[article]
Titre : |
Gas back-mixing in a two-dimensional baffled turbulent fluidized bed |
Type de document : |
texte imprimé |
Auteurs : |
Yongmin Zhang, Auteur ; Chunxi Lu, Auteur ; John R. Grace, Auteur |
Année de publication : |
2008 |
Article en page(s) : |
p. 8484–8491 |
Note générale : |
chemical engineering |
Langues : |
Anglais (eng) |
Mots-clés : |
Turbulent fluidized |
Résumé : |
The effect of louver baffles on gas back-mixing was investigated in a large-scale two-dimensional fluidized bed of fluid catalytic cracking (FCC) particles with helium as tracer gas. The axial gas dispersion coefficient of the baffle-free fluidized bed first increased with increasing superficial gas velocity and then decreased after reaching a maximum near the onset of the turbulent flow regime. “Gulf streaming” of emulsion flow in the baffle-free bed determined the lateral profiles of tracer gas concentration. Solids back-mixing flux was greatly reduced by the addition of a layer of louver baffles, while solids mixing above the baffle layer was enhanced. The modified baffled fluidized bed with multilayer louver baffles not only provided a high efficiency of gas−solids contacting but also greatly suppressed the back-mixing of both gas and solids. |
En ligne : |
http://pubs.acs.org/doi/abs/10.1021/ie800906n |
in Industrial & engineering chemistry research > Vol. 47 n°21 (Novembre 2008) . - p. 8484–8491
[article] Gas back-mixing in a two-dimensional baffled turbulent fluidized bed [texte imprimé] / Yongmin Zhang, Auteur ; Chunxi Lu, Auteur ; John R. Grace, Auteur . - 2008 . - p. 8484–8491. chemical engineering Langues : Anglais ( eng) in Industrial & engineering chemistry research > Vol. 47 n°21 (Novembre 2008) . - p. 8484–8491
Mots-clés : |
Turbulent fluidized |
Résumé : |
The effect of louver baffles on gas back-mixing was investigated in a large-scale two-dimensional fluidized bed of fluid catalytic cracking (FCC) particles with helium as tracer gas. The axial gas dispersion coefficient of the baffle-free fluidized bed first increased with increasing superficial gas velocity and then decreased after reaching a maximum near the onset of the turbulent flow regime. “Gulf streaming” of emulsion flow in the baffle-free bed determined the lateral profiles of tracer gas concentration. Solids back-mixing flux was greatly reduced by the addition of a layer of louver baffles, while solids mixing above the baffle layer was enhanced. The modified baffled fluidized bed with multilayer louver baffles not only provided a high efficiency of gas−solids contacting but also greatly suppressed the back-mixing of both gas and solids. |
En ligne : |
http://pubs.acs.org/doi/abs/10.1021/ie800906n |
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