GB2325132A - A steam heat transfer oven with supplementary induction heater - Google Patents

Abstract

In a steam heat transfer oven, supplementary "dry" heat is obtained by providing induction heating energy which generates eddy currents and hence local heat in the baking tin or on the baking plate supporting the food. Corrosion is avoided, and precise dosage of supplementary heat is obtained. The induction heater may be parked in a cavity in a wall of the oven.

Description

An induction heating steam oven.

The invention relates to an oven using steam for the transfer of heat to the food. Such ovens are highly efficient due to the high heat of evaporation of water, and furthermore their functionality is great in that the surface of many types of food does not lose humidity in the process. However, in order to obtain a faster cooking or baking or to obtain a lower moisture content in certain parts of the food, it may be desired to apply additional heat without simultaneously adding moisture.

A simple method for this is to provide a baking sheet with a dedicated heating element which heats a baking tin from below. This has the considerable disadvantage that the high humidity creates corrosion at the junction between dissimilar materials, such as between the leads to the heating element and the heating element wire, between the leads and a film heating element, or even plug and socket in case the connection is pluggable.

It is the purpose of the invention to provide a supplementary supply of heat which avoids the disadvantages mentioned. This is obtained in that an induction heating unit is placed adjacent to the baking tin and/or the baking sheet in order to generate eddy currents therein. In this manner, the induction heating element transfers inductive energy to the ferromagnetic elements baking tin and baking sheet which in turn heat the contents without further condensation of water vapour. The electrical connections to an induction heating element may be completely sealed, and the high frequency is not conducive to galvanic corrosion.

Furthermore, the thermal time constant of e.-g. just a baking tin is negligible which means that a precise doseage of supplementary heat may be obtained.

In an advantageous embodiment, the induction heating unit may be raised from a well in the bottom of the oven cavity when needed for heating food. This means that the oven may function as an ordinary steam oven for all tasks not requiring supplementary heat, because there are no interfering parts, and only in case this supplementary heat is required will the induction heating unit appear from its well. Generally the induction heating unit will be horizontal in use, and it is attached to an arm operated by means of a small electric motor.

It will be understood that without detracting from the inventive idea behind this embodiment, the induction heating unit may equally be swung sideways into a deep cavity in a side wall of the oven cavity or turned vertically through 90 degrees on a swivel arm before entering in a vertical orientation into a less deep cavity in the side of the oven cavity. Again, the actual manipulation of the induction heating unit occurs via a small electric motor placed totally outside the moisture-ridden oven cavity.

Claims (2)

PATENT CLAIMS

1. An oven with a baking tin and/or baking sheet using steam for the transfer of heat to the food and comprising a supplementary source of heat, c h a r a c t e r i s e d i n that an induction heating unit is disposed adjacent to the baking tin and/or the baking sheet in order to generate eddy currents therein.

2. An oven according to claim 1, c h a r a c t e r i s e d i n that the induction heating unit may be raised from a well in the bottom of the oven cavity when needed for providing supplementary heat to the food.