High-voltage shield cable material production device and production line body

Abstract

The application relates to the technical field of chemical raw material production equipment, and discloses a high-voltage shielding cable material production device and a production line body, which comprise an extruder and a liquid-solid mixing kettle. The extruder is provided with a first feeding opening. The liquid-solid mixing kettle is provided with a liquid feeding opening, a solid feeding opening and a mixture output opening. The mixture output opening is communicated with the first feeding opening. The solid feeding opening is used for adding carbon black. The liquid feeding opening is used for adding a carbon black solvent, so as to solve or improve the problem that the high-voltage cable is prone to breakdown.

Description

Technical Field

[0001] This application relates to the field of chemical raw material production equipment technology, specifically to a high-voltage shielded cable material production device and production line. Background Technology

[0002] The shielding layer of a high-voltage cable is a key structure to ensure the safe and stable operation of the cable, and its material properties directly affect the cable's electrical characteristics, mechanical properties, and service life.

[0003] In related technologies, the raw materials for the shielding layer of high-voltage cables are produced by directly feeding carbon black and other raw materials into an extruder. The raw materials are then used to produce high-voltage cables. This process can cause needle-like protrusions on the surface of the shielding layer of the high-voltage cable, leading to excessive localized heating and making the cable prone to breakdown. Utility Model Content

[0004] This application provides a high-voltage shielded cable material production apparatus and production line to solve or improve the problem of high-voltage cables being prone to breakdown.

[0005] In the first aspect, this application provides a high-voltage shielded cable material production apparatus, including an extruder and a liquid-solid mixing tank, the specific scheme of which is as follows.

[0006] The extruder has a first feed port; the liquid-solid mixing vessel has a liquid injection port, a solid injection port and a mixing output port, the mixing output port is connected to the first feed port, the solid injection port is used to add carbon black, and the liquid injection port is used to add carbon black solvent.

[0007] Beneficial effects: By connecting the mixing outlet of the liquid-solid mixing vessel to the first feed port of the extruder, the carbon black first contacts the solvent in an independent liquid-solid mixing vessel, dissolving the carbon black in the solvent and reducing the particle size of carbon black agglomerates. The slurry is then injected into the polymer melt undergoing plasticization through the first feed port, which is equivalent to introducing pre-dispersed carbon black into the polymer matrix. The particle size of the carbon black is reduced from the micron level to the nanometer level, and the size of carbon black agglomerates is significantly reduced. This prevents the formation of large residual agglomerates during subsequent extrusion, improves the mixing uniformity of carbon black with other polymers, and thus reduces the particle size of carbon black in high-voltage shielded cable materials. Consequently, it reduces or eliminates needle-like protrusions on the surface of the high-voltage cable shielding layer, reduces the phenomenon of excessive local heating in high-voltage cables, and solves or improves the problem of high-voltage shielded cables being prone to breakdown.

[0008] Furthermore, the slurry after mixing carbon black with solvent is injected into the polymer melt that is being plasticized through the first feed port. This is equivalent to introducing pre-lubricated and pre-dispersed carbon black into the polymer matrix. The particle size of the carbon black is reduced from the micron level to the nanometer level, which significantly reduces the frictional resistance and dispersion load that the extruder screw needs to overcome in the solid conveying and melting sections. This improves energy utilization efficiency, reduces wear on the screw and barrel, and avoids local overheating and polymer degradation caused by directly adding dry carbon black, which can lead to material embrittlement, shorten the service life of the shielding layer, and cause scorching during processing in the extruder, thus reducing production continuity.

[0009] Meanwhile, the mixed carbon black slurry is a fluid with controllable viscosity. Compared with dry carbon black powder, it can be continuously, stably, and without pulsation conveyed through pumps and pipelines, providing constant feed for the extruder and avoiding problems such as "bridging" and "pulsation" that are prone to occur when feeding dry powder, thus greatly improving the stability and continuity of the production process.

[0010] In one alternative embodiment, the first feed port is located in the middle of the extruder.

[0011] In one optional embodiment, the liquid-solid mixing vessel is equipped with an ultrasonic generator and a stirring assembly.

[0012] In one alternative embodiment, the frequency range of the ultrasonic generating component is 20 kHz to 40 kHz.

