Documents disponibles écrits par cet auteur

Helical and Lemniscate Tubular Reactors / Charles G. Slominski in Industrial & engineering chemistry research, Vol. 50 N° 15 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 8842–8850 Titre : Helical and Lemniscate Tubular Reactors Type de document : texte imprimé Auteurs : Charles G. Slominski, Auteur ; Warren D. Seider, Auteur ; Stuart W. Churchill, Auteur Année de publication : 2011 Article en page(s) : pp. 8842–8850 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Tubular  reactor Résumé : Introducing curvature in a tubular reactor generates a secondary fluid motion that decreases the variance of the residence-time-distribution of the fluid elements. The conversion is thereby increased with respect to that of a straight tube, and in the extreme approaches the maximum corresponding to perfect radial mixing, which is the same as that for the hypothetical case of plug flow. Helically coiled tubes are widely used as reactors in industry, but experimental data and theoretical solutions are limited in number and scope. The fluid motion and conversion as determined by finite-element solutions using COMSOL is delineated more clearly than in prior studies for helical tubes and is also applied for a lemniscate tube (a figure-eight shape). Coiled tubes, lemniscate tubes, and other such configurations are designed to decrease the variance of the residence-time distribution of the fluid elements at the expense of a minimal increase in the pressure drop. The decrease in the variance of the residence-time distribution results in a reduction in the reactor length for a specified chemical conversion and thus in the floor space required to achieve a particular conversion. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395830 [article] Helical and Lemniscate Tubular Reactors [texte imprimé] / Charles G. Slominski, Auteur ; Warren D. Seider, Auteur ; Stuart W. Churchill, Auteur . - 2011 . - pp. 8842–8850. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 8842–8850 Mots-clés : Tubular  reactor Résumé : Introducing curvature in a tubular reactor generates a secondary fluid motion that decreases the variance of the residence-time-distribution of the fluid elements. The conversion is thereby increased with respect to that of a straight tube, and in the extreme approaches the maximum corresponding to perfect radial mixing, which is the same as that for the hypothetical case of plug flow. Helically coiled tubes are widely used as reactors in industry, but experimental data and theoretical solutions are limited in number and scope. The fluid motion and conversion as determined by finite-element solutions using COMSOL is delineated more clearly than in prior studies for helical tubes and is also applied for a lemniscate tube (a figure-eight shape). Coiled tubes, lemniscate tubes, and other such configurations are designed to decrease the variance of the residence-time distribution of the fluid elements at the expense of a minimal increase in the pressure drop. The decrease in the variance of the residence-time distribution results in a reduction in the reactor length for a specified chemical conversion and thus in the floor space required to achieve a particular conversion. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395830

Incidents investigation and dynamic analysis of large alarm databases in chemical plants: a fluidized-catalytic-cracking unit case study / Ankur Pariyani in Industrial & engineering chemistry research, Vol. 49 N° 17 (Septembre 1, 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8062–8079 Titre : Incidents investigation and dynamic analysis of large alarm databases in chemical plants: a fluidized-catalytic-cracking unit case study Type de document : texte imprimé Auteurs : Ankur Pariyani, Auteur ; Warren D. Seider, Auteur Année de publication : 2010 Article en page(s) : pp 8062–8079 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Dynamic  analysis  Fluidized  catalytic  Cracking  unit. Résumé : A novel framework to model the chronology of incidents is presented—depicting the relationship of initiating events with the various regulating and protection systems of the process—eventually leading to consequences, varying from zero to high severities. The key premise is that the departures and subsequent returns of process and product quality variables, from and to their normal operating ranges, are recognized as near-misses, which could have propagated to incidents. This leads to the availability of vast near-miss information recorded in distributed control and emergency shutdown systems databases that monitor the dynamics of the process. New performance indices, which utilize this abundant information, are introduced to conduct quantitative and qualitative (absolute and relative) assessment of the real-time safety and operability performances of an industrial fluidized-catalytic-cracking unit (FCCU) at a petroleum refinery. Also, new techniques for abnormal event tracking and recovery-time analysis are presented, which help to identify the variables that experience operational difficulties. It is shown how this information can be used to suggest improvements in the alarm-system structures for the FCCU. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019648 [article] Incidents investigation and dynamic analysis of large alarm databases in chemical plants: a fluidized-catalytic-cracking unit case study [texte imprimé] / Ankur Pariyani, Auteur ; Warren D. Seider, Auteur . - 2010 . - pp 8062–8079. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8062–8079 Mots-clés : Dynamic  analysis  Fluidized  catalytic  Cracking  unit. Résumé : A novel framework to model the chronology of incidents is presented—depicting the relationship of initiating events with the various regulating and protection systems of the process—eventually leading to consequences, varying from zero to high severities. The key premise is that the departures and subsequent returns of process and product quality variables, from and to their normal operating ranges, are recognized as near-misses, which could have propagated to incidents. This leads to the availability of vast near-miss information recorded in distributed control and emergency shutdown systems databases that monitor the dynamics of the process. New performance indices, which utilize this abundant information, are introduced to conduct quantitative and qualitative (absolute and relative) assessment of the real-time safety and operability performances of an industrial fluidized-catalytic-cracking unit (FCCU) at a petroleum refinery. Also, new techniques for abnormal event tracking and recovery-time analysis are presented, which help to identify the variables that experience operational difficulties. It is shown how this information can be used to suggest improvements in the alarm-system structures for the FCCU. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019648