Apparatus and method for manufacturing bundle of hollow fiber membranes

Abstract

The present disclosure relates to an apparatus and a method for producing a bundle of hollow fiber membranes. The bundle is used to produce a filtration and / or diffusion device, such as a capillary dialyzer.

Description

Technical Field

[0001] The present disclosure relates to apparatus and methods for producing bundles of hollow fiber membranes. The bundles are used to make filtration and / or diffusion devices, such as capillary dialyzers.

[0002] Related technical description

[0003] US 4 276 687 A discloses a method for producing a hollow fiber bundle, which comprises winding fibers on a reel member to form an annular assembly of fibers, and then cutting the annular assembly into individual bundles. Each bundle is wrapped in a flexible sheet and cut at both ends.

[0004] US 6 951 611 A discloses a method for manufacturing a hollow fiber membrane module, which involves a filter housing having a first and a second part flexibly connected to each other. The filter housing is mounted on a winding wheel; as the wheel rotates, hollow fibers are continuously fed into the first part of the filter housing; and the first and second parts of the filter housing are subsequently connected together.

[0005] WO 2016 / 102364 A1 discloses a device for winding a foil around a wire of a hollow fiber membrane with an irregular cross section and forming the wire into a circular bundle. The device includes at least four forming segments, which can be moved toward the center of the circle respectively. When these segments move, their contours form a closed line that is approximately circular. At the starting position, these segments are fully opened, and the sheet of film-wrapped and fiber-wrapped wire is inserted into the device. The film is bent to a certain extent by the rotational movement of these segments, which makes the film partially wrap the fiber wire, wherein initially one side of the film is folded more than the other side. Two inner mold segments move upward approximately at the same time to form an approximately semicircular groove supporting the wire, and then the outer mold segments move to the wire in sequence, so that the edges of the film overlap each other and surround the wire. After the wire is compressed to the desired diameter, the wire is fixed by welding the overlapping areas of the film together or fixing them with tape.

[0006] EP 2 420 464 A1 also discloses a device for wrapping a fiber bundle with a film, the device comprising a container, the container comprising a first and a second side element and a flexible channel fixed therebetween for picking up the film and the fiber bundle; the device is also provided with a drive for moving at least the first side element transversely to the chute, and at least one folder which can be moved transversely to the chute for folding the film around the fiber bundle.

[0007] US2021 / 106949 A1 discloses a device for preparing a hollow fiber membrane bundle wrapped in a wrapping material (such as a polymer film, paper or aluminum foil). A winding wheel is provided, which is equipped with a plurality of devices for winding a hollow fiber membrane bundle. Each device includes a base having a groove in the shape of a cylindrical portion; on each longitudinal side of the groove, there is a rigid flap, the inner surface of which forms a cylindrical portion, and each of the two flaps is connected to the base by a hinge, and the hinge is located on the longitudinal edge of the groove, so that each of the two flaps can be moved between a first position and a second position. The device is configured to receive a sheet of wrapping material and a plurality of fibers when both flaps are in the first position, and when both flaps are in the second position, the groove and the two flaps together form a cylindrical gap. A method for preparing a plurality of hollow fiber membrane bundles is provided, each bundle being encapsulated in a sheet of a wrapping material, the method comprising: moving two flaps of each device of a winding wheel to a first position; placing a sheet of a wrapping material into each device; placing a plurality of hollow fiber membranes into each device by winding a wire of the hollow fiber membrane onto the winding wheel and into a groove of the device so that the hollow fiber membranes are located on the upper part of the sheet of the wrapping material; forming a cylindrical hollow fiber membrane bundle and encapsulating it with the wrapping material by moving the flap of each device in turn to a second position; and sealing the longitudinal edges of the sheet of the wrapping material.

