Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/12—Radiant burners
  • F23D14/14—Radiant burners using screens or perforated plates
  • F23D14/145—Radiant burners using screens or perforated plates combustion being stabilised at a screen or a perforated plate
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/02—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone
  • F23D14/04—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone induction type, e.g. Bunsen burner
  • F23D14/08—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone induction type, e.g. Bunsen burner with axial outlets at the burner head
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2203/00—Gaseous fuel burners
  • F23D2203/10—Flame diffusing means
  • F23D2203/101—Flame diffusing means characterised by surface shape
  • F23D2203/1017—Flame diffusing means characterised by surface shape curved
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
  • F23D2900/00003—Fuel or fuel-air mixtures flow distribution devices upstream of the outlet

Definitions

• the present invention relates to a pre-mixed gas burner cooled by an air- gas mixture.
• a pre-mixed gas burner operates to produce a flame for generating heat by a controlled burning of a comburent air-fuel gas mixture.
• a typical use application of a pre-mixed gas burner is a use in thermal generators for producing heat.
• Such a burner is arranged in a combustion chamber upstream of a heat exchanger or directly in a heat exchanger.
• High temperature fumes generated by the burner head flame are caused to flow through the heat exchanger and their heat is transferred to a heat conveyor fluid circulating in the exchanger.
• the pre-mixed gas burners conventionally comprise a gaseous fuel and comburent air mixture feeding and mixing system, an air-gas mixture conveying system and a flame generating head having an outer surface thereon a flame is generated.
• the burner head is heavily heated by the generated flame, in particular in a minimum power mode of operation, as the outlet speed of the air-gas mixture from the burner head is low and the flame is formed nearer to the burner surface.
• the high temperature of the burner head besides limiting the burner head lifetime, requires to adopt insulating and/or refractory materials to protect the outer parts of the burner, not affected by the burner flame, and of the conveying system therethrough said air-gas mixture flows.
• the aim of the present invention is to provide such a pre-mixed gas burner specifically designed for overcoming the above mentioned drawbacks of prior art burners.
• a main object of the invention is to provide such a burner which is very simple construction wise and which, moreover, has a construction cost much lower than that of corresponding prior burners.
• Another object of the present invention is to provide such a burner adapted to operate in a broad power modulating range, with a minimum power-maximum power ratio higher than 1 :10.
• Yet another object of the present invention is to provide such a burner which does not require a use of insulating and refractory materials.
• Yet another object of the present invention is to provide such a burner which, owing to its specifically designed structural features, is very reliable and safe in operation.
• an air and fuel or combustible gas mixture flows through the conveyor element and, as it arrives, through the distributing element, at the head of the burner, a burner flame is accordingly formed on an outer surface thereof.
• the distributing element comprises a plurality of different throughgoing holes allowing an increased air-gas mixture amount to flow to the burner head regions devoid of holes and flame, thereby allowing said regions to be cooled; said conveyor element being furthermore thermally protected by the distributing element and the air-gas mixture flow.
• Figure 1 is a cross-sectioned side elevation view of the burner according to the present invention.
• Figure 2 is a top plan view of the distributing element
• Figure 3 is a top plan view of the conveyor.
• the pre-mixed gas burner according to the present invention which has been generally indicated by the reference number 1 , comprises a conveyor element 2, a burner head 3 and a distributing element 4.
• the conveyor element 2 operates as a support and holder for the distributing element 4 and the burner head 3.
• the conveyor element 2 is thermally protected by the distributing element 4 and the air-gas mixture flow, thereby preventing said conveyor element 2 from being overheated.
• the burner head 3 has a convex shape and such a size as to fully close the combustion chamber 5 therewithin said burner head 3 is arranged.
• said burner head 3 comprises a throughgoing hole pattern through the central region 6, whereas its outer crown is devoid of throughgoing holes.
