Container for transporting temperature-sensitive goods

Abstract

The invention relates to a container (1) for transporting temperature-sensitive goods, comprising a wall structure enclosing a loading space for receiving goods and comprising an opening for loading and unloading the loading space, the container further comprising door means (4, 5) for selectively opening and closing the opening, at least one coolant reservoir (7) for accommodating a coolant is arranged and / or fastened in the loading space, on at least one wall of the wall structure, in particular on the upper wall, the at least one coolant reservoir (7) or the coolant contained therein can be exchanged via an open coolant access section, characterized in that the coolant reservoir (7) is arranged and / or fastened in the loading space. A barrier element (15) is arranged in the rest of the opening to separate the loading space from the outside when the door means (4, 5) are in the open position.

Description

Technical Field

[0001] The present invention relates to a container for transporting temperature-sensitive goods, the container comprising a wall structure which surrounds a loading space for receiving the goods and comprises an opening for loading and unloading the loading space, the container further comprising a door device for selectively opening and closing the opening, wherein at least one coolant reservoir for containing a coolant is arranged and / or fastened in the loading space, on at least one wall of the wall structure, in particular on an upper wall, wherein the at least one coolant reservoir or the coolant contained therein can be exchanged via a coolant access portion of the opening. Background Art

[0002] In pharmaceutical supply chain and logistics, a wide range of products need to be transported in a temperature controlled environment. Several temperature domains can be controlled, ranging from room temperature (approximately +25°C) to deep freeze temperatures (ie, down to -90°C).

[0003] To meet this need, shipping containers are used that maintain internal temperature for a sustained amount of time. Such containers limit heat transfer between the surrounding environment and its loading space by preventing three types of heat transfer (conduction, convection, and radiation). When the container is closed, several insulating layers integrated into the container structure prevent all three types of heat transfer.

[0004] However, such transport containers are regularly opened to load and unload them or to perform routine operations during transportation. During this phase, all three types of heat transfer are not well taken care of, and mass transfer of air occurs between the internal loading space and the external environment.

[0005] Existing types of shipping containers are generally classified by the International Air Transport Association (IATA) as either active containers or passive containers. Active containers are maintained at a target temperature with the aid of a heat pump, thereby requiring a power source to function. Passive containers do not require energy input and rely on their insulation and a passive coolant to maintain their temperature, such as a phase change material (PCM), including, for example, ice or dry ice.

[0006] Under standard operating conditions, active and passive containers are only opened to load and unload the delivered goods. However, depending on the type of coolant, some passive containers may need to be opened during transportation in order to refill them with coolant and ensure the desired internal temperature. This is especially true for containers cooled with dry ice.

[0007] Opening a container creates challenging conditions for the cargo being transported. When the container door is opened, the cold air in the load space leaves the container within seconds due to the density difference between the gases present inside the load space and outside of it. This density difference is due to the temperature difference between the two environments and can be estimated using the ideal gas law.

[0008] For controlled temperatures between +25°C and -20°C, this can be avoided by performing all operations requiring the container to be opened in a temperature controlled environment. However, when dealing with frozen or deep-frozen containers with a target temperature below -20°C, it is rarely possible to obtain an environment that is controlled at temperatures as low as the load space.

[0009] This raises two issues for goods shipped in containers:

[0010] - Once the cold air leaves the loading space, the transported goods will find themselves in an environment that is not at exactly the right temperature compared to the requirement. This can spoil the transported goods when the operator performs a refilling operation.

[0011] After the container is closed, the hot air that has entered the container needs to be cooled down again to the desired temperature, which significantly affects the operating time of the container.

[0012] Finally, according to the ideal gas law, the greater the temperature difference between the internal and external environments, the greater the difference in density between the air inside and outside the container. This means that the two problems described above are amplified for frozen and deep-frozen containers, which are also the containers used to transport the most sensitive products (such as vaccines). Summary of the invention

[0013] The present invention is therefore intended to protect such sensitive cargo from potential temperature excursions during transport, particularly when containers need to be opened to refill them with coolant, and thus extend the operating time of the transport containers, thereby providing additional safety in the transportation of life-saving medicine.

[0014] In order to achieve this and other objects, the invention provides a container of the type mentioned at the outset, comprising at least one coolant reservoir arranged and / or fastened in the loading space on at least one wall of the wall structure, in particular on the upper wall, wherein the at least one coolant reservoir or the coolant contained therein can be exchanged via the coolant access portion of the opening, and the container is characterized by a barrier element which is arranged in the remainder of the opening to separate the loading space from the outside when the door arrangement is in the open position. Of course, the remainder of the opening is the portion of the opening which is not occupied by the coolant access portion of the opening.

