Prog. Chem.

Choking is a typical critical phenomenon in gas-solid fluidization featuring abrupt structural changes. The energy minimization multi-scale (EMMS) model is capable of analyzing the mechanism of this phenomenon. In this paper, two criteria for choking previously proposed on the basis of the EMMS model are discussed with the emphasis on the difference and consistency between them. Simulation result shows that the saturation carrying capacities calculated with the two criteria are approximately equivalent at given gas velocities. It is demonstrated further that the mechanism reflected by these two criteria is consistent. Both criteria have defined the critical condition for the regime transition between fast fluidization and dilute transport