A fall-prevention gate valve for gas pipelines

Abstract

This invention relates to the field of gate valve technology, specifically disclosing an anti-fall gate valve for gas pipelines. The anti-fall gate valve for gas pipelines of this invention includes a housing, a gate plate slidably disposed within the housing, a sealing tube, a sealing drive assembly, and a gate plate drive assembly for moving the gate plate. The gate plate drive assembly includes a gate plate connecting frame fixedly connected to the gate plate. The sealing tube is slidably disposed within the housing, with its axial direction perpendicular to the moving direction of the gate plate. The sealing drive assembly includes a first rack plate, a second rack plate, and a gear component. Both the first and second rack plates are fixedly disposed on the gate plate connecting frame and can mesh with the gear component. The gear component is helically engaged with the sealing tube. When the gate plate connecting frame and the gate plate move, the sealing tube is moved closer to or away from the gate plate. The anti-fall gate valve for gas pipelines of this invention has a better effect in preventing gas leakage.

Description

Technical Field

[0001] This invention relates to the field of gate valve technology, and more specifically to an anti-fall gate valve for gas pipelines. Background Technology

[0002] In gas pipelines, gate valves are core shut-off devices that ensure safety, enable segmented control, and guarantee efficient delivery. Their main function is to provide reliable complete closure, isolation, shut-off, and near-unobstructed full-open states. If a gate valve in a gas pipeline fails to seal, it can lead to gas leakage and waste of resources. Furthermore, since gas is toxic, it can cause acute poisoning of workers. Therefore, ensuring the sealing effect of gate valves is crucial.

[0003] Patent document CN111895173B discloses a gate valve, including a valve body with an inlet flow channel and an outlet flow channel; a gate plate slidably disposed within the valve body; and a valve stem rotatably connected to the upper end of the gate plate and threadedly connected to the valve body. Rotating the valve stem can drive the gate plate to move vertically. A balancing valve sleeve is fixedly connected to the valve stem. The balancing valve sleeve includes an upper bushing portion and a lower limiting portion. Multiple cavities are formed between the bushing portion, the valve body, and the limiting portion. Multiple channels are provided on the valve body and the gate plate. When the gate plate is opened or closed, liquid is guided to different cavities through the multiple channels to balance the force on the gate plate.

[0004] The following problems exist in this solution: When the gate valve is opened or closed, the gate moves up and down in the valve body under the action of the valve stem. That is, the sealing surface on the gate and the sealing surface on the valve body slide relative to each other, which will cause wear on the sealing surfaces of the gate and the valve body. Furthermore, when the gate valve is in the open state, the sealing surface on the valve body is always in contact with the medium in the pipeline, which will be corroded by the medium in the pipeline, and impurities will be adsorbed on the sealing surface, affecting the sealing effect when the gate valve is closed. Summary of the Invention

[0005] This invention provides an anti-fall gate valve for gas pipelines, aiming to solve the problem of sealing failure caused by friction of the sealing surface when opening and closing the gate valve in related technologies.

[0006] The present invention provides an anti-fall gate valve for a gas pipeline, comprising a housing, a gate plate that slides up and down within the housing to control the opening and closing of the gate valve, a sealing tube, a sealing drive assembly, and a gate plate drive assembly that drives the gate plate to move up and down within the housing, wherein two sealing tubes are provided, the two sealing tubes are slidably disposed on both sides of the gate plate and both sealing tubes slide toward the gate plate, and the sealing drive assembly is connected to the sealing tubes to adjust the position of the sealing tubes.

[0007] When the gate valve is opened, the gate moves upward, and the sealing drive assembly drives the sealing tube away from the gate. After the gate moves out from between the sealing tubes, the sealing drive assembly drives the two sealing tubes to abut against each other.

[0008] When the gate valve is closed, the gate moves downward, and the sealing drive assembly controls the two sealing tubes to move away from each other. When the gate moves to the closed position of the gate valve, the sealing drive assembly controls the two sealing tubes to come into contact with the gate.

[0009] Its effect lies in the fact that the gate assembly drives the gate to move up and down, cooperating with the sealing pipes to achieve the connection and closure of the gas pipeline. When the gate valve switches between the closed and open states, that is, during the up and down movement of the gate, the sealing pipes on both sides initially move away from the gate. When the gate moves to the designated position, the sealing pipes move closer together under the action of the sealing pipe drive assembly. In the open state of the gate valve, a seal is formed between the sealing pipes on both sides; in the closed state of the gate valve, a seal is formed between the sealing pipes on both sides and the gate. This effectively avoids friction between the sealing surfaces of the gate and the sealing pipes, preventing damage to their sealing surfaces. At the same time, in the open state of the gate valve, the sealing surfaces of the sealing pipes on both sides abut against each other, which can prevent the gas and impurities in the pipeline from corroding the sealing surface, and also reduce the adsorption of impurities carried in the gas on the sealing surface, thus improving the sealing effect and extending the service life and sealing effect of the sealing pipe sealing surface. Furthermore, when the gate valve is in the open state, the sealing pipes on both sides simultaneously form a seal for the gas pipeline, and the double-layer sealing effect can better prevent gas leakage problems.

