Patent US6067382A successfully refreshed from Google Patents.
US4667939A
Expired / Lapsed
US
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Purifying steel
Assignee: Foseco International Ltd
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Filing: 1986-03-26
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Granted: 1987-05-26
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Expires: 2006-03-26
Abstract
Abstract A method of purifying steel in a tundish, especially to remove alumina inclusions, comprises passing the steel through at least one refractory board having apertures through it and introducing inert gas into the steel at the upstream side of the foot of the board to cause a stream of bubbles to flow over the upstream side of the board. One of the boards may comprise a ceramic filter element. The boards may be non-vertical and have integral gas supply means. The apertures may taper, may have axes angled from perpendicular to the board's plane and may have high alumina content surfaces. The upstream side of the board may have an exothermic layer.
Inventors
- 👤 Leon A. Luyckx
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:14
CPC Classifications
B; B22; B22D; B22D11/00; B22D11/10; C; C22; C22B; C22B9/00; C22B9/05; C22B9/055; B22D11/11; B22D11/116; B22D11/119; C21; C21C; C21C7/00; C21C7/0006
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
59 words
A board of refractory material, to be positioned generally upright in a tundish across the tundish, having a plurality of apertures through it through which steel can pass and, at the lower part of one face, a gas-permeable portion through which gas can pass outwardly and ducting for the supply of gas to the back of the gas-permeable portion.
Claim 2
Dependent Claim
59 words
A board of refractory material, to be positioned generally upright in a tundish across the tundish, having a plurality of apertures through it through which steel can pass and, at the lower part of one face, a gas-permeable portion through which gas can pass outwardly and ducting for the supply of gas to the back of the gas-permeable portion.
Claim 3
Dependent Claim
30 words
A board according to claim 1 in which the gas-permeable portion is of refractory material of low gas-permeability having at least on opening in it through which gas can pass.
Claim 4
Dependent Claim
18 words
A board according to claim 1 in which the gas-permeable portion is of refractory material of high gas-permeability.
Claim 5
Dependent Claim
46 words
A board according to claim 1 in which the ducting comprises a pipe embedded in the board, and with an access point at the top, and having at the lower part of the board at least one opening open to the back of the gas-permeable portion.
Claim 6
Dependent Claim
39 words
A board of refractory material, to be positioned generally upright in a tundish across the tundish, having aplurality of apertures through it through which steel can pass, the apertures tapering from one side of the board to the other.
Claim 7
Dependent Claim
39 words
A board of refractory material, to be positioned generally upright in a tundish across the tundish, having aplurality of apertures through it through which steel can pass, the apertures tapering from one side of the board to the other.
Claim 8
Dependent Claim
44 words
A board of refractory material, to be positioned generally upright in a tundish across the tundish, having a plurality of apertures through it through which steel can pass, the axes of the apertures being at a non-perpendicular angle to the plane of the board.
Claim 9
Dependent Claim
44 words
A board of refractory material, to be positioned generally upright in a tundish across the tundish, having a plurality of apertures through it through which steel can pass, the axes of the apertures being at a non-perpendicular angle to the plane of the board.
Claim 10
Dependent Claim
27 words
A board according to claim 6 in which the axes of the apertures deviate by from 5° to 30° from perpendicular to the plane of the board.
Claim 11
Dependent Claim
39 words
A board of refractory material, to be positioned generally upright in a tundish across the tundish, having a plurality of apertures through it through which steel can pass, the walls defining the apertures comprising a high alumina content material.
Claim 12
Dependent Claim
39 words
A board of refractory material, to be positioned generally upright in a tundish across the tundish, having a plurality of apertures through it through which steel can pass, the walls defining the apertures comprising a high alumina content material.
Claim 13
Dependent Claim
16 words
A board as recited in claim 2 wherein said at least one opening comprises a slot.
Claim 14
Dependent Claim
18 words
A board as recited in claim 2 wherein said at least one opening comprises a plurality of holes.
Claim 15
Dependent Claim
21 words
A board as recited in claim 8 wherein the walls defining the apertures have a coating of high alumina content material.
Claim 16
Dependent Claim
21 words
A board as recited in claim 8 wherein the walls defining the apertures have sleeve-like inserts of high alumina content material.
Claim 17
Dependent Claim
67 words
A tundish for use in the teeming of molten metals having a generally horizontally extending base, and a width; and a board of refractory material positioned generally upright in the tundish, across the width of the tundish, said board having a plurality of apertures through it through which steel can pass, the axes of the apertures beign at a non-perpendicular angle to the plane of the board.
Claim 18
Dependent Claim
67 words
A tundish for use in the teeming of molten metals having a generally horizontally extending base, and a width; and a board of refractory material positioned generally upright in the tundish, across the width of the tundish, said board having a plurality of apertures through it through which steel can pass, the axes of the apertures beign at a non-perpendicular angle to the plane of the board.
Claim 19
Dependent Claim
25 words
A board according to claim 13 in which the axes of the apertures deviate by from 5°-30° from perpendicular to the plane of the board.
Claim 20
Dependent Claim
17 words
Apparatus as recited in claim 13 further comprising walls defining the apertures having a high alumina content.
Claim 21
Dependent Claim
27 words
Apparatus as recited in claim 13 wherein the board is slightly inclined with respect to the vertical, disposed at an angle of about 5° from the vertical.
Claim 22
Dependent Claim
84 words
A tundish for use in the teeming of molten metals having a generally horizontally extending base, and a width; and a board of refractory material positioned generally upright in the tundish, across the width of the tundish, said board having a plurality of apertures through it through which steel can pass, said board having at the lower part of one face a gas-permeable portion through which gas can pass outwardly, and ducting for the supply of gas to the back of the gas-permeable portion.
Claim 23
Dependent Claim
84 words
A tundish for use in the teeming of molten metals having a generally horizontally extending base, and a width; and a board of refractory material positioned generally upright in the tundish, across the width of the tundish, said board having a plurality of apertures through it through which steel can pass, said board having at the lower part of one face a gas-permeable portion through which gas can pass outwardly, and ducting for the supply of gas to the back of the gas-permeable portion.
Claim 24
Dependent Claim
29 words
Apparatus as recited in claim 17 wherein said gas-permeable portion is of refractory material of low gas-permeability having at least on opening in it through which gas can pass.
Claim 25
Dependent Claim
17 words
Apparatus as recited in claim 17 wherein said gas-permeable portion is of refractory material of high gas-permeability.
Claim 26
Dependent Claim
45 words
Apparatus as recited in claim 17 wherein the ducting comprises a pipe imbedded in the board, with an access point at the top, and having at the lower part of the board at least one opening open to the back of the gas permeable portion.
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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) | 1990-05-25 | 1990-11-24 | 1991-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-25 | 1994-11-24 | 1995-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-25 | 1998-11-24 | 1999-05-26 | $7700.00 | Window Closed / Lapsed |