A DIFFUSION AND/OR FILTRATION APPARATUS, A BLANK FOR THE MAIN PART OF THE HOUSING INTENDED FOR SAID APPARATUS AND A METHOD OF MANUFACTURING THE APPARATUS

Abstract: A diffusion and/or filtration apparatus, including a housing (2) consisting of a cylindrical open-ended main part closed by two end caps (10) and being provided with an inlet and an outlet (11) for a first fluid and at least one outlet (4) for a second fluid, said first fluid being adapted to flow through the fibers (1) of a bundle of semipermeable hollow fibers arranged between two end walls (3) within the housing (2) and said second fluid being adapted to be removed from the space outside the fibers through said at least one outlet (4) for the second fluid. The apparatus is made from a blank for the main part of the housing (2), in which said at least one outlet for the second fluid, which is arranged on the main part, is closed by a penetratable membrane. The invention relates also to a method of manufacturing a diffusion and/or filtration apparatus of the above kind.

Description: TECHNICAL FIELD The present invention relates to a method of manufacturing a diffusion and/or filtration apparatus, including a housing consisting of a cylindrical open ended main part closed by two end caps and being provided with an inlet and an outlet for a first fluid situated on said end caps and at least one outlet for a second fluid situated on said main part, said first fluid being adapted to flow through the fibers of a bundle of semipermeable hollow fibers arranged between two end walls within the housing and said second fluid being adapted to be removed from the space outside the fibers through said at least one outlet for the second fluid. The invention relates furthermore to a blank for the main part of said housing and to an apparatus provided by the method. Devices of the above kind are used for e g different kinds of medical treatment such as hemodialysis, hemofiltration, plasmapheresis and immunotherapy. Other fields of use are for instance dialysis in general and filtration in general, for example in connection with cleaning or desalination of sea water. TECHNICAL STANDPOINT In connection with the production of devices of the above kind each end of the housing with a bundle of fibers placed therein is normally enclosed in a casting mould to which the material for the adjacent end wall is fed in a liquid condition penetrating into and around the fibers. The penetration is so controlled by the casting that the penetration into the fibers is less than around the fibers, making it possible to open the openings of the fibers by making a cut between the surfaces restricting the two different penetration depths, respectively. How the end walls may be moulded is described more in detail in for instance EP-B-0 165 478, US-A-4 227 295 and US-A-4 329 229. Before the moulding of the end walls the fibers are normally flushed by a cleaning liquid as well inside as outside the fibers. This flushing is normally made in separate housing having the simple form of an open-ended tube. If it instead should be made in the final housing of the device there is a risk that a part of the cleaning liquid may be remaining in the housing, especially in inlets and outlets arranged in the housing wall. DESCRIPTION OF THE INVENTION One object of the present invention is to provide a construction of a diffusion and/or filtration apparatus in which the above discussed flushing of the fibers before the moulding of the end walls may be made in the final housing of the apparatus without the above mentioned risks. This is made in accordance with the following claims. The blank is characterized in that said at least one outlet for the second fluid, which is arranged on the main part of the housing, is closed by a penetratable membrane, providing a temporary closure which prevents the flushing liquid from entering said outlet for the second fluid. The blank is preferably also provided with an inlet for said second fluid, which also is closed by a penetratable membrane. Such an inlet is necessary, if the apparatus is intended to be used for e g dialysis. If it on the other hand is intended only to be used for filtration it will be enough, if the housing is provided with only an outlet for the filtrate beside the inlet and the outlet for a filtrated liquid. In the ready made apparatus said at least one outlet and other possible closed outlets and inlets for said second fluid are at least partly opened in that said penetratable membrane or membranes has/have been penetrated. This penetration can be made in such a way that a part of the penetrated membrane is arranged at an angle as regards the opening provided by the penetration, thereby serving as a baffle, guiding the flow of said second fluid. Said at least one outlet for the second fluid and possible other outlets and inlets for said fluid consist preferably of a nipple arranged at a wall part of the housing, which is separated from the fiber bundle by a fluid distribution channel. An advantage of this construction is that the membranes may be penetrated easily without damaging the fiber bundle. The invention relates also to a method of manufacturing a diffusion and/or filtration apparatus of the above defined kind. The method is characterized in that said at least one outlet for the second fluid, which is arranged on the main part, is closed by a temporary closure before said bundle of hollow fibers is being flushed by a special flushing fluid inside and outside the fibers arranged within said cylindrical open-ended main part of the housing, whereafter the ends of the fibers are moulded into said end walls and opened by cutting, whereupon the apparatus finally is provided with said two end caps. Said temporary closure is preferably provided by a penetratable membrane, providing the possibility of making the above described baffles, guiding the flow of said second fluid. The penetratable membrane or any other temporary closure is preferably arranged close to the inside wall of the cylindrical open-ended main part of the housing. After the opening of the ends of the hollow fibers said fibers are being flushed a second time in order to remove any possible contamination due to the cutting. SHORT DESCRIPTION OF THE DRAWINGS Fig 1 and 2 are showing one end of an apparatus according to the invention at two phases of its manufacturing. Fig 3a and 3b are showing two different modifications of the apparatus according to the present invention, the sections being taken just inside the moulded end wall. PREFERRED EMBODIMENT OF THE INVENTION Fig 1 is showing a bundle of hollow fibers 1 in a housing 2 before the moulding of the end walls 3 shown in fig 2. A nipple 4 intended to serve as the above mentioned at least one outlet is arranged at an enlarged part 7 of the housing 2. At the end of the fibers 1 the bundle is supported by a restricted part 5 of a ring 6. This ring 6 is intended to serve as an inlet and/or an outlet for a special flushing liquid intended for flushing the inside and the outside of the fibers before the casting of the end wall 3. This ring 6 can also as described more in detail in the Swedish patent application 87.03368-4, filed simultaneously with the present application, be modified to serve as a part of the mould for the end wall 3. The nipple 4 is as mentioned above arranged on an enlarged part 7 of the housing 2, providing a distribution channel 8 for any liquid taken into or out from the apparatus through the nipple 4. In the blank shown in fig 1 the inner opening of the nipple 4 is closed by a penetratable membrane 9. As shown in fig 2 said membrane may be penetrated partly in order to provide on one hand an opening 9a and on the other hand an obliquely arranged baffle 9b, shown also in fig 3a. The baffle may be formed by a heated die and due to the form of said die it can either be given the form 9b shown in fig 3a or the form 9c shown in fig 3b, providing different guiding of the fluid either entering or leaving through the nipple 4. After the casting of the end walls 3 the ends of the fibers are opened by a cut through said end walls and through the enlarged parts 7 of the housing 2. After a second flushing of the opened ends of the fibers the apparatus is finally provided with a lid 10 with an inlet and/or outlet 11 for the fluid which is intended to be sent through the fibers. PREFERED MODE OF THE METHOD ACCORDING TO THE INVENTION As mentioned above, the invention relates also to a method of manufacturing a diffusion and/or filtration apparatus of the above defined kind, i e including a housing 2 consisting of a cylindrical open ended main part closed by two end caps 10 and being provided with an inlet and an outlet 11 for a first fluid and at least one outlet 4 for a second fluid, said first fluid being adapted to flow through the fibers of a bundle of semipermeable hollow fibers arranged between two end walls within the housing and said second fluid being adapted to be removed from the space outside the fibers through said at least one outlet for the second fluid. The method is characterized in that said at least one outlet 4 for the second fluid, which is arranged on the main part, is closed by a temporary closure before said bundle of hollow fibers is being flushed by a special flushing fluid inside and outside the fibers arranged within said cylindrical open-ended main part of the housing, whereafter the ends of the fibers are moulded into said end walls and opened by cutting, whereupon the apparatus finally is provided with said two end caps 10. The temporary closure is preferably provided by a penetratable membrane 9 arranged close to the inside wall of the cylindrical open-ended main part. In order to remove any possible contamination caused by the cutting of the fibers they are preferably being flushed a second time after said cutting.