[0010] Preferably, the sealing drive assembly includes a first rack plate, a second rack plate, and a gear component. The first rack plate and the second rack plate are fixedly mounted on the gate drive assembly. The gear component is coaxially mounted with the sealing tube and helically engaged. The first rack plate and the second rack plate mesh with the gear component for transmission, and the gear component is positioned between the first rack plate and the second rack plate. When the gate valve is opened, the gate drive assembly drives the gate to move upward. The first rack plate and the second rack plate are arranged along the direction of the gate's movement so that the first rack plate and the second rack plate engage with the gear component successively to drive the gear component to rotate in opposite directions. When the first rack plate engages with the gear component, the two sealing tubes move away from the gate. When the second rack plate engages with the gear component, the two sealing tubes move closer together to form a seal after the gate moves out from between the sealing tubes.

[0011] Its effect is that by fixing rack plate one and rack plate two at different heights in the gate drive assembly, they can mesh with the gear components on both sides in sequence, thereby driving the sealing pipes on both sides to move closer to and further away from the gate.

[0012] Preferably, the gate drive assembly includes a drive handwheel, a drive sleeve, a drive rod, and a gate connecting frame. The drive handwheel is rotatably mounted on the housing. The drive rod is screw-fitted with the drive sleeve, which is fixedly mounted on the drive handwheel. The gate is fixedly mounted on the drive rod via the gate connecting frame. The drive rod is slidably mounted on the housing.

[0013] Its effect is that, through the screw-fitted drive sleeve and drive rod, and the drive rod that slides along the axial direction of the drive sleeve, the drive sleeve is rotated relative to the drive rod by rotating the drive handwheel, thereby controlling the up and down movement of the gate.

[0014] Preferably, an elastic element is provided between the gate connecting frame and the gate to connect the two.

[0015] Its effect is that, through the setting of the elastic element one, after the gate moves down to the designated position, the gate connecting frame can continue to move down relative to the gate. Then, through the meshing of the rack plate one and the gear component, it continues to drive the sealing tube to move closer to the gate, so that there is no friction between the sealing tube and the gate in the direction of gate movement, reducing the wear of the sealing surface, and making the seal tighter.

[0016] Preferably, a detection component is provided on the housing. The detection component includes a limiting tube, an elastic element II, a sliding element, and a guide block. The limiting tube is fixedly disposed on the housing, the guide block is fixedly disposed inside the limiting tube, the sliding element is slidably disposed on the guide block, and the sliding element is slidably sealed with the limiting tube. An elastic element II is disposed between the sliding element and the guide block.

[0017] Its effect is to detect whether there is a sealing failure in the gate valve by changing the position of the sliding element inside the limit tube.

[0018] Preferably, the sliding member includes a piston plate, a connecting rod, and a stop plate. The guide block is provided with a through hole adapted to the connecting rod. The connecting rod is slidably disposed in the through hole. The piston plate and the stop plate are respectively fixedly disposed at both ends of the connecting rod. The area of ​​the stop plate is larger than the cross-sectional area of ​​the connecting rod, so that the stop plate is always on the side of the guide block away from the elastic member.

[0019] Its effect is that the position of the piston plate can be adjusted through the stop plate.

[0020] Preferably, a sliding limit member is slidably provided on the guide block. When the gate valve is opened and closed, the sliding limit member slides between the stop plate and the guide block. The sliding limit member cooperates with the elastic member to make the sliding limit member abut against the stop plate and limit the position of the stop plate relative to the guide block.

[0021] Its effect is that by the sliding limiter abutting against the stop plate, the position of the piston plate is restricted, preventing the change of internal air pressure when the gate valve is opened and closed from affecting its position, so that the position of the piston plate is always in the initial state, making it convenient to detect whether there is a sealing failure in the gate valve by the change of the piston relative to the initial position.

[0022] Preferably, multiple rollers are evenly arranged on the gate plate, the rollers are rotatably mounted on the gate plate, and the rollers abut against the inner wall of the housing.

[0023] Its effect is to improve the stability of the gate when it moves up and down, while reducing the friction between the gate and the inside of the housing.