[0013] In one optional embodiment, the ratio of the injection volume velocity of the liquid injection port to the injection volume velocity of the solid injection port is not less than 4.

[0014] In one alternative embodiment, the extruder is a twin-screw extruder with a length-to-diameter ratio of not less than 40.

[0015] In one optional embodiment, the mixing outlet of the liquid-solid mixing vessel is connected to the first feeding port via a flow meter.

[0016] In one optional embodiment, a plurality of heating sleeves are arranged sequentially along the extrusion direction inside the extruder, and the temperature control range of the heating sleeves is 60°C to 180°C.

[0017] In one optional embodiment, the extruder further includes multiple conveying devices, and the extruder also includes a second feeding port. The output ports of the multiple conveying devices are all connected to the second feeding port, and the input port of each conveying device is equipped with a loss-in-weight scale. It also includes a vacuum pump, and the extruder has a vacuum exhaust port at its tail end along the extrusion direction, with the input end of the vacuum pump connected to the vacuum exhaust port.

[0018] Secondly, this application also provides a production line body, including the above-mentioned high-voltage shielded cable material production device.

[0019] Beneficial effects: Since the production line includes a high-voltage shielded cable material production device, it has the same technical effects as the high-voltage shielded cable material production device, so it will not be elaborated here. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this application, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of a high-voltage shielded cable material production device according to an embodiment of this application.

[0022] Explanation of reference numerals in the attached figures: 1. Extruder; 2. Liquid-solid mixing vessel; 3. Flow meter; 4. Conveying equipment; 5. Loss-in-weight balance; 6. Vacuum pump; 7. Base; 8. Motor; 11. First feeding port; 12. Second feeding port; 13. Vacuum exhaust port; 21. Liquid inlet; 22. Solid inlet; 23. Mixing outlet. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; they can be internal connections between two elements. The terms "parallel," "perpendicular," and "equal" include the described situation and situations similar to the described situation, the range of which is within an acceptable deviation range, wherein the acceptable deviation range is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where an acceptable deviation range for approximate parallelism can be, for example, within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where an acceptable deviation range for approximate perpendicularity can also be, for example, within 5°. "Equal" includes absolute equality and approximate equality, where an acceptable deviation range for approximate equality can be, for example, a difference between the two equal items being less than or equal to 5% of either one. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] The shielding layer of a high-voltage cable is a key structure to ensure the safe and stable operation of the cable, and its material properties directly affect the cable's electrical characteristics, mechanical properties, and service life.

[0026] In related technologies, the raw materials for the shielding layer of high-voltage cables are produced by directly feeding carbon black and other raw materials into an extruder 1 for raw material production. The raw materials are then used to produce high-voltage cables. This process can cause needle-like protrusions on the surface of the shielding layer of the high-voltage cable, leading to excessive localized heating of the high-voltage cable and making it prone to breakdown.

[0027] The following is combined with Figure 1 This describes an embodiment of the present application.

[0028] According to embodiments of this application, in one aspect, a high-voltage shielded cable material production apparatus is provided, such as... Figure 1 As shown, it includes an extruder 1 and a liquid-solid mixing vessel 2, and the specific scheme is as follows.

[0029] The extruder 1 can be a twin-screw extruder 1 or other types of extruder 1, such as a single-screw extruder 1 or a multi-screw extruder 1, etc. The extruder 1 has a first feed port 11.

[0030] The extruder 1 is fixed on the base 7 and driven by the motor 8.

[0031] Specifically, the barrel of extruder 1 is usually made of bialloy centrifugal casting material, with the inner layer being a wear-resistant alloy (such as cobalt-based, nickel-based alloy or special high-chromium cast iron) and the outer layer being high-strength cast steel to withstand the wear of high pressure, high temperature and carbon black. The screw is made of high-strength nitrided steel (such as 38CrMoAlA) or powder metallurgy tool steel, and the surface is nitrided or sprayed with tungsten carbide (WC) coating to improve wear resistance and corrosion resistance.

[0032] The first feeding port 11 is designed as a funnel-shaped structure with an adjustable gate or butterfly valve, which can be flexibly connected to the downstream equipment to facilitate control of the feeding rate and sealing. Other types of structures are also possible. The inside of the barrel is equipped with a bushing that cooperates with the screw. The bushing can be designed as a segmented type for easy maintenance and replacement.

