JPH07280189A - Method and device for collecting fluorocarbon - Google Patents

Abstract

PURPOSE:To provide collecting technology capable of collecting a large volume of fluorocarbon gas of high purity. CONSTITUTION:The liquid component of the liquefied fluorocarbon gas is transferred to a collecting tank 2 with the self-pressure in a storing container 1. Then, the fluorocarbon gas is separated from the gas for pressurizing by introducing the mixed gas of the gas component in the storing container 1 with the gas for pressurizing which is enclosed in the storing container to a cooling and liquefying tank 8 with the inner pressure of the storing container 1 to be cooled and liquefied, and the fluorocarbon gas is liquefied. The gas component left in the storing container 1 and the gas for pressurizing is introduced in the cooling and liquefying tank 8 by a suction pump 31 to be cooled and liquefied, and the fluorocarbon gas is separated from the gas for pressurizing to liquefy the fluorocarbon gas. The temperature of the cooling and liquefying tank 8 is risen, and the liquefied fluorocarbon gas is transferred to the collecting tank 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for recovering fluorine-based gas, and more particularly to a method and apparatus for recovering halon 1301 and halon 1211 used as fire extinguishing agents.

[0002]

2. Description of the Related Art Conventionally, a fluorine-based gas has been used as a refrigerant or a fire extinguishing agent of a refrigerator by utilizing its chemical and thermal properties. And, conventionally, this fluorine-based gas has been released to the atmosphere at the time of periodic inspection of the fire extinguisher and at the time of discarding the refrigerator.

[0003]

However, if the fluorine-based gas is released into the atmosphere, it may cause the destruction of the ozone layer surrounding the earth. Therefore, the release of certain fluorine-based gas into the atmosphere is subject to the regulation. Production was also suspended. However, in certain fields, halon gas or fluorine-based gas may have to be used, so technology for recovering fluorine-based gas is required. Currently, fluorine-based gas is efficiently recovered in high purity. I can't find a way. The present invention has been made in view of such a point, and an object thereof is to provide a recovery method and a recovery apparatus capable of recovering a large amount of fluorine-based gas with high purity.

[0004]

In order to achieve the above-mentioned object, the first aspect of the present invention uses the liquefied fluorine-based gas stored in a storage container, and most of the liquid component in the storage container itself. The first recovery procedure of recovering the recovery tank by pressure, and the gas component in the storage container and the pressurizing gas sealed in the storage container after the completion of the first recovery procedure are transferred to the cooling liquefaction tank by the internal pressure of the storage container. A second recovery procedure for supplying and separating the fluorine-based gas component and the pressurizing gas and liquefying the fluorine-based gas, and a suction pump for the mixed gas of the pressurizing gas and the gas component remaining in the storage container. Is introduced into the cooling liquefaction tank via
By cooling and liquefying, the fluorine-based gas and the pressurizing gas are separated and the third recovery procedure for liquefying the fluorine-based gas and the cooling liquefaction tank are heated to liquefy in the second recovery procedure and the third recovery procedure. It is characterized in that the liquefied gas of the fluorine-based gas is recovered in the recovery tank in the fourth recovery procedure.

Further, according to the present invention, a recovery passage for connecting the device for recovering the liquefied fluorine-based gas to a storage container storing the liquefied fluorine-based gas is connected to a recovery tank, and the recovery passage collects the liquid component. It is characterized in that a channel and a gas component recovery channel are arranged in parallel, a cooling liquefaction tank is attached to the gas component recovery channel, and a heating means such as an electric heater is disposed in the cooling liquefaction tank.

[0006]

In the present invention, first, the liquid component of the liquefied fluorinated gas is transferred to the recovery tank by its own pressure in the storage container, and then the mixed gas of the gas component and the pressurizing gas in the storage container is pressurized to the internal pressure of the storage container. By introducing into the cooling liquefaction tank and cooling and liquefying, the fluorine-based gas and the pressurizing gas are separated, the fluorine-based gas is liquefied, and the remaining gas components that cannot be derived by self-pressure and the pressurizing gas are mixed. The gas is introduced into the cooling liquefaction tank by a suction pump to liquefy the cooling and separate it into a fluorine-based gas and a pressurizing gas to liquefy the fluorine-based gas, and the fluorine-based gas liquefied in the cooling liquefaction tank is collected in a recovery tank. Since it is transferred, almost all of the liquefied fluorine-based gas in the storage container can be recovered in the recovery tank, and the pressurizing gas used for pressurization is separated and released into the atmosphere.
The recovered liquefied fluorine-based gas has a high purity and does not contain the pressurizing gas.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings are flowcharts of a fire extinguishing halon gas recovery apparatus showing an embodiment of the present invention. This fire extinguishing halon recovery device is a storage container that contains the halon to be recovered.
(1) and the recovery tank (2) are connected by a recovery path (3) for communication.

