Multi-fuel burner

Abstract

A burner (100) comprises a combustion head (20) configured to receive a comburent fluid and a combustible fluid, and to mix them with each other so as to generate a flame. Said combustion head (20) comprises a first dispensing unit (210) for a first combustible fluid and a second dispensing unit (220) for a second combustible fluid different to the first combustible fluid. Wherein the first and second dispensing unit (210, 220) are housed in said combustion head (20) and configured to be crossed by the same flow of a comburent fluid.

Description

[0001] “MULTI-FUEL BURNER”

[0002] * * * * *

[0003] TECHNICAL FIELD

[0004] The present invention relates to a burner, in particular intended to be operatively and mechanically associated with a combustion chamber, so as to generate a flame inside the chamber itself.

[0005] In further detail, the burner according to the invention is included in the field of manufacture and marketing of burners and more generally of machines, apparatuses and / or systems for the generation of thermal energy (i.e. heat) by means of controlled combustion of one or more combustible fluids, for example gaseous (methane, propane, butane, natural gas, biogas, and still others), with a comburent fluid (e.g. air).

[0006] The burner according to the invention has a specific application in the technical sector of industrial type burners, in particular intended for industrial process systems, such as, for example, furnaces for the metallurgy and / or ceramic and / or glass-making industry, and also for the production of steam in boilers installed, for example, in electric power plants, commercial or residential buildings, and more generally in industrial processes of various type.

[0007] In addition, the burner according to the invention has a further application in the civil sector of district heating, in particular when installed in thermal power plants for the production of thermal energy (i.e. heat) intended for heating buildings in residential districts.

[0008] PRIOR ART

[0009] In the aforementioned technical sector, it is known to use burners for the production of thermal energy (i.e. heat) by means of controlled combustion of a combustible fluid with a comburent fluid, in particular intended for industrial applications such as the ones briefly described above.

[0010] For example, a burner of the known type comprises a combustion head configured to receive a comburent fluid and a combustible fluid, and to mix them with each other so as to generate a flame by means of controlled combustion between said fluids.

[0011] In more detail, the burner comprises a feed pipe of the combustible fluid and a feed pipe of the comburent fluid.

[0012] The burners of known type briefly described so far have proved to be not without drawbacks in practice.

[0013] In particular, the main drawback lies in the fact that the burners of known type are operatively not very flexible and versatile. In fact, such burners do not allow optimal burning, or at least satisfactory burning, of many types of combustible fluids different to each other. Therefore, each specific type of combustible fluid requires an equally specific burner in order to be burned in an optimal manner. The result is that, in order to burn various types of combustible fluids, it is necessary to have specific burners especially designed or configured for corresponding specific combustible fluids.

[0014] In light of what has just been described, a further drawback lies in the fact that the burners of the known type are not very efficient, and have a low, or unsatisfactory, overall production output.

[0015] OBJECTS OF THE INVENTION

[0016] An object of the present invention is to provide a burner that allows the drawbacks of the aforementioned prior art to be overcome.

[0017] A further object of the present invention is to provide an operatively flexible burner, i.e. one that allows a plurality of combustible fluids different to each other to be processed in the same burner, without having to use specific burners for each type of combustible fluid.

[0018] A further object of the present invention is to provide a burner that is thermally efficient, i.e. one that has an overall production output that is higher than for the burners commonly available on the market.

[0019] A further object of the present invention is to provide a burner having an alternative and / or improved configuration, both in construction terms and functional terms, with respect to the solutions of the prior art.

[0020] SUMMARY All the objects, both individually and in any combination thereof, and others that will result from the detailed description that follows, are achieved, according to the invention, with a burner having the characteristics indicated in independent claim 1.

[0021] The dependent claims outline particularly advantageous embodiments of the invention.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Further features and advantages of the present invention will become more apparent from the indicative and thus non-limiting description of a preferred but non-exclusive embodiment of a burner as illustrated in the appended drawings, in which:

[0024] - Figure 1 shows, according to a perspective view, a burner according to an embodiment of the present invention;

[0025] - Figure 2 shows, according to a longitudinal sectional view, the burner illustrated in Figure 1 ;

[0026] - Figure 3A shows, according to a partial perspective view, the burner illustrated in Figure 1 , with some parts removed to better highlight others;

[0027] - Figure 3B shows, according to an exploded perspective view, the detail illustrated in Figure 3B.

