Analysis of the main working principle of eddy current sorter
March 6, 2023
Speaking of eddy current sorter, we may not know very well, but eddy current sorter has also brought great help to our life. Those familiar with it should know that eddy current sorter is a separation technology that uses different conductivity of materials. Its separation principle is based on two important physical phenomena: an alternating magnetic field that changes with time is always accompanied by an alternating electric field (electromagnetic induction law); Magnetic field generated by current-carrying conductor (Biot-Savart law).
The magnetic cylinder inlaid with its magnet rotates at high speed, producing an alternating magnetic field. When the metal with conductive property passes through the magnetic field, eddy current will be generated in the metal. The eddy current itself produces an alternating magnetic field, which is opposite to the magnetic field produced by the magnetic cylinder, that is, it produces a repulsive force (Lorentz force) on the metal to separate the metal from the material flow and achieve the purpose of separation.
In addition, the repulsive force generated by eddy current on the conductor is related to the intensity of magnetic field change, conductivity, density, area and shape of the conductor. For different nonferrous metal materials, the repulsive force is related to the composition characteristics.