Abstract: A method for filtering liquids, especially drinks, is by a filtering device having at least two filter lines. Each filter line has at least one filter unit with at least one preliminary filter and one terminal filter which can be connected to or disconnected from the respective filter line independently of each other and which can also be independently regenerated. The pressure differential of at least one filter unit on each filter line is measured. Once a predefinable threshold value is reached for the pressure differential, the volume flow entering the device is reduced. The associated filter unit is disconnected from the filter line. The reduced volume flow to be filtered is handled by the corresponding filter unit in the other filter line which is fluidically connected to the filter line between the respective preliminary filter and the respective terminal filter. The disconnected filter unit is regenerated.

Abstract: A coal bed methane wastewater treatment system for efficiently and cost effectively treating wastewater generated from coal bed methane production. The coal bed methane wastewater treatment system includes collecting wastewater into an ozone diffusion tank where ozone is injected into the wastewater, passing the wastewater through a prefilter tank and then through a primary membrane. The treated water is separated to a permeate tank and the concentrated water is passed through a secondary membrane for further separation. The concentrated water is then placed within a holding pond for evaporation thereof. The treated water may be utilized to clean the prefilter tank and the membranes. The treated water is then dispensed into a sodium adsorption ratio tank prior to being released to a natural waterway.

Abstract: Modules of ultrafiltration or microfiltration membranes are arranged in a tank open to the atmosphere to substantially cover the cross sectional area of the tank. A filtration cycle has permeation steps and deconcentration steps. During permeation, supply of feed substantially equals feed removed and little if any aeration is used During deconcentration, aeration with scouring bubbles is provided with one or both of backwashing and feed flushing. In feed flushing, feed water is supplied to the tank from below the modules. Excess tank water created during deconcentration flows generally upwards through the modules and out through a retentate outlet or overflow at the top of the tank.

Abstract: A laminated modular water filter includes superposed annular plates. A filter unit is disposed between each adjacent pair of the annular plates. The annular plates include a top plate, a bottom plate, a plurality of intermediate plates, and at least one flow-guiding plate sandwiched between two of the intermediate plates. Each of the top plate, the intermediate plates, and the bottom plate has an annular outer passage unit in fluid communication with a curved outer passage unit in the flow-guiding plate. Dirty water is introduced into two side openings in the top plate, and flows into central holes in the annular plates via the filter units so as to form filtered water. Solid particles in the dirty water are guided into two side openings in the bottom plate via the annular outer passage units and the curved outer passage unit.

Abstract: Parallel desalting (PDS) includes a hybrid membrane softening (MS) system for de-mineralizing water for residential and commercial use. Parallel desalting produces “soft” water without the use of salt, or any other liquid chemical reagent normally used to carry out pH adjustment in industrial membrane and precipitation processes. The PDS process balances the operation of a RO (potable water) membrane unit with the operation of a tubular MF (wastewater) membrane unit, thereby providing a highly efficient and regenerative water treatment technology: (1) The optimum operation for the PDS system transforms roughly 90 percent of a potable, slightly brackish water supply into <50 mg/L TDS water with <1 -grain (10-15 mg/L as calcium carbonates) water hardness; and (2) The operation of the PDS system produces, in salinity terms, in a 100 percent reusable effluent for downstream recycling.

Abstract: A spiral wound membrane module comprises a spiral wound membrane element including a separation membrane having high back pressure strength. The flow rate of permeate in filtration of the spiral wound membrane element is preferably set to 0.5 to 2.0 m3/m2/day, and the filtration time is preferably set to 10 to 300 minutes. The flow rate of wash water in washing is preferably set to 1.0 to 4.0 m3/m2/day, and the washing time is preferably set to 10 to 300 seconds. In such ranges, the ratio of the permeate volume in filtration to the permeate volume in back wash reverse filtration is set to be not more than 600.

Abstract: The present invention relates to stationary cloth media filtration systems and devices, as well as processes and devices for uniform flow distribution and improved cloth media filter backwashing.

