Inner hole welding back protection device

Abstract

The utility model provides an inner hole welding back protection device which aims at solving the problem of welding seam back oxidation in the welding process of an inner hole of a heat exchanger. The device is composed of a first arc cover, a second arc cover and an air inlet pipe, a protective cavity capable of being opened and closed is formed, inert gas protection is provided, and oxidation reaction is prevented. The first arc cover and the second arc cover are connected through the arc hinge, flexible opening and closing design is achieved, and mounting and dismounting are convenient. The split type structure of the device is suitable for heat exchange tubes of different sizes and shapes, the welding quality can be effectively improved, the production efficiency is improved, the device can be repeatedly used, and the stability and durability of the device are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of protection device, concretely relates to a back face protection device for inner hole welding. BACKGROUND

[0002] In many industrial fields such as energy, chemical industry, and electric power, as a key equipment for realizing heat exchange, the performance of the heat exchanger directly affects the operation efficiency and stability of the whole system. The connection quality of the heat exchange tube and the tube plate is one of the core elements that determines the performance of the heat exchanger. Compared with the traditional fillet weld joint and the fusion head welded joint, the butt joint of the inner hole welding has better sealing, strength, and corrosion resistance. Therefore, in the industry, some important equipment or special working conditions are gradually replaced by the butt weld structure to improve the use reliability of the heat exchanger and prolong the service life.

[0003] However, during the butt welding process of the heat exchange tube and the tube plate inner hole welding, the back of the joint is easily oxidized with the surrounding air under the action of high-temperature welding heat, resulting in defects such as oxide layer, porosity, and cracks on the back of the weld. These defects not only reduce the mechanical properties of the weld, such as strength, toughness, and fatigue life, but also seriously affect the corrosion resistance of the joint, causing the heat exchanger to fail due to corrosion leakage during long-term operation, greatly shortening the service life of the equipment and increasing the equipment maintenance cost and safety risk. In addition, for materials such as stainless steel, nickel and nickel alloy, titanium and titanium alloy, their weldability is special, and inert gas protection is required on the back of the weld (outside the tube) during the inner hole welding process to effectively prevent weld oxidation and promote the formation of a good back of the weld, forming an inner hole welding butt joint that meets the quality requirements. At present, although there are some technologies and measures for welding back protection, in the specific scenario of heat exchange tube and tube plate inner hole welding butt joint, the existing protection device has the problems of complex structure, inconvenient installation, etc. In the actual operation process, the equipment needs to be frequently replaced and adjusted, and the protection device needs to be repeatedly locked or disassembled, which is not conducive to improving production efficiency. Therefore, it is of great practical significance and engineering application value to develop a back face protection device for heat exchange tube and tube plate inner hole welding butt joint with simple structure, convenient installation, and stable and reliable back face protection effect. This not only improves the manufacturing quality and performance of the heat exchanger, but also provides strong protection for the efficient and stable operation of related industrial fields. SUMMARY

[0004] This section aims to outline some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the utility model name to avoid obscuring the purpose of this section, the abstract of the specification, and the utility model name, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0005] In view of the technical problems in the prior art, the utility model provides a hole welding back surface protection device, including first arc cover, second arc cover and air inlet pipe, the first arc cover is spliced in the second arc cover forms protection cavity, the air inlet pipe is connected in the first arc cover or the second arc cover, and the air inlet pipe is communicated in the protection cavity.

[0006] As a kind of hole welding back surface protection device preferred technical scheme, the first arc cover includes first arc cover body, first arc cover front baffle and first arc cover rear baffle, the first arc cover front baffle and the first arc cover rear baffle are fixedly arranged at the both ends of the first arc cover body correspondingly.

[0007] As a kind of hole welding back surface protection device preferred technical scheme, the second arc cover includes second arc cover body, second arc cover front baffle and second arc cover rear baffle, the second arc cover front baffle and the second arc cover rear baffle are fixedly arranged at the both ends of the second arc cover body correspondingly.

[0008] As a kind of hole welding back surface protection device preferred technical scheme, the first arc cover is connected to the second arc cover by arc hinge.

[0009] As a kind of hole welding back surface protection device preferred technical scheme, the material of the first arc cover and the second arc cover is purple copper or stainless steel.

[0010] As a kind of hole welding back surface protection device preferred technical scheme, the diameter of the circular clamping groove formed by splicing the first arc cover front baffle and the second arc cover front baffle matches the outer diameter of the boss of hole welding pipe plate.

