Double-movable gate valve for chemical production

Abstract

The utility model relates to a double movable gate valve for chemical production, which comprises a valve body, valve covers are detachably and fixedly connected to the upper end and the lower end of the valve body, two valve seats are detachably and fixedly connected to the inner wall of the valve body, a piston cylinder extending left and right is arranged between the two valve seats, and pistons are slidably connected to the left end and the right end of the piston cylinder. Flashboards are detachably and fixedly connected to the ends, away from each other, of the two pistons, the two flashboards are opposite to the two valve seats respectively, guide blocks are fixedly connected to the ends, close to each other, of the two pistons, and guide slopes are arranged on the sides, close to each other, of the two guide blocks; a hollow valve rod is detachably and fixedly connected to the top of the piston cylinder, a hollow extrusion rod is arranged in an inner cavity of the valve rod in a penetrating mode, two extrusion slopes are arranged at the lower end of the extrusion rod, and the two extrusion slopes are matched with the guide slopes of the two guide blocks respectively. The extrusion rod is matched with an external fluid source to provide hydraulic pressure or air pressure to enable the two gate plates to move horizontally, friction between the gate plates and ports is greatly reduced, and the gate valve is more durable and higher in sealing performance.

Description

Technical Field

[0001] This utility model relates to the field of gate valve technology, specifically to a double-moving gate valve for chemical production. Background Technology

[0002] In chemical production, gate valves are commonly used in chemical gas transmission pipelines. A gate valve typically consists of a valve body and a gate. The valve body has inlet and outlet ports, and the gate is slidably connected to the valve body. The opening or closing of the inlet and outlet ports is controlled by the movement of the gate.

[0003] For example, CN106439776A discloses an adaptive once-through boiler condensate expansion control device. This device is actually based on the structure of a common gate valve, using a trapezoidal valve core (i.e., a gate) that slides up and down to seal the input and output ports on both sides, thus achieving a seal. However, because the gate of an existing gate valve uses this straight-up-and-down method, it generates significant vertical friction with the ports on both sides when opening or closing. This causes wear on the ports and the gate, resulting in a shorter valve lifespan. Excessive wear can easily lead to leakage, insufficient sealing, and affect the sealing effect. Utility Model Content

[0004] This invention addresses the shortcomings of existing technologies by providing a double-acting gate valve for chemical production. Employing a double-gate structure, the two gates move horizontally, moving away from the valve seats on either side of the sealing surface. This significantly reduces friction between the gates and valve seats, resulting in greater durability and improved sealing. Furthermore, the valve seat and valve body, as well as the valve stem, compression rod, and gates, are all designed as separate units, facilitating easy disassembly and replacement, reducing operating costs, and providing convenience.

[0005] This utility model is achieved through the following technical solution: a double movable gate valve for chemical production, comprising a valve body, with valve covers fixedly connected to the upper and lower ends of the valve body, characterized in that: two valve seats opposite to each other are provided on the inner wall of the valve body, two delivery pipes corresponding to the two valve seats are fixedly connected to the valve body, a piston cylinder is provided between the two valve seats, pistons are slidably connected to both ends of the piston cylinder, gate plates are fixedly connected to the ends of the two pistons that are far apart from each other, the two gate plates are respectively sealed to the two valve seats, a valve stem is fixedly connected to the top of the piston cylinder, and the upper end of the valve stem extends to the outside through the valve cover; it also includes a drive assembly for driving the two pistons to slide far apart from each other along the axial direction of the piston cylinder.

[0006] This solution uses a drive assembly to drive two pistons away from each other, thereby causing two gates to move horizontally and seal with their corresponding valve seats. When the valve is closed, pressure is released, and the friction between the gates and valve seats is greatly reduced, thus effectively reducing wear between the valve seats and gates and improving the service life of the valve.

[0007] As an optimization, the valve stem is hollow, and guide blocks are fixed to the ends of the two pistons that are close to each other. Guide ramps are provided on the sides of the two guide blocks that are close to each other. The drive assembly is a pressing rod that passes through the valve stem and slides up and down. The lower end of the pressing rod extends through the piston cylinder to between the two guide blocks, and the lower end of the pressing rod has two pressing ramps, which respectively cooperate with the guide ramps of the two guide blocks. This optimized solution allows the pressing rod to slide downwards along the valve stem, causing the pressing ramps at the lower end of the pressing rod to fit against the guide ramps of the two guide blocks. The pressing rod pushes the two guide blocks outwards, causing them to move away from each other. This, in turn, causes the two gates to move away from each other and press against the two valve seats, achieving a sealed connection between the gates and the valve seats, thereby sealing the delivery pipe opening.

