JPS58108496A - Method and device for radioactive rare gas - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radioactive rare gas separation/recovery method and apparatus, and in particular to a radioactive rare gas separation/recovery method and apparatus suitable for removing decay heat generated during xenon adsorption/decay. This is part 4 regarding equipment.

Conventional radioactive rare gas separation/recovery methods and equipment examples are presented in Part 1.
This will be explained with the help of a diagram. Figure 1 is a flow sheet of a radioactive rare gas separation/recovery process that combines activated carbon adsorption method and cryogenic separation method in series. In Figure 1, l indicates a plurality of room-temperature activated carbon adsorption towers (hereinafter referred to as room-temperature adsorption towers) installed in series. A conduit 2 for supplying processing gas (coolant cover gas - argon) is connected. Reference numeral 3 designates two dehydration towers installed in parallel; the bottoms of the three dehydration towers are each connected to the bottom of the cold-temperature adsorption tower 1 through a conduit 4, and the top of the three dehydration towers is connected to a pipe 4 for supplying regeneration gas. A conduit 5 is connected to the bottom side of the tower, and a regenerated gas discharge conduit 6 is connected to the bottom side of the column. 7 is a precooler; precooler 7
The top portion is connected to the dehydration tower 3 through conduits 8, respectively. 9
There is an evaporator at the bottom 10. The distillation column 9 has a condenser (1) at the top, and the distillation column 9 is connected to the bottom of the pre-cooled ls7 by a conduit, and the evaporator 10 is connected to a conduit 13 for sending out condensate.

14 is a liquid nitrogen trim; a conduit 15 for supplying liquid nitrogen is connected to the liquid nitrogen drum 14; a conduit 16 for supplying liquid nitrogen to the condenser 11; and a conduit 17 for supplying nitrogen gas to the condenser 11. Further, the liquid nitrogen drum 14 and the precooler 7 are connected through a conduit 181. Note that a conduit 19 for discharging nitrogen gas is connected to the precooler 7. Shu is a low-temperature activated carbon adsorption tower (hereinafter abbreviated as low-temperature adsorption tower).
The bottom of the low-temperature adsorption column is connected to the top of a distillation column 9 through a conduit 4. n is a purified gas heater, and the intake side of the purified gas heater 4 is connected to the top of the low-temperature adsorption tower by a conduit n, and the outlet side of the purified gas heater ρ is connected to a conduit for sending purified gas. ing. Reference numeral 5 denotes a 7 Leon refrigerator, in which a conduit device for supplying cooling water and a conduit n for discharging cooling water are respectively connected to a room temperature adsorption tower l. In addition, in order to prevent heat from entering from the outside, a precooler 7. Distillation column9. The liquid nitrogen drum 14 and the low-temperature adsorption tower I are housed in a refrigerated analyzer. In the radioactive rare gas separation/recovery process configured as described above, the radioactive rare gases such as krypton and xenon contained in the process gas from the reactor main body are separated and recovered as follows.

Processed gas from the reactor main body passes through conduit 2 to room-temperature adsorption tower l.
will be sent to In the room-temperature adsorption tower 1, the xenon in the treated gas generates decay heat during adsorption and decay, increasing the temperature of the room-temperature adsorption tower 1 and reducing the adsorption effect of activated carbon. Chilled water is supplied to the room-temperature adsorption tower 1 through a conduit, and the cold water that has absorbed the decay heat is returned to the Freon refrigerator 2 through a conduit 4, thereby removing the decay heat. The processing gas from which xenon has been separated is supplied to the dehydrator 43 via conduit 4, and after moisture is removed, it is pre-cooled via conduit 8! 7. Note that the dehydration tower 3 is switched to another adsorption tower 3 before reaching the breakthrough point after water removal,
The moisture absorbent in the dehydration tower 3 is supplied to the dehydration tower 3 via a conduit 5 and is regenerated by regeneration gas discharged through a conduit 6.

