Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L59/00—Thermal insulation in general
  • F16L59/14—Arrangements for the insulation of pipes or pipe systems
  • F16L59/141—Arrangements for the insulation of pipes or pipe systems in which the temperature of the medium is below that of the ambient temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/08—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall
  • F16L11/081—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more layers of a helically wound cord or wire
  • F16L11/082—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more layers of a helically wound cord or wire two layers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/11—Hoses, i.e. flexible pipes made of rubber or flexible plastics with corrugated wall
  • F16L11/112—Hoses, i.e. flexible pipes made of rubber or flexible plastics with corrugated wall having reinforcements embedded in the wall

Definitions

• the present invention relates to a flexible transfer hose for a cryogenic fluid.
• US patent application publication US 2012/0012221 describes a composite hose for transfer of cryogenic fluids.
• the composite hose can be used for example in a long floating or submerged liquefied natural gas (LNG) transfer line between two off-shore placed vessels.
• LNG liquefied natural gas
• the composite hose described in US 2012/0012221 comprises fabrics layers that are sandwiched between an inner wire and an outer wire. Both inner and outer wires are helically wound, whereby the outer wire is located between the inner wire pitches. It appears clearly that the inner surface of the composite hose is hence not flat but corrugated and presents many obstacles to the fluid, which may induce an appreciable pressure drop in the LNG being transferred though the hose.
• a liner consisting of self clamping or snap-on elongated inner strip or shell has been installed on the inner wire, whereby flanges of each strip or shell overlap the adjacent one so that a flat inner surface is offered to the composite hose.
• a flexible transfer hose for a cryogenic fluid comprising:
• an inner tube comprising a tube wall around a bore and arranged to contain a cryogenic fluid flowing through the bore in an axial direction, said tube wall having an inner surface facing inward to the bore and an outer surface facing away from the bore;
• a first mechanical support frame configured around the tube wall
• first mechanical support frame is arranged inside the external duct whereby the first mechanical support frame is moveable relative to the tube wall in axial direction.
• Fig. 1 schematically shows a longitudinal cross sectional view of a first group of embodiments of the cryogenic transfer hose proposed herein;
• Fig. 2 schematically shows a longitudinal cross sectional view of a second group of embodiments of the cryogenic transfer hose proposed herein;
• Fig. 2 schematically shows a longitudinal cross sectional view of a third group of embodiments of the cryogenic transfer hose proposed herein.
• the presently proposed transfer hose has an inner tube comprising a tube wall around a bore and arranged to contain a cryogenic fluid flowing through the bore in an axial direction.
• a first mechanical support frame is arranged inside a duct which is bonded to an outer surface of the inner tube wall, whereby the first
• mechanical support frame is moveable relative to the tube wall in the axial direction.
• the inner tube may form a lining having a continuous inner surface, which is helpful to reduce the pressure drop that the cryogenic fluid is exposed to as it flows through the bore.
• the mechanical support frame provides radial strength to the inner tube, guarding the inner tube against expansion as well as collapse. The latter is ensured because the duct in which the mechanical support frame is arranged is bonded to the inner tube wall and can therefore exert a radially outward pulling force on the tube wall. This configuration allows the tube wall to be formed out of a relatively deformable (flexible, low-stiffness) material with relatively low
• the inner tube may be in extruded form and/or formed out of a polymeric material.
• the cryogenic fluid flowing through the bore may be in immediate contact with the inner surface of the tube wall.
• the inner surface is relatively smooth in axial direction compared to a profile in the axial direction that the first mechanical support frame forms together with the outer surface around which it is configured. In other words, it is relatively smooth compared to the inside duct of a hose where the first mechanical support frame is disposed inside the flow duct. It is also smoother than the surface in the hose as proposed in
• the material of the inner tube wall may be any material of the inner tube wall.
• the permeability for the cryogenic fluid (e.g. LNG) of the material of the inner tube wall may be at least a factor of ten lower than that of the fabrics or other layers that may be provided external to the inner tube and ducts.
• the tube wall may consist of a composite polymeric material, preferably a single polymer composite material.
• the composite polymeric material has:
