PRE-FABRICATED HEATABLE MEDIA LINE AND PRE-FABRICATED HEATING ELEMENT FOR USE IN SAME

Abstract

A pre-fabricated heatable media line having at least one pipe- and/or hose-type media line, at least one line connector located on the end of said line and at least one pre-fabricated heating element, the pre-fabricated heating element including at least two heating element portions connected in at least one circuit and at least one of the heating element portions extends over at least part of the at least one line connector and the at least one pipe- and/or hose-type media line in order to heat the at least one part of the line connector and the at least one pipe- and/or hose-type media line. In said pre-fabricated heatable media line, at least one of the heating element portions is designed as a mixed stranded wire having a number of stranded individual wires consisting of at least two different materials.

Claims

1. A pre-fabricated heatable media line, comprising at least one pipe-type and/or hose-type media line, at least one-line connector arranged at an end of the latter, and with at least one pre-fabricated heating element, wherein the pre-fabricated heating element comprises at least two heating element portions, which are connected in at least one circuit, and at least one of the heating element portions extends over at least one part of the at least one line connector and the at least one pipe-type and/or hose-type media line, for purposes of heating the at least one part of the line connector and the at least one pipe-type and/or hose-type media line, wherein at least one of the heating element portions is designed as a mixed wire strand, which has a number of twisted individual wires, consisting of at least two different materials.

2. The pre-fabricated heatable media line according to claim 1, wherein two heating element portions that are connected together both have the same cross-sectional areas.

3. The pre-fabricated heatable media line according to claim 1, wherein two interconnected heating element portions each have a minimum cross-sectional area of 0.15 mm.sup.2.

4. The pre-fabricated heatable media line according to claim 1, wherein the at least one pipe-type and/or hose-type media line and the at least one line connector are adaptively wrapped with the at least one pre-fabricated heating element.

5. The pre-fabricated heatable media line according to claim 1, wherein at least one of the twisted individual wires of the at least one heating element portion consists of a copper-zinc alloy, or a copper-tin alloy.

6. The pre-fabricated heatable media line according to claim 1, wherein the pre-fabricated heating element comprises two or three heating element portions.

7. The pre-fabricated heatable media line according to claim 1, wherein the at least one heating element portion designed as a mixing strand comprises seven twisted individual wires.

8. The pre-fabricated heatable media line according to claim 1, wherein with the twisting of the individual wires to form the at least one heating element portion the lay length (l.sub.s) is 6 to 15 mm.

9. The pre-fabricated heating element for use in a pre-fabricated heatable media line according to claim 1, wherein the pre-fabricated heating element comprises at least two series-connected heating element portions, wherein at least one of the two heating element portions is designed as a mixed stranded wire, having a number of twisted individual wires consisting of at least two different materials.

10. The pre-fabricated heating element according to claim 9, wherein the at least one heating element portion designed as a mixed stranded wire, has a cross-sectional area of 0.15 to 0.37 mm.sup.2.

11. A method for fixation of at least one pre-fabricated heating element according to claim 9, onto a media line for purposes of forming a heatable media line, comprising the steps of: providing at least one pipe-type and/or hose-type media line provided with the at least one pre-fabricated heating element, and the at least one pre-fabricated heating element, by means of at least partially wrapping around of the media line, provided with the latter, with at least one film element, are fixed on the latter, and heating the media line provided with the at least one pre-fabricated heating element, and the at least one film element for purposes of better embedding of the pre-fabricated heating element in the film element, and better placement of the latter on the outer surface of the media line.

12. The method in according to claim 11, wherein the at least one film element is stretched, and/or overextended, and/or plastically deformed, during the winding of the media line with the at least one heating element arranged on the latter.

13. The pre-fabricated heatable media line according to claim 3, wherein the two interconnected heating element portions each have a minimum cross-sectional area of 0.2 mm.sup.2.

14. The pre-fabricated heating element according to claim 8, wherein with the twisting of the individual wires to form the at least one heating element portion the lay length (l.sub.s) is 9 mm.

15. The pre-fabricated heating element according to claim 10, wherein the at least one heating element portion designed as the mixed stranded wire has a cross-sectional area of 0.17 to 0.23 mm.sup.2.

16. The pre-fabricated heating element according to claim 15, wherein the at least one heating element portion designed as the mixed stranded wire has a cross-sectional area of 0.20 mm.sup.2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] For further explanation of the invention embodiments of the latter will be described in more detail below with reference to the figures. Here:

[0032] FIG. 1 shows a schematic diagram of a first embodiment of an inventive pre-fabricated heatable media line with two end connectors attached to a pipe-type media line, and two series-connected heating element portions to form a pre-fabricated heating element,

[0033] FIG. 2 shows a schematic diagram of a second embodiment of an inventive pre-fabricated heatable media line, with two-line connectors attached to the ends of a pipe-type media line, and two heating element portions,

[0034] FIG. 3 shows a schematic diagram of a third embodiment of an inventive pre-fabricated heatable media line, with two-line connectors attached to the ends of a pipe-type media line, and two heating element portions, as a modification to the embodiment in FIG. 1,

[0035] FIG. 4 shows a schematic diagram of a fourth embodiment of an inventive pre-fabricated heatable media line, with two-line connectors attached to the ends of a pipe-type media line, and two series-connected heating element portions to form a pre-fabricated heating element,

[0036] FIG. 5 shows a schematic diagram of a fifth embodiment of an inventive pre-fabricated heatable media line, with two-line connectors attached to the ends of a pipe-type media line, and four heating element portions, wherein two of the heating element portions extend along the pipe-type media line, and in each case a heating element portion extends onto each of the line connectors,

