Abstract
As part of an investigation of the factors affecting the performance of furnaces, the heat-absorption efficiency of the furnace of a pulverized-coal-fired dry-bottom steam boiler was determined from the sensible heat in the gases at the furnace outlet. The sensible heat was determined from the temperature of the gases, which was measured by traversing the furnace outlet with a high-velocity thermocouple, and from the quantity of gas leaving the furnace, which was computed from the composition of the gas and the rate of fuel firing. Data are given for the distribution at the furnace outlet of excess air, gas temperature, and mass flow. The effect on furnace heat-absorption efficiency is shown for variations in (a) the heat available in the furnace, (b) the excess air, (c) the angle of inclination of the burners, and (d) the condition of the furnace with respect to deposits of ash and slag on the heat-absorbing surfaces. The data of this investigation were correlated by a modified form of the Hudson-Orrok equation, which relates empirically the furnace heat-absorption efficiency to the weight of wet gases at the furnace outlet, per unit heat available in the furnace, and the heat available in the furnace per square foot of projected radiant heating surface.
