Efficient waste wood processing solutions
August 11, 2021
For many years, waste timber on construction sites was burned as a cheap method of disposal. For a number of decades, this has been banned and has therefore increased the amount of wood and wood-based products being sent for recycling.
These days, ‘waste’ wood is now a sought-after commodity with the final sorted and shredded material being used either as a biomass fuel, animal bedding or in the manufacture of panel products.
The rising amount of wood entering waste streams has called for recycling companies to look at the way they deal with the product. Multi-national waste management and services provider Veolia are one company investing heavily in this sector to meet the recycling requirements of their customers and have recently opened up a new wood waste facility in Runcorn.
Sitting on the side of the Manchester Ship Canal, the new facility has been designed specifically for the recycling of wood and wood-based products. Despite only having been open a few months, Operations Manager James Ashcroft Explains that the site is already for expansion as the amount of material coming through the plant is increasing on a daily basis.
“We deal with a number of leading manufacturers of timber board products for our material and have to ensure that the blend of material is correct for them.” James explained “There is a desired ratio of chipboard and MDF to raw timber in our final product. Their manufacturing plants can accept just 10% of premanufactured timber within the mix so we have to be selective when it comes to sorting the incoming material.”
Timber is sourced from a number of recycling centres around the greater Merseyside area and is deposited in the bays from a number of 40yd bins on a daily basis. The site is a copy of a similar facility in Coventry and originally the timber was picked through by hand in a mobile picking station. This was a labour intensive and time-consuming job which still required a machine to load the material and sort out some of the larger items. James was quick to revise the plans at Runcorn moving to more mechanical means.
The site currently has planning for 50,000 tonnes per year, a total James is very confident of hitting with almost all of this material being handled by a fleet of new equipment from the Molson catalogue.
Whilst the processing equipment was already ordered from Molson Green, when James decided to alter the incoming sorting method, it was Molson Equipment who were able to step up rapidly and supply a Kobelco SK75SR-7 complete with Kinshofer selector grab. “With four men picking and sorting we were achieving about 1.2 tonnes per hour on a good day.” James explains “With the Kobelco we are easily achieving 1.8 tonnes per hour consistently. We have had the expense of adding the new excavator but have increased both productivity and safety whilst allowing us extra space in the yard and utilising the material handler solely for loading material into the processing chain.” The SK75 has been so impressive that a second machine is on order with a view to increasing the throughput of the plant.
Whilst a pair of Caterpillar 926M waste specification loaders move raw and processed material around the concreted yard, the main production team is sourced from Molson Green range of equipment.
Sitting adjacent to a what seems a never-ending pile on raw material is a new 22t Sennebogen 818 E material handler. Powered by a Cummins B4 Stage 5 compliant diesel engine and equipped with K9ULM boom and dipper, the Sennebogen has a reach of 9m at ground level and a lift height of in excess of 10m which is more than enough to load the Terex Ecotec TDS 820 slow speed shredder. Fitted with a 500l capacity NPK selector grab, the handler is ideally matched to the processing equipment. With a hydraulically elevating cab raising the operator up to a height of almost 6m off the ground the hopper on the shredder is right in their eyeline making it easy to spot any blockages in the shredder chamber.
The processing equipment comes in the shape of a pair of Terex Ecotec shredders. The aforementioned TDS 820 slow speed shredder and a TDS V20 medium speed shredder. The decision to purchase the two different machines was entirely down to the experience from other sites.
The primary processing machine, the TDS 820 handles every piece of incoming timber. Fitted with a German designed shredding chamber consisting of a pair of independently driven shafts each holding 36 cutting elements, the shredder breaks down the wood products before sending them into a Terex Finlay 893 inclined screener. The 893 heavy duty screen is a high-capacity machine, engineered and built for working in the quarrying and mining applications but as Veolia have realised, is more than capable of handling timber waste. The 893 features a forward- facing inclined modular configuration screen box with a 6.1m x 1.83m top deck and a 5.5m x 1.83m bottom deck. Featuring three conveyors, the 893 removes the smaller fines and material up to 80mm, the larger material is then transferred into the medium speed TDS V20. Similar in size to the slow speed machine, the TDS V20 is equipped to produce a consistent and regular sized material ideal for the manufacture of board products. Two shafts housing a total of 96 bolt-on cutting (reversable) teeth break the wood into the desired size against a fixed comb inside the shredding chamber with the resulting material passing out of the shredder chamber through a series of perforated holes in the drum.
Of the estimated 50,000 tonnes the plant will recycle, over 80% will be sent a short distance to one of the largest board manufacturers in the UK where it will be turned into MDF, chipboard and flooring. The remaining 20% or so will be used locally in biomass power stations.
With the increasing demand on recycling companies to produce high quality products, Veolia are ahead of the game with their latest investment at Runcorn. “It has been a large capital investment in developing this plant.” James explains “But we feel we have invested in the right equipment with the right back up to allow us to meet our needs for the local community and offer our clients a quality product that fits their needs.”