JP5184176B2 - Flexible tube for cryogenic fluid transport - Google Patents

Description

  The present invention relates to a flexible tube for transporting a cryogenic fluid used for transporting a fluid such as liquefied natural gas having a cryogenic temperature from an offshore floating facility installed on the sea to a tanker or the like.

  Conventionally, floating oil facilities and tankers, etc., have been used floating floating facilities and tankers in order to load them into transport tankers from offshore floating facilities (bases) that store oil calculated from offshore oil fields, etc. Are connected, and oil is transported. As a flexible tube for transporting a fluid at room temperature such as petroleum, a resin tube is usually used. As such a resin-made flexible tube for transporting fluid, there is a flexible fluid-transporting tube having a reinforcing layer, a heat insulating layer, a waterproof layer, and the like on the outer peripheral portion of the resin-made inner tube (Patent Document 1).

On the other hand, natural gas calculated from a gas field on the ground or in the near sea is liquefied and stored at the base. When loading liquefied natural gas (hereinafter “LNG”) onto a tanker for transportation, an articulated loading arm or the like provided at a coastal base is used. As the LNG receiving base, for example, there are an LNG receiving base and an LNG shipping base system described in Patent Document 1 adopting a loading arm system (Patent Document 2).
Japanese Patent Laid-Open No. 5-180375 JP-A-5-65718

  However, although the loading arm method as in Patent Document 2 can be loaded from a ground base into a tanker, the LNG is loaded into a tanker from a floating facility that produces and stores LNG installed in a gas field in the open sea. In this case, there is a problem that the loading arm cannot follow the movement between the facility and the tanker, which are greatly shaken by waves, winds, etc., and the size of the equipment is increased.

  Further, in the conventional method of transporting oil, a method of loading a fluid into a tanker using a resin floating flexible tube as in Patent Document 1 is difficult to cope with a cryogenic fluid such as LNG. There is a problem that. This is because LNG has an extremely low temperature of about -160 ° C, so the conventional resin-type floating flexible tube is brittle at such an extremely low temperature, so that sufficient flexibility cannot be obtained and embrittlement occurs. This is because the flexible tube is broken by the pressure for pumping LNG. Therefore, there is a demand for a flexible tube that has both durability and heat insulation that can be used even at extremely low temperatures, but there is no floating flexible tube that can use a cryogenic fluid such as LNG for transportation over the sea. There is a problem.

  In particular, in a flexible tube having only a normal heat insulating material, there is a problem that when the fluid leaks inside, the flexible tube may be damaged by the internal pressure of the leaked fluid. Also, when using a flexible tube, temperature distribution may occur in the circumferential direction or length direction of the flexible tube due to the influence of outside air or seawater, or when fluid leaks inside A low temperature part may be formed and a temperature distribution may occur in the flexible tube. In such a case, since a large thermal stress is generated in the resin waterproof layer or the like used for the flexible tube, there is a problem that the flexible tube is deteriorated and the durability of the flexible tube is lowered.

  The present invention has been made in view of such a problem, and is a flexible tube used when a fluid is loaded from a marine floating facility to a tanker, and is suitable for transporting a cryogenic fluid such as LNG. Cryogenic fluid transport that does not break due to internal pressure even when LNG etc. leaks, and that suppresses deterioration of tube durability due to thermal stress due to temperature distribution generated in the flexible tube during use or leakage An object of the present invention is to provide a flexible tube.

  In order to achieve the above-described object, the first invention includes at least a flexible corrugated metal inner tube, a first reinforcing layer provided on an outer peripheral portion of the corrugated metal inner tube, The 1st heat insulation layer provided in the outer peripheral part of the reinforcement layer, the intermediate | middle waterproof layer provided in the outer peripheral part of the said 1st heat insulation layer, and the 2nd reinforcement layer provided in the outer peripheral part of the said intermediate | middle waterproof layer And a second heat insulating layer provided on the outer peripheral portion of the second reinforcing layer, and an external waterproof layer provided on the outer peripheral portion of the second heat insulating layer. It is a flexible tube for fluid transportation.

  It is desirable that a thermal diffusion layer is further provided between at least one of the first heat insulation layer and the intermediate waterproof layer or between the second heat insulation layer and the external waterproof layer.

