JP2003103134A - Gaseous sf 6 sampling device and method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gaseous SF 6 sampling device and its method which exhibit an excellent environmentally friendly characteristic by sampling a slight amount of gaseous SF 6 intruding into gaseous nitrogen and the atmosphere and suppressing the amount of emission of the gaseous SF 6 in the atmosphere. SOLUTION: A gas storage tank 1 for storing a gaseous mixture containing a light amount of the gaseous SF 6 in the gaseous nitrogen or air is arranged. A sampling column 5 for taking in the gaseous mixture is connected to this gas storage tank 1. An adsorbent 4 for selectively adsorbing the gaseous SF 6 is packed in the sampling column 5. The adsorbent 4 is composed of synthetic zeolite having a pore diameter greater than the molecular diameter of the gaseous SF 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to S for collecting nitrogen gas or SF6 gas existing in a small amount or in a small amount in air.
The present invention relates to F6 gas collection technology.

[0002]

2. Description of the Related Art In general, substations are equipped with devices such as circuit breakers and disconnectors for use in system switching and maintenance inspection. Among these devices, particularly large ones are filled with SF6 gas as an insulating gas, and are collectively called a gas insulated switchgear (GIS). SF6 gas is widely used in these devices because it is excellent in insulating performance and arc extinguishing performance and is chemically stable and harmless.

However, SF6 gas has the properties that it has a high greenhouse effect and a long life until decomposition. Therefore,
From the viewpoint of global environment protection, it was designated as an emission control target at the 1997 Conference on Prevention of Global Warming (COP3). From now on, considering the long-term global environment, SF
It is required to reduce the emission of 6 gases to the maximum.

SF6 In order to reduce gas emission, SF6
It is effective to reduce the amount of gas used,
Various measures have been taken, such as miniaturization of GIS and conversion of SF6 gas to other gas. Above all, the method of using a mixed gas to which a small amount of SF6 gas is added as an insulating gas can drastically reduce the amount of SF6 gas used, and has been attracting attention. One of the most viable ones is SF with nitrogen gas as the base material.
It is considered to add a small amount of 6 gas.

By the way, in the case of an internal inspection of a gas insulated switchgear or an accident, it is common to collect and store the insulating gas sealed in the equipment in a gas storage tank and return it from the tank to the equipment for reuse after the work is completed. Is. At this time, if the insulating gas is composed of only SF6 gas, pressurized liquefaction can be easily performed by using a pressurizing device, so that the storage capacity is small and the gas can be recovered by a compact device.

However, when a mixed gas obtained by adding a small amount of SF6 gas to nitrogen gas is recovered, nitrogen gas and SF6 gas cannot be liquefied at the same time. For this reason,
The mixed gas was stored in the gas phase, and a large gas storage tank was required. In recent years, when power demand has increased,
The gas insulated switchgear is often installed in a limited space such as a basement, and there is a strong demand for downsizing not only the equipment itself but also the equipment for performing maintenance. Therefore, the inventors are currently focusing on the development of such a mixed gas recovery apparatus, and have already filed several patent applications including the basic patent (Japanese Patent Application No. 10-232640 and Wishhei 11-078588
Issue).

Here, an outline of a conventional mixed gas recovery apparatus 20 will be described with reference to FIG. A mixed gas in which a small amount of SF6 gas is added to nitrogen gas is enclosed in the mixed gas insulating device 21, and a filter 22, an introduction buffer tank 23, a gas separation device 24, and a pressure liquefaction device 25 are connected to a pipe 26.
Are sequentially connected by. A valve 27 is provided on the pipe 26.
And the pump 28 is appropriately arranged.

The gas separation device 24 is a device to which the pressure swing adsorption (PSA) technology is applied based on the special molecular sieve effect of the adsorbent as a basic principle. By selectively adsorbing only SF6 gas, nitrogen gas and SF6 gas are separated. Are separated.
Then, the nitrogen gas separated by the gas separation device 24 is sent to the outlet 30, and the SF6 gas is sent to the pressurized liquefaction device 25.

On the other hand, the pressure liquefaction device 25 is wound with a cooling pipe 30 to which the refrigerant is sent from the refrigerator 29, and SF
The 6 gases are cooled, converted into a liquid phase, and sent to the SF6 liquid tank 31. Further, the pressurized liquefaction device 25 and the introduction part buffer tank 23 are connected by a reflux pipe 32, and SF6 which has not been liquefied by the pressurized liquefaction device 25.
The gas is returned to the introduction portion buffer tank 23. Reference numeral 33 is a control panel for controlling the area surrounded by the two-dot chain line.

[0010]

By the way, in the gas separation device 24 of the above-mentioned mixed gas recovery device 20, S is removed from the mixed gas.
It is difficult to completely separate F6 gas.
For this reason, the exhaust gas sent to the exhaust port 30 was nitrogen gas mixed with about 6% of SF6 gas, and SF6 gas was slightly released to the atmosphere. In order to realize long-term conservation of the global environment, it is required to completely recover SF6 gas in the mixed gas having such a small mixing ratio.

The SF enclosed in the gas-insulated switchgear
When recovering 6 gases, it is not necessary to use the mixed gas recovery device 20 as described above, but it is essential to draw and recover SF6 gas with a vacuum pump until a high vacuum state is reached. However, when the pressure of the gas on the device side becomes low due to the progress of gas recovery, the internal pressure and the exhaust performance of the pump reach a balance. At this time, the exhaust efficiency deteriorated and the collection time was prolonged (see the graph in FIG. 15). There is also a work time constraint,
It was substantially difficult to completely recover SF6 gas. As a result, when a small amount of SF6 gas remained, the lid of the device had to be opened, and SF6 gas was released into the atmosphere.

Further, it is known that a gas-insulated switchgear always has an extremely small amount of leak even in the case where no trouble occurs in the gas airtight structure. Although the control value is as severe as 1% or less per year, SF6 gas leaks into the atmosphere and mixes with air. Although the amount of SF6 gas leaking from one gas-insulated switchgear is extremely small, it is desired to recover the SF6 gas in the gas leaked from the gas-insulated switchgear, considering the total number of operations on a global scale.

As described above, conventionally, it is technically difficult to separate and collect the SF6 gas mixture having a small mixing ratio and the SF6 gas leaking into the air and mixed with air. Since the SF6 gas amount was not large, it was often released to the atmosphere as it was. However, now that environmental protection is a global issue, it is necessary to reduce SF6 gas emissions as much as possible.
The problem was to completely recover up to 6 gases.

The present invention has been proposed to solve the above problems, and its purpose is to collect a small amount of SF6 gas mixed with nitrogen gas or the atmosphere and discharge the SF6 gas into the atmosphere. SF that suppresses the amount and exhibits excellent environmental harmony
A 6 gas collecting apparatus and method thereof.

