粉体混合过程及搅拌功率的DEM数值模拟和实验

采用数值模拟与功率测试相结合的方法，研究直叶桨式粉体混合机搅拌过程及搅拌功率、扭矩的变化规律。对粉体混合机内球形颗粒的混合过程进行离散单元法DEM数值模拟，研究直叶桨式粉体混合机内搅拌转速、搅拌桨直径、桨叶数目等特性参数对粉体混合时搅拌功率和扭矩的影响，并拟合得到功率计算公式。搭建粉体搅拌试验台，测试粉体搅拌功率并与模拟结果比较。结果表明，直叶桨式粉体混合机内功率消耗与搅拌桨转速、搅拌桨直径、桨叶数目等特性参数有密切关系。同时，扭矩值和功率值与搅拌桨转速、搅拌桨直径和桨叶数目都呈正相关。实验得到了与模拟类似的扭矩-转速关系以及功率-转速关系，模拟值与测试值具有较好的吻合性，验证了所推导公式的准确性。

A discrete element method (DEM) simulation and experimental research on powder mixing process and stirring power

The mixing process, power and torque of straight blade impeller powder mixer were studied by combining numerical simulation with power test. The mixing process of spherical particles in the powder mixer was simulated by discrete element method (DEM). The effects of stirring speed, impeller diameter and blade number on the mixing power and torque were studied, and the power calculation formula was obtained by fitting. A powder mixing test-bed was built to test the power of powder mixing and compare with the simulation results. The results showed that the power consumption in the straight blade impeller powder mixer is closely related to the impeller speed, impeller diameter, blade number and other characteristic parameters. At the same time, torque value and power value were positively correlated with impeller speed, impeller diameter and blade number. The results showed that the torque speed relationship and power speed relationship were similar to the simulation, and the simulation values were in good agreement with the test ones, which verifies the accuracy of the derived formula.