Analysis of powder behaviour in bin blending processes at different scales using DEM

Obtaining a desired content uniformity with satisfactory flowability is one of the main challenges during blending process of the pre-mixture with lubricants. In this study, Discrete Element Method (DEM) simulations were implemented to examine blending time and mixing behaviour during the blending process on the lab and industrial scales. The main goal was to investigate the possible influence of operational conditions on the blending behaviour and the change in powder cohesivity during the scale-up process. The effects of rotational speed and filling mass on the particles' travelled distance, velocity, shear stress and blending time were studied in the simulations. Based on the simulations, blending time and particle exposure to shear during the blending process were calculated for different scales. It was observed that the system's mass significantly influences them, and the effect of rotational speed could be neglected. The novelty of this paper is connecting particle exposure to shear from DEM to the flow function coefficient (ffc) of powder from experiments. It was done to define a critical range of exposure to shear that changes the powder flowability in different scales.