Eddy current separation of mixed particles employs rotating magnetic fields of variable strength and frequency, spinning and translating ferrous and non-ferrous particles into improved separation trajectories

摘要

Adjustment of field direction induces torque in particles, reinforcing their conveying direction. Magnetic flux density vector (B) direction corresponds with desired particle rotation direction. An Independent claim is included for corresponding equipment carrying out the process. Preferred Features: The particle stream is separated by a magnetic field over a conveyor (1). This induces force and moment in conductive particles; depending on their nature, they are levitated and then fall to the ground through different trajectories. The magnetic wheel (2) of the separator has a conveyor belt (4) running around it, which assists separation and interception (5) of ferromagnetic particles. Particles (8, 9) affected by the field are fractionated in accordance with the lengths of their trajectories, which stem from their properties. Fractionation is varied by adjustable partitioning. The trajectory is varied by: control of pole alternation frequency and/or spacing above the conveyor and/or magnetic field strength. Classification precedes the eddy current separator. This separates side streams, permitting only particles of given size, form or configuration to continue to the eddy current separator. Conveying speed is adjustable.