Low-smoke halogen-free flame-retardant cable

Abstract

The utility model discloses a low-smoke halogen-free flame-retardant cable, which comprises a conductive sensing core, a filling rope, a flame-retardant wrapping tape and a sheath, the conductive sensing core comprises a sensing optical fiber and a plurality of conductors, the flame-retardant wrapping tape is wrapped outside the conductive sensing core, the filling rope is filled between the conductors and the flame-retardant wrapping tape, the sheath is made of ceramic silicone rubber and is extruded outside the flame-retardant wrapping tape, and the flame-retardant wrapping tape is wrapped outside the sensing optical fiber. The wall thickness of the lower side of the sheath is t1, and the wall thickness of the upper side of the sheath is t2, 1.5 lt; = t1 / t2lt; = 2. The utility model provides a low-smoke halogen-free flame-retardant cable, which can reduce sagging amount and lower side cracking.

Description

A low-smoke halogen-free flame-retardant cable Technical Field

[0001] This utility model relates to the field of flame-retardant cable technology, and in particular to a low-smoke halogen-free flame-retardant cable. Background Technology

[0002] Low-smoke halogen-free flame-retardant cables are widely used in construction, transportation, energy, and other fields, especially in locations with high fire safety requirements, such as high-rise buildings, hospitals, and schools. The cables produce less smoke when burning, improving visibility in fires and facilitating evacuation and rescue. Being halogen-free, they do not release toxic gases during combustion, reducing harm to human health.

[0003] Existing flame-retardant cables, as shown in patent application number CN202221636905.4, include a conductor, flame-retardant tape, and a sheath. Although such cables have the characteristics of being flame-retardant, low-smoke, and non-toxic, they sag significantly after ignition, and the lower side of the sheath is prone to cracking after sag, allowing flames to enter the cable, burn the conductor, and cause a power outage. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of existing flame-retardant cables, this utility model proposes a low-smoke halogen-free flame-retardant cable that reduces sag and lower side cracking.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A low-smoke halogen-free flame-retardant cable includes a conductive sensing core, a filler rope, a flame-retardant wrapping tape, and a sheath. The conductive sensing core includes a sensing optical fiber and multiple conductors. The flame-retardant wrapping tape is wrapped around the conductive sensing core. The filler rope is filled between the conductors and the flame-retardant wrapping tape. The sheath is made of ceramicized silicone rubber and is extruded over the flame-retardant wrapping tape. The lower wall thickness of the sheath is t1, and the upper wall thickness of the sheath is t2, where 1.5 <= t1 / t2 <= 2.

[0007] Through the above settings, firstly, the unequal wall thickness of the sheath, with the lower wall thickness increased, enhances the moment of inertia of the flame-retardant cable section and reduces sag; secondly, after ignition, the increased wall thickness on the lower side of the sheath can slow down the internal heat transfer and delay the softening and deformation of the cable; thirdly, after the sheath hardens, the lower side of the sheath forms stronger support, reducing sag and cracking on the lower side; and fourthly, the conductive sensing core has both conductivity and detection functions, facilitating the detection of cable vibration and temperature.

[0008] Furthermore, t2 < 3mm.

[0009] Furthermore, there are three conductors arranged in an inverted triangle, with the sensing fiber positioned between the two upper conductors.

[0010] The above settings prevent the sensing fiber from being pulled apart.

[0011] Furthermore, the sheath is filled with hollow glass microspheres.

[0012] By implementing the above settings, the sheath density is reduced, the weight of the flame-retardant cable is lightened, and the sag of the flame-retardant cable is further reduced.

[0013] Furthermore, markings are provided on the underside of the sheath.

[0014] The above settings facilitate the laying of flame-retardant cables.

[0015] Furthermore, the filling rope is an aramid fiber filling rope.

[0016] Aramid fiber filled rope is a low-smoke, halogen-free material with high tensile strength and will not release dense smoke or toxic gases when exposed to fire.

[0017] Furthermore, the sensing optical fiber includes an optical fiber filament and a copper tape armor wrapped around the outside of the optical fiber filament.

[0018] With the above setup, the copper tape armor protects the optical fiber strands, preventing them from breaking.

[0019] Furthermore, the flame-retardant wrapping tape is a low-smoke, halogen-free coated fabric tape wrapped around the conductive sensing core. Attached Figure Description

[0020] Figure 1 is a schematic diagram of a flame-retardant cable.

[0021] Figure 2 is an enlarged view of point A in Figure 1. Detailed Implementation

[0022] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0023] As shown in Figures 1 and 2, a low-smoke halogen-free flame-retardant cable includes a conductive sensing core, a filler rope 3, a flame-retardant wrapping tape 4, and a sheath 5. The conductive sensing core includes a sensing optical fiber 6 and multiple conductors 7. The flame-retardant wrapping tape 4 is wrapped around the conductive sensing core. The filler rope 3 is filled between the conductors 7 and the flame-retardant wrapping tape 4. The sheath 5 is made of ceramicized silicone rubber and is extruded over the flame-retardant wrapping tape 4. The lower wall thickness of the sheath 5 is t1, and the upper wall thickness of the sheath 5 is t2, where 1.5 <= t1 / t2 <= 2.

[0024] Through the above settings, firstly, the unequal wall thickness of the sheath 5, with the lower wall thickness increased, enhances the moment of inertia of the flame-retardant cable section and reduces sag; secondly, after ignition, the increased wall thickness on the lower side of the sheath 5 can slow down the internal heat transfer and delay the softening and deformation of the cable; thirdly, after the sheath 5 hardens, the lower side of the sheath 5 forms stronger support, reducing sag and cracking on the lower side; fourthly, the conductive sensing core has both conductivity and detection functions, facilitating the detection of cable vibration and temperature.

