Use of optimized descaling nozzles on the wide hot strip mill of Thyssen Krupp Stahl AG

Flawless descaling during the hot rolling process is crucial for the quality of the finished product. Therefore, today descaling plants must work effectively, reliably and efficiently to comply with current demands. The optimized combination and arrangement of high-precision spraying nozzles make for economic plant operation. Within the multiple parameters determining the layout and the assessment of descaling nozzles the pressure of impact plays a central role. Further functional parameters include spray water distribution, pressure distribution of the jet, jet width angle and volume flow. The following article describes the nozzle types installed in the Bochum wide hot strip mill of Thyssen Krupp Stahl AG and reports about the experience made with these nozzles in practical operation. Only by changing the nozzle type and the distance between the nozzles and the rolled material could the efficiency of the descaling process be increased, namely by 35% in the roughing mill and 60% in the finishing mill.