MEMBRANE FILTRATION DEVICE AND MEMBRANE FILTRATION ASSEMBLY COMPRISING SUCH MEMBRANE FILTRATION DEVICE

Abstract

The present invention relates to a membrane filtration assembly and membrane filter for providing pure water. The membrane filter includes an evaporation chamber, a condensation chamber, and a membrane (9) separating the evaporation chamber and the condensation chamber and having a pore size of 1000 nanometers or less. The membrane is a multi-layer polymeric membrane including a nonwoven first layer (46) and a spunbonded second layer (47), the nonwoven first layer (46) having a pore size of 1000 nanometers or less and the spunbonded second layer (47) laminated to the first layer and facing the condensation chamber (8). The membrane filter includes a rigid first polymer frame (41) having a first surface (48), a second surface (49) and a central opening (50) extending between the first surface (48) and the second surface (49), at least a portion of the condensation chamber being defined by the central opening (50), a membrane (9) is connected to the first surface (48) of the first polymer frame (41) covering the central opening (50), and a second layer (47) of the membrane (9) faces the first surface (48) of the first polymer frame (41).

Description

[Technical field]

[0001] The present invention relates generally to a membrane filtration assembly configured to remove particles from water, i.e., to produce pure water, and more particularly to membrane filters used in industrial applications and configured to produce pure water. More specifically, the present invention relates to a membrane filtration assembly capable of producing nano / ultra-purified water that is free of particles larger than 10 nanometers.

[0002] The present invention is particularly directed to membrane filters which include an evaporation chamber, a condensation chamber, and a membrane separating the evaporation chamber and the condensation chamber, the membrane having a pore size of 1000 nanometers or less.

[0003] The present invention also relates to a membrane filtration assembly for providing pure water. The membrane filtration assembly comprises: a membrane filter configured to produce pure water, the membrane filter having an evaporation chamber and a condensation chamber, the evaporation chamber and the condensation chamber being separated from each other by a membrane, the membrane having a pore size of 1000 nanometers or less; a water tank connected to the membrane filter for intermediate storage of pure water; a water supply unit connected to the membrane filter; a pure water dispenser tool connected to a water reservoir; Includes.

[0004] Such membrane filters and membrane filtration assemblies are particularly useful in the semiconductor manufacturing industry, where semiconductor wafers are passed through multiple cleaning steps using pure water. [Background technology]

[0005] The present invention is based on the fact that semiconductors are getting smaller and smaller to meet the demand for faster and cheaper electronic devices that consume less energy. Thus, the semiconductors / structures on the silicon wafers are getting smaller and the distance between the structures is getting smaller to include more semiconductors / structures on the wafer. Thus, the demand for more efficient washing of the equally small contaminants from the wafers to avoid short circuits or failure of the semiconductors increases, and the washing water needs to utilize ultrapure water to avoid contaminating the wafers. To obtain the required washing results, the washing of the wafers consumes a large amount of ultrapure water, but the production of ultrapure water is time-consuming and energy-consuming, and the useful life of ultrapure water is short, i.e., less than 30 minutes. Thus, the transport of ultrapure water through tanks or pipes causes contamination, i.e., by the growth of existing contaminants and by the increase of contaminants from the material of the tanks / pipes. Conventional membrane filtration assemblies cannot produce the required amount of pure water because the conventional technology is too slow.

[0006] Also, the prior art has problems in connecting / welding the membrane to its carrier / frame to obtain a sealed relationship between the evaporation chamber and the condensation chamber, so if the membrane is not perfectly connected / welded to the carrier / frame when it is installed in the membrane filter, leakage may occur if the membrane is distorted or wrinkled.

[0007] Thus, there is a need for equipment configured to efficiently produce large volumes of ultra-pure water at the point of use, i.e., near the washing station in a clean room. In addition to being used as a detergent, pure water can also be used as a solvent in different industrial applications. Summary of the Invention

[0008] Object of the Invention The aim of the present invention is to overcome the drawbacks and shortcomings of conventional membrane filters and membrane filtration assemblies and provide an improved membrane filter and membrane filtration assembly. The main object of the present invention is to provide an improved membrane filter and membrane filtration assembly of the initially defined type, which always provides the required amount of pure water and is available in the clean room of a semiconductor / wafer manufacturing plant. Another object of the present invention is to provide a membrane filter and membrane filtration assembly that allows for simultaneous and continuous production and utilization of pure water. Another object of the present invention is to provide a membrane filter and membrane filtration assembly that reduces the required amount of pure water by increasing the degree of purification of the pure water. Another object of the present invention is to provide a membrane filter and membrane filtration assembly that consumes less tap water. Another object of the present invention is to provide a membrane filter and membrane filtration assembly in which the membrane is more easily fixed in the membrane filter.

[0009] (Summary of the invention) According to the present invention, at least one main object is achieved by a membrane filter and a membrane filtration assembly as defined initially, which have the features defined in the independent claims. Preferred embodiments of the invention are further defined in the dependent claims.

