US3189315A

US3189315A - Teeming gate with consumable anti-splash shield

Info

Publication number: US3189315A
Application number: US248046A
Authority: US
Inventors: Ralph A Verna
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-12-28
Filing date: 1962-12-28
Publication date: 1965-06-15
Anticipated expiration: 1982-06-15

Description

R. A. VERNA. i i I 3,189,315 TEEMINGQ GATE WITH CONSUMABLE ANTI-SPLASH SHIELD June 15, 1965 Filed Dec. .28, 1962 INVENTOR.

RALPH A; l/ERNA A trorneys United States Patent 3,189,315 TEEMING GATE WITH CONSUMABLE ANTI-SPLASH SHIELD Ralph A. Verna, Scenery Hill, Pa. (Box 186, RD. 1, Daisytown, Pa.) Filed Dec. 28, 1962, Ser. No. 248,046 1 Claim. (Cl. 249-206) This invention relates to a teeming gate with a consumable anti-splash shield, and, more particularly, is for a teeming gate with a consumable anti-splash shield employed in the steelmaking industry for the prevention of metal splashes onto the walls of ingot molds during a teeming or pouring operation wherein molten steel produced in electric, open-hearth, or Bessemer furnaces is delivered from ladles into ingot molds.

Since the first solid form which steel takes is that of the ingot, it is important that the consistency of the ingot be maintained uniform throughout the dimensions of the mold. Any flaws in the steel ingot will adversely affect the quality or uniformity of the slab or bloom which is formed subsequently from the ingot by rolling operations. It is imperative, therefore, that pouring of molten steel from ladles into the molds, the teeming operation, takes place consistently and that the stream of metal not be permitted to impinge upon the walls of the mold. In such latter instance, the metal that inadvertently splashes on the mold walls solidifies rapidly and results in imperfections which must be removed from the ingot prior to its rolling to form slabs and the like. The removal of the resultant imperfections requires the loss of man hours and the employment of expensive time-consuming techniques such as scarfing machinery and equipment. Accordingly, undesirable tscabby metal is caused by improper pouring from the ladle into the ingot mold whereby metal is splashed against the side of the mold which sticks to the mold and becomes oxidized on the mold surface to appear as scabs on the ingot after the mold is stripped from the ingot. These scabs often show up after rolling in the form of slivers, and on plates they form serious defects. As a continuous layer of metal splash cools on the ingot mold Walls, its upper edges tend to bend inward and, as the rising liquid steel overflows them when the mold is becoming filled, become enfolded. Deleterious horizontal ingot cracks on or below and parallel to these folds and the folds themselves can produce unwanted surface seams in a rolled product.

In top-poured ingots defects caused by splashes are reduced by filling the mold rapidly so that the rising level of liquid steel covers the splashes before they can cool and oxidize. Rapid pouring is done by using larger or multiple nozzles which give rise to mechanical difficulties. Also, there is a danger, especially with higher pouring temperatures, that high pouring rates will lead to greater ingot cracking. Coatings applied to the mold Walls ofttimes are utilized, the coatings being of a material which tends to repel splashes. This practice, however, gives rise to annoying fumes from substances such as tar coatings and pitch. The temperature of the molds at the time they are coated is important to be maintained within a particular range because if the mold is too cold, the excessive amount of gas accompanying the coating decomposition by the liquid steel gives rise to sub-surface blowholes in the ingot. On the other hand, if the mold is too hot at the time the coating is applied, the coating is decomposed and the residue charged film has no initialeffect.

By the concept of the instant invention the top-pouring of liquid steel from ladles into molds is accomplished without splashing of the mold walls by providing a teeming funnel apparatus which includes a shield for encompassing the stream of metal flowing into the mold to a 3,189,315 Patented June 15, 1965 See plane just above the mold bottom whereby splashing by the stream outwardly against the mold walls isprevented. The tunnel shield is consumed by the liquid metal as it rises within the mold such that the cast ingot is homogeneous.

It is a principal object of the instant invention to provide a new and improved teeming funnel apparatus.

Another object is to provide an apparatus for prevention of metal splashes onto the side of molds in the top pouring of liquid steel from ladles into the molds.

A further object of this invention is the provision of a funnel with a heat destructible shield for surrounding a stream of liquid metal in a teeming operation.

A complete understanding of the invention may be had from the following detailed description of a specific embodiment thereof when read in conjunction with the appended drawings, wherein:

FIG. 1 is a plan view of the apparatus arranged with respect to a mold placed upon a stool;

FIG. 2 isa side elevational view of the apparatus showing mechanism for positioning of the mold funnel with respect to a mold;

FIG. 3 is a longitudinal sectional view of the apparatus and a mold taken along the line IIIl of FIG. 2 looking in the direction of the arrows; and

. FIG. 4 is a cross-sectional view of a modification of the teeming gate with elements thereof separated for clarity.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1,. which illustrates a preferred embodiment, a teeming funnel or gate generally designated by the numeral 11. The gate 11 includes a support cross-beam 12 which is borne at its ends on sole plates 13 fixed to the upper reaches of screw toggle presses or jacks 14 shown in detail in FIG. 2. The cross-beam 12' is triangular in cross section for the purpose of shedding molten steel therefrom which inadvertently may be poured on the beam, the line 15 designating the straight edge to which the inclined sides 16 of the beam 12 converge. The ends of the cross-beam 12 are provided with sockets or openings 17 into which may be positioned the tongs of an overhead crane, not shown, for removably installing the cross-beam on the sole plates 13 in the position shown in FIG. 1. The apertured ends of the cross-beam 12 are thickened and are arculately shaped on their undersides for ready positioning into matching depressions 18 provided in the sole plates 13, FIG. 2. The cross-beam supports a neck 19 of the gate 11 which rests upon a circular upstanding flange 21 provided intermediate the ends of the cross beam 12. The flange 21 is apertured as at 22, FIG. 3, and is counterbored to provide a step or circumferential ledge 23 on which the neck 19 is nested. The gate neck is a sand casting, for example, having a conical counterbore 24 and a central bore 25 which passes therethrough as best shown in FIG. 3.

