A kind of polyethylene insulated power cable processing is covered with device

Abstract

The application provides a kind of polyethylene insulated power cable processing covering device, covering mechanism, including the extrusion box being arranged in the upper end of heat exchange box, the discharge end of extrusion box is provided with die head, die head is used to receive the insulating material in extrusion box and insulating material is covered to the core wire being threaded in it, to form cable;Cooling mechanism, including the elbow pipe being arranged in one side of heat exchange box, the water cooling section being arranged in vertical state and the air cooling section being arranged in horizontal state in elbow pipe, gradient cooling pipe is arranged in water cooling section, and the cooling intensity from top to bottom is stepped increasing, and a plurality of annular water cooling pipes are sleeved on each gradient of gradient cooling pipe, to solve the problem that the existing cable insulation layer automatic covering equipment cannot fully shape the insulation layer and lacks effective control of water evaporation, which affects the surface quality of insulation layer and causes large heat loss and unsatisfactory energy saving effect.

Description

Technical Field

[0001] This invention belongs to the field of power cable processing technology, and specifically relates to a coating device for processing polyethylene insulated power cables. Background Technology

[0002] Polyethylene insulated power cable coating refers to the process of uniformly coating molten polyethylene material onto the surface of the conductive core and then cooling it to form a protective layer with electrical insulation properties. In existing technologies, this process is typically achieved using a coating device.

[0003] For example, CN117393242B discloses an automatic cable insulation coating device, which includes a cooling system and an insulation coating mechanism installed at the inlet end. The cooling system has a U-shaped structure, and a heat utilization device is connected between the two ends. After the cable core passes through the insulation coating mechanism and is coated with insulation, it enters the water vertically downwards and perpendicular to the liquid surface for cooling. Water pipes are connected to opposite sides at both ends of the cooling system, and a turbine mechanism is connected between the two water pipes. However, the above patent still has the following defects in practical applications:

[0004] On the one hand, although the vertical water entry method can reduce the influence of gravity on the uniformity of the insulation layer, under high-speed production conditions, the insulation material is not fully shaped before entering the cooling system, and there is still a possibility of uneven thickness. Moreover, uneven water flow distribution in the U-shaped cooling system can easily form turbulence or dead zones, affecting the uniformity of cooling and thus disturbing the surface quality of the unsolidified insulation layer.

[0005] On the other hand, although the use of a circulating water system reduces water consumption, the lack of effective control measures for water evaporation means that heat dissipation will still lead to high evaporation losses. Furthermore, the heat recovery path of the hot air hood and hot air duct is long, resulting in large heat loss and efficiency degradation, making it difficult to fully realize the energy-saving effect.

[0006] Based on this, this application proposes a coating device for processing polyethylene insulated power cables to overcome the above-mentioned defects. Summary of the Invention

[0007] The purpose of this invention is to solve the problems of existing automatic cable insulation coating equipment failing to fully shape the insulation layer and lacking effective control over moisture evaporation, resulting in poor insulation surface quality, high heat loss, and unsatisfactory energy-saving effects.

[0008] To achieve the above objectives, the present invention provides a coating device for processing polyethylene insulated power cables, comprising:

[0009] A heat exchange box, which contains a first heat exchange component and a second heat exchange component;

[0010] The coating mechanism includes an extrusion box located at the upper end of the heat exchange box. The discharge end of the extrusion box is provided with a die head, which is used to receive the insulating material in the extrusion box and coat the insulating material onto the wire core passing through it to form a cable.

[0011] The cooling mechanism includes a bent pipe located on one side of the heat exchange box. The bent pipe has a vertically arranged water-cooled section and a horizontally arranged air-cooled section. The water-cooled section is equipped with gradient cooling pipes with progressively increasing cooling intensity from top to bottom. Each gradient cooling pipe is fitted with several annular water-cooled pipes. Each annular water-cooled pipe can circulate cold water through a first heat exchange component to water-cool and shape the cables passing through the gradient cooling pipes. The air-cooled section is equipped with air-cooled pipes with several nozzles inside. Each nozzle can circulate cold air through a second heat exchange component to air-cool and shape the cables passing through the air-cooled pipes.