[0015]

In order to achieve the above object, the present invention provides a small amount of S in nitrogen gas or air.
When F6 gas is mixed, this gas is allowed to pass through the collection column, and SF6 is mixed with the adsorbent packed in the column.
By selectively adsorbing SF6 gas from the gas, the SF6 gas is trapped in the column, whereby it is automatically separated from nitrogen gas and air.

According to a first aspect of the present invention, in a SF6 gas collecting apparatus for collecting only SF6 gas from a mixed gas containing a small amount of SF6 gas in nitrogen gas or air, a gas storage tank for storing the mixed gas is arranged. A collection column for taking in the mixed gas is connected to the gas storage tank, and the collection column is filled with an adsorbent that selectively adsorbs SF6 gas. According to the invention of claim 1, even if the SF6 gas contained in the mixed gas is small in amount, the adsorbent in the collection column selectively adsorbs the SF6 gas. Therefore, S mixed with nitrogen gas or the atmosphere
F6 gas can be collected and recovered. As a result, SF6 gas is not released into the atmosphere, the emission amount of SF6 gas can be suppressed, and it is possible to contribute to environmental protection. Further, the collection column can be decompressed to remove SF6 gas from the adsorbent.
The collection column can be reused while increasing the gas recovery rate.

The invention of claim 2 is the SF6 according to claim 1.
In the gas trap, the adsorbent is composed of synthetic zeolite having a pore size larger than the molecular size of SF6 gas. In the invention of claim 2 as described above,
Even if molecules of nitrogen gas or air enter the pores of synthetic zeolite, SF6 gas has a higher adsorption force than nitrogen gas or air, so it preferentially binds to synthetic zeolite and replaces the molecules of nitrogen gas or air. As a result, SF6 gas molecules enter the pores of the synthetic zeolite. In this way, the synthetic zeolite can selectively collect SF6 gas.

A third aspect of the present invention is the SF6 gas collecting apparatus according to the first or second aspect, wherein a plurality of the collecting columns are connected to the gas storage tank, and the collecting columns are the adsorbents. Are connected in series when adsorbing SF6 gas, and are connected in parallel when desorbing SF6 gas from the adsorbent. According to the invention of claim 3, a plurality of collection columns are prepared, and when the adsorbent adsorbs SF6 gas, the collection columns are connected in series to widen the contact area between the mixed gas and the adsorbent. The adsorption efficiency is improved. On the other hand, when the SF6 gas is desorbed from the adsorbent, the collection columns are connected in parallel to shorten the contact time between the mixed gas and the adsorbent, so that rapid desorption can be realized.

According to a fourth aspect of the invention, in the SF6 gas collecting apparatus according to any one of the first to third aspects, a bypass circuit is provided at an outlet of the collecting column, and a gas is provided in the bypass circuit. It is characterized in that an analyzer is attached. According to the invention of claim 4, the SF6 gas discharged from the collection column can be confirmed by the gas analyzer attached to the bypass circuit, and the effective adsorption time of the collection column can be known.

According to a fifth aspect of the present invention, in the SF6 gas collecting apparatus according to any one of the first to third aspects, a halogen leak detector is attached to the discharge port of the collecting column. . According to the invention of claim 5, the SF6 gas discharged from the collection column by the halogen leak detector can be confirmed, and the adsorption effective time of the collection column can be known as in the fourth invention. In addition to this, since the halogen leak detector is very compact, it can be easily used even in the case of field work, for example.

The invention of claim 6 is the SF6 gas collecting apparatus according to any one of claims 1 to 5, wherein openable and closable valves are installed at both ends of the collecting column, Is detachably connected to the gas storage tank. According to the invention of claim 6 as described above, by closing the valve and then removing the collection column from the gas storage tank, it is possible to immediately replace the one whose adsorption effective time has passed with a new one. Therefore, excellent SF6 gas collection performance can be maintained. Moreover, since the collection column is small and lightweight, and the valves at both ends are closed, S
It is easy and safe to store and transport F6 gas in a confined state. Therefore, it is possible to collect the removed collection columns in one place and perform intensive regeneration work, and it is possible to improve work efficiency.

The invention of claim 7 is the SF6 gas collecting apparatus according to any one of claims 1 to 6, wherein a plurality of the collecting columns are connected to the gas storage tank, and the collecting columns are connected to each other. At the time of replacement, at least one collecting column is always connected to the gas storage tank. According to the invention of claim 7, when the collection column is replaced, at least one collection column is always connected to the gas storage tank.
No loss occurs in the gas collection work. Therefore, the collection work can be performed efficiently.

The invention of claim 8 is the SF6 gas collecting apparatus according to any one of claims 1 to 7, wherein a temperature adjusting device is attached to the collecting column, and the temperature adjusting device is the adsorbent. When the SF6 gas is adsorbed, the temperature of the collection column is set to room temperature or lower, and when the SF6 gas is desorbed from the adsorbent, the temperature of the collection column is set to be higher than the room temperature. According to the eighth aspect of the invention, the adsorption performance is improved by cooling the collection column by the temperature control device during the adsorption of SF6 gas.
The collection amount of F6 gas is improved. On the other hand, when the SF6 gas is desorbed, the temperature control device heats the collection column, so that the SF6 gas can be desorbed quickly. Therefore, the time required to regenerate the collection column can be shortened.

A ninth aspect of the present invention is the SF6 gas trapping apparatus according to any one of the first to eighth aspects, wherein the adsorbent adsorbs SF6 gas in the trapping column when the adsorbent adsorbs SF6 gas. It is characterized in that a cooling means for cooling is attached. According to the invention of claim 9 as described above, the cooling means cools the collection column at the time of adsorbing the SF6 gas, thereby making it possible to exhibit excellent adsorption performance. At this time, as the cooling means, dry ice or ice, which is easily available, or a commercially available cooling sheet can obtain a sufficient effect.
Therefore, it is not necessary to purposely provide a temperature adjusting device, and the structure can be simplified.

A tenth aspect of the present invention is the SF6 gas collecting apparatus according to any one of the first to ninth aspects, wherein the collecting column collects the SF6 gas desorbed from the adsorbent. A tank is connected, and a gas flow meter is installed between the SF6 gas recovery tank and the collection column. According to the tenth aspect of the invention, the regeneration state of the collecting column can be easily confirmed by detecting the flow of the SF6 gas released from the adsorbent with the gas flow meter.

The invention of claim 11 is the SF6 gas collecting apparatus according to any one of claims 1 to 10, wherein the collection column collects SF6 gas separated from the adsorbent. A tank is connected to the SF6 gas recovery tank to separate SF6 gas from other gases.
An F6 gas separation device is connected. In the invention of claim 11, the SF6 gas separated from the adsorbent of the collection column is recovered in the SF6 gas recovery tank, and the SF6 gas in this tank has a high concentration. Therefore, it is possible to easily separate with a conventional SF6 gas separation device, and the recovery rate of SF6 gas is improved.

