JP2004028974A - Tape for simple ammonia leak test and leak testing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tape for test and a testing method for performing ammonia leak test on an arbitrary container, and to provide a tape for simple ammonia leak test and a leak testing method for performing a convenient and accurate leak test with a low gas pressure by using a simple and thin tape. <P>SOLUTION: After a container 5 for a specimen is surface-treated with an ammonia detecting agent, tapes 1 and 1a with pores 2 formed therein are affixed to the container 5 at a position near a place requiring a leak test. When a proper quantity of ammonia water is injected into the container 5, the pressure of gaseous ammonia generated in the container 5 swells out the tapes 1 and 1a, and a leak of the gas allows the pores 2 to be ascertained. This potentiates accurate ammonia leak test. Gaseous ammonia, and the like, are removed by injecting thereinto an ammonia absorbent. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a leak test tape for a container for enclosing ammonia and a leak test method using the tape, and particularly to a simple test which requires a low test pressure, high detection accuracy, and does not require special large-sized equipment and equipment. The present invention relates to an ammonia leak test tape and a leak test method.
[0002]
[Prior art]
As a leak test of a storage tank for enclosing and storing liquefied natural gas or the like, an ammonia leak test method with a lower test pressure and higher detection accuracy than in the past has been adopted. As a conventional test method, a large-scale test method using a large apparatus such as a large gas cylinder, a pressure reducing valve, a gas-filled connecting hose, and a pressure gauge has been used.
[0003]
[Problems to be solved by the invention]
In the case of the above-mentioned conventional leak test method, a large-sized device or equipment is required as described above, and there is a problem that a leak test cannot be easily performed. There is a problem that it is necessary to completely shut off, and it is difficult to apply to a leak test of a container in which sealing of ammonia gas is difficult or a container in a semi-finished product state.
[0004]
The present invention has been invented to solve the above problems, and has a low test pressure and a long standing time, so that a high detection accuracy comparable to that of the helium test can be obtained and a leak pattern can be indicated. It is an object of the present invention to provide a simple ammonia leak test tape and a leak test method that can be simply specified, can be easily implemented, and can be sufficiently applied to containers in which ammonia gas is difficult to seal or semi-finished products. I do.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a simple ammonia leak test tape according to claim 1, wherein the tape is attached to a container to observe a leak state of ammonia gas put in the container, and the leakage point of the container is checked. The tape is made of a thin material that does not allow ammonia gas to permeate, and one or more micro holes are formed at predetermined positions by laser processing. Since the test pressure is low, the tape having the above structure is attached to the container of the subject, ammonia water is injected into the container, and the leak state of the container is detected based on the confirmation of the micropores of the tape. Can be. Therefore, the leak test can be performed very easily and without using a special device or the like.
[0006]
The tape for a simple ammonia leak test according to a second aspect of the present invention is characterized in that the tape is made of aluminum foil. Aluminum foil commonly used as a tape is used, and can be easily and inexpensively obtained.
[0007]
Further, the tape for a simple ammonia leak test according to a third aspect of the present invention is characterized in that the diameter of the micropores of the tape does not exceed at least 20 μm. Since the fine holes require small holes of about 20 μm and require high-precision processing, processing by laser processing is optimal.
[0008]
Further, in the simple ammonia leak test tape according to claim 4 of the present invention, when the fine holes of the tape are tentatively referred to as a first hole, a second hole,... A mark having a mark for parallax in a direction from the first hole to the n-th hole is provided at a left corner of the tape surface on the first hole side. Thereby, the position where the surface of the tape and the first hole are opened can be known, and the tape can be correctly set on the test object.
[0009]
Further, in the simple ammonia leak test method according to claim 4 of the present invention, a tape made of a thin material that is impermeable to ammonia gas and having a single or a plurality of fine holes at predetermined positions is attached to a container of a subject. An ammonia leak test method for observing a leak state of ammonia gas in the container, wherein the test method includes a first surface treatment for removing oils, fats, moisture, alkalis, and the like attached to the container. A procedure, a second procedure for drying the container, a third procedure for applying the tape to a location requiring a leak test, and a fourth procedure for applying an ammonia detecting agent to a location requiring a leak test. A fifth procedure for injecting an appropriate amount of aqueous ammonia corresponding to the volume of the container, a sixth procedure for leaving the container for several hours in this state, a seventh procedure for confirming the micropores in the tape, and observing a leak location Eighth procedure A ninth procedure of enclosing an ammonia gas absorbent for absorbing ammonia gas in the container, a tenth procedure of leaving the container in this state for several hours, and an eleventh procedure of releasing the ammonia gas absorbent. A twelfth procedure for removing the tape and a thirteenth procedure for removing the ammonia detector applied to the container are sequentially performed. As described above, the leak point of the container is detected with high accuracy by a simple method. Because of the low test pressure, it can be applied to any container leak test.
