Gas-solid flow in cyclones: The Eulerian-Eulerian approach

A computational fluid dynamic model was used to simulate the diluted gas-solid flow in a conventional; cyclone. Most of the studies published in the literature present the Lagrangian model for solid phase. In this work, the model is based on the Eulerian approach for both phases considering the two fluid assumption in a 3-D symmetrical domain. The mathematical model was completed using of the k-epsilon turbulence model which was used to predict the eddy viscosity for axial and radial components of the Reynolds stress of the gas phase. Also, for the tangential velocity of the gas phase, the Prandtl's mixture length theory was used to predict the tangential components of the Reynolds stress, and a wall function was used to predict the swirling near the wall. This turbulence model presents an anisotropic behaviour of the Reynolds stress on the gas phase. The solid phase flow was considered to be an inviscid flow, and only a drag force model was used for gas-solid interaction. Two physical situations were simulated to test the model proposed: one was clean air flow, and the other was air and spherical particles of glass in a diluted flow. The primary information obtained from the model was the influence of the solid phase on the gas phase. It was the possible to predict the reduction of the tangential velocity peak responsible for the pressure drop reduction due to the particle presence. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.