A negative pressure membrane separation helium extraction device and process

Abstract

The application discloses a kind of negative pressure membrane separation helium extraction equipment and process, belong to separation helium extraction equipment technical field, wherein a kind of negative pressure membrane separation helium extraction equipment includes the filter unit for filtering raw material gas, filter unit includes shell, pedestal, rotating frame, filter cartridge and elastic piece, filter cartridge is equipped with vibration protrusion, actuating portion is equipped on pedestal, filter cartridge can be rotated under the drive of rotating frame, and drive vibration protrusion intermittent impact actuating portion, to make itself vibrate under the action of elastic piece, to improve the difficulty of impurity attachment and blockage in raw material gas Filter pore.The negative pressure membrane separation helium extraction equipment provided by the application makes filter cartridge vibrate by the cooperation of vibration protrusion and actuating portion, effectively reduces the attachment and accumulation of impurities around filter cartridge filter pore, reduces the risk of filter element being blocked, so that raw material gas can smoothly pass through filter cartridge, maintain normal flow rate, to improve filtering efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of helium separation and extraction equipment, specifically relating to a negative pressure membrane separation and extraction equipment and process. Background Technology

[0002] Helium, as a rare gas, has very important applications in aerospace, defense, low-temperature superconductivity research, semiconductor production, nuclear magnetic resonance imaging, special metal smelting, and gas leak detection.

[0003] During the storage, transportation, and production of LNG, due to factors such as the intrusion of environmental heat and pressure changes, some LNG evaporates from a liquid state to a gaseous state, thus generating BOG feedstock gas (evaporation gas). BOG feedstock gas mainly consists of conventional natural gas components such as methane, and also contains trace amounts of helium. Extracting helium from BOG feedstock gas has significant economic and strategic value. During production and transportation, BOG feedstock gas inevitably carries dust and impurities generated by pipeline corrosion. Therefore, in the helium extraction process from BOG feedstock gas, the filtration stage in the pretreatment process is crucial, aiming to remove these impurities and lay the foundation for subsequent stable helium extraction operations.

[0004] Impurities tend to adhere to the surface of filter elements used to process BOG feedstock gas during operation. These impurities gradually accumulate around the pores of the filter element. Over time, once the filter element becomes clogged, it will not only reduce the gas flow rate and decrease the processing efficiency of BOG feedstock gas, but may also cause a large pressure difference before and after the filter element, affecting the operational stability of the helium extraction equipment.

[0005] In summary, providing a negative pressure membrane separation helium extraction device that can solve the problem of filter element clogging and improve helium extraction quality is of great significance and plays a key role in promoting the comprehensive utilization of resources in the LNG industry and meeting the demand for helium in various fields. Summary of the Invention

[0006] The purpose of this invention is to provide a negative pressure membrane separation helium extraction device and process to reduce the risk of filter element clogging in the raw gas pretreatment process.

[0007] According to one aspect, in order to achieve the above-mentioned objective, an embodiment of the present invention provides a negative pressure membrane separation helium extraction device, including a filtration unit for filtering raw material gas. The filtration unit includes a shell, a base, a rotating frame, a filter cartridge, and an elastic element. The shell has an air inlet and an air outlet. The base is disposed at the bottom of the shell. The rotating frame is rotatably disposed on the base. The filter cartridge is axially slidably disposed on the rotating frame and is capable of moving up and down relative to the rotating frame. The elastic element is located between the filter cartridge and the rotating frame. The filter cartridge is provided with a vibrating protrusion, and the base is provided with an actuating part. The filter cartridge can rotate under the drive of the rotating frame, and drive the vibrating protrusion to intermittently strike the actuating part, so that it generates lifting and lowering vibration under the action of the elastic element, so as to avoid impurities in the raw gas from adhering and clogging the filter pores.