[0015] The invention is based on the idea of ​​limiting the air flow between the internal loading space and the external environment, thereby preventing or reducing the mass transfer of cold air from the interior to the outside of the container and preventing hot air from entering the loading space when the container door(s) are opened. According to the invention, the air exchange when the container door(s) are opened is limited by means of a barrier element. The barrier element protects the loading space from external heat. In other use cases, the barrier element can be useful for preventing or reducing the mass transfer of warm air from the interior to the outside of the container and preventing cold air from entering the loading space when the container door(s) are opened.

[0016] The blocking element is arranged so as not to hinder access to the coolant reservoir for exchanging or refilling it. The invention therefore provides that the blocking element is arranged to keep the coolant access portion of the container opening clear and is therefore arranged in the remaining portion of the opening.

[0017] In order to minimize energy losses during opening of the door(s), the barrier element should be configured to cover as much as possible the remainder of the opening, i.e. the air flow cross-sectional area between the loading space and the environment of the container. Therefore, a preferred embodiment of the invention provides that the barrier element covers at least 50%, preferably at least 80%, more preferably at least 90% of the air exchange flow cross-sectional area between the loading space and the outside.

[0018] Herein, the air exchange flow section area is preferably defined as a rectangular area enclosed by three walls of the wall structure and a coolant reservoir arranged on a fourth wall, preferably the upper wall.

[0019] Due to the higher density of cold air than warm air, cold air tends to escape from the loading space in the lower region of the available air exchange flow cross-sectional area. Therefore, a preferred embodiment provides that the distance between the barrier element and the bottom wall of the wall structure is less than 50 mm, preferably less than 30 mm.

[0020] Furthermore, the barrier element is preferably arranged to cover at least 70%, preferably at least 90%, more preferably at least 98% of the width of the opening.

[0021] In order to further improve the barrier effect of the barrier element, a preferred embodiment provides that the barrier element comprises an elastic sealing element on at least one lateral edge thereof.

[0022] Preferably, the barrier element is substantially impermeable to ambient air.

[0023] The barrier element may be made from a sheet of material such as metal, wood, fabric, plastic or a combination thereof. Preferably, the barrier element is made from metal, which is advantageous due to its strength and rigidity.

[0024] By limiting the air exchange flow profile area between the two spaces as much as possible, the airflow is restricted as much as possible. The mass transfer of cold air can be calculated as follows. The pressure difference between the top and bottom of the container can be considered linear and expressed as ΔP 竖直 = -ρgΔh. Herein, ρ represents the density of the gas, g represents the gravity of the earth, and h represents the height along which the pressure difference is evaluated. Assuming that the height of the container is small, the density of each volume should be approximately constant.

[0025] The ideal gas law PV = nRT can be used to estimate the density of the gas in each volume (in the container and outside the container). In this equation, P represents the pressure in a given volume, V represents the volume, n represents the amount of substance of the gas occupying the volume, R represents the ideal gas constant, and T represents the temperature of the gas in the volume under consideration.

[0026] Since there is a temperature difference between the inside and outside of the container, the density and therefore the pressure of the gas is different inside and outside the container. Thus, this pressure difference drives the cold air out of the container.

[0027] Finally, the mass flow rate through the constricted surface area can be expressed as Here, C f represents the friction coefficient, S represents the surface area over which the gas can flow, and ΔP 两端 represents the pressure difference across the exchange region, and ρ represents the density of the gas flowing out through the contraction region. ΔP 两端 Expressed as P 进 -P 出 The internal and external pressures are based on ΔP 竖直 The expression for this is expressed in terms of and varies depending on the height at which the opening is positioned.

[0028] This shows two important relationships:

[0029] First, mass flow is proportional to the exchange surface area And the time it takes for the cold air to leave the container is inversely proportional to the exchange surface area This shows that the exchange surface covered by the barrier element is a decisive factor for the efficiency of the barrier element.

[0030] Second, the mass flow rate is proportional to the square root of the height at which the opening is located. And the time required for the cold air to leave the container is inversely proportional to the square root of the height at which the opening is located This shows that a second determining factor for the efficiency of the barrier element is the position of the opening not covered by the barrier element. In fact, since the pressure varies vertically, the container empties faster with the opening at the bottom.

[0031] The container of the present invention is preferably configured for transporting temperature-sensitive goods (such as pharmaceuticals) over a period of several days, wherein a specific temperature range must be maintained during storage and transportation in order to ensure the availability and safety of the transported goods. Preferably, the container of the present invention is configured to maintain the temperature of the load space at a temperature of -60°C to -80°C for at least 3-5 days, which corresponds to the specific storage and transportation conditions of various drugs and vaccines.

