IT202100007760A1 - HEATING EQUIPMENT - Google Patents

Description

Description of the invention entitled:

"HEATING EQUIPMENT"

FIELD OF APPLICATION

The present invention refers to a low-emission heating apparatus which exploits the known pyrolysis process, also called pyro-scission, or gasification, of a biomass, for example pellets or other wood-derived materials, to produce heat. The heating equipment can? find application in the space heating sector, for example domestic or industrial, public places, or places open to the public, but also in the boiler sector to produce sanitary water and/or to be used in heating systems.

STATE OF THE ART

Heating apparatuses are known, commonly called stoves, which, as fuel, use biomass in an incoherent form, for example formed by chips, pellets or the like, in which combustion takes place thanks to the presence of an oxidizing agent, usually consisting of the oxygen contained in the? ambient air, which ? supplied as primary air and secondary air.

The primary air is let into a brazier to feed the combustion of the biomass after an initial fire of this? last.

When fully operational, pyrolysis takes place during combustion, i.e. the process of physical and chemical decomposition of the combustible biomass, caused by its heating to temperatures between about 300?C and about 600?C.

How?? As known, pyrolysis decomposes biomass into two parts: one gaseous and one solid. The gaseous part? constituted by a flammable mixture of gases, such as mainly carbon monoxide, hydrogen and methane, and a condensable compound, known to those skilled in the art with the acronym TAR, while the solid part? substantially composed of coal, also known by the term CHAR.

The mixture of gases derived from pyrolysis, which in the sector? called ?syngas?, . ? set on fire by means of a trigger and with the introduction of secondary air, it completes the combustion of the biomass, generating heat and a flame.

The known stoves, which are based on the pyrolysis process, have a brazier in which it can be heated. be loaded the biomass, which then can? be set on fire. In the brazier can primary air be introduced to create a so-called ?flame cap? above the biomass.

When the stove ? in function, the heat of the combustion goes down in the brazier near? of the unburned biomass and causes the pyrolysis of the latter. Then, to complete the combustion, the secondary air is introduced into the brazier which ignites the combustible gases deriving from the pyrolysis.

These known stoves have for? a series of drawbacks such as, for example, a low performance, a poor versatility? of use, a difficult management of the power and speed? production of combustible gases and discontinuous operation.

In fact, the combustion process takes place until the loaded biomass ? completely consumed by the pyrolysis process. When does this process end, due to the? depletion of biomass, ? necessary to reload other biomass into the brazier and then restart the process by switching it on again. ? therefore it is quite evident that these operations require the intervention of an operator.

Furthermore, the introduction of ambient air, having an oxygen component equal to about 23.3% by weight, into the brazier contributes to a high production of polluting gases. In fact, biomass also includes nitrogen, generally linked with the carbon and hydrogen atoms present in it, and which, as? Known, it binds with the oxygen in the ambient air introduced into the brazier, producing nitrogen oxides, which are very polluting.

Is there therefore a need? to produce a new and original heating apparatus which can overcome at least one, better if all, the drawbacks of the prior art.

A purpose of the present invention ? that of realizing a heating device that produces reduced polluting emissions in the environment.

Another aim of the present invention ? to create a? heating equipment that allows you to adjust both the speed? production of combustible gases, and the heat power generated.

Another object of the present invention ? that of realizing a heating apparatus which also allows to obtain continuous or continuous operation, i.e. without interruptions and which, moreover, can be easily automated at least to allow automatic restart and shutdown. To obviate the drawbacks of the prior art and to obtain these and further objects and advantages, the Applicant has studied, tested and implemented the present invention.

DISCOVERY DISPLAY

The present found ? expressed and characterized in the independent claim. The dependent claims disclose other characteristics of the present invention or variants of the idea of the main solution.? - In accordance with the aforementioned purposes, a heating apparatus which overcomes the drawbacks of the prior art and eliminates the defects present therein, comprises both a brazier which in turn comprises a first inlet opening for receiving a biomass with fuel function and a second opening to receive a first comburent, both a combustion chamber and a? autonomous with respect to said brazier, delimited by a plurality? walls and suitable for developing heat through a flame.

