Effect of impeller blade curvature on the hydrodynamics and power consumption in a stirred tank

Abstract

The performance of curved bladed turbines (CBTs) for the agitation of Newtonian fluids in cylindrical tanks is investigated. The efficiency of CBT is compared with that of the standard Rushton turbine. Also, effects of the blade height of the new designed impeller are highlighted. The computational fluid dynamics (CFD) study is performed to observe the axial, radial and tangential components of velocities, flow patterns and power consumption. The obtained results revealed that the increase of blade curvature reduces the power consumption. Also, a slight decrease of power number is observed in the turbulent flow regime within unbaffled tanks. In a comparison between the cases studied, the best axial circulation of fluid is given by the impeller with flat blades. The increase of the height of curved blades has generated a stronger tangential flow and enhanced the axial movement of fluid particles, but with further penalty in power input.

Keywords

• mechanical agitation
• curved bladed impeller
• cylindrical tank
• hydrodynamics
• power consumption