Multi-layer heating tape and fluid flow tube comprising such tape

Abstract

The present invention relates to a multilayer heating band (3) comprising a plurality of stacked layers, the plurality of stacked layers comprising at least: - a first dielectric layer (52), - a heating film (6) above the first dielectric layer (52), - a second dielectric layer on the heating film (6), - a shielding layer on the second dielectric layer, and - a third dielectric layer on the shielding layer, wherein the heating film comprises two conductive strips (64, 66), and an element (62) having a PTC effect extends between the two conductive strips, the band being in the form of several multilayer segments (32), each multilayer segment comprising a middle portion (322) and two ends (324, 326), the middle portion extending between the two ends. Furthermore, the band can be cut to a desired length at the joints (320) between the multilayer segments.

Description

Technical Field

[0001] This invention relates to the field of heating systems for fluid flow tubes, particularly for use in the aerospace industry (e.g., aircraft).

[0002] More specifically, the present invention relates to a multi-layer heating belt, particularly for use in fluid flow tubes, and to a fluid flow tube comprising such a multi-layer heating belt, particularly for use in the aerospace industry. The invention also relates to a wastewater discharge circuit for aircraft comprising such a fluid flow tube, and a method for manufacturing such a fluid flow tube. Background Technology

[0003] Prior art includes, in particular, documents BE 890145 A, US 2023 / 077788 A1, US 2016223116 A1, US2022 / 411076 A2 and CN 2571103Y.

[0004] Heating systems are often essential for the proper functioning of certain components, such as fluid flow lines, particularly in the aerospace industry. In addition to temperature regulation, heating systems especially prevent the fluid circulating in the fluid flow lines from freezing.

[0005] For example, fluid flow pipes in the aerospace industry (e.g., aircraft) can be pipes for wastewater discharge, pipes for supplying drinking water, coolant, or any other liquid. Therefore, these pipes can be heated, particularly to maintain temperature and / or prevent the fluids (especially water) inside these pipes from freezing.

[0006] As is known in the prior art, such heating systems may include multiple stacked layers to form a multilayer heating belt. One possible solution for this type of belt includes, for example, the following stacked layers: - Adhesive layer, - The first dielectric layer located above the adhesive layer. - A heating film located above the first dielectric layer. - The second dielectric layer on the heating film, - The shielding layer on the second dielectric layer, and - The third dielectric layer on the shielding layer.

[0007] Therefore, multilayer heating tapes can be glued along the tube via an adhesive layer, typically onto a single longitudinal section and / or one side of the tube. Such tapes can also be connected to an external power source via wire-type electrical connectors, particularly those connecting to the dielectric and shielding layers. This tape construction results in a small contact area with the tube, thus preventing uniform, regular, and temperature-neutral heating of the tube.

[0008] refer toFigure 1 In the prior art, it is also known to manufacture a heating cable 300 comprising two copper conductors and a heating element with a positive temperature coefficient (PTC) effect located between the two conductors. The heating cable 300 is attached to one side of the pipe 1 by an adhesive A. The adhesive A is wrapped around the pipe 1 and the heating cable 300. However, such a heating cable 300 is very thick, rigid, and difficult to integrate around the pipe, especially in wastewater discharge loops.

[0009] Furthermore, multi-layer heating tapes are often too large, allowing them to be glued along the entire length of the tube. This makes the tape inflexible, heavy, and cumbersome, especially for fluid flow tubes.

[0010] In this context, it is of interest to propose a new solution for a reliable, flexible, modular, and compact multilayer heating belt for fluid flow tubes. Summary of the Invention

[0011] This invention provides a simple, effective, and economical solution to overcome at least some of the aforementioned disadvantages.

[0012] Therefore, the present invention relates to a multilayer heating belt, particularly for use in fluid flow pipes, the belt having an elongated shape and comprising a plurality of stacked layers, the plurality of stacked layers comprising at least: - First dielectric layer, - A heating film located above the first dielectric layer. - The second dielectric layer on the heating film, - The shielding layer on the second dielectric layer, and - The third dielectric layer on the shielding layer.

[0013] According to the present invention, the heating film includes two conductive strips extending along a strip, and an element having a PTC (positive temperature coefficient) effect extends between the two conductive strips.

