Water hammer arrestor with rotating wheel

Abstract

This invention discloses a water hammer-resistant gate valve with a rotary wheel, relating to the field of valve technology. It includes a valve body with an inlet and an outlet, connected by a central cavity. The central cavity is equipped with a water hammer-resistant pressure-reducing device to prevent water hammer damage to the valve when it is closed. The outlet has a drain port and a drain cavity, connected to the outlet and central cavity. The water hammer-resistant pressure-reducing device includes a rotary disc and a drive mechanism. The rotary disc has several slots, within which rotating plates are movably disposed. The valve stem is eccentrically positioned. When water hammer occurs, the drive mechanism moves the rotary disc downwards, causing the medium in the outlet to push the disc to rotate and eliminate the water hammer. This invention effectively reduces the impact damage of water hammer on the valve, relieves pressure on the return medium, and extends its service life.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and specifically to a gate valve with a rotary wheel for preventing water hammer. Background Technology

[0002] A gate valve, also known as a stop valve, is a type of forced-seal valve. Due to its low friction between the sealing surfaces during opening and closing, it is relatively durable, has a small opening height, is easy to manufacture, and is convenient to maintain. It is suitable for both low and medium pressures as well as high pressures, making it one of the most widely used valve types. The opening and closing process of a gate valve is as follows: When the valve is in the closed state, rotating the wrench clockwise rotates the valve stem clockwise. Because the upper part of the valve stem is threadedly connected to the sleeve, the valve stem moves the valve disc upwards as it rotates, causing the valve disc sealing surface to disengage from the valve seat sealing surface, connecting the inlet and outlet, thus opening the valve. Conversely, rotating counterclockwise moves the valve stem downwards, causing the valve disc sealing surface to press against the valve seat sealing surface, isolating the inlet and outlet, and closing the valve. As a crucial component of pipelines, gate valves perform functions such as media transport, shut-off, and regulation, making them one of the most important shut-off valves, playing a vital role in aerospace, petrochemical, and power industries.

[0003] Existing gate valves are prone to backflow of the medium on the outlet side when closed, causing water hammer and potentially damaging the valve. Therefore, there is a need for a gate valve that can resist water hammer. For example, Chinese invention patent CN110671502B discloses a water hammer resistant gate valve. It uses a water hammer resistant device between the valve body and the valve plate. The water hammer resistant device includes a water hammer resistant sliding member and a compression spring. The water hammer resistant device uses the sliding of the water hammer resistant sliding member to press against the compression spring, thereby balancing the water pressure with the pressure of the compression spring to achieve water hammer resistance. However, this structure uses a corresponding water hammer resistant device to counteract the pressure of the backflow medium, lacking pressure relief for the backflow medium. It is prone to damage after long-term use, affecting its service life. Summary of the Invention

[0004] To address the problem in existing technologies that when the shut-off valve is closed, the medium on the outlet side is prone to backflow, causing water hammer and failing to mitigate the impact force of the backflow medium, thus easily damaging the valve, this invention provides a water hammer-resistant shut-off valve with a rotary wheel that can effectively reduce the impact damage of water hammer on the valve, relieve pressure on the backflow medium, and extend its service life.

[0005] The technical solution provided by this invention is as follows: A water hammer breaker valve with a rotary wheel includes a valve body with an inlet and an outlet, which are connected by a central cavity. A valve cover is located at the upper end of the valve body, and a valve stem is mounted on the valve cover. The upper end of the valve stem is connected to a handwheel, and the lower end passes through the valve cover and extends into the central cavity of the valve body. A valve disc is located at the lower end of the valve stem. A valve seat is located within the valve body. The valve disc has a first position where it is in contact with the valve seat, isolating the inlet and outlet, and a second position where it is disconnected from the valve seat, connecting the inlet and outlet. The central cavity is equipped with a water hammer pressure-reducing device to prevent water hammer from damaging the valve when it is closed. The outlet has a drain port and a drain cavity, which connects the outlet and the central cavity. The water hammer pressure-reducing device includes a rotary disc and a driving mechanism. The rotary disc has several slots, and rotating plates are movably disposed within the slots. The valve stem is eccentrically positioned. When water hammer occurs, the driving mechanism drives the rotary disc downwards, causing the medium in the outlet to rotate the rotary disc and eliminate the water hammer.

