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Titre :
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Flow profiles of power law fluids in scraped surface heat exchanger geometry using MRI
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Auteurs :
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W. Wang ;
J. Walton ;
K. Mac Carthy
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Type de document :
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article/chapitre/communication
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Année de publication :
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1999
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Format :
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p. 11-27
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Langues:
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= Anglais
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Catégories :
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INDUSTRIE AGRO-ALIMENTAIRE
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Mots-clés:
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RESONANCE MAGNETIQUE NUCLEAIRE
;
FLUIDE NON NEWTONIEN
;
VITESSE D'ECOULEMENT
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Résumé :
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Scraped surface heat exchangers (SSHE) are prevalent in the food industry to heat/cool viscous fluids and to provide enhanced mixing. This work focused on developing and verifying a theoretical model to characterize the flow patterns in two-dimensional angular flow in an SSHE geometry under isothermal conditions. Experimentally, the model was verified by a noninvasive magnetic resonance imaging (MRT) technique. Good agreement was achieved between the theoretical model and experimental data for a polyalkylene glycol, which behaved as a Newtonian fluid (n = 1), and a 1% CMC solution, a power law fluid with n = 0.77. However, the experimental flow profile tomato puree was characterized by apparent wall slip. The best fit, with respect to the power law model, was a flow behavior index of 0.11. This study provides the framework to quantify the effects of heat transfer on flow profiles in this geometry and the effectiveness of mixing.
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Source :
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Journal of Food Process Engineering, vol.22, n°1
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