Abstract: The invention concerns a filtration apparatus comprising a vessel divided into two chambers by a filter. An inlet orifice is provided in the vessel for liquid to be filtered, as well as an outlet orifice for the filtered liquid. A distributor device movable from the exterior of the vessel between a filtration position and a rinsing position is arranged in the vessel. In the filtration position of the distributor liquid is filtered into the first chamber, which the liquid leaves by passing through the filter, to penetrate into the second chamber, which it leaves, in the filtered condition, through the outlet orifice. In the rinsing position the liquid flows directly into the second chamber and passes through the filter in the reverse direction to penetrate into the first chamber which it leaves charged with impurities to be eliminated by an escape orifice arranged in the vessel.

Abstract: The screens of a pulp treating vessel, such as a paper pulp thickener, or diffuser, are back flushed in a simple yet effective manner. The screens are mounted to a supporting conduit within a vertical vessel, and a cylinder is connected at one open end to the conduit, and the other open end is disposed within the pulp inside the vessel. A piston is mounted within the cylinder and relative movement between the piston and cylinder is effected periodically in order to force liquid from within the cylinder into the conduit and out the screens, backflushing the screens and preventing clogging. Since no additional volume of liquid is added to the vessel during backflushing, no surge occurs in the vessel. Conventional accumulators, on/off valves, and the like can be eliminated while--in the case of diffusion washing--efficiency can be increased as much as 20-30% and capacity increased as much as about 15%.

Abstract: An apparatus and process of filtering fluids, such as white water is provided for use in the place of an existing save-all device or downstream of an existing save-all device at a paper-making mill. The white water having contaminants in a suspended state is introduced into the filtration vessel and is withdrawn from the interior of the filter element positioned within the filtration vessel. To clean the filter element from the cake which has built up on the exterior surface of the filter element, a backflushing shock is applied to the interior of the filter element, forcing all cake settled on the exterior to be dislodged, thereby cleaning the filter element. The backflushing shock is delivered from a backflushing reservoir wherein the backflushing fluid is contained under pressure at a level at least slightly above the level of a pressure differential which has built up across the filter element. The shock is applied for a period of 1-2 seconds, during which time the backflush reservoir is emptied.

Abstract: A device for mechanically purifying liquids in a pipeline includes a rotation-symmetrical sieve chamber forming a section of the pipeline and having an inlet with a central axis, a rotation-symmetrical sieve body having an inner surface and being disposed in the sieve chamber at an angle of substantially 30.degree. to 60.degree. relative to the central axis of the inlet, and a suction removal device for removing deposits from part of the inner surface of the sieve body, the suction removal device being coaxial with and upstream of the sieve body in flow direction of the liquid, and the sieve body and the suction removal device being rotatable relative to each other for successively sweeping all of the inner surface of the sieve body with the suction removal device.

Abstract: Screen cleaning showers for a sludge dewatering rotary screen thickener are kept open and effective by periodically rotating a steel wire brush positioned coaxially within the cleaning shower manifold. Shower nozzles are set into the manifold to assure full mechanical wiping of a nozzle interior surface by the axially rotating brush bristles. Brush rotation is motor driven. An automatic controller periodically and simultaneously rotates the nozzle cleaning brush and opens a normally closed solenoid valve in the shower manifold drain line.

Abstract: A fluid filtering system which includes a fluid filtering unit having a localized cleaning arrangement. The fluid filtering unit comprises a filter element through which the fluid being filtered is passed and structure for cleaning the filter element without interruption of the filtering operation of the unit. The cleaning structure includes a cleaning head which ejects fluid under pressure and which is moveable relative to the filter element to bring about localized cleaning of the element. Preferably, the filter element is moved, by an hydraulic arrangement to bring about localized cleaning over the whole of the filter element.

Abstract: An apparatus and method for filtering a fluid by directing a flow of the fluid against a filter such that only a portion of the fluid passes through the filter and the remainder passes over the filter to clean it thereby preventing the filter from becoming clogged. The apparatus can be used in a rotary fluid management device of a dynamic isotope power system for filtering fluid therein which is to be used for lubricating bearings of the device for a period of many years with no maintenance.

