POROUS GAS DISTRIBUTORS IN BUBBLE-COLUMNS - EFFECT OF LIQUID PRESENCE ON DISTRIBUTOR PRESSURE-DROP - EFFECT OF START-UP PROCEDURE ON DISTRIBUTOR PERFORMANCE

Many bubble columns use porous gas distributors to obtain small bubbles and large mass transfer rates. The distributor pressure drop contributes greatly to the energy consumption of bubble columns. This study found that the presence of liquid increased this pressure drop by 200 to 900% at practical gas flowrates. A model was developed to predict this increase. It assumes that gas flows through a fraction only of the pores so as to minimize the distributor pressure drop. The mass transfer performance of a porous distributor is affected by its startup procedure. The best performance was obtained by starting the gas flow before liquid was introduced into the column. A model was developed to explain these results. Copyright © 1990 Canadian Society for Chemical Engineering