摘要 |
<p>1,241,708. Electric arc furnaces. BADISCHE ANILIN- & SODA-FABRIK A.G. 2 Dec., 1968 [2 Dec., 1967], No. 57027/68. Heading F4B. [Also in Divisions C6-C7 and H3-H5] Argon gas is blown into the steel melt 4 in the base 3 of an electric arc furnace 1, through refractory brick nozzles 7 located below the electrodes 5. The gas causes circulation and degassing of the melt and stabilization of the electric arcs 6. The gas may be used as a carrier for powdered calcium fluoride, sand, limestone, or sodium or barium compounds which cause lengthening of the electric arcs to increase the energy transferred to the melt in the initial process stages, and as a carrier for boric acid to shorten the arc length during the later refining stages. It may also act as a carrier for nucleating or alloying components. Further argon gas is supplied through ring tubes 12 surrounding the door openings 9 to prevent ingress of air.</p> |