Header end cover hot wire welding preheating and full-time temperature monitoring device

Abstract

The utility model relates to a header end cover hot wire welding preheating and full-time temperature monitoring device which comprises a first roller carrier and a second roller carrier, the first roller carrier and the second roller carrier are both perpendicular to the ground, and a header end cover to be welded is placed on the side, away from the ground, of the first roller carrier and the side, away from the ground, of the second roller carrier. A clamping jaw is arranged on the side close to the first roller frame and clamped at one end of a header end cover to be welded, an adjusting support is arranged on one side of the second roller frame and perpendicular to the ground, and a preheating device is arranged at the end, away from the ground, of the adjusting support. One end of the header end cover to be welded extends into the preheating device, the other end of the header end cover to be welded extends into the preheating device, a thermocouple is contained in the preheating device, the thermocouple is attached to the surface of the header end cover to be welded, and the thermocouple is externally connected with a temperature controller. The header end cover hot wire TIG welding temperature monitoring device overcomes the defect that a traditional header end cover hot wire TIG welding temperature monitoring device is insufficient in monitoring force.

Description

Technical Field

[0001] The present application relates to the technical field of welding equipment, and in particular to a device for preheating and full-time temperature monitoring of hot wire welding of a header end cover. Background Art

[0002] In order to improve boiler efficiency, drum boilers gradually developed into tubular boilers to increase the heat transfer area. The boiler water flows from the drum through the downcomer into the box below, and is distributed to each tube bundle by the box. The water in these tube bundles continuously absorbs heat energy, gathers in the box above, and then flows back into the drum. We call the upper and lower boxes headers or headers. The header (also called header) is an important part of the boiler, which is divided into upper header and lower header.

[0003] Traditional hot wire TIG welding of header end covers requires torches throughout the welding process, without any insulation measures, and the rapid heat dissipation causes a large amount of energy waste. Open flame heating around welding equipment poses a safety hazard, especially for cables. Local preheating leads to uneven temperatures in the weld and surrounding areas, which is not conducive to weld quality control. For the measurement of preheating temperature, manual temperature measurement with a thermometer is difficult to ensure accuracy. No relevant temperature data is left in the entire process, and only occasional spot checks can ensure that the temperature of the entire welding process meets the requirements. For this reason, it is necessary to propose a header end cover hot wire welding preheating and full-time temperature monitoring device in response to the defect of insufficient monitoring power of the traditional header end cover hot wire TIG welding temperature monitoring device. Utility Model Content

[0004] Based on this, it is necessary to propose a preheating and full-time temperature monitoring device for hot wire TIG welding of header end cover to address the defect of insufficient monitoring power of the traditional temperature monitoring device for hot wire TIG welding of header end cover.

[0005] The present application provides a hot wire welding preheating and full-time temperature monitoring device for a header end cover, comprising a first roller frame and a second roller frame, the first roller frame and the second roller frame are both perpendicular to the ground, the header end cover to be welded is placed on the side of the first roller frame and the second roller frame away from the ground, a clamping claw is provided on the side close to the first roller frame, the clamping claw is clamped on one end of the header end cover to be welded, an adjusting bracket is provided on one side of the second roller frame, the adjusting bracket is perpendicular to the ground, a preheating device is provided on the end of the adjusting bracket away from the ground, the other end of the header end cover to be welded extends into the preheating device, the preheating device accommodates a thermocouple, the thermocouple is attached to the surface of the header end cover to be welded, and the thermocouple is externally connected to a temperature controller.

[0006] In one embodiment, the preheating device comprises a steel shell, the outer shape of the steel shell is a cylinder, one end of the steel shell is sealed, and the other end of the steel shell extends into the header end cover to be welded.

[0007] In one embodiment, the preheating device further comprises a thermal insulation layer, and the thermal insulation layer surrounds the inner wall of the steel shell.

[0008] In one embodiment, the preheating device further includes an electric heater, and the electric heater surrounds the inner wall of the insulation layer.

[0009] In one embodiment, the straight-line distance of the gap between the electric heater and the header end cover to be welded is greater than or equal to one twentieth of the inner diameter of the steel shell and less than or equal to one tenth of the inner diameter of the steel shell.

[0010] In one embodiment, the preheating device is provided with a circular through hole, and the circular through hole sequentially passes through the steel shell, the thermal insulation layer and the electric heater.

[0011] In one embodiment, the axial center axis of the circular through hole is perpendicular to the ground.

