"The high art of acid protection engineering “
The "Hohenlimburger Mittelband" plant owned by Thyssenkrupp Hohenlimburg GmbH consists of 4 pickling tanks and squeezing roll slots (which serve to keep the acid from the different basins separate.).
The push-pull pickling line is designed for flexibility: it can process strip thicknesses of between 2 and 16 millimetres, strip widths of between 150 and 750 millimetres and operate at a line speed of up to 2.5 m/s. The steel strip is stabilised by intermediate rolls (squeezing roll slots) which keep it in alignment. The process temperature of the hydrochloric acid pickling liquor is around 90°C. The coils weigh up to 17 tonnes and are used as the primary feedstock for later cold rolling or directly in the automotive supply industry, for example.
The Steuler Linings order (worth over 350,000 EUR) comprised two pickling tanks and a special component – and included a 10-year guarantee against acid penetration.
From a steel tank to the finished pickling line: The raw steel tanks were lined with two layers of rubber, vulcanised and externally painted in the custom colour "Thyssen Orange" at the Steuler linings site Siershahn. At the Thyssen site, the sections were then lined with two layers of tiles by six Steuler fitters. A total of 15 tons of acid-resistant stones and plates were used. Special attention was paid to ensuring adequate treatment of the many fittings and connections. The old sections were then lifted out of the plant and replaced by the new, for the most part, lined Steuler pickling tanks. The last step of the process involved connecting these sections in a corrosion-proof manner.
The downtime of the plant has been reduced to a minimum through efficient planning and preparatory work. All of the engineering work, from measuring and planning to design engineering and installation as well as disposal and connection work were successfully carried out by the Steuler Project engineers.