Device and method for producing metal powder using an induction coil and an intermediate coil

A device for producing metal powder, wherein the device comprises:

• a melting chamber;
• an atomization tower disposed downstream of the melting chamber;
• a nozzle assembly for atomizing a melt jet, via which the melting chamber is connected to the atomization tower;
• an induction coil arranged within the melting chamber and operable at a melting frequency fmelt, which is configured to locally melt a material rod received at least section-wise therein in order to produce the melt jet to be atomized,
• a separate intermediate coil arranged within the melting chamber and operable at a base frequency fbase and arranged downstream of the induction coil and aligned coaxially with the induction coil, wherein the intermediate coil is configured to superheat the melt jet in a region between the induction coil and the nozzle assembly,
• wherein the intermediate coil is configured such that a modulation frequency fmod is modulated onto the base frequency fbase at which the intermediate coil is operable,
• wherein a frequency ratio FBS of the base frequency fbase and the melting frequency fmelt is settable to:
• 1≤FBS=fbase/fmelt≤500,
• wherein the nozzle assembly comprises a Laval nozzle,
• wherein the nozzle assembly comprises an annular nozzle,
• wherein the Laval nozzle is configured and arranged in such a way that the melt jet passes through the Laval nozzle from the melting chamber into the atomization tower and an additive gas flows through the Laval nozzle from the melting chamber into the atomization tower, wherein the additive gas accelerates the melt jet as it passes through the Laval nozzle, and
• wherein the annular nozzle is arranged downstream of the Laval nozzle and/or in the region of the Laval nozzle in such a way that an additional atomizing gas flows through the annular nozzle from an atomizing gas source into the atomization tower, as a result of which a locally reduced counterpressure can be generated in a region of an outlet opening of the Laval nozzle adjacent to the atomization tower, so that the following applies to a pressure ratio D between a pre-pressure P0 of the melting chamber and the locally reduced counterpressure P2:
• D=P0/P2≥2.