Three-dimensional gas–liquid flow simulation of a rotating packed bed using Eulerian porous media models

Abstract

The rotating packed bed (RPB) is a typical equipment in chemical process intensification technology due to its excellent mass transfer performance. In this paper, a three-dimensional full-scale model was established based on the Eulerian two-fluid method to study the gas–liquid two-phase flow in RPBs. Three different single-phase wire screen packing pressure drop models coupled with the interfacial area model were used to construct resistance calculation methods for porous media, respectively. The results show that simulation deviations of the liquid holdup and the pressure drop of the m-K model range from 0.92 % to 27.61 % and 1.63 % to 34.59 %, respectively. In addition, the simulation accuracy of the liquid holdup of three models was obviously influenced by the rotational speed (N). The m-K model has the highest prediction accuracy at N = 500 ∼ 1500 rpm. At N = 2000 ∼ 2500 rpm, the B model has the highest prediction accuracy. Characteristics of gas–liquid flow under different conditions and nozzle designs were obtained. In particular, the impact of different nozzle designs on liquid distribution has been investigated using a new method based on user-defined functions (UDFs). A more homogeneous distribution of liquid within the packing can be achieved by increasing nozzle height, decreasing nozzle size, and increasing the number of nozzles.