[0032] Preferably, dry ice (solid CO2) is used as a coolant, which is ideal for this temperature range due to its sublimation temperature of approximately -78.5°C. In addition, for the phase transition from solid to gas (sublimation), an amount of energy of 571.1 kJ / kg is required, which achieves a very large cooling effect at low weight compared to commercially available phase change materials (≈200 kJ / kg) in a similar temperature range. Another advantage of dry ice is its non-residue dissolution. It is only necessary to ensure the safe discharge of gaseous carbon dioxide, which occupies a volume of about 760 times that of dry ice at normal pressure and a temperature of 0°C. For air transport, there is usually a maximum sublimation rate or amount of dry ice per flight that must not be exceeded. Therefore, minimizing the amount of dry ice used per kilogram of cargo directly affects the total amount of cargo allowed per flight.

[0033] Efficient use of a coolant, such as dry ice, can preferably be achieved if the wall structure and / or the door arrangement is designed as a layered structure which comprises, from the outside to the inside, a first insulating layer, optionally a second insulating layer, and an energy distribution layer which delimits the loading space and is made of a material with a thermal conductivity >100 W / (mK).

[0034] By combining a coolant reservoir for accommodating a coolant, such as dry ice, which is arranged and / or fastened in the loading space, on at least one wall, with an energy distribution layer delimiting the loading space, an efficient heat distribution over the entire inner shell is achieved, so that the amount of coolant can be minimized. Due to the heat distribution, it is sufficient here to arrange the coolant on only one wall. However, it is also conceivable to provide the coolant on two or more walls. The high thermal conductivity inner shell allows a very efficient use of dry ice, wherein the heat input at any position of the container is conducted to the coolant and absorbed there, so that asymmetric heat input is compensated and uneven consumption of dry ice is avoided.

[0035] Preferably, the at least one coolant reservoir or its supporting structure is directly connected to the energy distribution layer in a thermally conductive manner, the thermally conductive connection preferably having a thermal conductivity of >100 W / (mK).

[0036] The energy distribution layer delimiting the load space is preferably in direct contact with the load space, so that a direct heat transfer between the load space and the energy distribution layer is ensured.

[0037] Since the heat distribution over the entire load space does not require convection, the load space can be fully utilized for the payload. No air gaps are required to maintain air circulation.

[0038] The very efficient use of dry ice, through the internal heat distribution combined with the double insulation of the container wall, results in a very efficient use of dry ice at an average external temperature of 30°C with a dry ice quantity of 80-120 kg and a payload volume of 1 to 1.5 m 3 And the external volume is 2-4m 3 This is a significant improvement of 2 to 20 times compared to conventional solutions, allowing a payload volume of 1 to 1.5m per RKN aircraft position. 3 Alternatively, it allows 4 transport containers to be arranged on the PMC pallet for a total payload volume of 4x1.5m 3 or 6m 3 .

[0039] With regard to the layered structure of the container wall, provision is preferably made that the first insulation layer, the second insulation layer (if present) and the energy distribution layer lie directly on top of one another.

[0040] Preferably, the first insulating layer, the second insulating layer (if present) and the energy distribution layer surround the loading space on all sides and without interruption, except for the opening. The energy distribution layer completely surrounds the loading space except for the opening, i.e. each wall of the container comprises an energy distribution layer as the innermost layer, the energy distribution layers of all walls being connected to each other in a thermally conductive manner in adjacent edges and corners, i.e. by means of joints with a thermal conductivity of >100 W / (mK).

[0041] Preferably, the door arrangement also comprises a layered structure for the container wall structure. In particular, the door arrangement consists of a layered structure which comprises, from outside to inside: a first insulating layer, optionally a second insulating layer, and an energy distribution layer which delimits the loading space and is made of a material with a thermal conductivity >100 W / (mK).

[0042] In order to achieve adequate heat distribution, a thermal conductivity of the energy distribution layer of at least 100 W / (mK) is specified. The higher the thermal conductivity of the energy distribution layer selected, the more efficient the utilization of the coolant. According to a preferred embodiment, it can be provided that the thermal conductivity of the energy distribution layer of the wall structure and / or the door arrangement is at least 140 W / (mK), more preferably at least 180 W / (mK). The energy distribution layer of the container wall and / or the door arrangement can be made, for example, of aluminum, graphite or a graphite composite material, in particular of a graphite sheet coated with carbon fiber reinforced plastic on both sides. Such a material also leads to a mechanical reinforcement of the container wall at a low weight.

[0043] In the case of aluminum, 0.5-5 mm thick aluminum sheets (which have a thermal conductivity of about 150 W / (mK)) can be used, thereby distributing the local heat input across the inner shell and resulting in a uniform temperature distribution in the load space. The joints of the individual aluminum panels on the sides and corners can be reinforced with rivets so that they can withstand the forces generated by thermal stresses.

