Investigation of gas-liquid mass transfer and power consumption characteristics in jet-flow high shear mixers

Experimental measurements were performed to systematically investigate the effects of operating conditions and structural configurations of the rotor-stator head on gas-liquid characteristics (volumetric mass transfer coefficient, gas hold-up and bubble dispersion) and power consumption of the jet-flow high shear mixer (HSM). Gas hold-up distribution, bubble dispersion and flow fields under different structural configurations were also analyzed and verified by the computational fluid dynamics (CFD). The results indicated that the gas-liquid mass transfer performance and power consumption in jet-flow HSM were significantly impacted by the structural parameters involving blade angle, blade arc and stator bottom opening. Increasing gas flow rate or reducing surface tension could enhance the gas-liquid mass transfer performance to some extent. In addition, gas hold-up distribution and bubble dispersion in the gas-liquid system were more uniform with the modified configuration of the rotor-stator head. The dimensionless correlations were established based on the experimental data to predict Pog and kLa in gas-liquid operation of the jet-flow HSM: Po-g = 0.958 center dot(sin theta)(1.567)(D/(D-s - D-b))(-0.164) with the standard deviation (sigma) of 16%; ShL = 7.92 x 10(4)center dot Fl(Q) (0.38) Fr-0.69 Po-g(0.29) with sigma of 17%. This work can provide useful guidance on scaleup design and optimization of the jet-flow HSM to intensify the transfer properties for gas liquid operation systems.