Abstract: A method for heating a furnace with a longitudinal direction and a cross plane which is perpendicular to the longitudinal direction, which furnace includes at least one heating zone heated using combustion of a fuel with an oxidant, and which furnace is further arranged with a dark zone downstream of said heated zone, to which dark zone no fuel is supplied directly. Wherein the fuel and oxidant supplied to the heating zone is substoichiometric, in that between 10% and 40% of the total oxidant for achieving stoichiometric or near stoichiometric combustion is supplied directly to the dark zone, a flue gas temperature is measured in and/or downstream of the dark zone, and the share of the total oxidant supplied to the dark zone is controlled so as not to exceed a predetermined maximum measured such temperature. The invention further relates to a method for retrofitting an existing furnace, and a furnace.

Abstract: A method is provided for heating a furnace arranged with a heating zone heated with a burner providing a flame extending in a longitudinal direction and fed with a fuel and a primary oxidant, the burner is operated with a mass relationship between the fed fuel and primary oxidant permitting less than 50% of the fed fuel to be combusted using the primary oxidant, and a respective pair of secondary oxidant lances are provided one either side of the furnace pointing into the heating zone, lancing a secondary oxidant into the heating zone downstream of the burner substantially parallel with a cross plane, such that a temperature is measured downstream of the lances and that each of the lance pairs includes an upstream, low-speed first and a downstream, high-speed second lance, wherein the amount of secondary oxidant supplied via the first lance is regulated to achieve a homogenous lateral temperature profile. A related furnace is also provided.

Abstract: A method is provided for heating a furnace arranged with a heating zone heated with a burner providing a flame extending in a longitudinal direction and fed with a fuel and a primary oxidant, the burner is operated with a mass relationship between the fed fuel and primary oxidant permitting less than 50% of the fed fuel to be combusted using the primary oxidant, and a respective pair of secondary oxidant lances are provided one either side of the furnace pointing into the heating zone, lancing a secondary oxidant into the heating zone downstream of the burner substantially parallel with a cross plane, such that a temperature is measured downstream of the lances and that each of the lance pairs includes an upstream, low-speed first and a downstream, high-speed second lance, wherein the amount of secondary oxidant supplied via the first lance is regulated to achieve a homogenous lateral temperature profile. A related furnace is also provided.

Abstract: The invention provides a process for the heat treatment of steel products, in particular of steel strips or sheets, in which the product is brought from a starting temperature to a target temperature in a booster zone having at least one burner; the burner is operated with a fuel, in particular a fuel gas, and an oxygen-containing gas which contains more than 21% oxygen; and the product is brought into direct contact with the flame generated by the burner, the air ratio ? within the flame being set as a function of the starting temperature and/or the target temperature.

Abstract: A cold rolled strip (3) of aluminum is continuously transported along a transport path where a ramp of Direct Flame Impingement (DFI) burners (1) are located, for heating the strip. The ramp (1) is located perpendicular, or substantially perpendicular, to the direction of movement of the strip (3), the DFI burners (1) are mutually located such that the whole width of the strip (3) is heated to the same, or substantially the same, temperature. The velocity of the strip (3) passing the ramp and the heating power of the burners (1) are adapted to heat treat the strip (3) such that annealing of the strip is carried out and the heat treated strip is wound to a coil (5).

Abstract: Method for combustion of a fuel uses an existing air burner (1), including a first supply opening (5) for fuel and a second supply opening (7) for air, which supply openings (5,7) open out into a combustion zone (3). The method is characterised in that a gaseous fuel with an LHV (Lower Heating Value) of less than 7.5 MJ/Nm3 is supplied through the second supply opening (7), in that an oxidant including at least 85 percent by weight oxygen is also supplied to the combustion zone (3) through a supply device for oxidant, and in that the gaseous fuel is caused to be combusted with the oxidant in the combustion zone (3).

Abstract: Device for heating metal material includes an elongated DFI burner arranged to be driven with gaseous oxidant and gaseous fuel and to be displaceable and longitudinally arranged with respect to the metal material. The burner includes longitudinal tubular vessels for fuel and for oxidant, arranged in parallel to one another and relative to the surface of the metal material. Each of these vessels has an opening through which the fuel and oxidant flow out and then converge in an ignition zone outside the respective vessels, where a flame is generated. Supply devices are arranged via a regulator to keep the pressure constant throughout the respective vessel during operation. Each of the vessels has a longitudinally displaceable piston for controlling the longitudinal extension of the flame in the longitudinal direction of the vessels.

Abstract: Method for homogenizing the heat distribution as well as decreasing the amount of NOx in combustion products when operating an industrial furnace with at least one conventional burner using air as an oxidant. An additional oxidant including at least 50% oxygen gas is caused to stream into the furnace through a lance. The total amount of oxygen supplied is balanced against the amount of fuel being supplied through the air burner. Firstly, the combination of at least 40% of the supplied oxygen is supplied through the additional oxidant, the lance is arranged at a distance from the air burner of at least 0.3 meters, and the additional oxidant streams into the furnace through the lance with at least sonic velocity, and secondly the additional oxidant is supplied only when the air burner is operated at a certain lowest power or at a higher power.

