Fittings for fluid distribution lines

Abstract

To provide a coupling for fluid distribution lines.SOLUTION: A coupling configuration (100) for connecting thermally insulated fluid distribution lines (102, 104) has a coupling (101) comprising a first coupling part (106) and a second coupling part (108), and connecting means (110) for connecting the two coupling parts (106, 108). A sheath (112) enclosing the coupling (101) is provided which abuts the thermal insulation of the fluid distribution lines (102, 104) in each case on both sides of the coupling (101). A cavity (114) formed by the sheath (112) is configured for thermal insulation between the coupling (101) and the exterior of the sheath (112).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a coupling for connecting fluid flow lines, in particular lines for cryogenic fluids. [Background technology]

[0002] The filling of tankers or ships with cryogenic media, e.g. liquefied gas, is often done with lines that are only partially insulated, if at all, and especially with non-insulated fittings. In the non-insulated areas, the temperature of the outer surfaces of the non-insulated lines and fittings drops so significantly that the lines and fittings freeze in these areas during filling. During filling with very cold liquids, e.g. liquid hydrogen at a temperature of -253°C or liquid helium at a temperature of -269°C, atmospheric oxygen can condense on the surfaces of the non-insulated lines and fittings, oxygen becoming liquid at -183°C. Liquid oxygen significantly increases the risk of fire, which is obviously highly undesirable.

[0003] This problem can be avoided, at least in the line itself, by using rigid or flexible insulated lines with insulation that maintains the temperature at the surface of the line or fittings always above the boiling point of oxygen. Proper insulation can be achieved, for example, by using vacuum insulated lines.

[0004] Some components of lines for cryogenic fluids can be insulated, if at all, only with great effort, in particular vacuum insulated. These include fittings for fixedly or releasably connecting the line sections to one another and fittings for connecting to the transport containers to be filled or emptied. In addition to the above fittings, the lines of the filling device for cryogenic media must generally be equipped with emergency disconnect fittings that disconnect the fitting parts and thus the line sections from one another, thereby preventing or limiting damage to the line or the filling device, if the axial tensile forces acting on the fitting parts or the lines connected thereto are exceeded or if the bending torques acting on the fitting parts or the lines connected thereto are exceeded. Emergency disconnect fittings and fittings that can be released without tools often have very complex and bulky triggering mechanisms, and it can be difficult to insulate them.

[0005] There are couplings for insulated fluid flow lines that provide their own thermal insulation, such as the "Johnston coupling", but the coupling halves in said known couplings must interlock over a relatively long distance, which has a negative effect in particular on the rapid disconnection of the line sections from each other, and therefore couplings of this kind are not suitable as emergency disconnect couplings.

[0006] Furthermore, the components involved in the filling, i.e. the line sections between the tank from which the cryogenic medium is removed and the tank into which it is filled, must often be electrically insulated from one another. The intention by this measure is, inter alia, to prevent the formation of sparks which could ignite flammable fluids or other flammable gases occurring at the joints due to potential differences at the connection of the filling line or at the disconnection after filling has taken place. In particular, in the manufacture of vacuum insulated lines, stainless steels or other electrically conductive metals are often used, so that in these particular cases corresponding measures for the electrical insulation of the line sections are required.

[0007] For electrical insulation of vacuum-insulated line sections, a ring of non-conductive material must be placed in each case between the inner and outer pipes of the line section, which must be permanently connected in an airtight manner to the respective pipe ends in order to maintain the vacuum. From a practical point of view, this type of electrical insulation of the line section is not possible. Summary of the Invention [Problem to be solved by the invention]

[0008] Taking this as a starting point, the present invention has the object of providing a coupling arrangement for a fluid flow line which overcomes one or more of the problems mentioned at the outset, or which at least improves upon known coupling arrangements. [Means for solving the problem]

[0009] To this end, the invention proposes according to a first aspect a coupling arrangement for connecting insulated fluid flow lines, comprising a coupling comprising a first coupling part and a second coupling part, and also a connecting means for coupling the two coupling parts to one another, where the connecting means can be configured for permanently or releasably connecting the coupling parts, for example by means of a screw or a tension ring or a clamping ring or a clamping tong. A connecting means for repeatedly releasably connecting lines without tools can in particular be used for temporary connections of the lines, for example only during filling with fluid. In this context, without tools means that the connecting means allows the coupling parts to be released from one another without special tools, for example by means of a locking lever or a locking clamp that is permanently connected to the coupling parts. As an alternative or in addition to a disconnection after activation of a locking device provided for this purpose, the connecting means can be configured to allow the coupling parts to be disconnected from one another if a predefined tensile force acting axially on the coupling or coupling arrangement or a bending torque acting on the coupling or coupling arrangement is exceeded.

