Enhancement investigation of mass transfer and mixing performance in the static mixers with three twisted leaves

Abstract

Abstract The mass transfer and mixing performance in the static mixers with three twisted leaves (TKSM) were investigated by the computational fluid dynamics coupled population balance model. A high-precision and efficient gas-liquid two phase model were evaluated by considering several drag models based on experimental bubble size distributions. The bubble size prediction matched well with experimental data and the mean relative error of Sauter mean diameter (d 32) between the prediction and experiment values is 4.93 %. The drag correction factor considering hindering effect of small bubbles can improve the accuracy of cumulative probability distribution (CPD) prediction by 10.06 %. Bubble breakup capacity is quantized via gas-liquid interfacial area, and an empirical correlation between Eo and bubble aspect ratio (γ) have been proposed to predict morphological characteristics of bubble swarms. The effect of liquid Re on the mass transfer rate is much more significant than that of gas volume fraction (α d). The coefficients of variation profiles show that RL-TKSM has better mixing efficiency compared with LL-TKSM and perfect mixing could be achieved after seven mixing elements. The micro mixing efficiency of RL-TKSM is 1.06–1.14 times that of LL-TKSM, which indicates that RL-TKSM has excellent mixing and mass transfer performances.