Abstract: A method and apparatus for cleaning a membrane module, the membrane module having a plurality of porous membranes, the membranes being arranged in close proximity to one another and mounted to prevent excessive movement therebetween and means for providing, from within the module, by means other than gas passing through the pores of the membranes, gas bubbles entrained in a liquid flow such that, in use, the liquid and bubbles entrained therein move past the surfaces of the membranes to dislodge fouling materials therefrom, the gas bubbles being entrained in the liquid by flowing the liquid past a source of gas to draw the gas into the liquid flow. The gas bubbles are preferably entrained into the liquid using a venturi type device. The membranes are preferably partitioned into discrete groups to assist cleaning while maintaining high packing density.

Abstract: A method and apparatus of purifying feedwater to remove impurities including suspended solids therefrom, the method suitable for using in-line water pressure to permeate water through hollow fiber membranes and to backflush the membranes to remove solids collected or deposited thereon.

Abstract: An apparatus for filtering suspended solids from a liquid having a group of filters mounted inside a filter chamber. The filters divide the chamber into dirty liquid chambers and clean liquid chambers. A wash assembly is disposed within the chamber having vacuum/pump heads in contact with the filters rotates within the chamber. The vacuum/pump heads are connected to a pump and vacuum source located either within or without the apparatus. The vacuum/pump heads either vacuum material up or spray material therefrom in order to clean the filters. As the wash assembly rotates, the vacuum heads are able to contact and clean the entire surface of the filters.

Abstract: A system and method for enhancing the flux and separation properties of water filtration membranes by oxidizing raw or processed water constituents with direct photolysis of the water matrix by pulsed blackbody UV, yielding ozone and hydrogen peroxide, hydroxyl radicals and other short lived oxidizing species. The result thereof, causing precipitation of inorganic molecules or organically complexed minerals, partial or complete mineralization of organic molecules and the deactivation or destruction of microbes including: virus, bacteria and protozoa. The system and method comprises a pulsed blackbody, deep-UV reactor having at least one treatment chamber, the reactor having a conveying assembly to convey the water to be treated into the chamber; a filter assembly to screen the UV treated water; a caustic supply means for the post-treatment of water; a recovering assembly recovering the permeate at an outlet of the filtration means. The effect of such UV water treatment is multifaceted.

Abstract: The present invention relates to stationary cloth media filtration systems and devices, as well as processes and devices for uniform flow distribution and improved cloth media filter backwashing.

Abstract: A filter is provided within a case. A to-be-filtered fluid flowing into the case is passed through a peripheral wall of the filter. Thereby, foreign matter included in the to-be-filtered fluid is captured by filtration. A cleaning member is provided within the case. The cleaning member pressurizes the to-be-filtered fluid by a pressure fluid, and causes the pressurized to-be-filtered fluid to pass through the peripheral wall of the filter in a direction reverse to a direction in which the to-be-filtered fluid is filtered. When foreign matter captured in the filter is to be removed and cleaned, the to-be-filtered fluid remaining in the case is pressurized by the cleaning member and caused to flow in a direction reverse to a direction in which the to-be-filtered fluid is filtered. Thereby, foreign matter captured by the peripheral wall of the filter is removed.

Abstract: A coupling device for connecting a filter element to a fluid conduit has a male coupling secured to either the fluid conduit or the filter element. The male coupling also has at least two radially projecting tabs. A polymeric female coupling engages with the male coupling for securing the filter element on the fluid conduit. The female coupling also has lands for receiving the tabs. The male and female couplings each have a passageway for fluid and that generally defines an axial direction. Each tab is configured for distributing an axial force generally throughout the tab and laterally relative the axial direction so that either the land being forced against the tab or the tab being forced against the land does not damage the female coupling and as long as the filter element remains secured to the fluid conduit.

Abstract: A filtering system (10) is provided for filtering working fluid from a machine (12) and includes a cleanable filter (16) and a centrifuge (82) where filter capacity is too low for a permanent filter yet flow rate is too high for a centrifuge. The system transfers the contaminant storage function from the cleanable filter to the centrifuge. A simple effective centrifuge is provided.