• the tensile Young's modulus may be determined according to DIN EN ISO 527 at ambient conditions, that is standard atmospheric
• the tensile strain at break may be determined according to DIN EN ISO 527 at ambient conditions.
• Suitable examples include single polymer composite materials, including polypropylene (PP) fibers in a PP matrix, or based thermoplastic polymers including
• PE polyethylene
• PA polyamide
• PET polyethylene terephthalate
• the first mechanical support frame may suitably be a wire.
• the first mechanical support frame may suitably comprise, preferably be formed out of metal.
• the first mechanical support frame may be provided in the form of a metal wire.
• the first mechanical support frame may be wound, preferably helically wound, around the tube wall of the inner tube. Alternatively, the first
• the mechanical support frame could be configured in the form of a plurality of individual rings around the inner tube, but this is expected to be more expensive to assemble than a (helically) wound wire or the like.
• the first mechanical support frame is slidingly arranged relative to the outer surface of the tube wall.
• the first mechanical support frame may be in direct contact with the outer surface of the tube wall, but there may also be an auxiliary layer configured concentrically between the tube wall and the first mechanical support frame.
• the auxiliary layer may form part of the duct, and may be bonded to the outer surface of the tube wall.
• the steel comprises, preferably essentially consists of, steel.
• the steel may consist of a stainless steel alloy, for instance a marine grade steel alloy.
• the steel is of a high-Nickel steel alloy.
• the alloy may contain at least 10% by weight Cr and 6% by weight Ni, and preferably less than 0.1% by weight of carbon.
• suitable example is a steel alloy of grade 316 as defined by SAE (Society of Automotive Engineers).
• any suitable duct that is adhered to or integrated with the inner tube Any means or method to integrate or adhere the duct to the outer surface of the tube wall or may suffice. Examples include co-extrusion, a weld joint, a groove-and-fin snap connection, adhesion by a layer of an adhesive, etc. including combinations thereof. Weld-bonded by means of a weld joint is
• resolidification may include chemical resolidification, by a chemical reaction, for instance under influence of a hardener.
• bore is not intended to be limited to bores having a circular cross section. While a circular cross section generally remains to be a preferred embodiment, as it maximizes the cross sectional area compared to the length of the circumference, non- circular cross sections may be employed if so desired. Particular an oval cross section may be selected, which has a relatively smaller open area for flow but may be beneficial in reducing the minimum bending radius of the flexible hose.
• the flexible transfer hose as described herein is particularly suited for transferring a cryogenic fluid.
• the cryogenic fluid may be pure or blended.
• cryogenic fluid as it flows through the hose may be below -30 °C, preferably below -100 °C, more preferably below -150 °C.
• Liquefied natural gas is an important example of a cryogenic fluid that can be transferred with the proposed hose, but other examples include liquefied nitrogen, liquefied oxygen, liquefied air, and liquefied petroleum gas (LPG) .
• LPG liquefied petroleum gas
• a pressure in the range of from 1.0 bar absolute to 1.5 bar absolute is typically about -162 °C.
• a main area of application is envisaged in transferring the cryogenic fluid between two off-shore vessels, for instance between a floating LNG plant and/or floating LNG storage facility and a bulk LNG carrier.
• Another example is transfer of LNG between a bulk LNG carrier or a floating storage unit and an LNG regasification facility at or near an LNG import site.
• the hose may be floating on water or be partially or fully
• the inner diameter of the bore may be selected of any suitable size, depending on the application, the required flexibility and the flow-rate and associated tolerance on pressure drop.
• any diameter in the range of from about 10 cm (4 inch) to about 50 cm (20 inch) may be technically and commercially attractive.
• Specific demand may exist for a 20-cm variant (8 inch) and for a 40-cm variant (16 inch) .
• any suitable end fitting may be provided on the proposed hose, allowing coupling of the hose to a supply source and/or a destination of the cryogenic fluid or to another cryogenic transfer hose.
• Fig. 1 in the drawing illustrates a group of
• the flexible hose comprises an inner tube 1 comprising a tube wall 2 around a bore 3.
• the inner tube 2 is an extruded tube. It is arranged to contain the cryogenic fluid flowing through the bore 3 in an axial direction A.
• the tube wall 2 has an inner surface 4 facing inward (towards the bore 3) and an outer surface 5 facing away from the bore 3.
• a first mechanical support frame 6 is wound around the tube wall 2 in sliding contact with the outer surface 5.
• the first mechanical support frame is suitably provided in the form of a metal wire helically evolving around the inner tube wall 2.
