CFD-DEM investigation of particle breakage in spout-fluidized beds

Abstract

In a fluidized bed, particles undergo mechanical stress resulting from collisions with other particles, the bed walls, or internal equipment. Particle breakage exerts a significant impact on the hydrodynamics and overall performance of the fluidized bed by modifying the particle size distribution. This study explores this phenomenon through the application of an enhanced computational fluid dynamics-discrete element method (CFD-DEM) coupled with a particle breakage model in three distinct flow regimes: spouted bed, jet-in-fluidized bed, and spouting-with-aeration bed. The simulations revealed various aspects related to particle breakage, encompassing the spatial and temporal distribution of particle sizes, the location of breakages, breakage rates, solid particle fraction, and the height of the bed. The findings establish a pronounced correlation between the breakage rate and the velocity of the jet, with the spouting-with-aeration bed displaying the highest level of particle breakage. Furthermore, it is noteworthy that nearly 98% of the breakages occur within the distributor zone.