JP2000075093A - Filter chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and safely exchange a filter without diffusing radioactivity contamination from the primary space side of air inlet side of chamber separated with filter into the secondary space side of air outlet side. SOLUTION: A filter chamber has an air inlet 21 and an air outlet 22 and is attached so as to separate the primary space of the air inlet side of the chamber and the secondary space of the air outlet side. It also has a filter 23 for filtering the air passing from the primary space side to the secondary space side. Also, a filter introduction piece 31 introducing a new filter 33 is provided in the secondary space side of the chamber. The new filter introduced in the secondary space of the chamber is moved to a filter attachment position by a lift 25 and an old spent filter is pushed to the primary space side of the chamber. The old filter is taken out to the outside of the chamber from a filter outlet piece 34 provided in the primary space side in the state air-tightly packed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter having an air inlet and an air outlet, a filter mounted inside a chamber through which air flows from the air inlet to the air outlet, and from the air inlet to the air outlet. The present invention relates to a filter chamber for filtering air passing through a filter and exhausting only air from which dust has been removed from an air outlet. In particular, the present invention relates to a filter chamber in which a filter can be easily replaced without air containing dust flowing out to an air outlet side.

[0002]

2. Description of the Related Art For example, in a facility for handling radioactive materials and nuclear fuel (hereinafter referred to as "RI facility"), dust contaminated by radioactivity is removed from the air and exhausted outside the RI facility. A simple filter chamber is used. In some cases, facilities for handling unsealed radioactive materials, such as glove boxes and hot cells, and hermetically packaging them are provided in RI facilities. By making the pressure inside these facilities lower than the atmospheric pressure, the radioactive substances inside are prevented from leaking to the outside.

[0003] In order to make the pressure of the RI facility lower than the outside pressure, an exhaust system is provided, and air containing radioactively contaminated dust inside the facility is filtered using a filter and exhausted to the outside. . However, if the filter is used for a predetermined time, it must be replaced because it causes clogging.
Therefore, a small room called a filter chamber is provided in the middle of the exhaust path, and a structure is provided in which the filter can be attached, and the filter is replaced as needed.

[0004] When the filter is replaced, radioactively contaminated dust and the like are attached to the side of the filter into which the air flows. Therefore, the filter must be replaced with a new filter so as not to spread to the outside. Therefore, in the related art, the filter is generally replaced by a method called a bag-out method. According to this method, a vinyl bag is attached to the filter exchange port of the filter chamber in advance, the operation of the exhaust equipment is stopped, the old filter in the chamber is removed and put into the vinyl bag, the vinyl bag is sealed, and the filter exchange port is removed. Disconnect from Thereafter, the new filter is placed in a new vinyl bag, and the new filter is attached to the filter replacement port with the new bag placed over the old bug remaining after being cut off. Then, after setting the filter at a predetermined position in the chamber, the operation of the exhaust equipment is restarted.

Referring to FIGS. 5 to 7, a description will be given of the configuration of a filter chamber for exchanging a filter using such a bag-out system and the procedure of exchanging the filter. 5 to 7 show cross sections of a general filter chamber. Reference numeral 5 denotes a chamber, which is, for example, a vertical rectangular tube. An air inlet 6 is provided at the top of the chamber 5, and exhaust air containing radioactively contaminated dust enters the chamber 5 from the air inlet 6. An air outlet 7 is provided at a lower portion of the chamber 5, and clean air from which dust contaminated with radioactivity has been removed is exhausted from the air outlet 7. That is, in the chamber 5, the air flows from the air inlet 6 on the upstream side to the air outlet 7 on the downstream side.

