BOILER No. 67. 223 



Boiler No. 67 is a water tube boiler, having the general 

 features shown in the cut of Boiler No. 66. It is of compara- 

 tively small size, having only 42 tubes, and it is connected 

 with a chimney which is deficient in draught power. 



Dimensions of Boiler No. 67. 



Number of tubes 4 inches outside diameter, ... 42 



Length of tubes, 16 ft. 



Area of heating surface, 839 sq. ft. 



Area of grate, , 23 sq. ft- 



Area through flue, . . . . . . . . 5.3 sq. ft. 



Width of air spaces and metal bars in grates, Air 5-16 in., metal 1-2 in. 



Height of chimney, . . . . . . . . 60 ft. 



Ratio of heating surface to grate surface, .... 36.5 to 1 



Ratio of grate surface to flue area, 4.3 to 1 



Results of Test, Boiler No. 67. 



Test No. 132. 



Manner of start and stop, Ordinary. 



Kind of run Continuous. 



Duration, 8.3 hrs. 



Coal consumed, dry ( including wood equivalent ), . 1,576 Ibs. 



Percentage of ash 14.7 per cent. 



Water evaporated, ........ 11,292 Ibs. 



Coal per hour, 189.2 Ibs. 



Coal per hour per square foot of grate, .... 8.2 Ibs. 



Water per hour, . . . . . . . . 1,355.5 Ibs. 



Water per hour per square foot of heating surface, . 1.6 Ibs. 



Horse-power developed, 47.2 H. P. 



Boiler pressure, 104 Ibs. 



Temperature of feed-water, . . . . . . 68 cleg. 



Temperature of escaping gases, 360 deg. 



Draught suction, ....... 0*2 in. 



Water per pound of coal, 7.16 Ibs. 



Water per pound of coal from and at 212 degrees, . 8.52 Ibs. 



Water per pound of combustible from and at 212 degrees, . 10.00 Ibs. 



The test on Boiler No. 67 shows the performance of a small 

 water tube boiler, using one of the low grades of anthracite 

 coal. The result obtained, which was 10 pounds of water 

 from and at 212. per pound of combustible, is somewhat 

 inferior to good practice. Test No. 47, made with a similar 

 coal on a horizontal tubular boiler, gave 10.72 pounds and 

 Test No. 58, 10.78 pounds. In the case under consideration 

 the boiler had plenty of heating surface, and the heat was well 



