RU206591U1 - The wire - Google Patents

Abstract

The utility model relates to the field of electrical engineering, namely to wires intended for stationary laying in electrical installations, in lighting networks, for inter-device installation of electrical equipment, machines, mechanisms, devices for a rated voltage of up to 660 V and a frequency of 50 Hz, and can be used in various industries (ferrous / non-ferrous metallurgy, oil production, chemical industry, etc.). The wire includes a conductive core with four layers of insulation. The first layer is made of silica filaments, the second layer is made of fluoroplastic, the third layer is made in the form of a winding of basalt filaments and covered with heat-resistant varnish. The wire is equipped with a fourth layer of insulation made in the form of a braid of basalt threads. The first and third layers of insulation are impregnated with heat-resistant varnish and made with a thickness of 0.3 mm to 1.8 mm. The second layer of insulation is made with a thickness of 0.04 mm to 0.12 mm. The fourth layer of insulation is made with a thickness of 0.25 mm to 0.8 mm. The technical result is an increase in the electrical resistance of the insulation by increasing the resistance to aggressive media, high-temperature and mechanical stress.

Description

The utility model relates to the field of electrical engineering, namely to wires intended for stationary laying in electrical installations, in lighting networks, for inter-device installation of electrical equipment, machines, mechanisms, devices for a rated voltage of up to 660 V and a frequency of 50 Hz, and can be used in various industries (ferrous / non-ferrous metallurgy, oil production, chemical industry, etc.).

The closest in technical essence is a wire containing a conductive core, equipped with two layers of asbestos insulation based on an assembly, impregnated with heat-resistant impregnation, with a PTFE film placed between them (patent RU31870, publ. 25.02.2003). The wire is designed for high temperature operation.

However, the known technical solution, selected as a prototype, is characterized by low reliability. This is due to the fact that the layers of asbestos insulation are very fragile and as a result of exposure to aggressive environments, mechanical influences, their integrity is violated. In addition, prolonged high-temperature exposure also accelerates the process of destruction of the asbestos insulation layer due to material fatigue, which also leads to a violation of the insulation integrity, a decrease in dielectric strength (a decrease in the ability to withstand the effects of breakdown voltages) and, consequently, a decrease in the electrical resistance of the insulation. As a result, there is a leakage of current and the danger of operating such a wire increases, which leads to the need to replace it. In addition, the known wire has low environmental friendliness and is dangerous for use, since asbestos materials are a carcinogen of the first category according to the classification of the International Agency for Research on Cancer (IARC), which limits its scope and requires the use of additional safety measures during operation.

A technical problem is the creation of a reliable wire with high electrical insulation resistance values.

The technical result is to increase the resistance to aggressive media, high-temperature and mechanical stress.

The technical result is achieved due to the fact that the wire, including a conductive core with three layers of insulation, the second of which is a PTFE film, according to the utility model, is equipped with a fourth layer in the form of a braid of basalt threads, while the first layer is made of silica filaments, and the third layer is made in the form of a winding of basalt threads and is also covered with heat-resistant varnish.

In private embodiments, the first layer of insulation is impregnated with a heat-resistant varnish; and / or the first and third layers of insulation are made with a thickness of 0.3 mm to 1.8 mm; and / or the second layer of insulation is made with a thickness of 0.04 mm to 0.12 mm; and / or the fourth layer of insulation is made with a thickness of 0.25 mm to 0.8 mm.

The claimed design features of the wire provide an increase in resistance to aggressive media, high-temperature and mechanical stress. So the use of silica filaments, which have low thermal conductivity, causes an increase in the dielectric properties of the first layer, an increase in resistance to high temperatures. At the same time, the implementation of the third layer of basalt threads in the form of a winding impregnated with heat-resistant varnish also increases the resistance to high temperatures, protecting the first and second layers, and supplying the wire with a fourth layer made of basalt threads in the form of a braid makes it possible to reduce the negative effect of aggressive media, mechanical and high temperature impacts on all inner layers of insulation. The above together increases the electrical resistance of the insulation.