[0024] Preferably, an impurity receiving cavity is provided at the bottom of the housing, and a gate limiting plate is fixedly provided on the side wall of the housing. The gate limiting plate abuts against the gate when the gate descends, limiting the gate to the lowest position in the housing. The space between the gate and the housing is the impurity receiving cavity.

[0025] Its effect is to collect impurities inside the housing, prevent impurities at the bottom of the gate valve from directly contacting it, and avoid the accumulation of impurities affecting the descent position of the gate and the sealing effect.

[0026] Preferably, a ash discharge port is provided at the bottom of the shell, which penetrates the shell and communicates with the impurity receiving cavity. A cleaning pipe is provided on the shell, which penetrates the shell and communicates with the interior of the shell, and is located above the impurity receiving cavity.

[0027] Its effect is that it can better remove impurities from the impurity containment cavity from the shell.

[0028] Beneficial effects:

[0029] 1. When the gate moves up and down inside the gate valve, the sealing surface of the sealing tube and the sealing surface of the gate valve are always separated, and no friction occurs, which avoids damage to the sealing surface and improves the service life and sealing effect of the sealing tube and the gate sealing surface.

[0030] 2. When the gate valve is in the open or closed state, it provides a double seal for the gas, which can effectively prevent gas leakage.

[0031] 3. When the gate valve is in the open position, the sealing pipes on both sides abut to form a seal, which prevents the gas and impurities in the gas from coming into contact with the sealing surface for a long time, and prevents the sealing surface from being corroded or impurities from being adsorbed on the sealing surface, thus affecting its sealing effect.

[0032] 4. A detection device is installed on the gate valve body to detect the sealing effect of the gate valve and promptly identify any sealing failures. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the present invention.

[0034] Figure 2 yes Figure 1 A schematic diagram of the structure at point A in the middle.

[0035] Figure 3This is a schematic diagram of the structure of the gate and sealing tube in this invention.

[0036] Figure 4 This is a schematic diagram showing the positions of tooth condition one and tooth condition two in this invention.

[0037] Figure 5 yes Figure 1 A cross-sectional schematic diagram.

[0038] Figure 6 yes Figure 5 A schematic diagram of the structure at point B.

[0039] Figure 7 yes Figure 5 A schematic diagram of the structure at point C.

[0040] Figure 8 yes Figure 5 A schematic diagram of the structure at point D.

[0041] Figure 9 This is a schematic diagram of the sealing drive assembly in this invention.

[0042] Figure 10 yes Figure 9 A schematic diagram of the structure at point E in the middle.

[0043] Figure 11 This is a schematic diagram of the gate valve in the open position.

[0044] Reference numerals: 1. Shell; 11. Upper shell; 111. Protective tube; 12. Lower shell; 122. Gate limiting plate; 123. Impurity receiving cavity; 124. Ash discharge port; 125. Cleaning pipe; 13. Sealing groove; 131. Limiting groove; 2. Gate drive assembly; 21. Drive handwheel; 22. Drive sleeve; 221. Cavity; 222. Spiral groove one; 23. Drive rod; 24. Gate connecting frame; 25. Drive limiting block; 26. Elastic element one 3. Sealing tube; 31. Key block; 4. Sealing drive assembly; 41. Rack plate one; 42. Rack plate two; 43. Gear component; 431. Transmission gear; 432. Helical slider; 5. Gate plate; 51. Connecting plate; 52. Roller; 53. Gate plate limit rod; 6. Detection assembly; 61. Limiting tube; 62. Sliding component; 621. Piston plate; 622. Connecting rod; 623. Stop plate; 63. Elastic component two; 64. Guide block; 65. Sliding limit component. Detailed Implementation

[0045] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0046] Reference Figures 1 to 11 This invention discloses an anti-fall gate valve for gas pipelines, comprising a housing 1 and a gate 5. The housing 1 contains a gate drive assembly 2, a sealing pipe 3, and a sealing drive assembly 4. Two sealing pipes 3 are provided and positioned on either side of the gate 5. The gate drive assembly 2 controls the up-and-down movement of the gate 5 within the housing 1, and the sealing drive assembly 4 drives the sealing pipes 3 to move relative to the gate 5. The sealing pipes 3 cooperate with the gate 5 to close and open the gas pipeline.

