JP2003190704A - Gas recovery method and gas recovery apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas recovery method capable of drastically increasing a treatment speed and capable of certainly and easily recovering gas to be recovered, and a gas recovery apparatus therefor. <P>SOLUTION: The gas recovery apparatus 10 is constituted so as to recover only one kind of gas from a mixed gas containing at least two kinds of gases and equipped with a recovery pipe main body 14 having an introducing part 13 for introducing the mixed gas and permitting the mixed gas introduced from the introducing part 13 to pass, a gas recovery pipe 11 having a lead-out port 15 for leading out the gas remaining after one kind of the gas is recovered from the mixed gas and a cooling means 12 for cooling the gas recovery pipe 11 so as to be capable of cooling the mixed gas when the mixed gas passes through the gas recovery pipe 11 while cooling one kind of the gas so as to lower the vapor pressure thereof. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas recovery method and a gas recovery device.

[0002]

2. Description of the Related Art In a leak test of an LNG underground tank or an LNG tank mounted on an LNG ship, a halogen compound such as sulfur hexafluoride (SF ₆ ) or carbon tetrafluoride (CF ₄ ) is contained in the atmosphere or nitrogen gas. A mixed gas mixture may be used. Halogen compounds are known as substances that destroy the ozone layer, so after the leak test, halogen compounds such as sulfur hexafluoride or carbon tetrafluoride mixed in the atmosphere or nitrogen gas are released into the atmosphere. It is necessary to collect it so that it does not end up.

As an example of a gas recovery device for recovering sulfur hexafluoride among halogen compounds, sulfur hexafluoride molecules are adsorbed on zeolite (adsorbent) contained in an adsorption column to convert sulfur hexafluoride There is something to collect.

[0004]

However, such a recovery device which is currently on the market has a processing speed of 1 or less.
9 to 15 liters per minute (liter), that is, 440 to 900 liters per hour, which is slow and has a total amount of 200,000 Nm ^3.
NG underground tank and LNG with a total volume of 120,000-140,000 Nm ^3.
Mixed gas (tracer gas) that has completed the tank leak test of the ship
There was a problem that it took too long to process.

The present invention has been made in view of the above circumstances, and a gas recovery method and a gas that can dramatically improve the processing speed and can reliably and easily recover the gas to be recovered. The purpose is to provide a recovery device.

[0006]

In order to solve the above-mentioned problems, the gas recovery method and the gas recovery apparatus of the present invention employ the following means. That is, according to the gas recovery method of claim 1, there is provided a gas recovery method for recovering only one kind of gas from a mixed gas composed of at least two kinds of gas, and recovering the mixed gas by cooling the mixed gas. The one type of gas to be cooled is cooled so that the vapor pressure thereof becomes small, and the gas corresponding to the reduced vapor pressure of the one type of gas is frosted and recovered. And

In this gas recovery method, the gas to be recovered is cooled, so that a portion corresponding to the vapor pressure at the cooled temperature remains as a gas, and a portion exceeding the vapor pressure becomes frost. , Will be separated from the mixed gas and recovered.

According to a second aspect of the gas recovery method, there is provided a gas recovery method for recovering only one kind of gas from a mixed gas composed of at least two kinds of gas, and the mixed gas passes through the inside. A step of preparing a gas recovery pipe for recovering the one type of gas therein, a step of cooling the inside of the gas recovery tube in advance, and a step of introducing the mixed gas into the gas recovery tube. The mixed gas is cooled as the mixed gas passes through the inside of the gas recovery pipe, and the one type of gas is cooled so that its vapor pressure becomes smaller, Frosting a gas of a type inside the gas recovery pipe;
It is characterized by including.

In this gas recovery method, the gas to be recovered becomes frost by being cooled so that the vapor pressure thereof becomes small, and this frost adheres / accumulates inside the gas recovery pipe, that is, frost forms. As a result, the mixed gas is separated and recovered.

