A reactor mechanical seal ring nozzle cleaning tool and method of use

Abstract

This invention belongs to the field of nuclear power plant reactor maintenance technology, specifically relating to a cleaning tool and method for cleaning reactor mechanical seal ring nozzles. The core components include a core rod assembly, a conical sleeve, a skeleton sleeve, a telescopic plate, and a brush head. The core rod assembly is connected to the conical sleeve, which is installed below the core rod assembly. The skeleton sleeve is installed on the outside of the conical sleeve, with a wedge-shaped groove on its circumference concentric with the inner conical sleeve. The telescopic plate is inserted into the wedge-shaped groove on the circumference of the skeleton sleeve and is connected to a fitting positioning cover. The brush head is installed on the outside of the skeleton sleeve. The advantages are: rapid cleaning and simple operation; no damage to the nozzle sealing surface; safe and reliable after installation; and convenient replacement of cleaning materials. These three functions significantly reduce the time required for cleaning reactor graphite mechanical seal ring nozzles and decrease personnel exposure dose.

Description

Technical Field

[0001] This invention belongs to the field of nuclear power plant reactor maintenance technology, specifically relating to a cleaning tool for reactor mechanical seal ring nozzles and its usage method. Background Technology

[0002] The mechanical seal ring of existing nuclear power units serves as the interface module between the instrumentation penetration part inside the reactor pressure vessel and the outside world, representing the final pressure boundary of the primary circuit. The mechanical seal is sealed internally by two graphite sealing rings, one inner and one outer. During each refueling overhaul, the mechanical seal ring must be removed before opening the reactor pressure vessel cover. At this time, a large amount of solidified sealing graphite residue adheres to the inner surface of the nozzles in contact with the mechanical seal ring, which is difficult to clean and generates a high working dose. After the reactor pressure vessel cover is closed, the mechanical seal ring must be installed, requiring extremely high cleanliness of the nozzles in contact with the mechanical seal ring, directly affecting the performance of the mechanical seal after installation. Traditional cleaning methods involve manual cleaning with scouring pads and paper towels, which is inefficient and exposes personnel to higher radiation doses. Improper cleaning after normal use can damage the sealing surface or result in incomplete cleaning, posing a certain risk of reactor shutdown and potentially causing primary circuit pressure and media leakage. Summary of the Invention

[0003] The purpose of this invention is to provide a cleaning tool and method for reactor mechanical seal ring nozzles, freeing them from traditional manual cleaning methods and ensuring safe cleaning of reactor mechanical seal ring nozzles.

[0004] The technical solution of the present invention is as follows: A cleaning tool for the nozzle of a reactor mechanical seal ring, comprising a core component consisting of a core rod assembly, a conical sleeve, a skeleton sleeve, a telescopic plate, and a brush head; the core rod assembly is connected to the conical sleeve, the conical sleeve is installed below the core rod assembly, the skeleton sleeve is installed outside the conical sleeve, the skeleton sleeve has a wedge-shaped groove in the circumferential direction concentric with the inner conical sleeve, the telescopic plate is inserted into the wedge-shaped groove in the circumferential direction of the skeleton sleeve, the telescopic plate is connected to a fitting positioning cover, and the brush head is installed outside the skeleton sleeve.

[0005] The telescopic plate is connected to the fitting positioning cover by bolts at the top. The brush head fixing plate is installed on the plane in the middle of the telescopic plate to fix the lower part of the brush head and prevent the brush head from spreading out. Six threaded holes are opened at the bottom of the skeleton sleeve and connected to the base plate by bolts.

[0006] The telescopic plate has six pieces in the circumferential direction to ensure that it has a certain strength to open the outer brush head. By moving the core rod assembly downward, the six telescopic plates can be fully opened. When the core rod assembly moves upward, the six telescopic plates fall back to their initial position by their own weight, thus achieving the effect of opening the outer brush head downward and closing the brush head upward.

[0007] The core rod assembly and the conical sleeve are welded together by pins. A lifting handle is installed on the top of the core rod assembly by threads. The bottom part of the conical sleeve is positioned by a base plate pin to ensure concentricity. A telescopic plate and a skeleton sleeve are fitted onto the outside.

