TRANSPORT CONTAINER

Description

[0001] The invention relates to a transport container for transporting temperature-sensitive goods, comprising a container wall surrounding an interior space for receiving the goods, with a plurality of walls adjoining each other at an angle, wherein the container wall has an opening for loading and unloading the interior space, which can be closed by means of a door device, and wherein the container wall encloses the interior space on all sides except for the opening.

[0002] A transport container is known, for example, from EP 3 128 266 A.

[0003] When transporting temperature-sensitive goods, such as pharmaceuticals, over periods of several days, specific temperature ranges must be maintained during storage and transport to ensure the usability and safety of the goods. For various pharmaceuticals and vaccines, temperature ranges of -60°C to -80°C are prescribed as storage and transport conditions.

[0004] To ensure that the desired temperature range of the transported goods is maintained consistently and verifiably during transport, shipping containers, such as air freight containers, with special insulation properties are used. The technical implementation of shipping containers for temperatures ranging from -60°C to -80°C typically involves insulated containers combined with a refrigerant. Insulation is achieved through layered wall constructions made of standard insulation materials such as EPS, PIR, or XPS, as well as high-performance insulation such as vacuum insulation panels (VIPs).

[0005] Dry ice (solid CO₂) is used as the coolant, which, due to its sublimation temperature of approximately -78.5°C, is ideally suited for this temperature range. Furthermore, the phase transition from solid to gaseous (sublimation) requires an energy of 571.1 kJ / kg, which, compared to commercially available phase change materials in a similar temperature range (≈200 kJ / kg), enables a very high cooling effect at a low weight. Another advantage of dry ice is its residue-free dissolution. Only the safe removal of the gaseous carbon dioxide, which occupies approximately 760 times the volume of the dry ice at normal pressure and a temperature of 0°C, needs to be ensured. For air transport, there are usually maximum sublimation rates or quantities of dry ice per flight that must not be exceeded.Minimizing the amount of dry ice used per kg of cargo therefore directly affects the total amount of cargo allowed per flight.

[0006] There are different approaches to positioning dry ice inside the transport container. One method involves placing the dry ice on top of or inside the transported goods. The advantage of this approach is that the temperature of the goods remains very constant at approximately -78°C. A disadvantage is that a large quantity of dry ice is required to achieve even coverage of the transported goods and to fill any gaps. Another disadvantage is that the amount of dry ice needed depends on the transported goods and their packaging. Furthermore, the operating time of the transport container is limited by local temperature variations when heat input is asymmetrical. The remaining dry ice effectively goes unused.

[0007] In another method, dry ice in disc form is placed around the goods on all sides, as well as on the top and bottom of the transport container. The advantage here, too, is the even temperature distribution. However, if there is an asymmetrical heat input (e.g., from sunlight from above), the operating time of the entire transport container is limited by the point where the dry ice sublimates completely first. On the sides with less heat input, some of the dry ice remains unused. To still achieve the desired operating time, a large quantity of dry ice is required, although only a certain proportion is actually needed. Furthermore, manually inserting the dry ice on all sides, as well as on the top and bottom of the transport container before each transport is laborious.Furthermore, it is not easily possible to extend the service life of the transport container by renewing the dry ice, as this requires completely disassembling the container.

[0008] Another problem with using dry ice is that the inner walls of the transport container are usually made of plastic or cardboard, meaning that heat distribution within the container occurs only through the goods themselves and via natural convection. The heat flow through the goods is determined by the average thermal conductivity of the product and its packaging and cannot be guaranteed. Therefore, the goods must be kept a certain distance from the side walls, the back wall, and the bottom to ensure unimpeded air circulation and allow for a uniform temperature distribution through natural convection. This has the disadvantage that not the entire interior space can be used for the goods.

[0009] The present invention aims to provide a transport container for the temperature range of -60°C to -80°C, which has the following properties. The dry ice used should be utilized as efficiently as possible. This means that at the end of the operating time, which is defined by the point at which the temperature first deviates above -60°C inside the container, as large a proportion of the dry ice as possible should have sublimated. Due to the limitations on the permissible amount of dry ice in air transport, this is crucial for the total possible quantity of cargo per flight.

[0010] Furthermore, it should be possible to utilize the entire interior of the transport container for the transported goods. No gaps or ducts for air circulation should be required. Introducing the dry ice into the transport container before transport should be as simple as possible. After transport, it should also be possible to extend the operating time by replenishing the dry ice, without having to disassemble the transport container or remove the transported goods.

