EP1091176A1

EP1091176A1 - Burner device for hobs of gas cookers

Info

Publication number: EP1091176A1
Application number: EP99830626A
Authority: EP
Inventors: Carlo Amati
Original assignee: Ac Di Amati Carlo & Csas
Current assignee: Ac Di Amati Carlo & Csas
Priority date: 1999-10-05
Filing date: 1999-10-05
Publication date: 2001-04-11

Abstract

A burner device for hobs of gas cookers comprises a holding and support body (2) having a housing seating for a radiating body (4), a plate-like element preferably made of pyroceram material (6) engaged in an upper portion of the holding and support body and having an extension substantially corresponding to that of the underlying ceramic body, means (7) for conveying the gasair mixture to the radiating body, and at least one exhaust opening (5b) for evacuation of the burnt gases formed in the holding and support body.

Description

The present invention relates to a burner device for hobs of gas cookers, of the type comprising a radiating body and means for conveying a combustible gas-air mixture to the ceramic radiating body.

It is known that in hobs of gas and/or electric cookers of the traditional type several, i.e. four or five, burners or rings are for example provided, each controlled by an adjustment knob of its own for gas flow regulation.

In addition, generally, traditional rings have different sizes so that the most convenient one of said rings can be selected depending on the bottom extension of the cooking pan, use of which is wished.

The drawbacks present in the above described rings are quite apparent: a poor thermal yield due to heat dissipation by the flame and the difficulty of exactly making the flame sizes match the bottom sizes of the container to be heated. Furthermore, heating by traditional gas rings is not very homogeneous and is typically concentrated on an annulus instead of being distributed over the whole bottom of the container to be heated.

In an attempt to improve yield of the food-cooking operation, i.e. to increase thermal yield of burners, in particular gas burners, also known is use of gas cookers comprising burner devices each provided with a ceramic radiating body made up of microalveolate ceramic material: the ceramic body is made white-hot by combustion of the gas that is caused to flow therethrough by appropriate conveying means.

In these gas cookers a plate of pyroceram material is provided to be disposed on the top of these ceramic-body burners, the sizes of said plate corresponding to the whole cooker hob and being adapted to form the rest surface of the food-cooking containers.

Exhaust of the burnt gases accumulated under the pyroceram plate is carried out for all burners through a common outlet disposed at the rear of the gas cooker hob.

The known art briefly described above has some important drawbacks.

In fact, first of all, under the rest surface made up of the pyroceram plate, only one front row consisting of two or three burners at most, provided with a ceramic body, can be disposed because a second backward row of burners would be impinged on by the flow of burnt gases from the first row directed towards the rear exhaust outlet and hence conditions provided for correct operation of these burners would be altered.

In addition, taking into account the above considerations, for one and the same overall extension of the hob, the hob surface where heat radiating points to be used for heating of the containers are present is reduced.

It is also to be pointed out that, since only two or three burners are provided, the extension of the radiating surface of the same must be necessarily suitable for use of containers of the greatest sizes to the bottoms of which said surface must correspond. Therefore, in case of use of containers having bottoms of reduced extension, an excess in the radiating surface occurs and consequently there is waste of heat with respect to true requirements of heat transmission.

Practically, the optimal utilization of hobs having burner devices provided with a ceramic body of known type is rather rigid, i.e. of reduced adaptability to the different situations usually occurring when heat is to be supplied to cooking vessels.

It is finally to be pointed out that since a hob in accordance with the above described known art greatly diverges from the conformation of traditional hobs, it cannot fall within the production lines of traditional hobs, but a specific planning and construction is required for it, which will bring about high production costs.

Under this situation, the technical task underlying the present invention is to conceive a burner device for hobs of gas cookers capable of substantially obviating the mentioned drawbacks.

Within the scope of this technical task, it is an important aim of the invention to provided a gas burner device that, in addition to achieving high yields typical of burners provided with a radiating ceramic body, also enables accomplishment of hobs with completely independent burners or rings, such distributed on the hob that they can meet all requirements of heat delivery and versatility of use.

It is a further aim of the invention to provided a burner device of high yield adapted to replace, with limited adaptation operations, a gas burner or a radiating electric plate in a hob of the traditional type.

The technical task mentioned and the aims specified are substantially achieved by a burner device for hobs of gas cookers which is characterized in that it comprises a holding and support body having a housing seating for receiving said radiating ceramic body, and a plate-like element associated with an upper portion of said holding and support body to define a rest surface extending above the radiating ceramic body.

