JP4248469B2 - Inspection gas generator - Google Patents

Description

  The present invention relates to an inspection gas generator used for inspection of a gas detection device and the like.

Patent Document 1 discloses that a voltage is applied to a proton conductor to electrolyze water in the conductor to generate inspection gas. However, the structure of the inspection gas generator of Patent Document 1 is based on the premise that it is integrated with the gas sensor, and is not a separate inspection gas generator from the gas sensor.
JP 2004-61171 A

A basic object of the present invention is to provide a reliable inspection gas generator with a simple structure.
A secondary problem of the present invention is to provide an inspection gas generator that can repeatedly generate inspection gas without liquid leakage from the inspection gas generator.
Another object of the present invention is to prevent a short circuit between a conductive member serving as an inspection gas generating electrode and a metal housing or a metal sealing body .

In the inspection gas generator of the present invention, the metal sealing body is attached to the metal housing via an insulator so as to close the opening of the metal housing , and a voltage is applied between the metal housing and the metal sealing body. The inspection gas is generated from the inspection gas generating means accommodated in the metal housing , and an outlet for the gas generated in the metal housing is provided in the metal sealing body or the metal housing .

The gas outlet may be a gas-permeable and non-liquid-permeable membrane, but if the valve body is opened by increasing the internal pressure of the metal housing , liquid leakage can be easily prevented, and a two-layer metal plate is particularly preferred. Set the valve body inside the metal sealing body made of

  Preferably, an inspection gas is generated by electrolyzing water by using a gelled electrolyte solution as the inspection gas generation means, and liquid leakage is prevented by preventing fluidity at a normal temperature.

Preferably, the inspection gas generation means contacts a conductive member having a high specific surface area made of foam metal, a bundle of metal fibers, or a bundle of carbon fibers attached to a metal sealing body or a metal housing with the electrolyte. The inspection gas is generated by electrolysis of the electrolyte. The solvent of the electrolytic solution is preferably water, but may be a mixed solvent such as water-ethanol.

Preferably, even if the volume of the electrolytic solution is less than half of the volume between the metal sealing body and the metal housing, and the inspection gas generator is laid down, the electrolytic solution blocks the gas outlet. Do not.

Preferably, the inner surface of the metal housing or the metal sealing body on which the conductive member is not attached is covered with a liquid-permeable separator to prevent contact between the conductive member and the inner surface.

In this invention, the metal housing and the metal sealing body are connected via the inspection gas generating means, the inspection gas is generated by applying a voltage between the metal sealing body and the metal housing, and is discharged from the gas outlet. To do. For example, when water is electrolyzed, hydrogen can be generated at a voltage of about 1.3 V to 5 V, preferably about 3 to 4.5 V. If the gas outlet is composed of a valve body using an elastic body such as rubber or a spring, or if a porous PTFE (polytetrafluoroethylene) sheet or the like is used as the gas outlet, there is no liquid leakage and CO is generated. Only the inspection gas can be released to the outside without spilling the oxalic acid compound used in the process.

When using a valve body, the reliability against liquid leakage is particularly high, and the metal sealing body usually has two layers of metal plates, leaving a space between them. Then, it is simple in structure. In the generation of the inspection gas, when an inspection gas such as hydrogen is generated by electrolyzing an aqueous electrolytic solution, the inspection gas can be generated many times repeatedly with a small amount of the electrolytic solution. In order to prevent leakage of the electrolytic solution, it is preferable to gel the electrolytic solution.

In electrolysis of an electrolytic solution, when a conductive member having a high specific surface area such as foam metal, metal fiber or carbon fiber aggregate is used as an electrode, inspection gas can be efficiently generated.
Furthermore, if the amount of the electrolyte is less than half of the space between the metal housing and the metal sealing body , the electrolyte will block the gas outlet and the electrolyte will leak due to the internal pressure when the inspection gas is generated. Can be prevented.
It is not preferable that the conductive member deforms and comes into contact with the other side of the metal housing or metal sealing body (the member on which the conductive member is not attached). Therefore, if the inner surface of the other side is covered with a liquid separator, a short circuit can be prevented.

