Abstract: A fluid filter apparatus has a standard filter element in it which has the usual end gaskets seated in annular grooves. An axial drive shaft positively rotates the filter element through key-like means between the shaft and the wall of a groove. An automatic system starts and stops the rotation.

Abstract: A self-cleaning filter assembly for removing solids from an incoming liquid to be filtered. A filter element is fixed substantially coaxially within a housing and spaced from the peripheral wall thereof by an annular solids collection space in turn communicating with a solids outlet. An inlet introduces pressurized liquid to be filtered circumferentially into the solids collection space. A shower assembly rotates coaxially within the filter element and includes an eccentric portion having jets distributed along the length of the filter element and aimed outward close to the inner surface of the filter element. Backwash liquid enters the rotating shower assembly under pressure for continuously pushing solids off the outer surface of the filter element as the shower assembly circumferentially advances in the housing. Filtrate from inside the filter element passes through a filtrate outlet extending from the housing.

Abstract: A centrifugal separator has a rotary cylindrical basket on which a cake of solids builds up during rotation of the basket. The charge of the basket is controlled by a sensor sensing the thickness of the cake and a vertical manifold sprays a wash fluid on the cake. The washing of the cake is improved by mounting the manifold on a mobile support and linking this support to the sensor so that the position of the manifold is a function of the thickness of the cake.

Abstract: The magnetic filter has a magnetic cylinder (2) pivotally mounted in a housing (1) and having an inclined stripper (14). The bottom of the cylinder (2) is surrounded by a casing (5), whereby a flow channel (6) for the medium to be filtered is created between the cylinder (2) and the casing (5). One portion (5b) of the casing (5) can be mobile so that the flow-channel profile section can be changed. Decreasing the channel profile section causes an increase in the flow resistance, resulting in a backwash, so that even in cases of small quantities the level and hence the inflow characteristic of the filter is approximately the same as that of the full-load quantity.

Abstract: A backwashable filtering device is described of the type including a housing, a filter body, a backwash nozzle having a nozzle inlet disposed adjacent to the upstream surface of the filter body, and pressure sensor means for sensing the pressure drop across the filter body and effective, upon sensing a predetermined pressure drop, to initiate a backwashing operation by connecting the backwash nozzle to the atmosphere and initiating relative rotary movement between the filter body and the backwash nozzle. The filtering device further includes a position sensor for sensing the home angular position of the filter body with respect to the backwash nozzle, and a control effective, only when said home angular position is sensed, for terminating the backwash operation.

Abstract: A backwashable filtering device is described comprising a housing having a filter body and a backwash nozzle disposed therein, characterized in that the backwash nozzle is fixed with respect to the housing, the filter body is rotatably mounted with respect to the backwash nozzle, and the filtering device further includes a rotor and gear drive means rotating the filter body by the energy of the backwash fluid flowing through the nozzle.

Abstract: A rotatable self-cleaning drum shaped filter is partially submerged in a source of water and encloses the inlet of a conduit connected to a ditch pump. A part of the flow of water drawn through the conduit by the ditch pump rotates a water turbine, which turbine is mechanically connected to the drum shaped filter to rotate the drum shaped filter about its longitudinal axis. Simultaneously, a plurality of stationary nozzles forcibly spray a filtering element of the drum shaped filter as the filtering element rotates therepast to remove debris from the filtering element and prevent clogging of the drum shaped filter and water starvation at the inlet to the conduit.

Abstract: A filter apparatus has an elongated shaft, a plurality of filtering elements mounted on the shaft and spaced from one another in direction of elongation of the latter, and means for cleaning the filtering elements. The cleaning means includes a source of cleaning medium under elevated pressure and a plurality of nozzle elements communicating with this source. The nozzle elements face toward surfaces of filtering material provided on the filter elements and are turnable relative to these surfaces. The cleaning medium is ejected from the nozzle elements at a pressure between substantially 5 and 100 bar toward the surfaces of the filtering material of the filter elements so that the cleaning medium removes a cake deposited during a filtering process from the surfaces of the filtering material and thereupon also cleans the filtering material of the filter elements.

