Abstract

Sharp inlets, although prevalent, tend to reduce mixing efficiency in hydraulic contact tanks by affecting fluid and scalar transport throughout the entire system. Superior inlets are often not an option because of the prohibitive cost of upgrading preexisting tanks. To remedy this, seven inexpensive yet easily implemented attachments to a sharp inlet were tested on a full-scale, baffled, prototypical contact tank. Cumulative residence time distributions of a conservative, passive scalar were obtained for each attachment to assess their performance. A study using computational fluid dynamics of the same tank with the various attachments was then performed to strengthen the empirical results by explaining them from a hydrodynamic perspective. Six modifications improved mixing efficiency as estimated by the baffling factor parameter. Five of these modifications produced gains of roughly 30% over the unmodified scenario, whereas the horizontal tee attachment resulted in an increase of over 70%.

Department(s)

Civil, Architectural and Environmental Engineering

Publication Status

Full Access

Keywords and Phrases

Baffling factor; Computational fluid dynamics; Contact tank; Drinking water; Hydraulics; Water disinfection

International Standard Serial Number (ISSN)

1551-8833; 0003-150X

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 John Wiley & Sons, All rights reserved.

Publication Date

01 Jun 2015

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