A sealing structure of a high-pressure-resistant and corrosion-resistant acetylene purification membrane module and a preparation method thereof

Abstract

This invention relates to a sealing structure and its preparation method for a high-pressure, corrosion-resistant acetylene purification membrane module, belonging to the field of gas separation technology. The sealing structure includes: a membrane element support cylinder; an end clamping assembly comprising a limiting step and a pressure equalizing gasket; a double-layer sealing ring consisting of a main sealing ring and an isolation sealing ring, forming an annular isolation cavity between them; and a leakage guide channel connecting the isolation cavity to an external safety collection port. When a micro-leakage occurs in the main seal, the medium enters the isolation cavity and is discharged to the safety collection end through the guide channel, preventing external leakage. The main sealing ring is made of a pressure-resistant, low-permeability material, and the isolation sealing ring is made of a chemically corrosion-resistant material. The preparation method includes precision machining of the sealing groove, sealing ring forming and secondary vulcanization, staged clamping assembly, and leakage testing. This invention transforms micro-leakage into a controllable state, employs a modular design to adapt to different membrane area configurations, and provides a safe and reliable sealing solution for acetylene membrane separation and purification.

Description

Technical Field

[0001] This invention belongs to the field of gas separation technology, specifically relating to a sealing structure and preparation method of a high-pressure and corrosion-resistant acetylene purification membrane module. Background Technology

[0002] Electronic-grade acetylene (purity ≥99.999%) is a key electronic specialty gas in semiconductor manufacturing and is indispensable in processes such as chemical vapor deposition. Membrane separation technology, due to its advantages of low energy consumption, compact equipment, and continuous operation, is considered an ideal alternative to traditional cryogenic distillation and absorption methods for acetylene purification. In practical applications, to increase the permeate flux of the membrane module and obtain sufficient product gas yield, the membrane separation process typically needs to operate at relatively high pressures (e.g., 2-5 MPa).

[0003] However, when applying membrane separation technology to acetylene purification, the sealing of the membrane module becomes a key bottleneck restricting its long-term stable operation. First, high-pressure operating conditions exacerbate the risk of seal failure at various connection points of the membrane module. Traditional sealing structures are prone to stress relaxation during repeated pressurization and depressurization, leading to a decline in sealing performance. Second, industrial acetylene feed gas often contains corrosive impurities such as hydrogen sulfide (H2S). Conventional sealing materials, such as nitrile rubber and ordinary silicone rubber, are prone to swelling, hardening, or chemical degradation after prolonged contact with these corrosive gases, resulting in seal failure. More seriously, acetylene itself is a flammable and explosive gas; leaks due to seal failure will cause serious safety accidents.

[0004] In the prior art, some research has been conducted on the sealing problem of gas separation membrane modules. For example, Chinese patent CN115105930A discloses a multifunctional hollow fiber membrane gas separation and purification system, which mentions the connection structure of the membrane module, but does not provide a detailed design of the sealing structure, nor does it provide specific optimization for high-pressure and corrosive gas environments. Similarly, Chinese patent CN214780771U discloses a membrane separation helium purification device, which uses a two-stage membrane separation module, but also does not disclose a dedicated sealing structure suitable for high-pressure acetylene systems.

[0005] Currently, there is a lack of systematic solutions in existing technologies for the sealing problems of acetylene purification membrane modules under the triple challenges of high pressure, corrosion, and long-term operation. On the one hand, it is necessary to ensure the reliability and pressure resistance of the sealing structure under high pressure; on the other hand, the sealing material needs to withstand the chemical corrosion of acetylene and impurities such as H2S; in addition, it is also necessary to consider the scalable manufacturing requirements for different membrane area configurations. The lack of a sealing structure design and material combination specifically for high-pressure acetylene purification has become a key technical problem restricting the stability of membrane separation processes and their industrialization.

[0006] Therefore, how to design a sealing structure for an acetylene purification membrane module that can simultaneously meet the requirements of high-pressure sealing, corrosion resistance, and scalable manufacturing is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] In view of this, the present invention aims to solve the problem that existing membrane modules, when applied to high-pressure acetylene purification, lack a dedicated sealing structure design to address the triple challenges of high pressure, corrosion, and long-term operation. Conventional sealing materials are prone to swelling, aging, or leakage, leading to module leakage, decreased selectivity, and even safety hazards.

