Zuser Ressourcenmanagement GmbH is not keen on experiments: for the past 24 years the RDF producer in Peggau, Austria has bought shredders made by Lindner Recyclingtech. The new addition to the family is a Polaris 2800. For one-step shredding every other machine was simply out of the question.
The cooperation with Lindner dates back to a time before Mag. Georg Zuser became CEO of the Zuser Ressourcenmanagement GmbH. Back then, i.e. in 1993, thermal recovery of waste had only just started in Austria but the shredder producer was already on the market. ‘It was a very limited supplier market’, he remembers. The loyal Lindner customer and SRF producer who is convinced that ‘With Lindner, you know what you’re getting’ now owns a Jupiter primary shredder (with 145-millimetre knives), the two secondary shredders Komet and Komet PK (with 30-millimetre granulate size) and since January 2017 a Polaris 2800.
‘We didn’t want to risk trying anything new so we stayed with Lindner as our tried-and-tested supplier’
Mag. Georg Zuser
For one-step RDF processing no machine on the market other than the innovative single-shaft shredder was good enough. ‘We didn’t want to risk trying anything new so we stayed with Lindner as our tried-and-tested supplier’, explains Georg Zuser. The enormously powerful double belt drive, the high flywheel mass, the optimised feed system (internal pusher for higher feeding capacities and easy feeding), the hydraulic maintenance door (allows for fast removal of foreign objects and easy rotor maintenance) as well as the robust and durable rotor knives won over the group, which also operates in the wood waste sector. Designed as a universal shredder, the new Polaris series made by Lindner shreds almost every material.
Before the decision for the Lindner Polaris 2800 was made, a test machine from the series was trialled at the operating site. In real-life conditions, different materials were shredded and the output performance and quality analysed. Put to the acid test, you might say. At its headquarters in Peggau, North of Graz, Zuser produces over 100,000 tons of RDF & SRF from municipal solid waste, commercial waste, industrial and mixed construction waste with grain sizes ranging from 30 to 250 millimetres. The company has 5 sites with 150 employees in total in Austria and supplies cement plants and other industries in Austria and neighbouring countries. SRF with high calorific value is shipped for example to the main kiln in a cement works, RDF with medium calorific value to calciners and material with low calorific value to waste incineration plants.
The material comes from Austria, Slovenia, Italy and right now – due to shortages – also from Germany, says Georg Zuser. Mostly the material is delivered by waste disposal service providers unable to treat the waste. According to the company, less than ten percent of the company’s revenue is generated by their own municipal waste collection. In the process of producing RDF & SRF, ferrous and non-ferrous metals as well as recyclable plastics are separated and sold. To put it in the words of André Riemer, head of maintenance at Zuser, everything that limits or reduces the calorific value is eliminated. However, high-quality waste wood is not only thermally recovered but also used for chipboard production.
The Polaris 2800 shreds 28 tons per hour of relatively heavy municipal solid and commercial waste with high bulk density and a defined output grain size of 80 millimetres – and that in one step instead of two. ‘We’ve never had any better machine than the Polaris for shredding high calorific material’, confirms André Riemer. The Polaris 2800 was delivered with an innovative rotor system and runs smoothly and without any glitches. André Riemer: ‘The knives and knife block are very sturdy. Since putting the machine into operation, we haven’t had a single fault. That’s incredible, we never had anything like this with other machines. And we have almost no problems with foreign objects. Sometimes we have to take some bigger iron elements out of the Polaris, but otherwise the machine runs smoothly. I think it would be possible to operate the machine for approximately 400 hours without having to change any wearing knife parts.’
Furthermore, the Polaris series has the lowest ratio of energy consumption to euro per ton compared to similar single-shaft shredders on the market. An important economic aspect for André Riemer, though he admits that ‘it depends on the input material: sometimes there are spikes in energy use.’ Zuser carries out the maintenance for all Lindner machines themselves. The producer’s maintenance team only changes the rotor bearings if necessary. The CEO Georg Zuser is already planning his second SRF plant and has been in touch with Lindner Recyclingtech, because you can’t have a plant without reliable shredders.