[0012] Optionally, the extrusion box is provided with an extrusion screw for extruding the insulating material inside into the die head. The extrusion screw is provided with several interference flow ridges along its spiral direction, and the interference flow ridges are used to agitate the insulating material.

[0013] Optionally, the die head is provided with a receiving channel and a covering channel. The receiving channel is provided with several axially rotatable stirring rods, which are used to stir the insulating material squeezed into the receiving channel. The covering channel is connected to the lower end of the receiving channel to receive the insulating material and cover it onto the wire core inserted therein.

[0014] Optionally, each of the annular water-cooled pipes is provided with a cold water pipe and a hot water pipe facing each other for communication with the first heat exchange component.

[0015] Optionally, the first heat exchange component includes a heat exchanger, on which a first conveying and recovery component is provided. The first conveying and recovery component is used to convey cold water in the heat exchanger to a cold water pipe and recover hot water in the hot water pipe back to the heat exchanger.

[0016] Optionally, the first conveying and recovery assembly includes a cold water distribution main pipe and a hot water distribution main pipe. The cold water distribution main pipe is provided with a number of cold water branch pipes that are connected to the cold water pipes one by one, and the hot water distribution main pipe is provided with a number of hot water branch pipes that are connected to the hot water pipes one by one. Each cold water branch pipe and each hot water branch pipe is provided with a throttle valve for regulating the liquid flow rate within them.

[0017] Optionally, a heat collection space is provided on one side of the bend, and the hot water pipes are all installed in the heat collection space.

[0018] Optionally, heat sinks are symmetrically arranged on the hot water pipe, which are used to transfer the heat from the hot water pipe into the heat collection space.

[0019] Optionally, the air-cooled pipe is provided with an air supply pipe, one end of which is connected to the second heat exchange component.

[0020] Optionally, the second heat exchange component includes a heat recovery unit capable of recovering heat from the heat collection space and converting it into cold air, which is then delivered to a heat recovery unit in each nozzle via an air supply pipe.

[0021] The beneficial effects of this invention are as follows:

[0022] The present invention proposes a coating device for processing polyethylene insulated power cables. This device comprises a heat exchange box with an extrusion box at its upper end. A die is located at the discharge end of the extrusion box, receiving the insulating material and coating it onto the wire core to form a cable. A bent pipe is installed on one side of the heat exchange box, containing a vertically arranged water-cooling section and a horizontally arranged air-cooling section. The water-cooling section contains gradient cooling pipes with progressively increasing cooling intensity from top to bottom. Each gradient of the gradient cooling pipes is fitted with several annular water-cooling pipes, each capable of circulating cold water through a first heat exchange component to water-cool and shape the cable passing through the gradient cooling pipes. The air-cooling section contains air-cooling pipes with several nozzles inside, each capable of circulating cold air through a second heat exchange component to air-cool and shape the cable passing through the air-cooling pipes. Compared to existing automatic insulation coating equipment, this invention employs indirect and gradient water cooling for the cable, which can quickly remove a large amount of heat from the cable, rapidly reducing its temperature and minimizing the adverse effects of high temperatures on the cable's internal structure and performance. Further cooling with air-cooled pipes further lowers the cable temperature to a suitable range, enabling gradual shaping of the cable and preventing uneven thickness due to insufficient cooling uniformity. This, in turn, provides strong assurance for the cable's surface quality.

[0023] Furthermore, by setting up a heat collection space, heat sink, and a second heat exchange component, the present invention can realize the secondary utilization of heat, improve the overall energy utilization efficiency, and at the same time provide a stable and reliable cold source for each nozzle, resulting in significant energy-saving and environmental protection benefits.

[0024] As can be seen from the above, the technical solution of the present invention can effectively solve the problems of existing automatic cable insulation coating equipment failing to fully shape the insulation layer and lacking effective control over moisture evaporation, resulting in poor insulation surface quality, high heat loss, and unsatisfactory energy-saving effects.