[0033] The liquid-solid mixing vessel 2 is a container used for mixing liquids and solids. The main body of the vessel is usually made of 304 or 316L stainless steel to ensure corrosion resistance to carbon black solvents (such as mineral oil, synthetic esters, low molecular weight polyethylene wax, etc.). Internal parts that come into contact with materials, such as the agitator, can be made of 316L stainless steel or surface-hardened materials. The seals must be made of solvent-resistant materials, such as fluororubber (FKM) or perfluoroether rubber (FFKM).

[0034] The body of the liquid-solid mixing vessel 2 is a closed pressure vessel with a jacket. The jacket can be used to introduce heat transfer oil or hot water for temperature control (usually maintained at a certain temperature to reduce solvent viscosity and facilitate dispersion).

[0035] The liquid-solid mixing vessel 2 has a liquid injection port 21, a solid injection port 22 and a mixing output port 23. The mixing output port 23 is connected to the first feeding port 11. The solid injection port 22 is used to add carbon black and the liquid injection port 21 is used to add carbon black solvent.

[0036] Specifically, the liquid inlet 21 is located at the top or upper part of the vessel body and is connected to a precise liquid metering pump (such as a gear pump or plunger pump). A nozzle may be provided at the inlet to allow the liquid to enter the vessel in the form of a thin stream.

[0037] The solid injection port 22 is also located at the top of the vessel and is connected to a loss-in-weight feeder or a volumetric feeder for continuous or batch addition of carbon black. A venturi tube or pneumatic conveying interface can be provided at the inlet to prevent carbon black dust from flying and to assist it in entering the vessel.

[0038] The mixing outlet 23 is located at the bottom of the vessel and is equipped with a high-precision, wear-resistant screw pump or diaphragm pump, as well as a dynamic or static mixer to ensure uniform slurry concentration. The outlet valve is a bottom discharge valve (such as a ball valve or gate valve) to prevent sedimentation.

[0039] In the specific application process, xylene is used as an example of solvent. Xylene is added into the liquid-solid mixing vessel 2 through the liquid injection port 21, and carbon black is added into the liquid-solid mixing vessel 2 through the solid injection port 22. Then, the mixture is stirred and mixed. After the mixture is completed, it is fed into the extruder 1 through the mixing output port 23 and the first feeding port 11 for the production of high-voltage shielded cable material.

[0040] In this embodiment, such as Figure 1 As shown, the mixing outlet 23 of the liquid-solid mixing vessel 2 is connected to the first feeding port 11 of the extruder 1, so that the carbon black first comes into contact with the solvent in the independent liquid-solid mixing vessel 2, dissolving the carbon black in the solvent and reducing the particle size of carbon black agglomerates. The slurry is injected into the polymer melt that is being plasticized from the first feeding port 11, which is equivalent to introducing pre-dispersed carbon black into the polymer matrix. The particle size of carbon black is reduced from the micron level to the nano level, and the size of carbon black agglomerates is greatly reduced. This ensures that no large agglomerates remain in the subsequent extrusion process, improves the mixing uniformity of carbon black with other polymers, thereby reducing the particle size of carbon black in the high-voltage shielded cable material, and thus reducing or eliminating needle-like protrusions on the surface of the shielding layer of the high-voltage cable, reducing the phenomenon of excessive local heating of the high-voltage cable, and solving or improving the problem that high-voltage shielded cables are prone to breakdown.

[0041] Furthermore, the slurry after mixing carbon black with solvent is injected into the polymer melt that is being plasticized through the first feed port 11. This is equivalent to introducing pre-lubricated and pre-dispersed carbon black into the polymer matrix. The particle size of the carbon black is reduced from the micron level to the nano level, which significantly reduces the frictional resistance and dispersion load that the screw of the extruder 1 needs to overcome in the solid conveying and melting sections, improves energy utilization efficiency, reduces wear on the screw and barrel, and avoids local overheating and polymer degradation caused by directly adding dry carbon black, which leads to material embrittlement, shortens the service life of the shielding layer, and easily causes processing scorching in the extruder 1, reducing production continuity.