Abstract: The invention relates to a method of and an apparatus for filtering a medium. The apparatus has a filter housing and a supporting means located within the filter housing. A plurality of fiber bundles are attached to the supporting means and extend within the filter housing in direction between an inlet and an outlet. A flexible waterproof membrane is provided within the filter housing to constitute a pressure chamber. When pressurized during the filtration process, the membrane presses the plurality of fiber bundles to form a frustrum-like filter chamber. The medium becomes filtered as it passes through the frustum-like filter chamber.

Abstract: A clothes washing machine of the vertical axis type has a self-cleaning lint filter integral with the spin tub. The spin tub is formed as a unitary piece from plastic material, and includes a central hub and radially outer bottom wall which are interconnected by a plurality of radially extending ribs. The ribs have spaces between them defining an annular gap, and an annular perforated lint filter is secured in the gap. An oscillating agitator within the spin tub has downwardly projecting vanes on the lower outer surface of its skirt portion which, as the agitator oscillates, cooperate with the spin tub ribs to form a pumping action to pump liquid upwardly through the lint filter and out to the interior of the spin tub. When the agitator and spin tub go into a spin mode, the centrifugal force washes the lint on the underside of the lint filter off into the fluid being pumped to drain.

Abstract: An apparatus for removing solid particles from cooling water having a tubular housing (1), a funnel-shaped trap sieve (4) attached to the inner housing wall with the tip facing in the flow direction, and a pressurized water sprayer (11). The sprayer includes a washer arm (14), concentrally rotatable about the downstream side (23) of trap sieve (4), and having at least one slit nozzle (15) directed toward the downstream surface (23). A suction tube (8) extends into a collecting chamber (10) of trap sieve (4). To prevent large particles from jamming rotating components, trap sieve (4) is cleaned by spraying water only against the downstream side. The tip of the sieve is defined by a cylindrical container (5) having a closed bottom (6). The intake end (9) of suction tube (8) extends into the container. Wash water is introduced into washer arm (14) through an inner end fixedly attached to a hollow flange (13) mounted on a rotary shaft (12) of pressurized spray apparatus (11).

Abstract: A soil removal apparatus for a dishwashing machine including a stilling zone located in the sump of the dishwasher, and a receptacle located below the stilling zone for collecting and storing soil particles. The receptacle is also provided with a check valve and a second inlet as well as an outlet so that, upon operation of the dishwasher in the drain mode, drain water is routed through the receptacle for flushing soil particles from the receptacle to the outlet of the receptacle. During the draining operation, a check valve closes the first inlet of the receptacle.

Abstract: A slurry of comminuted cellulosic fibrous material (e.g. paper pulp) is acted upon so that particles contained in the slurry are separated out from the slurry and introduced into a second liquid flow, while maintained under superatmospheric pressure. A partition divides a liquid tight pressure resistant vessel into first and second distinct chambers isolated from each other except by a slit at a mid-portion. An inlet for the slurry and an outlet for the first liquid are connected to the first chamber, and an inlet for the second liquid and an outlet for the second slurry to the second chamber. A screening disk is mounted for rotation in the vessel so that it fills the slit, with portions disposed in both the first and second chambers.

Abstract: A method and an apparatus for removing filterable particles from water are disclosed. One or more filter bags made from a filter material suitable for filtering off the particles to be separated are disposed in a body of water with the bottom of the bag situated below the water surface and its opening situated above the surface. The water flows through the wall of the filter bag to the surrounding body of water, while the particles remain within the bag. After a certain amount of particles has been collected in the filter bag, backwashing is carried out and the particles removed and conducted to a place remote from the body of water. The method and apparatus are particularly suitable for restoration of lakes, rivers, water courses and similar water bodies.

Abstract: A pressure diffuser for paper pulp includes a vertical pressurizable liquid-tight vessel having a pulp inlet at the bottom and a pulp outlet at the top. One or more ring shaped screen elements providing first and second concentric screen surfaces, are vertically mounted within the vessel. A number of radially extending header arms mount the screen elements for movement in the vessel and in fluid communication with it. A first linear actuator effects reciprocation of the arms. A cylinder, open at both ends, is affixed to the arms and extends both above and below them, and a piston is disposed within the cylinder, below the arms. A second linear actuator is operatively connected to the piston to effect reciprocation of the piston in the cylinder. A guiding conduit surrounds the open end of the cylinder above the arms and guides reciprocation of the cylinder and transports liquid from the arms to an effluent outlet.

