Heat and dust: energy supply system for indoor crane under adverse conditions

Profile

• What was needed: Pre-assembled energy chain for use in a heavy-duty application
• Requirements: Tight installation space, resistance to high temperatures and heavy soiling, trouble-free operation
• Area of application: Steel industry
• Success for the customer: Quick assembly on the crane bridge by delivering the filled energy chain on transport drums. The very compact chains also do not have to be dismantled or packed for onward transport to the place of use.

A double girder overhead travelling crane in Thyssen Krupp's Duisburg hot rolling mill removes the freshly produced slabs, which are then processed into steel strip, stores and removes them and feeds them to the holding furnaces. It travels at speeds of up to 120 m/min on the 500 metre long crane track. In the trolley drive, speeds of 60 metres per minute are achieved, whereby the crane operator can move the cabin over almost the entire length of the bridge. For space reasons (the installation space is limited at the top), the entire control system had to be housed in the bridge rather than in an external control room so that the trolley travels between the two bridge girders rather than above them. In addition, all components used had to be designed for heavy-duty operation. The crane is constantly exposed to high levels of dust and high temperatures. The slabs and the holding furnaces radiate so much heat that temperatures of up to 70°C are reached even just below the hall ceiling. The moving cables for electrical power and signals as well as the energy chain must therefore be designed to withstand the adverse conditions in order to ensure trouble-free operation under these extreme conditions.

In view of the requirements, the igus® engineers recommended a type 5050RHD roller energy chain for the energy and signalling guidance on the crane bridge. The chain system used for "Heavy Duty" applications is characterised by reinforced side parts, additional wear surfaces and a pin bore system that has been reinforced by around 40 percent. This means that even heavy cable weights - in this case 13 kg/m - can be reliably guided and moved. The chain length in this case is 17.8 m, with the system travelling over a distance of 15.5 m. Cables from the chainflex® product programme from igus® were also used. A TPE sheathing ensures that all cables can withstand the high temperatures in the trade show system. Based on the special requirements for the energy chain and cable, the chains were designed and supplied as pre-assembled readychain® Basic systems . The cables are inserted, but not completely pre-assembled and equipped with connectors. As the cables are wired to terminals, no connectors are required. In addition, the cable lengths cannot be specified to the centimetre for such a special project. Flexibility during installation is more important. Only the fibre optic cables were pre-assembled with connectors.