A nitrogen-driven water-drying process for high-voltage cables

Abstract

The present invention relates to the technical field of cable water-flooding, and specifically to a high-voltage cable nitrogen water-flooding drying process, comprising: after the cable body is connected, nitrogen enters the interior of the cable body along the air guide tube, sequentially through the hard joint and the sealing cover to start the nitrogen water-flooding work, and a color-changing silica gel test paper or a cobalt chloride test paper is used to test at the lower end outlet of the cable body. The present invention adopts the method of catalyzing nitrogen water-flooding, which will not affect the overall structure of the cable, and the electrical properties and physical and mechanical properties are the same as those of the newly produced cable body. There is no need to cut the cable body to the place where there is no water, so as to avoid greater waste caused by the new production of new cables, and the design of the sealing cover greatly improves the efficiency of assembly, and the structure of the heat shrink cap is not adopted, so waste is avoided, and the sealing effect is also guaranteed to avoid nitrogen leakage.

Description

Technical Field

[0001] The invention relates to the technical field of cable water driving, and in particular to a high-voltage cable nitrogen water driving and drying process. Background Art

[0002] In recent years, my country's power transmission and transformation projects have developed rapidly, especially in my country, which has a vast territory and the largest population. With the continuous acceleration of my country's urbanization process, the power energy facilities required for people's living, work, etc. are extremely large, especially in the development of modern highly intelligent cities. The power supply includes home, electrical, office, security, information and communication, which are particularly important for the dependence on power transmission. It plays a key role in the production and life of the people. The market prospects for the development of various supporting products required by people are broad; special cable products for transmitting electric energy are the main equipment of power transmission and transformation projects. Once the cable body is dampened by water, it will gradually form water tree discharge under the action of high-voltage electromagnetic fields, destroying the main insulation layer until it breaks down and discharges. Therefore, the quality assurance of cable construction and laying is very important for the reliable operation of cables in the future; water ingress into power cables is extremely harmful, causing serious losses and safety hazards to the national economic construction; under specific environmental conditions, due to the influence of regional climate, sometimes the cable is stored for too long, and due to improper storage, water vapor will also penetrate into the cable body.

[0003] The prior art discloses a nitrogen drying device and method for drying water inlet of power cables with publication number CN116608674A. The end of the cable to be dried is sleeved on one end of the sealing sleeve and fastened and fixed; the other end of the air guide tube is tied and fixed on the heat shrinkable plugging cap; the control valve is opened; nitrogen enters the cable body; and the water inlet end of the cable is tested. The overall physical and mechanical properties of the cable after drying by the present invention will not be affected in any way, and the treated cable has the same use effect and life as the finished cable.

[0004] However, when it is in use, the cable end is connected to the cable body with a heat shrink cap and a cable tie, which not only has a low connection efficiency, but also requires the replacement of the heat shrink cap and the cable tie for each use. For shorter cables or cables with fewer immersed sections and short drying time, frequent manual replacement and loading and unloading are required, resulting in a heavy labor burden. Summary of the invention

[0005] In order to solve the problems in the background technology, the present invention proposes a high-voltage cable nitrogen-driven water drying process.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A high-voltage cable nitrogen-driven water drying process comprises the following steps:

[0008] S1. Use a high-purity nitrogen tank with a purity of 99.99%, insert the cable body into the sealing cover along the ring, and then control the two first telescopic rods to shrink quickly, so that the connecting plate pushes the main slide bar to move, thereby driving the large and small pressure rollers to move closer to the pressure block. At the same time, the ratchet gear is meshed with the rack, and the ratchet gear will drive the large and small pressure rollers to rotate, roll up the sealing cover, and make the sealing cover close to the outer wall of the cable body. In addition, the inertia generated by the rotation of the large and small pressure rollers will drive the large pressure rollers to move closer to the pressure block. The roller and the small pressure roller rotate continuously, and then the top of the sealing cover is continuously curled upward, so that the sealing cover is tightly sealed against the cable body. At the same time, the top of the sealing cover is folded toward the small pressure roller with a smaller diameter, and the connecting plate also contacts the top block, so that the top block drives the side slide bar to move upward as a whole, and the sealing cover and the cable body are supported by the lower support block. Then the second telescopic rod is extended, driving the pressure block to press down, and the bending part of the top of the sealing cover is pressed tightly, so that the sealing cover and the cable body are completely sealed, that is, the sealing operation of the cable end is completed;

[0009] S2. Open the air pressure valve, and nitrogen enters the nitrogen booster valve. The nitrogen pushes up the booster gauge pointer, and the pointer controls the air pressure to be around 15Pa. Unscrew the flow valve, and the flow meter controls the pressure to be around 1.5~2.0Pa. The nitrogen flows along the air guide pipe, through the hard joint and the sealing cover, into the cable body to start nitrogen water displacement.

