JP3188161B2 - Vertical steam generator cleaning device and telescopic arm therefor - 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 remotely cleaning the inside of a steam generator having a complicated internal structure, such as a tube-shell heat exchanger.

[0002]

2. Description of the Related Art For example, a vertical steam generator used in a pressurized water reactor is a kind of tube-shell type heat exchanger having therein a heat transfer tube bundle surrounded by a wrapper tube, but generates steam. Sludge easily accumulates in the body-side space where the water flows. The structure of the lower portion of such a steam generator will be described with reference to FIGS. 6 and 7. The tube sheet 3 is integrally joined to the lower portion of the body 1, and a number of heat transfer tubes forming a heat transfer tube bundle 5 are formed on the tube sheet 3. The ends of the heat tubes 7 are connected. The heat transfer tube bundle 5 is surrounded by a wrapper tube 9,
An intermediate portion of each of the heat transfer tubes 7 is horizontally supported by tube support plates 11 arranged at intervals in the vertical direction. In a typical example, the heat transfer tube 7 is an inverted U-shaped tube, and the heat transfer tube bundle 5 has a dead space corresponding to a minimum bending radius in the center portion.
Are formed.

Conventionally, it is considered that sludge is accumulated most on the tube sheet 3. A telescopic multi-stage telescopic rod is inserted from the inspection hole 15 of the body 1 and high-pressure washing water is supplied from a nozzle at the tip thereof. Sludge that has erupted and accumulated around the base of the heat transfer tube 7 is to be washed away.

[0004]

However, if the above steam generator is used for a long period of time, the lowermost tube sheet 3
Not only on the pipe support plate 11 but also on the upper tube support plate 11, a considerable amount of sludge has accumulated, and it has become necessary to wash and remove the sludge. However, in the method of inserting the multistage telescopic rod through the inspection hole near the tube sheet as described above, sludge removal on the tube support plate cannot be physically realized. Further, the outer shell of the steam generator is a kind of pressure-resistant container, and it is not realistic to provide a number of inspection holes corresponding to each upper tube support plate due to the presence of a wrapper tube surrounding the heat transfer tube bundle. Was. Therefore, the cleaning device inside the vertical steam generator that can be inserted from the inspection hole near the tube plate, cleans the sludge on the upper tube support plate, has good operability, and can easily be taken out in the event of a failure. Was required. The present invention has been made to respond to such conventional requests and needs.

[0005]

In order to solve the above-mentioned problems, a vertical steam generator cleaning apparatus according to the present invention has a guide rail which can be inserted from an inspection hole of a steam generator, and can be moved on the guide rail. A lifting and lowering device that can be raised and lowered, a telescopic arm that can be bent and pivoted at the upper end of the lifting and lowering device, a feed device that is provided at the front end of the telescopic arm, and that is movable along the lifting and lowering device and the telescopic arm. Further, it is composed of a flexible cleaning liquid supply jetting zone which is sent by the feeding device. The telescopic arm is preferably a fixed part fixed to the upper end of the elevating device, a turning part pivotally connected to the fixed part via a pin, a pivoting cylinder integrally fixed to the fixed part, and It is constituted by a pivoting wire interposed between the pivoting cylinder and the pivoting portion, and the pivoting portion includes a telescopic cylinder which is separated from and close to a front end supporting the feeder. More preferably, a lifting wire mechanism is provided along the lifting device to lift the flexible cleaning liquid supply and ejection zone from the upper end of the lifting device to the rear end of the telescopic arm, thereby reducing the load on the feeding device. In a preferred embodiment, the pivoting wire includes a connecting portion made of a thermoplastic resin and a heater wire for cutting, and can be cut in the case of an emergency such as a failure to improve emergency escape.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a position in which a cleaning device 20 according to the present invention enters a steam generator and is ready for a cleaning operation. In the figure, a guide rail 21 passing through the inspection hole 15 indicated by a two-dot chain line is supported by a suitable gripping device that forms the base of the entire cleaning device 20 but stays outside the steam generator. The lift device 3 is movably mounted on the guide rail 21.
0 is supported and consists of a running part 31 and a raising and lowering part 33 pivotally connected thereto. The elevating elastic part 33 is
When passing through the inspection hole 15, it falls on the guide rail 21, is pivoted inside the steam generator as shown, and passes through the notch 13 of the tube support plate. The elevating and retracting portion 33 can move up and down at the upper end in a normal multi-stage expanding and contracting structure. A holding mechanism 35 is provided on the tip side of the elevating and contracting portion 33. The holding mechanism 35 is of a heat transfer tube clamp type, and is for stabilizing a turning operation and a feeding operation of the flexible insertion band described later. Further, a pivotable telescopic arm 40 is attached to the upper end of the elevating telescopic part 33, and a feeding device that feeds the flexible insertion zone 23, which is a flexible cleaning liquid feeding / spouting zone, between the heat transfer tubes 7 to the front end of the telescopic arm. 25 are provided. Flexible insertion band 2
Numeral 3 is a thin strip formed of a flexible hose for sending high-pressure washing water, a linear member for remotely viewing the insertion tip, and the like, and has a washing water outlet at the tip.

