Computational Fluid Dynamics-Discrete Element Method Studies on Dynamics and Segregation in Spouted Bed with Polydispersed Particles

The computational fluid dynamics-discrete element method (CFD-DEM) technique has been used to investigate the translational and rotational dynamics of poly-dispersed particles in a pseudo-two-dimensional spouted bed. Minimum spouting velocity is predicted numerically and compared with the experimental measurements. The mean particle-phase translational and angular velocities have been computed and compared for finer and coarser particles. The dynamics of the polydispersed particles have been compared with monosize particles having an equivalent Sauter mean diameter. In the polydispersed bed, particles with lower diameters spread up to the wall of the spout setup, leading to a reduction in a particle-free zone away from the core. Segregation of the finer and the coarser particles has been assessed for different superficial gas velocities. The bigger particles are concentrated in the central part of the bed, and their concentration decreases laterally from the spout to the annulus region. An increased concentration of finer particles is observed near the wall. The extent of near-wall segregation decreases with an increase in gas velocity.