[0047] When the gate valve needs to be opened, the sealing pipe 3 is moved away from the gate plate 5 by the sealing drive assembly 4. Then, the gate plate 5 is moved upward by the gate drive assembly 2 until it is out of the end face range of the sealing pipe 3. Then, the sealing pipe 3 on both sides is brought closer to each other by the sealing drive assembly 4 until the two sealing pipes 3 come into contact. When the gate valve needs to be closed, the two sealing pipes 3 are first separated by the sealing drive assembly 4, and the distance between them is greater than the width of the gate plate 5. Then, the gate plate 5 is moved downward by the gate drive assembly 2 to the designated position. Then, the two sealing pipes 3 are moved towards the gate plate 5 by the sealing drive assembly 4 until they come into contact with the gate plate 5, thus closing the gate valve.

[0048] Reference Figure 1 The housing 1 includes an upper housing 11 and a lower housing 12. A sealing gasket is provided between the upper housing 11 and the lower housing 12 to seal the space between them. The upper housing 11 and the lower housing 12 are connected by multiple fastening bolts.

[0049] Reference Figures 3 to 6 The gate drive assembly 2 includes a drive handwheel 21, a drive sleeve 22, a drive rod 23, and a gate connecting frame 24. The drive handwheel 21 is rotatably mounted on the upper housing 11, and the drive sleeve 22 is coaxially fixedly mounted on the drive handwheel 21. A cavity 221 is axially formed inside the drive sleeve 22, and a spiral groove 222 is formed on the inner wall of the drive sleeve 22. The drive rod 23 is coaxially arranged inside the cavity 221, and a spiral protrusion (not shown in the figure) is provided on the outer wall of the drive rod 23 to match the spiral groove 222. That is, the drive rod 23 and the drive sleeve 22 are spirally engaged to prevent the gate 5 from moving without human intervention and to prevent the gate 5 from falling. A drive limiting block 25 is fixedly mounted on the upper housing 11. The drive limiting block 25 is keyway engaged with the drive rod 23, that is, the drive rod 23 can only slide relative to the drive limiting block 25 along the axial direction of the drive rod 23. The end of the drive rod 23 away from the drive sleeve 22 is fixedly connected to the gate connecting frame 24. The gate 5 is set on the gate connecting frame 24 and is circular.

[0050] The operator manually rotates the drive handwheel 21, which drives the drive sleeve 22 to rotate synchronously. Under the action of the drive limit block 25, the drive sleeve 22 rotates relative to the drive rod 23. Since the drive sleeve 22 and the drive rod 23 are screwed together, the drive rod 23 will move axially relative to the drive sleeve 22. The movement of the drive rod 23 drives the gate plate 5 connector to move synchronously, thereby driving the gate plate 5 to move up and down inside the housing 1.

[0051] Reference Figure 3 , Figure 4 , Figure 9 and Figure 10 The sealing tube 3 is slidably mounted on the lower housing 12, and the axial direction of the sealing tube 3 is perpendicular to the moving direction of the gate 5. The sealing tube 3 can slide relative to the valve body along its axial direction. A sealing groove 13 adapted to the sealing tube 3 is provided on the lower housing 12, and the sealing groove 13 and the sealing tube 3 are slidably sealed together. In this embodiment, there are two sealing tubes 3, which are located on both sides of the gate 5, and the end face of the sealing tube 3 corresponds to the end face of the gate 5. After the gate drive assembly 2 moves the gate 5 downward to the designated position, the two sealing tubes 3 are moved to abut against the gate 5 to form a seal, at which point the gate valve is in the closed state. Sealing surfaces are provided at the ends of the sealing tubes 3 on both sides, and sealing surfaces are also provided at the contact points between the gate 5 and the sealing surfaces of the sealing tubes 3, which can ensure a better sealing effect between the sealing tubes 3 and the gate 5.

[0052] Reference Figure 3 , Figure 4 , Figure 9 and Figure 10 The sealing drive assembly 4 includes a first rack plate 41, a second rack plate 42, and a gear component 43. Both the first rack plate 41 and the second rack plate 42 are fixedly mounted on the gate plate 5 connector, and correspond to the arc side of the gate plate 5. The gate plate 5 is located between the first rack plate 41 and the second rack plate 42. Racks are provided on both the first rack plate 41 and the second rack plate 42, and the racks face the gate plate 5. The racks on the first rack plate 41 and the second rack plate 42 are at different heights, with the rack on the first rack plate 41 being higher than the rack on the second rack plate 42.

[0053] Reference Figure 3 , Figure 9 and Figure 10The gear component 43 is rotatably mounted on the lower housing 12. The gear component 43 is configured as a sleeve and is coaxially mounted with the sealing tube 3. A groove adapted to the gear component 43 is provided on the lower housing 12. The gear component 43 is rotatably mounted in the groove. A transmission gear 431 adapted to the rack on the rack plate 41 and the rack plate 42 is provided on the side of the gear component 43 away from the groove. That is, the transmission gear 431 can mesh with the rack installed on the rack plate 41 and the rack plate 42. Since the rack on the rack plate 41 and the rack plate 42 has different heights, the rack plate 41 and the rack plate 42 will not mesh with the transmission gear 431 at the same time.

