Preparation method of electrically heated liquid cargo transfer hose

Abstract

This invention relates to a method for preparing an electrically heated liquid cargo transfer hose. The prepared electrically heated liquid cargo transfer hose consists of an inner layer, an electrically heated layer, an outer layer, and an armor layer. The preparation method includes: (1) calendering of a film, (2) calendering of a rubber cloth, (3) forming of the inner rubber layer, (4) forming of the skeleton layer, (5) forming of a conductive copper braided strip, (6) forming of a spiral steel wire layer, (7) forming of a heated cable layer, (8) filling of the heated cable layer, (9) forming of the outer rubber layer, (10) product vulcanization, and (11) installation of the armor. The electrically heated liquid cargo transfer hose prepared by the method of this invention can transport various fuels such as diesel, fuel oil, and jet fuel in low-temperature environments. Furthermore, the hose is lightweight, has good bending performance, high pressure resistance, high tensile strength, good electrical conductivity, good wear resistance, resistance to marine environments, and good sealing performance. It can be used for the transfer of liquid cargo materials such as oil and fresh water in extremely low-temperature environments such as ice zones and polar regions.

Description

Technical Field

[0001] This invention relates to a method for preparing a liquid cargo transport hose, specifically a method for preparing an electrically heated liquid cargo transport hose. The hose prepared by this method can be used to transport liquid materials in low-temperature environments such as ice zones and polar regions. Background Technology

[0002] Liquefied cargo transport hoses in cold northern regions and even polar areas must be able to continuously transport liquid materials such as oil and fresh water even under low-temperature conditions. Without insulation, the heat from the liquid inside the pipe will dissipate rapidly in low-temperature environments, causing the temperature to drop. When the temperature falls below the freezing point, the liquid will stop flowing and normal transport will cease. Embedding a heating cable inside the pipe can significantly improve the performance of the hose in low-temperature environments, but currently the minimum operating temperature for hoses is -40°C. Lower temperatures place higher demands on the cold resistance and freeze protection of the equipment. Commonly used rubber hoses are prone to embrittlement and reduced oil resistance when used at -40°C and lower temperatures. The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a low-temperature resistant and oil-resistant electrically heated rubber hose. The hose prepared by this method can transport liquid materials such as oil and fresh water in extremely low-temperature environments such as ice zones and polar regions. Summary of the Invention

[0003] The purpose of this invention is to overcome the defects of existing rubber hoses, such as embrittlement and reduced oil resistance, when used at -40℃ and lower temperatures. It provides a method for preparing a low-temperature resistant and oil-resistant electrically heated rubber hose. The hose prepared by this method has a heating cable wound around its wall. During liquid transport, the heating cable heats the hose, maintaining a certain temperature within the pipeline and preventing condensation of the liquid during transport in low-temperature environments. This allows for the transport of liquid materials such as oil and fresh water in extremely low-temperature environments such as ice zones and polar regions.

[0004] To achieve the above objectives, the technical solution of the present invention is: a method for preparing an electrically heated liquid cargo transfer hose, wherein the prepared electrically heated liquid cargo transfer hose comprises an inner layer, an electrically heated layer, an outer layer, and an armor layer, and the preparation method includes:

[0005] (1) Calendering of film: The rubber compound must be hot-mixed evenly, and rubber compounds with different properties must not be interchanged or mixed; the calendered film should be cooled in time and rolled up with a clean pad, and the rolling speed should be consistent with the calendering speed.

[0006] (2) Rubber sheet calendering: The rubber material is squeezed into the cord through two rollers and a rubber sheet of a certain thickness is formed above and below the cord. The calendered rubber sheet is cooled and then wound up.

[0007] (3) Inner rubber layer forming: First, wipe the surface of the stainless steel mandrel that matches the inner diameter of the hose clean, apply a layer of release agent to the mandrel, and spirally wind and stack 3 layers of calendered rubber on the surface of the mandrel to achieve the required thickness. The winding should be flat and wrinkle-free, and there should be no gaps. The cumulative diameter should reach the required outer diameter range. The calendered rubber is then cut into widths on a cutting machine. The width of the rubber is 80-100mm and the thickness is 0.7mm.