[0014] According to the present invention, the strip is in the form of several multi-layered segments, each of which has an elongated shape and is connected end to end. These multi-layered segments are identical and each multi-layered segment includes: a) An intermediate portion extending over at least 50% of the length of the multi-layered segment and comprising: - First dielectric layer, - A heating film located above the first dielectric layer, the heating film comprising strip portions and portions of elements having a PTC effect. - The second dielectric layer on the heating film, - A shielding layer on the second dielectric layer, the shielding layer comprising a shielding mesh, and - The third dielectric layer on the shielding layer, and b) Two ends, with a middle portion extending between these two ends, the ends being identical and each end comprising: - First dielectric layer, - A heating film located above the first dielectric layer, the heating film comprising strip portions but without PTC elements. - The second dielectric layer on the heating film, - A shielding layer on the second dielectric layer, the shielding layer including conductive tracks connected to the shielding mesh in the middle portion, and - The third dielectric layer on the shielding layer.

[0015] According to the present invention, the strip can be cut to the desired length at the joint between multiple segments.

[0016] Therefore, the multi-layer heating belt according to the present invention achieves the above-mentioned objective.

[0017] In particular, the construction of the heating film (especially the PTC-effect element sandwiched between two conductive strips) allows the fluid to be heated, thawed, and maintained at a uniform temperature throughout the tube, while preventing overheating in the event of any malfunction, thus protecting the user (especially in the case of a short circuit).

[0018] Furthermore, the belt consists of several multi-layered segments connected end-to-end. Each multi-layered segment includes a specific arrangement of two ends, with a middle section extending between these two ends. The middle section, including a heating element, effectively heats the tube. Each end without a heating element connects to one of the other two ends of the adjacent multi-layered segment of the belt (and / or, when that end forms one of the free ends of the belt, connects to an electrical connector). Thus, the interface between the ends of adjacent multi-layered segments forms a preferred and secure engagement zone for cutting and adjusting the belt length relative to the actual dimensions of the tube. In this way, the belt can be manufactured according to functional requirements (i.e., according to the length of the tube to be heated) and assembled onto the tube.

[0019] Therefore, the advantages of this invention are that it provides a simple multilayer heating band design, offers high reliability, and suffers almost no loss in terms of cost and volume, especially in fluid flow tubes.

[0020] The multilayer heating belt according to the present invention may include one or more of the following features, which may be considered independently or in combination with each other: - At least a portion of these dielectric layers are made of polyimide; These bars are made of copper; - The shielding layer, especially the shielding mesh and conductive tracks of each multi-layer segment, is made of copper; - The thickness of each layer or film is between 10 μm and 100 μm, and the total thickness of the strip is between 100 μm and 900 μm; - The width of the strip is between 10 mm and 100 mm, preferably between 30 mm and 50 mm; - Each of these strips has an additional thickness at both ends; - One of the free ends of the strip is connected to an electrical connector, which includes three terminals: a first terminal, a second terminal, and a third terminal. The first terminal is electrically connected to one of the strips, the second terminal is electrically connected to the other of the strips, and the third terminal is electrically connected to the shielding layer. - The free end of the belt is formed by the end of one of the multi-layered segments of the belt, a first terminal is electrically connected to one strip of the end, a second terminal is electrically connected to another strip of the end, and a third terminal is electrically connected to the conductive track of the end; - The terminals of the electrical connector are connected to conductors, the ends of which are fixed to the free end of the strip; - The strip also includes at least one adhesive layer located within the stacked layers, wherein the middle portion and the ends include at least one adhesive layer; - The first dielectric layer is located above the adhesive layer; - Among the first dielectric layer, heating film, second dielectric layer, shielding layer and third dielectric layer, the adhesive layer is located between the two stacked layers of the strip.

[0021] The present invention also relates to a fluid flow tube, particularly for use in the aerospace industry, comprising a tubular body and a multi-layer heating band according to one of the features of the invention, the multi-layer heating band being attached to and assembled on the tubular body.

[0022] The fluid flow pipe according to the present invention may include one or more of the following features, which may be considered independently or in combination with each other: - Multi-layer heating bands are spirally wound around the tubular body; - The belt is assembled by gluing it to the tubular body using its adhesive layer, or by welding it to the tubular body. - The tubular body may include at least one straight and / or angled tubular portion; - The tubular body can be made of plastic, polymer, thermoplastic (e.g., polyetheretherketone, PEEK), etc. - The tubular body can be made of metal; - The maximum diameter of the tubular body is approximately between 0.5 cm and 8 cm, preferably between 1 cm and 5 cm.

[0023] The present invention also relates to a wastewater discharge circuit for an aircraft, the wastewater discharge circuit including a fluid flow pipe according to one of the features of the present invention.

