Preheating device and process for dry-method cross-linked wire conductor core

Abstract

The invention relates to a preheating device and process for a dry-method cross-linked wire conductor core. The preheating device comprises a drying bin, a heating bin and a heat preservation bin which are sequentially arranged in the set direction and communicate with one another, and a heat source assembly used for providing a heat source for the drying bin, the heating bin and the heat preservation bin. The heat source assembly comprises a heater and an air inducing device, and the heater is arranged in the heating bin and used for heating the conductor wire core; the air inducing device is installed on the heating bin and used for inducing air into the heating bin to be subjected to heat exchange with the heater and correspondingly conveying the air subjected to heat exchange to the heating bin and the heat preservation bin. According to the invention, the temperature uniformity of conductor wire core preheating can be effectively improved, the heat loss is reduced, and the heating efficiency is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cable manufacturing, and in particular to a device and process for preheating a conductor core of a dry cross-linked wire. Background Art

[0002] The dry crosslinking production line is mainly used to produce cross-linked polyethylene (XLPE) insulated cables. Its core is to form a cross-linked structure between polyethylene molecular chains through chemical or physical methods, thereby improving the material's heat resistance, mechanical strength and electrical properties. In the dry crosslinking production line, preheating of the conductor core is a key process link, mainly used to control the temperature of the conductor core before extruding the insulation layer. This step can significantly improve the extrusion quality of the insulation layer, reduce thermal stress, and optimize the uniformity of the cross-linking reaction.

[0003] There are three main methods for preheating conductor cores: (1) Induction heating, which uses electromagnetic induction to generate eddy current heating in the wire core (usually copper or aluminum conductor); this method has the advantages of fast heating speed (up to 200~300℃ / second), no impact on surrounding equipment, and high temperature control accuracy (±1℃), but it also has the disadvantage of uneven heating of large-section conductors (such as the skin effect causing the center temperature to be lower); at the same time, during the induction heating process, the induction coil itself will also generate a lot of heat, which requires a separate corresponding cooling device (such as a water cooler or air cooler) to control the coil temperature, which not only increases the operating cost, but also causes heat waste.

[0004] (2) Hot air heating: The conductor is heated by blowing a high-temperature airflow (usually 80~120℃) directly on the conductor surface. This method has simple equipment and low cost. However, the heating efficiency is low and the temperature uniformity is poor. Therefore, it is more suitable for small-section or multi-core cables. (3) Infrared heating: Infrared radiation directly acts on the conductor surface to heat the conductor. This heating method is contactless and suitable for situations where high surface cleanliness requirements are required. It is sensitive to the reflectivity of the conductor surface (for example, parameters need to be adjusted for aluminum conductors). In addition, induction heating requires a high-power power supply, and hot air heating causes severe heat loss, leading to increased production costs. At the same time, if the conductor does not enter the extruder immediately after preheating, heat loss will also lead to uneven temperature distribution, all of which will affect the final product quality and the production efficiency of the dry cross-linking production line.

[0005] In view of the above problems, the existing technology is in urgent need of improvement. Summary of the Invention

[0006] In view of this, the present invention provides a device and process for preheating the conductor core of a dry cross-linked wire, which can effectively improve the temperature uniformity of the conductor core preheating, reduce heat loss, and effectively improve the heating efficiency.

[0007] The present invention specifically discloses a preheating device for dry-crosslinked wire conductor cores, comprising a drying chamber, a heating chamber, and a heat preservation chamber arranged in sequence along a set direction and interconnected, and a heat source assembly for providing heat sources for the drying chamber, the heating chamber, and the heat preservation chamber; The heat source assembly includes a heater and an air induced draft device. The heater is arranged in the heating chamber to heat the conductor core; the air induced draft device is installed in the heating chamber to introduce air into the heating chamber for heat exchange with the heater, and the air after heat exchange is respectively transported to the heating chamber and the insulation chamber.