[0008] As an optimization, an air inlet pipe is fixedly connected to the extrusion rod, extending along the length of the extrusion rod and penetrating it. The upper end of the air inlet pipe is connected to an external fluid source, and an exhaust pipe is connected to the air inlet pipe. Both the air inlet and exhaust pipes are equipped with on / off valves. In this optimized solution, the external fluid source delivers high-pressure fluid to the piston cylinder through the air inlet pipe. The high-pressure fluid further compresses the pistons on both sides, thereby further improving the sealing between the gate and the valve seat, and enhancing the valve's sealing effect.

[0009] As an optimization, an annular venting chamber is formed between the extrusion rod and the valve stem. The inlet-side delivery pipe is connected to the annular venting chamber via an air inlet pipe, and the outlet-side delivery pipe is connected to the annular venting chamber via an exhaust pipe. Switch valves are installed on both the air inlet and exhaust pipes. In this optimized design, after the extrusion rod drives the gates on both sides to seal the valve seats on both sides, the fluid in the delivery pipe enters the annular venting chamber through the air inlet pipe, and then enters the piston cylinder through the annular venting chamber to further compress and tighten the two gates. Utilizing the fluid itself further improves the sealing effect, making it more convenient to use, eliminating the need for an external fluid source, and saving on operating costs.

[0010] As an optimization, an annular groove is provided at the lower end of the valve stem, and a guide ring is embedded in the groove. The inner diameter of the guide ring is adapted to the outer diameter of the extrusion rod, and multiple venting grooves are formed circumferentially on the inner wall of the guide ring. This optimized design guides the up-and-down sliding of the extrusion rod through the guide ring, resulting in more stable sliding. The venting grooves on the guide ring facilitate the entry of gas into the piston cylinder.

[0011] As an optimization, a partition plate is fixedly connected inside the piston cylinder between the two pistons, forming an inflation chamber between the pistons and the partition plate. The drive assembly consists of two air inlet pipes fixed in the valve stem, both of which pass through the valve stem and connect to the two inflation chambers respectively. Each air inlet pipe is connected to an external fluid source, and each air inlet pipe is connected to an exhaust pipe. Switch valves are installed on both the air inlet and exhaust pipes. This optimized solution uses high-pressure gas or high-pressure liquid supplied to the inflation chambers from an external fluid source to compress and drive the pistons, thereby achieving a sealed connection between the gate and the valve seat. The partition plate divides the piston cylinder into two chambers, and the two air inlet pipes allow the two pistons to slide independently. Thus, if one piston leaks and fails, only the other piston needs to be driven to seal the valve. During maintenance, the damaged piston can be repaired, and the valve can still be used normally even if one piston is damaged, making operation more economical.

[0012] As an optimization, external sealing sleeves are fixed to both ends of the piston cylinder, and the two external sealing sleeves are respectively fitted onto the two gate plates. This optimization scheme improves the sealing performance between the piston and the piston cylinder through the sealing of the external sealing sleeves.

[0013] As an optimization, a single-walled bellows is provided between the piston cylinder and the gate. One end of the single-walled bellows is sealed and fixedly connected to the piston cylinder, and the other end of the single-walled bellows is sealed and fixedly connected to the gate. This optimization scheme can improve the sealing effect between the gate and the piston cylinder and prevent air leakage.

[0014] As an optimization, a hollow double-walled bellows is provided between the gate and the valve seat. The double-walled bellows is fixedly connected to the valve seat, and a vent pipe is fixedly connected to the valve body. One end of the vent pipe communicates with the inner cavity of the double-walled bellows, and a switch valve is installed on the vent pipe. In this optimized design, the gate and the double-walled bellows form a second sealing structure after sealing contact. High-pressure fluid is introduced into the double-walled bellows through the vent pipe, ensuring tight contact between the double-walled bellows and the gate, further improving the sealing performance.

[0015] As an optimization, a hollow rubber tube is provided between the gate and the valve seat. The rubber tube is annular and fixedly connected to the valve seat. A vent pipe is fixedly connected to the valve body, with one end of the vent pipe communicating with the inner cavity of the rubber tube. A switch valve is installed on the vent pipe. In this optimized solution, the gate and the rubber tube form a second sealing structure after sealing contact. High-pressure fluid is introduced into the rubber tube through the vent pipe, making the rubber tube and the gate in tight contact, further improving the sealing performance.