According to the third aspect of the gas recovery apparatus, the gas recovery apparatus recovers only one kind of gas from the mixed gas composed of at least two kinds of gas, and the mixed gas is introduced into the inside. Inlet, a recovery pipe body configured such that the mixed gas introduced from the inlet passes through the inside, and the remaining gas after the one type of gas is recovered from the mixed gas is discharged. A gas recovery pipe having a discharge port, and the mixed gas is cooled as the mixed gas passes through the inside of the gas recovery pipe. And a cooling unit capable of cooling the gas so that the vapor pressure thereof becomes small.

In this gas recovery device, the gas to be recovered becomes frost by being cooled so that its vapor pressure becomes small, and is separated from the mixed gas and recovered.

According to the gas recovery apparatus of the fourth aspect, in the gas recovery apparatus of the third aspect, the cooling means has an accommodation space capable of accommodating the entire gas recovery pipe, and The inside of the accommodation space is filled or supplied with a coolant.

In this gas recovery apparatus, the entire gas recovery tube is immersed in the cooling means in which the storage space is filled or supplied with the cooling agent.

According to the gas recovery apparatus of the fifth aspect, in the gas recovery apparatus of the third aspect, the cooling means is disposed inside the gas recovery tube in parallel with the longitudinal direction of the gas recovery tube. Further, at least one coolant supply pipe is provided, and the coolant is made to flow inside the coolant supply pipe.

In this gas recovery apparatus, at least one coolant supply pipe is provided inside the gas recovery pipe, and the interior of the gas recovery pipe is filled with the coolant flowing inside the coolant supply pipe. It will be cooled.

According to the gas recovery apparatus of the sixth aspect, in the gas recovery apparatus of the third aspect, the one type of gas is collected as frost or mist inside the gas recovery pipe. It is characterized in that it is provided with a collecting means that can do so.

In this gas recovery device, the gas to be recovered becomes frost or mist by being cooled so that the vapor pressure becomes small, and these become frost or mist, and these adhere to or accumulate on the collecting means to remove the gas from the mixed gas. It will be separated and collected.

According to the gas recovery apparatus of the seventh aspect, in the gas recovery apparatus of the sixth aspect, the collecting means is provided in the vicinity of the outlet of the gas recovery pipe, and one end thereof is the above-mentioned. It is characterized in that it comprises a truncated cone-shaped filter member that is tapered toward the inlet of the gas recovery pipe and has its other end abutting the inner wall surface of the gas recovery pipe.

In this gas recovery apparatus, the frosted gas adheres to and deposits on the outer surface of the truncated cone from the bottom to the top.

According to an eighth aspect of the gas recovery device of the present invention, in the gas recovery device of the fourth or fifth aspect, the coolant is liquid nitrogen.

In this gas recovery device, liquid nitrogen is used as a coolant.

According to the gas recovery apparatus of the ninth aspect, in the gas recovery apparatus of the eighth aspect, the liquid nitrogen is cooled after cooling the gas recovery tube and before being introduced into the gas recovery tube. It is characterized in that it is used to cool the mixed gas in advance.

In this gas recovery apparatus, the liquid nitrogen, which has finished cooling the gas recovery tube, cools the mixed gas introduced from the tank to the gas recovery tube, and the mixed gas is cooled in advance.

According to the gas recovery device of the tenth aspect,
The gas recovery apparatus according to claim 7, wherein the filter member is made of glass wool.

In this gas recovery apparatus, it is preferable to use inexpensive glass wool as the filter member.

According to the gas recovery apparatus of the eleventh aspect,
The gas recovery apparatus according to claim 3, wherein the one type of gas is a halogen compound.

In this gas recovery device, the halide is recovered from the mixed gas.

According to the gas recovery device of claim 12,
The gas recovery apparatus according to claim 11, wherein the halogen compound is sulfur hexafluoride (SF ₆ ).

In this gas recovery device, sulfur hexafluoride (SF ₆ ) used as a tracer gas in the leak test of the LNG tank is recovered from the mixed gas.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As shown in Figure 1,
A gas recovery device 10 according to the present invention includes a gas recovery pipe 11 and
The cooling means 12 is configured as a main element. The gas recovery pipe 11 introduces a mixed gas (air + sulfur hexafluoride, nitrogen gas + sulfur hexafluoride, etc.) used for a tank leak test such as an LNG tank into the inside thereof, and the introduction port 13. A hollow recovery tube main body 14 so that the mixed gas introduced from the port 13 passes through the inside thereof, and an outlet port 15 from which the atmosphere or the nitrogen gas from which halides such as sulfur hexafluoride have been removed is led out from the mixed gas. Is to have.

