CFD-DEM investigation of fluidization of the non-monodisperse particle system in a spouted bed

Abstract

Spouted bed is a type of fluidized bed that has been widely used in various industrial processes because of its excellent mass and heat transfer efficiency. In practical applications, the fluidization of the multicomponent particle system containing non-spherical particles is frequently encountered in spouted beds. To better understand the spouting behaviors of the multicomponent particle system, therefore, this study employs a CFD-DEM (Computational Fluid Dynamics-Discrete Element Method) coupling approach to investigate the spouting behaviors. Spherical particles along with two types of ellipsoidal particles (i.e., oblate ellipsoid, and prolate ellipsoid) are included in this paper. Through the combination of these three particle types, seven distinct systems (three monodisperse systems, three binary mixtures, and one ternary mixture) are simulated to analyze the effects of particle shape and composition of particle systems on spouting behaviors. The simulation results reveal that introducing non-spherical particles into systems containing either spherical or oblate ellipsoidal particles tends to enhance spouting behaviors, whereas adding spherical particles to prolate ellipsoidal particle systems inclines to suppress it. The addition of non-spherical particles into the spherical particle system can enhance the particle interlocks, and using the oblate particles should have more important influence than prolate particles. Moreover, the influence of particle shape on the spout deflection behaviors is quite complicated, and the use of prolate ellipsoidal particles versus oblate ellipsoidal particles may produce opposite effects. These findings should provide valuable insights for optimizing spouted bed operations involving complex particle mixtures.