One object of the present invention is to provide a burner which makes it possible to prevent blockage and damage of the nozzle by the molten metal and the slag, and the present invention provides a burner including a combustion supporting gas supply passage which is configured to supply a combustion supporting gas toward a combustion supporting gas outlet provided at the center of the tip end side; a fuel supply passage which is configured to supply a fuel toward a fuel ejection outlet provided around the combustion supporting gas outlet; and a protective nozzle provided from a position surrounding a periphery of the fuel ejection outlet so as to project forward beyond the tip end surface at which the combustion supporting gas ejection outlet and the fuel ejection outlet are provided; wherein the combustion supporting gas supply passage includes a Laval nozzle, and a diameter-enlarged nozzle of which a diameter gradually increases from the tip end of the Laval nozzle toward the combustion supporting gas ejection outlet, and the protective nozzle has a shape which is gradually reduced in diameter forward from the tip end surface.

A gas injection system includes a tubular wall 3 capable of being thermally stressed and having a proximal extremity and a distal extremity 11, at the distal extremity, at least one extremity opening through which at least one gas is projected. A cooling is system located in the tubular wall including axial channels 12 which extend axially towards the distal extremity and in which a cooling fluid is circulated. Connecting channels 13 circumferentially join the axial channels to each other at the distal extremity of the tubular wall. The connecting channels, which circumferentially join the axial channels at the distal extremity of the tubular wall, have a rounded shape in the direction of the distal extremity.

A gas injection system includes a tubular wall 3 capable of being thermally stressed and having a proximal extremity and a distal extremity 11, at the distal extremity, at least one extremity opening through which at least one gas is projected. A cooling is system located in the tubular wall including axial channels 12 which extend axially towards the distal extremity and in which a cooling fluid is circulated. Connecting channels 13 circumferentially join the axial channels to each other at the distal extremity of the tubular wall. The connecting channels, which circumferentially join the axial channels at the distal extremity of the tubular wall, have a rounded shape in the direction of the distal extremity.

A method for heating a furnace (40) used for metal processing by combusting a fuel in the furnace (40) by supplying an oxidizing gas through an oxidizing gas supply line (20) into the furnace (40) and by supplying a fuel through a fuel supply line (30) into the furnace (40), wherein the oxidizing gas is supplied in form of a central oxidizing gas flow (24) together with a first shroud gas flow (25), and/or the fuel is supplied in form of a central fuel flow (34) together with a second shroud gas flow (35), and to a corresponding burner (10).

One object of the present invention is to provide a burner which makes it possible to prevent blockage and damage of the nozzle by the molten metal and the slag, and the present invention provides a burner including a combustion supporting gas supply passage which is configured to supply a combustion supporting gas toward a combustion supporting gas outlet provided at the center of the tip end side; a fuel supply passage which is configured to supply a fuel toward a fuel ejection outlet provided around the combustion supporting gas outlet; and a protective nozzle provided from a position surrounding a periphery of the fuel ejection outlet so as to project forward beyond the tip end surface at which the combustion supporting gas ejection outlet and the fuel ejection outlet are provided; wherein the combustion supporting gas supply passage includes a Laval nozzle, and a diameter-enlarged nozzle of which a diameter gradually increases from the tip end of the Laval nozzle toward the combustion supporting gas ejection outlet, and the protective nozzle has a shape which is gradually reduced in diameter forward from the tip end surface.

Burner for an oven for reheating siderurlogical products such as billets, blooms or slabs, or for heat treatment oven, which is equipped with a fuel injection device and with an oxidant feed body feeding feed orifices with oxidant, the burner having an axial direction; the injection device is designed to provide a central injection of fuel via an orifice in, or parallel to, the axial direction of the burner; the oxidant feed body includes two sets of four oxidant feed orifices, each set including two orifices situated above a horizontal plane passing through the axial direction of the burner, and two orifices situated below this plane, the orifices of a second set being further away from the horizontal plane than those of the first set, the geometric axes of the orifices of the two sets making angles of inclination with respect to the axial direction of the burner.

Burner for an oven for reheating siderurlogical products such as billets, blooms or slabs, or for heat treatment oven, which is equipped with a fuel injection device and with an oxidant feed body feeding feed orifices with oxidant, the burner having an axial direction; the injection device is designed to provide a central injection of fuel via an orifice in, or parallel to, the axial direction of the burner; the oxidant feed body includes two sets of four oxidant feed orifices, each set including two orifices situated above a horizontal plane passing through the axial direction of the burner, and two orifices situated below this plane, the orifices of a second set being further away from the horizontal plane than those of the first set, the geometric axes of the orifices of the two sets making angles of inclination with respect to the axial direction of the burner.

An object of the present invention is to provide a combustion burner which is capable of heating or melting a raw material powder efficiently by dispersing the raw material powder, and which is capable of improving a collection rate of the heated or melted raw material powder, the invention providing a combustion burner that forms flame including a dispersal member which is provided in the raw material powder outlet which spouts the raw material powder into the flame, includes first and second inclined surfaces, and which disperses the raw material powder by colliding with the raw material powder that is supplied to the raw material powder outlet.