EP3921583B1 - Transport container - Google Patents

Description

The invention relates to a transport container for transporting temperature-sensitive transport goods, comprising a chamber for accommodating the transport goods and a shell enclosing the chamber and equipped with a door device, the door device for closing a door opening of the shell comprising at least one door leaf, with at least one inner peripheral seal between the at least one door panel and the door opening and at least one outer peripheral seal between the at least one door panel and the door opening are provided.

When transporting temperature-sensitive goods, such as pharmaceuticals, over periods of several hours or days, specified temperature ranges must be observed during storage and transport in order to ensure the usability and safety of the goods to be transported. Temperature ranges of 2 to 25°C, in particular 2 to 8°C or 15 to 25°C, are specified as storage and transport conditions for various medicinal products.

To ensure that the desired temperature range is permanently and verifiably maintained during transport, transport containers with special insulating properties are used. These containers, as known from DE8631174U and EP0805321 , are equipped with passive or active temperature control elements.

Active temperature control elements require an external energy supply for their operation. They are based on the conversion of a non-thermal form of energy into a thermal one form of energy. The release or absorption of heat takes place, for example, as part of a thermodynamic cycle, such as by means of a compression refrigeration machine. Another design of active temperature control elements works on the basis of the thermoelectric principle, with so-called Peltier elements being used. Because of the complex construction of the active temperature control elements, containers of this type are expensive and relatively large. Furthermore, they are dependent on an energy supply due to the system. If there is no energy supply, the containers cannot be cooled or heated.

Passive temperature control elements do not require an external supply of energy during use, but use their heat storage capacity, with heat being released or absorbed depending on the temperature level to or from the interior of the transport container to be temperature-controlled. However, such passive temperature control elements are exhausted as soon as the temperature equalization with the interior of the transport container is complete.

A special form of passive temperature control elements are latent heat storage devices, which can store thermal energy in phase change materials whose latent heat of fusion, heat of solution or absorption heat is significantly greater than the heat that they can store based on their normal specific heat capacity. A disadvantage of latent heat storage devices is the fact that they lose their effectiveness as soon as the entire material has completely gone through the phase change. However, by performing the opposite phase change, the latent heat storage device can be recharged.

When transporting transport containers by air freight, transport containers must enable pressure equalization between the interior of the transport container and the pressurized cabin of the aircraft, especially since the cabin pressure in the passenger cabin and in the cargo hold is set lower than the ambient air pressure during take-off and landing. For pressure equalization, transport casks are usually equipped with a valve or a door seal which, when a predetermined differential pressure between the environment and the cask chamber is exceeded, allows an air flow from the cask chamber to the outside (when climbing) or from the outside into the cask chamber (when descending). In the latter case, however, warm ambient air enters the container interior with the air flow, which has a significantly colder temperature than the environment, so that the dew point can be undershot and water from the air can condense. The occurrence of condensate in the container chamber is undesirable because it affects the transported goods.

The present invention therefore aims to further develop a transport container of the type mentioned at the outset such that the occurrence of condensate in the container chamber can be reliably avoided.

To solve this problem, the invention in a transport container of the type mentioned essentially consists in that the inner and the outer seal each comprise at least one sealing element that can be displaced by the pressure difference and which allows air to pass from the outside when a predetermined pressure difference is exceeded opens inwards or vice versa, that a buffer space delimited by the inner and the outer seal is arranged and that a temperature control element is provided in order to cool the buffer space.

The invention is thus based on the idea of cooling the air entering from the environment due to pressure equalization before it enters the interior of the container chamber. For this purpose, a buffer space is created, which is formed between the outer and the inner circumferential seal and into which the ambient air flows before it enters the container chamber. A temperature control element ensures that the buffer space is cooled. Due to the pre-cooling of the ambient air, drying also takes place, with any condensate occurring along the flow path of the air upstream of the container chamber and in particular in the buffer space, but in any case not in the container chamber itself.

The air flowing in from the environment when the pressure is equalized passes through the outer circumferential seal between the at least one door leaf and the door opening, with this seal comprising at least one sealing element that can be displaced by the pressure difference, so that when a predetermined pressure difference is exceeded, the ambient air can flow inwards into the buffer space . The buffer space forms a buffer in which the air is pre-cooled and any condensate is collected. When the pressure is equalized, the pre-cooled air passes through the at least one inner circumferential seal between the at least one door panel and the door opening, so that the pre-cooled air reaches the container chamber.