[0011] The utility model has the advantages that the weld back surface (the outside of pipe) of heat exchange pipe and pipe plate hole welding butt joint welding process does not have oxidation problem, the hole welding weld back surface is excellent, the appearance inspection requirement and weld internal quality requirement of hole welding butt joint, and use, disassembly are very convenient. DRAWINGS

[0012] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will briefly introduce the drawing needed to be used in embodiment description, obviously, the drawing in the following description is only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without paying the creativity labor intensity.Therein:

[0013] Fig. 1 It is the whole structure schematic diagram of the utility model;

[0014] Fig. 2 It is the side view structure schematic diagram of the utility model;

[0015] Fig. 3 is a structural schematic diagram of the first arc cover;

[0016] Fig. 4 is a structural schematic diagram of the second arc cover;

[0017] Fig. 5 is a schematic diagram of the installation of the protection device;

[0018] Reference signs: 10, first arc cover; 101, first arc cover body; 102, first arc cover front baffle; 103, first arc cover rear baffle; 11, second arc cover; 111, second arc cover body; 112, second arc cover front baffle; 113, second arc cover rear baffle; 12, air inlet pipe; 13, arc-shaped hinge; 14, heat exchange pipe; 15, inner hole welded pipe plate; 16, inner hole welded butt weld; 17, inner hole welding gun; DETAILED DESCRIPTION

[0019] In order to make the above-mentioned purpose, features and advantages of the present application more apparent and understandable, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0020] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can be practiced in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the spirit of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0021] Secondly, the "one embodiment" or "embodiment" referred to herein can include specific features, structures or characteristics in at least one implementation of the present application. In this specification, "in one embodiment" does not mean the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments.

[0022] Thirdly, the present application is described in detail in conjunction with the schematic diagram, and in the detailed description of the embodiments of the present application, the cross-sectional view of the device structure will be partially enlarged without general proportion for convenience of description, and the schematic diagram is only an example, which should not limit the scope of protection of the present application. In addition, three-dimensional spatial dimensions including length, width and depth should be included in actual manufacture.

[0023] Please refer to Figs. 1 to 5The utility model provides a kind of inner hole welding back face protection device, including first arc cover 10, second arc cover 11 and air inlet pipe 12.The first arc cover 10 and second arc cover 11 are formed by welding splice one closed protection cavity, air inlet pipe 12 is connected to first arc cover 10 or second arc cover 11, and air inlet pipe 12 is communicated with protection cavity.When welding, inert gas flows into protection cavity from air inlet pipe 12, forms a local gas cavity, and then provides effective gas protection for the inner hole welding area of heat exchange tube 14 and tube plate, to prevent the occurrence of oxidation reaction in the welding process.This protection device not only can effectively improve the welding quality, but also makes the welding process more simple, adapts to different sizes and shapes of heat exchange tube 14, and can be reused, improves production efficiency and product quality.

[0024] The first arc cover 10 includes a first arc cover body 101, a first arc cover front baffle 102, and a first arc cover rear baffle 103. The first arc cover front baffle 102 and the first arc cover rear baffle 103 are respectively fixed vertically on the axial ends of the first arc cover body 101 by welding, forming a semi-enclosed structure. The inner diameter of the first arc cover front baffle 102 is precisely matched with the outer diameter of the boss of the inner hole welding tube plate 15, and the inner diameter of the first arc cover rear baffle 103 is matched with the outer diameter of the heat exchange tube 14. The semi-circular arc cover formed by the front and rear baffles and the first arc cover body 101 is hinged to the second arc cover 11 by an arc-shaped hinge 13, forming an openable and closable protection cavity.

[0025] The second arc cover 11 includes a second arc cover body 111, a second arc cover front baffle 112, and a second arc cover rear baffle 113. The second arc cover front baffle 112 and the second arc cover rear baffle 113 are respectively fixed vertically on the axial ends of the second arc cover body 111 by welding, forming a symmetrical semi-enclosed structure with the first arc cover 10. The inner diameter of the second arc cover front baffle 112 is matched with the outer diameter of the boss of the inner hole welding tube plate 15 together with the first arc cover front baffle 102, forming an axial sealing surface. The inner diameter of the second arc cover rear baffle 113 is matched with the outer diameter of the heat exchange tube 14 together with the first arc cover rear baffle 103, forming an annular gas passage. After the upper and lower arc covers are hinged by the arc-shaped hinge 13, they can completely cover the outer wall of the heat exchange tube 14 in the closed state. The semi-circular arc body is matched with the gap between the outer circle of the heat exchange tube 14, forming a local sealed gas cavity during welding, and maintaining a dynamic micro-positive pressure with inert gas input by the air inlet pipe 12, realizing oxygen-free protection of the weld back. The split structure design enables the second arc cover 11 to be flexibly opened and closed by flipping through the arc-shaped hinge 13 in the environment of densely arranged heat exchange tubes 14, avoiding the installation restriction of the traditional whole device which needs to be sleeved from the tube end for a long distance, significantly improving the construction efficiency.