[0008] US 4 224 094 A discloses a method and apparatus for simultaneously preparing a plurality of hollow fiber devices, wherein at least one hollow fiber is wound on at least three mechanisms located in different planes, thereby obtaining a cladding having a polygonal portion with the fiber, which cladding can be cut at at least two positions during formation to obtain at least two groups of hollow fibers of different lengths. SUMMARY OF THE INVENTION

[0010] The present disclosure provides an apparatus and method for producing a hollow fiber membrane bundle. The apparatus of the present disclosure is configured to accommodate a hollow fiber membrane bundle and includes a base and a cover connected to the base by a hinge. The base and the cover both have a groove in the shape of a cylindrical portion. When the apparatus is in a closed configuration, the cylindrical portions of the base and the cover together form a complete cylinder. When the apparatus is in a closed configuration, the base and the cover are in contact with each other, and the base and the cover both have a longitudinal edge, which has a periodic curve form oscillating around a mean value, rather than a straight longitudinal edge.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Perspective views showing a prior art device for producing a bundle of hollow fiber membranes: a) open configuration, b) closed configuration;

[0013] Figure 2Perspective views showing embodiments of the device of the present disclosure: a) open configuration, b) closed configuration;

[0014] Figure 3 showing a side view of an embodiment of the device of the present disclosure in a closed configuration;

[0015] Figure 4 Shows Figure 3 Cross-sectional views of the device a) along line AA, b) along line NN.

[0016] Detailed Description

[0017] The present disclosure provides an apparatus for producing a hollow fiber membrane bundle. One embodiment is an apparatus configured to receive and hold a hollow fiber membrane bundle. The apparatus includes a base and a rigid cover connected to the base by a hinge. The cover can rotate about respective hinges to move the cover between a first position corresponding to an open configuration of the apparatus and a second position corresponding to a closed configuration of the apparatus.

[0018] Both the base and the cover have a groove in the shape of a cylindrical portion. When the device is in the closed state, the cylindrical portions of the base and the cover together form a complete cylinder. In other words, in the closed configuration, the inner surface of the device, i.e. the inner surface of the groove of the base and the cover, lies on the surface area of ​​the cylindrical void. The inner surface of the device completely covers the surface of the cylindrical void, i.e. the inner surface of the device forms a cylinder. There are no gaps on the surface that allow a single hollow fiber to pass through.

[0019] The advantage of this device is that it can be easily mounted on a winding wheel for collecting the wire of the hollow fiber membrane, or easily removed from the winding wheel, and can be repeatedly used to produce hollow fiber membrane bundles. The hollow fiber membrane bundle does not require additional wrapping material because the entire outer surface of the hollow fiber membrane bundle is enclosed in the device when the device is in the closed configuration.

[0020] Before the hollow fibers are introduced into the device, the lid of the device is opened, and after the required number of hollow fiber membranes are collected, the lid of the device is closed. In order to prevent the hollow fiber membranes in the device from being sandwiched between the base and the lid of the device when the lid is closed and thus deformed or damaged, the contours of the edges of the base and the lid that are in contact with each other in the device of the present disclosure adopt a special form. When the device is in a closed state, the base and the lid are in contact with each other, and both the base and the lid have longitudinal edges that have a periodic curve form oscillating around an average value, rather than a straight longitudinal edge. In the closed state of the device, the base and the lid together form a tight seal over the entire length of the device.

[0021] In one embodiment, the periodic curve corresponds to a cosine curve A*cos(x), which has a maximum value at both ends of the device. In another embodiment, the periodic curve corresponds to an inverse cosine curve A*(-cos(x)), which has a minimum value at both ends of the device. In yet another embodiment, the periodic curve corresponds to a sine curve A*sin(x), the amplitude of which corresponds to the average value at both ends of the device. In another embodiment, the periodic curve consists of continuous circular or elliptical segments of alternating orientation. In one embodiment, the central angle of each segment is equal to or less than 180°, such as 60° to 90°, such as 70 to 80°. In a specific embodiment, the periodic curve consists of a series of circular segments of alternating orientation and having the same radius, and the radius is in the range of 10 mm to 30 mm, such as 15 to 20 mm.

[0022] In one embodiment, the length of the device corresponds to an integer number of periods of the periodic function. In a further embodiment, the integer ranges from 2 to 12, such as 4 to 8.

[0023] In one embodiment, the amplitude of the periodic function, measured from the line representing the mean value, is 4 mm to 20 mm, such as 5 mm to 15 mm.

