Pipeline dynamic sealing structure suitable for complex working condition environment

Abstract

The invention relates to the technical field of pipeline connecting equipment, in particular to a pipeline dynamic sealing structure suitable for a complex working condition environment, which comprises a fixed pipeline, a sliding pipeline and a connecting pipeline which are coaxially arranged, and the fixed pipeline, the sliding pipeline and the connecting pipeline are sealed through flexible graphite packing sealing rings. Through the fixed pipeline, the sliding pipeline and the connecting pipeline which are coaxially connected, a specific pipeline coaxial sliding structure is formed, and the sliding pipeline can be driven by an external pipeline to freely slide on the outer surface of the fixed pipeline in the axial direction; the pipeline connection flexibility and the displacement compensation capacity of the pipeline connection in practical application are greatly improved, and friction reduction treatment is carried out between the sliding pipeline and the fixed pipeline; the inner-stage flexible graphite packing sealing ring and the outer-stage flexible graphite packing sealing ring are arranged in a matched mode, so that the friction coefficient between the inner-stage flexible graphite packing sealing ring and the outer-stage flexible graphite packing sealing ring is reduced, sliding is smoother, meanwhile, an efficient sealing system is formed, and efficient sealing under the complex dynamic condition is achieved.

Description

Technical Field

[0001] This application relates to the field of pipeline connection equipment technology, and in particular to a dynamic sealing structure for pipelines suitable for complex working conditions. Background Technology

[0002] Pipeline connections and their sealing structures play a crucial role in many industrial sectors, particularly in energy, petrochemicals, power, aerospace, shipbuilding, heating networks, and metallurgy. However, with the increasing demands of industrial production on operating environments, especially the emergence of high-temperature, high-pressure, corrosive media, and high-frequency deformation environments, traditional pipeline connection structures and sealing technologies are increasingly revealing their shortcomings.

[0003] In specific industrial production and testing processes, axial deformation of pipelines to varying degrees due to thermal expansion and contraction, pressure fluctuations, or other environmental factors is an unavoidable phenomenon. However, commonly used pipeline compensation solutions, such as expansion joints and sliding compensators, typically suffer from limited displacement compensation range, unstable sealing performance, and high maintenance difficulty. For example, the compensation capacity of expansion joints is limited by their own design structure, and the compensation amount is generally a pre-set fixed value. When the deformation in the actual pipeline environment exceeds the design allowable range of the expansion joint, it cannot effectively compensate for the additional displacement, easily causing stress concentration at pipeline connections, and even leading to pipeline structural damage and safety accidents. Furthermore, since expansion joints are usually designed and installed in a one-time process, if the actual displacement exceeds the design capacity, temporary adjustments are not possible; the problem can only be solved by replacing the entire unit. This significantly increases the maintenance cost and difficulty of the project, especially under complex operating conditions such as high temperature and high pressure. Summary of the Invention

[0004] This application provides a pipeline dynamic sealing structure suitable for complex working conditions, in order to solve the problems of unstable sealing performance and high maintenance difficulty of traditional pipeline connection structures and sealing technologies under complex working conditions such as high temperature and high pressure.

[0005] This application provides a pipeline dynamic sealing structure suitable for complex working conditions, including: Coaxial fixed pipelines, sliding pipelines, and connecting pipelines; One end of the fixed pipeline is connected to an external pipeline system, and the other end extends into the interior of the sliding pipeline. The sliding pipeline is slidably fitted onto the outer surface of the fixed pipeline via a first connecting flange. The connecting pipe can be fixedly connected to one end of the sliding pipe by a corresponding bolt; The fixed pipeline, the sliding pipeline, and the connecting pipeline are sealed by a flexible graphite packing sealing ring.

[0006] Preferably, the outer surface of the end of the fixed pipe that is inserted into the sliding pipe is treated to reduce friction.

[0007] Preferably, the flexible graphite packing sealing ring includes an inner flexible graphite packing sealing ring and an outer flexible graphite packing sealing ring. The inner flexible graphite packing sealing ring is disposed at the radial gap between the fixed pipeline and the sliding pipeline, and the outer flexible graphite packing sealing ring is disposed at the radial gap between the connecting pipeline and the external pipeline.

[0008] Preferably, the sliding pipeline is tightly connected to the first connecting flange by screws, and a first annular pre-tightening groove for installing the flexible graphite packing sealing ring is also provided on the inner wall of the sliding pipeline near the fixed pipeline. The inner flexible graphite packing sealing ring is pressed and fixed in the first annular pre-tightening groove by the first connecting flange.