The invention of claim 12 is the same as claims 1 to 11.
A method of collecting SF6 gas from the air in the equipment room in which a gas-insulated equipment is placed, by using the SF6 gas collection device according to any one of items 1 to 5, wherein the floor of the equipment room is surrounded by the surroundings. Form a pit that is one step lower than that, and take the gas accumulated in the pit into the gas storage tank,
Furthermore, the gas is introduced from the gas storage tank to the collection column. In the invention of claim 12, when the gas-insulated equipment is arranged in the equipment room, a slight amount of SF6 gas leaked from the equipment is heavier than the air in the room, and therefore easily accumulates in the pit lower than the floor surface. Therefore, the SF6 gas content in the gas in the pit is higher than that in other parts of the equipment room. Therefore, it is possible to effectively collect the SF6 gas by guiding the gas accumulated in the pit to the collection column via the gas storage tank.

The invention of claim 13 is the same as claims 1 to 11.
By using the SF6 gas collector according to any one of items 1 to 3, S is selected from the insulating gas sealed in the gas insulating device.
A method for collecting F6 gas, comprising: a vacuum pump for feeding the insulating gas in the gas insulation device to the collection column;
The gas insulating device is provided with a dry gas filling means for filling dry nitrogen gas or dry air, and when the exhaust capacity of the vacuum pump and the pressure inside the gas insulating device become close to equilibrium, the inside of the insulating device The dry gas filling means is filled with dry nitrogen gas or dry air from the dry gas filling means so that the apparent pressure of the dry gas is increased, and the dry nitrogen gas or a mixed gas of dry air and insulating gas is mixed with the dry gas. It is characterized by being incorporated into a collection column.

In the invention of claim 13 as described above,
At the time of recovering the insulating gas, when the exhaust capacity of the vacuum pump and the pressure inside the gas-insulated device are close to equilibrium, the dry gas is sealed from the dry-gas sealing means into the gas-insulated device so that the apparent appearance in the gas-insulated device can be improved. The upper pressure is high. Therefore, the vacuum pump can maintain excellent exhaust efficiency, and the insulating gas in the device can be smoothly sent into the collection column. At this time, the SF6 gas concentration previously filled in the gas insulating device is diluted with the dry gas filled later. That is, the mixed gas collected in the storage tank contains a small amount of SF6 gas. Since the collection column of the present invention can reliably collect such a small amount of SF6 gas, it is an extremely effective SF6 gas collection method in the above gas recovery system.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment according to the present invention will be specifically described with reference to the drawings. Each of the following embodiments is a device for collecting only SF6 gas from a mixed gas containing a small amount of SF6 gas, and is intended for the gas recovered from the gas insulated switchgear.

(1) First Embodiment [Structure] The first embodiment corresponds to the inventions of claims 1 and 2, and as shown in the structure diagram of FIG.
In the embodiment, the gas storage tank 1, the valve 2, the gas flow meter 3 and the collection column 5, and the pipe 6 connecting these elements are the main constituent elements. The gas storage tank 1 is connected to a gas-insulated switchgear (not shown), and the insulating gas is taken in from this device. The insulating gas here is a mixed gas containing nitrogen gas as a main component and a small amount of SF6 gas in order to reduce the amount of SF6 gas used.

FIG. 2 schematically shows the collection column 5. The collection column 5 is the main part of the present embodiment, and SF6 gas is selected from the mixed gas and collected. The collection column 5 has a cylindrical or box-shaped container 7 filled with a particulate adsorbent 4 via a partition plate 8. The inside is filled with an adsorbent 4 that preferentially adsorbs SF6 gas over nitrogen gas. The adsorbent 4 is composed of a synthetic zeolite having a pore diameter of 10 angstrom, and preferentially adsorbs SF6 gas over nitrogen gas.

[Experiment on Adsorption of SF6 Gas on Adsorbent] Here, an experiment on adsorption of the adsorbent 4 will be described. A mixed gas of nitrogen and SF6 containing 5% concentration SF6 was sealed at a pressure of 0.2 MPa in a tank having a capacity of 2850 ml, and the SF6 gas concentration when 10 angstrom synthetic zeolite was placed in this tank was measured. The change in density at this time is shown in FIG. Nitrogen gas and SF
If the six gases have the same adsorptivity, there should be no change in concentration, but in reality the SF6 gas concentration in the tank is low, and the SF6 gas may be more selectively adsorbed by the synthetic zeolite. I understand.

[Operation] As is clear from the above experimental results, according to the present embodiment, when the mixed gas contained in the gas storage tank 1 is introduced into the collection column 5, the mixed gas is When passing through the collection column 5, only the SF6 gas is trapped in the holes of the adsorbent 4. Therefore, the concentration of nitrogen gas gradually increases toward the downstream side of the collection column 5, and only nitrogen gas flows out from the downstream end of the collection column 5. That is, the nitrogen gas in the mixed gas is released from the collection column 5, and only the SF6 gas is adsorbed and concentrated and is contained in the collection column 5.

By the way, when a synthetic zeolite having a pore diameter of 10 Å is used, not only SF6 gas (molecular diameter: about 5.5 Å) but also nitrogen gas (molecular diameter: about 3 Å) has a molecular diameter within this pore diameter. Is sufficiently small that both can be adsorbed. Therefore, SF6
The phenomenon of mainly collecting only gas cannot be explained by the molecular sieving effect, which is characteristic of zeolite, which selectively adsorbs only molecules having a diameter smaller than the pore diameter. Actually, pore size 1
SF6 gas is more strongly adsorbed on 0 angstrom synthetic zeolite than nitrogen or oxygen gas.

The reason for this can be considered as follows. Regarding the strength of the adsorptive power with respect to the zeolite-based adsorbent 4, the past findings of representative molecules are summarized and summarized from the one having the strongest adsorptive power to HF >>H2O>SO2> S.
OF2, (SO2F2)>SF6>CF4>N2> O
2. Argon (Ar)> H2. When a gas in which these gases are mixed flows in the collection column 5 at a certain speed, each simplex gas takes the following states. First,
HF is firmly attached by a chemical reaction. Also, H2
O also has a strong adsorptive power, and once adsorbed, there is almost no possibility that it will come out of the zeolite, and it stops there.

On the other hand, the gas of SO2 or lower rank has a weaker adsorption force than the above-mentioned gases (HF and H2O), and the degree of difference depends on the adsorption force of the gas itself or the flow velocity of the mixed gas. Although there is some, it moves to the downstream side while repeating adsorption and desorption with respect to the adsorbent 4. In the case of the target mixed gas, the nitrogen gas having lower adsorptivity than the SF6 gas, even if it is adsorbed earlier than the SF6 gas, when the SF6 gas having a strong bond with the adsorbent 4 is in the vicinity, Preference is given to ties with gas.

Therefore, as a result, the nitrogen gas is exchanged and trapped in the pores of the adsorbent 4. However, since the SF6 gas is not firmly and completely bonded to the adsorbent 4, the SF6 gas is repeatedly desorbed and adsorbed to the adsorbent 4 although its degree is lower than that of the nitrogen gas. Then, it moves to the downstream region along the flow of the entire mixed gas, and leaves the collection column 5 when a certain time has elapsed. After the collection column 5 has taken in the mixed gas, S
The time until the F gas flows out is defined as the effective adsorption time of the collection column 5. The effective time of the collection column 5 is determined by the capacity of the collection column 5 and the flow rate of the mixed gas.