[0010] According to the present invention, there is provided a membrane filter and a membrane filtration assembly of the initially defined kind, in which the membrane is a multi-layer polymer membrane comprising a nonwoven first layer and a spunbonded second layer, the nonwoven first layer having a pore size of 1000 nanometers or less, the spunbonded second layer being laminated to the first layer and facing the condensation chamber, the membrane filter comprises a rigid first polymer frame having a first surface, a second surface and a central opening extending between the first and second surfaces, at least a part of the condensation chamber being defined by the central opening, the membrane is connected to the first surface of the first polymer frame covering the central opening, the second layer of the membrane facing the first surface of the first polymer frame.

[0011] Thus, the present invention is based on the insight of a new design / construction of a membrane, which improves the ability to increase the production of pure water and ensures a problem-free production of pure water. More precisely, the inventive multi-layer membrane provides a higher output without compromising the required degree of purification, while the spunbonded second layer ensures that there is always a distance between the first layer of the membrane and the surface / wall of the condensation chamber. Since the pressure in the evaporation chamber is higher than the pressure in the condensation chamber, contact of the filtration layer, i.e. the first layer, of the membrane with the wall of the condensation chamber adversely affects the output of purified water. According to the inventive membrane filter, the first layer / filtration layer of the membrane does not have to be optimized for connection / welding to the first polymer frame, instead the second layer of the membrane is optimized for connection / welding to the first polymer frame and the first layer of the membrane is optimized for filtration.

[0012] According to various embodiments of the present invention, the first layer of the membrane comprises a fluoropolymer and the second layer of the membrane comprises a thermoplastic polymer. Thus, the first layer of the membrane / filtration layer can be optimized to ensure hydrophobicity and obtain the required degree of purification, and the second layer of the membrane can be optimized to provide a stable structure that prevents contact between the first layer and the walls of the condensation chamber. More precisely, the second layer is not compressible but always provides a volume into which the vapor from the evaporation chamber can condense.

[0013] According to various embodiments of the present invention, the membrane filter includes a cooling chamber located adjacent to the condensation chamber, so that proper and efficient cooling in the condensation chamber is achieved.

[0014] According to various embodiments of the present invention, the membrane filter includes a film that separates the cooling chamber from the condensation chamber, and the thickness of the film is 0.08 mm or more and 0.25 mm or less, so that proper and efficient cooling in the condensation chamber is achieved, and the film is properly connected / welded to its carrier / frame. If the film is thin, it is very difficult / impossible to be connected / welded to the carrier / frame, and if the film is thick, the cooling efficiency is reduced.

[0015] According to various embodiments of the present invention, the membrane filter includes a rigid second polymer frame having a first surface, a second surface, and a central opening extending between the first and second surfaces. A film separating the cooling chamber and the condensation chamber is connected to one of the first surface of the second polymer frame covering the central opening and the second surface of the second polymer frame covering the central opening. Thus, proper and efficient cooling of the condensation chamber is achieved and the film is properly connected to its carrier / frame.

[0016] Further features and advantages of the invention will become apparent from the other dependent claims and the following detailed description of preferred embodiments.

[0017] A more complete understanding of the above mentioned features and advantages of the present invention, as well as other features and advantages of the present invention, will be apparent from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0018] [Figure 1] Schematic diagram of the main components of a membrane filtration assembly [Diagram 2] Schematic diagram of a water reservoir of a membrane filtration assembly according to a first embodiment. [Diagram 3] Schematic diagram of a water reservoir of a membrane filtration assembly according to a second embodiment. [Figure 4] Schematic diagram of the water supply unit of the membrane filtration assembly [Diagram 5] 1 is a schematic exploded side view of a membrane filter according to a schematic embodiment. [Figure 6] Schematic side view of a membrane filter based on FIG. [Figure 7] FIG. 7 is a schematic side view of an alternative embodiment of a membrane filter according to FIG. [Figure 8] 1 is a schematic side view of another schematic embodiment of a membrane filter. [Figure 9] Schematic diagram of the first endplate of the membrane filtration according to FIG. 8 [Figure 10] Schematic diagram of the first gasket of the membrane filtration according to FIG. [Figure 11] Schematic diagram of the first polymer frame of the membrane filtration according to FIG. [Figure 12] Schematic diagram of the second gasket of the membrane filtration according to FIG. [Figure 13] Schematic diagram of the second polymer frame of the membrane filtration according to FIG. [Figure 14] Schematic diagram of the third gasket of the membrane filtration according to FIG. [Figure 15] Schematic diagram of the second end plate of the membrane filtration according to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Reference is initially made to FIG. 1 which shows a schematic diagram of the main components of a membrane filtration assembly generally designated by the reference numeral 1.

[0020] The membrane filtration assembly 1 includes a membrane filter 2 configured to produce pure water such as ultrapure water, a water supply unit 3 connected to the membrane filter 2 and configured to supply water to be treated by the membrane filter 2, a water tank 4 connected to the membrane filter 2 and configured to receive the pure water from the membrane filter 2, and a pure water dispenser tool 5 connected to the water tank 4. The water tank 4 is configured to intermediately / temporarily store the pure water.

[0021] The water supply unit 3 is connected to a water source 6, such as water mains, i.e. connected to tap water. The pure water dispenser tool 5 may be a manual nozzle / handle or an automatically controlled nozzle.

