US4824478A
Expired / Lapsed
US
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Method and apparatus for producing fine metal powder
Assignee: State Street Bank and Trust Co NA
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Filing: 1988-02-29
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Granted: 1989-04-25
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Expires: 2008-02-29
Abstract
Abstract A method and apparatus for producing fine metal powder. The method includes the steps of forming a centrifugally maintained annulus of a liquified gas quench medium, forming molten metal drops within the eye of the annulus, urging the drops into the quench medium to solidify the drops, and boiling away the quench medium to leave behind clean, unentrained metal powder. The apparatus includes a drum for containing a liquified gas quench medium, means for adding liquified gas to the inside of the drum, and means for rotating the drum to form an annulus of quench medium. The apparatus further includes means for forming molten metal to be made into powder, and means disposed along the longitudinal axis of the drum and within the eye of the annulus for creating molten metal drops. The molten metal drops are then urged into the quench medium to solidify them into a powder, and the quench medium is boiled away to leave behind clean, unentrained metal powder.
Inventors
- 👤 Peter R. Roberts
- 👤 James J. Airey
- 👤 James E. Blout
- 👤 Joseph J. Airey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:27
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/02; B22F9/06; B22F9/08; B22F9/10; B22F9/082; B22F2009/086; B22F2999/00
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
56 words
A method for producing fine metal powder comprising the steps of forming a centrifugally maintained annulus of a liquified gas quench medium, forming molten metal drops within the eye of the annulus, urging the drops into the quench medium to solidify the drops, and boiling away the quench medium to leave behind clean, unentrained metal powder.
Claim 2
Independent Claim
56 words
A method for producing fine metal powder comprising the steps of forming a centrifugally maintained annulus of a liquified gas quench medium, forming molten metal drops within the eye of the annulus, urging the drops into the quench medium to solidify the drops, and boiling away the quench medium to leave behind clean, unentrained metal powder.
Claim 3
Dependent Claim
13 words
The method of claim 1 in which liquid argon is the quench medium.
Claim 4
Dependent Claim
13 words
The method of claim 1 in which liquid nitrogen is the quench medium.
Claim 5
Dependent Claim
17 words
The method of claim 1 in which the mllten metal drops are formed from a consumable electrode.
Claim 6
Dependent Claim
16 words
The method of claim 4 in which the consumable electrode is melted to form molten metal.
Claim 7
Dependent Claim
23 words
The method of claim 5 in which the consumable electrode is melted by a plasma torch that supplies an arc to the electrode.
Claim 8
Dependent Claim
19 words
The method of claim 5 in which the drops are urged into the quench medium by rotating the electrode.
Claim 9
Dependent Claim
20 words
The method of claim 1 in which the molten metal drops are formed by breaking up a molten metal stream.
Claim 10
Dependent Claim
21 words
The method of claim 8 in which a rotating member breaks the stream into drops and projects them toward the annulus.
Claim 11
Dependent Claim
25 words
The method of claim 9 in which the rotating member is made from a relatively inert material that does not react with the molten metal.
Claim 12
Dependent Claim
19 words
The method of claim 1 in which the annulus is formed on the inside surface of a rotating drum.
Claim 13
Dependent Claim
26 words
The method of claim 11 in which the drops are urged into the quench medium by a rotating member that flings the drops into the annulus.
Claim 14
Dependent Claim
18 words
The method of claim 12 in which the drum and the rotating member are rotating in opposite directions.
Claim 15
Dependent Claim
16 words
The method of claim 12 in which the drum and the rotating member are independently rotating.
Claim 16
Dependent Claim
16 words
The method of claim 11 in which the drum is rotating at a variable angular velocity.
Claim 17
Dependent Claim
17 words
The method of claim 12 in which the rotating member is rotating at a variable angular velocity.
Claim 18
Dependent Claim
17 words
The method of claim 12 in which the rotating member is rotating at up to 20,000 rpm.
Claim 19
Dependent Claim
24 words
The method of claim 1 in which the quench medium is replenished as it evaporates to maintain an annulus with a substantially constant thickness.
Claim 20
Dependent Claim
24 words
The method claim 1 including the further step of providing an inert gas atmosphere within the eye of the annulus to prevent powder contamination.
Claim 21
Dependent Claim
26 words
The method of claim 1 in which the quench medium is boiled away by maintaining an ambient temperature proximate the boiling point of the liquified gas.
