Low-frequency electromagnetic heater

Abstract

The utility model provides a low-frequency electromagnetic heater. The low-frequency electromagnetic heater comprises a heating unit and a controller, the heating unit comprises an outer cover, a coil, insulating cloth and a supporting rod; the outer cover is provided with an accommodating space; the coil comprises a coil body fixed in the containing space and two connector lugs which penetrate through the outer cover from the two ends of the coil body and extend out of the containing space. The insulating cloth covers and is fixed on the outer cover and encapsulates the coil in the accommodating space; the supporting rods are made of a material without a metal induction phenomenon, are parallel to the width direction of the insulating cloth, are arranged at intervals along the length direction of the insulating cloth and are fixed on one side, far away from the coil, of the insulating cloth; the controller is used for supplying power to the heating unit, the output end of the controller is connected to the two connector lugs through two power lines, and the input end of the controller is connected with the plug through a power line. Compared with the prior art, the low-frequency electromagnetic heater is high in operation efficiency, good in effect and high in safety.

Description

Technical Field

[0001] This utility model relates to the technical field of heating devices, and more particularly to a low-frequency electromagnetic heater for removing the anti-corrosion layer of metal pipes. Background Technology

[0002] Pipelines for transporting water, gas, and oil are generally buried underground and are mostly made of metal, such as steel. To prevent corrosion from soil, moisture, microorganisms, and other corrosive factors in the buried environment and thus extend the service life of the metal pipelines, a three-layer polyethylene anti-corrosion layer, or 3PE layer, is usually coated on the surface of the metal pipeline. From the inside out, it includes an epoxy powder coating, an adhesive layer, and an extruded polyethylene layer. The layers are tightly bonded together to form a composite structure with excellent anti-corrosion protection performance.

[0003] In actual construction, it is often necessary to remove the polyethylene anti-corrosion layer at the ends or specific parts of metal pipes to meet the technical requirements of construction and installation. In existing technologies, based on the physicochemical properties of the polyethylene anti-corrosion layer on metal pipes, the surface of the polyethylene anti-corrosion layer is typically softened by flame heating, and then the polyethylene layer is cut, peeled, and extruded using tools to achieve the removal purpose. This method requires liquefied petroleum gas (LPG) as an energy source, necessitating the carrying of LPG cylinders, heating guns, and other equipment during on-site operation. The removal efficiency is low, and uneven heating leads to poor results; furthermore, the operation poses certain safety risks.

[0004] Therefore, it is necessary to provide a new low-frequency electromagnetic heater to solve the above problems. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a low-frequency electromagnetic heater that is both highly efficient and safe.

[0006] To solve the above-mentioned technical problems, this utility model provides a low-frequency electromagnetic heater, comprising:

[0007] A heating unit, comprising an outer casing, a coil, an insulating cloth, and support rods; the outer casing is made of a flexible material and has a rectangular structure with a receiving space; the coil includes a coil body wound with electromagnetic induction wire in a racetrack-shaped structure and two terminals extending from both ends of the coil body through the outer casing to the outside of the receiving space, the coil body being housed and fixed within the receiving space; the insulating cloth is made of an insulating material and is covered and fixed to the outer casing, encapsulating the coil within the receiving space; the support rods are made of a material without metallic induction, and include multiple rods, all parallel to the width direction of the insulating cloth, the multiple support rods being spaced apart along the length direction of the insulating cloth and fixed to the side of the insulating cloth away from the coil; and...

[0008] The controller is used to supply power to the heating unit. The output of the controller is connected to the two terminals respectively via two power lines, and the input of the controller is connected to the plug via a power line.

[0009] Preferably, the outer cover includes a rectangular bottom wall and side walls that bend upward from the periphery of the bottom wall, and the periphery of the insulating cloth is attached and fixed to the periphery of the bottom wall.

[0010] Preferably, the sidewall is formed by a plurality of independent sidewall blocks arranged in sequence.

[0011] Preferably, both ends of each support rod are fixed to the corresponding side wall block.

[0012] Preferably, the outer cover is made of carbon fiber material.

[0013] Preferably, the support rod is made of aluminum-magnesium alloy.

[0014] Preferably, the thickness of both the bottom wall and the side wall is 1 mm.

[0015] Preferably, the electromagnetic induction wire is a mica wire with a cross-section of 10 square millimeters.

[0016] Preferably, the low-frequency electromagnetic heater further includes a latch and a lock head, which are respectively fixed to opposite ends of the bottom wall along its length and located on the side of the bottom wall away from the coil.

