Documents disponibles écrits par cet auteur

CFD modeling of metronidazole degradation in water by the UV / H2O2 process in single and multilamp photoreactors / Mehrab Mehrvar in Industrial & engineering chemistry research, Vol. 49 N° 11 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5367–5382 Titre : CFD modeling of metronidazole degradation in water by the UV / H2O2 process in single and multilamp photoreactors Type de document : texte imprimé Auteurs : Mehrab Mehrvar, Auteur ; Farhad Ein-Mozaffari, Auteur Année de publication : 2010 Article en page(s) : pp. 5367–5382 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Metronidazole  Photoreactors Résumé : A dynamic model for the degradation of aqueous metronidazole by hydrogen peroxide and ultraviolet irradiation processes (UV/H2O2) as an advanced oxidation technology (AOT) in a single lamp tubular photoreactor as well as in a multilamp tubular photoreactor is developed. The model contains the main chemical and photochemical reactions in a medium flowing in the turbulent regime. The optimal hydrogen peroxide concentrations of 75, 150, and 200 mg L−1 were predicted for different alkalinity concentrations of 0, 1.5, and 3 μM, respectively. The model is validated with distilled water as well as alkaline water at different alkalinity concentrations. The model is validated by using the experimental data reported in the open literature. The velocity field and concentration profiles for the turbulent flow using the k−ε model are determined by computational fluid dynamics (CFD). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900906e [article] CFD modeling of metronidazole degradation in water by the UV / H2O2 process in single and multilamp photoreactors [texte imprimé] / Mehrab Mehrvar, Auteur ; Farhad Ein-Mozaffari, Auteur . - 2010 . - pp. 5367–5382. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5367–5382 Mots-clés : Metronidazole  Photoreactors Résumé : A dynamic model for the degradation of aqueous metronidazole by hydrogen peroxide and ultraviolet irradiation processes (UV/H2O2) as an advanced oxidation technology (AOT) in a single lamp tubular photoreactor as well as in a multilamp tubular photoreactor is developed. The model contains the main chemical and photochemical reactions in a medium flowing in the turbulent regime. The optimal hydrogen peroxide concentrations of 75, 150, and 200 mg L−1 were predicted for different alkalinity concentrations of 0, 1.5, and 3 μM, respectively. The model is validated with distilled water as well as alkaline water at different alkalinity concentrations. The model is validated by using the experimental data reported in the open literature. The velocity field and concentration profiles for the turbulent flow using the k−ε model are determined by computational fluid dynamics (CFD). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900906e

Dynamic performance of continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors / Dineshkumar Patel 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. 9377–9389 Titre : Dynamic performance of continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors Type de document : texte imprimé Auteurs : Dineshkumar Patel, Auteur ; Farhad Ein-Mozaffari, Auteur ; Mehrab Mehrvar, Auteur Année de publication : 2011 Article en page(s) : pp. 9377–9389 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pseudoplastic  fluids Résumé : The core objectives of this work were to characterize and optimize the continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors. To achieve these objectives, the effects of impeller type (for the seven axial-flow impellers A100, A200, A310, A315, A320, 3AH, and 3AM and the four radial-flow impellers R500, RSB, RT, and Scaba), impeller speed (50–800 rpm), impeller diameter (T/3.2–T/1.6, where T is the tank diameter), impeller off-bottom clearance (H/3.4–H/1.7, where H is the fluid height in the vessel), inlet and outlet locations (for the four configurations top inlet–top outlet, top inlet–bottom outlet, bottom inlet–bottom outlet, and bottom inlet–top outlet), pumping directions for axial-flow impellers (upward and downward pumping), fluid height in the vessel (T/1.06–T/0.83), residence time (257–328 s), and jet velocity (0.317–3.24 m s–1) on the dynamic performance of the mixing vessel were explored. To identify nonideal flows, dynamic tests were conducted using the frequency-modulated random binary input of a brine solution with the feed. The mixing quality in the vessel was substantially improved by increasing the impeller diameter, increasing the residence time, optimizing the impeller off-bottom clearance, decreasing the fluid height, optimizing the jet velocity, and using the up-pumping axial-flow impeller. Applying these findings will lead to improved quality of products and more efficient use of power in continuous-flow mixing of yield-pseudoplastic fluids. