JPH0611596A - Lifting device for internal pump - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent damage to the inside of the casing of the internal pump and the motor, and to facilitate repair work. [Structure] A screw rod 7 is connected to each of a pair of speed reducers 10 and 13. The motor cover 2 of the internal pump is attached to the screw rod 7 so as to be able to move up and down. A table 12 is installed between the pair of speed reducers 10 and 13. A pair of hoisting machines 16 are placed and fixed on the table 12. The wire rope 15 of this hoisting machine 16 is attached to the motor cover 2
Hook through hook 14 to.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevating device for an internal pump for use in maintenance and inspection of an internal pump attached to an improved boiling water reactor.

[0002]

2. Description of the Related Art In an improved boiling water reactor, an internal pump is used as a recirculation pump in the reactor. This pump requires propellers and shafts, diffusers and stretch tubes, motors and casings. Of these, the casing is integrated with the stub tube standing upright inside the furnace bottom by welding or the like, and is provided so as to extend outside the reactor pressure vessel.

At the time of repair in a regular inspection or the like, only the motor is taken out to the pedestal side and sent to the repair room by a service platform on the pedestal for repair. For others, take out the reactor water from the fuel exchange platform on the reactor and temporarily store it in a pool etc. for repair.

A conventional lifting device for an internal pump will be described with reference to FIG. Reference numeral 1 in FIG. 4 is a casing of the internal pump body, and shows a state in which the motor cover 2 is removed from below the casing 1. The motor shown in FIG. 6 is attached to the motor cover 2.

A first block 4 is assembled on both sides of a casing flange 6 of the casing 1, and a pair of two screw rods 7 are erected inside the first block 4.
The shaft portion at the tip of the screw rod 7 and the bearing of the shaft portion are provided in the first block 4.

This bearing bears both the radial and thrust loads of the screw rod 7. The first block 4 is supported by an upper clamp 5 via a pin (not shown), and the upper clamp 5 is provided with a casing flange 6
Conclude The shaft ends of the screw rods 7 are the first
It is supported by Block 4 of.

Similar to the upper clamp 5, a pair of lower clamps 8 are symmetrically provided on both sides of the motor cover 2, and the lower clamp 8 fastens the motor cover 2. The lower clamp 8 supports the second block 9 via a pin (not shown).

Although not shown, the second block 9 is internally provided with a nut having an internal thread to be fastened to a nut holder. When the screw rod 7 is screwed into the nut and the nut is rotated, the nut moves up and down. . The nut is screw-coupled to the screw rod 7 via a disc spring to form a so-called double nut type. The nut holder is supported on the lower clamp 8 by a pin.

The screw rod 7 is installed in the pedestal space inside the reactor containment vessel, and includes a first speed reducer 10 and a second speed reducer 10.
It is rotated by the speed reducer 13 of. That is, the pair of screw rods 7 are screwed with the second block 9 provided with the female screw of the motor cover 2, and are coupled to the output shafts of the two speed reducers 10 and 13, respectively.

When driving, the two speed reducers 10 and 13 are simultaneously operated, but the tip of the screw rod 7 is at the casing flange 6.
Also engages with the second block on the side surface of the bearing and bears thrust. A handle 11 is attached to the speed reducers 10 and 13 so that they can be driven electrically or manually.

During operation, however, the motor cover 2 to which the motor 26 is attached has the first and second blocks 4, 9
Going up or down through. There is a pedestal space under the platform under the internal pump, and all the motors 26 are attached / detached by the lifting device with the above-mentioned configuration, and are carried to / from the repair room on the service platform. .

Next, the overall structure of the internal pump will be described with reference to FIG. In FIG. 5, the diffuser 22 is installed in the hole of the diffuser seat that is provided between the inner wall of the reactor pressure vessel 17 and the outer wall of the shroud 18, and the boss portion of the diffuser seats on the stub tube 20.