[0022] The membrane filter 2 includes a sealed evaporation chamber 7 and a sealed condensation chamber 8, which are separated by a membrane 9. The condensation chamber 8 is also known as a gas chamber. According to various embodiments, the membrane filter 2 includes a plurality of sets of evaporation chambers 7 and condensation chambers 8, which are connected in parallel. Preferably, each evaporation chamber 7 is associated with two condensation chambers 8, which are disposed on each side of the evaporation chamber 7 and are disposed opposite each other. The membrane 9 has a pore size of 1000 nanometers or less, preferably a pore size of 750 nanometers or less, and more preferably a pore size of 500 nanometers or less. The membrane 9 has a pore size of 100 nanometers or more. Generally, a relatively small pore size can provide clean water, but the production of pure water is slow. The pores should be small enough to prevent liquid penetration.

[0023] The water supply unit 3 supplies water to the evaporation chamber 7, i.e. the evaporation chamber 7 is filled with hot water. For example, the evaporation chamber 7 is filled with hot water at a temperature of more than 80° C. and less than 90° C. Such water cannot pass through the membrane 9, but the steam at the interface between the water and the membrane 9 passes through the membrane 9 into the condensation chamber 8, leaving the contaminants in the evaporation chamber 7. The temperature in the condensation chamber 8 is lower than the temperature in the evaporation chamber 7. That is, the condensation chamber 8 is cooled, in which the steam accumulates / condenses into droplets. The condensation chamber 8 includes a cold surface 10, where efficient condensation takes place. The droplets accumulate and finally flow to the bottom of the condensation chamber 8, where the pure water leaves the membrane filter 2 and enters the water tank 4. The pressure difference between the evaporation chamber 7 and the condensation chamber 8 is less than 0.5 bar, i.e. the water is not forced / pressurized to pass through the membrane 9.

[0024] The membrane 9 should be made of a thermally and chemically stable material, such as polytetrafluoroethylene (PTFE), polypropylene (PP), polyvinylidene fluoride (PVDF), or the like.

[0025] The water tank 4 includes at least one tank 11a for intermediate / temporary storage of pure water. In the following, the water tank 4 includes at least two tanks 11a, 11b, but the present invention is not limited to the water tank 4 including two tanks 11a, 11b. The tanks 11a, 11b are connected in parallel between the membrane filter 2 and the pure water dispenser tool 5. During the operation of the membrane filtration assembly 1, the first tank 11a is filled with pure water from the membrane filter 2 and the second tank 11b provides pure water to the dispenser tool 5, or the second tank 11b is filled with pure water from the membrane filter 2 and the first tank 11a provides pure water to the dispenser tool 5. Thus, the water tank supplies ultrapure water in time at the point of use. That is, the two tanks mentioned above are filled alternately to alternately supply ultrapure water to the dispenser tool. Thus, the production and use of pure water can be performed simultaneously and continuously.

[0026] It should be noted that the first tank 11a does not need to be completely filled before the pure water therein is utilized, nor does it need to have all the pure water therein utilized before being filled. Preferably, the first tank 11a is filled to the same extent / extent as the demand for pure water of the dispenser tool 5 over the time it takes to fill the second tank 11b.

[0027] Pure water used during wafer cleaning or the like may be collected in gutter / drain 12 and recycled back to water source 6. Gutter / drain 12 may include a suitable filter to prevent contaminants / materials that have entered the water during the cleaning step from reaching water source 6. Membrane filtration assembly 1 may include a prefilter located between water source 6 and water supply unit 3.

[0028] Reference is made to FIG. 2, which shows a schematic diagram of a water reservoir 4 of a membrane filtration assembly 1 according to a first embodiment.

[0029] According to various embodiments, each of the tanks 11a, 11b includes an intermediate pipe 13 and an outlet pipe 15, the intermediate pipe 13 being connected to the membrane filter 2 and having a controllable intermediate valve 14, and the outlet pipe 15 being connected to the pure water dispenser tool 5 and having a controllable outlet valve 16. Thus, the separate tanks of the water reservoir 4 can be filled and emptied separately. The tanks 11a, 11b are arranged so that the pure water automatically flows to the outlet pipe 15, which is connected to the tank at its lowest point.

[0030] In the event that the pure water in the tank 11a is not used in time, i.e. before the useful life of the pure water in the first tank 11a is over and / or before the second tank 11b is filled up, what remains in the first tank 11a is drained / discarded before the pure water in the second tank 11b is used. This draining / discarding can be a manual operation of directing the dispenser tool 5 to the gutter / drainage device 12. The same operation applies to a water reservoir 4 having only one tank 11a. Thus, any old / unsuitable water in the separate tanks can be drained or recycled without affecting the pure water supply to the dispenser tool.

[0031] Reference is made to FIG. 3, which shows a schematic diagram of a water reservoir 4 of a membrane filtration assembly 1 according to a second embodiment.

