Composite corrugated compensator inner wall protection structure, corrugated compensator and design method

Abstract

This invention relates to a composite bellows compensator inner wall protection structure, the bellows compensator itself, and its design method. The inner wall protection structure is a composite layer structure, including an anti-erosion functional layer, a transition fixing layer, and a bellows substrate. The anti-erosion functional layer includes an outer ceramic plate and an inner ceramic plate. The transition fixing layer includes an outer ring plate and an inner ring plate, which are spaced radially and staggered axially, forming a non-rigid connection structure. The inner walls of the outer and inner ring plates are respectively provided with the outer and inner ceramic plates. The bellows substrate is made of thin metal sheet and has a corrugated structure, used to realize the displacement compensation function of the bellows compensator. One end of the outer ring plate is fixedly connected to the inner wall of the bellows substrate. This invention effectively improves the wear resistance, deformation coordination, and overall operational reliability of the bellows compensator under complex working conditions by constructing a composite protection system on the inner wall of the bellows that combines high erosion resistance and good deformation adaptability.

Description

Technical Field

[0001] This invention relates to the field of pipeline engineering technology, specifically to a composite corrugated compensator inner wall protection structure, a corrugated compensator, and a design method. Background Technology

[0002] Bellows compensators (also known as bellows expansion joints) are key flexible components in pipeline systems, widely used in power, petrochemical, and metallurgical industries to absorb axial, lateral, and angular displacements caused by thermal expansion and contraction, equipment vibration, or installation deviations, thereby reducing additional stress on the pipeline system and improving operational safety. The core component of a bellows compensator is the bellows, typically made of thin metal sheets processed into a corrugated structure. It achieves excellent flexible compensation capabilities through corrugation deformation, compensating for pipeline displacement while withstanding internal pressure. In practical engineering applications, when the medium transported in the pipeline contains solid particles, or when the medium has characteristics such as high flow velocity, high temperature, or high corrosiveness, the medium will continuously erode and wear the inner wall of the bellows. This can easily lead to localized thinning of the bellows wall, a decrease in pressure-bearing capacity, and the induction of fatigue cracks in stress concentration areas such as troughs, thus significantly shortening the service life of the bellows compensator.

[0003] To address the aforementioned issues, various internal wall protection approaches have been proposed in existing technologies. For example, improving corrosion resistance by integrally lining the inner wall of the bellows with plastic or composite materials, or enhancing wear resistance through welded inner lining plates or double-wall structures. Other technologies utilize coaxial guide tubes or protective sleeves inside the bellows to allow the medium to flow around it, reducing direct erosion of the bellows' inner wall. Furthermore, some solutions focus on the external structure of the compensator, improving overall operating conditions through vibration reduction, sealing, or external pressure balancing. However, these solutions generally have limitations: integral linings or rigid inner lining structures struggle to adapt to the repeated flexible deformation of the bellows, easily leading to cracking, detachment, or additional stress; built-in guide structures increase flow resistance and structural complexity, potentially causing blockages or vibrations in particulate media conditions; and external improvements cannot fundamentally solve the problem of erosion and wear on the bellows' inner wall. Therefore, existing technologies still face problems in protecting the inner wall of corrugated compensators, such as difficulty in balancing wear resistance and deformation adaptability, and difficulty in effectively alleviating interface stress concentration. There is an urgent need for a technical solution that can balance the inner wall protection effect and the deformation capacity of the corrugated pipe under complex working conditions. Summary of the Invention

[0004] To address the aforementioned deficiencies in existing technologies, this invention provides a composite corrugated compensator inner wall protection structure, a corrugated compensator, and a design method. By constructing a composite protection system on the inner wall of the corrugated pipe that combines high erosion resistance with good deformation adaptability, and with reasonable material matching and structural design, the wear resistance, deformation coordination, and overall operational reliability of the corrugated compensator under complex working conditions can be effectively improved.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A composite corrugated compensator inner wall protection structure is disclosed, comprising a composite layer structure including an anti-erosion functional layer, a transition fixing layer, and a bellows substrate. The anti-erosion functional layer, which is in direct contact with the medium flow, includes an outer ceramic plate and an inner ceramic plate. The transition fixing layer, serving as the fixing substrate for the anti-erosion functional layer, is disposed outside the anti-erosion functional layer. The transition fixing layer includes an outer ring plate and an inner ring plate, which are radially spaced and axially misaligned, forming a non-rigid connection structure. The inner walls of the outer and inner ring plates are respectively provided with the outer and inner ceramic plates. The bellows substrate is made of thin metal sheet and has a corrugated structure, used to realize the displacement compensation function of the corrugated compensator. One end of the outer ring plate is fixedly connected to the inner wall of the bellows substrate.

