Based on the previous research on the blast furnace simulation, a gas flow simulation model for direct reduction shaft furnaces which are free of a coke layer and operated by a fixed charging cylinder system was developed. In order to derive the calculation formula, experiments were conducted using a burden distribution model for the fixed charging cylinder system mentioned above to analyze the characteristic features of the furnace. Radial distributions of particle diameter and void fraction were considered for the estimation of gas velocity distribution in this model. The results obtained by this simulation system agreed well with those acquired in actual operation of a 500 t/d furnace.
