GB2226231A - Steam electric chafer - Google Patents

Abstract

A steam electric chafer for preparing soup and boiling meat instantly comprises a chafer cover (1), a chafer body (3), a base (6), and a steam generator (11). The steam generator (11) consists of a steam cover (2) and an electric heater (5) covered by the steam cover (2). The steam cover (2) has a plurality of orifices (10) to let the water inside and outside the steam cover (2) interflow. When the electric chafer is working, the steam and water in the working area, i.e. the area outside steam cover (2), produce a heat exchanging mode of thermal convection which imparts a large thermal inertia with a high and uniformly distributed temperature to the water in the working area. <IMAGE>

Description

"Steam Electric Chafer" FIELD OF THE INVENTION The present invention relates to a cooling utensil and, particularly to an electric chafer for cooking soup and boiling meat, using electricity as a source of heating.

BACKGROUND OF THE INVENTION The structure of electric chafers produced domestically and abroad up until now is similar to that of an electric rice pot or electric kettle.

These kinds of chafers have an electric heater by which the water or soup inside the chafer is heated. In consideration of economy and portability powerful electric heaters are not used in chafers.

Thus, in the use of heating electric chafers which work by conduction, people usually experience the phenomena of so called "fire not being hard" enough (i.e. when meat or vegetables are put into the water or soup, instant conversion from raw to cooked does not occur). However, the feature of having a "hard fire" is one of the essential requirements of chafer use.

SU?lMARY OF THE INVENTION An object of the present invention is to provide an electric chafer which solves the above-mentioned problem of "fire not being hard" enough, by accelerating the heat convection of the water or soup inside the chafer.

Another object of the present invention is to provide an electric chafer with relatively high and uniformly distributed water or soup temperature in the working area of the chafer.

According to the invention there is provided a steam electric chafer comprising a chafer cover, a chafer body and a base, characterised in the provision of a steam generator located at the central portion of the lower part of said chafer body.

Advantageously the steam generator comprises a steam cover and an electric heater covered by the steam cover. The steam cover is preferably cylindrical having a plurality of orifices distributed in its lower portion. Various electric heating materials can be adopted to constitute the electric heater, such as heating alloys or heating membranes.

Other heating methods such as electric heaters utilizing electromagnetic energy are also adaptive.

When the electric chafer according to the present invention is being used, the water inside the steam cover is heated by the electric heater, and the heated water and steam are rapidly jetted out through the orifices to heat the water in the working area is essentially by thermal convection.

In the case of equal power consumptions, t-he advantages of the chafer according to the present invention as compared with that of the prior art are that when it is being used, the temperature drop of the local water caused by dipping vegetables or meat therein can be replenished promptly by the rapidly flowing water and steam, which appears as high heat inertia. Similarly, due to the rapid flow of the heating water and steam, the temperature of the water in the working area is relatively high and distributed uniformly.

The present invention will now be explained by way of example with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig 1 is a partial sectional view of an embodiment of a steam electric chafer according to the present invention; Fig 2 is a perspective view of the electric heater of Fig 1; Fig 3 is a partial sectional view of another embodiment of the present invention; Fig 4 is a partial sectional view of the embodiment 3 showin in Fig 3; and Fig 5 illustrates an electric circuit for use with the embodiment of Fig 4.

BEST MODES OF CARRYING OUT THE INVENTION It should be understood that the following description serves only to illustrative preferred details of the present invention. Therefore, the present invention is not to be limited by the embodiments illustrated, as faL as those modications and improvements to the embodiments described would be obvious to the person skilled in the art.

As shown in Fig 1 the electric chafer comprises a chafer cover (1), a chafer body (3), a base (6), and a steam generator (ill) which further comprises a steam cover (2) and an electric heater (5).

The chafer cover (1), steam cover (2), chafer body (3), and base (6) are made of ceramic by sintering formation or metallic materials. When ceramic is used, the surface of the chafer may be decorated in relief.

Chafer cover (1) is shaped like a conventioanl charcoal chafer. Base (6) and chafer body (3) are constructed in a uniform or separated form, mounted with a phenolic plastic socket (7). Fixing and lead in orifices are provided for mounting an electric heater (5) in chafer body (3). Steam cover (2) is made of the same material as the chafer body and in a cylindrical shape, similar to the shape of the fire tube of a conventional charcoal chafer, around the circumference in the lower portion of which, three rows of orifices with dimeter 1.5mum - 5mm are drilled in uniform dlstribution, the location of the upper row being arranged so that it is submerged beneath the water surface in actual use.

An electric heater (5) is compressed and sintered of high temperature resistance ceramic, with a circular lower surface having 4 fixing screw orifices, the upper part of which appears to be 4 crossed hollow electric heating plates (4) as shown in Fig 2.

A heating alloy is wound on the micra sheets and inserted into the hollow plates after insulation, then sealed with silicon rubber after being filled with modified magnesium oxide powder. The power leads of the 4 electric heating plates are all connected to a temperature adjusting switch (8).

The electric heating plates may be connected in series or in parallel by the adjusting switch (8) to change the temperature of the chafer. Socket (7) further comprises a power indicator lamp to indicate the on and off state of the device.

When using the above-mentioned temperature adjustable steam electric chafer, the chafer body (3) is first filled with water, the water surface should be kept a little higher than the height of orifices (10), then the temperature adjusting switch (8) is pressed.

If it is set on the high temperature position, the electric heaters (5) are connected to the power source in parallel. When the water in the chafer is boiling, the temperature adjusting switch (8) is pressed to the low temperature position to cause the electric heaters (5) to be connected to power source in series to reduce power consumption.

