EP4326425A1

EP4326425A1 - Device and method for bundling hollow fibre membranes

Info

Publication number: EP4326425A1
Application number: EP22721097.8A
Authority: EP
Inventors: Paul Gastauer; Franz Kugelmann; Michael Paul; Andreas Ruffing; Tobias VEIT
Original assignee: Fresenius Medical Care Deutschland GmbH
Current assignee: Fresenius Medical Care Deutschland GmbH
Priority date: 2021-04-22
Filing date: 2022-04-21
Publication date: 2024-02-28
Also published as: JP2024514655A; CN117255712A; KR20240000488A; AU2022261402A1; DE102021110264A1; WO2022223721A1; CA3217166A1

Abstract

The invention relates to a device and a method for producing a hollow fibre membrane bundle consisting of hollow fibre membranes, wherein, in the claimed device, a sheaf of hollow fibre membranes is received in a lower semitubular shell and bundled together to form a hollow fibre membrane bundle by a complementary upper semitubular shell.

Description

Device and method for bundling hollow fiber membranes

THEME

The present invention relates to a device and an arrangement for bundling hollow-fiber membranes, and a method for bundling hollow-fiber membranes using said device.

BACKGROUND

[0002] Hollow fiber membrane filters are used in the purification of liquids. In particular, hollow-fiber membrane filters are used in medical technology for the treatment and decontamination of water and in the therapy of patients with kidney damage in extracorporeal blood treatment as dialyzers or haemofilters. The hollow-fiber membrane filters generally consist of a cylindrical housing and a plurality of hollow-fiber membranes arranged therein, which are cast at the ends in the housing with a casting compound in a casting zone and are connected to the housing in a sealing manner. As is known, such hollow-fiber membrane filters are often designed in such a way that they are operated in the countercurrent process of two liquids, so that a particularly efficient mass transfer can take place via the membrane wall of the hollow-fiber membranes and a desired purification of one of the liquids takes place. For this purpose, the hollow-fiber membrane filters are structurally designed in such a way that the lumina of the hollow-fiber membranes form a first flow space and a first liquid flows through them, and the spaces between the hollow-fiber membranes in the housing of the hollow-fiber membrane filter form a second flow space through which a second liquid can flow. Inflow or outflow chambers are located at the end regions of the hollow-fiber membrane filter, which have liquid accesses in order to introduce and discharge the first and the second liquid into the respective flow spaces of the hollow-fiber membrane filter.

The production of such hollow-fiber membrane filters is initially preceded by the production of the hollow-fiber membranes. Hollow fiber membranes are made in a spinning process manufactured. In the process that is predominantly used, a spinning mass is provided which consists of a polymer solution which has a solvent and polymers dissolved therein, for example polysulfone and polyvinylpyrrolidone. The spinning mass is extruded through an annular die into a spinning thread, which is introduced into a precipitation bath and precipitated into a hollow-fiber membrane. The resulting hollow-fiber membrane is passed through further rinsing baths and drying zones and then combined on a reel to form a family of hollow-fiber membranes. For the production of the hollow-fiber membrane filter, the multitude of coiled-up hollow-fiber membranes is bundled and lengthened to predetermined lengths. Cover foils, which are placed around the set of hollow-fiber membranes, are usually used for the bundling. The hollow-fiber membranes are compressed in the envelope of the films and can thus be used as hollow-fiber membrane bundles in further production processes. The cover films are polymer films such as polyethylene or PTFE films or low-friction coated films, in particular, for example, special films coated with PTFE or polyolefin. The cover foils are placed and fixed around the hollow-fiber membranes using folding techniques and/or welding processes. The hollow fiber membrane bundle automatically assumes a cylindrical shape.

In a further step, the bundles of hollow-fiber membranes wrapped in the films are pushed into the cylindrical housing of the hollow-fiber membrane filter. The cover film is then pulled out of the housing again, the hollow-fiber membranes being simultaneously held in place by a suitable tool against the tension of the cover film and remaining in the housing of the hollow-fiber membrane filter. The outer diameter of the bundle of hollow-fiber membranes wrapped in the wrapping film is usually smaller than the inner diameter of the cylindrical housing. It is particularly important that the bundle of hollow-fiber membranes is compressed by the wrapping of the cover film. The hollow-fiber membrane bundle is thus stiffened and can thus be inserted into the cylindrical housing. When the cover film is pulled out of the cylindrical housing, the hollow fiber membrane bundle adapts to the inner diameter of the cylindrical housing. [0005] In the course of the production process, further steps follow in which the ends of the hollow-fiber membranes are closed by melting them off or by applying a pre-casting. The hollow fiber membranes are then cast in the cylindrical housing at the end areas and fixed in the housing. After the encapsulation has hardened, the lumens of the hollow-fiber membranes are exposed again by cutting through the encapsulation compound at the end. In a further step, end caps with liquid connections are placed on the cylindrical housing, so that the first and the second flow space and the inflow or outflow chambers are formed. The hollow-fiber membrane filter produced in this way is then sterilized and subjected to further process steps, for example a leak test.

