Disclosure of Invention
Accordingly, provided herein is a filtration unit comprising:
a filter element having at least one filter membrane with a first surface contacting the feed and a second surface contacting the permeate, at least one end of the filter element including an opening to introduce the feed to the first surface of the filter membrane, and a central conduit surrounded by the filter membrane to collect the permeate, and
A screening device, preferably connected to an end of the filter element comprising one or more openings for introducing feed to the first surface of the filter membrane, the screening device comprising an aperture positioned substantially in the centre of the screening device, an outer ring in the outer periphery of the screening device, and a screen body between the aperture and the outer ring.
The filter membrane may be surrounded by a housing. The outer ring may include an inner surface connected to the housing. The outer ring may further comprise an outer surface having at least support ribs.
The inner surface of the outer ring is preferably connected to the housing by optional snap means, corresponding grooves and protrusions, threads, heat welding, pressure welding, gluing or other non-limiting means. Preferably, the inner surface of the outer ring is sealed against the housing of the filter element to avoid feed from flowing between the potential gap between the inner surface of the outer ring and the housing to the first surface of the filter membrane.
The outer ring may further comprise an outer surface having at least support ribs. Preferably, there are a plurality of support ribs. The plurality of support ribs may be separated into groups, and preferably, the groups of support ribs are placed at uniform intervals. The support ribs of the outer ring may be adapted to abut against the inner surface facing the container when the filter units are placed in a common container, thereby preventing the filter units from deviating from the desired position. Alternatively, the support rib may be a circular O-ring around the outer ring to seal between the outer ring and the inner surface of the container.
The filtration unit may further comprise two ends, and each of the two ends may comprise an opening through which feed may be introduced to the first surface of the filtration membrane. The filter unit may further comprise two or more screening devices, and the screening devices may be placed on both sides of the filter element. In addition, the feed flow direction of the filtration unit may be reversible. That is, the feed may be introduced from either or both sides of the filter element.
The filter element may be directly connected to the screening device by attaching and securing the screening device to the filter element, e.g. the outer ring of the filter element may comprise an inner surface connected to the housing.
The filter unit may further comprise a connector for guiding permeate collected in the central duct of the filter element, and may further be provided with sealing means. The connector may be connected to both the screening device and the filter element by being inserted through an aperture of the screening device and into a central conduit of the filter element. The sealing means seals between the connector and the central conduit, thereby forming a fluid seal between the feed and permeate. The connector may further comprise further sealing means for sealing between the connector and the aperture.
The filter element may be indirectly connected to the screening device by fitting a connector to connect both the screening device and the filter element separately.
The filtration 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.
The screening device may further comprise at least two layers of screen bodies between the apertures and the outer ring. Preferably, the screen bodies of at least two layers have different screening sizes. When the filter membrane is a UF or MF membrane, the screen body preferably has a screening size of between 50 and 400 microns, more preferably between 100 and 300 microns, still more preferably between 100 and 150 microns.
There is further provided a filtration system comprising a vessel, a feed port, a permeate outlet, optionally a retentate outlet, and at least two filtration units described herein positioned in series within the vessel, each of these filtration units comprising:
A filter element having at least one filter membrane with a first surface contacting the feed and a second surface contacting the permeate, at least one end of the filter element including an opening to introduce the feed to the first surface of the filter membrane, and a central conduit surrounded by the filter membrane to collect the permeate, and
The apparatus includes a filter element having a first surface, a second surface, a screen connected to the first surface, and a screen connected to the second surface, the screen including one or more openings for introducing feed to the first surface of the filter membrane, the screen including an aperture positioned substantially in a center of the screen, an outer ring in an outer periphery of the screen, and a screen body positioned between the aperture and the outer ring.
The filter membrane may be surrounded by a housing. The outer ring may include an inner surface connected to the housing. The outer ring may further comprise an outer surface having at least support ribs.
In some embodiments, at least two filtration units are placed in series within the vessel. The first and second filter units are positioned in this order in the feed flow direction and for the first filter unit the screening device is positioned in front of the filter element in the feed flow direction and for the second filter unit the screening device is positioned downstream of the filter element in the feed flow direction. The feed flow direction of the filtration system may be reversible. Alternatively, the feed may be introduced from either or both ends of the filtration system. There may be one or more individual membrane elements positioned in series between the two filtration units without an integrated screening device.