[0025] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0026] The present invention can be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to denote the same or similar parts.

[0027] Figure 1 A schematic diagram of a coating device for processing polyethylene insulated power cables is shown from a first perspective according to an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of a coating device for processing polyethylene insulated power cables is shown from a second perspective according to an embodiment of the present invention;

[0029] Figure 3 A cross-sectional view of a coating apparatus for processing polyethylene insulated power cables is shown from a first perspective according to an embodiment of the present invention;

[0030] Figure 4 A cross-sectional view of a coating apparatus for processing polyethylene insulated power cables is shown from a second perspective according to an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of the structure of an extrusion box according to an embodiment of the present invention is shown;

[0032] Figure 6 A cross-sectional view of the mold head according to an embodiment of the present invention is shown;

[0033] Figure 7 A cross-sectional view of a heat exchanger according to an embodiment of the present invention is shown;

[0034] Figure 8 A cross-sectional view of a guide channel according to an embodiment of the present invention is shown.

[0035] Figure label:

[0036] 1-Heat exchanger; 2-Extrusion box; 201-Feeding port; 3-Die head; 301-Inlet channel; 4-Bend; 401-Water cooling section; 402-Air cooling section; 403-Through hole; 5-Gradient cooling pipe; 501-Spiral guide groove; 6-Annular water cooling pipe; 7-Nozzle; 8-Air cooling pipe; 9-Bearing platform; 10-Heating pipe; 11-Extrusion screw; 1101-Break ridge; 12-Motor; 13-Controller; 14-Filter layer; 15-Conical extrusion tube; 16-Feeding channel; 17-Coating channel; 1701-Wave 1702-Columnar section; 18-Agitator rod; 19-Sealing ring; 20-Cold water pipe; 21-Hot water pipe; 22-Heat exchanger; 23-Cold water main distribution pipe; 24-Hot water main distribution pipe; 25-Cold water branch pipe; 26-Hot water branch pipe; 27-Throttle valve; 28-Insulation jacket; 29-Cold insulation space; 30-Heat collection space; 31-Heat radiator; 32-Guide channel; 33-Temperature sensor array; 34-Laser diameter sensor; 35-Gas transmission pipe; 36-Heat recovery unit; 37-Heat collection tube; 38-Control panel. Detailed Implementation

[0037] To enable those skilled in the art to more fully understand the technical solutions of the present invention, exemplary embodiments of the present invention will be described more comprehensively and in detail below with reference to the accompanying drawings. Obviously, the one or more embodiments of the present invention described below are merely one or more specific ways to implement the technical solutions of the present invention, and are not exhaustive. It should be understood that other ways belonging to a general inventive concept can be used to implement the technical solutions of the present invention, and should not be limited to the embodiments described exemplary. Based on one or more embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0038] Reference Figure 1-8 An embodiment of the present invention provides a coating device for processing polyethylene insulated power cables, comprising:

[0039] Heat exchange box 1, which is equipped with a first heat exchange component and a second heat exchange component;

[0040] The coating mechanism includes an extrusion box 2 located at the upper end of the heat exchange box 1. The discharge end of the extrusion box 2 is provided with a die head 3. The die head 3 is used to receive the insulating material in the extrusion box 2 and coat the insulating material onto the wire core passing through it to form a cable.

[0041] The cooling mechanism includes a bent pipe 4 located on one side of the heat exchange box 1. The bent pipe 4 has a vertically arranged water-cooled section 401 and a horizontally arranged air-cooled section 402. The water-cooled section 401 is provided with a gradient cooling pipe 5 whose cooling intensity increases stepwise from top to bottom. Each gradient of the gradient cooling pipe 5 is fitted with several annular water-cooled pipes 6. Each annular water-cooled pipe 6 can be circulated with cold water through a first heat exchange component to water-cool and shape the cables passing through the gradient cooling pipe 5. The air-cooled section 402 is provided with an air-cooled pipe 8 with several nozzles 7 inside. Each nozzle 7 can be circulated with cold air through a second heat exchange component to air-cool and shape the cables passing through the air-cooled pipe 8.

