JP3462802B2 - Descaler - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for cleaning the inside of a steam generator of a pressurized water nuclear power plant, and more particularly to an apparatus for removing scale adhering to a heat transfer tube supporting hole of the steam generator.

[0002]

2. Description of the Related Art As shown in FIG. 8, a steam generator used in a pressurized water nuclear power plant has a large number of heat transfer tubes 2 curved in a U shape and a heat transfer tube support for supporting these heat transfer tubes 2. The heat transfer tube support plate 1 is provided with a plurality of oval flow holes 3 and a large number of clover-shaped heat transfer tube support holes 1a (see FIG. 9).
(See) has been drilled. In such a steam generator, a gap is formed between the heat transfer tube 2 and the heat transfer tube support hole 1a, and the secondary coolant flows in this gap, which is advantageous in that the local concentration of corrosion products can be prevented. Have However, the scale contained in the secondary coolant may adhere to the heat transfer tube support holes 1a, and the scale attached to the heat transfer tube support holes 1a may hinder the flow of the secondary coolant.

Therefore, in order to remove the scale attached to the heat transfer tube support hole 1a of the steam generator, a scale removing device as shown in FIG. 8 has been developed. This scale removing device includes a scale removing mechanism 9 for spraying high pressure water to the heat transfer tube supporting hole 1a of a steam generator to remove scale adhering to the heat transfer tube supporting hole 1a, and this scale removing mechanism 9
It is equipped with a lifting cylinder 8 for lifting and lowering, and a carry-in mechanism 14 for carrying the scale removing mechanism 9 and the lifting cylinder 8 into the steam generator. The carry-in mechanism 14 is a moving table (carry-in cart) 7 for carrying the scale removing mechanism 9 and the lifting cylinder 8 into the steam generator.
It has a guide rail 6 for guiding the moving table 7 into the steam generator, and a manual feed mechanism 12, and the lifting cylinder 8 has a horizontal axis on a fixed base provided on the moving table 7. It is rotatably connected via. Further, the scale removing device shown in FIG.
The manual winch 11 winds the wire 10 connected to the lifting cylinder 8 to vertically raise the lifting cylinder 8.

When the scale adhering to the heat transfer tube supporting hole 1a is removed by using such a scale removing device, first, the guide rail 6 is steamed from the inspection manhole 5 formed in the steam generator body 4. After being inserted horizontally into the generator, the manual feed mechanism 12 is operated to move the movable table 7 to a position below the flow hole 3. Next, after manually raising and lowering the lifting cylinder 8 by operating the raising / lowering manual winch 11, the raising / lowering cylinder 8 is operated to raise the scale removing mechanism 9 to a predetermined position. Then, from the high-pressure water jet nozzle of the scale removing mechanism 9 to the heat transfer tube support hole 1
The scale attached to the heat transfer tube support hole 1a is removed by spraying high pressure water on a.

In the scale removing apparatus as described above, since the scale removing mechanism 9 is provided at the tip of the lifting cylinder 8, the lifting cylinder 8 is operated to adjust the position of the scale removing mechanism 9. Heat transfer tube support hole 1a
It has an advantage that the scale adhered to can be removed from the lower part to the upper part in the steam generator.

[0006]

However, in the above-described conventional scale removing apparatus, since the raising / lowering cylinder 8 is raised by using the raising / lowering manual winch 11, the raising / lowering cylinder 8 is raised. Requires labor and effort,
There was a problem of poor work efficiency. Further, since the manual feed mechanism 12 for moving the movable table 7 and the manual winch 11 for standing up are provided at the entrance of the inspection manhole 5, position detection for confirming the ascending / descending position of the scale removing mechanism 9 is performed. The winch 13 could not be installed at the entrance of the inspection manhole 5.