[0006] The filter 8 allows only air to pass through the filter up and down and filters the particles without passing through the filter. The filter 8 is attached to the chamber 5 at an intermediate portion between the air inlet 6 and the air outlet 7. The filter 8 is placed on a lift 10 and the lift 10
Is pressed against the filter receiver 11 from below. Thus, the filter 8 is attached so as to completely separate the primary space on the air inlet 6 side of the chamber 5 from the secondary space on the air outlet 7 side. The lift 10 has a structure in which the filter 8 can be moved up and down from outside the chamber 5. A pre-filter 9 for removing coarse dust is provided on the main filter 8.

A filter exchange port 19 for exchanging a used old filter 8 with a new filter 16 is provided on a side surface of an intermediate portion of the chamber 5 in which the filter 8 is installed. A bag sheet 12 such as a highly airtight vinyl bag is stretched over the filter replacement port 19.
The bag sheet 12 is provided with a working glove 13. 5 and 7, reference numeral 14 denotes a lid fitted to the outside of the filter replacement port 19 to protect the bag sheet 12. In FIGS. 5 to 7, the dust 19 contaminated by radioactivity is indicated by dots.

A procedure for replacing a used old filter 8 with a new filter 16 in such a bag-out type filter chamber will be described below. First, the operation of the exhaust system is stopped. Next, the lift 10 is lowered from the state shown in FIG. 5A, and the filter 8 is separated from the filter receiver 11. The lid 14 of the filter exchange port 19 is opened, and the old filter 8 is pulled out into the bag sheet 12 using the glove 13 as shown in FIG.

Next, as shown in FIG. 6A, the space between the filter 8 and the filter replacement port 19 of the bag sheet 12 is squeezed, and the narrowed portion 15 is squeezed using a high frequency sealer or the like.
To seal and separate the bag sheet 12. As a result, the bag sheet 12 is separated into a packaging sheet 12a in which the filter 8 is packaged and a seal sheet 12b for closing the filter replacement port 19. The filter 8 is treated as radioactive waste together with the wrapping sheet 12a that wraps the filter.

Next, as shown in FIG. 6B, a new bag sheet 17 containing a new filter 16 is hermetically attached to the filter exchange port 19 so as to cover the seal sheet 12b. At this time, the edge of the seal sheet 12b which is a part of the old bag sheet 12 is turned over. Thereafter, the user puts his hand into the new bag sheet 17 through the glove 18, turns over the edge of the seal sheet 12b which is a part of the old bag sheet 12, removes the edge, and separately bags out as waste. Thereafter, a new filter 16 is placed on the lift 10 as shown in FIG. FIG.
As shown in (b), the new filter 16 is raised by the lift 10 and the filter 16 is placed in the filter receiver 11.
Press Thus, the replacement of the filter is completed. Thereafter, the stopped exhaust equipment is returned to the operating state.

[0011]

In the bag-out type filter chamber as described above, the operation of the exhaust system is stopped when the filter 8 is replaced. Naturally, the upper surface side facing the primary space 8 is radioactively contaminated.
However, there is a time period during which the filter does not exist until the old filter 8 is removed from the predetermined filter mounting position to replace the filters 8 and 16 and the new filter 16 is mounted.

At this time, since the operation of the exhaust system has been stopped, the possibility that the radioactively contaminated dust does not immediately diffuse to the secondary space side cannot be completely denied. That is, if radioactive contamination spreads to the secondary space side while replacing many filters 8 and 16 over a long period of time, even if a new filter 16 is installed, it will be closer to the air outlet 7 side than the filters 8 and 16. There is also the possibility that radioactive contamination will diffuse into the secondary space.

The present invention has been made in view of the above problems, and when replacing an old filter with a new filter, radiates from the primary space side of the air inlet side of the chamber partitioned by the filter to the secondary space side of the air outlet side. No pollution is spread
It is another object of the present invention to provide a filter chamber in which a filter can be easily and safely replaced.