[0042] Specifically, the gradient cooling pipe 5, by gradually decreasing its inner diameter, reduces the distance between each annular water-cooling pipe 6 and the cable, thereby achieving a step-by-step increase in cooling intensity.

[0043] In one embodiment, the lower end of the heat exchange box 1 is provided with a support platform 9 for supporting it and the bend 4.

[0044] In one embodiment, the extrusion box 2 is provided with a receiving port 201, which is used to inject insulating material from an external feeding device into the extrusion box 2.

[0045] In one embodiment, a plurality of heating tubes 10 are arranged circumferentially in the wall of the extrusion box 2. The plurality of heating tubes 10 are used to heat the insulating material in order to maintain the insulating material in a molten state.

[0046] In one embodiment, the extrusion box 2 is equipped with an extrusion screw 11 for extruding insulating material into the die 3. The extrusion screw 11 has several interference flow ridges 1101 arranged along its helical direction, all of which are used to agitate the insulating material. Specifically, the interference flow ridges 1101 can significantly enhance the agitation effect on the insulating material. By disrupting the laminar flow state of the insulating material, they promote radial mixing and shear dispersion, thereby reducing bubble formation. Furthermore, by enhancing shear force, they can break up existing bubbles and accelerate the escape of volatiles, thus improving the uniformity of the insulating material. Simultaneously, the local turbulence formed by the interference flow ridges 1101 can break the composition gradient, reducing the formation of unmelted clumps in the insulating material, thus ensuring the extrusion of the insulating material.

[0047] In one embodiment, one end of the extrusion screw 11 is connected to a motor 12 for driving its rotation.

[0048] In one embodiment, a controller 13 electrically connected to a plurality of heating tubes 10 and a motor 12 is provided inside the heat exchange box 1.

[0049] In one embodiment, a filter layer 14 is provided at the discharge end of the extrusion box 2. The filter layer 14 is used to filter the insulating material. Specifically, the filter layer 14 is made of ceramic fiber material, which has the characteristics of high temperature resistance, corrosion resistance, and high filtration accuracy. It can effectively intercept impurities and particles in the insulating material, ensuring the purity and uniformity of the insulation layer of the formed cable. On the one hand, fine filtration reduces defects and air bubbles in the insulation layer, improving the electrical performance and mechanical strength of the cable; on the other hand, it ensures a tight fit between the insulation layer and the wire core, enhancing the overall stability and service life of the cable, thereby ensuring reliable operation of the cable in complex environments.

[0050] In one embodiment, the discharge end of the extrusion box 2 is provided with a tapered extrusion tube 15 that communicates with the die head 3. Specifically, the tapered extrusion tube 15 is threadedly connected to both the extrusion box 2 and the die head 3 to facilitate maintenance of the filter layer 14 and the die head 3.

[0051] In one embodiment, the die head 3 is provided with a receiving channel 16 and a covering channel 17. The receiving channel 16 is equipped with a plurality of axially rotatable stirring rods 18, which agitate the insulating material extruded into the receiving channel 16. The covering channel 17 is connected to the lower end of the receiving channel 16 to receive and cover the insulating material onto the wire core inserted therein. Specifically, the stirring rods 18 are movably connected to the wall of the receiving channel 16 so that when the insulating material comes into contact with it, they exert a force on it, causing it to rotate axially. By continuously agitating the extruded insulating material, the agglomeration and accumulation within the insulating material are effectively broken up, promoting uniform distribution and thorough mixing of the insulating material. This not only eliminates potential voids and air bubbles in the insulating material but also significantly improves the density and physical strength of the insulation layer, providing more reliable electrical insulation performance for the cable.

[0052] In addition, the inner walls of the receiving channel 16 and the covering channel 17 are both arc-shaped to prevent insulating material from remaining on their walls and to avoid adverse effects on the covering of the wire core.

