BURNER, PARTICULARLY FOR SOLID FUELS

Technical field

The present invention relates to a burner and to a stove associated therewith, ^" which can be supplied with solid fuel, such as pellets, wood, mixed wood/pellets fuel, waste of oleaginous seeds, macerated kernel shells, macerated toiomasses, or similar fuels. Background art

Stoves are commercially available which are composed of a containment body for a firebox into which the fuel to be burned is fed by means of per se known devices.

The firebox (or, if provided, the firebox holder) is connected generally to an air intake, which as a consequence of the partial vacuum that occurs within the containment body, or rather the combustion chamber, allows to draw air from outside the stove in order to feed it to the firebox. Since the firebox is generally perforated due to the presence (at its bottom and/or its side wall) of openings, the air that enters the firebox holder, if provided, is fed to the firebox and therefore feeds the combustion of the solid fuel.

In order to allow the combustion of the fuel during the ignition step, at a lateral portion of the firebox there is an opening designed to be crossed by an ignition device adapted to raise the fuel to the appropriate temperature.

One rather strongly felt drawback of these stoves is the difficulty of bringing some of the solid fuels used (for example oleaginous seeds or pressed wood) to such a temperature as to cause its spontaneous combustion.

Some materials used as fuel in fact require a temperature of more than 700 ⁰ C to burn, and this temperature is not reached by using the ignition devices described above and currently in use. In order to try to obviate the problem described above, so-called

mixed-feed stoves have already been provided which initially feed the firebox with the fuel which is easily flammable (for example pellets) and then mix with such fuel a gradually increasing percentage of the other type of fuel once a temperature sufficient to ensure good combustion has foeen reached inside the firebox.

Moreover, it has been found that the openings and apertures provided in the firebox must have such dimensions as to ensure a sufficient floλv of air inside the burner. However, their dimensions on the one hand must allow to retain the fuel to be burned within the seat formed by the firebox and on the other hand must allow the ash, or in any case most of it, to fall into the collection compartment arranged below the firebox.

In currently commercially available stoves, burners have openings whose dimensions are such as to ensure a sufficient air stream but do not allow to evacuate effectively the ash and residues of combustion deposited on the bottom of the firebox.

This determines the need to operate manually, and while the burner is off, on the combustion firebox in order to remove the ash. Moreover, the ash and the residues of the combustion process deposited on the bottom of the firebox obstruct some (if not all) of the openings, preventing part of th.e air from entering, during the combustion process, the seat in order to feed the combustion in an optimum manner. Disclosure of the invention

The aim of the present invention is to eliminate or at least reduce drastically the drawbacks noted above in known types of stoves. Within this aim, an object of the present invention is to provide a burner which can use a broad range of solid fuels.

Another object of the present invention is to provide a stove which can offer better operating efficiency.

Another object of the present invention is to provide a stove which has a burner capable of burning any type of solid fuel without the user

having to worry about cleaning the combustion firebox.

This aim and these and other objects which will become better apparent hereinafter are achieved by a stove having the features disclosed in the appended claims. Brief description of the drawings

Further characteristics and advantages of the invention will become better apparent from the description of some preferred but not exclusive embodiments of a stove according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein: Figure 1 is a front elevation view of a first embodiment of a stove according to the invention;

Figure 2 is a side elevation view of the stove of Figure 1;

Figure 3 is a top elevation view of the stove of Figures 1 and 2;

Figure 4 is a sectional view of the stove, taken along the plane of arrangement IV-IV of Figure 1;

Figure 5 is a sectional view of the stove, taken along the plane of arrangement V-V of Figure 3;

Figure 6 is a top view of the heating means;

Figure 7 is a side elevation view of a containment firebox; Figure 8 is a top elevation view of the containment firebox illustrated in Figure 7;

Figure 9 is a front elevation view of a second embodiment of a stove according to the invention;

Figure 10 is a sectional view, taken along the plane of arrangement X- X of Figure 9;

Figure 11 is a view of a possible variation of the burner associated with the stove shown in Figures 9 and 10;

Figure 12 is an enlarged-scale sectional view of Figure 10 related to the region of the burner; Figure 13 is an enlarged-scale view of the variation of the burner

shown in Figure 11 ;

Figure 14 is a partially sectional perspective view of a particular embodiment of a burner which can be associated with a stove according to the invention; and Figure 15 is a perspective view of a cylindrical element which constitutes the closure element. Ways of carrying out the invention

In the examples of embodiments that follow, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other examples of embodiments.

