Based on framework combined discrete element method and computational fluid dynamics

a gas-solid flow model in three-dimensional spouted bed was established and Fortran numerical simulation program was further developed. The mixing characteristics of two different diameter-sized wet or dry particles in three-dimensional spouted bed were simulated and the mixing mechanism of binary particles in the spouted bed was analyzed. Lacey mixing index was introduced to quantitatively analyze degree of mixing in whole bed and specific regions of the bed. The influences on mixing different sized particles were studied by volume of liquid bridge

ratio of particle densities and superficial gas velocity. The results show that both wet and dry particles flow similarly in single jet spouted bed without obvious agglomeration of wet particles. Liquid bridge had a greater influence on small particles than large ones

which reduced difference of velocity between wet particles with different diameters. Particle mixing in circular groove was critical to mixing across whole bed. Liquid bridge volume had a more significant influence on particle mixing

compared to ratio of particle densities and superficial gas velocity.