JPH0542286B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a filtration device using a plurality of ceramic porous filters, and particularly to a filtration device useful for purifying water containing suspended matter contaminated with radioactivity generated from nuclear power plants. It is something. (Conventional technology) Conventionally, spent reactor internals (channel boxes, control rods, etc.) generated from nuclear power plants, etc.
is stored in a pool filled with water, but when irradiated metal waste contaminated with radioactivity is submerged in the pool, transparency of the pool water is necessary for work. Therefore, a portion of the pool water is constantly filtered and purified using a filtration device consisting of a sintered metal filter. Conventionally used purification filter unit 51
As shown in FIG. 4, four cylindrical sintered metal filters 52 are provided in the unit, and the outside of the filter is covered with a filter can 53. Water stored in the pool is supplied from the upper inlet 54 of the filter body 53, flows from the top of each sintered metal filter 52 through the central channel 55, and flows through the sintered metal filter 52 from the inside to the outside. After being filtered and purified by flowing, it is discharged from the outlet 56. (Problems to be Solved by the Invention) However, the above-mentioned filtration device made of a sintered metal filter has problems that it is expensive and has a short lifespan, as well as a small filtration area, a complicated structure, and a high weight. There were also serious drawbacks. As a means to solve some of these problems, it is possible to use a filtration device made of a ceramic porous body, as described in Japanese Patent Application Laid-open No. 56-148607, but in this case, the ceramic porous body is Since it is a pottery product, there was a problem that only small-sized products could be manufactured, and it was not possible to manufacture products with a large filtration area. SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned problems and to provide a filtration device that can extend its service life, reduce its weight, and be inexpensive. (Means for Solving the Problems) The filtration device of the present invention has a structure in which the front end or the rear end of each through hole of a ceramic porous body having a large number of parallel through holes is regularly and alternately sealed. A ceramic porous filter body, a storage can having a step at the bottom for storing each ceramic porous body and having a filtrate discharge port or stock solution supply port on one side of the step, and a vertical pipe between the inner cylinder and the outer cylinder. A double can body that is divided into two in the direction to form a raw solution flow path and a filtrate flow path, and in which a plurality of storage cans are stacked liquid-tightly with packing between each storage can. A stock solution supply chamber and a filtrate discharge chamber are provided alternately between the adjacent ceramic porous filter bodies, and the stock solution supply chamber is one of two sections divided between the inner cylinder and the outer cylinder of the double can body. It is connected to the stock solution flow path through the stock solution supply port and the inner cylinder, and is connected to the other filtrate flow path that is divided into two parts between the filtrate discharge chamber, the inner cylinder, and the outer cylinder through the filtrate discharge port and the inner cylinder. This is a characteristic feature. (Function) With the above-described configuration, the stock solution to be filtered flows into the stock solution supply chamber from the stock solution flow path, and then is filtered and purified by passing through one of the ceramic porous filters stacked in multiple stages, and the filtrate is discharged. The filtrate is directly discharged to the outside of the filtration device through a filtrate flow path that is separated from the double can body and the stock solution flow path via a chamber. At this time, since the stock solution channel and the filtrate channel in the double can are completely separated, there is no mixing of the stock solution and the filtrate, and the filtration and purification work can be performed reliably. In addition, since we use ceramic porous filters that are lightweight and cheaper than sintered metals, the filtration device can be made inexpensive and lightweight, and multiple ceramic porous filters can be stacked in parallel. Since the filtration device is formed by using multiple filters, the filtration area can be made extremely large. (Example) First, the ceramic porous filter used in the present invention will be explained. FIGS. 1a, 1b, and 1c are a side view and a vertical cross-sectional view, respectively, of the inlet side schematically showing an example of a ceramic porous filter used in the present invention. In FIG. 1, a ceramic porous filter body 1 is made of alumina, mullite, silica, cordierite, etc. and has a large number of through holes 2 arranged in parallel.
