Abstract: An improved impeller head is provided for treating molten metals and other liquid systems with a gas. A multiple-vaned impeller head is adapted for mounting on a hollow impeller shaft for rotation within the liquid The edges of the impeller vanes are extended by an axial groove which intercepts the hub and the vanes of the impeller head. Extension of the trailing edge of the vanes creates greater turbulence in the liquid as the impeller is rotated in the liquid and increases the impeller's efficiency. The impeller vanes may also have canted leading surfaces which create an upward axial flow of liquid to discourage formation of a surface vortex. Multiple impellers may also be mounted on a shaft in the vessel and the gas may be introduced remotely.

Abstract: An improved impeller head is provided for treating molten metals and other liquid systems with a gas. A multiple-vaned impeller head is adapted for mounting on a hollow impeller shaft for rotation within the liquid. The edges of the impeller vanes are extended by an axial groove which intercepts the hub and the vanes of the impeller head. Extension of the trailing edge of the vanes creates greater turbulence in the liquid as the impeller is rotated in the liquid and increases the impeller's efficiency. The impeller vanes may also have canted leading surfaces which create an upward axial flow of liquid to discourage formation of a surface vortex. Multiple impellers may also be mounted on a shaft in the vessel and the gas may be introduced remotely.

Abstract: Apparatus for commutating an electrical current to an electrically conductive rod of an alloying element during the feed thereof to a body of molten metal for purposes of changing the alloy composition of the metal. The apparatus includes a power supply capable of providing electrical current in amounts sufficient to melt a free end of the rod of alloying material into the molten metal, and a pair of parallel adjacent shafts of substantial cross-section. A pair of commutation wheels are mounted respectfully on said shafts for rotatably engaging the rod between the wheels and for conducting current to the rod. Means are provided for forcing the wheels against the rod to provide intimate electrical and physical contact between the rod and wheels. A plurality of stationary brushes are disposed to physically engage each of said shafts along the length thereof for supplying current to the shafts from the power supply, and from the shafts to the wheels engaging the rod.

Abstract: A method for introducing grain refiners into molten media, such as molten aluminum, utilizes a chamber having a discharge immersed in the molten media and having a plasma therein extending from the molten media at the chamber discharge to a site above the discharge. Grain refiner is provided to said site and converted into a superheated spray for introduction into the media. An alternate embodiment includes supplying one or more constituents of a grain refiner compound to the plasma for reaction to form the grain refiner. A gas exits the chamber and enhances introduction into the media.

Abstract: A method of producing intermetallic particles such as TiAl.sub.3, NiAl.sub.3 and others utilizes a chamber having a discharge immersed in molten media such as molten metal and having a plasma therein extending from the molten media at the chamber discharge to a site above the discharge. One or more constituents of the desired compound are provided to said site and converted into a superheated spray. The constituents react with each other or with one or more constituents in the aforesaid media to produce the desired compound. A gas exits the chamber and enhances contact and reaction and also transfer to the media.

Abstract: A method for adding alloying material to a molten metal media, such as molten aluminum, is disclosed. The method includes converting the alloying material into a spray of superheated alloy material and directing the spray into the molten metal media at a depth below the media's surface to enhance dissolution and dispersion of the alloying material in the molten media.

Abstract: An improved filter system is disclosed for filtering a liquid media such as molten metal, e.g., molten aluminum and aluminum base alloys, the system comprises a housing containing a first chamber into which molten metal to be filtered passes, a second chamber in the housing, a filter cloth that separates the first chamber from the second chamber, a high specific flow static filter in the second chamber, and means for moving the filter cloth in the housing to expose fresh surfaces of filter cloth to the metal being filtered to inhibit clogging of the filter cloth means by buildup of the filter cake and maintaining a constant high level of filtration efficiency.

Abstract: A system is disclosed for efficiently mixing streams of molten metal to form a molten metal alloy while inhibiting oxidation and introduction of impurities such as hydrogen gas into the molten metal which comprises passing a first molten metal stream at a minimum velocity of at least 18 cm/sec into a mixing zone and feeding a second molten metal stream at a lower velocity into the mixing zone through a concentric feed tube around which the first molten metal stream is flowing. The first molten metal stream is maintained in turbulent flow conditions with a Reynolds number of greater than 2100. In a preferred embodiment, the minimum velocity of the first stream is raised before reaching the mixing zone by introducing a non-oxidizing gas into the stream.

