Numerical investigation of hydrodynamic performance and power consumption in stirred reactors with perforated Scaba 6SRGT impellers for non-Newtonian fluid

The present study aims to further understand the effect of perforated Scaba 6SRGT impellers on stirring performance and impeller power consumption by numerically investigating the hydrodynamic properties of non-Newtonian fluids in a three-dimensional stirred reactor. After model validation, the fluid velocity, stagnant region dimensionless volume, and impeller power consumption are quantitatively analyzed under the conditions of influencing parameters, including blade perforation pitch, ratio of distance between adjacent perforations, and perforation arrangement. The results reveal that the range of distribution of acceleration and peak velocity of the fluid along the radial appear in regions lower and larger than the dimensionless radius of the impeller (|r/R| = 0.45), respectively. Increasing the perforation pitch from 14 to 20 mm increases fluid velocity from 0.284 to 0.305 m/s and power consumption from 26.99 to 27.25 W, while reducing the stagnant region volume from 16.76% to 14.71%. The fluid velocity and impeller power consumption slightly increase with the ratio of distance between adjacent perforations. Circular-shaped middle perforations yield higher fluid velocities and vorticity compared to lozenge-shaped ones. The highest and lowest power consumptions are obtained by circular–circular–circular and lozenge–lozenge–lozenge perforation shape arrangements with values of 27.25 and 26.9 W, respectively.