98 BOILER TESTS, 



The tests on Boiler No. 11 had for an object the determina- 

 tion of the economy of crude petroleum, compared with 

 anthracite coal. On the test with petroleum the damper was 

 kept wide open, and the capacity of the boiler was regulated 

 by varying the quantity of oil consumed. On the test with 

 coal the damper was partially closed. During the oil test the 

 quantity of steam used by the burner amounted to 15 per cent, 

 of the total amount generated by the boiler, and the quantities 

 given in the Table are corrected for the steam thus used. 



The results of the tests show a higher evaporation per pound 

 of fuel in the case of oil than in the case of coal, the increase 

 being 34.2 per cent. The quantity of fuel required to evapo- 

 rate a given quantity of water say 30,000 pounds from 

 and at 212 degrees in the two cases, according to these results, 

 is 3,367 pounds or 1.5 tons of coal, and 2,509 pounds or 386 

 gallons of oil. The coal at $5 per ton costs $7.50. The price 

 of oil required to bring the cost of 386 gallons up to $7.50 is 

 1.9 cents per gallon. The employment of a liquid fuel serves 

 to reduce to a minimum the labor attending the firing and care 

 of a plant of boilers. A plant of 1,000 horse-power, in a mill 

 running 10 hours per day, requires two firemen for day run, 

 two helpers for wheeling coal, and one night hand for banking, 

 removing ashes, and preparing the morning fires. The use of 

 oil suitably arranged requires only one man, and dispenses 

 with the labor of the remaining four. The saving in cost of 

 labor thus realized represents about 10 per cent, of the cost of 

 the fuel, assuming that coal is $5 per ton and 12 tons of coal 

 are burned per day. This element in the problem should not 

 be disregarded when making a comparison of the relative 

 economy of the two kinds of fuel. In the case of these tests 

 it makes the price of oil for the plant noted 2.18 cents per 

 gallon to equal the performance of coal at $5 per ton. 



Boiler No. 12. 



Kind of boiler, Horizontal return tubular. 



Number used, One. 



Horse-power (basis 12 square feet), . . Eighty-seven. 



Age, ....,.. Eight months. 



