A halogen-free, low-smoke, fire-resistant cable

Abstract

The present invention proposes a halogen-free, low-smoke, fire-resistant cable. In order to solve the problems of heat conduction and excessive ceramicization affecting the performance of the cable part not affected by the fire and increasing maintenance costs, the armored protective layer and the separation component of the present invention are spaced apart. The separation component is a continuous folded tubular structure, which can reduce the difficulty of cable bending and adapt to laying in a narrow space. The separation component includes a folding cavity, an outer shell and an inner shell. A V-shaped groove is provided at the downward bending part of the outer shell, which contains ceramic powder occupying two-thirds of its volume. After the sealing piece in the side flow hole is heated and melted, the powder can enter the folding cavity. This design controls the spread of the ceramic reaction through a segmented structure, relieves thermal stress concentration, and enhances the thermal insulation effect. It not only ensures that the cable continues to work in a fire, but also avoids the problem of reduced flexibility caused by unnecessary ceramicization, taking into account both construction flexibility and fire-resistant reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of fire-resistant cables, and in particular to a halogen-free low-smoke fire-resistant cable. Background Art

[0002] Low-smoke, halogen-free, fire-resistant cables are essential for power transmission due to their high safety, environmental friendliness, and reliability. Their fire resistance ensures power supply during fires, while their low-smoke, halogen-free properties reduce smoke and toxic gases during fires, safeguarding personnel and minimizing damage to the environment and equipment. Furthermore, their production and use are halogen-free throughout, and their materials are easily recyclable, meeting environmental standards. Their electrical performance is stable and reliable, with excellent insulation and corrosion resistance, making them suitable for a variety of harsh environments, extending their service life, and reducing maintenance costs.

[0003] In Chinese patent 201822178454.4, the application relates to the technical field related to power cables, specifically a high-temperature fire-resistant cable for engine compartments and engines, including a shielding tape, a copper conductor, a fire-resistant layer and a flame-retardant layer. A flame retardant coating is filled between each two sets of limit baffles, the interior of the flame retardant layer is filled with a dry ice filling layer, and a plurality of sets of flame retardant plates are fixedly connected to the inner wall of the flame retardant layer, and a plurality of sets of flame retardant sheaths are sleeved on the surface of the flame retardant layer, and the plurality of sets of flame retardant sheaths are fixedly connected to the interior of the flame retardant layer. The beneficial effect is: a plurality of sets of flame retardant plates are arranged inside the flame retardant layer, so that the dry ice overflows evenly, ensuring the flame retardant quality. Through the action of the flame retardant sheath, the part of the cable that is not in contact with the fire will not be damaged, ensuring the quality of the cable and reducing the cost of use. Through the action of multiple sets of limit baffles, a segmented structure is formed again, which has good use effect and is suitable for promotion.

[0004] The armor layer of existing cables is usually a whole. The armor layer woven from metal has a certain hardness, which increases the overall hardness of the cable and makes the cable less likely to bend during laying. The ceramic material protective layer of existing fire-resistant cables is also usually a whole. In the event of a fire, due to the heat conduction of the metal armor layer and other materials inside the cable, the temperature of the cable in the non-fire area will also rise accordingly. The ceramic material has fluidity when heated, which causes the ceramicization process to extend to the non-fire area, causing unnecessary ceramicization, affecting the performance and functional integrity of other parts of the cable, and increasing the cost of subsequent maintenance and replacement. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art in that heat conduction and the fluidity of ceramic materials affect the performance of the cable part not affected by the fire and increase the maintenance cost. The present invention proposes a halogen-free, low-smoke, fire-resistant cable.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is to include an armored protective layer and a separation component. The armored protective layer and the separation component are spaced apart. The separation component is a continuous, zigzag tubular structure, and the overall shape of the separation component is a series of equidistantly arranged zigzag units connected to each other. The zigzag units make the separation component have a certain flexibility and can be telescopically deformed in the axial and radial directions. The separation component includes a folding cavity, an outer shell, and an inner shell. A V-shaped groove is provided at the downward bend of the outer shell, and ceramic powder is contained inside the V-shaped groove. A flow hole is provided on the side of the outer shell, and a sealing plate is fixedly connected to the inside of the flow hole. The sealing plate melts when heated, and the ceramic powder can enter the interior of the folding cavity through the flow hole. The interior of the folding cavity is penetrated by a partition plate, and the partition plate is used to evenly divide the space of the V-shaped groove.

