JPS6335716B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a corrosion-protective electrode device used for electrolytic protection of the inner and outer surfaces of a metal container filled with water or seawater and suspended in the water or seawater, a so-called external power supply system. be.

In heat exchange equipment for ships, nuclear power plants, thermal power plants, etc. built near the coast, both the inner and outer surfaces of the containers are often in constant contact with seawater. For example, in the case of a ship such as a tanker, in order to increase the weight of the hull without cargo, it is necessary to draw seawater into the balance tank and fill it while sailing, and the hull shell is constantly immersed in seawater while sailing. There is. Alternatively, in a power plant, in order to cool a heat exchange device, a seawater intake port is provided and the seawater sucked up through a pipe is allowed to flow onto the surface of the heat exchanger.

Tanks that are filled with seawater to ensure the stability of a ship's navigation, or heat exchange equipment at power plants, are constantly in contact with seawater, so the steel materials that make up them are subject to corrosion. Therefore, it is necessary to take so-called anti-corrosion measures, and in particular, in the case of the above-mentioned example, it is necessary to take measures on the inner and outer surfaces.

In these corrosion protection methods, when applying an external power supply type cathodic protection method, the immediate problem is the corrosion protection electrode that becomes the anode electrode. By the way, the essential characteristic conditions that this anti-corrosion electrode must have are as follows.

First, as a general characteristic, it has to maintain a high degree of watertightness and insulation properties. It is controlled by the insulator that also serves as an adhesive, and its watertight properties are determined by the coefficient of thermal expansion, adhesive properties, structure, etc. of the anode, cathode, and insulator materials. The insulator material and anode part have high wear resistance, and they have high thermal and mechanical impact strength and long-term reliability. In order for it to be useful as a practical product, it must be able to maintain the appropriate current value required for corrosion protection (hereinafter referred to as anti-corrosion current), be easy to attach to the container wall, and be able to be installed on the inner or outer wall of the container. These features include that it can be attached freely from the ground, and that it is easy to connect to a current-carrying conductor and to hold the conductor wire easily.

First, it is necessary to ensure an appropriate anticorrosion current. For example, in the case of the heat exchanger described above, the temperature of seawater constantly fluctuates. In this case, the electrical conductivity of seawater also inevitably changes, and the current value naturally increases or decreases. If the current value is less than the anti-corrosion current, no anti-corrosion effect can be obtained, and if it is too much, excessive corrosion protection will occur and damage the container.
Next, regarding the ease of installation and the relationship between the mounting surfaces on the inner and outer walls of the container, in the case of large containers such as ship hulls, it is easy to install from the inner wall, but mounting from the outer wall requires extremely complicated work. This is an important condition. Next is the connection between the anode part and the conductor. If the insulation of the connection part is not completely ensured, chlorine gas will be generated in this part in the case of seawater, corroding the conductor and shortening its useful life. lead to defects. Also, the conductor must be held securely. This is especially important in cases where seawater flows quickly, such as in the hull of a ship.

Focusing on these points, what was considered by the inventor will be explained with reference to FIG. In the figure, a is a reference electrode, and this reference electrode a is an anode rod 1 made of metal titanium plated with platinum inside the through hole 2-2 of the outer peripheral fitting 2 made of iron material and having a through hole 2-2 in the center. The reference electrode rod 9 made of copper, copper alloy, silver, silver lead alloy, iron or stainless steel is made from a mixed powder of vitreous powder and mica powder, heated to a temperature at which the vitreous material softens and flows under pressure. , mica pressure molded under heating conditions;
The insulator 3 is made of glass plastic, and both ends of the insulator 3 are protruded and fixed in a watertight manner. The reference electrode rod 9 has one end protruding from the end surface of the insulator 3 on the side that is immersed in the seawater 5, and the anode rod 1 is surrounded by a semi-cylindrical protrusion 3-1 connected to the end surface. One end protrudes from the end surface. The length and diameter of this protruding portion of the anode rod 1 are determined according to the anticorrosive current capacity, but there are no restrictions on the shape of the reference electrode rod 9, and any method that is easy to manufacture may be used. The anode rod 1 of this reference electrode a has a protrusion 3
-1, creeping insulation resistance with the cathode part is ensured.

