CN114594556A - Flame-retardant optical cable - Google Patents

Abstract

The invention discloses a flame-retardant optical cable, which sequentially comprises the following components in sequence from inside to outside: a reinforcement; the optical unit comprises a beam tube and an optical fiber penetrating through the beam tube; the heat insulation layer sequentially comprises an inner aerogel layer, a steel belt layer and an outer aerogel layer from inside to outside, and the inner aerogel layer wraps the outer side of the light unit; the pressure-resistant layer is arranged around the outer aerogel layer in a wave shape, and the inner side of a wave trough of the pressure-resistant layer is abutted against the outer aerogel layer; the restrictive coating is doped with the fire retardant, and the extrusion molding is in the anti-pressure layer outside, the inner wall of restrictive coating with the crest outside butt on anti-pressure layer. The flame-retardant optical cable can effectively isolate heat when an external fire occurs, ensures that the beam tube and the optical fiber are still at normal temperature, prolongs the normal communication time of the optical fiber, increases the rescue time and probability of trapped people, and has better pressure resistance.

Description

A flame retardant optical cable

technical field

The invention belongs to the field of optical cables, in particular to a flame retardant optical cable.

Background technique

With the development of communication technology, optical cable, as the basic material of communication, has been laid on a large scale all over the world. At present, the laid optical cables are mainly concentrated in conventional optical cables such as GYTS, GYTA and butterfly cables. With the diversification of the application environment, the functions and structures of optical cables have also developed into various types, such as rodent-proof optical cables, flame-retardant optical cables, etc.

When the optical cable is used in complex scenes with frequent accidents, such as underground, tunnels and mines, the requirements for the performance of the optical cable are higher. At this time, the optical cable not only needs to be resistant to compression, but also needs to be flame-retardant and fire-resistant. When accidents such as landslides and fires occur, the resistance to The better the pressure and flame retardant properties, the smoother the communication can be ensured and the more time left for rescue.

Existing mine-use flame-retardant optical cable (MGTSV-4B1 mine-use flame-retardant optical cable) is wound with a steel tape on the outside of the optical unit, and a single-layer or two-sided flame-retardant sheath is extruded on the outside of the steel tape. The compressive performance of the optical cable is good, but the flame retardant and fireproof performance is still weak. When the mine catches fire and the optical cable is surrounded by the external high temperature, the temperature of the steel belt is high, and the temperature is transmitted to the optical unit, causing damage to the bundle tube, resulting in the optical fiber. damaged.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention proposes a flame retardant optical cable, which solves the problem of insufficient flame retardant and fireproof performance of the existing mine optical cable, easy inward conduction of heat, and damage to the optical fiber, thus increasing the difficulty of rescue.

The technical scheme adopted by the present invention is as follows:

A flame retardant optical cable, which sequentially includes from the inside to the outside:

reinforcement;

an optical unit, including a bundle tube and an optical fiber passing through the bundle tube, a plurality of optical units are twisted or arranged in parallel around the reinforcing member;

The thermal insulation layer includes an inner aerogel layer, a steel strip layer and an outer aerogel layer sequentially from the inside to the outside, and the inner aerogel layer is wrapped around the outside of the light unit;

The compression layer is arranged around the outer aerogel layer in a wave shape, and the inner side of the wave valley of the compression layer is in contact with the outer aerogel layer;

The sheath layer, doped with a flame retardant, is extruded on the outside of the compression-resistant layer, and the inner wall of the sheath layer is in contact with the outer side of the wave crest of the compression-resistant layer.

Preferably, rubber balls are arranged between the pressure-resistant layer and the sheath, a cavity is arranged inside the rubber ball, and a flame retardant is arranged in the cavity. The outer side of the trough of the laminate is in contact with each other.

Preferably, the cavity is elliptical, and the line connecting the axis of the optical cable and the center of the cavity is perpendicular to the short axis of the cavity.

Preferably, a coating layer is provided on the outer side of the rubber ball, the inner diameter of the coating layer is equal to the outer diameter of the rubber ball, and openings are provided on both sides of the coating layer, and the outer wall corresponding to the short axis of the rubber ball cavity is the same as the outer diameter of the rubber ball. The openings are abutted, and the cladding layer is made of heat-shrinkable material.

