Multi-strand continuous casting - where electronic timer closes tundish nozzles so only last billet cast has short tail-end

摘要

Device for controlling a multi-strand continuous casting plant where a tundish with several bottom holes feeds several chilled moulds from which the hillets are drawn and either worked or not worked prior to cutting to length. For each strand, a timer is provided with a variable resistance combination for adjusting the billet length, and guide-rolls on the billet drive a tachogenerator providing a control voltage proportional to the billet speed, the voltage being fed to the timer which is also linked to a pulse-generator controlled by the shearing device which generates a starting pulse; and on the output of the timer is a switching amplifier which is self-locking and generates a periodic control signal sequence which determines the closing time of the outlet nozzles on the tundish. Optical and acoustic signals are pref. included. Provide optimum distribution of the metal in the tundish where the stoppers are closed w.r.t. time so that only the last part of the last billet is an undersize length.