An embedded safety relief device and a liquefied gas tank

Abstract

This invention belongs to the technical field of pressure vessels, specifically disclosing an embedded safety relief device and a liquefied gas tank. The safety relief device includes a cylinder and a valve stem fitted inside the cylinder. A mounting platform extends circumferentially from the top of the cylinder. A valve cover is fixedly connected to the mounting platform in an overlapping manner. A valve stem movable port is located at the center of the valve cover. An L-shaped sealing gasket overlaps the valve stem movable port, with its end engaged with the outer circumference of the top of the valve stem. A groove is formed on the inner circumference of the top of the valve stem, and a sealing ring is embedded in the groove. A valve disc is sealed to the top of the valve stem through the sealing ring and the L-shaped sealing gasket. This invention provides fire resistance, avoids the risk of damage due to the liquefied gas tank tipping over, improves safety, enhances sealing performance, avoids the risk of serious safety accidents due to high internal pressure, and ensures safe storage and transportation.

Description

Technical Field

[0001] This invention belongs to the technical field of pressure vessels, specifically relating to an embedded safety relief device and a liquefied gas tank. Background Technology

[0002] A pressure vessel is a sealed device that holds gas or liquid under pressure. Based on their operating principle in the production process, pressure vessels are classified into reaction pressure vessels, heat exchange pressure vessels, separation pressure vessels, and storage pressure vessels. Liquefied gas tanks belong to the category of storage pressure vessels. Storage pressure vessels are generally used to store flammable, explosive, and volatile media. Because liquefied gas tanks are highly susceptible to changes in ambient temperature, pressure exceeding limits is prone to occur during loading and unloading. To ensure the safety of loading and unloading, safety pressure relief devices are required. Currently, most safety pressure relief devices are externally installed on the liquefied gas tanks. This method has poor sealing performance, making the liquefied gas tanks highly susceptible to gas or liquid leaks during transportation due to road conditions and ambient temperature, potentially leading to serious safety accidents.

[0003] Currently, built-in safety shut-off valve devices exist to ensure safety. For example, Chinese Patent Publication No. CN103453169A, published on December 18, 2013, discloses a built-in safety shut-off valve device for oil storage circuits. The document states that it "includes a shut-off device and a pressure relief device. The shut-off device consists of a plunger, a steel column, a controller, a spring, a spring compression device, and the shut-off valve pipe wall; the plunger is installed inside the shut-off valve pipe wall, forming the shut-off valve body; a pressure relief device is provided inside the plunger, consisting of a pressure relief pipe, a steel wire, a spring, and a piston." This prior art releases the spring's potential energy through the controller, pushing the plunger forward to cut off the pipeline. While this reduces the destructive force of a disaster on the oil storage circuit, this prior art safety shut-off valve device only performs a shut-off function and cannot release internal pressure. This makes it highly susceptible to increased internal pressure during a fire, potentially leading to more serious safety accidents. Furthermore, this prior art has poor sealing performance, easily causing leaks, and is not suitable for liquefied gas tanks. Therefore, a new technical solution is needed to address these technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide an embedded safety relief device and a liquefied gas tank to solve the problems of the existing built-in safety shut-off valve devices mentioned in the background art, which only have a shut-off function and cannot release internal pressure. This makes it easy for the internal pressure to increase and cause more serious safety accidents in the event of a fire. In addition, the poor sealing performance makes it easy to cause leakage, and it is not suitable for liquefied gas tanks.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an embedded safety relief device, comprising a cylinder and a valve stem fitted inside the cylinder, wherein a mounting platform is provided extending outward from the top of the cylinder, a valve cover is fixedly connected to the mounting platform in an overlapping manner, a valve stem movable port is provided at the center of the valve cover, an L-shaped sealing gasket is provided overlappingly on the valve stem movable port, the end of the L-shaped sealing gasket is engaged with the outer circumference of the top of the valve stem, a groove is provided on the inner circumference of the top of the valve stem, a sealing ring is embedded in the groove, a valve disc is sealed and connected to the top of the valve stem through the sealing ring and the L-shaped sealing gasket, a dust cover is provided on the top of the valve disc, and the dust cover is installed on the outer circumference of the valve stem movable port of the valve cover.

