Analysis of single phase Newtonian and non-Newtonian velocity distribution in periodic packed beds

Abstract

A three dimensional computational fluid dynamics (CFD) model based on unit cell concept is presented to analyze the hydrodynamics of periodic operation in packed bed reactors (PBRs). Flow profiles, mass flux distribution, and pressure drop results are studied for various split ratios with Newtonian and non-Newtonian power law liquids. Two different structured packing arrangements are considered to understand the effect of particle orientation on the flow maldistribution during fast mode of min–max periodic operation. For a fixed operating condition, better radial liquid distribution is observed for periodic operation with higher split ratio in face centered cubic (FCC) geometry, however, at lower split ratio, well irrigation of the bed is obtained for modified simple cubic (SC) geometry. For both the geometries, shear thinning liquid imparts least maldistribution. Comparison of periodic operation results against continuous flow advocate benefits of the former in terms of liquid distribution in the bed irrespective of splits. This fundamental study essentially sets the foundation of modeling multiphase flow modulation in periodic PBRs.