Cross flow filtration device

Abstract

The present invention provides a cross-flow filtration device for filtering a pressurized feed liquid. The cross-flow filtration device includes: a filter membrane; a flow channel for the pressurized feed liquid, which extends in a path above the retention surface of the membrane, so that the flow direction in the channel is tangent to the retention surface, and the filtrate from the feed liquid passes through the membrane to leave the retention liquid in the flow channel; and a collection chamber for the filtrate, which is formed on the opposite filtrate surface of the membrane. The cross-flow filtration device also includes a sealed housing having a retention side and a filtrate side, which enclose the flow channel, the filter membrane and the collection chamber therebetween. The cross-flow filtration device also includes a flow channel guide wall disposed at the inner surface of the retention side of the housing. The guide wall is configured to form a fluid seal with the filter membrane, thereby defining the path of the flow channel on the retention surface of the membrane.

Description

Technical Field

[0001] The present disclosure relates to the field of cross-flow filtration devices for filtering pressurized liquids. Background Art

[0002] Cross-flow filtration is a process in which a pressurized feed solution flows tangentially through a membrane that is permeable to the feed solution and the filtrate. As the feed solution flows through one side of the membrane, the filtrate passes through the other side of the membrane, leaving behind the retentate, which is the feed solution that contains almost no filtrate. Thus, the medium in the feed solution that did not pass through the membrane is concentrated in the retentate.

[0003] Typically, the feed flows into a cross-flow filtration device in a cyclic manner, passes through the membrane, and then flows out again, and in each such cycle, the medium is concentrated in the retentate. The filtrate that has passed through the membrane leaves the device through an outlet on the opposite side of the membrane. A restrictor at the retentate outlet is used to generate pressure within the device.

[0004] An example device is the Vivaflow 500 available from Sartorius TM 、Vivaflow 50R TM and Vivaflow200 TM .

[0005] Vivaflow 50R TM A filter box has a rigid, transparent plastic, a retention side plate and a filtrate side plate. These plates are thick enough to resist the stress generated by the pressure of the flowing liquid and are bolted together around their periphery. The box-shaped housing formed in this way contains the flow channel of the feed / retentate in a sealed manner, a permeable membrane and a plate-like porous support body, which supports the membrane and allows liquids such as filtrate to pass relatively unimpeded. The filter box is also characterized in that the inlet in the retention side plate is used for the feed to enter the flow channel, the outlet in the retention side plate is used for the retentate from the flow channel, and another outlet in the filtrate side plate is used for the filtrate to pass through the membrane and the support body. The flow channel is tortuous on the retention surface of the membrane, which helps to expose all the feed to the large surface area of ​​the membrane, and also introduces a tortuous path to generate eddy currents and break the linear flow of the feed, thereby improving the filtration efficiency of the filter box.

[0006] In Vivaflow 50R TMIn the embodiment, the flow channel is formed as a recess in the inner surface of the intercepting side plate. When assembling the filter cartridge, the intercepting side plate, the membrane, the support body and the filtrate side plate are stacked in order, and then the intercepting side plate and the filtrate side plate are fixed together with bolts. The raised portion of the inner surface of the intercepting side plate outside the groove is pressed against the membrane, and the front-to-back depth of the flow channel is exactly the depth of the groove. However, although this arrangement is easy to manufacture and limits the flow path of the feed liquid to the flow channel, due to the incomplete seal formed between the raised portion of the inner surface of the intercepting side plate and the membrane, some feed liquid short-circuits the shuttle flow channel. This short-flow reduces the Vivaflow 200 TM Filtration efficiency.

[0007] Vivaflow 200 TM Features and Vivaflow 50R TM Same, but the difference is that the feed inlet splits the fluid and passes through the retention surface of two membrane layers instead of one. The two membrane layers sandwich the filtrate collection chamber with a porous support, allowing the filtrate to enter from two sides instead of one. The benefit of this is that a larger membrane surface area is achieved, increasing the filtration rate while minimizing the overall size of the device.

[0008] Vivaflow 50 TM A similar but smaller cross-flow filtration unit also available from Sartorius. It has the same functionality as the Vivaflow 50R TM and Vivaflow 200 TM The same, but with some differences in construction. For example, its retentate side plate and filtrate side plate are wedged into thick plastic sleeves to press them together and are sealed to each other with peripheral O-rings.

