EP3671078B1 - Thermally 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, such as medication, while maintaining narrow temperature tolerances. For this purpose, in the case of generic containers, a container wall is provided 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 heat transfer 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. The vacuum insulation elements make it more difficult for heat to flow 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 controlled by an electric air conditioning system. Systems are also known in which dry ice is evaporated and the resulting cold steam is used to cool the interior. These actively cooled containers have the disadvantage that they are extremely sensitive to interference. For example, if the electric air conditioning or the fan of the dry ice system is not supplied with sufficient electrical energy, this is a Sufficient cooling is no longer guaranteed and the transported goods spoil.

The document WO 2000/40908 A1 discloses a portable refrigerator with a thermally insulated outer shell that defines an interior space. The outer shell is formed by several wall elements, namely three side wall elements, a ceiling element, a floor element and a door element, with the interior having at least one closable opening. The outer shell has two metal skins and a heat-insulating polyurethane foam layer in between. The well-known refrigerator has supports for melt storage elements.

The document JP 2003-106760 A discloses a thermally insulated, movable container with a multi-walled container wall, which consists of two glass fiber reinforced plastic panels, a plywood panel and a thermal insulation layer made of ceramic. Vacuum insulation elements are arranged in the container wall. In addition, cooling elements are attached to the side walls of the container by means of a holder.

The document JP S63-188481 U also discloses a movable container in which cooling elements can be inserted into fastening rails from the door side.

The document DE 101 48 587 C1 discloses a temperature-controlled container in which an insulating body is foamed into the lid and the foot part. The insulating body consists of one or more layers of metal-coated plastic films, which rest on one or more layers of glass fleece, which are supported by support structures to enable evacuation of the insulating body.

The document JP H04 302978 A discloses a container with an integrated active cooling unit to pass cooling air through the cooling chamber.

The document WO 97/12100 A1 discloses a vacuum insulation panel embedded in another material such as foam.

The document EP 1 045 079 A2 discloses a multi-layer thermal insulation wall, with several vacuum insulation panels foamed between two rigid foam panels.

DE 100 15 876 A1 discloses designing foil wrappings for VIP in such a way that there are no protrusions of the foil or weld seams on the end faces of the VIP that would interfere with installation.

Based on this prior art, it is an object of the present invention to propose a thermally insulated container with an alternative thermally insulating wall construction.

This task is solved by a container according to the teaching of claim 1.

Advantageous embodiments of the invention are the subject of the subclaims.

The invention is based on the basic idea of arranging passive melt storage elements in the container that are filled with a suitable melt storage material. Such melt storage elements have the property that they can store or release 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 melts when heated until the entire supply of melt storage material has passed into the liquid phase. The thermal energy required for the 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 conversely, the melt storage material gradually solidifies and releases the stored amount of heat during this phase transformation. 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 is made possible in the temperature range above 0° C. If, on the other hand, the melt storage material contains a salt solution, for example, the heat flow can be buffered in the temperature range below 0° C.

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 expanded. 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. For this purpose, for example, known temperature sensors with displays can be used that change color depending on the temperature.

In the container according to the invention, the container wall is double-walled with an outer wall and an inner wall. The outer wall and the inner wall are each designed to be mechanically stable and self-supporting. The interior is insulated against heat exchange with several vacuum insulation elements. The vacuum insulation elements are arranged between the outer wall and the inner wall.

The type of construction in which the vacuum insulation elements are designed 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 achieve the desired insulation properties. The base body itself gives the vacuum insulation element the required mechanical stability, whereby open-pored materials should be used to produce the base body in order to ensure sufficient evacuation.

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

The insulation effect of the vacuum insulation elements depends largely on the fact that there is a sufficiently low internal gas pressure in the vacuum insulation element. The further the internal gas pressure in the vacuum insulation element increases, the 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, the vacuum insulation elements should have a control system to monitor the internal gas pressure. For this purpose, for example, metal plates can be arranged below the covering film, whereby the internal gas pressure can then be derived using suitable diagnostic devices in the area of the metal plates by applying a temperature jump.

If the vacuum insulation elements are installed behind the container wall, for example when using a double-walled container, the container wall should have inspection openings through which the control system for checking the internal gas pressure is accessible. In this way, the functionality of the installed vacuum insulation elements can be checked again at any time, especially before loading, in order to avoid damage to the goods to be transported due to insufficient insulation, such as can be caused, for example, by microleaks in the vacuum insulation elements.