Abstract: An apparatus and method for separating entrained particulate matter from a fluid wherein particulate matter is collected in an overlying porous layer on an upstream side of a rotatable, fluid-permeable filter in a first chamber, and rotatably conveyed into a second chamber and used as an additional filtering medium. The filter comprises a cylindrical drum having a filter surface thereon and is rotatably mounted in an enclosed housing having a fluid inlet and a fluid outlet. Fluid pumping means operatively communicate with the housing for inducing a flow of fluid into the housing through the inlet and out of the housing through the outlet. Chamber means are disposed within the housing and sealingly cooperate therewith and with the cylindrical drum and define a first chamber fluidly communicating with the inlet and a predetermined portion of the cylindrical drum on the upstream and downstream sides thereof.

Abstract: A screen for a water intake has a movable filter element and a recuperation channel adjacent the filter element arranged below the lowest water level. The concavity of the recuperation channel faces the filter element. Suction is applied at the recuperation channel to cause an opposite circulation of water through the filter element at this point. The recuperation channel acts as a safeguarding device for living elements in the water and the opposite circulation of water at the channel detaches living elements from the filter element without traumatism and urges them into the channel. The channel is provided with a filter spaced from the filter element for preventing living elements being entrained by the filter element and carried to the air.

Abstract: A disc press for continuous pressing of aqueous or suspended pulp for fractionating the pulp in a liquid fraction and a dry substance fraction, comprises two plane parallel pressing discs mounted for rotation about a shaft and having strainer plates which haul the pulp therebetween by friction. The press also comprises inner and outer pressing means extending between the pressing discs and together with the latter define a curved pulp passage which in the transport direction has a varying cross section and constitutes a filling or dewatering zone, a pressing zone and a discharge zone. The passage zones of the pulp passage combined extend throughout an angle which is less than 360.degree., and the filling or dewatering zone has an approximately constant cross section. The subsequent pressing zone (B) has a uniformly decreasing cross section, the centerline of the pressing zone following an arc having an approximately constant radius about the axis of rotation.

Abstract: A cleaning method of an etched disc filter and the system therefor, in which a plurality of discs having grooved surfaces are assembled or piled one on top of another. This filter is used for removing cruds and the like in a nuclear plant. For separating cruds and the like from small flow passages provided between each two of the discs thus assembled, reverse cleaning is applied, with the discs relieved from an assembled or piled condition for providing clearances among the discs.

Abstract: A filter assembly including a housing with a plurality of individual filter units circumferentially arranged within the housing. The housing is compartmented to channel a contaminated fluid to be filtered in a filtering direction through the filter units, from one end thereof to the other. A rotatable, conduit-like backwash arm is disposed in at least one end of the housing for sealed engagement with the contaminated fluid inlet, end of a filter unit and for receiving a backwashing fluid flow therefrom. A rotatable discharge pipe connects to the outlet end of the arm and extends from the housing through a rotary-axial bearing and seal unit thereon, and is coaxially arranged with respect to the circumferential array of filter units. A rotation indexing unit adjacent the housing engages the discharge pipe for angularly shifting said backwash arm from filter unit to filter unit and thereby for backwashing of said filter units in a desired sequence.

Abstract: An in-line self-flushing filter comprises a cylindrical filter body within a housing, a rotatable member defining a purging chamber having an inlet opening close to and facing the cylindrical surface of the filter body, a purging conduit fixed to the rotary member, and a valve between the purging chamber and the purging conduit. The latter valve is normally closed but is automatically opened by a diaphram sensor sensing the difference in pressure between the filter inlet and outlet to establish communication between the purging chamber and purging conduit and thereby to effect a reverse flow of the fluid through the filter body into the purging chamber and out through the purging conduit. The outlet end of the purging conduit is eccentric to the axis of rotation of the rotatable member so as to rotate same by the reaction force of the fluid exiting from the purging conduit, and thereby to cause the inlet opening of the rotatable member to sweep along the complete cylindrical surface of the filter body.

Abstract: A self-cleanable filter, comprises: a housing having a fluid inlet, a fluid outlet, and a dirt purging opening; a filter body within the housing and having a surface facing the inlet side of the housing; and a cleaning body within the housing and movable from a home position along the cylindrical surface of the filter body for cleaning same. The cleaning body comprises a first section defining an internal chamber having an inlet opening facing the surface of the filter body to be cleaned and movable along said surface, and a second section closing the dirt purging opening when the cleaning body is in its home position. The second section has an outlet opening communicating with the internal chamber and located within the housing in the home position of the cleaning body but movable through the housing purging opening to a position externally of the housing upon the movement of the cleaning body for cleaning the filter.

Abstract: A filtration system discharging dry sludge material comprising filter aid material and contaminants removed from the liquid which have all been subjected to heat and mechanical action. These materials are conveyed from the discharge of the filtration system to a feeder for controlled introduction into the filtration system as necessary, or for disposal or reclamation.

Abstract: A biological process for removing ammonia nitrogen from waste water by forming a fluidized bed of microorganisms attached to a solid particulate carrier, continuously passing waste water to be treated through said fluidized bed, adding oxygen to said fluidized bed, retaining the waste water in the fluidized bed for a sufficient period of time while controlling other necessary parameters to biologically convert substantially all of the ammonia nitrogen to be removed from the waste water to oxidized forms of nitrogen, water and cellular material, and thence withdrawing the biologically converted products from the fluidized bed. In another form of the invention apparatus is provided for effecting the foregoing process.

Abstract: Process and apparatus for removing organic carbon from waste water to reduce biochemical oxygen demand by generating a fluidized bed formed from biota attached to a solid particulate carrier and waste water, providing enough oxygen to allow the biota to reduce the biochemical oxygen demand of the waste water passing therethrough and then mechanically removing excess bacterial growth formed on the carrier during the process.

Abstract: The invention relates to an improved cleansable filter intended for filtering natural water for the irrigation of cultivated fields. The filter comprises a cylindrical body, a filtering element mounted inside said body and defining in the interior two concentric chambers, one communicating with the exterior through a drainage valve, and also through one of two lateral openings in the body. The other annular chamber encloses the first chamber and communicates with the exterior through the other lateral opening. The filter also comprises a brush mounted coaxially in said first chamber, said brush being rotatable manually or automatically from the exterior of the filter, and removing all foreign bodies from the inner wall of said first chamber. The liquid to be filtered enters the annular chamber through a lateral opening, passes into the first cylindrical chamber and through the filtering elements from the interior to the exterior, and leaves by the second lateral opening.

Abstract: A control mechanism for apparatus for cleaning of fluid filters by a jet of fluid directed toward a filter in a direction reversed to that of the flow of fluid to be filtered through the filter element. An elongated manifold extends across the downstream or clean fluid delivery side of the filter element, and has a plurality of aligned apertures extending longitudinally of the manifold and facing the adjacent side of the filter element. A plurality of valve elements are mounted in the manifold for movement toward and away from closing relationship with the apertures, and are yieldingly urged toward closing relationship with their respective apertures. A rotary cam shaft is journaled in the manifold and includes a plurality of cams each associated with a different valve element. A pawl and ratchet arrangement is operative to open each of the valves in succession responsive to movement of the manifold across the side of the filter element.

Abstract: A rotary strainer comprising a revolving box-like structure having a horizontal axis of revolution and a filtering net stretched around the external periphery of said box-like structure, wherein a mixture of liquid and solids is introduced into said box-like structure so as to primarily separate said solids and liquid by said filtering net, with the thus separated solids being dropped with rotation of said box-like structure onto a screw conveyor extending through the inside of said structure so as to discharge the separated solids out of the structure by said conveyor, and the bottom face of a screw conveyor chute provided below the screw is slanted downwardly toward the box-like structure so that the liquid adhering to the primarily separated solids will flow back toward said box-like structure by dint of said slant for further separation.