Ill. |B&W.Chain| |
| 28 |St. Louis, Mo. | |Grate | 508 |
|______|___________________________|________________|_________|________|
| |Union Elec. Lt. & Pr. Co., |St. Clair |B&W.Chain| |
| 29 |St. Louis, Mo. |County, Ill. |Grate | 508 |
|______|___________________________|________________|_________|________|
| |Commonwealth Edison Co., |Carterville, |B&W.Chain| |
| 30 |Chicago, Ill. |Ill., Screenings|Grate | 508 |
|______|___________________________|________________|_________|________|
________________________________________________________________
|Number|Grate |Dura-|Steam |Temper-|Degrees|Factor| Draft |
| of |Surf. | tion|Pres. | ature | Super | of | In | At |
| Test |Square|Test | By | Water | -heat |Evapo-|Furnace|Boiler|
| | Feet |Hours|Gauge |Degrees|Degrees|ration|Inches |Damper|
| | | |Pounds| Fahr. | Fahr. | |Upr/Lwr|Inches|
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 1 | 84 | 8 | 68 | 53.9 | |1.1965| +.41 | .21 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | +.65 | |
| 2 | 51.6 | 7 | 136.3| 203 | 150 |1.1480| .47 | .56 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 3 | 67.6 | 8 | 139 | 139.6 | 139 |1.1984| .70 | .96 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 4 | 40 | 8 | 110.2| 137 | |1.1185| .33 | .43 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 5 | 59.5 | 10 | 133.2| 75.2 | |1.1849| .19 | .40 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 6 | 26.5 | 18 | 132.1| 70.5 | |1.1897| .33 | |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | +.51 | |
| 7 | 48.9 | 7 | 101. | 121.3 | |1.1333| -.20 | .30 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 8 | 59.5 | 6 | 191.8| 88.3 | |1.1771| .50 | |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 9 | 27 | 24 | 156.3| 58 | |1.2051| .10 | .24 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 10 | | 24 | 145 | 75 | |1.1866| .26 | .46 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 11 | 118 | 8 | 170 | 186.1 | 66.7 |1.1162| .34 | .42 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 12 | 118 | 7.92| 173 | 180.2 | 75.2 |1.1276| .44 | .58 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 13 | 52 | 24 | 75 | 53.3 | |1.1987| .25 | .35 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 14 | 59.5 | 8 | 105 | 35.8 | |1.2219| .17 | .38 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 15 | 59.5 | 24 | 170.1| 133 | |1.1293| .12 | .43 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 16 | 51.3 | 10 | 105 | 75.1 | |1.1814| .21 | .42 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 17 | 59.5 | 8 | 149.2| 71 | |1.1910| .35 | .59 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 18 | 103.2| 10 | 133.2| 65.3 | 65.9 |1.2346| .05 | .49 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 19 | 103.2| 9 | 139 | 64 | 80.2 |1.2358| .18 | .57 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 20 | 53 | 9 | 125 | 76.6 | |1.1826| +1.64 | .64 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 21 | 75 | 8 | 198.5| 165.1 | 104 |1.1662| +3.05 | .60 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 22 | | 9 | 140 | 67 | 180 |1.2942| .22 | .35 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 23 | 90 |16.25| 199 | 48.4 | 136.5 |1.2996| .23 | 1.27 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 24 | 103 | 8 | 129 | 56 | |1.2002| .23 | .30 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | +.52 | |
| 25 | 132 | 8 | 200 | 57.2 | 280.4 |1.3909| +.19 | .52 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | +.15 | |
| 26 | 132 | 8 | 199 | 60.7 | 171.0 |1.3191| .04 | .52 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 27 | 90 | 8 | 120 | 69.9 | |1.1888| .31 | .58 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 28 | 103.5| 8 | 180 | 46 | 113 |1.2871| .62 | 1.24 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 29 | 103.5| 8 | 183 | 53.1 | 104 |1.2725| .60 | 1.26 |
|______|______|_____|______|_______|_______|______|_______|______|
| | | | | | | | | |
| 30 | 90 | 7 | 184 | 127.1 | 180 |1.2393| .68 | 1.15 |
|______|______|_____|______|_______|_______|______|_______|______|
______________________________________________________________
|Number|Temper-| Coal |
| of | ature | Total | Moist-| Total |Ash and| Total |DryCoal|
| Test |FlueGas|Weight:| ure | dry | Refuse|Combus-|/sq.ft.|
| |Degrees| Fired | Per | Coal | Per | tible | Grate |
