Abstract: A method and apparatus for removing fouling materials from the surface of a plurality of porous membranes (9) arranged in a membrane module (4) by providing, from within the module, by means (10) other than gas passing through the pores of said membranes, gas bubbles in a uniform distribution relative to the porous membrane array such that the bubbles move past the surfaces of the membranes (9) to dislodge fouling materials therefrom. The membranes (9) are arranged in close proximity to one another and mounted to prevent excessive movement therebetween. The bubbles also produce vibration and rubbing together of the membranes to further assist removal of fouling materials.

Abstract: A system is provided for withdrawing permeate from a substrate. The exemplary system includes a vessel configured to contain substrate, two or more compartments configured to receive substrate from the vessel and to return a portion of received substrate to the vessel, and a filter positioned at least partially within each of the compartments and configured to separate permeate from substrate during operation of the filter. At least one of the compartments is configured to contain cleaning solution and substantially prevent cleaning solution from contacting substrate in the vessel during cleaning of the filter. The exemplary system is configured for cleaning the filter in situ in at least one of the compartments while operating the filter in at least one other of the compartments. A method for adapting a filtration system for cleaning thereof and a method for withdrawing permeate from a substrate using a filtration system are also provided.

Abstract: Input water is preheated in a heat exchanger (2), pumped (4) through another heat exchanger (5) into a heating unit (6). The heating unit heats the water to a temperature of above 100° C., preferably 140-150° C., while maintaining the water in a liquid state without vaporization. A pump (8) feeds the heated water under sufficient pressure to prevent vaporization to at least one crossflow filtration unit (9). A portion of the heated water passes through a thermally stable filtration material having a pore size of 1-20 nanometers for filtering endotoxins and pyrogens, 4-10 nanometers for filtering viruses, or 100 nanometers−30 &mgr;m for filtering bacteria. Heated water which has passed through the filtration material is fed through a pure water product outlet of the filtration unit to a pure water outlet (16). A retenate portion of the heated water flows past the filtration material to carry filtered impurities through a retenate output line (10).

Abstract: An aerator for immersed filtering membranes has an aerator shell with openings for discharging bubbles from its upper surface and a shape capable of temporarily containing a volume of air in fluid communication with the openings. The shell is open to tank water below it and located so that discharged bubbles will rise through an assembly of the filtering membranes. The shell may be wholly or partially made of parts of the assemblies of filtering membranes. A supply of air is provided to the air space in the aerators alternating between a high flow rate and a low flow rate in short cycles of between about 10 seconds and 100 seconds. A filtration system has an inlet for adding substrate and an outlet for retentate are located so as to create a horizontal flow of substrate through the tank. Membrane assemblies are located within the horizontal flow of substrate. Aerators as described above are provided and operated as described above.

Abstract: One or more aerators move below an area of an assembly of immersed filtering membranes to be aerated. The movement can take various forms including the sweep of a pendulum. Positions in the assembly of membranes may be alternately aerated for a period of time and then not aerated for a period of time.

Abstract: A microbial resistant water purification and collection system includes a reverse osmosis filter assembly 19 having a filter inlet in selective fluid communication with a system inlet and a filter outlet in fluid communication with a water storage container 12 for storing filtrate. At least a portion of the storage container is located at an elevation above the filter membrane such that filling of the storage container creates a head pressure in the storage container relative to the filter membrane to enable a backflow of filtrate therethrough. A mechanical shut-off valve 27 is interposed the system inlet 11 and the filter inlet to block fluid communication therebetween, wherein activation of the shut-off valve occurs by the physical contact thereof with the storage container upon reaching a minimum head pressure in the storage container relative to the filter membrane.