[0007] Preferably, the outer wall of the armored protective layer is wrapped with a ceramic protective layer, the ceramic protective layer is spaced apart from the separation component, and the thickness of the separation component above the armored protective layer is consistent with the thickness of the ceramic protective layer.

[0008] Preferably, the outer shell is sleeved on the outside of the inner shell, and the outer shell and the inner shell together form a folding cavity. The end of the outer shell is fixedly connected to the armored protective layer, and the end of the inner shell is fixedly connected to the armored protective layer.

[0009] Preferably, the volume of the ceramic powder contained in the V-shaped groove occupies two-thirds of the volume of the V-shaped groove.

[0010] Preferably, the outer wall of the ceramicizable protective layer is wrapped with a sealed protective shell, and the sealed protective shell is used to provide sealing protection for the entire cable.

[0011] Preferably, the sealing protective shell is fixedly connected to the partition plates, and the partition plates are arranged in a ring array with respect to the inner wall of the sealing protective shell.

[0012] Preferably, the partition plate is embedded in the sides of the outer shell and the inner shell, and the partition plate is slidably connected to the outer shell and the inner shell.

[0013] Preferably, the sealing protective shell is wrapped around the outside of the folding cavity, and the sealing protective shell is slidably connected to the folding cavity.

[0014] Preferably, a wrapping layer is coaxially arranged inside the armored protective layer, the wrapping layer penetrates the interior of the armored protective layer, and the wrapping layer extends to the interior of the partition assembly, and the inner shell and the wrapping layer are slidably connected.

[0015] Preferably, a filling material is provided inside the wrapping layer, and the wrapping layer is used to wrap the filling material.

[0016] Preferably, an insulating layer penetrates the interior of the filling material, and a cable core penetrates the interior of the insulating layer.

[0017] Compared with the prior art, the beneficial effects of the present invention include: the present invention is designed with a separation component with a unique structure, which is a continuous zigzag tubular structure and is spaced apart from the armored protective layer. Its zigzag unit makes the cable flexible and can expand and contract in the axial and radial directions. Multiple bending points can disperse bending stress, improve bending flexibility, reduce bending difficulty, and facilitate installation and arrangement in space-constrained places. When heated, the sealing piece melts, and the ceramic powder can enter the folded cavity and form a composite insulation structure with the air in the cavity, which significantly improves the insulation effect of the separation component, effectively reduces the heat transfer from the armored protective layer in the fire area to the armored protective layer in the unaffected area, cuts off the heat transfer path, reduces the risk of ignition of the cable in the unaffected section, prevents the fire from spreading, and enables the cable in the unaffected section to maintain performance and structural integrity, extends the overall service life of the cable, and reduces replacement costs and workload. At the same time, the separation component evenly divides the ceramic protective layer into several sections, which can prevent the ceramic reaction from spreading uncontrollably, reduce unnecessary ceramicization, and avoid the cable becoming stiff and fragile due to overall ceramicization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The disclosure of the present invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the accompanying drawings, the same reference numerals are used to refer to the same components. Among them: Figure 1 Schematically shows a three-dimensional structural diagram of a halogen-free low-smoke fire-resistant cable proposed according to one embodiment of the present invention; Figure 2 Schematically shows a structural diagram of a cross section of a halogen-free, low-smoke, fire-resistant cable proposed according to one embodiment of the present invention; Figure 3 Schematically shows a structural diagram of a longitudinal section of a halogen-free, low-smoke, fire-resistant cable proposed according to one embodiment of the present invention; Figure 4 Schematically shows a structural diagram of a halogen-free, low-smoke, fire-resistant cable armored protective layer and a separation component part according to one embodiment of the present invention; Figure 5 Schematically shows a cross-sectional structural diagram of a halogen-free, low-smoke, fire-resistant cable separation component according to one embodiment of the present invention; Figure 6 Schematically shows a cross-sectional structural diagram of a ceramic powder portion of a halogen-free, low-smoke, fire-resistant cable proposed according to one embodiment of the present invention; Figure 7 Schematically shows a cross-sectional structural diagram of a halogen-free, low-smoke, fire-resistant cable separation assembly and a ceramic protective layer portion according to one embodiment of the present invention; Figure 8 Schematic diagram showing Figure 5 Schematic diagram of the enlarged structure at point A in the middle.

[0019] In the figure: 1. Armored protective layer; 2. Partition component; 3. Ceramic protective layer; 4. Sealed protective shell; 5. Wrapping layer; 6. Filling material; 7. Insulation layer; 8. Cable core; 201. Folding cavity; 202. Outer shell; 203. Inner shell; 204. Partition plate; 205. Ceramic powder; 206. Flow hole; 207. Sealing piece; 208. V-shaped groove. DETAILED DESCRIPTION

[0020] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the present invention and should not be regarded as the entire invention or as a limitation or restriction of the technical solution of the present invention.

