Hydrodynamic Studies of Three-Phase Fluidized Bed by Experiment and CFD Analysis

Abstract

The complex hydrodynamics of three-phase (gas-liquid-solid) fluidized beds are not well understood due to complicated phenomena such as particle-particle, liquid-particle and particle-bubble interactions. In the present work both experimental and computational studies have been carried out on two and three dimensional fluidized beds to characterize there hydrodynamic behavior. Air, water and low density solid particles have been used as the gas, liquid and solid phase to analyze the system behaviors. Eulerian multi-phase model has been used to simulate the system by using the commercial CFD code ANSYS Fluent 13.0. Gidaspow and Schiller-Neumann drag models have been used to calculate inter-phase drag force. Two-equation standard k-ε model has been used to describe the turbulent quantities. CFD simulation of three-phase fluidized bed systems with a distributor plate is not seen in literature. In the present work fluidized bed with distributor having orifice diameter 0.002 m has been studied. Result obtained from the simulation shows that fluidized bed with distributor has higher values of bed expansion and gas holdup compared to that of fluidized bed without distributor plate. It is also observed that in the bed having distributor the velocity magnitudes of solid particles, the liquid and gas phases are high and more fluctuating than in the bed without distributor. Simulation result obtained from CFD simulation with low density solid material is found agree with the experimental finding.