JP4863914B2 - Sealing device for metal contacts - Google Patents

Description

The present invention relates to a water seal system metal contact in the equipment there is a solution to the gap between the contact portion of the metal member, in particular water seal device metal contact capable of suppressing crevice corrosion of the contact portion Related.

  When different types of metals are fixed in contact with each other in an aqueous solution, a potential difference occurs between the metals, and corrosion progresses on the contact surface. Further, even if the same type of metal is used, a difference in oxygen concentration in the aqueous solution (oxygen concentration cell) or aeration difference corrosion (crevice corrosion) due to foreign matter in the aqueous solution occurs. When the above-mentioned corrosion occurs in components such as water turbines used for hydroelectric power generation, the corroded portion is corrected and repaired by machining or the like, and the corrected and corrected components are reused.

  FIG. 5 shows an example of a sealing device for a metal contact portion in a conventional device. In FIG. 5, the code | symbol 1 has shown one metal member, and the code | symbol 2 has shown the other metal member. The end surface 1a of the metal member 1 and the end surface 2a of the metal member 2 are in contact with each other, and a seal member 3 is provided at the contact portion. The inside of the metal member 1 and the metal member 2 is filled with the aqueous solution 4, and the aqueous solution 4 exists in the gap between the end surface 1a and the end surface 2a. When the contact portion between the end surface 1a and the end surface 2a is corroded due to crevice corrosion, the end surface 1a and the end surface 2a are corrected by machining or the like, and the metal member 1 and the metal member 2 are reused.

For example, Patent Document 1 is known as an example of a technique for suppressing corrosion of a metal member by an aqueous solution. Patent Document 1 relates to a corrosion resistant structure of a valve provided in a pipeline, and a liner made of a corrosion resistant metal material is fixed to the inner peripheral surface of a valve box by plug welding.
Japanese Utility Model Publication No. 6-16791

  However, in order to maintain the sealing effect, there is a limit to the amount of erosion of the corroded part in the metal contact part. There is a problem that you have to replace it completely. In particular, in water turbines for hydroelectric power generation, the metal member to be replaced becomes large, and it is very expensive to replace the metal member completely because of some crevice corrosion.

Therefore, the present invention can suppress the progress of crevice corrosion at the contact portion of the metal member, and even when the correction amount of the corroded portion reaches the limit, the metal that does not need to be replaced completely. It aims at providing the sealing device of a contact part.

In order to achieve the above object, according to the first aspect of the present invention, in an apparatus in which an aqueous solution exists in a gap between contact portions of a metal member, one metal member of the contact portion has higher corrosion resistance than the metal member. attaching a first liner having, on the other metal member of the contact part, only attaching the second liner in contact with said first liner having a higher corrosion resistance than the metal member, and said first The liner and the second liner are a water sealing device for a metal contact portion, wherein the liner and the second liner are detachably fixed to the metal members by fastening means .

According to the first aspect of the present invention, since the first liner and the second liner having higher corrosion resistance than the metal member are in contact with each other, the progress of crevice corrosion is suppressed as compared with the case where the metal members are in contact with each other. can do. Further, when the crevice corrosion of the liner progresses and the amount of correction of the liner is limited, it is only necessary to replace the liner, and the cost can be reduced as compared with the case where the metal member is completely replaced.

Furthermore, since the liner can be detachably fixed to the metal member by the fastening means, the liner can be easily attached to or detached from the metal member, and the grinder processing or the like of the liner attachment surface becomes unnecessary.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 shows an embodiment of the present invention. In FIG. 1, the code | symbol 11 has shown the 1st metal member, and the code | symbol 12 has shown the 2nd metal member. The 1st metal member 11 and the 2nd metal member 12 are comprised from the same kind of material, for example, are comprised from the carbon steel cast steel product (SC). The outer surface 11a of the first metal member 11 is formed as a flat surface extending in the horizontal direction. Similarly, the outer surface 12 a of the second metal member 12 is formed as a flat surface extending in the horizontal direction and has the same height as the outer surface 11 a of the first metal member 11. A space is formed inside the first metal member 11 and the second metal member 12 by an inner surface 11b and an inner surface 12b, and the space is filled with water 13 as an aqueous solution. The end portion of the first metal member 11 and the end portion of the second metal member 12 face each other, and the end surface 11c of the first metal member 11 and the end surface 12c of the second metal member 12 are both formed in a stepped shape. Has been.