Because air can only pass when a predetermined pressure difference is exceeded, the amount of air flowing in can be kept so low that the heat transfer from the air to the components delimiting the buffer space or the temperature control element, which is required for pre-cooling the air, is ensured. The at least one sealing element is preferably designed in such a way that it allows air to pass through at a pressure difference of 200-300 mbar.

With regard to the circumferential configuration of the at least one inner and the at least one outer seal, according to a preferred embodiment, the buffer space arranged between the inner and the outer seal is annular. The ambient air can therefore flow into the buffer space from all sides.

In particular, it is provided here that the buffer space is delimited by the at least one door leaf and by a surface of the shell that forms the door opening.

Furthermore, it is preferably provided that the temperature control element is arranged in the region of the casing facing the buffer space in order to cool the outer surface of the casing that delimits the buffer space. This makes it possible to also use a temperature control element arranged in the shell, which was originally intended for the temperature control of the chamber, for the temperature control of the buffer space.

According to a preferred embodiment, the door device is double-walled and includes to close the Door opening of the shell at least one inner door panel and at least one outer door panel, wherein the at least one inner peripheral seal is provided between the at least one inner door panel and the door opening and the at least one outer peripheral seal is provided between the at least one outer door panel and the door opening and wherein the Buffer space between the at least one inner door panel and the at least one outer door panel is arranged. In this embodiment, the buffer space is therefore arranged in a double-wall structure of the door device and comprises an intermediate space between an outer and an inner door panel of the door device. As a result, the volume of the buffer space can be maximized without having to significantly increase the overall size of the transport container. In particular, a larger area is available for the temperature control of the buffer space, namely preferably the inner surface of the outer door panel facing the buffer space and/or the outer surface of the inner outer door panel facing the buffer space.

The outer and the inner door leaf can preferably be opened and closed separately, i.e. the outer door leaf and then the inner door leaf must be opened first in order to get into the container chamber. Alternatively, however, the design can also be such that the outer and the inner door leaf can be opened and closed together. In particular, the outer and the inner door leaf can form two layers of a door, between which the buffer space mentioned is provided.

According to a preferred embodiment, it is provided that the at least one inner door leaf includes the temperature control element, which is designed to surround the buffer space facing outer surface of the at least one inner door panel to cool. The tempering element can be arranged in the inner door leaf, with the heat transfer into the buffer space being able to take place via the correspondingly large surface of the door leaf. The temperature control element used for cooling the buffer space can preferably be the same temperature control element that is also used for the temperature control of the container chamber. In this way, a particularly energy-efficient design is achieved, in which hardly any additional energy is required to cool the buffer space.

The temperature control element is preferably designed to keep the buffer space or the outer surface of the at least one inner door leaf facing the buffer space at a temperature which is at most 5-10°C above, preferably at most 2-5°C above the temperature of the chamber. This effectively prevents condensation in the container chamber. The temperature of the container chamber is maintained at, for example, 2 to 8°C or 15 to 25°, with the buffer space having the same or a slightly higher temperature.

The temperature control element is preferably designed as a cooling element, with an embodiment as an active or as a passive cooling element being possible.

The temperature control element particularly preferably comprises a latent heat store, ie an element that stores thermal energy in a phase change material whose latent heat of fusion, heat of solution or heat of absorption is significantly greater than the heat that they can store due to their normal specific heat capacity. as Possible phase change material are paraffin, for example n-tetradecane or n-hexadecane, esters, for example methyl esters, linear alcohols, ethers, organic anhydrides, salt hydrates, water-salt mixtures and/or salt solutions. Preferred phase transition materials include paraffins and salt mixtures, such as RT5 from Rubitherm or paraffins from Sasol.

It is preferably provided here that the phase change material has a phase transition temperature of 3-10°C, in particular approx. 5°C. A transport container with a latent heat store having such a phase change material can be used particularly well for the transport of medicines.

The latent heat accumulator can preferably be designed as a plate-shaped element. An advantageous embodiment results when the plate-shaped element has a large number of honeycomb-shaped hollow chambers, in particular, which are filled with the latent heat storage material, with a honeycomb structure element according to FIG WO 2011/032299 A1 is particularly advantageous.

Alternatively, it can be provided that the temperature control element is designed as an active temperature control element and preferably comprises a compression refrigeration machine or a Peltier element.

• ein Verdunstungselement mit einer Kühlfläche,
• ein Trocknungsmittel zur Aufnahme von im Verdunstungselement verdunstetem Kühlmittel,
• eine Transportstrecke zum Transport des verdunsteten Kühlmittels zum Trocknungsmittel,
• ggf. eine mit dem Verdunstungselement in Fluidverbindung bringbare Vorratskammer für das Kühlmittel.