  Further, a metal tape may be provided on at least one surface of the first heat insulating layer or the second heat insulating layer, and the first heat insulating layer and the second heat insulating layer may be aerobic. It may be a non-woven fabric layer containing gel.

  Here, the airgel is also called airgel or aerogel, which is a substance that is formed into a gel by substituting moisture with gas. It contains air that is approximately 90% or more in volume, and is extremely light and high. A substance having thermal insulation properties. The airgel is produced mainly with, for example, silica, alumina or the like, and is often used as a catalyst or an adsorbent.

  For the first reinforcing layer and the second reinforcing layer, any of polyester fiber woven tape, aramid fiber woven tape, arylate fiber woven tape, ultra-high molecular weight polyethylene fiber woven tape, carbon fiber woven tape, or metal tape is used. The first reinforcing layer is an alternating winding in which the tape is wound clockwise and counterclockwise with respect to the flexible tube, and the second reinforcing layer is the tape, It is desirable that the flexible tube is wound from one direction.

  Here, since a cryogenic fluid, for example, a fluid of about −160 ° C. or less such as LNG is passed through a metal inner tube, the resin fiber tape having a lower thermal conductivity is more thermally insulated than a carbon fiber woven tape or metal tape. Since an effect is acquired, it is preferable. Further, the fiber woven tape is more preferable because it is wound more flexibly around the corrugated metal tube than the metal tape.

  According to the first invention, since the intermediate waterproof layer is provided inside the heat insulating layer, even if a low-temperature fluid flowing inside from the inner pipe leaks, the outer waterproof layer is not reached. In addition, since the local low temperature portion is generated in a part of the outer waterproof layer, the outer waterproof layer does not become brittle. In addition, since a reinforcing layer for circumferential reinforcement is provided outside the intermediate waterproof layer, the intermediate prevention layer may rupture due to, for example, leaked fluid pressure or internal pressure due to pressure when the fluid vaporizes. Absent.

  In particular, a reinforcing layer is provided on the outer periphery of the metal corrugated inner pipe used for the inner pipe. The metal corrugated inner pipe has a possibility that the inner pipe is deformed in the axial direction by the pressure of the internal fluid because the thickness of the pipe is kept to a predetermined thickness in order to maintain flexibility. The first reinforcing layer is intended to suppress deformation of the inner tube in the axial direction. Furthermore, the reinforcing layer has an effect of suppressing radial deformation and an effect of improving creep resistance.

  Further, if a thermal diffusion layer is further provided between the heat insulating layer and the waterproof layer, the temperature distribution due to the portion of the flexible tube can be relaxed. For example, even when a low-temperature fluid leaks inside and the fluid slightly penetrates into the heat insulation layer and a temperature distribution is generated in the heat insulation layer itself, the heat is Since the inside of the thermal diffusion layer is diffused (conducted) in the direction, temperature distribution is unlikely to occur in the flexible tube. For this reason, temperature distribution does not easily occur in the intermediate waterproof layer, and thermal stress generated on the flexible tube due to the temperature portion distribution can be reduced.

  In addition, when a flexible tube is used to transport fluid from a floating facility at sea to a tanker, etc., the flexible tube is normally used in a floating state on the sea, so the circumferential direction or length direction of the flexible tube A part of the sunken in the seawater and a part of it is exposed to the sea. Therefore, the flexible tube has a part exposed to the sea in a cold region, or a part exposed to the sea in a tropical region becomes hot under the hot sun. Then, temperature distribution occurs. However, if a thermal diffusion layer is provided inside the outer waterproof layer, the temperature distribution due to the heat outside the flexible tube can be relaxed, so the thermal stress generated on the flexible tube due to the temperature distribution is reduced. can do. By reducing the thermal stress generated in the flexible tube, the durability of the flexible tube can be improved.

  Further, by using a non-woven fabric containing airgel as the heat insulating layer, a high heat insulating effect can be obtained, the effect of preventing fluid permeation is high, and a very high strength can be obtained.

  2nd invention is provided in the outer peripheral part of the corrugated metal inner pipe which has at least flexibility, the 1st reinforcement layer provided in the outer peripheral part of the said corrugated metal inner pipe, and the said reinforcement layer And a heat diffusion layer provided on the outer periphery of the heat insulation layer, and an external waterproof layer provided on the outer periphery of the heat diffusion layer. It is a flexible tube.

