Effects of blade structures on the dissolution and gas-liquid mass transfer performance of cup-shaped blade mixers

Background: A mixer with the advantages of excellent mixing performance and easy manufacturing is widely needed in industrial applications. In this work, the solid-liquid and gas-liquid mass transfer characteristics of a cup-shaped blade mixer, which is obtained by cutting a 90 degrees stainless-steel elbow, are investigated. Methods: The effects of blade structure, blade angle, blade height, baffle presence, surface tension, and gas holding on mass transfer characteristics were investigated by the conductivity probe and the dissolved oxygen dynamic method. Significant findings: Results show that the solid-liquid and gas-liquid mass transfer performance is enhanced as the inlet area of the cup-shaped blade is increased and the optimum blade angles are 22.5 degrees and 15 degrees respectively. The solid-liquid mass transfer performance can be improved when the baffles are removed. The gasliquid mass transfer performance first deteriorates but then improves as the surfactant concentration is increased. Moreover, the mass transfer performance of the cup-shaped blade mixer is superior to that of the 45 degrees -pitched blade and Rushton turbine. Meanwhile, the correlations of the solid-liquid and gas-liquid mass transfer coefficients are obtained, which would provide insight for the industrial design, optimization, and scale-up of cup-shaped blade mixers for multiphase systems. (C) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.