[0042] Meanwhile, the mixed carbon black slurry is a fluid with controllable viscosity. Compared with dry carbon black powder, it can be continuously, stably, and without pulsation conveyed through pumps and pipelines, providing constant feed for extruder 1. This avoids problems such as "bridging" and "pulsation" that are prone to occur when feeding dry powder, and greatly improves the stability and continuity of the production process.

[0043] In one embodiment, such as Figure 1As shown, the first feed port 11 is located in the middle of the extruder 1. Specifically, the first feed port 11 is opened at the end of the melting section of the barrel of the extruder 1 or at the beginning of the melt pumping section. Here, the polymer has basically completed plasticization, forming a continuous and viscous melt, but the temperature has not yet reached the highest point, and the melt viscosity is still maintained at a certain level, with good encapsulation and mixing capabilities.

[0044] In this embodiment, such as Figure 1 As shown, the first feed port 11 is located in the middle of the extruder 1. Carbon black slurry is introduced after the polymer is completely melted. This avoids the additional dust and uneven feeding caused by the friction between carbon black and solid polymer particles in the solid conveying section. It also avoids the structural damage that may occur when carbon black is subjected to excessive local shear heat in the early stage of the melting section.

[0045] Furthermore, the melt at this location has suitable viscosity and temperature, which can effectively wet and capture particles in the carbon black slurry, and provide sufficient shear stress to complete the final fine dispersion. The solvent in the slurry evaporates (or is absorbed) rapidly after contacting the high-temperature melt, and the carbon black particles are "fixed" in the melt network, which can improve the uniformity and stability of carbon black distribution.

[0046] From the middle of the extruder 1 to the die head outlet, there is still a sufficiently long screw length (usually accounting for 40% to 50% of the total length) for distributed mixing, dispersion mixing and devolatilization (solvent or low molecular weight volatiles) of carbon black particles, ensuring the final dispersion quality.

[0047] Meanwhile, polymer base materials and other solid additives (such as antioxidants) are added from the second feed port 12 at the head of the extruder 1. By placing the carbon black slurry inlet in the middle, functional zoning is achieved, preventing interference between different parts and protecting the main feeding system from carbon black contamination.

[0048] In one embodiment, such as Figure 1 As shown, the liquid-solid mixing vessel 2 is equipped with an ultrasonic generator and a stirring assembly. Specifically, the stirring assembly uses a multi-layered composite impeller. For example, the bottom layer consists of turbine or ribbon impellers for powerful conveying and macroscopic mixing, while the middle and upper layers consist of serrated or dispersive disc impellers (stator-rotor structure) to provide high shear force and break up carbon black agglomerates. The stirring shaft is equipped with a mechanical seal to prevent solvent evaporation and air ingress. The drive motor 8 is a variable frequency motor 8, which can steplessly adjust the speed to adapt to different formulations and process stages.

[0049] The ultrasonic generator is an existing product and can be purchased on the market. It is integrated into the liquid-solid mixing vessel 2. It can be an immersion type, where multiple ultrasonic transducers with amplitude transformers are sealed via flanges and directly inserted into the slurry inside the vessel, arranged in an array to ensure a uniform sound field. Alternatively, it can be a jacketed type, where the ultrasonic transducers are coupled to the outer wall or bottom of the vessel, transmitting ultrasonic energy to the internal material through the vessel wall (suitable for situations with extremely high sealing requirements or where the material is corrosive).

[0050] In this embodiment, such as Figure 1 As shown, an ultrasonic generator and a stirring assembly are installed inside the liquid-solid mixing vessel 2. When the ultrasonic waves propagate in the liquid medium, they generate alternating high-pressure and low-pressure cycles. In the low-pressure stage, tiny vacuum bubbles (cavitation nuclei) form in the liquid; in the high-pressure stage, these bubbles are rapidly compressed and implode, instantly generating local pressure, as well as strong shock waves and microjets. These can penetrate the interior of carbon black agglomerates, completely tearing them into smaller units or even primary particles, thereby improving the mixing uniformity of carbon black and solvent.