A mixed gas introduction pipe 16 communicating with the inside of a tank such as an LNG tank is connected to the introduction port 13 so that the mixed gas exiting the LNG tank is introduced into the recovery pipe body 14. . Further, the recovery pipe body 14 is
For example, a stainless steel tube having a diameter of 89 mm and a length of 2800 mm is closed at both ends with a disk-shaped member made of the same stainless steel. Further, in the outlet 15, in order to release the atmosphere or the nitrogen gas from which the halide such as sulfur hexafluoride has been removed from the mixed gas into the atmosphere, or to introduce it to a heat exchanger (described later) located on the downstream side thereof. The lead-out pipe 17 of is connected.

With this configuration, the mixed gas introduced into the gas recovery pipe 11 through the inlet 13 provided at one end of the gas recovery pipe 11 flows through the gas recovery pipe 11 from the left side to the right side in FIG. It flows toward the outside and is led out to the outside of the gas recovery pipe 11 from the outlet 15 provided at the other end of the gas recovery pipe 11.

The cooling means 12 is the gas recovery pipe 14 described above.
Has an accommodation space S capable of accommodating the whole. A coolant (for example, liquid nitrogen) can be filled, stored, or supplied in the accommodation space S. That is, the entire gas recovery pipe 14 is immersed in the coolant so that the inside of the gas recovery pipe 11 is cooled.

For example, when sulfur hexafluoride is to be recovered, the concentration of sulfur hexafluoride in the mixed gas is 10 pp.
In order to reduce the pressure to m or less, the internal space of the gas recovery pipe 11 is
The mixed gas passing through the gas recovery pipe 11 is -160 ° C.
It must be cooled so that it is cooled to This is because the sulfur hexafluoride vapor pressure (vertical axis) and temperature (horizontal axis)
This is because there is a relationship as shown in FIG. That is, the vapor pressure of sulfur hexafluoride becomes 1 × 10 ⁻⁵ atm or less when the temperature becomes −160 ° C. or less, and the gas having a concentration of more than 10 ppm solidifies until the concentration becomes 10 ppm or less. .

Thus, when the mixed gas is cooled to -160 ° C. or lower while passing through the inside of the gas recovery pipe 11, only sulfur hexafluoride in the mixed gas solidifies, that is, in the case of FIG. Frost adheres to and accumulates on the inner wall surface of the recovery pipe body 14 and is recovered.

Further, as shown in FIG. 3, the gas recovery pipe 11
It is more advantageous if the trapping means 18 capable of trapping the coagulated frost-like sulfur hexafluoride is provided inside the. The collecting means 18 may be any filter member having air permeability, and examples thereof include glass wool, sponge, cotton, ceramic filters, stainless sintered filters, and stainless wire filters. Among them, glass wool is inexpensive and has a suitable size of eyes, and particularly excellent effects are exhibited in the present invention.

Such a collecting means 18 is used for the gas recovery pipe 1
It is preferable to be arranged in the inside of 1, especially near the outlet 15. That is, sulfur hexafluoride in the mixed gas that is gradually cooled while passing through the inside of the gas recovery pipe 11 is sufficiently cooled to be solidified and become frost-like, and is attached to the collecting means 18. To do so.

