CFD geometrical optimization to improve mixing performance of axial mixer

Abstract

Although various axial static mixers have been proposed, their commercialization have been hindered by their high pressure drop characteristic and the limited operating conditions where a wide frequency range of input disturbances cannot be filtered. The static “Time-Difference-Type Mixer (TDM)” is a new practical axial mixer that effectively reduces the intermittent variation of the mixture concentration. In the present study, the TDM was modified to decrease the pressure drop and smoothen the outlet concentration profile. The geometry of the element tip was modified based on the results of CFD simulation that were successfully validated by the corresponding experiments, with the purpose of reducing the flow resistance. A decrease in the pressure drop of nearly 40% was thus achieved. The concentration profile at the outlet was also substantially smoothened using an arrangement of the branch paths of the mixer that reduced the differences among the arrival times of the mixture through increased upstream spacing of the branch paths. The performance of the TDM was sufficiently optimized to make it commercially viable.