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: A method for preventing activation of the contact phase of blood or plasma which comes into contact with a semi-permeable membrane based on polyacrylonitrile bearing fixed negative charges, which is fitted in apparatus for the treatment of blood or plasma, by extra-corporal circulation, said method comprising contacting blood or plasma with said semi-permeable membrane, wherein: a neutral or cationic polymer is combined with said semi-permeable membrane before or after formation of the membrane, and before sterilization of the membrane; the overall ionic capacity of the semi-permeable membrane, based on polyacrylonitrile bearing fixed negative charges and containing a neutral or cationic polymer, is negative; the overall ionic capacity of the semi-permeable membrane, based on polyacrylonitrile bearing fixed negative charges and containing a neutral or cationic polymer, is, as an absolute value, not more than 10% less than the overall ionic capacity of the same semi-permeable membrane without a neutral or cati

Abstract: A filtration apparatus in which a rotating filter element is concentrically mounted in a hollow conical of cylindrical chamber. The filter element consists of a support and a membrane mounted on the support. Fluid enters the chamber through an inlet port and concentrate leaves the chamber through an outlet port. Filtrate drains through the membrane and support to a channel in the centre of the filter element. Filtration relies upon cross-flow of the fluid across the surface of the rotating filter element. This reduces the tendency of solids in the fluid to block pores of the membrane, thereby maintaining high flux and minimising the requirement for cleaning of the filter.

Abstract: A method and apparatus for optimizing the filtration of process fluid. The system provides establishing a peak flow rate of permeate through a filter and then engaging a filtering cycle in which process fluid is passed through the filter until such time as the flow rate of permeate through the filter reaches a predetermined level which is set as a function of the initial permeate flow rate. At that point in time, a cleaning cycle is entered, during which cleaning fluid is passed through the filter for such a period of time as is necessary to allow the permeate flow rate with the cleaning solution to stabilize. At that point in time, the processing of process fluid is recommenced and the process continues on a repetitive basis between the processing of process fluid and the cleaning of the filter.

Abstract: A spiral wound membrane element allowing back wash reverse filtration at 0.05 MPa to 0.3 MPa is employed for a spiral wound membrane module. Air injection of injecting air of not more than 0.3 MPa into a permeate outlet of the spiral wound membrane module from a pressurized air feeder through a pipe, back wash reverse filtration with permeate and flushing with raw water are performed as recovery of a filtration velocity. Another spiral wound membrane module comprises a spiral wound membrane element including a separation membrane having high back pressure strength. Raw water into which bubbles are diffused by an air diffuser is fed to the spiral wound membrane element stored in a pressure vessel. Part of the raw water is axially fed through the spiral wound membrane element, discharged from a raw water outlet of the pressure vessel and thereafter returned to a raw water tank through a pipe.

Abstract: The present invention includes a system and method for transferring a selected solute species from a fluid mixture to a fluid media. The system of the present invention includes a convergent channel for passing a fluid mixture containing a selected species tangentially across the first surface of a porous membrane. A fluid media is directed to flow tangentially over the second surface of the membrane. As the fluid mixture and the fluid media flow on opposite sides of the membrane, the selected species traverses the membrane leaving the fluid mixture and entering the fluid media. The volumetric loss to the fluid mixture associated with the loss of the selected species is compensated for by the convergency of the channel. As a result a constant velocity is maintained over the membrane, maximizing the selectivity of the filtration process.

Abstract: The invention relates to an apparatus for analyzing water and wastewater, including a housing which is immersible in the water or wastewater to be analyzed, an analyzer for determining at least one water or wastewater parameter, a membrane separating a sample space from a filtrate space, and a conduit connecting the filtrate space to said analyzer. Also described are embodiments containing device to clean or eliminate soilage from the membrane. The analyzer, membrane and conduit are located in the housing.

Abstract: The present invention relates to an apparatus and a method for analyzing the amount of chemical substrates in a liquid, more particularly in a clarified solution or a process water. The apparatus comprises a separate filtration housing in which a filter medium is arranged for arresting the filtrate supplied to an analyzer. Provided in the filtration housing is a gas supply means by means of which the filter medium is charged or flushed with a gas.