[0025] The conductive sensing core of this application consists of a conductor 7 and a sensing optical fiber 6. The conductor 7 is specifically a copper wire used for conduction, and a 110°C low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer is extruded on the outside of the copper wire. Under the reflection principle of DTS and DAS optical units, the sensing optical fiber 6 can detect the temperature and vibration at different locations of the cable, facilitating the detection of the cable fire location. The filler rope 3 increases the tensile strength of the flame-retardant cable and prevents the conductor 7 and sensing optical fiber 6 in the flame-retardant cable from breaking. The flame-retardant wrapping tape 4 adds an extra layer of fireproofing to prevent the flames from spreading inward after ignition. The sheath 5 is made of ceramicized silicone rubber, which hardens after exposure to fire, is not easily penetrated by flames, and has flame-retardant properties to prevent the flames from spreading inward and burning through the conductor 7 and sensing optical fiber 6. At the same time, the ceramicized silicone rubber does not contain halogens and does not produce toxic gases when exposed to fire. To reduce harm to the human body; the wall thickness of the sheath 5 gradually decreases from bottom to top, and the outer surface of the sheath 5 is basically circular. When the flame-retardant cable is laid horizontally in the air, the upper side of the sheath 5 is under pressure, while the lower side of the sheath 5 is under tension. Therefore, the upper side of the sheath 5 is not easy to crack. The wall thickness of the upper side of the sheath 5 can be thinner, while the wall thickness of the lower side needs to be thicker to prevent cracking. Specifically, the wall thickness t2 of the upper side of the sheath 5 is less than 3mm, and the wall thickness t2 of the upper side of the sheath 5 is 2mm. The wall thickness t1 of the lower side of the sheath 5 is 4mm. The thickening of the lower side of the sheath 5 slows down the speed of heat transfer inward after fire and slows down the softening and deformation speed of the flame-retardant cable. After the sheath 5 hardens, the lower side of the sheath 5 provides stronger support and reduces the amount of sagging. At the same time, due to the greater thickness, it prevents the lower side of the sheath 5 from cracking, thereby preventing the flames from spreading inward.

[0026] As one implementation method, three conductors 7 are arranged in an inverted triangle, and the sensing fiber 6 is placed between the two upper conductors 7.

[0027] The above settings prevent the sensing fiber 6 from being pulled apart.

[0028] The present application has three conductors 7, two of which are located on top and the remaining conductor 7 is located on the bottom, arranged in an inverted triangle. The sensing optical fiber 6 is located on the upper side between the two upper conductors 7. Specifically, the sensing optical fiber 6 is located above the center of the flame-retardant cable. When the flame-retardant cable hangs down, the sensing optical fiber 6 is not pulled, thus preventing the sensing optical fiber 6 from being pulled apart.

[0029] As one implementation method, the sheath 5 is filled with hollow glass microspheres.

[0030] By implementing the above settings, the density of the sheath 5 is reduced, the weight of the flame-retardant cable is reduced, and the sag of the flame-retardant cable is further reduced.

[0031] As one implementation method, a mark 8 is provided on the lower side of the sheath 5.

[0032] The above settings facilitate the laying of flame-retardant cables.

[0033] Mark 8 indicates the top and bottom sides of the flame-retardant cable. When laying the flame-retardant cable, mark 8 should be laid downwards.

[0034] As one implementation method, the filling rope 3 is an aramid fiber filling rope.

[0035] Aramid fiber filled rope is a low-smoke, halogen-free material with high tensile strength and will not release dense smoke or toxic gases when exposed to fire.

[0036] As one implementation, the sensing fiber 6 includes an optical fiber 61 and a copper tape armor 62 wrapped around the outside of the optical fiber 61.

[0037] With the above setup, the copper tape armor 62 protects the optical fiber filament 61 and prevents it from breaking.

[0038] As one implementation method, the flame-retardant wrapping tape 4 is a low-smoke halogen-free coated cloth tape, which is wrapped around the conductive sensing core.

[0039] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A low-smoke, halogen-free, flame-retardant cable, characterized in that, The device includes a conductive sensing core, a filler cord, a flame-retardant wrapping tape, and a sheath. The conductive sensing core includes a sensing optical fiber and multiple conductors. The flame-retardant wrapping tape is wrapped around the conductive sensing core. The filler cord is filled between the conductors and the flame-retardant wrapping tape. The sheath is made of ceramicized silicone rubber and is extruded over the flame-retardant wrapping tape. The lower wall thickness of the sheath is t1, and the upper wall thickness of the sheath is t2, where 1.5 <= t1 / t2 <= 2.

2. The low-smoke halogen-free flame-retardant cable according to claim 1, characterized in that, t2<3mm.

3. The low-smoke halogen-free flame-retardant cable according to claim 1, characterized in that, The conductor consists of three strands arranged in an inverted triangle, with the sensing optical fiber positioned between the two upper conductors.

4. The low-smoke halogen-free flame-retardant cable according to claim 1, characterized in that, The sheath is filled with hollow glass microspheres.

5. The low-smoke halogen-free flame-retardant cable according to claim 1, characterized in that, The lower side of the sheath is marked.

6. The low-smoke halogen-free flame-retardant cable according to claim 1, characterized in that, The filling rope is an aramid fiber filling rope.

7. The low-smoke halogen-free flame-retardant cable according to claim 1, characterized in that, The sensing optical fiber includes an optical fiber filament and a copper tape armor wrapped around the outside of the optical fiber filament.

8. The low-smoke halogen-free flame-retardant cable according to claim 1, characterized in that, The flame-retardant wrapping tape is a low-smoke, halogen-free coated fabric tape wrapped around the conductive sensing core.

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