US2329049A - Apparatus for pouring molten metal - Google Patents

Description

Sept. 7, 1943. r. M. HULME APPARATUS FOR POURING MOLTEN METAL Fledl'arch 14, 1942 2 Sheets-Sheet 1 E um www muy WH. s MMMA p MMM mlm Sept. 7, 1943. P M HULME' f I2,329,049

APPARATUS FOR POURIQ MOLTEN MTAL Filed March 14, 1942 Sheets-Sheet 2 ICI l UNITED y msssrusron nonnina 3.,' :kunnen "Philip M. lulmo, elle f International a 'corporation o! assalti" .5 1 f imam" i .Application im, serial No. 34,742

This invention relates to apparatus for pouring molten metal, and has for its principal object to provide improved apparatus of this character. More particularly the invention contemplates the provision of an improved tilting'ladle for receiving molten metal from a meltingfurnace and for pouring the metal into molds.

Ordinarilyv ladies for receivingl metal from a furnace and for pouring it into a mold consist of open vessels into which the metal runs from a furnace tap hole. 'I'he ladle may then be carrled to the molds into which the metal is to be cast. Other types of ladies consist of open tiltable vessels into which the molten metal runs substantially continuously from the furnace, and which may be intermittenly tilted t0 pour the' molten metal into molds as the latter are brought into position before the ladle. Such ladies are simple to make and to use', and are quite satisfactory in cases where'contact between the-molten metal and the atmosphere is not objectionable.

' In United States Patent No. 2,265,284, granted tion gases into the heatingchamber. whereby the December 9, 1941, on yan application of Philip M. v

Hulme and Robert A. Ghelardi. assigned to the same assignee as this application, there is described a novel process for melting copper by means of radiant heat in a'fuel-fired mums type furnace. Copper melted by'this process is silb-` stantially as pure as the solid Coppel' charged into'v the melting furnace. If cathode copper is used as the solid charge, the molten ,copper produced in the furnace isvery'pur'e and substantially Oxyl gen-free. If upon withdrawing this molten cop-- per from the furnace it is allowed to come in contact withthe air, it rapidly combines with atmospheric oxygen. Consequently, the copper must be withdrawn from the furnace and cast without moltenmetal therein 'may bel heated by means ofradiant heat derived by the burning of'fuel.

This arrangement enables the molten metal to be 'kept in the molten state and at a suitable casting temperature by burning an inexpensive fuel, but without permitting the metal to come in contact with and be contaminated by lthe gaseous cornbustion products.

'I'he new pouring apparatus comprises a tiltabls ladle having a molten metal chamber in the lower Iportion thereof and a heating chamber in the upper portion. A thin,substantially gas-tight wall of heat-conducting refractory separates the metal chamber from the heating chamber. Means are provided for introducing hot combuswall may be heated to an elevated temperature and may thereby supply sumcient radiant heat to the metal in the metal chamber to maintain it in the molten condition'and at a suitable casting'temperature, without allowing the metal'to come in contact with any deleterious combustion gases.

Means are ofcourse lprovided for introducing molten metal into the' metal chamber in the ladle. Advantageously a .refractory lconduit extending from the upper exterior of the ladle through the heating chamber and the' wall, and openinginto the metal chamber, isprovided for this purpose.

Molten metal then may be poured from above the ladlethrough the conduit directly into ythe metalchamber without coming in contact with deleterious combustion gasesl in the heatingV chamber.

The ladle advantageously. is substantially cylindrical `and is tiltable about its axis. The substantially cylindrical upper exterior surface coming in contact'wlth the air if substantially.A

oxygen-free cast shapesl are to be produced.

In my copending application SerlalNo. 434,741,

mates with a corresponding curved surface of the installs delivered to the ladle. By virtue of these curved surfaces, the'ladle may be tipped without creating any substantial aperture between. the ladle and the launder.

The conduit through which molten metal is fed from above the ladle into the metal chamber opens to the exterior of the ladle immediately ratus especially suitable for use in combination with a launder of the character described in my aforementioned copending application. whereby' the molten copper withdrawn through the launder may be poured 'intermittently into molds' without permitting contact of the metal with the air. The invention further providesa form of pouring apparatus such that thecharge of below `the discharge from the launder, so as to receive metal from the launder. The mouth of the conduit adjacent thev launder preferably is sum- AoiexrtlyiIride so thatmetal may run continuously j tlia-launder into the conduit even during normal tilting of the ladle.

