EP3452750A1

EP3452750A1 - Transport container

Info

Publication number: EP3452750A1
Application number: EP17721530.8A
Authority: EP
Inventors: Heinz Posselt; Marko PARKKONEN; Hans-Einar FORSBERG; Anders Gronlund
Original assignee: Linde GmbH
Current assignee: Linde GmbH
Priority date: 2016-05-04
Filing date: 2017-05-04
Publication date: 2019-03-13
Anticipated expiration: 2037-05-04
Also published as: US10711945B2; WO2017190849A1; JP6949049B2; US20190145578A1; EP3452750B1; ES2910106T3; PL3452750T3; JP2019515219A

Abstract

The invention relates to a transport container (1) for helium (He), comprising an inner container (6) for receiving the helium (He), a coolant container (14) for receiving a cryogenic liquid (N₂), an outer container (2) in which the inner container (6) and the coolant container (14) are received, and a thermal shield (21) which can be actively cooled with the aid of the cryogenic liquid (N₂), the thermal shield (21) comprising a tubular base section (22) in which the inner container (6) is received, and a cover section (23, 24) that closes the base section (22) at the front and that is arranged between the inner container (6) and the coolant container (14), wherein an intermediate space (20) is provided between the inner container (6) and the coolant container (14) and said cover section (23, 24) of the thermal shield (21) is arranged in this space.

Description

description

transport container

The invention relates to a transport container for helium. Helium is extracted together with natural gas. For economic reasons, transport of large quantities of helium is meaningful only in liquid or supercritical form, that is, at a temperature of about 4.2 to 6 K and under a pressure of 1 to 6 bar. To transport the liquid or supercritical helium transport containers are used, which are to avoid too rapid pressure increase of helium, consuming thermal insulation. Such transport containers can be cooled, for example, with the aid of liquid nitrogen. Here, a cooled with the liquid nitrogen thermal shield is provided. The thermal shield shields an inner container of the transport container. In the inner container, the liquid or cryogenic helium is added. The holding time for the liquid or cryogenic helium is in such transport containers 35 to 40 days, that is, after this time, the pressure in the inner container on the

Maximum value of 6 bar increased. The supply of liquid nitrogen is sufficient for about 35 days. The thermal insulation of the transport container consists of a high vacuum multilayer insulation.

EP 1 673 745 B1 describes such a transport container for liquid helium. The transport container comprises an inner container in which the liquid helium is accommodated, a thermal shield which partially covers the inner container, a coolant container in which a cryogenic liquid for cooling the thermal shield is accommodated, and an outer container in which the

Inner container, the thermal shield and the coolant tank are arranged.

Against this background, the object of the present invention is to provide an improved transport container available.

Accordingly, a transport container for helium is proposed. Of the

Transport container comprises an inner container for receiving the helium, a coolant container for receiving a cryogenic liquid, an outer container, in which the inner container and the coolant container are accommodated, and a thermal shield which can be actively cooled with the aid of the cryogenic liquid, wherein the thermal shield comprises a tubular base portion, in which the inner container is accommodated, and a front portion terminating the base portion

Cover portion which is disposed between the inner container and the coolant container, and wherein between the inner container and the coolant container, a gap is provided, in which the lid portion of the thermal shield is arranged. The inner container may also be referred to as a helium container or inner tank. The transport container may also be referred to as a helium transport container. The helium can be referred to as liquid or cryogenic helium. The helium is in particular also a cryogenic liquid. The transport container is particularly adapted to the helium in cryogenic or liquid

or to transport in supercritical form. In thermodynamics, the critical point is a thermodynamic state of a substance characterized by equalizing the densities of the liquid and gaseous phases. The differences between the two states of aggregation cease to exist at this point. In a phase diagram, the point represents the upper end of the vapor pressure curve. The helium is filled into the inner container in liquid or cryogenic form. In the inner container then form a liquid zone with liquid helium and a gas zone with gaseous helium. After filling into the inner container, the helium therefore has two phases with different states of aggregation, namely liquid and gaseous. That is, in the inner container there is a phase boundary between the liquid helium and the gaseous helium. After a certain time, that is, when the pressure in the inner container increases, the helium in the inner container becomes single-phase. The phase boundary then no longer exists and the helium is supercritical. The cryogenic liquid or cryogen is preferably liquid nitrogen. The cryogenic liquid may also be referred to as a coolant. The cryogenic liquid may alternatively be, for example, liquid hydrogen or liquid oxygen. By virtue of the fact that the thermal shield is actively coolable or actively cooled, it is to be understood that the cryogenic liquid at least partially flows through or flows around the thermal shield in order to cool it. Especially is the thermal shield only in an operating condition, that is, when the inner container is filled with helium, actively cooled. When the cryogenic liquid is exhausted, the thermal shield may also be uncooled. In active cooling of the thermal shield, the cryogenic liquid may boil and

