Convective Mixing and Chemical Reactions in T-shaped Micro Reactors

A theoretical and experimental study was performed on convective micro mixing in T-shaped micro mixers. In these devices symmetric laminar vortices are developing at low Reynolds numbers Re. The symmetry breaks up with increasing Re numbers. This leads to an enormous enhancement of the mass transfer in the mixing channel. Numerical simulations of the flow characteristics and mixing behaviour are confirmed by pH neutralisation and indication by Bromothymol Blue. The integral mixing quality in the micro mixer is measured with the iodide-iodatereaction (Villermaux-Dushman) and shows excellent values for high Re numbers. The comparison of the characteristic numbers in the mixer and the derivation of the Damköhler numbers Da demonstrate the benefits of miniaturisation. The shortening of the diffusion length in small channels and additional convective effects are leading to outstanding mixing results.