[0016] The beneficial effects of this utility model are as follows: This solution adopts a double gate structure, and the drive component can use the extrusion rod to slide up and down, so that the two gates move horizontally away from each other and seal with the valve seats on both sides, thereby opening or sealing the delivery pipe. The friction between the gate and the valve seat is greatly reduced, avoiding wear and making the valve more durable.

[0017] After the two gates are sealed and connected with the valve seat, high-pressure fluid is injected into the piston cylinder through the air inlet pipe. The high-pressure fluid fills the space between the two pistons, thereby further pressurizing the two gates and improving the sealing effect between the gates and the valve seat.

[0018] When the gate plate connects with the valve seat, it forms the first sealing structure. When the gate plate connects with the double-walled bellows or rubber tube, it forms the second sealing structure. High-pressure fluid is injected into the double-walled bellows or rubber tube through the vent pipe, so that the double-walled bellows or rubber tube fits tightly with the gate plate, further improving the sealing effect and thus ensuring the valve's sealing performance.

[0019] The piston cylinder is divided into two chambers by a partition plate. The drive assembly can use two air intake pipes to drive the two pistons to slide independently. By supplying air through the two air intake pipes, the two pistons can slide independently. In this way, if one piston leaks air and is damaged, only the other piston needs to be driven to seal the valve. During maintenance, the damaged piston can be repaired. The valve can still be used normally even if one piston is damaged, making the operation more economical and safer. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of Example 1;

[0021] Figure 2 This is a schematic diagram of the valve body structure in Example 1;

[0022] Figure 3 This is a schematic diagram of the piston cylinder structure in Example 1;

[0023] Figure 4 for Figure 3 Enlarged view of part A;

[0024] Figure 5 This is a cross-sectional view of Example 2;

[0025] Figure 6 This is a cross-sectional view of Example 3;

[0026] Figure 7 for Figure 6 Enlarged view of part B;

[0027] Figure 8 This is a cross-sectional view of Example 4;

[0028] Figure 9 This is a schematic diagram of the guide ring structure;

[0029] Figure 10 This is a cross-sectional view of Example 5;

[0030] Figure 11 for Figure 10 Enlarged view of part C;

[0031] As shown in the figure:

[0032] 1. Valve body, 2. Valve cover, 3. Valve seat, 4. Piston cylinder, 5. Piston, 6. Gate, 7. Guide block, 8. Valve stem, 9. Extrusion rod, 10. Delivery pipe, 11. Insert ring, 12. Limiting post, 13. Sealing gasket, 14. Outer sealing sleeve, 15. Third sealing ring, 16. Fourth sealing ring, 17. First sealing ring, 18. Guide slope, 19. Extrusion slope, 20. Second sealing ring, 21. Inlet pipe, 22. Exhaust pipe, 23. Switch valve, 24. Single-wall corrugated pipe, 25. Double-wall corrugated pipe, 26. Vent pipe, 27. Guide ring, 271. Vent groove, 28. Annular vent chamber, 29. Partition plate, 30. Rubber tube, 31. Sealing monitoring port. Detailed Implementation

[0033] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0034] Example 1:

[0035] like Figures 1-4 As shown, a double-acting gate valve for chemical production includes a valve body 1, with valve covers 2 detachably fixed to the upper and lower ends of the valve body 1. Two valve seats 3 are provided on the inner wall of the valve body 1, facing each other. Two delivery pipes 10, corresponding to the two valve seats 3, are fixed to the valve body, forming the valve's inlet and outlet.

[0036] Specifically, flanges are welded and fixed to both the upper and lower ends of the valve body 1. The valve cover 2 is bolted to the flanges, allowing for detachable fixing of the valve body 1 and valve cover 2 for easy disassembly. The valve seat 3 is bolted to the valve body 1, allowing for detachable fixing of the valve seat 3 and valve body 1 for easy replacement of the valve seat 3. In this embodiment, the delivery pipe and valve body are welded and fixed. One end of the delivery pipe 10 extends to the outside of the valve body 1, and the other end extends to the inside of the valve body. The valve seat 3 is fitted onto the port of the delivery pipe 10. During use, a flange can be welded to the end of the delivery pipe 10 located outside the valve body 1 for easy connection to other pipelines.

