Combustion-resistant fireproof coaxial cable
Through multi-layer structure and inorganic flame retardant design, the problem of easy combustion and toxic gas release of coaxial cables in fire scenarios is solved, achieving efficient flame retardancy and safe transmission, suitable for modern buildings and data centers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HANGZHOU PUTIANLE CABLE CO LTD
- Filing Date
- 2026-01-23
- Publication Date
- 2026-05-01
AI Technical Summary
Existing coaxial cables are easily combustible in fire scenarios, producing toxic gases and black smoke, and are difficult to clean up and restore to the environment, thus failing to meet safety protection requirements.
It adopts a multi-layer structure design, including an insulation layer, fireproof partition, conductor, tensile steel cable, flame retardant layer and outer sheath. It utilizes inorganic flame retardants and high-temperature ceramic design, combined with multi-layer protection measures, to block the spread of flames and the release of toxic gases.
It effectively blocks the spread of flames, reduces the generation of toxic gases and black smoke, improves the flame retardancy rating, reduces environmental cleanup costs, and ensures the safe and reliable transmission of cables in fire environments.
Smart Images
Figure CN121964258A_ABST
Abstract
Description
A fire-resistant coaxial cable Technical Field
[0001] This application relates to the technical field of coaxial cables, and in particular to a fire-resistant coaxial cable. Background Technology
[0002] In modern building and electronic equipment cabling systems, coaxial cables have become a key medium for radio frequency signals, video signals, and high-speed data transmission due to their core advantages of low signal transmission loss, strong anti-interference ability, and excellent shielding performance. Their serial and fundamental characteristics in cabling systems mean that if a coaxial cable encounters a safety problem in an emergency such as a fire, it will directly affect the normal operation of the entire building or equipment system, and may even trigger a chain of safety accidents.
[0003] The insulation and sheath layers of ordinary coaxial cables are mostly made of basic polymer materials such as polyvinyl chloride and polyethylene, without special flame-retardant modification treatment, or with only a small amount of flame retardant added. This results in flame-retardant performance far below safety standards, leading to rapid combustion under open flame and fast flame spread. The raw materials of ordinary coaxial cables contain halogen elements such as chlorine and bromine, which undergo violent thermal decomposition reactions during combustion, releasing toxic gases such as hydrogen halides, carbon monoxide, and cyanides, while also producing large amounts of dense black smoke. In response to the aforementioned issues, the inventors discovered that the raw materials for the insulation and sheath layers of ordinary coaxial cables are inherently flammable or combustible. Even with the addition of small amounts of flame retardants in some products, only a preliminary effect of delaying combustion can be achieved, which cannot meet the safety protection requirements in fire scenarios. The toxic gases, black smoke particles, and molten residue produced when ordinary coaxial cables burn not only cause immediate harm at the fire scene but also cause long-term pollution to the surrounding environment, with subsequent cleanup and environmental restoration work being extremely difficult. Summary of the Invention
[0004] In order to overcome the fact that the insulation and sheath layers of existing ordinary coaxial cables are made of flammable or combustible materials, even if some products add a small amount of flame retardant, it can only achieve a preliminary effect of delaying combustion and cannot meet the safety protection requirements in fire scenarios. The toxic gases, black smoke particles and molten residues produced when ordinary coaxial cables burn not only cause immediate harm at the fire scene, but also cause long-term pollution to the surrounding environment, and the subsequent cleanup and environmental restoration work is extremely difficult. Therefore, this application provides a fire-resistant coaxial cable.
[0005] The fire-resistant coaxial cable provided in this application adopts the following technical solution:
[0006] A fire-resistant coaxial cable includes a cable body and an outer sheath. The cable body includes an insulation layer, fire-resistant partitions, conductors, tensile steel cables, a flame-retardant layer, and an outer sheath. Multiple fire-resistant partitions are spaced apart inside the insulation layer along the axial direction of the cable body. Multiple conductors and tensile steel cables are disposed inside the insulation layer, and the multiple conductors and tensile steel cables are dispersedly disposed through the multiple fire-resistant partitions. A flame-retardant layer is sleeved outside the insulation layer, and an outer sheath is sleeved outside the flame-retardant layer. The outer sheath is sleeved and assembled on the outer wall of the outer sheath of the cable body.
