Back gas protection device for terminating girth welding of pressure vessel

Abstract

The utility model belongs to the technical field of welding auxiliary devices, and particularly relates to a back gas protection device for stopping girth welding of a pressure container. The back gas protection device comprises a framework, fireproof cloth and an expansion tool, the framework and the fireproof cloth can form a tunnel-shaped structure, the framework is a supporting structure of the tunnel-shaped structure, pressure far away from the axis of the barrel is given to the framework through the expansion tool, and the barrel can give supporting force close to the axis of the barrel to the framework; by arranging the fireproof cloth on the cylinder body, a relatively closed and stable sealing cavity is formed between the fireproof cloth and the cylinder body on the two sides of the terminating circular seam, inert gas such as argon can be introduced into the sealing cavity, and therefore air replacement in the sealing cavity is achieved, and back gas protection of terminating circular seam welding is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of welding auxiliary devices, and particularly relates to a back gas protection device for welding a terminal ring seam of a pressure container. BACKGROUND

[0002] In the pressure container manufacturing industry, especially in the heat exchanger manufacturing, the terminal ring seam refers to a ring seam reserved on a cylinder due to manufacturing sequence or structural design requirements, which is to be welded after the internal structure of the container is installed, and is usually located at the connection between the cylinder and the tube plate or other components. Due to space limitations or safety considerations, personnel cannot enter the cylinder interior to perform welding, and therefore the welding process needs to strictly control the welding quality and deformation, select appropriate welding methods such as manual arc welding and submerged arc automatic welding, and perform preheating, cleaning and positioning before welding, and strict inspection and flaw detection after welding to ensure the overall performance and safety of the container.

[0003] When manufacturing containers and heat exchangers made of materials such as stainless steel, nickel-based alloy and titanium alloy, manual back gas protection cannot be performed due to the special position of the terminal ring seam, and therefore the container interior air is usually replaced with inert gas (such as argon) to prevent root weld oxidation, but as the cylinder volume increases, the replacement time and gas cost increase sharply, and due to internal air turbulence, the oxygen content at the top of the container is still likely to exceed the standard after long-time replacement, resulting in welding failure.

[0004] Therefore, there is an urgent need for a back gas protection device for welding a terminal ring seam of a pressure container, which can create a relatively closed space in the welding area. CONTENT OF THE INVENTION

[0005] The application aims to provide a back gas protection device for welding a terminal ring seam of a pressure container, which can create a relatively closed space in the welding area.

[0006] The embodiments of the application can be implemented by the following technical solutions:

[0007] A back gas protection device for welding a terminal ring seam of a pressure container, comprising a framework, fireproof cloth and expansion tooling;

[0008] A plurality of frameworks are connected side by side on the fireproof cloth, the framework comprises a plurality of framework main bodies connected side by side, the framework main body is in a U-shaped structure, the framework main body comprises a crossbeam and support arms connected to both ends of the crossbeam, the crossbeam and the support arms are arranged in a non-coplanar manner, the support arms of the framework main bodies on both sides of the framework extend towards the outside, and the adjacent framework main bodies of each framework are connected through the crossbeam;

[0009] The first expansion tool placing slot is formed between the cross beams, the fireproof cloth is connected to the outside of the framework, and a second expansion tool placing slot corresponding to the expansion tool is formed on the outside of the cross beam at a position corresponding to the expansion tool. The expansion tool is simultaneously accommodated in the first expansion tool placing slot and the second expansion tool placing slot and is clamped in the first expansion tool placing slot.

[0010] Further, the distance between the support arms of the framework body on the two side edges of the framework is greater than the gap of the termination ring seam.

[0011] Preferably, the framework body is made of a high-elastic thin metal sheet punched and added.

[0012] Preferably, the framework includes two framework bodies, and the framework has a saddle-shaped structure in a free state.

[0013] Further, the framework further includes a fireproof cloth connecting portion located at the bottom of the support arm of the framework body on the two side edges of the framework.

[0014] Preferably, the fireproof cloth has a closed ring structure.

[0015] Preferably, a temporary fixing tool is further included, one end of the temporary fixing tool is inserted into the cylinder from the termination ring seam and is clamped with the framework, and the other end is placed on the outside of the cylinder and is in position abutment with the outer wall of the cylinder.

[0016] Further, the temporary fixing tool includes a limiting portion, an extension portion and a clamping portion connected in sequence, the limiting portion is placed on the outside of the cylinder and is in position abutment with the outer wall of the cylinder on one side facing the cylinder, the extension portion is inserted into the cylinder through the termination ring seam, and the clamping portion is clamped and connected with the cross beam.

