Agitation of yield stress fluids in different vessel shapes

Abstract

The Agitation of yields stress fluids with a six-curved-blade impeller (Scaba 6SRGT) is numerically investigated in this paper. The xanthan gum solution in water which is used as a working fluid is modeled by the Herschel–Bulkley model. The main purpose of this paper is to investigate the effect of vessel design on the flow patterns, cavern size and energy consumption. Three different vessel shapes have been performed: a flat bottomed cylindrical vessel, a dished bottomed cylindrical vessel and a closed spherical vessel. The comparison between the results obtained for the three vessel configurations has shown that the spherical shapes provide uniform flows in the whole vessel volume and require less energy consumption. Effects of the agitation rate and the impeller clearance from the tank bottom for the spherical vessel are also investigated. Some predicted results are compared with other literature data and a satisfactory agreement is found.

Keywords

• Mechanical agitation
• CFD
• Yield stress fluid
• Flow pattern
• Power consumption