  According to the second invention, since the thermal diffusion layer is provided between the heat insulating layer and the waterproof layer, the temperature distribution due to the portion of the flexible tube can be relaxed. For example, when a flexible tube is used for transporting a fluid from a floating facility at sea to a tanker or the like, the flexible tube is normally used in a state of floating on the sea. A part of the sunken in the seawater and a part of it is exposed to the sea. Therefore, the flexible tube has a part exposed to the sea in a cold region, or a part exposed to the sea in a tropical region becomes hot under the hot sun. Then, temperature distribution occurs. However, if a thermal diffusion layer is provided inside the outer waterproof layer, the temperature distribution due to the heat outside the flexible tube can be relaxed, so the thermal stress generated on the flexible tube due to the temperature distribution is reduced. can do. By reducing the thermal stress generated in the flexible tube, the durability of the flexible tube can be improved.

  According to the present invention, it is a flexible tube used when a fluid is loaded from an offshore floating facility to a tanker, and is suitable for transporting a cryogenic fluid such as LNG. It is possible to provide a flexible tube for transporting a cryogenic fluid that is prevented from being deteriorated by the thermal stress caused by the temperature distribution generated in the flexible tube at the time of use or leakage. .

  Hereinafter, the flexible tube 1 concerning embodiment of this invention is demonstrated. FIG. 1 is a perspective view showing the configuration of the flexible tube 1, and FIG. 2 is a partial cross-sectional view of the flexible tube 1. The flexible tube 1 is mainly composed of a corrugated tube 3, a floor layer 5, an axial reinforcing layer 7, heat insulating layers 9a and 9b, an intermediate waterproof layer 11, a circumferential reinforcing layer 13, an external waterproof layer 15, and the like. The

  Usually, in consideration of fluid transportation efficiency, a tanker of 100,000 to 150,000 tons class is used as a tanker used for fluid transportation at sea. In addition, since the weather varies greatly on the sea, it is desirable that the operation of loading a fluid into a tanker or the like is usually completed within 24 hours. Therefore, considering the loading efficiency, when the fluid velocity is 5 m / sec, several flexible tubes 1 having a diameter of about 400 mm to 500 mm are used simultaneously. However, the diameter of the flexible tube 1 is desirably larger in order to increase the fluid transportation efficiency, but the allowable bending radius of the flexible tube 1 is increased, and the laying device of the flexible tube 1 is increased in size. The diameter of the flexible tube 1 is appropriately determined according to usage conditions and the like.

  The innermost layer of the flexible tube 1 is provided with a corrugated tube 3 as an inner tube. When the flexible tube 1 is used, a fluid (hereinafter described as a flow of LNG) flows through the corrugated tube 3. The corrugated tube 3 is a flexible tube, has a certain degree of strength, and has excellent low-temperature resistance. That is, it is preferable to use a material that can maintain flexibility even when a cryogenic fluid such as LNG flows therein, and is less likely to crack or crack. The corrugated tube 3 is, for example, a metal corrugated tube, and preferably a stainless bellows tube. It should be noted that instead of the corrugated tube 3, other types of inner tubes can be used as long as they have the same flexibility and excellent low-temperature resistance.

  A floor layer 5 is provided on the outer peripheral portion of the corrugated tube 3. The floor layer 5 is a layer for leveling the irregularities on the outer periphery of the corrugated tube 3 (unevenness due to the corrugated shape), and can be deformed following the flexibility of the corrugated tube 3. That is, the floor layer 5 has a certain thickness and serves as an uneven cushion due to the corrugated shape of the outer periphery of the corrugated tube 3. However, it is not necessary to completely fill the recess. The outer peripheral portion of the corrugated tube 3 is further provided with a reinforcing layer 7 and the like which will be described later. However, it is difficult to wind the reinforcing tape or the like constituting the reinforcing layer 7 due to the unevenness of the outer peripheral surface of the corrugated tube 3. This is to prevent the reinforcing tape from being displaced during use.

  In addition, as the floor layer 5, a nonwoven fabric etc. can be used, for example. Also, if the outer peripheral surface of the inner tube has no large unevenness due to corrugation or the like, or if it has unevenness, it will not adversely affect the reinforcing layer 7 provided on the outer peripheral portion. The floor layer 5 is not necessary.

