Method for inspecting the contents of a container

Abstract

To provide an inspection method for a storage state of a container and an inspection device for a storage state of a container which can inspect a storage state of a container that stores a storage article in a short time.SOLUTION: An inspection method for inspecting a storage state of a container 20 which stores a storage article 30 uses an inspection device 100 and first heats a bottom surface 23 being an inspection surface located on an outer surface of the container 20 with a heat source 120, then measures the temperature distribution of the bottom surface 23 heated by the heat source 120, and determines that there is a charging defective part 21B in a bottom part 21 of the container 20 when there are spots where the temperature difference is greater than a predetermined reference difference in the temperature distribution of the bottom surface 23 acquired by the measurement.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method for inspecting the accommodation state of a container in which an object is accommodated. In the law

Background Art

[0002] Conventionally, for example, there has been a case where the quality of the inside of a container in which an object is accommodated is inspected without destroying the container. For example, Patent Document 1 describes a method for inspecting the contents filled in a package using ultrasonic waves.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method for inspecting the inside of a container using ultrasonic waves as in the above-described conventional technique, there has been a problem that the inspection time becomes long depending on the inspection content.

[0005] The problem of the disclosed technology is to provide a method for inspecting the accommodation state of a container that can inspect the accommodation state of a container in which an object is accommodated in a short time. Law

Means for Solving the Problems

[0006] A method for inspecting the accommodation state of a container according to one aspect of the disclosed technology is a method for inspecting the accommodation state of a container, which heats an inspection surface located on the outer surface of a container in which an object is accommodated, measures the temperature distribution of the heated inspection surface, and determines the quality of the accommodation state of the container based on the temperature distribution of the inspection surface obtained by the measurement. A method for inspecting the condition of a container's contents, in which, if the temperature distribution of the inspection surface obtained by measurement contains high-temperature areas and low-temperature areas where the temperature difference between them is greater than a predetermined standard difference, the container's contents are judged to be in a poor condition.

[0007] ​​​If there are areas on the inside of the inspection surface that are in contact with the contents and areas that are not, there will be a difference in the degree of temperature rise of the inspection surface when heated. In other words, if there are areas on the inside of the inspection surface that are in contact with the contents and areas that are not, a temperature difference will be created on the inspection surface when heated. Therefore, by obtaining the temperature distribution of the heated inspection surface, it is possible to confirm the areas on the inside that are in contact with the contents and areas that are not, and based on this, the quality of the contents in the container can be determined. This method of inspecting the contents of a container can be carried out by heating for a time that is sufficient to create a temperature difference between the areas on the inside of the inspection surface that are in contact with the contents and areas that are not, and it can be done in a short time. Furthermore, when the temperature distribution of the inspection surface obtained through measurement shows high-temperature and low-temperature areas where the temperature difference between them is greater than the standard difference, it can be determined that the container's contents are in poor condition. This allows for the identification of containers with poor contents in a short inspection time.

[0009] Furthermore, in the method for inspecting the contents of a container as described above, it is desirable that, within a predetermined inspection period from the start of heating of the inspection surface, if there are no areas in the temperature distribution of the inspection surface obtained by measurement where the temperature difference is greater than the standard difference, the container is not judged to have a poor contents condition. In this way, containers with good contents conditions can be identified in a short inspection time.

[0010] Furthermore, in the method for inspecting the contents of a container as described above, it is preferable that the inspection surface be the bottom surface of the container. In this way, it is possible to determine whether the contents are in good condition at the bottom of the container, which is difficult to check when the contents are placed inside. [Effects of the Invention]

[0014] According to the disclosed technology, a method for inspecting the state of contents in a container that contains contents can be inspected in a short time. The law It is available. [Brief explanation of the drawing]

[0015] [Figure 1] This is a cross-sectional view of the object to be inspected (a container containing contents) according to the embodiment. [Figure 2] This is a schematic diagram of the inspection device according to the embodiment. [Figure 3] This is a perspective view of the inspection device according to the embodiment. [Figure 4] This is a diagram illustrating the principle of the inspection method according to the embodiment. [Figure 5] This figure shows the temperature distribution of the inspection surface after a predetermined time has elapsed since the start of heating of the container according to the example. [Figure 6] This figure shows the temperature distribution of the inspection surface after a longer period of time has elapsed since the start of heating the container according to the example, compared to the time shown in Figure 5. [Figure 7] This figure shows the filling defects found when the container according to the example was disassembled. [Modes for carrying out the invention]

[0016] A method for inspecting the contents of a container and an apparatus for inspecting the contents of a container, which are embodiments of the disclosed technology, will be described in detail with reference to the drawings.