[0008] The brush head is fixed to the frame sleeve by a clamp and a brush head fixing plate; the positioning sleeve and the fitting positioning cover are fixed to the fitting positioning plate by a screw; the operating handle is connected to the fitting positioning plate by a thread; the lifting handle is fixed to the connecting plate by upper and lower nuts; and the quick-release pin is fixed to the connecting plate by a steel wire rope to prevent accidental fall.

[0009] The brush head is made of scouring pad.

[0010] The tapered sleeve has six wedge-shaped grooves of the same size around its circumference. The main function of these grooves is to provide a driving force for the internal telescopic plates to ensure that they can move simultaneously, thereby allowing the outer brush head to be fully expanded.

[0011] The conical sleeve has a groove in the center inside, which cooperates with the upper core rod assembly to form an integral unit.

[0012] The interior of the skeleton sleeve is hollow.

[0013] A method for using a cleaning tool for reactor mechanical seal ring nozzles includes the following steps:

[0014] 1) Assemble the reactor mechanical seal ring nozzle cleaning tool as a whole and test to confirm that the up and down movement is smooth and the brush head can be opened;

[0015] 2) Use the lifting handle to position the reactor mechanical seal ring nozzle cleaning tool onto the reactor mechanical seal ring nozzle;

[0016] 3) Remove the quick-release pin at the top of the reactor mechanical seal ring nozzle cleaning tool, lower the core rod to the lower limit position and insert the quick-release pin;

[0017] 4) Use the operating handle to rotate the entire tool to clean the reactor mechanical seal annulus nozzle;

[0018] 5) Add anhydrous ethanol for wet cleaning according to the actual working conditions on site;

[0019] 6) Wipe the sealing surface dry with a paper towel;

[0020] 7) Complete the cleaning and removal of the reactor mechanical seal ring nozzle cleaning tools.

[0021] The beneficial effects of this invention are: rapid and simple cleaning operation; no damage to the nozzle sealing surface; safe and reliable after installation; and convenient replacement of cleaning materials. Through these three functions, the cleaning time for reactor graphite mechanical seal ring nozzles can be significantly reduced, and the exposure dose to personnel can be decreased. This invention provides a cleaning tool for reactor mechanical seal ring nozzles, eliminating the need for traditional manual cleaning methods, reducing the risk of human error, ensuring safe cleaning of reactor mechanical seal ring nozzles, and also expanding the mechanization of traditional manual cleaning methods, making it highly applicable and widely applicable. Attached Figure Description

[0022] Figure 1 This is a front view of a tool for cleaning the ring nozzle of a reactor mechanical seal provided by the present invention;

[0023] Figure 2 for Figure 1 Top view;

[0024] Figure 3 for Figure 1 Cross-sectional view;

[0025] Figure 4 for Figure 3 Top view;

[0026] Figure 5 Exploded view of a cleaning tool for reactor mechanical seal ring nozzle provided by the present invention;

[0027] Figure 6 This is a schematic diagram of a tool for cleaning the nozzle of a reactor mechanical seal ring, provided by the present invention.

[0028] In the diagram: 1. Core rod assembly, 2. Conical sleeve, 3. Skeleton sleeve, 4. Telescopic plate, 5. Brush head, 6. Base plate, 7. Fitting positioning cover, 8. Operating handle, 9. Lifting handle, 10. Quick release pin, 11. Brush head fixing plate, 12. Positioning sleeve, 13. Clamp, 14. Reactor mechanical seal ring nozzle. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1-5 As shown, a cleaning tool for the mechanical seal ring nozzle of a reactor includes core components such as a core rod assembly 1, a conical sleeve 2, a skeleton sleeve 3, a telescopic plate 4, and a brush head 5. After the reactor top cover is moved to the storage rack, the entire tool is installed on the mechanical seal ring nozzle. The brush head assembly quickly expands due to the falling of the core rod assembly and the cooperation of the conical sleeve and telescopic plate, allowing the entire tool's brush head to fully contact the inner wall of the mechanical seal ring nozzle for cleaning, thus ensuring safe and efficient cleaning of the reactor mechanical seal ring nozzle.

