JP2003066191A - Processing method for radioactive gas and filter device for adsorbing radioactive gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drastically reduce the weight of a device trapping and removing radioactive gas and easily process the device trapping and removing radioactive gas even for an existing air purifier by attaching the device to the air purifier ward. SOLUTION: In a filter device 14 for adsorbing radioactive gas which is put in a gas processing path of an air conditioning equipment, a charcoal filter 13 of activated carbon sheet is contained. Trapping and removing of radioactive gas are attained by passing the gas to the sheet charcoal filter 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radioactive gas treatment method for collecting and removing radioactive gas generated in medical facilities, nuclear facilities, etc., and a filter device for adsorbing radioactive gas.

[0002]

2. Description of the Related Art Conventionally, in medical facilities and nuclear facilities where radioactive gas is generated, it is necessary to collect and remove the generated radioactive gas and then discharge it outside the facility. For example,
As shown in FIG. 8, since radioactive iodine and the like are discharged as radioactive gas in RI research and experiment facilities, etc., an air purifying device 3 is installed in a gas treatment path 2 of an air conditioning facility 1, and standards regulated by law are set. The radioactive gas concentration is reduced below the specified value to ensure safety before it is discharged outside the facility.

As shown in FIG. 9, the air purifying device 3 includes a pre-filter 4 for removing relatively large coarse dust, and a high performance filter (HE) for higher dust removing action.
PA filter 5 and a charcoal filter 6 for collecting and removing radioactive gas. However, in a facility where the generation of radioactive gas is not so high, as shown in FIG. 10, when an air purifying device including a pre-filter 4 and a high-performance filter 5 is used without the charcoal filter 6. There are many.
The pre-filter 4, the high-performance filter 5, the charcoal filter 6, etc. are each the open / close key 3 of the air purification device 3.
It is housed in each housing having a, 4a, 5a so that it can be freely taken in and out (see FIG. 12).

[0004]

By the way, in recent years, due to the increasing use of nuclear technology, the amount of radioactive gas discharged from university research facilities, medical facilities, nuclear power plants, etc. is also increasing, and the environment is also increasing. Due to consideration of the situation, the regulation of the concentration of radioactive gas discharged into the atmosphere has been set more strictly. Therefore, the installed air purifying device has been reviewed.

Further, as shown in FIG. 11, the charcoal filter 6 in the filter device 7 for adsorbing the radioactive gas, which is replaceably inserted in the air purifying device 3, has a powder for collecting and removing the radioactive gas component. Or granular activated carbon 6a
Is used. Therefore, a large number of fine holes (not shown)
The filter housing 6b is formed by a metal plate or the like in which the charcoal filter 6 is filled with powdery or granular activated carbon 6a, and the charcoal filter 6 is folded back in a wavy or Z-shape. In this state, it is supported by the outer frame of the housing 7a.

For this reason, the charcoal filter 6 itself becomes a heavy object, but the housing 7a for supporting the charcoal filter 6 is also required to have a rigidity capable of supporting the weight of the charcoal filter 6, and therefore is formed of a thick iron plate or the like, which is inevitable. In addition, the filter device 7 for adsorbing radioactive gas has a heavy weight as a whole, and there are drawbacks such as time-consuming work for filter replacement, poor handleability, and high cost.

On the other hand, in a facility or the like where removal of radioactive substances by the high-performance filter 5 is sufficient, high-performance filters are used when the concentration of radioactive gas discharged into the atmosphere is strictly regulated. An air purification device having a charcoal filter 6 for collecting and removing a radioactive gas is required in the subsequent stage of 5, but the existing air purification device without the charcoal filter 6 is replaced with a new air having the charcoal filter 6. When replacing with a purification device, the cost burden becomes large.

The present invention has been made in view of the above circumstances. An object of the present invention is to reduce the weight of a device for collecting and removing radioactive gas, and to purify existing air. An object of the present invention is to provide a method for treating a radioactive gas, in which a device for collecting and removing a radioactive gas component can be easily attached afterwards to the device, and a filter device for adsorbing a radioactive gas.

