Filter unit having filter element and screening device

Abstract

Provided herein is a filter unit comprising a filter element and a screening device. The screening device includes a screen body, an aperture positioned substantially in a center of the screening device, an outer ring in an outer periphery of the screening device, and the screen body between the aperture and the outer ring. Further provided is a filtration system comprising a vessel, a feed port, a permeate outlet, optionally a retentate outlet, and at least a filtration unit within the vessel. For at least one of the filter units, a screening device is positioned upstream of the filter element.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to International Application No. PCT / CN23 / 143102, filed December 29, 2023, pursuant to 35 U.SC §365(c), which in turn claims priority to U.S. Provisional Patent Application No. 63 / 477,616, filed December 29, 2022, each of which is incorporated herein by reference in its entirety. Technical Field

[0003] This document provides a filtration unit comprising a filter element and an integrated pre-filter. Further, a filtration system comprising the filter unit is provided. More specifically, the pre-filter includes a screening device, which in turn includes an orifice substantially located at the center of the screening device, an outer ring in the outer periphery of the screening device, and a screen body between the orifice and the outer ring. The outer ring includes an outer surface that connects to the inner surface of the housing of the filter element. Background Technology

[0004] This specification references several patents, patent applications, and publications to provide a more comprehensive description of the level of technological development involved in this invention. The full disclosure of each of these patents, patent applications, and publications is incorporated herein by reference.

[0005] Filter media (such as membranes, including reverse osmosis (RO) membranes, nanofiltration (NF) membranes, ultrafiltration (UF) membranes, microfiltration (MF) membranes, electrodialysis (ED) membranes, distillation membranes, degassing membranes, and ion exchange membranes) are commonly and effectively used in fluid handling. By applying a driving force (in most cases, pressure) to one surface of the membrane, it can separate the feed fluid into a permeate flow that passes through the membrane and a effluent flow containing the filter material. The most important application is water purification, through the treatment of process streams such as industrial waste, seawater, groundwater, sewage, and effluents from wastewater treatment facilities. Other industrial uses include the purification and / or concentration of dairy products, juices, and other beverages; enzyme recovery; and dialysis.

[0006] MF membranes typically have pore sizes ranging from 0.1 micrometers to several micrometers, which can be used to remove large microbial material, such as some bacteria. UF membranes typically have pore sizes between 0.1 micrometers and 0.01 micrometers, small enough to separate a wider range of microorganisms (including viruses and other pathogens), as well as macromolecules, nanoparticles, proteins, and biological cell debris. NF membranes typically have pore sizes between 0.001 micrometers and 0.01 micrometers to effectively remove divalent ions, most organic molecules, almost all viruses, and a range of salts. RO membranes typically have pore sizes between 0.0001 micrometers and 0.001 micrometers, and are by far the finest membranes industrially available for removing all organic molecules, viruses, and most minerals.

[0007] Membranes are susceptible to fouling and damage from larger particles. Therefore, coarse and / or fine sieves are used to treat the feed fluid before it enters the filtration system to remove large particles that could damage or clog the membrane. Typically, for UF and MF systems, pretreatment includes using self-cleaning filters with sieve sizes from 50 to 400 micrometers, more preferably from 100 to 300 micrometers. UF and / or MF membranes are often used as pretreatment for finer RO and NF membranes.

[0008] Because pre-filters used in pretreatment are designed to remove larger particles, they are prone to clogging and require frequent cleaning, such as backwashing and / or chemical cleaning, to restore the original flux. UF and MF membranes are used to remove relatively large particles; these membranes also require regular cleaning. Normal cleaning processes for UF and MF membranes include, but are not limited to, backwashing, air rinsing, chemically enhanced backwashing (CEB), and in-situ cleaning (CIP). Backwashing is the most commonly used cleaning process for UF and MF membranes, typically cyclicated every 20 to 60 minutes based on feed conditions. For RO and NF membranes, which are often composite membranes, CIP is an effective cleaning process. In industrial and wastewater treatment settings, pretreatment is performed using a separate pre-filter system upstream of the filtration system; that is, the pretreatment filter is typically a separate unit from the downstream filtration system. In these cases, the pretreatment filter and the filtration system typically involve separate and time-consuming cleaning processes.

[0009] To reduce system footprint, piping volume, and the number of connections, multiple filter elements can be incorporated within a single pressure vessel to form a multi-element filtration system. In these designs, the multi-element filtration system features a single set of feed ports, permeate outlets, and residue outlets for the multi-element pressure vessel, rather than a set for each filter element. Multi-element filtration systems are widely used in water treatment facilities to purify water and also as reactors in various chemical manufacturing processes. The most commonly used commercial RO system is the multi-element filtration system, which comprises multiple RO elements arranged horizontally in series within a pressure vessel. Figure 1 a). A horizontal system with parallel-placed RO elements ( Figure 1 b) is also known. Similarly, commercial multi-element UF or MF systems may include horizontal elements in series ( Figure 1 a) or parallel vertical elements ( Figure 1 c). Vertical components can also be placed in series. Figure 1 d). Typically, horizontal multi-element UF or MF systems use membranes arranged from the inside out, while vertical multi-element UF or MF systems use membranes arranged from the outside in.

[0010] Attempts have been made to integrate pre-filters with filter elements or systems. Examples of integrating pre-filters into element housings can be seen in JP03193122, JP04338221, and CN218249518, and an example of inserting a pre-filter into the element from the side of the housing can be seen in CN216358934. Examples of integrating screening within a vertical multi-element system can also be seen in KR10-1303993, and an example of integrating a cylindrical pre-filter from below above a vertically arranged filter element can be seen in WO 2016042179.

