Experiments were carried out to investigate the evolving hydrodynamics of trickle-bed reactors as altered by the concomitant filtration of a flowing suspension containing micrometer-scale fines. The filtration efficiency, two-phase pressure drop, and bed specific deposit (mass of deposited fines per unit of reactor volume) were monitored using flows of air and a kaolin-containing kerosene suspension to clarify the roles of packing (smooth vs porous collectors), bed height, bed entrance distribution of the suspension, makeup addition in recirculation mode, gas superficial velocity, and flow regime transition. It was observed that deposition did not exhibit a seamless pattern but rather consisted of scattered mesoscale islands of deposits, several collector-diameters in size, separated by relatively large plug-free multiple interconnected pores. These corridors favored the in situ development of bed maldistribution that favored short-circuiting of the flow and leveling off of the bed pressure drop. Contrary to expectation, the transition from trickle flow to pulse flow due to progressive bed obstruction was not systematic, and to occur, it required a minimum clean-bed starting liquid holdup value.
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