[0053] In one specific embodiment, the covering channel 17 is divided into a wave-shaped section 1701 for receiving the insulating material and a columnar section 1702 for covering the wire core. Specifically, the wave-shaped section 1701 can receive, buffer, and initially shape the insulating material, allowing it to achieve a more uniform distribution and more suitable flow before entering the columnar section 1702. The undulating structure of the wave-shaped section 1701 increases the contact area between the insulating material and the inner wall of the channel, effectively dispersing the pressure of the insulating material during flow, reducing the agglomeration and bubble formation of the insulating material, thereby improving the purity and density of the insulation layer. The columnar section 1702, with its stable cylindrical structure, ensures the uniform covering of the insulating material on the surface of the wire core, forming a uniformly thick and tightly bonded insulating protective layer. This not only optimizes the physical properties of the insulation layer but also enhances the bonding strength between the wire core and the insulation layer, effectively improving the overall electrical performance, mechanical stability, and service life of the cable, ensuring reliable operation of the cable in complex environments.

[0054] In one embodiment, the upper end of the die head 3 is provided with an inlet channel 301 for the entry of the wire core, and the lower end of the inlet channel 301 is fitted with an inverted T-shaped sealing ring 19. Specifically, the inverted T-shaped sealing ring 19 can ensure that the wire core can smoothly enter the die head 3, while also preventing the insulating material from overflowing outward from the covering channel 17, so as to ensure the stable operation of the die head 3.

[0055] In one specific embodiment, the gradient cooling pipe 5 is provided with a spiral guide groove 501 for guiding the cold air diffused to each annular water-cooling pipe 6. Specifically, the spiral guide groove 501 guides the cold air along a specific trajectory, avoiding short circuits or local accumulation of cold air inside the pipe, ensuring uniform cooling of all parts of the cable. This effectively reduces internal stress concentration and surface quality defects caused by uneven cooling. At the same time, the gradient cooling characteristics optimize the crystallization process of the insulation material, improving the mechanical strength and electrical performance of the cable, thereby providing a strong guarantee for the dimensional stability and long-term reliability of the cable during the forming process.

[0056] In one embodiment, each annular water-cooled pipe 6 is provided with a cold water pipe 20 and a hot water pipe 21 arranged opposite to each other for communication with the first heat exchange component.

[0057] In one embodiment, the first heat exchange component includes a heat exchanger 22, and a first conveying and recovery component is provided on the heat exchanger 22. The first conveying and recovery component is used to convey cold water in the heat exchanger 22 to the cold water pipe 20 and recover hot water in the hot water pipe 21 to the heat exchanger 22.

[0058] In one specific embodiment, the first conveying and recovery assembly includes a cold water distribution main pipe 23 and a hot water distribution main pipe 24. The cold water distribution main pipe 23 is provided with a plurality of cold water branch pipes 25 that are connected to the cold water pipes 20 in a one-to-one correspondence. The hot water distribution main pipe 24 is provided with a plurality of hot water branch pipes 26 that are connected to the hot water pipes 21 in a one-to-one correspondence. Each cold water branch pipe 25 and each hot water branch pipe 26 is provided with a throttle valve 27 for regulating the liquid flow rate therein.

[0059] Specifically, the heat exchanger 22 has a hot fluid channel, a cold fluid channel, and a metal wall separating the two. The recovered hot water flows as the hot fluid in the channel on one side of the heat exchanger, transferring heat to the metal wall. Simultaneously, cold water flows in the opposite direction in the channel on the other side, absorbing the heat transferred from the metal wall to lower the hot water temperature. As the hot water continues to release heat, its temperature gradually decreases until it becomes cold water, which is then transported through internal channels to the cold water distribution manifold 23. This achieves cold water circulation to each water-cooled pipe, thereby cooling the cables. The specific structure and working principle of the heat exchanger are existing technologies and will not be described in detail here.

[0060] In addition, the control terminal of the heat exchanger 22 is electrically connected to the controller 13 to realize its electrical control.

