An intrinsically safe isolated copper sheathed fire resistant cable

Abstract

The application discloses an intrinsically safe isolated copper sheath fireproof cable, which comprises a copper sheath and a plurality of conductors, the plurality of conductors are uniformly distributed in the copper sheath, the copper sheath has high melting point and thermal stability, an air bag is arranged between two adjacent conductors, the air bag is filled with expansion material, the expansion material expands under heat, a heat insulation layer is arranged between the copper sheath and the conductors, the heat insulation layer is made of silicone rubber base material, the silicone rubber base material has high elasticity and thermal stability, a plurality of grooves are formed on the surface of the copper sheath, the grooves correspond to the conductors one by one, the plurality of conductors form a cavity, and a pushing piece is arranged in the cavity and used for pushing the conductors to move. The application has the effect of fireproof cable flame retardation.

Description

An intrinsically safe isolated copper-sheathed fireproof cable Technical Field

[0001] This invention relates to the field of cable technology, and in particular to an intrinsically safe, isolated, copper-sheathed fireproof cable. Background Technology

[0002] As a core component ensuring the safety of power transmission, communication cables play an irreplaceable and crucial role in modern industrial and civil building systems. Especially in flammable and explosive environments such as natural gas storage and transportation, rail transit, and high-rise buildings, the reliability of their fire resistance performance is directly related to the success or failure of fire prevention and control, and even determines the safety of people's lives, the preservation of equipment and property, and the maintenance of social public interests.

[0003] Related technology can be found in Chinese Patent No. CN212461212U, which discloses a copper-sheathed environmentally friendly fireproof cable. This cable includes several copper conductors, each wrapped with an insulation layer. An inner sheath is provided outside the insulation layer, and fire-resistant cotton is filled between the inner sheath and the insulation layer. A composite fire-resistant layer is provided outside the inner sheath, followed by an armor layer, and finally a copper sheath. The proposed copper-sheathed environmentally friendly fireproof cable has an outer copper sheath made of highly conductive and corrosion-resistant copper strip through longitudinal corrugated welding. It features sealing and waterproofing, corrosion resistance, high conductivity, and a melting point up to 1000℃. The internal composite fire-resistant layer has excellent fire resistance and flame retardancy, low smoke, halogen-free, non-toxic properties, good flexibility, and a temperature resistance exceeding 950℃.

[0004] Regarding the aforementioned technologies, fire-resistant cables can only simply isolate external high temperatures or external combustion. When a short circuit occurs in the copper conductor, the rapid increase in current causes the copper conductor to heat up quickly in a short time, and may even cause combustion. Since the short circuit point is usually located inside the cable, external fire prevention measures cannot directly act on the short circuit point. The fire spreads rapidly inside the cable and is difficult to detect and control in time, thus affecting the flame-retardant effect of the fire-resistant cable. Summary of the Invention

[0005] To improve the flame-retardant effect of fire-resistant cables, this application provides an intrinsically safe isolated copper-sheathed fire-resistant cable.

[0006] This application provides an intrinsically safe isolated copper-sheathed fire-resistant cable, employing the following technical solution:

[0007] An intrinsically safe, isolated copper-sheathed fireproof cable includes a copper sheath and several conductors. The conductors are evenly distributed within the copper sheath. The copper sheath has a high melting point and thermal stability. An air bladder is provided between adjacent conductors, and the air bladder is filled with an expansion material that expands when heated. A heat insulation layer is provided between the copper sheath and the conductors. The heat insulation layer is made of a silicone rubber base material, which has high elasticity and thermal stability. Several grooves are formed on the surface of the copper sheath, and each groove corresponds to a conductor. The conductors form a cavity, and a pushing element is provided within the cavity to push the conductors to move.

[0008] By adopting the above technical solutions, the high melting point and thermal stability of the copper sheath can ensure the structural integrity and performance stability of the cable in high-temperature environments, reducing the probability of damage to the internal conductor caused by external combustion. The copper sheath has thermal conductivity, and the silicone rubber base acts as a heat insulation layer to reduce the probability of external heat being transferred to the internal conductor. When a short circuit occurs in the internal conductor, the conductor temperature rises, causing the expansion material in the air bladder to expand due to heat, which pushes the conductor outward. At this time, the pushing component simultaneously pushes the conductor to move, causing the conductor to move towards the groove, increasing the distance between the conductors, reducing the probability of internal combustion, and improving the flame retardant effect of the fireproof cable.

[0009] Optionally, a protective film is provided in the groove, and a sensing plate is located on the side of the protective film near the copper sheath. The sensing plate is electrically connected to the external system and is used to send signals to the external system.