Abstract: A filter apparatus for removing plankton out of fresh or sea water containing the plankton. The filter apparatus comprises a filter housing provided with a partition plate having a plurality of through-holes thereby to partition the housing into a non-filtrate chamber and a filtrate chamber. A plurality of filter elements, each having open top end, a filter portion and non-filter portion, which are fitted in the through-holes of the partition plate to protrude the open top ends into the filtrate chamber. Plankton in the water are concentrated at the non-filter portion disposed near the partition plate and removed through an opening provided at a portion of the non-filtrate chamber near the partition plate.

Abstract: A backwash strainer having a generally cylindrical filter element made up of a stack of spaced rings that are triangular in cross section, with the bases of said triangular rings disposed in a cylindrical surface. A hollow backwash arm has an open slot disposed on the inside of the cylindrical surface which operates at a predetermined distance from said element. The incoming water in said strainer flows from the inlet up through the straining element to the outlet. The backwash arm receives water from around the straining element, which flows through the element into the backwash slot and out with the debris accumulated on said strainer. Since the debris is supported on the flat interior of the rings, water flowing back into the arm into the slot in the hollow backwash arm forces trash and other debris from the rings down to the backwash water outlet. Water flowing through the clearance between the bars as used, helps flush the debris off the inside of the filter element.

Abstract: A liquid filtering and backwashing apparatus comprising a filter tank having a first outlet valve and a filter cell disposed within the filter tank is disclosed. The filter cell includes a conduit and an outer member with the outer member spaced apart relative the conduit with a filtering medium positioned between the conduit and the outer member. A plurality of openings in the outer member enable fluid communication between the liquid to be filtered in the filter tank and the filtering medium. The conduit is provided with a plurality of slits to enable fluid communication between the filtering medium and interior of the conduit while retaining the filtering medium external the conduit. A backwash holding tank in fluid communication with the conduit collects the filtered liquid. The backwash holding tank includes a second outlet valve for the filtered liquid to drain.

Abstract: A method of treating a heated liquid suspension, which entails:(a) applying a liquid suspension to elastic, microporous, hollow fibres within a shell or housing, and(b) discharging solids retained on or in the fibres by applying to the fibre lumens a pressurized reverse flow of gas, and wherein the hollow fibres are cooled prior to applying the reverse flow of gas.

Abstract: An improved self-cleaning fluid filter (10) having a housing (12) with spaced inlet and outlet ports (14, 16) formed in a common wall (18) of the housing (12). The filter (10) further includes a first sleeve (48) extending from the housing's common wall (18) in which the outlet port (16) is formed. An interior chamber within the first sleeve (48) communicates with the outlet port (16), and the first sleeve (48) has a narrowed portion (52) proximate the outlet port (16). The narrowed portion (52) of the first sleeve (48) has at least one orifice (102) formed therein. The filter (10) further includes a second sleeve (60) extending from the common wall (18) and generally concentrically encircling an axial portion of the narrowed portion (52) of the first sleeve (48). A generally annular space (72) is, thereby, defined between the first and second sleeves (48, 60).

Abstract: The screens of a pulp treating vessel, such as a paper pulp thickener, or diffuser, are back flushed in a simple yet effective manner. The screens are mounted to a supporting conduit within a vertical vessel, and a cylinder is connected at one open end to the conduit, and the other open end is disposed within the pulp inside the vessel. A piston is mounted within the cylinder and relative movement between the piston and cylinder is effected periodically in order to force liquid from within the cylinder into the conduit and out the screens, backflushing the screens and preventing clogging. Since no additional volume of liquid is added to the vessel during backflushing, no surge occurs in the vessel. Conventional accumulators, on/off valves, and the like can be eliminated while--in the case of diffusion washing--efficiency can be increased as much as 20-30%, and capacity increased as much as about 15%.

