JPS5848305A - Explosion preventive refractory cable - 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 The present invention relates to an explosion-proof and fire-resistant cable containing only small amounts of organic material.

Electrical wires installed in petroleum plants, chemical plants, etc. must have excellent explosion-proof properties to prevent explosion accidents, and excellent corrosion resistance so that they can be used for long periods of time even in environments where various chemical substances are present. is necessary. Conventionally, as an electric wire employed for this type of use, there is an M cable, in which a plurality of conductors inserted into a steel pipe are isolated by filling with magnesium oxide powder.

This MI cable is manufactured by stretching a thick copper pipe filled with magnesium oxide powder to a specified size, so its length is limited, and the work of connecting the MI cable is extremely difficult due to the moisture absorption of magnesium oxide. be.

The present invention, as a result of repeated research and consideration of the above-mentioned problems regarding the conventional explosion-proof cable, M-cable, has succeeded in manufacturing an explosion-proof and fire-resistant cable that can replace the V-cable. Accordingly, an object of the present invention is to provide an explosion-proof fireproof cable which has excellent fire resistance because it contains only a small amount of organic material, and which has excellent flexibility and corrosion resistance because the outer periphery is a metal tube.

To explain the present invention with reference to the drawings, FIG. 1 shows an example of an explosion-proof fireproof cable according to the present invention. The explosion-proof fireproof cable 1 has a plurality of conductors 2 (three in the drawing) made of copper or aluminum, and a glass mica tape 3 is wound around each conductor. The glass mica tape 3 is manufactured by bonding a glass fiber cloth with an adhesive so that the mica group is spread over the entire surface on one or both sides, or
It is manufactured by laminating glass fiber cloth on both sides of a strength foil, and the mica base can be exemplified by laminated mica, soft peelable mica, or hard mica, and the adhesive used can be silicone resin or epoxy resin. The distance between wraps and the number of layers are determined depending on the insulation resistance of the mica group to be bonded to one side of the glass fiber cloth. At this time, the winding tape 3 is wrapped in a different color for each conductor 2, such as black, red, or white (
If the wire is colored (natural color), it becomes possible to identify the wire core. In addition, when winding the tape 3 around each conductor 2 vertically,
You can color them individually.

The plurality of conductors 2 wound with tape 3 are pressed and wound with metal tape 5 while converging with a filler 4 interposed therebetween as desired. The filler 4 is used to arrange the cable 1 into a circular cross section and to maintain the spacing between the conductors 2, so it may be unnecessary if the number of layers of the winding tape 30 is increased. Examples of the filler 4 include multifilament glass fibers or other inorganic fibers, and other inorganic fibers include quartz fibers, silica fibers, and ceramic powders (eg, Kao Wool (trade name)). Metal tape for winding the presser foot 5
is used to protect and insulate the conductor 2 and is made of copper or aluminum, for example.

After pressing and winding the metal tape 5, the straight pipe or corrugated pipe is covered with a metal pipe 6 to obtain the cable 1. The metal tube 6 may be made of iron, steel, aluminum, or copper, but is preferably made of stainless steel from the viewpoint of corrosion resistance, especially in an environment where there is a risk of corrosion. To form a straight metal tube, for example, when performing public arc welding, a conductor bundle pressed and wrapped with metal tape 5 is sent together with a metal band, and to form a corrugated metal tube 6, it is welded into a tube shape. Then, it is corrugated by cold corrugating. This allows the corrugation to cover the metal tube 6, and the vertical cross section of the metal tube is corrugated, which not only suppresses the conductor bundle but also improves the flexibility of the cable itself.

The cable 7 shown in FIG. 2 has a single core, and after wrapping a glass mica tape 8 around the conductor 2 and further wrapping a metal tape 5, the straight or corrugated cable is covered with a metal tube 6.

In this case, it is not necessary to use the filler 4 as described above, but in order to maintain a certain level of fire resistance, the wrapped tape 8
The number of layers is greater than that of tape 3 described above.

In the cable 9 shown in FIG. 3, the conductor 2, filler 4, metal tape 5, and corrugated metal tube 6 are the same as described above, but the glass mica tape 3 is replaced by a fire-resistant inorganic material.
O is deposited on each conductor 2. The inorganic material 1O is a ceramic powder such as magnesium oxide, alumina, or aluminum oxide, which is mixed with a heat-resistant liquid adhesive such as silicone resin or epoxy resin and used in a bath of the resulting mixture. By inverting the conductor 2 into the core and curing it, the inorganic material 10 can be deposited on the core conductor. In order to increase the layer thickness of the inorganic substance 10, the conductor may be repeatedly passed through the bath of the mixed liquid, and the number of cores of such a cable may be double.

