Patent ID: 9651253
Date: 2017-05-16
CPC Classifications: F23C,F23L,F23N,Y02E

Claim:
1. A combustion apparatus including an air fired and oxyfuel fired boiler for generating steam, comprising: a combustion chamber; at least one axial swirl pulverized coal burner provided at the combustion chamber; a primary fuel input conduit connected to the at least one axial swirl pulverized coal burner and configured to supply a pulverized coal fuel to the at least one axial swirl pulverized coal burner; a secondary input conduit, separate and distinct from the primary fuel input conduit, which is connected to the at least one axial swirl pulverized coal burner and configured to supply a combustion gas to the at least one axial swirl pulverized coal burner; combustion gas supply means including an air supply and a substantially pure oxygen supply; an air separation unit configured to separate oxygen from an ambient air feed in order to supply the substantially pure oxygen to the combustion gas supply means, and wherein the combustion gas supply means is configured to variably supply the substantially pure oxygen to both the primary fuel input conduit and the secondary input conduit upstream to the burner; and a flue gas recirculation conduit fluidly connected to and configured to supply a recirculated flue gas to at least the primary fuel input conduit and the secondary input conduit upstream to the burner; wherein the combustion gas supply means is configured to switchably supply one of air, in a first mode of operation, and a mixture of the substantially pure oxygen and a second gas comprising the recirculated flue gas, in a second mode of operation, to both of the primary fuel input conduit and the secondary input conduit, so that the combustion gas supply means controls the burner to switch between the first mode and the second mode.