High temperature resistant electrically heated bushing

Abstract

The utility model provides a kind of high-temperature-resistant electric heat melting sleeve, it relates to electric heat melting sleeve technical field, including electric heat melting sleeve body, the electric heat melting sleeve body is by composite layer and outer protective layer composite forming, the composite layer includes electric heat melting net layer, first electric heat melting net and second electric heat melting net are sequentially arranged from outside to inside along radial direction in the electric heat melting net layer, the outer protective layer includes insulating layer, multiple microcapsule phase change pieces are evenly dispersed and arranged in the insulating layer inside;The utility model is designed by double-layer different power density electric heat melting net, outer layer low-power density alloy wire forms heat preservation solidification area, provides uniform post-solidification heat for weld, inner layer high-power density alloy wire forms high-temperature zone, realizes material rapid melting, gradient heat conduction structure realizes the space-time temperature control of welding process, both avoids the problem of surface overheating carbonization and internal unmelted, and can optimize polymer molecular orientation and crystallinity, improve weld strength and sealing property.

Description

Technical Field

[0001] This utility model relates to the field of electrothermal welding sleeve technology, and in particular to a high-temperature resistant electrothermal welding sleeve. Background Technology

[0002] In engineering fields such as pipeline connection and equipment sealing, electrothermal fusion sleeves are widely used in petrochemical, municipal pipeline, and water conservancy projects because they can achieve material melting and welding through electrothermal action and have advantages such as convenient operation and good connection sealing. Currently, most electrothermal fusion sleeves on the market adopt a single power density heating wire structure, which makes it difficult to achieve precise temperature field control during operation. The outer layer often overheats and carbonizes while the inner layer is not fully melted, resulting in insufficient weld strength and poor sealing. This makes it impossible to meet the long-term use requirements under complex working conditions such as high pressure and high temperature. At the same time, uneven heating can easily cause local material damage, shortening the overall service life of the electrothermal fusion sleeve.

[0003] Furthermore, existing electrothermal fuselage jacket outer sheath designs mostly focus on basic insulation or wear resistance, lacking effective temperature buffering and emergency protection mechanisms. When the electrothermal fuselage jacket experiences localized abnormal temperature increases due to circuit failure, external heat source influence, or aging of heating elements, it cannot absorb excess heat in time to suppress the temperature surge. This may not only lead to insulation layer failure and electrical safety accidents, but also cause deterioration of the fuselage jacket material performance, and even cause overall structural failure, seriously affecting the quality of engineering construction and the safety of subsequent operation. It is difficult to adapt to modern engineering application scenarios with increasingly higher requirements for reliability and high temperature resistance. Based on this, a high-temperature resistant electrothermal fuselage jacket is proposed here. Utility Model Content

[0004] To address the shortcomings of the existing technology, this utility model proposes a high-temperature resistant electrothermal welding sleeve.

[0005] The technical solution of this utility model is achieved as follows: a high-temperature resistant electrothermal fusion sleeve includes an electrothermal fusion sleeve body, which is formed by a composite layer and an outer protective layer. The composite layer includes an electrothermal fusion mesh layer, in which a first electrothermal fusion mesh and a second electrothermal fusion mesh are arranged radially from the outside to the inside. The first electrothermal fusion mesh is woven from low-power-density alloy wire, and the second electrothermal fusion mesh is woven from high-power-density alloy wire. The outer protective layer includes an insulating layer, in which multiple microcapsule phase change elements are uniformly dispersed.

[0006] Preferably, the composite layer further includes a composite heat layer, a heat-resistant layer, and a connecting reinforcement layer, wherein the electrothermal fused mesh layer is disposed between the composite heat layer and the heat-resistant layer, and the connecting reinforcement layer is disposed between the heat-resistant layer and the outer protective layer.

[0007] Preferably, the composite thermal layer includes a hot melt layer and a heat-conducting layer, with the heat-conducting layer closely bonded to the electrothermal mesh layer.

[0008] Preferably, the outer protective layer further includes a wear-resistant layer, which is fixed to the outside of the insulating layer, and the outer surface of the wear-resistant layer is provided with an anti-slip texture structure.

[0009] Preferably, the insulating layer has multiple phase change cavities, which are uniformly distributed in an array, and each phase change cavity contains at least one microcapsule phase change element.

[0010] Preferably, both ends of the electrothermal sleeve body are fixed with annular reinforcing strips.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. In use, this utility model employs a double-layer electrothermal melting mesh design with different power densities. The outer layer of low-power-density alloy wire forms a heat-insulating curing zone, providing uniform post-curing heat for the weld. The inner layer of high-power-density alloy wire forms a high-temperature zone, enabling rapid melting of the material. The gradient heat conduction structure achieves spatiotemporal temperature control during the welding process, avoiding both surface overheating and carbonization and internal unmelted areas. It also optimizes polymer molecular orientation and crystallinity, improving weld strength and sealing performance. Simultaneously, the long-term post-curing environment promotes polymer molecular chain relaxation, rearrangement, and crystallization, effectively eliminating internal stress and significantly enhancing the long-term creep resistance and impact toughness of the weld, meeting the needs of use under complex working conditions.