[0008] To solve the above technical problems, On one hand, the present invention provides a sealing structure for a high-pressure and corrosion-resistant acetylene purification membrane module, comprising: The membrane element support cylinder has a sealing groove at its end; An end clamping assembly is disposed at the end of the membrane element support cylinder and is used to provide clamping force; A double-layer sealing ring is disposed in the sealing groove. The double-layer sealing ring includes a main sealing ring and an isolation sealing ring arranged sequentially along the axial direction. An annular isolation cavity is formed between the main sealing ring and the isolation sealing ring. And a leakage guide channel connecting the annular isolation cavity to an external safety collection port.

[0009] The end clamping assembly includes a limiting step and a pressure equalizing pad. The limiting step is used to limit the clamping stroke, and the pressure equalizing pad is disposed between the end clamping assembly and the double-layer sealing ring to ensure that the end face is subjected to uniform force.

[0010] Preferably, the main sealing ring is made of a pressure-resistant, low-permeability elastic material, and the isolation sealing ring is made of a chemically resistant material. The main sealing ring can be made of fluororubber or EPDM rubber, and the isolation sealing ring can be made of perfluoroether rubber or fluororubber. A pre-tightening spring can be provided inside the main sealing ring to provide initial sealing force, or an X-shaped sealing ring with double sealing lips can be used to further improve sealing reliability.

[0011] Preferably, the leakage guide channel can be disposed on the end clamping assembly or on the membrane element support cylinder, allowing for flexible layout. A pre-tightening spring is provided inside the main sealing ring to provide initial sealing force.

[0012] Preferably, the main sealing ring is an irregularly shaped sealing ring with an X-shaped cross-section and double sealing lips. The end clamping assembly can adopt a flange clamping structure or a threaded clamping structure.

[0013] Preferably, the sealing groove has a width of 8-9 mm, a depth of 4.5-5.0 mm, and a surface roughness Ra ≤ 0.8 μm at the bottom. The dimensions of the sealing groove are standardized and suitable for membrane modules with membrane areas of 5 cm², 45 cm², 0.15 m², or 0.5 m², enabling modular manufacturing of modules with different specifications.

[0014] On the other hand, the present invention also provides a method for preparing the above-mentioned sealing structure, including the following steps: S1, end sealing groove processing: the sealing groove at the end of the membrane element support cylinder is precisely processed to control the dimensional tolerance and surface roughness; S2. Sealing ring molding and vulcanization: The main sealing ring and the isolation sealing ring are molded separately and subjected to secondary vulcanization treatment; S3. Assembly: Install the main sealing ring and the isolation sealing ring into the sealing groove in sequence, place the pressure equalizing gasket, install the end clamping assembly, and tighten in stages according to the preset torque. S4. Leakage Test: After assembly, a pressure resistance and leakage test will be conducted. The test pressure is 1.1 times the design pressure, and the leakage rate should be ≤1×10⁻⁶. -6 Pa·m³ / s.

[0015] Furthermore, in the processing step of the end sealing groove, a CNC lathe is used for processing, and the processing accuracy is controlled within the range of ±0.05mm. After processing, ultrasonic cleaning is performed and drying is carried out at 80℃ for 30 minutes.

[0016] Furthermore, in the sealing ring forming and vulcanization steps, the forming temperature is 170℃, the pressure is 15MPa, and the vulcanization time is 10 minutes; the secondary vulcanization treatment is carried out at 200℃ for 4 hours; in the assembly steps, the graded compression includes: first pre-tightening with a torque of 5N·m, then secondary compression with a torque of 10N·m, and finally final compression with a torque of 15N·m, so that the compression rate of the sealing ring is controlled within the range of 15%-20%.

[0017] Furthermore, in the leakage test step, the test medium is nitrogen gas, the pressure holding time is 30 minutes, and the leakage rate is detected by a helium mass spectrometer.

