旋转填充床中微观混合模型与实验验证

Modelling and experimental validation of micromixing in rotating packed bed

根据旋转填充床中液体流动和混合特征,建立了一个新的复合式微观混合模型,并对串联竞争反应的标准体系进行了模拟和实验验证。结果表明,在旋转填充床内,当体积比α较小时(如α=2),微观混合影响很小,过程处于化学反应控制区;当α较大时(如α=20),过程处于微观混合作用区,提高转速使离集指数降低,流量增加对离集指数影响很小;考虑液体初始宏观分布不均匀对混合的影响,模型计算结果与实验结果吻合良好。

Coupled with coalescence-redispersion model and lamella model,a new model was presented to describe the flow,mixing and reaction process in rotating packed bed（RPB）and calculate the mixing-dependent product selectivity.The model was solved numerically with boundary conditions of RPB characteristics.As operational variables were changed,the model predicted well the effect of variables on the product selectivity while considering macro-distribution non-uniformity of inlet liquid.The influence of volumetric ratio,rotating speed and flow rate on segregation index was investigated.The results showed that the process was controlled by reaction kinetics while operating at a small volumetric ratio,but the micromixing rate had remarkable effect on the reaction process at a high volumetric ratio.In the micromixing-controlled region,segregation index decreased with increasing rotating speed but the increase of flow rate had little effect on segregation index.