Welding preheating device suitable for spherical shell plate

Abstract

A preheating device suitable for spherical shell plate welding comprises a distribution pipe which is of an arc-shaped structure and matched with the outer contour of a spherical shell. A plurality of air outlet holes are symmetrically and uniformly distributed in the inner side of the distribution pipe and are communicated and hermetically connected with the air outlet pipe, a ball valve is mounted at the other end of the air outlet pipe, and a nozzle is mounted at the front end of the ball valve; the gas inlet pipes II are respectively arranged at the upper section and the lower section of the outer side of the distribution pipe and are in through sealing connection with the distribution pipe, the gas inlet pipes II are in through sealing connection with the gas inlet pipe I, the gas inlet pipe I is in through sealing connection with the main gas inlet pipe, and the main control valve is arranged on the main pipe to form the whole set of preheating device. The device is convenient to install, low in preheating difficulty, high in heating uniformity, efficiency and safety, adjustable in heating range and heating height, capable of improving the welding preheating quality of the spherical tank and widely applied to installation and manufacturing of the spherical tank.

Description

Technical Field

[0001] This utility model belongs to the field of pressure vessel welding preheating technology, specifically a preheating device suitable for welding spherical shell plates. Background Technology

[0002] Spherical containers, also known as spherical tanks, have a spherical shell. Compared to cylindrical containers, their main advantages are: uniform stress distribution; and, under the same wall thickness, spherical tanks have the highest load-bearing capacity. Under the same internal pressure, the required wall thickness for a spherical container is only half that of a cylindrical container of the same diameter and material (not considering corrosion allowance). They are an effective and economical pressure vessel for storing and transporting various gases, liquids, and liquefied gases. They are widely used in chemical, petroleum, oil refining, shipbuilding, and city gas industries. Due to the high parameterization of the containers (high pressure, high temperature, large diameter), spherical tanks have relatively thick walls. To ensure welding quality when the wall thickness exceeds a certain standard, preheating before welding and post-weld heating are necessary. Currently, common preheating methods for spherical tanks include fixed natural gas preheating devices or far-infrared heating plates. However, using fixed natural gas preheating devices results in low preheating efficiency and uneven preheating. Using far-infrared plates for preheating is not feasible due to the large diameter of spherical tanks (around 8000mm). This not only results in high procurement costs and installation difficulties, but also low heating efficiency and a high risk of safety accidents. Furthermore, neither fixed natural gas preheating devices nor infrared heating plates can meet the preheating needs of welding positions on spherical tanks of varying diameters and heights, exhibiting poor versatility. For example, Chinese utility model CN211759368 U (a welding preheating device) includes a base, gas pipe, support column, nozzle, and bracket, but this technology still has shortcomings: low preheating efficiency, uneven preheating temperature, and inability to meet the welding requirements of spherical tanks. Therefore, a preheating device suitable for welding spherical shell plates is proposed to address these issues. Utility Model Content

[0003] This invention addresses the shortcomings of existing technologies by providing a preheating device suitable for welding spherical shell plates, which reduces preheating difficulty, ensures uniform heating, and provides high efficiency and safety.

[0004] The technical solution of this utility model is as follows:

[0005] A preheating device for welding spherical shell plates includes a distribution pipe with an arc-shaped structure adapted to the outer contour of the spherical shell; several air outlets are symmetrically distributed on the inner side of the distribution pipe, and the air outlets are connected to the air outlet pipe in a through-seal connection; a ball valve is installed at the other end of the air outlet pipe, and a nozzle is installed at the front end of the ball valve; an air inlet pipe II is respectively located at the upper and lower sections on the outer side of the distribution pipe and is connected to the distribution pipe in a through-seal connection; the air inlet pipe II is connected to the air inlet pipe I in a through-seal connection; the air inlet pipe I is connected to the main air inlet pipe in a through-seal connection; and a main control valve is installed on the main pipe to form a complete preheating device.

[0006] The length of the nozzle is serialized.

[0007] The preheating device is mounted on a fixed bracket; the fixed bracket includes a fixed plate, which is fixedly connected to the base plate; the preheating device is adjustablely mounted on the fixed plate by U-bolts and nuts.

[0008] The bottom of the fixing plate is provided with a stiffening plate, which is fixedly connected to the fixing plate and the bottom plate respectively.

[0009] The base plate is square and 20mm thick.

[0010] This invention is easy to install, has low preheating difficulty, high heating uniformity, efficiency and safety, and adjustable heating range and height. It can improve the preheating quality of spherical tank welding and is widely used in its installation and manufacturing. Furthermore, this invention has advantages such as small size, light weight, and convenient installation and disassembly.