[0010] In addition, the joint arrangement comprises a covering which surrounds the joint parts to be connected, in particular the non-insulated joint parts, and which is located on both sides of the joint in each case in contact with the insulation of the fluid flow line. The insulation of the fluid flow line can for example comprise a vacuum insulation with an inner pipe and an outer pipe, the intermediate space of which is evacuated or at least has an internal pressure substantially lower than the ambient pressure. The pipes can for example consist of steel, such as stainless steel, or other suitable metals or alloys, or plastics with sufficient mechanical and thermal strength. Other insulations include covering the actual fluid flow line with a suitable insulation material. The covering surrounding the joint parts can itself provide the insulation. For this purpose, the covering can consist of a thermal insulation material or a cavity located between the inner and outer surfaces of the covering can be filled with a thermal insulation material. Suitable filling materials can for example comprise hollow glass microballs, "glass bubbles", which only come into contact at a small surface and thus reduce the heat transport by thermal conduction. In addition, solid materials impede the heat transport by convection. A coating configured for thermal insulation can be configured, among other things, to ensure that the temperature on the exterior surface of the coating is above the condensation temperature of oxygen.

[0011] The joint may further comprise a sealing means for sealing the two joint parts when they are connected to each other. The sealing means may comprise a sealing ring or a sealing disc arranged between the joint parts, but it is also possible to provide the sealing means structurally as a one-piece joint part, for example by a specific surface design and / or surface machining.

[0012] In principle, it is desirable in various joints of a fluid flow line to prevent or at least limit as much as possible the escape of fluid during connection or disconnection. For this purpose, self-sealing joints, e.g. dry joints, i.e. joints, whose joint parts seal the line when the joint is disconnected, are commonly used. The joint parts are releasably and fluid-tightly connectable, e.g. latchable, to one another. A sealing arrangement, e.g. a spring-loaded valve having a closure element, is arranged in the through-flow channel of each joint part. When the joints are connected together, the closure element keeps the valve open. When the joint parts are disconnected, the valve seals the line connected to the respective joint part.

[0013] Thus, one or both fittings may each have a sealing arrangement that closes the line connected to the respective fitting in a fluid-tight manner when the fittings are disconnected, and that connects the respective fluid channels of the lines to each other in fluid communication when the fittings are connected. The sealing arrangement may include a valve, such as a ball valve or a cone valve, actuated by, for example, a spring-loaded valve or other closure element, that closes the fitting when the fittings are disconnected. Other embodiments of the sealing arrangement, such as a locking slide or a locking flap, are also contemplated.

[0014] The sheath may be of multi-part design, in which case, in the disconnected state of the coupling, one or more parts forming a first hood of the sheath may be connected to a fluid flow line connected to a first coupling part, and one or more parts forming a second hood of the sheath are then connected to a fluid flow line connected to a second coupling part, such that, when the coupling is disconnected, the hood is in each case connected to the coupling part.

[0015] In a multi-part design of the covering, the first and second hoods of the covering can be located against the insulation of the line or can be connected thereto in an airtight manner or in a manner that at least delays the evacuation or inflow of gas. The airtight connection can be made, for example, via corresponding sealing means between the hoods and the line or via an integrally bonded connection of the hoods and the insulation of the line. Depending on the design, the connection can at least delay the evacuation or inflow of gas. The first and second hoods of the covering can be connected to each other in a releasable and airtight manner or in a manner that at least delays the evacuation or inflow of gas, for example by sealing surfaces that are located against each other or interlock and between which a seal is arranged. The hoods themselves can in each case likewise be of multi-part design. At least one of the hoods of the covering can be arranged in an axially movable manner on the fluid flow line. The multi-part design of the covering or hood and the axial movability of the hoods can provide advantages for the installation.

