Cocurrent downflow of air and water in a two-dimensional packed column
Article first published online: 17 JUN 2004
Copyright © 1986 American Institute of Chemical Engineers
Volume 32, Issue 10, pages 1677–1689, October 1986
How to Cite
Christensen, G., McGovern, S. J. and Sundaresan, S. (1986), Cocurrent downflow of air and water in a two-dimensional packed column. AIChE J., 32: 1677–1689. doi: 10.1002/aic.690321011
- Issue published online: 17 JUN 2004
- Article first published online: 17 JUN 2004
- Manuscript Revised: 28 JAN 1986
- Manuscript Received: 5 NOV 1985
Multiple hydrodynamic states were observed during cocurrent down-flow of air and water under trickling flow conditions in a packed bed of rectangular cross section. Although the multiplicity was exhibited by both pressure gradient and liquid holdup, the pressure gradient showed the largest variations at identical conditions. The multiplicity is interpreted as being due to the liquid flowing in two different modes, namely, film flow and rivulet flow.
The characteristics of pulsing flow in a packed bed of rectangular cross section were found to be appreciably different from those reported in the literature for flow in small-diameter cylindrical columns. The most significant observation in the packed bed of rectangular cross section was that the pulses did not always span the column cross section, unlike the case in small-diameter columns. The lower pressure drop and pulse velocity in the packed bed of rectangular cross section are believed to result from the bypassing of gas around the edge of the pulses. The location of the pulses was found to depend on the quality of gas and liquid distribution at the top of the column, and the shape of the top surface of the packing. A distributor configuration in which the gas was injected directly into the bed was found to be the most desirable, and is recommended in industrial practice.