Influence of cycle time distribution on coating uniformity of particles in a spray fluidized bed by using CFD-DEM simulations  

作　　者：Heng Li Daoyin Liu Jiliang Ma Xiaoping Chen 

机构地区：[1]Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,School of Energy&Environment,Southeast University,Nanjing,210096,China

出　　处：《Particuology》2023年第5期151-164,共14页颗粒学报（英文版）

基　　金：supports by National Nature Science Foundation of China(grant No.51976037).

摘　　要：Cycle Time Distribution(CTD)plays a critical role for determining uniformity of particle coating in spray fluidized beds.However,the CTD is influenced by both geometrical structure and operating conditions of fluidized bed.In this study,a spray fluidized bed of coating process is simulated by a comprehensive Computational Fluid Dynamics-Discrete Element Model(CFD-DEM).To achieve different behaviors of CTD,some modifications are designed on a pseudo-2D internally circulating fluidized bed,which traditionally composes of a high-velocity upward bed and low-velocity downward bed.These modifi-cations include making the air distributor slope and/or laying a baffle in the downward bed.First,the CTD and evolution of particle size distribution under different bed structures are compared.The CTD directly influences the coating uniformity.By making the particles flowing along a parallel direction in the downward bed through the geometrical modifications,the CTD becomes narrower and the coating uniformity is significantly improved.Second,under the optimized bed structure,the influence of oper-ating conditions on the coating uniformity is studied.Properly increasing the fluidization gas velocity and the fluidization gas temperature and reducing the liquid spray rate can improve the coating uniformity.

关 键 词：Spray fluidized bed Particle coating Cycle time distribution CFD-DEM 

分 类 号：TB3[一般工业技术—材料科学与工程]