Copper as a material
Copper is one of the oldest metals used by humans and is still an integral part of electrical and pipe installations and the automotive industry. The properties of copper are valued everywhere. These primarily include good formability, strength, resistance and excellent thermal and electrical conductivity.

Founded almost 200 years ago as an art and bell foundry, Wieland-Werke AG, based in Ulm, has developed into a globally recognized supplier of over 100 copper and copper alloy materials. Both conventional and innovative copper alloys come from the company's own foundry and contain zinc, tin and nickel as well as copper. In the new and further development of materials, products and processes, the long-established company focuses on current customer needs and global trends such as sustainability, energy efficiency and e-mobility.

The Wieland Group is the only manufacturer of semi-finished copper alloy products to have an accredited testing laboratory in accordance with DIN EN ISO/IEC 17025:2005. The company also makes a significant contribution in the field of standardization with regard to the definition of product and testing standards. Particular attention is paid to the development of materials that enable the efficient use of resources and serve to protect the environment and health. This is made possible above all by close cooperation with customers as well as institutes, research facilities and other recognized partners, such as ACE Stoßdämpfer GmbH in the application described below.

The goal: Taming four tons of metal
On the one hand, the optimization of a dross sorting system is a good example of the economic, cooperative partnership between two companies that are leaders in their respective fields. On the other hand, a dross sorting system is also an important component in the ecological use of resources. "It is used to separate the metal-dross mixture and thus ensures that as much metal as possible can be processed further," explains Felix Scherb, Project Engineer at the company headquarters in Ulm. "If the system then has to be maintained and repaired at unsightly regular intervals, this counteracts our efforts to work effectively and sustainably."

However, this was precisely what was observed in the first few months after commissioning. The reason for this was quickly identified. After the metal content was separated into different grain sizes using sieve chutes, the metal spurs with a mass of up to 4000 kilograms landed in a discharge hopper. From there, they landed in free fall and with a loud bang at the end of a 2.3-metre-long path in a massive steel collecting structure that resembles an oversized drawer.

At the aforementioned drop height alone, the pure metal mass, which amounted to 500 kilograms even at the lowest drop, placed too much strain on both the drawer and the part of the overall structure underneath. During operation, the solid structure of the discharge hopper was regularly destroyed. According to Felix Scherb, two factors were decisive for a quick remedy: "Firstly, our company always gives us a lot of freedom when making technical decisions and secondly, we have been working with ACE Stoßdämpfer GmbH for many years, who have often helped us with proven damping solutions. This is also the case here."

Embedding a giant drawer more gently
When Felix Scherb contacted Udo Fischer, ACE's technical customer advisor in the south-west region, he had two possible solutions in mind for protecting the drawer and the overall structure: shock absorber plates from the Slab series or, alternatively, Tubus structural dampers. After considering the most important characteristics, which in addition to weight and drop height included above all the cycle rate of eight impacts per hour, the result was a large-scale use of Tubus type TC137-90. In the end, a total of 20 of these safety dampers were installed, on which the drawer now stands, into which the metal chunks fall from the discharge hopper.

Taminglarge masses
ACE's tube safety products for taming large masses primarily include the TC-S and TC product families. Both represent cost-effective solutions with high force absorption. The maintenance-free machine elements cover energy absorption from 450 to 17810 Newton meters and, thanks to their high spring rates, are used not only in loading and lifting devices and hydraulic equipment, but also in crane systems.

The enormous range is due to the dual concept of the TC-S family, but the force absorption of the individual TC types from 1210 to 14140 newton meters is also perfectly adequate for many designs, especially as they can be easily bolted into steel profiles in five rows of four, as in Ulm, thanks to their compact design. The type TC137-90 used is one of the largest models of the safety dampers with diameters ranging from 64 to 176 millimetres. With a stroke of just 90 millimetres, a single one of these models can already absorb forces of 6,350 Newton meters with standard damping, and even 8,890 Newton meters are permitted for emergencies. As with all ACE products, numerous accessories and connecting parts ensure easy integration into existing designs. And since their installation in the Wieland-Werke AG dross sorting system, the 20 tubes mounted in series have been absorbing the forces evenly and reliably. According to Felix Scherb, this means that considerably longer maintenance intervals are now possible and there have been no more breakdowns. dsc