[0008] In one possible implementation, the filter cartridge includes a support frame and a filter screen. The vibration protrusion is located at the lower part of the support frame. Both the support frame and the filter cartridge are cylindrical. The filter cartridge is fixedly sleeved on the outer periphery of the support frame. The support frame is provided with a downwardly extending guide rod. There are multiple guide rods spaced apart circumferentially. The guide rods pass through the rotating frame and slide with the rotating frame. The elastic element is a spring and is sleeved on the guide rod. The two ends of the spring act on the support frame and the rotating frame, respectively.

[0009] In one possible implementation, a gear ring is provided on the outer periphery of the rotating frame, and a gear is rotatably disposed inside the housing. The gear meshes with the gear ring and is used to drive an external motor to drive the rotating frame to rotate.

[0010] In one possible implementation, the bottom of the housing is provided with an upwardly extending support rod, the support rod having bristles that contact the surface of the filter screen, the bristles being able to provide circumferential cleaning force when the filter screen rotates and axial cleaning force when the filter screen vibrates up and down.

[0011] In one possible implementation, the air outlet is located at the bottom of the housing, the bottom of the base has a mounting hole communicating with the air outlet, a mounting ring is detachably disposed in the mounting hole, and a filter element is disposed in the filter screen extending downward into the mounting ring, so that the raw material gas passes through the filter screen and the filter element in sequence before being discharged from the air outlet.

[0012] In one possible implementation, the housing includes a main body and a base plate, the base plate being detachably disposed at the bottom of the main body, and the base, the gear, and the support rod all being disposed on the base plate.

[0013] In one possible implementation, the air inlet is arranged tangentially to the housing, and the inner wall of the housing is provided with a plurality of circumferentially spaced spiral guide vanes. The spiral guide vanes are used to guide the raw material gas and form a swirling flow so that liquid impurities in the raw material gas are thrown out under centrifugal force. The inner wall of the housing is provided with an annular liquid collection tank, which is located below the spiral guide vanes and is used to receive the thrown-out liquid impurities.

[0014] In one possible implementation, the outer wall of the housing is provided with an annular liquid collection box, the liquid collection tank is connected to the liquid collection box, and the bottom wall height of the liquid collection tank gradually decreases towards the liquid collection box.

[0015] In one possible implementation, the top of the liquid collection tank has a guide weir plate, the height of which gradually decreases towards the inner wall of the shell, and a slit is provided between the end of the guide weir plate and the inner wall of the shell for the liquid impurities to be thrown out to pass through.

[0016] According to another aspect, embodiments of the present invention also provide a negative pressure membrane separation helium extraction process, comprising the following steps: S1 Pretreatment: The raw gas is compressed by the compressor and filtered by the filter unit before entering the mixing tank for buffering; S2 primary separation: Gas enters the primary permeation membrane, non-permeable gas is discharged directly, and permeable gas enters the negative pressure storage tank; S3 Two-stage separation: The permeate gas in the negative pressure storage tank is pressurized by the Roots blower and enters the buffer tank. Then it is compressed a second time by the compressor and enters the second-stage permeate membrane. Before the non-permeate gas returns to the first-stage permeate membrane, the permeate gas is buffered and pressurized again. S4 dehydrogenation and dehydration: Hydrogen is removed through a catalytic reaction, and then water is removed through adsorption and desorption. S5 purification: Impurity gases are adsorbed by pressure swing adsorption, and the purge gas is returned to the front of the secondary permeate membrane to obtain the final product gas.

[0017] The significant technical effects of the embodiments of the present invention are as follows: The vibration of the filter cartridge is achieved by the cooperation of the vibrating protrusion and the actuator, which effectively reduces the adhesion and accumulation of impurities around the filter pores, lowers the risk of filter element blockage, and allows the raw material gas to pass through the filter cartridge smoothly and maintain a normal flow rate, thereby improving filtration efficiency and providing a stable supply of raw materials for the subsequent helium extraction process. Attached Figure Description

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

[0019] Figure 1 This is a schematic diagram of the structure of the filtering unit in one embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the internal structure of the middle shell at one angle; Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 for Figure 1 A schematic diagram of the internal structure of the middle shell from another angle; Figure 5 for Figure 4 Enlarged view at point B in the middle; Figure 6 for Figure 1 Schematic diagram of the middle filter cartridge; Figure 7 for Figure 1 Exploded view of the structure of the middle filter cartridge; Figure 8 This is a flowchart of a negative pressure membrane separation helium extraction process in one embodiment of the present invention.