[0011] However, there is still a need to integrate pre-filters with components that are easy to handle, transport, and install into multi-element systems. This is especially true for UF or MF elements that process raw liquids with relatively high turbidity; integration of pre-filters with elements that can be easily handled, transported, and installed into multi-element systems is essential. Furthermore, the need for simple and effective integration of pre-filters with filter elements or systems is crucial for element installation and cost control of the filtration system. Summary of the Invention

[0012] Therefore, this paper provides a filtering unit, which includes:

[0013] A filter element having at least one filter membrane having a first surface in contact with feed and a second surface in contact with permeate, at least one end of the filter element including an opening to introduce feed into the first surface of the filter membrane; and a central conduit surrounded by the filter membrane to collect permeate; and

[0014] A screening device, preferably connected to an end of a filter element including one or more openings for introducing feed into a first surface of a filter membrane, the screening device including an orifice substantially located at the center of the screening device, an outer ring in the outer periphery of the screening device, and a screen body between the orifice and the outer ring.

[0015] Preferably, the screening device is backwashable. More preferably, the outer ring defines an outer width larger than the width of the filter element.

[0016] The filter membrane may be surrounded by a housing. An outer ring may include an inner surface connected to the housing. The outer ring may further include an outer surface having at least supporting ribs.

[0017] The inner surface of the outer ring is preferably connected to the housing by optional snap-fit ​​devices, corresponding grooves and protrusions, threads, heat welding, pressure welding, adhesive bonding, or other non-limiting methods. Preferably, the inner surface of the outer ring is sealed relative to the housing of the filter element to prevent feed from flowing to the first surface of the filter membrane through a potential gap between the inner surface of the outer ring and the housing.

[0018] The outer ring may further include an outer surface having at least support ribs. Preferably, multiple support ribs are present. The multiple support ribs may be separated into groups, and preferably, the groups of support ribs are placed at uniform intervals. When two or more filter units are placed in a shared container, the support ribs of the outer ring can be used to abut against the inner surface of the container, thereby preventing the filter units from deviating from their desired position. Optionally, the support ribs may be circular O-rings surrounding the outer ring to provide a seal between the outer ring and the inner surface of the container.

[0019] The filter unit may further include two ends, each of which may include an opening through which feed can be introduced onto a first surface of the filter membrane. The filter unit may further include two or more screening devices, which may be positioned on either side of the filter element. Additionally, the feed flow direction of the filter unit may be reversible; that is, feed can be introduced from either side or both sides of the filter element.

[0020] The filter element can be directly connected to the screening device by attaching and fixing the screening device to the filter element. For example, the outer ring of the filter element may include an inner surface connected to the housing.

[0021] The filter unit may further include a connector for guiding permeate collected in a central conduit of the filter element, and may further be equipped with a sealing device. The connector can be connected to both the screening device and the filter element by being inserted through an orifice of the screening device and into the central conduit of the filter element. The sealing device seals between the connector and the central conduit, thereby forming a fluid seal between the feed and the permeate. The connector may further include another sealing device for sealing between the connector and the orifice.

[0022] The filter element can be indirectly connected to the screening device by assembling a connector to connect both the screening device and the filter element separately.

[0023] The filter membrane is selected from the group consisting of: microfiltration membrane, ultrafiltration membrane, nanofiltration membrane, distillation membrane, degassing membrane, ion exchange membrane and reverse osmosis membrane, preferably microfiltration membrane and ultrafiltration membrane.

[0024] The screening device may further include at least two layers of screen body between the orifice and the outer ring. Preferably, the at least two layers of screen body have different screening sizes. When the filter membrane is a UF or MF membrane, the screen body preferably has a screening size between 50 micrometers and 400 micrometers, more preferably between 100 micrometers and 300 micrometers, and even more preferably between 100 micrometers and 150 micrometers.

[0025] A further provision provides a filtration system including a container, an inlet port, a permeate outlet, an optional residual outlet, and one or more filtration units located in series within the container, each of which includes:

[0026] A filter element having at least one filter membrane having a first surface in contact with feed and a second surface in contact with permeate, at least one end of the filter element including an opening to introduce feed into the first surface of the filter membrane; and a central conduit surrounded by the filter membrane to collect permeate; and

[0027] A screening device connected to an end of a filter element including one or more openings for introducing feed into a first surface of a filter membrane; the screening device includes an orifice positioned substantially at the center of the screening device, an outer ring in the outer periphery of the screening device, and a screening body positioned between the orifice and the outer ring.

[0028] Preferably, the screening device is backwashable. More preferably, the outer ring defines an outer width larger than the width of the filter element.

[0029] The filter membrane may be surrounded by a housing. An outer ring may include an inner surface connected to the housing. The outer ring may further include an outer surface having at least supporting ribs.

[0030] In some embodiments, at least two filter units are arranged in series within the container. The first and second filter units are positioned sequentially in the feed flow direction, with the screening device positioned upstream of the filter element in the feed flow direction for the first filter unit and downstream of the filter element for the second filter unit. The feed flow direction of the filtration system can be reversed. Alternatively, the feed can be introduced from either end or both ends of the filtration system. One or more individual membrane elements, with or without an integrated screening device, may be present in series between the two filter units.

[0031] The filter element of the filtration unit within the container may further include two ends. One or both ends may include openings through which feed can be introduced onto a first surface of the filter membrane, and each end of the filter element may be connected to at least one screening device. The filtration system may further include another feed port at opposite ends of the filtration system, and feed can flow to any one or both feed ports of the filtration system. The feed flow direction of the filtration system may be reversible.

[0032] The filter element is preferably directly connected to the screening device by attaching and fixing the screening device to the filter element. For example, the outer ring of the filter element may include an inner surface connected to the housing.

[0033] The filtration unit may further include a connector for guiding permeate collected in the central channel of the filtration element, and is equipped with a sealing device; the connector is connected to both the screening device and the filtration element by inserting it through an orifice of the screening device and into the central channel of the filtration element. The sealing device seals between the connector and the central channel, thereby forming a fluid seal between the feed and the permeate. The connector may further include another sealing device for sealing between the connector and the orifice.

