US4382903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing a metal powder by granulation of a metal melt
Assignee: ABB Norden Holding AB
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Filing: 1981-02-23
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Granted: 1983-05-10
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Expires: 2001-02-23
Abstract
Abstract A method for granulating a metal melt wherein a tap stream of molten metal is granulated by directing a jet of gas having a trough-shaped cross-section against the side of the tap stream such that the tap stream is formed into droplets which are thrown into a parabolic trajectory. An additional gas jet is also directed towards the tap stream so that it hits both the trough-shaped gas jet and the tap stream, the additional gas jet acting to prevent the droplets of metal melt from moving towards the nozzle from which the trough-shaped jet of gas emanates. The nozzle which emits the trough-shaped jet of gas can thus be positioned very closely to the side of the tap stream without becoming clogged with deposited droplets of metal melt.
Inventors
- 👤 Hans G. Larsson
- 👤 Erik Westman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:30
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/02; B22F9/06; B22F9/08; B22F9/082; B22F2009/088
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
158 words
A method of forming a metal powder which includes (a) forming a vertically downwardly moving tap stream of molten metal, (b) directing a trough-shaped first jet of gas towards the side of said stream so as to impact therewith and generate droplets of molten metal and thereafter cause the droplets to be thrown in a substantially parabolic trajectory, said trough-shaped jet of gas having an open top and a vertically oriented plane of symmetry therethrough, said plane of symmetry of said trough-shaped jet intersecting said stream, (c) directing a second jet of gas obliquely downwardly towards the open top of said trough-shaped first jet of gas so as to prevent molten metal droplets from moving in a second jet of gas having the same general direction of flow as said trough-shaped first jet of gas, and (d) rapidly cooling the droplets of molten metal to form the metal powder as said droplets travel in said substantially parabolic trajectory.
Claim 2
Independent Claim
158 words
A method of forming a metal powder which includes (a) forming a vertically downwardly moving tap stream of molten metal, (b) directing a trough-shaped first jet of gas towards the side of said stream so as to impact therewith and generate droplets of molten metal and thereafter cause the droplets to be thrown in a substantially parabolic trajectory, said trough-shaped jet of gas having an open top and a vertically oriented plane of symmetry therethrough, said plane of symmetry of said trough-shaped jet intersecting said stream, (c) directing a second jet of gas obliquely downwardly towards the open top of said trough-shaped first jet of gas so as to prevent molten metal droplets from moving in a second jet of gas having the same general direction of flow as said trough-shaped first jet of gas, and (d) rapidly cooling the droplets of molten metal to form the metal powder as said droplets travel in said substantially parabolic trajectory.
Claim 3
Dependent Claim
46 words
A method according to claim 1 wherein said trough-shaped first jet of gas is directed such that the angle (α) between the direction of flow of said trough-shaped first jet of gas and the direction of flow of the tap stream is between 45° and 135°.
Claim 4
Dependent Claim
15 words
A method according to claim 2 wherein said angle (α) is between 60° and 100°.
Claim 5
Dependent Claim
13 words
A method according to claim 3 wherein said angle of (α) is 90°.
Claim 6
Dependent Claim
43 words
A method according to claim 2 wherein the downwardly moving tap stream has a vertical center line therethrough, and wherein said vertical plane of symmetry of said trough-shaped first jet of gas is aligned with the vertical center line of said tap stream.
Claim 7
Dependent Claim
37 words
A method according to claim 5 wherein said second gas jet is directed so that it impinges the tap stream ahead of the point of impact of the bottom portion of the trough-shaped first jet of gas.
Claim 8
Dependent Claim
33 words
A method according to claim 2 wherein said second gas jet is directed substantially towards the location where the bottom portion of the trough-shaped first jet of gas impinges against said tap stream.
Claim 9
Dependent Claim
37 words
A method according to claim 2 wherein the flow rates of said trough-shaped first jet of gas and said second gas jet are varied so as to adjust the parabolic trajectory of the droplets of molten metal.
Claim 10
Dependent Claim
43 words
A method according to claim 8 wherein said trough-shaped first jet of gas and said second jet of gas flow through respective nozzles and wherein said flow rates thereof are varied by controlling the pressure of the gases fed to the respective nozzles.
Claim 11
Dependent Claim
54 words
A method according to claim 1 including the steps of collecting the gas from the jets, then cooling, cleaning and compressing a first portion of the collected gas and supplying said first portion of collected gas to the nozzles, and cooling and circulating a second portion of the collected gas for removal of heat.
Claim 12
Dependent Claim
17 words
A method according to claim 1 wherein said trough-shaped first jet of gas has a V-shaped cross-section.
Claim 13
Dependent Claim
45 words
A method according to claim 1 wherein two second jets of gas are directed obliquely downwardly towards the open top of said trough-shaped jet of gas, said two second jets of gas having substantially the same direction of flow as said trough-shaped jet of gas.
Claim 14
Dependent Claim
27 words
A method according to claim 1 wherein in step (d) the droplets of molten metal are rapidly cooled by a contact with a stream of cooling gas.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-09 | 1986-11-08 | 1987-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-09 | 1990-11-08 | 1991-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-09 | 1994-11-08 | 1995-05-10 | $7700.00 | Window Closed / Lapsed |