US2175375A - Casting ladle - Google Patents

Description

Oct. 10, 1939. CH ET AL 2,175,375

CASTING LADLE Filed May 8, 1937 15 5 I f T T" T/ \"R lNVENTORs Patented Oct. 10, 1939 UNITED STATES CASTING LADLE Adolphe Busche, Woodbridge, and John H. Jago, Fords, N. J assignors to American smelting and Refining Company, New York, N. Y., a corporation of New Jersey Application May a, 1937, :Serial No. 141,434"

3 Claims.

The present invention relates to the casting of copper wire bars, and relates, more specifically, to an improved mechanism for filling the mold in which the wire bars are cast.

When imperfections are present in the wirebar castings, such imperfections persist. throughout the wire-fabricating operations and are present in the finished wire.

In the casting of such wire bars it is the general practice to mount the molds on a suitable conveyor mechanism, such as a casting wheel, whereby the molds are brought successively beneath the pouring ladle which receives the metal from the furnace, and which discharges the metal into the molds. Each mold comprises a plurality of mold cavities or recesses in parallel alignment for the simultaneous casting of a plurality of wire bars, and, depending upon the construction or type of the casting wheel, the molds are mounted with these mold cavities extending either radially or tangentially of the wheel.

In either case, the ladles employed for trans ferring the copper from the furnace to the molds are composed of a shell of cast iron provided with a lining of refractory cement of suflicient or suitable thicknessi The copper enters the ladle from the furnace and, upon suitable tilting of the ladle, flows therefrom into the wire bar molds which are coated with a suitable mold dressing usually consisting essentially of bone-ash.

During pouring operations, especially where the molds are disposed tangentially of the periphery of the wheel, the ladle may have an overall length of several feet along which the copper flows in transit to the pouring spout, the copper thereby becoming coated with a film of copper oxide due to-contact of the copper with the air. This copper oxide wets the cement and causes spalling of the same with the result that parts of the cement become mechanically separatedfrom the ladle and entrapped in the casting; and also the bone-ash mold dressing is wetted by this copper oxide and some of it becomes included in the wire-bar castings. These inclusions must be removed from the wire-bars before shipment thereof is made to the fabricator, and at times the handling and manipulation of the bars becomes uneconomical because of the chipping operations thereon required to eliminate these foreign inclusions.

Additionally, during the intervals between pours, there is the tendency of the copper to solidify in the ladle and in the pour openings, forming accretions or skulls which adhere to the cement lining of the ladle, the removal of such accretions usually pulling some of the cement along with them, with the consequence that further amounts of the cement become loosened and are washed out into the molds upon the next pouring of the copper.

One object of the present invention is to provide a ladle construction wherein the molten copper is protected against contact with excessive amounts of air during pouring and wherein the formation of the above-mentioned accretions. and skulls is inhibited or avoided.

. A further object of the invention is to provide a ladle which is adapted especially for use in casting wire bars where the wire-bar molds are disposed tangentially to the circumference of the casting wheel upon which the molds are mounted, the said ladle being provided with laterally extending discharge spouts.

A still further object of the invention is to provide a ladle which comprises a metal delivery 'member or launder having a heat-insulating cover sealed in place thereon, and in which dis-,

charge openings are round holes extending through a'comparatively thick body of heat in sulating material forming the spouts.

Further objects and advantages of the present invention will become apparent as the descrip-' tion proceeds, and the features of novelty will be pointed out specifically in the appended claims.

The invention will be understood more readily by 'a reference to the accompanying drawing in which Fig; 1 is a perspective view of a wire bar mold with metal receiving portion in casting position relative to a ladle which employs the improved features of the present invention.

Fig 2 is a plan view of a portion of the ladle.

Fig. 3 is a front elevation of the discharge portion of the ladle.

Fig. 4 is a sectional elevation taken onthe line of Fig. 3, looking in the direction of the arrows.

Fig. 5 is a longitudinal sectional elevation, taken on the line 5-5 of Fig. 2.

Referring more particularly to the drawing, A represents a wire-bar mold which is adapted to receive metal from a ladle B, into which copper enters from a suitable wire-bar furnace, not

shown. The ladle B comprises a reservoir portion 6 and a.discharge launder 8, which comprises a channel 9 communicating therewith, the said launder being composed of a metal shell Ill lined with a refractory cement l2. Atypical composition of this cement inay be Portland cement, 2 parts by weight; building sand, 2 parts by weight; and fire-clay, 1 .part by weight. ,A baille or bridge member I separates the launder 8 from the reservoir 6, a passage H beneath the bridge 1 being providedto allow for flow of metal between the reservoir and launder. The bridge I is suitably secured in place'in the walls of the channel 9. This passage II is provided by deepening the bottom l3 of the launder atthe bridge sufliciently to maintain a suitable head of metal in the reservoir 6 which. forms also a seal thereby, passage of air from the reservoir 6 into the launder 8.