[0037] FIG. 6 shows a schematic diagram of a sixth embodiment of an inventive pre-fabricated heatable media line, with two line connectors attached to the ends of a pipe-type media line, and three heating element portions, of which one just extends onto the one line connector, one extends essentially along the pipe-type media line, and the third extends along the pipe-type media line and along the second line connector,

[0038] FIG. 7 shows a cross-sectional view through an inventive media line with a pre-fabricated heating element with a comparatively small outer diameter arranged on the latter,

[0039] FIG. 8 shows a cross-sectional view through an inventive media line with a pre-fabricated heating element with a comparatively larger outer diameter arranged on the latter,

[0040] FIG. 9 shows a cross-sectional view through an inventive line connector with a pre-fabricated heating element arranged between its outer surface ribs,

[0041] FIG. 10 shows a schematic diagram of a seventh embodiment of an inventive pre-fabricated heatable media line, with two-line connectors attached to the ends of a pipe-type media line, and two heating element portions, as a modification to the embodiment in FIG. 4,

[0042] FIG. 11 shows a schematic diagram of an eighth embodiment of an inventive pre-fabricated heatable media line, with two-line connectors attached to the ends of a pipe-type media line, and four heating element portions, wherein two of the heating element portions extend along the pipe-type media line and are connected to one another, and one heating element portion extends onto each of the line connectors,

[0043] FIG. 12 shows a schematic diagram of a ninth embodiment of an inventive pre-fabricated heatable media line, with two-line connectors attached to the ends of a pipe-type media line, and two heating element portions, wherein the one heating element portion extends along the pipe-type media line and a portion of the one-line connector and the other heating element portion extends onto the other line connector,

[0044] FIG. 13 shows a side detail view of seven twisted individual wires of an inventive heating element portion designed as a mixed stranded wire,

[0045] FIG. 14 shows a cross-sectional view through the inventive heating element portion designed as a mixed wire strand, as in FIG. 13, comprising seven individual wires twisted together around a high tensile strength support element,

[0046] FIG. 15 shows a schematic diagram of a pipe- or hose-type media line with two heating elements arranged wound around the latter, and

[0047] FIG. 16 shows a schematic diagram of the media line provided with the two heating elements as in FIG. 15, wherein for purposes of a fixation of the heating elements on the media line the latter is partially wrapped around with a film element.

DETAILED DESCRIPTION OF THE INVENTION

[0048] FIG. 1 shows a pre-fabricated heatable media line 1 with a pipe-type media line 2 and two line connectors 3, 4 attached to the ends of the latter. The connection of the pipe-type media line 2 and the two-line connectors 3, 4 can be affected as a form fit, and/or a force fit, or also as a material bond. Instead of a pipe-type media line 2, a hose-type media line can also be provided. It is also possible for the media line to be pipe-type and/or hose-type, with at least one pipe-type section and at least one hose-type section.

[0049] Along the media line 1 extends a pre-fabricated heating element 5, which in accordance with FIG. 1 is formed from two series-connected heating element portions 50, 51, connected together at a connection point 52, in particular a crimping point. The heating element portion 50 extends along the pipe-type media line 2, onto the first line connector 3 and into the transition region 21 from the pipe-type media line 2 to the second line connector 4. The second heating element portion 51 also extends along the pipe-type media line 2, furthermore onto the second line connector 4 and into the transition region 20 between the pipe-type media line 2 and the first line connector 3. The connection point 52 is arranged on the second line connector 4, such that the heating element portion 50 extends as far as the latter. On the first line connector 3 the two ends 53, 54 of the two heating element portions 50, 51 are connected to electrical supply lines 6, 7, in particular by means of crimping, via which a connection to an electrical power supply can be affected, so as to enable heating. Thus, no connection point is provided in the two transition regions 20, 21 between the pipe-type media line 2 and the two-line connectors 3, 4, so that as few heating element portions as possible can be provided, which lowers the cost of the pre-fabricated heatable media line compared with the solutions of the prior art.

[0050] The two heating element portions 50, 51 are each formed as a mixed stranded wire. This means that they are formed from a number of twisted individual wires, which consist of at least two different materials with different specific resistances. An example of such a mixed wire strand in the form of the heating element portion 50 is shown in cross-section in FIG. 14 and in a detail in FIG. 13. In this example, seven individual wires 151, 152, 153, 154, 155, 156 and 157 are twisted around a high tensile strength support element, or a high tensile strength core 150. The lay length ls of the twisted individual wires can be, for example, 6 to 15 mm, in particular 9 mm (see FIG. 13). The twisted composite of the individual wires is usually surrounded on its outer surface by a protective sheath 158, as indicated in FIGS. 13 and 14.

[0051] This consists in particular of a plastic material. By providing such a mixed wire strand for the heating element portions 50, 51 these can be optimally adapted to the particular ambient temperature conditions. If, for example, the region of the pre-fabricated heatable media line 1, on which the first line connector 3 is arranged, is arranged in a hot zone in a vehicle, that is to say, close to the exhaust system or the engine, just a low heat output is required. If, on the other hand, the opposite region of the pre-fabricated heatable media line 1 comprising the second line connector 4 is arranged in a cold zone of a vehicle, such as in the vicinity of a vehicle tank, a higher heat output is required here. This can be adjusted by an appropriate selection of the materials of the individual wires 151 to 157 of the heating element portions 50, 51 in terms of their specific total resistance, since R=(*l)/A, wherein R is the resistance, p is the specific resistance, l is the length of the heating element portion, and A is its cross-sectional area. Accordingly, overheating in the hot zone, and insufficient thawing out, or no thawing out, in the cold zone, can be avoided.