[0009]

According to the present invention, in order to defeat the above-mentioned object, a method of treating radioactive gas is provided in a gas treatment path of an air conditioning facility as described in claim 1. The filter device for adsorption of radioactive gas is
It is characterized in that it incorporates an activated carbonized charcoal filter in the form of sheets, and collects and removes radioactive gas by passing through the charcoal filter in the form of sheets.
Further, as described in claim 2, the filter device for adsorbing radioactive gas, which has a charcoal filter in the form of activated carbon and has a built-in charcoal filter, is a radioactive gas in an existing air purification device interposed in a gas treatment path of an air conditioning facility. The present invention is characterized in that it is formed so as to be replaceable with the adsorption filter device, and that the radioactive carbon component is collected and removed by the activated carbonized sheet charcoal filter in the existing air purifier. Further, as described in claim 3, in the filter device for adsorbing radioactive gas, which incorporates the activated carbonized sheet-like charcoal filter, an engaging portion that is movably latched in the existing air purification device is provided. The present invention is characterized in that the above-mentioned filter device for adsorbing radioactive gas can be retrofitted to an existing air purifying device, and the sheet-like charcoal filter activated carbonized in the existing air purifying device is used for collecting and removing. . Further, as described in claim 4, it is characterized in that it has a non-woven fabric shape, a honeycomb shape, a paper shape, or the like.

As the radioactive gas adsorption filter device, as described in claim 5, in the air purifying device interposed in the gas treatment path of the air conditioning facility, it is replaceably inserted into the air purifying device. As for the filter device for adsorption of radioactive gas, a charcoal filter in the form of activated carbon is stretched inside a lightweight housing such as wood, and the radioactive gas is collected and removed by passing through this charcoal filter in the form of sheet. It is characterized by Further, as described in claim 6, the filter device for adsorbing radioactive gas, which incorporates a charcoal filter in the form of activated carbon, is a radioactive gas of an existing air purification device interposed in a gas treatment path of an air conditioning facility. The present invention is characterized in that it is replaceable with the adsorption filter device, and enables the collection and removal of the radioactive gas component by the activated carbonized sheet-like charcoal filter in the existing air purification device. Further, as described in claim 7, in the filter device for adsorbing radioactive gas, which incorporates the activated carbonized sheet-like charcoal filter, there is provided an engaging portion which can be retracted in the existing air purifying device. It is possible to retrofit the above-mentioned filter device for adsorbing radioactive gas to the existing air purification device, and it is possible to collect and remove the radioactive gas component by the activated charcoal sheet charcoal filter in the existing air purification device. It is characterized by doing. Further, as described in claim 8, the activated charcoal sheet charcoal filter is woven cloth, non-woven cloth, honeycomb, paper or the like.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an explanatory view showing a method for treating a radioactive gas according to the present invention, and FIG. 2 is an explanatory view showing an example of a filter device for adsorbing a radioactive gas according to the present invention.

As shown in FIG. 1, an air purifying apparatus 10 according to the present invention includes a pre-filter 11 for removing relatively large coarse dust, and a high-performance filter arranged in the subsequent stage for achieving a higher dust removing action ( HEPA filter) 12
And a sheet-shaped charcoal filter 13 arranged in the subsequent stage for collecting and removing the radioactive gas. However, pre-filter 11 and high-performance filter 12
In some cases, an intermediate filter may be interposed between and.

Specifically, the sheet-shaped charcoal filter 13 is incorporated in a filter device 14 for adsorbing radioactive gas, as shown in FIG. The suction filter device 14 is not made of metal such as iron which is a heavy material as in the conventional case, but is made of a lightweight wooden housing 14a.
An activated carbon sheet charcoal filter 13 is lined inside. The sheet-shaped charcoal filter 13 is formed of a fibrous activated carbon in a sheet-like shape, not by the conventional powdered or granular activated carbon. A suitable material for this type of filter is trade name: activated carbon fiber KF (manufactured by Toyobo Co., Ltd.).

