JP2003185520A - Method and apparatus for inspecting leakage of container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leakage inspection method and a leakage inspection device which are highly reliable, and enable reliable detection of leakage from a gap having a size which is difficult to confirm by the eye. <P>SOLUTION: In place of the conventional leakage inspection method for containers, this method is provided with a differential pressure generating process for generating differential pressure between the inside and the outside of a container, an ozone gas adding process for adding an ozone gas to the higher pressure side of the inside and the outside, an ozone concentration measuring process for measuring the concentration of ozone on the lower pressure side of the inside and the outside, and an existence-of-leakage determining process for determining the existence of leakage of the container by the change of the ozone concentration. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container leak inspection method and a leak inspection device. In particular, the present invention relates to a method for detecting a leak using gas, a method for inspecting a leak of a container having a characteristic structure, and a leak inspection apparatus.

[0002]

2. Description of the Related Art Leak inspection is required in the manufacturing process and the recycling process of containers such as drums and fuel tanks. For example, in a drum for containing liquid without leaking, it is necessary to detect a gap of 50 microns or more. Even if there is a gap of less than 50 microns, it can be considered that the leakage from the container does not actually occur.

[0003] Conventional methods for leak inspection of containers include a liquid immersion method and a soap method. The conventional container leak inspection method will be described below. First, the liquid immersion method will be described. The container is hermetically sealed and a gas (for example, air) is injected into the container to apply pressure. Immerse the pressurized container in a liquid (eg, water). If there is a gap in the container, gas (for example, air) inside leaks from the gap and bubbles are generated on the surface of the container where the gap exists. When the bubbles are visually inspected and confirmed, it is determined that the container has a gap that causes a leak.

Next, the soap method will be described. The container is hermetically sealed and a gas (for example, air) is injected into the container to apply pressure. Apply soapy water to the surface of the container. If there is a gap in the container,
Gas (for example, air) inside leaks from the gap, and soap bubbles are generated on the surface of the container where the gap exists. When the soap bubbles are visually inspected and the soap bubbles are confirmed, it is determined that the container has a gap that causes a leak.

Conventionally, the above-mentioned method has been used to visually inspect the gap that causes the leakage of the container. Immersion method and soap method,
In principle, it is considered possible to find a gap exceeding 50 microns. However, since both methods involve visual inspection by a skilled worker, there was concern about the reliability of detection of a gap in the range of 50 to 100 microns. 50 microns ~
Bubbles or soap bubbles caused by a leak generated from a 100-micron gap were extremely small and were sometimes overlooked by visual inspection. Further, when a leak inspection of the container is performed by the liquid immersion method, a drying step for removing the liquid on the surface is necessary after the leak inspection step. The soap water method requires a washing step and a drying step for removing soap water on the surface after the leak inspection step.

Further, in the conventional leak inspection technique field of a vacuum chamber, a leak inspection method using helium gas is known. However, the leak inspection method using helium gas is not suitable for leak inspection of containers such as drums and fuel tanks because of its too high sensitivity. That is, helium gas has a property of leaking from a gap far smaller than 50 microns, and the detector detects the helium gas leaking from a gap such as a sealing lid of a container, so that it is desired to find 50
The presence or absence of a gap of micron to 100 micron could not be confirmed.

[0007]

In the case of the above-described container leak inspection method, the reliability of finding a gap having a small size (for example, 50 microns to 100 microns) is low because it is a visual inspection method. Further, after the leak inspection process, it is necessary to remove water, soap, etc., which requires time and cost for the subsequent process. Therefore, in place of the conventional liquid immersion method or soap water method, a highly reliable leak inspection method and leak inspection apparatus for inspecting a leak in a narrow gap have been strongly demanded.
Further, there has been a strong demand for a container leak detection method and a leak inspection device that do not require a post-process.

The present invention has been devised in view of the above-mentioned problems, and replaces the conventional container leak inspection method and leak inspection device with leaks from a gap having a size that is difficult to visually confirm. It is intended to provide a leak inspection method and a leak inspection device for a container that can be reliably discovered and have high reliability.

[0009]

In order to achieve the above object, a container leak inspection method according to the present invention comprises a differential pressure generating step of generating a differential pressure between the inside and the outside of the container, and the inside and outside of the container. Ozone gas addition step of adding ozone gas to the high pressure side, ozone concentration detection step of measuring the ozone concentration on the low pressure side of the inside and the outside, and the presence or absence of container leakage due to changes in the ozone concentration And a leak determination step of determining.

