JPS6333679B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cartridge type filter for separating particulate solid contaminants in circulating cooling water of nuclear power plants.

Chemical corrosion reactions in nuclear power plants result in the formation of oxides or other substances on the surfaces of various structural elements, such as the inner surface of the reactor vessel, the interior of piping, or the surfaces of structures contained in the reactor core. will be formed. As a result of the flow and delamination phenomena, these oxides or other substances, in the form of microscopic particles, escape from various mechanical devices such as valves and pumps.

As the contaminants are formed and circulated in a highly radioactive atmosphere, radioactive isotopes are formed within the particulate matter. For example, alloys such as cobalt form the radioactive isotope cobalt-60. This means that filters containing significant quantities of the separated substances have become highly radioactive and therefore require special handling when handling them due to the radiation emitted by the filter material. It means that there is a problem. The filter must be surrounded by radiation protection equipment and the replacement of the filter material must be carried out remotely.

SUMMARY OF THE INVENTION An object of the present invention is to provide a filter in which the filter material can be replaced in a simple manner despite the fact that it is made of high-level radioactive material. Radioactivity levels closest to the filter may exceed 1000 millirem/hour. According to the invention, the filter is constructed as a cartridge-type filter, which allows the filter cartridge to be easily inserted and removed by means of a simple remote control device.
A filter housing having an opening and a lid at the top is adapted to receive one or more filter cartridges filled with filter material, the filter material containing contaminants contained in the reactor cooling water; Mainly captures solid particles. The filter housing is suitably cylindrical and vertically oriented. The interior of the filter housing is provided with a shoulder shaped like an inwardly directed flange and serving as a valve seat. The flanged shoulder is adapted to support one or more freely suspended filter cartridges filled with filter material. A radially outwardly projecting ring is coupled to at least one filter cartridge and is adapted to sealingly engage a flange-like shoulder of the housing and to support one or more cartridges. It is designed to. According to the embodiment to be described, said cartridge housing will be divided into two separate spaces. Contaminated water is supplied to the upper space of the cartridge, and purified water is collected in the lower space and returned to the reactor vessel. The filter is suitably included in a circuit parallel to the reactor's main cooling water flow. Only a small portion of the flow passes through this purification circuit.

Several filter cartridges can be arranged in one filter housing. The cartridges may be connected in series or in parallel. Several filter cartridges may be included in one filter group. These may be connected in parallel or in series. The filter material may be placed in the filter cartridge between the inlet and outlet strainers. Two concentric annular gear strainers may be provided in one cartridge. In this case, an annular filter bed is arranged between the strainers, through which the water flows radially. Further, a strainer may be provided at the end of the cartridge. In this case the water will pass axially through a filter bed placed between these strainers. The filter may be made of metal wire clippings. Contaminants are absorbed to a significant extent on the surface of the filter bed material. A filter cartridge is connected to the lid of the filter housing such that when the lid is lifted, the cartridge or cartridges are also lifted with the lid. During lifting by a lifting device and during movement within a radiation protection device, the lid provides an excellent radiation protection barrier against upward radiation. A spring mechanism is provided between the lid and the filter cartridge to increase the contact force between the flanged shoulder in the filter housing and the cooperative ring supporting the cartridge or cartridges. is provided.

The present invention will be described in detail below with reference to the accompanying drawings.

In the drawing, 1 is a concrete wall 2 and a lid 3
It shows the space formed by The lid consists of an outer annular part 3a and an inner part 3b. The space 1 accommodates a filter device 4. The filter device is connected to the housing 5 by a cylindrical filter housing 5 and bolts 9.
and a removable lid 6 attached to the holder. The filter housing is connected by a supply pipe 7 and a return pipe 8 to the primary cooling water system of the nuclear reactor. Since the filter device 4 is connected to the primary cooling water system of the reactor, this filter device can withstand the same pressure as the primary cooling water system, typically about 70 bar (70 kg/cm ² ) of a boiling water reactor. You have to have a structure that will help you get it. It is also suitable for the filter device to be adapted to steam temperatures of approximately 300 degrees Celsius. Two filter cartridges 10, 11 are mounted within the filter housing. The upper cartridge 10 is connected to an inlet portion 12 for adjusting the flow direction of the water flow at the inlet of the cartridge 10. Said inlet section 12 is connected to the lid 6. When pulling out the cartridges 10, 11, remove the concrete cover 3b and as shown in FIG.
a radiation protection device 13 is placed above the opening 14;
A rod 15 is connected to the lid 6 and the entire unit consisting of the lid 6, the inlet section 12 and the cartridges 10, 11 is lifted into the radiation protection device 13. Said lid 6 forms a radiation protection device against upward radiation. The apparatus 13 and its contents are removed, the cartridges 10, 11 and the inlet section 12 are separated, the cartridges 10, 11 are packed in concrete and disposed of in a conventional manner.

