Abstract: A stream of hot oxygen is formed by providing a duct and a fuel lance movable axially within the duct, flowing gaseous fuel out of the lance into the duct, mixing it in the duct with gaseous oxidant, flowing the mixture out of the duct into an atmosphere which is hot enough that it ignites the mixture without aid of an ignition source other than said atmosphere, and combusting said mixture in a flame that does not extend into said duct; then moving the lance so its fuel outlet approaches the duct exit orifice so that the base of said flame moves inside said duct to the fuel outlet; and then moving the lance to draw the fuel outlet and the flame attached thereto away from the exit orifice into the duct; and increasing the flow rate of gaseous oxidant in said duct, so that combustion of fuel within the duct heats uncombusted oxygen which emerges as a stream of hot oxidant.

Abstract: A stream of hot oxygen is formed by providing a duct and a fuel lance movable axially within the duct, flowing gaseous fuel out of the lance into the duct, mixing it in the duct with gaseous oxidant, flowing the mixture out of the duct into an atmosphere which is hot enough that it ignites the mixture without aid of an ignition source other than said atmosphere, and combusting said mixture in a flame that does not extend into said duct; then moving the lance so its fuel outlet approaches the duct exit orifice so that the base of said flame moves inside said duct to the fuel outlet; and then moving the lance to draw the fuel outlet and the flame attached thereto away from the exit orifice into the duct; and increasing the flow rate of gaseous oxidant in said duct, so that combustion of fuel within the duct heats uncombusted oxygen which emerges as a stream of hot oxidant.

Abstract: A method of injecting oxygen into a melt located within a metallurgical furnace having a heated furnace atmosphere in which oxygen and fuel is injected into 1 or more nozzles having passageways of converging-diverging configuration under choked flow conditions to produce supersonic jet or jets discharged from the passageways. Fuel is injected into internal circumferential locations of the passageways so as to impart a structure to the jets being discharged that have an outer circumferential region containing a mixture of fuel and oxygen and a central region containing essentially oxygen. Such a structured jet upon discharge interacts with the furnace atmosphere to create an outer shear-mixing zone in which the outer circumferential layer mixes with the heated furnace atmosphere and auto-ignites to produce a flame envelope surrounding a supersonic jet of oxygen. The jet of oxygen and flame envelope can be directed against a melt contained within the metallurgical furnace for injection of oxygen into the melt.

Abstract: A method of injecting oxygen into a melt located within a metallurgical furnace having a heated furnace atmosphere in which oxygen and fuel is injected into 1 or more nozzles having passageways of converging-diverging configuration under choked flow conditions to produce supersonic jet or jets discharged from the passageways. Fuel is injected into internal circumferential locations of the passageways so as to impart a structure to the jets being discharged that have an outer circumferential region containing a mixture of fuel and oxygen and a central region containing essentially oxygen. Such a structured jet upon discharge interacts with the furnace atmosphere to create an outer shear-mixing zone in which the outer circumferential layer mixes with the heated furnace atmosphere and auto-ignites to produce a flame envelope surrounding a supersonic jet of oxygen. The jet of oxygen and flame envelope can be directed against a melt contained within the metallurgical furnace for injection of oxygen into the melt.

Abstract: A method for producing low carbon steel wherein molten steel is decarburized in a three stage refining procedure comprising a first stage wherein oxygen is provided for decarburization enveloped in a gas shroud, a second stage wherein oxygen is provided for decarburization enveloped in a flame shroud, and a third stage wherein inert gas or oxygen and inert gas is provided enveloped in a flame shroud.

Abstract: A method for reducing the NOx content of combustion gases from combustion in a commercial furnace wherein hot oxygen and carbonaceous fuel such as pulverized coal react to form a fuel-rich gas phase mixture which is then used to reduce NOx to nitrogen gas.

Abstract: A method for providing a blast stream into a blast furnace wherein fuel and hot oxygen are provided into the blast air, the hot oxygen being at a temperature and velocity each greater than that of the blast air, and wherein the fuel and hot oxygen begin to combust prior to passage into the blast furnace in the blast stream.

Abstract: A low NO.sub.x combustion process is carried out by reacting low concentrations of combustibles with low concentrations of oxygen. These low concentrations are obtained by injecting high velocity fuel and oxidant streams through port openings that are spatially separated.

Abstract: A method and apparatus for purging air from the interior of a container in which purge gas is supplied to the interior of the container from one or more injectors in a turbulent jet flow having a modified Reynolds number Re' of less than 14,000 and the purge gas is supplied at a flow rate to produce a positive pressure within the container of at least 2.times.10.sup.-8 atm above the ambient pressure.