Modification of impeller blades for the efficient mixing of particulate suspensions in a stirred tank

Abstract

The fractal arrangement of perforated holes were introduced in the impeller blades for the suspension of solid particles in a stirred tank. The mixing characteristics of solid-liquid two phases in a stirred tank with a fractal arrangement perforated impeller (FAP impeller) were investigated. Results indicated that incorporating fractal arranged perforated holes in the impeller blades resulted in a reduction in power consumption (P) compared to conventional designs under the same agitation speed. Moreover, a rise in the iteration quantity of fractal arranged perforated holes in impeller blades resulted in higher power consumption and power number, but still lower than those observed with conventional designs. FAP impeller enhanced turbulent intensity, increased shear effect on the fluid, minimized trailing vortex dimension behind the impeller blades, and promoted the axial circulation of solid particles, ultimately leading to the better suspension quality of solid particles compared to pitched blade impeller at the constant P. The above phenomena became increasingly evident as the iteration number in the fractal arranged perforated holes in the FAP impeller blades increased.