Development of Interstand Velocimeter for Hot Strip Finishing Mill

To measure accurate strip velocity between stands of hot strip finishing mill is effective in keeping the stable production and improving the strip dimension control accuracy. We have developed accurate and stable strip velocimeter using laser Doppler velocimeter in tough environmental conditions where heavy steam, mist and spray occurred at high temperature at interstand of hot strip finishing mill. Two laser Doppler velocimeters were installed at F4 stand exit and F5 stand exit, and were evaluated for their durability and measurement accuracy. The F5 stand mass flow gauge was calculated by using the F4 stand exit gauge and strip velocities measured by these velocimeters. The evaluation results indicated that the mass flow gauge were measured within plusmn0.46% accuracy and would be able to be applied to the mass flow AGC (Automatic Gauge Control) at the hot strip finishing mills