JP2006083422A - Electrolytic corrosion protection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolytic corrosion protection device which is used for a compact heat exchanger or the like, and can remarkably prolong the service life of each sacrificial anode easily and inexpensively. <P>SOLUTION: In the electrolytic corrosion protection device where planar sacrificial anodes each having a hollow part are fitted to the body to be subjected to corrosion protection with a bolt and a nut, and the void in each hollow part is filled with a filler, the planar sacrificial anodes are composed of stacked first and second planar sacrificial anodes or first to third planar sacrificial anodes, and the planar sacrificial anodes are fixed using a fitting bolt having a nut part and bolt part and are fitted to the body to be subjected to corrosion protection. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an anticorrosion device, and more particularly, to an anticorrosion device that is used in a small heat exchanger or the like and has a long-lived current-carrying anode easily and inexpensively.

  Since a small heat exchanger or the like for an oil refining plant is in contact with an electrolyte such as seawater or industrial water, a corrosion current is generated, and the metal constituting the small heat exchanger is corroded. In order to prevent this corrosion, an anti-corrosion method using an galvanic anode method is used in addition to an anti-corrosion method using an external power source to prevent corrosion using an external power source. In this galvanic anode type anticorrosion method, conventionally, a plate-shaped galvanic anode having a hollow part (thickness 30 to 50 mm) is fixed and attached to the body to be protected with bolts and nuts in the hollow part, A material in which a gap is filled with a filler is used, but there is a limit to the amount of anode, which causes a situation where the anode is consumed during the periodical inspection of the plant. For this reason, the life extension of the galvanic anode has been particularly directed.

  Conventionally, various proposals have been made for galvanic anodes used in such small heat exchangers. For example, Patent Document 1 (Japanese Patent Laid-Open No. 58-78097) describes a seawater heat exchanger in which a step is provided at the lower end portion of a mounting bolt of a sacrificial anode plate to prevent peeling of the lining material during anode replacement. Yes. However, this seawater heat exchanger needs to line the water chamber after welding the mounting bolts, which is troublesome. Usually, in order to avoid such trouble, an anode is attached by welding a mounting bolt to a partition plate in a non-lining water chamber.

  Further, Patent Document 2 (the full specification of Japanese Utility Model Publication No. 49-17904) describes that a large anticorrosion current can be generated by providing a large number of galvanic anodes at a predetermined interval and floating from the mounting surface. ing. However, this anticorrosion device adversely affects the flow of cooling water because the galvanic anode is separated from the partition plate.

  Patent Document 3 (Japanese Patent Application Laid-Open No. 51-5651) describes a corrosion prevention method for a heat exchanger in which the tube plate of the heat exchanger is composed of a composite metal plate with an galvanic anode material. Keep the potential of the object to be protected at the anticorrosion potential. It is supposed to extend the life of the anode. However, since this anticorrosion method reduces the efficiency of the heat exchanger, such a composite metal plate is not substantially used.

  In the apparatus or method described in Patent Documents 1 to 3 as described above, it is difficult to essentially extend the life of the galvanic anode.

JP 58-78097 A Japanese Utility Model Publication No. 49-17904 Japanese Patent Laid-Open No. 51-5651

  Currently, in order to extend the life of the galvanic anode, the galvanic anode attached to the heat exchanger is added, or the plate-shaped galvanic anode with a plate thickness is specially manufactured. It was.

  However, an increase in the number of galvanic anodes requires a lot of processing to a heat exchanger or the like, resulting in an increase in cost and labor.

  On the other hand, special production of a plate-like galvanic anode having a plate thickness requires cost and time for producing the anode. In addition, when replacing the current-carrying anode, the bolt hole for fixing the plate-shaped current-carrying anode is deep, making it difficult to remove the filler.

  As described above, no cathodic protection device has been obtained that can extend the life of the galvanic anode easily and inexpensively.

  Accordingly, an object of the present invention is to provide an anticorrosion apparatus that can be used in a small heat exchanger or the like and can greatly extend the life of a current-carrying anode at a low cost.

