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CFD and PIV investigation of UV reactor hydrodynamics Sozzi, Angelo
Abstract
The performance of ultraviolet (UV) reactors used for water treatment is greatly influenced by the reactor hydrodynamics, due to the non-homogeneity of the UVradiation field. Yet, a present lack of rigorous quantitative understanding of the flow behavior in such reactor geometries is shown to limit the versatile and efficient optimization of UV reactors. In this research, the key characteristics of turbulent flow in annular UV-reactors and its influence on reactor performance were studied using particle image velocimetry (PIV) measurements and computational fluid dynamics (CFD) simulations. Two conceptual reactor configurations, with inlets either concentric (L-shape) or normal (U-shape) to the reactor axis, were investigated experimentally. The time averaged velocity data revealed a strong dependency of the hydrodynamic profile to the inlet position. The frontal inlet of the L-shape reactor resulted in an expanding jet flow with high velocities close to the radiation source (UV-lamp) and areas of recirculation close to the inlet. The perpendicular inlet of the U-shape reactor brought about higher velocities along the outer reactor walls far from the central lamp. Numerical simulations, using a commercial CFD software package, Fluent, were performed for the L- and U-shape reactor configurations. The influences of mesh structure and the Standard n-e, Realizable K-e, and Reynolds stress (RSM) turbulence models were evaluated. The results from the Realizable «-e and RSM models were in good agreement with the experimental findings. However, the Realizable K-e model provided the closest match under the given computational restraints. UV disinfection models were developed by integrating UV-fluence rate and inactivation kinetics with the reactor hydrodynamics. Both, a particle tracking (Lagrangian) random walk model and a volumetric reaction rate based (Eulerian) model were implemented. The performance results of the two approaches were in good agreement with each other and with the experimental data from an industrial prototype reactor. The simulation results provided detailed information on the velocity profiles, reaction rates, and areas of possible short circuiting within the UV-reactor. It is expected that the application of the verified integrated CFD models will help to improve the design and optimization of UV-reactors.
Item Metadata
Title |
CFD and PIV investigation of UV reactor hydrodynamics
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2005
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Description |
The performance of ultraviolet (UV) reactors used for water treatment is greatly
influenced by the reactor hydrodynamics, due to the non-homogeneity of the UVradiation
field. Yet, a present lack of rigorous quantitative understanding of the
flow behavior in such reactor geometries is shown to limit the versatile and efficient
optimization of UV reactors. In this research, the key characteristics of turbulent
flow in annular UV-reactors and its influence on reactor performance were studied
using particle image velocimetry (PIV) measurements and computational fluid
dynamics (CFD) simulations.
Two conceptual reactor configurations, with inlets either concentric (L-shape)
or normal (U-shape) to the reactor axis, were investigated experimentally. The
time averaged velocity data revealed a strong dependency of the hydrodynamic
profile to the inlet position. The frontal inlet of the L-shape reactor resulted in
an expanding jet flow with high velocities close to the radiation source (UV-lamp)
and areas of recirculation close to the inlet. The perpendicular inlet of the U-shape
reactor brought about higher velocities along the outer reactor walls far from the
central lamp.
Numerical simulations, using a commercial CFD software package, Fluent, were
performed for the L- and U-shape reactor configurations. The influences of mesh
structure and the Standard n-e, Realizable K-e, and Reynolds stress (RSM) turbulence
models were evaluated. The results from the Realizable «-e and RSM models
were in good agreement with the experimental findings. However, the Realizable
K-e model provided the closest match under the given computational restraints.
UV disinfection models were developed by integrating UV-fluence rate and
inactivation kinetics with the reactor hydrodynamics. Both, a particle tracking
(Lagrangian) random walk model and a volumetric reaction rate based (Eulerian)
model were implemented. The performance results of the two approaches were in
good agreement with each other and with the experimental data from an industrial
prototype reactor. The simulation results provided detailed information on the
velocity profiles, reaction rates, and areas of possible short circuiting within the
UV-reactor. It is expected that the application of the verified integrated CFD
models will help to improve the design and optimization of UV-reactors.
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Genre | |
Type | |
Language |
eng
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Date Available |
2009-12-15
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0058979
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2005-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
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Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.