[0007] By employing the above technical solutions, the insulation layer is responsible for isolating the conductor from electrical contact with the outside world, ensuring safe circuit transmission, and effectively preventing electromagnetic interference. The fire-resistant separator acts like a firewall, separating the conductors to prevent the spread of fire during a fire, thereby reducing the risk of cable fire. The conductor provides the electrical conductivity of the circuit, ensuring smooth current transmission. The tensile steel cable provides additional support to the cable, enhancing its overall mechanical strength and enabling it to withstand certain tensile and bending forces. The flame-retardant layer can retard flames when the cable encounters a fire source, effectively delaying the spread of fire and protecting the internal structure of the cable from being burned. The outer sheath provides external protection, enhancing the cable's abrasion resistance and tensile strength. Furthermore, the outer sheath provides further mechanical protection, ensuring the cable can function normally in various complex environments. In summary, these components work together to ensure the cable's safe and reliable transmission function in harsh environments such as fires. Under normal circumstances, the insulation layer and conductor complete the task of transmitting electrical energy, while the fire-resistant separator and tensile steel cable protect the cable from physical and safety hazards. In the event of a fire, the flame-retardant layer slows the spread of the fire, while the outer sheath and outer layer ensure that the cable structure is not damaged, thereby guaranteeing the safety of communication or power transmission.
[0008] Optionally, the insulating layer includes an insulating sleeve and a connecting sleeve. The insulating sleeve is made of polyolefin resin material, and the connecting sleeve is fitted on the outer wall of the insulating sleeve. The connecting sleeve is made of boron nitride-filled silicone material.
[0009] By adopting the above technical solution, the insulating sleeve is made of polyolefin resin material, which can effectively prevent the insulation of the cable from failing or being damaged due to external factors in harsh environments, and provide long-term stable electrical insulation performance. The connecting sleeve is made of boron nitride-filled silicone material, which not only has good elasticity and flexibility, but also can be prevented from falling off due to aging or wear when the cable is subjected to external forces, temperature changes, etc., thereby reducing direct damage to the cable.
[0010] Optionally, the insulating sleeve has multiple heat-conducting tubes integrally formed inside, and multiple heat-conducting fins are evenly arranged on the outer wall of the multiple heat-conducting tubes. The multiple heat-conducting fins are integrally cast with the outer wall of the multiple heat-conducting tubes, and the interior of the heat-conducting tubes is filled with cable filler paste.
[0011] By adopting the above technical solution, the cable filler paste inside the heat pipe can effectively reduce the temperature of the cable during operation. Meanwhile, the design of the heat-conducting fins further enhances heat conduction efficiency, helping to quickly dissipate heat from within the cable and ensuring that the cable can still operate safely and reliably in high-temperature environments. Overall, this structure not only improves the electrical safety and mechanical protection of the cable but also effectively enhances its heat dissipation performance, thereby extending the cable's service life and strengthening the overall stability and reliability of the system.
[0012] Optionally, the fireproof partition includes a plastic support plate with multiple horizontal through holes for inserting and supporting conductors. A tension hole is formed at the center of the plastic support plate, and a support ring is fixed in the middle of the inner wall of the tension hole for clamping and assembling tension steel cables.
[0013] By adopting the above technical solution, the plastic support plate of the fireproof partition is mainly used to support and guide the conductor. Multiple horizontally opened wire holes are used to insert and support the conductor, ensuring that the conductor can be reliably fixed in place during a fire. The tension holes provide additional tension support points, and the support rings within them are used to fix the tension steel cable, enhancing the overall structural stability.
[0014] Optionally, the plastic support plate has a filler cavity inside, and the filler cavity of the plastic support plate is filled with flame-retardant filler, which is made of compressed expandable graphite material.
[0015] By adopting the above technical solution, the hollow cavity inside the plastic support plate is filled with expandable graphite material as a flame-retardant filler. This material expands to form an isolation layer during a fire, effectively preventing the spread of flames. This fireproof partition not only provides stable support for the conductor, ensuring the safety of the transmission line, but also provides effective fireproof isolation in case of fire through the internal flame-retardant filler, enhancing the overall fire resistance and thus protecting the conductor and reducing the risk of flame spread.
[0016] Optionally, the flame-retardant layer includes a woven mesh tube, a flame-retardant film, a fiberglass cloth tube, and a steel mesh tube. The inner wall of the woven mesh tube is provided with a flame-retardant film, and the inner wall of the flame-retardant film is provided with a fiberglass cloth tube. The inner wall of the fiberglass cloth tube is fixed with a steel mesh tube.
