air separation unit

Abstract

This application relates to an air separation unit, including a purifier containing a molecular sieve for adsorbing impurities in the air; a cross-line purging device including a cross-line tube and a pressurizing tube, the two ends of which are connected to the inlet and outlet of the molecular sieve of the purifier, respectively, to short-circuit the molecular sieve through the cross-line tube for explosive purging, preventing gas from directly passing through the molecular sieve; the pressurizing tube is connected to the cross-line tube to provide pressurized gas to the cross-line tube; and a rupture disc device is installed on the cross-line tube to control the purging pressure to not exceed a preset pressure. This invention, through the coordinated operation of the purifier and the cross-line purging device, achieves efficient and safe explosive purging of the purification system in the air separation unit, preventing gas from directly passing through the molecular sieve and effectively solving the technical problem of low purging efficiency.

Description

Technical Field

[0001] This invention relates to the field of air separation equipment technology, and more particularly to an air separation equipment. Background Technology

[0002] In large-scale air separation units, molecular sieve purification systems play a crucial role. They are responsible for adsorbing and removing impurities such as H2O (water), CO2 (carbon dioxide), acetylene, propylene, propane, heavy hydrocarbons, and N2O (nitrous oxide) from the air to ensure the efficiency and stability of subsequent air separation processes. Traditional molecular sieve purification systems employ horizontal or vertical axial flow molecular sieve adsors. However, with technological advancements and the increasing need for space-saving solutions, vertical radial flow molecular sieve adsors have become widely used due to their simpler structure, lower resistance, and significantly reduced footprint.

[0003] The adsorbent bed inside the vertical radial flow molecular sieve adsorber is divided into two layers: the outer layer is Al2O3 (alumina) and the inner layer is molecular sieve. This design can effectively extend the service life of the adsorbent. At the same time, it has long-cycle operation, automatic adsorption cycle switching and shock-free switching control technology, which enables the molecular sieve purification system to operate continuously for up to 6 years. It solves the problem of fluidization danger in traditional molecular sieve adsorption systems and significantly reduces energy consumption.

[0004] However, the internal structure of the molecular sieve purification system is a wire mesh type, which cannot withstand the impact force generated during explosive purging. Therefore, molecular sieve purging has always been a technical challenge during the installation and commissioning of air separation units. The traditional approach involves routine pre-purging of the pipelines before and after the purifier. After the air compressor commissioning is completed, the purification and pre-cooling systems pass the initial purging, and the outlet pipeline cleanliness meets the requirements, the unit is temporarily shut down to load the molecular sieve. Then, the unit is restarted for a secondary purging of the purifier to ensure the safety and performance of the molecular sieve. While this method meets the safety requirements of the molecular sieve, the process of shutting down the unit to load the molecular sieve after the pipeline purging is successful, followed by restarting the unit for a secondary purging, consumes significant commissioning resources and time, resulting in low purging efficiency. Summary of the Invention

[0005] The main objective of this invention is to provide an air separation unit to solve the technical problem of low purging efficiency in existing air separation units.

[0006] To achieve the above objectives, according to the present invention, an air separation device is provided, comprising a purifier containing a molecular sieve for adsorbing impurities in the air; a cross-line purging device including a cross-line tube and a pressurizing tube, the two ends of the cross-line tube being connected to the inlet and outlet of the molecular sieve of the purifier, respectively, to short-circuit the molecular sieve through the cross-line tube for explosive purging, preventing gas from directly passing through the molecular sieve; the pressurizing tube being connected to the cross-line tube to provide pressurized gas to the cross-line tube; and a rupture disc device disposed on the cross-line tube for controlling the purging pressure to not exceed a preset pressure.

[0007] Furthermore, the rupture disc device includes a rupture disc disposed inside the cross-line pipe, and the rupture disc is provided with an explosion-proof notch.

[0008] Furthermore, the explosion-proof notch on the rupture disc is a cross-shaped notch.

[0009] Furthermore, the thickness of the explosion-proof sheet ranges from 2mm to 6mm.

