阅读说明：本技术 一种阻燃b1级电缆 (Flame-retardant B1-grade cable ) 是由 莫川邻 李志现 刘春昉 刘永红 刘新峰 陈龙 刘兴龙 白飞正 于 2019-09-23 设计创作，主要内容包括：本发明公开了一种阻燃B1级电缆,所述电缆具有主要由多根绝缘导体组成的缆芯,所述缆芯上由内而外依次包覆有内陶瓷化纤维带层、隔氧层、外陶瓷化纤维带层和护套层,且所述内陶瓷化纤维带层所包覆的所述缆芯的组合间隙内填充有陶瓷化纤维棉填充层。本发明通过此种结构排布使得对缆芯的绝缘导体形成了多层防护,以阻止火焰向缆芯内部的燃烧,同时能够最大程度的阻止外部热量向缆芯的绝缘导体上传导,具有防火隔火性能好、阻燃效果优异的特点。(The invention discloses a flame-retardant B1-grade cable, which is provided with a cable core mainly composed of a plurality of insulated conductors, wherein an inner ceramic fiber belt layer, an oxygen isolation layer, an outer ceramic fiber belt layer and a sheath layer are sequentially coated on the cable core from inside to outside, and a ceramic fiber cotton filling layer is filled in a combined gap of the cable core coated by the inner ceramic fiber belt layer. According to the invention, through the structural arrangement, the insulating conductor of the cable core is protected in a multi-layer manner, so that the flame is prevented from burning towards the inside of the cable core, and meanwhile, the external heat can be prevented from being conducted onto the insulating conductor of the cable core to the greatest extent, and the cable core has the characteristics of good fire prevention and insulation performance and excellent flame retardant effect.)

1. A flame retardant class B1 cable having a core consisting essentially of a plurality of insulated conductors, wherein: the cable core is sequentially coated with an inner ceramic fiber belt layer (4), an oxygen separation layer (6), an outer ceramic fiber belt layer (8) and a sheath layer (9) from inside to outside, and a combined gap of the cable core coated by the inner ceramic fiber belt layer (4) is filled with a ceramic fiber cotton filling layer (3).

2. The flame retardant B1 grade cable of claim 1, wherein: and a mirror surface metal composite belt layer (5) is coated between the inner ceramic fiber belt layer (4) and the oxygen isolation layer (6).

3. The flame retardant B1 grade cable of claim 2, wherein: the mirror surface metal composite belt layer (5) is of at least one layer of lapping structure of a mirror surface aluminum-plastic composite belt.

4. The flame retardant B1 grade cable of claim 1 or 2, wherein: the inner ceramic fiber belt layer (4) is of at least one layer of wrapping structure of the ceramic fiber belt.

5. The flame retardant B1 grade cable of claim 1, wherein: a cooling layer (7) is coated between the oxygen insulation layer (6) and the outer ceramic fiber tape layer (8), and the cooling layer (7) is a molding structure with a hollow cavity filled with aluminum hydroxide or magnesium hydroxide filler.

6. The flame retardant B1 grade cable of claim 5, wherein: the cooling layer (7) is composed of a plurality of hollow pipes (71) which are arranged in the circumferential direction and a filler (72) filled in each hollow pipe (71).

7. The flame retardant B1 grade cable of claim 1, 2 or 5, wherein: the oxygen isolation layer (6) is of a low-smoke halogen-free polyolefin extrusion layer structure.

8. The flame retardant B1 grade cable of claim 1 or 5, wherein: the outer ceramic fiber belt layer (8) is at least one layer of wrapping structure of the ceramic fiber belt.

9. The flame retardant B1 grade cable of claim 1, wherein: the sheath layer (9) is of a low-smoke halogen-free flame-retardant polyolefin extrusion layer structure.

10. The flame retardant B1 grade cable of claim 1, wherein: a plurality of insulated conductors of the cable core are twisted together, and a ceramic fiber cotton filling layer (3) is filled in a twisting gap; each insulated conductor of the cable core mainly comprises a conductor (1) and an insulating layer (2) coated on the conductor (1), wherein the conductor (1) is a 1 st copper conductor, a 2 nd copper conductor or a 5 th soft copper conductor in the standard GB/T3956, and the insulating layer (2) is an extruded layer structure of irradiation type cross-linked polyolefin; the conductor (1) is of a single-strand copper wire structure or a multi-strand copper wire stranded structure.

