Level control of blooms before descaling
Customer / Field / Equipment manufacturer
Steelworks / Production of semi-finished steel products.
Hot blooms of different sizes travel on a roller conveyor in undefined position (not guided).
Conveyor width 1000 mm approx..
Blooms height can vary from 110 up to 280 mm.
The end user needs to check if the bloom head is bent to avoid damage of the subsequent descaler. As blooms of different heights are transported, also control lines (light barriers) at different heights are necessary. Manufacturer decided to build up a level control similar like a light grid. Based on the bloom height being transported, the PLC monitors the light barrier line which is expected to be interrupted and also the one lying right above. If also the superior beam is interrupted, a bow of the bloom has been detected.
5 through-beam barriers were used to create a light grid with five height levels according to bloom sizes. To avoid mutual light interference, they were horizontally staggered along the conveyor. The use of OL 19 tube was recommended to create a most defined (thin) line. Transmitter and receiver were arranged so that two side by side installed light barriers always had opposite beam direction: Emitter and receiver look alternatively from right to left and from left to right.
Advantages compared to previous solution or competition
Robust housing and reliable sensor function also at steam and spray mist and because of the high temperature environment, which usually affects common light barriers negatively.