As best shown in FIGS. 3, 4 and 5, the upper portion of the filter housing 5 has a larger diameter than the lower portion. At the point where the diameter changes, a radially inwardly directed flange-like shoulder 16 is formed, which serves as a valve seat and is formed with an inclined surface 17 similar to a valve seat.
The upper cartridge 10 is provided with a ring 20 having a spherical surface 21 in sealing relationship with the sloped surface 17 of the shoulder 16 in the changing diameter portion of the housing 5. Said surfaces 17 and 21 are in direct contact, providing a sealing relationship between these two metal surfaces. This ring 20 and cartridge 10
Accordingly, the filter housing is divided into two spaces 22 and 23. The cartridges 10, 11 are suspended from this ring 20 and hang freely within the filter housing 5. The design of the surfaces 17, 21 is such that they cooperate with each other and are in a sealing relationship with each other so that the filter cartridge 1
0,11 are automatically centered upon insertion, ensuring uniform and reliable contact between said surfaces and providing a reliable and good seal without the use of sealing rings of any kind. You can get sex. By reducing the acute angle of the conical surface 17, the surface pressure can be increased to the desired level for a good seal. The supply pipe 7 opens into the upper space 22 and the return pipe 8 opens into the lower space 23. The upper cartridge 10 has a sleeve 24 with flanges 25, 26.
including. The lower cartridge 11 is a sleeve 27
, a flange 25a, and an annular bottom portion 28. The inlet portion 12 is provided with flanges 30,31. The cartridges 10 and 11 are connected by flanges 26 and 25a and bolts 32. The inlet portion 12 and cartridge 10 are connected by flanges 25, 30 and bolts 33. The inlet section 12 is connected to the lid 6 by a flange 31 and bolts 34. The bolts 32, 33 are welded to the flanges 25, 25a, and the flanges 26, 25a are welded to the flanges 25, 25a.
30 is provided with an opening for the bolt head and a groove for the bolt shaft. The bolt head is inserted into the opening and the cartridge is then rotated to insert the bolt shaft into the groove. These coupling devices are therefore of the plug-in type. Said lid 6
A spring 29 as a spring mechanism is provided between and the flange 31, and this spring 29 presses the entire cartridge against the inclined surface 17 of the shoulder 16. The filter material 35 is arranged between two annular concentric strainers 36 and 37, between the plate 38 and the ring 40, and between the ring 41 and the bottom 28, respectively. As shown in FIGS. 5 and 6, the strainer includes rings 42, 43 and spacers 44, 45, respectively.
It is made up of. The rings 42, 43 and spacers 44, 45 are held together by bolts 46. The thickness of the gap between these is chosen to be somewhat smaller than the particle size of the filter material 35. If you use wire clipping with a length of 0.4 mm and a diameter of 0.4 mm, the thickness
It is appropriate to use a 0.2 mm spacer.

In one embodiment of the filter illustrated in FIG. 3, water enters the space 22 from the supply pipe 7, thence into the inlet section 12, the space 47, and descends between the sleeves 24, 27 and the strainer 36. entering the gaps 48, 50 and passing radially through the filling area of filter material 35 into the central space 51;
It descends into the space 23 and exits through the return pipe 8.

In the filter of another embodiment illustrated in FIG. 4, the lids 51, 52 and the bottom portions 53, 54 are
It includes strainers 55, 57 and 56, 58. Filter material 60 is present between the strainers. The lid 51 and the bottom 53 are connected by a sleeve 61, and the sleeve 61 and the sleeve 2
A gap 62 is formed between the two. Additionally, the lid 52 and the bottom 54 are connected to the sleeves 27 and 63.
and the filter material 60
An annular space filled with is formed. Note that the sleeve 63 forms an axial flow path 64 in the center. The bottom 65 of the filter cartridge 10 is provided with a tubular sleeve 66 and the lid 5
2 is provided with a cylindrical joint 67, so that the cartridges 10 and 11 are connected to each other, and a space 68 within the cartridge 10 and the flow path 64 passing through the cartridge 11 are connected.

