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Publication numberUS3749387 A
Publication typeGrant
Publication dateJul 31, 1973
Filing dateMar 16, 1972
Priority dateMar 16, 1972
Publication numberUS 3749387 A, US 3749387A, US-A-3749387, US3749387 A, US3749387A
InventorsAndrzejak S, Berg R
Original AssigneeUnited States Steel Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and device for shrouding a stream of metal teemed through a slidable gate
US 3749387 A
Abstract
An extended tube nozzle construction in conjunction with a slidable gate for bottom pouring molten metal. Includes a telescoping shroud plate which rests on the receiving vessel when in the operating position.
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Description  (OCR text may contain errors)

United States Patent 1 Andrzejak et a1.

[ 1 July 31, 1973 METHOD AND DEVICE FOR SIIROUDING A {58] Field of Search [64/66, 136, 281, STREAM OF METAL TEEMED THROUGH A 164/337; 222/512; 266/34 V, 38

SLIDABLE GATE I75 I Inventors: Sigmund L. Andrzejak, Chicago; [56] Raymond B. Berg, Calumet City, v UNITED STATES PATENTS both Of 1". 1,417,269 5/1922 MacMichael et a1. 164/337 3,501,068 3/1970 Shapland 222/512 [73] Assignee: United States Steel Corporation,

Pittsburgh, Pa. Primary Examiner-Gera1d A. Dost 221 Filed: Mar. 16, 1912 [211 App]. No.: 235,387 [57 ABSTRACT Rehted s Application Data An extended tube nozzle construction in conjunction [63] continuation of Ser. No 4 965 Jan 22 1970 with a slidable gate for bottom pouring molten metal. abandoned Includes a telescoping shroud plate which rests on the receiving vessel when in the operating position,

[52] U.S. Cl 266/38, 164/136, 164/281, 2 Claims, 3 Drawing Figures [51] Int. Cl C211) 7/14 p I I lo I5 I I9 ,1: I'll I 20 27 29 22 ":2 if 2 28 E PATENIED JUL3 I I975 INVENTORS 8 RAYMOND B. BERG Alla/0g SIGMUND L. ANDRZEJAK METHOD AND DEVICE FOR SIIROUDING A STREAM OF METAL TEEMED THROUGH A SLIDABLE GATE This application is a continuation of Ser. No. 4,965, filed Jan. 22, l970, and now abandoned.

This invention relates to an improvedmethod and device for shrouding a stream of metal teemed through a slidable gate.

Although our invention is not thus limited, the apparatus is particularly advantageous as applied to a continuous-casting operation for steel. Oxides of iron and of deoxidizers added to the steel in the furnace or the ladle form as the molten steel is teemed through air into a receiving vessel, such as a continuouscasting mold. These oxides, such as iron oxide, alumina and silica, are insoluble in molten steel and form a slag-like layer which floats on the surface of the molten steel in the mold. The oxides collect near the mold walls and descend with the steel casting along the surface thereof. As the casting surface solidifies, the oxides solidify on or near the casting surface. The oxides impair the quality of the surface and must be removed by suitable treatment such as scarfing.

Exposure of the molten steel stream to air during teeming also results in surface cracks, pits, scabs and ripples due to the turbulence of the steel stream caused by entrainment of air.

In order to minimize oxidation of steel as it is teemed and to minimize surface irregularities due to a turbulent steel stream, it is known to protect the stream from exposure to air during teeming. This is commonly accomplished by providing an enclosed passageway in the form of a tube for the pouring stream, which tube extends downwardly from ,the teeming vessel into the mold. However, when such tube is used in combination with a slidable gate mechanism, the tube must be positioned beforehand and the gate mustoperate above the tube. Thus itcan be seen that such a tube must necessarily be affixed to the mold. This requires a complex mold-top design, and changing tubes during a cast is virtually impossible. I i v It is an object of our invention to provide a slidable gate apparatus which'includes an enclosed passage for molten metal;

Another objectis to provide a simple inexpensive i method and means of shrouding the pouring stream,

and molten metal in a mold when the pouring vessel is equipped with a slidable gate.

A further object of this invention is to provide a pouring device which protects molten metal from oxidation by air as the metal is teemed from a ladle through a slidable gate into a continuous-casting mold. v

Thetube of our invention is integral withand extends downwardly from a slidable gate and'moves into position over the mold cavity with the gate. The tube carries a telescoping shroud plate which, when released, slides down the fixed tube into the operative position against the mold cover.

In the drawings:

FIG. I is a vertical sectional view of portions of a bottom-pour vessel and a receiving vessel, showing our improved protective device.

FIG. 2 is a horizontal section taken along line IIII of FIG. 1.

FIG. 3 is an alternative embodiment in which the protective device extends into the receiving vessel.

