Computational investigation of hydrodynamics and solid circulation in fluidized bed column

Abstract

Gas–solid fluidized beds are commonly used in applications where high heat and mass transfer is required, which are influenced by the quality of mixing in the bed. This largely depends on the design of gas distributor and operating conditions. Hence, in the current work, the influence of distributor design on hydrodynamics in a 3D bubbling fluidized bed column is investigated using CFD. Here, Euler-Euler model is used to predict the flow field. The predicted bed pressure drop is analyzed for various superficial gas velocities, and it has been validated with the experimental data. The solid circulation rate is calculated to quantify the flow field, and it is improved by incorporating various gas distributors such as flat, convex and concave perforated plates. The magnitude of solid circulation rate is found to be the highest for convex plate, showing that it is more advantageous than the conventional flat plate configuration. Further, the effect of operating temperature and the influence of baffle on gas–solid flow are analyzed. The rate of solid circulation is found to decrease with increase in temperature and in the presence of baffle.

Keywords:

• CFD
• Fluidized bed
• Gas distributor design
• Hydrodynamics
• Solid circulation