According to one aspect of the invention, on at least one first wall of the aforementioned plurality? of walls are obtained one or more? recirculation openings each of which ? connected by means of recirculation means to the aforesaid second opening of the aforesaid brazier.

According to another aspect of the present invention , the aforesaid heating apparatus also comprises a containment body configured to define, together with the aforesaid first wall, a closed containment compartment in which the aforesaid recirculation means are arranged.

According to another aspect of the present invention , in the aforementioned containment body ? at least one feed opening communicating with the external environment is formed and said combustion chamber also comprises an inlet opening communicating with said containment compartment.

According to another aspect of the present invention , the aforesaid recirculation means comprise at least one recirculation duct which? substantially parallel to the aforementioned first wall and ? detached from this? last and the aforesaid containment body also comprises a partition wall which divides the aforesaid containment compartment into a first part containing the aforesaid at least one recirculation duct, and in a second part which substantially borders at least the aforesaid first wall.

According to another aspect of the present invention , the upper part of the aforesaid dividing wall ? arranged substantially in correspondence with the area in which the aforementioned at least one recirculation duct ? connected to said at least one recirculation opening. Furthermore, said first part and said second part communicate with each other at said upper part of said dividing wall.

According to another aspect of the present invention , the aforesaid recirculation means comprise a plurality of recirculation ducts substantially parallel and detached from each other, said first wall comprises a corresponding plurality of recirculation openings each communicating with a respective one of the aforementioned recirculation ducts. According to another aspect of the present invention , the heating apparatus also comprises a first fan fluidically connected downstream of the aforesaid recirculation means and upstream of the aforesaid second opening of the aforesaid brazier.

According to another aspect of the present invention said combustion chamber also comprises at least one evacuation opening and the heating apparatus further comprises a second fan connected downstream of said at least one evacuation opening and upstream of the environment external to convey at least a part of the fumes produced by the aforementioned flame into the aforementioned combustion chamber.

According to another aspect of the present invention , the heating apparatus also comprises a unit control and a sensor placed downstream of the aforementioned combustion chamber and configured to detect the quantity? of oxygen present in the aforementioned fumes and to transmit to the aforementioned unit? control a signal proportional to the amount? of oxygen detected in the aforementioned fumes to allow the aforementioned unit? control system to regulate at least the flow generated by the aforesaid second fan according to the aforesaid signal.

According to another aspect of the present invention , the aforementioned brazier also comprises an outlet opening which is in fluid communication with said inlet opening of said combustion chamber by conveying means.

According to a further aspect of the present invention a heating process comprises the following steps:

- prepare a combustion chamber and draw a first combustive agent from the latter;

- providing a brazier and introducing into the latter both a biomass with fuel function and the aforesaid first comburent to thermo-chemically decompose the aforesaid biomass and produce at least one fuel gas;

- conveying said combustible gas into said combustion chamber;

- drawing in a second oxidizing agent from the external environment (and heating it by means of a heat exchange between the latter and the aforementioned first oxidizing agent; and

- conveying said second heated combustion agent into said combustion chamber to ignite said fuel gas and develop heat by means of a flame.

According to a further aspect of the present invention , the heating process also comprises the following steps:

- detect the quantity? of oxygen present in the fumes produced by the aforementioned flame; And

- adjust the flow rate of the aforementioned second combustion agent according to the aforementioned quantity? of oxygen present in the aforementioned fumes.

ILLUSTRATION OF THE DESIGNS

These and other aspects, characteristics and advantages of the present invention will become clear from the following description of some embodiments, provided by way of non-limiting example, with reference to the accompanying drawings in which:

- fig. 1 ? a schematic block representation of a heating apparatus according to the present invention in accordance with a first embodiment;

- fig. 2 ? a schematic block representation of a heating apparatus according to the present invention in accordance with a second embodiment;

- fig. 3 ? a schematic block representation of a heating apparatus according to the present invention in accordance with a third embodiment; _

- fig. 4 ? a schematic block representation of a heating apparatus according to the present invention in accordance with a fourth embodiment;

- fig. 5 ? a schematic block representation of a heating apparatus according to the present invention in accordance with a variant of the third embodiment;

- fig. 6 ? a schematic block representation of a heating apparatus according to the present invention in accordance with a variant of the fourth embodiment;

- fig. 7 ? a side sectional view of the heating apparatus of fig. 1 ;

- fig. 8 ? a section along the VIII-VIII line of fig. 7;

- fig. 9 ? an axonometric view of the heating apparatus of fig. 1 , taken from the back;

- fig. 10 ? a view, in isometric view, similar to that of fig. 9, but partially exploded;

- fig. 11 ? an electrical block diagram of a control circuit of the heating apparatus of fig. 1.

