Study of flow through a packed bed using discrete element method and computational fluid dynamics

Abstract

Packed beds find wide applications in chemical industries. In this paper, a Discrete Element Method (DEM) - Computational Fluid Dynamics (CFD) approach has been adopted to predict the flow profile in the bed for different diameter of the bed/diameter of the particle. The randomly packed bed was created using the DEM technique. The radial voidage of the bed was calculated using the Monte Carlo integration method. The radial voidage showed an oscillating pattern up to approximately 4-5 particle diameter from the wall, which was validated with the experimental data reported by several researchers. The flow studies through these packed beds were carried using single-phase laminar flow model. The flow followed a similar oscillating pattern as the radial voidage. The numerical results were validated with experimental data. Preliminary studies to predict the residence time distribution has also been carried out using the multi-species transport model, which was also experimentally validated. The study suggests that DEM and CFD simulation can predict the flow behaviour as well as Residence Time Distribution (RTD) in a packed bed quite satisfactorily without the need to carry out experiments, which would be environmental friendly. (c) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.