[0011] The structure and materials used should withstand low temperatures, be able to absorb the mechanical forces caused by thermal stresses and loads during transport, and at the same time be as light as possible.

[0012] To solve this problem, the invention essentially provides for a transport container of the type mentioned at the outset that the container wall consists of a layered structure comprising, from the outside in: a first insulating layer, optionally a second insulating layer and an energy distribution layer bounding the interior made of a material with a thermal conductivity of > 100 W / (mK), and that at least one coolant container for receiving a coolant is arranged and / or attached in the interior on at least one wall, in particular an upper wall.

[0013] By combining a coolant container, such as dry ice, located and / or attached to at least one wall inside the container, with an energy distribution layer that defines the interior, efficient heat distribution across the entire inner shell is achieved, thus minimizing the amount of coolant required. Due to this heat distribution, it is sufficient to position the coolant on only one wall. However, it is also conceivable to position the coolant on two or more walls. The highly thermally conductive inner shell enables very efficient use of the dry ice, whereby heat input from any position within the transport container is transferred to the coolant and absorbed there, thus compensating for asymmetrical heat input and preventing one-sided sublimation of the dry ice.The amount of coolant can be chosen in such a way that the coolant is almost completely used up at the end of the operating time.

[0014] The at least one coolant reservoir or its holder is in direct thermal contact with the energy distribution layer, the thermally conductive connection preferably having a thermal conductivity of > 100 W / (mK).

[0015] The energy distribution layer that defines the interior space is preferably in direct contact with the interior space, so that direct heat transfer between the interior space and the energy distribution layer is ensured.

[0016] Since no convection is required for heat distribution throughout the entire interior volume, the interior can be used entirely for the payload. No air gaps or ducts are needed to maintain air circulation.

[0017] The highly efficient use of dry ice through internal heat distribution, combined with double-layer insulation of the container wall, results in a service life of more than 100-140 hours at an average ambient temperature of 30°C, using 80-120 kg of dry ice and a payload volume of 1 to 1.5 m³ with an external volume of 2-4 m³. This represents a significant improvement of 2 to 20 times compared to conventional solutions. This allows for a payload volume of 1 to 1.5 m³ per RKN aircraft position, or for four transport containers to be arranged on a PMC pallet with a total payload volume of 4 x 1.5 m³ or 6 m³.

[0018] Regarding the layer structure of the container wall, it is preferably provided that the first insulation layer, the second insulation layer if present, and the energy distribution layer lie directly on top of each other.

[0019] Preferably, the first insulating layer, any second insulating layer, and the energy distribution layer completely and without interruption enclose the interior space, except for the opening. The energy distribution layer completely surrounds the interior space, except for the opening; that is, each wall of the container wall comprises the energy distribution layer as its innermost layer. The energy distribution layers of all walls are thermally connected to each other at the adjacent edges and corners, i.e., by means of a connection having a thermal conductivity of > 100 W / (mK).

[0020] Preferably, the door device also consists of the same layered structure as the container wall. In particular, the door device consists of a layered structure comprising, from the outside in: a first insulating layer, optionally a second insulating layer, and an energy distribution layer bounding the interior, made of a material with a thermal conductivity of > 100 W / (mK).

[0021] For adequate heat distribution, a thermal conductivity of at least 100 W / (mK) is specified for the energy distribution layer. The higher the thermal conductivity of the energy distribution layer, the more efficient the utilization of the coolant. According to a preferred embodiment, the thermal conductivity of the energy distribution layer of the tank wall and / or the door assembly can be at least 140 W / (mK), preferably at least 180 W / (mK). The energy distribution layer of the tank wall and / or the door assembly can be made, for example, of aluminum, graphite, or a graphite composite material, in particular graphite plates coated on both sides with carbon fiber-reinforced plastic. Such materials also provide mechanical reinforcement of the tank wall at a low weight.

[0022] In the case of aluminum, 0.5-5 mm thick aluminum plates can be used, which have a thermal conductivity of approximately 150 W / (mK). This distributes localized heat input across the inner shell, resulting in a uniform temperature distribution inside. The joints between the individual aluminum plates at the sides and corners can be reinforced with rivets to withstand the forces caused by thermal stresses.