The water passes through the strainer 55 and filter material 6
It flows axially through the filling area of 0 and enters the space 68 through the strainer 56 and from there into the channel 64 and into the space 23. The water in other parts is space 47
It enters the gap 62 and descends to the strainer 5.
7 into the cartridge 11 and through the filling area of filter material 60 and the strainer 58 into the space 23.

In this filter, a filter cartridge having a different shape and material from the filter cartridge shown in this embodiment may be used. For example, the filter cartridge may be configured as a flat filter of different types.

[Brief explanation of the drawing]

Figure 1 shows the filter and how it is placed in a nuclear power plant; Figure 2 shows the removal of the filter cartridge;
4 and 4 show two different embodiments of the filter, FIG. 5 an enlarged view in vertical section, and FIG.
The figure is a cross-sectional view of a filter cartridge of the shape shown in FIG. 3. In the figure, 5...filter housing, 6
... Lid, 10, 11 ... Filter cartridge, 16 ... Flange-shaped shoulder, 17 ... Conical surface,
20...Ring, 21...Spherical surface, 22, 23...
...Space, 35,60...Filter floor, 36,3
7, 55, 56, 57, 58...Strainer.

Claims (1)

Claims: 1. A device for separating radioactive particles from reactor cooling water of a nuclear power plant, connected to a cooling water circuit and having a filter housing for one or more filter cartridges. It is a cartridge type filter, and the filter housing 5 has an opening at the top that can be closed with a lid 6, and the filter housing 5 has a particulate-trapping filter material 35 on the top and is freely suspended. An inwardly directed flange-like shoulder 16 in the form of a valve seat is formed and configured to support the filter cartridge 10, 11 which is attached to the filter cartridge. The unit includes a ring 20 adapted to engage in a fluid-tight manner with said flange-like shoulder 16 and cooperate with said shoulder 16 to divide the interior of the filter housing 5 into two separate spaces 22, 23. is formed, and the divided space 2
2, 23 are connected via separate conduits 7, 8 to the cooling water circuit of the reactor; said lid 6 of filter housing 5 and said cartridges 10, 11 are connected to said cartridges 10, 11;
11 is attached to the cartridge 10,1 with respect to the lid 6.
between the lid 6 and the cartridges 10, 11, when the lid 6 is set in position to close the top opening of the housing 5; A cartridge type filter in which a spring mechanism 29 is provided to press the ring 20 against the shoulder 16 of the housing 5. 2. The ring 20 supporting the cartridge filter 4 is brought into direct contact with the seat-shaped shoulder 16 of the filter housing 5, so that a metal contact is formed between the ring 20 and the shoulder 16. The cartridge type filter according to item 1 of the range. 3. A cartridge-type filter according to claim 1, wherein the seat-shaped flange-like shoulder 16 of the filter housing 5 is formed with a moderately conical surface 17 inclined inwards. 4. The support ring 20 connected to the filter cartridge is formed with a spherical surface 21 configured to cooperate with the inclined surface 17 of the flange-like shoulder 16 of the filter housing. Cartridge type filter described in section. 5 The lid 6 of the filter housing is provided with a gripping mechanism for a lifting device, so that when the lid 6 is lifted, the cartridges 10, 11 are lifted together with the lid 6.
A cartridge-type filter according to any one of claims 1 to 4, in which the filters 0 and 11 are interconnected. 6. Several filter cartridges 10, 11 are housed in one filter housing 5,
2. A cartridge type filter according to claim 1, wherein said filter cartridges 10, 11 are connected in parallel or in series. 7. The cartridge type filter according to claim 1, wherein one filter group includes several cartridge type filters connected in parallel or in series. 8. The filter cartridges 10, 11 have two concentric gap strainers 36, 37, and a filter bed 35 is disposed in the annular space between the strainers 36, 37. 2. A cartridge-type filter according to claim 1, wherein the cartridge-type filter is configured to allow water to flow radially therethrough. 9 Gap strainers 55, 56, 57, 58 are provided at the ends of the filter cartridges 10, 11, and the filter bed 6 is provided between the strainers.
2. A cartridge-type filter as claimed in claim 1, in which a filter bed (60) is housed and configured to allow water to flow axially through said filter bed (60). 10. Claim 8 wherein the filter material of the filter beds 35, 60 is made of wire clipping.
9. The cartridge type filter according to item 1 or item 9.