GB2515903A - A container deliminating a cargo space and a method for varying the insulation property of at least parts of a container - Google Patents

Abstract

A vehicle cargo container (10, fig 1) comprising at least one wall 10 having an inner wall 30 and an outer wall 40 spaced apart from the inner wall by at least one spacer 50 and thereby defining a chamber 60 between the inner and outer walls, the at least on wall having a valve 70 used to vary the thermal conductivity of the chamber. To effect the thermal conductivity the chamber may be evacuated by a vacuum motor 80 or the chamber may be filled with a low thermal conductive material. The spacer may be made from polyurethane foam, which has a low thermal conductivity. The inner wall may be made from glass reinforced plastics (grp) and the outer wall made from sheet steel. A cargo space (100) of the container may be cooled using a cooling device (90) and the container may be used for transporting perishable goods such as milk or fruit. The low thermal conductive wall reduces the cooling effort required by the cooling device.

Description

A Container Deliminating a Cargo Space and a Method for varying the Insulation Property of at least Parts of a container The invention relates to a container deliminating a cargo space of a vehicle according to the preamble of patent claim 1 as well as a method for varying the insulation property of at least parts of a container.

Such containers can be designed e.g. as a part of a trailer for a truck or as a container for a freight train or a cargo ship.

In order to keep perishable products or short-life food products such as e.g. milk products, fish or vegetables fresh, it is well-known from the general prior art to transport such products in insulated containers.

Such a container can already be taken as known from DE 11 2007 003 664 T5. The container there comprises an inner wall element and an outer wall element, wherein the inner wall element is facing a climated cargo space of the container and the outer wall element is facing the environment. The inner wall element and the outer wall element are spaced apart from each other by means of at least one foam insulator and at least one vacuum insulation plate. The vacuum insulation plate contains a particularly low pressure especially in comparison with the ambient pressure and, thus, the vacuum insulation plate is a particularly efficient insulator. In order to provide a particularly high stability of the inner wall element, the outer wall element and the container respectively, in a preferred embodiment of this invention the inner wall element and the outer wall element are spaced by means of wire elements.

Both by spacing the inner wall element and the outer wall element by means of an arrangement of foam insulators and vacuum insulation plates and additionally or alternatively by wire elements the full insulation potential of the container is not tapped.

It is the object of the resent invention to provide a container of the initially mentioned kind, which is insulated in a particularly efficient manner.

According to the invention, this object is solved by a container having the features of patent claim 1 and by a method having the features of patent claim 6. Advantageous embodiments with expedient further developments of the invention are indicated in the dependent patent claims.

In order to provide a container of the initially mentioned kind, which is insulated in a particularly efficient manner, it is provided according to the invention, that the wall element comprises a valve element, by means of which the thermal conductivity of the wall chamber is variable.

The container comprises several wall elements which are deliminating the cargo space of the container. The wall elements each comprise at least one inner wall element facing the cargo space or the loaded cargo respectively and the wall elements each comprise at least one outer wall element facing the environment. Due to the fact, that the inner wall element and the outer wall element are spaced apart by means of at least one spacer, a wall chamber of the wall element is defined by means of the inner wall element, the outer wall element and the at least one spacer. In other words the wall chamber is defined by the space between the inner wall element and the outer wall element and the wall chamber can be e.g. deliminated by the inner wall element, the outer wall element and e.g. two spacers, which are arranged on opposing ends between the inner wall element and the outer wall element. The wall chamber can be sealed e.g. by means of an overlapping wall element which extends at least from the inner wall element to the outer wall element, wherein this overlapping wall element is connected with the inner wall element and the outer wall element in such a manner, that the wall chamber is hermetically sealed. In order to vary the thermal conductivity of the wall element, the wall element comprises a valve element by means of which a medium, e.g. air within the wall chamber can be influenced. By means of the valve element e.g. the pressure within the wall chamber can be decreased due to pumping out the medium which is contained within the wall chamber. In other words the thermal conductivity of the wall element can be decreased e.g. by vacuuming the medium contained within the wall element or within the wall chamber respectively. As an alternative, by means of the valve element e.g. a medium with a particularly low thermal conductivity can be filled into the wall chamber in order to decrease the thermal conductivity of the wall element and, thus, increasing the insulating efficiency of the wall element.

The invention also relates to a method for varying the insulation property of at least parts of a container. The container is deliminating a cargo space of a vehicle. The container comprises at least one wall element having an inner wall element deliminating the cargo space at least partially and an outer wall element which is spaced apart from the inner wall element by means of at least one spacer and thereby building a wall chamber. The container comprises at least one valve element for changing the thermal conductivity of the wall chamber.

Due to changing the thermal conductivity of the wall chamber, also the thermal conductivity of the wall element and thus of the whole container can be changed in a very efficient manner by means of e.g. generating a vacuum due to pumping out the medium (e.g. air) contained in the wall chamber. By pumping out the medium the and thus generating a vacuum the thermal conductivity can be efficiently decreased whereby the container is insulated in a particularly efficient manner. In other words, by using the valve element for changing the thermal conductivity of the wall chamber, the container is appropriate for keeping the temperature in the cargo space constant (e.g. on a constant low level), wherein the container is made particularly appropriate for keeping perishable products fresh.

Further advantages, features, and details of the invention derive from the following description of a preferred embodiment as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not only in the respective indicated combination but also in any other combination or taken alone without leaving the scope of the invention.

