Main cable super-toughness fireproof coating based on short fibers, preparation equipment and preparation method

Abstract

The invention discloses a main cable super-toughness fireproof coating based on short fibers, a preparation device and a preparation method, the fireproof coating is a two-component system and comprises a component A and a component B curing agent, the component A comprises the following raw materials in parts by weight: 30-50 parts of epoxy resin, 25-40 parts of a composite flame-retardant system, 5-15 parts of hydrophobic silicon dioxide aerogel powder, 3-8 parts of chopped fibers, 2-5 parts of an auxiliary agent, 5-10 parts of a pigment filler and 10-20 parts of a solvent. According to the invention, through innovative compounding of an epoxy expansion system, nano aerogel and chopped fibers, a multiple synergistic fireproof mechanism of expansion barrier, nano heat insulation and reflection radiation is created, so that the heat insulation efficiency and quality of an expanded carbon layer are fundamentally improved, and the fire endurance is remarkably prolonged; meanwhile, excellent toughness and cracking resistance are provided for the coating through a three-dimensional distributed short fiber network, so that the coating can adapt to deformation of a base material and resist impact, the lasting and firm adhesive force between the coating and the base material is ensured, and the service life of the coating in a severe environment is greatly prolonged.

Description

Technical Field

[0001] This invention belongs to the field of fire-retardant coating technology, specifically relating to a short-fiber main cable ultra-tough fire-retardant coating, preparation equipment, and preparation method. Background Technology

[0002] The main cable of a suspension bridge is its lifeline, and its safety is paramount. Fire is one of the major hazards threatening bridge safety. Steel's strength decreases dramatically at high temperatures, and if the main cable is exposed to fire, it could lead to catastrophic consequences. Therefore, fire protection for the main cable is extremely important.

[0003] Currently, commonly used fire-retardant coatings for main cables mainly include intumescent fire-retardant coatings and non-intumescent fire-retardant coatings (such as cement-based thick coatings). Non-intumescent coatings are thick, have poor adhesion, and are prone to cracking and peeling. Traditional epoxy-based intumescent fire-retardant coatings, although having good adhesion, have the following drawbacks: Poor quality charcoal layer: The charcoal layer formed after being fired is loose and prone to cracking, and cannot effectively block the heat from being transferred to the substrate.

[0004] Insufficient toughness: The main cable will undergo micro-deformation under wind load and temperature changes, and the rigid coating layer is prone to micro-cracks that can propagate, leading to protection failure.

[0005] Limited thermal insulation efficiency: Traditional fillers have an upper limit to their thermal insulation performance, making it difficult to achieve long-term thermal insulation with a thinner coating thickness.

[0006] Aerogels, as a type of nanoporous super insulating material, can theoretically greatly improve the thermal insulation of coatings. However, they are brittle and prone to powdering, and adding them directly to coatings will severely damage the mechanical properties of the coating (such as adhesion and impact resistance), making them difficult to apply in practical engineering.

[0007] Therefore, developing a fireproof coating and supporting process that can both leverage the ultimate thermal insulation properties of aerogels and ensure that the coating has excellent toughness and stability is a technical challenge that urgently needs to be solved in this field.

[0008] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0009] The purpose of this invention is to provide a short fiber-based ultra-tough fireproof coating for main cables, preparation equipment and preparation method, which can provide a tough fireproof coating with excellent comprehensive performance for bridge main cables. The coating integrates a highly efficient intumescent flame retardant system, nano heat insulation unit and fiber toughening network, and can form a tough, dense and highly heat-insulating char layer when exposed to fire.

[0010] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution: The main cable ultra-tough fireproof coating based on short fibers is a two-component system, including component A and component B curing agent. Component A includes the following raw materials in parts by weight: 30-50 parts epoxy resin, 25-40 parts composite flame retardant system, 5-15 parts hydrophobic silica aerogel powder, 3-8 parts chopped fibers, 2-5 parts additives, 5-10 parts pigments and fillers, and 10-20 parts solvent; the length of the chopped fibers is 50-200 μm.

[0011] In one or more embodiments of the present invention, the chopped fibers are selected from one or more of basalt fibers, aramid fibers, or glass fibers.

[0012] In one or more embodiments of the present invention, the pore size of the hydrophobic silica aerogel powder is less than 70 nanometers.

[0013] The equipment for preparing a short-fiber-based ultra-tough fire-retardant coating for main cables includes a mixing mechanism, a fiber dispersion mechanism, a peeling mechanism, and a control system. The mixing mechanism includes an outer shell, an inner shell, a mounting cover, and a mixing and dispersion assembly. The inner shell is integrally formed inside the outer shell to form a sandwiched processing chamber. The mounting cover is installed on the top of the processing chamber. The mixing and dispersion assembly is installed inside the processing chamber for mixing and dispersing the materials. The fiber dispersion mechanism is installed on the mounting cover and is used to disperse the short-cut fibers and feed them into the processing chamber. The peeling mechanism is connected to the processing chamber through a circulation pipeline to form a circulation loop for processing nanosheet materials. The control system includes a control unit and a viscosity monitoring unit.