[0010]
In addition, in the simple ammonia leak test method according to claim 5 of the present invention, the tape is attached by first attaching a tape having a single fine hole to the container, and then having a plurality of fine holes on an upper surface thereof. It is characterized in that tapes are stacked and adhered. The gas leak first leaks outward from a single micro-perforated tape, and this leak gas leaks outside through a multi-porous tape. As described above, it is possible to reliably detect gas leakage by confirming leakage from a tape having a plurality of fine holes. Thereby, the detection accuracy can be improved.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the simple ammonia leak test tape and the leak test method of the present invention will be described in detail with reference to the drawings. First, the shape of the tape used in the simple ammonia leak test of the present invention will be described with reference to FIGS. The tape may be any material that does not allow the passage of ammonia gas and that is thin enough to be easily adhered to an arbitrary location of the container of the subject. In this embodiment, a commercially available aluminum foil adhesive tape used for water sealing of a household sink which can be easily obtained anywhere is adopted. As shown in FIG. 1, the tape 1 is, for example, a rectangular thin material having an A size of 70 mm, a B size of about 30 mm, and a thickness t of 0.1 mm, and an aluminum foil as described above. Of course, a metal piece such as a stainless steel material may be used instead of the aluminum foil. A single fine hole 2 is formed at a predetermined position of the tape 1 so as to penetrate therethrough. It is desirable that the center lines 3 and 4 be provided in the fine holes 2 so that the positions thereof can be clearly understood. It has been found experimentally that the pores 2 having a diameter of about 20 μm (± 10 μm) are preferable. Laser processing is most desirable for processing the fine holes 2 of about 20 μm with high precision.
[0012]
The tape 1a shown in FIG. 2 has a plurality of fine holes 2 (three in the drawing), and the other shapes are the same as those shown in FIG. Each of the micro holes 2 is formed at the intersection of the center lines 3 and 4 by laser processing so that its position can be understood.
[0013]
FIG. 3 shows the tape 1, 1a shown in FIGS. 1 and 2 adhered to the container 5 of the subject. The sticking place may be an arbitrary place, but is preferably in the vicinity of a place considered to be a leaking place. As shown in FIGS. 3 and 4, the tape 1 is first stuck to a portion of the container 5 where a gas leak is likely to occur (a location requiring detection). After the tape 1 is attached, the tape 1a is attached on the upper surface. Next, the peripheral edges of the tapes 1 and 1a are coated with a resin material 6 as shown in the drawing. Thereby, leakage from the peripheral edges of the tapes 1 and 1a is completely prevented.
[0014]
FIG. 5 schematically shows a state of gas leakage from the container 5 to which the tape is attached as shown in FIG. The gas leaking from the gas leaking part of the container 5 leaks from the fine hole 2 of the tape 1 having the single fine hole 2. This leak gas passes through the gap between the tape 1 and the tape 1a and leaks outside through the plurality of fine holes 2 of the tape 1a. If there is a gas leak, the area around the fine holes 2 is discolored. Therefore, gas leaks from the fine holes 2 of the tape 1a can be visually confirmed, and the leak state of the container 5 can be detected. Note that a gap is formed between the tape 1 and the tape 1a or between the container 5 and the tape 1 because the tapes 1 and 1a swell due to the vaporization pressure after the ammonia gas is sealed.
[0015]
Next, the specific contents (procedure) of the simple ammonia leak test method of the present invention will be described with reference to the flowchart of FIG. In this test, ammonia water is used. Since the relationship between the amount of ammonia water and the pressure and concentration of ammonia gas is clear, the amount of ammonia water injected into the container 5 of the subject is It is easy to predetermine the amount required to generate the low pressure ammonia gas required for the test. In addition, an ammonia gas absorbent is used to remove the injected ammonia water (which changes into ammonia gas) from the inside of the container 5 after the test. In the present embodiment, zeolite is used, but is not limited to this. is not.
