Austrian shredders look sharp
13 August 2008, News release from Riverside Waste Machinery
Untha has developed a sleek new generation of shredders for refuse derived fuel preparation.
Andrea Height finds out more...
It certainly doesn't look like your average shredder with its curvy lines. Some observers have suggested it has the look of a toaster. Untha says this new design has been developed in response to calls from refuse derived fuel (RDF) engineers for a new generation of secondary shredders. Having invited engineers to its headquarters in Austria, Untha quizzed them on what their ideal shredder would be. Perhaps unexpectedly, high on their wish list was 'aesthetically pleasing', along with a shredder needing little maintenance, with easy access for changing wear parts and a high output rate.
Untha's solution was its TR Shredder Series, which it officially launched at the IFAT show in Munich, Germany in May this year. These single shaft shredders are said to be unlike anything on the market and specifically designed to suit the requirements of RDF.
Riverside Waste Machinery supplies the Austrian made Untha shredders to the UK market and its team has visited Austria for specialist training. Riverside sales executive Des Corcoran explains that the shredders are "unlike anything anyone has built before" and Untha has filled what was a gap in the market for a shredder that could reduce high volumes of material to less than 30mm. His predictions for the shredder are positive: "I know there is going to be interest in this as many reprocessors want to get down to 25-30mm particles to meet their customer's demands. If it were available now, we may have already sold around four units."
While the TR series has been launched, final tweaks are being made to the design, with production expected to start in August and first deliveries in December. Two facilities in Austria have the shredders in operation, where interested parties can see them in action.
What is it that makes these shredders different?
Designed to reduce mixed municipal waste for mono and co-combustion systems, the TR Series features an increased rotor diameter and enlarged screen surface to help facilitate throughput volumes up to 15t/h. To prevent jamming, there is a hydraulically operated gate, which allows the non-shreddable material and objects to be rejected quickly, without restriction. If the machine overloads for some reason, it has a reversing function that will eject the material. This prevents serious damage to the cutting system and screen, which in turn decreases down-time and maintenance.
Another clever feature is its patented quick change cutter system involving 800mm long cutters and holders which are secured by a single bolt, allowing quick replacement. The cutter and holder that have been removed can then be taken to a workshop where it can be turned four times, ready to replace the next one that wears out. This allows for cutter units to be replaced in a very short space of time, so reducing machine downtime and its associated costs.
Energy saving approach
Untha says its drive system was developed with energy saving in mind and it has estimated savings of up to 6,000 kWh per year against comparable shredders. For ease of maintenance, internal parts are easily accessible. The press of a button activates a hydraulically driven system, which opens up to expose the shredder's interior, allowing very convenient access to all wear parts. In particular, the cutter bars, drive system and exit screen are all within easy reach. About 70% of the parts are made in Untha's factory and it has a €4 million worth of parts in stock. In addition, its use of fibre glass covers help reduce weight and lower noise levels. Untha's history as a shredder manufacturer stands it in good stead. Back in 1970 founder Anton Unterwurzacher was asked to develop a machine to shred wooden and cardboard fruit boxes and the company has built on its knowledge and expertise ever since. "Untha has worked on improving the designs using engineers who could push the boundaries," Corcoran explains. If its approach has seen it move from fruit boxes to RDF in 35 years, it will be interesting to see what happens in the next 35 years.
How does it work?
During the shredding process, the hydraulic swingpusher feed system forces the material against the rotor carrying the exchangeable, four-edged cutting blades that shred the material against the cutting bars. The shredded material is then discharged through a perforated screen. The diameter of the perforations defines the granule size.
For further information please email Riverside Waste Machinery