Machine Vision for Slab Concast Inspection

The speed and dimensions of concast steel are typically measured mechanically. The JLI Slab Concast Inspection System eliminates the contact wheel and manual measurement procedures. The accuracy is 0.1% on speed, 0.5 mm on thickness, and 2 mm on width. This data and information enable the steelworks to cut slabs to an exact weight.

Instrumentation for the concast plants presents tough environmental challenges. The JLI vision system utilizes water-cooled camera housings with air-purged heat-reflecting front glass.

The system measures the thickness, width, and speed of the red-hot steel. Three cameras are used for each strand. One camera is mounted at the side looking directly at the surface of the slab to gauge thickness. Two cameras are mounted at the side looking down at a steep angle to measure the width at the bottom of the slab.

The camera looking at the side records the pattern of the scale and follows this through the image. Thereby the casting speed is measured. Knowing the density, the measurements of volume are converted to weight. When a pre-programmed amount of steel has passed the cameras, a signal is given to clamp the torches to cut slabs at the exact weight.