Multi-layer corrugated pipe outer jacket and this comprehensive pipe arrangement

Abstract

The present invention relates to a multi-layer corrugated pipe outer casing (10) for accommodating at least one media pipe (100) for conducting a fluid, said pipe comprising an inner layer (20); a connecting layer (30) arranged on the inner layer (20) and connected to the inner layer (20) at least in sections; and a corrugated outer protective layer (40) arranged on the connecting layer (30) and having corrugated pipe peaks (41, 41') and corrugated pipe valleys (42, 42'). The protective layer (40) is connected to the connecting layer (30) in the region of the corrugated pipe valleys (42, 42'). Furthermore, the present invention relates to a pipe arrangement (100) comprising a multi-layer corrugated pipe outer casing (10) according to the invention and at least one media pipe (50) accommodated therein for conducting a fluid.

Description

The present invention relates to a multi-layered corrugated pipe outer jacket for receiving at least one media pipe for guiding a fluid. The present invention furthermore relates to a pipe arrangement, to such a multilayer corrugated pipe outer jacket and to at least one medium pipe accommodated therein for guiding a fluid.Corrugated pipe outer jackets are fundamentally known in the prior art and are used in particular in thermally insulated pipe arrangements, for example in near-end and district heating networks. For example, single-walled flexible corrugated plastic pipes are available on the market. These can easily be damaged by storage, transport or carelessly treating them at the construction site, so that water can penetrate into the corrugated pipe from the outside. In order to overcome this disadvantage, there are two-layer corrugated tube outer jackets on the market, in which a plastic inliner is arranged in the corrugated outer layer. Such two-layer corrugated pipe outer jackets are already less prone to damage on site. If damage nevertheless penetrates, so that water, for example in the form of rainwater or groundwater, reaches the interior of the corrugated tube outer jacket, it is not ensured that a heat distribution system comprising such a corrugated tube outer jacket does not run partially or completely through water and in this way becomes unusable, which can only be eliminated at great expense and is associated with high costs. Particularly high costs for rehabilitation occur especially when large quantities of water enter a building in an uncontrolled manner due to the damaged heat distribution system.At this point, the present invention uses the object of making available a multilayer corrugated tube outer jacket which at least partially overcomes the disadvantages of the prior art. In particular, the multilayer corrugated tube outer jacket according to the invention is intended to offer increased safety against the penetration of water in the event of damage to the outer layer. In addition, the flexibility of bending of a typical corrugated pipe should be maintained while at the same time providing high annular rigidity. Finally, the object of the present invention is also to provide a pipe arrangement which comprises such a multilayer corrugated pipe outer jacket.These and other objects are achieved according to the invention by a multi-layered corrugated pipe outer jacket having the features of claim 1 or by a pipe arrangement having the features of claim 10. Preferred embodiments of the multilayer corrugated tube outer jacket according to the invention and of the tube arrangement according to the invention are described in each case in the dependent claims.According to the present invention, it has been found that for a multilayer corrugated tube outer jacket a balanced balance of corrugated tube-typical high bending flexibility and at the same time high hoop rigidity is achieved if the corrugated tube outer jacket is constructed in three layers, wherein the middle layer is connected both to the inner layer and to the corrugated outer protective layer. The connection of the middle layer to the outer protective jacket in the region of the corrugation troughs thereof ensures that water once it has passed through the outer protective jacket cannot continue to flow in the longitudinal direction of the multilayer corrugated tube outer jacket according to the invention. The inner layer is preferably connected, in particular welded or bonded, over its full surface to the middle layer, while the outer layer is, independently thereof, preferably connected, in particular welded or bonded, circumferentially to the middle layer in the region of the corrugated tube troughs.Accordingly, the present invention lies in the provision of a multi-layered corrugated tube outer jacket for receiving at least one media tube for guiding a fluid, which comprises an inner layer; a connecting layer arranged on the inner layer and connected at least in sections to the inner layer; and a corrugated outer protective layer arranged on the connecting layer, which protective layer has corrugated tube peaks and corrugated tube valleys, wherein the protective layer is connected to the connecting layer in the region of the