Description of a preferred embodiment of a burner device for hobs of gas cookers in accordance with the invention is now given hereinafter by way of non-limiting example, with reference to the accompanying drawings, in which:

Fig. 1 is a top view of a burner device in accordance with the invention;
Fig. 2 shows a section taken along plane II-II in Fig. 1;
Fig. 3 is a section taken along plane III-III in Fig. 1;
Fig. 4 is an exploded perspective view of the burner device shown in Fig. 1;
Fig. 5 is a partial plan view of a hob provided with four burners or rings in accordance with the invention.

With reference to the drawings, the burner device for hobs of gas cookers is generally identified by reference numeral 1.

It comprises a preferably cup-shaped holding and support body 2 provided with a side wall of substantially cylindrical extension; the body 2 at a central region thereof has a housing seating 3 for a radiating body 4, preferably consisting of a microalveolate ceramic radiating element, structure and operation of which are of conventional type and known per se. Alternatively, the radiating body 4 may consist of a substantially laminated or flat element made of metallic or synthetic fibres. The metallic or synthetic fibres may form a laminated-texture fabric or mat depending on requirements.

It is to be noted that the holding body is such shaped and sized that it can completely house the radiating body inside it.

The radiating body shape will be the same as the shape to be given to the ring, a circular shape for example depending on requirements, and said radiating body will be housed in a holding body conforming to it in shape. More specifically, the holding body 2 has a base from which a side wall perimetrically surrounding the ceramic body emerges.

The holding and support body 2 further has an upper portion 5 comprising an annular seating 5a adapted to house and engage a preferably plate-like rest element 6; advantageously and preferably the rest element may be made of pyroceram; element 6 defines a rest surface for a food-cooking container that can be disposed over the radiating body 4.

The extension and shape of the rest element 6 substantially correspond to those of the underlying radiating body 4 and said element closes the burner device 1 on top. In addition, the upper portion 5 comprises at least one opening 5b for burnt gas evacuation, which is disposed between the annular seating 5a and housing seating 3 for the radiating body 4. It is to be pointed out that opening 5b extends above the ideal plane defined by the upper surface of the radiating body 4 and below the rest element 6 or flush therewith.

Preferably provision is made for several slit-like openings 5b disposed under the plate-like element 6 and extending in the upper portion of the side wall of the holding body 2, above the lying plane of the radiating body.

In more detail, it should be pointed out that the distance between the lying plane of the ceramic body and the lying plane of the plate-like rest element is selected for the purpose of optimizing combustion and outflow of the burnt gases. In particular, the distance between the upper surface 4b of the radiating body 4 and the lower surface 6a of the rest element 6 is included between 5 and 25 mm and preferably between 10 and 20 mm.

The gas-air mixture is sent to the lower face 4a of the radiating body 4 by conveying means 7 formed in a lower portion 8 of the holding and support body 2 itself. More specifically, the conveying means 7 preferably comprises at least two independent mixing chambers 7a, 7b, disposed below the ceramic body 4 and each adapted to convey the gaseous fluid to a corresponding portion of said ceramic body.

For instance, the radiating body 4 has a substantially annulus-like plan conformation and the mixing chambers 7a, 7b have annular concentric shapes each corresponding to an outer portion and an inner portion respectively of the annulus-like shape of the radiating body 4.

In order to ensure fluid-tightness to the

mixing chambers

7, 7a, 7b, annular seals 9 are interposed between the upper edge of said chambers and the lower face 4a of the radiating body 4 to ensure permanence of the gaseous fluid in the respective mixing chambers.

Finally, a control and regulation unit 10 possibly also provided with electronic components is connected with each burner 1 and it is adapted to offer the user the possibility of an independent control of the gas flow in the mixing chamber or

chambers

7, 7a, 7b.

Practically, a user can choose, depending on requirements, whether he/she wishes to have at his/her disposal a narrow radiating surface corresponding to the inner mixing chamber 7b, a larger radiating surface corresponding to the whole annulus defined by the radiating body 4, or even a radiating surface only corresponding to the outer mixing chamber 7a.

Obviously if there are more than two mixing chambers, the user can choose among a greater number of radiating surfaces of differentiated extensions for each burner device.

Due to the independent regulation of the gas flow rate in each mixing chamber 7a, 7b, the radiated thermal flow can be also varied in each corresponding region of the radiating body; i.e. it is possible, for instance, to have a hotter radiating surface in the outer band than in the inner band or vice versa, to meet particular cooking requirements.

Shown in Fig. 5 is a hob 11 provided with four burners or rings of at least partly different diametrical sizes, each of which consists of a burner device 1 corresponding to the above description.

The hob thus made enables many advantages to be achieved, resulting from the particular features of each burner device.

