Pipe Diameter Effect on the Two-Phase Flow Separator for Removal of Liquid in Horizontal Pipes

A pipe diameter effect on the two-phase flow liquid separation phenomenon by an annular type liquid separator is experimentally investigated, where this type of separator does not have any intrusive section inside the pipe. Past work demonstrated that a 2 cm diameter flow separator could effectively separate liquid from an annular flow regime without the use of intrusive devices in the main pipe. The current study examines the results of a 10 cm diameter pipe and compares to the 2 cm results previously observed. The separator consists of segments of Lucite tubing containing multiple holes in the separation sections. An experiment was conducted for a 10 cm inner diameter flow pipe and inlet two-phase flow regimes of stratified smooth, stratified wavy and annular mist are studied for superficial gas velocities from 0 to 8 m/s and superficial liquid velocities from 0 to 0.005 m/s. The number of holes, the pitch, and the shape of the holes in the wall of the separator were varied. The results show that the separation efficiencies were observed in the range of 80% to 100%, where the separation efficiency decreases with increasing superficial liquid velocity. Separation efficiencies of 100% were observed for stratified flow conditions. Separation efficiencies greater than 90% were usually observed for annular mist conditions. For stratified wavy conditions, separation efficiencies ranged from 80% to 100%. The separation efficiency does increase with the number of holes as expected. In comparison to the smaller 12 cm diameter test section, the results indicate the same trends, where the superficial velocities can be used as a first order scaling parameter for the separator.