[0010] By adopting the above technical solution, the airbag and the pusher push the conductor to move into the groove, so that the groove contacts the sensing sheet. After sensing the situation, the sensing sheet can transmit the signal to the external system in a timely manner, so that the staff can control the short circuit in time and improve the flame retardant effect of the fireproof cable.

[0011] Optionally, an insulating layer is provided on the outside of the conductor. The insulating layer is made of polyethylene material and is used to reduce the probability of current leakage between the conductor and the outside world.

[0012] By adopting the above technical solution, polyethylene material has extremely high insulation resistance, which can effectively reduce the probability of current leakage in the cable insulation layer. During operation, the current mainly flows along the conductor and does not leak into the surrounding environment through the insulation layer, thus ensuring the electrical safety and efficiency of the cable.

[0013] Optionally, a waterproof tape is wrapped around the outside of the insulation layer. The surface of the waterproof tape is coated with a hydrophobic coating. The waterproof tape is used to reduce the probability of liquid coming into contact with the conductor.

[0014] By adopting the above technical solution, a waterproof tape coated with a hydrophobic coating is wrapped around the outside of the insulation layer. This design not only enhances the cable's waterproof performance but also effectively reduces faults such as short circuits that may be caused by liquid contact with the conductor, thereby significantly improving the reliability of cable operation.

[0015] Optionally, a thermally conductive layer is provided on the outside of the waterproof strip. The thermally conductive layer is made of thermally conductive silicone. A heat dissipation plate is provided on the outside of the thermally conductive layer. The heat dissipation plate is made of aluminum and has a thickness of 0.5mm. Heat dissipation holes are provided on the surface of the heat dissipation plate. The diameter of the heat dissipation holes is 2mm and the spacing is 5mm.

[0016] By adopting the above technical solution, the heat generated by the conductor is transferred to the aluminum heat sink by the thermally conductive layer made of thermally conductive silicone. The heat dissipation area is effectively increased by the heat dissipation holes with specific diameter and spacing on the surface of the heat sink. This not only significantly improves the heat dissipation efficiency of the cable and reduces the risk of heat accumulation and damage on the conductor, but also extends the service life of the cable.

[0017] Optionally, the pusher includes a push rod located between the conductors, the push rod being elastic, and the push rod containing expanded graphite that expands at high temperatures.

[0018] By adopting the above technical solution, the expansion force of the expanded graphite at high temperature is superimposed with the elastic restoring force of the push rod to form a stronger thrust, which pushes the conductor to move towards the groove, increases the distance between the conductors, reduces the probability of short circuits damaging adjacent conductors, and improves the flame retardant effect of the fireproof cable.

[0019] Optionally, the outer side of the copper sheath is provided with an armor layer, which includes several armor pieces. The armor pieces are evenly distributed along the length of the cable, and one side of the armor piece is inserted into the inner side of the adjacent armor piece.

[0020] By adopting the above technical solutions, cables often face risks of mechanical impact, wear, and chemical corrosion. The armored plates have excellent tensile and compressive strength, effectively protecting the cable and reducing the probability of damage from external impacts, thereby significantly improving the cable's service life and reliability.

[0021] Optionally, an outer protective layer is provided on the outside of the armor layer. Several receiving grooves are opened on the surface of the outer protective layer. The receiving grooves are filled with fire extinguishing agents. A baffle is provided at the receiving groove. The baffle is made of thermoplastic resin, which turns into liquid at high temperature.

[0022] By adopting the above technical solution, when an external fire occurs, the baffle made of thermoplastic resin in the outer protective layer receiving tank becomes liquid, allowing the fire extinguishing agent filled in the receiving tank to be released and sprayed out. After being sprayed out, the fire extinguishing agent will quickly cover the burning area, and through the inhibitory effect of its chemical components, reduce the spread of fire, thereby achieving the fire extinguishing function and improving the fire safety of the cable.

[0023] Optionally, a waterproof membrane is provided inside the container, and the waterproof membrane is fixedly connected to the inner wall of the container. The waterproof membrane is used to reduce the contact between the liquid and the fire extinguishing agent.

[0024] By adopting the above technical solution, after the baffle turns into a liquid at high temperature, the waterproof membrane reduces the probability of the extinguishing agent failing due to contact with the liquid, thus ensuring the effectiveness of the extinguishing agent in the outer protective layer's containment tank.

[0025] Optionally, the expansion material can be carbon dioxide or hydrogen.