[0054] The gear component 43 is adapted to the sealing tube 3, that is, the outer diameter of the sealing tube 3 is the same as the inner diameter of the gear component 43. A spiral protrusion is provided on the outside of the sealing tube 3, and a spiral groove 2 adapted to the spiral slider 432 is provided on the inside of the gear component 43 (the spiral groove 2 coincides with the spiral slider 432). That is, the gear component 43 and the sealing tube 3 are spirally fitted. A limiting groove 131 extending along the axial direction of the sealing tube 3 is provided in the sealing groove 13. A key block 31 adapted to the limiting groove 131 is provided on the inside of the sealing tube 3. There are two gear components 43, and the two gear components 43 are correspondingly set with the two sealing tubes 3. The racks on the rack plate 1 41 and rack plate 2 42 are respectively corresponding to the transmission gears 431 on the gear components 43 on both sides of the gate plate 5.

[0055] When the drive rod 23 moves the gate connecting frame 24, the gate connecting frame 24 moves the rack plate 41 and the rack plate 42. When the rack plate 41 or the rack plate 42 meshes with the transmission gear 431, it will drive the transmission gear 431 to rotate. The transmission gear 431 drives the gear component 43 to rotate. The gear component 43 and the sealing tube 3 are in a helical fit, and the sealing tube 3 and the sealing groove 13 are in a keyway fit. When the gear component 43 rotates relative to the sealing tube 3, the sealing tube 3 slides axially relative to the gear component 43, that is, the sealing tube 3 moves away from or closer to the gate 5.

[0056] Reference Figure 11When the gate 5 is located within the space of the upper housing 11 and the two sealing pipes 3 in the lower housing 12 are in contact, the gate valve is in the open state. When it is necessary to close the gate valve, the drive handwheel 21 is turned, which drives the gate 5 downward through the downward-moving drive rod 23. When the gate connecting frame 24 moves downward, the rack plate 42 first engages with the transmission gear 431, driving the two gear components 43 to rotate, which in turn drives the sealing pipes 3 on both sides away from the gate 5, making room for the gate 5 to move downward. As the gate connecting frame 24 continues to move downward, the rack plate 42 disengages from the transmission gears 431 on both sides of the gate 5. As the gate connecting frame 24 moves downward, the rack plate 41 engages with the transmission gear 431, driving the gear components 43 to rotate in the opposite direction, causing the two sealing pipes 3 to move towards the gate 5 until the end faces of the two sealing pipes 3 abut against the gate 5, sealing the sealing pipes 3. At this moment, the gate valve is in the closed state.

[0057] When the gate valve is in the open state, the end faces of the sealing pipes 3 on both sides abut against each other to form a seal, which, together with the seal of the shell 1 for the gate valve, forms a double seal, effectively preventing gas leakage. At the same time, the sealing surfaces at the ends of the two sealing pipes 3 abut against each other, which can effectively prevent gas and impurities in the gas from contacting the sealing surface and causing corrosion to the sealing surface, affecting the sealing effect or service life of the sealing surface.

[0058] Reference Figure 4 , Figure 6 , Figure 8 and Figure 9 An elastic element 26 is provided between the gate connecting frame 24 and the gate 5, with both ends of the elastic element 26 fixedly mounted on the gate connecting frame 24 and the gate 5, respectively. A gate limiting rod 53 is fixedly mounted on the gate 5. A through hole adapted to the gate limiting rod 53 is provided on the gate connecting frame 24, meaning that the gate limiting rod 53 slides within the through hole on the gate connecting frame 24. Multiple gate limiting rods 53 are provided, and the gate 5 limiting element also has through holes adapted to each of the multiple gate limiting rods 53. The through holes are provided to prevent the gate 5 from rotating relative to the gate connecting frame 24.

[0059] The elastic element 26 allows the gate 5 to move to the designated closed position when it moves downwards to close the gate valve. After the gate 5 stops moving downwards, the gate connecting frame 24 can continue to move downwards, meaning the two gears 43 continue to rotate. This drives the sealing pipes 3 on both sides to move towards the gate 5 until they abut against it. At this point, there is only relative movement between the gate 5 and the sealing pipes 3 along the axial direction of the sealing pipes 3. The gate 5 is only subjected to pressure from the sealing pipes 3 along their axial direction. This avoids frictional forces perpendicular to the axial direction of the sealing pipes 3 between them, providing some margin for sealing. Simultaneously, the compressed elastic element 26 consistently applies downward pressure to the closed gate 5, enhancing its fixing effect.