The recovery passageway (3) is constituted by connecting the liquid component recovery passageway (4) and the gas component recovery passageway (5) in parallel, and the differential pressure is closer to the storage container (1) side than the branch portion. Switch (6) and safety valve
(7) is arranged. In addition, a cooling liquefaction tank (8) is provided in the gas component recovery path (5), and the cooling liquefaction tank is diverted from the branch portion.
Electromagnetic flow path on-off valve (9) and pressure switch (10) between (8)
And the safety valve (11) are arranged in order. An electromagnetic flow passage opening / closing valve (12) is arranged in the liquid component recovery passageway (4).

The cooling liquefaction tank (8) is an adiabatic storage tank (13),
The heat exchanger (14), the electric heater (15) for heating the upper half of the heat insulating storage tank (13), and the supercooling heat exchanger (16) arranged in the lower half of the heat insulating storage tank (13). A liquid nitrogen storage container (17) is connected in communication with the cooling liquefaction tank (8). The liquid nitrogen discharged from the liquid nitrogen storage container (17) is discharged to the outside from the cooling nitrogen gas discharge valve (18) via the supercooling heat exchanger (16) and the heat exchanger (14). It has become so. Further, the gas flowing in the gas component recovery passageway (5) exchanges heat with liquid nitrogen in the heat exchanger (14) to be cooled and then flows into the gas-liquid separator (19). The condensate outlet passage (20) led out from the bottom wall of (13) joins the liquid component recovery passageway (4). A differential pressure switch (21) and an electromagnetic on-off valve are connected to the condensate outlet (20).
The (22), the low temperature pump (23) and the warmer (24) are arranged in this order from the adiabatic storage tank (13).

Further, a vaporized gas outlet passage (25) is led out from the upper portion of the recovery tank (2), and the vaporized gas outlet passage (25) is provided.
The leading end of the vaporized gas outlet passage (2) is connected to the gas component recovery passageway (5) on the inlet side of the cooling liquefaction tank (8).
5) Pressure switch (26), pressure-holding valve (27), solenoid on-off valve (28),
A safety valve (29) is installed. Also, the gas component recovery path (5)
The residual gas extraction / gas replacement passage (30) is provided in such a manner that the inlet portion of the cooling liquefaction tank (8) and the liquid component recovery passage (4) are in communication with each other. A diaphragm pump (31) for suction work is provided in (30). And
Diaphragm pump with residual gas extraction and gas replacement path (30)
A discharge passage (32) is branched and led out from a portion of the discharge passage (31).

In the figure, reference numeral (33) is an electronic digital platform scale on which the storage container (1) is mounted, (34) is a liquid level gauge for detecting the liquid level in the adiabatic storage tank (13), and (35) is cooling liquefaction. Thermometer for measuring the temperature of recovered gas in the heat exchanger (14) of the tank (8), (36) is an adiabatic storage tank (13)
Thermometer for detecting condensate temperature inside, (37) is thermometer (35) (36)
Based on the detected temperature of the liquefied nitrogen, a cooling nitrogen gas discharge valve (18) arranged in the supply path (38) and an electromagnetic flow rate adjustment valve arranged in the separation gas discharge path (39) derived from the adiabatic storage container (13) (40)
A temperature controller that controls the opening and closing of the liquefied nitrogen storage container (41).
This is a liquid level gauge that detects the amount of liquid in 7).

A fire extinguishing halon recovery procedure in the fire extinguishing halon recovering device thus configured will be described. ◎ Preparation procedure First, the storage container (1) containing the collected halon is placed on the electronic digital platform scale (33), and the recovery path (3) is placed in the storage container.
Connect to the main valve (42) of (1), input the value obtained by adding a constant weight (eg, 7 kg) to the empty container weight as a set value to the electronic digital platform scale (33), and activate the diaphragm pump (31). To exhaust the air from the connecting piping system.

Further, the amount of liquefied nitrogen in the liquefied nitrogen storage container (17) is confirmed by a liquid level gauge (41), and a cooling nitrogen gas is inserted in a liquefied nitrogen supply passage (38) by a temperature controller (37). The discharge valve (18) is controlled to cool the inside of the cooling liquefaction tank (8) to a predetermined temperature.

◎ First recovery procedure When the above preparatory work is completed, the electromagnetic flow passage opening / closing valve (12) mounted on the liquid component recovery passageway (4) is opened, and the container main valve of the storage container (1) is opened. The valve (42) is opened, and the halon liquid and the dissolution pressurizing gas stored in the storage container (1) are sent under pressure to the recovery tank (2) by the internal pressure of the storage container (1).

