Salt lake water mining ship trailing cable and preparation method thereof

Abstract

The invention discloses a salt lake water mining ship trailing cable and a preparation method thereof, the cable comprises an outer sheath, an inner sheath, an aramid fiber braid layer and a cable core which are sequentially arranged from outside to inside, and the cable core comprises a triangular filling member; the main line units are distributed on the periphery of the triangular filling piece; and a ground wire unit. The invention discloses a trailing cable for a salt lake water mining ship with medium voltage of 8.7 / 15kV and below, which is mainly used for external power supply of a salt lake water mining machine and has the characteristics of tensile strength, corrosion resistance, water immersion resistance, weather resistance, salt mist resistance, water resistance, excellent bending performance and the like, the surface of the cable is not subjected to salt deposition, and long-term, stable and high-voltage power supply can be realized; the triangular filling piece is formed by four groups of aramid fiber bundles and is filled in the center of the cable core, so that the tensile property of the cable is improved, the shape of the cross section of the cable is kept stable, wrinkles or flattening during bending are avoided, all units are isolated, the relative positions of the units are fixed, and friction damage caused by vibration and bending during operation is prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of cables, and in particular relates to a salt lake water mining vessel towing cable and a preparation method thereof. Background Art

[0002] There are a large number of salt lake water mining companies in my country. Due to their harsh environment and special operating conditions, ordinary cables cannot withstand the bending force of water mining ships and strong winds for a long time, as well as being immersed in saturated brine. Problems such as water ingress, surface corrosion, mold growth, and salt accumulation are prone to occur. The cables are often damaged and have a very short lifespan. Therefore, there is an urgent need to develop a new type of salt lake water mining ship towing cable. Summary of the Invention

[0003] In order to solve the problems in the prior art, the purpose of the present invention is to provide a salt lake water mining vessel towing cable and a preparation method thereof.

[0004] In order to achieve the above-mentioned purpose and the above-mentioned technical effect, the technical solution adopted by the present invention is:

[0005] A towing cable for a salt lake water mining vessel comprises an outer sheath, an inner sheath, an aramid braided layer and a cable core, which are arranged in sequence from the outside to the inside. The cable core comprises:

[0006] The triangular filler is located in the center of the cable core;

[0007] There are several main line units, distributed around the periphery of the triangular filling piece;

[0008] There are several ground line units in total, and at least one ground line unit is set between every two adjacent main line units.

[0009] Furthermore, the thickness of the outer sheath is 2.5-5 mm, the thickness of the inner sheath is 2-3 mm, and both the outer sheath and the inner sheath are made of chlorosulfonated polyethylene rubber material.

[0010] Furthermore, the raw materials for preparing the chlorosulfonated polyethylene rubber material include the following components in parts by weight: 80-120 parts of chlorosulfonated polyethylene

[0011] 40-70 parts of core-shell structure nanocomposite filler

[0012] 20-30 parts of high wear-resistant carbon black

[0013] 5-15 parts of magnesium oxide

[0014] 5-15 parts plasticizer

[0015] 2-5 parts of nano-silica aerogel particles

[0016] 1-5 parts of rare earth complex activator

[0017] 1-3 parts of accelerator

[0018] 1-3 parts antioxidant

[0019] 0.5-2 parts of anti-scorching agent

[0020] 0.5-2 parts of metal passivator

[0021] 0.5-2 parts crosslinking agent

[0022] 0.5-1.5 parts of stearic acid

[0023] 2-5 parts of wax processing aids.

[0024] Furthermore, in the core-shell structure nanocomposite filler, the core is modified nano-kaolin and the shell is a two-dimensional nanosheet material, and the two-dimensional nanosheet material is graphene oxide or Ti3C2T x MXene, the mass ratio of the two-dimensional nanosheets to the modified nano-kaolin is 1:5-20.

[0025] Furthermore, the specific surface area of ​​the nano-silica aerogel particles is ≥600 m2 / g, and the surface is modified by hexamethyldisilazane.

[0026] Furthermore, the aramid braided layer is made of 2-8 1100D aramid fiber yarns woven into a diamond grid structure at a crossing angle of 40°-50°.

