Decreased gas consumption of a fluidized bed furnace

Abstract

The feasibility of utilizing a closed circulatory system to generate gases for a fluidized bed furnace was investigated with the primary concentrations of both economizing on the raw materials used for producing furnace atmospheres and decreasing the air pollution caused by exhaust gases. Air humidified with water vapor was first introduced into a charcoal furnace for causing a reaction with hot charcoal to form a carburizing atmosphere. This atmosphere was then introduced into a fluidized bed furnace to carburize steels. The exhaust gases from the fluidized bed furnace were recycled by repassing them through the hot charcoal layer in the charcoal furnace with a gas pump. The charcoal furnace and the fluidized bed furnace formed a closed circulatory system during the carburization of steels. Experiments were performed with various parameters of this system, including content of water vapor in the humid air, temperature of the charcoal, rate of recirculation of the atmosphere,etc. The effect of each parameter on the carburizing behavior in the fluidized bed furnace was investigated on the basis of the rate of carburization and the carbon potential of the atmosphere. The feasibility of applying this system to a fluidized bed furnace was assessed from the aspects of the fluidization of A1₂O₃ powder, the result of carburizing steel, and the rate of consumption of charcoal. The closed system employed in generating atmosphere was demonstrated by the experimental results to have enabled the fluidized bed furnace to operate normally and to have significantly decreased both the consumption rate of charcoal and the environmental pollution.