ANALYSIS OF FLOW AND MIXING CHARACTERISTICS OF NON-SPHERICAL PARTICLE MIXTURES IN A ROTATING DRUM

Abstract

This study investigates the flow and mixing characteristics of powder mixtures that incorporate non-spherical particles using both experimental and DEM simulation methods. Investigated particulate materials include Aluminum Oxide (Al2O3), Aluminum-Alloy (AlSi10Mg), and two composite materials: one composed of 90% AlSi10Mg and 10% Al2O3, and the other composed of 95% AlSi10Mg and 5% Al2O3. A rotary drum apparatus is used experimentally with different rotational speeds (5, 10, 15, 20, and 30 rpm) to study powder behavior. High-speed videography records the dynamic angle of repose and flow patterns. The results demonstrate a clear correlation between rotation speed and dynamic angle of repose, suggesting that disturbance of the particles increases with higher speeds. Our findings reveal that optimal rotation speeds significantly enhance mixing performance along with best optimized values for achieving a DAOR and promoting mixing efficiency. Three flow regimes, rolling, cascading, and cataracting, are distinguished in the drum due to the effects of rotation speed and particle interactions. Analysis of the segregation index suggests increased rotation speeds enhance mixing efficiency, leading to less particle segregation in composite mixtures. The mixture's composition significantly impacts mixing behavior, as a higher ceramic concentration enhances mixing efficiency. It is critical to regulate rotation speed and particle composition in mixing processes to ensure uniform mixes. This study provides valuable insights into the behavior of powder and the effectiveness of mixing in rotary drums. The work improves comprehension of the parameters affecting powder flow by combining experimental data with DEM models.