[0008] Furthermore, the heater is an induction heater, which includes a heating coil for heating and a heating power supply for powering the heating coil. There are multiple heaters, and the heating coils corresponding to the multiple heaters are arranged in sequence along a set direction in the heating chamber. The current frequency of the heating power supplies of any two adjacent heaters is different.

[0009] Furthermore, along the set direction, the current frequency of the heating power supplies of the plurality of heaters decreases step by step.

[0010] Furthermore, the heating chamber includes a shell, a wire tube and a middle partition. The wire tube is arranged in the shell, the heating coil is wound around the wire tube and is located in the shell, and the middle partition is arranged between the shell and the heating coil. The middle partition separates the radial gap between the shell and the heating coil into a first heat exchange chamber and a second heat exchange chamber. The first heat exchange chamber is connected to the drying chamber, and the second heat exchange chamber is connected to the insulation chamber.

[0011] Furthermore, it also includes a first buffer bin and a second buffer bin; The first buffer bin is arranged between the drying bin and the heating bin; the first buffer bin has an inlet cavity, a first heat exchange rear cavity and a second heat exchange front cavity. The inlet cavity connects the drying bin with the inlet pipe, the first heat exchange cavity and the drying bin are connected through the first heat exchange rear cavity, and the second heat exchange front cavity is connected with the second heat exchange cavity. The second heat exchange front cavity is also provided with an insulation air inlet channel for air to enter; The second buffer bin is arranged at a position between the heating bin and the insulation bin; the second buffer bin has a wire outlet cavity, a first heat exchange front cavity and a second heat exchange rear cavity, the wire outlet cavity connects the wire pipe with the insulation bin, the first heat exchange front cavity is connected with the first heat exchange cavity, and the first heat exchange front cavity is also provided with a drying air inlet channel for air to enter; the second heat exchange cavity is connected with the insulation bin through the second heat exchange rear cavity.

[0012] Furthermore, multiple guide plates are provided in the first heat exchange chamber and the second heat exchange chamber. The guide plates are semi-circular structures and have multiple holes for air to flow through. Any guide plate is axially inclined, and the inclination directions of adjacent guide plates are opposite.

[0013] Furthermore, the heat source assembly also includes an auxiliary heater and a temperature sensor. Auxiliary heaters are provided in the drying chamber and the insulation chamber, and temperature sensors are provided in the drying chamber, the shell, the wire conduit and the insulation chamber.

[0014] Furthermore, the heating chamber also includes an end cover for closing the shell. The shell is a hollow cylindrical structure arranged along a set direction. End covers are installed at both ends of the shell. The end cover is provided with a first through hole at a position corresponding to the first heat exchange chamber, and the end cover is also provided with a second through hole at a position corresponding to the second heat exchange chamber. The air induced draft device is installed on the end cover at positions corresponding to the first through hole and the second through hole.

[0015] Furthermore, it also includes an exhaust fan. The drying chamber is provided with a drying exhaust channel for discharging air from the drying chamber, and the insulation chamber is provided with an insulation exhaust channel for discharging air from the insulation chamber. Both the drying exhaust channel and the insulation exhaust channel are provided with exhaust fans.

[0016] The present invention also discloses a dry cross-linked wire conductor core preheating process, which is based on the aforementioned dry cross-linked wire conductor core preheating device and specifically includes the following steps: S1. Start the auxiliary heaters in the drying chamber and the insulation chamber. When the ambient temperature in the drying chamber reaches the set temperature I and the ambient temperature in the insulation chamber reaches the set temperature II, start the heaters. S2. Control the conductor core to pass through the drying chamber, heating chamber and insulation chamber in sequence at a set speed; S3. When the temperature of the heater coil reaches set temperature III, the draft fan and exhaust fan are turned on, and the heating power of the auxiliary heater is gradually reduced until the auxiliary heater is turned off. S4. Adjust the power of the induced draft fan and the exhaust fan so that the ambient temperature in the drying chamber is maintained at the set temperature I, and the ambient temperature in the heat preservation chamber is maintained at the set temperature II.

