JPH02195190A - Gas recovery method and recovery device - Google Patents

Abstract

PURPOSE:To need no worrisom maintenance and recover a gas by cooling the gas containing plural kinds of mixed gases down to a freezing point or less with the use of a refrigerating device to solidify so as to catch and heating the solidified gas to liquidize so ass to recover. CONSTITUTION:A gas containing fleon gas and the like is dehumidified by a dehumidifier 4 to enter a housing 1 to cool with the use of a refrigerating device 2 down to a freezing point or less to solidify so as to adhere to the refrigerating device 2. A quantity of adhesion increases with the time elapsed and cooling is stopped when the quantity is a proper one. Next, it is heated up to the freezing point of the gas with the use of a heater 3, it is liquidized to drip in the refrigerating device 2 so as to recover since it drops on the bottom of the housing 1. A fleon-lost gas is heated by a heater 5 to be nearly equal to the atmospheric temperature so as to release in the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention is a method for separating and recovering various solvent gases or other gases, especially chlorofluorocarbon gases, mixed with gases such as air, from the above-mentioned mixed gases, etc. The present invention relates to a collection method and a collection device.

2. Description of the Related Art Conventionally, this type of technology is well known and is not shown in the drawings; however, a case will be described in which, for example, Freon R113 gas (including mist, etc.; in this invention, gas includes mist, etc.) is recovered as a fluorocarbon gas. In general, the fluorocarbon gas that comes from the product outlet of cleaning equipment for various industrial products that uses Freon R113 as a cleaning liquid is usually mixed with air at a concentration of several thousand P, P, M. The target gas, such as chlorofluorocarbon gas, is usually adsorbed using activated carbon, concentrated through this adsorption, and then water vapor is applied to the activated carbon and heated to desorb the adsorbed fluorocarbon gas. The chlorofluorocarbon gas mixed with water vapor is cooled to about -4°C and liquefied. In this case, the water vapor is Freon R1
Although it floats as ice on top of fluorocarbon R113, it can be separated based on its specific gravity, and thus Freon R113 can be recovered.

Problems to be Solved by the Invention However, since the above-mentioned conventional technology uses activated carbon, this activated carbon becomes fatigued and often needs to be replaced. That is, maintenance is troublesome.

This invention was made to solve the above-mentioned problems, and its purpose is to provide a gas recovery method and a gas recovery device that do not require troublesome maintenance unlike the above-mentioned conventional techniques. .

Another object of the present invention is to provide a method and apparatus for recovering fluorocarbon gas.

Means for Solving the Problems This invention achieves the above objects. First, the method is described. It involves cooling a mixture of multiple types of gas to below the freezing point of the target gas using a refrigeration device. This is a gas recovery method in which the target gas is solidified and captured, and then the solidified gas is heated to liquefy and recovered. Moreover, the target gas is a method for recovering the above gas, which is chlorofluorocarbon gas.

Next, the device includes a refrigeration device 2 that is provided in a housing 1 that contains a mixture of multiple types of gas and that cools the target gas to below the freezing point of the gas; This is a gas recovery device comprising a heating device 3 that heats the solidified gas to liquefy it.

The refrigeration device 2 is a recovery device for the gas that also serves as a heating device 3, and the housing 1 is a recovery device for the gas connected to the dehumidifier 4 that dehumidifies the gas. This is the gas recovery device connected to the heater 5 that heats the gas that has lost the gas and releases it to the outside, and the gas is also a fluorocarbon gas recovery device.

Function A gas mixture of gases such as fluorocarbon gas is dehumidified by the dehumidifier 4, enters the housing 1, is cooled by the refrigeration device 2 to below the freezing point of the target gas, for example fluorocarbon gas, and is solidified. The amount of this adhesion increases with the passage of time, and when an appropriate amount is reached, the cooling is stopped, and then the gas is heated by the heating device 3 to a temperature above the freezing point of the gas. It liquefies, drips from the freezing device 2, flows down to the bottom of the housing 1, and is collected.

Then, the gas that has lost the target gas is heated by the heater 5, brought to approximately the atmospheric temperature, and then released into the atmosphere.