[0009] There is a need for a cross-flow filtration device that reduces or avoids such short-flow. Summary of the invention

[0010] According to a first aspect of the present invention, there is provided a cross-flow filtration device for filtering pressurized liquid;

[0011] The cross-flow filtration device comprises: a filter membrane; a flow channel for pressurized feed liquid extending in a path above the retention surface of the membrane so that the flow direction in the channel is tangential to the retention surface and filtrate from the feed liquid passes through the membrane leaving retentate in the flow channel; and a collection chamber for the filtrate formed on the opposite filtrate surface of the membrane;

[0012] wherein the cross-flow filtration device further comprises a sealed housing having a retentate side and a filtrate side, wherein the retentate side and the filtrate side enclose the flow channel, the filtration membrane and the collection chamber therebetween; and

[0013] The cross-flow filtration device further comprises a flow channel guide wall disposed at the inner surface of the retention side of the housing, wherein the guide wall is configured to form a fluid seal with the filter membrane, thereby defining a path of the flow channel on the retention surface of the membrane.

[0014] Advantageously, by providing a guide wall configured to form a fluid seal with the filter membrane, the guide wall can provide an effective seal around the edge of the flow channel, thereby substantially eliminating short-circuiting of the flow channel caused by feed liquid.

[0015] The cross-flow filtration device of the first aspect may have any one or any combination of the following optional features.

[0016] According to one approach, the flow channel guide walls may be elastically deformable. They may then deform and sealingly engage the filter membrane to form a fluid seal. Advantageously, by providing guide walls that deform and sealingly engage when in contact with the filter membrane, the guide walls may accommodate and seal different types of membranes, allowing different types of membranes to be used in the same basic device.

[0017] Conveniently, the elastically deformable flow channel guide wall can be formed by an elastomer, such as thermoplastic polyurethane (TPU), natural rubber, silicone rubber, polysiloxane or latex. The guide wall can have a single-component structure or a multi-component structure, such as a multi-layer structure having layers formed of different materials (such as different materials in the above-mentioned elastomer).

[0018] The elastically deformable guide wall may be a component of the device that is separate from the housing and should therefore be correctly disposed thereon when the device is assembled. Conveniently, the trapped side inner surface of the housing may include a recess corresponding to the line of the guide wall, and the elastically deformable guide wall is positioned in the recess to sealably engage with the inner surface. The recess may help to correctly position the guide wall when the device is assembled. In particular, if the guide wall fits tightly in the recess, it may also help to improve the seal between the guide wall and the trapped side inner surface of the housing.

[0019] Yet another option is to permanently co-mould the elastically deformable guide wall into the entrapment side of the housing during the manufacture of these parts of the device.In this way, the guide wall becomes one with the housing, and any problem of sealing the guide wall to the entrapment side of the housing is avoided.

[0020] The cross-flow filtration device including an elastically deformable guide wall may also include one or more interconnecting members extending, preferably outside the path of the flow channel, to connect the inner surface of the retentate side of the housing to the inner surface of the filtrate side of the housing, thereby reinforcing the housing. The interconnecting members may pass through openings in the membrane, and in devices including a porous support (discussed below), the interconnecting members may also pass through openings in the support. The interconnecting members may strengthen the housing against the pressure of the liquid flowing through, thereby allowing the thickness of the housing to be reduced. This in turn helps to reduce manufacturing costs.

[0021] For example, the interconnecting members may be integrally formed as protrusions protruding from the inner surface of one of the retentate and filtrate sides of the housing. They may be connected to the inner surface of the other side using any convenient process, such as ultrasonic welding. However, another option is to integrally form the interconnecting members as pairs of protrusions formed from the inner surfaces of the retentate and filtrate sides of the housing, respectively, with each pair of protrusions meeting at the membrane. In this case, the interconnecting members may not need to pass through an opening in the membrane, i.e. each interconnecting member may be formed by a given pair of protrusions and a small area of ​​membrane enclosed therebetween.

[0022] According to another method, the guide wall can be welded to the filter membrane, the welding locally densifying the filter membrane over its entire thickness to form a fluid-tight seal. For example, it can be formed by ultrasonic welding. As long as the membrane can be densified by welding, this optional feature also allows the guide wall to seal different types of membranes, so that different types of membranes can also be used in the same basic device.