[0027] Furthermore, the triangular filling piece includes a plurality of fiber bundles, and the fiber bundles are connected into one body by rubber material.

[0028] Furthermore, there are three main line units, all distributed around the triangular filler, and each main line unit includes a conductor and a conductor shield, insulation, insulation shield, and braided shield arranged on the outside of the conductor from the inside to the outside.

[0029] Furthermore, each of the ground wire units includes a ground wire conductor and an insulating layer extruded around the outside of the ground wire conductor. The present invention also discloses a method for preparing a towing cable for a salt lake water mining vessel, comprising the following steps:

[0030] (1) The conductor and the ground conductor are respectively made of multiple strands of annealed tinned copper monofilaments twisted together;

[0031] (2) making conductor shielding, insulation, insulation shielding, and braided shielding on the outside of the conductor in sequence to obtain a main line unit;

[0032] Extruding an insulating layer on the outside of the ground wire conductor to obtain a ground wire unit;

[0033] (3) Prepare a triangular filler, then place the three main line units in the three grooves of the triangular filler respectively, and set a ground line unit between every two adjacent main line units to ensure that the triangular filler is located in the center position. After the arrangement is completed, the cable is made. Before the cable is made, the cable core is first coated with talcum powder, and then wrapped with a water-blocking tape to make the cable. After that, an aramid braided layer is woven on the outside of the water-blocking tape;

[0034] (4) An inner sheath and an outer sheath are co-extruded outside the aramid braided layer.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1) The present invention discloses a medium voltage 8.7 / 15kV and below salt lake water mining ship towing cable, which is mainly used for external power supply of salt lake water mining equipment. It has the characteristics of tensile strength, corrosion resistance, water immersion resistance, weather resistance, salt spray resistance, waterproofness, excellent bending performance, etc., excellent shielding performance and insulation performance, no salt accumulation on the cable surface, and can provide long-term, stable, high-voltage power supply;

[0037] 2) Both the inner and outer sheaths of the present invention are made of chlorosulfonated polyethylene rubber material, which has excellent physical and mechanical properties, and is resistant to oil, heat, sunlight, ozone, acid and alkali. When the outer sheath is damaged, the inner sheath can still protect the cable and can be used normally in the short term;

[0038] 3) The aramid braided layer of the present invention uses 2-8 1100D aramid fiber filaments woven into a diamond grid structure at a 40°-50° cross angle. When the cable is wound and bent, the longitudinal tensile force on the surface of the bent cable core is relatively large. The grid structure can disperse the bending and tensile force, and the cable core and sheath shrink synchronously, preventing internal and external separation, thereby increasing the fatigue resistance and bending life of the cable and facilitating the long-term use of the cable.

[0039] 4) The triangular filler of the present invention is formed by four groups of aramid fiber bundles and rubber materials to form a triangular support, which is filled in the central position of the cable core, so that the tensile performance of the cable is further improved, and the tensile performance of the cable can be met with less filling material. The cable cross-sectional space can be efficiently utilized, and the cable diameter is smaller, the weight is lighter, and the internal units are more compact, which is conducive to maintaining the stability of the cable cross-sectional shape, avoiding wrinkles or flattening when bending, ensuring smooth sliding during dragging, and helping to reduce internal wear, isolate each unit and fix their relative positions, prevent friction damage caused by vibration and bending during operation, reduce the risk of short circuit, and have the characteristics of low temperature resistance (-40℃) and salt spray corrosion resistance. It cooperates with the cable sheath for protection and adapts to high humidity and low temperature environments on lakes and seas. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0041] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0042] The following is a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that will be provided later.

[0043] like Figure 1 As shown, a salt lake water mining ship towing cable is a medium voltage 8.7 / 15kV and below salt lake water mining ship towing cable, which is mainly used for external power supply of salt lake water mining machines. It has the characteristics of tensile strength, corrosion resistance, water immersion resistance, weather resistance, salt spray resistance, waterproofness, and excellent bending performance. Salt does not form on the cable surface, and the cable can provide long-term, stable, high-voltage power supply.

