Centrifuges are used for the mechanical separation of mixtures (sludge, sediments) consisting of a solid and a liquid phase in many industries: food, textile, ore mining, and many others, as well as in wastewater treatment plants.
A decanter centrifuge refers to a centrifugal apparatus used to separate media consisting of a solid and a liquid phase with different densities into separate fractions. A centrifuge consists of a conical-cylindrical drum, a screw inside the drum, a supply pipe, a drive system, bearing mechanisms, polymer dosing unit, a housing and a frame. Centrifuges are continuous-action devices.
The decanter centrifuges deposit solid particles with a density greater than the that of the liquid phase by the centrifugal force on the inner wall of a cylindrical (or cylindrical-conical) rotor, with settling heavier particles first and then lighter ones. The settled particles are transported by the screw to the discharge opening. To move the settled sediment particles, the screw rotates at a speed greater or less than the speed of the rotor. The effluent merges through the drainage openings in the rotor. Varying the diameter of the drain holes allows changing the quality of the effluent and the humidity of the dehydrated sediment. Centrifuges can achieve high rates of sludge dewatering with and without flocculant, which significantly expands their scope of application.