It should be noted that in the present description and in the claims the term vertical with its variations has the sole function of better illustrating the present invention with reference to the figures of the drawings and must in no way be used to limit the scope of the present invention, or the scope of protection defined by the attached claims. For example, with the term vertical we want to indicate an axis, or a plane, which can be both perpendicular to the horizon line and inclined, even by different degrees, for example up to 20?, with respect to the latter.

Furthermore, those skilled in the art will recognize that certain dimensions, or features, in the figures may have been magnified, distorted, or displayed in an unconventional or non-proportional way to provide a more accurate version. easy understanding of the present invention. When dimensions and/or values are specified in the following description, the dimensions and/or values are provided only for illustrative purposes and must not be understood as limiting the scope of protection of the present invention, unless such dimensions and/or values are present in the attached claims.

For ease of understanding, identical reference numerals have been used wherever possible to identify identical common elements in the figures. It should be understood that elements and features of one embodiment may be conveniently combined or incorporated into other embodiments without further specification.

DESCRIPTION OF SOME FORMS OF EMBODIMENT OF

PRESENT FOUND

With reference to fig. 1, a heating apparatus 10 according to the present invention ? of the pyrolysis type and, in accordance with a first embodiment, comprises thermochemical decomposition means M1 configured to receive a biomass C with fuel function and a first comburent F1, as will be? explained more after you. The thermochemical decomposition means M1 are suitable for thermally decomposing the biomass C and producing, by pyrolysis, combustible gases S, for example consisting mainly of methane, hydrogen, carbon monoxide.

The heating apparatus 10 also comprises a combustion chamber 20 configured to receive both a second combustive agent A, different from the first combustive agent F1, and the combustible gases S. The combustion chamber 20 ? suitable for developing heat by means of a flame fed by combustible gases S and which produces fumes F, how will it be? explained more after you.

Furthermore, the heating apparatus 10, in accordance with an aspect of the present invention, comprises both conveying means M2 interposed between the thermochemical decomposition means M1 and the combustion chamber 20 to convey the combustible gases S towards the latter, and recirculation means M3 for conveying at least a first part F1 of fumes F, which constitutes the aforesaid first combustion agent, from the combustion chamber 20 to the thermochemical decomposition means M1 .

Furthermore, the heating apparatus 10 comprises heat exchange means M4, associated with the recirculation means M3 and configured to heat the second combustion agent A, using the heat contained in the first combustion agent F1 before the same second combustion agent A reaches the heating chamber combustion.

Below, with reference to figs. 1 and 7 to 11, ? illustrated more in detail the first embodiment of the heating apparatus 10.

The thermochemical decomposition means MI comprise a brazier 11 which is substantially closed with respect to the external environment and delimited by four side walls 12 and by an upper wall 13. Furthermore, the brazier 11? delimited at the bottom by a metal plate 14 provided with at least one outlet opening 15.

The outlet opening 15 of the brazier 11 ? also configured to allow the combustible gases S to exit and the burnt and/or thermo-chemically decomposed biomass C to be discharged from the brazier 11.

The metal plate 14 can be selectively removable or openable, in any known way, to allow access from below to the brazier 11, for example to carry out maintenance or cleaning thereof.

Furthermore, the brazier 11 has an inlet opening 16 for the introduction of the biomass C, comprising, for example, incoherent wooden material such as chips, pellets or the like, and an inlet opening 18 from which it can? enter the first comburent F1 that ? of air type.

The inlet openings 16 and 18 of the brazier 11 are preferably arranged in the upper part of the latter, i.e. at a lower level. higher than that where the outlet opening 15 is located. This conformation allows the introduction of the biomass C and the first combustive agent F1 from top to bottom.

It should be noted that the mutual position of the first opening 16 and the second opening 18 can vary with respect to that illustrated in the drawings, so that, for example, one, or both, can be arranged laterally, or one at a different level with respect to the other.

