Gravity type sludge thickening

Sludge thickening is the process of reducing the water content in the sludge to a consistency where the sludge remains fluid and pumpable. Thickening is mainly used to reduce the volume in subsequent sludge dewatering processes. Generally, raw sludge is fed to the thickening tank from the center. While the sludge is pushed into the pit in the center of the tank with the scraper blades at the bottom, the sludge is sucked from here for dewatering. Often, vertical rods are placed on the scraper arms to ensure light mixing of the sludge in the thickeners. In continuous feed type thickeners, a submersible curtain and weir system is used to remove the sludge upper water. In batch systems, there are devices to decant the sludge upper water.