[0020] In the diagram: 1. Shell, 2. Base, 3. Rotating frame, 4. Filter cartridge, 5. Elastic element, 101. Air inlet, 102. Air outlet, 6. Vibration protrusion, 7. Actuator, 401. Support frame, 402. Filter screen, 8. Guide rod, 9. Gear ring, 10. Gear, 11. Support rod, 12. Brush bristles, 201. Mounting hole, 13. Mounting ring, 14. Filter element, 103. Main body, 104. Base plate, 15. Spiral guide vane, 16. Liquid collection tank, 17. Liquid collection box, 18. Guide weir plate. Detailed Implementation

[0021] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0023] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0026] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation", "connection", "linking", and "fixing" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components.

[0028] Please see Figures 1-7 The illustration shows a negative pressure membrane separation helium extraction device according to an embodiment of the present invention, including a filter unit for filtering raw material gas, the filter unit including a housing 1, a base 2, a rotating frame 3, a filter cylinder 4 and an elastic element 5.

[0029] The housing 1 serves as the external protective structure for the filter unit, housing and protecting the internal components. The housing 1 has an inlet 101 and an outlet 102. The inlet 101 introduces the BOG raw material gas to be filtered, while the outlet 102 discharges the filtered gas. The base 2 is mounted on the bottom wall of the housing 1. A rotating frame 3 is rotatably mounted on the base 2. The filter cartridge 4 is axially slidably mounted on the rotating frame 3, allowing for axial displacement during rotation. The filter cartridge 4 intercepts dust, rust, and other impurities in the raw material gas.

[0030] A vibrating protrusion 6 is provided on the filter cartridge 4, and an actuating part 7 is provided on the base 2. The actuating part 7 is located on the moving trajectory of the vibrating protrusion 6. An elastic element 5 is provided between the filter cartridge 4 and the rotating frame 3 to provide elastic support for the filter cartridge 4. When the filter cartridge 4 rotates, the vibrating protrusion 6 impacts the actuating part 7, and the elastic element 5 can cause the filter cartridge 4 to undergo elastic deformation, thereby generating vibration.

[0031] During operation, BOG feed gas enters the housing 1 through inlet 101. Due to the pressure difference between the inside and outside of filter cartridge 4 (usually achieved through negative pressure generated by a subsequent negative pressure membrane separator), the feed gas flows from the outer wall of filter cartridge 4 to its interior. During this process, dust, rust, and other impurities in the feed gas are intercepted by the filter pores on the wall of filter cartridge 4, achieving filtration. The filtered gas exits the housing 1 from inside filter cartridge 4 through outlet 102, and proceeds to the subsequent helium extraction process.

[0032] During the filtration process, the rotating frame 3 rotates under the drive of an external drive device, causing the filter cartridge 4 to rotate as well. When the vibrating protrusion 6 on the filter cartridge 4 rotates to a position opposite to the actuator 7 on the base 2, the vibrating protrusion 6 impacts the actuator 7, transmitting the impact force to the filter cartridge 4, causing the filter cartridge 4 to vibrate under the action of the elastic element 5. The vibration causes impurities adhering to the filter pores of the filter cartridge 4 to be subjected to the vibration force, making it difficult for them to accumulate in the pores and reducing the possibility of impurities clogging the filter pores. As the filter cartridge 4 continues to rotate, the vibrating protrusion 6 intermittently impacts the actuator 7, maintaining a certain frequency of vibration in the filter cartridge 4, increasing the difficulty for impurities in the raw gas to adhere to and clog the filter pores.