[0052] FIG. 2 shows another arrangement of the two heating element portions 50, 51 along the pipe-type media line 2 and on the two-line connectors 3, 4. There the heating element portion 50 extends along the pipe-type media line 2 and onto the first line connector 3 and the second line connector 4. The heating element portion 51 extends only along the pipe-type media line 2 and over the transition regions 20, 21 onto the first line connector 3 and the second line connector 4. The ends 53, 54 and 55, 56 of the two heating element portions 50, 51 are arranged on the two-line connectors 3, 4. Accordingly, electrical supply lines 6, 7 can be connected to the ends 53, 54 and 55, 56, respectively, or the ends 53, 54 and 55, 56 respectively can be short-circuited. A suitable selection can be made depending on the particular application.

[0053] The embodiment of the pre-fabricated heatable media line 1 in FIG. 3 differs from that in FIG. 1 in that the ends 55, 56 of the two heating element portions 50, 51 are not crimped together at the connection point 52, but are free, so that these can be connected together and thereby short-circuited, or can be connected to the said electrical supply lines 6, 7.

[0054] In the embodiment variant of FIG. 4, in contrast to the embodiment of the pre-fabricated heatable media line 1 in FIG. 2, the two ends 53, 54 of the two heating element portions 50, 51 are fixedly connected together at a connection point 57, such as a crimping point. The latter is arranged on the first line connector 3, or can be arranged on the pipe-type media line 2, as indicated by the dashed line.

[0055] Accordingly, the heating element portion 50 does not extend (dashed line) or just over the transition region 20 and in a very short section onto the first line connector 3, so that the first line connector 3 is hardly heated at all, and thus is arranged in a hot zone of a vehicle, that is to say, in a zone in which a high ambient temperature is anticipated.

[0056] In the embodiment variant of the pre-fabricated heatable media line 1 in accordance with FIG. 5, four heating element portions 50, 51, 58, 59 are provided, wherein the two heating element portions 50, 51 are arranged along the pipe-type media line 2 and in the two transitional regions 20, 21; the heating element portion 58 is arranged on the first line connector 3, and the heating element portion 59 is arranged on the second line connector 4. The ends 53, 54, 55, 56 of the heating element portions 50, 51 can be short-circuited, that is to say, connected to the ends 580, 581, 590, 591 of the heating element portions 58, 59, or can be connected to the electrical supply lines 6, 7 for connection to an electrical power supply (not shown).

[0057] FIG. 6 shows a further embodiment variant of the pre-fabricated heatable media line 1, in which three heating element portions 50, 51, 58 are provided. The heating element portion 51 extends, as in FIG. 3, along the pipe-type media line 2, over the transition region 20, onto the first line connector 3 and at its other end over the second line connector 4. On the latter it can be connected to the heating element portion 50, or to electrical supply lines 6, 7, as shown in FIG. 3 above. The heating element portion 50 extends along the pipe-type media line 2 and over the two transition regions 20, 21. The third heating element portion 58 is arranged on the first line connector 3. At its ends 580, 581 it can be short-circuited to the other two heating element portions 50, 51 at their ends 53, 54, or the ends 580, 581, 53, 54 can be connected to electrical supply lines 6, 7.

[0058] The embodiment variant of the pre-fabricated heatable media line 1 shown in FIG. 10 is a variant of the embodiment shown in FIG. 4. In contrast to the latter, however, the heating element portion 50 does not extend onto the second line connector 4. Rather, the two line connectors 3, 4 are essentially unheated, since the two heating element portions 50, 51, although they extend over the transition regions 20, 21, only extend in a short section onto the two line connectors 3, 4. Their ends 53, 54 and 55, 56 can once again be short-circuited or connected to electrical supply lines 6, 7, to enable connection to an electrical power supply (not shown). Shown with dashed lines in FIG. 10 is the variant also shown in FIG. 4, in which the two heating element portions 50, 51 are fixedly connected together at the connection point 57 located on the pipe-type media line 2; thus, the first line connector 3 is unheated. The variants shown in FIG. 10 can be provided, in particular, when the entire pre-fabricated heatable media line 1 is arranged in a hot zone, in which no heating of the line connectors 3, 4 is required.

[0059] The embodiment variant of the pre-fabricated heatable media line 1 shown in FIG. 11 comprises three heating element portions 50, 51, 59, wherein the heating element portion 59 is arranged on the second line connector 4, while the two heating element portions 50, 51 extend along the pipe-type media line 2 and over the two transition regions 20, 21. As in the case of the embodiment in FIG. 4, the two heating element portions 50, 51 are fixedly connected together at the connection or crimping point 57 on the first line connector 3, or on the pipe-type media line 2. The ends 56 and 590, or 55 and 591, of the respective heating element portions 51, 59 and 50, 59 can once again be short-circuited or connected to electrical supply lines 6, 7 for purposes of connection to an electrical power supply (not shown).

