No abstract

Flow patterns, pressure loss and liquid holdup for gas-liquid concurrent downflow have been studied in glass beds and in cylindrical and spherical Co/Mo/A12O3catalyst packings with foaming and nonfoaming liquids. The different flow patterns encountered in this study are gathered in a flow pattern diagram. Correlations of pressure loss and liquid holdup are proposed in terms of the single-phase friction loss or frictional energy for the liquid and the gas when each flows alone in the bed. The types of correlation depend on the tendency of the fluid to foam or not. A comparison of the flow diagram and the pressure drop and holdup correlation of this work with those of other published studies is also presented. Introducti onRecent papers have shown the fundamental importance of the liquid holdup in the design of down flow trickle-bed reactors5'10'11'15'16'19).In such reactors, liquid holdup is intimately connected with flow patterns and pressure loss. Indeed the liquid distribution over the packing and then the gas-liquid and solid-