[0033] The vibration of the filter cartridge 4 is achieved by the cooperation of the vibrating protrusion 6 and the actuator 7, which effectively reduces the adhesion and accumulation of impurities around the filter pores of the filter cartridge 4, reduces the risk of filter element blockage, and allows the raw material gas to pass through the filter cartridge 4 smoothly, maintaining a normal flow rate, thereby improving filtration efficiency and providing a stable supply of raw materials for the subsequent helium extraction process.

[0034] Please see Figures 2-7In a specific embodiment, the filter cartridge 4 consists of a support frame 401 and a filter screen 402, both of which are cylindrical. The filter screen 402 is fixedly sleeved on the support frame 401, which provides a support base for the filter screen 402, ensuring that the filter screen 402 can withstand gas pressure without deformation during filtration and guaranteeing structural strength. Multiple vertical guide rods 8 are spaced circumferentially on the support frame 401. The guide rods 8 pass through the rotating frame 3 and slide in cooperation with it, providing guidance for the axial sliding of the support frame 401 and ensuring the stability of the axial sliding of the support frame 401. In this design, the elastic element 5 is preferably a spring, sleeved on the guide rods 8, with both ends of the spring acting on the rotating frame 3 and the support frame 401, respectively. Vibration protrusion 6 is provided on the support frame 401. When the rotating frame 3 drives the support frame 401 to rotate, the impact force generated by the vibration protrusion 6 hitting the actuator 7 is transmitted to the spring through the support frame 401. The spring deforms rapidly, causing the filter cartridge 4 to vibrate. Multiple vibration protrusions 6 can be arranged at intervals along the circumference to obtain different vibration frequencies.

[0035] A gear ring 9 is provided on the outer periphery of the rotating frame 3, and a gear 10 is rotatably mounted inside the housing 1, meshing with the gear ring 9. An external motor is connected to the gear 10 via a conventional transmission component. The motor drives the gear 10 to rotate, and since the gear 10 meshes with the gear ring 9, the rotation of the gear 10 drives the gear ring 9 to rotate, ultimately realizing the rotation of the rotating frame 3. A conventional seal is used to seal the position where the gear 10 extends into the housing 1 to ensure that gas does not escape from this position.

[0036] A wear-resistant layer, such as ceramic or other wear-resistant materials, can be provided on the sliding mating surface between the guide rod 8 and the rotating frame 3 to reduce wear on the support frame 401 and the rotating frame 3, ensuring the normal use of the filter cartridge 4. A conventional buffer and shock-absorbing layer can also be provided on the contact surface between the two to absorb and buffer the energy generated by the vibration of the filter cartridge 4, reduce the transmission of vibration to other parts of the equipment, thereby reducing noise and improving the stability of equipment operation.

[0037] Please see Figure 2 and Figure 4In a specific embodiment, a support rod 11 is vertically arranged on the bottom wall of the housing 1 to provide support for the bristles 12, enabling them to stably contact the surface of the filter screen 402. When the rotating frame 3 drives the filter cylinder 4 to rotate, the filter screen 402 rotates accordingly. The bristles 12 generate circumferential friction on the surface of the filter screen 402. This circumferential cleaning force can clean the impurities attached to the surface of the filter screen 402 along the circumferential direction, causing the impurities to detach from the surface of the filter screen 402 and reducing the accumulation of impurities on the surface of the filter screen 402. During the rotation of the filter cylinder 4, the vibration protrusion 6 impacts the actuator 7, causing the filter cylinder 4 to vibrate vertically under the action of the elastic element 5. At this time, since the bristles 12 are in contact with the surface of the filter screen 402, the bristles 12 and the surface of the filter screen 402 generate axial relative displacement when the filter screen 402 vibrates vertically, thereby providing an axial cleaning force to the filter screen 402 and cleaning the impurities distributed along the axial direction of the filter screen 402.

