End sealing structure of high-voltage heating pipe

Abstract

The invention belongs to the technical field of high-voltage heating pipes, and particularly relates to a high-voltage heating pipe end sealing structure which comprises a heating pipe body, and the heating pipe body is composed of a metal pipe body shell, an electric heating wire and a lead-out rod. A ceramic insulating medium is arranged in the metal tube body shell, the center of the metal tube body shell is provided with an electric heating wire and a lead-out rod, and the outer surface of the lead-out rod is sleeved with a spiral fastening assembly; the high-voltage heating pipe can meet the requirement for the electrical performance of the high-voltage heating pipe body under the long-term operation condition, and the creepage distance is increased by adopting the interference fit mode of the spiral fastening assembly and the heating pipe body. And long-term operation of the high-voltage heating pipe body can be realized. Insulating media are high-dielectric-strength insulating media, and the ceramic insulating media of the assembly component and the heating pipe body are of a concave surface structure and are filled with sealant.

Description

Technical Field

[0001] The invention belongs to the technical field of high-voltage heating tubes, in particular to a sealing structure for the end of a high-voltage heating tube. Background Art

[0002] The electric heating tube is a metal tubular electric heating element, mainly composed of a metal shell, a heating wire, an insulating layer, a sealing structure and a lead rod. Its heating mechanism is based on Joule's law. The insulating layer is generally pressed with magnesium oxide powder. When the heating tube is in a high temperature state and a low voltage state for a long time, the end is generally not processed. However, considering the hygroscopicity of magnesium oxide powder, the end of the electric heating tube will be sealed with insulating oil, rubber and other materials.

[0003] The technology of low-voltage electric heating tubes is mature, but there is no technical breakthrough in high-voltage electric heating tubes. Compared with low-voltage electric heaters, high-voltage electric heating tubes can eliminate the equipment and design of low-voltage power distribution, greatly saving the power distribution cost of the electric heater system, and improve the comprehensive electric-heat conversion efficiency of the system, thereby improving the overall economic benefits of the project. Under high voltage conditions, the processing of the end is crucial, and electrical issues such as creepage distance and electrical clearance need to be considered to meet the requirements of electrical performance; on the other hand, issues such as sealing and process manufacturing must also be considered to meet the requirements of the use environment and actual production and manufacturing.

[0004] To this end, the present invention provides a high-voltage heating tube end sealing structure. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0006] The technical solution adopted by the present invention to solve its technical problem is: a high-voltage heating tube end sealing structure described in the present invention includes a heating tube body, and the heating tube body is composed of a metal tube body shell, a heating wire and a lead-out rod; the interior of the metal tube body shell is a ceramic insulating medium, and the heating wire and the lead-out rod are arranged in the center of the metal tube body shell, the outer surface of the lead-out rod is sleeved with a spiral fastening component, the outer surface of the heating wire is provided with an assembly component, and the insulating medium filler is filled between the heating wire and the ceramic insulating medium.

[0007] Furthermore, the threads of the spiral fastening component and the connecting part of the assembly component match, the spiral fastening component and the assembly component are both made of insulating materials with high mechanical strength and high dielectric strength, and the total length of the spiral fastening component is greater than the connecting part with the assembly component.

[0008] Furthermore, a gap is provided between the ceramic insulating medium inside the metal tube body shell and the assembly component, and the gap between the ceramic insulating medium inside the metal tube body shell and the assembly component is filled with insulating glue.

[0009] Furthermore, the ceramic insulating medium inside the metal tube shell is made of an insulating medium with high dielectric strength and high thermal conductivity.

[0010] Furthermore, a rubber pad is fixedly installed at the bottom of the connection part between the assembly component and the spiral fastening component, and the rubber pad is made of insulating material.

[0011] Furthermore, the insulating medium filler is a dielectric powder with high dielectric constant and high thermal conductivity.

[0012] Furthermore, there is a gap between the heating wire and the insulating heat-conducting medium, and the gap is filled with insulating material.

[0013] Furthermore, the assembly component is connected to the insulating heat-conducting medium inside the metal tube shell by using insulating glue.

[0014] Furthermore, the insulating adhesive is a high-temperature insulating adhesive.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. The sealing structure at the end of a high-voltage heating tube described in the present invention can meet the requirements of the electrical performance of the high-voltage heating tube body under long-term operation conditions through the structure designed in the application, and the spiral fastening component and the heating tube body adopt an interference fit to increase the creepage distance. The long-term operation of the high-voltage heating tube body can be achieved. The insulating medium of the present invention adopts an insulating medium with high dielectric strength, and the assembly component and the ceramic insulating medium of the heating tube body adopt a concave structure and are filled with sealant. At the same time, the structure designed in this application can be used for high-voltage electric heaters, which saves the power distribution cost of the electric heater system compared to low-voltage electric heaters and improves the comprehensive electric-heat conversion efficiency of the system.

