JPH06138280A - Cleaner for internal pump - Google Patents

Abstract

PURPOSE:To provide an internal pump cleaner which can brush a stretch tube assembled, accurately position its brush and be remote operated. CONSTITUTION:A hollow lower support 22 is mounted to a lower flange 40 attached to the lower end opening of a casing 1 and a stanchion 20 is erected on the lower support 22. A center cylinder 21 is mounted to the upper end of the stanchion 20 and an upper support 35 is erected at the upper end of the center cylinder 21. A rotating shaft 36 is erected inside the upper support 35, an upper cylinder 7 is mounted to the rotating shaft 36, a timbering plate 26 is mounted to the upper cylinder 7, and a slipping element 5 for engagement with the groove of a stretch tube 3 is mounted to the timbering plate 26. A top board 32 is mounted to the side face of the rotating shaft 36 and a cylinder 9 provided with a brush 8 for cleaning the thread groove of the stretch tube 3 is erected on the top board 32. A labyrinth 72 is formed in the cylinder 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal pump cleaning tool for cleaning the thread groove of a stretch tube of an internal pump adopted in an improved boiling water reactor.

[0002]

2. Description of the Related Art Conventionally, a boiling water reactor is provided with a jet pump in a reactor pressure vessel, a part of the reactor water in the reactor pressure vessel is taken out, pressurized by a recirculation pump, and jetted as driving water. It was sent to a pump, and this jet pump was recirculating the reactor water through the core.

However, such a structure has problems that the structure is complicated and that the pipe connecting the jet pump and the recirculation pump becomes the boundary of the reactor water.

In order to solve such a problem, an improved boiling water reactor equipped with an internal pump 59 as shown in FIGS. 4 and 5 has been developed. That is, the reference numeral in FIG.
49 indicates a reactor pressure vessel, and this reactor pressure vessel
A shroud 44 is provided in 49, and a core 56 in which a large number of fuel assemblies are arranged is accommodated in the shroud 44.

A plurality of, for example, 10 internal pumps 59 are provided around the bottom of the reactor pressure vessel 49. The reactor water in the reactor pressure vessel 49 descends in a downcomer formed between the outer peripheral surface of the shroud 44 and the inner peripheral surface of the reactor pressure vessel 49, and is sent below the reactor core 56 by an internal pump 59. And flows into the core 56 from below.

The reactor water that has flowed into the core 56 boils due to the heat of the nuclear reaction and flows upward as a two-phase flow of water and steam. This two-phase flow of water and steam is separated into water and steam by a steam separator 53, and the separated steam is steam dryer 52.
After the moisture is removed by, the high pressure steam pipe 54 sends the moisture to a turbine (not shown) or the like.

The water separated from the turbine through the condenser is sent to the core 56 again by the internal pump 59 together with the water supplied from the water supply pipe 55.

A plurality of reactor pressure vessels 49 (about 200
Control rod drive mechanism 57 is provided, and the control rod drive mechanism 57 inserts or pulls out a control rod (not shown) into the core 56 to control the reactivity of the core 56. Has been done. In the figure, reference numeral 42 is a diffuser, 43 is an impeller, and 58 is a drive mechanism flange.

As shown in FIG. 5, the internal pump 59 comprises a pump portion 59a inside the reactor pressure vessel 49 and a motor portion 59b outside the reactor pressure vessel 49, and the pump portion 59a comprises a diffuser 42 and an impeller 43. Has been done. The diffuser 42 is a stub tube projecting from the bottom of the reactor pressure vessel 49 by the stretch tube 3 and the tightening nut 46.
It is fixed to the tip of 73.

Reference numeral 1 is a casing that surrounds the motor portion 59b. The casing 1 is welded to the reactor pressure vessel 49 and is provided so as to project from the bottom surface. A water immersion motor 50 is housed in the casing 1.
A motor cover 51 is attached to the lower end of the motor 50.

The motor cover 51 abuts against the lower surface of the casing 1 and is tightened and fixed by a nut 2a screwed to the stud 2, thereby maintaining liquid tightness and fixing the motor 50 to the casing 1. The motor 50 and the impeller 43 are connected by a shaft 45, and the impeller 43 is driven via the shaft 45. In the figure, reference numeral 10 is a leak water pipe, 47 is a high-pressure water pipe, and 48 is a water supply / drainage pipe.