The process gas dehydrated in the dehydration tower 3 supplied to the precooler 7 is cooled to near the boiling point of nitrogen by nitrogen gas separately supplied from the liquid nitrogen drum 14 to the precooler 7 via the conduit 18, and then passed through the conduit ν. It is supplied to the distillation column 9 through. In the distillation column 9, the treated gas rises together with the evaporated gas from the evaporator 10,
In the condenser 11, a part of the processing gas is brought into gas-liquid contact with the liquefied descending liquid through the packed bed by liquid nitrogen separately supplied from the liquid nitrogen drum 14 through the conduit 16. Krypton, which is a high boiling point component, moves to the liquid side, and the condensate containing a large amount of krypton remains in the evaporator lO.
It is retained and sent out of the system through conduit 13. On the other hand, the processed gas from which most of the krypton has been separated and purified is passed through the condenser 11, from the top of the distillation column 9, through the conduit 4, and then to the low-temperature adsorption system installed in consideration of the case where the distillation column 9 does not operate normally. The purified gas is passed through the tower and supplied to the purified gas heater 1!22 through the conduit, and after being returned to room temperature in the purified gas heater 4, it is sent to the conduit.
Sent outside the system.

In this way, in the conventional radioactive rare gas separation φ recovery method and device, the purified gas is simply returned to room temperature in the purified gas heater 4 and removed from the system without using the cold heat of the purified and low-temperature processing gas. On the other hand, there was a drawback that a separate Freon refrigerator 3 was installed to remove the decay heat generated during adsorption and attenuation of xenon in the ζ room-temperature adsorption tower 1, which resulted in a large waste of energy.

The present invention aims to eliminate the above-mentioned drawbacks, and utilizes the cooling heat of the purified and low-temperature processing gas to eliminate the decay heat generated during the adsorption and decay of xenon without using a 7 Leon refrigerator. The present invention provides a method and apparatus for separating and recovering radioactive rare gases.

An embodiment of the present invention will be explained with reference to two diagrams. In Figure 2,
The same equipment as in FIG. 1 is denoted by the same reference numerals and the explanation thereof will be omitted.

4 is a conduit which is branched from the conduit and has an automatic valve installed in the middle, and is connected to each of the normal temperature adsorption towers 1. The pipes are the pipes connecting the pipes and each cold adsorption tower. The proverb is a temperature indicating adjustment needle installed in the middle of the conduit 4 and adjusting and controlling the valve opening degree of the automatic valve (equipment).

In this case, the decay heat generated during the adsorption and decay of xenon in the process gas from the reactor main body, which is supplied to the room-temperature adsorption tower l via conduit 2, is transferred to the low-temperature adsorption tower through conduit n and automatic valve addition. Purified water is supplied to the cold adsorption tower l via conduit 4,
In addition, it is removed using the cold heat of the low-temperature processing gas. In this case, in order to prevent water contained in the treated gas from the reactor main body from freezing due to the purified and low-temperature treated gas, and from deteriorating the adsorption function of the room-temperature adsorption tower, The amount of treated gas supplied to the normal temperature adsorption tower 1 that has been purified by setting the temperature as low as possible so that the water contained in the treated gas from the reactor main body does not freeze at n is as follows: Adjust the valve opening of the automatic valve blade.
controlled and controlled to an appropriate amount. Thereafter, krypton is separated from the processing gas from which xenon has been separated in the same process as in the conventional example, and a part of the processing gas that has become low temperature is used to remove the decay heat generated when xenon is adsorbed and attenuated. The residue is returned to room temperature by the purified gas heater 4, and is sent out of the system through the conduit 31 together with the processing gas used to remove decay heat from the conduit 31.

In addition, the purified gas heater n is used as a heat exchanger, and another refrigerant is provided between the room-temperature adsorption tower 1 and the purified gas heater n, so that the treated gas that has been purified and has become low temperature can be adsorbed at room temperature. If the decay heat generated when xenon is adsorbed and attenuated in the tower is removed using the cold heat of the purified and low-temperature treated gas, there is no need to install a 7 Leon refrigerator, so energy is wasted. This can be significantly reduced.

