EP1625338B1 - Heat insulated container - Google Patents

Description

The invention relates to a thermally insulated container according to the preamble of claim 1.

Such thermally insulated containers are used, in particular, but by no means exclusively, for transport purposes in order to be able to transport temperature-sensitive goods, for example medicines, while maintaining narrow temperature tolerances. For this purpose, a container wall is provided in generic containers, which completely encloses an interior in which the goods to be transported are arranged. At least one closable opening is provided in the container wall in order to be able to introduce the goods to be transported into the container.

In order to keep the heat flow through the container wall as low as possible, vacuum insulation elements are used for insulation. These vacuum insulation elements have a very high thermal resistance with a relatively small layer thickness, so that for a given external volume there is a relatively large usable volume with sufficient thermal insulation. Due to the vacuum insulation elements, the heat flow is made more difficult both from the outside in and from the inside out, so that the goods to be transported are protected against both excessive heat and excessive cold. Thermally insulated containers are known from the prior art, in which active cooling systems are used for additional cooling. For example, it is known that the interior of the container is tempered by means of an electrical air conditioning system. Systems are also known in which dry ice is evaporated and the resulting cold steam is used to cool the interior. The disadvantage of these actively cooled containers is that they are extremely sensitive to interference. If, for example, the electrical air conditioning system or the fan of the dry ice system is not supplied with sufficient electrical energy, one is Sufficient cooling is no longer guaranteed and the transported goods spoil.

The EP 1 291 300 A2 , which forms the starting point of the present invention, discloses a thermally insulated container for transportation purposes. The container has four side walls, a bottom and a lid, which completely enclose an interior. An opening of the container can be closed by means of the lid. A side wall has an inner wall and an outer wall that form a pocket in which a vacuum insulation panel is arranged. Another side wall has a pocket in which a preconditioned element with a phase change material is arranged. The vacuum insulation panel has a multi-layer core, which is enclosed gas-tight by a flexible covering. The interior formed by the envelope through the gas-tight enclosure of the core is evacuated. With this container, the gas pressure inside the vacuum insulation panel cannot be checked.

The JP 08-068591 A shows a thermally insulated container with inner container and outer container and vacuum insulation elements arranged in between. The vacuum insulation elements are connected to a gas pressure control system. A line leads from each vacuum insulation element to the control system, which is located on the outside of the container.

Starting from this prior art, it is therefore the object of the present invention to propose a thermally insulated container in which the functionality of the vacuum insulation elements can be checked at any time even after installation in the container.

This object is achieved by a container according to the teaching of claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

The insulation effect of the vacuum insulation elements largely depends on the sufficiently low internal gas pressure in the vacuum insulation element. The further the internal gas pressure in the vacuum insulation element increases, the more more heat is conducted through the vacuum insulation element. In order to be able to check the functionality of the vacuum insulation elements at any time even after installation in the container, at least one vacuum insulation element has an internal control system for checking the gas pressure in the interior of the vacuum insulation element. For this purpose, metal platelets, for example, can be arranged below the enveloping film, the internal gas pressure then being able to be derived by applying a temperature jump using suitable diagnostic devices in the area of the metal platelets.

It is envisaged that the vacuum insulation element is installed behind the container wall, for example when using a double-walled container. According to the invention, there is an inspection opening in the container wall through which the control system for controlling the internal gas pressure in the vacuum insulation element is accessible. In this way, the functionality of the built-in vacuum insulation element can be checked again at any time, in particular before loading, in order to avoid damage to the goods to be transported due to insufficient insulation, as can be caused, for example, by micro-leaks in the vacuum insulation element.

In order to prevent damage to the vacuum insulation element due to the penetration of foreign bodies, the inspection opening can be closed with a cover, which is preferably transparent, so that the control system located behind the cover can be viewed from the outside.

The invention is based on the basic idea of arranging passive melt storage elements in the container which are filled with a suitable melt storage material. Such melt storage elements have the property that they can store or emit a certain amount of heat through phase transformation of the melt storage material. In other words, this means that the melt storage material in the melt storage element when heated, it melts until the entire supply of melt storage material has passed into the liquid phase. The thermal energy required for phase transformation of the melt storage material is thus stored in the melt storage material and does not lead to an increase in temperature. If the melt storage material is cooled in reverse, the melt storage material gradually solidifies and releases the stored amount of heat during this phase change. As a result, the melt storage elements buffer the heat flow according to their respective capacity until the capacity limits are reached.