DE 20 2017 104 293 U1 describes a system for producing a hollow-fiber membrane filter, including, among other things, a device for inserting a hollow-fiber membrane bundle into a housing of a hollow-fiber dialyzer and a device for closing the ends of the hollow-fiber membranes, the device for inserting a hollow-fiber membrane bundle into the Housing a gripper and a pressure mechanism and the means for closing the ends of the

Hollow fiber membranes have a source of electromagnetic waves.

[0007] EP 3 600 630 B1 describes the production of hollow-fiber membrane bundles using magnetically sealable envelope films.

WO 2018/178124 A1 describes a winding wheel for the production of

hollow fiber membrane bundles. The winding wheel has a plurality of devices, each having a base with a semi-cylindrical chute for receiving an envelope film and a plurality of hollow fiber membranes, and flaps attached to the bases which are movably supported by hinges, with the flaps toward the semi-cylindrical chute have a cylinder segment shape. The hollow-fiber membranes are folded into the envelope film by closing the flaps and cut between the respective devices to form hollow-fiber membrane bundles that have been cut to length. A disadvantage of the methods described in the prior art for bundling hollow-fiber membranes is the use of envelope films. In an automated manufacturing process, the use of cover foils requires the use of complex machine-side devices, or else requires that certain process steps have to be carried out manually. In addition, the use of the specially coated cover films in large-scale processes also represents a significant cost factor. In addition, the use of the cover films requires individual process steps, e.g. wrapping the hollow-fiber membranes in the film or sealing the cover film, which completes the bundling process and the Making the manufacture of the hollow fiber membrane filter complicated in terms of process technology.

The object on which the invention is based was therefore to further improve the production of hollow-fiber membrane filters in terms of process technology and costs by optimizing the bundling of the hollow-fiber membranes.

SUMMARY OF THE INVENTION

In a first aspect, the object is achieved by a device having the features of claim 1. The features of claims 2 to 11 describe preferred embodiments.

In a second aspect, the object is achieved by an arrangement having the features of claim 12. The features of claims 13 and 14 describe preferred embodiments.

In a third aspect, the object is achieved by a method having the features of claim 15 using a device having the features of the first aspect. The features of claims 16 to 19 describe preferred embodiments.

In a fourth aspect, the object is achieved by using a device according to the features of claims 1 to 11 or an arrangement according to solved the features of claims 12 to 14 in the manufacture of a hollow fiber membrane filter.

DESCRIPTION OF THE INVENTION

In a first aspect, the invention relates to a device for bundling hollow-fiber membranes, having a lower part, having a lower half-shell tube with two side edges and an inner side, which has a concavely curved surface for receiving a group of hollow-fiber membranes, an upper part having a lower half-pipe complementary upper half-pipe with two side edges and an inner side, which has a concavely curved surface, wherein the lower part and/or the upper part are arranged in the device such that they can be moved relative to one another, and wherein the device is configured in such a way that the lower part and the upper part are in a first position from one another are spaced apart so that the lower half-pipe shell can accommodate a group of hollow-fiber membranes in the first position, and the lower part and upper part are in a second position in relation to one another such that the lower half-pipe shell and the upper half-pipe shell enclose a cavity, so that ss a group of hollow-fiber membranes present in the cavity can be bundled

The device has the advantage that in the second position of the lower part and upper part through the cavity formed by the lower and the upper half-pipe shell, a family of hollow-fiber membranes is bundled and can be fed to further process steps as a hollow-fiber membrane bundle. In particular, the use of an envelope film can be dispensed with, since the necessary compression for producing the hollow-fiber membrane bundle is already produced via the lower and the upper half-shell of the tube. Therefore, in the production of hollow-fiber membrane filters, there is no need for equipment on the machine side that would otherwise have to be provided for wrapping and sealing the envelope film around the hollow-fiber membrane bundle. The terms "lower part and upper part" describe two interacting components in the function of the device according to the invention. In a preferred embodiment, the lower part and the upper part can be arranged in such a way that the lower part is closer to the center of gravity. Alternatively, the lower part and upper part can also be in a different position in the device, e.g. so that the lower part and the upper part are equally close to the center of gravity , or so that the bottom is farther from the center of gravity than the top.

