Experimental and Numerical Investigation of the Characteristics of Novel Disc Turbines in Aerated Stirred Tanks

In this work, the gas dispersion and transport characteristicsof three different disc turbines, namely, parabolic disc turbine (PDT),novel swept-back parabolic disc turbine (SPDT), and staggered fan-shapedparabolic disc turbine (SFPDT), are characterized by experiments andtwo-fluid model/RANS simulations. The physical explanation of thesuperior power characteristics of SFPDT and SPDT is elaborated usingthe pressure distribution and drag force coefficient on a blade surface.Gas-liquid performance parameters such as critical dispersionspeed, relative power demand (RPD), and volumetric mass transfer coefficientare assessed under different conditions. The results show that SFPDTand SPDT can produce smaller flow separation regions and trailingvortices, resulting in smaller gas cavities under aeration conditions.SFPDT has the lowest critical dispersion speed under a high flow rate,while SPDT consumes the least power. Both SFPDT and SPDT exert roughly7% higher gassed power input than PDT under aeration conditions andhave higher efficiency on gas-liquid mass transfer than PDT.Moreover, empirical correlations from experimental data for SFPDTand SPDT are presented to provide a reference to the design of industrialstirred tanks.