[0061] In one embodiment, an insulation sleeve 28 is provided on the outside of the cold water pipe 20 to prevent the diffusion of cold air from the cold water pipe 20. Specifically, the insulation sleeve 28 is made of polyurethane foam material. The polyurethane foam reduces heat conduction through its closed-cell structure. Through physical insulation, increased thermal resistance, and radiation reflection mechanisms, it effectively reduces heat exchange between the cold water pipe 20 and the environment, maintains a low-temperature environment inside the pipe, reduces energy consumption, and improves system efficiency.

[0062] In one embodiment, a cold insulation space 29 is provided on one side of the bend 4, and all the cold water pipes 20 are disposed within the cold insulation space 29. Specifically, the sidewall of the cold insulation space 29 is made of a vacuum insulation board, which can further reduce the loss of cold energy in the cold water pipes 20 to the environment through thermal radiation and thermal convection, and maintain the stability of the water temperature in the cold water pipes 20.

[0063] In one embodiment, a heat collection space 30 is provided on one side of the bend 4, and the hot water pipes 21 are all located in the heat collection space.

[0064] In one embodiment, heat sinks 31 are symmetrically arranged on the hot water pipe 21, and the heat sinks 31 are used to transfer the heat in the hot water pipe 21 into the heat collection space 30.

[0065] Specifically, the sidewall of the heat collection space 30 is made of a vacuum insulation panel, which, combined with the heat sink 31, can reduce the heat loss of the hot water pipe 21 and collect heat to facilitate the recovery and utilization of heat.

[0066] In one embodiment, the bend 4 is provided with an L-shaped guide channel 32 for guiding the cable. The guide channel 32 contains a temperature sensor array 33 for detecting the surface temperature of the cable and a laser diameter sensor 34 for detecting the diameter of the cable. Specifically, the L-shaped guide channel 32 within the bend 4 can guide the cable to move stably through a structured path, avoiding mechanical damage or displacement due to bending. Simultaneously, the temperature sensor array 33 and the laser diameter sensor internally form a real-time monitoring system.

[0067] Temperature sensor array 33 accurately captures the temperature gradient on the cable surface through multi-point distributed measurement and transmits it to the controller. Laser diameter sensor 34 continuously tracks cable diameter fluctuations using non-contact laser scanning technology. When dimensional deviations are detected, the controller automatically adjusts the extruder speed to ensure the cable's geometric accuracy meets standards. The synergistic effect of these two sensors not only improves the process stability of cable forming but also effectively reduces the defect rate through a dynamic feedback mechanism, ensuring the cable product's excellent electrical performance.

[0068] In addition, the guide channel 32 is made of polytetrafluoroethylene (PTFE), which has a low coefficient of friction and excellent self-lubricating properties, thus avoiding any impact on the shape of the cable during high-speed movement.

[0069] When the cable moves at high speed in the guide channel, the low friction properties of the material can significantly reduce the contact resistance between the cable and the channel wall. At the same time, the self-lubricating properties prevent the heat or particles generated by friction from adhering, thereby avoiding scratches, wear, or deformation of the cable surface due to uneven local stress.

[0070] Therefore, the guide channel not only provides a stable path for the cable, but also ensures that the cable maintains its original geometry and surface quality during movement, thereby improving the process accuracy and product reliability of cable forming.

[0071] In one embodiment, an air-cooled pipe 8 is provided with an air supply pipe 35, one end of which is connected to the second heat exchange component.

[0072] In one specific embodiment, the second heat exchange component includes a heat recovery unit 36 ​​within each nozzle 7, capable of recovering heat from the heat collection space 30 and converting it into cold air, which is then transported via a gas pipe 35. Specifically, the heat recovery unit 36 ​​is electrically connected to the controller 13 and mainly consists of an evaporator, a compressor, a condenser, and an expansion valve. The low-temperature, low-pressure refrigerant in the evaporator absorbs heat from the heat collection space 30 and evaporates into a gaseous state. This gas is then compressed into a high-temperature, high-pressure gas by the compressor, releases heat to the external environment in the condenser, and condenses into a liquid state. The liquid refrigerant, after being throttled and depressurized by the expansion valve, re-enters the evaporator to absorb heat, thereby continuously generating cold air on the evaporator side. This cold air is then transported to each nozzle 7 via the gas pipe, thus achieving secondary utilization of heat, improving overall energy efficiency, and providing a stable and reliable cold source for each nozzle 7, resulting in significant energy-saving and environmental benefits. The specific structure and working principle of the heat recovery unit 36 ​​are existing technologies, such as heat recovery air conditioning units, and will not be elaborated upon here.

