Automation of control for steel re-heating furnaces in variable production rates

Abstract

Automation principle, tested and applied on SACILOR mill furnaces The process described here takes into account the following

• 1 - The real time-rate of the furnace métal-discharge, which is the variable of the response-curve for variable rate.

• 2 - The transfer functions that are proper to the furnace are experimentally assesed. According to the applications, we take into account variable elements such as:

• - product size

• - charging temperature

• - final temperature and required homogeneousness of the product

• - heating curve corresponding to given range of heating rates.

The model computes the necessary heat flow and optimizes its distribution between heating zones. Direct mesures enable to assess with accuracy the variations in the elements of the heat balance. In doing so, we introduce the corrections making up for slight changes in the yield and even some measuring errors. The classical references for temperatures become alarms only.