A nitrogen removal system for nitrogen-containing natural gas

Abstract

This invention discloses a nitrogen removal system for nitrogen-containing natural gas, relating to the field of natural gas processing technology. The system includes a pre-cooling box, a cryogenic box, a denitrification tower, a reboiler, a tower top condenser, a first J-T valve, a second J-T valve, a third J-T valve, valves, a gas-liquid separator, and multiple connecting pipelines. This invention also discloses a novel gas-liquid separator, which includes a tank with a docking mechanism at its top. The docking mechanism contains a support mechanism and an intermittent mechanism. The intermittent mechanism drives the support mechanism. The docking mechanism contains a lifting mechanism and a cover-opening mechanism. The intermittent mechanism drives the lifting mechanism, and the lifting mechanism drives the cover-opening mechanism. The nitrogen removal system of this invention improves the yield of natural gas and the reuse rate of cooling capacity. The gas-liquid separator of this invention is convenient to operate and maintain, and has high safety.

Description

Technical Field

[0001] This invention relates to the field of natural gas processing technology, specifically to a nitrogen removal system for nitrogen-containing natural gas. Background Technology

[0002] Natural gas, with its advantages of high quality, high efficiency, and cleanliness, is gradually entering its peak period in the overall energy structure, and its development and utilization are the main trend in global energy development today. In recent years, driven by the large demand for natural gas, a shale gas extraction boom has emerged globally, achieving significant results. However, much shale gas is high in nitrogen. Since nitrogen is an inert gas and does not support combustion, a high nitrogen content in natural gas not only reduces its calorific value and increases energy consumption during gathering and transportation, but also prevents its direct use as a feedstock for certain natural gas vehicles and fuel chemicals. In liquefied natural gas (LNG) plants, high nitrogen content in LNG increases liquefaction energy consumption and increases evaporation gas in LNG storage tanks.

[0003] Current technologies primarily utilize a dual-tower system for nitrogen removal from nitrogen-containing natural gas. The feed gas is cooled to -124°C and then enters a high-pressure tower for initial separation; this tower includes a rectification section operating at 2.4 MPa. A stream of gas is drawn from the top of the high-pressure tower and further cooled to -168°C in a condenser / reboiler before returning to the high-pressure tower for gas-liquid separation. The separated gaseous phase is crude nitrogen with a purity of approximately 50%, with a recovery rate of about 90%. The low-pressure tower operates at 0.24 MPa, with a top temperature of approximately -187°C and a bottom temperature of approximately -157°C. After rectification in the low-pressure tower, the nitrogen volume fraction in the liquefied natural gas (LNG) is reduced to below 3%. However, existing methods, when processing natural gas with low nitrogen content, result in the removal of nitrogen containing significant amounts of hydrocarbons such as methane, leading to reduced natural gas yield and low reuse rates of the cooling capacity. Summary of the Invention

[0004] To address the aforementioned problems, one objective of this invention is to provide a nitrogen removal system for nitrogen-containing natural gas. This system utilizes a dual-cold-box, single-density denitrification tower for natural gas denitrification. To achieve this objective, the nitrogen removal system of this invention includes: a pre-cold-box, a cryogenic-cold-box, a denitrification tower, a reboiler, a tower top condenser, and a gas-liquid separator. The feed gas outlet of the pre-cold-box is connected to the heat source inlet of the reboiler via a first pipe; the heat source outlet of the reboiler is connected to the feed gas inlets of the cryogenic-cold-box and the denitrification tower via a second and a third pipe, respectively; the liquid phase outlet of the denitrification tower is connected to the reboiler via a fourth pipe; the gas phase outlet of the reboiler is connected to the denitrification tower via a fifth pipe, and the liquid phase outlet of the reboiler is connected to the cryogenic-cold-box via a sixth pipe; the gas phase outlet of the denitrification tower is connected to the gas phase inlet of the tower top condenser and the liquid phase outlet of the tower top condenser via a seventh and an eighth pipe, respectively; the gas phase outlet of the tower top condenser is connected to the gas phase inlet of the tower top condenser via a seventh pipe and the liquid phase outlet of the tower top condenser via ... a seventh pipe and the liquid phase outlet of the tower top condenser via a seventh pipe and the liquid phase outlet The vapor phase outlet of the condenser is connected to the cryogenic box via the ninth pipe; the cryogenic box is connected to the precooling box via the tenth pipe; the vapor phase refrigerant outlet of the precooling box is connected to the cryogenic box via the eleventh pipe; the cryogenic box is connected to the gas-liquid separator inlet via the twelfth pipe; the vapor phase outlet of the gas-liquid separator is connected to the cryogenic box via the thirteenth pipe; the cryogenic box is connected to the precooling box via the fourteenth pipe; the liquid phase outlet of the gas-liquid separator is connected to the refrigerant inlet of the top condenser via the fifteenth pipe; the refrigerant outlet of the top condenser is connected to the cryogenic box via the sixteenth pipe; the cryogenic box is connected to the fourteenth pipe via the seventeenth pipe; the liquid phase outlet of the precooling box is connected to the fourteenth pipe via the eighteenth pipe; the precooling box is connected to a feed pipe, a liquid phase refrigerant input pipe (twenty-third pipe), a vapor phase refrigerant input pipe (twenty-first pipe), and a refrigerant output pipe (twenty-second pipe).