[0018] In the context of the present application, the term “pipe half-shell” is understood to mean a half-shell that describes a pipe segment that is produced by a longitudinal section of a pipe. In a cross-section transverse to the longitudinal orientation, the pipe half-shells can have a contour that approximates a segment of a circle. The term "half" in half-pipe does not necessarily mean that the half-pipes are in the form of a segment of an exact half of a pipe. In particular, the lower half-pipe can also be a pipe segment that represents more than half of a pipe, or the upper half-pipe can be a pipe segment that represents more than half of a pipe. The pipe half-shells have concavely curved surfaces. In the context of the present application, the term “concave” is to be understood as meaning a surface in which a straight line between any selectable points on this surface runs completely outside the half-shell of the pipe. In particular, the lower and upper half-shells are designed to complement each other. The term "complementary ^M " means in this context that the lower half-pipe and the upper half-pipe form a tubular cavity in the second position of the lower part and upper part, which is used to bundle a group of hollow-fiber membranes and to put them in a compressed state. The term “compressed” means that the group of hollow-fiber membranes is compressed to a spatial extent and bundled by the application of a force, and the bundle produced in this way develops a restoring force.

In a first position, the upper and lower parts are spaced apart from one another, which means that the insides of the half-shells are accessible and, for example, a group of hollow-fiber membranes can be inserted into the lower half-shell of the tube. The device described here can, for example, be part of a reel on which the Hollow-fiber membranes are wound up, with a group of hollow-fiber membranes being inserted into the lower half-shell of the tube as a result of the winding process. Alternatively, the group of hollow-fiber membranes can also be inserted into the device described here in the form of one or more strands of hollow-fiber membranes. The term “strand” is understood here to mean a large number of hollow-fiber membranes which are aligned with one another in a uniform preferred direction. In this context, the term “group of hollow-fiber membranes” is to be understood as meaning a large number of hollow-fiber membranes, which consist, for example, of one or more strands laid together. In particular, the term "group" also refers to the number of hollow-fiber membranes that are combined into a bundle.

In the second position, the lower part and the upper part are in relation to one another in such a way that the lower half-pipe and the upper half-pipe enclose a cavity. In particular, the lower part and the upper part can be in engagement with one another in the second position. In this context, the term "intervention" means that the lower part and the upper part connect to one another, so that the lower half-pipe and the upper half-pipe enclose a cavity. In one embodiment, the engagement can come about in that the lower part has a receiving area for the upper part, in which the upper part adjoins in a form-fitting manner. By moving the lower part and the upper part relative to one another in the device, the upper part is inserted into the receiving area of the lower part and the cavity is enclosed by the lower and upper half-shells of the pipe. In an alternative embodiment, the engagement can also come about in that the upper part has a receiving area for the lower part, in which the lower part adjoins in a form-fitting manner. By moving the lower part and the upper part relative to one another in the device, the lower part is inserted into the receiving area of the upper part and the cavity is enclosed by the lower and upper half-pipe shells.

In one embodiment, the device is characterized in that the concavely curved surface of the lower half-pipe describes a segment of a substantially cylindrical shape, the concavely curved surface of the upper half-pipe describes a segment of a substantially cylindrical shape, so that the concavely curved surfaces of the lower and upper pipe half-shells enclose a substantially cylindrical cavity in a second position of the lower part and the upper part.

The hollow-fiber membrane bundle enclosed in the cavity is given a cylindrical shape via the cylindrical cavity formed from the lower half-shell and the upper half-shell of the tube and can thus advantageously be used for the construction of hollow-fiber membrane filters with a cylindrical housing.

In a further embodiment, the device is characterized in that the lower half pipe is oversized compared to the upper half pipe in the area of the side edges of the lower half pipe, or that the upper half pipe is oversized compared to the lower half pipe in the area of the side edges of the upper half shell wherein the device is configured such that in the second position of the lower part and upper part the upper half pipe is in engagement with the lower half pipe, or that in the second position of the lower part and upper part the lower half pipe is in engagement with the upper half pipe.

The embodiment described ensures that in the second position of the upper part and lower part, a half pipe shell can engage in the area of oversize of the other half pipe shell. It is thus possible to further compact the group of hollow-fiber membranes in the enclosed cavity between the upper and lower half-shell of the pipe. In this context, the term "compact" means that the hollow-fiber membrane bundle can be further compressed in the cavity.

In a further embodiment, the device is characterized in that the side edges of the upper half-pipe and/or the lower half-pipe are chamfered. In particular, hollow-fiber membranes that are in contact with the surface adjacent to the side edges of a respective half-pipe shell are stripped off by the bevel and are thus effectively shifted within a range within an intended compression diameter. This achieves a higher compression of the hollow-fiber membrane bundle between the upper and lower half-shell of the tube. For example, the chamfers on the side edges of the upper half shell cause this Hollow-fiber membranes, which rest on the surface of the lower half-pipe shell adjacent to the side edges of the lower half-pipe shell, are shifted into the lower shell in the range of an intended compression diameter.

In a further embodiment, the device is characterized in that the concave curved surfaces of the lower and / or the upper half pipe shell has a plurality of bores, and the device is configured to air through the bores on the inside of the lower and / or flow in or suck off the upper pipe half-shell.