[0010] Furthermore, the air separation unit also includes a baffle structure for isolating the interior of the molecular sieve from the outside environment, with baffle structures installed at both the inlet and outlet valves of the molecular sieve.

[0011] Furthermore, the diameter of the cross-line conduit ranges from 0.8m to 1.2m.

[0012] Furthermore, the preset pressure is 70% to 80% of the maximum pressure that the connecting pipeline of the air separation unit can withstand.

[0013] Furthermore, there are multiple purifiers connected in parallel. The air separation unit also includes an inlet manifold and an outlet manifold. The inlets of multiple purifiers are all connected to the inlet manifold, and one end of the cross-line pipe is connected to the inlet manifold. The outlets of multiple purifiers are all connected to the outlet manifold, and the other end of the cross-line pipe is connected to the outlet manifold. The inlet manifold is used to connect to the air-cooled tower inlet pipe, and the outlet manifold is used to connect to the plate heat exchanger and the booster inlet pipe.

[0014] Furthermore, the manifold inlet pipeline is equipped with multiple inlet valve assemblies, which are connected to the inlets of the corresponding purifiers through each inlet valve assembly. Each inlet valve assembly includes two inlet valves connected in pairs. And / or, the manifold outlet pipeline is equipped with multiple outlet valves, which are connected to the outlets of the corresponding purifiers through each outlet valve.

[0015] Furthermore, there are two purifiers and two inlet valve assemblies, and the cross-line pipe and pressurization pipe are connected to the pipe section of the manifold inlet pipe located between the two inlet valve assemblies.

[0016] Applying the technical solution of this invention, the purifier is a key component in the air separation device, used to remove impurities from the air, such as water vapor, carbon dioxide, and hydrocarbons, to ensure the efficiency and safety of subsequent air separation processes. The molecular sieve, as the core adsorbent material inside the purifier, deeply purifies the incoming air; however, due to its structural fragility, it needs to avoid direct impact from high-pressure gas. The cross-line purging device, through the coordinated operation of the cross-line pipe and the pressurization pipe, achieves independent purging of the pipes before and after the purifier. The cross-line pipe is connected to the inlet and outlet of the molecular sieve at both ends, allowing high-pressure gas to bypass the molecular sieve for circulating purging, while the pressurization pipe provides sufficient gas pressure to ensure purging effectiveness. This invention, through the coordinated operation of the purifier and the cross-line purging device, achieves efficient and safe explosive purging of the purification system in the air separation unit, avoiding direct gas passage through the molecular sieve and effectively solving the technical problem of low purging efficiency. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0018] Figure 1 A process flow diagram of one embodiment of the air separation unit according to the present invention is shown.

[0019] The above figures include the following reference numerals:

[0020] 1. Purifier; 11. Molecular sieve; 12. Inlet; 13. Outlet; 2. Cross-line pipe; 3. Pressurization pipe; 4. Inlet valve assembly; 41. Inlet valve; 5. Outlet valve; 6. Inlet manifold; 61. Air-cooled tower drain pipe; 7. Outlet manifold; 71. Plate heat exchanger line; 72. Booster inlet pipe. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0023] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0024] like Figure 1 As shown, this application provides an air separation device, including a purifier 1 containing a molecular sieve 11 for adsorbing impurities in the air; a cross-line purging device including a cross-line tube 2 and a pressurizing tube 3, the two ends of the cross-line tube 2 being connected to the inlet 12 and outlet 13 of the molecular sieve 11 of the purifier 1, respectively, to short-circuit the molecular sieve 11 through the cross-line tube 2 for explosive purging, preventing gas from passing directly through the molecular sieve 11; the pressurizing tube 3 being connected to the cross-line tube 2 to provide pressurized gas to the cross-line tube 2; and a rupture disc device, installed on the cross-line tube 2, for controlling the purging pressure to not exceed a preset pressure.

[0025] The air separation unit provided in this embodiment of the invention achieves efficient and safe explosive purging of the purification system in the air separation unit through the coordinated operation of the purifier 1 and the cross-line purging device, avoiding the direct passage of gas through the molecular sieve 11 and effectively solving the technical problem of low purging efficiency.