[0034] The filter element can be indirectly connected to the screening device by assembling a connector to connect both the screening device and the filter element separately.

[0035] The outer ring may further include an outer surface. The inner surface of the outer ring is preferably connected to the housing by optionally snap-fit ​​devices, corresponding grooves and protrusions, threads, heat welding, pressure welding, adhesive bonding, and other non-limiting methods. Preferably, the inner surface of the outer ring is sealed relative to the housing of the filter element to prevent feed from flowing to the first surface of the filter membrane through a potential gap between the inner surface of the outer ring and the housing.

[0036] The outer ring may further include an outer surface having at least support ribs. Preferably, multiple support ribs are present. The multiple support ribs may be separated into groups, and preferably, the groups of support ribs are placed at uniform intervals. When the filter unit is placed in a shared container, the support ribs of the outer ring can be used to abut against the inner surface of the container, thereby preventing the filter unit from deviating from the desired position. Optionally, the support ribs may be circular O-rings surrounding the outer ring to provide a seal between the outer ring and the inner surface of the container.

[0037] The outer ring may further include an inner surface that is optionally attached to the housing by snap-fit ​​devices, corresponding grooves and protrusions, threads, heat welding, pressure welding, adhesive bonding, and other non-limiting methods. Preferably, the inner surface of the outer ring is sealed relative to the housing of the filter element to prevent feed from flowing to the first surface of the filter membrane through a potential gap between the inner surface of the outer ring and the housing.

[0038] When the filter element is optionally indirectly connected to the screening device via an assembly connector to separately connect both the screening device and the filter element, the inner surface of the outer ring is not necessarily connected to the housing.

[0039] The connector can be used to guide permeate collected in the central channel of the filter element and can also be equipped with a sealing device. A first connector may be present to connect to only one filter element. A second connector may also be present to connect to two filter elements (i.e., one filter element on each side of the connector). The first and second connectors preferably include sealing devices to seal between the connector and the central channel of the filter element, thereby forming a fluid seal between the feed and the permeate. The first connector may further include another sealing device for sealing between the connector and an orifice. The second connector may further include another sealing device for sealing between the connector and an orifice.

[0040] The filtration membrane is selected from the group consisting of: microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, distillation membranes, degassing membranes, ion exchange membranes, and reverse osmosis membranes, preferably microfiltration membranes and ultrafiltration membranes. The type of membrane is selected independently for each membrane element in the filtration unit.

[0041] The screening device may further include at least two layers of screen body between the orifice and the outer ring. Furthermore, the at least two layers of screen body have different screening sizes. When the filter membrane is a UF or MF membrane, the screen body preferably has a screening size between 50 micrometers and 400 micrometers, more preferably between 100 micrometers and 300 micrometers, and even more preferably between 100 micrometers and 150 micrometers.

[0042] The advantages and features characterizing the novelty of the invention are specifically pointed out in the appended claims and form a part of the claims. However, for a better understanding of the invention, its advantages, and the purposes achievable through its use, reference should be made to the accompanying drawings, which form another part of the invention, and to the accompanying descriptive text, in which one or more preferred embodiments of the invention are shown and described. Attached Figure Description

[0043] Figure 1 a, Figure 1 b and Figure 1 c is a cross-sectional view showing different types of multi-element filtration systems in the prior art.

[0044] Figure 2a , Figure 2b and Figure 2c This is a 3D view showing the filtering unit as described in this article.

[0045] Figure 3 a to Figure 3 d is an elevation view showing the front view of the screening apparatus as described in this article. Figure 3 d is Figure 2b A partial elevation view of the screening device in use, as depicted in the figure.

[0046] Figure 4 a to Figure 4 d is a perspective view showing several connectors as described in this article.

[0047] Figure 5 a to Figure 5 d is a cross-sectional view showing a filtration system with at least one filter unit.

[0048] Figure 6 a and Figure 6 b is a partial view showing a cross-section of a filtration system with at least two filter units as described herein.

[0049] Figure 7 a, Figure 7 b and Figure 7 c is a cross-sectional view showing the existing filtration system in the original feed flow direction, the reverse feed flow direction, and the feed flow from both ends of the filtration system.

[0050] Figure 8 b is a cross-sectional view showing an embodiment of the filtering system as described herein. Figure 8 a is Figure 8 A partial view of the cross-sectional view depicted in b.

[0051] Figure 9 b is a cross-sectional view showing an embodiment of the filtering system as described herein. Figure 9 a is Figure 9 A partial view of the cross-sectional view depicted in b.

[0052] Figure 10 'a' is a cross-sectional view, and Figure 10 b and Figure 10 c is a partial cross-sectional view that shows three additional embodiments of the filtration system as described herein. Detailed Implementation

[0053] Now refer to the accompanying drawings, in which the same reference numerals denote corresponding structures in all views, and especially to Figure 2 and Figure 3 The filter unit 10 includes:

[0054] Filter element 2, which has at least one filter membrane 9 (see Figure 5 The filter membrane has a first surface in contact with the feed and a second surface in contact with the permeate; at least one end 110 of the filter element includes an opening 12 to introduce the feed into the first surface of the filter membrane; and a central conduit 8 surrounded by the filter membrane 9 to collect the permeate; and

[0055] The screening device 21 includes an orifice 23 located substantially in the central portion of the screening device 21, an outer ring 25 in the outer periphery of the screening device 21, and a screen body 22 between the orifice and the outer ring.