[0038] The brush bristles 12 provide circumferential cleaning force when the filter screen 402 rotates and axial cleaning force when the filter screen 402 vibrates vertically, thus achieving cleaning of the filter screen 402 surface in different directions. This multi-directional cleaning method can more comprehensively and thoroughly remove impurities adhering to the filter screen 402 surface. Compared to single-directional cleaning, it can more effectively reduce impurity residue on the filter screen 402 surface, lower the risk of filter pore clogging, and maintain good filtration performance.

[0039] Please see Figure 4 and Figure 5 In a specific embodiment, the base 2 is provided with a mounting hole 201, which communicates with the air outlet 102. A mounting ring 13 is detachably mounted within the mounting hole 201, and a filter element 14 is mounted on the mounting ring 13. The filter element 14 is a sintered metal powder filter element 14, and the filter screen 402 is also a sintered metal filter screen 402. The combination of the filter screen 402 and the filter element 14 achieves staged filtration. The pore size of the sintered metal filter screen 402 is relatively large, suitable for intercepting larger particulate impurities first, playing a preliminary filtration role and reducing the filtration burden on the subsequent filter element 14. Meanwhile, the sintered metal powder filter element 14 has higher filtration precision, enabling further fine filtration of the gas after coarse filtration, thus improving the overall filtration effect.

[0040] The detachable connection between the mounting ring 13 and the mounting hole 201 of the base 2 facilitates the replacement and maintenance of the filter element 14. When the filter element 14 becomes clogged or its performance deteriorates after long-term use, the operator can easily remove the mounting ring 13 from the mounting hole 201 to clean and replace the filter element 14. Through dual filtration of coarse and fine filtration, impurities in the BOG feed gas can be removed more comprehensively and thoroughly, improving the quality of the filtered gas.

[0041] Please see Figure 2 and Figure 4In a specific embodiment, the housing 1 consists of two parts: a main body 103 and a base plate 104. The main body 103 is the primary outer shell structure, and the base plate 104 is detachably mounted on the bottom of the main body 103. The base 2, gear 10, and support rod 11 are mounted on the detachable base plate 104, achieving a modular design. During equipment operation, these components may require inspection, repair, or replacement. By mounting them on the detachable base plate 104, maintenance can be easily performed by simply removing the base plate 104 from the main body 103, thus simplifying the maintenance process.

[0042] Please see Figure 2 and Figure 4 As a specific embodiment, multiple spiral guide vanes 15 are arranged circumferentially on the inner wall of the shell 1 to guide the flow of the raw material gas. In order to improve the swirling effect, the air inlet 101 can be arranged tangentially to the shell 1. When the BOG raw material gas enters the shell 1 from the air inlet 101, it is subjected to the force of the spiral guide vanes 15 to generate rotational motion and flows along the spiral path of the spiral guide vanes 15 to form a swirling flow. The liquid impurities in the BOG raw material gas (including a small amount of incompletely evaporated LNG droplets and water generated by condensation during transportation) are thrown towards the inner wall of the shell 1 under the action of centrifugal force, realizing the separation of liquid impurities from gas.

[0043] Below the spiral guide vane 15, an annular liquid collection tank 16 is provided, surrounding the inner wall of the housing 1 to receive liquid impurities flowing down from the inner wall of the housing 1. An annular liquid collection box 17 is provided on the outer wall of the housing 1, and the liquid collection tank 16 is connected to the liquid collection box 17. The bottom wall height of the liquid collection tank 16 gradually decreases towards the liquid collection box 17, forming a natural guide slope, allowing liquid impurities to flow along the inclined bottom wall into the liquid collection box 17 for centralized collection. The spiral guide vane 15 creates a swirling flow, separating liquid impurities in the BOG feed gas and preventing the formation of a liquid film on the surface of the filter screen 402 or filter element 14, thereby ensuring the filtration performance of the filter screen 402 and filter element 14.

[0044] A guide weir plate 18 is provided at the top of the liquid collection tank 16. The height of the guide weir plate 18 gradually decreases towards the inner wall of the shell 1, forming an inclined slope. When liquid impurities are thrown to the inner wall of the shell 1 and flow downward under the action of centrifugal force, the inclined slope of the guide weir plate 18 can guide the liquid impurities into the liquid collection tank 16 through the slit.