The activated carbon fiber KF is a fibrous activated carbon produced from a cellulose fiber as a raw material and has a surface area of 1
It has a large pore size of 000 to 16000 m ² / g and pores of 5 to 100 Å, and even a thin sheet can capture and remove finely adsorbed substances almost completely, and its adsorption capacity is powdery or granular. It is an adsorbent material that is significantly larger than activated carbon.

Therefore, the adsorption filter device is constructed as follows. That is, a sheet-shaped adsorption material of this type is stretched in a wavy or Z-shape via a regulation rod 14b ... In a housing 14a having an outer size that can replace the existing radioactive adsorption filter device 7 (Fig. 2). The outer dimensions of the housing 14a are, for example, 159 mm in length and 61 in width.
0 mm, depth 292 mm / length 610 mm, width 610 m
m, depth 368 mm / length 159 mm, width 610 mm, depth 678 mm, etc. Further, since the housing 14a is not formed of a heavy material such as an iron plate, but the charcoal filter is lightened in the form of an activated carbonized sheet, a lightweight member such as wood can be used. .

The sheet-shaped charcoal filter 1
Both ends of 3 are fixed to the inside of the outer frame of the housing 14a by adhesion or fasteners. In any case, the sheet-shaped charcoal filter 13 is efficiently and firmly lined so as to have a large collection area and to withstand long-term ventilation.

As described above, according to the above-described embodiment, the activated carbonized sheet-like charcoal filter 13 is interposed in the gas treatment path of the air-conditioning facility, and the radioactive iodine is passed by passing through the sheet-like charcoal filter 13. Since the radioactive gas component is collected and removed, the weight can be remarkably reduced as compared with the conventional one using powdery or granular activated carbon. Further, it is possible to obtain a high collecting and removing action, improve the handleability, and reduce the cost.

Further, if the outer size of the housing 14a of the filter device 14 for adsorbing radioactive gas is set to an external size that can replace the existing filter device for adsorbing radioactive gas, the existing air purifying device 3 will be modified. Instead, the air purifying device 10 that collects and removes the radioactive gas through the activated charcoal sheet charcoal filter 13 can be used.

Next, a second embodiment will be described with reference to FIG. The filter device 14 for adsorbing radioactive gas has the same configuration as that of the above-described first embodiment, but a sheet-like charcoal filter 13 is attached after the high-performance filter 12 afterwards.

That is, since the high-performance filter 12 has a higher collecting and removing action, as shown in FIG. 5, the high-performance filter device 12a regulated by the support plate 16 composed of the lower placing plate and the side plate is vertically moved. It is normally lifted upward by the moving mechanism 15, and its upper peripheral edge is in close contact with the upper partition plate 10b to be airtight. In addition, 12b is a packing.

Therefore, the high-performance filter device 12a is provided on the left and right sides of the filter device 14 for adsorbing radioactive gas.
The engaging portion 14b that is hooked to the lower portion 15c of the vertical movement mechanism 15 is provided, so that the filter device 14 for adsorbing radioactive gas is provided at the subsequent stage of the high performance filter device 12a according to the operation of the vertical movement mechanism 15. It is configured.

FIG. 6 shows a state in which the filter device 14 for adsorbing radioactive gas has been lowered downward along with the high-performance filter device 12b. Reference numeral 15a is a rotary handle for vertical movement, and 15b is a telescopic shaft for vertical movement.
Note that the vertical movement mechanism 15 adopts well-known technical means as long as it has the above-mentioned operation, and
The design can be changed as appropriate. Therefore, the vertical movement mechanism 1
The detailed description and illustration of 5 are omitted.

As a result, in the existing air purifying device 3, even if the filter device 6a for adsorbing the radioactive gas is not arranged at the subsequent stage of the high performance filter 5a, the unused space on the exhaust side in the air purifying device 3 is provided. As the filter device 14 for adsorbing radioactive gas, a charcoal filter 13 in the form of a sheet having activated carbon can be easily newly installed.

