A CFD study of the effect of ridge baffles on the hydrodynamic behavior in gas–solid fluidized system

Abstract

This study investigates the impact of ridge baffles on the hydrodynamics of cold hydrogenation fluidized bed reactors (FBRs) using Euler–Euler simulations. The model was validated by comparing predicted pressure drops and bed expansion ratios with literature results. A comparative analysis was performed on 3D FBRs with and without ridge baffles in terms of solid holdup, gas–solid velocity distribution, pressure fluctuation, and residence time distribution (RTD). Ridge baffles were found to effectively break up large bubbles and enhance gas–solid contacting efficiency, as demonstrated by visual observations, reduced pressure standard deviations, and increased bubble frequency. Furthermore, baffled FBRs demonstrated a much narrower RTD and shorter tails than the free FBR, indicating the ability to suppress gas-phase back-mixing through the inhibition of solid back-mixing and improvement of stripping efficiency. Based on sensitivity analysis of the number of baffle layers, one single layer of ridge baffles is the optimal design under the current simulation.