COMAINTEL’s Induction Roll Heating Systems Address issues of Shape and Gauge Profile Control
Achieving the best possible flatness is usually one of the main objectives of Cold Rolling. However for most alloys, the edges of the sheet will be slightly thinner than the center (Positive Crown) usually observed at the beginning to the Rolling process and afterwards the thickness of the edges will increase due to uneven temperature distribution (Wedge Effect).
Rolling Mills are equipped with mechanical systems (e.g. Hydraulic Pistons) and Lubricant Systems (e.g. Zone Cooling Sprays) to try to improve Gauge Profile Control.
Production and Operational Issues:
Even with all the existing actuators used to control the Flatness and Profile issues, the Gauge Control Systems regularly doesn’t address the Quality Output requirements.
- Edge Cracking and Strip Breaks;
- Reduce coiling speeds (to reduce Edge Cracking and Strip Breaks);
- Premature wear of Work Rolls due to high negative bending pressure and reduced coolant spray at edges;
- Irregular Gauges along sheet through temperature variances along Work Rolls
Induction Roll Heating is applied to the Work Rolls (WR) to increase zoned independent WR diameter (using induction heating) to control flatness where the Actuators and Lubricant Systems can’t control sheet gauge (often required at the Work Roll edges). The Induction Heating technology has proven to be very efficient and cost effective bringing a quick ROI.
Based on Rolling Mill implementation of Comaintel’s Induction Heating technology, it has generated many benefits:
- Reduce Down Time with less Edge Cracking and Strip Breaks;
- Increase Mill Speed sharply;
- Significantly reduce Crown and Wedge Effects;
- Reduce Bending force allowing less Work Roll wear;
- Up to 90% Power efficiency;
- Significant reduction in energy costs compare to conventional hot lubricant sprays;
- 30 mm Opticoil 6kW and 30 mm Opticoil LC 12 kW (Most powerful in the market);
- Opticoil LC: Liquid Cooled for more power and increase Work Roll temperature;
- ROI in just a few months.