  A first liner 14 is attached to the end surface 11 c of the first metal member 11. The first liner 14 has higher corrosion resistance than the metal member 11 and is made of, for example, stainless steel (SUS304, SUS316, etc.) that is resistant to crevice corrosion. The first liner 14 has a substantially L-shaped cross section. In the first liner 14, the outer surface 14 a is formed at the same height as the outer surface 11 a of the metal member 11, and the inner surface 14 b is also formed at the same height as the inner surface 11 b of the metal member 11. An end face 14c facing the end face 12c of the metal member 12 is formed on one side of the first liner 14 whose cross-sectional shape is L-shaped. The end surface 14c is formed on a vertical surface that is polished with high accuracy. The other side of the first liner 14 is located on the outer surface 11 a side of the first metal member 11. The first liner 14 is fixed to the end portion of the first metal member 11 by a bolt 15 as a fastening means screwed to the first metal member 11. The first liner 14 is formed with a bolt hole 14d into which the bolt 15 is inserted.

  A second liner 16 is attached to the end surface 12 c of the second metal member 12. The second liner 16 is made of the same metal material as the first liner 14. The second liner 16 has a substantially L-shaped cross section. The second liner 16 has an outer surface 16a formed at the same height as the outer surface 12a of the second metal member 12, and an inner surface 16b formed at the same height as the inner surface 12b of the second metal member 12. ing. An end face 16 c that faces the end face 11 c of the first metal member 11 is formed on one side of the second liner 16 having an L-shaped cross section. The end surface 16c is formed on a vertical surface that is polished with high accuracy. The other side of the second liner 16 is located on the outer surface 12 a side of the second metal member 12. The second liner 16 is fixed to the end of the metal member 12 by a bolt 15 that is screwed to the metal member 12. The second liner 16 is formed with a bolt hole 16d into which the bolt 15 is inserted.

  As shown in FIG. 1, the end surface 14c of the first liner 14 and the end surface 16c of the second liner 16 are in contact with each other over the entire surface. A seal member 17 that prevents the aqueous solution 13 from leaking to the outside is interposed at a contact portion between the end surface 14c and the end surface 16c. A minute gap is formed at the contact portion between the end face 14c of the first liner 14 and the end face 16c of the second liner 16, and the aqueous solution 13 is present in this gap.

  In this embodiment, in order to make the end surface 14c of the first liner 14 and the end surface 16c of the second liner 16 statically fit (fitting without gaps), the metal members 11, 12 and the liners 14, 16 are The shape and dimensional accuracy are set in consideration of this. That is, in the aspect of the present embodiment, in order to make the gap between the end face 14c and the end face 16c close to zero, the step portion of the first metal member 11 and the first liner 14 in contact with the step portion. The back surface is processed with high accuracy, and the stepped portion of the second metal member 12 and the back surface of the second liner 16 contacting the stepped portion are processed with high accuracy. In this manner, not only the end surface 14c and the end surface 16c are processed with high accuracy, but also the dimensional accuracy of the portion to which the liners 14 and 16 are attached is increased, thereby realizing the static alignment between the end surface 14c and the end surface 16c.