Depending on the melting point of the melt storage material, there are other buffering areas for buffering the heat flow. If the melt storage material contains paraffin, for example, heat flow buffering in the temperature range above 0 ° C is made possible. If, on the other hand, a salt solution is contained in the melt storage material, the heat flow in the temperature range below 0 ° C can be buffered.

Since each melt storage material has an optimal buffering range depending on its respective melting point, it is particularly advantageous for certain applications if at least two different melt storage elements are provided in the container, each of which is filled with different melt storage materials. This combination of different melt storage materials in one container allows the buffering area to be spread out. It is particularly advantageous if the melt storage elements filled with different melt storage materials are arranged in several layers in the container.

In order to be able to check the readiness for use of the melt storage elements, for example after loading a container, it is advantageous if temperature measuring devices are provided on the melt storage elements with which the temperature of the melt storage element can be measured. Known temperature sensors with displays, for example, which change color depending on the temperature, can be used for this purpose.

The construction of the vacuum insulation elements is basically arbitrary. According to a preferred embodiment, a base body is used for this purpose, which is enclosed in a gas-tight manner with a film. The interior space formed by the film is evacuated in order to be able to achieve the desired insulation properties. The base body itself gives the vacuum insulation element the required mechanical stability, and open-pore materials should be used to produce the base body in order to ensure sufficient evacuation.

If foil-coated vacuum insulation elements are used, these should preferably not have any protruding edge flaps made of foil, so that the butt joint between adjacent vacuum insulation elements can be made as narrow as possible.

To increase the heat flow resistance, the vacuum insulation elements can also be arranged in several layers one above the other or one behind the other. The resulting heat flow resistance essentially results from the addition of the heat flow resistance of the individual layers.

According to a first embodiment of the invention, the container can be designed in the manner of a transport container. If this transport container is also airworthy, temperature-sensitive goods, such as medicines such as vaccines in particular, can be transported over very long distances and long transport times within specified temperature tolerances.

Alternatively, the container can also be designed in the manner of a transport box with a removable lid. Such transport boxes are particularly advantageous if the container is not to be transported back, but rather the container is disposed of after reaching the destination.

In order to reduce the costs of the transport box, it is conceivable to insulate only partial areas of the container wall of the transport box, in particular the lid and base of the transport box, with at least one vacuum insulation element, since, for example, the large surface of the lid and base means that allow relatively large amounts of heat to pass through, whereas other parts of the container wall are of minor importance.

Foamed plastics are particularly suitable for producing the container wall of the transport box, since this material itself has a high heat flow resistance and is also available at very low cost.

By installing several vacuum insulation elements in the different container walls, an improved damage redundancy is achieved, since if a single vacuum insulation element is damaged, the insulation properties of the container are only influenced relatively little.

An embodiment of the invention is shown schematically in the drawings and is explained below by way of example.

Fig. 1

einen Transportcontainer in perspektivischer Ansicht von außen;

Fig. 2

den Transportcontainer gemäß Fig. 1 mit geöffneter Tür in perspektivischer Ansicht;

Fig. 3

den Transportcontainer gemäß Fig. 1 im Querschnitt;

Fig. 4

die Behälterwandung des Transportcontainers gemäß Fig. 1 im perspektivischen Schnitt;

Fig. 5

die Schmelzspeicherelemente des Transportcontainers gemäß Fig. 1 in perspektivischer Ansicht;

Fig. 6

die Anordnung der Vakuumisolationselemente an einer Seitenwandung des Transportcontainers gemäß Fig. 1 in seitlicher Ansicht;

Fig. 7

eine Revisionsöffnung in einer Behälterwandung des Transportcontainers gemäß Fig. 1;

Fig. 8

ein Vakuumisolationselement des Transportcontainers gemäß Fig. 1 im Querschnitt;

Fig. 9

den Datenspeicher am Transportcontainer gemäß Fig. 1 in vergrößerter perspektivischer Ansicht;

Fig. 10

die Innentemperaturkurve im Innenraum des Transportcontainers gemäß Fig. 1 bei Aufbringung eines positiven Außentemperatursprungs;

Fig. 11

die Innentemperaturkurve im Innenraum des Transportcontainers gemäß Fig. 1 bei Aufbringung eines positiven und eines negativen Außentemperatursprungs;

Fig. 12

die Innentemperaturkurve im Innenraum des Transportcontainers gemäß Fig. 1 bei Durchlaufen eines Außentemperaturprofils.

