PPPL(push-pull pickling line) is used for cleaning the HRC surface through the reaction of HCI and ferric oxide. At the entry of the line is equipped with coil car, which deliver the strip from coil saddle to the drum of payoff reel. In order to guarantee the flatness of the strip threading, A 9-roll straightener will be allocated on the entry of pickling section to level the strip head and cut the head &corner, then strip run into pickling trough. The chemical reaction betweenstrip surface and HCI is as following.
Acid mist on the pickling and rinsing section will be suctioned with micro negative pressure through exhaust tube to absorption tower（ARP）, and exhausted to outside after spraying and cleaning. Strip will be dried in hot air drier after rinsing section, the hot air is heated by steam exchanger. Coaxial type side shear is applied for slitting edge of strip, and a centering roll with pinch roll (CPC) is designed in the entry of side trimmer to control the position of strip on centering line, the scrap will be twisted as a dumpling and carried into a scrap bin. The recoiler is a cantilever tension reel, the tension force is erected by three-roll bridle. EPC is equipped in recoiler to control edge position centering. The exit coil car which is driven by hydraulic will carry the coil to coil saddle.