JP3452773B2 - Pipe thinning state evaluation method and its evaluation device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating a thinned state of a pipe or the like and an evaluation apparatus therefor.

[0002]

2. Description of the Related Art Pipes or containers (hereinafter referred to as pipes)
In the case of evaluating the thinned state of No. 3, it was common to directly contact the terminal portion with the pipe by an ultrasonic flaw detection test or the like. However, the outside of the pipe is often covered with a heat insulating material or the like, and it was necessary to remove the cover before the evaluation in the ultrasonic flaw detection test.

Further, even in the case of non-destructive inspection using X-rays, it is difficult to evaluate quantitatively, and it has not been possible to decide the maintenance time by judging the state of thinning.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the problem of having to remove the cover in the case of the conventional ultrasonic flaw detection test, and enables diagnosis with the cover attached. It is what

Further, it is intended to make it possible to perform quantitative evaluation even in the case of evaluation by X-ray and to accurately manage the maintenance time of the pipe.

[0006]

According to the present invention, an image analysis is performed using radiation transmission information of a gray value for each unit pixel of the pipe or the like obtained by irradiating the pipe or the like with radiation such as X-rays from the outside. It is characterized by executing and evaluating the thinning state of the pipe or the like.

In this case, the image analysis is characterized by superimposing reference information formed from previously recorded design information of the piping and the like and the radiation transmission information.

Further, in the image analysis for evaluating the amount of thinning as the thinning state, (1) the overlay transmission information obtained by the overlay is decomposed for each unit pixel, and The depth dimension of the thinning for each unit pixel is converted from the gray value displayed by the overlay transmission information on the image, and (2) the depth dimension is multiplied by the area of the unit pixel to obtain the The minute volume ΔC in the thinned state corresponding to each unit pixel is obtained, and (3) the minute volume ΔC is integrated with respect to all the area ranges evaluated to be the thinned state of the thinned wall from the overlay transmission information. Then, the volume C of the thinning is obtained.

The present invention further relates to an apparatus for evaluating a thinning state of a pipe or the like, which is provided with a radiation generator and a radiation detector which are arranged to face each other with a pipe or the like of a processing system for conveying a substance or a fluid being sandwiched therebetween. Radiation is radiated from the radiation generator to the pipe and the like, and the radiation transmission information of the gray value for each unit pixel about the inside of the pipe or the like obtained by the radiation detector from the transmitted radiation is input in advance, and
Standard information formed from the recorded design information of the piping, etc.
There is provided a thinning condition evaluating device for a pipe or the like, comprising: an analysis device for evaluating a thinning condition inside the pipe or the like by performing image analysis by superimposing a report and the radiation transmission information .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a pipe thinning state evaluation apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing the details of the pipe thinning state evaluation device of FIG. The example of composition when the evaluation device of this example is actually applied to piping inspection is shown.

Referring to FIGS. 1 and 2, the evaluation apparatus of the present embodiment comprises an X-ray generator 1 as a radiation generator, an X-ray detector 3 as a radiation detector, an information converter 5, and an analyzer. 6, a recording device 7, a display device 8, and a supporting device 9 (9
a, 9b).

As shown in FIG. 2, the analysis device 6 may include a recording device 7 and a display device 8. Further, the analysis device 6 may be configured to include the information converter 5 as well. Furthermore, the evaluation device may not include the support device 9. Therefore, the evaluation device has a configuration including at least the X-ray generator 1, the X-ray detector 3, and the analysis device 6. 100 indicates a shield.

The pipe thinning condition evaluation device moves the X-ray generator 1 and the X-ray detector 3 simultaneously or separately by the supporting devices 9a and 9b in order to investigate the pipe thinning condition. The X-ray generator 1 is configured such that any component equipment to be investigated for the heat insulating material 10 for purifying a final product or an intermediate product from a certain substance is sandwiched with the pipe 2 covered with the heat insulating material 10.
(That is, the radiation generator) and the X-ray detector 3 (that is, the radiation detector) are arranged to face each other in the irradiation range of the X-rays (that is, the radiation), and X is applied to the pipe 2 as the investigation target. Line 1
a, irradiate X-ray transmission information (that is, radiation transmission information) of the gray value for each unit pixel related to the pipe from the X-ray detector 3, and analyze the X-ray transmission information by a predetermined image processing procedure, Analyzing device 6 for evaluating the thinned state of the thinned portion 4 of the pipe 2
Equipped with.

