Numerical simulation study of the hydrodynamic ...
Document type :
Article dans une revue scientifique
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Title :
Numerical simulation study of the hydrodynamic regimes in large to micro fluidized beds based on a Two-Fluid Mode
Author(s) :
Zhuojun, Jiang [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Haiqin, Quan [Auteur]
Shanghai University
Fatah, Nouria [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Haiqin, Quan [Auteur]
Shanghai University
Fatah, Nouria [Auteur]

Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Journal title :
Chemical Engineering Science
Volume number :
267
Pages :
118358
Publisher :
Elsevier
Publication date :
2023-03-05
ISSN :
0009-2509
English keyword(s) :
Micro-fluidized bed
Wall effect
Two-fluid model
Hydrodynamics
Boundary
conditions
Wall effect
Two-fluid model
Hydrodynamics
Boundary
conditions
HAL domain(s) :
Chimie/Catalyse
English abstract : [en]
Although the hydrodynamic properties of fluidized bed reactors have been investigated experimentally in the macro- to micro-scale range, the measurements and diagnostic tools needed for this analysis are complex. This in ...
Show more >Although the hydrodynamic properties of fluidized bed reactors have been investigated experimentally in the macro- to micro-scale range, the measurements and diagnostic tools needed for this analysis are complex. This in turn increases the difficulties experienced when trying to account for various specific phenomena, which occur within very small, i.e. Micro-Fluidized Beds (MFBs). In the present study, a numerical approach has been used to better understand the hydrodynamic behaviour of microreactors. The influence of a reduced value of bed diameter (Dt), the value of the static bed height (Hs), and the role of changing boundary conditions on various hydrodynamic parameters, bubble behaviours and particle circulation patterns were simulated using a Two-Fluid Model (TFM), and compared with our previous experimental results. It was found that a reasonable setting of the solid volume fraction in a fixed bed (εs,0) was key to successful simulation of the onset of minimum fluidization (and minimum bubbling), which is delayed for decreasing values of Dt . Setting the specularity coefficient (Φ) to 1 resulted in bubble and particle movements being more consistent with those observed in the MFB experiment. In the simulation, a round-nosed slug rose along the center of the bed for small values of Hs , whereas it transformed into a wall slug in the upper region at greater values of Hs, which is in good agreement with our experimental observations. In addition, the experimental phenomenon in which slug is prevented from rising upwards within the MFB was successfully reproduced in the simulation.Show less >
Show more >Although the hydrodynamic properties of fluidized bed reactors have been investigated experimentally in the macro- to micro-scale range, the measurements and diagnostic tools needed for this analysis are complex. This in turn increases the difficulties experienced when trying to account for various specific phenomena, which occur within very small, i.e. Micro-Fluidized Beds (MFBs). In the present study, a numerical approach has been used to better understand the hydrodynamic behaviour of microreactors. The influence of a reduced value of bed diameter (Dt), the value of the static bed height (Hs), and the role of changing boundary conditions on various hydrodynamic parameters, bubble behaviours and particle circulation patterns were simulated using a Two-Fluid Model (TFM), and compared with our previous experimental results. It was found that a reasonable setting of the solid volume fraction in a fixed bed (εs,0) was key to successful simulation of the onset of minimum fluidization (and minimum bubbling), which is delayed for decreasing values of Dt . Setting the specularity coefficient (Φ) to 1 resulted in bubble and particle movements being more consistent with those observed in the MFB experiment. In the simulation, a round-nosed slug rose along the center of the bed for small values of Hs , whereas it transformed into a wall slug in the upper region at greater values of Hs, which is in good agreement with our experimental observations. In addition, the experimental phenomenon in which slug is prevented from rising upwards within the MFB was successfully reproduced in the simulation.Show less >
Language :
Anglais
Audience :
Internationale
Popular science :
Non
Administrative institution(s) :
Université de Lille
CNRS
Centrale Lille
ENSCL
Univ. Artois
CNRS
Centrale Lille
ENSCL
Univ. Artois
Collections :
Research team(s) :
Catalyse pour l’énergie (CATEN)
Submission date :
2023-11-15T18:06:27Z
2023-11-28T16:26:15Z
2023-11-28T16:26:15Z
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