Fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumption

Air flow through packed beds was analyzed experimentally under conditions ranging from those that reinforce the effect of the wall on the void fraction to those that minimize it. The packing was spherical particles, with a tube-to-particle diameter ratio (D/dp) between 3 and 60. Air flow rates were maintained between 1.3 and 4.44 m3/min, and gas velocity was measured with a Pitot tube positioned above the bed exit. Measurements were made at various radial and angular coordinate values, allowing the distribution of air flow across the bed to be described in detail. Comparison of the experimentally observed radial profiles with those derived from published equations revealed that at high D/dp ratios the measured and calculated velocity profiles behaved similarly. At low ratios, oscillations in the velocity profiles agreed with those in the voidage profiles, signifying that treating the porous medium as a continuum medium is questionable in these cases.

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Main Authors: NEGRINI,A. L., FUELBER,A., FREIRE,J. T., THOMÉO,J. C.
Format: Digital revista
Language:English
Published: Brazilian Society of Chemical Engineering 1999
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66321999000400010
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spelling oai:scielo:S0104-663219990004000102000-03-01Fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumptionNEGRINI,A. L.FUELBER,A.FREIRE,J. T.THOMÉO,J. C. Fluid Mechanics Porous Media Continuum Model Fixed Bed Velocity Measurements Bed Structure Air flow through packed beds was analyzed experimentally under conditions ranging from those that reinforce the effect of the wall on the void fraction to those that minimize it. The packing was spherical particles, with a tube-to-particle diameter ratio (D/dp) between 3 and 60. Air flow rates were maintained between 1.3 and 4.44 m3/min, and gas velocity was measured with a Pitot tube positioned above the bed exit. Measurements were made at various radial and angular coordinate values, allowing the distribution of air flow across the bed to be described in detail. Comparison of the experimentally observed radial profiles with those derived from published equations revealed that at high D/dp ratios the measured and calculated velocity profiles behaved similarly. At low ratios, oscillations in the velocity profiles agreed with those in the voidage profiles, signifying that treating the porous medium as a continuum medium is questionable in these cases.info:eu-repo/semantics/openAccessBrazilian Society of Chemical EngineeringBrazilian Journal of Chemical Engineering v.16 n.4 19991999-12-01info:eu-repo/semantics/articletext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66321999000400010en10.1590/S0104-66321999000400010
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country Brasil
countrycode BR
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databasecode rev-scielo-br
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region America del Sur
libraryname SciELO
language English
format Digital
author NEGRINI,A. L.
FUELBER,A.
FREIRE,J. T.
THOMÉO,J. C.
spellingShingle NEGRINI,A. L.
FUELBER,A.
FREIRE,J. T.
THOMÉO,J. C.
Fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumption
author_facet NEGRINI,A. L.
FUELBER,A.
FREIRE,J. T.
THOMÉO,J. C.
author_sort NEGRINI,A. L.
title Fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumption
title_short Fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumption
title_full Fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumption
title_fullStr Fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumption
title_full_unstemmed Fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumption
title_sort fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumption
description Air flow through packed beds was analyzed experimentally under conditions ranging from those that reinforce the effect of the wall on the void fraction to those that minimize it. The packing was spherical particles, with a tube-to-particle diameter ratio (D/dp) between 3 and 60. Air flow rates were maintained between 1.3 and 4.44 m3/min, and gas velocity was measured with a Pitot tube positioned above the bed exit. Measurements were made at various radial and angular coordinate values, allowing the distribution of air flow across the bed to be described in detail. Comparison of the experimentally observed radial profiles with those derived from published equations revealed that at high D/dp ratios the measured and calculated velocity profiles behaved similarly. At low ratios, oscillations in the velocity profiles agreed with those in the voidage profiles, signifying that treating the porous medium as a continuum medium is questionable in these cases.
publisher Brazilian Society of Chemical Engineering
publishDate 1999
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66321999000400010
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