A differential pressure switch is provided in which a differential pressure between the internal pressure in the storage container (1) and the recovery tank (2) is installed in the recovery path (3).
When (6) is detected, the electromagnetic flow passage opening / closing valve (12) attached to the liquid component recovery passageway (4) is closed and the first recovery procedure is completed.

Second recovery procedure Next, the on-off valve (9) attached to the gas component recovery passageway (5) is opened, and the mixed gas of the gas component of the halon gas and the nitrogen gas for pressurization in the storage container (1) is opened. It is introduced into the cooling liquefaction tank (8). At this time, since the cooling liquefaction tank (8) is cooled to a predetermined temperature by the preparation procedure, the introduced mixed gas is cooled by the cooling liquid while flowing through the heat exchanger (14) of the cooling liquefaction tank (8). It is cooled by exchanging heat with nitrogen, the halon gas is liquefied due to the difference in condensation temperature between the fluorine-based gas and the nitrogen gas for pressurization, and the liquefied halon gas is separated from the nitrogen gas for pressurization by the gas-liquid separator (19). It is stored in the adiabatic storage tank (13).

It is desirable that the cooling temperature in the cooling liquefaction tank (8) is close to the solidification temperature of the halon gas (for example, -160 ° C. in the case of halon 1301).
This cooling temperature is confirmed by controlling the opening and closing of the cooling nitrogen gas release valve (18) with the output from the temperature controller (37) based on the detection of the adiabatic storage tank temperature by the thermometer (36). Confirmation of liquefaction is confirmed with a thermometer (35) that detects the outlet temperature of the heat exchanger (14), and when the detected temperature becomes higher than -100 ° C, the electromagnetic flow rate adjustment valve of the separation gas discharge path (39). (40) is closed to prevent halon gas from being mixed with the nitrogen gas for pressurization and released to the atmosphere.

When the temperature detected by the thermometer (35) for detecting the outlet temperature of the heat exchanger (14) becomes lower than -100 ° C, the electromagnetic flow rate control valve ( Four
0) is opened and nitrogen gas is discharged from the separation gas discharge passage (39). When the pressure switch (10) arranged in the gas component recovery path (5) detects a predetermined pressure, the electromagnetic flow path opening / closing valve (9)
The valve is closed, and the electromagnetic flow passage opening / closing valve (43) and the discharge passage of the diaphragm pump (31) are installed in the suction passage of the diaphragm pump (31) in the residual gas extraction / gas replacement passage (30). The electromagnetic flow path on-off valve (44) is opened to start the third recovery procedure.

◎ Third recovery procedure The residual gas remaining in the storage container (1) and the nitrogen gas for pressurization are attached to the residual gas extraction / gas replacement passage (30), an electromagnetic flow passage opening / closing valve (43) (44) The diaphragm pump (3
Operate 1) to feed into the cooling liquefaction tank (8) and liquefy it, and separate halon gas and nitrogen gas. When all the halon gas and the pressurizing nitrogen gas are sucked out from the storage container (1), the container main valve (42) is closed. Instead of closing the container valve (42), the electromagnetic flow passage on-off valve (43) mounted on the residual gas extraction / gas replacement passage (14) is closed and the atmosphere release valve arranged on the recovery passage (3) is closed. It is also possible to open (45) and introduce the atmosphere into the storage container (1).

When the third recovery procedure is completed, the main valve (42) of the storage container (1) is closed and the storage container (1) is removed. When the pressure switch (26) detects that the pressure in the recovery tank (2) has risen due to vaporization of the liquefied halon and separation of the nitrogen gas dissolved in the liquefied halon, the recovery tank
The electromagnetic on-off valve (28) mounted on the vaporized gas outlet passage (25) connecting the upper part of (2) and the gas component recovery passageway (5) is opened to turn the gas body in the recovery tank (2) into a gas component. It is fed from the recovery channel (5) to the cooling liquefaction tank (8), where it is cooled to a temperature near the halon solidification temperature to separate it into halon gas components and nitrogen gas components, and liquefy and collect halon gas components. The nitrogen gas component is discharged from the separation gas discharge passage (39).

◎ Fourth recovery procedure The liquefied halon stored in the cooling liquefaction tank (8) is
An electric heater (15) provided in the cooling liquefaction tank (8) with all the electromagnetic flow passage opening / closing valves (9) (12) (44) in the recovery passageway (3) closed by the full signal in 4). Is applied to heat the gas layer portion in the adiabatic storage tank (13) to increase the pressure, and the pressure difference between the pressure in the adiabatic storage tank (13) and the recovery tank (2) has exceeded the set pressure. When the differential pressure switch (21) located in the condensate outlet (20) detects it, the electromagnetic on-off valve (22) located in the condensate outlet (20) is opened and the cryogenic pump (23) is activated. To recover the liquefied halon stored in the adiabatic storage tank (13).
Pump to (2). Then, at this time, the liquid level gauge (34) for detecting the liquid level in the adiabatic storage tank (13) is monitored so that the nitrogen gas does not flow into the recovery tank (2), and a constant amount is maintained in the adiabatic storage tank (13). Close the on-off valve (22) while leaving a sufficient amount of CFC liquid. The low temperature pump (23) may be omitted and the liquefied halon in the adiabatic storage tank (13) may be transferred only by the internal pressure difference between the adiabatic storage tank (13) and the recovery tank (2).

