EEW Schwedt Plant Turns to Asynchronous Technology from Recycling Pioneer Lindner

Nestled at the edge of the Lower Oder Valley National Park, the  Schwedt power plant, which belongs to the EEW Energy from Waste Group, supplies the local paper  industry with electricity and process steam. In line with circular economy principles, the plant recovers  paper mill, commercial and industry waste. To optimally prepare the waste for the fluidised bed boiler,  the company relies on quality from Lindner. 

Kraftwerk Schwedt GmbH & Co. KG has specialised in recovering energy from waste since 2010. Highly  calorific SRF is produced from specially processed municipal solid, commercial and industrial waste. The  power plant, in turn, generates electricity, heating and process steam which is used to supply Germany’s third largest paper mill, whose waste is also used for energy recovery. Specifically, the Schwedt power plant  generates 175,000 megawatt hours of electricity and 602,000 megawatt hours of process steam annually.  

The high demands placed on calorific value and throughput require powerful and energy-efficient recycling  machines. Therefore, in spring 2020, the Schwedt power plant decided to replace a stationary shredder that  had synchronous technology and gearbox with Lindner’s Polaris 2200 and it’s tried-and-tested asynchronous  technology, countershaft drive and flywheel energy storage. The Polaris performed much better, offered  improved technical availability, mainly due to its drive concept, and led the company to replace another two  shredders in 2021 with Lindner’s Polaris 2200. 

According to an independent report by the University of Leoben (2017), a shredder drive system with an  asynchronous motor is more efficient than a drive system with a synchronous motor and produces up to double  the output per machine depending on the input material. The drive system with the belt-driven asynchronous  technology ensures optimum utilisation of the shredder’s capacity, which in turn leads to lower  production costs (€/t). 

At the Schwedt power plant, a total of three Polaris 2200 shredders have been reliably and efficiently shredding  33 metric tons of waste per hour in three-shift operation over 5.5 days a week since 2021. This corresponds  to 600 – 700 metric tons per machine every week. ‘We chose Lindner’s shredders based on the  recommendation of another Lindner client and were not disappointed. The Polaris 2200 has an efficient cutting  system and, after one year in full operation, has achieved a 30% higher productivity than machines with  synchronous technology in the past,’ says Steffen Künkel, Production Manager of Postprocessing at the  Schwedt power plant.

Not only is the Polaris 2200 extremely efficient but its heart, the rotor, is also highly accessible. This makes  maintenance work quicker and provides easy access to the screen. Regular maintenance work is an important  quality criterion and affects the homogeneous particle size and the consistently high throughput. At the  Schwedt power plant, maintenance is planned so that it is only carried out on one of the three processing lines  at a time. When one shredder is being maintained, the other two lines share the shredding load between them – the additional waste stream can be shredded seamlessly on the two Polaris 2200s that remain in operation.  The countershaft drive system harnesses the flywheel energy storage, which significantly reduces the acyclical  power required by the electric motor and also provides the additional power reserves required during peaks. 

Generally speaking, the Polaris can be used for a variety of applications. Although the material delivered to  the Schwedt power plant is predominantly free of FE parts, the input material might still contain unwanted and  difficult-to-shred objects. The robust shear cutting system is, however, resistant to non-shreddables, which in  turn positively affects the throughput. In terms of output material, the Polaris can achieve three-dimensional  particle sizes from 40 to 120 mm in a single pass. For the Schwedt power plant’s fluidised bed kiln, it produces  a particle size of 80 mm. Commercial, industrial and waste wood used to fire calciners in cement plants is also  shredded to the same size. That’s another popular application of Lindner’s Polaris series.