Abstract: A filter (51) for liquids comprises a filter vat (52) having an inlet orifice (60) for the liquid to be filtered, an outlet orifice (58) for the filtrate, and an evacuation orifice (66) for solid particles, together with filter elements comprising filter medium cloths disposed vertically around filter leaves (18) inside said vat between said inlet and outlet orifices. Said cloths (12) are in the shape of elongate pockets (16) threaded freely over said leaves (18), said leaves being provided with longitudinal drainage channels (32), said pockets having openings (19) in communication with said outlet orifice (58), and said filter leaves (18) being suspended beneath supports (20) which are fixed inside said vat (52), with said leaves being free to rock sideways from their supports.

Abstract: A filtering method and apparatus including a chamber having an inlet and an outlet and a mass of fibers interposed between the inlet and outlet and contained between a perforated base and piston. Structure is provided for reciprocating the piston relative to the base during backwash operation.

Abstract: In a slurry dewatering process, slurry is pumped into a porous tube at a sufficiently low velocity for laminar flow conditions to exist. The pressure is sufficiently high for liquid in the slurry to permeate outwardly through the tube wall and for solids in the slurry to be deposited in the form of an annular cake on the tube wall. The deposition of solids is controlled so that the cake thickness is substantially uniform throughout. When a predetermined thickness of cake has been deposited, the pressure inside the tube is decreased and the flow velocity is increased and the cake is dislodged from the tube wall in flake form and is conveyed downstream for collection on a screen or the like.

Abstract: A fluid filtering device, comprises: a housing having a fluid inlet and a fluid outlet for the fluid to be filtered, and a flushing outlet for the dirt separated from the fluid; a supporting core extending longitudinally within the housing; a plurality of annular filter discs supported as a stack on the supporting core; and a pressure plate supported at one end of the stack, and movable in one longitudinal direction to tighten the stack by pressing the discs together, or in the opposite direction to loosen the stack. A cleaning nozzle is supported within the housing for movement along the length of the stack and has its axis oriented to apply a flushing fluid eccentrically to the discs, when the stack is loosened, to rotate the disc on the supporting core and thereby to flush the dirt particles therefrom through the flushing outlet.

Abstract: The invention relates to an improved process and apparatus to produce a filter cake formed by retained solids collected on a filter cloth during filtering. Accordingly, the filter cake is sub-divided into a plurality of filter cake elements which are kept separate from each other at predetermined distances. Further, impermeable zones on the filter cloth are formed around the filter cake elements. The filter cake elements and the impermeable zones are of a size that the filter cake elements can freely contract in any plane without cracking, while the filter cloth between the filter cake elements is covered by the impermeable zones.

Abstract: Water straining device for removing sand, grit and other foreign suspended particles from water characterized by a cylindrical housing having a bottom closed end and an open top end together with multiple annular holes through the cylindrical side wall. Cylindrical baffles are mounted inside the housing adjacent each hole. At least one strainer containing multiple slots is located inboard of the baffles and is connected at one end to a pump with a one way valve interposed between the strainer and pump. A backwash system is connected to the inside of the housing to remove particles clogging the strainer slots.

Abstract: The present invention provides an apparatus and method for the separation of solids entrained in fluid streams. The apparatus consists of a pipecross-like chamber which is divided into two regions by a perforated deflector/separator plate angularly disposed within the chamber. A shear jet is disposed perpendicular to the flow path and higher pressure fluid is thereby injected into the chamber to deflect and separate entrained solids. In preferred embodiments the apparatus and method are used to protect a centrifugal pump impeller from damage by the solids. While conventional pipe joints and parts can be used, an alternate embodiment provides removable side plates and a removable deflector/separator plate for ease of installation and maintenance.

Abstract: A filter for hot melt adhesive is carried within a passageway in a manifold and is rotatable therein between a filtering position in which hot melt adhesive is directed to the inner core of the filter at one end thereof, and a backflushing position in which hot melt adhesive is directed onto the outside surface of the filter at the opposite end thereof. In the filtering position, the hot melt adhesive flows from the inner core outwardly through a filter screen into the main passageway for collection and discharge from one end of the manifold. In the backflushing position the adhesive flow is directed from the outside surface of the filter in the reverse direction through the filter screen to dislodge filtered impurities therefrom, and then the impurities are carried out a drain at the opposite end of the manifold.

