Effect of stator geometries on flow fields and mixing performance for viscous fluids

Abstract

High shear mixers (HSMs) find wide applications in industrial processes where intense mixing and dispersion of fluids play a vital role. In this work, the flow fields and mixing performance is analyzed in different batch HSMs with varying stator heads, such as disintegrated, slotted, and mesh. Further, the effect of viscosity, flow behavior and rotor speed on hydrodynamics and mixing performance is assessed through numerical investigations. The turbulent flow fields and mixing enhancement are characterized using standard k-ɛ turbulence model with multiple reference frames approach for various HSMs. The turbulent statistics like turbulent kinetic energy are found to be maximum in the stator hole region and varied with flow behavior. The energy dissipation within the rotor vicinity is found higher for mesh head geometry followed by disintegrated and slotted heads. The effect of tracer injection locations is evaluated to gain comprehensive information on the mixing performance inside the mixing tank. Mixing time (t95) was evaluated and correlated with the existing results. For viscous fluids, complete mixing is hard to achieve due to the presence of cavern effect in smaller stator holes HSM. Moreover, the results provided guidance for further selection, design and development of HSMs for process industries. © 2021 Elsevier B.V.