... Configuration and Principle: 1. This kind of sludge scraper consists of drive, scum launder, accessory bridge, ... rake skimmer, scum scraper, scum baffles, sludge scraper, effluent weir, central bearing seat and ... 2. As the accessory bridge rotates, the scraper thereunder scrapes the sludge along the inclined tank ... to customer's requirement and real application situation.