A new model of gas solid flow pattern for fast fluidization has been developed based on laboratory investigation and related literature. With regard to the axial and radial distributions of solid density and the internal particle circulation

this new mathematical model for fast fluidization is superior in clear physical concept and fewer parameters. All the model parameters are correlated by using experimental results from different investigators. These empirical correlations may be used in predicting the voidage distribution for fast fluidization as well as in interpreting the dynamics of the solid particles.