An anisotropic turbulent mass transfer model for simulation of pilot-scale and industrial-scale packed columns for chemical absorption

Abstract

An anisotropic turbulent mass transfer model, namely the Reynolds mass flux model (RMF), for simulating the chemical absorption process in packed column is introduced by the use of combined computational methodology. With the present model, the concentration and temperature as well as velocity distributions can be simultaneously obtained. The feature of the proposed model is that the modeled Reynolds mass flux equation is adopted to close the turbulent mass transfer equation so that the Boussinesq’s postulation is abandoned and consequently the anisotropy of turbulent mass diffusion can be characterized. The present model is accompanied by the formulations of computational fluid dynamics (CFD) and computational heat transfer (CHT). In mathematical expression of CFD and CHT, the Reynolds stress and Reynolds heat flux equations are used to close the turbulent momentum and heat transfer equations. The simulated results are validated with experimental data for pilot-scale and industrial-scale packed columns and satisfactory agreement is found between them. Furthermore, the Reynolds mass flux and the anisotropic turbulent mass diffusion are characterized and discussed.