[0007] Preferably, the outer ceramic plate and the inner ceramic plate are made of ceramic matrix material, which has higher hardness and wear resistance than the transition fixing layer, and are divided into multiple independent small block units.

[0008] Preferably, the small units of the outer ceramic plate and the inner ceramic plate are fixed to the inner walls of the outer ring plate and the inner ring plate by spot welding, plug welding or brazing.

[0009] Preferably, the outer ring plate and the inner ring plate are made of ordinary carbon steel or thin metal plates with excellent weldability and a certain degree of toughness.

[0010] On the other hand, the present invention also discloses a corrugated compensator, including the above-mentioned composite corrugated compensator inner wall protection structure. The corrugated compensator further includes an upper connecting plate, an intermediate ring plate and a lower connecting plate. The corrugated pipe base includes a first corrugated pipe section and a second corrugated pipe section arranged sequentially along the axial direction. The first corrugated pipe section is located between the upper connecting plate and the intermediate ring plate, and the second corrugated pipe section is located between the intermediate ring plate and the lower connecting plate.

[0011] Preferably, the first corrugated pipe section and the second corrugated pipe section are respectively connected to the upper connecting plate, the intermediate ring plate and the lower connecting plate by welding.

[0012] Preferably, the inner ring plate corresponding to the first corrugated pipe section is installed and fixed by the intermediate ring plate, and the inner ring plate corresponding to the second corrugated pipe section is installed and fixed by the lower connecting plate, so that the inner ring plate is axially misaligned with the outer ring plate.

[0013] Preferably, the upper connecting plate and the lower connecting plate are respectively provided with connecting holes, and bolts are installed through the connecting holes to connect with the pipe.

[0014] Preferably, the upper connecting plate extends an upper connecting ring towards the lower connecting plate, and several upper square blocks are arranged on the outer side of the upper connecting ring. The middle connecting plate extends a middle connecting ring on both sides, and several middle square blocks are arranged on the outer side of the middle connecting ring. The lower connecting plate extends a lower connecting ring towards the upper connecting plate, and several lower square blocks are arranged on the outer side of the lower connecting ring. Through holes are provided in the upper square blocks, middle square blocks, and lower square blocks. A threaded rod passes through the through holes and cooperates with a nut to achieve axial locking.

[0015] Furthermore, this invention also discloses a design method for designing the inner wall protection structure of the aforementioned composite corrugated compensator, comprising the following steps:

[0016] S1, Operating Parameter Analysis: Obtain the operating parameters of the corrugated compensator, including the medium composition, medium flow rate, operating temperature, particle size and erosion intensity in the medium, and determine the erosion level that the anti-erosion functional layer needs to withstand based on the operating parameters.

[0017] S2, Anti-erosion functional layer design: Select the material type of the anti-erosion functional layer according to the erosion level, and design the anti-erosion functional layer as a segmented structure composed of an outer ceramic plate and an inner ceramic plate to adapt to the deformation characteristics of the corrugated pipe substrate;

[0018] S3, Transition fixing layer structure matching: Based on the material properties of the corrugated pipe substrate and the axial displacement compensation amount, the material of the transition fixing layer is determined, and the transition fixing layer is designed as an outer ring plate and an inner ring plate, so that the outer ring plate and the inner ring plate form a gap in the radial direction and a misaligned arrangement in the axial direction;

[0019] S4, Non-rigid connection relationship determined: The outer ring plate is fixedly connected to the inner wall of the corrugated pipe base, so that the outer ring plate deforms synchronously with the corrugated pipe base; the inner ring plate is installed and fixed through a connecting structure, so that the inner ring plate maintains an axially misaligned state relative to the outer ring plate, thereby forming a non-rigid connection structure;

[0020] S5, Overall Structure Verification and Validation: Based on the combined structure of the anti-erosion functional layer, transition fixing layer and corrugated pipe substrate, the deformation coordination, welding reliability and erosion durability of the inner wall protection structure are verified, and the design of the inner wall protection structure of the composite corrugated compensator is completed.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) This invention achieves an inner wall protection system that balances high erosion resistance and good deformation adaptability by constructing a composite layer structure on the inner wall of the bellows substrate, consisting of an anti-erosion functional layer, a transition fixing layer, and the bellows substrate. Unlike existing single-material protection or rigid lining solutions, this invention, through functional layering and structural matching design, enables erosion loads and deformation stresses to be transferred and dispersed step by step between different structural layers, thereby effectively improving the overall reliability of the bellows compensator under complex working conditions.