[0018] In addition, the present invention also provides a high-pressure and corrosion-resistant acetylene purification membrane module including the above-mentioned sealing structure, wherein the effective membrane area of ​​the membrane module is greater than 0.15m², the pressure resistance is greater than 5.1MPa, and the corrosion resistance time of H2S impurities in acetylene is greater than 40 days.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention adopts a double-layer sealing ring structure with a main seal and an isolation seal, and sets up a leakage guide channel to transform unavoidable micro-leakage into a controllable, detectable, and safe-to-handle state. When a micro-leak occurs in the main seal, the leaking medium enters the isolation cavity and is discharged to the safe collection end through the guide channel, avoiding direct entry into the shell side or external leakage, and significantly reducing the risk of external leakage and cross-leakage in the acetylene high-pressure system.

[0020] (2) The end clamping assembly of the present invention, consisting of a limiting step and a pressure equalizing pad, ensures uniform force on the end face, reduces the risk of seal extrusion caused by local stress, improves pressure resistance, and extends seal life. The pressure equalizing clamping structure, combined with the graded clamping assembly process, ensures that the compression rate of the sealing ring is controlled within the range of 15%-20%, achieving reliable sealing.

[0021] (3) In view of the corrosive impurities such as H2S that may be contained in the acetylene feedstock, the present invention has made differentiated material selections for the main sealing ring and the isolation sealing ring. The isolation sealing ring is made of chemically resistant materials (such as perfluoroether rubber and fluororubber), and the main sealing ring is made of pressure-resistant and low-permeability materials (such as fluororubber and EPDM rubber). The resistance to compression set is improved by secondary vulcanization treatment, so that the membrane module can maintain good stability during long-term operation in H2S atmosphere.

[0022] (4) The present invention adopts a modular end cap and standardized sealing groove size design, and unifies the sealing interface specifications for different membrane area configurations (5cm², 45cm², 0.15m², 0.5m²), realizing scalable manufacturing from small-scale pilot, pilot-scale to industrial side line, reducing maintenance costs and spare parts management difficulty, and providing a reliable key component solution for the pilot-scale amplification and industrialization of acetylene membrane separation and purification.

[0023] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a cross-sectional schematic diagram of the sealing structure of the high-pressure and corrosion-resistant acetylene purification membrane module with flange clamping method in Embodiment 1 of the present invention; Figure 2This is a cross-sectional schematic diagram of the sealing structure of the high-pressure and corrosion-resistant acetylene purification membrane assembly with threaded clamping method in Embodiments 2 and 4 of the present invention. The structure integrates a leakage monitoring system. The figure shows the structural relationship between the leakage guide channel, the gas collection main pipe, the acetylene concentration sensor, the pressure sensor, and the alarm unit. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0026] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0027] This invention provides a sealing structure and preparation method for a high-pressure and corrosion-resistant acetylene purification membrane module. Figure 1 A schematic diagram of a sealing structure according to a specific embodiment of the present invention is shown. Figure 1 As shown, the sealing structure includes: a membrane element support cylinder, an end clamping assembly, a double-layer sealing ring, and a leakage guide channel.

[0028] Example 1 This embodiment provides a basic sealing structure and assembly method for an acetylene purification membrane module.

[0029] The sealing structure of this embodiment includes the following components: (1) Membrane element support cylinder: Made of stainless steel, with a sealing groove at the end of the cylinder. The sealing groove is 8mm wide and 4.5mm deep, and the surface roughness of the bottom of the groove is controlled to Ra≤0.8μm to ensure the fit with the sealing ring. As a variation, the sealing groove can also be 9mm wide and 5.0mm deep to accommodate a sealing ring with a cross-sectional diameter of 6.0mm.

[0030] (2) End clamping assembly: including clamping flange, limiting step, and pressure equalizing gasket. The clamping flange is made of high-strength alloy steel (such as 42CrMo). The limiting step is set on the contact surface between the flange and the cylinder, with a limiting height of 3mm, to ensure that the sealing ring is not over-compressed during clamping. The pressure equalizing gasket is made of copper material with a thickness of 1.5mm and is set between the flange and the sealing ring to make the end face uniformly stressed and reduce seal extrusion caused by local stress.

[0031] As an alternative, the end clamping assembly can also adopt a threaded clamping structure, including a threaded cap, a limiting step, and a pressure equalizing gasket. The pressure equalizing gasket can be made of polytetrafluoroethylene (PTFE) material with a thickness of 1 mm. Precise clamping is achieved by controlling the thread insertion depth during assembly.

