EP3638939A1

EP3638939A1 - Coupling for cryogenic liquefied media

Info

Publication number: EP3638939A1
Application number: EP18722521.4A
Authority: EP
Inventors: Émilien Frère
Original assignee: Messer France SAS
Current assignee: Messer France SAS
Priority date: 2017-06-13
Filing date: 2018-05-04
Publication date: 2020-04-22
Also published as: WO2018228749A1; CN110537049A; DE102017005588A1; US20200182389A1

Abstract

The invention relates to a coupling for cryogenic liquefied media, said coupling comprising a coupling socket (10) and a coupling connector (30), which can be connected thereto, each being equipped with a non-return valve (15, 40). According to the invention, the coupling socket (10) comprises a front section (11), having means for connecting to the coupling connector (30), and a rear section (12), having the non-return valve (15). According to the invention, the front section (11) is connected to the rear section (12) by means of screws (33) having predetermined breaking points, which break upon exceeding a specified tensile stress. According to the invention, the sections (11, 12) separate from each other and the non-return valves (15, 40) automatically move to the closed position.

Description

Clutch for cryogenic liquefied media

The invention relates to a coupling for cryogenic liquefied media for connecting fluid-carrying lines with a coupling socket and a coupling plug, each of which is equipped with a non-return valve which seals in the decoupled state arranged in the respective coupling part flow-through against the ingress of ambient air, but these automatically when connecting opens, wherein the coupling socket comprises a front portion having means for connecting to the coupling plug and a rear portion having the check valve, and the front portion is fixed, but releasably connected to the rear portion with the application of a predetermined tension.

Couplings for connecting lines for cryogenic liquefied media are known. Such couplings are used in particular when stationary tank installations are filled with cryogenic media from a tanker.

No. 4,335,747 A1 describes a coupling with a coupling plug and a coupling socket, each of which is equipped with a ball valve arranged at the end and is connected to one another by means of bolts. The coupling process takes place here in the two steps of sealing outwards and connecting the flow devices. However, separate shut-off valves for the flow lines are required. In addition, the ball valves are not vacuum-insulated and the cryogenic liquid released during decoupling leads to the freezing of the ball valves. According to a similar principle as the subject of US 4,335,747 A1, the clutches described in DE 41 04 71 1 A1 and DE 42 19 912 A1 are constructed.

The subject of DE 195 1 6 029 C1 is a coupling for cryogenic liquefied media, are connected to each other in the vacuum-insulated line ends via a coupling plug and a coupling socket. The line ends have on their front sides axially displaceable sealing means, which are displaced in each case by a spring in a position with separate coupling, in which they seal the respective line end against the ingress of ambient air. When inserting the coupling plug into the coupling socket, the sealing means are automatically moved against the force of the spring in their respective opening position. As a result, a flow path through the two coupling parts is opened, which is sealed to the outside and is isolated. To create a permanent connection, the coupling parts are screwed by means of a union nut. In this article, icing of the line ends in the decoupled state is avoided as well as icing of the coupling during operation.

The subject matter of US 2006/278839 A1 comprises a coupling for fluid media with a coupling plug and a coupling socket. The coupling socket is in turn separated into two parts, which are interconnected by means of a clamping ring. The clamping ring has one or more predetermined breaking points at which the coupling socket is separated into two parts in the application. Simultaneously with the breakage of the coupling socket, the flow connection in the coupling plug is automatically interrupted.

The known couplings have the disadvantage that they are insufficiently secured in a strong tensile stress due to a fault, such as after completion of a refueling operation from a tanker, the clutch was accidentally not solved and the tanker is moved with the line connected. In these cases, it may cause breakage of the coupling and / or pipe or hose pieces of the line and thus to an uncontrolled leakage of cryogenic liquid. Although the lines can be secured by separate check valves, but these lead to an additional flow resistance, which reduces the flow of the cryogenic medium and increases the refueling duration.

From EP 2 781 818 A1 a coupling for cryogenic liquefied media for connecting fluid-carrying lines is known, with a coupling socket and a coupling plug, which are each equipped with a check valve. When connecting the coupling plug and coupling socket, the check valves bring each other in the open position, thus allowing a flow of the cryogenic medium. The coupling socket comprises a front portion to be connected to the coupling plug and a rear portion having the check valve, wherein the front portion is fixedly connected to the rear portion in the normal operating state by means of a permanent magnet. When a tensile force exceeding the holding force of the permanent magnet is exceeded, the the part of the coupling socket from each other, at the same time, the check valves automatically move to their closed position.