The launder 8 is provided with a plurality (four,

for example) of laterally-extending discharge spouts Ii, formed by extending outwardly at suitable points, the shell I!) of the launder and building up the cement lining in these extensions to a sufficient thickness for eflicient heat insulation. In order to form the discharge holes for the metal, a pipe of suitable diameter-is inserted through the cement of these spouts before the cement becomes hardened until the pipes enter the launder trough 9 adjacent to the bottom I 3 thereof, the pipes being given a downward slope towards the launder channel 9. When the pipes have been inserted completely through the spouts, they are withdrawn, leaving the holes 18 surrounded by comparatively thick layers of heat insulation which prevents solidification of the copper at the discarge points of the ladle, thereby avoiding the formation of the so-called skulls" referred to above. These discharge holes or passages are of uniform diameter, for example, 1% inches, and are disposed in the same horizontal plane, there being provided as many such discharge spouts as there are wire-bar mold cavities in each mold.

As each mold A moves under the launder 8, the mold cavities H are directly beneath therespective discharge spouts, so that each spout will deliver a stream of metal to the mold cavity directlv beneath it. The ladle is tilted by any well-known type of tilting mechanism, whereupon the molten copper flows beneath the bridge 1 into the launder 8 and through the discharge holes l8 to fill the molds. The discharge holes I 8 being of the same dimension and being supplied with metal under the same head, and being in the same horizontal plane, there is provided a control of the amount of copper being poured in a given time, thereby producing wire-bars of greater uniformity of weight.

A further feature of the present improved construction lies in the provision of a thick brick cover which extends from the distal end of the launder to the bridge member 1. For holding this cover in place, the launder 8 is provided with a frame 20 along its top, which frame is formed, conveniently, of inverted L-shaped angle members having their vertical leg embedded in the body of .the launder, with their horizontal leg towards each other, these horizontal legs forming retaining flanges for holding the brick cover in position against the top of the launder. The cover 22 is sealed air-tight, by means of a refractory seal 24, which may extend over the top of the cover.

This sealed cover construction has at least two important functions; that is to say,.it prevents heat losses with consequent building up of solid copper accretions along the walls of the launderchannel 9, during casting operations, and it also excludes air from contacting with the copper as it flows through the launder 8. It will be understood that the molten copper contained in the reservoir 6 is protected from the air by a suitable layer of charcoal or the like in accordance with usual practice.

Access of air to the copper in the launder 8 is inhibited also by the round or restricted discharge passages l8 and by the slope of the latter, which causes the molten copper to tend to seal these discharge passages against admission of large amounts of air, which admission is also restricted by the fact that the interior of the launder is sealed by the bridge I with the body of metal therebeneath and by the air-tight cover 22.

Therefore, the launder becomes essentially a dead-air space through which the copper flows for pouring, and since there is substantial exclusion of fresh air from entering the launder, the formation of a copper oxide film on the copper is obviated very substantially; also, because of the highly heat-insulating character of the construction, the formation of frozen copper accretions and/or skulls in the launder and discharge spouts is prevented, so that there results virtually complete elimination of inclusion of cement in the cast bars, with the consequent very material reduction in the amount of chipping necessary to prepare the cast bars for shipment to the wire mill.

What is claimed is:

1. A ladle for use in casting copper wire-bars,

which comprises a reservoir portion, and a launfrom the said trough and having discharge openings enclosed completely in a relatively thick body of heat-insulating material, a retaining frame for the cover extending along each side of the trough and engaging the cover to secure the same in position on the trough, and a refractory seal enclosing the cover along the lines of juncture thereof with the said launder trough, thereby preventing formation of substantial amounts of copper oxide during the pouring of the metal.

2. Apparatus for casting copper wire-bars comprising the combination with wire-bar molds having mold cavities disposed tangentially of the circumference of the mold, of a ladle having a launder portion extending over the molds and comprising discharge spouts extending laterally from the launder over the mold cavities for directing copper from the launder into the said cavities, and means for the launder and the spout for protecting the copper against oxidation as it passes from the melting furnace to the molds.

3. Apparatus for casting co'pper wire-bars,

comprising the combination with wire-bar molds,

of a ladle for pouring metal from a melting furnace into the said molds, the said ladle comprising a trough-like launder, a plurality of laterally disposed discharge spouts extending from the launder over the molds as the latter are moved into casting position, an angle-frame extending

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