With the above-described structure of the present invention, a differential pressure is generated between the inside and the outside of the container in the differential pressure generating step, and ozone gas is added to the side with the higher pressure of the inside and the outside in the ozone gas adding step. In the concentration detection step, the ozone concentration on the lower pressure side of the inside and the outside is measured, and in the leak determination step, the presence or absence of a leak in the container is determined based on the change in the ozone concentration. Since small leaks can be detected with high sensitivity, highly reliable leak determination can be performed in a short time, and leak determination can be performed in a dry environment, post-processing becomes easy.

Further, in the container leak inspection method according to the present invention, the differential pressure generating step includes the step of storing the container in the container and the operation of pressurizing or depressurizing the container or the container. And a container pressure increasing / decreasing step. According to the configuration of the present invention, the container is placed in the container in the container storing step, and one of the container and the storing container is pressurized or depressurized in the container pressurizing / depressurizing step. In this case, the leak determination of the entire container can be performed at one time, and the differential pressure between the inside and the outside of the container is forcibly generated by the operation of pressurization or depressurization, so that the leak determination can be performed in a short time.

Further, in the container leak inspection method according to the present invention, the ozone gas adding step for generating ozone gas from the atmosphere in the ozone gas adding step and the ozone gas supply for supplying the ozone gas to the higher pressure side of the inside and the outside. And a process. With the configuration of the present invention,
Ozone gas is generated from the atmosphere in the ozone gas generation step, and the ozone gas is supplied to the higher pressure side of the inner side and the outer side in the ozone gas supply step, so there is no need to prepare a special gas, and ozone naturally decomposes. Since it returns to air, it does not require troublesome post-treatment.

Further, in the container leak inspection method according to the present invention, in the ozone concentration detecting step, an ozone concentration measuring step of measuring an inner or outer lower ozone concentration by an ozone sensor and a signal corresponding to the measured ozone concentration are transmitted. And an ozone concentration signal output step of outputting. According to the configuration of the present invention, the ozone concentration in the lower portion inside or outside is measured by the ozone sensor in the ozone concentration measuring step, and a signal corresponding to the ozone concentration measured in the ozone concentration signal output step is output. Of large ozone sinks downward, and the ozone sensor at the bottom measures the ozone concentration of the ozone gas, so that the leak determination can be performed quickly.

Further, the container leak inspection method according to the present invention comprises: an ozone concentration comparing step of calculating a concentration difference between the ozone concentration and a predetermined ozone concentration; And an ozone concentration determining step of determining that there is a leak. With the above-described configuration of the present invention, a concentration difference between the ozone concentration and a predetermined ozone concentration is calculated in the ozone concentration comparison step, and it is determined that there is a leak when the concentration difference is greater than a predetermined value in the ozone concentration determination step. Therefore, the leak of ozone gas can be easily determined only by looking at the change in ozone concentration.

Furthermore, in the container leak inspection method according to the present invention, the container is a container for enclosing a liquid. According to the configuration of the present invention, the container is a container for enclosing a liquid, and since the lower limit value of the gap size where ozone gas leaks is close to the lower limit value of the gap size that does not substantially leak the liquid, leakage of the container that encloses the liquid The judgment can be made effectively.

In order to achieve the above object, a container leak inspection apparatus according to the present invention includes a storage container for storing a container in a sealed state and one of a pressurization and a decompression connected to the container or the storage container. A pressure increasing / decreasing device for operating, an ozone gas supplying device for supplying ozone gas to the container or the containment container having a higher internal pressure, and an ozone concentration detecting device for measuring the ozone concentration on the side of the container or the containing container having a lower inner pressure. And, if the ozone concentration exceeds a predetermined value, it is determined that the container has a leak.

According to the above-mentioned structure of the present invention, the storage container stores the container in a sealed state, and the pressurizing or depressurizing device for operating one of pressurization and depressurization communicates with the container or one of the storage containers to supply ozone gas. The instrument supplies ozone gas to the container or the containment vessel with the higher internal pressure, and the ozone concentration detection device measures the ozone concentration on the side of the container or the containment vessel with the lower internal pressure. Since small leaks can be detected with high sensitivity, highly reliable leak determination can be performed in a short time, and leak determination can be performed in a dry environment, post-processing becomes easy.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. In each drawing, common portions are denoted by the same reference numerals, and redundant description will be omitted.

