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.

Discrete particle simulation of dispersed gas-solid flows was made laking into account of particle-to-particle collision. DSMC (Direct Simulation Monte Carlo) method which has been developed in the field of molecular gas dynamics is applied to consider the effects of collision. Chaotic motion in the gas-solid flows can be obtained by using simple models of collision and particle-to-gas interaction.