  Next, a method for sealing the metal contact portion in the present embodiment will be described. The aqueous solution 13 filled inside the metal member 11 and the metal member 12 penetrates into a minute gap formed between the end surface 14c and the end surface 16c by capillary action. Therefore, crevice corrosion occurs in the contact portion between the first liner 14 and the second liner 16 due to the reaction with the aqueous solution 13, and a corroded portion is generated on the end face 14c and the end face 16c due to long-term use of the equipment. The Since the first liner 14 and the second liner 16 have higher corrosion resistance than the metal members 11, 12, the progress of crevice corrosion can be suppressed more than when the metal members 11, 12 contact each other. it can. Therefore, by using the first liner 14 and the second liner 16, it is possible to reduce the number of repairs of equipment due to crevice corrosion as compared with the conventional case.

  When crevice corrosion of the first liner 14 and the second liner 16 has progressed, the first liner 14 is removed from the metal member 11, and the second liner 16 is also removed from the metal member 12. The end surface 14c of the first liner 14 and the end surface 16c of the second liner 16 where crevice corrosion has occurred are corrected by machining or the like to remove the corroded portion. The corrected first liner 14 and second liner 16 are attached to the metal members 11 and 12 again for reuse. In this case, the gap at the contact site is enlarged by the correction amount. However, since the first liner 14 bolt hole 14d is formed as a long hole, the first liner 14 is directed toward the second liner 16. Can be moved. Thereby, even when the liner is trimmed, the end surface 14c of the first liner 14 and the end surface 16c of the second liner 16 can be brought into close contact with each other, and a high sealing effect can be maintained. Further, when the amount of correction of the first liner 14 and the second liner 16 is limited, only the first liner 14 and the second liner 16 need to be replaced. Costs can be reduced compared to the case of replacement.

  The first liner 14 and the second liner 16 are L-shaped, and can be attached to the metal members 11 and 12 by being pushed in from the exposed surface side, and bolts 15 as fastening means are provided on the exposed surface side. It can fix to the metal members 11 and 12 by tightening. On the other hand, the liners 14 and 16 can be removed by removing the bolt 15 from the exposed surface side and pulling it out from the exposed surface side. Thus, since the liners 14 and 16 can be attached and detached from the exposed surface side, it is not necessary to disassemble the equipment constituted by the metal members 11 and 12 and can be easily and quickly attached and detached. Furthermore, in the case where the end faces 14c and 16c are fixed from the end faces 14c and 16c side of the liners 14 and 16 by countersunk welding, the end faces 14c and 16c need to be processed by a grinder or the like. Since it fastens from the side, such a process becomes unnecessary. The first metal member 11 and the second metal member 12 are repaired at the equipment manufacturing factory, so that the liner can be attached by processing at the factory, and the metal member 11 on the aqueous solution 13 side, With respect to the contact surface between the liner 12 and the liners 14 and 16, it is possible to eliminate a gap portion by welding or the like as will be described later.

(Embodiment 2)
FIG. 2 shows an embodiment of the present invention. This embodiment is different from Embodiment 1 only in the presence or absence of a welded portion, and other configurations are the same as in Embodiment 1. Therefore, the same reference numerals as those in Embodiment 1 are applied to the corresponding portions. Description of the part is omitted. The same applies to other embodiments described later.

  In FIG. 2, the first liner 14 and the second liner 16 are attached with the end face 14c and the end face 16c being in close contact with each other. A gap S <b> 1 between the inner surface 14 b of the first liner 14 and the inner surface 11 b of the metal member 11 is sealed by the welded portion 18. The welded portion 18 is formed, for example, by arc welding the metal member 11 and the first liner 14. A gap S <b> 2 between the inner surface 16 b of the second liner 16 and the inner surface 12 b of the metal member 12 is sealed by the welded portion 19. The welded portion 19 is formed, for example, by arc welding the metal member 12 and the second liner 16.

  In the embodiment 2 configured as described above, the gap S1 and the gap S2 are sealed by the welds 18 and 19, so that the aqueous solution 13 can be prevented from entering the gaps S1 and S2, and the gaps S1 and S2 can be prevented from entering. Generation of crevice corrosion is prevented. Therefore, the number of repairs of equipment due to crevice corrosion can be reduced as compared with Embodiment 1.

