JPH02270221A - Surface treatment of aluminum aerial power transmission line - Google Patents

Abstract

PURPOSE:To color an aluminum aerial power transmission line with color tone matching its surroundings by a method wherein the surface is roughed by applying sand blaster treatment, specific aqueous solution is applied on the roughed surface and dried to have corrosion with coating caused, and then colored. CONSTITUTION:With an aluminum overhead transmission line 1 running with specific speed, it is passed through a sand blaster 2 first wherein MORUNDUM #80 for example is projected toward the surface of the transmission line 1 form three nozzles 5 placed in a circle at constant intervals to have its surface roughed. Then the roughed transmission line 1 is passed through a high frequency induction heating furnace 3 to be heated and then coloring solution 7 is sprayed with a coloring solution spray 4 to color the surface of the transmission line 1. Aqueous solution of ferric chloride is used as the coloring solution 7, and corrosion of aluminum by chlorine ions, reaction of iron ions to ferric chloride and evaporation and drying of moisture can be completed almost simultaneously in several seconds so that a light brown coat is formed. Thus reflection of the sunlight is reduced while the surface color tone can be matched to its surroundings.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for surface treatment of aluminum overhead power transmission lines, and more specifically, it can significantly reduce the reflection of sunlight and further improve the color tone of the surface of the overhead power transmission lines. This invention relates to a surface treatment method for aluminum overhead power transmission lines that can be made to have a color tone that is in harmony with the environment.

[Conventional technology]

Aluminum overhead power transmission lines are usually constructed by twisting and covering the outer periphery of a steel wire core material, which is a wire reinforcing material, with a large number of aluminum wires, and are connected to power transmission lines as they are.

[Problems to be Solved by the Invention] By the way, this aluminum overhead power transmission line has a high reflectance of sunlight on its surface and is white in color. Therefore, if an aluminum overhead power transmission line is connected to a power transmission line in a national park or close to a beautiful building, it will look out of place with the surrounding landscape.

For this reason, in recent years, the Environment Agency and environmental protection organizations have pointed out that aluminum overhead power transmission lines damage the environmental landscape, and there have been strong calls for a solution to this problem.

In response to the above requirements, methods of coloring aluminum overhead power transmission lines in a color tone that matches the landscape have been studied, and power transmission lines that have been colored by electrolytic treatment or coated with colored plastics have come to be used.

However, since all of these methods form an electrically insulating film on the surface of the aluminum material, in addition to the disadvantage of increasing electrical resistance at the wire connection part, there are limitations on hue and chromaticity, and there are various problems. It was difficult to match it with the landscape.

[Means to solve the problem]

The present invention was developed in view of this situation, and its purpose is to provide a surface treatment for aluminum overhead power transmission lines that has a low reflectance of sunlight, has a color tone that matches the surrounding landscape, and has excellent connectivity. The purpose is to provide a method.

That is, the present invention roughens the surface by performing sandblasting on the surface of the aluminum overhead power transmission line after the completion of the twisting process, and then applies ferric chloride as a basic component to the roughened surface obtained. It is characterized by applying an aqueous solution of the same and drying it to cause film-forming corrosion and coloration.

The method of the present invention is a treatment method applied to the surface of an aluminum overhead power transmission line formed by twisting a large number of aluminum wires around the outer periphery of a steel wire core.

The surface treatment method according to the present invention includes two steps: roughening the surface of an aluminum overhead power transmission line, and subsequently coloring the roughened surface.

The first surface roughening treatment is performed to reduce the sunlight reflectance of the aluminum overhead power transmission line and to effectively proceed with the coloring treatment in the next step.

The surface roughening treatment is performed by sand plastering. As the blasting material used for sandblasting, it is preferable to use a grid of a predetermined particle size that has enough hardness not to be crushed by the blasting energy at that time and has acute corners. As such a grid, for example, Morundum (trade name, manufactured by Showa Denko K.K.), which is made of silicon carbide thread and has a particle size of 40 to 120 mesh, can be used.

When projecting the projection material, it is preferable to use an air pressure of 3 to 7 kg/cd.

Thus, the surface of the aluminum overhead power transmission line is ground into a roughened state by the blasting material. The roughened surface formed at this time is generally designed to reduce the reflectance of sunlight.
It is preferable that the roughness is approximately 150 to 150.

The coloring treatment in the present invention, in which the roughened surface thus formed is subjected to coloring treatment, is performed by the following method.

That is, a roughened aluminum overhead power transmission line is heated to a predetermined temperature using, for example, a high-frequency induction heating furnace, and then an aqueous solution containing ferric chloride as a basic component is sprayed onto the surface of the heated power transmission line. The surface of the electric wire is corroded by the chlorine ions in the aqueous solution, which further oxidizes the iron ions and rapidly removes moisture.

Coloring is caused by rapid evaporation and formation of an iron oxide film on the surface of the power transmission line, causing so-called film-forming corrosion. This colored film has the characteristic that it does not discolor even after repeated washing and drying.

In the method of the present invention, the aqueous solution containing ferric chloride as a basic component includes, for example, a ferric chloride aqueous solution, a mixed solution of ferric chloride and tannin, or a mixed solution of ferric chloride, tannin, and potassium ferrocyanide. Applicable.

In the method of the present invention, when a ferric chloride aqueous solution is used as the aqueous solution (hereinafter referred to as a colored solution) to be sprayed onto an aluminum overhead power transmission line, the color tone of the film is gray to brown, and the color tone varies with ferric chloride. It is approximately proportional to the concentration of

The use of a colored liquid obtained by adding tannin to the aqueous solution has the effect of darkening the color tone and increasing the astringency, and the colored liquid adheres with good wettability even when the surface to be sprayed is covered with an oil film and exhibits hydrophobicity.

In addition, when using a coloring solution in which potassium ferrocyanide is added to a mixed solution in which ferric chloride and tannin coexist, the film develops a blue to green color even with the addition of a small amount, and the color tone can be controlled to various intermediate colors depending on the amount added. be able to.

Next, conditions for applying the coloring component will be described.

The aqueous solution concentration of ferric chloride, which is the basic component of coloring, is 0.
If it is less than 5% by weight OA (hereinafter abbreviated as %), sufficient coloring will not be obtained, and if it exceeds 4%, the coloring will be excessive, giving a sense of incongruity with the environmental color.
3% is preferred.

It is preferable to prepare, for example, a 2% aqueous solution of the tannin to be added to the ferric chloride aqueous solution, and to mix this aqueous solution with the ferric chloride so that each coloring component is mixed homogeneously.

In the above, if the mixing amount of the 2% tannin aqueous solution is less than 5% by volume, the effect on tannin color tone or water wettability will be poor, and if it exceeds 50% by volume, the effect will be saturated, so mix 5 to 50 volumes. %, particularly 20 to 40% by volume.

In addition, when potassium ferrocyanide is further added to the mixed aqueous solution of ferric chloride and tannin, a 0.5% aqueous solution of potassium ferrocyanide is prepared in advance, and this aqueous solution is mixed with the mixed aqueous solution of ferric chloride and tannin. This is preferable because the coloring components are mixed homogeneously.If the amount of the 0.5% aqueous solution of potassium ferrocyanide is less than 1% by volume, the blue to green color will be poor, and if it exceeds 10% by volume, the blue to green color will be too much, which may actually affect the visual sense. 1 to 10% by volume, particularly preferably 2 to 6% by volume.

In the method of the present invention, the method of applying the colored liquid to the surface of the aluminum overhead power transmission line is preferably a method of spraying with an atomizing nozzle or the like, since the coating can be uniformly applied.

In the above, it is preferable that the amount of the coloring liquid applied is set to such an extent that the surface of the overhead wire is not entirely wetted, so that even coloring can be achieved. In addition to the spraying method, methods of applying the colored liquid by impregnating foamed urethane or the like with the colored liquid are commonly used.

In the method of the present invention, drying of the colored liquid applied to the surface of an aluminum overhead power transmission line is achieved by heating the overhead line to a predetermined temperature in advance before spraying the colored liquid. This is preferable because production type corrosion is uniform.

Further, the heating temperature is preferably 90±30°C, and any heating method such as a high frequency induction heating method or a flame heating method can be applied.

[Function] In the method of the present invention, the surface of the aluminum overhead power transmission line, which has been made low in reflectance by shot blasting, is colored by causing film-forming corrosion with a ferric chloride aqueous solution, so that the surface of the power transmission line has a low reflectance. By adding a small amount of tannin to the water distribution solution, the color tone becomes darker and the astringency increases, and by adding potassium ferrocyanide in an amount, the color tone becomes blue. ~ greenish, so aluminum overhead power lines can be colored to a shade of ballast reflectance that can match any landscape.

In addition, the aluminum overhead power transmission line obtained by the method of the present invention is perceived as a colored wire because the iron oxide dots distributed on the surface of the aluminum overhead power transmission line appear continuous when viewed from a distance. The aluminum base is exposed on the surface of the power transmission line except for the area where iron oxide is distributed.
Therefore, there is an advantage that the electrical resistance does not increase at the electrical connection portion, and furthermore, the point-like distribution of iron oxide reduces the surface tension of water, thereby improving water wettability.

〔Example〕

In Figure 0, which is an explanatory view of the main parts of an example of a coloring device for Miniram overhead power transmission lines, 1 is an aluminum overhead power transmission line in which a large number of aluminum wires are twisted together on a steel wire core, and 2 is the aluminum overhead power transmission line. 3.4 is a high-frequency induction heating furnace and a coloring liquid spraying machine for preheating and coloring the roughened aluminum overhead power transmission line, respectively.

The aluminum overhead power transmission line 1 is run at a speed of 2 m/sin, and first passed through the sand plaster 2, and a circle is placed at equal intervals 10 cm away from the running aluminum overhead power transmission line 2 inside the sand plaster 2. 3 placed open
Morundum #80 (manufactured by Showa Denko K.K., silicon carbide projection material) was projected onto the surface of the power transmission line 1 by applying an air pressure of 5 kg/ej from the nozzle 5 of 5 to roughen the surface. The flattened power transmission line l is passed through a high frequency induction heating furnace 3 with a furnace length of 0.8 m, heated to 90°C, and then heated to a colored liquid sprayer 4.
Then, the colored liquid 7 drawn up by the siphon from the colored liquid storage tank 6 to the colored liquid spraying machine 4 is applied to the roughened surface of the power transmission line 1 heated to 90"C through two air atomizing nozzles facing each other. 8 to color the surface of the power transmission line 1.

In the above, a 3% aqueous solution of ferric chloride was used as the coloring liquid 7, and the spray amount was adjusted to such an extent that the entire surface of the method 1twA1 was not completely wetted. As a result, in the colored liquid 7 sprayed onto the surface of the power transmission line 1, the corrosion of aluminum by the chlorine ions in the colored liquid 7, the reaction of iron ions to iron oxide, and the evaporation and drying of moisture are completed almost simultaneously within a few seconds. As a result, a light brown film was formed on the surface of the power transmission line 1.

The power transmission line 1 colored in this manner was wound onto a drum 10 via a caterpillar 9.

The aluminum overhead power transmission line thus obtained was left outdoors for 10 days, 70 days, and 180 days, and its color tone, degree of fading, and water wettability were investigated. The results are shown in Table 1. It was shown to.

Table 1 As is clear from Table 1, even after 180 sips, the color remains the same slightly pale brown color as immediately after production, with no fading observed at all, and the water wettability of the surface remains unchanged after 70 days. The oil content was washed out, indicating good wettability.

