Abstract: A hoisting mechanism for handling the cover of an electric arc furnace comprises a pivotable gantry base and gantry arms connected thereto which extend over the furnace cover. Traverse bars overlay the gantry arms and are connected to the furnace cover by hoisting rods which pass through the gantry arms. Lifting mechanisms preferably in the form of hydraulic piston-cylinder arrangements are secured, on one end, to the gantry arms and, on the other end, to the lower side of the traverse bars. The mechanism is electrically insulated to eliminate deterioration of the equipment and the existence of electrical circuits and, in addition, the hoisting rods and the piston cylinder mechanisms are water-cooled.

Abstract: Electric furnace arrangement including a furnace vessel with liftable and lowerable lid penetrated by at least one electrode. The electrode is fastened to a liftable and lowerable supporting construction by first clamping devices. For lifting the lid, a further clamping device for the electrode is provided on the lid, at least one coupling element is provided on the supporting construction and at least one counter-coupling element is arranged on the lid, which can be brought into and out of engagement with the coupling element. A connecting element can be provided between coupling element and supporting construction.

Abstract: An electric arc furnace for melting metal, especially steel, includes a container having an upper open ended substantially cylindrical wall portion and a lower cylindrical wall portion extending downwardly therefrom and being closed at the bottom and receiving during operation of the furnace a bath of molten material having an upper level at a predetermined maximum elevation above the bottom of the container. The container includes an outer metal shell and refractory material covering at least the lower wall portion of the shell and the closed bottom. In order to increase the charging volume of the container without essentially changing the height thereof, the upper wall portion has, at a distance of at least 300 mm above the level the bath of molten metal, an inner diameter which is greater than the outer diameter of the metal shell of the lower wall portion.

Abstract: A form for constructing a refractory roof for an electric arc furnace having a provision for selectively changing the electrode opening pattern and also forming a roof of different diameters.

Abstract: In order to move a furnace body (1) and a furnace lid (2) relative to one another by approximately one furnace body width, the separating surfaces of the furnace body (1) and furnace lid (2) are inclined relative to the horizontal.The direction of movement when the furnace body (1) is moved then runs in the direction of the angle opening and, when the furnace lid (2) is moved, the movement is in the opposite direction.In order to reduce the frictional forces between the separating surfaces (4, 5) of the furnace body (1) and furnace lid (2) and to ensure that the relative movement of the furnace body (1) and the furnace lid (2) occurs under defined conditions, the furnace lid (2) is supported on at least two support points on the furnace body (1) on which roller tracks (6) are arranged together with support rollers (7) which roll on the tracks for a certain travel.

Abstract: A method of producing aluminum is carried out in an electric arc furnace having primary and secondary zones separated by a divider constructed to permit the flow of molten but not gaseous products between zones. The method includes providing a charge of carbon into the primary zone containing a mixture of aluminum and aluminum carbide and providing a charge of alumina to the secondary zone, simultaneously heating the zones to react said carbon with the aluminum to form aluminum carbide in said mixture, flowing the mixture into the secondary zone, reacting the aluminum carbide in the mixture with alumina to form additional aluminum and an aluminum oxycarbide slag, flowing the slag to the primary zone for reaction with the aluminum carbide to form aluminum in the mixture, and tapping aluminum from the secondary zone.

Abstract: A method and a hood for mixing a hot furnace gas with a second gas before the furnace gas is discharged from a furnace by directing the hot furnace gases out via a hood which forms an uninterrupted space for gas with the furnace is disclosed in which the second gas is fed along the side walls of the hood substantially countercurrently in relation to the hot gases emerging from the furnace in order to mix the gases with each other into a toroidal vortex, and that the gases are removed from this vortex tangentially.

Abstract: The present invention relates to a reduction furnace with a split furnace body, particularly suited for production of ferro alloys, pig iron or calcium carbide. Furnaces of such types are provided with a furnace pot equipped with an internal refractory lining anchored to the furnace wall by means of anchoring elements. According to the present invention the refractory lining of at least the upper section of the split furnace body comprises a plurality of individual, pre-fabricated elements which are removably arranged at least on the upper section. Each unit comprises preferably a rear plate of steel, pig iron or similar material and one or more anchoring ribs or bolts extending horizontally out from and rigidly secured to the rear plate. The anchoring ribs provide a hold for the refractory lining on the rear plate. The separate units are suspended at least from the upper segment by means of simple support means.

Abstract: An electric furnace includes a lifting structure actuating a furnace cover and comprising a stationary supporting post. A lifting means is axially displaceably guided on the stationary supporting post by an upper and a lower bearing. The lifting column is liftable and lowerable by the lifting means and engageable with, and disengageable from, the furnace cover. In order to provide a lifting structure that enables either a lower construction height or substantially slighter forces in the bearings of the lifting column, the hollowly designed lifting column peripherally surrounds the stationary supporting post. The lifting means is articulately connected with a head plate closing the lifting column on its upper end and with a stationary part of the plant.

Abstract: A water-cooled lid made of steel tubing and removably mountable on the top of the body of an electric furnace comprises a small central top portion having electrode inserting bores, a circular ring along its outer periphery and a plurality of sectorial segments arranged radially between the top portion and the circular ring. Each of the sectorial segments has a zigzag cooling water channel formed by steel tubing, extending along circumferences concentric with the lid and having a cooling water inlet and cooling water outlet. The zigzag channel is formed by bending a single steel tube into zigzag portions folded together in intimate contact with one another. Alternatively the channel is formed by a plurality of steel tubes arranged side by side in intimate contact with one another along circumferences concentric with the lid and steel frames having communicating chambers in communication with the open ends of adjoining tubes.

Abstract: A melt reduction furnace has a flat gas-tight roof through which the oxide feeding electrode projects an extent less than usual inside the furnace to reduce its breakage risk, and a side wall gas exhaust opening above an upstanding threshold providing low-velocity gas exhaust while the threshold holds back gas flow with possible dust below the opening.

Abstract: Electric arc furnace, of the type having metallic walls (2) and an at least partly metallic roof (1), and provided with radiation detection apparatuses (8) for their controlled operation. Differential water circulation transducers (8) are positioned in the intrados of the metallic part (7) of the roof (1); they project with respect to the inner surface of the roof and their end faces (16) facing the interior of the furnace are concave.

Abstract: The invention relates to an arc furnace roof. The roof is comprised of a metal cover which is bolt-connected to the furnace shell. Secured to the lower side of the cover is a plurality of shackle hooks, each of said shackle hooks having an anchor bolt hooked therein. The metal cover has a first layer of insulating concrete applied to its lower side and a second layer of refractory concrete applied to the hard first layer of insulating concrete, the two layers of insulating and refractory concrete, respectively, embedding the shackle hooks and anchor bolts.