[0027] The bores can branch off from a ventilation duct which is located in the lower part and/or upper part of the device. In one embodiment, the lower part has at least two gas connections that are connected to the ventilation channel. Via the gas connections, the ventilation channel and the large number of bores, an air flow can be directed to the inside of the respective half-pipe shells, thus supporting the bundling of the hollow-fiber membranes and the further processing of the hollow-fiber membrane bundle. In particular, the supplied air flow forms an air cushion between the hollow fiber membrane bundle and the surface of the lower and/or upper half-shell of the tube, and the friction of the hollow-fiber membranes on the surfaces of the half-shell of the tube is reduced. The air flow supports the removal of a hollow-fiber membrane bundle from the cavity formed by the upper and lower half-shell of the tube, so that the risk of damage to the hollow-fiber membranes is reduced.

In a further embodiment, the device is characterized in that at least some of the bores, preferably all of the bores in the lower and/or upper half pipe shell, are aligned in a preferred direction, in particular at a matching angle of 10° to 80°, or 20° to 70° or 30° to 60° to the central axis of the cylindrical cavity.

In the arrangement of the aligned bores in a preferred direction, a flow direction of the inflowing air arises on the inside of the lower and/or upper half pipe shell. The direction of air flow on the insides of the Pipe half-shells support in particular the removal of the hollow-fiber membrane bundle from the cavity of the lower and upper pipe half-shells in the flow direction of the air flow.

In a further embodiment, the device is characterized in that the concavely curved surfaces of the lower and/or upper half-pipe shells are provided with a coating. The coatings reduce the friction between the surface and the adjacent hollow-fiber membranes. In particular, the coatings can be plastic coatings, e.g., coatings of PTFE (polytetrafluoroethylene) or other fluorinated polymers with a low coefficient of friction. Alternatively, the surfaces can also be coated with polyolefins. In a further alternative embodiment, the surfaces can also be provided with a low-friction ceramic coating or, for example, a DLC (diamond-like carbon) coating.

In a further embodiment, the device is characterized in that the device has at least one movable cutting device in order to lengthen the hollow-fiber membrane bundle in the second position of the upper part and lower part to a predetermined length. At least two cutting devices can advantageously be movably arranged in the device. The device is configured in such a way that in the second position of the lower part and upper part the hollow-fiber membranes protruding from the cavity of the lower and upper half-shell of the pipe are cut. As a result, the bundle of hollow-fiber membranes is brought to a length which is intended for the insertion of the bundle of hollow-fiber membranes into the housing of a hollow-fiber membrane filter. The cutting device may comprise a mechanical cutting tool such as a blade.

Alternatively, the cutting device can have a thermal cutting tool, ie in particular a cutting tool in which the ends of the hollow-fiber membranes are severed by melting with a hot wire, a hot blade or a laser beam. The ends of the hollow-fiber membranes are preferably melted off in such a way that the lumina of the hollow-fiber membranes are closed. This has the advantage that in the manufacturing process Hollow fiber membrane filter can be dispensed with the process step of Vorverguss. At the same time, the hollow-fiber membrane bundle is mechanically stabilized by the melting of the hollow-fiber membranes in the end area. The hollow-fiber membrane bundle can thus be handled more safely in the further manufacturing process of the hollow-fiber membrane filter.

In a further embodiment, the device is characterized in that the device has a receiving unit for a housing tube, which is arranged in the device movably relative to the lower part and/or the upper part, and the device is further configured such that in the second position of the upper part and lower part via a position of the receiving unit, a housing tube can be arranged on the end face of the lower and upper tube half-shells. The relative movement of the receiving unit to the upper and/or lower part is decisive, i.e. it can also be provided that the receiving unit is designed to be stationary and the relative movement is carried out via the upper and/or lower shell. The hollow-fiber membrane bundle can thus be inserted directly from the cavity of the lower half-shell of the tube and the upper half-shell of the tube into a subsequently arranged housing tube. The subsequently arranged housing tube is preferably the cylindrical housing of a hollow-fiber membrane filter. In a further embodiment, the device is characterized in that the device has means for inserting the hollow-fiber membrane bundle from the cavity into the housing tube adjoining the end face. The insertion of the hollow-fiber membrane bundle into the adjoining housing tube is preferably effected by a movable expeller with which the hollow-fiber membrane bundle can be pushed out of the cavity made up of the lower and upper half-shells into the housing tube arranged subsequently.

Preferably, the diameter of the cavity made up of the lower and upper half-shells of the pipe in the second position is at least 2%, preferably at least 5%, more preferably at least 7% less than the diameter of the housing pipe. Due to the smaller diameter, moving the hollow-fiber membrane bundle into the housing tube is particularly simplified. In a particular embodiment, the housing tube has a tapered center portion. This means that the inner diameter of the middle part of the casing tube has a smaller diameter than the inner diameters at the ends of the casing tube. In such embodiments of the housing tube, the inner diameter preferably decreases from the ends to the central part. Such a housing tube or hollow fiber membrane filter housing is identified by the term "tapered design" or "tapered central tube". In this case, it is provided that the end of the housing tube, which in the second position of the upper part and lower part is arranged on the face side adjoining the lower and upper half tube shell, has a diameter that is at least 2%, preferably at least 5%, more preferably at least 7% larger than the diameter of the cavity from the lower and upper half-shells in the second position.

