Modeling the axial hydrodynamics of gas-solid counter-current downers  

作　　者：Juanbo Liu Xinhua Liu Zhixin Zhang Hui Zhao Wei Ge 

机构地区：[1]State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China [2]School of Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100490,China [3]State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Qingdao 266555,China

出　　处：《Particuology》2020年第3期135-143,共9页颗粒学报（英文版）

基　　金：the Strategic Priority Research Pro-gram of the Chinese Academy of Sciences(No.XDA07080400);the Informationization Program of the Chinese Academy ofSciences(No.XXH13506-301)。

摘　　要：Gas-solid counter-current downer reactors,in which particles move downward in an upward gas flow,can achieve high solid concentration for high heat and/or mass transfer rates.However,the particles may reverse their direction or even be carried out of the reactor as the gas flow rate increases.This is closely related to "flooding" in counter-current flows.The energy minimization multiscale (EMMS) model well describes multiscale heterogeneity in gas-solid cocurrent upward flows.It is further developed to simulate gas-solid counter-current downward flows because similar heterogeneity can also be found in downers.The model characterizes well the axial hydrodynamics and predicts an inflexional voidage variation with superficial gas velocity in the fully developed region.This is supported by a simulation based on computational fluid dynamics and the discrete element method.The flooding predicted by the model agrees better with experiment than previous models.

关 键 词：Mathematical modeling Counter-current downer FLOODING EMMS MESOSCALE 

分 类 号：O35[理学—流体力学]