First, a container leak inspection apparatus according to an embodiment of the present invention will be described. FIG. 1 is a conceptual diagram of an apparatus for carrying out an embodiment of the present invention.

First, an example of a container leak inspection apparatus for carrying out the container leak inspection method of the present application will be described. The container leak inspection device 1 is a device for inspecting the container 2 for leaks, and includes a storage container 10, a pressurization / depressurization device 20, an ozone gas supply device 30, an ozone concentration detection device 40, and a leak determination device 50.
With. The container 2 contains a substance (for example, liquid fuel) inside. If there is a minute gap in the wall forming the container 2, the substance leaks from the gap, and is, for example, a drum can. The container leak inspection device 1 is
This is a device that determines whether or not there is a leak due to the gap.

The storage container 10 stores the container 2 inside in a hermetically sealed state, and has a storage container main body 11, a storage container lid 12, and a storage container lid sealing member 13. The main body 11 of the storage container is a substantially cylindrical metal cylinder, and has flanges having sealing surfaces at both ends of the cylinder. The storage container lid 12 is a substantially circular plate that closes both ends of the storage container main body 11, and has a sealing surface on the outer peripheral portion of one surface. A lid penetrating portion 14 is provided at one location of the storage container lid 12. The lid penetrating portion 14 allows the pipe to penetrate from the outside to the inside of the storage container lid 12 while maintaining the airtightness of the storage container lid 12. The storage container lid sealing member 13 is a member that seals the sealing surfaces of the storage container main body 11 and the storage container lid 12, and is, for example, a ring-shaped rubber seal.

The pressurizing / depressurizing device 20 is a device which communicates with one of the container 2 and the storage container 10 and operates one of pressurization and depressurization, and a main valve 21, a depressurizing pump (or pressurizing pump) 22 and an opening. Valve 23. Hereinafter, for convenience of description, as illustrated, the pressurizing / depressurizing device 20 is described as being a device that communicates with the storage container 10 to perform a depressurizing operation.
The main valve 21 is an on-off valve provided in a pipe that connects the inlet side of a vacuum pump 22 described later and the storage container 10 to each other. When the main valve 21 is opened, the air inside the storage container 10 is sucked out by the vacuum pump 22, and the pressure in the storage container 10 drops. The pressurizing / depressurizing pump (vacuum pump in the figure) 22 is one of a pressurizing pump and a depressurizing pump. What is a pressure pump?
It is a pump that supplies gas to the target container to pressurize the inside, for example, an air pump. The decompression device is a pump that decompresses the inside of the target container by decompressing the gas, and is, for example, a vacuum pump. The open valve 23 is an open / close valve provided in a pipe that connects the storage container 10 and the atmosphere. For example, when the pressure inside the storage container 10 is reduced, the opening valve 23
When is opened, the atmosphere flows into the storage container 10. If the pressurizing / depressurizing pump 22 is a vacuum pump, for example, the storage container 10
The inside pressure is reduced to about 0.7K, and the differential pressure between the container 2 and the storage container 10 is set to about 0.3K.

The ozone gas supply device 30 is a device for supplying ozone gas to a container or the above-mentioned storage container having a higher internal pressure, and is an air pump 31, an ozone generator 32, an ozone gas injection valve 33, an ozone gas pressure gauge 34, and ozone gas discharge. It has a valve 35 and an ozone gas injection pipe 36. Hereinafter, for convenience of description, as illustrated, the ozone gas supply device 30 will be described as supplying ozone gas to the container 2. The air pump 31 is a pump that sucks in the atmosphere 3 from the inlet side, raises it to a predetermined pressure, and discharges it from the outlet side.
The outlet side of the air pump 31 communicates with the inlet side of the ozone generator 32 described later. The ozone generator 32 is a device that generates ozone, and injects the air 3 from the inlet side to generate ozone by silent discharge, for example, and emits the ozone gas 4 from the outlet side. Ozone gas is a gas in which carrier gas and ozone are mixed, and in the figure, the carrier gas is air. Normally, 2 if the silent discharge type ozone generator 32 is used.
The ozone gas 4 of about 000 ppm is generated. The ozone gas injection valve 33 is a valve for injecting the ozone gas 4 into the container 2, and is a pipe that connects the outlet side of the ozone generator 32 and the container 2 (hereinafter, referred to as ozone gas injection pipe 36).
It is provided in. The ozone gas injection pipe 36 is connected to the storage container 2
The lid penetrating portion 14 of No. 0 is penetrated. Ozone gas pressure gauge 3
Reference numeral 4 is a pressure gauge that measures the pressure of ozone gas, and is provided in the ozone gas injection pipe 36. Ozone gas release valve 3
5 is an opening / closing valve for lowering the pressure of ozone gas,
It is provided in a pipe that branches from the ozone gas injection pipe 36 and communicates with the atmosphere. Assuming that 2000 ppm of ozone gas is injected into the container 2 filled with the atmosphere and is diluted about 20 times, the ozone concentration in the container 2 is 100 pp.
The order is m.

