Eddy current separator
An eddy current separator is a sorting machine used in waste recycling. This device separates non-ferrous metal packaging (e.g. aluminium, zinc, copper) from other packaging materials, including ferromagnetic packaging.
Principle of the eddy current separator
The eddy current theory, which holds that if a conductive mass is exposed to a variable magnetic field, a magnetic field will appear within this mass, is applied to magnetically separate non-ferromagnetic metallic elements.
This is how the separator generates a magnetic field within the non-ferrous metals. The field functions as a repellent, using an opposite magnetic field at the end of the waste conveyor belt. While ordinary waste falls onto a second conveyor belt through basic gravity, aluminium and other non-ferromagnetic metals are lifted and projected forwards towards a third belt.
Thus, the incoming flow of mixed waste is separated into two flows, one of which is of non-ferrous metals.
An eddy current separator is used to clear non-ferrous metals from glass during glass recycling: the glass falls under the grey metal plate while the non-ferrous metals "jump" over it. © G. Macqueron/Futura-Sciences
Eddy current separator - 1 Photo