Patent ID: 7837928

Claim:
A tuyere assembly for directing air and at least one fluid hydrocarbon into a cavity in a blast furnace, the tuyere assembly comprising: a blowpipe portion comprising an inward end thereof and a conduit defining a bore, the blowpipe portion being adapted for directing said air through the bore to the inward end; a tuyere comprising an upstream opening adjacent to the inward end and a downstream opening, the upstream and downstream openings being connected by a chamber defined by at least one wall thereof, the downstream aperture being in fluid communication with the cavity of the blast furnace; the chamber of the tuyere and the bore of the blowpipe portion forming an internal cavity of the tuyere assembly; at least one injector subassembly comprising at least one outlet end; a nozzle positioned at said at least one outlet end, for directing said at least one fluid hydrocarbon into the internal cavity for combustion of said at least one fluid hydrocarbon to provide a flame having a preselected flame configuration; said at least one injector subassembly comprising an internal tube defining an internal tube bore therein and an annulus therearound, the internal tube being in fluid communication with an axial aperture in the nozzle, said at least one injector subassembly being adapted for directing a first fluid hydrocarbon through the annulus and a second fluid hydrocarbon through the tube to exit at the nozzle such that the first and second hydrocarbons are mixed together as they are directed into the internal cavity to provide the flame; and said at least one injector subassembly additionally comprising a plurality of injector units, each said injector unit comprising one of the outlet ends, and each said injector unit being at least partially disposed in the conduit and positioned for directing said at least one fluid hydrocarbon into the internal cavity to provide a flame having a preselected flame configuration spaced apart from said at least one wall of the tuyere, to avoid direct impingement of the flame on said at least one wall.