[0005] Furthermore, a first JT valve is provided on the nineteenth pipe, a second JT valve is provided on the twelfth pipe, and a third JT valve is provided on the fourteenth pipe.

[0006] Another object of the present invention is to provide a gas-liquid separator, which includes a tank body, a docking mechanism at the top of the tank body, a support mechanism and an intermittent mechanism inside the docking mechanism, the intermittent mechanism driving the support mechanism to operate, and a lifting mechanism and a cover opening mechanism inside the docking mechanism, the intermittent mechanism driving the lifting mechanism and the lifting mechanism driving the cover opening mechanism.

[0007] Furthermore, the tank body has a lower manhole and a middle manhole on its side wall. The middle manhole is at a higher horizontal level than the lower manhole. The bottom of the tank body is connected to a liquid outlet, and a base is welded to the bottom of the tank body. A feed inlet is provided on one side of the tank body. A level gauge is provided at the bottom of the middle manhole and is connected to the tank body. A top cover inspection port is connected to the top of the tank body, and an air outlet is connected to the top cover inspection port. An umbrella-shaped separator is installed inside the tank body, and a baffle is welded inside the tank body, with the baffle near the end of the feed inlet.

[0008] Furthermore, the docking mechanism includes a housing, which is installed between the tank and the top cover inspection port. The housing is equipped with multiple wire mesh demisters inside. An extension sleeve is fixedly connected to the top and bottom of the housing, and the extension sleeve is used to connect the tank and the top cover inspection port. The extension sleeve has multiple limiting grooves. A telescopic sleeve is slidably connected inside the extension sleeve. The telescopic sleeve has multiple protrusions, and the number of protrusions is equal to the number of limiting grooves. The protrusions are slidably connected to the extension sleeve through the limiting grooves. A limiting ring is provided on the outer side of the telescopic sleeve.

[0009] Furthermore, one of the wire mesh demisters is located between two telescopic sleeves, with one end of the two telescopic sleeves being chamfered. The telescopic sleeves are used to connect the wire mesh demister and the extension sleeve. A connecting rod is rotatably connected to the telescopic sleeve, and a deflector is rotatably connected between the two connecting rods. A first explosion-proof motor is installed inside the housing, and the first explosion-proof motor drives the deflector to rotate.

[0010] Furthermore, the support mechanism includes a support rod, a fixed shaft is fixedly connected inside the housing, a bushing is rotatably connected to the fixed shaft, a cross-shaped support rod is fixedly connected to the bushing, a ring-shaped mounting sleeve is fixedly connected to the end of the support rod, a plurality of L-shaped mounting pieces are connected to the bottom end of the mounting sleeve, and a plurality of docking grooves are provided on the wire mesh demister, the mounting pieces are used to place the wire mesh demister inside the mounting sleeve through the docking grooves.

[0011] Furthermore, the intermittent mechanism includes a gearbox, which is installed inside the housing. The input end of the gearbox is connected to a second explosion-proof motor, and the output end of the gearbox is connected to a first rotating shaft. The bottom end of the bushing is connected to a bowl-shaped grooved wheel, and one end of the first rotating shaft is fixedly connected to a driving component. The driving component and the grooved wheel cooperate with each other.

[0012] Furthermore, the lifting mechanism includes a cam. A cam is fixedly connected to the first rotating shaft. A second rotating shaft and a third rotating shaft are rotatably connected inside the housing. A first connecting rod is fixedly connected to one end of the second rotating shaft, and a second connecting rod is fixedly connected to the other end. The cam and the first connecting rod cooperate with each other. A fourth connecting rod is fixedly connected to one end of the third rotating shaft, and a first deflecting rod is fixedly connected to the other end. A third connecting rod is fixedly connected between the second connecting rod and the fourth connecting rod. A lifting plate is provided at the bottom of one of the wire mesh demisters. Two sliding rods are fixedly connected to the bottom of the lifting plate. The sliding rods are slidably connected inside the housing. A slide rail is fixedly connected to the bottom of the lifting plate. A second deflecting rod is connected to the bottom of the slide rail. The other end of the second deflecting rod is rotatably connected to the housing. A connecting piece is rotatably connected between the second deflecting rod and the first deflecting rod.

[0013] Furthermore, the opening mechanism includes an extension plate, one end of the lifting plate is fixedly connected to the extension plate, a linkage rod is slidably connected to the extension plate, a limit sleeve is fixedly connected to the linkage rod, and a sealing cover is fixedly connected to the top of the linkage rod. The sealing cover is located at the top of one of the wire mesh demisters, and the diameter of the sealing cover is larger than the outer diameter of the wire mesh demister.