The explosion-proof and fire-resistant cable according to the present invention contains only a small amount of organic material, so it can be used again at about 1200 degrees Celsius.Like the MI cable, it can be used for wiring in flight towers, thermal power plants, and various plants. Can be used for erection. Since the outer periphery of the cable of the present invention is a straight pipe or a corrugated metal pipe, it will not corrode even if exposed for a long time like a normal cable, and has good flexibility, making cable installation work easy. be. Regarding corrosion resistance, it is more effective if the outer periphery of this cable is made of stainless steel. Furthermore, the cable of the present invention has the advantage that it can be manufactured in a longer length than the MI cable, and the cable can be easily connected, so that it can be manufactured at a lower cost.

A copper wire with a diameter of 2.5 mm was used as the conductor 2, and a conductor with a thickness of 0.13 mm was laminated with a mica base and a glass fiber cloth.
Three layers of glass mica tape 3 having a diameter of 1.5 mm are wound on the conductor 2 with an interval of 1/2 lamp. A glass fiber filament is interposed as a filler 4, three conductors 2 are twisted together at a pitch of about 200 mm, and an aluminum tape 5 with a thickness of Q and 1 mm is formed.
Press and wrap at 115 to 1/4 wrap intervals. Next, the corrugation with a thickness Q of 3 mm is contacted by a stainless steel pipe 6, but the inner diameter of the steel pipe is l Q, mm and the outer diameter is 1
It is 3 to 14 mm. As a result, an explosion-proof fireproof cable l as shown in No. 11'21 is obtained.

[Brief explanation of the drawing]

FIG. 1 is an enlarged partial perspective view of an explosion-proof fireproof cable according to the present invention, and FIGS. 2 and 3 are enlarged sectional views showing modifications of the present invention. l...Explosion-proof fireproof cable, 2...Conductor, 3...Glass mica tape, 4...Filler, 5...Metal tape, 6...Corrugated metal tube. Applicant Kyowa Electric Cable Co., Ltd. Agent Patent Attorney Akio Kanzaki Procedural amendment (voluntary) March 20, 1980 Commissioner of the Patent Office Tono 1, Indication of the case 1981 Patent Application No. 147194 2, Title of the invention Explosion-proof fireproof cable 3. Relationship with the case of the person making the amendment Patent applicant address: 2-5 Kusune Kita-cho, Neyagawa-shi, Osaka Name) Kyowa Electric Cable Co., Ltd. 4, Agent 8 Contents of the amendment (1) Scope of patent claims Correct as shown in the attached sheet. (2) On page 4 of the specification, lines 12 to 14, the phrase ``For presser winding...'' was replaced with ``For presser winding of conductor 2,
Although a metal tape 5 made of copper or aluminum, for example, is used to protect and insulate the conductor, other inorganic tapes such as glass cloth, single-glass mica, or other inorganic tapes may also be used. ” he corrected. 2. Claim 1: Wrap a glass mica tape around the conductor or attach a fire-resistant inorganic material around it, and then apply one of the conductors.
An explosion-proof and fireproof cable characterized in that a book or a plurality of books are bundled, pressed and wound, and then covered with a metal tube. 2. The cable according to claim 1, characterized in that a filler of glass fiber or other inorganic fiber is interposed when the plurality of conductors are bundled and pressed and wound. 3. The cable according to claim 1, wherein the coated metal tube is a straight tube or a corrugated tube made of stainless steel.

Claims (1)

[Claims] 1. A glass mica tape is wound around the conductor or a fire-resistant inorganic material is attached around it, and then one of the conductors is
An explosion-proof and fireproof cable characterized by condensing a book or a plurality of books, pressing and wrapping them with a metal tape, and then covering the cable with a metal tube. 2. The cable according to claim 1, wherein a filler of glass fiber or other inorganic fiber is interposed when the plurality of conductors are bundled and pressed and wound. 3. The cable according to claim 1, wherein the coated metal tube is a straight tube or a corrugated tube made of stainless steel.