[0037] A piston cylinder 4 is provided between the two valve seats 3, extending in a left-right direction. Pistons 5 are slidably connected to both ends of the piston cylinder 4. Specifically, in this embodiment, the piston cylinder 4 is a cylindrical structure, coaxially arranged with the two valve seats 3. The outer diameter of the piston 5 matches the inner diameter of the piston cylinder 4, allowing the piston 5 to slide axially along the piston cylinder 4. The piston cylinder 4 and piston 5 are sealed by a first sealing ring 17. In this embodiment, the first sealing ring 17 is axially arranged and fixed on the inner wall of the piston cylinder 4. The inner diameter of the first sealing ring 17 matches the outer diameter of the piston 5, preventing fluid from entering the piston cylinder 4 through the sealing effect of the first sealing ring 17.

[0038] Two gate plates 6 are fixedly connected to the ends of the two pistons 5 that are far apart from each other, and the two gate plates 6 are respectively sealed to the two valve seats 3. Specifically, in this embodiment, the gate plate 6 and the piston 5 are fixedly connected by screws. The screws are located at the ends of the gate plate 6 that are far away from the piston 5, and the screws pass through the center of the gate plate 6 and connect to the piston 5, thereby realizing the detachable connection between the gate plate 6 and the piston 5, which facilitates the disassembly and replacement of the gate plate 6.

[0039] In this embodiment, a sealing gasket 13 is fixedly connected to the end of the gate plate 6 away from the piston 5. The sealing gasket 13 has an annular structure. A sealing gasket 13 is also fixedly connected to the side of the valve seat near the gate plate. During sealing, the sealing gasket 13 of the gate plate 6 presses against the sealing gasket 13 of the valve seat 3, achieving a sealing fit between the gate plate 6 and the valve seat 3, resulting in better sealing performance.

[0040] In this embodiment, a limiting post 12 supporting the piston cylinder 4 is fixedly connected to the valve cover 2 below. When the piston cylinder 4 contacts the limiting post 12, the gate plates 6 on both sides of the piston cylinder 4 are exactly opposite to the valve seat 3, which makes it convenient for personnel to control the up and down movement of the piston cylinder 4 and facilitates the docking of the gate plates with the valve seat.

[0041] A valve stem 8 is fixedly connected to the top of the piston cylinder 4. The upper end of the valve stem 8 extends through the valve cover 2 to the outside of the valve body. The valve stem 8 is slidably connected to the valve cover. The up-and-down movement of the valve stem 8 drives the piston cylinder 4 to move up and down. Specifically, in this embodiment, a retaining ring 11 is fixedly connected to the center of the top of the piston cylinder 4. The retaining ring 11 and the piston cylinder 4 are integrally formed. The inner diameter of the retaining ring 11 matches the outer diameter of the valve stem 8. The lower end of the valve stem 8 is inserted into the retaining ring 11 and fixed with screws, which facilitates the disassembly and replacement of the valve stem 8.

[0042] In this embodiment, the valve stem 8 and the insert ring 11 are sealed by a fourth sealing ring 16 to ensure the sealing between the valve stem 8 and the insert ring 11 and prevent gas from entering between them. In this embodiment, the valve cover 2 and the valve stem 8 are sealed by a second sealing ring 20, so that the valve stem 8 and the valve cover 2 are in a sealed sliding connection, ensuring the sealing between the valve stem 8 and the valve cover 2 and preventing gas leakage.

[0043] It also includes a drive assembly for driving the two pistons 5 to slide away from each other along the axial direction of the piston cylinder 4.

[0044] Specifically, in this embodiment, the driving component is a pressing rod 9 that passes through the valve stem 8 and slides up and down. The valve stem 8 is hollow. Guide blocks 7 are fixed to the ends of the two pistons 5 that are close to each other. Guide inclined surfaces 18 are provided on the sides of the two guide blocks 7 that are close to each other. The lower end of the pressing rod 9 passes through the piston cylinder 4 and extends between the two guide blocks 7. The lower end of the pressing rod 9 is provided with two pressing inclined surfaces 19, which respectively cooperate with the guide inclined surfaces 18 of the two guide blocks 7.

[0045] In this embodiment, the guide block 7 and piston 5 are integrally formed. The cross-section of the guide block 7 is frustoconical, thus forming two guide ramps 18. The lower end of the extrusion rod 9 has a trapezoidal cross-section, thus forming two extrusion ramps 19.

[0046] In this embodiment, the valve stem 8 and the extrusion rod 9 are sealed by a third sealing ring 15, so that the extrusion rod 9 and the valve stem 8 are in a sealed sliding connection, ensuring the sealing between the valve stem 8 and the extrusion rod 9 and preventing gas leakage.

