RU115697U1 - ELECTRODE FOR ELECTRIC SPARK DOPING OF ELECTRIC TRANSMISSION WIRES - Google Patents

Abstract

Electrode for electrospark alloying of aluminum wires of overhead power lines, made of shungite from the Zazhoginsky deposit with a carbon content of an average of 30% by weight and being in an amorphous state in the form of fullerene.

Description

The utility model relates to electrophysical and electrochemical processing methods and can be used in power engineering to obtain on the surface of aluminum wires overhead power lines of an electrically conductive coating with anti-icing and heat-insulating properties that shields electromagnetic radiation.

The closest technical solution to the proposed utility model is an electrode for electric spark alloying according to USSR author's certificate No. 1366333 A1, MPK V23N 9/00, V23N 1/06, 01/15/1988, made of schungite and used to increase the heat transfer of steel pipes from waste heat boilers for due to a decrease in the adhesion ability of the combustion products to their surface.

The main disadvantage of the known electrode for electrospark alloying is the production of schungite coating on the surface of products, which lack de-icing properties. This is due to the fact that shungite coating was applied by an electrode made of shungite with a high (up to 94% by weight) carbon content on steel products of 20K.

The objective of the utility model is the development of an electrode for producing an electric spark alloying shungite coating with enhanced anti-icing properties on the surface of aluminum wires of overhead power lines.

To solve this problem, the electrode used in the electric alloying of aluminum wires of overhead power lines to obtain such a coating with enhanced anti-icing properties should be made of a material with a low carbon content, having good electrical conductivity and low cost.

The technical result is achieved in that the electrode for spark alloying made of a material containing carbon in an amorphous state in the form of fullerene, while shungite is used as a material containing carbon, according to the proposed utility model, is made of schungite of the Zazhoginsky deposit with carbon content, constituting an average of 30% by weight, for electric spark alloying of aluminum wires of overhead power lines.

Thus, the technical result is achieved through the use of shungite of the Zazhoginsky deposit as the material from which the electrode is made for electrospark alloying of aluminum wires of overhead power lines in order to obtain an electrically conductive coating with enhanced anti-icing properties on their surface. In addition, shungite coating will reduce heat loss during anti-icing heating of the wires, reduce electromagnetic radiation from the wires and increase their electrical conductivity.

In the proposed electrode for electric spark alloying of aluminum wires of overhead power lines, the material used to make the electrode is the natural fossil carbon-containing mineral shungite of the Zazhoginsky deposit with a low carbon content (30% on average by weight). In this material, carbon is in an amorphous state in the form of shungite carbon and has a fullerene regular structure.

Fullerene is a special form of carbon due to the fact that the C ₆₀ fullerene molecule is an organic molecule, and the crystal formed by such molecules, fullerite, is a molecular crystal that acts as a link between organic and inorganic matter. The fullerite crystal has a density of 1.7 g / cm ³ , which is significantly lower than the density of graphite (2.3 g / cm ³ ) and diamond (3.5 g / cm ³ ).

Shungite of the Zazhoginsky deposit contains carbon, on average, 30% by weight, in the form of fullerene and 57% silicon dioxide. With this composition, shungite of the Zazhoginsky deposit is the only natural mineral that conducts electric current. The electrical conductivity of shungite is (1 ... 3) × 10 ³ sim / m, the mechanical compressive strength is 1000 ... 1200 kts / cm ³ , the thermal conductivity is 3.8 W / (m × K). The average value of the coefficient of thermal expansion in the temperature range of 20 ... 600 ° C is 12 × 10 ^-6 1 / deg. The density of shungite is 2.1-2.4 g / cm ³ , porosity is up to 5%. The cost of shungite is 190 rubles / kg.

The essence of the proposed electrode for electrospark alloying of aluminum wires of overhead power lines to combat icing is to create an intermediate layer between the ice and the protected surface of the aluminum electric wire, which, due to the small friction forces between the ice and the coating, reduces the likelihood of ice crystals forming.

An example of a specific implementation.

The only deposit of shungite rocks with a low carbon content (on average by weight - 30%) that can be used to make an electrode to obtain an anti-icing coating with electrospark doping, the Zazhoginsky deposit, is located in the Medvezhyegorsky district of the Republic of Karelia, 5 km from the shipping lip Onega Lake.