[0008] (4) Skeleton layer forming:

[0009] For the inner curtain wrapping layer, use adhesive-coated curtain fabric, wrapping two layers crosswise. The wrapping should be flat and wrinkle-free, with an overlap of 3-5mm. The thicker adhesive side of the curtain fabric should face inwards, and the cumulative diameter should reach the outer diameter range required by the process.

[0010] For the outer curtain wrapping layer, use adhesive-coated curtain fabric, cross-wrap four layers, the wrapping should be flat and wrinkle-free, with an overlap of 3-5mm, the thicker adhesive side of the curtain fabric should be the inner adhesive layer, and the cumulative diameter should reach the outer diameter range required by the process.

[0011] The intermediate rubber layer is formed, and the calendered film is cut into widths on a slitting machine. The film width is 80-100mm and the thickness is 1.0mm.

[0012] (5) Forming of conductive copper braided tape: 1.5 square meters of purple copper braided tape is used for conductive copper braided tape, and the conductive wires are wound according to the angle of the curtain winding layer;

[0013] (6) Spiral steel wire layer forming: The steel wire is made of 5.0mm diameter stainless steel wire. The surface of the steel wire is cleaned before use. It is wound evenly according to the winding pitch required by the process, with a winding width tolerance of 1mm. The wound surface should be flat after winding.

[0014] (7) Forming of heat tracing cable layer: The heat tracing cable adopts 220V self-limiting temperature cable. Before use, the conductivity of the cable should be tested. The cable should be wound evenly according to the winding pitch required by the process. During the winding process, sharp objects should not be used to puncture the cable to prevent damage.

[0015] (8) Filling the heat tracing cable layer: Fill the heat tracing cable layer with filler glue; wrap the outer layer with a layer of curtain fabric for protection;

[0016] (9) Outer adhesive layer forming: Two layers of calendered adhesive film are spirally wound and superimposed on the outside of the outer cord fabric winding layer to achieve the required thickness. The winding should be flat and wrinkle-free, and the winding should be seamless. The cumulative diameter should be within the range of the required outer diameter.

[0017] (10) Product vulcanization: A special vulcanizing film is applied in straight strips to the outer rubber layer of the hose. A 110mm wide nylon water cloth is wrapped around the water cloth tray. The water cloth must be clean and free of impurities. Soak it in water once to ensure that the water cloth is fully soaked. Clean the work area of ​​the forming machine's traveling carriage. Then, wrap the nylon water cloth around the equipment and wrap two layers around the pipe body. The distance between the water cloth joints should not be less than 1m. Open the steam inlet valve and send steam into the vulcanizing tank. When the temperature reaches 143℃, start calculating the positive vulcanization time. The vulcanization temperature is controlled between 143±2℃.

[0018] (11) Install the armor: After the hose is vulcanized, insert one end into the armor inlet and pull it from the other end until the armor is installed.

[0019] Furthermore, for film calendering: the interval between hot-refined rubber and pressing should not exceed 10 minutes, and the weight of the film roll should not exceed 15 kg. If the interval is exceeded, the hot refining should be carried out again. After starting the machine, steam should be introduced and the steam pipeline valves should be adjusted so that the surface temperature of the roller reaches the temperature shown in the table below before the film calendering operation can be carried out.

[0020] Furthermore, during the calendering process, the temperature of the upper roller should be controlled at 65–80°C, the middle roller at 70–85°C, and the lower roller at 70–85°C. The film rolls should be neatly arranged and appropriately tensioned, and stored in the designated storage area.

