Obtaining Reliable Information on Energy-Saving Regimes for the Heating of Continuous-Cast Semifinished Products Prior to Rolling

Reducing the amount of fuel used to heat continuous-cast semifinished products before rolling is an important problem in modern high-speed rolling operations. The heating furnaces of high-speed rolling mills are usually operating under nonsteady conditions, which makes it difficult to realize energy-saving regimes for heating the metal. Modern continuous furnaces are multi-zone units, and the prescribed temperature regime in each heated zone is maintained by controlling the consumption of fuel. From the standpoint of responsiveness and accuracy in obtaining the desired quality of heating and — in particular — reducing fuel consumption, the most promising approach is to instead control the temperature regime in the different heating zones on the basis of the temperature of the surface of the metal. The metal's surface temperature is most accurately measured using optical pyrometers installed in a side wall of the furnace. The article presents a block diagram showing how an energy-saving regime for heating continuous-cast semifinished products can be implemented in a modern continuous furnace on the basis of the temperature of the surface of the metal tsfc(τ).