TWO-PHASE FLOW DISTRIBUTION IN PARALLEL VERTICAL CHANNELS FED BY A VARIABLE DEPTH PROTRUSION HEADER

In the present study phase distributions in parallel upward channels fed by a cylindrical horizontal header is experimentally investigated. A new fitting solution to be inserted in the header are been developed based on previous experiments by the Authors. The fitting geometry belongs to the family of the protruding pipes but the protruding depth has been varied along the header to cope with expected liquid and gas mass flow rate in the parallel channels. In this study the operating conditions, evaluated at the distributor inlet, covered the following ranges of gas and liquid (air and water close to atmospheric pressure) superficial velocity: Vsg=1.50÷16.50 m/s and Vsl=0.20÷1.20 m/s, respectively. Intermittent flows (plug, slug) and annular flow were visually observed. The new header fitting demonstrated to yield meaningful improvements in phase distribution in terms of either dimensionless liquid and gas flow ratios or standard deviation of phase flow ratio, when compared to constant depth protruding pipes.