Moreover, it is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer. Initially with reference to Figures 1 to 8, a stove which can be supplied with solid fuel (pellets, wood, wood/pellet mix, waste of oleaginous seeds, macerated shells and kernels, macerated biomasses or similar materials), generally designated by the reference numeral 1, comprises a containment body 2, inside which, generally at the back 3, there is a reservoir 4 for containing the fuel used to feed the stove 1.

The containment reservoir 4 is associated with a device 5 for feeding the fuel into a combustion firebox 6, which forms a containment seat inside which the combustion of the fuel occurs.

In greater detail, at the base of the containment reservoir 4 it is possible to provide a screw feeder 7, which is adapted to draw from the fuel in order to feed it to the combustion firebox 6.

Generally, as shown in the figures, the combustion firebox 6 is supported by a firebox holder 8.

According to a first aspect of the present invention, the combustion firebox 6 has at least one heating portion 9 at which there is a plurality of

openings 9a.

The stove 1 is further provided with heating means 11, which are arranged so as to at least partially face the heating portion 9 formed on the combustion firebox 6. With particular reference to Figures 7 and 8, it can be seen that the combustion firebox 6 has a bottom portion (which in the illustrated case corresponds substantially to the heating portion 9), which is connected to a lateral containment surface 12, which can have equally a rectangular cross- section but also a circular or oval cross-section. Advantageously, the lateral containment surface 12 also has a plurality of openings 9a; in this case, there is nothing to prevent the heating portion 9 from being provided at a region formed on the lateral containment region 12 of the combustion firebox 6.

According to the embodiment shown in the figures cited above, the heating means 11 are arranged, during use, below the bottom portion of the combustion firebox 6 and have a series of gaps 14, which allow the ash and the combustion products to fall into a collection compartment 102.

With particular reference to Figure 6, it can be seen that the heating means 11 can be constituted by a coil 12a, which can be connected, at the respective connection ends 13, to an electric power supply.

It is evident that the heating means 11 allow to heat by radiation and rapidly and effectively, through the openings 9a, the fuel contained within the combustion firebox 6.

It is further convenient to associate the heating means 11 with a control unit, optionally connected to a timer and/or to means for detecting the temperature within the combustion firebox 6. Of course, as explained more clearly hereinafter, there is nothing to prevent the provision of the heating portion 9 at a region located on a lateral containment surface 12 of the combustion firebox 6. With reference now to Figures 9 to 14, a stove 1 has a burner 101

which is designed to burn solid fuels in general.

The burner 101 comprises a combustion firebox 6, which forms a containment seat for the fuel to be burnt.

In a manner similar to the embodiments described earlier, the supply device 5 has a containment reservoir 4, from which a screw feeder 7 draws the fuel in order to feed it into the containment seat.

According to the present invention, the combustion firebox 6 comprises at least one containment body 10, which forms in a downward region a discharge outlet 10a, which is closed at least partially by a closure portion 100a provided on a closure element 100.

The closure element 100 can move along at least one movement direction in order to move at least one part of a discharge portion 100b, arranged upstream of the closure portion 100a, along the movement direction into a position for closing the outlet 10a and at the same time move at least part of the closure portion 100a outside the containment receptacle.

In greater detail, the burner 101 is provided with means for discharging the residues of combustion from the discharge portion 100b into a collection compartment 102. In particular, the combustion residues are meant to pass by gravity from the discharge portion 100b into the collection compartment 102.

In order to achieve this result, the collection compartment 102 is arranged below the discharge portion 100b.

