Patent ID: 8689562

Claim:
A combustion apparatus for use with a fuel staging method wherein proportions of fuel at a plurality of fuel introduction points within said combustion apparatus are varied in accordance with power requirements, said combustion apparatus comprising: (a) a plurality of trapped vortex combustion (TVC) cavities; (b) a premixer in combination with said plurality of TVC cavities, said premixer comprises an inlet premixer and a plurality of vortex premixers; (c) said inlet premixer comprises a main inlet, said main inlet originating a main flow through said combustion apparatus, and a plurality of concentric, coplanar, aerodynamically shaped ring elements positioned upstream of said plurality of TVC cavities, axially aligned within a flow path, each said ring element having an interior passage for fuel, each said ring element further comprising a plurality of fuel injection orifices whereby fuel flows from said interior passage into the inlet fluid flow proximate to said ring, and wherein each pair of said ring elements defines an annular passage therebetween; (d) at least one of said plurality of vortex premixers is attached to at least one of said plurality of TVC cavities, wherein said at least one of said plurality of vortex premixers comprises a fuel inlet, an air inlet, a chamber wherein fuel and air are mixed, and an outlet for the fuel and air mixture, said fuel inlet including a fuel manifold with a diffusion plate disposed therein; and wherein said fuel and air mixture is introduced directly into said at least one of said plurality of TVC cavities in a direction tangential to a recirculation flow within said at least one of said plurality of TVC cavities; and wherein the flow of fuel through each of said plurality of vortex premixers is independently variable; (e) a conical bluff body located directly downstream of said inlet premixer and upstream of said plurality of TVC cavities, configured to provide a nozzle and accelerate a premixed mixture exiting said inlet premixer.