[0017] Beneficial effects of the present invention: The present invention discloses a device and process for preheating the conductor core of a dry-crosslinked wire, wherein the heating device is composed of a drying chamber, a heating chamber and a heat preservation chamber, and the main heat sources of the above three chambers are all derived from the heater of the heating chamber. The conductor core is directly heated by the heater to achieve preheating of the conductor core before dry crosslinking. At the same time, a drying chamber is set before heating for pre-drying to eliminate moisture on the surface of the conductor core, avoid uneven temperature distribution caused by direct heating, and simultaneously have a preheating effect, so that the conductor core is heated more quickly and efficiently after entering the heating chamber; and the setting of the heat preservation chamber ensures that the conductor core will not be directly exposed to the air after heating is completed, avoiding uneven temperature distribution due to heat loss; the present invention can effectively improve the temperature uniformity of the conductor core preheating, reduce heat loss, and effectively improve heating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is the front view of the present invention; Figure 3 This is a main structural sectional view of the present invention; Figure 4 for Figure 2 Cross-sectional view at AA in the middle; Figure 5 Schematic diagram of the explosion structure of the first buffer bin, heat bin, heat source assembly and the second buffer bin; Figure 6 Schematic diagram of the assembly structure of the first buffer bin, the heat bin, the heat source assembly and the second buffer bin; Figure 7 for Figure 6 Cross-sectional view at the middle BB; Figure 8 Schematic diagram of the arrangement structure of the guide plate in the present invention; Figure numerals: drying chamber 1, drying exhaust duct 101, window 102, heating chamber 2, insulation chamber 3, insulation exhaust duct 301, first buffer chamber 4, second heat exchange front chamber 401, first heat exchange rear chamber 402, inlet chamber 403, insulation air inlet duct 404, second buffer chamber 5, second heat exchange rear chamber 501, first heat exchange front chamber 502, outlet chamber 503, drying air inlet duct 504, heating coil 6, wire tube 7, heating power supply 8, middle partition 9, auxiliary heater 10, shell 11, protective plate 12, end cover 13, second through hole 1301, first through hole 1302, draft fan 14, exhaust fan 15, guide plate 16. DETAILED DESCRIPTION

[0019] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0020] It should be noted that, in the description of this specification, the terms "upper", "lower", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] As shown in the figure, an embodiment of the present invention specifically discloses a preheating device for dry-crosslinked wire conductor cores, including a drying chamber 1, a heating chamber 2 and an insulation chamber 3 arranged in sequence along a set direction and interconnected, and a heat source component for providing a heat source for the drying chamber 1, the heating chamber 2 and the insulation chamber 3; the heat source component includes a heater and an air inducer 14, the heater is arranged in the heating chamber 2 for heating the conductor core; the air inducer 14 is installed in the heating chamber 2 for introducing air into the heating chamber 2 for heat exchange with the heater, and the air after heat exchange is respectively transported to the heating chamber 2 and the insulation chamber 3. In this embodiment, air is introduced by a draft inducer 14, which exchanges heat with the heater, generating hot air that serves as the heat source for the drying chamber 1 and the holding chamber 3. The drying chamber 1 can pre-dry the conductor core and provide a certain temperature increase, thereby preventing uneven temperature distribution during the heating process caused by surface moisture on the conductor core. The holding chamber 3 prevents the heated conductor core from being directly exposed to cold air from the outside. In actual production, the inlet of subsequent processing steps (such as the inlet of an extruder) can be connected to the holding chamber 3. This allows the entire conductor core preheating process to utilize a composite heat source, coupling the hot air circulation system with the heating device. This improves energy utilization through forced convection, effectively enhances heat exchange efficiency, and establishes a multi-stage temperature compensation mechanism. In this embodiment, the draft inducer 14 can be a blower or industrial fan, preferably a fan, and is set in the direction of delivery to the conductor core during processing. In this embodiment, different gases can also be used as the heat exchange medium instead of air for conductor cores of different materials to prevent oxidation. This is well understood by those skilled in the art and will not be elaborated here.

