High-efficiency gearboxes from Nord Drivesystems have helped Ken Mills Engineering (KME) to build the advanced processing machinery employed in a highly efficient new materials recovery facility (MRF) operated by Nordic Recycling Limited in Tilbury, Essex.
The new facility is Europe's largest single-line MRF. The processing machinery was designed by KME and is believed to be the most advanced of its kind in the UK. It features a large number of automated screening stages to enable the extraction of different types of dry recyclable materials. Additionally, the MRF incorporates of a number of automatic balers, all linked by a sophisticated feeding and materials handling conveyor system with a total length of several hundred metres.
Over 50 gearboxes from Nord Drivesystems drive the extensive materials handling system. Helical bevel gears were selected for the application, to optimise performance, providing an efficiency of over 95% — helping minimise the energy costs at the plant which typically operates for around 16 hours/day. This style of gear additionally runs very quietly, helping to reduce noise levels at the facility.
The MRF has a nominal capacity of 25 tonnes/hour, and is expected to process at least 100,000 tonnes of mixed dry recyclable materials a year, which might otherwise go to landfill. Around 50,000 tonnes of reclaimed paper is expected to be baled and shipped to Holmen Paper in Sweden for recycling into fresh newsprint.
The MRF machinery is designed to have a very long life of some 25 years, and part of KME's responsibility is to provide a 24/7 maintenance service. Consequently, when specifying the drive systems, reliability was a paramount concern. Good previous experience with the company's products helped KME to decide on gearboxes from Nord Drivesystems. KME had already used Nord Drivesystems' gearboxes at the largest MRF it had previously designed: a 15 tonnes/hour facility for Merseyside. In near-continuous operation since 2006, the gearboxes at this site have performed excellently and without a single failure. Another plus point came from the fact that KME's major supplier of screening systems already standardises on Nord gearboxes, providing a second reference on the product's reliability and quality.
“The demands of designing material recovery facilities means that wherever possible we employ very high quality and field proven automation components,” says Adam Moore, MRF Project Manager with Ken Mills Engineering Ltd. “We've now used power transmission components from Nord Drivesystems for over two years, and are very happy with the performance and reliability.”
Nord helped KME to specify the gearboxes, choosing the sizes to provide a combination of economy and operating safety margins to assure reliability. The underlying performance margin built into the conveying system, and other elements of KME's processing machinery, has been demonstrated many times since the Tilbury plant started operations in October 2007, as the nominal capacity of 25 tonnes/hour is regularly exceeded — sometimes by as much as a third.
Helical bevel gearboxes from Nord's SK9000 family are used on the conveying system. These units provide the ideal right-angle connection to the conveying system. The helical bevel cut teeth provide a smooth, efficient and low noise meshing that is ideal for low speed power transmission applications such as driving conveyors. They increase efficiency substantially compared with the more common style of worm gears used in this kind of application, in this instance providing around 25% greater efficiency, which equates to energy cost savings of many thousands of pounds over a year. Nord's UK facility in Abingdon assembled the gearboxes for KME with ratios to suit the application, and painted the units to provide a ready to connect solution.
Nord Drivesystems, 11 Barton Lane, Abingdon Science Park, Abingdon OX14 3NB, UK. t: +44 (0)1235 534404; f: +44 (0)1235 534414; firstname.lastname@example.org; http://www.nord.com