(Embodiment 3)
FIG. 3 shows an embodiment of the present invention. In the present embodiment, only the materials of the first metal member 11 and the second metal member 12 are different from those in the first embodiment. As shown in FIG. 3, the first liner 24 and the second liner 26 are made of hard rubber made of an insulator having higher corrosion resistance than the first metal member 11 and the second metal member 12. Yes. A first liner 24 is attached to the end of the first metal member 11.

  The first liner 24 has an outer surface 24 a formed at the same height as the outer surface 11 a of the first metal member 11, and an inner surface 24 b is formed at the same height as the inner surface 11 b of the first metal member 11. ing. On one side of the first liner 24 whose cross-sectional shape is L-shaped, an end face 24c that faces the end of the second metal member 12 is formed. The end surface 24c is formed in a vertical surface. The other side of the first liner 24 is located on the outer surface 11 a side of the first metal member 11 and is fixed by a bolt 15 screwed into the first metal member 11. The first liner 24 is formed with a bolt hole 24d into which the bolt 15 is inserted.

  A second liner 26 is attached to the end of the second metal member 12. The second liner 26 has a substantially L-shaped cross section. In the second liner 26, the outer surface 26 a is formed at the same height as the outer surface 12 a of the metal member 12, and the inner surface 26 b is also formed at the same height as the inner surface 12 b of the second metal member 12. On one side of the second liner 26 whose cross-sectional shape is L-shaped, an end face 26c facing the end of the first metal member 11 is formed. The end surface 26c is formed in a vertical surface. The other side of the second liner 26 is located on the outer surface 12 a side of the second metal member 12 and is fixed by a bolt 15 screwed into the second metal member 12. The second liner 26 is formed with a bolt hole 26 d into which the bolt 15 is inserted.

  As shown in FIG. 3, the end surface 24c of the first liner 24 and the end surface 26c of the second liner 26 are in contact with each other over the entire surface. A seal member 17 is interposed at a contact portion between the end surface 24c and the end surface 26c. The back surface of the first liner 24 is in contact with the end portion of the metal member 11, and the back surface of the second liner 26 is in contact with the end portion of the metal member 12. A minute gap is formed at the contact portion between the end face 24c of the first liner 24 and the end face 26c of the second liner 26, and the aqueous solution 13 is present in this gap. As will be described later, the first liner 24 and the second liner 26 are elastically fixed in a compressed state. Therefore, the dimensions of the first liner 24 and the second liner 26 are the compression width. It is set in consideration of.

  In the present embodiment configured as described above, the first liner 24 and the second liner 26 are made of hard rubber, and therefore the gap between the end surface 24c and the end surface 26c is set to substantially zero. Can do. That is, since the first liner 24 and the second liner 26 can be elastically deformed, the end surface 24c and the end surface 26c remain by fixing the first liner 24 with the second liner 26 pressed against each other. The adhesion state can be maintained by the stress. Further, due to this residual stress, the back surface of the first liner 24 can be kept in close contact with the first metal member 11, and the back surface of the second liner 26 can also be kept in close contact with the second metal member 12. be able to. Therefore, in the case of devices in which an excessive load does not act on the first liner 24 and the second liner 26, the sealing effect of the metal contact portion can be remarkably enhanced by adopting the configuration of this embodiment. .

Embodiment 4
FIG. 4 shows an embodiment of the present invention, and particularly shows a case where the present invention is applied to a hydroelectric turbine. In FIG. 4, reference numeral 30 indicates a Francis turbine, and the runner 31 of the Francis turbine 30 is filled with high-pressure water (not shown) as an aqueous solution. In the vicinity of the runner 31, a first component member 33 and a second component member 34 are provided as parts constituting the Francis turbine 30. The runner 31 is attached to the first component member 33 via a bolt 32. A first metal member 35 is provided at a portion adjacent to the first component member 33. A second metal member 36 is attached to the second component member 34. The first metal member 35 and the second metal member 36 are made of the same metal material.