Claim 22
Independent Claim
114 words
A method of producing fine metal powder by quenching molten metal drops into a liquified gas quench medium comprising the steps of: rotating a drum with at least one partially open end at speeds up to 3000 rpm; supplying a liquified gas to the inside of the drum to form an annulus of quench medium within said drum; placing a metallic consumable electrode within the drum and along its longitudinal axis; rotating the electrode; melting the electrode with a plasma torch that supplies an arc to the electrode and forms metal drops that are flung into the quench medium to solidify; and boiling away the quench medium to leave behind clean, unentrained metal powder.
Claim 23
Independent Claim
114 words
A method of producing fine metal powder by quenching molten metal drops into a liquified gas quench medium comprising the steps of: rotating a drum with at least one partially open end at speeds up to 3000 rpm; supplying a liquified gas to the inside of the drum to form an annulus of quench medium within said drum; placing a metallic consumable electrode within the drum and along its longitudinal axis; rotating the electrode; melting the electrode with a plasma torch that supplies an arc to the electrode and forms metal drops that are flung into the quench medium to solidify; and boiling away the quench medium to leave behind clean, unentrained metal powder.
Claim 24
Dependent Claim
26 words
The method of claim 21 including the further step of replenishing the quench medium as it evaporates to maintain an annulus with a substantially constant thickness.
Claim 25
Independent Claim
99 words
An apparatus for producing fine metal powder comprising: a drum for containing a liquified gas quench medium; means for addin9 liquified gas to the inside of said drum; means for rotating said drum to form an annulus of quench medium; means for forming molten metal to be made into powder; means, disposed along the longitudinal axis of said drum and within the eye of the annulus, for forming molten metal drops; means for urging the drops into the quench medium to solidify the drops; and means for boiling away the quench medium to leave behind clean, unentrained metal powder.
Claim 26
Independent Claim
99 words
An apparatus for producing fine metal powder comprising: a drum for containing a liquified gas quench medium; means for addin9 liquified gas to the inside of said drum; means for rotating said drum to form an annulus of quench medium; means for forming molten metal to be made into powder; means, disposed along the longitudinal axis of said drum and within the eye of the annulus, for forming molten metal drops; means for urging the drops into the quench medium to solidify the drops; and means for boiling away the quench medium to leave behind clean, unentrained metal powder.
Claim 27
Dependent Claim
30 words
The apparatus of claim 23 in which said means for boiling away the quench medium includes means for maintaining the ambient temperature proximate the boiling point of the liquified gas.
Claim 28
Dependent Claim
15 words
The apparatus of claim 23 furthr including means for replenishing said medium as it evaporates.
Claim 29
Dependent Claim
14 words
The apparatus of claim 23 further includin9 means for rotating said means for urging.
Claim 30
Dependent Claim
21 words
The apparatus of claim 26 in which said means for rotating turns said means for urging at up to 20,000 rpm.
Claim 31
Dependent Claim
15 words
The apparatus of claim 23 in which said means for forming includes a consumable electrode.
Claim 32
Dependent Claim
18 words
The apparatus of claim 28 in which said means for forming further includes means for melting said electrode.
Claim 33
Dependent Claim
22 words
The apparatus of claim 29 in which said means for melting includes a plasma torch for supplying an arc to said electrode.
Claim 34
Dependent Claim
22 words
The apparatus of claim 23 in which said means for forming includes means for breaking up a molten metal stream into drops.
Claim 35
Dependent Claim
22 words
The apparatus of claim 31 in which said means for breaking includes a rotating member for projecting the drops toward the annulus.
Claim 36
Dependent Claim
25 words
The apparatus of claim 32 in which said rotating member is made of a relatively inert material that does not react with the molten metal.
Claim 37
Dependent Claim
19 words
The apparatus of claim 26 in which the drum and the means for urging are rotating in opposite directions.
Claim 38
Dependent Claim
23 words
The apparatus of claim 23 in which said means for rotating said drum includes means for varying the angular velocity of said drum.
Claim 39
Dependent Claim
27 words
The apparatus of claim 26 in which said means for rotating said means for urging includes means for varying the angular velocity of said means for urging.
Claim 40
Dependent Claim
22 words
The apparatus of claim 25 in which said means for replenishing maintains the annulus of quench medium at a substantially constant thickness.
Claim 41
Dependent Claim
23 words
The apparatus of claim 23 further including means for providing an inert atmosphere within the eye of the annulus to prevent powder contamination.
Claim 42
Dependent Claim
21 words
The apparatus of claim 23 in which said drum has at least one partially open end for speeding liquified gas evaporation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |