Overband Magnet removes metal from wood chips
To protect its biomass plant from costly damage, Western Bio-Energy installed a Bunting EMAX Overband Magnet that removes ferrous contaminants
Western Bio-Energy has found a powerful solution to one of its biggest headaches: tramp metal in woodchip. The U.K.-based biomass power producer recently installed an EMAX Overband Magnet from Bunting Magnetics that is designed to pull both small and large ferrous contaminants from the feedstock before they can cause costly damage.
Removing contaminants from organic material
Western Bio-Energy operates a 15.8 MWh biomass plant that exports electricity to the national grid. Since opening in 2007, the facility has relied on a variety of wood sources, from brash chip and whole tree chip to RCF chip from pallets and other clean recycled wood, as well as virgin wood chip made from tree logs.
But with such diverse inputs comes a familiar problem — metal contamination. Nails, bolts, and fragments can slip into loads, threatening shredders, conveyors, and other equipment.
After an on-site review, Bunting Magnetics supplied a model EMAX140 Electromagnetic Overband Magnet. It now sits inline over the head pulley of a 1.2-metre-wide conveyor, handling an average of 22 tonnes of wood chip per hour.
As wood chip moves beneath it, the overband magnet's powerful magnetic field attracts and lifts metal pieces from the flow. These are carried away on a self-cleaning belt that runs faster than the conveyor, dropping the captured metal into a waste collection area. The inline setup allows the material to break apart as it moves over the head pulley, exposing smaller pieces like screws and nails for easier removal.
Built for longevity, the EMAX Overband Magnet uses a lightweight, armoured belt reinforced with high-density polyethylene slats — 100 millimetres wide and 10 millimetres thick — secured with 304 stainless steel elevator bucket bolts and Nyloc nuts.
Once separated from the conveyed wood chip, ferrous metal falls into a waste collection area, which contains a wide range of small and large tramp metal, including wire, large bolts, flanges, and tools.
This article originally appeared in the November/December issue of Recycling Product News.