[0006] The driving mechanism includes a driving rod and a driving sleeve. The driving sleeve is sleeved on the valve rod. The turntable is located at the lower end of the driving sleeve. A driving cavity is provided between the drainage cavity and the middle cavity. The driving rod includes a driving head and a rack. The driving head is movably disposed in the driving cavity. The surface of the driving sleeve meshes with the rack.

[0007] The valve body is provided with a cap, and a first drive spring is provided between the drive head and the cap.

[0008] The valve body is provided with a cylinder liner, which together with the valve cover forms a control cavity. The drive sleeve extends into the control cavity from above, and a control plate is provided at the upper end of the drive sleeve. The control plate is movably disposed in the control cavity, and the outer edge of the control plate is threadedly connected to the inner wall of the cylinder liner.

[0009] A return spring is provided between the control board and the lower end of the cylinder liner.

[0010] The drive sleeve is equipped with a positioning block for positioning and fixing the turntable.

[0011] The rotating plate is provided with a dovetail groove, the turntable is provided with a pull rod, the lower end of the pull rod extends into the plate groove, and the lower end of the pull rod is provided with a protrusion that matches the dovetail groove.

[0012] A second driving spring is provided in the slot, with one end of the second driving spring pressing against the rotating plate and the other end pressing against the inner wall of the slot.

[0013] The oral cavity is equipped with an L-shaped drainage tube, which is connected to the drainage port.

[0014] The valve cover is provided with a packing cavity, the valve stem extends through the packing cavity into the valve body, and a pressure cap is provided above the valve cover for pressing the packing in the packing cavity.

[0015] The beneficial effects of this invention are as follows: By providing a water hammer pressure reducing device in the cavity of the gate valve, when the gate valve is closed and water hammer occurs, this water hammer device can effectively reduce the impact damage of water hammer on the valve. By setting the valve shaft eccentrically, the thrust of the outlet return medium acting on one side of the rotating plate is greater than the thrust on the other side of the rotating plate, so that the return medium can push the rotating plate to rotate in the same direction, and the medium enters from one side of the rotating plate and flows out from the other side. The outflowing medium counteracts the return medium on the outlet side, and relieves the pressure of the return medium, which can effectively extend the service life of the valve. Attached Figure Description

[0016] Figure 1 This is a cross-sectional schematic diagram of the shut-off valve according to an embodiment of the present invention; Figure 2 for Figure 1 A schematic cross-sectional view of the EE section; Figure 3 for Figure 2 A schematic diagram of a water hammer event; Figure 4 for Figure 3 DD cross-sectional schematic diagram; Figure 5 for Figure 2 A schematic diagram of the CC cross-section.

[0017] Among them, 1-valve body, 2-inlet cavity, 3-valve seat, 4-valve disc, 5-rotating plate, 6-second drive spring, 7-dovetail groove, 8-pull rod, 9-turntable, 10-positioning block, 11-drive sleeve, 12-cylinder liner, 13-reset spring, 14-control plate, 15-valve cover, 16-bolt, 17-pressure cap, 18-screw sleeve, 19-handwheel, 20-packing, 21-valve stem, 22-middle cavity, 23-rack, 24-cap, 25-first drive spring, 26-drive head, 27-drive cavity, 28-drainage cavity, 29-drainage pipe, 30-outlet cavity, 31-middle cavity centerline, 32-valve stem centerline, 33-plate clamp, 34-plate groove, 35-control cavity, 36-protrusion. Implementation

[0018] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0019] like Figure 1As shown, a rotary valve for preventing water hammer includes a valve body 1. The valve body 1 has an inlet chamber 2 and an outlet chamber 30, which are connected through a central cavity 22. The upper end of the valve body 1 is provided with a valve cover 15, and the valve cover 15 is provided with a valve stem 21. The valve cover 15 is provided with a packing cavity, and the valve stem 21 extends through the packing cavity into the valve body 1. A pressure cap 17 is provided above the valve cover 15 to press the packing 20 in the packing cavity, which fully ensures the sealing between the valve cover 15 and the valve stem 21. The upper end of the valve stem 21 is connected to a handwheel 19. The upper part of the valve stem 21 is provided with a threaded sleeve 18, and the lower end passes through the valve cover 15 and extends into the central cavity 22 of the valve body. The lower end of the valve stem 21 is provided with a valve disc 4, and a valve seat 3 is provided inside the valve body 1.

