A narrow-band electroslag welding auxiliary device for large connecting pipes of petrochemical heat exchanger tube box

Abstract

An auxiliary device for narrow-strip electroslag welding of large-diameter tube fittings in petrochemical heat exchanger tube boxes is disclosed. This invention relates to the field of petrochemical heat exchanger tube boxes. Existing argon arc welding methods suffer from low deposition efficiency and require meticulous point-by-point, layer-by-layer operations, resulting in long welding times for individual tube fittings. This invention comprises an auxiliary roller, a tube box fitting, a transition connector, and a rotating roller frame. The auxiliary roller is mounted on the roller of the rotating roller frame, which drives the auxiliary roller to rotate. The tube box fitting is installed inside the auxiliary roller, and the transition connector is installed on the inner wall of the auxiliary roller, with its tail fixedly connected to the inner wall of the auxiliary roller and its head connected to the tube box fitting. By rotating the tube box fitting driven by the auxiliary roller and transition connector, narrow-strip electroslag welding of large-diameter tube box fittings or small-diameter cylinders is achieved, improving welding efficiency. This invention is applied in the field of petrochemical heat exchanger tube box welding.

Description

Technical Field

[0001] This utility model relates to the field of petrochemical heat exchanger tube boxes, specifically to an auxiliary device for narrow-band electroslag welding of large connecting pipes in petrochemical heat exchanger tube boxes. Background Technology

[0002] In the manufacturing of containers and heat exchangers, there is a common practice of strip welding on the surface of tube sheets and strip submerged arc welding on the inner wall of large-diameter cylinders. Since the strip welding head and the matching welding strip and flux delivery device are relatively large in size, they are more suitable for large-diameter cylinders or tube boxes. For small-diameter cylinders and connecting pipes, carbon dioxide gas shielded welding or argon arc welding is used.

[0003] Taking a waste heat boiler and steam superheater as an example, this equipment, originally reliant on imports, faces numerous technical challenges in its localization process. Among these challenges, the welding process for the large-diameter inlet and outlet pipes in the equipment's pipe box is particularly problematic. The inner diameters of these pipes are mostly in the range of φ500-φ800 mm. From a dimensional perspective, compared to large-diameter components suitable for submerged arc welding, their internal space is relatively narrow, making it difficult to adapt to the operational requirements of submerged arc welding equipment. Even more problematic is the use of nickel-based alloys as the welding material for these pipes. While nickel-based alloys possess excellent high-temperature and corrosion resistance, they also present significant welding challenges. Based on these factors, the original welding process opted for argon arc welding. Although argon arc welding can effectively guarantee the quality of nickel-based welds, its low deposition efficiency and the need for meticulous point-by-point, layer-by-layer operations result in a welding time of nearly a month for a single pipe, severely restricting the equipment's production cycle, significantly increasing manufacturing costs, and leading to low efficiency. Utility Model Content

[0004] In order to solve the shortcomings of the existing argon arc welding method, which has low deposition efficiency and requires precise point-by-point and layer-by-layer operation, resulting in a long welding time for a single pipe, this utility model provides an auxiliary device for narrow-band electroslag welding of large pipes in petrochemical heat exchanger tube boxes.

[0005] The technical solution of this utility model is:

[0006] An auxiliary device for narrow-band electroslag welding of large connecting pipes in petrochemical heat exchanger tube boxes is provided, comprising an auxiliary roller, a tube box connecting pipe, a transition connector, and a rotating roller frame.

[0007] The auxiliary roller is mounted on the roller of the rotating roller frame, which drives the auxiliary roller to rotate. The pipe box connector is installed inside the auxiliary roller. The transition connector is installed on the inner wall of the auxiliary roller, and the tail of the transition connector is fixedly connected to the inner wall of the auxiliary roller. The head of the transition connector is connected to the pipe box connector.

[0008] Furthermore, the transition connector has a two-layer structure inside the auxiliary roller, and each layer of the transition connector consists of four transition connectors.

[0009] Furthermore, the transition connectors are arranged circumferentially inside the auxiliary roller, and the distance between the upper and lower transition connectors and the end of the pipe box connector is 45-55mm.

[0010] Furthermore, the transition connector adopts a rectangular steel plate structure.

[0011] Furthermore, the feature is that two adjacent transition connectors in each layer are arranged at a 90-degree angle on the inner wall of the auxiliary roller.