[0026] In the above embodiments, the purifier 1 is a key component of the air separation device, used to remove impurities from the air, such as water vapor, carbon dioxide, and hydrocarbons, to ensure the efficiency and safety of subsequent air separation processes. The molecular sieve 11, as the core adsorbent material inside the purifier 1, performs deep purification of the incoming air; however, due to its structural fragility, it needs to avoid direct impact from high-pressure gas. The cross-line purging device, through the coordinated operation of the cross-line pipe 2 and the pressurizing pipe 3, achieves independent purging of the pipes before and after the purifier 1. The cross-line pipe 2 is connected at both ends to the inlet 12 and outlet 13 of the molecular sieve 11, respectively, allowing high-pressure gas to bypass the molecular sieve 11 for circulating purging, while the pressurizing pipe 3 provides sufficient gas pressure to ensure the purging effect.

[0027] This design not only improves purging efficiency but also protects the molecular sieve 11 from direct impact by high-pressure gas, extending its service life. It is suitable for air separation units of various sizes, and is particularly effective in large-scale industrial oxygen production, significantly improving production efficiency and safety. By installing cross-line purging devices at the inlet 12 and outlet 13 of the molecular sieve 11, rapid and effective purging with high-pressure gas can be performed during molecular sieve 11 switching. This not only reduces switching time but also prevents direct impact of high-pressure gas on the molecular sieve 11, preventing structural damage and extending its service life. This design is particularly suitable for large-scale industrial oxygen production environments requiring continuous and stable gas supply, such as steel mills and chemical plants, significantly increasing oxygen yield and purity while reducing production costs.

[0028] Furthermore, the rupture disc device includes a rupture disc disposed within the cross-pipe 2, and the rupture disc has an explosion-proof notch. By providing an explosion-proof notch on the rupture disc, it can automatically rupture when the pressure exceeds a preset value, releasing excess pressure and preventing equipment damage. This safety mechanism is particularly crucial in industries such as chemical, oil, and natural gas, ensuring the safety of the production process. The design of the explosion-proof notch considers both material strength and pressure release efficiency, ensuring timely and effective prevention of pressure overload under any circumstances, protecting equipment from damage. This safety mechanism is essential for high-risk industries such as chemical, oil, and natural gas, significantly reducing the incidence of safety accidents and protecting the safety of personnel and equipment.

[0029] Furthermore, the explosion-proof notch on the rupture disc is a cross-shaped notch. This cross-shaped notch design ensures that the rupture disc fractures uniformly when the pressure exceeds a preset value, avoiding irregular fractures caused by localized stress concentration. This further enhances the safety and reliability of the equipment, making it suitable for industrial environments requiring high-precision pressure control. The cross-shaped notch design considers the uniformity of pressure release and the stress distribution of the material, ensuring stable pressure release and reliable equipment operation. This design performs particularly well in industrial environments requiring high-precision pressure control, such as semiconductor manufacturing and fiber optic production, effectively preventing product quality degradation caused by pressure fluctuations.

[0030] Furthermore, the thickness of the rupture disc ranges from 2mm to 6mm. By controlling the thickness of the rupture disc, its burst pressure can be precisely adjusted, ensuring timely pressure release when needed, while maintaining sufficient strength under normal operating conditions. This design is highly practical in high-pressure gas handling systems, effectively preventing safety accidents caused by excessive pressure. The thickness of the rupture disc directly affects its burst pressure and strength. The 2mm to 6mm thickness range has been verified through extensive experimentation, ensuring that in high-pressure gas handling systems, the rupture disc can quickly and reliably burst and release pressure when needed, while maintaining sufficient strength under normal operating conditions to prevent accidents. This design is particularly suitable for the production processes of high-pressure oxygen, nitrogen, argon, and other industrial gases, significantly improving production safety.

