A pipe body plugging structure

Abstract

The utility model belongs to the technical field of pipeline plugging, specifically relates to a pipe body plugging structure for connecting with the end of pipe body, including the positioning pipe for inserting the inside of pipe body, the aperture of setting on the pipe wall of positioning pipe, the connecting pipe of setting on the end of positioning pipe, the inner chamber intercommunication with positioning pipe and located the end outside of pipe body, the gas duct of setting on the outer ring surface of connecting pipe and the inner chamber intercommunication with connecting pipe and the outer ring plate of setting at the connecting place of positioning pipe and connecting pipe and with the end surface of pipe body abutting, the clearance for the gas circulation is arranged between the inner wall of pipe body and the outer wall of positioning pipe. The utility model is applied to the bright annealing process and aims at the pipe body with big outer diameter, long pipe body and thick pipe wall, so as to reduce the protective gas circulation quantity in pipe body to reduce the cost, promote the temperature synchronization of inner wall and outer wall of pipe body, avoid the phenomenon of inner wall pitting.

Description

Technical Field

[0001] This utility model belongs to the field of pipeline plugging technology, specifically relating to a pipe body plugging structure. Background Technology

[0002] Bright annealing is an annealing process performed in a protective atmosphere. Its core objectives are to prevent metal oxidation, maintain metal luster, and eliminate work hardening. It is suitable for materials with high surface quality requirements, such as stainless steel, copper alloys, and titanium alloys.

[0003] Protective gases play a dual key role in bright annealing: reducing protection and efficient heat transfer medium.

[0004] When dealing with tubes with an outer diameter greater than 25mm and a length exceeding that of the furnace, the protective gas tends to flow in from the tube head and out from the tube tail due to the large cross-section. Since the tube tail is outside the furnace, a large amount of protective gas flows out along the entire tube, resulting in excessive consumption of mixed gas and a surge in production costs. This situation urgently needs to be addressed.

[0005] Sealing the pipe body is an effective method. For example, the document with authorization announcement number CN217081870U discloses a bevel gear driven expansion ring type steel pipe sealing head, which includes a moving pressure plate, a fixed plate, a rubber sealing ring, a moving shaft, and a bevel gear transmission mechanism for lifting the moving shaft to clamp the moving pressure plate and the fixed plate to achieve sealing. The bevel gear transmission mechanism drives the moving shaft to rotate upward, thereby lifting the moving pressure plate to clamp. The rubber sealing ring is squeezed and deformed under the action of the moving pressure plate and the fixed plate and then protrudes outward to achieve sealing, thereby achieving the performance of sealing the pipeline.

[0006] However, this structure is not suitable for bright annealing processes because the rubber sealing ring may vaporize directly in a furnace exceeding 1000 degrees Celsius. Furthermore, applying a fully sealed pipe directly to pipes with a wall thickness exceeding 2mm is also unsuitable, as the excessive temperature difference between the inside and outside of the pipe can lead to pitting corrosion on the inner wall.

[0007] Therefore, there is an urgent need for a pipe sealing structure that can be used in bright annealing processes and is suitable for pipes with large outer diameters, long pipes, and thick walls. Utility Model Content

[0008] To address the aforementioned problems, the purpose of this utility model is to provide a tube sealing structure applicable to bright annealing processes, specifically for tubes with large outer diameters, long lengths, and thick walls. This structure aims to reduce costs by decreasing the amount of protective gas flowing through the tube, while also promoting synchronized temperatures between the inner and outer walls to prevent pitting corrosion of the inner wall.

[0009] To achieve the above objectives, the technical solution of this utility model is as follows: A tube sealing structure for connecting to the end of a tube body includes a positioning tube for insertion into the tube body, an opening on the wall of the positioning tube, a connecting tube located on the end of the positioning tube, communicating with the inner cavity of the positioning tube and situated outside the end of the tube body, a gas duct on the outer annular surface of the connecting tube and communicating with the inner cavity of the connecting tube, and an outer annular plate located at the connection between the positioning tube and the connecting tube and abutting against the end surface of the tube body; a gap for gas flow is provided between the inner wall of the tube body and the outer wall of the positioning tube.

[0010] As a further preferred embodiment of this utility model, a constriction section is formed on the side of the connecting pipe away from the positioning pipe, and the minimum diameter of the constriction section is less than or equal to the inner diameter of the air intake pipe.

[0011] As a further preferred embodiment of this invention, a sealing plate is provided at the end of the connecting pipe away from the positioning pipe.

[0012] As a further preferred embodiment of this utility model, at least two oppositely arranged guide plates are provided on the inner wall of the positioning tube.

[0013] As a further preferred embodiment of this invention, the number of air intake tubes is multiple, and they are spaced apart on the outer ring surface of the connecting tube.

[0014] As a further preferred embodiment of the present invention, a single air intake tube extends radially along the connecting tube, and the diameter of the air intake tube gradually increases radially along the connecting tube.

[0015] As a further preferred embodiment of this utility model, the outer ring plate is fixedly connected to the end surface of the tube body.

[0016] As a further preferred embodiment of the present invention, the outer ring plate has at least one notch on its outer wall radially away from the positioning tube.