As shown in FIG. 1a, the entrance side of each through hole 2 is sealed at every other end with a ceramic sealing material 3 at the front end or the rear end. Therefore, the first
When the stock solution to be filtered is supplied from the inlet end 4 as shown by the arrow in FIG. more excreted. Fig. 1c shows an example of a shape different from that shown in a, which has a structure in which the front end of one through hole of the ceramic porous body and the rear end of the surrounding through holes are regularly and alternately sealed. The operation is the same as described above. FIG. 2a is a longitudinal cross-sectional view showing one embodiment of the filtering device 25 of the present invention, and FIG. 2b is a cross-sectional view taken along line a-a. In this embodiment, the five ceramic porous filters 1 are divided into the stock solution flow path 11 and the filtrate flow path 12 by a partition plate 13c that divides the inner cylinder 13a and the outer cylinder 13b into two almost equal parts in the vertical direction. Inner cylinder 13a in the formed double can body 13 preferably made of metal
It is stored inside. When stored, each ceramic porous filter 1 has a step A at the bottom and a stock solution supply port 14 or filtrate discharge port 15 on one side of the step A that communicates with the stock solution flow path 11 or the filtrate flow path 12. It is provided on the cylindrical can 16 via a sealing packing 17 or a protective packing 18, and a plurality of storage cylindrical cans 16 are stacked with the protective packing 18 or sealing packing 17 interposed therebetween. The storage cylinder can 16 is made of metal and has a sealing packing 1.
7 and the protective packing 18 are preferably made of an elastic body such as rubber. As described above, the ceramic porous filter bodies 1 are stacked, and between each ceramic filter body 1, a stock solution supply chamber 19 that communicates with the stock solution supply port 14 and a filtrate discharge chamber 20 that communicates with the filtrate discharge port 15 are arranged alternately. establish. Note that only the lowermost storage cylinder can 16 directly discharges the filtrate to the outside without going through the filtrate discharge port. Further, when stacking the storage cylinder cans 16, an O-ring 21 is provided at the bottom of the storage cylinder cans 16 to seal between the inner cylinder of the double can body 13 and the storage cylinder cans 16. A screw 22 is provided on the outer periphery of the lower part of the double can body 13, and is engaged with a filter holding lid 24 having a hole 23 for discharging filtrate in the center to fix the five ceramic porous filter bodies 1. The filtration device 25 is configured as follows. In the above-described filtering device 25 of the present invention, the stock solution to be filtered flows along the flow path indicated by the arrow in FIG.
That is, a part of the stock solution is supplied from the top to the uppermost ceramic porous body 1, and a part of the stock solution is supplied from the top to the top ceramic porous body 1, and the stock solution flow path 11
and are supplied to each stock solution supply chamber 19 via each stock solution supply port 14. The filtrate filtered through each ceramic porous filter body 1 is supplied to the filtrate discharge chamber 20, and is further discharged to the outside of the filtration device 25 through the filtrate discharge port 15 and the filtrate channel 12. The filtrate that has passed through the lowest ceramic porous filter 1 is directly discharged to the outside of the filtration device 25 through the holes 23. FIG. 3 is a diagram showing one embodiment of an actual filter unit 30 using the filtration device 25 of the present invention. As shown in FIG.
are attached to the unit lid 32 by the unit presser spring 31, and the filter can body 33
cover the outside of the filter unit 3.
0 is formed. When the stock solution is supplied from the inlet 34 of the filter unit 30, the filtered filtrate is discharged from the outlet 35. Among the filtration devices of the present invention described above, a five-stage ceramic porous filter shown in FIG. 2 and a filter unit using a conventional sintered metal filter shown in FIG. 4 for comparison were fabricated. We compared and measured various performances. The results are shown in Table 1.