[0012] In one embodiment, an extension line of the axial center axis of the round through hole is perpendicular to and intersects with an extension line of the axial center axis of the steel shell.

[0013] In one embodiment, the position of the round through hole is the conducting portion between the welding device and the header end cover to be welded.

[0014] In one embodiment, the thermocouple is in abutting contact with the header end cover to be welded.

[0015] Technical advantages of this application:

[0016] 1. The preheating device evenly heats the area around the welding groove directly at the welding station, greatly reducing heat dissipation. Specifically, the steel shell is wrapped around the insulation layer and the outer side of the electric heater. The electric heater evenly heats the area around the welding groove directly. The insulation layer greatly reduces heat dissipation.

[0017] 2. Add a temperature control couple to the temperature controller connected to the thermocouple (near the 100mm range boundary on both sides of the groove according to the specification) to measure the temperature close to the barrel surface in real time. The temperature controller accurately controls the heating and automatically records the temperature curve all the time.

[0018] 3. Adjust the bracket so that the furnace bracket height can be adjusted according to the header specifications to adapt to different welding heights or header specifications.

[0019] 4. The clamping jaws, the first roller frame and the second roller frame enable the header end cover to be welded to roll during the processing, ensuring that the welding device welds the header end cover to be welded evenly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of this application are used to provide a further understanding of this application, so that other features, purposes and advantages of this application become more obvious. The illustrative embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation on this application.

[0021] Figure 1 A schematic structural diagram of a header end cover hot wire welding preheating and full-time temperature monitoring device provided in one embodiment of the present application.

[0022] Figure 2 A schematic structural diagram of a header end cover hot wire welding preheating and full-time temperature monitoring device provided in yet another embodiment of the present application.

[0023] Figure 3 A schematic diagram of the structure of the clamping jaws of a header end cover hot wire welding preheating and full-time temperature monitoring device provided in one embodiment of the present application.

[0024] Figure 4 A schematic structural diagram of a roller frame of a header end cover hot wire welding preheating and full-time temperature monitoring device provided in one embodiment of the present application.

[0025] Figure 5 A schematic diagram of the structure of a thermocouple of a header end cover hot wire welding preheating and full-time temperature monitoring device provided in one embodiment of the present application.

[0026] Reference numerals: first roller frame 1 ; second roller frame 2 , clamping jaws 3 , adjusting bracket 4 , preheating device 5 , steel shell 51 , thermal insulation layer 52 , electric heater 53 , round through hole 54 , thermocouple 6 . DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] The present application provides a device for preheating and full-time temperature monitoring of hot wire welding of a header end cover.

[0029] like Figures 1 to 5As shown, in one embodiment of the present application, a hot wire welding preheating and full-time temperature monitoring device for a header end cover comprises a first roller frame 1 and a second roller frame 2, wherein the first roller frame 1 and the second roller frame 2 are both perpendicular to the ground, and the header end cover to be welded is placed on the side of the first roller frame 1 and the second roller frame 2 away from the ground, and a clamping jaw 3 is provided on the side close to the first roller frame 1, and the clamping jaw 3 is clamped on one end of the header end cover to be welded, and an adjusting bracket 4 is provided on one side of the second roller frame 2, and the adjusting bracket 4 is perpendicular to the ground, and a preheating device 5 is provided on the end of the adjusting bracket 4 away from the ground, and the other end of the header end cover to be welded extends into the preheating device 5, and the preheating device 5 accommodates a thermocouple 6, and the thermocouple 6 is attached to the surface of the header end cover to be welded, and the thermocouple 6 is externally connected to a temperature controller.

[0030] The preheating device 5 comprises a steel shell 51 , the outer shape of the steel shell 51 is a cylinder, one end of the steel shell 51 is sealed, and one end of the steel shell 51 extends into the header end cover to be welded.

[0031] The preheating device 5 further includes a heat-insulating layer 52 , and the heat-insulating layer 52 surrounds the inner wall of the steel shell 51 .

[0032] The preheating device 5 further includes an electric heater 53 , and the electric heater 53 surrounds the inner wall of the thermal insulation layer 52 .

[0033] Specifically, TIG welding (Tungsten Inert Gas Welding) is also known as non-melting electrode inert gas shielded arc welding. Whether it is manual welding or automatic welding of 0.5 to 4.0 mm thick stainless steel, TIG welding is the most commonly used welding method. TIG welding with filler wire is often used for base welding of pressure vessels because TIG welding has better air tightness and can reduce the porosity of the weld during pressure vessel welding. The heat source of TIG welding is a DC arc with an operating voltage of 10 to 95 volts, but the current can reach 600 amps. The correct connection method of the welding machine is that the workpiece is connected to the positive pole of the power supply, and the tungsten electrode in the welding torch is used as the negative pole. The inert gas is generally argon.

