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
  • F23D14/02—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
  • F23D14/06—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 radial outlets at the burner head
• • 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
  • F23D2900/14—Special features of gas burners
  • F23D2900/14062—Special features of gas burners for cooking ranges having multiple flame rings

Definitions

• the present invention concerns a gas burner, of the type with three crowns of flames, able to be mounted on a frame either of a built-in cooking surface, or hob, or of a cooker.
• a gas burner with three crowns of flames is known, for a cooker or a hob, which comprises a base element, also called cup, or collector, attached to a frame of the cooker or hob and on which a gas injector is mounted.
• the known burner also comprises an intermediate body, arranged above the base element, and a flame-dividing head with three crowns, in turn arranged above the intermediate body.
• the intermediate body comprises a central sleeve coaxial with the gas injector in order to convey a mixture of primary air and gas towards the crowns of the flame- dividing head, and four radial supporting arms, made in a single piece with the central sleeve and angularly equidistant from each other.
• the radial arms of the intermediate body define at the lower part, cooperating with corresponding radial arms of the base collector, a plurality of first channels, through which the primary air is introduced and conveyed towards the gas injector.
• the radial arms of the intermediate body also define at the upper part, cooperating with corresponding radial arms of the flame-dividing head, a plurality of second channels through which the mixture of primary air and gas, arriving from the central sleeve, is conveyed towards an external crown of the flame-dividing head.
• the radial arms of the intermediate body define four open zones which allow the substantially vertical passage of so-called secondary air, which is sucked in upwards by the depression caused by the mixture of gas and air when the flame is lit.
• the secondary air is conveyed mainly towards the intermediate crown of the flame-dividing head, in order to feed, together with the mixture of primary air and gas, the flame of the intermediate crown itself.
• a general problem of the known three crown gas burner is the turbulence to which the air is subject when it is introduced. To be more exact, it is necessary to reduce to a minimum the risk that the air, both primary and secondary, be subjected to continuous variations in its trajectory.
• the known three crown gas burner has the disadvantage that the open zones, located between the radial arms of the intermediate body, cause a considerable irregularity in the trajectory of the secondary air. Consequently, the secondary air is easily subject to turbulence and sudden changes in direction, with the consequent risk that the flame of the intermediate crown is not constant, or that it is lit with considerable difficulty.
• a triple crown gas burner with a single crown structure which, in co-operation with an annular cap, defines a ring-shaped chamber having flame openings both on its inside perimeter and on its outside perimeter.
• the same crown and a second circular cap define a central circular chamber which has flame openings on its outside perimeter.
• a three crown gas burner is also known wherein the intermediate body and the flame-dividing head are shaped so that, before passing into the four upper radial channels towards the external crown, the mixture of primary air and gas passes through a horizontal Venturi chamber which is made above the vertical sleeve of the intermediate body and regulates the trajectory of the mixture, slowing down its speed.
• a horizontal Venturi chamber which is made above the vertical sleeve of the intermediate body and regulates the trajectory of the mixture, slowing down its speed.
• Such horizontal Venturi chamber has the disadvantage, however, that it is. particularly complex and expensive to make, in order to obtain a regular flow of the mixture of primary air and gas.
• the intermediate body comprises a scoop plate to provide secondary air for the inwards directed flames which takes part of the primary air stream supplied to the burner.
• scoop plate which comprises a lower horizontal segment and an upper horizontal segment connected by an intermediate inclined segment has the disadvantage to cause turbulence and considerable irregularity in the trajectory of the secondary air.
• the purpose of the present invention is to achieve a burner with three crowns wherein it is possible to regulate the trajectory of the secondary air in the intermediate zones between the radial supporting arms and, in particular, wherein the secondary air is diverted upwards with a substantially laminar motion, and therefore not turbulent .
• Another purpose of the present invention is to achieve a burner with three crowns wherein it is possible to regulate and stabilize the mixing of the primary air and gas without having recourse to making a horizontal Venturi chamber .
• the Applicant has devised, tested and embodied the present invention to achieve these and other purposes, to obtain further advantages and to overcome the shortcomings of the state of the art. SUMMARY OF THE INVENTION