The strut tube 23 is engaged inside the boss portion, but is screwed so as to pull the boss portion by the tightening nut 30 at the stepped portion of the casing 1. The stub tube 20 rises from the lower mirror 19 of the reactor pressure vessel toward the core and welds the casing 1 near its seat surface.

The casing 1 is integrated with the reactor pressure vessel 17, but the accommodating portion of the motor 26 has an enlarged diameter and projects outside the lower mirror 19 of the reactor pressure vessel 17. The secondary seal 32 in the casing 1 is provided under the tightening nut 30 and is attached to the shaft 25.
Seal the shaft circumference. When using, press the high pressure water around the shaft. A propeller 24 is fitted inside the diffuser 22, but the diffuser 22 is integrated with a shaft 25, and the shaft 25 passes inside the boss portion of the diffuser 22.

The stretch tube 23 vertically extends and stands up to the vicinity of the lower end opening of the casing 1. Key 29 is motor
It is engaged with the keyway on the rotor side of 26. The motor 26 encloses the inner and outer circumferences with a so-called can, and when in use, cooling water is forcedly supplied to cool. Rod 27 at the end of shaft 25
A thrust bearing is provided on the inner cylinder flange 38 engaged with.

The thick small flange 31 supports a needle bearing 34 which serves as a radial bearing at the lower end of the inner cylinder flange 38. The motor cover 2 is tightly fastened to the casing flange 6 by the studs 28 and sealed from the outside, and the thick small flange 31 is mounted. The flange surface of the thick small flange 31 is also sealed from the outside.

As described above, the seat surface of the stub tube 20, the secondary seal 32, and the motor cover 2 serve as the casing 1.
Is sealed, and cooling water constantly circulates around the motor can for cooling.

Next, the motor 26 will be described with reference to FIG. FIG. 6 is a vertical sectional view showing a state in which the motor 26 in FIG. 5 is attached to the motor cover 2. The transfer of the motor 26 is performed in the illustrated state. Second when attaching to the lifting device
The block 9 and the lower clamp 8 are attached to the side surface of the motor cover 2 in two symmetrical positions.

A so-called can-coated motor 26, which is surrounded by an inner cylinder 33 and an outer cylinder 35, is divided into a rotor and a stator, and a rotor side engages with a key 29 of a shaft 25 in a key groove 36.
The inner cylinder flange 38 is provided with a rod hole for anchoring the end of the shaft 25.

As described above, in the conventional lifting device, the two speed reducers 10 and 13 are electrically or manually driven, and the two screw rods directly connected to the respective output shafts are rotated to rotate the screw rods 7. The blocks 4 and 9 are screwed to raise these blocks 4 and 9, but the second block 9 is fixed to the motor cover 2, and the motor cover 2 is directly raised.

Since the motor 26 is compactly assembled on the motor cover 2, the propeller 24 in the casing 1 can be inserted into the casing 1 if it is directly above it.
It is key-locked to the shaft 25 of. When the motor 26 is pulled out, the rotation directions of the speed reducers 10 and 13 are reversed, and the motor cover 2 to which the motor 26 is attached is pulled out from the casing 1 and descends.

Since the speed reducers 10 and 13 are provided in the pedestal space under the platform below the reactor pressure vessel 17 and directly below the casing 1, the motor cover 2
Of the motor cover 2 and the motor 26 by removing the engagement between the second block 9 and the screw rod 7.
Is loaded on the platform side or the lifting device side.

[0023]

In the conventional lifting device for an internal pump, the screw rod 7 is bent because the screw rod 7 and the second block 9 are generally intersected with each other and the screw rod 7 is long. This flexure promotes the tilting of the motor 26 that is mounted high on the motor cover 2, and when the motor 26 directly goes in and out, it may deviate from the gap between the outside of the motor 26 and the inside of the casing 1 and come into contact with each other. If this does not proceed smoothly, there is a risk of developing until the motor 26 and the inside of the casing 1 are damaged. In order to eliminate this risk, it is important to freely swing the motor cover 2 and the motor 26 so that the contact with the casing 1 is smoothly changed.

