US3915694A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for desulphurization of molten pig iron
Assignee: JFE Engineering Corp
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Filing: 1973-08-20
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Granted: 1975-10-28
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Expires: 1993-08-20
Abstract
Abstract This invention relates to an improved method for desulphurizing molten pig iron by adding a desulphurizing agent to molten pig iron bath contained in a ladle and agitating said bath with an impeller placed in said bath, wherein downward streams are caused in said bath by inserting one or more guide plates in the upper portion of the bath thereby to draw the desulphurizing agent into the downward streams and an improved rate of desulphurization is obtained even when the rotation speed of said impeller is lower than when no guide plate is employed.
Inventors
- 👤 Ryo Ando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:46
CPC Classifications
F; F27; F27D; F27D27/00; C; C21; C21C; C21C1/00; C21C1/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
103 words
A METHOD OF DESULPHURIZING MOLTEN PIG IRON IN A VESSEL, COMPRISING THE STEPS OF MECHANICALLY STIRRING SAID MOLTEN PIG IRON WITH A ROTATING IMPELLER DISPOSED IN SAID MOLTEN PIG IRON, THE ROTATING IMPELLER HAVING A SHAF WHICH IS SUBSTANTIALLY VERTICALLY DISPOSED IN THE VESSEL, THEREBY CREATING A CIRCULATING UPPER LAYER OF MOLTEN PIG IRON AND A SUBSTANTIALLY STATIC LOWER LAYER OF MOFTON PEG IONS THE UPPER LAYER HAVIN STREAMS FLOWING SUBSTANTIALLY HORIZONTALLY THEREIN, IMMERSING A GUIDE PLATE INTO SAID MOLTEN PIG IRON TO A DEPTH OF BETWEEN ONE-FOURTH AND THREE-FOURTHS OF THE DISTANCE BETWEEN THE SURFACE OF SAID MOLTEN PIG IRON WHEN THE
Claim 2
Independent Claim
103 words
A METHOD OF DESULPHURIZING MOLTEN PIG IRON IN A VESSEL, COMPRISING THE STEPS OF MECHANICALLY STIRRING SAID MOLTEN PIG IRON WITH A ROTATING IMPELLER DISPOSED IN SAID MOLTEN PIG IRON, THE ROTATING IMPELLER HAVING A SHAF WHICH IS SUBSTANTIALLY VERTICALLY DISPOSED IN THE VESSEL, THEREBY CREATING A CIRCULATING UPPER LAYER OF MOLTEN PIG IRON AND A SUBSTANTIALLY STATIC LOWER LAYER OF MOFTON PEG IONS THE UPPER LAYER HAVIN STREAMS FLOWING SUBSTANTIALLY HORIZONTALLY THEREIN, IMMERSING A GUIDE PLATE INTO SAID MOLTEN PIG IRON TO A DEPTH OF BETWEEN ONE-FOURTH AND THREE-FOURTHS OF THE DISTANCE BETWEEN THE SURFACE OF SAID MOLTEN PIG IRON WHEN THE
Claim 3
Dependent Claim
30 words
The method according to claim 1 comprising immersing a guide plate having a width of between one-fourth and two-thirds of the radius of said vessel into said molten pig iron.
Claim 4
Dependent Claim
39 words
The method according to claim 1 comprising mechanically stirring said molten pig iron with a plurality of said rotating impellers, and immersing a plurality of guide plates into said molten pig iron, in at least one of said vessels.
Claim 5
Dependent Claim
33 words
The method according to claim 1 comprising rotating said impeller at a speed approximately 50-80% of the speed required to form a vortex pattern in said molten pig iron without a guide plate.
Claim 6
Dependent Claim
12 words
The method according to claim 1, wherein said vessel is a ladle.
Claim 7
Dependent Claim
22 words
The method according to claim 1, wherein a plurality of vessels are arranged in series for continuous desulfurization of molten pig iron.
Claim 8
Dependent Claim
33 words
The method according to claim 1, wherein said guide plate is positioned in said vessel such that a portion of said guide plate is located directly above the locus described by said impeller.
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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) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |