JP3017109B2 - External power supply type anticorrosion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external power supply type cathodic protection system for use in protection of metal structures containing low-conductivity water such as tap water and industrial water.

[0002]

2. Description of the Related Art Conventionally, in order to prevent corrosion of a metal surface such as an inner surface of a water heater tank, a drinking water tank, or an industrial water purification tank, an anticorrosion device using an external power supply system has been installed. As an electrode of the cathodic protection device, an insoluble electrode, in particular, a platinum-titanium electrode in which platinum is plated on the surface of a titanium core with several microns of platinum is generally used. Since the anticorrosion current that reaches the cathode surface such as the inner surface is rapidly attenuated as the distance from the electrode is increased, there is a problem that it is difficult to uniformly protect the cathode surface.

Therefore, as disclosed in Japanese Utility Model Application Laid-Open No. 53-95423, an insoluble linear electrode is stretched along the inner surface of the structure to be protected so that the corrosion protection current is uniformly distributed on the cathode surface. In order to prevent the linear electrode from contacting the cathode surface and short-circuiting, a method is employed in which the linear electrode is supported and fixed at an appropriate interval by an electrode support fitting appropriately provided on the inner surface of the structure to be protected.

[0004]

Conventionally, as shown in FIG. 3, an insulating member 4 such as an insulating insulator is attached to the tip of a support rod 5 for fixing to a structure to be protected by welding or the like, as shown in FIG. The attached one is used, and the linear platinum titanium electrode 1 is wound around the insulating member 4 and fixed.

However, when an electric current is passed through the platinum-titanium electrode 1, tap water or the like is electrolyzed to generate oxygen gas or chlorine gas having a strong oxidizing power, and the insulating member 4 in contact with the platinum-titanium electrode 1 is energized. In a few months later, it was deteriorated and damaged, and the platinum titanium electrode 1 was detached from the insulating member 4 to cause a short circuit accident.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art, and the insulating member of the electrode support is not deteriorated by oxygen gas or chlorine gas generated from the surface of the linear electrode. It is an object of the present invention to provide an external power supply type anticorrosion device using an insoluble linear electrode capable of maintaining stable operation for a period.

[0007]

In order to achieve the above object, the present invention provides an electrode support metal fitting on an inner surface of a structure to be protected and an inner surface of the structure to be protected so that corrosion current is uniformly distributed. An insoluble linear electrode stretched along is supported with the electrode support metal as a fulcrum, the insoluble linear electrode is on the plus side of the DC power supply, and the protected structure is on the minus side of the DC power supply. Wherein the linear electrode support of the electrode support is made of a corrosion-resistant metal, and the linear electrode support is fixed to an insulating member. It is preferable that the linear electrode support portion and the insulating member are integrally formed from the viewpoint of the fixing strength and the like.
Further, it is preferable that the corrosion-resistant metal of the linear electrode supporting portion is made of any one of titanium, niobium, tantalum or an alloy thereof.

[0008]

[Function] Titanium, tantalum, niobium or their alloys form a strong insulating passivation film in water and exhibit corrosion resistance. It does not deteriorate due to oxygen gas or chlorine gas. The breakdown voltage of titanium is 6 V, and the breakdown voltage of tantalum and niobium is 120 due to the insulating passivation film.
Since the voltage is higher than V, if the electrode voltage of the linear electrode is lower than this, the linear electrode support does not elute.

Further, the above-mentioned insulating passivation film does not cause water electrolysis on its surface even when a voltage is applied to titanium, tantalum, niobium or their alloys. The insulating member fixing the part is not deteriorated and damaged by oxygen gas or chlorine gas generated by electrolysis of water, and the linear electrode does not fall off to cause a short circuit accident.

[0010]

FIG. 1 is a partially omitted front view showing an embodiment of an electrode support fitting used in an external power supply type anticorrosion device according to the present invention. In the drawing, reference numeral 1 denotes a platinum-titanium linear electrode, and 2 denotes an electrode support. The electrode support 2 includes a linear electrode support 3 made of titanium, an insulating member 4, and a support rod 5. .

The linear electrode supporting portion 3 is composed of a rising portion from the center of the tip of the insulating member 4 and a ring-shaped tip having an overlapping portion.
Can be easily passed through the ring by pushing it into the overlapping portion.

The insulating member 4 is formed by integrally molding a glass fiber-filled polypropylene into a frustoconical shape together with the base of the linear electrode supporting portion 3 and is screwed into a supporting rod 5 from the center of the bottom toward the inside. Female thread processing is performed. The insulating member 4 is not limited to the glass fiber-containing polypropylene described above, and has electrical insulation, strength, and poor solubility.
In addition, when used for a water heater tank or the like, various known resins that can withstand repeated thermal expansion and contraction can be used. For example, inorganic resin such as a mixture of glassy powder and mica powder may be used.

The tip of the support rod 5 is externally threaded.
The other end of the support rod 5 (not shown) is fixed to the structure to be protected by welding or the like by screwing with a female screw at the center of the bottom surface of the insulating member 4.

The shape of the electrode support 2 is not limited to that shown in FIG. 1. For example, the linear electrode support 3 may have a hook shape, and the insulating member 4 may have various shapes such as a cylindrical shape. . Further, as a coupling means between the insulating member 4 and the support rod 5,
Not only the above-mentioned screwing but also various known means such as integral molding can be applied.

FIG. 2 shows an embodiment in which the present invention is applied to an actual water heater tank. Diameter 1800mm, length 2400
The electrode support fitting 2 of FIG. 2 is installed in a steel water heater tank 7 mm at both ends of the body and a total of 30 places on the end plate, and the 70 m platinum-titanium linear electrode 1 is supported by the electrode support fitting 2 as a fulcrum. 7, the end of the platinum-titanium linear electrode 1 is connected to the positive side of the DC power supply 6 and the negative side of the DC power supply 6 is connected to the hot water tank 7 to apply a DC current of about 2 A to the hot water tank 7. It flowed for months. During this time, the water temperature in the hot water tank 7 was 36 ° C to 83 ° C. After the test was completed, the hot water tank 7 was opened and an internal inspection was performed, but no deterioration or damage was found in any of the electrode support fittings 2.

[0015]

Since the present invention is configured as described above, it has the following effects. Since the linear electrode supporting portion of the electrode supporting bracket is made of a corrosion-resistant metal and the insulating member is separated from the linear electrode, the electrode insulating member is degraded by oxygen gas or chlorine gas generated from the surface of the linear electrode. The linear electrode does not fall off from the electrode support, and the stable operation of the external power supply type anticorrosion device can be maintained for a long time.

[Brief description of the drawings]

FIG. 1 is a partially omitted front view showing an embodiment of an electrode supporting bracket used in an external power supply type anticorrosion device according to the present invention.

FIG. 2 is a schematic view showing the mounting of the external power supply type anticorrosion device of the present invention.

FIG. 3 is a partially omitted front view of a conventional electrode support.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Platinum-titanium linear electrode 2 Electrode support bracket 3 Linear electrode support part 4 Insulating resin 5 Support rod 6 DC power supply 7 Water heater tank

Claims (3)

(57) [Claims] 1. An insoluble linear electrode stretched along an inner surface of a structure to be protected so as to distribute an anti-corrosion current uniformly by disposing an electrode support bracket on an inner surface of the structure to be protected. An electro-corrosion protection device configured to support a support metal as a fulcrum, connecting the insoluble linear electrode to the positive side of the DC power supply, and connecting the protected structure to the negative side of the DC power supply, An external power source type cathodic protection device, wherein the linear electrode support of the electrode support is made of a corrosion-resistant metal, and the linear electrode support is fixed to an insulating member. 2. The external power-supply type cathodic protection device according to claim 1, wherein said linear electrode support portion and said insulating member are integrally formed. 3. The external power supply type cathodic protection device according to claim 1, wherein said corrosion-resistant metal is made of any one of titanium, niobium, tantalum and an alloy thereof.