[0031] Furthermore, the air separation unit also includes a baffle structure for isolating the interior of the molecular sieve 11 from the external environment. Baffle structures are installed at both the inlet valve 41 and the outlet valve 5 of the molecular sieve 11. The baffle structure effectively prevents external impurities from entering the molecular sieve 11 during purging, thus affecting its adsorption performance. Simultaneously, it prevents adsorbent leakage within the molecular sieve 11 during normal operation. This design is suitable for industrial applications requiring high-purity gases, such as semiconductor manufacturing and optical fiber production, significantly improving gas purity and production efficiency. The baffle structure not only prevents the intrusion of external impurities during molecular sieve 11 switching or explosive purging but also ensures that the adsorbent inside the molecular sieve 11 does not leak during normal operation, maintaining high gas purity. This design is particularly suitable for industrial applications with extremely high gas purity requirements, such as semiconductor manufacturing and optical fiber production, effectively improving product quality and production efficiency while reducing production costs.

[0032] Furthermore, the diameter of the cross-pipe 2 ranges from 0.8m to 1.2m. By selecting an appropriate cross-pipe 2 diameter, it is ensured that the gas can pass through quickly and evenly during blasting purging, improving purging efficiency while reducing impact on the pipeline. This is suitable for large-scale air separation units and can significantly improve production efficiency. The 0.8m to 1.2m cross-pipe 2 diameter range has been carefully designed and verified to ensure rapid gas flow during short-circuit purging, improving purging efficiency, while avoiding excessive impact of high-pressure gas on the pipeline and extending the service life of the equipment. This design is particularly suitable for large-scale air separation units, such as oxygen and nitrogen production lines with an annual output of tens of thousands of tons, and can significantly improve production efficiency and equipment operational stability.

[0033] Furthermore, the preset pressure is 70% to 80% of the maximum pressure that the connecting pipeline of the air separation unit can withstand. By reasonably setting the preset pressure, the best purging effect can be achieved while ensuring pipeline safety. This is suitable for various industrial gas processing systems, such as the production of oxygen, nitrogen, and argon, and can effectively improve gas purity and production efficiency. The preset pressure setting is based on the safe pressure range of the connecting pipeline, ensuring that the pressure will not exceed the safe bearing range of the pipeline during explosive purging, while achieving the best purging effect and improving gas purity. This design is suitable for various industrial gas processing systems, such as the production of oxygen, nitrogen, and argon, and can effectively improve production efficiency and reduce production costs, especially suitable for industrial environments requiring continuous and stable gas supply.

[0034] Furthermore, there are multiple purifiers 1 connected in parallel. The air separation unit also includes an inlet manifold and an outlet manifold 7. The inlets 12 of all the purifiers 1 are connected to the inlet manifold, and one end of the cross-line pipe 2 is connected to the inlet manifold. The outlets 13 of all the purifiers 1 are connected to the outlet manifold 7, and the other end of the cross-line pipe 2 is connected to the outlet manifold 7. The inlet manifold is used to connect to the air-cooled tower inlet pipe 61, and the outlet manifold 7 is used to connect to the plate heat exchanger line 71 and the booster inlet line 72. This parallel arrangement of the purifiers 1 and the manifold design can improve the processing capacity and flexibility of the air separation unit, and is suitable for industrial applications that require continuous and stable gas supply, such as steel smelting and chemical synthesis, which can significantly improve production efficiency and product quality. The parallel arrangement of the purifiers 1 and the connection method of the manifold not only improve the efficiency of gas processing, but also enhance the flexibility and stability of the system. This design is particularly suitable for industrial applications that require a continuous and stable gas supply, such as steel smelting and chemical synthesis. It can significantly improve production efficiency, ensure a continuous gas supply, improve product quality, and reduce production costs.

