CFD Simulations of Gas Fluidized Beds Using Alternative Eulerian-Eulerian Modelling Approaches

Abstract

A commercially available Computational Fluid-Dynamics code, CFX-4, has been chosen to carry out computer simulations of gas fluidized beds. In this study, the Eulerian-Eulerian granular kinetic model, which is a standard option of the code, has been used. Fluid-bed simulations of Geldart Group B materials have been performed using the granular kinetic model, spanning three hydrodynamic regimes: bubbling, slugging and turbulent fluidization. Furthermore, an alternative Eulerian-Eulerian model, the so-called "particle-bed model", has been implemented for the first time within a commercial code, and results are presented from simulations of the bubbling and slugging fluidization of a Geldart Group B material, and for the homogeneous fluidization of a Group A material. A numerical procedure has been developed to allow for a tight control of the fluid-bed voidage at maximum packing during the simulations with the particle-bed model. Results show that both the granular kinetic model approach and the particle-bed model are able to describe significant aspects of the investigated fluidization regimes.