[0014]

According to the present invention, in order to achieve the above object, when replacing an old filter with a new filter, the old filter is removed and the filter is mounted while the new filter is being mounted. The state which is not done was completely eliminated. For this purpose, a new filter 33 is introduced into the uncontaminated secondary space, and this is overlaid on the old filter 23. Then, a new filter 33 is attached to a predetermined filter mounting position from the secondary space side where there is no radioactive contamination, and the old filter 23 is pushed out to the primary space flow side where radioactive contamination is present. Can be backed out. During this time, one of the filters 23 and 33 always maintains the filtering function as a filter, and radioactive contamination does not leak from the primary space to the secondary space.

That is, the filter chamber according to the present invention has an air inlet 21 and an air outlet 22,
A chamber 20 having a space through which air flows from the first side to the air outlet 22 side;
And a filter 23 for filtering air passing from the primary space side to the secondary space side.

According to the present invention, in such a filter chamber, a filter inlet 31 provided on the secondary space side of the chamber 20 having the air outlet 22 for introducing a new filter 33 into the secondary space is provided. The new filter 33 introduced into the secondary space of
And a mechanism for moving the used old filter 23 to the primary space side of the chamber 20 and a mechanism for moving the used old filter 23 to the primary space side of the chamber 20 having the air inlet 21 and being pushed out to the primary space side. And a filter outlet 34 for taking out the used and used old filter 23 in a state of being airtightly packaged outside the chamber 20.

The moving mechanism moves the new filter 33 introduced from the filter inlet 31 into the primary space of the chamber 20 to the filter mounting position of the chamber 20, and removes the old filter 23 used by the new filter 33 into the chamber. This is a mechanism for pushing out to the primary space 20 side. For example, when the chamber 20 has a cylindrical shape through which air flows from the primary space above the filters 23 and 33 to the secondary space below the same, the moving mechanism pushes the filters 23 and 33 from below. A lift 25 can be used. A bag sheet 26 for airtightly packing and taking out the filters 23 and 33 is attached to the filter outlet 34, and the bag sheet 26 is provided with a glove 27 for manual operation.

In the above-mentioned filter chamber, a new filter 33 is introduced from the filter inlet 31 into the secondary space side of the chamber 20 free from radioactive contamination, and can be set at a predetermined filter mounting position from this secondary space. . At the same time, the used old filter 23 is pushed out to the primary space side which is contaminated with radioactivity, and is pushed out of the filter outlet 34.
Take out the package from the airtight. Therefore, filter 2
When replacing 3, 33, there is no time in the chamber 20 when there is no filter separating the primary space and the secondary space. That is, the primary space and the secondary space of the chamber 20 always correspond to the old filter 23 or the new filter 33.
It will be divided by. Thereby, the radioactively contaminated dust does not diffuse from the primary space side where the radioactively contaminated dust is present to the secondary space where the radioactively contaminated dust is not present.

[0019]

Embodiments of the present invention will now be described specifically and in detail with reference to the drawings.
3 and 4 show an example of a filter used in a filter chamber according to the present invention, and are external views of a high-performance air filter used particularly for removing radioactive dust. The most common filter is 61 with one side open up and down
It has a square box 3 cm and a 30 cm height.
This box 3 is usually made of wood. A packing 4 is provided on the upper edge of the box 3. The filter medium 1 is formed by bending a non-woven sheet up and down, and a separator 2 for keeping an appropriate gap between the filter medium 1 is inserted. This filter only allows air to pass vertically above and below in FIGS. 3 and 4, and particles are caught by the filter medium 1 and do not pass.

Referring to FIGS. 1 and 2, the construction of a filter chamber that uses such a filter and replaces the filter as needed, and the procedure for replacing the filter accordingly will be described. The chamber 20 has, for example, a vertical rectangular tube shape. An air inlet 21 is provided at the top of the chamber 20, and exhaust gas containing radioactively contaminated dust enters the chamber 20 from the air inlet 21. An air outlet 22 is provided at a lower portion of the chamber 20, and clean air from which radioactively contaminated dust is removed is exhausted from the air outlet 22.
That is, in the chamber 20, the air flows from the air inlet 21 on the upstream side to the air outlet 22 on the downstream side.