[0023] (2) The anti-erosion functional layer in this invention is composed of an outer ceramic plate and an inner ceramic plate, which are in direct contact with the medium flow. The high hardness and high wear resistance of the ceramic matrix material are used to resist the erosion and wear caused by solid particles and high-speed flow in the medium on the inner wall. At the same time, the anti-erosion functional layer is divided into multiple independent small units, so that each small unit can generate a small relative displacement or rotation when the bellows matrix undergoes axial, radial or angular deformation, thereby releasing local stress and avoiding cracking or peeling of the overall brittle structure during repeated deformation.

[0024] (3) The transition fixing layer of the present invention is made of a metal material with good toughness and excellent weldability, including an outer ring plate and an inner ring plate. The outer ring plate and the inner ring plate are separated in the radial direction and staggered in the axial direction to form a non-rigid connection structure. On the one hand, the transition fixing layer, as the fixing substrate of the anti-erosion functional layer, buffers and disperses the local impact load from the small blocks of the anti-erosion functional layer through its good plastic deformation ability; on the other hand, the staggered arrangement of the outer ring plate and the inner ring plate effectively changes the stress transmission path between layers, causing the stress to be deflected and redistributed inside the transition fixing layer, thereby significantly reducing the stress peak value directly transmitted to the bellows substrate and reducing the risk of stress concentration at the interface.

[0025] (4) This invention divides the corrugated pipe substrate into a first corrugated pipe segment and a second corrugated pipe segment connected sequentially along the axial direction. The segmented connection is achieved through an upper connecting plate, an intermediate ring plate, and a lower connecting plate, so that the displacement compensation process of the corrugated pipe is reasonably distributed among different corrugated pipe segments, avoiding excessive concentrated deformation of a single corrugated pipe segment under large displacement conditions. In this structure, the intermediate ring plate provides a stable installation reference for the inner ring plate in the transition fixing layer, so that the inner ring plate remains relatively fixed during operation, while the outer ring plate, which is fixedly connected to the inner wall of the corrugated pipe substrate, deforms synchronously with the corresponding corrugated pipe segment. This allows the composite inner wall protection structure to adapt to corrugated deformation and play a buffering and protective role in different corrugated pipe segments. Through the synergistic cooperation of the above-mentioned segmented structure and composite layer protection structure, this invention effectively reduces the degree of constraint between the inner wall protection structure and the corrugated pipe substrate, improves the deformation coordination and operational stability of the overall structure under complex loads and large compensation conditions, and further extends the service life of the corrugated compensator. Attached Figure Description

[0026] Figure 1 This is a schematic cross-sectional view of the corrugated compensator of the present invention;

[0027] Figure 2 for Figure 1 The front view;

[0028] Figure 3 for Figure 1 Top view.

[0029] Explanation of reference numerals in the attached drawings: 1-Anti-erosion functional layer; 11-Outer ceramic plate; 12-Inner ceramic plate; 2-Transition fixing layer; 21-Outer ring plate; 22-Inner ring plate; 3-Corrugated pipe substrate; 31-First corrugated pipe section; 32-Second corrugated pipe section; 4-Upper connecting plate; 41-Upper connecting ring; 42-Upper square block; 5-Middle ring plate; 51-Middle connecting ring; 52-Middle square block; 6-Lower connecting plate; 61-Lower connecting ring; 62-Lower square block; 7-Connecting hole; 8-Through hole; 9-Threaded rod. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention belong to the present invention.

[0031] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0032] like Figure 1-3 As shown in the figure, this embodiment discloses a composite corrugated compensator inner wall protection structure. The inner wall protection structure is a composite layer structure, including an anti-erosion functional layer 1, a transition fixing layer 2, and a bellows substrate 3. The anti-erosion functional layer 1, the transition fixing layer 2, and the bellows substrate 3 are arranged in a radial direction from the inside to the outside. The layered structure realizes the synergy of anti-erosion function and displacement compensation function.

[0033] The erosion-resistant functional layer, which is in direct contact with the media flow, includes an outer ceramic plate 11 and an inner ceramic plate 12. The outer ceramic plate 11 and inner ceramic plate 12 are made of a ceramic matrix material with high wear resistance and serve as the first protective structure along the media flow's erosion path, bearing the erosion and wear caused by solid particles and high-speed flow on the inner wall. The ceramic matrix material has higher hardness and wear resistance than the transition fixing layer 2 and is divided into multiple independent small units. This allows each small unit to generate minute relative displacements or rotations when the bellows substrate 3 undergoes axial, radial, or angular deformation, thereby releasing local stress and preventing the overall brittle structure from cracking or peeling during repeated deformation.

