Metal Industry Enters the Age of Superconductors
June 11, 2008 (H28). We highlighted earlier the award-winning induction heater for metal industry (see H23) developed by Zenergy Power GmbH and Bültmann GmbH, both of Germany. A brief technical description of this new system is included in paper RN6. We now learned that first such system worldwide was sold to Weseralu GmbH & Co. KG, a specialist manufacturer of precision aluminium profiles based in Minden (Germany), while a second unit has been ordered by a major player in the market for copper semi-finished goods.
Zenergy GmbH, located in Rheinbach, specializes in high-temperature superconductors (HTS) and their industrial scale application. It develops and markets HTS applications in cooperation with conventional technology partners and is a supplier of HTS wires and coils. The company formerly known as Trithor GmbH is a subsidiary of Zenergy Power plc, London, a stock quoted enterprise founded in 2005 to integrate three HTS companies in Germany, the US and Australia. Bültman, of Neuenrade, is a world market leader in metal forming technology with core competencies in machine building and plant design. The HTS system development project was supported by the German Bundesstiftung Umwelt (Federal Environment Foundation) where Dirk Schötz, Head of department for climate protection and energy technology, pointed out that the Foundation expects far-reaching positive effects of HTS-technology on efforts to globally reduce CO2 emissions. Dr. Carsten Bührer, the CTO of Zenergy Power, pointed out that „the HTS Induction Heater is the first industrial scale commercial application of high-temperature superconductors on the world market. The sales of the first two machines within only six months time underscore the innovative strength of our enterprises.”
Induction heaters are an established part of supply chains in the metal working industry. They play an important role in manufacturing semi-finished goods such as aluminium, brass, copper and copper-alloy pipes and metal profiles. In a precision heating process they soften raw material billets of non-ferrous metal in order to improve their ductility. Moreover, the heating process serves to obtain certain special properties in the end product. Through electromagnetic induction the machine generates eddy currents within the metal billet bringing it up to the temperature required. As an essential advantage, HTS induction heating generates predefined homogeneous temperature levels throughout a whole block of metallic raw material. Also, the HTS technology effectively prevents damages by local overheating as occurs in gas ovens or conventional induction heaters.
As reported in RN6, the new generation of induction heaters substitutes conventional copper coils by high-temperature superconductor coils. With conventional heating technology, only 35-40% of the of the energy input can be used to warm up metallic raw materials while 60% and more are lost. The novel HTS induction heaters reach heating energy effectiveness of 90% including all peripheral systems, thus cutting energy consumption by more than half. In addition, these new induction heaters offer significant advantages in process engineering, for example, by operating with similar efficiency at the push of a button and in continuous duty. Furthermore, HTS induction heating enables building up pre-defined temperature profiles within the material. This offers further quality improvements in metal profiles and pipes applied, e.g., by the automotive and aircraft industry as well as in machine, heat exchanger and window construction.