[0009] Preferably, the external pipe is inserted into the end of the connecting pipe away from the sliding pipe via a second connecting flange, and a second annular pre-tightening groove for installing the flexible graphite packing sealing ring is correspondingly provided on the inner wall of the end of the connecting pipe near the sliding pipe. The outer flexible graphite packing sealing ring is pressed and fixed in the second annular pre-tightening groove by the second connecting flange.

[0010] Preferably, the connecting pipeline includes a connecting end connected to the sliding pipeline and a plug-in end for inserting the external pipeline; The connecting end is a closed ring structure that can close the sliding pipeline, and can be fixedly connected to the sliding pipeline by the corresponding bolts. The plug end is fixedly set on the side of the connecting end away from the sliding pipeline. One side of the plug end is also provided with a plug interface for plugging into the external pipe, and the plug interface extends through to the other side of the connector.

[0011] Preferably, the sliding pipeline has a two-section spliced ​​structure.

[0012] Preferably, the sliding conduit includes a first splice section for connecting to the first connecting flange and a second splice section for connecting to the connecting conduit.

[0013] Preferably, one end of both the first splicing segment and the second splicing segment is provided with an installation ring for splicing, and the first splicing segment and the second splicing segment can be fixedly connected by corresponding bolts; The first annular pre-tightening groove is located at one end of the first splicing section near the fixed pipeline, and the end of the second splicing section away from the mounting ring can be connected to the connecting pipeline by the corresponding bolts.

[0014] Preferably, the sliding conduit is an integral structure; One end of the sliding pipe near the fixed pipe is connected to the first connecting flange by the screw, and the other end is connected to the connecting pipe by the corresponding bolt.

[0015] The beneficial effects of this application are as follows: The pipeline dynamic sealing structure applicable to complex working conditions of this application forms a specific pipeline coaxial sliding structure by coaxially connecting a fixed pipeline, a sliding pipeline, and a connecting pipeline. This allows the sliding pipeline to slide freely along the axial direction on the outer surface of the fixed pipeline under the influence of an external pipeline, greatly improving the flexibility of pipeline connection and its displacement compensation capability in practical applications.

[0016] Furthermore, by implementing friction reduction treatment between the sliding and fixed pipelines, and with the addition of inner and outer flexible graphite packing sealing rings, the friction coefficient between the two is reduced, making the sliding smoother while forming a highly efficient sealing system, thus achieving efficient sealing under complex dynamic conditions.

[0017] In particular, by adopting a universal flange connection method and a modular layout, the result is easier to install, disassemble and maintain on site. Compared with existing complex pipeline compensation devices, it reduces production costs while improving the convenience of installation and maintenance. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the overall structure of a pipeline dynamic sealing structure suitable for complex working conditions, provided in an embodiment of this application; Figure 2 Examples of this application Figure 1 Schematic diagram of the cross section at point BB; Figure 3 This is a schematic diagram showing the connection between the pipe dynamic sealing structure and the external pipe in an embodiment of this application; Figure 4This is another schematic diagram of the splicing of the sliding pipe in an embodiment of this application; Figure 5 This is another structural schematic diagram of the sliding pipe provided in an embodiment of this application.

[0020] Figure label: 1. Fixed pipeline; 2. First connecting flange; 3. Sliding pipeline; 30. First annular pre-tightening groove; 31. First splicing section; 32. Second splicing section; 4. Connecting pipeline; 5. Second connecting flange; 6. External pipeline; 7. Inner flexible graphite packing sealing ring; 8. Outer flexible graphite packing sealing ring. Detailed Implementation

[0021] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] The following is combined with Figures 1-5 This application describes a pipeline dynamic sealing structure suitable for complex working conditions, as provided in the embodiments of this application.