Immediately beneath the cross-beam 12 but vertically spaced therefrom is an open-top ingot mold 26 which is of the conventional type employed in steel-making wherein the bottom of the mold is formed by a heavy plate or stool 2-7, which is in turn positioned on :a railroad car, not shown. Referring to FIGS. 2 and 3, the screw jack-s are shown placed on the upper edge of the mold wall at diametrically opposed locations. The jacks are merely rested on the upper edge of the mold Wall for subsequent removal when the teeming step is completed. The cross-beam 12 is positioned on the jack sole plates 13 by an overhead crane, for example, and is located to straddle the mold cavity.

A consumable shield 28 is fastened by suitable means to the flange 21 under the ledge 23,. FIG. 3. The material of which the shield 28 is composed may be any substance which is destr-uctiblc by the heat of the molten metal poured into the mold 26, examples of which may be steel, copper, aluminum, Wood, and plastic. The shield of the gate or funnel 11 is circular in cross section for the most part, and thus resembles a pipe in configuration. The inner diameter of the shield, however, is greater than the diameter of the central bore 25 of the neck 19 with which it is arranged coaxially for the purpose of enabling a molten metal stream to pass through the bore 25 .and continue downwardly into the mold 26 with the shield .28 surroun-dingly spaced from the stream. In this manner the hot metal does not melt the shield.

Posts or ribs 23 are integrally formed on the free end of the shield 29 for positioning the free end of the shield above the stool 27 or bottom of the mold 26. The ribs 29 may be in direct contact with the stool 27 under some circumstances; however, levelling of the cross-beam 12 by the jacks 14 or other levelling devices, not shown, is oftti'mes desired to align the axes of the shield 28 and the bore 25 vertically. This is best accomplished when the cross-piece 12 supports the shield 28 above the stool 27. In the latter event the ribs 29 are unnecessary because the molten stream flows from the shield under its free end onto the stool 27 to fill the mold 2.55. In either event, it is mandatory for best shielding results that the axes of the shield 28 and the bore 25 be vertical because the molten metal poured through the neck 19 should not contact the wall of the shield 26 on its passage onto the stool 27; otherwise, the shield 26 would be consumed prematurely.

As the level of the molten metal rises within the mold 26, the consumable shield 28 is destroyed by the heat of the metal, either rising to the top surface of the molten metal as charred material, or becoming assimilated into the molten mass. The shield is so elevated above the bottom of the mold that splashing of the metal onto the Wall of the mold from its initial impact upon the stool 2 7 or mold bottom 26 is arrested by the surrounding shield material. The rate of consumption of the shield material is predetermined by the proper choice of material which will melt at the known temperature of the metal undergoing the teeming operation such that after the initial introduction of metal into the bottom of the mold through the gate or funnel, the end of the shield is immersed within the molten pool of metal rising within the mold 26. By the time the level of the molten metal reaches the top of the mold as, that portion of the shield submerged within the molten metal has been completely destroyed. In this manner, only the casting or ingot metal completely fills the mold, and the sides of the mold are maintained free from metal which would splash onto the sides and form scabs in the absence of the shield 42.

The embodiment of the invention shown in FIG. 4

includes a cross-beam 12 provided with an integral flange 21 which is provided with a bore 22. The neck 19 of the gate 11 rests upon a ledge 23 which surrounds the opening 22 and from which extend a plurality of fastener pins 31. The pins are of sufiicient length to pass through a circumferential flange secured on the upper end of the shield 28. The flange 32 is apertured to receive the pins 31 therethrough, with the flange held on the pins 3 1 by wedge members driven in passages provided through the pins. The wedge member connection is not novel, and consequently does not per se form a part of the present invention. As explained hereinbcfore the jacks 14 are unnecessary when the axes of the shield 28 and neck 19 are vertical, as is indicated in FIG. 4.

It is manifest that the above-described embodiment of the invention is merely illustrative and that numerous modifications may be made within the spirit and scope of the invention. Further, it will be understood that the particular shield is only one example of a particular type of consumable gate which may be operated upon in practicing the invention, and that the invention is not limited to use with this one type of shield configuration.

What is claimed is:

A gate for an ingot mold comprising a neck portion of refractory material, a heat destructible elongated shield portion, the neck portion and the shield portion having coaxially arrange-d bores therethrough with the shield portion bore larger than that of the neck portion, a cross-beam with a flange centrally positioned thereon and provide-d with a passage through the flange, the passage being of stepped diameter forming a ledge, the gate neck portion being nested within the flange on the ledge, the consumable shield being fastened to the flange, and means for leveling the cross-beam for positioning the consumable portion of the gate dependingly within an ingot mold, the consumable portion having spaced ribs extending from the lower end thereof for positioning the consumable gate portion relative to a mold bottom with said ribs providing passages through which molten metal is initially introduced into a mold without splashing.

References Cited by the Examiner UNITED STATES PATENTS 3,013,316 12/61 Hornak et al. 22-209 3,030,679 4/62 Daussan 22-147 FOREIGN PATENTS 216,688 8/61 Austria. 1,132,297 6/ 62 Germany.

MARCUS U. LYONS, Primary Examiner. MECHAEL V. BRINDESI, Examiner.