[0014] In one or more embodiments of the present invention, the mixing and dispersing assembly includes a planetary gearbox, a mounting hole, a hollow output shaft, a frame-type stirring rod, a first scraper, a second scraper, a dispersing plate, a dispersing disc, a guide plate, a first servo motor, and a main drive motor. The planetary gearbox is mounted on a mounting cover, and the mounting hole is coaxially formed on the mounting cover. The hollow output shaft is driven to rotate by a driving component inside the planetary gearbox. The main drive motor is mounted on the side wall of the planetary gearbox to drive the driving component to rotate. The hollow output shaft coaxially passes through the mounting hole and is placed in the processing area. Inside the chamber, the centerline of the upper wall panel of the frame-type stirring rod is fixedly connected to the bottom of the hollow output shaft in a coaxial manner. The first scraper is fixedly connected in pairs to the outer walls of the left and right vertical plates of the frame-type stirring rod. The second scraper is provided in pairs and is fixedly connected to the bottom of the left and right vertical plates of the frame-type stirring rod. Multiple dispersing plates are provided and are fixedly connected to the inner walls of the left and right vertical plates of the frame-type stirring rod at equal intervals. The multiple dispersing plates on the inner walls of the left and right vertical plates of the frame-type stirring rod are inclined in opposite directions.

[0015] In one or more embodiments of the present invention, the rotating shaft passes coaxially through the top wall of the planetary gearbox, the hollow output shaft, and the frame stirring rod, and extends to a position near the bottom of the processing chamber. The rotating shaft is rotatably mounted on the top wall of the planetary gearbox and the frame stirring rod. The first servo motor is mounted above the rotating shaft. Multiple dispersion discs are provided and fixedly connected to the side wall of the rotating shaft below the frame stirring rod at equal intervals. Multiple guide plates are provided and fixedly connected at equal intervals on the upper surface of the edges of the multiple dispersion discs. The multiple dispersion discs are all inclined on the guide plates, and the inclination directions of the guide plates on adjacent layers of dispersion discs are opposite.

[0016] In one or more embodiments of the present invention, the mixing mechanism further includes a feed pipe, a discharge pipe, a circulation pipe, a liquid inlet pipe, and a liquid outlet pipe. The feed pipe is mounted on the planetary gearbox, the discharge pipe is mounted on the bottom wall of the processing chamber, the circulation pipe is mounted on the side wall of the discharge pipe, the liquid inlet pipe is mounted on the side wall of the outer casing at the top position, and the liquid outlet pipe is mounted on the bottom side wall of the outer casing.

[0017] In one or more embodiments of the present invention, the fiber dispersion mechanism includes a Venturi tube, a first air inlet pipe, a fiber conveying pipe, a cyclone disperser, a connecting flange, a feed plate, a first tangential air inlet, a second tangential air inlet, a secondary air ring, a second air inlet pipe, and a discharge pipe. The first air inlet pipe is installed on the top wall plate of the Venturi tube, the fiber conveying pipe is installed on the side wall of the throat pipe of the Venturi tube, the cyclone disperser is installed at the bottom of the Venturi tube, and the cyclone disperser and the Venturi tube are connected together by a connecting flange. The feed plate is integrally formed at the upper port of the cyclone disperser, and the first tangential air inlet is opened in a manner parallel to the horizontal plane. The second tangential air inlet is located on the side wall of the feed plate and is opened at an angle of 30-45 degrees to the horizontal plane on the bottom wall of the feed plate. The secondary air ring is fixedly connected to the bottom of the outlet end of the cyclone disperser. Multiple nozzles are provided and are opened at equal intervals in an inclined manner on the side wall of the inner ring of the secondary air ring. The second air inlet pipe is fixedly connected to the side wall of the outer ring of the secondary air ring. The discharge pipe is fixedly connected to the bottom of the secondary air ring and is fixedly connected to the mounting cover in a through manner. The outlet end of the discharge pipe is inclined towards the inner side wall of the inner shell. Wear-resistant liners are provided inside the venturi tube and the cyclone disperser.

[0018] In one or more embodiments of the present invention, the stripping mechanism includes a stator, a spiral microgroove, a rotor, a material conveying gap, a material conveying housing, a sealing ring, a feeding pipe, a collecting hood, a return pipe, a drive shaft, and a second servo motor. The stator has an internal conical cavity. The rotor is rotatably connected to the internal cavity of the stator in a coaxial manner. A spiral microgroove is formed on the inner sidewall of the stator, and the spiral direction of the microgroove is opposite to the rotation direction of the rotor. The material conveying gap is formed between the inner sidewall of the stator and the outer sidewall of the spiral microgroove, and the width of the material conveying gap gradually narrows from top to bottom. A material conveying housing is installed at the upper end of the material conveying gap above the stator and rotor. The sealing ring is located at the connection between the material conveying housing and the rotor. The feeding pipe is installed on the top wall of the material conveying housing. The conveying pump is installed at the end of the feeding pipe away from the material conveying housing. The end of the circulating material pipe away from the discharge pipe is installed at the inlet of the conveying pump. The material collecting hood is installed at the bottom of the stator. The return pipe is installed at the bottom of the material collecting hood. The end of the return pipe away from the material collecting hood is installed on the side wall of the feeding pipe. The drive shaft is coaxially fixedly connected to the rotor. The second servo motor is installed on the drive shaft.