[0026] By adopting the above technical solution and using carbon dioxide or hydrogen as an expansion material, it can effectively expand when heated, providing better isolation and protection between two adjacent conductors and ensuring the safe operation of the cable.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] When a short circuit occurs in the internal conductor, the conductor temperature rises, causing the expansion material inside the airbag to expand due to heat. This causes the airbag to push the conductor outward, and at the same time, the pushing component pushes the conductor to move, causing the conductor to move towards the groove. The distance between the conductors increases, reducing the probability of internal combustion and improving the flame retardant effect of the fireproof cable.

[0029] Polyethylene material has extremely high insulation resistance, which can effectively reduce the probability of current leakage in the cable insulation layer. During operation, the current mainly flows along the conductor and does not leak into the surrounding environment through the insulation layer, thereby improving the safety of cable use.

[0030] Armored plates have excellent tensile and compressive strength, effectively protecting cables and reducing the probability of damage from external impacts, thereby significantly improving the service life and reliability of cables. Attached Figure Description

[0031] Figure 1 is a schematic diagram of the overall structure of an intrinsically safe isolated copper-sheathed fireproof cable.

[0032] Figure 2 is a cross-sectional schematic diagram designed to highlight the copper sheath connection structure.

[0033] Figure 3 is a cross-sectional schematic diagram designed to highlight the conductor connection structure.

[0034] Figure 4 is a schematic diagram designed to highlight the connection structure of the armor plates.

[0035] Explanation of reference numerals in the attached drawings: 1. Conductor; 11. Insulation layer; 12. Waterproof tape; 13. Thermal conductive layer; 14. Heat sink; 141. Heat dissipation hole; 15. Push rod; 16. Airbag; 2. Copper sheath; 21. Groove; 211. Protective film; 212. Sensing plate; 22. Armored plate; 23. Outer protective layer; 231. Waterproof membrane; 232. Baffle; 233. Receiving groove; 24. Heat insulation layer. Detailed Implementation

[0036] The present application will be further described in detail below with reference to all the accompanying drawings.

[0037] This application discloses an intrinsically safe, isolated, copper-sheathed fireproof cable. Example

[0038] Referring to Figures 1 and 2, an intrinsically safe isolated copper-sheathed fireproof cable includes a copper sheath 2 and several conductors 1. The conductors 1 are evenly distributed within the copper sheath 2. The copper sheath 2 has a high melting point and thermal stability, which enables the cable to maintain stable performance in high-temperature environments and reduces the probability of damage to the internal conductors 1 caused by external combustion. An insulation layer 11 is provided on the outside of the conductors 1. The insulation layer 11 is made of polyethylene material. Polyethylene material has extremely high insulation resistance, which can effectively reduce the probability of current leakage in the cable insulation layer 11. During operation, the current mainly flows along the conductors 1 and will not leak into the surrounding environment through the insulation layer 11, thereby ensuring the electrical safety and efficiency of the cable.

[0039] Referring to Figure 3, a waterproof tape 12 is wrapped around the outside of the insulation layer 11. The surface of the waterproof tape 12 is coated with a hydrophobic coating, which makes the waterproof tape 12 hydrophobic and reduces the penetration of water through the cable surface into the interior of the insulation layer 11. This reduces the probability of short circuits and other faults that may be caused by liquid contact with the conductor 1, thereby significantly improving the reliability of cable operation.

[0040] Referring to Figure 3, a thermally conductive layer 13 is provided on the outside of the waterproof tape 12. The thermally conductive layer 13 is made of thermally conductive silicone. A heat dissipation plate 14 is provided on the outside of the thermally conductive layer 13. The heat dissipation plate 14 is made of aluminum and has a thickness of 0.5 mm. The thermally conductive layer 13 transfers the heat generated by the conductor 1 to the heat dissipation plate 14. Heat dissipation holes 141 are provided on the surface. The diameter of the heat dissipation holes 141 is 2 mm and the spacing is 5 mm. The heat dissipation plate 14 dissipates heat through the heat dissipation holes 141, which improves the heat dissipation efficiency of the cable, reduces the risk of heat accumulation on the conductor 1 and damage, and can also extend the service life of the cable.

[0041] Referring to Figure 3, a heat insulation layer 24 is provided between the copper sheath 2 and the heat sink 14. The heat insulation layer 24 is made of silicone rubber base material. Silicone rubber base material has good high elasticity and can deform when subjected to external force and quickly return to its original shape after the force is removed. This characteristic allows the heat insulation layer 24 to adapt to various mechanical stresses that the cable may encounter during operation, such as bending, stretching and compression, without being damaged by deformation. At the same time, silicone rubber base has excellent thermal stability, and its temperature resistance range is usually between -60℃ and 200℃. This characteristic allows the heat insulation layer 24 to operate stably for a long time in high-temperature environments, reducing the probability of external heat being transferred to the inside of the conductor 1 through the copper sheath 2 and improving the flame retardant effect of the fireproof cable.

