Abstract: A method and apparatus relating to the combustion of a fuel with an oxidant in a heating furnace, wherein the fuel and the oxidant are delivered to a burner head. In a first method step fuel and oxidant are emitted from the burner head in close proximity to each other, so that combustion essentially takes place close to and at a small distance outward of the burner head, and until a temperature is reached in the furnace space that exceeds the spontaneous combustion temperature of the fuel. In a second method step the fuel and the oxidant are instead emitted from the burner head at a mutual distance apart, so that combustion takes place at a distance from the burner head corresponding to at least the diameter of the burner head and outward of the burner head.

Abstract: A method and apparatus for monitoring combustion of a fuel with an oxidant in an industrial furnace. The fuel and oxidant are supplied to a burner head, and a burner outlet flame is monitored by an ultraviolet light detector. At least one fuel channel and at least two oxidant channels are provided and open at an outer surface of the burner head that faces the interior of the furnace. The fuel channel and a first oxidant channel are located at a predetermined first distance from each other, and the fuel channel and the second oxidant channel are located closer to each other at a second distance. The detector is positioned at the fuel channel or at the second oxidant channel. A fraction of the total amount of oxidant supplied is supplied to the second oxidant channel, and oxidant is supplied to the second oxidant channel during the entire combustion process.

Abstract: A composite lance for use during the injection of gases during combustion, and a method for making such a lance. The lance has a channel through which gas flows, and it includes a core of a metallic material and a ceramic layer outside the core. The outer surface of the core includes a region having a smaller diameter bounded axially by regions each having larger diameters. The ceramic layer is positioned around the core with a gap between the outer surface of the core and the inner surface of the ceramic layer. The gap prevents the ceramic layer from cracking because of differences in thermal expansion between the core and the ceramic layer when temperature changes take place in the lance.

Abstract: A seal for burners for the combustion of fossil fuels with an oxidant gas that contains a high fraction of gaseous oxygen. The burner includes a burner body with a cylindrical opening within which a cylindrical nozzle is removably positioned. The nozzle includes axial channels for the supply of fuel and oxidant gas. One, two or more parallel annular grooves are provided in the outer peripheral surface of the cylindrical nozzle. Each groove is arranged to support a sealing ring that is split or discontinuous at one location along its periphery. Each ring is arranged to lie in contact with the inner surface of the cylindrical opening when the nozzle is mounted in the burner body, with the discontinuities of the rings circumferentially offset relative to each other.

Abstract: A method and an apparatus for heat-treatment of materials, preferably metals, are provided. The method comprises the following steps: providing and maintaining a flame by supplying a burner with fuel and gas containing at least 80 percent by volume oxygen; creating an oxygen-hot exhaust mixture by recirculating exhausts from the flame to the gas containing oxygen by means of an ejector effect; mixing the oxygen-exhaust mixture and the fuel; and providing a secondary recirculation by recirculating exhausts from the flame to the oxygen-exhaust-fuel mixture. The method and apparatus allow for extremely low NOx emissions and high efficiency, resulting in an environmentally friendly and at the same time cost effective process.

Abstract: A method of heat treating stainless steel in the form of blanks, piping, tubing, strip, or wire-like material, after rolling the material, and in a heat treatment furnace at a temperature higher than about 900° C. The material is subjected to a preheating stage and a final heating stage, wherein in the preheating stage flames from burners are directed toward the surface of the material to impinge on the surface. Burners situated in the preheating stage are supplied with a fuel that burns with the aid of an oxidizing gas that contains gaseous oxygen. The material is held in the preheating stage long enough to obtain at least some degree of oxidation on the surface of the material, and the material is heated further in a following, final heating stage by burners situated in a furnace and that are supplied with a fuel and an oxidizing gas.