Pickling vats for continuous steel strip - with strip feed at entry and exit controlled by ultrasonically measured strip sag in first vat

摘要

The arrangement is intended for pickling hot-rolled steel strip which is passed through successive vats filled with pickling acid and then through vats with rinsing water followed by drying and winding. The speed of the strip at entry to and exit from the vats is controlled as a function of the strip saq in the first vat. This sag is measured by means of an ultra-sonic transducer arranged at the bottom of the vat. The entry and exit speeds may be controlled by varying the speeds of respective feed rollers whilst the acid and temperature-resistant transducer radiates upwards from the centre of the vat bottom. Used in continuous steel strip pickling. Ultra-sonic measurement is not subject to the limitation of measureable height above the instrument as in the case with inductive measurement whilst the degree of coupling is independent of the dimensions of the strip.