[0060] In the embodiment variant of the pre-fabricated heatable media line 1 shown in FIG. 12, just two heating element portions 50, 51 are provided, wherein the heating element portion 50 is double-laid, and extends from the second line connector 4, over the transition region 21, the pipe-type media line 2 and the transition region 20 onto a short section of the first line connector 3, and from there extends back across the transition region 20, the pipe-type media line 2 and the transition region 21 onto the second line connector 4. The heating element portion 51 is arranged only on the second line connector 4. At the ends 53, 54 and 55, 56 arranged on the second line connector 4, the heating element portions 50, 51 can be connected together, that is to say, short-circuited, or once again can be connected to electrical supply lines 6, 7, in order to enable a connection to an electrical power supply (not shown). Dashed lines in FIG. 12 show a variant in which the heating element portion 50 does not extend into the transition region 20, or onto the first line connector 3. Here the first line connector 3 and the transition region 20 to the latter remain unheated. In both variants, the first line connector 3 can once again be arranged in a hot zone of a vehicle, while the second line connector 4 is heated and can therefore be arranged in a cold zone.

[0061] FIGS. 7 and 8 show longitudinal cross-sectional views in the region of a line wall 22 of the pipe-type media line 2, wherein on the outer surface of the line wall 22 in each case one turn of the pre-fabricated heating element 5, or a heating element portion of the latter, is arranged, and is attached by a fixing tape 23, such as a fabric-, adhesive- or fabric adhesive tape, or film element. The difference between FIGS. 7 and 8 is simply that the two pre-fabricated heating elements 5 shown in these figures have a different outer diameter d.sub.5. The pre-fabricated heating element 5 or heating element portion shown in FIG. 7 has a smaller outer diameter d.sub.5a than the pre-fabricated heating element 5 or heating element portion with an outer diameter d.sub.5b shown in FIG. 8. A better heat input is provided with the pre-fabricated heating element 5 shown in FIG. 7 with a smaller outer diameter d.sub.5a and a small amount of scatter in the cross-sectional area of the pre-fabricated heating element 5, or of its heating element portions, is possible. This can also be found from the cross-sectional view through an external rib structure, e.g. of the first or second line connector 3, 4, which is shown in FIG. 9. The pre-fabricated heating element 5 or its heating element portion is located in a groove 30 between two ribs 31, 32 of the first line connector 3. An optimal outer diameter d.sub.5 of the pre-fabricated heating element 5, or a heating element portion of the latter, leads to an optimal placement in the groove 30 and thus to particularly good heat transfer.

[0062] FIG. 15 shows the pipe-type media line 2, with two heating element portions 50, 51 wound around the latter. The two heating element portions 50, 51 alternate with each other, as can be seen in the side view of the media line 2 in FIG. 15. As can be seen in FIG. 16, the fixing tape can be designed as at least one film element 123 for purposes of a fixation of the two heating element portions 50, 51 onto the outer surface of the media line 2. This is shown dashed with overlapping turns in FIG. 16. In the embodiment variant shown in FIG. 16, it is wound around the two heating element portions 50, 51, in the opposite direction to the latter, and is also wound around the media line 2. For purposes of fixation, it is sufficient to provide just a section-by-section winding with the at least one film element 123. The latter can also be oriented with the same direction of winding as the heating element portions 50, 51. By heating the media line with the heating element portions 50, 51 arranged on the latter, and the at least one film element 123, the latter relaxes and shrinks, so that it is applied particularly tightly onto the two heating element portions 50, 51 and the outer surface of the media line 2. By this means, a particularly good fixation and tight placement of the heating element portions on the media line is possible, so that a particularly good heating of the media line 2 by the two heating element portions 50, 51 is enabled. When winding onto the media line 2 with the heating element portions 50, 51 or the at least one heating element 5, the at least one film element 123 is advantageously stretched, and/or overextended, and/or plastically deformed, in order to achieve a particularly good placement on the media line and the heating element portions or the heating elements.

[0063] The following tables show possible materials for the twisted individual wires of the heating element portions 50, 51 of the pre-fabricated heating elements 5, which are shown in the embodiment variants shown in FIGS. 1 to 6, and 10 to 12, 15, 16. When twisting seven individual wires around a high tensile strength support element 150, as indicated in FIGS. 13 and 14, the following materials listed in Table 1 can be used, for example, for the individual wires. In Table 1 five different examples 1 to 5 are reproduced in rows for different resistances per unit length R that can be achieved with the combinations of individual wires made from the respectively cited materials. Here one of the individual wires can be the high tensile strength support element, for example wire 7=high tensile strength support element 150.

TABLE-US-00001 TABLE 1 Wire 1 Wire 2 Wire 3 Wire 4 Wire 5 Wire 6 Wire 7 R [/m] Material Material Material Material Material Material Material 1 0.097 Cu Cu Cu Cu Cu CuNi1 CuNi1 2 0.119 Cu Cu Cu CuNi1 CuNi1 CuNi1 CuNi6 3 0.436 CuNi2 CuNi2 CuNi6 CuNi6 CuNi6 CuNi10 CuNi10 4 2.658 CuNi30Mn CuNi44 CuNi44 CuNi44 CuNi44 CuNi44 NiCr3020 5 4.651 CuNi44 NiCr3020 NiCr3020 NiCr3020 NiCr3020 NiCr3020 NiCr3020

[0064] Table 2 below lists examples of materials of the individual wires of a heating element portion, once again with seven twisted individual wires for eight examples 1 to 8 of different resistances per unit length R that can be achieved with the combinations of individual wires made from the respectively cited materials.