[0017] By employing the above technical solution, the flame-retardant layer is composed of multiple components, each playing a unique role. The flame-retardant film, made of ceramicized silicone rubber, not only possesses excellent high-temperature resistance but also forms a protective film upon flame contact, further preventing the spread of flames. The fiberglass cloth tube provides additional mechanical protection and heat resistance, while the steel mesh tube further enhances the overall structural strength, making the entire flame-retardant layer more robust and durable. When an external fire source approaches, the inner nylon braided layer and flame-retardant filler will act first, blocking and slowing the spread of flames. The fiberglass cloth tube and steel mesh tube provide additional protection, ensuring the stability and durability of the overall structure, together achieving a highly efficient flame-retardant effect.
[0018] Optionally, the braided wire of the braided mesh tube is composed of a nylon braided layer and flame-retardant filler. The nylon braided layer has a hollow cavity inside, and the hollow cavity of the nylon braided layer is filled with flame-retardant filler. The flame-retardant filler is made of aluminum hydroxide material, and the flame-retardant film is a ceramicized silicone rubber film.
[0019] By adopting the above technical solution, the nylon braided layer inside the woven mesh cylinder provides a certain strength and toughness, while the flame-retardant filler inside effectively improves the overall fire resistance. The flame-retardant filler made of aluminum hydroxide can decompose and absorb heat at high temperatures, helping to slow down the combustion process. Subsequently, the flame-retardant film transforms into a ceramic-like protective film at high temperatures, forming a barrier that prevents the flame from spreading further.
[0020] Optionally, the outer protective layer includes a corrugated pipe made of galvanized steel sheet, with an insulating film adhered to the inner wall of the corrugated pipe, and the outside of the corrugated pipe is wrapped with ceramic silicone cloth.
[0021] By adopting the above technical solutions, the corrugated pipe in the outer protective layer is made of galvanized material, which effectively improves its corrosion resistance and mechanical strength, ensuring stable operation of the pipe body in harsh environments. The ceramic silicone cloth on the outer layer of the corrugated pipe not only provides additional protection but also enhances insulation performance and prevents electromagnetic interference. In summary, this system effectively supports and protects the pipe, reduces heat conduction through the heat insulation film, enhances protective insulation through the ceramic silicone cloth, and provides double insulation through mica powder, all of which together ensure the stability and reliability of the system, making it suitable for demanding industrial environments.
[0022] Optionally, the heat insulation film is made of aluminum foil, and mica powder is filled between the ceramic silicone cloth and the corrugated pipe.
[0023] By adopting the above technical solution, the heat insulation film inside the corrugated pipe is made of aluminum foil, which can effectively reduce heat conduction, reduce the impact of external heat on the internal medium, and maintain the temperature stability of the medium. Mica powder is filled between the ceramic silicone cloth and the corrugated pipe, which further enhances the heat insulation effect and improves the sealing and heat resistance of the structure.
[0024] Optionally, the outer layer includes a mesh sleeve made of nylon, and the outer wall of the mesh sleeve is provided with multiple filler bags, each of which is filled with flame-retardant powder.
[0025] By adopting the above technical solution, the outer layer consists of a mesh sleeve and filler bags. The mesh sleeve is made of nylon, providing good air permeability and abrasion resistance, suitable for wrapping other components. Each filler bag is filled with flame-retardant powder, which can effectively block the spread of flames in the event of a fire, thereby protecting the internal structure. The mesh sleeve, through its mesh structure, fixes multiple filler bags in appropriate positions, ensuring that the filler bags are evenly distributed and achieve optimal flame-retardant effect. In summary, this design provides physical support and air permeability through the mesh sleeve, while the flame-retardant powder inside the filler bags plays a crucial role in flame retardancy during a fire, together ensuring the safety performance of the overall system.
