Portion of 3600 Horse-power Installation of Babcock & Wilcox Boilers, Equipped with Babcock & Wilcox Chain Grate Stokers at the Loomis Street Plant of the Peoples Gas Light & Coke Co., Chicago, Ill. This Company has Installed 7780 Horse Power of Babcock & Wilcox Boilers
FOOTNOTES
[54] To determine the portion of the fuel which is actually burned, the weight of ashes should be computed from the total weight of coal burned and the coal and ash analyses in order to allow for any ash that may be blown away with the flue gases. In many cases the ash so computed is considerably higher than that found in the test.
[55] As distinguished from the efficiency of boiler, furnace and grate.
[56] To obtain the efficiency of the boiler as an absorber of the heat contained in the hot gases, this should be the heat generated per pound of combustible corrected so that any heat lost through incomplete combustion will not be charged to the boiler. This, however, does not eliminate the furnace as the presence of excess air in the gases lowers the efficiency and the ability to run without excess air depends on the design and operation of the furnace. The efficiency based on the total heat value per pound of combustible is, however, ordinarily taken as the efficiency of the boiler notwithstanding the fact that it necessarily involves the furnace.
[57] See pages [280] and [281].
[58] Where the horse power of marine boilers is stated, it generally refers to and is synonymous with the horse power developed by the engines which they serve.
[59] In other countries, boilers are ordinarily rated not in horse power but by specifying the quantity of water they are capable of evaporating from and at 212 degrees or under other conditions.
[60] See equivalent evaporation from and at 212 degrees, page [116].