The influence of faceted particle shapes on material dynamics in screw conveying

Abstract

Screw conveyors are widely used in several industries to transport various granular materials needed to manufacture products or components in a product chain. Degradation of the material and variable packing in the screw pitches are some of the significant operational concerns. This paper explores the effect that particle shape has on the material’s behaviour in screw conveyors. Specifically, faceted polyhedral particles are considered and computed on GPUs using the DEM code, Blaze-DEM. Particle shape significantly influences bulk discharge characteristics, in particular, for higher rotation speeds of the screw. Although spheres yield similar bulk discharge rates to symmetric and equiaxed polyhedra at lower rotational speeds, the packing structure and collision dynamics within the screw are shown to be significantly different between the particle shapes. In general polyhedra have a larger fraction of normal impacts between particles and increased abrasion with the screw and enclosing case. On the other hand, spheres have the highest fraction of energy dissipated as shear between particles.