Method and device for producing powders that consist of substantially spherical particles
AssigneeApplikations-und Technikzentrum für Energieverfahrens-Umwelt-, und Strömungstechnik (ATZ-EVUS)
InventorsGerhard Wolf, Andreas Emmel
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Abstract
A method for producing powders that consist of substantially spherical particles from a material such as glass, ceramics or plastic that produces a highly viscous melt that solidifies at a glass transition temperature Tg or at a solidification temperature Ts. The inventive method comprises the following steps: (a) producing a melt of a viscosity η in the range of from 0.1 to 100 Ns/m2; (b) atomizing the melt using a first gas, the first gas having a temperature TA≧Tg or ≧0.5Ts at the outlet of the nozzle and (c) cooling off the particles produced by atomization in a cooling section downstream of the nozzle using a coolant, the temperature of the coolant being smaller than Ts or Tg.
Claims20
A process for producing powders, which are formed from substantially spherical particles, from a material, such as glass, ceramic or plastic, which forms a highly viscous melt, which solidifies either at a glass forming temperature Tg or at a setting temperature Ts, said method comprising the steps of:
- a) producing a melt with a dynamic viscosity η in the range between 0.01 and 100 Ns/m2,
- b) atomizing the melt using a first gas, the first gas, at an outlet of an annular gap of an annular nozzle, being at least at a temperature TA≧Tg or ≧0.5 Ts and an angle of incidence of the first gas with respect to a molten-jet axis being up to 25°,
- c) cooling particles formed during the atomizing step in a cooling zone, which is connected downstream of the annular nozzle, using a coolant, the coolant being at a temperature <Tg or Ts.
Dependencies are inferred from the claim text.