JPH0529044Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a filtration device for waste liquid, etc., and more specifically, after filtering the raw liquid to be filtered for a certain period of time,
The present invention relates to a filtration device configured so that when removing residual liquid from the filtration device, no stock solution is contained in the extracted liquid.

[Prior art]

When waste fluids such as cleaning fluids at nuclear power plants are filtered, the waste fluids contain radioactive substances, so special care must be taken when handling the filtration device after a certain period of filtration. Normally, the radiation dose inside a filtration device that has been used for a certain period of time has reached a considerable level, so the entire filtration device unit is covered with lead radiation shielding material and sealed before being transported to a processing facility where it is treated. ing. Before sealing the filtration device, it is necessary to pump out the residual liquid inside the device, but this residual liquid contains both the undiluted liquid before passing through the filter and the filtrate after passing through it. All of which must be extracted. However, since the raw solution is unfiltered and contains radioactive filtration residue in the device that has been concentrated through filtration, pumping it out as it is is difficult for subsequent processing and poses operational hazards. be. Therefore, all of this stock solution is filtered through the filter inside the device.
The applicant has devised a method of filtering the filtrate and then pumping it out, and an application has already been filed for a undiluted solution processing device based on this method. (Jitsugan No. 58-163103).

The processing device has three chambers in its sealed main body: an upper chamber that is a filtrate chamber, an intermediate chamber that is a stock solution chamber, and a lower chamber that is used to filter and temporarily store the remaining stock solution when removing the remaining solution. Furthermore, the upper chamber is provided with a processing liquid communication pipe for guiding the residual filtrate to the lower chamber, and a drainage pipe for draining the residual liquid from the lower chamber to the outside of the main body.

In addition, the cartridge type filter described in JP-A-57-194014 inserts a residual treated water discharge capillary into a hollow part of the filter element, and opens its lower end near the bottom of the filter, so that the inside of the filter is The residual treated water is force-fed by the pressurized air introduced into the chamber, and is discharged from the residual treated water discharge capillary.

[Problem that the invention attempts to solve]

In the latter treatment device described in JP-A-57-194014, the residual treated water discharge capillary opens near the bottom of the filter to discharge the residual treated water. must reach the bottom. Otherwise, the water to be treated near the bottom cannot be filtered and introduced into the filter element.

In this way, if the filtration portions of the plurality of filter elements are all configured to reach the vicinity of the bottom surface, the highly concentrated untreated residual liquid that gradually accumulates near the bottom surface of the filter will be constantly treated. As a result, all the filters became clogged relatively quickly, resulting in a reduction in the throughput of the filter.
Furthermore, there is a drawback that the treated water treated at the bottom of the filter is contaminated and of poorer quality than the treated water treated at the upper part of the filter. Furthermore, if you try to suck the liquid to be treated into the filter from the bottom of the treatment equipment with sludge containing radioactive materials deposited on the bottom, there is a risk that the flow will stir up the sludge near the bottom, and the treated water will This has the disadvantage that the water quality deteriorates and the upper part of the filter tends to clog more quickly.

The above-mentioned processing device proposed earlier is configured so that the undiluted solution is not contained in the extracted liquid, so there is no need for post-treatment of the extracted liquid, and the practical effect is very large. be.

However, in order to prevent the stock solution from being included in the pumped solution, in addition to the middle chamber as the stock solution chamber and the upper chamber as the filtrate chamber, this device also has a lower chamber for pumping out the remaining solution. In addition, it is necessary to provide a processing liquid communication chamber that communicates the lower chamber and the upper chamber, so it is inevitable that the apparatus becomes complicated.

Therefore, the present invention improves the processing device proposed by the present applicant, exhibits the same effect with a simpler structure, and eliminates the drawbacks of the filter described in JP-A-57-194014. The purpose is to provide a highly reliable filtration device that is difficult to clog and has a large processing capacity, and the following measures are taken to achieve this purpose.

