Eddy Current Separators

The Eddy Current Separator (ECS) utilises magnetic forces to physically repel non-ferrous metals and enables separation from non-conductive materials.  The eddy current separator is often supplied as part of a metal separation module with a first-stage drum magnet removing ferrous metals.

To maximise the separation and recovery of non-ferrous metals, Bunting has developed four different eddy current separator models:

• High-Intensity Eccentric (HIE) ECS – for small non-ferrous metals down to 3mm;
• High-Intensity Concentric (HIC) ECS – for small non-ferrous metals down to 10mm;
• R Type ECS – for general recycling applications where non-ferrous metals are above 20mm
• Can Sorter (CS) ECS – A cost-efficient model designed specifically for the recovery of aluminium cans;

Eddy Current Separators commonly form part of a Metal Separation Module as a two-stage metal separator.  Material initially passes over a Permanent Drum Magnet to remove and recover ferrous metals, leaving a non-magnetic fraction.  The Eddy Current Separator then separates non-ferrous metals from the non-conductive remains.

Operation

An eddy current separator is a dual pulley conveyor system, where the non-metallic rotor cover houses an independently rotating high-speed magnetic rotor.  Separation occurs when a non-ferrous metal particle (e.g. aluminium, copper or zinc) is conveyed into the magnetic zone.  The non-ferrous metal particle is exposed to rapidly changing magnetic polarity.  This induces ‘eddy currents’ into the particle generating an electrical current (Fleming’s left-hand rule) that subsequently creates its own magnetic field.  The two magnetic fields oppose each other (i.e. North vs North pole repulsion), causing the repulsion of the non-ferrous metal particle and change in trajectory.  The measured positioning of a splitter enables the separation of non-ferrous metals from non-metallic material due to the altered and unaltered material trajectories.

The speed of the magnetic rotor is dependent on the number of poles on the magnetic rotor and the application.