Embodiment In FIG. 1, a housing 1 is made of a heat insulating material, and a refrigeration device 2 is provided therein. The refrigeration system 2 includes, for example, a refrigeration machine 7 and a flexible pipe 9 having fins 8 communicated with the refrigeration machine 7. The freezing device 2 is also formed as a heating device 3.

Generally, a refrigerator radiates heat during its operation, and by supplying this heat to the flexible pipe 9, the refrigeration device 2 can be converted into a heating device 3. To explain this, FIG. 2 shows a heating device that also serves as a refrigeration device used in this invention.
In the figure, 10 is a compressor, 1! is an accumulator. Further, 12 is an evaporator, 13 is a capillary tube, 14 is a dryer, 15 is a check valve, 16 is a condenser, 17 is a four-way valve, and 18 is a fan. These are connected by a pipe 19. and compressor 1
When the four-way valve 17 and the evaporator 12 operate as a refrigeration system, a passage is formed in the four-way valve 17 as shown by the solid line, so that the refrigerant advances as shown by the arrow A and is cooled in the evaporator 12. Also in this case capacitor 1
Next, when the four-way valve 17 forms a passage as shown by the dotted line, the refrigerant advances as shown by arrow B, cooling occurs in the condenser 16, and heat is radiated in the evaporator 12. . As a result, the evaporator 12 and the compressor 10 serve as a heating device. It will be understood that the evaporator 12 and compressor 10 can thus operate as a refrigeration device or as a heating device by switching the four-way valve 17.

In this way, switching between freezing and heating can be performed simply by operating the valve.Next 4 is a dehumidifying device, which is provided with a flexible pipe 9 having fins 8 connected to a dehumidifying refrigerator 20. There is. Further, 5 is a heater, which is connected to the downstream side of the housing 1 by a connecting pipe 21, and it is most preferable that the heater 5 uses the condenser 16. It uses heat dissipation during operation.

Next, 22 is a gas inlet of the housing 1, which is connected to a cleaning machine (not shown) using, for example, Freon 113.
From this population of 22, - for example, several thousand P of Freon R113.
, P, and M are supplied. 23 is a filter, 24 is a gas passage, and 25 is a water recovery tank, which collects water dripping from the dehumidifier 4.

Further, in FIG. 1, 26 and 27 are dampers, 28 is a blocking wall, 29 is a flow passage formed at 3° at the bottom of the housing 1,
31 is a solvent recovery $1, 32 is a water tank, and 33.34 is a valve.

Note that 35 is a precooling device, which is formed into a coil shape, for example, and is cooled by the cold air provided by the refrigeration device 2, so that the gas passing through it can be precooled to, for example, about 10°C. It has become. 36 is a fan, and 37 is a gas outlet formed in the precooling device 35.

As an example, Freon R113 is 7.7 as shown in Figure 3.
74 Air containing P, P, and M is supplied from the inlet 22, and the dehumidifier connected to the dehumidifying refrigerator 20 is maintained at 4°C, for example, to remove about 80% of the moisture, and then It is cooled to about -10° C. in the pre-cooling device 35 and supplied to the fins 8 of the refrigeration device 2 by the fan 36. The corrugated pipe 9 and the fins 8 are cooled to -60° C. below -37°C, which is the freezing point of Freon R113, by the refrigerator 7.
C. to -80.degree. C., and therefore the gas of the Freon R113 solidifies and adheres to the corrugated tube 9, the fins 8, etc. This amount of adhesion increases over time. During this time, dampers 26 and 27 are closed.
When the device is operated in this way - for example the third
The results shown in the figure were obtained. That is, if the temperature of the refrigeration equipment 2 is -80°C, the Freon R113 which was 7.774 P, P, M at the inlet 22 will be at the outlet 3.
The gas concentration in 6 was only 9 P, P, M. Note that the air that has lost the Freon R113 gas in this manner is heated by the heater 5 and is discharged to the outside as clean air at approximately room temperature. And recovery 4! Freon R1 recovered on 31st
13 is again sent to a cleaning tank (not shown) and reused.