As explained above, the present invention is designed to purify the decay heat generated during the adsorption and decay of xenon in order to separate and recover radioactive rare gases such as krypton and xenon contained in the processing gas from the reactor main body. Since the cold heat of the processing gas that has been heated and has become low temperature is removed in a separate layer, there is an effect that the waste of cyene energy that is not required by the Freon refrigerator can be significantly reduced.

[Brief explanation of the drawing]

Figure 1 shows the 7th stage of the radioactive rare gas separation/recovery process, which explains the conventional radioactive rare gas separation/recovery method and equipment example.
0-Sheet, FIG. 2 is a flow sheet of a radioactive rare gas separation/recovery process illustrating one embodiment of the present invention. 1...Normal temperature adsorption tower, 2. 4.23.24.2
9.31...Conduit, Addition...Low temperature adsorption tower, (Equipment)...Automatic valve,!・・・・・・Temperature indicating controller procedural amendment (0 quotation Name of invention Person who amends radioactive rare gas separation/recovery method and equipment, p., LSI 01 Todo Co., Ltd. Representative Name 3-1) Shigeyo Katsu (Representative) Claims column and Detailed Description of Invention column of the specification subject to personal amendment Contents of the amendment As shown in the appendix Name of the invention in the description Method for separating and recovering radioactive rare gases and Apparatus Claims In the separation and recovery method, the decay heat generated during adsorption and attenuation of the xenon is removed by using the cold heat of the purified and low-temperature processing gas. A method for separating and recovering radioactive rare gases. 2. Combining activated carbon adsorption method and cryogenic separation method, room temperature"41
In a separation/recovery device for radioactive rare gas contained in a process gas, which is composed of a dehydration tower, a low-temperature adsorption tower, a purified gas heater, etc., , and a conduit with an automatic valve installed in the middle is connected to the room-temperature adsorption tower, and an automatic valve opening degree adjustment /
Radioactive rare gas separation/recovery bag W0 characterized by installing a temperature indicating controller for control -Relates to a radioactive rare gas separation/recovery method and device suitable for removing decay heat generated during decay. Conventional radioactive rare gas separation/recovery method and device example No. 1
This will be explained using figures. FIG. 1 is a flow sheet of a radioactive rare gas separation/recovery process that combines an activated carbon adsorption method and a cryogenic separation method in series. In Fig. 1, reference numeral 1 indicates a plurality of cold adsorption towers installed in series, and the bottom of the last cold adsorption tower 1 is connected to a conduit 2 for supplying processing gas containing radioactive rare gas. . 3 is two dehydration towers installed in parallel.
The bottoms of the dehydration towers 3 are each connected to the bottom of the room-temperature adsorption tower 1 at the front by a conduit 4, and the top side of the dehydration tower 3 has a conduit 5 for supplying regenerated gas, and the bottom side has a conduit 5 for regenerating gas discharge. A conduit 6 is connected thereto. 7 is a precooler, and the top of the precooler 7 is a dehydration tower 3
and are connected by conduits 8, respectively. 9 is an evaporator at the bottom 10. The distillation column has a condenser 11 at the top, and the distillation column 9 is connected to the bottom of the precooler 7 by a conduit 12, and the evaporator IO is connected to a conduit 13 for sending out condensate. Reference numeral 14 denotes a liquid nitrogen drum. A conduit 15 for supplying liquid nitrogen is connected to the liquid nitrogen drum 14, and a conduit 16 for supplying liquid nitrogen to the condenser 11 and a conduit 17 for supplying nitrogen gas from the condenser 11 are connected. Further, the liquid nitrogen drum 14 and the precooler 7 are connected by a conduit 1B. Note that a conduit 19 for discharging nitrogen gas is connected to the precooler 7. I is a low-temperature adsorption tower, the bottom of the low-temperature adsorption tower (9) is connected to the top of distillation tower 9 and conduit 2.
