Mixing Performance of Anchor and Helical Stirrer Blades for Viscous Fluid Applications

Abstract

Mixing performance is critical as it may influence the quality of the mixture and operation cost. In a viscous fluid application, the torque required to sustain the high viscosity is very important as it will affect the selection of motor power and cost. The final product of the mixing process is critically influenced by the blade design. The objective of this work is to study the mixing behaviour and the performance of different stirrer blade designs. Two different types of blades were designed and studied to determine how their distinct design features affected flow characteristics in a stirred tank. The liquid viscosity during the formation of grease is taken into account in the determination of viscous force. Fluid flow vector shows that the helical blade efficiently creates a more homogenous uniform mixing. It was found that the helical blade produced 0.25 Nm of torque, whilst the anchor blade produced 0.28 Nm of torque. These values are comparable with the calculation with 8 % error. Therefore, the helical blade can be used as an alternative for the anchor blade due to an efficient mixing process at a faster time and lower power consumption.