corrugated tube valleys. In addition, the present invention provides a pipe arrangement which comprises a multilayer corrugated pipe outer jacket according to the invention and at least one medium pipe accommodated therein for guiding a fluid.With respect to the multilayer corrugated tube outer jacket according to the invention, it can be favorable if the wall thickness of the protective layer is greater in the region of the corrugated tube peaks than in the region of the corrugated tube valleys. It has been found that damage to the multilayer corrugated tube outer jacket according to the invention due to continuous high forces can be reduced by a high wall thickness on the outer side, that is to say on the corrugated tube crests. A smaller wall thickness in the region of the corrugated tube troughs contributes to a high bending flexibility. In preferred embodiments of the multilayer corrugated tube outer jacket according to the invention, the wall thickness of the protective layer is greater in the region of the corrugated tube peaks by 10% to 60%, preferably by approximately 15% to 55%, than in the region of the corrugated tube troughs.It can also prove to be advantageous within the scope of the present invention if the protective layer between two adjacent corrugated tube crests is V-shaped in longitudinal section. As a result, the multi-layered corrugated pipe outer jacket according to the invention is likewise less sensitive to mechanical damage, for example due to larger stones present in the filling material, which stones can no longer penetrate deeply into the V-shaped corrugation troughs tapering downwards. It can be particularly favorable if the V-shaped configuration of the protective layer between two adjacent corrugated tube crests is rounded off towards the connecting layer in the region of the corrugated tube troughs arranged between the adjacent corrugated tube crests. This prevents damage from smaller stones which reach the bottom of the corrugated tube troughs. On the other hand, this increases the contact area between the V-shaped wave troughs and the connecting layer, which contributes to the longitudinal water tightness.It can also be advantageous if the protective layer between two adjacent corrugated tube troughs is configured in the shape of a trough in longitudinal section. This embodiment ensures that the thick material thickness of the corrugated pipe crests is present over a large proportion of the pipe jacket length, which likewise contributes to the damage insensitivity of the multilayer corrugated pipe outer jacket according to the invention. In particularly preferred embodiments of the multilayer corrugated tube outer jacket according to the invention, the trough-shaped configuration of the protective layer between two adjacent corrugated tube troughs has a greater wall thickness in the region of the trough base than in the region of the trough walls. As a result, the high wall thickness is concentrated at the regions of the corrugated outer protective layer directed toward the corrugated tube outer side, which contributes to the high resistance of the multilayer corrugated tube outer jacket according to the invention to damage from the outside.In preferred embodiments of the present invention, the corrugated outer protective layer is formed of or comprises a polymeric material. Preferably, the polymer material is a thermoplastic, in particular a polyolefin. According to the invention, the use of a polyethylene (preferably HDPE, MDPE or LDPE), a polypropylene or a crosslinked polyethylene is preferred.In a particularly preferred embodiment of the present invention, the corrugated outer protective layer can consist of a crosslinked or uncrosslinked polyethylene (PE) or polyethylene copolymers, in an advantageous development of foamed polyethylene with a density of approximately 500 kg / m 3 or contain such a polyethylene. The corrugated outer protective layer is more robust in such a case with comparable flexibility compared to an non-foamed protective layer and has an improved thermal insulation effect.It can also be advantageous if the connecting layer is also formed from a polymer material or comprises a polymer material. Preferably, the polymer material is a thermoplastic, in particular a polyolefin. According to the invention, the use of a polyethylene (preferably HDPE, MDPE or LDPE) or a polypropylene is preferred. Particularly preferably, the connecting layer is designed as a polyethylene film.It can also be helpful if the inner layer has a uniform wall thickness substantially over the entire length of the corrugated tube outer jacket. As a result, the damage resistance of the multilayer corrugated tube outer jacket according to the invention is further increased. In contrast, however, it can also be helpful if the inner layer has a smaller wall thickness in the region of the corrugated tube valleys than in the region of the corrugated tube peaks. A smaller wall thickness of the inner layer in the region of the corrugated tube troughs contributes to the high flexibility of bending of the multilayer corrugated tube outer jacket according to the invention.It is also advantageous if the inner layer