Computational Study of Improved yet Easy-to-Manufacture Micro-mixer Design for Chemical Processes and Pharmaceutical Industries

摘要

Micro-channel T-junction design is widely used for passive mixing processes, because it is easily manufactured and does not require additional energy or mechanical devices for mixing; however, since small scale mixing depends mainly on molecular diffusion, a relatively long channel is necessary to achieve the desired mixing. To enhance mixing, various approaches have been introduced, e.g., the introduction of mechanical, magnetic, acoustic, thermal, or electrical disturbances. But, most impose a requirement of additional external energy and auxiliaries which increase the complexity. Furthermore, other approaches to intensify the mixing and reaction processes is by modifying channel design into complicated geometrical shapes, e.g. herringbone, grooves, staggered, baffles etc. This, however, increase the complexity in the manufacturing process which is impractical for some applications. There is thus a need for an improved, yet easy-to-manufacture, design for mixing in a micro-channel T-junction. In view of improving the mixing performance whilst keeping the simple manufacturing process, we propose to utilize the presence of secondary flow induced by curve geometry in micro-wavy-channel T-junction. Here, the mixing performance of micro-wavy-channel T-junction is compared with that of conventional straight T-junction and complicated herringbone micro-channel via computational fluid dynamics simulation. The results suggest that by carefully controlling the frequency and amplitude of wavy channel, the optimum mixing can be achieved at relatively low manufacturing cost.