CopaTrawl™ Screen

The CopaTrawl™ system is installed directly into the flow path of the wastewater being screened. Solids are retained in the sack, thereby preventing downstream problems such as clogging of trickling filters or the pollution of surface waters following a storm event.

The CopaTrawl™ screen can handle larger flows than its sister product, the CopaSac® screen and flows of up to 150 l/sec can be passed through a single sac. However, there is no limitation on the number of trawls that can be used, other than the space requirement. An average trawl change frequency (based on settled sewage) is every 3 to 4 events

It is recommended that a lifting davit is used as a minimum requirement to facilitate removal of the trawl sack from the flow chamber.

The CopaTrawl™ screening system is capable of screening down to 6mm of settled sewage and can be made to fit into most sewage treatment applications as part of a new scheme or as a retrofit into existing works. Other applications include screening storm overflows, storm tanks and final effluent. CopaTrawl™ can be used as a permanent and a temporary screening solution.

The CopaTrawl has 4 mesh size applications 6mm 7.5mm 12mm 25mm for various process streams such as Settled Primary Sewage, Final Effluent, Discharge from Storm Tanks, Storm Overflow and Emergency Overflows.

The disposable trawl sac is attached to a stainless steel nose box by hooks. The nose box is situated in a modular GRP slider section for easy removal. The trawl sac should be disposed of when it is about a quarter full. A draw cord ensures that the clean screenings remain within the trawl sac.