[0044] A towing cable for a salt lake water mining vessel comprises an outer sheath 1, an inner sheath 2, an aramid braided layer 3 and a cable core 4, which are arranged in sequence from the outside to the inside. The cable core 4 comprises:

[0045] The triangular filler 5 comprises a plurality of fiber bundles, which are connected together by rubber material;

[0046] There are several main line units 6, which are evenly distributed around the triangular filler 5. Each main line unit 6 includes a conductor 7 and a conductor shield 8, an insulation 9, an insulation shield 10, and a braided shield 11 arranged on the outside of the conductor 7 from the inside to the outside.

[0047] There are several ground wire units 12, which are evenly distributed around the triangular filler 5. At least one ground wire unit 12 is set between every two adjacent main line units 6. Each ground wire unit 12 includes a ground wire conductor 13 and an insulating layer 14 extruded around the outside of the ground wire conductor 13.

[0048] In some embodiments, the outer sheath 1 is 2.5-5 mm thick and made of chlorosulfonated polyethylene rubber. Even if the outer sheath 1 is damaged, the inner sheath 2 can still protect the cable, allowing for short-term normal use. In some embodiments, the inner sheath 2 is 2-3 mm thick and made of chlorosulfonated polyethylene rubber, which exhibits excellent physical and mechanical properties, including resistance to oil, heat, sunlight, ozone, and acids and alkalis.

[0049] In some more specific embodiments, the raw materials for preparing the chlorosulfonated polyethylene rubber material include the following components in parts by weight:

[0050] 80-120 parts of chlorosulfonated polyethylene

[0051] 40-70 parts of core-shell structure nanocomposite filler

[0052] 20-30 parts of high wear-resistant carbon black

[0053] 5-15 parts of magnesium oxide

[0054] Plasticizer (epoxidized cashew nut shell oil or diisodecyl phthalate) 5-15 parts

[0055] 2-5 parts of nano-silica aerogel particles

[0056] 1-5 parts of rare earth complex activator (lanthanum laurate or cerium laurate)

[0057] 1-3 parts of accelerator

[0058] 1-3 parts antioxidant (2,6-di-tert-butyl-4-methylphenol)

[0059] Anti-scorch agent (N,N'-di(β-naphthyl)-p-phenylenediamine or N-cyclohexylthiophthalamide) 0.5-2 parts

[0060] 0.5-2 parts of metal passivator

[0061] 0.5-2 parts crosslinking agent

[0062] 0.5-1.5 parts of stearic acid

[0063] 2-5 parts of wax processing aid (chlorinated paraffin or other similar substances).

[0064] In some more specific embodiments, the preparation steps of the chlorosulfonated polyethylene rubber material are:

[0065] Step 1: First, knead chlorosulfonated polyethylene, rare earth complex activator, magnesium oxide, and stearic acid for 3-5 minutes at a temperature of 80-100°C;

[0066] Step 2: Add core-shell structure nanocomposite filler, high wear-resistant carbon black, nano-silica aerogel particles, plasticizer, and wax processing aid, and mix for 8-12 minutes at a temperature of 110-120°C;

[0067] Step 3: Cool down to below 70°C, add accelerator, anti-scorch agent, antioxidant, metal passivator, and cross-linking agent, mix well, and then produce sheets;

[0068] Curing conditions: one stage curing 150-160℃×t 90 +10% time, second stage vulcanization 100℃×3-6h.

[0069] In some more specific embodiments, in the core-shell structure nanocomposite filler, the core is modified nano-kaolin, the shell is a two-dimensional nanosheet material, and the two-dimensional nanosheet material is graphene oxide or Ti3C2T x The mass ratio of MXene, two-dimensional nanosheets and modified nano-kaolin is 1:5-20. The preparation steps of core-shell structure nanocomposite filler are as follows:

[0070] 1) Reflux the nano-kaolin in a silane coupling agent KH-550 ethanol solution for 2-5 hours;

[0071] 2) Mix the graphene oxide or MXene dispersion with the product obtained in step 1), ultrasonically treat for 30-60 min, and then ball-mill to a particle size of D after drying. 50 ≤5μm.

[0072] In some more specific embodiments, the specific surface area of ​​the nano-silica aerogel particles is ≥ 600 m 2 / g, the surface was modified with hexamethyldisilazane.