  As a result of the study, the present inventors have found that the above-described object can be achieved by mounting a standard type plate-like galvanic anode that has been conventionally used in two or three steps using a specific mounting bolt. The present invention has been reached.

  That is, the present invention relates to an anticorrosion apparatus in which a plate-like galvanic anode having a hollow portion is attached to an object to be protected using bolts and nuts in the hollow portion, and the voids of the hollow portion are filled with a filler. The plate-like current anode is composed of a first-stage and second-stage plate-like current anode or a first to third-stage plate-like current anode that are superposed on each other. The present invention provides an anticorrosion device characterized in that it is fixed by using a mounting bolt having it and attached to the subject to be protected.

  Further, in the present invention, the plate-like current anode is composed of a first-stage and second-stage plate-like current anode, and the first-stage plate-like current anode is fixed with a bolt and a nut portion of a mounting bolt, The above-mentioned cathodic protection device is provided for fixing the second-stage plate-like galvanic anode with a bolt portion and a nut of a mounting bolt.

  In the present invention, the plate-like galvanic anode comprises first to third-stage plate-like galvanic anodes, and the first-stage plate-like galvanic anode is fixed with a bolt and a nut portion of the first mounting bolt, The second-stage plate-like current-carrying anode is fixed with a bolt part of a first attachment bolt and a nut part of a second-attachment bolt, and the third-stage plate-like current-carrying anode is fixed with a bolt part of a second attachment bolt. The above-described cathodic protection device fixed with a nut is provided.

  Moreover, this invention provides the said anti-corrosion apparatus with which the said 1st step and a 2nd step plate-shaped galvanic anode or a 1st-3rd step | paragraph plate-like galvanic anode are the same shape.

  The present invention also provides the above-described cathodic protection device in which the above-mentioned corrosion-protected body is a small heat exchanger.

  The electro-corrosion protection apparatus according to the present invention can double the number of attachments to one place by attaching two or three steps of a standard type plate-like current-feeding anode that has been conventionally used with attachment bolts. Without the need for additional mounting bolts and the like, and without using a custom-made galvanic anode, it is possible to easily significantly increase the cathodic protection period, that is, to prolong the life of the galvanic anode.

Hereinafter, the best mode for carrying out the present invention will be described in detail.
FIG. 1 is a schematic cross-sectional view showing an embodiment of the cathodic protection device 1 according to the present invention.

  In FIG. 1, the first-stage plate-like galvanic anode 2 a is fixed to the corrosion-protected body 7 by being fixed by a bolt 3 and a nut portion of a mounting bolt 4 in the hollow portion. And the filler 6 is filled in the space | gap of the hollow part of the 1st step-plate-like galvanic anode 2a.

  The second-stage plate-like current-carrying anode 2b is arranged so as to be superimposed on the plate-like current-carrying anode 2a, and is fixed by the bolt part of the mounting bolt 4 and the nut 5 at the hollow part. The gap is filled with the filler 6 in the same manner as described above.

  The plate-like galvanic anodes 2a and 2b used here have hollow portions as described above, and are made of an aluminum alloy, a zinc alloy, a magnesium alloy or the like. The plate-like galvanic anodes 2a and 2b may have different thicknesses. However, in consideration of economy, it is desirable to use a standard type having the same shape with a thickness of 30 to 50 mm. .

  Moreover, a small heat exchanger is mentioned as the to-be-corroded body 7 in which the cathodic protection apparatus 1 which concerns on this invention is installed, and it is a cylindrical multi-tube heat exchanger especially. The material is copper alloy, double layer stainless steel, titanium or the like, and the cooling water used in the heat exchanger is seawater, industrial water or the like.

  A side sectional view of the mounting bolt 4 used in the present invention is shown in FIG. 2, and a transverse sectional view thereof is shown in FIG. As shown in FIGS. 2 and 3, the mounting bolt 4 is composed of a hole portion 4a, a nut portion 4b, and a bolt portion 4c, and when a standard type plate-like anode (thickness 40 mm) 2a, 2b is used. The nut portion 4b of the mounting bolt 4 has an integrated shape of 40 mm and the bolt portion 4c has an integral shape of 30 mm, and the hole portion 4a (completely threaded portion) is 30 mm.

