GAS-LIQUID FLOW MECHANISMS IN TRICKLE BEDS OPERATING IN DISPERSED BUBBLE AND PULSE FLOW

Flow mechanisms in trickle beds operating in dispersed bubble and puls e flow are discussed in detail including theoretical considerations an d literature results. The possible local flow patterns are then compar ed to experimental investigations made in a laboratory scale trickle b ed by means of the electrochemical shear rate sensor technique. In the gas-rich slugs of pulse flow the flow mechanism is analogous to trick le flow. In the liquid-rich slugs of pulse flow and in dispersed bubbl e flow, our results as well as literature data can be explained by a f low mechanism in which the liquid flow is dominated by viscous forces and the gas bubbles pass through the constrictions of the porous media by pressure pulses.