[0032] According to various embodiments, each of the tanks 11a, 11b includes a drain / waste pipe 17 having a controllable drain valve 18 and bypassing the dispenser tool 5. In this way, drain / waste of what remains in one of the tanks 11a, 11b can be performed automatically while the pure water in the other tank 11a, 11b is available to the dispenser tool 5. The drain pipe 17 is preferably connected to the water source 6 directly or indirectly via a gutter / drain device 12. The same arrangement applies to a water reservoir 4 having only one tank 11a.

[0033] When the tanks 11a, 11b are emptied, it is important that no residue remains in the tanks, as this may contaminate the next batch of pure water. According to various embodiments, the membrane filtration assembly 1 includes a gas source 19, preferably a gas source 19 of a gas such as nitrogen. Each of the tanks 11a, 11b includes an air supply tube 20, which is connected to the gas source 19 and has a controllable gas valve 21. Pressurized gas from the gas source 19 is utilized to empty the tanks 11a, 11b via the outlet valve 16 and / or the exhaust valve 18. The air supply tube 20 is preferably connected to the tanks 11a, 11b near the intermediate tube 13 or via the intermediate tube 13 downstream of the intermediate valve 14.

[0034] Reference is now also made to FIG. 4, which shows a schematic diagram of the water supply unit 3 of the membrane filtration assembly 1.

[0035] According to various embodiments, the water supply unit 3 includes a primary water supply pipe, generally designated by reference number 22, which is connected to the evaporation chamber 7 of the membrane filter 2 and includes a heater 23. Thus, the water supplied to the evaporation chamber 7 is already preheated to a suitable / correct temperature when it reaches the evaporation chamber.

[0036] The primary water supply pipe 22 includes a water conditioner 24, which is configured to control the flow rate and pressure of the water supplied to the evaporation chamber 7 via the primary water supply pipe 22. The water conditioner 24 is preferably formed by a pump, which operates automatically to prevent the pressure in the evaporation chamber 7 from becoming too high.

[0037] According to various embodiments, the water supply unit 3 includes a buffer tank 25 connected to the primary water supply pipe 22. The buffer tank 25 is preferably associated with the heater 23, but the buffer tank 25 and the heater 23 may be located in series with each other. Also, the water supply pipe 26 is connected to the buffer tank 25 or the water conditioner 24 and is configured to be connected to the water source 6. The water supply pipe 26 includes a controllable fill valve 27 to fill the buffer tank 25 or operate the water conditioner 24. According to various embodiments, the water supply unit 3 includes a primary return water pipe 28 extending from the evaporation chamber 7 to the buffer tank 25. Water that is not purified in the membrane filter 2, i.e., water that has not passed through the membrane 9, is returned / recycled, and such water is beneficial because it is already at a high temperature. The buffer tank 25 preferably includes a water level sensor to control the fill valve 27. The primary water supply pipe 22 preferably includes an air vent.

[0038] The water supply unit 3 includes a pressure regulator 29 to prevent the pressure upstream of the water conditioner 24 from becoming too high. The pressure regulator 29 may be located between the water source 6 and the water supply unit 3.

[0039] The flow rate generated by the water conditioner 24 is in the range of 1 to 5 liters / minute, and the production amount of pure water reaching the water tank 4 is in the range of 1 to 4 liters / minute.

[0040] According to various embodiments, the membrane filter 2 includes a sealed cooling chamber 30 located adjacent the condensation chamber 8. The cooling chamber 30 is thus configured to provide a cold surface 10. Preferably, the membrane filter 2 includes a film / partition / foil 31 separating the cooling chamber 30 from the condensation chamber 8, i.e. the cold surface 10 is part of the film / partition 31. The cooling chamber 30 contains liquid / water or gas. Alternatively, the cold surface 10 is part of a cooling block / chiller.

[0041] According to various embodiments, the thickness of the film 31 is 0.08 mm or more and 0.25 mm or less, preferably 0.1 mm or more and 0.2 mm or less. Thus, the film 31 is resistant to deformation and easy to install, while still providing low thermal insulation. The cold surface 10 should be as smooth as possible to encourage the flow of pure water downward. Preferably, the film 31 is a hydrophobic material, preferably including a fluoropolymer such as polyvinylidene fluoride (PVDF).

[0042] According to various embodiments, the water supply unit 3 includes a secondary water supply pipe, generally designated by reference number 32, which is connected to a cooling chamber 30 of the membrane filter 2 and includes a cooler 33. Thus, the water in the cooling chamber 30 has a suitable temperature to efficiently condense the water vapor in the condensation chamber 8 into pure water.

[0043] The secondary water supply pipe 32 includes a water conditioner 34 configured to control the flow rate and pressure of the water supplied to the cooling chamber 30 via the secondary water supply pipe 32. The water conditioner 34 is preferably formed by a pump, which operates automatically to prevent the pressure in the cooling chamber 30 from becoming too high.

[0044] According to various embodiments, the water supply unit 3 includes a buffer tank 35 connected to the secondary water supply pipe 32. Preferably, the buffer tank 35 is associated with the cooler 33, but the buffer tank 35 and the cooler 33 may be in series with each other. Also, a water supply pipe 36 is connected to the buffer tank 35 or the water conditioner 34 and configured to be connected to the water source 6. The water supply pipe 36 includes a controllable fill valve 37 to fill the buffer tank 35 or to supply water to the water conditioner 34. According to various embodiments, the water supply unit 3 includes a secondary return pipe 38 extending from the cooling chamber 30 to the buffer tank 35. The cooling water is returned / recycled, which is beneficial because it reduces water usage.