[0024] Due to the particular shape of the longitudinal edges of the base and the cover, the contribution of the cover and the base to the cylinder varies along the length of the cylinder, oscillating between two extreme values. In one embodiment, the average contribution of the cover and the base corresponds to 180° of the entire circle. In another embodiment, the groove of the cover occupies a smaller part of the entire cylinder than the groove of the base. In one embodiment, the average contribution of the cover corresponds to 90° to 160° of the entire circle (360°), and the average contribution of the base corresponds to 200° to 270° of the entire circle. In another embodiment, the average contribution of the cover corresponds to 120° to 150° of the entire circle, and the average contribution of the base corresponds to 210° to 270° of the entire circle. In one embodiment, the contribution of the cover varies between 100° and 150° of the entire circle with the length of the cylinder, and the contribution of the base varies between 210° and 260° of the entire circle with the length of the cylinder.

[0025] In the closed configuration, the inner surface of the device forms a cylinder. In one embodiment, the diameter of the cylinder is in the range of 30 mm to 50 mm, for example 35 mm to 45 mm. In a specific embodiment, the inner diameter is in the range of 35 mm to 38 mm. In another embodiment, the diameter of the cylinder is in the range of 15 mm to 25 mm, for example 17 mm to 20 mm.

[0026] The present disclosure also provides a winding wheel equipped with a plurality of the above-mentioned devices. In one embodiment, the winding wheel is equipped with 4 to 30 devices. In one embodiment, the winding wheel also includes a mechanism for moving the cover of the device back and forth between a first position and a second position, that is, a mechanism for changing the device between an open and a closed configuration and between a closed and an open configuration. The winding wheel can produce multiple hollow fiber membrane bundles at the same time.

[0027] The present disclosure also provides a method for preparing a hollow fiber membrane bundle. The method includes providing a device according to the present disclosure in an open configuration, collecting a plurality of hollow fiber membranes in a tank of the device to produce a hollow fiber membrane bundle, then closing the lid of the device to confine the hollow fiber membrane bundle in a cylindrical void of the device, and then cutting the hollow fiber membrane bundle at both ends of the device to obtain a hollow fiber membrane bundle with a defined length.

[0028] When multiple hollow fiber membranes are introduced into the grooves of the device, there is no additional wrapping material in the grooves of the device, while the prior art methods disclosed in WO 2016 / 102364 A1, EP 2 420 464 A1 and US2021 / 106949 A1 respectively use sheets of wrapping material, wherein the sheets of wrapping material are introduced into the collecting device, and then the hollow fiber membranes are introduced, and the sheets of wrapping material are wrapped around the wires of the hollow fiber membranes to form a wrapped bundle.

[0029] One embodiment of the method uses a plurality of devices disclosed herein. These devices are mounted on a winding wheel to produce a plurality of hollow fiber membrane bundles simultaneously. In the method, a plurality of hollow fiber membranes are introduced into each of a plurality of devices by winding the wire of the hollow fiber membrane onto the winding wheel so that it enters the groove of the device. Similarly, when the wire of the fiber is wound onto the winding wheel, there is no additional wrapping material in the groove of the plurality of devices.

[0030] In one embodiment, the method involves sending the wire of the hollow fiber membrane to a winding wheel, and collecting the wire of the hollow fiber membrane in an open configuration according to the present disclosure arranged on the periphery of the winding wheel by rotating the winding wheel. Once the desired fiber bundle thickness or fiber bundle size is reached, the winding wheel is stopped, the device is closed around the wire of the hollow fiber membrane, and the hollow fiber membrane is subsequently cut between the devices. The device is removed from the winding wheel, and the hollow fiber membrane bundle is transferred to a tubular filter housing.

[0031] In one embodiment, the device has a mechanism to facilitate opening and closing the lid, such as a handle, knob or roller attached to the lid. During the method, the device is opened and closed as needed, such as using a robot. In one embodiment, a winding wheel on which multiple devices are mounted is equipped with such a mechanism that mechanically closes or opens the lid of each device as the winding wheel rotates, as required by each process step.

[0032] The exemplary embodiments of the apparatus and method disclosed herein are further described with reference to the accompanying drawings. In all figures, the same reference numerals are used to refer to similar features.

[0033] It is to be understood that the features mentioned above and those described below can be used not only in the combination specified but also in other combinations or alone, without departing from the scope of the present invention.

