Numerical prediction of the performance of horizontal sand filters as the pitch of the spiral protrusion changes

Mossad, Ruth and Aral, Hal (2013) Numerical prediction of the performance of horizontal sand filters as the pitch of the spiral protrusion changes. Water Science and Technology, 67 (10). pp. 2249-2256. ISSN 0273-1223

Abstract

The height of vertical sand filters are limited due to their structural cost. A horizontal sand filter may offer a better alternative, however flow channels to the least resistance zone generated at the top of the filter as the sand gets wet and settles. A horizontal sand filter, internally baffled with spiral protrusion, is numerically modelled to study the effect of these spirals in reducing the channelling and enhancing filter's effectiveness. Three different spiral pitches, 1.0 m, 0.75 m, and 0.5 m have been numerically modelled using Ansys Fluent software. The parameters investigated were the power needed to run a flow rate through the horizontal filter and the residence time. The results show that as the spiral pitch decreases the channelling reduces while the power increases. The power needed to pump a given flow rate of water in a 10m long horizontal filter in all three cases investigated was less than the power needed to pump the same flow rate to the top of a 10 m long vertically-standing sand filter. Results also showed that the time required traversing the flow through the sand filter increases in a nonlinear fashion as the pitch size decreases, however the effectiveness of the filter increases.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to published version due to publisher copyright policy (IWA).
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering
Date Deposited: 16 May 2013 06:05
Last Modified: 10 Jul 2014 23:55
Uncontrolled Keywords: CFD modelling; channelling; porous media; sand filter; wastewater treatment
Fields of Research : 09 Engineering > 0904 Chemical Engineering > 090410 Water Treatment Processes
09 Engineering > 0905 Civil Engineering > 090508 Water Quality Engineering
09 Engineering > 0913 Mechanical Engineering > 091307 Numerical Modelling and Mechanical Characterisation
Socio-Economic Objective: D Environment > 96 Environment > 9609 Land and Water Management > 960908 Mining Land and Water Management
Identification Number or DOI: 10.2166/wst.2013.112
URI: http://eprints.usq.edu.au/id/eprint/22775

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