In the case of an emergency separation, the parts of the coupling are non-destructively separated from each other and can be easily reassembled afterwards. However, this system is only suitable for securing against comparatively weak tensile stresses; the handling of permanent magnets, which are designed for a high tensile stress and have a correspondingly strong holding force, proves to be very difficult especially in the re-attachment of the coupling parts. In addition, the magnetic field emanating from such a strong permanent magnet can disturb electronic systems in the environment.

The invention is therefore an object of the invention to provide a coupling for cryogenic media, which provides effective protection against tearing of the line and at the same time allows fast refueling and is easy to handle even in the design for high tensile stresses.

This object is achieved with a coupling with the features listed in claim 1. Advantageous developments of the invention are specified in the subclaims.

In contrast to prior art clutches, which are constructed of two coupling parts which can be firmly connected to one another, namely coupling socket and coupling plug, the coupling according to the invention has a three-part construction due to the separability of the front and rear sections of the coupling socket. Front and rear portions of the coupling socket are formed so that they separate from each other at a predetermined tension, whereupon the check valves in coupling socket and coupling plug move automatically into their respective closed position. This is inventively achieved in that the front and the rear portion of the coupling socket are firmly connected to each other with connecting means which have a predetermined breaking point. The connecting means connect the sections directly to one another and are selected such that the axial limit stress at which the predetermined breaking point breaks corresponds to the required maximum tensile stress. With the destruction of the connecting means separate the sections of Coupling box from each other and the check valves automatically go to their closed position. The uncontrolled outflow of cryogenic medium is effectively prevented in this way. The limit value of the tensile stress above which the front section separates from the rear section of the coupling socket as intended, is chosen according to the circumstances, in particular it must be lower than the tensile strength of the other components of the clutch or its associated line, but sufficiently large, to be able to withstand usual loads occurring during a normal refueling operation. The coupling according to the invention is particularly suitable for establishing a flow connection between two lines for liquid nitrogen or for another cryogenic liquefied gas, such as liquefied noble gas or natural gas. In particular, the coupling according to the invention is suitable as a quick coupling for refueling a equipped with a reservoir for a cryogenic liquefied medium refrigerated vehicle from a stationary storage tank, as they allow due to their simple and low flow resistance structure having a fast and straightforward connecting the lines and rapid refueling , yet provides high protection against uncontrolled leakage of cryogenic liquid.

Compared to the connection with a permanent magnet, the present invention has the advantage that even couplings with a high required tensile stress after the occurrence of an application, in which therefore the two sections of the coupling socket were solved because of exceeding the maximum tensile stress from each other, can be easily reassembled , In this case, only the remainders of the broken fasteners are to be removed and replaced by new connecting means.

A particularly preferred embodiment of the invention provides that the front portion is connected to the rear portion by means of screws, each having a predetermined breaking point. The screws are passed through holes in a flange of a portion of the coupling socket and screwed into a bore provided with an internal thread in a flange of the other portion of the coupling socket. As a preferred connection means between the two sections of the coupling socket so special screws are used, which have a predetermined breaking point, for example, a section with a reduced throughput. Knife on which the screws tear when applying a predetermined maximum axial tensile stress (limit load). Preferably, a plurality of screws, for example, three to eight screws, arranged at uniform angular intervals rotationally symmetrical in the two flanges. This embodiment has the particular advantage that when changing the requirements of the maximum tensile strength, the screws can be easily replaced and replaced by screws with a correspondingly different limit load.

The means for connecting the front section of the coupling socket to the coupling plug preferably include a bayonet closure or a screw closure, for example a cap nut, which is pulled onto a thread which is externally attached to the coupling plug or the front section. In this way, the front portion of the coupling socket and coupling plug remain firmly connected even after detachment of the rear portion.

The check valve of the coupling stretcher and the check valve of the coupling socket is preferably each equipped with an axially displaceable closing body, for example in the form of a plate or a ball, against the action of a restoring force of the flow-through opening of the respective coupling part sealing closed state in an opening the flow opening opening state is displaceable. In this case, the closing elements are designed such that they mutually shift when connecting the coupling parts in their respective opening state and thereby release a flow path between the lines which are interconnected by the coupling. When separating the coupling socket from the coupling plug, but also when separating the rear portion of the front portion of the coupling socket, the closing body on the other hand move automatically in their respective closed state and thus block the flow openings of the two coupling parts.