Further, it is more advantageous if the collecting means 18 has a shape as shown in FIG. That is, one end extends in a tapered shape to the vicinity of the inlet 13 of the gas recovery pipe 11, and the other end extends out the outlet 1 of the gas recovery pipe 11.
5 is a truncated cone or a conical shape that is configured to extend to the vicinity of 5 and contact the inner wall surface of the gas recovery pipe 11 with its outer peripheral surface. When the collecting means 18 is made of glass wool, a wire mesh for holding the tapered shape is wound so that the tapered shape does not lose its shape. By forming the trapping means 18 into such a truncated cone or conical shape, the frost of sulfur hexafluoride that has gradually adhered and accumulated from the inner wall surface side of the gas recovery pipe 11 gradually extends toward the inlet 13. As a result, clogging of the collecting means 18 is prevented. That is, frost gradually begins to adhere / accumulate from the portion where the outer peripheral surface of the collecting means 18 and the inner wall surface of the gas recovery pipe 11 contact each other, and the outer peripheral surface of the collecting means 18 and the inner wall surface of the gas recovery pipe 11 become Frost gradually fills the space between them. On the other hand, the central portion of the collecting means 18 does not frost until the end, and the air permeability is maintained until the end, so that clogging is prevented.

Next, another embodiment of the gas recovery apparatus according to the present invention will be described with reference to FIG. As shown in FIG.
The gas recovery device 20 includes a gas recovery pipe 21 and a cooling means 22.
It is composed mainly of and. The gas recovery pipe 21 has an inlet 23 for introducing the mixed gas (atmosphere + sulfur hexafluoride, nitrogen gas + sulfur hexafluoride, etc.) used for the tank leakage test of the LNG tank, and the like.
A hollow recovery pipe main body 24 through which the mixed gas introduced from the inlet 23 passes, and an outlet 25 from which the atmosphere or nitrogen gas from which the halide such as sulfur hexafluoride has been removed is led out from the mixed gas. Is to have.

A mixed gas introduction pipe 26 communicating with the inside of a tank such as an LNG tank is connected to the introduction port 23 so that the mixed gas exiting the LNG tank is introduced into the recovery pipe body 24. . In addition, the recovery pipe body 24,
For example, it is a stainless steel tube having a diameter of 89 mm and a length of 2800 mm. Further, in the outlet 25, in order to release the atmosphere or the nitrogen gas from which the halide such as sulfur hexafluoride has been removed from the mixed gas into the atmosphere, or to introduce it to a heat exchanger (described later) located downstream thereof. Outlet pipe 2
7 is connected.

In the present embodiment, the cooling means 22 comprises three coolant supply pipes 22 arranged inside the gas recovery pipe 21.
It is composed of a. Each of the coolant supply pipes 22a is arranged such that its own longitudinal axis is substantially parallel to the longitudinal axis of the gas recovery pipe 21 and penetrates a disk-shaped member that closes the openings at both ends of the gas recovery pipe 21. Has been done. Inside the coolant supply pipes 22a, a coolant (for example, liquid nitrogen) supplied from a separately provided coolant supply source (not shown) via a pipe or the like flows. As a result, the inside of the gas recovery pipe 21 is cooled and heat exchange with the fluid passing through the inside of the gas recovery pipe 21 is performed. The coolant flowing out of the coolant supply pipe 22a is released to the atmosphere as it is, guided to a heat exchanger described later, or recovered after passing through the heat exchanger.

That is, the mixed gas introduced into the inside of the gas recovery pipe 21 from the inlet 23 provided at one end of the gas recovery pipe 21 has the inside of the gas recovery pipe 21 from the left side to the right side in FIG. As it flows to the outside, it is cooled to an ultralow temperature and guided to the outside of the gas recovery pipe 21 through the outlet 25 provided at the other end of the gas recovery pipe 21.

As described above, in the inside of the recovery pipe main body 21, for example, when sulfur hexafluoride is to be recovered, the mixed gas passing through the gas recovery pipe 11 is -16.
It is necessary to cool to 0 ° C or lower.

As described above, when the mixed gas is cooled to −160 ° C. or lower while passing through the inside of the recovery pipe body 21, only sulfur hexafluoride in the mixed gas is solidified, that is, the inner wall surface of the gas recovery pipe 11. In addition, it becomes frost on the outer wall surface of the coolant supply pipe 22a to be adhered / accumulated and collected.

Also in the present embodiment, the sulfur hexafluoride contained in the mixed gas can be more effectively recovered by providing the collecting means 18 described above. Collection means 1
Since 8 is the same as that described above, the description thereof is omitted here.