Technical Field

The invention relates to a power cable, in particular to a power cable capable of passing a flame-retardant B1-grade test.

Background

The cable is classified into a general cable, a flame retardant cable, and a fire resistant cable according to its own combustion characteristics. The flame-retardant cable can be divided into A, B, C, D four flame-retardant grades according to the classification of the combustion performance, the common flame-retardant cable is manufactured and molded according to the technical standard of GB/T19666-2005 flame-retardant and fire-resistant cable general rules, and the flame-retardant cable is widely applied to national economic construction.

However, in the burning process of fire, the flame temperature usually reaches about 750 ℃, even about 950 ℃, the temperature resistant grade of the glass fiber filling layer and the glass fiber tape layer of the flame retardant cable cannot adapt to the burning temperature, the flame retardant cable is very easy to burn, and the burned residues are very fragile, can easily fall off after being slightly touched or vibrated, cannot effectively prevent the flame or temperature from burning and transmitting to the inside, cannot protect the insulating layer with poor flame retardant property of the inner layer, and thus cause the burning of the insulating layer material (because the insulating material is mostly organic matter which is easy to burn), finally causes the continuous burning of the whole cable, releases a large amount of heat and smoke, and cannot guarantee the fire safety.

Along with the rapid and steady development of national subway key projects, particularly, people in subway stations are dense and congested, once a fire sign appears, the loss of national property is caused, and more seriously, the life safety of a plurality of people is threatened. Therefore, the state publishes the technical standard of mandatory national standard GB 31247-2014 'Classification of burning performance of electric cables and optical cables' in 12-5 th month in 2014, and in the technical standard, by quantizing the technical indexes of the Classification of the burning performance of the electric cables and the optical cables, the fire prevention safety is more scientific and reasonable, and the possible fire hazard is reduced to the lowest.

Obviously, the conventional flame-retardant cable is difficult to meet the increasingly stringent and more scientific and reasonable technical standard regulations, cannot meet the development requirements of the market and the technology, and needs to be improved.

Disclosure of Invention

The technical purpose of the invention is as follows: aiming at the defects of the prior art, the flame-retardant B1-grade cable with good fireproof and fire-proof performance and excellent flame-retardant effect is provided.

The technical purpose of the invention is realized by the following technical scheme: a flame-retardant B1-grade cable is provided with a cable core mainly composed of a plurality of insulated conductors, wherein an inner ceramic fiber belt layer, an oxygen isolation layer, an outer ceramic fiber belt layer and a sheath layer are sequentially coated on the cable core from inside to outside, and a ceramic fiber cotton filling layer is filled in a combined gap of the cable core coated by the inner ceramic fiber belt layer.

Preferably, a mirror-surface metal composite tape layer is coated between the inner ceramic fiber tape layer and the oxygen barrier layer. Furthermore, the mirror surface metal composite belt layer is of at least one layer of lapping structure of a mirror surface aluminum-plastic composite belt.

Preferably, the inner ceramic fiber tape layer is at least one layer of wrapping structure of ceramic fiber tapes.

As one preferable scheme, a cooling layer is coated between the oxygen-insulating layer and the outer ceramic fiber tape layer, and the cooling layer is a molding structure in which a hollow cavity is filled with aluminum hydroxide or magnesium hydroxide filler. Furthermore, the cooling layer is composed of a plurality of hollow pipes which are circumferentially arranged and a filler which is filled in each hollow pipe.

As one preferable scheme, the oxygen isolation layer is an extruded layer structure of low-smoke halogen-free polyolefin.

Preferably, the outer ceramic fiber belt layer is at least one layer of wrapping structure of the ceramic fiber belt.

As one preferable scheme, the sheath layer is an extruded layer structure of low-smoke halogen-free flame-retardant polyolefin.

As one preferred scheme, a plurality of insulated conductors of the cable core are twisted together, and a ceramic fiber cotton filling layer is filled in a twisting gap. Furthermore, each insulated conductor of the cable core mainly comprises a conductor and an insulating layer coated on the conductor, wherein the conductor is a 1 st copper conductor, a 2 nd copper conductor or a 5 th soft copper conductor in the standard GB/T3956, and the insulating layer is an extruded layer structure of irradiation type cross-linked polyolefin. Still further, the conductor of the insulated conductor is in a single-stranded copper wire structure or a multi-stranded copper wire twisted structure.