  An axial reinforcing layer 7 is provided on the outer periphery of the floor layer 5. The axial reinforcing layer 7 can be deformed following the flexibility of the corrugated tube 3 while restraining the corrugated tube 3 from deforming (extending) mainly in the axial direction of the flexible tube 1. For example, when LNG is caused to flow into the corrugated tube 3, an internal pressure of about 1 MPa is generated inside the corrugated tube 3. The corrugated tube 3 can withstand the pressure on the inner peripheral surface of the corrugated tube 3, but the corrugated shape provided in order to obtain flexibility facilitates the internal pressure in the axial direction of the corrugated tube 3. Deforms (stretches). For this reason, the axial reinforcement layer 7 is provided in order to suppress the axial deformation of the corrugated tube 3.

  The axial reinforcing layer 7 is formed of a reinforcing tape such as a fiber tape or a metal tape. As the fiber tape, for example, a polyester fiber woven tape, an aramid fiber woven tape, an arylate fiber woven tape, an ultra high molecular weight polyethylene fiber woven tape, a carbon fiber woven tape, and the like can be used. Moreover, as a metal tape, a stainless steel tape etc. can be used, for example.

  In order to form the axial reinforcing layer 7, a reinforcing tape is wound around the outer circumference of the floor layer 5 at a predetermined pitch. When winding the reinforcing tape, the end portions in the width direction of the reinforcing tape do not need to overlap each other, that is, the winding pitch of the reinforcing tape may be larger than the width of the reinforcing tape. The reinforcing tape is overlapped at least twice and wound around the floor layer 5 so that the winding direction of the first reinforcing tape and the winding direction of the second reinforcing tape are opposite to each other. That is, the respective double-wrapped reinforcing tapes are wound around the outer periphery of the floor layer 5 so as to cross each other (this winding method is referred to as “alternate winding”).

  The reason why the reinforcing tape is wound only from one direction is that when the flexible tube 1 receives a force in the axial direction, a twisting force is generated on the flexible tube 1 according to the winding direction of the reinforcing tape. is there. If necessary, a pressing tape layer of the reinforcing tape (not shown) may be further provided on the outer periphery of the wound reinforcing tape. For example, a non-woven tape can be used as the presser winding layer, and the non-woven tape may be wound around the outer surface of a reinforcing tape that is alternately wound.

  Heat insulation layers 9 a and 9 b are provided on the outer periphery of the axial reinforcing layer 7. The heat insulation layers 9 a and 9 b insulate the LNG flowing in the corrugated tube 3 from the outside of the flexible tube 1 and can be deformed following the flexibility of the corrugated tube 3. That is, the heat of LNG is hardly transmitted to the outer surface of the flexible tube 1. For this reason, the intermediate waterproof layer 11 and the outer waterproof layer 13 that is the outermost layer are not affected by the temperature of the LNG. Similarly, the external temperature of the flexible tube 1 is not transmitted to the LNG, and the LNG is prevented from vaporizing in the flexible tube 1.

  The heat insulating layers 9a and 9b are preferably made of a material having heat insulating properties and excellent liquid permeability. As the heat insulation layer 9a, for example, a non-woven fabric can be used, and a polyester fiber or an inorganic fiber non-woven fabric can be used. Moreover, what made airgel contain to fiber type nonwoven fabrics, such as a polyester fiber nonwoven fabric, can be used. As the airgel, for example, silica-based airgel can be used, and powdered airgel is contained (impregnated) into the nonwoven fabric. Airgel has extremely high heat insulation properties and high load bearing properties.

  An intermediate waterproof layer 11 is provided between the heat insulating layers 9a and 9b. The intermediate waterproof layer 11 prevents the LNG from leaking to the external waterproof layer 15 when the LNG flowing through the corrugated tube 3 leaks. That is, the cryogenic LNG flows to the vicinity of the outer waterproof layer 15, so that the outer waterproof layer 15 is embrittled and damaged, and LNG is prevented from leaking from the flexible tube 1.

  The intermediate waterproof layer 11 is preferably made of resin, and for example, polyethylene can be used.

