Combustion process for reducing nitrogen oxides
AssigneeBabcock-Hitachi Kabushiki Kaisha
InventorsKunio Okiura, Iwao Akiyama, Hiroshi Terada, Yoshijiro Arikawa, Akira Baba, Shigeki Morita
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Abstract
A combustion process for reducing nitrogen oxides in combustors is proposed wherein combustion takes place successively forming an incomplete combustion zone, a reducing combustion zone, and a complete combustion zone, respectively corresponding to primary burners, secondary burners and air ports or after-burners, successively arranged in the direction of gas stream in a furnace. According to the present invention, it is possible to reduce nitrogen oxides by improving a manner of combustion without providing any denitrating apparatuses for exhaust gas.
Claims12
A combustion process for reducing nitrogen oxides in combustors which comprises arranging at least one primary burner, at least one secondary burner and at least one air port, successively in this order in the direction of gas stream in the hollow body of a combustor provided with a space for combustion and an exit for combustion exhaust gas;
- and burning fuels in a ratio of air to fuel less than 1 at said primary burner to form an incomplete combustion zone, burning fuels in a ratio of air to fuel lower than the above-mentioned ratio at said secondary burner to form a reducing combustion zone, and burning fuels at said air port where air is fed in excess amount required for a complete combustion of the fuels, to form a complete combustion zone, respectively, in the free space of the hollow body of the combustor.
Dependencies are inferred from the claim text.