[0023] In the case of a carbon-graphite composite energy distribution layer, for example, the composite panels can consist of a 0.2–1 mm thick graphite core laminated on both sides with 0.2–2 mm thick carbon fiber reinforced polymer (CFRP) sheets. Since graphite exhibits thermal conductivities of up to 400 W / (mK) depending on its density, carbon-graphite composite panels can achieve similar or higher average thermal conductivities than comparable aluminum panels. Furthermore, CFRP has a better strength-to-weight ratio than aluminum, resulting in weight savings. Another advantage of carbon-graphite composite panels is the low coefficient of thermal expansion of CFRP. Typical values ​​in the fiber direction are αCFRP = 0.6 × 10⁻⁶ < K⁻¹ < . For comparison, the coefficient of thermal expansion of a common aluminum alloy: α EN-AW 5754 = 23.8·10 -6< K -1< .This reduces thermal stresses and the resulting mechanical loads on the inner shell.

[0024] In a particularly preferred embodiment, the at least one coolant reservoir is designed as a drawer, which is guided in a drawer slide so that it can be extended and retracted from and into the interior. Such a design allows for extremely simple handling, enabling the coolant to be filled or replenished without disassembling the transport container or removing the transported goods. The operating time of the transport container can be extended as desired by refilling the coolant.

[0025] Preferably, the drawer(s) have dimensions such that the entire surface of one wall of the container wall is covered.

[0026] Preferably, the at least one coolant reservoir, in particular the drawer(s) and the drawer guide, which is attached to at least one wall, is also made of a highly thermally conductive material, so that the introduced heat is distributed evenly throughout the coolant. It is preferably provided that the at least one coolant reservoir is made of a material with a thermal conductivity of > 100 W / (mK), preferably > 140 W / (mK), in particular > 180 W / (mK), for example, aluminum, graphite, or a graphite composite material, in particular graphite plates coated on both sides with carbon fiber reinforced plastic.

[0027] The thermal insulation of the transport container is achieved by a first and, optionally, a second insulating layer. The construction of the container wall with at least two insulating layers allows each insulating layer to be optimized with regard to its respective insulating function. Preferably, one of the insulating layers, in particular the first, outer insulating layer, is designed to minimize heat transfer into the interior via thermal radiation. The other insulating layer, in particular the second, inner insulating layer, can be designed to minimize heat transfer into the interior via solid-state conduction.

[0028] Preferably, the first insulating layer can have a thermal conductivity of 4 to 300 mW / (mK) and the second insulating layer a thermal conductivity of 1 to 30 mW / (mK), wherein the first insulating layer preferably has a higher thermal conductivity than the second insulating layer.

[0029] This can result in a U-value for the transport container of 0.1-0.2 W / m² < K, which corresponds to a very low heat input compared to standard transport containers.

[0030] With regard to the design of one of the insulating layers, preferably the first insulating layer, as a barrier against thermal radiation, this layer can have a heat-reflecting coated substrate material, such as a substrate material provided with a metal coating. Preferably, the heat-reflecting coating is a metallic, in particular gas-tight, coating, preferably a coating with an emissivity of < 0.5, preferably < 0.2, and particularly preferably < 0.04, such as an aluminum coating. It is preferably provided that the aforementioned insulating layer comprises a multi-layered structure of honeycomb-shaped deep-drawn plastic films, which is provided on both sides with a heat-reflecting coating, in particular of aluminum.An advantageous design is achieved when the insulation layer in question comprises a plurality of, in particular honeycomb-shaped, hollow chambers, with a honeycomb structure element according to WO 2011 / 032299 A1 being particularly advantageous. Alternatively, the insulation layer in question can consist of a conventional porous insulating material, such as polyurethane, polyisocyanurate, or expanded polystyrene. The insulation layer in question preferably has a thickness of 60–80 mm.

[0031] With regard to the design of the other insulating layer, preferably the second insulating layer, as a barrier against solid-state heat conduction, this can preferably be designed as vacuum thermal insulation and preferably comprise or consist of vacuum insulation panels.

[0032] The second insulation layer preferably has a thickness of 30-50 mm.

[0033] Preferably, the vacuum insulation panels have a porous core material as a support structure for the internal vacuum and a gas-tight shell surrounding the core material, wherein the core material preferably consists of an aerogel, open-cell polyurethane, or open-cell polyisocyanurate. The advantage of these core materials over conventional pyrogenic silica lies in their lower density, which results in weight savings compared to conventional vacuum panels. The density of aerogel, for example, is in the range of 80–140 kg / m³, while pyrogenic silica typically has a density of 160–240 kg / m³. This is with similar thermal conductivity properties in the range of 2–6 mW / (mK).

