Device for substance exchange between two media

Abstract

The invention relates to a device for substance exchange, comprising a housing having at least one exchange chamber with an arrangement of a multiplicity of substance-permeable hollow fibers, in which the outer walls of the hollow fibers at the spaced-apart end regions of the hollow fibers are sealed from one another and at least in some regions in relation to a wall region of the exchange chamber by means of at least one outer sealing region consisting of a sealing means, wherein the exchange chamber is divided into two chamber regions, wherein a first exchange medium can flow around the hollow fibers on the outside in the first chamber region and a second exchange medium can flow through same on the inside in the second chamber region, wherein the first chamber region is divided into at least two sub-chambers which each comprise a partial volume of the first chamber region and between which, in the arrangement of the hollow fibers, at least one inner sealing region is formed from a sealing means contacting the walls of the hollow fibers on the outside, wherein at least one pair of two movable switching means is arranged in the first chamber region, between which the arrangement of hollow fibers is located, wherein each switching means can be brought into or out of contact with at least one inner sealing region by movement, wherein, when there is contact, the sub-chambers are separated from one another and, when there is no contact, the sub-chambers are connected fluidically in parallel. The invention also relates to a method for producing a hollow fiber bundle.

Description

[0001] Device for the exchange of substances between two media

[0002] The invention relates to a device for the exchange of substances between a first exchange medium, in particular blood, and at least a second exchange medium, in particular a gas, comprising a housing with at least one exchange chamber into which an arrangement, in particular a single arrangement of a plurality of material-permeable hollow fibers, is inserted, wherein in the arrangement of the hollow fibers the outer walls of the hollow fibers are sealed at least at the end regions of the hollow fibers spaced apart in the fiber extension direction from one another and at least partially against a wall region of the exchange chamber by means of at least one outer sealing region made of a sealing agent, wherein the exchange chamber is divided into a first and a second chamber region by the walls of the hollow fibers and by the at least one outer sealing region.wherein the hollow fibers in the first chamber area of ​​the at least one exchange chamber are open to flow of the first exchange medium in a flow direction between at least two connections of the first chamber area and the hollow fibers in the second chamber area of ​​the at least one exchange chamber are open to flow of the at least one second exchange medium in a flow direction between at least two connections of the second chamber area.

[0003] The first medium flowing in the first chamber area can be, for example, blood, and the second medium flowing in the second chamber area can be a gas or a gas mixture, preferably containing oxygen. In this application, which is also preferred for the invention, the device forms a so-called oxygenator.

[0004] However, the invention is not limited to this application. It can also provide for the exchange of substances between other media, e.g., for concentrating or purifying substances within the media. For example, blood can also be deoxygenated. Likewise, it is possible to aerate a fluid, e.g., water.

[0005] The exchange takes place in the exchange chamber, for example, a gas exchange between the two media. This exchange occurs through the walls of the hollow fibers, which are permeable to predetermined substances in the media. For example, in the case of blood and a gas / gas mixture, they are permeable to oxygen and carbon dioxide, primarily due to diffusion, but not to other blood components, such as blood plasma.

[0006] Such material-permeable hollow fibers are well known to those skilled in the art. Typical hollow fibers known from oxygenator applications are, for example, made of materials such as polypropylene (PP), polyethylene (PE), polymethylpentene (PMP), or silicone.

[0007] In the invention, the arrangement of the plurality of hollow fibers is preferably a package of stacked hollow fibers in which the hollow fibers are stacked loosely or as at least one mat in one stacking direction. When stacking, for example, several separate mat sections can be stacked, or at least one mat can be folded to arrange several layers of mats in a stacked arrangement. Stacking several mat sections has the advantage that the different sections, particularly from layer to layer, can have different angles with respect to the directions of extension of the hollow fibers.

[0008] The invention further relates to a method for producing such a hollow fiber package, particularly for a device of the type mentioned at the outset, in which a package of hollow fibers is produced in a production housing by stacking a plurality of hollow fibers in a stacking direction, in particular which – preferably in each stacking layer – are connected to form at least one mat, wherein the hollow fibers extend transversely, in particular perpendicularly to the stacking direction, and in which the production housing with the package of hollow fibers arranged therein is rotated about an axis of rotation that lies parallel to the stacking direction, preferably in a centrifuge, and in which the production housing is filled with a predetermined quantity of liquid, hardenable sealant at a radial distance, in particular a maximum radial distance from the axis of rotation, during the rotation.This creates an at least partially annular outer sealing area surrounding the axis of rotation at a distance, preferably an annular outer sealing area closed over 360 degrees, made of liquid sealant, in which the sealant contacts the outer wall of the hollow fibers, in particular forming the radial outer circumference of the package, and more preferably fixing the package radially outwards by hardening the sealant, whereby the rotation is continued until a hardening state is reached in which the sealant of the outer sealing area is inherently stable. This is achieved, for example, after exceeding the so-called pot life of the sealant.

[0009] Such methods for producing a potting layer or an outer sealing area, preferably by means of a centrifuge, are generally known.

[0010] In particular, the invention may provide that the aforementioned axis of rotation, which lies parallel to the stacking direction, is itself rotated about a further axis that is at an angle to the aforementioned axis of rotation, e.g., at an angle of 20 degrees. This also makes it possible to generate a rotation of the manufacturing housing that deviates from a pure circular shape. The term "axis of rotation" hereinafter preferably refers to the axis of rotation which lies parallel to the stacking direction and preferably also to the effective axis of rotation resulting from the rotation parallel to the stacking direction superimposed with the rotation about the further axis.

[0011] In the invention, the axis of rotation can, for example, be located outside the manufacturing housing. In this case, it is provided that the two end regions of the axially open ends of the hollow fibers are potted one after the other. This creates two outer sealing regions in succession, in particular those that are not connected to each other. Each outer sealing region forms a partial ring with a curvature corresponding to the radius of rotation.

[0012] In the invention, the axis of rotation can also be located within the manufacturing housing, e.g., centrally. In this case, both axially open ends of the hollow fibers are preferably potted simultaneously. Depending on the cross-sectional geometry of the manufacturing housing, this results in either two separate, partially annular outer sealing areas, or a single, continuous outer sealing area closed over a full 360 degrees. In both cases, the hollow fiber bundle has an internal free space in which the hollow fibers are free of sealant. This free space is part of the first chamber area. This internal free space surrounds the axis of rotation, or the axis of rotation penetrates the free space.