[0032] (3) Double-layer sealing ring: A combination structure of main seal and isolation seal is adopted. The main seal is located near the process medium and is made of pressure-resistant, low-permeability elastic material, specifically fluororubber (FKM), with a Shore hardness of 75A and a cross-sectional diameter of 5.3mm. A pre-tightening spring is provided inside the main seal, such as a stainless steel spring built into the O-ring, to provide initial sealing force. The isolation seal is located outside the main seal and is made of chemically resistant material, specifically perfluoroether rubber (FFKM), with a Shore hardness of 80A and a cross-sectional diameter of 5.3mm. An annular isolation cavity is formed between the main seal and the isolation seal, with a cavity width of 2mm.

[0033] As an alternative material combination, the main sealing ring can be made of ethylene propylene diene monomer (EPDM) rubber with a Shore hardness of 70A and a cross-sectional diameter of 6.0mm; the isolation sealing ring can be made of fluororubber (FKM) with a Shore hardness of 75A, a cross-sectional diameter of 6.0mm, and an annular isolation cavity width of 3mm. This combination can reduce material costs while ensuring corrosion resistance.

[0034] (4) Leakage Guide Channel: A leakage guide hole with a diameter of 1.5 mm is opened on the end clamping assembly to connect the isolation chamber with the external safety collection port. As an alternative, the leakage guide channel can also be set on the membrane element support cylinder, for example, by machining an axial guide groove with a width of 2 mm and a depth of 1.5 mm on the outer circle of the cylinder end. When a micro-leak occurs in the main seal, the leaking medium enters the isolation chamber and is discharged to the safety collection end through the guide channel, avoiding direct entry into the shell side or external leakage.

[0035] The sealing structure preparation method in this embodiment includes the following steps: (1) End sealing groove machining: The sealing groove at the end of the membrane element support cylinder is machined using a CNC lathe. The machining accuracy is controlled within ±0.05mm, and the surface roughness Ra of the groove bottom is ≤0.8μm. After machining, the oil and chips are removed by ultrasonic cleaning, and then dried at 80℃ for 30 minutes.

[0036] (2) Sealing Ring Molding and Secondary Vulcanization: The main sealing ring and the isolation sealing ring are prepared by compression molding. The molding temperature is 170℃, the pressure is 15MPa, and the vulcanization time is 10 minutes. After molding, a secondary vulcanization treatment is performed, which is carried out at 200℃ for 4 hours to remove low molecular weight substances and improve the compression set resistance of the sealing ring. For EPDM rubber sealing rings, the secondary vulcanization temperature can be 150℃; for hydrogenated nitrile rubber sealing rings, the secondary vulcanization temperature can be 160℃.

[0037] (3) Assembly process: First, install the main sealing ring inside the sealing groove, ensuring the pre-tightening spring is facing correctly; then install the isolation sealing ring outside the sealing groove; next, place the pressure equalizing gasket; finally, install the clamping flange. A graded clamping method is used during assembly: first, pre-tighten with a torque of 5 N·m and measure the uniformity of the gap; then, perform a secondary clamping with a torque of 10 N·m; finally, perform a final clamping with a torque of 15 N·m, so that the compression rate of the sealing ring is controlled within the range of 15%-20%. For threaded clamping structures, the compression amount is controlled by measuring the distance between the end face of the gland and the end face of the cylinder.

[0038] (4) Leakage Test: After assembly, pressure resistance and leakage tests are performed. The test medium is nitrogen, the test pressure is 2.5 MPaG, and the pressure holding time is 30 minutes. A helium mass spectrometer leak detector is used to detect the leakage rate, which is required to be ≤1×10⁻⁶. -6 Pa·m³ / s. After passing the test, acetylene operation condition verification is performed. The test pressure can be 1.1 to 1.5 times the design pressure, adjusted according to the component's pressure resistance rating.

[0039] The membrane module (effective membrane area 0.15 m²) with the above sealing structure maintained stable sealing performance and a leakage rate ≤1×10⁻⁶ after 30 days of continuous operation at a pressure of 2.5 MPaG. -7 Pa·m³ / s. After a 40-day corrosion test in an acetylene atmosphere containing H₂S (1000 ppm), the sealing ring showed no obvious swelling, hardening, or chemical degradation, and the sealing performance remained good. A membrane module (effective membrane area 0.5 m²) using a threaded compression structure and alternative materials showed stable sealing performance and a leakage rate ≤5 × 10⁻⁶ after 40 days of continuous operation at 2.0 MPaG pressure. -7 Pa·m³ / s, and its performance remained good after 35 days of corrosion testing.