[0034] Alternatively, the aforementioned insulation layer can comprise an outer wall, a spaced-apart inner wall, and a vacuum chamber formed between the outer and inner walls, the vacuum chamber being a continuous vacuum chamber that surrounds the interior on all sides except for the opening. This insulation layer of the container wall is thus designed as a double-walled vacuum container that surrounds the interior on all sides except for the container opening. In contrast to the use of conventional vacuum panels, the insulation therefore does not consist of individual vacuum elements that must be assembled into a shell, but rather encompasses all sides of the transport container in one piece, except for the opening.Because a continuous vacuum chamber is formed between the inner and outer walls of the insulation layer, completely surrounding the interior except for the opening, connection points between the otherwise necessary separate vacuum panels and the associated thermal bridges can be avoided. The double-walled design of the insulation layer is also self-supporting, giving it a stabilizing function in addition to its insulating properties. This eliminates the need for load-bearing structural components.

[0035] The term "vacuum chamber" means that the space between the inner and outer walls of the insulation layer is evacuated in order to achieve thermal insulation by reducing or preventing heat conduction through the gas molecules. Preferably, the air pressure in the vacuum chamber is 0.001–0.1 mbar.

[0036] Preferably, the outer and inner walls are made of a metal sheet, in particular stainless steel, aluminum, or titanium, and preferably have a thickness of 0.01 to 1 mm. This ensures both the necessary stability and a gas-tight seal. In such a design, the inner wall of the insulation layer, if arranged as the second insulation layer, can simultaneously form the energy distribution layer.

[0037] To withstand the pressure forces of the surrounding air without requiring excessively thick outer and inner walls, the outer and inner walls are preferably connected by a plurality of spacers, preferably made of a plastic with a thermal conductivity of < 0.35 W / (m·K), such as polyetheretherketone or aramid. The spacers ensure the desired distance between the outer and inner walls, thus preserving the intervening cavity, i.e., the vacuum chamber. Since the spacers create thermal bridges, it is advantageous to make them from a material with the lowest possible thermal conductivity.

[0038] To further increase the thermal insulation performance of the insulating layer, a preferred embodiment provides that a plurality of spaced-apart insulating films are arranged one above the other in the vacuum chamber, the plane of which runs essentially parallel to the plane of the outer and inner walls. In particular, the insulating films are stacked, with a stack of films preferably arranged in each wall of the container wall, extending substantially over the entire wall. Preferably, the insulating films are arranged such that they surround the interior on all sides except for the opening.

[0039] Preferably, the insulating films are arranged such that a gap (protective space) remains between the inner surface of the outer or inner wall facing the vacuum chamber and the film stack, so that the film stack is not compressed by any deformation of the walls. Furthermore, the gap provides space for structural stabilization of the spacers and facilitates vacuum sealing.

[0040] Another preferred embodiment provides that the insulating films are held apart from each other by planar spacer elements, wherein the planar spacer elements are preferably formed from a textile surface structure, in particular as a polyester fleece.

[0041] In particular, the insulating films can be designed as metal-coated or metal-vapor-deposited plastic films. Such insulating films are also referred to as superinsulating films. The metal coating consists, for example, of aluminum.

[0042] The overall performance of the transport container's insulation naturally also depends on the thermal insulation properties of the door mechanism that closes the opening to the interior. As already mentioned, the door mechanism can consist of a layered structure that corresponds to the layered structure of the container wall and comprises, from the outside in, a first insulating layer, a second insulating layer, and an energy distribution layer bordering the interior, made of a material with a thermal conductivity of > 100 W / (mK).

[0043] The door assembly comprises at least one inner door leaf and at least one outer door leaf. In particular, the door leaves are hinged doors attached to the transport container by means of a hinge. The design with at least one outer and at least one inner door leaf results in a two-layer construction, in which the at least one outer door leaf preferably forms the first insulating layer of the door assembly and the at least one inner door leaf forms the second insulating layer of the door assembly. Regarding the properties and construction of the first and second insulating layers, reference is made to the functions and properties described above in connection with the insulating layers of the container wall.

