CFD of multiphase flow in packed-bed reactors: II. Results and applications

Numerical simulations of multiphase flow using the k-fluid CFD model described in Part I of this issue are presented for packed beds at various operating conditions. Both steady-state and unsteady-state (e.g., periodic operation) feed conditions were studied numerically. Predictions of the k-fluid CFD model are comparable with the experimental data in the literature for liquid upflow in a cylindrical packed bed. In addition to the mean porosity and the longitudinally averaged radial porosity profile, the variance of the porosity distribution is needed for predicting the probability density function of the sectional flow velocity. In the trickling flow regime, the k-fluid CFD model provides reasonable predictions of the global liquid saturation and the pressure gradient. Relevant applications of the k-fluid CFD model are identified in quantifying the relationship between bed structure and flow distribution in various-scale packed beds. The combined flow-reaction modeling scheme is proposed through the “mixing-cell” network concept, in which the k-fluid CFD simulation can provide the information on sectional flow distribution.

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