[0022] In this embodiment, the heater is an induction heater, comprising a heating coil 6 for heating and a heating power supply 8 for powering the heating coil 6. Multiple heaters are provided, and the heating coils 6 corresponding to each of the multiple heaters are arranged sequentially along a set direction within the heating chamber 2. The current frequencies of the heating power supplies 8 of any two adjacent heaters are different. In this embodiment, the current frequencies of the heating power supplies 8 of the multiple heaters decrease stepwise along the set direction. The heater in this embodiment is the core area for implementing the conductor core heating process. Specifically, different types of devices can be used as heaters according to actual conditions. In this embodiment, an induction heater is preferably used, and is combined with a forced convection heat exchange system. The introduced air cooling air not only removes the heat generated by the heating coil 6 during operation, ensuring the normal operation of the heating coil 6, but also the hot air generated after heat exchange serves as a heat source for the drying chamber 1 and the insulation chamber 3, effectively improving energy utilization. Multiple groups of heating coils 6 with different current frequencies are provided within the heating chamber 2. Their function is to generate a deep penetrating eddy current effect through electromagnetic induction, overcoming the temperature gradient problem of the conductor cross section caused by the skin effect. The present invention constructs a synergistic mechanism between a three-stage gradient temperature control structure and a hot air circulation system. Through a continuous process path of pretreatment in the drying chamber 1, main heating in the heating chamber 2, and constant temperature maintenance in the insulation chamber 3, combined with a heat energy redistribution system driven by the draft fan 14, it not only solves the temperature attenuation problem after traditional single-stage heating, but also realizes the coordinated utilization of heat energy between different chambers, thereby improving heating uniformity while reducing overall energy consumption. In this embodiment, multiple heaters are provided, and the power supply frequencies of each heater are different. The heating power supply 8 in this embodiment is used to provide high-frequency alternating current (1-100kHz), including components such as a high-frequency inverter (IGBT or MOSFET), a resonant capacitor and a control system. Different power supply frequencies of the induction heater will result in different heating effects. For example, high-frequency induction heating (10-100kHz) has a fast heating speed and an obvious skin effect (suitable for surface heating); low-frequency induction heating (1-10kHz) takes into account both penetration depth and heating speed. In this embodiment, three groups of heaters are provided, and their power supply frequencies are designed to be 30Hz, 10kHz and 3kHz respectively. Of course, those skilled in the art can make corresponding adjustments based on the material and wire diameter of the conductor core. This embodiment adopts this step-by-step frequency configuration so that the high-frequency current preferentially heats the conductor surface, while the low-frequency current enhances the penetration into the internal area of ​​the conductor; optimizes the heating uniformity of the conductor core; and ensures that the conductor is processed in sections at different heating stages to form a progressive heating process. Adjacent heaters use power supplies with different current frequencies. By adjusting the current frequency, the skin depth is changed. High-frequency current heats the surface of the conductor, while low-frequency current enhances penetration into the inner area of ​​the conductor, thereby weakening the skin effect limitations caused by a single frequency.This multi-frequency combination heating method covers the different depths of the conductor core, ultimately achieving a balanced temperature gradient from the surface to the core area, solving the problem of uneven heating of large-cross-section conductors. In this embodiment, a window 102 is also provided in the drying chamber to facilitate observation of the status of the conductor core and whether it has entered the heating chamber correctly. In this embodiment, auxiliary devices such as the conductor conveyor are not specifically described, but those skilled in the art can easily install corresponding auxiliary devices in appropriate locations based on this embodiment to ensure the smooth progress of the preheating process.

