JPS59196507A - Insulated wire for skin current heating tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Conventionally, in order to transport fluids that are extremely viscous at room temperature, such as heavy oil and sulfur, it has been efficient to reduce the viscosity by heating the transport pipe to a high temperature. but,
At present, no practically excellent means for heating a long tubular body has yet been used.

It takes a lot of power to raise the temperature, but 5FiCT
The method (skin heating) that has been implemented is a transport pipe 4 having a high viscosity fluid passage 5 as shown in FIG. 1(A).
It is used as a method of indirectly heating a plurality of small-sized steel pipes 1 by welding them together in the longitudinal direction around the pipe.

This is a small size (about 25A) steel pipe with high magnetic permeability.
A stranded wire conductor 2 is inserted into the inside, one end thereof is connected to one end of the steel pipe 1, and the other end is connected to the steel pipe 1 via the energizing device 3.
A current closed circuit is formed by the current flowing through the electric wire 2 flowing through the steel pipe 1 as a return path (arrow).

At this time, the current flowing through the steel pipe 1 flows through the inner skin, becoming a so-called skin current and causing the steel pipe 1 to generate heat. (At the same time, the stranded wire conductor 2 itself also generates heat.) However, this type of stranded wire conductor 2
Because it can be drawn inside, it requires an insulating coating with appropriate flexibility and high heat resistance, and silicone rubber has traditionally been widely used.

The silicone rubber also has physical properties.It is usually used in a temperature range of 180℃ or less, and when the temperature of the heated object is high, such as in higher-temperature pipelines (for example, sulfur / ξ isoline), fluorine-based resin-coated insulated wires are used. has been done. However, fluorine-based resin insulated wires suffer from dielectric breakdown under conditions where ionization, or corona discharge, occurs, so they cannot be used stably for long periods of time, and are generally used in low-voltage circuits of 600 V or less. The Nito Somari that was used, S EOT
The reality is that it is not possible to heat long pipes all at once, which is the original feature of this method, and it is only applied to short pipes.

The object of the present invention is to improve the drawbacks of the conventionally used heating tube using the 5ECT method, as described above, and to provide an insulated wire that is inserted into a small steel pipe that effectively heats the entire long transport pipe. By using a fluorine-based resin with excellent heat resistance for the insulating layer, we have invented an article that is excellent as a high temperature resistant insulator for skin current heating tubes.

The insulated wire of the present invention is made by forming a layer of inorganic material such as glass or mica, which is conventionally known as an insulating material, on the surface of a stranded wire conductor and bonding it with a heat-resistant synthetic resin or rubber. It has a structure in which a fluororesin-treated inorganic tape is wound to protect the inorganic material layer and enhance the insulation effect, and a fluororesin coating layer is further provided to cover the inorganic material layer.

The fluorine-based resin may be a generally known tetrafluoroethylene polymer or a partially chlorinated resin.

To explain this with reference to the drawings below, Fig. 1 shows the conventional 81', OT heating method for transport pipes, as described above, where ■ is a small-sized steel pipe, 2 is a stranded conductor, and 3 is a stranded wire conductor. AC and DC power supply devices, 4 a high viscosity fluid transport pipe, and 5 a high viscosity fluid passage.

The present invention relates to an improvement of the small-sized steel pipe shown in FIG. 1(B), an example of which is shown in FIG.
An insulating layer 22 made of an inorganic material is formed on the surface of the insulating layer 22, an inorganic tape 23 coated or impregnated with a fluorine-based resin is wound around the entire periphery of the insulating layer 22, and a fluorine-based resin is further applied on top of the inorganic tape 23. A coated layer 24 is provided.

As described above, the insulated wire of the present invention has a triple layer (22, 23, 24) of insulating material on the surface of the stranded wire conductor 21, so it is possible to maintain a high temperature rating and a high corona discharge voltage value. This makes it possible to improve corona resistance compared to conventional products that simply provide a fluorine-based resin layer on the current-carrying wire.
This insulated wire is more stable at high temperatures than silicone rubber.

Furthermore, since the outermost layer of the electric wire is made of the fluorine-based resin layer 24, even if a water-infiltrated portion occurs in the small-sized steel pipe, it has excellent water resistance and can safely maintain a long service life.

Note that the insulating layer 22 made of an inorganic material is subjected to subsequent processing, that is, when the outermost fluorine-based resin coating layer 24 is provided, the inorganic material layer 21 is also forced to be heated, and the contained moisture, adhesive, etc. The fluorine-based resin layer 24 is formed by vaporizing a small amount of solvent.
However, the tape 23 having a fluorine-based resin layer plays an important role in blocking this vaporized gas.

5- In this way, due to the structure of the durable insulated wire, as mentioned above, no layer can be omitted, and due to the interrelationship of the three layers, it has a forming layer that satisfies all effects. .

Inorganic tapes include glass fiber woven fabrics, non-woven fabrics,
It is made from a sheet-like material mixed with mica and short glass fibers. Furthermore, the use of heat-resistant synthetic or natural fibers or molded products as tape materials is not excluded.

In addition, the results of measuring the corona discharge voltage value of the insulated wire according to the present invention show a value of 4 KV to 4.5 KV, and even considering the facility loss in practical use, it is not suitable for circuits with a rated voltage of 3 KV or more. It is durable enough for use.

Incidentally, the corona discharge voltage value is I KV to 2 KV higher than that of an electric wire in which the surface of the stranded wire conductor 21 is coated with only the fluorine-based resin coating layer 24 directly below, which is essential for use in high-voltage circuits. belongs to.

As explained in detail above, according to the insulated wire according to the present invention,
It has both high water resistance and heat resistance, and shows sufficient resistance to destruction by corona discharge, and can be drawn into long small-sized steel pipes such as those used for heating high-viscosity flow pipes, and can be heated to high temperatures by applying high voltage. It has revolutionary practical value in the field as an insulated wire for skin current heating tubes that can withstand temperatures (180°C or higher).

[Brief explanation of drawings]

Fig. 1 (A) is an outer diameter sectional view showing a heating mode by a small-sized steel pipe welded to a high viscosity fluid transport pipe, (+3) is a perspective view showing a conventional skin current heating tube, and Fig. 2 is a diagram according to the present invention. A cross-sectional view and a side view showing an insulated wire are shown. ■・・・Heating tube, 2...Twisted wire conductor, 3
...Electrification device, 4...High viscous fluid transport pipe, 5...Viscous fluid passage, 21... Stranded wire conductor, 22... ...Inorganic material layer, 23...
...Fluorine resin layer forming tape, 24...Fluorine resin coating layer. 7- Arithmetic 1 Figure, A, (B)'lz
Figure 35-

Claims (1)

[Claims] In an insulated wire that is inserted into a tube with high magnetic permeability and connected to the end of the tube to form a current closed circuit, the surface of the stranded wire conductor is covered with an insulating layer mainly made of inorganic material, and the surface is coated with fluorine. An insulated wire for a skin current heating tube to be inserted into a highly magnetically permeable tube, characterized by winding an inorganic tape coated with or pasted with a resin, and further providing a coating layer of fluororesin to cover the tape. .