【table】

[Table] As is clear from Table 1, compared to conventional filter elements made of sintered metal, the ceramic porous filter of the present invention has a larger specific filtration area of the elements, and each element has four filter elements. It can be seen that the weight of the filter unit constructed as an apparatus is light and the total filtration area is large, and the performance as a filter unit is significantly improved. It was also found that the service life until the filtration stop differential pressure reached 3.5 Kg/cm ² could be extended. The present invention is not limited only to the embodiments described above, and numerous modifications and changes are possible. For example, the front end or the rear end of the ceramic porous body can be regularly and alternately hermetically sealed in different shapes other than those in FIGS. 1a and 1c. (Effects of the Invention) As is clear from the detailed explanation above, according to the filtration device of the present invention, a plurality of ceramic porous filter bodies are used in multiple stages as the filter body, so that the conventional sintering It is possible to obtain a filtration device that has a larger filtration area than a metal filter, is lightweight, is inexpensive, and has an extended lifespan. Therefore, a filter unit using this filtration device is also lightweight and inexpensive, and is particularly useful as a purification device for water contaminated with radioactivity in nuclear power plants.

[Brief explanation of drawings]

Figures 1 a, b, and c schematically show a side view and longitudinal sectional view of the inlet side of a ceramic porous filter;
The figure is a longitudinal sectional view showing one embodiment of the filtration device of the present invention, FIG. 3 is a line diagram showing one embodiment of an actual filter unit using the filtration device of the present invention, and FIG. 4 is a diagram of a conventional filter unit. It is a line diagram showing one example of. 1... Ceramic porous filter body, 2... Through holes,
3... Ceramic sealing material, 4... Inlet side end,
5... Porous thin wall, 6... Outlet side end, 11...
Raw solution flow path, 12... Filtrate flow path, 13... Double can body, 14... Raw solution supply port, 15... Filtrate discharge port,
16... Storage cylinder can, 17... Seal packing, 18... Protection packing, 19... Raw solution supply chamber, 20... Filtrate discharge chamber, 21... O ring, 2
2... Screw, 23... Hole, 24... Filter holding lid, 25... Filtration device, 30... Filter unit, 31... Unit holding spring, 32... Unit lid, 33... Filter can body, 34 ...Entrance, 3
5...Exit.

Claims (1)

[Scope of Claims] 1. A ceramic porous filter body having a structure in which the front end or rear end of each through hole of a ceramic porous body having a large number of parallel through holes is regularly and alternately sealed;
A storage can having a step at the bottom for storing each ceramic porous body and a filtrate discharge port or stock solution supply port on one side of the step, and an inner cylinder and an outer cylinder are divided into two in the vertical direction. In addition to forming the stock solution flow path and the filtrate flow path,
The inner cylinder is provided with a double can body in which a plurality of storage cans are liquid-tightly stacked with packing between each storage can, and a stock solution supply chamber and a filtrate supply chamber are provided between the adjacent ceramic porous filter bodies. Discharge chambers are provided alternately, and the concentrate supply chamber is connected through the concentrate supply port and the inner cylinder to one of the concentrate flow paths divided into two between the inner cylinder and the outer cylinder of the double can body, and the filtrate is discharged. A filtration device characterized in that the chamber is connected to the other filtrate flow path which is divided into two parts between the inner cylinder and the outer cylinder through the filtrate outlet and the inner cylinder. 2. The filtration device according to claim 1, wherein the ceramic porous filter body has a structure in which the ends of every other through hole among the through holes of the ceramic porous body are alternately sealed at the front end or the rear end. 3. The filtration device according to claim 1, wherein the ceramic porous filter body has a structure in which the front end of one through-hole of the ceramic porous body and the rear end of the through-holes surrounding the through-hole are alternately sealed. . 4. The filtration device according to claim 1, wherein the packing is made of an elastic body such as rubber. 5. The filtration device according to claim 1, wherein the raw solution flow path and the filtrate flow path are divided into two sections facing each other between an inner cylinder and an outer cylinder so as to surround the ceramic porous filter body.