Electromagnetic control of liquid metal free surfaces

摘要

The use of electromagnetic forces is a wonderful tool to act on electroconducting materials without material contact. Specially, this is true for controlling the behavior of free surfaces of liquid metal domain regarding their shape, stability or possible mass transfer though those interfaces. The effects of magnetic field, according to both the intensity and the frequency of the field, will be reviewed. First, the case of a Dc magnetic field is presented. Although this kind of field is generally known to be stabilizing, its application in a steel slab caster can generate strong amplitude and low frequency oscillations. Secondly, aspects related to alternating mono-frequency magnetic fields are presented: total or partial electromagnetic levitation, promotion of oscillations of dome and instabilities, emulsification... Then, the effects of a magnetic field presenting several frequencies are exploited to promote mass transfer to clean up pollutant from a liquid salt to a metallic matrix.