[0013] Such a procedure is known, for example, from publication DE 10 2019 115 162 A1 of the same applicant and also from US 5,164,081.

[0014] For the outer sealing area, it is essential in the invention that this, in conjunction with the hollow fiber walls and the wall area of ​​the exchange chamber, separates both chamber areas of the exchange chamber from each other.

[0015] The invention preferably provides that the single arrangement of hollow fibers is held together by the at least one, in particular exactly one, particularly annular outer sealing region. The single arrangement is thus also defined by all hollow fibers whose axial ends are contacted by the at least one outer sealing region.

[0016] When the manufacturing housing is rotated around an axis of rotation located in the manufacturing housing, particularly centrally, the rotation effectively takes place around a package axis of the hollow fiber package, which is parallel to the stacking direction and preferably penetrates the package centrally.

[0017] Preferably, the hollow fibers of the entire package are all oriented in the same direction; at least, the hollow fibers within a layer of stacked hollow fibers are oriented in the same direction. Therefore, there can also be different layers with different orientations of the hollow fibers. In this embodiment, preferably different layers of hollow fibers can have different orientations of extension that are oriented at 90 degrees to each other.

[0018] The package can preferably be stabilized in the manufacturing housing, e.g. by threading hollow fiber mats onto stabilizing rods or by aligning and fixing the fiber mats by stops on the fiber mat edges.

[0019] The axial ends of the hollow fibers, which are covered by the sealant during the production of the outer sealing area and preferably previously sealed, especially thermally, are reopened after the production of the outer sealing area, e.g. by partially cutting off / trimming the outer sealing area.

[0020] The arrangement of the hollow fibers at their axial end regions, sealed against the outer sealing area and at least partially against a wall of the exchange chamber (also known as a sealing chamber), achieves a division of the exchange chamber into two flow regions by the hollow fiber walls. In the first flow region, located in the aforementioned first chamber region, only the first medium flows, and in the second flow region, located in the aforementioned second chamber region, only the second medium flows. Thus, the two media do not directly contact each other but are separated by the hollow fiber wall. Subsequently, mass exchange, particularly by diffusion, can take place across the hollow fiber wall.

[0021] The entire device has flow paths to supply the first medium to one flow area / first chamber area and the second medium to the other flow area / second chamber area. The flow paths are accordingly separate.

[0022] A flow path between at least two connections, in particular between an inlet and an outlet for the first medium that contacts the hollow fiber outer walls, e.g. blood, can, for example, lead through an outer wall of the exchange chamber into this or its first chamber area.

[0023] To guide the second medium, preferably a gas or gas mixture, through the interior of the fibers, the exchange chamber is preferably surrounded in the flow direction of the second medium by two media spaces, in particular gas spaces, which are sealed to the exchange chamber and are connected to the second chamber area and thus to the interior of the hollow fibers, in particular wherein the axially open ends open into the media spaces / gas spaces through the outer sealing area. A second flow path is formed between the connections (inlet / outlet) of the media spaces / gas spaces, which leads through the second chamber area.

[0024] The first chamber area borders the wall of the hollow fibers from the outside, and the second chamber area borders the wall of the hollow fibers from the inside.

[0025] To form the outer sealing area according to the invention, which corresponds to a conventional sealing known in the prior art, it is known to use a suitable sealant. In the invention, such a sealant is preferably formed by silicone, e.g., Wacker Elastosil, or by a polyurethane (PU).

[0026] In such mass transfer devices, especially in the design as an oxygenator, it proves to be a disadvantage that, under normal circumstances, the exchange surface and volume for the media in the device are constant and cannot be adapted to changing conditions in the application.

[0027] Changing the application conditions would necessitate replacing a previously used mass transfer device with one that has a different volume or exchange surface area. However, this is not possible in all applications.

[0028] For example, in the case of extracorporeal oxygenation of premature infants, the problem is that the development of the premature infant is accompanied by a rapid increase in blood volume, but an oxygenating exchange device cannot simply be replaced with a larger one, especially so as not to endanger the supply of oxygen to the premature infant.

[0029] Furthermore, it is difficult to wean individuals receiving oxygenator support using conventional oxygenation devices.

[0030] Publication WO 2024 / 002715 A1 by the same applicant discloses a substance exchange device in which partial volumes of the exchange chamber can be connected or separated during operation. This is achieved by a relative mechanical movement between sub-chambers movably arranged within the device, each containing its own hollow fiber package. Such movements necessitate a complex design and pose problems with regard to sealing, which must be achieved between the sub-chambers by means of separate sealing elements. This can also result in dead spaces, which are problematic in blood applications.

[0031] Against this background, an object of the invention is to provide mass exchange devices of the type mentioned above, in particular oxygenators, which make it possible to change the volume of at least one of the media participating in the exchange, in particular blood, and / or the exchange surface during operation without changing the entire device, i.e., without removing the device from the application and replacing it with another. In particular, it should be possible to increase and / or decrease the volumes of the media in the device and / or the exchange surface. This should be achieved with a sealing function that is as simple as possible to implement.

[0032] According to the invention, the problem is solved in the design of the device by dividing the first chamber area of ​​the exchange chamber into at least two sub-chambers, in particular those which are arranged in the exchange chamber in a fixed / immovable position relative to each other, each comprising a partial volume of the first chamber area, wherein at least one inner sealing area is formed between two adjacent sub-chambers of the first chamber area in the arrangement of the hollow fibers, consisting of a sealing medium that contacts the walls of the hollow fibers on the outside, wherein at least one pair of two switching means movable in the first chamber area is arranged in the first chamber area, which are spaced apart in the flow direction of the first exchange medium and between which the arrangement of hollow fibers lies, wherein each switching means can be brought into or out of contact with at least one inner sealing area by movement.wherein, in the case of existing contact between both switching elements of a pair with the same inner sealing area, the sub-chambers located on both sides of the inner sealing area are separated from each other, and in the case of no existing contact between both switching elements of a pair with the same inner sealing area, the sub-chambers located on both sides of the inner sealing area are fluidically connected in parallel.