[0024] The present invention also relates to a method for manufacturing a fluid flow tube according to one of the features of the present invention, the method comprising the following steps: (i) Cut a strip according to the length of the tube to be heated, the cut being made at the joint between two consecutive segments. (iii) Assemble the belt around the tubular body, preferably in a spiral manner.

[0025] Prior to step (iii) of assembling the tape, the method may include step (ii) of attaching at least one electrical connector to the tape.

[0026] Assembly step (iii) can be performed by gluing or welding. Welding is preferably performed by spot welding. Attached Figure Description

[0027] The invention will be better understood from the following description by way of non-limiting example and with reference to the accompanying drawings, and other details, features and advantages of the invention will become clearer, as illustrated in the drawings: Figure 1 This is a schematic partial outline view of a prior art heating system, which includes heating cables attached to a tube by an adhesive. Figure 2 This is a schematic three-dimensional partial view, for example, of a wastewater discharge circuit for an aircraft, which includes a fluid flow pipe according to the invention; Figure 3 It includes the multi-layer heating belt according to the present invention. Figure 2 A schematic diagram of an example of a fluid flow tube; Figure 4 It schematically represents Figure 3 A first example of a multilayer heating band with stacked layers; Figure 5 It schematically represents Figure 3 A second example of a multilayer heating band with stacked layers; Figure 6 It schematically represents Figure 3 A third example of a multilayer heating band stacked layer; Figure 7 It schematically represents Figure 3 A fourth example of a multilayer heating band with stacked layers; Figure 8a yes Figure 3 A schematic bottom-view partial view of a single multi-layer segment of a fifth example of a multi-layer heating belt; Figure 8b yes Figure 8a A schematic partial top view of the multi-segment structure; Figure 9 yes Figure 8a A schematic partial bottom view of several segments of the fifth example of a multi-layer heating belt; Figure 10a It is connected to the electrical connector. Figure 9 Another schematic bottom-view partial view of the multi-layer heating belt; Figure 10b It is based on Figure 10a A schematic partial bottom view of another embodiment of a multilayer heating band connected to an electrical connector; Figure 11 yes Figure 9 A schematic top-view partial view of the multi-layer heating belt; Figure 12 This is a block diagram illustrating an example of a method for manufacturing a fluid flow tube according to the present invention.

[0028] Elements that have the same function in different embodiments have the same reference numerals in these figures. Detailed Implementation

[0029] In the following description, the invention is applied in a non-limiting manner to wastewater discharge circuit 10, such as that used in aircraft 100. The invention can also be applied to other fluid discharge circuits, drinking water supply circuits, coolant supply circuits, or any other fluids in aircraft or any other transportation system (e.g., automobiles).

[0030] refer to Figure 2 However, not limited to this, the wastewater discharge circuit 10 may be arranged in the cabin 102 of the aircraft 100. The circuit 10 may include one or more drinking water reservoirs 12 and one or more wastewater reservoirs 14. The circuit 10 may include at least one fluid flow pipe 1. This pipe 1 may be connected to the wastewater reservoir 14 to deliver wastewater to the wastewater reservoir 14. The pipe 1 may be secured to the aircraft structure 100 (e.g., in the cabin 102) by means of, for example, a clamp equipped with a fixing tab.

[0031] The tube 1 may include a tubular body 2 and at least one multi-layer heating belt 3. The tube 1 and belt 3 may be used without limitation in any fluid transport loop or any other transport system in the aircraft 100.

[0032] The tubular body 2 may include at least one straight and / or angled tubular portion. Figure 3 An example of a tube 1 including a straight portion of a tubular body 2 is shown.

[0033] The maximum diameter D2 of the tubular body 2 can be between approximately 0.5 cm and 8 cm, preferably between approximately 1 cm and 5 cm.

[0034] The tubular body 2 may have a first length L2. This first length L2 may approximately correspond to the total length of the tube 1. The first length L2 may be on the order of tens of meters.

[0035] The tubular body 2 may include one or more branched portions (in) Figure 1 (As can be seen in the image). The cross-section of the tubular body 2 between its multiple branch sections can be between 1200 mm and 1600 mm.

[0036] The tubular body 2 can be made of plastic, polymer, thermoplastic (e.g., polyetheretherketone, PEEK), etc. Alternatively, the tubular body can be made of metal.

[0037] refer to Figure 3 However, it is not limited to this; the strip 3 can be attached to and assembled onto the tubular body 2. The strip 3 can be spirally wound onto the tubular body 2. This spiral winding helps to enhance the uniform heating of the entire tube 1.

[0038] In particular, when there are one or more branch sections on pipe 1, one or more strips 3 may be required.

