End sealing structure of double-end high-voltage heating pipe

Abstract

The invention belongs to the technical field of electric heating tubes, and particularly relates to a double-end high-voltage heating tube end sealing structure which comprises an electric heating tube composed of a metal outer tube, an electric heating wire and a lead-out rod. Two symmetrically arranged electric heating wires and two symmetrically arranged lead-out rods are mounted in the electric heating pipe; according to the invention, the requirement of an electrical gap under a high-voltage condition is met, the adopted insulating medium adopts an insulating material with high dielectric strength, a certain angle is formed in the insulating assembling component to enlarge the distance between the two lead-out rods, and the insulating material is arranged outside the lead-out rods, so that when the lead-out rods are in the air, the lead-out rods are separated from each other; and the requirement of an electrical gap can still be met. And meanwhile, the requirement of creepage under a high-voltage condition is met. And the difficulty of process preparation is reduced, and the assembly component can be independently prepared. Meanwhile, compared with a low-voltage electric heater, the high-voltage electric heater saves the power distribution cost of an electric heater system and improves the comprehensive electro-thermal conversion efficiency of the system.

Description

Technical Field

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

[0002] The electric heating tube is a heating element that converts electrical energy into thermal energy. It is widely used in many fields such as industry, home, and experimental equipment. The electric heating tube is mainly composed of a metal shell, a heating wire, an insulating layer, a sealing structure, and a lead-out rod. The working principle of its heating is based on Joule's law, that is, when current passes through a conductor, the resistance of the conductor will convert part of the electrical energy into thermal energy. The resistance wire will generate heat after being energized, and the heat will be transferred to the outside of the electric heating tube through conduction, and the surrounding medium, such as water, air, or oil, will be heated. The electric heating tube can not only work stably for a long time in a high temperature environment, but also can accurately control the temperature according to actual needs during the heating process based on the control principle combined with thyristors or other switching elements.

[0003] High-voltage electric heating tubes mainly need to solve the problem of electrical safety distance of electric heating tubes under high voltage conditions. Generally speaking, the higher the voltage, the greater the required safety distance, and the greater the distance between the lead-out rod of the electric heating tube and the electric heating wire, which means that the tube body of the electric heating tube needs to be thicker. The distance between different electric heating tubes should also be larger, and the electric heater assembled from the electric heating tubes should also be larger. For double-ended electric heating tubes, if the ends are not processed under high voltage conditions, on the one hand, the creepage distance between the lead-out rod and the metal outer tube of the electric heating tube needs to be larger; on the other hand, the two lead-out rods of the double-ended electric heating tube are led out from the same end, and the distance between different lead-out rods should also be increased. If the ends of the double-ended electric heating tubes are not processed, the diameter of the electric heating tube needs to be larger to meet the requirements of electrical performance, but the diameter of the electric heating tube is too large to meet the requirements of the heat dissipation performance of the electric heating tube, and the excessively thick diameter cannot be achieved in actual manufacturing and use.

[0004] To this end, the present invention provides a double-ended 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 double-end high-voltage heating tube end sealing structure described in the present invention includes an electric heating tube, and the electric heating tube is composed of a metal outer tube, an electric heating wire and a lead-out rod; two symmetrically arranged electric heating wires and two symmetrically arranged lead-out rods are installed in the electric heating tube, the electric heating wire is connected to the lead-out rod, an insulating assembly component is arranged outside the lead-out rod, an insulating medium is filled between the electric heating wire and the metal outer tube, an insulating material is filled between the insulating medium and the electric heating wire, and the cross-section of the metal outer tube is in a "U" shape.

[0007] Furthermore, the side surfaces of the two lead-out rods are stepped, the spacing between the parts of the two lead-out rods inside the insulating assembly is small, and the spacing between the parts of the two lead-out rods outside the insulating assembly is larger than the spacing inside the insulating assembly.

[0008] Furthermore, two grooves are arranged at the end of the metal outer tube, and a groove is arranged at the center of the insulating medium of the insulating assembly component close to one end of the metal outer tube.

[0009] Furthermore, the insulating medium is a ceramic material, and the insulating material is in powder form.

