Influence of Gas Flow Rate on Liquid Distribution in Trickle-Beds Using Perforated Plates as Liquid Distributors

Abstract

International audienceTwo wire mesh tomography devices and a liquid collector were used to study the influence of the gas flow rate on liquid distribution when fluids distribution on top of the reactor is ensured by a perforated plate. In opposition to most of the studies realized by other authors, conditions in which the gas has a negative impact in liquid distribution were evidenced. Indeed, the obtained results show that the influence of gas flow rate depends on the quality of the initial distribution, as the gas forces the liquid to “respect” the distribution imposed at the top of the reactor. Finally, a comparison between the two measuring techniques shows the limitations of the liquid collector and the improper conclusions to which its use could lead

Liquid spreading in trickle-bed reactors: Experiments and numerical simulations using Eulerian–Eulerian two-fluid approach

“…Moreover, these authors warned that liquid flux patterns measured from a liquid collecting technique may lead to appreciation error as regards liquid distribution because of the inability of this technique to capture maldistributions in terms of liquid saturation. Results obtained in this work as regards gas effect on liquid spreading seem consistent withLlamas and al. (2009) observations.…”

“…This is due to increase of pressure drop that leads to better radial liquid spreading when gas flow rate is increased (Moller et al, 1996;Kundu et al, 2001). Llamas et al (2009)…”

“…This is due to increase of pressure drop that leads to better radial liquid spreading when gas flow rate is increased (Moller et al, 1996;Kundu et al, 2001). Llamas et al (2009) In this section, experiments of Marcandelli et al (2000) have been considered. Contrarily to liquid feeding configuration from a central nozzle, these experiments allow test the present developed model in off-center feeding conditions resulting in 3D non-axisymmetric flow.…”

Emulation of gas‐liquid flow in packed beds for offshore floating applications using a swell simulation hexapod

“…According to this criterion, Figure a confirms the degradation of liquid distribution with column tilt; the lowest χ value being achieved in vertical position while it nearly quadrupled at a tilt of 15°. The fact that χ was not much closer to the theoretical zero value in the vertical station was attributed to the sensitivity of χ , on one hand, to sensor invasiveness which might perturb the local bed porosity due to geometric mismatch of the beads‐wire mesh neighborhood, and conversely, to small imperfections in the liquid feed on the bed top that might have led to the line‐average liquid saturation profile highlighted in Figure b 1 …”

Liquid Flow Visualization in Packed‐Bed Multiphase Reactors: Wire‐Mesh Sensor Design and Data Analysis for Rotating Fixed Beds

“…Wire-Mesh Sensors Inspired by the conductivity sensor developed by Prasser et al [7], the Chemical Engineering Group at ENSIC CNRS in Nancy (Professor Wild) applied a similar WMS technique for the first time in a trickle-bed reactor [9]. They measured liquid fractions and their distribution [10,11], local flow regime transition at individual sensing points of the sensor [9] as well as radial liquid spreading [12]. The device, however, was not applicable to porous particle packings and organics liquid, which are commonly present in trickle-bed reactors.…”