Documents disponibles écrits par cet auteur

Measurement of liquid distributions in particle packings using wire - mesh sensor versus transmission tomographic imaging / Andre Bieberle in Industrial & engineering chemistry research, Vol. 49 N° 19 (Octobre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9445–9453 Titre : Measurement of liquid distributions in particle packings using wire - mesh sensor versus transmission tomographic imaging Type de document : texte imprimé Auteurs : Andre Bieberle, Auteur ; Markus Schubert, Auteur ; Marco Jose da Silva, Auteur Année de publication : 2010 Article en page(s) : pp. 9445–9453 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Imaging  techniques  Hydrodynamics Résumé : The paper compares two different imaging techniques for the investigation of the hydrodynamics in a laboratory packed bed reactor operating at different stationary states and with two different particle packings. The wire-mesh sensor offers cross-sectional liquid holdup distribution imaging at an ultra high speed of 10000 frames/s and good spatial resolution of 6 mm. It is therefore a very useful imaging tool for transient and periodic flow conditions. Up to now its influence on the flow in a packed bed was never analyzed. γ-ray computed tomography uses 662 keV γ photons to obtain cross-sectional phase distribution images. It offers as well a good spatial resolution of 2 mm and does not influence the flow but needs rather long scanning times. As a noninvasive technique γ-ray tomography has been used as a reference modality to evaluate the wire-mesh sensor measurements. Data from both imaging modalities are compared utilizing different analyzing models and showed good agreement. For the wire-mesh sensor only marginal intrusive effects for the specific situation were found. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100900g [article] Measurement of liquid distributions in particle packings using wire - mesh sensor versus transmission tomographic imaging [texte imprimé] / Andre Bieberle, Auteur ; Markus Schubert, Auteur ; Marco Jose da Silva, Auteur . - 2010 . - pp. 9445–9453. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9445–9453 Mots-clés : Imaging  techniques  Hydrodynamics Résumé : The paper compares two different imaging techniques for the investigation of the hydrodynamics in a laboratory packed bed reactor operating at different stationary states and with two different particle packings. The wire-mesh sensor offers cross-sectional liquid holdup distribution imaging at an ultra high speed of 10000 frames/s and good spatial resolution of 6 mm. It is therefore a very useful imaging tool for transient and periodic flow conditions. Up to now its influence on the flow in a packed bed was never analyzed. γ-ray computed tomography uses 662 keV γ photons to obtain cross-sectional phase distribution images. It offers as well a good spatial resolution of 2 mm and does not influence the flow but needs rather long scanning times. As a noninvasive technique γ-ray tomography has been used as a reference modality to evaluate the wire-mesh sensor measurements. Data from both imaging modalities are compared utilizing different analyzing models and showed good agreement. For the wire-mesh sensor only marginal intrusive effects for the specific situation were found. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100900g

Phase holdups in three-phase semifluidized beds and the generalized bubble wake model / Markus Schubert in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8393–8401 Titre : Phase holdups in three-phase semifluidized beds and the generalized bubble wake model Type de document : texte imprimé Auteurs : Markus Schubert, Auteur ; Faïçal Larachi, Auteur Année de publication : 2010 Article en page(s) : pp. 8393–8401 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Gas−liquid−solid  semifluidized  beds  Pressure  drop  measurements  Phase  holdup  Rector Résumé : A new experimental measurement methodology was proposed to characterize the hydrodynamics in gas−liquid−solid semifluidized beds. Using pressure drop measurements in the lower fluidized bed section and a tracer response technique in the upper fixed bed portion, the six phase holdup components of the reactor were determined simultaneously. Available models for macroscopic predictions of holdups, initially proposed for three-phase fluidization, were extended, and their applicability was discussed concerning semifluidized beds. Special attention was paid to the parameters of the generalized bubble wake model and their predictability with an artificial neural network. Phenomenological observations identified an additional interface region between both beds, which, viewed as an inchoate freeboard region determines the mechanisms of attachment and release of particles from the fluidized bed to the fixed bed portion. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900426f [article] Phase holdups in three-phase semifluidized beds and the generalized bubble wake model [texte imprimé] / Markus Schubert, Auteur ; Faïçal Larachi, Auteur . - 2010 . - pp. 8393–8401. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8393–8401 Mots-clés : Gas−liquid−solid  semifluidized  beds  Pressure  drop  measurements  Phase  holdup  Rector Résumé : A new experimental measurement methodology was proposed to characterize the hydrodynamics in gas−liquid−solid semifluidized beds. Using pressure drop measurements in the lower fluidized bed section and a tracer response technique in the upper fixed bed portion, the six phase holdup components of the reactor were determined simultaneously. Available models for macroscopic predictions of holdups, initially proposed for three-phase fluidization, were extended, and their applicability was discussed concerning semifluidized beds. Special attention was paid to the parameters of the generalized bubble wake model and their predictability with an artificial neural network. Phenomenological observations identified an additional interface region between both beds, which, viewed as an inchoate freeboard region determines the mechanisms of attachment and release of particles from the fluidized bed to the fixed bed portion. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900426f

