Patent ID: 8246343

Claim:
A method for generating heat energy, comprising: flowing a primary gas stream through a conduit in which is disposed a mixer, wherein a shield with open upstream and downstream ends extends along the conduit that tapers outwardly in the direction of the flow of the primary gas stream to define a tapered, converging passage between an outer surface of the shield and an inner surface of the conduit; injecting a stream having a concentration of at least 50% oxygen (O 2 stream) into the primary gas stream through the mixer, the mixer discharging the O 2 stream as two or more spaced jets traversing the primary stream, thereby enriching the primary gas stream; mixing fuel with the enriched primary gas stream, thereby forming a fuel stream; combusting the fuel stream, thereby forming a flue gas stream; and recycling a substantial portion of the flue gas stream, thereby forming a recycled flue gas stream (RFG), wherein the primary gas stream is fed by the RFG stream.