The present invention has been made in order to solve the above-mentioned problems, and the vertical movement of the lifting cylinder can be performed without removing time and effort when removing the scale attached to the heat transfer tube supporting holes of the steam generator. It is an object of the present invention to provide a scale removing device that can stand upright and efficiently remove the scale attached to the heat transfer tube supporting holes.

[0008]

In order to solve the above-mentioned problems, the invention of claim 1 moves from an inspection manhole formed in a steam generator main body on a guide rail inserted in the steam generator. A moving table, a lifting cylinder erected on the moving table, a scale removing mechanism provided at the tip of the lifting cylinder, and the lifting cylinder standing upright with respect to the moving table. A scale removing device having a raising mechanism for moving the movable base integrally with the moving base, and a raising cylinder arranged on the movable base along the longitudinal direction of the guide rail. A roller support that is provided at the tip of the upright cylinder and slidably supports the side surface of the lifting cylinder; and a base end of the upright cylinder that is connected to the guide rail. Turning drive mechanism and comprises a by the freshly raised mechanism for turning the drive along the longitudinal direction of the Le, characterized in that is constituted. According to a second aspect of the present invention, the turning drive mechanism portion rotatably supports a base end portion of the upright cylinder on the movable base, a sector gear fixed to the support shaft, and A rack gear slidably provided on a movable base and driving the sector gear; and a pair of rack gear driving cylinders fixedly opposed to each other on the movable base and slidingly driving the rack gear in the longitudinal direction of the guide rail. It is characterized by comprising. The invention of claim 3 is characterized in that an electric feed device for driving the movable table in the longitudinal direction of the guide rail is provided at the entrance of the inspection manhole.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 8 and 9
The same parts as those shown in FIG. FIG. 1 is a diagram showing an outline of a scale removing device according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a main part of the device. As shown in FIG. 1 and FIG. 2, the scale removing device according to one embodiment of the present invention has a high-pressure water W (see FIG. 3) in a heat transfer tube support hole 1a formed in a heat transfer tube support plate 1 of a steam generator. A scale removing mechanism 9 for removing the scale adhering to the heat transfer tube support hole 1a by spraying with, and an elevating cylinder 8 for vertically moving the scale removing mechanism 9,
The scale removing mechanism 9 and the carry-in mechanism 14 for carrying the lifting cylinder 8 into the steam generator are provided.

As shown in FIG. 3, the scale removing mechanism 9 has a tubular body 92 having a large number of high-pressure water jet nozzles 91.
And a pair of supports 93, 94 that rotatably support the tubular body 92 around the axis of the tubular body 92,
The piston rod 8a of the lifting cylinder 8 is rotatably connected to the support 94 that supports the rear end of the tubular body 92 via a horizontal shaft 95.

The carry-in mechanism 14 has a moving table 7 for carrying the scale removing mechanism 9 and the lifting cylinder 8 into the steam generator. The lifting cylinder 8 is provided on the moving table 7. It is rotatably connected to the fixed base via a horizontal shaft. Further, the carry-in mechanism 14 has a guide rail 6 for guiding the moving table 7 into the steam generator, and an electric feeding device 24 for driving the moving table 7 along the guide rail 6. A raising mechanism 15 is provided on the moving table 7. The electric feeding device 24 includes a feeding rack gear 25 connected to the rear end of the moving table 7,
A gear mechanism 26 for sliding the feed rack gear 25 in the longitudinal direction of the guide rail 6 and a drive motor (not shown) for rotationally driving the gear mechanism 26.

As shown in FIGS. 4 and 5, the upright mechanism 15 has a roller support 18 for supporting the lifting cylinder 8, and the roller support 18 for lifting the cylinder 8.
And a cylinder support shaft 20 for rotatably supporting the upright cylinder 17 about a horizontal axis and a cylinder support shaft 20 as a center. It is composed of a turning drive mechanism section 19 for turning the standing cylinder 17 for turning.