[Means to solve the problem]

In the filtration device of the present invention, a position at a slight height from the bottom wall 4 at the lower end is liquid-tightly partitioned by a bottom partition plate 29,
The stock solution chamber 7 is located on the lower side above the bottom partition plate 29.
A housing 1 made of a bottomed cylindrical body with a filtrate chamber 8 provided on the upper side, and a stock solution introduction path 12 for communicating the outside of the housing 1 and the stock solution chamber 7.
and a plurality of cylindrical filters 14 which are provided in the stock solution chamber 7 and whose filtration lower ends are spaced upward by a certain amount or more from the bottom partition plate 29, and whose lower ends are located below the top surface of the bottom partition plate 29. Only one cylindrical filter 14 is located, and its filtration lower end reaches the upper surface of the bottom partition plate 29, the hollow part 19 on the filtration side of each of the cylindrical filters 14, and the filtrate chamber 8.
A filtrate discharge passage 23 for communicating with the filtrate is inserted into the hollow part 19 of only one cylindrical filter 14 whose lower end reaches the bottom partition plate 29, and reaches the position of the bottom partition plate 29. It is characterized by comprising a residual liquid extraction conduit 25 which is substantially reached by the suction section.

[Examples and effects]

Next, embodiments of the present invention will be described based on the drawings. FIGS. 1 and 2 are a longitudinal sectional view and a plan view showing an embodiment in which the filtration device of the present invention is used for treating radioactive substance-containing waste liquid.

The housing 1 has a side wall 3 and a bottom wall 4 filled with lead 2 for radiation shielding, and further has a lower stock solution chamber 7 and an upper filtrate chamber 8 separated by a partition wall 5 and an upper plate 6. It has two sealed chambers. The peripheral edge of the upper plate 6 is extended downward and joined to the partition wall 5 to form a filtrate chamber 8, and the partition wall 5 is connected to a support member 10 attached to the inner wall 9 of the housing 1.
It is fixed by a bolt 11. A stock solution introduction path 12 for communicating the stock solution chamber 7 with the outside of the housing 1 is provided passing through the filtrate chamber 8 .
The introduction path 12 is formed in a cylindrical shape, has a coupler 13 on the outside of the upper plate 6 for coupling with an external stock solution pipe, and has an opening in the stock solution chamber 7 for discharging the stock solution. This opening is open only toward the bottom surface of the stock solution chamber 7 and both sides of the inner wall 9, and is designed to prevent the flow of the stock solution from being directed directly toward the outer peripheral surface of the cylindrical filter, which will be described later.

A plurality of cylindrical filters 14 are vertically provided in the stock solution chamber 7 with their upper portions supported by the partition wall 5 . As shown in FIG. 2, a total of seven cylindrical filters 14 are provided, one in the center of the concentrated solution chamber 7 and six around the concentrated solution chamber 7 excluding the position of the concentrated solution introduction path 12. The number can be any number greater than or equal to three.

The cylindrical filter 14 is composed of a cylindrical filter element 15 and an upper support 16 and a lower support 17 that support it from above and below.
It is designed to pass in nine directions. The lower support 17 is coupled to the lower end of a shaft 20 that is provided so as to pass through the hollow portion 19 on the filtration side. The shaft 20 extends into the upper filtrate chamber 8 through the opening of the partition wall 5, has a plurality of liquid flow holes on the side at its end, and has a lower portion fixed to the upper surface of the partition wall 5. It is connected to the top of a cap-shaped mounting member 21 with legs. Therefore, each cylindrical filter 14
The hollow portion 19 on the filtration side is communicated with the filtrate chamber 8 through a filtrate communication path 22 consisting of a mounting member 21 and its communication hole.

Next, a cylindrical filtrate discharge passage 23 for communicating the filtrate chamber 8 with the outside of the housing 1 is opened and provided in the upper plate 6 . The discharge passage 23 is provided with a coupler 24 at its upper end for connection to an external filtrate discharge pipe.

Next, a residual liquid extraction conduit 25 is inserted into the hollow part 19 of only one cylindrical filter 14 to communicate the bottom part with the outside of the housing 1. In the example shown in FIG. 1, the conduit 25 is inserted into the hollow part 19 of the right cylindrical filter 14, and its lower end is connected to the lower support 17. The upper part of the conduit 25 is an opening in the partition wall 5,
It passes through the top of the cap-shaped mounting member 21 with legs and the upper plate 6 in order, and is fixed to at least the mounting member 21 . Further, a coupler 26 is provided at the upper end of the conduit 25 for connection to an external piping for removing residual liquid.