[0056] Although not depicted herein, the filter membrane 9 may be potted at one or both ends 110 of the filter element 2 by any suitable material (e.g., a polymeric material). The outer ring 25 includes an inner surface 252 and an outer surface 253. The outer surface preferably includes at least support ribs 251. The support ribs 251 may extend along the feed direction or at least around a portion of the outer periphery of the outer ring 25 to fit into the container 3. Alternatively, one or more support ribs 251 may be arranged in a direction perpendicular to the feed flow, or diagonally in the middle portion between the feed flow direction and its perpendicular line. Preferably, there are multiple support ribs 251 separated into groups, and preferably, the groups of support ribs 251 are placed at relatively uniform intervals. When the filter unit is placed into the shared container 3, the support ribs 251 of the outer ring 25 may be used to abut against the inner surface facing the container 3 (see...). Figure 5 and Figure 9 a). The function of (one or more) support ribs 251 may include, but is not limited to, supporting the filter element 2 and preventing the filter unit 10 from deviating from one or both of the desired or preset position. Alternatively, as Figure 9 a and Figure 9As shown in Figure b, the support rib 251 may include a circular O-ring surrounding the outer periphery of the outer ring 25 to provide a seal between the outer ring 25 and the inner surface of the container 3. Optionally, the container 3 may be a pressure vessel.

[0057] Now for reference Figure 2a Filter membrane 9 ( Figure 5 and Figure 6 The filter element 9 (as shown) may be surrounded by a housing 11. The housing 11 may be a polymer or metal tube, a cylindrical polymer or metal mesh, a spirally wound nonwoven fabric, a wound belt, a combination of two or more of these types of housings, or any other suitable way of surrounding the filter membrane 9. The housing 11 may be permanent or temporary. For example, the housing 11 may be dissolved in water and washed away after the filter element 2 has been put into operation.

[0058] Alternatively, the filter element 2 may not be equipped with a housing 11. In such a configuration (not depicted), an outer ring 25 is disposed on one end 110 of the filter element 2. When the filter element 2 is installed in a common container 3, one or more support ribs 251 on the outer surface 253 of the outer ring 25 form a fluid-impermeable seal between the outer ring 25 and the inner surface of the container; in another embodiment, the support ribs 251 facilitate the creation of space for bypass flow between the filter element 2 and the inner surface of the container 3.

[0059] The inner surface 252 of the outer ring 25 can be connected to the housing 11 by optional snap-fit ​​devices, corresponding grooves and protrusions, threads, heat welding, pressure welding, adhesive bonding, a combination of two or more of these methods, or other non-limiting means. Preferably, the inner surface 252 of the outer ring 25 is sealed relative to the housing 11 of the filter element 2 to prevent feed from flowing to the first surface of the filter membrane 9 through the potential gap between the inner surface 252 of the outer ring 25 and the housing 11. Figure 8 An example of this configuration is depicted in section a.

[0060] Now for reference Figure 3 The screening device 21 includes an orifice 23 substantially located at the center of the screening device 21, an outer ring 25 disposed along the outer periphery of the screening device 21, and a screen body 22 between the orifice and the outer ring. Feed flows through the screen body 22 and enters an opening 12 in one end 110 of the filter element 2 (see [link to filter element 2]). Figure 2cThe filter element 2 (without the attached screening device 21) is depicted, and then reaches the first surface of the filter membrane 9. For example, a general description of the filter membrane and its operation is presented in RW Baker's "Membrane Technology and Applications," 3rd edition, John Wiley & Sons, Ltd. (Hoboken, NJ, 2012) (hereinafter referred to as "Baker"). In short, a portion of the feed, as permeate, passes from the first surface through the filter membrane 9 to the second surface. The permeate is collected in a central conduit 8. Preferably, the size of the inner diameter of the orifice 23 is appropriately determined to facilitate the extraction of the permeate already collected in the central conduit 8. For example, in some configurations (not depicted), the central conduit 8 may extend through the orifice 23; in other configurations, connectors 261, 262 may extend through the orifice 23, for example, as shown in... Figure 2a As depicted, the remainder of the feed does not pass through filter membrane 9; instead, the remainder of the feed becomes a permeate stream containing filter material. The permeate stream can be discharged as waste. Alternatively, the permeate stream can undergo one or more other purification methods, or the permeate stream can be recycled through filter element 2, alone or in combination with another fluid, to generate a new feed stream.

[0061] The screen body 22 may include a coarse sieve (low mesh count) to remove large particles that may damage or clog the filter membrane 9 in the filter element 2. Alternatively, the screen body 22 may include a fine sieve (high mesh count) to remove larger and smaller particles from the feed material. A suitable range for the mesh size is 10 μm to 1000 μm, but smaller or larger sizes may be suitable. Those skilled in the art can determine a suitable mesh count(s) based on the size(s) of the material(s) to be filtered from the feed stream. Ideally, a seal (not shown) is present around the orifice 23 to prevent feed material from flowing into the filter element 2 through the space surrounding the orifice 23. The orifice 23 is preferably located at the center of the screening device 21. Figure 2a and Figure 3 As shown in Figure a, the periphery of the screen body 22 includes an outer ring 25, which fixes the screen body 22 in a position within the feed flow upstream of (one or more) filter elements 2 (i.e., before the feed flow enters (one or more) filter elements 2). It should also be noted that the screening device 21 may consist of only a single component ( Figure 3 a, Figure 3 b), or the screening device may include several parts connected or held together. Figure 3 c).

[0062] like Figure 2a as well as Figure 3 b、 Figure 3c and Figure 3 As shown in d, the screening device 21 may further include a support beam 24 in the region of the screen body 22, which serves as a reinforcing member to strengthen the screening device 21, or as... Figure 3 As shown in c, this is a combination of several parts used to form the screening device 21. The different parts of the screening device 21 can be formed into a single piece by the action of adhesives, by tongue and groove construction, by snap-fit ​​devices, or by other connection methods (not shown). Preferably, the polymer portion of the screening device 21 is formed into a single piece and combined with other parts made of non-polymer materials in a suitable manner. For example, the screening device 21 can be formed into a single piece by injection molding, by other types of molding, or by 3D printing as one or more parts.