[0021] According to one embodiment of the present invention, Figures 1 to 8 Shown.

[0022] A halogen-free, low-smoke, fire-resistant cable includes an armored protective layer 1. The armored protective layer 1 is woven from steel wires and can provide additional pressure protection for the cable. During the laying process of the cable, it may be squeezed by various external forces, such as soil pressure during underground laying, pressure from building structures, etc. The armored protective layer 1 can effectively withstand these pressures, prevent damage to the internal structure of the cable, and ensure the stability of the electrical performance of the cable. However, the armored protective layer 1 made of metal has high hardness and rigidity, which makes the cable as a whole more rigid. During the bending process, a greater external force needs to be applied, which increases the difficulty of construction. In particular, in some occasions where the space is small and the cable needs to be bent frequently, the operation will be more difficult. In some application scenarios with high space requirements, the armored cable may not meet the bending radius requirements, thereby limiting its scope of use. In order to solve this problem, the present invention is provided with a partition component 2.

[0023] The armored protective layer 1 and the separation component 2 are spaced apart. The separation component 2 is a continuous, zigzag tubular structure, and the overall shape of the separation component 2 is a series of equidistantly arranged zigzag units connected to each other. The zigzag units make the separation component 2 have a certain flexibility and can be stretched and deformed in the axial and radial directions. The zigzag tubular structure has multiple movable bending points. Compared with the straight-cylinder armor layer, when bending the cable, these bending points can more easily adapt to changes in different directions and angles, so that the cable can be bent in a smaller space, effectively improving the bending flexibility of the cable and reducing the difficulty of bending. Due to the existence of the zigzag tubular structure, the cable can use its bending characteristics when bending to achieve a smaller bending radius than a simple straight-cylinder armor layer. This is of great significance in some space-constrained occasions, such as narrow pipes, internal wiring of equipment, etc., and can make cables more convenient to install and arrange. Moreover, when the cable bends, the zigzag tubular structure can disperse the bending stress to multiple bending points and line segments, avoiding stress concentration in a certain part. The staggered arrangement with the straight-tube armor layer further enhances the stress dispersion effect, allowing the cable to bear external forces more evenly during the bending process, reducing the risk of damage to the armor layer or damage to the internal structure of the cable due to stress concentration.

[0024] Under the continuous high temperature of a fire, some of the protective layers on the outside of the cable will be melted, causing the cable to be ignited in the fire and unable to continue working, affecting the function of powering fire-fighting equipment and transmitting signals at critical moments. Therefore, the outer wall of the armored protective layer 1 is wrapped with a ceramic protective layer 3. The ceramic protective layer 3 will undergo a ceramic reaction at high temperatures to form a hard ceramic body. This layer of ceramic body has good high-temperature resistance and can withstand temperatures of more than 1,000 degrees Celsius. It can effectively isolate flames and heat, prevent the cable from being ignited in a fire, and ensure that the cable can continue to work normally when a fire occurs, powering fire-fighting equipment, transmitting signals, etc., buying time for personnel evacuation and fire-fighting work. At the same time, the ceramic layer itself has the characteristics of low smoke and halogen-free, and will not release a large amount of toxic and harmful smoke and hydrogen halide gas in a fire, reducing harm to personnel and pollution to the environment.

[0025] However, under high temperature conditions of a fire, when the ceramic protective layer 3 is ceramicized, it has a certain fluidity and expands without limit when heated, which will cause unnecessary ceramicization in areas not affected by the fire. The ceramicized material will usually become relatively hard and brittle, which will greatly reduce the flexibility of the cable. In order to provide a reliable power supply for various fire-fighting equipment, such as fire pumps, smoke exhaust fans, emergency lighting, etc., it may be necessary to lay cables or move existing cables to ensure that these equipment can operate normally at the fire scene and ensure the smooth progress of rescue work. Cables that are too hard are difficult to bend and lay, which increases the difficulty of construction and affects the rescue time. In order to solve this problem, the present invention is designed as follows: the ceramic protective layer 3 is spaced apart from the partition component 2, the thickness of the partition component 2 that is higher than the armored protective layer 1 is consistent with the thickness of the ceramic protective layer 3, and the top of the partition component 2 is in contact with the inner wall of the sealed protective shell 4, and the partition component 2 The ceramic protective layer 3 in a cable is evenly divided into several sections. The ceramic material reacts at high temperature to form a ceramic layer. The segmented arrangement and the lack of mutual circulation can prevent the ceramic reaction from spreading uncontrollably on the entire cable. In the event of a fire, heat is transferred to the cable, and only the segmented ceramic material directly affected by the high temperature will react. The adjacent segments are isolated from each other, which can reduce unnecessary ceramicization caused by heat conduction and prevent the entire cable from being ceramicized and becoming rigid and brittle. At the same time, the ceramic material will expand thermally during the heating process. If the ceramic material of the entire cable is continuous, the thermal expansion may cause excessive stress inside the material, which may cause the ceramic layer to crack or even fall off. The segmented design allows each section of the ceramic material to expand independently, which can effectively alleviate the problem of thermal stress concentration, reduce the risk of damage to the ceramic layer, and enable the cable to better maintain its electrical and mechanical properties during a fire, reducing potential damage to the cable caused by unnecessary ceramicization.