[0023] When the guide wall is welded to the filter membrane, the device may also include a welding support member extending from the inner surface of the filtrate side of the housing to support the welding. In particular, the welding support member may also be welded to the filter membrane. Welding the guide wall and the welding support member and forming a fluid seal may also help strengthen the housing in the manner of the above-mentioned interconnecting members. In a device including a porous support body (discussed below), the welding support member may pass through an opening in the support body. Conveniently, the guide wall may be integrally formed with the entrapment side of the housing and / or the welding support member may be integrally formed with the filtrate side of the housing.

[0024] The guide wall can be configured to make the path of the flow channel tortuous on the retention surface of the membrane, thereby improving the filtration efficiency by forcing all the feed liquid to pass through a large area of ​​the membrane, and helping to generate eddies and turbulence to disrupt linear flow.

[0025] The device may also include: an inlet for the flow channel for the feed liquid; an outlet for the flow channel for the retentate; and an outlet for the collection chamber for the filtrate. In use, external pipes are typically connected to the device at the inlet and outlet, for example so that an external pump can circulate the feed liquid and the retentate through the device. Conveniently, the inlet for the flow channel and the outlet for the flow channel may be formed on the retentate side of the housing, and the outlet for the collection chamber may be formed on the filtrate side of the housing.

[0026] One or more of the inlet and outlet ports may include a respective swivel Luer cuff for connection to a respective external tube.

[0027] The device may also include a porous support located in the collection chamber, which provides mechanical support for the membrane while allowing the filtrate to pass relatively unimpeded, for example to the filtrate outlet. The support may be made of, for example, porous plastic. It may be manufactured by sintering plastic particles. However, other materials and / or manufacturing processes may be used. As an alternative to such a support, projections integrally formed with the housing may protrude from the inner surface of the filtrate side of the housing to support the membrane, which projections allow the filtrate to pass relatively unimpeded between them.

[0028] The housing may be formed of a transparent material. This allows a user to visually monitor the operation of the device. Conveniently, it may be formed of a plastic material. However, other types of materials such as glass, ceramic or metal may also be used for the housing.

[0029] The retentate side and filtrate side of the housing can be formed as individual plates, sandwiching the flow channel guide wall, filter membrane and porous support (if present) between them. In particular, the housing can have a retentate side plate and a filtrate side plate that are sealed together along their respective sealing perimeters to form a cavity therebetween, wherein the guide wall, filter membrane and porous support (if present) are disposed in the cavity. O-rings can be provided around the sealing perimeter to improve the seal therebetween. The plates can be sealed together in various ways, such as: ultrasonic welding, heat fusion; gluing; or mechanical interference. The joining of the plates can be performed or supplemented by mechanical fasteners (e.g., screws, bolts, U-shaped staples, clips, etc.), integral snap-fit ​​connectors and / or wedge-fit mechanisms. Another option is that the sealed housing also includes a molded or overmolded surround that connects the housing together.

[0030] The device may also include complementary structures located on opposite sides of the device and configured so that the structures on one side of the device can engage with the complementary structures on the other side of another device, so that multiple devices are connected together to form a larger group. For example, the complementary structures may include a pair of convex and concave structures, such as guide rails and grooves. Such a larger group of devices can be connected in parallel or in series fluid to process a larger volume of feed liquid.

[0031] The device may also include external support feet protruding from the filtrate side of the housing. When the support feet are placed on a work surface (e.g., a laboratory bench), the device is raised from the surface, thereby providing better access to, for example, its inlet and outlet, particularly any rotating Luer cuffs. In addition, by having the support feet protrude from the filtrate side of the housing, the collection chamber will be located below the filter membrane, thereby facilitating the passage of the filtrate through the membrane by gravity.

[0032] The device may be sterile, for example. -3 , preferably at least 10 -6 Typical methods for sterilizing devices include ethylene oxide gas and radiation. Sterility assurance levels can be validated in accordance with appropriate standards, such as ISO 11135:2014 for ethylene oxide gas and ISO 11137:2006 for radiation. Advantageously, the device can be configured to reduce capture areas and improve the effectiveness of the selected sterilization process, particularly in the inlet and outlet areas. The use of ultrasonic welding to connect components of the device is also generally beneficial in promoting sterilization because such a connection process does not require the use of fixtures, fasteners, adhesives or other components that may compromise sterility.

