Cryogenic transfer hose
A flexible cryogenic transfer hose for connecting two cryogenic facilities, has a length of at least 20 m, and: an inner flexible hose with at least two segments, interconnected via at least two transverse inner connecting members, an outer hose surrounding the inner hose and including a watertight elastomeric or composite material, the outer hose having at least two segments mutually connected via two outer connecting members, the outer hose having a wall thickness of at least 2 cm, a bend radius of at least 2 m, and an internal diameter of at least 20 cm, the inner hose being kept at a distance from the outer hose via spacer elements bridging a distance between the outer wall of the inner hose and an inner wall of the outer hose, which distance is between 0.1 and 0.8 times the internal diameter d io of the inner hose.
1. A flexible cryogenic transfer hose ( 7 ) for connecting two cryogenic facilities, the hose in use extending in a marine environment and having a length of at least 20 m, comprising:
an inner hose ( 10 ) with at least two segments ( 12 , 13 ), the inner hose segments being interconnected via at least two inner connecting members ( 16 , 17 ; 30 ; 30 a , 30 b ; 70 ; 71 ; 72 , 73 ) extending in a transverse direction, the inner hose being flexible and comprising a flexible reinforced wall having an internal diameter of at least 10 cm; and
an outer hose ( 11 ) surrounding the inner hose and comprising a watertight elastomeric or composite material, the outer hose comprising at least two segments ( 20 , 21 ) which are mutually connected via two outer connecting members ( 24 , 25 ), and the outer hose having a wall thickness of at least 2 cm, a bend radius of at least 2 m, and an internal diameter of at least 20 cm,
wherein the inner hose is kept at a distance from the outer hose via a number of spacer elements ( 28 , 29 ) bridging a distance (Hi) between the outer wall of the inner hose and an inner wall of the outer hose, which distance is between 0.1 and 0.8 times the internal diameter (Di) of the inner hose ( 10 ),
wherein a longitudinal position of a pair of inner connecting members ( 16 , 17 ; 30 ; 30 a , 30 b ; 70 ; 71 ; 72 , 73 ) is situated at or near a longitudinal position of a pair of outer connecting members ( 24 , 25 ),
wherein the inner connecting members ( 16 , 17 ; 30 ; 30 a , 30 b ; 70 ; 71 ; 72 , 73 ) bridge the distance (Hi) between the inner and outer hose walls and comprise a flange section ( 16 , 17 , 72 , 73 ) of the inner hose wall, two transverse abutment surfaces ( 34 , 35 , 80 , 81 ) on the outer hose wall or fixed to the outer wall, the flange sections ( 16 , 17 , 72 , 73 ) being releasably engaged between the abutment surfaces ( 34 , 35 , 80 , 81 ) for preventing relative axial movement between the inner and outer segments ( 12 , 13 ; 20 , 21 ) at or near the longitudinal position of the pair of outer and inner connecting members in two axial directions upon expansion and upon contraction of the inner hose segments, and
wherein the flange sections ( 72 , 73 ) are releasable from the inner hose wall and/or wherein the abutment surfaces ( 34 , 35 , 80 , 81 ) are releasable from the outer hose wall such that upon removal of the flange sections ( 72 , 73 ) and/or the abutment surfaces ( 34 , 35 , 80 , 81 ) from the gap between the inner hose ( 10 ) and outer hose ( 11 ), and all wall parts of the inner hose ( 10 ) are at a distance from the wall of the outer hose ( 11 ).
2. The flexible cryogenic transfer hose ( 7 ) according to claim 1 , wherein the flanges of the inner hose are an integral part of the inner hose wall and are received between the legs of an axial fixation ring with a generally U-shaped cross section, the ring being releasably attached to the outer hose wall.
3. The flexible cryogenic transfer hose ( 7 ) according to claim 2 , wherein the fixation ring is seated in a ring-shaped recess on the inside of the outer hose wall.
4. The flexible cryogenic transfer hose ( 7 ) according to claim 2 , wherein the fixation ring is attached to the outside hose wall via an pair of annular notches on each side of the ring.
5. The flexible cryogenic transfer hose ( 7 ) according to claim 1 , wherein the inner hose is situated along a curved path relative to the outer hose.
6. The flexible cryogenic transfer hose ( 7 ) according to claim 1 , further comprising a metal bellow ( 49 ) being sealingly connected to both inner hose segments ( 12 , 13 ), the bellow in a sealing manner engaging with an outer circumferential surface of the inner hose on both sides of an end part ( 51 , 52 ) of the segments ( 12 , 13 ).
7. The flexible cryogenic transfer hose ( 7 ) according to claim 1 , wherein the inner hose is subjected to an axial pull force, prior to axially attaching the inner connecting members ( 16 , 17 ; 30 a , 30 b ; 72 , 73 ) to the outer hose ( 11 ), the inner hose ( 10 ) when not in use exerting an axially contractive force on the outer hose ( 11 ).
8. The flexible cryogenic transfer hose ( 7 ) according to claim 1 , wherein the outer hose ( 11 ) is stiffer than the inner hose ( 10 ) so as not be buckled by contraction of the inner hose after release of the axial pull force.
9. The flexible cryogenic transfer hose ( 7 ) according to claim 1 , wherein the length of the hose is at least 100 m.