[0014] The beneficial effects of this invention are:

[0015] (1) The nitrogen removal system of the present invention improves the yield of natural gas and the reuse rate of cooling capacity;

[0016] (2) The gas-liquid separation device of the present invention uses an intermittent mechanism to drive the support mechanism, and the support mechanism accurately moves the wire mesh demister to a predetermined position, quickly and automatically replacing the wire mesh demister, avoiding delays in equipment operation, with high replacement efficiency and improved maintenance efficiency.

[0017] (3) The gas-liquid separation device of the present invention connects the new wire mesh demister to the tank body and the inspection port of the top cover by setting a docking mechanism, which helps the wire mesh demister to dock quickly and plays a good sealing role, avoiding safety problems caused by natural gas flowing into the outside world, and improving the safety of use. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, 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 the structures shown in these drawings without creative effort.

[0019] Figure 1This is a schematic diagram of the nitrogen removal system provided in an embodiment of the present invention;

[0020] Figure 2 A simplified three-dimensional structural diagram of the gas-liquid separator provided in an embodiment of the present invention;

[0021] Figure 3 for Figure 2 The tank section view shown;

[0022] Figure 4 for Figure 3 The diagram shows the structural design of the box.

[0023] Figure 5 for Figure 4 The cross-sectional view of the box shown;

[0024] Figure 6 for Figure 5 The diagram shows the structure of the docking mechanism.

[0025] Figure 7 for Figure 6 The diagram shows the structural schematic of the support mechanism.

[0026] Figure 8 for Figure 7 A schematic diagram showing the connection structure of the intermittent mechanism, the material lifting mechanism, and the cover opening mechanism;

[0027] Figure 9 for Figure 8 A schematic diagram of another location is shown.

[0028] Reference numerals: 100. Pre-cooling box; 101. Cryogenic box; 102. Denitrification tower; 103. Reboiler; 104. Top condenser; 105. First JT valve; 106. Second JT valve; 107. Third JT valve; 108. Valve; 109. Gas-liquid separator; 110. First pipeline; 111. Second pipeline; 112. Third pipeline; 113. Fourth pipeline; 114. Fifth pipeline; 115. Sixth pipeline; 116. Seventh pipeline; 117. Pipeline 8; Pipelines 118, 9; Pipelines 119, 10; Pipelines 120, 11; Pipelines 121, 12; Pipelines 122, 13; Pipelines 123, 14; Pipelines 124, 15; Pipelines 125, 16; Pipelines 126, 17; Pipelines 127, 18; Feed Pipeline 128; Feed Pipeline 129; Pipelines 19; Pipelines 130; Pipelines 20; Pipelines 131; Pipelines 21; Pipelines 22; Pipelines 23;

[0029] 1. Tank body; 11. Lower manhole; 12. Middle manhole; 13. Base; 14. Inlet; 15. Outlet; 16. Level gauge; 17. Vent; 18. Top cover inspection port; 19. Umbrella plate separator; 191. Baffle; 2. Docking mechanism; 21. Box body; 22. Extension sleeve; 23. Limiting groove; 24. Telescopic sleeve; 25. Limiting ring; 26. Protrusion; 27. Wire mesh demister; 28. Connecting rod; 29. ​​Deflecting component; 291. First explosion-proof motor; 3. Support mechanism; 31. Support rod; 32. Mounting sleeve; 33. Mounting component; 34. Docking groove; 35. 36. Fixed shaft; 4. Bushing; 5. Intermittent mechanism; 6. Gearbox; 7. Second explosion-proof motor; 8. First rotating shaft; 9. Drive component; 10. Grooved wheel; 11. Lifting mechanism; 12. Cam; 13. Second rotating shaft; 14. First connecting rod; 15. Second connecting rod; 16. Third connecting rod; 17. Fourth connecting rod; 18. Third rotating shaft; 19. First deflecting rod; 20. Second deflecting rod; 10. Connecting component; 11. Lifting plate; 12. Slide rail; 13. Slide rod; 14. Cover opening mechanism; 15. Extension plate; 16. Linkage rod; 17. Sealing cover; 18. Limiting sleeve.

[0030] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0033] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. The meaning of "and / at" throughout the text is to include three parallel solutions; taking "A and / or B as an example," it includes solution A, or solution B, or a solution that simultaneously satisfies A and B. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0035] This invention proposes a nitrogen removal system for nitrogen-containing natural gas. Please refer to [link / reference]. Figure 1 As shown, it includes:

[0036] Pre-cooling box 100, deep-cooling box 101, denitrification tower 102, reboiler 103, tower top condenser 104, first JT valve 105, second JT valve 106, third JT valve 107, valve 108, gas-liquid separator 109.