It is particularly useful if a sealing element is arranged at the front portion and / or the rear portion of the coupling socket, for example, a sealing ring, which ensures the gas-tightness of the coupling connection. The sealing ring is preferably formed temperature-resistant and made of PTFE, for example. An advantageous embodiment of the invention provides that the front portion of the coupling socket is equipped with a protective shield to protect the coupling socket against mechanical effects. This protective shield is, for example, a sleeve of metal or plastic arranged concentrically around the connecting elements of the coupling socket to the coupling plug, which separates the connecting elements, for example in the event that the parts of the coupling socket separate during an emergency release and the coupling socket drops to the floor, protected against damage or contamination, so that a rapid reconnection of coupling socket and coupling plug is possible.

A likewise advantageous embodiment of the invention is characterized in that the coupling socket is rotatably connected to a conduit for a cryogenic medium. With such a configuration, the invention takes into account the fact that, although lines for cryogenic media usually have a certain flexibility, but are difficult to turn in itself. Since a rotation of coupling socket and coupling plug is inevitable at least in a bayonet connection, the rotatable arrangement facilitates the handling of the coupling. For example, a fixed, for example, by welding, soldering or screwing, connected to a line for the cryogenic medium connection sleeve rotatably received in the housing of the coupling socket or the coupling plug.

Reference to the drawings, embodiments of the invention will be explained in more detail. In schematic views show, each in longitudinal section:

1: The separated components of a coupling socket of a coupling according to the invention,

Fig. 2: the assembled coupling socket and the coupling plug of

Coupling of FIG. 1 in the decoupled state,

3: The coupling of FIG. 1 and FIG. 2 in the closed state,

Fig. 4: The coupling of Fig. 1 to 3 after a tearing protection triggering

Event,

Fig. 5: A coupling according to the invention in another embodiment. The coupling shown in Fig. 1 to 4, designed as a quick coupling has a coupling socket 10 with a front portion 1 1 and a connectable with this rear portion 12. The equipped with a connecting piece 13 for connecting to a line, not shown here for a cryogenic medium, such as a liquid nitrogen line, equipped rear section 12 has a housing 14, in the interior of which a check valve 15 is arranged. The non-return valve 15 comprises a closure body 16 with a closing plate 17 which, when the coupling is open, frictionally seals a mouth 18 of the rear portion 12 under the action of a compression spring 21 in a gas-tight manner. The compression spring 21 extends radially on the outside of the closure body 1 6 between the closing plate 17 and a fixedly mounted in the interior of the housing 14 valve seat 19 which has a central bore 20 through which the closure body 1 6 is guided axially movable limited. At the opposite end of the connecting piece 13 of the housing 14 is for connection to the front portion 1 1, a flange 22nd

The front section 1 1 of the coupling socket 10 comprises a housing 24 which, at its end facing the rear section 12, has a flange 26 equipped with a PTFE sealing ring 25, which is welded, for example, to the housing 24. On the front part of the front portion 1 1 connecting elements for fixed, but releasable connection to a coupling connector 30 of the coupling are arranged; In the exemplary embodiment, these are slots 28, 29 of a bayonet closure. Another, arranged in the interior of the front portion 1 1 sealing ring 31 made of PTFE is used to ensure the gas-tightness after making a connection with the coupling connector 30. To connect the front portion 1 1 and rear portion 12 are in the flange 26 of the front portion 1 1 more with an internal thread equipped bores 32 are provided, which are aligned parallel to the longitudinal axis of the front portion 1 1 and preferably arranged at equal angular intervals. Correspondingly, threadless bores 31 are arranged in the flange 22 of the rear portion 12, whose diameters are slightly larger than those of the bores 32. To fasten the sections 1 1, 12 together, screws 33 are used in the exemplary embodiment, which are equipped in the region of the screw head 34 with a predetermined breaking point 35, which is, for example, a section with reduced strength, for example, a section with reduced material thickness. The screws 33 are passed through the holes 31 of the rear portion 12 and into the borehole. gene 32 of the front portion 1 1 screwed, whereby the two sections 1 1, 12 are fixed together. Incidentally, it is possible according to the invention in a simple manner, by replacing the screws 33 against screws higher or lower tensile strength, the connection between the sections 1 1, 12, the respective requirements with respect to the maximum tensile stress, which is to be exposed to the clutch during normal operation adapt ,

The coupling socket 10 composed of coupling socket 10 and coupling plug 30 is shown in FIG.