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102388y [article] Dynamic performance of continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors [texte imprimé] / Dineshkumar Patel, Auteur ; Farhad Ein-Mozaffari, Auteur ; Mehrab Mehrvar, Auteur . - 2011 . - pp. 9377–9389. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9377–9389 Mots-clés : Pseudoplastic  fluids Résumé : The core objectives of this work were to characterize and optimize the continuous-flow mixing of pseudoplastic fluids exhibiting yield stress in stirred reactors. To achieve these objectives, the effects of impeller type (for the seven axial-flow impellers A100, A200, A310, A315, A320, 3AH, and 3AM and the four radial-flow impellers R500, RSB, RT, and Scaba), impeller speed (50–800 rpm), impeller diameter (T/3.2–T/1.6, where T is the tank diameter), impeller off-bottom clearance (H/3.4–H/1.7, where H is the fluid height in the vessel), inlet and outlet locations (for the four configurations top inlet–top outlet, top inlet–bottom outlet, bottom inlet–bottom outlet, and bottom inlet–top outlet), pumping directions for axial-flow impellers (upward and downward pumping), fluid height in the vessel (T/1.06–T/0.83), residence time (257–328 s), and jet velocity (0.317–3.24 m s–1) on the dynamic performance of the mixing vessel were explored. To identify nonideal flows, dynamic tests were conducted using the frequency-modulated random binary input of a brine solution with the feed. The mixing quality in the vessel was substantially improved by increasing the impeller diameter, increasing the residence time, optimizing the impeller off-bottom clearance, decreasing the fluid height, optimizing the jet velocity, and using the up-pumping axial-flow impeller. Applying these findings will lead to improved quality of products and more efficient use of power in continuous-flow mixing of yield-pseudoplastic fluids. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102388y

Study of solid − liquid mixing in agitated tanks through computational fluid dynamics modeling / Seyed Hosseini in Industrial & engineering chemistry research, Vol. 49 N° 9 (Mai 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4426–4435 Titre : Study of solid − liquid mixing in agitated tanks through computational fluid dynamics modeling Type de document : texte imprimé Auteurs : Seyed Hosseini, Auteur ; Dineshkumar Patel, Auteur ; Farhad Ein-Mozaffari, Auteur Année de publication : 2010 Article en page(s) : pp. 4426–4435 Note générale : Industrial chemisty Langues : Anglais (eng) Mots-clés : Fluid  Dynamics Résumé : Solid−liquid mixing is one of the most important mixing operations due to its vast applications in many unit operations such as crystallization, adsorption, solid-catalyzed reaction, suspension polymerization, and activated sludge processes. In this study, a computational fluid dynamics (CFD) model was developed for solid−liquid mixing in a cylindrical tank equipped with a top-entering impeller to investigate the effect of impeller type (Lightnin A100, A200, and A310), impeller off-bottom clearance (T/6−T/2, where T is tank diameter), impeller speed (150−800 rpm), particle size (100−900 μm), and particle specific gravity (1.4−6) on the mixing quality. An Eulerian−Eulerian (EE) approach, standard k−ε model, and multiple reference frames (MRF) techniques were employed to simulate the two-phase flow, turbulent flow, and impeller rotation, respectively. The impeller torque, cloud height, and just suspended impeller speed (Njs) computed by the CFD model agreed well with the experimental data. The validated CFD model was then employed to calculate the solid concentration profiles by which the degree of homogeneity was quantified as a function of operating conditions and design parameters. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901130z [article] Study of solid − liquid mixing in agitated tanks through computational fluid dynamics modeling [texte imprimé] / Seyed Hosseini, Auteur ; Dineshkumar Patel, Auteur ; Farhad Ein-Mozaffari, Auteur . - 2010 . - pp. 4426–4435. Industrial chemisty Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4426–4435 Mots-clés : Fluid  Dynamics Résumé : Solid−liquid mixing is one of the most important mixing operations due to its vast applications in many unit operations such as crystallization, adsorption, solid-catalyzed reaction, suspension polymerization, and activated sludge processes. In this study, a computational fluid dynamics (CFD) model was developed for solid−liquid mixing in a cylindrical tank equipped with a top-entering impeller to investigate the effect of impeller type (Lightnin A100, A200, and A310), impeller off-bottom clearance (T/6−T/2, where T is tank diameter), impeller speed (150−800 rpm), particle size (100−900 μm), and particle specific gravity (1.4−6) on the mixing quality. An Eulerian−Eulerian (EE) approach, standard k−ε model, and multiple reference frames (MRF) techniques were employed to simulate the two-phase flow, turbulent flow, and impeller rotation, respectively. The impeller torque, cloud height, and just suspended impeller speed (Njs) computed by the CFD model agreed well with the experimental data. The validated CFD model was then employed to calculate the solid concentration profiles by which the degree of homogeneity was quantified as a function of operating conditions and design parameters. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901130z

Using computational fluid dynamics to study the dynamic behavior of the continuous mixing of Herschel-Bulkley fluids / Salwan Saeed in Industrial & engineering chemistry research, Vol. 47 N°19 (Octobre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°19 (Octobre 2008) . - p. 7465–7475 Titre : Using computational fluid dynamics to study the dynamic behavior of the continuous mixing of Herschel-Bulkley fluids Type de document : texte imprimé Auteurs : Salwan Saeed, Auteur ; Farhad Ein-Mozaffari, Auteur ; Simant R. Upreti, Auteur Année de publication : 2008 Article en page(s) : p. 7465–7475 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Continuous-flow  mixer  Xanthan  gum  solution  Dynamic  model  Computational  fluid  dynamics Résumé : A continuous-flow mixer was designed and built to study the mixing of xanthan gum solution, a pseudoplastic fluid possessing yield stress. The extent of flow nonideality was quantified using a dynamic model that incorporated two parameters: channeling and fully mixed volume in the vessel. Dynamic experiments were made using the frequency-modulated random binary input of a brine solution to determine the magnitude of nonideal flow parameters. The same experiments were simulated using a computational fluid dynamics (CFD) package (Fluent 6.2). CFD flow fields were used to obtain the system dynamic response to a tracer injection applied at conditions identical to the experimental ones. The extents of channeling and effective mixed volume were determined using the CFD model and then compared with the parameters obtained experimentally. Validated CFD flow fields enabled us to effectively monitor the effect of various operating conditions on flow nonideality, to relate flow pattern and cavern dimension to flow nonideality, to compare the efficiency of impellers, and to provide a pictorial synopsis of continuous-flow mixing operation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800496x [article] Using computational fluid dynamics to study the dynamic behavior of the continuous mixing of Herschel-Bulkley fluids [texte imprimé] / Salwan Saeed, Auteur ; Farhad Ein-Mozaffari, Auteur ; Simant R. Upreti, Auteur . - 2008 . - p. 7465–7475. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°19 (Octobre 2008) . - p. 7465–7475 Mots-clés : Continuous-flow  mixer  Xanthan  gum  solution  Dynamic  model  Computational  fluid  dynamics Résumé : A continuous-flow mixer was designed and built to study the mixing of xanthan gum solution, a pseudoplastic fluid possessing yield stress. The extent of flow nonideality was quantified using a dynamic model that incorporated two parameters: channeling and fully mixed volume in the vessel. Dynamic experiments were made using the frequency-modulated random binary input of a brine solution to determine the magnitude of nonideal flow parameters. The same experiments were simulated using a computational fluid dynamics (CFD) package (Fluent 6.2). CFD flow fields were used to obtain the system dynamic response to a tracer injection applied at conditions identical to the experimental ones. The extents of channeling and effective mixed volume were determined using the CFD model and then compared with the parameters obtained experimentally. Validated CFD flow fields enabled us to effectively monitor the effect of various operating conditions on flow nonideality, to relate flow pattern and cavern dimension to flow nonideality, to compare the efficiency of impellers, and to provide a pictorial synopsis of continuous-flow mixing operation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800496x