FIG. 6 shows the internal pump 59 shown in FIG.
1 shows an elevating device of an internal pump handling device using a screw rod 62 for removing the motor cover 51 of FIG. 1 and attaching and detaching the motor 50, the shaft 45, the tightening nut 46 and the like in the casing 1.

That is, in FIG. 6, a pair of diametrically symmetric bearing boxes 60 are provided outside the flange portion of the casing 1 to accommodate the shaft end portion of the screw rod 62. Reference numeral 40 in FIG. 6 denotes a lower flange, which is the lower flange.
The reference numeral 40 is to be attached instead of the motor cover 51 when disassembling, repairing or inspecting the internal pump.

Nuts 61 are provided on both sides of the lower flange 40 so as to face bearing boxes 60 provided at the lower end of the casing 1.
Are fixed, the nut portion 61 is screwed into the screw portion of the screw rod 62, and rises and falls according to the rotation of the screw rod 62.

The rotation of the screw rod 62 is performed by coupling the end of the screw rod 62 to the output shaft of the motor 63 with a speed reducer. Rotate two 62 to raise and lower the lower flange 40.

[0016]

When disassembling the internal pump, when repairing and curing the stretch tube 3 alone, it is common to clean the thread groove, but if a problem occurs during assembly, for example, In the case where the tightening is not enough even when tightened with the specified torque, there is a problem that inspection is troublesome in a narrow inner part of the casing 1.

Further, if the operation is performed in a state where the inspection is insufficient, the packing surface with the diffuser 42 on the stretch tube 3 becomes loose, and the reactor water leaks. Similarly, after tightening the tightening nut 46, the lock sleeve is used to prevent rotation, but even in the case of screwing that is not at right angles to the axis, the lock sleeve tends to be incompletely mounted, and the locking effect cannot be expected.

Therefore, it is necessary to clean the thread groove of the stretch tube 3 before attaching the tightening nut 46. The thread groove of the stretch tube 3 can hardly be visually inspected, and the torque during or immediately after the use of the tightening nut 46, the tightening condition of the tightening nut 46, and the reactor pressure vessel 49 from above. If a defect is found due to the presence or absence of leaked water, and the stretch tube 3 is removed and inspected again, there is a problem in that it requires a lot of time and labor because the repair process comes back.

The present invention has been made to solve the above-mentioned problems, and it is possible to directly brush a stretch tube in a narrow space in a casing in an assembled state with a tightening nut removed, and a thread groove portion of the stretch tube is provided with a brush. An object of the present invention is to provide a cleaning tool for an internal pump, which can be accurately positioned and can be operated remotely.

[0020]

According to the present invention, a hollow lower support is attached to a lower flange, a hollow cylindrical support is erected in the lower support, and a hydraulic pipe is connected to the lower end of the support and the support of the support is provided. A central cylinder extending from the upper end to the outer surface is provided, a hollow cylindrical upper support is connected to the upper end of this central cylinder, a rotary shaft is erected inside this upper support, and a gear is attached to the outer surface of this rotary shaft. , A drive motor for rotating the gear is provided, and a top plate is attached to the rotary shaft above the gear via a collar, rising from the outer peripheral surface of the top plate and a lower outer peripheral surface of the stretch tube in the internal pump casing. A cylinder facing each other is provided, and a brush that abuts the thread groove of the stretch tube is attached to the inner surface of the cylinder, and the interface is attached to the lower portion of the outer surface of the cylinder. A labyrinth seal in contact with the inner surface of the null pump casing is provided, a drain tube is provided on the top plate, an upper cylinder is connected to the rotating shaft on the top plate via a collar, and a piston is provided in the upper cylinder via a spring. Insert the shaft, attach the connector to the upper end of this piston shaft, connect the support plate to the upper end of the upper cylinder,
Sliding elements whose outer surface locks the inner surface of the stretch tube are slidably provided on both ends of the support plate via pressing flanges, and the sliding element and the connecting element can be rotated by pins via arms. It is characterized by being connected to.