[0016] The cladding may have an inlet or outlet opening for configuring the cavity to avoid condensation of the atmospheric air that has penetrated into the cavity. In a multi-component cladding, the inlet or outlet opening may be arranged in at least one of the hoods. The configuration of the cavity to avoid condensation of the atmospheric air that has penetrated into the cavity may include introducing a medium that does not condense and is preferably non-flammable at the temperatures occurring on the surfaces inside the cladding during operation through the inlet opening. An example of such a medium is a non-flammable gas that has a minimum condensation temperature occurring on the surfaces of the components surrounded by the cladding and / or on the inner surface of the cladding, in particular a condensation temperature that is lower than the melting point. An example of a suitable gas is helium, which has a very low condensation temperature. The one or more media introduced represent at least a portion of the atmosphere inside the cladding, thus reducing the amount of oxygen contained in the enclosed atmosphere and other gases that may condense inside the cladding. A low positive pressure of the one or more media inside the cladding may now be set, which positive pressure may be monitored by a pressure sensor connected inside the cladding. If the covering is not placed gas tight around the joint, new medium or gas can be introduced inside to restore the original positive pressure and prevent the ingress of oxygen-containing atmosphere if the threshold value is not reached. In addition, a pressure control valve, which preferably opens automatically, can be provided as a safety valve to prevent the internal pressure from rising above a certain value.

[0017] As an alternative to the introduction of one or more media, a pressure lower than atmospheric pressure can be generated through an outlet opening in the sheath, for example by a vacuum pump. For this purpose, the interior space of the sheath can be fluidly connected to a vacuum pump, for example at least temporarily, via a vent valve. The vacuum pump can be activated, for example if the sheath is not arranged completely gas-tight around the joint, in order to restore the original negative pressure inside the sheath as required and depending on the pressure by a pressure sensor fluidly connected inside the sheath. In addition, a vacuum valve that preferably opens automatically can be provided as a safety valve to prevent a too low internal pressure, which could lead to deformation of the sheath. In this alternative, the sheath is suitably equipped with structural reinforcements, for example web and / or rib structures, in order to provide the sheath with sufficient dimensional stability and strength. If the sheath is arranged around an emergency disconnect joint that disconnects the lines from each other if the permissible axial tensile force or bending torque is exceeded, a vent valve can be provided to compensate for the negative pressure in the sheath in order not to hinder or impede the emergency disconnection. The ventilation valve may be actuated via a force or displacement transducer connected to the lines, and preferably ventilates the evacuated cavity when a mechanical load smaller than that encountered by the emergency disconnect coupling disconnects the lines from one another. In the case of couplings that are periodically connected and disconnected, the ventilation valve may be connected to an actuator for disconnecting or connecting the coupling.

[0018] The embodiments of the coupling can have electrical insulation means between the coupling parts and the connecting means or between the coupling parts and the fluid flow line connected thereto. For this purpose, in a last variant, an electrical insulator can be arranged between at least one pipe end and the coupling part attached thereto, for example a ring or a disk made of an electrically insulating material. If the pipe end and the coupling part and the electrical insulator arranged therebetween are connected by a thread or other connecting element, said thread or connecting element must also be made of a non-conductive material or the electrical connection of the pipe end and the coupling part must be interrupted by a corresponding insulating sleeve, an insulating sheath around the connecting element, etc. In this variant, the covering can surround the electrical insulation means. For example, due to the electrical insulation between the two coupling parts by a non-conductive sealing ring between the coupling faces, the connecting means holding the coupling parts together must be of a non-conductive design as well.

[0019] In one or more of the embodiments and variations described above, the jacket may be constructed from a non-conductive material, such as, for example, a non-conductive plastic, such as polyethylene (PE) or glass fiber reinforced plastic (GFRP). If the jacket itself is constructed from a conductive material, an electrical insulator may be disposed between the jacket and its connection to the insulation of the fluid flow line. Alternatively or additionally, in the case of a multi-piece jacket, for example having two hoods, an electrical insulator may be disposed between the hoods.

