A CFD analysis of the influence of plenum configurations on gas distribution in a fluidized bed

Abstract

Fluidized beds are widely used in many industries. The fluidization quality of these units is strongly related to the characteristics of the plenum and distributor (grid). In this work, the effect of different plenum geometries, and gas entrance sizes and locations on the velocity profile above the distributor was analyzed by Computational Fluid Dynamics (CFD). The results showed that flow uniformity above the distributor improved with an increase in the gas inlet diameter and the plenum height. Channeling was observed for the bottom central inlet. Addition-ally, simulations for plenum heights predicted by one of the frequently used correlations (Litz correlation) were also carried out and showed, especially for a bot-tom central gas inlet, a poor quality flow distribution. This behavior indicated that Litz correlation tends to underestimate the plenum height for obtaining a uni-form flow downstream the distributor.