[0051] Meanwhile, ultrasonic dispersion and mechanical shearing within the vessel create a perfect synergy between macroscopic convection mixing and microscopic forced dispersion. Mechanical stirring is responsible for the overall circulation and initial crushing of the material, while ultrasound is responsible for targeted removal of the most stubborn agglomerates, resulting in the carbon black dispersion uniformity in the final output slurry reaching the nanoscale or approaching the level of primary particles.

[0052] In one embodiment, the frequency range of the ultrasonic generating component is 20kHz to 40kHz. Specifically, the frequency of the ultrasonic generating component is any one or any two values ​​among 20kHz, 21kHz, 22kHz, 23kHz, 24kHz, 25kHz, 26kHz, 27kHz, 28kHz, 29kHz, 30kHz, 31kHz, 32kHz, 33kHz, 34kHz, 35kHz, 36kHz, 37kHz, 38kHz, 39kHz, and 40kHz. In this embodiment, the frequency range of the ultrasonic generating component is 20kHz to 40kHz, and the cavitation effect of carbon black and solvent is significant, which can improve the mixing uniformity of carbon black and solvent.

[0053] In one embodiment, the ratio of the injection volume velocity of the liquid inlet 21 to the injection volume velocity of the solid inlet 22 is not less than 4. Specifically, the liquid inlet 21 is equipped with a high-precision volumetric flow meter 3 (such as an elliptical gear flow meter 3 or a mass flow meter 3) and a servo-controlled metering pump to monitor and adjust the injection rate in real time. The solid inlet 22 is equipped with a loss-in-weight feeding system, whose controller can calculate and output the mass flow rate in real time. The density of the material can be converted into volumetric flow rate. The central control system (such as a PLC or DCS) receives signals from the flow meter 3 and the loss-in-weight scale 5, calculates the liquid-solid volumetric velocity ratio in real time, and adjusts the pump speed or feeder speed through feedback to dynamically stabilize the ratio at a set value of not less than 4.

[0054] It should be noted that the injection volume rate refers to the volume injected into the liquid-solid mixing vessel 2 per unit time.

[0055] In this embodiment, the ratio of the injection volume velocity of the liquid injection port 21 to the injection volume velocity of the solid injection port 22 is not less than 4. The high proportion of solvent provides sufficient free fluid medium for the carbon black particles, ensuring that each carbon black particle or small agglomerate can be fully surrounded and wetted by solvent molecules, minimizing the probability of direct contact between particles, thereby reducing the particle size of the carbon black particles and further reducing the smoothness of the shielding layer of the high-voltage shielded cable produced from the high-voltage shielded cable material.

[0056] In one embodiment, the extruder 1 is a twin-screw extruder 1 with a length-to-diameter ratio of not less than 40. In this embodiment, the twin-screw extruder 1 has excellent mixing and self-cleaning capabilities. The material in its meshing zone is subjected to strong shearing, compression and exchange, and the mixing efficiency is much higher than that of a single screw. The mutually wiping threads have a self-cleaning effect, preventing material retention and degradation. It can also adapt to various feeding methods and has strong adaptability to viscous fluids such as slurries, making it easy to achieve stable intake and mixing.

[0057] The extruder 1 has an aspect ratio of not less than 40. The longer mixing path allows the carbon black particles to undergo more shearing and segmentation, resulting in a more uniform distribution. At the same time, a large aspect ratio means that the same dispersion effect can be achieved at a gentler shear rate, which helps to reduce local overheating and excessive shear degradation of polymer molecular chains.

[0058] In one embodiment, the mixing outlet 23 of the liquid-solid mixing vessel 2 is connected to the first feed port 11 via a flow meter 3. Specifically, the flow meter 3 is preferably a Coriolis mass flow meter 3, because it can simultaneously, directly, and with high precision measure the mass flow rate, density, and temperature of the slurry, and is unaffected by changes in slurry viscosity and flow regime. The signal from the flow meter 3 is connected to the control system and linked with the speed of the extruder 1 or downstream demand to achieve closed-loop control.

[0059] In this embodiment, the content (concentration) of carbon black in the final product is a core parameter affecting key performance characteristics such as the volume resistivity and strength of the shielding layer. By monitoring and controlling the slurry flow rate entering extruder 1 in real time, combined with the known slurry formulation concentration, the addition ratio of carbon black in the final cable material can be controlled with extreme precision, ensuring high consistency between batches.