In the method of transferring the motor of the internal pump by using an elevating device and descending it directly above or below the pedestal space, contact scratching of the casing with the motor poses a problem. Therefore, it is necessary to add equipment that can easily swing the motor side in response to the environment to the lifting device.

The present invention has been made to solve the above problems, and prevents the inside of the casing and the outside of the motor from contact scratches during repair work, thus facilitating the repair work of the internal pump. It is to provide a lifting device for a pump.

[0026]

According to the present invention, a screw rod is connected to each of a pair of speed reducers, and a motor cover of an internal pump is attached to these screw rods so as to be able to move up and down. A table is installed, a pair of hoisting machines are placed and fixed on the table, and hooks hooked on the motor cover of the internal pump are connected to the wire ropes of these hoisting machines.

[0027]

The two speed reducers are operated synchronously, and two hoisting machines are installed on the table that covers the gears, chain wheels, etc. used for their mechanical connection. During operation, the hooks at the ends of the wire ropes are engaged with the hooks embedded on the side surface of the motor cover.

The fitting position of this metal fitting is on the center line orthogonal to the center line of the block screwed with the screw rod and on the side surface of the motor cover. The wire ropes of the two hoisting machines are alternately wound up one by one, loosened two at a time, or wound up two at a time.

This means that the motor cover and the motor are first oscillated, then the motor cover and the motor are promised to be directly raised, and finally the motor cover and the motor are directly lowered. As described above, the motor cover can be easily attached to and detached from the casing by the screw rod, and abrasion or the like due to contact with the casing can be prevented.

For example, when mounting a motor cover with a motor mounted in a casing, when the motor cover on the screw rod approaches the casing inlet, the inclination of the motor is checked. It does not tilt in the direction of the center line of the screw rod, but tilts in the 90 ° phase direction, that is, in the direction of the center line of the hanging metal fittings, but the wire rope on the side where the tilt is corrected by using the hoisting machine under the two wire ropes. If you wind up and loosen the tilt side, the tilt will be corrected.

Generally, the motor cover is mounted on the casing, and the mounting is continued until the end unless unreasonable contact with the casing is confirmed. When the tip of the motor cover comes into contact with the casing flange, stop the rotation of the screw rod, separate the wire rope from the hook, and wind only the rope.

When the casing is pulled down, the wire rope on one side is loosened, and the other wire rope is wound up to correct the inclination and pulled down. In addition, when the tilt is corrected, the power for rocking the motor is required, and the hoisting machine is operated electrically, but after the tilt is taken, the hoisting machine can be manually wound or unwound with both machines. You may

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the lifting device for an internal pump according to the present invention will be described with reference to FIGS. FIG. 2 is a view on arrow AA of FIG. In FIG. 1, the same parts as those in FIG. 4 are designated by the same reference numerals.

That is, reference numeral 1 is a casing of the internal pump body, and 2 is a motor cover to which a motor is attached. A first block 4 is combined with both sides of a casing flange 6 attached to a lower portion of the casing 1, and a screw rod 7 is erected inside the first block 4, and a shaft of a tip of the screw rod 7 is provided. And a bearing for this shaft are provided in the first block 4.

This bearing bears both the radial and thrust loads of the screw rod 7. The upper clamp 5 is fastened to the casing flange 6 and supports the first block 4 via a pin (not shown).

The shaft end of the screw rod 7 is supported by the first block 4. The lower clamps 8 are provided on both sides of the motor cover 2 in a left-right symmetrical manner as in the upper clamp 5, and are fixed to the motor cover 2. Also,
A pair of second blocks 9 is also provided, and the second block 9 supported by the lower clamp 8 through a pin (not shown) has therein a nut having an internal thread to be fastened to a nut holder. A so-called double nut system is incorporated by screwing the screw rod 7 which is screwed through the nut and passed through it to the holder and is screwed to the male screw of the screw rod through the disc spring. The nut holder is supported by the clamp with a pin.