[0044] In the case of a design of an energy distribution layer made of, for example, a carbon-graphite composite plate, the composite plate may consist of a 0.2-1 mm thick graphite core laminated on both sides with 0.2-2 mm thick plates made of carbon fiber reinforced plastic (CFRP). Since graphite exhibits a thermal conductivity of up to 400 W / (mK) depending on the density, carbon-graphite composite sheets can achieve average thermal conductivity similar to or higher than comparable aluminum sheets. In addition, CFRP has a better mechanical strength to weight ratio than aluminum, allowing weight savings. Another advantage of carbon-graphite composite panels is the low coefficient of thermal expansion of CFRP. A typical value in the fiber direction is α CFK =0.6·10 -6 K -1 For comparison, the thermal expansion coefficient of common aluminum alloys is: α EN-AW 5754 =23.8·10 -6 K -1 This reduces the thermal stresses and resulting mechanical loads on the inner shell.

[0045] In a particularly preferred manner, the at least one coolant reservoir is designed as a drawer which is guided in a guide element so that it can be pulled out and pushed into the loading space. This design permits extremely simple handling, wherein the coolant can be filled or replenished without having to dismantle the container or remove the payload. The operating time of the container can be extended as required by refilling the coolant.

[0046] Preferably, the drawer(s) have dimensions such that the entire dimension of the wall of the container wall structure is covered by the drawer(s).

[0047] Preferably, the at least one coolant reservoir, in particular the drawer(s) and the drawer guides attached to the at least one wall also consist of a highly thermally conductive material, so that the introduced heat is evenly distributed over the coolant. It is preferably provided here that the at least one coolant container is made of a material with a thermal conductivity of >100 W / (mK), preferably >140 W / (mK), in particular >180 W / (mK), for example of aluminum, graphite or a graphite composite material, in particular of a graphite sheet coated with carbon fiber reinforced plastic on both sides.

[0048] In order to enable easy mounting and removal of the blocking element, a preferred embodiment provides that the blocking element is removably fixed to the wall structure and / or the guide element of the drawer. Alternatively, the blocking element may be pivotably mounted to the wall of the wall structure and / or the guide element of the drawer.

[0049] Different fixing methods can be used, including ropes, hooks, hinges, zippers, tapes, handles, glue, screws, rivets, buckles, cable ties, Velcro. The solution that guarantees the easiest handling of the heat shield is to use hooks to hang the barrier element to the coolant reservoir, in particular to the drawer guide.

[0050] The thermal insulation of the container is preferably achieved by a first insulating layer and, if necessary, a second insulating layer. The structure of the container wall with at least two insulating layers allows each insulating layer to be optimized with respect to its respective insulating function. Preferably, one of the insulating layers, in particular the first outer insulating layer, is designed to minimize heat transfer to the loading space via thermal radiation. Another insulating layer, in particular the second inner insulating layer, can be formed to minimize heat transfer to the loading space via thermal conduction.

[0051] Preferably, the first insulation layer may have a thermal conductivity of 4 to 300 mW / (mK), and the second insulation layer may have a thermal conductivity of 1 to 30 mW / (mK), wherein the first insulation layer preferably has a higher thermal conductivity than the second insulation layer.

[0052] This results in a U-value of 0.1-0.2 W / m for the transport container. 2 K, which corresponds to a very low heat input compared to containers commonly used in industry.

[0053] Regarding the design of one of the insulating layers, preferably the first insulating layer as a barrier against thermal radiation, it can comprise a heat-reflecting coating substrate, such as a substrate provided with a metal coating. Preferably, the heat-reflecting coating is formed by a metallic, in particular gas-tight coating, preferably a coating with an emissivity of <0.5, preferably <0.2, particularly preferably <0.04, such as an aluminum coating. Preferably, provision is made that the insulating layer comprises a multilayer structure of a honeycomb-shaped thermoformed plastic film, which is provided on both sides with a heat-reflecting coating, in particular an aluminum coating. An advantageous design results if the insulating layer has a plurality of, in particular honeycomb-shaped, hollow chambers, a honeycomb structural element according to WO 2011 / 032299 A1 being particularly advantageous. Alternatively, the insulating layer can be made of a conventional porous insulating material, such as polyurethane, polyisocyanurate or expanded polystyrene. Preferably, the insulating layer has a thickness of 60-80 mm.

[0054] Regarding the design of the further insulating layer, preferably the second insulating layer as a barrier against heat conduction, said insulating layer may preferably be designed as a vacuum insulation and preferably comprises or consists of a vacuum insulation panel.

[0055] Preferably, the second insulating layer has a thickness of 30-50 mm.