[0006] Furthermore, the mounting platform and the valve cover are configured as a disc structure with the same center. The diameter of the valve cover is equal to the diameter of the mounting platform. The valve cover is divided into upper and lower layers. A lifting ring is embedded in the top circumference of the upper valve cover. A horizontal threaded hole is opened on the outer circumference between the upper and lower valve covers. A vertical threaded hole is opened in the vertical direction of the horizontal threaded hole. The vertical threaded hole is opened in the circumference of the upper valve cover. A pressure gauge or plug is threaded into both the horizontal and vertical threaded holes.

[0007] Furthermore, the lower valve cover is fixedly connected to the mounting platform in an overlapping manner. A sealing gasket is provided between the upper inner circumference of the mounting platform and the lower inner circumference of the lower valve cover. The upper valve cover extends from the outer circumference of the lower valve cover to the valve stem movable port and overlaps the top outer circumference of the valve stem. A valve core is fixedly provided in the inner middle of the valve stem. The end of the valve core passes through the inside of the valve stem to the outside of the valve stem and extends to the outside of the valve stem movable port.

[0008] Furthermore, the valve core has a support platform on its outer circumference that is sealed and connected to the valve disc, and a valve core rod on its inner circumference. The top of the valve core rod is threaded with a nut and a lock nut. The bottom of the nut abuts against the top of the valve disc, the top of the nut abuts against the inner wall of the top of the dust cover, and the outer wall of the top of the dust cover abuts against the bottom of the lock nut. The dust cover is locked to the valve disc by the lock nut and the lock nut. The outer circumference of the dust cover overlaps with the inner circumference of the upper valve cover, and the boss and the dust cover form a valve disc sealing cavity.

[0009] Furthermore, a guide sleeve is threaded onto the outer wall of the valve stem, and a spring is elastically connected to the upper part of the guide sleeve. The spring is fitted between the valve stem and the cylinder, with the upper end of the spring elastically connected to the bottom of the upper valve cover and the upper side of the spring contacting the inner circular surface of the lower valve cover. The guide sleeve is slidably connected to the inner wall of the cylinder via the spring. A flange is fixedly connected to the bottom of the cylinder, and a rupture disc is clamped between the flange and the cylinder. Several anti-loosening plates are clamped at the bottom of the flange by bolts, with the two ends of the anti-loosening plates protruding and distributed circumferentially at the bottom of the flange.

[0010] In addition to the above technical solutions, there are also liquefied gas tanks with this embedded safety relief device.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] 1. This invention employs a dual sealing design of a sealing ring and an L-shaped sealing gasket, ensuring a tighter fit between the valve stem and valve disc. This effectively prevents the risk of gas or liquid leakage during the transportation of liquefied gas cylinders, enhancing the sealing effect of the safety relief device and thus providing it with fire-resistant functionality. By extending the mounting platform circumferentially outside the cylinder, the safety relief device can be embedded inside the liquefied gas cylinder, effectively reducing the size of the protective frame and mitigating the risk of damage due to cylinder tipping. This also improves the safety of the liquefied gas cylinder. Covering the top of the valve disc with a dust cover significantly enhances its sealing effect, effectively reducing the impact of environmental dust on the valve disc. The combination of the valve disc and the L-shaped sealing gasket allows the liquefied gas cylinder to release internal pressure in the event of a fire, effectively preventing the risk of serious safety accidents caused by high internal pressure and ensuring the safety of liquefied gas cylinder storage and transportation.

[0013] 2. This invention employs a sealing gasket between the mounting platform and the lower valve cover, which significantly improves the sealing performance of the valve stem. This effectively avoids the risk of gas or liquid leakage during the transportation of liquefied gas tanks, enhancing the sealing effect of the safety relief device and thus giving it fire-resistant properties. By creating horizontal and vertical threaded holes on the outer circumference of the upper and lower valve covers, respectively, the safety relief device not only possesses sealing performance but also the function of monitoring internal pressure, effectively improving its safety and practicality.

[0014] 3. This invention significantly improves the sealing effect of the valve disc by attaching a dust cover to the inner circumferential protrusion of the upper valve cover, effectively reducing the impact of dust in the environment on the valve disc. The locking function of the lock nut and nut makes the installation of the dust cover more convenient and quick. The spring slides the guide sleeve on the inner wall of the cylinder, making the pressure relief of this safety relief device safer and more reliable, effectively improving the safety of the liquefied gas tank.

