Shape-retaining cooling elements for transporting goods in a cooled state
For packaging that requires an effective cooling effect but does not have the space to accommodate a traditional refrigerator, dometic cooling units De Ridder offers shape-retaining cooling elements. They are available in various shapes and sizes to fit the specific packaging needs of different customers.
The Cooling Element
A cooling element according to the invention comprises two layers of foil material between which an intermediate layer of liquid-absorbing, vapour-releasing material is accommodated, said two layers of foil material being fastened to one another by means of welded connections such that a compartment is formed between them. The compartment is preferably in liquid communication with a buffer reservoir via at least one flow restriction.
The cooling element is characterised in that a plurality of welds are provided at locations where the layers of foil material are welded together by constituting the welds through part of the intermediate layer and blending the weld at least locally around the material of the intermediate layer, as shown in figure 1. This process ensures the tight bonding of the two layers of foil material to one another and also prevents local weakening caused by the welding and compression processes.
Furthermore, the welded connections are rounded at their corners and ends so that the stress concentrations on the foil material adjacent the welded connections can be reduced. This is especially useful in the case of a cooling element that is sewn to an object, such as a rucksack, as the rounded edges of the welded connections can help to avoid stress concentrations and tears when the cooled element is bent during use.
Further welded connections 7 are also provided between the layers of foil material within the circumference of the compartment 5. These welded connections provide additional sealing between the layers of foil material and the intermediate layer and make it easier for the cooling element to be handled.
This is particularly the case when it is necessary to carry the cooling element with the user and thereby make frequent adjustments to the size of the compartment. In order to obtain precisely one filling of the liquid absorbing vapour-releasing material, which is typically a wick, without allowing water pockets to arise, a buffer reservoir with a maximal volume essentially equal to the liquid volume of the wick when it is saturated with liquid may be provided at locations between the welded connections 4 and 7. This provides for a more consistent cooling effect.
The invention further relates to a high temperature heater that has a working range of ambient temperatures to 250oC and comprises a ceramic body with a tungsten cap enclosing a platinum resistive type heater, a “K-type” thermocouple, and a magnet. The high temperature heater is also suitable for transport with a return flow and can be used as an alternative to the regular cooling element in combination with Phase Change Materials.
