Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C7/00—Combustion apparatus characterised by arrangements for air supply
  • F23C7/002—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D1/00—Burners for combustion of pulverulent fuel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D17/00—Burners for combustion conjointly or alternatively of gaseous or liquid or pulverulent fuel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D99/00—Subject matter not provided for in other groups of this subclass
  • F27D99/0001—Heating elements or systems
  • F27D99/0033—Heating elements or systems using burners

Definitions

• the present invention relates to a burner used in particular in industrial furnaces, such as rotary kilns of cement, lime, alumina, oxides, minerals, etc.
• burner used in furnaces having several parallel (or coaxial) axis lines including a first external air supply line located outside of all other burner lines, a central line of an air supply having at least one central fuel supply pipe therein, at least one peripheral fuel supply pipe disposed around the central air supply pipe, and a second outer pipe air supply disposed around the peripheral fuel supply line.
• the present invention aims to achieve a new type of burner performance and particularly easy to adjust.
• the first external pipe is delimited by two tubes which are immobile with respect to one another and which carry at their downstream end, immovably, a first series of closed axial channels which are adapted to give a tangential component zero air moving therethrough
• the second outer conduit is delimited by two tubes that are axially movable relative to each other, the inner tube delimiting the second outer conduit to its downstream end, immovably, a second series of open channels which are adapted to impart a variable tangential component to the air moving therethrough, each channel having, relative to the axis of the burner, a decreasing tangential deflection from its upstream end to its downstream end, and the tube externally delimiting the second external pipe comprising a radially diverging drive portion from upstream to downstream so that the tangential deflection angle of the air at the downstream end of the second outer pipe depends on the relative axial position of the driving portion relative to the channels of the second series, and that the almost all of the air circulating in the external pipes leaving the
• the present configuration makes it possible to have a burner having a simple, easily adjustable configuration (the overall air flow resulting from the air leaving the two external ducts can be modified by the simple relative axial displacement of the two tubes delimiting the second pipe external) and able to operate with a high proportion of poor fuels (the axial air flow being formed by a series of single unit flows allowing to suck up a greater proportion of the secondary air coming from the furnace hearth).
• FIG. 1 is a longitudinal partial sectional view of a burner according to a first embodiment of the present invention
• FIG. 2 is a view similar to FIG. 1 of a burner according to a second embodiment of the present invention
• FIG. 3 is a view similar to FIGS. 1 and 2 of a burner according to a third embodiment of the present invention.
• Figure 4 is a longitudinal partial sectional view of a burner flame stabilizer according to the second embodiment.
• a burner 1 of rotary furnaces as illustrated in Figures 1 to 4 comprises several lines 2, 4, 5, 6, 7 coaxial. These pipes comprise a central air supply pipe 2 which is associated with a flame stabilizer 3 which is disposed at the outlet of this pipe 2.
• the stabilizer 3 is in the form of a disc which may comprise, to ensure its cooling and its scan, several axial cylindrical or several radial slots tangential to the disk.
• These ducts also comprise at least one (a 4 in FIGS. 1 and 2, two coaxial elements 4a, 4b in FIG. 3) central fuel supply pipe 4 which is disposed inside the central supply duct.
• air 2 here, in the axis of the burner 1, but which could be off-axis
• which opens through the flame stabilizer 3 via an opening 65 is a 4 in FIGS. 1 and 2, two coaxial elements 4a, 4b in FIG. 3
• central fuel supply pipe 4 which is disposed inside the central supply duct.
• air 2 here, in the axis of the burner 1, but which could be off-axis
• these conduits comprise at least one (here, a) peripheral fuel supply pipe 5 which is disposed around the central air supply pipe 2 (around the flame stabilizer 3).
• the pipes comprise a first external air supply pipe 6 which is located outside (around) all the other pipes 2, 4,
• the second external air supply pipe 7 which is arranged outside (around) the flame stabilizer 3.
• the second external air supply pipe 7 which is arranged around the peripheral fuel supply pipe 5.
• the first external pipe 6 is delimited by two tubes 8, 9 which are stationary relative to one another
• the channels 10 of the first series are angularly distributed regularly so that each outlet orifice 11 is separated from the two orifices 11 which are adjacent to it by an angular gap whose value is between two (or even three ) and ten times the angular extent of the orifice 11.
• This separation makes it possible to have axial unit flows sufficiently spaced from each other to allow good suction of the secondary air present in the hearth around the tube 8, while having enough axial unit air flow.