[0073] In one specific embodiment, a heat collection pipe 37 is provided on the heat recovery housing 36, with one end connected to the heat collection space 30 and used for heat recovery.

[0074] In one specific embodiment, one end of the bend 4 is provided with a through hole 403 for the cable to extend outward.

[0075] In one embodiment, a control panel 38 electrically connected to the controller 13 is provided on the outer wall of the heat exchange box 1. Specifically, the controller 13 enables the operator to easily adjust the covering device of the present invention.

[0076] The coating device of the present invention operates as follows:

[0077] First, the insulating material from the external feeding equipment is injected into the extrusion box 2 through the inlet 201. The heating tube 10 is used to heat the insulating material to keep it in a molten state. At the same time, the motor 12 drives the extrusion screw 11 to rotate, and the turbulence ridges 1101 on it agitate the insulating material to reduce the generation of bubbles and improve the uniformity of the insulating material.

[0078] Subsequently, the molten insulating material is filtered through the filter layer 14 and enters the receiving channel 16 of the die head 3 through the conical extrusion tube 15. The stirring rod 18 agitates the extruded insulating material to further promote its uniform distribution. Then the insulating material enters the covering channel 17, and after being received, buffered and initially shaped in the wave section 1701, it is evenly covered onto the wire core inserted in the columnar section 1702 to form a cable.

[0079] Next, the cable enters the bend 4 and first passes through the water-cooling section 401. Then, guided by the guide channel 32, it passes through the air-cooling section 402. In the water-cooling section 401, the annular water-cooling pipes 6 fitted on each gradient of the gradient cooling pipe 5 circulate cold water through the first heat exchange component to indirectly water-cool and shape the cable. At the same time, the heat sink 31 on the hot water pipe 21 introduces heat into the heat collection space 30. In the air-cooling section 402, the heat recovery box 36 collects the heat in the heat collection space 30 through the heat collection pipe 37, converts it into cold air, and then delivers it through the air supply pipe 35 to each nozzle 7 in the air-cooling pipe 8 to air-cool and shape the cable.

[0080] During this process, the temperature sensor array 33 and the laser diameter sensor 34 monitor the surface temperature and diameter of the cable in real time and transmit the data to the controller 13 so as to adjust the process parameters in a timely manner.

[0081] Finally, the shaped cable extends outward through the through-hole 403 and connects to the external winding equipment to complete the entire wrapping process.

[0082] It is worth noting that the wire core in the coating device of the present invention can be unwound by an external unwinding device before processing, and one end is sequentially passed through the wire inlet channel 301, the receiving channel 16, the coating channel 17, the gradient cooling pipe 5, the guide channel 32, the air cooling pipe 8 and the through hole 403, and then connected to an external winding device to realize the winding of the cable.

[0083] The present invention proposes a coating device for processing polyethylene insulated power cables. This device comprises a heat exchange box with an extrusion box at its upper end. A die is located at the discharge end of the extrusion box, receiving the insulating material and coating it onto the wire core to form a cable. A bent pipe is installed on one side of the heat exchange box, containing a vertically arranged water-cooling section and a horizontally arranged air-cooling section. The water-cooling section contains gradient cooling pipes with progressively increasing cooling intensity from top to bottom. Each gradient of the gradient cooling pipes is fitted with several annular water-cooling pipes, each capable of circulating cold water through a first heat exchange component to water-cool and shape the cable passing through the gradient cooling pipes. The air-cooling section contains air-cooling pipes with several nozzles inside, each capable of circulating cold air through a second heat exchange component to air-cool and shape the cable passing through the air-cooling pipes. Compared to existing automatic insulation coating equipment, this invention employs indirect and gradient water cooling for the cable, which can quickly remove a large amount of heat from the cable, rapidly reducing its temperature and minimizing the adverse effects of high temperatures on the cable's internal structure and performance. Further cooling with air-cooled pipes further lowers the cable temperature to a suitable range, enabling gradual shaping of the cable and preventing uneven thickness due to insufficient cooling uniformity. This, in turn, provides strong assurance for the cable's surface quality.