[0011] This invention is suitable for use in the manufacturing and repair of spherical tanks for preheating of welds, maintaining interpass temperature during welding, and postheating after welding. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model;

[0013] In the diagram: 1. Nozzle; 2. Ball valve; 3. Air outlet pipe; 4. Distribution pipe; 5. Air inlet pipe II; 6. Air inlet pipe I; 7. Main control valve; 8. Main air inlet pipe; 9. U-bolt; 10. Nut; 11. Fixing plate; 12. Rib plate; 13. Base plate. Detailed Implementation

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0015] like Figure 1As shown, a preheating device suitable for welding spherical shell plates includes a distribution pipe 4, which has an arc-shaped structure adapted to the outer contour of the spherical shell. Several air outlets are symmetrically distributed on the inner side of the distribution pipe 4, and these outlets are connected and sealed to an air outlet pipe 3. A ball valve 2 is installed at the other end of the air outlet pipe 3, and a nozzle 1 is installed at the front end of the ball valve 2. Air inlet pipes II 5 are respectively located at the upper and lower sections of the outer side of the distribution pipe 4 and are connected and sealed to the distribution pipe 4 to ensure more uniform air intake. Air inlet pipes II 5 are connected and sealed to air inlet pipe I 6, which is connected and sealed to a main air inlet pipe 8. A main control valve 7 is installed on the main air inlet pipe 8 to form the complete preheating device. The main control valve 7 can adjust the total air intake as needed. The valves added at the air outlet pipe 3 and the main air inlet pipe 8 can be opened and closed as needed to make the preheating temperature more precise and uniform.

[0016] Based on the structural characteristics of the spherical tank, this utility model adopts a three-stage distribution pipe to make the natural gas distribution more uniform; valves are installed before the nozzle and at the main pipe to make the temperature control more precise and safe.

[0017] The length of the nozzle 1 is serialized. According to the distance between the weld and the nozzle, nozzles of appropriate length are installed so that the distance between each nozzle and the weld is basically the same, so as to achieve uniform and controllable preheating temperature.

[0018] The preheating device is mounted on a fixed bracket; the fixed bracket includes a fixed plate 11, which is fixedly connected to the base plate 13; the preheating device is adjustablely mounted on the fixed plate 11 by U-bolts 9 and nuts 10. The fixed plate 11 has 6 sets of bolt holes. When the spherical tank is preheated, the position of the U-bolts on the fixed plate 11 is adjusted according to the diameter of the spherical tank and the preheating position to ensure that the preheating height meets the requirements.

[0019] The bottom of the fixing plate 11 is provided with a stiffening plate 12, which is fixedly connected to the fixing plate 11 and the bottom plate 13 respectively, and plays a role in strengthening the fixing plate.

[0020] The base plate 13 is square and 20mm thick. The side length can be increased as needed to make the preheating device more stable and prevent it from becoming unstable due to eccentricity.

[0021] The above description is only an application embodiment of this utility model, and should not be construed as limiting the scope of this utility model. Therefore, equivalent changes made in accordance with the scope of this utility model application shall still fall within the protection scope of this utility model.

Claims

1. A preheating device suitable for welding spherical shell plates, characterized in that, The device includes a distribution pipe (4), which has an arc-shaped structure and is adapted to the outer contour of the spherical shell. Several air outlets are symmetrically distributed on the inner side of the distribution pipe (4). The air outlets are connected to the air outlet pipe (3) in a through-sealed manner. A ball valve (2) is installed at the other end of the air outlet pipe (3). A nozzle (1) is installed at the front end of the ball valve (2). An air inlet pipe II (5) is respectively located at the upper and lower sections outside the distribution pipe (4) and is connected to the distribution pipe (4) in a through-sealed manner. The air inlet pipe II (5) is connected to the air inlet pipe I (6) in a through-sealed manner. The air inlet pipe I (6) is connected to the main air inlet pipe (8) in a through-sealed manner. A main control valve (7) is installed on the main pipe to form a complete preheating device.

2. The preheating device for welding spherical shell plates according to claim 1, characterized in that, The length of the nozzle (1) is serialized.

3. The preheating device for welding spherical shell plates according to claim 1, characterized in that, The preheating device is installed on a fixed bracket; the fixed bracket includes a fixed plate (11), which is fixed to the base plate (13); the preheating device is adjustablely installed on the fixed plate (11) by means of U-bolts (9) and nuts (10).

4. The preheating device for welding spherical shell plates according to claim 3, characterized in that, The bottom of the fixing plate (11) is provided with a stiffening plate (12), which is fixedly connected to the fixing plate (11) and the bottom plate (13) respectively.

5. A preheating device for welding spherical shell plates according to claim 4, characterized in that, The base plate (13) is square and has a thickness of 20mm.

Images