Optimization of Draft Tube Structure for the Pilot-Scale Airlift Reactors

The effects of draft tube structure on the performance of pilot-scale Internal Loop Airlift Reactors (IL-ALRs) were investigated by Computational Fluid Dynamic (CFD) simulations and experiments. The Euler-Euler two fluid model and the κ-e turbulence model were adopted in the CFD model to predict the influence of draft-tube structure on the key flow parameters including gas holdup, gas distribution and liquid circulation velocity. A good agreement was obtained between the CFD predictions and experimental measurements. In present study, perforation was applied to the expanding section of the draft tube, and numerical results show the optimized structure can enhance the gas-liquid separation, promote the oriented liquid circulation, increase the superficial gas velocity and maximize the productivity. Further optimization was conducted on the perforated design based on the CFD simulation.

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