METHOD FOR CONTROLLING OPERATION OF VACUUM ELECTRIC ARC FURNACE Russian patent published in 2002 - IPC

FIELD: special electronics, namely heating metals by means of arc discharge, possibly controlling exploitation of furnace at vacuum electric arc melting of metals and alloys with high reaction capability such as titanium. SUBSTANCE: method comprises steps of additionally measuring changing rate of ratio of intensities of spectral lines of metal of crystallizer and metal of electrode during predetermined time period Δt; lowering electric current of electric arc at preset rate of achieving its threshold value; increasing intensity of magnetic field of solenoid; at lowering ratio of spectral line intensities at least by two times during subsequent time interval Δt₁, increasing electric current of arc and lowering intensity of magnetic field of solenoid until its operational value. If such above mentioned lowering of ratio of spectral line intensities does not occur cutting off electric current of arc for time period Δt₂. Sum of three above mentioned time periods Δt, Δt₁, Δt₂ and time interval τ of transition processes is to be less by order than time interval of burning out of crystallizer wall. EFFECT: enhanced validity of signal indicating explosion hazard mode, improved stability of melting process, high quality of melt metal due to elimination of interruptions caused by deenergizing of furnace by error signals. 2 dwg