Abstract: A magnetic filter comprises a vessel, a screen main body disposed within the vessel for partitioning the vessel into an upper chamber and a lower chamber, a filtration layer formed by particle-like filter elements magnetized by magnets and disposed on the screen main body. Corrosion products entrained in a liquid charged into the upper chamber are removed by the filtration layer.

Abstract: A filter device is disclosed, comprising two compartments within a housing. The first compartment includes a filter element, of the screen or the disc types, with communication to the filtered fluid outlet of the housing. A controllable valve communicates the first compartment with the inlet of the housing across the second compartment. A drain valve connects the first compartment with outside the housing. For flushing the filter element by reverse-flow, the first valve is closed and the flushing fluid drains through the drain valve. In a further embodiment two or more filter elements and associated compartments and valves are installed, in parallel, within the same housing, so that by stopping the filtering operation of one of the filter elements, it becomes flushed with the product, filtered fluid of the other element.

Abstract: A disk filter of the counter-current flow cleaning type, containing superposed ring-shaped elements (12) form a body (9) of a generally cylindrical shape. The elements are arcuate so as to form between them passages which are arcuate and oblique in relation to the axis of the filter when viewed in a cross section taken along the axis of the filter. Stopping means (19, 20) are provided on the filter elements (12) which abut against the adjacent filter element (12) during the filtering to prevent the filter elements (12) from vibrating, while allowing their vibration to occur when the filter is cleaned by a counter-current flow of liquid.

Abstract: A method and apparatus are disclosed for automatically cleaning extrusion screens in finishing machines of a type having a generally cylindrical perforated screen arranged in a housing, juice or the like laden with solids being introduced into the interior of the screen and urged against the screen by a screw element, paddle assembly, or the like to cause the juice to flow through the screen with the solids being retained on the screen. The cleaning method and apparatus comprise a cleaning unit with a plurality of spray nozzles arranged about the screen, the cleaning unit being moved back and forth along the screen by a reversing motor additionally controlled by suitable limit switches. The method and apparatus of the invention are preferably adapted for causing relatively increased cleaning action adjacent a solids outlet end of the screen to better remove larger amounts of juice solids or pomace deposited on that portion of the screen.

Abstract: The present invention provides a rotary drum filter wherein one or preferably two rotary drum filters are submerged in a tank of liquid to be filtered. Each rotary drum filter is comprised of a generally cylindrical tank having a perforated outer wall plate over which is applied a cloth type filter media. A suction pipe is included inside the rotary drum filter so that filtered liquid can be drawn into the rotary drum filter through the pressure differential established by the suction pipe. Clean filtered liquid exits the suction pipe to the industrial apparatus with which the filter apparatus is used. A backwash vacuum box extending generally the length of the rotary drum filter media is in contact with a portion of the rotary drum filter media. A partial vacuum is established in the vacuum box such that filtered liquid can be drawn outwardly from the rotary drum filter such that solids accumulated on the filter media are drawn off from the filter media thereby cleaning that section of the filter media.

Abstract: In a system for separating solids from a liquid in a slurry, a filter apparatus is cleaned by a jet and a removal device. The filter is generally flat and has an inflow side on which the solids are deposited and an outflow side supported by a grid. The grid subdivides the outflow side into a plurality of separate injection chambers and defines a plurality of separate small regions of the filter. The jet directs a stream of liquid through one of the injection chambers and against one of the small regions of the filter defined by the injection chamber. A cover plate is provided on the jet for engaging the grid to close one injection chamber opposite the filter. The removal device is located on the inflow side of the filter and is aligned with the jet to receive solids dislodged from the filter. The jet and removal device move simultaneously and in alignment to close selectively and to direct a stream of liquid through each of the injection chambers.

Abstract: In connection with a surface material cleaning apparatus, a tank of cleaning fluid, an outlet line from the tank to a cleaning head, a suction pump carried by the tank recovering cleaning fluid from the cleaning head, a pump feeding the outlet line from the tank, a bleed line from the pump passing liquid into and through the filter under a relatively high pressure creating a motion of liquid through and about the wall of the filter maintaining the filter wall in a relatively unclogged condition, the cleaning fluid in the tank being recycled for cleaning purposes through the filter at a relatively low pressure.