[0013] 2. When this utility model is in use, the microcapsule phase change components in the outer protective insulating layer are distributed in an array. By utilizing the solid-liquid phase change process of the phase change material at a specific temperature point, it can quickly absorb the locally abnormally increased heat, effectively suppress further temperature rise, and prevent the material from burning due to uneven heating, external fire sources, etc. When the temperature returns to normal, the phase change material can release heat and solidify, returning to its initial state, forming a dynamic temperature buffer mechanism.

[0014] 3. The embedded distributed sensor array can monitor the welding temperature field distribution in real time and also enable long-term monitoring of joint strain, microcracks and other health conditions, providing support for predictive maintenance of equipment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1This is a schematic diagram of the overall structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the composite layer structure of this utility model;

[0018] Figure 3 This is a schematic diagram of the structure of the outer protective layer of this utility model;

[0019] Figure 4 This is a schematic diagram of the structure of the electrothermal fusion mesh layer of this utility model.

[0020] In the figure: 1. Electrothermal fusel body; 11. Composite heating layer; 12. Electrothermal fusel mesh layer; 13. Heat-resistant layer; 14. Connecting reinforcement layer; 2. Outer protective layer; 21. Insulation layer; 22. Wear-resistant layer; 23. Phase change cavity; 24. Microcapsule phase change element; 3. Annular reinforcing strip; 4. First electrothermal fusel mesh; 5. Second electrothermal fusel mesh. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] like Figures 1-4 As shown, a high-temperature resistant electrofusion sleeve includes an electrofusion sleeve body 1, which is formed by a composite layer and an outer protective layer 2. Both ends of the electrofusion sleeve body 1 are fixed with annular reinforcing strips 3. The cross-section of the annular reinforcing strips 3 is L-shaped. The inner ring of the annular reinforcing strip 3 is flush with the inner surface of the electrofusion sleeve body 1, and the outer ring extends to the outer side of the outer surface of the electrofusion sleeve body 1. Multiple positioning holes are evenly distributed on the annular reinforcing strips 3 for positioning and fixing during the installation of the electrofusion sleeve. The core structure of the composite layer is an electrofusion mesh layer 12. The electrofusion mesh layer 12 is radially arranged with a first electrofusion mesh 4 and a second electrofusion mesh 5 from the outside to the inside. The ends of the first electrofusion mesh 4 and the second electrofusion mesh 5 are... The surface is fixedly connected with copper wires. The first electrofusion mesh 4 is woven from low-power-density alloy wire, and the second electrofusion mesh 5 is woven from high-power-density alloy wire. This makes the outer layer a heat preservation / curing zone, where low-power-density wire provides uniform post-curing heat, while the inner layer is a high-temperature zone, where high-power-density wire enables rapid melting. This results in a gradient distribution of heat conduction in the fusion sleeve, achieving spatiotemporal control of the welding process. This means providing the most suitable temperature field at different times and in different areas. This not only avoids the embarrassing situation of surface overheating and carbonization without internal melting, but also optimizes the orientation and crystallinity of polymer molecules, resulting in welds with higher strength and better sealing. This makes it suitable for pipes with thicker walls and larger diameters.

[0023] Specifically, after the fusion welding is completed in the inner high-temperature zone, the outer layer continues to maintain a relatively high temperature (below the melting point), providing a long-term post-curing environment for the weld area. This allows the polymer molecular chains sufficient time to relax, rearrange, and crystallize, effectively eliminating internal stress and significantly improving the long-term creep resistance and impact toughness of the weld.

[0024] In addition, distributed fiber optic sensors or printed resistance temperature sensor arrays can be embedded coplanarly next to the electrothermal welding mesh. These sensors are integrated with the heating wire during the manufacturing process, which can not only monitor and provide feedback on the temperature field distribution of the entire welding area in real time, but also serve as a permanent health monitoring system after welding to monitor the strain, microcrack initiation and other conditions at the joint in the long term, thus enabling predictive maintenance.

[0025] See Figure 3 As shown, the outer sheath 2 includes an insulation layer 21, which effectively prevents current leakage and avoids safety accidents caused by electrical faults, providing a stable electrical environment for the entire electrothermal fuselage. Multiple microcapsule phase change elements 24 are uniformly dispersed inside the insulation layer 21. Multiple phase change cavities 23 are formed within the insulation layer 21, and these cavities are evenly distributed in an array. Each phase change cavity 23 contains at least one microcapsule phase change element 24. The microcapsule phase change elements 24 are used to ensure that the temperature during the operation of the electrothermal fuselage does not exceed that of the insulation layer. The microcapsule phase change element 24 has a thickness of 21 and its outer shell is made of high-temperature resistant resin material. The microcapsule encapsulates phase change energy storage material inside. The phase change temperature of the microcapsule is slightly higher than the normal operating temperature, but much lower than the material damage temperature. For example, when the normal operating temperature is 150°C, the phase change temperature of the microcapsule phase change element 24 may be selected at around 160°C, while the material damage temperature may be above 250°C. In this way, when the temperature accidentally rises to around 160°C, the microcapsule phase change element 24 can respond quickly to prevent the temperature from continuing to rise and causing damage to the material.

