Study On Fluid Flow Characteristics Of Gas-Liquid-Liquid System

The gas agitation can promote the mixing between continuance phase and dispersed phase. At the same times ,droplets of dispersed phase can be broken up to a small one. The static mixer can provide a uniform resistance to the three phase fluid flow. Therefore, a homogeneous dispersion of fine drops and air bubbles in water is possible.First of all, the fluid hydrodynamics and mass transfer characteristics on gas-liquid-liquid system in gas agitated extractor with static mixer was experimentally investigated. The experimental measurements of gas holdup, the dispersed phase holdup and mass transfer coefficient in operation condition were carried out in the system of air, water and kerosene.It was found that gas holdup, kerosene holdup and mass transfer coefficient strongly depend on superficial velocity of air ,water and kerosene as well as structure of extractor. The experiment result was shown that the increase of superficial velocity of gas ,water and kerosene can promote and enhance the mass transfer in liquid phase, because the gas bubble passed through the liquid phase can promote the turbulence and circulation in the liquid phase. The turbulence of liquid can effectively break up the stream of dispersed phase into small droplets and increase the contact surface area between liquid phase. Therefore the gas holdup, dispersed phase holdup and mass transfercoefficient will increase with an increase of superficial velocity of the gas ,water and kerosene.However ,overmixing of liquid in extractor could lead to emulsification and extension of the separation time of two phases. As result, dispersed phase holdup and mass transfer coefficient remain constant or even decrease due to the high superficial velocity of gas and liquid.Secondly Based on the above-mentioned research work, some effected factors on the operation process were discussed and theoretical analysis were made.Finally experimental evaluation about gas holdup ,dispersed phase holdup and mass transfer coefficients were proposed according to the analysis of mass transfer theory. The experiment result was in agreement with theoretical analysis.