[0016]
First, the surface treatment of the container 5 is performed as a first procedure (Step 100). An accurate leak test cannot be performed if fats, oils, moisture, alkalis, etc. adhere to the surface of the container 5. Therefore, first, a surface treatment for removing these deposits is performed. The surface treatment may be performed by any procedure, but sand blast and shot blast are preferred. As a surface treatment, if the surface has moisture or the like, pseudo-coloring is likely to occur, so that the container 5 is dried as a second procedure to remove the moisture or the like (step 101).
[0017]
Next, as shown in FIG. 3, the tapes 1 and 1a are attached as a third procedure at an arbitrary position of the container 5 (step 102). Since the test pressure is as low as 0.01 to 0.02 Mpa (0.01 to 0.02 kg / cm 2), the tapes 1 and 1 a having the above structure are sufficiently sealed. As described above, the tape is applied by superposing the tape 1 and the tape 1a. Further, the peripheral edge is completely sealed by the resin material 6.
[0018]
Next, as a fourth procedure, an ammonia detector is uniformly applied to the surface of the container 5 that requires a leak test (step 103). It is checked whether or not the ammonia detector applied before the injection of the ammonia into the container 5 changes color (step 104). In the case of discoloration (in the case of yes), the process returns to the surface treatment in step 100 because oils, fats, water and alkali exist on the surface of the container 5. If the color does not change (in the case of no), the process proceeds to the next step.
[0019]
Next, as a fifth procedure, ammonia water is injected into the container 5 (step 105). The injection amount is determined prior to the injection of the ammonia water. As described above, the air volume of the container 5 is obtained by calculation, and by determining the gas partial pressure and the concentration of the ammonia gas, the injection amount of the aqueous ammonia can be easily obtained from a relation diagram, a relation expression, or the like. In addition, when the air volume of the container 5 is 400 liters or less, it is possible to inject ammonia water with a syringe, which is extremely simple. This also allows for efficient injection.
[0020]
When the ammonia water is injected into the container 5, ammonia gas is generated in the container 5, and the tapes 1 and 1a attached to the outer surface of the container 5 expand due to the vaporization pressure. Here, as a sixth procedure, the apparatus is left for several hours (about 1 to 2 hours) (step 106).
[0021]
Next, as a seventh procedure, it is observed whether or not the micropores 2 of the tapes 1 and 1a have expanded due to the vaporization pressure of the tape 1 (step 107). If no, the process returns to step 106 and is left unattended. In the case of yes, if there is a gas leak, the micro holes 2 can be visually observed and the test detection accuracy is judged to be sufficient. Then, the process proceeds to the eighth step of observing and confirming the presence or absence of leak (step 108). The detection of the leak point of the container 5 can be accurately and easily performed by the steps 100 to 108 from the first procedure to the eighth procedure.
[0022]
As described above, even if the leak test of the container 5 is temporarily completed, the inside of the container 5 is in a state of being filled with ammonia gas. For this reason, it is necessary to remove the ammonia gas in the container 5, and an ammonia gas absorbent is injected as a ninth procedure (step 109). As the ammonia gas absorbent, for example, spherical zeolite is used. This ammonia gas absorbent is determined in consideration of the gas concentration, the air volume of the container 5, and the like. In the present embodiment, for example, the gas concentration is 2%, and 8 g is sealed per liter of air volume.
[0023]
After the ammonia gas absorbent (zeolite) has been sealed, it is left in this state as the next tenth procedure (step 110). The leaving time is, for example, 2 hours to 3 hours.
[0024]
Next, as an eleventh procedure, the ammonia absorbent adsorbing the enclosed ammonia gas is released from the container 5 (step 111). Next, as a twelfth procedure, the tapes 1 and 1a are removed from the container 5 (step 112), and finally, as a thirteenth procedure, the ammonia detector applied to the surface of the container 5 is removed (step 113). The removed ammonia absorbent, ammonia detector, etc. are collected and disposed of by a safe method.