[0033] Unlike the aforementioned prior art, the invention provides for the formation of sub-chambers that are fixedly arranged relative to one another within the device, particularly in the first chamber region. These fixed sub-chambers are separated from one another by a respective internal sealing area. Several, and in particular at least two, such sub-chambers lie fluidically parallel to one another in the flow path of the first medium or in the first chamber region, and according to the invention, it is possible to selectively open and close at least one sub-chamber on either side of the hollow fiber bundle using the switching means.

[0034] The at least one inner sealing area is preferably designed separately from the at least one outer sealing area, i.e., it does not have a one-piece connection to it made of sealant. The sealant of the outer sealing area is preferably the same as that of the at least one inner sealing area. The sealants can also be different, e.g., polyurethane for the outer sealing area and silicone for the at least one inner sealing area.

[0035] The at least one inner sealing area seals only between the sub-areas of the first chamber area. Each inner sealing area is located in the first chamber area, preferably inside the at least one outer sealing area.

[0036] Essential to the invention is that in each sealing area, whether external or internal, the walls of at least some of the hollow fibers of the preferably single arrangement of hollow fibers are contacted from the outside by the sealing agent that forms the sealing area. In a respective sub-chamber, the hollow fibers are free of sealing agent, in particular so that they can be contacted externally by the medium. The fluidic parallel alignment of the sub-chambers preferably results from the fact that at least one internal sealing area, and preferably also at least one external sealing area, extends through the entire arrangement of hollow fibers in a direction corresponding to the flow direction of the first medium and the spacing of the two switching elements of a pair. This results in the sub-chambers lying side by side transversely to the flow direction, and in particular perpendicularly to the flow direction.

[0037] The invention can provide that one of several formed sub-chambers in the device cannot be shut off, i.e., is always flowing through, and that at least one sub-chamber can be selectively shut off or connected in parallel to another sub-chamber, in particular to the one that cannot be shut off.

[0038] Preferably, it is provided that a respective inner sealing area, and in particular also a respective outer sealing area, extends beyond the arrangement of the hollow fibers, especially in the direction of the flow between the connections or the spacing of the switching means of a pair.

[0039] This creates sealing projections, particularly partially annular or ring-shaped ones, that extend beyond the hollow fibers on both sides of the arrangement, where a sealing surface of the respective switching element can come into contact with the sealing system. Such sealing projections can have a convex cross-section perpendicular to the ring's extent, for example, or a circular surface.

[0040] Furthermore, it is preferably provided that by moving a respective switching means of at least one pair in a first direction of movement, in particular away from the arrangement of the plurality of hollow fibers and / or from the at least one inner sealing area, adjacent sub-chambers arranged around the inner sealing area can be connected, and by moving a respective switching means of at least one pair in a second, in particular opposite, direction of movement, in particular towards the arrangement of the plurality of hollow fibers and / or towards the at least one inner sealing area, adjacent sub-chambers arranged around the inner sealing area can be separated from each other.

[0041] It is preferably provided that the arrangement of the plurality of hollow fibers is formed by a package of hollow fibers stacked in a stacking direction, in particular by a package of hollow fiber mats stacked in a stacking direction and lying flat in every position, wherein the stacking direction corresponds to the direction of the spacing of the two switching means of the at least one pair, preferably wherein the hollow fibers in the package extend transversely, in particular perpendicularly to the stacking direction.

[0042] A further development provides that the at least one inner sealing area, in particular each inner sealing area, preferably also the single outer sealing area, is formed by a ring consisting of the sealing agent, which extends closed over a full 360 degrees around a package axis that extends through the package in the direction of the spacing of the switching means of the at least one pair, in particular centrally, wherein an annular gap is arranged between the at least one outer sealing area, in particular between the single outer sealing area and the inner sealing area located radially inside it, in particular also between adjacent inner sealing areas, in which the hollow fibers of the package are free of sealing agent, in particular wherein each annular gap forms a partial chamber of the first chamber area.The aforementioned package axis preferably penetrates the free interior area centrally, and preferably corresponds to the rotation axis mentioned later. Each annular gap is preferably arranged concentrically / coaxially to this axis.

[0043] In such an arrangement of hollow fibers, or such a package, preferably directly adjacent to the package axis and surrounding it by a full 360 degrees, an inner area free of sealant is formed in the package, which forms a partial chamber of the first chamber area in which the hollow fibers are free of sealant, in particular wherein the inner area is surrounded coaxially to the package axis by at least one inner sealing area.

[0044] The cross-section of the free interior area, viewed in section perpendicular to the package axis, is preferably circular at every axial position. The cross-section need not be uniform in the axial direction; in particular, it may decrease in one axial direction with a parabolic dependence on the axial position and increase in the opposite direction with the same parabolic dependence. Such a parabolic dependence arises when the sealing areas are manufactured using a centrifuge and the acceleration generated by the centrifuge is superimposed on the acceleration due to gravity.

[0045] Preferably, the free inner area forms a first sub-chamber of the first chamber area, in particular the flow through which with the first exchange medium within the device cannot be blocked by the switching means, to which at least one further sub-chamber can be fluidically switched in parallel by movement of both switching means of the at least one pair, which is formed by an annular gap that lies radially outside the inner sealing area that surrounds the first sub-chamber (free inner area).

[0046] The inner area and the at least one annular gap are thus separated from each other in a radial direction with respect to the package axis by at least one annular inner sealing area.

[0047] The movement of the switching means is preferably an axial movement of both switching means in opposite directions with respect to the package axis.

[0048] It is further preferably provided that the at least one outer sealing area, in particular the only outer sealing area, has at least in some areas an excess on its circumference extending around the package axis compared to the inner cross-section of the exchange chamber (in particular at least at the location of the outer sealing area) in which the package with the outer sealing area is located, in particular such that the outer sealing area is radially compressed in the exchange chamber in the areas having the excess with respect to the package axis.

[0049] This allows the package to be manufactured and filled with sealant to form the sealing areas externally from the subsequent housing of the device, so that after manufacturing, the package can be inserted into the exchange chamber under compression, and the compression creates a seal on the inner walls of the exchange chamber, thus achieving a tight seal between the two chamber areas. Preferably, a manufacturing housing used for producing the package has a larger free internal cross-section (viewed in section perpendicular to the package axis / axis of rotation), at least in the area accommodating the hollow fibers, than the housing of the device to be manufactured.