In a second aspect, the invention relates to an arrangement comprising a device according to the first aspect of the invention and a hollow-fiber membrane bundle, which is located in the device in the cavity formed from the lower and upper half-pipe shell. Neither the bundle of hollow fibers nor the device has an envelope film. In one embodiment, the arrangement further comprises a housing tube which, in the second position of the upper part and lower part, is arranged at the front end of the lower and upper half-pipe shells, with the diameter of the bundle of hollow fibers, which is located in the cavity, being at least 2%, preferably at least 5 %, more preferably at least 7%, is less than the diameter of the housing tube. In another embodiment, the arrangement further comprises a housing tube with a tapered middle part, wherein the diameter of the hollow fiber bundle, which is located in the cavity, is at least 2%, preferably at least 5%, more preferably at least 7% less than the diameter of the end of the housing tube, which in the second position of the upper part and lower part is arranged on the front side adjoining the lower and upper half-shell of the tube.

In a third aspect, the invention relates to a method for bundling hollow-fiber membranes, comprising the steps: providing a device according to at least one embodiment of the first aspect of the invention, introducing a group of hollow-fiber membranes into the lower half-shell of the tube in the first position of the upper part and bottom of the device, relatively moving the top and bottom into the second Position, so that the family of hollow-fiber membranes are bundled into a hollow-fiber membrane bundle in a cavity formed from the lower and the upper half-pipe shell. In this case, the hollow-fiber membrane bundle is preferably also compressed. According to the method according to the invention, the hollow-fiber membranes are bundled without using a wrapping film. The bundle of hollow-fiber membranes present in the cavity is preferably already compressed to an extent that can be used for further use in the production of a hollow-fiber membrane filter. In one embodiment, the hollow-fiber membrane bundle is compressed to a packing density of greater than 60%, in particular greater than 64%, more particularly greater than 66%. In the context of the present application, “packing density” is understood as meaning the proportion in the cavity formed from the lower and upper half-shells of the pipe that is occupied by the hollow-fiber membranes. The packing density is calculated from the percentage ratio of the sum of the cross-sectional areas of the hollow-fiber membranes to the cross-sectional area of the cavity formed from the lower and upper half-shells.

In a further embodiment, the method is characterized in that the hollow-fiber membrane bundle is lengthened to a predetermined length with a cutting device in the second position of the upper part and lower part. In a further embodiment, the method is further characterized in that the cutting device is a hot-cutting tool that melts the ends of the hollow-fiber membranes when cutting them to length and closes the lumina of the hollow-fiber membranes. The length of the hollow-fiber membrane bundle is thus adjusted to a dimension necessary for the further production of the hollow-fiber membrane filter.

In a further embodiment, the method is characterized in that a cylindrical housing tube is positioned adjacent to the cavity formed by the lower and upper half-shells and the hollow-fiber membrane bundle is pushed into the adjacent cylindrical housing tube. The hollow-fiber membrane bundle is pushed out of the cavity by an ejector, which is pushed into the cavity and in the process pushes the hollow-fiber membrane bundle in the direction of the adjacently arranged housing tube. The housing tube is in particular a cylindrical tube, in particular the cylindrical housing a hollow fiber membrane filter. It is preferably provided that the hollow fiber bundle in the hollow space formed by the lower and the upper half pipe shell is compressed by at least 2%, preferably at least 5%, more preferably at least 7% more than a hollow fiber bundle pushed into the housing pipe. Due to the greater compression, the insertion of the hollow-fiber membrane bundle into the housing tube is particularly simplified. If the housing tube has a tapered central part, it is provided that the hollow fiber bundle in the cavity formed by the lower and upper tube half shells is compressed by at least 2%, preferably at least 5%, more preferably at least 7% more than a hollow fiber bundle at the end of the housing tube, which in the second position of the upper part and lower part of the device is arranged on the front side adjoining the lower and upper half-shell of the tube.

In a further embodiment, the method is characterized in that air flows against the inside of the lower and/or upper half pipe shell through the plurality of bores. By the air flowing against the inside, an air cushion is created between the surface of the lower and/or upper half-shell of the tube and the hollow-fiber membranes lying against the surface of the half-shell of the tube. At least some of the bores or all of the bores are preferably aligned in a preferred direction, so that the flow of air onto the inner sides of the pipe half-shells assumes a preferred flow direction. In particular, this supports the process of pushing the hollow-fiber membrane bundle out of the device. The hollow-fiber membrane bundle is pushed out in the direction of the preferential flow direction of the inflowing air.

In a fourth aspect, the invention relates to the use of a device or arrangement according to at least one embodiment of the first or second aspect of the invention for the production of a hollow-fiber membrane filter.

