Flame-retardant flexible fireproof environment-friendly crosslinked polyethylene cable

Abstract

The invention relates to the technical field of cross-linked polyethylene cables, and provides a flame-retardant flexible fireproof environment-friendly cross-linked polyethylene cable which comprises a metal conductor, a cross-linked polyethylene insulating layer, an outer sheath, a detachable protective layer and a communicating piece, the detachable protective layers are detachably arranged outside the outer sheath, a plurality of liquid channels used for circulating liquid to flow are formed in the detachable protective layers, and the communicating pieces are arranged at the two ends of the liquid channels and used for connecting every two adjacent detachable protective layers and communicating the liquid channels in every two adjacent detachable protective layers. And meanwhile, the liquid channel is closed when connection is not carried out, and the communicating piece located at the end communicates with external circulating equipment so as to introduce circulating liquid into the detachable protective layer. According to the technical scheme, the problem that in the prior art, in a long-time combustion environment, an active cooling structure is lacked, and the replacement cost is high after the cable is damaged is solved.

Description

Technical Field

[0001] This invention relates to the field of cross-linked polyethylene cable technology, specifically to a flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable. Background Technology

[0002] Ordinary cables, under the erosion of high-temperature flames, will rapidly decompose, carbonize, and detach their insulation and sheath layers, leading to exposed cores and a quick short circuit. Cross-linked polyethylene (XLPE) is widely used as cable insulation material due to its excellent electrical properties, heat resistance, and mechanical strength. To further improve the flame retardant performance of cables, flame retardants are added to the insulation or sheath. The flame retardant performance of cables with added flame retardants is improved. However, whether it is XLPE insulation material or flame retardant material, current cables mainly rely on the flame retardant material for passive fire protection. After the cable is heated, it lacks an active cooling function. The cable continues to heat up under the baking of external flames. Even with the addition of flame retardant materials, the outer sheath of the cable will still slowly burn under prolonged open flame combustion. After the flame is extinguished, the cable outer sheath is damaged, requiring cable repair or replacement. However, since the outer sheath of current cables is mostly integrally extruded and molded, the replacement cost is high. Summary of the Invention

[0003] This invention proposes a flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable to solve the problem that existing cables lack an active cooling structure in long-term combustion environments, resulting in high replacement costs after damage.

[0004] The technical solution of this invention is as follows: A flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable, comprising a metal conductor, a cross-linked polyethylene insulation layer, and an outer sheath, wherein the cross-linked polyethylene insulation layer is disposed outside the metal conductor, the outer sheath is disposed outside the cross-linked polyethylene insulation layer, and both the cross-linked polyethylene insulation layer and the outer sheath contain a flame retardant. The cable also includes: A removable protective layer, comprising multiple layers, is detachably disposed outside the outer sheath to withstand external combustion in place of the outer sheath. The removable protective layer contains a flame retardant and has multiple liquid channels for circulating liquid flow. The removable protective layer includes: A semi-cylindrical protective sleeve, wherein two semi-cylindrical protective sleeves are provided, and the two semi-cylindrical protective sleeves can be spliced ​​together to form a complete ring that fits tightly against the outer side of the outer protective sleeve; A connecting member, disposed at both ends of the liquid channel, is used to connect two adjacent removable protective layers and to connect the liquid channels on the two adjacent removable protective layers. When not connected, it closes the liquid channel. The connecting member at one end is connected to an external circulation device to allow circulating liquid to flow into the interior of the removable protective layer. The connecting member includes: Connector 1 and connector 2 are respectively connected to both ends of the liquid channel, and connector 1 and connector 2 are flush with the ends of the removable protective layer; The insertion tube is connected to the outer end of the first connecting seat through a communication port. The end of the insertion tube away from the first connecting seat has an air outlet, and the outer end of the second connecting seat has an insertion port for inserting the insertion tube. A baffle is provided inside the connecting seat by a compression spring to close the communication port. The diameter of the baffle is larger than the diameter of the communication port and smaller than the inner diameter of the connecting seat. The second baffle is disposed inside the second connecting seat by a compression spring and is used to close the socket. The diameter of the second baffle is larger than the diameter of the socket and smaller than the inner diameter of the second connecting seat. A top rod is fixedly connected to one end of the second baffle near the socket. When the two removable protective layers are pressed together, the insert tube is inserted into the inside of the socket, pushing the second baffle away from the socket. At the same time, the push rod pushes the first baffle away from the communication port to realize the connection between the first connecting seat and the second connecting seat.