evaporate. The thermal shield thus has a temperature which corresponds approximately or exactly to the boiling point of the cryogenic liquid. The boiling point of the cryogenic liquid is preferably higher than the boiling point of the liquid helium. The thermal shield is particularly within the

Outer container arranged.

Preferably, the inner container and in particular the insulation element on the outside has a temperature which corresponds approximately or exactly to the temperature of the helium stored in the inner container. The temperature of the helium is, depending on whether the helium is in liquid or supercritical form 4.2 to 6 K. Preferably, the lid portion of the thermal shield closes the

Base section frontally completely off. The base portion of the thermal shield may have a circular or approximately circular cross-section. The outer container, the inner container, the coolant container and the thermal shield can be constructed rotationally symmetrical to a common symmetry or central axis. The inner container and the outer container are preferably made of stainless steel. The inner container preferably has a tubular

Base section, which is closed on both sides with curved lid sections. The inner container is fluid-tight. The outer container preferably also has a tubular base portion, which is closed on both sides of the lid portions on the front side. The base portion of the inner container and / or the base portion of the outer container may have a circular or an approximately circular cross-section.

The fact that the thermal shield is provided, it is ensured that the inner container is surrounded only by surfaces having a boiling point of the cryogenic liquid (boiling point nitrogen at 1 .3 bara: 79.5 K) corresponding temperature. This results in between the thermal shield (79.5 K) and the inner container (temperature of helium at 1 bara to 6 bara: 4.2 K to 6 K) in

Compared to the environment of the outer container only a small temperature difference. As a result, the holding time for the liquid helium compared to known Transport containers are significantly extended. Heat from the surfaces of the inner container to the thermal shield is transmitted only by radiation and residual gas line. That is, the surface of the thermal shield does not contact the inner container. Characterized in that the cover portion of the thermal shield between the inner container and the coolant container is arranged, it is always ensured even with a decreasing liquid level of the cryogenic liquid in the coolant container, that the inner container also in the direction of the coolant container of surfaces having the boiling temperature of the liquid nitrogen , is surrounded. The transport container points

in particular a helium hold time of at least 45 days and the supply of cryogenic liquid is sufficient for at least 40 days.

According to one embodiment, the thermal shield is arranged in an evacuated intermediate space provided between the inner container and the outer container.

The fact that the gap is evacuated, the thermal insulation of the inner container can be improved. The inner container preferably comprises an additional insulation element with a multilayer insulation layer and a metallically bright copper layer facing the shield. The insulating layer preferably comprises a plurality of alternately arranged layers of perforated and embossed aluminum foil as a reflector and glass paper as a spacer between the aluminum foils. The insulation layer can be 10-ply. The layers of aluminum foil and glass paper are applied gap-free on the inner container, that is, pressed. The insulation layer is a so-called MLI (multilayer insulation) or can be referred to as MLI. The insulating element preferably also has a boiling point of helium at least approximately or exactly corresponding temperature. Between the thermal shield and the outer container, a further multilayer insulation layer, in particular also an MLI, can be arranged, which separates the space between the

thermal shield and the outer container fills and thus the outside of the thermal shield and the outer container contacted on the inside. Layers of aluminum foil and glass paper, glass fiber or glass lattice fabric of the insulating layer are in this case deviating from the above-described insulation element of the inner container preferably fluffy introduced into the intermediate space. Fluffy means, that the layers of aluminum foil and glass paper, glass fiber or glass mesh fabric are not pressed, so that can be smoothly evacuated by the embossing and perforation of the aluminum foil, the insulating layer and thus the gap. Also, an undesirable mechanical-thermal contact between the

Aluminum foil layers reduced. This contact could get through

Radiation exchange adjusting temperature gradient of aluminum foil layers disturb.