• the present invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the present invention or variants to the main inventive idea.
• a gas burner of the triple crown type for a cooker or for a hob, comprises: a base element, commonly called cup, or collector, able to be attached to a frame of the cooker or hob and on which a gas injector is mounted; a flame- dividing head with three crowns, arranged above the base element; and an intermediate body comprising a central portion and a plurality of substantially horizontal radial supporting arms.
• the intermediate body is arranged between the base element and the flame-dividing head with three crowns so as to define, at the lower part, a plurality of first channels to introduce primary air to said gas injector and, at the upper part, a plurality of second channels towards the three crowns of the flame-dividing head.
• between the intermediate body, between said radial supporting arms, where secondary air transits, is provided with radial connecting portions, starting from said central portion and each having a substantially constant inclination downwards for all its extension, up to its edge, to deflect the secondary air in a substantially oblique direction towards the two more internal crowns of said three crowns .
• each edge of said radial connecting portions is rounded downwards .
• the aforesaid inclined connecting portions act as deflectors for the secondary air and allow to control its trajectory, limiting the risk of turbulence, in order to encourage, in particular, the lighting, the inter-lighting and the stability of the flame of an intermediate crown of the flame-dividing head.
• the radial connecting portions are arranged distanced above the frame of the hob or cooker and define, with the frame itself, a channel that communicates with the collector, through which supplementary primary air is introduced.
• supplementary primary air mixes with the greater part of the main primary air arriving from the first channels mentioned above.
• the supplementary primary air allows to considerably improve the mixing of the primary air with the gas inside the intermediate body, with the advantage that the flow of the mixture is considerably stabilized. This allows to obtain a stable flame even when there is no pan on the burner.
• the intermediate body comprises also a vertical sleeve, on which a vertical Venturi tube is formed and which has its lower extremity disposed substantially on a same horizontal plane of, or very near to, the upper part of the gas injector.
• the flame-dividing head is provided, in correspondence with a central zone, where the mixture of primary air and gas flows, with slowing means able to slow down the flow of the mixture, encouraging the substantially balanced distribution thereof between the three crowns of the flame-dividing head.
• the slowing means comprise a holed element, such as a plate, a disk or suchlike, advantageously made in one piece below the central crown of the flame-dividing head, and through which only a part of the mixture of primary air and gas passes in order to feed the central crown itself.
• - fig. 1 is a view from above of a burner with three crowns according to the present invention
• - fig. 2 is a section from II to II of fig. 1;
• - fig. 3 is a perspective view of an intermediate body of the burner in fig. 1 ;
• - fig. 4 is a view from above of the intermediate body in fig. 3;
• - fig. 5 is a view from below of the intermediate body in fig. 3.
• a gas burner 10 for a hob or a cooker comprises a base element, also called cup, or collector 12, for example made of aluminum alloy, mounted on a frame 11 of the hob.
• the collector 12 comprises a connector 13 which, at an external end 13a, is able to be connected to a gas pipe, not shown in the drawings, and at an internal end 13b, supports a gas injector 14.
• the burner 10 also comprises an intermediate body 18, removably mounted on the collector 12 by means of supporting feet 15, and a flame-dividing head 16 with three concentric crowns, i.e. a central crown 16a, an intermediate crown 16b and an external crown 16c.
• the flame-dividing head 16 and the intermediate body 18 are also made of aluminum alloy.
• a central cover 17 and annular cover 19 rest in removable manner on the flame-dividing head 16.
• the intermediate body 18 (figs. 2, 3, 4 and 5) comprises in a single piece a central portion 28, substantially plane and circular, and a vertical sleeve 29, which close the collector 12 at the upper part and define a central chamber 26, shaped substantially like a truncated cone, tapering upwards, which forms a vertical Venturi tube which extends towards the central zone of the flame- dividing head 16 and in which the gas and the primary air AP are mixed.
• the lower extremity 29a of the vertical sleeve 29 and the upper part of the gas injector 14 are disposed substantially on a same horizontal plane (fig. 2), or very near one to the other.
• the intermediate body 18 also comprises four radial arms 30, substantially horizontal, which define at the lower part with the frame 11 of the hob or cooker, four radial channels 27 (figs. 2, 3 and 5), through which most of the primary air AP is conveyed, due to depression in the central sleeve 29 when gas is delivered by the injector 14.