[0015] 4. This invention utilizes the warping effect of the two ends of the anti-loosening plate to effectively improve the protective effect of the rupture disc, avoiding the problem of the rupture disc failing due to the loosening of the bottom bolts of the flange caused by vibration. This allows the liquefied gas tank to release internal pressure in the event of a fire, effectively avoiding the risk of serious safety accidents caused by high internal pressure, and ensuring the safety of liquefied gas tank storage and transportation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of the safety relief device of the present invention;

[0018] Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure;

[0019] Figure 4 This is a structural cross-sectional schematic diagram of the valve stem and valve disc in the sealed state of the present invention (including valve cover, dust cover, lock nut and nut).

[0020] Figure 5 This is a schematic cross-sectional view of the spring distribution structure of the present invention.

[0021] The components are as follows: 1. Cylinder; 101. Liquefied gas tank; 102. Frame; 2. Valve stem; 3. Mounting platform; 4. Valve cover; 401. Upper valve cover; 4011. Boss; 402. Lower valve cover; 5. Valve stem movable port; 6. L-shaped sealing gasket; 7. Groove; 8. Sealing ring; 9. Valve disc; 10. Dust cover; 11. Flange; 12. Rupture disc; 13. Anti-loosening plate; 14. Lifting ring; 15. Horizontal threaded hole; 16. Vertical threaded hole; 17. Plug; 18. Guide sleeve; 19. Spring; 20. Sealing gasket; 21. Valve core; 211. Valve core rod; 22. Support platform; 23. Nut; 24. Lock nut; 25. Bolt. Detailed Implementation

[0022] The following examples are used to further illustrate the content of the present invention and do not limit the application of the present invention.

[0023] Example 1:

[0024] Please see Figures 1-5An embedded safety relief device includes a cylinder 1 and a valve stem 2 fitted inside the cylinder 1. A mounting platform 3 extends circumferentially from the top of the cylinder 1 for internal installation into a liquefied gas tank 101. A protective frame 102 is provided on the exterior of the liquefied gas tank 101. A valve cover 4 for sealing the valve stem 2 is fixedly connected to the mounting platform 3 in an overlapping manner. A valve stem movement port 5 for the valve stem 2 is located at the center of the valve cover 4. An L-shaped sealing element is overlapped on the valve stem movement port 5. The L-shaped sealing gasket 6 has its end engaged with the outer periphery of the top of the valve stem 2. The inner periphery of the top of the valve stem 2 has a groove 7 for installing the sealing ring 8. The sealing ring 8 is embedded in the groove 7 for sealing. The top of the valve stem 2 is sealed and connected to the valve disc 9 for opening and closing the valve stem 2 through the sealing ring 8 and the L-shaped sealing gasket 6. The top of the valve disc 9 is covered with a dust cover 10 to prevent environmental dust from affecting the valve disc 9. The dust cover 10 is installed on the outer periphery of the valve stem movable opening 5 of the valve cover 4.

[0025] Please see Figures 2-3 The bottom of the cylinder 1 is fixedly connected to a flange 11 for installing a rupture disc 12. A rupture disc 12 for releasing the internal pressure of the liquefied gas tank 101 is clamped between the flange 11 and the cylinder 1. The bottom of the flange 11 is clamped by bolts 25 with several anti-loosening plates 13 for preventing the rupture disc 12 from failing. The two ends of the anti-loosening plates 13 are evenly distributed on the circumference of the bottom of the flange 11.

[0026] Please see Figures 3-5 The mounting platform 3 and the valve cover 4 are set as a disc structure with the same center. The diameter of the valve cover 4 is equal to the diameter of the mounting platform 3. The valve cover 4 is divided into upper and lower layers. The top circumference of the upper valve cover 401 is embedded with a lifting ring 14 for installation. The outer circular surface between the upper valve cover 401 and the lower valve cover 402 is provided with a horizontal threaded hole 15 for horizontal connection of equipment. The vertical threaded hole 15 is provided with a vertical threaded hole 16 for vertical connection of equipment. The vertical threaded hole 16 is opened in the circumference of the upper valve cover 401. The horizontal threaded hole 15 and the vertical threaded hole 16 are both threaded with a pressure gauge for monitoring pressure or a plug 17 for sealing.