[0037] In this embodiment, the raw material gas outlet of the pre-cooling box 100 is connected to the heat source inlet of the reboiler 103 via a first pipe 110; the heat source outlet of the reboiler 103 is connected to the raw material gas inlets of the cryogenic box 101 and the denitrification tower 102 via a second pipe 111 and a third pipe 112, respectively; the liquid phase outlet of the denitrification tower 102 is connected to the reboiler 103 via a fourth pipe 113; the gas phase outlet of the reboiler 103 is connected to the denitrification tower 102 via a fifth pipe 114; and the liquid phase outlet of the reboiler 103 is connected to the cryogenic box 101 via a sixth pipe 115. The gas phase outlet of the denitrification tower 102 is connected to the gas phase inlet and the liquid phase outlet of the top condenser 104 via the seventh pipe 116 and the eighth pipe 117, respectively; the gas phase outlet of the top condenser 104 is connected to the cryogenic cold box 101 via the ninth pipe 118; the cryogenic cold box 101 is connected to the pre-cooling cold box 100 via the tenth pipe 119; the gas phase refrigerant outlet of the pre-cooling cold box 100 is connected to the cryogenic cold box 101 via the eleventh pipe 120; the cryogenic cold box 101 is connected to the inlet of the gas-liquid separator 109 via the twelfth pipe 121, and the second JT valve 106 is installed on the twelfth pipe 121; gas-liquid separation... The gas phase outlet of the gas-liquid separator 109 is connected to the cryogenic cold box 101 via the thirteenth pipe 122; the cryogenic cold box 101 is connected to the pre-cooling cold box 100 via the fourteenth pipe 123; the liquid phase outlet of the gas-liquid separator 109 is connected to the refrigerant inlet of the top condenser 104 via the fifteenth pipe 124; the refrigerant outlet of the top condenser 104 is connected to the cryogenic cold box 101 via the sixteenth pipe 125; the cryogenic cold box 101 is connected to the fourteenth pipe 123 via the seventeenth pipe 126; the liquid phase outlet of the pre-cooling cold box 100 is connected to the fourteenth pipe 123 via the eighteenth pipe 127, and the third JT valve 107 is installed on the fourteenth pipe 123.

[0038] Nitrogen-containing feed gas enters the pre-cooling box 100 through feed pipe 128. After cooling, it serves as a heat source and enters the reboiler 103 through the first pipe 110. After heat exchange, it enters the cryogenic box 101 through the second pipe 111. After cryogenic cooling in the cryogenic box 101, it enters the denitrification tower 102 through the third pipe 112. The liquid phase in the denitrification tower 102 enters the reboiler 103 through the fourth pipe 113. The liquid phase in the reboiler 103 enters the cryogenic box 101 through the sixth pipe 115. After cooling, it goes to the next stage through the nineteenth pipe 129. The first JT valve 105 is installed in the nineteenth pipe. On pipe 129, the gas phase in reboiler 103 enters denitrification tower 102 through fifth pipe 114, where it forms convection with the raw material gas entering denitrification tower 102 through third pipe 112. The gas phase portion enters the top condenser 104 for cooling through seventh pipe 116. The liquid phase portion in top condenser 104 enters denitrification tower 102 through eighth pipe 117. The gas phase portion in top condenser 104 enters cryogenic cold box 101 through valve 108 and ninth pipe 118, then enters pre-cold cold box 100 through tenth pipe 119, and finally enters the next stage through twentieth pipe 130.

[0039] The gaseous refrigerant enters the pre-cooling box 100 through the twenty-first pipe 131, then enters the cryogenic box 101 through the eleventh pipe 120, and then enters the gas-liquid separator 109 through the second JT valve 106 and the twelfth pipe 121. The gaseous portion in the gas-liquid separator 109 returns to the cryogenic box 101 through the thirteenth pipe 122, then enters the pre-cooling box 100 through the fourteenth pipe 123, and then returns to the refrigerant system through the twenty-second pipe 132. The liquid portion in the gas-liquid separator 109 enters the top condenser 104 through the fifteenth pipe 124, undergoes heat exchange, then enters the cryogenic box 101 through the sixteenth pipe 125, and then merges into the fourteenth pipe 123 through the seventeenth pipe 126.

[0040] The liquid refrigerant enters the pre-cooling box 100 through the 23rd pipe 133, and then flows into the 14th pipe 123 after passing through the 3rd JT valve 107 and the 18th pipe 127.

[0041] In one embodiment of the present invention, please refer to Figures 2-9 As shown, the gas-liquid separator 109 includes a tank body 1. The top of the tank body 1 is provided with a docking mechanism 2. The docking mechanism 2 is provided with a support mechanism 3 and an intermittent mechanism 4. The intermittent mechanism 4 drives the support mechanism 3 to operate. The docking mechanism 2 is provided with a lifting mechanism 5 and a cover opening mechanism 6. The intermittent mechanism 4 drives the lifting mechanism 5, and the lifting mechanism 5 drives the cover opening mechanism 6.

