Abstract: A device for obtaining multicrystalline silicon, including: at least one crucible made of quartz for the silicon, removably housed in a cup-shaped graphite container; a fluid-tight openable casing; a top induction coil, set facing, with interposition of a graphite plate, the crucible, a lateral induction coil, set around a side wall of the graphite container, and a bottom induction coil, set facing a bottom wall of the graphite container and vertically mobile for varying the distance from the bottom wall; and first means for a.c. electrical supply of the induction coils separately from one another, and second means for supply of a coolant within respective hollow turns of the induction coils; the bottom induction coil includes four spiral windings, arranged alongside one another; electrical switching means enable in use selective connection of the four windings to one another according to different configurations.

Abstract: A device for obtaining multicrystalline silicon, including: at least one crucible, removably housed in a cup-shaped graphite container; a fluid-tight casing, including a fixed bottom half-shell and a vertically mobile top half-shell; a top induction coil, set facing, with interposition of a graphite plate, the crucible, a lateral induction coil and a bottom induction coil vertically mobile for varying the distance from the bottom wall; and means for a.c. electrical supply of the induction coils separately from one another; at least the lateral induction coil includes a plurality of plane turns set on top of one another, and means for selectively short-circuiting, supplying or not supplying the turns, all together or separately one or more at a time and for varying the frequency of supply thereof all together or separately one or more at a time.