[0045] The narrow size of the slit and the blocking effect of the guide weir 18 make it difficult for gas to enter the liquid collection tank 16 through the slit. In this way, liquid impurities can flow into the liquid collection tank 16 through the slit, while the gas is effectively blocked outside, achieving gas-liquid isolation and preventing liquid impurities from being carried back into the mainstream gas.

[0046] On the other hand, see Figure 8 The present invention also provides a negative pressure membrane separation helium extraction process, comprising the following steps: S1 Pretreatment: The raw gas is compressed by the compressor and filtered by the above-mentioned filtration unit before entering the mixing tank for buffering. S2 primary separation: Gas enters the primary permeation membrane, non-permeable gas is discharged directly, and permeable gas enters the negative pressure storage tank; S3 Secondary Separation: The permeate gas in the negative pressure storage tank is pressurized by the Roots blower and enters the buffer tank. Then it is compressed a second time by the compressor and enters the secondary permeate membrane. Before the non-permeate gas returns to the primary permeate membrane, the permeate gas is buffered and pressurized again. At this time, the helium content is increased to more than 80%. S4 Dehydrogenation and Dehydration: Hydrogen and oxygen in the permeate obtained in step S3 are reacted with water through a catalytic reaction, thereby removing hydrogen from the permeate. In the catalytic reaction, the reaction rate and oxygen supply should be controlled to ensure that the excess oxygen is as small as possible while ensuring the reaction. Then, the water in the permeate is removed by adsorption and desorption to ensure that the dew point meets the standard, and then proceed to the next process. S5 purification: Impurity gases are adsorbed into the adsorbent using pressure swing adsorption. Then, by depressurization and release, the purge gas is returned to the front of the secondary permeate membrane. The resulting final product gas enters the storage tank. At this point, the helium concentration is 99.999%, meeting the requirements for commercial helium.

[0047] In step S3, the volume of the negative pressure storage tank is the inlet volume of the raw gas for 0.06~0.13 min, preferably 0.1 min; the negative pressure on the suction side of the Roots blower is maintained at -0.012~-0.035 MPa, preferably -0.02 MPa. Through the above process, helium is rapidly stripped from the permeate side, improving the efficiency of membrane permeation and overcoming the current shortcomings of insufficient membrane separation efficiency.

[0048] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. 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 technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of protection of the claims of the present invention.

Claims

1. A negative pressure membrane separation helium extraction device, characterized in that, The filter unit includes a housing (1), a base (2), a rotating frame (3), a filter cartridge (4), and an elastic element (5). The housing (1) has an air inlet (101) and an air outlet (102). The base (2) is located at the bottom of the housing (1). The rotating frame (3) is rotatably mounted on the base (2). The filter cartridge (4) is axially slidably mounted on the rotating frame (3) and can move up and down relative to the rotating frame (3). The elastic element (5) is located between the filter cartridge (4) and the rotating frame (3). The filter cartridge (4) is provided with a vibration protrusion (6), and the base (2) is provided with an actuator (7). The filter cartridge (4) can rotate under the drive of the rotating frame (3) and drive the vibration protrusion (6) to intermittently strike the actuator (7) so that it generates lifting vibration under the action of the elastic member (5) to avoid impurities in the raw material gas from adhering and clogging the filter pores.

2. The negative pressure membrane separation helium extraction device according to claim 1, characterized in that, The filter cartridge (4) includes a support frame (401) and a filter screen (402). The vibration protrusion (6) is located at the lower part of the support frame (401). Both the support frame (401) and the filter cartridge (4) are cylindrical. The filter cartridge (4) is fixedly sleeved on the outer periphery of the support frame (401). The support frame (401) is provided with a downwardly extending guide rod (8). There are multiple guide rods (8) and they are spaced apart along the circumference. The guide rod (8) passes through the rotating frame (3) and slides with the rotating frame (3). The elastic element (5) is a spring and is sleeved on the guide rod (8). The two ends of the spring act on the support frame (401) and the rotating frame (3) respectively.