[0026] In summary, this application includes at least one of the following beneficial technical effects:
[0027] 1. Through a five-layer protection design consisting of an outer layer, outer sheath, flame-retardant layer, insulation layer, and fireproof partition, the cable achieves full-process protection including open flame suppression, heat insulation, and flame sealing, fully meeting safety requirements in fire scenarios. The magnesium hydroxide flame-retardant powder in the outer layer decomposes rapidly when heated, absorbing a large amount of heat and releasing water vapor, which can extinguish the flame in a short time when the open flame comes into contact with the cable, preventing the flame from spreading along the cable surface. The aluminum hydroxide flame-retardant filler in the flame-retardant layer decomposes when heated, further replenishing water vapor and forming a double water vapor barrier. Even if the outer layer protection fails, it can still continuously suppress the open flame, shortening the burning length of the cable under open flame. The multi-layered structure blocks heat transfer, ensuring zero damage to core transmission components. The galvanized steel corrugated pipe outer sheath can withstand direct burning by high-temperature open flames. Combined with the inner aluminum foil heat insulation film, it increases the reflectivity of radiant heat, reducing the temperature inside the outer sheath. Ceramic silicone cloth further blocks heat penetration, forming a triple heat insulation barrier of metal, reflectivity, and high-temperature resistant fabric. The heat-conducting pipes in the insulation layer, in conjunction with the cable filler grease, can quickly absorb the heat from the insulating sleeve, ensuring uninterrupted signal transmission and completely solving the problem of heat penetration leading to damage to core components in traditional cables. The expandable graphite in the fireproof separator expands rapidly at high temperatures, forming a fluffy carbon layer that not only fills the annular space inside the cable but also extends to both sides, sealing the cavities between adjacent separators. Traditional cables lack cavity sealing designs, allowing flames to easily spread through the internal cavities. This technology completely blocks this spread path, confining the fire to a single separator section and preventing large-scale fires. The expandable graphite seals the flame path, preventing flame spread.
[0028] 2. By replacing halogen-based materials with inorganic flame retardants and using high-temperature ceramic design, the generation of toxic substances is reduced from the source, significantly improving the survival probability of people in fire scenarios. Inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide are used, resulting in low release of hydrogen halide gas and carbon monoxide during combustion. No black smoke is produced when inorganic flame retardants burn. The ceramicized silicone rubber film is transformed into a ceramic shell at high temperature, avoiding secondary combustion and black smoke particle generation caused by molten drippings from traditional cables.
[0029] 3. This technology solves the core problems of traditional coaxial cables, such as weak flame retardancy, high toxicity, and high pollution, through innovative solutions including multi-level synergistic flame retardancy, low toxicity and low smoke design, and environmentally friendly residue control. It not only improves the flame retardancy level and reduces the release of toxic substances, but also significantly reduces environmental cleanup costs. At the same time, it takes into account mechanical performance and signal transmission stability, providing a safe, environmentally friendly and efficient cable solution for modern buildings, data centers, communication base stations and other scenarios, with significant safety, environmental and economic value. Attached Figure Description
[0030] Figure 1 is a schematic diagram of the overall structure of an embodiment of this application;
[0031] Figure 2 is a structural schematic diagram of the cable body in an exploded state according to an embodiment of this application;
[0032] Figure 3 is a structural schematic diagram of the fireproof partition in the disassembled state according to an embodiment of this application;
[0033] Figure 4 is a schematic diagram of the structure of the insulating layer in the disassembled state according to an embodiment of this application;
[0034] Figure 5 is a schematic diagram of the structure of the flame retardant layer in the decomposition state according to an embodiment of this application;
[0035] Figure 6 is a structural schematic diagram of the woven mesh tube in the disassembled state according to an embodiment of this application;
[0036] Figure 7 is a schematic diagram of the structure of the outer protective layer in the disassembled state according to an embodiment of this application;
[0037] Figure 8 is a schematic diagram of the structure of the outer coating layer in the disassembled state according to an embodiment of this application.
[0038] Explanation of reference numerals in the attached drawings: 1. Insulation layer; 11. Insulation sleeve; 12. Connecting sleeve; 13. Heat-conducting pipe; 14. Heat-conducting fin; 2. Fireproof partition; 21. Plastic support plate; 22. Wire hole; 23. Tension hole; 24. Support ring; 25. Flame-retardant filler; 3. Conductor; 4. Tension steel cable; 5. Flame-retardant layer; 51. Braided mesh tube; 511. Nylon braided layer; 512. Flame-retardant filler column; 52. Flame-retardant film; 53. Fiberglass cloth tube; 54. Steel mesh tube; 6. Outer protective layer; 61. Corrugated pipe; 62. Heat insulation film; 63. Ceramic silicone cloth; 7. Outer coating layer; 71. Mesh sleeve; 72. Filler bag; 73. Flame-retardant powder. Detailed Implementation
[0039] The present application will be further described in detail below with reference to the accompanying drawings.