[0017] Further, the limiting portion has an outer diameter greater than the gap width of the termination ring seam.

[0018] Further, the clamping portion is a clamping groove structure at the end of the extension portion.

[0019] The embodiment of the present application provides a back gas protection device for pressure vessel termination ring seam welding, which has at least the following beneficial effects:

[0020] The framework and fireproof cloth in the application can form a tunnel type structure, the framework is a support structure of the tunnel type structure, and the framework is given a pressure away from the axis of the cylinder by the expansion tool, the cylinder gives the framework a support force close to the axis of the cylinder, so that a relatively closed and stable sealed cavity is formed between the fireproof cloth and the cylinder on both sides of the termination ring gap, inert gas such as argon can be introduced into the sealed cavity, so that the air in the sealed cavity is replaced, so as to realize the back gas protection of the termination ring gap welding;

[0021] The crossbeam of the framework body in the application is arranged non-coplanar with the support arm, and is stamped and processed from a thin metal sheet with good elasticity, and is in a saddle-like structure in a free state, and is in a sheet structure when being pressed, so that the framework can conveniently and without obstacles enter the cylinder from the narrow termination ring gap, and the framework is also convenient and easy to take out after welding is completed;

[0022] The fireproof cloth connecting part in the application is located at the bottom wall of the support arm, so that the fireproof cloth can be close to the inner wall of the cylinder, so as to ensure the relative closed effect of the formed sealed cavity;

[0023] The expansion tool in the application can be switched between a relaxed state and an inflated state, so as to realize compression or loosening, and complete the formation and removal of the compression relationship between the back gas protection device and the cylinder;

[0024] In the application, the temporary fixing tool is used to ensure the temporary fixing of the back gas protection device and the cylinder, so as to provide hardware support and time support for the state switching of the expansion tool. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a whole structure diagram of the back gas protection device in the application;

[0026] Figure 2 It is a whole structure diagram of the framework in the application;

[0027] Figure 3 It is a top view of the framework in the application;

[0028] Figure 4 It is a side view of the framework in the application;

[0029] Figure 5 It is another angle side view of the framework in the application;

[0030] Figure 6 It is a cooperation schematic view of the temporary fixing tool and the framework at the termination ring gap position in the application;

[0031] Figure 7 It is a side view schematic view of the cooperation of the temporary fixing tool and the framework at the termination ring gap position in the application;

[0032] Figure 8A side view of the temporary fixing tool in the present application;

[0033] Figure 9 A cross-sectional structure diagram of the barrel and the framework, and the expansion tool in the present application.

[0034] Reference signs: barrel X, termination ring seam Y, sealing cavity S, framework 1, framework main body 11, support arm 111, crossbeam 112, first expansion tool placing groove 12, fireproof cloth connecting part 13, fireproof cloth 2, second expansion tool placing groove 21, expansion tool 3, temporary fixing tool 4, limiting part 41, extension part 42, clamping part 43. DETAILED DESCRIPTION

[0035] Hereinafter, the present application will be further described based on the preferred embodiments and with reference to the accompanying drawings.

[0036] The words in the present specification are used for describing the embodiments of the present application, but are not intended to limit the present application. Unless otherwise explicitly specified and limited, if the terms “provided”, “connected”, “connected” appear, they should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be directly connected, or indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be specifically understood.

[0037] In addition, in the description in the embodiments of the present application, various components on the drawing are enlarged or reduced for the convenience of understanding, but this practice is not intended to limit the protection scope of the present application.