[0026] The partition component 2 includes a folding cavity 201, an outer shell 202, and an inner shell 203. The outer shell 202 is sleeved on the outside of the inner shell 203. The outer shell 202 and the inner shell 203 together enclose the folding cavity 201. The end of the outer shell 202 is fixedly connected to the armored protective layer 1, and the end of the inner shell 203 is fixedly connected to the armored protective layer 1. A V-shaped groove 208 is provided at the downward bending part of the outer shell 202. The interior of the V-shaped groove 208 contains ceramic powder 205. The volume of the ceramic powder 205 contained in the V-shaped groove 208 accounts for two-thirds of the volume of the V-shaped groove 208. When the partition component 2 is subjected to external force, When bending, the powder will disperse the external force to the entire V-shaped groove 208 space and the surrounding tube wall. Because the ceramic powder 205 is filled in the bend, when there is a tendency to over-bend, the powder will hinder the further deformation of the tube wall, so that the force is evenly distributed over a larger area, preventing the external force from being concentrated at a certain point or a small area at the bend, which may easily cause excessive bending or even rupture at that location; under the action of the ceramic powder 205, the force will be dispersed to various parts of the separation component 2, reducing the stress at any position, thereby preventing excessive bending at a certain position of the cable, and thus helping to prevent the bend from being too small, which may cause damage to the internal structure of the cable.

[0027] A flow hole 206 is provided on the side of the outer shell 202, and a sealing piece 207 is fixedly connected to the inside of the flow hole 206. When heated, the sealing piece 207 melts, and the ceramic powder 205 can enter the inside of the folding cavity 201 through the flow hole 206. When the ceramic powder 205 is heated and ceramicized and flows into the inside of the folding cavity 201, it forms a composite heat-insulating structure with the air in the cavity. The ceramic powder 205 can form a hard and heat-insulating ceramic layer at high temperature, and air is a poor conductor of heat. The combination of the two can significantly improve the heat-insulating effect, thereby improving the heat-insulating effect of the partition component 2. Since the partition component 2 is connected to the armored The protective layer 1 is set at intervals, but after the thermal insulation effect of the partition component 2 is increased, it can effectively reduce the heat transfer from the armored protective layer 1 in the fire area to the armored protective layer 1 in the unaffected area after being heated. Heat transfer is one of the important factors for the spread of fire. If the heat of the armored protective layer 1 is transferred unimpeded, the temperature around the cable in the unaffected section may rise to the flammable point, causing the cable outer sheath or surrounding combustible materials to burn, causing the fire to spread along the cable line. The partition component 2 can effectively cut off the heat transfer path, reduce the risk of ignition of the cable in the unaffected section, prevent the fire from further expanding, and help control the scope of the fire. Even after a fire, if the unaffected section of the cable is damaged due to heat transfer from the armored protective layer 1, its subsequent service life will be affected. Reducing heat transfer can enable the unaffected section of the cable to maintain better performance and structural integrity. After inspection and necessary repairs after the fire, it can continue to be used normally, thereby extending the overall service life of the cable and reducing the cost and workload of replacing the cable; since the partition component 2 and the ceramic protective layer 3 are also spaced apart, when the thermal insulation effect of the partition component 2 is improved, the ceramic protective layer 3 can also be effectively segmented, controlling its ceramicization process, and reducing unnecessary ceramicization of the ceramic protective layer 3 that is not in the high-temperature section.