According to another embodiment, the thermal shield has two

Lid sections, which complete the base section on both sides of the front side.

The lid sections are preferably curved. In particular, the

Cover sections with respect to the base portion in each case arched outwards. According to a further embodiment, the thermal shield is supported neither on the inner container nor on the outer container.

The fact that the thermal shield is supported neither on the inner container nor on the outer container, a better thermal insulation can be achieved. In particular, by the heat input into the inner container through

Heat conduction can be reduced. Preferably, the thermal shield comprises a support ring, which is suspended on the outer container via support rods, in particular tension rods. The inner container is preferably also suspended from the support ring via further support rods, in particular likewise tie rods.

According to a further embodiment, the thermal shield is fluid-permeable.

That is, the thermal shield is liquid and gas permeable. For this purpose, the thermal shield, for example, breakthroughs, perforations or holes have. As a result, the space provided between the inner container and the outer container can be evacuated.

According to a further embodiment, the thermal shield is made of a

Made of aluminum material. In particular, the thermal shield is made of a high purity aluminum material. This results in particularly good heat transfer and

Heat reflection properties. According to a further embodiment, the thermal shield for actively cooling thereof has at least one cooling line in which the cryogenic liquid can be received.

Preferably, the cryogenic liquid does not circulate in the cooling line, but is in it. To cool the thermal shield, the cryogenic liquid in the cooling line boils, thereby ensuring optimum cooling of the thermal shield. The cooling line may be materially connected to the thermal shield or formed materialeinstückig with the thermal shield. According to a further embodiment, the coolant container is in fluid communication with the at least one cooling line, so that the cryogenic liquid from the

Coolant tank flows into the at least one cooling line when the cryogenic liquid in the at least one cooling line partially evaporated. So that even with a reduced level of the cryogenic liquid in the coolant container, the cryogenic liquid completely wets the cooling line, a corresponding overpressure of 200 to 300 mbar is maintained in the coolant tank according to the applied hydrostatic pressure.

In particular, gas bubbles form in the cryogenic liquid, which can be passed through an oblique arrangement of the cooling line to a highest point of the same.

According to a further embodiment, the at least one cooling line is provided on the base portion and / or on the lid portion of the thermal shield and / or the base portion is integrally connected to the lid portion.

In particular, such cooling lines or at least sections of the cooling lines are provided on both cover sections. Because of that

Cover portion is integrally connected to the base portion, the cooling of the lid portion can be carried out by heat conduction. For cohesive connections the connection partners are held together by atomic or molecular forces. Cohesive connections are non-detachable connections that can only be separated by destroying the connection means. According to a further embodiment, the at least one cooling line has a pitch relative to a horizontal.

That is, the cooling line is inclined with respect to the horizontal. The horizontal is arranged perpendicular to a direction of gravity. For example, the cooling pipe and, more particularly, oblique portions of the cooling pipe include a predetermined angle with the horizontal. In particular, the sections with the horizontal enclose an angle greater than 3 °. The angle can be 3 to 15 ° or even more. In particular, the angle can also be exactly 3 °. The cooling line may also have sections extending in the direction of gravity.

According to a further embodiment, the transport container further comprises a phase separator for separating a gaseous phase of the cryogenic liquid from a liquid phase of the cryogenic liquid, wherein the at least one cooling line is arranged so that it has a positive slope in the direction of the phase separator.

By a positive slope is meant that the cooling line increases in the direction of the phase separator. As a result, the gaseous phase collects in the form of gas bubbles in the phase separator. The phase separator preferably includes a float having a float coupled to a valve body. As soon as the liquid level of the liquid phase in the phase separator drops due to the introduction of the gas bubbles, the valve body is lifted off a valve seat and the gaseous phase of the cryogenic liquid is blown off. As a result, the liquid phase flows into the phase separator, whereby the float floats again and the valve body is pressed onto the valve seat.

In particular, the phase separator ensures that only evaporated, cryogenic nitrogen is released into the environment.

According to a further embodiment, the transport container further comprises a plurality, in particular six, cooling lines. The number of cooling lines is arbitrary.

According to a further embodiment, the cover portion of the thermal shield completely shields the coolant container from the inner container.