[0017] First, let's explain the inspection target 10 as an example of an object to be inspected, using Figure 1. Figure 1 is a cross-sectional view of the inspection target 10. The inspection target 10 has a container 20 and contents 30 housed inside the container 20. The container 20 is made of metal, for example, which does not transmit visible light. Therefore, it is difficult to directly observe the contents from the outside. Specifically, the container 20 in this embodiment is a 200L drum. That is, the container 20 in this embodiment is made of steel, and is made of a material that may rust if water remains inside for a long period of time.

[0018] The contents 30 are, for example, waste. The contents 30 in this embodiment include solid material 31 and mortar 32. The solid material 31 in this embodiment is radioactive waste. In this embodiment, after the solid material 31 is placed inside the container 20, the mortar 32 is filled into the gaps between the solid material 31 and the gaps between the solid material 31 and the container 20.

[0019] In such a container 20, it is preferable that the mortar 32 is properly filled inside the container 20. For example, if the mortar 32 is not properly filled near the bottom 21 inside the container 20, moisture may accumulate in the gap between the inner surface 22 of the bottom 21 and the mortar 32. And if water continues to accumulate at the bottom 21 over a long period of time, there is a possibility that the container 20 will rust. The mortar 32 accommodated into the container 20 will first cover the inner surface 22 of the bottom 21 of the container 20. Also, both the container 20 and the contained object 30 do not transmit visible light. That is, it is difficult to confirm whether the mortar 32 is properly filled on the inner surface 22 of the bottom 21 of the container 20 even after the contained object 30 is accommodated and at the time of accommodating the contained object 30.

[0020] Next, an inspection device 100 for inspecting the accommodation state of the container 20 will be described. The inspection device 100 inspects an inspection surface located on the outer surface of the container 20. In this embodiment, the inspection surface is the bottom surface 23 which is the outer surface of the bottom 21 of the container 20. As shown in the schematic configuration diagram of FIG. 2, the inspection device 100 has a mounting plate 110, a heating source 120, and a temperature measurement unit 130. The mounting plate 110 has the container 20 placed on its upper surface during inspection. The mounting plate 110 has a through hole 111 formed at a position corresponding to the bottom surface 23 of the bottom 21 of the placed container 20. The through hole 111 is slightly smaller than the bottom surface 23 of the container 20. Therefore, when placed on the mounting plate 110, most of the bottom surface 23 of the container 20 can be exposed inside the through hole 111.

[0021] The heating source 120 can heat the container 20 from the outside. In the inspection apparatus 100 of this embodiment, a first heating source 120A and a second heating source 120B are provided as the heating source 120. In this embodiment, both the first heating source 120A and the second heating source 120B are infrared heaters. The first heating source 120A and the second heating source 120B are provided at positions diagonally below the through hole 111 in different arrangements. The first heating source 120A and the second heating source 120B emit infrared rays toward the bottom surface 23 of the container 20 exposed inside the through hole 111 from different positions. Thereby, the first heating source 120A and the second heating source 120B can heat the bottom surface 23 of the container 20, which is the inspection surface. In this embodiment, by using an infrared heater as the heating source 120, the bottom surface 23 of the container 20, which is the inspection surface, can be accurately heated in a short time. Also, the infrared heater can heat the bottom surface 23 of the container 20 from a distant position.

[0022] The temperature measurement unit 130 can measure the temperature distribution of the container 20 from the outside of the container 20. The temperature measurement unit 130 of this embodiment includes an infrared thermography camera. The temperature measurement unit 130 includes at least the bottom surface 23 of the container 20 exposed inside the through hole 111 within the imaging range. Therefore, the temperature measurement unit 130 can measure the temperature distribution of the bottom surface 23 of the container 20, which is the inspection surface. In this embodiment, by using an infrared thermography camera as the temperature measurement unit 130, the temperature distribution of the bottom surface 23, which is the inspection surface, can be easily obtained non-contact from the image of the bottom surface 23 of the imaged container 20. As the infrared thermography camera of the temperature measurement unit 130, for example, InfReC R450 manufactured by Nippon Avionics Co., Ltd. can be used.

