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
  • F23D14/10—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 elongated tubular burner head
  • F23D14/105—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 elongated tubular burner head with injector axis parallel to the burner head axis
• • 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
  • F23D14/46—Details
  • F23D14/48—Nozzles
  • F23D14/58—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration
• • 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
  • F23D14/46—Details
  • F23D14/72—Safety devices, e.g. operative in case of failure of gas supply
  • F23D14/74—Preventing flame lift-off
• • 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
  • F23D14/46—Details
  • F23D14/72—Safety devices, e.g. operative in case of failure of gas supply
  • F23D14/82—Preventing flashback or blowback
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2203/00—Gaseous fuel burners
  • F23D2203/10—Flame diffusing means
  • F23D2203/102—Flame diffusing means using perforated plates
  • F23D2203/1023—Flame diffusing means using perforated plates with specific free passage areas
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2211/00—Thermal dilatation prevention or compensation

Definitions

• the invention relates to a method for operating an atmospheric, substoichiometrically premixing gas burner with an injector into which gas is blown, and with a housing which is fed by the injector and which has mixture passage openings. Furthermore, the invention is directed to a burner that can be operated by this method.
• the invention has for its object to provide a method and a burner of the type mentioned, which work with reduced pollutant emissions.
• the method according to the invention is characterized in that the area load, based on the free mixture passage cross section, is 110 to 210 W / cm 2 , preferably 130 to 170 W / cm 2 , and that the air ratio is set to 0, 7 to 0.9, preferably 0.75 to 0.85.
• the latter is promoted in a further development of the invention in that the gas emerging from the injector is distributed uniformly over the mixture passage openings.
• the air ratio preferably remains essentially unchanged when the gas supply is reduced up to approximately 50% of the nominal heat load of approximately 50%. This contributes significantly to increasing the flame stability.
• the flame speed only changes by around 20%, so that gases with different properties can be burned without further notice.
• the gas burner according to the invention which is pre-mixing in a stoichiometric manner, is provided with an injector and with a housing which is axially associated with the injector and has mixture passage openings in a wall.
• the mixture passage openings have a diameter of 0.5 to 1.2 mm, preferably approximately 0.8 mm, and are arranged hexagonally with a degree of perforation of 15 to 30%, preferably approximately 25%. This ensures according to the invention desired emission levels (optimization of CO and N0 X) with excellent conditions with respect to the flame stability and the homogeneous burnout.
• the mixture passage openings in the form of at least two perforated fields which extend in the longitudinal direction of the housing, the distance between adjacent perforated fields advantageously being 5 to 35 mm, preferably approximately 25 mm .
• the wall of the housing which has the mixture passage openings, is preferably the peripheral wall.
• the perforated fields can be formed in separate perforated strips which can be inserted into the wall of the housing without thermal stress.
• highly heat-resistant material in particular a chrome-aluminum steel, can advantageously be limited to these perforated strips.
• the paper tape in lateral, longitudinal guides of Wall of the housing can be inserted, so that on the one hand there are no installation difficulties and on the other hand a good lateral seal is guaranteed against the flames kicking back, even with thermal expansion.
• the ends of the perforated strips engage in overlapping webs. Thermal expansion, which naturally has a particularly strong effect in the longitudinal direction of the paper tape, cannot lead to leaks here either. In many cases it will be sufficient to provide the overlapping webs on the end walls of the housing. If, on the other hand, the very thin (0.5 mm) perforated strips are relatively long, uneven movements can occur under the influence of heat. In these cases, the perforated strips will be subdivided and a corresponding number of overlapping webs provided over the length of the housing.
• the assignment of housing and injector and the design of the housing are basically arbitrary. So the injector can be connected upstream of the housing.
• a particularly advantageous embodiment of the burner according to the invention is that the housing is rod-shaped and surrounds the injector.
• the injector can have a downstream, frontally closed extension with radial openings which are opposite to the mixture passage openings of the wall of the housing. This enables a particularly homogeneous mixture distribution, namely with structurally simple means. The latter applies in particular if the extension of the injector extends to an end wall of the housing.