As described above, according to the method of the present invention, almost all halon can be recovered without releasing it to the atmosphere.
Further, since the collected halon gas contains almost no impurities, it is possible to collect highly pure halon.

In the above embodiment, the case of recovering the fluorine-based gas used for extinguishing a fire was described, but it goes without saying that it can be used for recovering the fluorine-based gas used as a cooling refrigerant.

[0024]

According to the present invention, first, the liquid component of the liquefied fluorinated gas is transferred to the recovery tank by its own pressure in the storage container, and then the mixed gas of the gas component and the pressurizing gas is stored in the storage container. By introducing into the cooling liquefaction tank at the internal pressure of and liquefying the cooling, it is separated into a fluorine-based gas and a pressurizing gas,
Liquefaction of the fluorine-based gas, the remaining gas components and the gas for pressurization are introduced into the cooling liquefaction tank by a suction pump to liquefy the cooling to separate the fluorine-based gas and the gas for pressurization and liquefy the fluorine-based gas, Since the fluorine-based gas liquefied in the cooling liquefaction tank is transferred to the recovery tank by raising the temperature of the cooling liquefaction tank, almost all the liquefied fluorine-based gas in the storage container can be recovered in the recovery tank. In addition, since the pressurizing gas in the storage container is separated at the time of cooling and liquefying, the recovered liquefied fluorinated gas can be of high purity so that the pressurizing gas is not mixed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Storage container, 2 ... Recovery tank, 3 ... Recovery path, 4 ... Liquid component recovery path, 5 ... Gas component recovery path, 8 ... Cooling liquefaction tank, 13
... Adiabatic storage tank, 14 ... Heat exchanger, 15 ... Heating means, 31 ... Suction pump, 33 ... Weight detector.

Claims (7)

[Claims] 1. When recovering a liquefied fluorine-based gas and a pressurizing gas stored in a storage container (1), first, most of the liquid component in the storage container (1) is recovered by its own pressure. The first recovery procedure for recovering to (2), and the gas component in the storage container (1) is supplied to the cooling liquefaction tank (8) at the internal pressure in the storage container (1) after the completion of the first recovery procedure. And the gas for pressurization are separated, and the second recovery procedure for liquefying the fluorine-based gas and the gas component remaining in the storage container (1) are sucked by the suction pump (3
It is introduced into the cooling liquefaction tank (8) through (1), and is cooled and liquefied to separate into a fluorine-based gas and a pressurizing gas, and a third recovery procedure for liquefying the fluorine-based gas is also provided. ) Is heated and the liquefied gas of the fluorine-based gas liquefied in the second recovery procedure and the third recovery procedure is recovered in the recovery tank (2).
A method of recovering a fluorine-based gas, which comprises a fourth recovery procedure for recovering a fluorine-based gas. 2. The first recovery procedure is terminated by detecting the weight of the storage container (1) by the weight detector (33) and detecting the predetermined weight by the weight detector (33). Item 1. A method for recovering a fluorine-based gas according to Item 1. 3. The fluorine-based gas recovery method according to claim 1, wherein the cooling liquefaction tank (8) is lowered to a temperature near the solidification temperature of the fluorine-based gas. 4. The vaporized gas discharged from the upper part of the recovery tank (2) is returned to the inlet of the cooling liquefaction tank (8) to separate the pressurizing gas mixed in the recovered fluorine-based gas and The method for recovering a fluorine-based gas according to claim 1, wherein the system-based gas is reliquefied. 5. A recovery path (3) connected to a storage container (1) for storing a liquefied fluorine-based gas is connected to a recovery tank (2), and the recovery path (3) is a liquid component recovery path (4). ) And the gas component recovery path (5) are arranged in parallel to form a gas component recovery path (5).
A fluorine-based gas recovery apparatus in which a cooling liquefaction tank (8) is attached to the cooling liquefaction tank (8) and a heating means (15) is arranged in the cooling liquefaction tank (8). 6. The fluorine-based gas recovery apparatus according to claim 5, wherein the storage container (1) is mounted on the weight detector (33). 7. The apparatus for recovering a fluorine-based gas according to claim 5, wherein the cooling liquefaction tank (8) is constituted by a heat exchanger (14) for liquid nitrogen and an adiabatic storage tank (13).