[0021]

The cleaning tool according to the present invention is carried out by the elevating device using the screw rod shown in FIG. 6 provided directly below the casing of the internal pump. That is, the cleaning tool erected on the lower flange is fed into the inside of the casing by a screw rod, and the lower opening end of the casing is sealed by the lower flange.

After that, pressurized water is fed into the cylinder at the central portion to further raise the rotary shaft, pressurized water is fed into the upper cylinder, the piston shaft is lowered, and the slider is extended to both blades and brought into contact with the inside of the groove of the stretch tube.

The upper cylinder is a piston supported by a spring, one circuit for pressurizing and depressurizing the upper part of the piston, two circuits for ascending and descending the central cylinder, and one circuit for the drain tube for the drain tank. In addition, the leaked water from the labyrinth of the leaked water on the lower flange is pulled out from the plug.

A joint is provided in each of the pipe lines so that the pipe lines can be attached and detached after the lower flange and the casing flange are stud-joined. In addition, the cable of the drive motor is also taken out from the lower flange, and ON / OFF control is performed in a separate terminal box. A screw rod is used for loading and mounting, both upper and center cylinders are used for positioning, brushing is performed with a drive motor, and drainage is performed with a drainage tank.

Then, the above-mentioned counter pressure is applied to the central cylinder, and all the components on the central cylinder are lowered to lock the slider to the end edge of the groove. Next, the cylinder is rotated by the drive motor, and leak water is poured from the leak water pipe and stored in the drain tank. Brush the stretch tube threads with a brush.

In this case, a leak water pipe is used to inject water into the brush portion to wash away the dirt generated from the thread groove, collect it in the drain tank, and drain it to the radioactive waste liquid storage tank if necessary.

After the brushing is finished, the central cylinder once rises, the water pressure in the upper cylinder is released, the spring is returned in the central cylinder to retract the slider, and then the water pressure in the central cylinder is released and returned at the time of mounting. . Take the cleaning tool out of the casing again with the screw rod, and cure the drain tank if necessary.

In this way, the invention is all mechanized and can be carried out remotely without polluting the surroundings of the casing.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cleaning tool for an internal pump according to the present invention will be described with reference to FIGS. Figure 1
2 is an overall configuration diagram of this embodiment, FIG. 2 is an enlarged detail showing an upper portion of FIG. 1, and FIG. 3 is an enlarged detail showing a lower portion of FIG.

In FIG. 1, a lower flange 40 is watertightly fastened to a lower end opening of the internal pump casing 1 via a stud 2 and an O-ring 71. As shown in FIG. 3, a hollow lower support 22 is fixed to the upper surface of the lower flange 40 by bolting, and the pillar 20 is erected by penetrating the inside of the lower support 22. The lower end of the pillar 20 has a double nut 41. It is fixed to the lower flange 40 by.

A hydraulic pipe 24 is connected to the lower end of the column 20. A piston portion is formed at the upper end of the column 20, and a central cylinder 21 is crowned. In addition, in FIG. 3, the cable 23
Lower flange 40 through presser foot 66, rubber bushing 67
And a joint 69 is provided at the lower part of the cable 23. In FIG. 1, 70 is a plug provided on the lower surface of the lower flange 40.

The central cylinder 21 is provided with first and second hydraulic pipes 17, 18. The column 20 is supported by the lower support 22. Drive motor on the center cylinder 21
19 and aquarium 15 are installed. The cable 23 attached to the lower flange 40 is for the drive motor 19. The drain pipe 16 is for the drain of the water tank 15. In addition, drainage pipe 16, hydraulic pipe 17,
Each of the 18 and 24 has its own joint 68.

A drive motor 19 is attached to the main plate 14, and a water tank 15 is also attached. The water channel 13 is a cylinder fixed on the main plate 14, and the bottom side is inclined so that the dirty water is poured into the water tank 15.