[0050] It is further preferred that in the areas having the radial excess, the sealant of the at least one outer sealing area, in particular of the only outer sealing area, covers the hollow fibers of the package with a layer in which there are no hollow fiber components.

[0051] This ensures that the radial compressibility of the outer sealing area is not impaired by fiber content.

[0052] Preferably, at least two areas, in particular two opposing areas of the outer sealing region, are formed without excess material, possibly even with an undersize, in which the hollow fibers with an open inner cross-section at the end penetrate the sealant. In these areas, the interior of the hollow fibers is fluidically connected to the second chamber area in which the second exchange medium flows.

[0053] An area without excess / with undersize can be created, for example, by subsequently removing / cutting off an excess area, thereby opening and freeing the previously sealed axial ends of the hollow fibers. Such an area without excess / with undersize, containing exposed hollow fibers, is preferably located in the aforementioned media space / gas space.

[0054] The invention further preferably provides that the switching means of the at least one pair are slidably mounted in the direction of their spacing in the first chamber area along a common axis, in particular in the direction of the package axis of a aforementioned arrangement and / or axially slidably mounted in the flow direction of the first medium.

[0055] Preferably, each switching element forms a piston axially displaceable on the wall of the first chamber region or on another switching element, the axial end face of which, facing the arrangement of the hollow fibers, forms at least a portion of a sealing surface that interacts with an internal sealing region. In particular, the exchange chamber then forms a cylinder encompassing the hollow fiber package, in which a respective piston-like switching element is movable.

[0056] If one piston is displaceable within another piston, particularly coaxially to the aforementioned stack axis, the pistons act on different radially spaced internal sealing areas. Several piston-shaped switching elements of several pairs of switching elements located on the same side of the hollow fiber stack can form a respective radial nested arrangement, particularly in which at least one ring- or cup-shaped piston surrounds a centrally located piston.

[0057] The connections of the first chamber area for the supply and discharge of the first exchange medium are preferably formed on two movable switching elements of a pair, particularly in the case of several pairs, on the switching elements of the radially innermost pair. The aforementioned problem is solved in the method by supplementing the aforementioned process steps according to the invention by filling the manufacturing housing with a barrier fluid that has a higher specific density than the sealing medium for forming an inner sealing area, in particular which is immiscible with it, preferably during rotation at a radial position inside the outer sealing area, in particular wherein an amount of barrier fluid is selected which, upon rotation of the manufacturing housing, leads to the formation of a partial ring of barrier fluid adjacent to the outer sealing area and surrounding the axis of rotation, in particular a ring surrounding the package axis.which occupies a desired volume in the package that is to be kept free of sealant, and by filling the manufacturing housing with a predetermined quantity of liquid, hardenable sealant, in particular the same sealant used to form the outer sealing area, during rotation, radially inside the formed partial ring / ring of the barrier fluid, wherein the sealant forms a partially annular, preferably ring-shaped inner sealing area surrounding the axis of rotation, in particular the package axis, at a distance, which floats on the partial ring, in particular ring, of the barrier fluid, and by continuing the rotation until a hardening state in which the sealant of the inner sealing area is self-stable, which is achieved, for example, after exceeding the so-called pot life of the sealant, and by opening the manufacturing housing after the rotation has ended, and by removing the barrier fluid, in particular before,after or by removing the package from the manufacturing housing, whereby a gap free of barrier fluid, in particular annular gap, is formed, especially in which the hollow fibers of the package are free of sealant.

[0058] The essential concept of the invention is that the barrier fluid acts as a removable placeholder, keeping a portion of the chamber to be formed free of sealant. This is achieved by the sealant floating on the barrier fluid during rotation in the centrifuge and hardening in this state after being poured in.

[0059] If at least one further internal sealing area is to be created, the aforementioned steps of filling with a barrier fluid and subsequently filling with a sealant are repeated, whereby the barrier fluid then forms a division / ring radially inside the previously created internal sealing area.

[0060] The barrier fluid has a higher density, preferably twice as high, as the sealant used. Preferably, the barrier fluid is a perfluorocarbon.

[0061] To simplify filling, the invention preferably provides that the manufacturing housing is filled with sealant and / or barrier fluid through an inlet cover that closes the manufacturing housing and has at least one inlet channel, preferably two, opening into the inner volume of the manufacturing housing at different radial positions relative to the axis of rotation, in particular the package axis. If at least two inlet channels are provided, it is preferably provided that they are coaxial with each other.

[0062] Preferably, each of the at least two inflow channels opens into the volume of the manufacturing housing with at least two, preferably at least three spaced-apart, in particular circumferentially spaced at the same angles around the package axis, outlet openings.

[0063] It can also be preferably provided that, with only one inlet channel, this channel splits into at least two groups of channel arms, with the channel arms of different groups opening into the manufacturing housing at different radial positions. In this way, the same inlet channel can be used to fill the housing with sealant for the outer sealing area, with barrier fluid, and also with the sealant for the at least one inner sealing area. A number of groups corresponding to the number of sealing areas to be produced is sufficient. The groups preferably always open into the manufacturing housing at the radial positions where the sealing areas are to be formed. The radial inlet position of the barrier fluid, however, is not problematic.

[0064] When filling during rotation, the fluid being used (sealant or barrier fluid) will, due to centrifugal force, distribute itself into the group of channel arms of the same inlet channel that is radially outermost and not yet filled. Since fluid already filled cannot be displaced by subsequent fluid under rotation, the fluid currently being filled always flows into the group of unfilled channel arms.

[0065] This means that sealant already applied to the outer sealing area is not displaced by subsequent barrier fluid because the sealant has already hardened. The barrier fluid therefore always flows radially inside the channel arms through which sealant has previously flowed. Furthermore, the subsequent sealant does not displace the previously applied barrier fluid because the latter has a higher density and thus floats on top of the barrier fluid.

[0066] The base and lid of the manufacturing housing can have partially annular or preferably ring-shaped grooves arranged at the radial positions where the sealing areas are to be formed. Two grooves are positioned opposite each other, with the space between them containing the hollow fibers of the assembly during manufacturing. Filling these grooves with the sealant creates the sealing projections, which connect integrally to the axial sealing areas.