Claims: A method of manufacturing a diffusion and/or filtration apparatus, including a housing (2) consisting of a cylindrical open ended main part closed by two end caps (10) and being provided with an inlet and an outlet (11) for a first fluid situated on said end caps and at least one outlet (4) for a second fluid situated on said main part, said first fluid being adapted to flow through the fibers (1) of a bundle of semipermeable hollow fibers arranged between two end walls (3) within the housing (2) and said second fluid being adapted to be removed from the space outside the fibers (1) through said at least one outlet (4) for the second fluid, characterized in that said at least one outlet (4) for the second fluid, which is arranged on the main part of the housing (2) is closed by a temporary closure (9) at an internal location proximate the internal wall of the housing (2) until after said bundle of hollow fibers (1) has been flushed by a special flushing fluid inside and outside the fibers arranged within said cylindrical open ended main part, whereafter the ends of the fibers (1) are moulded into said end walls (3) and opened by cutting, whereupon the apparatus finally is provided with said two end caps (10). A method according to claim 1, characterized in that said temporary closure is provided by a penetratable membrane (9). A method according to any of the claims 1-2, characterized in that the inside of the fibers is being flushed a second time after the opening of the fiber ends. Apparatus obtained by the method claimed in claim 2, characterized in that said at least one outlet (4) and other possible closed outlets and inlets (4) for said second fluid are at least partly opened in that said penetratable membrane or membranes (9) has/have been penetrated. Apparatus according to claim 4, characterized in that a part of the penetrated membrane (9b,9c) is arranged at an angle as regards the opening (9a) provided by the penetration, thereby serving as a baffle, guiding the flow of said second fluid. Apparatus according to claim 4 or 5, characterized in that said at least one outlet (4) for the second fluid and possible other outlets and inlets (4) for said fluid consist of a nipple arranged at a wall part (7) of the housing (2), which is separated from the fibre bundle by a fluid distribution channel (8). A blank for the main part of the housing (2) of the apparatus according to any of the claims 4-6 intended to be used according to the method of claim 2 for providing an apparatus according to any of the claims 4-6, characterized in that said at least one outlet (4) for the second fluid, which is arranged on the main part of the housing (2) is closed by a penetratable membrane (9). A blank according to claim 7, characterized in that it is provided also with an inlet (4) for said second fluid, which also is closed by a penetratable membrane (9).

Inventors: SPRANGER, KURT
Applicants: GAMBRO DIALYSATOREN GMBH & CO. KG
Application year: 1988
Main classification: B01D61
IPC codes: B01D63, B01D65, A61M1