The System of precise stop and passing defects through the mill stand in the reversing mill stand 1200 Metallurgical Plant
After hot drawing and pickling of rolls steel surface has many asperities, leave alone the fact that during the pickling in continuous units rolls are welded together and seams are formed. Whereas, when a defect or suture enters the mill stand, it is necessary to reduce the speed of the strip to prevent deformation of the rollers and provide better rolling. One roll can be rolled in a reversing mill to 3-7 times (passages). During the first pass, the speed reduction is carried out by the operator (notes defects). The automated system detects defects and on the next pass will automatically reduce speed during their passage through the cage.
- Client JSC "Zaporizhstal"
- Skills Automation
- Website https://www.zaporizhstal.com
Project Starting Date
On reversing mill 1200 of «Zaporizhstal» plant is installed the four-rolls stand with working rolls with a diameter of 430 mm and supporting 1300 mm. Working rolls are driven by electric power of 3200 kW through pinion stand and rotate with the maximum circumferential speed of 10 m / s. During the rolling the working roll’s speed does not exceed 8.5 m / s. The mild steel 08kp (ps) rolled in the rolling mill with the size of 0.6 x 1030 mm (a tin semi-finished rolled stock) and 0.5 x 1,020 mm. The hardware-software complex of a precise stop and passing through defects in the stand reversing mill 1200 is intended for automatic control of round the clock exact stop at the end of the roll.
The following effect was obtained as a result of implementation of the system:
- improving the reliability of the machine work by applying modern microprocessor-based means of automation and as a consequence, reduced downtime of production equipment and consumption of energy resources through the fault of failures in an outdated control system;
- increasing the productivity of the machine by automatic and accurate stop and reversing of rolling;
- increasing productivity of the machine by automatic reducing the speed of the rolling mill when it passes the defects through the stand and minimize the rolling time on low speed;
- providing «bumpless» exploitation of mill rolls by automatic reducing the speed of the rolling mill when it passes the defects through the stand as well as a precise stop;
- more efficient use ejector and equipment by reducing the downtime of production equipment and consumption of energy resources through the fault of failures.