DETAILED DESCRIPTION OF THE INVENTION USING THE DRAWINGS

Fig. 1a shows a schematic representation of a cross-sectional view of the lower part 101 and the upper part 120. The cross-section shown runs transversely to the longitudinal orientation of the lower part and the upper part. Not shown in Fig. 1a are further details of the device, the components of which are the lower part and the upper part. 1a shows the lower part and the upper part in a first position, in which the lower part and the upper part are spaced apart. A representation is shown in which the upper part is arranged over the lower part. However, other arrangements of the lower and upper parts in the first position are also possible. Alternatively, the upper part can also be arranged next to the lower part in the first position. In the illustration shown in FIG. 1a, the lower half pipe shell 102 is shown in a cross section. The cross-section of the lower half-shell of the pipe is in the form of a segment of a circle between the side edges 103a and 103b, which are only visible in schematic cross-section in FIG. 1a. The lower half shell of the tube has an inner surface 104 adapted to receive a family of hollow fiber membranes, not shown in Figure 1a. Furthermore, gas connections 106a and 106b are visible on the lower part 101, via which a gas flow, in particular an air flow, can be fed into and out of a ventilation duct (not shown in FIG. 1a) in the interior of the lower part 101. The concavely curved surface of the lower half-pipe shell is denoted by 105 in FIG. 1a. It can only be seen as a segment of a circle in cross section in FIG. 1a. In the illustration shown, the lower part 101 also has a receiving area 107 for receiving the upper part 120 .

The upper part 120 has an upper half-pipe shell 121 which is complementary to the lower half-pipe shell 101 . In the representation shown, the cross section of the upper half-pipe shell is in the form of a segment of a circle in one section. The concavely curved surface of the upper pipe half-shell is denoted by 124 in FIG. 1a. The side edges 122a and 122b are visible only schematically in cross section in FIG. 1a. The bevels of the side edges are denoted by 127a and 127b. Also shown are a holding element 126a, with which the upper part is held in the device, and a gas connection 125a, with which a gas, in particular air, is fed into and out of a ventilation duct inside the upper part 120 and via bores (not shown in Fig. 1a) can be flowed onto the inside 123 of the upper pipe section.

Fig. 1b shows a schematic representation of an oblique side view of the lower part 101 and upper part 120 in the first position. Compared to Fig. 1a are further shown a second support member 126b, with the upper part 120 in the Device is held, a second gas connection 125b on the upper part and a third gas connection 106c on the lower part as well as bores 108 in the surface 105 of the lower half pipe shell 102.

Fig. 2a shows a schematic representation of the lower part 101 and the upper part 120 of the device, in which the lower part and the upper part are in engagement with one another in the second position. Compared to the illustration from FIG. 1a, the cavity 130 formed is shown as essentially circular in the cross-sectional illustration, so that the cavity itself is essentially cylindrical. Contrary to the illustration in FIG. 1a, the upper part 120 is located in the receiving area 107 of the lower part. In the illustration shown, the lower half-pipe shell 102 has an oversize at the side edges 103a and 103b compared to the upper half-pipe shell 120 at the side edges 122a and 122b. When the upper part is lowered, the side edges 122a and 122b of the upper half-pipe shell with the chamfers 127a and 127b can advance to the inside 104 of the lower half-pipe shell 101 . According to FIG. 2a, the side edges 122a and 122b rest against the surface 105 of the lower half-shell 102 of the pipe. Hollow-fiber membranes (not shown in FIG. 2a), which are in contact with the surface 105 of the lower half-shell 102, are stripped off via the bevels 124a and 124b. Lowering the top compresses the family of hollow fiber membranes in cavity 130 . Alternatively, there can be minimum gap dimensions of less than a hollow-fiber membrane diameter between the side edges 122a and 122b and the surface 105 of the lower half-pipe shell 102 .

FIG. 2b shows a side view corresponding to FIG. 2a of the lower part and upper part in the second position.

3 shows a cross-sectional view of a device 100 with a lower part 101 and an upper part 120 in a second position, in which the lower part 101 and upper part 120 are in engagement with one another. In the cross-sectional view, the bores 108 in the surface 105 of the lower half-pipe shell 102 are shown schematically. 3 shows a lifting device 140 with which the upper part 120 can be brought from a first position into a second position via the holding elements 126a and 126b. Also shown schematically is an expeller 150, which according to an embodiment corresponding to FIG. 3 is movable. Also shown in FIG. 3 is a receiving unit 160 which receives a cylindrical housing tube 170 . The receiving unit is a movable component with which a housing tube, in particular a cylindrical housing tube, can be arranged in the second position shown, adjoining the lower and upper tube half-shells at the front.