[0005] To improve the cooling and flame-retardant effect on the cable, a liquid storage chamber is provided inside the removable protective layer, and the liquid storage chamber is connected to the liquid channel.

[0006] To improve the stability of the removable protective layer, a limiting block is fixedly connected to the end of the semi-cylindrical protective sleeve and a limiting groove matching the limiting block is provided. After the two semi-cylindrical protective sleeves are spliced ​​together, the limiting block is inserted into the corresponding limiting groove to limit the semi-cylindrical protective sleeve.

[0007] To improve the stability of the removable protective layer, a clamp for securing the removable protective layer is detachably provided on the outside of the removable protective layer at the end.

[0008] To achieve mutual restraint between the removable protective layers, the connecting seams of the semi-cylindrical protective sleeves in two adjacent removable protective layers are staggered, and the liquid channels are circumferentially arranged at equal angles on the removable protective layers. The removable protective layers can be restrained by the connecting parts.

[0009] To ensure the sealing of the connecting parts, multiple sealing rings are fixedly connected to the outside of the insertion tube, and the sealing rings are tightly attached to the inner wall of the insertion port.

[0010] The working principle and beneficial effects of this invention are as follows: 1. In this invention, a removable protective layer is added to the outside of the outer sheath. An external open flame burns the removable protective layer, thereby protecting the outer sheath and reducing damage to the outer sheath. The removable protective layer uses its own elasticity and connecting parts to connect and limit the two removable protective layers, which makes it easy to replace the specific removable protective layer after it is damaged, instead of replacing the entire cable after the outer sheath is damaged, as is the case with existing cables.

[0011] 2. In this invention, a low-temperature liquid is supplied to the liquid channel and the liquid storage chamber through an external circulation device to actively cool the cable, especially after the fire starts. With the help of flame retardants, the active cooling of the cable can further delay the burning of the cable, especially the outer removable protective layer. At the same time, after the removable protective layer is damaged, the low-temperature liquid inside leaks out and wets the cable, which has the effect of extinguishing the flame.

[0012] 3. In this invention, the liquid channel and the liquid storage chamber are pre-stored with cryogenic liquid. When the removable protective layer is not connected, that is, when the insertion tube is not inserted into the interior of the connecting seat 2, the baffle 1 and baffle 2 are sealed by the compression spring 1 and the compression spring 2 to prevent cryogenic liquid leakage. When the insertion tube is inserted into the interior of the connecting seat 2, it pushes open the baffle 2, and the push rod on the baffle 2 pushes open the baffle 1, realizing the connection of the liquid channels in the two adjacent removable protective layers. At the same time, the insertion tube limits the removable protective layer. The connecting seams on the two adjacent removable protective layers are staggered to mutually restrict and limit each other, preventing the removable protective layer from detaching. Attached Figure Description

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0014] Figure 1 This is a first-view structural diagram of the entire invention; Figure 2 This is a second-view structural schematic diagram of the entire invention; Figure 3 This is a side view of the planar structure of the present invention; Figure 4 This is a first-view structural schematic diagram of the removable protective layer and connecting member of the present invention. Figure 5 This is a second-view structural schematic diagram of the removable protective layer and connecting member of the present invention; Figure 6This is a schematic diagram of the liquid storage chamber, the removable protective layer, and the second connecting seat of the present invention. Figure 7 This is a schematic diagram of the connecting element of the present invention; Figure 8 This is a schematic diagram of the structure of the connector, insert, baffle, and compression spring of the present invention. Figure 9 This is a schematic diagram of the structure of the connecting seat 2, baffle 2, compression spring 2 and top rod of the present invention; Figure 10 For the present invention Figure 1 A magnified schematic diagram of the partial structure at point A in the middle; Figure 11 For the present invention Figure 2 A magnified schematic diagram of the structure at point B in the middle.