[0010] S3. During the process of nitrogen filling and water dissipation, in order to check the dryness inside the cable body, a color-changing silica gel test paper or a cobalt chloride test paper is used to test at the lower end outlet of the cable body. The original test paper is blue, and the test paper is pink, which proves that there are still water vapor molecules remaining in the cable body. Nitrogen filling and drying should continue. The required amount of nitrogen is based on the dryness of the water-influent cable body. The nitrogen bottle should be replaced. If there is no change after the test paper test, it proves that there is no water vapor in the cable body. In order to ensure that the water-influent cable body is fully dried, continue to fill with nitrogen to ensure that the cable body is completely dry.

[0011] S4. After nitrogen filling, water expulsion and drying, a 15KV / 5min withstand voltage and overload test is required to verify the high reliability and safety of the cable body;

[0012] The nitrogen tank is equipped with an air pressure valve, the output end of the air pressure valve is equipped with a flow meter, the flow meter is equipped with a boost meter, the output end of the nitrogen boost valve is equipped with a flow valve, the flow valve is equipped with a flow meter, the output end of the flow valve is fixedly connected to an air duct, and the end of the air duct away from the flow valve is fixedly connected to a blocking device, characterized in that: the blocking device includes a hard joint connected to the air duct, one end of the hard joint is fixedly connected to a sealing cover, the outer wall of the hard joint is fixedly connected to a mounting cover, the outer walls on both sides of the mounting cover are fixedly connected to vertically arranged side mounting plates, a large pressure roller and a small pressure roller are arranged between the two side mounting plates, and the two The top of the side mounting plates is fixedly connected with an upper mounting plate, the middle parts of the two side mounting plates are fixedly connected with a first telescopic rod, and the two first telescopic rods are respectively used to drive the large pressure roller and the small pressure roller to move, each of the first telescopic rods is fixedly connected with a connecting plate at one end away from the side mounting plate, and each of the two connecting plates is fixedly connected with a main sliding rod at both ends, and the main sliding rod is parallel to the first telescopic rod, and each of the main sliding rods is fixedly connected with a sliding block at one end away from the connecting plate. The four sliding blocks are respectively rotatably connected to the two ends of the large pressure roller and the small pressure roller, and the middle part of the upper mounting plate is fixedly connected with a second telescopic rod, and the lower end of the second telescopic rod is fixedly connected with a pressing block.

[0013] Preferably, the large pressure roller and the small pressure roller are composed of two rollers and an axle, the two rollers are connected in series by an axle, a ratchet gear is fixedly connected to the axle, the pressure block is located at the center of the four rollers, the diameter of the roller on the large pressure roller is larger than the diameter of the roller on the small pressure roller, and both ends of the axle are fixedly connected with blocks.

[0014] Preferably, a plurality of racks are fixedly connected to the bottom of the upper mounting plate, and the bottom of the racks are meshed with the ratchet gear. When the large pressure roller approaches the pressure block under the push of the first telescopic rod, it will rotate under the transmission of the ratchet gear. When the small pressure roller approaches the pressure block under the push of the first telescopic rod, it will also rotate under the transmission of the ratchet gear.

[0015] Preferably, a plurality of sliding rods are fixedly connected between the two side mounting plates, the sliding blocks are slidably connected to the sliding rods, both ends of the sliding rods are fixedly connected to mounting strips, the mounting strips are fixedly connected to the outer walls of the side mounting plates, and the connecting plates are slidably connected to the side mounting plates and the mounting strips.

[0016] Preferably, the outer wall of each of the side mounting plates is slidably connected to two vertically arranged side slide bars, a lower support block is arranged directly below the sealing cover, and the end of the lower support block is fixedly connected to the bottom of the side slide bar.

[0017] Preferably, the upper end of the side slide bar is fixedly connected with a top block, the outer wall of the side mounting plate is provided with a vertically arranged slide groove, the outer wall of the top block is fixedly connected with a protrusion, the protrusion is slidably connected to the inner wall of the slide groove, the inside of the slide groove is fixedly connected with a spring, and one end of the spring is fixedly connected to the outer wall of the protrusion.

