Method for reconditioning a piping

Abstract

The invention relates to a method for reconditioning a leaking and / or damaged area of a piping, comprising at least the following steps: a) providing a bellows structure; b) positioning the bellows structure in the interior of the piping adjacent to the leaking and / or damaged area; c) expanding the bellows structure until the bellows structure seals the piping; d) introducing a curable material into the interior of the piping in the region of the leaking and / or damaged area; e) curing the curable material; and f) at least partially cutting free the interior of the piping.

Description

[0001] Method for repairing a pipeline

[0002] Description

[0003] Summary:

[0004] Method for repairing a leaky and / or damaged area in a pipeline, comprising at least the following steps: a) Providing a bellows body b) Positioning the bellows body in the interior of the pipeline adjacent to the leaky and / or damaged area c) Expanding the bellows body until the bellows body seals the pipeline d) Introducing a curable substance into the interior of the pipeline in the region of the leaky and / or damaged area e) Curing the curable substance f) At least partially cutting free the interior of the pipeline.

[0005] The method is particularly suitable for the trenchless rehabilitation of leaky and / or damaged, inaccessible pipelines, such as defective sewer lines. However, the method is not limited to a specific type of pipeline or a specific area of ​​application. A pipeline is a hollow body through which a gaseous, liquid, or viscous fluid or a solid-liquid mixture (e.g., wastewater) can be transported along a predetermined route. Pipelines are used in private households, in the public drinking water or wastewater supply sector, and in industrial plants. This method can be used for pipelines made of various materials, such as metal, ceramic, or plastic.Various methods for repairing leaks and / or damages on the inside wall of a pipeline are already known in the prior art, in particular the pipe-in-pipe method, in which a pipe with an inside diameter smaller than that of the existing pipe is pulled or pushed into the existing pipe until it lies over the leaky and / or damaged area on the existing pipe. However, this method has the disadvantage that it regularly leads to a reduction in the inside diameter of the newly inserted pipe and that deposits can form on the edge of the inserted pipe. Furthermore, this method can only be used on straight pipelines.Finally, a seal between the two pipes is not reliably guaranteed, so that liquid or gas can escape between the nested pipes via the damaged and / or leaking point in the pipe.

[0006] Another known method is the pipe bursting method, in which a hydraulic expander is inserted into the existing pipeline. Its expansion causes the existing pipe to rupture, and a new pipe is then inserted into the space created. However, this method does not guarantee that the structures surrounding the pipe wall will not be damaged if the existing pipe wall ruptures. It is also difficult to adequately seal the areas between the remaining existing pipe and the newly inserted pipe.

[0007] WO 1995 / 027167A1 discloses a method in which a sewer rehabilitation robot has a carrying device in which a viscous sealant is applied to the area of ​​the leaking and / or damaged area. The sealant is then pressed against the inner wall of the pipeline via an expandable expansion body. After curing, the expansion body contracts and is removed from the pipeline. This method has the disadvantage that the applied sealant settles on the inner wall of the pipeline, thereby narrowing the inner diameter of the pipeline. Here, too, deposits can form, particularly in the area of ​​the applied sealant in sewer lines, and clog the pipeline.

[0008] Furthermore, prior art methods, for example from DE 10 2020 206 094 A1, involve inserting a flexible lining tube impregnated with a curable resin into the pipeline as a liner. After insertion, the lining tube is expanded so that it fits tightly against the inner wall of the pipeline and presses the lining tube impregnated with the curable resin against the inner wall of the pipeline. After the resin has cured, the lining tube can then be removed from the pipeline.

[0009] DE 10 2020 106 094 A1 describes how an inflatable rubber bellows is arranged on a rehabilitation packer that can be moved or slid within the pipe. Resin-impregnated rehabilitation mats are arranged on the outer circumference of the rubber bellows. When the rubber bellows is inflated, these mats can be pressed against the inner wall of the pipe and harden there. Furthermore, when the rehabilitation mat is pressed against the inner wall of the pipeline, the resin can penetrate cracks or open areas in the pipe. After the rehabilitation packer and rubber bellows are removed, the rehabilitation mat and the resin remain at the previously leaky and / or damaged area of ​​the pipeline. With both of the above-mentioned pipeline repair methods, the inner diameter of the existing pipeline is also reduced, as the sealing compound is deposited flatly on the inner wall of the pipeline.The sealing mat therefore causes adhesions to form in the area of ​​the repaired spot and can block the pipe.