[0042] Referring to Figures 1 and 2, an air bladder 16 is provided between each pair of adjacent conductors 1. The air bladder 16 is filled with an expansion material, which can be carbon dioxide or hydrogen. When a short circuit occurs in the internal conductor 1, the temperature of the conductor 1 rises, causing the expansion material in the air bladder 16 to expand due to heat. Several grooves 21 are provided on the surface of the copper sheath 2, and the grooves 21 correspond one-to-one with the conductors 1. After the air bladder 16 expands, it pushes the conductors 1 to move outward toward the grooves 21, thereby increasing the distance between the conductors 1, reducing the probability of combustion of the non-short-circuited conductors 1, and improving the flame-retardant effect of the fireproof cable.

[0043] Referring to Figures 1 and 2, a cavity is formed between several conductors 1. A push rod 15 is provided in the cavity. The push rod 15 is elastic and contains expanded graphite. When the expanded graphite expands at high temperature, it is superimposed with the elastic restoring force of the push rod 15 to form a thrust, which pushes the conductors 1 to move towards the groove 21, thereby increasing the distance between the conductors 1, reducing the probability of short circuits damaging adjacent conductors 1, and improving the flame retardant effect of the fireproof cable.

[0044] Referring to Figures 1 and 2, a protective film 211 is provided at the groove 21. The protective film 211 has a sensing element 212 on the side close to the copper sheath 2. The sensing element 212 is electrically connected to the external system. The airbag 16 and the pusher push the conductor 1 to move towards the groove 21, so that the groove 21 contacts the sensing element 212. The sensing element 212 can transmit the signal to the external system in a timely manner after sensing the situation, so that the staff can control the short circuit in time and improve the flame retardant effect of the fireproof cable.

[0045] Referring to Figures 1 and 4, the outer side of the copper sheath 2 is provided with an armor layer, which includes a number of armor pieces 22. The armor pieces 22 are evenly distributed along the length of the cable, and one side of the armor piece 22 is inserted into the inner side of the adjacent armor piece 22. The armor pieces 22 have excellent tensile strength and compressive strength. Cables often face the risks of mechanical impact, wear and chemical corrosion. The armor pieces 22 effectively protect the cable and reduce the probability of the cable being damaged by external collisions, thereby improving the service life and reliability of the cable.

[0046] Referring to Figures 1 and 2, an outer protective layer 23 is provided on the outside of the armor layer. Several receiving grooves 233 are formed on the surface of the outer protective layer 23. The receiving grooves 233 are filled with fire extinguishing agents. A baffle 232 is provided at the receiving groove 233. The baffle 232 is made of thermoplastic resin. The baffle 232 is solid at room temperature, which reduces the probability of impurities in the external environment coming into contact with the fire extinguishing agents. When an external fire occurs, the baffle 232 made of thermoplastic resin at the receiving groove 233 of the outer protective layer 23 becomes liquid, allowing the fire extinguishing agents filled in the receiving grooves 233 to be released and sprayed out. After being sprayed out, the fire extinguishing agents will quickly cover the burning area and effectively extinguish the flames through the inhibitory effect of their chemical components, thereby achieving the fire extinguishing function, reducing the spread of fire, and improving the fire safety of the cable. A waterproof membrane 231 is provided inside the receiving tank 233. The waterproof membrane 231 is fixedly connected to the inner wall of the receiving tank 233. After the baffle 232 turns into liquid at high temperature, the waterproof membrane 231 reduces the probability of the extinguishing agent failing due to contact with the liquid, thus ensuring the effectiveness of the extinguishing agent in the receiving tank 233 of the outer protective layer 23.

[0047] The implementation principle of an intrinsically safe isolated copper-sheathed fireproof cable according to this application embodiment is as follows: When the external environment of the cable is burning, the baffle 232 changes from solid to liquid at high temperature. At this time, the baffle 232 no longer blocks the receiving groove 233, allowing the fire extinguishing agent filled in the receiving groove 233 to be sprayed out, thereby achieving the fire extinguishing function and reducing the spread of fire. When the internal conductor 1 is short-circuited, the temperature of the conductor 1 will rise sharply. The high temperature generated by the conductor 1 will cause the expansion material in the airbag 16 to expand rapidly under the action of high temperature. At the same time, the expansion graphite in the push rod 15 connected to the airbag 16 will expand due to heat. The expansion of the airbag 16 and the push rod 15 will cooperate with each other to push the conductor 1 towards the groove 21. As the conductor 1 moves, the distance between the conductors 1 gradually increases, reducing the probability of short circuit causing damage to adjacent conductors 1 and improving the flame retardant effect of the fireproof cable.

