COOLING AND HEATING PLATE

Abstract

A cooling and heating plate, in particular for serving food and beverages, is connected to a cooling unit and an electrical heating device, preferably a silicone panel heater, is also provided on the under side of the plate. The plate is a multilayered plate having an upper plate, preferably of chrome nickel steel, and an aluminum plate situated thereunder. At least one steel pipe, which is preferably seamless with serpentine curves, having a compressive strength of at least 50 bar is integrally cast in the aluminum plate. As a result, carbon dioxide can also be used as a coolant. Fastening elements can also be integrally cast in the aluminum plate.

Claims

1. A cooling and heating plate, in particular for the presentation of food and beverages, in which the plate is connected to a cooling unit and has an electrical heating device on its lower side, wherein the plate is designed as a multilayered plate having an upper plate, preferably consisting of chromium-nickel steel, and, situated therebelow, an aluminum plate having coolant ducts, wherein at least one steel pipe having a compressive strength of at least 50 bar is integrally cast in the aluminum plate to form the coolant ducts.

2. The cooling and heating plate according to claim 1, wherein the steel pipe is bent in a meandering shape.

3. The cooling and heating plate according to claim 1, wherein fastening elements are also integrally cast in the aluminum plate.

4. The cooling and heating plate according to claim 1, wherein the steel pipe is seamless.

5. The cooling and heating plate according to claim 1, wherein the aluminum plate has a thickness which is approximately twice as large as the outside diameter of the steel pipe.

6. The cooling and heating plate according to claim 1, wherein the electrical heating device is a silicone panel heater which is fitted on the lower side of the aluminum plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be explained in more detail with reference to the appended drawing, in which FIG. 1 shows a vertical section through a cooling and heating plate according to the invention; and

[0015] FIG. 2 shows a horizontal section through the same cooling and heating plate.

BEST WAY OF IMPLEMENTING THE INVENTION

[0016] The cooling and heating plate is a multilayered plate 11 consisting of an aluminum plate 13 and an upper plate 12. The upper plate 12 bears the beverages to be heated or to be cooled and must therefore, on the one hand, consist of a food-safe material and, on the other hand, must have a sound appearance over years. A preferred material for the upper plate 12 is chromium-nickel steel.

[0017] A steel pipe 14 bent in a meandering shape is integrally cast in the aluminum plate 13. This steel pipe 14 has a compressive strength of at least 50 bar and can therefore also withstand the pressures which are necessary for refrigerating machines having carbon dioxide as refrigerant. Since the steel pipe 14 is integrally cast in the aluminum, the heat transfer resistance between the steel pipe 14 and the aluminum plate 13 is low. Between the refrigerant (e.g. carbon dioxide) and the aluminum plate 13 there is, of course, additionally the heat resistance of the steel pipe 14, which should therefore be as thin as possible. If use is made of a seamless steel pipe 14, it is possible to manage with wall thicknesses of at most 1 mm without compromising the necessary compressive strength.

[0018] Fastening elements 15 are also integrally cast in the aluminum plate 13. An electrical silicone panel heater 16 is mounted on the lower side of the aluminum plate 13. For heating, this silicone panel heater is switched on, in which case the cooling unit is, of course, switched off. The coolant can remain in the steel pipe 14. Although carbon dioxide then exceeds the critical temperature, the steel pipe 14 withstands the resultant pressures.

[0019] For temperature measurement (both during heating and during cooling), a Pt100 temperature sensor can be provided in a conventional manner, and a suitable controller is, for example, the controller ST121-KD1TA.03FS from STRK-TRONIC.

[0020] This cooling and heating plate makes it possible, during cooling, to achieve an optimum temperature transfer down to 30 C. The temperature of 30 C. serves for the production of ice cream, directly before the eyes of the consumer. During heating, a temperature of up to 140 C. can be achieved, with the result that food can be kept sufficiently warm. The bottom of the cooling and heating plate is insulated to suit the requirements

[0021] The cooling and heating plate can be operated with carbon dioxide, with the result that the otherwise customary greenhouse gases can be avoided. Of course, however, it can also be operated with all conventional refrigerants, thus also being suitable as a replacement part for existing systems. Isobutane as refrigerant is best suited for a cooling unit which is mounted directly in the cooling and heating plate and which has to be correspondingly compact.

[0022] The upper plate 12 and the aluminum plate 13 are preferably adhesively bonded to one another with an adhesive having good heat conductivity. If they are connected to one another by rolling, there is the risk that the steel pipe 14 is deformed in the process, resulting in cross-sectional narrowings.