[0017] As a further preferred embodiment of this utility model, the positioning tube and the connecting tube are austenitic steel tubes, precipitation-hardening steel tubes, or high-alloy steel tubes.

[0018] As a further preferred embodiment of this utility model, the positioning tube, connecting tube, and air intake tube are integrally formed.

[0019] As a further preferred embodiment of this utility model, the outer ring plate is made of austenitic steel plate, precipitation hardening steel plate, or high alloy steel plate.

[0020] The beneficial effects of this utility model are: This invention not only reduces the consumption of protective gas, but also promotes the effective and uniform distribution of gas entering the tube within the narrow inner cavity, thereby improving the quality of the tube. Attached Figure Description

[0021] Appendix Figure 1 This is a schematic diagram of one structure of the present utility model.

[0022] Appendix Figure 2 This is a schematic diagram of the structure of this utility model, which replaces the connecting pipe inlet and adds a guide plate.

[0023] Appendix Figure 3 This is a cross-sectional view of the present invention from a side perspective.

[0024] Figure description: tube body a, positioning tube 21, opening 22, connecting tube 23, air intake tube 24, outer ring plate 25, guide plate 26; Contraction pipe section 231, sealing plate 232; Gap 251. Detailed Implementation

[0025] In the description of this utility model, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use, or the orientation or positional relationship that is commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance. In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] As attached Figure 1As shown, this utility model provides a pipe sealing structure that connects to the end of pipe a. The outer diameter of pipe a is ≥25mm, and the wall thickness of pipe a is ≥2mm. The limitation on pipe a is based on experiments in real-world scenarios. When the outer diameter of pipe a is less than 25mm and the wall thickness is less than 2mm, there is no need to add a pipe sealing structure. Under these conditions, the protective gas pipe a has a small diameter, making it difficult for large quantities to enter. Therefore, the consumption of protective gas is within an acceptable range. Furthermore, due to the small wall thickness, the temperature of the inner and outer walls of the pipe is more uniform, and pitting corrosion is less likely to occur inside the pipe.

[0028] Therefore, the tube sealing structure is used on an extra-long tube (length exceeding the furnace chamber) a with an outer diameter ≥25mm and a wall thickness ≥2mm. This is to ensure that there is protective gas in the inner cavity of tube a while reducing the amount of protective gas passing through tube a, thereby reducing the consumption of protective gas. At the same time, it is also necessary to ensure that the gas entering tube a can be effectively and evenly distributed in the extra-long inner cavity, thereby ensuring the uniformity of the quality of tube a and improving the quality.

[0029] Specifically, the tube sealing structure includes a positioning tube 21 inserted into the tube body a, an opening 22 on the wall of the positioning tube 21, a connecting tube 23 located on the end of the positioning tube 21, communicating with the inner cavity of the positioning tube 21 and located on the outer side of the end of the tube body a, an air duct 24 located on the outer annular surface of the connecting tube 23 and communicating with the inner cavity of the connecting tube 23, and an outer annular plate 25 located at the connection between the positioning tube 21 and the connecting tube 23 and abutting against the end surface of the tube body a; a gap for gas flow is provided between the inner wall of the tube body a and the outer wall of the positioning tube 21.

[0030] The positioning tube 21, connecting tube 23, air venting tube 24, and outer ring plate 25 are integrally formed and can be made of high-temperature resistant materials such as austenitic steel, precipitation hardening steel, and high-alloy steel. These steel materials have excellent high-temperature resistance, and austenitic steel is preferred because it offers high-temperature resistance (1150℃) while being less expensive and easier to use in actual production scenarios. (See attached...) Figure 3As shown, there are 2 to 6 gas inlet pipes 24, evenly distributed on the outer ring surface of the connecting pipe 23. Since the nozzles that spray protective gas are generally located on the upper inner wall and / or lower inner wall and / or front and rear inner side walls of the furnace (the left and right side walls are used for material inlet and outlet), the annular distribution of the pipes 24 ensures that when the tube body a is placed in the furnace for processing, the protective gas can enter the connecting pipe 23 through the gas inlet pipes 24 at various angles and positions and move into the positioning pipe 21. Finally, it flows out through the port of the positioning pipe 21 located inside the tube body a or the opening 22 on the pipe wall and contacts the inner wall of the tube body a, playing a role in heat transfer and reducing protection. Preferably, the diameter of the gas inlet pipe 24 gradually increases radially along the connecting pipe 23. The larger opening in the pipe structure, with a larger outer diameter and a smaller inner diameter, ensures sufficient contact area between the gas inlet pipe 24 and the external protective gas, facilitating the introduction of the protective gas into the tube body; the smaller outlet increases the speed at which the protective gas enters the connecting pipe 23, promoting gas flow and allowing it to quickly distribute into the depth of the pipe. The outer ring plate 25 primarily serves to seal the connection between the positioning tube 21 and the tube body a. Therefore, the outer ring plate 25 is fixedly connected to the end surface of the tube body a. Common methods such as welding can be used for this connection. Since the tube body a may rotate during transport, the diameter of the outer ring plate 25 is preferably less than or equal to the outer diameter of the tube body a and greater than its inner diameter. This ensures both effective sealing and prevents the outer ring plate 25 from protruding beyond the outer ring surface of the tube body a. Similarly, the end of the air venting tube 24 should also not protrude beyond the outer ring surface of the tube body a.