[0045] The buffer tank 35 preferably includes a water level sensor to control the fill valve 37. The secondary water supply pipe 32 preferably includes an air bleed structure.

[0046] Preferably, the cooler 33 is a thermoelectric heat pump, which may be, for example, a Peltier device that uses electrical power to transfer heat from one side of the element to the other. Heat is transferred from liquid / water in the secondary water supply pipe 32, preferably in a buffer tank 35, to the surrounding air. According to an alternative embodiment, such a thermoelectric heat pump is directly associated with the cooling chamber 30.

[0047] Preferably, at least the water reservoir 4 and the tubing extending from the condensation chamber 8 to the dispenser tool 5 are treated so that the surfaces facing the pure water are hydrophobic to promote the flow of the pure water.

[0048] Reference is made to Figures 5 to 7 showing schematic diagrams of a schematic membrane filter 2. The membrane filter 2 comprises different configurations / elements stacked to provide an evaporation chamber 7, a condensation chamber 8 and a cooling chamber 30. However, preferably, the stacked membrane filter 2 may comprise multiple sets of such combinations installed parallel to each other. Preferably, the top set and the bottom set in the stacked configuration comprise the cooling chamber 30 to minimize heat radiation to the surrounding environment / clean room.

[0049] The stacked membrane filter 2, according to the disclosed general embodiment, includes a first end plate 39, preferably made of metal, a first resilient gasket 40, a membrane 9, a first rigid polymer frame 41, a second resilient gasket 42, a second rigid polymer frame 43, a film 31, a third resilient gasket 44, and a second end plate 45, preferably made of metal.

[0050] According to the disclosed embodiment, a first end plate 39 delimits the evaporation chamber 7 and a second end plate 45 delimits the cooling chamber 30. That is, the end plates delimit the exterior / adjacent chambers.

[0051] According to the present invention, the membrane 9 is a multilayer polymer membrane comprising a nonwoven first layer 46 and a spunbonded second layer 47, the nonwoven first layer 46 having a pore size of 1000 nanometers or less, and the spunbonded second layer 47 laminated to the first layer 46 and facing the condensation chamber 8. Thus, the first layer 46 faces the evaporation chamber 7. According to various embodiments, the thickness of the membrane 9 is 0.1 mm or more and 0.4 mm or less, preferably 0.2 mm or more and 0.3 mm or less. Thus, the first layer 46 of the membrane 9 is the actual filtration layer. The first layer 46 of the membrane 9 preferably comprises a fluoropolymer such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF). The second layer 47 of the membrane 9 preferably comprises a thermoplastic polymer such as polypropylene (PP). The first layer 46 and the second layer 47 are manufactured separately before being laminated together to minimize intrusion of the second layer 47 into the first layer 46, thereby minimizing blockage of the pores of the first layer 46.

[0052] The rigid polymer frame / carrier 41, 43 preferably comprises a rigid fluoropolymer such as polyvinylidene fluoride (PVDF), and the elastic gasket 40, 42, 44 preferably comprises an elastic fluoropolymer such as polytetrafluoroethylene (PTFE). The rigid polymer frame 41, 43 maintains its initial thickness when the membrane filter 2 is installed / compressed. The elastic gasket 40, 42, 44 reduces its thickness from the initial thickness in response to the membrane filter 2 being installed / compressed. The elastic gasket is preferably compressed to 25% or more and 40% or less of its initial / unloaded thickness. Too little compression may cause leakage, and too much compression may cause the reduced gasket to lose its sealing / elastic properties and cause leakage. When the stacked membrane filters 2 are installed / compressed, the first end plate 39 and the second end plate 45 are clamped together, and the distance element has an appropriate length between the end plates to prevent excessive clamping. Thus, the appropriate length for the distance element is equal to the sum of the final / compressed thickness of the gasket and the thickness of the polymer frame.

[0053] The first polymer frame 41 includes a first surface 48, a second surface 49, and a central opening 50 extending between the first surface 48 and the second surface 49, with the condensation chamber 8 being at least partially defined by the central opening 50. The membrane 9 is connected / welded to the first surface 48 of the first polymer frame 41, the first surface 48 covering the central opening and a second layer 47 of the membrane 9 facing the first surface 48 of the first polymer frame 41. The membrane 9 can be connected to the first polymer frame 41 by other suitable means such as adhesive, but welding (ultrasonic welding) is preferred. The second layer 47 of the membrane 9 facilitates the connection between the membrane 9 and the first polymer frame 41.