The anode rod 1 and the reference electrode rod 9 are connected to the current carrying conductor by using an insulated conductor 12 as the current conducting wire, and connecting the anode rod 1 and the reference electrode 9 with a connecting fitting 13 except for the insulated part at the tip. The joint fitting 13 and the tip of the insulating coating of the insulated conductor 12 are in contact with the surface of the insulator 3 and are insulatingly coated with an insulating part 14 made of a solvent-free organic resin. In this way, the insulation of the joint is completely ensured, so there is no corrosion, and it can be used easily and reliably even under conditions where seawater is present inside and outside the container. The outer peripheral fitting 2 is attached to the container wall 4 by a mounting screw 2-1 provided on its outer periphery, and the anode rod 1, reference electrode rod 9, and container wall 4 are connected to the constant potential electrolyzer 10 by a conductive wire 7. It is connected at section 8. When a set voltage Us is set in the constant potential electrolyzer 10 from an external power supply, the amplifier A changes the electrolysis current IC to control the control voltage U _R to be equal to the set voltage Us. If the reference electrode rod 9 is made of the same material as the container wall 4, by setting Us to 1 to 2 V, the potential of the container wall 4 and the outer metal fitting 2 will be 1 to 1 lower than the natural corrosion potential.
It is kept at a 2V lower potential, which prevents excessive corrosion protection at even lower potentials. By adjusting the set voltage according to the potential of the reference electrode rod 9, a corrosion protection current flows to maintain the proper potential. It is possible to devise the position where the reference electrode is attached so that each part is below the anti-corrosion potential, and it is also possible to attach a plurality of reference electrodes, so that an appropriate anti-corrosion current can always flow through each part.

When using the above-mentioned reference electrode a and constant potential electrolyzer to protect the inside of a simple seawater storage container, for example, the outer surface of the container is in the air, so the reference electrode a and the constant potential electrolyzer are used for comparison against the container wall as shown in Figure 1. Attach electrode a,
Although it is possible to obtain a complete corrosion protection effect using a constant potential electrolyzer, it is recommended to simultaneously protect the inner wall of a balance tank filled with seawater, such as a tanker, and the hull shell, which is constantly immersed in seawater. In this case, unavoidable and fatal problems arise in the method of attaching the reference electrode a, the holding of the conducting wire, etc. This will be explained in detail with reference to FIG.

In Fig. 2, 4 is a container made of steel;
5 is seawater filled inside the container 4, 6 is the container 4
The seawater a, a'' existing outside the chamber is attached to the container wall 4 by the conventional reference electrode a shown in FIG. -1, 9-1 are located in the seawater 5 inside the container, the current-carrying parts 1-1, 9-1 of the reference electrode a are located in the seawater 6 outside the container, and the insulated conductor 12- of the current-carrying conductor is located in the seawater 5 inside the container. 1 and 12-2, the reference electrode a' is located in the seawater 6 outside the container, and the reference electrode a is located in the seawater 5 inside the container.The anode rod 1 and the reference electrode rod 9 are connected to the insulated conductor 1.
2-1 and 12-2 are connected to the constant potential electrolyzer 10 to maintain and ensure an appropriate anti-corrosion current, so a complete anti-corrosion effect can be obtained and there is no problem in this respect, but in practical terms the following There is a problem. In other words, since the reference electrode a has the insulated conductors 12-1 and 12-2 attached from the inside of the container 4, there is no major problem with inspection, maintenance, or replacement of the reference electrode, and the insulation Although it is easy to fix the covered conductors 12-1 and 12-2, the reference electrode a' is attached from the outside of the container 4, and the insulated conductors 12-1 and 12-2 are also located outside. There is. This means that when attempting to protect the inner wall of the balance tank by attaching it to the outer panel of the hull as described above, it is difficult to attach the reference electrode itself, and the insulated conductors 12-1 and 12-2 are located outside the hull. Since it is exposed to constantly flowing seawater, there are problems such as requiring a lot of work to fix it, but the biggest problem is that when installing it to the container wall 4, a through hole is always required in the container wall. That is to say. In the case of vessels with thick walls, such as the outer panels of ships, this becomes a fatal defect and is an unavoidable reason why it is not widely used despite its excellent properties.