[0073] In some more specific embodiments, the cross-linking agent is di-tert-butyl diisopropyl peroxide.

[0074] In some more specific embodiments, the accelerator is a mixture of accelerator DM, accelerator M, and accelerator D in a mass ratio of 1-2:1-3:1.

[0075] In some embodiments, the aramid braided layer 3 comprises 2-8 1100D aramid fiber filaments woven into a diamond-shaped grid structure at a 40-50° cross-angle. The multiple aramid fiber filaments are bundled and then braided onto the outer surface of the cable core using a braiding machine. When the cable is wound and bent, the longitudinal tensile stress on the curved cable core surface is greater. The grid structure disperses the bending and tensile forces, allowing the cable core and sheath to contract synchronously, preventing separation between the inner and outer layers. This increases the cable's fatigue resistance and bending life, facilitating long-term cable use.

[0076] In some embodiments, before cabling, the cable core 4 is first coated with talcum powder and then wrapped with a water-blocking tape to reduce friction and contact areas between components in the cable core. The aramid braided layer 3 is then woven outside the water-blocking tape.

[0077] In some more specific embodiments, the mesh size of the talc powder is 1400-1600 mesh, and the particle size is ≤45 μm, which can ensure the uniformity and stability of the talc powder during the filling process, and the water-blocking tape can fully improve the water-blocking performance of the cable.

[0078] In some embodiments, the triangular filler 5 includes four groups of aramid fiber bundles, one of which is located in the center, and the other three groups are symmetrically distributed at 120 degrees to form a triangular support. The four groups of aramid fiber bundles are filled with rubber material, and the triangular filler 5 is located in the center of the cable core 4. The aramid fiber bundles serve as a reinforcing core, which further improves the tensile performance of the cable. Less filling material can be used to meet the tensile performance of the cable, and the cable cross-sectional space can be efficiently utilized, making the cable smaller in diameter, lighter in weight, and more compact in internal units. It is beneficial to maintain the stability of the cable cross-sectional shape, avoid wrinkles or flattening when bending, and ensure smooth sliding during dragging. It is beneficial to reduce internal wear, isolate each unit and fix their relative position, prevent friction damage caused by vibration and bending during operation, and reduce the risk of short circuits. It has the characteristics of low temperature resistance (-40°C) and salt spray corrosion resistance, and cooperates with the cable sheath for protection, and is suitable for high humidity and low temperature environments on lakes and at sea.

[0079] In some embodiments, conductor 7 is constructed from multiple strands of annealed tinned copper monofilaments. Its composition, performance, and appearance must comply with the requirements of GB / T3956. Conductor 7 must have a smooth surface, free of burrs, sharp edges, protrusions, or broken monofilaments, and its resistance must comply with GB / T3956. The monofilament tolerance is ±0.002 mm, and the monofilaments are closely spaced. This ensures uniform stress distribution across the monofilaments during the pulling process, minimizing the risk of breakage and distributing the tension.

[0080] In some embodiments, the conductor shield 8 has a thickness of 0.4-0.8 mm and a shield resistivity of ≤800 Ω·m, which neutralizes the irregularities on the surface of the conductor 7 and balances the electric field.

[0081] In some embodiments, the insulation 9 is made of high-purity EPDM material, with an average thickness not less than the nominal thickness and a thickness at the thinnest point not less than 90%-0.1 of the nominal thickness.

[0082] In some embodiments, the insulating shield 10 has a thickness of 0.4-0.9 mm, a shield resistivity of ≤400 Ω·m, and a peeling force of 8-40 N, and is used to balance the external electric field.

[0083] In some embodiments, the braided shield 11 is woven from a mixture of aramid fiber and tinned copper wire (tin layer thickness ≥ 2 μm), with a braiding angle of 45°-60°, a braiding coverage ≥ 80%, and a aramid fiber proportion ≥ 70%. It can well protect the internal conductor and insulation from damage, and has the advantages of high strength, chemical corrosion resistance, acid and alkali resistance, wear resistance, and non-oxidation, and can meet the electrical performance required for shielding for a long time.

