Method and apparatus for evaporating components of multiple substance mixtures and multiple substance systems

A method of evaporating given components from initial multiple-substance mixtures and multiple-substance systems at subatmospheric pressure in a vacuum chamber comprising:

• arranging individual portions of said multiple-substance mixture or multiple-substance system at multiple levels in ring crucibles made of a material which acts as a susceptor in alternating electromagnetic fields;
• placing at least one heat body under the lowermost ring crucible and at least one heat body over the uppermost ring crucible;
• said heat bodies being made of a material which likewise acts as a susceptor in alternating electromagnetic fields;
• heating by inductive coupling through at least one induction coil said ring crucibles and said heat bodies such that said lowermost ring crucible and said uppermost ring crucible are additionally heated by the heat bodies;
• timing the heating of the ring crucibles such that at least one of the given components of the multiple-substance mixture or multiple-substance system is obtained in a purified form;
• and
• drawing off the vapors from the lower boiling component(s) of said individual portions in each case through at least one vapor exhaust opening each, the uppermost ring crucible being closed except for the vapor exhaust opening.