The detailed structure of the pivotable telescopic arm 40 is shown in FIGS. In these figures, the fixed portion 41 and the turning portion 43 are connected by a support pin 45 so as to be capable of bending and pivoting. In order to minimize the torque required for pivoting (turning) of the turning portion 43, the support pin 45 is Telescopic arm 40
It is located in the central part. An air cylinder 47 is provided integrally or fixedly on the fixing portion 41 having a U-shaped cross section to pivot the turning portion 43. The air cylinder 47 may be a hydraulic cylinder, but is attached as described above and
1 has increased rigidity. As shown in FIG. 4 (a), which is an operation explanatory diagram, the piston rod 49 of the air cylinder 47
Are not directly connected to the turning portion 43 but are connected via a wire 51. By connecting with the wire 51 in this way, when the piston rod 49 is pulled in,
As shown in FIG. 6B and FIG. 6C, the turning portion 43 pivots around the support pin 45 and is folded 90 degrees. On the other hand, when the air cylinder 47 is operated so as to push out the piston rod 49, the head of the piston rod 49 comes into contact with the turning part 43, and the turning part 43 pivots in the counterclockwise direction (in the figure) to rotate as shown in FIG. Return to the state of (a). By using the wire 51 in this manner, a flexible connection is achieved.

Further, a two-stage hydraulic cylinder 53 and a guide mechanism 55 parallel to the two-stage hydraulic cylinder 53 are provided in the swivel portion 43 so as to extend in the longitudinal direction.
5 is vertically offset as shown in FIG.
The rigidity of the turning part 43 is increased. The amount of expansion and contraction of the hydraulic cylinder 53 can be remotely measured by measuring the amount of expansion and contraction by the ultrasonic sensor 57, and the amount of expansion and contraction is controlled by providing a flow control circuit for the supply water outside the steam generator. ing.

At the rear end opposite to the front end to which the feeder 25 is attached, a pulley 59 of a lifting wire mechanism is provided, around which a lifting wire 61 is wound, and the wire 61 is raised and lowered. It extends to the elevating telescopic part 33 of the device 30. The wire 61 lifts the flexible insertion band 23 fed from the feeding device 25 and the tubes attached thereto, thereby reducing the load on the feeding device 25 and facilitating miniaturization. Further, this wire 61 is guided outside the steam generator along the guide rail 21 and the like,
The air cylinder 47 functions as a recovery unit of the swivel unit 43 when the air cylinder 47 breaks down. Reference numeral 63 denotes a mechanism for recovering the flexible insertion band 23, which transmits the output to the flexible insertion band 23 and recovers the same. An air cylinder 47 that pivots (turns in the range of about 90 degrees) of the turning unit 43 is fixed, and even if the wire 61 is used, the turning of the turning unit 43 becomes difficult.
In a case where it becomes difficult to collect the wire, a connecting portion made of a thermoplastic resin is provided on the wire 51 so that the connecting portion can be melt-cut remotely. If the melt cutting is performed, the swivel part 43 becomes free with respect to the fixed part 41, so that the recoverability, that is, the emergency escape property is improved. On the other hand, by providing the visual camera at the rear end of the turning section 43, the situation before pivoting, the operation situation of the holding mechanism 35, and the situation after pivoting can be remotely observed.

In order to bring the cleaning device 20 having the above structure into the steam generator through the inspection hole 15, the telescopic arm 40 is shortened and the fixed portion 41 and the turning portion 43 are arranged as shown in FIG. Is made linear, and the elevating / contracting portion 33 of the lifting / lowering device 30 is turned down to the state shown in FIG. Then, the elevating and retracting portion 33 is pivoted to a vertical position, and after the telescopic arm 40 is passed through the notch 13, the turning portion 43 is pivoted to a position as shown in FIG. Is moved to a target position, and the flexible insertion band 23 is inserted between the heat transfer tubes 7 to perform cleaning. In order to take the cleaning device 20 out of the steam generator, the above-described procedure may be retroactively performed.

