US4274864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Making iron powder
Assignee: Vodafone GmbH
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Filing: 1979-02-07
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Granted: 1981-06-23
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Expires: 1999-02-07
Abstract
Abstract Iron powder of high compressibility and low bulk density is made by atomizing a stream of molten steel by means of a conical jet of water at a rate in excess of 10 cubic meters water per metric ton of steel, the half cone angle is between 40 DEG and 60 DEG , preferably 45 DEG ; and air suction is provided in a region upstream from the cone, adjacent to the stream at a pressure of 0.02 to 0.20 bars below ambient, by means of a length adjustable tube extending down from the nozzle chamber. The powder is reduced at 1,000 DEG C. to 1,200 DEG C., and the resulting cake is broken up to obtain a powder having a particle size distribution with a higher content of larger particles than the powder immediately resulting from the atomization.
Inventors
- 👤 Dieter Bernhardt
- 👤 Norbert Dautzenberg
- 👤 Richard Lummer
- 👤 Georg Huber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:37
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/02; B22F9/06; B22F9/08; B22F9/082
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
153 words
Method of making an iron powder of high compressibility and low bulk density by means of atomizing a stream of molten steel, comprising the steps of: providing a conical jet of water at a water pressure prior to jet formation in excess of 80 bars and at a rate in excess of 10 cubic meters water per metric ton of steel, the cone of the jet having an angle so that the water impinges upon the stream at an angle between 40° and 60°; providing air suction in a region upstream from the cone, adjacent to the stream at a pressure of 0.02 to 0.20 bars below ambient; annealing the powder in a reducing atmosphere at a temperature from 1,000° C. to 1,200° C.; and breaking a resulting cake to obtain a powder having a particle size distribution with a higher content of larger particles than the powder immediately resulting from the atomization.
Claim 2
Dependent Claim
153 words
Method of making an iron powder of high compressibility and low bulk density by means of atomizing a stream of molten steel, comprising the steps of: providing a conical jet of water at a water pressure prior to jet formation in excess of 80 bars and at a rate in excess of 10 cubic meters water per metric ton of steel, the cone of the jet having an angle so that the water impinges upon the stream at an angle between 40° and 60°; providing air suction in a region upstream from the cone, adjacent to the stream at a pressure of 0.02 to 0.20 bars below ambient; annealing the powder in a reducing atmosphere at a temperature from 1,000° C. to 1,200° C.; and breaking a resulting cake to obtain a powder having a particle size distribution with a higher content of larger particles than the powder immediately resulting from the atomization.
Claim 3
Dependent Claim
9 words
Method as in claim 1 said angle being 45°.
Claim 4
Dependent Claim
13 words
Method as in claim 1 or 2 said reducing temperature being 1,100° C.
Claim 5
Dependent Claim
46 words
Method as in claim 1 the breaking of the cake being carried out to obtain a powder having a particle size distribution as follows: ______________________________________
+300 μm 0%
+200 μm 5%
+160 μm 20%
+100 μm 30%
+ 63 μm 25%
- 63 μm 20%
______________________________________
Claim 6
Dependent Claim
28 words
The method as in claim 1, wherein the step of providing air suction includes the step of running the stream through a tube, establishing an air suction path.
Claim 7
Dependent Claim
17 words
The method as in claim 5 and including the step of varying the length of the tube.
References Cited (Backward Citations)
GB572148A
Cited
US3325277A
Cited
US3668024A
Cited
US3752712A
Cited
US3909239A
Cited
US3900309A
Cited
US3954461A
Cited
US4124377A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-22 | 1984-12-22 | 1985-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-22 | 1988-12-22 | 1989-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-22 | 1992-12-22 | 1993-06-23 | $7700.00 | Window Closed / Lapsed |