[0027] A guide sleeve 18 for guiding the valve stem 2 is threaded onto the outer wall of the valve stem 2. A spring 19 for ensuring the smooth rise of the valve stem 2 is elastically connected to the upper part of the guide sleeve 18. The spring 19 is fitted between the valve stem 2 and the cylinder 1. The upper end of the spring 19 is elastically connected to the bottom of the upper valve cover 401, and the upper side of the spring 19 is connected to the inner circular surface of the lower valve cover 402. The guide sleeve 18 is slidably connected to the inner wall of the cylinder 1 through the spring 19.

[0028] The lower valve cover 402 is fixedly connected to the mounting platform 3 in an overlapping manner. A sealing gasket 20 for sealing the valve stem 2 is clamped between the upper inner circumference of the mounting platform 3 and the lower inner circumference of the lower valve cover 402. The upper valve cover 401 extends from the outer circular surface of the lower valve cover 402 to the valve stem movable port 5 and overlaps the top outer circumference of the valve stem 2. A valve core 21 for controlling the valve stem 2 is fixedly installed in the inner middle of the valve stem 2. The end of the valve core 21 passes through the inside of the valve stem 2 to the outside of the valve stem 2 and extends to the outside of the valve stem movable port 5. A support platform 22 for installing the valve disc 9 is provided on the outer circumference of the valve core 21. The support platform 22 is sealed to the valve disc 9 through the sealing ring 8 and the L-shaped sealing gasket 6. A valve core rod 211 is provided on the inner circumference of the valve core 21. A nut 23 and a lock nut 24 for fixing the dust cover 10 are threadedly connected to the top of the valve core rod 211.

[0029] The bottom of nut 23 abuts against the top of valve disc 9, the top of nut 23 abuts against the inner wall of the top of dust cover 10, and the outer wall of the top of dust cover 10 abuts against the bottom of lock nut 24. Dust cover 10 is locked to valve disc 9 by lock nut 24 and nut 23. The outer circumference of dust cover 10 overlaps the inner circumference of the boss 4011 of upper valve cover 401. Boss 4011 and dust cover 10 form valve disc sealing cavity.

[0030] The working principle and usage process of this invention are as follows: Figures 1-5 As shown, once the safety relief device is completed, it only needs to be embedded into the upper part of the liquefied gas tank 101 (e.g., Figure 1As shown), this allows the liquefied gas tank 101 to not only have sealing performance but also fireproof function. Specifically: First, the valve stem 2 with valve core 21 inside is fitted into the cylinder 1. Then, a guide sleeve 18 is installed on the outer wall of the valve stem 2. Using the support of the guide sleeve 18, the spring 19 is fitted between the valve stem 2 and the cylinder 1. Then, the valve cover 4 with a lifting ring 14 and horizontal threaded hole 15 and vertical threaded hole 16 is placed on top of the spring 19, so that the upper valve cover 401 is elastically connected to the upper end of the spring 19, and the lower valve cover 402 is elastically connected to the upper side of the spring 19. At the same time, the lower valve cover 402 is fixed to the mounting platform 3 extending circumferentially on the outer side of the cylinder 1. Then, the valve stem movable port 5, support platform 22 and valve disc 9 at the center of the valve cover 4 are sealed by the sealing ring 8 and L-shaped sealing gasket 6 to form a closed space. Then, the dust cover 10 is sealed by the nut 23 and lock. The mother 24 is fixed to the top of the valve core rod 211, so that the dust cover 10 and the inner circumferential boss 4011 of the upper valve cover 401 form a valve disc sealing cavity, which can effectively reduce the impact of dust in the environment on the valve disc 9. Then, the rupture disc 12 is clamped to the bottom of the cylinder 1 through the flange 11. Then, the anti-loosening plate 13 is evenly clamped and installed on the bottom circumferential of the flange 11 by bolts 25, and the two ends of the anti-loosening plate 13 are raised, which can effectively prevent the rupture disc 12 from failing due to the loosening of the bolts 25 at the bottom of the flange 11 by vibration. That is, the installation of the cylinder 1 is completed. Then, the cylinder 1 with an internal enclosed space is embedded into the upper part of the liquefied gas tank 101 through the mounting platform 3 extending on the outer circumference of the cylinder 1. Finally, a protective frame 102 is erected on the outside of the liquefied gas tank 101, which completes the installation of the safety relief device.