[0060] Reference Figure 3 , Figure 4 and Figure 8 Two connecting plates 51 are provided on the arc surface of the gate 5, and the gate is located between the two connecting plates 51. Rollers 52 are rotatably provided on the connecting plates 51. The rollers 52 abut against the side walls of the upper and lower housings 12 to improve the stability of the gate 5 movement and reduce the friction between the gate 5 and the housing 1.

[0061] Reference Figure 1 and Figure 2 The upper housing 11 is provided with a detection component 6, which includes a limiting tube 61, a sliding member 62, an elastic member 63, and a sliding limiting member 65. The limiting tube 61 is fixedly mounted on the upper housing 11 and communicates with the interior of the upper housing 11. A guide block 64 is fixedly mounted inside the limiting tube 61, and the guide block 64 has a limiting hole. The sliding member 62 is slidably mounted in the limiting hole. The sliding member 62 includes a piston plate 621, which is adapted to the limiting tube 61 and slides in a sealing manner with the limiting tube 61. The elastic member 63 is disposed between the piston plate 621 and the guide block 64, and the elastic force of the elastic member 63 causes the piston plate 621 to slide into the upper housing 11.

[0062] When the gate valve is closed, if the piston plate 621 moves a certain amount towards the upper housing 11 when the sealing pipes 3 on both sides abut against the gate plate 5, it indicates that there is a leak in the seal of the housing 1, or a leak in the seal between the sealing pipe 3 and the gate plate 5 on the gas output side of the gate valve. This causes the gas pressure inside the housing 1 to decrease, and the pressure of the gas pressure inside the housing 1 on the piston plate 621 is less than the elastic force of the second elastic element 63 on the piston plate 621. Conversely, if the piston plate 621 moves away from the upper housing 11, it indicates that there is a leak in the seal between the sealing pipe 3 and the gate plate 5 at the gas pipeline input end of the gate valve. This causes gas to enter the housing 1, resulting in an increase in the gas pressure inside the housing 1. This increases the pressure, overcoming the elastic force of the second elastic element 63, and causing the piston plate 621 to move away from the upper housing 11.

[0063] When the gate valve is in the open state, if the piston plate 621 moves towards the upper housing 11, it indicates that there is an air leak in the seal of the housing 1. If the piston plate 621 moves away from the upper housing 11, it indicates that there is a problem with the seal between the two sealing pipes 3.

[0064] Reference Figure 1 and Figure 2The sliding component 62 includes a connecting rod 622 and a stop plate 623. The connecting rod 622 is adapted to a limiting hole on the guide block 64. The connecting rod 622 passes through the limiting hole on the guide block 64 and one end is fixedly connected to the piston plate 621. The end of the connecting rod 622 away from the piston plate 621 is fixedly connected to the stop plate 623. The connecting rod 622 is engaged with the keyway of the guide block 64, meaning that the connecting rod 622 can only slide along the axial direction of the limiting tube 61. The area of ​​the stop plate 623 is larger than the area of ​​the limiting hole, meaning that the stop plate 623 cannot pass through the limiting hole. The position of the piston plate 621 is adjusted by the stop plate 623, thus adjusting the initial position of the piston plate 621.

[0065] Reference Figure 1 and Figure 2 A sliding limit member 65 is slidably provided on the guide block 64. The sliding limit member 65 can move between the stop plate 623 and the guide block 64, that is, the sliding limit member abuts against the stop plate 623 to restrict the position of the sliding member 62. A fastener is provided on the sliding limit member 65 to fix the position of the sliding limit member 65 on the guide block 64.

[0066] During the switching process between the closed and open states of the gate valve, the stop plate 623 can be manually pulled to move away from the upper housing 11, and then the sliding limit member 65 can be moved between the stop plate 623 and the guide block 64 and fixed by the fasteners on the sliding limit member 65. This prevents the change in air pressure inside the gate valve from interfering with the position of the piston plate 621 when the gate valve is switching states. At the same time, when the gate valve is in each closed and open state, the piston plate 621 is kept in the initial designated position. By judging the change of the piston plate 621 relative to the initial position, it can be determined whether the gate valve is leaking air.

[0067] Reference Figure 1 , Figure 5 and Figure 6 The upper housing 11 includes a protective tube 111, which is fixedly mounted on the upper housing 11. The protective tube 111 is hollow, and a drive handwheel 21 is rotatably mounted on the protective tube 111. The drive sleeve 22 and drive rod 23 are both located inside the protective tube 111, and a drive limiting block 25 is fixedly mounted on the inner wall of the protective tube 111. The protective tube 111 is designed to protect the drive sleeve 22 and drive rod 23, preventing them from being exposed to air for extended periods, which could affect their transmission performance and service life.

