Separation of a Two-Phase Slug Flow in Branched 90 deg Elbows

Novel experimental data for phase separation of air-water mixtures in horizontal 90 deg branched elbows are presented in this work. The branched elbows were formed by attaching a pipe to a 90 deg elbow on the side of maximum radius of curvature, and halfway between the inlet and outlet sections of the elbow. All three arms coming from the junction were in the horizontal plane. Both the branch orientation and branch diameter were varied. Three different branch/elbow diameter ratios were tested, as well as three different branch inclination angles. In addition, the static pressure was monitored at different points along the ramified elbow using a set of pressure transducers in order to analyze and associate the pressure drop with the phase separation. At the inlet section of the elbow, the two-phase flow pattern was mainly slug flow. Based on the experimental data, a correlation for the liquid phase separation is proposed. Finally, the volume-weighted phase separation in the branched elbow was compared with the phase separations on the T-junction, and it was found that in some cases the branched elbows have a similar performance to that of the T-junctions. [DOI: 10.1115/1.4001488]