[0040] Example 2 This embodiment is basically the same as Embodiment 1, except that the modular design of the sealing structure allows for scalable manufacturing to accommodate different membrane area configurations. For example... Figure 2 The thread clamping method shown is also applicable to the modular design concept of this embodiment.

[0041] To enable membrane modules with different membrane areas (such as 5cm², 45cm², 0.15m², and 0.5m²) to share the same sealing interface, this embodiment adopts a modular end cap and standardized sealing groove size design.

[0042] (1) Standardized sealing groove dimensions: For membrane modules of different specifications, the end sealing groove adopts a uniform width (8mm) and depth (4.5mm) design to ensure that the sealing ring specifications are uniform. The position of the sealing groove is kept at a fixed distance from the center line of the membrane element, so that the end caps of different specifications are interchangeable.

[0043] (2) Modular end caps: For small-scale pilot production (membrane area 5cm², 45cm²), an integrated end cap design is adopted, with the end cap connected to the cylinder via clamps; for pilot-scale and industrial side-line production (membrane area 0.15m², 0.5m²), a split end cap design is adopted, with the end cap connected to the cylinder via flanges. The sealing groove dimensions and sealing ring specifications of the two types of end caps are exactly the same, only the external connection method is different.

[0044] (3) Uniform sealing ring specifications: The main sealing ring and the isolation sealing ring adopt a uniform cross-sectional diameter of 5.3mm, and the circumference of the sealing ring is adjusted only according to the diameter of the membrane module cylinder. The material formula and vulcanization process are kept consistent to ensure consistent performance.

[0045] To ensure consistent sealing performance across membrane modules of different specifications, this embodiment also establishes a standardized assembly process: a graded tightening method is uniformly adopted, with the final tightening torque converted to an equivalent linear pressure based on the flange or thread specifications. The target linear pressure is 80-100 N / mm, ensuring consistent sealing ring compression rates across different module specifications, controlling the sealing ring compression rate within the range of 15%-20%. A helium mass spectrometer leak detector is uniformly used for testing, with the test pressure uniformly set at 1.1 times the module design pressure, the pressure holding time uniformly set at 30 minutes, and the leakage rate standard uniformly set at ≤1×10⁻⁶. -6 Pa·m³ / s.

[0046] Three sets of membrane modules of four sizes (5cm², 45cm², 0.15m², and 0.5m²) with modular sealing structures were selected for testing. The test results showed that the sealing performance of the four module sizes was consistent, with initial leakage rates all ≤5×10⁻⁶. -8 After 30 days of continuous operation, the leakage rate was ≤1×10 Pa·m³ / s. -7 Pa·m³ / s, with a standard deviation of less than one order of magnitude, proves the feasibility of modular design.

[0047] Example 3 This embodiment is basically the same as Embodiment 1, except for the structural optimization of the main sealing ring and the material modification of the isolation sealing ring. The sealing structure of this embodiment can be referred to... Figure 1 or Figure 2 The structure shown differs in the specific form of the sealing ring.

[0048] In this embodiment, the main sealing ring uses a uniquely shaped sealing ring with a double-lip structure, instead of a simple O-ring. This uniquely shaped sealing ring has an X-shaped cross-section, with a width of 6mm and a height of 5mm, and features two sealing lips forming an oil reservoir between them. The sealing lips and the wall of the sealing reservoir form two sealing lines, improving sealing reliability. The oil reservoir can be filled with grease to reduce assembly friction and extend the sealing ring's lifespan. An embedded stainless steel spring with a diameter of 0.3mm and a pitch of 1mm provides initial sealing force, ensuring effective sealing even under low-pressure conditions.

[0049] As variations of irregularly shaped sealing rings, Y-shaped or U-shaped sealing rings can also be used, also featuring double-lip or multi-lip structures, selectable according to specific operating conditions. Y-shaped sealing rings are suitable for unidirectional pressure sealing, while U-shaped sealing rings are suitable for reciprocating motion sealing.