[0068] Reference Figure 5 , Figure 8 and Figure 9A gate limiting plate 122 is fixedly installed on the side of the lower housing 12 to limit the position of the gate 5 within the lower housing 12. When the connecting plate 51 on the gate 5 abuts against the gate limiting plate 122, the gate 5 stops moving, i.e., the gate 5 is in the closed position of the gate valve. An arc-shaped impurity receiving cavity 123 is provided below the lower housing 12, i.e., the space formed by the bottom of the gate 5 and the bottom surface of the lower housing 12 when the gate valve is in the closed state. An ash discharge port 124 is provided at the bottom of the lower housing 12, which communicates with the impurity receiving cavity 123 and is located at the lowest point of the impurity receiving cavity 123. A detachable sealing device is provided at the ash discharge port 124 on the bottom outer side of the lower housing 12.

[0069] When the gate valve switches from the closed state to the open state and then to the fully open state, the gate 5 moves upward into the space inside the upper shell 11, and the space in the lower shell 12 becomes larger. When the gas flows through, the flow velocity slows down in this relatively spacious space. Solid particles in the gas, such as rust, dust, and tar condensate from the pipeline system, are easily deposited at the bottom of the lower shell 12, i.e., in the impurity receiving cavity 123, due to gravity or the reduced flow velocity. They then concentrate at the ash discharge port 124. When a certain amount has accumulated, the sealing device at the ash discharge port 124 is opened to clean out the impurities inside.

[0070] The gate 5 is limited by the setting of the gate plate 5 and the impurity accommodating cavity 123 so that the gate plate 5 will not directly contact the lower housing 12, preventing the accumulation of dust at the bottom of the lower housing 12 from affecting the downward position of the gate plate 5 and thus affecting the sealing effect of the gate valve.

[0071] Reference Figure 5 and Figure 8 A cleaning pipe 125 is provided on the side of the lower housing 12. The cleaning pipe 125 penetrates the side wall of the lower housing 12 and communicates with the space inside the lower housing 12. The cleaning pipe 125 is located above the impurity receiving cavity 123. A detachable sealing plate is provided at the cleaning pipe 125. The sealing plate is connected to the cleaning pipe 125 by bolts. In this embodiment, there are two cleaning ports, which are distributed on both sides of the lower housing 12, that is, on both sides of the arc surface of the gate 5.

[0072] When the gate valve has been used for a certain period of time, and the impurities in the impurity receiving cavity 123 cannot be discharged smoothly by relying solely on the ash discharge port 124, the cleaning pipe 125 and the ash discharge port 124 are opened at the same time, and gas or liquid is introduced from the cleaning pipe 125 to flush the impurities in the impurity receiving cavity 123. The impurities are then discharged into the housing 1 through the ash discharge port 124, and then the cleaning pipe 125 and the ash discharge port 124 are resealed.

[0073] The implementation principle of this invention is as follows:

[0074] When the gate valve is closed, the gate 5 is inside the lower housing 12, and the gate 5 forms a seal with the sealing pipes 3 on both sides, cutting off the flow of gas in the gas pipeline. When the gate valve needs to be opened, the drive handwheel 21 is manually turned, which drives the gate connecting frame 24 to rise through the drive rod 23. The gate connecting frame 24 drives the rack plate 1 41 and rack plate 2 42 to rise. The rack plate 1 41 and rack plate 2 42 respectively mesh with the transmission gear 431, and through the two gear components 43, they drive the two sealing pipes 3 away from or towards the gate 5. That is, when the rack plate 1 41 meshes with the transmission gear 431, the two sealing pipes 3 move away from the gate 5. Then, after the gate 5 leaves the sealing area, the rack plate 2 42 meshes with the transmission gear 431. At this time, the sealing pipes 3 on both sides approach each other until they abut each other. At this time, the two sealing pipes 3 form a connection with the gas pipeline and form a sealing effect on the gas pipeline, forming a double seal with the gate valve housing 1.

[0075] When the gate valve needs to be closed, the drive handwheel 21 is rotated in the opposite direction, which drives the gate connecting frame 24 to descend via the drive rod 23. As the gate connecting frame 24 descends, rack plate 22 and rack plate 41 respectively engage with the transmission gear 431 in sequence. This first moves the sealing pipes 3 on both sides away from each other to make way for the gate 5 to descend. Then, when the gate 5 moves to the designated position, the gate connecting frame 24 continues to move downward relative to the gate 5. At the same time, rack plate 41 engages with the transmission gear 431, causing the sealing pipes 3 on both sides to move closer to the gate 5 until they abut against the gate 5, thus sealing the gas pipeline.

