Effect of Internal Diameter of Pipe on Velocity Distribution for Gas–Liquid–Solid Three-Phase Pipe Flows

Abstract Subsea minerals have been found in the deep water within Japan’s exclusive economic zone. However, the development of subsea minerals has not reached the commercialization stage because many technical issues still need to be addressed. One of the promising lifting methods is a gas lift pumping system. For the gas lift pumping system, the internal flow in pipes is a gas–liquid–solid three-phase flow. Estimating the velocity of each phase is an essential technique for designing and operating the system. However, studies focusing on the velocity of each phase for three-phase flows are few and it is not clear that the effect of internal diameter of pipes on the correlation for the gas and solid velocities in three-phase flows. We have experimented with three-phase flows for the pipes of 26, 41, and 52 mm in internal diameter, and obtained data on the volume fractions of each phase. To investigate the effect of internal diameter on the correlation for gas and solid velocities, we experiment with three-phase flows using the pipe of 79 mm in internal diameter and obtain a new dataset for large diameter. Then, we analyze the data obtained from the present and previous experiments. When the ratio of particle diameter to pipe diameter is more than about 0.15, the distribution parameter in drift flux model is affected by the existence of solid particles. The solid velocity increases linearly with increasing liquid velocity in three-phase flows. The effect of internal diameter on the distributions of liquid velocity or solid volume fraction is small.