BOILEB No. 32. 141 



Dimensions of Boiler No. 32. 



Diameter of shell, , . 54 in. 



Length between heads and length of tubes, . . . 15 ft. 



Number of tubes ( collective ) 3 inches outside diameter, . 160 



Area of water-heating surface, . . . . . 1,980 sq. ft. 



Area of steam-heating surface, 120 sq. ft. 



Area of total heating surface, 2,100 sq. ft. 



Area of grate surface, . . . . . . . .49.3 sq. ft. 



Area through tubes, G.O sq. ft. 



Area through flue, . . G sq. ft. 



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



Distance of grate to shell, . 19 in. 



Distance of flat bridge wall to shell, ..... 5 in. 

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



Ratio of grate surface to tube area, . . . . . 7.5 to 1 



Results of Tests, Boiler No. 32. ( Average of two ). 



Test No. 68. 

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



Duration, . . . . . . . . . . .11.5 hrs. 



Coal consumed, dry (including wood equivalent ), . 6,288 Ibs. 



Percentage of ash, ........ 6.5 per cent. 



Water evaporated, . . 58,993 Ibs. 



Coal per hour, 546.8 Ibs. 



Coal per hour per square foot of grate, . . . . 11.1 Ibs. 



Water per hour, ........ 5,134.2 Ibs. 



Water per hour per square foot of water-heating surface, 2.6 Ibs. 



Horse-power developed, 177.6 H. P. 



Boiler pressure, ........ 65 Ibs. 



Temperature of feed-water, 57 cleg. 



Temperature of escaping gases, ..... 408 deg. 



Draught suction, 0.35 in. 



Percentage of moisture in steam, . . . . . 2.2 per cent. 



Water per pound of coal, . . .''".. . . 9.39 Ibs. 



Water per pound of coal from and at 212 degrees, . 11.20 Ibs. 



Water per pound of combustible from and at 212 degrees, . 11.98 Ibs. 



The test on Boiler No. 32 shows the performance of an ordi- 

 nary tubular boiler worked with Cumberland coal. The per- 

 centage of ash is small and indicates a good quality of fuel. 

 The rate of combustion is moderately high, and the tempera- 

 ture of the escaping gases is not excessive for bituminous coal. 

 These conditions are favorable for economy, and the resulting 

 evaporation bears out the expectations which they justify. 

 The effect of the steam heating surface in this boiler does not 

 appear to have been sufficient to thoroughly dry the steam. 