[0034] The welding process is that inert gas is fed through the welding torch to form a shield around the arc and on the welding pool. In order to increase the heat input, 5% hydrogen is generally added to the argon. However, when welding ferritic stainless steel, hydrogen cannot be added to the argon. The gas consumption is about 3 to 8 liters per minute. In addition to blowing inert gas from the welding torch during the welding process, it is best to blow gas from under the weld to protect the back of the weld.

[0035] It can be seen that temperature is a more important influencing parameter for TIG welding.

[0036] It is worth mentioning that the thoriated tungsten electrodes used in argon arc welding and plasma arc welding contain 1-1.2% thorium oxide. Thorium is a radioactive substance and is affected by radiation during the welding process and in contact with the thoriated tungsten rod.

[0037] Radiation acts on the human body in two forms: one is external irradiation, and the other is internal irradiation through the respiratory and digestive systems. A large number of investigations and measurements on argon arc welding and plasma arc welding have shown that their radioactive hazards are relatively small, because only 100-200 mg of thorium tungsten poles are consumed every day, and the radiation dose is extremely small, which has little effect on the human body.

[0038] There are two situations that must be paid attention to: First, when welding in a container, the ventilation is poor and the radioactive particles in the smoke may exceed the health standards; second, when grinding thoriated tungsten rods and in places where thoriated tungsten rods exist, the concentration of radioactive aerosols and radioactive dust may reach or even exceed the health standards.

[0039] Radioactive substances invading the body can cause chronic radiation sickness, which is mainly manifested in a weakening of general functional status, obvious weakness, significantly reduced resistance to infectious diseases, weight loss and other symptoms.

[0040] Therefore, when performing welding tasks, the steel shell 51 can have a certain radiation protection effect.

[0041] This embodiment relates to a hot wire welding preheating and full-time temperature monitoring device for a header end cover. The preheating device 5 directly and evenly heats the area around the welding groove at the welding station, greatly reducing heat dissipation. Specifically, the steel shell 51 is wrapped around the outer side of the insulation layer 52 and the electric heater 53. The electric heater 53 directly and evenly heats the area around the welding groove. The insulation layer 52 greatly reduces heat dissipation.

[0042] like Figures 1 to 5 As shown, in one embodiment of the present application, the straight-line distance of the gap between the electric heater 53 and the header end cover to be welded is greater than or equal to one twentieth of the inner diameter of the steel shell 51 and less than or equal to one tenth of the inner diameter of the steel shell 51.

[0043] Specifically, due to the great influence of temperature on welding, it is specifically reflected in:

[0044] When welding aluminum, magnesium and other metals with AC, the electron emission capabilities of the tungsten electrode and the workpieces are different. The tungsten electrode has a stronger ability to emit electrons when used as a cathode. The emission capabilities of the processed objects are different at different temperatures. In the positive half cycle, the tungsten electrode acts as a cathode, and the number of electrons in the arc space increases, making it easy to conduct electricity, which is equivalent to a decrease in the equivalent resistance of the arc. Therefore, under the same power supply, the arc current increases; on the contrary, in the negative half cycle, the arc current is relatively small. Since the currents in the two half cycles are asymmetric, the current of the AC arc can be regarded as consisting of two parts, one is direct current, and the other is direct current superimposed on the AC part. This part of the DC current is called the DC component, and its direction is the same as the current direction in the positive half cycle, flowing from the base material to the tungsten electrode. This phenomenon of generating a DC component in the AC arc is called the "rectification effect" of tungsten electrode AC argon arc welding. Generally, the greater the difference in the physical properties of the two electrode materials, the greater the DC component. The appearance of the DC component will weaken the cathode fragmentation effect and affect the normal operation of the welding transformer, so it is necessary to eliminate the DC component.

[0045] Inserting a reverse polarity battery and an isolation capacitor in series in the welding circuit can eliminate the DC component. The direction of the current generated by the battery is opposite to the DC component, and the capacitor only allows AC to pass but not DC. In terms of arc stabilization, a high-frequency oscillator is used to stabilize the arc or a high-voltage pulse is used to start and stabilize the arc.

[0046] Therefore, the linear distance of the gap between the electric heater 53 and the header end cover to be welded needs to be adjusted according to different working media.