[0034] The transition fixing layer, serving as the fixing base for the anti-erosion functional layer, is located on the outside of the anti-erosion functional layer. The transition fixing layer includes an outer ring plate 21 and an inner ring plate 22, which are made of metal materials with good weldability and certain toughness, and are used to provide an installation and support foundation for the anti-erosion functional layer 1. The outer ring plate and the inner ring plate have a gap in the radial direction and are staggered in the axial direction, forming a non-rigid connection structure. Through the radial gap and axial stagger, a structural relationship that can buffer deformation is formed between the outer ring plate 21 and the inner ring plate 22, thereby reducing stress concentration when the bellows base 3 undergoes displacement compensation deformation. The inner walls of the outer ring plate 21 and the inner ring plate 22 are respectively provided with an outer ceramic plate 11 and an inner ceramic plate 12, so that the anti-erosion functional layer 1 is reliably fixed through the transition fixing layer 2 and indirectly connected to the bellows base 3.

[0035] The bellows base 3 is made of thin metal sheet and has a corrugated structure. It is used to realize the displacement compensation function of the bellows compensator. The bellows base 3 can undergo elastic or plastic deformation under axial, radial or angular deformation conditions to absorb pipeline displacement. One end of the outer ring plate 21 is fixedly connected to the inner wall of the bellows base 3, so that the outer ring plate 21 deforms synchronously with the bellows base 3, while the inner ring plate 22 remains relatively independent under axial misalignment conditions. Thus, the composite inner wall protection structure has good deformation adaptability while ensuring erosion resistance.

[0036] Furthermore, the small units of the outer ceramic plate 11 and the inner ceramic plate 12 are fixed to the inner walls of the outer ring plate 21 and the inner ring plate 22 by spot welding, plug welding, or brazing. The outer ceramic plate 11 and the inner ceramic plate 12 are reliably fixed to the transition fixing layer 2 by welding, so that the anti-erosion functional layer 1 maintains a stable position under the conditions of media erosion and corrugation deformation, while avoiding the problem of easy aging and failure under high temperature and high flow rate conditions when using adhesives. The outer ring plate 21 and the inner ring plate 22 are made of ordinary carbon steel or metal thin plates with excellent weldability and certain toughness, which not only facilitates welding connection with the bellows substrate 3, but also buffers and disperses the local impact load from the anti-erosion functional layer 1 during the deformation of the bellows substrate 3, thereby reducing the risk of interface stress concentration.

[0037] In the specific implementation process, the inner ring plate 22 in the transition fixing layer 2 is preferably first processed into a cylindrical structure. The installation positions of each small unit of the outer ceramic plate 11 or inner ceramic plate 12 are marked on the outer surface of the inner ring plate 22 according to a preset array pattern, and a through hole for welding and fixing is formed at each installation position. The through hole is preferably a plug weld hole structure. The outer ceramic plate 11 or inner ceramic plate 12, which has been pre-metallized on the back, is covered on the corresponding through hole position, and the connection is made by brazing with high-strength heat-resistant brazing filler. During the brazing process, the brazing filler flows through the through hole and forms an extended weld head on the back of the inner ring plate 22, thereby forming a reliable bond between the ceramic plate and the inner ring plate 22, so that the anti-erosion functional layer 1 and the transition fixing layer 2 constitute a stable integrated composite unit. After welding, the outer side of the through hole can be further sealed with a ceramic cover plate that matches the hole diameter and a high-temperature resistant filling material to ensure the continuity and flatness of the inner wall surface and avoid additional disturbance or local erosion at the welding position during the flow of the medium.

[0038] Another embodiment of the present invention discloses a bellows compensator, including the aforementioned composite bellows compensator inner wall protection structure. This composite bellows compensator inner wall protection structure comprises an anti-erosion functional layer 1, a transition fixing layer 2, and a bellows base 3, used to form continuous inner wall protection for the bellows base 3 during medium flow. The bellows compensator also includes an upper connecting plate 4, an intermediate ring plate 5, and a lower connecting plate 6. The upper connecting plate 4, the intermediate ring plate 5, and the lower connecting plate 6 are arranged sequentially along the axial direction and serve as structural segments and installation connection components for the bellows base 3, enabling the bellows compensator to... The system achieves reliable connection and segmented stress distribution; the corrugated pipe base includes a first corrugated pipe section 31 and a second corrugated pipe section 32 arranged sequentially along the axial direction, which together share axial displacement, radial offset or angular deformation; the first corrugated pipe section 31 is located between the upper connecting plate 4 and the middle ring plate 5, and the second corrugated pipe section 32 is located between the middle ring plate 5 and the lower connecting plate 6. Thus, through the combination of the segmented corrugated pipe structure and the composite inner wall protection structure, the deformation concentration of a single corrugated pipe section is reduced, and the structural stability and service life of the corrugated compensator under large compensation and complex load conditions are improved.