The drawings show in: Fig. la a side view of a schematically illustrated container; Fig. lb a sectional view of the container according to a section line A-A in Fig. la; and in Fig. lc a sectional view of a wall element of the container according to a detail B which is marked with a rectangle in Fig. lb. In the figures the same elements or elements having the same functions are indicated with the same reference sign.

Fig. la shows a container 10 which comprise several wall elements 20, wherein this wall elements 20 deliminate a cargo space 100 of the container 10. The container 10 is particularly appropriate for keeping a temperature within the cargo space 100 at a particularly constant level, since the wall elements 20 comprise a very low thermal conductivity and since the container 10 also comprises a cooling device 90 by means of which the cargo space 100 can be cooled down or the temperature of the cargo space can at least be kept constant in order to keep loaded cargo fresh. In other words the container 10 is particularly appropriate for keeping a perishable cargo, such as milk products or fruits fresh over a long time with low cooling effort.

Fig. lb in conjunction with Fig. ic show a preferred embodiment of one of the wall elements 20 wherein Fig. lb shows a sectional view according to a section line A-A in Fig. la and Fig. lc shows a detailed view according to a detail B which is marked with an rectangle in Fig. lb. Fig. lc shows, that the wall element 20 comprises an inner wall element 30 which is deliminating at least one side of the cargo space 100 and, thus, deliminating the cargo space 100 at least partially and an outer wall element 40 which is facing the environment.

The inner wall element 30 and the outer wall element 40 are spaced apart from each other by means of two spacers 50 at present. In conjunction with Fig. 1 a it is cognizable, that the wall element 20 contains a wall chamber 60 which is deliminated by the inner wall element 30, the outer wall element 40, the two spacers 50 and at least two covering elements 110 which extend from the inner wall element 30 to the outer wall element 40 and, thus, seal the wall chamber 60 hermetically. It is clear, that the covering elements can also be designed as further wall elements 20. By means of the spacers 50 which are each connected with the inner wall element 30 and the outer wall element 40, the wall chamber 60 is also hermetically sealed. The covering elements 100 can be designed e.g. as metal sheets or designed as other elements which are capable of sealing the wall chamber 60. The wall element 20 also comprises a valve element 70, by means of which a medium contained in the wall chamber 60 can be influenced. The wall chamber 60 for example, contains air with ambient pressure and by means of the valve element 70, which can be connected with an external vacuum motor 80 or alternatively with a pressure pump the air contained in the wall chamber 60 can be pumped out, thus, creating a vacuum within the wall chamber 60. Due to generating a vacuum within the wall chamber 60 the thermal conductivity of the wall element 20 can be reduced significantly and, thus, perishable cargo contained within the cargo space can be kept fresh in a particularly efficient manner. Since the wall chamber 60 extends over a particularly wide area of both the inner wall element 30 and the outer wall element 40 a contact heat transfer only occurs in the area where the two spacers 50 are in contact with the inner wall element 30 and the outer wall element 40 respectively. In other words the heat transfer from the cargo space 100 through the wall element 20 and to the environment can be kept on a particularly low level if the contact surface between the spacers 50 and the inner wall element 30 and the outer wall element 40 respectively is particularly small. It is clear, that the wall chamber 60 can also be subdivided into several smaller chambers by means of partition walls (not shown) which act as further spacers between the inner wall element 30 and the outer wall element 40. Such partition walls increase the stability of the wall element 20. However due to contacting the inner wall element 30 and the outer wall element 40 the thermal conductivity of the wall element 20 would be increased due to contact heat transfer.

The spacers 50 are made of polyurethane foam which comprises a particularly low thermal conductivity and, thus, also in the contact area between the spacer 50 and the inner wall element 30 and the outer wall element 40 respectively the heat transfer from the environment to the cargo space 100 can be kept on a particularly low level. In order to combine a low weight with a low thermal conductivity of the inner wall element 30, the inner wall element 30 is preferably made of glass reinforced plastic (GRP). In order to achieve a particularly high mechanic stability of the wall element 20, the outer wall element 40 is preferably made of at least one steel sheet.

List of reference signs container waIl element inner wall element outer wall element spacer wall chamber valve element vacuum motor cooling device cargo space covering element

Claims (6)

1. Claims A container (10) deliminating a cargo space (100) of a vehicle, the container (10) comprising at least one wall element (20) having an inner wall element (30) deliminating the cargo space (100) at least partially and an outer wall element (40) which is spaced apart from the inner wall element (30) by means of at least one spacer (50) and thereby building a wall chamber (60), characterized in that, the wall element (20) comprises a valve element (70), by means of which the thermal conductivity of the wall chamber (60) is variable.
2. 2. The container (10) according to claim 1, characterized in that, the container (10) is chargeable with a vacuum by means of the valve element (70).
3. 3. The container (10) according to claim 1 or 2, characterized in that, the spacer (50) is made of polyurethane foam.
4. 4. The container (10) according to any one of claims 1 to 3, characterized in that, the inner wall element (30) is made of glass reinforced plastic.
5. 5. The container (10) according to any one of claims 1 to 4, characterized in that, the outer wall element (40) is made of at least one steel sheet.
6. 6. A method for varying the insulation property of at least parts of a container (10), the container (10) deliminating a cargo space (100) of a vehicle, the container (10) comprising at least one wall element (20) having an inner wall element (30) deliminating the cargo space (100) at least partially and an outer wall element (40)Swhich is spaced apart from the inner wall element (30) by means of at least one spacer (50) and thereby building a wall chamber (60), and the container (10) comprising at least one valve element (70) for changing the thermal conductivity of the wall chamber (60).