[0021] Furthermore, the calendering of the rubber sheet: Calendering control parameters: speed 650-700 rpm, cooling winding machine speed 300-350 rpm, upper roller temperature 80-95 degrees Celsius, middle and side roller reference temperature 80-90 degrees Celsius, lower roller temperature 110-135 degrees Celsius. The calendered rubber sheet is wound up after cooling. The padding cloth should be clean and tidy. The rubber sheet is wound up neatly and with appropriate tension. The temperature inside the rubber sheet roll should not exceed 40 degrees Celsius.

[0022] Further, the outer rubber layer is formed: the calendered rubber sheet is cut into widths on a slitting machine. The width of the outer rubber sheet for DN65 hose is 80-100mm and the thickness is 0.85mm, while the width of the outer rubber sheet for DN150 hose is 120-150mm and the thickness is 0.9mm.

[0023] Furthermore, the outer adhesive layer after wrapping should be flat and wrinkle-free, with no gaps. A third adhesive layer is wrapped around the outside of the second adhesive layer. The width of the third adhesive layer is 4-6 mm larger than that of the second adhesive layer, and the material of the third adhesive layer is 1670 type polyester cord fabric. The wrapping direction of the third adhesive layer is opposite to that of the second adhesive layer.

[0024] The beneficial effects of this invention are:

[0025] The electrically heated liquid cargo transfer hose prepared by the method of this invention can transport various fuels such as diesel, fuel oil, and jet fuel in low-temperature environments. Furthermore, the hose prepared by this invention is lightweight, has good bending performance, high pressure resistance, high tensile strength, good electrical conductivity, good wear resistance, resistance to marine environments, and good sealing performance. Because a heating cable is wound around the pipe wall, the hose is heated by the heating cable, maintaining a certain temperature in the pipeline and preventing condensation of the liquid during transport in low-temperature environments. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the electrically heated liquid cargo transfer hose prepared by the preparation method of the present invention;

[0027] In the diagram: 1. Inner adhesive layer, 2. Adhesive-coated polyester fabric, 3. Adhesive, 4. Conductive copper wire, 5. Spiral steel wire, 6. Adhesive filler, 7. Adhesive, 8. Adhesive-coated polyester fabric, 9. Heating cable, 10. Adhesive, 11. Adhesive-coated polyester fabric, 12. Outer adhesive layer, 13. Armor. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] The electrically heated liquid cargo transfer hose structure prepared by the method of the present invention, such as... Figure 1 As shown, it can be used for liquid cargo transportation in low-temperature environments such as ice zones and polar regions.

[0030] The structure of the electrically heated liquid cargo transfer hose consists of an inner layer, an electrically heated layer, an outer layer, and an armor layer.

[0031] The electrically heated liquid cargo transfer hose includes an inner rubber layer 1, an adhesive polyester fabric 2, adhesive 3, a static-dissipating copper wire 4, a spiral steel wire 5, an adhesive filler 6, adhesive 7, an adhesive polyester fabric 8, a heating cable 9, adhesive 10, an adhesive polyester fabric 11, an outer rubber layer 12, and an armor 13.

[0032] The method for preparing the electrically heated liquid cargo transfer hose of the present invention includes:

[0033] (1) Film Calendering: The rubber compound must be hot-mixed uniformly. Different types of rubber compounds with varying properties must not be interchanged or mixed. The interval between hot-mixed rubber compound and sheeting should not exceed 10 minutes, and the film roll weight should not exceed 15 kg. If the interval is exceeded, the compound should be hot-mixed again. After starting the machine, introduce steam and adjust the steam pipeline valves to ensure the roller surface temperature reaches the temperatures shown in the table below before calendering. During calendering, control the upper roller temperature to 65-80°C, the middle roller temperature to 70-85°C, and the lower roller temperature to 70-85°C. The calendered film should be cooled promptly and wound up with a clean padding cloth. The winding speed should be consistent with the calendering speed. The film rolls should be neat, with appropriate tension, and stored in the designated storage area.