The present invention provides a highly practical anti-corrosion electrode device that eliminates the above-mentioned drawbacks.

An embodiment of the present invention shown in FIG. 3 will be described below. FIG. 3A is a bottom view, and FIG. 3B is a developed longitudinal sectional view taken along line A-A' in FIG. 3A. Reference numeral 1 denotes an anode rod, which is made of platinum-cast titanium metal and has a structure in which it branches into a Y-shape at a branch point 1-2, and has parallel long legs 1-3 and short legs 1-4. are doing. Reference numeral 9 denotes a reference electrode rod, which is made of stainless steel. Copper and copper alloys, silver,
It uses the same materials as conventional products, such as silver-lead alloy and iron. Like the anode rod 1, it has a structure in which it branches into a Y-shape at a branch point 9-2 and has parallel long legs 9-3 and short legs 9-4. Reference numeral 2 denotes a mounting bracket, which is made of iron and is the same as that shown in FIG. 1. Reference numeral 3 represents a first insulating material, which is made of glass or mica, similar to that shown in FIG.

Each branch point 1-2, 9 of the anode rod 1 and reference electrode rod 9
-2 is located on the center line within the through hole 2-2 of the mounting bracket 2, and the short leg portion 1-4 of the anode rod 1 and the reference electrode rod 9
The long leg part 9-3 of the anode bar 1 and the short leg part 9-4 of the reference electrode bar 9 face each other, and both are kept parallel to each other. -4,9-
3 and 9-4 are arranged to be located at the center of the 1/4 cylindrical body of the through hole 2-2 of the mounting bracket 2, and the space is filled with the first insulator 3 and hermetically sealed. The long leg 1 of the anode rod 1 is insulated with the
-3 side, a third insulator 3-1 connected to the first insulator 3 and protruding into a 1/4 cylinder shape is provided and surrounds the long leg portion 1-3. The current-carrying portion 1-1 of -3 extends beyond that. The short leg portion 1-4 of the anode rod 1 and the long leg portion 9-3 of the reference electrode rod 9 are a second insulator 3-2 that protrudes into a semi-cylindrical shape and has a shorter length than the third insulator 3-1. It is surrounded by one piece, and its tip is exposed. In addition, the short leg portion 9- of the reference electrode rod 9
The current-carrying portion 9-1 of No. 4 is also exposed.

In addition, the tightening part 2-3 of the mounting bracket 2 is the current-carrying part 1-
1, located on the 9-1 side and the mounting screw 2-1 on the opposite side
is screwed on. The first insulator 3 on the screw side, including the anode rod 1 and the reference electrode 9, is partially removed and the part is filled with a solvent-free organic resin to form the anode rod 1 and the reference electrode 9. An insulating section 15 is configured. Short leg part 1-4 of anode rod 1 and reference electrode rod 9
The exposed part of the long leg part 9-3 has an insulated conductor 12-
1 and 12-2 except for the insulating coating portions, the conductive wire portions are crimped and bonded using a joining fitting 13, and a semi-cylindrical insulating portion 14 is made of solvent-free organic resin including the insulating coating portions.
is configured.

The above reference electrode b maintains the same general characteristics as the conventional reference electrode a.

First, an embodiment of the state in which the inside and outside of a container are protected from corrosion using the reference electrode b according to the present invention will be described with reference to FIG. In Figure 4, 4, 5, 6, 7, 8, 1
0, 12-1, 12-2 and reference electrode a are the second
Same as the figure. Reference electrode b is a reference electrode according to the present invention shown in FIG. 3, and is shown in a developed cross-sectional view, but its actual size is the same as reference electrode a. It is attached from the inside of the container 4, and the insulated conductor 1
2-1 and 12-2 are located in the container 4, and are attached under exactly the same conditions as the reference electrode a.
1 and 12-2 are also processed under the same conditions. In actual use, they can be used side by side.

