Heatable Tube

Abstract

The invention relates to a heatable tube (1) for conducting fluid, gaseous and/or pasty media, comprising an outer wall (10) that encloses an inner volume (11), and a heating element (2) which is arranged inside the inner volume (11) and which includes a first heating conductor (20a) and a second heating conductor (20b). The heatable tube (1) is characterized in that the first heating conductor (20a) and the second heating conductor (20b) are connected to one another by a heating conductor connector (20c) so as to form a loop in such a way that one heating conductor (20a, 20b) acts as a feed conductor (20a, 20b) and the other heating conductor (20a, 20b) acts as a return conductor (20a, 20b).

Claims

1.-15. (canceled)

16. A heatable hose comprising: an outer wall which encloses an internal volume; and, a heating element which is arranged within the internal volume, the heating element comprising a first heating conductor and a second heating conductor; wherein the first heating conductor and the second heating conductor are connected to form a loop by way of a heating conductor connection, such that the first heating conductor forms a forward conductor and the second heating conductor forms a return conductor.

17. The heatable hose as claimed in claim 16, wherein the heating element is led into the internal volume through at least one first adapter element.

18. The heatable hose as claimed in claim 17, wherein the heating conductor connection is arranged on the opposite side of the at least one first adapter element in relation to the internal volume.

19. The heatable hose as claimed in claim 17, wherein the heating conductor connection is arranged on the same side of the at least one first adapter element as the internal volume.

20. The heatable hose as claimed in claim 16, wherein the first heating conductor, the second heating conductor and the heating conductor connection are one of an electrically conductive cable, an electrically conductive thread or an electrically conductive element.

21. The heatable hose as claimed in claim 20, wherein the first heating conductor, the second heating conductor and the heating conductor connection are a PTC resistor.

22. The heatable hose as claimed in claim 16, wherein the outer wall comprises polyamide, polypthalamide, polyphenylene sulfide, or polyurethane.

23. The heatable hose as claimed in claim 16, wherein the first heating conductor and the second heating conductor are individually or jointly surrounded with respect to the internal volume by a first heating conductor insulator.

24. The heatable hose as claimed in claim 23, wherein a second heating conductor insulator surrounds the first heating conductor insulator.

25. The heatable hose as claimed in claim 16, wherein the first heating conductor, the second heating conductor and the heating conductor connection are individually or jointly surrounded with respect to the internal volume by a first heating conductor insulator.

26. The heatable hose as claimed in claim 25, wherein a second heating conductor insulator surrounds the first heating conductor insulator.

27. The heatable hose as claimed in claim 16, further comprising a first heating conductor insulator comprising perfluoro (ethylene propylene) plastic, modified fluoroalkoxy or perfluoroalkoxy alkane.

28. The heatable hose as claimed in claim 27, further comprising a second heating conductor insulator comprising polyamide, polypthalamide, polyphenylene sulfide, or polyurethane.

29. The heatable hose as claimed in claim 28, further comprising a first adapter element and a second adapter element, wherein the outer wall and at least the second heating conductor insulator are connected by way of one or both of the first adapter element and the second adapter element.

30. The heatable hose as claimed in claim 29, wherein one or both of the first adapter element and the second adapter element comprises an adapter body which is connected to the second heating conductor insulator by way of a cohesive connection.

30. The heatable hose as claimed in claim 30, wherein the cohesive connection is a laser-welded connection, a rotary-welded connection, or an adhesive connection.

31. A heatable hose comprising: an outer wall which encloses an internal volume; and, a heating element which is arranged within the internal volume, the heating element comprising a first heating conductor and a second heating conductor; wherein the first heating conductor and the second heating conductor are connected to form a loop by way of a heating conductor connection, such that the first heating conductor forms a forward conductor and the second heating conductor forms a return conductor; and, wherein the first heating conductor, the second heating conductor and the heating conductor connection are a PTC resistor.

32. The heatable hose as claimed in claim 31, wherein the heating element is led into the internal volume through at least one first adapter element.

33. The heatable hose as claimed in claim 32, wherein the heating conductor connection is arranged on the opposite side of the at least one first adapter element in relation to the internal volume.

34. The heatable hose as claimed in claim 32, wherein the heating conductor connection is arranged on the same side of the at least one first adapter element as the internal volume.

35. A heatable hose comprising: an outer wall which encloses an internal volume; and, a heating element which is arranged within the internal volume, the heating element comprising a first heating conductor and a second heating conductor; a first adapter element and a second adapter element; a first heating conductor insulator comprising perfluoro (ethylene propylene) plastic, modified fluoroalkoxy or perfluoroalkoxy alkane; and, a second heating conductor insulator comprising polyamide, polypthalamide, polyphenylene sulfide, or polyurethane; wherein the first heating conductor and the second heating conductor are connected to form a loop by way of a heating conductor connection, such that the first heating conductor forms a forward conductor and the second heating conductor forms a return conductor; wherein the outer wall and at least the second heating conductor insulator are connected by way of one or both of the first adapter element and the second adapter element; and, wherein one or both of the first adapter element and the second adapter element comprises an adapter body which is connected to the second heating conductor insulator by way of a cohesive connection.

Description

[0038] Three exemplary embodiments and further advantages of the invention will be discussed below in conjunction with the following figures. In the figures:

[0039] FIG. 1 is a schematic sectional illustration of a heatable hose according to the invention as per a first embodiment;

[0040] FIG. 2 is a schematic sectional illustration of a heatable hose according to the invention as per a second embodiment; and

[0041] FIG. 3 is a schematic sectional illustration of a heatable hose according to the invention as per a third embodiment.