The coupling plug 30 shown in Fig. 2 comprises a housing 37, which is equipped for producing a fixed, but releasable plug-in rotary connection with the coupling socket 10 with buttons 38, 39, which correspond to the slots 28, 29. Just as in the rear portion 12 of the coupling socket 10, a check valve 40 is disposed in the interior of the coupling plug 30. The check valve 40 is similar to the check valve 15 of the coupling socket 10 constructed and includes a closure body 41 with a closing plate 42 which closes in the state shown in Fig. 2, an orifice 43 of the coupling plug 30 under the action of a compression spring 46 frictionally gas-tight. The compression spring 46 extends radially on the outside of the closure body 41 between closing plate 42 and a valve seat 44 fixedly mounted in the housing 37, which is equipped with a central bore 45, through which the closure body is guided axially limited movement. Furthermore, the housing 37 has a connecting piece 48 for connection to a line, not shown here, for a cryogenic medium.

In Fig. 3 the coupling is shown in the intended coupled state. In this state, the buttons 38, 39 of the bayonet lock engage with the corresponding slots 28, 29 and thus establish a firm connection between the coupling parts 10, 30. Incidentally, other types for mating and connecting the coupling socket and the coupling plug are also within the scope of the invention, such as, for example, the connection described in more detail in DE 195 1 6 029 C1 by means of a union nut. On their sides facing each other, the closing plates 17, 42 are equipped with plungers 50, 51, which are pressed against each other during mating of coupling socket 10 and coupling plug 30 and, as indicated in Fig. 3 by arrows, the closure body 1 6, 41 against the action of the spring force of the compression springs 21, 46 move into their respective opening state. As a result, at the same time in the region of the orifices 18, 43, a flow path between the interiors of coupling socket 10 and coupling plug 30 is opened. In order to create a flow connection in the direction of the connecting pieces 13, 48, respective flow openings 52, 53 are provided in the valve seats 19, 44 arranged in the interior of the coupling socket 10 and the coupling plug 30. In the region of the connection, the housing 37 of the coupling plug and the housing 24 of the front section 1 1 of the coupling socket 10 overlap in radial respect. A thermally insulated design of the housings 24, 37, for example by means of a vacuum ring chamber, effectively prevents icing of the coupling during the process Flowing through cryogenic medium.

In Fig. 4, a clutch is shown after the occurrence of a tearing protection triggering event. As "an anti-tearing event" here is understood an event in which an axial tensile force acts on the coupling, which is greater than the tensile strength of the predetermined breaking points 35 of the screws 33. In this case, the screws 33 are destroyed and the rear portion 12 of The coupling socket 10 separates from the front section 11, which is still fixedly connected to the coupling plug 30 by the bayonet closure, whereby the contact between the plungers 50, 51 of the closing bodies 16, 41 of the check valves 15, 40 is lost and the check valves 15, 40 automatically move to their closed position under the action of the compression springs 21, 46 (as indicated by arrows in Fig. 4) and the flow connection between the rear portion 12 of the coupling socket 10 and the coupling plug 30 is closed, thus causing such an event effectively prevents the coupling or part of the pipe from breaking and d as transported through the conduit cryogenic medium exits uncontrollably in the environment. The remains of the screws 33 are removed and the two sections 1 1, 12 of the coupling socket 10 can be reassembled with new screws 33 in a simple manner.

The embodiment of a clutch according to the invention shown in FIG. 5 differs from the clutch shown in FIGS. 1 to 4 only by additional elements on the coupling socket 56. The coupling plug 30 is identical and therefore provided with the same reference numeral. Incidentally, elements of the Coupling socket 56, which are the same effect to elements of the coupling socket 10, marked with the same reference numerals.

The coupling socket 56 is equipped with a protective shield 57 in the form of a sleeve which extends concentrically around the front portion 1 1 of the coupling socket 56 to protect the parts of the housing 24 of the front portion 1 1 in the case of mechanical effects, for example, in a fall of the Coupling socket 56 after an emergency opening of the coupling. The shield 57 prevents damage to the front portion 1 1, allowing the rapid restoration of the coupling connection after an emergency opening.