[0019] The preparation method of the short fiber-based ultra-tough fire-retardant coating for main cables includes the following steps: S1. Material premixing: Add a portion of epoxy resin, solvent and additives to the processing chamber, and start the mixing and dispersing components to mix at low speed; S2, Dispersing flame retardant system and aerogel: Add composite flame retardant system and hydrophobic silica aerogel powder to the processing chamber, switch the mixing and dispersing component to high-speed rotation mode for dispersion until the material fineness is qualified; S3. Individualized fiber dispersion and addition: Start the fiber dispersion mechanism to form an aerosol in the Venturi tube by compressed air, and then inject it into the cyclone disperser through the first tangential air inlet and the second tangential air inlet in a double tangential orthogonal inlet tangential manner for dispersion. Then, the dispersed fiber is sprayed into the paint slurry in the processing chamber. S4. Nanosheet peeling and addition: The material and solvent in the processing chamber are pumped into the peeling mechanism for circulation. The laminar shear force generated by the conical feeding gap between the stator and rotor is used to peel the nanosheets. After being prepared into a pregel, it is transported back to the processing chamber. S5. Final blending: Add the remaining epoxy resin to the processing chamber, switch the mixing and dispersing components to low-speed stirring mode for blending, and after vacuum degassing, obtain component A of the fire-retardant coating; S6. Packaging: Disassemble the A component and the B component curing agent into separate packages.

[0020] Compared with the prior art, the present invention has the following advantages: 1. This invention creates a multi-synergistic fireproof mechanism of expansion barrier, nano-thermal insulation and radiation reflection through the innovative combination of epoxy expansion system, nano-aerogel and short-cut fiber, which fundamentally improves the thermal insulation efficiency and quality of the expanded carbon layer, thereby significantly extending the fire resistance limit. 2. The present invention provides the coating with excellent toughness and crack resistance through a three-dimensionally distributed short fiber network, enabling it to adapt to the deformation of the substrate and resist impact, while ensuring a long-lasting and strong adhesion between the coating and the substrate, and greatly improving its service life under long-term vibration and harsh environment. 3. The specialized equipment and process provided by this invention successfully solves industry bottlenecks such as the fragility of aerogels and the tendency of chopped fibers to agglomerate, allowing their functions to be fully utilized; at the same time, the application of hydrophobic aerogels effectively avoids performance degradation of the coating due to moisture absorption, ensuring long-term stability of the protective effect. 4. The special equipment provided by this invention fundamentally solves the problem of dispersing nano and micro materials in coatings through the synergistic effect of its core components. The mixing mechanism achieves gentle dispersion of aerogels and avoids structural breakage; the fiber dispersion mechanism ensures the monofilamentization and uniform addition of fibers; and the material stripping mechanism efficiently strips nanosheets to restore their functionality, so that the prepared fire-retardant coating has excellent fire resistance, mechanical properties and batch-to-batch stability. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a front view of a device for preparing a short-fiber main cable ultra-tough fire-retardant coating according to an embodiment of the present invention; Figure 2 This is a perspective view of a device for preparing a short-fiber main cable ultra-tough fire-retardant coating according to an embodiment of the present invention; Figure 3 This is a cross-sectional view of a device for preparing a short-fiber main cable ultra-tough fire-retardant coating according to an embodiment of the present invention; Figure 4 This is a cross-sectional view of a device for preparing a short-fiber main cable ultra-tough fireproof coating according to an embodiment of the present invention; Figure 5 For the present invention Figure 4 A schematic diagram at point A in the middle; Figure 6 For the present invention Figure 4 A schematic diagram at point B in the middle; Figure 7 For the present invention Figure 4 A schematic diagram at point C in the middle; Figure 8 This is a schematic diagram of the dispersion disk in this invention; Figure 9 This is a cross-sectional view of the fiber dispersion mechanism in this invention; Figure 10 This is a cross-sectional view of the material stripping mechanism in this invention.

[0023] Explanation of key figure labels: 1-Mixing mechanism, 11-Outer shell, 12-Inner shell, 13-Mounting cover, 14-Planetary gearbox, 15-Mounting hole, 16-Hollow output shaft, 17-Frame stirring rod, 18-First scraper, 19-Second scraper, 110-Dispersion plate, 111-Rotating shaft, 112-Dispersion disc, 113-Guide plate, 114-First servo motor, 115-Feed pipe, 116-Discharge pipe, 117-Circulating pipe, 118-Liquid inlet pipe, 119-Liquid outlet pipe, 120-Main drive motor, 2-Fiber dispersion mechanism, 21-Venturi tube, 22-The 1. Inlet pipe, 23. Fiber conveying pipe, 24. Cyclone disperser, 25. Connecting flange, 26. Feed plate, 27. First tangential air inlet, 28. Second tangential air inlet, 29. Secondary air ring, 210. Nozzle, 211. Second air inlet pipe, 212. Discharge pipe, 3. Stripping mechanism, 31. Stator, 32. Spiral microgroove, 33. Rotor, 34. Feeding gap, 35. Feeding housing, 36. Sealing ring, 37. Feeding pipe, 38. Collection hood, 39. Return pipe, 310. Drive shaft, 311. Second servo motor, 312. Conveying pump. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0025] The short-fiber-based ultra-tough fireproof coating for main cables in one embodiment of the present invention is a two-component system, including component A and component B curing agent. Component A includes the following raw materials in parts by weight: 30-50 parts epoxy resin, 25-40 parts composite flame retardant system, 5-15 parts hydrophobic silica aerogel powder, 3-8 parts chopped fibers, 2-5 parts additives, 5-10 parts pigments and fillers, and 10-20 parts solvent; the length of the chopped fibers is 50-200 μm.