[0018] Preferably, a mounting frame is fixedly connected to a side of each of the side mounting plates away from the mounting cover, and a collar is fixedly connected between the two mounting frames.

[0019] Compared with the existing technology, the present invention has the following beneficial effects:

[0020] 1. The use of nitrogen-driven water-displacing method will not affect the overall structure of the cable. The electrical and physical mechanical properties are the same as those of the newly produced cable body. There is no need to cut the cable body to the place where there is no water, avoiding greater waste caused by the production of new cables;

[0021] 2. The design of sealing cover greatly improves the efficiency of assembly, and the structure without heat shrink cap is adopted to avoid waste. The sealing effect is also guaranteed to avoid nitrogen leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a three-dimensional structural schematic diagram of the present invention;

[0023] Figure 2 It is an enlarged schematic diagram of the structure of the blocking device of the present invention;

[0024] Figure 3 is a structural front view of the blocking device of the present invention;

[0025] Figure 4 is a schematic cross-sectional view of the structure of the blocking device of the present invention;

[0026] Figure 5 The present invention Figure 4 A schematic diagram of the structure enlargement at the center A;

[0027] Figure 6 The internal structure of the blocking device of the present invention is shown in FIG. Figure 1 ;

[0028] Figure 7 The internal structure of the blocking device of the present invention is shown in FIG. Figure 2 ;

[0029] Figure 8 The present invention Figure 7 A magnified schematic diagram of the structure at point B in the middle.

[0030] In the figure: 1. nitrogen tank; 2. air pressure valve; 3. boost gauge; 4. nitrogen boost valve; 5. flow meter; 6. flow valve; 7. air guide tube; 8. blocking device; 9. mounting cover; 10. sealing cover; 11. upper mounting plate; 12. side mounting plate; 13. large pressure roller; 14. small pressure roller; 15. mounting strip; 16. slide bar; 17. first telescopic rod; 18. connecting plate; 19. main slide bar; 20. rack; 21. ratchet gear; 22. slider; 23. second telescopic rod; 24. pressure block; 25. mounting frame; 26. collar; 27. side slide bar; 28. slide groove; 29. ​​top block; 30. lower support block; 31. bump; 32. spring; 33. stopper. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0033] Reference Figure 1 - Figure 8 , a high voltage cable nitrogen drive water drying process, comprising the following steps:

[0034] S1. Use a high-purity nitrogen tank 1 with a purity of 99.99%, insert the cable body into the sealing cover 10 along the ring 26, and then control the two first telescopic rods 17 to shrink quickly, so that the connecting plate 18 pushes the main slide bar 19 to move, thereby driving the large pressure roller 13 and the small pressure roller 14 to move toward the pressure block 24. At the same time, the ratchet gear 21 is meshed with the rack 20, and the ratchet gear 21 will drive the large pressure roller 13 and the small pressure roller 14 to rotate, and roll up the sealing cover 10, so that the sealing cover 10 is tightly attached to the outer wall of the cable body, and the inertia generated by the rotation of the large pressure roller 13 and the small pressure roller 14 will drive the large pressure roller 13 and the small pressure roller 14 to move closer to the pressure block 24. The pressure roller 13 and the small pressure roller 14 rotate continuously, and then the top of the sealing cover 10 is continuously curled upward, so that the sealing cover 10 is tightly sealed against the cable body. At the same time, the top of the sealing cover 10 is folded toward the small pressure roller 14 with a smaller diameter, and the connecting plate 18 also contacts the top block 29, so that the top block 29 drives the side slide bar 27 to move upward as a whole, and the sealing cover 10 and the cable body are supported by the lower support block 30. Then the second telescopic rod 23 extends, driving the pressure block 24 to press down, and the bending part of the top of the sealing cover 10 is pressed tightly, so that the sealing cover 10 and the cable body are completely sealed, that is, the sealing operation of the cable end is completed;

[0035] S2, open the air pressure valve 2, nitrogen enters the nitrogen booster valve 4, the nitrogen pushes up the pointer of the booster gauge 3, the pointer controls the air pressure to be around 15Pa, unscrew the flow valve 6, the flow meter 5 controls the pressure to be around 1.5~2.0Pa, the nitrogen goes along the air guide pipe 7, sequentially passes through the hard joint and the sealing cover 10 into the interior of the cable body to start the nitrogen water displacing work;

[0036] S3. During the process of nitrogen filling and water dissipation, in order to check the dryness inside the cable body, use one of the color-changing silica gel test paper or cobalt chloride test paper to test at the lower end outlet of the cable body. The original test paper is blue, and the test paper is pink, which proves that there are still water vapor molecules remaining in the cable body. Nitrogen filling and drying should continue. The required amount of nitrogen should be replaced according to the dryness of the water-influent cable body. When there is no change after the test paper test, it proves that there is no water vapor in the cable body. In order to ensure that the water-influent cable body is fully dried, continue to fill with nitrogen to ensure that the cable body is completely dry.

