Fireproof cable

Abstract

The utility model relates to a fire-resistant cable, which comprises a plurality of wire cores, each wire core comprises a conductor, and a mica tape fire-retardant layer, an insulating layer and a water-blocking layer which are sequentially coated on the outer side of the conductor, the plurality of wire cores are bundled and twisted and then tightened into a cable through a cabling tightening belt, and gaps formed between the plurality of wire cores and the cabling tightening belt are filled with an oxygen barrier layer. The outer side of the cabling tightening belt is sequentially coated with an anti-impact layer and a flame-retardant protection layer. The fireproof and waterproof performance and the impact resistance of the cable are effectively improved, and the reliability of the cable is improved.

Description

Technical Field

[0001] The present application relates to the field of cable technology, and in particular to a fire-resistant cable. Background Art

[0002] Fire-resistant cables can maintain the integrity of the circuit in the event of a fire, ensuring the safe and normal operation of key emergency systems. They are widely used in fire alarm systems, smoke detection systems, emergency lighting power systems and public broadcasting systems in large shopping malls, hospitals, office spaces, stations, airports, residential buildings and other buildings.

[0003] Fire-resistant cables are also widely used in nuclear power plants. The existing fire-resistant cables for nuclear power plants generally adopt the solution of wrapping the conductor with mica tape, which is difficult to pass the NS (fire supply + knocking + water spraying) fire resistance test specified in GB / T19666-2019. The test supply temperature is 830℃, the duration is 120min, the knocking is done every 5min, and the water is sprayed for the last 15min. Generally, fire-resistant cables will burn all organic matter in the flame, and all of them will be scattered during the knocking process, and finally the conductor will short-circuit during the water spraying process. Utility Model Content

[0004] In order to solve the problem in the prior art that organic matter in existing fire-resistant cables will fall off after burning and knocking, causing a short circuit when the conductor is exposed to water and sprayed, the present application provides a fire-resistant cable.

[0005] A fire-resistant cable provided in the present application adopts the following technical solution: a fire-resistant cable, comprising a plurality of cores, wherein the cores comprise a conductor and a mica tape fire-retardant layer, an insulating layer and a water-retaining layer sequentially coated on the outside of the conductor; the plurality of cores are bundled and fastened into a cable by a cabling tightening belt; an oxygen-isolating layer is filled in the gaps formed between the plurality of cores and the cabling tightening belt; and an impact-resistant layer and a flame-retardant protective layer are sequentially coated on the outside of the cabling tightening belt.

[0006] By adopting the above technical scheme, the flame retardant sheath plays the main role of radiation resistance, aging resistance and flame retardancy; the impact resistant layer is extruded outside the cabling tie to resist mechanical impact during the test and protect the inner insulation structure from being damaged; the cabling tightening belt plays the role of cabling tightening and auxiliary flame retardancy; the oxygen barrier layer is used to be burned first in the flame to protect the internal insulation structure; the water retaining layer plays the role of water retaining to prevent the conductor from short-circuiting due to contact with water; the insulating layer enables the cable to maintain insulation during its service life and can achieve flame retardancy of a single core; the mica tape fire barrier layer enables the cable to maintain insulation under flame conditions and maintain directional conduction of current; the conductor is used for current conduction.

[0007] Optionally, the conductor is a tinned copper conductor.

[0008] By adopting the above technical solution, the conductor material is tinned copper, which plays a role in current conduction in the innermost layer of the cable core.

[0009] Optionally, the mica tape fire barrier layer is made of calcined mica tape.

[0010] By adopting the above technical solution, the mica tape fire barrier layer material is a calcined mica tape, so that the cable can maintain the insulation effect under flame conditions and still maintain the directional conduction of current.

[0011] Optionally, the insulating layer is a cross-linked polyolefin insulating layer.

[0012] By adopting the above technical solution, the cross-linked polyolefin insulation layer material is a low-smoke halogen-free flame-retardant insulation radiation-treated material, so that the cable can maintain its insulation effect during its service life and at the same time achieve flame retardancy for a single core.

[0013] Optionally, the water retaining layer is made of a polyimide film.

[0014] By adopting the above technical solution, the water-retaining layer material is a polyimide film, which achieves a water-retaining effect and prevents the conductor from short-circuiting due to contact with water.

