Abstract: The present invention discloses a double-layer foldable lifting desk with a lever-type unlocking structure and relates to the technical field of foldable lifting desks. The double-layer foldable lifting desk with the lever type unlocking structure includes a desktop board, wherein a lower side of the desktop board is connected to an X-shaped lifting frame, a lower end of which is connected to a bottom frame; a limiting shaft is arranged at one end of an upper side of the X-shaped lifting frame; one side of the bottom of the desktop board is connected through a bolt to a guide rail, which is slidingly connected to two ends of the limiting shaft; and an unlocking mechanism corresponding to the limiting shaft is arranged on a lower side of one end of the desktop board.

Abstract: A backwash header for a cloth filter disk includes a body having a length a diameter, first and second ends, a longitudinal axis, and an exterior surface, the body defining at least one internal cavity. The body includes at least one suction slot configured to allow fluids and solids to enter the internal cavity from outside of the exterior surface. A structure is attached to a portion of the exterior surface of the body around and extending away from the suction slot to form a chamber defined by the structure and a portion of the exterior surface near the suction slot. The structure is configured to allow fluids and solids to enter the chamber and then the suction slot and cavity from a material being cleaned. Cloth disk filters and methods of treating water and wastewater using the backwash headers and cloth disk filters.

Abstract: Methods and apparatus for treating water and wastewater include the step of flowing a suspended solids stream generally upward through a sludge blanket region of a cloth disk filter vessel, thus forming a partially treated effluent composition and a solids-enriched sludge blanket. The partially treated effluent composition is allowed to flow generally upward to a cloth filter zone in the vessel after contacting the sludge blanket. The methods include flowing the suspended solids stream through one or more distribution headers positioned in the sludge blanket. An option is to provide a sludge concentration zone in the sludge blanket region, allowing sludge to flow into the sludge concentration zone to form concentrated sludge. Other methods and apparatus include backwash assemblies that backwash substantially the entire filter cassette surfaces, with or without use of a sludge blanket zone. Either the backwash assemblies or filter cassettes move in the latter methods and apparatus.

Abstract: A backwash header for a cloth filter disk includes a body having a length a diameter, first and second ends, a longitudinal axis, and an exterior surface, the body defining at least one internal cavity. The body includes at least one suction slot configured to allow fluids and solids to enter the internal cavity from outside of the exterior surface. A structure is attached to a portion of the exterior surface of the body around and extending away from the suction slot to form a chamber defined by the structure and a portion of the exterior surface near the suction slot. The structure is configured to allow fluids and solids to enter the chamber and then the suction slot and cavity from a material being cleaned. Cloth disk filters and methods of treating water and wastewater using the backwash headers and cloth disk filters.

Abstract: Methods and apparatus for treating water and wastewater include the step of flowing a suspended solids stream generally upward through a sludge blanket region of a cloth disk filter vessel, thus forming a partially treated effluent composition and a solids-enriched sludge blanket. The partially treated effluent composition is allowed to flow generally upward to a cloth filter zone in the vessel after contacting the sludge blanket. The methods include flowing the suspended solids stream through one or more distribution headers positioned in the sludge blanket. An option is to provide a sludge concentration zone in the sludge blanket region, allowing sludge to flow into the sludge concentration zone to form concentrated sludge. Other methods and apparatus include backwash assemblies that backwash substantially the entire filter cassette surfaces, with or without use of a sludge blanket zone. Either the backwash assemblies or filter cassettes move in the latter methods and apparatus.

Abstract: A liquid filtering apparatus is placed in a vessel having a bed of filtration material, the bed comprising at least two different sizes of filter media wherein the filtration material is stratified using upper and lower spaced apart inverted cones so that the unfiltered liquid first contacts coarse grained filtration material and then finer grained filtration material. The apparatus includes an intake for introducing unfiltered liquid that includes a washbox, an airlifting tube extending from the washbox and including an intake end and means for introducing a primary gas to the airlifting tube, the airlifting tube passing through a central pipe, which extends from just below the washbox to a position just above the intake end. The apparatus is devoid of screen cartridges. Methods of filtering and cleaning the filtration material are also disclosed.

Abstract: A liquid filtering apparatus is placed in a vessel having a bed of filtration material, the bed comprising at least two different sizes of filter media wherein the filtration material is stratified using upper and lower spaced apart inverted cones so that the unfiltered liquid first contacts coarse grained filtration material and then finer grained filtration material. The apparatus includes an intake for introducing unfiltered liquid that includes a washbox, an airlifting tube extending from the washbox and including an intake end and means for introducing a primary gas to the airlifting tube, the airlifting tube passing through a central pipe, which extends from just below the washbox to a position just above the intake end. The apparatus is devoid of screen cartridges. Methods of filtering and cleaning the filtration material are also disclosed.

