Abstract: Provided are methods and apparatuses for the sensing of a property of a molten metal that lies beneath layers of interfering matter. A stream of gas is propelled into the layers of interfering matter at a velocity that is sufficient for the gas to penetrate through the layers of interfering matter and into the molten metal, thereby providing an opening through the layers of interfering matter. At the same time, energy emanating from the molten metal is detected and measured through the opening, so as to obtain an energy measurement. Then, the energy measurement is processed to determine a value for the desired property of the molten metal.

Abstract: The present invention discloses an electric arc furnace wherein the natural gas flow is artificially altered to obtain beneficial effects. By injecting gases, preferably but not necessarily containing oxygen, into the electric arc furnace in the vicinity of the electrode port, the injected gases move vertically downward near the furnace center toward the bath. This process of injecting gases downward around the electrode enables the natural circulation in the furnace to be reversed. When gases reach the bath level, they disperse outward penetrating the scrap and depositing heat energy thereon. By preheating the scrap in this manner production is increased and emissions released into the off-gas system can be reduced.

Abstract: This invention relates to a fume hood in which side and top walls define a space enclosed on all sides but the underside, the hood having baffle plates within the space, the plates sloping upwardly and outwardly adjacent the side walls, the plates having their upper edges spaced from the walls of the hood. Suction opening is located in the top wall centrally above the baffle plates.