黑心可鍛鑄鐵製造における各種熔解爐の比較

抄録

  To melt the black heart malleable cast iron, cupola, air furnace (a reflecting furnace using heavy oil, pulverized coal and gas as fuel), electric furnace (such as electric arc furnace, induction furnace) are commonly employed, either single or in combination with the other type of furnace in duplex melting system.
  The Kuwana Works of Hitachi, Ltd., to which the authors belong, is provided with the facilities for duplex melting, consisting of a combination of 7-ton cupola and 5-ton Heroult electric furnace, besides 3-ton high temperature blasting cupola and 1-ton high frequency induction furnace.
  In this paper, the authors tersely introduce how these facilities are operated and what is the difference between various melting methods currently in practice. The gists of the paper are as follows :
 (1) Applications of furnaces−from the viewpoint of production scale :
  In case of the daily melting norm exceeds 60 tons, thc duplex melting system using a combination of cupola and electric arc furnace is considered most suitable. When the norm is around 30 tons a day, either of the use of high temperature blasting cupola or the combined system of cupola and high frequency induction furnace is recommended.
 (2) Features of furnaces−from the viewpoint of quality of product :
  High-quality product is hard to manufacture by means of a cupola alone. If the melting equipment is to be used single, the high frequency induction furnace gives the most satisfactory result, and the electric arc type furnace comes next. The high temperature blasting cupola is considered to show a great deal of promise in this respect, if further improvement is performed.
 (3) Comparison of economical advantage :
  In the melting cost, the high temperature blasting cupola comes first, followed by the duplex melting system. The high frequency induction furnace, however, is not so expensive in the operation as generally held.