[0028] With reference to the drawings, they serve solely to illustrate embodiments of the invention with the aim of better clarifying, in combination with the description, the inventive principles at the basis of the invention.

[0029] DETAILED DESCRIPTION OF THE INVENTION

[0030] With reference to the appended figures, a burner according to the present invention is indicated in its entirety by reference number 100.

[0031] More specifically, the burner 100 according to the invention is particularly intended to be operatively installed on a wall of a combustion chamber - for example in an industrial plant such as the ones briefly cited above - for the production of thermal energy (i.e. heat). The thermal energy produced can, for example, be used to produce steam in a boiler or a heat generator, then used in a thermodynamic heating cycle for a multitude of industrial application sectors or to burn waste gases produced at industrial level.

[0032] In accordance with the embodiment illustrated in the appended figures, the burner 100 comprises a combustion head 20 configured to receive a comburent fluid and a combustible fluid, and to mix them with each other so as to generate a flame by means of controlled combustion between said fluids.

[0033] According to an aspect of the invention, the burner 100 comprises a support body 110 extending between a first end 110a and a second end 110b opposite to the first end 110a.

[0034] Preferably, the support body 110 is internally hollow, so as to define an internal channelling suitable for being crossed by a comburent fluid.

[0035] Preferably, the support body 110 is made of a metallic material, in particular steel or cast iron, so as to give strength and rigidity to the burner 100 during operation thereof.

[0036] As illustrated in Figure 1 , the combustion head 20 is mechanically mounted on the support body 110 at the first end 110a, and both are arranged aligned along a combustion axis Y-Y along which the flame extends. Preferably, the combustion axis Y-Y is arranged, during use, substantially parallel to the ground, i.e. horizontal.

[0037] In accordance with the embodiment illustrated in the appended figures, the combustion head 20 comprises a first dispensing unit 210 for a first combustible fluid and a second dispensing unit 220 for a second combustible fluid different to the first combustible fluid.

[0038] According to one aspect of the invention, in particular illustrated in Figure 1 , the burner 100 comprises a blower 120 in fluid connection with the combustion head 20, and configured to generate a flow rate of comburent fluid towards the combustion head 20. Preferably, the blower 120 is mechanically connected to the support body 110 at the second end 110b, i.e. in a position opposite the combustion head 20; and is drawn in rotation by means of an electric motor.

[0039] In this manner, the blower 120 generates a predefined flow rate of comburent fluid, and conveys it towards the first and second dispensing unit 210, 220, so as to generate the aforesaid combustion flame with the first and second combustible fluid.

[0040] Preferably, the comburent fluid processed by the blower 120 is air, in particular atmospheric air at ambient temperature or preferably preheated atmospheric aria (for example, through heating means, such as electric resistors or similar).

[0041] According to the embodiment of the invention, the first and the second dispensing unit 210, 220 are housed in the same combustion head 20 (defined by a tubular body that encloses said dispensing units 210, 220, as described in more detail below), and each configured to be crossed by a same flow of the comburent fluid.

[0042] Advantageously, the burner 100 according to the invention is flexible and versatile, as it is capable of burning, through a single combustion head 20, two different types of combustible fluids different to each other (the burner 100 is defined as single-head, but multi-fuel). In other words, the burner 100 is capable of simultaneously processing inside it several combustible fluids, in particular two combustible fluids different to each other, allowing a combustion thereof that is substantially complete and efficient (as described in greater detail in the description below).

[0043] As illustrated in Figure 2, the first dispensing unit 210 is shaped so as to define housing spaces within which the second dispensing unit 220 is arranged.

[0044] In other words, the first and second dispensing unit 210, 220 are housed one inside the other and coaxial to each other along the aforesaid combustion axis Y-Y. In particular, the first dispensing unit 210 extends externally to the second dispensing unit 220, enveloping it. In accordance with the embodiment illustrated, in particular, in Figure 2, the first and second dispensing unit 210, 220 comprise respectively a first and a second tail portion 210a, 220a, preferably arranged coaxial to each other, along a combustion axis Y-Y, and configured to connect mechanically and fluidly respectively with a first and a second supply conduit 30a, 30b respectively for the first and the second combustible fluid, independent from each other.

