They are the most cost effective sludge dewatering systems for use in high, medium or large scale plants. In the Belt Press system that operates continuously, solid-liquid separation of squeezed sludge between rotating drums and sludge belts is made. The dewatering efficiency of the sludge, which is squeezed at low and high pressure by the drums of different diameters, is quite high. After the sludge cake is removed from the system by applying different pressures on the sludge bands, the sludge bands are washed with automatic self-cleaning nozzles in order to increase the filtration efficiency. Filtration and backwash water is delivered to the wastewater treatment plant via a discharge line. The sludge cake formed is transferred to the container or conveyor belts according to customer demand and removed from the system.