[0084] Furthermore, by setting up a heat collection space, heat sink, and a second heat exchange component, the present invention can realize the secondary utilization of heat, improve the overall energy utilization efficiency, and at the same time provide a stable and reliable cold source for each nozzle, resulting in significant energy-saving and environmental protection benefits.

Claims

1. A coating device for processing polyethylene insulated power cables, characterized in that: include: A heat exchange box, which contains a first heat exchange component and a second heat exchange component; The coating mechanism includes an extrusion box located at the upper end of the heat exchange box. The discharge end of the extrusion box is provided with a die head, which is used to receive the insulating material in the extrusion box and coat the insulating material onto the wire core passing through it to form a cable. The cooling mechanism includes a bent pipe located on one side of the heat exchange box. The bent pipe has a vertically arranged water-cooled section and a horizontally arranged air-cooled section. The water-cooled section is equipped with a gradient cooling pipe with a step-like increase in cooling intensity from top to bottom. Each gradient cooling pipe is fitted with several annular water-cooled pipes. Each annular water-cooled pipe can be circulated with cold water through a first heat exchange component to water-cool and shape the cables passing through the gradient cooling pipe. The air-cooled section is equipped with an air-cooled pipe with several nozzles inside. Each nozzle can be circulated with cold air through a second heat exchange component to air-cool and shape the cables passing through the air-cooled pipe. The gradient cooling tube is equipped with a spiral guide groove for guiding the cold air diffused to each annular water cooling tube. Each of the aforementioned annular water-cooled pipes is provided with a cold water pipe and a hot water pipe that are arranged opposite to each other for connecting to the first heat exchange component; The first heat exchange component includes a heat exchanger, and a first conveying and recovery component is provided on the heat exchanger. The first conveying and recovery component is used to convey cold water in the heat exchanger to a cold water pipe and recover hot water in the hot water pipe back to the heat exchanger. The first conveying and recovery assembly includes a cold water distribution main pipe and a hot water distribution main pipe. The cold water distribution main pipe is provided with a number of cold water branch pipes that are connected to the cold water pipes one by one. The hot water distribution main pipe is provided with a number of hot water branch pipes that are connected to the hot water pipes one by one. Each cold water branch pipe and each hot water branch pipe is equipped with a throttle valve for regulating the liquid flow rate inside. The second heat exchange component includes a heat recovery unit capable of recovering heat from the heat collection space and converting it into cold air, which is then delivered to a heat recovery unit in each nozzle via an air supply pipe.

2. The coating device for processing polyethylene insulated power cables according to claim 1, characterized in that, The extrusion box is equipped with an extrusion screw for extruding the insulating material inside into the die. The extrusion screw is provided with several interference flow ridges along its spiral direction, which are used to agitate the insulating material.

3. The coating device for processing polyethylene insulated power cables according to claim 2, characterized in that, The die head is provided with a receiving channel and a covering channel. The receiving channel is provided with several axially rotatable stirring rods, which are used to stir the insulating material extruded into the receiving channel. The covering channel is connected to the lower end of the receiving channel to receive the insulating material and cover it onto the wire core inserted therein.

4. The coating device for processing polyethylene insulated power cables according to claim 1, characterized in that, A heat collection space is provided on one side of the bend, and the hot water pipes are all installed in the heat collection space.

5. The coating device for processing polyethylene insulated power cables according to claim 4, characterized in that, The hot water pipe is symmetrically equipped with heat dissipation fins, which are used to transfer the heat from the hot water pipe into the heat collection space.

6. The coating device for processing polyethylene insulated power cables according to claim 5, characterized in that, The air-cooled pipe is equipped with an air supply pipe, one end of which is connected to the second heat exchange component.

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