TABLE-US-00002 TABLE 2 Wire 1 Wire 2 Wire 3 Wire 4 Wire 5 Wire 6 Wire 7 R [/m] Material Material Material Material Material Material Material 1 0.131 Cu Cu Cu CuNi1 CuNi2 CuNi2 CuNi2 2 0.145 CuNi1 CuNi1 CuNi1 CuNi1 CuNi1 CuNi1 CuNi6 3 0.177 CuNi1 CuNi1 CuNit CuNi1 CuNi2 CuNi2 CuNi15 4 0.198 CuNi1 CuNi1 CuNi1 CuNi1 CuNi6 CuNi10 CuNi10 5 0.218 CuNi1 CuNi1 CuNi2 CuNi2 CuNi2 CuNi2 CuNi10 6 0.242 CuNi1 CuNi2 CuNi2 CuNi2 CuNi2 CuNi2 CuNi6 7 0.326 CuNi2 CuNi2 CuNi2 CuNi2 CuNi2 CuNi10 CuNi15 8 0.397 CuNi2 CuNi2 CuNi2 CuNi6 CuNi6 CuNi10 CuNi15

[0065] Table 3 below shows possible materials for the individual wires of a heating element portion with nineteen twisted individual wires for five examples 1 to 5 of different resistances per unit length R that can be achieved with the combinations of individual wires made from the respectively cited materials.

TABLE-US-00003 TABLE 3 Example 1 Example 2 Example 3 Example 4 Example 5 R [/m] 0.131 0.145 0.162 0.177 0.198 Wire 1 Material Cu CuNi1 Cu CuNi1 CuNi1 Wire 2 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 3 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 4 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 5 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 6 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 7 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 8 Material CuNi1 CuNi1 CuNi1 CuNi1 CuNi1 Wire 9 Material CuNi1 CuNi1 CuNi1 CuNi1 CuNi1 Wire 10 Material CuNi1 CuNi1 CuNi1 CuNi1 CuNi1 Wire 11 Material CuNi1 CuNi1 CuNi1 CuNi2 CuNi1 Wire 12 Material CuNi1 CuNi1 CuNi1 CuNi2 CuNi2 Wire 13 Material CuNi1 CuNi1 CuNi2 CuNi2 CuNi10 Wire 14 Material CuNi22 CuNi1 CuNi2 CuNi2 CuNi10 Wire 15 Material CuNi2 CuNi1 CuNi2 CuNi2 CuNi10 Wire 16 Material CuNi2 CuNi1 CuNi2 CuNi2 CuNi10 Wire 17 Material CuNi2 CuNi2 CuNi2 CuNi2 CuNi10 Wire 18 Material CuNi2 CuNi2 CuNi6 CuNi2 CuNi10 Wire 19 Material CuNi6 CuNi6 CuNi6 CuNi10 CuNi15

[0066] Table 4 below shows possible materials for the individual wires of a heating element portion with thirty-seven twisted individual wires for five examples 1 to 5 of different resistances per unit length R that can be achieved with the combinations of individual wires made from the respectively cited materials.

TABLE-US-00004 TABLE 4 Example 1 Example 2 Example 3 Example 4 Example 5 R [/m] 0.131 0.145 0.162 0.177 0.198 Wire 1 Material Cu Cu Cu CuNi1 CuNi1 Wire 2 Material Cu CuNi1 Cu CuNi1 CuNi1 Wire 3 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 4 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 5 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 6 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 7 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 8 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 9 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 10 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 11 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 12 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 13 Material Cu CuNi1 CuNi1 CuNi1 CuNi1 Wire 14 Material Cu CuNi1 CuNi1 CuNI1 CuNi1 Wire 15 Material CuNi1 CuNi1 CuNi1 CuNi1 CuNi2 Wire 16 Material CuNi1 CuNi1 CuNi1 CuNi1 CuNi2 Wire 17 Material CuNi1 CuNi1 CuNi1 CuNi1 CuNi2 Wire 18 Material CuNi1 CuNI1 CuNi1 CuNi1 CuNi2 Wire 19 Material CuNi1 CuNi1 CuNi1 CuNi2 CuNi2 Wire 20 Material CuNi1 CuNi1 CuNi1 CuNi2 CuNi2 Wire 21 Material CuNi1 CuNi1 CuNi1 CuNi2 CuNi2 Wire 22 Material CuNi1 CuNi1 CuNi1 CuNi2 CuNi2 Wire 23 Material CuNi1 CuNi1 CuNi1 CuNi2 CuNi2 Wire 24 Material CuNi1 CuNi1 CuNi1 CuNi2 CuNi2 Wire 25 Material CuNi1 CuNi1 CuNi1 CuNi2 CuNi2 Wire 26 Material CuNi1 CuNi1 CuNi2 CuNi2 CuNi2 Wire 27 Material CuNi2 CuNi1 CuNi2 CuNi2 CuNi2 Wire 28 Material CuNi2 CuNi1 CuNi2 CuNi2 CuNi2 Wire 29 Material CuNi2 CuNi1 CuNi2 CuNi2 CuNi2 Wire 30 Material CuNi2 CuNi1 CuNi2 CuNi2 CuNi2 Wire 31 Material CuNi2 CuNi2 CuNi2 CuNi2 CuNi2 Wire 32 Material CuNi2 CuNi2 CuNi6 CuNi2 CuNi2 Wire 33 Material CuNi2 CuNi2 CuNi6 CuNi2 CuNi2 Wire 34 Material CuNi6 CuNi2 CuNi6 CuNi2 CuNi2 Wire 35 Material CuNi6 CuNi2 CuNi10 CuNi2 CuNi6 Wire 36 Material CuNi6 CuNi2 CuNi10 CuNi2 CuNi6 Wire 37 Material CuNi6 CuNi6 CuNi10 CuNi2 CuNi10

[0067] A plastic profile or, for example, an individual wire can be used as a high tensile strength member 150, or a high tensile strength core, of the respective heating element portion, so that in the latter case the material of the high tensile strength support element corresponds to one of the materials from the above Tables 1 to 4. In the latter case, the cross-section through the heating element portion would differ from that shown in FIG. 14, in that one of the individual wires is arranged in the interior as a high tensile strength support element, and the other six individual wires are twisted around the latter. The individual wires can all have the same outer diameter.