Example 2 In Example 1, the running speed of the aluminum overhead power transmission line was 3 m/in, Morundum #100 was used as the sand plaster blasting material, and the blasting air pressure of the blasting material was 6 k.
g/cd, the heating temperature of the power transmission line by the high frequency induction heating furnace was 110'C, and the coloring liquid contained 2% ferric chloride.
70% by volume of an aqueous solution and 30% by volume of a 2% tannin aqueous solution
An aluminum overhead power transmission line was surface-treated in the same manner as in Example 1, except that a mixed solution of the above was used. The same investigation as in Example 1 was conducted on the aluminum overhead power transmission line thus obtained. The results are shown in Table 2.

As is clear from Table 2, the color tone was dark brown with an astringent taste, and the water wettability was also good from the beginning.

This is due to the effect of tannins added to the coloring liquid. Further, no fading was observed at all.

Example 3 In Example 1, the sand plaster projection air pressure was set to 4 k.
g/d, and the heating temperature of the aluminum overhead power transmission line by the high-frequency induction heating furnace was 100"C.
The surface of an aluminum overhead power transmission line was treated in the same manner as in Example 1, except that a mixed solution of 60% by volume of a 4% iron aqueous solution, 35% by volume of a 2% tannin aqueous solution, and 5% by volume of a 0.5% potassium ferrocyanide aqueous solution was used. Ta. The same investigation as in Example 1 was conducted on the aluminum overhead power transmission line thus obtained. The results are shown in Table 3.

As is clear from Table 3, the color tone became greenish, which was due to the action of potassium ferrocyanide. ? ! The color slightly decreased in green color up to 70 days, but no change was observed thereafter, and the water wettability was also extremely good due to the action of tannin.

Example 4 Example 3 except that in Example 3, a mixed solution of 60% by volume of a 2% ferric chloride aqueous solution, 30% by volume of a 2% tannin aqueous solution, and 10% by volume of a 0.5% potassium ferrocyanide aqueous solution was used as the coloring liquid. Surface treatment of aluminum overhead power transmission lines was carried out using the same method as described above. The same test as in Example 1 was conducted on the aluminum overhead power transmission line thus obtained. The results are shown in Table 4.

Table 4 As is clear from Table 4, the color tone became a bluish grayish brown due to the increased amount of potassium ferrocyanide and decreased amount of tannin. The color fading was such that the blue color slightly decreased up to 70 days, and no change was observed thereafter, and the water wettability was also extremely good.

[Effect] As is clear from the above explanation, according to the method of the present invention,
The surface of aluminum overhead power transmission lines can be roughened to reduce the reflectance of sunlight, and the surface color can be made to harmonize with the surrounding environment, so it does not harm the landscape and aesthetics of the environment. This problem can be solved. Furthermore, water wettability is improved, making it possible to prevent corona discharge and AN (audible noise) generation during HV to UHV power transmission, which has great industrial value.

[Brief explanation of drawings]

FIG. 1 is an explanatory view of essential parts showing an example of an apparatus for coloring aluminum overhead power transmission lines that implements the method of the present invention. 1... Aluminum (Al) overhead power transmission line, 2...
Sand plaster, 3... High frequency induction heating furnace, 4.
... Colored liquid spray machine, 7... Colored liquid. Patent Applicant Furukawa Electric Co., Ltd. IAj Overhead Power Transmission Line Figure 1 Procedural Amendment (Voluntary) 3. Relationship with the person making the amendment Patent Applicant Address 2-6-1 Marunouchi, Chiyoda-ku, Tokyo 100
Item 4: Subject of amendment “Detailed description of the invention” in the specification
column. 5. Contents of the amendment (1) In the 17th line of page 2 of the specification, the phrase "colored by electrolytic treatment" is amended to read "colored by chemical conversion treatment." (2) On page 6, lines 5 and 6 of the specification, the phrase ``The color tone becomes darker when using a colored liquid'' is corrected to ``The color tone becomes darker when a colored liquid is used.''

Claims (1)

[Claims] After the twisting process is completed, the surface of the aluminum overhead power transmission line is subjected to sandblasting to roughen the surface, and then an aqueous solution containing ferric chloride as a basic component is applied to the obtained roughened surface. A method for surface treatment of aluminum overhead power transmission lines, characterized by coloring the aluminum overhead power transmission lines by drying and causing film-forming corrosion.