[0010] Finally, WO2021 / 063448A1 discloses a device comprising a storage container for PU material and a discharge opening. In this method for repairing pipelines, the device is inserted into the pipeline until the discharge opening is located in the area of ​​the leaking and / or damaged part of the pipe wall. The PU material is then pressed from the storage container through the discharge opening against the inner wall of the pipeline.

[0011] In another method, WO2021 / 063448A1 proposes that a cover element be arranged on a movable support element, by means of which the PU material is pressed between the cover element and the inner wall of the pipeline. This method also inevitably leads to a narrowing of the inner diameter within the pipeline, which leads to the problems described above. In addition, damaged pipe sections, root growth, or other foreign bodies remain within the pipeline. WO1990 / 005874 A1 discloses a device for repairing a main line, which can also be used to repair a leaky, corroded section of a branch pipe that flows into the main line.

[0012] US 5,527,133 discloses a tool comprising a casing plate with an outlet opening for a filler compound, to which a pressure line for injecting a sealing compound can be connected. To reduce the time required for the repair process, a second opening is provided next to the outlet opening, which is sealed in an airtight and pressure-tight manner by an elastically deformable, balloon-like inflatable flat object. A chamber adjoins the rear of the second opening, and the chamber can be connected to a pressure source to inflate the flat object like a balloon.

[0013] EP 2 287 511 A1 discloses a method and system for permanently sealing a branch sewer line at the junction between a branch sewer line and a main sewer line by providing a flexible bag made of a substantially liquid-tight material with a hose for supplying liquids into the flexible bag. The flexible bag defines a deflated state, which defines a diameter smaller than the diameter of the branch line, and a filled state, which defines a diameter at least equal to the diameter of the branch line. The method and system further comprise a remotely controlled piping device that receives the flexible bag in the deflated state. The remotely controlled piping device is inserted into the main sewer line so that the piping device can assume a position adjacent to the branch sewer line.The emptied flexible bag is inserted into the drain line using the piping device and filled with a water-based curing agent via a hose so that the curing agent can harden.

[0014] Based on this, it is the object of the present invention to provide a method for repairing a leaky and / or damaged area on an inner wall of the pipeline of a pipeline, in which the inner diameter of the pipeline is not significantly narrowed even after the repair.

[0015] Furthermore, the present invention is based on the object of providing a reliable and robust method for sealing a leaking and / or damaged area on an inner wall of the pipeline of a pipeline, in which foreign bodies such as damaged pipe parts, root growths or other deposits are reliably removed from the pipeline.

[0016] Furthermore, the present invention is based on the object of filling and sealing cavities located outside the pipeline in the area of ​​the leaking and / or damaged area.

[0017] The above objects are achieved according to the invention by a method having the features of claim 1. Advantageous embodiments and further developments of the method are disclosed in subclaims 2 to 15.

[0018] According to the invention, a method is provided for repairing a leaky and / or damaged point in a pipeline, comprising at least the following steps: a) Providing a bellows body b) Positioning the bellows body in the interior of the pipeline adjacent to the leaky and / or damaged point c) Expanding the bellows body until the bellows body seals the pipeline d) Introducing a curable substance into the interior of the pipeline in the region of the leaky and / or damaged point e) Curing the curable substance f) At least partially cutting free the interior of the pipeline.

[0019] A leak, as defined by the present invention, is a location on the inner wall of a pipeline through which either the pipe contents can escape from the pipeline or foreign matter can penetrate the pipeline from the outside. A damaged location, as defined by this invention, includes leaks, but can also refer to damage in its early stages, e.g., a longitudinal or transverse crack on the inner wall of the pipeline, which has not yet led to a leak in the pipeline.

[0020] In the context of the present invention, a bellows body is understood to be a body whose volume can expand upon the introduction of a substance. This volume expansion can occur isotropic or anisotropic (e.g., along a preferred direction). In a cylindrical bellows body with a circular cross-section in a pipeline, the volume expansion occurs primarily in the radial direction, i.e., toward the inner wall of the pipeline. However, the expansion can also occur in all other spatial directions, i.e., both radially and along the bellows body. The bellows body is preferably made of an expandable or elastic material.