[0056] Preferably, the vacuum insulation panel has a porous core material as a supporting body for the vacuum present in the interior, and an airtight envelope surrounding the core material, the core material preferably consisting of aerogel, open-cell polyurethane or open-cell polyisocyanurate. The advantage of these core materials over conventional fumed silica is their lower density, which results in a weight saving over conventional vacuum panels. For example, the density of aerogel is between 80 and 140 kg / m 3 The range of fumed silica is 160-240kg / m 3 With densities of 2.5-1.0 W / mK, both materials have similar thermal conductivity properties in the range of 2-6 mW / (mK).

[0057] Alternatively, the second insulating layer may have an outer wall, an inner wall spaced apart from the outer wall, and a vacuum chamber formed between the outer wall and the inner wall, the vacuum chamber being a continuous vacuum chamber that surrounds the loading space on all sides except the opening. Therefore, this insulating layer of the container wall is designed as a double-walled vacuum container that surrounds the loading space on all sides (except the container opening). In contrast to the use of conventional vacuum panels, the insulating piece is not composed of individual vacuum elements that must be assembled to form an outer shell, but surrounds all sides of the container in one piece except the opening. Since a continuous vacuum chamber is formed between the inner wall and the outer wall of the insulating layer (the vacuum chamber surrounds the loading space on all sides except the opening), the joints originally required between the individual vacuum panels and the associated thermal bridges can be avoided. The double-walled design of the insulating layer is also self-supporting, so that in addition to insulation, it also has a stabilizing function. This means that load-bearing structural components can be eliminated.

[0058] The term "vacuum chamber" means that the space between the inner wall and the outer wall of the insulating layer is evacuated, thereby achieving thermal insulation by reducing or preventing heat conduction of gas molecules. Preferably, the air pressure in the vacuum chamber is 0.001-0.1 mbar.

[0059] Preferably, provision is made that the outer wall and the inner wall are made of sheet metal, in particular stainless steel, aluminum or titanium, and preferably have a thickness of 0.01 to 1 mm. This ensures the required stability on the one hand and an airtight design of the wall on the other hand. In such an embodiment, the inner wall of the insulating layer can simultaneously form an energy distribution layer when arranged as a second insulating layer.

[0060] In order to be able to withstand the compressive forces of the surrounding air without having to make the outer and inner walls of the insulation layer too thick, the outer and inner walls are preferably connected by a plurality of spacers, which are preferably made of a synthetic material with a thermal conductivity of <0.35 W / (m·K), such as polyetheretherketone or aramid. The spacers ensure that there is a desired distance between the outer and inner walls, so that the intermediate cavity (i.e. the vacuum chamber) is retained. Since the spacers form thermal bridges, it is advantageous to form these spacers from a material with the lowest possible thermal conductivity.

[0061] In order to further improve the thermal insulation properties of the insulation layer, a preferred further embodiment provides that a plurality of insulation foils located above each other at a certain distance are arranged in the vacuum chamber, the foil planes of the plurality of insulation foils being substantially parallel to the planes of the outer wall and the inner wall. In particular, the insulation foils are present in a stack, wherein the foil stack is preferably arranged in each wall of the container wall and extends substantially over the entire wall. Preferably, the insulation foil is arranged to surround the loading space on all sides except for the opening.

[0062] Preferably, the insulating foil is arranged in such a way that a space (protective space) remains between the inner surface of the outer wall or inner wall facing the vacuum chamber and the foil stack in each case, so that the foil stack is not compressed by possible deformation of the wall. In addition, this space provides space for structural stabilization of the spacer and facilitates vacuum handling.

[0063] A further preferred embodiment provides that the insulating foils are held spaced apart from one another by planar spacer elements which are preferably formed from a textile sheet material, in particular as a polyester nonwoven.

[0064] In particular, the insulating foil can be designed as a metal coating or a metal-evaporated plastic film. Such an insulating foil is also referred to as a super insulating film. For example, the metal coating is made of aluminum.

[0065] The overall insulation performance of the transport container naturally also depends on the insulating properties of the door arrangement closing the inner opening. As already mentioned, in this case the door arrangement can consist of a layered structure corresponding to the layered structure of the container wall and comprising, from outside to inside, a first insulating layer, a second insulating layer, and an energy distribution layer delimiting the loading space and made of a material with a thermal conductivity >100 W / (mK).

[0066] In a particularly preferred embodiment, the door arrangement comprises at least one inner door leaf and at least one outer door leaf. In particular, the door leaf is a hinged door which is attached to the container by means of hinges. The arrangement of the at least one outer door leaf and the at least one inner door leaf results in a double-layer construction, wherein the at least one outer door leaf preferably forms a first insulating layer of the door arrangement and the at least one inner door leaf forms a second insulating layer of the door arrangement, with regard to the properties and construction of the first insulating layer and the second insulating layer, reference is made to the functions and properties described above in conjunction with the insulating layer of the container wall.

