JPS593512Y2 - Terminal of long heater - Google Patents

Description

[Detailed description of the invention] The present invention is a long heater that is buried in the soil and used to heat the soil in order to prevent the soil from freezing around an underground tank storing liquefied gas, etc. This relates to improvements to the terminal section.

In general, this type of long heater consists of an inorganic insulated heating wire, a flexible corrugated metal tube placed around the inorganic insulated heating wire, and a flexible corrugated metal tube placed to embed the inorganic insulated heating wire. This is due to the inorganic insulating filler filled inside the pipe
2-42497).

In this prior art, the inorganic insulated heating wire is manually pushed into the corrugated metal tube from the open end on the opposite side. The distance between the end and the terminal cap is not constant, and the heating wire may be offset from the center of the corrugated metal tube, which causes heat radiation from the surface of the corrugated metal tube to be radiated both vertically and radially. It also had the disadvantage of being non-uniform.

SUMMARY OF THE INVENTION An object of the present invention is to provide an end portion of a long heater that allows longitudinal and radial heat radiation to be set as desired.

An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a long heater 12 equipped with a terminal portion 10 according to the present invention.
This long heater includes an inorganic insulated heating wire 14, a flexible spiral corrugated metal tube 16 arranged to surround the heating wire, and a flexible spiral corrugated metal tube 16 arranged to surround the heating wire 12. The inorganic filler 18 filled in the tube 16 should be avoided.

The inorganic insulated heating wire 14 has an inorganic insulating material such as magnesium oxide and a heating wire made of copper, aluminum, nickel, chromium, etc. kept watertight in a metal tube sheath formed by extruding stainless steel, aluminum, copper, etc. It is filled and formed.

In the illustrated embodiment, the heating line is set to -6 and is folded back at a simple 20 near the lower end to form the existing line and the return line.

However, the heating wire may be made into two cores, with a live wire and a return wire, but even in this case, the wire should be folded back at the simple 20.

As shown in FIG. 3A, this inorganic insulated heating wire 14 is pulled by a simple wire 22 and introduced into a flexible spiral corrugated metal tube 16 which is open at both ends.

A corrosion-resistant vinyl chloride coating 24 is provided on the outer surface of the flexible spiral corrugated metal tube 16, but the coating 24 is omitted if the metal tube 16 itself is made of a corrosion-resistant material. be able to.

The inorganic filler 18 is made of alumina powder, gypsum, or alumina powder mixed into gypsum, which has relatively good thermal conductivity and is excellent in explosion resistance.

The end portion 10 of the elongated heater of the present invention further includes an end cap 26 that is screwed into the end opening of the flexible spirally corrugated metal tube 16, as shown in detail in FIG.

As already mentioned, after the heating wire 14 is introduced into the metal tube 16 by the wire 22, the heating wire 14 is connected to the terminal cap 26 near the end of the metal tube 16 by the simple 20 and the end cap 26 using a connector to be described later. The end cap 26 is then screwed into the end opening of the metal tube 16 (see FIG. 3B).

After peeling off the coating 24 on the end of the flexible spiral corrugated metal 16 and welding the flange 26a of the end cap 26 to the metal tube 16 as shown at 30, the coating 24 is peeled off as shown in FIG. A self-adhesive sealing tape 28 is wrapped around the sealed portion.

Next, as shown in FIG. 2, a corrosion-resistant end coating 32 such as vinyl chloride is placed over the end cap 26, sealing tape 28, and metal tube sheath 24, and the end cap 26, sealing tape 28, and metal tube sheath 24 are covered with a corrosion-resistant end sheath 32, such as vinyl chloride. Adhesive tape 34 is then wrapped.

As can be seen from FIG. 3B, since the terminal cap 26 is of a screw type, it does not fall off from the metal tube 16.
Its welding work is easy.

Connector 36 is separated from wire 38 and untwister 40, as shown in FIG.

The wire 38 may be the pulling wire 22 cut to a predetermined length, and the untwisting device 40 has a mounting screw 40a that is screwed into the central threaded hole 26b of the end cap 26.

This untwister 40 is commercially available and has the function of preventing the heating wire 14 from being twisted when screwing the mounting screw 40a into the end cap 26 and when screwing the end cap 26 into the metal tube 16.

Further, it can be seen that the terminal position of the heating wire 14, that is, the folding position, is set for the connecting tool 36 from the overall length.

According to the present invention, as described above, the connector that connects the heating wire and the terminal cap facilitates centering of the heating wire and allows setting the end position of the heating wire to a predetermined value. It is possible to obtain a long heater having a heat generation distribution of .

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a part of a long heater equipped with a terminal section according to the present invention, Fig. 2 is an enlarged sectional view of the main part of the present invention, and Fig. 3 A and B are a cross-sectional view of a long heater equipped with a terminal section according to the present invention. It is a schematic diagram showing a method of forming. 10...Terminal part, 12...Long cable, 14...Inorganic insulated heating wire, 16...
・Flexible spiral corrugated metal tube, 18...Inorganic filling,
20...Simple, 26...Terminal cap, 30...Welded part, 36...Connector, 38...Wire, 40...・・・・・・Untwisting device.

Claims (3)

[Scope of utility model registration request] (1) an inorganic insulated heating wire, a flexible metal tube disposed surrounding the inorganic insulated heating wire, and an inorganic filler filled in the flexible metal tube so as to embed the inorganic insulated heating wire; The long heater has an end cap that is attached to the end opening of the flexible metal tube and welded so that the ends of the flexible metal tube meet and weld, and the inorganic insulated heating wire is An end portion of a long heater, characterized in that the flexible corrugated metal tube is folded back near the end thereof, and the simple and the end cap are connected by a connector. (2) The terminal portion of the elongated heater according to claim 1, wherein the connector is a wire. (3) Claims for registration of a utility model, characterized in that the connector further includes an untwister attached to the end of the wire, and the end of the untwister is attached to the terminal cap. Terminal portion of the elongated heater according to item 2.