  Next, a method for mounting the plate-like galvanic anodes 2a and 2b using the mounting bolt 4 will be described in detail. First, the existing bolt 3 is installed in the hollow portion of the first plate-like galvanic anode 2a, the bolt 3 is screwed into the hole portion 4a of the mounting bolt 4, and is fastened and fixed by the nut portion 4b. The gap is filled with the filler 6. The bolt 3 is fixed to the corrosion-protected body 7 in advance.

  Next, the bolt portion 4c of the mounting bolt 4 is installed in the hollow portion of the second step plate-like galvanic anode 2b, and is fastened and fixed with the existing nut 5, and the void in the hollow portion is filled with the filler 6.

  In this way, the two-stage plate-like anodes 2a and 2b are installed on the body 7 to be protected, and the anode mounting amount is doubled. As described above, the thickness of the plate-like current anodes 2a and 2b can be changed, and a part of the attached current-flow anode can be a two-stage plate-like current anode. For this reason, fine adjustment of 1.2 times, 1.5 times, etc. of the anode mounting amount is possible.

  Further, when the plate-like current-carrying electrode is made into the first to third three-stage, the first and second mounting bolts are used, and the first-stage plate-like current anode is connected to the existing bolt and the first attachment. The second step plate-like current anode is fixed with the bolt portion of the first mounting bolt and the nut portion of the second attachment bolt, and the third step plate-like current anode is secondly fixed. It is fixed with a bolt portion of the mounting bolt and an existing nut (not shown). In this case, the amount of the galvanic anode is tripled. Although it is possible to have four or more plate-like galvanic anodes, it is not practical considering the strength of the mounting bolts.

  As described above, the cathodic protection device according to the present invention can extend the life of the galvanic anode easily and inexpensively. Therefore, the cathodic protection device according to the present invention is suitably used for the cathodic protection of a small heat exchanger.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the cathodic protection device according to the present invention. FIG. 2 is a longitudinal sectional view of a mounting bolt used in the present invention. FIG. 3 is a cross-sectional view of a mounting bolt used in the present invention.

Explanation of symbols

1: cathodic protection device 2: plate-like galvanic anode 2a: first-stage plate-like galvanic anode 2b: second-stage plate-like galvanic anode 3: bolt 4: mounting bolt 4a: hole 4b: nut 4c: Bolt part 5: Nut 6: Filler 7: Anticorrosive body

Claims (5)

A plate-like galvanic anode comprising a plate-like galvanic anode having a hollow part attached to a body to be protected using bolts and nuts in the hollow part, and filling the space of the hollow part with a filler. 1st and 2nd stage plate-like current anodes or 1st to 3rd-stage plate-like current anodes, and the plate-like current-use anodes using a mounting bolt having a nut portion and a bolt portion. An electro-corrosion protection device that is fixed and attached to the body to be protected. The plate-like galvanic anode comprises a first-stage and second-stage galvanic anode, the first-stage galvanic anode is fixed with a bolt and a nut portion of a mounting bolt, and the second-stage plate-like anode The cathodic protection device according to claim 1, wherein the galvanic anode is fixed with a bolt portion and a nut of the mounting bolt. The plate-like galvanic anode comprises first to third-stage plate-like galvanic anodes, the first-stage plate-like galvanic anode is fixed with a bolt and a nut portion of a first mounting bolt, and the second-stage plate-like anode The current-carrying anode is fixed by a bolt part of a first mounting bolt and a nut part of a second mounting bolt, and the third-stage plate-like current-carrying anode is fixed by a bolt part and a nut of the second mounting bolt. 1. The anticorrosion apparatus according to 1. The cathodic protection device according to claim 1, 2 or 3, wherein the first and second plate-like galvanic anodes or the first to third plate-like galvanic anodes have the same shape. The said anti-corrosion body is a small heat exchanger, The cathodic protection apparatus in any one of Claims 1-4.

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