The hook 14 is wound up and unwound by the hoisting machine 16 installed below, and is anchored to the hanging metal fitting implanted on the side surface of the motor cover 2 by the metal fitting at the tip of the wire rope 15. The table 12 for fastening the pedestal of the hoisting machine 16 is provided on the coupling device for synchronously operating the first speed reducer 10 and the second speed reducer 13.

The wire rope 15 connected to the hook 14 is moored on the left and right as shown in the figure, and is provided so as to maintain the balance of the motor cover 2. Each wire rope 15 is a hoist 16
It can be wound up and unwound with the drum. The hoisting machine 16 is electrically operated to correct the imbalance. It can be operated manually during normal operation including rewinding. The output shaft of the speed reducer 10 is directly coupled to the screw rod 7 by a coupling, and can be manually driven as well as electrically driven.

Next, referring to FIG. 3, a method of repairing the internal pump by the internal pump elevating device having the above construction will be described. That is, the refueling service platform 41 is provided above the reactor pressure vessel 17 and is used for refueling. When fuel is not transferred, the hanger 40 is suspended from the platform 41 and used for repairing the internal pump.

The top cover 39 of the reactor pressure vessel 17 moves during the periodic inspection, and the head cover 42 of the shroud 18 also moves together with the separator inside the reactor pressure vessel 17.
The shroud 18 in the reactor pressure vessel 17 is erected by the shroud support. The shroud support has an opening below the diffuser 22 and serves as a circulating water channel.

A service platform 47 is provided below the screw rod 7, and a pedestal space is provided below the platform 47. The speed reducer 10 and the table 12 are installed on the pedestal floor. The screw rod 7 extends from the casing flange 6 to the speed reducer 10.

A rail 48 is attached to the outer side of the shroud 18, and the rail 48 is used as a guide for the hanger 40. Here, the suspending tool 40 suspended from the refueling service platform 41 during the periodic inspection is suspended between the shroud 18 and the inside of the reactor pressure vessel 17.

Then, with the guide of the rail 48, the diffuser
Put on the propeller 24 in 22 and grasp with the latching function of the lifting tool 40, and lift the propeller 24 and shaft 25 to lift the propeller 24.
It is temporarily placed in a pool, etc. Next, the tightening nut is removed, the diffuser 22 and the stretch tube 23 are taken out, and the diffuser 22 and the diffuser 22 are temporarily placed in a pool or the like.

On the other hand, the motor 26 is pulled out from the open end of the casing flange 6. In this case the casing flange 6
Then, the second block 9 and the lower clamp 8 are attached to the motor cover 2 and the screw rod 7 is screwed.

The motor 26 and the motor cover 2 are pulled downward from the casing 1 and the service platform 47 is pulled out.
And lift it with a crane 43. In that state, suspend it on the trolley 44, roll it over, and transfer it further by the trolley 44.
Carry it to 45 for repair.

At the time of reassembly, the diffuser 22 and the stretch tube 23 are suspended by a suspending tool 40, seated on the stub tube 20, and the end of the stretch tube 23 is tightened with a tightening nut. Next, the propeller 24 and the shaft 25 are mounted through the boss of the stretch tube 23. The end of the shaft 25 stands up to the vicinity of the casing flange 6.

The motor cover 2 to which the motor 26 is attached is taken out from the repair room 45 and mounted on the service platform 47 by the crane 43. Next, the motor cover 2 is placed on the elevating device and the speed reducers 10 and 13 are driven to mount the motor 26 in the casing 1. The casing flange 6 and the motor cover 2 are tightened, the shaft 25 and the inner cylinder flange 38 are connected by the rod 27 through the hole of the thick small flange 31, and the thick small flange 31 is fastened to complete the reassembly.

