Improvement of mass and heat transfer efficiency in a scale-up microfluidic mixer designed by CFD simulation

Due to scale effects, directly enlarging the size of the micromixer is an easy way to reduce the efficiency of mass and heat transfer in the continuous flow chemical process. It is urgently needed to solve the problem of mass and heat transfer efficiency of the scale-up mixer. A scale-up microfluidic mixer with a porous structure was designed to improve the mass and heat transfer efficiency using computational fluid dynamics (CFD) simulations. The effects of rotation angle, porosity, and baffle spacing were studied to optimize the mixer structure. Compared with the 1 mm mixer without structure, the scale-up mixer has a higher mixing efficiency and an 80% reduction in energy consumption at Re ≥ 700. A Nusselt number was used to evaluate the heat transfer efficiency of the mixer during fluid heating. The results show that the porous baffle promotes the generation of secondary flow and enhances the heat transfer effect, making its Nu increase by three times compared with the unstructured mixer. The scale-up microfluidic mixer with a porous structure can effectively improve the mass and heat transfer performance. This study can provide a reference for the design or development of a novel scale-up mixer.