• an air-gas mixture 8 is ejected from the burner head holes, which mixture, directed on the outer surface of said burner head 3, provides a combustion reaction with a corresponding formation of a burning flame 7.
• the mentioned convex configuration helps to properly mechanically stabilize the burner, while preventing individual flame fronts from overlapping one another, thereby providing a "cleaner" combustion mode of operation.
• the geometry or pattern of said burner head 3 is, in the embodiment herein shown, a circular one, but said head may have any other desired configurations or patterns such as a square, rectangular, polygonal, elliptical configuration or pattern and so on.
• the throughgoing hole pattern 6 of said head 3 has been specifically designed to provide a homogeneous flame and an optimum combustion.
• throughgoing holes of different diameters are herein provided to drive the flame 7 on the burner surface.
• the burner head 3 hole pattern 6 is, in the embodiment herein illustrated, a circular one, but it would also be possible to provide holes or openings of any other desired geometrical patterns, such as elongated slot, elliptical and rectangular hole patterns.
• the hole size may be either a constant or an uneven one, and said holes may have an even or uneven geometry, thereby providing spaced regions of larger and smaller hole density and with either a constant or uneven hole pitch pattern.
• the outermost portion of the head 3, that is the outer crown for a circular burner or a region near an outer perimeter for a polygonal burner, is devoid of holes and accordingly of flames.
• the distributing element 4 coupled to the burner head 3 by a clamping connection 9 along the head perimeter.
• the distributing element 4 has a convex shape and comprises a perforated distributing element surface, with uneven dimensions between the outer circular crown 10 and inner region 11 , to allow the air-gas mixture to circulate between the distributing element and the burner head and to be evenly distributed through the outlet holes.
• the enlarged hole cross-section along said crown or outer perimeter 0 is designed to facilitate an enhanced air-gas mixture conveying and feeding to the peripheral unperforated region of the burner head 3.
• the above technical solution which represents a main feature of the present invention, allows a portion of the air-gas mixture to circulate between the distributing element 4 and the burner head 3, at said unperforated region.
• the circulating air-gas mixture before being ejected from said holes and generating the flame will touch the burner head 3 surface at the region of said head 3 devoid of holes and flame, thereby removing heat therefrom and reducing its temperature.
• the distributing elements further provides a thermal screening function of the underlying conveyor element 2 to protect the latter from the burner head 3 high temperature thereby preventing said conveyor from being overheated.
• the specifically designed distributing element 4 hole pattern allows said element 4 to be properly cooled, by the same circulating air-gas mixture.
• the invention has provided a pre-mixed gas burner overcoming the above prior art problems by a very simple safely operating and inexpensive structure, including a cooling system driven by the same air-gas mixture flowing through the burner, thereby greatly reducing the burner head flameless region temperature.
• This enhanced cooling in combination with a burner head so designed as to tightly close the head combustion chamber, achieves in particular the object of avoiding any insulating refractory materials.
• the burner according to the present invention can also operate with an air-gas mixture low outlet speed, and a flame very close to the burner head surface, thereby reducing the operating burner minimum power, while enhancing the power modulation range to a ratio higher than 1 :10.
• the different diameter burner head holes provide an optimum and homogeneous combustion through an "extended" power range of the inventive burner.
• the convex shape and the clamping of burner head and distributing element provide the burner with an improved mechanical stability and lifetime, and a very simple burner construction.
• the used materials, as well as the contingent size and shapes can be any, depending on requirements.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Gas Burners (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Cited By (3)

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Citations (3)

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• 2015
  • 2015-03-31 WO PCT/IB2015/000431 patent/WO2015150902A1/en not_active Ceased
  • 2015-03-31 EP EP15718080.3A patent/EP3126737B1/en active Active
  • 2015-03-31 RU RU2016135504A patent/RU2664267C2/ru active
  • 2015-03-31 ES ES15718080T patent/ES2769814T3/es active Active
  • 2015-03-31 PL PL15718080T patent/PL3126737T3/pl unknown

Patent Citations (3)

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