The invention is directed to methods of providing backwash processes for a synthetic compressible medium filter system. More specifically, the system may include a backwash pump and air blower, and the processes may include at least three sequences of: air and water wash; air purge; and medium compression. The backwash process may be triggered by one or more of a pressure, time point, and/or turbidity set point. The air and water wash sequence may include breaking and washing the medium. The air purge sequence may include removing substantially all of the air entrapped in the medium by providing a backwash water flow for a period of time; and a medium compression sequence compressing the medium while avoiding exposing the medium to air, including introducing raw water and where the backwash and raw water provide enough energy to compress the medium without introduction of air into the medium.

The invention relates to a clearing apparatus (I), especially for clearing and/or maintaining of filter basins (7), consisting of at least one carrier (1), at least one undercarriage (2), at least one removal device (3), at least one driving device (4) and at least one pushing or guiding device (10), wherein the removal device (3) is situated in the front and/or before the undercarriage (2) and/or in front of an axle (21) of the undercarriage (2) in the travel and/or removal direction (a), the pushing or guiding device (10) is provided at the rear in the travel and/or removal direction (a), and wherein the removal device (3) comprises a platform (32) on which a drivable or driven removal means is circulating, such as a drivable or driven flexible circulating chain (31) and/or a flexible circulating belt (31), in order to remove material from a bottom (71) of the filter basin (7), transport it away and/or dispose of it.

Controlled-debris elements inhibit the formation of a fibrous/particulate debris bed that unduly increases the pressure head loss through the perforated plates of strainers in a nuclear power plant emergency core cooling system. In a loss of cooling accident, pumps draw cooling water through the plates, which retain on their surfaces fibrous material in the circulating water to prevent it from reaching the pumps while permitting entrained particulate matter to pass through the perforations. The controlled-debris elements have a specific gravity substantially the same as the circulating water so they are entrained in the cooling water that is drawn toward the strainers and intimately intermix with the fibrous and particulate matter in the cooling water. The elements are configured to provide open structures in the bed formed on the plate surfaces to distribute fibers in the flow away from the surface and maintain cavities between the elements for the particulates.

The present disclosure a mechanical filter element (2) for forming a static filter pack (11) to perform mechanical filtration of a liquid. The mechanical filter element (1) has one or more filter cell (19). The present disclosure also relates to a mechanical filter apparatus (1) having a filter chamber (10) containing a plurality of mechanical filter elements (2) for forming the static filter pack (11) to perform mechanical filtration of a liquid. The mechanical filter apparatus (1) is configured to generate a flow of the liquid through the mechanical filter elements (2) during filtration to form the static filter pack (11). Furthermore, the present disclosure relates to a method of mechanically filtering a liquid. A plurality of mechanical filter elements (2) each comprising one or more filter cell (19) are disposed in a filter chamber (10). During filtration, the liquid flows through the filter chamber (10) to establish a static filter pack (11) of said mechanical filter elements (2) to mechanically filter the liquid.

Exemplary systems and methods relating to washboxes are described.

The invention is directed to methods of providing backwash processes for a synthetic compressible medium filter system. More specifically, the system may include a backwash pump and air blower, and the processes may include at least three sequences of: air and water wash; air purge; and medium compression. The backwash process may be triggered by one or more of a pressure, time point, and/or turbidity set point. The air and water wash sequence may include breaking and washing the medium. The air purge sequence may include removing substantially all of the air entrapped in the medium by providing a backwash water flow for a period of time; and a medium compression sequence compressing the medium while avoiding exposing the medium to air, including introducing raw water and where the backwash and raw water provide enough energy to compress the medium without introduction of air into the medium.

A continuous backwash upflow media filter comprises a container having a conical bottom; a wastewater influent tube having an opening within the container; an effluent weir within the container and an effluent tube with an opening in the effluent weir; a reject weir within the container below the effluent weir and a reject tube with an opening in the reject weir; an inverted deflection cone within the container positioned below the opening of the wastewater influent tube forming an annular space between the inverted deflection cone and the conical bottom of the container; an airlift pipe having a lower opening below the inverted deflection cone and below the annular space; and a sludge lift tube having a lower opening inside the media-free cavity formed by the inverted deflection cone above the annular space and an upper opening adapted to discharge sludge out of the container.