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Mass transfer performance in karr reciprocating plate extraction columns / Angela Stella in Industrial & engineering chemistry research, Vol. 47 n°11 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3996–4007 Titre : Mass transfer performance in karr reciprocating plate extraction columns Type de document : texte imprimé Auteurs : Angela Stella, Auteur ; Kathryn H. Mensforth, Auteur ; Tim Bowser, Auteur ; Geoffrey W. Steven, Auteur Année de publication : 2008 Article en page(s) : p. 3996–4007 Note générale : Bibliogr.p . 4006-4007 Langues : Anglais (eng) Mots-clés : Karr  reciprocating  plate;  Hydrodynamic  performance;  Mass  transfer Résumé : A study of the hydrodynamic and mass transfer performance for Karr reciprocating plate extraction columns has been presented for a range of operating conditions and column diameters of 50, 100, and 450 mm. Although the use of Karr columns has been widespread for many years for a range of important applications, the need for more reliable methods for predicting the performance and scale-up of such columns continues to be a matter of significant importance. The present study has examined the hydrodynamic performance in terms of the dispersed phase hold up and droplet size distribution and mass transfer performance which has incorporated the effects of backmixing in the continuous phase. Work was initially carried out in a 50 mm diameter laboratory scale Karr column using the system 10 v/v% tributyl phosphate/kerosene (continuous)−phenol−water (dispersed) where hydrodynamic and mass transfer performance was analyzed for both directions of mass transfer. Using these data, models were investigated and developed to predict performance over a range of operating conditions. An alternative system consisting of an organic solvent (continuous)−phenolic alkaloid−aqueous caustic (dispersed) was also studied, using both 100 and 450 mm diameter Karr columns. These data were used to validate the hydrodynamic and mass transfer performance models developed for the phenol system in the 50 mm diameter column. Dispersed phase holdup data were found to fit the correlation presented by Kumar and Hartland [Ind. Eng. Chem. Res. 1995, 34, 3925−3940], and the drop size distribution also agreed with the relationship presented by Kumar and Hartland [Ind. Eng. Chem. Res. 1996, 35, 2682−2695] within reasonable accuracy. The mass transfer performance results indicated that the continuous phase controlled the mass transfer rate, and thus, column design was simplified by assuming that the overall mass transfer coefficient can be obtained using a standard mass transfer correlation for the continuous phase. The current mass transfer results were found to be best predicted by a refitted form of the overall mass transfer coefficient correlation developed by Harikrishnan et al. [Chem. Eng. J. 1994, 54, 7−16]. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071623p [article] Mass transfer performance in karr reciprocating plate extraction columns [texte imprimé] / Angela Stella, Auteur ; Kathryn H. Mensforth, Auteur ; Tim Bowser, Auteur ; Geoffrey W. Steven, Auteur . - 2008 . - p. 3996–4007. Bibliogr.p . 4006-4007 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3996–4007 Mots-clés : Karr  reciprocating  plate;  Hydrodynamic  performance;  Mass  transfer Résumé : A study of the hydrodynamic and mass transfer performance for Karr reciprocating plate extraction columns has been presented for a range of operating conditions and column diameters of 50, 100, and 450 mm. Although the use of Karr columns has been widespread for many years for a range of important applications, the need for more reliable methods for predicting the performance and scale-up of such columns continues to be a matter of significant importance. The present study has examined the hydrodynamic performance in terms of the dispersed phase hold up and droplet size distribution and mass transfer performance which has incorporated the effects of backmixing in the continuous phase. Work was initially carried out in a 50 mm diameter laboratory scale Karr column using the system 10 v/v% tributyl phosphate/kerosene (continuous)−phenol−water (dispersed) where hydrodynamic and mass transfer performance was analyzed for both directions of mass transfer. Using these data, models were investigated and developed to predict performance over a range of operating conditions. An alternative system consisting of an organic solvent (continuous)−phenolic alkaloid−aqueous caustic (dispersed) was also studied, using both 100 and 450 mm diameter Karr