In the proposed electrode for electrospark alloying of aluminum wires of overhead power lines, the material of which the electrode is made is shungite of the Zazhoginsky deposit, which according to the certificate has the following chemical composition (wt.%):

Calcined residue H ₂ O in a crystalline bound state. SiO ₂ C Ai ₂ o ₃ FeO K ₂ O S MgO Cao Na ₂ O TiO ₂ 57.0 30,0 4.0 2.5 1,5 1,2 1,2 0.3 0.2 0.2 0.2 1.7

A sample of aluminum grade A5, on which the schungite coating was applied, had dimensions of 50 × 30 × 10 mm. Electrospark alloying with an electrode made of schungite from the Zazhoginsky deposit was carried out using an ultrasonic device IL100-2 with a hand-held ultrasonic tool for attaching an electrode made of schungite.

As a result of alloying with an electrode made of schungite of the Zazhoginsky deposit, mechanical destruction of the material of the anode electrode (schungite) and the formation of secondary structures in its working part occur. At the same time, shungite erosion products are transferred to the coated aluminum part (cathode), on the surface of which processes associated with the diffusion of fullerene C ₆₀ from the alloying material to the surface of the part proceed. The resulting coating surface had a dark gray color with a metallic sheen.

The power of the spark generator during coating was 180 watts. The thickness of the coating layer was 90 μm. The coating thickness was measured on a slice under a MIM-8 microscope. The roughness of the outer surface of the coating was measured by a TR100 profilometer and amounted to Ra = 6.5 μm with a base length of Sm = 2.5 mm, and the surface roughness of the aluminum sample on which the coating was applied was Ra = 0.8 μm with a base length of Sm = 2, 5 mm.

The following properties were tested on the surface of an aluminum sample of schungite coating:

1. The adhesive ability of shungite coating in relation to ice.

2. Thermal conductivity of shungite coating.

3. The shielding properties of shungite coating in relation to electromagnetic radiation.

4. The electrical conductivity of shungite coating.

5. Mechanical strength.

The adhesive ability of shungite coating with respect to ice was measured by the separation method using the "Adhesimeter OR". During the tests, ice samples of cylindrical shape were pre-frozen. Then these samples were frozen at a temperature of -6 ° C to aluminum samples with schungite coating and without coating. Using the OP Adhesion Tester, ice adhesion was measured by tearing. The results of measurements of ice adhesion to aluminum samples with shungite coating and without coating, given in the table, show that the application of shungite coating reduces the adhesion of ice to aluminum by 38%.

Table Sample Ice freezing temperature, ° С The adhesion of ice on separation, g / cm ² Uncoated aluminum sample -6 500 An aluminum sample with shungite coating obtained by alloying with an electrode for electrospark alloying made of schungite from the Zazhoginsky deposit -6 310

The thermal conductivity of shungite coating on aluminum was measured with an ITS-1-2 thermal conductivity meter and amounted to 3.6 W / (m × K). The thermal conductivity of uncoated aluminum was 230 W / (m × K). The shielding properties were measured on a coating 1.2 mm thick, deposited by schungite on an aluminum wire with a diameter of 5 mm, while passing through it an alternating current with a frequency of 50 Hz and a voltage of 220 V using a P3-70 / 1 meter of alternating electric fields. For aluminum wire with schungite coating, in comparison with an aluminum wire without coating, a decrease in the electric field strength by 15 V / m is obtained. The electric resistance value of the schungite coating, measured using a digital ohmmeter 3541, in terms of electrical conductivity was 1400 Ohm ^-1 · m ^-1 (1400 sim / m). The compressive strength of shungite coating, measured by the ONIX-2.5 device, was 104 MPa.

Using the utility model will allow to obtain a schungite coating with enhanced anti-icing properties on the surface of aluminum wires of overhead power lines.

Thus, the use of shungite of the Zazhoginsky deposit as the material from which the electrode is made for electric-spark alloying of aluminum electric wires of overhead power lines will allow to obtain a sufficiently mechanically strong shungite coating that increases the anti-icing properties of aluminum wires of overhead power lines.

In addition, shungite coating will reduce heat loss during anti-icing heating of the wires, reduce electromagnetic radiation from the wires and increase their electrical conductivity.

Claims (1)

An electrode for electric spark doping of aluminum wires of overhead power lines made of schungite from the Zazhoginsky deposit with an average carbon content of 30% by mass and in an amorphous state in the form of fullerene.