[0020] The normal opening and closing process of this gate valve is as follows: When the valve is in the closed state, rotating the handwheel 19 clockwise causes the valve stem 21 to rotate clockwise. Since the upper part of the valve stem 21 is connected to the threaded sleeve 18, the valve stem 21 rotates while driving the valve disc 4 upward. The sealing surface of the valve disc 4 separates from the sealing surface of the valve seat, and the inlet chamber 2 connects to the outlet chamber 30, thus opening the valve. Conversely, rotating counterclockwise causes the valve stem 21 to drive the valve disc 4 downward. The sealing surface of the valve disc 4 presses against the sealing surface of the valve seat 3, isolating the inlet chamber 2 from the outlet chamber 30, thus closing the valve.

[0021] like Figure 1-3 As shown, in this embodiment, the valve stem 21 is eccentrically positioned, and the valve stem centerline 32 is offset to the left by a distance A relative to the centerline 31 of the middle cavity. The outlet cavity 30 is provided with a drainage port and a drainage cavity 28. The drainage cavity 28 connects the outlet cavity 30 and the middle cavity 22. The middle cavity 22 is provided with a water hammer pressure reducing device to prevent water hammer from impacting and damaging the valve when the shut-off valve is closed. The water hammer pressure reducing device includes a turntable 9 and a drive mechanism.

[0022] like Figure 4-5As shown, the turntable 9 is evenly provided with 6 clips 33, each clip 33 having a clip groove 34. A rotating plate 5 is movably mounted within each clip groove 34. Specifically, the rotating plate 5 has a dovetail groove 7. The turntable 9 has a pull rod 8, the lower end of which extends into the clip groove 34. The lower end of the pull rod 8 has a protrusion 36 that matches the dovetail groove 7. A second drive spring 6 is located within the clip groove 34, with one end pressing against the rotating plate 5 and the other end pressing against the inner wall of the clip groove 34. The dovetail groove 7 and the protrusion 36 restrict the direction of movement of the rotating plate 5, ensuring that it does not deviate during movement. Because of the eccentric setting of the valve stem 21, the rotating plate 5 on the left side of the rotary table 9 is squeezed and retracted into the plate groove 34, compressing the second drive spring 6. The thrust of the outlet return medium on the right plate clamp and rotating plate is greater than the thrust of the outlet return medium on the left plate clamp and rotating plate. Therefore, the rotary table 9 drives the plate clamp 33 and rotating plate 5 to rotate counterclockwise. The plate clamp 33 and rotating plate 5 drive the return medium to rotate counterclockwise. The medium enters from the right side and flows out from the left side. The medium flowing out from the left side counteracts the return medium on the outlet side, reducing the impact force of the return medium, relieving the pressure of the return medium, thereby eliminating water hammer and reducing the impact damage of the return medium on the valve.

[0023] like Figure 1-3 As shown, the drive mechanism includes a drive rod and a drive sleeve 11. The drive sleeve 11 is fitted onto the valve stem 21. The drive sleeve 11 is provided with a positioning block 10 for positioning and fixing the turntable 9. The turntable 9 is located at the lower end of the drive sleeve 11. A drive cavity 27 is provided between the drainage cavity 28 and the middle cavity 22. The drive rod includes a drive head 26 and a rack 23. The drive head 26 is movably disposed in the drive cavity 27. The surface of the drive sleeve 11 meshes with the rack 23. A cap 24 is provided inside the valve body 1. A first drive spring 25 is provided between the drive head 26 and the cap 24. Further, a cylinder liner 12 is provided inside the valve body 1. The cylinder liner 12 and the valve cover 15 form a control cavity 35. The drive sleeve 11 extends upward into the control cavity 35. A control plate 14 is provided at the upper end of the drive sleeve 11. The control plate 14 is movably disposed in the control cavity 35. A return spring 13 is provided between the control plate 14 and the lower end of the cylinder liner 12.

