DE29519234U1 - Foil-heated food container - Google Patents

Description

Schumacher, Helmut, Flamschen 41, 48653 Coesfeld "Foil-heated food container"

The innovation concerns a food container after the upper

scope of claim 1.

Such food containers are known, for example, in the form of warming devices, mobile food serving trolleys, etc. The food is heated by a heating element in the form of a heating

coil heated.

The radiator used reaches such high temperatures that it must be placed at a distance from the surface to be heated and its heat energy must be transferred to this surface only

in the form of radiant heat and convection. The radiation component is high and is emitted from all sides, also to the sides and downwards, so that despite insulation provided below the radiator, floor temperatures of 75° C and higher can be achieved, for example with the arrangement

tion in food serving trolleys.

This heating of the floor area represents an undesirable release of energy, as it cannot be used to heat the food.

a large number of food containers, for example a number of food serving trolleys, room temperatures can be achieved that require air extraction or air cooling using air conditioning units in order to maintain room temperatures of a maximum of 25° C.

This results in a double energy loss:

On the one hand, due to the heating energy that has to be used,

but is not used to heat the food, and

secondly, the additional energy that must be used to reduce the temperatures resulting from this excess heating energy to a level that is tolerable for the staff.
5

The innovation is based on the task of improving a generic food container so that the food can be heated using as little energy as possible.
10

This problem underlying the innovation is solved by the design of a food container according to the features of claim 1.

In other words, the innovation proposes to replace the

highly heatable serpentine rod or tubular heating elements to use a foil heater which has only a low radiation output and which transfers its heat energy directly to the surface to be heated to a high degree through a heat-conducting contact with this surface, so that the

Accordingly, hardly any unused heat energy is released by this foil heating. This enables considerable energy savings, as the heating energy used has significantly less loss.

Additional energy savings when heating up or keeping food warm are achieved because the ambient temperature is heated up less due to the lower losses, so that additional cooling or extraction measures can be dispensed with.

Furthermore, the lower temperature level achieved with the foil heating inside the food container enables the use of foamed insulation materials, so that inexpensive insulation panels or insulation blocks can be used, which

Moreover, they are produced with low energy consumption.

In contrast, the known devices require the use of mineral insulation materials for thermal insulation due to the high temperature level of the radiators used there, whereby the production of such mineral insulation materials involves a considerable

is associated with energy consumption.

Finally, by using foil heating, the food container can have smaller housing dimensions, thus lighter and using fewer raw materials and

and thus can be produced using less energy. The smaller dimensions are due to the low height of the foil heater and to reduced safety distances, which have to be considerably larger when using the very highly heated pipe heating element.

had to.

If necessary, the foil heating can have parts that can be arranged on the side of the trough to be heated, so that radiation losses on the trough walls are reduced.

can be decorated and the heating power used at the bottom of the trough can be further reduced. In this way, a uniform and overall low temperature level can be achieved within the food container with the correspondingly low temperature losses.

Heating can only be provided by such side-mounted foil heaters.

Thanks to the easily adjustable temperature conditions, it is possible to directly heat the trays containing the food using a foil heater arranged in accordance with the new system. Overheating or burning of the food can be effectively avoided thanks to the easy control of the foil heaters. Alternatively, however, it can be provided, as with the well-known food dispensers.

loading wagon a trough initially to accommodate a water

bath, whereby this water bath or the trough is heated to the desired temperature by the foil heating. Separate containers that hold the food can be placed in such water bath troughs, so that only indirect heating of the food via the

between the foil heating and the food in a water bath. ■'

A foil heater arranged in accordance with the innovation can therefore be used advantageously within a food container designed as a food serving trolley. Without the need for this food container to be mobile, a food serving container can be created that is placed on a table, for example. The low temperature level in the base area of the container enables this food serving container to be designed relatively flat, since extensive insulation is not required, which would otherwise have to take account of overheating and the risk of fire in the base area of the container, especially if it is placed on a table top.

The reduced temperature level inside the food serving container outside the trough holding the food enables the use of sensors that enable digital measurement signals and a corresponding

Temperature display on the outside of the food container and electronically controllable heating power using inexpensive and commercially available components . Monitoring the temperature, for example in a food serving trolley in a water bath

is made easier and more cost-effective than the conventional use of capillary tube thermometers, whereby such capillary tube thermometers are often the only option when using the heating coils mentioned above due to the temperatures prevailing inside the device.

usable measuring instruments.

An example of the innovation is explained in more detail below using the drawing.

Fig. 1 is a schematic view of a food dispensing

car, with some areas cut

are provided and

Fig. 2 shows a similarly sectioned diagram of part of a food serving trolley according to the state of the art. 10

In Fig. 1, 1 generally designates a food serving trolley, which comprises a chassis 2 with wheels 3. In the upper area, the food serving trolley has a trough 4 for accommodating a water bath in or over which the food can be kept warm. The trough 4 is

a foil heater 5 is used, whereby in Fig. 1 a foil heater 5 is only provided below the trough 4. In addition, foil heating elements arranged on the side of the trough 4 can be provided.

