Fireproof mineral insulated cable

Abstract

The invention discloses a fireproof mineral insulated cable which comprises a supporting rib, the cross section of the supporting rib is Y-shaped, each included angle space of the supporting rib is provided with a cell conductor, the outer surface of each cell conductor is wrapped with a single-layer semi-conductive belt, the outer surface of each single-layer semi-conductive belt is wrapped with an insulating layer, the outer surface of the supporting rib is wrapped with a first cable wrapping belt, and the outer surface of the first cable wrapping belt is wrapped with a second cable wrapping belt. And gaps among the first cable wrapping tape, the supporting ribs and the cell conductors are filled with fire-retardant layers, the outer surface of the first cable wrapping tape is wrapped with a copper corrugated pipe, and the outer surface of the copper corrugated pipe is wrapped with an oxygen-isolating fire-resistant layer. When the cable is heated, the fire retardant layer of the fire-resistant mineral insulated cable can decompose carbon dioxide, so that the fire can be prevented from spreading to a certain extent; the oxygen-isolating fire-resistant layer can isolate oxygen and flame, and the oxygen-isolating fire-resistant layer is difficult to be ignited by open fire, so that the cable can still work under the condition close to the flame.

Description

Technical Field

[0001] The invention relates to the technical field of cable fire resistance, and in particular to a fire-resistant mineral insulated cable. Background Art

[0002] Fire-resistant mineral insulated cable, also called MI cable or mineral insulated metal sheathed cable, is a high-performance wire and cable product that is widely used in situations where there are strict requirements on fire safety, high temperature stability and electrical continuity.

[0003] However, due to the complex application scenarios of cables and the long-term use of cables, the damage and wear of cables are mainly to the cable core, and the cable core is subjected to large voltage and current. Therefore, when sparks appear in the cable and voltage, they will spread at a faster speed. At the same time, when open flames and high temperatures appear outside, the high-temperature insulating materials around the cable are easily ignited by open flames at the critical temperature, which accelerates the speed of cable damage.

[0004] In view of the above situation, we propose a fire-resistant mineral insulated cable. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to provide a fire-resistant mineral insulated cable.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A fire-resistant mineral insulated cable comprises a supporting rib, wherein the cross section of the supporting rib is in a "Y" shape, a battery conductor is arranged in each angle space of the supporting rib, the outer surface of the battery conductor is wrapped with a single-layer semi-conductive tape, the outer surface of the single-layer semi-conductive tape is wrapped with an insulating layer, and the outer surface of the supporting rib is wrapped with a first cable tape.

[0008] The gaps between the first cable wrapping tape, the support ribs and the core conductors are filled with a fire barrier layer.

[0009] The outer surface of the first cable tape is coated with a copper bellows, the outer surface of the copper bellows is coated with an oxygen-isolating fire-resistant layer, the outer surface of the oxygen-isolating fire-resistant layer is coated with a second cable tape, the outer surface of the second cable tape is coated with a water-blocking layer, and the outer surface of the water-blocking layer is coated with an outer sheath;

[0010] Six groups of carbon fiber tensile ropes are arranged on the inner wall of the gap between the inner sheath and the outer sheath, and the six groups of carbon fiber tensile ropes are embedded in the water-blocking layer.

[0011] Preferably, the outer surface of the insulating layer is in contact with the material of the fire barrier layer.

[0012] Preferably, the main component of the fire barrier layer is sodium bicarbonate.

[0013] Preferably, the first cable tape and the second cable tape are both fire-resistant mica tapes.

[0014] Preferably, the oxygen-isolating refractory layer is a fireproof mud layer made by mixing white jade powder and sodium silicate.

[0015] Preferably, the insulating layer material is ceramic polyolefin.

[0016] The fire-resistant mineral insulated cable proposed by the present invention has the following beneficial effects: the inner wall of the first cable tape is fixedly connected with a support rib, which can keep the cable round and reduce the load on the cable core; a fire-retardant layer composed of sodium bicarbonate is filled between the support rib and the first cable tape, and the fire-retardant layer can decompose carbon dioxide when the cable is heated, which can block the spread of fire to a certain extent; an oxygen-isolating fire-resistant layer composed of a mixture of white jade powder and sodium silicate is arranged on the outer surface of the copper bellows, which can isolate oxygen and flame, and the oxygen-isolating fire-resistant layer is difficult to be ignited by an open flame, so that the cable can continue to work under conditions close to the flame; a carbon fiber tensile rope for bearing the axial load of the cable is arranged between the outer sheath and the inner sheath, and a water-blocking layer for blocking water is filled in the gap between the outer sheath, the inner sheath and the carbon fiber tensile rope. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention provides a schematic structural diagram of a fire-resistant mineral insulated cable.

[0018] In the figure: 1. Support ribs; 2. Battery core conductors; 3. Single-layer semi-conductive tape; 4. Insulation layer; 5. Outer sheath; 6. First cable tape; 7. Fire barrier layer; 8. Copper bellows; 9. Oxygen-isolating and fire-resistant layer; 10. Second cable tape; 11. Inner sheath; 12. Carbon fiber tensile rope; 13. Water barrier layer. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0020] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and work in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] Referring to 1-2, a fire-resistant mineral insulated cable comprises a support rib 1, the cross-section of the support rib 1 is "Y"-shaped, a core conductor 2 is arranged in each angle space of the support rib 1, the outer surface of the core conductor 2 is wrapped with a single-layer semi-conductive tape 3, the outer surface of the single-layer semi-conductive tape 3 is wrapped with an insulating layer 4, the outer surface of the support rib 1 is wrapped with a first cable tape 6, the first cable tape 6 and the second cable tape 10 are both fire-resistant mica tapes, the single-layer semi-conductive tape 3 can homogenize the magnetic field to prevent local discharge in the cable conductor, and the insulating layer 4 is made of ceramic polyolefin, which will form a hard shell after high-temperature sintering to avoid short circuit.