[0039] Therefore, the belt 3 may include several turns 30 forming a helical winding around the tubular body 2. These turns 30 can be arranged according to a predetermined distance d. 30 Separated from each other, this predetermined distance is specifically along the tubular body 2 and measured between two parallel planes separated by a helical turn. This distance d 30 It can be between 5 mm and 25 mm. Preferably, the distance d 30 It can be approximately 15 mm. Distance d 30 The length L2 of the tubular body 2 can be varied and adjusted according to the first length L2 and / or the electrical connector 8 described below.

[0040] The multi-layer heating belt 3 has an elongated shape.

[0041] Strip 3 has multiple stacked layers, which include at least: - Optional adhesive layer 4, - First dielectric layer 52, - The heating film 6 is located above the first dielectric layer 52. - The second dielectric layer 54 on the heating film 6, - Shielding layer 7 on the second dielectric layer 54, and - The third dielectric layer 56 on the shielding layer 7.

[0042] The first dielectric layer 52 may be located above the adhesive layer 4. Among the first dielectric layer 52, heating film 6, second dielectric layer 54, shielding layer 7 and third dielectric layer 56, one of the adhesive layers 42 and 44 may be located between the two stacked layers of the strip 3.

[0043] Figures 4 to 7 Different examples of arrangements with 3 stacked layers are shown in a non-limiting manner. Figures 4 to 7 It is a cross-sectional view along the cut plane of the patch (or in other words, one of the strips) of the element 62 with PTC effect that passes through the heating film 6.

[0044] Figure 4 A first example of strip 3 including the following stacked layers is shown: - First adhesive layer 4, - The first dielectric layer 52 is located above the first adhesive layer 4. - Heating film 6 on the first dielectric layer 52, - The second dielectric layer 54 on the heating film 6, - Shielding layer 7 on the second dielectric layer 54, and - The third dielectric layer 56 on the shielding layer 7.

[0045] Figure 5 A second example of strip 3, including the following stacked layers, is shown: - First dielectric layer 52, - The heating film 6 is located above the first dielectric layer 52. - The second adhesive layer 42 on the heating film 6, - The shielding layer 7 on the heating film 6, and - The third dielectric layer 56 on the shielding layer 7.

[0046] The second dielectric layer 54 and the first adhesive layer 4 are absent in the second example of band 3. Therefore, the second dielectric layer 54 and the first adhesive layer 4 can be optional in band 3.

[0047] Figure 6 A third example of strip 3, including the following stacked layers, is shown: - First adhesive layer 4, - The first dielectric layer 52 is located above the first adhesive layer 4. - The heating film 6 is located above the first dielectric layer 52. - The second adhesive layer 42 on the heating film 6, - Second dielectric layer 54 on second adhesive layer 42 - Shielding layer 7 on the second dielectric layer 54, and - The third dielectric layer 56 on the shielding layer 7.

[0048] Therefore, a third example of the strip includes an additional second adhesive layer 42 sandwiched between the heating film 6 and the second dielectric layer 54. This helps to hold the heating film 6 and the second dielectric layer 54 in place.

[0049] Figure 7 A fourth example of strip 3 is shown, which includes the following stacked layers: - Removable layer 9 - The first adhesive layer 4 on the removable layer 9, - The first dielectric layer 52 is located above the first adhesive layer 4. - The heating film 6 is located above the first dielectric layer 52. - The second adhesive layer 42 on the heating film 6, - Second dielectric layer 54 on second adhesive layer 42 - Shielding layer 7 on the second dielectric layer 54 - The third adhesive layer 44 on the shielding layer 7, and - The third dielectric layer 56 on the third adhesive layer 44.

[0050] Therefore, the fourth example with band 3 includes an additional third adhesive layer 44 sandwiched between the second dielectric layer 54 and the shielding layer 7. This helps to hold the shielding layer 7 and the second dielectric layer 54 in place.

[0051] Advantageously, each of the aforementioned layers 4, 42, 44, 52, 54, 56, and 7 can have a thickness of 10 μm to 100 μm. The heating film 6 can have a thickness of 10 μm to 100 μm.

[0052] The adhesive layer 4 allows the tape 3 to be bonded around the tubular body 2. For example, the adhesive layer 4 can be a pressure-sensitive adhesive (PSA). The adhesive layer 4 (and / or the second adhesive layer 42 and the third adhesive layer 44) can have a first thickness E4. The first thickness E4 can be between 10 μm and 30 μm. Preferably, the first thickness E4 can be approximately 10 μm.