| | Fahr. |Pounds | Cent | Pounds| Cent | Pounds|/Hr.Lb.|
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 1 | | 11670 | 4.45 | 11151 | 26.05 | 8248 | 16.6 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 2 | 487 | 8800 | 7.62 | 8129 | 29.82 | 5705 | 19.71 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 3 | 559 | 10799 | 6.42 | 10106 | 20.02 | 8081 | 21.77 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 4 | 427 | 5088 | 4.00 | 4884 | 19.35 | 3939 | 15.26 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 5 | 414 | 9440 | 2.14 | 9238 | 11.19 | 8204 | 15.52 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 6 | 410 | 8555 | 3.62 | 8245 | 15.73 | 6948 | 17.28 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 7 | 480 | 7130 | 7.38 | 6604 | 18.35 | 5392 | 19.29 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 8 | 449 | 7500 | 2.70 | 7298 | 27.94 | 5259 | 14.73 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 9 | 410 | 15087 | 7.50 | 13956 | 11.30 | 12379 | 21.5 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 10 | 503 | 29528 | 7.72 | 27248 | | | 24.7 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 11 | 487 | 20400 | 2.84 | 19821 | 7.83 | 18269 | 21.00 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 12 | 494 | 21332 | 2.29 | 20843 | 8.23 | 19127 | 22.31 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 13 | 516 | 24584 | 4.29 | 23529 | 7.63 | 21883 | 18.85 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 14 | 523 | 15540 | 18.64 | 12643 | | | 28.59 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 15 | 474 | 18330 | 2.03 | 17958 | 16.36 | 16096 | 12.57 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 16 | 536 | 12243 | 2.14 | 11981 | | | 23.40 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 17 | 534 | 10500 | 3.04 | 10181 | | | 21.40 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 18 | 458 | 18600 | 3.40 | 17968 | 18.38 | 14665 | 17.41 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 19 | 609 | 23400 | 2.56 | 22801 | 16.89 | 18951 | 24.55 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 20 | 518 | 10500 | 1.83 | 10308 | 12.22 | 9048 | 21.56 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 21 | 536 | 25296 | 2.20 | 24736 | | | 41.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 22 | 511 | 14263 | 8.63 | 13032 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 23 | 560 | 39670 | 4.22 | 37996 | 4.32 | 36355 | 25.98 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 24 | 538 | 23000 | 23.73 | 17542 | | | 21.36 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 25 | 590 | 32205 | 4.03 | 30907 | 15.65 | 26070 | 29.26 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 26 | 529 | 24243 | 4.09 | 23251 | 12.33 | 20385 | 22.01 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 27 | 533 | 22328 | 4.42 | 21341 | 16.88 | 17739 | 29.64 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 28 | 523 | 32163 | 13.74 | 27744 | | | 33.50 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 29 | 567 | 36150 | 14.62 | 30865 | | | 37.28 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 30 | | 30610 | 11.12 | 27206 | 14.70 | 23198 | 43.20 |
|______|_______|_______|_______|_______|_______|_______|_______|
______________________________________________________________
|Number| Water | | Flue Gas Analysis |
| of |Actual | Equiv.|ditto /|% Rated|CO_{2} | O | CO |
| Test |Evapor-|Evap. @|sq.ft. |Cap'ty.| Per | Per | Per |
| | ation |>=212° |Heating|Develpd| Cent | Cent | Cent |
| |/Hr.Lb.|/Hr.Lb.|Surface|PerCent| | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 1 | 10268 | 12286 | 4.10 | 118.7 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 2 | 8246 | 9466 | 4.34 | 125.7 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 3 | 9145 | 10959 | 3.65 | 105.9 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 4 | 5006 | 5599 | 3.61 | 104.7 | 12.26 | 7.88 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 5 | 7434 | 8809 | 3.06 | 87.2 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 6 | 2903 | 3454 | 2.91 | 84.4 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 7 | 7464 | 8459 | 2.82 | 81.7 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 8 | 9164 | 10787 | 2.88 | 83.5 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 9 | 4374 | 5271 | 3.51 | 101.8 | 11.7 | 7.3 | 0.07 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 