[0034] (2) Rubber Sheet Calendering: The rubber material is squeezed into the cord through two rollers, forming a sheet of a certain thickness on the upper and lower parts of the cord. Calendering control parameters: speed 650-700 rpm, cooling winding machine speed 300-350 rpm. Upper roller temperature 80-95 degrees Celsius, middle and side roller reference temperature 80-90 degrees Celsius, lower roller temperature 110-135 degrees Celsius. After cooling, the calendered rubber sheet is wound up. The backing cloth should be clean and tidy, and the rubber sheet should be wound neatly with appropriate tension. The temperature inside the rubber sheet roll should not exceed 40 degrees Celsius.

[0035] (3) Inner rubber layer forming: First, clean the surface of the stainless steel mandrel that matches the inner diameter of the hose, and apply a layer of release agent to the mandrel. Spiral-wrap and stack three layers of calendered rubber sheet on the surface of the mandrel to achieve the required thickness. The winding should be smooth and wrinkle-free, with no gaps, and the cumulative diameter should be within the required outer diameter range. The calendered rubber sheet is then cut to width on a slitting machine. The width of the rubber sheet is 80-100mm, and the thickness is 0.7mm.

[0036] (4) Skeleton layer forming:

[0037] For the inner curtain winding layer, use 1670dtex / 2 adhesive-coated fabric, wrapped in two layers in a cross-cut pattern. The wrapping should be smooth and wrinkle-free, with an overlap of 3-5mm. The thicker adhesive side of the fabric should face inwards, and the cumulative diameter should meet the outer diameter requirements of the process. For the outer curtain winding layer, use 1670dtex / 2 adhesive-coated fabric, wrapped in four layers in a cross-cut pattern. The wrapping should be smooth and wrinkle-free, with an overlap of 3-5mm. The thicker adhesive side of the fabric should face inwards, and the cumulative diameter should meet the outer diameter requirements of the process.

[0038] Intermediate layer forming: The calendered film is cut into widths on a slitting machine, with a width of 80-100mm and a thickness of 1.0mm.

[0039] (5) Forming of conductive copper braided tape: 1.5 square meters of purple copper braided tape is used for conductive copper braided tape, and the conductive wires are wound according to the angle of the curtain winding layer;

[0040] (6) Spiral steel wire layer forming: The steel wire is made of 5.0mm diameter stainless steel wire. The surface of the steel wire is cleaned before use. The wire is wound evenly according to the winding pitch required by the process, with a winding width tolerance of 1mm. The wire should be flat after winding.

[0041] (7) Forming of the heat tracing cable layer: The heat tracing cable is a 220V self-regulating cable. The conductivity of the cable should be tested before use. The cable should be wound evenly according to the winding pitch required by the process. During the winding process, sharp objects should not be used to puncture the cable to prevent damage.

[0042] (8) Filling the heat tracing cable layer: Fill the heat tracing cable layer with filler glue; wrap the outer layer with a layer of curtain cloth for protection.

[0043] (9) Outer Rubber Layer Forming: Two layers of calendered rubber sheet are spirally wound and superimposed on the outside of the outer cord fabric winding layer to achieve the required thickness. The winding should be smooth and wrinkle-free, with no gaps, and the cumulative diameter should be within the required outer diameter range. The calendered rubber sheet is then cut to width on a slitting machine. The width of the outer rubber sheet for DN65 hose is 80-100mm, and the thickness is 0.85mm. The width of the outer rubber sheet for DN150 hose is 120-150mm, and the thickness is 0.9mm.

[0044] The outer adhesive layer after wrapping should be flat and wrinkle-free, with no gaps. A third adhesive layer is wrapped around the outside of the second adhesive layer. The width of the third adhesive layer is 4-6 mm larger than that of the second adhesive layer, and the material of the third adhesive layer is 1670 type polyester cord fabric. The wrapping direction of the third adhesive layer is opposite to that of the second adhesive layer.

