Studies On The Gas Pressure Drop Performance Of Cross-flow And Countercurrent-flow Rotating Packed Bed

Cross-flow and countercurrent-flow rotating packed bed (RPB) has been applied to theprocesses of gas-liquid contacting, such as gas absorption, stripping and dedusting, etc. Gaspressure drop of an RPB involves in the transport power of gas and is an essential indicatorfor designing or choosing the type of RPB. According to the literatures, models contain ofsome parameters related to the construction and size of RPB directly. That results pooruniversality of these models and little guiding significance for engineering application. Toaddress this problem, a cross-flow RPB and a countercurrent-flow RPB whose rotors’specifications are almost the same are developed. Modeling and experimental studies of gaspressure drop of cross-flow and countercurrent-flow RPB are carried out by using highgravity factor, gas velocity, liquid spraying density as factors, aimed to lay the foundation forthe type choice and engineering design of RPB.Models of gas pressure drop of RPB have been studied by segmenting in which the totalpressure drop can be divided into pressure drop of gas inlet section, pressure drop caused bycentrifugal force, force of friction, changes in cross section and liquid introduction, andpressure drop of gas outlet section. By going through, models are obtained:Experiment studies on gas pressure drop of cross-flow and countercurrent-flow RPB arecarried out using air-water system. The experimental results show that: The gas pressure drop increases with increasing of high gravity factor and gas velocity; Liquid spraying density haslittle effect on pressure drop; The pressure drop of dry bed is lower than that of wet bed. Themodels are fitted using experiment data. The model of gas pressure drop of cross-flow RPB isobtained by fitting the coefficients of cross-flow RPB. Compared with the experimental dataand the model calculation value, the mean error of relational of gas pressure drop ofcross-flow RPB is within±16%and experiment results can be reflected well by the model.The pressure drop increases with high gravity factor and gas velocity; There is thephenomenon of flooding; The pressure drop of dry bed is lower than that of wet bed when thehigh gravity factor is no more than38and the pressure drop of dry bed is bigger when thehigh gravity factor is over38. The model of gas pressure drop of countercurrent-flow RPB isobtained by fitting the coefficients of countercurrent-flow RPB. By comparing with theexperimental data and the model calculation value, the relational of gas pressure drop ofcountercurrent-flow RPB is fitted well that mean error is no more than±20%.Pressure drop of cross-flow is compared with that of countercurrent-flow RPB. Theresults show that: The pressure drop of countercurrent-flow RPB is lower than that ofcross-flow RPB with the same conditions; The growth trend of gas pressure drop along withhigh gravity factor and gas velocity of countercurrent-flow RPB is much faster than that ofcross-flow RPB, especially the trend with the gas velocity; Cross-flow RPB is better when thegas flow rate is large enough.In this study, t Modeling and experimental studies of gas pressure drop of cross-flow andcountercurrent-flow RPB are carried out. Comparison studies are also done. The resultsobtained can play important roles in the type choice and engineering design of RPB.