Safety valve leakproof device

Abstract

The invention discloses a safety valve leakproof device, belongs to the technical field of pressure vessel protection, and aims to solve the problem of steam waste caused by front leakage of a spring type safety valve. Comprising a shell and a second ejector rod arranged on the shell in a sliding mode, the corrugated pipe body is communicated with a protected container through a pressure taking pipe, the shell is fixed to the safety valve, the axial expansion size of the corrugated pipe body can be changed through the medium pressure in the protected container, and then the pressure taking pipe is controlled to be closed when the medium pressure is smaller than the set pressure of the spring safety valve. The second ejector rod abuts against the safety valve rod, and when the medium pressure reaches the set pressure of the spring safety valve, the second ejector rod is separated from the safety valve rod, so that the spring safety valve can take off smoothly. On the basis that no electric appliance element is added, the spring safety valve can be assisted to achieve zero front leakage of set pressure, the sealing effect is better, the possibility of steam leakage of the safety valve is avoided, more steam waste is avoided, and the operation economic benefits of a power plant are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure vessel protection, and in particular relates to a safety valve anti-leakage device. Background Art

[0002] The spring-loaded safety valve used in traditional pressure vessels is a device that automatically discharges a certain amount of steam with the help of the pressure of the high-temperature and high-pressure steam medium itself when the medium pressure exceeds the design value of the pressure vessel to protect the normal operation of the pressure vessel.

[0003] According to regulations, the set pressure of a spring-loaded safety valve is 1.05 to 1.1 times the working pressure. However, the unit specific pressure generated by the spring force on the valve core sealing surface is small. Generally, the safety valve will leak at 90% of the set pressure, which is called the forward leakage of the safety valve.

[0004] If the protected pressure vessel operates at 90% of the set pressure, the safety valve will continue to leak forward. Long-term leakage will damage the sealing surface of the safety valve and cause the safety valve to fail. In addition, continuous leakage will also cause a large amount of steam to be wasted. Summary of the invention

[0005] The purpose of the present invention is to provide a safety valve anti-leakage device to solve the problem of steam waste caused by forward leakage of a spring-type safety valve. The technical solution adopted by the present invention is as follows:

[0006] A safety valve anti-leakage device, wherein the safety valve is a spring safety valve, the lower opening of the spring safety valve is a medium inlet, and the upper end of the safety valve stem passes through the spring safety valve upward:

[0007] The anti-leakage device comprises a shell, a partition is provided in the middle of the shell, the partition divides the shell into a small chamber located at the left part and a main chamber at the right part, a first sliding sleeve is provided on the partition, a first push rod is slidably matched with the first sliding sleeve, the right end of the first push rod is inserted into the main chamber and connected with the top pressure nut, a jump spring assembly is sleeved on the left part of the first push rod, the jump spring assembly is in the small chamber, the jump spring assembly comprises a first spring, the two ends of the first spring are respectively against two first spring seats, the first spring seat at the left end is against the axial shoulder of the first push rod, the first spring seat at the right end is against the first sliding sleeve, a small cover is connected to the left end of the small chamber, the bellows assembly comprises a bellows body, an air inlet nozzle and a top pressure plate, the air inlet nozzle is sealed and connected to the left end of the bellows body, the top pressure plate is sealed and connected to the right end of the bellows body, the bellows body is arranged in the small cover, the top pressure plate is against the left and right sides of the first push rod, and the air inlet nozzle penetrates and is fixed on the small cover;

[0008] The upper spring cover is fixed to the upper side wall of the main chamber through a guide sleeve, a second sliding sleeve is provided at the top of the upper spring cover, the upper part of the upper valve stem is slidably matched with the second sliding sleeve, the lower part of the upper valve stem is slidably matched with the guide sleeve, the upper spring assembly is sleeved on the upper valve stem, the upper spring assembly is in the upper spring cover, the upper spring assembly includes a second spring, the two ends of the second spring are respectively against two second spring seats, the second spring seat at the upper end is against the second sliding sleeve, the second spring seat at the lower end is against the shaft shoulder of the upper valve stem, the lower end of the upper valve stem extends into the main chamber, and is hinged to the upper end of the upper connecting rod;

[0009] The second push rod passes through the lower side wall of the main chamber, and the second push rod is slidably matched with the lower side wall of the main chamber. The upper end of the second push rod is provided with a flange structure, and a return spring is sleeved on the second push rod. The two ends of the return spring are respectively against the lower side wall of the main chamber and the flange structure. The upper end of the second push rod is hinged to the lower end of the lower connecting rod, and the lower end of the upper connecting rod and the upper end of the lower connecting rod are hinged through the main pin shaft, and a roller is sleeved on the main pin shaft. The upper valve stem and the second push rod are coaxially arranged, and the air inlet nozzle is connected to the protected container through the pressure taking pipe, and the medium inlet of the spring safety valve is connected to the protected container, and the shell is fixed to the spring safety valve through a bracket.

