气流涡旋微粉机气固两相流场仿真分析

Simulation Analysis of Gas-Solid Two-phase Flow Field in Vortex Powder Mill

采用fluent欧拉多相流模型对气流涡旋微粉机腔室流场进行了数值模拟,并对模拟分析结果进行了实验验证。结果表明,在高速旋转锤头的作用下,腔室内部产生了较强的涡旋流场;锤头和齿圈之间的环形区域处颗粒速度梯度较大,石墨颗粒的球形化主要发生在该环形区域内;气流涡旋微粉机的锤头转速存在较优值,锤头转速过大或过小均会影响石墨颗粒的球形化效率。验证实验结果表明,锤头转速3600 r/min时,石墨颗粒受到的冲击较为合适,球形化效率较高。通过分析流场运动状态,可以更好地理解气流涡旋微粉机的球形化机理,为设备改进优化提供方向。

A eulerian multiphase model was adopted to simulate the internal flow field of vortex powder mill,and experiments were carried out to verify the simulation analysis results.According to the simulation,there are strong vortexes generated inside the chamber owing to the high-speed rotation of hammer.The spheroidization of graphite particles mainly occurs in an annular area between the hammer and the gear ring due to the large gradient of particle rotating velocity.There is an optimal speed for the hammer in the mill,as the spheroidization efficiency of graphite particles weakens at a higher or lower rotating speed.According to the experiment results,when the hammer rotates at a speed of 3600 r/min,the impact on graphite is rational,which benefits the spheroidization.Based on the analysis of the motion state of the flow field,the spheroidization mechanism of vortex powder mill can be better understood,which can provide notions for further optimization.