The operation of the evaluation device having the above structure is as follows. The X-ray generator 1 and the X-ray detector 3 are arranged to face each other with the pipe 2 sandwiched therebetween, and the pipe 2 is irradiated with X-rays 1a as radiation from the X-ray generator 1, and the transmitted radiation is used. Piping 2
The X-ray detector 3 obtains X-ray transmission information regarding

Next, the information converter 5 converts the obtained X-ray transmission information into conversion information that can be analyzed by the analysis device 6 described later. Then, the analysis device 6 quantitatively obtains the thinning state of the target pipe 2 by analyzing the conversion information as the X-ray transmission information. Also,
If necessary, the analysis information indicating the evaluated thinning state is recorded in the recording device 7, and further displayed on the display device 8.

Further details will be described.

The X-ray generator 1 and the X-ray detector 3 are arranged so as to face each other in a range where X-rays are effectively irradiated, and further,
Support by means of a supporting device 9 (9a, 9b) as means for moving the X-ray generator 1 and the X-ray detector 3 to arbitrary positions so that X-ray transmission information regarding the thinning of the pipe 2 can be obtained as desired. Has been done. Therefore, the support device 9 generally installs the X-ray generator 1 and the X-ray detector 3 so that the optical axis is perpendicular to the pipe 2, but the pipes 2 overlap each other on the optical axis. If the optical axes of the X-ray generator 1 and the X-ray detector 3 match, the X-ray generator 1 and the X-ray detector 3
And are adjusted so that they can be turned up and down or left and right.

The X-ray transmission information detected by the X-ray detector 3 is converted by the information converter 5 into conversion information that can be handled by the analysis device 6 and sent to the analysis device 6. The analysis device 6 performs image analysis on the conversion information converted by the information converter 5 according to a predetermined procedure described below, and outputs the analysis information. Then, the analysis information analyzed by the analysis device 6 is recorded in the recording device 7 as needed. The recording device 7 is also used to previously record design information regarding the pipe 2 before thinning.

Further, if necessary, X-ray transmission information and / or
Alternatively, the conversion information and / or the analysis information is displayed on the display device 8. In the description of the above embodiment, “X-ray transmission information”, “conversion information” and “analysis information” are referred to for convenience, but if these three pieces of information may be the same, Therefore, all of them can be collectively referred to as radiation transmission information (that is, X-ray transmission information).

When investigating the state of metal thinning, it is not possible to specify where in the pipe the metal thinning exists, and it may be difficult to evaluate the above method by the above method depending on the place where the metal thinning exists.
When obtaining the information on X-ray transmission, X-ray transmission is performed by rotating 90 ° or 120 ° about the longitudinal direction of the pipe with the condition that the generator, the detector and the pipe are on the same axis across the pipe. Get information.

Next, the pipe thinning condition evaluation method according to the present invention will be described.

FIG. 3 is a diagram showing a pipe thinning condition evaluation method according to an embodiment of the present invention. (A) shows the pipe to be surveyed, and (b) shows the vertical section. An example of a method of grasping the thinned portion 4 of the pipe 2 from the X-ray transmission information of the pipe is shown.

In FIG. 3, when the pipe 2 is irradiated with X-rays by using the evaluation device shown in FIG. 1 to obtain X-ray transmission information, the "X" of the pipe 2 is displayed on the screen of the display device 8 described above. The image of the transparent image information 11 ”as the line transparent information is projected.

As shown in (c), the transparent image information 11
When the value of each pixel data existing on the straight line connecting the axes Z1 and Z2 extending vertically in the center of the screen is extracted and plotted, the density distribution 13 of pixel values in each pixel is obtained as shown in (d). To be In other words, the direction of the axis Z1-Z2 is a direction that vertically traverses the thinned portion 4 of the pipe 2 installed horizontally. Then, by sequentially moving the axes Z1-Z2 in the horizontal direction (scanning the Z axis), the density distribution 13 of pixel values in each pixel is obtained for all image sections of the transmission image information 11. To be

As shown in (e), the reference pipe composite image information 17 is obtained as the reference information having the reference pipe information 18 in which the thinned portion does not exist in the pipe portion. Similar to the transmission image information 11, the reference pipe composite image information 17 is used for the axes Z1-Z2.
When each pixel data is extracted by scanning along the line, a reference pipe concentration distribution 19 of pixel values of each pixel is obtained as shown in (f).

Next, the above-mentioned transparent image information 11 and (g)
As shown in (4), the logical subtraction processing 20 is performed from the reference pipe composite image information 17, in other words, by superimposing the radiation transmission information and the reference information, as shown in (h), the pipe portion is thinned. The thinned portion transmission image information 21 as the overlay transmission information having the thinned portion transmission information 22 that emerges as an image in which only the portion 4 is projected is obtained. When each pixel data is taken out by scanning along the axis Z1-Z2, the thinned portion density distribution 23 of the pixel value in each pixel is obtained as shown in (i). This thinning part concentration distribution 2
From 3, it is possible to extract the grayscale data (that is, the grayscale value) of only the thinned portion 4. In other words, it is possible to identify the presence or absence of the thinned portion.

