Automation for the scale breaking and/or descaling of slabs: improved quality for hot rolling processes in the steel industry.
Prior to the hot rolling of steel, the scale (ferric oxides) arising from oxidation needs to be thoroughly removed from the surface of the slabs. The procedure is decisive for the quality of hot rolling products. Rolled-in scale reduces steel quality.
In the scale breaker or descaler, high-pressure water jets (100 to 400 bars) are used to blast off the scale layer from the surface of the rolled material. The nozzles are mounted onto several nozzle manifolds.
In order to obtain optimal results, numerous parameters in this hydro-mechanical operation such as spray water distribution, volume flow and jet width need to be monitored. For this, pumps and valves must be controlled in real time. Eckelmann has for many years developed automation solutions for sophisticated applications of this kind.
It is essential that the head and foot of the slab are prevented from cooling down and that inhomogeneous temperature distributions are avoided. For this, hot metal detectors are used to identify the position so that the descaling of the slab starts and ends at the right moment. Material tracking during the entire descaling process is included in the automation.
In order to prevent the slabs from cooling down too much (particularly in the processing of thin slabs), the control technology ensures that as little spray water as possible is used, without detriment to quality.
The controls in Eckelmann's numerous reference projects are based on SIMATIC S7.