[0047] Preferably, in this embodiment, both ends of the piston cylinder 4 are fixedly connected to outer sealing sleeves 14. The two outer sealing sleeves 14 are respectively fitted onto the two gate plates 6, with the inner wall of the outer sealing sleeve 14 slidingly sealingly contacting the outer wall of the gate plate 6. The outer diameter of the gate plate is the same as the outer diameter of the piston cylinder. The outer sealing sleeve 14 is fixed to the piston cylinder 4 by bolts, achieving detachable fixing and facilitating the removal and replacement of the outer sealing sleeve 14. When the gate plate 6 moves left and right, double sealing is achieved through the outer sealing sleeves, making the valve sealing more reliable.

[0048] The piston cylinder 4 and the piston 5 form an internal sealing structure through the first sealing ring 17, and then form an external sealing structure through the outer sealing sleeve and the gate plate, so as to ensure the sealing between the piston cylinder 4 and the piston 5 and prevent fluid from entering the piston cylinder.

[0049] In this embodiment, sealing monitoring ports 31 are fixedly connected to the left and right outer walls of the valve body 1, and on / off valves are installed on the sealing monitoring ports. When the valve is closed, a sealed space is formed inside the valve body. Nitrogen gas is injected into the valve body through one sealing monitoring port, which can provide all-round sealing for the valve stem, the two valve plates, and the valve seat, preventing toxic and harmful fluids from leaking through the valve stem, and also preventing leakage between the two gate valve seats. A pressure gauge can be installed on the other sealing monitoring port to monitor the internal pressure in real time, thereby monitoring the sealing status of the valve.

[0050] A method for using a double movable gate valve for chemical production includes the following steps: the valve stem 8 slides downward, driving the piston cylinder 4 to contact the limiting post 12, and the gate plates 6 on both sides of the piston cylinder 4 are opposite to the valve seats 3 on both sides of the valve body 1; the driving assembly causes the two pistons 5 to slide away from each other, thereby causing the two gate plates 6 to move away from each other and press against the two valve seats 3 respectively, so that the gate plates 6 and valve seats 3 are sealed and connected, and the gate is closed.

[0051] In this embodiment, the drive assembly slides downwards via the extrusion rod 9, causing the two extrusion ramps 19 to engage with the two guide ramps 18. As the extrusion rod 9 moves downwards, the extrusion ramps 19 slide downwards along the guide ramps 18, pushing the two guide blocks 7 to the left and right sides. This causes the two pistons 5 to slide away from each other, thereby causing the two gates 6 to move away from each other and press against the two valve seats 3, achieving a sealed connection between the gates 6 and the valve seats 3, and thus sealing the delivery pipe 10. The extrusion of the extrusion rod 9 causes the two gates 6 to move horizontally and seal against the valve seats 3 on both sides. This significantly reduces friction between the gates 6 and the valve seats 3 when opening or sealing the delivery pipe, preventing wear and making the valve more durable. When the valve is closed, nitrogen is injected into the valve body through one monitoring port to provide a comprehensive seal inside the valve body. During maintenance, the lower valve cover 2 can be opened to inspect and replace the seals and remove accumulated dust.

[0052] Example 2:

[0053] like Figure 5 As shown, the difference between this embodiment and embodiment 1 is that the extrusion rod in this embodiment is hollow, and an air inlet pipe 21 is fixedly connected in the cavity of the extrusion rod 9. The air inlet pipe 21 extends along the length of the extrusion rod 9 and passes through the extrusion rod 9. The upper end of the air inlet pipe 21 is connected to an external fluid source, and an exhaust pipe 22 is connected to the air inlet pipe 21. A switch valve 23 is installed on both the air inlet pipe 21 and the exhaust pipe 22.

[0054] Specifically, the external fluid source can be a high-pressure gas tank or a high-pressure liquid tank, through which high-pressure gas or high-pressure liquid is injected into the piston cylinder.

[0055] Specifically, in this embodiment, the intake pipe 21 includes a straight pipe section passing through the extrusion rod 9 and a flexible hose section connected to the straight pipe section. The flexible hose section is connected to an external fluid source. After the intake pipe is connected to the external fluid source through the flexible hose section, the intake pipe 21 can move up and down with the extrusion rod 9 without deformation or damage. In this embodiment, the exhaust pipe 22 is connected to the straight pipe section of the intake pipe 21 through a tee fitting.