The filter 23 as described above is provided in the chamber 20.
At an intermediate portion between the air inlet 21 and the air outlet 22 of the air conditioner. The filter 23 is placed on a lift 25, and is installed at a filter mounting position in an intermediate portion of the chamber 20 by the lift 25. The lift 25 has a structure that allows the filter 23 to be moved up and down from outside the chamber 20.

The inner wall of the chamber 20 at the filter mounting position abuts against the outer wall of the box 3 (see FIGS. 3 and 4) of the filter 23 disposed at the filter mounting position. There is provided a packing 30 for hermetically sealing and sandwiching the outer surface. This packing 3
0, the filter 23 is connected to the air inlet 2 of the chamber 20
It is mounted so as to completely separate the primary space on the one side and the secondary space on the air outlet 22 side. In addition, this packing 30
Has a holding force with respect to the filter 23 fitted between them, and can hold the filter 23 therewithout being supported by the lift 25 from below.
On this main filter 23, a pre-filter 24 for removing coarse dust is provided.

On the side surface of the chamber 20 above the position where the filter 23 is installed, a filter outlet 34 is provided for removing the used old filter 23 from the primary space of the chamber 20. This filter outlet 3
4 is a bag sheet 2 such as a highly airtight vinyl bag.
The bag sheet 26 is provided with a working glove 27. Further, a cover 28 is fitted outside the filter outlet 34 to protect the bag sheet 26.

A filter inlet 31 for introducing a new filter 33 to be exchanged into the secondary space of the chamber 20 is provided on the side of the chamber 20 on the secondary space side below the portion where the filter 23 is installed. ing. A lid 29 is fitted on the outside of the filter introduction port 31.
1 and 2, the radioactively contaminated dust 32 in the chamber 20 is schematically shown by dots.

In the filter chamber as described above,
Next, a procedure for replacing the used old filter 23 with the new filter 33 will be described. First, the operation of the exhaust system is stopped to replace the filter. Next, the lift 25 is lowered from the state shown in FIG. 1A as shown in FIG. 1B. Opening the lid 29 of the filter inlet 31, FIG.
As shown in (b), a new filter 33 to be replaced is introduced into the secondary space of the chamber 20, placed on the lift 25, and placed just below the old filter 23.

Next, as shown in FIG.
As the new filter 33 is raised, the upper surface of the new filter 33 comes into contact with the lower surface of the old filter 23.
Since the lower surface of the old filter 23 is located on the secondary space side of the chamber 20, the contaminated dust does not adhere thereto. When the new filter 33 is further lifted from the position shown in FIG. 1C by the lift 25, the old filter 23 placed thereon is also raised at the same time, and finally the new filter 33 is lifted.
Is installed at a predetermined filter mounting position sandwiched by the packing 30, and the old filter 23 is pushed out to the primary space side of the chamber 20. This state is shown in FIG.

From this state, the old filter 23 is backed out from the primary space side of the chamber 20 and treated as contaminated waste in the same manner as in the above-described conventional filter chamber. That is, the lid 28 of the filter outlet 34 is opened,
Using the glove 27, the bag sheet 2 as shown in FIG.
Pull out the old filter 23 into 6. Thereafter, the space between the filter 23 and the filter outlet 34 in the bag sheet 26 is squeezed, and the bag sheet 26 is sealed and cut off at the squeezed portion using a high frequency sealer or the like. As a result, the bag sheet 26 is separated into a wrapping sheet that wraps the filter 23 and a seal sheet that closes the filter outlet 34. Therefore, the filter outlet 34 remains closed. Used filter 23 that has been backed out
Is treated as radioactive waste together with the packaging sheet that wraps it.