When the electric chafer is working, the water flowing into the steam generator (11) via orifices (10) is heated quickly by electric heater (5), and as the temperature reaches a certain valueS the water inside the steam cover (2) boils and the upper portion of steam cover (2) jetting out toward the water outside steam cover (2) (in working area) through orifices (10) at very high speed, while the water at relatively low temperature outside the steam cover (2), i.e. in the working area, flows into the steam cover (2) through orifices (10). This form of heat convection is the essential mode of heat exchange of the electric chafer according to the present invention. There is a notable distinction between the effect achieved between this working mode - heat exchange by convection, and the working mode - heat exchange by conduction of the conventional chafers or the prior art. Since the steam and water inside the steam cover (2) jet out with very high speed, the temperature drops and the heat consumption of the water in the working area due to the dipping of vegetables and meat can be replenished timely by the heat from the steam and water jetted out with high speed, thus presenting the effect of "fire being hard".

In addition, the water temperature in the working area remains high and uniformly distributed due to the rapidly jetted steam and water. The working mode of the electric chafer according to the present invention is called a "steam jetting working mode", and the structure to achieve the effect of this steam jetting is called a "steam jetting structure".

Fig 3 is a partial sectional view of a further embodiment of the steam electric chafer according to the present invention. The chafer cover (1) and chafer body (3) of this embodiment is formed with materials which may readily be coated with porcelain enamel.

The central part of the chafer body (3) may be made in convex, concave, flat, etc. shapes for housing the electric heater (8). After the internal and external surfaces of chafer body (3) have been coated with porcelain enamel, the internal surface of the electric heaters (5) are then coated with conductive films (12) and the two power leads are directly connected to power socket (7).

Steam cover (2) is also made of ceramic in the shape of a conical tube, and orifices (10) in the bottom and mid circumference walls have slots with width 3mm and lengh 35mm. The highest location of the slots may be under the water surface in chafer body (3) in use, and base (6) may be made of phenolic plastics. The conditions of use of this embodiment are similar to that of the embodiment of Fig 2.

Fig 4 is a partial sectional view of the embodiment of Fig 3. It is a high frequency electromagetic steam chafer.

In Fig 4 the chafer cover (1) and chafer body (3) of the electric chafer is formed by sintered ceramic. In the central portion at the bottom of chafer body (3) an electric heater (5) is connected by sealing, which comprises a hollow cylindrical tube housing (14) made of cast-iron and coated with porcelain enamel, a high frequency coil (13), and a high frequency coil jacket (15).

The high frequency coil is also formed cylinderally and covered with a jacket (15) of high strength glass ceramic which is fixed to the base (6) as an integral construction. The high frequency generator and other circuits (16) are mounted onto the base (6) as an integrated part. The principle of electricity of the high frequency eletromagnetic chafer is basically the same as that of the high frequency electromagnetic stove of the prior art. For example, the circuit in UF-120 stove produced by SONY Corp.

in Japan is adaptive, which is illustrated in Fig 5.

The distinction between the high frequency electromagnetic steam electric chafer of Fig 3 and other embodiments of the steam electric chafer according to the present invention, is that the heat from the electric heater (5) is by magnetic energy conversion on the electric heater housing (14), while the magnetic energy is provided by the high frequency coil (16) in which high frequency current flows.

In addition, the electric heater housing (14) and high frequency coil (13) can be fixed on chafer body (3) and base (6) respectively, thus enabling the chafer body (3) and base (6) to be separated freely, and the electric chafer to be cleaned after use. The structure of steam cover (2) can be selected from either of the above two embodiments.

Claims (7)

1. A steam electric chafer, comprising a chafer cover, a chafer body and a base, characterised in the provision of a steam generator located at the central portion of the lower part of said chafer body.

2. A chafer as claimed in claim 1 wherein said steam generator further comprises a steam cover and an electric heater covered by said steam cover.

3. A chafer as claimed in claim 2 wherein said steam cover is a cylindrical tube steam cover, with a plurality of orifices in its lower part.

4. A chafer as claimed in claim 2 wherein said electric heater further comprises at least one electric heating plate having an electric heating material.

5. A chafer as claimed in claim 2 wherein said electric heater is curvilinear and coated with an electric heating membrane.

6. A chafer as claimed in claim 2, wherein said electric heater is an electric heater working by high frequency electromagnetic heating, and formed of a cylindrical housing and a high frequency coil inside said cylindrical housing.

7. A cooking utensil substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

7. A chafer as claimed in claim 6 wherein said electric heater has a high frequency coil jacket for protecting and covering said high frequency coil.

8. A cooking utensil comprising a cooking compartment and characterised in the provision of a steam generator within the cooking compartment, and means for passing steam from said generator to the interior of said cooking compartment.

9. A cooking utensil substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Amendments to the claims have been filed as follows

1. A steam electric chafer, comprising a chafer cover, a chafer body, a base and a steam generator located at the central portion of the lower part of said chafer body, said generator composed of a steam cover and an electric heater covered by steam cover, and said steam cover being a cylindrical tube steam cover with a plurality of orifices in its lower part.

2. A chafer as claimed in claim 1 wherein said electric heater further comprises at least one electric heating plate having an electric heating material.

3. A chafer as claimed in claim wherein said electric heater is curvilinear and coated with an electric heating membrane.

4 . A chafer as claimed in claim, wherein said electric heater is an electric heater working by high frequency electromagnetic heating, and formed of a cylindrical housing and a high frequency coil inside said cylindrical housing.

5 . A chafer as claimed in claim4 wherein said electric heater has a high frequency coil jacket for protecting and covering said high frequency coil.

6. A cooking utensil comprising a cooking compartment and characterised in the provision of a steam generator within the cooking compartment, and means for passing steam from said generator to the interior oE said cooking compartment.