[0026] Specifically, epoxy resin serves as the film-forming agent and char source; the composite flame-retardant system includes acid sources such as ammonium polyphosphate, char sources, and gas sources, with acid sources such as ammonium polyphosphate, char sources such as pentaerythritol, and gas sources such as melamine; hydrophobic silica aerogel powder serves as the core thermal insulation component; chopped fibers serve as the toughening and reinforcing component; additives include wetting and dispersing agents, defoamers, and leveling agents; and solvents are used to adjust viscosity. Component B is a curing agent that matches the epoxy resin in component A, such as a polyamide curing agent or a modified amine curing agent.

[0027] This fire-retardant coating creatively combines an epoxy intumescent flame-retardant system, nano-aerogel, and short fibers. When exposed to fire, the flame-retardant system foams and expands to form a char layer; the aerogel particles are evenly distributed in the char layer, and their nanoscale pores can almost "lock" in air convection heat transfer and significantly suppress radiative heat transfer, greatly improving the thermal insulation efficiency of the char layer; the short fibers form a three-dimensional network in the original coating and the expanded char layer, bridging cracks like "steel bars," significantly enhancing the coating's toughness, crack resistance, and overall stability, preventing the char layer from collapsing under flame impact.

[0028] Meanwhile, the materials were selected specifically: hydrophobic aerogels were chosen to avoid the problem of coating deterioration caused by moisture absorption of hydrophilic aerogels; and high-strength and high-temperature resistant short-cut fibers were chosen to ensure that they could still maintain their reinforcing effect in the flame.

[0029] Optionally, the chopped fibers are selected from one or more of basalt fibers, aramid fibers, or glass fibers.

[0030] Preferably, the pore size of the hydrophobic silica aerogel powder is less than 70 nanometers.

[0031] It should be noted that component B, the curing agent, is generally considered a conventional, mature commercial product in this solution. It can be directly purchased or prepared using traditional methods without significant modifications, and therefore will not be elaborated upon here. Its sole purpose is to mix with the innovative component A during application and trigger its curing into a high-performance coating.

[0032] like Figures 1-4 As shown, another embodiment of the present invention discloses a preparation device for a short-fiber main cable ultra-tough fire-retardant coating, comprising a mixing mechanism 1, a fiber dispersion mechanism 2, a peeling mechanism 3, and a control system. The mixing mechanism 1 includes an outer shell 11, an inner shell 12, a mounting cover 13, and a mixing and dispersion assembly. The inner shell 12 is integrally formed inside the outer shell 11 to form a sandwich processing chamber. The mounting cover 13 is installed on the top of the processing chamber. The mixing and dispersion assembly is installed in the processing chamber for mixing and dispersing the materials. The fiber dispersion mechanism 2 is installed on the mounting cover 13 and is used to disperse the short-cut fibers and send them into the processing chamber. The peeling mechanism 3 is connected to the processing chamber through a circulation pipeline to form a circulation loop for processing the nanosheet material. The control system includes a control unit and a viscosity monitoring unit.

[0033] When using the equipment for preparing tough fire-retardant coatings for bridge main cables, a portion of epoxy resin, solvent, and additives are added to the processing chamber, and the mixing and dispersion component is started for low-speed stirring and mixing. Then, a composite flame-retardant system and hydrophobic silica aerogel powder are added to the processing chamber, and the mixing and dispersion component is switched to high-speed rotation mode for dispersion until the material fineness is qualified. The fiber dispersion mechanism 2 is started, and the short-cut fibers are formed into an aerosol in the Venturi tube 21 by compressed air, and then passed through the first tangential air inlet 27 and the second tangential air inlet 28 for double cutting. The nanosheets are dispersed by injecting the slurry into the cyclone disperser 24 in an orthogonal inlet tangential manner. The dispersed fibers are then sprayed into the paint slurry in the processing chamber. The materials and solvent in the processing chamber are pumped into the peeling mechanism 3 for circulation. The laminar shear force generated by the conical feeding gap 34 between the stator 31 and the rotor 33 is used to peel off the nanosheets. After pregelation, the nanosheets are transported back to the processing chamber. The remaining epoxy resin is added to the processing chamber, and the mixing and dispersion components are switched to a low-speed stirring mode for blending. After vacuum degassing, component A of the fire-retardant coating is obtained.

[0034] like Figures 1-4 as well as Figure 8 As shown, the mixing and dispersing assembly includes a planetary gearbox 14, a mounting hole 15, a hollow output shaft 16, a frame-type stirring rod 17, a first scraper 18, a second scraper 19, a dispersing plate 110, a dispersing disk 112, a guide plate 113, a first servo motor 114, and a main drive motor 120. The planetary gearbox 14 is mounted on a mounting cover 13, and the mounting hole 15 is coaxially formed on the mounting cover 13. The hollow output shaft 16 is driven to rotate by a driving component inside the planetary gearbox 14. The main drive motor 120 is mounted on the side wall of the planetary gearbox 14 to drive the driving component to rotate. The hollow output shaft 16 coaxially passes through the mounting hole 17. 5. The frame stirring rod 17 is placed in the processing chamber. The center line of the upper wall plate of the frame stirring rod 17 is fixedly connected to the bottom of the hollow output shaft 16 in a coaxial manner. The first scraper 18 is fixedly connected to the outer wall of the left and right vertical plates of the frame stirring rod 17 in pairs. The second scraper 19 is provided in pairs and is fixedly connected to the bottom of the left and right vertical plates of the frame stirring rod 17. Multiple dispersing plates 110 are provided and are fixedly connected to the inner wall of the left and right vertical plates of the frame stirring rod 17 in an equally spaced manner. The multiple dispersing plates 110 on the inner wall of the left and right vertical plates of the frame stirring rod 17 are inclined in opposite directions.