Further, the collection column 5 can be decompressed to remove the SF6 gas from the adsorbent 4. This is called regeneration (or reactivation) of the collection column 5. Even if this regenerated collection column 5 is used, SF
Recapture of 6 gases is possible. As a method of regenerating the zeolite-based adsorbent 4, in addition to decompression treatment, a method of flowing a gas such as nitrogen gas and rinsing to regenerate it is conceivable.
This rinsing method is not a desirable method because the concentrated SF6 gas is diluted with nitrogen gas again and a mixed gas is newly prepared by rinsing. In addition,
It is desirable to fill the regenerated collection column 5 with dry nitrogen gas at a pressure of about 0.12 MPa, which is slightly higher than atmospheric pressure. As a result, it is possible to prevent the infiltration of moisture and the like in the air, and avoid the deterioration of the adsorption performance.

Regarding the flow of the mixed gas, when the gas storage tank 1 has a pressure of atmospheric pressure plus alpha, the gas naturally flows to the right side in the figure due to the internal pressure only by opening the valve 2. Further, if the open / closed state of the valve 2 is set appropriately, the gas flow meter 3 is not always necessary. However, as will be described later in detail, since the adsorption effective time of the collection column 5 can be known from the gas flow rate to the collection column 5, if the gas flow meter 3 is installed, the collection column 5 is maintained. It is convenient above.

[Effect] According to the first embodiment as described above, by using the synthetic zeolite having a larger pore size than the SF6 gas as the adsorbent 4, the nitrogen gas and the SF6 gas are mixed due to the difference in the adsorption power. Only SF6 gas can be selectively collected from the gas. Therefore, only the nitrogen gas in the mixed gas is released to the atmosphere, and as a result, the SF6 gas is concentrated in the collection column 5. Therefore, the collected mixed gas can be finally managed as a small volume, and the recovery rate of SF6 gas is improved.

Conventionally, a mixed gas containing a slight to small proportion of SF6 gas had to be released into the atmosphere. However, in the present embodiment, since only the SF6 gas can be easily collected from the mixed gas, it is released into the atmosphere. SF6 gas is not released and SF
The discharge amount of 6 gas can be suppressed. As a result, it is possible to contribute to environmental conservation, and it is possible to exert excellent environmental harmony.
Further, the collection column 5 can be reused by desorbing the SF6 gas from the adsorbent 4, and also in this respect, the load on the environment can be suppressed.

In the above embodiment, a 10 Å type synthetic zeolite is used as the adsorbent 4, but zeolites having various pore diameters have been developed and it is necessary to stick to 10 Å type. Needless to say, the same effect can be obtained even if the size is 8 or 9 angstroms, as long as it is a hole capable of capturing SF gas molecules. Further, although the mixed gas of SF6 gas and nitrogen has been described here, a mixed gas of SF6 gas and air, such as a mixed gas of SF6 gas and air, can be applied as long as the gas system is separated from the SF6 gas to some extent. It is a wide technology.

(2) Second Embodiment [Structure] The second embodiment corresponds to the inventions of claims 3 and 4. In the second embodiment, as shown in FIG.
A point provided with five collection columns 5a to 5e connected by a pipe 6 and a bypass circuit 6 at the outlet of the collection column 5e.
It is characterized in that b is provided and the gas analyzer 10 is attached thereto. These collection columns 5a to 5e are used for the adsorbent 4
Are connected in series when adsorbing SF6 gas.
Further, when the SF6 gas is desorbed from the adsorbent 4, the collection columns 5a to 5e are disconnected once and connected in parallel.

[SF when multiple collection columns are connected
6 Experiment on Gas Collection Capability] Here, the collection column 5a
7 shows experimental data for a collection capacity of ~ 5e. In FIG. 5, the cylinder 11 is filled with SF6 / N2 mixed gas having a concentration of 5% at a high pressure, simulating the recovered gas storage tank 1 in FIG. The collection columns 5a to 5e are connected in series of 5 series. Further, for the purpose of experimentation, a gas sampling port was specially attached to each outlet so that the adsorption state of each of the collection columns 5a to 5e could be known so that the gas could be sampled and analyzed. (The sampling position for the experiment is shown in Fig. 5.
(Indicated by the dashed arrow inside).

Each of the collection columns 5a to 5e has a diameter of 90 mm ×
A cylindrical shape having a length of 550 mm was filled with about 2 kg of a synthetic zeolite having a pore diameter of 10 Å as the adsorbent 4 in each of them. The 5% SF6 gas standard gas is passed through the column with the gas flow meter 3 at a flow rate of about 6 liters per minute, and gas sampling is performed from the discharge port every predetermined time, and the gas chromatograph (GC) is performed by the gas analyzer 10. Analysis was performed to estimate the SF6 gas adsorption state. It is considered that the SF6 gas was not discharged until 9.5 hours from the start of the test, and the SF6 gas in the mixed gas flowing during this period was collected in the collection columns 5a to 5e. The results of these tests are shown in Table 1.

[0047]

[Table 1]

As can be seen from this experiment, the collection column 5
The collection capacity of SF6 gas by ~ 5e is proportional to the number of connected columns, and the mixed gas is about 3.4 m3 in terms of atmospheric pressure.
(6 × 60 × 9.5 = 3420 liters),
About 170 liters of SF6 gas (3
420 × 0.05 = 171 liters) is the collection column 5a
It means that it was collected in ~ 5e. In other words, by separating the excess nitrogen gas and releasing it into the atmosphere, the SF6 / N2 mixed gas of about 3.4 m3 was finally reduced to the column volume of 17.5 liters of SF6 gas. It can be said that it was possible (the calculation formula is 4.5 × 4.5 ×
3.14 x 55 x 5 = 17500 ml).

[Operation] As is apparent from the above experimental results, in the second embodiment, the gas storage is achieved by selectively collecting the SF6 gas in the five collecting columns 5a to 5e. Compared with the case of managing the mixed gas collected in tank 1, it is possible to reduce the amount of managed gas to about 0.5% or less (17.5 / 3420) by narrowing down to 6 gases. Becomes Thereby, the collection column 5a-
Storage after collection with 5e becomes very easy. Moreover,
In the second embodiment, the SF6 gas discharged from the collection column 5e can be confirmed by the gas analyzer 10 attached to the bypass circuit 6b. Therefore,
It is possible to know the effective adsorption time of the entire collection columns 5a to 5e.