Of course, the activated charcoal sheet charcoal filter 13 can be arranged not only on the exhaust side as shown in FIG. 4 but also in place of the conventional prefilter 4, and the prefilter device can be used. It can be arranged on the upper side of 4a or the like, and can also be installed in an unused space of an existing air purifying device. However, if the conventional filter device 7 for adsorbing radioactive gas using powdered or granular activated carbon is provided with the engaging portion 14b, it can be hooked under the vertical movement mechanism 15 of the conventional high performance filter device 5a. Is.

According to this embodiment, the filter device 14 for adsorbing radioactive gas has a significantly reduced weight, a high trapping / removing action, and an improved handling property, and the existing air purifying device 3 is not used at all. The filter device 14 for adsorbing radioactive gas can be retrofitted without modification, the cost is reduced, the concentration of the radioactive gas discharged into the atmosphere is reduced, and strict regulations are set. Even if you do, you can easily follow the regulations.

FIG. 7 shows an activated carbonized sheet-like charcoal filter 1 in the gas treatment path 21 of the radioactive waste treatment hood 20 proposed by the applicant earlier.
3 shows the case where 3 is attached. Reference numeral 22 is a lighting device, 23 is an opening / closing door, and 24 is an incinerator for radioactive organic waste liquid incorporated in the hood.

As described above, according to each embodiment of the present invention, the radioactive gas generated in the facility is introduced into the inflow port 10c.
Through the pre-filter 11 to remove relatively large coarse dust, and then to the high-performance filter 12 to remove fine radioactive substances.

After that, the radioactive carbon such as radioactive iodine is collected and removed through the charcoal filter 13 in the form of a sheet charcoal which is activated and carbonized in the filter device 14 for adsorbing the radioactive gas, and the remaining purified gas is removed. Is discharged to the outside of the facility through the discharge port 10d.

This sheet-shaped charcoal filter 13
When the filter expires and the filter is replaced, the adsorption filter device 14 is taken out from the air purification device 10 and a new adsorption filter device 14 is inserted into the air purification device 10 as in the conventional case. As described above, since the sheet-shaped charcoal filter 13 is made lightweight, the suction filter device 14 is necessarily made lightweight, and the handling property at the time of replacement is remarkably reduced as compared with the conventional case. .

Therefore, not only the manufacturing cost of the filter device 14 for adsorbing radioactive gas can be reduced, but also the working time and labor cost can be reduced, so that the overall cost of this type of device can be significantly reduced. Becomes

Further, when the outer frame of the adsorption filter device 14 is provided with the engaging portion 14b which is hooked in the air purifying device, the activated charcoal sheet charcoal that is activated carbonized in advance after the high performance filter 12 is provided. Even if the filter 13 is not arranged, it is possible to newly install the activated carbonized sheet-like charcoal filter 13 to collect the radioactive gas in the unused space on the discharge side in the air purifying device. There is no need to replace the device with a new air purification device, and the overall cost of this type of device can be significantly reduced.

The arrangement of the sheet-shaped charcoal filter 13 for this type of air purifier can be variously arranged other than the above. The sheet-shaped charcoal filter 13 may be a non-powdered or non-granular activated carbonized sheet-shaped charcoal filter instead of using powdered or granular activated carbon.

[0033]

As described above, according to the present invention, the weight of the adsorption filter device for collecting and removing the radioactive gas is remarkably reduced, the handleability is improved, and the cost is reduced. Can be realized.

Further, an adsorption filter device for collecting and removing a radioactive gas component can be retrofitted to an existing air purifying device, and the existing air purifying device can be installed without significantly modifying the existing air purifying device. Can be collected and removed, and the cost required for the equipment can be significantly reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method for treating a radioactive gas according to the present invention.

FIG. 2 is an explanatory view showing an example of a filter device for adsorbing radioactive gas according to the present invention.