In the embodiment described above, the mixed gas passing through the gas recovery pipes 11 and 21 is cooled to an ultralow temperature, and for example, sulfur hexafluoride contained in the mixed gas is solidified (vapor pressure). Liquid nitrogen is used to make it zero. However, the coolant of the present invention is not limited to liquid nitrogen, and any coolant can be used as long as the same effect can be obtained.

Next, FIG. 6 shows the result of an experiment conducted by using the gas recovery apparatus shown in FIG. The processed mixed gas is
Nitrogen gas contained sulfur hexafluoride at a concentration of 0.1% and was fed at a rate of 30 Nm ³ per hour (500 liters per minute) for 28 hours. In the graph shown in FIG. 6, the horizontal axis represents time, and the vertical axis represents sulfur hexafluoride gas concentration (pp
m) and the temperature inside the tube (° C).

As can be seen from FIG. 6, the temperature inside the gas recovery pipe 11 becomes lower toward the pipe inlet (inlet) 13, the center of the pipe, and the pipe outlet (outlet) 15, and particularly the pipe outlet (guide). It can be seen that the temperature at the outlet 15 is maintained at about -160 ° C or lower. Also, most of the gas concentrations coming out from the pipe outlet (outlet) 15 show a value of 0,
It can be seen that sulfur hexafluoride is almost certainly recovered.
Numerically, 98% or more of sulfur hexafluoride is recovered.

Further, in this experiment, one gas recovery pipe 1
It has been proved that 1 can process 30 Nm ³ of gas per hour. Therefore, the gas recovery pipes 11 are arranged in parallel,
For example, if 100 pieces are connected, the amount that can be processed in 1 hour is 3000 Nm ³ . That is, the time required to process the mixed gas that has undergone the leakage inspection of the LNG underground tank having a total amount of 200,000 Nm ³ is about 66.7 hours, which cannot be realized by the conventional gas recovery device. The result is that the work time can be greatly reduced.

In order to further increase the efficiency of the entire apparatus, it is further advantageous to provide a precooling device 30 for precooling the mixed gas introduced into the apparatus as shown in FIG. This precooling device 30 is used for the first stage heat exchanger 3
1, the 2nd stage heat exchanger 32, the 1st communicating pipe 33 which connects the 1st stage heat exchanger 31 and the outlet 15 of the gas recovery pipe 11, and the coolant vaporized and vaporized in the accommodation space S (for example, liquid The second communication pipe 34 capable of introducing (nitrogen) to the second stage heat exchanger 32 is provided. That is,
The gas that has cooled out from the gas recovery pipe 11 is the first communication pipe 33.
The low temperature gas that has been led to the first-stage heat exchanger 31 through the tank and cooled from the tank is further cooled, and the low-temperature gas that has evaporated in the storage space S passes through the second communicating pipe 34 and the second-stage heat exchanger 34. To further cool the mixed gas coming from the first stage heat exchanger 32. If the mixed gas can be cooled in this way, the flow path of the mixed gas cooled by passing through the gas recovery pipe 11 can be shortened. That is, the length of the gas recovery pipe 11 can be shortened, and the device can be downsized.

On the tank side (upstream side) of the first stage heat exchanger 31, a flow rate adjusting valve 35 that opens and closes in conjunction with a temperature sensor (not shown) provided at the pipe outlet (outlet) 15.
Can be provided. This flow rate adjusting valve 35
Reduces the flow rate of the mixed gas when the temperature of the pipe outlet (outlet port) 15 becomes higher than a desired temperature (for example, -170 ° C.), and the temperature of the pipe outlet (outlet port) 15 becomes the desired temperature. When it becomes lower than the temperature (for example, −170 ° C.), the flow rate of the mixed gas is increased. This ensures that the temperature of the pipe outlet (outlet) 15 is always the desired temperature, in other words, the gas recovery pipe 11
Since the internal temperature is always kept at a temperature at which sulfur hexafluoride solidifies at a desired vapor pressure, sulfur hexafluoride can be recovered more efficiently. The flow rate adjusting valve 35 does not necessarily have to be provided on the upstream side of the first stage heat exchanger 31, and the introduction ports 13 and 23 of the above-described embodiment are not necessarily required.
Of course, it can be provided near the upstream side of the.