Private versions of the wire additionally contribute to an increase in resistance to aggressive environments, high-temperature and mechanical influences, and, consequently, an increase in the electrical resistance of insulation, depending on the operating conditions of the wire: varying the ratio of layer thicknesses and the possibility of their additional impregnation with heat-resistant varnish allows you to select the optimal required indicators electrical resistance, taking into account economic and other factors (cost, reduced material consumption, flexibility of the wire, etc.).

The claimed utility model is illustrated by a drawing, where FIG. the general view of the wire is presented (cross-section).

The wire includes a conductive core 1, which is one stranded copper core (strand).

Vein 1 is covered with the first layer of insulation 2, made of silica filaments coated with heat-resistant varnish. On top of the first layer 2, the second layer 3 is superimposed in the form of a film made of fluoroplastic F-4. Next, there is a third layer 4 in the form of a winding of basalt threads, covered with a heat-resistant varnish. Execution of the third layer in the form of a winding, i.e. by applying basalt threads along a helical spiral, impregnated with heat-resistant varnish, it allows to obtain a thin, not increasing specific gravity, but effective heat-insulating layer. The outer layer 5 is made in the form of a braid of basalt threads (cover of interwoven basalt threads); the execution of the last layer in the form of a braid makes it possible to obtain a dense layer that holds its shape well, which, together with the used basalt threads, determines its wear resistance, chemical resistance and resistance to high temperature influences.

The first 2 and third 4 layers are always impregnated with a heat-resistant varnish, for example, silicone varnish.

The thicknesses of the layers are selected depending on the required operating conditions with the provision of high electrical insulation resistance values. So the first and third layers of insulation can be made with a thickness of 0.3 mm to 1.8 mm, the second layer of insulation can be made with a thickness of 0.04 mm to 0.12 mm, and the fourth layer of insulation can be made with a thickness of 0, 25mm to 0.8mm.

The claimed wire is illustrated by the following examples.

Example 1

In an electrical installation in a chemical plant (hydrochloric acid production), a wire is used with the following characteristics:

the first layer (made of silica filaments) is 0.5 mm thick;

the second layer (PTFE-4 film) is 0.05 mm thick;

the third layer (winding of basalt threads) is made with a thickness of 1.5 mm;

the fourth layer (braid of basalt threads) is 0.8 mm thick;

The operation of the wire was carried out for 6 months in conditions of high humidity and temperature (20 ° C and 95-98%, respectively). The electrical resistance was assessed three times, 1 month, 3 months. and 6 months. operation by measuring with a megohmmeter under the same conditions. The measurement results showed that the insulation resistance after 1 month. was 5.5⋅10 ¹² Ohm⋅m, after 3 months. - 5.5⋅10 ¹² Ohm⋅m, after 6 months - 5.3⋅10 ¹² Ohm⋅m. The revealed decrease in resistance is insignificant for the continuation of the operation of the wire, thus ensuring the resistance of the wire to aggressive environments and high-temperature influences, which determines its reliability.

Under the described conditions, the prototype wire (with asbestos insulation) was also operated. After its use, measurements of electrical resistance were also carried out: after 1 month. was 3.0⋅10 ¹¹ Ohm⋅m, after 3 months. - 2.5⋅10 ¹² Ohm⋅m, after 6 months - 2.0⋅10 ¹² Ohm⋅m. Such indicators of electrical resistance are unacceptable according to TU 27.32.13-002-23534359-2018, and the wires must be replaced.

Example 2

In lighting networks at a non-ferrous metallurgy enterprise, a wire is used with the following characteristics:

the first layer (of silica filaments) is 1.7 mm thick impregnated with organosilicon varnish;

the second layer (PTFE-4 film) is 0.12 mm thick;

the third layer (winding of basalt threads) is 1.0 mm thick;

the fourth layer (braid of basalt threads) is made with a thickness of 0.5 mm; The operation of the wire was carried out for 6 months in conditions of high humidity and temperature (300 ° C and 60-65%, respectively). The electrical resistance was assessed three times, 1 month, 3 months. and 6 months. operation by measuring with a megohmmeter under the same conditions. The measurement results showed that the insulation resistance after 1 month. was 6.2⋅10 ¹² Ohm⋅m, after 3 months. - 6.0⋅10 ¹² Ohm⋅m, after 6 months. 6.0⋅10 ¹² Ohm⋅m. The revealed decrease in resistance is insignificant for the continuation of the operation of the wire, thus ensuring the resistance of the wire to aggressive media, mechanical and high-temperature influences, which determines its reliability.