The filter element of the filter unit within the vessel may further comprise two ends, and both ends may comprise openings, the feed may be introduced to the first surface of the filter membrane via the openings, and each end of the filter element may be connected to at least one screening device. The filtration system may further comprise another feed port at an opposite end of the filtration system, and feed may flow to either or both feed ports of the filtration system. The feed flow direction of the filtration system may be reversible. Alternatively, the feed may be introduced from either or both sides of the filtration system.
The filter element is preferably directly connected to the screening device by attaching and securing the screening device to the filter element, e.g. the outer ring of the filter element may comprise an inner surface connected to the housing.
The filter unit may further comprise a connector for guiding permeate collected in the central duct of the filter element and provided with sealing means, and the connector is connected to both the screening device and the filter element by inserting it through an aperture of the screening device and into the central duct of the filter element. The sealing means seals between the connector and the central conduit, thereby forming a fluid seal between the feed and permeate. The connector may further comprise further sealing means for sealing between the connector and the aperture.
The filter element may be indirectly connected to the screening device by fitting a connector to connect both the screening device and the filter element separately.
The outer ring may further comprise an outer surface. The inner surface of the outer ring is preferably connected to the housing by optional snap means, corresponding grooves and protrusions, threads, heat welding, pressure welding, gluing and other non-limiting means. Preferably, the inner surface of the outer ring is sealed against the housing of the filter element to avoid feed from flowing between the potential gap between the inner surface of the outer ring and the housing to the first surface of the filter membrane.
The outer ring may further comprise an outer surface having at least support ribs. Preferably, there are a plurality of support ribs. The plurality of support ribs may be separated into groups, and preferably, the groups of support ribs are placed at uniform intervals. The support ribs of the outer ring may be adapted to abut against the inner surface facing the container when the filter units are placed in a common container, thereby preventing the filter units from deviating from the desired position. Alternatively, the support rib may be a circular O-ring around the outer ring to seal between the outer ring and the inner surface of the container.
The outer ring may further comprise an inner surface that is connected to the housing by optional snap means, corresponding grooves and protrusions, threads, heat welding, pressure welding, gluing and other non-limiting means. Preferably, the inner surface of the outer ring is sealed against the housing of the filter element to avoid feed from flowing between the potential gap between the inner surface of the outer ring and the housing to the first surface of the filter membrane.
When the filter element is indirectly connected to the screening device, optionally by fitting a connector to connect both the screening device and the filter element separately, the inner surface of the outer ring is not necessarily connected to the housing.
The connector may be used to guide permeate collected in the central tube of the filter element and may also be equipped with sealing means. There may be a first connector connected to only one filter element. There may also be a second connector connected to two filter elements (i.e., one filter element on each side of the connector). The first connector and the second connector preferably comprise sealing means to seal between the connectors and the central conduit of the filter element, thereby forming a fluid seal between the feed and permeate. The first connector may further comprise further sealing means for sealing between the connector and the aperture. The second connector may further comprise further sealing means for sealing between the connector and the aperture.
The filtration 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. The type of membrane is independently selected for each membrane element in the filtration unit.
The screening device may further comprise at least two layers of screen bodies between the apertures and the outer ring. And, the screen bodies of at least two layers have different screening sizes. When the filter membrane is a UF or MF membrane, the screen body preferably has a screening size of between 50 and 400 microns, more preferably between 100 and 300 microns, still more preferably between 100 and 150 microns.
The advantages and features of novelty characterizing the present invention are pointed out with particularity in the appended claims and form a part of the claims. For a better understanding of the invention, however, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to accompanying descriptive matter, in which there are illustrated and described one or more preferred embodiments of the invention.
Detailed Description
Referring now to the drawings in which like reference numerals designate corresponding structure throughout the several views, and in particular to fig. 2 and 3, a filter unit 10 includes:
A filter element 2 having at least one filter membrane 9 (see fig. 5) with a first surface contacting the feed and a second surface contacting the permeate, at least one end 110 of the filter element comprising an opening 12 to introduce the feed to the first surface of the filter membrane, and a central conduit 8 surrounded by the filter membrane 9 to collect the permeate;
A screening device 21 comprising an aperture 23 positioned substantially in a central portion of the screening device 21, an outer ring 25 in an outer periphery of the screening device 21, and a screen body 22 between the aperture and the outer ring.
