Documents disponibles écrits par cet auteur

Mixing and dissolution processes of pharmaceutical bulk materials in stirred tanks / Thomas Hormann in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12011-12025 Titre : Mixing and dissolution processes of pharmaceutical bulk materials in stirred tanks : experimental and numerical investigations Type de document : texte imprimé Auteurs : Thomas Hormann, Auteur ; Daniele Suzzi, Auteur ; Johannes G. Khinast, Auteur Année de publication : 2011 Article en page(s) : pp. 12011-12025 Note générale : Chimie induistrielle Langues : Anglais (eng) Mots-clés : Stirred  vessel  Bulk  material  Dissolution  Mixing Résumé : Numerical analysis of mixing and dissolution processes is becoming increasingly important for graining a process understanding and thus optimizing the production. Due to the increasing costs and shortage of raw materials, "in-silico" techniques are currently employed together with standard experimental analyses. Numerical simulations have proven to be a useful tool for understanding and optimizing industrial mixing problems. However, such simulations are still in the research phase. Although Computational Fluid Dynamics (CFD) is a well-developed and validated method, for more complex applications (e.g., industrial mixing) much work is still required to obtain reliable results quickly enough. In this work we focused on the simulation of mixing and dissolution of a bulk powder in a moderately viscous solution in an unbaffled stirred tank reactor typically used in the chemical and pharmaceutical industries. Estimations were made with regard to optimizing batch sizes, tank geometry, impeller type, and placement and process variables, such as the impeller agitation speed. In addition, the vortex formation of the liquid surface, the feeding position of the bulk powder, and the dissolution process of the solid particles that represent the bulk powder were manipulated. Finally, a quantitative comparison of different stirring systems and scale-up studies was prepared. The time-dependent and turbulent flow of the mixture was studied by solving the Reynolds-averaged Navier-Stokes equations. The numerical predictions of the flow field were validated by means of high-speed camera images and particle image velodmetry postprocessing techniques. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697521 [article] Mixing and dissolution processes of pharmaceutical bulk materials in stirred tanks : experimental and numerical investigations [texte imprimé] / Thomas Hormann, Auteur ; Daniele Suzzi, Auteur ; Johannes G. Khinast, Auteur . - 2011 . - pp. 12011-12025. Chimie induistrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12011-12025 Mots-clés : Stirred  vessel  Bulk  material  Dissolution  Mixing Résumé : Numerical analysis of mixing and dissolution processes is becoming increasingly important for graining a process understanding and thus optimizing the production. Due to the increasing costs and shortage of raw materials, "in-silico" techniques are currently employed together with standard experimental analyses. Numerical simulations have proven to be a useful tool for understanding and optimizing industrial mixing problems. However, such simulations are still in the research phase. Although Computational Fluid Dynamics (CFD) is a well-developed and validated method, for more complex applications (e.g., industrial mixing) much work is still required to obtain reliable results quickly enough. In this work we focused on the simulation of mixing and dissolution of a bulk powder in a moderately viscous solution in an unbaffled stirred tank reactor typically used in the chemical and pharmaceutical industries. Estimations were made with regard to optimizing batch sizes, tank geometry, impeller type, and placement and process variables, such as the impeller agitation speed. In addition, the vortex formation of the liquid surface, the feeding position of the bulk powder, and the dissolution process of the solid particles that represent the bulk powder were manipulated. Finally, a quantitative comparison of different stirring systems and scale-up studies was prepared. The time-dependent and turbulent flow of the mixture was studied by solving the Reynolds-averaged Navier-Stokes equations. The numerical predictions of the flow field were validated by means of high-speed camera images and particle image velodmetry postprocessing techniques. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697521