Abstract: A spiral wound membrane module comprises a spiral wound membrane element including a separation membrane having high back pressure strength. In filtration running, raw water introduced from a raw water inlet of a pressure vessel is subjected to dead end filtration, and permeate is taken out from a permeate outlet. In washing, wash water containing a chemical having a contaminant separating function is introduced from an end of a water collection pipe through the permeate outlet for performing back wash reverse filtration with a back pressure of 0.05 to 0.3 MPa. The filtration running is temporarily stopped for maintaining the pressure vessel in a state sealed with the raw water and the permeate for a prescribed time. Thus, contaminants adhering to the membrane surface of the spiral wound membrane element are separated. A treatment system is formed by connecting units comprising spiral wound membrane modules in parallel with each other.

Abstract: The invention concerns a water treatment method and installation, which consist in subjecting the water to be treated to membrane filtration (1) to satisfy the requirement for a relatively high flowrate of water for ordinary use (UF), subjecting the water that has been subjected to membrane filtering to reverse osmosis filtering (2) to satisfy the requirement for a smaller flowrate of water of improved quality (OS) and, outside periods of production of water filtered by reverse osmosis, sweeping the upstream face of the osmosis membrane (9) with the flow of membrane-filtered water drawn off to be consumed.

Abstract: A wash water pipe having a flushing valve inserted therein is connected with a concentrated water outlet pipe connected to a concentrated water outlet of a fresh water generating cartridge. A timer controls opening and closing of the flushing valve. The flushing valve is periodically opened during interruption of fresh water generation work with the fresh water generating cartridge or during fresh water generation work, or opened simultaneously with interruption of fresh water generation work or when restarting fresh water generation work, for performing flushing. Thus, the linear velocity on the surface of a reverse osmosis membrane of the fresh water generating cartridge is increased and impurities remaining on the membrane surface are discharged from the fresh water generating cartridge.

Abstract: A reverse osmosis water treatment system includes a tube connecting unit 10 having a water incoming end 102, a water outgoing end 103, and a diaphragm 104 having a check valve 108 therein to allow water to flow directly from the incoming end to the outgoing end. In operation, water flows from the tube connecting unit through-hole 105 and into preliminary filtering units 2 and membrane unit 3 via the pipe assembly 1. Wastewater from the membrane unit drain end 31 is then routed back to the tube connecting unit via pipe assembly 42 and through-hole 106. A faucet 5 is provided at the water outgoing end to deliver water for non-drinking uses. By virtue of issuing water from the outgoing end, the membrane is washed and cleaned. Accordingly, the amount of discharged wastewater is greatly reduced so that water resources are conserved and the useful life of the membrane is prolonged.

Abstract: A system is provided for withdrawing permeate from a substrate through a filter and for cleaning the filter in situ. The system includes a vessel configured to contain a substrate and a compartment connected to receive substrate from the vessel and connected to return a portion of received substrate to the vessel during normal operation of the system. The system also includes a filter positioned at least partially within the compartment to withdraw permeate from substrate in the compartment during normal operation of the system. A source of cleaning solution is connected to the compartment to deliver cleaning solution into the compartment and into contact with the filter during cleaning operation of the system. The compartment facilitates circulation of substrate in the vessel during normal operation of the system and substantially prevents introduction of cleaning solution from the compartment into contact with substrate contained in the vessel during cleaning operation. A method is also provided.

Abstract: The invention concerns a gas diffuser constructed and arranged to disperse gas into a aeration vessel of a water treatment assembly from a blower. The gas diffuser includes main pipes, branch pipes extending between the main pipes and containing gas discharge ports, wherein the branch pipes have a smaller cross-sectional area than the cross-sectional area of the main pipes. The gas discharge ports are further sized, constructed and arranged to reduce the possibility or likelihood of sludge from blocking the ports or entering the branch pipes. This object is achieved either by placement of the ports on the bottom sides of the branch pipes or, alternatively, by construction of the ports to include conduit members, themselves having an arrangement of openings or coverings to prevent or reduce the likelihood of sludge from blocking the ports or entering the branch pipes.

