(741d) Hopper Discharge of Wet and Dry Non-Spherical Particles

Steady flow of particulate or granular materials and bulk solids through a hopper plays a critical role in many industrial and process engineering applications.  The present work investigates hopper discharge of non-spherical particles, specifically cylindrical and flake-like particles, from a rectangular hopper. The behavior of steel and plastic non-spherical particles with varying aspect ratio (both varying diameter with constant length and varying length with constant diameter) were explored experimentally and via DEM simulations.  In addition, the effect of fill height and hopper angle on hopper discharge rate of these non-spherical particles was determined. Results with particles of high aspect ratio indicate a different trend than that previously observed with rounded particles.  As the fill height increases, the mass discharge rate increases and then asymptotes; further increases in fill height cause a decrease in the mass discharge rate. In addition, a decrease in the hopper angle decreases the mass discharge rate flow. For wet (cohesive), non-spherical particles, a drop in mass discharge rate, compared to cohesionless particles, was observed. Furthermore, it was found that increasing liquid contact decreases the mass discharge rate but this effect becom4e small at higher liquid contents greater than 8%. Finally, experimental results are directly compared to predictions from DEM simulations probing (also) the effect of particle aspect ratio and hopper geometry (fill height, hopper cone angle).