Gas oven

A gas oven comprises an oven space, having a bottom baking surface, two side walls rising up on opposite sides of the baking surface and at least one top wall facing the baking surface, burner means configured to raise the temperature of the oven space and a control unit associated with the burner means and configured to drive them as a function of a command given by a user to determine a preset temperature inside the oven space. The burner means comprise at least a first radiating element and a second radiating element which are independent of one another and which are configured to vary the temperature at the baking surface and at the top wall, respectively, and the control unit comprises at least a first drive module and a second drive module associated with the first radiating element and with the second radiating element, respectively, in order to control the first radiating element and the second radiating element independently of one another.

BACKGROUND OF THE INVENTION

This invention relates to a gas oven, of the type used to bake food products, preferably a gas oven used to bake a multiplicity of products but especially pizza, focaccia, pita, tortillas, piadina, bruschetta, crostini and the like.

Thus, the invention is applicable in particular in the food industry and in catering, both traditional and industrial (or for canteen services).

Gas ovens known in the prior art fall broadly into two categories, those equipped with blown air burners and those equipped with atmospheric burners (or air suction burners).

This invention addresses in particular burners of the second category but without excluding possible and advantageous use also in ovens equipped with blown air burners.

Gas ovens with atmospheric burners known up to now come in a multiplicity of forms, substantially all having in common an oven space, delimited at the bottom by a baking surface (either fixed or mobile) and a combustion chamber, usually located under the baking surface in order to heat it.

In order to distribute the heat inside the oven space more uniformly, one or more ducts extending from the burners towards the top of the oven space have in some cases been introduced to allow the floor (that is, the zone proximal to the baking surface) and the ceiling (that is, the zone distal from the baking surface) of the oven space to be heated in the same way.

This has certainly considerably improved heat distribution and product baking uniformity. It has not, however, solved another problem which gas ovens, especially those with atmospheric burners, have always suffered from.

In effect, although baking uniformity is in many cases an important goal to be accomplished, it is not desirable for all types of baked food products which, in some cases, may require the product base (“moister”) to be baked at a different temperature from the product top (crispier or more delicate).

Disadvantageously, all the solutions which have been proposed up to now do not solve this problem because the heat recirculation ducts do not allow regulating the temperature of the gas flowing through them.

The aim of this invention is to provide a gas oven capable of overcoming the above mentioned disadvantages of the prior art.

More precisely, the aim of this invention is to provide a gas oven, of the type used to bake food products and capable of guaranteeing optimum baking efficiency for different types of products.

A further aim of the invention is to provide a gas oven used to bake food products and which is high in performance and low in production costs.

SUMMARY OF THE INVENTION

These aims are achieved by a gas oven having the features set out in one or more of the appended claims and, more specifically, which comprises: an oven space with a bottom baking surface, two side walls rising up on opposite sides of the baking surface and at least one top wall facing the baking surface; burner means configured to raise the temperature of the oven space; and a control unit associated with the burner means and configured to drive them as a function of a command given by a user to determine a preset temperature inside the oven space.

According to the invention, the burner means comprise at least a first radiating element and a second radiating element which are independent of one another and which are configured to vary the temperature at the baking surface and at the top wall, respectively. In light of this, the control unit comprises at least a first drive module and a second drive module associated with the first radiating element and with the second radiating element, respectively, in order to control the radiating elements independently of one another.

In other words, the first drive module is connected to the first radiating element and the second drive module is connected to the second radiating element in order to vary/regulate the temperature in the proximity of the baking surface (floor) and of the top wall (ceiling) independently of one another.

Advantageously, that way, a user has the possibility of setting different temperatures for the two zones of the oven space, thereby optimizing baking efficiency for a wide range of food products, whether the products need to be baked uniformly or require different and, if necessary, changing, baking temperatures as a function of zone.

In this regard, it should be noted that the oven comprises at least one pair of temperature sensors (first and second) whose function is to measure the temperature in the proximity of the baking surface (floor) and of the top wall (ceiling) respectively.

Each of the temperature sensors is thus connected to a respective second drive module of the control unit to provide the latter with a signal representing the measured temperature

Thus, the first temperature sensor is connected to (associated with) the first drive module, whilst the second sensor is connected to (associated with) the second drive module.

