(19)
(11) EP 0 453 188 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
28.04.1993 Bulletin 1993/17

(43) Date of publication A2:
23.10.1991 Bulletin 1991/43

(21) Application number: 91303238.9

(22) Date of filing: 11.04.1991
(51) International Patent Classification (IPC)5: B22D 11/10, B22D 41/015
(84) Designated Contracting States:
BE DE ES FR GB IT LU NL SE

(30) Priority: 19.04.1990 GB 9008833

(71) Applicant: The BOC Group plc
Windlesham Surrey GU20 6HJ (GB)

(72) Inventors:
  • Moore, Colin
    Chellow Dene, Bradford, BD9 6AX (GB)
  • Heanley, Charles Peter
    Faringdon, Oxon, SN7 7LW (GB)
  • Cowx, Peter Malcolm
    Ashbury, Wiltshire, SN6 8LX (GB)

(74) Representative: Wickham, Michael et al
c/o Patent and Trademark Department The BOC Group plc Chertsey Road
Windlesham Surrey GU20 6HJ
Windlesham Surrey GU20 6HJ (GB)


(56) References cited: : 
   
       


    (54) Plasma tundish heating


    (57) A method of heating molten material in a tundish employs a plasma torch. The plasma comprises a mixture of argon and one or more of nitrogen, hydrogen, neon and helium. A mixture of argon and helium including from 10 to 20% by volume of helium is useful for heating steel. For an arc of given length, a higher voltage is obtainable than when pure argon is used as the plasma gas. The torch is preferably engaged by a horizontal support arm which is pivotally mounted on an extensible support so as to facilitate location of the torch in a limited space above the tundish.






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