In order to exclude damage to the vacuum insulation elements due to the ingress of foreign bodies, covers can be provided on the inspection openings, which are preferably transparent so that the control system located behind the cover can be viewed from the outside.

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, for example medications such as vaccines, can be transported over very long distances and long transport times within specified temperature tolerances.

In an alternative, unclaimed embodiment, the container can also be designed in the form of a transport box with a removable lid. Such transport boxes are particularly advantageous if the container is not intended to be transported back, but rather the container is disposed of after it has reached its destination.

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

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

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

Show it:

Fig. 1

a transport container in a perspective view from the outside;

Fig. 2

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

Fig. 3

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

Fig. 4

the container wall of the transport container accordingly 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 Fig. 1 in side view;

Fig. 7

an inspection opening in a container wall of the transport container 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 Fig. 1 in an enlarged perspective view;

Fig. 10

the internal temperature curve in the interior of the transport container Fig. 1 when a positive outside temperature jump is applied;

Fig. 11

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

Fig. 12

the internal temperature curve in the interior of the transport container Fig. 1 when running 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, such as medicines, especially vaccines, can be transported over long distances, even 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 base element 04, a rectangular ceiling element 05 and a pivotally mounted door element 06. The three side wall elements 03, the base element 04 and the ceiling element 05 are fixed together to form a rectangular interior 07 tied together. 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 element 08 to secure the container 01 against unauthorized opening. Alternatively or in addition to this, a lock, for example a cylinder lock or number lock, can also be provided on the closure element 08 in order to prevent unauthorized opening of the container 01.

Two strips 09 are attached to the underside of the floor element 04, through which a gap is formed between the floor element 04 and the contact area. 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 To prevent the penetration of sharp objects, guard rails 15 can be attached to the outside in particularly vulnerable areas. The guard rails 15 can be made, for example, from a metal sheet.

The inside structure of container 01 is finished Fig. 2 visible. Six melt storage elements 16 and 17 are arranged on the inside 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 grip 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 makes it possible, in particular, to assemble or disassemble the melt storage elements 16 and 17 without tools.

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

On the outer circumference of the door element 06, a sealing lip 20 is attached on the inside, with which, after the door element 06 is closed, the 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.

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 double-walled and made of one dimensionally stable outer wall 22 and an equally dimensionally stable inner wall 23. The vacuum insulation elements 24 provided for insulation are arranged between this mechanically stable double wall made of outer wall 22 and 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, the inner wall 23, the vacuum insulation elements 24 and the impact protection elements 25 are in Fig. 3 only hinted at in principle. The exact structure of the construction of the container wall 02 is out Fig. 4 visible.

The in Fig. 4 The illustrated perspective cross section through the container wall 02 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 containers 29 with a suitable melt storage material, the different types of melt storage elements 16 and 17 can be produced.

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 the floor element 04, in the ceiling element 05 and in the door element 06. This ensures that if a vacuum insulation element is damaged, for example caused by a microleak, not all of the insulation in the corresponding container wall fails. Rather, even if an individual vacuum insulation element fails, the container 01 as a whole is still adequately insulated. The flat vacuum insulation elements 24, designed in the manner of thermal insulation panels, touch each other in butt joints 30. This means that as little heat as possible in the butt joints 30 is transferred, an insulating material can be arranged in the butt joints 30.

In addition, the vacuum insulation elements 24 do not have any protruding film tabs, so that vacuum insulation elements 24 can be mounted tightly in the butt joints 30. To increase the heat flow resistance, a further layer of vacuum insulation elements can also be provided in the container wall 02, with several layers the butt joints 30 should be offset from one another if possible.

A control system 31 for controlling 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. The structure and function of the control system 31 and the structure of the vacuum insulation elements 24 are off Fig. 8 visible.

The in Fig. 8 Cross section shown through the vacuum insulation elements 24 shows an open-pored base body 33, which is covered in a gas-tight manner by 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 using a test head 38, with the internal gas pressure in the interior 35 being able to be derived from the signal response to the temperature jump.

How out 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 inside temperature and the outside temperature are measured at regular intervals and the resulting measurement data is stored in the data storage device 10 for documentation purposes. The current indoor temperature or the current outdoor temperature can be displayed on a display 13 and 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 Fig. 10 to Fig. 12 Temperature curves shown can be explained as examples.

