| | | | | | | | | | Water Evaporated | | | | | | | | | per Hour from | | | | | | | | | from and at | Pounds | 18310| 27855| 22639| 40375| 21720| 42863| | 212 Degrees | | | | | | | | | | | | | | | | | | Evaporation from | | | | | | | | | and at 212 | | | | | | | | | Degrees per | Pounds | 15.96| 15.16| 15.73| 14.07| 15.47| 13.34| | Pound of Oil | | | | | | | | | | | | | | | | | | Per Cent of | | | | | | | | | Rated Capacity | Pounds | 113.6| 172.9| 108.6| 193.8| 104.9| 207.1| | Developed | | | | | | | | | | | | | | | | | | B. t. u. per | | | | | | | | | Pound of Oil | B. t. u. | 18626| 18518| 18326| 18096| 18600| 18600| | | | | | | | | | | Efficiency | Per Cent | 83.15| 79.46| 83.29| 76.02| 80.70| 69.6 | |__________________|__________|______|______|______|______|______|______| Burning Oil in Connection with Other Fuels--Considerable attention has been recently given to the burning of oil in connection with other fuels, and a combination of this sort may be advisable either with the view to increasing the boiler capacity to assist over peak loads, or to keep the boiler in operation where there is the possibility of a temporary failure of the primary fuel. It would appear from experiments that such a combination gives satisfactory results from the standpoint of both capacity and efficiency, if the two fuels are burned in separate furnaces. Satisfactory results cannot ordinarily be obtained when it is attempted to burn oil fuel in the same furnace as the primary fuel, as it is practically impossible to admit the proper amount of air for combustion for each of the two fuels simultaneously. The Babcock & Wilcox boiler lends itself readily to a double furnace arrangement and Fig. 30 shows an installation where oil fuel is burned as an auxiliary to wood. [Illustration: Fig. 30. Babcock & Wilcox Boiler Set with Combination Oil and Wood-burning Furnace]