[0037] S4. After nitrogen filling, water expulsion and drying, a 15KV / 5min withstand voltage and overload test is required to verify the high reliability and safety of the cable body;

[0038] A pressure valve 2 is installed on the nitrogen tank 1, a flow meter 5 is installed on the output end of the pressure valve 2, a boost meter 3 is installed on the flow meter 5, a flow valve 6 is installed on the output end of the nitrogen boost valve 4, a flow meter 5 is installed on the flow valve 6, an air pipe 7 is fixedly connected to the output end of the flow valve 6, and a sealing device 8 is fixedly connected to the end of the air pipe 7 away from the flow valve 6. The sealing device 8 includes a hard joint connected to the air pipe 7, a sealing cover 10 is fixedly connected to one end of the hard joint, and a mounting cover 9 is fixedly connected to the outer wall of the hard joint. The outer walls on both sides of the mounting cover 9 are fixedly connected to vertically arranged side mounting plates 12, a large pressure roller 13 and a small pressure roller 14 are arranged between the two side mounting plates 12, an upper mounting plate 11 is fixedly connected to the top between the two side mounting plates 12, and the middle of the two side mounting plates 12 The upper and lower parts are fixedly connected with a first telescopic rod 17, and the two first telescopic rods 17 are respectively used to drive the large pressure roller 13 and the small pressure roller 14 to move. The end of each first telescopic rod 17 away from the side mounting plate 12 is fixedly connected to a connecting plate 18, and both ends of each connecting plate 18 are fixedly connected to a main sliding rod 19, and the main sliding rod 19 is parallel to the first telescopic rod 17. One end of each main sliding rod 19 away from the connecting plate 18 passes through the side mounting plate 12 and is fixedly connected to a slider 22. The four sliders 22 are rotatably connected to the two ends of the large pressure roller 13 and the small pressure roller 14, respectively. A second telescopic rod 23 is fixedly connected to the middle part of the upper mounting plate 11, and a pressing block 24 is fixedly connected to the lower end of the second telescopic rod 23. The first telescopic rod 17 and the main sliding rod 19 are both electrically driven and can be quickly extended or shortened after power is turned on.

[0039] Specifically, the large pressure roller 13 and the small pressure roller 14 are each composed of two rollers and an axle rod, and the two rollers are connected in series by an axle rod, a ratchet gear 21 is fixedly connected to the axle rod, and the pressure block 24 is located at the center of the four rollers. The diameter of the roller on the large pressure roller 13 is larger than the diameter of the roller on the small pressure roller 14, and both ends of the axle rod are fixedly connected to blocks 33. A plurality of racks 20 are fixedly connected to the bottom of the upper mounting plate 11, and the bottom of the racks 20 is meshed with the ratchet gear 21. When the large pressure roller 13 approaches the pressure block 24 under the push of the first telescopic rod 17, it will rotate under the transmission of the ratchet gear 21. When the small pressure roller 14 approaches the pressure block 24 under the push of the first telescopic rod 17, it will also rotate under the transmission of the ratchet gear 21. Due to the provision of the ratchet gear 21, even after the first telescopic rod 17 is extended to the maximum extent, the large pressure roller 13 and the small pressure roller 14 continue to rotate under the action of inertia, and the sealing cover 10 is continuously collected to ensure that the sealing cover 10 is tightly attached to the cable body.

[0040] Specifically, a plurality of slide bars 16 are fixedly connected between the two side mounting plates 12, the slider 22 is slidably connected to the slide bar 16, both ends of the slide bar 16 are fixedly connected to the mounting strips 15, the mounting strips 15 are fixedly connected to the outer wall of the side mounting plate 12, and the connecting plate 18 is slidably connected to the side mounting plate 12 and the mounting strips 15, wherein the mounting strips 15 are used to connect and fix a plurality of slide bars 16, and the slide bar 16 is used to limit the slide bar 22 to ensure that the slide bar 22 can slide stably along the slide bar 16 under the push of the first telescopic rod 17.

