Brackett Green® Straight Through Traveling Band
Brackett Green Straight Through Traveling Band screens are designed for installation on raw water intakes, where continuous and efficient methods of removing floating and suspended solids are required to protect critical equipment.
These band screens can be installed as a single system or as part of a two- or three-stage system for raw water intakes. Mesh aperture sizes can vary from 1.5 mm to 10 mm (5/64 in to 3/8 in).
Brackett Green Straight Through Traveling Band Screens are the most effective screening solution on the market. This heavy-duty and durable system provides a large screening area in a compact footprint. The system is known for its low operating costs and downstream maintenance. The framed design reduces civil works and installation costs and its simplified maintenance procedure, involving replaceable roller tracks and wear strips, can prolong operational life and reduces downtime.
Integrating important environmental innovations
Ovivo offers a unique behavioural screening system that complies with current best practices for large cooling water intakes and demonstrates Ovivo’s steadfast commitment to the environment.
A fully customisable system
Brackett Green Straight Through Traveling Band Screens consist of an endless band of mesh panels contained within a vertical self-supporting frame. The water being screened will pass from the upstream side of the screen, through the mesh panels to the downstream side through a series of descending mesh panels. As the band of mesh panels rotates, the debris collected on the upstream side of the mesh panel is lifted above deck level, where it is washed off into a debris trough.
Brackett Green Straight Through Traveling Band Screens are custom-designed for each application to minimise capital costs, and can incorporate specific features to suit individual operating and site conditions, such as Dual Flow, Central Flow and Through Flow options.
- Dual flow: Ovivo’s experience designing band screens for water intakes confirms that the dual flow (DF), or out-to-in flow pattern, is the most suitable flow pattern for the majority of water intakes. With this pattern the water exits through the back opening after flowing through the mesh panels to the inside of the screen. The dual flow prohibits screenings from being carried over to the downstream side of the screen. The dual flow pattern converges the water to the centre of the channel on the downstream side, which is preferable for a close proximity pump.
- Central flow: For some applications a central flow (CF) pattern, or into-out flow pattern, is sometimes preferred. With this flow pattern, the water passes into the centre of the screen frame and then out through the mesh panels to the clean side of the screen. This flow pattern also prevents debris carry over and is more commonly supplied as a “frameless” design.
- Through flow: The through flow (TF) pattern has the advantage of a simplified civil structure compared with DF and CF Band Screens, but unlike DF and CF, it does not eliminate debris carryover. Ovivo can design and supply screens to this flow pattern. For existing through flow installations Ovivo can also offer a through flow to dual flow conversion allowing the benefits of a DF screen to be realised without modification to the existing civil structure.
The main chains and sprockets carry the screening band, which is powered by an electric motor and shaft-mounted gear unit. Water passes through the endless band of screening panels with mesh aperture sizes ranging from 1.5 mm to 10 mm (5/64 in to 3/8 in). Any debris collected on the mesh panels is raised to deck level and removed by a spray wash system. While underwater, the main chain runs through a thick stainless track system and replaceable track guides. An optional full-contact seal, made of flexible neoprene and attached to the main structure, runs in contact with the main chain sealing fins and is recommended for flows where fine mesh or particular types of debris may bypass the screen.