Abstract: The device for charging metalliferous materials 7 into a furnace 3 compri a charging tube 1, inside which are arranged supports 8 distributed over an entire non-straight section of this, for example similarly to the stairs of a flight of stairs descending towards the furnace. Passages are provided between the supports 8, and means 10 for the vibration of the supports are provided.The materials progressively descend on the supports 8 towards the furnace and are simultaneously preheated by the hot gases introduced into the tube, circulating through the materials and via the passages 9 and extracted via the outlet orifice 5.

Abstract: A wall electrode includes a metal bar adapted to extend through the wall of the furnace, a water-cooled sleeve composed of a material which is a good conductor of heat and electricity, an end member composed of a material which is a good conductor of heat and electricity, and an annular member such as a ring composed of a metal which is heavy and has a low melting point surrounding the bar so that the heavy metal in the liquid state spreads in the space between the bar and the sleeve when the annular member is made to melt during use of the electrode.

Abstract: The metallurgical vessel, such as a direct-current arc furnace, comprises a metal housing (1) lined on its inside with refractory material (2), at least one electrode (3) passing through the bottom of the vessel and connected to a terminal of an electrical power supply, the electrode being fastened to the metal housing by a mechanical fastening arrangement and insulated electrically from the housing. A leaktight wall (20) surrounding the fastening zone of the electrode prevents a liquid flowing over the inner surface of the housing from coming into contact with the electrode fastening arrangement, and orifices (26) are provided for discharging the liquid collected out of the housing. The invention is particularly applicable to direct-current arc furnaces and prevents the molten lead originating from the scrap metal of the charge and infiltrating through the refractory from damaging the electrical insulation of the fastening of the electrode.

Abstract: The electric connection device comprises an electrode (5), a sleeve (19) mounted around a projecting end part (8) of the electrode (5), and an arrangement for cooling the sleeve (19) with a cooling fluid comprising at least one system (20, 20') of nozzles (21) spraying cooling fluid onto the outer surface of the sleeve (19).

Abstract: According to this process and this device:a signal representing the derivative of the intensity of the current in the arc is sensed,the sensed signal is amplified,the amplified signal is directed simultaneously into two band pass filters (6, 7) respectively having a high frequency broad band (6) and having a narrow band centered on a low fundamental frequency (7),the signals emanating from the filters (6, 7) are transmitted to effective value extractors (8, 9),by means of a divider module (11) an energy signal is formulated, which is proportional to the ratio of the effective value of the signal emanating from the broad band filter (6) and the effective value of the signal emanating from the narrow band filter (7),and the proportional energy signal obtained is displayed on a scale (12), where it is expressed as a percentage, this percentage being indicative of the behaviour of the arc, signifying the formulation phase.

Abstract: A wall electrode for a D.C. powered electric arc furnace for the processing of metals in a liquid state, especially steel. The electrode is constituted mainly (a) by a metallic bar (4) one of whose ends comes into contact with the metallic bath (6), while a portion (7) of its other end extends to the exterior of the furnace; (b) by a sleeve (8) of thermally and electrically conductive material, energy-cooled by a flow of cooling fluid, surrounding the portion (7) of the other end of the bar at a distance therefrom; (c) by a nipple (9) of good electrically conductive material extending the aforementioned portion (7) of the other end of the bar; and (d) by a connection of the nipple and the sleeve to the same bar of an electrical supply.

Abstract: The device according to the invention consists mainly of:an inner part passing through the wall of the furnace and comprising a metal core 7 extended by a cooled plug 10, the free end of the core opposite to the plug being in contact with the molten mass of metal present in the furnace,a sleeve 11 made of thermally conductive material, which is cooled as a result of the circulation of a cooling fluid and which surrounds the core 7,and means 29 of connecting the metal core 7 to an electrical supply.The device according to the invention is characterized in that it also presents a separation space 12, formed between the sleeve 11 and the metal core 7, and an elastic fastening system 33, 34, 35 tending to return the said core 7 to its initial position given by assemblage.The device according to the invention is advantageously used as a hearth electrode in direct-current arc furnaces, specially for the iron and steel industry.

Abstract: Electrical connecting device to be placed in contact with a molten metallic mass, comprising an elongated metallic body (5) introduced through the wall of a container, to be placed in contact with the metallic bath by one of its ends, the other end constituting a terminal portion (8) projecting to the outside of the container wall, a sleeve (9) made of good thermal and electrical conductive material surrounding and contacting the terminal portion, the sleeve being connected to a charged electrical source and cooled by circulation of a cooling fluid. The device is used when contact between an electrode and a molten mass is required, and eliminates the risk of tapping from excessive melting of the electrode.

Abstract: A direct-current arc furnace has a vessel with a floor and a cover, at least two vault electrodes projecting down into the vessel through the cover, and a hearth electrode exposed in the vessel generally in the floor below the vault electrodes. A scrap-metal charge is melted in this furnace by first energizing the vault electrodes with direct-current voltage of opposite polarity while displacing them downward through the charge from an upper position spaced relatively far from the hearth electrode to a lower position spaced relatively close to the hearth electrode and thereby passing an electric current through the charge to melt the charge and form a puddle of molten metal on the floor of the vessel at the hearth electrode.

Abstract: An electric arc furnace comprising at least one pair of electrodes extending through the roof of the furnace for the creation of electric arcs between each of the electrodes and the charge to be melted, and a source for applying direct current to each of said pairs of electrodes, respectively of different polarities. Preferably the furnace contains also an electric probe extending through the bottom of the furnace to determine the potential of the molten charge and means for adjusting the vertical position of each electrode for maintaining the potential difference between each electrode and the molten charge at a predetermined value.