Large nuclear-grade vertical pump mechanical seal pressing device

Abstract

The invention belongs to the technical field of nuclear power station nuclear-grade rotating equipment maintenance engineering, and particularly relates to a large nuclear-grade vertical pump mechanical seal pressing device. Dynamic and static ring sealing rings are mounted in sealing grooves of the static ring seat and the dynamic ring seat; a dynamic ring and a static ring are correspondingly mounted at the upper parts of the sealing grooves respectively; the whole static ring seat is installed in the static ring shell, axial sealing is achieved through the static ring seat sealing ring and the teflon gasket, and the static ring seat and the static ring shell are axially and fixedly provided with the radial pin. A water outlet is formed in the lower part of the pressurizing shell, a sealing plug is mounted at the water outlet in the pressurizing process, and meanwhile, a pressure gauge is arranged; the sealing body is installed on the upper portion of the pressing shell for sealing, the pump shaft is connected with the pressing sealing body, the sealing shaft sleeve is installed on the pump shaft, the shaft sleeve gland is arranged on the upper portion of the sealing shaft sleeve, the sealing shaft sleeve is pressed through the shaft sleeve pressing bolt, the pump shaft sealing ring is arranged on the lower portion of the sealing shaft sleeve, and two-stage sealing is installed in a sealing cavity formed by the pump shaft and the sealing body. Sealing pressure can be continuously and stably provided, and the sealing performance of the mechanical seal is effectively verified.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power plant nuclear-grade rotating equipment maintenance engineering, and in particular relates to a large-scale nuclear-grade vertical pump mechanical seal pressure device. Background Art

[0002] Mechanical seal is a shaft sealing device used for rotating fluid machinery. The mechanical seal of nuclear-grade rotating equipment in nuclear power plants is one of the most important components. Its function is to seal the medium flowing through the equipment so that the medium in the equipment does not leak out, and at the same time, to ensure that impurities outside the equipment do not enter the equipment to cause medium pollution. The sealing performance of mechanical seals is an important basis for the safe operation of rotating equipment in nuclear power plants. Under certain specific working conditions, multi-stage mechanical seals are required. For important rotating equipment in the primary circuit of a nuclear power plant, the medium flowing through it is usually a radioactive medium. The leakage of radioactive media will not only cause insufficient output of the equipment itself, but also pollute other surrounding equipment and the environment, seriously affecting the development of on-site maintenance work. The increase in environmental dose rate will inevitably lead to a substantial increase in the radiation dose of maintenance personnel, resulting in serious consequences. Therefore, the performance of mechanical seals needs to be verified during the equipment maintenance process. For multi-stage seals, their sealing performance can be verified by pressure testing alone. Summary of the invention

[0003] The purpose of the present invention is to provide a large-scale nuclear-grade vertical pump mechanical seal pressure device, which has a compact structure, is easy to assemble, has good sealing performance and strong stability during use, can continuously and stably provide sealing pressure, and effectively verify the sealing performance of the mechanical seal.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A mechanical seal pressure device for a large nuclear-grade vertical pump, wherein the dynamic and static ring seals are installed in the sealing grooves of the static ring seat and the dynamic ring seat, and the dynamic ring and the static ring are installed in the upper part of the sealing groove respectively; the static ring seat is installed in the static ring housing as a whole, and the axial sealing is achieved by the static ring seat seal and the polytetrafluoroethylene gasket, the static ring housing is provided with a spring, and the static ring seat and the static ring housing are axially fixed with radial pins; a drain port is provided at the lower part of the pressure housing, and a sealing plug is installed at the drain port during the pressure process, and a pressure gauge is also provided; a sealing body is installed at the upper part of the pressure housing for sealing, and the pump shaft is connected to the pressure sealing body , the sealing sleeve is installed on the pump shaft, a sleeve gland is provided on the upper part, the sealing sleeve is compressed by the sleeve compression bolt, a pump shaft sealing ring is provided on the lower part, and the two-stage seal is installed in the sealing chamber formed by the pump shaft and the sealing body, a dynamic ring sleeve sealing ring is provided between the static ring seat and the dynamic ring seat, a static ring housing sealing ring is installed at the matching position between the static ring housing, the sealing body and the sealing gland, a sealing sleeve is installed on the upper part of the static ring housing, a sealing pressure adjustment pad is provided on the lower part of the static ring housing, the sealing gland is connected with the sealing body, a sealing card is provided on the sealing gland, and a dynamic ring gland is provided on the upper part of the sealing card.