Next, the new bag sheet is hermetically attached to the filter outlet 34 so as to cover the above-mentioned sealing sheet which is a part of the old bag sheet. After this, put your hand in the bag sheet through the glove of the bag sheet,
Remove the seal sheet and bag it out separately as waste. Thus, the replacement of the filter is completed. Thereafter, the stopped exhaust equipment is returned to the operating state.

In the above-mentioned filter chamber, a new filter 33 is introduced into the secondary space of the clean chamber 20 through the filter inlet 31 and is set at the filter mounting position, and at the same time, the used old filter 23 is removed. It is extruded into the primary space and can be taken out of the filter outlet 34 in an airtight package. in this way,
Old filter 23 and new filter 3 in chamber 20
When replacing with 3, any one of the filters 23 and 33 is always at a predetermined filter mounting position, so that the contaminated dust is contaminated in the secondary space where there is no contaminated dust from the primary space side where the contaminated dust is present. Does not spread.

In the above description, an example is shown in which the filter chamber according to the present invention is used in an exhaust device used in an RI facility, but the filter chamber according to the present invention is not limited to use in such fields. For example, it is apparent that the present invention can also be applied as a filter chamber for introducing clean air into a clean room used in semiconductor manufacturing, precision pattern printing, and the like.

[0031]

As described above, according to the present invention, when replacing an old filter with a new filter, the secondary space from the air inlet side primary space side to the air outlet side of the chamber partitioned by the filter. The radioactive contamination is not diffused to the filter, and the filter can be easily replaced. This allows
Problems such as diffusion of radioactive contamination to the clean space side when replacing the filter are eliminated, and radioactive contamination or the like due to an operation error can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a filter chamber according to the present invention and a first half of a procedure for replacing a filter using the same.

FIG. 2 is a sectional view showing a latter half of a procedure for replacing a filter using the filter chamber.

FIG. 3 is a perspective view showing an example of a filter used in the filter chamber.

FIG. 4 is a vertical sectional side view showing an example of a filter used in the filter chamber.

FIG. 5 is a vertical sectional side view showing an example of a filter used in the filter chamber.

FIG. 6 is a cross-sectional view showing a first example of a conventional example of a filter chamber and a replacement procedure of a filter using the same.

FIG. 7 is a cross-sectional view showing the latter half of the procedure for replacing the filter using the conventional filter chamber.

[Explanation of symbols]

 Reference Signs List 20 chamber 21 chamber air inlet 22 chamber air outlet 23 old filter 25 lift 26 bag sheet 27 bag sheet glove 31 filter inlet 33 new filter 34 filter outlet

Claims (3)

[Claims] A chamber (20) having an air inlet (21) and an air outlet (22), and having a space through which air flows from the air inlet (21) side to the air outlet (22) side. It is attached so as to partition the primary space on the air inlet (21) side and the secondary space on the air outlet (22) side in the chamber (20), and filters air passing from the primary space side to the secondary space side. A filter chamber having an air outlet (22);
A filter inlet (31) provided on the secondary space side of (0) for introducing a new filter (33) into the secondary space, and a new filter (33) introduced into the secondary space of the chamber (20). To the filter mounting position of the chamber (20), and to push out the used old filter (23) to the primary space side of the chamber (20); and a mechanism for moving the chamber (20) having the air inlet (21). A filter outlet (34) provided on the primary space side and for taking out the used old filter (23) pushed out to the primary space side in a state of being airtightly packaged outside the chamber (20). Filter chamber characterized. The moving mechanism moves a new filter (33) introduced from the filter inlet (31) into the secondary space of the chamber (20) to a filter mounting position of the chamber (20), and moves the new filter (33). The filter chamber according to claim 1, characterized in that it is a mechanism for pushing out the old filter (23) used in the filter (33) to the primary space side of the chamber (20). 3. The chamber (20) includes a filter (2).
3), a cylindrical type through which air flows from the primary space above the (33) to the secondary space below it, and the moving mechanism is a lift that pushes up the filters (23) and (33) from below. The filter chamber according to claim 1 or 2, wherein (25).