10 | 8688 | 10309 | 3.44 | 99.6 | 12.9 | 5.0 | 0.2 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 11 | 24036 | 26829 | 4.19 | 121.5 | 12.5 | 6.4 | 0.5 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 12 | 25313 | 28544 | 4.46 | 129.3 | 13.3 | 5.1 | 0.5 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 13 | 9168 | 10990 | 3.42 | 99.3 | 9.6 | 8.8 | 0.4 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 14 | 11202 | 13689 | 3.91 | 113.5 | 9.1 | 9.9 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 15 | 7565 | 8543 | 3.21 | 93.1 | 10.71 | 9.10 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 16 | 9512 | 11237 | 3.74 | 108.6 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 17 | 9257 | 11025 | 3.70 | 107.2 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 18 | 15887 | 19614 | 3.77 | 108.7 | 11.7 | 7.7 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 19 | 21320 | 26347 | 5.06 | 146.7 | 11.9 | 7.8 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 20 | 9976 | 11978 | 3.93 | 112.0 | 11.3 | 7.5 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 21 | 28451 | 33066 | 5.47 | 158.6 | 12.3 | 6.4 | 0.7 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 22 | 10467 | 13526 | 4.51 | 130.7 | 11.9 | 7.2 | 0.04 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 23 | 20700 | 26902 | 5.30 | 153.5 | 11.1 | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 24 | 14650 | 17583 | 4.40 | 127.4 | | | |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 25 | 28906 | 40205 | 6.70 | 194.2 | 10.5 | 8.3 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 26 | 23074 | 30437 | 5.07 | 147.0 | 10.1 | 9.0 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 27 | 20759 | 24678 | 4.85 | 140.8 | 10.1 | 9.1 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 28 | 21998 | 28314 | 5.67 | 161.5 | 8.7 | 10.6 | 0.0 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 29 | 24386 | 31031 | 6.11 | 177.1 | 8.9 | 10.7 | 0.2 |
|______|_______|_______|_______|_______|_______|_______|_______|
| | | | | | | | |
| 30 | 30505 | 37805 | 7.43 | 215.7 | 10.4 | 9.4 | 0.2 |
|______|_______|_______|_______|_______|_______|_______|_______|
_______________________________________________________
|Number| Proximate Analysis Dry Coal | Equiv.|Combnd.|
| of |Volatl.| Fixed | Ash |B.t.u./|Evap. @|Efficy.|
| Test |Matter |Carbon | Per | Pound |>=212°/|Boiler |
| | Per | Per | Cent | Dry | Pound |& Grate|
| | Cent | Cent | | Coal |DryCoal|PerCent|
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 1 | | | 26.05 | 11913 | 8.81 | 71.8 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 2 | | | | 11104 | 8.15 | 72.1 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 3 | 5.55 | 80.60 | 13.87 | 12300 | 8.67 | 68.4 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 4 | 7.74 | 77.48 | 14.78 | 12851 | 9.17 | 69.2 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 5 | | | | 13138 | 9.53 | 69.6 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 6 | 6.13 | 84.86 | 9.01 | 13454 | 9.57 | 69.0 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 7 | | | | 12224 | 8.97 | 71.2 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 8 | 0.55 | 86.73 | 12.72 | 12642 | 8.87 | 68.1 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 9 | 39.01 | 48.08 | 12.91 | 12292 | 9.06 | 71.5 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 10 | 38.33 | 46.71 | 14.96 | 12284 | 9.08 | 71.7 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 11 | 19.86 | 73.02 | 7.12 | 14602 | 10.83 | 72.0 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 12 | 20.24 | 72.26 | 7.50 | 14381 | 10.84 | 73.2 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 13 | | | | 14955 | 11.21 | 72.7 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 14 | 39.60 | 54.46 | 5.94 | 11585 | 8.66 | 72.5 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 15 | 17.44 | 76.42 | 5.84 | 15379 | 11.42 | 72.1 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 16 | 33.40 | 54.73 | 11.87 | 12751 | 9.38 | 71.4 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 17 | 15.42 | 62.48 | 22.10 | 12060 | 8.66 | 69.6 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 18 | 14.99 | 75.13 | 9.88 | 14152 | 10.92 | 74.88 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 19 | 14.40 | 74.33 | 11.27 | 14022 | 10.40 | 71.97 