They are connected by 1. n is a purified gas heater, the inlet side of the purified gas heater n is connected to the top of the low-temperature adsorption tower by a conduit n, and the outlet side of the purified gas heater n is connected to a conduit for sending purified gas. ing. Reference numeral 5 denotes a refrigerator, and a conduit for supplying cooling water and a conduit n for discharging cooling water are respectively connected to the normal temperature adsorption tower l. In addition, in order to prevent heat from entering from the outside, a precooler 7. Distillation column9. The liquid nitrogen drum 14 and the low-temperature adsorption tower are housed in a refrigerated chamber. In the radioactive rare gas separation/recovery process configured as described above, the radioactive rare gas contained in the process gas is separated and recovered as follows. The process gas containing the radioactive rare gas is fed to the cold adsorption tower 1 via the conduit 2. In the room temperature adsorption tower 1, the xenon in the treated gas generates decay heat during adsorption and decay, and the room temperature adsorption tower 1
To prevent this, cold water is supplied from the refrigerator 3 to the room-temperature adsorption tower 1 through a conduit, and the cold water that has absorbed this decay heat is passed through the conduit n.
The decay heat is removed by returning it to the refrigerator. The treated gas from which xenon has been separated is passed through conduit 4 to dehydration tower 3.
After moisture is removed, the water is fed through a conduit 8 to a precooler 7. Note that the dehydration tower 3 is switched to another adsorption tower 3 after water removal and before reaching the breakthrough point, and the hygroscopic agent in the dehydration tower 3 is supplied to the dehydration tower 3 via the conduit 5 and discharged from the conduit 6. - Regenerated by raw gas. The processing gas dehydrated in the dehydration tower 3 supplied to the precooler 7 is cooled to near the boiling point of nitrogen by nitrogen gas separately supplied to the precooler 7 from the liquid nitrogen drum 14 via the conduit 1B, and then is cooled to near the boiling point of nitrogen through the conduit 12. Distillation column 9
supplied to In the distillation column 9, the treated gas rises together with the evaporated gas from the evaporator IO, and in the condenser 11, a part of the treated gas is liquefied by liquid nitrogen separately supplied from the liquid nitrogen drum 14 through the conduit 16, and a descending liquid is produced. By contacting gas and liquid through the packed bed, krypton, which is a high boiling point component in the processing gas, moves to the source side, and the condensate containing a large amount of krypton stays in the evaporator 10 and is sent out of the system through the conduit 13. be done. On the other hand, the treated gas from which most of the krypton has been separated and purified passes through the condenser 11, from the top of the distillation column 9, through the conduit 21, through the low temperature adsorption column, and is supplied to the purified gas heater 4 via the conduit n. , after being returned to room temperature in a purified gas heater n, it is sent out of the yarn through a conduit U. In this way, conventional radioactive rare gas separation and recovery methods and devices do not utilize the cold energy of the purified and low-temperature processing gas, but instead simply return it to room temperature using a purified gas heater and remove it from the system. On the other hand, in order to remove the decay heat generated when xenon is adsorbed and attenuated in the room-temperature adsorption tower 1, it was necessary to separately install a cooling device such as a refrigerator δ. The purpose of the present invention is to save energy without using a cooling device such as the above-mentioned refrigerator, and the decay heat generated when the xenon adsorption φ is attenuated can be converted into purified and low-temperature processed gas without using a refrigerator. The purpose of this invention is to provide a method and device for separating and recovering radioactive rare gas, which removes it using the cold energy of the gas. An embodiment of the present invention will be described with reference to FIG. In Figure 2,
The same equipment as in the IJi diagram is indicated by the same reference numerals, and the explanation thereof will be omitted. The vessels are connected to the respective normal temperature adsorption towers 1 through conduits which are branched from the conduit and have an automatic valve I installed in the middle. Reference numeral 31 denotes a conduit connecting the conduit device to each cold adsorption tower 1. The proverb is a temperature indicating controller that is installed in the middle of the conduit 4 and adjusts and controls the valve opening degree of the automatic valve chrysanthemum. In this case, the decay heat generated during the adsorption and decay of xenon in the process gas supplied to the room-temperature adsorption tower 1 via the conduit 2 is
