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Gas Fraction and Bubble Dynamics in Structured Slurry Bubble Columns / Nasim Hooshyar in Industrial & engineering chemistry research, Vol. 49 N° 21 (Novembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10689-10697 Titre : Gas Fraction and Bubble Dynamics in Structured Slurry Bubble Columns Type de document : texte imprimé Auteurs : Nasim Hooshyar, Auteur ; Peter J. Hamersma, Auteur ; Robert F. Mudde, Auteur Année de publication : 2011 Article en page(s) : pp. 10689-10697 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Particle  suspension  Bubble  column  Hydrodynamics Résumé : With the aim of structuring the flow and reducing backmixing in slurry bubble columns, we investigate the effect of needle spargers in three-phase systems. We apply optical probes in a 2D and 3D column to measure the bubble dynamics and gas fraction. Experimental results for air-water-glass beads show that an increase in solids volume fraction (1) decreases the gas fraction, (2) shifts the transition point from homogeneous to heterogeneous flow to a lower gas velocity, (3) increases the mean bubble velocity by 60-100% in the range of superficial gas velocities from 0.02 to 0.1 m/s, and (4) has only a limited effect on the bubble size distribution. Fitting our experimental data to the Richardson and Zaki and Garnier models shows that we cannot use the model coefficients they report in their papers. However, fitting our data results in realistic values for the terminal bubble velocity in a swarm. By using needle spargers, giving a very uniform gas supply, a first step toward structuring the hydrodynamics of slurry bubble columns has been taken. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447962 [article] Gas Fraction and Bubble Dynamics in Structured Slurry Bubble Columns [texte imprimé] / Nasim Hooshyar, Auteur ; Peter J. Hamersma, Auteur ; Robert F. Mudde, Auteur . - 2011 . - pp. 10689-10697. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10689-10697 Mots-clés : Particle  suspension  Bubble  column  Hydrodynamics Résumé : With the aim of structuring the flow and reducing backmixing in slurry bubble columns, we investigate the effect of needle spargers in three-phase systems. We apply optical probes in a 2D and 3D column to measure the bubble dynamics and gas fraction. Experimental results for air-water-glass beads show that an increase in solids volume fraction (1) decreases the gas fraction, (2) shifts the transition point from homogeneous to heterogeneous flow to a lower gas velocity, (3) increases the mean bubble velocity by 60-100% in the range of superficial gas velocities from 0.02 to 0.1 m/s, and (4) has only a limited effect on the bubble size distribution. Fitting our experimental data to the Richardson and Zaki and Garnier models shows that we cannot use the model coefficients they report in their papers. However, fitting our data results in realistic values for the terminal bubble velocity in a swarm. By using needle spargers, giving a very uniform gas supply, a first step toward structuring the hydrodynamics of slurry bubble columns has been taken. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447962