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 20 | 32.44 | 56.71 | 10.85 | 13510 | 10.30 | 74.6 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 21 | 19.02 | 72.09 | 8.89 | 14105 | 10.69 | 73.5 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 22 | 32.11 | 53.93 | 13.96 | 12435 | 9.41 | 73.4 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 23 | 19.66 | 75.41 | 4.93 | 14910 | 11.51 | 74.9 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 24 | 43.57 | 46.22 | 10.21 | 11160 | 8.02 | 69.7 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 25 | 22.84 | 69.91 | 7.25 | 13840 | 10.41 | 72.6 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 26 | 32.36 | 60.67 | 6.97 | 14027 | 10.47 | 72.1 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 27 | 33.26 | 54.03 | 12.71 | 12742 | 9.25 | 70.4 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 28 | 28.96 | 46.88 | 24.16 | 10576 | 8.16 | 74.9 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 29 | 36.50 | 41.20 | 22.30 | 10849 | 8.04 | 71.9 |
|______|_______|_______|_______|_______|_______|_______|
| | | | | | | |
| 30 | | | 10.24 | 13126 | 9.73 | 71.9 |
|______|_______|_______|_______|_______|_______|_______|
[Illustration: 15400 Horse-power Installation of Babcock & Wilcox
Boilers and Superheaters, Equipped with Babcock & Wilcox Chain Grate
Stokers at the Plant of the Twin City Rapid Transit Co., Minneapolis,
Minn.]
This increase in the efficiency of the boiler alone with the decrease in
the rate at which it is operated, will hold to a point where the
radiation of heat from the boiler setting is proportionately large
enough to be a governing factor in the total amount of heat absorbed.
The second reason given above for a decrease of boiler efficiency with
increase of capacity, viz., the effect of radiant heat, is to a greater
extent than the first reason dependent upon a constant furnace
temperature. Any increase in this temperature will affect enormously the
amount of heat absorbed by radiation, as this absorption will vary as
the fourth power of the temperature of the radiating body. In this way
it is seen that but a slight increase in furnace temperature will be
necessary to bring the proportional part, due to absorption by
radiation, of the total heat absorbed, up to its proper proportion at
the higher ratings. This factor of furnace temperature more properly
belongs to the consideration of furnace efficiency than of boiler
efficiency. There is a point, however, in any furnace above which the
combustion will be so poor as to actually reduce the furnace temperature
and, therefore, the proportion of heat absorbed through radiation by a
given amount of exposed heating surface.
Since it is thus true that the efficiency of the boiler considered alone
will increase with a decreased capacity, it is evident that if the
furnace conditions are constant regardless of the load, that the
combined efficiency of boiler and furnace will also decrease with
increasing loads. This fact was clearly proven in the tests of the
boilers at the Detroit Edison Company.[74] The furnace arrangement of
these boilers and the great care with which the tests were run made it
possible to secure uniformly good furnace conditions irrespective of
load, and here the maximum efficiency was obtained at a point somewhat
less than the rated capacity of the boilers.
In some cases, however, and especially in the ordinary operation of the
plant, the furnace efficiency will, up to a certain point, increase with
an increase in power. This increase in furnace efficiency is ordinarily
at a greater rate as the capacity increases than is the decrease in
boiler efficiency, with the result that the combined efficiency of
boiler and furnace will to a certain point increase with an increase in
capacity. This makes the ordinary point of maximum combined efficiency
somewhat above the rated capacity of the boiler and in many cases the
combined efficiency will be practically a constant over a considerable
range of ratings. The features limiting the establishing of the point of
maximum efficiency at a high rating are the same as those limiting the
amount of grate surface that can be installed under a boiler. The
relative efficiency of different combinations of boilers and furnaces at
different ratings depends so largely upon the furnace conditions that
what might hold for one combination would not for another.
