Crucial for the flow
The overall efficiency of this CFB incinerator facility depends heavily on the specifications of the shredded and crushed waste. E.ON and M&J therefore co-operated closely at all stages of design, planning, installation and commissioning of the two pre-shredder units.
As a result, Benny Bromann, senior engineer at this E.ON facility, considers the two M&J 6000S-12 shredders among the most reliable heavy-duty equipment in operation at the plant. To date, they have been in service for well over 20,000 hours, with an up-time in excess of 98% throughout their six years of service.
E.ON Värme Sverige is a Swedish subsidiary of E.ON (the world’s largest privately owned energy group). The company operates one of the largest CFB (Circulating Fluidised Bed) incinerator plants in Europe – located in Norrköping in southern Sweden – with an annual capacity of approx. 240,000 tonnes.
In the light of such a distinctly positive long-term track record – as well as smooth, effective technical collaboration on constantly fine-tuning, optimising and improving shredder performance – the management of E.ON Värme Sverige opted to take an important next step in boosting waste processing efficiency at its plant.
In 2008, the company decided to replace one of its two hammer mills with a completely new M&J secondary shredder configuration, operating downstream from the two preshredders.
The new M&J shredder unit consisted of a single M&J 6000S-16, which was delivered and installed in August 2008. This completely new configuration has a patented cutting table fitted with 2×16 knives rather than the 14 previously available as the maximum. These 16 knives also feature a new shape, specially designed for this particular task, in which the input normally consists of 50% household waste and 50% commercial waste.
Because these secondary shredding processes are so important for E.ON operations, the contract featured a series of specific performance targets, including a maximum of 11% for grains over 100 mm in size. E.ON Värme Sverige also stipulated that compliance with these stringent contractual requirements was to be verified by an independent analysis company.
Meeting and exceeding targets
Once the new set-up had been installed and run in, the German specialist company Kanthak & Adam GbR was commissioned to determine the particle size distribution of shredded waste samples, using screen analysis techniques. The tests documented a capacity of 62.5 tonnes per hour, with a maximum of particles over 100 mm as low as 8%.
These and other tests provided independent verification that the performance of this new M&J shredder configuration is significantly better than required. Spot checks have shown consistent grain size results as low as 6.5%, in addition to a capacity almost 25% greater than the contracted target.
This key order, and its successful implementation, in a manner that exceeded the customer’s stipulated performance requirements, also places M&J Industries firmly in the frame for future secondary shredding projects worldwide.