Furthermore, it can be provided that the temperature control element has an evaporative cooling system, comprising

• an evaporation element with a cooling surface,
• a desiccant for absorbing coolant evaporated in the evaporation element,
• a transport route for transporting the evaporated coolant to the desiccant,
• possibly a storage chamber for the coolant that can be brought into fluid connection with the evaporation element.

The temperature control element preferably includes both a latent heat store and an evaporative cooling system. The combination of two different cooling systems, namely an evaporative cooling system with a latent heat storage device, has a number of advantages. The performance of the evaporative cooling system can be reduced so that it can be made smaller and lighter. The total cooling capacity can be split between the evaporative cooling system and latent heat storage. The cooling system can be designed so that when the performance of the evaporative cooling system is no longer sufficient and the temperature of the chamber increases, the additional cooling capacity is drawn from the latent heat storage device, which requires energy for the phase transition from solid to liquid.

The cooling system can preferably be designed in such a way that the phase transition temperature (solid to liquid) of the latent heat storage device is selected to be lower than the temperature resulting from the cooling capacity of the evaporative cooling system. With the evaporative cooling system, the temperature of the chamber and/or the buffer space can preferably be reduced to a temperature of 12-20°C, with further cooling to a temperature in the range of 2-8°C being carried out with the aid of the latent heat accumulator. With this combination, the desiccant can

Evaporative cooling system can be worked with a higher relative humidity, whereby the amount of desiccant can be reduced. The amount of latent heat storage can also be reduced, since it only has to provide the energy for cooling from the range of 12-20°C to the range of 2-8°C.

Another advantage is that a partially charged (i.e. not fully crystallized) latent heat storage device can be used to protect the chamber against hypothermia or to keep it within the desired temperature range of e.g. 2-8°C when the outside temperature falls below the level of the desired temperature range drops.

In a preferred embodiment, in which the goods to be transported in the chamber are to be kept in a temperature range of 2-8°C, the latent heat accumulator is designed with a phase transition temperature of approx. 4-6°C.

If the transport container is stored in a cold store (e.g. bonded warehouse) for a long period of time (e.g. several days), e.g. at a temperature of 2-8°C, and the evaporative cooling system is set to a cooling capacity to achieve a temperature higher than that prevailing in the cold store temperature is set, the evaporative cooling system is not active during the storage period, so no coolant is consumed. Furthermore, the period of storage can be used to charge the latent heat store, which happens automatically in the cold store at a temperature of, for example, below 6°C if the phase transition temperature of the latent heat store is accordingly 6°C. As a result, with minimal Design of the two systems (latent heat storage and evaporative cooling system) a longer service or transport time of the transport container can be achieved than if only one cooling system were used alone.

A further advantage arises when the evaporative cooling system provides more cooling capacity than is required. The excess cooling capacity can then be used to recharge the latent heat storage device, i.e. return it to the solid or crystallized state.

In order to improve the sealing of the door device, it can be provided that at least two outer seals are provided one behind the other and at a distance from one another in the direction of an air flow from the outside into the buffer space, each comprising a sealing element that can be displaced by the pressure difference, which, when a predetermined Pressure difference opens an air passage from the outside into the buffer space. The provision of at least two cascading outer seals also has the effect that a further buffer volume is created between the first and the second outer seal for the air flowing from the environment into the buffer space when the pressure is equalized. Three seals effective one behind the other are particularly preferably provided.

The outer door leaf can also be equipped with a temperature control element. In particular, it can be provided that the at least one outer door leaf comprises a layer with a latent heat accumulator.

Alternatively or additionally, the at least one outer door leaf can comprise a thermal insulation layer.

In terms of construction, the sealing element of the outer and/or inner seal can be designed to enable pressure equalization in such a way that it is designed as an elastically deflectable sealing lip of the seal. In this case, the sealing lip can preferably be formed in one piece with the seal.

The inner and/or outer seal can be attached to the at least one door leaf, preferably to the inner or outer door leaf, or also to the door opening, with a circumferential arrangement of the seal being advantageous in any case in order to ensure that the door device is sealed on all sides . If the seal is attached to at least one door leaf and, as is fundamentally conceivable, two door leaves are provided which can be pivoted in opposite directions in the sense of a double-wing door, each door leaf is provided with a circumferential seal.

