Danieli & C. Officine Meccaniche S.p.a.

Peter Tishchenko

Alfredo Poloni

Milorad Pavlicevic

Angelico Della Negra

Gianni Gensini

Alessandro Martinis

A cooled roof for electric arc furnaces (,) or ladle furnaces (,). The roof being used as a covering element and including a cooling system comprising tubes fed with cooling fluid. The roof including at least a central aperture (,) for the positioning and movement of the electrodes (,) and at least a peripheral aperture (,) for the aspiration and discharge of fumes. The aperture (,) being connected to intake systems. The roof including two single-block cooling structures, inner (,) and outer (,), consisting of respective bent tubes (,) developing according to adjacent and superimposed rings or spirals. The inner (,) and outer (,) cooling structures being associated with one another at least in correspondence with the respective bases facing towards the inside of the furnace (,). Between the inner cooling structure (,) and the outer cooling structure (,) there being defined an annular interspace (,) in which the fumes circulate in an annular direction and slow down. The annular interspace (,) communicating with the peripheral aperture. The inner cooling structure (,) including fume-transit interstices connecting the inside of the furnace (,) with the annular interspace (,).

Cooled roof for electric arc furnaces and ladle furnaces

Cooling device with panels for electric arc furnaces, employed in an electric furnace in cooperation with the vertical sidewall located above the lower shell (,) of the furnace and/or with the roof (,), the furnace comprising a lower shell (,) to contain the bath of liquid metal (,) and an overhead upper shell defined by a plurality of panels (,) consisting of cooling tubes (,), the upper shell being covered by the roof (,), the lower shell (,) including a containing element (,) made of metal on the outer part, the internal refractory including an upper edge (,) located approximately at the upper line of the layer of slag (,) present above the bath of molten metal (,), each panel (,) including an outer layer (,), an intermediate layer (,) and at least an inner layer (,) of cooling tubes (,), the layers developing vertically along the vertical sidewall of the furnace above the refractory edge of the lower shell (,), the cooling tubes (,), the layers developing vertically along the vertical sidewall of the furnace above the refractory edge of the lower shell (,), the cooling tubes (,) of each layer (,) being progressively and increasingly distanced from each other from the outside of the furnace towards the inside so as to define fissures and spaces of a progressively increasing size whereon the slag attaches itself.

Cooling device with panels for electric arc furnace

System to plug the roof of an electric arc furnace having a main chamber or melting volume arranged below the roof and at least one electrode introduced into the main chamber, the system comprising an upper element or auxiliary roof element arranged on the top of the roof and shaped so as to define an inner chamber and at least a central aperture through which the electrode can be moved, the auxiliary roof element consisting of a plurality of pipes inside which a cooling fluid circulates under pressure.

System to plug the delta area of the roof of an electric arc furnace

Aspiration system to reduce the losses of fine materials and powders from an electric arc furnace having a lower hearth suitable to contain the bath of metal material being melted, a substantially cylindrical chamber arranged above the hearth, at least one electrode arranged in a central zone of the chamber and a roof arranged to cover the chamber and provided with at least one aperture through which the fumes produced by the bath can exit, the system comprising a first aspiration sub-system arranged inside the chamber and at least another discharge sub-system arranged in correspondence with the roof, the first aspiration sub-system comprising a coil of cooling pipes arranged helical so as to define, in a vertical direction, empty zones between the spirals of pipes, the coil of cooling pipes being distanced from the cylindrical wall of the chamber to define a peripheral interspace through which the fumes can ascend towards the roof according to at least an ascensional, rotatory vortex.

Aspiration system to reduce the losses of fine materials and powders from an electric arc furnace

Tapping method for molten metal from containers (13) including at the lower part a tapping channel (14) associated at the end part with a discharge hole (15) substantially vertical or sub-vertical, the discharge hole (15) being associated at the lower part with a sliding interception device (19), wherein the tapping channel (14) comprises, associated with the walls, an electromagnetic device (17) with spirals (18) and a system for cooling the walls, wherein, during the end-of-tapping step of the liquid metal the sliding interception device (19) is activated by closing the discharge hole (15) and allowing the metal in the tapping channel (14) to solidify so as to form at least a layer which lines both the tapping channel (14) and the discharge hole (15) filling it completely, and that during the start-of-tapping step the sliding interception device (19) is activated by leaving the discharge hole (15) free and the metal which is blocking the discharge hole (15) is melted by means of the electromagnetic device (17) by varying the characteristics of the current flow. Tapping device which achieves the method as described above and comprising means (38) to feed the electromagnetic device (17) with electric current as a function of the steps of melting and tapping, the sliding interception device (19) comprising a first part (23a) with a high resistance to heat shock, corrosion and erosion and a second part (23b), positioned adjacent to the first part (23a), with high heat conductivity.

Tapping method for electric arc furnaces, ladle furnaces or tundishes

Device to cool the roof (10) in electric arc furnaces, of the type comprising a plurality of contiguous panels (27) disposed to cover at least a substantial part of the inner circumferential periphery of the roof (10), each of the panels (27) consisting of at least one pipe (11) wherein cooling fluids circulate, the roof (10) having at least one central aperture (35) to insert, position and move the electrodes (28) and at least one peripheral aperture, or fourth hole (16) to vent the fumes from inside the furnace, each cooled panel (27) covering its own defined arc of the inner circumferential ring of the roof (10) and comprising a spiral-shaped cooling pipe (11), the coils (15) of the spiral lying on respective vertical planes disposed substantially radially with respect to the center of the roof (10), the coils (15) defining a first outer layer (17) and a second inner layer (18) of pipes (11), the first outer layer (17) and second inner layer (18) being separated by a hollow space (19) lying on a plane suitable to the conformation of the roof (10) of the furnace and which serves as an intake ring (19) to circulate the fumes and direct them from inside the furnace towards the discharge aperture (16).

Cooling device for the roof in electric arc furnaces

Fume intake and cooling device for intake conduits (11,111,211) in electric arc furnaces (26a,26b), comprising a containing structure (28) associated at one end (12) with an aperture on the roof of the furnace and connected at the second end (13) with an intake and filter system (27), the containing structure (28) having, in cooperation with its inner sidewalls, cooling means, the cooling means comprising a pipe (14), which is spiral shaped and has turns (16) lying on a plane substantially at right angles to the longitudinal axis of the conduits (11,111,211), the turns (16) being distanced with respect to each other in such a way as to form interstices (20) between adjacent turns (16), the interstices (20) through which the fumes pass serving to anchor the slag.

Fume intake and cooling device for electric arc furnaces

An exhaust device to suck in the fumes in an electric arc furnace (11) fed either by direct or alternating current. The furnace (11) comprises a crown (20) with at least one aperture (19) to introduce and position the electrodes (12) associated with a cupola, in a vertically raised position, which surrounds the electrodes (12) partially in a vertical direction. The cupola is smaller in diameter than the crown (20), there being included a fourth hole connected to the discharge pipe for the fumes (14). The cupola functions as a decantation chamber (13) substantially cylindrical in shape. The cupola functioning as a decantation chamber (13) including at its upper part a conduit (15) to discharge the fumes projecting tangentially and connecting the cupola functioning as a decantation chamber (13) to the discharge pipe (14), placed at the side of the cupola (13). A method to suck in fumes for an electric arc furnace fed either by alternating or direct current is also provided, wherein the furnace includes a fourth hole connected to a discharge pipe (14) for the fumes associated with a plant.

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Donezk, Ukraine

Peter Tishchenko