  A circumferential reinforcing layer 13 is provided between the intermediate waterproof layer 11 and the heat insulating layer 9b. The circumferential reinforcing layer 13 prevents the intermediate waterproof layer 11 from being damaged by the internal pressure of the LNG or the pressure of the LNG when vaporized when the LNG flowing through the corrugated tube 3 leaks. That is, it is a reinforcing layer against pressure in the circumferential direction from the inside of the flexible tube 1.

  The circumferential reinforcing layer 13 is formed of a reinforcing tape such as a fiber tape or a metal tape. As the fiber tape, for example, a polyester fiber woven tape, an aramid fiber woven tape, an arylate fiber woven tape, an ultra high molecular weight polyethylene fiber woven tape, a carbon fiber woven tape, and the like can be used. Moreover, as a metal tape, a stainless steel tape etc. can be used, for example. The circumferential reinforcing layer 13 may be wound around the flexible tube 1 from at least one direction.

  An outer waterproof layer 15 is provided around the outer periphery of the heat insulating layer 9b. The outer waterproof layer 15 can be deformed following the flexibility of the corrugated tube 3 while preventing water from entering from the outside. That is, when the flexible tube 1 is floated on the sea and LNG is transported, seawater or the like does not enter the flexible tube 1. The outer waterproof layer 15 is made of, for example, resin, and is preferably made of polyethylene. As described above, due to the heat insulating layers 9a and 9b, the influence of the temperature of LNG, which is a very low temperature, hardly affects the outer waterproof layer 15. For this reason, the external waterproof layer 15 does not become brittle when the temperature becomes low, and cannot follow the flexibility of the corrugated tube 3.

  FIG. 3 is a diagram illustrating a usage state of the flexible tube 1. An offshore floating facility 20 is provided on the sea. The offshore floating facility 20 is a storage base that is provided especially on the open sea and liquefies and stores natural gas calculated from the seabed gas field. The LNG stored in the offshore floating facility 20 is periodically transported to the tanker 27.

  A supply unit 21 is provided on the offshore floating facility 20. The supply unit 21 is a part that sends out LNG stored in the offshore floating facility 20. On the other hand, the tanker 27 is provided with a receiving unit 25. The receiving unit 25 is a part that receives the LNG sent out from the supplying unit 21.

  The flexible tube 1 is wound and stored around a drum 29 or the like, and is sent out from the drum 29 to the sea when in use. At sea, the end of the flexible tube 1 is guided to the tanker 27 by a small boat or the like not shown. After the flexible tube 1 is sufficiently sent to the sea, both ends of the flexible tube 1 are connected to the supply unit 21 and the receiving unit 25, respectively. While the flexible tube 1 floats on the sea, the LNG sent out from the supply unit 21 is transported to the receiving unit 25, and the LNG is loaded from the offshore floating facility 20 into the tanker 27. At this time, since the flexible tube 1 has flexibility, it can follow relative positional fluctuations caused by waves between the offshore floating body facility 20 and the tanker 27, and is stored on the offshore floating body facility 20. Never take a place.

  As described above, according to the flexible tube 1 according to the first embodiment, the axial reinforcing layer 7 is provided on the outer peripheral portion of the corrugated tube 3 via the floor layer 5, and therefore flows inside. It is possible to suppress the corrugated tube 3 from being deformed in the axial direction of the flexible tube 1 by the pressure of the fluid. Further, since the fluid in the corrugated tube 3 and the outside of the flexible tube 1 are thermally insulated by the heat insulating layers 9a and 9b, the fluid is not affected by the external temperature. 15 is not affected.

  Further, the intermediate waterproof layer 11 can prevent the fluid leaked inside from flowing to the external waterproof layer 15, so that the external waterproof layer 15 can be prevented from being damaged due to embrittlement.

  In addition, since the circumferential reinforcing layer 13 is provided on the outer peripheral portion of the intermediate waterproof layer 11, the intermediate waterproof layer 11 is prevented from being damaged by the pressure of the fluid or the pressure when the fluid vaporizes when the fluid leaks. Can do. For this reason, while being able to maintain the waterproofing effect of the intermediate | middle waterproof layer 11, the ejection from the flexible tube 1 of a fluid, etc. can be prevented.

  Moreover, since the heat insulation layers 9a and 9b contain airgel in the nonwoven fabric, a high heat insulation effect and a high water stop effect can be obtained.