[0015] In the picture: 1. Metal conductor; 2. Inner semiconductor layer; 3. Cross-linked polyethylene insulation layer; 4. Outer semiconductor layer; 5. Copper shielding layer; 6. Metal armor layer; 7. Outer sheath; 8. Liquid storage chamber; 9. Clamp; 101. Half-cylinder protective sleeve; 102. Limiting block; 201. Connecting seat one; 202. Connecting seat two; 203. Insert tube; 204. Baffle one; 205. Baffle two; 206. Sealing ring; 207. Compression spring one; 208. Compression spring two; 209. Push rod. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] like Figures 1 to 11 As shown, this embodiment proposes a flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable, including a metal conductor 1, an inner semiconductor layer 2, a cross-linked polyethylene insulation layer 3, an outer semiconductor layer 4, a copper shielding layer 5, a metal armor layer 6, and an outer sheath 7. The cross-linked polyethylene insulation layer 3 is disposed outside the metal conductor 1, and the outer sheath 7 is disposed outside the polyethylene insulation layer. The inner semiconductor layer 2, the cross-linked polyethylene insulation layer 3, the outer semiconductor layer 4, the copper shielding layer 5, the metal armor layer 6, and the outer sheath 7 are sequentially wrapped around the outside of the metal conductor 1. The cross-linked polyethylene insulation layer 3 and the outer sheath 7 both contain flame retardants. The cable also includes a detachable protective layer and a connecting component.

[0018] like Figures 1 to 6As shown, multiple removable protective layers are provided. These removable protective layers are detachably installed outside the outer sheath 7 to withstand external combustion, replacing the outer sheath 7. The removable protective layers contain flame retardants and can be made of the same material as the outer sheath 7. To ensure cable flexibility, the thickness of the outer sheath 7 in this embodiment is set to be less than the thickness of the outer sheath 7 in current cables. The outer sheath 7 and the removable protective layers together constitute the external protective structure of the cable. Multiple liquid channels for circulating liquid are provided on the removable protective layers. To improve the cooling and flame-retardant effect on the cable, a liquid storage chamber 8 is provided inside the removable protective layer. The liquid storage chamber 8 is connected to a liquid channel. The removable protective layer includes a semi-cylindrical protective sleeve 101. Two semi-cylindrical protective sleeves 101 are provided, and the two semi-cylindrical protective sleeves 101 can be spliced ​​together to form a complete ring that fits tightly against the outer side of the outer sheath 7. A limiting block 102 is fixedly connected to the end of the semi-cylindrical protective sleeve 101 and has a limiting groove that matches the limiting block 102. After the two semi-cylindrical protective sleeves 101 are spliced ​​together, the limiting block 102 is inserted into the corresponding limiting groove. The internal structure uses a semi-cylindrical protective sleeve 101 for limiting movement. Two semi-cylindrical protective sleeves 101 are spliced ​​together to form a complete ring that wraps around the outside of the outer sheath 7, providing protection. In the event of a fire on the outside of the cable, the semi-cylindrical protective sleeve is heated first. The semi-cylindrical protective sleeve and the outer sheath 7 are made of the same material, and flame retardants are added internally to prevent ignition and slow the spread of flames after ignition. The liquid storage chamber 8 and the liquid channel contain circulating liquid, which can be water. Multiple semi-cylindrical sleeves can be circulated using external circulation equipment such as a circulation pump. The circulating liquid inside the protective sleeve 101 circulates, thereby carrying away the heat of the cable and achieving active cooling of the cable. When the half-tube protective sleeve 101 is damaged due to combustion, the leaking circulating liquid inside can wet the cable, further slowing the spread of the flames or even extinguishing the fire. After the two half-tube protective sleeves 101 are spliced ​​into a complete ring, the limiting block 102 can limit the half-tube protective sleeves 101, improving the installation accuracy and stability between the two half-tube protective sleeves 101.