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 filtering element has ultrafiltration or microfiltration hollow fibre membranes extending horizontally between a pair of opposed horizontally spaced, vertically extending headers. Side plates extending between the pair of vertically extending headers define a vertical flow channel through the element. Modules are created by placing the elements side by side or in an orthogonal grid. A frame restrains the elements in place without obstructing the vertical flow channels. Each element may be released from the frame, however, and removed by sliding it in a direction substantially normal to its headers without disassembling the remainder of the module. The elements have associated releasable water tight fittings between the elements and a permeate collector, the releasable water tight fittings being releasable by removing of an element from the frame. An aerator is located below the module with a plurality of air holes.

Abstract: A vibratory separation system having a drive mechanism for imparting a vibratory motion to a membrane module to enhance filtration. The membrane module comprises one or more filter elements secured to one another, each having a permeable membrane. The vibratory motion imparted to the membrane module generates a dynamic flow boundary layer at the permeable membranes. This fluid shear boundary layer, in turn, generates lift, thereby inhibiting fouling of the membranes.

Abstract: This invention teaches a system and method to improve the renewal of water being filtered and to prevent the accumulation of solids within a cassette of multiple vertical skeins of hollow fibers used in membrane filtration.

Abstract: A dialysis system which does not need to use a physiological saline in replenishing a solution or cleaning and priming the dialysis system, does not need a troublesome setting operation and can easily and accurately set a flow rate of a replenisher solution. The dialysis system includes a closed type water-removal control apparatus 1, a dialyzer 2, a fresh dialysate line 3 as well as a used dialysate line 4, a dialysate pressurizing line 5, a dialysate pressurizing pump 51 provided in the dialysate pressurizing line 5, an artery side blood line 6, a blood pump 61 provided in the artery side blood line 6 and a vein side blood line 7. According to the dialysis system, by pressurizing a dialysate into a communication line of the dialysate, the dialysate is made to flow from a dialysate flow path 21 into a blood flow path 22 through a dialysis membrane 23 of the dialyzer 2 and the inside of a blood circulation path can be cleaned and primed.

Abstract: A new centrifuge filter is designed for use in an arrayable micro-centrifuge. The filter has an upstream end where fluid enters the filter, an opposite or downstream end, and sides where fluid exits by centrifugal force. The filter is a piece of semipermeable material which is capable of letting certain fluids and small molecules pass therethrough and retaining macromolecules and particles. Also disclosed is an optional support for the filter.

Abstract: A filtration process for filtering water with immersed microfiltration or ultrafiltration membranes in a batch mode includes repeated cycles comprising the steps of filling the tank to a level above the membranes, withdrawing permeate through the membranes, aerating the membranes to dislodge solids from the membranes and backwashing the membranes while draining the tank. The backwashing steps involve backwashings with a cleaning chemical interspersed with backwashings with permeate. The backwashings with a cleaning chemical follow a regimen of maintenance cleaning chosen to maintain acceptable permeability of the membranes or to reduce the rate of decline in permeability of membranes 24 over extended periods of time.

Abstract: An aeration system for a submerged membrane module has a set of aerators connected to an air blower, valves and a controller adapted to alternately provide a higher rate or air flow and a lower rate of air flow in repeated cycles. In an embodiment, the air blower, valves and controller, simultaneously provide the alternating air flow to two or more sets of aerators such that the total air flow is constant, allowing the blower to be operated at a constant speed. In another embodiment, the repeated cycles are of short duration. Transient flow conditions result in the tank water which helps avoid dead spaces and assists in agitating the membranes.