[0068] In the following, a design example for a pre-fabricated heatable media line with two line connectors 3, 4 is described, wherein the structure is a so-called two-wire strand design (as can be seen in FIGS. 1 to 4, 10 and 12), that is to say, in which two heating element portions 50, 51 are provided, wherein in each case a heating element portion 50, 51, which extends along the pipe-type media line 2, is also used for one of the two line connectors 3, 4, as shown in FIGS. 1 and 3. Table 5 below contains specifications of the pre-fabricated media line, wherein the specifications of two different variants I and II are compared with each other.

TABLE-US-00005 TABLE 5 Media line with two line connectors, Two-wire strand design I II Required power output 1.2 W 1.2 W line connector 3 Exemplary fixed heating element 400.0 mm 400 mm length, line connector 3, defined by the tracking on the latter Required power output 1.8 W 1.8 W line connector 4 Exemplary fixed heating element 400 mm 400 mm length, line connector 4, defined by the tracking on the latter Required power output on the media 12.5 W/M 12.5 W/M line (pipe line) Exemplary pipe diameter of the media 4.05 mm 4.05 mm line Exemplary nominal operating voltage, 13.5 V 13.5 V voltage Exemplary media line 4.700 mm 4.700 mm length Basic line length for 1.000 mm 1.000 mm one metre

[0069] Table 5a below cites the diameter of an inventive mixed stranded wire and its exemplary preferred cross-sectional area.

TABLE-US-00006 TABLE 5a Diameter of the mixed stranded wires 1.10 mm Preferred reduced cross-sectional area 0.20 mm.sup.2

[0070] From Tables 5 and 5a ensue the following values reproduced in Tables 6 to 6f and subsequently explained in more detail, wherein the values contained in Table 6 apply to the Variants I and II from Tables 5 and 5a, the values contained in Table 6a apply to Variant 1, the values contained in Table 6b apply to Variant II, the values contained in Table 6c apply to Variant 1, the values contained in Table 6d apply to Variant II, the values contained in Table 6e apply to Variant I, and the values contained in Table 6f apply to Variant II.

TABLE-US-00007 TABLE 6 Required heating element power 3 W/m Results from power on line connector output for line connector 3 3 and length of line connector 3 Required heating element power 4.5 W/m Results from power on line connector output for line connector 4 4 and length of line connector 4 Necessary quantity per heating 1.67 M Results from the requirement media element on the media line line power output/power output of the two stranded wires or heating element portions Pitch of the heating elements on 12 mm Results from the length 1,000 m, the the pipe line/media line necessary heating element length on a metre media line and the diameters for media line and heating element Total quantity of the first heating 8,233 mm Quantity of the heating element for the element to be used on the line media line length + length at QC1 connector 3 (QC1) Total quantity of the first heating 8,233 mm Quantity of the heating element for the element to be used on the line media line length + length at QC2 connector 4 (QC2) Power output to be generated 25 Length of the first heating element x with the first heating element power on this heating element Power output to be generated 37 Length of the second heating element with the second heating element x power on this heating element Total power output generated 61.8 W Sum of the two Heating element power outputs Required current 4.57 A Power output/voltage Resistance to be generated by 1.18 Ohm I = P/I.sup.2 first heating element Resistance to be generated by 1.77 Ohm I = P/I.sup.2 second heating element Total resistance 2.95 Ohm Media line resistance generated by both heating elements

TABLE-US-00008 TABLE 6a Required specific 0.143 Ohm/m Results from the resistance of the heating element first heating element and the resistance 1 quantity to be used Required specific 0.215 Ohm/m Results from the resistance of the heating element second heating element and the resistance 2 quantity to be used

TABLE-US-00009 TABLE 6b Required specific 0.215 Ohm/m Results from the resistance of the heating element first heating element and the resistance 1 quantity to be used Required specific 0.358 Ohm/m Results from the resistance of the heating element second heating element and the resistance 2 quantity to be used

TABLE-US-00010 TABLE 6c Possible cross-sectional area for 0.119 mm.sup.2 with Cu Made from only first heating element one material Possible cross-sectional area for 0.174 mm.sup.2 with CuNi 1 Made from only first heating element one material Possible cross-sectional area for 0.349 mm.sup.2 with CuNi 2 Made from only first heating element one material Possible cross-sectional area for 0.116 mm.sup.2 with CuNi 1 Made from only second heating element one material Possible cross-sectional area for 0.232 mm.sup.2 with CuNi 2 Made from only second heating element one material Possible cross-sectional area for 0.465 mm.sup.2 with CuNi 6 Made from only second heating element one material

TABLE-US-00011 TABLE 6d Possible cross-sectional 0.116 mm.sup.2 with CuNi 1 Made from only one area for first heating material element Possible cross-sectional 0.232 mm.sup.2 with CuNi 2 Made from only one area for first heating material element Possible cross-sectional 0.465 mm.sup.2 with CuNi 6 Made from only one area for first heating material element Possible cross-sectional 0.139 mm.sup.2 with CuNi 2 Made from only one area for second heating material element Possible cross-sectional 0.279 mm.sup.2 with CuNi 6 Made from only one area for second heating material element Possible cross-sectional 0.418 mm.sup.2 with CuNi 10 Made from only one area for second heating material element

