Numerical Simulation On The Jet Loop Reactor

Jet loop reactor, as a new, efficient and multiphase reactor, combined with the technical advantages of jet and loop current. It has a series of advantages, such as good mixing effect, high mass transfer efficiency, low energy consumption, strong resistance to impact load capacity, apt to operate and maintain etc. Therefore, it is widely applied to biology, environmental and chemical process, and chemical industry. In the liquid-solid two-phase reaction, solid phase disperse into liquid phase, flowing with liquid phase. Heat transfer and mass transfer happen at the same time. The suspension state of solid phase has a significant effect on the reaction process. And the distribution changes of solid holdup in the reactor have an important influence on the two-phase reaction.In this paper, the liquid-solid up-jet loop reactor was taken as the study object. The distribution of solid holdup in the reactor was investigated by applying a combination of numerical simulation and experiment. In the cold model experiment, the solid holdup along the radial direction at each flat in the draft tube was measured by direct sampling method, when the nozzle velocity was1.5m/s and the solid particle average size was0.15mm. With the help of the Eulerian Model of multiphase flow model, the flow field between two-phase in the reactor was simulated and calculated at different nozzle velocities and different particle sizes by using the Computational Fluid Dynamics software FLUENT. The simulated results were fitted well with the experimental ones, and verified the feasibility of the model.After analyzing the results, we found that the distribution of solid holdup in the reactor was related to the nozzle velocity. Along the axial of the draft tube, the solid holdup distribution showed a shape which is high in the middle and low on the sides. On the position where the solid holdup showed the highest value, liquid velocity kept stable. When the particle average size was0.15mm, with the increase of nozzle velocity, the position where the solid holdup distribution obtained the maximum value approached to the top of the draft tube slowly.When the nozzle velocity was1.5m/s, with the particle average size increasing, the maximum value of solid holdup increased and the position where the maximum value achieved gradually approached to the top of the draft tube. With increasing height, solid holdup distribution along the radial direction changed from "M" shape to parabola.