Advantageously, at least part of the discharge portion 100b lies on a plane which is inclined with respect to the horizontal plane, or its surface meant to support the combustion residues is, during movement, adapted to be arranged so that it faces the collection compartment 102.

Conveniently, the containment body 10 is provided with a plurality of openings 9b adapted to allow to feed air into the containment seat. According to a preferred embodiment, the closure element 100 also

comprises a plurality of openings 9a, which are adapted to allow the feeding of air into the receptacle.

With particular reference to the embodiment illustrated in the figures, the closure element 100 can be constituted by at least one cylindrical element 110, associated with a supporting shaft which is supported by the burner so that it can rotate about a respective movement axis.

As shown in the Figures, the closure element 100 can be constituted by two cylindrical elements 110, the longitudinal axes whereof are parallel and face each other. As an alternative, the closure element 100 can be constituted by a conical or frustum-shaped element, supported by a supporting shaft which is supported by the burner 101 so that it can rotate about a movement axis.

Conveniently, the burner 101 is provided with means for moving the closure element 100 along said at least one movement direction. Said movement means can be constituted by a motor 120, which can be controlled from a control unit and is adapted to move a motor shaft, which is connected kinematically to the supporting shaft or shafts of the cylindrical elements 110 or generally to the closure elements 100.

The control unit can be programmed in order to move the closure elements 100 at specified time intervals and at specified movement speeds depending on the fuels used or on the characteristics of combustion.

Moreover, there is nothing to prevent the user from being able to operate

(directly or even manually) the movement means if necessary.

According to another aspect, a stove 1 has, above the combustion firebox 6, a combustion chamber 20.

The stove 1 is provided with forced ventilation means 21, which are adapted to draw hot air at a collection pocket 22 arranged adjacent to the combustion chamber 20 and are adapted to send the drawn hot air toward said combustion firebox 6. In greater detail, the containment body 2 comprises a front closure

hatch 24, which is substantially transparent. According to an important aspect of the invention, the forced ventilation means 21 are associated with at least one baffle 25, which is adapted to direct a portion of the hot air propelled by said forced ventilation means 21 so that it strikes (tangentially) the front closure panel 24.

Advantageously, the forced ventilation means 21 can be constituted by a fan.

Operation of the stove according to the present invention is evident from what has been described above. During ignition, the supply means feed fuel, of any kind, to the combustion firebox, while the control unit controls the actuation of the heating means 11 so as to allow to transfer heat, substantially by radiation, through the openings 9a, to the fuel contained within the combustion firebox 6. Once the fuel has been ignited, the heating means are switched off and combustion is self-sustained by the flames generated by the combustion proper.

In particular, during the operation of the stove, depending on the type of solid fuel used and/or on the characteristics of the combustion in progress, the motor means move the movement means and therefore the closure elements 100. For example, if the closure means 100 are constituted, as shown, by one or more cylindrical elements 110, their rotation about their own longitudinal axis produces the passage of the closure portion 100a outside the seat, with the consequence that the ash deposited thereon moves, in a first step, out of the seat and then into the collection compartment 102.

At the same time, part of the cylindrical element or elements 110 arranged upstream of the closure portion 101a are arranged at the outlet 10a (thus providing the new closure portion 100a), with the advantage of achieving the discharge of the ash without interrupting combustion, since the seat is closed even on its bottom at all times at its outlet 10a.

If the stove is provided with forced ventilation means and with the baffle, it has been found that the wall of the air that strikes the closure hatch allows to keep it clean without compromising in any way the functionality and thermal efficiency of the stove. All the characteristics of the invention described above as advantageous, convenient or the like may also be omitted or be replaced with equivalents.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

In practice it has been found that the invention has achieved the intended aim and objects in all of its embodiments.

In practice, the materials used, as well as the dimensions, may be any according to requirements. All the details may further be replaced with other technically equivalent elements.

The disclosures in Italian Patent Applications no. VR2004A000155 and no. VR2005A000108, from which this application claims priority, are incorporated herein by reference. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.