Abstract: An element of immersed, suction driven, filtering membranes has a plurality of hollow fiber membranes suspended between upper and lower headers. The lower header is movable between a first position in which the fibers are substantially elongated and second position in which the two headers are closer to each other by between 1 and 4% of the un-potted length of the membranes. The weight of the lower header is sufficient to keep the lower header in the first position in substantially quiescent water while allowing the lower header to rise to the second position in upwardly flowing water. Aerators are mounted generally below the elements and supply scouring bubbles to each element at a higher rate and then at a rate less than one half of the higher rate in repeated cycles. The cycles are preferably between 10 seconds and 60 seconds in duration. The lower header rises to the second position when bubbles are supplied at the higher rate and falls to the first position when bubbles are supplied at the lower rate.

Abstract: A filtration device is provided for withdrawing permeate essentially continuously from a multicomponent aqueous substrate containing growing microorganisms in a reservoir. A vertical skein of fiber is scrubbed with coarse bubbles which emanate from a conversion baffle positioned under the skein. The substrate is aerated with fine bubbles in a size range small enough to transfer oxygen to the substrate efficiently. The baffle traps the fine bubbles and converts them to coarse bubbles which are effective to scrub the fibers. In the most preferred embodiment, the finished headers of the skein are derived from composite headers comprising a fixing lamina of resin in which the fibers are potted near their terminal ends, and a fugitive lamina of fugitive powdery material in which the terminal ends of the fibers are potted. The fugitive lamina is removed, preferably by dissolving the powder, e.g. finely divided common salt in water.

Abstract: An apparatus for providing a predetermined volume of biocidally treated water to a feed water side of a reverse osmosis device when it is shut down. A biocide dispenser treats a predetermined volume of water from a source with a biocidal agent. A valve, coupled to the source of the predetermined volume of water, transfers the predetermined volume of water to the feed water side of the reverse osmosis device. A controller, coupled to the valve, causes the transfer of the predetermined volume of water after a source of feed water connected to the feed water side of the reverse osmosis device is shut off, and then causes the predetermined volume of water to remain in the feed water side of the reverse osmosis device while the reverse osmosis device is shut down.

Abstract: A membrane separator assembly for separating solids from water includes opposing enclosure wall structures, a membrane module unit, and a gas diffuser disposed below the membrane module unit. The membrane module unit includes a plurality of membrane modules respectively having at least one separating membrane extending between at least two membrane fixing members. At least one of the membrane fixing members has a main passage which is in fluid communication with a membrane passageway. The membrane passageway is accessible to water via permeation through the separating membranes and is inaccessible to solids which are impermeable relative to the separating membranes. The membrane separator assembly is preferably used with a detergent containing percarbonate, preferably sodium percarbonate. The assembly also includes a gas diffuser with two opposing main pipes and branch pipes extending therebetween to avoid undesired pressure differentials when cleaning the assembly.

Abstract: Apparatus and methods for providing sterile substitution solutions from a dialysis fluid used in connection with the treatment of a patient's blood in an extracorporeal circuit are disclosed. The apparatus includes pumps or valves for comparing the flow of fresh dialysis fluid prior to treatment and after treatment of a patient's blood and a throttle which divides the fresh dialysis circuit into a positive pressure portion and a negative pressure portion, a sterile filter including a membrane disposed in the positive pressure portion of the dialysis circuit, and a valve for controlling the pressure in the positive pressure portion to pass a predetermined amount of the fresh dialysis fluid through the membrane in a sterile filter to provide a predetermined amount of the sterile substitution solution for addition to the extracorporeal circuit.

Abstract: In cleaning by sodium hypochlorite, filtration membrane cartridges are immersed in a washing tank storing a solution of sodium hypochlorite to decompose and remove organic contaminants clogging the pores of filtration membranes by oxidation of sodium hypochlorite; in rinsing with water, the cartridges are immersed in a washing tank storing a rinsing water to wash away the sodium hypochlorite attached to the filtration membrane by the rinsing water; in cleaning by oxalic acid, the cartridges are immersed in a washing tank storing oxalic acid to wash away ferrous substances attached to the filtration membrane by oxalic acid; and in giving hydrophilic property by a hydrophilic agent, the cartridges are immersed in a washing tank storing a solution of the hydrophilic agent so as to apply the hydrophilic agent to the filtration membranes in preparation for dry lay-up.

