Investigating the power consumption for the intensification of gas dispersion in a dual coaxial mixer containing yield-pseudoplastic fluids

Abstract

Coaxial mixers with double central impellers and an anchor have demonstrated promising results in the intensification of gas dispersion in complex fluids. While previous studies have evaluated power consumption for gas dispersion in pseudoplastic fluids, no investigation has been conducted on aerated dual coaxial mixers containing pseudoplastic fluids with yield stress. This study aimed to evaluate the power consumption of the aerated double coaxial mixer under various operating conditions, including anchor and central impeller speed, rotational mode, pumping direction, and aeration rate. Experimental power consumption measurements were performed for both gassed and ungassed systems. Our findings showed that the anchor power contributed substantially less to overall power consumption than the central impellers. The counter-rotational mode used more power than the co-rotational mode due to the opposing flow created by the rotation of the central impellers and anchor impeller. The co-rotational mode had a higher relative power demand (RPD) than the counter-rotational mode, with the upward pumping mode of the central impellers yielding the highest RPD values. The modified Jamshidzadeh's correlation successfully predicted the impact of the anchor speed, central impeller speed, and aeration rate on power consumption for the investigated double coaxial mixers containing the xanthan gum solution.