US2618477A - Metal transfer system - Google Patents

Description

NOV. 18, 1952 SHORT 2,618,477

METAL TRANSFER SYSTEM Filed Feb. 11, 1949 INVENTOR. fferberi 1?. Shore BY 7. 12 v 14 1;

Patented Nov. 18, 1952 METAL TRANSFER SYSTEM Herbert M. Short, Bridgeville, Pa., assignor to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania Application February 11, 1949, Serial No. 75,819

2 Claims. I

This invention relates to a metal transfer system or device particularly useful in the handling of those metals, such as aluminum or aluminum alloy, which form, on those molten surfaces which are exposed to the atmosphere, an oxide coating. During the transfer of such molten metal it is desirable to create conditions under which the oxide coating originally formed by the initial exposure of molten metal to the atmosphere is maintained and is not ruptured and consequently entrained in the flowing metal. Such conditions necessarily include a relatively quiet, non-turbulent how of metal from splashing, cascading or like effects so that large areas of molten metal are not exposed to the atmosphere and so that the oxide film or skin formed on the exposed surfaces of the metal rests quietly thereon and is not continually drawn into the metal. The transfer system of the present invention is specifically designed to achieve such quiet, non-turbulent transfer and is useful not only in the handling of those metals which form such oxide coatings but also in the handling of any metal where a quiet fiow of metal is desired from a source, such as a furnace, a pot or a crucible, to a receivin receptacle such as an ingot mold, a feed trough, a crucible, a holding pot or the like.

For convenience, and by way of showing a preferred example of one embodiment of the invention, reference will be made in the following description to the drawing, in which:

Fig. 1 is a longitudinal elevation, in cross section, through one form of the subject transfer system, shown as adapted to the transfer of metal from a holding furnace to a receiving trough;

Fig. 2 is a similar longitudinal elevation, in cross section, through one portion of the assembly shown in Fig. 1, some of the elements of the assembly being shown in another position; and

Fig. 3 is a top view of the portion of the transfor system shown in Fig. 2.

Referring to the drawing, the molten metal source or f-urnace 25 is shown in Fig. 1 as containing molten metal to the level A. Seated through and in sealed engagement with the wall of the furnace is a pouring spout ID, to which is attached a basin II. Molten metal is indicated as held in said spout and basin to the level B. The end of the pouring spout which is seated through the wall of furnace 25 is shaped to form a restricted passage I5 through which metal may pass from the furnace into spout I and the basin II. The passage I may be temporarily 2 sealed to prevent metal flow to the spout by any conventional device, such as the tap rod I6, and when the passage is open flow of metal therethrough may be controlled by any device. For convenient handling the tap rod I6 is here shown as supported by the cross bar 23. The basin II is provided with a downwardl extending discharge passage or nipple I3, provided with an orifice I4 through which molten metal may flow to a metal receiving receptacle, here shown as a trough I2. A sealing means, here shown as the rod I1, is mounted for vertical adjustment in block I9. The upper surface of rod I 'l is threaded to operate in screw threads provided in block I9 and vertical adjustment is made by turning the rod I! in the block I9. The closure rod I1 is so proportioned that its lower end will seat on the inner walls of nipple I3 to seal the passageway formed thereby and to thus prevent flow of molten metal from the basin II through the orifice M into the trough I2. A knob I 8 may be provided at the upper end of the rod I1 to facilitate vertical adjustment thereof with respect to the block I9. Block I9 is supported by means of legs 20 on a buoyant float 2| shaped to rest within the basin II. Lugs 22 attached to float 2| are positioned to extend over the wall of the basin II (best shown in Fig. 3) and are of a length such as will prevent the float 2| from contacting the bottom of basin II when no molten metal is present therein (the condition shown in Fig. 2).

Thu-s the floating valve assembly, including rod I1 and float 2I, produces a sealing or opening of the metal delivery passage I3 by moving the rod I'I into sealing register with the orifice I4 as the metal ebbs in basin II. Conversely, when the metal rises in basin II the fioat 2| is borne upwardly, thus movin rod I1 upwardly and away from sealing register with said orifice. It will be noted that the movement of the buoyant member 2| is limited, in that direction of movement which is caused by the ebb of the metal, by the action of lugs 22 or other movement limiting device.