[0035] Specifically, the rotation of the main drive motor 120 drives the drive component to rotate, which in turn drives the hollow output shaft 16 to rotate. The hollow output shaft 16 then drives the frame-type stirring rod 17 to rotate, which in turn drives the first scraper 18 and the second scraper 19 to rotate. When the first scraper 18 and the second scraper 19 rotate, they can scrape and clean the material adhering to the inner wall of the inner shell 12, thereby achieving mixing and dispersion of the material while avoiding material adhesion. At the same time, a certain distance is provided between the first scraper 18 and the second scraper 19 and the inner wall of the inner shell 12, so as to scrape off the material adhering to the inner wall while avoiding direct contact.

[0036] like Figure 4 , Figure 5 and Figure 8 As shown, the rotating shaft 111 passes through the top wall of the planetary gearbox 14, the hollow output shaft 16, and the frame stirring rod 17 in a coaxial manner and extends to a position near the bottom of the processing chamber. The rotating shaft 111 is rotatably mounted on the top wall of the planetary gearbox 14 and the frame stirring rod 17. The first servo motor 114 is mounted above the rotating shaft 111. Multiple dispersion discs 112 are provided and are fixedly connected to the side wall of the rotating shaft 111 below the frame stirring rod 17 at equal intervals. Multiple guide plates 113 are provided and are fixedly connected at equal intervals on the upper surface of the edges of multiple dispersion discs 112. The multiple dispersion discs 112 are all set in an inclined manner on the guide plates 113, and the inclination directions of the guide plates 113 on two adjacent layers of dispersion discs 112 are opposite.

[0037] Specifically, when the first servo motor 114 drives the rotating shaft 111 to rotate at high speed, it can drive multiple dispersing discs 112 to rotate at high speed. When the dispersing discs 112 rotate at high speed, they can throw out materials under the action of centrifugal force. The thrown materials act on the guide plate 113. Through the guidance of the guide plate 113, the simple circular motion of the materials is broken, and the radially moving materials are guided to the axial direction, that is, upward or downward. This makes the materials form a complex spiral up-and-down circulating material flow in the processing chamber, which greatly improves the efficiency and uniformity of macroscopic mixing. This allows materials with different specific gravities to be mixed evenly. Furthermore, the interaction between the materials and the dispersing plate 110 improves the mixing and dispersion effect. At the same time, the rotating shaft 111 is sleeved in the hollow output shaft 16 in a through manner, so that the rotation of the rotating shaft 111 and the hollow output shaft 16 will not interfere with each other. This allows the frame stirring rod 17 and the rotating shaft 111 to rotate independently. During use, the frame stirring rod 17 and the rotating shaft 111 can rotate at different speeds according to the needs.

[0038] like Figures 1-4As shown, the mixing mechanism 1 also includes a feed pipe 115, a discharge pipe 116, a circulation pipe 117, a liquid inlet pipe 118, and a liquid outlet pipe 119. The feed pipe 115 is mounted on the planetary gearbox 14, the discharge pipe 116 is mounted on the bottom wall of the processing chamber, the circulation pipe 117 is mounted on the side wall of the discharge pipe 116, the liquid inlet pipe 118 is mounted on the side wall of the outer casing 11 at the top, and the liquid outlet pipe 119 is mounted on the bottom side wall of the outer casing 11. When the material in the processing chamber needs to be heated, the liquid inlet pipe 118 can transport heating oil to the jacket to heat the material. The heated oil is discharged through the liquid outlet pipe 119 for circulation. The circulating material pipe 117 is used to transport and process the material in the processing chamber. The circulating material pipe 117 should be installed above the switch valve on the discharge pipe 116. At the same time, a switch valve should also be installed on the circulating material pipe 117 so that the material can be transported separately through the discharge pipe 116 and the circulating material pipe 117.

[0039] like Figure 1 , Figure 6 , Figure 7 and Figure 9 As shown, the fiber dispersion mechanism 2 includes a venturi tube 21, a first air inlet pipe 22, a fiber conveying pipe 23, a cyclone disperser 24, a connecting flange 25, a feed plate 26, a first tangential air inlet 27, a second tangential air inlet 28, a secondary air ring 29, a second air inlet pipe 211, and a discharge pipe 212. The first air inlet pipe 22 is installed on the top wall of the venturi tube 21, the fiber conveying pipe 23 is installed on the side wall of the throat section of the venturi tube 21, the cyclone disperser 24 is installed at the bottom of the venturi tube 21, and the cyclone disperser 24 and the venturi tube 21 are connected together by the connecting flange 25. The feed plate 26 is integrally formed at the upper port of the cyclone disperser 24, and the first tangential air inlet 27 is opened in a manner parallel to the horizontal plane. Located on the side wall of the feed plate 26, the second tangential air inlet 28 is opened on the bottom wall of the feed plate 26 at an angle of 30-45 degrees to the horizontal plane. The secondary air ring 29 is fixedly connected to the bottom of the outlet end of the cyclone disperser 24. Multiple nozzles 210 are provided and are opened at equal intervals in an inclined manner on the side wall of the inner ring of the secondary air ring 29. The second air inlet pipe 211 is fixedly connected to the side wall of the outer ring of the secondary air ring 29. The discharge pipe 212 is fixedly connected to the bottom of the secondary air ring 29 and is fixedly connected to the mounting cover 13 in a through manner. The outlet end of the discharge pipe 212 is inclined towards the inner side wall of the inner shell 12. Wear-resistant liners are provided inside the venturi tube 21 and the cyclone disperser 24.