Under the described conditions, the prototype wire (with asbestos insulation) was also operated. After its use, measurements of electrical resistance were also carried out: after 1 month. was 3.2⋅10 ¹¹ Ohm⋅m, after 3 months. - 2.1⋅10 ¹² Ohm⋅m, after 6 months. - 1.8⋅10 ¹² Ohm⋅m. Such indicators of electrical resistance are unacceptable according to TU 27.32.13-002-23534359-2018, and the wires must be replaced.

Example 3

In lighting networks at oil production enterprises, a wire with the following characteristics is used:

the first layer (of silica filaments) is 1.0 mm thick impregnated with organosilicon varnish;

the second layer (PTFE-4 film) is 0.85 mm thick;

the third layer (winding of basalt threads) is made with a thickness of 0.7 mm;

⋅ the fourth layer (braid of basalt threads) is made with a thickness of 0.6 mm; The operation of the wire was carried out for 6 months in conditions of high humidity and temperature (200 ° C and 60-65%, respectively). The electrical resistance was assessed three times, 1 month, 3 months. and 6 months. operation by measuring with a mega ohmmeter under the same conditions. The measurement results showed that the insulation resistance after 1 month. was 6.4⋅10 ¹² Ohm⋅m, after 3 months. - 6.4⋅10 ¹² Ohm⋅m, after 6 months - 6.4⋅10 ¹² Ohm⋅m. The revealed decrease in resistance is insignificant for the continuation of the operation of the wire, thus ensuring the resistance of the wire to aggressive media, mechanical and high-temperature influences, which determines its reliability. Example 4

In the lighting networks at the mining and processing plant, a wire with the following characteristics is used:

the first layer (of silica filaments) is 1.8 mm thick;

the second layer (PTFE-4 film) is 0.12 mm thick;

the third layer (winding of basalt threads) is 1.1 mm thick impregnated with organosilicon varnish;

the fourth layer (braid of basalt threads) is 0.8 mm thick; The operation of the wire was carried out for 6 months in conditions of high humidity and temperature (20 ° C and 60-65%, respectively). The electrical resistance was assessed three times, 1 month, 3 months. and 6 months. operation by measuring with a megohmmeter under the same conditions. The measurement results showed that the insulation resistance after 1 month. was 6.4⋅10 ¹² Ohm⋅m, after 3 months. - 6.4⋅10 ¹² Ohm⋅m, after 6 months - 6.4⋅10 ¹² Ohm⋅m. The revealed decrease in resistance is insignificant for the continuation of the operation of the wire, thus ensuring the resistance of the wire to aggressive media, mechanical and high-temperature influences, which determines its reliability.

The examples given show that, depending on the operating conditions, varying the ratio of layer thicknesses and the possibility of their additional impregnation with heat-resistant varnish allows you to select the optimal required electrical resistance indicators, taking into account economic factors (reduced material consumption, wire flexibility, etc.).

Thus, the claimed useful model is the creation of a reliable wire with high electrical resistance of insulation due to increased resistance to aggressive media, high-temperature and mechanical stress.

Claims (5)

1. A wire including a conductive core with three layers of insulation, the second of which is a PTFE film, characterized in that it is equipped with a fourth layer in the form of a braid of basalt threads, while the first layer is made of silica filaments, and the third layer is made in the form of a winding made of basalt threads and covered with heat-resistant varnish 5. 2. Wire according to claim 1, characterized in that the first layer of insulation is impregnated with a heat-resistant varnish. 3. Wire according to claim 1, characterized in that the first and third layers of insulation are made with a thickness of 0.3 mm to 1.8 mm. 4. Wire according to claim 1, characterized in that the second layer of insulation is made with a thickness of 0.04 mm to 0.12 mm. 5. Wire according to claim 1, characterized in that the fourth layer of insulation is made with a thickness of 0.25 mm to 0.8 mm.

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