In view of the above, it is impossible to make a statement of the
efficiency at different capacities of a boiler and furnace which will
hold for any and all conditions. Fig. 40 shows in a general form the
relation of efficiency to capacity. This curve has been plotted from a
great number of tests, all of which were corrected to bring them to
approximately the same conditions. The curve represents test conditions.
The efficiencies represented are those which may be secured only under
such conditions. The general direction of the curve, however, will be
found to hold approximately correct for operating conditions when used
only as a guide to what may be expected.
[Graph: Combined Efficiency of Boiler and Furnace Per Cent
against Per Cent of Boiler's Rated Capacity Developed
Fig. 40. Approximate Variation of Efficiency with Capacity under Test
Conditions]
Economical Loads--With the effect of capacity on economy in mind, the
question arises as to what constitutes the economical load to be
carried. In figuring on the economical load for an individual plant, the
broader economy is to be considered, that in which, against the boiler
efficiency, there is to be weighed the plant first cost, returns on such
investment, fuel cost, labor, capacity, etc., etc. This matter has been
widely discussed, but unfortunately such discussion has been largely
limited to central power station practice. The power generated in such
stations, while representing an enormous total, is by no means the
larger proportion of the total power generated throughout the country.
The factors determining the economic load for the small plant, however,
are the same as in a large, and in general the statements made relative
to the question are equally applicable.
The economical rating at which a boiler plant should be run is dependent
solely upon the load to be carried by that individual plant and the
nature of such load. The economical load for each individual plant can
be determined only from the careful study of each individual set of
conditions or by actual trial.
The controlling factor in the cost of the plant, regardless of the
nature of the load, is the capacity to carry the maximum peak load that
may be thrown on the plant under any conditions.
While load conditions, do, as stated, vary in every individual plant, in
a broad sense all loads may be grouped in three classes: 1st, the
approximately constant 24-hour load; 2nd, the steady 10 or 12-hour load
usually with a noonday period of no load; 3rd, the 24-hour variable
load, found in central station practice. The economical load at which
the boiler may be run will vary with these groups:
1st. For a constant load, 24 hours in the day, it will be found in most
cases that, when all features are considered, the most economical load
or that at which a given amount of steam can be produced the most
cheaply will be considerably over the rated horse power of the boiler.
How much above the rated capacity this most economic load will be, is
dependent largely upon the cost of coal at the plant, but under ordinary
conditions, the point of maximum economy will probably be found to be
somewhere between 25 and 50 per cent above the rated capacity of the
boilers. The capital investment must be weighed against the coal saving
through increased thermal efficiency and the labor account, which
increases with the number of units, must be given proper consideration.
When the question is considered in connection with a plant already
installed, the conditions are different from where a new plant is
contemplated. In an old plant, where there are enough boilers to operate
at low rates of capacity, the capital investment leads to a fixed
charge, and it will be found that the most economical load at which
boilers may be operated will be lower than where a new plant is under
consideration.
2nd. For a load of 10 or 12 hours a day, either an approximately steady
load or one in which there is a peak, where the boilers have been banked
over night, the capacity at which they may be run with the best economy
will be found to be higher than for uniform 24-hour load conditions.
This is obviously due to original investment, that is, a given amount of
invested capital can be made to earn a larger return through the higher
overload, and this will hold true to a point where the added return more
than offsets the decrease in actual boiler efficiency. Here again the
determining factors of what is the economical load are the fuel and
labor cost balanced against the thermal efficiency. With a load of this
character, there is another factor which may affect the economical plant
operating load. This is from the viewpoint of spare boilers. That such
added capacity in the way of spares is necessary is unquestionable.
Since they must be installed, therefore, their presence leads to a fixed
charge and it is probable that for the plant, as a whole, the economical
load will be somewhat lower than if the boilers were considered only as
spares. That is, it may be found best to operate these spares as a part
of the regular equipment at all times except when other boilers are off
for cleaning and repairs, thus reducing the load on the individual
boilers and increasing the efficiency. Under such conditions, the added
boiler units can be considered as spares only during such time as some
of the boilers are not in operation.