Abstract: A system for purification of molten metal to remove impurities such hydrogen gas and alkali elements therefrom is disclosed which comprises passing the molten metal through an enclosed passageway at a velocity of at least about 0.1 cm/sec and introducing a sparging gas into the passageway whereby the velocity of the molten metal will shear off bubbles of the sparging gas as they are formed resulting in smaller bubbles with larger gas/molten metal interface area to achieve maximum contact between the sparging gas and the molten metal to enhance removal of impurities from the molten metal.

Abstract: A method for adding alloying material to a molten metal media, such as molten aluminum, is disclosed. The method includes converting the alloying material into a spray of superheated alloy material and directing the spray into the molten metal media at a depth below the media's surface to enhance dissolution and dispersion of the alloying material in the molten media.

Abstract: A system for adding alloying material to molten metal media is disclosed. The system includes spark cup means, preferably cylindrically shaped, which is partially immersed in the molten media. The spark cup preferably has a lower open end which is exposed to a submerged surface of the molten media and an upper inlet, at least a portion of which is located above an exterior surface of the molten media. Means for supplying the spark cup means with an arc shielding gas through the inlet is provided as is means for feeding an elongated form of the alloying material through the spark cup inlet into the cup area or chamber of the spark cup. Also provided is means for establishing an electrical arc discharge between the submerged molten metal surface and the free end of the alloying element in the spark cup. The free end of the alloying element is converted into a spray of superheated alloy materials as it passes through the arc discharge.

Abstract: An apparatus and method for ultrasonically detecting inclusions in molten bodies. The apparatus includes a probe comprising an inert refractory shell, a window supported by the shell for carrying ultrasonic waves between a coupling medium and a body of molten metal or molten glass, and a coupling medium contained within the shell for carrying ultrasonic waves between a transducer and the window. A preferred apparatus utilizes a coupling medium comprising liquid gallium and is suitable for detecting inclusions in molten aluminum and aluminum alloys.

Abstract: An apparatus is disclosed for controlling flow rates of a primary fluid including aspirating, mixing, and metering the primary fluid with a secondary fluid. In one aspect, the invention includes means for passing a secondary fluid of diluent gas through a venturi having specified proportions including discharge coefficient; and means for pumping primary fluid through venturi suction to pass through a primary fluid orifice of specified discharge coefficient wherein the venturi discharge coefficients of the venturi and the liquid orifice form a substantially linear proportionality over a wide range of flow rates through the venturi.

Abstract: A method is disclosed for controlling flow rates of a primary fluid including aspirating, mixing, and metering the primary fluid with a secondary fluid. The secondary fluid has a high relative vapor pressure to form a gaseous mixture consisting essentially of vapor at constant volume fraction of primary fluid independent of flow rates. In one aspect, the invention includes passing a secondary fluid of diluent gas through a venturi having specified proportions including discharge coefficient; and pumping primary fluid through venturi suction to pass through a primary fluid orifice of specified discharge coefficient wherein the venturi discharge coefficients of the venturi and the liquid orifice form a substantially linear proportionality over a wide range of flow rates through the venturi.

Abstract: An apparatus and method for ultrasonically detecting inclusions in molten metals. The apparatus includes a probe comprising an inert refractory shell, a window supported by the shell for carrying ultrasonic waves between a coupling medium and a body of molten metal, and a coupling medium contained within the shell for carrying ultrasonic waves between a transducer and the window. A preferred apparatus utilizes a coupling medium comprising liquid gallium and is suitable for detecting inclusions in molten aluminum and aluminum alloys.

Abstract: Molten aluminum or other metals are purified by contacting with a fluorocarbon, such as CCl.sub.2 F.sub.2, in order to decrease the amount of impurity metal elements along with gas and inclusions therein preferably in the presence of an agitator to enhance efficiency. An oxidizer, such as oxygen, is employed to prevent the carbon in the fluorocarbon from forming carbide inclusions. Oxidizing the carbon to carbon monoxide is preferred in treating aluminum since the monoxide effectively removes the carbon from the system without oxidizing aluminum. Preferably, a fluorine acceptor is employed to temporarily combine with the fluorine in the fluorocarbon and prevent it from reacting with carbon such that the fluoride is still available to treat the molten metal. The gases employed to treat the molten metal can be passed over a bed of carbon immediately prior to introduction into the melt.