ElectroMax-Plus overband magnet EMAX 120 over a 1.2m wide conveyor

General skip waste recycler W. Maw Recycling Ltd has installed two Bunting ElectroMax-Plus overband magnets at its Rotherham operation. The powerful electromagnetic overband magnet replaced permanent overband magnets to separate larger and heavier ferrous metal that could damage shredders and other process plant.

Bunting is one of the world’s leading designers and manufacturers of magnetic separators, eddy current separators, metal detectors and electrostatic separators. The Bunting European manufacturing facilities are in Redditch and Berkhamsted.

W. Maw Recycling has more than 17 years’ experience in providing domestic and commercial skip hire. The company’s fully licensed waste transfer station in Rotherham is open to domestic and commercial visitors who hold a current waste carriers’ licence.

W. Maw were using two permanent overband magnets to recover ferrous metal from waste at the transfer station. However, the difficult nature of the waste and the presence of larger and heavier ferrous metal, such as hammer heads and disc brakes, meant the separation performance failed to meet requirements. The inability to separate the larger and heavier ferrous metal was resulting in costly and time-consuming damage to shredders and other process plant.

Pictured right: metal missed by other overband magnets but captured by the ElectroMax-Plus

Bunting’s technical sales engineer, Tom Higginbottom, visited site to review the installation. The challenging application led to the selection of two ElectroMax-Plus overband magnets.

The ElectroMax and ElectroMax-Plus range of electromagnetic overband magnets is up to 185% stronger than equivalent permanent overband magnets and 25% lighter. The lightweight but powerful design is ideally suited for applications where space is limited or when extra separation power is required.

The two ElectroMax-Plus overband magnets operate with a self-cleaning belt, which rotates around the magnet to transfer and automatically discharge the ferrous metal that has been attracted up and onto the face of the electromagnet. The ElectroMax-Plus uses a simple frame with the cleaning belt driven and guided by two pulleys instead of four (as used for larger standard electro overband magnets). This significantly reduces the overall weight and size. In addition, unlike other designs of Electro overband and suspension magnets, the coil of the ElectroMax-Plus overband magnet is cooled by air, eliminating the need for any conservator tanks.

The two ElectroMax-Plus overband magnets are installed on different waste processing lines at the Rotherham plant. The ElectroMax-Plus 120 is positioned across a 1.2m-wide conveyor with the second ElectroMax-Plus 140 over a slightly wider conveyor with a 1.4m-wide belt. Both are suspended at 400mm above the surface of the conveyor.

Due to the arduous nature of the application, both ElectroMax overband magnets are fitted with armoured belts. These reinforced belts protect the surface of the cleaning belt from piercing and excessive wear.

Pictured left: ElectroMax-Plus overband magnet EMAX 140 over a 1.4m-wide conveyor

The installation of electro rather than permanent overband magnets brought an added advantage. During maintenance of the overband magnets or other parts of the plant, the magnets can be turned off. This improved safety, while decreasing the difficulty and time needed to undertake basic maintenance on the overband magnets such as changing belts or replacing motors. The ferrous metal recovered by the ElectroMax-Plus overband magnets is sent for further processing and cleaning at a local fragmentiser.

Tony Scarlet W. Maw’s managing director, concluded: “Since the installation of the ElectroMax-Plus overband magnets we are no longer experiencing significant damage to our shredders. The magnets are pulling out really heavy and awkward ferrous metal, that the permanent magnets could not touch. They are doing a great job.”