is formed from a polymer material or comprises a polymer material. For the inner layer as well, the polymer material is a thermoplastic, in particular a polyolefin. According to the invention, the use of a polyethylene, a polypropylene or a crosslinked polyethylene is preferred. The inner layer is particularly preferably designed as a foam plate made of foamed polyethylene, in particular of foamed crosslinked polyethylene.The explanations with respect to the multilayer corrugated pipe outer jacket according to the invention apply correspondingly with respect to the pipe arrangement according to the invention.With respect to the pipe arrangement according to the invention, it can be helpful if the space between the at least one media pipe and the inner layer is at least partially filled by at least one insulating layer. In this way, a thermally insulated pipe arrangement is obtained which is particularly suitable for use in short-range and district heating networks.It can be advantageous here if the at least one insulation layer is a polyurethane foam (PUR foam). The foam can be formed in a closed cell manner and merely thereby already obstructs the further transport of water in the event of damage to the corrugated pipe outer jacket according to the invention. Preferably, the PUR foam has a density (about 0.04 to 0.10 kg / l) and a low thermal conductivity (about 0.02 to 0.04 W / mK). In this way, good thermal insulation is achieved by the foam, as a result of which the cooling of the medium to be transported by a pipe arrangement according to the invention can be effectively reduced.In preferred embodiments of the pipe arrangement according to the invention, the at least one media pipe is a pipe made of a polymer material, in particular of a thermoplastic, in particular of a polyolefin. The at least one medium tube is particularly preferably a tube made of a polypropylene, a polyethylene or a crosslinked polyethylene, wherein tubes made of crosslinked polyethylene are particularly preferred.It can also be advantageous if the pipe arrangement according to the invention comprises 2, 3 or 4 media pipes in the corrugated pipe outer jacket according to the invention. As a result, a pipe arrangement according to the invention can be adapted to the specifications of the customer or the technology to be applied. In this way, in particular the transport capacity of such a thermally insulated pipe arrangement can be increased by the simultaneous transport of a high fluid volume through a plurality of media pipes and thus correspondingly also the amount of heat transferred.The pipe arrangement according to the invention can comprise at least one barrier layer on or in the protective layer, on or in the at least one insulating layer or on or in the at least one media pipe, which in particular are intended to prevent or prevent the diffusion of oxygen or water vapor or hydrocarbons. These barrier layers may contain in particular polymeric, metallic or inorganic material.All plastic materials in the multilayer corrugated pipe outer jacket according to the invention and in the pipe arrangement according to the invention can also be used in this case in the form of materials obtained by a recycling process.The corrugated tube outer jacket according to the invention and the tube arrangement according to the invention are preferably produced by a coextrusion process, a post coextrusion process or a multistage process. Such a coextrusion process for producing the corrugated pipe outer jacket according to the invention or the pipe arrangement according to the invention can be carried out in particular in a plurality of steps. Thus, in a first step, a medium pipe can be provided by an extrusion process, which in a second step is sheathed by an insulating material. As insulating material, for example, a thin plate of a foamed PUR polymer material can be laid around the media tube and, for example, glued or welded at the joint edges. In parallel with this, the corrugated tube outer jacket according to the invention can be coextruded. For this purpose, the inner layer with the connecting layer welded thereon is passed through an extruder. In this process, the protective layer is extruded and its waveform is generated by a correlator. Subsequently, the insulated media tube can be drawn into the corrugated tube outer jacket according to the invention. However, other techniques of enveloping the media tube with an insulating material are also possible. In particular, it is also possible to produce the insulating layer from PUR foam by reaction of the components forming the PUR foam directly on the media pipe which has already been introduced into the corrugated pipe outer jacket according to the invention, and thus to fill the intermediate space between the at least one media pipe and the corrugated pipe outer jacket according to the invention with the insulating layer during the foaming process.The multilayer corrugated tube outer jacket according to the invention and the tube arrangement according to the invention and individual parts thereof can also be produced line by line or layer by layer using a line-forming or layer-forming production process (e.g. 3D