[0063] The screening device 21 may include one or more organic materials, one or more inorganic materials, or a combination of one or more organic materials and one or more inorganic materials. Organic materials suitable for the screening device 21 include, but are not limited to, any suitable polymer, such as polyolefins (including fluorinated polyolefins), polyamides, polyacrylates, polyesters, and copolyesters (such as Tritanium). TM (Available from Eastman Chemical Co., Kingsport, Tennessee)), polysulfone (PS), polyethersulfone (PES), sulfonated polyethersulfone (SPS), cellulose, polycarbonate (PC), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), fluorinated ethylene polymer (FEP), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), polyacrylonitrile (PAN), acrylonitrile-butadiene-styrene (ABS), and combinations of two or more of these polymers. Inorganic materials suitable for the screening device 21 include, but are not limited to, metals (e.g., stainless steel), ceramic components (e.g., alumina, zirconium oxide, silicon oxide, etc.), and combinations of two or more of these materials. Preferably, the orifice 23, the support beam 24, and the surrounding material of the outer ring 25 are made of organic material. Preferably, the screen body 22 is made of inorganic material.

[0064] The Baker referenced above describes a filter membrane 9 suitable for the filtration unit described herein. In short, the filter membrane 9 may include one or more of the following types: microfiltration membrane, ultrafiltration membrane, nanofiltration membrane, distillation membrane, degassing membrane, ion exchange membrane, and reverse osmosis membrane. Preferably, the filter membrane 9 is selected from microfiltration and ultrafiltration membranes. The filter membrane 9 may contain organic or inorganic materials or a combination of both. Organic materials suitable for the filter membrane 9 include, but are not limited to, any suitable polymer, such as polyolefins (including fluorinated polyolefins), polyamides, polyacrylates, polyesters, copolyesters (including Tritanium) TMInorganic materials suitable for the filter membrane 9 include, but are not limited to, ceramic membranes made from any suitable material (e.g., alumina, zirconium oxide, silica, etc., and combinations of two or more of these materials). The ceramic membrane can be synthesized by sintering, sol-gel, phase separation, vapor deposition, or another suitable method known in the art. The filter membrane 9 can have any suitable shape, such as hollow fiber, tube, porous fiber, knitted fiber, spiral sheet, pleated sheet, and flat sheet. In elements having more than one membrane 9, the membranes can be the same or different.

[0065] Now for reference Figure 2c One or both ends 110 of the filter element 2 include one or more openings 12 to introduce feed into the first surface of the filter membrane 9. (Reference) Figure 5 b and Figure 5 c. The filter unit 10 may include two or more screening devices 21, 21' at both ends 110 of the filter element(s) 2. As discussed above, one or more screening devices 21, 21' may be located at a single end 110 of the filter element 2, such as... Figure 5 a and Figure 5 As depicted in c. Alternatively, each end 110 of the filter element 2 may be connected to at least one screening device 21, 21', as described in c. Figure 5 b and Figure 5 As depicted in d, two or more screening devices 21, 21' can be placed together in parallel alignment through orifices 23, as shown in the image. Figure 6 As depicted in b. Two or more screening devices 21, 21' may be identical, or they may have different screening sizes, material types, or shapes. The feed flow direction of the filter unit 10 may be reversed. Alternatively, the feed may be introduced from either side or both sides of the filter unit 10.

[0066] The filter element 2 is preferably directly connected to the screening device 21 by attaching and fixing the screening device 21 to the filter element 2 (e.g., by fixing the outer ring 25 to the housing 11), as depicted in FIG2. Referring now to... Figure 4 For example, suitable connectors 261, 262 can be used to guide the permeate collected in the central pipe 8 of the filter element 2 to the next filter unit 10 in series or to the permeate outlet 5, such as Figure 1As shown. Alternatively, the filter unit 10 can use connectors 261, 262 to connect both the filter element 2 and the screening device 21, such that by assembling connectors 261, 262 to connect the screening device 21 and the filter element 2 separately, the filter element 2 is indirectly connected to the screening device 21, whose outer ring 25 is not directly connected to the housing 11 of the filter element 2. This configuration is... Figure 9 As shown in the image.

[0067] like Figure 4 As shown, connectors 261 and 262 can be hollow tubes with a hollow chamber 28. Connectors 261 and 262 guide permeate collected in the central conduit 8 of the filter element 2 and are equipped with at least one sealing device 27. Any suitable sealing device 27 can be used. Preferably, the sealing device forms a fluid-impermeable seal. For example, in Figure 4 a to Figure 4 d depicts two or more O-rings, preferably deformable or elastic O-rings. More preferably, the O-rings are positioned such that when connectors 261, 262 are attached to the central conduit 8, the O-rings remain in place on the connector. Connectors 261, 262 are connected to both the screening device 21 and the filter element 2 by insertion through the orifice 23 of the screening device 21 and into the central conduit 8 of the filter element 2. In this preferred configuration, a sealing device 27 seals between connectors 261, 262 and the central conduit 8, thereby forming a fluid seal between the feed and the permeate. The first type of connector 261 has a sealing device 27 at one end. Figure 4 b、 Figure 4 d) to connect to and seal with only one filter membrane 2. The second type of connector 262 has sealing devices 27 at both ends. Figure 4 a, Figure 4 c) and each end of connector 262 is connected to and sealed to a filter membrane 2. Connectors 261, 262 may further include a protruding base 29 for aligning with and / or resting on the screening device 21. This protruding base 29 also allows for a constant spacing between adjacent filter elements 2 on either side of the protruding base 29. The first connector 261 may further include additional portions or additional portions connected to the filtration system 1, such as... Figure 8 a and Figure 9 The cover 31 is shown in figure a. Connectors 261, 262 may further include another sealing device (not shown) for sealing between connectors 261, 262 and orifice 23.