In an alternative embodiment, not shown in the figures, the first opening 16 of the brazier 11 can be placed substantially at the level of the lower part of the same. In this configuration the biomass C pu? be introduced into the brazier 11 from the bottom upwards, or, alternatively, laterally, i.e. in a substantially horizontal manner. For example, the first opening 16 can? be arranged substantially at the level of the metal plate 14 to introduce the biomass C directly above this? last.

Furthermore, inside the brazier 11 ? there is an ignition device 19, configured to selectively trigger the combustion of the biomass C, for example when the heating equipment 10 is switched on.

In the embodiment shown here, the ignition device 19 comprises an electric resistance disposed in a lower area of a side wall 12, i.e. close to the metal plate 14, for example in the same side wall 12 where ? obtained the first inlet opening 16.

The ignition device 19 can? be sized to contact, in use, with the biomass C present in the brazier 11. Alternatively, the ignition device 19 can? be configured to ignite the biomass C indirectly, i.e. by heating the air in contact with the latter.

The combustion chamber 20 ? substantially closed and ? in fluid communication with the brazier 11 through a preferably watertight conveyance compartment 21. In particular, the conveying compartment 21 ? interposed between the lower part of the brazier 11 and the lower part of the combustion chamber 20. Alternatively, the conveying compartment 21 can? be replaced by one or more? ducts.

It should be noted that, in accordance with an aspect of the present invention, the brazier 11 and the combustion chamber 20 are autonomous, separated from each other and connected in a fluid way via the conveying compartment 21.

According to one aspect of the invention, the combustion chamber 20 is fluidly connected with the combustion inlet opening 18 of the brazier 11. In particular, in the embodiment described here, the combustion chamber 20 is? delimited by two side walls 22, by an upper wall 23, by a front wall 24, for example that can be opened, with the function of a closing door, by a rear wall 25 and by a lower wall 26.

On an upper part of the rear wall 25, one or more? recirculation openings 27, each communicating with one end? top of a respective recirculation duct 28, external to the combustion chamber 20 and having one end? bottom which, through a collector 43, ? connected to the intake of a first fan 29, whose delivery ? Auly connected to the second inlet opening 18 of the brazier 11. In addition or alternatively, the recirculation openings 27 can be obtained in other walls of the combustion chamber 20.

Preferably the recirculation ducts 28 are substantially parallel to each other and to the rear wall 25, as well as detached from each other and from the latter, for example from 1 to 3 cm.

The heating apparatus 10 also comprises a containment body 32, substantially box-shaped, on which two feed openings 3 1 are made, which communicate with the outside and through which it can be heated. enter the second oxidiser A.

The containment body 32 ? Mounted on the outer surface of the rear wall 25 of the combustion chamber 20 creating, in cooperation with the latter, a containment compartment V in which the recirculation ducts 28 are arranged.

In the bottom wall 26 of the combustion chamber 20, substantially in a central area thereof, obtained an?inlet opening 33, in which? positioned a nozzle 30 having, in the example provided here, a central duct 34 arranged along a substantially vertical longitudinal axis X, and a series of lateral through holes 35, which lie substantially on a substantially horizontal plane P and arranged below the wall bottom 26. The side holes 35 communicate with the central duct 34.

It should be noted that the shape and arrangement of the central duct 34 and of the side holes 35 can also differ greatly from what is described here and represented in the attached figures. For example, instead of the side holes 35 pu? be obtained an opening, or a slot, (not shown) of any suitable shape and size.

The central duct 34 ? in communication with the conveying compartment 21 and has the function of injecting the combustible gases S into the combustion chamber 20, while the side holes 35 have the function of conveying the second combustion agent A, coming from the containment compartment V. In particular, the lateral holes 35 are configured to promote mixing between the second combustive agent A and the combustible gases S in order to facilitate the combustion of the latter.

Are the feed openings 31 disposed below the ends? lower than the recirculation ducts 28, i.e. substantially at the level j of the lower part of the combustion chamber 20.

Furthermore, inside the containment body 32? arranged a dividing wall, or septum, 37 which substantially divides the containment compartment V into two parts, i.e. into a first part V1, in which the recirculation ducts 28 are arranged, and into a second part V2, which borders both the wall rear 25, and the lower wall 26 of the combustion chamber 20.