[0017] Compared to existing technologies, the low-frequency electromagnetic heater of this invention, when used, involves placing the heating unit around a designated location on the steel pipe coated with a polyethylene anti-corrosion layer to be removed. The coil is energized via a controller, and the steel pipe, encased in the polyethylene anti-corrosion layer, is heated using the principle of electromagnetic induction. When the steel pipe reaches a predetermined temperature, the heat is transferred to the adhesive layer of the polyethylene anti-corrosion layer, causing it to melt. This allows the epoxy powder coating of the polyethylene anti-corrosion layer to detach from the extruded polyethylene layer. The heating unit can then be removed, and the extruded polyethylene layer can be cut open with a utility knife to remove it. This method is not only highly efficient but also produces excellent removal results. Furthermore, the low-frequency electromagnetic heater has a simple structure and small size, eliminating the need to carry liquefied petroleum gas cylinders; only an industrial portable power supply is required, resulting in higher safety. Attached Figure Description

[0018] Figure 1 A partial structural schematic diagram of the heating unit provided for an embodiment of the low-frequency electromagnetic heater of this utility model;

[0019] Figure 2 This is a schematic diagram illustrating the application scenario of the low-frequency electromagnetic heater of this utility model. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Please refer to Figure 1-2 As shown, this utility model provides a low-frequency electromagnetic heater 100, including a heating unit 1 and a controller 2.

[0022] The heating unit 1 includes an outer cover 11, a coil 12, an insulating cloth 13, and a support rod 14.

[0023] The outer cover 11 is made of a flexible material and has a rectangular structure with a receiving space. In this embodiment, the outer cover 11 is made of carbon fiber material, which not only has sufficient strength and is not easily damaged during use, but also has good toughness, can be bent according to different pipe diameters, reduces the impact of limited space, is convenient to use and has strong applicability. In addition, it is resistant to high temperature and has good insulation properties, making it safer to use.

[0024] The coil 12 includes a coil body 121 wound with electromagnetic induction wire in a racetrack-shaped structure and two terminals (not shown) that pass through the outer cover 11 from both ends of the coil body 121 and extend to the outside of the receiving space. The coil body 121 is housed and fixed in the receiving space.

[0025] The insulating cloth 13 is made of insulating material, and the insulating cloth 13 covers and fixes the outer cover 1 and encapsulates the coil 12 in the receiving space.

[0026] The support rod 14 is made of a material that does not exhibit metallic induction. The support rod 14 comprises multiple rods, all of which are parallel to the width direction of the insulating cloth 13. The multiple support rods 14 are arranged at intervals along the length direction of the insulating cloth 13 and fixed to the side of the insulating cloth 13 away from the coil 12.

[0027] In this embodiment, the support rod 14 is made of aluminum-magnesium alloy. This aluminum-magnesium alloy metal has no induction phenomenon, will not be heated, and effectively ensures that the induction distance between the coil 12 and the steel pipe is controlled at about 20mm, resulting in high electromagnetic induction efficiency.

[0028] In this embodiment, the outer cover 11 includes a rectangular bottom wall 111 and a side wall 112 that bends upward from the periphery of the bottom wall 111, and the periphery of the insulating cloth 13 is attached and fixed to the periphery of the bottom wall 111.

[0029] In order to make it easier to bend the heating unit 1 according to different steel pipe diameters, in this embodiment, the side wall 112 is formed by a plurality of independent side wall blocks arranged in sequence.

[0030] Each of the support rods 14 has its two ends fixed to the corresponding side wall block. This does not affect the bending of the side wall 112, but also better supports the overall heating unit 1, ensuring it unfolds flat without deformation and providing better and more uniform heating.

[0031] The controller 2 is used to supply power to the heating unit 1. The output terminal of the controller 2 is connected to the two terminals respectively through two power lines, and the input terminal of the controller 2 is connected to the plug through a power line.

[0032] In this embodiment, the controller 2 uses a 220V power supply with a rated power of 5KW and a frequency of 50-500Hz (low frequency). It is equipped with a current transformer connection, a DSP high-speed operating controller that can be digitally programmed, a half-bridge IGBT module main circuit structure, load temperature detection and protection, an aluminum alloy heat sink, and other common structures.

[0033] In this embodiment, the thickness of both the bottom wall 111 and the side wall 112 is 1 mm. The electromagnetic induction wire is a mica wire with a cross-section of 10 square millimeters.

[0034] To further improve heating efficiency, in this embodiment, the low-frequency electromagnetic heater 100 also includes a latch 3 and a lock head 4. The latch 3 and the lock head 4 are respectively fixed to opposite ends of the bottom wall 111 along its length direction and are located on the side of the bottom wall 111 away from the coil 12. After the heating unit 1 is wrapped around the steel pipe, it is quickly fixed by the cooperation of the latch 3 and the lock head 4.