[0068] Now for reference Figure 5 and Figure 6The first connector 261 is connected to the filter element 2 by inserting its end, which has a sealing device 27, into the central pipe 8 of the filter element 2. In this preferred configuration, the sealing device 27 forms a fluid seal between the feed and the permeate, i.e., a gas or liquid impermeable seal. The first connector 261 is connected to the screening device 21 by inserting one end of the first connector 261 through the orifice 23 of the screening device 21. Figure 5 a and Figure 5 As shown in diagram b, the filter element 2 can be indirectly connected to the screening device 21 via a first connector 261, which can be individually connected to each of the screening device 21 and the filter element 2. In this configuration, the outer ring 25 is not directly connected to the housing 11 of the filter element 2 (as shown in diagram b). Figure 9 (as depicted in a), and the first connector 261 also helps to guide the permeate collected in the central conduit 8 to, for example, another step in the purification process or to a storage container. Figure 5 c and Figure 5 As shown in d, the filtration system 1, which has a direct connection between the filter element 2 and the screening device 21 (depicted as the orthogonal portion of the screening device 21), may also include a first connector 261 to guide the permeate collected in the central pipe 8 of the filter element 2 to, for example, another step in the purification process or to a storage container.

[0069] Alternatively, in the absence of the first connector 261, the filter element 2 includes a protrusion (not shown) adapted to be connected to the screening device 21 by inserting the protrusion into an orifice 23 passing through the screening device 21.

[0070] Now for reference Figure 5 (a) to Figure 5 (d) This document further provides a filtration system 1, which includes a container 3 and at least one filtration unit 10 as described herein (e.g., shown in FIG. 2) within the container 3. The container 3 has multiple ports at its two ends 112, including a feed port 4, a permeate outlet 5, and optionally a residual permeate outlet 6. The system includes the filtration unit 10, which comprises:

[0071] Filter element 2, having at least one filter membrane 9 having a first surface in contact with the feed and a second surface in contact with the permeate, and at least one end 110 of filter element 2 including an opening 12. Figure 2c (As shown), to introduce feed into the first surface of the filter membrane; and a central conduit 8, which is surrounded by one or more filter membranes 9 to collect permeate; and

[0072] Screening device 21, which is connected to the end 110 of filter element 2, the end including one or more openings 12 to introduce feed into the first surface of filter membrane(s) 9;

[0073] The screening device 21 includes an orifice 23 located substantially in the central part of the screening device 21, an outer ring 25 disposed along the outer periphery of the screening device 21, and a screen body 22 disposed between the orifice 23 and the outer ring 25.

[0074] In some preferred configurations, at least one filter unit 10 is located at the outermost edge of the feed side of the filter system 1, and the screening device 21 of one filter unit 10 is located upstream of the filter element 2 in the feed flow direction.

[0075] The screening device 21 may include at least two layers of screen bodies 22 between the orifice 23 and the outer ring 25, wherein these layers of screen bodies 22 have the same or different screening sizes. When the filter membrane is a UF or MF membrane, the screen body 22 preferably has a screening size between 50 micrometers and 400 micrometers, more preferably between 100 micrometers and 300 micrometers, and even more preferably between 100 micrometers and 150 micrometers.

[0076] To reduce the physical footprint of the filtration system, it is known to place at least two filter units 10 inside the container 3, such as... Figure 1 a to Figure 1 As shown in d. Clearly, Figure 1 a to Figure 1 The configuration shown in d is also well applicable to the filter unit and filter system provided herein. For example, filter unit 10 can be in the horizontal direction (e.g., Figure 1 a and Figure 1 (as shown in b) or in the vertical direction (e.g.) Figure 1 c and Figure 1 (As shown in d) Serial positioning. Preferably, there is an air intake port 7 for the vertical system, such as... Figure 1 c and Figure 1 As shown in d. Preferably, the filter units 10 are positioned in series in the horizontal direction, as shown in Figure d. Figure 1 a is shown. Figure 1 a to Figure 1 d also depicts the feed inlet 4, permeate outlet 5, and residual permeate outlet 6.

[0077] like Figure 6 , Figure 8 b and Figure 9As shown in b, at least two filter units 10 can be arranged in series in the horizontal direction within the container 3. Preferably, at least one screening device 21 is positioned before the feed inlet 4 of the first filter unit 10 (configuration not shown). Alternatively, the screening device 21 can be positioned upstream of the first filter unit 10 in the feed flow direction. For example, in Figure 8 In step b, the screening device 21 is positioned before each filter unit 10 in the feed flow direction. Figure 9 In step b, the screening device 21 is positioned before the first filter unit 10 in the filtration system 1, and another screening device 21' is positioned after the last filter unit 10. Similarly, the filter units are arranged in the direction of the feed flow. Clearly, in this respect, the direction of the feed flow in the filtration system 1 is reversible. That is, as... Figure 7 As described, during one operating period, feed can be introduced from feed port 4, and then during another operating period, feed can be introduced in reverse and from feed port 4'. Alternatively, feed can be introduced from either side or both sides of the filtration system 1, for example, from either or both of feed ports 4 and 4'.

[0078] Now for reference Figure 6 b. The first connector 261 is connected to the feed inlet 4, and the second connector 262 is connected to the two filter elements 2, 2'. Each end of the second connector 262 is connected to a filter element 2 by inserting an end 27 with a sealing device into the central conduit 8 of the filter element 2, 2'. The sealing device 27 preferably forms a fluid seal between the feed and the permeate within the filtration system 1, i.e., a gas or liquid impermeable seal. In some preferred configurations, for example... Figure 6 In the configuration shown in b, the second connector 262 is connected to the two screening devices 21, 21'. In this preferred configuration, each end of the second connector 262 is connected to the screening devices 21, 21' by inserting one end of the second connector 262 into the orifices 23, 23' passing through each screening device 21, 21'.

