摘要
旋转填料床又称超重机,通过旋转产生的离心力来实现超重力环境,能有效地强化微混合及传质过程,在快速化学反应过程上有广泛的应用,如制备纳米粉体材料等。旋转填料床内的湍流反应涉及在填料中流体流动与混合反应过程,针对2股无预混反应物料的湍流混合及反应,通过商用软件Fluent的计算平台,采用涡耗散模型(eddy-dissipation)模拟碘酸盐-碘化物体系的平行竞争反应。涡耗散模型认为反应速率由湍流控制,避开了代价高昂的Arrhenius化学动力学计算。计算过程收敛良好,流场与各组分浓度分布合理。考察了转速及初始浓度对离集因子的影响,模拟结果与相关文献的实验数据吻合良好。
Rotating packed bed （RPB）,known as HIGEE,an acronym for high gravity has been widely used in absorption,desorption,distillation,oxidation,crystallization,precipitation,polymerization,production of nanoparticles.RPB utilizes centrifugal acceleration to intensify the mixing and mass-transfer processes.The turbulence reactions in RPB include flows in the packings,mixing and reactions.Based on computational platform,Fluent software,the turbulence reactions with two non-premixed solutions are simulated.The eddy-dissipation model is used to calculate the parallel competing reaction system,iodide-iodate system.In the eddy-dissipation model the overall rate of reaction is controlled by turbulent mixing,then the complex chemical kinetic rates can be safely neglected.The distributions of flow and species concentration are reasonable.The influences of initial reactant concentration and rotating speed on the segregation index were investigated.The segregation index seems to be sensitive to the reactant concentration.Higher rotating speed leads to lower segregation index,which is validated by others researches.
基金
国家863计划(2006AA030202
2006AA05Z316)
高等学校博士学科点专项科研基金(20070003154)
关键词
微混合
CFD模拟
旋转填料床
涡耗散模型
micromixing
CFD simulation
rotating packed bed
eddy-dissipation model