The thinned portion concentration distribution 23 corresponds to the displacement portion 25 shown as the concentration distribution 13 described above. Further, in this embodiment, since the grayscale data is acquired from the screen image (that is, the area sensor), it is possible to scan in the longitudinal direction of the pipe, for example, in order to acquire the data as the area, and the data acquisition The effect of being efficient is born.

FIG. 4 is a diagram showing a pipe thinning state evaluation method using the radiation transmission information of the gray value for each unit pixel according to the embodiment of the present invention. That is, from the “superimposed transmission information as X-ray transmission information” for the thinned portion 4, the thinned portion 4
An example of a method for obtaining the thinned state of is shown. Further, in FIG. 4, an enlarged image 24 in which an arbitrary pixel portion is enlarged is shown.
It is shown.

In FIG. 4, the thinned portion transmission information screen 41 as overlay transmission information is disassembled for each unit pixel 42,
A value represented by each memory for each unit pixel (that is, the thinned portion transmission information for each unit pixel of the thinned portion transmission information), that is, the grayscale value for each unit pixel displayed on the image (or
What is called a gradation value) is taken out. The extracted gray value means the “thickness of the thinned portion 4” as the depth dimension of the thinned portion in the unit pixel. In other words, the method or means for converting the gray value (or gradation value) corresponding to each unit pixel into the thickness of the thinned portion for each unit pixel is characterized by the pipe thinning state evaluation according to the present invention. .

Then, with the depth dimension as height and the size of the unit pixel as the bottom area, they are multiplied to obtain the minute volume (ΔC) of the thinned portion 4 corresponding to each unit pixel. still,
Examples of gradation values include 256 gradations and 1024 gradations, and the larger the number of gradations, the larger the resolution with respect to the gradation value. As a specific example, when the area (size) of the unit pixel is set to 0.18 mm square and the image is taken with 256 gradations, the error with respect to the true value obtained by separate decomposition is 5
%Met. Of course, the size of the unit pixel can be arbitrarily changed.

Next, each ΔC is obtained for the area range of the thinned portion 4 indicated by the thinned portion transmission information, and all of them are added to obtain the volume C of the thinned portion 4. By multiplying the volume C by the density ρ which is the predicted value of the thinned portion, the weight W of thinned portion of the thinned portion is obtained.

FIG. 5 is a diagram showing a conversion curve (a) and a conversion table (b) for converting the thickness of the thinned portion from the density distribution. That is, it shows a conversion table created from a conversion curve or a conversion curve relating to "shade value-thickness of thinned portion" for converting and obtaining the thickness of the thinned portion from the gray value as the above-mentioned density distribution. The conversion curves a, b, and
c shows the difference depending on the parameter of the investigation condition.
For example, the parameters of the investigation conditions include the difference in the type of the thinned portion, the difference in the material and shape of the pipe, and the like. Then, according to the present embodiment, the effect that the processing time of the analysis device can be shortened is obtained.

FIG. 6 is a diagram showing a method of correcting the gray value according to the investigation condition. It shows a method of correcting the investigation error (or measurement error) of the gray value of the X-ray transmission information due to the investigation condition (or measurement condition) based on the X-ray transmission information of the pipe. For example, as the inspection conditions, “the installation position of the pipe (for example, the relationship that the distance between the a pipe and the X-ray generator 1 or the X-ray detector 3 is long / near)”, “energy generated by the X-ray generator (X If the relations between the values of the X-ray tube current or the X-ray tube voltage are large or small) ", the recording device has basic data captured under several different conditions for each investigation condition in advance. By comparing the basic data and the X-ray transmission information and changing the conversion curve or the conversion table, the investigation error (or measurement error) of the gray value can be corrected. The case where the conversion curve relating to the thickness value-thickness portion shown in (a) is changed from the curve A shown in (b) to the curve B, or the interpolation between the curves A and B is performed, 6 illustrates. The same can be done with the conversion table. And according to this embodiment,
This has the effect of reducing the capacity of the recording device.

FIG. 7 is a diagram showing a flow for obtaining the weight reduction weight of the thickness reduction part of the embodiment according to the present invention. Step 1 is a flow chart for obtaining the weight of the thinned portion 4 of the pipe 2 which is not horizontally arranged (other than horizontally arranged) in the processing system equipment.
This is shown in (S21) to step 10 (S30).
The contents of each step are as shown in the figure. That is,
X-ray generator and X to the place you want to measure in the pipe or container
The line detector is moved (S21). X-ray imaging (A) is performed (S22). The lightness (gradation value) of the vertical cross section with the pipe is checked (S23). Pipe diameter (preliminary value along with wall thickness)
The ratio of the size of one pixel to the actual size is calculated based on (S2
4). Based on the shape database of the pipe or container (preliminary value as design information), the density data of the state before use is created in accordance with (A) (B) (S25). (A) is subtracted from (B) to obtain (C) (S26). The depth (thickness) is obtained from the gray value (gradation value) (S27). Every pixel (one memory)
Is calculated (S28). Add up the volumes (S2
9). Calculate the weight by multiplying the pipe density (preliminary value) (S3
0).

