CFD simulation of gas holdup and gas-liquid flow in bubble columns
Journal Title: Science Paper Online - Year 2008, Vol 3, Issue 12
Abstract
The gas dispersion and flow velocities in bubble columns with single-stage gas distributor, double-stage gas distributor and with flow draft, respectively, are numerically simulated by using computational fluid dynamics (CFD) in this paper. The simulation results show that, with the increase of the gas inlet flow rates, the global gas holdup increase in the bubble column while the uniformity of the gas holdup distribution decrease. Flow pattern in bubble column can be divided into transient flow regime and fully developed flow regime. The average holdup in horizontal plane increases with the axial height in transient flow regime while almost keeps unchanged in fully developed flow regime. The dividing line position of the two flow regime affects by the structure of the bubble column while almost not by the gas inlet rate. Under the same operating conditions, the global gas holdup of double-stage gas distributor bubble column or the flow draft bubble column lower than that of single-stage gas distributor bubble column. The double-stage gas distributor bubble column can improve the uniformity of oxygen distribution for oxidation reaction system compared with the single-stage gas distributor bubble column. The flow draft can improve the liquid circulation in the bubble column.
Authors and Affiliations
LI Liangchao, Jiajun WANG, Xueping GU, Lianfang FENG
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