The ozone concentration detecting device 40 is a measuring device for measuring the ozone concentration on the side of the container or the storage container where the internal pressure is low, and has an ozone sensor 41 and an ozone sensor signal line 42. Hereinafter, for convenience of explanation, as illustrated, the ozone concentration measuring device 40 will be described as a device that measures the ozone concentration of the storage container 10. Ozone sensor 41
Is a sensor that outputs an electric signal 7 (hereinafter referred to as ozone concentration signal 7) corresponding to the ozone concentration of ozone gas, and is, for example, a semiconductor gas sensor. Explaining an example of the ozone sensor, the detection target gas is ozone, the detection range is 0 to 250 ppb, the response time is 30 seconds, the initial rise time is within 10 minutes, and the operating temperature is 0 to 40. C., and the power supply voltage is 8 to 14 V (DC). The detection sensitivity is extremely high compared to semiconductor gas sensors that use other gases as the detection target gas. It is considered that this is because ozone is a highly active gas. The ozone sensor signal line 42 transmits the ozone concentration signal 7 output from the ozone sensor 41 to a leak determination device 50 described later. The ozone sensor signal line 42 penetrates the storage container 10 while maintaining airtightness, and electrically connects the ozone sensor 41 and the leak determination device 50.

The leak determining device 50 is a device for determining that the container 2 has a leak when the ozone concentration in the storage container 10 exceeds a predetermined value, and has an ozone concentration comparator 51 and an ozone concentration determining device 52. . The ozone concentration comparator 51
Ozone concentration signal 7 before injecting ozone gas 4 into container 2
(Hereinafter referred to as reference signal 8) and ozone gas 4 to container 2
It is a device for comparing the ozone concentration signal 7 (hereinafter, referred to as a measurement signal 8) after the injection of. Ozone concentration determiner 52
Is an instrument for determining that there is a leak in the container 2 when the difference between the reference signal 8 and the measurement signal 8 exceeds a predetermined value.

Next, a container leak inspection method according to an embodiment of the present invention will be described. FIG. 2 is a procedure diagram of the embodiment of the present invention. For convenience of description, a case where the leak inspection method is performed using the above-described leak inspection apparatus will be described as an example.

Differential pressure generating step S10: a step of producing a differential pressure between the inside and the outside of the container, which has a container storing step S11 and a container pressurizing / pressurizing step S12. An example will be described in which a container is stored in a storage container, the storage container is depressurized, and a differential pressure is generated between the container and the storage container. The container storage step S11 is a step of putting the container 1 into the storage container 10. The storage container lid 12 of the storage container 10 is removed, and the container 2 is put into the storage container main body 11. The ozone gas injection pipe 36 is communicated with the container 2, and the storage container lid 12 is covered with the storage container main body 11. The container pressurization / depressurization step S12 is a step of operating either pressurization or depressurization of one of the container and the storage container. The open valve 23 and the main valve 21 are opened, and the vacuum pump 22 is operated. The atmosphere enters the storage container 10 via the open valve 23, and is exhausted from the outlet side of the vacuum pump via the main valve 21. When the inside of the storage container 10 is sufficiently replaced with the atmosphere, the open valve 23 is closed. Vacuum pump 2
2 exhausts the air in the storage container 10, and for example, makes the pressure in the storage container about 0.7 k.

