Flow behavior inside a novel rotating fluidized bed for solar gasification of biomass

Abstract

The present paper reports a numerical investigation of the iso-thermal flow field and particle deposition onto the reactor window of a novel concept of Rotating Fluidized Bed Solar Reactor (RFBSR) and their sensitivity to reactor inner diameter. The RFBSR differs from conventional fluidized bed solar reactors in that it relies on the centrifugal force generated through rotation to counteract the drag force produced by the fluidizing gas on the particles. A three dimensional Computational Fluid Dynamics (CFD) model of the RFBSR was developed and combined with a Lagrangian particle tracking model to investigate the flow velocity components at various locations and particle concentration onto the window surface. The CFD model was partially verified by comparing its predictions with the published experimental measurements in a rotating porous cylindrical vessel with a radially injected flow. It was found that the Baseline Reynold Stress Model (RSM BSL) produces more agreeable predictions with the experimental measurements than Re-Normalization Group (RNG) k-ε and k-ω Shear Stress Transport (SST) models. Also, it was found that for the reactor configurations investigated here, reducing the reactor diameter has the effects of increasing the core axial flow velocity and particle deposition onto the window. The results presented assist in developing an understanding of the operation of the RFBSR.