This is to be understood that in a viewing direction of the inner container in the direction of the coolant tank, the coolant tank completely from the

Cover portion of the thermal shield is covered.

According to a further embodiment, the coolant container is arranged in an axial direction of the inner container next to the inner container.

Preferably, between the inner container and the coolant container a

Intermediate space provided in which the lid portion of the thermal shield is arranged.

According to a further embodiment, the thermal shield encloses the

Inner container completely.

This ensures that the inner container is completely surrounded by surfaces having a boiling temperature of the cryogenic liquid corresponding temperature. Other possible implementations of the transport container also include not explicitly mentioned combinations of before or below regarding the

Embodiments described features or embodiments. The expert will also add individual aspects as improvements or additions to the respective basic shape of the transport container.

Further advantageous embodiments of the transport container are the subject of the dependent claims and the embodiments of the transport container described below. Furthermore, the transport container will be explained in more detail by means of preferred embodiments with reference to the attached figures. Fig. 1 shows a schematic sectional view of an embodiment of a

Transport container;

FIG. 2 shows a further schematic sectional view of the transport container according to FIG. 1; FIG.

FIG. 3 shows a further schematic sectional view of the transport container according to FIG. 1; FIG. Fig. 4 shows a schematic sectional view of an embodiment of a

Phase separator for the transport container of FIG. 1;

5 shows the detailed view V according to FIG. 4; FIG. 6 shows a schematic rear view of the phase separator according to FIG. 4; FIG. and

FIG. 7 shows a schematic partial sectional view of the phase separator according to FIG. 4.

In the figures, the same or functionally identical elements are the same

Unless otherwise indicated.

Fig. 1 shows a highly simplified schematic sectional view of a

Embodiment of a transport container 1 for liquid helium He. FIGS. 2 and 3 show further schematic sectional views of the transport container 1. Reference will be made to FIGS. 1 to 3 at the same time.

The transport container 1 can also be referred to as a helium transport container. The transport container 1 can also be used for other cryogenic liquids. Examples of cryogenic liquids, or cryogens for short, are the aforementioned liquid helium He (boiling point at 1 bara: 4.222 K = -268.928 ° C.), liquid hydrogen H ₂ (boiling point at 1 bar: 20.268 K = -252.882 ° C.), liquid nitrogen N ₂ (boiling point at 1 bara: 77.35 K = -195.80 ° C) or liquid oxygen O2 (boiling point at 1 bara: 90.18 K = -182.97 ° C). The transport container 1 comprises an outer container 2. The outer container 2 is made of stainless steel, for example. The outer container 2 may have a length of for example 10 m. The outer container 2 comprises a tubular or cylindrical base portion 3 which is closed on both sides in each case by means of a cover section 4, 5, in particular by means of a first cover section 4 and a second cover section 5. The base portion 3 may have a circular or approximately circular geometry in cross section. The lid sections 4, 5 are curved. The cover sections 4, 5 are arched in opposite directions, so that both cover sections 4, 5 are curved outwardly with respect to the base section 3. The outer container 2 is fluid-tight, in particular gas-tight. The outer container 2 has a symmetry or central axis Mi, to which the

Outer container 2 is constructed rotationally symmetrical.

The transport container 1 further comprises an inner container 6 for receiving the liquid helium He. The inner container 6 is also made of stainless steel, for example. In the inner container 6, as long as the helium He in the

Two-phase region is to be provided, a gas zone 7 with vaporized helium He and a liquid zone 8 with liquid helium He. The inner container 6 is fluid-tight, in particular gas-tight, and may be a blow-off valve for controlled

Include depressurization. The inner container 6, like the outer container 2 comprises a tubular or cylindrical base portion 9, the front side of both sides

Cover portions 10, 1 1, in particular a first lid portion 10 and a second lid portion 1 1, is closed. The base portion 9 can in

Cross section have a circular or approximately circular geometry.