The first part V1 and the second part V2 of the containment compartment V communicate with each other at the upper part of the partition 37 which, preferably, ? arranged at the ends? of the recirculation ducts 28, i.e. where the latter are connected to the respective recirculation openings 27.

Therefore, in use, the second combustion agent A enters from the supply openings 3 1 , travels through the first part V 1 of the containment compartment V and heats up in contact with the recirculation ducts 28, until it reaches the top. of the septum 37. Then, the second combustion agent A enters the second part V2 of the containment compartment V from above and runs through it until it reaches the side holes 35 of the nozzle 30, lapping against the rear wall 25 of the combustion chamber 20, heating itself further.

It should be noted that, thanks to this conformation, the containment body 32, in cooperation with the recirculation ducts 28 and the walls 25 and 27 of the combustion chamber 20, constitutes a counter-current heat exchanger, which corresponds to the aforementioned exchange means thermal M4.

Furthermore, on each of the side walls 22 (fig. 8) of the combustion chamber 20 there are evacuation openings 36, each of which ? connected to a respective evacuation pipe 38, external to the combustion chamber 20 and substantially vertical.

Each evacuation pipe 38 ? fluidly connected to an evacuation chamber 40, in turn connected to the suction of a second fan 39 (fig. 7), the delivery of which is? communicating with the outside of the equipment 10.

The heating apparatus 10 can? optionally also comprising an external containment structure 41, substantially having the shape of a parallelepiped and comprising a second compartment 42, inside which both the evacuation pipes 38 and at least a part of the combustion chamber 20, the conveying compartment 21 and the evacuation chamber 40.

The external structure 41 has in its lower part an inlet opening 47, to which a third fan 45 is connected to selectively introduce ambient air R into the second compartment 42, and in the upper part an outlet opening 44 from which it can? the same air R coming out in contact with the evacuation pipes 38,

The heating apparatus 10 also comprises an injection device 46, of any type known per se, to introduce the biomass C in a controlled manner, both intermittently and continuously, into the brazier 11.

In the example provided here, the injection device 46 comprises a container 48, substantially in the shape of a hopper, containing a load of biomass Ced. an associated doser 49, of a type known per se, having an output connected to the inlet opening 16 of the brazier 11 and configured to dose the quantity? of biomass C introduced into the brazier 11 in a selective and proportional way to specific electrical signals, under the control of a unit? control 50 (f?g. 11), how will it be? more described in detail below.

The doser 49 (fig. 7) ? of the type which comprises a rotating element 51 provided with radial blades 52 and connected to an electric motor 53 (fig. 11) controlled by the unit? of control 50. At each rotation of the rotating element 51, even partial, a determined quantity? of biomass C ? introduced into the brazier 11.

It is therefore clear that the quantity? of biomass C introduced in the brazier 11, in a given unit? of time, ? speed function? of rotation of the rotating element 51 (fig. 7).

In other embodiments, not shown in the drawings, the dispenser 49 can include an auger.

The heating apparatus 10 also comprises a sensor 58 (figures 7 and 11), also of a type known per se? and, for example, consisting of a lambda probe, which ? suitable to detect the quantity? of oxygen present in the environment that surrounds it. In the example provided here, the sensor 58 ? positioned downstream of the combustion chamber 20 and in particular inside the evacuation chamber 40.

In other embodiments, sensor 58 may be arranged inside the evacuation pipes 38 and/or inside the internal of the recirculation ducts 28 to detect the quantity? of oxygen in the fumes F.

The aforementioned sensor 58 ? connected to the unit? of control 50 and ? configured to transmit to the latter? an electrical signal SP proportional to the quantity? of oxygen it detects.

The unit of control 50 ? configured to also control the first fan 29 and the second fan 39 and possibly also the third fan 45.

In particular, the unit? control 50 pu? check the speed? of rotation of the first fan 29 and consequently the flow rate of the first combustion agent FI, the speed? of rotation of the second fan 39 and consequently the flow rate of the second combustion agent A and the speed? of rotation of the rotating element 51 of the doser 49 and consequently the flow rate of biomass C in the brazier 11.