At the beginning of a metal transfer operation the valve assembly is placed in the basin I I in the position indicated in Fig. 2, the lugs 22 bearing on the wall of the basin I I to hold the float 2I in a position above the floor of the basin. The rod I! is vertically adjusted to seat over the orifice I4 to either close or materially restrict the orifice I4. For this purpose the operator may vertically adjust rod H in block I9. The operator then opens the spout passage I5, by withdrawing tap rod l6, allowing metal to flow from the furnace 25, through spout l into the basin II. It will be noted that, because of its position above the floor of the basin, the float 2| will not initially be buoyed by the molten metal passing into the spout and that consequently the closure element I! will initially remain seated over the delivery orifice until such time as the rising level of molten metal in the spout reservoir causes the float 21 to rise, whereupon the closure element I! will be borne upwards, thereby opening the delivery Orifice M. The weight of the float 2| and the parts supported thereby may be so adjusted that the closure element I! does not free the metal delivery passage until the metal has arrived at a desired level in basin l I. Thereafter such level may be maintained by manipulation of the tap rod it in the restricted passage I5 to govern metal flow into the spout Ill from the furnace 25.

In the preferred device illustrated in the drawings it will be noted that the metal passage or nipple i3 is so proportioned as to extend to a point which will be below the level C of metal in the trough E2 so that the discharge port or orifice i l will lie below the metal level C. Thus when flow of metal is initiated in the system, the metal issuing from orifice i l will not drop a great distance to the floor of trough l2 and, once the metal level C is established in the trough E2, the discharge of metal through orifice It will be below the level of the metal in the trough.

Among the advantages secured by the use of the transfer system of this invention is the maintenance of the desired metal levels by operative adjustment at a single point. Thus in the device above described operative adjustment of the tap rod it will maintain constant the metal level B in the basin l i and the metal level C in the trough 12. Moreover it will be apparent that the basin and trough arrangement shown may be multiplied, where conditions require delivery of metal to more than one trough, without requiring the necessity for adjustment except at the point of flow of the metal from the metal source into the basin. Moreover, once metal flow has begun and the metal levels have been established, the transfer of the metal will proceed quietly, without turbulence or cascading and any oxide skin formed on the exposed surfaces at metal levels B and C will tend to remain quietly on such surfaces and will not be readily entrained by metal flowing through the basin and the trough.

Having thus described my invention, I claim:

1. In an apparatus for the quiet transfer of molten metal comprising, in combination, a metal transfer basin positioned to receive molten metal from a source thereof, a metal receiving receptacle positioned below said basin to receive discharge of metal from said basin and means for controlling the discharge of metal from said basin to said receptacle, the improvements consisting of walls formed to define a downwardly extending metal discharge orifice in the bottom of said basin, a buoyant valve assembly comprising a float member and a vertically adjustable downwardly extending sealing member mounted on said float member, said assembly being shaped to fit within said basin and positioned in said basin to float on metal contained therein with the sealing member of said assembly in vertical alignment with said orifice and means disposed to limit the vertical downward movement of said float member with said metal to a point above the bottom of said basin.

2. In an apparatus for the quiet transfer of molten metal comprising, in combination, a metal transfer basin positioned to receive molten metal from a source thereof, a metal receiving receptacle positioned below said basin to receive discharge of metal from said basin and means for controlling the discharge of metal; from said basin to said receptacle, the improvements consisting of walls formed to define a downwardly extending metal discharge orifice in the bottom of said basin, a buoyant valve assembly comprising a float member and a vertically adjustable downwardly extending sealing member mounted on said float member, said assembly being shaped to fit within said basin and positioned in said basin to float on metal contained therein with the sealing member of said assembly in vertical alignment with said orifice and means disposed to limit the vertical and lateral movement of said float member with said metal to a point above the bottom of said basin, said means consisting of members fixed to said float member and engageable with said basin.

HERBERT I'-/[. SHORT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,139,887 Mellen May 18, 1915 1,433,278 Hopkins Oct. 24, 1922 1,690,749 Moyer Nov. 6, 1928 2,301,027 Ennor Nov. 3, 1942

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