170 BOILEE TESTS. 



Boiler No. 45 is a double deck boiler similar in all features 

 except size to Boilers No. 41 and No. 42, and the manner in 

 which it is arranged and set is shown in the cuts of these 

 boilers. 



Dimensions of Boiler No. 45. 



Diameter of lower shell, . 66 in. 



Diameter of upper shell, . ... . . . . 36 in. 



Length of shells and tubes, 15 ft. 



Number of tubes 3 inches outside diameter, . . . 172 



Area of water-heating surface, ...... 2,235 sq. ft. 



Area of steam-heating surface, 70 sq. ft. 



Area through tubes, 7.1 sq. ft. 



Area of grate surface, ' 36.6 sq. ft. 



Width of air spaces and metal bars in grates, Air 5-8 in., metal 1-2 in. 



Eatio of water-heating surface to grate surface, . . . 60.9 to 1 



Ratio of steam-heating surface to grate surface, . . . 2 to 1 



Ratio of grate surface to tube area, . . . . . 5.2 to 1 



Results of Tests, Boiler No. 45. (Average of two.) 



Test No. 90. 

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



Duration, 11.7 hrs. 



Coal consumed ( including wood equivalent ), . . 6,237 Ibs. 



Percentage of ash, . . . . . . . . .8.1 per cent. 



Water evaporated, 56,388 Ibs. 



Coal per hour, 530.8 Ibs. 



Coal per hour per square foot of grate, .... 14.5 Ibs. 



Water per hour, 4,799 Ibs. 



Water per hour per square foot of water-heating surf ace, . 2.1 Ibs. 



Horse-power developed, 155.1 H. P. 



Boiler pressure, 79 Ibs. 



Temperature of feed water, 132 deg 



Temperature of escaping gases, . . . . . 373 deg- 



Percentage of moisture in steam, 0.3 per cent. 



Water per pound of coal, 9.04 Ibs. 



Water per pound of coal from and at 212 degrees, . . 9.76 Ibs. 



Water per pound of combustible from and at 212 degrees, . 11.00 Ibs. 



The tests on Boiler No. 45 were made with damper wide 

 open, and therefore under conditions of maximum capacity. 

 The chimney was of ample size, and its height was 70 feet. 

 The boiler power developed amounted to 155 horse power, or 

 a trifle more than the nominal capacity rated on 15 square feet 

 of heating surface per horse power. Although the boiler 