[0031] The core rod assembly 1 is installed at the exact center of the entire tool. The lower part of the core rod assembly 1 is provided with a boss and drilled holes to fit with the groove of the conical sleeve 2 to ensure concentricity. The core rod assembly 1 and the conical sleeve 2 are connected by a pin to ensure that the two will not be displaced. The upper half of the core rod assembly 1 has a pin hole on its side end to fit with the outer sleeve. The entire brush head can be retracted and expanded by raising and lowering the core rod assembly 1. The upper end of the core rod assembly 1 is provided with an internal threaded hole for installing the operating handle of the core rod assembly.

[0032] The conical sleeve 2 is installed below the core rod assembly 1. The conical sleeve 2 has six wedge-shaped grooves of the same size in the circumferential direction. Its main function is to provide a pushing force for the internal telescopic plate to ensure that it can move at the same time, so that the outer brush head can be fully opened. The conical sleeve 2 has a groove in the center inside, which cooperates with the upper core rod assembly 1 to form an integral unit.

[0033] The skeleton sleeve 3 is hollow inside to reduce weight and is installed on the outside of the conical sleeve 2. The skeleton sleeve 3 has six wedge-shaped grooves on its circumference, which are concentric with the inner conical sleeve 2. This is mainly to provide stroke and limit for the telescopic piece 4 and prevent the telescopic piece 4 from moving radially. The upper part is connected to the fitting positioning cover 7 by bolts. The middle flat part is equipped with a brush head fixing plate 11 to fix the lower part of the brush head and prevent the brush head 5 from spreading out. The lower part of the skeleton sleeve 3 has six threaded holes and is connected to the base plate 6 by bolts to ensure that the telescopic piece 4 will not slip off accidentally.

[0034] The six telescopic plates 4 are designed in a circumferential direction to ensure that they have a certain strength to open the outer brush head 5. The overall eccentric design has the center of gravity at the bottom. By moving the core rod downward, the six telescopic plates 4 can be fully opened. When the core rod moves upward, the six telescopic plates fall back to their initial position by their own weight, thereby achieving the effect of opening the outer brush head 5 downward and closing the brush head upward.

[0035] The brush head 5 is made of a scouring pad and is installed on the outside of the frame sleeve 3. It is locked by the outermost clamp 13, which is equipped with an internal hex bolt. The brush head can be quickly replaced with just an internal hex wrench.

[0036] like Figure 1 and Figure 2 As shown, the core rod assembly 1 and the conical sleeve 2 are welded together by pins. A lifting handle is installed on the top of the core rod by threads for easy disassembly and assembly of the fixing pin. The lower part of the conical sleeve 2 is positioned by the base plate 6 pins to ensure concentricity. The telescopic plate 4 and the skeleton sleeve 3 are fitted onto the outside. The brush head 5 is fixed to the skeleton sleeve 3 by the clamp 13 and the brush head fixing plate 11 for easy disassembly and replacement of the brush head. The positioning sleeve 12 and the fitting positioning cover 7 are fixed to the fitting positioning plate 7 by screws. The operating handle 8 is connected to the fitting positioning plate 7 by threads. The lifting handle 9 is fixed to the connecting plate by upper and lower nuts. The quick-release pin 10 is fixed to the connecting plate by a steel wire rope to prevent accidental fall.

[0037] A method for using a cleaning tool for reactor mechanical seal ring nozzles includes the following steps:

[0038] 1) Assemble the reactor mechanical seal ring nozzle cleaning tool as a whole and test to confirm that the up and down movement is smooth and the brush head 5 can be opened.