In an embodiment with two outer seals arranged one behind the other, it is preferably provided that one of the two outer seals is fastened to the outer door leaf and the other of the two outer seals is fastened to the door opening.

In order to collect any condensate that may occur in the buffer space, it is preferably provided that the buffer space has a collection chamber for condensate or is connected to it.

The invention is explained in more detail below with reference to an exemplary embodiment shown schematically in the drawing. in this show 1 a perspective view of a cuboid transport container in a first embodiment with the doors open, 2 a cross section of the transport container along the plane II 1 , 3 a detailed view of the cross section according to FIG 2 and 4 a cross section of the transport container analogous to 2 , but in a modified version.

In 1 a transport container 1 is shown, which is cuboid and whose shell 2 surrounds a container chamber 3 on five sides. On the sixth side, the shell 2 has a door opening 4 which can be closed with an inner door and an outer door. The inner door comprises two inner door leaves 5, which can be swung open in opposite directions in the manner of a double-wing door. The outer door comprises an outer door panel 6. The shell 2, the inner door panels 5 and the outer door panel 6 comprise heat-insulating material and temperature control elements which ensure that the container chamber 3 is kept at a predetermined temperature level of, for example, 2-8°C or 15- 25°C remains.

In the cross-sectional view according to 2 the door leaves 5 and 6 are shown closed and completely close the door opening.

In the detail view according to 3 the sealing of the gap 7 present between the door device and the shell 2 is shown. Between the outer door leaf 6 and the shell 2 is a first outer peripheral seal 8 provided, which is attached to an outer peripheral edge portion of the door leaf 6 formed with a smaller thickness. A second and a third outer seal 9 and 10 are provided further inwards between the outer door leaf 16 and the shell 2, which are also formed circumferentially and provide an additional seal. The second outer seal 9 is attached to the shell 2 and the third outer seal 10 is attached to the door leaf 6 . The seals 8, 9 and 10 are each arranged on the front side, so that they are compressed by the closing movement of the door leaf 6.

An inner seal 11 is arranged between the inner door panel 5 and the shell 2, which is attached to the narrow side of the door panel 5 and the door panel 5 surrounds the circumference.

The gap 7 leads into an intermediate space 12 which is formed between the two parallel door leaves 5 and 6. If there is a pressure difference between the container chamber 3 and the environment, the seals 8, 9, 10 and 11 are deformed in such a way that the pressure is equalized and a certain amount of air 13 passes through the gap 7 into the intermediate or buffer space 12 and the container chamber 3 can. The buffer space 12 serves as a buffer space in which a volume of air is stored and pre-cooled by means of a temperature control element (not shown), the temperature control element preferably being arranged in the inner door panel 5 in order to fill the buffer space 12 via the buffer space-facing outer surface of the door panel 5 to cool. The air in the buffer space 12 is thereby cooled to a temperature that is low or the temperature prevailing in the container chamber 3 corresponds to the temperature above, whereby any condensation of water in the buffer space 12 takes place before this air enters the container chamber 3.

In the alternative embodiment according to 4 If the door device is not double-walled with an intermediate space, it comprises only the door leaf 14 or, in the case of a double-leaf door, two door leaves 14. A first outer circumferential seal 15 is provided between the door leaf 14 and the shell 2, which is formed with a smaller thickness peripheral edge portion of the door leaf 14 is attached. A second outer seal 16 is provided further inwards between the door leaf 14 and the shell 2, which is also formed circumferentially and provides an additional seal. The seals 15 and 16 are each arranged on the front side, so that they are compressed in the closing direction by the closing movement of the door leaf 14 .

Furthermore, an inner seal 18 is arranged between the door leaf 14 and the shell 2, which is attached to the narrow side of the door leaf 14 and the door leaf 14 surrounds the circumference. A second inner seal 19 can optionally be arranged next to the inner seal 18 .

The gap 7 leads into a first space 17 which is formed between the two outer seals 15 and 16 . The buffer space 12 adjoins the first space 17 on the inside towards the chamber 3 and is delimited on the inside by the inner seal 18 and possibly 19 . In the presence of a pressure difference between the container chamber 3 and the Surroundings, the seals 15, 16, 18 and possibly 19 are deformed in such a way that pressure equalization takes place and a certain amount of air 13 through the gap 7 into the first space 17, an equivalent amount of air from the first space 17 into the buffer space 12 and an equivalent amount of air from the buffer space into the container chamber 3. The buffer space 12 serves as a buffer in which a volume of air is kept in stock and is pre-cooled by means of a temperature control element (not shown), the temperature control element preferably being arranged in the casing 2 . If necessary, a partial temperature control or cooling of the air can already take place in the first space 17 , so that only the remaining temperature control or cooling has to take place in the subsequent buffer space 12 .