The inner container 6 is, like the outer container 2, rotationally symmetrical to the central axis Mi formed. A between the inner container 6 and the

Outer container 2 provided gap 12 is evacuated. The inner container 6 may further comprise an insulating element, not shown in FIGS. 1 to 3. On the outside, the insulating element has a highly reflective copper layer, for example a copper foil or a copper-vapor-deposited aluminum foil, and a multilayer insulating layer arranged between the inner vessel 6 and the copper layer. The insulating layer comprises a plurality of alternately arranged layers of perforated and embossed aluminum foil as a reflector and glass paper as a spacer between the aluminum foils. The insulation layer can be 10-ply be. The layers of aluminum foil and glass paper are gap-free on the

Inner container 6 applied, that is, pressed. The insulation layer is a so-called MLI. The inner container 6 and also the insulating element have on the outside approximately to the boiling point of the helium He corresponding temperature.

The transport container 1 further comprises a cooling system 13 (FIGS. 2, 3) with a coolant container 14. A cryogenic liquid, such as liquid nitrogen N 2, is accommodated in the coolant container 14. The coolant reservoir 14 comprises a tubular or cylindrical base section 15, which can be constructed rotationally symmetrical to the central axis Mi. The base portion 15 may have a circular or approximately circular geometry in cross section. The base portion 15 is frontally closed by a cover portion 16, 17. The

Cover portions 16, 17 may be curved. In particular, the lid portions 16, 17 are curved in the same direction. The coolant reservoir 14 may also have a different structure.

In the coolant tank 14, a gas zone 18 with vaporized nitrogen N ₂ and a liquid zone 19 may be provided with liquid nitrogen N ₂ . In a

Axial direction A of the inner container 6 is the coolant tank 14 adjacent to the

Inner container 6 is arranged. Between the inner container 6, in particular the lid portion 1 1 of the inner container 6, and the coolant container 14,

in particular, the lid portion 16 of the coolant tank 14 is a

Gap 20 is provided, which may be part of the gap 12. That is, the gap 20 is also evacuated.

The transport container 1 further comprises a cooling plate 13 associated thermal shield 21. The thermal shield 21 is in the between the

Inner container 6 and the outer container 2 provided evacuated space 12 is arranged. The thermal shield 21 is actively cooled or actively cooled with the aid of liquid nitrogen N2. Active cooling in the present case is to be understood as meaning that the liquid nitrogen N 2 for passing the thermal shield 21 is passed through it or passed along it. The thermal shield 21 is hereby cooled to a temperature which corresponds approximately to the boiling point of the nitrogen N ₂ . The thermal shield 21 comprises a cylindrical or tubular base section 22, which is closed on both sides by a cover section 23, 24 which terminates this end face. Both the base portion 22 and the lid portions 23, 24 are actively cooled by means of the nitrogen N2. The base portion 22 may in

Cross section have a circular or approximately circular geometry. The thermal shield 21 is preferably also rotationally symmetrical to the

Middle axis Mi built. A first cover portion 23 of the thermal shield 21 is between the inner container 6, in particular the lid portion 1 1 of the

Inner container 6, and the coolant tank 14, in particular the lid portion 16 of the coolant tank 14, respectively. A second cover section 24 of the thermal shield 21 faces away from the coolant reservoir 14. The thermal shield 21 is self-supporting. That is, the thermal shield 21 is supported neither on the inner container 6 still on the outer container 2. For this purpose, a support ring may be provided on the thermal shield 21, which is suspended by means of support rods, in particular tension rods, on the outer container 2. Furthermore, the inner container 6 can be suspended on the support ring via further support rods, in particular tension rods. The heat input through the mechanical support rods is partially realized by the support ring. The support ring has pockets that allow the greatest possible thermal length of the support rods. Of the

Coolant tank 14 has bushings for the mechanical support rods.

Between the thermal shield 21 and the outer container 2, a further multi-layer insulation layer, in particular an MLI, can be arranged, which the

Intermediate space 12 completely fills and thus the thermal shield 21 on the outside and the outer container 2 contacted on the inside. Layers of aluminum foil and glass paper, glass fiber or glass mesh fabric of the insulating layer are fluffy in deviation from the above-described insulation element of the inner container 6 introduced into the gap 12. Fluffy means here that the layers off

Aluminum foil and glass paper, glass fiber or glass mesh fabric are not pressed, so that the insulation layer and thus the gap 12 can be evacuated trouble-free by the embossing and perforation of the aluminum foil. As a result, the thermal-mechanical contact between the reflector layers is minimized, the temperature gradient of the reflector layers is approximately in accordance with the pure