Due to the operating difficulties that may be encountered at the higher
overloads, it will ordinarily be found that the most economical ratings
at which to run boilers for such load conditions will be between 150 and
175 per cent of rating. Here again the maximum capacity at which the
boilers may be run for the best plant economy is limited by the point at
which the efficiency drops below what is warranted in view of the first
cost of the apparatus.
3rd. The 24-hour variable load. This is a class of load carried by the
central power station, a load constant only in the sense that there are
no periods of no load and which varies widely with different portions of
the 24 hours. With such a load it is particularly difficult to make any
assertion as to the point of maximum economy that will hold for any
station, as this point is more than with any other class of load
dependent upon the factors entering into the operation of each
individual plant.
The methods of handling a load of this description vary probably more
than with any other kind of load, dependent upon fuel, labor, type of
stoker, flexibility of combined furnace and boiler etc., etc.
In general, under ordinary conditions such as appear in city central
power station work where the maximum peaks occur but a few times a year,
the plant should be made of such size as to enable it to carry these
peaks at the maximum possible overload on the boilers, sufficient margin
of course being allowed for insurance against interruption of service.
With the boilers operating at this maximum overload through the peaks a
large sacrifice in boiler efficiency is allowable, provided that by such
sacrifice the overload expected is secured.
[Illustration: Portion of 4890 Horse-power Installation of Babcock &
Wilcox Boilers at the Billings Sugar Co., Billings, Mont. 694 Horse
Power of these Boilers are Equipped with Babcock and Wilcox Chain Grate
Stokers]
Some methods of handling a load of this nature are given below:
Certain plant operating conditions make it advisable, from the
standpoint of plant economy, to carry whatever load is on the plant at
any time on only such boilers as will furnish the power required when
operating at ratings of, say, 150 to 200 per cent. That is, all boilers
which are in service are operated at such ratings at all times, the
variation in load being taken care of by the number of boilers on the
line. Banked boilers are cut in to take care of increasing loads and
peaks and placed again on bank when the peak periods have passed. It is
probable that this method of handling central station load is to-day the
most generally used.
Other conditions of operation make it advisable to carry the load on a
definite number of boiler units, operating these at slightly below their
rated capacity during periods of light or low loads and securing the
overload capacity during peaks by operating the same boilers at high
ratings. In this method there are no boilers kept on banked fires, the
spares being spares in every sense of the word.
A third method of handling widely varying loads which is coming somewhat
into vogue is that of considering the plant as divided, one part to take
care of what may be considered the constant plant load, the other to
take care of the floating or variable load. With such a method that
portion of the plant carrying the steady load is so proportioned that
the boilers may be operated at the point of maximum efficiency, this
point being raised to a maximum through the use of economizers and the
general installation of any apparatus leading to such results. The
variable load will be carried on the remaining boilers of the plant
under either of the methods just given, that is, at the high ratings of
all boilers in service and banking others, or a variable capacity from
all boilers in service.
The opportunity is again taken to indicate the very general character of
any statements made relative to the economical load for any plant and to
emphasize the fact that each individual case must be considered
independently, with the conditions of operations applicable thereto.
With a thorough understanding of the meaning of boiler efficiency and
capacity and their relation to each other, it is possible to consider
more specifically the selection of boilers.
The foremost consideration is, without question, the adaptability of the
design selected to the nature of the work to be done. An installation
which is only temporary in its nature would obviously not warrant the
first cost that a permanent plant would. If boilers are to carry an
intermittent and suddenly fluctuating load, such as a hoisting load or a
reversing mill load, a design would have to be selected that would not
tend to prime with the fluctuations and sudden demand for steam. A
boiler that would give the highest possible efficiency with fuel of one
description, would not of necessity give such efficiency with a
different fuel. A boiler of a certain design which might be good for
small plant practice would not, because of the limitations in
practicable size of units, be suitable for large installations. A
discussion of the relative value of designs can be carried on almost
indefinitely but enough has been said to indicate that a given design
will not serve satisfactorily under all conditions and that the
adaptability to the service required will be dependent upon the fuel
available, the class of labor procurable, the feed water that must be
used, the nature of the plant's load, the size of the plant and the
first cost warranted by the service the boiler is to fulfill.