[0035] The low-frequency electromagnetic heater 100 of this invention heats through electromagnetic induction, converting electrical energy into heat energy. This is a non-contact heating method, eliminating the need for direct contact between the heating element (heating unit 1) and the object being heated (steel pipe 10), thus avoiding problems such as friction, contamination, and loss. It features high heating efficiency and good controllability. The induced current can be evenly distributed within the object, achieving a rapid and uniform heating effect. The separation layer structure is effective, resulting in better removal. Furthermore, the heating temperature, range, depth, and other parameters can be controlled by adjusting the current through the controller 2 as needed.

[0036] In use, the polyethylene anti-corrosion layer 20 on the outer periphery of the steel pipe 10 consists of 3 layers: the bottom layer is an epoxy powder coating 201, the middle layer is an adhesive layer 202, and the outer layer is a polyethylene layer 203. The melting temperature of the middle layer is 105℃. When electromagnetic heating is used to utilize its properties, the internal steel pipe 10 is heated to 200℃. Heat is conducted through the steel pipe 10 to melt the adhesive layer 202, so that the epoxy powder coating 201 separates from the polyethylene layer 203. Then, the heating unit 1 is removed, and the polyethylene layer 203 is immediately peeled off after being cut open with a utility knife.

[0037] Compared to existing technologies, the low-frequency electromagnetic heater of this invention, when used, involves placing the heating unit around a designated location on the steel pipe coated with a polyethylene anti-corrosion layer to be removed. The coil is energized via a controller, and the steel pipe, encased in the polyethylene anti-corrosion layer, is heated using the principle of electromagnetic induction. When the steel pipe reaches a predetermined temperature, the heat is transferred to the adhesive layer of the polyethylene anti-corrosion layer, causing it to melt. This allows the epoxy powder coating of the polyethylene anti-corrosion layer to detach from the extruded polyethylene layer. The heating unit can then be removed, and the extruded polyethylene layer can be cut open with a utility knife to remove it. This method is not only highly efficient but also produces excellent removal results. Furthermore, the low-frequency electromagnetic heater has a simple structure and small size, eliminating the need to carry liquefied petroleum gas cylinders; only an industrial portable power supply is required, resulting in higher safety.

[0038] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A low frequency electromagnetic heater, characterized in that, The utility model relates to a low-frequency electromagnetic heating device, which comprises a heating unit and a controller. The heating unit comprises an outer cover, a coil, an insulating cloth and a support rod. The outer cover is made of flexible material and has a rectangular structure with a receiving space.

2. The low frequency electromagnetic heater of claim 1, wherein, The coil comprises a coil body and two terminal heads.

3. The low frequency electromagnetic heater of claim 2, wherein, The coil body is made of electromagnetic induction wire and has a racetrack-shaped structure.

4. The low frequency electromagnetic heater of claim 3, wherein, The coil body is received and fixed in the receiving space.

5. The low frequency electromagnetic heater of claim 1 wherein, The insulating cloth is made of insulating material and covers and fixes the outer cover.

6. The low frequency electromagnetic heater of claim 1 wherein, The insulating cloth encapsulates the coil in the receiving space.

7. The low frequency electromagnetic heater of claim 2, wherein, The support rod is made of a material without metal induction phenomenon.

8. The low frequency electromagnetic heater of claim 1, wherein, The support rod comprises a plurality of rods parallel to the width direction of the insulating cloth.

9. The low frequency electromagnetic heater of claim 2, wherein, The plurality of rods are arranged along the length direction of the insulating cloth and fixed to the side of the insulating cloth away from the coil. The controller is used to power the heating unit. The output of the controller is connected to the two terminal heads through two power lines respectively. The input of the controller is connected to a power line through a plug. The outer cover comprises a bottom wall and a side wall. The periphery of the insulating cloth is fixed to the periphery of the bottom wall. The side wall is composed of a plurality of independent side wall blocks. The two ends of each support rod are fixed to the corresponding side wall block. The outer cover is made of carbon fiber material. The support rod is made of aluminum-magnesium alloy. The thickness of the bottom wall and the side wall is 1 mm. The electromagnetic induction wire is mica wire with a cross section of 10 square millimeters. The low-frequency electromagnetic heater further comprises a lock and a lock head. The lock and the lock head are fixed to the opposite ends of the bottom wall along the length direction and located on the side of the bottom wall away from the coil.

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