JPS6026974B2 - Automatic Penetration Detection Development Tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic penetrant flaw detection and development tool that mechanizes the development work of deep penetrant flaws during the repair of steam generator piping in a nuclear power plant.

Steam generators in nuclear power plants are sometimes repaired by plugging the pongee pipes, but after welding, penetration testing (PT) is carried out to confirm the integrity of the welding.

However, the work area is contaminated with radioactivity, making it impossible for humans to work for long periods of time.

Therefore, there is a need to remotely automate the work and reduce radiation exposure of workers. The present invention realizes these problems, and therefore takes the following countermeasures to solve the problem.
A tank pressurized with air pressure was equipped with a valve that could be opened and closed by remote control, and a spray nozzle was used to atomize the developer. (21) The nozzle can be applied in a circular manner to uniformly apply the liquid to the circular weld area.

[3' The nozzle was covered with an outer cylinder, and a seal was provided at the tip of the outer cylinder to prevent liquid from scattering.

[A propeller for clear water was installed in the 4' tank to prevent settling of the liquid.

[5] By joining this tool to a walking guide device using a one-touch joining mechanism using air cylinders and moving the guide device, cleaning at the required location was completely automated.

That is, in the present invention, the operation is regulated by a ball valve that opens and closes with an air piston at the top of a conduit inserted into the tank, which has a pressurized developer tank and a rotating propeller installed at the bottom, and is placed at an appropriate distance from the deeply damaged area. A gear is provided on a rotatable cylinder, and a spray nozzle is eccentrically assembled into a valve body, a seal rod is attached to the center of the upper part of the valve body, and a seal rod is attached to a holder that covers between the part to be inspected and the spray nozzle. A hood with a sealing part is attached to the upper end that contacts the deeply damaged part, and the tool is held by two guide shafts, a screw rotated by a motor is connected, and the tool is attached to the machine for fixing the screw. The automatic penetrating deep scratch developing tool is equipped with a seat and is attached by the pneumatic actuation of a locking pin installed on a guide moving device.

Embodiments of the present invention will be described in detail below with reference to the drawings.

As an example, an example will be described in which the tool of the present invention is applied as a cleaning device for penetrant inspection of a welded part of a pongee pipe plug of a steam generator of a nuclear power plant.

FIG. 1 shows a state in which the present tool is applied to a steam generator having a main body container 1, a tube plate 2, and a capillary tube (hereinafter simply referred to as a tube) 3.

The tool of the present invention operates while attached to the guide device 4 (section A in FIG. 1).

The guide device uses the tube 3 and can walk under the tube plate 2 in a hanging state. Therefore, this tool can be guided to a required position by remote control and the cleaning work can be performed automatically. The guide device 4 can be inserted through the manhole 5, and this tool can also be inserted through the manhole 5, and can be operated remotely by connecting a cable to a control board.

Figures 2, 3, 4, and 5 show the cleaning tool (first
It is a detailed view of part A).

In the figure, reference numeral 6 indicates a plug, which has a welded portion 7 around its periphery.

A spray nozzle 8 is installed above the developer flow path 9.

The ball valve 10' is normally sealed by the reaction force of the spring 11 and the hydraulic pressure applied to the tank 12.

13 is a piston, which has an opening/closing rod 14 at its tip;
Normally, the structure is such that the reaction force of the spring 15 prevents contact with the ball valve 10.

A conduit 17 connects the tank 12 and the Paul valve 10.

18 is a rotating cylinder that connects the pressurizing row 9 and the tank 12.

It is a developer stored in a tank 12, and is constantly illuminated by a propeller 22 rotated by a Hinazusa motor.

23 and 24 are transmission gears that transmit the rotational force of the nozzle rotation motor 25 to the rotating cylinder 18.

26 is a magnetic sensor that detects the rotation speed by pulses generated by a magnet 27 installed on the gear 23.

A holder 28 holds the rotary cylinder 18 and the valve body 29 via bearings, and is connected to the vertical guide 30.

Additionally, the nuts 32 for the upper and lower screws 31 are replaced. The upper and lower screws 31 can be driven by a vertical motor 33, and the lower and upper end positions can be set by limit switches 34 and 35 (FIG. 3).

36 is a hood, and a rubber seal 37 having elasticity is disposed circumferentially at the tip of the hood.

In this case, there is also a method of providing a suction nozzle in the hood 36 to collect the atomized developer floating in the hood after the completion of the process.

38 is a seal rod, and an elastic ring 39 and a seal washer 40 are attached to the tip.

Further, the other end of the seal rod 38 is attached to a valve body 29 and rotates at the same time as the valve body 29 which is screwed to the rotary joint 18.
Reference numeral 41 denotes a flow path for air for operating the piston 13, which is in communication with the uneven supply port 42.

A holding frame 43 is connected to a mounting seat 44 and to an attachment 45 provided on the guide device 4.

The mounting seat 44 has a lock hole 46, and the air piston 47
It is fixed by inserting a lock pin 48 provided in the.
49 is a sealing ring, which is installed at nine locations.

5. This is a supply ring groove for the river water and is sealed with a seal plug screw 51. In FIG. 2, a indicates the direction of air, and b indicates the water surface. Next, the operation of the present invention will be explained.

