A bar screen is a mechanical filter used to remove large objects, such as rags and plastics, from wastewater. It is part of the primary filtration flow and typically is the first, or preliminary, level of filtration, being installed at the influent to a wastewater treatment plant. They typically consist of a series of vertical steel bars spaced between 1 and 3 inches apart.
Bar screens come in many designs. Some employ automatic cleaning mechanisms using electric motors and chains, some must be cleaned manually by means of a heavy rake. Items removed from the influent are called screenings and are collected in dumpsters and disposed of in landfills. As a bar screen collects objects, the water level will rise, and so they must be cleared regularly to prevent overflow.
|Wikimedia Commons has media related to Rake bar screens.|
- Streicher, Dennis. "Waste Water Treatment Plant Elmhurst, Illinois A Virtual Tour". Elmhurst College. Archived from the original on 29 March 2012. Retrieved 18 February 2012.
- Spellman, Frank R. (2010). Spellman's Standard Handbook for Wastewater Operators, Volume 3. CRC Press. ISBN 1439818886.
- Ragsdale, Fred. Wastewater System Operators Manual (PDF). Ragsdale and Associates Training Specialists, LLC.