Radiation exchange, whereby the heat transfer is minimized. The thermal shield 21 is fluid-permeable. That is, a gap 25 between the inner container 6 and the thermal shield 21 is in fluid communication with the gap 12. In this way, the gaps 12, 25 can be evacuated simultaneously. In the thermal shield 21 holes, openings or the like may be provided to allow evacuation of the spaces 12, 25. The thermal shield 21 is preferably of a high purity

Made of aluminum material. The thermal shield 21 is arranged circumferentially spaced from the copper layer of the insulating element of the inner container 6 and does not touch them. The incidence of heat is mainly due to radiation and is thereby reduced to the physically possible minimum. A gap width of a gap provided between the copper layer and the thermal shield 21 may be 10 mm. As a result, heat can be transmitted from the inner container 6 to the thermal shield 21 only by radiation and residual gas line.

The first lid portion 23 of the thermal shield 21 shields the

Coolant tank 14 completely against the inner container 6 from. That is, as seen from the inner container 6 to the coolant tank 14 is the

Coolant tank 14 is completely covered by the first lid portion 23 of the thermal shield 21. In particular, the thermal shield 21 encloses the

Inner container 6 completely. That is, the inner container 6 is completely disposed within the thermal shield 21, the thermal shield 21, as previously mentioned, is not fluid-tight. As FIGS. 2 and 3 further show, the thermal shield 21 for actively cooling it comprises at least one cooling line 26. Preferably, a plurality of such cooling lines 26, for example six such cooling lines 26, are provided. The cooling line 26 may comprise two vertical sections 27, 28 extending in the direction of gravity g and two inclined sections 29, 30. The vertical portions 27, 28 may be provided on the lid portions 23, 24 of the thermal shield 21.

The cooling line 26 is in fluid communication with the coolant reservoir 14 via a connecting line 31, so that the liquid nitrogen N _{2 is} forced from the coolant reservoir 14 into the cooling line 26. The connecting line 31 opens into a distributor 32, from which the section 27 and the section 30 branch off. The section 29 and the section 28 meet at a collector 33, from which a connecting line 34 leads to a phase separator 35 arranged outside the outer container 2. The phase separator 35 is configured to separate gaseous nitrogen N2 from liquid nitrogen N2. The gaseous nitrogen N2 can be blown out of the cooling system 13 via the phase separator 35.

The cooling pipe 26 or the cooling pipes 26 are provided both on the base portion 22 and on the lid portions 23, 24 of the thermal shield 21.

Alternatively, the lid portions 23 and 24 are material fit with the

Base section 22 connected. For example, the lid portions 23, 24 are welded to the base portion 22. When that the lid portions 23, 24th

material-locking, that is, are materially connected to the base portion 22, the cooling of the lid portions 23, 24 carried by heat conduction. The cooling line 26 and in particular the oblique sections 29, 30 of the cooling line 26 have a pitch relative to a horizontal H, which is arranged perpendicular to the direction of gravity g. In particular, the sections 29, 30 with the horizontal H an angle α of greater than 3 °. The angle α can be 3 to 15 ° or even more. In particular, the angle α can also be exactly 3 °. In particular, the sections 29, 30 in the direction of the phase separator 35 on a positive slope.

An embodiment of the phase separator 35 is shown in Figs. 4-7. The phase separator 35 comprises a housing 36 with a tubular base section 37, which is closed on both sides on the front side with cover sections 38, 39 on the front side. Housed in the housing 36 is an inner housing 40 with a tubular base portion 41 which is closed on both sides by cover portions 42, 43 the front side. Between the housing 36 and the inner housing 40 is an evacuated

Isolation space 44 is provided. The insulation space 44 may be provided, for example, with an MLI or filled with perlite or glass microspheres. A partially likewise vacuum-insulated connecting line 45 is in fluid communication with the connecting line 34. The phase separator 35 further comprises a blow-off line 46, via which gaseous nitrogen N2 is discharged. The connection line 45 is in fluid communication with an interior 47 provided in the inner housing 40. The Connecting line 45 is rotated with respect to the blow-off 46 by an angle ß. The angle ß can be 45 to 90 °.