[0054] The second polymer frame 43 includes a first surface 51, a second surface 52, and a central opening 53 extending between the first surface 51 and the second surface 52. The film 31 is connected / welded to one of the first surface 51 of the second polymer frame 43 covering the central opening and the second surface 52 of the second polymer frame 43 covering the central opening. The film 31 can be connected to the second polymer frame 43 by other suitable means such as adhesive, but welding (ultrasonic welding) is preferred. When the film 31 is connected to the second surface 52 of the second polymer frame 43 (see FIG. 6), the central opening 53 constitutes at least a part of the condensation chamber 8. When the film 31 is connected to the first surface 51 of the second polymer frame 43 (see FIG. 7), the central opening 53 constitutes at least a part of the cooling chamber 30.

[0055] The resilient first gasket 40 includes a first surface 54, a second surface 55, and a central opening 56 extending between the first surface 54 and the second surface 55, with the evaporation chamber 7 defined at least in part by the central opening 56. An inlet 57, which is part of the primary supply pipe 22, extends into the central opening 56 at the bottom of the first gasket 40, and an outlet 58, which is part of the primary return pipe, extends from the central opening 56 at the top of the first gasket 40.

[0056] The resilient second gasket 42 includes a first surface 59, a second surface 60, and a central opening 61 extending between the first surface 59 and the second surface 60, with the condensation chamber 8 defined at least in part by the central opening 61. An outlet 62, which is part of the intermediate tube 13, extends from the central opening 61 at a lower portion of the second gasket 42. The second gasket 42 may include an air vent structure 63 to prevent a pressure buildup within the condensation chamber 8.

[0057] The resilient third gasket 44 includes a first surface 64, a second surface 65, and a central opening 66 extending between the first surface 64 and the second surface 65, and at least a portion of the cooling chamber 30 is defined by the central opening 66. An inlet 67, which is part of the secondary supply pipe 32 or primary supply pipe 22, extends into the central opening 66 at an upper portion of the third gasket 44, and an outlet 68, which is part of the secondary return pipe 38, extends from the central opening 66 at a lower portion of the third gasket 44.

[0058] Reference is made to Figures 8 to 15 which show further schematic views of the schematic membrane filter 2. Only what is added to / what is different from the schematic embodiment of Figures 5 to 7 will be described.

[0059] According to various embodiments, the membrane filter 2 includes a primary water supply manifold 69, which extends between the first surface 54 and the second surface 55 of the first gasket 40 at the bottom of the first gasket 40, and the inlet 57 extends from the primary water supply manifold 69 to the central opening 56 of the first gasket 40. The primary water supply manifold 69 is a part of the primary water supply pipe 22 and extends from the first gasket 40 to the outside of the membrane filter 2, for example, through any intermediate element to the outer surface 70 of the first end plate 39. The primary water supply manifold 69 may extend through the entire membrane filter 2, i.e., from the outer surface 70 of the first end plate 39 to the outer surface 71 of the second end plate 45. Preferably, all the evaporation chambers 7 are connected to the primary water supply manifold 69.

[0060] According to various embodiments, the membrane filter 2 includes a primary return water manifold 72, which extends between the first surface 54 and the second surface 55 of the first gasket 40 on top of the first gasket 40, and the outlet 58 extends from the central opening 56 of the first gasket 40 to the primary return water manifold 72. The primary return water manifold 72 is a part of the primary return water pipe 28 and extends from the first gasket 40 to the outside of the membrane filter 2, for example, through any intermediate elements to the outer surface 70 of the first end plate 39. The primary return water manifold 72 may extend through the entire membrane filter 2, i.e., from the outer surface 70 of the first end plate 39 to the outer surface 71 of the second end plate 45. Preferably, all the evaporation chambers 7 are connected to the primary return water manifold 72.

[0061] According to various embodiments, the membrane filter 2 includes a pure water manifold 73, which extends between the first surface 59 and the second surface 60 of the second gasket 42 under the second gasket 42, and the outlet 62 extends from the central opening 61 of the second gasket 42 to the pure water manifold 73. The pure water manifold 73 is a part of the intermediate tube 13 and extends from the second gasket 42 to the outside of the membrane filter 2, for example, through any intermediate element to the outer surface 70 of the first end plate 39. The pure water manifold 73 may extend through the entire membrane filter 2, i.e., from the outer surface 70 of the first end plate 39 to the outer surface 71 of the second end plate 45. Preferably, all condensation chambers 8 are connected to the pure water manifold 73. The pure water manifold 73 is preferably coated / lined with a hydrophobic material, preferably comprising a fluoropolymer such as polyvinylidene fluoride (PVDF), to ensure that the pure water leaves the membrane filter 2. The coating / lining extends along the entire pure water manifold 72, eliminating the risk of clogging at the interfaces between the different frames and gaskets. The coating / lining must not block the outlet 62 that extends from the condensation chamber 8 to the pure water manifold 73.

[0062] According to various embodiments, the membrane filter 2 includes a vent manifold 74, which extends between the first surface 59 and the second surface 60 of the second gasket 42 on top of the second gasket 42, and the air vent structure 63 extends from the central opening 61 of the second gasket 42 to the vent manifold 74. The vent manifold 74 extends from the second gasket 42 to the outside of the membrane filter 2, for example, through any intermediate elements to the outer surface 70 of the first end plate 39. The vent manifold 74 may extend through the entire membrane filter 2, i.e., from the outer surface 70 of the first end plate 39 to the outer surface 71 of the second end plate 45. Preferably, all condensation chambers 8 are connected to the vent manifold 74.