[0045] Preferably, the first and second tail portion 210a, 220a have a tubular shape, configured to be inserted into a respective tubular end portion of the first and second conduit 30a, 30b, so as to receive the first and second combustible fluid.

[0046] In addition, according to an aspect of the invention, the first and second dispensing unit 210, 220 each comprise a first and a second head portion 210b, 220b each having a plurality of branchings that extend radially so as to obtain an annular arrangement of the crown type.

[0047] In other words, the first and second head portion 210b, 220b are in fluid connection with the respective first and second tail portion 210a, 220a.

[0048] In particular, the aforesaid branchings start from the respective first and second head portion 210b, 220b and comprise conduits configured to transport the first and second combustible fluid at the combustion head 20. More specifically, each branching of the first and second head portion 210b, 220b comprises respective nozzles 230 configured to dispense respectively the first and the second combustible fluid. In particular, the nozzles 230 are arranged alternating with each other radially around the combustion axis Y- Y.

[0049] As illustrated in Figure 4, the nozzles 230 are arranged substantially in spoke-like fashion around the combustion axis Y-Y, and alternate preferably regularly with each other, i.e. in an alternating manner between a nozzle 230 belonging to the first head portion 210b and a nozzle 230 belonging to the second head portion 220b and so on. Preferably, the first and second dispensing unit 210, 220 are shaped with respective branchings of the respective head portions 210b, 220b in a shape substantially similar to a first and a second spider.

[0050] According to an aspect of the invention, the nozzles 230 are arranged substantially on a same plane orthogonal to the combustion axis Y-Y.

[0051] In other words, as illustrated in Figure 2, each nozzle has an end portion thereof substantially aligned with the one of the other nozzles 230 along the combustion axis Y-Y.

[0052] Otherwise, according to an embodiment of the invention not illustrated in the appended figures, the nozzles 230 are arranged distanced from each other along the combustion axis Y-Y. For example, the nozzles 230 belonging to the first head portion 210b of the first dispensing unit 210 can be positioned rearward or in a forward position relative to the nozzles 230 of the second head portion 220b of the second dispensing unit 220.

[0053] According to an aspect of the invention, the combustion head 20 comprises a tubular body 40 configured to wrap, at least partially, around the first and second dispensing unit 210, 220, so as to allow the comburent fluid to cross them.

[0054] As illustrated in Figure 2, the tubular body, during use, is mechanically mounted on the support body 110 at the first end 110a, and defines a casing or protective shell around, at least partially, the first and second dispensing unit 210, 220 (in particular around the nozzles 230).

[0055] In other words, the tubular body defines a kind of containment bell, at least partially, for the first and second head portion 210b, 220b of the respective dispensing units 210, 220.

[0056] According to an aspect of the invention, the tubular body is preferably made of a metallic material, in particular preferably steel sheet.

[0057] In accordance with the embodiment illustrated, in particular, in Figure 2, the tubular body 40 comprises a cylindrical section 410 arranged, at least partially, around the nozzles 230 of the first and second head portion 210b, 220b of the dispensing units 210, 220. In particular, the cylindrical section 410 defines a supply conduit for the comburent fluid.

[0058] In fact, according to an aspect of the invention, the comburent fluid flows, at least mainly, through an interspace defined between an outer dimension of the nozzles 230 of the first and second head portion 210b, 220b and an inner wall of the cylindrical section 410.

[0059] According to an aspect of the invention, the tubular body 40 preferably comprises a flared section 420 connected to the cylindrical section 410, and configured to diffuse towards a combustion chamber a flow of the comburent fluid, so as to regulate an intensity of the flame along the combustion axis Y-Y.

[0060] As illustrated in Figure 2, preferably the flared section 420 has a conical shape configured to facilitate a diffusion of the comburent fluid and allow a regulation of the combustion head 20 relative to the flared section 420 itself, in order to increase a dispensed power modulation ratio (i.e. the ratio between a maximum and minimum power dispensable by the burner during the operation thereof).