[0040] This application discloses a fire-resistant coaxial cable. Referring to Figures 1, 2, 3, and 4, a fire-resistant coaxial cable includes a cable body and an outer sheath 7. The cable body includes an insulation layer 1, fire-resistant separators 2, conductors 3, tensile steel cables 4, a flame-retardant layer 5, and an outer sheath 6. Multiple fire-resistant separators 2 are spaced apart along the axial direction of the cable body inside the insulation layer 1. Multiple conductors 3 and tensile steel cables 4 are disposed inside the insulation layer 1, and the conductors 3 and tensile steel cables 4 are dispersedly distributed through the multiple fire-resistant separators 2. The flame-retardant layer 5 is sleeved on the outside of the insulation layer 1, and the outer sheath 6 is sleeved on the outside of the flame-retardant layer 5. The outer sheath 7 is sleeved and assembled on the outer wall of the outer sheath 6 of the cable body. The insulation layer 1 is responsible for isolating the conductors 3 from electrical contact with the outside world, ensuring safe circuit transmission, and effectively preventing electromagnetic interference. The fire-resistant separators 2 act like a firewall, separating the conductors 3, ensuring that the spread of fire is blocked in the event of a fire, thereby reducing the risk of cable fire. Conductor 3 provides the electrical conductivity of the circuit, ensuring smooth current transmission. Tensile steel cable 4 provides additional support to the cable, enhancing its overall mechanical strength and enabling it to withstand tension and bending. Flame-retardant layer 5 retards the cable when exposed to fire, effectively delaying the spread of fire and protecting the cable's internal structure from burning. Outer sheath 6 provides external protection, enhancing the cable's abrasion resistance and tensile strength. Furthermore, outer layer 7 provides further mechanical protection, ensuring the cable functions normally in various complex environments. In summary, these components work together to ensure the cable's safe and reliable power transmission in harsh environments such as fires. Under normal conditions, insulation layer 1 and conductor 3 transmit electrical energy, while fire-resistant separator 2 and tensile steel cable 4 protect the cable from physical and safety hazards. In the event of a fire, flame-retardant layer 5 slows the spread of fire, while outer sheath 6 and outer layer 7 ensure the cable structure remains undamaged, thus guaranteeing the safety of communication or power transmission.
[0041] Referring to Figure 4, the insulation layer 1 includes an insulating sleeve 11 and a connecting sleeve 12. The insulating sleeve 11 is made of polyolefin resin, and the connecting sleeve 12 is fitted onto the outer wall of the insulating sleeve 11. The connecting sleeve 12 is made of boron nitride-filled silicone. The insulating sleeve 11, made of polyolefin resin, can effectively prevent the cable from failing or being damaged by external factors in harsh environments, providing long-term stable electrical insulation performance. The connecting sleeve 12, made of boron nitride-filled silicone, not only has good elasticity and flexibility, but the boron nitride it contains also has good temperature resistance, effectively delaying the burning of the insulating sleeve 11 by high temperatures, thereby reducing direct damage to the cable. The insulating sleeve 11 has multiple heat-conducting pipes 13 integrally formed inside, and multiple heat-conducting fins 14 are evenly arranged on the outer wall of the multiple heat-conducting pipes 13. The multiple heat-conducting fins 14 are integrally cast with the outer wall of the multiple heat-conducting pipes 13, and the interior of the heat-conducting pipes 13 is filled with cable filler paste. The cable filler grease inside the heat pipe 13 effectively reduces the cable temperature during operation, while the design of the heat-conducting fins 14 further enhances heat conduction efficiency, helping to quickly dissipate heat from within the cable and ensuring safe and reliable operation even in high-temperature environments. Overall, this structure not only improves the cable's electrical safety and mechanical protection but also effectively enhances its heat dissipation performance, thereby extending the cable's service life and strengthening the overall stability and reliability of the system.
