At the Eschweiler waste incineration plant, igus has replaced the existing trailing cables with an energy chain that was developed from the ground up for use in adverse environmental conditions. The installation of the chain on the 70-metre-long crane track placed high demands on logistics and coordination because it was carried out while the incineration lines were in operation.
When the Weisweiler waste incineration plant went into operation in 1996, it initially opted for a classic festooning system. The plant, which is designed for a throughput of 360,000 tonnes per year, is still one of the most modern waste incineration plants in Germany. It has three incineration lines that are fed from a central bunker. The furnaces are fed by two cranes that travel on a common 70-metre-long crane track and have a span of 25 metres.
The operators were not 100% satisfied with the trailing cables used to supply energy to the cranes because wear was noticeable due to the very abrasive dust. The bending at the same points always creates 'predetermined breaking points', so that you have lost some cores. In addition, cleaning such cables is difficult or even impossible. The energy supply system in the plant is extremely stressed because the cranes work around the clock with very high dynamics without a stop. The changing humidity that prevails in the bunker also places high demands on a solution. In addition, two further challenges remained to be solved for the successor system. The first: the replacement had to take place while the incineration lines were in operation, so there could only be short interruptions when the cranes were not feeding the furnaces. The second: Since the manufacturer of the cranes had ceased operation in the meantime, the documentation was incomplete and had to be reproduced.
The energy chain specialists from igus were given the opportunity to present their roller chain type rol e-chain. The rolling instead of gliding "rol e-chain" can handle long travels and high speeds with low drive power.
However, those responsible for the waste incineration plant remained sceptical in using plastic material in the plant. However, the energy chain specialists from igus succeeded in dispelling this scepticism - among other things by jointly visiting another waste incineration plant where a chain of this type has already been in operation for almost nine years. The rol e-chain systems were not only installed on the crane track, but also on the 25-metre wide crane girder. The appropriate troughs come from the standard igus range, but were manufactured in 316 stainless steel to take account of the harsh environmental conditions.
The missing documentation of the crane cost about two months of work. The igus technicians have checked which task the respective cables fulfil and created an up-to-date e-technology plan on this basis. At the same time, preparations were made for the conversion from flat to round cables. igus finally presented a "customised" design; the moving end arm for the energy supply of the trolley was also individually adapted. The igus technicians worked in three shifts for fourteen days to install the energy chain. This was followed by two days for commissioning, during which every single cable and the control technology elements were tested according to VDE requirements.