[0076] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A fall-prevention gate valve for gas pipelines, comprising a housing and a gate that slides up and down within the housing to control the opening and closing of the gate valve, characterized in that, The housing contains a sealing tube, a sealing drive assembly, and a gate drive assembly that moves the gate up and down. There are two sealing tubes, which are slidably disposed on both sides of the gate and both of them slide toward the gate. The sealing drive assembly is connected to the sealing tubes to adjust the position of the sealing tubes. When the gate valve is opened, the gate moves upward, and the sealing drive assembly drives the sealing tube away from the gate. After the gate moves out from between the sealing tubes, the sealing drive assembly drives the two sealing tubes to abut against each other. When the gate valve is closed, the gate moves downward and the sealing drive assembly controls the two sealing tubes to move away from each other. When the gate moves to the closed position of the gate valve, the sealing drive assembly controls the two sealing tubes to come into contact with the gate. The sealing drive assembly includes a first rack plate, a second rack plate, and a gear component. The first rack plate and the second rack plate are fixedly mounted on the gate drive assembly. The gear component is coaxially mounted with the sealing tube and helically engaged. The first rack plate and the second rack plate mesh with the gear component for transmission, and the gear component is positioned between the first rack plate and the second rack plate. When the gate valve is opened, the gate drive assembly drives the gate to move upward. The first rack plate and the second rack plate are arranged along the direction of the gate's movement so that the first rack plate and the second rack plate engage with the gear component successively and drive the gear component to rotate in opposite directions. When the first rack plate engages with the gear component, the two sealing tubes move away from the gate. When the second rack plate engages with the gear component so that the gate moves out from between the sealing tubes, the two sealing tubes approach each other and abut against each other to form a seal. The gate drive assembly includes a drive handwheel, a drive sleeve fixedly mounted on the drive handwheel, a drive rod, and a gate connecting frame. The drive handwheel is rotatably mounted on the housing. The drive rod is screwed into the drive sleeve. The gate is fixedly mounted on the drive rod via the gate connecting frame. The drive rod is slidably mounted on the housing. An elastic element is provided between the gate connecting frame and the gate to connect the two.

2. The anti-fall gate valve for gas pipelines according to claim 1, characterized in that, A detection assembly is provided on the housing. The detection assembly includes a limiting tube, an elastic element II, a sliding element, and a guide block. The limiting tube is fixedly installed on the housing, the guide block is fixedly installed inside the limiting tube, the sliding element is slidably installed on the guide block, and the sliding element is slidably sealed with the limiting tube. An elastic element II is provided between the sliding element and the guide block.

3. A fall-prevention gate valve for gas pipelines according to claim 2, characterized in that, The sliding component includes a piston plate, a connecting rod, and a stop plate. The guide block is provided with a through hole that matches the connecting rod. The connecting rod is slidably disposed in the through hole. The piston plate and the stop plate are respectively fixedly disposed at both ends of the connecting rod. The area of ​​the stop plate is larger than the cross-sectional area of ​​the connecting rod so that the stop plate is always on the side of the guide block away from the elastic component.

4. A fall-prevention gate valve for gas pipelines according to claim 3, characterized in that, A sliding limit element is slidably installed on the guide block. When the gate valve is opened and closed, the sliding limit element slides between the stop plate and the guide block. The sliding limit element cooperates with the elastic element to make the sliding limit element abut against the stop plate, thereby limiting the position of the stop plate relative to the guide block.

5. A fall-prevention gate valve for gas pipelines according to claim 1, characterized in that, Multiple rollers are evenly arranged on the gate plate, and the rollers are rotated on the gate plate and abut against the inner wall of the housing.

6. A fall-prevention gate valve for gas pipelines according to claim 1, characterized in that, An impurity receiving cavity is provided at the bottom of the housing, and a gate limiting plate is fixedly installed on the side wall of the housing. The gate limiting plate abuts against the gate when the gate descends, limiting the gate to the lowest position inside the housing. The space between the gate and the housing is the impurity receiving cavity.

7. A fall-prevention gate valve for a gas pipeline according to claim 6, characterized in that, A ash discharge port is provided at the bottom of the shell, which penetrates the shell and communicates with the impurity receiving cavity. A cleaning pipe is provided on the shell, which penetrates the shell and communicates with the inside of the shell. The cleaning pipe is located above the impurity receiving cavity.

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