The beneficial technical effects of the invention are as follows:

1. The ceramic fiber material adopted by the invention is an aluminum silicate refractory fiber, which is prepared by melting hard clay clinker or industrial alumina powder and silica powder synthetic material serving as raw materials in an electric arc furnace or a resistance furnace and forming fibers by blowing compressed air (or a wire throwing method), wherein the chemical components mainly comprise aluminum oxide (30-55%) and silicon dioxide, and the ceramic fiber material is reprocessed and formed, has the characteristics of low thermal capacity, low thermal conductivity, excellent thermal stability and high temperature resistance of over 1000 ℃, and cannot be combusted; the material is filled in the combined gap of the cable core, the inner ceramic fiber band layer, the oxygen barrier layer, the outer ceramic fiber band layer and the like are reasonably arranged outside the cable core, and the insulating conductor of the cable core forms multi-layer protection through the structural arrangement so as to prevent flame from burning towards the inside of the cable core and prevent external heat from being conducted towards the insulating conductor of the cable core to the maximum extent;

2. The mirror surface metal composite belt layer coated between the internal ceramic fiber belt layer and the oxygen isolation layer can reflect most of heat, so that the temperature influence of external heat on an internal structural member is reduced, and the conduction of external heat to an insulated conductor of a cable core is further effectively prevented, which is particularly obvious in the structure that the mirror surface metal composite belt layer adopts the mirror surface aluminum-plastic composite belt wrapping, and the reflection effect of the surface of the mirror surface aluminum-plastic composite belt as a heat reflection layer is excellent;

3. the cooling layer coated between the oxygen-isolating layer and the outer ceramic fiber band layer can decompose aluminum hydroxide or magnesium hydroxide as filler into aluminum oxide/magnesium oxide and water (H) in the cable combustion process₂O), the flame temperature is effectively reduced through the existence of moisture, the combustion of the flame is prevented, and the fireproof and flame-retardant effects of the flame are further effectively improved;

4. The hollow pipe arrangement structure of the cooling layer can realize compact and compact arrangement, and has high strength and good integrity.

Drawings

Fig. 1 is a schematic structural diagram of the present invention, and it can be seen that a cable core mainly comprises four insulated conductors, each of which mainly comprises a conductor and an insulating layer coated on the conductor; an inner ceramic fiber belt layer, a mirror surface metal composite belt layer, an oxygen barrier layer, an outer ceramic fiber belt layer and a sheath layer are sequentially coated on the cable core from inside to outside; a ceramic fiber cotton filling layer is filled in the combined gap of the cable core coated by the inner ceramic fiber belt layer.

FIG. 2 is another schematic structural diagram of the present invention, and it can be seen that a cable core is mainly composed of four insulated conductors, each of which is mainly composed of a conductor and an insulating layer coated on the conductor; an inner ceramic fiber belt layer, a mirror surface metal composite belt layer, an oxygen barrier layer, a cooling layer, an outer ceramic fiber belt layer and a sheath layer are sequentially coated on the cable core from inside to outside; a ceramic fiber cotton filling layer is filled in a combined gap of the cable core coated by the inner ceramic fiber belt layer; the cooling layer is composed of a plurality of pipe-shaped structures with fillers which are circumferentially arranged.

Fig. 3 is an enlarged schematic view of the cooling layer in fig. 2, and it can be seen that the units constituting the cooling layer are hollow tubes and fillers filled in the hollow tubes.

The reference numbers in the figures mean: 1-a conductor; 2-an insulating layer; 3-a ceramic fiber cotton filling layer; 4-internal ceramic fiber belt layer; 5-mirror surface metal composite belt layer; 6-oxygen barrier layer; 7-cooling layer; 71-a hollow tube; 72-a filler; 8-outer ceramic fiber tape layer; 9-sheath layer.

Detailed Description

The invention relates to a power cable, in particular to a power cable capable of passing a flame-retardant B1 grade test, and the main technical content of the invention is explained in detail by a plurality of embodiments. In embodiment 1, the technical contents of the present invention are clearly and specifically explained with reference to the drawings of the specification, i.e., fig. 1, in embodiment 5, the technical contents of the present invention are clearly and specifically explained with reference to the drawings of the specification, i.e., fig. 2 and fig. 3, in other embodiments, although the drawings are not separately drawn, the main structures of the embodiments can still refer to the drawings of embodiment 1.

It is expressly noted here that the drawings of the present invention are schematic and have been simplified in unnecessary detail for the purpose of clarity and to avoid obscuring the technical solutions that the present invention contributes to the prior art.