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 rib 251 may extend in the feed direction or at least around a portion of the outer periphery of the outer ring 25. Preferably, there are a plurality of support ribs 251 separated into groups, and preferably, the groups of support ribs 251 are placed at relatively uniform intervals. The support ribs 251 of the outer ring 25 may be used to abut against an inner surface facing the container 3 (see fig. 5) when placing the filter units into a common container 3, thereby preventing the filter unit 10 from deviating from a desired or preset position. Alternatively, the support rib 251 may include a circular O-ring around the outer periphery of the outer ring 25 to seal between the outer ring 25 and the inner surface of the container 3.
The filter membrane 9 may be surrounded by a housing 11. The housing 11 may be a polymer or metal tube, a cylindrical polymer or metal mesh, a spiral wound nonwoven fabric, a wound tape, two or more of these types of housings, or any other suitable means of enclosing the filtering 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 is put into operation.
Alternatively, the filter element 2 may not be equipped with the housing 11. An outer ring 25 is provided on one end of the filter element 2. When the filter element 2 is mounted in the common container 3, the support ribs 251 on the outer surface 253 of the outer ring 25 in one embodiment help to seal between the outer ring 25 and the inner surface of the container, and in another embodiment the support ribs 251 help to create space for bypass flow between the filter element 2 and the inner surface of the container 3.
The inner surface 252 of the outer ring 25 may be attached to the housing 11 by alternative snap means, corresponding grooves and protrusions, threads, heat welding, pressure welding, gluing, 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 against the housing 11 of the filter element 2 to avoid feed from flowing to the first surface of the filter membrane 9 between the potential gap between the inner surface 252 of the outer ring 25 and the housing 11.
The screening device 21 comprises an aperture 23 positioned substantially in the centre 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 aperture and the outer ring. The feed flows through the screen body 22, into the opening 12 in one end of the filter element 2, and then to the first surface of the filter membrane 9. A portion of the feed passes through the filter membrane 9 as permeate to the second surface of the filter membrane 9. The remainder of the feed is a retentate stream containing filter material. The screen body 22 may be a coarse screen (low mesh number) to remove large particles that may damage or clog the filter membrane 9 in the filter element 2. Alternatively, the screen body 22 may be a fine screen (high mesh) to remove larger and smaller particles from the feedstock feed. Ideally, there is a seal (not shown) around the aperture 23 to avoid feed flowing into the filter element 2 through the space around the aperture 23. The aperture 23 is preferably in the centre of the screening device 21. As shown in fig. 2 and 3a, the periphery of the screen body 22 includes an outer ring 25 to accommodate the screen body 22. The screening device 21 may be a single piece (fig. 3a, 3 b) or be composed of several pieces together (fig. 3 c).
The screening device 21 may further comprise support beams 24 in the area of the screen body 22 as shown in fig. 2a, 3b and 3d, which support beams serve as reinforcement for reinforcing the screening device 21 or as shown in fig. 3c as an integrated part for forming several pieces of the screening device 21. The different parts of the screening device 21 may be formed in one piece by gluing or by other means of connection. The screening device 21 may be formed as one piece by injection moulding, moulding or even 3D printing as one piece. Alternatively, the polymeric portion of the screening device 21 may be formed as a single piece and combined with other portions made of non-polymeric material.
The screening device 21 is made of organic or inorganic material or a combination of both. The organic screening device 21 may be made of any suitable polymer such as polyolefin (including fluorinated polyolefin), polyamide, polyacrylate, polyester, copolyester (such as TritanTM (available from Eastman ChemicalCo of gold baud, tennessee chemical company)), polysulfone (PS), polyethersulfone (PES), sulfonated Polyethersulfone (SPS), cellulose, polycarbonate (PC), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), fluorinated Ethylene Polymer (FEP), polyvinylidene difluoride (PVDF), polyvinylchloride (PVC), polyacrylonitrile (PAN), acrylonitrile Butadiene Styrene (ABS), and combinations of two or more of these polymers. Inorganic screening device 21 may be made of metal (such as stainless steel), or ceramic components (such as alumina, zirconia, silica, etc.), as well as combinations of two or more of these materials.
