DEM simulation of particle attrition in mechanofusion device

Abstract

Mechanofusion is a process used to enhance the mixing and coating of particulate materials by applying mechanical energy, by high shear and impact forces. Understanding stress distribution and attrition mechanisms is crucial for optimising this process. This study uses Discrete Element Method (DEM) simulations to investigate particle stress distribution and attrition during mechanofusion for particle shapes corresponding to α-lactose monohydrate and paracetamol crystals, and spheres. Three critical regions with high stresses are identified: at the 45° angle from the push arm, the scraper region, and the impact point after scraping. Particle shape significantly influences the stress magnitude, with tomahawk-shaped α-lactose monohydrate particles experiencing the highest stress. The Ghadiri and Zhang impact attrition model is implemented, showing that particle-wall attrition is the dominant breakage mode, while particle-particle collisions contribute minimally. The breakage rate of particles as a function of the drum rotational speed is also established.