[0023] Please refer to Figure 1 and Figure 2 ,like Figure 1 and Figure 2 As shown, where, Figure 1 This is a schematic diagram of the overall structure of a pipeline dynamic sealing structure suitable for complex working conditions, provided in an embodiment of this application. Figure 2 Examples of this application Figure 1 Schematic diagram of the cross section at point BB; The pipeline dynamic sealing structure applicable to complex working conditions provided in this application embodiment includes a fixed pipeline 1, a sliding pipeline 3, and a connecting pipeline 4 arranged coaxially. The fixed pipeline 1 is used to connect to an external pipeline system. One end of the fixed pipeline 1 is connected to the input or output end of the external pipeline system, and the other end extends into the interior of the sliding pipeline 3. The sliding pipeline 3 is slidably sleeved on the outer surface of the fixed pipeline 1 through a first connecting flange 2, so that it can slide on the outer surface of the fixed pipeline 1 under the push of the external pipeline 6 to compensate for the displacement of the pipeline system due to thermal expansion. The connecting pipeline 4 can be fixedly connected to one end of the sliding pipeline 3 by corresponding bolts. It is located at the end of the sliding pipeline 3 away from the fixed pipeline 1. The fixed pipeline 1, the sliding pipeline 3, and the connecting pipeline 4 are sealed by corresponding flexible graphite packing sealing rings to prevent leakage at their connection.

[0024] By coaxially connecting the fixed pipe 1, the sliding pipe 3, and the connecting pipe 4, a specific coaxial sliding structure is formed, allowing the sliding pipe 3 to slide freely along the axial direction on the outer surface of the fixed pipe 1 under the influence of the external pipe 6. This greatly improves the flexibility of the pipe connection and its displacement compensation capability in practical applications.

[0025] By adopting a universal flange connection method and a modular layout, the result is easier to install, disassemble and maintain on site. Compared with existing complex pipeline compensation devices, it reduces production costs while improving the convenience of installation and maintenance.

[0026] In some specific embodiments, the outer surface of the end of the fixed pipe 1 that is inserted into the sliding pipe 3 is treated to reduce friction.

[0027] The friction coefficient between the fixed pipe 1 and the sliding pipe 3 is reduced by performing friction reduction treatment on the outer surface of the fixed pipe 1. For example, a low-friction coefficient coating is applied to the outer surface of the fixed pipe 1 to form a corresponding coating layer, or the outer surface of the fixed pipe 1 is finely machined by a three-stage processing process using "gradient surface engineering", or the corresponding material with a smooth surface and low friction coefficient is directly used for casting. The friction reduction treatment here must be a treatment that can still work normally under high temperature, high pressure or chemical corrosion conditions. Fixed pipe 1 is a tubular structure that can be connected to the output or input end of an external piping system, or it can be directly the input or output end of an external piping system. The selected friction reduction treatment method can be selected according to the actual situation of fixed pipe 1. For example, when fixed pipe 1 is cast from common materials or is directly the input or output end of an external piping system, polytetrafluoroethylene (PTFE) with low friction coefficient can be coated at the contact point between fixed pipe 1 and sliding pipe 3 to form a PTFE composite coating. Since the friction coefficient of polytetrafluoroethylene is between 0.04 and 0.08, and it is resistant to chemical corrosion and has an applicable temperature range of 200℃-260℃, it can effectively reduce the friction coefficient between the two while meeting the requirements of high temperature or corrosion scenarios under complex working conditions.

[0028] Furthermore, by performing friction reduction treatment on the sliding pipe 3 and the fixed pipe 1, and with the installation of inner and outer two-stage flexible graphite packing sealing rings, the friction coefficient between the two is reduced, making the sliding smoother and forming a highly efficient sealing system, thus achieving efficient sealing under complex dynamic conditions.

[0029] Please continue reading. Figure 3 ,like Figure 3 As shown, it is a schematic diagram of the connection between the pipeline dynamic sealing structure and the external pipeline in an embodiment of this application; In some specific embodiments, the flexible graphite packing seal ring includes an inner flexible graphite packing seal ring 7 and an outer flexible graphite packing seal ring 8. The inner flexible graphite packing sealing ring 7 is installed at the radial gap between the fixed pipeline 1 and the sliding pipeline 3, and the outer flexible graphite packing sealing ring 8 is installed at the radial gap between the connecting pipeline 4 and the external pipeline 6.

[0030] Because of its excellent high-temperature and high-pressure resistance, as well as good elasticity and filling performance, the flexible graphite packing sealing ring can adjust its shape in real time during axial movement to continuously ensure the tightness of the sealing surface. By setting the outer flexible graphite packing sealing ring 8 and the inner flexible graphite packing sealing ring 7 between the corresponding two pipe gaps through two corresponding connecting flanges, it can efficiently and dynamically seal the gaps between different pipe diameters, forming an efficient and reliable sealing system. This ensures that the pipeline system can be sealed for a long time under complex dynamic conditions, which significantly improves the sealing reliability of the pipeline under long-term complex working conditions.

