Modelling an Aerated Reactor for a Wastewater Treatment Plant

30 Pages·2007·9.69 MB·English

MMooddeelllliinngg aann AAeerraatteedd RReeaaccttoorr
ffoorr aa WWaasstteewwaatteerr
TTrreeaattmmeenntt PPllaanntt
ir. Joeri Wilms
CFD Consultant
Aeolus Consulting
© 2007 ANSYS, Inc. All rights reserved.
© 2007 ANSYS, Inc. All rights reserved.
ANSYS, Inc. Proprietary
ANSYS, Inc. Proprietary
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MMooddeelllliinngg aann AAeerraatteedd RReeaaccttoorr ffoorr aa
WWaasstteewwaatteerr TTrreeaattmmeenntt PPllaanntt
Overview:
introducing Aquafin
description of the subject of the presented
modelling work
gradual model construction
results and animations
measurements and observations
conclusions
© 2007 ANSYS, Inc. All rights reserved.
ANSYS, Inc. Proprietary
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IInnttrroodduuccttiioonn:: wwhhoo iiss AAqquuaaffiinn aanndd hhooww
ccaann CCFFDD bbee ooff aannyy hheellpp??
The modelling work presented here has been
done for and in cooperation with Aquafin NV.
Established in 1990 by the Government of Flanders
Aquafin's mission: to design, finance, build and
operate all supramunicipal infrastructure needed to
treat domestic waste water in it's region of
operation.
2006: 737 employees, operating income ~289
million, 210 installations, 905 pumpstations, 4053km
piping
© 2007 ANSYS, Inc. All rights reserved.
ANSYS, Inc. Proprietary
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IInnttrroodduuccttiioonn:: wwhhoo iiss AAqquuaaffiinn aanndd hhooww
ccaann CCFFDD bbee ooff aannyy hheellpp??
To perform it's tasks, Aquafin builds upon a long
term practical experience, theoretical knowledge
and ongoing research.
Modelling and computer models are widely used
in Aquafin's operations.
main topics in
ongoing
research
© 2007 ANSYS, Inc. All rights reserved.
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IInnttrroodduuccttiioonn:: eexxaammpplleess ooff CCFFDD--mmooddeelllliinngg
aatt AAqquuaaffiinn
Ludwig Buts, Aquafin R&D
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IInnttrroodduuccttiioonn:: CCFFDD--mmooddeelllliinngg aatt AAqquuaaffiinn
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AAeerraatteedd RReeaaccttoorr ffoorr wwaassttee wwaatteerr
ttrreeaattmmeenntt:: ddeessccrriippttiioonn
© 2007 ANSYS, Inc. All rights reserved.
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AAeerraatteedd RReeaaccttoorr ffoorr wwaassttee wwaatteerr
ttrreeaattmmeenntt:: ddeessccrriippttiioonn
waste water inlet
to the next unit
air injection
© 2007 ANSYS, Inc. All rights reserved.
ANSYS, Inc. Proprietary
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AAeerraatteedd RReeaaccttoorr ffoorr wwaassttee wwaatteerr
ttrreeaattmmeenntt:: ddeessccrriippttiioonn
© 2007 ANSYS, Inc. All rights reserved.
ANSYS, Inc. Proprietary
9
AAeerraatteedd RReeaaccttoorr ffoorr wwaassttee wwaatteerr
ttrreeaattmmeenntt:: mmooddeelllliinngg qquueessttiioonnss
Problem:
Air-injection strongly affects the overall flow
pattern of the circulating water.
In some aerated reactors sedimentation occurs.
leading to short maintenance intervals
sub-optimal operation
The effects on overall flow pattern are poorly
understood.
Question:
can CFD reproduce the observed flow patterns
and help to explain them?
can this be done using relatively cheap modelling
techniques?
© 2007 ANSYS, Inc. All rights reserved.
ANSYS, Inc. Proprietary
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