[0017] 2. The sealing structure of the end of a high-voltage heating tube described in the present invention can reduce the difficulty of process manufacturing by making the assembly component separately. The assembly component and the insulating heat-conducting medium are connected with high-temperature insulating glue, which, on the one hand, increases the mechanical strength of the heating tube body as a whole, and on the other hand, avoids the air gap between the assembly component and the insulating heat-conducting medium, which reduces the electrical performance of the heating tube body as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1A schematic diagram of a cross-sectional structure of an end portion of a lead-out rod provided in an embodiment of the present invention;

[0020] Figure 2 A schematic cross-sectional view of a single-ended heating tube body provided in an embodiment of the present invention;

[0021] Figure 3 A schematic cross-sectional view of a U-shaped heating tube body provided in an embodiment of the present invention;

[0022] Figure 4 A schematic cross-sectional view of a double-ended heating tube body provided in an embodiment of the present invention.

[0023] In the figure: 1. Lead-out rod; 2. Screw fastening assembly; 3. Rubber pad; 4. Insulating glue; 5. Metal tube shell; 6. Assembly assembly; 7. Heating wire; 8. Insulating material; 9. Insulating heat-conducting medium; 10. Heating tube body. DETAILED DESCRIPTION

[0024] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0025] like Figures 1 to 4 As shown, a high-voltage heating tube end sealing structure described in an embodiment of the present invention includes a heating tube body 10, and the heating tube body 10 is composed of a metal tube body shell 5, a heating wire 7 and a lead-out rod 1; the interior of the metal tube body shell 5 is a ceramic insulating medium, and the heating wire 7 and the lead-out rod 1 are arranged in the center of the metal tube body shell 5. The outer surface of the lead-out rod 1 is sleeved with a spiral fastening component 2, and the outer surface of the heating wire 7 is provided with an assembly component 6. The insulating medium filler is filled between the heating wire 7 and the ceramic insulating medium. The insulating medium filler is a dielectric powder with a high dielectric constant and high thermal conductivity. The threads of the connecting part of the spiral fastening component 2 and the assembly component 6 are matched, and the spiral fastening component 2 and the assembly component 6 are both insulating materials 8 with high mechanical strength and high dielectric strength. The total length of the spiral fastening component 2 is greater than the connecting part with the assembly component 6.

[0026] Specifically, there is a gap between the ceramic insulating medium inside the metal tube body shell 5 and the assembly component 6, and the gap between the ceramic insulating medium inside the metal tube body shell 5 and the assembly component 6 is filled with insulating glue 4. The ceramic insulating medium inside the metal tube body shell 5 is made of an insulating medium with high dielectric strength and high thermal conductivity. A rubber pad 3 is fixedly installed at the bottom of the connection part between the assembly component 6 and the spiral fastening component 2, and the rubber pad 3 is made of insulating material 8. There is a gap between the heating wire 7 and the insulating heat-conducting medium 9, and the gap is filled with insulating material 8. The assembly component 6 and the insulating heat-conducting medium 9 inside the metal tube body shell 5 are connected with insulating glue 4.

[0027] During operation, the insulating heat-conducting medium 9, the spiral fastening component 2, and the assembly component 6 are all made of materials with high insulation performance and high thermal conductivity, such as magnesium oxide ceramics, aluminum nitride ceramics, etc., and are adopted according to actual working conditions. The high insulation performance is because the heating tube body 10 is used under high voltage conditions, and the heating tube body 10 needs to meet the corresponding electrical performance. The electrical clearance and creepage distance are related to the insulation performance of the material. Material properties: Generally, the larger the relative dielectric constant and the higher the density, the better the insulation performance of the material, and the better the pressure resistance of the material, which can meet the long-term operation requirements of the heating tube body 10 under high voltage environments. The insulating material 8 is filled between the heating wire 7 and the insulating heat-conducting medium 9. The insulating material 8 is made of a material with high insulation performance and high thermal conductivity. It can be filled with fluid or powdered materials, such as magnesium oxide ceramic powder. The heating wire 7 is assembled in a spiral shape between the insulating heat-conducting medium 9, and there is an air gap in the middle. The relative dielectric constant and density of air are lower than those of the insulating heat-conducting medium 9. The closer to the heating wire 7, the higher the voltage and the greater the electric field strength. Under such conditions, the air can be easily broken down, causing the heating tube body 10 to be unable to be used for a long time. Therefore, the gap between the heating wire 7 and the insulating heat-conducting medium 9 needs to be filled with a material with high insulation performance.

[0028] The spiral fastening component 2 and the assembly component 6 are assembled by interference fit. The spiral fastening component 2 is relatively long and is higher than the metal tube housing 5 after assembly. The assembly component 6 is flush with the metal tube housing 5 after assembly. The protruding part of the spiral fastening component 2 can increase the creepage distance between the lead-out rod 1 and the metal tube housing 5. A rubber pad 3 is provided at the bottom of the assembly component 6 to play a buffering role and prevent the spiral fastening component 2 and the assembly component 6 from slipping due to excessive force.