columns. These data were used to validate the hydrodynamic and mass transfer performance models developed for the phenol system in the 50 mm diameter column. Dispersed phase holdup data were found to fit the correlation presented by Kumar and Hartland [Ind. Eng. Chem. Res. 1995, 34, 3925−3940], and the drop size distribution also agreed with the relationship presented by Kumar and Hartland [Ind. Eng. Chem. Res. 1996, 35, 2682−2695] within reasonable accuracy. The mass transfer performance results indicated that the continuous phase controlled the mass transfer rate, and thus, column design was simplified by assuming that the overall mass transfer coefficient can be obtained using a standard mass transfer correlation for the continuous phase. The current mass transfer results were found to be best predicted by a refitted form of the overall mass transfer coefficient correlation developed by Harikrishnan et al. [Chem. Eng. J. 1994, 54, 7−16]. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071623p

Performance and scale-up of karr reciprocating plate extraction columns / Kathryn H. Smith in Industrial & engineering chemistry research, Vol. 47 n°21 (Novembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°21 (Novembre 2008) . - p 8368–8375 Titre : Performance and scale-up of karr reciprocating plate extraction columns Type de document : texte imprimé Auteurs : Kathryn H. Smith, Auteur ; Tim Bowser, Auteur ; Geoff W. Stevens, Auteur Année de publication : 2008 Article en page(s) : p 8368–8375 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Hydrodynamic  and  mass  System  of  kerosene/tributyl  phosphate− Résumé : The hydrodynamic and mass transfer performance of Karr reciprocating plate extraction columns with varying column diameters has been presented in order to examine how column performance changes with scale. An ideal liquid system of kerosene/tributyl phosphate−phenol−water was initially studied using a 50 mm diameter Karr column. Correlations were developed to predict the dispersed phase holdup, drop size distribution, and overall mass transfer coefficient over a range of operating conditions. This was followed by column performance studies using a phenolic alkaloid liquid system in Karr columns with diameters of 50, 100, and 300 mm. Overall results showed that there was no significant change in either the dispersed phase holdup or the mass transfer coefficient with column diameter. It was therefore concluded that overall column performance was independent of column diameter and the traditional Karr column scale-up equations were too conservative. This study also showed that factors such as droplet and plate coalescence, contamination of liquid systems, aging of column internals, and variation in physical properties can greatly influence the column’s performance and need to be carefully considered when designing a Karr column. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800581u#afn1 [article] Performance and scale-up of karr reciprocating plate extraction columns [texte imprimé] / Kathryn H. Smith, Auteur ; Tim Bowser, Auteur ; Geoff W. Stevens, Auteur . - 2008 . - p 8368–8375. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°21 (Novembre 2008) . - p 8368–8375 Mots-clés : Hydrodynamic  and  mass  System  of  kerosene/tributyl  phosphate− Résumé : The hydrodynamic and mass transfer performance of Karr reciprocating plate extraction columns with varying column diameters has been presented in order to examine how column performance changes with scale. An ideal liquid system of kerosene/tributyl phosphate−phenol−water was initially studied using a 50 mm diameter Karr column. Correlations were developed to predict the dispersed phase holdup, drop size distribution, and overall mass transfer coefficient over a range of operating conditions. This was followed by column performance studies using a phenolic alkaloid liquid system in Karr columns with diameters of 50, 100, and 300 mm. Overall results showed that there was no significant change in either the dispersed phase holdup or the mass transfer coefficient with column diameter. It was therefore concluded that overall column performance was independent of column diameter and the traditional Karr column scale-up equations were too conservative. This study also showed that factors such as droplet and plate coalescence, contamination of liquid systems, aging of column internals, and variation in physical properties can greatly influence the column’s performance and need to be carefully considered when designing a Karr column. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800581u#afn1