The ladle of course is provided with a discharge spout through which molten metal may be poured lili into a mold when the ladle is tilted. v

launder or other structure through which molten The new pouring apparatus will be better understood from the following description of the preferred embodiment shown in the accompanying drawings, in which Fig. l is a vertical. section through pouring apparatus constructed according to the invention and through the end portion of a launder for delivering molten metal to the ladle;

Fig., 2 is a front elevation of the ladle shown .in Fig. 1; and

Fig. 3 is a plan looking down on'the ladle shown in Figs. l and 2. g

The ladle shown in the drawings comprises an outer steel shell I which is generally 'cylindrical in cross section. Trunnions' Ii are secured substantially axially to the shell it at the ends of the ladle. The trunnions II are carried in journals I2 which in turn are mounted on a ladle car I3. As shown in the drawings, the ladle car Is is supported by wheels M and ,le riding on channel-beam tracks it. The wheels It riding on the top nange of the tracks it, carrythe weight of the car it and of the ladle. The wheels l5, engaging with the undersurface of the track top flange, serve to prevent the car I3 from tipping. By thus supporting the ladle on apar, it may be moved axially should this be desired for convenience in making any necessary repairs. It is understood, however, that it is not necessary for the ladle to be mounted on a movable car in the manner above described.

The steel shell Ell of the ladle is lined with refractory. An outer layer of insulating refractory I'i and an inner layer of refractory silica brick I8 are shownin the drawings. Any refractory or combination of refractories suitable for withstanding attack by lthe hot molten metal carried in the ladle may be employed.

rI'he interior of the refractory-line ladle is divided into a lower metal chamber 2@ and an upper combustion chamber 2l by means of a thin refractory wall 22. An oil burner or other fuel burner t@ extends through the refractory wall at one end of the combustion chamber 2 I, for the purpose of introducing and burning iuel in the combustion chamber. The hot combustion gases thereby produced come in contact with the thin wall 22 forming the floor of the combustion chamber, and pass the length of the combustion chamber to an otalce flue 2d. From the flue 2 the gases pass to a chimney flue 25. A hood 2t at the base ofthe chimney flue 2d serves to direct 4the combustion gases fromthe otake ue 2t into the chimney flue 25, without. preventing normal tilting of the ladle on its trunnions II. If desired, the gases may be delivered by the ue 25 l to a waste heat boiler or other heat-recuperating means before they are allowed to escape to the atmosphere.

The thin refractory wall 22 forms a substantiallygas-tight barrier between the combustion chamber 2i and the metal vchamber 2li, so that prises a there is no opportunity for deleterious components of the combustion gases to come in contact with molten metal in the metal chamber. The wall 22, however, should be thin and made of a refractory having good heat-conducting properties, such, for example, as silicon carbide. The het combustion gases heat the wall 22 suiciently so that it may supply radiant heat to themetal in the metal chamber and may thereby maintain it at van elevated temperature above the melting point of the metal and high enough for. satisfactory casting.

The above-described arrangement for supply- .and housing Zit.

accepte ing radiant heat tothe metal in the ladle permits providing this heat by the inexpensive process of burning a fuel, but without permitting the molten copper or other metal to be contaminated by the deleterious products of the fuel combustion. 0f course, some of the heat is transierred to the molten metal by conduction through the refractory lining I8, rather than by radiation from the wall I8, but this mode of heat transfer obviously does not produce any detrimental effect.

A conduit in the form of a refractory pipe 21 extends from the upper exterior of the ladley through the refractory layers I'Iv and I8, the combustion chamber. 2| and the wall 22, and opens into the metal chamber 20. This refractory pipe provides means for pouring molten metal from above the ladle directly into the metal chamber, without permitting the metal to come in contact with contaminating gases in the combustion chamber. Silicon carbide is a satisfactory material from which to form the pipe 21. As illustrated in Fig. 1, the ladle advantageously is used in combination with a launder of the character described and claimed inV my aforementioned copending application Serial No. 434,- 741, led March 14, 1942. This'launder comfuliy enclosed trough 28 through which molten metal flows to its discharge end 29. A housing 3G; at the end of the launder structure provides an enclosure about the discharge end 2Q of the launder trough. The housing 30 may be fitted with a window 3| to permit observation of the molten metalas it flows from the discharge end of the launder into the ladle. The upper cylindrical surface 32 of the ladle shell mates 'with a corresponding cylindrically curved surface at the underside of the launder structure The4 axis of the cylindrically curved portion 32 of the ladle, and of the mating curved surface of the launder structure, coincides with the axis of the trunnions II. The ladle therefore may be tilted von its trunnions without creating any substantial aperture between the launder and the ladle.

