CFD Simulation of Bubbling Gas- Solid Fluidized Bed

In this research, unsteady state behavior of gas-solid fluidized beds has been investigated using CFD simulation methods. For this reason, a two dimensional system of jet gas flow in a fluidized bed with axial symmetry has been studied. In order to model this system Eulerian-Eulerian approach has been applied for both gas and solid phases. The model includes continuity equations as well as momentum equations for both phases and the equations for granular temperature of solid particles. MFIX software that applies finite volume method has been employed to solve the model equations. The effects of jet velocity on the bed hydrodynamic as well as the influence of particle density and size, jet velocity, and initial bed height on the bed pressure drop were investigated. The results revealed that, compared with jet velocity and particle size, initial bed height and particle density have more impact on pressure drop. A comparison of predicted bubble size with the corresponding data in the literature indicates a good agreement between them. Also gas flow inside the bubble compared with Davidson model and result of this simulation shows good agreements with this model.