Flow Structure of the Solids in a Three-Dimensional Liquid Fluidized Bed

The motion of solids in a cylindrical liquid fluidized bed was experimentally characterized by means of a noninvasive radioactive particle tracking technique (RPT) for two monosized bed inventories, spherical glass beads (3 mm GB, density = 2500 kg/m3) and nonspherical poly-(vinyl chloride) particle...

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Autor principal: Cassanello Fernández, Miryam Celeste
Publicado: 1997
Materias:
Anisotropy
Flow patterns
Fluidized beds
Glass
Polyvinyl chlorides
Radioactive tracers
Shear stress
Turbulence
Velocity measurement
Lagrangian trajectory
Radioactive particle tracking (RPT) technique
Flow of fluids
flow field
fluidized bed
particle
solid flow
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08885885_v36_n11_p4695_Kiared
http://hdl.handle.net/20.500.12110/paper_08885885_v36_n11_p4695_Kiared
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_08885885_v36_n11_p4695_Kiared
record_format dspace
spelling paper:paper_08885885_v36_n11_p4695_Kiared2023-06-08T15:46:56Z Flow Structure of the Solids in a Three-Dimensional Liquid Fluidized Bed Cassanello Fernández, Miryam Celeste Anisotropy Flow patterns Fluidized beds Glass Polyvinyl chlorides Radioactive tracers Shear stress Turbulence Velocity measurement Lagrangian trajectory Radioactive particle tracking (RPT) technique Flow of fluids flow field fluidized bed particle solid flow The motion of solids in a cylindrical liquid fluidized bed was experimentally characterized by means of a noninvasive radioactive particle tracking technique (RPT) for two monosized bed inventories, spherical glass beads (3 mm GB, density = 2500 kg/m3) and nonspherical poly-(vinyl chloride) particles (5.5 mm PVC, density = 1300 kg/m3). RPT-monitoring of a single radioactive solid tracer mimicking faithfully the characteristics of the solids revealed the detailed solids flow features by determining the tracer instantaneous 3-D Lagrangian trajectory and then its local instantaneous velocities. Transverse solids dispersion coefficients were an order of magnitude lower than their axial counterpart. Time, longitudinal, and circumferential averaging of local velocities in the fully developed region of the fluidized bed revealed a weak gulf streaming characterized by axial velocities positive (respectively negative) in the core and negative (respectively positive) near the vessel walls for the GBs (respectively for the PVCs). The measured mean circumferential ensemble-averaged radial velocity was essentially zero in the fully developed region. The solids flow turbulence field was anisotropic, but the less dense the particles, the closer to isotropy was the solids flow. Computed shear stress profiles showed that PVC particles exhibited a higher shear stress than GB particles. The dynamic solids flow structure inside a 3-D liquid fluidized bed can be viewed as a core-annulus structure with axially-dispersed plug-flow and radial dispersion in each of the upward and downward zones. Fil:Cassanello, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1997 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08885885_v36_n11_p4695_Kiared http://hdl.handle.net/20.500.12110/paper_08885885_v36_n11_p4695_Kiared
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Anisotropy
Flow patterns
Fluidized beds
Glass
Polyvinyl chlorides
Radioactive tracers
Shear stress
Turbulence
Velocity measurement
Lagrangian trajectory
Radioactive particle tracking (RPT) technique
Flow of fluids
flow field
fluidized bed
particle
solid flow
spellingShingle Anisotropy
Flow patterns
Fluidized beds
Glass
Polyvinyl chlorides
Radioactive tracers
Shear stress
Turbulence
Velocity measurement
Lagrangian trajectory
Radioactive particle tracking (RPT) technique
Flow of fluids
flow field
fluidized bed
particle
solid flow
Cassanello Fernández, Miryam Celeste
Flow Structure of the Solids in a Three-Dimensional Liquid Fluidized Bed
topic_facet Anisotropy
Flow patterns
Fluidized beds
Glass
Polyvinyl chlorides
Radioactive tracers
Shear stress
Turbulence
Velocity measurement
Lagrangian trajectory
Radioactive particle tracking (RPT) technique
Flow of fluids
flow field
fluidized bed
particle
solid flow
description The motion of solids in a cylindrical liquid fluidized bed was experimentally characterized by means of a noninvasive radioactive particle tracking technique (RPT) for two monosized bed inventories, spherical glass beads (3 mm GB, density = 2500 kg/m3) and nonspherical poly-(vinyl chloride) particles (5.5 mm PVC, density = 1300 kg/m3). RPT-monitoring of a single radioactive solid tracer mimicking faithfully the characteristics of the solids revealed the detailed solids flow features by determining the tracer instantaneous 3-D Lagrangian trajectory and then its local instantaneous velocities. Transverse solids dispersion coefficients were an order of magnitude lower than their axial counterpart. Time, longitudinal, and circumferential averaging of local velocities in the fully developed region of the fluidized bed revealed a weak gulf streaming characterized by axial velocities positive (respectively negative) in the core and negative (respectively positive) near the vessel walls for the GBs (respectively for the PVCs). The measured mean circumferential ensemble-averaged radial velocity was essentially zero in the fully developed region. The solids flow turbulence field was anisotropic, but the less dense the particles, the closer to isotropy was the solids flow. Computed shear stress profiles showed that PVC particles exhibited a higher shear stress than GB particles. The dynamic solids flow structure inside a 3-D liquid fluidized bed can be viewed as a core-annulus structure with axially-dispersed plug-flow and radial dispersion in each of the upward and downward zones.
author Cassanello Fernández, Miryam Celeste
author_facet Cassanello Fernández, Miryam Celeste
author_sort Cassanello Fernández, Miryam Celeste
title Flow Structure of the Solids in a Three-Dimensional Liquid Fluidized Bed
title_short Flow Structure of the Solids in a Three-Dimensional Liquid Fluidized Bed
title_full Flow Structure of the Solids in a Three-Dimensional Liquid Fluidized Bed
title_fullStr Flow Structure of the Solids in a Three-Dimensional Liquid Fluidized Bed
title_full_unstemmed Flow Structure of the Solids in a Three-Dimensional Liquid Fluidized Bed
title_sort flow structure of the solids in a three-dimensional liquid fluidized bed
publishDate 1997
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08885885_v36_n11_p4695_Kiared
http://hdl.handle.net/20.500.12110/paper_08885885_v36_n11_p4695_Kiared
work_keys_str_mv AT cassanellofernandezmiryamceleste flowstructureofthesolidsinathreedimensionalliquidfluidizedbed
_version_ 1768544090616496128

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