THE SEGREGATION AND MIXING OF BINARY GRANULAR SYSTEMS IN ROTATING MIXER WITH DIFFERENT CROSS-SECTIONS

The effects of filling conditions and angular speeds of circle, ellipse and square mixers on segregation and mixing are studied adopting theoretical, experimental and simulation approaches. Different segregation and mixing patterns of granular material can be obtained by changing the angular speed or filling conditions in experiments. From the analysis of trajectory of tracer particles, we find that particles' motion randomness in radial direction decreases with the angular speeds augment, and contrast results occur in rectangular mixer. The simulation results show that the flow consists of two distinct regions: a flowing layer with nearly unidirectional flow and a bed below it undergoing solidbody rotation. Through theoretical analysis, we find the segregation phenomenon is most apparent in circle mixer, then in the ellipse mixer, and the weakest is in rectangular mixer.