[0021] The bellows body should be sealed and mechanically robust, as well as abrasion-resistant to solids. It should contain any introduced substances and ensure that the bellows body is not damaged by the inner wall and / or the solids contained therein when inserted into the pipeline. The bellows body can be designed, for example, as a balloon or tube, with one area of ​​the bellows body preferably having a thinner material. The bellows body can be expanded preferentially at this point. For example, the bellows body is coated three times, whereas the area opposite the inlet is coated only twice.

[0022] In one embodiment, the bellows body is introduced into the pipeline using a protector. This protector can be designed, for example, as a protective cap. The protective cap can be approximately hemisphere-shaped and can additionally have a taper at the opening, which serves to secure the bellows body inside the protective cap. The protector can break open when the bellows body expands. Furthermore, the protector can have a predetermined breaking point at which the protector preferably breaks open when the bellows body expands. This predetermined breaking point is designed as a material taper, for example as a notch, perforation, or scored mark. The protector is preferably made of plastic.

[0023] When positioning the bellows body inside the pipeline adjacent to the leaking and / or damaged area, the bellows body should be advanced until it has completely passed the leaking and / or damaged area. The bellows body should not cover the leaking and / or damaged area. Preferably, there should be a gap between the leaking and / or damaged area and the position of the bellows body. This gap is also preferably approximately 10 cm. This gap ensures complete repair of the leaking and / or damaged area.

[0024] The bellows body should be positioned within the pipeline so that the leaking and / or damaged area on the inner wall of the pipeline is freely accessible and can then be repaired. In a third step, after the bellows body has been positioned as described above, the bellows body expands until it seals the pipeline. "Sealing" in the context of the present invention refers to closing the pipeline so that substances cannot pass through the pipeline around the bellows body.

[0025] In the next step, a hardenable substance is introduced into the interior of the pipeline in the area of ​​the leaking and / or damaged spot. Sufficient hardenable substance is introduced to cover the leaking and / or damaged spot. The hardenable substance within the meaning of this invention can be any substance that is initially liquid, foam-like, or pasty and that hardens over time with or without the influence of atmospheric oxygen, water, light of a specific wavelength, or chemical substances. Preferably, sufficient substance is introduced to cover an area of ​​approximately 10 cm in addition to the leaking and / or damaged spot in the pipeline. This ensures complete and permanent repair of the leaking and / or damaged spot.

[0026] By introducing the hardenable substance, this substance can penetrate through the leak into the area outside the pipeline and thus at least largely fill any cavities in this area as well. This ensures that the pipeline is also protected from further external influences in this area. In addition, the hardenable substance completely encloses any solids that have penetrated inside the pipeline, such as roots, stones, or soil. The hardenable substance distributes itself around these solids within the pipeline and embeds them. Therefore, once the substance has hardened, the solids can no longer move into this area of ​​the pipeline's interior.

[0027] The curable material is then cured. Curing can occur with or without exposure to air, water, light of a specific wavelength, or chemical substances. The process can therefore be used for any suitable substance.

[0028] In the next step, the interior of the pipeline is at least partially cut free. This cutting can be done, for example, using a milling cutter that is inserted into the interior of the pipeline. The milling head of this milling cutter preferably has a diameter that corresponds to the diameter of the pipeline. However, milling heads with a diameter smaller than the diameter of the pipeline can also be used. With such an embodiment, however, care should be taken to ensure that the curable material in the pipeline and, if applicable, the bellows body are milled out in the final step to such an extent that no constriction of the inner diameter occurs in this area of ​​the pipeline.

[0029] As a result of the cutting process, both the hardened material, to the extent it lies within the pipeline, and the inserted bellows body should be completely reduced in size until the hardenable material at least seals the leaking and / or damaged area on the inner wall of the pipeline. Portions of the hardenable material that have penetrated through the leak into the outer area of ​​the pipeline and completely or partially fill the cavities located there remain untouched by the cutting process.

