新型钾盐结晶器内部流场模拟及性能预测

由于钾盐结晶器内部流动的复杂性及流域的多态性，通过实验测量很难得到其流场形态。应用计算流体力学仿真技术，对某新型钾盐结晶器在连续结晶过程中形成的流场进行数值模拟，模拟连续结晶过程的晶体悬浮及固液相混合流动状态，得到了结晶器在不同搅拌速度下的内部流场速度分布、流线图、压力分布及固相悬浮状态分布等信息。模拟结果表明，搅拌速度对结晶器内部的流场分布具有明显的影响，通过比较流场特征确定能够使此新型结晶器运行经济合理的搅拌速度为40～45 r/min，与厂家的测试结果相吻合。本文研究结果可为确定结晶器合适的电机功率奠定基础，为结晶器在不同搅拌速度下的性能预测提供参考依据。

Simulation of the flow field and performance prediction for a new crystallizer

It is very difficult to obtain the flow field form through experimental measurements due to the complexity of the flow in a mechanical mold and the polymorphism of the drainage basin.The flow field formed by the crystallization of a potassium salt was simulated using computational fluid dynamics for a new type of crystallizer with various stirring speeds.The continuous crystallization process is simplified as a simulation of single crystal suspension and solid-liquid flow state.Information about the velocity field and streamlines of the solid and fluid,the static pressure field,and the distribution of the crystals volume fraction were obtained.The simulation results indicated that the rotational speed has a significant impact on the distribution of the flow field and the crystal volume fraction.The most economic and reasonable stirring speed in the crystallizer,in accordance with the test results of the manufacturer,was found to be 40-45 r/min.The results lay the foundation for determining the appropriate moter power,and also provide a reference for predicting the performance of the crystallizer at different speeds.