In the second embodiment, SF6
By connecting the collection columns 5a to 5e in series at the time of adsorbing the gas, it is possible to increase the chances of the mixed gas coming into contact with the adsorbent 4 and at the same time to increase the residence time,
It is possible to obtain the effect of increasing the SF6 gas adsorption efficiency of the synthetic zeolite. On the other hand, when the SF6 gas adsorbed on the adsorbent 4 is to be released and reactivated, the connection between the collection columns 5a to 5e is once disconnected, and the collection columns 5a to 5e are reconnected in parallel to each other. The separated SF6 gas is prevented from coming into contact with the adsorbent 4. Therefore, the SF6 gas can be quickly discharged to the outside from the collection columns 5a to 5e, the regeneration efficiency of the adsorbent 4 is improved, and the SF6 gas is released while the collection columns 5a to 5e are connected in series. Compared with, it became possible to reproduce in about 1/5 of the time. (This is because, when regenerating in series, for example, the SF6 gas released in the collection column 5e sequentially passes through 5d, 5c, 5b, and 5a, and adsorption and desorption with the adsorbent 4 are repeated each time, which requires time. ).

[Effect] As described above, according to the second embodiment, in the gas analyzer 10, the collection columns 5a ...
By analyzing the SF6 gas discharged from 5e, the adsorption effective time of the collection columns 5a to 5e can be accurately grasped. Moreover, the adsorption effect of SF6 gas can be made higher in the second embodiment in which the collection column 5 is substantially divided into five blocks, rather than being one long collection column.

It should be noted that although the number of collection columns here is five, there is no problem whether it is of a two-connection type or a ten-connection type. However, since the effective adsorption time of the collection column is almost proportional to the number of columns to be connected, connecting too many numbers causes a problem such as pressure loss due to ventilation resistance. Therefore, it is important to select the number of connected collection columns while considering the pressure loss.

Further, in the above experiment, the concentration of SF6 gas was set to 5%, but it was confirmed that the same adsorption characteristics could be obtained by using SF6 gas having a concentration of 1%, and finally it was 0.5%. It was confirmed that there was no problem in collecting even a mixed gas with a concentration of%. Therefore, theoretically and experimentally, it was found that a small proportion of SF6 gas, such as SF6 gas leaking, can be collected. From these results, it was found that the SF6 gas concentration dependency of the mixed gas to be introduced with respect to the effective adsorption time of the collection column was almost absent in the above concentration range.

[Modification of Second Embodiment] FIG. 6 shows a second embodiment.
The modification of the embodiment of is shown. The example shown in FIG. 6 is characterized in that a three-way cock 9 is attached to a branch point of the pipe 6. In this embodiment, the three-way cock 9 is operated to switch the path of the mixed gas, and the collection columns 5a ...
The series connection and the parallel connection of 5e can be easily switched.

(3) Third Embodiment [Structure] The third embodiment shown in FIG. 7 corresponds to the invention of claim 5. This embodiment is characterized in that a halogen leak detector 10a is attached to the discharge port of the collection column 5e instead of the gas analyzer 10. Table 2 below shows the results of the halogen leak detector 1 when the above-mentioned SF6 gas collecting ability was tested.
It is an experimental result using a normal SF6 gas leak detector as 0a.

[0056]

[Table 2]

[Operation] Comparing Table 2 with Table 1 above, it can be seen that the presence or absence of detection of the SF6 gas leak detector and the test results by gas chromatography are in good agreement. That is, the SF6 gas discharged from the collection column 5e can also be confirmed by the halogen leak detector 10a.

[Effect] In the third embodiment, the halogen leak detector 10a can be used to detect the effective adsorption time of the collection columns 5a to 5e as in the second embodiment. . Moreover, since the halogen leak detector 10a is extremely compact, it has an advantage that it can be easily used even in the field.

(4) Fourth Embodiment [Structure] The fourth embodiment corresponds to claim 6,
As shown in FIG. 8, the characteristic is that valves 2 a and 2 b that can be opened and closed are installed at both ends of the collection column 5.
Is detachably connected to the pipe 6. Further, SF6 gas is released from the adsorbent 4 to collect the gas in the collection column 5.
When regenerating, the pressure reducing (vacuum) pump 12 is connected to the valve 2b side, and the pressure reducing (vacuum) pump 12 is further connected to the SF6 gas recovery tank 13 for recovering the SF6 gas separated from the adsorbent 4. .

[Operation] When the collection column 5 is regenerated, one valve 2a of the adsorption column 5 is closed and the valve 2 is closed.
Connected to the decompression (vacuum) pump 12 with b open,
The decompression (vacuum) pump 12 is operated to decompress the adsorption column 5, and the SF6 gas released from the adsorbent 4 is recovered in the gas recovery tank 13. Further, in the fourth embodiment, it is possible to remove from the pipe 6 with the valves 2a and 2b at both ends of the collection column 5 closed. At this time, if a commercially available one-touch type joint is used as the connection structure to the pipe 6, the collection column 5 can be detached from the pipe 6 in a few seconds. It is possible to store the SF6 gas in a confined state and carry a plurality of them together to another place.

[Effect] According to the fourth embodiment as described above, the valves 2a and 2b at both ends of the collection column 5 can be closed and the collection column 5 can be easily removed from the pipe 6. Even if a plurality of collection columns 5 that have adsorbed SF6 gas are stored, the collection columns 5 are small, lightweight and safe.
Can be easily transported in a batch. Therefore, the removed collection column 5 can be collected at a place different from the SF6 gas collection work, and the regeneration work can be efficiently performed at one time. Moreover, when the effective adsorption time of the collection column 5 has passed, it can be immediately replaced with a new collection column 5. Therefore, it is possible to always maintain excellent collection efficiency.

By the way, when a plurality of collection columns 5 are regenerated, it is disadvantageous to connect the collection columns 5 to each other in series as described above, and the collection columns 5 are connected in parallel to separate SF6 gas. However, it is advantageous not to touch the adsorbent 4 as much as possible. Actually, when a plurality of collection columns 5 are connected, it takes almost the same number of times as the number of connected columns, and extra regeneration time is required as compared with the case where they are connected one by one. Therefore, in order to efficiently perform the regenerating work of the collection column 5, it is effective to collectively perform the regenerating work.

Therefore, when the collecting column 5 is regenerated, a plurality of decompressing (vacuum) pumps 12 are attached in parallel to each other, so that it is possible to simultaneously perform the regenerating work on the plurality of collecting columns 5. Φ90mm × 550 mentioned above
In the case of the collection column 5 having a size of mm, the regenerating work usually takes several days. Therefore, the regenerating work can be speeded up by simultaneously performing the regenerating work on the plurality of collection columns 5. .

[Modification of Fourth Embodiment] Also, the fourth embodiment
As a modified example of the above embodiment, in the embodiment in which a plurality of collection columns 5 are connected to the gas storage tank 1, at least one collection column 5 is removed when the collection columns 5 are removed.
Always connected to the gas storage tank 1. This embodiment corresponds to the invention of claim 7, and at the time of replacing the collection column 5, at least one collection column 5 is always connected to the gas storage tank. Can be continuously performed, and the work time can be shortened.

