公开(公告)号：US3827877A

公开(公告)日：1974-08-06

申请号：US29443672

申请日：1972-10-02

Applicant: HUETTENWERK OBERHAUSEN AG

Inventor： PANTKE H ,  POHL U

IPC: C21C5/52 ,  H05B6/22 ,  H05B5/12

CPC classification number: H05B6/22 ,  C21C5/5241 ,  Y02P10/253

Abstract: THE CRUCIBLE OF AN INDUCTION FURNACE IS SURROUNDED BY AN UPRIGHT COIL THAT IS ENERGIZED BY ALTERNATING-CURRENT ELECTRIC POWER. THE POWER INPUT TO THE COIL IS OF SUCH A LEVEL THAT A RAISED, SLAG-FREE CROWN IS FORMED ON THE TOP OF THE MELT AND AT LEAST 55% OF THE SLAG PRODUCED IS RETAINED TO FORM AN ANNULUS AROUND THIS CROWN. THE CENTRALLY ASCENDING AND PERIPHERALLY DESCENDING CURRENTS IN THE FURROUS MELT CAUSE THE CROWN TO FORM AND ALSO INDUCE THE ANNULUS TO INTROVERT (CIRCULATE INWARDLY AND DOWNWARDLY) SO THAT LIGHT SPONGE IRON ADDED TO THE MELT IS DRAWN DOWNWARDLY INTO THE SLAG-STEEL INTERFACE AND QUICKLY HEATED AND BROUGHT INTO INTIMATE CONTACT WITH BOTH FLOATING SLAG AND THE FERROUS MELT. THE POWER IS FED TO THE COIL IN A MAGNITUDE DETERMINED BY THE RELATIONSHIP P>K(F**(1/2)) WHEREIN P IS THE POWER INPUT IN KILOWATTS PER TON OF THE MEL,T, K IS THE ANNULUS-FORMING CONSTANT AND IS GREATER THAN 45 AND PREFERABLY MORE THAN 49.5, AND F IS THE FREQUENCY IN HZ. OF THE ALTERNATING CURRENT.