[0053] Dielectric layers 52, 54, and 56 allow the heating film 6 to be electrically insulated from the rest of band 3 (and therefore electrically insulated from band 3).

[0054] At least a portion of the first dielectric layer 52 and / or the second dielectric layer 54 and / or the third dielectric layer 56 may be made of polyimide or any other material capable of electrically insulating the heating film 6.

[0055] Each of these dielectric layers 52, 54, and 56 may have a second thickness E5. This second thickness E5 may be between 20 μm and 60 μm. Preferably, the second thickness E5 may be approximately 50 μm.

[0056] The shielding layer 7 may include a shielding mesh 70. The shielding mesh provides protection against electromagnetic interference (EMI).

[0057] The shielding layer 7 may include conductive tracks 72 connected to the shielding mesh. The conductive tracks 72 may be configured to connect to the electrical connector 8.

[0058] The shielding layer 7 can be made of copper or any other suitable metal to provide EMI (electromagnetic shielding) protection. Electromagnetic shielding helps reduce electromagnetic fields near the strip. Specifically, the shielding mesh 70 and the conductive track 72 can be made of copper or any other suitable metal to provide EMI protection.

[0059] The shielding layer 7 may have a third thickness E7. This third thickness E7 may be between 35 μm and 90 μm. Preferably, the third thickness E7 may be approximately 70 μm.

[0060] The removable layer 9 can be configured to be removed, allowing the tape 3 to be glued to the tube 1. The removable layer 9 can be made of silicone.

[0061] One feature of this invention is that the heating film 6 includes two conductive strips 64 and 66, which are respectively the first strip 64 and the second strip 66. These two conductive strips extend along the strip 3, and an element 62 with a PTC (Positive Temperature Coefficient) effect extends between these two conductive strips. As described below, the heating film 6 in this configuration allows the fluid to be heated, thawed, and maintained at a uniform temperature throughout the tube 1, while preventing overheating in the event of any malfunction.

[0062] Figures 8a to 11 The image partially shows a strip 3 with a non-restricted arrangement of a heating film 6.

[0063] The PTC effect element 62 can be formed by PTC effect ink printed in a horizontal stripe pattern.

[0064] The element 62 with the PTC effect can extend (especially overlap) over at least a portion of the first 64 and the second 66 (e.g. Figures 4 to 6 (As shown).

[0065] Article 64 and Article 66 may be made of copper or any other conductive material.

[0066] The heating film 6 (particularly the first strip 64 and the second strip 66 and / or the element 62 with the PTC effect) may have a fourth thickness E6. This fourth thickness E6 may be between 35 μm and 90 μm. Preferably, the fourth thickness E6 may be approximately 70 μm. The heating film 6 may be connected to an electrical connector 8 (… Figure 10a and Figure 10b In this way, the heating film 6 can be connected to an external power source, for example, via a conductor (e.g., a wire), to provide electrical power to the heating film. For this purpose, the electrical connector 8 may include a first terminal 82 and a second terminal 84, which can be connected to the external power source. The first terminal 82 can be electrically connected to one of the first strip 64 and the second strip 66 of the heating film 6, and the second terminal 84 can be electrically connected to the other of the first strip 64 and the second strip 66.

[0067] Shielding layer 7 can also be connected to electrical connector 8 ( Figure 10a and Figure 10b Thus, the shielding layer 7 can be connected to the electrical ground, for example, via a conductor (e.g., a wire). For this purpose, the electrical connector 8 may also include a third terminal 86, which can be connected to the electrical ground. This third terminal 86 can be electrically connected to the conductive track 72 of the shielding layer 7. Therefore, the third terminal 86 can be different from the first terminal 82 and the second terminal 84.

[0068] Advantageously, the electrical connector 8 can be connected to the heating film 6 on one side and to the shielding layer 7 on the other. In this configuration, the first terminal 82 and the second terminal 84 can be connected to the first strip 64 and the second strip 66 of the heating film 6, respectively, and the third terminal 86 can be connected to the shielding layer 7.

[0069] Furthermore, the band 3 is in the form of several multi-layered segments 32, each of which has an elongated shape and is connected end to end. Figure 7 and Figure 11 These multi-level segments 32 are identical to each other, and each multi-level segment includes: a) Intermediate portion 322, which is at the second length L of the multi-layer segment 32 32 Extending at least 50%, and b) Two ends 324 and 326, which are the first end 324 and the second end 326 respectively, and the middle portion 322 extends between the two ends.

[0070] The strip 3 can be cut to the desired length at the joint 320 between the multi-layer segments 32.