In Fig. 10 A situation is shown schematically 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 plotted 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 the vacuum insulation elements 24 are buffered by the melt storage elements 16 and 17 through phase transformation of the melt storage material. Only after a time delay, when large quantities of the melt storage material have already undergone a phase transformation, does the internal temperature in the interior 07 rise very slowly.

Out of Fig. 11 is a second outside temperature profile 41 and the resulting inside temperature profile 42 in the interior 07 of the container 01. After the positive temperature jump to 30 ° C, the outside temperature profile 41 immediately goes through a negative temperature jump to just over 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, with the melt storage elements in turn regenerating themselves by lowering the temperature, so that a subsequent positive temperature jump can again be easily buffered.

In Fig. 12 A real outside temperature profile 43 and a resulting inside temperature profile 44 are shown, which were 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 and inside the container 01. As shown Fig. 11 Immediately apparent, the internal temperature remains within a narrow temperature band despite significant fluctuations in the external temperature, so that temperature-sensitive goods in the interior of the container 07 are effectively protected from excessive temperature fluctuations.

Claims (12)

1. Thermally insulated container, in particular for transportation purposes, having a container wall (02) which completely encloses an interior space (07) and is formed by a plurality of wall elements (03, 04, 05, 06), namely three side wall elements (03), a top element (05), a bottom element (04) and a door element (06), the interior space (07) having at least one closable opening and a plurality of passive melt storage elements (16, 17) being provided in the container (01), each of which is filled with a melt storage material,

   wherein the container wall (02) is double-walled with an outer wall (22) and an inner wall (23),

   wherein the outer wall (22) and the inner wall (23) are each mechanically stable and self-supporting,

   the interior (07) being insulated against heat exchange by a plurality of vacuum insulation elements (24), and

   wherein the vacuum insulation elements (24) are arranged between the outer wall (22) and the inner wall (23),

   characterized in that

   in each individual wall element (03, 04, 05, 06) a plurality of vacuum insulation elements (24) are provided for insulation and

   each vacuum insulation element (24) has a base body (33) made of an open-pored material which is enclosed in a gas-tight manner by a film (34), the interior (35) formed by the film (34) being evacuated, the film (34) of each vacuum insulation element (24) having no projecting edge flaps.
2. Container according to claim 1, characterized in that the melt storage elements (16, 17) can be detachably fastened in the container (01), in particular without tools, preferably wherein a plurality of fastening rails (18) are provided for fastening the melt storage elements (16, 17) in the container (01), which embrace an edge of the melt storage elements (16, 17) in a form-fitting manner.
3. Container according to claim 2, characterized in that the melt storage elements (16, 17) are replaceable in that they can be pushed into the fastening rails (18) from the door side in such a way that, after closing the door element (06), the melt storage elements (16, 17) are fixed to the inside of the container wall (02).
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 the vacuum insulation elements (24) are designed in the manner of thermal insulation panels or vacuum insulation panels.
6. Container according to one of claims 1 to 5, characterized in that an insulating body is formed by several vacuum insulation elements (24), which encloses the inner volume (07) on all sides.
7. Container according to one of claims 1 to 6, characterized in that the outer wall (22) and the inner wall (23) are made of a lightweight material.
8. Container according to claim 7, characterized in that the outer wall (22) and/or the inner wall (23) is made of a sandwich material, preferably with several layers of material (26, 27, 28).
9. Container according to one of claims 1 to 8, characterized in that the container (01) is designed in the manner of a transport container, in particular a transport container suitable for air travel,
   preferably wherein the door element (06) is designed as a movably mounted door (06) for closing the opening of the interior (07) of the transport container (01), wherein the door (06) is mounted so as to be pivotable in particular about a vertical axis.
10. Container according to claim 9, characterized in that the transport container (01) has functional elements (09) for the engagement of forklift tines.
11. Container according to one of claims 9 to 10, characterized in that two strips are attached to the underside of the bottom element (04), by means of which strips an intermediate space is formed between the bottom element (04) and a contact surface, the tines of a transport forklift being insertable into this intermediate space in order to be able to lift and transport the container (01) with a forklift.
12. Container according to one of claims 1 to 11, characterized in that a supporting frame, in particular made of metal profiles, is provided on the container (01) for mechanically supporting the container wall (02).

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