[0048] 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. An intrinsically safe, isolated copper-sheathed fireproof cable, comprising a copper sheath (2) and a plurality of conductors (1), characterized in that: The conductors (1) are evenly distributed within the copper sheath (2). The copper sheath (2) has a high melting point and thermal stability. Airbags (16) are provided between adjacent conductors (1), and each airbag (16) is filled with an expanding material that expands when heated. A heat insulation layer (24) is provided between the copper sheath (2) and the conductors (1). The heat insulation layer (24) is made of a silicone rubber base material, which has high elasticity and thermal stability. Several grooves (21) are formed on the surface of the copper sheath (2), each groove (21) corresponding to a conductor (1). A protective film (211) is provided at each groove (21). An induction plate (212) is provided on the side of the protective film (211) closest to the copper sheath (2). The induction plate (212) is electrically connected to an external system. The conductors (1) 1) A cavity is formed, and a pusher is provided in the cavity. The pusher is used to push the conductor (1) to move. The pusher includes a push rod (15). The push rod (15) is located between the conductors (1). The push rod (15) is elastic and contains expanded graphite. The expanded graphite expands at high temperature. When the internal conductor (1) is short-circuited, the high temperature generated by the conductor (1) causes the expansion material in the airbag (16) to expand due to heat. At the same time, the expanded graphite in the push rod (15) connected to the airbag (16) expands due to heat. The airbag (16) and the pusher cooperate to push the conductor (1) to move towards the groove (21), so that the groove (21) contacts the sensing sheet (212). The sensing sheet (212) can transmit the signal to the external system in a timely manner after sensing the situation.

2. The intrinsically safe isolated copper-sheathed fireproof cable according to claim 1, characterized in that: An insulating layer (11) is provided on the outside of the conductor (1). The insulating layer (11) is made of polyethylene material and is used to reduce the probability of current leakage between the conductor (1) and the outside world.

3. The intrinsically safe isolated copper-sheathed fireproof cable according to claim 2, characterized in that: The insulating layer (11) is wrapped with a waterproof tape (12) on the outside. The surface of the waterproof tape (12) is coated with a hydrophobic coating. The waterproof tape (12) is used to reduce the probability of liquid contact with the conductor (1).

4. The intrinsically safe isolated copper-sheathed fireproof cable according to claim 3, characterized in that: The waterproof strip (12) has a heat-conducting layer (13) on the outside. The heat-conducting layer (13) is made of thermally conductive silicone. A heat dissipation plate (14) is provided on the outside of the heat-conducting layer (13). The heat dissipation plate (14) is made of aluminum. The thickness of the heat dissipation plate (14) is 0.5 mm. Heat dissipation holes (141) are provided on the surface of the heat dissipation plate (14). The diameter of the heat dissipation holes (141) is 2 mm and the spacing is 5 mm.

5. The intrinsically safe isolated copper-sheathed fireproof cable according to claim 1, characterized in that: The copper sheath (2) has an armor layer on the outside. The armor layer includes several armor pieces (22). The armor pieces (22) have good tensile strength and compressive strength. The armor pieces (22) are evenly distributed along the length of the cable. One side of the armor piece (22) is inserted into the inner side of the adjacent armor piece (22).

6. The intrinsically safe isolated copper-sheathed fireproof cable according to claim 5, characterized in that: An outer protective layer (23) is provided on the outside of the armor layer. Several receiving grooves (233) are opened on the surface of the outer protective layer (23). The receiving grooves (233) are filled with fire extinguishing agents. A baffle (232) is provided at the receiving groove (233). The baffle (232) is made of thermoplastic resin. The thermoplastic resin becomes liquid at high temperature.

7. The intrinsically safe isolated copper-sheathed fireproof cable according to claim 6, characterized in that: The receiving tank (233) is provided with a waterproof membrane (231), which is fixedly connected to the inner wall of the receiving tank (233). The waterproof membrane (231) is used to reduce the contact between the liquid and the fire extinguishing agent.

8. The intrinsically safe isolated copper-sheathed fireproof cable according to claim 1, characterized in that: The expansion material is carbon dioxide.

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