Inclination effects on circumferential film flow distribution in annular gas/liquid flows

Measurements of the circumferentially resolved axial liquid film flow rate have been obtained for a 38 mm internal dia. pipe at inclinations of 0°, 20°, 45°, 70 and 85° from the horizontal. The method employed is based on that used by Butterworth, and consists of a film extraction technique which utilizes a unit with a wall that is porous over a sector of the pipe. Liquid entrained fraction was determined from the total film flow rate. Results show that the local liquid film flow rate is not symmetrical. Flow rates are higher on the lower part of the pipe. As the inclination angle deviates from horizontal, the film flow rate becomes systematically less asymmetric. There is not a strong dependence of the entrained fraction on pipe inclination. For the case when the pipe is horizontal, the circumferential variation of film flow rate is well predicted by a horizontal annular flow model. © 2007 American Institute of Chemical Engineers AIChE J, 2007