[0063] According to various embodiments, the membrane filter 2 includes a second water supply manifold 75, which extends between the first surface 64 and the second surface 65 of the third gasket 44 on top of the third gasket 44, and the inlet 67 extends from the central opening 66 of the third gasket 44 to the second water supply manifold 75. The second water supply manifold 75 is a part of the second water supply pipe 32 and extends from the third gasket 44 to the outside of the membrane filter 2, for example, through any intermediate element to the outer surface 71 of the second end plate 45. The second water supply manifold 75 may extend through the entire membrane filter 2, i.e., from the outer surface 70 of the first end plate 39 to the outer surface 71 of the second end plate 45. Preferably, all cooling chambers 30 are connected to the second water supply manifold 75.

[0064] According to various embodiments, the membrane filter 2 includes a second return water manifold 76, which extends between the first surface 64 and the second surface 65 of the third gasket 44 at the bottom of the third gasket 44, and the outlet 68 extends from the central opening 66 of the third gasket 44 to the second return water manifold 76. The second return water manifold 76 is a part of the second return water pipe 38 and extends from the third gasket 44 to the outside of the membrane filter 2, for example, through any intermediate element to the outer surface 71 of the second end plate 45. The second return water manifold 76 may extend through the entire membrane filter 2, i.e., from the outer surface 70 of the first end plate 39 to the outer surface 71 of the second end plate 45. Preferably, all cooling chambers 30 are connected to the second return water manifold 76.

[0065] 9 to 15 show different elements of the membrane filter 2 according to FIG. 8, seen from the first surface 70 of the first end plate 39. In FIG.

[0066] FIG. 10 shows a first gasket 40, in which the opening of the inlet 57 at the central opening 56 is located at one of the lower corners and the opening of the outlet 58 at the central opening 56 is located at the opposite upper corner to obtain an optimal distribution of water / heat throughout the evaporation chamber 7. Preferably, the cross-sectional area of ​​the inlet 57 is smaller than the cross-sectional area of ​​the primary feed water manifold 69, preferably less than 50% of the cross-sectional area of ​​the primary feed water manifold 69. Preferably, the inlet 57 includes a bend between the primary feed water manifold 69 and the central opening 56. Preferably, the cross-sectional area of ​​the outlet 58 is smaller than the cross-sectional area of ​​the primary return water manifold 72, preferably less than 50% of the cross-sectional area of ​​the primary return water manifold 72. Preferably, the outlet 57 includes a bend between the primary return water manifold 72 and the central opening 56.

[0067] FIG. 12 shows the second gasket 42 in which the opening of the outlet 62 at the central opening 61 is located in the middle of the bottom and the opening of the air vent structure 63 at the central opening 61 is located in the middle of the top to obtain optimal drainage of the pure water from the condensation chamber 8.

[0068] FIG. 14 shows a third gasket 44 with the inlet 67 opening at the central opening 66 located at one of the upper corners and the outlet 68 opening at the central opening 66 located at the opposite lower corner for optimal water / heat distribution throughout the cooling chamber 30. Preferably, the cross-sectional area of ​​the inlet 67 is smaller than the cross-sectional area of ​​the secondary feed water manifold 75, preferably less than 50% of the cross-sectional area of ​​the secondary feed water manifold 75. Preferably, the inlet 67 includes a bend between the secondary feed water manifold 75 and the central opening 66. Preferably, the cross-sectional area of ​​the outlet 68 is smaller than the cross-sectional area of ​​the secondary return water manifold 76, preferably less than 50% of the cross-sectional area of ​​the secondary return water manifold 76. Preferably, the outlet 67 includes a bend between the secondary return water manifold 76 and the central opening 66.

[0069] The primary supply water manifold 69 and the secondary return water manifold 76 are preferably each located at one of the lower corners of the membrane filter 2, and the primary return water manifold 72 and the secondary supply water manifold 75 are preferably each located at one of the upper corners of the membrane filter 2.

[0070] (Examples of changes that can be implemented) The present invention is not limited to the above description and the embodiments shown in the drawings, which are for illustrative purposes only. This patent application is intended to cover all variations and modifications of the preferred embodiment described herein. The present invention is therefore defined by the language of the appended claims. The device can therefore be varied in all possible ways within the framework of the appended claims.

[0071] It should also be noted that all information relating to / relating to terms such as top, bottom, upward, downward, etc., should be interpreted / deciphered with reference to the device oriented in the drawings in such a way that the reference numbers can be properly read, and thus such terms are only indicative of relative relationships in the illustrated embodiment, which may be altered if a different construction / design is provided for the device according to the present invention.

[0072] It should also be noted that even if a feature of a particular embodiment is not explicitly stated as being combinable with a feature of another embodiment, the combination is deemed explicit if such a combination is possible.