[0023] FIG. 3 is a perspective view of the inspection apparatus 100. As shown in FIG. 3, the inspection apparatus 100 has a pedestal 115 below the mounting plate 110. The mounting plate 110 is provided on the upper part of the pedestal 115. Thereby, a space 112 is formed below the mounting plate 110. The pedestal 115 can be configured, for example, by connecting a plurality of steel pipes.

[0024] The base 115 has a first heat source support section 116A and a second heat source support section 116B on which the first heat source 120A and the second heat source 120B are placed, respectively. As can be seen in Figure 3, the first heat source 120A and the second heat source 120B are arranged facing each other in the horizontal direction, with the bottom surface 23 of the container 20 positioned between them. The temperature measuring unit 130 is positioned diagonally below the container 20. The temperature measuring unit 130 is also positioned between the first heat source 120A and the second heat source 120B. This arrangement prevents the infrared thermography camera of the temperature measuring unit 130 from measuring the infrared radiation emitted by the first heat source 120A and the second heat source 120B, which are infrared heaters. In other words, the temperature measuring unit 130 can accurately acquire the temperature distribution of the bottom surface 23 of the container 20.

[0025] Furthermore, in an inspection device 100 that uses an infrared thermography camera in the temperature measurement unit 130, it is preferable that infrared radiation incident from outside the device into the imaging range of the temperature measurement unit 130 can also be reduced. This is because the temperature measurement unit 130 can accurately acquire the temperature distribution of the bottom surface 23 of the container 20. Therefore, it is preferable that the inspection device 100 has a light-shielding section that suppresses infrared radiation incident in the imaging direction of the temperature measurement unit 130. Specifically, for example, it is preferable to provide a film that shields infrared radiation on the sides 115A, 115B, and 115C of the base 115 located in front of the infrared thermography camera of the temperature measurement unit 130. This makes it possible to suppress infrared radiation from the outside from entering the space 112 below the mounting plate 110. In other words, the temperature measurement unit 130 can accurately acquire the temperature distribution of the bottom surface 23 of the container 20.

[0026] Next, an inspection method for inspecting the contents of the container 20 using the inspection device 100 will be described. First, the inspection principle will be explained. Figure 4 shows the temperature changes of the well-filled portion 21A and the poorly filled portion 21B when the bottom 21 of the container 20 is heated.

[0027] The well-filled portion 21A is the part of the bottom portion 21 in which the mortar 32 is properly filled. In other words, the well-filled portion 21A is the part of the bottom portion 21 in which the mortar 32 is in contact with the inner surface 22. The poorly filled portion 21B is the part of the bottom portion 21 in which the mortar 32 is not properly filled. In other words, the poorly filled portion 21B is the part of the bottom portion 21 in which the mortar 32 is not in contact with the inner surface 22.

[0028] When the bottom 21, which contains both well-filled areas 21A and poorly filled areas 21B, is heated, the temperature changes differ between the two areas. Specifically, the poorly filled areas 21B tend to heat up more easily than the well-filled areas 21A. In the well-filled areas 21A, where the mortar 32 is in contact with the inner surface 22, heat is easily transferred to the mortar 32 when heated. Therefore, heat is easily transferred to the outside of the well-filled areas 21A, and the temperature does not rise easily. In contrast, in the poorly filled areas 21B, where the mortar 32 is not in contact with the inner surface 22, there is air on the inner surface 22 side, which has a lower thermal conductivity than the mortar 32. Therefore, heat is not easily transferred to the outside of the poorly filled areas 21B, and the temperature rises easily.