Abstract: The invention relates to a filter assembly for producing a paste-like filter cake and a substantially solids free filtrate or permeate. The filter assembly includes a substantially cylindrical member having an exterior foraminous surface, the cylindrical member being mounted on an elongate shaft for rotating the surface about an axis defined by the shaft. The exterior foraminous surface is covered by a microporous filter media. A stationary housing is positioned adjacent a portion of the exterior surface of the cylindrical member. The stationary housing includes a filter feed inlet and a sealing device and is spaced from the exterior surface a distance sufficient to enable cross flow relative to the filter media. Unique filter seal members promote retention of fluid to be filtered in a filtration area defined by the housing and cylindrical member. As the cylindrical member is rotated about the axis, a cake removal or membrane cleaning device removes filter cake from the filter media.

Abstract: A system is provided for the heat disinfection of a fluid supply system for a dialysis machine. The system is provided with plastic conduits constructed of a material suitable for heat disinfection, preferably cross linked polyethylene conduit. A source of hot water is provided, and the hot water is flowed through the plastic conduit for sufficient time and at a sufficient temperature to disinfect the plastic conduit. This system uses a heat exchanger that utilizes fluid provided from a boiler to heat the water. The fluid supply system may employ bicarbonate fluid.

Abstract: A self-regenerating filter unit having a housing which carries an ultrasonic transducer periodically energizable to dislodge caked solids from a filter element in the housing. The removed solids collect in a storage zone where they are periodically removed.

Abstract: A system wherein an ultrasound emitter, or gun, is provided which emits an ultrasound beam directed at filter media, on the opposite side of the filter media from where solids accumulate, in order to knock the solids from the filter media. Dislodged solids from the area targeted by the beam are driven upstream, away from the filter media. Gravity then draws the solids to a drain of a collection chamber, which allows for the solids to be safely removed from the system. A guide is provided upstream of the filter media, the guide having angled slats or vanes. These vanes are angled upwardly towards the filter media and downwardly towards the drain, such that as the solids are blasted from the filter media by the gun, they are jolted upstream, and impact the angled vanes upon their downstream return.

Abstract: A membrane filter having one or more ducts is disclosed herein. Each of the ducts has a porous wall defining a lumen surrounded by helical grooves in the respective wall. The groove can be a single, double, or triple start groove defining a flow direction along the groove. The cross sectional area of the groove in the case of a single start groove, or aggregate cross sectional area of the groove in the case of a double or triple start groove, perpendicular to the flow direction along the lumen is within a range of 75% to 125% of the cross sectional area of the lumen. The helical grooves create vortices which reduce concentration polarization while increasing membrane area.

Abstract: A water treatment process using a membrane separation apparatus to separate clean product water from a contaminated water source, the membrane is provided within a housing having inlet ports for collecting concentrated and product water, and the apparatus also includes a concentration chamber and a venturi for injecting gas in the concentration chamber and producing a return stream.

Abstract: A desalinator is disclosed for removing dissolved solids from sea water or brackish water. The desalinator (10) comprising a casing (12) into which a pump (14) driven by a motor (16) pumps sea water or brackish water under pressure. A desalination cartridge (76) within the casing (12) includes semi-permeable material which acts as a reverse osmosis membrane and through which permeate is forced to separate it from the sea water or brackish water. The solids dissolved in the brackish water or sea water are retained in the salt retention passages of the cartridge (76). Three electrical coils (94, 96 and 98) encircle the cartridge (76) and are embedded in the walls of the casing (12). The coils are supplied with current from a supply (112) which is preferably a 50 Hertz, 380 Volt three phase supply. The coils are also connected by lines (108) to an adjustable frequency AC drive (110) which is in turn connected to the motor (16).

