Abstract
A cold model experiment and a theoretical study concerning the two phase flow of gas and solid in a packed bed were performed and the following results were obtained.
1) Pressure drop and powder hold-up increased with the decrease in gas velosity when gas velocity was below a certain value.
2) A theoretical model to predict the pressure drop and the powder hold-up was developed under the assumption that the interaction force between gas and powders was expressed by the Ergun type gas flow resistance.
3) On the basis of this model, the aggravation of gas flow resistance of the blast furnace under the conditions of reduced production rate was explained to be caused by the accumulation of powders in the lower part, above tuyere level, of the furnace.