[0029] Therefore, as shown in Figure 4, at time t1, after a predetermined time has elapsed since the start of heating, the temperature TA of the well-filled portion 21A is lower than the temperature TB of the poorly filled portion 21B. In this embodiment, the presence or absence of a poorly filled portion 21B at the bottom 21 is inspected based on the temperature difference between the well-filled portion 21A and the poorly filled portion 21B that occurs during heating. Note that the temperature difference between the well-filled portion 21A and the poorly filled portion 21B is small in the initial stages after the start of heating, and then increases as time passes. If heating continues, the temperature difference between the well-filled portion 21A and the poorly filled portion 21B will eventually decrease and they will be at the same temperature. For this reason, in this embodiment, the inspection is performed at a timing before the well-filled portion 21A and the poorly filled portion 21B reach the same temperature after the start of heating.

[0030] Next, the procedure for inspecting the contents of the container 20 using the inspection device 100 will be described in detail. In this inspection method, first, the container 20 containing the contents 30 is placed on the mounting plate 110 of the inspection device 100. At this time, the center of the bottom 21 of the container 20 is aligned with the through hole 111 of the mounting plate 110. This exposes the bottom 21 of the container 20 to the inside of the through hole 111.

[0031] With the container 20 placed on the mounting plate 110, the bottom 21 is heated by the heating source 120. Both the first heating source 120A and the second heating source 120B are used during heating. This allows the temperature of the bottom 21 to be raised in a shorter time than if only one of them were used. In other words, using multiple heating sources can shorten the time required for inspection.

[0032] After heating by the heating source 120 is started, the temperature distribution of the bottom 21 is measured and obtained by the temperature measurement unit 130. If, within a predetermined inspection time from the start of heating by the heating source 120, areas with a temperature difference greater than a predetermined reference difference are found in the temperature distribution of the bottom 21, it is determined that the container 20 has a poorly filled area 21B. In other words, it is determined that there is a part near the bottom 21 inside the container 20 where the contents 30 are not properly filled, and the storage condition is poor. In this embodiment, for containers 20 determined to have a poor storage condition, the contents 30 are removed and the removed contents 30 are placed back into another container 20. After placing the contents 30 into a different container 20, the same inspection is performed again on that container 20 using the inspection device 100.

[0033] On the other hand, if, within the inspection time after the start of heating by the heat source 120, no areas with a temperature difference greater than the standard difference are found in the temperature distribution of the bottom 21, then it is determined that there are no defective parts 21B in that container 20. In other words, it is determined that the contents 30 are properly filled throughout the bottom 21 of the container 20 and that the contents are in good condition.

[0034] When using the inspection device 100 and performing the inspection in this procedure, the time required for the inspection is only necessary to create a temperature difference between the well-filled portion 21A and the poorly filled portion 21B due to heating. In other words, the inspection time is short. Furthermore, by obtaining the temperature distribution of the bottom 21 and confirming whether there are any areas where the temperature difference is greater than the reference difference, the temperature of the bottom 21 before inspection does not affect the inspection results. In other words, with this inspection method that uses the relative temperature change in the temperature distribution of the bottom 21, accurate inspection results can be obtained regardless of whether the temperature of the bottom 21 before inspection is at room temperature, lower than room temperature, or higher than room temperature.

[0035] Each inspection condition, such as the inspection time for acquiring the temperature distribution after heating begins, and the criteria for the temperature difference used to determine the presence of a filling defect 21B, can be determined in advance by conducting experiments using a container 20 having a filling defect 21B. For example, the inspection time for acquiring the temperature distribution after heating begins can be about 60 to 90 seconds. For example, the criteria for the temperature difference used to determine the presence of a filling defect 21B can be about 1 to 2°C.

[0036] The presence or absence of a filling defect 21B can be determined, for example, by an inspector visually checking the temperature distribution image acquired for the bottom surface 23. Alternatively, the inspection device 100 may be equipped with a determination unit capable of performing a determination process to determine whether or not there are areas where the temperature difference is greater than a reference difference, based on the temperature distribution image acquired for the bottom surface 23.

[0037] Furthermore, the timing for acquiring the temperature distribution used to determine the presence or absence of a filling defect 21B may be set to a timing after a predetermined time has elapsed since the start of heating. Specifically, for example, the presence or absence of a filling defect 21B can be determined using an image of the temperature distribution 60 seconds after the start of heating. Alternatively, for example, the temperature distribution may be acquired at multiple different timings after the start of heating, and the presence or absence of a filling defect 21B may be determined using multiple temperature distributions acquired at different timings. In this case, for example, if there is one or more locations among the multiple temperature distributions acquired at different timings where the temperature difference is greater than the reference difference, it can be determined that there is a filling defect 21B. Alternatively, for example, if there are multiple locations among the multiple temperature distributions acquired at different timings where the temperature difference is greater than the reference difference, it can be determined that there is a filling defect 21B.