By the way, the internal pump is stopped during the periodic inspection. Some of the stopped internal pumps will be repaired. The repair starts with decomposition and the reactor water is full, but the fuel is transferred first, so naturally the top cover, dryer, and head cover with separator are transferred.

Upon disassembly, the upper clamp 5 and the first block 4 are attached to the casing flange 6 to support the tip shaft portion of the screw rod 7. At the same time, the screw rod 7 is screwed into the lower clamp 8 of the motor cover 2, the nut holder inside the second block 9 and the pressing nut.

The lowermost end of the screw rod 7 is coupled to the output shaft of the speed reducer. Hook the tip hook 14 of the wire rope 15 of the hoisting machine 16 on the hanging metal fitting of the motor cover 2. First, the small flange of the motor cover 2 is opened and the rod at the tip of the shaft and the inner cylinder flange are disengaged, and the stud is loosened to free the motor cover 2.

The speed reducers 10 and 13 are driven to rotate the screw rod 7. The nut side of the motor cover 2 is lowered by the rotation of the screw rod 7, and the motor cover 2
Is pulled out from the casing 1. The two hoisting machines 16 on the table 12 work on the take-up side, but if a curb occurs between the outside of the motor 26 and the inside of the casing 1 on the way, one hoisting machine
Stop winding 16

In this case, since the inside of the casing 1 cannot be seen, when the casing flange 6 and the flange surface of the motor cover 2 are viewed in parallel, the winding on the side where the opening is large is stopped. After returning to equilibrium, restart the winding that was stopped again. Since these adjustments are made, there is no need to worry about pulling out the motor cover 2 by stopping the screw rod each time.

When the motor cover 2 is pulled down to the service platform 47, the motor cover 2 is replaced with the service platform 47, and the second block 9 for the screw rod 7 and the clamp 8 are removed from the side of the flange of the motor cover 2 and screwed. Cut off the edge with rod 7.

After being transferred to the other side by the platform, it is hung by a crane and overturned on the carriage, for example, the motor cover 2
The mounted motor 26 is laid down and transported by truck to the repair room for repair. On the other hand, on the casing 1 side, a sealing flange is brought into contact with the casing flange 6 for fastening and sealing.

Then, the casing 1 is filled with fresh water,
Release the pressure on the secondary seal 32. Next, the suspending metal is suspended from the fuel exchange service platform 41 on the reactor, suspended between the top guide flange and the inner wall of the reactor pressure vessel 17, and the suspension 40 is propelled by the propeller 24 using the outer rail 48 of the shroud 18 as a guide. Attach it to the hanging bracket of and lift it.

The propeller 24 and the shaft 25 are temporarily stored in a state that the propeller 24 and the shaft 25 are connected on a shelf on the core side or the pool side. On the casing side, a blanket block is placed on the engaging portion of the stretch tube 23 within the boss of the diffuser 22 from which the shaft 25 of the diffuser 22 has slipped out, and a load is applied to the diffuser 22 and sealed with a sticky packing on the back side of the block.

Then, the fresh water in the casing 1 is drained, the secondary seal 32 and the tightening nut 30 are removed, and the fresh water is filled in the casing 1 again. The blanket block is picked up on the upper side of the furnace, and then the diffuser 22 is also picked up, and the diffuser 22 and the stretch tube 23 are temporarily stored on a storage rack in an integrated state.

Again, the blind lid is placed on the stub tube 20, the clean water in the casing 1 is drained, and the sealing flange of the casing is removed. If necessary, stub tube 20 and casing 1
Check the welding etc.

After that, the casing 1 is filled with fresh water with a sealing cover, and the diffuser and the stretch tube which have been repaired are suspended from the furnace and mounted on the stub tube 20 and the minimum diameter portion of the casing 1.

Again, the blanking block is loaded on the engaging portion of the stretch tube 23 in the boss of the stub tube 20, the fresh water in the casing is drained, the tightening nut of the stretch tube is tightened, and the secondary seal is attached. Fill the casing with a sealed cover and fill it with fresh water.

