Flow Distribution in Countercurrent Flow Structured Packing Bed via Computed Tomography

Shaibal Roy1, M H Al-Dahhan1, M P Dudukovic’1, Thomas B Skourlis2, Fritz M Dautzenberg2

1 Chemical Reaction Engineering Laboratory, One Brookings Drive, Campus Box 1198, Washington University, St. Louis, MO 63130, muthanna@che.wustl.edu, Tel: (314) 935 7187; Fax: (314) 935 7211

2 ABB Lummus Global, Inc., 1515 Broad Street, Bloomfield, NJ 07003-3096

ABSTRACT

Computed Tomography (CT) is known to be a viable technique for determining flow distribution in multiphase flow systems. In this study a newly developed gamma ray computed-tomography was implemented on a mock-up system of countercurrent two-phase (air-water) flow through a 1 ft diameter of corrugated structure as the packing. A spatial resolution of ~ 2.5 mm was found to be achievable during the validation of the unit.

Experiments were carried out with liquid velocity ranging from 0.6 to 2.5 cm/s and gas velocity ranging from 0-10 cm/s. Within the gas and liquid flow ranges investigated, the change of gas holdup with respect to gas velocity was found to be minimal. However, a good liquid distribution was observed, as manifested by maldistribution factor. The pressure drop across the structured packing at experimental flow conditions was very low, less than 1 mm of water/meter of the bed.

Keywords Computed Tomography, Structured packing, Holdup, Flow distribution