[0056] In this embodiment, after the extrusion rod 9 presses the two gate plates 6 to seal and connect with the two valve seats 3 respectively, an external fluid source can inject high-pressure fluid into the piston cylinder 4 through the air inlet pipe 21. The high-pressure fluid is injected between the two pistons 5, thereby further pressurizing the two gate plates 6, thus improving the sealing effect between the gate plates 6 and the valve seats 3, and improving the sealing performance. When it is necessary to open the valve, the switch valve 23 of the exhaust pipe 22 is opened to discharge the gas. The extrusion rod 9 is lifted upwards, and the two gate plates 6 will naturally loosen due to the loss of the extrusion effect. Driven by the gas in the delivery pipe 10, they will disconnect from the valve seats 3. The valve rod 8 is then lifted upwards, causing the piston cylinder 4 to move upwards, thereby opening the valve.

[0057] Example 3:

[0058] The difference between this embodiment and embodiment 2 is that in this embodiment, the outer sealing sleeves 14 are not provided at the left and right ends of the piston cylinder 4.

[0059] like Figure 6 , 7 As shown in the figure, a single-walled bellows 24 is provided between the piston cylinder 4 and the gate 6 in this embodiment. One end of the single-walled bellows 24 is sealed and fixedly connected to the piston cylinder 4, and the other end of the single-walled bellows 24 is sealed and fixedly connected to the gate 6. Specifically, the single-walled bellows 24 includes a single-layer bellows wall, and sealing rings are fixedly connected to both ends of the single-layer bellows wall. The single-walled bellows 24 is sleeved on the piston cylinder 4, and the single-walled bellows is bolted to the piston cylinder 4 and the gate 6 respectively through the sealing rings on both sides, which facilitates disassembly. When the gate 6 moves, the single-walled bellows can improve the sealing effect between the gate and the piston cylinder, thereby improving the airtightness.

[0060] In this embodiment, a hollow double-walled corrugated pipe 25 is provided between the gate 6 and the valve seat 3. The double-walled corrugated pipe 25 is fixedly connected to the valve seat 3, and a vent pipe 26 is fixedly connected to the valve body 1. One end of the vent pipe 26 communicates with the inner cavity of the double-walled corrugated pipe 25, and a switch valve 23 is installed on the vent pipe 26. In this embodiment, two vent pipes 26 are connected to one double-walled corrugated pipe 25. One vent pipe 26 is used for air intake, and the other vent pipe 26 is used for air exhaust, making it more convenient to use.

[0061] Specifically, the double-walled bellows 25 includes two coaxially arranged bellows walls, forming an annular cavity between them. Sealing rings are fixed to both ends of the double-walled bellows walls. During installation, the double-walled bellows 25 is fitted onto the valve seat 3. The sealing ring on one side of the double-walled bellows 25 is fixed to the valve seat 3 with bolts for easy disassembly. The sealing ring on the other side of the double-walled bellows 25 is opposite to the sealing gasket 13 of the gate 6, allowing for sealing contact with this sealing ring when the gate 6 moves.

[0062] In this embodiment, when the gate 6 moves and aligns with the valve seat 3, the sealing gasket 13 on the gate 6 and the sealing gasket 13 at the end of the valve seat 3 form a first sealing structure through sealing contact. Simultaneously, the sealing gasket 13 of the gate 6 also forms a second sealing structure through sealing contact with the sealing ring of the double-walled bellows 25. High-pressure fluid is introduced into the double-walled bellows 25 through the vent pipe 26. This high-pressure fluid pushes the double-walled bellows to extend and retract, tightly fitting it against the gate 6, further improving the sealing effect.

[0063] Example 4:

[0064] like Figure 8 , 9As shown, the difference between this embodiment and Embodiment 1 is that an annular venting cavity 28 is formed between the extrusion rod 9 and the valve rod 8 in this embodiment, and the annular venting cavity 28 is connected to the inner cavity of the piston cylinder 4. The inlet-side delivery pipe 10 is connected to the annular venting cavity 28 through the air inlet pipe 21, and the outlet-side delivery pipe 10 is connected to the annular venting cavity 28 through the exhaust pipe 22. Switch valves 23 are installed on both the air inlet pipe 21 and the exhaust pipe 22.

[0065] In this embodiment, both the intake pipe 21 and the exhaust pipe 22 include a straight pipe section and a flexible pipe section. The straight pipe section is fixedly connected to the delivery pipe 10, and one end of the flexible pipe section is connected to the straight pipe section. The other end of the flexible pipe section passes through the valve stem 8 and is connected to the annular ventilation chamber 28. The intake pipe and the exhaust pipe move up and down with the valve stem through the flexible pipe section without deformation or damage.