[0023] In this embodiment, the heating chamber 2 includes a shell 11, a wire tube 7, and a middle partition 9. The wire tube 7 is arranged in the shell 11, the heating coil 6 is wound around the wire tube 7 and is located in the shell 11, and the middle partition 9 is arranged between the shell 11 and the heating coil 6. The middle partition 9 separates the radial gap between the shell 11 and the heating coil 6 into a first heat exchange chamber and a second heat exchange chamber. The first heat exchange chamber is connected to the drying chamber 1, and the second heat exchange chamber is connected to the insulation chamber 3. As shown in the figure, in this embodiment, the wire tube 7 is used to separate the conductor core from the heating coil 6 to prevent the outside air from entering and affecting the temperature of the conductor core. At the same time, it ensures sufficient heat exchange between the air and the heating coil 6. The middle partition 9 in this embodiment is divided into two separate pieces, which are symmetrically arranged along the radial direction of the shell 11. The middle partition 9 separates the radial gap between the shell 11 and the heating coil 6 into a first heat exchange chamber and a second heat exchange chamber. There are many ways to fix the wire tube in this embodiment, such as fixing it to the shell through a bracket. In this embodiment, a protective plate 13 is also provided on the outer surface of the shell. The wiring harness of the heating coil needs to pass through the shell to be connected to the heating power supply. The setting of the protective plate is to avoid direct exposure of the wiring harness during operation, thereby improving production safety.

[0024] In this embodiment, a first buffer bin 4 and a second buffer bin 5 are also included. The first buffer bin 4 is arranged between the drying bin 1 and the heating bin 2; the second buffer bin 5 is arranged between the heating bin 2 and the insulation bin 3. The setting of the first buffer bin 4 and the second buffer bin 5 is to provide a buffer for air entering and leaving the heating bin 2, so that its flow is more uniform and stable.

[0025] As shown in the figure, the first buffer bin 4 has an inlet cavity 403, a first heat exchange rear cavity 402, and a second heat exchange front cavity 401. The inlet cavity 403 connects the drying bin 1 with the inlet pipe. The first heat exchange cavity is connected to the drying bin 1 through the first heat exchange rear cavity 402. The second heat exchange front cavity 401 is connected to the second heat exchange cavity. The second heat exchange front cavity 401 is also provided with an insulation air inlet channel 404 for air to enter. The second buffer bin 5 has an outlet cavity 503, a first heat exchange front cavity 502, and a second heat exchange rear cavity 501. The outlet cavity 503 connects the threading tube 7 with the insulation bin 3. The first heat exchange front cavity 502 is connected to the first heat exchange cavity. The first heat exchange front cavity 502 is also provided with a drying air inlet channel 504 for air to enter. The second heat exchange cavity is connected to the insulation bin 3 through the second heat exchange rear cavity 501. The present application realizes the effective buffering and mixing of hot air between the drying bin 1, the heating bin 2, and the insulation bin 3, thereby improving the heat exchange efficiency. At the same time, the conductor core is transmitted in a closed channel, reducing heat loss. In addition, the zone-controlled air flow method helps maintain temperature uniformity in the drying chamber 1 and the insulation chamber 3, improving the overall preheating effect.