[0071] As described above, the strip 3, which is in the form of multiple segments 32 and can be cut at the joint 320 between these multiple segments 32, allows the length of the strip 3 to be adjusted to the size of the tube 1.

[0072] The middle part 322 includes: - Optional adhesive layer 4, - A first dielectric layer 52, which may optionally be located above the adhesive layer 4. - A heating film 6 located above the first dielectric layer 52, the heating film 6 including portions of strips 64 and 66 and portions of element 62 having a PTC effect. - The second dielectric layer 54 on the heating film 6, - A shielding layer 7 on the second dielectric layer 52, the shielding layer 7 including a shielding mesh 70, and - The third dielectric layer 56 on the shielding layer 7.

[0073] The first end 324 and the second end 326 are identical, and each includes: - Optional adhesive layer 4, - A first dielectric layer 52, which may optionally be located above the adhesive layer 4. - A heating film 6 located above the first dielectric layer 52, the heating film 6 including portions of strips 64 and 66, but excluding element 62 with PTC effect. - The second dielectric layer 54 on the heating film 6, - A shielding layer 7 on the second dielectric layer 54, the shielding layer 7 including conductive tracks 72 connected to the shielding mesh 70 of the intermediate portion 322, and - The third dielectric layer 56 on the shielding layer 7.

[0074] Therefore, the difference between the first strip 324 and the second strip 326 and the middle part 322 is that there is no element 62 with PTC effect, and the shielding layer 7 only includes conductive tracks 72 and does not have a shielding mesh 70. Figure 8a , Figure 8b , Figure 9 and Figure 11 ).

[0075] The arrangement of layers 4, 42, 44, 52, 54, 56 and / or heating film 6 can vary in the middle portion 322, the first end 324, and the second end 326. For example, refer to Figure 5 The middle portion 322, the first end 324, and the second end 326 may not have the second dielectric layer 54. (See reference) Figure 6 The middle portion 322, the first end 324, and the second end 326 may include a second adhesive layer 42 sandwiched between the heating film 6 and the second dielectric layer 54. (See reference) Figure 7The middle portion 322, the first end 324 and the second end 326 may include a second adhesive layer 42 sandwiched between the heating film 6 and the second dielectric layer 54, and a third adhesive layer 44 sandwiched between the shielding layer 7 and the third dielectric layer 56.

[0076] Advantageously, at least one free end of band 3 can be connected to electrical connector 8. More specifically, first terminal 82 can be electrically connected to one of first band 64 and second band 66, second terminal 84 can be electrically connected to the other of first band 64 and second band 66, and third terminal 86 can be electrically connected to shielding layer 7.

[0077] The free end of the connector 8 connected to the strip 3 can be formed from one of the ends 324, 326 of the multi-layer segment 32. A first terminal 82 can be electrically connected to one of the first strip 64 and the second strip 66 of the ends 324, 326; a second terminal 84 can be electrically connected to the other of the first strip 64 and the second strip 66 of the ends 324, 326; and a third terminal 86 can be electrically connected to the conductive track 72 of the shielding layer 7. Figure 10a or Figure 10b In the example, the second end 326 can be connected to the electrical connector 8.

[0078] Each of these terminals 82, 84, and 86 can be connected to a conductor, which includes an electrical connector 8. The ends 820, 840, and 860 of these conductors can be secured to the free end of the band 3, for example, to a first end 324 and / or a second end 326. For this purpose, each end 820, 84, and 860 may include a lug (e.g., at the first 64 and second 66 of the heating film 6 and the conductive track 72 of the shielding layer 7) to achieve an electrical connection between the conductor of the electrical connector 8 and the free end of the band 3.

[0079] Figure 10a Connecting plates, respectively fixed to the ends 820, 840, and 860 of the conductors of the electrical connector 8, are shown in a non-limiting manner. These connecting plates enable the ends 820, 840, and 860 of the conductors to be connected to the free end of the band 3.

[0080] The ends 820, 840, 860 of the conductor can be secured by, for example, by pressing, gluing and / or overmolding with an electrical insulator.

[0081] For example, Figure 10b An overmolded component 800 is shown that connects the ends 820, 840, 860 of the conductors of the electrical connector 8 to the free end of the band 3. The overmolded component 800 may be made of silicone.

[0082] Advantageously, the first strip 64 and the second strip 66 may have additional thickness at the first end 322 and the second end 324. Figure 8a and Figure 9 ).