[0042] Referring to Figure 3, the fireproof partition 2 includes a plastic support plate 21. Multiple horizontal wire holes 22 are provided through the plastic support plate 21, through which conductors 3 are inserted. A tension hole 23 is provided at the center of the plastic support plate 21, and a support ring 24 is fixed to the middle of the inner wall of the tension hole 23. The support ring 24 is used to secure the tension cable 4. The plastic support plate 21 of the fireproof partition 2 mainly supports and guides the conductor 3. The multiple horizontal wire holes 22 are used to insert and support the conductor 3, ensuring that the conductor 3 can be reliably fixed in place in the event of a fire. The tension hole 23 provides additional tension support points, and the support ring 24 is used to fix the tension cable, enhancing the stability of the overall structure. A filler cavity is provided inside the plastic support plate 21, and the filler cavity of the plastic support plate 21 is filled with flame-retardant filler 25, which is made of compressed expandable graphite material. The hollow cavity inside the plastic support plate 21 is filled with expandable graphite material as a flame-retardant filler 25, which expands to form an isolation layer in case of fire, effectively preventing the spread of flames. This fireproof partition 2 not only provides stable support for the conductor 3, ensuring the safety of the transmission line, but also provides effective fireproof isolation in case of fire through the flame-retardant filler 25, enhancing the overall fire resistance performance, thereby protecting the conductor safety and reducing the risk of flame spread in case of fire.
[0043] Referring to Figures 5 and 6, the flame-retardant layer 5 includes a woven mesh tube 51, a flame-retardant film 52, a fiberglass cloth tube 53, and a steel mesh tube 54. The flame-retardant film 52 is disposed on the inner wall of the woven mesh tube 51, and the fiberglass cloth tube 53 is disposed on the inner wall of the flame-retardant film 52. The steel mesh tube 54 is fixed to the inner wall of the fiberglass cloth tube 53. The flame-retardant layer 5 is composed of multiple components, each playing a unique role. The flame-retardant film 52 is made of ceramicized silicone rubber material, which not only has excellent high-temperature resistance but also forms a protective film upon flame contact, further preventing the spread of flames. The fiberglass cloth tube 53 provides additional mechanical protection and heat resistance, while the steel mesh tube 54 further enhances the overall structural strength, making the entire flame-retardant layer more robust and durable. When an external fire source approaches, the inner nylon woven layer 511 and the flame-retardant filler 512 will first function, blocking and slowing the spread of flames. The fiberglass cloth tube 53 and steel mesh tube 54 provide additional protection, ensuring the stability and durability of the overall structure and jointly achieving a highly efficient flame-retardant effect. The braided mesh tube 51 consists of a nylon braided layer 511 and flame-retardant filler 512. The nylon braided layer 511 has a hollow cavity filled with flame-retardant filler 512, which is made of aluminum hydroxide. The flame-retardant film 52 is made of ceramicized silicone rubber. The nylon braided layer 511 inside the mesh tube 51 provides a certain strength and toughness, while the internal flame-retardant filler 512 effectively improves the overall fire resistance. The flame-retardant filler, made of aluminum hydroxide, decomposes and absorbs heat at high temperatures, helping to slow down the combustion process. Subsequently, the flame-retardant film 52 transforms into a ceramic-like protective film at high temperatures, forming a barrier to prevent further flame spread.
[0044] Referring to Figures 6 and 7, the outer protective layer 6 includes a corrugated pipe 61 made of galvanized steel sheet, with a heat insulation film 62 adhered to its inner wall. The corrugated pipe 61 is wrapped with a ceramic silicone cloth 63. The galvanized material of the corrugated pipe 61 in the outer protective layer 6 effectively improves its corrosion resistance and mechanical strength, ensuring stable operation of the pipe body in harsh environments. The ceramic silicone cloth 63 on the outer layer of the corrugated pipe 61 not only provides additional protection but also enhances insulation performance and prevents electromagnetic interference. In summary, this system effectively supports and protects the pipe, reduces heat conduction with the heat insulation film, enhances insulation protection with the ceramic silicone cloth, and provides double insulation with mica powder, jointly ensuring the stability and reliability of the system, making it suitable for demanding industrial environments. The heat insulation film 62 is made of aluminum foil, and mica powder is filled between the ceramic silicone cloth 63 and the corrugated pipe 61. The heat insulation film 62 inside the corrugated pipe 61 is made of aluminum foil, which can effectively reduce heat conduction, reduce the impact of external heat on the internal medium, and maintain the temperature stability of the medium. Mica powder is filled between the ceramic silicone cloth 63 and the corrugated pipe 61, which further enhances the heat insulation effect and improves the sealing and heat resistance of the structure.
