Abstract: The invention relates to a smelting furnace, particularly a D.C. arc furnace, suited for the treatment of finely-divided material, which comprises at least three electrodes suspended through the roof in order to create the electric arc. The process material is fed in through at least one feed gate (30) arranged inside the circle orbit formed by the electrodes (4, 16, 26) suspended through the furnace roof, which feed gate (30) is provided with auxiliary members in order to create an even supply of the material into the furnace. In order to discharge the gases created in the process, there is provided at least one outlet (20) outside the circle orbit formed by the electrodes (4, 16, 26).The invention also relates to a method for feeding finely divided material into the smelting furnace. According to this method, the material is fed through the feed gate (30) in suspension, either vertically or tangentially.

Abstract: The present invention relates to a method and apparatus for preparing a feed mixture, made of several batch components, at one stage in order to feed it into a smelting furnace. The preparation of the batch may include the preheating and drying of the material, the removal of crystal waters and evaporable substances as well as the conduction of the batch into the smelting furnace. According to the invention, a hot inert gas is conducted through a downwards settling batch so that the gas is mixed into the batch as well as possible, but even partial fluidization is prevented. The apparatus of the invention comprises a pretreatment silo (6) which is uniform at the upper part but is divided into several sub-silos (7) at the lower part. At the lower part of the sub-silos there are connected ducts (8) wherealong the batch flows into the smelting furnace (9) located below the pretreatment silo (6).

Abstract: The present invention relates to a method and apparatus for preparing a feed mixture, made of several batch components, at one stage in order to feed it into a smelting furnace. The preparation of the batch may include the preheating and drying of the material, the removal of crystal waters and evaporable substances as well as the conduction of the batch into the smelting furnace. According to the invention, a hot inert gas is conducted through a downwards settling batch so that the gas is mixed into the batch as well as possible, but even partial fluidization is prevented. The apparatus of the invention comprises a pretreatment silo (6) which is uniform at the upper part is divided into several sub-silos (7) at the lower part. At the lower part of the sub-silos there are connected ducts (8) wherealong the batch flows into the smelting furnace (9) located below the pretreatment silo (6).

Abstract: A method and device for clamping the electrode contact shoes (2) around the electrode (1) of an electric furnace, comprising one pressure element (3) which is advantageously hydraulically operated and uniform and which surrounds the electrode contact shoes and clamps them against the electrode (1) under the action of pressure on the pressure element.

Abstract: The invention relates to a device for poking a charge fed onto the surface of a melt in an electric arc furnace having a hood and an external cooled casing (2) articulated at one of its ends to the lower section (21) of a horizontal circumferention bend in the wall of the furnace (23) hood (24) which faces the melt, drive cylinders (5) for tilting the casing in different directions about its joint, a spindle ( 1) installed tightly in the cooled casing (2) and being axially reciprocating and rotatable, and drive cylinders (17) for making the spindle (1) to project from said one end of the casing (2) to poke the charge fed onto the melt surface and break any crust on the melt surface or inside the solid charge, when the cooled casing (2) and the spindle (1) inside it are tilted about the joint and rotated.

Abstract: A method and device for facilitating the maintenance and replacing of the contact shoes of the electrodes in an electric-arc furnace, the supporting mantle of the contact shoes consisting of two sections, the lower one of which can be lifted, together with the contact shoes, telescopically over the upper section, whereby the contact shoes rise above the furnace hood.

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.