JPS5729520A - Top-and-bottom-blown converter - Google Patents

Abstract

PURPOSE: To enhance the performance of controlling the final temperature of a molten steel and the final carbon content by a method wherein a synthetic control is conducted by combining a static control to set a program based on charging conditions and blowing-out conditions with a dynamic control utilizing process signals obtained during a blow refining operation.

CONSTITUTION: Based on signals from a condition setter 26 and information of past runs, a reference calculator 27 calculate the variation amount of the target amount of oxygen accumulated in slag and feeds it to a blow refining controller 25 so as to determine and adjust the height of the lance, the amount of oxygen blown in and the amounts of auxiliary materials (generically referred to as L amounts). Then, the blow refining is streated using a lance 2 and a bottom nozzle 3, the data from a calculator 28 for the amount of oxygen accumulated in the slag are inputted into the controller 25, and the controller 25 determines a correction amount for the L-amount reference values and corrects the values. Immediately before the blow refining is completed, a correction operation command device 30 estimates the final molten steel temperature and the final carbon content on the basis of the actually measured values of molten steel temperature and carbon content which are obtained by an apparatus for a bubslance 4 and on the information of the amount of oxygen accumulated in slag which is fed from the calculators 27, 28, and the L- amounts and the flow rate of CO₂ or an inert gas are corrected toward the target values through the controller 25.

COPYRIGHT: (C)1982,JPO&Japio