Shielding gas tool for welding heat exchange tube and tube plate

Abstract

The utility model provides a shielding gas tool for welding a heat exchange tube and a tube plate. The shielding gas tool comprises a copper tube, one end of the copper pipe is connected with the front blocking plate and the other end is connected with the rear blocking plate; the rear section of the rear blocking plate is provided with a protective gas pipe connector, and the front section of the rear blocking plate is provided with a tightening device. The screen is bundled and wrapped outside the copper pipe through steel wires; the copper pipe is provided with the first opening and the second opening, and the problem that the back face of a pipeline welding seam is not comprehensively protected by shielding gas is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of argon arc welding pipeline welding, in particular to a shielding gas tool for welding a heat exchange tube and a tube plate. Background Art

[0002] Heat exchangers are widely used in the chemical, petroleum, power, and refrigeration industries. They are essential equipment for ensuring the proper operation of industrial processes. In petrochemical plants, heat exchanger investment accounts for approximately 20% to 40% of total capital investment. Therefore, heat exchanger quality has a significant impact on industrial production. Due to the corrosion resistance of duplex stainless steel, heat exchanger tubes are made of duplex stainless steel to extend their service life. During heat exchanger production, strength welding of the tubes and tubesheets is required. Duplex stainless steel is easily oxidized and contaminated by air during welding. The increase in impurity gases can cause increased weld porosity, which in turn reduces weld quality. Therefore, a new duplex stainless steel welding technology, tungsten inert gas welding, is being adopted to improve weld quality, thereby enhancing the quality of the heat exchanger. This welding method utilizes arc heat generated between a tungsten electrode and the workpiece to melt the base metal and filler wire. During welding, shielding gas is continuously ejected from the nozzle of the welding gun, forming a gas protection layer around the arc to isolate the air and prevent its harmful effects on the tungsten electrode, molten pool and adjacent heat-affected zone, thereby obtaining high-quality welds.

[0003] In the actual welding process of duplex stainless steel heat exchange tubes and tube sheets, the outside of the weld is fully protected by using an integral argon protective cover or increasing the diameter of the argon nozzle. However, gas protection on the back of the weld is more difficult. In the existing technology, there is a method of directly introducing argon into the heat exchange tube, but this method consumes a large amount of argon, is costly, and the purity of the argon is not high, which affects the welding effect.

[0004] Therefore, a device is needed that can save costs and fully protect the back of the weld seam between the heat exchange tube and the tube sheet. Summary of the Invention

[0005] To address the aforementioned technical issues of high costs and the inability of argon gas to fully protect welds, a shielding gas fixture for welding heat exchange tubes to tubesheets is provided. This utility model primarily utilizes an additional screen to ensure more even distribution of the shielding gas. A tightening device is also added to ensure a more stable connection between the fixture and the heat exchange tubes. This modification significantly improves welding efficiency and weld pass rates, reduces argon gas consumption, and lowers welding costs.

[0006] The technical means adopted by this utility model are as follows:

[0007] A shielding gas tooling for welding heat exchange tubes and tube sheets comprises: a copper tube; one end of the copper tube is connected to a front plugging plate, and the other end of the copper tube is connected to a rear plugging plate; a shielding gas pipe interface is provided at the rear section of the rear plugging plate, and a tightening device is also provided on the rear plugging plate; a screen is wrapped around the outside of the copper tube by steel wire bundling; the copper tube is provided with a first opening and a second opening.

[0008] Furthermore, the front section of the front blocking plate is provided with a first chamfer, and the angle of the chamfer is 45°.

[0009] Furthermore, a second chamfer is provided at the front section of the rear blocking plate, and the angle of the chamfer is 45°.

[0010] Furthermore, the first opening and the second opening are tapered holes.

[0011] Furthermore, a first annular groove is provided on the front blocking plate.

[0012] Furthermore, a second annular groove is provided on the rear blocking plate.

[0013] Furthermore, the tightening device includes a right-angle copper bar, the bolt passes through the right-angle copper bar, and a rubber pad is fixed on the bolt.

[0014] During operation, the device is fixed to the joint of the protective gas pipe by welding, and the device is inserted into the required heat exchange tube. The device is fixed to the required welded heat exchange tube by adjusting the bolts on the tightening device.

[0015] The shielding gas enters through the shielding gas pipe interface provided on the rear blocking pipe, the front baffle and one end of the copper pipe are connected and fixed, and the other end of the copper pipe is welded and fixed to the rear blocking plate to form an air inlet chamber; the copper pipe is provided with multiple tapered holes, including a first opening and a second opening; and is transported to the heat exchange tube by using a screen bundled to the outside through a steel wire through the first annular groove and the second annular groove.

[0016] Compared with the prior art, the utility model has the following advantages:

[0017] 1) This device uses a front blocking plate, a copper tube, and a rear blocking plate to form an air inlet chamber, which greatly reduces the volume of the chamber, thereby reducing the time for filling argon gas and improving the purity of the argon gas in the chamber. This not only improves work efficiency and significantly reduces argon gas consumption; it also improves welding quality and reduces the possibility of weld oxidation;

[0018] 2) The shielding gas pipe of this device is evenly drilled on both sides and a screen is added to make the shielding gas more evenly distributed, ensuring that the gas flows out evenly and slowly, overcoming the vortex problem caused by traditional direct inflation, and can quickly discharge the air in the gas chamber, achieving the required argon purity in a short time;

[0019] 3) The device is provided with chamfers, making it easier to insert the heat exchange tube;

[0020] 4) This device is equipped with a tightening device, which is easy to operate, install and disassemble;

[0021] 5) This device is small in size, occupies little space, and will not affect the welding operation.

[0022] In summary, the application of the technical solution of the utility model can quickly achieve the required argon purity and fully protect the weld to improve the welding quality. Therefore, the technical solution of the utility model solves the problem of argon waste and incomplete weld protection in the welding process in the prior art.

[0023] Based on the above reasons, the utility model can be widely promoted in the fields of tungsten inert gas shielded welding of heat exchangers and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] Figure 1 This is a structural diagram of an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of screen bundling in an embodiment of the present invention;

[0027] Figure 3 Cross-sectional view of the first opening and the second opening of an embodiment of the present invention;

[0028] Figure 4 This is a schematic structural diagram of a tightening device according to an embodiment of the present invention;

[0029] In the figure: 1. Front blocking plate; 2. Copper tube; 3. Rear blocking plate; 4. Steel wire; 5. Screen; 6. Tightening device; 7. Protective gas pipe interface; 11. First chamfer; 12. First annular groove; 21. First opening; 22. Second opening; 31. Second chamfer; 32. Second annular groove; 61. Bolt; 62. Rubber pad; 63. Right-angle copper busbar. DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0033] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0034] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0035] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0036] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0037] like Figure 1-4 As shown, the utility model provides a shielding gas tool for welding heat exchange tubes and tube sheets, which is used for argon arc welding of heat exchange tubes and tube sheets. Manual welding of the tube sheets can be adopted. During welding, the utility model can realize gas protection on the inside of the fillet weld between the heat exchange tubes and tube sheets.

[0038] The device includes: a front blocking plate 1, a copper tube 2, a rear blocking plate 3, a steel wire 4, a screen 5, a tightening device 6, and a protective gas pipe interface 7;

[0039] One end of the copper tube 2 is fixed to the front blocking plate 1, and the other end is fixed to the rear blocking plate 3 to form a protective gas inlet chamber; the protective gas is transported to the air inlet chamber through the protective gas pipe interface 7 set on the rear blocking plate; wherein, the first opening 21 and the second opening 22 on the copper tube 2 are multiple conical holes, and the outside is used to use a steel wire 4 to tie and fix the screen 5 through the first annular groove 12 and the second annular groove 32; the protective gas in the air inlet pipe is transported to the heat exchange tube, so that the gas distribution is more even, overcoming the vortex problem caused by traditional direct inflation.

[0040] Among them, a first chamfer 11 and a second chamfer 31 are provided on the front blocking plate 1 and the rear blocking plate 3 on the side where the heat exchange tube enters, so that the device is easier to insert the heat exchange tube.

[0041] A tightening device 6 is also provided on the rear blocking plate 3, which helps to fix the device on the heat exchange tube to avoid position displacement caused by thermal stress generated by welding; it includes: bolts 61, rubber pads 62, and right-angle copper bars 63; among them, the bolts 61 pass through the right-angle copper bars 63 and can be pressure-adjusted; a rubber pad 62 is provided on the bolts 61 to increase the friction between the bolts 61 and the heat exchange tube.

[0042] In this embodiment, as a preference, the copper tube is Φ19*2; the steel wire is Φ0.8; the screen is GF2WO.125 / 0.09 (plain weave); the copper tube and the front blocking plate and the rear blocking plate are processed from an integral copper tube; the copper tube is made of red copper with good thermal conductivity; it can reduce the temperature during welding, reduce heat input, and accelerate the cooling of the temperature after welding, so that it can quickly leave the oxidation temperature.

[0043] By connecting the gas protection device of the present invention, positioning and gas protection effects can be achieved simultaneously when welding the fillet welds between the heat exchange tube and the tube sheet. The protective gas pipe interface 7 of the device determines the thread size and ventilation blind hole size that need to be processed in the core shaft connection section according to the connection part in the positioning tube of the tube sheet sealing machine. The front plugging plate 1, copper tube 2, rear plugging plate 3, steel wire 4, and screen 5 constitute the protective gas inlet chamber of the device in the heat exchange tube. The size of the protective gas inlet chamber is determined according to the inner diameter of the heat exchange tube. The overall outer diameter of the copper tube can be smaller than the inner diameter of the heat exchange tube by a certain size. For example, when the inner diameter of the heat exchange tube is 20 mm, the outer diameter of the positioning section can be selected as 19.5 mm. When using this device to weld a certain product, the welding quality of the heat exchange tube head is good.

