CFD modeling and simulation of clogging in packed beds with nonaqueous media

Onset of pulsing in gas–liquid trickle bed filtration

“…Over the past years, numerous investigators have attempted to describe the transient behavior of deep-bed ÿl-tration in single-phase ow through porous media (Herzig et al, 1970;O'Melia and Ali, 1978;Vigneswaran and Tulachan, 1988;Tien, 1989, Narayan et al, 1997Stephan and Chase, 2000;Ortiz-Arroyo et al, 2002). In contrast, the literature still remains short about the hydrodynamics involved in the plugging with ÿnes of gas-liquid packed bed reactors despite the critical operational problem of ÿnes in the bitumen reÿning industry.…”

“…To adapt to the deep-bed ÿltration context, these drag equations are recast as functions of the local instantaneous values of the bed porosity and of the e ective speciÿc surface area of the solid (collector + ÿnes assemblage) a cf . This latter is used instead of the collector diameter because the e ective speciÿc surface area increases with time as ÿnes are captured onto the surface of the collectors (Stephan and Chase, 2000;Ortiz-Arroyo et al, 2002). In a previous work , a constitutive relation accounting for the changes undergone by a cf due to accumulation of ÿnes was developed.…”

Fines deposition dynamics in gas–liquid trickle‐flow reactors

“…This method has been tested by Gray and coworkers, who extensively studied the effects of adding asphaltene polymers to kaolin fines on the deposition rates in hydrotreated light gas oil using a model batch internally recirculating draft-tube Ž . porous bed Wang et al, 1999Wang et al, , 2001 Although relatively little effort has been made to study the deposition phenomena of fines in nonaqueous media in trickle-bed reactors and their hydrodynamics, similar problems have been extensively studied, mainly in the context of Ž single-phase aqueous flows in deep-bed filtration Herzig et al, 1970;O'Melia and Ali, 1978;Vigneswaran and Tulachan, 1988;Tien, 1989;Stephan and Chase, 2000;Ortiz-Arroyo et . al., 2002 . While it is expected that the same general governing hydrodynamic equations model the plugging in trickle Ž .…”

Stretching operational life of trickle‐bed filters by liquid‐induced pulse flow

“…According to the simulation results, about 55% of the surface area is available for momentum transfer and thus for particle capture. This value, which is in close agreement with previously recommended values proposed by Stephan and Chase 21 and OrtizArroyo et al, 22 states that particle collisions mostly exploit the upper frontal hemisphere of the collectors and the fines alike.…”

“…Numerous investigators in the past have attempted to describe the transient behavior of deep-bed filtration, at the macroscopic and microscopic level, in the case of single-phase flow through porous media. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] The macroscopic studies are aimed at the phenomenological description of deep-bed filtration process, the prediction of its dynamic behavior, and the development of methodology and techniques for design, calculation, and optimization. Microscopic theories in deep-bed filtration are intended to provide information and insight about the mechanisms of particle deposition, the conditions under which deposition may be facilitated, and the effect of deposition on the structure of packed bed media.…”