Flow Characteristics in Vertical Upward Gas-Liquid Two-Phase Flow with Surfactant Additives
-1st Report, Pressure Drop Reduction -

Abstract

To investigate the effect of surfactant additives on the pressure drop and the liquid holdup in vertical upward two-phase flow, experimental studies were conducted for two types of surfactants: one was n-hexadecyltrimethylammonium chloride mixed with a counter-ion sodium salicylate (CTAC) acted as a foaming agent and the other was sodium oleate (SO) acted as a non-foaming agent. The surface tension was reduced to 50% of water by the addition of each surfactant. The pressure drop reduction (PDR) was achieved up to 90% by the addition of CTAC at low liquid volumetric flux conditions. The addition of CTAC caused the reduction in liquid holdup in the range of the gas volumetric fluxes between 0.2 and 10 m/s. The PDR was mainly caused by the reduction in the gravitational pressure gradient due to the formation of the liquid phase containing fine bubbles. When SO was added, the PDR of 5-10% was obtained. The main cause of PDR was the reduction in the frictional pressure gradient.