example

The bundling according to the invention of a group of hollow-fiber membranes is explained with reference to the embodiments shown in FIGS. 1a to 3. First, a family of hollow-fiber membranes is introduced into the lower half-shell 102 of the tube in the first position of the lower part 101 and upper part 120 . The radius of the lower and upper tube half-shells (102, 121) is dimensioned in such a way that a predetermined number of hollow-fiber membranes can be bundled into a hollow-fiber membrane bundle. A hollow-fiber membrane customary for hemodialysis is used. This has an outside diameter of 261 μm. The hollow-fiber membrane used is textured, i.e. the hollow-fiber membrane has a waveform known in the prior art with an amplitude of 0.41 mm and a wavelength of 7.5 mm. For the production of a hollow-fiber membrane filter, 8448 of these hollow-fiber membranes are introduced into the lower half-shell of the tube of the lower part of a device according to the invention. The diameter of the concavely curved surface of the half pipe shell is 29 mm.

In a next step, the upper part 120 is displaced in the device 100 in the direction of the receiving area 107 of the lower part until the upper half-pipe shell 121 and the lower half-pipe shell 102 enclose a cavity 130 which, according to the example explained here, is essentially cylindrical. The upper part is displaced into the receiving area 107 of the lower part 101 until the group of hollow-fiber membranes in the hollow space 130 forms a cylindrical bundle with a diameter of approx. 29 mm. In this compressed state, the hollow fiber membrane bundle has a packing density of 68.4%. In this context, the packing density is understood to be the ratio of the sum of all cross-sectional areas of the 8448 hollow-fiber membranes to the cross-sectional area of the essentially cylindrical cavity 130 . Following the hollow fiber membrane bundle with a Cutting tool lengthened to a length predetermined for the construction of hollow fiber membrane filters.

In a further step, air flows against the insides 104 and 123 of the lower and upper pipe half-shells 102, 121 via the gas connections 125a/b and 106a-c. A cylindrical housing tube is positioned at the end adjacent to an opening side 180a of the cavity 130 formed from the upper and lower tube half-shells via the receiving unit 160 . An expeller 150 is positioned on the opposite opening side 180b. The expeller 150, which is movable in longitudinal alignment with the tube half shells, is set in motion and pushes the hollow fiber membrane bundle out of the cavity 130 into the adjacent cylindrical housing tube 160. In a preferred embodiment, the cylindrical housing tube is the housing of a hollow fiber membrane filter. Alternatively, another housing tube can also be used, into which the hollow-fiber membrane bundle is pushed, so that the hollow-fiber membrane bundles can be removed from the device piece by piece.

The cylindrical housing tube can accordingly be a housing of a hollow fiber membrane filter which has an inner radius of 31 mm. The packing density of the hollow fiber membrane bundle in the cylindrical tube is then 59.9%.

Alternatively, a thin-walled metal tube can also be used and the hollow-fiber membrane bundle pushed out of the cavity 130 into the thin-walled metal tube. In this case, the thin-walled metal tube has an inner radius of 15 mm and an outer radius of 15.4 mm. The hollow-fiber membrane bundle can thus first be pushed into the thin-walled metal tube. For the further production of a hollow fiber membrane filter, the thin-walled metal tube is pushed into the housing of a hollow fiber membrane filter with an inner radius of 15.5 mm. The metal tube is then pulled out of the housing of the hollow-fiber membrane filter, with the hollow-fiber membrane bundle being held against it and remaining in the housing of the hollow-fiber membrane filter. Housings with integrated hollow-fiber membrane bundles are then fed to further process steps of hollow-fiber membrane filter production.

Claims

PATENT CLAIMS

1. Device (100) for bundling hollow-fiber membranes, having a lower part (101) having a lower half-pipe shell (102) with two side edges (103a, 103b) and an inner side (104) having a concavely curved surface (105) for receiving a family of hollow-fiber membranes, an upper part (120) having an upper half-shell (121) complementary to the lower half-shell (102) with two side edges (122a, 122b) and an inner side (123) which has a concavely curved surface (124), wherein Lower part (101) and/or upper part (120) are arranged in the device (100) so that they can be moved relative to one another, and wherein the device (100) is configured in such a way that

Lower part (101) and upper part (120) are spaced apart from one another in a first position, so that the lower half-pipe shell (102) can accommodate a group of hollow-fiber membranes in the first position and

The lower part (101) and the upper part (120) are in a second position relative to one another in such a way that the lower half-pipe shell (102) and the upper half-pipe shell (121) enclose a cavity (130), so that a group of hollow-fiber membranes present in the cavity (130). can be bundled.

2. Device according to claim 1, characterized in that the concavely curved surface (105) of the lower half-pipe (102) describes a segment of a substantially cylindrical shape and that the concavely curved surface (124) of the upper half-pipe (121) describes a segment of a describes a substantially cylindrical shape, so that the concavely curved surfaces (105, 124) of the lower and upper pipe half-shells (102, 121) in a second position of the lower part (101) and upper part (120) form a substantially cylindrical cavity (130) enclose.

