JPS5838889B2 - Surface treatment method for overhead power transmission lines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface treatment method for an overhead power transmission line in which only the outer surface of an overhead power transmission line having aluminum wires twisted in the outermost layer is chemically treated to reduce the generation of corona.

Conventionally, aluminum stranded wires with aluminum strands twisted together in the outermost layer and steel-core aluminum stranded wires have generally been used as overhead power transmission lines.

In such overhead power transmission lines, especially when it rains, water droplets adhere to the surface of the stranded wires and generate corona.

The reason why corona is likely to occur due to adhesion of water droplets is that the adhering water droplets are spherical and adhere to the surface.If the water droplets adhering to the surface do not become spherical and wet the entire surface, corona will not occur. It becomes less.

This shows that by increasing the hydrophilicity of the surface of the stranded wire, the water droplets do not become spherical, thereby reducing the occurrence of corona.

It is also known that corona is less likely to occur in overhead power transmission lines that have been installed for many years than in newly installed overhead power lines because the water droplets attached to the surface do not form into spherical shapes.

Conventionally, as a means of increasing the hydrophilicity of the surface of overhead power transmission lines, the strands that are to be twisted into the outermost layer as overhead power transmission lines are individually treated to make them hydrophilic before being twisted. The manufacturing efficiency is not very good.

That is, conventionally, a film of a hydroxyl-containing compound was formed around the outer periphery of the wire, and this was twisted into the outermost layer (Japanese Patent Publication No. 36-14).
(see Japanese Patent Publication No. 36-14185), sandblasting the surface of the wire to form fine irregularities on the outer periphery of the wire, and then twisting this into the outermost layer. There is also a method previously proposed by the present applicant in which the oil on the surface of each strand is removed and twisted to produce a stranded wire with less corona generation (Japanese Patent Application No. 49674/1983). However, in all of these methods, the wires to be twisted into the outermost layer are subjected to a hydrophilic treatment before being twisted, resulting in a poor production efficiency of the twisted wires.

In view of this, the present invention consists of twisting aluminum wires in the outermost layer, making them into twisted wires, and then chemically treating the outer surface of the aluminum wires in the outermost layer to increase the hydrophilicity of the aluminum wires and corona corona. This reduced the occurrence of

That is, the outermost surface of the aluminum wires twisted in the outermost layer is sprayed with an alkaline or acidic solution such as caustic powder or hydrochloric acid, which easily corrodes aluminum, so that the outermost surface becomes wet in the form of stripes. The outer surface of the aluminum wire, that is, the outermost surface of the overhead power transmission line, was corroded in a striped manner to make it more hydrophilic.

In this way, by spraying the solution in the form of a mist onto the outermost surface of the overhead power transmission line, a large area can be treated with a small amount of solution. The depressions are small, so that the decrease in mechanical strength of the outermost layer aluminum wire can be minimized.

Furthermore, since the solution is sprayed onto the outermost surface of the overhead power transmission line so that it is wet, the solution will not get around to the inner surface of the outermost aluminum wire and will not corrode it. Not only does it not cause corrosion, it does not corrode the inner layer of galvanized steel wire, etc., and does not reduce their mechanical strength.

Moreover, the outermost surface of the overhead power transmission line can be reliably treated to make it hydrophilic, and stranded wires with less corona generation can be easily produced.

Next, examples of the present invention will be shown.

AC8R810mm2 (AI 4.8/45, St3.
2/7) at approximately 40°C, and sprayed with a sprayer at 5°C.
% NaOH (7) aqueous solution and HCl were sprayed onto the stranded wire surface.

In this case, the aqueous solution is applied to the outermost surface of the overhead power line.
Spray it in a mist so that it gets wet.

Thereafter, this was left for about two weeks to produce a hydrophilized overhead power transmission line.

After pouring water into such electric wires in the shower for 1 hour, we observed the adhesion of water droplets on the surface of the molded wires, and found that the wires treated with 5 tons of Na 0 H (7) aqueous solution had good hydrophilicity and no spherical water droplets were formed. The water droplets disappeared 4 minutes after water injection was stopped.

Some spherical water droplets were formed in the case treated with HCI, but these disappeared 10 minutes after water injection was stopped.

On the other hand, in the case of the untreated wire, spherical water droplets were formed on the surface of the stranded wire, and it took 50 minutes for them to disappear.

In the above embodiment, caustic soda and hydrochloric acid were used as the chemical treatment liquid for the aluminum wire, but the present invention is not limited thereto, and for example, KOH, HF, etc. may also be used.

As explained above, according to the present invention, an alkaline or acidic solution such as caustic soda or hydrochloric acid, which easily corrodes aluminum, is applied to the outer surface of an overhead power transmission line whose outermost layer is made of twisted aluminum wires. The outermost surface of the overhead power transmission line is chemically treated in the form of stripes to make it more hydrophilic, so water droplets do not adhere to such overhead power transmission lines. In this case, the stranded wire does not form a spherical shape, but spreads out to wet the surface of the stranded wire, thus reducing the occurrence of corona.Moreover, the hydrophilic treatment is performed after the stranded wire is stranded, and then the treatment solution is applied so that the outermost surface of the overhead power transmission line is wetted in a single shape. Since the treatment is carried out by spraying it in the form of a mist, not only can the decrease in mechanical strength of the overhead power transmission line be minimized, but the treatment is also simple and does not require the conventional method of treating each strand one by one before twisting. This method has the advantage of being able to manufacture stranded wires more efficiently than other methods.

Claims (1)

[Claims] 1. Apply an alkaline or acidic solution such as caustic soda or hydrochloric acid to the outer surface of an overhead power transmission line whose outermost layer is made of aluminum wire such as aluminum stranded wire or steel-core aluminum stranded wire. 1. A method for surface treatment of overhead power transmission lines, which comprises spraying the spray in the form of a mist so that the outer surface is wetted, and drying to chemically treat the outermost surface of the overhead power transmission line in a uniform manner.