  Next, the flexible tube 30 according to the second embodiment will be described. Note that in the following embodiments, the same components as those in FIG. 1 are assigned the same reference numerals, and redundant description is avoided. FIG. 4 is a perspective view showing a configuration of the flexible tube 30 according to the second embodiment, and FIG. 5 is a partial cross-sectional view of the flexible tube 30.

  The flexible tube 30 has substantially the same configuration as the flexible tube 1, but further includes heat diffusion layers 31a and 31b. The thermal diffusion layer 3 a is provided between the heat insulating layer 9 a and the intermediate waterproof layer 13. The thermal diffusion layer 31 b is provided between the heat insulating layer 9 b and the external waterproof layer 17.

  The heat diffusion layers 31 a and 31 b are layers for diffusing (heat transfer) heat in the circumferential direction or the length direction of the flexible tube 1. Therefore, the thermal diffusion layers 31a and 31b are made of a metal tape or the like having excellent thermal conductivity.

  FIG. 6A is a diagram showing the effect of the thermal diffusion layer 31a. In FIG. 6A, the outer layer of the intermediate waterproof layer 11 is not shown. As shown in FIG. 6 (a), when a leaking portion 33 occurs in a part of the corrugated tube 3 and the fluid 35 flowing inside the corrugated tube 3 flows out of the corrugated tube 3, the fluid 35 is reinforced with the seating layer 5 and the axial reinforcement. The temperature is transmitted in the direction of arrow A while penetrating the layer 7, the heat insulating layer 9a, and the like. That is, a local low temperature part is formed immediately above the leakage part 33. When the intermediate waterproof layer 11 is made of resin, a large temperature distribution is generated in the intermediate waterproof layer 11, and therefore the intermediate waterproof layer 11 is damaged by embrittlement.

  The heat diffusion layer 31a diffuses heat (heat conduction) in the heat diffusion layer 31a before the fluid penetration and heat conduction reach the intermediate waterproof layer 11 immediately above the leakage portion 33 in the direction of arrow A (arrow arrow). B direction). That is, the formation of a temperature distribution generated in the intermediate waterproof layer 11 is suppressed by suppressing the formation of a local low temperature portion of the intermediate waterproof layer 11 and diffusing heat by heat conduction in the length direction and the circumferential direction of the flexible tube 30. Can be suppressed.

  FIG. 6B is a diagram showing the effect of the thermal diffusion layer 31b. In addition, in FIG.6 (b), illustration of the inner layer of the heat insulation layer 9b is abbreviate | omitted. As shown in FIG. 6 (b), the flexible tube 30 is usually used floating on the sea surface 37. In this case, a part of the flexible tube 30 is exposed from the sea surface 37 and exposed to the outside air. On the other hand, a part of the flexible tube 30 sinks below the sea surface 37.

  If the outside air temperature and the seawater temperature are substantially the same, temperature distribution will not occur in the external waterproof layer 15 due to the external environment when the flexible tube 30 is used. However, when used in a very cold region, for example, the outside air may be below freezing and seawater may be higher than the outside air. In this case, in the outer waterproof layer 15 of the flexible tube 30, a temperature distribution occurs between a portion exposed to the outside air and a portion sinking below the sea surface 37.

  On the contrary, when the flexible tube 30 is used in a tropical region or the like, the portion of the external waterproof layer 15 that is exposed to the outside air becomes hot under hot weather. Also in this case, in the outer waterproof layer 15 of the flexible tube 30, a temperature distribution is generated between a portion exposed to the outside air and a portion sinking below the sea surface 37.

  The outer waterproof layer 15 is made of resin as described above, and the durability of the outer waterproof layer 15 is significantly reduced due to the generation of thermal stress accompanying the temperature distribution. The thermal diffusion layer 31b is provided inside the outer waterproof layer 15, and diffuses (conducts) heat from the outer waterproof layer 15 in the circumferential direction (arrow C direction) and the length direction of the flexible tube 30. For this reason, the temperature distribution of the outer waterproof layer 15 can be relaxed.