[0010] Furthermore, the insulating assembly component is made of insulating material with a high relative dielectric constant.

[0011] Furthermore, the insulating assembly component and the metal outer tube are connected by insulating glue.

[0012] Furthermore, the lead-out rod in the insulating assembly component and the part away from the insulating assembly component and in the air are both coated with an insulating layer, and the lead-out rod near the electric heating wire has no insulating layer.

[0013] The beneficial effects of the present invention are as follows:

[0014] 1. The double-ended high-voltage heating tube end sealing structure described in the present invention meets the requirements of electrical clearance under high voltage conditions. The insulating medium used is an insulating material with high dielectric strength. The insulating assembly component has a certain angle inside to expand the distance between the two lead rods, and an insulating material is arranged outside the lead rod. When the lead rod is in the air, the electrical clearance requirements can still be met. At the same time, the creepage requirements under high voltage conditions are met. The difficulty of process preparation is reduced, and the assembly components can be prepared separately. At the same time, the power distribution cost of the electric heater system is saved, and the comprehensive electric heat conversion efficiency of the system is improved.

[0015] 2. The double-ended high-voltage heating tube end sealing structure described in the present invention increases the distance between the two lead-out rods at the end by using an insulating assembly component to increase the electrical gap between the two lead-out rods. The part of the lead-out rod extending out of the insulating assembly component and the internal part of the insulating assembly component are sprayed with an insulating layer to avoid exposed parts in the air, thereby meeting the requirements of electrical safety distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the cross-sectional structure of the end of the electric heating tube in the present invention;

[0018] Figure 2 It is a schematic diagram of the cross-sectional structure of the double-ended electric heating tube in the present invention.

[0019] In the figure: 1. Insulation layer; 2. Lead rod; 3. Insulation assembly component; 4. Insulation medium; 5. Metal outer tube; 6. Electric heating wire; 7. Insulation material; 8. Electric heating tube. DETAILED DESCRIPTION

[0020] 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.

[0021] like Figure 1 to Figure 2 As shown, a double-end high-voltage heating tube end sealing structure according to an embodiment of the present invention comprises an electric heating tube 8, which is composed of a metal outer tube 5, an electric heating wire 6 and a lead-out rod 2; two symmetrically arranged electric heating wires 6 and two symmetrically arranged lead-out rods 2 are installed in the electric heating tube 8, the electric heating wires 6 are connected to the lead-out rods 2, an insulating assembly component 3 is arranged outside the lead-out rod 2, an insulating medium 4 is filled between the electric heating wire 6 and the metal outer tube 5, an insulating material 7 is filled between the insulating medium 4 and the electric heating wire 6, and the cross section of the metal outer tube 5 is in a "U" shape. The side surfaces of the two lead-out rods 2 are stepped, the spacing between the two lead-out rods 2 in the insulating assembly component 3 is small, and the spacing between the two lead-out rods 2 outside the insulating assembly component 3 is larger than the spacing in the insulating assembly component 3. Two grooves are arranged at the end of the metal outer tube 5, and a groove is opened at the insulating assembly component 3 near the center of the insulating medium 4.

[0022] Specifically, the insulating medium 4 is a ceramic material, and the insulating material 7 is in powder form. The insulating assembly component 3 is made of an insulating material with a high relative dielectric constant. The insulating assembly component 3 and the metal outer tube 5 are connected by insulating glue. The lead-out rod 2 in the insulating assembly component 3 and the part away from the insulating assembly component 3 and in the air are both coated with an insulating layer 1, and the lead-out rod 2 near the electric heating wire 6 has no insulating layer 1.

[0023] During operation, the insulating assembly component 3 increases the distance between the two lead rods 2 at the end, thereby increasing the electrical clearance between the two lead rods 2. The part of the lead rod 2 extending out of the insulating assembly component 3 and the internal part of the insulating assembly component 3 are sprayed with an insulating layer 1 to avoid the exposed part in the air, thereby meeting the requirements of the electrical safety distance. The insulating assembly component 3 is connected to the insulating medium 4 using a concave-convex structure, and the connection is filled with a sealant. The concave-convex structure increases the creepage distance between the lead rods 2 and between the lead rod 2 and the metal outer tube 5. The sealant is used to take into account the generation of air gaps between the connection sections, which affects the service life of the electric heating tube 8. After the electric heating tube 8 is assembled, the insulating assembly component 3 is higher than the metal outer tube 5, which reduces the difficulty of the manufacturing process on the one hand, and increases the creepage distance on the other hand.