Preferably, the cladding layer is tubular.

Preferably, the coating layer is spherical.

Preferably, the outer wall of the coating layer between the two rubber balls is provided with a cutout.

Preferably, heterogeneous flame retardant strips are arranged in the gaps between the compression-resistant layer and the heat insulation layer, the shapes of the heterogeneous flame retardant strips are adapted to the shapes of the gaps, and the interior of the heterogeneous flame retardant strips are provided with Through holes, the through holes are evenly and intermittently arranged in the axial direction of the optical cable.

Preferably, the materials of the inner aerogel layer and the outer aerogel layer are both silicon aerogels.

Preferably, the inner and outer sides of the compression layer are provided with a fireproof coating.

The beneficial effects of the invention are as follows: the optical cable is provided with a reinforcing piece, a steel belt and a compression layer to ensure the compression resistance of the optical cable; the sheath layer doped with a flame retardant is used as the primary flame retardant layer, and when the flame or heat reaches the When the optical cable diffuses inside, the rubber ball will burst to release the flame retardant, preventing the flame from conducting inward. When the fire is too large and further conducting inward, the through holes in the heterogeneous flame retardant strip are thermally expanded, and the heterogeneous flame retardant strip is full of compression resistance. The gap between the layer and the thermal insulation layer further prevents the flame from conducting inward; a double-layer aerogel is set as the thermal insulation layer, which can effectively prevent the inward diffusion of heat, avoid the influence of heat on the bundle tube and the optical fiber, and prolong the The communication time is increased, and the rescue time and probability of the trapped people are increased.

Description of drawings:

Fig. 1 is the structural representation of the optical cable of the present invention;

Fig. 2 is the structural representation of rubber ball in the optical cable of the present invention;

Fig. 3 is a kind of structural representation of the outer cladding layer of rubber ball in the optical cable of the present invention;

Fig. 4 is another kind of structural representation of the outer cladding layer of rubber ball in the optical cable of the present invention;

Fig. 5 is the structural representation of the heterogeneous flame-retardant strip in the optical cable of the present invention;

The reference numbers in the figure are:

Reinforcing member 1, light unit 2, heat insulation layer 3, compression layer 4, sheath layer 5, rubber ball 6, cladding layer 7, heterogeneous flame retardant strip 8, bundle tube 21, optical fiber 22, inner aerogel Layer 31 , steel strip layer 32 , outer aerogel layer 33 , cavity 61 , opening 71 , cutout 72 , through hole 81 .

Detailed ways:

The present invention will be further described and described in detail below with reference to specific embodiments and accompanying drawings. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention referred to in the following description are generally only some embodiments of the present invention, not all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "circumferential", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention. In the description of the present invention, the meaning of "plurality" is at least two, unless otherwise expressly and specifically defined, the meaning of "several" means one or more.

In the present invention, unless otherwise expressly specified and limited, terms such as "installation", "abutting", "connection", "fixing" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a fixed connection. Disassembled connection, or integrated; can be mechanical connection, can also be electrical connection or can communicate with each other; can be directly connected or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction of two elements relationship, unless otherwise expressly qualified. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

Unless otherwise specified, the raw materials used in the embodiments of the present invention are commercially available or available to those skilled in the art; and unless otherwise specified, the methods used in the embodiments of the present invention are the methods mastered by those skilled in the art.