[0033] The device may be a double membrane device having a second filter membrane and corresponding flow channels and flow channel guide walls on the opposite side of the collection chamber, i.e. the collection chamber is sandwiched between the first filter membrane and the second filter membrane, the filtrate passing through each membrane into the collection chamber. The retention side of the sealed housing thus becomes the first retention side, and the filtrate side of the housing becomes the second retention side. Typically, the porous support is located in the collection chamber of the device.

[0034] The optional features discussed above are also relevant to the corresponding features of the dual membrane device. Conveniently, when the device includes one or more interconnecting members, they can pass through openings in the first membrane and the second membrane, and typically through the porous support. The inlet for the feed liquid can be a single inlet that supplies liquid to both flow channels. The outlet for the retentate can be a single outlet that receives the retentate from both flow channels. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Embodiments of the present disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0036] Figure 1 shows a perspective view of a sealed housing of a cross-flow filtration device;

[0037] Figure 2 Shows Figure 1 A first exploded view of a cross-flow filtration device;

[0038] Figure 3 Shows Figure 1 A second exploded view of a cross-flow filtration device;

[0039] Figure 4 Shows Figure 1 A third exploded view of the cross-flow filtration device;

[0040] Figure 5 Shows Figure 1 A plan view of a cross-flow filtration device;

[0041] Figure 6 shows a plan view of a variation of a cross-flow filtration device;

[0042] Figure 7 Shows Figure 6 The cross section of the device variant along line XX;

[0043] Figure 8 shows a cross section of a portion of a second variation of a cross-flow filtration device;

[0044] Fig. 9 shows a cross section of a portion of a third variation of a cross-flow filtration device;

[0045] Fig.10 Shows Fig. 9 A detailed isometric view of the inner surface of one of the side panels of the third variation of the cross-flow filtration device; and

[0046] Fig.11 Shows Fig.10 Detailed isometric view of a portion of the flow distributor and channel guide walls located on the side panels. DETAILED DESCRIPTION

[0047] Figure 1 A perspective view of a sealed housing of a cross-flow filtration device 17 is shown, the housing comprising a retentate side plate 1 and a filtrate side plate 2, defining a cavity between them. An inlet 7 for the feed liquid to flow into the cavity is formed in the retentate side plate 1, an outlet 8 for the retentate liquid 8 to flow out of the cavity is formed in the retentate side plate 1, and an outlet 9 for the filtrate to flow out of the cavity is formed in the filtrate side plate 2.

[0048] The feed inlet 7 has a female Luer connection, while the retentate outlet 8 and the filtrate outlet 9 both have male Luer connections with corresponding swivel Luer ferrules. The Luer connections allow external tubing connectors to be connected to the device 17.

[0049] Figures 2 to 4 They are Figure 1 An exploded view of the cross-flow filtration device 17. Figure 2 and Figure 4 The inner surface of the filtrate side plate 2 can be seen, and from Figure 3The inner surface of the retentate side plate 1 can be seen. The housing plates 1, 2 are each formed as a square plate and sandwich therebetween, in order from the retentate side to the filtrate side: an elastically deformable flow channel guide wall 3, a filter membrane 4 and a porous support 5. As discussed in more detail below, the plates 1, 2 are connected together around their respective peripheries to form a sealed module. Conveniently, the plates 1, 2 can be formed of a rigid, transparent plastic material.

[0050] Guide wall 3 ( Figure 2 1 and 17. The guide wall 3 is formed as a one-piece elastomeric molding which, when engaged on one side with the inner surface of the retaining side plate 1 and on the other side with the filter membrane 4, defines a path for the flow channel 10 which meanders over the retaining surface of the membrane 4 from the inlet 7 to the outlet 8. To aid in the proper positioning of the guide wall 3 in the device 17, the inner surface of the retaining side plate 1 has a recess 18 formed therein (e.g., Figure 3 As shown), the line corresponding to the guide wall 3 and the wall can fit into the recess. Alternatively, the guide wall 3 can be molded together with the retaining side plate 1 so that the two parts are permanently combined.