In fact, first of all the device is very versatile and of high yield, because the user can manage each burner device in an independent manner, so that the radiating surfaces are as much as possible close to the bottom sizes of the containers to be heated.

It will be recognized in particular that the hob surface can house several rows of burner devices, like in traditional cookers, because each burner has opening for exhaust of its own burnt gases: thus these gases neither interfere with the other burners nor can be stored, as in the known art, under a single pyroceram plate covering the whole hob. In addition, a hob provided with burners devices in accordance with the invention can be easily obtained by replacement of the radiating gas burners or electric plates present in traditional cookers and consequently specific planning and constructions are not required.

It will be finally appreciated that the burner devices having a radiating body can be shaped following any conformation, instead of having a traditional circular form, for the purpose of meeting the most varying operating and/or aesthetic requirements.

Claims

A burner device for hobs of gas cookers of the type comprising a radiating body (4) and means (7) for conveying a combustible gas-air mixture to the radiating body (4), characterized in that it comprises:

a holding and support body (2) having a housing seating (3) for receiving said radiating body (4), and a rest element (6) associated with an upper portion (5) of said holding and support body (2) to define a rest surface extending above said radiating body (4).
A device as claimed in claim 1, characterized in that said holding and support body (2) houses the radiating body (4) inside it and has a side wall perimetrically surrounding the radiating body and conforming to it in shape.
A device as claimed in anyone of the preceding claims, characterized in that said rest element is preferably of plate-like conformation (6) and has a radial extension substantially corresponding to that of the underlying radiating body (4).
A device as claimed in anyone of the preceding claims, characterized in that said upper portion (5) of the holding and support body (2) has at least one opening (5b) for exhaust of burnt gases.
A device as claimed in anyone of the preceding claims, characterized in that said conveying means (7) comprises at least one mixing chamber defined by a lower portion (8) of said holding body (2) and extending below said radiating body (4).
A device as claimed in claim 5, characterized in that said conveying means (7) of the gas-air mixture comprises at least two independent mixing chambers (7a, 7b) disposed below said radiating body (4) and each adapted to convey the gaseous fluid towards a corresponding portion of the radiating body.
A device as claimed in claim 6, characterized in that said holding and support body (2) comprises a lower portion (8) defining said at least two independent mixing chambers (7a, 7b).
A device as claimed in claims 6 or 7, characterized in that said radiating body (4) in plan view substantially has an annulus-like conformation and said at least two mixing chambers (7a, 7b) have concentric annular shapes each corresponding to an outer portion and an inner portion respectively of said annulus.
A device as claimed in claim 5 or claim 6, characterized in that it comprises annular seals (9) interposed between the lower face (4a) of said radiating body (4) and the upper edge of said mixing chamber or concentric mixing chambers (7a, 7b).
A device as claimed in claim and as claimed in claim 6, characterized in that it comprises a control and regulation unit (10) adapted to carry out an independent control of the gas flow in each of said mixing chambers (7, 7a, 7b).
A device as claimed in anyone of the preceding claims, characterized in that said rest element (6) consists of pyroceram or metallic material.
A device as claimed in anyone of the preceding claims, characterized in that said radiating body (4) is a ceramic body, or a substantially laminated or flat body made up of a fabric or mat of metallic and/or synthetic fibres.
A device as claimed in anyone of the preceding claims, characterized in that said rest element (6) has a lower surface (6a) placed at a distance ranging from 5 to 25 mm from an upper surface (4b) of the radiating body.
A device as claimed in claim 13, characterized in that said distance between the lower surface (6a) of the rest element (6) and upper surface (4b) of the radiating body is preferably included between 10 and 20 mm.
A hob for a gas cooker, characterized in that it comprises a plurality of independent burner devices (1), each in accordance with claim 1 and operation means adapted to manage each said burner (1) in an independent manner.
A hob as claimed in claim 15, characterized in that it comprises a plurality of exhaust regions (5b) for the burnt gasses, each corresponding to one said burner device (1).
A hob as claimed in claim 15, characterized in that said conveying means (7) for the gas-air mixture comprises at least one or preferably two independent mixing chambers (7a, 7b) for each said burner device (1), said chambers being disposed below the respective radiating body (4) and being each adapted to convey the gaseous fluid to a corresponding portion of the radiating body (4), and in that said operation means comprises a control and regulation unit for each burner, which unit is adapted to control the gas flow in each said mixing chamber (7, 7a, 7b) in an independent manner.
A hob as claimed in anyone of claims 15 to 17, characterized in that said burner devices are arranged in several rows disposed in side by side relationship on the hob.