[0030] After carrying out the method according to the invention, the leaky and / or damaged area on the inner wall of the pipeline is therefore completely sealed by the hardenable substance, the area outside the leaky area in the pipeline is additionally protected from impacts and all solids previously present in the area of ​​the pipeline, such as pipe parts, soil, stones, dust, etc., are completely removed from the pipeline.

[0031] In a preferred embodiment, the inner diameter of the pipeline in the area of ​​the leaking and / or damaged area after repair is essentially the same as in an undamaged area of ​​the pipeline. Between the cut-free area and the remaining areas of the pipeline, no edges or leaks form where deposits could form or through which substances from outside could penetrate into the pipeline, or through which substances present in the pipeline could escape to the outside.

[0032] In one embodiment, the curable substance is introduced through at least one hose connection from a pump located outside the pipeline into the interior of the pipeline and / or the bellows body, and the hose connection is withdrawn before curing. This prevents the hose connections from becoming firmly enclosed in the introduced substance after it has cured. The hose connection can thus be reused after the introduction of the curable substance and, in particular, can be used to introduce the curable substance after the bellows body into the area of ​​the leaking and / or damaged part of the pipeline.

[0033] In one embodiment, the curable substance consists of several components that are introduced separately and mixed in situ. Provision can be made for a separate hose connection for each component to be introduced from a pump located outside the pipeline, and for the hose connections to be removed before the substance cures. The use of separate hose connections ensures that the components only combine with each other within the pipeline and / or the bellows body, where they react with each other and form the curable substance. The separate hose connections prevent the curable substance from reacting within a hose connection and clogging the hose connection.

[0034] A further aspect of the invention is a spray head which is suitable for mixing at least two components in situ and then applying them within the pipeline. The spray head is preferably made of plastic and has at least two inlets via which, for example, hoses can be connected. The spray head also has a mixer which is preferably cylindrical and, inside, a rotating drum with circularly arranged blades which are mounted on a ball bearing. The spray head can be constructed in one piece or from at least two parts. Opposite the inlets, the mixture of components is distributed via a nozzle. The spray head can be used both for the curable substance and for a subsequent coating.Compared to previously known metal versions, the spray head has the advantage of being cost-effective and can therefore be used as a disposable material, which saves working time and cleaning agents.

[0035] In one embodiment, a PU material is introduced as the curable substance. The PU material can be, for example, a one-component PU material and / or a PU foam. Corresponding materials and foams are known to those skilled in the art from other applications. In an advantageous embodiment, a two-component PU foam is introduced as the PU material. With a two-component PU foam, the components can be fed through two hoses from the component storage container into the pipeline and / or the bellows body. In this embodiment, the two components only mix in the area in the pipeline or the bellows body into which the PU material is to be introduced. Before the PU material cures, the two hoses are removed from the pipeline.

[0036] In one embodiment, an epoxy resin is introduced as the curable material. For the purposes of the invention, epoxy resins include all synthetic resins containing epoxy groups that, when mixed with a hardener, react to form a thermosetting plastic. After curing, epoxy resins possess good mechanical properties and are particularly suitable for sealing pipelines.

[0037] Furthermore, the invention provides for the hardenable substance to be introduced into the interior of the pipeline by means of a pumping device located outside the pipeline. Particularly for pipelines where the leaking and / or damaged area is far from the access opening of the pipeline, powerful pumping devices are recommended, allowing the hardenable substance to be pressed from the storage container through hose connections into the bellows body and / or the area of ​​the leaking and / or damaged area. The pumping device ensures that the hardenable substance or its components can be transported quickly and safely to the desired location within the pipeline.

[0038] After the material has cured, in one embodiment, the entire inner diameter of the pipeline can be completely filled and sealed by the bellows body, including the leaking and / or damaged area. This is easily achieved by applying a sufficient amount of curable material.

[0039] In one embodiment, the cured substance will not completely fill the interior of the pipeline in the area of ​​the leaking and / or damaged area. This has the advantage that when cutting out the treated area in a non-straight section of the pipeline, the pipeline's path can be followed. Completely filling the pipeline would pose the risk of breaking through the pipeline in a straight line during the cutting process.

