Abstract: During the operation of an oxygen-fuel burner the supply of fuel is reduced to generate an oxygen-rich low velocity flame. The excess oxygen of the flame is heated by the flame and oxidizes any slag accumulated on or about the burner.

Abstract: A high velocity oxygen fuel burner (10) includes a combustor assembly (11) mounted in a graphite block (12), with the burner mounted in a water jacket (18) of a furnace. The combustor assembly includes a combustion chamber (48) that receives a stream of oxygen along its center axis (51). The fuel moves from fuel barrel (32) through fuel passages (50), with a portion of the fuel being diverted into the combustion chamber (48) by the annular fuel diverter ring (52) and with the rest of the fuel moving on through the fuel extension passages (50b) and through nozzle ring (34). The nozzle ring directs the fuel into the flame as it emerges from the combustion chamber, so that the fuel from the nozzle has a cooling effect at the exposed end of the burner and tends to develop the flame in an annular ring about the stream of high velocity oxygen that is directed toward the work product in the furnace.

Abstract: Several ladles (11-14) for receiving hot metals are preheated by applying a lid (40, 42) to the rim of each ladle and directing an open flame through the lid into the ladle. The hot exhaust gases move back through the lid and through a heat exchanger (35-38) to heat the oncoming combustion air, and the exhaust gases from the ladles being preheated are combined and directed through a lid (41) applied to a ladle at a drying station to dry the ladle.

Abstract: An oxygen-fuel burner of the rocket burner type includes a graphite burner block for direct exposure to the interior of a furnace, and a cylindrical combustion chamber formed through the hot face of the burner block and extending into the burner block. An oxygen supply conduit delivers oxygen to the combustion chamber along the center line of the combustion chamber and fuel supply ducts deliver fuel to the combustion chamber at the concave surface of the combustion chamber. A plurality of rectilinear cooling bores extend into the burner block and are arranged in a parallel array about the combustion chamber. A liquid coolant header moves cooling liquid through a plurality of parallel supply tubes which are telescopically received within the cooling bores, thereby maintaining the burner block at a reduced temperature. The nozzle that supplies the oxygen to the combustion chamber is movable along the length of the combustion chamber so as to change the shape of the flame emitted from the burner.

Abstract: A pair of burner tubes are arranged in concentric relationship. Fuel and air in a rich fuel-air ratio is provided to the central burner tube, and fuel and air in a lean fuel-air ratio is provided to the outer burner tube. The rich combination of fuel and air is partially burned at a temperature of about 2,500.degree. F. while the lean combination of fuel and air is burned at a temperature of less than 2,800.degree. F., and the flames from the burner tubes are mixed at the ends of the burner tubes to form a final flame envelope and to finish the combustion of the rich mixture. Exhaust gas is directed about the burner tubes, and combustion supply air is circulated about and preheated by the exhaust gas conduits and the outer burner tube. The separate combustion of the rich and lean fuel-air mixtures at relatively low temperatures and the subsequent mixing of the flames from the burner tubes results in low NOx emissions and results in high luminosity of the final flame envelope.

Abstract: Several ladles 11-14 for receiving hot metals are preheated by applying a lid 40, 42 to the rim of each ladle and directing an open flame through the lid into the ladle. The hot exhaust gases move back through the lid and through a heat exchanger 35-38 to heat the oncoming combustion air, and the exhaust gases from the ladles being preheated are combined and directed through a lid 41 applied to a ladle at a drying station to dry the ladle.

Abstract: The lid of a ladle heater includes a valve gate rod opening so that the ladle can move toward and away from engagement with the rim of the ladle about a valve gate rod. Cylindrical plug elements are supported between the lid of the ladle heater and the ladle and move apart to straddle the stopper rod, and as the lid moves toward engagement with the rim of the ladle the cylindrical plugs engage the ladle rim as the lid continues its movement, thus resulting in the cylindrical plugs moving into and closing the stopper rod opening.

Abstract: A ladle for receiving molten metal is heated by a direct flame, by applying a lid to the rim of the ladle and directing an air stream through a heat exchanger and through the lid to the ladle, mixing fuel with the air and igniting the mixture and directing the flame into the ladle chamber, and exhausting the gases of combustion from the ladle chamber back through the lid and heat exchanger. A heat shield is mounted adjacent the lid and is sized and shaped to telescopically receive the rim of the ladle, and a ring of air is moved between the heat shield and the rim of the ladle to an air pickup ring. The ring of air blocks the gases escaping from inside the ladle through any openings between the ladle rim and the lid, the heat shield blocks heat radiation from any such openings, and the ring of moving air cools the heat shield.

Abstract: Prior to the receipt of a charge of molten metal, a ladle is heated by a direct flame, by applying a seal to the rim of the ladle and directing air through a heat exchanger and to the ladle, mixing fuel with the air and igniting the mixture and directing the flame in to the ladle chamber, and exhausting the gases of combustion from the ladle chamber back through the heat exchanger. The seal applied to the rim of the ladle comprises a network of refractory fiber modules mounted in a common plane. Each module comprises a rectangular block formed of a web of refractory fibers in an accordion folded arrangement, and the modules are mounted with their folded edges exposed, and with the folds of each module extending at right angles with respect to the folds of the adjacent modules.

Abstract: A system for heating ladles prior to the receipt of a charge of molten metal therein, including heating said ladles by direct thermal transfer from the output gases of a heat source, and including waste heat recuperation and controls for maximizing the efficiency of combustion and for maximizing the rate of heating of said ladles without use of excess fuel. The system of the invention includes a heat exchanger defining an opening in its side to directly receive a ladle supported on its side, the heat exchanger including fuel burners for projecting flame and combustion gases directly into the ladle and a heat exchange chamber for directly receiving the hot combustion gases from the ladle for use in preheating inlet gases to be mixed with fuel for combustion in the burners. Means is provided for transporting the heat exchanger horizontally into and out of engagement with the ladle.