The main purpose of ladle furnace treatment

is to ensure that the molten steel has the required

temperature when the ladle is taken over at downstream

secondary metallurgy units or at a continuous caster.

A dynamic process model has been developed for the

on-line calculation of the temperature during the treatment

and for controlling the electrical energy input. The remaining

required energy input is calculated as a function of the

target takeover temperature and time of takeover at the

downstream unit. The temperature losses expected as a

result of as yet unperformed process steps, such as alloying,

stirring or desulphurisation, are taken into account within the

scope of a dynamic prediction. Depending on the time still

available, the model determines the optimum heating rate at

the appropriate voltage level required for the electrical energy

input.

Besides the temperature of the melt, the steel analysis is

also calculated on-line, based on the influences of alloying

element additions and desulphurisation.

Accuracy of the process model
(standard deviation of the modelling error)

Sulphur content	8 ppm
Temperature	4 K