Each drive module is thus configured to drive the respective radiating element as a function of the temperature signal provided by the respective temperature sensor.

It should be noted that the drive modules might be distinct processors or simply different modules of the same processing unit.

In order to allow the user to easily check and control the temperature, the oven is also equipped with an interface panel associated with the control unit and having at least a first and a second control element which are associated with the first and the second drive module, respectively, and which can be accessed (or operated on) by the user to set the required temperature of the baking surface (floor) and top wall (ceiling).

The interface panel is also preferably equipped with display means (analog or digital) for each control element.

The display means are configured to show the user both the actual temperature measured by the temperature sensor in each zone of the oven (ceiling and floor) and the set temperature.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the accompanying drawings, the numeral1denotes a gas oven, preferably one used to bake food products, according to this invention.

The gas oven1is thus of the type used to bake food products, that is, configured to treat and bake food products such as, for example, pizza, focaccia, pita, tortillas, piadina, bruschetta, crostini and the like.

The oven according to the invention, however, may also be used to bake meat or other products.

For baking purposes, the oven1comprises an oven space2having a bottom baking surface3, two side walls4and at least one top wall5.

It should be noted that the bottom zone “P” of the oven space, that is, the zone proximal to the baking surface3will hereinafter be referred to as “floor”, whilst the top zone “C” of the oven space, that is the zone distal from the baking surface3, will hereinafter be referred to as “ceiling”.

The baking surface3then has an upper side3a, inside the oven space2, and an underside3b, opposite to the upper side3aand facing away from the oven space2.

The baking surface3preferably comprises at least one layer made of a material which is resistant to prolonged exposure to high temperatures (without, for example, reacting chemically with the other materials it comes into contact with.

In the embodiment illustrated, this layer is made from one or more flat hollow tiles7of refractory material. Alternatively, other suitable materials may be used.

It should be noted that the baking surface3may be fixed or mobile, depending on the type of oven.

In the embodiment illustrated, the baking surface3is mobile. More precisely, the baking surface3is defined by a conveyor belt6movable along its main direction of extension “A” and positioned to move across the oven space2.

More precisely, each portion of the conveyor belt6is movable from a first stretch6a, where the products to be baked are placed on it, to a second stretch6b, where the baked products are withdrawn, passing by a third, baking stretch6clocated inside the oven space2to define the baking surface3.

It should be noted that the conveyor belt6is preferably equipped with a plurality of the above mentioned hollow flat tiles7of refractory material.

Alternatively, the baking surface3might be movable in rotation. In this embodiment (not illustrated), the baking surface is defined by a turntable which rotates about its axis of rotation.

Further, in simplified embodiments, the baking surface3is fixed, that is to say, without any means for the movement thereof. In such an embodiment the oven space has three side walls and a front door for opening and closing it.

In order to heat the oven space2, the oven1comprises burner means8(gas) configured to raise the temperature of the oven space2and a control unit9associated with the burner means8and configured to drive them as a function of a command given by a user to determine a preset temperature inside the oven space2

According to the invention, the burner means8comprise at least a first radiating element10and a second radiating element11which are independent of one another and which are configured to vary the temperature at the baking surface3and at the top wall5, respectively.

In this regard, the control unit9comprises at least a first drive module9aand a second drive module9bassociated with the first radiating element10and with the second radiating element11, respectively, in order to control them independently of one another

Advantageously, it is thus easy to obtain differentiated adjustments of the temperatures at the floor “P” and ceiling “C” of the oven space2, so as to optimize the baking process for numerous types of products, whatever type of baking is required

The control unit9is preferably defined by an electronic card equipped with a processor.

Preferably, the control unit9comprises two electronic cards, each defining a respective drive module9a,9b.

More precisely, the oven1comprises at least a first temperature sensor13and a second temperature sensor14.

The temperature sensors13,14are designed to measure the temperature in the proximity of the baking surface3(that is, of the floor “P”) and of the top wall5(that is, of the ceiling “C”), respectively.

They are connected, respectively, to the first drive module9aand to the second drive module9bof the control unit9to provide the respective drive module9a,9bwith a signal representing the measured temperature.

Preferably, the first temperature sensor13is located in the bottom zone or floor “P” of the oven space2.

Similarly, the second temperature sensor14is located in the top zone or ceiling “C” of the oven space2.