The gas is piped from the low-temperature adsorption tower, and is supplied to the room-temperature adsorption tower 1 through an automatic valve (equipment) and a conduit, where it is purified and removed using the cold heat of the low-temperature treated gas. In this case, purified and. Due to the low temperature processing gas! In order to prevent the moisture contained in the treated gas from freezing and the adsorption function of the room-temperature adsorption tower l being reduced, the temperature indicator is set to a temperature as low as possible to prevent the moisture contained in the treated gas from freezing. The supply amount of the treated gas, which has been purified by setting the temperature to
Controlled to an appropriate amount. After that, from the processing gas from which xenon has been separated, krypton is separated in the same process as in the conventional example, and a part of the processing gas that has become low temperature is used to remove the decay heat generated when xenon is adsorbed and attenuated. The remaining gas is returned to room temperature by the purified gas heater 2, and is sent out of the system from the conduit device together with the processing gas used to remove decay heat from the conduit 31. In addition, the purified gas heater n is used as a heat exchanger, another refrigerant is provided between the room temperature adsorption tower town and the purified gas heater n, and the refrigerant is cooled by the purified and low-temperature treated gas, This may remove the decay heat generated when xenon adsorption 9 decays. In this way, if the decay heat generated when the xenon adsorption decays in the room-temperature adsorption tower is removed using the cold heat of the purified and low-temperature process gas, the installation of a refrigerator becomes unnecessary. As explained above, the present invention is particularly useful for separating and recovering radioactive rare gases contained in a process gas, and in particular, the decay heat generated during adsorption and decay of xenon is purified by 1°, and Since the processing gas, which has now reached a low temperature, is removed by cooling and heating, a refrigerator is not required. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a flow sheet of a conventional radioactive rare gas separation/recovery method and device, and Fig. 2 shows an example of the radioactive rare gas separation/recovery process. This is a flow sheet of the radioactive rare gas separation/recovery process to be explained. 1...Normal temperature adsorption tower, 2. 4.23.24.2
9.31...conduit, addition...low-temperature adsorption tower, (equity)...automatic valve, proverb...temperature indicating and regulating needle agent - patent attorney Usui 1) Tori Tori Kai °1 [Indication of 1981 Patent Application No. 113685 Title of invention Radioactive rare gas separation/recovery method and device Manufacturer I/Omote old ball 11 wins
Osamu Shigeyo Contents of amendments as per the attached sheet /go=)1
The content column of the amendment in the procedural amendment submitted dated October 21, 1980 is amended to read as [as attached (there is no historical fact in the content other than the matters stated in the subject of amendment column)].

Claims (1)

[Claims] 1. Separation of radioactive rare gases by combining activated carbon adsorption method and cryogenic separation method to separate and recover radioactive rare gases such as krigton and xenon contained in treated gas from the reactor main body.・Recovery method. In an apparatus for separating and recovering radioactive noble gases such as krypton and xenon contained in the treated gas from the reactor main body, which is composed of a carbon adsorption tower, a dehydration tower, a low-temperature activated carbon adsorption tower, a purified gas heater, etc. A conduit branched from a conduit connecting the low temperature activated carbon adsorption tower and the purified gas heater and having an automatic valve installed in the middle is connected to the room temperature activated carbon adsorption tower, and the room temperature activated carbon adsorption tower and the dehydration tower are connected to each other. A radioactive rare gas separation/recovery device characterized in that a temperature indicating adjustment needle for automatic valve opening adjustment and control is installed in the middle of the connecting conduit.