Numerical simulation on expansion characters of solid phase in two phases fluidized bed

CFD(Computational Fluid Dynamics) numerical simulation method was adopted to study on the solid expansion character in flow process of two phases fluidized bed including liquid and solid phases and testify the reliability. Commercial CFD software-Fluent was used in the study under some proper boundary conditions, such as velocity inlet, pressure outlet, symmetry condition for free liquid surface, standard k-ϵ model for turbulence and Gidapow model for inter-phase drag forces. Beside these, time dependent method was used in numerical simulation. Results of simulation were verified with calculation results of Richardson-Zaki experiential relations which were approved widely and they agreed well. The results of simulation could predict bed height and volume fraction of solids for expanded fluidized bed accurately; dynamical simulation could illustrate the start-up process of fluidized bed visually; numerical simulation in CFD could give some theoretical instructions for scale-up design of fluidized bed.