[0031] When the internal pressure of the liquefied gas tank 101 rises due to a fire and reaches the discharge requirements, the pressure inside the liquefied gas tank 101 will cause the rupture disc 12 to rupture. After the rupture disc 12 ruptures, the pressure will act on the valve disc 9, causing the valve disc 9 to move upward, thereby causing the L-shaped sealing gasket 6 to disengage from the overlapping surface on the valve stem movable port 5. At this time, the pressure inside the liquefied gas tank 101 will be rapidly discharged to the outside, that is, the safety relief device will be activated, thereby ensuring the safety of the liquefied gas tank 101. When the pressure inside the liquefied gas tank 101 decreases, the valve disc 9 will move downward under the force of the spring 19, causing the L-shaped sealing gasket 6 to overlap and seal with the valve stem movable port 5 again, that is, the safety relief device will be closed.

[0032] Example 2:

[0033] Please see Figures 1-5 As another objective of the present invention, a liquefied gas tank is provided, wherein the liquefied gas tank is provided with the above-described embedded safety relief device. Therefore, the liquefied gas tank can obtain any of the beneficial effects of the embedded safety relief device described above, which will not be repeated here.

Claims

1. An embedded safety relief device, comprising a cylinder and a valve stem fitted inside the cylinder, characterized in that, A mounting platform extends circumferentially from the top of the cylinder. A valve cover is fixedly and overlappingly connected to the mounting platform. The valve cover has two layers, upper and lower. The lower valve cover is fixedly and overlappingly connected to the mounting platform. A sealing gasket is fitted between the upper inner circumference of the mounting platform and the lower inner circumference of the lower valve cover. The upper valve cover extends from the outer surface of the lower valve cover to the valve stem opening and overlaps the top outer circumference of the valve stem. A valve stem opening is located at the center of the valve cover. An L-shaped sealing gasket overlaps the valve stem opening, and its end is fitted onto the top outer circumference of the valve stem. A valve core is fixedly installed in the inner center of the valve stem. The end of the valve core passes through the inside of the valve stem to the outside and extends to the outside of the valve stem opening. The bottom of the nut abuts against the top of the valve disc, and the top of the nut abuts against the inner wall of the top of the dust cover. The outer wall of the top of the dust cover abuts against the lock nut. The bottom abutment connection is achieved. The dust cover is locked to the valve disc via a lock nut and a locking nut. The outer circumference of the valve core has a support platform that seals with the valve disc. The inner circumference of the valve core has a valve core rod. The top of the valve core rod is threaded with a nut and a lock nut. The inner circumference of the top of the valve core rod has a groove with a sealing ring embedded in it. The top of the valve core rod is sealed to the valve disc via the sealing ring and an L-shaped sealing gasket. The top of the valve disc is covered by a dust cover. The dust cover is installed on the outer circumference of the valve stem's movable opening on the valve cover. The outer circumference of the dust cover overlaps with the inner circumference of the upper valve cover's boss. The boss and the dust cover form a valve disc sealing cavity. The bottom of the cylinder is fixedly connected to a flange. A rupture disc is clamped between the flange and the cylinder. The bottom of the flange is clamped with bolts holding several anti-loosening plates. The two ends of the anti-loosening plates are raised and distributed circumferentially on the bottom of the flange.

2. The embedded safety relief device according to claim 1, characterized in that, The mounting platform and the valve cover are configured as a disc structure with the same center, and the diameter of the valve cover is equal to the diameter of the mounting platform.

3. The embedded safety relief device according to claim 1, characterized in that, A guide sleeve is threaded onto the outer wall of the valve stem. A spring is elastically connected to the upper part of the guide sleeve. The spring is fitted between the valve stem and the cylinder. The upper end of the spring is elastically connected to the bottom of the upper valve cover. The upper side of the spring is connected to the inner circular surface of the lower valve cover. The guide sleeve is slidably connected to the inner wall of the cylinder through the spring.

4. The embedded safety relief device according to claim 3, characterized in that, A lifting ring is embedded in the top circumference of the upper valve cover. A horizontal threaded hole is opened on the outer circumference between the upper and lower valve covers. A vertical threaded hole is opened in the vertical direction of the horizontal threaded hole. The vertical threaded hole is opened in the circumference of the upper valve cover. A pressure gauge or plug is threaded into both the horizontal and vertical threaded holes.

5. A liquefied gas tank, characterized in that, Includes an embedded safety relief device as described in any one of claims 1-4.

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