3. The negative pressure membrane separation helium extraction device according to claim 2, characterized in that, The rotating frame (3) is provided with a gear ring (9) on its outer periphery, and a gear (10) is rotatably provided inside the housing (1). The gear (10) meshes with the gear ring (9) and is used to connect with an external motor to drive the rotating frame (3) to rotate.

4. The negative pressure membrane separation helium extraction device according to claim 3, characterized in that, The housing (1) has an upwardly extending support rod (11) at the bottom. The support rod (11) has bristles (12) that contact the surface of the filter screen (402). The bristles (12) can provide circumferential cleaning force when the filter screen (402) rotates and axial cleaning force when the filter screen (402) vibrates up and down.

5. The negative pressure membrane separation helium extraction device according to claim 2, characterized in that, The air outlet (102) is located at the bottom of the housing (1). The bottom of the base (2) has a mounting hole (201) communicating with the air outlet (102). A mounting ring (13) is detachably provided in the mounting hole (201). A filter element (14) extending downward into the mounting ring (13) is provided in the filter screen (402) so that the raw material gas passes through the filter screen (402) and the filter element (14) in sequence before being discharged from the air outlet (102).

6. The negative pressure membrane separation helium extraction device according to claim 4, characterized in that, The housing (1) includes a main body (103) and a base plate (104). The base plate (104) is detachably disposed at the bottom of the main body (103). The base (2), the gear (10) and the support rod (11) are all disposed on the base plate (104).

7. The negative pressure membrane separation helium extraction device according to claim 1, characterized in that, The air inlet (101) is arranged tangentially along the housing (1). The inner wall of the housing (1) is provided with a plurality of circumferentially spaced spiral guide vanes (15). The spiral guide vanes (15) are used to guide the raw material gas and form a swirling flow so that the liquid impurities in the raw material gas are thrown out under centrifugal force. The inner wall of the housing (1) is provided with an annular liquid collection tank (16). The liquid collection tank (16) is located below the spiral guide vanes (15) and is used to receive the thrown-out liquid impurities.

8. The negative pressure membrane separation helium extraction device according to claim 7, characterized in that, The outer wall of the shell (1) is provided with an annular liquid collection box (17), the liquid collection tank (16) is connected to the liquid collection box (17), and the bottom wall height of the liquid collection tank (16) gradually decreases towards the liquid collection box (17).

9. A negative pressure membrane separation helium extraction device according to claim 8, characterized in that, The liquid collection tank (16) has a guide weir plate (18) at the top. The height of the guide weir plate (18) gradually decreases towards the inner wall of the shell (1). There is a slit between the end of the guide weir plate (18) and the inner wall of the shell (1) for the liquid impurities to be thrown out to pass through.

10. A negative pressure membrane separation helium extraction process, using the negative pressure membrane separation helium extraction equipment according to any one of claims 1-9, characterized in that, Includes the following steps: S1 Pretreatment: The raw gas is compressed by the compressor and filtered by the filter unit before entering the mixing tank for buffering; S2 primary separation: Gas enters the primary permeation membrane, non-permeable gas is discharged directly, and permeable gas enters the negative pressure storage tank; S3 Two-stage separation: The permeate gas in the negative pressure storage tank is pressurized by the Roots blower and enters the buffer tank. Then it is compressed a second time by the compressor and enters the second-stage permeate membrane. Before the non-permeate gas returns to the first-stage permeate membrane, the permeate gas is buffered and pressurized again. S4 dehydrogenation and dehydration: Hydrogen is removed through a catalytic reaction, and then water is removed through adsorption and desorption. S5 purification: Impurity gases are adsorbed by pressure swing adsorption, and the purge gas is returned to the front of the secondary permeate membrane to obtain the final product gas.

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