[0067] Preferably, the at least one outer door leaf and the at least one inner door leaf can be opened and closed, preferably separately and independently from each other. The double-walled construction of the door arrangement results in a temperature on the outer side of the at least one inner door leaf of about 0°C (between -20°C and 8°C) at an internal temperature of -60°C to -80°C. This makes it possible to open the inner door leaf manually during operation (i.e. without risk of cold burns). Preferably, this effect is achieved by the at least one inner door leaf having an insulation performance (1 to 30 mW / (mK)) that is higher than the insulation performance (4 to 300 mW / (mK)) of the at least one outer door leaf.

[0068] In a preferred embodiment, the door arrangement comprises a single outer door leaf and two inner door leaves to form an inner double door.

[0069] Preferably, the at least one outer door leaf and the at least one inner door leaf are each dimensioned to completely cover the opening, including the coolant reservoir(s) and the barrier element. Thus, after having opened the at least one outer door leaf and the at least one inner door leaf, the loading space of the container remains at least partially closed by means of the barrier element, while the coolant reservoir (e.g., in the form of a drawer) can be pulled out of the loading space.

[0070] When transporting containers by air, the containers must allow pressure equalization between the loading space and the pressurized cabin of the aircraft, especially because the cabin pressure prevailing in the passenger cabin and the cargo hold is set to a pressure lower than that corresponding to the ambient air pressure during take-off and landing. For pressure equalization, the containers are usually equipped with valves or door seals that allow air to flow out of the loading space to the outside (during climb) or flow from the outside into the loading space (during landing) when a predetermined differential pressure between the environment and the loading space is exceeded. However, in the latter case, warm ambient air enters the loading space with the air flow, which has a significantly colder temperature than the surrounding environment, so that the temperature can drop to the dew point and water can condense from the air. The presence of condensate in the loading space is undesirable because it affects the transported cargo.

[0071] In order to avoid condensation in the interior of the container, it is preferably provided that at least one inner circumferential seal is arranged between the at least one inner door leaf and the opening of the container wall, and at least one outer circumferential seal is arranged between the at least one outer door leaf and the opening of the container wall, and a buffer space is arranged between the at least one inner door leaf and the at least one outer door leaf. This measure is based on the idea that the air entering from the environment due to pressure equalization is cooled before it enters the loading space of the container. For this purpose, a buffer space is created, which is formed between the outer circumferential seal and the inner circumferential seal, into which the ambient air flows before it enters the loading space (if necessary). The double-walled door structure consisting of an inner door leaf and an outer door leaf, together with the internal temperature of -60 to -80°C as described above, ensures that a temperature of approximately 0°C prevails on the outer side of the inner door leaf, so that the buffer space formed in the intermediate space between the inner door leaf and the outer door leaf is cooled. Due to the precooling of the ambient air in the buffer space, drying also occurs, wherein any condensation occurs along the flow path of the air upstream of the load space and in particular in the buffer space, but in any case not in the load space itself.

[0072] At the same time, it should be taken into account that in the case of dry ice, CO2 gas is produced during its consumption, which gas should escape from the loading space. Therefore, the inner seal and the outer seal preferably each include at least one sealing element, which can be displaced by the pressure difference and opens the gas channel from the inside to the outside when a predetermined pressure difference is exceeded.

[0073] The generation of CO2 gas in the load space can also compensate for the pressure balance during descent, where otherwise a gas flow from the outside into the load space (during descent) would occur. This further reduces the risk of air ingress (including moisture) compared to the use of non-sublimating coolants.

[0074] In this case, the inner circumferential seal can be designed in such a way that it allows the generated CO2 gas to escape, but at the same time largely prevents the inflow of warm ambient air. Together with the outer circumferential seal, a labyrinth is created here which, on the one hand, allows the CO2 gas to escape and, on the other hand, ensures that moisture from the incoming air condenses on the outer side of the at least one inner door leaf, which has a temperature of approximately 0° C. (between -20° C. and 8° C.). This prevents penetration of airborne moisture into the load space and the associated ice formation.

[0075] A preferred design of the thermal insulation provides that the at least one inner door leaf comprises an inner aluminum shell and an outer aluminum shell, and that a vacuum thermal insulation, preferably a vacuum insulation panel, is arranged between the inner aluminum shell and the outer aluminum shell to achieve thermal decoupling thereof. For example, a 30-50 mm thick vacuum insulation panel can be used. The inner aluminum shell and the outer aluminum shell can be held together by a connecting element made of a poorly thermally conductive, cold-resistant plastic (e.g. PEEK).

[0076] The outer door leaf may be insulated with a 60-80 mm thick multi-layered structure of honeycomb thermoformed PET film coated with aluminum on both sides.

