Patent ID: 8837552
Filing Date: 2014-09-16
Classification: H05B

Abstract:
1. A sealing device arranged around a rod electrode extending vertically through an aperture made in the ceiling of an arc furnace and being vertically movable inside the furnace to prevent the access of gases from the furnace through the aperture to the atmosphere, and on the other hand to prevent air from flowing from the atmosphere into the furnace, the sealing device comprising: a gas distribution chamber provided with an inlet channel for feeding gas in the gas distribution chamber, and a nozzle through which a gas jet is arranged to be discharged from the gas distribution chamber towards the electrode, wherein the nozzle is a slit nozzle encasing the electrode and discharging the gas jet in a direction that is at an angle with respect to the horizontal plane and has a slightly upwards inclined orientation, and that is, with respect to the furnace interior, pointed outwardly, so that the sealing is carried out owing to the effect of the created stagnation pressure; and that the sealing device is assembled on an electrically insulating slide bearing comprising: a metallic first base ring that is arranged on top of the edge of the aperture, a second base ring made of an electrically insulating material, arranged on top of the first base ring, and a metallic third base ring that is arranged on top of the second base ring, so that on top of said third base ring, the sealing device is arranged to rest only by gravity, without other fastening, in order to allow a limited lateral movement of the sealing device for adapting to the lateral movement of the electrode.