[0066] Preferably, since there is a cavity between the valve stem 8 and the extrusion rod 9, to ensure the stability of the extrusion rod 9 during its up-and-down sliding, an annular groove is provided at the lower end of the inner cavity of the valve stem 8. A guide ring 27 is embedded in the annular groove. The inner diameter of the guide ring 27 is adapted to the outer diameter of the extrusion rod 9, and multiple venting grooves 271 are provided circumferentially on the inner wall of the guide ring 27. The guide ring 27 guides the up-and-down sliding of the extrusion rod 9, making the sliding more stable. The venting grooves 271 on the guide ring are used for ventilation.

[0067] In this embodiment, after the extrusion rod 9 presses the two gate plates 6 to seal and connect them with the two valve seats 3, the gas in the inlet-side delivery pipe 10 can be introduced into the piston cylinder 4 through the air inlet pipe 21 to fill it with high-pressure fluid. This high-pressure fluid fills the space between the two pistons 5, further pressurizing the two gate plates 6, thereby improving the sealing effect between the gate plates 6 and the valve seats 3, and enhancing the sealing performance. This embodiment utilizes the gas delivered by its own pipeline to improve the valve's sealing effect, eliminating the need for an external fluid source, saving operating costs, and making it more convenient to use.

[0068] Example 5:

[0069] like Figure 10 , 11 As shown, the difference between this embodiment and Embodiment 1 is that the driving component in this embodiment does not use a compression rod.

[0070] In this embodiment, the driving assembly consists of two intake pipes 21 fixedly connected to the valve stem. A partition plate 29 is fixedly connected inside the piston cylinder 4 between the two pistons 5, forming an inflation chamber between the pistons 5 and the partition plate 29. Both intake pipes 21 pass through the valve stem 8 and communicate with the two inflation chambers respectively. Each intake pipe 21 is connected to an external fluid source, and each intake pipe 21 is connected to an exhaust pipe 22. A switching valve 23 is installed on both the intake pipe 21 and the exhaust pipe 22.

[0071] In this embodiment, the intake pipe 21 includes a straight pipe section passing through the valve stem 8 and a flexible hose section connected to the straight pipe section. The flexible hose section is connected to an external fluid source. After the intake pipe 21 is connected to the external fluid source through the flexible hose section, the intake pipe 21 can move up and down with the valve stem 8 without deformation or damage. In this embodiment, the exhaust pipe 22 is connected to the straight pipe section of the intake pipe 21 through a tee fitting.

[0072] In this embodiment, the drive assembly divides the piston cylinder 4 into two inflation chambers via the partition plate 29. An external fluid source, through two air inlet pipes 21, delivers high-pressure fluid to each of the two inflation chambers, pressurizing the pistons 5 and allowing them to slide independently. Once the two gate plates 6 are sealed to the two valve seats 3, if one piston leaks or is damaged, simply driving the other piston will seal the valve. During maintenance, the damaged piston can be repaired. The valve can operate normally even with one piston damaged, making operation more economical, safer, and more convenient.

[0073] Preferably, in this embodiment, a hollow rubber tube 30 is provided between the gate 6 and the valve seat 3. The rubber tube 30 is annular and fixedly connected to the valve seat 3. A vent pipe 26 is fixedly connected to the valve body 3. One end of the vent pipe 26 communicates with the inner cavity of the rubber tube 30, and a switch valve 23 is installed on the vent pipe 26. In this embodiment, two vent pipes 26 are connected to one rubber tube 30. One vent pipe 26 is used for air intake, and the other vent pipe 26 is used for air exhaust, making it more convenient to use.

[0074] The specific rubber tube 30 is sleeved on the valve seat 3. One side of the rubber tube 30 is fixedly connected to the valve seat 3, and the other side is opposite to the sealing gasket 13 of the gate 6. When the gate 6 moves, it can seal and connect with the rubber tube 30.

[0075] When the gate 6 moves and aligns with the valve seat 3, the sealing gasket 13 on the gate 6 and the sealing gasket 13 at the end of the valve seat 3 form a first sealing structure. Simultaneously, the sealing gasket 13 of the gate 6 also forms a second sealing structure by sealing with the rubber tube 30. High-pressure fluid is injected into the rubber tube 30 through the vent pipe 26, causing the rubber tube to expand and elastically fit against the gate 6, further improving the sealing effect.

[0076] Of course, the above description is not limited to the examples above. Technical features of this utility model not described can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solution of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model.

