The behaviors of particle-wall collision for non-spherical particles: Experimental investigation

Abstract

The particle-wall collision behavior for non-spherical particles has significant effects on gas-solid separation, which is important in mechanical, energy and other industries. Particle-wall collision experiments of spherical and non-spherical glass particles with polished and rough walls were conducted. The collision velocities were measured by high-speed photography, and the effects of particle sphericity and wall roughness were analyzed. The results show for large impact angles α1, the restitution coefficient e is independent of α1 and increases with increasing particle diameter. For the non-spherical particles or the rough wall, e increases when α1 is small and the friction coefficient f increases with decreasing α1. The non-spherical particles have smaller e, and larger f for small α1. The rough wall has smaller e for large α1 but greater dependence of e on α1, resulting in larger e instead for α1 → 20°. Under sliding condition, f increases with increasing wall roughness or decreasing particle diameter.