[0026] For phase change energy storage materials, inorganic salts or alloys can be selected. If the normal operating temperature range of the electrothermal sleeve is set to 170℃-230℃, an inorganic salt mixture (such as a sodium nitrate-potassium nitrate mixture) can be selected.

[0027] When the temperature in a localized area rises abnormally due to unforeseen circumstances (such as uneven heating or external fire sources), the phase change material absorbs a large amount of heat and undergoes a phase change (solid to liquid), thereby effectively suppressing further temperature spikes and preventing the material from burning. When the temperature returns to normal, the phase change material releases the previously stored heat and re-solidifies, returning to its initial state. This gives the electrothermal jacket high safety and reliability, preventing overall failure due to single-point overheating.

[0028] See Figure 2 As shown, the composite layer also includes a composite heat layer 11, a heat-resistant layer 13, and a connecting reinforcement layer 14. The electrothermal fusion mesh layer 12 is disposed between the composite heat layer 11 and the heat-resistant layer 13, and the connecting reinforcement layer 14 is disposed between the heat-resistant layer 13 and the outer protective layer 2. The heat-resistant layer 13 is made of high-temperature resistant ceramic fiber composite material and the heat-resistant layer 14 is made of glass fiber reinforced resin material.

[0029] The composite heat layer 11 includes a heat-melting layer and a heat-conducting layer. The heat-conducting layer is tightly bonded to the electrothermal fusion mesh layer 12. The heat-conducting layer is used to uniformly conduct the heat generated by the electrothermal fusion mesh layer 12. The heat-melting layer is made of modified hot melt adhesive material and is used to achieve the sealing and fixing of the electrothermal fusion sleeve and the pipe to be connected. Specifically, when heated, the modified hot melt adhesive can melt rapidly and fill the tiny gaps between the electrothermal fusion sleeve and the pipe to be connected to form a tight sealing structure, effectively preventing the leakage of liquids and gases. After cooling, it can firmly bond to the surface of the pipe to achieve reliable fixing and ensure that the connection will not loosen during long-term use.

[0030] See Figure 3 As shown, the outer protective layer 2 further includes a wear-resistant layer 22, which is fixed to the outside of the insulation layer 21. The wear-resistant layer 22 can be fixed to the outer surface of the insulation layer 21 by co-extrusion molding process. The wear-resistant layer 22 is made of ultra-high molecular weight polyethylene material with a thickness of 0.5-3mm, and the outer surface of the wear-resistant layer 22 is provided with an anti-slip texture structure.

[0031] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-temperature resistant electrothermal fuselage sleeve, comprising an electrothermal fuselage sleeve body (1), wherein the electrothermal fuselage sleeve body (1) is formed by composite layer and outer sheath (2), characterized in that: The composite layer includes an electrothermal fusion mesh layer (12), wherein the electrothermal fusion mesh layer (12) is provided with a first electrothermal fusion mesh (4) and a second electrothermal fusion mesh (5) in a radial direction from the outside to the inside. The first electrothermal fusion mesh (4) is woven from low power density alloy wire, and the second electrothermal fusion mesh (5) is woven from high power density alloy wire. The outer protective layer (2) includes an insulating layer (21), wherein a plurality of microcapsule phase change elements (24) are uniformly dispersed inside the insulating layer (21).

2. The high-temperature resistant electrothermal fusion sleeve according to claim 1, characterized in that: The composite layer also includes a composite heat layer (11), a heat-resistant layer (13), and a connecting reinforcement layer (14). The electrothermal fused mesh layer (12) is disposed between the composite heat layer (11) and the heat-resistant layer (13), and the connecting reinforcement layer (14) is disposed between the heat-resistant layer (13) and the outer protective layer (2).

3. The high-temperature resistant electrothermal fusion sleeve according to claim 2, characterized in that: The composite thermal layer (11) includes a hot melt layer and a heat-conducting layer, with the heat-conducting layer closely attached to the electrothermal mesh layer (12).

4. The high-temperature resistant electrothermal fusion sleeve according to claim 1, characterized in that: The outer protective layer (2) also includes a wear-resistant layer (22), which is fixed to the outside of the insulating layer (21), and the outer surface of the wear-resistant layer (22) is provided with an anti-slip texture structure.

5. The high-temperature resistant electrothermal fusion sleeve according to claim 1, characterized in that: The insulating layer (21) has multiple phase change cavities (23) in an array, and each phase change cavity (23) has at least one microcapsule phase change element (24).

6. The high-temperature resistant electrothermal fusion sleeve according to claim 1, characterized in that: Both ends of the electrothermal sleeve body (1) are fixed with annular reinforcing strips (3).

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