  A first liner 37 having an L-shaped cross section is fixed by a bolt 39 at one end of the first metal member 35 close to the runner 31. A second liner 38 having an L-shaped cross section is fixed by a bolt 39 at one end of the second metal member 36 near the runner 31. One end of the first metal member 35 and one end of the second metal member 36 are connected via a first liner 37 and a second liner 38. One side of the first liner 37 and one side of the second liner 38 are in contact with each other with a sufficient area. The first liner 37 and the second liner 38 are made of the same metal material, and have higher corrosion resistance than the first metal member 35 and the second metal member 36.

  A first liner 40 having an L-shaped cross-section is fixed to the other end of the first metal member 35 by a bolt 42. A second liner 42 having an L-shaped cross section is fixed to the other end of the second metal member 36 by a bolt 42. The other end of the first metal member 35 and the other end of the second metal member 36 are connected via a first liner 40 and a second liner 41. One side of the first liner 40 and one side of the second liner 41 are in contact with each other with a sufficient area. The first liner 40 and the second liner 41 are made of the same metal material and have higher corrosion resistance than the metal member 35 and the metal member 36.

  In this embodiment configured as described above, the high-pressure water flowing from the runner 31 of the Francis turbine 30 enters the gap between the contact portions of the first metal member 35 and the second metal member 36, and in the contact portion. Crevice corrosion occurs. Since one end portion of the first metal member 35 and one end portion of the second metal member 36 are in contact with each other via the first liner 37 and the second liner 38 having high corrosion resistance, the gap The progress of corrosion is suppressed. Similarly, the other end portion of the first metal member 35 and the other end portion of the second metal member 36 are also in contact with each other via the first liner 40 and the second liner 41 having high corrosion resistance. Therefore, the progress of crevice corrosion is suppressed. As described above, the Francis turbine 30 is a large-sized device used for hydroelectric power generation, and by adopting a liner having high corrosion resistance, the number of repairs of the large metal members 35 and 36 can be reduced, and the repair cost is greatly reduced. Can be planned.

  Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to the present embodiment, and even if there is a design change or the like without departing from the gist of the present invention, Included in the invention. For example, in Embodiment 4, the example applied to the Francis turbine 30 for hydroelectric power generation has been shown, but the application range is not limited to the turbine, and is applicable to any equipment that requires a sealing effect such as piping parts. Is possible. Further, as shown in the third embodiment, the first liner 24 and the second liner 26 may be non-metallic materials. Furthermore, although the aqueous solution 13 existing in the gap between the contact portions of the metal member 11 and the metal member 12 is water, an aqueous solution in which other substances are dissolved may be used.

It is sectional drawing of the water sealing apparatus of the metal contact part concerning Embodiment 1 of this invention. It is sectional drawing of the water sealing apparatus of the metal contact part concerning Embodiment 2 of this invention. It is sectional drawing of the water sealing apparatus of the metal contact part concerning Embodiment 3 of this invention. It is sectional drawing of the water sealing apparatus of the metal contact part concerning Embodiment 4 of this invention. It is sectional drawing of the conventional sealing device of a metal contact part.

Explanation of symbols

11 Metal member 12 Metal member 13 Water (aqueous solution)
14 first liner 14d bolt hole 16 second liner 16d bolt hole 24 first liner 24d bolt hole 26 second liner 26d bolt hole 30 Francis turbine 31 runner 35 metal member 36 metal member 37 first liner 38 first Second liner 40 First liner 41 Second liner

Claims (1)

In an apparatus in which an aqueous solution exists in a gap between contact portions of a metal member, a first liner having higher corrosion resistance than the metal member is attached to one metal member of the contact portion, and the other metal member of the contact portion is attached. in, only attach the second liner in contact with said first liner having a higher corrosion resistance than the metal member, and said first liner and second liner, wherein each metal member by a fastening means A sealing device for a metal contact portion, which is fixed so as to be removable .

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