[0042] The tank body 1 has a lower manhole 11 and a middle manhole 12 on its side wall. The middle manhole 12 is at a higher horizontal level than the lower manhole 11. A liquid outlet 15 is connected to the bottom of the tank body 1, and a base 13 is welded to the bottom of the tank body 1. A feed inlet 14 is located on one side of the tank body 1. A level gauge 16 is located at the bottom of the middle manhole 12 and is connected to the tank body 1. A top cover inspection port 18 is connected to the top of the tank body 1, and a gas outlet 17 is connected to the top cover inspection port 18. An umbrella-shaped separator 19 is installed inside the tank body 1, and a baffle 191 is welded inside the tank body 1, with the baffle 191 located near the end of the feed inlet 14. During the separation of crude natural gas, firstly... The conveying pipe and the feed inlet 14 are connected together. The baffle 191 acts as a guide, allowing the mixture to directly contact the umbrella plate separator 19 at the bottom. The umbrella plate separator 19 is existing technology and mainly plays the role of initial gas-liquid separation. The liquid is concentrated at the top of the tank 1 through the umbrella plate separator 19 and then discharged through the liquid outlet 15. The gas continues to pass through another umbrella plate separator 19 for further separation. Finally, it passes through the pre-set wire mesh demister 27, which is existing technology, to further separate the moisture in the gas. The separated natural gas is then concentrated inside the top cover inspection port 18 and discharged uniformly through the gas outlet 17.

[0043] In this embodiment, the docking mechanism 2 includes a housing 21. The housing 21 is installed between the tank 1 and the top cover inspection port 18. Multiple wire mesh demisters 27 are installed inside the housing 21. An extension sleeve 22 is fixedly connected to the top and bottom of the housing 21, respectively. The extension sleeve 22 connects the tank 1 and the top cover inspection port 18. Multiple limiting grooves 23 are provided on the extension sleeve 22. A telescopic sleeve 24 is slidably connected inside the extension sleeve 22. Multiple protrusions 26 are provided on the telescopic sleeve 24. The number of protrusions 26 is equal to the number of limiting grooves 23. 26 is slidably connected to the extension sleeve 22 via the limiting groove 23. The telescopic sleeve 24 is provided with a limiting ring 25 on its outer side. One wire mesh demister 27 is located between the two telescopic sleeves 24. The opposite ends of the two telescopic sleeves 24 are chamfered. The telescopic sleeves 24 are used to connect the wire mesh demister 27 and the extension sleeve 22. A connecting rod 28 is rotatably connected to the telescopic sleeve 24. A deflector 29 is rotatably connected between the two connecting rods 28. The first explosion-proof motor 291 is installed inside the housing 21. The first explosion-proof motor 291 drives the deflector. 29 rotates; when the amount of mist trapped in the jacket of the wire mesh demister 27 is very high, the liquid layer in the mesh will not condense, thus reducing or worsening the separation effect. Furthermore, the wire mesh demister 27 is in a warm and humid state, an environment most conducive to the proliferation of microorganisms and bacteria, leading to re-contamination, especially during periods of non-use. Therefore, the wire mesh demister 27 needs to be replaced and cleaned regularly. During replacement, the feeding is first stopped, and the first explosion-proof motor 291 is started to drive the deflector 29 to rotate. The telescopic sleeve 24 is connected to the deflector 29 via the connecting rod 28. 29 Rotate the connection. When the deflector 29 and the two connecting rods 28 rotate to form a straight line, the two telescopic sleeves 24 no longer contact the wire mesh demister 27. The telescopic sleeves 24 slide into the interior of the corresponding extension sleeves 22. The tank body 1 and the top cover inspection port 18 are disconnected from the wire mesh demister 27. Then, the new wire mesh demister 27 can be moved to this position. The first explosion-proof motor 291 rotates in the opposite direction. The telescopic sleeves 24 contact the end of the wire mesh demister 27, reconnect and seal, completing the replacement and sealing.

[0044] In this embodiment, the support mechanism 3 includes a support rod 31. A fixed shaft 35 is fixedly connected inside the housing 21. A bushing 36 is rotatably connected to the fixed shaft 35. A cross-shaped support rod 31 is fixedly connected to the bushing 36. A ring-shaped mounting sleeve 32 is fixedly connected to the end of the support rod 31. A plurality of L-shaped mounting pieces 33 are connected to the bottom end of the mounting sleeve 32. A plurality of docking grooves 34 are provided on the wire mesh demister 27. The mounting pieces 33 place the wire mesh demister 27 in the mounting sleeve 32 through the docking grooves 34. The support rod 31 is rotatably connected inside the housing 21. The mounting sleeve 32 is connected to the end of the support rod 31. A plurality of L-shaped mounting pieces 33 are provided at the bottom end of the mounting sleeve 32. The mounting pieces 33 place the wire mesh demister 27 through the docking grooves 34. The mounting pieces 33 are inserted into the interior of the docking grooves 34 to avoid obstructing the movement of the telescopic sleeve 24. The wire mesh demister 27 is replaced after the support rod 31 rotates.