(5) Fifth Embodiment [Structure] Next, a fifth embodiment corresponding to claim 8 will be described. The fifth embodiment is characterized in that a temperature control device is attached to the collection column 5. The temperature control device is configured to make the temperature of the collection column 5 below room temperature when the adsorbent 4 adsorbs SF6 gas, and to make the temperature of the collection column 5 higher than room temperature when desorbing SF6 gas from the adsorbent 4. ing.

[Experiment on SF6 Gas Adsorption by Temperature] It was found that the recovery column 5 itself can be regenerated, but it has been known that the regenerating operation takes a considerable amount of time. Therefore, in order to explore the possibility of improvement in SF6 gas adsorption and desorption properties, a mixed gas and zeolite were placed in a container under the experimental conditions shown in Table 3 and the change in SF6 gas concentration was observed to obtain a zeolite with a pore size of 10 Å. A basic experiment was conducted on the adsorbability of SF6 gas to the. Table 4 shows the SF6 gas concentration in the container.

[0067]

[Table 3]

[0068]

[Table 4]

For example, the SF6 gas absorption of -30 ° C zeolite was calculated as follows. SF6 total amount: 2580 ml × 3 × 0.05 = 387 ml SF6 amount remaining in the gas phase: 2580 ml × 3 × 0.000
9 = 7.0 ml Adsorption SF6 amount on zeolite: 387-7.0 = 380
ml Therefore, the SF6 gas adsorbed on the unit zeolite is
SF6 / zeolite = 380ml / 150g = 2.53g
Becomes

As can be seen from Table 4 above, the amount of SF6 gas adsorbed on the zeolite depends on the temperature. The graph shown in FIG. 9 shows the temperature dependence of the adsorption force for SF6 gas at 10 Å. As is clear from this graph, it can be said that the SF6 gas adsorption amount sharply decreases above room temperature.

The temperature at which the adsorbed SF6 gas is desorbed from the adsorbent 4 and the collection column 5 is regenerated is preferably higher than room temperature, preferably about 100 ° C. using a mantle heater or the like. The collecting column 5 is heated. Then, decompression processing is performed using a vacuum pump having an exhaust capacity of 100 / min.

[Operation] In the fifth embodiment, the temperature dependence of the SF6 gas adsorption and desorption properties is utilized. When the adsorbent 4 adsorbs SF6 gas, the temperature of the collection column 5 is kept at room temperature. The adsorption performance can be enhanced as follows. On the other hand, when desorbing the SF6 gas from the adsorbent 4, the temperature of the collection column 5 can be set higher than room temperature to improve the desorption rate of the SF6 gas. For example, about 100
When the collection column 5 is heated to ℃, the SF in about 4 to 5 hours.
Six gases can be recovered, and the time required for work can be shortened to about 1/10 of the work time at room temperature.

[Effect] According to the fifth embodiment as described above, by adjusting the temperature of the collection column 5 by the temperature control device, the adsorption performance of SF6 gas is enhanced and the collection amount of SF6 gas is increased. At the same time, the collection column 5 can be quickly regenerated by quickly releasing the SF6 gas.

[Modification of Fifth Embodiment] The fifth embodiment
The following modifications are included in the embodiment. That is, ice or dry ice, or a commercially available cooling sheet may be used as the cooling means for cooling the collection column 5 during SF6 gas adsorption (corresponding to the invention of claim 9).
The results of investigating the ability to collect SF6 gas in the case where two adsorption columns 5 having the dimensions described above are used and cooled with dry ice are shown below.

The adsorption column 5 was cooled with dry ice, and the collection operation was started after about 1 hour. The mixed gas amount was about 4 m3 at a flow rate of 6 to 20 liters per minute,
SF6 gas is not detected from the tips of the collection columns 5a and 5b. This is a mixed gas throughput of 1.4 m at room temperature.
It has reached at least about 3 times that of 3, and it is possible to obtain a great effect that the adsorption performance and the collection amount are increased. According to such an embodiment, in addition to the fifth embodiment, since ice, dry ice, or a cooling sheet can be obtained anywhere, it is possible to obtain the operational effect of contributing to the simplification of the configuration.

(6) Sixth Embodiment [Structure] In the sixth embodiment, as shown in FIG. 10, a gas flow meter 3 is added to the structure of the fourth embodiment. This corresponds to the invention of claim 10. Gas flow meter 3
Is installed between the SF6 gas recovery tank 13 and the collection column 5.

[Operation] To confirm whether or not the regeneration work of the collection column 5 is completed, the decompression work is stopped and pure nitrogen gas is introduced from the outside of the collection column 5, and SF6 gas is mixed into the nitrogen gas. It is common to judge whether or not there is. However, in the actual regeneration operation, the introduction of the nitrogen gas in this manner increases the amount of gas to be recovered, and therefore it must be kept to a minimum. The sixth embodiment deals with this problem.

That is, when regeneration of the collection column 5 is insufficient, the SF6 gas is still partially adsorbed by the adsorbent 4, and this SF6 gas is released from the adsorbent 4, so that the gas flow meter 3 detects the amount of gas. The flow can be observed. On the contrary, when the gas flow meter 3 stops detecting the flow of gas, it can be determined that the regeneration work of the collection column 4 is completed. More specifically, it was found that when the gas flow meter 3 stopped counting the gas flow and the pressure was continuously reduced for about 1 hour, almost 100% SF6 gas was recovered and the adsorbent 4 was regenerated. The gas flow meter 3 is extremely expensive when it is a precise measuring instrument whose performance accurately measures the flow velocity or cumulative flow rate under a reduced pressure condition. But,
Since the gas flow meter 3 used in the present embodiment only detects the presence or absence of a gas flow, it is not always necessary to use such a strict measuring instrument, and a commercially available gas flow meter is sufficient.
No worries about increased financial costs.

[Effect] According to the sixth embodiment as described above, by installing the gas flow meter 3 between the SF6 gas recovery tank 13 and the adsorption column 5, the collection column 5
The presence or absence of the SF6 gas flow desorbed from the column can be seen, and from this it can be seen whether the adsorbed substance of the synthetic zeolite in the collection column 5 has disappeared, that is, whether the collection column 5 has been regenerated. Therefore, when introducing the pure nitrogen gas from the outside of the collection column 5 to know the regeneration state, it is not necessary to introduce the pure nitrogen gas from the outside, and the volume of the gas to be recovered can be minimized. As a result, it is possible to contribute to making the SF6 gas recovery tank 13 compact and improving the efficiency of the gas recovery operation.

(7) Seventh Embodiment [Structure] The seventh embodiment corresponds to claim 11. As shown in FIG. 11, the SF6 gas recovery tank 13 is provided with an SF6 liquefying / separating device 17 and It is characterized in that the SF6 liquid tank 18 is connected. SF6 liquefaction separation device 1
Reference numeral 7 is for taking in the SF6 gas flowing out from the SF6 gas recovery tank 13 and separating the SF6 gas from other gases to liquefy the SF6 gas by cooling when the other gas is mixed. The SF6 liquid tank 18 is for storing the liquid phase SF6 sent from the SF6 liquefaction separation device 17.

