Method of and burner for burning liquid or gaseous fuels with decreased NO.sub.x formation
AssigneeDeutsche Babcock Werke Aktiengesellschaft
InventorsRolf Oppenberg, Helmut Wiehn
Life of this patent
Estimating the term…
Abstract
To allow liquid and/or gaseous fuels to be burned with decreased NO.sub.x formation, the combustion air is fed in at axial intervals one after the other. The percentage of primary air is higher than that of secondary air. The injector effect of the primary air draws flue gas out of the firebox and supplies it to a flame-initiation point between the primary-air and secondary-air feeds.
Claims24
Method of burning liquid or gaseous fuels in a firebox with reduced formation of NO.sub.x, comprising the steps of:
- supply combustion air in portions or primary and secondary air;
- feeding said portions in one after the other at axial intervals parallel to flow of combustion gaees, said primary air generating an injector effector for drawing combustion gases in, said primary air being supplied at a percentage of the total combustion air that is higher than that of the secondary air;
- and drawing out extensively burned combustion gases from the firebox and conducting to a flame-initiation point between primary-air and secondaryrair feeds;
- said primary air being supplied swirled.
Method of burning liquid or gaseous fuels in a firebox with reduced formation of NO.sub.x, comprising the steps of:
- supplying combustion air in portions of primary and secondary air;
- feeding said portions in one after the other at axial intervals parallel to flow of combustion gases, said primary air generating an injector effect for drawing combustion gases in, said primary air being supplied at a percentage of the total combustion air that is higher than that of the secondary air;
- and drawing out extensively burned combustion gases from the firebox and conducting to a flame-initiation point bstween primary-air and secondary-air feeds;
- said primary air being supplied partly parallel to the axis and partly swirled.
Method of burning liquid or gaseous fuels in a firebox with reduced formation of NO.sub.x, comprising the steps of:
- supplying combustion air in portions of primary and secondary air;
- feeding said portions in one after the other at axial intervals parallel to flow of combustion gases, said primary air generating an injector effect for drawing combustion gases in, said primary air being supplied at a percentage of the total combustion air that is higher than that of the secondary air;
- and drawing out extensively burned combustion gases from the firebox downstream of the feeding of said secondary air and conducting to a flame-initiation point between primary-air and secondary-air feeds, so that said burned combustion gases produce a gaseous separating layer between said primary air and said secondary air, said gaseous layer being comprised of substantially inert combustion gas and delaying access of the secondary air to said flame-initiation point for delaying combustion with reduced formation of NO.sub.x.
Burner for burning liquid or gaseous fuels with reduced formation of NO.sub.x, comprising:
- a burner having a mouth;
- lances extending through an air box;
- a cover plate for separating said air box from said mouth;
- a first supply pipe surrounding said lances;
- said first supply pipe extending through said cover plate and having a entrance inside air box and an exit in said mouth of the burner;
- a second supply pipe positioned inside said mouth of said along an axis of said burner;
- said second supply pipe being axially separated from the exit of said first supply pipe and being surrounded by a third supply pipe that is radially separated from a wall of the mouth of the burner an axially separated from said cover plate of the air box;
- and an annular channel between the second and third supply pipe communicating with the air box through connecting pipes.
Dependencies are inferred from the claim text.