[0045] In this embodiment, the intermittent mechanism 4 includes a reduction gearbox 41, which is installed inside the housing 21. The input end of the reduction gearbox 41 is connected to a second explosion-proof motor 42, and the output end of the reduction gearbox 41 is connected to a first rotating shaft 43. The bottom end of the bushing 36 is connected to a bowl-shaped grooved wheel 45. One end of the first rotating shaft 43 is fixedly connected to a driving component 44, and the driving component 44 and the grooved wheel 45 cooperate with each other. When the drive support rod 31 rotates, the second explosion-proof motor 42 is started. The second explosion-proof motor 42 drives the first rotating shaft 43 to rotate through the reduction gearbox 41. The first rotating shaft 43 meshes with the grooved wheel 45 through the driving component 44, driving the grooved wheel 45 to rotate 90° each time, thereby deflecting the corresponding wire mesh demister 27 to the corresponding position, reaching the designated position more accurately.

[0046] In this embodiment, the lifting mechanism 5 includes a cam 51. The cam 51 is fixedly connected to the first rotating shaft 43. A second rotating shaft 52 and a third rotating shaft 57 are rotatably connected inside the housing 21. One end of the second rotating shaft 52 is fixedly connected to a first connecting rod 53, and the other end is fixedly connected to a second connecting rod 54. The cam 51 and the first connecting rod 53 cooperate with each other. One end of the third rotating shaft 57 is fixedly connected to a fourth connecting rod 56, and the other end is fixedly connected to a first deflecting rod 58. A third connecting rod 55 is fixedly connected between the second connecting rod 54 and the fourth connecting rod 56. A lifting plate 592 is provided at the bottom of one of the wire mesh demisters 27. Two sliding rods 594 are fixedly connected to the bottom of the lifting plate 592. The sliding rods 594 are slidably connected inside the housing 21. A slide rail 593 is fixedly connected to the bottom end, and a second deflecting rod 59 is connected to the bottom end of the slide rail 593. The other end of the second deflecting rod 59 is rotatably connected to the housing 21. A connecting piece 591 is rotatably connected between the second deflecting rod 59 and the first deflecting rod 58. After the first rotating shaft 43 rotates, it drives the cam 51 to rotate. The cam 51 abuts against the first connecting rod 53 at the bottom end. Then, through the deflection action of the second rotating shaft 52 and the third rotating shaft 57, the first deflecting rod 58 rotates and pushes the second deflecting rod 59 to deflect through the connecting piece 591. When the end of the second deflecting rod 59 slides in the slide rail 593, it pushes the lifting plate 592 to move to the top, thereby lifting the used wire mesh demister 27 to the outside of the housing 21, which serves to actively remind replacement and facilitate retrieval.

[0047] In this embodiment, the opening mechanism 6 includes an extension plate 61. One end of the lifting plate 592 is fixedly connected to the extension plate 61. A linkage rod 62 is slidably connected to the extension plate 61. A limit sleeve 64 is fixedly connected to the linkage rod 62. A sealing cover 63 is fixedly connected to the top of the linkage rod 62. The sealing cover 63 is located at the top of one of the wire mesh demisters 27. The diameter of the sealing cover 63 is larger than the outer diameter of the wire mesh demister 27. When the lifting plate 592 moves, it carries the extension plate 61 to move along with it. The extension plate 61 drives the linkage rod 62 to slide upward through the limit sleeve 64. The sealing cover 63 is then lifted to expose the inlet and outlet, making it easier for the wire mesh demister 27 to be transferred to the outside of the housing 21 for easy removal or placement of new ones. When the driving member 44 continues to engage the grooved wheel 45 to rotate, the second deflection rod 59 deflects to the bottom, and the wire mesh demister 27 and the sealing cover 63 move to the bottom synchronously, completing the function of placing them in advance for use.

