LU83219A1 - APPARATUS PARTICULARLY FOR HEATING LIQUID OR PASTY FOODS - Google Patents

Description

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The present invention relates to an apparatus particularly intended for heating liquid or pasty foods and in particular milk.

The invention relates in particular to an apparatus which makes it possible to heat water for the preparation of tea and coffee, or for reheating bottles and which can also be used to heat until the milk is boiling.

It is known that in the vicinity of boiling, a skin is formed on the surface of milk and other milk-based liquids which, when puncturing causes the milk to overflow, which results in the drawbacks well known to users.

There are known devices in the form of perforated lids which are placed on the milk and which make it possible to avoid overflow of the milk. However, these devices are impractical to use and they have the drawback of being suitable only for a very specific container.

The object of the present invention is to overcome the drawbacks of known embodiments by creating a heating device which prevents the milk from overflowing, which is very convenient to use and which can be used for heating and reheating other foodstuffs. particular, but not limited to the liquid or pasty state.

The apparatus covered by the invention comprises a container intended to contain the liquid to be heated, and means for heating the latter by direct contact with the container or the liquid.

According to the invention, this device is characterized v in that these means comprise means for heating the upper part of the food more than its lower part.

The Applicant has surprisingly found that when the aforementioned conditions are met, the formation of a skin on the surface of milk or of a milk-based liquid near its boiling point is avoided, so that the milk does not overflow. Without the invention being f% 2 linked to this explanation, it is likely that the temperature gradient: formed in milk, directed in the opposite direction to that which is formed when a container is heated from below, leads to destruction. of the skin as it is formed.

Thus, the milk heating container does not have any inconvenient auxiliary use device and can be used for other uses such as heating water to prepare coffee or tea.

'10 According to an advantageous version of the invention, the apparatus comprises one or more electrical heating resistors surrounding the upper part of the side wall of the container.

To allow a rapid rise in temperature, the apparatus preferably further comprises one or more electrical resistances arranged under the bottom of the container, means being provided for reducing the heating power of these resistors or for cutting their electrical supply to a temperature below the boiling point of the liquid food.

Thus, before the milk, for example, is boiled, heating is applied only in the upper part of the milk, which prevents skin formation.

Other features and advantages of the invention will become apparent in the description below.

In the appended drawings given by way of nonlimiting examples:,. Figure 1 is a longitudinal sectional view of an apparatus according to the invention; FIG. 2 is a curve showing the rise in temperature as a function of time during the heating carried out ”in the apparatus according to the invention.

In the embodiment of FIG. 1, the apparatus according to the invention comprises a container 1 intended to contain water, milk or any other food, in particular in the liquid state.

This container 1 made for example of aluminum is removably housed in an enclosure 3 made for example of plastic. This enclosure has an opening above the container 1, which is closed by a cover 3a.

Around the upper part of the side wall of the container 1 are arranged tubular electrical resistors 4, preferably sheathed in aluminum.

* “10 These are crimped into a ring 5 made of a material which is a good conductor of heat such as aluminum. This ring 5 has a frustoconical inner surface 6 in contact with the upper part of the frustoconical side wall of the container 1. This ring 5 and the resistors 4 are therefore located opposite the upper part 2a of the liquid to be heated 2.

In the embodiment shown, the device further comprises resistors 7 set in a sole 10 made of a material which is a good conductor of heat, for example aluminum-20 nium. The spring 11 disposed under this sole 10 elastically applies the latter against the bottom 8 of the container 1 which is favorable with respect to the heat exchange.

An adjustable thermostat or temperature limiter 9 is provided to reduce the heating power of the resistors 25 or to cut their electrical supply to a temperature below the boiling temperature of the liquid 2, in particular when the latter is milk. Another thermostat or temperature limiter or similar means is provided to cut off the electrical supply to the upper resistors 4 when the boiling temperature of the liquid 2 is reached.

^ We will now describe the operation of the device according to the invention.

The container 1 filled with milk is placed in the apparatus. Its bottom 8 bears against the heated sole 10

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4 and its frustoconical side wall is supported on the: frustoconical inner face 6 of the heating ring 5. The heating is started. At the start, the lower 7 and upper 4 resistors are supplied, the rise in temperature of the milk 2 is rapid (see curve in FIG. 2). Before boiling the milk, for example at 80 ° C., at time t ^ the thermostat or temperature limiter 9 cuts off the electrical supply to the lower resistors 7. The heating of the milk is continued until boiling by the only 10 upper resistors 4 The temperature rise rate is then slower until time t2 (boiling).