[0050] To improve the corrosion resistance of the sealing ring in H2S-containing environments, this embodiment involves surface modification of the fluororubber material. The specific modification method is as follows: (1) Plasma pretreatment: Place the fluororubber sealing ring in the plasma treatment equipment and perform surface cleaning in an argon atmosphere for 5 minutes with a power of 200W.

[0051] (2) Surface grafting: The pretreated sealing ring is immersed in an ethanol solution containing 1 wt% perfluoroalkyl silane coupling agent, reacted at 60°C for 2 hours, and then cured at 120°C for 1 hour to form an oleophobic and hydrophobic surface layer.

[0052] (3) Post-treatment: Ultrasonic cleaning with anhydrous ethanol for 10 minutes to remove unreacted substances, and then drying at 80°C for 2 hours.

[0053] A membrane module (effective membrane area 0.15 m²) employing an X-shaped main seal ring and a surface-modified isolation seal ring exhibited stable sealing performance and a leakage rate ≤1×10⁻⁶ after 40 days of continuous operation at a pressure of 3.0 MPaG. -8 Pa·m³ / s. After 50 days of corrosion testing in an acetylene atmosphere containing H₂S (concentration 2000 ppm), the surface of the isolation sealing ring showed no obvious corrosion marks, with a Shore hardness change ≤3A and a mass change rate ≤0.5%, demonstrating excellent corrosion resistance. The double-lip structure of the X-shaped main sealing ring maintained an effective seal throughout the test, with no leakage observed.

[0054] Example 4 This embodiment provides the application and quality control method of the sealing structure in the overall sealing system of the membrane module. For example... Figure 2As shown in the figure, the sealing structure of this embodiment integrates a leakage monitoring system. The figure shows the structural relationship between the leakage guide channel, the gas collection main pipe, the acetylene concentration sensor and pressure sensor, and the alarm unit.

[0055] The sealing structure of this embodiment is not only applied to the connection between the membrane element and the end cap, but also extended to the air inlet, permeate outlet, residual gas outlet, and sensor interface. Specifically, the air inlet and residual gas outlet adopt the same double-layer sealing structure as in Embodiment 1; the permeate outlet adopts a single-layer main sealing ring (fluororubber) with a leakage monitoring interface, simplifying the design while retaining the leakage monitoring function; the sensor interface adopts a conical sealing structure with a metal sealing gasket.

[0056] All leakage guide channels from the interfaces converge into the main gas collection pipe, which is equipped with an acetylene concentration sensor and a pressure sensor. When a minor leak occurs in the main seal of any interface, the leaking medium enters the leakage guide channel and flows into the main gas collection pipe. The sensors can monitor the increase in acetylene concentration or pressure in real time, triggering an alarm and enabling centralized monitoring and early warning of leaks.

[0057] To ensure product quality, this embodiment also establishes a quality control method: (1) Sealing groove processing quality: The dimensions of the sealing groove were measured using an optical measuring instrument. The width tolerance was ±0.03mm, the depth tolerance was ±0.03mm, and the bottom roughness Ra was ≤0.4μm. Three circumferential positions were measured for each sealing groove, and the average value was taken.

[0058] (2) Sealing ring quality: Each batch of sealing rings will be randomly sampled for inspection. The test items include: Shore hardness (target value ±5A), tensile strength (≥12MPa), compression set (≤25%), and mass change rate (≤1%). The inspection frequency is 10% per batch.

[0059] (3) Assembly quality: Monitor the clamping torque or clamping displacement during the assembly process and record the assembly parameters of each seal. After assembly, perform an airtightness test on 100% of the seals. The test pressure is 1.1 times the design pressure and the pressure holding time is 15 minutes.

[0060] Establish a sealing structure quality file for each membrane module, recording sealing groove processing data, sealing ring batch information, assembly data, and test data to facilitate quality traceability and continuous improvement.

