An oxide layer is formed on the steel strip in hot rolling. Before the steel coil is sent to cold rolling mills for further reduction, the oxide layer is removed by pickling process line and oiled for short storage. The process is based on conveying the strip through hydrochloric acid baths to dissolve the surface oxides formed during hot rolling of steel.
The most economical solution for the capacities up to 1 million ton is to install push pull pickling line before cold rolling mill wherein each coil is pickled and oiled individually. This avoids costly strip to strip welding and large accumulators requiring a huge space and expensive equipments. If required, we install scale breakers in the entry section to speed up the pickling process. Push pull pickling also helps to quick change product mix without affecting productivity.
We supply pickling lines for hot rolled steel strips for thickness of 1.6 mm to 12 mm and width up to 2000 mm.
The pickling tanks are shallow tanks made of specially contoured granite to permit fast free threading. Acid re-circulation Turbulent Acid System is used to increase the rate of pickling, reduce tank length and increase productivity.
Acid Washing Systems:
The special acid washing systems are provided after acid tank to ensure that the strips carry very low chlorides. It prevents mill oil deterioration in subsequent cold rolling.
Fume Exhaust System:
Special sealing of acid tanks and an efficient fume exhaust and scrubbing system ensures very low release of acid fumes. Our lines conform to the most stringent air pollution control norms.
Acid Re-circulation System:
We design and engineer the acid re-circulation system to ensure good pickling quality and trouble free performance. All acid recirculation tanks and piping carrying acid above 60 *C are made from FRVE. The system is designed to reduce specific acid consumption and least wastage through effluents.
Strip Washing & Drying:
Strips are rinsed in cold and hot water tanks to remove acid and air dried by specially designed hot ait system in the exit section.
Modernization and Revamping:
We have a vast experience in upgrading and modernization of pickling lines. We work closely with our customers to develop a tailored modernization concept based on their individual needs. Based on the detailed plan, revamp or modernization is carried out in several steps or during a plant shutdown with a minimum down time.