导向管喷动流化床内宽筛分硅颗粒流化特性的实验及模拟  

Experiment and simulation on the flow characteristics of silicon particles with a wide size distribution in draft tube spout-fluid bed

作　　者：张月梅[1] 黄国强[1] 苏国良[1] ZHANG Yuemei;HUANG Guoqiang;SU Guoliang(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学化工学院,天津300072

出　　处：《化工进展》2017年第7期2381-2392,共12页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金项目(21676197)

摘　　要：在内径为182mm的导向管喷动流化床中,以亚毫米级的宽筛分硅颗粒为物料,对喷动气旁路特性进行了实验研究,分别考察了静止床层高度、夹带区高度、导向管内径、喷动气速和流化气速对喷动气旁路分率的影响。结果表明喷动气的旁路分率随喷动气速的增加首先保持平稳,随后降低直至保持稳定值;当喷动气速较小时,旁路分率随静止床层高度的增加而增加,当喷动气速足够大时,静止床高的变化对旁路分率影响不大;此外,喷动气旁路分率随流化气速、导向管内径的增加而增大,但随着导向管安装高度的增加而减小。同时,采用基于颗粒动力学理论的双欧拉模型,通过Fluent建立了与冷态实验条件一致的导向管喷动流化床气固两相流的数理模型,经计算流体力学模拟考察了相关参数对模拟结果的影响。结果表明压降与实验值吻合,流态化外观也与实验结果一致。所建立的模型具有一定的准确性和可靠性,可以成为预测实验结果的有效途径。A cylindrical spout-fluid bed(182mm in inner diameter)equipped with a draft tube andloaded with sub-millimeter grade silicon particles of wide size distribution was used to study the gasbypassing fraction of spouting gas.Effects of static bed height,entrainment zone height,draft tubediameter,and the spouting and fluidizing gas velocity on the gas bypassing fraction of spouting gaswere investigated.The results show that the gas bypassing fraction of spouting gas remains stable atlow spouting gas velocities and decreases thereafter.At high spouting gas velocities,it reaches a stablevalue.At low spouting gas velocities,the gas fraction increases with the static bed height.When thespouting gas velocity is sufficiently high,the static bed height has little effect on the gas bypassing.Inaddition,the gas fraction increases with the fluidizing gas velocity and the draft tube diameter,butdecreases with the entrainment zone height.Furthermore,a mathematical model for gas-particletwo-phase flow in draft tube spout-fluid bed was established based on the Eulerian-Eulerian modelaccording to the kinetic theory of granular flow.Effects of related parameters on simulation resultswere investigated by CFD simulation.The numerical simulation shows that both the calculated bedpressure drop and fluidization appearance show good agreement with the experimental results.Regarding applicability and reliability of the proposed model,it could be an effective tool to predict the experimental results.

关 键 词：导向管喷动流化床 宽粒度分布 气体旁路 两相流 计算流体力学 数值模拟 实验验证 

分 类 号：TQ127.2[化学工程—无机化工]