The effect of packing and its voidage on the hydrodynamic characteristics of co-current downward liquid-liquid system (CCDLLS) was studied using water and three different oils (exxsol, kerosene and white oil). Two flow regimes, homogeneously dispersed oil regime and heterogeneously dispersed oil, were observed with the total pressure drop showing a minimum at the regime transition velocity. Depending on the packing, frictional pressure drop either shows a minimum or monotonically increases with water velocity. Low-density oil results in higher holdup and correspondingly higher frictional pressure drop. Higher dispersed phase holdup is obtained by using a low voidage packing. Semi-empirical/empirical equations are proposed to predict the frictional pressure drop and phase holdup.

使用水和三种不同的油（exxsol、煤油和白油）研究了填料及其空隙率对并流向下液-液系统 (CCDLLS) 流体动力学特性的影响。观察到两种流态，均匀分散的油态和非均匀分散的油，总压降在流态转换速度下显示最小值。根据填料的不同，摩擦压降随水流速度呈最小或单调增加。低密度油会导致更高的滞留率和相应更高的摩擦压降。使用低空隙率填料可以获得更高的分散相滞留率。提出了半经验/经验方程来预测摩擦压降和相保持率。