Show it:

Fig. 1

a transport container in a perspective view from the outside;

Fig. 2

the transport container according to Fig. 1 with opened door in perspective view;

Fig. 3

the transport container according to Fig. 1 in cross section;

Fig. 4

the container wall of the transport container according to Fig. 1 in perspective section;

Fig. 5

the melt storage elements of the transport container according to Fig. 1 in perspective view;

Fig. 6

the arrangement of the vacuum insulation elements on a side wall of the transport container according to Fig. 1 in a side view;

Fig. 7

an inspection opening in a container wall of the transport container according to Fig. 1 ;

Fig. 8

a vacuum insulation element of the transport container according to Fig. 1 in cross section;

Fig. 9

the data storage on the transport container according to Fig. 1 in an enlarged perspective view;

Fig. 10

the inside temperature curve in the interior of the transport container according to Fig. 1 when applying a positive jump in outside temperature;

Fig. 11

the inside temperature curve in the interior of the transport container according to Fig. 1 when applying a positive and a negative jump in outside temperature;

Fig. 12

the inside temperature curve in the interior of the transport container according to Fig. 1 when going through an outside temperature profile.

In Fig. 1 a container 01 designed in the manner of a transport container is shown in perspective. In container 01, heat-sensitive goods, for example medication, in particular vaccines, can also be transported over long distances by plane. The base area of container 01 corresponds to the area of a standard pallet.

The container wall 02 of the container 01 consists of three rectangular side wall elements 03, a rectangular bottom element 04, a rectangular ceiling element 05 and a pivotably mounted door element 06. The three side wall elements 03, the bottom element 04 and the ceiling element 05 are firmly connected to one another to form a rectangular interior 07 connected. After closing the door element 06, the interior 07 is enclosed on all sides and is insulated against the flow of heat through the container wall 02 by means of vacuum insulation elements, which are described in more detail below.

A locking element 08 is used to lock the door element 06, by actuating it in Fig. 1 Locking elements, not shown, can be unlocked or locked. A seal can be attached to the closure member 08 in order to secure container 01 against unauthorized opening. As an alternative or in addition to this, a lock, for example a cylinder lock or a number lock, can also be provided on the closure member 08 in order to prevent unauthorized opening of the container 01.

On the underside of the base element 04, two strips 09 are attached, through which an intermediate space is formed between the base element 04 and the contact surface. The tines of a transport forklift can be inserted into this space in order to be able to lift and transport the container 01 with a forklift. A data storage device 10 is fastened in a recess on the top of the door element 06 and is protected from the outside by a cover 11 (see also Fig. 9 ). To protect the container wall 02 against the penetration of pointed objects, guard rails 15 can be attached to the outside in particularly endangered areas. The guardrails 15 can be made of sheet metal, for example.

The inside structure of the container 01 is off Fig. 2 seen. Six melt storage elements 16 and 17 are arranged on the inside of each of the two side walls 03. The melt storage elements 16 are filled with a paraffin-containing melt storage material, whereas the melt storage elements 17 contain a salt solution. Fastening rails 18 are used to fasten the melt storage elements 16 and 17 (see also Fig. 3 ), which encompass the melt storage elements 16 and 17 in a form-fitting manner at the upper and lower edges, respectively. In this way, the melt storage elements 16 and 17 can be replaced simply by pushing them into the fastening rails 18 from the door side. After closing the door element 06, the melt storage elements 16 and 17 are fixed on the inside of the container wall 02. This type of attachment allows, in particular, the melt storage elements 16 and 17 to be assembled or disassembled without tools.