[0061] A 0.5 m² membrane module using the integrated sealing system of this embodiment operated continuously for 60 days at a pressure of 2.5 MPaG, with stable sealing performance at all interfaces and no acetylene leakage detected in the main gas collection pipe. In simulated leakage tests (bypass artificially activating to simulate leakage), the sensor responded within 5 seconds, triggering an audible and visual alarm, demonstrating the effectiveness of the leakage monitoring system. The first-pass yield rate of 50 membrane modules produced using the quality control method of this embodiment increased from 85% to 96%, and the seal failure rework rate decreased from 8% to 2%.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A sealing structure for a high-pressure and corrosion-resistant acetylene purification membrane module, characterized in that, include: The membrane element support cylinder has a sealing groove at its end; An end clamping assembly is disposed at the end of the membrane element support cylinder and is used to provide clamping force; A double-layer sealing ring is disposed in the sealing groove. The double-layer sealing ring includes a main sealing ring and an isolation sealing ring arranged sequentially along the axial direction. An annular isolation cavity is formed between the main sealing ring and the isolation sealing ring. A leakage guidance channel connects the annular isolation cavity to an external safety collection port; The end clamping assembly includes a limiting step and a pressure equalizing pad. The limiting step is used to limit the clamping stroke, and the pressure equalizing pad is disposed between the end clamping assembly and the double-layer sealing ring to ensure that the end face is subjected to uniform force.

2. The sealing structure according to claim 1, characterized in that, The main sealing ring is made of a pressure-resistant, low-permeability elastic material, and the isolation sealing ring is made of a chemically resistant material; the main sealing ring is made of fluororubber or EPDM rubber, and the isolation sealing ring is made of perfluoroether rubber or fluororubber.

3. The sealing structure according to claim 1, characterized in that, The leakage guide channel is provided on the end clamping assembly or on the membrane element support cylinder; the main sealing ring is provided with a pre-tightening spring to provide initial sealing force.

4. The sealing structure according to claim 1, characterized in that, The main sealing ring is an irregularly shaped sealing ring with an X-shaped cross-section and double sealing lips; the end clamping assembly adopts a flange clamping structure or a threaded clamping structure.

5. The sealing structure according to claim 1, characterized in that, The sealing groove has a width of 8-9 mm, a depth of 4.5-5.0 mm, and a surface roughness Ra≤0.8 μm at the bottom of the groove. The dimensions of the sealing groove are standardized and suitable for membrane modules with membrane areas of 5 cm², 45 cm², 0.15 m², or 0.5 m².

6. A method for preparing a sealing structure for a high-pressure and corrosion-resistant acetylene purification membrane module as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. End sealing groove processing: Precision processing of the sealing groove at the end of the membrane element support cylinder to control dimensional tolerances and surface roughness; S2. Sealing ring molding and vulcanization: The main sealing ring and the isolation sealing ring are molded separately and subjected to secondary vulcanization treatment; S3. Assembly: Install the main sealing ring and the isolation sealing ring into the sealing groove in sequence, place the pressure equalizing gasket, install the end clamping assembly, and tighten in stages according to the preset torque. S4. Leakage Test: After assembly, a pressure resistance and leakage test will be conducted. The test pressure is 1.1 times the design pressure, and the leakage rate should be ≤1×10⁻⁶. -6 Pa·m³ / s.

7. The preparation method according to claim 6, characterized in that, In the processing step of the end sealing groove, a CNC lathe is used for processing, and the processing accuracy is controlled within ±0.05mm. After processing, ultrasonic cleaning is performed and drying is carried out at 80℃ for 30 minutes.

8. The preparation method according to claim 6, characterized in that, In the sealing ring forming and vulcanization steps, the forming temperature is 170℃, the pressure is 15MPa, and the vulcanization time is 10 minutes; the secondary vulcanization treatment is carried out at 200℃ for 4 hours. In the assembly process, the graded tightening includes: first, pre-tightening with a torque of 5 N·m, then secondary tightening with a torque of 10 N·m, and finally final tightening with a torque of 15 N·m, so that the compression rate of the sealing ring is controlled within the range of 15%-20%.

9. The preparation method according to claim 6, characterized in that, In the leakage test procedure, the test medium is nitrogen gas, the pressure holding time is 30 minutes, and the leakage rate is detected by a helium mass spectrometer.

10. A high-pressure and corrosion-resistant acetylene purification membrane module, characterized in that, The sealing structure includes any one of claims 1 to 5, wherein the effective membrane area of ​​the membrane module is greater than 0.15 m², the pressure resistance is greater than 5.1 MPa, and the corrosion resistance time against H2S impurities in acetylene is greater than 40 days.

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