Omidbakhsh - Chemical Engineering Group, Semnan University, Semnan, Iran.
Hormozi - Chemical Engineering Group, Semnan University, Semnan, Iran.
Haghighi Asl - Chemical Engineering Group, Semnan University, Semnan, Iran.

This paper presents a computational study of the flow behavior in a cold-flow scale circulating fluidized bed. A multi-fluid Computational Fluid Dynamics (CFD) model has been developed and verified against experimental data reported in the literature. The flow model is based on an Eulerian description of the phase where the kinetic theory of granular flow forms the basis for the turbulence modeling in the solid phase. The model is generalized for one gas phase and mean particle size of solids phase to enable a realistic description of the particle size distribution in gas - solids flow systems. Solid phase is characterized by a mean diameter, density and restitution coefficient. Most emphasis is given to study the effects of mean particle size distributions to study the fluctuating behavior of the dilute gas-solids flow system. Altogether, the simulation results are in good agreement with experimental data. Both mean diameters, axial and radial mean and turbulent velocities are calculated successfully.

Eulerian CFD model; Gas–particle flow; Circulating fluidized bed