Abstract: A method for preheating metal pellets before charging into a melting furnace, wherein the pellets are transported by a conveyor belt to a chute and discharged from the chute into the melting furnace, the method including heating the pellets by direct flame impingement from two or more banks of burners, wherein the two or more banks of burners comprise an upstream bank of burners and a downstream bank of burners; and controlling the upstream bank of burners to operate oxygen-rich so as to create an oxidizing zone and the downstream bank of burners to operate fuel-rich so as to create a reducing zone.

Abstract: A tuyere comprising an inner tube including a lower section having a first diameter, an upper section having a second diameter smaller than the first diameter, and a converging transition section having a converging angle ? from 30° to 60° connecting the lower section to the upper section, the inner tube terminating in an inner nozzle at a downstream end of the upper section; and an outer tube surrounding the inner tube so as to create an annulus there between, the outer tube including a lower section having a third diameter larger than the first diameter, an upper section having a fourth diameter smaller than the third diameter but larger than the second diameter, and a converging transition section having connecting the lower section to the upper section, the outer tube terminating in an outer nozzle at a downstream end of the upper section.

Abstract: A system for melting a pelleted charge material including a furnace having a feed end configured to receive a solid pelleted charge material and a discharge end opposite the feed end configured to discharge a molten charge material and a slag, a conveyor configured to feed the pelleted charge material into the feed end of the furnace, at least one oxy-fuel burner positioned to direct heat into a melting zone near the feed end to heat and at least partially melt the pelleted charge material to form the molten charge material and slag, wherein the oxy-fuel burner uses an oxidant having at least 70% molecular oxygen, and at least one flue for exhausting burner combustion products from the furnace.

Abstract: A tuyere comprising an inner tube including a lower section having a first diameter, an upper section having a second diameter smaller than the first diameter, and a converging transition section having a converging angle ? from 15° to 35° connecting the lower section to the upper section, the inner tube terminating in an inner nozzle at a downstream end of the upper section; and an outer tube surrounding the inner tube so as to create an annulus there between, the outer tube including a lower section having a third diameter larger than the first diameter, an upper section having a fourth diameter smaller than the third diameter but larger than the second diameter, and a converging transition section having connecting the lower section to the upper section, the outer tube terminating in an outer nozzle at a downstream end of the upper section.

Abstract: A method of operating a BOF bottom stir tuyere having an inner nozzle surrounded by an annular nozzle, including during a hot metal pour phase and a blow phase, flowing an inert gas through both nozzles; during a tap phase, initiating a flow of a first reactant through the inner nozzle and a flow of a second reactant through the annular nozzle, and ceasing the flow of inert gas through the nozzles, wherein the first and second reactants includes fuel and oxidant, respectively, or vice-versa, such that a flame forms as the fuel and oxidant exit the tuyere; during a slag splash phase, continuing the flows of fuel and oxidant to maintain the flame; and after ending the slag splash phase and commencement of another hot metal pour phase, initiating a flow of inert gas through both nozzles and ceasing the flows of the first and second reactants.

Abstract: A system for melting a pelleted charge material including a furnace having a feed end configured to receive a solid pelleted charge material and a discharge end opposite the feed end configured to discharge a molten charge material and a slag, a conveyor configured to feed the pelleted charge material into the feed end of the furnace, at least one oxy-fuel burner positioned to direct heat into a melting zone near the feed end to heat and at least partially melt the pelleted charge material to form the molten charge material and slag, wherein the oxy-fuel burner uses an oxidant having at least 70% molecular oxygen, and at least one flue for exhausting burner combustion products from the furnace.

Abstract: A method of operating a BOF bottom stir tuyere having an inner nozzle surrounded by an annular nozzle, including during a hot metal pour phase and a blow phase, flowing an inert gas through both nozzles; during a tap phase, initiating a flow of a first reactant through the inner nozzle and a flow of a second reactant through the annular nozzle, and ceasing the flow of inert gas through the nozzles, wherein the first and second reactants includes fuel and oxidant, respectively, or vice-versa, such that a flame forms as the fuel and oxidant exit the tuyere; during a slag splash phase, continuing the flows of fuel and oxidant to maintain the flame; and after ending the slag splash phase and commencement of another hot metal pour phase, initiating a flow of inert gas through both nozzles and ceasing the flows of the first and second reactants.

Abstract: A direct flame impingement system for preheating metal pellets before charging into a melting furnace, wherein the pellets are transported by a conveyor belt to a chute discharging into the melting furnace, including a refractory-lined preheater hood including a chute hood covering the chute and a conveyor hood covering at least a portion of the conveyor belt, the preheater hood having an entrance end through which pellets enter and an exit end through which pellets exit toward the melting furnace, and at least one bank of burners each containing at least one burner disposed in the hood positioned to direct flames into contact with the pellets being transported to preheat the pellets prior to discharge into the melting furnace.

Abstract: An oxy-fuel furnace and method of heating material in an oxy-fuel furnace are disclosed. The method includes combusting oxygen and fuel with an oxy-fuel burner arrangement in the oxy-fuel furnace forming combustion gases, and maintaining a vortex including the combustion gases within a central region of an enclosure of the oxy-fuel furnace. The oxy-fuel burner arrangement includes a plurality of high momentum oxy-fuel burners arranged at an angle to generate the vortex, the angle being greater than 15 degrees but less than 75 degrees with respect to a furnace wall boundary of the enclosure, an angular velocity of greater than 0.07 radians per second, or a combination thereof. The furnace includes an oxy-fuel burner arrangement including at least two high momentum oxy-fuel burners having high shape factor nozzle geometries, and an enclosure. The vortex increases convective heating within the enclosure and uniformity of heating within the enclosure.