[0039] In this embodiment, the first corrugated pipe section 31 and the second corrugated pipe section 32 are respectively connected to the upper connecting plate 4, the intermediate ring plate 5, and the lower connecting plate 6 by welding. The first corrugated pipe section 31 is fixedly connected to the upper connecting plate 4 and the intermediate ring plate 5 by welding, and the second corrugated pipe section 32 is fixedly connected to the intermediate ring plate 5 and the lower connecting plate 6 by welding. This creates a continuous but segmented compensation structure in the axial direction of the corrugated pipe base 3, ensuring good overall sealing and structural strength of the corrugated compensator when subjected to internal pressure and displacement loads. The inner ring plate 22 corresponding to the first corrugated pipe section 31 is fixedly installed via the intermediate ring plate 5, and the inner ring plate 22 corresponding to the second corrugated pipe section 32 is fixedly installed via the lower connecting plate 6, so that the inner ring plate 22 is axially misaligned relative to the outer ring plate 21.

[0040] Furthermore, the upper connecting plate 4 and the lower connecting plate 6 are respectively provided with connecting holes 7, and bolts are installed through the connecting holes 7 to connect to the pipeline. The connecting holes 7 are used to pass through the pipeline connecting bolts, so that the upper connecting plate 4 and the lower connecting plate 6 can achieve a reliable flange connection with the external pipeline system. An upper connecting plate 4 extends an upper connecting ring 41 towards the lower connecting plate 6. Several upper square blocks 42 are arranged on the outer side of the upper connecting ring 41. A middle connecting ring 51 extends from both sides of the middle ring plate 5. Several middle square blocks 52 are arranged on the outer side of the middle connecting ring 51. A lower connecting ring 61 extends from the lower connecting plate 6 towards the upper connecting plate 4. Several lower square blocks 62 are arranged on the outer side of the lower connecting ring 61. Through holes 8 are provided in the upper square blocks 42, middle square blocks 52 and lower square blocks 62. A threaded rod 9 passes through the through hole 8 and cooperates with the nut to achieve axial locking. The upper connecting ring 41, middle connecting ring 51 and lower connecting ring 61 are arranged axially aligned. The threaded rod 9 passes through the through hole 8 and cooperates with the nut. In assembly or non-compensation conditions, the upper connecting plate 4, middle ring plate 5 and lower connecting plate 6 are relatively limited to restrict the abnormal relative displacement of the compensator in the non-working direction, thereby improving the overall stability and reliability of the structure during transportation, installation and operation.

[0041] This invention also discloses a design method for designing the inner wall protection structure of the above-mentioned composite corrugated compensator, comprising the following steps:

[0042] S1, Operating Parameter Analysis: Obtain the operating parameters of the corrugated compensator, including the medium composition, medium flow rate, operating temperature, particle size and erosion intensity in the medium, and determine the erosion level that the anti-erosion functional layer 1 needs to withstand based on the operating parameters.

[0043] S2, Anti-erosion functional layer design: Select the material type of anti-erosion functional layer 1 according to the erosion level, and design the anti-erosion functional layer 1 as a block structure composed of outer ceramic plate 11 and inner ceramic plate 12 to adapt to the deformation characteristics of the corrugated pipe substrate 3.

[0044] S3, Transition fixing layer structure matching: Based on the material properties of the bellows base 3 and the axial displacement compensation amount, the material of the transition fixing layer 2 is determined, and the transition fixing layer 2 is designed as an outer ring plate 21 and an inner ring plate 22, so that the outer ring plate 21 and the inner ring plate 22 form a gap in the radial direction and a misaligned arrangement in the axial direction.

[0045] S4, Non-rigid connection relationship determined: The outer ring plate 21 is fixedly connected to the inner wall of the bellows base 3, so that the outer ring plate 21 deforms synchronously with the bellows base 3; the inner ring plate 22 is installed and fixed through a connecting structure, so that the inner ring plate 22 maintains an axially misaligned state relative to the outer ring plate 21, thereby forming a non-rigid connection structure.

[0046] S5, Overall Structure Verification and Validation: Based on the combined structure of anti-erosion functional layer 1, transition fixing layer 2 and bellows substrate 3, the deformation coordination, welding reliability and erosion durability of the inner wall protection structure are verified, and the design of the inner wall protection structure of the composite bellows compensator is completed.