• the four radial arms 30 are associated at the upper part with corresponding radial arms 31 (figs. 1 and 2) of the flame-dividing head 16 in order to define four channels 33 where part of the mixture of gas and primary air AP is conveyed, at outlet from the central chamber 26.
• the four channels 33 convey the mixture mainly towards the external crown 16c, and partly towards the intermediate crown 16b of the flame-dividing head 16.
• the intermediate body 18 comprises, between the four radial arms 30, four connecting portions 36, which extend radially with a substantially constant inclination downwards, starting from the central portion 28 to below the external crown 16c of the flame- dividing head 16, to deflect without turbulence the secondary air AS in a substantially oblique direction towards the two more internal crowns 16a and 16b.
• each radial connecting portions 36 end with an edge 36a rounded downwards.
• the connecting portions 36 are inclined downwards and are arranged in this case in an intermediate position and distanced between the frame 11 and the flame-dividing head 16, so as to divide substantially into two channels, an upper channel 38 and a lower channel 40 (fig. 2), each intermediate zone between two adjacent radial arms 30.
• secondary air AS able to feed mainly the flame of the intermediate crown 16b, conveys through the upper channel 38 from the bottom upwards, due to depression.
• the secondary air AS is deflected in a substantially oblique direction and is directed in a targeted manner towards an intermediate zone between the central crown 16a and the intermediate crown 16b.
• the connecting portions 36 have a substantially plane upper surface in order to convey the secondary air AS in a substantially linear direction.
• the upper surface of each connecting portion 36 is shaped concave, with its concavity facing upwards.
• the aforesaid lower channel 40 communicates with the collector 12 so as to allow the supplementary primary air APc to be introduced, which is conveyed into the central chamber 26 of the vertical sleeve 29, to be mixed with the main primary air AP arriving from the radial pipes 27.
• the supplementary primary air APc which has a more tortuous path to follow, is introduced with a slight temporal delay and at a slower speed with respect to the primary air AP arriving from the radial pipes 27.
• the supplementary primary air APc improves the mixing of air and gas in the vertical sleeve 29, so as to obtain a stable trajectory of the mixture, so that it is not necessary to include a horizontal Venturi chamber.
• the inclination of the connecting portions 36 thus encourages and improves both the introduction of primary air AP, and also the introduction of secondary air AS.
• the connecting portions 36 allow to reflect the heat produced by the flames upwards, protecting the intermediate body 18 and further encouraging the lighting of the burner 10 even when it is hot.
• Another advantage of the burner 10 according to the invention is that the extension towards the outside of the connecting portions 36 of the intermediate body 18 allows to protect the collector 12 peripherally, from solid or liquid foods that might fall.
• the flame-dividing head 16 is provided, below the central crown 16a and above the vertical sleeve 29, with a holed disk 50 (fig. 2), which is able to slow down, to an optimum outlet speed, the introduction of the mixture of primary air AP and gas into the central crown 16a, favouring the distribution of the mixture into the channels 33 towards the peripheral crowns 16b, 16c.
• the holed disk 50 there are three holes 52, radially equidistant from each other and offset by 120°.
• the reduction in speed of the mixture of primary air AP and gas improves the stability of the mixture itself and has the advantage of reducing to a minimum the risk that the flame might become detached in correspondence with the central crown 16a, or return to the central chamber 26, or that the flames of the central crown 16a and the intermediate crown 16b might possibly join up.
• the position of the holes 52 allows an easy intervention thereon, in order to clean them or restore them in the event that, during use, they should become dirty or blocked, simply by temporarily removing the central cover 17.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Gas Burners (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)
• Spray-Type Burners (AREA)
• Pre-Mixing And Non-Premixing Gas Burner (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=33524072

Family Applications (1)

Country Status (8)

Cited By (6)

Families Citing this family (4)

Citations (6)

• 2003
  • 2003-06-23 IT IT000137A patent/ITUD20030137A1/it unknown
• 2004
  • 2004-06-22 PL PL04743786T patent/PL1649216T3/pl unknown
  • 2004-06-22 DE DE602004020995T patent/DE602004020995D1/de not_active Expired - Lifetime
  • 2004-06-22 CN CNB200480020888XA patent/CN100472133C/zh not_active Expired - Fee Related
  • 2004-06-22 WO PCT/IB2004/002065 patent/WO2004113792A1/en active Application Filing
  • 2004-06-22 AT AT04743786T patent/ATE430901T1/de not_active IP Right Cessation
  • 2004-06-22 EP EP04743786A patent/EP1649216B1/en not_active Expired - Lifetime
  • 2004-06-22 ES ES04743786T patent/ES2327235T3/es not_active Expired - Lifetime

Patent Citations (6)

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