In other embodiments of the present invention, not shown in the drawings, at least the side walls 22 of the combustion chamber 20 can an element in thermally conductive material, such as ceramics, can be fixed to increase thermal inertia.

In other embodiments of the present invention, not shown in the drawings, at least the side walls 22 of the combustion chamber 20 can be associated with one or more pipe for water circulation. With reference to figs. 2, in a second embodiment, a heating apparatus 100 according to the present invention can comprise all the components of the heating apparatus 10 described above except for the heat exchange means M4. In this embodiment, the heating apparatus 100 can furthermore comprise a second ignition device, not shown in the drawings, arranged substantially close to the of the nozzle 30 and configured to trigger the combustion of the combustible gases S.

With reference to figs. 3, in a third embodiment, a heating apparatus 200 according to the present invention can comprise all the components of the heating apparatus 10 described above except for the heat exchange means M4 and the first fan 29.

Also in this embodiment, the heating apparatus 200 can furthermore comprise a second ignition device, not shown in the drawings, arranged substantially close to the of the nozzle 30 and configured to trigger the combustion of the combustible gases S.

With reference to figs. 4, in a fourth embodiment, a heating apparatus 300 according to the present invention can include all the components of the heating apparatus 10 described above except for the first fan 29.

It should be noted that, in the third and fourth embodiments, the heating apparatus 200, 300 comprises only the second fan 39, connected to the combustion chamber 20 to suck the fumes F generated in the combustion chamber. inside of the latter.

Furthermore, in the third and fourth embodiments, a duct connected downstream of the second fan 39 may be connected to the brazier 11 to act as a recirculation means M3 to convey a first part F1 of the aforementioned fumes F, which acts as the first combustion agent.

In further possible variants of the third and fourth embodiments, the aforesaid duct, which acts as a recirculation means M3, can be arranged upstream of the second fan 39 and downstream of the combustion chamber 20 (figs. 5 and 6).

The operation of the heating apparatus 10 described up to now, which corresponds to the method according to the present invention, comprises the following steps.

When starting the heating equipment 10 the unit? of control 50 actuates the injection device 46 to introduce a determined quantity? of biomass C inside the brazier 11 and the ignition device 19 to ignite the biomass C in the brazier 11.

Furthermore, the unit? control 50 activates the first fan 29 which takes a first combustion agent F1 from the combustion chamber 20 and introduces it into the brazier 11. substantially ambient air is present.

The unit control 50 also actuates the second fan 39 which draws in the second combustion agent A from the external environment, through the supply openings 31, and introduces the latter into the combustion chamber 20 through its inlet opening 33.

In this start-up phase, the combustion between the biomass C inside the brazier 11 and the first comburent F1, which will later be? named boot combustion, ? basically of the reverse flame type, also called ?downdraft? by those skilled in the art, i.e. by introducing the first combustion agent F1 into the brazier 11 from top to bottom, so that it crosses in this sense the biomass C disposed, in use, in the brazier 11 and consequently generating a flame which is also directed from top to bottom, and smoke.

The fumes produced by the initial combustion are conveyed into the combustion chamber 20, through the conveying compartment 21, thanks to the suction supplied by the first fan 29 which, subsequently, introduces them again into the brazier 11. Therefore, in this phase, the first oxidizer F 1 ? consisting of a first part of the fumes from the start-up combustion.

In particular, a first part F1 of the aforementioned fumes of the start combustion ? sucked in by the first fan 29 by means of the first recirculation openings 27 and ? reintroduced into the brazier 11 from its second opening 18, acting as the first combustion agent F1, and a second part F2 of the aforementioned fumes from the start-up combustion ? sucked in by the second fan 39 by means of the evacuation openings 36 and ? expelled from the heating equipment 10.

After a given period of time, a steady state operating condition is reached in which the first comburent F1 has a temperature and a quantity of oxygen suitable for triggering the pyrolysis process of the biomass C present in the brazier 11.

At this point, the first combustion agent F1 introduced into the brazier 11? suitable for thermo-chemically decomposing the biomass C inside the brazier 11 and producing combustible gas S.