[0010] Furthermore, the outer periphery of the first sliding sleeve is threadedly connected to the partition and is locked by a first locking nut.

[0011] Furthermore, the outer periphery of the second sliding sleeve is threadedly connected to the upper spring cover and is locked by a second locking nut.

[0012] Furthermore, an inspection port is provided at the right end of the main chamber, and an end cover is removable to close the inspection port. A limiting pin is provided on the end cover, and when the roller protrudes to the right and the upper connecting rod and the lower connecting rod are folded together, the roller and the limiting pin are restrained against each other.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] When the medium pressure in the protected container is lower than the set pressure of the spring safety valve, the greater the medium pressure in the protected container, the greater the downward sliding stroke of the second push rod and the push pressure. By arranging the present invention on the top of the spring safety valve, without adding any electrical components, the spring safety valve can be assisted to achieve zero pre-leakage at the set pressure, and the sealing effect is better, thereby solving the possibility of steam leakage of the safety valve, avoiding more steam waste, and improving the economic benefits of power plant operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the present invention;

[0016] Figure 2 It is a schematic diagram of the application connection of the present invention;

[0017] Figure 3 It is a schematic diagram of the structure of the bellows assembly.

[0018] In the figure, 1. bellows assembly, 2. small cover, 3. first push rod, 4. take-off spring assembly, 5. first sliding sleeve, 6. first locking nut, 7. shell, 8. pressing nut, 9. roller, 10. guide sleeve, 11. upper valve stem, 12. upper spring assembly, 13. upper spring cover, 14. second sliding sleeve, 15. second locking nut, 16. end cover, 17. upper connecting rod, 18. lower connecting rod, 19. limit pin, 20. second push rod, 21. reset spring, 22. safety valve stem, 23. spring safety valve, 24. protected container, 25. pressure taking pipe, 26. air inlet nozzle, 27. bellows body, 28. pressing plate. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0020] The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection is a non-detachable connection including but not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but not limited to conventional detachable methods such as bolt connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can be found in the existing connection methods to achieve the function, and those skilled in the art can choose according to their needs. For example: welding connection is selected for fixed connection, and bolt connection is selected for detachable connection.

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings. The following embodiments are provided to explain the present invention, but the present invention is not limited to the following embodiments.

[0022] Example: Figure 1 to Figure 3 As shown, a safety valve anti-leakage device, the safety valve is a spring safety valve 23, the lower opening of the spring safety valve 23 is the medium inlet, the side opening of the spring safety valve 23 is the medium outlet, the spring safety valve 23 is provided with a safety valve stem 22, the lower end of the safety valve stem 22 is connected to the valve disc, the valve disc opens and closes the valve seat arranged on the medium inlet, the upper end of the safety valve stem 22 of the spring safety valve 23 passes through the valve cover of the spring safety valve 23 upward, and the safety valve stem 22 and the valve cover are slidably sealed:

[0023] The anti-leakage device comprises a shell 7, a partition is provided in the middle of the shell 7, the partition divides the shell 7 into a small chamber located on the left and a main chamber on the right, a first sliding sleeve 5 is provided on the partition, a first push rod 3 passes through the first sliding sleeve 5, the first push rod 3 and the first sliding sleeve 5 are slidably matched, the right end of the first push rod 3 is inserted into the main chamber and is connected to the top pressure nut 8, the left part of the first push rod 3 is sleeved with a jump spring assembly 4, the jump spring assembly 4 is in the small chamber, the jump spring assembly 4 comprises a first spring, the two ends of the first spring are respectively connected to two The first spring seats are correspondingly abutted against each other, the first spring seat at the left end abuts against the shaft shoulder of the first push rod 3, and the first spring seat at the right end abuts against the first sliding sleeve 5. The small cover 2 is connected to the left end of the small chamber. The bellows assembly 1 includes a bellows body 27, an air inlet nozzle 26 and a top pressure plate 28. The air inlet nozzle 26 is sealed and connected to the left end of the bellows body 27, and the top pressure plate 28 is sealed and connected to the right end of the bellows body 27. The bellows body 27 is arranged in the small cover 2, and the top pressure plate 28 abuts against the first push rod 3 on the left and right. The air inlet nozzle 26 penetrates and is fixed on the small cover 2;

[0024] The upper spring cover 13 is fixed on the upper side wall of the main chamber through the guide sleeve 10. The top of the upper spring cover 13 is provided with a second sliding sleeve 14. The upper part of the upper valve stem 11 is slidably matched with the second sliding sleeve 14. The lower part of the upper valve stem 11 is slidably matched with the guide sleeve 10. The upper spring assembly 12 is sleeved on the upper valve stem 11. The upper spring assembly 12 is in the upper spring cover 13. The upper spring assembly 12 includes a second spring. The two ends of the second spring are respectively against two second spring seats. The second spring seat at the upper end is against the second sliding sleeve 14. The second spring seat at the lower end is against the shaft shoulder of the upper valve stem 11. The lower end of the upper valve stem 11 extends into the main chamber and is hinged to the upper end of the upper connecting rod 17.