[0038] The present application provides a back gas protection device for the termination ring seam welding of a pressure vessel, which acts on the termination ring seam Y position of the barrel X, and is used for providing a relatively closed space during the welding process. Figure 1 The overall structure diagram of the back gas protection device in the present application is shown, Figure 9 The cross-sectional schematic diagram of the back gas protection device and the barrel X is shown, such as Figure 1 and Figure 9As shown, the back gas protection device comprises a framework 1, a fireproof cloth 2 and an expansion tool 3. A plurality of frameworks 1 are arranged on the fireproof cloth 2 in parallel. The framework 1 comprises a plurality of framework bodies 11 connected in parallel. The framework body 11 has a U-shaped structure. The framework body 11 comprises a crossbeam 112 and support arms 111 connected to both ends of the crossbeam 112. The crossbeam 112 and the support arms 111 are arranged in a non-coplanar manner. The adjacent framework bodies 11 of each framework 1 are connected through the crossbeams 112. The first expansion tool placing grooves 12 are formed between the crossbeams 112. The support arms 111 of the framework bodies 11 on both sides of the framework 1 extend towards the outer side thereof. The fireproof cloth 2 is connected to the outer side of the framework 1. The second expansion tool placing grooves 21 corresponding to the expansion tool 3 are formed on the outer side of the fireproof cloth 2 corresponding to the crossbeams 112. The expansion tool 3 is accommodated in the first expansion tool placing grooves 12 and the second expansion tool placing grooves 21 and is clamped in the first expansion tool placing grooves 12. When the back gas protection device is installed at the position of the terminal ring seam Y in the cylinder X, the back gas protection device has a tunnel structure. The bottoms of the support arms 111 of the framework bodies 11 on both sides of the framework 1 abut against the inner walls of the cylinder X on both sides of the terminal ring seam Y. The expansion tool 3 is accommodated in the first expansion tool placing grooves 12 and the second expansion tool placing grooves 21 and is clamped in the first expansion tool placing grooves 12. The crossbeams 112 and the support arms 111 of the framework 1 are given a pressure away from the axis of the cylinder X. The cylinder X gives the support arms 111 a support force towards the axis of the cylinder X. The fireproof cloth 2 forms a relatively closed and stable sealed cavity S between the fireproof cloth 2 and the cylinder X on both sides of the terminal ring seam Y. Inert gas such as argon is introduced into the sealed cavity S during the welding process. After a period of replacement, welding can be performed to realize back gas protection of the terminal ring seam Y.

[0039] Further, the distance between the support arms 111 of the framework bodies 11 on both sides of the framework 1 is greater than the gap of the terminal ring seam Y to ensure that the tunnel structure formed by the fireproof cloth 2 faces the terminal ring seam Y and further ensure the formation of the sealed cavity S. Therefore, the framework 1 needs to have a certain deformation space to smoothly pass through the gap of the terminal ring seam Y.

[0040] In some specific embodiments of the present application, the terminal ring seam Y has a gap of more than 5 mm. The framework 1 needs to be placed into the cylinder X through the gap by extrusion. After the framework 1 enters the cylinder X, it returns to a free state. Then, the sealed cavity S is built by cooperating with the expansion tool 3 and the fireproof cloth 2.

[0041] In some preferred embodiments of the present application, the framework body 11 is made of a high-elasticity material.

[0042] Further, to ensure the stability and strength of the support, the framework body 11 is made of a thin metal sheet punched and processed.

[0043] In some specific embodiments of the present application, to realize the connection between the metal framework bodies 11, the connection between the framework bodies 11 can be realized by means of gluing, welding, hinging, etc. The connection between the thin metal sheets in the present application is realized by means of resistance welding.

[0044] In some specific embodiments of the present application, the high-elasticity material is stainless steel, because in actual production, the cylinder X generally needs to be made of special material for back gas protection, so that the framework body 11 cannot be made of carbon spring steel material.

[0045] In some specific embodiments of the present application, as shown in Figures 2-5 The framework 1 is in a saddle-shaped structure in a free state, and cooperates with the fireproof cloth 2 wrapped outside to maintain support and form a sealed cavity S; when the framework 1 is subjected to compression force from both sides, the framework 1 is in a sheet-shaped structure, which can conveniently and without obstacles enter the cylinder X from the narrow termination ring seam Y, and similarly, the framework 1 is also convenient and easy to take out after welding. It can be imagined that in actual production, the number of framework bodies 11 can be set based on actual needs, and of course, after the number of framework bodies 11 is changed, the framework bodies 11 can still be in a sheet-shaped structure during extrusion, and as long as the support arms 111 of the framework bodies 11 all abut against the inner wall of the cylinder X in a free state, the framework bodies 11 can still be in a sheet-shaped structure during extrusion.

[0046] Further, as shown in Figure 2 To ensure the stable connection of the framework 1 and the fireproof cloth 2, the framework 1 further comprises a fireproof cloth connecting portion 13, which is located at the bottom of the support arm 111 of the framework body 11 on the two side edges of the framework 1, so that the fireproof cloth 2 can tightly abut against the inner wall of the cylinder X to ensure the relative sealing effect of the sealed cavity S.

[0047] In some specific embodiments of the present application, as shown in Figure 9 A plurality of frameworks 1 are connected in parallel on the fireproof cloth 2. It can be imagined that a plurality of frameworks 1 can also be connected end to end on the fireproof cloth 2, and as long as the frameworks 1 can be connected in parallel in any way, the frameworks 1 can support the fireproof cloth 2 and cooperate with the fireproof cloth 2 and the cylinder X to form a sealed cavity S.

[0048] In some specific embodiments of the present application, the height of the framework 1 in a free state is at least 80 mm or more, so as to ensure that the electric arc in the welding process does not cause the back gas protection device to overheat.