Ozone gas adding step S20: This is a step of adding ozone gas to the higher pressure side of the inside and the outside.
Ozone gas generation step S21 and ozone gas supply step S22
Have and. The case where ozone gas is added to the container will be described as an example. The ozone gas generation step is a step of generating ozone gas from the atmosphere. Atmosphere 3 by air pump 31
Is taken up, the pressure is increased, and it is sent to the ozone generator 32. The ozone generator 32 generates a silent discharge in the air, and the ozone gas 4
To generate. For example, ozone gas 4 is 2000 in the air.
It is a gas containing ppm of ozone. The ozone gas supply step S22 is a step of supplying the ozone gas 4 to the higher pressure side of the inside and the outside. The case where the ozone gas 4 is supplied into the container will be described as an example. The ozone gas release valve 35 is closed and the ozone gas injection valve 33 is opened.
The ozone gas 4 enters the container 2 via the ozone gas injection pipe 36. For example, the ozone gas 4 is diluted about 20 times with the air in the container 2, and the ozone gas 5 of about 100 ppm is filled in the container 2. If there is a gap in the wall of the container that causes a leak, the ozone gas 5 leaks through the gap and enters the storage container 20.

Ozone concentration detecting step S30: a step of measuring the ozone concentration on the lower pressure side of the inside and the outside, which has an ozone concentration measuring step S31 and an ozone concentration signal outputting step S32. The case of measuring the ozone concentration inside the storage container (corresponding to the outside of the container) will be described as an example. The ozone concentration measuring step S31 is a step of measuring the ozone concentration in the lower part of the storage container (corresponding to the outside of the container) by the ozone sensor 41. The ozone concentration is measured by the ozone sensor 41 arranged in the lower part of the storage container 10. Since the ozone gas 5 has a larger specific gravity than air, the ozone gas 5 leaking from the gap between the containers 2 drifts downward and collects in the lower part of the storage container 10. Ozone concentration signal output step S
32 is a step of outputting a signal corresponding to the measured ozone concentration. The signal output from the ozone sensor 41 is sent to the leak determination device 50 via the ozone sensor signal line.

Leakage determination step S40: This is a step of determining whether or not there is a leak in the container based on a change in ozone concentration, and has an ozone concentration comparison step S41 and an ozone concentration determination step S42. The ozone concentration comparing step S41 is a step of calculating a difference between the ozone gas concentration and a predetermined ozone concentration. An ozone concentration signal 7 before injecting the ozone gas 4 into the container 2 (hereinafter referred to as a reference signal 8) and an ozone concentration signal 7 after injecting the ozone gas 4 into the container 2 (hereinafter referred to as a measurement signal 8) are compared. . The ozone concentration determination step S42 is a step of determining that there is a leak when the difference is larger than a predetermined value. When the difference between the reference signal 8 and the measurement signal 8 exceeds a predetermined value, it is determined that the container 2 has a leak.

[0031]

EXAMPLE Next, the result of the effect confirmation test when ozone gas is used for the leak inspection will be described. First, the test apparatus will be described. FIG. 3 is a schematic diagram of an apparatus according to an embodiment of the present invention. The test equipment consists of an ozone generator, an ozone tank, a pinhole case, a glass bottle, two ozone sensors, a pressure gauge and a personal computer. After temporarily storing the ozone gas generated by the ozone generator in the ozone tank, the valve B between the ozone tank and the pinhole case is opened. The pinhole case has a hole of a predetermined size artificially formed by a laser beam. The pinhole communicates with the glass bottle, and the glass bottle is provided with one ozone sensor. Another ozone sensor is placed outside to measure the ozone concentration of the environment. Further, an ozone concentration meter communicates with the ozone tank via a valve B. In addition, a pressure gauge communicates with the ozone tank. The pinhole case has 60 microns, 100 microns, 1
The thing with a 50 micron hole was prepared. The personal computer recorded the pressure and ozone concentration in the glass bottle, the ozone concentration in the outer peripheral portion, the output of the pressure gauge and the pressure of the ozone concentration meter.
The measurement range of the ozone sensor is 0 ppb to 250 ppb, and the output is saturated at 250 ppb.

Next, the test method will be described. Install a pinhole case with a predetermined hole to fill the atmosphere in the glass bottle. The valve B is opened and the measurement is started. When the output of the ozone sensor in the glass bottle is saturated, the valve A is opened and the ozone tank pressure and ozone concentration are measured.