Example

The present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1 , a flame-retardant optical cable includes, from inside to outside, a reinforcing member 1, an optical unit 2, a thermal insulation layer 3, a compression layer 4, and a sheath layer 5;

The reinforcement is arranged on the axis of the optical cable. As a supporting part of the optical cable as a whole, it can improve the compression resistance of the optical cable. Non-metallic materials are selected according to the requirements of optical cable performance;

The light unit includes a bundle tube 21 and an optical fiber 22 that passes through the bundle tube. A plurality of light units are twisted or arranged in parallel around the reinforcing member. In order to improve the water blocking performance of the optical fiber, the gap between the bundle tube and the optical fiber is Water-blocking powder is provided. Under normal circumstances, ointment and water-blocking yarn can be used as water-blocking materials for optical fibers, but ointment and water-blocking yarn are easier to burn than water-blocking powder, so the present invention selects water-blocking powder for filling;

The thermal insulation layer includes an inner aerogel layer 31, a steel strip layer 32 and an outer aerogel layer 33 in turn from the inside to the outside, and the inner aerogel layer is wrapped around the outside of the optical unit; the steel strip layer strengthens the optical cable The inner aerogel layer and the outer aerogel layer are respectively set inside and outside the steel belt layer. The inside of the aerogel is a mesh structure, and the medium filled is gas, which has the advantages of light weight, good heat insulation effect and good insulation. , high temperature resistance and other characteristics, aerogel is used as an important component of the thermal insulation layer, which can effectively isolate the heat without increasing the weight of the optical cable. In this embodiment, the inner aerogel layer and the outer aerogel layer The layers are all silicon aerogels, and the steel strips are embossed steel strips, and the rolled steel strips have better cladding performance.

The compression layer is arranged around the outer aerogel layer in a wave shape, the inner side of the trough of the compression layer is in contact with the outer aerogel layer, and the inner wall of the sheath layer is in contact with the outer side of the wave crest of the compression layer. The fire-resistant coating is provided on the inner and outer sides of the compression layer. In the present invention, the compression layer is made of metal foil, thermoplastic elastomer or plastic with good elasticity. In this embodiment, MDPE is selected.

The sheath layer, doped with a flame retardant, is extruded on the outside of the compression-resistant layer.

The strength members and steel tape make the optical cable have compression resistance. The sheath is the primary flame retardant layer, which is the first to resist the external fire. When the sheath is damaged and the fire or heat spreads into the optical cable, the inner and outer sides of the compression layer are set. There is a fireproof coating, so it is not easy to burn. In addition, due to the aerogel layer, the external heat is not easily conducted to the bundle tube, which ensures the normal operation of the optical fiber.

Further, rubber balls 6 are arranged between the compression layer and the sheath. The rubber balls are respectively abutted against the inner wall of the corresponding sheath and the valley of the compression layer. A cavity 61 is provided inside the rubber ball, and the cavity is A flame retardant is provided, and the structure of the rubber ball is shown in Figures 1 and 2. In addition, a coating layer 7 is provided on the outer side of the rubber ball. The inner diameter of the coating layer is equal to the outer diameter of the rubber ball. Openings 71 are provided on the left and right sides of the coating layer. The outer wall of the rubber ball is in contact with the opening. The cladding is heat shrinkable.

Specifically, the coating layer is tubular as shown in Figure 3 or spherical as shown in Figure 4. When the fire is large, the high temperature is conducted to the rubber ball and the compression layer through the sheath layer, and the rubber ball is thermally expanded and cracked Open, the internal flame retardant is sprayed through the openings on the left and right sides of the coating layer, slowing down the conduction and spread of temperature and fire to the interior of the optical cable. The coating layer is made of heat-shrinkable plastic, which will shrink sharply when heated, which will increase the internal stress of the rubber ball, and the inside of the rubber ball will expand when heated. . In addition, notches 72 can be provided between the rubber balls and on the outer wall of the covering layer, and the notches can help reduce the time for the covering layer to shrink under heat.

Further, the cavity is elliptical, and the connecting line between the optical cable axis and the cavity center is perpendicular to the short axis of the cavity, that is, the wall thickness where the rubber ball abuts against the opening of the cladding layer is the smallest, that is, This is where the flame retardant is most likely to be ejected when exposed to heat or when the coating is shrink-wrapped.

It should be noted that flame retardants should be understood in a broad sense, including fire extinguishing agents.