The turning drive mechanism section 19 includes a cylinder support shaft 20.
And the sector gear 21 attached to the
And a rack gear 22 for rotating the
The rack gear 22 is slidably provided on the movable base 16 attached to the tip of the moving table 7. Further, the turning drive mechanism section 19 is provided with a pair of rack gear drive cylinders 23A, 23B facing each other with the rack gear 22 interposed therebetween, and these rack gear drive cylinders 23A, 2B are provided.
3B is fixed on a movable base 16 attached to the tip of the moving table 7.

The reason why the turning drive mechanism section 19 is provided with the two rack gear driving cylinders 23A and 23B is that the cylinder diameter cannot be increased due to the dimensional constraints of the apparatus. The other cylinder pulls the rack gear 22 to gain thrust. In addition, 18a in FIGS. 4 and 5 is a roller support 18.
Side plate, 27 is a piping port for supplying fluid to the cylinders 17, 23A and 23B, and 28 and 29 are piping ports 2
Pipes for supplying fluid to the cylinders 17, 23A, 23B via 7 and 30 are moving rollers for moving on the guide rails 6.

When the scale adhering to the heat transfer tube supporting hole 1a is removed using such a scale removing device, first, the television camera 31 (see FIG. 1) installed on the inspection manhole 5 and the scale are removed. After the guide rail 6 is horizontally inserted into the steam generator from the inspection manhole 5 formed in the steam generator body 4 while being monitored by the television camera mounted on the mechanism 9, the electric feed device 24 is operated to move. The table 7 is moved to a position below the flow hole 3. Next, in this state, the stand-up cylinder 17 is operated to adjust the position of the roller support 18, and the rack gear drive cylinders 23A and 23B of the swing drive mechanism unit 19 are adjusted.
Is operated, the upright cylinder 17 is rotated in the counterclockwise direction in FIG. 5 about the cylinder support shaft 20, whereby the up / down cylinder 8 is vertically upright (see FIG. 7). After that, high-pressure water is sprayed from the high-pressure water jet nozzle 91 provided in the tubular body 92 of the scale removing mechanism 9 to the heat transfer tube support hole 1a to remove the scale attached to the heat transfer tube support hole 1a.

As described above, in the embodiment of the present invention, the position of the roller support 18 is raised and raised.
When the rack gear drive cylinders 23A and 23B of the swing drive mechanism unit 19 are operated while adjusting with 7, the stand-up cylinder 17 rotates about the cylinder support shaft 20 in a predetermined direction so that the lift cylinder 8 moves. It stands upright. Therefore, the lifting cylinder 8 can be vertically raised in a short time without using a manual winch,
As a result, the scale attached to the heat transfer tube support hole 1a of the steam generator can be efficiently removed.

Further, in the embodiment of the present invention, since it is not necessary to install a manual winch or the like for raising and lowering the lifting cylinder 8 at the entrance of the inspection manhole 5, it is possible to detect the position of the scale removing mechanism 9. The detection winch 13 can be installed from the beginning at the entrance of the inspection manhole 5.

Further, in the embodiment of the present invention, the electric feed device 24 is provided at the entrance of the inspection manhole 5, so that the movable table 7 can be moved in the longitudinal direction of the guide rail 6 without labor. Thereby, the scale attached to the heat transfer tube support hole 1a of the steam generator can be removed more efficiently.

[0019]

As described above, according to the present invention,
The lifting cylinder can be erected in a short time without removing the scale attached to the heat transfer tube support hole of the steam generator. A scale removing device that can remove scale efficiently can be provided.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a scale removing device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of the scale removing device shown in FIG.

FIG. 3 is a perspective view showing a scale removing mechanism of the scale removing apparatus shown in FIG.

FIG. 4 is a perspective view showing a rising mechanism of the scale removing device shown in FIG.

5 is a vertical sectional view of the uprighting mechanism shown in FIG.

FIG. 6 is a perspective view of the roller support shown in FIG.

FIG. 7 is a diagram for explaining the operation of the scale removing device shown in FIG.