[0044] The at least one outer door leaf and the at least one inner door leaf can be opened and closed separately and independently of each other. The double-walled construction of the door assembly results in a temperature of around 0°C (between -20°C and 8°C) on the outside of the at least one inner door leaf when the interior temperature is between -60°C and -80°C. This makes it possible to open the inner door leaf manually during operation (i.e., without risk of frostbite). This effect is preferably achieved by the at least one inner door leaf having a higher thermal conductivity (1 to 30 mW / (mK)) than the at least one outer door leaf (4 to 300 mW / (mK)).

[0045] A preferred design provides that the door device comprises a single outer door leaf and two inner door leaves to form an inner double door.

[0046] The design of the door assembly, consisting of at least one outer and at least one inner door leaf, further allows the coolant to be replenished, i.e., refilled into the coolant reservoir, while the at least one inner door leaf is closed. For this purpose, the at least one inner door leaf is arranged to allow access to the coolant reservoir through the open outer door leaf when the at least one inner door leaf is closed.

[0047] In this design, the inner door leaf or double door can be made smaller, allowing the coolant reservoir(s) to be accessed even when the inner door is closed. If the coolant reservoir is designed as a drawer, it can be pulled out of its mounting even when the inner door is closed. This has the advantage of extending the operating time of the transport container indefinitely by replenishing the coolant. This is achieved without opening the inner double door or removing the transported goods.

[0048] From a design perspective, the at least one coolant reservoir can be made accessible when the inner door leaf is closed by providing the coolant reservoir with an access section located in the opening of the reservoir wall, and by ensuring that the at least one inner door leaf, when closed, interacts with the access section on the side facing it to seal the interior. The design can be such, for example, that the inner door leaf is essentially flush with the front face of the access section. The access section is defined here as the section or side of the coolant reservoir through which the reservoir must be accessible for refilling the coolant. In the case of a drawer, for example, this is the drawer front that is gripped to pull the drawer out of the interior of the transport container.

[0049] To ensure optimal thermal insulation in the access section, it is preferably provided that the coolant tank has vacuum thermal insulation on the front side facing the opening of the tank wall.

[0050] When transporting containers by air freight, they must allow for pressure equalization between the container's interior and the aircraft's pressurized cabin, especially since the cabin pressure in the passenger cabin and cargo hold is set lower than the ambient air pressure during takeoff and landing. For pressure equalization, containers are typically equipped with a valve or a door seal that allows air to flow out of the container (during ascent) or into the container (during descent) when a predetermined pressure differential between the environment and the container is exceeded. In the latter case, however, warm ambient air enters the container, which is significantly colder than the surrounding air, potentially causing the dew point to be reached and water from the air to condense.The presence of condensate in the container chamber is undesirable because it impairs the transported goods.

[0051] To prevent condensation inside the transport container, it is preferably provided that at least one inner circumferential seal is located between the at least one inner door leaf and the opening in the container wall, and at least one outer circumferential seal is located between the at least one outer door leaf and the opening in the container wall. Furthermore, 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 of ​​cooling the air entering from the environment due to pressure equalization before it reaches the interior of the transport container. For this purpose, a buffer space is created between the outer and inner circumferential seals, into which the ambient air flows before potentially entering the interior.The double-walled door construction, consisting of an inner and outer door leaf, combined with the interior temperature of -60 to -80°C as described above, ensures that the exterior of the inner door leaf maintains a temperature of approximately 0°C, thus cooling the buffer zone formed in the space between the outer and inner door leaves. Due to the pre-cooling of the ambient air in the buffer zone, drying also occurs, with any condensation forming along the airflow path upstream of the interior, and particularly within the buffer zone, but certainly not within the interior itself.

[0052] At the same time, it must be taken into account that in the case of dry ice, CO₂ gas is produced during its consumption, which should escape from the interior. Therefore, the inner and outer seals preferably each comprise at least one sealing element that can be displaced by pressure differential and which opens a gas passage from the inside to the outside when a predetermined pressure differential is exceeded.

[0053] The formation of CO₂ gas inside the aircraft can also compensate for pressure equalization during descent, which would otherwise result in an airflow from outside into the container chamber. This further reduces the risk of air ingress, including humidity, compared to using a non-sublimating refrigerant.

