CFD modelling and simulation of hydrodynamics in liquid-solid circulating fluidized beds

Hydrodynamics in liquid-solid circulating fluidized beds (LSCFBs) are modelled and simulated by computational fluid dynamic (CFD) technique. Turbulence model and kinetic theory descriptions of granular flow are incorporated in the governing equations to model the high Reynolds number two-phase flows with strong particle-particle interactions in LSCFBs. Liquid-solid upflows under wide operating conditions, different particle properties and different bed dimensions are investigated by time-dependent simulations using commercial software, FLUENT 4.5.6. The model predictions show good agreements with the experimental data and reasonable trends when different fluids/solids and bed dimensions are applied. Stronger nonuniformities in flow structures are found in larger particle systems, with larger fluid/solids density ratios and/or larger diameter columns.