The foil heater 5 is glued to the trough 4. The foil heater 5 can be self-adhesive for this purpose. This direct connection between the foil heater 5 and the trough 4 ensures optimal heat transfer from the foil heater 5 to the trough 4, so that a

A heating arrangement can be selected that emits little heat radiation. In this way, the amount of heat that does not reach the trough 4 and is therefore to be regarded as power loss is reduced.

A thermal insulation 6 is provided beneath the foil heater 5, which can consist, for example, of foamed insulation material. A similar thermal insulation 6 is also provided around the trough 4. Insulation plates of the desired thickness can be used for this purpose in an inexpensive manner.

used and, if necessary, glued together.

A temperature sensor 7 is arranged inside the water bath of the trough 4, whereby an externally accessible control unit 8 interacts with this temperature sensor 7 and controls the temperature of the foil heater 5. The control unit 8

can include a controller and a display for pre-selecting or controlling the temperature achieved in the trough 4. Due to the relatively low temperature level inside the device achieved by the foil heating 5, it is possible to use electronic controllers for the control unit 8.

which are commercially available as series devices, can therefore be purchased inexpensively and are inexpensive because they allow ambient temperatures of up to 60°. The foil heating 5 used ensures that no higher temperatures can be reached outside the thermal insulation 6.

than 60° C.

With the help of the new heating system, energy savings of approx. 30% can be achieved compared to radiant heating in a typical operating situation in which

the food is first heated up and then kept warm for three hours.

In Fig. 2, part of a food serving trolley according to the state of the art is shown. Here, 4 also designates the trough in which a water bath is located. A heating element 9 is arranged at a distance below the trough 4, which reaches considerable temperatures and heats the trough 4 due to its radiant heat and the rising heat by means of convection. Below the heating element 9, a support for the heating element 9 is provided in the form of a sheet metal cassette 10, which has a mineral thermal insulation 11 at the bottom. The trough 4 is also thermally insulated on the sides with the help of such mineral insulation 11. An electrical supply line 12 for the energy supply of the heating element 11 is provided.

indicated schematically.

In a modification of the embodiment shown, the mobile nature of the food serving device can be dispensed with and it can be designed, for example, as a table device. When setting up such a food serving device

device on a table or a similar closed substructure the heat cannot be dissipated downwards or can only be dissipated with considerable restrictions, so that for the devices constructed as per Fig. 2 either a particularly strong insulation had to be provided on the bottom or

the use of such devices as table devices was prohibited. Thanks to the innovation, the food serving devices can now be used as table devices without any problems, as the energy that needs to be dissipated downwards is easily available. Furthermore, only a thin insulation layer is used in the base area of the device.

lation is required so that the height of the food serving device remains low and ensures easy operation.

The temperature sensor 7 can, in contrast to the ones used in the stand

capillary tube thermometers commonly used in technology can be designed as a purely electrical sensor, so that digital signal processing is made possible in a simple way and therefore the display of the temperature set in the water bath as well as the control of the heating power of the films

heating is possible in a simple and inexpensive way.

Claims (6)

t HARRFI ^: .« ^: ... ^: "&Agr;&idiagr;&Lgr;.*&Igr;&Ngr;&Tgr;5··&ngr;&idiagr;.-&Rgr;. HABBEL ^& n/^\OOUL EUROPEAN PATENT ATTORNEY PATENT ATTORNEYS DIPL.-INQ. LUTZ HABBEL PO Box 3429 - 48019 Münster DIPL.-QEOQR. PETER HABBEL TELEPHONE (0251) 535 780 ♦ FAX (0251) 531 996 OUR FILE: (please specify) H54/18422 Iu/Sc Muenster, 04.12.95 Schumacher, Heimut, Flamschen 41, 48653 Coesfeid 20 "Foil heated food container" Protection claims: 1. Food container, with a food-receiving Trough and with a heating element heating the trough, characterized in that the heating element consists of a foil heater which is arranged in heat-conducting contact with the trough. 2. Food container according to claim 1, characterized in that the heated areas of the food container are insulated from the ambient temperature by means of foamed insulating materials. 3. Food container according to claim 1 or 2, characterized in that a foil heater is arranged on the side of the trough. 4. Food container according to one of the preceding claims, characterized in that the trough (4) is designed to accommodate a water bath and to accommodate a food trough containing the food. 5. Food container according to claim 4, characterized net that the food container is designed to be movable in the form of a food serving trolley. 6. Food container according to claim 4 or 5, characterized by a sensor which determines the water temperature sensor which is effectively connected to a temperature indicator that can be read on the outside of the food container.