[0020] In addition to the joints, other parts of the line system, whatever their design, which cannot be insulated in a simple manner, for example arrangements for the electrical insulation of line sections, can therefore likewise be surrounded by the covering of the joints, although, as explained above, it is also possible to cover said parts with a separate covering in each case.

[0021] The electrical insulation between the fittings or between at least one pipe end and the fitting attached to it and the electrically insulating properties of the hood or its fixation to the line ensure the necessary electrical decoupling of the two line parts.

[0022] The invention is explained in more detail below, by way of example, by means of embodiments with reference to the accompanying drawings, in which all figures are merely schematic and not to scale. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 shows a cross-sectional schematic of an exemplary joint arrangement according to the present invention in a decoupled state. [Diagram 2] FIG. 2 shows a cross-sectional schematic view of an exemplary joint configuration according to the present invention in a mated state.

[0024] In the figures, the same or similar elements are given the same or similar reference numbers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] FIG. 1 shows a schematic cross-sectional view of an exemplary joint arrangement 100 according to the invention in a disconnected state. The sheath 112 of the illustrated joint arrangement comprises a first hood 118 and a second hood 120. The hoods are made of a non-conductive material, such as PE or GFRP. The hoods do not lie directly against the surfaces of the joint parts 108, 110, but rather form a cavity 114 that can be evacuated to avoid condensation of atmospheric air that has entered the cavity, or that can be filled with a medium that does not condense and is preferably non-flammable at the temperature prevailing at the surface inside the sheath during operation. The first and second hoods 118, 120 are preferably located in an airtight manner against the insulation 126 of the fluid flow lines 102 and 104. In this embodiment, the insulation 126 is the outer pipe of a vacuum insulated fluid line. The first hood 118 comprises an inlet / outlet opening 122, which is an inlet or outlet opening, through which the coupling parts 106, 108 are connected, and when the hoods 118, 120 are connected to one another, the interior space 114 can be evacuated or filled with a non-condensable, preferably non-flammable, medium (not shown). The fluid flow line 104 is directly connected to the second coupling part 108. An electrical insulator 124, also arranged in the first hood 118, is provided between the fluid flow line 102 and the first coupling part. The electrical insulator can be an insulating disk or an insulating ring, which is arranged between the flange of the line 102 and the coupling part 106. The flange is connected in a liquid-tight manner to the electrical insulating means. In the illustrated embodiment, the coupling parts 106, 108 form an emergency disconnect coupling, which disconnects the coupling when a tensile force or bending torque on the lines 102, 104 is exceeded. Each fitting has a sealing arrangement 116 for sealing the disconnected line ends from each other. In the figure, the sealing arrangement 116 comprises a conical valve pressed against a valve seat by a mechanism not shown. Also, to achieve high fire resistance or fire protection of the valve, the valve can have a conical first sealing surface and the valve seat can have a conical second sealing surface, where the opening angle of the first sealing surface is smaller than the opening angle of the second sealing surface.The high contact pressures on the annular sealing surfaces due to the different cones result in a sealing of the valve arrangement, which functions reliably both in the case of hot filling, such as in the case of a fire, and also in the case of low temperatures of the valve arrangement depending on the cold medium. In particular, the tightness of the cold medium can be further improved by sealing elements which are elastic at low temperatures. A sealing element which is flexible at low temperatures (not shown) can be provided on at least one of the sealing surfaces of the valve or the corresponding valve seat. Examples of materials which are stable at low temperatures are polytetrafluoroethylene or fluoroelastomers.

[0026] Fig. 2 shows a schematic cross-sectional view of an exemplary coupling arrangement according to the invention in a coupled state. The first and second coupling parts 106, 108 are sealingly connected to a connection means 110. The sealing arrangement 116 of the two coupling parts 106, 108 is open and the lines 102, 104 are fluidly connected to each other. The connection means 110 is illustrated by a closure clamp which opens the connection of the coupling parts 106, 108 and disconnects the lines from each other at a tensile load above a certain value or a bending torque above a certain value. The first and second hoods 118, 120 are connected to each other and form a sheath 112 together with a cavity 114. The cavity 114, which is preferably hermetically closed or at least retards the evacuation or inflow of gases via an inlet / outlet opening 122, can be filled with a non-condensable, preferably non-flammable medium or evacuated (not shown). Sealing means (not shown) can be provided at the contact points between the first and second hoods. Electrical insulation of the lines 102 , 104 is ensured by an electrical insulator 124 . [Explanation of symbols]