[0047] Through the above design method, the inner wall protection structure of the composite corrugated compensator, through the coordinated cooperation of the anti-erosion functional layer 1, the transition fixing layer 2 and the bellows base 3, when the bellows base 3 undergoes axial, radial or angular displacement, the anti-erosion functional layer 1 provides reliable inner wall protection while achieving coordinated adaptation with the corrugation deformation through the segmented structure and the non-rigid connection of the transition fixing layer 2; the outer ring plate 21 is fixedly connected to the inner wall of the bellows base 3 and deforms synchronously with the bellows base 3, while the inner ring plate 22 remains relatively stable through the connecting structure, thereby forming a structural state in which axial misalignment and radial gap coexist between the two, effectively reducing the concentrated transmission of erosion load and deformation stress to the bellows base 3. By combining the segmented structural arrangement of the first corrugated pipe section 31, the second corrugated pipe section 32, the upper connecting plate 4, the middle ring plate 5, and the lower connecting plate 6, the inner wall protection structure can adapt to the displacement compensation process in different corrugated pipe sections, ensuring that the corrugated compensator has good deformation coordination, structural stability, and long-term operational reliability under complex working conditions.

[0048] In one specific embodiment, this embodiment is applied to the protection of the inner wall of a corrugated compensator in a blast furnace gas purification system of an ironmaking plant. The blast furnace gas pipeline transports crude gas during operation at a temperature of 200–350°C under medium pressure. The medium contains a large amount of hard, irregularly shaped, and sharply angular dust particles, primarily composed of solid particles such as Fe2O3 and SiO2. Under these conditions, the gas flow velocity within the pipeline is high, reaching 18–25 m / s during operation. The dust particles move at high speed with the gas and continuously scour the inner wall of the corrugated compensator.

[0049] In actual operation, when using a single-material metal bellows (such as 316L stainless steel bellows) as the compensation element, the inner wall of the bellows, especially in the trough areas, is easily subjected to continuous cutting and impact under the combined effects of high temperature, high flow rate, and high dust content in the gas. This leads to significant wall thinning in local areas within a short operating cycle, and even perforation, thereby posing a risk of gas leakage and affecting the safe operation and continuous production of the blast furnace gas system. Based on the above operating conditions and usage requirements, this embodiment adopts a composite bellows compensator inner wall protection structure to protect the inner wall of the bellows compensator, in order to meet the long-term operating requirements under the conditions of high temperature, high flow rate, and high dust content gas transportation.

[0050] In this embodiment, the anti-erosion functional layer 1 is disposed on the inner side of the bellows substrate 3 as a direct medium layer in contact with the medium flow. The anti-erosion functional layer 1 includes an outer ceramic plate 11 and an inner ceramic plate 12. Both the outer ceramic plate 11 and the inner ceramic plate 12 are made of alumina-toughened zirconia ceramic matrix composite material. This ceramic matrix composite material, while maintaining the high hardness (HV>1200) and high fracture toughness of zirconia material, further improves the thermal shock resistance and impact resistance of the material through the alumina phase transformation toughening mechanism, so as to adapt to the erosion environment under high temperature and dusty gas-solid two-phase flow conditions. The outer ceramic plate 11 and the inner ceramic plate 12 are both processed into rectangular plates of uniform size, for example, their size is 50mm×100mm×10mm. The surface of the outer ceramic plate 11 and the inner ceramic plate 12 that contacts the metal structure is pre-treated with metallization before assembly to form a stable metal transition layer between the ceramic matrix and the metal, which meets the connection requirements of the subsequent welding and fixing process.

[0051] In this embodiment, the transition fixing layer 2 serves as a stress buffer and connection layer between the anti-erosion functional layer 1 and the bellows substrate 3. The transition fixing layer 2 includes an outer ring plate 21 and an inner ring plate 22 arranged in a nested manner. Both the outer ring plate 21 and the inner ring plate 22 are made of Q235B carbon structural steel plate. Q235B material has good plastic deformation capacity and welding process performance, and can play a role in stress buffering and redistribution between the anti-erosion functional layer 1 and the bellows substrate 3. The outer ring plate 21 and the inner ring plate 22 are respectively processed from Q235B steel plates with a thickness of 4mm. Specifically, the whole steel plate is rolled into a cylindrical structure that matches the inner diameter of the target bellows substrate 3. After the rolling is completed, a single-sided V-shaped bevel is set along the generatrix of the cylinder, and a closed cylindrical structure is formed by butt welding, thereby constituting the inner ring plate 22 and the outer ring plate 21, respectively. This processing method is beneficial to ensure the overall structural continuity and welding strength of the ring plates. The inner ring plate 22 is made of Q235 carbon structural steel plate rolled and welded into a cylindrical structure that matches the inner diameter of the corrugated pipe base 3. The fixed positions of the outer ceramic plate 11 and the inner ceramic plate 12 are marked on the outer surface of the cylinder according to a preset array, and a plug weld hole with a diameter of Φ25mm is machined at the center of each fixed position. The metallized outer ceramic plate 11 and the inner ceramic plate 12 are covered and set at the corresponding plug weld hole positions, and are fixed by brazing with high-strength heat-resistant brazing filler metal. After the brazing filler metal flows through the plug weld hole, it forms a mushroom-shaped weld joint on the back of the inner ring plate 22, thereby reliably fixing the outer ceramic plate 11 and the inner ceramic plate 12 to the inner ring plate 22, forming an integrated anti-erosion functional unit. The outside of the plug weld hole is then filled with a ceramic cover plate that matches the hole diameter and high-temperature resistant adhesive to ensure the continuity and flatness of the inner wall surface.