[0006] The sealing body is installed on the upper part of the pressure shell for sealing, and the two are connected by the sealing body clamping bolts.

[0007] The sealing body is installed on the upper part of the pressure shell for sealing. The two are connected by the sealing body clamping bolts, and a sealing body sealing ring is installed at the matching position.

[0008] The pump shaft is connected to the pressure seal body through the pump shaft fastening bolts.

[0009] The sealing gland is connected to the sealing body through the sealing gland bolts.

[0010] The fastening bolts of the dynamic ring sleeve are installed on the dynamic ring pressure cover.

[0011] Fill the sealing cavity with a medium at a pressure of 4MPa and maintain the pressure for 15 minutes. During this period, continuously observe the pressure indication and whether there is leakage at each joint surface. If the pressure drops and leakage occurs at the same time, it is necessary to check the static ring housing seal, sealing body seal, pump shaft seal and dynamic ring sleeve seal according to the leakage point; Fill the sealing cavity with a medium at a pressure of 4MPa and maintain the pressure for 15 minutes. During this period, continuously observe the pressure indication and whether there is leakage at each joint surface. If the pressure drops and there is no leakage at the same time, it is necessary to check the static ring seat seal, dynamic and static ring seals, and polytetrafluoroethylene gasket, and calculate the compression amount according to the sealing pressure adjustment pad. If the compression amount is small, turn the adjustment pad; if the compression amount is large, replace it with a thicker adjustment pad; Fill the sealing cavity with a medium at a pressure of 4MPa and maintain the pressure for 15 minutes. During this period, continuously observe the pressure indication and whether there is no drop, then it can be judged that the sealing is good.

[0012] The pressure device can perform a two-stage sealing test at a time.

[0013] The beneficial effects achieved by the present invention are:

[0014] The mechanical seal pressure device for a large nuclear-grade vertical pump of the present invention has a compact structure and can effectively improve installation efficiency;

[0015] The mechanical seal pressure-pressing device for a large nuclear-grade vertical pump of the present invention has strong stability and can avoid damage to equipment components during the pressure-pressing process;

[0016] The mechanical seal pressure device for a large nuclear-grade vertical pump of the present invention has good sealing performance and can continuously provide effective sealing pressure;

[0017] The large-scale nuclear-grade vertical pump mechanical seal pressure device of the present invention can be assembled and used as a whole, which can effectively reduce the radiation dose level of operators;

[0018] A large-scale nuclear-grade vertical pump mechanical seal pressure device of the present invention is equipped with a pressure monitoring device, which can effectively monitor the pressure change in the sealing cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a mechanical seal assembly diagram of a large-scale nuclear-grade vertical pump mechanical seal pressure device of the present invention;

[0020] Figure 2 This is a front view of a large-scale nuclear-grade vertical pump mechanical seal pressure device of the present invention;