[0051] The guide wall 3 is made of a medically safe elastomer, such as TPU, natural rubber, silicone rubber, polysiloxane or latex, which is highly resistant to leaching. This reduces or avoids any risk of contamination of the filtrate and feed / retentate flowing through the device 17. The elastic and compliant guide wall 3 adapts to and accommodates any irregularities in the retention surface of the filter membrane 4, forming a good seal around the edge of the flow channel 10. Therefore, they substantially prevent any short-flow of liquid from the inlet 7 to the outlet 8 on the flow channel 10. In addition, they can adapt to different types of membranes 4 (such as polyethersulfone membranes, regenerated cellulose membranes or cellulose acetate membranes), and can help prevent damage to any surface treatment 4 of the membrane, such as specialized receptors attached to the membrane). Therefore, the same basic filtration device can be used for many different applications by simply changing the membrane type. In particular, the device 17 can be used for filtration that is scaled up or down on a laboratory bench, for example for the production of biopharmaceuticals such as antibodies.

[0052] The porous support 5 fills the collection chamber for the filtrate, which is created by that portion of the shell cavity between the membrane 4 and the inner surface of the filtrate side plate 2. The support 5 physically supports the membrane 4 over substantially its entire area, allowing a pressure differential to be created across the membrane 4, driving the filtrate to flow through the membrane 4. The pores in the support 5 are formed so that the filtrate can pass through it relatively unimpeded on its way from the membrane 4 via the collection chamber to the outlet 9. Conveniently, the support 5 can be a porous plastic body formed by sintering plastic particles.

[0053] In use, external pipes connected to the feed inlet 7 and the retentate outlet 8 are connected to an external pump. Another external pipe is connected to the filtrate outlet 9 and extends to a collection container. The pump continuously circulates the feed into the device through the inlet 7, along the flow channel 10 defined by the guide wall 3, and returns to the pump from the outlet 8 as retentate. The flow direction of the liquid in the flow channel 10 is tangential to the retentate surface of the membrane 4, and the pressure difference across the membrane 4 drives the filtrate from the feed through the membrane 4. The restrictor (not shown) at the retentate outlet 9 is used to generate a pressure 17 within the device.

[0054] The tortuosity of the flow channel 10 forces all of the feed liquid to pass through the large surface area of ​​the intercepting surface of the membrane 4. It also creates eddies and turbulence in the feed liquid, which disrupts its linear flow. More specifically, the path of the flow channel 10 consists of a series of continuous, anti-parallel linear segments that span the width of the membrane 4 and are connected by continuous 180-degree turns. Figure 5 is a plan view of a cross-flow filtration device 17 with internal features shown in phantom and the path of the flow channel 10 best shown.

[0055] Therefore, the result of operating the device is that when the pump circulates the feed liquid, the filtrate from the feed liquid is collected in the collection container connected to the filtrate outlet 9 through the porous support, while the medium in the feed liquid does not pass through the membrane 4 and is concentrated in the retentate.

[0056] To form the housing, the housing plates 1, 2 can be arranged along one of the plates (in this example, the filtrate side plate 2, as shown in FIG. Figure 2 and 4 ) and a corresponding peripheral ridge 15 of another plate (in this example, the retaining side plate 1, as shown) Figure 3 The guide walls 3 are formed by welding the plates 1, 2 together with the filter membrane 4 and the support body 5. ... support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the filter membrane 4 and the support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the filter membrane 4 and the support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the support body 5. The guide walls 3 are formed by welding the plates 1, 2 together with the

[0057] However, in order to control this spacing, while also strengthening the ability of the housing to resist pressure in operation, an interconnecting member 16 can be provided to physically connect the inner surfaces of the housing plates 1, 2. The interconnecting member 16 passes through a dedicated opening in the membrane 4 and in the support body 5 outside the path of the flow channel 10. For example, the interconnecting member 16 can be formed as a protrusion protruding from the inner surface of one of the plates (in this example, the retentate side plate 1), and when assembling the device 17, it can be connected to the inner surface of the other plate (in this example, the filtrate side plate 2) by a suitable connection process. Conveniently, the interconnecting members 16 can act as additional energy directors, allowing them to be ultrasonically welded to the other plate. By strengthening the housing, they allow the housing plates to be made of thinner materials.

[0058] The filtrate side plate 2 has an external support foot 11 at each corner thereof (e.g. Figure 3 and 4 ), the device 17 can be placed on external feet 11. When the feet 11 are placed on a work surface, the device 17 is supported so that the collection chamber is directly below the membrane 4. This allows gravity to help the filtrate pass through the membrane 4. In addition, the feet 11 raise the horizontal position of the entire device so that the Luer cuff 6 of the outlet 9 can rotate unhindered.

