Patent ID: 8920159

Claim:
An apparatus for combining recycled flue gas, oxygen, and fuel to produce an ignitable fluid to be burned in a burner, the apparatus comprising a primary oxygen supply tube, a fuel supply tube formed to include a fuel transport passageway and oxygen-injection holes opening into the fuel transport passageway, the fuel supply tube being arranged to extend into the primary oxygen supply tube to form an oxygen flow passage therebetween to communicate a primary stream of oxygen flowing in the oxygen flow passage through the oxygen-injection holes formed in the fuel supply tube to mix with fuel conducted through the fuel transport passageway prior to combustion to produce a combustible oxygen-fuel mixture, and flue-gas recycling means for combining a secondary stream of oxygen and a first stream of recycled flue gas to flow in a first recycled flue gas passage that is separated from the oxygen flow passage to produce a first stream of oxygen-enriched flue gas separately from the combustible oxygen-fuel mixture and for combining the first stream of oxygen-enriched flue gas and the combustible oxygen-fuel mixture to produce an ignitable fluid in a flame chamber arranged to communicate with the fuel transport passageway and the first recycled flue gas passage, and wherein each of the combustible oxygen-fuel mixture and the first stream of oxygen-enriched flue gas has an oxygen concentration that is different than 20.9% and the oxygen concentration of the ignitable fluid is 20.9%.