Abstract: A liquid filtering apparatus is placed in a vessel having a bed of filtration material and an intake for introducing unfiltered liquid, that includes a washbox, an airlifting tube extending from the washbox and including an intake end and means for introducing a primary gas to the airlifting tube, the airlifting tube passing through a central pipe, which extends from just below the washbox to a position just above the intake end. At least one screen cartridge is oriented in a generally angular downward direction in the bed and is in communication with an effluent chamber defined in part by the outer surface of the central pipe. A reject line extends from the washbox, and an effluent collector extends from the effluent chamber. A method of filtering and cleaning the filtration material is also disclosed.

Abstract: A liquid filtering apparatus is placed in a vessel having a bed of filtration material and an intake for introducing unfiltered liquid, that includes a washbox, an airlifting tube extending from the washbox and including an intake end and means for introducing a primary gas to the airlifting tube, the airlifting tube passing through a central pipe, which extends from just below the washbox to a position just above the intake end. At least one screen cartridge is oriented in a generally angular downward direction in the bed and is in communication with an effluent chamber defined in part by the outer surface of the central pipe. A reject line extends from the washbox, and an effluent collector extends from the effluent chamber. A method of filtering and cleaning the filtration material is also disclosed.

Abstract: A liquid filtering apparatus is placed in a vessel having a bed of filtration material and an intake for introducing unfiltered liquid, that includes a washbox, an airlifting tube extending from the washbox and including an intake end and means for introducing a primary gas to the airlifting tube, the airlifting tube passing through a central pipe, which extends from just below the washbox to a position just above the intake end. At least one screen cartridge is oriented in a generally angular downward direction in the bed and is in communication with an effluent chamber defined in part by the outer surface of the central pipe. A reject line extends from the washbox, and an effluent collector extends from the effluent chamber. A method of filtering and cleaning the filtration material is also disclosed.

Abstract: A liquid filtering apparatus is placed in a vessel having a bed of filtration material and an intake for introducing unfiltered liquid, that includes a washbox, an airlifting tube extending from the washbox and including an intake end and means for introducing a primary gas to the airlifting tube, the airlifting tube passing through a central pipe, which extends from just below the washbox to a position just above the intake end. At least one screen cartridge is oriented in a generally angular downward direction in the bed and is in communication with an effluent chamber defined in part by the outer surface of the central pipe. A reject line extends from the washbox, and an effluent collector extends from the effluent chamber. A method of filtering and cleaning the filtration material is also disclosed.

Abstract: An improved vertical filtration unit which includes an airlift and a washbox designed for more efficient washing of dirt particles from the filtration material. The washbox consists of a filter media shield, and a washbox skirt for washing of the filtration material. A throttling valve on the wash water discharge line regulates the overall cleaning rate of the unit. The filtered liquid is discharged via a riser pipe which feeds into a filtered liquid box before exiting the filtration unit.

Abstract: An improved vertical filtration unit which includes an airlift and a washbox designed for more efficient washing of dirt particles from the filtration material. The washbox consists of a filter media shield, and a washbox skirt for washing of the filtration material. A throttling valve on the wash water discharge line regulates the overall cleaning rate of the unit. The filtered liquid is discharged via a riser pipe which feeds into a filtered liquid box before exiting the filtration unit.

Abstract: Method of filtering liquid using a vertical filter, which includes media, an airlift, a washbox, a reject box, a filtrate chamber, and an effluent box. The method of filtration and media cleaning is automatic. The filtered liquid is collected by multi-cartridge screens before entering a filtrate chamber. The filtrate flows from the filtrate chamber into an effluent weir box. The liquid level in the filter is controlled by an effluent weir in the effluent weir box. The reject line is below the water level in the filter, which provides the driving force for the reject flow. The reject rate is controlled by liquid level in the filter tank and a throttling valve on the reject discharge line. The washbox includes a filtration material shield, a filtration material/dirtied liquid separation zone, and a washbox skirt with a washbox isolator, which prevents the dirt in the washbox form entering the influent zone.

Abstract: An improved vertical filtration unit includes a bell-shaped lower end for the air-lift tube, an injection ring for introducing air into the air-lift tube at a considerable volume, and a washbox with a more efficient scrubbing arrangement for washing dirt particles from the filtration material. The bell-shaped lower end makes the transporting of a mixture of dirty filtration material and water to the top of the filtration unit more efficient than with the conventional straight tube bottom. The tube receives compressed air from two horizontally positioned inlets positioned 180.degree. from each other. The flat and round target plate makes the scrubbing of filtration material more efficient, while a baffle prevents the filtration material from being ejected from the washbox.

Abstract: An improved vertical filtration unit includes a bell-shaped lower end for the air-lift tube, an injection ring for introducing air into the air-lift tube at a considerable volume, and a washbox with a more efficient scrubbing arrangement for washing dirt particles from the filtration material. The bell-shaped lower end makes the transporting of a mixture of dirty filtration material and water to the top of the filtration unit more efficient than with the conventional straight tube bottom. The tube receives compressed air from two horizontally positioned inlets positioned 180.degree. from each other. The flat and round target plate makes the scrubbing of filtration material more efficient, while a baffle prevents the filtration material from being ejected from the washbox.