Next, an example of corrosion protection under conditions where it is extremely difficult to provide a through hole for attachment in a thick vessel wall such as the outer panel of a ship will be described with reference to FIG. In Figure 5, 4, 5, 6, 7, 8, 10
is the same as in Figure 4. 16 is a mounting plate joined to the container wall 4. The reference electrode b according to the present invention is attached to a mounting plate 16. In this case, since watertightness is not required for attaching the reference electrode b to the mounting plate 16, the labor involved in attaching it is greatly reduced.

Although the above description has been made of the case where the entire anode rod of the reference electrode is made of titanium plated with platinum, platinum plating may be applied only to the current-carrying part that is immersed in seawater, or if the corrosive liquid is only seawater as described above. The present invention is also applicable to conductive corrosive liquids.

As described above, according to the anticorrosion electrode device of the present invention, it can be installed without providing a through hole in the wall of the container, so it can be easily installed even on containers with thick walls, and the installation cost is reduced. be.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structure of a conventional reference electrode and how it is used. FIG. 1A shows a longitudinal sectional view and connections of the electrode, and FIG. FIG. 2 is a diagram showing a state in which a conventional reference electrode is used to protect the inner and outer surfaces of a container from corrosion, and FIG. 3 is a diagram showing an embodiment of the reference electrode according to the present invention.
Figure A is a bottom view, and Figure 3B is a developed vertical sectional view.
FIG. 4 is a diagram showing an embodiment in which a reference electrode according to the present invention and a conventional reference electrode are used together to protect the inner and outer surfaces of a container from corrosion. FIG. 5 is a sectional view showing an embodiment in which the container wall is attached without providing a through hole. In the figure, 1 is the anode rod, 1-1 is the current-carrying part, 1-4 is the short leg part, 2 is the mounting bracket, 3 is the first insulator, 3-
1 is the third insulator, 3-2 is the second insulator, 4 is the container or the container wall, 5 is the seawater inside the container, 6 is the seawater outside the container, 7 is the conducting wire, 8 is the connection part, 9 is a reference electrode rod, 9-1 is a current-carrying part, 9-3 is a long leg part, 1
0 is a constant potential electrolyzer, 12-1 and 12-2 are insulated conductive wires, 13 is a joining fitting, 14 and 15 are insulating parts, and 16 is a mounting plate. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. In a corrosion-preventing electrode device having both a reference electrode rod for sensing an anti-corrosion current and an anode rod for anti-corrosion, the following
A corrosion-protective electrode device characterized by comprising (a) to (g). (a) A reference electrode rod that is branched into a Y-shape and has a short leg portion and a long leg portion that are parallel to each other. (b) An anode electrode rod which is branched into a Y-shape and is formed with a short leg part having approximately the same length as the long leg part of the reference electrode and a long leg part having a predetermined length, which are parallel to each other. (c) A cylindrical mounting bracket in which the reference electrode and the anode rod are arranged approximately in the center so that the long leg of the reference electrode and the short leg of the anode bar face each other while maintaining parallelism. (d) A first component sealed in the mounting bracket and formed so that the end of the short leg of the reference electrode is exposed and the long leg of the reference electrode and the long leg and short leg of the anode electrode are protruded. Insulator. (E) A second insulator that surrounds the long leg of the reference electrode and the short leg of the anode rod, and is formed so as to protrude from the first insulator so that its tip is exposed. (F) A third insulator connected to the first insulator, protruding longer than the second insulator, surrounding the long leg of the anode rod, and exposing its tip. (g) An insulated conductor wire that is connected to the ends of the long leg of the reference electrode and the short leg of the anode rod with the joints sealed and insulated. 2. The reference electrode rod is made of one of iron, silver, silver-lead alloy, stainless steel, copper, and copper alloy, and the anode rod is made of titanium plated with platinum.
and the third insulator is glass or mica plastic made of vitreous powder and mica powder, and the insulating seal of the connection part is made of an organic resin material. The anti-corrosion electrode device described.