[0025] The second push rod 20 passes through the lower side wall of the main chamber, and the second push rod 20 is slidably matched with the lower side wall of the main chamber. The upper end of the second push rod 20 is provided with a flange structure, and a return spring 21 is sleeved on the second push rod 20. The two ends of the return spring 21 are respectively against the lower side wall of the main chamber and the flange structure. The upper end of the second push rod 20 is hinged to the lower end of the lower connecting rod 18, and the lower end of the upper connecting rod 17 and the upper end of the lower connecting rod 18 are hinged through the main pin shaft. A roller 9 is sleeved on the main pin shaft, and the outer periphery of the roller 9 protrudes from the upper connecting rod 17 and the lower connecting rod 18. The upper valve stem 11 and the second push rod 20 are coaxially arranged, and the air inlet nozzle 26 is connected to the protected container 24 through the pressure taking pipe 25. The medium inlet of the spring safety valve 23 is connected to the protected container 24, and the shell 7 is fixed to the spring safety valve 23 through a bracket.

[0026] When the pressure in the protected container 24 is normal pressure, the axis of the roller 9 is on the left side of the axis of the second push rod 20, the bellows body 27 is in a contracted state, the first push rod 3 slides to the left under the elastic force of the jump spring assembly 4, the upper valve stem 11 slides downward under the elastic force of the upper spring assembly 12, the second push rod 20 slides upward under the elastic force of the return spring 21, and the upper end of the upper connecting rod 17 and the lower end of the lower connecting rod 18 are folded together;

[0027] When there is a high-pressure medium in the protected container 24 and the medium pressure in the protected container 24 is less than the set pressure of the spring safety valve 23, the high-pressure medium in the protected container 24 is filled into the bellows body 27 through the pressure-taking pipe 25, and the bellows body 27 expands axially and pushes the first push rod 3 to slide rightward, thereby driving the pressure nut 8 to push the roller 9 rightward, so that the axis of the roller 9 approaches the axis of the second push rod 20, or the axis of the roller 9 coincides with the axis of the second push rod 20, the upper end of the upper connecting rod 17 and the lower end of the lower connecting rod 18 are separated and stretched apart, and the upper spring assembly 12 applies a downward elastic force to the upper valve stem 11, and the upper valve stem 11 is pressed against the safety valve stem 22 through the upper connecting rod 17, the lower connecting rod 18 and the second push rod 20 in sequence;

[0028] When the medium pressure in the protected container 24 reaches the set pressure of the spring safety valve 23, the bellows body 27 continues to expand axially, and through the push of the first push rod 3, the axis of the roller 9 is moved to the right side of the axis of the second push rod 20, the upper end of the upper connecting rod 17 and the lower end of the lower connecting rod 18 are folded together, and the second push rod 20 is separated from the safety valve stem 22 and slides upward under the elastic force of the return spring 21, and the spring safety valve 23 opens under the pressure of the medium.

[0029] When the medium pressure in the protected container 24 is lower than the set pressure of the spring safety valve 23, the greater the medium pressure in the protected container 24 is, the greater the downward sliding stroke and the top pressure of the second push rod 20 are. By arranging the present invention on the top of the spring safety valve, without adding any electrical components, the spring safety valve can be assisted to achieve zero pre-leakage at the set pressure, and the sealing effect is better, which solves the possibility of steam leakage of the safety valve, avoids more steam waste, and improves the economic benefits of power plant operation.

[0030] The outer periphery of the first sliding sleeve 5 is threadedly connected to the partition and is locked by the first locking nut 6. By adjusting the relative position of the first sliding sleeve 5 and the partition, the spring preload force of the jump spring assembly 4 can be adjusted, and then the medium pressure filled into the bellows body 27 when the second push rod 20 is separated from the safety valve stem 22 can be changed, and the set pressure adjustment of the spring safety valve 23 can adapt to a spring safety valve with a wider set pressure.

[0031] The outer periphery of the second sliding sleeve 14 is threadedly connected to the upper spring cover 13 and is locked by a second locking nut 15. By adjusting the relative position of the second sliding sleeve 14 and the upper spring cover 13, the force applied by the second push rod 20 to the safety valve stem 22 can be adjusted.