[Operation] In the seventh embodiment as described above, the SF6 gas released from the adsorbent 4 of the collection column 5 is recovered in the SF6 gas recovery tank 13, but the SF6 gas flowing out from the SF6 gas recovery tank 13 is recovered. Keeps a sufficiently high concentration, even if other gases are mixed. Therefore, the SF6 liquefaction separation device 17 may be a conventional adsorption system or membrane separation system. Gases other than the SF6 gas separated by the SF6 liquefying / separating device 17 are released to the atmosphere.

[Effect] According to the seventh embodiment described above, the SF6 gas is collected using the collection column 5, and the SF6 gas is stored in the SF6 gas recovery tank 13 as the collection column 5 is regenerated. As a result, the concentration of SF6 gas can be increased in the closed gas system. Then, in the conventional F6 liquefied gas separator 17, S in the tank 13
Since the F6 gas can be recovered, the recovery rate of the SF6 gas is improved, and it is possible to suppress the load on the environment and contribute to environmental protection.

(8) Eighth Embodiment [Configuration] An eighth embodiment corresponding to claim 12 will be described with reference to FIG. Reference numeral 14 in FIG.
Shows a gas-insulated device filled with SF6 gas. 8th
The embodiment is a method of collecting SF6 gas from the air in the equipment chamber 15 in which the gas insulation equipment 14 is arranged by using the SF6 gas collection device including the collection column 5. The pit 16 has been lowered to the floor in the equipment room 15.
Is being dug. Decompression (vacuum) pump 1 in pit 16
2 are connected, and the SF6 gas collecting apparatus according to the first embodiment is arranged therein. The SF6 gas collector uses the gas stored in the pit 16 to store the gas in the gas storage tank 1.
It is designed to be introduced into the collecting column 5 and then to the collecting column 5.

[Operation] As described in the prior art,
In the gas-insulated switchgear, there is an extremely small amount of gas leak even if no problem occurs in the gas airtight structure. That is, the eighth
In the embodiment, a slight amount of SF6 gas leaked from the gas-insulated equipment 14 exists in the equipment room 15. At this time, since the SF6 gas has a higher specific gravity than air, it accumulates in the pit 16 provided in the lower portion in a state of being mixed with air. Before the mixed gas accumulated in the pit 16 is diffused in the entire equipment chamber 15, it is collected and stored in the gas storage tank 13 by the decompression (vacuum) pump 12 and led to the collection column 5 via this. In the collection column 5, the adsorbent 4 selectively adsorbs the SF6 gas, so that the SF6 gas can be concentrated and collected from the mixed gas.

Considering the adsorbing power between air and SF6 gas in the adsorbent 4, nitrogen gas and oxygen gas, which are the main components of air, are similar to each other, and both have a lower adsorption rank than SF6 gas. Therefore, only the SF6 gas is collected in the adsorbent 4 in the collection column 5 and can be separated from the nitrogen gas and the oxygen gas without any problem. The equipment room 15
When the air inside is collected, the collected gas also contains moisture in the atmosphere. Since this water strongly adsorbs to the adsorbent in the collection column 5, there is a possibility that its adsorption performance will be deteriorated. Therefore, it is desirable to separately place a dehumidifying agent in the pipe 6 located in the gas storage tank 1 or upstream of the collection column 5 to remove water and then dry.

[Effect] According to the eighth embodiment as described above, the air in the equipment chamber 15 in which the gas insulation equipment 14 is arranged is collected, and even a small amount of SF6 gas contained therein is collected. be able to. The amount of SF6 gas leaking from one gas-insulated switchgear 14 is extremely small, but considering the total number of operations in the world, S leaked from the gas-insulated switchgear.
The amount of F6 gas rises to a considerable extent, and by recovering it, it is possible to greatly contribute to global environmental conservation.

(9) Ninth Embodiment [Structure] In the ninth embodiment, as in the case of the eighth embodiment, SF6 gas is collected using the SF6 gas collecting apparatus including the collecting column 5. It is a collection method. The ninth embodiment corresponds to claim 13, and as shown in FIG. 13, the collection column 5 is connected to the gas insulation device 14 via the decompression (vacuum) pump 12, and the gas insulation device 14 is connected. 1 enclosed in 14
SF6 gas with a concentration of 00% is directly introduced into the collection column 5. Further, the gas insulating device 14 is connected to a dry gas filling means 19 for filling dry nitrogen gas or dry air. The operation timing of the dry gas charging means 19 is a time point when the exhaust capacity of the decompression (vacuum) pump 12 and the pressure inside the gas insulation device 14 are close to equilibrium.

[Operation] When performing an internal inspection of the gas insulation device 14, the depressurization (vacuum) pump 12 sends SF6 gas from the gas insulation device 14 to the collection column 5. At this time, when the exhaust capacity of the decompression (vacuum) pump 12 and the pressure inside the gas insulation device 14 become close to equilibrium, the dry gas charging means 19 operates to fill the gas insulation device 14 with dry nitrogen gas or dry air. To do. Therefore, the SF6 gas can be smoothly sent to the collection column 5 without the apparent pressure inside the gas insulation device 14 increasing and the exhausting capability of the decompression (vacuum) pump 12 decreasing. At this time, although the concentration of SF6 gas is reduced by the dry nitrogen gas or the dry air, the collection column 5 can selectively capture a small amount of SF6 gas.

For example, when the exhaust capacity of the pump 12 and the pressure equilibrium inside the gas insulation device 14 are reached at 0.01 MPa, nitrogen gas is added to increase the pressure 10 times to 0.1 MPa.
When the collection operation is finally completed at 0.01 MPa, the conventional SF6 gas residual amount can be reduced to about 1/10 by using the collection column 5. In addition, the dimensions (φ9
It is possible to treat a mixed gas of about 10 m3 when it is cooled with dry ice for about 1 hour in five collection columns 5A to 5E having a cylindrical shape having a length of 0 mm x 550 mm). Therefore, the tank of the gas insulation device 14 has a diameter of 2 m and a length of 3 m.
Such a large size can also be accommodated, and there is no problem in terms of practicality.

[Effect] According to the ninth embodiment as described above, when the SF6 gas is recovered from the gas insulation device 14, the exhaust capacity of the decompression (vacuum) pump 12 and the pressure in the gas insulation device 14 are reduced. After approaching the equilibrium, the apparent pressure in the gas insulation device 14 can be increased by enclosing dry nitrogen gas or dry air from the dry gas encapsulating means 19. Therefore, the decompression (vacuum) pump 1
2 can maintain a high level of exhaust efficiency, and can smoothly feed SF6 gas from the inside of the gas insulating device 14 to the collection column 5 side. At this time, the concentration of the 100% -concentration SF6 gas previously sealed in the gas insulation device 14 is lowered by the dry gas sealed later. That is, although the amount of SF6 gas contained per unit volume is small, the collection column 5 can selectively capture a small amount of SF6 gas in the mixed gas as described above.