In the embodiment illustrated, the temperature sensors are thermocouples mounted respectively in the proximity of the ceiling “C” and of the floor “P”.

Alternatively, however, the temperature sensors might be sensors of another type.

Thus, the first drive module9aand the second drive module9bof the control unit9are configured to drive the respective radiating element10,11as a function of the signal, representing the temperature, provided by the respective temperature sensor13,14.

More precisely, the radiating elements10,11are each equipped with respective valve means (not illustrated) selectively adjustable between a closed configuration and a fully open configuration.

The drive modules9a,9bare programmed to send to the valve means a signal representing the closing or opening thereof as a function of the signal representing the temperature measured by the temperature sensors13,14.

More precisely, when the temperature measured by the sensors13,14is greater than a set reference value, the drive modules9a,9bcommand the valve means of the respective radiating element10,11to perform a closing movement to reduce fuel consumption and flame temperature.

On the other hand, when the temperature measured by the sensors13,14is less than a set reference value, the drive modules9a,9bcommand the valve means of the respective radiating element10,11to perform an opening movement to increase fuel consumption and flame temperature.

In order to allow setting the reference temperature (that is, the reference value), the oven1comprises an interface panel15associated with the control unit9and having at least a first control element15aand a second control element15bassociated with the first drive module9aand the second drive module9b, respectively.

The first control element15aand the second control element15bare accessible to a user to allow setting a required temperature at the baking surface3(or floor zone “P”) and at the top wall5(or ceiling zone “C”).

The first control element15aand the second control element15bmay thus be embodied, for example, by knobs, keyboards, touch screens or the like.

Each of the control elements15a,15bis thus connected (by wired or wireless means) to the respective drive module9a,9bof the control unit9to send to the latter a signal representing the value of the user-set (required) temperature for the respective zone (ceiling “C” or floor “P”).

Each drive module9a,9bis then programmed (configured) to compare the signal representing the value of the temperature set (by means of the interface panel15) with the signal representing the value of the temperature measured inside the corresponding zone of the oven space2(by the respective temperature sensor13,14) and configured to drive the radiating elements10,11(more specifically, the valve means) as a function of this comparison, preferably following a predetermined algorithm.

In the preferred embodiment, the control panel15is also equipped with display means16(analog or digital) configured to show the user the temperature measured by the temperature sensors13,14in the floor zone “P” and in the ceiling zones “C”.

Furthermore, the display means16(thanks to a specific display or numbered scale) preferably also show the user the temperature to be set.

Looking in more detail at the components, it should be noted that the burner means8(that is, the first and the second radiating element10and11) are preferably of atmospheric type.

In other words, each radiating element10,11takes in air in a natural manner by the “Venturi effect”.

More precisely, each radiating element10,11is connected to a source of fuel (methane gas, LP gas or the like) through a pipe with a constricted section at an inlet point where the fuel flows in (thereby creating the Venturi effect).

Thus, the burner means8are located (at least partly) under the baking surface3.

More precisely, the burner means8face the underside3bof the baking surface3.

In other words, the baking surface3is interposed between the burner means8and the top 5 of the oven space2.

It should be noted that to allow the burner means8(located under the baking surface3) to heat the ceiling zone “C”, the second radiating element11faces at least one respective duct12, located at least one side wall4of the oven space2and extending between an inlet section12a, facing the second radiating element12, and an outlet section12blocated in the proximity of the top wall5(that is, of the ceiling “C” of the oven space2).

Preferably, the second radiating element11is located laterally of the baking surface3, that is, at (and hence substantially aligned with, along the vertical) at least one side wall4of the oven space2(preferably both side walls).

Advantageously, therefore, varying the intensity of the flame in the second radiating element11has little (if no) effect on the baking surface3, and hence on the floor zone “P” of the oven space2.

Preferably, at least the second radiating element11comprises at least two tubular elements11alocated on opposite sides of the baking surface3(preferably in the proximity of it, and more preferably, under it).

In this regard, it should be noted that the oven1is equipped with at least two ducts12, each located at a respective side wall4of the oven space2in order to allow heat to be carried towards the ceiling zone “C” of the oven space in a uniform (and balanced) manner.

The tubular elements each have a plurality (or multitude) of through holes to allow the heating flames to pass through.

These holes are directed upwards, that is to say, they are directed from the tubular element11aitself towards the duct12.

In the embodiment illustrated, the tubular elements11aare positioned in such a way as to protrude laterally of the baking surface3, so that the heat is directed upwards, that is, towards the ceiling “C” of the oven space3and not towards the floor “P”.

It should be noted that the tubular elements are made preferably of a metallic material, preferably iron.

In the preferred embodiment, these tubular elements are chromium plated to increase their resistance.

Preferably, both of the tubular elements11aof the second radiating element11are in fluid communication with a common gas feed duct “S2” by way of a pipe union or manifold11b.

Thus, in the embodiment illustrated, the second radiating element11is substantially in the shape of a “U”, where the stems of the “U” are the tubular elements11aand the base is the manifold11b.

More precisely, the shape of the second radiating element11illustrated substantially defines a “Y”, where the end stem of the letter is defined by the gas feed duct “S2”.

In order to heat the baking surface3(acting, preferably directly, on the underside3bthereof), the first radiating element10is interposed between the two tubular elements11aof the second radiating element11.

Thus, the first radiating element10is located inside a section whose perimeter is at least partly defined by the second radiating element11.

In the preferred embodiment, the first radiating element10also has at least one tubular element10alocated between the tubular elements11aof the second radiating element11.

Like these, the tubular element10aalso has a plurality (or multitude) of through holes to allow the heating flames to pass through.

These holes are directed upwards, that is to say, they are directed from the tubular element10aitself towards the baking surface3.

It should be noted that the tubular element10aof the first radiating element10may have different shapes, for example the shape of a “P”, a substantially circular shape or other shape.

In the preferred embodiment, however, the first radiating element10comprises (like the second) two tubular elements10a(substantially parallel to each other) spaced from each other and facing the underside3bof the baking surface3.

Both of the tubular elements10aare in fluid communication with a common gas feed duct “S1” by way of a pipe union or manifold10b.

It should be noted that the manifold10bof the first radiating element10is distinct from the manifold11b(or feed duct) of the second radiating element11.

Thus, the first radiating element10is also substantially in the shape of a “U” whose concavity is opposite to that of the second radiating element11and which is at least partly interpenetrated with the second radiating element.

Advantageously, that way, the manifolds10band11bof the first and second radiating elements are located on opposite sides of the burner means8, thus facilitating maintenance and/or installation

It should also be noted that the first and the second radiating element10and11may be part of a single component (made as a single part or welded together) or, preferably, they may be distinct parts to be mounted separately (and more easily).

In the embodiment illustrated, the first and the second radiating element10and11extend parallel to the main direction of extension “A” of the baking surface3(conveyor belt6) to act on the oven space2in its entirety.

Structurally, at least one side wall4of the oven has an inner partition4a, delimiting the oven space2, and an outer partition4b, distal from the oven space2and spaced from the inner partition4ato define the duct12.

In other words, the duct12is defined by a gap made along the respective side wall4.

Preferably, the inner partition4ais curved at the upper end of it in order to direct the heat towards the centre of the top wall5(that is, towards the centre of the ceiling “C”).

In this regard, the top wall5in turn has a concavity which faces the baking surface3so as to increase heat recirculation.

Preferably, there are two ducts12, located at both side walls4and thus, the above applies to both.

With reference to the embodiment illustrated, where the baking surface3is defined by a conveyor belt6, the side walls4extend parallel thereto and at the sides thereof.

The oven1is also equipped with ignition means (not illustrated), preferably embodied by electrically charged spark plugs, and/or with a safety device configured to detect the absence of the flame.

This device is preferably defined by a flame detector associated with the control unit9and configured to provide the latter with a signal indicating that there is no flame issuing from the burner means8.

The control unit9is in turn programmed to close the valve means of the burner means8when it receives that signal, thus limiting the escape of non-combusted gas to the oven1and to the atmosphere.

The invention achieves the preset aims and brings major advantages.

In effect, the possibility of controlling the temperature of the ceiling and of the floor independently of one another, as already stated above, allows making the oven of this invention an “all-purpose” oven usable to bake products of different kinds.

Moreover, using two different radiating elements, located under or in the proximity of the baking surface makes it possible to keep the structure of the oven (with atmospheric burners) substantially similar to the structure of traditional ovens, thus allowing considerable savings in design and production costs.