Thyssenkrupp Uses Airknives To Reduce Energy Costs

Airknife Drying SystemDuring the manufacturing process of steel strip, at the ThyssenKrupp plant, scale has to be removed from the strip’s surface before it passes through the rolling mill.

To achieve this de-scaling, the strip passes through an acid ‘pickling’ bath. The acid is then neutralized by passing through a ‘washing’ bath. Afterwards, the strip is dried to avoid the risk of corrosion. To perform this drying process ThyssenKrupp has installed a blower powered airknife system from Air Control Industries (ACI) which has resulted in significant energy savings and consequent cost reductions.

Previously this was done by the company blowing air that had been heated to 120oC via a steam heat exchanger across the travelling strip.

Now, the new system installed by ACI’s German distributor Carl von Gehlen Spezialmaschinen und Zubehör GmbH & Co. KG of Mönchengladbach achieves the required drying duty whilst reducing blower energy consumption by 50% and completely eliminating the steam powered air heating system.

The decision to install the ACI airknife system came after extended technical discussions between the two companies to determine the positioning of the airknives and how to protect the airknives in the very corrosive environment. The result has proven to be an effective solution that has now been operating for more than a year.

The strip steel at the ThyssenKrupp Dortmund Beta plant is primarily for the automotive industry. It is engineered to bespoke requirements for many different vehicle manufacturers to meet specific performance requirements. The complex production processes, including special tempering, permit body parts to be made up to 30% lighter, including crash-relevant parts.

The ACI airknife system designed by Carl von Gehlen includes 4-off 2000mm long 316 stainless steel airknives powered by a 45kW EV blower which is housed in an acoustic enclosure.

A special feature of the installation is custom-engineered steel enclosures for the airknives that provide protection from strip damage.