  In the following, an optimum embodiment for carrying out the present invention will be shown.

  1 to 7 show an embodiment and its modifications. In these drawings, the members having the same reference numerals and the same names represent the same members, and the description relating to the embodiment in FIGS. 1 to 3 applies to the modified examples in FIGS.

In FIG. 1, 2 is an inspection gas generator, 4 is a metal housing such as stainless steel, and contains gelled water 6 in which an electrolytic solution such as KOH, KHCO ₃ , K ₂ CO ₃ or the like is gelled. The type of gelling agent and the type of electrolyte are arbitrary, but alkali metal hydroxides, alkali metal carbonates, alkali metal hydrogen carbonates, etc. are toxic gases such as chlorine, NO ₂ and SO ₂ during electrolysis. Since it does not generate | occur | produce, it is preferable. The inner surface of the metal housing 4 is covered with a porous and insulating liquid-permeable separator (for example, a polypropylene sheet) 8, 10 is a sealing body, and is formed of two layers of stainless steel, etc. The valve element 14 is accommodated in the container. A gasket 12 is an insulating member. The valve body 14 is made of an alkali-resistant rubber such as EPDM (ethylene propylene rubber), and may be a rubber such as SBR (styrene butadiene rubber).

  The sealing body 10 is provided with an inner opening 16 and an outer opening 18 so that the inner opening 16 is covered with the valve body 14. Further, the internal volume between the housing 4 and the sealing body 10 is about 6 cc, less than ½ of that, preferably 40% or less. Here, 2 cc of gelled water 6 is accommodated. Reference numeral 20 denotes a foam metal such as nickel, which may be a bundle of metal fiber fibers or carbon fibers, and is a porous conductive member. A gas such as hydrogen generated at the contact portion with the gelled water 6 flows along the inside thereof. A member that can move and get out of the gelled water 6 is preferable. When a voltage is applied using the metal housing 4 as an anode and the sealing body 10 as a cathode, hydrogen is generated in the portion of the foam metal 20 and escapes to the upper part of the gelled water 6 through the foam metal. As shown, the valve body 14 is pushed up and released to the outside.

  The inspection gas generator 2 is stored or used in an upward or sideways manner. By setting the volume of the gelled water 6 to less than ½ of the volume between the sealing body 10 and the housing 4, more preferably 40% or less, even if the gelled water is fluidized at, for example, 60 ° C. The gelled water can be prevented from leaking from the opening 16. At room temperature or the like, the gelled water 6 does not have fluidity, and liquid leakage from the opening 16 does not occur. Here, the metal foam 20 is welded to the bottom surface side of the sealing body 10, but it may be attached to the inner surface of the MEAt housing 4. Further, even when the foam metal 20 is deformed for some reason, the metal housing 4 is not short-circuited because of the separator 8. Since the separator 8 is porous and liquid-permeable, it does not hinder the electrolytic current from the metal housing 4 to the foam metal 20. Furthermore, even if the gelled water 6 touches the valve body 14, as long as the internal pressure is not applied, the opening 16 is blocked by the valve body 14, so that liquid leakage hardly occurs.

  In the sealing body 11 of FIG. 2, the valve body 15 is pressed against the opening 16 by the spring 15 a to prevent liquid leakage from the opening 16. The other points are the same as the inspection gas generator 2 of FIG.

  FIG. 3 shows an example of an inspection device 30 using the inspection gas generator 2, and a battery 32 of 3V to 4.5V or the like is connected to the inspection gas generator 2 via a switch 34. At this time, the metal housing side is + and the sealing body side is-. Reference numeral 36 denotes a case, and 38 denotes a cover, which is provided with a nozzle 40 or the like on the sealing body side so that inspection gas such as hydrogen can be introduced into a gas detection device or a gas leak alarm.

  FIG. 4 shows an example in which the proton conductor gas sensor is inspected using the inspection device 30 of FIG. 3, and the outputs of the gas sensors for the three inspection devices are displayed in an overlapping manner. Here, the output of the gas sensor is a waveform when 6V is full scale and hydrogen is generated by applying a voltage of 4V to the inspection device 30 for 10 seconds.