• the outlet orifices 11 are shaped so that the speed of the outgoing air is between 150 and 350 m / s, and preferably between 180 and 250 m / s (or even between 200 and 250 m / s). , in operating mode.
• each channel 10 of the first series has a convergent conical shape from upstream to downstream and has an outlet port 11 having a circular cross-section.
• Each channel 10 of the first series comprises a progressive reduction portion 12 (here of conical shape) which makes it possible to pass from the continuous annular space situated between the two tubes 8, 9 delimiting the first external conduit 6, upstream of the channels 10 of the first series, to the outlet port 11 of these channels.
• the value of the average half-angle at the apex of the conical reduction portion 12 is about 30 °.
• each channel 10 of the first series comprises, between its outlet orifice 11 and the reduction portion 12, a conical portion of acceleration 13 which makes it possible to have axial unit air flows resulting in less return of air near the front of the burner 1 and to avoid any air separation from the circular perimeter of the orifice output 11, which would cause a micro-wave ring. This therefore reduces the risk of deposition of dust around the outlet ports 11 which could cause their obstruction more or less important.
• the value of the half-angle at the apex of the conical acceleration portion 13 is between 3 ° and 12 ° (preferably close to 7 °).
• the second outer pipe 7 is delimited by two tubes 9, 14 which are axially movable relative to each other (an outer tube 9 and an inner tube 14). In this case, the two external ducts 6, 7 are separated from each other only by a common tube 9 which is the tube internally delimiting the first external duct 6 and externally the second external duct 7.
• the tube 14 internally defining the second external pipe 7 carries, at its downstream end, immovably, a second series of channels 15 open towards the tube 9 externally defining the second outer pipe 7, each channel 15 having an outlet 16 coming into the home.
• each channel 15 of the second series has, relative to the axis of the burner 1, a tangential deflection which decreases from its upstream end to its downstream end.
• the tube 9 externally defining the second outer pipe 7 (here, the middle tube 9) is shaped so that it comprises a cylindrical covering portion 17 which covers the open channels of the second series on a plus or minus long, according to the relative axial position of the two tubes 9, 14 delimiting the second outer pipe 7.
• the covering portion 17 is in the immediate vicinity of the channels 15 of the second series so that the almost all of the air leaving the second external pipe 7 passes through these channels 15, a very small proportion coming out of the gap between the two tubes 9, 14 (gap allowing a necessary clearance between the two tubes 9, 14 allowing them relative axial displacement without friction).
• almost all of the air circulating in the external ducts 6, 7 comes out of the two series of channels 10, 15.
• a sealing arrangement 30 (in this case, a metal O-ring 30) is located between the two tubes 9, 14 delimiting the second outer pipe 7 of FIG. so that all the air flowing in this pipe 7 comes out only through the channels 15 of the second series.
• the sealing device 30 is disposed in an annular groove formed in the covering portion 17.
• the tube 9 externally defining the second external pipe 7 also comprises, in the downstream extension of the cylindrical covering portion 17, a driving portion 18 which is radially divergent from its upstream end (which is the downstream end of the lap portion 17) at its downstream end.
• the tangential deflection angle of the air at the downstream end of the second external pipe 7 depends on the relative axial position of the driving portion 18 with respect to the channels of the second series of which the Tangential deflection angle varies from their upstream end to their downstream end.
• the axial position of the downstream end of the cover portion 17 (and the upstream end of the drive portion 18) determines the effective output area 16a of the channels 15 of the second set.
• the driving portion 18 is tapered fixed angle and its average half-angle at the vertex is at most equal to 30 °, and preferably at most equal to 20 °.
• the distance separating, edge to edge, two channels 15 of the second series measured on the circumference of their periphery, is at most equal to 6 mm.
• the output cross sections 16a of the channels 15 of the second series are upstream of the outlets 11 of the channels of the first series 10.
• the two external pipes 7, 8 are supplied with air in common.
• the upstream end of the adjacent tube 9 is located downstream of the upstream end of each of the other two tubes 8, 14 delimiting the two external ducts 6, 7 so that they delimit a single upstream pipe 20 feeding.
• the intermediate tube 9 extends upstream like the other two tubes 8, 14 delimiting the two outer conduits 6, 7.
• the adjoining tube 9 is formed by a downstream structure 31 (a tube) which carries the channels 10 of the first series, and by an upstream structure 32 (a tube) extending and covering the downstream structure 31.