[0026] The upper and lower two pieces of the arc-shaped hinge 13 are respectively welded and fixed to the outer arc edge of the first arc cover body 101 and the second arc cover body 111, the curvature radius of the hinge axis is consistent with the circular arc curvature of the arc cover body, the concentric alignment of the upper and lower arc covers in the opening and closing process is ensured, the arc-shaped hinge 13 is made of the same red copper or stainless steel material as the arc cover body, meanwhile, the arc-shaped hinge 13 allows the device to be flexibly turned over at an opening and closing angle of more than 180°, and it is convenient to quickly install the device in the gap between the densely arranged heat exchange pipe 14 bundles, when operating, only the upper half arc cover needs to be rotated and closed after passing through the gap between the adjacent heat exchange pipes 14, so that the device can wrap around the outer wall of the heat exchange pipe 14 to be welded to form a local inert gas protection cavity, the hinge structure not only ensures the assembly freedom of the protection device, but also makes the closed arc cover naturally adhere to the pipe wall through the action of gravity, and cooperates with the continuous injection of the micro-positive pressure gas to effectively isolate the air from invading the back surface area of the weld.

[0027] The working principle of the utility model:

[0028] The device adopts a split type opening and closing structure design, the lower arc cover and the upper arc cover made of red copper or stainless steel material are hinged through the arc-shaped hinge 13 to form an opening and closing type protection cavity which can surround the outer diameter of the heat exchange pipe 14. When installing, the operator expands the device along the axis of the arc-shaped hinge 13, passes the upper arc cover through the gap between the adjacent heat exchange pipes 14, and then closes the device to make the front end upper and lower baffles tightly adhere to the outer diameter of the pipe plate boss, and the rear end upper and lower baffles form a seal with the outer wall of the heat exchange pipe 14. During the welding process, the inert gas is continuously injected into the gas cavity surrounded by the protection device and the outer wall of the heat exchange pipe 14 through the gas inlet pipe 12 to establish a micro-positive pressure protection environment. The size matching of the front end of the gas cavity and the pipe plate boss through the baffle realizes axial sealing, and the rear end forms radial sealing by means of the adhesion of the baffle and the pipe wall, the excess gas is orderly discharged from the gap between the devices, and the air is effectively isolated. When the welding arc acts on the inner hole welding butt weld 16, the protection system can maintain the back surface of the weld in the inert gas atmosphere throughout the process, avoid high temperature oxidation reaction, ensure that the weld back surface of titanium alloy, stainless steel and other materials is formed dense and smooth, and the split type structure realizes quick assembly and disassembly through the arc-shaped hinge 13, solves the construction difficulty that the traditional integral device needs to be sleeved from the pipe end, and significantly improves the operation efficiency and quality stability of the heat exchange pipe 14 and the pipe plate inner hole welding.

[0029] The embodiments are only used to illustrate the technical scheme of the utility model and not limit it, although the utility model has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical scheme of the utility model can be modified or replaced equivalently without departing from the spirit and scope of the technical scheme of the utility model, which should be covered in the scope of the claims of the utility model.

Claims

1. An inside hole back face welding protection device, characterized by, The first arc cover (10) is connected to the second arc cover (11) through an arc-shaped hinge (13).

2. The bore backface protection device of claim 1, wherein, The first arc cover (10) and the second arc cover (11) are made of red copper or stainless steel.

3. The bore backface protection device of claim 1, wherein, The diameter of the circular clamping groove formed by the joint of the first arc cover front baffle (102) and the second arc cover front baffle (112) matches the outer diameter of the boss of the inner hole welded pipe plate (15).

4. The bore backface protection device of claim 1, wherein, ​ 5. The bore backface protection device of claim 1, wherein, ​ 6. The bore welding back face protection device of claim 1, wherein, ​

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