[0040] Specifically, the fibers are fed into the Venturi tube 21 via a quantitative conveying mechanism. The main airflow within the Venturi tube 21, delivered by the first air inlet 22, initially accelerates the fibers. The fiber-airflow mixture is then injected into the cyclone disperser 24 through the first tangential air inlet 27 and the second tangential air inlet 28 in a dual-tangential orthogonal inlet configuration for dispersion. Within the cyclone disperser 24, continuous tearing forces in different directions are generated on the fiber clusters, significantly improving the fiber monofilamentization efficiency. To further enhance fiber processing efficiency within the cyclone disperser 24, guide vanes can be installed to precisely guide the airflow. Simultaneously, the two orthogonal vortices generated by the first tangential air inlet 27 and the second tangential air inlet 28 create strong convection and shearing within the cyclone disperser 24, eliminating dispersion dead zones. This causes the fiber clusters to experience tearing forces from different directions in three-dimensional space, greatly improving dispersion uniformity and efficiency. The fiber movement changes from "two-dimensional rotation" to "three-dimensional tumbling," resulting in more thorough dispersion. Meanwhile, the lower part of the cyclone disperser 24 is designed as a conical constriction section, with the diameter of the cavity gradually decreasing from top to bottom. According to Bernoulli's principle, the reduction in cross-section leads to an increase in airflow velocity, resulting in final acceleration and shearing of the fibers. The fibers dispersed in the cyclone disperser 24 are then further dispersed by the secondary air ring 29. When the fibers are conveyed into the processing chamber through the inclined discharge pipe 212, they act on the inner wall of the inner shell 12 and come into contact with the slurry, avoiding direct blowing into the slurry and generating air bubbles that would affect the mixing quality.

[0041] like Figure 4 and Figure 10As shown, the stripping mechanism 3 includes a stator 31, a spiral microgroove 32, a rotor 33, a material conveying gap 34, a material conveying housing 35, a sealing ring 36, a feeding pipe 37, a collecting hood 38, a return pipe 39, a drive shaft 310, and a second servo motor 311. The interior of the stator 31 is configured as a conical cavity. The rotor 33 is coaxially rotatably connected to the interior cavity of the stator 31. The inner wall of the stator 31 has a spiral microgroove 32, the spiral direction of which is opposite to the rotation direction of the rotor 33. The material conveying gap 34 is formed between the inner wall of the stator 31 and the outer wall of the spiral microgroove 32. The width of the material conveying gap 34 is gradually narrowed from top to bottom. The upper end of the material conveying gap 34 is in position. A material conveying housing 35 is installed above the stator 31 and the rotor 33. A sealing ring 36 is set at the connection between the material conveying housing 35 and the rotor 33. A feeding pipe 37 is installed on the top wall of the material conveying housing 35. A conveying pump 312 is installed at the end of the feeding pipe 37 away from the material conveying housing 35. The end of the circulating material pipe 117 away from the discharge pipe 116 is installed on the inlet of the conveying pump 312. A material collecting hood 38 is installed at the bottom of the stator 31. A return pipe 39 is installed at the bottom of the material collecting hood 38. The end of the return pipe 39 away from the material collecting hood 38 is installed on the side wall of the feed pipe 115. A drive shaft 310 is coaxially fixedly connected to the rotor 33. A second servo motor 311 is installed on the drive shaft 310.

[0042] Specifically, the mixed solvent, which has undergone preliminary mixing in the processing chamber, is transported through the circulation pipe 117 and pumped by the delivery pump 312 into the feed pipe 37. Then, it is transported through the feed pipe 37 into the feed housing 35. The feed housing 35 transports the solvent into the feed gap 34 formed by the stator 31 and the rotor 33. Simultaneously, the rotor 33 is driven by the second servo motor 311 to start rotating at a low speed, typically 50-300 RPM. Due to the spiral microgrooves 32 on the surface of the stator 31 and the viscous dragging effect, the material is gently transported downwards in the feed gap 34. As the material moves downwards, the feed gap 34 becomes narrower and narrower. According to the principles of fluid mechanics, in the narrow gap, the material will be subjected to increasingly greater laminar shear stress. This shear force is uniform, linear, and precisely controllable. This continuously increasing shear force is sufficient to overcome the van der Waals forces between the slurry layers, gently "tearing" them apart layer by layer without violently tearing the pages themselves. Furthermore, the solvent processed within the conveying gap 34 is transported to the processing chamber through the return pipe 39. This process will be repeated multiple times until the online monitoring system detects that the particle size of the slurry has reached the predetermined target value.

[0043] It should be noted that the preparation equipment is equipped with electrical components such as sensors required for automated control, so as to realize real-time monitoring of important indicators such as particle size and viscosity during material dispersion and mixing. This technology is a mature existing technology and will not be described in detail here.

[0044] In use, a portion of epoxy resin, solvent, and additives are added to the processing chamber, and the mixing and dispersing assembly is started for low-speed stirring and mixing. Then, a composite flame-retardant system and hydrophobic silica aerogel powder are added to the processing chamber, and the mixing and dispersing assembly is switched to high-speed rotation mode for dispersion until the material fineness is qualified. The fiber dispersion mechanism 2 is started, and the short-cut fibers are formed into an aerosol in the Venturi tube 21 by compressed air, and then injected into the cyclone disperser 24 through the first tangential air inlet 27 and the second tangential air inlet 28 in a double tangential orthogonal inlet tangential manner for dispersion. Subsequently, the dispersed fibers are sprayed into the paint slurry in the processing chamber. The material and solvent in the processing chamber are pumped into the peeling mechanism 3 for circulation processing. The laminar shear force generated by the conical conveying gap 34 between the stator 31 and the rotor 33 is used to peel off the nanosheets, and the pre-gel is prepared and transported back to the processing chamber. The remaining epoxy resin is added to the processing chamber, and the mixing and dispersing assembly is switched to low-speed stirring mode for mixing. After vacuum degassing, component A of the fire-retardant coating is obtained.