[0031] In some specific embodiments, the sliding pipe 3 is tightly connected to the first connecting flange 2 by screws, and the inner wall of the sliding pipe 3 near the fixed pipe 1 is also provided with a first annular pre-tightening groove 30 for installing a flexible graphite packing sealing ring. The inner flexible graphite packing sealing ring 7 is pressed and fixed in the first annular pre-tightening groove 30 by the first connecting flange 2. The inner flexible graphite packing sealing ring 7 can effectively fill the radial gap, ensuring that the medium in the pipeline will not leak during axial sliding, thereby forming a precise coaxial sliding fit between the sliding pipeline 3 and the fixed pipeline 1.

[0032] In some specific embodiments, the external pipe 6 is inserted into the end of the connecting pipe 4 away from the sliding pipe 3 via the second connecting flange 5, and the inner wall of the connecting pipe 4 near the sliding pipe 3 is provided with a second annular pre-tightening groove 40 for installing the flexible graphite packing sealing ring. The outer flexible graphite packing sealing ring 8 is pressed and fixed in the second annular pre-tightening groove 40 by the second connecting flange 5. The outer flexible graphite packing sealing ring 8 further enhances the overall sealing performance and further reduces the possibility of leakage of the medium in the pipeline system from the connecting pipe, effectively preventing the medium leakage that may occur in the pipeline system under high pressure and high temperature conditions.

[0033] In some specific embodiments, the connecting pipe 4 includes a connecting end connected to the sliding pipe 3 and a plug-in end for plugging into the external pipe 6; The connecting end is a closed ring structure that can close the sliding pipe 3, and can be fixedly connected to the sliding pipe 3 by corresponding bolts. The plug end is fixedly set on the side of the connecting end away from the sliding pipe 3. One side of the connector is also provided with a connector for connecting an external pipe 6, which extends to the other side of the connector.

[0034] In some specific embodiments, the sliding pipe 3 is a two-section spliced ​​structure.

[0035] Specifically, the sliding pipe 3 includes a first splice section 31 for connecting to the first connecting flange 2 and a second splice section 32 for connecting to the connecting pipe 4.

[0036] Specifically, one end of the first splicing segment 31 and the second splicing segment 32 is provided with an installation ring for splicing, and the first splicing segment 31 and the second splicing segment 32 can be fixedly connected by corresponding bolts; The first annular pre-tightening groove 30 is located at the end of the first splicing section 31 near the fixed pipeline 1, and the end of the second splicing section 32 away from the mounting ring can be connected to the connecting pipeline 4 by corresponding bolts.

[0037] In this embodiment, the opening diameter of the plug is smaller than the opening diameter of the fixed pipe 1, and the opening diameter of the plug and the opening diameter of the fixed pipe 1 should be compatible with the diameter of the external pipe 6 or the corresponding pipe system output or input end to be plugged in, so that the structure can provide corresponding connection and sealing between pipes or pipes of different diameters in the pipe system, thereby providing an efficient dynamic sealing effect in the connection section between different pipe diameters in the pipe system. Please continue reading. Figure 4 ,like Figure 4 As shown, this is another schematic diagram of the splicing of the sliding pipe in an embodiment of this application; For example, when the two pipe sections to be connected are both output or input ends of the corresponding piping system, or when the two pipe sections to be connected are both external pipes 6 with a larger diameter, the sliding connection pipe can be set as a corresponding connection pipe formed by symmetrical splicing of two first splicing sections 31, so that both ends of it can be connected to the input or output end of the corresponding piping system, or connected to the external pipe 6 with a larger diameter through the corresponding flange interface, so as to provide the corresponding connection and sealing. Similarly, when the two pipe sections to be connected are both external pipes 6 with smaller diameters, the sliding connection pipe can be set as a corresponding connection pipe formed by symmetrical splicing of two first splicing sections 31, so that the two external pipe sections 6 with corresponding diameters can be connected to their corresponding ends by inserting the second connection flange 5, providing them with the corresponding connection and sealing.

[0038] Please continue reading. Figure 5 ,like Figure 5 As shown, this is another structural schematic diagram of the sliding pipe provided in an embodiment of this application; In some specific embodiments, the sliding pipe 3 is an integral structure; One end of the sliding pipe 3 near the fixed pipe 1 is connected to the first connecting flange 2 by screws, and the other end is connected to the connecting pipe 4 by corresponding bolts. By setting the sliding pipes 3 as an integral structure, its sealing performance is further increased, and the possibility of leakage of the medium in the pipe from the splice is avoided.