[0052] After completing the aforementioned functional units, the outer ring plate 21, formed by rolling and welding a single sheet, is fitted onto the outside of the inner ring plate 22, forming a double-layer transition and fixing layer 2 structure. During assembly, the longitudinal welds of the outer ring plate 21 and the inner ring plate 22 are staggered in the circumferential direction, while the process holes and positioning holes on the two layers are spatially avoided. The outer ring plate 21 and the inner ring plate 22 are welded and fixed at different ends in the axial direction, creating a gap in the radial direction and a staggered arrangement in the axial direction, thus forming a non-rigid connection structure that allows for relative expansion and contraction and displacement between the layers during operation.

[0053] In the structural design of this embodiment, the erosion-resistant functional layer 1 directly resists the erosion and wear of the dust-laden medium through the ceramic matrix material. The transition fixing layer 2 disperses and buffers the impact load and deformation stress through the staggered arrangement of the double-layer outer ring plate 21 and inner ring plate 22. The bellows substrate 3 mainly undertakes the functions of system pressure and displacement compensation. The small-block arrangement of the outer ceramic plate 11 and inner ceramic plate 12 enables the erosion-resistant functional layer 1 to generate a small relative displacement when the bellows substrate 3 deforms. The non-rigid connection structure of the double-layer transition fixing layer 2 further releases the interlayer constraints, and the stress gradually decreases in the multi-layer structure, thereby improving the overall structure's adaptability to erosion and deformation conditions.

[0054] Through the aforementioned structural design and material matching, the composite corrugated compensator inner wall protection structure provided in this embodiment is expected to significantly improve the erosion resistance of the inner wall of the corrugated compensator under high-temperature and high-dust conditions such as blast furnace gas in ironmaking plants. This ensures that the erosion-resistant functional layer 1 maintains a stable working state under long-term media scouring, thereby significantly extending the actual service life of the bellows base 3 compared to a 316L bellows without an inner wall protection structure. Simultaneously, the double-layered staggered non-rigid structure formed by the outer ring plate 21 and the inner ring plate 22 in the transition fixing layer 2 disperses and buffers impact loads and deformation stresses during operation, reducing the cyclic stress level borne by the bellows base 3. This is beneficial for improving its fatigue stress state and enhancing operational safety. Furthermore, by extending the maintenance and replacement cycle of the corrugated compensator and reducing unplanned downtime, this embodiment demonstrates good comprehensive economic efficiency and engineering application value throughout its service life.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite corrugated compensator inner wall protection structure, characterized in that, The inner wall protection structure is a composite layer structure, including an anti-erosion functional layer (1), a transition fixing layer (2), and a bellows substrate (3). The erosion-resistant functional layer (1) is used to directly contact the medium flow and includes an outer ceramic plate (11) and an inner ceramic plate (12). The transition fixing layer (2) serves as the fixing substrate for the anti-erosion functional layer (1) and is disposed on the outside of the anti-erosion functional layer (1). The transition fixing layer includes an outer ring plate (21) and an inner ring plate (22) sleeved together. The outer ring plate (21) and the inner ring plate (22) have a gap in the radial direction and are staggered in the axial direction to form a non-rigid connection structure. The inner walls of the outer ring plate (21) and the inner ring plate (22) are respectively provided with the outer ceramic plate (11) and the inner ceramic plate (12). The corrugated pipe base (3) is made of thin metal sheet and has a corrugated structure, which is used to realize the displacement compensation function of the corrugated compensator. One end of the outer ring plate (21) is fixedly connected to the inner wall of the corrugated pipe base (3).