[0067] Should any hardened sealant protrude into the opening of the respective channel after manufacturing, it can be removed after the package has been removed, e.g., by cutting it off. It is particularly advantageous if a channel opening in the cover is arranged radially laterally offset from the point of maximum protrusion of the sealing projection or completely radially adjacent to the sealing projection or the groove forming it. In this case, it is not necessary to cut in an area used for sealing by means of a switching device.

[0068] After the package is removed from the manufacturing housing, the barrier fluid initially flows out of the at least one annular space produced. Preferably, the removal of the barrier fluid can be accelerated by heating the package, particularly above ambient temperature, which leads to an increase in the vapor pressure of the barrier fluid, causing it to evaporate more quickly.

[0069] Preferably, the barrier fluid is completely removed, in particular by heating, before the package is inserted into a device housing under compression.

[0070] The method preferably provides that the gaseous barrier fluid produced during heating is collected and recovered by cooling, in particular below ambient temperature, and the associated condensation, e.g. in a cold trap.

[0071] The invention is described in more detail with reference to the following figures.

[0072] Figures 1 and 2 show a first embodiment of a mass transfer device according to the invention, with Figure 1 showing a section and Figure 2 showing a sectioned perspective view. Figures 1 and 2 also differ in that only Figure 1 shows the arrangement 3 of hollow fibers 3a located in the housing 1.

[0073] For clarity, this arrangement 3 is not shown in Figure 2, but it is present in a device according to the invention, just as in Figure 1. With regard to the technical features, the representations in Figures 1 and 2 are therefore identical.

[0074] The arrangement 3 of hollow fibers 3a is shown in Figure 3 in a side sectional view and a top view, isolated from the other components. Figure 4 further shows only the central housing part 1a of the housing 1 in two side views, partially cut away, and in a top view, without showing the arrangement 3 of hollow fibers 3 contained therein.

[0075] The device has a housing 1, which in the illustrated embodiment is multi-part. It comprises a central housing part 1a, in which the arrangement 3 of hollow fibers 3a is located, and two adjoining housing parts 1b on either side, which can also be referred to as covers, in which a switching element 7a or 7b of a single pair 7 of switching elements 7a, 7b is slidably received. The central housing part 1a and the housing parts 1b are tightly connected to one another, e.g., by screwing or welding, in particular with sealing elements inserted between them.

[0076] In the housing 1, in particular in the middle housing part 1a, an exchange chamber 2 is formed in which the arrangement 3 of hollow fibers 3a is located.

[0077] In this embodiment, and particularly with reference to Figure 3, the arrangement 3 of hollow fibers 3a forms a package of hollow fibers 3a stacked in the stacking direction 3c, e.g., stacked hollow fiber mats, in particular in which the hollow fibers 3a are connected by warp threads. Within one of the stacked layers of hollow fibers 3a, several hollow fibers 3a lie parallel to one another, preferably also in the same plane with a direction of extension in which the axial ends 3b of the hollow fibers 3a are spaced apart.

[0078] Different layers of hollow fibers 3a can have the same or different orientations. For example, successive layers can be arranged alternately with an angle other than zero degrees between the orientations of adjacent layers. This angle is preferably 90 degrees.

[0079] The axial ends 3b of the hollow fibers 3a are connected to each other and also to the

[0080] The inner wall of the housing 1, in particular the inner wall of the housing part 1a, is sealed and connected with a sealant, which forms an outer sealing area 4, which here is designed in an annular shape.

[0081] Such an outer sealing area 4 can be produced by potting with a sealant using a centrifuge, preferably wherein the axis of rotation is centered in the arrangement 3 and parallel to the stacking direction 3c. This potting process is known to those skilled in the art.

[0082] The outer sealing area 4 has at least two opposing areas 4a in which the hollow fibers 3 are cut free, so that their axial ends extend openly through the outer sealing area 4. Depending on the extent (in particular in the circumferential direction around the stacking direction 3c) of these cut-free areas 4a, the number of usable hollow fibers 3a of the arrangement 3 is defined.

[0083] Due to the sealing by the outer sealing area 4 at the hollow fiber ends 3b between each other and to the housing wall, the exchange chamber 2 is divided into two chamber areas, a first chamber area 2a and a second chamber area 2b.

[0084] The first chamber area 2a represents the area of ​​the exchange chamber 2 in which the first medium can flow, the first medium contacting the hollow fibers 3a on the outside. This first chamber area 2a opens into the two opposing connections 5a, which are guided as a channel through the switching means 7a and 7b, preferably with the end of the respective channel widening towards the hollow fiber arrangement 3.

[0085] The second chamber area 2b represents the area of ​​the exchange chamber 2 in which the second medium can flow, whereby the second medium contacts the hollow fibers 3a on the inside, i.e., flows through the hollow fibers 3a. This second chamber area 2b opens through the open ends of the hollow fibers 3a and through the cut-out areas 4a into the opposing connections 5b, which are guided through the wall of the central housing part 1a.

[0086] Figure 4 shows that the central housing part 1a has at least one connection 5b on one side, which can be used, for example, for gas to flow into the second chamber area 2b, and preferably has several connections 5b on an opposite side, which allow, for example, gas to flow freely out of the second chamber area 2b to the environment. Alternatively, only one venting connection 5b may be provided.

[0087] According to the invention, the first chamber area 2a of the exchange chamber 2 is further provided that it is subdivided into at least two sub-chambers, in this embodiment being subdivided into exactly two sub-chambers 2a1 and 2a2. Both sub-chambers 2a1 and 2a2 are arranged in the exchange chamber 2, or rather in its first chamber area 2a, in a fixed / immovable position relative to each other and are formed in the same arrangement 3 of hollow fibers 3a. Each sub-chamber 2a1, 2a2 comprises a respective partial volume of the first chamber area 2a. Between the two adjacent sub-chambers 2a1 and 2a2 of the first chamber area 2a in the arrangement 3 of hollow fibers 3, at least one internal sealing area 6, here exactly one single internal sealing area 6, is formed from a sealant that contacts the walls of the hollow fibers 3a externally. The sub-chambers 2a1 and 2a2 are thus separated from each other by the inner sealing area 6 and lie fluidically parallel next to each other with respect tothe flow direction of the first medium between the connections 5a. The second subchamber 2a2 is ring-shaped and coaxially surrounds the cylindrical first subchamber 2a1.

