| 摘要 |
A d.c. arc furnace, of the type in which powdered material is fed through a through- channel in the electrode(s), has a roof which, in addition to an insulating portion around the electrode(s), comprises a plane suspended portion defining the upper limit of an exhaust gas outlet, the lower limit of the outlet being defined by a threshold. The furnace is useful for melt redn. of oxides of e.g. iron, nickel, cobalt and chromium and materials contg. such oxides, by the methods of GB1455221 and 1467542. The design provides ample space at the side of the furnace vessel for the gas outlet thus reducing the gas flow rate and consequent rapid wear of the furnace lining, esp. at the outlet. The plane roof portion reverses the direction of upwards gas flow thus returning dust to the lower part of the furnace. Additionally, the roof is very easy to repair and can have a constant internal height close to the theoretical maximum height. Only a minor portion of the electrode(s) may extend into the furnace to reduce the risk of electrode rupture. |