[0054] The inner perimeter seal can be designed to allow the CO₂ gas produced to escape, while largely preventing the inflow of warm ambient air. Together with the outer perimeter seal, this creates a labyrinth that, on the one hand, allows the CO₂ gas to escape, and on the other hand, ensures that the moisture from the incoming air condenses on the outside of at least one inner door leaf, which has a temperature of around 0°C (between -20°C and 8°C). This prevents humidity from penetrating the interior and the associated ice formation.

[0055] A preferred embodiment 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 vacuum insulation, preferably vacuum insulation panels, is arranged between the inner and outer aluminum shells for thermal decoupling. For example, 30-50 mm thick vacuum insulation panels can be used. The inner and outer aluminum shells can be held together with connecting elements made of low thermal conductivity, cold-resistant plastic (e.g., PEEK).

[0056] The outer door leaf can be insulated with a 60-80 mm thick, multi-layered structure made of honeycomb-shaped deep-drawn PET films, coated on both sides with aluminium.

[0057] The insulation of the outer door leaf can be further improved by adding additional vacuum panels or partially replacing the existing insulation with vacuum panels. This reduces heat gain through the outer door leaf and therefore has a beneficial effect on the service life of the transport container.

[0058] The transport container or container wall can be designed in various geometric shapes, in which a plurality of walls adjoining each other at an angle are provided. Preferably, it is a cuboid transport container having six walls, of which the container wall forms five walls and the door device the sixth wall.

[0059] The transport container according to the invention is preferably designed as an air freight container and therefore preferably has external dimensions of at least 0.4x0.4x0.4 m, preferably 0.4x0.4x0.4 m to 1.6x1.6x1.6 m, preferably 1.0x1.0x1.0 m to 1.6x1.6x1.6 m.

[0060] The first insulating layer of the container wall preferably forms the outer surface of the transport container, so that no further layers or elements are attached to the outer wall. Alternatively, a further thermal insulation layer or a layer that protects the transport container from mechanical impacts and damage can be arranged on the outside of the first insulating layer.

[0061] Dry ice is preferably used as the coolant. However, other phase change materials are also possible. Suitable coolants include common paraffin- or salt hydrate-based phase change materials or other materials with high enthalpy. The target temperature achievable inside the transport container depends on the choice of coolant and is not limited to specific temperature ranges within the scope of the present invention. Therefore, the transport container can be operated not only in a range of -60 to -80°C, but also, for example, in a range of -25 to -15°C.

[0062] To detect any damage to the transport container, it is preferably provided that at least one temperature sensor is arranged inside, preferably at least one on each side of the container. Based on the readings from the at least one temperature sensor, the performance of the insulation can be continuously monitored. Additionally, a sensor can be installed to measure the ambient temperature, and the insulation performance of the container wall can be continuously calculated from the temperature difference between the at least one internal temperature sensor and the external temperature sensor. This data can be continuously transmitted wirelessly to a central database, enabling global monitoring and assurance of the transport container's functionality.

[0063] The invention is explained in more detail below with reference to examples schematically illustrated in the drawing. In this drawing, we show... Fig. 1 a perspective view of a cuboid transport container according to an unclaimed example, Fig. 2 a longitudinal section of the transport container according to Fig. 1 with closed doors and filled coolant drawers, Fig. 3 a detailed view in area A of the Fig. 2 the door device of a first, unclaimed embodiment variant, Fig. 4 a detailed view in the area of ​​the door device of an embodiment according to the invention, Fig. 5 a front view in partial section of the embodiment according to the invention and Fig. 6 A detailed view of a coolant drawer.

[0064] In Fig. 1 Figure 1 shows a cuboid transport container whose container wall completely encloses an interior space except for an opening. The container wall comprises two side walls, a back wall, a bottom, and a top.

[0065] The container wall consists of a multi-layer insulation 2 and 3, an inner double door 4, an outer door 5, an energy distribution layer 6 forming the inner shell, drawers 7 with dry ice and a drawer guide 8, which are attached to the energy distribution layer 6 of the ceiling.

[0066] As shown in the section view according to Fig. 2 As can be seen, the insulation consists of an outer, first insulation layer 2 and an inner, second insulation layer 3. The first insulation layer is, for example, 60-80 mm thick and consists of a multi-layered structure made of deep-drawn, honeycomb-patterned PET films coated on both sides with aluminum. This achieves a thermal transmittance (TWR) of 4 to 300 mW / (mK) for the first insulation layer. The second insulation layer 3 is 30-50 mm thick and consists of high-performance insulation, such as vacuum insulation panels (VIPs) or aerogel, achieving a TWR of 1 to 30 mW / (mK).