[0048] In this embodiment, when the gas-liquid separator 109 is in use, the crude natural gas is first separated by connecting the conveying pipeline and the inlet 14. The baffle 191 acts as a guide, allowing the mixture to directly contact the bottom umbrella plate separator 19. The umbrella plate separator 19 is existing technology and mainly serves as the initial gas-liquid separator. The liquid is concentrated at the top of the tank 1 through the umbrella plate separator 19 and then discharged through the liquid outlet 15, while the gas continues to pass through another umbrella plate separator 19 for further separation. Finally, it passes through a pre-set wire mesh demister 27, which is also existing technology, for further separation of the gas. Moisture, and then the separated natural gas is concentrated inside the top cover inspection port 18 and discharged uniformly through the gas outlet 17; when the amount of mist trapped in the jacket of the wire mesh demister 27 is very high, the liquid layer in the mesh will not condense, thus reducing or worsening the separation effect. Moreover, the wire mesh demister 27 is in a warm and humid state, which is most likely to promote the reproduction of microorganisms and bacteria and re-contamination, especially during periods of non-use. Therefore, the wire mesh demister 27 needs to be replaced and cleaned regularly. When replacing it, first stop the feeding, start the first explosion-proof motor 291, drive the deflector 29 to rotate, and the telescopic sleeve 24 is connected to the deflector 29 through the connecting rod 28. When the deflector 29 and the two connecting rods 28 rotate to form a straight line, the two telescopic sleeves 24 no longer contact the wire mesh demister 27. The telescopic sleeves 24 slide into the interior of the corresponding extension sleeves 22, and the tank body 1 and the top cover inspection port 18 are disconnected from the wire mesh demister 27. Then, a new wire mesh demister 27 can be moved to this position. The first explosion-proof motor 291 rotates in the opposite direction, and the telescopic sleeves 24 contact the end of the wire mesh demister 27, reconnecting and sealing it, thus completing the replacement and sealing. Inside the box body 21, there is a rotatable connection to the support rod 31. The end of the support rod 31 is connected to the mounting sleeve 32. The bottom of component 2 is provided with multiple L-shaped mounting pieces 33. The mounting pieces 33 are used to mount the wire mesh demister 27 through the docking groove 34. The mounting pieces 33 are inserted into the interior of the docking groove 34 to avoid obstructing the movement of the telescopic sleeve 24. The wire mesh demister 27 is replaced after the support rod 31 rotates. When the support rod 31 is driven to rotate, the second explosion-proof motor 42 is started. The second explosion-proof motor 42 drives the first rotating shaft 43 to rotate through the reduction gearbox 41. The first rotating shaft 43 engages with the grooved wheel 45 through the drive piece 44. The grooved wheel 45 rotates 90° each time, thereby deflecting the corresponding wire mesh demister 27 to the corresponding position for more precise positioning.After the first rotating shaft 43 rotates, it drives the cam 51 to rotate. The cam 51 abuts against the first connecting rod 53 at the bottom. Then, through the deflection action of the second rotating shaft 52 and the third rotating shaft 57, the first deflecting rod 58 rotates and pushes the second deflecting rod 59 to deflect through the connecting piece 591. When the end of the second deflecting rod 59 slides in the slide rail 593, it pushes the lifting plate 592 to the top, thereby lifting the used wire mesh demister 27 to the outside of the housing 21, which serves to actively prompt replacement and facilitate retrieval. Function: When the lifting plate 592 moves, it carries the extension plate 61 along with it. The extension plate 61 drives the linkage rod 62 to slide upward through the limiting sleeve 64, thereby raising the sealing cover 63 to expose the inlet and outlet, facilitating the transfer of the wire mesh demister 27 to the outside of the housing 21 for easy removal or placement of new ones. As the driving component 44 continues to engage with the grooved wheel 45 and rotate, the second deflecting rod 59 deflects to the bottom, and the wire mesh demister 27 and the sealing cover 63 move synchronously to the bottom, completing the function of pre-placing for standby.

[0049] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A nitrogen removal system for nitrogen-containing natural gas, characterized in that, The system includes a pre-cooling box, a cryogenic box, a denitrification tower, a reboiler, a top condenser, and a gas-liquid separator. The feed gas outlet of the pre-cooling box is connected to the heat source inlet of the reboiler via a first pipe. The heat source outlet of the reboiler is connected to the feed gas inlets of the cryogenic box and the denitrification tower via a second and a third pipe, respectively. The liquid phase outlet of the denitrification tower is connected to the reboiler via a fourth pipe. The gas phase outlet of the reboiler is connected to the denitrification tower via a fifth pipe, and the liquid phase outlet of the reboiler is connected to the cryogenic box via a sixth pipe. The gas phase outlet of the denitrification tower is connected to the gas phase inlet of the top condenser and the liquid phase outlet of the top condenser via a seventh and an eighth pipe, respectively. The gas phase outlet of the top condenser is connected to the cryogenic box via a ninth pipe. The cryogenic box is connected to the pre-cooling box via a tenth pipe. The gas phase refrigerant outlet of the pre-cooling box is connected to the cryogenic box via a tenth pipe. The cryogenic box is connected via the eleventh pipe; the cryogenic box is connected to the gas-liquid separator inlet via the twelfth pipe; the gas phase outlet of the gas-liquid separator is connected to the cryogenic box via the thirteenth pipe; the cryogenic box is connected to the pre-cooling box via the fourteenth pipe; the liquid phase outlet of the gas-liquid separator is connected to the refrigerant inlet of the tower top condenser via the fifteenth pipe; the refrigerant outlet of the tower top condenser is connected to the cryogenic box via the sixteenth pipe; the cryogenic box is connected to the fourteenth pipe via the seventeenth pipe; the liquid phase outlet of the pre-cooling box is connected to the fourteenth pipe via the eighteenth pipe; the pre-cooling box is connected to a feed pipe, a twenty-third pipe for liquid refrigerant input, a twenty-first pipe for gas refrigerant input, and a twenty-second pipe for refrigerant output; the liquid phase in the reboiler enters the cryogenic box via the sixth pipe, is cooled, and then goes to the next stage via the nineteenth pipe. The gas-liquid separator includes: a tank body, a docking mechanism at the top of the tank body, a support mechanism and an intermittent mechanism inside the docking mechanism, the intermittent mechanism driving the support mechanism to operate, and a lifting mechanism and a cover opening mechanism inside the docking mechanism, the intermittent mechanism driving the lifting mechanism and the lifting mechanism driving the cover opening mechanism. The docking mechanism includes a housing, which is installed between the tank and the top cover inspection port. The housing is equipped with multiple wire mesh demisters. An extension sleeve is fixedly connected to the top and bottom of the housing, and the extension sleeve is used to connect the tank and the top cover inspection port. The extension sleeve has multiple limiting grooves. A telescopic sleeve is slidably connected inside the extension sleeve. The telescopic sleeve has multiple protrusions, and the number of protrusions is equal to the number of limiting grooves. The protrusions are slidably connected to the extension sleeve through the limiting grooves. A limiting ring is provided on the outer side of the telescopic sleeve. The support mechanism includes a support rod, a fixed shaft is fixedly connected inside the housing, a bushing is rotatably connected to the fixed shaft, a cross-shaped support rod is fixedly connected to the bushing, a ring-shaped mounting sleeve is fixedly connected to the end of the support rod, a plurality of L-shaped mounting pieces are connected to the bottom end of the mounting sleeve, and a plurality of docking grooves are provided on the wire mesh demister, the mounting pieces are used to place the wire mesh demister inside the mounting sleeve through the docking grooves.