[0049] In some specific embodiments of the present application, the width of the framework 1 when expanded is at least 50 mm or more, that is, the distance between the bottoms of the support arms 111 of the framework bodies 11 on the two side edges of the framework 1 in a free state is at least 50 mm or more, so as to ensure that the heat-affected zones on both sides of the termination ring seam Y are within the range of atmosphere protection.

[0050] In some preferred embodiments of the present application, the fireproof cloth 2 is in a closed ring structure to further ensure the relative sealing of the sealed cavity S.

[0051] In some specific embodiments of the present application, the expansion tool 3 is a gas expansion tool, which can change its volume and state by being inflated to achieve stable compression of the skeleton 1. It is conceivable that the expansion tool 3 can also be a liquid expansion tool, as long as it can smoothly enter the barrel X and change to the compressed ring side of the skeleton 1 and the fireproof cloth 2.

[0052] In some preferred embodiments of the present application, the gas expansion tool is further fixedly connected with the skeleton 1 by a high-elasticity silica gel ring, which has a certain elasticity so that the gas expansion tool can be clamped and bound on the skeleton 1 in both the relaxed state and the inflated state, to achieve stable connection of the expansion tool 3 and the skeleton 1.

[0053] Further, when the expansion tool 3, the skeleton 1 and the fireproof cloth 2 enter the barrel X from the narrow termination ring gap Y, the expansion tool 3 is in a relaxed state and cannot provide sufficient extrusion pressure to the skeleton 1 to be compressed at the termination ring gap Y of the barrel X, so that the skeleton 1 cannot be relatively fixed at the termination ring gap Y when it is in a free state. Therefore, to ensure temporary fixation of the back gas protection device at the position when it enters the barrel X from the termination ring gap Y, the back gas protection device in the present application further comprises a temporary fixing tool 4, which is inserted into the barrel X from the outside of the barrel X at the termination ring gap Y and is clamped and connected with the skeleton 1 to achieve temporary fixation of the back gas protection device at the position of the barrel X.

[0054] Figures 6-8 The cooperation between the temporary fixing tool 4 and the skeleton 1 at the termination ring gap Y and the side view of the temporary fixing tool 4 are shown in FIGS. 4 and 5, respectively. Figures 6-8 As shown in FIG. 4, one end of the temporary fixing tool 4 is clamped and connected with the skeleton 1 from the termination ring gap Y into the barrel X, and the other end is placed outside the barrel X and abuts against the outer wall of the barrel X.

[0055] Specifically, the temporary fixing tool 4 comprises a limiting portion 41, an extending portion 42 and a clamping portion 43 connected in sequence, the limiting portion 41 is placed outside the barrel X and abuts against the outer wall of the barrel X, the extending portion 42 extends into the barrel X through the termination ring gap Y, and the clamping portion 43 is clamped and connected with the cross beam 112 of the skeleton main body 11.

[0056] Further, the outer diameter of the limiting portion 41 is greater than the gap width of the termination ring gap Y, so as to abut against the outer wall of the barrel X.

[0057] In some specific embodiments of the present application, as shown in Figure 8 The clamping portion 43 is a clamping groove structure at the end of the extension portion 42, which can be clamped on the outer side of the cross beam 112 to achieve clamping connection with the cross beam 112. It can be imagined that the clamping portion 43 can also be provided in other structures, which will not be described further here.

[0058] In some specific embodiments of the present application, as shown in Figure 8 The limiting portion 41 is a one-letter structure, so that the temporary fixing tool 4 as a whole is in a T-shaped structure. It can be imagined that the limiting portion 41 can also be provided in an X-shaped structure, a Y-shaped structure, and other regular or irregular structures. No matter what structure the limiting portion 41 is provided in, as long as it can achieve limiting abutment with the outer wall of the cylinder X at the joint Y of the termination ring, it is acceptable.

[0059] In some specific embodiments of the present application, the number of temporary fixing tools 4 corresponds to the number of skeletons 1, that is, each skeleton 1 has a corresponding temporary fixing tool 4 connected thereto, to ensure the stability of the back gas protection device and the temporary fixing of the cylinder X. It can be imagined that multiple temporary fixing tools 4 can be connected to each skeleton 1, or some skeletons 1 can be connected to temporary fixing tools 4. In actual production process, the number of temporary fixing tools 4 can be set based on actual needs. No matter how the temporary fixing tool 4 corresponds to the skeleton 1, as long as it can fix the relative position of the skeleton 1 and the cylinder X.

