Enhancement of gas-liquid mass transfer in curved membrane contactors with the generation of dean vortices

The generation of Dean vortices in the membrane contactor is regarded as one of the critical technologies for gas-liquid mass transfer enhancement at low liquid Reynolds number. In this work, the gas-liquid mass transfer enhancement by Dean vortices in the curved hollow fiber membrane contactors is rapidly characterized based on the flux balance of gas across the membrane and dissolved in liquid. The effects of Reynolds number, curved diameter, liquid viscosity and rheology on the gas-liquid mass transfer enhancement with different curved shapes are systematically determined. The gas-liquid mass transfer correlations are proposed to describe the enhancement effect of Dean vortices on gas-liquid system with different viscosities. At the helical diameter of 6 mm and Reynolds number of 308, the enhancement factor is up to around 2.5. Furthermore, the trade-off relation between gas-liquid mass transfer intensification and energy consumption across the curved membrane contactors is investigated. The liquid velocity profile is also obtained by the finite element numerical simulation with COMSOL Multiphysics software to evaluate the Dean vortices intensity generated in different curved shapes, which agrees well with the experimental results.