[0032] The right end of the main chamber is provided with an inspection port, and the end cover 16 can be detachably closed to close the inspection port. A limiting pin 19 is provided on the end cover 16. When the roller 9 protrudes to the right and the upper connecting rod 17 and the lower connecting rod 18 are folded together, the roller 9 and the limiting pin 19 are restrained. After the spring safety valve is activated, the roller 9 can be manually pushed back to the left side of the axis of the second push rod through the end cover 16. The function of the limiting pin 19 is to prevent the roller 9 from directly hitting the end cover 16 to prevent the end cover 16 from being damaged.

[0033] The above embodiments are merely exemplary descriptions of the present invention and do not limit its protection scope. Those skilled in the art may also make partial changes thereto, which are within the protection scope of the present invention as long as they do not exceed the spirit of the present invention.

Claims

1. A safety valve anti-leakage device, wherein the safety valve is a spring safety valve (23), the lower opening of the spring safety valve (23) is a medium inlet, and the upper end of the safety valve stem (22) passes through the spring safety valve (23) upward: Features: The anti-leakage device comprises a shell (7), a partition is provided in the middle of the shell (7), the partition divides the shell (7) into a small chamber located at the left part and a main chamber at the right part, a first sliding sleeve (5) is provided on the partition, a first push rod (3) is slidably matched with the first sliding sleeve (5), the right end of the first push rod (3) extends into the main chamber and is connected to the top pressure nut (8), a jump spring assembly (4) is sleeved on the left part of the first push rod (3), the jump spring assembly (4) is in the small chamber, and the jump spring assembly (4) comprises a first spring, the two ends of the first spring are respectively against the two first spring seats, and the left end of the first push rod (3) is connected to the first spring seat. The first spring seat abuts against the shaft shoulder of the first push rod (3), the first spring seat at the right end abuts against the first sliding sleeve (5), the small cover (2) is connected to the left end of the small chamber, the bellows assembly (1) comprises a bellows body (27), an air inlet nozzle (26) and a top pressure plate (28), the air inlet nozzle (26) is sealed and connected to the left end of the bellows body (27), the top pressure plate (28) is sealed and connected to the right end of the bellows body (27), the bellows body (27) is arranged in the small cover (2), the top pressure plate (28) abuts against the first push rod (3) on the left and right, and the air inlet nozzle (26) penetrates and is fixed on the small cover (2); The upper spring cover (13) is fixed to the upper side wall of the main chamber through a guide sleeve (10). A second sliding sleeve (14) is provided at the top of the upper spring cover (13). The upper part of the upper valve stem (11) is slidably matched with the second sliding sleeve (14). The lower part of the upper valve stem (11) is slidably matched with the guide sleeve (10). The upper spring assembly (12) is sleeved on the upper valve stem (11). The upper spring assembly (12) is located in the upper spring cover (13). The upper spring assembly (12) includes a second spring. The two ends of the second spring are respectively abutted against two second spring seats. The second spring seat at the upper end is abutted against the second sliding sleeve (14). The second spring seat at the lower end is abutted against the shaft shoulder of the upper valve stem (11). The lower end of the upper valve stem (11) extends into the main chamber and is hinged to the upper end of the upper connecting rod (17). The second push rod (20) passes through the lower side wall of the main chamber, and the second push rod (20) is slidably matched with the lower side wall of the main chamber. The upper end of the second push rod (20) is provided with a flange structure, and a return spring (21) is sleeved on the second push rod (20). The two ends of the return spring (21) are respectively against the lower side wall of the main chamber and the flange structure. The upper end of the second push rod (20) is hinged to the lower end of the lower connecting rod (18), and the lower end of the upper connecting rod (17) and the upper end of the lower connecting rod (18) are hinged through a main pin shaft. A roller (9) is sleeved on the main pin shaft. The upper valve stem (11) and the second push rod (20) are coaxially arranged. The air inlet nozzle (26) is connected to the protected container (24) through a pressure taking pipe (25), and the medium inlet of the spring safety valve (23) is connected to the protected container (24). The shell (7) is fixed to the spring safety valve (23) through a bracket.

2. A safety valve anti-leakage device according to claim 1, characterized in that: The outer periphery of the first sliding sleeve (5) is threadedly connected to the partition plate and is locked by a first locking nut (6).

3. A safety valve anti-leakage device according to claim 1, characterized in that: The outer periphery of the second sliding sleeve (14) is threadedly connected to the upper spring cover (13) and is locked by a second locking nut (15).

4. A safety valve anti-leakage device according to any one of claims 1 to 3, characterized in that: An inspection port is provided at the right end of the main chamber. An end cover (16) is detachably provided to close the inspection port. A limiting pin (19) is provided on the end cover (16). When the roller (9) protrudes to the right and the upper connecting rod (17) and the lower connecting rod (18) are folded together, the roller (9) and the limiting pin (19) are abutted against each other to limit the position.

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