Research On The Multi-Scale Mixing And Reaction In A Rotating Packed Bed

Rotating Packed Bed (RPB) is a new highly effective contact device, which can strengthen the mixing and mass transfer. It is characterized by short residence time, better micro-mixing, higher mass transfer coefficient, and it has been used in many chemical and industrial processes. However, at the internal rotating packed bed, the research about the micro-mixing, the reaction process and mixed reactions coupling process appeared rarely. The principles and mechanisms about the processes of flow, mixing, diffusion and mass transfer have not understood. So, this study will help us to understand the various actions of the reactants in the rotating bed.In this paper, we through the analysis of mixing and reaction in the RPB, then get in the physical model about the pure mixing and mixed reactions coupling process. Considering the structure characteristics of the packing space and packing wire mesh, using rectangular equation describe packing space and using polar coordinate equation describe the flowing process on the wire mesh. Combined early experimental studies, we study the mixing and reaction process of the reactant film at the different areas in the RPB. Contrast with the simulation and experimental value, we can indirectly determine the film thickness.Through the numerical simulation, we obtained the regularity for change of reactant concentration, reaction products concentration and the integrating index at the different film thickness, different volume ratio and different feeding concentration. Also, we get he residence time, turbulence dissipation rate, the micro-mixing time, all of this has consistent with the experimental value.The study mainly found:there exists different regions of micro-mixing at different rotating speeds, and the segregation index, the mixing time, the turbulent kinetic energy dissipation rate at different rotating speeds show some of the multi-scale phenomenon. The special structure of the RPB strength the transfer and reaction process greatly, and improving the micro-mixing. The regularity for change of reactant concentration and reaction products concentration can provide the help for the optimization of the structure and performance of the RPB. The results enrich the understanding of the micro-mixing and mass transfer in rotating packed bed, and will provide a solid basis for future research.