In the conventional gas recovery system, although a small amount of SF6 gas remains in the gas insulation device 14, the device 14
The lid was opened and SF6 gas was released into the atmosphere. On the other hand, according to the ninth embodiment, the collection column 5 can collect the SF6 gas, and the gas discharged to the atmosphere is only a gas having a low load on the environment such as nitrogen, which greatly contributes to environmental protection. can do.

[0092]

As described above, according to the present invention,
With a simple device, only the SF6 gas can be efficiently separated and collected from the SF6 gas leaking into the air and the mixed gas containing the SF6 gas with a very low concentration, and the emission amount of the SF6 gas to the atmosphere can be suppressed. In addition, it can be reused and contribute to the conservation of the global environment.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a collection column according to the first embodiment.

FIG. 3 is a graph showing experimental data on mixed gas adsorption of 10 Å type zeolite.

FIG. 4 is a configuration diagram showing a second embodiment of the present invention.

FIG. 5 is a configuration diagram showing a method of investigating the SF6 gas collecting ability in the second embodiment.

FIG. 6 is a configuration diagram showing a modified example of the second embodiment.

FIG. 7 is a configuration diagram showing a third embodiment of the present invention.

FIG. 8 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 9 is a graph showing the temperature dependence of the adsorption force for SF6 gas at 10 Å.

FIG. 10 is a configuration diagram showing a sixth embodiment of the present invention.

FIG. 11 is a configuration diagram showing a seventh embodiment of the present invention.

FIG. 12 is a configuration diagram showing an eighth embodiment of the present invention.

FIG. 13 is a configuration diagram showing a ninth embodiment of the present invention.

FIG. 14 is a graph showing the relationship between the pressure inside the equipment and the time when SF6 gas is recovered from the gas insulated equipment.

FIG. 15 is a conceptual diagram showing an example of a conventional mixed gas recovery device.

[Explanation of symbols]

1 ... Gas storage tank 2 ... Valve 3 ... Gas flow meter 4 ... Adsorbent 5 ... Collection column 6 ... Piping 7 ... Container 8 ... Partition board 9 ... three-way cock 10 ... Gas analyzer 10a ... Halogen leak detector 11 ... Cylinder filled with mixed gas 12 ... Decompression (vacuum) pump 13 ... SF6 gas recovery tank 14 ... Gas insulation equipment 15 ... Equipment room 16 ... pit 17 ... SF6 liquefaction separation device 18 ... SF6 liquid tank 19. Dry gas filling means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01N 30/54 G01N 30/54 F 30/62 30/62 Z H01H 33/56 H01H 33/56 C H02B 13 / 055 H02G 5/06 371Z H02G 5/06 371 H02B 13/06 M (72) Inventor Takahiro Imai 2-1, Ukishimacho, Kawasaki-ku, Kawasaki-shi, Kanagawa F-term (reference) 4D012 BA02 in Hamakawasaki Plant, Toshiba Corporation CA10 CA20 CB16 CD05 CE01 CE02 CF02 CF04 CF05 CF10 CG02 CJ05 5G017 DD07 5G028 GG05 5G365 DM01

Claims (13)

[Claims] 1. An SF for collecting only SF6 gas from a mixed gas containing a small amount of SF6 gas in nitrogen gas or air.
In the 6-gas collection device, a gas storage tank for storing the mixed gas is arranged, a collection column for taking in the mixed gas is connected to the gas storage tank, and SF6 gas is selectively supplied to the collection column. An SF6 gas trapping device, which is filled with an adsorbent that adsorbs. 2. The SF6 gas trapping device according to claim 1, wherein the adsorbent is made of synthetic zeolite having a pore size larger than the molecular size of SF6 gas. 3. A plurality of the collection columns are connected to the gas storage tank, the collection columns are connected in series when the adsorbent adsorbs SF6 gas, and the SF6 gas is separated from the adsorbent. The SF6 gas trapping apparatus according to claim 1 or 2, wherein the SF6 gas trapping apparatus is connected in parallel at the time. 4. The SF according to claim 1, wherein a bypass circuit is provided at an outlet of the collection column, and a gas analyzer is attached to the bypass circuit.
6 gas collectors. 5. The SF6 gas collecting apparatus according to claim 1, wherein a halogen leak detector is attached to an outlet of the collecting column. 6. A valve that can be opened and closed is installed at both ends of the collection column, and the collection column is detachably connected to the gas storage tank. The SF6 gas collector according to any one of the above items. 7. A plurality of the collection columns are connected to the gas storage tank, and when the collection columns are replaced, at least one collection column is always connected to the gas storage tank. The SF6 gas trapping device according to any one of claims 1 to 6, characterized in that 8. A temperature control device is attached to the collection column, the temperature control device sets the temperature of the collection column to room temperature or lower when the adsorbent adsorbs SF6 gas, and removes the SF6 gas from the adsorbent. The SF6 gas trapping device according to any one of claims 1 to 7, wherein the SF6 gas trapping device is configured to raise the temperature of the trapping column to above room temperature when the SF6 gas is trapped. 9. The adsorbent is SF6 in the collection column.
The SF6 gas trapping apparatus according to any one of claims 1 to 8, further comprising a cooling unit that cools the trapping column when adsorbing a gas. 10. An SF6 gas recovery tank for recovering SF6 gas separated from the adsorbent is connected to the collection column, and a gas flow meter is installed between the SF6 gas recovery tank and the collection column. The SF6 gas trapping device according to any one of claims 1 to 9, wherein 11. An SF6 gas recovery tank for recovering the SF6 gas separated from the adsorbent is connected to the collection column, and the SF6 gas recovery tank separates the SF6 gas from other gases. The SF6 gas trapping device according to any one of claims 1 to 10, wherein the device is connected. 12. A method for collecting SF6 gas from the air in the equipment room in which a gas insulation device is arranged, by using the SF6 gas collection device according to any one of claims 1 to 11. A pit lower than the surroundings is formed on the floor surface of the equipment room, the gas accumulated in the pit is introduced into the gas storage tank, and the gas is introduced from the gas storage tank to the collection column. A method for collecting SF6 gas, comprising: 13. A method for collecting SF6 gas from an insulating gas sealed in a gas insulating device by using the SF6 gas collecting device according to any one of claims 1 to 11. A vacuum pump that feeds the insulating gas in the gas insulating device to the collection column; and a dry gas filling means that fills the gas insulating device with dry nitrogen gas or dry air, and the exhaust capacity of the vacuum pump and the When the pressure inside the gas insulating device becomes close to equilibrium, dry nitrogen gas or dry air is sealed from the dry gas sealing means into the gas insulating device so that the apparent pressure in the insulating device becomes high. A method for collecting SF6 gas, wherein the dry nitrogen gas or a mixed gas of dry air and insulating gas is introduced into the collection column.