METHOD FOR CONTROL AND COMPLEX DIAGNOSTICS OF STATE OF PINCH ROLLS AND THEIR DRIVE UNITS IN SECONDARY COOLING ZONE OF PLANT FOR CONTINUOUS CASTING OF METALS AND ALLOYS Russian patent published in 2004 - IPC

FIELD: metallurgy, namely plants for continuous casting of metals and alloys.

SUBSTANCE: method comprises steps of measuring intensity of electric current of load of electric motors of pinch rolls before and during casting process; measuring total electric current for all electric motors of pinch rolls and casting rate at casting process; carrying out diagnostics of auto-oscillation mode in electromechanical system " electric motor -pinch roll - ingot"; controlling slipping of pinch roll on ingot, periodical absence of contact between pinch roll and ingot, bending value of pinch roll, wear degree of drive units of pinch rolls; in order to realize such diagnostics procedures creating several data files, namely: data file of values of electric current of load of electric motors of pinch rolls, casting rate and total electric current of load of all electric motors of pinch roll for time period equal at least to two revolution number of pinch roll; data file of idle mode electric current which includes values of idle electric currents for one time period between repair operations; file including data for detecting matching of changes of electric current of load of motors of pinch rolls and bending values of pinch rolls; in order to realize diagnostics of above mentioned errors, carrying out spectral analysis of file data of electric current of load and casting rate, autocorrelation analysis of said file for determining time period of changing values of electric currents of loads of electric motors of pinch rolls and of total electric current and for detecting changing rate of electric current values of loads of electric motors of pinch rolls. When time period of change of electric current of load and changing rate of electric current of load correspond to predetermined designed values, it is judged that self-oscillation mode exists in electromechanical system " electric motor - pinch roll - ingot" or there is slipping of pinch roll on ingot or periodically there is no contact between pinch roll and ingot. Bending value (mm) of pinch roll is evaluated according to first harmonic component of spectrum of changes of electric current values of load of electric motors of pinch rolls. Wear degree of drive units of pinch rolls is evaluated on base of changes of electric current of load of electric motors of pinch rolls measured for good working equipment before beginning of casting process.

EFFECT: shortened time period for repair works of steel continuous casting plant, increased factor of using plant, lowered cost for changing equipment of plant.

5 dwg, 1 ex