[0059] Opposite edges of the housing have mounting slots 12 and mounting rails 13, respectively. They are configured so that the mounting slot 12 of one device 17 can engage with the mounting rail 13 of a second device 17, thereby allowing multiple devices 17 to be connected together to form a larger group and then fluidly connected in series or parallel to increase the ability to filter larger volumes. Each of the mounting slots 12 and rails 13 is partially formed by one of the plates 1, 2 and partially formed by the other plate 1, 2.

[0060] The device can be manufactured sterile, typically using ethylene oxide gas and radionuclide, X-ray or electron beam radiation.

[0061] Figure 6 A plan view of a variant of a cross-flow filtration device 17 is shown, with internal features also indicated by dashed lines. Figure 7 A cross section of a device variant along line XX is shown. Device variants and Figures 1 to 5 Features common to the devices have the same reference numerals.

[0062] Instead of an elastically deformable flow channel guide wall 3, the device variant has a rigid plastic guide wall 3' to define the path of the flow channel 10. The wall is part of a moulding which also forms the retaining side plate 1 and is permanently ultrasonically welded to the filter membrane 4. This welding densifies the membrane locally over its entire thickness to form a fluid-tight seal, preventing any short-circuiting of the liquid on the flow channel 10 from the inlet 7 to the outlet 8.

[0063] To support the welding, support walls 20 protrude from the inner surface of the filtrate side plate 2 through the collection chamber and mirror the line of the guide wall 3'. Conveniently, these support walls are part of the moulding that also forms the filtrate side plate. The support walls pass through corresponding openings in the support body 5 and are also permanently connected to the filter membrane 4 by ultrasonic welding. Figure 7 An enlarged view A of a cross section of a weld is shown.

[0064] Advantageously, the support wall 20 is combined with the guide wall 3' to Figures 1 to 5 The interconnecting members 16 of the device strengthen the housing in the same manner.

[0065] Figures 8 to 11 Cross-sectional and isometric views of components of the second and third cross-flow filtration device variants are shown. As previously described, the second and third device variants are Figures 1 to 7 Features common to the devices have the same reference numerals.

[0066] Figure 8 A variant is a double membrane device in which the first and second filter membranes 4 are sandwiched on opposite sides of a support 5. In this way, the filtrate enters the collection chamber from both sides rather than just one side to increase the filtration rate while maintaining substantially the same overall dimensions of the device.

[0067] Conveniently, the dual device has a single inlet 7 (and a corresponding single retentate outlet - not shown) which supplies liquid to the flow channels 10 of both membranes 4. The inlet 7 extends from one of the housing side panels 1 in the plane of the device, and passages 19 are molded into both housing side panels 1, 2 to bring liquid from the inlet to the flow channels on either side of the support 5. In order to facilitate the formation of the passages 19 during the molding of the side panels 2 (without the inlet), the panels 2 are molded with their passages 19 open to the outer surface of the panels. Thereafter, the passages are closed on the outer surface beneath a separately molded cover 30.

[0068] Figures 9 to 11 A variation of this is another dual membrane device. Figure 8 The device of is different in that the inlet 7 extends from one of the housing side plates 1 perpendicular to the plane of the device. A passage 19 is also formed in both side plates 1, 2 to bring liquid from the inlet to the flow channels 10 of the two membranes 4. However, in this variant, the passage is formed by molding matching recesses 25 in the inner surface of the two side plates, as shown in FIG. Fig.10 As shown, holes are provided in the membrane 4 and the support body 5 to align with these recesses. A diverter body 21 extends through the holes and into matching recesses at each end. The body has a central bushing 22 with an axial hole to allow liquid to pass through the device from one side to the other, and also has sealing caps 23 at both ends of the bushing, which seal the corresponding filter membrane 4 on each side of the diverter body to prevent liquid from leaking through the aligned membrane holes and bypassing the membrane.

[0069] The passage 19 is formed by a corresponding array of slits 26 that radiate outwardly from a central well 27 formed in the base of the recess 25 to provide fluid communication between the end of the axial bore of the bushing 22 and the flow passage 10. The sealing cover 23 of the diverter body 21 is sandwiched between the bases of the recesses 25 to hold the body in place. One of the bushing 22 and the sealing cover 23 (e.g. Fig.11 However, another sealing cover 23 ( Fig.11 4 and the support body 5) can only be mounted on the bushing after it has been inserted through the aligned holes of the membrane 4 and the support body 5.

