Numerical Simulation Of Micromixing Process In Rotating Packed Bed

It is well verified that the micromixing in the rotating packed (RPB) bed is extensively intensified and therefore it is of great potential as a novel reactor for the applications such as the synthesis of nanoparticles through reactive precipitation under fast reactions. Previous studies have proved that microimixing imposes a crucial role on the ulterior particulate properties and the particulate size distribution. The study on micromixing in RPB will hence advance the understanding of the mechanism of mixing-diffusion and the behavior of tiny liquid elements in the packing of RPB, both of which are the theoretical basis for synthesizing nanoparticles by precipitation in RPB.In this paper, on the basis of previous studies on mixcromixing and integrated with the observation results of fluid flow in RPB, an overall numerical model describing the turbulent micromixing phenomena and reaction process for film flow in the RPB was setup. The overall model consisted of two parts: the turbulent reactive mixing model within the packing voids and the turbulent reactive mixing model around on the surface of wire. During the overall simulation for a practical RPB with multiple layers, the two models were alternately used for every layer. The two models were verified by the data from open literatures and good agreement was achieved. The comparison illustrated that both of the models can reflect the actual process by analyzing the simulation results with good accuracy.The model was further applied to numerically simulate the turbulent mixing and reaction phenomena in RPB with the disazo coupling system. The micromixing process was successfully analysed and the numerical results were in fairly good agreement with the experimental results. It was found that the segregation index of micromixing was also in reasonable agreement with the experimental results. Further discussion on velocity modification was made and the numerical modeling with the proposed velocity modification provided great improvement. Stemming from present study, it is illustrated that the micromixing process can be numerically simulated with Euler based method. Present model can be used to predict the mixcromixing process.