Discrete particle simulation of solid flow in a model blast furnace

Abstract

This paper reports a numerical study of solid flow in a model blast furnace under simplified conditions by means of discrete particle simulation (DPS). The applicability of the proposed DPS approach is validated from its good agreement with the experiment in terms of solid flow patterns. It is shown that the DPS is able to generate a stagnant zone without any need for any arbitrary treatment, and capture the main features of solid flow within the furnace at a microscopic level. The results confirm that the solid flow in a blast furnace can be divided into four different flow regions. However, the flow is strongly influenced by the front and rear walls in a 2D slot model furnace whereas the predicted stagnant zone decreases significantly with wall sliding friction. In a 3D model with periodic boundary conditions incorporated, a smaller stagnant zone is obtained. The effects of solid flow rate, particle properties such as sliding and rolling friction coefficients on the solid flow are also investigated. The results are analysed in terms of solid flow patterns, solid velocity field, porosity distribution and normal force structure. The implication to blast furnace operation is discussed. © 2005 ISIJ.