  According to the flexible tube 30 according to the second embodiment, the same effect as that of the flexible tube 1 can be obtained. Further, the thermal diffusion layers 31a and 31b can relax the temperature distribution generated in the intermediate waterproof layer 11, the outer waterproof layer 15, and the like, thereby suppressing the generation of thermal stress due to the temperature distribution. For this reason, the intermediate waterproof layer 11 and the external waterproof layer 15 due to thermal stress can be prevented from being deteriorated or damaged, and the highly flexible flexible tube 30 can be obtained.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, as the heat insulating material constituting the heat insulating layers 9a and 9b, a heat insulating material 41 laminated with a stainless steel tape (SUS tape) 43 can be used. FIG. 7 is a view showing a heat insulating material 41 having a SUS tape 43 laminated on one surface. In this case, the SUS tape 43 functions as the thermal diffusion layers 31a and 31b and also functions as a circumferential reinforcing material. When the heat insulating material 41 is used, the heat insulating material 41 on which the SUS tape 43 is laminated in advance may be wound around a predetermined portion.

  The flexible tubes 1 and 30 are not limited to LNG transportation. In addition, it can be used for transportation of various fluids.

The perspective view which shows the structure of the flexible tube 1. FIG. FIG. 3 is a partial cross-sectional view showing the configuration of the flexible tube 1. The figure which shows the use condition of the flexible tube. The perspective view which shows the structure of the flexible tube 30. FIG. FIG. 3 is a partial cross-sectional view showing a configuration of a flexible tube 30. It is a figure which shows the thermal diffusion in the thermal diffusion layers 31a and 31b, (a) is a figure which shows the function of the thermal diffusion layer 31a, (b) is a figure which shows the function of the thermal diffusion layer 31b. The perspective view which shows the heat insulating material 41. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 30 ......... Flexible tube 3 ......... Corrugated tube 5 ......... Seat floor layer 7 ...... Axial reinforcement layer 9a, 9b ...... Heat insulation layer 11 ... Intermediate waterproof layer 13 ......... Circumferential reinforcing layer 15 ...... Outer waterproof layer 20 ...... Offshore floating body facility 21 ...... Supply unit 25 ...... Receiver unit 27 ...... Tanker 29 …… Drums 31 a, 31 b …… Thermal diffusion layer 33 ... Leakage part 35 .... Fluid 37 ... ... Sea surface 41 ... ... Insulation material 43 ... ... SUS tape

Claims (6)

A corrugated metal inner tube having at least flexibility;
A first reinforcing layer provided on the outer periphery of the corrugated metal inner tube;
A first heat insulating layer provided on the outer periphery of the reinforcing layer;
An intermediate waterproof layer provided on the outer periphery of the first heat insulating layer;
A second reinforcing layer provided on the outer periphery of the intermediate waterproof layer;
A second heat insulating layer provided on the outer periphery of the second reinforcing layer;
An external waterproof layer provided on the outer periphery of the second heat insulating layer;
A flexible tube for transporting a cryogenic fluid characterized by comprising:   2. The thermal diffusion layer is further provided between at least one of the first heat insulation layer and the intermediate waterproof layer or between the second heat insulation layer and the external waterproof layer. The flexible tube for cryogenic fluid transportation as described.   3. The cryogenic fluid transportable device according to claim 1, wherein a metal tape is provided on at least one surface of the first heat insulation layer or the second heat insulation layer. 4. Flexible tube.   4. The flexible pipe for transporting a cryogenic fluid according to claim 1, wherein the first heat insulation layer and the second heat insulation layer are nonwoven fabric layers containing airgel. 5. . In the first reinforcing layer and the second reinforcing layer,
Polyester fiber woven tape, aramid fiber woven tape, arylate fiber woven tape, ultra high molecular weight polyethylene fiber woven tape, carbon fiber woven tape, or metal tape are used,
The first reinforcing layer is an alternating winding in which the tape is wound clockwise and counterclockwise on a flexible tube,
The flexible tube for transporting cryogenic fluid according to any one of claims 1 to 4, wherein the second reinforcing layer has the tape wound around the flexible tube from one direction. . A corrugated metal inner tube having at least flexibility;
A first reinforcing layer provided on the outer periphery of the corrugated metal inner tube;
A heat insulating layer provided on the outer periphery of the reinforcing layer;
A thermal diffusion layer provided on the outer periphery of the heat insulating layer;
An external waterproof layer provided on the outer periphery of the thermal diffusion layer;
A flexible tube for transporting a cryogenic fluid characterized by comprising:

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