In the interior 47, a float 48 is provided. The float 48 comprises a floating body 49 provided with a gas-tight metallic sheath, the interior of which is filled with a plastic foam. The floating body 49 is fixedly connected to a counterweight 51 via an axle 50. On the axis 50, a valve body 52 is fixed, which is arranged linearly displaceable in a valve seat 53. The axis 50 is rotatably supported in the inner housing 40 on a rotation axis 54. That is, with a decreasing liquid level of the liquid nitrogen N2 in the interior 47 of the float 49 decreases, whereby the axis 50 rotates about the axis of rotation 54, which in turn the valve body 52 is lifted from the valve seat 53 to the gaseous nitrogen N2 over to blow off the blow-off line 46. The phase separator 35 ensures that only evaporated, cryogenic nitrogen N2 is released into the environment. The phase separator 35 is in particular a cryogenic valve controlled by the float 48. The

A special feature of the phase separator 35 is the counterweight 51 of the horizontally mounted floating body 49, which prevents inadvertent lifting of the valve body 52 of the valve seat 53 during accelerations.

The phase separator 35 further comprises a valve 55 for generating a vacuum in the insulation space 44. In the inner housing 40, a baffle plate 56 may be arranged, which is intended to reduce a surge of the liquid nitrogen N2. Furthermore, as shown in FIGS. 2 and 3, on the coolant tank 14 a

Abblasventil 57 arranged to hold by blowing off the gaseous nitrogen N2 the set pressure in the coolant tank 14.

The operation of the transport container 1 will be explained below. Before filling the inner container 6 with the liquid helium He, the thermal shield 21 is first of all at least approximately or completely up to the boiling point (1.3 bara, 79.5 K) of the liquid nitrogen with the aid of cryogenic nitrogen initially liquid and later liquid nitrogen N2 N2 cooled. The inner container 6 is not actively cooled. Upon cooling of the thermal shield 21, the still remaining in the gap 12 vacuum residual gas on the thermal shield 21st frozen out. As a result, when filling the inner container 6 with the liquid helium He, it is possible to prevent the residual vacuum gas from being frozen on the outside of the inner container 6, thus contaminating the metallically bright surface of the copper layer of the insulating element of the inner container 6. As soon as the thermal shield 21 and the coolant reservoir 14 are completely cooled and the coolant reservoir 14 is again completely filled with nitrogen N 2, the inner reservoir 6 is filled with the liquid helium He.

The transport container 1 can now be transported to transport the helium He

Transport vehicle, such as a truck or a ship, spent. Here, the thermal shield 21 is continuously cooled by means of the liquid nitrogen N2. The liquid nitrogen N2 is consumed and boiling in the cooling lines 26. Gas bubbles are formed by the in the

Cooling system 13 with respect to the direction of gravity g at the highest arranged phase separator 35 supplied. As a result, the fluid level drops in the

Interior 47 of the phase separator 35 from, whereby the float 49 drops and the axis 50 rotates about the axis of rotation 54, whereby the valve body 52 is lifted from the valve seat 53. In this way, the gaseous nitrogen N ₂ is blown off via the blow-off 46th Once the gaseous nitrogen N _{2 is} removed from the cooling system 13, liquid nitrogen N ₂ flows into the phase separator 35, whereby the float 49 floats again and the valve body 52 is pressed onto the valve seat 53. The opening and closing of the phase separator 35 takes place in the Hertz range. Due to the inertia of the counterweight 51 can be prevented that the float 49 during transport, for example, by vibrations, unintentionally accelerated, causing the valve body 52 could lift off the valve seat 53. As a result, an undesirable loss of nitrogen N2 can be prevented. Because the thermal shield 21 is also arranged between the coolant reservoir 14 and the inner reservoir 6, it is possible reliably to ensure that the inner reservoir 6 is adequately cooled even with a sinking level or liquid level of nitrogen N 2 in the coolant reservoir 14. Characterized in that the inner container 6 is completely surrounded by the thermal shield 21, it is ensured that the inner container 6 is surrounded only by surfaces corresponding to the boiling point (1, 3 bara, 79.5 K) of nitrogen N ₂ Have temperature. As a result, between the thermal shield 21 (79.5 K) and the inner container 6 (4.2 - 6 K), only a small temperature difference.

As a result, the holding time for the liquid helium He can be significantly extended compared to known transport containers. Heat from the inner container 6 to the thermal shield 21 is transmitted only by radiation and residual gas line. In particular, the transport container 1 has a helium holding time of at least 45 days, and the supply of liquid nitrogen N 2 is sufficient for at least 40 days. Although the present invention has been described with reference to embodiments, it is variously modifiable.

