Magnetic reduction of gas back-mixing in bubbling fluidized beds with Geldart-B magnetizable particles  

作　　者：Qiang Zhang Yalong Cao Wankun Liu Hao Guan Donghui Liu Quanhong Zhu 

机构地区：[1]College of Chemical Engineering,Qingdao University of Science and Technology,Qingdao,266042,China

出　　处：《Particuology》2024年第12期92-102,共11页颗粒学报（英文版）

基　　金：supported by Shandong Provincial Natural Science Foundation (grant No.ZR2023MB038);Youth Innovation Team Program of Shandong Higher Education Institution (grant No.2022KJ156).

摘　　要：This study investigated the performance of magnetic fields in reducing gas back-mixing in bubbling fluidized beds with Geldart-B magnetizable particles.The Peclet number(Pe)and axial dispersion coefficient(Da,g)were determined using the one-dimensional dispersion model.A weak magnetic field reduced gas back-mixing to a certain extent,while a moderate field resulted in minimal decrease.The performance of a strong magnetic field varied significantly depending on the operation mode.Under the magnetization-FIRST operation mode,gas back-mixing was significantly reduced.The corresponding Pe and Da,g were calculated as∼76 and∼3.6×10^(−4) m^(2)/s,indicating that the gas flow approached the ideal plug-flow manner.However,when the magnetization-LAST operation mode was used,the strong magnetic field failed to mitigate gas back-mixing.Therefore,the performance of magnetic fields in reducing gas back-mixing depended not only on their intensity but also on their application sequence to the gas flow field.

关 键 词：Magnetized fluidized bed Gas back-mixing Gas residence time distribution Operation mode Axial dispersion coefficient Steady-state tracing method 

分 类 号：TQ021.1[化学工程]