The direct coupling gear 12 is key-locked to the motor shaft end, but meshes with the gear 11. The gear 11 is key-locked to a rotating shaft 36 which is freely rotatable on the central cylinder 21. The cylinder with brush 9 is fixed to the rotary shaft integrally with the top plate 32. The upper cylinder 7 contains a piston shaft 28 supported by a spring 29, and has a connector 4 screwed onto the upper end of the piston shaft 28.

The connector 4 is joined by the lever 6 to the slider 5 and the connector 4 with the pin 25. The slider 5 is attached to the edge of the support plate 26 via a holding flange 27 so as to be slidable in the horizontal direction. In FIG. 2, the slider 5 is shown in a state where it is engaged with the edge of the groove of the stretch tube 3 and is ready for brushing.

Wash water flows from the leak water pipe 10 into the portion of the brush 8. Stretch tube 3 inside casing 1
And a brush 8 is formed with a stretch tube end screw, and brushing is performed when the brush cylinder 9 rotates.

The pin 25 connects the slider 5 and the connector 4 via the lever 6. The end of the piston shaft 28 in the upper cylinder 7 and the connector 4 are screwed together. The spring 29 supports the piston shaft 28. The opening of the upper cylinder 7 has an end face flange 7a.
The end face flange 7a is formed with an absorption port 31 to effectively bend and stretch the spring 29.

A collar 30 is provided between the rotary shaft 36 and the upper cylinder 7 so that the upper cylinder 7 can be supported by the rotary shaft 36 during floating. The shaft end of the piston shaft 28 is slidably fitted into the upper opening of the rotary shaft 36. The outer side of the end of the rotary shaft 36 is used when the cylinder is pulled down by engaging with the end surface flange of the cylinder with a snap ring or the like.

The top plate 32 is bolted to the flange of the brush cylinder 9, and the top surface of the top plate 32 has a conical shape in a mountain shape, and a plurality of drain tubes 33 are provided in the hollow. . The water channel 13 is opened so that the drain tube 33 can rotate inside, but the sewage is guided by the inclination of the bottom plate and passes through the through-hole of the main plate 14 so that washing water and sewage fall into the water tank 15.

A labyrinth 72 is formed outside the brush cylinder 9 and below the leak water pipe 10 which is seen from the casing 1 side. The labyrinth 72 is provided to send the leak water to the brush 8 side. Color of gear 11 and top plate 32
Reference numerals 34 are for fixing the top plate 32 and the gear 11 to the rotary shaft 36, respectively.

The direct coupling gear 12 is bolted and key-locked to the output shaft 37. The drive motor 19 is fixed to the main plate 14 and the central cylinder 21. The upper support 35 is the rotation axis
It also functions as 36 bearings and reinforcement. The rotary shaft 36 is seated on the central cylinder 21 but is not fixed but rotatable, and the upper support 35 is fixed.

The end of the rotary shaft 36 is allowed to rotate by a snap ring or the like, but it is prohibited to float. The support plate 38 is the water tank 15
, But is fixed to the central cylinder 21. The drainage pipe 16 is a drainage pipe that guides the dirty water in the water tank 15 to a radioactive waste liquid storage tank in some cases. The support column 20 is inserted into the central cylinder 21 to form a piston portion.

When water pressure is applied to the top and bottom of the piston, the column 20 moves up and down. When the supporter 20 is raised, the slider 5 is projected, and when it is lowered, the slider 5 engages with the edge of the groove of the stretch tube 3 as shown in FIG. The column 20 is a hollow cylinder and is fixed to the lower flange 40 with a nut 39 and a double nut 41.

The lower support 22 is fixed to the lower flange 40 by flange fastening. The penstock 24 is connected to the hollow portion of the column 20. The cable 23 is for the drive motor, the drainage pipe 16 is for the water tank, and the water pressure pipes 17 and 18 are for the central cylinder. Both are equipped with a simple non-return type detacher, and other pipes are easy as needed. Is installed in.

Next, an example of using the cleaning tool for the internal pump will be described. The modified boiling water reactor will be inspected annually. During this periodic inspection, all components are inspected for repair and curing, including replacement and improvement of life parts.

