CFD analysis of the hydrodynamic characteristics in a rotating packed bed with multi-nozzles

Abstract

Rotating packed bed (RPB) has been widely noted for its good mass transfer performance and tangible size savings, and its advantages are especially obvious in space-intensive scenarios, such as purification of natural gas on offshore platforms. Liquid maldistribution in RPBs has a serious impact on mass transfer performance. However, it is difficult to accurately obtain and predict the liquid flow characteristics and liquid distribution in RPBs by experimental methods. Therefore, the liquid flow characteristics and liquid distribution analysis of multi-nozzle RPBs based on computational fluid dynamics (CFD) models is performed in this paper. The simulation results indicate that increasing of the number of nozzles and nozzle width at two different rotational speeds increases the liquid holdup and decreases the degree of liquid dispersion. In addition, a liquid maldistribution index within RPBs is proposed and investigated. The circumferential distribution of the liquid becomes uniform as the number of nozzles increase, but the uniformity gets worse as the width of nozzle increases, under the same total liquid flow rate. The more the number of nozzles, the more uniform the overall liquid distribution; on the contrary, the larger the nozzle width, the more uneven the overall liquid distribution.