Inspection openings 19 are provided in each of the three side wall elements 03, the base element 04, the ceiling element 05 and the door element 06, the function of which will be explained in detail below.

On the outside of the door element 06, a sealing lip 20 is fastened on the inside, with which the sealing joint between the door element 06 on the one hand and the edge of the two opposite side wall elements 03 or the edge of the ceiling element 05 and the floor element 04 is sealed after the door element 06 is closed.

In Fig. 3 the container 01 is shown schematically in cross section from the front. The flat, namely plate-shaped melt storage elements 16 and 17 are arranged parallel to the container wall 02 on the inside 21 of the container 01. The container wall 02 itself is constructed with double walls from a dimensionally stable outer wall 22 and a likewise dimensionally stable inner wall 23. The vacuum insulation elements 24 provided for insulation are arranged between this mechanically stable double wall comprising the outer wall 22 and the inner wall 23. Shock protection elements 25 made of foamed plastic are provided between the vacuum insulation elements 24 and the outer wall 22. The size relationships between the outer wall 22, inner wall 23, the vacuum insulation elements 24 and the shock protection elements 25 are shown in Fig. 3 only hinted at in principle. The exact structure of the structure of the container wall 02 is off Fig. 4 seen.

The in Fig. 4 Perspective cross section through the container wall 02 shown shows that the outer wall 22 and the inner wall 23 are each made of a sandwich material. In this sandwich material, an inner core layer 26 made of plywood and an inner core layer 27 made of foamed plastic are each covered on the outside by cover layers 28 made of fiber-reinforced plastic.

In Fig. 5 A possible embodiment of dimensionally stable melt storage containers 29 is shown. By filling the container 29 with The different types of melt storage elements 16 and 17 can be made from a suitable melt storage material.

In Fig. 6 the arrangement of the vacuum insulation panels 24 in a side wall 03 is shown as an example. Four vacuum insulation elements 24 are arranged adjacent to one another in all side wall elements 03 and correspondingly also in floor element 04, in ceiling element 05 and in door element 06. This ensures that if a vacuum insulation element is damaged, for example caused by a micro leak, not all of the insulation in the corresponding container wall fails. Rather, even if a single vacuum insulation element fails, there is still sufficient insulation of the container 01 as a whole. The flat vacuum insulation elements 24 designed in the manner of thermal insulation boards touch in butt joints 30. In order that as little heat as possible is transferred in the butt joints 30, an insulating material can be arranged in the butt joints 30. In addition, the vacuum insulation elements 24 should, if possible, not have any protruding film tabs, so that vacuum insulation elements 24 can be mounted in the butt joints 30 as tightly as possible. In order to increase the heat flow resistance, a further layer of vacuum insulation elements can also be provided in the container wall 02, the butt joints 30 being offset from one another if possible in the case of a plurality of layers.

A control system 31 for checking the internal gas pressure is present on each vacuum insulation element 24. The four control systems 31 of the four vacuum insulation elements 24 are each arranged adjacent to one another in the middle of the container wall, so that the four different control systems 31 are accessible through a single inspection opening 19.

In Fig. 7 the inspection opening 19 is shown enlarged with the four control systems 31 arranged behind a cover 32. To check the internal gas pressure in the vacuum insulation elements 24, the cover 32 is removed and a test head of a diagnostic device is placed on the control systems 31 hung up. Structure and function of the control system 31 and structure of the vacuum insulation elements 24 are off Fig. 8 seen.

The in Fig. 8 The cross section shown through the vacuum insulation elements 24 shows an open-pore base body 33 which is gas-tightly covered with a film 34. The gas-tight interior 35 formed by the film 34 is evacuated in order to give the vacuum insulation element 24 the desired insulation properties. To check the internal gas pressure in the interior 35 of the vacuum insulation element 24, the control system 31, which consists of a metal plate 36 and an intermediate layer 37, is placed on the inside of the film 34. A defined temperature jump can then be applied to the control system 31 with a test head 38, the internal gas pressure in the interior 35 being able to be derived from the signal response to the temperature jump.