3. Device according to claim 1 or 2, characterized in that the lower half pipe shell (102) is oversized compared to the upper half pipe shell (121) in the area of the side edges (103a, 103b) of the lower half pipe shell (102), or that the upper half pipe shell (121) is oversized compared to the lower half-pipe shell (102) in the area of the side edges (122a, 122b) of the upper half-pipe shell (121), the device being configured such that in the second position of the lower part (101) and upper part (120 ) the upper half pipe shell (121) is in engagement with the lower half pipe shell (102), or that in the second position of the lower part (101) and upper part (102) the lower half pipe shell (102) is in engagement with the upper half pipe shell (121).

4. The device according to at least one of the preceding claims, characterized in that the side edges (122a, 122b, 103a, 103b) of the upper half-pipe (121) and/or the lower half-pipe (102) are chamfered.

5. Device according to at least one of the preceding claims, characterized in that the concavely curved surfaces (105, 124) of the lower and/or the upper half pipe shell (102, 121) have a large number of bores (108), and the device is configured , Air to flow through the holes on the inside (104) of the lower and / or upper half pipe shell (102, 121).

6. Device according to claim 5, wherein at least some of the bores, preferably all bores (108) in the lower and/or upper half pipe shell (102, 121) are aligned in a preferred direction, in particular at a matching angle of 10° to 80° or 20° to 70° or 30° to 60° to the central axis of the cylindrical cavity.

7. Device (100) according to at least one of the preceding claims, characterized in that the concave curved surfaces (105, 124) of the lower and/or upper pipe half-shells (102, 121) are equipped with a coating.

8. Device (100) according to at least one of the preceding claims, characterized in that the device (100) has at least one movable cutting device in order to cut the hollow-fiber membrane bundle in the second position of the upper part (101) and lower part (120) to a predetermined length lengths.

9. Device (100) according to at least one of the preceding claims, characterized in that the device (100) has a receiving area (160) for a housing tube (170) which is relative to the lower part (101) and/or to the upper part (120) is movably arranged in the device (100), and the device is also configured such that in the second position of the upper part and lower part, a housing tube (170) is attached to the front side of the lower (102) and upper tube half-shell via a position of the receiving area (160). (121) can then be arranged.

10. The device (100) according to claim 9, characterized in that the device has means (150) for inserting the hollow-fiber membrane bundle from the cavity consisting of the upper (121) and lower tube half-shell (102) into a housing tube (170) arranged on the end face.

11. An arrangement comprising a device (100) according to at least one of the preceding claims and a cavity (130) formed in the device from the lower and upper half-pipe shell (102, 121).

Hollow fiber membrane bundle, characterized in that neither that

Hollow fiber bundles still have the device an envelope film.

12. Arrangement according to claim 11 further comprising a housing tube (170), characterized in that the diameter of the hollow fiber bundle, which is located in the cavity (130), is at least 2%, preferably at least 5%, more preferably at least 7% less than the diameter of the housing tube (170).

13. Arrangement according to claim 12, wherein the one housing tube is arranged on the end face of the lower (102) and upper tube half-shell (121) and has a tapered central part, characterized in that the diameter of the hollow fiber bundle, which is in the cavity (130) is at least 2%, preferably at least 5%, more preferably at least 7% less than the diameter of the end of the housing tube (170) which is arranged on the front side of the lower (102) and upper tube half-shell (121).

14. A method for bundling hollow-fiber membranes, comprising the steps:

Providing a device according to any one of claims 1 to 10,

Insertion of a group of hollow-fiber membranes in the lower half-pipe shell (102) in the first position of the upper part (120) and lower part (101) of the device, relative movement of the upper part (120) and lower part (101) into the second position, so that the group of the hollow-fiber membranes in a cavity (130) formed from the lower and the upper half-shells (102, 121) into one

Hollow fiber membrane bundle is bundled.

15. The method according to claim 14, characterized in that the

hollow-fiber membrane bundle in the second position of the upper part and lower part (101, 120) is lengthened to a predetermined length with a cutting device, in particular characterized in that the cutting device is a hot-cutting tool that melts the ends of the hollow-fiber membranes when cutting them to length and the lumen which closes the hollow fiber membranes.

16. The method according to claim 14 or 15, characterized in that a tube (170) is positioned adjacent to the cavity (130) formed by the lower and upper tube half-shells (102, 121) and the hollow-fiber membrane bundle is pushed into the adjacent tube (170).

17. The method according to at least one of claims 14 to 16, characterized in that the inside (104, 123) of the lower and / or the upper Pipe half shell (102, 121) is flowed through the plurality of holes with air.

18. The method according to at least one of claims 14 to 17, characterized in that the crowd of hollow fiber membranes is not in one

Envelope film is wrapped.

19. Use of a device according to at least one of claims 1 to 10 or an arrangement according to claim 11 in the manufacture of a hollow fiber membrane filter.