[0047] The preheating device 5 is provided with a round through hole 54, and the round through hole 54 sequentially penetrates the steel shell 51, the insulation layer 52 and the electric heater 53. The thermocouple 6 is in abutment contact with the header end cover to be welded.

[0048] The axial center axis of the circular through hole 54 is perpendicular to the ground. The extension line of the axial center axis of the circular through hole 54 is perpendicular to and intersects with the extension line of the axial center axis of the steel shell 51 .

[0049] The position of the circular through hole 54 is the conducting portion between the welding device and the header end cover to be welded.

[0050] This embodiment relates to a preheating and full-time temperature monitoring device for hot wire welding of header end cover. Thermocouple 6 and external temperature controller are added with temperature control electric couples (near the 100mm range boundary on both sides of the groove according to the specification) to measure the temperature close to the surface of the barrel in real time. The temperature controller accurately controls the heating and automatically records the temperature curve all the time.

[0051] The adjusting bracket 4 allows the furnace bracket height to be adjusted according to the header specifications, and is adapted to different welding heights or header specifications. The clamping jaws 3, the first roller frame 1 and the second roller frame 2 enable the header end cover to be welded to roll during the processing, ensuring that the welding device welds the header end cover to be welded uniformly.

[0052] The technical features of the above-described embodiments may be arbitrarily combined, and the execution order of the method steps is not limited. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A device for preheating and full-time temperature monitoring of hot wire welding of header end cover, characterized in that: The invention comprises a first roller frame (1) and a second roller frame (2), wherein the first roller frame (1) and the second roller frame (2) are both perpendicular to the ground, a header end cover to be welded is placed on the side of the first roller frame (1) and the second roller frame (2) away from the ground, a clamping claw (3) is provided on the side close to the first roller frame (1), and the clamping claw (3) is clamped on one end of the header end cover to be welded, and an adjustment bracket (4) is provided on one side of the second roller frame (2), and the adjustment bracket (4) is perpendicular to the ground; A preheating device (5) is provided at one end of the adjusting bracket (4) away from the ground, and the other end of the header end cover to be welded extends into the preheating device (5). The preheating device (5) accommodates a thermocouple (6), and the thermocouple (6) is attached to the surface of the header end cover to be welded. The thermocouple (6) is externally connected to a temperature controller.

2. The header end cover hot wire welding preheating and full-time temperature monitoring device according to claim 1 is characterized in that: The preheating device (5) comprises a steel shell (51) having a cylindrical shape, one end of the steel shell (51) being sealed, and one end of the steel shell (51) extending into a header end cover to be welded.

3. The device for preheating and full-time temperature monitoring of hot wire welding of header end cover according to claim 2 is characterized in that: The preheating device (5) further comprises a heat-insulating layer (52), wherein the heat-insulating layer (52) surrounds the inner wall of the steel outer shell (51).

4. The device for preheating and full-time temperature monitoring of hot wire welding of header end cover according to claim 3 is characterized in that: The preheating device (5) further comprises an electric heater (53), wherein the electric heater (53) surrounds the inner wall of the thermal insulation layer (52).

5. The device for preheating and full-time temperature monitoring of hot wire welding of header end cover according to claim 4, characterized in that: The straight-line distance of the gap between the electric heater (53) and the header end cover to be welded is greater than or equal to one twentieth of the inner diameter of the steel shell (51) and less than or equal to one tenth of the inner diameter of the steel shell (51).

6. The device for preheating and full-time temperature monitoring of hot wire welding of header end cover according to claim 5, characterized in that: The preheating device (5) is provided with a round through hole (54), and the round through hole (54) sequentially penetrates the steel shell (51), the thermal insulation layer (52) and the electric heater (53).

7. The device for preheating and full-time temperature monitoring of hot wire welding of header end cover according to claim 6, characterized in that: The axial center axis of the circular through hole (54) is perpendicular to the ground.

8. The device for preheating and full-time temperature monitoring of hot wire welding of header end cover according to claim 7, characterized in that: An extension line of the axial center axis of the circular through hole (54) is perpendicular to and intersects with an extension line of the axial center axis of the steel shell (51).

9. The device for preheating and full-time temperature monitoring of hot wire welding of header end cover according to claim 8, characterized in that: The position of the round through hole (54) is the conducting portion between the welding device and the header end cover to be welded.

10. The header end cover hot wire welding preheating and full-time temperature monitoring device according to claim 9, characterized in that: The thermocouple (6) is in abutment contact with the header end cover to be welded.

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