[0021] In the figure: 1. sealing sleeve, 2. static ring seat sealing ring, 3. static ring housing sealing ring, 4. dynamic and static ring sealing rings, 5. spring, 6. radial pin, 7. pump shaft sealing ring, 8. PTFE gasket, 9. static ring housing, 10. static ring seat, 11. static ring, 12. dynamic ring, 13. dynamic ring seat, 14. dynamic ring gland, 15. dynamic ring sleeve fastening bolt, 16. shaft sleeve clamping bolt, 17. shaft sleeve gland, 18. sealing gland bolt, 19. sealing gland, 20. pump shaft, 21. pressure gauge, 22. sealing body, 23. pressure sealing body, 24. pressure housing, 25. sealing plug, 26. sealing card, 27. sealing sleeve, 28. sealing body sealing ring, 29. sealing body clamping bolt, 30. dynamic ring sleeve sealing ring, 31. sealing pressure adjustment pad, 32. pump shaft fastening bolt. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] The mechanical seal pressure device of a large nuclear-grade vertical pump comprises a sealing sleeve 1, a static ring seat sealing ring 2, a static ring housing sealing ring 3, dynamic and static ring sealing rings 4, a spring 5, a radial pin 6, a pump shaft sealing ring 7, a polytetrafluoroethylene gasket 8, a static ring housing 9, a static ring seat 10, a static ring 11, a dynamic ring 12, a dynamic ring seat 13, a dynamic ring gland 14, a dynamic ring sleeve fastening bolt 15, a sleeve clamping bolt 16, a sleeve clamping cover 17, a sealing gland bolt 18, a sealing gland 19, a pump shaft 20, a pressure gauge 21, a sealing body 22, a pressure seal body 23, a pressure housing 24, a sealing plug 25, a sealing card 26, a sealing sleeve 27, a sealing body sealing ring 28, a sealing body clamping bolt 29, a dynamic ring sleeve sealing ring 30, a sealing pressure adjustment pad 31, and a pump shaft fastening bolt 32. The sealing body is connected to the pressure shell through the sealing body clamping bolts; the pump shaft is fixed to the pressure sealing body through the pump shaft fastening bolts; the sealing body is connected to the sealing gland through the sealing gland bolts.

[0024] The large-scale nuclear-grade vertical pump mechanical seal pressure testing device is mainly composed of two major components: a mechanical seal and a pressure testing device body. The pressure testing device can perform a sealing test of two-stage seals at a time.

[0025] The single-stage mechanical seal is as follows: the dynamic and static ring seal ring 4 is installed in the sealing groove of the static ring seat 10 and the dynamic ring seat 13, and the dynamic ring 12 and the static ring 11 are installed on the upper part of the sealing groove. The static ring seat 10 is installed in the static ring housing 9 as a whole, and the axial sealing is achieved by the static ring seat seal ring 2 and the PTFE gasket 8. The static ring housing 9 is provided with a spring 5 to adjust the compression amount, and the static ring seat 10 and the static ring housing 9 are axially fixed with a radial pin 6.

[0026] The main body of the pressure device is as follows: the pressure shell 24 is used as the main body, and a drain port is provided at the bottom. A sealing plug 25 is installed at the drain port during the pressure process. At the same time, a pressure gauge 21 is provided for monitoring the pressure pressure. The sealing body 22 is installed on the upper part of the pressure shell 24 for sealing. The two are connected by a sealing body clamping bolt 29, and a sealing body sealing ring 28 is installed at the mating position. The pump shaft 20 is connected to the pressure seal body 23 by a pump shaft fastening bolt 32. The sealing sleeve 1 is installed on the pump shaft 20, and a sleeve gland 17 is provided on the upper part. The sealing sleeve 1 is compressed by the sleeve clamping bolt 16. A pump shaft sealing ring 7 is provided at the lower part. The two-stage seal is installed on the pump shaft 2 0 and the sealing body 22, a dynamic ring sleeve sealing ring 30 is arranged between the static ring seat 10 and the dynamic ring seat 13, a static ring housing sealing ring 3 is installed at the matching position of the static ring housing 9, the sealing body 22 and the sealing gland 19, a sealing sleeve 27 is installed on the upper part of the static ring housing 9 of the previous level, and a sealing pressure adjustment pad 31 is arranged on the lower part of the housing to adjust the compression amount, the sealing gland 19 is connected to the sealing body 22 by the sealing gland bolt 18, a sealing card 26 is arranged on the sealing gland 19, and a dynamic ring gland 14 is arranged on the upper part of the sealing card 26 to adjust the dynamic ring compression amount, and the adjustment method is to adjust the dynamic ring sleeve fastening bolt 15 installed on the dynamic ring gland 14.