[0077] The insulation of the outer door leaf can be further improved by inserting additional vacuum panels or partially replacing existing insulation with vacuum panels. This reduces the heat input through the outer door leaf and thus has a beneficial effect on the transit time of the container.

[0078] The container or container wall may have various geometric shapes, wherein a plurality of walls adjacent to each other at an angle are provided. Preferably, it is a cuboid container with six walls, the wall structure forming five of the walls and the door arrangement forming the sixth wall.

[0079] The container according to the invention is preferably designed as an air cargo container and therefore preferably has a size of at least 0.4 x 0.4 x 0.4 m, preferably 0.4 x 0.4 x 0.4 m. 3 Up to 1.6 x 1.6 x 1.6 m 3 , preferably 1.0x1.0x1.0 m 3 Up to 1.6 x 1.6 x 1.6 m 3 External dimensions.

[0080] Preferably, the first insulating layer of the container wall forms the outer surface of the container, so that no other layers or elements are attached to the outer wall. Alternatively, another insulating layer can be arranged on the outside of the first insulating layer, or a layer that protects the container from mechanical impacts and damages.

[0081] Dry ice is preferably used as coolant. However, other phase change materials are also possible. Common phase change materials based on kerosene or hydrated salts or other materials with high enthalpy are suitable as coolants. The target temperature that can be reached in the loading space of the container depends on the choice of coolant and is not limited to a specific temperature range within the scope of the invention. Thus, for example, the transport container can be operated not only in the range of -60 to -80°C, but also in the range of 25 to -15°C.

[0082] In order to be able to detect any damage to the container, it is preferably provided that at least one temperature sensor is arranged in the loading space and preferably at least one temperature sensor is arranged on each side of the container. Based on the measured values ​​of the at least one temperature sensor, the performance of the insulation can be continuously monitored. In addition, the sensor can be arranged to measure the ambient temperature, whereby the insulation performance of the container wall can be continuously calculated based on the temperature difference curve of the at least one temperature sensor arranged in the loading space and an external temperature sensor. The data can be continuously transmitted to a central database by wireless data transmission means, so that the functional efficiency of the container can be globally monitored and ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The present invention will now be described in more detail with reference to the accompanying drawings. Figure 1 shows a perspective view of a container according to the invention with the barrier element removed, Figure 2 Shows Figure 1 A cross section of a container with the door closed, Figure 3 Shows Figure 2 A detailed view of area A. Figure 4 Shows Figure 1 a container in which the barrier element is installed, and Figure 5 A detailed view of the fixing of the barrier element to the container is shown. DETAILED DESCRIPTION

[0084] Figure 1 1 shows a cuboid container 1, the container wall of which, except for the opening, surrounds the loading space on all sides. The container wall comprises two side walls, a rear wall, a bottom wall and a top wall.

[0085] The container wall consists of multi-layer insulation 2 and 3, inner double door 4, outer door 5, energy distribution layer 6 forming inner shell, drawer 7 with dry ice and drawer guide 8, all of which are attached to energy distribution layer 6 of the top wall.

[0086] As in accordance with Figure 2 As can be seen in the cross-sectional view of the , the insulation consists of an outer first insulation layer 2 and an inner second insulation layer 3. The first insulation layer has a thickness of, for example, 60-80 mm and consists of a multilayer structure of a honeycomb deep-drawn PET film coated with aluminum on both sides. This achieves an insulation performance of the first insulation layer of 4 to 300 mW / (mK). The second insulation layer 3 has a thickness of 30-50 mm and consists of a high-performance insulation member (such as a vacuum insulation panel (VIP) or aerogel), thus achieving an insulation performance of 1 to 30 mW / (mK).

[0087] In the region of the container front opening, the inner double door 4 can be assigned to the inner second insulating layer 3 and the outer door 5 to the outer first insulating layer 2. Figure 3As shown in , the inner double door 4 is composed of an inner aluminum half shell 13 and an outer aluminum half shell 14, respectively, wherein the inner shell and the outer shell are thermally decoupled. Decoupling is achieved by using an inner insulation 3 made of a 30-50 mm thick high-performance insulation (such as a vacuum panel) and a connecting element made of a low thermal conductivity, cold-resistant plastic 12 (e.g., PEEK). The outer door 5 is insulated by a 60-80 mm thick multi-layered structure of a honeycomb deep-drawn PET film coated with aluminum on both sides. The combination of the high insulation performance (1 to 30 mW / (mK)) of the inner double door 4 and the medium insulation performance (4 to 300 mW / (mK)) of the outer door 5 results in a temperature of about 0°C (between -20°C and 8°C) on the outer side of the inner double door 4 at an internal temperature of -60°C to -80°C. This makes it possible to manually open the inner double door 4 during operation (without the risk of cold burns).