[0070] It should be understood that the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the concepts described herein. Except for mutually exclusive situations, any feature can be used alone or in combination with any other feature, and the present disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.

Claims

1. A cross-flow filtration device (17) for filtering pressurized liquid; in, The cross-flow filtration device comprises: a filter membrane (4); a flow channel (10) for pressurized feed liquid extending in a path above the retentate surface of the membrane so that the flow direction in the channel is tangential to the retentate surface and filtrate from the feed liquid passes through the membrane leaving retentate in the flow channel; and a collection chamber for the filtrate formed on the opposite filtrate surface of the membrane; The cross-flow filtration device further comprises a sealed housing having a retentate side (1) and a filtrate side (2), wherein the retentate side (1) and the filtrate side (2) enclose the flow channel (10), the filter membrane (4) and the collection chamber therebetween; The cross-flow filtration device further comprises an elastically deformable flow channel guide wall disposed on the inner surface of the retention side (1) of the housing, the guide wall deforming and sealingly engaging with the filter membrane (4) to form a fluid seal with the filter membrane (4), thereby defining the path of the flow channel (10) on the retention surface of the membrane; the guide wall is configured such that the path of the flow channel is circuitous on the retention surface of the membrane; and The inner surface of the retaining side (1) of the housing comprises a recess (18) corresponding to the line of the guide wall, and the guide wall is located in the recess (18) to seal with the inner surface of the retaining side of the housing.

2. The cross-flow filtration device (17) according to claim 1 further includes one or more interconnecting members (16), which extend beyond the path of the flow channel (10) to connect the inner surface of the retention side (1) of the shell to the inner surface of the filtrate side (2) of the shell, thereby strengthening the shell.

3. A cross-flow filtration device (17) according to claim 2, wherein the interconnecting member (16) passes through an opening in the membrane (4).

4. A cross-flow filtration device (17) for filtering pressurized liquid, in, The cross-flow filtration device comprises: a filter membrane (4); a flow channel (10) for pressurized feed liquid extending in a path above the retentate surface of the membrane so that the flow direction in the channel is tangential to the retentate surface and filtrate from the feed liquid passes through the membrane leaving retentate in the flow channel; and a collection chamber for the filtrate formed on the opposite filtrate surface of the membrane; The cross-flow filtration device further comprises a sealed housing having a retentate side (1) and a filtrate side (2), wherein the retentate side (1) and the filtrate side (2) enclose the flow channel (10), the filter membrane (4) and the collection chamber therebetween; Wherein, the cross-flow filtration device further comprises a flow channel guide wall arranged at the inner surface of the retention side (1) of the housing; and The guide wall is welded to the filter membrane (4), and the welding locally densifies the filter membrane over its entire thickness to form a fluid seal with the filter membrane, thereby defining the path of the flow channel on the retention surface of the membrane, and the guide wall is configured so that the path of the flow channel is tortuous on the retention surface of the membrane.

5. The cross-flow filtration device (17) of claim 4, wherein the device further comprises a weld support member (20) extending from an inner surface of the filtrate side (2) of the housing to support welding.

6. The cross-flow filtration device (17) according to claim 5, wherein the welding support member (20) is also welded to the filtration membrane (4).

7. The cross-flow filtration device (17) according to any one of the preceding claims, wherein the housing comprises: An inlet (7) of the flow channel (10) of the feed liquid; an outlet (8) of the flow channel of the retentate liquid; and an outlet (9) of the collection chamber of the filtrate.

8. The cross-flow filtration device (17) according to claim 1 or 4, further comprising a porous support (5) located in the collection chamber, wherein the support provides mechanical support for the membrane (4) while allowing the filtrate to pass through the membrane (4) relatively unimpeded.

9. A cross-flow filtration device (17) according to claim 1 or 4, wherein the shell has a retention side plate (1) and a filtrate side plate (2), and the retention side plate (1) and the filtrate side plate (2) are sealed together along their respective sealing peripheries to form a cavity therebetween in which a guide wall and a filter membrane (4) are arranged.

10. A cross-flow filtration device (17) according to claim 1 or 4, wherein the device further comprises complementary structures located on opposite sides of the device and configured such that the structures on one side of the device can engage with the complementary structures on the other side of another device, so that a plurality of devices can be connected together to form a larger group.

11. The cross-flow filtration device (17) according to claim 1 or 4, wherein the device further comprises a support leg (11) located on the sealing housing.

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