[0027] The present invention is implemented in this way:

[0028] Step (1) Installation of the mechanical seal assembly includes the following operations:

[0029] Step (1.1) Check and confirm that the dynamic and static rings of the mechanical seal are in good condition, without any bumps or damage;

[0030] Step (1.2) Check that all the metal parts of the mechanical seal have been decontaminated in the decontamination device and have been cleaned;

[0031] Step (1.3) Operators should wear additional radiation protection equipment such as paper clothes, rubber gloves, waterproof high-top shoe covers and air masks as required, and take personal protection measures.

[0032] Step (1.4) Check that the pressure shell is clean and free of foreign matter;

[0033] Step (1.5) Apply vacuum silicone grease to the dynamic and static ring seal ring 4 and install it into the dynamic ring seat 13, and install the dynamic ring 12 into the dynamic ring seat 13;

[0034] Step (1.6) Apply vacuum silicone grease to the dynamic and static ring seal ring 4 and install it into the static ring seat 10, and install the static ring 11 into the static ring seat 10;

[0035] Step (1.7) Install the stationary ring housing seal ring into the stationary ring seat 10 groove;

[0036] Step (1.8) Soak the PTFE gasket 8 in hot water for 15 minutes, install the PTFE gasket into the groove of the stationary ring seat 10, and clamp it with a special clamp for 10 minutes;

[0037] Step (1.9) Install the spring 5 into the stationary ring housing 9, and install the stationary ring seat 10 as a whole into the stationary ring housing 9;

[0038] Step (1.10) Repeat steps (1.4) to (1.8) to reinstall the second-stage mechanical seal dynamic and static ring housing;

[0039] Step (2) installs the mechanical seal assembly into the pressure device, including the following operations:

[0040] Step (2.1) Install the pump shaft 20 into the pressure housing 24, tighten the pump shaft fastening bolts 32, and confirm that the pump shaft is stable;

[0041] Step (2.2) Install the sealing ring 28 of the sealing body into the groove, hang the sealing body 22 into the pressure shell 24, and tighten the sealing body clamping bolt 29 to ensure that the two are firmly connected. This step involves the sealing liquid boundary, and the bolt torque must be tightened as required;

[0042] Step (2.3) Install the sealing sleeve 1 onto the pump shaft 20. The two are clearance-fitted, but the clearance is small. If there is any jamming during the reinstallation process, the sealing sleeve 1 must be removed, and the burrs on the sealing sleeve 1 and the pump shaft 20 must be polished and repaired before installation.

[0043] Step (2.4) Install the dynamic ring sleeve seal 30 on the first-stage sealing dynamic ring seat 13, and install the first-stage sealing dynamic ring seat 13 on the pump shaft 20;

[0044] Step (2.5) Install the sealing pressure adjustment pad 31 into the sealing body 22, and install the first-stage sealing static ring housing 9 as a whole into the sealing body 22;

[0045] Step (2.6) Install the stationary ring housing seal ring 3 into the first-stage sealing stationary ring housing 9 groove. Since the stationary ring housing seal ring 3 is larger than the groove, the stationary ring housing seal ring 3 needs to be fully pressed into it before the second-stage seal can be installed;

[0046] Step (2.7) Repeat steps (2.3) to (2.6) to install the second-stage seal as a whole into the pump shaft 20 and the seal body 22;

[0047] Step (2.8) Install the sealing gland 19 onto the sealing body 22 and tighten the sealing gland bolts 18;

[0048] Step (2.9) The sealing sleeve 27 is installed on the sealing sleeve 1. The sealing sleeve 27 and the sealing sleeve 1 are clearance matched. Since the clearance match is small, if there is a jam during the assembly process, the sealing body needs to be removed in time, and the burrs of both are polished and repaired to be smooth;

[0049] Step (2.10) Install the sleeve gland 17 onto the pump shaft 20, install two sealing clips 26 onto the sealing sleeve 1, and tighten the sleeve compression bolts 16;