[0028] A partition plate 204 runs through the interior of the folding cavity 201, and the sealing protective shell 4 is fixedly connected to the partition plate 204, and the partition plate 204 is arranged in a circular array about the inner wall of the sealing protective shell 4. The partition plate 204 is embedded in the side of the outer shell 202 and the inner shell 203, and the partition plate 204 and the outer shell 202 and the inner shell 203 are all slidably connected. The partition plate 204 is used to evenly divide the space of the V-shaped groove 208, and then to block the ceramic powder 205 located inside the V-shaped groove 208, to prevent it from flowing downward and gathering at a certain place in the cable, thereby improving its distribution uniformity and ensuring its protection and heat insulation effects.

[0029] The outer wall of the ceramic protective layer 3 is wrapped with a sealed protective shell 4, which is used to seal and protect the entire cable. The sealed protective shell 4 is wrapped around the outside of the folding cavity 201, and the sealed protective shell 4 is slidingly connected to the folding cavity 201. The sliding connection between the two is used to ensure that the telescopic performance of the folding cavity 201 is not hindered.

[0030] A wrapping layer 5 is coaxially arranged inside the armored protective layer 1. The wrapping layer 5 passes through the inside of the armored protective layer 1 and extends to the inside of the partition component 2. The inner shell 203 and the wrapping layer 5 are slidingly connected. A filling material 6 is arranged inside the wrapping layer 5. The wrapping layer 5 is used to wrap the filling material 6. The inside of the filling material 6 is penetrated by an insulating layer 7, and the inside of the insulating layer 7 is penetrated by a cable core 8.

[0031] The technical scope of the present invention is not limited to the contents of the above description. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of ​​the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A halogen-free, low-smoke, fire-resistant cable, characterized in that: The invention comprises an armored protective layer and a separation component, wherein the armored protective layer and the separation component are spaced apart, and the separation component is a continuous, zigzag tubular structure, and the overall shape of the separation component is a series of equidistantly arranged zigzag units connected to each other, and the zigzag units make the separation component have a certain flexibility, and can be telescopically deformed in the axial and radial directions, and the separation component comprises a folding cavity, an outer shell, and an inner shell, and a V-shaped groove is provided at the downward bending part of the outer shell, and ceramic powder is contained in the interior of the V-shaped groove, and a flow hole is provided on the side of the outer shell, and a sealing piece is fixedly connected to the interior of the flow hole, which is sealed when heated. The plugging piece melts, and the ceramic powder can enter the interior of the folding cavity through the flow hole. The interior of the folding cavity is penetrated by a partition plate, and the partition plate is used to evenly divide the space of the V-shaped groove; the outer wall of the armored protective layer is wrapped with a ceramic protective layer, and the ceramic protective layer and the partition component are spaced apart, and the thickness of the partition component that is higher than the armored protective layer is consistent with the thickness of the ceramic protective layer; the volume of the ceramic powder contained in the V-shaped groove accounts for two-thirds of the volume of the V-shaped groove; the outer wall of the ceramic protective layer is wrapped with a sealed protective shell, and the sealed protective shell is used to seal and protect the entire cable.

2. The halogen-free low-smoke fire-resistant cable according to claim 1, characterized in that: The outer shell is sleeved on the outside of the inner shell, and the outer shell and the inner shell together enclose a folding cavity. The end of the outer shell is fixedly connected to the armored protective layer, and the end of the inner shell is fixedly connected to the armored protective layer.

3. The halogen-free low-smoke fire-resistant cable according to claim 1, characterized in that: The sealing protection shell is fixedly connected to the partition plate, and the partition plate is arranged in a ring array with respect to the inner wall of the sealing protection shell.

4. The halogen-free low-smoke fire-resistant cable according to claim 1, characterized in that: The partition plate is embedded in the sides of the outer shell and the inner shell, and the partition plate is slidably connected to the outer shell and the inner shell.

5. The halogen-free low-smoke fire-resistant cable according to claim 1, characterized in that: The sealing protection shell is wrapped around the outside of the folding cavity, and the sealing protection shell is slidably connected to the folding cavity.

6. The halogen-free low-smoke fire-resistant cable according to claim 1, characterized in that: A wrapping layer is coaxially arranged inside the armored protective layer. The wrapping layer penetrates the inside of the armored protective layer and extends to the inside of the partition assembly. The inner shell and the wrapping layer are slidably connected.

7. The halogen-free, low-smoke, fire-resistant cable according to claim 6, characterized in that: Filling material is provided inside the wrapping layer, and the wrapping layer is used to wrap the filling material.

8. The halogen-free, low-smoke, fire-resistant cable according to claim 7, characterized in that: An insulating layer penetrates the interior of the filling material, and a cable core penetrates the interior of the insulating layer.

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