printing), but production by a (co)extrusion process is preferred.The present invention will be explained in detail below with reference to the embodiments illustrated in the figures. Figure shows FIG. 1 is a partial longitudinal sectional view of a corrugated tube multilayer outer shell of an embodiment of the present invention; FIG. 2 is a partial longitudinal sectional view of a multi-layered corrugated tube outer jacket according to a further embodiment of the present invention; and FIG. 3 shows a partial longitudinal sectional illustration of a pipe arrangement according to the invention, which comprises the multi-layered corrugated pipe outer jacket illustrated in FIG. 2.FIG. 1 shows a detail from a schematic longitudinal sectional illustration of a multilayer corrugated tube outer jacket 10 for receiving at least one media tube 50 for guiding a fluid according to an embodiment of the present invention. According to the embodiment shown in FIG. 1, the multilayer corrugated tube outer jacket 10 according to the invention comprises an inner layer 20; a connecting layer 30 arranged on the inner layer 20 and connected at least in sections to the inner layer 20; and a corrugated outer protective layer 40 arranged on the connecting layer 30. In the embodiment shown, the inner layer 20 is welded over its entire surface to the connecting layer 30, while the protective layer 40 is welded circumferentially to the connecting layer 30 in the region of the corrugated tube troughs 42, 42'.In the embodiment shown in FIG. 1, the protective layer 40 is formed thicker in the region of the corrugated tube peaks 41, 41' than in the region of the corrugated tube troughs 42, 42'. The wall thickness of the protective layer 40 in the region of the corrugated pipe peaks 41, 41' is greater by approximately 50% than in the region of the corrugated pipe troughs 42, 42'. Thus, the protective layer 40 according to FIG. 1 is approximately 3 mm thick in the region of the corrugated tube peaks 41, 41', while the wall thickness of the protective layer 40 in the region of the corrugated tube troughs 42, 42" is approximately 2 mm. This high wall thickness on the outer side reduces the risk of damage to the multilayer corrugated tube outer jacket 10 according to the invention as a result of continuous high force actions. In addition, the smaller wall thickness in the region of the corrugated tube troughs 42, 42' contributes to a high bending flexibility.Between two adjacent corrugated tube peaks 41, 41', the protective layer 40 is V-shaped in longitudinal section. Larger stones present in the filling material can thus no longer penetrate deeply into the downwardly tapering V-shaped wave troughs and damage the protective layer 40 there. The V-shape of the corrugated tube troughs 41, 41' is rounded off toward the connecting layer. This prevents damage from smaller stones which reach the bottom of the corrugated tube troughs.Between two adjacent corrugated tube troughs 42, 42' the protective layer 40 is designed in the shape of a trough in longitudinal section. This trough shape has the result that the thick material thickness of the corrugated pipe crests 42, 42' is present over a large proportion of the pipe jacket length, which further increases the insensitivity of the multilayer corrugated pipe outer jacket 10 according to the invention to damage from the outside. The wall thickness of the protective layer 40 is greater in the region of the trough base 411 than in the region of the trough walls 412, 413 adjoining the trough base 411.According to the embodiment shown in Fig. 1, the corrugated outer protective layer 40 is made of high density polyethylene (HDPE).The connecting layer 30 is a polyethylene film with a thickness of 70 μm in the embodiment shown.In the multilayer corrugated tube outer jacket 10 according to the invention shown in FIG. 1, the inner layer 20 is designed as a foam plate made of foamed crosslinked polyethylene and has a uniform wall thickness substantially over the entire length of the corrugated tube outer jacket 10 according to the invention. The wall thickness of the inner layer 20 is 5 mm.FIG. 2 shows a further embodiment of the multilayer corrugated tube outer jacket 10 according to the invention. In order to avoid repetitions, therefore, only differences from the embodiment of the multilayer corrugated tube outer jacket 10 according to the invention shown in FIG. 1 will be described below. The embodiments of FIG. 1 also apply correspondingly to the embodiment of FIG. 2. Identical elements are identified in the figures by identical reference numerals.FIG. 2 shows a further embodiment of the multilayer corrugated tube outer jacket 10 according to the invention in a schematic partial longitudinal sectional illustration. The embodiment shown in FIG. 2 differs from the embodiment described with reference to FIG. 1 only with regard to the distribution of the wall thickness of the inner layer 30 in the longitudinal direction of the corrugated tube outer jacket 10; in this case, the inner layer 20 has a wall thickness in the region of the corrugated tube troughs 42, 42' which is smaller by approximately one third than in the region of the