滚筒内二组元颗粒混合与分离的数值模拟

Mixing and Segregation of Binary Particles in Rotating Drum:a Numerical Study

滚筒是工业过程中处理固体颗粒的一种常用设备,本文采用离散元(Discrete Element Method,DEM)方法软球模型对滚筒内两种粒径颗粒运动进行模拟。针对不同转速下颗粒分布,提出了表观混合指数和动态混合指数来衡量两种颗粒的混合程度。利用混合指数,对于颗粒混合随时间的变化进行了研究。结果显示了不同转速下迥异的分布特性。同时,对于不同转速下二元颗粒的混合与分离,分析探究了其内部机理。最后,从能量角度探究了不同转速下滚筒内颗粒运动。

Rotating drum is widely used in industry process for particle treatment. In this study, discrete element method coupled with soft sphere method are applied to investigate the solid motion of binary mixture in rotating drum. For the various particle distribution under different angular speed, two mixing index are introduced to determine the mixing degree of particles mixtures. Mixing indices are measured to show how mixing and segregation change in time of solid under different rotational speed. The mixing mechanism of solid motion is also discussed in aspect of energy. Results reveals distinct patterns solid mixtures is analyzed. The