[0024] When the shut-off valve is closed and the sealing surface of the valve disc 4 presses against the sealing surface of the valve seat 3, the medium in the inlet chamber 2 cannot enter the outlet chamber 30. At this time, if the medium in the outlet chamber 30 flows back and causes water hammer, the medium in the outlet chamber 30 enters the drainage chamber 28 through the drainage hole, pushing the drive rod to the left. The rack 23 drives the drive sleeve 11 to rotate. Since the outer edge of the control plate 14 and the inner wall of the cylinder liner 12 form a threaded connection, the drive sleeve 11 moves downward while rotating. When the drive head 26 moves to the left and compresses the first drive spring 25 to a certain extent, it can no longer be compressed. The rack 23 no longer drives the drive sleeve 11 to rotate, and the drive sleeve 11 can no longer move downward. At the same time, the backflow medium can be depressurized through the turntable 9 to eliminate water hammer. When the water hammer disappears, the medium pressure in the drive chamber 27 drops. Under the combined action of the first drive spring 25 and the return spring 13, the drive head 26 and the rack 23 move to the right, causing the drive sleeve 11 and the control plate 14 to rotate in the opposite direction. The drive sleeve 11 drives the turntable 9, the plate clamp 33 and the rotating plate 5 to move up to the initial position.

[0025] In this embodiment, the outlet 30 is provided with an L-shaped drainage tube 29, which is connected to the drainage port. The drainage tube 29 can predict the occurrence of water hammer in advance, further increasing the pressure reduction effect of the water hammer pressure reducing device.

[0026] The embodiments should not be construed as limiting the present invention, and any non-creative improvements made based on the spirit of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A rotary valve for preventing water hammer, comprising a valve body, wherein the valve body has an inlet and an outlet, the inlet and outlet being connected through a central cavity of the valve body, a valve cover is provided at the upper end of the valve body, a valve stem is provided on the valve cover, the upper end of the valve stem is connected to a handwheel, the lower end of the valve stem passes through the valve cover and extends to the central cavity of the valve body, a valve disc is provided at the lower end of the valve stem, a valve seat is provided inside the valve body, the valve disc having a first position that is in contact with the valve seat and isolates the inlet and outlet, and a second position that is disconnected from the valve seat and connects the inlet and outlet, characterized in that: The middle cavity is equipped with a water hammer pressure reducing device to prevent water hammer from impacting and damaging the valve when the shut-off valve is closed. The outlet cavity is equipped with a drainage port and a drainage cavity. The drainage cavity connects the outlet cavity and the middle cavity. The water hammer pressure reducing device includes a turntable and a drive mechanism. The turntable is equipped with several slots, and rotating plates are movably arranged in the slots. The valve stem is eccentrically arranged. When water hammer occurs, the drive mechanism can drive the turntable to move down and make the medium in the outlet cavity push the turntable to rotate to eliminate water hammer. The driving mechanism includes a driving rod and a driving sleeve. The driving sleeve is sleeved on the valve rod. The turntable is located at the lower end of the driving sleeve. A driving cavity is provided between the drainage cavity and the middle cavity. The driving rod includes a driving head and a rack. The driving head is movably disposed in the driving cavity. The surface of the driving sleeve meshes with the rack.

2. The water hammer stop valve with rotating wheel according to claim 1, characterized in that: The valve body is provided with a cap, and a first drive spring is provided between the drive head and the cap.

3. The water hammer stop valve with rotating wheel according to claim 1, characterized in that: The valve body is provided with a cylinder liner, which together with the valve cover forms a control cavity. The drive sleeve extends into the control cavity from above, and a control plate is provided at the upper end of the drive sleeve. The control plate is movably disposed in the control cavity, and the outer edge of the control plate is threadedly connected to the inner wall of the cylinder liner.

4. A water hammer stop valve with a rotating wheel according to claim 3, characterized in that: A return spring is provided between the control board and the lower end of the cylinder liner.

5. A water hammer stop valve with a rotating wheel according to claim 1, characterized in that: The drive sleeve is equipped with a positioning block for positioning and fixing the turntable.

6. A water hammer stop valve with a rotating wheel according to claim 1, characterized in that: The rotating plate is provided with a dovetail groove, the turntable is provided with a pull rod, the lower end of the pull rod extends into the plate groove, and the lower end of the pull rod is provided with a protrusion that matches the dovetail groove.

7. A rotary valve for preventing water hammer according to claim 1 or 6, characterized in that: A second driving spring is provided in the slot, with one end of the second driving spring pressing against the rotating plate and the other end pressing against the inner wall of the slot.

8. A water hammer stop valve with a rotating wheel according to claim 1, characterized in that: The oral cavity is equipped with an L-shaped drainage tube, which is connected to the drainage port.

9. A water hammer stop valve with a rotating wheel according to claim 1, characterized in that: The valve cover is provided with a packing cavity, the valve stem extends through the packing cavity into the valve body, and a pressure cap is provided above the valve cover for pressing the packing in the packing cavity.

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