2007 Volume 21 Issue 4 Pages 421-427
An experimental investigation was performed to clarify the effect of addition of surfactant on the reduction in pressure drop for solid-liquid mixtures flowing through a vertical pipe. Initially, the pressure drops were measured under various operating conditions for the surfactant-added single phase water flowing through a vertical pipe. In the region of high Reynolds number, the pressure drops were much smaller than those of the flow without the surfactant. The surfactant in water was considered to form many rod-like micelles which tend to stand in each stream line, and accordingly to keep the flow against the transition to turbulent flow. Secondly, the similar examination was carried out for solid-water two phase flows. It was consequently concluded that the addition of the surfactant was also useful enough to reduce the pressure drops of the two-phase flows while the effect was not so remarkable compared with the case of single phase flow.