[0039] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0042] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0043] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A dynamic sealing structure for pipelines suitable for complex working conditions, characterized in that, include: The fixed pipeline (1), the sliding pipeline (3), and the connecting pipeline (4) are arranged coaxially. One end of the fixed pipeline (1) is connected to the external pipeline system, and the other end extends into the interior of the sliding pipeline (3). The sliding pipeline (3) is slidably sleeved on the outer surface of the fixed pipeline (1) through the first connecting flange (2). The connecting pipe (4) can be fixedly connected to one end of the sliding pipe (3) by corresponding bolts; The fixed pipeline (1), the sliding pipeline (3), and the connecting pipeline (4) are sealed by a flexible graphite packing sealing ring.

2. The pipeline dynamic sealing structure suitable for complex working conditions according to claim 1, characterized in that, The outer surface of the fixed pipe (1) that is inserted into the sliding pipe (3) is treated to reduce friction.

3. The pipeline dynamic sealing structure suitable for complex working conditions according to claim 2, characterized in that, The flexible graphite packing seal ring includes an inner flexible graphite packing seal ring (7) and an outer flexible graphite packing seal ring (8). The inner flexible graphite packing sealing ring (7) is disposed at the radial gap between the fixed pipeline (1) and the sliding pipeline (3), and the outer flexible graphite packing sealing ring (8) is disposed at the radial gap between the connecting pipeline (4) and the external pipeline (6).

4. The pipeline dynamic sealing structure suitable for complex working conditions according to claim 3, characterized in that, The sliding pipe (3) is tightly connected to the first connecting flange (2) by screws. The inner wall of the sliding pipe (3) near the fixed pipe (1) is also provided with a first annular pre-tightening groove (30) for installing the flexible graphite packing sealing ring. The inner flexible graphite packing sealing ring (7) is pressed and fixed in the first annular pre-tightening groove (30) by the first connecting flange (2).

5. The pipeline dynamic sealing structure suitable for complex working conditions according to claim 4, characterized in that, The external pipe (6) is inserted into the end of the connecting pipe (4) away from the sliding pipe (3) through the second connecting flange (5), and the inner wall of the connecting pipe (4) near the sliding pipe (3) is provided with a second annular pre-tightening groove (40) for installing the flexible graphite packing sealing ring. The outer flexible graphite packing sealing ring (8) is pressed and fixed in the second annular pre-tightening groove (40) by the second connecting flange (5).

6. The pipeline dynamic sealing structure suitable for complex working conditions according to claim 5, characterized in that, The connecting pipe (4) includes a connecting end connected to the sliding pipe (3) and a plug-in end for plugging into the external pipe (6); The connecting end is a closed ring structure that can close the sliding pipe (3), and can be fixedly connected to the sliding pipe (3) by the corresponding bolts. The plug end is fixedly set on the side of the connecting end away from the sliding pipe (3). One side of the plug end is also provided with a plug interface for plugging into the external pipe (6), and the plug interface extends through to the other side of the connection end.

7. The pipeline dynamic sealing structure suitable for complex working conditions according to claim 6, characterized in that, The sliding pipeline (3) is a two-section splicing structure.

8. The pipeline dynamic sealing structure suitable for complex working conditions according to claim 7, characterized in that, The sliding pipeline (3) includes a first splice section (31) for connecting to the first connecting flange (2) and a second splice section (32) for connecting to the connecting pipeline (4).

9. The pipeline dynamic sealing structure suitable for complex working conditions according to claim 8, characterized in that, One end of the first splicing segment (31) and the second splicing segment (32) is provided with an installation ring for splicing, and the first splicing segment (31) and the second splicing segment (32) can be fixedly connected by corresponding bolts; The first annular pre-tightening groove (30) is located at one end of the first splicing section (31) near the fixed pipeline (1), and the end of the second splicing section (32) away from the mounting ring can be connected to the connecting pipeline (4) by the corresponding bolt.

10. The pipeline dynamic sealing structure suitable for complex working conditions according to claim 6, characterized in that, The sliding pipeline (3) is an integral structure; The sliding pipe (3) is connected to the first connecting flange (2) at one end near the fixed pipe (1) by the screw, and the other end is connected to the connecting pipe (4) by the corresponding bolt.

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