[0060] In one embodiment, multiple heating sleeves are sequentially arranged inside the extruder 1 along the extrusion direction. The temperature control range of the heating sleeves is 60°C to 180°C. Specifically, the heating sleeves are typically cast aluminum or cast copper heaters with embedded high-performance resistance wires, providing fast heat conduction and uniform temperature. High-end equipment uses electromagnetic induction heating, which is more efficient and has a faster response.

[0061] In this embodiment, multiple heating sleeves are sequentially arranged along the extrusion direction inside the extruder 1. Different polymers and carbon black varieties are sensitive to temperature. Multi-segment temperature control ensures sufficient melting and dispersion while minimizing the thermal oxidative degradation of polymers and the thermal damage to the carbon black structure. This is crucial for maintaining the long-term electrical and mechanical properties of the material. Zoned heating can provide heat only to the required sections, avoiding the energy waste caused by traditional overall heating. At the same time, the cooling system can respond quickly to prevent overheating, achieving a balance between energy saving and process precision.

[0062] In one embodiment, such as Figure 1 As shown, the high-voltage shielded cable material production device also includes multiple conveying devices 4, and the extruder 1 also includes a second feeding port 12. The output ports of the multiple conveying devices 4 are all connected to the second feeding port 12, and each conveying device 4 has a loss-in-weight scale 5 at its input port. Specifically, the second feeding port 12 is located at the head (upstream) of the extruder 1 and is usually equipped with a multi-way feed hopper, which is connected to the upstream equipment through pneumatic conveying or spiral conveying pipelines. A loss-in-weight scale 5 is installed at the input port of each conveying device 4.

[0063] The loss-in-weight scale 5 consists of a weighing hopper, a high-precision load cell (strain gauge type), a feeder (usually a single or twin screw), and a controller. It calculates and controls the instantaneous feed rate by monitoring the rate of weight loss in the hopper in real time.

[0064] In this embodiment, such as Figure 1 As shown, by adding the base resin and solid additives from the second feed port 12 and the carbon black slurry from the first feed port 11 (middle), the step-by-step and zone-by-zone addition is achieved, and each component enters at the most suitable stage, resulting in the best mixing effect.

[0065] In one embodiment, such as Figure 1As shown, the high-voltage shielded cable material production device also includes a vacuum pump 6. A vacuum exhaust port 13 is provided at the tail end of the extruder 1 along the extrusion direction. The input end of the vacuum pump 6 is connected to the vacuum exhaust port 13. Specifically, the vacuum exhaust port 13 is opened above the barrel at the tail end (usually the devolatilization section) of the extruder 1, connected to a vacuum buffer tank and a condenser. Finally, a liquid ring vacuum pump 6 or a dry screw vacuum pump 6 is used to evacuate the vacuum. The inner wall of the barrel at the exhaust port can be designed with slots or equipped with barrier elements to increase the melt surface area and prevent it from being drawn away.

[0066] In this embodiment, such as Figure 1 As shown, the solvent from the carbon black slurry, residual monomers in the polymer, oligomers, and small molecules generated during processing are all volatiles. If they remain in the final product, they will be slowly released when the cable heats up during operation, forming microbubbles, reducing insulation strength, or directly causing blistering and cracking of the shielding layer. A vacuum exhaust port 13 is installed at the tail of the screw, at which point the material is highly mixed and at its optimal viscosity. Under high vacuum, the small molecules in the melt escape with low resistance, resulting in extremely high removal efficiency. This improves the dielectric properties, aging resistance, and long-term reliability of the product, eliminating early failures caused by internal volatiles.

[0067] Example 1 Carbon black and xylene are mixed at a ratio of 20% and injected into the liquid-solid mixing vessel 2. The mixture is thoroughly mixed using a liquid-solid mixer with ultrasonic vibration. The mixture is then injected into the second to fourth sections of the extruder 1 using a flow meter 3, so that the carbon black and resin base are fully mixed. The xylene solvent is evaporated from the vacuum port at the second to third section of the cylinder in front of the extruder 1, producing high-voltage shielded cable material.

[0068] Example 2 The difference between this embodiment and Embodiment 1 is that the ratio of carbon black to xylene is 25%.