[0039] 2) Use the lifting handle to position the reactor mechanical seal ring nozzle cleaning tool onto the reactor mechanical seal ring nozzle 14;

[0040] 3) Remove the quick-release pin 10 from the upper part of the reactor mechanical seal ring nozzle cleaning tool, lower the core rod to the lower limit position and insert the quick-release pin 10;

[0041] 4) Use the operating handle to rotate the entire tool to clean the reactor mechanical seal annulus nozzle;

[0042] 5) Add anhydrous ethanol for wet cleaning according to the actual working conditions on site;

[0043] 6) Wipe the sealing surface dry with a paper towel;

[0044] 7) Complete the cleaning and removal of the reactor mechanical seal ring nozzle cleaning tools.

Claims

1. A cleaning tool for the nozzle of a reactor mechanical seal ring, characterized in that: The core components include a core rod assembly, a conical sleeve, a skeleton sleeve, a telescopic plate, and a brush head. The core rod assembly is connected to the conical sleeve, which is installed below the core rod assembly. The skeleton sleeve is installed on the outside of the conical sleeve. The skeleton sleeve has a wedge-shaped groove in its circumferential direction that is concentric with the inner conical sleeve. The telescopic plate is inserted into the wedge-shaped groove in the circumferential direction of the skeleton sleeve and is connected to a fitting positioning cover. The brush head is installed on the outside of the skeleton sleeve. The telescopic plate is connected to the fitting positioning cover by bolts at the top. The brush head fixing plate is installed on the plane in the middle of the telescopic plate to fix the lower part of the brush head and prevent the brush head from spreading out. Six threaded holes are opened at the bottom of the skeleton sleeve and connected to the base plate by bolts. The telescopic plate has six pieces in the circumferential direction to ensure that it has a certain strength to open the outer brush head. The overall eccentric design has the center of gravity at the bottom. By moving the core rod assembly downward, the six telescopic plates can be fully opened. When the core rod assembly moves upward, the six telescopic plates fall back to the initial position by their own weight, achieving the effect of opening the outer brush head downward and closing the brush head upward. The brush head is fixed to the skeleton sleeve by a clamp and a brush head fixing plate; the positioning sleeve is fixed to the fitting positioning cover by a screw, and the operating handle is connected to the fitting positioning cover by a thread; The core rod assembly and the conical sleeve are welded together by pins. A lifting handle is installed on the top of the core rod assembly by threads. The bottom part of the conical sleeve is positioned by a base plate pin to ensure concentricity. A telescopic plate and a skeleton sleeve are fitted onto the outside. The brush head is made of a scouring pad; The conical sleeve has six wedge-shaped grooves of the same size in the circumferential direction. The main function of these grooves is to provide a driving force for the internal telescopic plates to ensure that they can move simultaneously, so that the outer brush head can be fully opened. The interior of the skeleton sleeve is hollow; Use the lifting handle to position the reactor mechanical seal ring nozzle cleaning tool onto the reactor mechanical seal ring nozzle; remove the quick-release pin on the upper part of the reactor mechanical seal ring nozzle cleaning tool, lower the core rod to the lower limit position and insert the quick-release pin. Use the operating handle to rotate the entire tool to clean the reactor mechanical seal ring nozzle.

2. The cleaning tool for reactor mechanical seal ring nozzles as described in claim 1, characterized in that: The conical sleeve has a groove in the center inside, which cooperates with the upper core rod assembly to form an integral unit.

3. A method of using a cleaning tool for a reactor mechanical seal ring nozzle as described in claim 1 or 2, characterized in that, Includes the following steps: 1) Assemble the reactor mechanical seal ring nozzle cleaning tool as a whole and test to confirm that the up and down movement is smooth and the brush head can be opened; 2) Use the lifting handle to position the reactor mechanical seal ring nozzle cleaning tool onto the reactor mechanical seal ring nozzle; 3) Remove the quick-release pin on the upper part of the reactor mechanical seal ring nozzle cleaning tool, lower the core rod to the lower limit position and insert the quick-release pin; 4) Use the operating handle to rotate the entire tool to clean the reactor mechanical seal annulus nozzle; 5) Add anhydrous ethanol for wet cleaning according to the actual working conditions on site; 6) Wipe the sealing surface dry with a paper towel; 7) Complete the cleaning and dismantling of the reactor mechanical seal ring nozzle cleaning tools.

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