摘要 |
A system of this invention reduces the emission of NOx and fuel pollutants from a furnace. The system includes a furnace with a chamber for combusting air, oxygen and fuel flows in an approximately stoichiometric proportion. A reburn unit, that can be a port, is coupled to communicate with and receive the combustion exhaust from the chamber. The reburn unit is also coupled to receive a second fuel flow that is added to the exhaust flow at a stoichiometric ratio and temperature at which a reaction occurs to lower the amount of NOx in the exhaust flow. The reburn unit is coupled to a burnout unit that can be a regenerator or a recuperator, that is coupled to receive an oxidant flow with air and/or oxygen. The oxidant flow combusts fuel in the exhaust flow to prevent emission of this fuel into the atmosphere. To cool the exhaust from the regenerator or recuperator so that it is not reactive, a conduit in which the exhaust flows from the burnout unit can be coupled to receive a coolant flow of air and/or oxygen. A stack or flue is coupled to receive the exhaust flow from the burnout unit. Conduits through which the air and oxygen flow to the furnace combustion chamber can extend through the stack or flue to be heated by the exhaust flow before introduction to the furnace chamber. The invention also includes related methods.
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