[0035] Furthermore, multiple inlet valve groups 4 are installed on the manifold inlet 12 pipeline, which is connected to the inlet 12 of the purifier 1 corresponding to each inlet valve group 4. Each inlet valve group 4 includes two inlet valves 41 connected in pairs. And / or, multiple outlet valves 5 are installed on the manifold outlet 13 pipeline, which is connected to the outlet 13 of the corresponding purifier 1 through each outlet valve 5. By setting multiple inlet valve groups 4 and outlet valves 5, independent control of the purifier 1 can be achieved, improving the operating efficiency and safety of the equipment. This design is suitable for industrial applications requiring high-precision gas control, such as the electronics and medical industries, effectively improving gas purity and equipment operational stability. The design of multiple inlet valve groups 4 and outlet valves 5 allows each purifier 1 to operate independently, improving equipment operating efficiency and safety. This design is particularly suitable for industrial applications requiring high-precision gas control, such as the electronics and medical industries, effectively improving gas purity, ensuring equipment operational stability, and improving product quality and production efficiency.

[0036] Furthermore, there are two purifiers 1 and two inlet valve groups 4. The crossover pipe 2 and the pressurizing pipe 3 are both connected to the pipe section of the manifold inlet 12 located between the two inlet valve groups 4. This design ensures that during blast purging, the gas can be evenly distributed to each purifier 1, improving purging efficiency and purification effect. It is suitable for industrial applications that require simultaneous processing of multiple gas streams, such as large chemical plants and oil refineries, significantly improving production efficiency and safety. By connecting the crossover pipe 2 and the pressurizing pipe 3 to the pipe section between the two inlet valve groups 4 of the manifold inlet 12, it is ensured that high-pressure gas can be evenly distributed to each purifier 1 during blast purging, improving overall purging efficiency and purification effect. This design is particularly suitable for large industrial applications that require simultaneous processing of multiple gas streams, such as chemical plants and oil refineries, significantly improving production efficiency, reducing production costs, and enhancing the overall system's operational safety.

[0037] In the above embodiment, the purging method involves constructing a pipeline from the inlet 12 of the molecular sieve 11 to the outlet 13 of the molecular sieve 11. To ensure the purging effect, this pipeline section uses a steel pipe with a diameter of 1m. First, the inlet 12 of the molecular sieve 11 is treated. Since the inlet 12 is supplied with gas from the air-cooled tower, treatment is relatively convenient. However, due to the special structure of the outlet 13 pipeline, and because it cannot be purged by explosive blowing through the molecular sieve 11 body, the aforementioned cross-line method is required for explosive blowing. When manually cleaning the molecular sieve 11, holes need to be drilled in the pipeline. Considering the special characteristics of the molecular sieve 11 pipeline, the number of holes is minimized. In this implementation, three operator access holes with a diameter of 600mm were drilled to ensure no dead corners are left during pipeline cleaning. After inspection, manual processing is carried out. After rectification and acceptance of any problems, the manholes are reinforced by welding. The outlet pipeline 13 of molecular sieve 11 is blasted and purged using the newly added cross-line. Only after the purging is accepted by the target can the molecular sieve 11 be loaded.

[0038] The purging steps using the above embodiments are as follows:

[0039] 1. Purging the inlet pipeline 72 from the purifier to the booster: Confirm that the temporary pressurization line 3 of the air-cooled tower and the jumper cable from the inlet to the outlet 13 of the purifier 1 are complete. Install the booster inlet short section and filter outlet (purge port #1). Install 5mm thick rupture discs (marked with a cross) on the pipeline side and add baffles to the equipment side. Close the inlet valves 2 / 4, 1 / 3, 5 / 6, start-up air valve, low-pressure air to plate heat exchanger valve, and booster valve of purifier 1. Isolate the root valves of instruments and components. Open the temporary pressurization valve V1 on-site and perform a rupture purging of the outlet 13 pipeline of purifier 1 to the inlet pipeline 72 of the booster. After passing the purging, close valve V1 and install a blind flange at purge port #1. Note: Closely monitor the pressure inside the pipeline using a temporary pressure gauge, controlling the pressure to <0.25MPa. Overpressure is strictly prohibited.