Abstract: A method and device for dewatering most liquid/solid solutions and slurries is described. A dewatering device having a dewatering pump in fluid communication with a filter rack with vertically arrayed filter elements that is carried by a container. To begin the dewatering process, the filter rack is lowered to the bottom of the container and the liquid/solid slurry is introduced. Next, the dewatering pump draws the liquid from the slurry into the filter rack and then to the pump. When dewatering efficiency decreases, the dewatering operation is momentarily stopped and the filter elements of the filter rack are backpulsed with air and raised to dislodge the filter cakes that have formed. The filter rack is then relowered and the dewatering operation continues. These steps of dewatering, backpulsing, raising the filter rack, and lowering filter rack are continued until the container is full of dewatered solids.

Abstract: A filtering apparatus and method comprises parallel filtering elements backflushable with the pressure of the filtered flow. At least one washing organ connecting alternately to the different filtering elements, forms a discharge channel for the washing flow. A freewheel clutch is connected to a rotating axle of the washing organ, converting reciprocating movement generated with the pressure of flow in the filtering apparatus and with pressure alternating with it into a continuously parallel, stepping rotary movement of the washing organ. The mechanism containing the clutch may be outside the filtering room of the apparatus, and based on the alternation of the higher pressure of the flow filtered in the apparatus and the lower pressure from the discharge channel. The freewheel clutch is articulated to a piston in the cylinder, and is moved back and forth with the pressure difference, controlled by the channels relaying the pressure and by the valves.

Abstract: An apparatus is described for withdrawing filtered permeate from a substrate contained in a reservoir at ambient pressure. The apparatus includes a plurality of membrane assemblies. Each assembly has a plurality of hollow fiber filtering membranes, immersed in the reservoir, at least one permeating header with the membranes sealingly secured therein, and a permeate collector to collect the permeate sealingly connected to the at least one permeating header and in fluid communication with lumens of the membranes. The membranes of each assembly extend generally vertically upwards from a first header during permeation. One or more sources of suction are provided in fluid communication with the lumens of the membranes of each assembly through the permeate collectors and apply sufficient suction to withdraw permeate from the lumens of the membranes. An aeration system for discharging bubbles assists in keeping the membranes clean.

Abstract: A self-cleaning water filter, coupled to a water flow having particulates therein, that includes a pair of canisters, each having a cylindrical wedge wire water filter screen. An elongated brush running the length of the screen is disposed between two confining walls also running the length of the screen to form a chamber. A elongated partition, including two sets of apertures, is used, along with the elongated brush, to divide the chamber into two particulate dislodge chambers and a drain subchamber. A drain is in fluid communication with the drain subchamber. During cleaning, the drain is opened and the screen is rotated against the brush for liberating the particulate contaminants and a limited amount of the water flow into the two dislodge subchambers. The particulate contaminants and the limited amount of water then pass through the apertures at a high velocity and into the drain a subchamber which exits through the drain.

Abstract: The present invention encompasses a process for producing synthetic hydrocarbon products in a reactor. The focus of the present invention is on a novel filtering system for separating synthetic hydrocarbon products from catalyst within the reactor. The filtering system of the present invention could also be used for a variety of similar processes where it is desirable to separate a solid from a liquid within the solid/liquid mixture. Finally, the present invention discloses a novel filter and a method for making the filter.

Abstract: A filter element with a cylindrical structure having a filter medium 11 mounted to a support element 10. The filter medium 11 is fastened to the support element 10 in such a way that no relative movement between these components is possible. This creates a heavy-duty assembly between filter medium and support element and increases filter life. It is thus possible for the filter to withstand a pulsating load, e.g., caused by backwashing of the filter medium, without risk of destroying the sensitive filter medium due to vibrations or any relative movement between the support element and the filter medium. This assembly may be produced by mounting the filter medium under tension to the support element and by fixing it with a reinforcement strip 12. The use of valves with switching times of less than 0.4 seconds makes it possible to achieve extremely short backwash pulses to clean the filter without risk of failure of the filter medium.