[0026] In this embodiment, a plurality of guide plates 16 are provided in the first heat exchange chamber and the second heat exchange chamber. The guide plates 16 are semi-circular structures and are provided with a plurality of holes for air to flow through. Any guide plate 16 is arranged to be axially inclined, and the inclination directions of adjacent guide plates 16 are opposite. The guide plate 16 in this embodiment is radially attached to the inner wall surface of the heating chamber at one end and to the surface of the heating coil at the other end. The guide plate 16 divides the first heat exchange chamber and the second heat exchange chamber into a plurality of independent small chambers, and each small chamber is connected through the holes on the guide plate 16; in the axial direction, the guide plate 16 is also tilted, and in the same chamber, the tilt directions of adjacent guide plates 16 are opposite. Such an arrangement allows the air entering the first heat exchange chamber or the second heat exchange chamber to be guided and diverted by the guide plate 16. Part of the air directly passes through the holes and enters the next small chamber directly, and the remaining air is blown toward the surface of the induction coil along the tilt direction of the guide plate 16 for deep convection heat exchange before entering the next chamber. Under this design, the air stays in the heating chamber longer and flows more specifically, which makes the heat exchange effect better. Moreover, the inclination directions of the guide plates 16 corresponding to the first heat exchange chamber and the second heat exchange chamber are opposite, that is, if the first heat exchange chamber is arranged in a "W" shape, the guide plates 16 in the second heat exchange chamber are arranged in an "M" shape. This design makes the flow directions of the gas medium in the two heat exchange chambers completely opposite, and the inflow and outflow directions are opposite, and the flow directions are opposite, so that the heat exchange of the coil is more sufficient, which is more conducive to the cooling of the inductive coil and the recovery and reuse of the heat of the inductive coil, effectively reducing the production cost and improving the economy.

[0027] In this embodiment, the heat source assembly also includes an auxiliary heater 10 and a temperature sensor. Auxiliary heaters 10 are installed in both the drying chamber 1 and the holding chamber 3. Temperature sensors are also installed in the drying chamber 1, the housing 11, the conduit 7, and the holding chamber 3. In this embodiment, auxiliary heaters 10 are also installed in the heating chamber 2 and the holding chamber 3. These auxiliary heaters 10 are used to provide heat during the initial startup phase of the equipment, ensuring that the drying chamber 1 and the holding chamber 3 are ready for operation. They also supplement the primary heat source, accelerating the initial temperature rise and enabling the drying chamber 1 and the holding chamber 3 to quickly enter operational status. The auxiliary heaters 10 can be made of resistance heating wires or heating plates, with a power range of 500W to 2000W. The temperature sensors can be made of thermocouples or thermistors, with a temperature measurement range of 0°C to 300°C. Two to four auxiliary heaters 10 are installed in each of the drying chamber 1 and the holding chamber 3, evenly distributed along the chamber walls. Three to five temperature sensors are installed in each of the drying chamber 1 and the holding chamber 3, distributed in the upper, middle, and lower portions of the chambers. Two to four temperature sensors are installed on the inner surface of the housing 11, evenly distributed along the axial direction. Two to three temperature sensors are installed on the inner wall of the threading tube 7, evenly distributed along the axial direction. The auxiliary heater 10 and the temperature sensors are connected through a control system to achieve closed-loop temperature control.

[0028] In this embodiment, the heating chamber 2 further includes an end cover 13 for closing the shell 11. The shell 11 is a hollow cylindrical structure arranged along a set direction. The end covers 13 are installed at both ends of the shell 11. The end cover 13 is provided with a first through-hole at a position corresponding to the first heat exchange chamber, and the end cover 13 is also provided with a second through-hole at a position corresponding to the second heat exchange chamber. The draft inducer 14 is installed on the end cover 13 at positions corresponding to the first through-hole and the second through-hole. In this embodiment, the first heat exchange chamber and the second heat exchange chamber are respectively separated by a partition plate to form a bidirectional 6-channel structure. The end cover 13 is provided with 3 first through-holes and 3 second through-holes. In order to reduce manufacturing costs, the first heat exchange chamber and the second heat exchange chamber are provided with a draft inducer 14 only at one end thereof, or they can be provided on both sides at the same time. This is a choice that those skilled in the art can make based on actual needs and will not be elaborated here.