[0040] 2. Secondary purging of the purified air to low-pressure plate heat exchanger pipeline: Confirm that the temporary pressurization line 3 of the air-cooled tower and the jumper connection from the inlet to outlet 13 of purifier 1 are complete, the blow-off port of the booster compressor has been fitted with a blind flange, the short section before the low-pressure air to plate heat exchanger A is removed, a 5mm rupture disc (marked with a cross) is added to the blow-off port on the pipeline side, a baffle is added to the equipment side, a blind flange is added to the blow-off inlet short section flange, the inlet valve, inlet bypass valve, outlet valve, start-up air valve, and booster compressor valve of purifier 1 are all closed, the valve from the low-pressure air to the plate heat exchanger is opened, and the root valves of instruments and components are closed for isolation; on-site, open the temporary pressurization valve V1 and perform a burst purging of the pipeline from outlet 13 of purifier 1 to the inlet of the plate heat exchanger. After passing the test, close valve V1, reset the short section at the blow-off port and install a blind flange. Following this method, purge the low-pressure air to plate heat exchanger inlet pipeline sequentially.

[0041] 3. Perform blast purging on the pipeline from the waste nitrogen outlet 13 of the plate heat exchanger to the purification system: Confirm that the temporary pressurization line 3 of the air-cooled tower and the jumper from the inlet to outlet 13 of the purifier 1 are complete, the purging port of the booster compressor has been fitted with a blind flange, the flange of the waste nitrogen outlet of the plate heat exchanger is disconnected, a 3mm rupture disc is added to the purging port on the pipeline side (cross-shaped if necessary), a baffle is added to the equipment side, a blind flange is installed at the flange at the outlet of the plate heat exchanger, and the inlet valve 41, outlet valve 5, low-pressure air to plate heat exchanger valve, and waste nitrogen to other pipeline valves of purifier 1 are closed, and the root valves of instruments and components are closed for isolation; open the temporary pressurization valve V1 on site and perform blast purging on the pipeline from the waste nitrogen outlet 13 of the plate heat exchanger to the purification system. After passing the test, close the temporary pressurization valve, reset the purging port flange and install a blind flange. Following this method, purge the pipeline from the waste nitrogen outlet 13 of the plate heat exchanger to the purification system in sequence. Note: The pressure during pipeline blasting and purging should be controlled at <0.15MPa. Overpressure is strictly prohibited. Asbestos boards should be used as blasting plates, and the pressure should be charged and blasted according to the pressure mentioned above. To ensure effective blasting of the blasting plates, it is recommended to make cross-shaped cuts to guarantee the blasting effect.

[0042] The following precautions should be taken during the purging process:

[0043] (1) When purging the pipeline, the kinetic energy of the purging medium must be greater than that of the medium under normal conditions. Explosive purging should be used. (2) The purging pressure should be the design pressure of the low-pressure pipeline, and the purging temperature should be within the design temperature range of the pipeline. (3) When purging, the main pipe should be purged first, followed by the branch pipe. Only after the upstream pipeline has been purged clean and confirmed to be qualified can the next section of the pipeline be purged. (4) Instrument pipes must be opened for purging in the later stage of the main pipeline purging. (5) Before purging, the firmness of the pipeline supports and hangers should be checked, and they should be reinforced if necessary. (6) The connection between the removed short pipe and the equipment flange should be blinded with baffles or blind flanges to prevent foreign objects from entering. (7) When purging the pipeline, operators should operate slowly when opening and closing valves, take good self-protection measures, and are prohibited from operating directly in front of valves or pipeline purging ports.

[0044] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0045] 1. This solves the problem of gas entering the molecular sieve 11 during purging, ensuring the safety of the molecular sieve 11.

[0046] 2. During purging, the inlet and outlet valves of molecular sieve 11 are closed, and the high-efficiency blasting purging ensures the cleanliness of the pipeline purging.

[0047] 3. It avoids secondary unit shutdowns, saving commissioning time and costs. The jumper purging method effectively resolves the contradictions that exist during commissioning, saving steam consumption and significant amounts of manpower, resources, and time.

[0048] 4. The cross-connection purging method effectively solves the contradictions that exist during the commissioning process. It can save steam consumption, save a lot of manpower, material resources and time, reduce the actual vehicle cost, save commissioning funds, speed up the purging progress and improve purging efficiency.