[0034] Detailed Description of the Drawings

[0035] Figure 1 Two perspective views of a prior art device 20 for producing bundles of hollow fiber membranes are shown. Figure a) shows the device 20 in an open configuration, and Figure b) shows the device 20 in a closed configuration (rotated 180° about the z-axis). The device 20 includes an elongated base 21 having a groove having the shape of a cylindrical portion. The cover 22 is located on one longitudinal side of the base 21. As can be seen from Figure b), when the device 20 is in a closed configuration, the groove of the base 21 and the inner surface of the cover 22 together form a cylindrical void. The diameter of the cylindrical void of the device 20 is 37 mm.

[0036] Figure 2Two perspective views of an embodiment of the device 1 of the present disclosure are shown. Figure a) shows the device 1 in an open configuration, and Figure b) shows the device 1 in a closed configuration (rotated 180° about the z-axis). The device 1 includes an elongated base 2, the base 2 having a groove, the groove having the shape of a cylindrical portion. A cover 3 is located on one longitudinal side of the base 2. The inner surface of the cover 3 forms a cylindrical portion. The cover 3 is connected to the base 2 by a hinge 4, so that the cover 3 can be moved between a first position (corresponding to the open configuration) as shown in Figure a) and a second position (corresponding to the closed configuration) as shown in Figure b). When the cover 3 is in the first position, a plurality of fibers can be introduced into the device. When the cover 3 is in the second position (as shown in Figure b), the groove of the base 2 and the inner surface of the cover 3 together form a cylindrical gap 7. The longitudinal edge 5 of the base 2 and the longitudinal edge 6 of the cover 3 are shaped in the form of a periodic curve oscillating around a mean value. The shapes of the longitudinal edges 5 and 6 correspond to each other, so that when the device 1 is in the closed configuration, the base 2 and the cover 3 form a tight fit. The device 1 also has a handle 8 for opening and closing the device 1. The base 2 is connected to a mounting plate 9 to facilitate mounting the device 1 on a winding wheel.

[0037] Figure 3 A side view of a device 1 according to an embodiment of the present disclosure in a closed configuration is shown. L is the total length of the device. In the embodiment shown in the figure, the wavelength of the periodic curve formed by the longitudinal edges 5 and 6, respectively, is L / 6, i.e. the length of the edges 5 and 6, respectively, corresponds to six complete periods of the curve. In the embodiment shown in the figure, the length L of the device is 265 mm and the periodic curve consists of a series of circular segments each with a radius of 18 mm. In the embodiment shown in the figure, the curve has a maximum value at both ends of the device 1. In other embodiments of the device 1, the curve has a minimum value at both ends of the device 1.

[0038] Figure 4 Shows Figure 3 The device 1a) along the line AA, b) along the line NN cross-sectional view. The assembly plate 9 is fixed to the base 2 by bolts 10, and the handle 8 is fixed to the cover 3 by bolts 11.

[0039] As can be clearly seen from Figures a) and b), respectively, the contribution of the cover 3 and the base 2 to the cross-sectional area of ​​the cylinder 7 varies with the length of the cylinder 7. At the section NN shown in Figure b), which corresponds to the maximum of the periodic curve, the contribution of the cover 3 to the cross-sectional area of ​​the cylinder 7 is less than at the section AA shown in Figure a), which is close to the minimum of the periodic curve. In the embodiment shown in the figure, the diameter of the cylindrical void 7 of the device is 37 mm. Example

[0040] Comparative Example 1

[0041] Use equipment such as Figure 1 The winding wheel of the prior art device 20 shown produces hollow fiber membrane bundles, each of which contains 12024 hollow fibers, which are then transferred to the dialyzer housing. The hollow fiber membrane bundles are then inspected for defects such as knots, kinks, and breaks.

[0042] 72 dialyzers were analyzed. A total of 128 defects were observed, corresponding to 1.78 defects / bundle.

[0043] Example 1

[0044] Use equipment such as Figures 2 to 4 The winding wheel of the device 1 shown produces hollow fiber membrane bundles, each of which contains 12024 hollow fibers, which are then transferred to the dialyzer housing. The hollow fiber membrane bundles are then inspected for defects such as knots, kinks, and breaks.