[0024] The present application meets the requirements of electrical clearance under high voltage conditions. The insulating medium 4 used in the present application is made of insulating material with high dielectric strength. The inside of the insulating assembly component 3 has a certain angle to expand the distance between the two lead rods 2, and an insulating material 7 is arranged outside the lead rod 2. When the lead rod 2 is in the air, the requirements of electrical clearance can still be met. At the same time, the creepage requirements under high voltage conditions are met. The difficulty of process preparation is reduced, and the assembly components can be prepared separately. At the same time, compared with low-voltage electric heaters, the power distribution cost of the electric heater system is saved, and the comprehensive electric heat conversion efficiency of the system is improved.

[0025] Working principle: The insulating assembly component 3 increases the distance between the two lead-out rods 2 at the end, thereby increasing the electrical clearance between the two lead-out rods 2. The part of the lead-out rod 2 extending from the insulating assembly component 3 and the internal part of the insulating assembly component 3 are sprayed with an insulating layer 1 to avoid exposure to the air and meet the requirements of electrical safety distance. The insulating assembly component 3 and the insulating medium 4 are connected with a concave-convex structure, and the connection is filled with sealant. The concave-convex structure increases the creepage distance between the lead-out rods 2 and between the lead-out rod 2 and the metal outer tube 5. The sealant is used to take into account the generation of air gaps between the connection sections, which affects the service life of the electric heating tube 8. After the electric heating tube 8 is assembled, the insulating assembly component 3 is higher than the metal outer tube 5, which reduces the difficulty of the manufacturing process on the one hand and increases the creepage distance on the other hand.

[0026] 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.

[0027] 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.

[0028] 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 double-ended high-voltage heating tube end sealing structure, characterized in that: It comprises an electric heating tube (8), wherein the electric heating tube (8) is composed of a metal outer tube (5), an electric heating wire (6) and a lead-out rod (2); The electric heating tube (8) is provided with two symmetrically arranged electric heating wires (6) and two symmetrically arranged lead-out rods (2); the electric heating wires (6) are connected to the lead-out rods (2); an insulating assembly component (3) is arranged outside the lead-out rods (2); an insulating medium (4) is filled between the electric heating wires (6) and the metal outer tube (5); an insulating material (7) is filled between the insulating medium (4) and the electric heating wires (6); and the cross section of the metal outer tube (5) is in a "U" shape.

2. A double-ended high-voltage heating tube end sealing structure according to claim 1, characterized in that: The side surfaces of the two lead-out rods (2) are in a stepped shape; the spacing between the parts of the two lead-out rods (2) inside the insulating assembly component (3) is smaller, and the spacing between the parts of the two lead-out rods (2) outside the insulating assembly component (3) is larger than the spacing inside the insulating assembly component (3).

3. The double-ended high-voltage heating tube end sealing structure according to claim 1, characterized in that: Two grooves are arranged at the end of the metal outer tube (5), and a groove is arranged at the center of one end of the metal outer tube (5) of the insulating assembly component (3).

4. The double-ended high-voltage heating tube end sealing structure according to claim 1, characterized in that: The insulating medium (4) is a ceramic material, and the insulating material (7) is in powder form.

5. The double-ended high-voltage heating tube end sealing structure according to claim 1, characterized in that: The insulating assembly component (3) is made of insulating material with a high relative dielectric constant.

6. A double-ended high-voltage heating tube end sealing structure according to claim 1, characterized in that: The insulating assembly component (3) and the metal outer tube (5) are connected via insulating glue.

7. The double-ended high-voltage heating tube end sealing structure according to claim 1, characterized in that: The lead-out rod (2) is coated with an insulating layer (1) both in the insulating assembly component (3) and in the air away from the insulating assembly component (3), and the lead-out rod (2) is not coated with an insulating layer (1) near the electric heating wire (6).

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