[0019] like Figures 1 to 11As shown, a connecting member is installed at both ends of the liquid channel to connect two adjacent removable protective layers and to connect the liquid channels on the two adjacent removable protective layers. When not connected, it closes the liquid channel. The connecting member at one end connects to an external circulation device to allow circulating liquid to flow into the interior of the removable protective layer. The connecting member includes a first connecting seat 201, a second connecting seat 202, a tube 203, a first baffle 204, and a second baffle 205. The first connecting seat 201 and the second connecting seat 202 are respectively connected to both ends of the liquid channel. The first connecting seat 201 and the second connecting seat 202 are flush with the ends of the removable protective layer. The tube 203 connects to the outer end of the first connecting seat 201 through a connecting port. The tube 203 is located away from the first connecting seat 201. One end has an air outlet. The outer end of the connecting seat 202 has a socket for inserting the insertion tube 203. The connecting seat 202 has two sections; the section with the socket has a smaller inner diameter, and the other section has a larger inner diameter. Multiple sealing rings 206 are fixedly connected to the outside of the insertion tube 203. The sealing rings 206 are tightly fitted to the inner wall of the socket. A baffle 204 is installed inside the connecting seat 201 via a compression spring 207 to seal the connection port. The diameter of the baffle 204 is larger than the diameter of the connection port but smaller than the inner diameter of the connecting seat 201. A second baffle 205 is installed inside the connecting seat 202 via a compression spring 208 to seal the socket. The diameter of the baffle 205 is larger than the diameter of the socket but smaller than the inner diameter of the connecting seat 202. A push rod 209 is fixedly connected to one end of the baffle 205 near the socket. When the two removable protective layers are pressed together, the insert 203 is inserted into the socket, pushing the baffle 205 away from the socket. At the same time, the push rod 209 pushes the baffle 1 204 away from the connecting port to achieve the connection between the connector 1 201 and the connector 202. The semi-cylindrical protective sleeve 101 and the outer sheath 7 are made of the same material, namely PVC / PE, which has a certain degree of elasticity, thus ensuring the flexibility of the cable bending and twisting. By bending the semi-cylindrical protective sleeve 101, the insert 203 can be inserted into the socket. This allows for the disassembly and replacement of a single semi-cylindrical protective sleeve 101 after it has been burned or scratched. The sealing ring 206 ensures the sealing between the insert 203 and the socket. Furthermore, the stability of the removable protective layers is ensured by the sliding damping between the sealing ring 206 and the socket, as well as the tight arrangement of multiple removable protective layers. The close contact between adjacent removable protective layers also provides sealed protection for the outer sheath 7, reducing damage to the outer sheath 7. When the insertion tube 203 is inserted into the interior of the connecting seat 202 and contacts the baffle 205, the insertion tube 203 pushes the baffle 205 away from the socket, allowing liquid to flow through the gap between the baffle 205 and the connecting seat 202. Simultaneously, as the insertion tube 203 is inserted, the push rod 209 also pushes the baffle 1 204 away from the communication port, allowing fluid to flow through the gap between the baffle 1 204 and the connecting seat 1 201, thus achieving communication between the connecting seat 1 201 and the connecting seat 202.In other words, the connection between the liquid channels of two adjacent removable protective layers is achieved by pressing the baffles 204 and 205 against the connection port and socket respectively under the action of the compression springs 207 and 208, preventing the circulating liquid in the liquid channel from flowing out. After multiple removable protective layers are interconnected, the connecting seats 201 and 202 on the end removable protective layers can be connected to the external circulation equipment through the connection of the insertion tube 203 and the socket. The circulation equipment can be a circulation pump, which can circulate the circulating liquid between multiple liquid channels. The inlet and outlet of the circulation pump are connected to a circular water pipe, and the water pipe is equipped with an insertion tube 203 or a connecting seat 202, thereby realizing... The circulating pump is connected to the removable protective layers at both ends. The flow of circulating fluid carries away the heat generated by the cable and, in the event of a fire on the outside of the cable, removes heat from the flames, further delaying the combustion of the removable protective layers. When one of the removable protective layers is damaged, the insertion tube 203 can be pulled out from inside the connecting seat 202, detaching the connection between the two adjacent removable protective layers. The corresponding removable protective layer can then be removed and replaced. When the insertion tube 203 is pulled out, the pressure spring 208 causes the baffle 205 to seal the connecting seat 202, and the pressure spring 207 causes the baffle 204 to seal the connecting seat 201, reducing leakage of circulating fluid during replacement.

