Downflow reactors, comparison

A model is presented to predict flow transition between trickling and pulsing flow in cocurrent downflow trickle-bed reactors. Effects of gas and liquid flow rates, particle size, and pressure on the transition are studied. Comparison of theory with published transition data from pilot-scale reactors shows good agreement. Since the analysis is independent of reactor size, calculations are extended to include large-scale columns some interesting observations concerning flow transition and liquid holdup are obtained. 

Wu Y, Khadilkar MR, Al-Dahhan MH, Dudukovic MP. Comparison of upflow and downflow two-phase flow reactors with and without fines. Ind. Eng. Chem. Res. 1996 35 397. 

Mills, T. L., E. G. Beaudry and M. T. Dudukovic. Comparison and Prediction of Reactor Performance for Packed Beds with Two-Phase Flow Downflow, Upflow and Countercurrent Flow. 

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