Although the lower end surface of the conduit 25 is closed, at least one communication hole 27 is provided on the side surface of the lower end, and this communication hole 27 allows the hollow portion 1
The bottom of the housing 9 and the outside of the housing 1 are communicated with each other. Further, the cylindrical filter 14 into which the conduit 25 is inserted is located relatively below other cylindrical filters 14 into which it is not inserted. Therefore, the upper support 16 that supports the cylindrical filter 14 is attached to the lower surface of the partition wall 5 via the extension cylinder 28, and the lower support 17 is attached to the bottom partition plate provided at the bottom of the stock solution chamber 7. A recess 30 extending downward from 29
It has been extended to . As a result, the lower part of the filter element 15 of the cylindrical filter 14 is arranged to extend to the bottom of the stock solution chamber 7.
It becomes possible to pump out all the remaining liquid in the stock solution chamber 7.

In FIG. 1, a lid 31 filled with lead 2 is placed on the upper opening of the housing 1, but this lid 31 is removed during the filtration process, and after the filtration process, as shown in the figure. It is mounted to prevent radiation from leaking to the outside, and is used for storage for radiation processing. In addition,
A plurality of hanging tools 32 are provided at appropriate intervals on the edge of the lid 31 for lifting the lid 31 by remote control or the like.

The housing 1 can also be further housed within an external case 33 for convenience of transportation and storage, if desired. At that time, replace the housing 1 with the outer case 3.
Hanging tools 3 are provided at appropriate intervals on the upper side wall 3 of the housing 1 in order to stably support the housing 1.
It is preferable to provide supporting metal fittings 35 on the sides of 4. The support fittings 35 can be configured, for example, by a support column that can be expanded and contracted by adjusting screws. Note that the hanging tool 34 is used when transporting the housing.

Next, the operation of the filtration device shown in FIGS. 1 and 2 will be explained.

When filtering a stock solution such as waste liquid, the stock solution piping is connected to the coupler 13 of the stock solution introduction path 12, and the filtrate discharge piping is connected to the coupler 24 of the filtrate discharge path 23. Note that nothing is connected to the coupler 26 of the residual liquid extraction conduit 25, and the coupler 26 is kept in a sealed state. The couplers 13 and 24 are well-known couplers that communicate with each other when coupled with a pair of male receiving couplers attached to connected pipes, and are automatically sealed when not coupled. can be used.

By connecting the pipes in this way, the stock solution to be filtered passes from the external stock solution pipe through the coupler 13,
The stock solution is introduced into the stock solution chamber 7 through the stock solution introduction path 12 . The stock solution is filtered by the cylindrical filter 14 and collected as a filtrate in the hollow part 19 on the filtration side of the cylindrical filter 14, and then flows into the filtrate chamber 8 through the filtrate communication passage 22. do. The filtrate that has flowed into the filtrate chamber 8 is then discharged through the filtrate discharge path 23 and its coupler 24 to an external filtrate discharge pipe. On the other hand, since the coupler 26 of the remaining liquid extraction conduit 25 inserted into the hollow part 19 of at least one cylindrical filter 14 is sealed,
No filtrate leaks out of the housing 1 through the conduit 25.

When the cylindrical filter 14 becomes clogged and the filtration capacity decreases due to filtration for a certain period of time, or when sludge etc. accumulates in the stock solution chamber 7 and the filtration function reaches its limit, the filtration process is stopped. The device is replaced. To stop the filtration process,
First, the filtrate discharge pipe connected to the coupler 24 of the filtrate discharge path 23 is removed, and the coupler is sealed. Furthermore, the coupler 26 of the residual liquid extraction conduit 25
Connect the piping for removing residual liquid to the vacuum pump. Next, the coupler 13 is opened.