Used reference signs

1 transport container

2 outer containers

3 base section

4 lid section

5 lid section

6 inner container

7 gas zone

8 liquid zone

9 base section

10 lid section

1 1 lid section

12 space

13 cooling system

14 coolant tank

15 basic section

16 lid section

17 cover section

18 gas zone

19 liquid zone

20 space

21 shield

22 basic section

23 lid section

24 cover section

25 space

26 cooling line

27 section

28 section

29 section

30 section

31 connecting cable

32 distributors

33 collectors

34 connection conductor 35 phase separator

36 housing

37 basic section

38 cover section 39 cover section

40 inner housing

41 basic section

42 cover section

43 Cover section 44 Insulation space

45 connecting cable

46 discharge line

47 interior

48 floats 49 floats

50 axis

51 counterweight

52 valve body

53 valve seat

54 axis of rotation

55 valve

56 baffle plate

57 Blow-off valve A Axial direction g Direction of gravity

H horizontal

Hey helium

H2 hydrogen

length

Mi central axis

N ₂ nitrogen

O2 oxygen α angle

ß angle

Claims

claims

1. Transport container (1) for helium (He), with an inner container (6) for

Receiving the helium (He), a coolant tank (14) for receiving a cryogenic liquid (N2), an outer container (2), in which the

Inner container (6) and the coolant container (14) are accommodated, and a thermal shield (21) which is actively cooled by means of the cryogenic liquid (N2), wherein the thermal shield (21) has a tubular base portion (22), in the the inner container (6) is accommodated and has a cover section (23, 24) which terminates the base section (22) and which is arranged between the inner container (6) and the coolant container (14), and between the inner container (6) and the coolant tank (14)

Intermediate space (20) is provided, in which the cover portion (23, 24) of the thermal shield (21) is arranged. 2. Transport container according to claim 1, wherein the thermal shield (21) in a between the inner container (6) and the outer container (2) provided evacuated intermediate space (12) is arranged.

3. Transport container according to claim 1 or 2, wherein the thermal shield (21) has two lid portions (23, 24) which terminate the base portion (22) on both sides of the front side.

4. Transport container according to one of claims 1 - 3, wherein the thermal shield (21) on the inner container (6) nor on the outer container (2) is supported.

5. Transport container according to one of claims 1 - 4, wherein the thermal shield (21) is fluid-permeable. 6. Transport container according to one of claims 1-5, wherein the thermal shield (21) made of an aluminum mini umwerkstoff is made.

7. Transport container according to one of claims 1-6, wherein the thermal shield (21) for the active cooling of the same at least one cooling line (26), in which the cryogenic liquid (N2) is receivable.

Transport container according to claim 7, wherein the coolant container (14) in

Fluid communication with the at least one cooling line (26), so that the cryogenic liquid (N2) from the coolant container (14) flows into the at least one cooling line (26) when the cryogenic liquid (N2) in the at least one cooling line (26) partially evaporated.

Transport container according to claim 7 or 8, wherein the at least one cooling line (26) on the base portion (22) and / or on the lid portion (23, 24) of the thermal shield is provided and / or wherein the base portion (22) cohesively with the lid portion (23, 24) is connected.

Transport container according to one of claims 7 - 9, wherein the at least one cooling line (26) relative to a horizontal (H) has a slope.

Transport container according to claim 10, further comprising a phase separator (35) for separating a gaseous phase of the cryogenic liquid (N2) from a liquid phase of the cryogenic liquid (N2), wherein the at least one cooling line (26) is arranged so that in the direction the phase separator (35) has a positive slope.

Transport container according to one of claims 7 - 1 1, further comprising a plurality, in particular six, cooling lines (26).

Transport container according to one of claims 1-12, wherein the cover portion (23, 24) of the thermal shield (21) the shield coolant container (14) completely against the inner container (6).

14. Transport container according to one of claims 1-13, wherein the coolant container (14) in an axial direction (A) of the inner container (6) next to the inner container (6) is arranged.

15. Transport container according to one of claims 1-14, wherein the thermal shield (21) completely encloses the inner container (6).