[0084] In some embodiments, the diameters of the ground conductor 13 and conductor 7 are different, with the diameter of conductor 7 being larger than that of the ground conductor 13. The ground conductor 13 is constructed from multiple strands of annealed tinned copper monofilaments. Its composition, performance, and appearance must comply with the requirements of GB / T3956. The surface of the ground conductor 13 is smooth, free of burrs, sharp edges, protrusions, or broken monofilaments, and its resistance complies with the requirements of GB / T3956. The monofilament tolerance is ±0.002 mm, and the monofilaments are closely spaced. During the pulling process, the monofilaments of the ground conductor 13 are evenly stressed, reducing the risk of breakage and distributing the tension.

[0085] In some embodiments, the insulating layer 14 is made of high-purity EPDM material, with an average thickness not less than the nominal thickness and a thickness at the thinnest point not less than 90% - 0.1 of the nominal thickness. The insulating layer 14 and the insulation 9 are made of the same material but with different thicknesses.

[0086] The present invention also discloses a method for preparing a towing cable for a salt lake water mining vessel, comprising the following steps:

[0087] (1) The conductor 7 and the ground conductor 13 are respectively formed by twisting a plurality of annealed tinned copper monofilaments;

[0088] (2) a conductor shield 8, an insulation 9, an insulation shield 10, and a braided shield 11 are sequentially formed outside the conductor 7 to obtain a main line unit 6;

[0089] An insulating layer 14 is extruded outside the ground conductor 13 to obtain a ground unit 12;

[0090] (3) Arrange four groups of aramid fiber bundles as required and extrude rubber material to obtain a triangular filling piece 5, then place multiple main line units 6 in the three grooves of the triangular filling piece 5, and set at least one ground line unit 12 between every two adjacent main line units 6 to ensure that the triangular filling piece 5 is located in the center. After the arrangement is completed, the cable is formed. Before the cable is formed, the cable core 4 is first coated with talcum powder, and then wrapped with a water-blocking tape to form a cable, and then the aramid braided layer 3 is woven on the outside of the water-blocking tape;

[0091] (4) The inner sheath 2 and the outer sheath 1 are co-extruded outside the aramid braided layer 3.

[0092] Example 1

[0093] like Figure 1 As shown, a salt lake water mining ship towing cable is a medium voltage 8.7 / 15kV and below salt lake water mining ship towing cable, which is mainly used for external power supply of salt lake water mining machines. It has the characteristics of tensile strength, corrosion resistance, water immersion resistance, weather resistance, salt spray resistance, waterproofness, and excellent bending performance. Salt does not form on the cable surface, and the cable can provide long-term, stable, high-voltage power supply.

[0094] A towing cable for a salt lake water mining vessel comprises an outer sheath 1, an inner sheath 2, an aramid braided layer 3 and a cable core 4, which are arranged in sequence from the outside to the inside. The cable core 4 comprises:

[0095] The triangular filler 5 includes four groups of aramid fiber bundles, one of which is located in the center, and the other three groups are symmetrically distributed at 120 degrees to form a triangular support. The four groups of aramid fiber bundles are filled with chlorosulfonated polyethylene rubber. The triangular filler 5 is located in the center of the cable core 4;

[0096] There are three main line units 6, which are evenly distributed around the triangular filler 5. Each main line unit 6 includes a conductor 7 and a conductor shield 8, an insulation 9, an insulation shield 10, and a braided shield 11 arranged on the outside of the conductor 7 from the inside to the outside.

[0097] There are three ground wire units 12 , which are evenly distributed around the triangular filler 5 . One ground wire unit 12 is set between every two adjacent main wire units 6 . Each ground wire unit 12 includes a ground wire conductor 13 and an insulating layer 14 extruded around the outside of the ground wire conductor 13 .

[0098] In this embodiment, the outer sheath 1 is 2.5 mm thick and is made of chlorosulfonated polyethylene rubber. Even if the outer sheath 1 is damaged, the inner sheath 2 can still protect the cable and can be used normally in the short term.

[0099] The thickness of the inner sheath 2 is 3 mm, and it is made of chlorosulfonated polyethylene rubber material, which has good physical and mechanical properties, and is resistant to oil, heat, sunlight, ozone, acid and alkali.