Water and n-heptane volume fractions in a rotor-stator spinning disc reactor / Frans Visscher in Industrial & engineering chemistry research, Vol. 51 N° 51 (Décembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 51 (Décembre 2012) . - pp. 16670–16676 Titre : Water and n-heptane volume fractions in a rotor-stator spinning disc reactor Type de document : texte imprimé Auteurs : Frans Visscher, Auteur ; Andre Bieberle, Auteur ; Markus Schubert, Auteur Année de publication : 2012 Article en page(s) : pp. 16670–16676 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Volume  fractions  n  heptane  water  Rotor  stator Résumé : This paper presents the volume fractions of n-heptane and water measured in a rotor-stator spinning disc reactor. The volume fractions were measured using γ-ray tomography and photographic image analysis. The volume fractions were determined as a function of rotational disc speed, flow ratio, position in the reactor, and rotor material. In addition, the effect of the density difference between water and n-heptane was determined by dissolving potassium iodide in the water phase. Below a rotational disc speed of 75 rpm the volume fraction measured by tomography and photographic image analysis are within 10% deviation. For low rotational disc speeds, the n-heptane volume fraction decreases slightly with increasing rotational disc speed: the centrifugal force accelerates the larger n-heptane droplets to the center. At higher rotational disc speeds the droplets become smaller accordingly, the friction between the phases determines the flow, and the n-heptane volume fraction becomes equal to the n-heptane to total flow ratio. An increase in density difference from 0.31 to 0.79 kg dm–3 did not influence the volume fractions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301439s [article] Water and n-heptane volume fractions in a rotor-stator spinning disc reactor [texte imprimé] / Frans Visscher, Auteur ; Andre Bieberle, Auteur ; Markus Schubert, Auteur . - 2012 . - pp. 16670–16676. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 51 (Décembre 2012) . - pp. 16670–16676 Mots-clés : Volume  fractions  n  heptane  water  Rotor  stator Résumé : This paper presents the volume fractions of n-heptane and water measured in a rotor-stator spinning disc reactor. The volume fractions were measured using γ-ray tomography and photographic image analysis. The volume fractions were determined as a function of rotational disc speed, flow ratio, position in the reactor, and rotor material. In addition, the effect of the density difference between water and n-heptane was determined by dissolving potassium iodide in the water phase. Below a rotational disc speed of 75 rpm the volume fraction measured by tomography and photographic image analysis are within 10% deviation. For low rotational disc speeds, the n-heptane volume fraction decreases slightly with increasing rotational disc speed: the centrifugal force accelerates the larger n-heptane droplets to the center. At higher rotational disc speeds the droplets become smaller accordingly, the friction between the phases determines the flow, and the n-heptane volume fraction becomes equal to the n-heptane to total flow ratio. An increase in density difference from 0.31 to 0.79 kg dm–3 did not influence the volume fractions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301439s