[0015] Optionally, the oxygen-isolating layer is made of a halogen-free, low-smoke oxygen-isolating layer crust-type material.

[0016] By adopting the above technical solution, the oxygen-insulating layer material is a halogen-free low-smoke oxygen-insulating layer crust type material, and the halogen-free low-smoke oxygen-insulating layer crust type material is prefabricated into a special shape of the core gap for shaping the cable gap, so that it is burned first in the flame to protect the internal insulation structure.

[0017] Optionally, the cabling fastening belt is a low-smoke halogen-free flame retardant belt.

[0018] By adopting the above technical solution, the cable tying belt material is a low-smoke halogen-free flame-retardant belt, which plays a role in cable tying and auxiliary flame retardancy.

[0019] Optionally, the impact-resistant layer is made of a halogen-free, low-smoke, oxygen-isolating layer crust-type material.

[0020] By adopting the above technical solution, the impact-resistant layer material is a halogen-free, low-smoke, oxygen-isolating layer crust type material, which is extruded outside the cable to resist mechanical impact and protect the inner insulation structure from damage.

[0021] Optionally, the flame retardant protective layer adopts a low-smoke halogen-free flame retardant sheath.

[0022] By adopting the above technical solution, the flame retardant sheath material is a low-smoke halogen-free flame retardant sheath material, which plays a major role in radiation resistance, anti-aging and flame retardancy in cables used in nuclear power plants.

[0023] Optionally, a plurality of the wire cores are arranged in a circular array.

[0024] In summary, the present application includes at least one of the following beneficial technical effects:

[0025] 1. In the present application, a water-retaining layer is coated on the outside of the core of the cable. The water-retaining layer is made of polyimide film. The polyimide film has outstanding high temperature resistance, radiation resistance, chemical corrosion resistance and electrical insulation performance. When the cable burns and water is sprayed to extinguish the fire, the water-retaining layer is resistant to high temperature and is not easily destroyed by the combustion. When water is sprayed, it can achieve a water-retaining effect to prevent the conductor from short-circuiting due to contact with water, effectively improving the fire resistance and waterproof performance of the cable and improving the reliability of the cable;

[0026] 2. An impact-resistant layer is provided in the cable of the present application. The material of the impact-resistant layer is a halogen-free, low-smoke, oxygen-insulating layer shell-type material, which is extruded outside the cable tie to resist mechanical impact and protect the inner insulation structure from being damaged, thereby improving the impact resistance of the cable and further improving the reliability of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the cross-sectional structure of a fire-resistant cable in an embodiment of the present application.

[0028] Explanation of the reference numerals: 1. conductor; 2. mica tape fire barrier layer; 3. insulation layer; 4. water retaining layer; 5. cabling tightening tape; 6. impact resistant layer; 7. oxygen barrier layer; 8. flame retardant sheath; 9. wire core. DETAILED DESCRIPTION

[0029] The following is an explanation of the implementation of the present application by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification.

[0030] See also Figure 1 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the restrictive conditions for the implementation of this application, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical content disclosed in this application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of this application. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of this application without substantially changing the technical content.

[0031] The following is combined with Figure 1 This application is described in further detail.

[0032] This embodiment discloses a fire-resistant cable.

[0033] Reference Figure 1 A fire-resistant cable comprises three cores 9 arranged in a circular array, the core 9 comprises a conductor 1 and a mica tape fire barrier layer 2, an insulating layer 3 and a water-blocking layer 4 sequentially coated on the outside of the conductor 1, the conductor 1 is a tinned copper conductor, the mica tape fire barrier layer 2 is a calcined mica tape, the insulating layer 3 is a cross-linked polyolefin insulating layer, the cross-linked polyolefin insulating layer material is a low-smoke halogen-free flame-retardant insulating radiation-treated material, the water-blocking layer 4 is a polyimide film, and the three cores After the 9 bundles are twisted, they are fastened into cables by means of a cabling tightening belt 5. The cabling tightening belt 5 is made of a low-smoke, halogen-free flame-retardant belt. The gap formed between the three wire cores 9 and the cabling tightening belt 5 is filled with an oxygen-isolating layer 7. The material of the oxygen-isolating layer 7 is a halogen-free, low-smoke, oxygen-isolating layer crust-type material. The outer side of the cabling tightening belt 5 is sequentially coated with an impact-resistant layer 6 and a flame-retardant sheath 8. The material of the impact-resistant layer 6 is a halogen-free, low-smoke, oxygen-isolating layer crust-type material. The material of the flame-retardant sheath 8 is a low-smoke, halogen-free flame-retardant sheath material.

