Device and method for melting a material without a crucible and for atomizing the melted material in order to produce powder

A device for the crucible-free melting of a material and for atomising the melted material for manufacturing powder, the device comprising:

• a Laval nozzle that defines a nozzle axis;
• an induction coil with windings, which at least in sections become narrower in the direction towards the Laval nozzle;
• and
• a material rod which is introduced at least partly into the induction coil;
• wherein:
• the induction coil is configured to melt the material of the material rod for producing a melt flow;
• the induction coil and the Laval nozzle are arranged in a manner such that the melt flow can be introduced or is introduced into the Laval nozzle through a first opening of the Laval nozzle, for the atomisation of the melt flow by way of an atomisation gas which can be introduced into the Laval nozzle;
• the Laval nozzle is configured such that the atomisation gas can only be introduced or is only introduced into the Laval nozzle through said first opening of the Laval nozzle;
• the Laval nozzle is configured to accelerate the atomisation gas and to create a laminar flow of the atomization gas in a direction parallel to the melt flow, at least up to the speed of sound of the atomisation gas;
• the Laval nozzle and the induction coil are separate components and the induction coil is spaced apart from the Laval nozzle along the nozzle axis;
• the induction coil is disposed such and the Laval nozzle is configured such that quantity amin is less than three times quantity dmin, the quantity amin being a minimum distance between the induction coil and a plane perpendicular to the nozzle axis and defined by a minimal cross-sectional area of the Laval nozzle, the quantity dmin being a smallest inner diameter of the Laval nozzle determined within said plane;
• the Laval nozzle and the induction coil are configured such that a diameter of a contour of the Laval nozzle perpendicular to the nozzle axis from the first opening of the Laval nozzle is between 0.8 times and three times a diameter of the induction coil perpendicular to the nozzle axis at an end of the induction coil which faces the Laval nozzle;
• and
• the material rod, the induction coil, and the Laval nozzle are arranged in a manner such that along the nozzle axis at least a winding of the induction coil facing the Laval nozzle is disposed between the Laval nozzle and an end of the material rod facing the Laval nozzle, so that the melt flow is inductively heatable or heated by the induction coil, before entry of the melt flow into the Laval nozzle.