Incidentally, the one shown in FIG. 7 is the first stage heat exchanger 31.
And two heat exchangers of the second stage heat exchanger 32 are provided, but the precooling device 30 is not limited to this.
For example, only one heat exchanger may be provided, and the cooled gas may be introduced into the heat exchanger via the first communication pipe 33 and the second communication pipe 34.

Further, instead of the gas recovery device 10 shown in FIG. 7, the gas recovery device shown in FIG. 5 can be applied. In this case, the coolant flowing out from the three coolant supply pipes 22a is guided to the second stage heat exchanger 32 via a communication pipe similar to the second communication pipe 34 shown in FIG.

[0054]

According to the gas recovery method and the gas recovery apparatus of the present invention, the following effects can be obtained. According to the gas recovery method of claim 1, since the gas to be recovered becomes frost-like by being cooled so that the vapor pressure becomes small, the gas to be recovered is easily separated from the mixed gas. There is an effect that it can be collected and recovered.

According to the gas recovery method of claim 2,
The gas to be collected becomes frost-like by being cooled so that its vapor pressure becomes small, and this frost adheres and accumulates inside the gas recovery pipe. There is an effect that it can be easily separated and collected.

According to the gas recovery apparatus of the third aspect,
The gas to be collected becomes frost-like by being cooled so that its vapor pressure becomes small, and this frost adheres and accumulates inside the gas recovery pipe. There is an effect that it can be easily separated and collected.

According to the gas recovery device of the fourth aspect,
Since the entire gas recovery pipe is immersed in the cooling means in which the coolant is filled or supplied in the accommodation space, the entire gas recovery pipe can be cooled uniformly.

According to the gas recovery apparatus of the fifth aspect,
At least one coolant supply pipe is provided inside the gas recovery pipe, and the inside of the gas recovery pipe is cooled by the coolant flowing inside the coolant supply pipe. It is possible to cool the gas recovery pipe through which the gas passes from the inside and also to collect and accumulate frost on the outer peripheral surface of the coolant supply pipe, so that the gas to be recovered can be recovered more efficiently. Has the effect.

According to the gas recovery device of the sixth aspect,
The gas to be collected becomes frost-like by being cooled so that its vapor pressure becomes small, and this frost adheres to and accumulates on the collection means. In addition, there is an effect that it can be reliably separated and collected.

According to the gas recovery device of the seventh aspect,
The frosted gas gradually adheres and accumulates from the bottom of the truncated cone to the top, and the central flow passage is maintained until the frost blocks the top. Therefore, it is possible to prevent clogging of the filter member due to frost and to continue to use the filter member for a long time.

According to the gas recovery apparatus of the eighth aspect,
Since cheap liquid nitrogen is used as the coolant, there is an effect that the equipment cost can be kept low.

According to the gas recovery device of the ninth aspect,
The liquid nitrogen that has finished cooling the gas recovery pipe cools the mixed gas introduced from the tank to the gas recovery pipe, and the mixed gas is cooled in advance, so that liquid nitrogen can be used effectively and efficiently. In addition, the length of the gas recovery pipe required to cool the mixed gas can be shortened, and the device can be downsized.

According to the gas recovery apparatus of the tenth aspect, since inexpensive glass wool is used as the filter member, there is an effect that the equipment cost can be kept low.

According to the gas recovery apparatus of the eleventh aspect, it is possible to reliably and easily recover the halide which causes the destruction of the ozone layer.

According to the gas recovery apparatus of the twelfth aspect, sulfur hexafluoride (S
F ₆ ) can be reliably and easily recovered.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view showing an embodiment of a gas recovery apparatus according to the present invention.

FIG. 2 is a graph showing the relationship between vapor pressure and temperature of sulfur hexafluoride (SF ₆ ), which is one of the substances to be recovered by the gas recovery device according to the present invention.

FIG. 3 is a schematic side sectional view showing a state in which a collecting means is provided inside a gas recovery pipe of the gas recovery device shown in FIG.

FIG. 4 is a schematic side sectional view showing that the collecting means shown in FIG. 3 has a truncated cone shape.

FIG. 5 is a schematic side sectional view showing an embodiment of a gas recovery device according to the present invention.

6 is a graph showing the results of an experiment conducted using the gas recovery device shown in FIG.

FIG. 7 is a schematic configuration diagram showing a gas recovery device according to the present invention further equipped with a precooling device.

[Explanation of symbols]

10 gas recovery equipment 11 Gas recovery pipe 12 Cooling means 13 entrance 14 Recovery pipe body 15 Outlet 18 Collection means 20 gas recovery equipment 21 Gas recovery pipe 22 Cooling means 22a Coolant supply pipe 23 entrance 24 Recovery pipe body 25 Outlet S accommodation space

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4D019 AA01 AA02 BA04 BB13 CA10                       CB04                 4D058 JA60 JB05 JB32 SA15 SA20                       TA01 UA03                 4D076 AA01 AA15 AA24 BC02 BC06                       BC23 BC25 BE03 CD28 FA03                       FA18 HA03 JA01 JA03

Claims (12)

[Claims] 1. A gas recovery method for recovering only one kind of gas from a mixed gas composed of at least two kinds of gases, wherein the gas to be recovered is cooled by cooling the mixed gas.
A method for recovering a gas, characterized in that a gas corresponding to a reduced vapor pressure of the one type of gas is recovered by cooling so that the vapor pressure of each of the gases becomes small. 2. A gas recovery method for recovering only one kind of gas from a mixed gas composed of at least two kinds of gases, wherein the mixed gas passes through the inside and the one kind of gas is contained inside the mixed gas. Preparing a gas recovery pipe to be recovered, precooling the inside of the gas recovery pipe, the mixed gas is introduced into the gas recovery pipe, the mixed gas of the gas recovery pipe As the mixed gas is cooled as it passes through the inside, the one type of gas is cooled so that its vapor pressure becomes small,
And a step of frosting a gas of a kind inside the gas recovery pipe. 3. A gas recovery device for recovering only one kind of gas from a mixed gas composed of at least two kinds of gases, the inlet being for introducing the mixed gas into the inside, and being introduced from the inlet. A recovery pipe body configured to allow the mixed gas to pass therethrough;
When a gas recovery pipe having an outlet for discharging the remaining gas after recovering the types of gas, and cooling the gas recovery pipe, and the mixed gas passing through the inside of the gas recovery pipe A cooling means capable of cooling the mixed gas while cooling the mixed gas such that the vapor pressure of the one type of gas becomes small;
A gas recovery device comprising: 4. The gas recovery apparatus according to claim 3, wherein the cooling means has a housing space capable of housing the entire gas recovery pipe, and a cooling agent is provided inside the housing space. A gas recovery device that is filled or supplied. 5. The gas recovery apparatus according to claim 3, wherein the cooling means includes at least one coolant supply pipe arranged inside the gas recovery pipe in parallel with a longitudinal direction of the gas recovery pipe. A gas recovery device, characterized in that a coolant is made to flow inside the coolant supply pipe. 6. The gas recovery apparatus according to claim 3, wherein the gas recovery pipe is provided with a collection means capable of collecting the one type of gas as frost or mist. A gas recovery device. 7. The gas recovery apparatus according to claim 6, wherein the collecting means is provided in the vicinity of the outlet of the gas recovery pipe, and one end of which is located toward the inlet of the gas recovery pipe. A gas recovery device comprising a truncated cone-shaped filter member which is tapered toward the other end and is configured so that the other end thereof contacts the inner wall surface of the gas recovery pipe. 8. The gas recovery device according to claim 4 or 5, wherein the coolant is liquid nitrogen. 9. The gas recovery apparatus according to claim 8, wherein the liquid nitrogen is used for previously cooling the mixed gas after cooling the gas recovery pipe and before being introduced into the gas recovery pipe. A gas recovery device. 10. The gas recovery device according to claim 7, wherein the filter member is made of glass wool. 11. The gas recovery device according to claim 3, wherein the one type of gas is a halogen compound. 12. The gas recovery device according to claim 11, wherein the halogen compound is sulfur hexafluoride (SF ₆ ).