[0012] Furthermore, the outer diameter of the pipe box connecting pipe is the same, and the dimensions of the transition connectors of the upper and lower layers are the same;

[0013] The outer diameter of the pipe box connector is different, and the size of the transition connector is adjusted according to the outer diameter of the pipe box connector.

[0014] Furthermore, the auxiliary roller rotates on the rotating roller frame, driving the pipe box connector inside the auxiliary roller to rotate, thereby achieving circumferential welding.

[0015] Furthermore, after the pipe box connector is connected to the transition connector, the pipe box connector and the auxiliary roller are arranged concentrically.

[0016] Furthermore, the side of the pipe box connector is provided with a strip welding system, which includes a welding head, a power supply and connecting pipes, and performs circumferential welding on the pipe box connector.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] This invention clearly defines the boundary between strip electrode welding and wire electrode welding, enabling narrow strip electrode welding of large-diameter pipe box connectors or small-diameter cylinders, improving welding efficiency, ensuring welding quality, shortening product manufacturing cycle, and reducing costs.

[0019] This utility model utilizes existing equipment with simplified auxiliary devices and optimized original equipment parameters to achieve the goal of narrow-band electroslag welding of large-diameter pipes and similar-sized cylinders, ensuring stable welding quality, increasing efficiency by 10 times, and achieving the goal of improving quality, efficiency and reducing costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 yes Figure 1 A schematic diagram of the structure when the pipe box is installed into the auxiliary roller;

[0022] Figure 3 yes Figure 1 AA section view in the middle;

[0023] Figure 4 This is a structural diagram of the pipe box connection welding process;

[0024] In the diagram: 1. Auxiliary roller, 2. Pipe box connector, 3. Transition connector, 4. Rotating roller frame, 5. Welding and desoldering zone, 6. Strip electrode welding system. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0026] Specific implementation method one: Combining Figure 1 and Figure 2 This embodiment describes an auxiliary device for narrow-band electroslag welding of a large connecting pipe in a petrochemical heat exchanger tube box. The auxiliary device includes an auxiliary roller 1, a tube box connecting pipe 2, a transition connector 3, and a rotating roller frame 4.

[0027] The auxiliary roller 1 is mounted on the roller of the rotating roller frame 4. The rotating roller frame 4 drives the auxiliary roller 1 to rotate. The pipe box connector 2 is installed inside the auxiliary roller 1. The transition connector 3 is installed on the inner wall of the auxiliary roller 1, and the tail of the transition connector 3 is fixedly connected to the inner wall of the auxiliary roller 1. The head of the transition connector 3 is connected to the pipe box connector 2.

[0028] The pipe box connector 2 and the auxiliary roller 1 are connected by multiple sets of transition connectors 3 arranged at equal intervals, and multiple transition connectors 3 in each set of transition connectors 3 are installed in a circumferential array between the pipe box connector 2 and the auxiliary roller 1.

[0029] An auxiliary roller 1 is added, and the pipe box connector is placed in the middle of the auxiliary roller 1 and connected by a transition connector 3. The auxiliary roller 1 rotates on the rotating roller frame 4, driving the internal pipe box connector 2 to rotate, realizing circumferential welding and expanding the function of small-diameter pipe box connector 2. That is, four modes of welding are available: 60mm strip welding, 30mm strip welding, carbon dioxide gas shielded welding, and argon arc welding.

[0030] Specific Implementation Method Two: Combining Figure 1 and Figure 2 This embodiment describes an auxiliary device for narrow-band electroslag welding of a large connecting pipe in a petrochemical heat exchanger tube box. The transition connector 3 has an upper and lower two-layer structure inside the auxiliary roller 1, and the number of multiple transition connectors 3 in each group is four, six, or eight.

[0031] The pipe box connector 2 is connected by a transition connector 3. When the auxiliary roller 1 rotates, the pipe box connector 2 is driven to rotate through the transition connector 3.

[0032] Specific implementation method three: Combining Figure 1 and Figure 2 This embodiment describes an auxiliary device for narrow-band electroslag welding of a large connecting pipe in a petrochemical heat exchanger tube box. The transition connector 3 is arranged circumferentially inside the auxiliary roller 1. The distance between a set of transition connectors 3 at the rear end of the auxiliary roller 1 and the end of the tube box connecting pipe 2 is L, where L is 45-55mm.