The coupling socket 10 is connected to a line, not shown here, for a cryogenic medium, for example by welding or by a threaded connection. Although customary conduits for cryogenic medium are usually flexible, they are difficult to twist in themselves. Since the bayonet connection shown here requires a quarter turn of the two coupling parts 10, 30 against each other, the coupling socket 56 - instead of a fixedly mounted on the housing or designed in one piece with this connecting piece 13 of the coupling of Figs. 1 to 4 - equipped with a connection piece 59 which is rotatably mounted on a housing 60 of the coupling socket 56. The preferred solid, such as by welding, with a line not shown here for a cryogenic medium connected connecting piece 59 has a circumferential projection 61, with which the connecting piece of the coupling plug 30 opposite end face 62 of the housing 60 is supported. In order to ensure a gas-tightness, a sealing ring 63 made of PTFE is provided in a groove of the end face 62. To prevent inadvertent detachment of the connection piece 59 from the housing 40, this is fixed in the axial direction by means of a coupling nut 64 engaging behind the projection 61, but in such a way that a rotational mobility of the connecting piece 59 relative to the housing 60 is maintained. LIST OF REFERENCES

10. coupling socket 38th button

1 1. Front section 39. Button

12. Rear section 40. Check valve

13. Connecting piece 41. closure body

14. Housing (rear section) 42. Locking plate

15. Check valve 43. Outlet

16. Closure body 44th valve seat

17. Lock plate 45. central bore

18. Outlet 46. Compression spring

19. Valve seat 47. -

20. Central bore 48. Connecting piece

21. Compression spring 49. -

22. Flange 50th plunger

23. - 51. tappet

24. Housing (front section) 52. Flow opening

25. Sealing ring 53. Flow-through opening

26. Flange 54. -

27. - 55. -

28th slot 56th coupling socket

29. Slot 57. Shield

30. Coupling plug 58. -

31. Bore 59. Connecting piece

32. Bore 60. Housing

33. screw 61. head Start

34. Screw head 62. End face

35. predetermined breaking point 63. sealing ring

36. Sealing ring 64. Union nut

37. housing (of the coupling plug)

Claims

claims

1 . Coupling for cryogenic liquefied media for connecting fluid-carrying lines, with a coupling socket (10, 56) and a coupling plug (30), which are each equipped with a check valve (15, 40) which in the uncoupled state in the respective coupling part (10, 30 ) arranged against ingress of ambient air seals, but this opens automatically when connecting, wherein the coupling socket (10, 56) having a means for connecting to the coupling plug (30) having front portion (1 1) and one Comprising check section (15) having rear portion (12), and the front portion (1 1) fixed, but releasably connected to the rear portion (12) is connected under application of a predetermined tensile stress,

characterized,

in that the front section (11) is connected to the rear section (12) by means of connecting means (33) which can be connected to the front section (11) and the rear section (12) and each have a predetermined breaking point (35).

2. Coupling according to claim 1, characterized in that the front portion (1 1) with the rear portion (12) by means of a predetermined breaking point (35) having screws (33) is connected, which through bores (31) in a flange (22, 26 ) of a portion (1 1, 12) of the coupling socket (10, 56) out and in a equipped with an internal thread holes in a flange of the other portion (12, 1 1) of the coupling socket (10, 56) are screwed.

3. Coupling according to claim 1 or 2, characterized in that the means for connecting the front portion (1 1) with the coupling plug (30) comprises a bayonet closure or a screw cap.

4. Coupling according to one of the preceding claims, characterized in that the check valve (35) of the coupling stretcher (30) and / or the check valve (15) of the coupling socket (10, 56) each with an axially displaceable closing body (1 6, 41) equipped against the action of a restoring force of a the flow-through opening (18, 43) of the respective coupling sealing part (10, 56, 30) sealing closing state in a flow-through opening (18, 43) releasing opening state is displaceable, wherein the

Closing body (1 6, 41) are designed such that they move when connecting coupling socket (10, 56) with the coupling plug (30) mutually in the respective opening state, releasing a flow path between the connected lines, but when disconnecting the coupling socket (10, 56) from the coupling plug (30) or when separating the rear portion (12) from the front portion (1 1) of the coupling socket automatically move into its closed state.

5. Coupling according to one of the preceding claims, characterized in that at the front portion (1 1) and / or the rear portion (12) of the coupling socket (10, 56) a sealing element, for example a sealing ring (36), for producing a gas-tight connection with the other section (12, 1 1) is arranged.

6. Coupling according to one of the preceding claims, characterized in that the front portion (1 1) of the coupling socket (56) is equipped with a protective shield (57) to protect the coupling socket against mechanical effects.

7. Coupling according to one of the preceding claims, characterized in that the coupling socket (56) is rotatably connected to a conduit for a cryogenic medium.