After mixing with the prepared flocculation in the dynamic and static mixer, the small particles solids in the concentrated sludge would form bigger size of flocculated sludge and the free water is separated. Flocculated sludge is conveyed to the belt then it further goes to the gravity dewatering area. Under the gravity, free water would fall on the tray, and the rest sludge would be nipped between two belts. Then it would further goes to the wedge zone for pre-filtration, and then to low pressure zone and high pressure zone through the decreasing diameter rolls. Under the extrusion and shearing force, the solid and liquid is separated. Finally filter cake with expected low moisture content is discharged.