[0033] The upper transition connector 3 and the lower transition connector 3 are fixed to the inner wall of the auxiliary roller 1 by welding, and the corresponding transition connectors of the upper transition connector 3 and the lower transition connector 3 are on the same plane.

[0034] Specific implementation method four: Combination Figure 1 and Figure 2 This embodiment describes a narrow-band electroslag welding auxiliary device for the large connecting pipe of a petrochemical heat exchanger tube box, wherein the transition connector 3 adopts a rectangular steel plate structure.

[0035] The tail end of the transition connector 3 is welded to the inner wall of the auxiliary roller 1. When the pipe box connector 2 is hoisted into the auxiliary roller 1, the head end of the transition connector 3 is welded to the outer circumferential pipe wall of the pipe box connector 2 so that the pipe box connector 2 can rotate synchronously with the auxiliary roller 1. After the pipe box connector 2 completes the electroslag welding, the welded joint of the pipe box connector 2 is dewelded to the transition connector 3, and the pipe box connector 2 is hoisted out of the auxiliary roller 1.

[0036] Specific Implementation Method Five: Combining Figure 1 and Figure 2This embodiment describes an auxiliary device for narrow-band electroslag welding of a large connecting pipe in a petrochemical heat exchanger tube box. In this embodiment, two adjacent transition connectors 3 are arranged at 90 degrees on the inner wall of the auxiliary roller 1.

[0037] The transition connector 3 can support and fix the pipe box and pipe 2 inside the auxiliary roller 1. Each layer of transition connector 3 is arranged circumferentially, and the two adjacent transition connectors 3 in each layer are 90 degrees apart, which ensures that the pipe box and pipe 2 can be better supported and fixed when entering the auxiliary roller 1.

[0038] Specific Implementation Method Six: Combination Figure 1 and Figure 2 This embodiment describes an auxiliary device for electroslag overlay welding of a narrow strip electrode in a petrochemical heat exchanger tube box. The outer diameter of the tube box tube 2 is the same, and the dimensions of the transition connectors 3 of the upper and lower layers are the same.

[0039] When the pipe box connector 2 is a variable diameter pipe, the size of the transition connector 3 is adapted to the distance between the pipe box connector 2 and the auxiliary roller 1.

[0040] Specific implementation method seven: Combination Figure 1 and Figure 2 This embodiment describes an auxiliary device for narrow-band electroslag welding of a large connecting pipe in a petrochemical heat exchanger tube box. The rotating roller frame 4 has n rollers, where n is an even number ≥ 4. The n rollers rotate in the same direction, and the n rollers drive the auxiliary roller 1 and the connecting pipe 2 in the tube box to rotate.

[0041] The auxiliary roller 1 rotates on the rotating roller frame 4, which drives the pipe box and connecting pipe 2 inside the auxiliary roller 1 to rotate, thereby achieving circumferential welding.

[0042] Specific implementation method eight: Combination Figure 1 and Figure 2 This embodiment describes an auxiliary device for electroslag overlay welding of a narrow strip electrode in a petrochemical heat exchanger tube box. After the tube box tube 2 is connected to the transition connector 3, the tube box tube 2 and the auxiliary roller 1 are arranged concentrically.

[0043] Specific Implementation Method Nine: Combining Figure 1 and Figure 2 This embodiment describes an auxiliary device for narrow-strip electroslag welding of a large connecting pipe in a petrochemical heat exchanger tube box. The side of the connecting pipe 2 is provided with a strip welding system, which includes a welding head, a power supply, and connecting pipes. The strip welding system performs circumferential welding on the connecting pipe 2.

[0044] Welding process:

[0045] Step 1: An improved 2×2 welding machine is adopted, controlled by two separate traveling mechanisms. This allows for simultaneous welding of two different parts, or during the welding process, certain parameters of the welding machine, such as current and voltage, can be switched in two stages or modes according to two different sets of settings to adapt to different welding needs. For example, different parameters can be used during arc initiation and welding. An electrode cladding system is added on the reverse side, including the welding head, power supply, and connecting pipelines, utilizing the 2×2 traveling mechanism.

