초록 ▼

A method of low-NOx combustion and a burner device for effecting the same, in which a primary fuel is injected in a direction from tile periphery of stream of a combustion air towards that same combustion air, effecting a first combustion, so as to create a generally cylindrical primary flame coveri

A method of low-NOx combustion and a burner device for effecting the same, in which a primary fuel is injected in a direction from tile periphery of stream of a combustion air towards that same combustion air, effecting a first combustion, so as to create a generally cylindrical primary flame covering the combustion air, whereby a secondary fuel injected towards the combustion air is shielded or intercepted by such primary flame from the combustion air, while causing NOx in tile primary flame to be reduced by the secondary fuel, after which, a second combustion is effected by bringing the secondary fuel to contact with a portion of the combustion air penetrating through the primary flame, at a downstream side. This arrangement permits more positive decrease of NOx density in an exhaust gas.

대표청구항 ▼

A burner device for a low-NOx combustion in a two-stage manner for a furnace, said burner device comprising: burner throat means for creating a flame and having an inner wall with a central axis and an exit end facing into an inside of the furnace; means for injecting a body of combustion air in a d

A burner device for a low-NOx combustion in a two-stage manner for a furnace, said burner device comprising: burner throat means for creating a flame and having an inner wall with a central axis and an exit end facing into an inside of the furnace; means for injecting a body of combustion air in a downstream direction into said burner throat means and through said exit end, into the furnace, said burner throat being substantially unobstructed to provide a linear flow of air therethrough; first fuel injection means for injecting a primary fuel into burner throat means and around a periphery of said body of combustion air, said first fuel injection means being structured and positioned on the inner wall of said burner throat means and at a location spaced upstream from said exit end by a distance which is selected to create a primary flame in said burner throat means which is confined to the periphery of the body of combustion air and which expands from said exit end into the furnace, said first fuel injection means being further structured and positioned in said burner throat means so that said primary fuel flows in contact only with the periphery of the body of combustion air to mix only with an outer layer of the combustion air for subjecting said primary fuel to a first combustion in such a way that the primary flame is formed into a shape conforming to said inner wall of said of said burner throat means, and circumscribing the body of combustion air in a downstream direction toward the inside of the furnace to leave an unmixed portion of said body of combustion air which penetrates downstream through said primary flame into the furnace, NOx being generated in said primary flame, said first fuel injection means further having an injection axis oriented substantially along the central axis of said burner throat means; and secondary fuel injection means structured and positioned for injecting a secondary fuel around an outer periphery of the primary flame, said secondary fuel injection means being at a location adjacent said exit end of said burner throat means and spaced from the location of said first fuel injection means so that said secondary fuel flows in contact with the primary flame to positively deoxidize the NOx which was generated in said primary flame, and said secondary fuel injection means being further structured and positioned for thereafter subjecting said secondary fuel to a second complete combustion with the unmixed portion of said body of combustion air which penetrated downstream through said primary flame into the furnace, thereby creating a secondary flame in the furnace at a second stage of combustion; said first and secondary fuel injection means being further structured so that at said first combustion, said body of combustion air is initially covered by said primary flame upstream a location where said secondary fuel is injected, so that said secondary fuel, immediately after being injected toward said combustion air, is intercepted by said primary flame and shielded from said unmixed portion of said body of combustion air and then, at the second stage of combustion, through operation and structure of said second fuel injection means, said secondary fuel is firstly contacted with said primary flame covering said combustion air, to thereby positively deoxidize NOx generated in said primary flame, while said injected secondary fuel is further contacted with the unmixed portion of said combustion air penetrating through said primary flame so as to create said secondary flame.