Abstract: A method and apparatus for cleaning cooling tower basins. The apparatus includes a reservoir and large pipe extending from the tower basin to a lower level to act as a siphon. A water supply can fill the large pipe, and a valve can be opened to start the siphon. A cleaning tool remains below the water level in the basin to maintain the siphon while the basin is cleaned. The makeup water valve maintains the desired water level in the basin, so the tower can remain in operation during cleaning. The material removed from the basin is strained and the waste water is disposed of through conventional sewerage.

Abstract: A filter unit includes:(a) structure providing a porous barrier between a first zone from which liquid to be filtered is supplied, and a second zone to which filtered liquid flows, via the barrier,(b) the barrier including a series of elements defining grooves, and filtering media between those elements and communicating with the grooves,(c) certain of the grooves presented for reception of liquid flow therein from the first zone so that liquid flows from the certain grooves through the media,(d) others of the grooves presented for reception of flow from the media and for subsequent flow via the other grooves to the second zone,(e) control means for providing backflushing only as required as an alternative to periodic backflushing.

Abstract: A dairy waste separator provided with a separation screen and longitudinally oscillating water pipes as the cleaner.

Abstract: A multiple-disc filter comprises a stack of filtering discs each formed with grooves extending only partially through the thickness of the disc and configured to define a continuous, non-apertured surface on one face and a plurality of spaced ribs projecting from the opposite faces. The ribs are connected together to define a sinuous configuration and have flat line edges. The stack further includes spacing means between the contacting faces of adjacent discs of the stack, spacing the straight line edges of the sinuous ribs of one disc from the face of the next adjacent disc in the stack, such that the contacting faces of adjacent discs define a first group of recesses between the ribs communicating with the housing inlet, a second group of recesses alternating with the first group of recesses and communicating with the housing outlet, and a plurality of filtering passageways between the straight line edges of the ribs and the opposite face of the next adjacent disc.

Abstract: A process and apparatus for the regeneration in operation of lubricating oils having a first stage in which a flow of oil passes through a filtering surface, then a second and third stage in which a portion of the flow of oil is intercepted and sent countercurrently under a pre-established overpressure to the first stage flow and finally, a fourth stage for varying the position of delivery countercurrent to the filtering surface.

Abstract: A filter assembly especially suitable for filtering swimming pool water includes an upright tank, and a flexible, cylindrical porous filter bag supported on star shaped core elements which are vertically spaced along a perforated outlet tube fixed centrally within the tank. Water normally flows through a filter media such as diatomaceous earth caked on the outside of the bag into the central tube and out of the tank back to the pool. When the bag becomes clogged by dirt trapped on the outer face of the filter cake, water flow is reversed for a short period of time to expand the bag suddenly and thereby release the dirt. The bag and filter media are regenerated periodically in this fashion to prolong the effective performance life of the filter.

Abstract: A self-cleaning canister type filter (1). A cylindrical canister enclosure (3) has, at one end, end plate (2) with fluid inlets (4) and outlet (6) therein. A spring-loaded hollow annular piston (30) is slideably mounted on the exterior of central tubular cylinder (10) and within upper cylinder (28) for a downward movement against compression spring (32) to initially force a back-flow of filtered fluid through filter element (14), lifting contaminant particulate solids from its filtering surface (15). Inlet valve opening (64) is opened to fluid flow when piston (30) attains a compressed position. Filter element (14) is closely spaced to canister enclosure inner wall surface (9) for rapid flow of fluid over the inlet surface (15) of the filter element (14) to scour solids to sump (5) in the lower portion of the canister enclosure (3).

Abstract: There is provided a fluid filter system cleanable by suction. The system comprises a filter element fixedly attached to a substantially rigid filter-element support mounted in a filter housing and provided with a plurality of openings, at least one suction nozzle having an inlet opening located in close proximity to the filter element and adapted to move with its inlet opening past the filter element in such a way as to cover, in succession, at least some zones of the filter element while producing a suction flow. The invention further comprises guide means for guiding a fluid stream from the high-pressure raw-fluid space of the filter housing to a low-pressure zone created by the suction nozzle between the inlet opening thereof and that portion of the filter-element support which faces the suction nozzle.

Abstract: A multi-element filter unit includes backwash apparatus and comprises a filter casing with provision for alternative, oppositely directed process liquid and backwash liquid flows therethrough. A plurality of filter tubes are close spaced within the filter casing. A flange engages the filter tubes and divides the filter casing into first and second chambers. Apparatus for sequentially backwashing the filter tubes during a backwash interval removes collected solids from between the filter tubes by flow of backwash liquid from one filter tube outward toward the exterior of adjacent filter tubes.

Abstract: In order to clean a screen in a waste water purification plant a surge of a body of water is generated by the agency of a dump flushing apparatus, which surge drops in a free fall towards the screen to be cleaned. This surge of cleaning water is given a dimensional extent which ensures for a substantially simultaneous impinging of the body of water onto the total extent of the screen. A framing which surrounds the screen encompasses this surge of water such as to guide the water and to force the water to flow through the screen. During the cleaning or flushing action the contaminants adhering to the screen, which contaminants are substantially of a thixotropic nature, will be removed from the screen and flushed through a sump towards the water purification section of the water purification plant.

Abstract: A filter capable of being cleaned by reverse flushing, comprises a housing including a fluid inlet, a fluid outlet, a flushing outlet, and a filter body disposed within the housing. The housing includes blocking members disposed on opposite faces of the filter body and axially spaced from each other to define a reverse flushing passageway from the fluid inlet to the flushing outlet through the portion of the filter body between the axially-spaced blocking members. At least one of the blocking members is movable axially of the filter body to reversely-flush the complete length of the filter body.

Abstract: A cylindrical insert for a pre-existing pressure vessel has an integral accumulator chamber defining a head for the vessel. Inner end surfaces of the accumulator chamber, along with the walls of the pressure vessel, define a filter element chamber, the inner end of the accumulator chamber also supporting an array of permanent filter elements. The accumulator chamber is of annular form, around a central pipe which serves, alternately, as the outlet for filtered fluid passing from the filter chamber or as the inlet for filtered clean fluid to be forcefully pulsed back through the filter elements by the release of compressed air from the accumulator to flush them of an accumulation of filtered waste material. The insert system includes piping associated with the accumulator chamber for charging the chamber with highly compressed air and for selectively releasing the charge for backflushing, and control valves for placing the insert system in filtering and backflushing modes.

Abstract: A drum filter is disclosed mounted vertically within a tank which receives the liquid to be filtered. The drum is provided with inside and outside filter media layers and intermediate axially extending passages receiving filtered liquid flow, which is collected in a central tube extending vertically upward and adapted to be connected to a suction pump.A backwash arrangement includes a backwash flow passage directing flow successively through each of the axial passages as the drum is incrementally rotated about its axis.Collection troughs are positioned extending axially along the inside and outside periphery of the drum member so as to receive the backwashing flow and contaminants, with a flushing flow carrying off the contaminants from the tank for secondary filtration.The rotary indexing drive consists of a cylinder actuated ratchet drive with a sprocket wheel in engagement with a chain track located about the interior diameter of the drum member at its upper end.

Abstract: A plurality of filter housing are arranged around a hollow hub section the interior of which is divided into an inlet chamber for receiving fluid under pressure to be filtered, an outlet chamber for receiving filtered fluid, and a backwash chamber that is connected to a waste line. Each filter housing contains an inverted, frustoconically shaped filter element having a closed lower end, and an open upper end connected to the outlet chamber of the hub section. Fluid that is to be filtered normally flows from the inlet chamber through a first series of valves to the lower ends of the filter housings, and then radially inwardly through the walls of the filter elements and out of the upper ends thereof and through a second series of valves to the outlet chamber.

Abstract: This disclosure is directed to a wastewater treatment plant which includes pretreatment, aeration, final clarification and overflow/backwash chambers adapted to receive a fluid, such as home wastewater, which is to be subjected to extended aeration or aerobic digestion, the aeration chamber including an aerator having a shaft whose lower end is normally received in the fluid which is to be treated, an aerator foam deflector carried by the shaft which under abnormally high fluid levels increases the torque on the shaft and, thus, indicates abnormal operation, the final clarification chamber including a demand use filter, an overflow outlet operative should the filter become disabled, and a backwash nozzle located in the filter by reverse pumping therethrough fluid pumped from the overflow or backwash chamber.