[0079] exist Figure 9 In the filtration system 1 described in b, one or more individual filter elements 2”, 2”' can be positioned in series between two filter units 10, 10'. The filtration system 1 further includes two or more second connectors 262 to connect adjacent pairs of membrane elements 2, 2', 2”, 2”'. In addition, in this configuration, the filter elements 2, 2' of the filter units 10, 10' are indirectly connected to the screening devices 21, 21' via assembly connectors 261, 261' to connect both the screening devices 21, 21' and the filter elements 2, 2' (optionally, they can be connected one after another or separately). Figure 9The partial view shown in Figure a cross-section reveals the outer ring 25, the outer surface 253 of the outer ring, and at least one support rib 251, which is depicted herein as a circular protrusion or O-ring extending around the outer circumference of the outer ring 25 to seal between the outer ring 25 and the inner surface of the container 3.

[0080] Refer again Figure 8 b. In an alternative configuration of the filtration system 1, two or more filter units 10, 10', 10”, 10”' are positioned in series, each filter unit 10, 10', 10”, 10”' includes two or more screening devices 21, 21', 21”, 21”', and each end 110 of each filter element 2, 2', 2”, 2”' is connected to at least one screening device 21, 21', 21”, 21”'. In this configuration, the filtration system 1 further includes a second connector 262 for connecting every two adjacent filter units 10, 10', 10”, 10”'. Optionally, the filter units 10, 10', 10”' are directly connected to the screening devices 21, 21'. Figure 8 As shown in diagram a, the inner surface 252 of the outer ring 25 of the screening device 21' is connected to the housing 11, for example, by optional snap-fit ​​devices, corresponding grooves and protrusions, threads, heat welding, pressure welding, adhesive bonding, another suitable method known in the art, or a combination of two or more of these methods. When the screening device 21 is directly fixed to the housing 11 of the filter element 2, the filter unit 10 can be conveniently transported and installed as a single unit without the need for separate management of the filter element 2 and the screening device 21. Preferably, the inner surface 252 of the outer ring 25 is sealed relative to the housing 11 of the filter element 2 with a fluid-impermeable seal to prevent feed from flowing between the inner surface of the outer ring 25 and the housing 11 to the first surface of the filter membrane 9. Figure 8 In a, the fluid-impermeable seal 26 is depicted as a circular protrusion along the inner circumference of the outer ring 25.

[0081] Now for reference Figure 10 a, describes something similar to Figure 5 The filtration system 1 described in d differs in that it has two screening devices 21, 21' at each end 115, 115' of the system. Figure 10 In b, a description similar to Figure 6 The filtration system 1 shown in diagram a differs in that it has two screening devices 21, 21' at the depicted end 115 of the system. Figure 10 In c, a description similar to Figure 6 The filtration system 1 shown in b differs in that it has two screening devices 21, 21' at the depicted end 115 of the system.

[0082] The filter membrane 9 is selected from the group consisting of MF membranes, UF membranes, NF membranes, distillation membranes, degassing membranes, ion exchange membranes, and RO membranes. The type of membrane is selected independently for each filtration unit. In other words, the filtration unit may include the same type or different types of filter membranes. Preferably, the filter membrane 9 is selected from MF membranes and UF membranes. Normal cleaning processes for UF and MF membranes include backwashing, air rinsing, chemically enhanced backwashing (CEB), in-situ cleaning (CIP), and other methods known to those skilled in the art. The most commonly used cleaning process is backwashing, which is typically performed every 20 to 60 minutes based on feed conditions. Using the filter unit 10 and filtration system 1 described herein, when cleaning (e.g., backwashing) is applied to clean the MF membrane and / or UF membrane, the same cleaning process is simultaneously applied to the screening device 21. Therefore, no separate cleaning step or additional cleaning agent is required to clean the screening device 21 and the filter element 2, which greatly reduces maintenance time and costs and significantly improves operational efficiency. Furthermore, the filter element 2 described herein embodies a one-control philosophy for the filter unit 10, which includes both the screening device 21 and the filter element 2. The term "one-control philosophy" refers to a system that can operate in the same way as a system that only includes UF capability without requiring additional operational changes.

[0083] In a multi-element filtration system 1, the filter membranes 9 of different filter elements 2 can have the same or different materials, pore sizes, morphologies, sizes, and shapes. Different filter elements 2 in the filtration system 1 can have the same or different configurations, membranes, membrane areas, etc. For example, ... Figure 6 As shown, the pore size of the filter membrane 9' in the downstream filter element 2” can be larger or smaller than the pore size of the filter membrane 9 in the upstream filter element 2.

[0084] Now for reference Figure 7 a, Figure 7 b and Figure 7 c. Importantly, these figures illustrate filtration systems known in the art. However, the construction of filter systems designed for reverse-feed flow is equally applicable to the filter elements and filtration systems described herein, such as... Figure 8 b and Figure 9 Those described in b. In these configurations, the feed flow direction of the filter unit 10 and the filter system 1 is reversible. Equally important, reversing the flow in this way is a mechanism for backwashing (one or more) of the screening devices 21. Figure 7 As shown in Figure a, the filtration system 1 includes: a container 3, with multiple ports at both ends 112, including a feed port 4, a permeate outlet 5, and optionally a residual permeate outlet 6; a first filtration unit 10; and at least a second filtration unit 10'. When the feed flow is... Figure 7When the flow direction in a is reversed compared to when the flow direction in filter system 1 is reversed, the filter system 1... Figure 7 The configuration described in b, wherein the filtration system 1 includes: a container 3, the two ends 112 of which have multiple ports, including a feed port 4' (which is located in... Figure 7 In the configuration described by a, it is used as the residue outlet 6) and residue outlet 6' (which is in Figure 7 In the configuration described, 4 is used as the feed port and 5 as the permeate outlet (which is maintained in...). Figure 7 (The configuration described in a has the same function); a first filter unit 10; and at least a second filter unit 10'. Figure 7 As shown in diagram c, in another configuration, the filtration system 1 includes: a container 3, with multiple ports at both ends 112 of the container 3, including feed ports 4, 4', permeate outlet 5, and residue outlet 6; and at least two filter units 10, 10'. In this configuration, feed is introduced from both sides of the filtration system 1 through the feed ports 4, 4'. The permeate outlet 5 may also be located at one or both ends 115 of the filtration system 1; alternatively, a plug 30 may be inserted into one end of the central conduit 8 to seal between the permeate and the feed or residue, such as... Figure 5 a and Figure 5 As shown in c.