[0045] Referring to Figure 8, the outer layer 7 includes a mesh sleeve 71 made of nylon. Multiple filler bags 72 are provided on the outer wall of the mesh sleeve 71, and each filler bag 72 is filled with flame-retardant powder 73. The outer layer 7 is composed of the mesh sleeve 71 and the filler bags 72. The mesh sleeve 71, made of nylon, provides good breathability and abrasion resistance, making it suitable for wrapping other components. Each filler bag 72 is filled with flame-retardant powder 73, which effectively blocks the spread of flames in the event of a fire, thus protecting the internal structure. The mesh sleeve 71 uses its mesh structure to fix the multiple filler bags 72 in appropriate positions, ensuring that the filler bags 73 are evenly distributed and achieve the best flame-retardant effect. In summary, this design provides physical support and breathability through the mesh sleeve, while the flame-retardant powder inside the filler bags plays a crucial role in flame retardancy during a fire, jointly ensuring the safety performance of the overall system.
[0046] The implementation principle of the fire-resistant coaxial cable in this application embodiment is as follows:
[0047] First, according to the location of the cable body, a combined outer layer 7 is installed on the outside of the parts that are prone to fire. When the cable body is burned by an external open flame, the open flame will burn through the packing bag 72 on the outer wall of the mesh sleeve 71 in the outer layer 7. The flame retardant powder 73 in the burned-through packing bag 72 will escape. The flame retardant powder 73 is made of magnesium hydroxide. When the flame retardant powder 73 is heated, it absorbs heat and decomposes to release water vapor, which extinguishes part of the open flame burning the cable body.
[0048] Then, when the outer sheath 6 of the cable body is burned by an open flame, the ceramic silicone cloth 63 is burned by an open flame. The ceramic silicone cloth 63 is made of glass fiber or ceramic fiber fabric base coated with high-temperature resistant silicone rubber, which has excellent high-temperature resistance and fire resistance, improving the overall fire resistance of the cable body. At the same time, the corrugated pipe 61 is made of galvanized steel plate, which has certain fire resistance. The corrugated pipe 61 structure itself has higher thermal elastic deformation capacity, which can better absorb thermal stress when heated and prevent cracking. In addition, the aluminum foil heat insulation film 62 adhered to the inner wall of the corrugated pipe 61 allows the heat from the open flame to be transferred mainly in the form of radiation. The high reflectivity layer on the inside can reflect the radiant heat back, which greatly reduces the heating effect of radiant heat on the internal insulation layer and the central conductor, protecting the core transmission structure.
[0049] Meanwhile, when the open flame burns through the outer sheath 6 and scorches the flame-retardant layer 5, and when the open flame burns through the braided mesh tube 51, the braided wire of the braided mesh tube 51 breaks and the flame-retardant filler 512 inside leaks out. The flame-retardant filler 512 is made of aluminum hydroxide. When heated, it absorbs heat and decomposes to release water vapor, which extinguishes part of the open flame's burning of the cable body. The open flame continues to burn the internal flame-retardant film 52. The flame-retardant film 52 is made of ceramicized silicone rubber film. The high temperature causes the ceramicized silicone rubber to transform into a hard ceramic shell, which fills and seals the gaps that may appear due to the melting of the plastic sheath, effectively isolating the flame and oxygen for flame retardancy. At the same time, the fiberglass cloth tube 53 and the steel mesh tube 54 work together as the final thermal barrier and structural reinforcement of the internal insulation, preventing the ceramic shell from cracking and thus providing flame retardancy.
[0050] Finally, when the open flame burns the insulation layer 1, the connecting sleeve 12 is first subjected to high-temperature burning. The boron nitride used in the connecting sleeve 12 has excellent high-temperature lubrication and insulation properties, which will cause the open flame to detach from the insulation layer 1, preventing the molten open flame from sticking to the insulation layer 1 and causing the cable to be continuously burned by the open flame. At the same time, the heat from the insulating sleeve 11 of the insulation layer 1 is conducted through the heat-conducting fins 14 into the heat-conducting pipe 13. The heat is absorbed and melted by the cable filler paste filled in it, further isolating the heat. When the open flame burns through the insulation layer 1, the flame-retardant layer 5, and the outer sheath 6, the open flame combustion causes the plastic support plate 21 in the fireproof partition 2 segmented in the cable to melt. The open flame comes into contact with the flame-retardant filler 25 filled with expansive graphite material in the form of compressed sheets. The graphite expands rapidly, forming a fluffy, worm-like carbon layer. This expanded graphite not only fills the entire annular space but also extends to both sides, sealing the cable cavities between multiple adjacent fireproof partitions 2 between the cable body.