[0046] Step 2: Adopt the smallest possible size structure, including transition connection structure, welding strip feeding and straightening mechanism, flux cylinder and delivery hose, auxiliary insulation device, and control section layout, etc.

[0047] Step 3: For the pipe box connector 2 that needs to be welded, a transition connection is made through the transition connector 3 to enable the pipe box connector 2 to rotate. An auxiliary roller 1 is installed, and the pipe box connector 2 is placed in the middle of the auxiliary roller 1 and connected through the transition connector 3. The auxiliary roller 1 rotates on the rotating roller frame 4, which drives the internal pipe box connector 2 to rotate, and performs circumferential welding on the pipe box connector 2 to realize the functional expansion for small diameter connectors.

[0048] Step 4: Preheating is achieved using an external preheating fixture, which is fixed on the outside and the preheating head is inserted into the auxiliary roller 1 to achieve the purpose of fixing the pipe box and connecting pipe 2 and rotating the pipe box and connecting pipe 2 for preheating.

[0049] Step 5: Based on the experiment, the head structure was optimized, reducing the width from 60mm to 30mm, thus ensuring stable welding quality.

[0050] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model's technical solution. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present utility model's technical solution, based on the technical essence of the present utility model and within the spirit and principles of the present utility model, shall still fall within the protection scope of the present utility model's technical solution.

Claims

1. A narrow strip electrode electroslag surfacing auxiliary device for a large connecting pipe of a petrochemical heat exchanger tube box, characterized in that, The auxiliary device for narrow-band electroslag welding of the large pipe of the petrochemical heat exchanger tube box includes an auxiliary roller (1), a tube box pipe (2), a transition connector (3), and a rotating roller frame (4). The auxiliary roller (1) is installed on the roller of the rotating roller frame (4). The rotating roller frame (4) drives the auxiliary roller (1) to rotate. The pipe box connector (2) is coaxially installed inside the auxiliary roller (1). The pipe box connector (2) and the auxiliary roller (1) are connected by multiple sets of transition connectors (3) arranged at equal intervals. The multiple transition connectors (3) in each set of transition connectors (3) are installed in a circumferential array between the pipe box connector (2) and the auxiliary roller (1).

2. The narrow strip electrode electroslag cladding auxiliary device for petrochemical heat exchanger tube box large connector according to claim 1, characterized in that, The number of transition connectors (3) in each group of transition connectors (3) is four, six, or eight.

3. The narrow strip electrode electroslag cladding auxiliary device for petrochemical heat exchanger tube box large connector according to claim 2, characterized in that, The distance between a set of transition connectors (3) located at the rear end of the auxiliary roller (1) and the end of the pipe box connector (2) is L, where L is 45-55mm.

4. The narrow strip electrode electroslag cladding auxiliary device for petrochemical heat exchanger tube box large connector according to claim 2 or 3, characterized in that, The transition connector (3) adopts a rectangular steel plate structure.

5. The auxiliary device for narrow strip electroslag welding of large pipe in petrochemical heat exchanger tube box according to claim 2 or 3, characterized in that the transition connector (3) is fixedly installed on the inner wall of the auxiliary roller (1) by welding.

6. The narrow strip electrode electroslag cladding auxiliary device for petrochemical heat exchanger tube box large connector according to claim 1, characterized in that, When the pipe box connector (2) is a variable diameter pipe, the size of the transition connector (3) is adapted to the distance between the pipe box connector (2) and the auxiliary roller (1).

7. The narrow strip electrode electroslag cladding auxiliary device for petrochemical heat exchanger tube box large connector according to claim 1, characterized in that, The rotating roller frame (4) has n rollers, n being an even number ≥ 4. The n rollers rotate in the same direction, and the n rollers drive the auxiliary roller (1) and the pipe box connector (2) to rotate.

8. The narrow strip electrode electroslag cladding auxiliary device for petrochemical heat exchanger tube box large connector according to claim 6, characterized in that, The distance between two adjacent sets of transition connectors (3) is 100-300cm.

9. The narrow strip electrode electroslag cladding auxiliary device for petrochemical heat exchanger tube box large connector according to claim 3, characterized in that, L is 50mm.

10. The petrochemical heat exchanger channel header large nozzle narrow strip electrode electro slag cladding auxiliary device according to claim 6, characterized in that, The length of the pipe box connector (2) is less than the length of the auxiliary roller (1).

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