How from Fig. 9 As can be seen, the data storage device 10 is connected via a cable 12 to an internal temperature sensor for measuring the temperature in the interior 07 and to an external temperature sensor for measuring the ambient temperature surrounding the container 01. The internal temperature and the external temperature are measured at regular time intervals and the measurement data obtained are stored in the data storage device 10 for documentation purposes. The current inside temperature or the current outside temperature can be shown on a display 13 and can be read from the outside through the transparent cover 11. A GPS receiver (not shown) can be connected to the data storage device 10 via a connection 14, so that the position data of the container 01 can be stored with the data storage device 10 for documentation purposes.

The function of the container 01 for temperature insulation should be based on the in 10 to 12 temperature curves shown are exemplified.

In Fig. 10 a situation is schematically shown in which the container 01 is exposed to an outside temperature profile 39. The corresponding change in the internal temperature in the interior 07 of the container 01 is indicated with the internal temperature profile 40. The outside temperature profile 39 includes a temperature jump from 10 ° C to 30 ° C over a period of 6 hours. This change in the outside temperature initially does not lead to a change in temperature in the interior 07, because the amounts of heat that are let through by the vacuum insulation elements 24 are buffered by the melt storage elements 16 and 17 by phase transformation of the melt storage material. Only after a time delay, when large amounts of the melt storage material have already undergone a phase change, does the interior temperature in the interior 07 rise very slowly.

Out Fig. 11 a second outside temperature profile 41 and the resulting inside temperature profile 42 are plotted in the interior 07 of the container 01. After the positive temperature jump to 30 ° C., the outside temperature profile 41 immediately undergoes a negative temperature jump to just above 0 ° C. The negative temperature jump also lasts 6 hours. The negative temperature jump is also buffered by the melt storage elements 16 and 17, the melt storage elements regenerating again by lowering the temperature, so that a subsequent positive temperature jump can in turn be buffered without further notice.

In Fig. 12 a real outside temperature profile 43 and a resulting inside temperature profile 44 are plotted, which was recorded in a long-term test over 210 hours. The different curves of the outside temperature profile 43 and the inside temperature profile 44 correspond to the different measuring points outside or inside the container 01 Fig. 11 immediately apparent, the inside temperature remains within a narrow temperature band despite considerable fluctuations in the outside temperature, so that temperature-sensitive goods in the interior of the container 07 are effectively protected against excessive temperature fluctuations.

Claims (5)

1. Thermally insulated container (01), in particular for transport purposes, having a container wall (02) which completely encloses an interior (07), wherein the container wall (02) has a closeable opening via which the interior (07) is accessible from outside, having at least one vacuum insulation element (24) in the container wall (02), by means of which element the interior (07) is insulated against heat exchange, and having at least one passive melt-storage element (16; 17) which is filled with a melt-storage material, wherein the at least one vacuum insulation element (24) has a base body (33) made of an open-pore material which is enclosed by a film (34) in a gas-tight manner, wherein the interior (35) formed by the film (34) by the gas-tight enclosing of the base body (33) is evacuated,
   characterized
   in that the at least one vacuum insulation element (24) has an internal monitoring system (31) for monitoring the gas pressure in the interior (35) of the vacuum insulation element (24),
   in that in the container wall (02) an inspection opening (19) is present, through which the monitoring system (31) for monitoring the internal gas pressure in the vacuum insulation element (24) is accessible, and
   in that the inspection opening (19) can be closed by a cover (32).
2. Container according to Claim 1, characterized
   in that four vacuum insulation elements (24) are arranged adjacently to one another in the container wall (02),
   in that the four monitoring systems (31) of the four vacuum insulation elements (24) are each arranged adjacently to one another in the centre of the corresponding container wall (02), and
   in that the inspection opening (19) is arranged in such a way that the four monitoring systems (31) are accessible through a single inspection opening (19).
3. Container according to one of Claims 1 to 2, characterized in that the film (34) of the vacuum insulation element (24) has no projecting edge laps.
4. Container according to one of Claims 1 to 3, characterized in that the vacuum insulation element (24) has a layer thickness of 5 mm to 100 mm.
5. Container according to one of Claims 1 to 4, characterized in that on at least one melt-storage element (16; 17) a temperature-measuring device is provided, in particular a temperature sensor which changes colour in dependence on the temperature, by means of which the temperature of the melt-storage element (16; 17) can be measured.

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