[0051] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A fire-resistant coaxial cable, characterized in that, The cable includes a cable body and an outer sheath (7). The cable body includes an insulation layer (1), fireproof partitions (2), conductors (3), tensile steel cables (4), a flame-retardant layer (5), and an outer sheath (6). The insulation layer (1) has multiple fireproof partitions (2) spaced apart along the axial direction of the cable body. The insulation layer (1) also has multiple conductors (3) and tensile steel cables (4) inside it. The conductors (3) and tensile steel cables (4) are dispersed and pass through the multiple fireproof partitions (2). The insulation layer (1) is covered with the flame-retardant layer (5), and the flame-retardant layer (5) is covered with the outer sheath (6). The outer sheath (7) is fitted and assembled on the outer wall of the outer sheath (6) of the cable body.
2. The fire-resistant coaxial cable according to claim 1, characterized in that: The insulating layer (1) includes an insulating sleeve (11) and a connecting sleeve (12). The insulating sleeve (11) is made of polyolefin resin material, and the connecting sleeve (12) is fitted on the outer wall of the insulating sleeve (11). The connecting sleeve (12) is made of silicone material filled with boron nitride.
3. The fire-resistant coaxial cable according to claim 2, characterized in that: The insulating sleeve (11) has multiple heat-conducting pipes (13) integrally formed inside, and multiple heat-conducting fins (14) are uniformly arranged on the outer wall of the multiple heat-conducting pipes (13). The multiple heat-conducting fins (14) are integrally cast with the outer wall of the multiple heat-conducting pipes (13), and the interior of the heat-conducting pipes (13) is filled with cable filler paste.
4. The fire-resistant coaxial cable according to claim 1, characterized in that: The fireproof partition (2) includes a plastic support plate (21), on which multiple wire holes (22) are horizontally opened, and the multiple wire holes (22) are used to insert and insert support conductors (3). A tension hole (23) is opened through the center of the plastic support plate (21), and a support ring (24) is fixed in the middle of the inner wall of the tension hole (23), and the support ring (24) is used to snap and assemble tension steel cable (4).
5. The fire-resistant coaxial cable according to claim 4, characterized in that: The plastic support plate (21) has a filler cavity inside, and the filler cavity of the plastic support plate (21) is filled with flame-retardant filler (25), which is made of expansive graphite material in the form of compressed sheets.
6. The fire-resistant coaxial cable according to claim 1, characterized in that: The flame-retardant layer (5) includes a woven mesh tube (51), a flame-retardant film (52), a fiberglass cloth tube (53), and a steel mesh tube (54). The flame-retardant film (52) is disposed on the inner wall of the woven mesh tube (51), and the fiberglass cloth tube (53) is disposed on the inner wall of the flame-retardant film (52). The steel mesh tube (54) is fixed on the inner wall of the fiberglass cloth tube (53).
7. A fire-resistant coaxial cable according to claim 6, characterized in that: The braided wire of the braided mesh tube (51) is composed of a nylon braided layer (511) and flame-retardant filler (512). The nylon braided layer (511) has a hollow cavity inside, and the hollow cavity of the nylon braided layer (511) is filled with flame-retardant filler (512). The flame-retardant filler (512) is made of aluminum hydroxide material, and the flame-retardant film (52) is made of ceramicized silicone rubber film.
8. The fire-resistant coaxial cable according to claim 1, characterized in that: The outer protective layer (6) includes a corrugated pipe (61), which is made of galvanized material and has a heat insulation film (62) adhered to the inner wall of the corrugated pipe (61). The corrugated pipe (61) is wrapped with ceramic silicone cloth (63).
9. A fire-resistant coaxial cable according to claim 8, characterized in that: The heat insulation film (62) is made of aluminum foil, and mica powder is filled between the ceramic silicone cloth (63) and the corrugated pipe (61).
10. A fire-resistant coaxial cable according to claim 1, characterized in that: The outer layer (7) includes a mesh sleeve (71), which is made of nylon and has multiple filler bags (72) on its outer wall. The multiple filler bags (72) are filled with flame retardant powder (73).