After the filtration process is stopped and preparations for removing the remaining liquid are completed in this manner, the stock solution remaining in the stock solution chamber 7 is filtered through the cylindrical filter 14 and moved to the hollow portion 19 side. The filtrate in the hollow part 19 of the cylindrical filter 14 into which the residual liquid extraction conduit 25 is inserted is transferred to the residual liquid extraction conduit 25 opened at the bottom thereof.
The liquid rises in the conduit 25 through the communication hole 27, and is extracted from the coupler 26 to an external pipe for removing residual liquid.

This completes the operation of removing the remaining liquid from the filtration device. After the residual liquid extraction operation is completed, the coupler 26
Remove the piping connected to. The upper opening of the housing 1 is then sealed with a lid 31 and the processing device is transported to a storage or reprocessing facility.

After the used filtration device is removed in this way, a new filtration device is installed again and the interrupted filtration process is restarted. However, if interruption of the filtration process of the stock solution is not allowed, two lines of filtration equipment may be provided, the external piping may be switched by a switching valve, and the equipment may be used alternately and continuously.

[Effect of idea]

The filtration processing apparatus of the present invention includes only one cylindrical filter 14, and a plurality of other cylindrical filters 1.
Since the lower end of the filtration filter No. 4 is placed at a position a certain distance away from the bottom partition plate 29, it is possible to guide the water to be treated into the filter from a position avoiding the sludge that accumulates on the bottom partition plate 29. becomes.

Thereby, it is possible to improve the reliability of the quality of the treated water, prevent clogging of the filter, and increase the treatment capacity.

When the filtration capacity of the filtration device reaches its limit, the residual liquid up to the vicinity of the bottom partition plate 29 is treated by the residual liquid extraction conduit 25 inserted through only one cylindrical filter, and the residual liquid is discharged to the outside. Since the liquid can be taken out at any time, it is possible to prevent the unprocessed stock solution from being contained in the device, and the entire device can be made compact.

[Brief explanation of the drawing]

1 and 2 are a vertical sectional view and a plan view showing an embodiment in which a filtration device of the present invention is used for treating waste liquid containing radioactive materials.
...Bottom wall, 5...Partition wall, 6...Upper plate, 7...
Raw liquid chamber, 8... filtrate chamber, 9... inner wall, 10...
Support member, 11: bolt, 12: raw liquid introduction passage, 13: coupler, 14: cylindrical filter,
15: filter element, 16: upper support, 17: lower support, 18: outer circumferential surface, 1
9: hollow portion; 20: shaft; 21: mounting member;
22: filtrate communication passage; 23: filtrate discharge passage;
24: coupler; 25: residual liquid drainage conduit; 26:
... coupler, 27 ... flow hole, 28 ... extension cylinder,
29: bottom partition plate; 30: recess; 31: lid;
32: Hanging tool; 33: Outer case; 34:
Lifting device, 35...support bracket.

Claims (1)

[Scope of utility model registration request] The bottom partition plate 2 is located at a slight height from the bottom wall 4 at the lower end.
Housing 1 consists of a bottomed cylindrical body, which is liquid-tightly partitioned by 9, and has a stock solution chamber 7 on the lower side above the bottom partition plate 29 and a filtrate chamber 8 on the upper side.
, a stock solution introduction path 12 for communicating the outside of the housing 1 and the stock solution chamber 7, and a stock solution introduction path 12 provided in the stock solution chamber 7, the lower end of the filtration being located at a position spaced above the bottom partition plate 29 by a certain amount or more. A plurality of cylindrical filters 14 are arranged, and only one cylindrical filter 1 whose lower end is located below the upper surface of the bottom partition plate 29 and whose filtration lower end reaches the upper surface of the bottom partition plate 29.
4, a filtrate discharge passage 23 for communicating the filtration side hollow part 19 of each of the cylindrical filters 14 and the filtrate chamber 8, and one whose lower end of the filtration reaches the bottom partition plate 29. Chisel cylindrical filter 14
is inserted into the hollow part 19 of the bottom partition plate 29.
A filtration device characterized by comprising a residual liquid extraction conduit 25 whose suction section substantially reaches the position of.