At this time, the internal pump 59 is, for example, 10
Of those installed, several will be disassembled, inspected, and maintained. Of the components of the internal pump 59, the impeller 43 and the shaft 45 are taken out or inserted as a unit. The diffuser 42, the stretch tube 3 and the motor 50 are also taken out and inserted together.

Therefore, the auxiliary hoist of the service platform or the like is used on the furnace, and the service platform on the lower bottom is used on the pedestal side, and the components of the internal pump are handled with dedicated tools.

For example, the impeller for taking out components
43 and the shaft 45 are taken out, a blind plug is sealed inside the boss of the diffuser 42, the motor 50 is taken out, the secondary seal is removed, and the tightening nut 46 of the stretch tube 3 is taken out. The thread groove at the end of the stretch tube 3 can be cleaned.

That is, a drive device for the screw rod 62 is provided right below the casing 1, and two screw rods 62 are installed between the casing 1 and the bearing box 60. The nut portion 61 of the lower flange 40 of the cleaning tool is engaged with this screw rod 62, and the motor 63 with reduction gear and the coupling machine for synchronization.
The other speed reducer is simultaneously operated via 64 to rotate the two screw rods 62.

With all the components of the cleaning tool mounted on the lower flange 40, insert the lower flange into the casing,
And with studs, open end of casing 1 and lower flange
40 and the casing 1 is sealed. Lower flange 40
Drain pipe 16, penstock 17, 18, 24 and cable are on the lower side of
Since the connection fittings of 23 are visible, connect each pipe and wiring.

Thereafter, the central cylinder 21 is pressurized from the hydraulic pipe 17 to raise the central cylinder 21 once, and the upper support 35 and the upper cylinder 7 on the central cylinder 21 and the piston shaft 28 are supported at the shaft ends. The slider 5 pulled up by the work plate 26 and the spring 29 bearing is raised.

At the same time, the gear 11 on the upper support 35 and the inner rotary shaft 36 also rise. Further, the top plate 32 and the cylinder with brush 9 also rise at the same time. On the other hand, the main plate 14 and the water tank 1
5, the drive motor 19 and the like also rise together with the central cylinder 21. When the stroke of the central cylinder 21 is completed, the pressurized water is sent from the penstock 24.

Water pressure is applied to the upper surface of the piston portion of the piston shaft 28 through the insides of the support column 20 and the rotary shaft 36, and the spring
29 is contracted and only the piston shaft 28 is lowered, the lever 6 is pulled and the sliders 5 project to both sides, and the stretch tube 3
Abut the bottom edge of the groove.

Next, pressure water is sent from the water pressure pipe 18 to
When the return water is drained from the central cylinder 21, the central cylinder 21 descends again, and the slider 5 also protrudes through the rotary shaft 36 along with the above-mentioned components and descends to engage with the edge of the groove of the stretch tube 3. To do.

In this state, the cable 23 is energized, the drive motor 19 is rotated, the top plate 32 and the brush cylinder 9 are rotated by the rotary shaft 36 via the direct coupling gear 12 and the gear 11, and the stretch tube 3 is tightened with a brush. Brush the thread groove for the attached nut.

At this time, when washing water is flown from the leak water pipe and applied to the brush portion, the dirty water from the brush is guided from the drain tube 33 to the water tank 15. If necessary, it is poured into the radioactive waste liquid storage tank via the drain pipe 16. When the brushing is completed for the scheduled time, the drive motor 19 is stopped.

Then, a counter pressure is applied to the central cylinder 21,
The slider 5 is lifted to release the pressure on the upper cylinder 7, the slider 5 is retracted, and then the pressure on the central cylinder 21 is released again to return the components to the initial state and to collect the accumulated water on the lower flange 40. The lower wiring pipe of the lower flange 40 is removed.

Then, finally, the engagement with the screw rod 62 is confirmed, the stud is removed, and the screw rod 62 is operated to pull out the lower flange 40 and the cleaning tool mounted thereon.

[0059]

According to the present invention, the stretch tube can be directly brushed in a narrow space in the casing with the tightening nut removed, and the brush can be accurately positioned in the thread groove of the stretch tube. Can be operated remotely.