[0029] In this embodiment, an exhaust fan 15 is also included. The drying chamber 1 is provided with a drying exhaust channel 101 for discharging air from the drying chamber 1, and the insulation chamber 3 is provided with an insulation exhaust channel 301 for discharging air from the insulation chamber 3. Both the drying exhaust channel 101 and the insulation exhaust channel 301 are provided with an exhaust fan 15. As shown in the figure, in order to improve the efficiency of heat convection and ensure the stability of the pressure in each chamber, the exhaust fan 15 shown in the figure is also provided in this embodiment. The start and stop conditions of the exhaust fan 15 should be coupled with the temperature and pressure of the corresponding chamber. That is, when the temperature of the corresponding chamber is too low, the exhaust fan 15 needs to be stopped to reduce heat source loss, and the auxiliary heater 10 needs to be turned on for heat compensation. This is understandable to those skilled in the art and will not be elaborated here.

[0030] The embodiment of the present invention further discloses a dry cross-linked wire conductor core preheating process, which is based on the aforementioned dry cross-linked wire conductor core preheating device and specifically includes the following steps: S1. Start the auxiliary heater 10 in the drying chamber 1 and the insulation chamber 3. When the ambient temperature in the drying chamber 1 reaches the set temperature I and the ambient temperature in the insulation chamber 3 reaches the set temperature II, start the heater. In this embodiment, the set temperature I and the set temperature II are generally between 70 and 120°C (adjusted according to the conductor material, cross-section and production line speed). For example, copper conductors are generally set at 80 to 100°C, and aluminum conductors are generally set at 60 to 80°C (to avoid oxidation). The specific temperature parameters can be set by those skilled in the art and will not be described in detail here.

[0031] S2. Control the conductor core to pass through drying chamber 1, heating chamber 2, and insulation chamber 3 in sequence at a set speed. The set speed needs to be adjusted according to the parameters of each link of the production line to ensure the highest economic efficiency while ensuring product quality.

[0032] S3. When the temperature of the heating coil 6 of the to-be-heated heater itself is raised to the set temperature III, the draft fan 14 and the exhaust fan 15 are turned on, and the heating power of the auxiliary heater 10 is gradually reduced until the auxiliary heater 10 is turned off; in this embodiment, the set temperature III depends on the heating coil 6 itself. Under different materials, different diameters and different power supply frequencies, the normal operating temperature range of the heating coil 6 is different. The set temperature III is based on its normal operating temperature range, which is understandable to those skilled in the art and will not be elaborated here.

[0033] S4. Adjust the power of the induced draft fan 14 and the exhaust fan 15 so that the ambient temperature in the drying chamber 1 is maintained at the set temperature I, and the ambient temperature in the heat preservation chamber 3 is maintained at the set temperature II.

[0034] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A device for preheating the core of a dry cross-linked wire conductor, characterized in that: It includes a drying chamber, a heating chamber and a heat preservation chamber which are sequentially arranged along a set direction and are interconnected, and a heat source component for providing heat source for the drying chamber, the heating chamber and the heat preservation chamber; The heat source assembly includes a heater and an air inducer. The heater is arranged in the heating chamber for heating the conductor core; the air inducer is installed in the heating chamber for introducing air into the heating chamber for heat exchange with the heater, and the air after heat exchange is transported to the heating chamber and the insulation chamber respectively.

2. The device for preheating the core of a dry cross-linked wire conductor according to claim 1, characterized in that: The heater is an induction heater, which includes a heating coil for heating and a heating power supply for powering the heating coil. There are multiple heaters, and the heating coils corresponding to the multiple heaters are arranged in sequence along a set direction in the heating chamber. The current frequency of the heating power supplies of any two adjacent heaters is different.

3. The device for preheating the core of a dry cross-linked wire conductor according to claim 2, characterized in that: Along the set direction, the current frequency of the heating power supplies of the plurality of heaters decreases step by step.