[0038] In this inspection method, the bottom surface 23 of the container 20 is used as the inspection surface. Therefore, it is possible to confirm whether the contents 30 are properly contained in the area near the bottom 21 of the container 20, which is difficult to check both after the contents 30 are contained and when the contents 30 are contained. Furthermore, it is possible to properly identify containers 20 that have areas near the bottom 21 where moisture may accumulate during storage.

[0039] Furthermore, the inspection can be performed with the bottom 21 of the container 20 facing downwards. This allows the bottom 21 of the container 20 to be inspected in the same position as under normal storage conditions. In other words, if the container 20 is inspected in a position different from that under normal storage conditions, the inspection results may not correspond to normal storage conditions due to uneven distribution of the contents 30, etc. In contrast, by performing the inspection with the bottom 21 of the container 20 facing downwards, accurate inspection results that match the storage conditions of the container 20 can be obtained.

[0040] Next, an embodiment of this example will be described. In this embodiment, the container 20 containing the contents 30 was inspected using the inspection device 100 in the procedure described above. For the inspection in this embodiment, a container 20 provided with a filling defect 21B was used. Figures 5 and 6 show the temperature distribution obtained by measuring the bottom surface 23 of the container 20 according to the embodiment. Both Figures 5 and 6 show the temperature distribution obtained from the same container 20.

[0041] Figure 5 is an image showing the temperature distribution of the bottom surface 23 of the container 20 measured 15 seconds after the start of heating. Figure 6 is an image showing the temperature distribution of the bottom surface 23 of the container 20 measured 60 seconds after the start of heating. In the temperature distribution at 15 seconds shown in Figure 5, no significant temperature difference is clearly visible. In contrast, in the temperature distribution at 60 seconds shown in Figure 6, three high-temperature areas TH, which are hotter than the rest of the container, can be clearly identified. High-temperature areas TH are areas where the temperature difference from the bottom surface 23 other than the high-temperature areas TH is large.

[0042] Figure 7 shows the defective filling portion 21B confirmed by disassembling the container 20 used in the inspection according to the embodiment after acquiring the images in Figures 5 and 6. Specifically, Figure 7 was created by disassembling the container 20 used in the embodiment, removing the bottom portion 21, and checking whether or not mortar 32 was attached. In Figure 7, the defective filling portion 21B, which is the part of the bottom portion 21 where mortar 32 was not attached, is indicated by hatching.

[0043] From Figures 6 and 7, it was confirmed that the high-temperature area TH, which was identified by the temperature distribution image after 60 seconds, corresponds to the location and size of the filling defect 21B. This embodiment confirmed that by using the inspection device 100 and the inspection method described in this embodiment, containers 20 having a filling defect 21B can be appropriately identified.

[0044] Furthermore, in this embodiment, it was confirmed that the inspection time could be as short as 60 seconds. In contrast, for example, when inspecting the entire bottom 21 for the presence or absence of filling defects 21B using ultrasound, it took several tens of minutes. In other words, the inspection method using the inspection device 100 according to this embodiment can complete the inspection in a shorter time compared to other inspection methods.

[0045] Furthermore, other experiments according to this embodiment confirmed that the inspection method using the inspection device 100 according to this embodiment can detect even small filling defects 21B of a few millimeters. Therefore, the inspection method using the inspection device 100 according to this embodiment can accurately determine the state of the contents 30 in the container 20. In other words, it can accurately identify containers 20 with a poor state of contents.