[0085] like Figure 8 and Figure 9 As shown, the outer ring 25 may preferably have an inner diameter larger than the outer diameter of the filter element 2. In the depicted configuration, the outer ring 25, directly or indirectly connected to the filter element 2, establishes a gap between the filter element 2 and the container 3. In some configurations, this gap can prevent the contents of the filter element 2 from being pumped into the container 3. Figure 8 In the preferred configuration shown, a gap also exists between the outer ring 25 and the inner surface of the container 3. This gap may prevent the screening device 21 from expanding and pressing against the container 3, which could potentially deform and damage other seals or connections in the system. Such undesirable expansion could be a result of exposure to solvents or overheating.

[0086] While certain preferred embodiments of the invention have been described and specifically illustrated above, the invention is not intended to be limited to such embodiments. Rather, it should be understood that although many features and advantages of the invention, together with details of its structure and function, have been set forth in the foregoing description, this disclosure is merely illustrative and may be made in detail, particularly in terms of the shape, size, and arrangement of the parts, to the full extent indicated by the broad, general meaning of the terms in the appended claims, within the principles of the invention.

[0087] Figure Labels

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[0089]

Claims

1. A filtering unit, the filtering unit comprising: A filter element comprising at least one filter membrane having a first surface for contacting a feed and a second surface for contacting a permeate; The filter element includes at least one end with one or more openings to introduce feed into a first surface of the filter membrane; and the filter element further includes a central conduit surrounded by the filter membrane to collect permeate; and a screening device connected to the end of the filter element including the one or more openings. The screening device includes an orifice positioned substantially at the center of the screening device, an outer ring positioned along the outer periphery of the screening device, and a screen body disposed between the orifice and the outer ring, and optionally, the outer ring defines an outer width larger than the width of the filter element.

2. The filtering unit as claimed in claim 1, wherein, The outer ring includes an outer surface, and the outer surface includes at least a supporting ridge.

3. The filtering unit as described in claim 1 or claim 2, wherein, The filter membrane is surrounded by a housing; the outer ring includes an inner surface; and the inner surface is connected to the housing.

4. The filter unit as described in any one of claims 1, 2, or 3, wherein, The filter element includes two ends, and the two ends include openings through which the feed can be introduced into a first surface of the filter membrane; wherein the filter unit includes two or more screening devices; and wherein each end of the filter element is connected to at least one screening device.

5. The filtering unit as described in any of the preceding claims, wherein, The feed flow direction of the filter unit is reversible.

6. The filter unit as claimed in any of the preceding claims, further comprising a first connector for guiding permeate collected in the central conduit of the filter element; wherein, The first connector is equipped with a sealing device; wherein the first connector is connected to both the screening device and the filter element by being inserted through an orifice of the screening device and into a central pipe of the filter element; and wherein the sealing device seals between the first connector and the central pipe, thereby forming a fluid seal between the feed and the permeate.

7. The filtering unit as claimed in claim 6, wherein, The first connector further includes a second sealing device for sealing between the first connector and the orifice.

8. The filtering unit as described in any of the preceding claims, wherein, The inner surface of the outer ring abuts against the housing of the filter element and is sealed.

9. The filtering unit as described in any of the preceding claims, wherein, The screening device includes at least two layers of screen body.

10. The filtering unit as described in any of the preceding claims, wherein, The at least two layers of screen body have different screening sizes.

11. The filtering unit as described in any of the preceding claims, wherein, At least one layer of the screen body has a sieve size between 50 micrometers and 400 micrometers.

12. The filtering unit as described in any of the preceding claims, wherein, At least one layer of the screen body has a sieve size between 100 micrometers and 300 micrometers.

13. The filtering unit as described in any of the preceding claims, wherein, The filtration membrane is selected from the group consisting of: reverse osmosis membranes, nanofiltration membranes, ultrafiltration membranes, microfiltration membranes, electrodialysis membranes, distillation membranes, degassing membranes, ion exchange membranes, and combinations of two or more of these membranes; preferably, the filtration membrane is selected from the group consisting of: microfiltration membranes, ultrafiltration membranes, and both microfiltration membranes and ultrafiltration membranes.

14. The filtering unit as described in any of the preceding claims, wherein, The screening device is backwashable.

15. A filtration system comprising a container having two ends, wherein, At least one of the two side ends is provided with a plurality of ports, including one or more of a feed port, a permeate outlet and an optional residual outlet, and wherein at least one filter unit as described in any of the preceding claims is placed within the container.

16. The filtration system of claim 15, wherein the filtration system comprises at least two filtration units, wherein, A screening device in a filtration unit is positioned close to each end of the filtration system.

17. The filtration system of claim 15 or claim 16, wherein the filtration system comprises at least two inlet ports, wherein, At least two of the feed ports are located at different ends of the filtration system, and the feed flows to at least two feed ports at different ends of the filtration system.

18. The filtration system of claim 15, 16, or 17, wherein, The feed flow direction of the filtration system is reversible.

19. The filtration system as claimed in any one of claims 15 to 18, wherein, The outer ring includes an outer surface, which includes at least a supporting ridge to abut against the inner surface of the container.

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