• An external duct 7 is bonded to the outer surface 5 of the tube wall 2, for instance weld-bonded by weld joints 8.
• the first mechanical support frame 6 is arranged inside the external duct 7.
• the mechanical support frame 6 is axially moveable relative to the tube wall 2.
• the mutual axial movability is achieved by allowing a clearance 9,10 for axial play of the first mechanical support frame 6 in the duct 7.
• the clearance 9,10 is illustrated in Fig. 1 between the first mechanical support frame 6 within the duct 7 and the side walls 11 of the duct 7.
• the inner tube 2 may be formed by extruding a polymer or a polymer composite.
• the weld- oints may be formed by welding, suitably by laser welding or induction welding. If induction welding is used, a thin piece of metallic mesh may be applied between the duct and the outer surface 5 of the tube wall 2 to facilitate electric conduction in the area of the anticipated weld- joint.
• each duct 7 consists of two side walls 11 and a cover that is integral to the side walls.
• the side walls 11 are bonded to the tube wall 2.
• the bonds, e.g. in the form of the weld joints 8, are in the pitch in between two consecutive windings of the first mechanical support frame .
• FIG. 2 where the two consecutive side walls 11, as seen in the axial direction one on either side of one winding of the mechanical support frame 6, each individually stand out from the outer surface 5 of the tube wall 2.
• a non-integral cover 15 is subsequently applied to close the duct 7 over the winding of the mechanical support frame 6 between the two consecutive side walls 11.
• Non- integral is intended to denote that the cover is non- integral to the side walls 11 at least before it is applied to close the duct 7. Nonetheless, the non- integral cover 15 should be bonded or otherwise attached to the side walls 11 in other to be able to transmit a radial suspending force from the first mechanical support frame 6 to the tube wall 2 to protect the tube wall 2 against collapse.
• Fig. 3 illustrates still another group of
• the duct is made out of a U-profile, wherein the consecutive side walls 11 are connected with a base
• the base 16 may be bonded to the outer surface 5 of the tube wall 2, and thus form an auxiliary layer between the first mechanical support frame 6 and the outer surface 5 of the tube wall 2.
• separate weld zones may be provided on both sides of the base 16 near or under the two consecutive side walls 11.
• a single weld zone 18 for the two consecutive side walls 11 may be provided on the base 16 between the two consecutive side walls 11 of each duct 7, as illustrated in Fig. 3.
• a non-integral cover 15 may subsequently be applied to close the duct 7 over the winding of the mechanical support frame 6 between the two consecutive side walls 11.
• the duct may be formed out of an "Omega ( ⁇ ) profile" consisting of a duct with flanges on the side walls that can be used to bond with the outer surface 5 of the tube wall 2.
• consecutive windings of the first mechanical support frame 6 are separated from each other as seen in the axial direction with at least one side wall 11 of the duct 7.
• the flexible hose may comprise one or more layers 12a, 12b of materials configured around the inner tube 1 and the external duct 7.
• a second mechanical support frame 14 (suitably provided in the form of a second metal wire, and/or formed out of the same material as the first mechanical support frame) is configured around the one or more layers 12a, 12b of materials.
• the one or more layers are configured around the one or more layers 12a, 12b of materials.
• the duct cover is also located between the first mechanical support frame 6 and the one or more layers 12a, 12b) and the second mechanical support frame
• the one or more layers 12a, 12b of materials may comprise fabrics .
• the flexible hose is thermally insulated from the ambient environment.
• the amount of thermal insulation depends on the circumstances of the case. For instance, when the hose is for transferring LNG and expected to be in contact with sea water, the amount thermal insulation could be selected to achieve that a temperature differential of at least 155 °C between the bore and the ambient environment can be maintained in steady state. With this temperature differential
• insulation may be included amongst the one or more layers
• a suitable thermal insulation material is capable of bearing compressive mechanical load.
• a micro porous material suitable for this purpose is commercially available from Microtherm N.V., under the trade name Izoflex (TM) (also known under the name
• Microtherm (TM) Floppy Panel) It is available in flexible quilted panels.
• a water-tight jacket may be provided around the flexible hose, or possibly around the optional layer (s) of thermal insulation, to avoid thermal leaks caused by water infiltration.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rigid Pipes And Flexible Pipes (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (1)

Cited By (3)

Citations (5)

• 2013
  • 2013-06-27 WO PCT/EP2013/063467 patent/WO2014001429A1/fr not_active Ceased

Patent Citations (5)

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