• the combustion properties of the gas burner according to the invention can be influenced by the type of secondary air supply. It has been found to be particularly advantageous in a surrounding combustion chamber to run one below the burner parallel to the burner. to provide the secondary air slot. The secondary air is thus fed in from below over the length of the burner, flows around the burner and enters the flame carpets formed by the perforated fields from the side. The result is optimal combustion conditions.
• FIG. 1 is a plan view of a burner according to the invention.
• Fig. 2 is a section along the line II-II in Fig. 1; 3 shows an end view in the direction X in FIG. 1.
• FIG. 4 shows part of a modified embodiment in a representation corresponding to FIG. 1.
• the burner according to the invention has a rod-shaped housing 1, which surrounds an injector 2.
• a nozzle 3, which is seated on a nozzle carrier 4, is assigned to the injector.
• the latter is connected to an associated end wall 5.
• the injector has a tubular extension 6 which extends to an associated end wall 7 and is closed by the latter.
• the housing 1 is provided with mixture passage openings 8 in the upper region. These have a diameter of 0.8 mm and are arranged hexagonally with a perforation degree of 26%, whereby they form two perforated fields which extend in the longitudinal direction of the housing 1. The distance between the two perforated fields is 25 mm.
• the perforated fields are formed in separate perforated strips 9 which are inserted in the upper area of the housing 1 in its wall.
• the wall of the housing 1 forms longitudinal guides 10 into which the perforated strips 9 extend axially Direction are inserted.
• a seal is created between the perforated strips and the peripheral wall of the housing, which prevents the flame from striking back and stress cracks in the perforated strip even when thermal expansion occurs.
• the seals in the axial direction serve webs 11, which overlap the perforated strips 9. This holder is also free of thermal stress.
• the perforated strips 9 form the only parts to be machined and, in contrast to the other housing sections, consist of highly heat-resistant chrome-aluminum steel.
• the gas emerging from the injector 2 is distributed very evenly over the mixture passage openings 8.
• the extension 6 of the injector is provided with radial openings 12, but only in the area opposite the mixture passage openings 8, that is to say in the lower area.
• the burner is operated premixing under-stoichiometrically, specifically with an outlet surface load of 150 W / cm 2 and an air ratio of 0.8. It shows very favorable pollutant behavior by optimizing CO and NO x emissions on the one hand.
• the flame stability is very good and enables the combustion of gases with different properties.
• the webs 11 are only arranged on the end walls 5 and 7 of the housing 1.
• the modified embodiment according to FIG. 4 differs from this in that the perforated strips 9 are divided in the longitudinal direction, central webs 11 receiving the ends of the perforated strips 9 directed towards the center.
• This construction is recommended if the perforated strips 9 are relatively long and consist of particularly thin material with a thickness of preferably 0.5 mm. Even under these circumstances, thermal loads cannot lead to inadmissible recycling. the perforated strips 9 lead. The sealing at the abutting edges is ensured by the central webs 11.
• the burner according to the invention can be arranged in a combustion chamber, not shown, which is preferably provided with a secondary air slot arranged below the burner.
• the latter preferably extends parallel to the burner over a length that corresponds to the length of the perforated strips 9.
• the secondary air hits the housing 1 of the burner from below, flows around the housing and enters laterally into the flame carpets carried by the perforated strips 9. In this way, optimal combustion conditions result.
• the housing can be designed differently than rod-shaped. It also does not have to surround the injector, but can be connected downstream of it. It is also possible to work with three or more perforated fields or with only one perforated field, each perforated field being integrally connected to the wall of the housing. The latter also ensures a seal against the flames kicking back.

Landscapes

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

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6422632

Family Applications (1)

Country Status (4)

Cited By (5)

Families Citing this family (1)

Citations (8)

Family Cites Families (3)

• 1991
  • 1991-01-07 DE DE4100247A patent/DE4100247A1/de active Granted
  • 1991-12-19 AT AT92901135T patent/ATE168761T1/de not_active IP Right Cessation
  • 1991-12-19 WO PCT/EP1991/002454 patent/WO1992012381A1/de active IP Right Grant
  • 1991-12-19 EP EP92901135A patent/EP0519029B1/de not_active Expired - Lifetime

Patent Citations (8)

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