It should be noted that the thermo-chemical decomposition of the biomass C also takes place substantially in "downdraft", i.e. by introducing the first combustive agent F1 into the brazier 11 from top to bottom, so that it passes in this direction through the biomass C disposed, in use, in the brazier 11. In this way the combustible gases S produced by the thermo-chemical decomposition of the biomass C come out of the lower portion of the brazier 11. This configuration ? advantageous in that it forces the combustible gases S to pass through the biomass C contained in the brazier 11 and this? allows their volatile components to be split, producing combustible gases S with fewer TARs.

Therefore, during steady state operation, the outlet opening 15 of the brazier 1 1 no longer comes out. the fumes generated by the initial combustion but the combustible gases S generated by the thermochemical decomposition of the latter.

The procedure therefore provides for introducing the combustible gases S into the combustion chamber 20 through the conveying compartment 21, thanks to the suction of the first fan 29.

The process therefore provides for oxidizing, or igniting, the combustible gases S by means of the second oxidizing agent A introduced into the combustion chamber 20, producing a flame, fumes F and developing heat. Optionally, the procedure can plan to heat the second comburent A, using the heat contained in the first comburent F1 before the same second comburent A reaches the combustion chamber 20. This heat exchange ? preferably conducted in countercurrent.

It should be noted that, in this case, the triggering of the oxidation, or combustion, or fire, of the combustible gases S in the combustion chamber 20 takes place only by means of the? ?encounter? between the latter and the heated second comburent A. There? it is very advantageous as it does not require the presence and use of additional ignition devices.

As before, a first part F1 of fumes F generated, this time, by the combustion of combustible gases S ? sucked in by the first fan 29 by means of the recirculation openings 27 and ? reintroduced into the brazier 11 by its combustion inlet opening 18, acting as the first combustion agent F1, and a second part F2 of the fumes F ? sucked in by the second fan 39 by means of the evacuation openings 36 and ? expelled from the heating equipment 10.

At this point, the first part F1 of the fumes F, reintroduced into the brazier 11, and which in fact acts as the first combustion agent F1, has an oxygen component advantageously between about 7% and about 12% by volume, which is lower than that present in the ambient air. There? ? particularly advantageous as, cos? doing in the brazier 11 an anoxic environment is created, ie lacking in oxygen, which ? present in quantity? sufficient to predominantly react with the carbon present in the biomass C and generate the combustible gases.

Therefore, the production of polluting emissions such as, for example, nitrogen oxides, is considerably reduced given that there is no gas in the brazier 11? present a quantity? of oxygen sufficient to bind with the nitrogen included in the biomass C.

Furthermore, when fully operational, the first part F1 of the fumes F, when it enters the brazier 11, has a temperature of between about 240?C and about 320?C, i.e. ? advantageous in that at least part of the CO2 present in them is converted back into CO, i.e. carbon monoxide, which ? fuel. Another plus? that the water present in the gaseous phase in the first part F1 of the fumes F in the brazier 11 is converted into hydrogen, increasing the calorific value of the fuel gas S.

The unit The control unit 50 can also control the first fan 29 and the second fan 39 on the basis of the electrical signal received from the sensor 58. For example, the unit? control 50 pu? change the flow rate of the first combustion agent F1, of the second combustion agent A and/or of biomass C in feedback until? the value detected by the sensor 58 reaches a predetermined target value.

Optionally, the unit? control 50 also actuates the third fan 45 to generate a flow of ambient air R which passes into the second compartment 42 to exchange heat with the evacuation pipes 38, heating itself up. The ambient air R heated ? then conveyed again towards the external environment.

? it is clear that modifications and/or additions of parts can be made to the heating apparatus 10, without thereby departing from the scope of the present invention as defined by the claims.

? It is also clear that, although the present invention has been described with reference to some specific examples, a person skilled in the art could without doubt realizing many other equivalent forms of heating apparatus 10, all of which come within the scope of the present invention.

In the claims that follow, the references in brackets have the sole purpose of facilitating the reading and must not be considered as limiting factors of the scope of protection defined by the claims themselves.