[0083] Therefore, each multi-layer segment 32 can have a second length L. 32 The second length L 32 It can be between 5 cm and 50 cm. Preferably, the second length L 32 It can be between 10 cm and 30 cm. The third band can have the same or different second length L. 32 32. Multi-segment.

[0084] The band 3 can have a fifth total thickness E3 between 100 μm and 900 μm.

[0085] The width l3 of the band 3 can be between 10 mm and 100 mm, preferably between 30 mm and 50 mm.

[0086] The heating element 62 with PTC effect can have a width of 2 mm to 10 mm. 62 .

[0087] refer to Figure 8a Width l 62 It is measured between the first 64 and the second 66 in a direction perpendicular to these 64.

[0088] This application will now describe a method for manufacturing the fluid flow tube 1 (as referenced above). Figure 2 and Figure 3 (as described). Figure 12 The steps of this method are summarized.

[0089] According to the present invention, the method includes the following steps: (i) A strip 3 of a certain length is cut according to the length of the tube 1 to be heated. This cutting is performed at the joint 320 between two consecutive multi-layered sections (32). (iii) Assemble the belt 3 around the tubular body 2, preferably in a spiral manner.

[0090] Step (i) can be done using O 320 Cutting tools (e.g., suitable scissors) Figure 11 Do it manually.

[0091] After the strip 3 is cut (particularly at the connector 320), the first 64 and second 66 of the cut multi-layer segments 32, as well as the shielding layer 7, can be exposed, for example, by mechanical processing (e.g., using a flat and adjustable wire stripper to remove one or more layers), chemical processing (e.g., dissolving the shielding layer 7 with a solvent), or thermal processing (e.g., laser ablation). Exposure at the connector 320 involves the partial removal of the different layers located above the heating film 6 and the shielding layer 7. This allows the conductor ends 820, 840, 860 of the electrical connector 8 to be secured to the first 64, second 66, and shielding layer 7 of one of the multi-layer segments 32, respectively, thus forming the free ends of the strip 3.

[0092] Prior to step (iii) of assembling band 3, the method may include step (ii) of attaching electrical connector 8 to band 3.

[0093] Advantageously, the first electrical connector 8 is first positioned and secured at the height of the first free end of the tape 3. The tape 3 can then be manually or automatically wound onto the tubular body 2. The distance d between the consecutive turns 30 30 Adjustable via manual guidance. The second electrical connector 8 can be positioned and secured to the second free end with a 30mm radius. Distance d 30 The length of the tube 1 to be heated and / or the position of the first electrical connector and the second electrical connector 8 can be adjusted.

[0094] More specifically, the conductor ends 820, 840, 860 of each of the first and second electrical connectors 8 can be fixed to the first and second free ends of the strip 3, respectively. For this purpose, these ends 820, 840, 860 can be crimped and / or glued to the first and second free ends of the strip 3. According to another variation, the ends 820, 840, 860 can be crimped to the first and second free ends of the strip 3 and are overmolded with an electrical insulator.

[0095] In step (iii), the belt 3 is assembled around the tubular body 2. For this purpose, the belt 3 can be fixed around the tubular body 2 by spiraling (or coiling).

[0096] Assembly step (iii) can be performed by gluing the tape 3 around the tubular body 2, in particular by using the adhesive layer 4.

[0097] According to another variation, assembly step (iii) can be performed by welding. Welding can be achieved by melting the plastic, and the energy required for melting can be provided by a laser. For example, the tubular body 2 can be melted and welded to the strip 3, and / or the strip 3 (particularly at the level of the dielectric layers 52, 54, 56 of the polyimide material) can be melted and welded to the tubular body 2. Advantageously, welding can be performed by spot welding, for example along the edge of the strip 3, or in the middle of the strip 3 (e.g., at the cut joint 320). Welding simplifies step (iii) by simultaneously positioning the strip 3 on the tubular body 2 and securing it by welding.

