Claims
- 1. A method of producing metal particulate including the steps of:
- (1) forming a continuous annular flow of gaseous cooling fluid, said annular flow of gaseous cooling fluid being made up of a plurality of annular adjacent flow sections of gaseous cooling fluid at different annular locations with each having a mass flow;
- (2) melting metal to form a supply of molten metal;
- (3) projecting the molten metal outwardly from within said annular flow of said gaseous cooling fluid as liquid droplets into said annular flow of gaseous cooling fluid solidifying said liquid droplets into metal particles, each projected liquid droplet and resulting metal particle having a cooling rate as it passes through each annular adjacent flow section of gaseous cooling fluid;
- (4) individually controlling the mass flow of each of a plurality of said individual annular adjacent flow sections of gaseous cooling fluid so that the annular flow has a plurality of its individual annular flow sections each with a selected mass flow to control the cooling rate of each projected liquid droplet and resulting solidified metal particle at different annular locations as it passes through the annular flow of gaseous cooling fluid; and
- (5) collecting said solidified metal particles.
- 2. A method of producing metal particulate as set forth in claim 1 wherein step (3) said molten metal is projected by being centrifugally flung as droplets in a generally horizontal direction to intersect the annular adjacent flow sections of gaseous cooling fluid.
- 3. A method of producing metal particulate as set forth in claim 1 wherein step (2) said molten metal is introduced into a container rotating about a vertical central axis, and in step (3) said molten metal is projected by being centrifugally flung from said container as droplets in a generally horizontal direction to intersect the annular adjacent flow sections of gaseous cooling fluid.
- 4. A method as set forth in claim 1 wherein the gaseous cooling fluid is a high thermal conductivity gas to obtain a desired cooling rate of the particles in excess of 10.sup.5 .degree. C./sec for particles in the range of 10 microns to 50 microns in diameter.
- 5. A method as set forth in claim 1 wherein step (1) said continuous annular flow of gaseous cooling fluid is formed in a first enclosed area containing the gaseous cooling fluid; wherein step (2) said metal is melted in a second enclosed area containing an inert gas.
- 6. A method as set forth in claim 5 including the steps of placing the first enclosed area under pressure, placing the second enclosed area under pressure, controlling the pressure differential between the first enclosed area and the second enclosed area to obtain a desired molten metal flow from said second enclosed area to said first enclosed area.
- 7. A method as set forth in claim 1 wherein step (1) one or more of said plurality of annular adjacent flow sections is formed by a gaseous cooling fluid which is chemically reactive with the particles being formed placing a desired chemical composition on the surface of the particles.
- 8. A method as set forth in claim 1 wherein the mass flow rate of said plurality of said annular adjacent flow sections of gaseous cooling fluid are each controlled to maintain the maximum possible temperature difference between the droplets and particles and the gaseous cooling fluid at all radial locations consistent with the gaseous cooling fluid available.
- 9. A method as set forth in claim 1 wherein step (1) said continuous annular flow of gaseous cooling fluid is made up of three or more annular adjacent flow sections of gaseous cooling fluid to provide a large varied control of the cooling rate of each projected liquid droplet and resulting metal particle for a radius of travel as it passes through said continuous annular flow of gaseous cooling fluid.
- 10. A method as set forth in claim 1 wherein step (5) said solidified metal particulate are collected and removably contained in the gaseous cooling fluid for transportation as collected to another location.
Parent Case Info
This application is a Continuation of Application Ser. No. 853,077, filed Nov. 21, 1977, now abandoned which is a Continuation of Application Ser. No. 654,247, filed Jan. 30, 1976 now abandoned.
U.S. Pat. No. 4,078,873 issued from a Division of Application Ser. No. 654,247, filed Jan. 30, 1976.
US Referenced Citations (3)
Continuations (2)
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Number |
Date |
Country |
Parent |
853077 |
Nov 1977 |
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Parent |
654247 |
Jan 1976 |
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