Claims (12)

1. Heating apparatus (10, 100, 200, 300) comprising both a brazier (11) which in turn comprises a first inlet opening (16) for receiving a biomass (C) with fuel function and a second opening ( 18) to receive a first combustion agent (FI), both a combustion chamber (20) and ? autonomous with respect to said brazier (1 1), delimited by a plurality? of walls (22, 23, 24, 25, 26) and suitable for developing heat by means of a flame, characterized by the fact that on at least one first wall (25) of said plurality? of walls (22, 23, 24, 25, 26) are obtained one or more? recirculation openings (27) each of which ? connected via recirculation means (28) to said second opening (18) of said brazier (11) and that said heating apparatus (10) also comprises a containment body (32) configured to define, together with said first wall (25), a closed containment compartment (V) in which said recirculation means (28) are arranged. 2. Heating apparatus (10, 100, 200, 300) according to claim 1, characterized in that in said containment body (32) ? at least one supply opening (31) communicating with the external environment has been obtained and that said combustion chamber (20) also comprises an inlet opening (33) communicating with said containment compartment (V). 3. Heating apparatus (10, 100, 200, 300) according to claim 1 or 2, characterized in that said recirculation means comprise at least one recirculation duct (28) which ? substantially parallel to said first wall (25) of said combustion chamber (20) and ? detached from the latter and that said containment body (32) also comprises a partition wall (37) which divides said containment compartment (V) into a first part (V1) containing said at least one recirculation duct (28) , and in a second part (V2) which substantially borders at least said first wall (25). 4. Heating apparatus (10, 100, 200, 300) according to claim 3, characterized in that the upper part of said dividing wall (37) is? arranged substantially in correspondence with the area in which said at least one recirculation duct (28) is located. connected to said at least one recirculation opening (27) and that said first part (V1) and said second part (V2) communicate with each other at said upper part of said partition wall (37). 5. Heating apparatus (10, 100, 200, 300) according to any one of the preceding claims, characterized in that said recirculation means comprise a plurality of of recirculation ducts (28) substantially parallel and detached from each other and that said first wall (25) of said combustion chamber (20) comprises a corresponding plurality of recirculation openings (27) each communicating with a respective one of said recirculation ducts (28). 6. Heating apparatus (10, 100, 200, 300) according to any one of the preceding claims characterized in that it also comprises a first fan (29) fluidically connected downstream of said recirculation means (28) and upstream of said second opening (18) of said brazier (11). 7. Heating apparatus (10, 100, 200, 300) according to any one of the preceding claims characterized in that said combustion chamber (20) further comprises at least one evacuation opening (36) and which furthermore comprises a second fan (39) connected downstream of said at least one evacuation opening (36) and upstream of the external environment to convey at least a part (F2) of the fumes (F) produced by said flame into said combustion chamber ( 20). 8. Heating apparatus (10, 100, 200) according to claim 7 characterized in that it also comprises a unit? control (50) and a sensor (58) arranged downstream of said combustion chamber (20) and configured to detect the quantity? of oxygen present in said fumes (F) and to transmit to said unit? control (50) a signal (SP) proportional to the quantity? of oxygen detected in said fumes. (F) to allow said unit? control (50) to adjust at least the flow generated by said second fan (39) as a function of said signal (SP). 9. Heating apparatus (10, 100, 200, 300) according to claim 6, 7 or 8 characterized in that said brazier (11) also comprises an outlet opening (15) which is? in flu communication? said with said inlet opening (33) of said combustion chamber (20) by means of conveyance means (M2, 21). 10. Heating process, characterized in that it comprises the following steps: - set up a combustion chamber (20) and draw a first combustion agent (FI) from the latter; - prepare a brazier (11) and introduce into the latter both a biomass (C) with fuel function, and said first comburent (F1) to thermo-chemically decompose said biomass (C) and produce at least one fuel gas (S) ; - conveying said combustible gas (S) into said combustion chamber (20); - draw in a second comburent (A) from the external environment and heat it by means of a heat exchange between the latter and said first comburent (F1); And - conveying said heated second combustion agent (A) into said combustion chamber (20) to ignite said fuel gas (S) and develop heat by means of a flame. 11. Process as in claim 10 characterized in that it also comprises the following steps: - detect the quantity? of oxygen present in the fumes (F) produced by said flame; And - adjust the flow rate of said second combustion agent (A) according to said quantity? of oxygen present in said fumes (F). 12. Use of a heating apparatus (10, 100, 200, 300) as in any one of claims 1 to 9 and/or of a process as in claims 10 or 11, for space heating.