Claims

1. A double-acting gate valve for chemical production, comprising a valve body (1), with valve covers (2) fixedly connected to the upper and lower ends of the valve body, characterized in that: The valve body (1) has two valve seats (3) facing each other on the inner wall. Two delivery pipes (10) corresponding to the two valve seats (3) are fixedly connected to the valve body. A piston cylinder (4) is provided between the two valve seats (3). Pistons (5) are slidably connected to both ends of the piston cylinder (4). Gate plates (6) are fixedly connected to the ends of the two pistons (5) that are far apart from each other. The two gate plates (6) are respectively sealed to the two valve seats (3). A valve stem (8) is fixedly connected to the top of the piston cylinder (4). The upper end of the valve stem extends to the outside through the valve cover (2). The valve body (4) also includes a drive assembly for driving the two pistons (5) to slide away from each other along the axial direction of the piston cylinder (4).

2. The double-acting gate valve for chemical production according to claim 1, characterized in that: The valve stem (8) is hollow, and guide blocks (7) are fixed to the ends of the two pistons (5) that are close to each other. Guide slopes (18) are provided on the sides of the two guide blocks (7) that are close to each other. The driving component is a pressing rod (9) that passes through the valve stem (8) and slides up and down. The lower end of the pressing rod (9) extends through the piston cylinder (4) to the space between the two guide blocks (7). The lower end of the pressing rod (9) is provided with two pressing slopes (19). The two pressing slopes (19) cooperate with the guide slopes (18) of the two guide blocks (7) respectively.

3. The double-acting gate valve for chemical production according to claim 2, characterized in that: An air inlet pipe (21) is provided in the extrusion rod (9). The air inlet pipe (21) extends along the length of the extrusion rod (9) and passes through the extrusion rod (9). The upper end of the air inlet pipe (21) is connected to an external fluid source. An exhaust pipe (22) is connected to the air inlet pipe. A switch valve (23) is installed on both the air inlet pipe and the exhaust pipe.

4. The double-acting gate valve for chemical production according to claim 2, characterized in that: An annular ventilation chamber (28) is formed between the extrusion rod (9) and the valve rod (8). One of the delivery pipes (10) is connected to the annular ventilation chamber (28) through the air inlet pipe (21), and the other delivery pipe (10) is connected to the annular ventilation chamber (28) through the exhaust pipe (22). Switch valves (23) are installed on both the air inlet pipe and the exhaust pipe.

5. The double-acting gate valve for chemical production according to claim 4, characterized in that: The valve stem (8) has an annular groove at its lower end, and a guide ring (27) is embedded in the annular groove. The inner diameter of the guide ring is adapted to the outer diameter of the extrusion rod (9). The inner wall of the guide ring (27) has multiple venting grooves (271) along the circumferential direction.

6. The double-acting gate valve for chemical production according to claim 1, characterized in that: The piston cylinder (4) is fixedly connected to a partition plate (29) located between two pistons (5). An air filling chamber is formed between the piston (5) and the partition plate (29). The drive assembly consists of two air inlet pipes (21) fixedly connected to the valve stem (8). Both air inlet pipes pass through the valve stem (8) and are connected to the two air filling chambers respectively. The two air inlet pipes (21) are respectively connected to an external fluid source. The two air inlet pipes (21) are respectively connected to an exhaust pipe (22). A switch valve (23) is installed on both the air inlet pipe and the exhaust pipe.

7. The double-acting gate valve for chemical production according to any one of claims 1 to 6, characterized in that: The piston cylinder (4) is fixed with outer sealing sleeves (14) at both ends, and the two outer sealing sleeves (14) are respectively fitted on the two gates (6).

8. The double-acting gate valve for chemical production according to any one of claims 1 to 6, characterized in that: A single-walled bellows (24) is provided between the piston cylinder (4) and the gate (6). One end of the single-walled bellows (24) is sealed and fixed to the piston cylinder (4), and the other end of the single-walled bellows is sealed and fixed to the gate (6).

9. The double-acting gate valve for chemical production according to claim 8, characterized in that: A hollow double-walled corrugated pipe (25) is provided between the gate (6) and the valve seat (3). The double-walled corrugated pipe (25) is fixedly connected to the valve seat (3). A vent pipe (26) is fixedly connected to the valve body. One end of the vent pipe (26) is connected to the inner cavity of the double-walled corrugated pipe (25). A switch valve (23) is installed on the vent pipe (26).

10. The double-acting gate valve for chemical production according to claim 8, characterized in that: A hollow rubber tube (30) is provided between the gate (6) and the valve seat (3). The rubber tube (30) is annular and fixedly connected to the valve seat (3). A vent pipe (26) is fixedly connected to the valve body. One end of the vent pipe (26) is connected to the inner cavity of the rubber tube (30). A switch valve (23) is installed on the vent pipe (26).

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