Feasibility assessment of an endothermic gas generator-built-in fluidized bed furnace

Abstract

Advantages of the fluidized bed furnace are claimed to be the rapid heating rate, fast atmosphere purging speed and good temperature uniformity. However, it consumes enormous amounts of fuel gas and the atmosphere composition in the bed is unstable because of direct boosting of fuel gas and air from the bottom of the bed. As a result, the effective treating zone of the bed is too narrow for applying the fluidized bed to high-quality carburization or bright heat treatment of steel. An endothermic gas generator-built-in fluidized bed furnace constructed with a catalytic zone in the lower part of the furnace was studied in this research. The fuel gas and air were stoichiometrically mixed and endothermically reacted in the catalytic zone before the product gases were guided upwards into the bed so as to acquire a stable endothermic atmosphere. The results showed that it substantially enlarged the effective working zone of the furnace, which made the precise carburization and/or bright heat treatment of steels possible in the fluidizing bed furnace. In order to simulate the high humidity season of the year in subtropical settings, the incoming air for reforming the endothermic atmosphere was further moistened according to the humidity of the rainy season and the results were compared with those of the theoretical computer calculations.