The test results will be described. FIG. 4 is a graph (CASE1) of the results of the example of the present invention. FIG. 5 is a graph (CASE2) of the results of the example of the present invention. FIG. 6 is a graph (CASE3) of the results of the example of the present invention. (1) CASE 1: When the pinhole is 60 μm The output of the ozone sensor was saturated in about 230 seconds from the start of the test. At that time, the ozone concentration in the ozone tank is about 400p
It was pm. (2) CASE 2: When the pinhole is 100 μm The output of the ozone sensor was saturated in about 100 seconds from the start of the test. At that time, the ozone concentration in the ozone tank is about 250p
It was pm. (3) CASE 3: When the pinhole is 150 μm The output of the ozone sensor was saturated in about 70 seconds from the start of the test. At that time, the ozone concentration in the ozone tank is about 150p
It was pm. From the test results, the pinhole is 60 to 15
It was found that the leak of ozone gas in the range of 0 micron can be reliably detected in an extremely short time. Further, it can be determined from the correlation between the size of the pinhole and the time when the ozone sensor is saturated that it is possible to detect a leak from a gap having a size of less than 60 microns.

By using the container leak inspection method of the above-described embodiment, it is possible to determine whether or not there is a gap causing a container leak in a short time with high sensitivity by a simple structure. Moreover, since ozone gas is used, an inexpensive ozone sensor having high sensitivity can be used. Further, since ozone gas is generated from the atmosphere, there is no need to prepare a special gas cylinder, which is safe and inexpensive. Further, since the ozone gas which is naturally decomposed into air is used, the post-treatment is easy. In addition, since no liquid is used as in the conventional case, a post-treatment process is not required, no labor is required, and the device is simplified. Further, since the ozone sensor is placed in the lower part of the storage container, ozone gas having a large specific gravity can be detected early.
By using the container leak inspection device of the above-described embodiment, it is possible to provide a device that can perform the container leak inspection method having the above-mentioned excellent features.

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. The containment vessel was decompressed to generate a differential pressure between the inside of the enclosure and the inside of the enclosure (corresponding to the outside of the vessel), but the invention is not limited to this. For example, decompressing the enclosure and the inside of the enclosure A pressure difference may be generated inside the container (corresponding to the outside of the container), or by pressurizing the containment container to generate a pressure difference between the inside of the container and the inside of the container (corresponding to the outside of the container). Alternatively, the container may be pressurized to generate a differential pressure between the inside of the container and the inside of the storage container (corresponding to the outside of the container). When the wall of the container is made of a material that is easily buckled, it is preferable that the pressure inside the container be higher than the pressure outside. Although the storage container is illustrated as if it is a metal container, the storage container is not limited to this, and may be a flexible plastic film container. Also, the container was put in the storage container to separate the inside and the outside of the container, but the present invention is not limited to this. For example, by covering a part of the wall of the container with a bowl-shaped container and partially The outside may be formed. In this case, only a part of the wall of the container covered with the bowl-shaped container is subjected to the leak inspection. Further, although it has been described that the ozone gas is generated by the silent discharge in the atmosphere, the present invention is not limited to this. For example, a known ozone generating method such as a silent discharge in oxygen or ultraviolet irradiation in the atmosphere may be used. .

[0036]

As described above, the container leak inspection method of the present invention has the following effects depending on its configuration.
Ozone gas is added to the inside and outside of the container where the pressure is high, and the presence or absence of a leak in the container is determined by the change in the ozone concentration on the side where the pressure is low. Since the leak detection can be performed well, the leak determination can be performed with high reliability in a short time, and the leak determination can be performed in a dry environment, post-processing becomes easy. Also, since the container is put in the storage container and the gap between the storage containers is on the outside, the storage container corresponds to the outside of the container and the leak judgment of the entire container can be made at one time, and one operation of pressurization or depressurization can be performed. As a result, a pressure difference between the inside and the outside of the container is forcibly generated, so that leak determination can be performed in a short time. Further, since ozone generated from the atmosphere is used, it is not necessary to prepare a special gas, and ozone spontaneously decomposes and returns to air, so that a troublesome post-treatment is unnecessary. Further, since the ozone sensor is installed in the lower portion, ozone having a larger specific gravity than air sinks downward, and the ozone sensor in the lower portion measures the ozone concentration of the ozone gas, so that the leak determination can be performed quickly. Further, since the presence or absence of the leak is determined by the change in the ozone concentration, it is possible to easily determine the leak of the ozone gas only by observing the increase in the ozone concentration. In addition, the present inspection method is adopted for a container for enclosing a liquid, and since the lower limit value of the gap dimension where ozone gas leaks is close to the lower limit value of the gap dimension that does not substantially leak the liquid, the leak judgment of the container enclosing the liquid is performed. It can be done effectively. Further, as described above, the container leak inspection device of the present invention has the following effects due to its configuration. Ozone gas is injected into the container placed in the containment vessel, and the presence or absence of a leak is determined by the change in the ozone concentration in the containment vessel. Therefore, highly active ozone can be used to detect a small amount of leak with high sensitivity, and reliability can be achieved in a short time It is possible to perform high-performance leak determination and to perform leak determination in a dry environment, so post-processing becomes easy. Therefore, it is possible to provide a leak inspection method and a leak inspection device for a highly reliable container that can surely find a leak from a gap that is difficult to visually confirm.

