Automatic self cleaning screen filter

During normal filtering mode the raw water enters the inlet [1] of the filter, passes through the coarse screen [2]. Water then travels to the inside and through the fine screen [3] to the outlet [4]. As more water flows through, impurities build up on the fine screen. As impurities on the screen accumulate, a pressure imbalance is built up between the internal section of the fine screen and its external section. At a preset pressure the controller activates the autowash cycle by opening the flush valve [5] to drain (atmosphere). Pressure in the hydraulic motor chamber [6] and the dirt collector [7] is significantly lowered, and the dirt collector nozzles [8] begin a suction process. The hydraulic piston [9] moves this assembly down the length of the fine screen in a spiraling motion, cleaning the entire screen surface area. The flushing valve closes at the end of the cycle and the increased water pressure returns the hydraulic piston to its initial position. The filter is now ready for the next cycle, with clean and filtered water flowing through the outlet.