The Copatrawl sac screening system provides, screening down to 6mm with no moving parts, using disposable trawl sacs. The CopaTrawl System can be made to fit into most sewage treatment applications, be it retrofit to an existing works or as part of a new scheme.
Applications
The CopaTrawl applications are on settled sewage protecting travelling filter arms on rectangular trickling filters, to improve the integrity of the works by protecting the filter arm sparge nozzles from blockage.
The applications for the CopaTrawl System have spread to include screening storm overflows, storm tanks and final effluent. The Copasac and the CopaTrawl System have been proven to reduce works visit frequency, due to better distribution of effluent to the filter bed.
Typical Applications
- Filter arm protection on trickling filters.
- Emergency/storm overflow screen.
- Screening of final effluent.
Operating Principle
The CopaTrawl System can be installed directly into the flow path of the fluid being screened. Solids are retained in the sac, therefore preventing downstream problems, such as clogging of trickling filters, or aesthetic pollution of surface waters following a storm event. Unlike it’s sister product, the Copasac System, the CopaTrawl System is designed to screen much larger flows. Each CopaTrawl sac can screen 150l/s.
The CopaTrawl System has been proven to reduce works visit frequency, and better distribution of effluent to the filter bed.
It is recommended that a lifting davit should be used as minimum requirement to facilitate removal of the CopsTrawl sac from the flow chamber.
Advantages
- Simple operation
- Low cost
- Easy installation
- Proven to reduce works maintenance
- Improve distribution of effluent to the filter bed
- Wide use of applications