Highest performance at the highest temperatures

The energy transition brings new challenges for wind turbine manufacturers: Increasing capacities require ever larger components. Gusszentrum Ostfriesland GmbH is therefore producing ever larger machine carriers, rotor hubs and stator bells for parent company Enercon GmbH. In order to be prepared for the future, GZO, based in Südbrookmerland, East Frisia, is modernizing numerous crane systems. A major project involving all production areas of the production site. Konecranes designed a total of six new double-girder overhead cranes for the molding shop, foundry and casting post-treatment, loaded one crane, dismantled three cranes and relocated four existing cranes within the halls. The conditions require particularly robust cranes: the new double-girder overhead traveling cranes are sometimes exposed to extreme heat and high levels of dust.

Redundant drives safeguard the casting process

Hot work at the melting point: To cast wind turbine components such as machine carriers, rotor hubs and stator bells, the workers at Gusszentrum Ostfriesland GmbH use molten nodular graphite.

The most powerful new CXT double girder bridge crane in terms of load capacity, with a lifting capacity of 100 tons, is used in the moulding shop. Two parallel wire rope hoists, each with a load capacity of 50 tons, jointly lift the sand core casting moulds to their position in the GZO foundry. There, the new foundry crane with a lifting capacity of 85 tons, a span of 24.50 meters and a lifting height of 13 meters fills up to 50 tons of liquid nodular graphite into waiting casting moulds. "We have equipped the double-girder bridge crane with redundant drives, four drive motors and two frequency inverters in each of the crane and trolley trolleys. The hoist unit is also completely redundant. This ensures that the crane with the ladle crossbeam can continue working in any case and that the molten metal does not cool down and become unusable," explains Ralf Baresel, Sales Heavy Duty Cranes at Konecranes in Berlin. The electrical system is housed in an air-conditioned container on the crane. The foundry crane and ladles can also be remotely controlled from a separate cabin crane, which has been moved to a new position on the crane runway. Also relocated to the end of the crane runway, the old foundry crane serves as a support during maintenance work, for example. In addition, a new double-girder bridge crane is now used in place of the furnace crane. "The new furnace crane can now transport heavier loads of up to 30 tons," says Ralf Baresel.

At a safe distance: the crane operator controls the new foundry crane from Konecranes with a lifting capacity of 70 tons on the ladle beam by radio and at the same time directs the ladles with molten mass.

After casting, GZO employees in the demoulding area remove the cooled component blanks from their sand molds - this creates a lot of dust. The new Smarton process crane with a load capacity of 63 tons is therefore specially protected. "All of the Smarton's electrical systems are housed in a control cabinet outside this area of the hall," explains Ralf Baresel. "With its additional dust covers on the motors, the crane is well suited to these harsh conditions. We dismantled the old 40-tonne crane in the demoulding area and increased the load capacity of the transport crane in the adjacent blasting cabin to 38 tons."

Reinforced rope drives for harsh conditions

At the end of the production process are the finishing and casting post-treatment stages. In the finishing area, a CXT double-girder bridge crane with two wire rope hoists and a lifting capacity of 40 tons now lifts the wind turbine components, which previously transported casting moulds in the moulding shop. In addition, a 30-ton CXT double-girder overhead crane replaces its 20-ton predecessor.