[0041] Specifically, the outer wall of each side mounting plate 12 is slidably connected to two vertically arranged side slide bars 27, and a lower support block 30 is arranged directly below the sealing cover 10. The end of the lower support block 30 is fixedly connected to the bottom of the side slide bar 27. The lower support block 30 is used to support the sealing cover 10 and the cable body to ensure that the upper end of the sealing cover 10 can be squeezed when the second telescopic rod 23 is pressed downward, so that the sealing cover 10 and the cable body are completely sealed.

[0042] Specifically, a top block 29 is fixedly connected to the upper end of the side slide bar 27, a vertically arranged slide groove 28 is opened on the outer wall of the side mounting plate 12, a protrusion 31 is fixedly connected to the outer wall of the slide groove 28, the protrusion 31 is slidably connected to the inner wall of the slide groove 28, a spring 32 is fixedly connected to the inside of the slide groove 28, one end of the spring 32 is fixedly connected to the outer wall of the protrusion 31, and the arrangement of the slide groove 28, the protrusion 31 and the spring 32 is used to limit the top block 29.

[0043] Specifically, a mounting bracket 25 is fixedly connected to one side of each side mounting plate 12 away from the mounting cover 9 , and a collar 26 is fixedly connected between the two mounting brackets 25 . The collar 26 is used to initially limit the position of the cable body to facilitate subsequent installation.

[0044] It is further explained that the above-mentioned fixed connection should be understood in a broad sense unless otherwise clearly specified and limited. For example, it can be welding, gluing, or one-piece molding, etc., which are conventional means well known to those skilled in the art.

[0045] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high voltage cable nitrogen flooding and drying process, characterized in that: The following steps are involved: S1. Use a high-purity nitrogen tank (1) with a purity of 99.99%, insert the cable body along the ring (26) into the interior of the sealing cover (10), and then control the two first telescopic rods (17) to shrink quickly, so that the connecting plate (18) pushes the main slide bar (19) to move, thereby driving the large pressure roller (13) and the small pressure roller (14) to move toward the pressure block (24). At the same time, the ratchet gear (21) and the rack (20) are meshed, and the ratchet gear (21) will drive the large pressure roller (13) and the small pressure roller (14) to rotate, and roll up the sealing cover (10), so that the sealing cover (10) is tightly attached to the outer wall of the cable body, and the inertia generated when the large pressure roller (13) and the small pressure roller (14) rotate will drive The large pressure roller (13) and the small pressure roller (14) are continuously rotated, thereby continuously curling the top of the sealing cover (10) upward, so that the sealing cover (10) is tightly sealed against the cable body. At the same time, the top of the sealing cover (10) is folded toward the small pressure roller (14) with a smaller diameter, and the connecting plate (18) also contacts the top block (29), so that the top block (29) drives the side slide bar (27) to move upward as a whole, and the sealing cover (10) and the cable body are supported by the lower support block (30). Then, the second telescopic rod (23) is extended, driving the pressure block (24) to press downward, and the bending part of the top of the sealing cover (10) is pressed tightly, so that the sealing cover (10) and the cable body are completely sealed, and the sealing operation of the cable end is completed; S2, open the air pressure valve (2), nitrogen enters the nitrogen booster valve (4), the nitrogen pushes up the pointer of the booster gauge (3), the pointer controls the air pressure to be 15Pa, screw and loosen the flow valve (6), the flow meter (5) controls the pressure to be 1.5~2.0Pa, the nitrogen flows along the air guide tube (7), sequentially through the hard joint and the sealing cover (10) into the interior of the cable body, and the nitrogen water dissipation work begins; S3. During the process of nitrogen filling and water dissipation, in order to check the dryness inside the cable body, a color-changing silica gel test paper or a cobalt chloride test paper is used to test at the lower end outlet of the cable body. The original test paper is blue, and the test paper is pink, which proves that there are still water vapor molecules remaining in the cable body. Nitrogen filling and drying should continue. The required amount of nitrogen is based on the dryness of the water-influent cable body. The nitrogen bottle should be replaced. If there is no change after the test paper test, it proves that there is no water vapor in the cable body. In order to ensure that the water-influent cable body is fully dried, continue to fill with nitrogen to ensure that the cable body is completely dry. S4. After nitrogen filling, water expulsion and drying, a 15KV / 5min withstand voltage and overload test is required to verify the high reliability and safety of the cable body; The nitrogen tank (1) is provided with an air pressure valve (2), a flow meter (5) is provided at the output end of the air pressure valve (2), a pressure meter (3) is provided on the flow meter (5), a flow valve (6) is provided at the output end of the nitrogen pressure boosting valve (4), a flow meter (5) is provided on the flow valve (6), an air guide pipe (7) is fixedly connected to the output end of the flow valve (6), an end of the air guide pipe (7) away from the flow valve (6) is fixedly connected to a blocking device (8), the blocking device (8) comprises a hard joint connected to the air guide pipe (7), one end of the hard joint is fixedly connected to a sealing cover (10), an outer wall of the hard joint is fixedly connected to a mounting cover (9), outer walls on both sides of the mounting cover (9) are fixedly connected to vertically arranged side mounting plates (12), a large pressure roller (13) and a small pressure roller (14) are provided between the two side mounting plates (12), and a top portion between the two side mounting plates (12) is provided. An upper mounting plate (11) is fixedly connected, and the middle parts of the two side mounting plates (12) are fixedly connected with a first telescopic rod (17), and the two first telescopic rods (17) are respectively used to drive the large pressure roller (13) and the small pressure roller (14) to move. One end of each of the first telescopic rods (17) away from the side mounting plate (12) is fixedly connected with a connecting plate (18), and both ends of each of the connecting plates (18) are fixedly connected with a main sliding rod (19), and the main sliding rod (19) is parallel to the first telescopic rod (17). One end of each of the main sliding rods (19) away from the connecting plate (18) passes through the side mounting plate (12) and is fixedly connected with a slider (22), and the four sliders (22) are respectively rotatably connected to the two ends of the large pressure roller (13) and the small pressure roller (14). A second telescopic rod (23) is fixedly connected with the middle part of the upper mounting plate (11), and a pressure block (24) is fixedly connected with the lower end of the second telescopic rod (23).