Claims

1. A multilayer heating belt (3), specifically for use in a fluid flow tube (1), the belt (3) having an elongated shape and comprising a plurality of stacked layers, the plurality of stacked layers comprising at least: - First dielectric layer (52). - A heating film (6) located above the first dielectric layer (52). - The second dielectric layer (54) on the heating film (6). - The shielding layer (7) on the second dielectric layer (54), and - The third dielectric layer (56) on the shielding layer (7). The heating film (6) is characterized in that it comprises two conductive strips (64, 66) extending along the strip (3), and an element (62) having a PTC (positive temperature coefficient) effect extends between the two conductive strips. The band (3) is in the form of several multi-layered segments (32), each of which has an elongated shape and is connected end to end. The several multi-layered segments (32) are identical and each multi-layered segment includes: a) an intermediate portion (322) extending over at least 50% of the length of the multi-layer segment (32) and comprising: - The first dielectric layer (52). - The heating film (6) located above the first dielectric layer (52) includes portions of the strips (64, 66) and portions of the element (62) having a PTC effect. - The second dielectric layer (54) on the heating film (6). - The shielding layer (7) on the second dielectric layer (54), the shielding layer (7) comprising a shielding mesh (70), and - The third dielectric layer (56) on the shielding layer (7), and b) Two ends (324, 326), the middle portion (322) extending between the two ends, the two ends (324, 326) being identical and each end comprising: - The first dielectric layer (52). - A heating film (6) located above the first dielectric layer, the heating film (6) including portions of the strips (64, 66), but without elements (62) having the PTC effect. - The second dielectric layer (54) on the heating film (6). - The shielding layer (7) on the second dielectric layer (54), the shielding layer (7) including conductive tracks (72) connected to the shielding mesh (70) of the intermediate portion (322), and - The third dielectric layer (56) on the shielding layer (7). Furthermore, the strip (3) can be cut to the desired length at the joint (320) between the plurality of multi-layer segments (32).

2. The multi-layer heating belt according to claim 1 or 2, wherein, Each of the layers (4, 42, 44, 52, 54, 56, 7) or the film (6) has a thickness of 10 μm to 100 μm, and the strip (3) has a total thickness (E3) of 100 μm to 900 μm.

3. The multi-layer heating belt according to any one of claims 1 to 3, wherein, The width (l3) of the multi-layer heating band is between 10 mm and 100 mm, preferably between 30 mm and 50 mm.

4. The multi-layer heating belt according to any one of claims 1 to 4, wherein, Each of the strips (64, 66) has an additional thickness at each of the two ends (324, 326).

5. The multi-layer heating belt according to any one of claims 1 to 5, wherein, One of the free ends of the strip (3) is connected to an electrical connector (8), which includes three terminals: a first terminal (82), a second terminal (84), and a third terminal (86). The first terminal is electrically connected to one of the strips (64, 66), the second terminal is electrically connected to the other of the strips (64, 66), and the third terminal is electrically connected to the shielding layer (7).

6. The multi-layer heating belt according to claim 6, wherein, The free end of the strip (3) is formed by the end (324, 326) of one of several multi-layered segments (32) of the strip, the first terminal (82) being electrically connected to one of the strips (64, 66) at that end, the second terminal (84) being electrically connected to the other of the strips (64, 66) at that end, and the third terminal (86) being electrically connected to the conductive track (72) at that end.

7. The multi-layer heating belt according to claim 6 or 7, wherein, The terminals (82, 84, 86) of the electrical connector (8) are connected to a conductor, the end of which is fixed to the free end of the strip (3).

8. The multi-layer heating belt according to any one of claims 1 to 8, wherein, The strip (3) further includes at least one adhesive layer (4, 42, 44) in the stacked layers, and wherein the middle portion (322) and the ends (324, 326) include at least one adhesive layer (4, 42, 44).

9. The multi-layer heating belt according to claim 9, wherein, The first dielectric layer (52) is located above the adhesive layer (4).

10. The multi-layer heating belt according to claim 9 or 10, wherein, Among the first dielectric layer (52), the heating film (6), the second dielectric layer (54), the shielding layer (7), and the third dielectric layer (56), the adhesive layer (42, 44) is located between the two stacked layers of the strip (3).

11. A fluid flow tube (1), particularly for use in the aerospace industry, the fluid flow tube comprising a tubular body (2) and a multilayer heating band (3) according to any one of claims 1 to 10, the band (3) being attached to and assembled onto the tubular body (2).

12. The fluid flow pipe according to claim 11, wherein, The multi-layer heating band (3) is spirally wound around the tubular body (2).

13. A wastewater discharge circuit (10) for an aircraft, the wastewater discharge circuit comprising a fluid flow pipe (1) according to claim 11 or 12.

14. A method for manufacturing a fluid flow pipe (1) according to claim 11 or 12, the method comprising the following steps: (i) A strip (3) of a certain length is cut according to the length of the tube (1) to be heated, the cutting being performed at the joint (320) between two consecutive multi-layered segments (32). (iii) Assemble the belt (3) around the tubular body (2), preferably in a spiral manner.

15. The manufacturing method according to claim 14, wherein, Prior to step (iii) of assembling the band (3), the method includes step (ii) of attaching at least one electrical connector (8) to the band (3).

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