[0020] like Figures 1 to 2 As shown, to improve the stability of the removable protective layer, a clamp 9 for securing the removable protective layer is detachably installed on the outside of the removable protective layer at the end. The clamp 9 is a conventional metal fastener known to those skilled in the art for fixing pipes, cables, and other objects by clamping. Its structural design incorporates multiple technical solutions such as spiral fastening, end locking, and grooved pin connection, which can clamp the removable protective layer at the end to the outside of the outer sheath 7, ensuring the stability of the removable protective layer at the end. To achieve mutual restraint between the removable protective layers, the connecting seams of the semi-cylindrical protective sleeves 101 in adjacent removable protective layers are staggered. The channel is set at equal angles around the circumference of the removable protective layer. The removable protective layer can be limited by the connecting piece. Multiple removable protective layers are tightly attached to each other. The removable protective layers at both ends are kept stable by the clamp 9, so that the removable protective layer in the middle position can be kept stable. The clamp 9 can also be used to reinforce the removable protective layer at the bending position or other easily loosened position. The opening directions of two adjacent removable protective layers are perpendicular to each other, so they can restrict each other. Together with the limiting block 102, they can ensure the stability of the removable protective layer. Furthermore, the connecting seat 1 201 and the connecting seat 2 202 correspond one-to-one, so that the removable protective layer can rotate at a certain angle.

[0021] The working principle or usage process of this flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable is as follows: According to the cable length requirements, select an appropriate number of removable protective layers. Two semi-cylindrical protective sleeves 101 are tightly fitted together to form a complete ring that wraps around the outside of the outer sheath 7. The limiting block 102 is inserted into the inside of the limiting groove. Insert the tube 203 on a set of removable protective layers into the inside of the connecting seat 202 of the adjacent removable protective layer. The tube 203 pushes the baffle 205 away from the insertion port. At the same time, the push rod 209 pushes the baffle 1 204 away from the communication port, realizing the connection between the connecting seat 1 201 and the connecting seat 202, thereby connecting the adjacent liquid channels. The tube 203 and the connecting seat 202 connect the two adjacent removable protective layers. The connection seams of the two adjacent removable protective layers are perpendicular to each other, thus limiting each other and ensuring the stability of the removable protective layer connection. After all the removable protective layers are installed, the clamp 9 is installed on the outside of the removable protective layers located at the ends and in easily detachable positions to reinforce them. The removable protective layer at the end is connected to the circulation pump by the connection of the plug and connector 202. The circulation pump causes the circulating liquid in the multiple removable protective layers to flow. As the circulating liquid flows, it carries away the heat of the cable. When the cable is burning outside, the removable protective layer comes into contact with the flame to protect the outer sheath 7. The circulating liquid slows down the heating of the removable protective layer, and after the removable protective layer burns, the circulating liquid flows out to block the spread of the fire. After the fire, the damaged removable protective layer is removed, and the new removable protective layer is installed in the replacement position by connecting the insertion tube 203 and the connecting seat 202.