[0025]
As described above, the ammonia leak test of the present invention is a relatively simple method in which the tape 1, 1a is attached to the container 5, an ammonia detecting agent is applied, the ammonia water is injected, and the leak condition is observed. It is performed easily and in any place because no special device is required. The thin tapes 1 and 1a are applied to an arbitrary container because the ammonia gas has a low pressure. It is necessary to form the fine holes 2 of the tapes 1 and 1a with high accuracy as one of the means for improving the test accuracy. However, by using laser processing, accurate holes can be formed. In the above description, the size of the fine holes 2 is about 20 μm. However, the smaller the fine holes 2, the better, and preferably about 10 μm.
[0026]
7 and 8 show the marks 7 provided on the tapes 1 and 1a described above. The mark 7 indicates the surface of the tape 1, 1a and the position of the first hole (the hole on the left side of the surface), and is provided at the left corner of the surface of the tape 1, 1a. In the present embodiment, the hook mark is shown, but not limited to this, as long as the direction can be recognized. By providing the mark 7, the tapes 1 and 1a can be correctly set on the test object.
[0027]
【The invention's effect】
According to the present invention, commercially available ammonia water (25%) can be used, and the leak test can be performed relatively inexpensively and easily. In addition, the test pressure is low, and a sufficient sealing can be achieved with a commercially available tape such as an aluminum foil tape, so that an accurate leak test can be performed. In addition, comprehensive control such as test pressure gas concentration and standing time can be easily performed, and an accurate leak test can be performed.
[Brief description of the drawings]
FIG. 1 is a plan view showing a tape having a single fine hole used in a leak test of the present invention.
FIG. 2 is a plan view showing a tape having a plurality of micro holes formed therein for use in a leak test according to the present invention.
FIG. 3 is a schematic perspective view showing a state where a tape is attached to a container of a subject.
FIG. 4 is a schematic perspective view showing a state where a tape is attached to a container of a subject.
FIG. 5 is a schematic view showing a gas leak state when the tape of the present invention is used.
FIG. 6 is a flowchart for explaining the procedure of the simple ammonia leak test method of the present invention.
FIG. 7 is a plan view showing the tape in the case where the number of micro holes provided with marks is one;
FIG. 8 is a plan view showing a tape in a case of a plurality of micro holes provided with marks.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tape 1a Tape 2 Micro hole 3 Center line 4 Center line 5 Container 6 Resin material 7 Mark

Claims (6)

A tape for detecting a leak portion of the container by observing a leak state of the ammonia gas stuck to the container and put in the container, wherein the tape is made of a thin material through which the ammonia gas does not pass. A simple ammonia leak test tape characterized in that one or more microholes are formed at positions in a laser beam. The simple ammonia leak test tape according to claim 1, wherein the tape is made of aluminum foil. The simple ammonia leak test tape according to claim 1 or 2, wherein the diameter of the micropores of the tape does not exceed at least 20 µm. When the fine holes of the tape are tentatively referred to as a first hole, a second hole,..., An n-th hole from the left of the tape surface, the first hole is provided at a left corner of the tape surface on the first hole side. The simple ammonia leak test tape according to any one of claims 1 to 3, further comprising a mark having a mark for parallax in a direction from a direction toward the n-th hole. An ammonia leak test in which a tape made of a thin material that is impermeable to ammonia gas and having one or a plurality of fine holes at predetermined positions is attached to a container of a subject, and a leak state of the ammonia gas in the container is observed. The test method comprises: a first procedure for performing a surface treatment for removing oils, fats, moisture, alkalis, etc. attached to the container, a second procedure for drying the container, and the tape. A third procedure of applying an ammonia detecting agent to a place requiring a leak test, a fifth procedure of applying an appropriate amount of aqueous ammonia corresponding to the volume of the container, A procedure, a sixth procedure for leaving the tape for several hours in this state, a seventh procedure for confirming micropores in the tape, an eighth procedure for observing a leak, and absorption of ammonia gas in the container. Ammonia gas A ninth procedure for enclosing the absorbent, a tenth procedure for leaving the apparatus for several hours in this state, an eleventh procedure for releasing the ammonia gas absorbent, and a twelfth procedure for removing the tape, A simple ammonia leak test method, comprising sequentially performing a thirteenth procedure for removing an ammonia detector applied to the container. The simple ammonia leak test is characterized in that the tape is firstly adhered to the container with a tape having a single fine hole, and then a tape having a plurality of fine holes is stacked on the upper surface of the tape. Method.

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