The behavior of particle flow in a new type of gas-solid air loop reactor (GSALR)

which acted as a particle mixer

was numerically simulated by multi-scale computational fluid dynamics (CFD) with the structure-dependent EMMS drag model. The suitability of the drag model was verified by agreement of the simulated results and the experimental data in time averages of solid holdup and particle velocity. The particle upward velocity increased but the mean solid holdup on beds decreased when the superficial gas velocity increased in the draft tube. Several mixing regions of particle crossflow and mixed flow in GSALR improved the efficiency of radial particle mixing. In the groove region

the distributions of solid holdup and particle velocity were more uniform

while a particle concentrating area was formed at circular overlap due to particle flow from the groove. In the region of 0≤L≤0.058 m and 0< r/R< 0.3

the solid holdup was increased and particle flow was evidently enhanced along the radial direction.