A circular or cylindrical tank equipped with revolving rakes or plows so designed as to increase the concentration of solids in a suspension. The slurry enters through a feed trough or well, which distributes it uniformly around the circumference of the tank; the rakes move the thickened sediment toward the center where it is discharged through a collecting cone. Thickeners are applicable to the metallurgical and food industries, ore flotation, and municipal water treatment.See Clarification.