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Investigation into bubble size distribution and transient evolution in the sparger region of gas-liquid external loop airlift reactors / Changqing Cao in Industrial & engineering chemistry research, Vol. 48 N° 12 (Juin 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 12 (Juin 2009) . - pp. 5824–5832 Titre : Investigation into bubble size distribution and transient evolution in the sparger region of gas-liquid external loop airlift reactors Type de document : texte imprimé Auteurs : Changqing Cao, Auteur ; Liangliang Zhao, Auteur ; Dongyan Xu, Auteur Année de publication : 2009 Article en page(s) : pp. 5824–5832 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Gas  sparger  Bubble  size  distribution  Gas-liquid  external  loop  airlift  reactors Résumé : It is well-known that the gas sparger can play an important role on the transient evolution of bubbles and bubble size distribution (BSD) in gas−liquid external loop airlift reactors (EL-ALRs). Therefore, the main subject of the present work was to study the influence of sparger design and process parameters on the transient evolution of bubbles and bubble size distribution (BSD) in the sparger region of the considered EL-ALRs. For this purpose, both detailed measurements and prediction of the size of bubbles produced at the sparger were carried out in EL-ALRs with different size and sparger structure parameters. The unique set of BSD curves were obtained by analyzing a large amount of bubbles with a measurement based on an image analysis technique. Additionally, Colella’s model of BSD evolution in bubble columns was further developed by implementing a detailed physical model for predicting the initial BSD at the sparger applied to gas−liquid EL-ALRs where the model input is only based on design/process parameters. A validation of the model was carried out using data from gas−liquid EL-ALRs with different size and sparger design parameters. In order to provide more deep insight for transient evolution of bubbles at the local scale in the sparger region, the computational fluid dynamics (CFD) code Fluent 6.2 was used. The transient evolution of bubbles was simulated in the sparger region of gas−liquid EL-ALR. The simulating results of bubble size are in good agreement at the lower gas velocity with the experimental data in the sparger regions of TU-A and TU-B. With increasing gas flow rate, the difference between simulations and experimental values for bubble size increases. The simulations underestimate bubble size at high gas flow rate. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801700s [article] Investigation into bubble size distribution and transient evolution in the sparger region of gas-liquid external loop airlift reactors [texte imprimé] / Changqing Cao, Auteur ; Liangliang Zhao, Auteur ; Dongyan Xu, Auteur . - 2009 . - pp. 5824–5832. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 12 (Juin 2009) . - pp. 5824–5832 Mots-clés : Gas  sparger  Bubble  size  distribution  Gas-liquid  external  loop  airlift  reactors Résumé : It is well-known that the gas sparger can play an important role on the transient evolution of bubbles and bubble size distribution (BSD) in gas−liquid external loop airlift reactors (EL-ALRs). Therefore, the main subject of the present work was to study the influence of sparger design and process parameters on the transient evolution of bubbles and bubble size distribution (BSD) in the sparger region of the considered EL-ALRs. For this purpose, both detailed measurements and prediction of the size of bubbles produced at the sparger were carried out in EL-ALRs with different size and sparger structure parameters. The unique set of BSD curves were obtained by analyzing a large amount of bubbles with a measurement based on an image analysis technique. Additionally, Colella’s model of BSD evolution in bubble columns was further developed by implementing a detailed physical model for predicting the initial BSD at the sparger applied to gas−liquid EL-ALRs where the model input is only based on design/process parameters. A validation of the model was carried out using data from gas−liquid EL-ALRs with different size and sparger design parameters. In order to provide more deep insight for transient evolution of bubbles at the local scale in the sparger region, the computational fluid dynamics (CFD) code Fluent 6.2 was used. The transient evolution of bubbles was simulated in the sparger region of gas−liquid EL-ALR. The simulating results of bubble size are in good agreement at the lower gas velocity with the experimental data in the sparger regions of TU-A and TU-B. With increasing gas flow rate, the difference between simulations and experimental values for bubble size increases. The simulations underestimate bubble size at high gas flow rate. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801700s