[0050] Step (2.11) Install the dynamic ring gland 14 onto the pump shaft 20 and tighten the dynamic ring sleeve with the bolts 15;

[0051] Step (2.12) installs the pressure gauge 21 on the pressure measuring line;

[0052] Step (1) the mechanical seal assembly and step (2) the pressure device have been assembled, and step (3) the pressure work begins:

[0053] Step (3.1) Check that all fasteners have been tightened and there are no abnormalities;

[0054] Step (3.2) Fill the sealing cavity with a medium at a pressure of 4 MPa and maintain the pressure for 15 minutes. During this period, continuously observe the pressure indication and whether there is leakage at each joint surface. If the pressure drops and leakage occurs at the same time, it is necessary to check the static ring housing seal 3, the sealing body seal 28, the pump shaft seal 7 and the dynamic ring sleeve seal 30 according to the leakage point;

[0055] Step (3.3) Fill the sealing cavity with a medium at a pressure of 4 MPa and maintain the pressure for 15 minutes. During this period, continuously observe the pressure indication and whether there is leakage at each joint surface. If the pressure drops and there is no leakage at the same time, it is necessary to check the static ring seat seal 2, the dynamic and static ring seal 4, and the polytetrafluoroethylene gasket 8, and calculate the compression amount according to the sealing pressure adjustment pad. If the compression amount is small, turn the adjustment pad. If the compression amount is large, replace it with a thicker adjustment pad;

[0056] Step (3.4) Fill the sealing cavity with a medium at a pressure of 4 MPa and maintain the pressure for 15 minutes. If the pressure indicator reading does not drop during this period, it can be judged that the sealing performance of the mechanical seal assembly is good.

[0057] The single-stage mechanical seal is matched as follows: the dynamic and static ring seal ring 4 is installed in the sealing grooves of the static ring seat 10 and the dynamic ring seat 13, and the dynamic ring and the static ring are installed on the upper part of the sealing groove. The static ring seat 10 is installed in the static ring housing 9 as a whole, and the axial sealing is achieved through the static ring seat seal ring 2 and the PTFE gasket 8. The static ring housing 9 is provided with a spring 5 to adjust the compression amount, and the static ring seat 10 and the static ring housing 9 are axially fixed with a radial pin 6. The main body of the pressure device is mainly matched as follows: the pressure shell 24 is used as the main body, and a drain port is provided at the bottom. A sealing plug 25 is installed at the drain port during the pressure process. At the same time, a pressure gauge 21 is provided for monitoring the pressure. The sealing body 22 is installed on the upper part of the pressure shell 24 for sealing. The two are connected by a sealing body clamping bolt 29. A sealing body sealing ring 28 is installed at the matching position. The pump shaft 20 is connected to the pressure sealing body 23 by a pump shaft fastening bolt 32. The sealing sleeve 1 is installed on the pump shaft 20. A sleeve gland 17 is provided on the upper part. The sealing sleeve 1 is compressed by the sleeve clamping bolt 16. A pump shaft sealing ring 7 is provided at the lower part. The two-stage sealing is installed. A sealing ring 30 is arranged between the stationary ring seat 10 and the dynamic ring seat 13 in the sealing chamber formed by the pump shaft 20 and the sealing body 22. The stationary ring housing sealing ring 3 is installed at the matching position of the stationary ring housing 9, the sealing body 22 and the sealing cover 19. A sealing sleeve 27 is installed on the upper part of the upper-level stationary ring housing 9, and a sealing pressure adjustment pad 31 is arranged on the lower part of the housing to adjust the compression amount. The sealing cover 19 is connected to the sealing body 22 by the sealing cover bolt 18. A sealing card 26 is arranged on the sealing cover 19, and a dynamic ring cover 14 is arranged on the upper part of the sealing card 26 to adjust the dynamic ring compression amount. The adjustment method is to adjust the dynamic ring sleeve fastening bolt 15 installed on the dynamic ring cover 14.