[0034] The flame retardant sheath 8 plays a major role in radiation resistance, aging resistance and flame retardancy. The impact resistant layer 6 is extruded outside the cabling tightening belt 5 to resist mechanical impact during the test and protect the inner insulating structure from being damaged. The cabling tightening belt 5 plays a role in cabling tightening and auxiliary flame retardancy. The oxygen barrier layer 7 is used to be burned preferentially in the flame to protect the internal insulating structure. The water retaining layer 4 plays a role in water retaining to prevent short circuit caused by contact between the conductor and water. The insulating layer 3 enables the cable to maintain insulation during its service life and at the same time can achieve flame retardancy of a single core 9. The mica tape fire barrier layer 2 enables the cable to maintain insulation under flame conditions and maintain directional conduction of current. The conductor 1 is used for current conduction.

[0035] In summary, in the present application, a water-retaining layer is coated on the outside of the core of the middle wire, and the water-retaining layer is made of polyimide film. The polyimide film has outstanding high temperature resistance, radiation resistance, chemical corrosion resistance and electrical insulation performance. When the cable burns and water is sprayed to extinguish the fire, the water-retaining layer is resistant to high temperature and is not easily destroyed by burning. When spraying water, it can achieve a water-retaining effect to prevent the conductor from short-circuiting due to contact with water, effectively improving the fire resistance and waterproof performance of the cable, and improving the reliability of the cable; an impact-resistant layer is set in the cable of the present application, and the impact-resistant layer material is a halogen-free, low-smoke, oxygen-insulating layer crust-type material, which is extruded outside the cable to resist mechanical impact, protect the inner insulation structure from being damaged, improve the impact resistance of the cable, and further improve the reliability of the cable. Therefore, the present application effectively overcomes the various shortcomings in the prior art and has a high industrial utilization value.

[0036] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present application shall still be included in the protection scope of the present application.

Claims

1. A fire-resistant cable, characterized in that: The invention comprises a plurality of wire cores (9), wherein the wire cores (9) comprise a conductor (1) and a mica tape fire barrier layer (2), an insulating layer (3) and a water-retaining layer (4) which are sequentially coated on the outside of the conductor (1); the water-retaining layer (4) is made of a polyimide film to prevent the conductor from short-circuiting due to contact with water; the plurality of wire cores (9) are bundled and fastened into a cable by a cable fastening belt (5); an oxygen-isolating layer (7) is filled in the gaps formed between the plurality of wire cores (9) and the cable fastening belt (5); and the outside of the cable fastening belt (5) is sequentially coated with an impact-resistant layer (6) and a flame-retardant protective layer (8).

2. A fire-resistant cable according to claim 1, characterized in that: The conductor (1) is a tinned copper conductor.

3. A fire-resistant cable according to claim 1, characterized in that: The mica tape fire barrier layer (2) is made of calcined mica tape.

4. A fire-resistant cable according to claim 1, characterized in that: The insulating layer (3) is a cross-linked polyolefin insulating layer.

5. A fire-resistant cable according to claim 1, characterized in that: The oxygen-isolating layer (7) is made of a halogen-free, low-smoke oxygen-isolating layer crust-type material.

6. A fire-resistant cable according to claim 1, characterized in that: The cabling fastening belt (5) is a low-smoke, halogen-free flame-retardant belt.

7. A fire-resistant cable according to claim 1, characterized in that: The impact-resistant layer (6) is made of a halogen-free, low-smoke, oxygen-isolating layer crust-type material.

8. A fire-resistant cable according to claim 1, characterized in that: The flame retardant protective layer (8) adopts a low-smoke halogen-free flame retardant sheath.

9. A fire-resistant cable according to claim 1, characterized in that: A plurality of the wire cores (9) are arranged in a circular array.

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