Simulation of gas/solid flow behaviors and choking for a CFB riser: The EMMS/CFD approach

This paper presents a drag model based on the Energy-Minimization Multi-Scale (EMMS) approach. Compared to the empirical drag correlations, the incorporation of this EMMS-based drag model with the two-fluid model can well capture the meso-scale heterogeneous structure and improve the simulation results of the gas/solid flow behaviors for a CFB riser with Geldart-A particles. The EMMS model itself is also adapted to predict the choking phenomena for a CFB riser, and the comparisons are carried out among this calculation, the experimental measurements, the empirical correlation presented by Xu et al.(1) and the simulation results from the combination of the EMMS and CFD approaches.