Abstract: In an apparatus containing rotating filter media that removes solids from a fluid stream, the invention provides devices and methods for improved cleaning of the filter media. Solids trapped on the filter media are removed by the application of a pressurized fluid spray system. The spray system has nozzles distributed across a spray arm. The nozzles create a generally elliptical spray fan pattern in contact with the filter media. The nozzles are spaced and angularly oriented on the spray arm so that adjacent spray fan contact areas overlap. This distribution and orientation equalizes the distribution of the washing flow and hydraulic energy over the filter area, thereby maintaining the filter material in a more uniformly clean and effective filtering condition.

Abstract: The invention relates to a method and apparatus for filtering a liquid. The filtering is conducted using one or several filter elements in the filter housing, the operation being based on the alternation of filtering stages and air flushing stages. According to the invention, upon transferring from the flushing stage to the filtering stage, the filter housing is filled with liquid so that the liquid pushes the flushing air in the housing from the upper end of the housing into a separate air container so that air is compressed to a higher pressure in the container. During the filtering stage, air remains in the container, and after the filtering stage, air compressed in the container is allowed to push liquid out of the filter housing with its pressure. Further, the connection between the air container and the filter housing can be arranged so that air compressed in the container participates in the backflushing of the filter elements.

Abstract: A laminated modular water filter includes a top plate, a bottom plate and a plurality of superposed intermediate plates disposed between the top and bottom plates. Each adjacent pair of the top, intermediate and bottom plates are interconnected removably, and define an accommodating space therebetween, within which a filter unit is received fittingly. Each of the top and bottom plates has a central hole which is in fluid communication with central holes in the intermediate plates, and two side openings which are in fluid communication with a plurality of annular outer passages units in the intermediate plates that are in fluid communication with the accommodating spaces. Each of the filter units includes two filter films interconnected fixedly along outer peripheries thereof, and a filter net disposed between the films so as to define an annular filtered-water passage between the films that is fluid communication with the central holes.

Abstract: The invention relates to a filtering apparatus, the operation of which is based on alternating filtering and flushing stages. The apparatus comprises one or several filter elements placed into a filter housing supported by a casing, the filter housing being provided with an inlet assembly for the liquid flow to be filtered, an outlet assembly for the filtered liquid flow, and a channel for flushing the filter elements with air. Further, the filter housing is arranged to be prefilled with liquid before the next filtering stage is initiated after the flushing. According to the invention, a filling channel is directed into the filter housing through the casing, the channel being provided with a valve, which closes the channel at the same time as the filter housing is opened, for example, for changing the filter elements. Closing may be automatic.

Abstract: A filter device for filtering hydraulic fluid includes first and second subelements 40, 42 within a filter housing having separate inflows 20, 24 thereto for the respective subelements and a common outflow 22. The first subelement has a higher filter fineness than the second subelement. Several bypass configurations are taught and include: (i) a bypass line 28 for bypassing the second subelement by drawing fluid directly from the supply 95; (ii) a bypass valve 116 (FIG. 3) for bypassing the first subelement; and (iii) a bypass valve 151 (FIG. 5) for connecting the first subelement inflow 20 with the common outflow 22. The device is compact, has an easy-to-service arrangement, and ensures protection of a hydraulic pump and highly stressed hydraulic components.

Abstract: This invention relates to a backflushing filter, particularly for filtering lubricating oil. Filter candles 22 which are open at both ends 24, 34 are disposed around a rotary shaft 1 in the filter housing 11, 12, the interior space of which filter candles can be acted upon in filtration operation by a sludge which flows into the backflushing filter 10. A cleaning device is moved in conjunction by means of the rotary shaft 1, and comprises an upper flushing cock 27 and a lower flushing cock, which communicate with an outflow valve via the rotary shaft 1, for cleaning the filter candles 22′ during a backflushing operation. The upper flushing cock 27 is offset by an angle in the direction of rotation in relation to the lower flushing cock 37.