[0067] In the area of ​​the front opening of the transport container, the inner double door 4 can be assigned to the inner, second insulation layer 3 and the outer door 5 to the outer, first insulation layer 2. As in Fig. 3 As shown, the inner double door 4 consists of an inner 13 and an outer aluminum half-shell 14, with the inner and outer shells being thermally decoupled. This decoupling is achieved with internal insulation 3 made of 30-50 mm thick high-performance insulation, such as vacuum panels, and connecting elements made of low-thermal-conductivity, cold-resistant plastic 12 (e.g., PEEK). The outer door 5 is insulated with a 60-80 mm thick, multi-layered structure made of honeycomb-patterned, deep-drawn PET film, coated on both sides with aluminum. Due to the combination of the high thermal conductivity of the inner double door 4 (1 to 30 mW / (mK)) and the medium thermal conductivity of the outer door 5 (4 to 300 mW / (mK)), a temperature of around 0°C (between -20°C and 8°C) is maintained on the outside of the inner double door 4 when the interior temperature is -60°C to -80°C. This makes it possible to open the inner double door 4 manually during operation (without risk of cold burns).

[0068] A seal 11 is located at the edge of the inner door 4, allowing the CO₂ gas produced to escape while largely preventing warm ambient air from entering. Seals 10 are also located on the outer door, forming a labyrinth together with the inner door seal 11. This labyrinth allows the CO₂ gas produced to escape and, at the same time, causes the moisture from the incoming air to condense on the outside of the inner double door 4, which has a temperature of around 0°C (between -20°C and 8°C). This prevents humidity from penetrating the interior and thus prevents ice formation.

[0069] The energy distribution layer 6 consists, for example, of 0.5–5 mm thick aluminum plates. These have a thermal conductivity of approximately 150 W / (mK), which distributes local heat inputs across the inner shell, resulting in a uniform temperature distribution inside. The connections between the individual aluminum plates at the sides and corners are reinforced with rivets so that they can withstand the forces caused by thermal stresses.

[0070] The drawers 7 and the drawer guides 8, which are attached to the top of the inner shell 6, also consist of 0.5-5 mm thick aluminum plates with a thermal conductivity of 150 W / (mK). The dry ice 9 is placed directly into the drawers.

[0071] In Fig. 4 and 5 A modified version is shown, in which Fig. 5The left half shows a front view of the transport container with the inner double door 4 closed and the outer door 5 open, while the right half shows a cross-section through the transport container with drawers. In the modified version shown here, the inner double door 4 is made smaller, so that the drawers 7 can be opened even when the inner double door 4 is closed. Additionally, the outside of the dry ice drawers 7 is insulated by 30-50 mm thick vacuum panels 17. This has the advantage that the operating time of the transport container can be extended indefinitely by replenishing the dry ice. The inner double door does not need to be opened, and the transported goods do not need to be removed.

[0072] Furthermore, in this variant, the insulation of the outer door 5 is improved by inserting additional vacuum panels 16 or partially replacing the existing insulation 15 with vacuum panels. This reduces heat input through the front door and therefore has a beneficial effect on the service life of the transport container.

Claims

1. Transport container for transporting temperature-sensitive goods to be transported, having a container wall arrangement surrounding an interior chamber for receiving the goods to be transported, container wall arrangement comprising a plurality of walls adjoining one another at an angle, the container wall arrangement having an opening for loading and unloading the interior chamber, and having a door device by means of which the opening can be closed, and the container wall arrangement enclosing the interior chamber on all sides with the exception of the opening, the container wall arrangement consisting of a layered structure comprising, from the outside to the inside a first insulation layer (2), optionally a second insulation layer (3) and an energy distribution layer (6) bounding the interior chamber and made of a material with a thermal conductivity of > 100 W / (m.K), and in that at least one coolant reservoir (7) for receiving a coolant is arranged and / or fastened in the interior chamber on at least one wall, in particular an upper wall, characterized in that the door device comprises at least one inner door panel (4) and at least one outer door panel (5), and in that the at least one inner door panel (4) is arranged to keep the coolant reservoir (7) accessible via the opened outer door panel (5) in the closed state of the at least one inner door panel (4), wherein the at least one coolant reservoir or its support is directly in heat-conducting connection with the energy distribution layer, the heat-conducting connection preferably having a thermal conductivity of > 100 W / (m.K).

