Scaling up studies for mixing of granular materials in rotating drums

This study investigates the mixing of granular materials for rotating drums of different volumes which vary from 6.28 L to 402.12 L. Two groups of case studies are considered: Group I (constant particle diameter, d) and Group II (constant ratio of drum diameter to particle diameter, D/d). The results show that for Group I, the mixing performance deteriorates with drum size increasing. A correlation as a function of scale-up ratio and Froude number is proposed for mixing rate prediction. For Group II, at a constant Froude number, particle flow patterns and mixing performance are similar. The results also demonstrate that the scaled particle travel distances and displacements are affected by the ratio of D/d. For Group I, the scaled particle travel distances and displacements become more restricted as drums become larger, causing a delay in mixing. For Group II, similar particle travel distances and displacements are observed, hence the similar mixing performance.(c) 2022 Published by Elsevier B.V.

Automated summary

This study investigates the mixing of granular materials in rotating drums with different volumes. The results show that mixing performance is affected by drum size and particle diameter. A correlation equation is proposed for predicting mixing rate, and the ratio of drum diameter to particle diameter influences particle travel distances and displacements. The findings are significant for understanding the mixing mechanism of granular materials.