[0061] In accordance with further embodiments not illustrated in the appended figures, the tubular body 40 may not have the aforesaid flared section 420 and have a substantially cylindrical profile with uniform transverse section. In accordance with the embodiment illustrated, in particular, in Figures 1 and 2, the burner 100 further comprises a diffuser body 430 mounted at the first and second head portion 210b, 220b.

[0062] Preferably, the diffuser body 430 is a circular plate having inside it a plurality of holes; and is mechanically mounted on the second head portion 220b of the second dispensing unit 220.

[0063] According to an aspect of the invention, at least one of the first and second dispensing unit 210, 220, preferably both together, is movable along the combustion axis Y-Y, between a retracted configuration, in which the diffuser body 430 reduces, at least partially, a passage section of the comburent fluid across the cylindrical section 410; and a diffusion configuration, in which the diffuser body 430 increases said passage section.

[0064] Advantageously, the burner 100 is efficient, since, by means of the aforesaid movement of at least one dispensing unit thereof, it allows regulation of a predefined and specific flow rate of comburent fluid (i.e. air) that crosses the combustion head 20, as a function of the type of combustible fluid it is burning. In this manner, the burner 100 is capable of optimising combustion between the comburent fluid and the first and second combustible fluid, thus obtaining a substantially complete combustion of the aforesaid combustible fluids. The result is a high overall production output of the burner 100, or at least one higher than for the burners of the prior art. According to an aspect of the invention, the burner 100 comprises regulation means 50a, 50b mounted respectively on the first and second supply conduit 30a, 30b, and selectively activatable independently from each other by an electronic control unit, towards said first and second tail portion 210a, 220a of said first and second dispensing unit 210, 220.

[0065] In particular, the electronic control unit comprises at least one signal receiving module, at least one received signal processing module and at least one processed signal sending module; and is configured to control the regulation means 50a, 50b in order to regulate a flow rate of the first and the second combustible fluid through respectively the first and second supply conduit 30a, 30b.

[0066] Advantageously, the burner 100 allows regulation of a flow rate of the first and the second combustible fluid that crosses a passage section of the first and second supply conduit 30a, 30b.

[0067] In this manner, the burner 100 offers a further degree of regulation relative to the regulation of the flow rate of comburent fluid just described above.

[0068] In fact, the regulation means 50a, 50b are controllable separately from each other and allow the passage through them of a desired flow rate value of the first and second combustible fluid. For example, the first supply conduit 30a can preferably convey biogas; whereas the second supply conduit 30b can convey natural gas. In particular, the flow rate of natural gas and biogas that flows through the first and second conduit 30a, 30b can be regulated for each from a value equal to 0%, corresponding with a closed condition of each conduit, to a value equal to 100%, corresponding with a condition of complete opening of each said conduit.

[0069] In particular, the regulation means 50a, 50b are respectively configured to regulate: the flow rate of the first combustible fluid only through the first conduit 30a towards the first tail portion 210a; and the flow rate of the second combustible fluid only through the second conduit 30b towards the second tail portion 220a.

[0070] In particular, the term “only” is intended to mean that the regulation means 50a, 50b are respectively configured to regulate only the flow rate of the first fluid and the flow rate of the second combustible fluid independently from further combustible fluid dispensing nozzles present outside said combustion head 20.

[0071] Furthermore, the burner 1 comprises only said first and second dispensing unit (210, 220) housed in said combustion head (20) and does not comprise other third combustible dispensing nozzles arranged inside or outside said combustion head 20 (in particular arranged inside or outside said cylindrical body 410 or diffuser body 430).

[0072] According to an aspect of the invention, the regulation means 50a, 50b comprise respective butterfly valves arranged along a transverse section of the first and second supply conduit 30a, 30b.

[0073] Preferably, the butterfly valves are the servo-controlled type, i.e. the regulation means 50a, 50b comprise servomotors configured to receive a signal from the electronic control unit and therefore to activate the movement of the butterfly valve. According to an aspect of the invention, the first and second combustible fluid are preferably selectable from among: methane, natural gas, hydrogen, biogas, gasoil, liquid gas, LPG, oils or others not expressly indicated here. According to one aspect of the invention, the burner 100 can operate with three combustible fluids, for example two gaseous combustible fluids and one liquid combustible fluid.