[0088] Figure 3 further shows in the upper view that the inner sealing area 6, and also the outer sealing area 4, project in the flow direction of the first medium between the connections 5a and in the direction 3c of the stacking, respectively, over the arrangement 3 of hollow fibers 3a, and that the respective projection forms a preferably annular sealing protrusion. This protrusion can have any shape, here, for example, it is planar. In Figures 6E and 6F, the protrusion is viewed convexly in section perpendicular to the ring's extent.

[0089] The sealing projection on the outer sealing area 4 is contacted by an axially end-face surface of the cover-forming housing parts 1 b and the sealing projection on the inner sealing area 6 by sealing surfaces on the switching means 7a or 7b, which are located radially outside the widening of the channel in the respective switching means 7a, 7b.

[0090] Figure 1 shows, with the position of the switching means 7a and 7b, which are designed as axially displaceable pistons along the flow direction of the first medium in the respective cover part 1b, that the first medium can only flow through the partial chamber 2a1, which cannot be closed by the switching means 7a, 7b.

[0091] Since the sealing surfaces of both opposing switching elements 7a, 7b of the pair 7, which face the arrangement 3 of the hollow fibers 3a, are in close contact with the sealing projection of the inner sealing area 6, the second subchamber 2a2, located radially outside the first subchamber 2a1, is excluded from the flow path and can be added to the flow path by pulling both switching elements 7a and 7b away from the arrangement 3 of the hollow fibers 3a. The first medium can then flow over the inner sealing area 6 into the second subchamber 2a2 and through it. The mass transfer area of ​​the entire arrangement 3 is clearly larger when the second subchamber 2a2 is also flowed through. By reversing the movement of both switching elements 7a, 7b towards the arrangement 3, the second subchamber 2a2 can be removed from the flow path again.

[0092] To achieve the tight movability of the switching elements 7a, 7b, these are designed as pistons which are preferably slidably mounted on the inner wall of the housing parts 1b forming the covers, sealed by seals. Figure 1 further shows that the channel in the switching element 7a, 7b widens to a diameter that corresponds at least substantially to the inner diameter of the inner sealing area 6 with which the switching element 7a, 7b interacts.

[0093] For manual movement of the switching elements 7a, 7b, these are connected to handles 9 which extend through the housing parts 1b. The handles 9 may have a central recess for better accessibility of the terminals 5a in the switching elements 7a, 7b.

[0094] By implementing the figures 1 to 5, the exchange surface of the device can thus be switched between two sizes.

[0095] In contrast, Figure 5 shows an embodiment in which the exchange surface can be switched between three sizes. For this purpose, the arrangement 3 of hollow fibers 3a radially inside the outer sealing area 4 has not just one, but two coaxially annular inner sealing areas 6a, 6b.

[0096] The central inner area, or central sub-chamber 2a1, is thereby surrounded by two sub-chambers 2a2 and 2a3. With otherwise identical construction and function, this device has two pairs of switching elements 7a, b and 10a, 10b. The switching elements 10a, 10b are designed as pistons slidably arranged on the inner wall of the cover-forming housing parts 1b, and the switching elements 7a, 7b are designed as pistons slidably within the switching elements 10a, 10b. The sealing surfaces of the radially inner switching elements 7a, 7b interact with the radially inner sealing area 6a, and the sealing surfaces of the radially outer switching elements 10a, 10b interact with the radially outer sealing area 6b. Here, too, the respective switching elements have handles 9, preferably with central recesses.

[0097] The sequence of figures 6 visualizes the process in several steps.

[0098] Production of an arrangement 3 of hollow fibers 3a with an outer sealing area 4 and an inner sealing area 6 for use in a device according to the invention previously described.

[0099] First, as shown in Figure 6A, a manufacturing housing 11 is filled with a package of stacked hollow fibers 3a and closed with an inlet cover 12. The inlet cover 12 is two-part in the embodiment shown here, but this is not essential for the invention.

[0100] The inlet cover 12 has inlet channels 13, 13b that open into the interior of the manufacturing housing 11 at at least two different radial positions. In a filling area, the outer inlet channel 13b coaxially surrounds the inner inlet channel 13a. In the outlet area, both inlet channels 13a, 13b are split into several individual channel arms that open into the volume of the manufacturing housing 11 at several circumferential positions and at the same radial position with respect to the axis of rotation 14. The channel arms of the inner inlet channel 13a are shown with solid lines in this section. The channel arms of the outer inlet channel 13b are obscured in this section and shown with dashed lines.

[0101] The base of the manufacturing housing 11 and the inlet cover 12 have grooves 15 in opposing surfaces surrounding the hollow fiber package, which, after being filled with sealant, form the aforementioned sealing projections. The grooves 15 are arranged as annular grooves at the radial positions where the sealing areas with the sealing projections are to be formed.

[0102] According to Figure 6B, for example, in a centrifuge (not shown here), the filled production housing 11, closed with the inlet cover 12, is filled with a sealant from a reservoir via at least one radially outermost inlet channel 13b in the inlet cover 12, as indicated by the arrow. This is done while the housing is rotating about the axis of rotation 14, which is parallel to the stacking axis. The centrifugal force accelerates the sealant radially outwards, where it hardens while the rotation is maintained. This forms the outer sealing area 4. Subsequently, according to Figure 6C, a barrier fluid 16 is introduced into the production housing 11 through the inlet channel 13a, which opens radially inwards from the aforementioned inlet channel 13b.When rotating, this forms a ring that radially borders the outer sealing area 4 on the inside and occupies an annular space which should be kept free of this sealant during subsequent filling with another sealant.

[0103] Figure 6D shows the subsequent filling with sealant. The sealant added here forms a ring that floats on the ring of barrier fluid 16 because the barrier fluid 16 has a higher density than the sealant. Rotation is maintained until the sealant, which here forms an inner sealing area 4, has also hardened, or at least hardened to the point where it is inherently stable and remains in the shape it acquired during rotation after the rotation is stopped. In this way, the inner sealing area 6 is formed.

[0104] One or more additional internal sealing areas 6 can be formed by repeating the steps of filling with barrier fluid 16 and further sealant radially inside the previously produced internal sealing area 6 shown in Figure 6D, which may require additional radially inside openings of the at least one inflow channel in the lid.

