Method and apparatus for regulating the molten metal level in a mold of a continuous casting installation

Claim 1

A method of regulating the level of molten metal in a continuous casting mold of a continuous casting installation, wherein deviations in the level of the molten metal in the continuous casting mold, as determined by measuring such level, from a reference value are eliminated by regulating either the inflow of metal to the mold, the withdrawal speed of the strand from the mold, or both the inflow of metal to the mold and the withdrawal speed of the strand from the mold, the improvement comprising the steps of generating a signal indicative of deviations from said reference value, generating adjustment magnitudes at a metal inflow regulation circuit in response to said signal, delivering such adjustment magnitudes to a strand withdrawal regulation circuit, altering a preset reference value of the strand withdrawal regulation in dependency of such adjustment magnitudes according to a preset function, and presetting said function such that the reference value of the strand withdrawal regulation is only then influenced when the change in the adjustment magnitude in the metal inflow regulation circuit per unit of time exceeds a preset value.

Claim 2

A method of regulating the level of molten metal in a continuous casting mold of a continuous casting installation, wherein deviations in the level of the molten metal in the continuous casting mold, as determined by measuring such level, from a reference value are eliminated by regulating either the inflow of metal to the mold, the withdrawal speed of the strand from the mold, or both the inflow of metal to the mold and the withdrawal speed of the strand from the mold, the improvement comprising the steps of generating a signal indicative of deviations from said reference value, generating adjustment magnitudes at a metal inflow regulation circuit in response to said signal, delivering such adjustment magnitudes to a strand withdrawal regulation circuit, altering a preset reference value of the strand withdrawal regulation in dependency of such adjustment magnitudes according to a preset function, and presetting said function such that the reference value of the strand withdrawal regulation is only then influenced when the change in the adjustment magnitude in the metal inflow regulation circuit per unit of time exceeds a preset value.

Claim 5

An apparatus for controlling the molten metal level in a mold of a continuous casting installation, comprising a first regulation circuit for the regulation of the infeed of molten metal to the mold, said first regulation circuit comprising reference value-adjustment means for presetting a reference value of the level of the molten metal in the mold, a comparator in circuit with said reference value-adjustment means, a first transmission element in circuit with said comparator, an adjustment element for adjusting the flow of metal into the mold in circuit with said transmission element, and output means connecting said transmission element with said adjustment element for transmitting adjustment signals thereto, a second regulation circuit for regulating the withdrawal speed of the cast strand from the continuous casting mold, said second regulation circuit incorporating a comparator, a second transmission element in circuit with said comparator, and an adjustment element for adjusting the withdrawal speed of the strand from the mold, measuring means for determining the degree of filling of the mold, both regulation circuits being connected in parallel with said measuring means, a function generator operatively connected with said measuring means and said second regulation circuit, a reference value-adjustment means for presetting a reference value of the withdrawal speed of the strand operatively connected with said function generator, and means for altering the reference value of the withdrawal speed in dependence upon adjustment signals generated by said first transmission element.

Claim 6

An apparatus for controlling the molten metal level in a mold of a continuous casting installation, comprising a first regulation circuit for the regulation of the infeed of molten metal to the mold, said first regulation circuit comprising reference value-adjustment means for presetting a reference value of the level of the molten metal in the mold, a comparator in circuit with said reference value-adjustment means, a first transmission element in circuit with said comparator, an adjustment element for adjusting the flow of metal into the mold in circuit with said transmission element, and output means connecting said transmission element with said adjustment element for transmitting adjustment signals thereto, a second regulation circuit for regulating the withdrawal speed of the cast strand from the continuous casting mold, said second regulation circuit incorporating a comparator, a second transmission element in circuit with said comparator, and an adjustment element for adjusting the withdrawal speed of the strand from the mold, measuring means for determining the degree of filling of the mold, both regulation circuits being connected in parallel with said measuring means, a function generator operatively connected with said measuring means and said second regulation circuit, a reference value-adjustment means for presetting a reference value of the withdrawal speed of the strand operatively connected with said function generator, and means for altering the reference value of the withdrawal speed in dependence upon adjustment signals generated by said first transmission element.