A Theoretical Analysis on Gas Flow and Heat Transfer in Packed Beds with Fused and Unfused Layers

Abstract

A mathematical formulation was proposed for the simulation on simultaneous gas flow and heat transfer in the packed bed with fused and unfused layers for providing the mechanism of heat transfer in the lower part of the blast furnace. The model consisted of heat balances on gas and solids and of the multidimensional Ergun equation as the equation of motion. Therefore, it can predict distributions for mass velocity of gas and for temperatures of gas and solids. Numerical computation was performed for various degree of fusion and also for different inlet flow rate of gas.
The computed results show that fused layer is essentially heated up by heat exchange between gas and solid for the low degree of fusion, whereas, for the case of the high degree of fusion, it is done principally by heat conduction from the surrounding unfused layer where preferential flow of gas would present and, as the results, temperature would be increased rapidly.