[0045] The preparation method of the short fiber-based ultra-tough fire-retardant coating for main cables includes the following steps: S1. Material premixing: Add a portion of epoxy resin, solvent and additives to the processing chamber, and start the mixing and dispersing components to mix at low speed; S2, Dispersing flame retardant system and aerogel: Add composite flame retardant system and hydrophobic silica aerogel powder to the processing chamber, switch the mixing and dispersing component to high-speed rotation mode for dispersion until the material fineness is qualified; S3. Fiber individualization dispersion and addition: Start the fiber dispersion mechanism 2, and form an aerosol in the Venturi tube 21 by compressed air. Then, inject the short-cut fibers into the cyclone disperser 24 through the first tangential air inlet 27 and the second tangential air inlet 28 in a double tangential orthogonal inlet tangential manner for dispersion. Then, spray the dispersed fibers into the paint slurry in the processing chamber. S4. Nanosheet peeling and addition: The material and solvent in the processing chamber are pumped into the peeling mechanism 3 for circulation processing. The laminar shear force generated by the conical feeding gap 34 between the stator 31 and the rotor 33 is used to peel off the nanosheets. After preparing the pregel, it is transported back to the processing chamber. S5. Final blending: Add the remaining epoxy resin to the processing chamber, switch the mixing and dispersing components to low-speed stirring mode for blending, and after vacuum degassing, obtain component A of the fire-retardant coating; S6. Packaging: Separate component A and component B curing agent into separate packages.

[0046] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0047] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A short-fiber-based ultra-tough fire-retardant coating for main cables, comprising a two-component system including component A and component B (curing agent), characterized in that: Component A comprises the following raw materials in parts by weight: 30-50 parts epoxy resin, 25-40 parts composite flame retardant system, 5-15 parts hydrophobic silica aerogel powder, 3-8 parts chopped fibers, 2-5 parts additives, 5-10 parts pigments and fillers, and 10-20 parts solvent; the length of the chopped fibers is 50-200 μm.

2. The short-fiber-based ultra-tough fire-retardant coating for main cables according to claim 1, characterized in that, The chopped fibers are selected from one or more of basalt fibers, aramid fibers, or glass fibers.

3. The short-fiber-based ultra-tough fire-retardant coating for main cables according to claim 1, characterized in that, The pore size of the hydrophobic silica aerogel powder is less than 70 nanometers.

4. A preparation apparatus for a short-fiber-based ultra-tough fire-retardant coating for main cables, used to prepare the short-fiber-based ultra-tough fire-retardant coating for main cables as described in any one of claims 1 to 3, characterized in that, include: A mixing mechanism includes an outer shell, an inner shell, a mounting cover, and a mixing and dispersing assembly. The inner shell is integrally formed inside the outer shell to form a sandwiched processing chamber. The mounting cover is installed on the top of the processing chamber. The mixing and dispersing assembly is installed inside the processing chamber for mixing and dispersing materials. A fiber dispersion mechanism, mounted on the mounting cover, is used to disperse chopped fibers and then feed them into the processing chamber. The peeling mechanism is connected to the processing chamber through a circulation pipeline to form a circulation loop for processing nanosheet materials; The control system includes a control unit and a viscosity monitoring unit.

5. The equipment for preparing the short-fiber-based ultra-tough fire-retardant coating for main cables according to claim 4, characterized in that, The mixing and dispersing assembly includes a planetary gearbox, mounting holes, a hollow output shaft, a frame-type stirring rod, a first scraper, a second scraper, a dispersing plate, a dispersing disk, a guide plate, a first servo motor, and a main drive motor. Specifically: The planetary gearbox is mounted on the mounting cover, and the mounting hole is coaxially opened on the mounting cover. The hollow output shaft is driven to rotate by the driving component inside the planetary gearbox. The main drive motor is mounted on the side wall of the planetary gearbox to drive the driving component to rotate. The hollow output shaft passes through the mounting hole coaxially and is placed in the processing chamber. The center line of the upper wall plate of the frame-type stirring rod is fixedly connected to the bottom of the hollow output shaft coaxially. The first scraper is fixedly connected in pairs to the outer walls of the left and right vertical plates of the frame-type stirring rod. The second scraper is provided in pairs and is fixedly connected to the bottom of the left and right vertical plates of the frame-type stirring rod. Multiple dispersing plates are provided and are fixedly connected to the inner walls of the left and right vertical plates of the frame-type stirring rod at equal intervals. The multiple dispersing plates on the inner walls of the left and right vertical plates of the frame-type stirring rod are inclined in opposite directions.