  5 to 7 show modified examples of the inspection gas generator. In the inspection gas generator 52 of FIG. 5, a separator 54 holding a KOH aqueous solution is used, and an electric current is passed between the sealing body 10 and the metal housing 4, whereby water is electrolyzed by the separator 54 to generate hydrogen or the like. Generate inspection gas. The separator may be provided with or without an electrode, or a proton conductor may be used in place of the separator. Since the separator 54 has a small amount of water that can be retained, for example, when a deliquescent electrolyte having a wide potential window such as KF is used, moisture can be replenished from the air.

  In the inspection gas generator 62 of FIG. 6, a heater 64 is disposed between the sealing body 10 and the metal housing 4, and the heater 64 is heated by a voltage between them, thereby oxalic acid, its compound, etc. The gas source 66 is decomposed to generate inspection gas such as CO.

  The medium such as the electrolytic solution held in the gelled water 6 or the separator 54 is not limited to water, and a mixed solvent such as water / ethanol may be used, for example. Further, in the gas source 66 of FIG. 6, ethanol gas may be generated using ethanol, gelled ethanol, or the like instead of the oxalic acid compound.

In the embodiment, the foam metal 20 is attached to the sealing body 10 side, but this arrangement may be reversed to attach the foam metal to the metal housing side. Such an example is shown in FIG. The inspection gas generator 72 has no opening in the sealing body 74, and the foam metal 21 is attached to the metal housing 73 side by welding, for example, so as to be immersed in the gelled water 6. The metal housing 73 side is used as the upper side and the sealing body 74 side is used as the lower side. A large number of openings 75 are provided and covered from the inner surface side of the metal housing 73 with a gas permeable film 76 such as PTFE to prevent liquid leakage. To do. In this example, the separator 8 is not provided.

Cross section of inspection gas generator of the embodiment Sectional drawing which shows the modification of a sealing body Sectional drawing which shows the Example of an inspection apparatus Waveform diagram when the gas detector is inspected by the inspection device of FIG. Cross section of inspection gas generator using liquid film Cross section of inspection gas generator using heater Cross-sectional view of a modified inspection gas generator

Explanation of symbols

2, 52, 62 Inspection gas generator 4 Metal housing 6 Gelled water 8 Separator 10, 11 Sealing body 12 Gasket 14, 15 Valve body 16, 18 Opening 20, 21 Metal foam 30 Inspection device 32 Battery 34 Switch 36 Case 38 Cover 40 Nozzle 54 Separator 64 Heater 66 Gas source 72 Inspection gas generator 73 Metal housing 74 Sealing body 75 Opening 76 Gas permeable membrane

Claims (6)

Inspection gas stored in the metal housing by attaching a metal sealing body to the metal housing via an insulator so as to close the opening of the metal housing and applying a voltage between the metal housing and the metal sealing body. Generate inspection gas from the generation means ,
Furthermore, an inspection gas generator in which a gas sealing body or a metal housing is provided with an outlet for gas generated in the metal housing . The inspection gas generator according to claim 1, wherein the gas outlet is a valve body that opens when the internal pressure of the metal housing increases. The inspection gas generator according to claim 1 or 2, wherein the inspection gas generation means includes at least a gelled electrolyte. The inspection gas generating means is made by contacting a conductive member having a high specific surface area made of foam metal, a bundle of metal fibers, or a bundle of carbon fibers attached to a metal sealing body or a metal housing with an electrolytic solution. The inspection gas generator according to claim 1, wherein inspection gas is generated by electrolysis of liquid. The inspection gas generation means generates an inspection gas by electrolysis of an electrolytic solution, and the volume of the electrolytic solution is less than ½ of the volume between the metal sealing body and the metal housing. Inspection gas generator in any one of 1-4. In the metal housing or the metal sealing body , the inner surface on the side where the conductive member is not attached is covered with a liquid-permeable separator to prevent contact between the conductive member and the inner surface. The inspection gas generator according to any one of claims 3 to 5.

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