Where W = per cent of moisture in coal,
t = the temperature of air in the boiler room,
T = temperature of the flue gases,
.47 = the specific heat of superheated steam at the atmospheric
pressure and at the flue gas temperature,
(212-t) = B. t. u. necessary to heat one pound of water from the
temperature of the boiler room to 212 degrees,
970.4 = B. t. u. necessary to evaporate one pound of water at 212
degrees to steam at atmospheric pressure,
.47(T-212) = B. t. u. necessary to superheat one pound of steam at
atmospheric pressure from 212 degrees to temperature T.
[Illustration: Portion of 15,000 Horse-power Installation of Babcock &
Wilcox Boilers, Equipped with Babcock & Wilcox Chain Grate Stokers at
the Northumberland, Pa., Plant of the Atlas Portland Cement Co. This
Company Operates a Total of 24,000 Horse Power of Babcock & Wilcox
Boilers in its Various Plants]
(B) Loss due to heat carried away in the steam produced by the burning
of the hydrogen component of the fuel. In burning, one pound of hydrogen
unites with 8 pounds of oxygen to form 9 pounds of steam. Following the
reasoning of item (A), therefore, this loss will be: