Computer simulation of bubbles in large-particle fluidized beds

A distinct element model is used to study the hydrodynamics of large-particle fluidized beds. The computed bubble rise velocity, voidage variations, averaged particle/particulate and fluid velocities are compared with the other continuum theory based on two fluid model. Based on the averaged particle/particulate velocities in a grid cell, deformation of the particle layers predicted by the two fluid model and the distinct element method are also compared. The predicted characteristics of bubble formation, motion, and eruption at the bed surface are in good qualitative agreement with the experimental observations. The quantitative differences in predicting the above parameters along with the advantages and limitations of two approaches for the case of a single isolated bubble rising in a two-dimensional fluidized bed are discussed. (C) 1998 Elsevier Science S.A, All rights reserved.