2. The composite corrugated compensator inner wall protection structure according to claim 1, characterized in that, The outer ceramic plate (11) and inner ceramic plate (12) are made of ceramic-based materials, which have higher hardness and wear resistance than the transition fixing layer (2), and are divided into multiple independent small block units.

3. The composite corrugated compensator inner wall protection structure according to claim 2, characterized in that, The small units of the outer ceramic plate (11) and the inner ceramic plate (12) are fixed to the inner walls of the outer ring plate (21) and the inner ring plate (22) by spot welding, plug welding or brazing.

4. The composite corrugated compensator inner wall protection structure according to claim 1, characterized in that, The outer ring plate (21) and inner ring plate (22) are made of ordinary carbon steel or metal sheet with excellent weldability and certain toughness.

5. A corrugated compensator, characterized in that, The composite corrugated compensator inner wall protection structure as described in any one of claims 1-4 is included. The corrugated compensator further includes an upper connecting plate (4), an intermediate ring plate (5) and a lower connecting plate (6). The corrugated pipe base (3) includes a first corrugated pipe section (31) and a second corrugated pipe section (32) arranged sequentially along the axial direction. The first corrugated pipe section (31) is located between the upper connecting plate (4) and the intermediate ring plate (5), and the second corrugated pipe section (32) is located between the intermediate ring plate (5) and the lower connecting plate (6).

6. The corrugated compensator according to claim 5, characterized in that, The first corrugated pipe section (31) and the second corrugated pipe section (32) are respectively connected to the upper connecting plate (4), the middle ring plate (5) and the lower connecting plate (6) by welding.

7. The corrugated compensator according to claim 5 or 6, characterized in that, The inner ring plate (22) corresponding to the first corrugated pipe section (31) is installed and fixed by the intermediate ring plate (5), and the inner ring plate (22) corresponding to the second corrugated pipe section (32) is installed and fixed by the lower connecting plate (6) so that the inner ring plate (22) is axially misaligned relative to the outer ring plate (21).

8. The corrugated compensator according to claim 7, characterized in that, The upper connecting plate (4) and the lower connecting plate (6) are respectively provided with connecting holes (7), and bolts are installed through the connecting holes (7) to connect with the pipeline.

9. The corrugated compensator according to claim 8, characterized in that, The upper connecting plate (4) extends an upper connecting ring (41) towards the lower connecting plate (6). Several upper square blocks (42) are arranged on the outer side of the upper connecting ring (41). A middle connecting ring (51) extends on both sides of the middle ring plate (5). Several middle square blocks (52) are arranged on the outer side of the middle connecting ring (51). The lower connecting plate (6) extends a lower connecting ring (61) towards the upper connecting plate (4). Several lower square blocks (62) are arranged on the outer side of the lower connecting ring (61). Through holes (8) are provided in the upper square blocks (42), middle square blocks (52) and lower square blocks (62). The threaded rod (9) passes through the through holes (8) and cooperates with the nut to achieve axial locking.

10. A design method for designing the inner wall protection structure of the composite corrugated compensator according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1, Working condition parameter analysis: Obtain the working condition parameters of the corrugated compensator, including the medium composition, medium flow rate, working temperature, particle size and erosion intensity of the medium particles, and determine the erosion level that the anti-erosion functional layer (1) needs to withstand based on the working condition parameters. S2, Anti-erosion functional layer design: Select the material type of the anti-erosion functional layer (1) according to the erosion level, and design the anti-erosion functional layer (1) as a block structure composed of an outer ceramic plate (11) and an inner ceramic plate (12) to adapt to the deformation characteristics of the corrugated pipe substrate (3); S3, Transition fixing layer structure matching: Based on the material properties and axial displacement compensation of the corrugated pipe substrate (3), determine the material of the transition fixing layer (2), and design the transition fixing layer (2) as an outer ring plate (21) and an inner ring plate (22) to form a gap in the radial direction and a misaligned arrangement in the axial direction; S4, Non-rigid connection relationship determined: The outer ring plate (21) is fixedly connected to the inner wall of the bellows base (3), so that the outer ring plate (21) deforms synchronously with the bellows base (3); the inner ring plate (22) is installed and fixed through a connecting structure, so that the inner ring plate (22) maintains an axial misalignment relative to the outer ring plate (21), thereby forming a non-rigid connection structure; S5, Overall structure verification and validation: Based on the combined structure of the anti-erosion functional layer (1), transition fixing layer (2) and corrugated pipe substrate (3), the deformation coordination, welding reliability and erosion durability of the inner wall protection structure are verified, and the design of the inner wall protection structure of the composite corrugated compensator is completed.

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