Next, the propeller 24 and the shaft 25, which have been repaired, are fitted into the boss of the diffuser 22 and the stretch tube 23 from above the furnace, and then the secondary seal 32 is pressurized. Again, drain clean water and open the airtight cover. The motor cover 2 is transferred from the repair room by a trolley, suspended by a crane, loaded on the lower platform, transferred on the platform, and combined with the screw rod 7.

That is, the speed reducer 1 in which the second block 9 and the lower clamp 8 are attached to the side surface of the flange portion of the motor cover 2 and are screwed to the two screw rods 7
0 and 13 work and the two hoisting machines 16 rewind. When the outside of the motor 26 on the motor cover 2 rubs against the inside of the casing 1, stop rewinding one of the hoisting machines.

Then, in the wound state, the flange portion of the motor cover 2 and the casing flange 6 are balanced. While balancing, the motor 26 is fitted in the casing 1 and the flange portion is fastened. Next, thick small flange
Open 31 and use rod 27 to the end of shaft 25 and inner cylinder flange
38 is connected and the small thick flange 31 is sealed again. Reassembly is completed by the above operation. After that, a test run is done and the repair is over.

[0064]

According to the present invention, when a motor is mounted in or pulled out from the casing of an internal pump, two hoisting machines are installed on the screw rod to perform cooperative operation. As a result, it is not necessary to stop the operation of the conventional screw rod each time and correct the motor on the motor cover that is tilted to one side. In addition, the pulling force using the wire rope allows the motor of the internal pump to be pulled out and reattached extremely smoothly. Further, since it is not necessary to always arrange an operator around the casing during the work, it is advantageous in radiation work.

[Brief description of drawings]

FIG. 1 is an external view showing an embodiment of an elevating device for an internal pump according to the present invention.

FIG. 2 is an external view as seen from the direction of arrow AA in FIG.

FIG. 3 is a schematic diagram showing a usage state of the lifting device for an internal pump in FIG.

FIG. 4 is an external view showing a conventional lifting device for an internal pump.

5 is a vertical cross-sectional view showing the internal pump in FIG.

6 is a vertical sectional view showing a motor cover and a motor in FIG.

[Explanation of symbols]

1 ... Casing, 2 ... Motor cover, 3 ... Cap,
4 ... 1st block, 5 ... Clamp, 6 ... Casing flange, 7 ... Screw rod, 8 ... Lower clamp, 9
… Second block, 10… First reducer, 11… Handle,
12 ... Table, 13 ... Second reducer, 14 ... Hook, 15 ... Wire rope, 16 ... Hoisting machine, 17 ... Reactor pressure vessel, 18 ... Shroud, 19 ... Bottom mirror, 20 ... Stub tube, 21 ... Support, 22 ... Diffuser, 23 ... Stretch tube, 24 ...
Propeller, 25 ... Shaft, 26 ... Motor, 27 ... Rod,
28 ... Stud, 29 ... Key, 30 ... Tightening nut, 31 ... Thick small flange, 32 ... Secondary seal, 33 ... Inner cylinder, 34 ... Needle bearing, 35 ... Outer cylinder, 36 ... Keyway, 37 ... Thin Small flange, 38 ... Inner cylinder flange, 39 ... Top cover, 40 ... Lifting equipment, 41 ... Fuel exchange service platform, 42 ... Head cover, 43 ... Crane, 44 ... Truck, 45 ... Repair room, 46 ... Reactor containment vessel , 47 ... Service platform, 48 ... Rails.

 ─────────────────────────────────────────────────── ─── 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 screw rod is connected to each of a pair of speed reducers, and a motor cover of an internal pump is attached to these screw rods so as to be able to move up and down.
A table is installed between the pair of speed reducers, a pair of hoisting machines is placed and fixed on the table, and a hook for hooking the motor cover of the internal pump is connected to the wire ropes of these hoisting machines. An elevating device for an internal pump, characterized in that