Separation of Gas from Downward Gas-Liquid Two-Phase Flow Using a Y-Junction of Poor Wettability

A Y-junction made of transparent acrylic resin was placed vertically downward. One side of the Y-junction was coated with repellent to change its wettability. As a result, the wettability of that side became poor, while the wettability of the other side was originally good. Straight pipes were connected to the main pipe and two branches of the Y-junction. A downward air-water two-phase flow was introduced into the main pipe. The air attached preferably to the poorly wetted side of the main pipe and entered into the poorly wetted branch. When the superficial velocities of air and water, j_g and j_w, were less than their respective critical values, air was completely distributed into the poorly wetted branch, and thus, the gas separation efficiency was 100%. An empirical equation was proposed for predicting the critical values of j_g and j_w.