[0042] FIG. 1 is a schematic sectional illustration of a heatable hose 1 according to the invention as per a first embodiment. The heatable hose 1 is of cylindrical form along a longitudinal axis L. The heatable hose 1 is illustrated as being closed, with a first adapter element 3a at its left-hand end and with a second adapter element 3b at its right-hand end.

[0043] The heatable hose 1 has an elastic outer wall 10 composed of an elastomer material, which elastic outer wall encloses an internal volume 11 which is delimited on both sides by the adapter elements 3a, 3b. A medium such as for example a fluid can be conducted within said internal volume 11. In the case of an SCR system, the SCR hose 1 conducts an aqueous urea solution as fluid.

[0044] A heating element 2 in the form of an electrical heating element 2 is arranged, on the longitudinal axis L, in as far as possible freely floating fashion in the internal volume 11 or fluid, which heating element is arranged so as to be uniformly spaced apart in a radial direction R from the inner side of the outer wall 10. This arrangement is however illustrated schematically for better comprehension, because the freely floating electrical heating element 2 adapts to the profile of the hose 1, which may also be curved depending on the application.

[0045] The electrical heating element 2 has a first electrical heating conductor 20a and a second electrical heating conductor 20b in the form of thin copper cables or thin copper-containing cables through which current can flow in order to generate electrical heat losses and, by means thereof, heat the fluid in the internal volume 11. In the case of a supply of direct current (not illustrated), the first electrical heating conductor 20a forms the forward conductor, and the second electrical heating conductor 20b forms the return conductor. The two electrical heating conductors 20a, 20b are connected to one another in current-conducting fashion by way of a heating conductor connection 20c, such that said electrical heating conductors together form one electrical heating conductor 20a, 20b which is arranged in loop-shaped form within the heating conductor 2. In this way, the electrical connectors may be provided on one side of the heatable hose 1.

[0046] The two electrical heating conductors 20a, 20b and the heating conductor connection 20c are jointly encased by a first heating conductor insulator 21 which substantially chemically insulates said electrical heating conductors with respect to liquids and which at the same time permits a good transfer of heat to the internal volume 11. Furthermore, the first heating conductor insulator 21 is lined with a second heating conductor insulator 22 which additionally in particular chemically insulates the first heating conductor insulator 21 with respect to the internal volume 11 or the fluid such as for example the aqueous urea solution. In this way, the advantage of the direct transfer of heat of the freely floating electrical heating element 2 can also be utilized in usage situations with chemically aggressive fluids such as the aqueous urea solution of an SCR system. The electrical heating conductors 20a, 20b and the heating conductor connection 20c are in this case completely enclosed, as far as the connectors on the right-hand side, by the two heating conductor insulators 21, 22, such that fluid-tight insulation can be realized.

[0047] The adapter elements 3a, 3b have in each case one adapter body 30 which is connected to the second heating conductor insulator 22 in pressure-tight fashion by way of a cohesive connection 31, such as for example a laser-welded or rotary-welded connection 31 or an adhesive connection 31. Via the adapter bodies 3a, 3b, the fluid can be exchanged between the internal volume 11 and the surroundings, such as for example other hoses or assemblies (not illustrated).

[0048] FIG. 2 is a schematic sectional illustration of a heatable hose 1 according to the invention as per a second embodiment. In this case, the heating conductor connection 20c is arranged in a separate closure element 23 which is mounted onto the end of the two heating conductors 20a, 20b on the left-hand side after said heating conductors have been led out of the internal volume 11 through the first adapter element 3a. In this way, the heating conductor can be produced in a continuous length and can be cut to size and processed for the respective application, which can make the production process simpler and cheaper.

[0049] The closure by way of the heating conductor connection 20c is then realized, on the finished product, by way of the closure element 23.

[0050] FIG. 3 is a schematic sectional illustration of a heatable hose 1 according to the invention as per a third embodiment. In this case, the heating conductor 2 is designed as in the first embodiment, but ends within the internal volume 11 at the inner side of the first adapter element 3a. At this location, the heating conductor 2 can be fastened in preferably cohesive fashion. In this way, it is possible to dispense with a passage through the first adapter element 3a, which at the same time rules out leakage problems at said passage.

[0051] In all three embodiments, the two heating conductors 20a, 20b are jointly encased firstly by the first heating conductor insulator 21 and then by the second heating conductor insulator 22. Alternatively, the two heating conductors 20a, 20b may also be in each case spatially separately encased by the same first heating conductor insulator 21 or else by different first heating conductor insulators 21 and then by the common second heating conductor insulator 22 which, in this case, separates the two first heating conductor insulators 21 from one another, that is to say is also arranged between 20a and 20b. This can simplify the production because the two heating conductors 20a, 20b with their respective first heating conductor insulator 21 can be produced separately and are thereafter brought together for the first time within the second heating conductor insulator 22. It is also possible for the second heating conductor insulator 22 to encase the two heating conductors 20a, 20b separately, such that a spacing can form between these.

LIST OF REFERENCE SIGNS

(Part of the Description)

[0052] L Longitudinal axis [0053] R Radial direction, perpendicular to longitudinal axis L [0054] 1 (Electrically) heatable hose, SCR hose [0055] 10 Outer wall [0056] 11 Internal volume [0057] 2 (Electrical) heating element [0058] 20a First (electrical) heating conductor, forward conductor [0059] 20b Second (electrical) heating conductor, return conductor [0060] 20c Heating conductor connection [0061] 21 First heating conductor insulator [0062] 22 Second heating conductor insulator [0063] 23 Closure element [0064] 3a First adapter element, first connector element, first quick connector [0065] 3b Second adapter element, second connector element, second quick connector [0066] 30 Adapter body, connector body [0067] Cohesive connection between second heating conductor insulator 22 and adapter body 30, laser-welded connection, rotary-welded connection, adhesive connection