The filtration membrane 9 is selected from the non-limiting group consisting of a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, a distillation membrane, a degassing membrane, an ion exchange membrane and a reverse osmosis membrane. The filter membrane 9 is made of organic or inorganic materials or a combination of both. The organic filter membrane 9 may be made of any suitable polymer, such as polyolefin (including fluorinated polyolefin), polyamide, polyacrylate, polyester, copolyester (including TritanTM), polysulfone (PS), polyethersulfone (PES), sulfonated Polyethersulfone (SPS), cellulose, polycarbonate, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), fluorinated Ethylene Polymer (FEP), polyvinylidene fluoride (PVDF), polyvinylchloride (PVC), polyacrylonitrile (PAN), and combinations of two or more of these polymers. The inorganic filter membrane 9 may be a ceramic membrane made of any suitable material such as alumina, zirconia, silica, etc., and combinations of two or more of these materials. The ceramic membrane may be synthesized by a sintering process, a sol-gel process, a phase separation process, a vapor deposition process, or another suitable process known in the art. The filter membrane 9 may have any shape, such as hollow fibers, tubes, porous fibers, knitted fibers, spiral sheets, pleated sheets and flat sheets. In elements with more than one membrane 9, the membrane may have one or more of these shapes or be made of more than one of these materials.
Referring now to fig. 2c, one or both ends 110 of the filter element 2 comprise an opening 12 to introduce feed to the first surface of the filter membrane 9. Referring to fig. 5b and 5c, the filter unit 10 may comprise two or more screening devices 21, 21', and each end of the filter element 2 is connected to at least one screening device 21, 21'. Two or more screening devices 21, 21' may be placed together in parallel alignment through apertures 23. Two or more screening devices 21, 21' may be placed on both sides of the filter element 2. The 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 is reversible. Alternatively, the feed may be introduced from either or both sides of the filtration unit 10. As shown in fig. 5b and 5d, each end of the filter element 2 may be connected to one screening device 21, 21'.
The filter element 2 is directly connected to the screening device 21 by attaching and securing the screening device 21 to the filter element 2 (in one embodiment, by securing the outer ring 25 to the housing 11), as depicted in fig. 2. And in this embodiment connectors 261, 262 as shown in fig. 4 may be used to guide permeate collected in the central tube 8 of the filter element 2. Alternatively, the filter unit 10 may use connectors 261, 262 to connect both the filter element 2 and the screening device 21, thereby indirectly connecting the filter element 2 with the screening device 21 whose outer ring 25 is not directly connected to the housing 11 of the filter element 2 by fitting the connectors 261, 262 to connect both the screening device 21 and the filter element 2 separately.
As shown in fig. 4, connectors 261, 262 may be hollow tubes having hollow chamber 28. The connectors 261, 262 guide the permeate collected in the central tube 8 of the filter element 2 and are equipped with sealing means 27. The connectors 261, 262 are connected to both the screening device 21 and the filter element 2 by being inserted through the apertures 23 of the screening device 21 and into the central conduit 8 of the filter element 2, and the sealing means 27 seals between the connectors 261, 262 and the central conduit 8, thereby forming a fluid seal between the feed and permeate. The first connector 261 has a sealing device 27 (fig. 4b, 4 d) at one end to connect to and seal with only one filter membrane 2. The second connector 262 has sealing means 27 at both ends (fig. 4a, 4 c) and each end of the connector 262 is connected to and sealed with one filter membrane 2. The connectors 261, 262 may further include a protruding base 29 to align and/or rest the screening device 21 thereon. Such a protruding base 29 also achieves a constant spacing between adjacent filter elements 2 on both sides of the protruding base 29. The first connector 261 may further comprise additional parts or be connected to additional parts of the filter system 1, such as the cover 31 shown in fig. 8a and 9 a.
Referring now to fig. 5 and 6, the first connector 261 is connected to the filter element 2 by inserting the end having the sealing device 27 into the central tube 8 of the filter element 2. The sealing means 27 forms a fluid-tight, i.e. gas or liquid impermeable, seal between the feed and the permeate. The first connector 261 is connected to the screening device 21 by inserting one end of the first connector 261 through an aperture 23 of the screening device 21.
Alternatively, without the first connector 261, the filter element 2 comprises a protrusion (not shown) adapted to be connected with the screening device 21 by inserting the protrusion through the aperture 23 of the screening device 21.
