analysis of flow through packed beds wjs van der merwe, cg du toit, j-h kruger north-west university...
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Analysis of flow through packed beds
WJS van der Merwe, CG du Toit, J-H Kruger
North-West University
Energy Postgraduate Conference 2013
Introduction• What is a packed bed?
• How does a packed bed work?
• Applications.– Packed bed nuclear reactors.– Catalytic reactions.– Filtration.
• Design.– Pressure drop.– Heat transfer mechanisms.– Mass transfer mechanisms.
Prediction of pressure drop• KTA 3102.3 (Nuclear Safety Standards Commission).
• Eisfeld and Schnitzlein (2001).
0.1
320 6
1 1
KTAp p
Re Re
2
(1 )w wES
p w
KA A
Re B 1.624 250D
d
Dd
mRe
Purpose of investigation• Evaluate the applicability of existing correlations which
predict the pressure drop over beds with small D/d ratios.
• Determine the applicability of the KTA limiting curve.
• Explicit approach.
• Star-CCM+.– DEM.– CFD.
Dd
mRe
Discrete Element Modelling• Generated beds in Star-CCM+ using DEM.• Exported particle centre coordinates to create domains for
CFD simulations.
2.5Dd 20D
d
Conclusions• Explicit CFD simulation results compared well with
experimental measurements from literature.
• CFD predictions compared well with the Eisfeld and Schnitzlein correlation predictions.
• The KTA limiting curve is valid, but not exact.
• Further investigation is needed to determine a definition and criteria for the KTA limiting curve.
This work is based upon research supported by the South African Research Chairs Initiative of the Department of Science and
Technology and National Research Foundation.
Thank you.