[0022] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable, comprising a metal conductor (1), a cross-linked polyethylene insulation layer (3), and an outer sheath (7), wherein the cross-linked polyethylene insulation layer (3) is disposed outside the metal conductor (1), and the outer sheath (7) is disposed outside the cross-linked polyethylene insulation layer (3), and both the cross-linked polyethylene insulation layer (3) and the outer sheath (7) contain a flame retardant, characterized in that, Also includes: A removable protective layer is provided, and multiple removable protective layers are provided. The removable protective layer is detachably provided outside the outer sheath (7) and is used to replace the outer sheath (7) to withstand external combustion. The removable protective layer contains a flame retardant and has multiple liquid channels for circulating liquid flow. A connecting element is disposed at both ends of the liquid channel for connecting two adjacent removable protective layers and communicating the liquid channels on the two adjacent removable protective layers. When not connected, the liquid channel is closed. The connecting element at the end is connected to an external circulation device to allow circulating liquid to be introduced into the interior of the removable protective layer.

2. The flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable according to claim 1, characterized in that, The removable protective layer includes: The semi-cylindrical protective sleeve (101) is provided in two parts, and the two semi-cylindrical protective sleeves (101) can be spliced ​​together to form a complete ring and fit tightly against the outer side of the outer protective sleeve (7).

3. The flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable according to claim 2, characterized in that, The connecting element includes: Connector 1 (201) and connector 2 (202), wherein connector 1 (201) and connector 2 (202) are respectively connected to both ends of the liquid channel, and connector 1 (201) and connector 2 (202) are flush with the ends of the removable protective layer; The insertion tube (203) is connected to the outer end of the first connector (201) through a communication port. The end of the insertion tube (203) away from the first connector (201) has an air outlet. The outer end of the second connector (202) has an insertion port for inserting the insertion tube (203). A baffle (204) is provided inside the connecting seat (201) by a compression spring (207) to close the communication port. The diameter of the baffle (204) is larger than the diameter of the communication port and smaller than the inner diameter of the connecting seat (201). Baffle 2 (205) is disposed inside the connecting seat 2 (202) by compression spring 2 (208) to close the socket. The diameter of baffle 2 (205) is larger than the diameter of the socket and smaller than the inner diameter of the connecting seat 2 (202). A top rod (209) is fixedly connected to one end of baffle 2 (205) near the socket.

4. The flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable according to claim 3, characterized in that, When the two removable protective layers are pressed together, the insertion tube (203) is inserted into the inside of the socket and pushes the second baffle (205) away from the socket. At the same time, the push rod (209) pushes the first baffle (204) away from the communication port to realize the connection between the first connector (201) and the second connector (202).

5. The flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable according to claim 4, characterized in that, The removable protective layer has a liquid storage chamber (8) inside, and the liquid storage chamber (8) is connected to the liquid channel.

6. The flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable according to claim 5, characterized in that, The end of the semi-cylindrical protective sleeve (101) is fixedly connected to a limiting block (102) and has a limiting groove that matches the limiting block (102). After the two semi-cylindrical protective sleeves (101) are spliced ​​together, the limiting block (102) is inserted into the corresponding limiting groove to limit the semi-cylindrical protective sleeve (101).

7. The flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable according to claim 6, characterized in that, The removable protective layer located at the end is detachably provided with a clamp (9) for binding the removable protective layer.

8. The flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable according to claim 7, characterized in that, The connecting seams of the semi-cylindrical protective sleeves (101) in two adjacent detachable protective layers are staggered.

9. A flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable according to claim 8, characterized in that, The liquid channels are arranged at equal angles around the perimeter on the removable protective layer.

10. A flame-retardant, flexible, fire-resistant, and environmentally friendly cross-linked polyethylene cable according to claim 9, characterized in that, The insertion tube (203) is externally fixedly connected with multiple sealing rings (206), and the sealing rings (206) are tightly attached to the inner wall of the insertion port.

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