Referring now to fig. 5 (a) to 5 (d), there is further provided a filtration system 1 comprising a vessel 3 and at least one filtration unit 10 (shown in fig. 2) as described herein within the vessel 3, the vessel having a plurality of ports on both sides, including a feed port 4, a permeate outlet 5, and optionally a retentate outlet 6, the system comprising:
A filter element 2 having at least one filter membrane 9 with a first surface contacting the feed and a second surface contacting the permeate, at least one end 110 of the filter element 2 comprising an opening 12 to introduce the feed to the first surface of the filter membrane, and a central conduit 8 surrounded by the filter membrane 9 to collect the permeate, and
A screening device 21 connected to an end 110 of the filter element 2, which end comprises one or more openings 12 to introduce feed to the first surface of the filter membrane 9;
Wherein the screening device 21 comprises an aperture 23 positioned substantially in a central portion of the screening device 21, an outer ring 25 in an outer periphery of the screening device 21, and a screen body 22 between the aperture and the outer ring.
The screening device 21 may further comprise at least two layers of screen bodies 22 between the apertures 23 and the outer ring 25. And at least two layers of screen body 22 have screen sizes that may be the same or different. When the filter membrane is a UF or MF membrane, the screen body 22 preferably has a screening size of between 50 and 400 microns, more preferably between 100 and 300 microns, still more preferably between 100 and 150 microns.
In order to reduce the space occupation, at least two sets of filter units 10 are placed inside the container 3, as shown in fig. 1. The filter units 10 may be positioned in series in the horizontal direction or in the vertical direction. Preferably, there is an air inlet port 7 for a vertical system, as shown in fig. 1c and 1 d. Preferably, the filter units 10 are positioned in series in the horizontal direction.
As shown in fig. 6, 8b and 9b, at least two sets of filter units 10 may be placed in series in the horizontal direction within the vessel 3. Preferably, one screening device 21 of one filter unit 10 is located near each side of the filter system 1. For example, in fig. 8b and 9b, a screening device 21 is positioned close to one side of the filter system 1 and another screening device 21' is positioned close to the other side of the filter system 1. The feed flow direction of the filtration system 1 is reversible. During one period of operation, feed may be introduced from feed port 4, and then during another period of operation, feed may be reversed and introduced from feed port 4'. Alternatively, the feed may be introduced from either or both sides of the filtration system 1. The feed may be introduced from either or both of the feed ports 4, 4'.
Referring now to fig. 6b, a second connector 262 is connected to both filter elements 2, 2". Each end of the second connector 262 is connected to one filter element 2 by inserting the end 27 with the sealing means into the central duct 8 of the filter element 2, 2'. The sealing means 27 forms a fluid-tight, i.e. gas or liquid impermeable, seal between the feed and the permeate. In some embodiments, such as shown in fig. 6b, the second connector 262 is connected to both screening devices 21, 21', and each end of the second connector 262 is connected to the screening device 21 by inserting one end of the second connector 262 through the aperture 23 of the screening device 21.
As shown in fig. 9b, there may be one or more individual membrane elements 2 "positioned in series between the two filter units 10, 10'. The filtration system 1 further comprises a second connector 262 to connect each two adjacent membrane elements 2, 2", and the filter elements 2, 2" of the filtration units 10, 10' are indirectly connected to the screening device 21, 21' by fitting connectors 261, 261' to connect both the screening device 21, 21' and the filter elements 2, 2' individually. As shown in fig. 9a, the outer ring 25 may further comprise an outer surface 253 having at least support ribs 251, which are circular O-rings surrounding the outer ring 25 to seal between the outer ring 25 and the inner surface of the container 3.
As shown in fig. 8b, alternatively, two or more filter units 10, 10', 10 "are positioned in series, each filter unit 10, 10', 10" comprising two or more screening devices 21, 21', and each end of a filter element 10, 10', 10 "being connected with at least one screening device 21, 21 '. The filter system 1 further comprises a second connector 262 to connect each two adjacent membrane elements 10, 10', 10", and the filter elements 10, 10', 10" are directly connected to the screening device 21, 21' by attaching and securing the screening device 21, 21' to the filter elements 10, 10', 10 ". As shown in fig. 8a, the inner surface 252 of the outer ring 25 of the screening device 21, 21' is connected to the housing 11. The inner surface 252 is attached to the housing 11 by optional snap means, corresponding grooves and protrusions, threads, heat welding, pressure welding, gluing, 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 against the housing 11 of the filter element 2 to avoid feed from flowing to the first surface of the filter membrane 9 between a potential gap between the inner surface of the outer ring 25 and the housing 11.