The tool guided to a predetermined position by the guide device 4 is
It is raised by the upper and lower screws 31 (keep it at the lower limit when moving).

When the upper limit position is reached, the limit switch 35 is activated.
Stop. At this time, the tip of the seal rod 38 is connected to the plug 6.
The seal washer 40 is inserted into a small hole provided in the plug, and the seal washer 40 comes into close contact with the plug surface. Therefore, the sprayed developer does not enter the small pores, and post-processing (removal of the developer) becomes easy. Further, the developer 20 is transferred to the hood 3 due to the action of the rubber seal 37 that is in close contact with the outer surface of the hood 36 and the weld saddle portion 7 of the plug 6.
Developing work is carried out without scattering to the outside of 6. Air pressure applied from the V supply hole 42 pushes the piston 13 through the flow path 41.

As a result, the opening/closing rod 14 pushes the ball valve 10, and the developer 20 pressurized by the air pressure from the pressurizing port 19 flows through the flow path 9, reaches the spray nozzle 8, and is sprayed in a mist form. Since the spray nozzle 8 and the welding part 7 are separated by an appropriate distance, the atomized developer 20' becomes uniform and adheres to the surface of the plug 6 at the center of the welding part 7.

Moreover, since the spray nozzle 8 can be rotated by the nozzle rotation motor 25, by spraying while rotating the spray nozzle 8, the liquid is uniformly applied to the circular weld line. In addition, the developer 20 is always kept in motion by the propeller 22 rotated by the fly motor 21, thereby preventing precipitation of the developer.

It can be easily attached to and detached from the guide device 4 via an attachment 45 by the action of a lock pin 48.

That is, by pulling out the lock pin 48 from the lock hole 46, the mounting seat 44 can be easily separated from the attachment 45. If the work is carried out using a jig (not shown), the device of the present tool can be carried out without being in close proximity to the guide device 4. The tool of the present invention exhibits the following effects through the above configuration and operation.

'1' The development work for penetrating deep flaws, which conventionally relied on manual labor, can be mechanized, making it possible to detect flaws safely, quickly and reliably.

[2] Set the rotating nozzle at an appropriate distance from the welding area,
By roughly matching the valve with a valve that opens and closes remotely, it is now possible to apply a uniform developer solution completely remotely. The amount of rotation is detected by a detector. The Tomohira propeller prevents the developer from settling.

{4) Since the spray section is isolated from the outside, scattering of the developer can be prevented.

Furthermore, if the mist liquid inside the hood is collected by suction after the work is completed, almost no liquid will leak outside. [51] It is extremely easy to attach to the guide device, shortening the attachment time and reducing the amount of radiation exposure. Furthermore, if the device is installed using a jig, there is no need to approach the operating parts where the radiation dose is high, and the amount of radiation exposure is further reduced. '61 By moving the guide device mentioned above, it became possible to develop a predetermined amount of fakes remotely, reducing the exposure to radiation to a fraction to a few tenths of that of conventional manual processing. Become.

[Brief explanation of drawings]

Fig. 1 is a partially fractured cross-sectional view of an example in which the automatic penetrating deep wound cleaning device according to the present invention is used as a cleaning device for deep penetrating cracks in a welded part of a pongee pipe plug of a steam generator, and Fig. 2 is a partially fractured view of A of Fig. 1. 3 is a plan view taken from A in FIG. 2, FIG. 4 is a sectional view taken along line B-B in FIG. 3, and FIG. It is a cross-sectional view taken along line CC in the figure. 1...Main container, 2...Tube plate, 3...
... Thin tube, 4... Guide device, 5...
... Manhole, 6... Plug, 7... Welded part, 8...
...Spray nozzle, 9...Developer flow separation, 10.
... Ball valve, 12 ... Tank, 13 ... Piston, 14 ... Opening/closing rod, 17 ... Conduit,
18... Rotating node, 19... Pressure port, 2
0...Developer, 21...Takaazusa motor,
22... Propeller, 23, 24... Transmission gear, 25... Nozzle rotation motor, 26... Magnetic sensor, 29... Valve body, 30... Upper and lower guide, 33...Upper and lower mode guide, 34, 35...
...Limit switch, 36...Hood, 37...Rubber seal, 38. ．．・．． ．．・Seal rod, 41...
...Flow path, 42...V supply port, 46...Lock hole, 47...Air piston, 48...Lock pin. Purple↑Figure 3Figure 2Figure 4Figure 5

Claims (1)

[Claims] 1. Operation is regulated by a ball valve that opens and closes with an air piston at the top of a conduit inserted into the tank with a pressurized developer tank and a rotating propeller at the bottom, and there is no appropriate distance from the part to be inspected. A gear is provided on a rotatable cylinder, a spray nozzle is assembled eccentrically, a valve body is attached, and a seal rod is attached to the center of the upper part of the valve body, and the flaw detection is continued to a holder that covers the area between the flaw detection target area and the spray nozzle. A hood with a sealing member is attached to the upper end that contacts the target part, the tool is held by two guide shafts, a screw rotated by a motor is connected, and a mounting seat is attached to the machine body for fixing the screw. An automatic penetrant flaw detection developing tool that is equipped with a locking pin installed on a guiding moving device and installed by pneumatic actuation of a locking pin.