[0069] Example 3 The difference between this embodiment and Embodiment 1 is that the ratio of carbon black to xylene is 30%.

[0070] Comparative Example In this embodiment, carbon black is directly injected into the second feed port 12 for mixing and extrusion.

[0071] Test method: Narrow strip extrusion test, narrow strip thickness 550±10um, number of protrusions: units / m 2 The test results are shown in Table 1. It should be noted that three samples were tested in each embodiment. In Table 1, >25um, >50um, >75um, and >100um are the heights of the protrusions.

[0072] Table 1

[0073] Analysis of Table 1 shows that by premixing carbon black with solvent, the number of surface protrusions of the ultra-narrow strip is reduced by at least 90% compared to the number of ultra-narrow strips produced by directly adding carbon black into the second feed port 12. Furthermore, when the volume ratio of carbon black to solvent is below 25%, surface protrusions no longer occur.

[0074] According to an embodiment of this application, another aspect provides a production line body, including the high-voltage shielded cable material production apparatus of any of the above embodiments.

[0075] Specifically, the production line is for producing high-voltage shielded cables.

[0076] In this embodiment, since the production line includes a high-voltage shielded cable material production device, which has the same technical effect as the high-voltage shielded cable material production device, it will not be described in detail here.

[0077] In summary, the shielded cable material production apparatus provided in this application fully mixes carbon black and solvent in an ultrasonic mixing vessel, thereby increasing the dispersibility of carbon black, reducing the surface protrusion height of the shielding layer to below 25μm, and reducing the volume resistivity fluctuation range to ±10%, which is significantly better than the industry standard. At the same time, the integrated design shortens the production cycle by 35%, reduces unit energy consumption by 22%, and reduces the overall production cost by 18%.

[0078] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A high-voltage shielded cable material production apparatus, characterized in that, include: The extruder (1) has a first feed port (11); The liquid-solid mixing vessel (2) has a liquid inlet (21), a solid inlet (22) and a mixing outlet (23). The mixing outlet (23) is connected to the first feeding port (11). The solid inlet (22) is used to add carbon black, and the liquid inlet (21) is used to add carbon black solvent.

2. The high-voltage shielded cable material production apparatus according to claim 1, characterized in that, The first feed port (11) is located in the middle of the extruder (1).

3. The high-voltage shielded cable material production apparatus according to claim 1, characterized in that, The liquid-solid mixing vessel (2) is equipped with an ultrasonic generator and a stirring assembly.

4. The high-voltage shielded cable material production apparatus according to claim 3, characterized in that, The frequency range of the ultrasonic generator component is 20kHz to 40kHz.

5. The high-voltage shielded cable material production apparatus according to any one of claims 1 to 4, characterized in that, The ratio of the injection volume velocity of the liquid injection port (21) to the injection volume velocity of the solid injection port (22) is not less than 4.

6. The high-voltage shielded cable material production apparatus according to any one of claims 1 to 4, characterized in that, The extruder (1) is a twin-screw extruder (1), and the length-to-diameter ratio of the extruder (1) is not less than 40.

7. The high-voltage shielded cable material production apparatus according to any one of claims 1 to 4, characterized in that, The mixing outlet (23) of the liquid-solid mixing vessel (2) is connected to the first feeding port (11) via a flow meter (3).

8. The high-voltage shielded cable material production apparatus according to any one of claims 1 to 4, characterized in that, The extruder (1) has multiple heating sleeves arranged sequentially along the extrusion direction, and the temperature control range of the heating sleeves is 60°C to 180°C.

9. The high-voltage shielded cable material production apparatus according to any one of claims 1 to 4, characterized in that, It also includes multiple conveying devices (4), the extruder (1) further includes a second feeding port (12), the output ports of the multiple conveying devices (4) are all connected to the second feeding port (12), and each of the conveying devices (4) is equipped with a loss-in-weight scale (5) at its input port. It also includes a vacuum pump (6), and the extruder (1) is provided with a vacuum exhaust port (13) at the tail end along the extrusion direction. The input end of the vacuum pump (6) is connected to the vacuum exhaust port (13).

10. A production line body, characterized in that, include: The high-voltage shielded cable material production apparatus as described in any one of claims 1 to 9.

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