[0029] It is difficult to integrate the assembly component 6 with the insulating heat-conducting medium 9 inside the metal tube shell 5 in terms of technology. Making the assembly component 6 separately can reduce the difficulty of process manufacturing. The assembly component 6 and the insulating heat-conducting medium 9 are connected by insulating glue 4, which, on the one hand, increases the overall mechanical strength of the heating tube body 10, and on the other hand, avoids the existence of an air gap between the assembly component 6 and the insulating heat-conducting medium 9, which reduces the overall electrical performance of the heating tube body 10.

[0030] Preferably, the insulating glue 4 is made of high-temperature insulating glue.

[0031] The structure designed in the application can meet the requirements of electrical performance under long-term operation conditions of the high-voltage heating tube body 10, and the spiral fastening component 2 and the heating tube body 10 adopt an interference fit to increase the creepage distance. The long-term operation of the high-voltage heating tube body 10 can be achieved. The insulating medium of the present invention adopts an insulating medium with high dielectric strength, and the assembly component 6 and the ceramic insulating medium of the heating tube body 10 adopt a concave structure and are filled with sealant. At the same time, the structure designed in the application can be used for high-voltage electric heaters, which saves the power distribution cost of the electric heater system compared to low-voltage electric heaters and improves the comprehensive electric-heat conversion efficiency of the system.

[0032] Working principle: The spiral fastening component 2 and the assembly component 6 are assembled by interference fit. The spiral fastening component 2 is relatively long and should be higher than the metal tube shell 5 after assembly. The assembly component 6 is flush with the metal tube shell 5 after assembly. The protruding part of the spiral fastening component 2 can increase the creepage distance between the lead-out rod 1 and the metal tube shell 5. A rubber pad 3 is provided at the bottom of the assembly component 6 to play a buffering role and prevent the spiral fastening component 2 and the assembly component 6 from slipping due to excessive force.

[0033] It is difficult to integrate the assembly component 6 with the insulating heat-conducting medium 9 inside the metal tube shell 5 in terms of technology. Making the assembly component 6 separately can reduce the difficulty of process manufacturing. The assembly component 6 and the insulating heat-conducting medium 9 are connected by insulating glue 4, which, on the one hand, increases the overall mechanical strength of the heating tube body 10, and on the other hand, avoids the existence of an air gap between the assembly component 6 and the insulating heat-conducting medium 9, which reduces the overall electrical performance of the heating tube body 10.

[0034] The above-mentioned front, back, left, right, top and bottom are all based on the figures in the specification. Figure 1 As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0036] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A high voltage heating tube end sealing structure, characterized in that: It comprises a heating tube body (10), wherein the heating tube body (10) is composed of a metal tube shell (5), an electric heating wire (7) and a lead-out rod (1); The interior of the metal tube shell (5) is a ceramic insulating medium. A heating wire (7) and a lead-out rod (1) are arranged at the center of the metal tube shell (5). A spiral fastening component (2) is sleeved on the outer surface of the lead-out rod (1). An assembly component (6) is arranged on the outer surface of the heating wire (7). An insulating medium filler is filled between the heating wire (7) and the ceramic insulating medium.

2. A high voltage heating tube end sealing structure according to claim 1, characterized in that: The threads of the connecting part of the spiral fastening component (2) and the assembly component (6) match each other. Both the spiral fastening component (2) and the assembly component (6) are made of insulating materials (8) with high mechanical strength and high dielectric strength. The total length of the spiral fastening component (2) is greater than the connecting part with the assembly component (6).

3. The high voltage heating tube end sealing structure according to claim 1, characterized in that: A gap is provided between the ceramic insulating medium inside the metal tube shell (5) and the assembly component (6), and the gap between the ceramic insulating medium inside the metal tube shell (5) and the assembly component (6) is filled with insulating glue (4).

4. The high voltage heating tube end sealing structure according to claim 1, characterized in that: The ceramic insulating medium inside the metal tube shell (5) is made of an insulating medium with high dielectric strength and high thermal conductivity.

5. The high voltage heating tube end sealing structure according to claim 1, characterized in that: A rubber pad (3) is fixedly installed at the bottom of the connection portion between the assembly component (6) and the screw fastening component (2), and the rubber pad (3) is made of an insulating material (8).

6. The high voltage heating tube end sealing structure according to claim 1, characterized in that: The insulating medium filler is a dielectric powder with high dielectric constant and high thermal conductivity.

7. A high voltage heating tube end sealing structure according to claim 6, characterized in that: There is a gap between the heating wire (7) and the insulating heat-conducting medium (9), and the gap is filled with an insulating material (8).

8. The high voltage heating tube end sealing structure according to claim 7, characterized in that: The assembly component (6) is connected to the insulating heat-conducting medium (9) inside the metal tube shell (5) using insulating glue (4).

9. A high voltage heating tube end sealing structure according to claim 3 or 8, characterized in that: The insulating glue (4) is a high-temperature insulating glue.

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