Continuous operation in waste bunkers

Energy chains and cables in harsh environments

Austrians generate around 3.5 million tons of waste per year. Nowadays, the waste is usually disposed of in thermal recycling plants, in whose furnaces temperatures of 1200 degrees Celsius prevail in order to recycle the waste as completely as possible. A sensitive system wherein plant failures would have enormous financial consequences. A scenario that Richard Krassnitzer, in charge of maintenance of the cranes at the Simmering special waste recycling plant, does not even want to conjure up in his mind. He therefore tries to play it safe as far as possible to avoid failures. Today, roller energy chains from igus are therefore used in the plant.
 

Profile

  • What was needed: Energy supply systems "readychain" including all necessary special parts, sheet metal and machine parts
  • Requirements: Heavy utilisation of the solution in continuous operation, heavy dust load in the waste bunker
  • Industry: Thermal waste utilisation
  • Success for the customer: Reliable chain system that also withstands the aggressive environmental conditions, provision of the ready-to-install system at the set installation date
Special waste recycling plant

Problem

As part of the maintenance of the cranes at the Simmering special waste recycling plant, the operators were faced with the task of procuring a new energy supply solution. Initially, this task was solved by trailing cables, which - after an initial maintenance-free period - triggered the first breakdowns after about half a year.  Sometimes the cable jumped out of the guide or it broke right away. With the sensitive system, plant failures would have enormous financial consequences; the process in a waste incineration plant consequently does not provide for any downtime of the waste bunker crane. It should work smoothly, 24 hours a day, 365 days a year. The capacity of the bunker is 40,000 cubic metres. The plant is working at full capacity and the cranes in the waste bunkers are in continuous operation. Their job is not only to receive the waste and stack it in the bunker, but also to load the furnaces. The operators are accordingly dependent on the cranes functioning permanently, if possible without maintenance.
Another challenge for the new solution: The heavy dust load in the waste bunker, so that protective clothing has to be worn on site.  The technology, on the other hand, has to take care of itself.  The moist dirt present, together with the metal particles it contains, means pure poison for any energy supply solution.

Solution

Meanwhile, the Lower Austrians rely on a rolling energy chain solution from igus. The two cranes of KW Kranwerke AG, which are equipped with the fully harnessed readychain energy supply systems from igus, now operate smoothly in the truest sense of the word.
In the energy chains, the cables are always routed in a controlled manner, which is very important, especially for data cables. The bend radius is specified by the chain. This prevents the shield from opening on shielded cables. However, the reference to the modest space requirements of the energy chains also falls on open ears on the user side: If the crane travel exceeds certain lengths, one may need more space for the cable station with trailing cables than the local conditions basically allow. This problem does not arise with the chain. Even with a distance of 200 metres, there is always room for its radius behind the trolley drive.
From the procurement of all necessary special parts, sheet metal or machine parts up to the provision of the ready-to-install system on the specified installation date, the customer has transferred his procurement logistics to igus. With its comprehensive product range, igus was able to reliably meet all customer requirements.
"The igus energy chains have never let me down. Three years after commissioning, the umbilical cord of the waste bunker crane still appears as good as new. Apart from the thick layer of dust, of course."
 
Richard Krassnitzer, in charge of crane maintenance at Fernwärme Wien
energy chain
energy chain

Before, After: The operator is thrilled with the difference.

"With the trailing cables, we were always struggling with failures. A lot of commands were transmitted over copper wires, and the border points were particularly vulnerable. We often had to tighten something somewhere and make sure that the individual clamps or wires were tight again. We always had 1000 metres of different cables stored to mend any breaks. During the repair work itself, we had to take regular breaks to load the furnace in between," recalls Krassnitzer of the time before he became acquainted with the igus system. Initial scepticism then very quickly turned into enthusiasm for the energy chain system from Cologne: "The igus energy chains have never let me down. Three years after its commissioning, the umbilical cord of the waste bunker crane still appears as good as new. Apart from the thick layer of dust, of course." And for Simmering's reserve chain, it's still 'please wait' - no emergency having occurred so far. If the forecasts of igus product manager Theo Diehl are anything to go by, this will not happen for years to come. This is because wear and tear is not a feature of energy supply systems from igus. A fact that Bernhard Bogner from AVN also appreciates. Although it has a maintenance dome for the waste bunker cranes, there is only one possible time for checking the longitudinally travelling chain each year: "Our main inspection. " Then there is a short break in waste delivery and incineration at MVA Dürnrohr.