Investigation of pressure drop in a cocurrent downflow three-phase moving bed

Based on a self-established cold-flow experimental device, the pressure drop in a cocurrent downflow three-phase moving bed was investigated under a wide range of gas, liquid, and solid flow rates during dynamic and steady-state operation. The results showed that for the startup of the bed, since the first bed layer packed by fall-falling of particles had lower voidage, it would take at least one bed volume time to make the voidage in the bed reach the steady-state. Under steady-state conditions, the pressure drop increased with the increase of gas and liquid mass flow rates, liquid viscosity, and decreased with the increase of solid flow rate. Furthermore, it was found that the liquid distribution became more uniform due to particle movement. The experimental data obtained in this study was used to develop a correlation to predict the pressure drop in a three-phase moving bed with an average relative error of 9.32%.