Dynamic analysis of blockage behavior of fine particles in a packed bed by discrete element method

Abstract

The dynamic blockage behaviour of fine particles in a packed bed was simulated using the discrete element method (DEM). The influence of key variables are examined. The calculation results showed that fine particles blockage in packed bed are easy to occur in the area where fine particles just enter the bed. The mechanism of blockage formation is mainly due to mechanical interactions between fine particles, which can create arches on packed bed and stop the flow. When the fine particles form a bridge across the pore throat of the orifice, the bottleneck of void space becomes the starting point for blockage formation. The fine particles with a larger rolling friction coefficient have a higher clogging ratio. With the increase in charging fine particles, the fine particles experience more collisions with each other, and the clogging ratio increases. The initial velocity of fine particles also has an impact on the blockage behaviour.

An unresolved CFD-DEM method for studying migration and clogging of fine particles through a packed bed

“…In a simplified stacking structure, Luo et al studied the clogging tendency of viscous fines by the DEM model and described how adhesion affected drop velocity and clogging frequency [21]. She et al simulated the dynamic clogging behaviour utilizing a DEM model and examined the effects of important factors, as well as proposed a mechanism for clog formation [22]. These methods are limited only to the acquisition of detailed perimetric kinetic information of individual particles, and they are not well able to achieve a good coupling between the liquid part and the particles.…”