Therefore, by using the cleaning tool according to the present invention, the corrosion resistance of the stretch tube is improved and the correct engagement of the screw is guaranteed, and the actual value of the lead of the tightening nut and the surface control value of the torque are obtained. Has the advantage that it can be trusted as the effective value of the tightening nut and is useful for management.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a partially cutaway embodiment of a cleaning tool for an internal pump according to the present invention.

FIG. 2 is an enlarged vertical cross-sectional view showing the upper portion of FIG.

FIG. 3 is a vertical cross-sectional view showing a lower portion of FIG. 1 in an enlarged manner.

FIG. 4 is a vertical sectional view showing an improved boiling water reactor for explaining the present invention.

FIG. 5 is an enlarged vertical sectional view showing the internal pump in FIG.

6 is a configuration diagram showing a lifting device used for assembling the internal pump in FIG.

[Explanation of symbols]

1 ... Casing, 2 ... Stud, 3 ... Stretch tube, 4 ... Connector, 5 ... Slider, 6 ... Lever, 7 ... Upper cylinder, 8 ... Brush, 9 ... Brush cylinder, 10 ... Leak water pipe, 11 ... Gear , 12 ... Directly connected gear, 13 ... Water channel, 14 ... Main plate, 15
... water tank, 16 ... drain pipe, 17,18,24 ... water pressure pipe, 19 ... drive motor, 20 ... post, 21 ... central cylinder, 22 ... lower support, 23 ... cable, 25 ... pin, 26 ... supporting plate , 27 ... Retaining flange, 28 ... Piston shaft, 29 ... Spring, 30 ... Collar, 31
… Breathing mouth, 32… Top plate, 33… Drain tube, 34… Collar, 35… Top support, 36… Rotation axis, 37… Output shaft, 38…
Support plate, 39 ... Nut, 40 ... Lower flange, 41 ... Double nut, 42 ... Diffuser, 43 ... Impeller, 44 ... Shroud, 45 ... Shaft, 46 ... Tightening nut, 47 ... High pressure water pipe, 48
… Water supply and drainage pipe, 49… Reactor pressure vessel, 50… Motor, 51…
Motor cover, 52 ... Steam dryer, 53 ... Steam separator, 54
… High-pressure steam pipe, 55… water supply pipe, 56… core, 57… control rod drive mechanism, 58… drive mechanism flange, 59… internal pump, 59a… pump part, 59b… motor part, 60… bearing box, 61… Nut part, 62 ... Screw rod, 63 ... Reducer motor, 64 ... Synchronous coupling machine, 65 ... Reducer, 66 ... Retainer, 67 ... Rubber bushing, 68,69 ... Fitting, 70 ... Plug, 71 ... O Ring, 72… Labyrinth, 73… Stub tube.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Watanabe 4-7-7 Shiba, Minato-ku, Tokyo Aitel Technical Service Co., Ltd.

Claims (1)

[Claims] 1. A hollow lower support is attached to a lower flange, and a hollow cylindrical support is erected in the lower support.
A central cylinder extending from the upper end to the outer surface of the strut is connected to the lower end of the strut, and a hollow cylindrical upper support is connected to the upper end of the central cylinder.
A rotary shaft is erected inside the upper support, a gear is attached to the outer surface of the rotary shaft, a drive motor for rotating the gear is provided, and a top plate is attached to the rotary shaft above from the gear via a collar. , A cylinder that rises from the outer peripheral surface of the top plate and faces the lower outer peripheral surface of the stretch tube in the internal pump casing is provided, and a brush that contacts the thread groove of the stretch tube is attached to the inner surface of the cylinder, and the outer surface of the cylinder is attached. A labyrinth seal in contact with the inner surface of the internal pump casing is provided in the lower part, a drain tube is provided in the top plate, an upper cylinder is connected to the rotary shaft on the top plate via a collar, and a spring is provided in the upper cylinder. Insert the piston shaft through the, attach the connector to the upper end of this piston shaft, and support the upper end of the upper cylinder. And a sliding element whose outer surface locks the inner surface of the stretch tube is slidably provided at both ends of the support plate via pressing flanges, and the sliding element and the connecting element are pinned via an arm. A cleaning tool for an internal pump, which is rotatably connected with.