As shown in fig. 4a and 4c, the second connector 262 has a hollow shape with sealing means 27 at both ends of the second connector 262. The second connector 262 is adapted to connect each two adjacent membrane elements 2 by inserting each end into the central tube 8 of the filter element 2 and sealing between feed and permeate.
The filtration membrane 9 is selected from the group consisting of MF membrane, UF membrane, NF membrane, distillation membrane, degassing membrane, ion exchange membrane, and RO membrane. The type of membrane is selected independently for each filtration unit. In other words, the filter units may comprise filter membranes of the same type or of different types. Preferably, the filtration membrane 9 is selected from MF membranes and UF membranes. Normal cleaning processes for UF and MF membranes include backwash, air scouring, CEB, CIP, and other methods known to those skilled in the art. The cleaning process most commonly used is backwashing, which is typically performed every 20 to 60 minutes based on feed conditions. With the filter unit 10 and the filter system 1 described herein, when cleaning (such as back flushing) is applied to clean the MF membranes and/or UF membranes, the same cleaning process is also applied to the screening device 21. Thus, no separate cleaning step or additional cleaning agent is required to clean the screening device 21 and the filter element 2 separately, which greatly reduces maintenance time and costs and greatly increases operating efficiency. Furthermore, the filter element described herein implements the single control concept (one-control-philosophy) of the filter unit 10 with both the screening device 21 and the filter element 2.
In the multi-element filtration system 1, the filter membranes 9 of different filter elements 2 may have the same or different materials, pore sizes, morphologies, sizes, shapes, etc. The different filter elements 2 in the filter system 1 may have the same or different configurations, membrane areas, etc. For example, as shown in fig. 6, the pore size of the filter membrane 9 'of the downstream filter element 2' may be larger or smaller than the pore size of the filter membrane 9 in the upstream filter element 2.
The feed flow direction of the filter unit 10 and the filter system 1 is reversible. As shown in fig. 7a, the filtration system 100 comprises a vessel 3 having a plurality of ports on both sides, including a feed port 4, a permeate outlet 5, optionally a retentate outlet 6, a first filtration unit 10, and a second filtration unit 10'. As shown in fig. 7b, the filtration system 100 becomes the filtration system 200 when the feed flow is reversed compared to the flow direction in fig. 7 a. The filtration system 200 includes a vessel 3 having a plurality of ports on both sides, including a feed port 4' (previously the retentate outlet 6 of the filter element 100), a retentate outlet 6' (previously the feed port 4 of the filter element 100), a permeate outlet 5, a first set of filtration units 10, and a second set of filtration units 10'. As shown in fig. 7c, the filtration system 1 comprises a vessel 3 with a plurality of ports on both sides, including feed ports 4, 4', permeate outlet 5, retentate outlet 6, and two sets of filtration units 10, and feed is introduced from both sides of the filtration system 1 from the feed ports 4, 4'. There may also be permeate ports 5 from both sides of the filtration system 1, in addition, one end of the central conduit 8 may be inserted by a plug 30 to seal between the permeate and the feed or retentate, as shown in fig. 5a and 5 c.
Reference numerals
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 is to be understood that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Claim (modification according to treaty 19)
1.A filtration unit, the filtration unit comprising:
a filter element comprising at least one filtration membrane having a first surface for contacting a feed and a second surface for contacting permeate;
Wherein at least one end of the filter element comprises one or more openings to introduce feed to the first surface of the filter membrane, and wherein the filter element further comprises a central conduit surrounded by the filter membrane to collect permeate, and a backwashable screening device connected to the end of the filter element comprising one or more openings to introduce feed to the first surface of the filter membrane;
Wherein the screening device comprises an aperture positioned substantially in the centre of the screening device, an outer ring in the outer periphery of the screening device, and a screen body between the aperture and the outer ring, the screen body having a screening size of between 50 and 400 microns.
2. The filter unit of claim 1, wherein the outer ring comprises an outer surface comprising at least a support ridge.
3. The filtration unit of claim 2, wherein the filtration membrane is surrounded by a housing and the outer ring comprises an inner surface connected to the housing.