TABLE-US-00012 TABLE 6e Resistance of the first heating 0.145 Ohm/m with 6xCuNi 1 element portion (stranded 1xCuNi 6 wire) with 0.20 mm.sup.2 Resistance of the second 0.218 Ohm/m with 4xCuNi 2 heating element portion (stranded 2xCuNi 1 wire) with 0.20 mm.sup.2 1xCuNi 10

TABLE-US-00013 TABLE 6f Resistance of the first heating 0.218 Ohm/m with 4xCuNi 2 element portion (stranded 2xCuNi 1 wire) with 0.20 mm.sup.2 1xCuNi 10 Resistance of the second 0.358 Ohm/m with 4xCuNi 2 heating element portion 1xCuNi 6 (stranded wire) with 0.20 mm.sup.2 1xCuNi 10 1xCuNi 15

[0071] Table 7 below gives the respective specific resistances of the materials cited in the above tables:

TABLE-US-00014 TABLE 7 Materials/ Specific resistance alloys Material [Ohm * mm.sup.2/m] Cu 0.017 CuNi 1 0.025 CuNi 2 0.050 CuNi6 0.100 CuNi 10 0.150 CuNi 15 0.210 CuNi 23 0.300 CuNi 30 0.400 CuNi 44 0.490 NiCr3020 1.040

[0072] The power P.sub.3 required on the first line connector 3 is e.g. P.sub.3=1.2 W. The exemplary fixed heating element portion length l.sub.3 on the line connector 3, which is predetermined by the tracking in the rib structure on its outer surface, is l.sub.3=400.00 mm. The power P.sub.4 required on the second line connector 4 is e.g. P.sub.4=1.8 W. The exemplary fixed heating element portion length l.sub.4 on the line connector 4, which is predetermined by the tracking in the rib structure on its outer surface, is also l.sub.4=400.00 mm. The power P.sub.2 required on the pipe-type media line 2 is e.g. P.sub.2=12.5 W/m, the media line diameter d.sub.2 is e.g. d.sub.2=4.05 mm. The exemplary nominal operating voltage U is U=13.5 V. The line length L is e.g. L=4,700 mm, the basic line length for one meter 1,000 mm.

[0073] The diameter d.sub.50,51 of the heating element portions 50, 51 designed as mixed wire strands should be d.sub.50,51=1.10 mm (=stranded wire diameter including insulation), and the preferred cross-sectional area A.sub.50,51 of the latter is A.sub.50,51=0.20 mm.sup.2. The latter is the cross-sectional area of the metallic parts of the individual wires, that is to say, without their insulation sheathing.

[0074] From this, the (partial) heating element power P.sub.50 for the first line connector 3 results from the power P.sub.3 on the first line connector 3 to the length l.sub.3 of the heating element portion 50 on the first line connector as P.sub.50=3 W/m.

[0075] The (partial) heating element power P.sub.51 for the second line connector 4 results from the power P.sub.4 on the second line connector 4 relative to the length l.sub.4 of the heating element portion on the second line connector 4 as P.sub.51=4.5 W/m. The necessary length l per heating element portion on the media line 2 results from the ratio of the line power P.sub.2 to the sum of the powers P.sub.50, P.sub.51 of the two heating element portions 50, 51 as l=1.67 m. The required pitch of the heating element portions 50, 51 on the pipe-type media line 2 ensues from the basic line length of 1,000 mm, the necessary length l per heating element portion on a metre line and the diameters d.sub.2, d.sub.50,51 of the pipe-type media line 2 and the heating element portions 50, 51 designed as mixed wire strands as s=12 mm. The total length to be used L.sub.50ges on heating element portion 50 (on the line connector 3) results from the length l on heating element portion 50 for the wrapping of the pipe-type media line 2, the length L of the line and the length l.sub.3 on the line connector 3 as L.sub.50ges=8,233 mm. The total length to be used L.sub.51ges on heating element portion 51 (on the line connector 4) results from the length l on heating element portion 51 for the wrapping of the pipe-type media line 2, the length L of the line and the length l.sub.4 on the line connector 4 as L.sub.51ges=8,233 mm.

[0076] The power P.sub.50ges to be generated with the heating element portion 50 results from the length L.sub.50ges on the heating element portion 50, multiplied by the power P.sub.50 on heating element portion 50, as P.sub.50ges=25 W. The power P.sub.51ges to be generated with the heating element portion 51 results from the length L.sub.51ges on the heating element portion 51, multiplied by the power P.sub.51 on the heating element portion 51, as P.sub.51ges=37 W. The total power of the two heating element portions 50, 51 results from the sum of the two powers P.sub.50ges and P.sub.51ges as P.sub.50,51ges=61.8 W. The required current I is thus I=4.57 A. From this, the resistance R.sub.50 to be generated by the heating element portion 50 is calculated from the power P.sub.50ges relative to the square of the current I as R.sub.50=1.18; the resistance R.sub.51 to be generated by the heating element portion 51 is calculated from the power P.sub.51ges relative to the square of the current I as R.sub.51=1.77. The sum of the resistances R.sub.50 and R.sub.51 is thus R.sub.50,51=2.95 0. The required resistance per unit length R.sub.L50 of the heating element portion 50 results from the resistance R.sub.50 and the heating element portion length to be used L.sub.50ges as R.sub.L50=0.143 /m. The required resistance per unit length R.sub.L51 of the heating element portion 51 results from the resistance R.sub.51 and the heating element portion length to be used L.sub.51ges as R.sub.L51=0.215 /m.