[0074] In this case, it is preferable to provide one or more nozzles in the combustion head 20, configured to dispense the third combustible fluid, for example liquid.

[0075] In particular, the first and second combustible fluid are combinable with each other in the same burner 100 to produce a combustion flame.

[0076] It should be noted that the combustion head 20 is configured to dispense directly the first and second combustible fluid, through the first and second dispensing unit 210, 220, outside said combustion head. In other words, a pre-mixing area is not present inside said combustion head 20 between said first and second combustible fluid.

[0077] In yet other words, the first and second dispensing unit 210, 220 are not configured to dispense combustible fluid in a pre-mixing area inside the combustion head 20, but dispense it directly outside.

[0078] A further object of the present invention is also a method for the controlled combustion of a plurality of combustible fluids with a comburent fluid in a burner 100, the numerical references of which will be retained for the sake of descriptive simplicity. What is stated above in reference to the burner 100 is therefore referenced in full below insofar as concerns the method.

[0079] Such burner 100 according to the aforesaid method comprises a combustion head 20 configured to receive a comburent fluid and a combustible fluid, and to mix them with each other so as to generate a flame. The method according to the invention comprises the following operating steps: conveying a comburent fluid towards the combustion head 20; - conveying a first combustible fluid towards the combustion head 20 through a first supply conduit 30a;

[0080] - conveying a second combustible fluid towards the combustion head 20 through a second supply conduit 30b;

[0081] - regulating, by means of regulation means 50a, 50b independent from each other, a flow rate of the first and second combustible fluid through respectively said first and second supply conduit 30a, 30b independently from each other towards respective first and second dispensing units 210, 220;

[0082] - mixing the comburent fluid with the first and the second combustible fluid inside the combustion head 20;

[0083] - generating a flame by means of a controlled combustion between the comburent fluid and the first and the second combustible fluid in the same combustion head 20.

[0084] Preferably, the method comprises the further step of controlling regulation means 50a, 50b, arranged to intercept the passage of the first and second combustible fluid across a transverse section of the first and second supply conduit 30a, 30b.

[0085] Preferably, the burner 100 according to the invention can obtain a plurality of combustion combinations between natural gas and biogas, for example selectable from the following percentage ratios and vice versa: 50-50%, 60- 40%, 70-30%, 80-20%, 90-10%.

Claims

1 . A burner (100), comprising a combustion head (20) configured to receive a comburent fluid and a combustible fluid, and to mix them with each other so as to generate a flame by means of controlled combustion between said fluids; said combustion head (20) comprises a first dispensing unit (210) for a first combustible fluid and a second dispensing unit (220) for a second combustible fluid different to the first combustible fluid; said first and second dispensing unit (210, 220) being housed in said combustion head (20) and each configured to be crossed by a flow of comburent fluid; said first and second dispensing unit (210, 220) comprise respectively a first and a second tail portion (210a, 220a) mechanically and fluidly connected with a first and a second supply conduit (30a, 30b) respectively for the first and for the second combustible fluid, independently from each other, characterised in that said burner (1 ) further comprises regulation means (50a, 50b) mounted respectively on said first and second supply conduit (30a, 30b), and selectively activatable independently from each other by an electronic control unit; said electronic control unit being configured to control said regulation means (50a, 50b) to regulate a flow rate of the first and second combustible fluid through respectively said supply first and second supply conduit (30a, 30b) independently from each other through said first and second tail portion (210a, 220a) of said first and second dispensing unit (210, 220).

2. The burner (100) according to claim 1 , characterised in that said regulation means (50a, 50b) are respectively configured to regulate: the flow rate of the first combustible fluid only through the first conduit (30a) towards the first tail portion (210a); and the flow rate of the second combustible fluid only through the second conduit (30b) towards the second tail portion (220a).

3. The burner (100) according to claim 1 or 2, characterised in that said regulation means (50a, 50b) are respectively configured to regulate only the flow rate of the first fluid and the flow rate of the second combustible fluid independently from further combustible fluid dispensing nozzles present outside said combustion head (20).

4. The burner (100) according to any one of the preceding claims, characterised in that it comprises solely said first and said second dispensing unit (210, 220) housed in said combustion head (20) and used for dispensing combustible fluid.

