基于离散单元法的立磨机介质球运动规律研究

Study on movement laws of media in vertical stirring mill based on DEM

为查明立磨机磨矿介质球的运动规律,采用离散单元法进行了立磨机数值模拟,研究分析了介质球的受力、运动学参数、能量分布以及介质球之间的碰撞行为。研究结果表明,磨矿介质球的速度、动能在搅拌器螺旋叶片边缘达到最大值;其碰撞力、自转角速度、转动动能、碰撞能在搅拌器外缘达到最大值;环形区内介质球的碰撞力和速度梯度均较大,是重要的磨矿区域。通过分析碰撞力、碰撞能分布曲线,可以从微观角度剖析立磨机的磨矿行为,为强化立磨机的精确化磨矿和选择性磨矿提供了具体方向。

In order to ascertain the movement laws of the grinding ball in the vertical stirring mill, the paper applied discrete element method（DEM） to conduct numerical simulation of the vertical stirring mill, and studied the grinding ball about its force state, kinematic parameters, energy distribution and interaction collision. The study results showed： the velocity and the kinetic energy of the grinding ball reached the maximum at the edge of the spiral blade of the agitator; the collision force, the rotational angular velocity, the rotational kinetic energy and the collision energy of the grinding ball reached the maximum at the outer edge of the agitator; the collision force and the velocity gradient of the grinding ball in annular zone were considerable large, so the annular zone was the important grinding zone. Through analyzing the variation curve of the collision force and the distribution curve of the collision energy, the grinding behavior of the vertical stirring mill was researched from microscopic point of view. The results offered specific direction for the identification of accurate grinding and selective grinding of the vertical stirring mill.