Next, FIG. 4 shows a second embodiment of the present invention, in which a plurality of refrigeration devices are provided, and while one refrigeration device is in the process of cooling, the other refrigeration device is in the process of heating. It is designed so that it can be operated in sequence, and in this way it can be operated continuously. As shown by the solid arrow C in the figure, a mixed gas (for example, air mixed with Freon R113) is supplied to the refrigeration device 2a to solidify it. In this case, dampers 39 and 40
, 41 are open, and dampers 42, 43 and 44 are closed. Then, after a certain period of time has passed, the freezing device 2a
If sufficient adhesion has been achieved, the dampers 39, 40.
41 is closed, the gas is supplied in the direction of the dotted arrow d, and is cooled by the refrigeration device 2. Meanwhile, the refrigeration device 2 switches the valve as described above, turns it into a heating device, raises the temperature, and solidifies the gas - for example, Freon R.
113 is liquefied and collected by flowing down. By repeating this operation, it can be operated continuously.

Another problem is that in the conventional method using activated carbon, it is difficult to recover the alcohol content in Freon R113 and the like used as a cleaning agent. Since the alcohol is desorbed using water vapor as described above, the alcohol dissolves in the water vapor and evaporates together with the water vapor. Therefore, the recovered liquid cannot be used as it is as a cleaning liquid. However, the alcohol and other surfactants recovered by this invention can be recovered as they are, and therefore can be used as a cleaning solution immediately.

It goes without saying that the method and apparatus of the present invention can be used not only for the above-mentioned Freon R113 but also for carbon dioxide and other general gases.

Effects of the Invention This invention is constructed as described above, and uses a refrigeration device to cool a mixture of multiple types of gas to below the freezing point of the target gas, solidify it and capture it, and then heat it. Since the gas is liquefied and recovered, it is not necessary to use activated carbon as described in the conventional example, and therefore it is possible to provide a gas recovery method that is extremely easy to maintain. Furthermore, if the gas is fluorocarbon gas, it is possible to provide a method for recovering fluorocarbon gas that is extremely easy to maintain. Furthermore, it is possible to provide a gas and fluorocarbon gas recovery device that is extremely easy to maintain. Furthermore, the apparatus can be simplified by having the refrigeration apparatus 2 also serve as the heating apparatus 3. Furthermore, when the dehumidifier 4 is connected to the housing l, gas and fluorocarbon gas can be recovered as efficiently as dehumidified. In addition, when the heater 5 is connected to the housing 1, the gas that has lost the target gas can be discharged to the outside at almost room temperature.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention. Figure 1 is a cross-sectional view schematically showing a gas recovery device, and Figure N2 is a circuit diagram of a refrigeration device that also serves as a heating device. , FIG. 3 is a graph showing the results of recovery of Freon R113 obtained by the apparatus shown in FIG. 1, and FIG. 4 is a diagram schematically showing a gas recovery apparatus showing a second embodiment of the present invention. . 1... Housing 2... Refrigeration device 3... Heating device 4... Dehumidifying device 5... Heater Fig. 1 Fig. 2 B Fig. 3 Temperature--

Claims (1)

[Claims] 1. A gas mixture of multiple types of gas is transferred to a refrigeration device (2).
A method for recovering a gas, in which the target gas is cooled to below the freezing point of the target gas, solidified and captured, and then the solidified gas is heated and liquefied to be recovered. 2. The method for recovering gas according to claim 1, wherein the target gas is chlorofluorocarbon gas. 3. A refrigeration device (2) provided in a housing (1) that accommodates a mixture of multiple types of gas and that cools a target gas to a temperature below the freezing point of the gas;
) A gas recovery device comprising a heating device (3) that heats and liquefies the gas that has been cooled and solidified. 4.Claim 3, wherein the freezing device (2) also serves as the heating device (3).
Recovery device for the gas described. 5. Claim 2, 3, or 4, wherein the housing (1) is connected to a dehumidifier (4) that dehumidifies the mixed gas.
Recovery device for the gas described. 6. The gas recovery device according to claim 3, 4, or 5, wherein the housing (1) is connected to a heater (5) that heats the gas that has lost the target gas and releases it to the outside. 7. Claims 3 and 4, wherein the target gas is chlorofluorocarbon gas.
5. The gas recovery device according to 5 or 6.