| Titre : | Gas back-mixing in a two-dimensional baffled turbulent fluidized bed (2008) |
| Auteurs : | Yongmin Zhang, Auteur ; Chunxi Lu, Auteur ; John R. Grace, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Industrial & engineering chemistry research (Vol. 47 n°21, Novembre 2008) |
| Article en page(s) : | p. 8484–8491 |
| Note générale : | chemical engineering |
| Langues : | Anglais |
| Tags : | 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 |