[0044] The front ends of the front plugging plate 1 and the rear plugging plate 3 of this device are chamfered 1*45°. The chamfering is convenient for inserting the device into the heat exchange tube hole during the welding process. The rear plugging plate is provided with a tightening device. When the tooling is inserted into the heat exchange tube, the tooling is fixed to the heat exchange tube by rotating the bolts. In the tube sheet sealing and welding project, there are a large number of heat exchange tube holes. After each fillet weld between a heat exchange tube and the tube sheet, the positioning mandrel needs to be moved to another heat exchange tube hole. The front end of the heat exchange tube may have residual burrs due to grinding or other reasons, or the tube hole may be out of round. If the front end of the positioning mandrel is a solid cylinder, it may occasionally be impossible to insert it into the heat exchange tube hole. The chamfering of the front ends of the front plugging plate 1 and the rear plugging plate 3 can make it easier to insert the heat exchange tube into the heat exchange tube hole when positioning.

[0045] When the diameter of the heat exchange tube varies, the protection device in the above embodiment can select a specification suitable for the diameter of the heat exchange tube according to the diameter of the heat exchange tube, thereby achieving better back protection of the fillet weld between the heat exchange tube and the tube sheet.

[0046] During operation, the shielding gas tooling is welded and fixed to the shielding gas pipe joint, the front baffle 1 is connected and fixed to one end of the copper tube 2, and the other end of the copper tube 2 is welded and fixed to the rear plugging plate 3 to form an air inlet chamber; wherein, the copper tube 2 is provided with a plurality of conical holes, including a first opening 21 and a second opening 22; the rear plugging plate 3 is provided with a shielding gas pipe interface 7; so that argon gas enters the air inlet chamber through the shielding gas pipe interface 7, and is transported to the heat exchange tube through the plurality of conical holes provided on the copper tube 2, including the first opening 21 and the second opening 22, and the screen 5 tied to the outside through the steel wire 4 through the first annular groove 12 and the second annular groove 32. During the welding process of the heat exchange tube and the tube sheet, argon gas can be used to effectively isolate the weld from the outside air to avoid oxidation problems at the weld, thereby obtaining a weld with reliable quality and beautiful and uniform shape. Among them, the conical holes and screen make the protective gas more evenly distributed, ensuring that the gas flows out evenly and slowly, overcoming the vortex problem caused by traditional direct inflation; the front and rear blocking plates are chamfered to make the device easier to insert into the heat exchange tube; the front and rear blocking plates are provided with annular grooves to facilitate the bundling and fixation of steel wires; the tightening device is not only used for fixation, but also easy to install and disassemble.

[0047] The device used in this embodiment has a simple structure and fully protects the back of the weld during the welding process of the heat exchange tube and the tube sheet. Compared with the existing device, it is more suitable for the protection of the back of the weld during the automatic argon arc welding process of the tube sheet, thereby improving the welding quality.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A shielding gas tool for welding heat exchange tubes and tube sheets, characterized in that: include: A copper tube (2); one end of the copper tube (2) is connected to a front blocking plate (1), and the other end of the copper tube (2) is connected to a rear blocking plate (3); a protective gas pipe interface (7) is provided at the rear section of the rear blocking plate (3), and a tightening device (6) is also provided on the rear blocking plate (3); a screen (5) is wrapped around the outside of the copper tube (2) by tying with a steel wire (4); the copper tube (2) is provided with a first opening (21) and a second opening (22).

2. The shielding gas tool for welding heat exchange tubes and tube sheets according to claim 1, characterized in that: The front section of the front blocking plate (1) is provided with a first chamfer (11), and the angle of the chamfer is 45°.

3. The shielding gas tool for welding heat exchange tubes and tube sheets according to claim 1, characterized in that: A second chamfer (31) is provided at the front section of the rear blocking plate (3), and the angle of the chamfer is 45°.

4. The shielding gas tool for welding heat exchange tubes and tube sheets according to claim 1, characterized in that: The first opening (21) and the second opening (22) are tapered holes.

5. The shielding gas tool for welding heat exchange tubes and tube sheets according to claim 1, characterized in that: The front blocking plate (1) is provided with a first annular groove (12).

6. The shielding gas tool for welding heat exchange tubes and tube sheets according to claim 1, characterized in that: A second annular groove (32) is provided on the rear blocking plate (3).

7. The shielding gas tool for welding heat exchange tubes and tube sheets according to claim 1, characterized in that: The tightening device (6) comprises a right-angle copper bar (63), the bolt (61) passes through the right-angle copper bar (63), and a rubber pad (62) is fixed on the bolt (61).

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