[0027] 100 Fitting configurations 102 Line 104 Line 106 First joint 108 Second joint 110 Connection means 112 Covering 114 Cavity 116 Sealing configuration 118 First Food 120 Second Hood 122 Inlet / Exit opening 124 Electrical Insulators 126 Insulation

Claims

1. A fitting arrangement (100) for connecting insulated fluid flow lines (102, 104) comprising a fitting (101) including a first fitting part (106) and a second fitting part (108) and a connection means (110) for connecting the two fitting parts (106, 108), the connection means (110) releasably connecting the first fitting part and the second fitting part (106, 108) to each other, on both sides of the coupling (101), a covering (112) is provided surrounding the coupling (101), in each case located against the insulation of the fluid flow line, the cavity (114) formed by the covering (112) being configured to avoid condensation of atmospheric air that has penetrated into the cavity (114), the sheath (112) is of a multi-part design, in which, in the disconnected state of the fitting (101), one or more parts forming a first hood (118) of the sheath (112) are connected to the fluid flow line (102) connected to the first fitting (106) and one or more parts forming a second hood (120) of the sheath (112) are connected to the fluid flow line (104) connected to the second fitting (108); the first hood and the second hood (118, 120) of the covering (112) are located in contact with the insulation of the line (102, 104) or are connected thereto in an airtight manner or in a manner that at least delays the discharge or inflow of gas; and the first hood and the second hood (118, 120) of the covering (112) are releasably and airtightly connectable to each other or in a manner that at least delays the discharge or inflow of gas; the coating (112) has an inlet or outlet opening (122) for configuring the cavity (114) to avoid condensation of atmospheric air that has entered the cavity (114); To configure the cavity (114) to avoid condensation of atmospheric air that has entered the cavity (114), the cavity (114) may be evacuated through the outlet opening (122) by a vacuum pump that is at least temporarily fluidly connected to the cavity (114); The coupling is an emergency disconnect coupling which disconnects the lines from each other when an allowable axial tensile force or bending torque is exceeded, and a ventilation valve is provided to compensate for the negative pressure in the sheath so as not to prevent emergency disconnection, and the ventilation valve is actuated via a force or displacement transducer connected to the lines to ventilate the evacuated cavity in the event of a mechanical load occurring that is less than the force at which the emergency disconnect coupling disconnects the lines from each other.

2. 2. The coupling arrangement (100) of claim 1, characterized in that the first coupling part and / or the second coupling part (106, 108) have a sealing arrangement (116) that closes the line (102, 104) connected to the respective coupling part (106, 108) when the coupling (101) is disconnected.

3. 3. The coupling arrangement (100) of claim 1 or 2, characterized in that at least one of the hoods (118, 120) is provided with a safety valve that limits a pressure difference between the cavity (114) and an environment of the covering (112) to a threshold value.

4. The joint arrangement (100) according to any one of claims 1 to 3, characterized in that the connecting means (110) is configured to decouple the joint parts (106, 108) after a manual trigger or when a predetermined force or threshold acting axially on the joint (101) is exceeded and a bending torque acting on the joint (101) is exceeded.

5. The coupling arrangement (100) according to any one of claims 1 to 4, characterized in that electrical insulation means (124) are provided between the coupling parts (106, 108) and the connection means (110) or between the coupling part (106) and a fluid flow line (102) connected thereto.

6. The coupling arrangement (100) according to any one of claims 1 to 5, characterized in that the covering (112) is made of a non-conductive material and is connected to the insulation of the fluid flow line via an electrical insulator and / or an electrical insulator is disposed between the hoods (118, 120).

7. A joint arrangement (100) according to any one of the preceding claims, characterized in that the coating is configured for thermal insulation between the cavity and an exterior of the coating.

8. An insulated fluid flow line (102, 104) having a fitting arrangement (100) according to any one of claims 1 to 7.

9. A loading device for cryogenic fluids, comprising an insulated line (102, 104) according to claim 8 or a coupling arrangement (100) according to any one of claims 1 to 7.

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