2. Transport container according to claim 1, characterized in that the door device consists of a layered structure comprising from the outside to the inside: a first insulation layer (2), optionally a second insulation layer (3), and an energy distribution layer (6) bounding the interior chamber and made of a material having a thermal conductivity of > 100 W / (m.K).

3. Transport container according to claim 1 or 2, characterized in that the at least one coolant reservoir (7) is designed as a drawer which is guided in a drawer guide (8) so as to be extractable from the interior chamber and inssertable into the interior chamber.

4. Transport container according to claim 1, 2 or 3, characterized in that the first insulation layer (2) has a thermal conductivity of 4 to 300 mW / (m.K) and the second insulation layer (3) has a thermal conductivity of 1 to 30 mW / (m.K), the first insulation layer (2) preferably having a higher thermal conductivity than the second insulation layer (3).

5. Transport container according to any one of claims 1 to 4, characterized in that the first or the second insulation layer (2,3) comprises a multilayer structure of honeycomb-shaped deep-drawn plastic foils, which is provided on both sides with a heat-reflecting coating, in particular of aluminum, or consists of a porous insulating material, such as polyurethane, polyisocyanurate or expanded polystyrene.

6. Transport container according to any one of claims 1 to 5, characterized in that the first or the second insulation layer (3) is designed as vacuum thermal insulation and preferably has vacuum insulation panels or consists of these.

7. The transport container according to claim 6, characterized in that the vacuum insulation panels comprise a porous core material as a support body for the vacuum present in the interior and a gas-tight envelope surrounding the core material, the core material preferably consisting of an aerogel, open-pored polyurethane or open-pored polyisocyanurate.

8. Transport container according to any one of claims 1 to 6, characterized in that the first or the second insulation layer (2,3) has an outer wall, an inner wall spaced therefrom and a vacuum chamber formed between the outer and inner walls, the vacuum chamber being designed as a continuous vacuum chamber surrounding the interior chamber on all sides with the exception of the opening.

9. Transport container according to claim 8, characterized in that the outer wall and the inner wall are 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.

10. Transport container according to claim 8 or 9, characterized in that the inner wall forms the energy distribution layer (6).

11. Transport container according to any one of claims 1 to 10, characterized in that the energy distribution layer (6) consists of aluminum, of graphite or of a graphite composite material, in particular of graphite sheets coated on both sides with carbon-fiber-reinforced plastic.

12. Transport container according to any one of claims 1 to 11, characterized in that the at least one coolant reservoir (7) consists of a material with a thermal conductivity of > 100 W / (m.K), preferably of aluminum, of graphite or of a graphite composite material, in particular of graphite sheets coated on both sides with carbon-fiber-reinforced plastic.

13. A transport container according to any one of claims 1 to 12, characterized in that said at least one outer door panel (5) forms said first insulation layer (2) of said door device and said at least one inner door panel (4) forms said second insulation layer (3) of said door device.

14. Transport container according to any one of claims 1 to 13, characterized in that the coolant reservoir (7) comprises an access portion (17) arranged in the opening of the container wall arrangement and that the at least one inner door panel (4) in its closed state cooperates with the access portion (17) on the side facing the access portion (17) in order to sealingly close off the interior chamber.

15. Transport container according to any one of claims 1 to 14, characterized in that at least one inner circumferential seal (11) is provided between the at least one inner door panel (4) and the opening of the container wall arrangement and at least one outer circumferential seal (10) is provided between the at least one outer door panel (5) and the opening of the container wall arrangement, and that a buffer space is arranged between the at least one inner door panel (4) and the at least one outer door panel (5).

16. Transport container according to claim 15, characterized in that the inner and the outer seal (10, 11) each comprise at least one sealing element which is displaceable by pressure difference and which opens a gas passage from the inside to the outside when a predetermined pressure difference is exceeded.

17. Transport container according to any one of claims 1 to 16, characterized in that the at least one inner door panel (4) comprises an inner aluminum shell (13) and an outer aluminum shell (14), and a vacuum thermal insulation, preferably vacuum insulation panels (3), is or are arranged between the inner and outer aluminum shells (13, 14) for thermal decoupling thereof.

18. Transport container according to any one of claims 1 to 17, characterized in that the coolant reservoir (7) comprises a vacuum thermal insulation (17) on the front side facing the opening of the container wall arrangement.