[0022] The outer surface of the support rib 1 is wrapped with a first cable tape 6, and the first cable tape 6 is divided into three spaces by the support rib 1. The core conductors 2 are placed in the three equally divided spaces of the first cable tape 6 respectively; the support rib 1 keeps the cable round and reduces the load on the cable core. The gap between the first cable tape 6, the support rib 1 and the core conductor 2 is filled with a fire barrier layer 7. The main component of the fire barrier layer 7 is sodium bicarbonate. When the cable is heated, the fire barrier layer 7 can decompose carbon dioxide, which can block the spread of fire to a certain extent. The outer surface of the first cable tape 6 is wrapped with a copper bellows 8, and the outer surface of the copper bellows 8 is wrapped with an oxygen-isolating fire-resistant layer 9. The copper bellows 8 can bear radial loads and can also provide The high softness of the cable, the oxygen-isolating and fire-resistant layer 9 is specifically a fire-resistant mud layer made of a mixture of white jade powder and sodium silicate, which can isolate oxygen and flames, the outer surface of the oxygen-isolating and fire-resistant layer 9 is covered with a second cable tape 10, the outer surface of the second cable tape 10 is covered with a water-blocking layer 13, the outer surface of the water-blocking layer 13 is covered with an outer sheath 5, six groups of carbon fiber tensile ropes 12 are arranged on the inner wall of the gap between the inner sheath 11 and the outer sheath 5, the six groups of carbon fiber tensile ropes 12 are embedded in the water-blocking layer 13, the carbon fiber tensile ropes 12 bear the axial load of the cable, the water-blocking layer 13 filled in the gap between the inner sheath 11, the outer sheath 5 and the six groups of carbon fiber tensile ropes 12 can prevent water from penetrating into the interior of the cable.

[0023] In summary: during the application of the present invention, a single-layer semi-conductive tape 3 is wrapped around the outside of the battery core conductor 2, which can homogenize the magnetic field and prevent local discharge in the cable conductor. An insulating layer 4 composed of ceramic polyolefin is wrapped around the outer surface of the single-layer semi-conductive tape 3. The ceramic polyolefin 4 is a granular object. After high-temperature sintering, it will form a hard shell to avoid short circuit. A support rib 1 is fixedly connected to the inner wall of the first cable tape 6 to keep the cable round and reduce the load on the cable core. A fire barrier layer 7 composed of sodium bicarbonate is filled between the support rib 1 and the first cable tape 6. When the cable is heated, the fire barrier layer 7 can decompose carbon dioxide, which can block the spread of fire to a certain extent. The outer surface of the cable tape 6 is provided with a copper bellows 8, which can bear radial loads and improve the softness of the cable. An oxygen-isolating and fire-resistant layer 9 made of a mixture of white jade powder and sodium silicate is provided on the outer surface of the copper bellows 8 to isolate oxygen and flames. After that, the oxygen-isolating and fire-resistant layer 9 is isolated using a second cable tape 10, and then an inner sheath 11 is wrapped on the outer surface of the second cable tape 10. The outer surface of the inner sheath 11 is wrapped with an outer sheath 5. A carbon fiber tensile rope 12 for bearing the axial load of the cable is provided between the outer sheath 5 and the inner sheath 11. At the same time, the gap between the outer sheath 5, the inner sheath 11 and the carbon fiber tensile rope 12 is filled with a water-blocking layer 13 for blocking water.

[0024] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A fire-resistant mineral insulated cable, characterized in that: The invention comprises a support rib (1), wherein the cross section of the support rib (1) is in a "Y" shape, wherein each angle space of the support rib (1) is provided with a core conductor (2), wherein the outer surface of the core conductor (2) is coated with a single-layer semi-conductive tape (3), wherein the outer surface of the single-layer semi-conductive tape (3) is coated with an insulating layer (4), and the outer surface of the support rib (1) is wrapped with a first cable tape (6); The gaps between the first cable wrapping tape (6), the supporting ribs (1) and the core conductors (2) are filled with a fire barrier layer (7); The outer surface of the first cable tape (6) is coated with a copper bellows (8), the outer surface of the copper bellows (8) is coated with an oxygen-isolating and fire-resistant layer (9), the outer surface of the oxygen-isolating and fire-resistant layer (9) is coated with a second cable tape (10), the outer surface of the second cable tape (10) is coated with a water-blocking layer (13), and the outer surface of the water-blocking layer (13) is coated with an outer sheath (5); Six groups of carbon fiber tensile ropes (12) are arranged on the inner wall of the gap between the inner sheath (11) and the outer sheath (5), and the six groups of carbon fiber tensile ropes (12) are embedded inside the water-blocking layer (13).

2. A fire-resistant mineral insulated cable according to claim 1, characterized in that: The outer surface of the insulating layer (4) is in contact with the material of the fire barrier layer (7).

3. A fire-resistant mineral insulated cable according to claim 1, characterized in that: The fire barrier layer (7) is mainly composed of sodium bicarbonate.

4. A fire-resistant mineral insulated cable according to claim 1, characterized in that: The first cable wrapping tape (6) and the second cable wrapping tape (10) are both fire-resistant mica tapes.

5. A fire-resistant mineral insulated cable according to claim 1, characterized in that: The oxygen-isolating fire-resistant layer (9) is specifically a fire-proof mud layer made by mixing white jade powder and sodium silicate.

6. A fire-resistant mineral insulated cable according to claim 2, characterized in that: The material of the insulating layer (4) is ceramic polyolefin.

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