In addition, a heterogeneous flame retardant strip 8 is arranged in the gap between the compression layer and the heat insulation layer, and the shape of the heterogeneous flame retardant strip is adapted to the shape of the gap. The through holes are evenly and intermittently arranged in the axial direction of the optical cable, as shown in FIG. 5 . When the external fire is too large and the heat continues to be conducted to the inside of the optical cable through the compression layer, the through-hole is thermally expanded, which makes the volume of the heterogeneous flame-retardant strip become larger, filling the gap between the compression layer and the heat insulation layer, and further resisting the fire. Extend the normal communication time of optical fiber and gain valuable time for rescue communication.

The process of flame retardant and fire prevention of the optical cable of the present invention is as follows: when the outside is on fire, the sheath layer plays the initial flame retardant effect, if the fire is too large, the heat is conducted to the inside of the optical cable, the rubber ball is thermally expanded, and the superimposed coating layer shrinks, prompting The rubber ball bursts, and the flame retardant inside the rubber ball is sprayed out through the openings on both sides of the coating layer, and is distributed in the gap between the inner wall of the sheath and the compression layer. The function of preventing the spread of fire or extinguishing the fire. When the fire or temperature is difficult to control and conducts further inward, the through-hole is thermally expanded, which makes the volume of the heterogeneous flame-retardant strip become larger and fills the gap between the compression layer and the thermal insulation layer. Resist the fire. At this time, although the outside temperature is high, the two layers of aerogel layers are set in the optical cable, which can effectively isolate the heat, ensure that the bundle tube and the optical fiber are still at normal temperature, and prolong the normal communication of the optical fiber. increase the rescue time and probability of trapped persons.

Claims (10)

1. A flame-retardant optical cable, characterized in that, from the inside to the outside, it comprises: reinforcement; an optical unit, including a bundle tube and an optical fiber passing through the bundle tube, a plurality of optical units are twisted or arranged in parallel around the reinforcing member; The thermal insulation layer includes an inner aerogel layer, a steel strip layer and an outer aerogel layer sequentially from the inside to the outside, and the inner aerogel layer is wrapped around the outside of the light unit; The compression layer is arranged around the outer aerogel layer in a wave shape, and the inner side of the wave valley of the compression layer is in contact with the outer aerogel layer; The sheath layer, doped with a flame retardant, is extruded on the outside of the compression-resistant layer, and the inner wall of the sheath layer is in contact with the outer side of the wave crest of the compression-resistant layer. 2 . The flame-retardant optical cable according to claim 1 , wherein a rubber ball is arranged between the compression-resistant layer and the sheath, and a cavity is arranged inside the rubber ball, and a cavity is arranged in the cavity. 3 . There are flame retardants, and the rubber balls are respectively abutted against the inner wall of the corresponding sheath and the outer side of the trough of the compression layer. 3 . The flame-retardant optical cable according to claim 2 , wherein the cavity is elliptical, and the connecting line between the cable axis and the cavity center is perpendicular to the short axis of the cavity. 4 . 4 . The flame-retardant optical cable according to claim 3 , wherein a coating layer is provided on the outer side of the rubber ball, and the inner diameter of the coating layer is equal to the outer diameter of the rubber ball. There is an opening, the outer wall corresponding to the short axis of the rubber ball cavity is in contact with the opening, and the coating layer is made of heat-shrinkable material. 5 . The flame-retardant optical cable according to claim 4 , wherein the coating layer is tubular. 6 . 6 . The flame-retardant optical cable according to claim 4 , wherein the coating layer is spherical. 7 . 7 . The flame-retardant optical cable according to claim 4 , wherein the outer wall of the coating layer between the two rubber balls is provided with a cutout. 8 . 8 . The flame retardant optical cable according to claim 1 , wherein the space between the compression-resistant layer and the thermal insulation layer is provided with heterogeneous flame-retardant strips, and the heterogeneous flame-retardant The shape of the strip is adapted to the shape of the gap, and through holes are arranged inside the strips, and the through holes are evenly and intermittently arranged in the axial direction of the optical cable. 9 . The flame-retardant optical cable according to claim 1 , wherein the materials of the inner aerogel layer and the outer aerogel layer are both silicon aerogels. 10 . 10 . The flame-retardant optical cable according to claim 1 , wherein the inner and outer sides of the compression layer are provided with fire-resistant coatings. 11 .

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