5. The burner (100) according to any one of the preceding claims, wherein said first and second tail portion (210a, 220a) are arranged coaxial to each other, along a combustion axis (Y-Y).

6. The burner (100) according to any one of the preceding claims, wherein said first and second dispensing unit (210, 220) each comprise a first and a second head portion (210b, 220b) each having a plurality of branchings that extend radially so as to obtain an annular arrangement of the crown type.

7. The burner (100) according to claim 6, wherein each branching of said first and second head portion (210a, 220b) comprises respective nozzles (230) configured to dispense respectively the first and the second combustible fluid; said nozzles (230) of said first head portion (210b) being arranged alternating relative to said nozzles (230) of said second head portion (220b) radially around said combustion axis (Y-Y).

8. The burner (100) according to claim 6 or 7, wherein said nozzles (230) are arranged substantially on the same plane orthogonal to said combustion axis (Y-Y).

9. The burner (100) according to one of claims 6 to 8, wherein said nozzles (230) are arranged distanced from each other along said combustion axis (Y-Y).

10. The burner (100) according to any one of the preceding claims, wherein said combustion head (20) comprises a tubular body (40) configured to wrap, at least partially, around said first and second dispensing unit (210, 220) so as to allow the comburent fluid to cross them.

11. The burner (100) according to claim 10, wherein said tubular body (40) comprises a cylindrical section (410) arranged, at least partially, around the nozzles (230) of said first and second head portion (210, 220b) of the dispensing units (210, 220); and wherein said cylindrical section (410) defines a supply conduit for said comburent fluid.

12. The burner (100) according to claim 11 , wherein said tubular body (40) further comprises a flared section (420) connected to said cylindrical section (410), and configured to diffuse towards a combustion chamber a flow of the comburent fluid, so as to regulate an intensity of the flame along the combustion axis (Y-Y).

13. The burner (100) according to any one of the preceding claims, comprising a diffuser body (430) mounted at said first or second head portion (210b, 220b); and wherein at least one of said first and second dispensing unit (210, 220) is movable along said combustion axis (Y-Y), between a retracted configuration in which the diffuser body (430) obstructs, at least partially, apassage section of the comburent fluid across said cylindrical section (410); and a diffusion configuration in which the diffuser body (430) frees up the passage section.

14. The burner (100) according to any one of the preceding claims, wherein said regulation means (50a, 50b) comprise respective butterfly valves arranged along a transverse section of said first and second supply conduit (30a, 30b).

15. The burner (100) according to any one of the preceding claims, comprising a blower (120) in fluid connection with said combustion head (20), configured to generate a flow rate of comburent fluid towards the combustion head (20).

16. The burner (100) according to any one of the preceding claims, wherein the first and the second combustible fluid are selectable between: methane, natural gas, hydrogen, biogas, diesel, liquid gas, LPG, oils; and wherein the first and the second combustible fluid are combinable with each other in the same burner (100) to produce a combustion flame.

17. The burner (100) according to any one of the preceding claims, wherein said combustion head (20) is configured to dispense directly said first and second combustible fluid, through said first and second dispensing unit (210, 220), outside said combustion head and a pre-mixing area is not present inside said combustion head (20) between said first and second combustible fluid.

18. A method for the controlled combustion of a plurality of combustion fluids with a comburent fluid in a burner (100) comprising a combustion head (20) configured to receive a comburent fluid and a combustible fluid, and to mix them with each other so as to generate a flame;said method comprising the following operating steps:- conveying a comburent fluid towards said combustion head (20);- conveying a first combustible fluid towards said combustion head (20) through a first supply conduit (30a); - conveying a second combustible fluid towards said combustion head(20) through a second supply conduit (30b);- regulating, by means of regulation means (50a, 50b) independent from each other, a flow rate of the first and second combustible fluid through respectively said first and second supply conduit (30a, 30b) independently from each other towards respective first and second dispensing units (210, 220);- mixing the comburent fluid with the first and the second combustible fluid inside the combustion head (20);- generating a flame by means of a controlled combustion between the comburent fluid and the first and the second combustible fluid in the same combustion head (20).

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