Bottom electrodes for arc furnaces

In an electric DC arc furnace having a vessel with a jacket which includes a bottom, there being electrodes arranged in the bottom, the interior of the vessel being lined with fireproof and refractory material, there being in addition provided facilities for cooling the vessel and connections to the cooling facilities, the improvement comprising:

• said electrode being comprised of (i) a wear and consumable element, penetrating the refractory lining from the bottom of the vessel jacket, for engagement with molten metal in the interior of the vessel, said consumable electrode element being provided with an axial blind bore facing away from the interior of the vessel, said electrode further including (ii) a cooling sleeve inserted in said blind bore;
• (iii) a tubular element, said cooling sleeve, in turn, receiving said tubular element for the conduction of cooling medium;
• and
• an electrically conductive and heat resisting layer provided in the fireproof lining, said layer extendig parallel to the jacket of said furnace, said layer, at least partially, embracing and enveloping said consumable element of the electrode and exceeding for some portion of the length extension of the electrode as traversing the bottom and lining.