corrugated tube peaks 41, 41'. Due to the smaller wall thickness of the inner layer 20 in the region of the corrugated tube troughs 41, 41', the high bending flexibility of the multi-layered corrugated tube outer jacket 10 according to the invention is further improved.FIG. 3 finally shows a pipe arrangement 100 according to the invention, which fills the multilayer corrugated pipe outer jacket 10 shown in FIG. 2, a medium pipe 50 accommodated therein for guiding a fluid, and an insulating layer 60 which fills the intermediate space between the medium pipe 50 and the inner layer 20 at least partially by at least one insulating layer 60. As a result, the pipe arrangement 100 is designed in the form of a thermally insulated pipe arrangement 100.According to the embodiment shown in FIG. 3, the media tube 50 is formed as a tube of cross-linked polyethylene (PE-X). It comprises a lumen 51 for receiving, storing or conducting the fluid.On the outer surface of the media tube 50, an insulating layer 60 is arranged, which rests with its inner surface against the outer surface of the media tube 50. The insulating layer 60 is formed of a polyurethane layer. In this case, the insulating layer 60 was produced by a polymerization reaction of the components forming the polyurethane, with foaming, directly on the media tube 50. Alternatively, the insulating layer 60 can also be formed as a thin plate made of the polyurethane foam, which is laid around the medium pipe 50 and is bonded or welded at its joint edges in the axial and radial directions.It is understood that the features explained above can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention.The present invention has been explained in detail by way of example with reference to the embodiments illustrated in the figures. It is to be understood that the present invention is not limited to these embodiments. Rather, the scope of the present invention will be apparent from the appended claims.

Claims

Multilayer corrugated tube outer jacket (10) for receiving at least one media tube (100) for guiding a fluid, comprising: an inner layer (20); a connecting layer (30) arranged on the inner layer (20) and connected at least in sections to the inner layer (20); and a corrugated outer protective layer (40) arranged on the connecting layer (30), which has corrugated tube peaks (41, 41') and corrugated tube valleys (42, 42'), wherein the protective layer (40) is connected to the connecting layer (30) in the region of the corrugated tube valleys (42, 42').Multilayer corrugated tube outer jacket (10) according to Claim 1, characterized in that the wall thickness of the protective layer (40) is greater in the region of the corrugated tube peaks (41, 41') than in the region of the corrugated tube valleys (42, 42').Multilayer corrugated tube outer jacket (10) according to either of Claims 1 and 2, characterized in that the protective layer (40) between two adjacent corrugated tube peaks (41, 41') is of V-shaped configuration in longitudinal section.Multilayer corrugated tube outer jacket (10) according to Claim 3, characterized in that the V-shaped configuration of the protective layer (40) between two adjacent corrugated tube peaks (41, 41') is rounded off towards the connecting layer (30) in the region of the corrugated tube valleys (42) arranged between the adjacent corrugated tube peaks (41, 41').Multilayer corrugated tube outer jacket (10) according to one of Claims 1 to 4, characterized in that the protective layer (40) between two adjacent corrugated tube troughs (42, 42') is of trough-shaped configuration in longitudinal section.Multilayer corrugated tube outer jacket (10) according to Claim 5, characterized in that the trough-shaped configuration of the protective layer (40) between two adjacent corrugated tube troughs (42, 42') has a greater wall thickness in the region of the trough base (411) than in the region of the trough walls (412, 413).Multilayer corrugated tube outer jacket (10) according to one of Claims 1 to 6, characterized in that the inner layer (20) has a uniform wall thickness substantially over the entire length of the corrugated tube outer jacket (10).Multilayer corrugated tube outer jacket (10) according to one of Claims 1 to 7, characterized in that the inner layer (20) has a smaller wall thickness in the region of the corrugated tube troughs (42, 42') than in the region of the corrugated tube peaks (41, 41').Multilayer corrugated tube outer jacket (10) according to one of Claims 1 to 8, characterized in that the connection of the inner layer (20) to the connecting layer (30) and the connection of the connecting layer (30) to the protective layer (40) are configured independently of one another as welding and / or bonding.Pipe arrangement (100) comprising a multi-layered corrugated pipe outer jacket (10) according to one of claims 1 to 8 and at least one medium pipe (50) accommodated therein for guiding a fluid.Pipe arrangement (100) according to claim 10, characterised in that the space between the at least one medium pipe (100) and the inner layer (20) is at least partially filled by at least one insulating layer (60).

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