[0046] As explained in detail above, the inspection method according to this embodiment is a method for inspecting the condition of the contents 30 contained in a container 20. The procedure involves using an inspection device 100 to first heat the bottom surface 23, which is the inspection surface located on the outer surface of the container 20, with a heating source 120. Next, the temperature distribution of the bottom surface 23 heated by the heating source 120 is measured. If there are areas in the temperature distribution of the bottom surface 23 obtained by measurement where the temperature difference is greater than a predetermined standard difference, it is determined that there is a poorly filled area 21B in the bottom 21 of the container 20. In other words, it is determined that the condition of the contents 30 is poor because the mortar 32 of the contents 30 is not properly present in the areas of the bottom 21 where the temperature is high. That is, the temperature distribution of the heated bottom surface 23 of the container 20 is measured, and the quality of the contents of the container 20 is determined based on the measured temperature distribution of the bottom surface 23. The time required for inspection using this method is limited to the time it takes for the heating to create a temperature difference between the well-filled area 21A and the poorly filled area 21B. This has resulted in the realization of a method and apparatus for inspecting the condition of contents in a container, which allows for the inspection of the contents of the container in a short amount of time.

[0047] This embodiment is merely illustrative and does not limit the disclosed technology in any way. Therefore, the disclosed technology can naturally be improved and modified in various ways without departing from its essence. For example, the above embodiment described an example where the container 20 is a drum and the contents 30 consist of solid material 31 and mortar 32. However, these are merely examples to illustrate the disclosed technology, and the disclosed technology can be similarly applied to other objects of inspection, as long as the thermal conductivity of the contents 30 is not the same as that of air.

[0048] In the above embodiment, the inspection surface was described as the bottom surface 23 on the outer surface of the container 20. However, it is also possible to use a surface other than the bottom surface 23 as the inspection surface and inspect whether the contents 30 are properly contained inside that inspection surface. However, if there is a possibility that liquid components may accumulate at the bottom 21 when the container 20 is stored, and the bottom 21 of the container 20 may deteriorate due to the liquid components accumulated at the bottom 21, it is preferable to use the bottom surface 23 of the container 20 as the inspection surface. In this case, it is also preferable that the inspection device 100 and the inspection method using the same inspect the container 20 with the bottom surface 23 facing downwards, similar to its storage state.

[0049] In the above embodiment, an example was specifically described in which the storage condition of the container 20 is determined to be poor when there are areas in the temperature distribution of the heated bottom surface 23 where the temperature difference is greater than a predetermined reference difference. However, for example, even if there are areas in the temperature distribution of the heated bottom surface 23 where the temperature difference is greater than a reference difference and there are poorly filled areas 21B, if their size is within a predetermined allowable area, the storage condition may not be determined to be poor.

[0050] For example, the inspection surface can be the side of the container 20, and the height of the contents 30 inside the container 20 can be inspected. Specifically, by heating the side of the container 20 and measuring the temperature distribution of the heated side, a temperature difference will be created between the areas where the contents 30 are present and the areas where the contents 30 are not. In other words, it is possible to confirm the height of the contents 30 inside the container 20. Furthermore, by setting an acceptable range for the height of the contents 30, the quality of the contents in the container 20 can be determined by whether or not the height of the contents 30 obtained from the temperature distribution of the side of the container 20 is within the acceptable range.

[0051] In the above embodiment, an example was described in which the quality of the contents of the container 20 was determined solely by the temperature distribution of the heated bottom surface 23. However, other inspections may also be performed on the container 20. [Explanation of Symbols]

[0052] 20 containers 23 Bottom surface (inspection surface) 30 Containment 100 Inspection device 110 Mounting plate 111 Through hole 120 Heating source 130 Thermometer side

Claims

1. The inspection surface located on the outer surface of the container containing the contents is heated, The temperature distribution of the heated inspection surface is measured, A method for inspecting the condition of a container's contents, which determines whether the container's contents are in good condition based on the temperature distribution of the inspection surface obtained by measurement, A method for inspecting the condition of a container's contents, wherein, in the temperature distribution of the inspection surface obtained by measurement, if there are high-temperature areas and low-temperature areas where the temperature difference between them is greater than a predetermined standard difference, the container's contents are determined to be in a poor condition.

2. A method for inspecting the contents of a container according to Claim 1, A method for inspecting the condition of a container's contents, wherein, within a predetermined inspection period from the start of heating of the inspection surface, if there are no points in the temperature distribution of the inspection surface obtained by measurement where the temperature difference is greater than the reference difference, the container's contents are not judged to be in a poor condition.

3. A method for inspecting the contents of a container according to claim 1 or claim 2, A method for inspecting the state of contents in a container, wherein the inspection surface is the bottom surface of the container.

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