FIG. 8 is a perspective view showing a conventional scale removing device.

FIG. 9 is a view showing heat transfer tube support holes formed in a heat transfer tube support plate of the steam generator.

[Explanation of symbols]

1 Heat Transfer Tube Support Plate 1a Heat Transfer Tube Support Hole 2 Heat Transfer Tube 3 Flow Hole 4 Steam Generator Main Body 5 Inspection Manhole 6 Guide Rail 7 Moving Stand 8 Elevating Cylinder 9 Scale Removing Mechanism 14 Carrying Mechanism 15 Standing Mechanism 16 Moving Base 17 Stand-up cylinder 18 Roller support 19 Revolving drive mechanism 20 Cylinder support shaft 21 Sector gear 22 Rack gears 23A, 23B Rack gear drive cylinder

─────────────────────────────────────────────────── ─── Continuation of front page (73) Patent holder 000180368 Shikoku Electric Power Co., Inc. 2-5 Marunouchi, Takamatsu City, Kagawa Prefecture (73) Patent owner 000164438 Kyushu Electric Power Co., Inc. 2-1, Watanabe-dori, Chuo-ku, Fukuoka-shi, Fukuoka Prefecture No. 82 (73) Patent holder 000230940 Japan Atomic Power Company, Ltd. 1 1 Kido Mitoshiro-cho, Chiyoda-ku, Tokyo (74) 1 agent above 100057874 Attorney Soga Soteru (6 others) (72) Inventor Yoshimasa Tsukamoto 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd.Kobe Shipyard (72) Inventor Ken-ichi Kasai 1-1-1, Wadazaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industry Co., Ltd. Kobe Shipyard (72) Inventor Shigeo Hashimoto 1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd. Kobe Shipyard (72) Akito Shigeru Furuya 7-1-14 Wadamiya-dori, Hyogo-ku, Kobe, Hyogo Prefecture Nishiryo Engineering Co., Ltd. (56) Reference JP-A-9-90084 (JP, A) JP-A-9-26107 (JP, A) JP 2000-55588 (JP, A) JP 2000-130703 (JP, A) JP 2000-46492 (JP, A) JP 9-218294 (JP, A) JP 9-189402 (JP, A) Special table 7-508585 (JP, A) Special table 8-507139 (JP, A) Special table 2000-513442 (JP, A) US patent 6145583 (US, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) G21C 19/02 F22B 37/48 F28G 15/04 G21D 1/00 G21F 9/28

Claims (3)

(57) [Claims] 1. A moving base that moves on a guide rail inserted into the steam generator from an inspection manhole formed in the steam generator main body, and an elevating cylinder that is erected on the moving base. A scale removing device comprising: a scale removing mechanism provided at a tip end portion of the lifting cylinder; and a stand-up mechanism that vertically raises the lifting cylinder with respect to the moving table. A movable base that moves integrally with the movable base, a standing-up cylinder arranged on the movable base along the longitudinal direction of the guide rail, and a lifting cylinder provided at the tip of the standing-up cylinder. A roller support for slidably supporting the side surface of the roller, and a swivel drive mechanism section for swiveling the base end of the upright cylinder along the longitudinal direction of the guide rail. The freshly-raised mechanism Te descaling apparatus characterized by is configured. 2. The turning drive mechanism section includes a support shaft that rotatably supports a base end portion of the upright cylinder on the movable base, a sector gear fixed to the support shaft, and the movable base. A rack gear that is slidably provided above and that drives the sector gear, and a pair of rack gear driving cylinders that are fixed on the movable base so as to face each other and that slide-drives the rack gear in the longitudinal direction of the guide rail. The scale removing device according to claim 1, wherein the scale removing device is configured as follows. 3. An electric feed device for driving the movable table to run in the longitudinal direction of the guide rail is provided at the entrance of the inspection manhole.
The scale removing device described.