An Experimental Study on the Mass Transfer Rate of Droplets in Annular Two-Phase Flow

Abstract

Deposition rate of droplets in annular flow was measured to elucidate the effect of the shape of flow obstacles that were placed in a flow channel. In the present experiments, the test section was a vertical round tube of 5mm in inside diameter, air and water were used as test fluids, and double film extraction technique was adopted for the measurement. Seven flow obstacles were tested; three obstacles were tubular in shape while other four obstacles were also cylindrical but the cross-sectional areas were varied smoothly in the axial direction. It was revealed that the deposition rate of droplets markedly increased if the present small flow obstacle was placed in the test section tube. The increasing rate was dependent primarily upon the cross-sectional shape of flow obstacle at the maximum cross-sectional area.