Abstract: Apparatus for cleaning a filter cloth in a filtering device with a rotatable drum having an inlet for the liquid to be filtered. The drum has in its circumferential surface openings through which the liquid to be filtered is conducted in a filtering direction out of the drum for filtering through a filter cloth. The cleaning apparatus includes at least one spray nozzle which is adapted to spray cleaning liquid onto a portion of the filter cloth in a direction opposite to the filtering direction. Moreover the apparatus comprises a driving device for providing a reciprocating motion of the spray nozzle. The driving device has a coupling which is adapted to transform the rotary motion of the drum into the reciprocating motion of the spray nozzle, with such a ratio that the rotary motion of the drum and the reciprocating motion of the spray nozzle are out of phase with each other.

Abstract: A method and apparatus of purifying feedwater to remove impurities including suspended solids therefrom, the method suitable for using in-line water pressure to permeate water through hollow fiber membranes and to backflush the membranes to remove solids collected or deposited thereon.

Abstract: A filtration device having a plurality of membrane modules is provided. Each of the plurality of membrane modules has first and second permeable sheets that are separated by a spacer, a first ring disposed around a perimeter of a first hole in the first permeable sheet, and a second ring disposed around a perimeter of a second hole in the second permeable sheet, the second hole in alignment with the first hole. The first ring of each of the plurality of membrane modules is in abutment with the second ring of a preceding one of each of the plurality of membrane modules so that the plurality of membrane modules are interconnected for communication therebetween. Some embodiments further provide a third sheet that disposed between successively adjacent membrane modules.

Abstract: A diffuser rod for use in a filter stalk having deflector disks rigidly mounted thereon to deflect liquid radially during the backwash process is disclosed. A backwashable filter element containing a diffuser plate that is located within the filter member at the end where the backwash fluid enters the filter member and a number of filter stalks with each filter stalk including a diffuser rod is disclosed. Finally, a method of backwashing a filter member that includes the step of introducing a diffuser rod and a diffuser plate to the filter assembly is disclosed.

Abstract: In a method and apparatus for cleaning filters in which raw gas with particles suspended therein is conducted from a raw gas space to a clean gas space and through which intermittently a back-flushing gas is conducted from the clean gas space to the raw gas space, a flow dynamic control element is disposed in the clean gas space which blocks the outflow of gas from the clean gas space when a back-flushing gas is admitted to the clean gas space under a pressure, which exceeds the filter operating pressure so as to prevent excessive back-flushing gas losses during back-flushing. The flow dynamic control element is switched between an open and a blocking state by the pressure changes in the clean gas space without including any movable parts.

Abstract: The invention relates to a device for cleaning the filter surface of a filter element, through which the liquid to be filtered flows, during a filtration operation using a pressurised cleaning fluid. According to an improvement of the invention, a distribution device is provided which delivers an essentially even pressure distribution of the cleaning fluid over the entire area of the filter surface to be cleaned.

Abstract: An improved waste treatment system and improved waste treatment system components are provided. In a preferred form, a waste stream is initially separated into primarily solid and primarily liquid components, and the liquids are then fed to a filter assembly. The filter assembly includes a pair of filter elements, and the flow is introduced into the filter assembly at a location between the filter elements. During a filtering operation, the liquid is pumped so that it is drawn through one of the filter elements. Periodically, the flow can be reversed, so that it is directed through the other filter element, at which time the first filter element can also be purged or back flushed. Advantageous waste treatment system arrangements are also provided for household, commercial, or transportation/marine use.

Abstract: An industrial, e.g. power plant cooling, water extraction framed cartridge filter system is disclosed with a holed fabric type medium to filter debris from the power plant cooling water. The fabric type filter medium is comprised a one or more strength meshes of nylon or another strong fiber and an inner polypropylene or polyester medium with small holes. The size of the frame and the number and arrangement of the holes are arranged to supply a volume of filtered water consistent with the needs of the application at the typical pressures found therein. For a power plant, a system of many cartridges may be used to provide the total cooling/replacement water needs. Compressed air is introduced into the bottom interior of the cartridges and released via a valve at the top. The compressed air mechanically disturbs the filter medium to knock off any debris that may have attached to the filter medium surface and air escaping via the small holed in the filter may attach to and float small pieces of debris away.