The feature of the present embodiment shown in FIG. 7 is that it utilizes design information recorded in advance regarding the thinning condition of the pipe, that is, reference information formed from past performance data of the processing system equipment.

That is, the thinning state is grasped by superimposing it on the radiation transmission information which is considered to have generated the thinning portion.

According to this embodiment, it is possible to evaluate the state of the thinned portion regardless of the shapes of the pipe and the container, and also for the constituent equipment other than the pipe and the container.

[0040]

According to the present invention, it is possible to quantitatively grasp the state of pipe or container thinning without disassembling and non-destructing, so operation stop and analysis work due to disassembly inspection are eliminated, and the operation efficiency of equipment is eliminated. It has the effect of improving the inspection work efficiency and safety. In addition, the ability to perform measurement diagnosis without disassembling and non-destructing also has the effect of shortening the time for investigating the state of metal thinning.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a pipe thinning state evaluation device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the details of the pipe thinning state evaluation device of FIG.

FIG. 3 is a diagram showing steps for a pipe thinning state evaluation method according to an embodiment of the present invention.

FIG. 4 is a diagram showing a method of evaluating a thinned state of a pipe according to an embodiment of the present invention.

FIG. 5 is a diagram showing a conversion curve and a conversion table for converting the thickness distribution to the thickness reduction portion from the concentration distribution.

FIG. 6 is a diagram showing a method of correcting a gray value according to an investigation condition.

FIG. 7 is a flow chart showing a flow for obtaining the weight reduction amount of the thickness reduction portion according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... X-ray generator, 1a ... X-ray, 2 ... Piping, 3 ... X-ray detector, 4 ... Thin portion, 5 ... Information converter, 6 ... Analysis device, 7 ...
Recording device, 8 ... Display device, 9, 9a, 9b ... Supporting device,
10 ... Heat insulating material, 11, 31 ... Transmission image information, 12 ... Piping site information, 13 ... Concentration distribution, 17 ... Standard piping composite image information, 18 ... Standard piping information, 19 ... Standard piping concentration distribution, 2
0 ... Logical subtraction processing, 21 ... Transparent image information of thinned portion, 22 ...
Thinned portion transmission information, 23 ... Thinned portion concentration distribution, 32 ... Piping site information.

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 23/00-23/227 G01N 21/00-21/01 G01N 21/17-21/61 G01N 29/00-29 / 28 G01N 27/72-27/90 PATOLIS

Claims (4)

(57) [Claims] 1. A pipe or the like previously recorded by using radiation transmission information of a gray value for each unit pixel of the pipe or the like obtained by irradiating the pipe or the like with radiation such as X-rays from the outside.
Reference information formed from the design information of the
A method for evaluating a thinning state of a pipe or the like, characterized by performing image analysis by superimposing the information on the information to evaluate the thinning state of the pipe or the like. 2. The image analysis for evaluating the amount of thinning as the thinning state according to claim 1, wherein the overlay transmission information obtained by the overlay is decomposed into each unit pixel, and each unit pixel is analyzed. (3) The thinning evaluation method for a pipe or the like, wherein: each of the overlay transmission information is obtained by converting the depth dimension of the thinning for each unit pixel from the gray value displayed on the image. 3. A thin-walled state evaluation device for a pipe, such as a radiation generator and a radiation detector, which are arranged to face each other with a pipe or the like to be investigated of a processing system for transporting a certain substance or fluid interposed therebetween, wherein the radiation generator Radiation is radiated to the pipe or the like from the radiation, and the radiation transmission information of the gray value for each unit pixel for the inside of the pipe or the like obtained by the radiation detector from the transmitted radiation is input and recorded in advance. It is characterized by comprising an analysis device for performing image analysis by superimposing the radiation transmission information and the reference information formed from the design information of the pipe or the like, and evaluating the thinning state inside the pipe or the like. Evaluation device for thinning condition of piping. 4. The method of claim 3, wherein the image analysis to assess the thickness reduction of as the thinning condition decomposes the superimposed transmission information obtained by the superposition for each unit pixel, the unit for each pixel Is obtained by converting the depth dimension of the metal thinning for each unit pixel from the grayscale value displayed on the image by each of the overlay transmission information.