Abstract: A system is provided for withdrawing permeate from a substrate through a filter and for cleaning the filter in situ. The system includes a vessel configured to contain a substrate and a compartment connected to receive substrate from the vessel and connected to return a portion of received substrate to the vessel during normal operation of the system. The system also includes a filter positioned at least partially within the compartment to withdraw permeate from substrate in the compartment during normal operation of the system. A source of cleaning solution is connected to the compartment to deliver cleaning solution into the compartment and into contact with the filter during cleaning operation of the system. The compartment facilitates circulation of substrate in the vessel during normal operation of the system and substantially prevents introduction of cleaning solution from the compartment into contact with substrate contained in the vessel during cleaning operation. A method is also provided.

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: The invention relates to the reduction and prevention of biofouling in facilities utilizing water, e.g. sea water, carrying biological organisms, without causing corrosion, chemical reaction or other detrimental action from the additive or environmental discharge problems. Such operations include, for example, desalination plants, power plants, oilfield water injection facilities and shipboard or ocean platform fire water systems. For example, in the desalination plant of FIG. 1, the biofouling reduction method and apparatus for this invention have a source of oxidizing agent such as chlorine ions or ozone, a source of copper ions and a dosing chamber for delivery of relatively low dosage levels of oxidizing agents and at appropriate times copper ions to form a treatment additive. Flow connectors connect the dosing chamber to various points along the piping in the desalination plant.

Abstract: The invention relates to a method for treatment of liquid, that is meant particularly for filtering of pressurized liquid, such as water led from a water distribution system, by way of an apparatus, which has an essentially closed frame (1), in connection with which there has been arranged at least a filtering device (2) for purifying of liquid and a flow device (3), such as feed-flow and/or exhaust flow arrangements (3a, 3b) for leading of liquid. The filtering device (2) is made of thin filtering film (2a), advantageously made of plastic based material, such as PTM (Particle Track Membrane), TeM (Track-etch Membrane) or like, the thickness of which is preferably 7-25 &mgr;m and the size of pores of which is 0.05-10 &mgr;m. The filtering film (2a) belonging to a filtering device (2) are being purified essentially self-powered, such as by way of a purification device (5) exploiting the pressure (p) or the movement (v1) of the liquid to be treated and/or the liquid that has been treated.

Abstract: A filtration system for a cross-flow membrane filter which reduces the deleterious effects of concentration polarization and membrane fouling, thereby increasing the average transmembrane flux. The filtration system includes a feed supply for providing a feed solution; a feed pump connected to the feed supply; a cross-flow membrane filter connected downstream of the feed pump for separating the feed into a permeate and a retentate, the cross-flow membrane filter including at least two membrane ports and at least two permeate outlets; a valve manifold assembly located between the feed pump and the cross-flow membrane filter; and a control system for controlling the valve manifold to selectively reverse the flow of the feed through the cross-flow membrane filter.

Abstract: A vertical skein of “fibers”, opposed terminal portions of which are held in headers unconfined in a modular shell, is aerated with a gas-distribution means which produces a mass of bubbles serving the function of a scrub-brash for the outer surfaces of the fibers. The membrane device is surprisingly effective with relatively little cleansing gas, the specific flux through the membranes reaching an essentially constant relatively high value because the vertical deployment of fibers allows bubbles to rise upwards along the outer surfaces of the fibers. Further, bubbles flowing along the outer surfaces of the fibers make the fibers surprisingly resistant to being fouled by build-up of deposits of inanimate particles or microorganisms in the substrate provided that the length of each fiber is only slightly greater than the direct center-to-center distance between opposed faces of the headers, preferably in the range from at least 0.1% to about 5% greater.

Abstract: A method and apparatus for achieving reverse osmosis, microfiltration, nanofiltration and ultrafiltration, produces Dean vortices against a membrane surface which is advantageously in a form of a wound helical membrane tube.