CFD simulation and experiment of residence time distribution in short-contact cyclone reactors

• Gidaspow drag force model is the most suitable drag model for the reactor.
• The simulated results are accurate when the restitution coefficient is 0.95.
• The catalysts had good contact effect with reactants and separated with products completely.

An Eulerian–Eulerian two-fluid model that incorporated the kinetic theory of granular flow was used to describe the gas–solid two-phase flow in short-contact cyclone reactors. By comparing with the experimental data, we found that the simulated data calculated with Gidaspow drag force model performs best. Besides, when the restitution coefficient is 0.95, the simulated results fit the best with experimental results. Then we mainly focused on the component concentration distribution and residence time distribution characteristics in this paper. The species transport method was validated for the prediction and a video camera and the colored particle tracer method were employed in the experiments. The results indicate that the vacuum gas oil (VGO) and catalysts flow down spirally along the wall and the gasoline and coke + dry gas are mostly in the central part, so the VGO has more contact time with catalysts than other components. The simulated results show a good agreement with the experimental data.

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