[0105] After all internal sealing areas have been produced, the arrangement 3 of hollow fibers 3a according to Figure 6E, with all sealing areas 4, 6 cured on / in it, is removed from the manufacturing housing 11, whereby the barrier fluid 16 flows out of the arrangement 3. The removal of the barrier fluid 16 can be accelerated by the application of heat.

[0106] Figure 6F shows that in a chamber the temperature T1 is higher than the ambient temperature T uThe temperature can be increased to achieve the evaporation of the barrier fluid 16. The gaseous barrier fluid 16 can be pumped out and cooled in a separate chamber to a temperature T2 below the ambient temperature, so that the barrier fluid 16 condenses in this cooled chamber and can thus be recovered. Preferably, the pressure in the heated chamber is lower than in the cooled chamber.

[0107] If sealing projections extending axially in the direction of the package axis / the stacking direction / the direction of rotation are to be produced on the outer sealing area 4 or on the at least one inner sealing area 6 beyond the arrangement 3 of hollow fibers 3a, the invention provides, as shown, that correspondingly positioned annular grooves 15 are present in the base of the manufacturing housing and in the inner surface of the inlet cover 12, into which the respective sealing compound can enter. Alternatively, it can be provided that the sealing surfaces of the switching elements have an axial local protrusion. For example, in such a case, the grooves 15 can also be omitted.

[0108] The arrangement 3 of hollow fibers 3a produced in this way can be inserted into a housing 1 to form a device for mass transfer, as shown in the figures.

Claims

Patent claims 1. Device for the exchange of substances between a first exchange medium, in particular blood, and at least a second exchange medium, in particular a gas, comprising a housing (1) with at least one exchange chamber (2) into which an arrangement (3), in particular a single arrangement (3) of a plurality of material-permeable hollow fibers (3a), is inserted, wherein in the arrangement (3) of the hollow fibers (3a) the outer walls of the hollow fibers (3a) are sealed at least at the end regions (3b) of the hollow fibers (3a) spaced apart in the fiber extension direction from each other and at least partially against a wall region of the exchange chamber (2) by means of at least one outer sealing region (4) made of a sealing agent, wherein the exchange chamber (2) is divided by the walls of the hollow fibers (3a) and by the at least one outer sealing region (4) into a first and a second chamber region (2a, 2b),wherein the hollow fibers (3a) in the first chamber region (2a) of the at least one exchange chamber (2) are open to flow of the first exchange medium in a flow direction (8) between at least two connections (5a) of the first chamber region (2a) and the hollow fibers (3a) in the second chamber region (2b) of the at least one exchange chamber (2) are open to flow of the at least one second exchange medium in a flow direction (8) between at least two connections (5b) of the second chamber region (2), characterized in that the first chamber region (2a) of the exchange chamber (2) is subdivided into at least two sub-chambers (2a1 , 2a2 , 2a3), in particular, which are arranged in the exchange chamber (2) in a fixed / immovable position relative to each other, each comprising a partial volume of the first chamber region (2a), wherein at least one inner sealing region (6) is formed between two adjacent partial chambers (2a1, 2a2, 2a3) of the first chamber region (2a) in the arrangement (3) of the hollow fibers (3a) from a sealing agent that contacts the walls of the hollow fibers (3a) externally, wherein at least one pair of two switching means (7a, 7b, 10a, 10b) movable in the first chamber region (2a) is arranged, which are spaced apart in the flow direction (8) of the first exchange medium and between which the arrangement (3) of hollow fibers (3a) lies, wherein each switching means (7a, 7b, 10a, 10b) can be brought into or out of contact with at least one inner sealing region (6) by movement, wherein at an existing contact between both switching devices (7a, 7b, 10a,10b) of a pair with the same inner sealing area (6) the sub-chambers (2a1 , 2a2, 2a3) located on both sides of the inner sealing area (6) are separated from each other and, in the absence of contact between the two switching means (7a, 7b, 10a, 10b) of a pair with the same inner sealing area (6), the sub-chambers (2a1 , 2a2, 2a3) located on both sides of the inner sealing area (6) are fluidically connected in parallel.

2. Device according to claim 1, characterized in that at least one inner sealing area (6), preferably also one outer sealing area (4), extends through the entire arrangement (3) of the hollow fibers (3a) in a direction of the spacing of the two switching means (7a, 7b, 10a, 10b) of a pair, in particular protrudes beyond the arrangement of the hollow fibers (3a).

3. Device according to one of the preceding claims, characterized in that by a movement of a respective switching means (7a, 7b, 10a, 10b) at least one pair in a first direction of movement, in particular of the arrangement (3) of the plurality of Hollow fibers (3a) and / or partial chambers (2a1, 2a2, 2a3) arranged adjacent to the inner sealing area (6) away from the at least one inner sealing area (6), and can be connected by a movement of a respective switching means (7a, 7b, 10a, 10b) of at least one pair in a second, in particular opposite, direction of movement, in particular towards the arrangement (3) of the plurality of hollow fibers (3a) and / or towards the at least one inner sealing area (6), partial chambers (2a1, 2a2, 2a3) arranged adjacent to the inner sealing area (6).

4. Device according to one of the preceding claims, characterized in that the arrangement (3) of the plurality of hollow fibers (3a) is formed by a package of hollow fibers (3a) stacked in a stacking direction (3c), in particular by a package of hollow fiber mats stacked in a stacking direction (3c) and lying flat in every position, wherein the stacking direction (3c) corresponds to the direction of the spacing of the two switching means (7a, 7b, 10a, 10b) of the at least one pair, preferably wherein the hollow fibers (3a) extend transversely, in particular perpendicularly to the stacking direction (3c) in the package.

5. Device according to claim 4, characterized in that the at least one inner sealing area (6), in particular each inner sealing area (6), preferably also the single outer sealing area (4), is formed by a ring consisting of the sealing means, which extends closed over a full 360 degrees around a package axis, which extends through the package in the direction of the spacing of the switching means (7a, 7b, 10a, 10b) of the at least one pair or parallel to the stacking direction (3c), preferably centrally, wherein an annular gap is arranged between the at least one outer sealing area (4), in particular between the single outer sealing area (4) and the inner sealing area located radially inside it, in particular also between adjacent inner sealing areas (4), in which the Hollow fibers (3) of the package are free of sealant, in particular wherein each annular gap forms a sub-chamber (2a2, 2a3) of the first chamber region (2a).