Claims

1. A large-scale nuclear-grade vertical pump mechanical seal pressure device, characterized in that: The dynamic and static ring seals are installed in the sealing grooves of the static ring seat and the dynamic ring seat, and the dynamic ring and the static ring are installed on the upper part of the sealing groove respectively; the static ring seat is installed as a whole in the static ring housing, and axial sealing is achieved through the static ring seat seal and the PTFE gasket. The static ring housing is provided with a spring, and the static ring seat and the static ring housing are axially fixed with radial pins; a drain port is provided at the lower part of the pressure shell, and a sealing plug is installed at the drain port during the pressure process, and a pressure gauge is also provided; the sealing body is installed on the upper part of the pressure shell for sealing, the pump shaft is connected to the pressure sealing body, and the sealing sleeve is installed to the pump On the shaft, a shaft sleeve gland is arranged at the upper part, and the sealing shaft sleeve is compressed by the shaft sleeve clamping bolt, a pump shaft sealing ring is arranged at the lower part, and the two-stage seal is installed in the sealing chamber formed by the pump shaft and the sealing body, a dynamic ring sleeve sealing ring is arranged between the static ring seat and the dynamic ring seat, a static ring housing sealing ring is installed at the matching place between the static ring housing, the sealing body and the sealing gland, a sealing sleeve is installed at the upper part of the static ring housing, a sealing pressure adjusting pad is arranged at the lower part of the static ring housing, the sealing gland is connected with the sealing body, a sealing card is arranged on the sealing gland, and a dynamic ring gland is arranged on the upper part of the sealing card.

2. The large-scale nuclear-grade vertical pump mechanical seal pressure device according to claim 1 is characterized in that: The sealing body is installed on the upper part of the pressure shell for sealing, and the two are connected by the sealing body clamping bolts.

3. The large-scale nuclear-grade vertical pump mechanical seal pressure device according to claim 2 is characterized in that: The sealing body is installed on the upper part of the pressure shell for sealing. The two are connected by the sealing body clamping bolts, and a sealing body sealing ring is installed at the matching position.

4. The large-scale nuclear-grade vertical pump mechanical seal pressure device according to claim 1 is characterized in that: The pump shaft is connected to the pressure seal body through the pump shaft fastening bolts.

5. The large-scale nuclear-grade vertical pump mechanical seal pressure device according to claim 1 is characterized in that: The sealing gland is connected to the sealing body through the sealing gland bolts.

6. The large-scale nuclear-grade vertical pump mechanical seal pressure device according to claim 1 is characterized in that: The fastening bolts of the dynamic ring sleeve are installed on the dynamic ring pressure cover.

7. The large-scale nuclear-grade vertical pump mechanical seal pressure device according to claim 3 is characterized in that: Fill the sealing cavity with a medium at a pressure of 4MPa and maintain the pressure for 15 minutes. During this period, continuously observe the pressure indication and whether there is leakage at each joint surface. If the pressure drops and leakage occurs at the same time, it is necessary to check the static ring housing seal, sealing body seal, pump shaft seal and dynamic ring sleeve seal according to the leakage point; Fill the sealing cavity with a medium at a pressure of 4MPa and maintain the pressure for 15 minutes. During this period, continuously observe the pressure indication and whether there is leakage at each joint surface. If the pressure drops and there is no leakage at the same time, it is necessary to check the static ring seat seal, dynamic and static ring seals, and polytetrafluoroethylene gasket, and calculate the compression amount according to the sealing pressure adjustment pad. If the compression amount is small, turn the adjustment pad; if the compression amount is large, replace it with a thicker adjustment pad; Fill the sealing cavity with a medium at a pressure of 4MPa and maintain the pressure for 15 minutes. During this period, continuously observe the pressure indication and whether there is no drop, then it can be judged that the sealing is good.

8. The large-scale nuclear-grade vertical pump mechanical seal pressure device according to claim 1 is characterized in that: The pressure device can perform a two-stage sealing test at a time.

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