4. The device for preheating the core of a dry cross-linked wire conductor according to claim 2, characterized in that: The heating chamber includes a shell, a wire tube and a middle partition. The wire tube is arranged in the shell, the heating coil is wound around the wire tube and is located in the shell, and the middle partition is arranged between the shell and the heating coil. The middle partition separates the radial gap between the shell and the heating coil into a first heat exchange chamber and a second heat exchange chamber. The first heat exchange chamber is connected to the drying chamber, and the second heat exchange chamber is connected to the insulation chamber.

5. The device for preheating the core of a conductor of a dry cross-linked wire according to claim 4, characterized in that: Also includes a first buffer bin and a second buffer bin; The first buffer bin is arranged between the drying bin and the heating bin; the first buffer bin has an inlet cavity, a first heat exchange rear cavity and a second heat exchange front cavity; the inlet cavity connects the drying bin with the inlet pipe, the first heat exchange cavity is connected with the drying bin through the first heat exchange rear cavity, the second heat exchange front cavity is connected with the second heat exchange cavity, and the second heat exchange front cavity is further provided with a heat preservation air inlet channel for air to enter; The second buffer bin is arranged at a position between the heating bin and the insulation bin; the second buffer bin has a wire outlet cavity, a first heat exchange front cavity and a second heat exchange rear cavity, the wire outlet cavity connects the threading pipe with the insulation bin, the first heat exchange front cavity is connected with the first heat exchange cavity, and the first heat exchange front cavity is also provided with a drying air inlet channel for air to enter; the second heat exchange cavity is connected with the insulation bin through the second heat exchange rear cavity.

6. The device for preheating the core of a dry cross-linked wire conductor according to claim 5, characterized in that: A plurality of guide plates are provided in the first heat exchange chamber and the second heat exchange chamber. The guide plates are semi-circular structures and have a plurality of holes for air to flow through. Any of the guide plates is arranged to be axially inclined, and the inclination directions of adjacent guide plates are opposite.

7. The device for preheating the core of a dry cross-linked wire conductor according to claim 4, characterized in that: The heat source assembly further includes an auxiliary heater and a temperature sensor. Auxiliary heaters are provided in the drying chamber and the heat preservation chamber. Temperature sensors are provided in the drying chamber, the shell, the wire threading pipe and the heat preservation chamber.

8. The device for preheating the core of a dry cross-linked wire conductor according to claim 1, characterized in that: The heating chamber also includes an end cover for closing the shell. The shell is a hollow cylindrical structure arranged along a set direction. End covers are installed at both ends of the shell. The end cover is provided with a first through hole at a position corresponding to the first heat exchange cavity, and the end cover is also provided with a second through hole at a position corresponding to the second heat exchange cavity. The air inducer is installed on the end cover at positions corresponding to the first through hole and the second through hole.

9. The device for preheating the core of a dry cross-linked wire conductor according to claim 1, characterized in that: It also includes an exhaust fan. The drying chamber is provided with a drying exhaust channel for discharging air from the drying chamber, and the insulation chamber is provided with an insulation exhaust channel for discharging air from the insulation chamber. Both the drying exhaust channel and the insulation exhaust channel are provided with exhaust fans.

10. A dry cross-linking wire conductor core preheating process, characterized by: The process is based on the device for preheating the core of a dry cross-linked wire conductor according to any one of claims 1 to 9, and specifically comprises the following steps: S1. Start the auxiliary heaters in the drying chamber and the insulation chamber. When the ambient temperature in the drying chamber reaches the set temperature I and the ambient temperature in the insulation chamber reaches the set temperature II, start the heaters. S2. Control the conductor core to pass through the drying chamber, heating chamber and insulation chamber in sequence at a set speed; S3. When the temperature of the heater coil reaches set temperature III, the draft fan and exhaust fan are turned on, and the heating power of the auxiliary heater is gradually reduced until the auxiliary heater is turned off. S4. Adjust the power of the induced draft fan and the exhaust fan so that the ambient temperature in the drying chamber is maintained at the set temperature I, and the ambient temperature in the heat preservation chamber is maintained at the set temperature II.

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