[0040] In one embodiment, the curable substance is introduced into the interior of the pipeline using a spray device. Spray devices are particularly suitable for use with PU foam. This allows the curable substance to be distributed particularly evenly and in minimal quantities, reducing the required quantity.

[0041] For shorter distances between the access opening of the pipeline and the leaking and / or damaged area in the inner wall of the pipeline, a spray can can also be used as a spraying device, which uses a propellant gas to transport the hardenable substance through the hose connection to the leaking and / or damaged area within the pipeline.

[0042] In another embodiment, a spray gun is used as the spraying device. To increase the efficiency of the spray gun, the spray gun can be operated with compressed air or another compressed gas. The spray gun is connected to a compressor, which feeds the compressed air into the spray gun and transports the curable substance through the hose connection to the leaking and / or damaged area within the pipeline.

[0043] In one embodiment, the bellows body is a plastic bag. This design is particularly cost-effective. The plastic bag must be dimensioned so that it can be easily inserted into the pipeline when empty and that it seals the pipeline after being filled with a hardenable substance. Plastic bags are lightweight and inexpensive to obtain. Furthermore, they are easy to remove afterward.

[0044] In one embodiment, the bellows body is expanded with the curable material. The curable material can be the same or a different one used to repair the leaking and / or damaged area. In another embodiment, the bellows body is expanded with a gas, preferably air, nitrogen, or carbon dioxide, and / or a liquid, preferably water. This reduces the need for the curable material and thus saves costs.

[0045] In one embodiment, step g) is additionally carried out, g) applying a coating to the interior of the pipeline in the area of ​​the leaky and / or damaged spot. This serves to subsequently seal the treated area, leads to improved durability and protects the pipeline from further damage. The flow of the substance conveyed through the pipeline is also improved. In particular, according to the method according to the invention, the pipeline is to be coated in the treated area of ​​the previously leaky and / or damaged area within the pipeline, which area has been cut free. In this area, in particular, unevenness may still exist on the inner wall of the pipeline. The unevenness can be compensated for by the coating, so that a uniform inner wall of the pipeline is once again created.

[0046] In one embodiment, in step g), a coating of a curable resin is applied and then cured. The resin is applied in liquid form to the inner wall of the pipeline. There, it hardens and then forms a smooth and uniform inner wall of the pipeline. As the resin cures, a hard and durable coating forms inside the pipeline.

[0047] In a preferred embodiment, the coating is applied using at least one rotating brush head. In this embodiment, the brush head is coated with a coating material. When this brush head is then moved through the pipeline, the rotating brush head applies the coating material evenly to the inner wall of the pipeline.

[0048] Another method involves applying the coating using a spray device. The coating material is applied to the inner wall of the pipeline via this spray device. Moving the spray device through the pipeline results in an even application of the coating material to the inner wall of the pipeline. In one embodiment, in step g), a fabric hose impregnated with a curable resin is inserted and then cured. The resin-impregnated hose is made either of felt or polyester fabric. This resin-impregnated hose adheres to the inner wall of the pipeline. Once cured, the hose forms the inner wall of the pipeline. The cured hose forms an even more durable coating on the leaking and / or damaged area. The resin-impregnated hose can be inserted into the pipeline using an inversion drum.The inversion drum is a pressure vessel that builds up sufficient pressure to pull the resin-impregnated hose into the pipeline.

[0049] In one embodiment, in step d) or g), an agent is introduced into the bellows body and / or the pipeline that accelerates and / or improves the curing of the substance and / or resin. The hose connection can, for example, consist of a heating hose through which the curable substance is heated and its reaction is accelerated. Alternatively, air or water can be introduced into the curable substance via the hose connection if the curable substance reacts faster and better with air or water. Likewise, a lamp can be introduced that emits light at a specific wavelength if the curable substance reacts faster and better in this way.

[0050] In a further embodiment of the method according to the invention, after the hardened material and the bellows body have been cut free, the pipeline is rinsed with water in order to transport the cut-out material out of the pipeline. During the cutting free process, the hardened material and, if applicable, the bellows body are crushed. The resulting cut-out material then initially deposits at the bottom of a horizontal pipeline or at the next bend in a vertical or inclined pipeline. To prevent the pipeline from becoming blocked by the cut-out material, a gas, preferably air, nitrogen, carbon dioxide, or a liquid, preferably water, is introduced into the pipeline under pressure so that the cut-out material is transported further from its deposit location in the pipeline.

