We manufacture scrapers with central drive to round and square preliminary clarification basins. The operating gear is installed on a bridge above the basin or on the deck structure. Scraper blades attached to the centre shaft transport bottom sludge to the sludge drain in the middle of the basin’s bottom. The scraper plates in the blades are shaped like a logarithmic curve, or they are straight plate blades installed at an angle. The clarified water is removed from the base as overflow to the next process step.