[0100] The raw materials for preparing chlorosulfonated polyethylene rubber material include the following components in parts by weight:

[0101] 120 parts of chlorosulfonated polyethylene

[0102] 40 parts of core-shell structure nanocomposite filler

[0103] 20 parts of high wear-resistant carbon black

[0104] 5 parts of magnesium oxide

[0105] Plasticizer (epoxidized cashew nut shell oil) 5 parts

[0106] 2 parts of nano-silica aerogel particles

[0107] 1 part of rare earth complex activator (lanthanum laurate)

[0108] 1 part accelerator

[0109] 1 part of antioxidant (2,6-di-tert-butyl-4-methylphenol)

[0110] 0.5 parts of scorch retarder (N,N'-di(β-naphthyl)-p-phenylenediamine)

[0111] 0.5 parts of metal passivator

[0112] 0.5 parts of crosslinking agent

[0113] 0.5 parts of stearic acid

[0114] 2 parts of wax processing aid (chlorinated paraffin).

[0115] The preparation steps of chlorosulfonated polyethylene rubber are as follows:

[0116] Step 1: First, knead chlorosulfonated polyethylene, rare earth complex activator, magnesium oxide, and stearic acid for 5 minutes at 80°C;

[0117] Step 2: Add core-shell structure nanocomposite filler, high wear-resistant carbon black, nano-silica aerogel particles, plasticizer, and wax processing aid, and mix for 12 minutes at a temperature of 110°C;

[0118] Step 3: Cool down to 60°C, add accelerator, anti-scorch agent, antioxidant, metal passivator, and cross-linking agent, mix well and then produce sheets;

[0119] Curing conditions: one-stage curing at 150°C x t 90 +10% time, second stage vulcanization 100℃×4h.

[0120] In the core-shell structure nanocomposite filler, the core is modified nano-kaolin and the shell is a two-dimensional nanosheet material, the two-dimensional nanosheet material is graphene oxide, and the mass ratio of the two-dimensional nanosheet to the modified nano-kaolin is 1:5. The preparation steps of the core-shell structure nanocomposite filler are as follows:

[0121] 1) Reflux the nano-kaolin in a silane coupling agent KH-550 ethanol solution for 3 hours;

[0122] 2) The graphene oxide dispersion was mixed with the product obtained in step 1), ultrasonically treated for 60 min, and then ball-milled to a particle size of D after drying. 50 =5μm.

[0123] The specific surface area of ​​nano-silica aerogel particles is 600m 2 / g, the surface is modified with hexamethyldisilazane, and the crosslinking agent is di-tert-butyl diisopropylbenzene peroxide.

[0124] The accelerator is prepared by mixing accelerator DM, accelerator M and accelerator D in a mass ratio of 1:1:1.

[0125] The aramid braid layer 3 utilizes eight 1100D aramid fibers woven at a 40° cross-angle into a diamond-shaped grid structure. These aramid fibers are bundled and then woven onto the outer surface of the cable core using a braiding machine. When the cable is wound and bent, the longitudinal tensile stress on the curved cable core surface is greater. This grid structure disperses the bending and tensile forces, allowing the cable core and sheath to contract synchronously, preventing separation between the inner and outer layers. This increases the cable's fatigue resistance and bending life, contributing to its long-term use.

[0126] Before cabling, the cable core 4 is first coated with talcum powder and then wrapped with a water-blocking tape to reduce friction and contact areas between components in the cable core. Then, an aramid braided layer 3 is woven outside the water-blocking tape.

[0127] The mesh number of the talcum powder is 1400 mesh and the particle size is 45μm, which can ensure the uniformity and stability of the talcum powder during the filling process. The water-blocking tape can fully improve the water-blocking performance of the cable.