[0045] (10) Product vulcanization: A special vulcanizing film is applied in straight strips to the outer rubber layer of the hose. A 110mm wide nylon water-resistant cloth is wrapped around the water-resistant cloth tray. The water-resistant cloth must be clean and free of impurities. Soak it in water once to ensure that the water-resistant cloth is completely soaked. Clean the work area of ​​the forming machine's traveling carriage, and then wrap the nylon water-resistant cloth around the equipment, wrapping two layers around the pipe body. The spacing between the water-resistant cloth joints should be no less than 1m.

[0046] Open the steam inlet valve to introduce steam into the vulcanizing tank. When the temperature reaches 143℃, start calculating the positive vulcanization time. The vulcanization temperature is controlled between 143±2℃.

[0047] (11) Install the armor: After the hose is vulcanized, insert one end into the armor inlet and pull it from the other end until the armor is installed.

[0048] The method of the present invention uses a fully automatic intelligent internal mixer to mix the rubber compound, and the raw materials are prepared using a multi-station intelligent automatic batching system.

[0049] The hose produced by the method of this invention uses hydrogenated nitrile butadiene rubber (NBR) as the main material for the inner rubber layer, which exhibits good oil resistance and flexibility, as well as excellent anti-extrusion performance under high pressure. Furthermore, before using the hydrogenated NBR produced in this invention, semi-reinforcing carbon black with good reinforcing and resilience is added to the rubber compound to improve its physical and mechanical properties. Metal oxides and peroxides are used as the vulcanization accelerator system, and a plasticizer with good cold resistance is used as the softening system, resulting in thorough treatment of the rubber compound. In addition, an adhesive is added as an auxiliary material to ensure the bonding performance of the inner rubber layer, thus guaranteeing both the physical and mechanical properties of the rubber compound and its adhesive properties.

[0050] After numerous tests and verifications, the inner rubber layer's resistance to media, isooctane extraction properties, and physical properties all meet very high requirements. Solubility is achieved at less than 3%, a level unattainable by existing hoses used for oil transportation.

Claims

1. A method for preparing an electrically heated liquid cargo transfer hose, wherein the prepared electrically heated liquid cargo transfer hose comprises an inner layer, an electrically heated layer, an outer layer, and an armor layer, characterized in that, The preparation method includes: (1) Calendering of film: The rubber compound must be hot-mixed evenly. Different rubber compounds with different properties must not be interchanged or mixed. The calendered film should be cooled in time and rolled up with a clean pad. The rolling speed should be consistent with the calendering speed. (2) Rubber sheet calendering: The rubber material is squeezed into the cord through two rollers and a rubber sheet of a certain thickness is formed above and below the cord. The calendered rubber sheet is cooled and then wound up. (3) Inner rubber layer molding: First, wipe the surface of the stainless steel mandrel that matches the inner diameter of the hose clean, apply a layer of release agent to the mandrel, and spirally wind and stack 3 layers of calendered rubber on the surface of the mandrel to achieve the required thickness. The winding should be flat and wrinkle-free, and there should be no gaps. The cumulative diameter should reach the required outer diameter range. The calendered rubber is then cut into widths on a cutting machine. The width of the rubber is 80-100mm and the thickness is 0.7mm. (4) Skeleton layer forming: For the inner curtain wrapping layer, use adhesive-coated curtain fabric, wrapping two layers crosswise. The wrapping should be smooth and wrinkle-free, with an overlap of 3-5mm. The thicker adhesive side of the curtain fabric should face inwards, and the cumulative diameter should reach the outer diameter range required by the process. For the outer curtain wrapping layer, use adhesive-coated curtain fabric, cross-wrap four layers, the wrapping should be flat and wrinkle-free, with an overlap of 3~5mm, the thicker adhesive side of the curtain fabric should be the inner adhesive layer, and the cumulative diameter should reach the outer diameter range required by the process. The intermediate rubber layer is formed, and the calendered film is cut into widths on a slitting machine. The film width is 80-100mm and the thickness is 1.0mm. (5) Forming of conductive copper braided tape: 1.5 square meters of purple copper braided tape is used for conductive copper braided tape, and the conductive wires are wound according to the angle of the curtain winding layer; (6) Spiral steel wire layer forming: The steel wire is made of stainless steel wire with a diameter of 5.0mm. Before use, the steel wire is cleaned and wound evenly according to the winding pitch required by the process. The winding width tolerance is 1mm. After winding, it should be flat. (7) Forming of heat tracing cable layer: The heat tracing cable adopts 220V self-limiting temperature cable. Before use, the conductivity of the cable should be tested. The cable should be wound evenly according to the winding pitch required by the process. During the winding process, sharp objects should not be used to puncture the cable to prevent damage. (8) Filling the heat tracing cable layer: Fill the heat tracing cable layer with filler glue; wrap the outer layer with a layer of curtain fabric for protection; (9) Outer adhesive layer forming: Two layers of calendered adhesive film are spirally wound and superimposed on the outside of the outer cord fabric winding layer to achieve the required thickness. The winding should be flat and wrinkle-free, and the winding should be seamless. The cumulative diameter should be within the range of the required outer diameter. (10) Product vulcanization: A special vulcanizing film is applied to the outer rubber layer of the hose in straight strips. A 110mm wide nylon water cloth is wrapped around the water cloth tray. The water cloth must be clean and free of impurities. Soak it in water once to ensure that the water cloth is fully soaked. Clean the work area of ​​the molding machine's traveling carriage. Then, wrap the nylon water cloth around the equipment and wrap it around the pipe body twice. The distance between the water cloth joints should not be less than 1m. Open the steam inlet valve and send steam into the vulcanizing tank. When the temperature reaches 143℃, start calculating the positive vulcanization time. The vulcanization temperature is controlled between 143±2℃. (11) Install the armor: After the hose is vulcanized, insert one end into the armor inlet and pull it from the other end until the armor is installed.