FIG. 1 shows portions of a conventional bottom-pour vessel 10 and receiving vessel I2,both of which are refractory lined for containingmolten metal. In the example of a continuous-casting operation, vessel 12 is a mold which oscillates vertically, as known in the art. The bottom wall of the bottom-pour vessel has an outlet opening 14 and carries a refractory discharge nozzle 15 fixed to its underside aligned with the opening. Also as known in the art, a series of slidable gates 16 is mounted beneath the nozzle. The gates can be supported and operated in any desired manner; hence we have not shown the supporting and operating mechanism. In accordance with our invention, each gate comprises an extended refractory tube 18 surrounded by a refractory insert 19 and a steel frame 20. Slidablydisposed on tube 18 is a shroud plate 22 which comprises an impact-resistant refractory insert 23, a steel frame 24 surrounding the insert, and a graphite lubricating ring 25. Tube 18 can be covered by a steel sleeve (not shown) if desired. Tubes of varying lengths may be provided for successive gates, as the tube is of fixed length. Eyelets 27 and 28 are affixed to the upper and lower frames respectively. Before the gate is aligned with the nozzle, shroud plate 22 is held in the upper or standby position by a hook or wire 29 which fastens eyelet 28 to. eyelet 27 as shown at the right of FIG. 1. When the hook is unlatched or the wire is cut, shroud plate 22 slides down tube 18 into operating position atop mold cover l2, as shown at the left of FIG. I. The resulting impact requires that the refractory insert 23 be a highly fracture-resistant material. The graphite lubricating ring 25 provides lubrication as the shroud plate 22 oscillates with the mold. Both gate '16 and shroud plate 22 are disposable, as they are simple low cost items. Shroud plate 22 hasa view port 31' of a heat-resistant transparentmaterial and an opening 32 to permit the introduction of an inert gas to the top of the mold.

FIG. 3 depicts an alternative embodiment wherein'a shroud plate 35 is permanently affixed to alower refractory tube 36 which is slidably disposed'on' upper tube 37. The lower tube may extend into the receiving vessel 38 as far as desired, limited only by the distance required by the tube to clear the receiving vessel when in the upper or standby position. 1 I 1 The additional tube extension beneath the top of the mold reducesturbulence in the mold, thus helping to prevent breakouts. When changing an active gate having a tube which extends into the mold, the telescoping portion isfirst raised manually by lifting eyelet 39. When the shroud plate is in' the operative positiona'top the mold and an inert gas such as argon" is 'being'introduced through opening 32, substantially all atmospheric oxygen is excluded from the molten steel.

From the foregoing description it is seen that our invention affords a simple effective construction for maintaining an enclosed passage between a bottompour vessel and a receiving vessel. Since all parts are integral with a slidable gate, the receiving vessel need not be of a special design. Further, if any difficulty arises during teeming, a defective extended tube gate can be easily replaced by a new gate or teeming can be interrupted by use of a regular closure gate.

We claim:

1. In combination, a bottom-pour vessel having an outlet in its bottom wall, a receiving vessel which oscillates vertically and has an opening in its top beneath said bottom-pour vessel and an apparatus for teeming sel, and releasable means which connects said plate to said gate and supports said shroud plate in said raised position on said tube. I

2. An improvement as defined in claim I in which said shroud-plate comprises a metal frame, an impact resistant refractory insert in said frame, said insert having a substantially vertical hole therethrough, a graphtube with said outlet and said opening, and a lowered position in which it engages the top of, covers the opening of and oscillates vertically with said receiving vesite lubricating ring fixed in said hole, and means attached to said frame for engaging said releasable t i t i f

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1417269 *Dec 14, 1920May 23, 1922 Means for casting ingots
US3501068 *May 21, 1968Mar 17, 1970United States Steel CorpBottom-pour teeming vessel with sliding gate and pouring tube
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4119411 *Nov 22, 1976Oct 10, 1978British Gas CorporationCoal gasification plant
US4121651 *Apr 25, 1977Oct 24, 1978Dino Marco ZeppelliniCasting receptacle or ladle for moulded castings or various materials
US4369831 *Nov 30, 1979Jan 25, 1983Sumitomo Electric Industries, Ltd.Protector for molten metal casting stream
US4669528 *Jan 22, 1986Jun 2, 1987International Industrial Engineering SprlDevice for introducing and exchanging a casting tube
US4840297 *Aug 5, 1988Jun 20, 1989Vac Tec, Inc.Apparatus for shielding a molten metal stream
Classifications
U.S. Classification222/512, 164/439, 164/337, 164/136
International ClassificationB22D41/22, B22D41/24, B22D41/50
Cooperative ClassificationB22D41/50, B22D41/24
European ClassificationB22D41/50, B22D41/24
Legal Events
DateCodeEventDescription
Mar 31, 1989ASAssignment
Owner name: USX CORPORATION, A CORP. OF DE, STATELESS
Free format text: MERGER;ASSIGNOR:UNITED STATES STEEL CORPORATION (MERGED INTO);REEL/FRAME:005060/0960
Effective date: 19880112