Abstract
Model experiments at low temperature were carried out for the simultaneous gas flow and heat transfer in the packed beds which have the double structure of fused and unfused layers providing different resistances to gas flow in order to elucidate the mechanism of heat transfer in the fused zone in the blast furnace.
Temperature changes were observed at various positions in the bed with unfused layer of spherical alumina and fused layer which was made of polystyrene particles.
In the case of the low degree of fusion, the fused layer is considered to be heated up principally by heat exchange between gas and solid, because the preheated gas can flow through the fused layer. On the other hand, for the high degree of fusion, temperature decreases from the boundary between fused and unfused layers to the core of the fused layer. This temperature gradient allows conductive heat transfer from the alumina layer to the fused layer.
The experimental results show good agreement with the values predicted from the mathematical model which has been developed in the previous paper.
Furthermore, the effective thermal conductivity of the fused layer was measured with various degree of fusion. Results obtained was expressed by an empirical equation with respect to the degree of fusion. The equation was used for the prediction of temperature changes in the bed by the mathematical model.