[0060] In summary, the use process of the back gas protection device in the present application is as follows: the skeleton 1 is flattened and put into the cylinder X through the joint Y of the termination ring synchronously with the fireproof cloth 2 and the expansion tool 3. After the skeleton 1 is inserted into the cylinder X, it will rebound to the free state, thereby driving the fireproof cloth 2 to stretch and form a tunnel-shaped shape. Then the skeleton 1 is temporarily fixed at the joint Y of the termination ring by the temporary fixing tool 4. Then the expansion tool 3 is inflated to press the fireproof cloth 2 and the skeleton 1 tightly. At this time, the sealed cavity S for back gas protection is completed. Then the temporary fixing tool 4 is removed, and then the inert gas such as argon is introduced into the sealed cavity S. After a period of replacement, welding can be carried out. After the welding is completed, the expansion tool 3 is loosened by deflation, and the pressing relationship between the back gas protection device and the cylinder X is released. The back gas protection device can be separated from the termination joint Y, and then the back gas protection device can be pulled out through other pipe holes by using a hook.

[0061] The specific embodiments of the present application are described in detail above. For those skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also belong to the protection scope of the claims of the present application.

Claims

1. A back gas protection device for pressure vessel termination ring seam welding, characterized in that: it comprises a framework (1), a fireproof cloth (2) and an expansion tool (3); a plurality of said frameworks (1) are connected side by side on said fireproof cloth (2), said framework (1) comprises a plurality of framework bodies (11) connected side by side, said framework body (11) is in U-shaped structure, said framework body (11) comprises a crossbeam (112) and support arms (111) connected to both ends of said crossbeam (112), said crossbeam (112) and said support arms (111) are arranged non-coplanarly, said support arms (111) of said framework bodies (11) on both side edges of said framework (1) extend towards the outside, said crossbeams (112) are connected between adjacent said framework bodies (11) of each said framework (1); first expansion tool placing grooves (12) are formed between said crossbeams (112), said fireproof cloth (2) is connected to the outside of said framework (1), second expansion tool placing grooves (21) corresponding to said expansion tool (3) are formed on the outside of said crossbeams (112) in corresponding positions, said expansion tool (3) is simultaneously accommodated in said first expansion tool placing grooves (12) and said second expansion tool placing grooves (21) and clamped in said first expansion tool placing grooves (12).

2. The back gas protection device for pressure vessel termination ring seam welding according to claim 1, characterized in that: the distance between said support arms (111) of said framework bodies (11) on both side edges of said framework (1) is greater than the gap of the termination ring seam (Y).

3. The back gas protection device for pressure vessel termination ring seam welding according to claim 2, characterized in that: said framework bodies (11) are made by stamping addition of high-elastic thin metal sheets.

4. The back gas protection device for pressure vessel termination ring seam welding according to claim 3, characterized in that: said framework (1) comprises two said framework bodies (11), said framework (1) is in saddle-shaped structure in free state.

5. The back gas protection device for pressure vessel termination ring seam welding according to claim 1, characterized in that: said framework (1) further comprises a fireproof cloth connecting part (13), said fireproof cloth connecting part (13) is located at the bottom of said support arms (111) of said framework bodies (11) on both side edges of said framework (1).

6. The back gas protection device for pressure vessel termination ring seam welding according to claim 1, characterized in that: said fireproof cloth (2) is in closed ring-shaped structure.

7. The back gas protection device for pressure vessel termination ring seam welding according to claim 1, characterized in that: it further comprises a temporary fixing tool (4), one end of said temporary fixing tool (4) is inserted into the cylinder (X) from the termination ring seam (Y) and clamped with said framework (1), the other end is placed on the outside of said cylinder (X) and abuts against the outer wall of said cylinder (X). ​ ​ ​ ​ ​ ​ ​ ​ ​ 8. The back gas protection device for pressure vessel termination ring seam welding according to claim 7, characterized in that: The temporary fixing tool (4) comprises a limiting portion (41), an extending portion (42) and a clamping portion (43) connected in sequence, the limiting portion (41) is placed on the outer side of the cylinder (X) and abuts against the outer wall of the cylinder (X) on the side facing the cylinder (X), the extending portion (42) extends into the cylinder (X) through the termination ring seam (Y), and the clamping portion (43) is clamped and connected with the cross beam (112).

9. The back gas protection device for pressure vessel termination ring seam welding according to claim 8, characterized in that: The outer diameter of the limiting portion (41) is greater than the gap width of the termination ring seam (Y).

10. The back gas protection device for pressure vessel termination ring seam welding according to claim 8, characterized in that: The clamping portion (43) is a clamping groove structure at the end of the extending portion (42).

Images