JPS6367563A - Automatic inspecting method for tank internal surface coating - Google Patents

Abstract

PURPOSE:To inspect a coating state in a safe area at any time without stopping a tank by employing a method which moves an ultrasonic probe on the external surface of the tank, and analyzes an echo at each position and judges the coating state. CONSTITUTION:A diagnostic recorder 6 is set at distance from the tank 1 and a reference point is marked on the external surface of the tank side wall 4. A tank-side measuring instrument 5 is set on the tank side wall 4. A console panel 16 is operated to start the diagnostic recorder 6 and the tank-side measuring instrument 5 is scanned longitudinally (in height direction) and laterally (in circumferential direction) repeatedly to scan over the entire surface of the tank side wall 4. The result is displayed as an echo on a scope and recorded on a printer 15. When the tank side wall 4 is normal, two echoes appear on the scope and when the coating is peeled off to float, three echoes appear.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for inspecting the coating condition of the inner surface of a tank using ultrasonic waves.

[Conventional technology]

Conventionally, the condition of the coating on the inside of a tank has been inspected by opening the tank. For example, in the case of a storage tank containing a solution containing radioactive materials in a nuclear power plant, after it has been operated for about five years without any internal inspection, an overhaul inspection is performed and the interior surface coating is partially repaired depending on the condition of the coating. In addition, if necessary, we conduct an open inspection again during regular plant inspections and repaint the entire surface.

[Problem that the invention seeks to solve]

However, with the conventional inspection method using open inspection, inspection cannot be performed unless the tank function is stopped, and losses during tank function stoppage are extremely large.
:q. Open inspection work was troublesome and could not be done frequently, and the status of internal replacement could not be checked for a long time.

Furthermore, it is not possible to know in advance the state of the paint on the inside of the tank.

The preparation for repair painting was not done properly.

In addition, if the contents are harmful to the human body such as poisonous substances or radioactive substances, open inspection work is difficult, and in the case of storage tanks for radioactive substances, it is necessary to temporarily set up a temporary controlled area for open inspection. Liquid transfer, internal decontamination, etc. were required, and the work was performed within a contamination control area, resulting in an extremely low work efficiency, and it was difficult to reduce the radiation exposure of workers.

The present invention solves one or more problems and provides an automatic tank inner coating inspection method that can extremely easily diagnose the coating condition of the tank inner surface even when the tank is in operation, without having to conduct an open inspection. The purpose is to

[Means for solving problems]

In order to achieve the above object, the present invention moves an ultrasonic probe on the outer surface of the tank and analyzes echoes at each position to determine the coating condition, thereby eliminating the need for open inspection work. This is how it was done.

That is, the tank inner surface coating automatic inspection method of the present invention is #
A sonic probe is moved on the outer surface of the tank, and the position of the ultrasonic probe and the ultrasonic signal are output to a diagnostic recorder installed separately from the ultrasonic probe. The system is characterized by determining the coating state of each part of the system.

The ultrasonic probe used in the automatic measurement method for tank inner surface coating of the present invention may be one that can detect a swollen or swollen state in which the inner surface coating has peeled off by applying ultrasonic waves from the outer surface of the tank side wall. The frequency, direction of incidence, etc. of the ultrasonic waves can be changed as appropriate. To move the ultrasonic probe on the outer surface of the tank, it is sufficient to move at least the entire outer surface of the side wall of the tank.

The method of movement may be alternately vertical and horizontal movement, spiral movement, or other methods.

The diagnostic recorder is capable of determining the paint condition of each part by inputting fc flaw signals from an ultrasonic probe, and it would be good if it had a means such as a printer or a motor to identify parts where the paint condition is not normal.

[Effect]

In the tank inner surface coating automatic inspection method of the present invention, the state of the inner surface coating is detected by moving the ultrasonic probe on the outer surface of the tank, so the tank can be operated only on the outside of the tank without having to stop the tank. Additionally, the state of the internal coating is determined using a diagnostic recorder installed separately from the ultrasound probe, so work can always be done in a safe area.

〔Example〕

An example of an automatic tank inner surface coating inspection method according to the present invention will be described with reference to FIGS. 1 to 3.

Figure 1 is a diagram showing the implementation state of the automatic inspection method for tank inner surface coating, Figure 2 is a block diagram showing the configuration of the equipment used for the same, and Figure 3 (&) is a tank showing normal tank inner coating. Figure 3 (b) is a partial cross-sectional view of the side wall showing the scope at the same location as above; Figure 4 (a) is a partial cross-sectional view of the tank side wall showing the next state after the inner surface coating of the tank has peeled off. Cb) is a diagram showing a scope at the same site.