2. The method for preparing the electrically heated liquid cargo transfer hose according to claim 1, characterized in that: Film calendering: The interval between hot-refined rubber compound and sheeting should not exceed 10 minutes, and the weight of the film roll should not exceed 15 kg. If the interval is exceeded, the compound should be hot-refined again. After starting the machine, steam should be introduced and the steam pipeline valves should be adjusted so that the surface temperature of the roller reaches the temperature shown in the table below before the film calendering operation can be carried out.

3. The method for preparing the electrically heated liquid cargo transfer hose according to claim 2, characterized in that: During the calendering process, the temperature of the upper roller should be controlled at 65~80℃, the temperature of the middle roller at 70~85℃, and the temperature of the lower roller at 70~85℃. The film rolls should be neat and appropriately tight, and stored in the storage area.

4. The method for preparing the electrically heated liquid cargo transfer hose according to claim 1, characterized in that: Rubber sheet calendering: Calendering control parameters: speed 650-700 rpm, cooling winding machine speed 300-350 rpm, upper roller temperature 80-95℃, middle and side roller reference temperature 80-90℃, lower roller temperature 110-135℃. The calendered rubber sheet is wound up after cooling. The padding cloth should be clean and tidy. The rubber sheet is wound up neatly and with appropriate tension. The temperature inside the rubber sheet roll should not exceed 40℃.

5. The method for preparing the electrically heated liquid cargo transfer hose according to claim 1, characterized in that: Outer rubber layer forming: The calendered rubber sheet is cut to width on a slitting machine. The width of the outer rubber sheet for DN65 hose is 80-100mm and the thickness is 0.85mm. The width of the outer rubber sheet for DN150 hose is 120-150mm and the thickness is 0.9mm.

6. The method for preparing the electrically heated liquid cargo transfer hose according to claim 5, characterized in that: The outer adhesive layer after wrapping should be flat and wrinkle-free, with no gaps. A third adhesive layer is wrapped around the outside of the second adhesive layer. The width of the third adhesive layer is 4-6 mm larger than that of the second adhesive layer, and the material of the third adhesive layer is 1670 type polyester cord fabric. The wrapping direction of the third adhesive layer is opposite to that of the second adhesive layer.

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