Documents disponibles écrits par cet auteur

Gas holdup, axial dispersion, and mass transfer studies in bubble columns / Mayank Shah in Industrial & engineering chemistry research, Vol. 51 N° 43 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14268–14278 Titre : Gas holdup, axial dispersion, and mass transfer studies in bubble columns Type de document : texte imprimé Auteurs : Mayank Shah, Auteur ; Anton A. Kiss, Auteur ; Edwin Zondervan, Auteur Année de publication : 2013 Article en page(s) : pp. 14268–14278 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas  Mass  Transfer Résumé : This article presents an extensive study on the gas holdup, axial liquid dispersion, and mass transfer for packed, trayed, and empty bubble columns. Four types of structured packings (Super-Pak, Flexipac, Mellapak, and Gauze) and two types of perforated partition trays (with 25% and 40% tray open area) were used to characterize the packed and trayed bubble columns, respectively. It was observed that the gas holdup and mass transfer characteristics of the packed and trayed bubble columns are superior to those of an empty bubble column, while the axial dispersion coefficients are much lower. This article discusses in detail the effect of the liquid and gas flow rates, liquid-phase viscosity, and type of internals. Additionally, experimental data of the packed, trayed, and empty bubble column are correlated by dimensionless numbers. Novel empirical correlations are proposed for the gas holdup, Bodenstein number (for the axial dispersion coefficient), and Stanton number (for the volumetric mass transfer coefficient), as a function of the Froude and Galileo dimensionless numbers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301227t [article] Gas holdup, axial dispersion, and mass transfer studies in bubble columns [texte imprimé] / Mayank Shah, Auteur ; Anton A. Kiss, Auteur ; Edwin Zondervan, Auteur . - 2013 . - pp. 14268–14278. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14268–14278 Mots-clés : Gas  Mass  Transfer Résumé : This article presents an extensive study on the gas holdup, axial liquid dispersion, and mass transfer for packed, trayed, and empty bubble columns. Four types of structured packings (Super-Pak, Flexipac, Mellapak, and Gauze) and two types of perforated partition trays (with 25% and 40% tray open area) were used to characterize the packed and trayed bubble columns, respectively. It was observed that the gas holdup and mass transfer characteristics of the packed and trayed bubble columns are superior to those of an empty bubble column, while the axial dispersion coefficients are much lower. This article discusses in detail the effect of the liquid and gas flow rates, liquid-phase viscosity, and type of internals. Additionally, experimental data of the packed, trayed, and empty bubble column are correlated by dimensionless numbers. Novel empirical correlations are proposed for the gas holdup, Bodenstein number (for the axial dispersion coefficient), and Stanton number (for the volumetric mass transfer coefficient), as a function of the Froude and Galileo dimensionless numbers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301227t

Scheduling in the FMCG industry / Martijn A. H. van Elzakker in Industrial & engineering chemistry research, Vol. 51 N° 22 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 22 (Juin 2012) . - pp. 7800–7815 Titre : Scheduling in the FMCG industry : An industrial case study Type de document : texte imprimé Auteurs : Martijn A. H. van Elzakker, Auteur ; Edwin Zondervan, Auteur ; Neha B. Raikar, Auteur Année de publication : 2012 Article en page(s) : pp. 7800–7815 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Scheduling  Industry Résumé : A problem-specific model is presented for the short-term scheduling problem in the Fast Moving Consumer Goods (FMCG) industry. To increase the computational efficiency, the limited intermediate inventory is modeled indirectly by relating mixing and packing intervals. In addition, the model size is reduced by exploiting the process characteristics by dedicating time intervals to product types. The efficiency and flexibility of the formulation is demonstrated using ten examples based on an ice cream scheduling case study. The examples contain 62–73 batches of 8 products that must be produced within a 120-h horizon. All cases can be solved to optimality within 170 s. The addition of a periodic cleaning requirement on the mixing lines significantly increases the complexity of the problem. An algorithm is proposed that solves to optimality within half an hour 9 out of 10 cases with periodic cleaning. For the 10th case the makespan obtained was 0.6% higher than the theoretical minimum makespan. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202106k [article] Scheduling in the FMCG industry : An industrial case study [texte imprimé] / Martijn A. H. van Elzakker, Auteur ; Edwin Zondervan, Auteur ; Neha B. Raikar, Auteur . - 2012 . - pp. 7800–7815. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 22 (Juin 2012) . - pp. 7800–7815 Mots-clés : Scheduling  Industry Résumé : A problem-specific model is presented for the short-term scheduling problem in the Fast Moving Consumer Goods (FMCG) industry. To increase the computational efficiency, the limited intermediate inventory is modeled indirectly by relating mixing and packing intervals. In addition, the model size is reduced by exploiting the process characteristics by dedicating time intervals to product types. The efficiency and flexibility of the formulation is demonstrated using ten examples based on an ice cream scheduling case study. The examples contain 62–73 batches of 8 products that must be produced within a 120-h horizon. All cases can be solved to optimality within 170 s. The addition of a periodic cleaning requirement on the mixing lines significantly increases the complexity of the problem. An algorithm is proposed that solves to optimality within half an hour 9 out of 10 cases with periodic cleaning. For the 10th case the makespan obtained was 0.6% higher than the theoretical minimum makespan. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202106k