Abstract: Method for combustion of a fuel uses an existing air burner (1), including a first supply opening (5) for fuel and a second supply opening (7) for air, which supply openings (5, 7) open out into a combustion zone (3). The method is characterised in that a gaseous fuel with an LHV (Lower Heating Value) of less than 7.5 MJ/Nm3 is supplied through the second supply opening (7), in that an oxidant including at least 85 percent by weight oxygen is also supplied to the combustion zone (3) through a supply device for oxidant, and in that the gaseous fuel is caused to be combusted with the oxidant in the combustion zone (3).

Abstract: Device for heating a metal material, includes an elongated DFI burner device, arranged to be driven with gaseous oxidant and gaseous fuel and to be displaceable and longitudinally arranged with respect to the metal material. The device has supply devices for fuel and oxidant. The burner device includes longitudinal, tubular vessels for fuel and for oxidant, arranged in parallel to one another and relative to the surface of the metal material. Each vessel has one or more openings arranged along the vessel, through which the fuel and oxidant are arranged to flow out and then converge in an ignition zone outside the respective vessels, where a flame is generated. The respective supply devices are arranged via a regulator to keep the pressure constant throughout the vessel in question during operation. Each vessel has a longitudinally displaceable piston for controlling the longitudinal extension of the flame in the longitudinal direction of the vessels.

Abstract: Method for use when galvannealing a steel material (1), in which the material (1), in a first step, is preheated to a first process temperature and is coated with a layer of a liquid alloying metal (3), in a second step is further heated to a second, higher process temperature, and in a third step is kept at the second process temperature during a predetermined time period so that the alloying metal coating at least partially is caused to alloy with the steel material (1). The heating in the second step is caused to be carried out by one or several DFI burners (5).

Abstract: A cold rolled strip (3) of aluminum is continuously transported along a transport path where a ramp of Direct Flame Impingement (DFI) burners (1) are located, for heating the strip. The ramp (1) is located perpendicular, or substantially perpendicular, to the direction of movement of the strip (3), the DFI burners (1) are mutually located such that the whole width of the strip (3) is heated to the same, or substantially the same, temperature. The velocity of the strip (3) passing the ramp and the heating power of the burners (1) are adapted to heat treat the strip (3) such that annealing of the strip is carried out and the heat treated strip is wound to a coil (5).

Abstract: Method for homogenizing the heat distribution as well as decreasing the amount of NOx in combustion products when operating an industrial furnace with at least one conventional burner using air as an oxidant. An additional oxidant including at least 50% oxygen gas is caused to stream into the furnace through a lance. The total amount of oxygen supplied is balanced against the amount of fuel being supplied through the air burner. Firstly, the combination of at least 40% of the supplied oxygen is supplied through the additional oxidant, the lance is arranged at a distance from the air burner of at least 0.3 meters, and the additional oxidant streams into the furnace through the lance with at least sonic velocity, and secondly the additional oxidant is supplied only when the air burner is operated at a certain lowest power or at a higher power.

Abstract: A method for the manufacture of extended steel products. The steel product is initially contaminated by oils and by at least one of organic and inorganic particles that are suspended or dissolved in the oils. Following the shaping of the steel product by working but before the subsequent treatment of the steel product, burners emit exhaust gases that interact directly with the surface of the steel product. The burners are driven by an oxidant that contains at least 80% oxygen by weight, whereby oils that are present on the product are vaporized and combusted. The exhaust gases interact with the surface of the steel product with a speed that is sufficiently high to blow away organic and/or inorganic particles from the surface of the steel product.

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.

Abstract: The invention provides a process for the heat treatment of steel products, in particular of steel strips or sheets, in which the product is brought from a starting temperature to a target temperature in a booster zone having at least one burner; the burner is operated with a fuel, in particular a fuel gas, and an oxygen-containing gas which contains more than 21% oxygen; and the product is brought into direct contact with the flame generated by the burner, the air ratio ? within the flame being set as a function of the starting temperature and/or the target temperature.

Abstract: Method for measuring the local temperature in an industrial furnace (1) equipped with a burner (3), where at least two temperature sensors (21, 22) are arranged at different locations in the furnace (1). A virtual temperature measuring point is created by the association of each temperature sensor (21, 22) with a certain weight factor, in that the measurement values from each temperature sensor (21, 22) are weighted together using these weight factors in order to thus achieve a virtual measurement value, in that the weight factors at every given point in time are individually controlled based upon the momentarily emitted power of the burner (3), and in that the virtual measurement value in turn constitutes control parameter for the control of the emitted power of the burner (3).

Abstract: A method for the manufacture of extended steel products. The steel product is initially contaminated by oils and by at least one of organic and inorganic particles that are suspended or dissolved in the oils. Following the shaping of the steel product by working but before the subsequent treatment of the steel product, burners emit exhaust gases that interact directly with the surface of the steel product. The burners are driven by an oxidant that contains at least 80% oxygen by weight, whereby oils that are present on the product are vaporized and combusted. The exhaust gases interact with the surface of the steel product with a speed that is sufficiently high to blow away organic and/or inorganic particles from the surface of the steel product.

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.