4. A filter unit according to claim 3, wherein the filter element comprises two ends and both ends comprise openings through which the feed can be introduced to the first surface of the filter membrane, wherein the filter unit comprises two or more screening devices, and wherein each end of the filter element is connected to at least one screening device.
5. The filtration unit of claim 4, wherein the feed flow direction of the filtration unit is reversible.
6. The filtration unit of claim 1, wherein the filtration unit further comprises a first connector for guiding permeate collected in the central conduit of the filtration element and provided with sealing means, and wherein the first connector is connected to both the screening device and the filtration element by being inserted through an aperture of the screening device and into the central conduit of the filtration element, wherein the sealing means seals between the first connector and the central conduit, thereby forming a fluid seal between the feed and the permeate.
7. The filter unit of claim 6, wherein the first connector further comprises another sealing means for sealing between the first connector and the aperture.
8. The filter unit of claim 7, wherein an inner surface of the outer ring is sealed with respect to a housing of the filter element.
9. The filter unit of claim 1, wherein the screening device comprises at least two layers of screen bodies between the apertures and the outer ring.
10. The filter unit of claim 9, wherein at least two layers of screen bodies between the apertures and the outer ring have different screening sizes.
11. The filter unit of claim 1, wherein the screen body has a screening size between 100 microns and 300 microns.
12. The filtration unit of claim 11, wherein the filtration membrane is selected from the group consisting of a microfiltration membrane and an ultrafiltration membrane.
13. A filtration system comprising a vessel and at least one filtration unit placed within the vessel, the vessel being equipped with a plurality of ports on both sides, including a feed port, a permeate outlet, and optionally a retentate outlet, wherein the filtration unit comprises:
a filter element comprising at least one filtration membrane having a first surface for contacting a feed and a second surface for contacting permeate;
wherein at least one end of the filter element comprises one or more openings to introduce feed to the first surface of the filter membrane, and wherein the filter element further comprises a central conduit surrounded by the filter membrane to collect permeate, and
A backwashable screening device connected to an end of the filter element comprising one or more openings for introducing feed to the first surface of the filter membrane;
Wherein the screening device comprises an aperture positioned substantially in the centre of the screening device, an outer ring in the outer periphery of the screening device, and a screen body between the aperture and the outer ring, the screen body having a screening size of between 50 and 400 microns.
14. The filtration system of claim 13, wherein the filtration system comprises at least two filtration units and one screening device of one filtration unit is positioned adjacent each side of the filtration system.
15. The filtration system of claim 14, wherein the filtration system further comprises another feed port at an opposite side of the filtration system, and the feed flows to either or both feed ports of the filtration system.
16. The filtration system of claim 15, wherein a feed flow direction of the filtration system is reversible.
17. The filtration system of claim 14 wherein the outer ring includes an outer surface including at least a support ridge to abut against an inner surface facing the vessel.
18. The filtration system of claim 14, wherein the filtration membrane is surrounded by a housing and the outer ring comprises an inner surface connected to the housing, wherein the filtration element comprises two ends and both ends comprise openings through which feed can be introduced to a first surface of the filtration membrane, wherein the filtration unit comprises two or more screening devices, and wherein each end of the filtration element is connected to at least one screening device.
19. The filtration system of claim 14, wherein the filtration unit further comprises a first connector and a second connector for guiding permeate collected in the central tube of the filtration element and provided with sealing means, and wherein the first connector is connected to only one filtration unit and the second connector is connected to two filtration units, wherein each connector is connected to a filtration unit by insertion through an aperture of the screening device and into the central tube of the filtration element, wherein the sealing means seals between each connector and the central tube of the filtration element, thereby forming a fluid seal between the feed and the permeate.
20. The filtration system of claim 19, wherein the first connector further comprises another sealing means for sealing between the connector and the aperture.
21. The filter system of claim 20, wherein an inner surface of the outer ring is sealed relative to a housing of the filter element.
22. The filtration system of claim 13, wherein the screening device comprises at least two layers of screen bodies between the apertures and the outer ring.
23. The filtration system of claim 22 wherein at least two layers of screening bodies between the aperture and the outer ring have different screening sizes.
24. The filtration system of claim 13 wherein the screen body has a screening size between 100 microns and 300 microns.
25. The filtration system of claim 24, wherein the filtration membrane is selected from the group consisting of a microfiltration membrane and an ultrafiltration membrane.