中文摘要：

为深入了解结晶器内复杂的流动情况及其对混合的影响,采用CFD（Computational Fluid Dynamics）软件模拟DTB结晶器内稳态单相流动过程和不同混合方式的多相流动过程。对不同搅拌桨在结晶器内单相流动作用时采用湍流模型中的标准k-ε双方程模型、MRF;在此基础上模拟4种不同混合方式对颗粒性质的影响时引入欧拉多相流模型,并分析其不同混合方式产生的不同剪切作用对颗粒粒度的影响,并分析产生影响的微观作用机理。结果表明,考虑颗粒在结晶器内所受剪切力的状况和悬浮状况有利于制备理想性质的颗粒。

英文摘要：

In this work,a CFD（Computational Fluid Dynamics） software was used to understand how the complicated flow affect the mixing process and crystallization in a DTB（Draft Tube Baffled） crystallizer agitated by a pitched blade impeller.A single phase flow simulation was initially carried out to demonstrate the original flow pattern without feeding by solving the governing equations and standard two equation k-ε turbulence model in MRF（moving reference frame）.According to the flow field obtained,four mixing types which vary in feeding position and impeller pumping direction were designed and the liquid-solid flow of different mixing type was simulated by using Eulerian multiphase equation along with the governing equation and standard two equation k-ε turbulence model.Visualization of the particle distributions of different mixing type and the shear rate distribution of the plane across the impeller help to assess the particle dispersion and movement during crystallization to gain better understanding of the mechanism.It showed that the particle having expected property can be made if optimization operation was found and carried out.