Abstract: A filtering device includes a container having an inlet for introducing liquid to be treated, an annular multi-layered prepacked screen assembly provided in the container and having an outlet for treated liquid. The screen assembly includes three or more cylindrical screens having different diameters and being coexially disposed in the container with their axes extending vertically in the container. An annulus is formed between the respective cylindrical screens. Two or more different filter materials performing different filtering functions are filled one in each of the annuluses between the cylindrical screens.

Abstract: A liquid filtration device having a backwashing feature in which liquid flow through the device is reversed with a plate being rotated under the filtration cartridges to allow reverse liquid flow into the individual filtration cartridges to produce the backwashing action.

Abstract: A continuous compression-type dewatering apparatus has a filter chamber (3), a drive shaft (17), a vane (15), and a supply path (50). The filter chamber (3) is delineated by an annular plate (2) and two side plates (1, 1). The drive shaft (17) passes through the center axis of the annular plate (2) and through the inside of the filter chamber (3), and is free to rotate with respect to the filter chamber (3). The vane (15) is disposed within the filter chamber (3), is fixed with respect to the drive shaft (17), and rotates in concert with the drive shaft (17). The supply path (50) passes through the drive shaft (17) and supplies raw fluid to the filter chamber (3). The vane (15) as two side edges (15a, 15a) facing the side plates (1, 1) and an end edge (15b) facing the annular plate (2). The side plates (1, 1) include a screen (4) for separating the raw fluid into a filtered fluid and a cake. The annular plate (2) includes an ejection port (7) for the cake.

Abstract: A method and apparatus for cleaning candles in a candle filter using a cleaning fluid that flows inside the candle from the side of the filtrate, whereby said fluid is pressed in an opposite direction to the direction of the filtrate from the inside to the outside, through said candles, by a gaseous medium subjected to an overpressure. Water is or can be used as an appropriate cleaning fluid and air is used as a gaseous medium. The prior art teaches nozzle-shaped contractions that are respectively disposed on the outlet end of the candles or deflectors arranged inside the candle at a distance from said contractions, whereby the in-flowing cleaning fluid is deflected towards all sides in the direction of the inner walls of the candles, are provided for distribution of said cleaning fluid.

Abstract: A method of operating a plant for filling containers by moving a liquid such as water through an apparatus with at least one portion for receiving the liquid before it is filtered and at least one portion for receiving the liquid after it is filtered, so that the liquid moves from at least an upper area of apparatus to lower area of the apparatus to be transferred to bottles or other containers.

Abstract: The present invention provides a multi-element filtering system assuring serial filtration of a liquid through multiple filter cartridges while enabling flushing without requiring removal of the filter cartridges. Both conventional and reverse osmosis filtration is performed, sequentially, within the system. The filter cartridges are held within a canister which is pressed against the cap and constrained against rotation with the cap. The canister is divided into chambers, and has passages in its floor arranged to enable serial transfer of liquid from one chamber to the next. Flushing employs liquid introduced under normal pressure. Passages leading to the flush liquid outlet enable flushing to proceed when the flush liquid outlet is opened. At other times, filtered liquid will pass through passages leading to the filtered liquid outlet. Liquid is circulated to assure filtration even when flushing, so that contamination of filtered liquid is precluded.

Abstract: The invention relates to a method and apparatus for filtering a liquid. The filtering is conducted using one or several filter elements in the filter housing, the operation being based on the alternation of filtering stages and air flushing stages. According to the invention, upon transferring from the flushing stage to the filtering stage, the filter housing is filled with liquid so that the liquid pushes the flushing air in the housing from the upper end of the housing into a separate air container so that air is compressed to a higher pressure in the container. During the filtering stage, air remains in the container, and after the filtering stage, air compressed in the container is allowed to push liquid out of the filter housing with its pressure. Further, the connection between the air container and the filter housing can be arranged so that air compressed in the container participates in the backflushing of the filter elements.