Claims

1. A membrane filter (2) for providing pure water, an evaporation chamber (7); a condensation chamber (8); a membrane (9) separating the evaporation chamber (7) and the condensation chamber (8) and having a pore size of 1000 nanometers or less; Including, The membrane (9) is a multilayer polymer membrane comprising a nonwoven first layer (46) and a spunbonded second layer (47), the nonwoven first layer (46) having a pore size of 1000 nanometers or less, the spunbonded second layer (47) being laminated to the first layer (46) and facing the condensation chamber (8), the membrane filter (2) comprising a rigid first polymer frame (41), the first polymer frame (41) having a first surface (48) and a second surface (49) and extending between the first surface (48) and the second surface (49). a central opening (50) extending through the membrane filter (2) and at least a portion of the condensation chamber (8) being defined by the central opening (50); the membrane (9) is connected to the first surface (48) of the first polymer frame (41) covering the central opening (50); the second layer (47) of the membrane (9) faces the first surface (48) of the first polymer frame (41); the membrane filter (2) includes a cooling chamber (30) located near the condensation chamber (8); and a film (31) separates the cooling chamber (30) from the condensation chamber (8). Membrane filter.

2. The thickness of the membrane (9) is 0.1 mm or more and 0.4 mm or less, preferably 0.2 mm or more and 0.3 mm or less. The membrane filter according to claim 1.

3. the pore size of the first layer (46) of the membrane (9) is 750 nanometers or less, preferably 500 nanometers or less; The membrane filter according to claim 1 or 2.

4. the first layer (46) of the membrane (9) comprises a fluoropolymer such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF); The membrane filter according to claim 1.

5. the second layer (47) of the membrane (9) comprises a thermoplastic polymer such as polypropylene (PP); The membrane filter according to claim 1.

6. The membrane filter (2) includes a rigid second polymer frame (43), the second polymer frame (43) having a first surface (51), a second surface (52), and a central opening (53) extending between the first surface (51) and the second surface (52), and the polymer film (31) is connected to one of the first surface (51) of the second polymer frame (43) covering the central opening (53) and the second surface (52) of the second polymer frame (43) covering the central opening (53). The membrane filter according to claim 1.

7. The thickness of the polymer film (31) is 0.08 mm or more and 0.25 mm or less, preferably 0.1 mm or more and 0.2 mm or less. The membrane filter according to claim 1.

8. The membrane filter (2) includes a resilient first gasket (40), the first gasket (40) including a first surface (54), a second surface (55), and a central opening (56) extending between the first surface (54) and the second surface (55), at least a portion of the evaporation chamber (7) being defined by the central opening (56), an inlet (57) extending into the central opening (56), and an outlet (58) extending from the central opening (56). The membrane filter according to claim 1.

9. The membrane filter (2) includes a resilient second gasket (42), the second gasket (42) including a first surface (59), a second surface (60), and a central opening (61) extending between the first surface (59) and the second surface (60), at least a portion of the condensation chamber (8) being defined by the central opening (61), and an outlet (62) extending from the central opening (61). The membrane filter according to claim 1.

10. The membrane filter (2) includes a resilient third gasket (44), the third gasket (44) including a first surface (64), a second surface (65), and a central opening (66) extending between the first surface (64) and the second surface (65), at least a portion of the cooling chamber (30) being defined by the central opening (66), an inlet (67) extending into the central opening (66), and an outlet (68) extending from the central opening (66). An outlet (62) extends from said central opening (61); The membrane filter according to claim 1.

11. The polymer frame (41, 43) comprises a rigid fluoropolymer, such as polyvinylidene fluoride (PVDF). The membrane filter according to claim 1.

12. The gaskets (40, 42, 44) comprise a resilient fluoropolymer such as polytetrafluoroethylene (PTFE). The membrane filter according to claim 8.

13. The film (31) comprises a fluoropolymer such as polyvinylidene fluoride (PVDF). The membrane filter according to claim 1.

14. A membrane filtration assembly (1) for providing pure water, comprising: a membrane filter (2) configured to produce pure water, the membrane filter (2) having an evaporation chamber (7) and a condensation chamber (8), the evaporation chamber (7) and the condensation chamber (8) being separated by a membrane (9); a water tank (4) connected to the membrane filter (2) for temporarily storing pure water; a water supply unit (3) connected to the membrane filter (2); a pure water dispenser tool (5) connected to the water reservoir (4); Including, The membrane (9) is a multilayer polymer membrane comprising a nonwoven first layer (46) and a spunbonded second layer (47), the nonwoven first layer (46) having a pore size of 1000 nanometers or less, the spunbonded second layer (47) being laminated to the first layer (46) and facing the condensation chamber (8); The membrane filter (2) comprises a rigid first polymer frame (41), the first polymer frame (41) having a first surface (48), a second surface (49), and a central opening (50) extending between the first surface (48) and the second surface (49), at least a portion of the condensation chamber (8) being defined by the central opening (50), the membrane (9) being connected to the first surface (48) of the first polymer frame (41) covering the central opening (50), the second layer (47) of the membrane (9) facing the first surface (48) of the first polymer frame (41), the membrane filter (2) comprising a cooling chamber (30) located near the condensation chamber (8), and a film (31) separating the cooling chamber (30) from the condensation chamber (8). Membrane filtration assembly.

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