220 BOILER TESTS. 



Dimensions of Boiler No. 65. 

 Number of tubes ( collective ) 4 inches outside diameter, . 256 



Length of tubes, 18 ft. 



Diameter of drums (four), 36 in. 



Mean length of drums, . . . . . . 17 ft. 6 in. 



Area of heating surface, 5,614 sq. ft. 



Area of grate surface, 141.7 sq. ft. 



Area through flue, 18.5 sq. ft. 



Width of air spaces and metal bars in grates, Air 5-16 in., metal 7-16 in. 

 Ratio of heating surface to grate surface, . . . . 40 to 1 

 Ratio of grate surface to flue area, ..... 7.2 to 1 



Results of Test, Boiler No. 65. 



Test No. 130. 

 Manner of start and stop and kind of run, .... Ordinary. 



Duration, 11 hrs. 



Coal consumed, dry ( including wood equivalent ), . 19,043 Ibs. 



Percentage of ash, 17.4 per cent. 



Water evaporated, 161,656 Ibs. 



Coal per hour, 1,731.2 Ibs. 



Coal per hour per square foot of grate, ..... 12.2 Ibs. 



Water per hour, 14,696 Ibs. 



Water per hour per square foot of heating surface, . . 2.5 Ibs. 



Horse-power developed, ....... 474.4 H. P. 



Boiler pressure, , . 101.2 Ibs. 



Temperature of feed-water leaving heater, . . . 145.3 deg. 



Temperature of escaping gases, 353 deg. 



Draught suction, 0.29 in. 



Percentage of moisture in steam 0.6 per cent. 



Water per pound of coal, ....... 8.49 Ibs. 



Water per pound of coal from and at 212 degrees, . . 9.45 Ibs. 



Water per pound of combustible from and at 212 degrees, . 11.44 Ibs. 

 NOTE. The coal when fired contained 5 per cent, of moisture. 



The test on Boiler No. 65 shows the performance of a water 

 tube boiler with one of the small grades of anthracite coal. 

 The conditions with respect to capacity, rate of combustion 

 and temperature of escaping gases, are all favorable, and an 

 exceedingly high evaporative result, based on combustible, is 

 secured. A subsequent test was made when only three boilers 

 were in use, developing about the same total power. The 

 rate of combustion was 15.7 pounds, the percentage of ash 

 15.8 per cent., the temperature of the feed water 156.7 

 degrees, and the temperature of the escaping gases 389 



