Method of cleaning filter medium of gravity sand filter and filtering apparatus

摘要

The solution concerns the method of cleaning the filter cartridge of the gravity sand filter and the filter device. The filter cartridge is placed on a tray, under which pressurized air is fed, which penetrates through the openings into the filter cartridge and, on the way to its surface, releases turbidity into the water layer above the filter cartridge, which is subsequently drained together with water. The pressurized air supplied to the intermediate chamber extrudes the filtered water from the space below the interim to the filtered water tank. The volume of pressurized air supplied per time unit is greater than the volume of effluent discharged into the filtered water tank. The time required to initially crack the filter bed and subsequently drop the pressure below the filter gap is shorter than the time required to displace such a quantity of water from the space below the interspace that air escapes from the space to the filtered water tank. The filtration equipment is described below.