Investigation on pressure drop characteristic and mass transfer performance of gas-liquid flow in micro-channels

Pressure drop characteristics and mass transfer performance of gas-liquid two-phase flow in micro-channels with different surface wettabilities were experimentally investigated. Side-entry T micro-channel mixers made of glass and polydimethylsiloxane were tested. Frictional pressure drop was found to decrease as the hydrophobicity of the channel surface increased. The flow patterns observed in the experiment were classified as slug flow and continuous gas phase flows. The modified Hagen-Poiseuille equation and Lockhart-Martinelli model were developed to predict the pressure drop for these two types of flow, respectively. The effect of surface wettability was heuristically incorporated in the present models which can correlate well the experimental results. Mass transfer performance was studied by the physical absorption of oxygen into de-ionized water. The results show that the volumetric mass transfer coefficients in hydrophobic micro-channels are generally higher than those in hydrophilic ones. The empirical correlations of overall volumetric mass transfer coefficients were proposed.