OA1 rotary drum screen is a new type of product developed & produced by BENENV which absorbed foreign advanced technology & combined actual condition of domestic water treatment, it is the fine screen which integrates residue collecting, conveying and dewatering together and have been widely used for municipal wastewater treatment plant. The rotary drum screen is composed of round shaped bar screens, the installation angle is 35°. Residues get blocked and stored on the screen surface while flowing by, and scraped to the top of the screen by tooth shaped scraper which is driven by motor. Residue blocked by deslagging plate dropped into the collecting hopper & delivered by central screw conveyor, and finally fell into waste cart from discharge outlet for outward transport.