6. Device according to claim 4 or 5, characterized in that directly adjacent to the package axis and surrounding it by a full 360 degrees, an inner area free of sealant is formed in the package of stacked hollow fibers (3a), which forms a partial chamber (2a1 ) of the first chamber area (2a) in which the hollow fibers (3a) are free of sealant, in particular wherein the inner area is surrounded coaxially to the package axis by at least one inner sealing area (6).

7. Device according to claim 6, characterized in that the free inner area forms a first partial chamber (2a1 ) of the first chamber area (2a), in particular the flow through which with the first exchange medium within the device cannot be blocked by the switching means (7a, 7b, 10a, 10b), to which at least one further partial chamber (2a2, 2a3) can be fluidically switched in parallel by movement of both switching means (7a, 7b, 10a, 10b) of the at least one pair, which is formed by an annular gap located radially outside the inner area.

8. Device according to one of the preceding claims 4 to 7, characterized in that the at least one outer sealing area (4), in particular the only outer sealing area (4), has at least in certain areas an excess on its circumference extending around the package axis compared to the inner cross-section of the exchange chamber (2) in which the package with the outer sealing area (4) is located, in particular such that the outer sealing area (4) is radially compressed in the exchange chamber (2) in the areas having the excess with respect to the package axis.

9. Device according to claim 8, characterized in that in the areas having the radial excess the sealing agent of at least in an outer sealing area (4), in particular the only outer sealing area (4) the hollow fibers (3a) of the package are covered with a layer in which there are no hollow fiber components, preferably wherein at least two areas (4a), in particular two opposing areas (4a) of the outer sealing area (4) are formed without excess, in which the hollow fibers with an end-open inner cross-section penetrate the sealant.

10. Device according to one of the preceding claims, characterized in that the switching means (7a, 7b, 10a, 10b) of the at least one pair are slidably mounted in the direction of their spacing in the first chamber region (2a) along a common axis, in particular being axially slidably mounted in the direction of the package axis of an arrangement (3) according to claim 4, in particular wherein each switching means (7a, 7b, 10a, 10b) forms a piston axially displaceable on the wall of the first chamber region (2a) or on another switching means (10a, 10b), the axial end face of which facing the arrangement (3) of the hollow fibers (3a) forms at least partially a sealing surface cooperating with an inner sealing region (6).

11. Device according to claim 10, characterized in that the connections (5a) of the first chamber area (2a) are formed on two movable switching means (7a, 7b) of a pair, in particular in the case of several pairs on the switching means (7a, 7b) of the radially innermost pair.

12. Method for producing a hollow fiber package, in particular for a device according to one of the preceding claims, comprising the following steps: a. in a production housing (11 ) a package of hollow fibers (3a) is produced by stacking in a stacking direction (3c) of a plurality of hollow fibers (3a), in particular which are connected to at least one mat - preferably in each stacking layer, wherein the hollow fibers (3a) extend transversely, in particular perpendicularly to the stacking direction (3c), and b. rotating the manufacturing housing (11) with the package of hollow fibers (3a) arranged therein about an axis of rotation (14) which is parallel to the stacking direction (3c), in particular about a package axis which penetrates the package in the stacking direction (3c), in particular centrally, preferably in a centrifuge, c.Filling the manufacturing housing (11) with a predetermined quantity of liquid, hardenable sealant at a radial distance, in particular a maximum radial distance from the axis of rotation (14), in particular from the package axis, during rotation, whereby an at least partially annular outer sealing area (4) surrounding the axis of rotation (14), in particular the package axis, is formed, preferably an annular outer sealing area (4) of liquid sealant closed over 360 degrees, in which the sealant contacts the outer wall of the hollow fibers (3a), in particular forming the radial outer circumference of the package, more preferably fixing the package radially outside by hardening the sealant, i.e. continuing the rotation until a hardening state in which the sealant of the outer sealing area (4) is self-stable, characterized by e.Filling the manufacturing housing (11 ) with a barrier fluid (16) which has a higher specific density than the sealing medium to form an internal sealing area (6), in particular which is immiscible with it, preferably during rotation. a radial position inside the outer sealing area (4), in particular wherein a quantity of barrier fluid (16) is selected which, upon rotation of the manufacturing housing (11), leads to the formation of a partial ring, in particular a ring surrounding the axis of rotation (14), adjacent to the outer sealing area (6) and surrounding the axis of rotation (14), which occupies a desired volume in the package that is to be kept free of sealant, f. filling the manufacturing housing (11) with a predetermined quantity of liquid, hardenable sealant, in particular the same sealant used to form the outer sealing area (4), during rotation, radially inside the formed partial ring / ring of barrier fluid (16), wherein the sealant forms a partial annular, preferably ring-shaped, inner sealing area (6) surrounding the axis of rotation (14), in particular the package axis, at a distance, which floats on the partial ring, in particular ring, of barrier fluid (16), g.Continuing the rotation until a hardening state is reached in which the sealant of the inner sealing area (6) is self-stabilizing, and h. opening the manufacturing housing (11) after the rotation has ended, and i. removing the barrier fluid (16), in particular before, after or by removing the package from the manufacturing housing (11), thereby forming a gap free of barrier fluid (16), in particular annular gap, in particular in which the hollow fibers (3a) of the package are free of sealant.

13. Method according to claim 12, characterized in that, after step g) to form at least one further internal sealing area (6), steps e) and f) are repeated, with the difference that the The barrier fluid (16) is filled radially inside the manufacturing housing (11) from the previously manufactured inner sealing area (6).

14. Method according to claim 12 or 13, characterized in that the filling of the manufacturing housing (11 ) with sealing agent and / or barrier fluid (16) is effected by an inlet cover (12) closing the manufacturing housing (11 ), which has at least one inlet channel (13a, 13b), preferably two inlet channels (13a, 13b), which open(s) into the inner volume of the manufacturing housing (11 ) at different radial positions to the axis of rotation (14), in particular to the package axis, in particular wherein the at least two inlet channels (13a, 13b) are at least partially coaxial to each other.

15. Method according to any one of the preceding claims 12 to 14, characterized in that the removal of the barrier fluid (16) is accelerated by heating the package.

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