Leading Biomass Supplier reaps rewards of Superior Product Quality and Lower Operational and Maintenance Costs by incorporating an EDGE Slayer XL.

McKinstry Skip Hire Ltd, a family owned and operated company with over seventy years’ experience providing excellence in waste management services to both public and private sector customers throughout Northern Ireland have seen real operational benefits when they opted to incorporate an EDGE Slow speed shredder into their biomass production process.

The company founded in 1970 by Mr Albert McKinstry, is currently managed by his sons Darren and Mark McKinstry, has grown to now employ an eighty strong workforce at their state of the art Material Recovery Facility (MRF) in Northern Ireland, just a few miles from the Belfast International Airport. In 2016 McKinstry Skip hire will supply over 50,000 tonnes of P63 grade woodchip to help power the largest renewable energy project in Northern Ireland. Lisahally Combined Heat and Power Station operated by Evermore Renewable Energy is based in County Derry and generates an impressive 15.8 MWe, the equivalent of enough energy to power 25,000 homes.

THE OLD PROCESS
McKinstry’s Skip Hire extract wood mainly from council operated sites around Northern Ireland along with an additional source from Southern Ireland to ensure material supply in periods of any downtime in the industry. Supplying 1,000 tonnes per week minimum to Lisahally Power Station to a P63 grade, the wood waste when it arrives to the Crumlin site undergoes a quick manual pick through to remove as much contaminates as possible. The high grab then puts the wood waste into a high speed shredder. The shredded product goes through a series of overband magnets, twin deck horizontal screeners and eddy currents to remove ferrous and non-ferrous metals, dust and oversize product.

THE NEW PROCESS
In an effort to improve operational efficiency, reduce running costs and improve product quality, McKinstrys Skip Hire turned to the EDGE manufactured slow speed shredder, the Slayer XL. The new production process sees material go from trailer to the EDGE pre-shredder with minimal pre-sorting to create a uniform piece size product and to remove any non-shreddable contaminants. The material is then feed into a high speed secondary shredder with the finer material passing the series of separation stages.

BENEFITS OF PRE-SHREDDING WITH A SLOW SPEED SHREDDER
With its robust design and massive 80,000Nm of torque combined with intelligent self-protecting operating system, the EDGE Slayer XL provides enhanced protection to their high speed shredder when deploying it as a pre-shredder in front of the high-speed shredder. McKinstrys have found that the EDGE Slayer XL’s ability to withstand non-shreddables such a steel bracketry etc. with minimal wear makes the Slayer XL the ideal partner to their high speed grinder by vastly reducing the wear and tear of the high speed shredder tools and cutting down significant downtime associated to non-shreddables reaching the high-speed shredder chamber.

With the non-shreddable products being removed either by the EDGE shredder’s chamber detection system or via its overband magnet, McKinstry’s operators have found higher percentage uptime and improved dependable performance from their secondary shredder. A constant flow of uniformed piece size material provided by the EDGE Slayer has also allowed the high speed grinder to process material much easier; again improving the lifespan of shredder tools and reducing the levels of fuel consumed being recorded.

SUPERIOR PRODUCT AND ENHANCE OPERATIONAL EFFICIENCY
Helping to reduce fuel and maintenance costs associated with their high speed grinder is only half the story of the improvements the EDGE Slow speed shredder has brought to the table. Howard Wilson, McKinstry’s Biomass Quality Control Manager explains that the end product is superior to that of material that is simple passed through a high speed grinder. By adding a pre-shred and secondary shred to the production process McKinstry’s Biomass Quality Control Manager has found via a particle size analysis of mandatory samples taken twice a day to contain a “…significant reduction in oversize particles, samples have fallen well within the 10% limit and the dust level is well under 2%”.

The low level of dust creation can be accredited to a control feed of near size material entering he high speed grinder, with surges of material being eliminated and by the fact that the EDGE Slayer XL has been engineered to run at a lower rotor RPM combined with high torque. It this feature that helps the EDGE manufactured slow speed shredder to produce a final material product with much lower dust percentage. Howard has also seen an improvement in the production efficiency by incorporating the primary shred into the production process. “We have benefit by a large reduction in oversize, which means we have less to re-shred again, by falling within the 10% ratio, there is only a minimum amount of additional shredding on the oversize that saves us man hours, fuel and it saves us maintenance costs on the machinery.”

With tight restriction placed on suppliers of biomass; reliability, quality and sustainability of material supply are always major concerns. By incorporating the EDGE Slayer XL slow speed shredder; biomass producers can be assured of improved operation efficiency, higher quality end product with reduce dust and oversize creation combine with a reduction in downtime and maintenance.