[0031] The gap between the inner wall of tube body a and the outer wall of positioning tube 21 should generally be controlled within the range of 1.0~2.0mm. This range is an effective range obtained through multiple experiments by the inventors. The purpose is twofold: first, to ensure that the gas can flow between the inner wall of tube body a and the outer wall of positioning tube 21 after flowing out through positioning tube 21, ensuring that all positions on the inner wall of tube body a can quickly and effectively contact the protective gas; second, to provide a accommodating space so that, in the event of thermal expansion and contraction during a series of processes such as high-temperature heating or cooling of tube body a or positioning tube 21, extreme situations such as positioning tube 21 tightly supporting tube body a or excessively large gaps between positioning tube 21 and tube body a will not occur.

[0032] As some preferred embodiments, see the appendix. Figure 1 As shown, a contraction section 231 is formed on the side of the connecting pipe 23 away from the positioning pipe 21. The end of the contraction section 231 away from the positioning pipe 21 has a minimum inner diameter, which is less than or equal to the inner diameter of the venting pipe 24. This design serves two purposes: first, to reduce the amount of protective gas accumulated in the connecting pipe 23; second, to ensure that the port of the connecting pipe 23 still has a certain degree of ventilation; and third, to limit the size of the minimum inner diameter to prevent a large amount of protective gas entering the connecting pipe 23 from overflowing from the contraction section 231.

[0033] As other preferred embodiments, see the appendix. Figure 2 As shown, a sealing plate 232 is provided at the end of the connecting pipe 23 away from the positioning pipe 21, and the sealing plate 232 is integrally formed with the connecting pipe 23.

[0034] As some preferred embodiments, see the appendix. Figure 2 and attached Figure 3 As shown, at least two opposing guide plates 26 are provided on the inner wall of the positioning tube 21. The main function of the guide plates 26 is to rapidly and regularly deliver the protective gas at the inlet of the positioning tube 21 into the interior of the positioning tube 21. The shape and structure of the guide plates 26 can be designed using existing common knowledge, and their number or length depends on the length of the positioning tube 21. That is, when the positioning tube 21 is long, the length of the guide plates 26 can be increased, or multiple sets of guide plates 26 can be provided, distributed at intervals along the length direction of the positioning tube 21.

[0035] As some preferred embodiments, see the appendix. Figure 2 As shown, the outer ring plate 25 has at least one notch 251 on its outer wall radially away from the positioning tube 21. The notch 251 is provided to facilitate the quick positioning and cutting of the tube body a by a cutting device after the bright annealing process is completed, thereby facilitating the separation of the tube body a from the tube sealing structure.

[0036] The inventors' experimental data are shown in the table below:

[0037] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A pipe sealing structure for connecting to the end of a pipe (a); characterized in that: The tube includes a positioning tube (21) for insertion into the tube body (a), an opening (22) on the wall of the positioning tube (21), a connecting tube (23) on the end of the positioning tube (21), communicating with the inner cavity of the positioning tube (21) and located on the outer side of the end of the tube body (a), an air duct (24) on the outer ring surface of the connecting tube (23) and communicating with the inner cavity of the connecting tube (23), and an outer ring plate (25) at the connection between the positioning tube (21) and the connecting tube (23) and abutting against the end surface of the tube body (a); a gap for gas flow is provided between the inner wall of the tube body (a) and the outer wall of the positioning tube (21).

2. The pipe sealing structure according to claim 1, characterized in that: A contraction tube section (231) is formed on the side of the connecting tube (23) away from the positioning tube (21). The end of the contraction tube section (231) away from the positioning tube (21) has a minimum inner diameter, and the minimum inner diameter is less than or equal to the inner diameter of the air intake tube (24).

3. The pipe sealing structure according to claim 1, characterized in that: A sealing plate (232) is provided at the end of the connecting pipe (23) away from the positioning pipe (21).

4. The pipe sealing structure according to claim 1, characterized in that: At least two oppositely arranged guide plates (26) are provided on the inner wall of the positioning tube (21).

5. The pipe sealing structure according to claim 1, characterized in that: There are multiple air intake tubes (24), which are distributed at intervals on the outer ring surface of the connecting tube (23).

6. The pipe sealing structure according to claim 1, characterized in that: Each of the air intake tubes (24) extends radially along the connecting tube (23), and the diameter of the air intake tube (24) gradually increases radially along the connecting tube (23).

7. The pipe sealing structure according to claim 1, characterized in that: The outer ring plate (25) is fixedly connected to the end surface of the tube body (a).

8. A pipe sealing structure according to claim 7, characterized in that: The outer ring plate (25) has at least one notch (251) on its outer wall radially away from the positioning tube (21).

9. A pipe sealing structure according to claim 1, characterized in that: The positioning tube (21) and connecting tube (23) are austenitic steel tubes, precipitation hardening steel tubes, or high alloy steel tubes.

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