In FIG. 1, reference numeral 1 denotes a tank, and a shielding wall 2 and a rain cover 3 are provided around the tank 1. Further, on the outer surface of the tank side wall 4, a measuring device 5 on the next tank side is installed, which is carried in through the manhole of the rain cover 3. This tank side measuring device 5 moves on the outer surface of the tank (1111 wall 4) and uses ultrasonic waves to detect peeling and swelling of the inner surface coating.
This is what is output to. The diagnostic recorder 6 analyzes and processes the signal emitted by the tank-side measuring device 5, and displays and records the analysis results, and is installed at a location exposed to heat from the tank 1.

As shown in FIG. 2, the tank-side measuring device 5 includes an ultrasonic probe 7, a drive unit 8 that moves the ultrasonic probe 7 in the generatrix and circumferential directions on the outer surface of the tank side wall 4, and An interface 9 that converts the signal input from the drive unit 8 informing about t= and the signal input from the ultrasonic probe 7 into transmission, and a communication device 1 that transmits this signal to the diagnostic recorder 6.
It consists of 0.

Further, the diagnostic recorder 6 also has one communication device 10 as shown in FIG.
a communication device 11 that receives a signal emitted by a computer; an interface 12 that converts the received signal into a signal suitable for computer processing; a computer 13 that analyzes and processes input signals from this interface 12; and an analysis result of this computer 13. It consists of a monitor 14 that displays the results on the screen, a printer 15 that records the analysis results, and an operation panel 16 that performs other operations such as starting and stopping.

In the apparatus described above, in order to inspect the inner surface coating of the tank, first, the diagnostic recorder 6 is set at a location away from the tank 1, and then a reference point is marked on the outer surface of the tank side wall 4. Then, after setting the tank side measuring device 5 on the tank side wall 4, a test is performed. Operation panel 16 after the test
is operated to start the diagnostic recorder 6, and the tank side measuring device 5 is caused to repeat vertical scanning (outgoing line direction scanning and horizontal direction scanning (circumferential direction scanning)) to scan the entire surface of the tank side wall 4. At this time, if the tank inner surface coating device 7 is properly lined with the tank side wall 4 as shown in FIG. 3(a), two echoes will appear on the scope as shown in FIG. 3(b). appears.On the other hand.

As shown in Fig. 4(,), if the tank inner surface falling device 7 is separated from the tank side wall 4 and is floating, as shown in Fig. 4(,),
As shown in b), three echoes are displayed on the scope. In this way, the state of the tank inner surface coating device 7 at each location on the tank side wall 4 is monitored, and the results are recorded by the printer 15.

After the entire surface of the tank side wall 4 has been scanned, the tank side measuring device 5 is removed from the tank side wall 4 and a confirmation test is performed, and the diagnostic recorder 6 is also removed to complete the inspection work.

〔Effect of the invention〕

In the present invention, an ultrasonic probe is scanned on the outer surface of the tank, and a separately provided diagnostic recorder is used to judge the coating condition based on the position of the ultrasonic probe and the ultrasonic signal at this time. The internal coating condition can be diagnosed even during operation, without reducing the operating efficiency of the equipment. Moreover, there is no need for preparatory work or post-processing work after coating condition diagnosis, and when repairing the inner surface, sufficient preparation can be made in accordance with the situation before opening the tank. Furthermore, in the case of radioactive material tanks, contamination V
Since there is no work to be done in radiation control areas and only a small amount of work is to be done in radiation control areas, work can be carried out extremely safely.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the implementation state of the automatic inspection method for tank inner surface coating according to the present invention, Fig. 2 is a block diagram showing the configuration of the device used for the same, and Fig. 3 (a) and (b) are diagrams showing the implementation status of the tank inner surface coating automatic inspection method according to the present invention. Figures 4(a) and 4(b) are partial cross-sectional views of the tank side wall showing a normal state and a view showing its scope, and Figures 4(a) and 4(b) are partial cross-sectional views of the tank side wall showing a state where the inner surface coating of the tank has peeled off and views showing its scope. be. 1...tank, 2...shielding wall, 4...tank ff
1L wall, 5...Tank side measuring device, 6...Diagnostic recorder, 7...Ultrasonic probe, 17...Tank inner surface coating. Patent applicant: Nippon Doppan Co., Ltd. Representative Patent Attorney 1) Masahiro Naka and one other person Figure 1 Figure 3 Figure 4 (a) (b)

Claims (1)

[Claims] The ultrasonic probe is moved on the outer surface of the tank, the position of the ultrasonic probe and the ultrasonic signal are output to a diagnostic recorder installed separately from the ultrasonic probe, and the diagnostic recorder records the inner surface of the tank. An automatic tank inner surface coating inspection method characterized by determining the coating condition in each part of the tank.