[0045] 117 dialyzers were analyzed. A total of 140 defects were observed, corresponding to 1.20 defects / bundle.

[0046] The number of defects present in the bundles produced using the apparatus of the present disclosure was reduced by about one third compared to bundles produced using prior art apparatus.

[0047] Reference numerals list

[0048] 1. Apparatus disclosed herein

[0049] 2 Base

[0050] 3. Lid

[0051] 4 Hinges

[0052] 5 Longitudinal edge of the base

[0053] 6 Longitudinal edge of the lid

[0054] 7 Cylindrical void

[0055] 8. Handle

[0056] 9 Mounting plate

[0057] 10 Bolts

[0058] 11 Bolt

[0059] 20 Prior Art Devices

[0060] 21 Base

[0061] 22 Lid

Claims

1. A device (1) for producing a hollow fiber membrane bundle, comprising: A base (2) having a groove in the shape of a cylindrical portion; as well as a rigid cover (3) whose bottom surface has the shape of a cylindrical portion and is connected to the base (2) by at least one hinge (4) so ​​that the cover (3) is movable between a first position and a second position, wherein the device (1) is configured to receive a plurality of hollow fiber membranes when the cover (3) is in a first position, and when the cover (3) is in a second position, the base (2) and the cover (3) together form a cylindrical void (7), The invention is characterized in that the base (2) and the cover (3) both have longitudinal edges (5, 6) in the form of a periodic curve oscillating around a mean value, wherein when the cover (3) is in the second position, the base (2) and the cover (3) are in contact with each other, and the periodic curve is selected from i. a cosine curve A*cos(x) having maximum values ​​at both ends of the device (1), ii. the arccosine curve A*(-cos(x)), which has minimum values ​​at both ends of the device (1), iii. a sinusoidal curve A*sin(x), wherein the amplitude of the curve corresponds to the average value at the two ends of the device (1), or iv. Periodic curves, which consist of successive circular or elliptical segments in alternating orientations.

2. A device (1) according to claim 1, wherein the periodic curve consists of alternatingly oriented consecutive circular segments with the same radius.

3. The device (1) according to claim 2, wherein the radius is 10 mm to 30 mm.

4. The device (1) according to any one of claims 1 to 3, wherein the length of the device (1) corresponds to an integer number of periods of the periodic function.

5. The device (1) according to claim 4, wherein the number of cycles is 2 to 12.

6. The device (1) according to any one of claims 1 to 5, wherein the diameter of the cylindrical interspace (7) is 30 mm to 50 mm.

7. The device (1) according to any one of claims 1 to 5, wherein the diameter of the cylindrical void (7) is 15 mm to 25 mm.

8. A winding wheel equipped with a plurality of devices (1) according to any one of claims 1 to 7.

9. The winding wheel according to claim 8, further comprising means for moving the cover (3) of the device (1) back and forth between the first position and the second position.

10. A method for preparing a hollow fiber membrane bundle, comprising: a) providing at least one device (1) according to any one of claims 1 to 7, wherein the cover (3) is in a first position; b) collecting a plurality of hollow fiber membranes in a tank at a base (2) of the apparatus (1) to produce a hollow fiber membrane bundle; c) then closing the lid (3) of the device (1) to confine the hollow fiber membrane bundle in the cylindrical void (7) of the device (1), and d) then cutting the hollow fiber membrane bundle at both ends of the device (1) to obtain a hollow fiber membrane bundle having a defined length.

11. The method according to claim 10 uses a plurality of devices (1) according to any one of claims 1 to 7 installed on the periphery of a winding wheel to simultaneously produce a plurality of hollow fiber membrane bundles, wherein a plurality of hollow fiber membranes are introduced into each device (1) by winding the wire of the hollow fiber membrane onto the winding wheel and rotating the winding wheel so that it enters the groove of the base (2) of the device (1); and then the hollow fiber membranes are cut between the individual devices (1).

12. The method according to claim 11, wherein the winding wheel is equipped with a mechanism configured to mechanically close or open the lid (3) of each device (1) as the winding wheel rotates, as required for each process step.

Images