2. A high voltage cable nitrogen flooding and drying process according to claim 1, characterized in that: The large pressure roller (13) and the small pressure roller (14) are each composed of two rollers and a shaft, the two rollers are connected in series by a shaft, a ratchet gear (21) is fixedly connected to the shaft, the pressure block (24) is located at the center of the four rollers, the diameter of the roller on the large pressure roller (13) is larger than the diameter of the roller on the small pressure roller (14), and both ends of the shaft are fixedly connected to stoppers (33).

3. A high voltage cable nitrogen flooding and drying process according to claim 2, characterized in that: A plurality of racks (20) are fixedly connected to the bottom of the upper mounting plate (11), and the bottom of the racks (20) meshes with the ratchet gear (21). When the large pressure roller (13) approaches the pressure block (24) under the push of the first telescopic rod (17), it will rotate under the drive of the ratchet gear (21). When the small pressure roller (14) approaches the pressure block (24) under the push of the first telescopic rod (17), it will also rotate under the drive of the ratchet gear (21).

4. A high voltage cable nitrogen flooding and drying process according to claim 1, characterized in that: A plurality of slide bars (16) are fixedly connected between the two side mounting plates (12), the slide blocks (22) are slidably connected to the slide bars (16), both ends of the slide bars (16) are fixedly connected to mounting strips (15), the mounting strips (15) are fixedly connected to the outer walls of the side mounting plates (12), and the connecting plates (18) are slidably connected to the side mounting plates (12) and the mounting strips (15).

5. A high voltage cable nitrogen flooding and drying process according to claim 1, characterized in that: The outer wall of each side mounting plate (12) is slidably connected to two vertically arranged side sliding strips (27), and a lower support block (30) is arranged directly below the sealing cover (10), and the end of the lower support block (30) is fixedly connected to the bottom of the side sliding strip (27).

6. A high voltage cable nitrogen flooding and drying process according to claim 5, characterized in that: The upper end of the side slide bar (27) is fixedly connected to a top block (29); the outer wall of the side mounting plate (12) is provided with a vertically arranged slide groove (28); the outer wall of the top block (29) is fixedly connected to a protrusion (31); the protrusion (31) is slidably connected to the inner wall of the slide groove (28); the interior of the slide groove (28) is fixedly connected to a spring (32); one end of the spring (32) is fixedly connected to the outer wall of the protrusion (31).

7. A high voltage cable nitrogen flooding and drying process according to claim 1, characterized in that: A mounting frame (25) is fixedly connected to a side of each side mounting plate (12) away from the mounting cover (9), and a collar (26) is fixedly connected between two mounting frames (25).

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