Abstract: A filter having filter elements with outwardly flanged ends sealed together. The seal may be secured by use of a rod extending in a lengthwise direction through apertures in the flanged ends. The rod has one end releasably securing the filter element and a second end secured to the housing. A frame can cover the filter elements, and a jack screw in the frame can be used to apply force to the filter elements to secure the seals. The filter may have a cleaning apparatus capable of suctioning material from the filter element.

Abstract: A cleanable backflushable re-usable dual full-flow and bypass filter includes a full-flow filter element providing filtered primary flow therethrough, a bypass filter element providing filtered secondary flow therethrough, a bypass tube conducting flow therethrough from said bypass filter element to said full-flow filter element, a venturi creating a low pressure zone aiding secondary flow through the bypass tube to assist in pulling the secondary flow through the more restrictive bypass filter element, wherein fluid, whether main fluid flow in the filtering direction or backflushing cleansing fluid flow in the opposite direction, flowing from the bypass tube changes direction at the venturi.

Abstract: In an apparatus containing rotating filter media that removes solids from a fluid stream, the invention provides devices and methods for improved cleaning of the filter media. Solids trapped on the filter media are removed by the application of a suction pressure that draws the filter media into contact with a backwash shoe. The backwash shoe has one or more orifice slots in a radially tapered or oblique angular configuration or in a combination of radially tapered and oblique angular configurations. The orifice slot configuration creates an hydraulic condition where the unit of orifice area applied per unit filter area has a generally uniform ratio across the rotating filter media. This configuration equalizes the distribution of the backwash flow over the filter area, thereby maintaining the filter media in a more uniformly clean and effective filtering condition.

Abstract: A filtering device includes a container having an inlet for introducing liquid to be treated, an annular multi-layered prepacked screen assembly provided in the container and having an outlet for treated liquid. The screen assembly includes three or more cylindrical screens having different diameters and bieng coazially disposed in the container with their axes extending vertically in the container. An anulus is formed between the respective cyldinrical screens. Two or more different filter materials performing different filtering functions are filled one in each of the annuluses between the cylindrical screens.

Abstract: A multimedia fluid treatment unit and rotatable valve are disclosed in which a plurality of discreet containers are removably stacked upon each other and contain various different and distinct water treating media. The rotatable valve is rotatable between either of three positions one of which is a service position for routing the water to be treated through the unit for treatment, a second of which is a rinse position for rinsing the media in the unit, and a third of which is a backwash position for backwashing and/or regenerating the media.

Abstract: Device for filtering a liquid. The filter device is provided with at least two filter elements (8, 15) placed parallel to each other. A three-way cock (6, 13) is accommodated in the pipe (4, 5) to each filter element (8, 15) for connection of the inflow opening of each filter element (8, 15) to a mains system (3) for supplying the liquid with sufficient pressure to press the liquid through the filter device. The three-way cocks (6, 13) are mutually connected by a pipe (19). A drain (23) to a sewer is provided which has a closing device (21), which is connected to a branch point (26) of the pipe (19) via a pipe (20). A three-way cock (10, 17) is accommodated in the pipe (9, 16) of each filter element (8, 15) for connecting the outflow opening of each filter element (8, 15) to a mains system (12) of a user. The three-way taps (10, 17) are mutually connected by a pipe (24).

Abstract: A filtering device includes a cylindrical screen 2 having a rotatable backwash tube 3 provided coaxially therein. The backwash tube includes a first end portion including an inlet 3c for introducing filtered liquid and a second end portion including an opening 3d for discharging filtered liquid and introducing backwash water. A plurality of backwash water injection holes 13d are formed along the backwash tube in an axial direction thereof at a predetermined interval. A check valve 14 is disposed within the backwash tube adjacent the inlet 3c such that in a filtration operation filtered liquid is allowed to flow from the inlet 3c into the backwash tube 3 and then into the liquid transfer tube 9. In a backwash operation, the check valve prohibits backwash water from flowing to the inlet from the backwash tube.