[0077] This would result in a possible cross-sectional area A50 for the heating element portion 50 of A.sub.50=0.119 mm.sup.2, if this were to consist of only one material, here Cu, or A.sub.50=0.174 mm.sup.2, if this were to consist of only one material, here CuNi1, or A.sub.50=0.349 mm.sup.2, if this were to consist of only one material, here CuNi2. This would result in a possible cross-sectional area A.sub.51 for the heating element portion 51 of A.sub.51=0.116 mm.sup.2, if this were to consist of only one material, here CuNi1, or A.sub.51=0.232 mm.sup.2, if this were to consist of only one material, here CuNi2, or A.sub.51=0.465 mm.sup.2, if this were to consist of only one material, here CuNi6. The first and second design for the first heating element portion 50 would thus be too small, and the third would mean too high a material consumption. For the second heating element portion 51, the first design would be too small, the two last-cited designs, or at least the latter design, would lead to too high a material consumption and thus to increased costs. In addition, the outer diameter including insulation would possibly be too large, so that insertion into a tight protective covering, such as a narrow insulation tube, e.g. a corrugated tube, would not be possible, and therefore a larger protective covering diameter or corrugated tube diameter would possibly have to be used.

[0078] The two heating element portions 50, 51 are therefore designed in accordance with the invention as mixed wire strands. Here, the resistance per unit length R.sub.50/20 of the heating element portion 50 with a cross-sectional area of A.sub.50=0.20 mm.sup.2 is, for example, R.sub.50/20=0.145 /m when using seven twisted individual wires, of which six consist of CuNi1 and one consists of CuNi6. The resistance per unit length R.sub.51/20 of the heating element portion 51, designed as a mixed wire strand, with a cross-sectional area of A.sub.51=0.20 mm.sup.2 is, for example, R.sub.51/20=0.218 /m when using seven twisted individual wires, of which four consist of CuNi2, two consist of CuNi1, and one consists of CuNi10. Needless to say, other material combinations of the individual wires are possible for purposes of achieving a heating element portion with a desired specific resistance, with a predetermined cross-sectional area of the heating element portion. In particular, copper-zinc alloys or copper-tin alloys can be used here for one or more of the individual wires. In the case of seven individual wires, each with an outer diameter of the metallic part, that is to say, without insulation sheathing, of 0.19 mm, there ensues a cross-sectional area of 0.19.sup.2*pi/4=0.028 mm.sup.2 per individual wire, that is to say, a total cross-sectional area of the mixed wire strand of 0.028 mm.sup.27=0.2 mm.sup.2. Thus, with a predefined or predefinable cross-sectional area or cross-section of the heating element portion of, for example, 0.2 mm.sup.2 of the two heating element portions to be connected, it is possible to select, or configure, a desired resistance by a suitable selection of the individual wires of the mixture of individual wires.

[0079] By using a mixed wire strand as a heating element portion and the appropriate connection in series of at least two heating element portions to form a pre-fabricated heating element, it is thus possible to adjust the total resistance of the latter such that the heat output over the extent of the pre-fabricated heatable media line can be optimally adjusted for a specific application, thus, in particular, in the zones in which only a small heat output is required, only such is provided, whereas in the zones where a high heat output is required to thaw out a frozen medium in the pre-fabricated heatable media line, or to prevent a medium from freezing, a suitably high heat output is provided.

[0080] In addition to the embodiment variants of pre-fabricated heatable media lines and pre-fabricated heating elements cited above and shown in the figures, numerous other combinations can be provided, also any combinations of the features cited, wherein at least one pipe-type and/or hose-type media line, at least one line connector arranged at the end of the latter, and at least one pre-fabricated heating element are provided, which comprises at least two heating element portions, which are connected in at least one circuit, wherein at least one of the heating element portions is formed as a mixed wire, which has a number of twisted individual wires, consisting of at least two different materials.

LIST OF REFERENCE SYMBOLS

[0081] 1 Pre-fabricated heatable media line [0082] 2 Pipe-type media line [0083] 3 Line connector [0084] 4 Line connector [0085] 5 Pre-fabricated heating element [0086] 6 Electrical supply line [0087] 7 Electrical supply line [0088] 20 Transition region/area [0089] 21 Transition region/area [0090] 22 Line wall [0091] 23 Fixing tape [0092] 30 Groove [0093] 31 Rib [0094] 32 Rib [0095] 50 Heating element portion 51 Heating element portion [0096] 52 Connection point/crimping point [0097] 53 End of 50 [0098] 54 End of 51 [0099] 55 End of 5056 End of 51 [0100] 57 Connection point/crimping point [0101] 58 Heating element portion [0102] 59 Heating element portion [0103] 123 Film element [0104] 150 High tensile strength support element/high tensile strength core [0105] 151 Individual wire [0106] 152 Individual wire [0107] 153 Individual wire [0108] 154 Individual wire [0109] 155 Individual wire [0110] 156 Individual wire [0111] 157 Individual wire [0112] 158 Protective sheath [0113] 580 End of 58 [0114] 581 End of 58 [0115] 590 End of 59 [0116] 591 End of 59 [0117] l.sub.s Lay length [0118] d.sub.5 Outer diameter of 5 [0119] d.sub.5a Outer diameter of 5 [0120] d.sub.5b Outer diameter of 5