[0011]

As described above, since the cleaning device according to the present invention has the guide rail, the elevating device that can be raised and lowered, and the telescopic arm that can be bent and pivoted, it can be inserted from the inspection hole near the tube plate of the steam generator. However, the sludge can be washed and removed by accessing the upper tube support plate and inserting the flexible cleaning liquid supply jetting zone between the heat transfer tubes by the feeding device. Further, since the turning part and the fixed part which constitute the telescopic arm are connected by a combination with the pivoting cylinder wire, not only the rigidity of both can be increased but also the escape property in an emergency can be improved.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a cleaning device 20 according to an embodiment of the present invention.

FIG. 2 is a telescopic arm 40 which is a main part of the embodiment of the present invention.
FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is an operation explanatory view in the embodiment.

FIG. 5 is an operation explanatory view of the telescopic arm 40.

FIG. 6 is a partial sectional elevation view of a steam generator to be cleaned by the cleaning device according to the invention.

FIG. 7 is a partial cross-sectional plan view of a steam generator to be cleaned by the cleaning device according to the present invention.

[Explanation of symbols]

 Reference Signs List 20 cleaning device 21 guide rail 23 flexible insertion band 25 feeding device 30 elevating device 31 running unit 33 elevating and retracting unit 40 telescopic arm 41 fixing unit 43 turning unit 45 support pin 47 air cylinder 51 wire 53 hydraulic cylinder 57 ultrasonic sensor 59 pulley 61 wire

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hidekazu Ina 1-1-1, Wadazakicho, Hyogo-ku, Hyogo-ku, Kobe City, Hyogo Prefecture Inside Kobe Shipyard, Mitsubishi Heavy Industries, Ltd. (72) Inventor Seiichi Morimoto Hyogo, Kobe City, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (1-1) 1-1, Wadazaki-cho, Tokyo (72) Inventor Mitsuo Kuwahara 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (58 ) Surveyed field (Int.Cl. ⁷ , DB name) B08B 9/093 B08B 3/02

Claims (8)

(57) [Claims] A guide rail which can be inserted from an inspection hole of a steam generator, an elevating device which can move on the guide rail and can be raised and lowered, a telescopic arm which can be bent and pivoted and is provided on an upper portion of the elevating device. A vertical device comprising: a feed device provided at a front end of the telescopic arm; and a flexible cleaning liquid feeding / spouting zone movable along the elevating device and the telescopic arm and fed by the feed device. Cleaning device in a steam generator. 2. A lifting wire mechanism is provided along the elevating device for lifting the flexible cleaning liquid supply jetting zone from an upper end of the elevating device to a rear end of the telescopic arm. Cleaning device in vertical steam generator. 3. A fixed portion fixed to an upper end of the lifting device, a turning portion pivotally connected to the fixed portion via a pin, a pivoting cylinder integrally fixed to the fixed portion, and The telescopic arm is constituted by a pivoting wire interposed between a cylinder and the turning part, and the turning part is provided with a telescopic cylinder that separates and approaches a front end supporting the feeder. The cleaning device in a vertical steam generator according to claim 1. 4. The vertical steam generator cleaning apparatus according to claim 3, wherein the pivot wire includes a thermoplastic resin connecting portion and a cutting heater wire. 5. An ultrasonic sensor for measuring the amount of expansion and contraction of the telescopic cylinder is provided at the turning portion of the telescopic arm, and the flow control circuit for the telescopic cylinder is provided separately from the telescopic arm. Item 4. A cleaning device in a vertical steam generator according to Item 3. 6. A swivel part having an extendable cylinder, a fixed part pivotally connected to a longitudinal center of the swivel part via a pin, a pivoting cylinder integrally fixed to the fixed part, and A telescopic arm for a vertical steam generator internal cleaning device, comprising a pivoting wire interposed between the cylinder and the swiveling part. 7. The telescopic arm for a vertical steam generator cleaning device according to claim 6, wherein the pivot wire includes a thermoplastic resin connecting portion and a cutting heater wire. 8. The telescopic arm for a vertical steam generator cleaning device according to claim 6, wherein an ultrasonic sensor for measuring the amount of expansion and contraction of the telescopic cylinder is provided in the turning part.