Claims (16)

1. Transport container (1) for transporting temperature-sensitive transport goods, comprising a chamber (3) for receiving the transport goods and a casing (2) which surrounds the chamber (3) and is equipped with a door device, wherein the door device comprises at least one door leaf (5,6) for closing a door opening (4) of the casing (2), wherein at least one inner circumferential seal (11; 18) is provided between the at least one door leaf (5,6) and the door opening (4) and at least one outer circumferential seal (8, 9, 10; 15,16) is provided between the at least one door leaf (5, 6) and the door opening (4), characterized in that the inner and outer seals (10, 11; 16, 18) each comprise at least one sealing element that can be displaced by a pressure difference and that, when a predetermined pressure difference is exceeded, opens an air passage from the outside to the inside or vice versa, that a buffer space (12) delimited by the inner and outer seals (10, 11; 16, 18) is arranged and that a temperature control element is provided to cool the buffer space (12).
2. Transport container according to claim 1, characterized in that the buffer space (12) is arranged between the inner and the outer seal (10,11; 16,18) and is designed in the shape of a ring.
3. Transport container according to claim 2, characterized in that the buffer space (12) is delimited by the at least one door leaf (5, 6) and by a surface of the casing (2) forming the door opening (4).
4. Transport container according to claim 1, 2 or 3, characterized in that the temperature control element is arranged in the region of the casing facing the buffer space (12) in order to cool the outer surface of the casing (2), which outer surface is delimiting the buffer space (12).
5. Transport container according to claim 1, characterized in that the door device is double-walled and comprises at least one inner door leaf (5) and at least one outer door leaf (6) for closing the door opening (4) of the casing (2), wherein the at least one inner circumferential seal (11) is provided between the at least one inner door leaf (5) and the door opening (4) and the at least one outer circumferential seal (8,9,10) is provided between the at least one outer door leaf (6) and the door opening (4), and wherein the buffer space (12) is arranged between the at least one inner door leaf (5) and the at least one outer door leaf (6).
6. Transport container according to claim 5, characterized in that the at least one inner door leaf (5) comprises the temperature control element which is designed to cool the outer surface of the at least one inner door leaf (5) facing the buffer space (12).
7. Transport container according to claim 5 or 6, characterized in that the temperature control element is designed to keep the buffer space (12) or the outer surface of the at least one inner door leaf (5) facing the buffer space (12) at a temperature that is at most 5-10°C above, preferably at most 2-5°C above the temperature of the chamber (3).
8. Transport container according to any one of claims 1 to 7, characterized in that the temperature control element is designed as a cooling element.
9. Transport container according to any one of claims 1 to 8, characterized in that the temperature control element comprises a latent heat storage.
10. Transport container according to any one of claims 1 to 9, characterized in that the temperature control element is designed as an active temperature control element and preferably comprises a vapor-compression refrigeration system or a Peltier element.
11. Transport container according to any one of claims 1 to 11, characterized in that the temperature control element comprises an evaporative cooling system, comprising

    - an evaporation element with a cooling surface,

    - a desiccant to absorb coolant that has evaporated in the evaporation element,

    - a transport path for transporting the evaporated coolant to the desiccant,

    - possibly a storage chamber for the coolant that can be brought into fluid connection with the evaporation element.
12. Transport container according to any one of claims 1 to 11, characterized in that at least two outer seals (8, 9, 10) are provided, one behind the other and at a distance from one another in the direction of an air flow from the outside into the buffer space (12), wherein each of said two outer seals comprises a sealing element that is displaceable by a pressure difference and that opens an air passage from the outside into the buffer space (12) when a predetermined pressure difference is exceeded.
13. Transport container according to any one of claims 1 to 12, characterized in that the at least one door leaf (5, 6), in particular the outer door leaf (6), comprises a layer with a latent heat storage.
14. Transport container according to any one of claims 1 to 13, characterized in that the at least one door leaf (5, 6), in particular the outer door leaf (6), comprises a thermal insulation layer.
15. Transport container according to any one of claims 1 to 14, characterized in that the sealing element is designed as an elastically deflectable sealing lip of the seal (8, 9, 10, 11).
16. Transport container according to any one of claims 1 to 15, characterized in that the buffer space (12) comprises a collecting chamber for condensate or is connected to the same.

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