[0128] The triangular filler 5 includes four groups of aramid fiber bundles, one of which is located in the center, and the other three groups are symmetrically distributed at 120 degrees to form a triangular support. The four groups of aramid fiber bundles are filled with rubber material, and the triangular filler 5 is located in the center of the cable core 4. The aramid fiber bundles serve as a reinforcing core, which further improves the tensile performance of the cable. Less filling material can be used to meet the tensile performance of the cable, and the cable cross-sectional space can be efficiently utilized, making the cable smaller in diameter, lighter in weight, and more compact in internal units. It is beneficial to maintain the stability of the cable cross-sectional shape, avoid wrinkles or flattening when bending, and ensure smooth sliding during dragging. It is beneficial to reduce internal wear, isolate each unit and fix their relative position, prevent friction damage caused by vibration and bending during operation, and reduce the risk of short circuits. It has the characteristics of low temperature resistance (-40℃) and salt spray corrosion resistance, and cooperates with the cable sheath for protection, adapting to high humidity and low temperature environments on lakes and at sea.

[0129] Conductor 7 is constructed from multiple strands of annealed tinned copper monofilaments. Its composition, performance, and appearance must comply with GB / T3956. Conductor 7 has a smooth surface, free of burrs, sharp edges, protrusions, or broken monofilaments. Its resistance meets the requirements of GB / T3956. The monofilament tolerance is ±0.002mm, and the monofilaments are closely spaced. This ensures uniform stress distribution during pulling, minimizing the risk of breakage and distributing the tension.

[0130] The conductor shield 8 has a thickness of 0.4 mm and a shield resistivity of 800 Ω·m, which neutralizes the irregularities on the surface of the conductor 7 and plays a role in balancing the electric field.

[0131] The insulation 9 is made of high-purity ethylene propylene rubber material, with an average thickness not less than the nominal thickness and a thickness at the thinnest point not less than 90%-0.1 of the nominal thickness.

[0132] The insulating shield 10 has a thickness of 0.4 mm, a shield resistivity of 400 Ω·m, and a peeling force of 10 N, and is used to balance the external electric field.

[0133] The braided shield 11 is made of a mixture of aramid fiber and tinned copper wire (tin layer thickness 2μm), with a braiding angle of 45°, a braiding coverage of 80%, and aramid fiber accounting for 70%. It can well protect the internal conductor and insulation from damage, and has the advantages of high strength, chemical corrosion resistance, acid and alkali resistance, wear resistance, and non-oxidation. It can meet the electrical performance required for shielding for a long time.

[0134] Ground conductor 13 and conductor 7 have different diameters, with conductor 7 having a larger diameter than ground conductor 13. Ground conductor 13 is constructed from multiple strands of annealed tinned copper monofilaments. Its composition, performance, and appearance must comply with the requirements of GB / T3956. Ground conductor 13 has a smooth surface, free of burrs, sharp edges, protrusions, or broken monofilaments, and its resistance meets the requirements of GB / T3956. The monofilament tolerance is ±0.002mm, and the monofilaments are closely spaced. This ensures that the monofilaments of ground conductor 13 are evenly stressed during pulling, reducing the risk of breakage and distributing the tension.

[0135] The insulating layer 14 is made of high-purity EPDM material, with an average thickness not less than the nominal thickness and a thickness at the thinnest point not less than 90% - 0.1 of the nominal thickness. The insulating layer 14 and the insulation 9 are made of the same material but with different thicknesses.

[0136] A method for preparing a towing cable for a salt lake water mining vessel comprises the following steps:

[0137] (1) The conductor 7 and the ground conductor 13 are respectively formed by twisting a plurality of annealed tinned copper monofilaments;

[0138] (2) a conductor shield 8, an insulation 9, an insulation shield 10, and a braided shield 11 are sequentially formed outside the conductor 7 to obtain a main line unit 6;

[0139] An insulating layer 14 is extruded outside the ground conductor 13 to obtain a ground unit 12;

[0140] (3) Arrange four groups of aramid fiber bundles as required and extrude rubber material to obtain a triangular filling piece 5. Then, place three main line units 6 in the three grooves of the triangular filling piece 5 respectively. Set a ground line unit 12 between every two adjacent main line units 6 to ensure that the triangular filling piece 5 is located in the center position. After the arrangement is completed, cable is formed. Before cable formation, the cable core 4 is first coated with talcum powder, and then wrapped with a water-blocking tape to form a cable. Then, an aramid braided layer 3 is woven on the outside of the water-blocking tape.

