Atomizer for improved ultra-fine powder production

Patent metadata

Field	Value
Publication number	US-10835959-B2
Application number	US-201815932837-A
Country	US
Kind code	B2
Filing date	May 2, 2018
Priority date	Sep 24, 2013
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A concentric ring gas atomization nozzle with isolated gas supply manifolds is provided for manipulating the close-coupled atomization gas structure to improve the yield of atomized powders.

First claim

We claim:

1. A method of gas atomizing a melt to produce atomized powder, comprising discharging a melt from a melt discharge orifice of a melt supply tube, atomizing the melt by discharging atomizing gas jets toward the melt discharge orifice from a first annular array of a plurality of first discrete gas jet orifices disposed about the periphery of the melt supply tube and supplied from a first gas supply manifold and by discharging atomizing gas jets from a second annular array of a plurality of second discrete gas jet orifices arranged outwardly of the first annular array and supplied from a second gas supply manifold that is isolated from the first gas supply manifold, including the isolated first gas supply manifold and the second gas supply manifold independently supplying atomizing gas to the first annular array and second annular array in a manner to control an atomizing gas flow structure to have a gas recirculation zone immediately below the melt discharge orifice.

2. The method of claim 1 wherein the gas flow structure has a truncated recirculation zone shape.

3. The method of claim 1 wherein a first gas jet pressure of the first gas supply manifold and a second gas jet pressure of the second gas supply manifold are isolated and are different to provide the recirculation zone.

4. The method of claim 1 wherein a first gas jet composition of the first gas supply manifold and a second gas jet composition of the second gas supply manifold are isolated and are different.

5. The method of claim 1 wherein a first gas jet composition of the first gas supply manifold and a second gas jet composition of the second gas supply manifold are isolated and are the same.

6. The method of claim 1 wherein atomizing of the melt produces atomized precursor oxide dispersion strengthened stainless steel powder.

7. The method of claim 6 wherein atomized precursor oxide dispersion strengthened ferritic stainless steel powder is produced.

8. A method of gas atomizing a melt to produce atomized powder with a size yield of a majority of the powder being about 20 to about 75 μm in diameter, comprising discharging a melt from a melt discharge orifice of a melt supply tube, atomizing the melt by discharging atomizing gas jets toward the melt discharge orifice from a first annular array of a plurality of first discrete gas jet orifices disposed about the periphery of the melt supply tube and supplied from a first gas supply manifold and by discharging atomizing gas jets from a second annular array of a plurality of second discrete gas jet orifices arranged outwardly and downstream of the first annular array and supplied from a second gas supply manifold that is isolated from the first gas supply manifold, including the isolated first gas supply manifold and the second gas supply manifold independently supplying atomizing gas to the first annular array and second annular array in a manner to control an atomizing gas flow structure to have a gas recirculation zone immediately below the melt discharge orifice.

9. The method of claim 8 wherein the gas flow structure has a truncated recirculation zone.

10. The method of claim 8 wherein a first gas jet pressure of the first gas supply manifold and a second gas jet pressure of the second gas supply manifold are isolated and are different to provide the recirculation zone of the gas structure.

11. The method of claim 8 wherein the first supply manifold and the second supply manifold supply the same atomizing gas.

12. The method of claim 8 that provides an open wake or closed wake atomizing gas structure.

Assignees

• Univ Iowa State Res Found Inc

Inventors

• Rieken Joel R
• Heidloff Andrew J
• Anderson Iver E

Classifications

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• C22C38/06

  containing aluminium · CPC title

• B22F2009/0892

  casting nozzle; controlling metal stream in or after the casting nozzle · CPC title

• B22F9/082 Primary

  atomising using a fluid (using centrifugal force B22F9/10) · CPC title

• C22C38/002

  containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60 · CPC title