Apparatus and process for control of nitric oxide emissions from combustion devices using vortex rings and the like

An improved apparatus for reducing nitrogen oxide in the flue gas of a furnace wherein a fuel is burned in a primary combustion zone and produces a flue gas containing nitrogen oxide wherein the improvement comprises:

• at least one vortex generator attached to the furnace above the primary combustion zone by means of which vortices comprised of a fluid selected from the group of fluids consisting of natural gas, C.sub.x H.sub.y compounds, and C.sub.x H.sub.y O.sub.z compounds are introduced into the flue gas wherein the vortex generator contains a piston having an adjustable piston stroke.

An improved apparatus for reducing nitrogen oxide in the flue gas of a furnace wherein a fuel is burned in a primary combustion zone and produces a flue gas containing nitrogen oxide wherein the improvement comprises:

• at least one vortex generator attached to the furnace above the primary combustion zone by means of which vortex rings comprised of a fluid selected from the group of fluids consisting of natural gas, C.sub.x H.sub.y compounds, and C.sub.x H.sub.y O.sub.z compounds are introduced into the flue gas and means for introducing into the vortex rings some flue gas with the fuel.

A method of reducing nitrogen oxide emissions in flue gas comprising the step of:

• injecting a series of vortices of a fluid selected from the group consisting of natural gas, C.sub.x H.sub.y compounds, C.sub.x H.sub.y O.sub.z compounds, and mixtures primarily of these compounds into the flue gas in sufficient quantities to promote a reaction between the nitrogen oxide in the flue gas and the fluid to form ammonia and cyanide-like compounds and N.sub.2 and to promote a secondary reaction of said ammonia and cyanide compounds and additional nitrogen oxide from the fluid gas to form N.sub.2, water and carbon dioxide.

A method of reducing nitrogen oxide emissions in flue gas comprising the step of:

• injecting a series of vortices of a fluid selected from the group consisting of natural gas, C.sub.x H.sub.y compounds, C.sub.x H.sub.y O.sub.z compounds, and mixtures primarily of these compounds into the flue gas in sufficient quantities to promote a reaction between the nitrogen oxide in the flue gas and the fluid to form ammonia and cyanide-like compounds and N.sub.2 and to promote a secondary reaction of said ammonia and cyanide compounds and additional nitrogen oxide from the flue gas to form N.sub.2, water and carbon dioxide and injecting into the vortex rings some flue gas with the fuel.

An improved apparatus for reducing nitrogen oxide in the flue gas of a furnace wherein a fuel is burned in a primary combustion zone and produces a stream of flue gas containing nitrogen oxide wherein the improvement comprises:

• means forming at least one helix generator attached to the furnace above the primary combustion zone for generating and injecting into the flue gas a helix which penetrates into the stream in a direction nonaligned with a flow of the stream of flue gas and which helix is comprised of a fluid selected from the group of fluids consisting of natural gas, C.sub.x H.sub.y compounds, and C.sub.x H.sub.y O.sub.z compounds.

A method of reducing nitrogen oxide emissions in a stream of flue gas comprising the step of:

• injecting a series of vortices of a fluid selected from the group consisting of natural gas, C.sub.x H.sub.y compounds, C.sub.x H.sub.y O.sub.z compounds, and mixtures primarily of these compounds into the flue gas in sufficient quantities to promote a reaction between the nitrogen oxide in the flue gas and the fluid to form ammonia and cyanide-like compounds and N.sub.2 and to promote a secondary reaction of said ammonia and cyanide compounds and additional nitrogen oxide from the flue gas to form N.sub.2, water and carbon dioxide, the helix penetrating the stream of flue gas in a direction nonaligned with a flow of the stream of flue gas.