Flow Behavior of Geldart A and Geldart C Particles in a Co-current Downflow Circulating Fluidized Bed Reactor

The purpose of this research is to study the effect of Geldart A and C particles on the hydrodynamics behavior in a 9.3 m height, 0.1 m diameter co-current downflow circulating fluidized bed (downer reactor) using CFD simulation. Two-fluid model with kinetic theory of granular flow was adopted to predict flow behavior in the system. The simulation results show that hydrodynamics behavior in the downer strongly depends on the type of the particle. Geldart C particle exhibits a more uniform distribution along the lateral direction as compared with Geldart A particle. In addition, the effects of operating conditions were also studied. The uniformity of lateral direction of solids fraction increases with decreasing of solids circulation rate (Gs) or increasing of inlet superficial gas velocity (Ug). However, the radial distributions of gas and solids velocity are more uniform when Ug decreases especially for Geldart C particle. (C) 2014 INT TRANS J ENG MANAG SCI TECH.