Segregation dynamics of the binary-size granular system in a split rotary drum

Abstract

Driving and controlling the segregation of particles with different properties in a rotary drum is theoretical and challenging work in powder technology. In this work, a novel split drum composed of two counter-rotating sub-drums was explored to drive the size-induced axial segregation of particles. DEM (Discrete Element Method) simulations were performed to study the particle dynamic and segregation performance in the split drum. Then, the influence of drum speed and the speed ratio between two sub-drums was analyzed. The analysis of the segregation process shows that binary-size particles in the split drum have a faster and better axial segregation than that in the conventional drum, small particles tend to concentrate near the split of the drum. The region-averaged velocity of large particles near the split is smaller than that at both ends of the axial segregation region. The results obtained indicate the width of the axial segregation region increases with the increase of drum speed. When two sub-drums rotate at different speeds, the band of small particles moves toward the low-speed sub-drum, small particles tend to be concentrated in the low-speed sub-drum, and large particles tend to accumulate in the high-speed sub-drum.