Sheffield
Dégrilleurs fins

Installation of a Fine Screen MC-56 and a compactor to improve operations and maintenance.

Background

Sheffield Utilities, a public utility owned by the City of Sheffield in northwest Alabama, operates a 6 MGD facility which utilizes an extended aeration process to treat its waste water. The facility was originally operating without fine screening, but in 2002 the City of Sheffield proposed to improve the operations, by upgrading its headworks.

The case

The City of Sheffield retained the services of “Bill Cobb and Associates” to design and prepare the tender documents for a new head works facility. The consulting engineer proposed to use a fine screen to reduce the plant loading and remove the maximum amount of non-biological material before processing the raw effluent at the facility.

The chosen screen design was a traveling,continuous filter band type screen, a proven design that has

been the screen of choice in hundreds of municipal plants worldwide.
The choice of the screen and compactor supplier was very important to Plant Manager Randy Burrows and his team. Their goal was to improve operations while reducing the maintenance costs to a minimum.
Spaans Babcock Fine Screen and Compactor at Sheffield Engineer Bill Cobb during the Fine Screen installation Spaans Babcock RWK washer compactor

The solution

Sheffield Utilities chose the Spaans Babcock MC 56 Fine Screen and a screenings compactor to be installed at the plant.
The Spaans Babcock Fine Screen offers a superior performance to traditional filter band type screens due to its proprietary Block Design. With this design, filter blocks can be easily removed for maintenance, with the screen remaining in continuous operation.

The benefits

Randy Burrows commented positively on the experience: “We have improved our process while minimizing additional maintenance. The solids removal has improved markedly. Spaans Babcock was efficient and responsive throughout the project, and their people made sure that the system was running smoothly.”

Installing Spaans Babcock screens and compactors offers many advantages:

1. High efficiency of solids removal, combined with low hydraulic loss and a low noise level.
2. Quick and easy removal of the filter element blocks, even during the screen operation.
3. Removal of a filter block does not take the screen out of service.
4. Unlike other fine screens, the Spaans Babcock screen exhibits low wear since there is no friction between the filter elements and shafts, and the elements themselves are not interconnected.
5. Increased versatility – ability to modify the slot width between filter elements at a low cost. The slot width is generally between 2.5 to 25 mm.
6. The filter elements are cleaned with a high speed brush, on a separate drive, and with two water sprays.
7. The screens can be mounted in existing channels, with minimal space in between two screens.
8. The Block design allows much wider screen spans of up to 4.2 m without the need of a centre chain.
9. Superior compaction capabilities, meeting the most stringent environmental standards. Models, such as the sophisticated RWK washer / compactor can reach volume reduction of up to 70%, weight reduction of up to 80% and dry solid content reduction of up to 50%.