6. The equipment for preparing the short-fiber-based ultra-tough fire-retardant coating for main cables according to claim 5, characterized in that, The rotating shaft passes coaxially through the top wall of the planetary gearbox, the hollow output shaft, and the frame-type stirring rod, extending to a position near the bottom of the processing chamber. The rotating shaft is rotatably mounted on the top wall of the planetary gearbox and the frame-type stirring rod. The first servo motor is mounted above the rotating shaft. Multiple dispersion discs are fixedly connected to the side wall of the rotating shaft below the frame-type stirring rod at equal intervals. Multiple guide plates are fixedly connected at equal intervals on the upper surface of the edges of the multiple dispersion discs. The multiple dispersion discs are all inclined on the guide plates, and the inclination directions of the guide plates on adjacent layers of dispersion discs are opposite.

7. The equipment for preparing the short-fiber-based ultra-tough fire-retardant coating for main cables according to claim 6, characterized in that, The mixing mechanism also includes a feed pipe, a discharge pipe, a circulation pipe, a liquid inlet pipe, and a liquid outlet pipe, specifically: The feed pipe is installed on the planetary gearbox, the discharge pipe is installed on the bottom wall of the processing chamber, the circulating pipe is installed on the side wall of the discharge pipe, the liquid inlet pipe is installed on the side wall of the outer shell at the top position, and the liquid outlet pipe is installed on the bottom side wall of the outer shell.

8. The equipment for preparing the short-fiber-based ultra-tough fire-retardant coating for main cables according to claim 7, characterized in that, The fiber dispersion mechanism includes a venturi tube, a first air inlet pipe, a fiber conveying pipe, a cyclone disperser, a connecting flange, a feed plate, a first tangential air inlet, a second tangential air inlet, a secondary air ring, a second air inlet pipe, and a discharge pipe. Specifically: The first air inlet pipe is installed on the top wall panel of the venturi tube, the fiber conveying pipe is installed on the side wall of the throat section of the venturi tube, the cyclone disperser is installed at the bottom of the venturi tube, and the cyclone disperser and the venturi tube are connected together by a connecting flange. The feed plate is integrally formed at the upper port of the cyclone disperser. The first tangential air inlet is opened on the side wall of the feed plate in a manner parallel to the horizontal plane, and the second tangential air inlet is opened at an angle of 30-45 degrees to the horizontal plane at the bottom of the feed plate. On the wall panel, the secondary air ring is fixedly connected to the bottom of the outlet end of the cyclone disperser. Multiple nozzles are provided and are equally spaced at an inclined position on the side wall of the inner ring of the secondary air ring. The second air inlet pipe is fixedly connected to the side wall of the outer ring of the secondary air ring. The discharge pipe is fixedly connected to the bottom of the secondary air ring and is fixedly connected to the mounting cover in a through manner. The outlet end of the discharge pipe is inclined towards the inner side wall of the inner shell. Wear-resistant liners are provided inside the venturi tube and the cyclone disperser.

9. The equipment for preparing the short-fiber-based ultra-tough fire-retardant coating for main cables according to claim 8, characterized in that, The stripping mechanism includes a stator, a spiral microgroove, a rotor, a feeding gap, a feeding housing, a sealing ring, a feeding pipe, a collecting hood, a return pipe, a drive shaft, and a second servo motor. Specifically: The stator has a conical cavity inside, and the rotor is coaxially connected to the internal cavity of the stator. A spiral microgroove is formed on the inner wall of the stator, with the spiral direction opposite to the rotor's rotation direction. A material conveying gap is formed between the inner wall of the stator and the outer wall of the spiral microgroove, and the width of the material conveying gap gradually narrows from top to bottom. A material conveying housing is installed at the upper end of the material conveying gap, above the stator and rotor. A sealing ring is located at the connection between the material conveying housing and the rotor. A feeding pipe is installed on the top wall of the material conveying housing. A conveying pump is installed at the end of the feeding pipe away from the material conveying housing. The end of the circulating material pipe away from the discharge pipe is installed at the inlet of the conveying pump. A material collecting hood is installed at the bottom of the stator. A return pipe is installed at the bottom of the material collecting hood, and the end of the return pipe away from the material collecting hood is installed on the side wall of the feeding pipe. The drive shaft is coaxially fixed to the rotor, and the second servo motor is installed on the drive shaft.

10. A method for preparing a short-fiber-based ultra-tough fire-retardant coating for main cables, used in the preparation equipment for the short-fiber-based ultra-tough fire-retardant coating for main cables as described in any one of claims 4 to 9, characterized in that, Includes the following steps: S1. Material premixing: Add a portion of epoxy resin, solvent and additives to the processing chamber, and start the mixing and dispersing components to mix at low speed; S2, Dispersing flame retardant system and aerogel: Add composite flame retardant system and hydrophobic silica aerogel powder to the processing chamber, switch the mixing and dispersing component to high-speed rotation mode for dispersion until the material fineness is qualified; S3. Individualized fiber dispersion and addition: Start the fiber dispersion mechanism to form an aerosol in the Venturi tube by compressed air, and then inject it into the cyclone disperser through the first tangential air inlet and the second tangential air inlet in a double tangential orthogonal inlet tangential manner for dispersion. Then, the dispersed fiber is sprayed into the paint slurry in the processing chamber. S4. Nanosheet peeling and addition: The material and solvent in the processing chamber are pumped into the peeling mechanism for circulation. The laminar shear force generated by the conical feeding gap between the stator and rotor is used to peel the nanosheets. After being prepared into a pregel, it is transported back to the processing chamber. S5. Final blending: Add the remaining epoxy resin to the processing chamber, switch the mixing and dispersing components to low-speed stirring mode for blending, and after vacuum degassing, obtain component A of the fire-retardant coating; S6. Packaging: Disassemble the A component and the B component curing agent into separate packages.

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