[0037]

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a procedure diagram of the embodiment of the present invention.

FIG. 3 is a schematic diagram of an apparatus according to an embodiment of the present invention.

FIG. 4 is a graph (CASE1) of the results of the example of the present invention.
Is.

FIG. 5 is a graph (CASE2) of the results of the example of the present invention.
Is.

FIG. 6 is a graph (CASE3) of the results of the example of the present invention.
Is.

[Explanation of symbols]

1 Container leak inspection device 2 containers 3 atmosphere 4 Ozone gas 5 Gas in the container (ozone gas) 6 Containment vessel gas (ozone gas) 7 Ozone concentration signal 8 Reference signal, measurement signal 10 Storage container 11 Storage container body 12 Storage container lid 13 Storage container lid sealing member 20 Pressurizing / depressurizing equipment (pressure reducing equipment in the figure) 21 Yuben 22 Pressurizing / depressurizing pump (vacuum pump in the figure) 23 Open valve 30 Ozone gas supply equipment 31 air pump 32 Ozone generator 33 Ozone gas injection valve 34 Ozone gas pressure gauge 35 Ozone gas release valve 36 Ozone gas injection pipe 40 Ozone concentration detector 41 Ozone sensor 42 Ozone sensor signal line 50 Leakage determination equipment 51 Ozone concentration comparator 52 Ozone concentration determiner S10 Differential pressure generation process S11 Container storage process S12 container adjustment process S20 Ozone gas addition process S21 ozone gas generation process S22 Ozone gas supply process S30 Ozone concentration detection process S31 Ozone concentration measurement process S32 Ozone concentration signal output process S40 Leakage determination process S41 Ozone concentration comparison process S42 Ozone concentration determination process

Claims (7)

[Claims] 1. A container leak inspection method, comprising: a differential pressure generating step of generating a differential pressure between the inside and the outside of the container; and ozone gas addition for adding ozone gas to the higher pressure side of the inside and the outside. And an ozone concentration detection step of measuring the ozone concentration of the lower pressure side of the inside and the outside, and a leak determination step of determining the presence or absence of a leak in the container based on the change in the ozone concentration. Leak inspection method for containers. 2. The differential pressure generating step includes a container storing step of putting a container in a storage container and a container pressurizing / depressurizing step of performing one of pressurization and depressurization on one of the container and the storage container. The leak inspection method for a container according to claim 1. 3. The ozone gas adding step includes an ozone gas generating step of generating ozone gas from the atmosphere, and an ozone gas supplying step of supplying the ozone gas to the higher pressure side of the inside and the outside. The leak inspection method for a container according to claim 1 or claim 2. 4. The ozone concentration detecting step includes an ozone concentration measuring step of measuring an inner or outer lower ozone concentration by an ozone sensor, and an ozone concentration signal outputting step of outputting a signal corresponding to the measured ozone concentration. The leak inspection method for a container according to any one of claims 1 to 3, 5. An ozone concentration comparing step of calculating a concentration difference between the ozone concentration and a predetermined ozone concentration, and an ozone concentration determining step of determining that there is a leak when the concentration difference is larger than a predetermined value. The container leak inspection method according to any one of claims 1 to 4, further comprising: 6. The leak inspection method for a container according to claim 1, wherein the container is a container for enclosing a liquid. 7. A container leak inspection apparatus, comprising: a storage container for storing the container in a sealed state, and a pressurizing / depressurizing device that communicates with the container or one of the storage container and performs one of pressurization and depressurization operation. And an ozone gas supply device for supplying ozone gas to the container or the containment container having a higher internal pressure, and an ozone concentration detection device for measuring the ozone concentration on the side of the container or the containment container having a lower internal pressure, Leak inspection device for container, characterized in that if the ozone concentration exceeds a predetermined value, it is determined that there is a leak in the container