Numerical simulation of counter-current flow field in the downcomer of a liquid-solid circulating fluidized bed  

作　　者：Abbas Dadashi Chao Zhang Jingxu(Jesse)Zhu 

机构地区：[1]Department of Mechanical and Materials Engineering,Western University [2]Department of Chemical and Biochemical Engineering,Western University

出　　处：《Particuology》2015年第4期48-54,共7页颗粒学报（英文版）

基　　金：supported by the Discovery Grant and Engage Grant from the Natural Sciences and Engineering Research Council of Canada(NSERC)

摘　　要：A comprehensive study on the hydrodynamics in the downcomer of a liquid-solid circulating fluidized bed （LSCFB） is crucial in the control and optimization of the extraction process using an ion exchange LSCFB. A computational fluid dynamics model is proposed in this study to simulate the counter-current two-phase flow in the downcomer of the LSCFB. The model is based on the Eulerian-Eulerian approach incorporating the kinetic theory of granular flow. The predicted results agree well with our earlier experimental data. Furthermore, it is shown that the bed expansion of the particles in the downcomer is directly affected by the superfcial liquid velocity in downcomer and solids circulation rate. The model also predicts the residence time of solid particles in the downcomer using a pulse technique. It is demonstrated that the increase in the superficial liquid velocity decreases the solids dispersion in the downcomer of the LSCFB,A comprehensive study on the hydrodynamics in the downcomer of a liquid-solid circulating fluidized bed （LSCFB） is crucial in the control and optimization of the extraction process using an ion exchange LSCFB. A computational fluid dynamics model is proposed in this study to simulate the counter-current two-phase flow in the downcomer of the LSCFB. The model is based on the Eulerian-Eulerian approach incorporating the kinetic theory of granular flow. The predicted results agree well with our earlier experimental data. Furthermore, it is shown that the bed expansion of the particles in the downcomer is directly affected by the superfcial liquid velocity in downcomer and solids circulation rate. The model also predicts the residence time of solid particles in the downcomer using a pulse technique. It is demonstrated that the increase in the superficial liquid velocity decreases the solids dispersion in the downcomer of the LSCFB,

关 键 词：Liquid-solid circulating fluidized bed Computational fluid dynamics DOWNCOMER Two-phase flow Ion-exchange system 

分 类 号：TQ051.13[化学工程] TQ027.34