[0088] On the edge of the inner door 4 there is a seal 11 which allows the generated CO2 gas to escape but at the same time largely prevents warm ambient air from flowing in. The seal 10 is also located on the outer door so that together with the inner door seal 11 a labyrinth is created which on the one hand allows the generated CO2 gas to escape and on the other hand ensures that moisture from the incoming air condenses on the outside of the inner double door 4, which has a temperature of approximately 0°C (between -20°C and 8°C). This prevents moisture in the air from penetrating into the interior and the associated ice formation.

[0089] The energy distribution layer 6 consists, for example, of aluminum plates 0.5-5 mm thick. These aluminum plates have a thermal conductivity of about 150 W / (mK), thereby distributing the local heat input across the inner shell and resulting in a uniform temperature distribution in the load space. The joints of the individual aluminum panels at the sides and corners are reinforced with rivets so that they can withstand the forces generated by thermal stress.

[0090] The drawer 7 and the drawer guide 8 attached to the top of the inner shell 6 are also made of 0.5-5 mm thick aluminum plates having a thermal conductivity of 150 W / (mK). Dry ice 9 is introduced directly into the drawer.

[0091] Figure 4 The container 1 is shown with a plate-shaped barrier element 15 installed in order to minimize heat exchange between the loading space and the environment when the inner door 4 and the outer door 5 are open. As can be seen, the barrier element 15 covers substantially the entire area of ​​the opening through which air can be exchanged between the loading space and the environment, but leaves the drawer 7 unhindered. A handle 16 is arranged to facilitate manipulation of the barrier element 15.

[0092] like Figure 5As shown in , the barrier element 15 can be fixed to the container by means of a hook 18, which engages with a support element 17 arranged on the drawer guide 8 or the wall of the container. The hook 18 is arranged on each of the two lateral sides of the barrier element 15.

Claims

1. A container (1) for transporting temperature-sensitive goods, the container comprising a wall structure surrounding a loading space for receiving the goods and comprising an opening for loading and unloading the loading space, the container further comprising door means (4, 5) for selectively opening and closing the opening, wherein: At least one coolant reservoir (7) for containing coolant is arranged and / or fastened in the loading space, on at least one wall of the wall structure, in particular on the upper wall, wherein the at least one coolant reservoir (7) or the coolant contained therein can be exchanged via the coolant access part of the opening, characterized in that a blocking element (15) is arranged in the remaining part of the opening to separate the loading space from the outside when the door device (4, 5) is in the open position.

2. The container according to claim 1, characterized in that The barrier element (15) is substantially impermeable to ambient air.

3. The container according to claim 1 or 2, characterized in that: The barrier element (15) is made of a sheet of material such as metal, wood, fabric, plastic or a combination thereof.

4. The container according to claim 1, 2 or 3, characterized in that: The barrier element (15) covers at least 50%, preferably at least 80%, more preferably at least 90% of the air exchange flow cross-sectional area between the loading space and the outside.

5. The container according to claim 4, characterized in that The air exchange flow profile area is defined as a rectangular area enclosed by three walls of the wall structure and a coolant reservoir (7) arranged on a fourth wall, preferably the upper wall.

6. The container according to any one of claims 1 to 5, characterized in that The distance between the barrier element (15) and the bottom wall of the wall structure is less than 50 mm, preferably less than 30 mm.

7. The container according to any one of claims 1 to 6, characterized in that The barrier element (15) is arranged to cover at least 70%, preferably at least 90%, more preferably at least 98% of the width of the opening.

8. The container according to any one of claims 1 to 7, characterized in that The barrier element (15) comprises an elastic sealing element on at least one of its lateral edges.

9. The container according to any one of claims 1 to 8, characterized in that The at least one coolant reservoir (7) is a drawer (7) which is guided in a guide element (8) such that it can be pulled out and brought into the loading space.

10. The container according to any one of claims 1 to 9, characterized in that The barrier element (15) is removably fixed to the wall structure and / or to the guide element (8) of the drawer (7).

11. The container according to any one of claims 1 to 9, characterized in that The blocking element (15) is pivotably mounted to a wall of the wall structure and / or to a guide element (8) of the drawer (7).

12. The container according to any one of claims 1 to 11, characterized in that The wall structure and / or the door arrangement (4, 5) are designed as a layered structure, which comprises, from the outside to the inside, a first insulating layer (2), optionally a second insulating layer (3), and an energy distribution layer (6) which delimits the loading space and is made of a material with a thermal conductivity of >100 W / (mK).

13. The container according to any one of claims 1 to 11, characterized in that The door arrangement (4, 5) comprises at least one inner door leaf (4) and at least one outer door leaf (5).

14. The container according to any one of claims 1 to 13, characterized in that Dry ice is arranged in the at least one coolant reservoir (7).

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