FIG. 3 is an explanatory diagram showing a case where a sheet-shaped charcoal filter is attached after the high-performance filter.

FIG. 4 is an explanatory diagram showing a case where a sheet-shaped charcoal filter is replaced with a pre-filter.

5 is an explanatory diagram showing an internal structure of the air purifying apparatus in FIG. 3. FIG.

FIG. 6 is an explanatory view showing a state in which the vertical movement mechanism operates downward in FIG.

FIG. 7 is an explanatory diagram showing an example of a case where a sheet-shaped charcoal filter is applied to a hood for treating radioactive waste.

FIG. 8 is an explanatory diagram showing an outline of a facility having an air purifying device.

FIG. 9 is an explanatory diagram showing an example of a conventional air purification device.

FIG. 10 is an explanatory view showing another example of a conventional air purifying device.

FIG. 11 is an explanatory diagram showing an example of a conventional filter device for adsorbing radioactive gas.

FIG. 12 is an explanatory diagram showing an outline of a housed state of a conventional air purifier.

[Explanation of symbols]

10 Air Purifier 11 Pre-filter 12 High Performance Filter 13 Activated Carbonized Sheet Charcoal Filter 14 Radioactive Gas Adsorption Filter Device

Claims (8)

[Claims] 1. An activated carbonized sheet-like charcoal filter is incorporated in a filter device for adsorbing a radioactive gas, which is interposed in a gas treatment path of an air-conditioning facility. A method for treating a radioactive gas, which comprises collecting and removing a gas component. 2. A filter device for adsorbing a radioactive gas, which incorporates an activated carbonized sheet-like charcoal filter, is a filter device for adsorbing a radioactive gas in an existing air purifying device interposed in a gas treatment path of an air conditioning facility. A method of treating a radioactive gas, wherein the sheet-shaped charcoal filter activated and carbonized in an existing air purifier is used to collect and remove the radioactive gas component. 3. A filter device for adsorbing a radioactive gas, which incorporates an activated carbonized sheet-like charcoal filter, is provided with an engaging portion that can be retracted and retracted in an existing air purifying device, and the existing air purifying device is provided. The above-mentioned filter device for adsorbing radioactive gas can be attached to the device afterwards, and the radioactive charac- teristic is characterized by collecting and removing the radioactive gas component by the activated charcoal sheet charcoal filter in the existing air purification device. Gas treatment method. 4. The method of treating radioactive gas according to claim 1, wherein the charcoal filter in the form of activated carbon is in the form of woven fabric, non-woven fabric, honeycomb, paper or the like. 5. In an air purifying device interposed in a gas treatment path of an air conditioning facility, a filter device for adsorbing radioactive gas, which is replaceably inserted in the air purifying device, is provided inside a lightweight housing such as wood. A filter device for adsorbing a radioactive gas, wherein an activated carbonized charcoal filter in a sheet shape is stretched, and a radioactive gas component is collected and removed by passing through the charcoal filter in a sheet shape. 6. A filter device for adsorbing radioactive gas, which incorporates an activated carbonized sheet-like charcoal filter, and a filter device for adsorbing radioactive gas of an existing air purifying device interposed in a gas treatment path of an air conditioning facility. A filter device for adsorbing a radioactive gas, which is formed so that it can be replaced, and enables the collection and removal of a radioactive gas component by a sheet-like charcoal filter activated and carbonized in an existing air purifying device. 7. A filter device for adsorbing radioactive gas, which incorporates a charcoal filter in the form of a charcoal sheet activated by carbonization, is provided with an engaging portion which can be retracted in an existing air purifying device so as to be retractable. The above-mentioned radioactive gas adsorption filter device can be attached to the device afterwards, and it is possible to collect and remove the radioactive gas by the activated carbonized sheet-like charcoal filter in the existing air purification device. Filter device for adsorption of radioactive gas. 8. The activated charcoal sheet charcoal filter is woven, non-woven, honeycomb, paper or the like.
A filter device for adsorption of the radioactive gas described.