[0049] By applying the technical solution of this invention, the coordinated operation of the purifier 1, the cross-line purging device, the rupture disc device, and the baffle structure not only solves the problems of low purging efficiency and easy damage to molecular sieve 11 in traditional air separation units, but also greatly improves the operating efficiency and safety of the entire system. Especially in large-scale industrial oxygen production, chemical synthesis, electronics industry, and medical gas supply, this design can significantly improve gas purity, reduce production costs, and enhance the operational stability and safety of equipment, demonstrating broad application prospects and significant economic benefits. By precisely controlling the rupture pressure of the rupture disc, the diameter of the cross-line pipe 2, and the parallel connection of the purifier 1, the technical solution of this invention can adapt to air separation units of different scales and types, providing an efficient, safe, and reliable solution for industrial gas production. It is applicable to various scenarios from small laboratory-level equipment to large industrial production lines. Whether producing oxygen, nitrogen, or argon, it can effectively improve gas purity, reduce energy consumption, and enhance the operating efficiency and safety of equipment, bringing revolutionary technological progress to the industrial gas production industry.

[0050] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0051] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An air separation unit, characterized in that, include: Purifier (1), including molecular sieve (11), for adsorbing impurities in the air; The cross-line purging device includes a cross-line tube (2) and a pressurizing tube (3). The two ends of the cross-line tube (2) are respectively connected to the inlet (12) and outlet (13) of the molecular sieve (11) of the purifier (1) so as to short-circuit the molecular sieve (11) through the cross-line tube (2) for explosive purging and to prevent gas from passing directly through the molecular sieve (11). The pressurizing tube (3) is connected to the cross-line tube (2) to provide pressurizing gas to the cross-line tube (2). A rupture disc device is installed on the cross-line pipe (2) to control the pressure during purging to not exceed a preset pressure. The air separation unit also includes a baffle structure for isolating the interior of the molecular sieve (11) from the outside environment. The baffle structure is provided at both the inlet valve (41) and the outlet valve (5) of the molecular sieve (11). The purifier (1) is multiple and is arranged in parallel. The air separation unit also includes an inlet manifold (6) and an outlet manifold (7). The inlets (12) of the multiple purifiers (1) are all connected to the inlet manifold (6). One end of the cross-line pipe (2) is connected to the inlet manifold (6). The outlets (13) of the multiple purifiers (1) are all connected to the outlet manifold (7). The other end of the cross-line pipe (2) is connected to the outlet manifold (7). The inlet manifold (6) is used to connect to the air-cooled tower inlet pipe (61), and the outlet manifold (7) is used to connect to the plate heat exchanger (71) and the booster inlet pipe (72). The manifold inlet pipeline (6) is provided with multiple inlet valve groups (4), and the manifold inlet pipeline (6) is connected to the inlet (12) of the purifier (1) corresponding to each of the inlet valve groups (4). The inlet valve group (4) includes two inlet valves (41) connected in pairs; and / or, the manifold outlet pipeline (7) is provided with multiple outlet valves (5), and the manifold outlet pipeline (7) is connected to the outlet (13) of the corresponding purifier (1) through each of the outlet valves (5).

2. The air separation unit according to claim 1, characterized in that, The rupture disc device includes a rupture disc, which is disposed inside the cross-line pipe (2) and has an explosion-proof notch.

3. The air separation unit according to claim 2, characterized in that, The explosion-proof cut on the rupture disc is a cross-shaped cut.

4. The air separation unit according to claim 2, characterized in that, The thickness of the explosion-proof sheet ranges from 2mm to 6mm.

5. The air separation unit according to claim 1, characterized in that, The diameter of the cross-line pipe (2) ranges from 0.8m to 1.2m.

6. The air separation unit according to claim 1, characterized in that, The preset pressure is 70% to 80% of the maximum pressure that the connecting pipeline of the air separation unit can withstand.

7. The air separation unit according to claim 1, characterized in that, There are two purifiers (1) and two inlet valve groups (5). The cross-line pipe (2) and the pressurizing pipe (3) are connected to the pipe section of the manifold inlet pipe (6) located between the two inlet valve groups (4).

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