• the upstream structure 32 extends upstream substantially to the upstream end of the other two tubes 8, 14 which delimit the two outer conduits 6, 7.
• the overlap of the two structure 31, 32 allows to compensate for expansion by their relative axial displacement.
• the adjacent tube 9 also comprises a sealing device 33 (here, a metal O-ring 33) located between the two structures 31, 32.
• the sealing device 33 is disposed in an annular groove formed in the upstream structure 32.
• the burner 1 in order to have a cooling of the downstream end of the first external pipe 6 at the interstices between 10 of the first series, the burner 1 comprises a deflector 21 which forms a baffle.
• This baffle makes it possible, by partly masking the direct entry of air into the portion 12 of the channels 10, to circulate a portion of the air flowing in the first external duct 6 along the annular wall 23 in which are made the inlet ports of the channels 10 of the first series.
• the deflector 21 is stationary relative to the annular wall 23.
• the deflector 21 is formed by a series of obstruction walls 21 which are arranged upstream, at a distance and in front of each other. channels 10 of the first series. Moreover, as illustrated in FIG.
• the flame stabilizer 3 is mounted to slide axially relative to a peripheral tube 50 which delimit externally the central air supply pipe 2.
• the inner downstream end 51 of this peripheral tube 50 and the peripheral rim 52 of the flame stabilizer 3 delimit an annular passage 60.
• at least one of these two surfaces 51, 52 defining it is tapered (here, it is the inner downstream end 51 of the peripheral tube 50).
• at least one of the two surfaces 51, 52 delimiting the annular passage 60 has deflection members (in this case, inclined grooves) conferring a tangential component to the fluid passing through the annular passage 60 (here, it is the peripheral rim 52 of the flame stabilizer 3).
• the angle of inclination of the grooves is between 5 and 60 ° with respect to the axis of the burner 1.
• the central tube 55 defining the pipe fuel supply station 4 is axially integral with the flame stabilizer 3.
• the outlet orifices 16 of the channels of the second series are upstream of the outlet orifices of the channels of the first series.
• the distribution of the outlet orifices 11 of the channels of the first series to have a somewhat modified regularity, these orifices thus being able to be grouped by two or three.
• This particular arrangement is of aerodynamic interest to further favor the good aspiration of the secondary air present in the hearth around the tube 8, while reducing the maximum distance between the two orifices furthest away, and, therefore, by reducing the risk of dust deposits on the downstream wall burner.
• the angular gap separating two adjacent outlet orifices belonging to two different groups is between two (or even one and a half times in the case of a group of three orifices) and ten times the angular extent of the orifice.
• the gap separating two adjacent outlets belonging to the same group is at most equal to the angular extent of the orifice.
• a central pipe receiving an ignition burner is disposed in the central air supply pipe 2.
• the tube externally delimiting the second external duct to comprise, in the downstream extension of the driving portion 18, a cylindrical rectifying portion whose upstream end would form the downstream end of the driving portion 18. and whose downstream end would form the downstream end of the tube.
• This cylindrical portion serves to attenuate the diverging radial component of the air flow at the outlet of the second external duct and thus to limit the premature mixtures between the two air flows coming from the two external ducts.
• the drive port 18 to have a gradual divergence with the top half-angle increasing from upstream to downstream. Thus this half-angle could be less than 12 ° at its upstream end and increase gradually without exceeding, at its downstream end, 25 °.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Pre-Mixing And Non-Premixing Gas Burner (AREA)
• Gas Burners (AREA)
• Air Supply (AREA)

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• 2008
  • 2008-04-28 FR FR0852836A patent/FR2930626B1/fr active Active
• 2009
  • 2009-04-07 CN CN200980115151.9A patent/CN102016413B/zh active Active
  • 2009-04-07 EP EP09742256.2A patent/EP2283277B1/de active Active
  • 2009-04-07 WO PCT/FR2009/050593 patent/WO2009136058A2/fr active Application Filing
  • 2009-04-21 CN CN2009801149631A patent/CN102016412B/zh active Active
  • 2009-04-21 WO PCT/FR2009/050733 patent/WO2009138653A2/fr active Application Filing
  • 2009-04-21 DK DK09745972.1T patent/DK2283278T3/en active
  • 2009-04-21 EP EP09745972.1A patent/EP2283278B1/de active Active
  • 2009-04-21 ES ES09745972T patent/ES2707794T3/es active Active

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