2. The system according to claim 1, characterized in that, A first JT valve is installed on the nineteenth pipeline, a second JT valve is installed on the twelfth pipeline, and a third JT valve is installed on the fourteenth pipeline.

3. The system according to claim 1, characterized in that, The tank body has a lower manhole and a middle manhole on its side wall. The middle manhole is at a higher horizontal level than the lower manhole. The bottom of the tank body is connected to a liquid outlet and a base is welded to the bottom of the tank body. The tank body has a feed inlet on one side. The bottom of the middle manhole is equipped with a level gauge connected to the tank body. The top of the tank body is connected to a top cover inspection port, and a vent is connected to the top cover inspection port. An umbrella-shaped separator is installed inside the tank body. A baffle is welded inside the tank body, with the baffle near the end of the feed inlet.

4. The system according to claim 1, characterized in that, One of the wire mesh demisters is located between two telescopic sleeves, with one end of the two telescopic sleeves being chamfered. The telescopic sleeves are used to connect the wire mesh demister and the extension sleeve. A connecting rod is rotatably connected to the telescopic sleeve, and a deflector is rotatably connected between the two connecting rods. A first explosion-proof motor is installed inside the housing, and the first explosion-proof motor drives the deflector to rotate.

5. The system according to claim 1, characterized in that, The intermittent mechanism includes a gearbox, which is installed inside the housing. The input end of the gearbox is connected to a second explosion-proof motor, and the output end of the gearbox is connected to a first rotating shaft. The bottom end of the bushing is connected to a bowl-shaped grooved wheel, and one end of the first rotating shaft is fixedly connected to a driving component. The driving component and the grooved wheel cooperate with each other.

6. The system according to claim 5, characterized in that, The lifting mechanism includes a cam. A cam is fixedly connected to the first rotating shaft. A second rotating shaft and a third rotating shaft are rotatably connected inside the housing. A first connecting rod is fixedly connected to one end of the second rotating shaft, and a second connecting rod is fixedly connected to the other end. The cam and the first connecting rod cooperate with each other. A fourth connecting rod is fixedly connected to one end of the third rotating shaft, and a first deflecting rod is fixedly connected to the other end. A third connecting rod is fixedly connected between the second connecting rod and the fourth connecting rod. A lifting plate is provided at the bottom of one of the wire mesh demisters. Two sliding rods are fixedly connected to the bottom of the lifting plate. The sliding rods are slidably connected inside the housing. A slide rail is fixedly connected to the bottom of the lifting plate. A second deflecting rod is connected to the bottom of the slide rail. The other end of the second deflecting rod is rotatably connected to the housing. A connecting piece is rotatably connected between the second deflecting rod and the first deflecting rod.

7. The system according to claim 6, characterized in that, The opening mechanism includes an extension plate. One end of the lifting plate is fixedly connected to the extension plate. A linkage rod is slidably connected to the extension plate. A limit sleeve is fixedly connected to the linkage rod. A sealing cover is fixedly connected to the top of the linkage rod. The sealing cover is located at the top of one of the wire mesh demisters. The diameter of the sealing cover is larger than the outer diameter of the wire mesh demister.

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