[0051] In another embodiment of the method according to the invention, the cut-out material is vacuumed out of the pipeline using negative pressure. In this method, the cut-out material is not conveyed into the pipeline as in the previous method, but rather is vacuumed out through the access opening to the pipeline. This method has the advantage that no cut-out material remains in the pipeline, thus preventing deposits and / or blockages further along the pipeline.

[0052] In a further embodiment of the method according to the invention, before the bellows body is positioned, a mobile camera is first inserted into the pipeline in order to examine the interior of the pipeline and to locate leaks and / or damage on the inner wall of the pipeline. The mobile camera is used to examine the interior of the pipeline to determine where leaks and / or damage to the inner wall of the pipeline are present. In this way, it is possible to determine exactly where the bellows body is to be positioned within the pipeline and where the inner wall of the pipeline is to be repaired using the method according to the invention. After the hardenable substance has been introduced, the camera can be used to check whether enough of the substance has been introduced.

[0053] The invention further relates to a kit of parts for carrying out a method according to the invention. The kit comprises at least one bellows body that can be inserted into a pipeline, a pump for introducing a curable substance into the bellows body, and a curable substance that can be introduced into the bellows body.

[0054] The parts kit may also include a protective cap for the bellows body.

[0055] According to a further embodiment of the invention, the kit comprises a spray head which is suitable for mixing at least two components in situ and then applying them within a pipeline.

Claims

Patent claims 1. Method for repairing a leaky and / or damaged area in a pipeline, comprising the following steps: a) Providing a bellows body b) Positioning the bellows body in the interior of the pipeline adjacent to the leaky and / or damaged area c) Expanding the bellows body until the bellows body seals the pipeline d) Introducing a hardenable substance into the interior of the pipeline in the region of the leaky and / or damaged area e) Hardening the hardenable substance f) At least partially cutting free the interior of the pipeline.

2. Method according to claim 1, characterized in that the curable substance consists of several components which are introduced separately and mixed in situ.

3. Method according to one of the preceding claims, characterized in that a PU material is introduced as the curable substance.

4. Method according to claim 3, characterized in that a two-component PU foam is introduced as the PU material.

5. Method according to one of the preceding claims, characterized in that an epoxy resin is introduced as the curable substance.

6. Method according to one of the preceding claims, characterized in that the hardened substance does not completely fill the interior of the pipeline in the region of the leaking and / or damaged area.

7. Method according to one of the preceding claims, characterized in that the inner diameter of the pipeline in the region of the leaking and / or damaged area after repair is substantially the same as a non-damaged area of the pipeline.

8. Method according to one of the preceding claims, characterized in that the hardenable substance is introduced into the interior of the pipeline by means of a spray device.

9. Method according to one of the preceding claims, characterized in that the bellows body is a plastic bag.

10. Method according to one of the preceding claims, characterized in that the bellows body is expanded with the curable material.

11. Method according to one of the preceding claims, characterized in that the bellows body is expanded with a gas, preferably air, nitrogen or carbon dioxide, and / or a liquid, preferably water.

12. Method according to one of the preceding claims, characterized in that step g) is additionally carried out, g) applying a coating in the interior of the pipeline in the region of the leaking and / or damaged area.

13. The method according to claim 10, characterized in that in step g) a coating of a curable resin is applied and subsequently cured.

14. The method according to claim 10 or 11, characterized in that in step g) a fabric tube impregnated with a curable resin is introduced and subsequently cured.

15. Method according to one of the preceding claims, characterized in that in step d) or g) an agent is introduced into the bellows body and / or the pipeline that accelerates and / or improves the curing of the substance and / or resin.

16. Kit of parts for carrying out a method according to one of claims 1 to 15, at least comprising a bellows body which can be introduced into a pipeline, a pump for introducing a curable substance into the bellows body and a curable substance which can be introduced into the bellows body.

17. Kit of parts according to claim 16, further comprising a protective cap for the bellows body.

18. Kit according to one of claims 16 or 17, further comprising a spray head adapted to mix at least two components in situ and then apply them within a pipeline.