[0141] (4) The inner sheath 2 and the outer sheath 1 are co-extruded outside the aramid braided layer 3.

[0142] Parts or structures not specifically described in the present invention may be adopted from existing technologies or existing products and will not be described in detail here. The above description is only an embodiment of the present invention and does not limit the scope of the patent of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification, or directly or indirectly applied to other related technical fields, are also included in the scope of patent protection of the present invention.

Claims

1. A salt lake water mining ship towing cable, characterized in that: The cable comprises an outer sheath, an inner sheath, an aramid braided layer and a cable core, which are sequentially arranged from the outside to the inside. The cable core comprises: Triangular filler, filled in the center of the cable core; There are several main line units, distributed around the periphery of the triangular filling piece; There are several ground line units in total, and at least one ground line unit is set between every two adjacent main line units.

2. A salt lake water mining vessel towing cable according to claim 1, characterized in that: The thickness of the outer sheath is 2.5-5 mm, the thickness of the inner sheath is 2-3 mm, and both the outer sheath and the inner sheath are made of chlorosulfonated polyethylene rubber material.

3. A salt lake water mining vessel towing cable according to claim 2, characterized in that: The raw materials for preparing the chlorosulfonated polyethylene rubber material include the following components in parts by weight: 80-120 parts of chlorosulfonated polyethylene 40-70 parts of core-shell structure nanocomposite filler 20-30 parts of high wear-resistant carbon black 5-15 parts of magnesium oxide 5-15 parts plasticizer 2-5 parts of nano-silica aerogel particles 1-5 parts of rare earth complex activator 1-3 parts of accelerator 1-3 parts antioxidant 0.5-2 parts of anti-scorching agent 0.5-2 parts of metal passivator 0.5-2 parts crosslinking agent 0.5-1.5 parts of stearic acid 2-5 parts of wax processing aids.

4. A salt lake water mining vessel towing cable according to claim 3, characterized in that: In the core-shell structure nanocomposite filler, the core is modified nano-kaolin and the shell is a two-dimensional nanosheet material, wherein the two-dimensional nanosheet material is graphene oxide or Ti3C2T x MXene, the mass ratio of the two-dimensional nanosheets to the modified nano-kaolin is 1:5-20.

5. The salt lake water mining vessel towing cable according to claim 3, characterized in that: The specific surface area of ​​the nano-silica aerogel particles is ≥600m 2 / g, the surface was modified with hexamethyldisilazane.

6. The salt lake water mining vessel towing cable according to claim 1, characterized in that: The aramid braided layer is made of 2-8 1100D aramid fiber yarns woven into a diamond grid structure at a crossing angle of 40°-50°.

7. The salt lake water mining vessel towing cable according to claim 1, characterized in that: The triangular filling piece includes a plurality of fiber bundles, and the fiber bundles are connected into one body by rubber material.

8. The salt lake water mining vessel towing cable according to claim 1, characterized in that: There are three main line units, all distributed around the triangular filling piece. Each main line unit includes a conductor and a conductor shield, insulation, insulation shield, and braided shield arranged on the outside of the conductor from the inside to the outside.

9. The salt lake water mining vessel towing cable according to claim 1, characterized in that: Each of the ground wire units includes a ground wire conductor and an insulating layer extruded outside the ground wire conductor.

10. The method for preparing a towing cable for a salt lake water mining vessel according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) The conductor and the ground conductor are respectively made of multiple strands of annealed tinned copper monofilaments twisted together; (2) making conductor shielding, insulation, insulation shielding, and braided shielding on the outside of the conductor in sequence to obtain a main line unit; Extruding an insulating layer on the outside of the ground wire conductor to obtain a ground wire unit; (3) Prepare a triangular filler, then place the three main line units in the three grooves of the triangular filler respectively, and set a ground line unit between every two adjacent main line units to ensure that the triangular filler is located in the center position. After the arrangement is completed, the cable is made. Before the cable is made, the cable core is first coated with talcum powder, and then wrapped with a water-blocking tape to make the cable. After that, an aramid braided layer is woven on the outside of the water-blocking tape; (4) An inner sheath and an outer sheath are co-extruded outside the aramid braided layer.

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