Experience shows this surprising result, that no skin forms on milk 2 near the boiling point. So the milk does not overflow. This result 15 results from the fact that between times t and t, the milk 2 is only heated in its upper part 2a and no longer in its lower part 2b.

= A comparable result can be obtained by heating the milk from room temperature only with the higher resistors 4. However, in this case the speed of temperature rise would be slower. The function of the lower resistors 7 is therefore limited * essentially to obtaining a sufficiently rapid rate of temperature rise in the period when the skin 25 is not likely to form.

At time t2, i.e. at the boiling point of milk 2, another thermostat or temperature limiter cuts off the electrical supply to the upper resistors 4.

For example, the upper resistors 4 30 can have a power of 1.8 KW, the lower resistors 7, 0.8 KW and the container 1 can have a volume of 1.5 liters.

Of course, the invention is not limited to the example which has just been described and numerous modifications can be made to it without departing from the scope of the invention.

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Thus the container could be cylindrical and include at its upper part a shoulder resting in the service position on the ring 5.

The container can also rest freely on the sole 10 and the spring 11 disposed under this sole can be adjusted so that the upper resistances 4 are located opposite the upper part 2a of the liquid 2 whatever the level of the latter in the container 1.

Furthermore, the heating ring 5 could be * 10 constituted by two elements movable laterally relative to the side wall of the container 1 and which can be brought into contact with this wall after the container has been placed. In this case the container can have any shape.

Of course, the apparatus according to the invention can be used to heat or reheat liquids other than milk. It can include for this purpose several specific containers. The device could also be used to heat bottles or jars of baby food.

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Claims (11)

1. Apparatus particularly intended for heating liquid or pasty foods and in particular milk, comprising a container (1) intended to contain the liquid (2) 5. heating, and means for heating the latter, by direct contact with the container or the liquid, characterized in that these means comprise means (4) for heating the upper part (2a) of the food more than its lower part (2b) - ". 2. Apparatus according to claim 1, character ized in that it comprises one or more electrical heating resistors (4) surrounding the upper part of the side wall of the container (1). 3. Apparatus according to claim 2, character-15 risë in that the or the resistors (4) are fixed in a ring (5) of good heat conductive material, this ring having an inner surface (6) in contact with the upper part of the side wall of the container (1). 4. Apparatus according to any one of the claims 2 or 3, characterized in that it further comprises one or more electrical resistors (7) arranged under the bottom (8) of the container (1), means (9) being provided to reduce the heating power of these resistors or to cut their electrical supply at a temperature below the boiling temperature of the liquid food (2). 5. Apparatus according to claim 4, characterized in that said resistance (s) (7) are fixed in a sole (10) made of a material which is good conductor of heat, means (11) being provided for Elastically apply this sole (10) against the bottom (8) of the container. 6. Apparatus according to any one of claims 4 or 5, characterized in that it comprises a thermostat or temperature limiter (9), sensitive to the temperature prevailing in the lower part (2b) of the food 7 * * liquid and arranged to control the reduction of the heating power of the resistors (7) or the cut of their electrical supply at a temperature below the boiling temperature of the liquid food (2) and 5 in this that means are provided for cutting off the electrical supply to the resistors (4) at the boiling point of the food (2). 7. Apparatus according to any one of claims 1 to 6, characterized in that the container (1) is removably mounted inside the apparatus. 8. Apparatus according to any one of claims 1 to 7, characterized in that the side wall of the container (1) has an at least partially truncated conical surface flared upwards and is supported in the service position on the inner surface (6) of complementary shape of the ring (5) good conductor of heat which maintains the resistance (s) (4). 9. Apparatus according to any one of claims 1 to 7, characterized in that the side wall of the container has at its upper part a shoulder resting in the operating position on the ring (5). 10. Apparatus according to claim 7, characterized in that the container (1) rests freely on the sole (10), the elastic means (11) arranged under this sole being adjusted so that the upper resistances (4) are opposite the upper part of the liquid (2) whatever the level of the latter in the container (1). ♦ 11. Apparatus according to any one of claims 3 to 10, characterized in that the ring (5) is constituted by two elements movable laterally with respect to the side wall of the container and capable of being brought in. contact with this wall after placing this container.