The ladle is of course positioned so that the mouth of the pipe 2l at the exterior of the ladle lies directly beneath the discharge end 29'01 the ladle trough. Hence molten metal flowing from the launder falls through the pipe 21 into the metal chamber 2i). Inasmuch as there is no substantial aperture between the launder and the ladle, the metal from the launder passes into` the ladle without cominginto contact with the atmosphere.

As described in my aforementioned copending application Serial No. 434,741, means may be provided i'or introducing a protective gas atmosphere into the enclosed trough 28, preferably under a slight positive pressure. Any protective gas introduced into the enclosed trough 2B will of course pass freely into the pipe 2l and the metal chamber 2li of the ladle, thereby providing additional protection against contact of the molten copper or other metal with any deleterious gas. Moreover, such protective gas introduced under slight positive pressure into the enclosed trough Il@ of the launder will slowly flow out through any slight aperture or crack that may unavoidably exist at the juncture between the ladle and the launder, and so will provide a gas seal effectively preventing the entrance of air into ie interior of the launder trough 28 or the pipe a. Y 4

The mouth of the pipe 21 advantageously is v euiliciently wide so that molten metal may being of the order of 5 to 15 degrees.

the flow of metal from .y essary.

flow into it continuously from the discharge end of l the launder, even during normal tilting of the,

ladle. ll'or this reason it is generally advantageous'to make the pipe 21 oval in cross section, asshown in Fig. 3, and to mount the pipe so that its greatest internal diameter is at a right angle I 2,329,049 'in the nale. 'rnebottohi' oec-.tai hopper u is closed by a manually operated or gate 48,

below which is ,a condui extendingthrough the housing IIY-attheend ofthe launder to a' point directly-above thepipe Il. When the valve. or gate 41 is operat'edby turning the wheel 4l, a,

slug of the alloying'ingredient may be dropped to the axis about. whichl the ladle tilts. The

maximum diameter of the pipe 21 necessary to Venable it to yreceive a continuous flow of metal of course depends on the angle through which the ladle is designed to be.. tilted during casting operations. Ordinarilyv this angle is-quite small,

, An opening 33 is formed through the refractory lining of. the ladle to permit molten metal to flow from the metal chamber to the pouring spout. The spout may consist simply ofan open.-

ing 34 formed in the ladle shell. The opening 33 formed in the refractory advantageously slopes downwardlyfrom the spout 34 sothat it communicates with the interior of the metal cham,-

' ber wholly below the surface offthe molten metal in the ladle. In this manner any opportunity for air or other deleterious gas to gain access to the interior of the metal chamber through the spout 34 and the opening I3 is minimized. If desired, a refractory door 35 may be provided to close the opening $3 at all times except when actually pouring metal through the ladle spout. This door,

which may be opened and closedmanually, further insures against entrance of contaminating gases intothe metal chamber through the openman.

In order tov cast substantiallyoxygen-free metal from the ladle metal chamber into molds Il, a gas hood 3l may be provided. As shown in `the drawings. the outer surface of the ladle shell in the vicinity of the spout 34 is curved cylindrlcally, with the axis of curvature coinciding with the axis of the trunnions il on which the ladle is tilted.v The gas hood 31 is mounted on ythrough the pipej44 andthe refractory pipe 21 in to the molten metal in the ladle. Advantageously the kslugs'ofI alloying ingredientare of such size that the wheel 4l may bemanipulated to drop one into .the metal inthe ladle either Just to fill a mold. v

. '1. Apparatus for pouring'molten metal comprising a tiltable ladle having a molten metal before or Just after each 'the ladle is tilted chamber in the lower portion thereof and a corni--y bustion chamber in the upper portion thereof,

thin, substantially gas-tight wallriof heatcon-v ducting refractory material separating said metal chamber combustion chamber, means radiant heat to the metal in the molten metal for introducinghot combustion gases into thel combustion chamber in contact 'withsaid wall,V

whereby the wall may be heated toan elevatedtemperature and maythereby supply suillcient chamber to maintain said metalin the molten condition.- means for introducing' a continuous stream of inolten metal intothe metal chamber even during'tilting of the ladle, vand means for discharging molten metal therefrom upon tilting voi' the ladle. 'f

.2. Apparatuafor pouring` molten metal y.comprising a tiltable ladle having a molten metal chamber in the lower portion thereof and a combustion chamber in the upperportion thereof.

.a thin. substantially g -tlght wall of heat-conducting refractory ma rial separating said metal chamber from said co bustion chamber, means for introducing hot, combustion `gases into the stationary brackets and so does not tilt with the ladle, but where it joins .with the ladle, it is curved cylindrlcally to conform'with the` curvature of l the surface 38. Hence tilting of the ladle about its axis does not'create any substantial aperture between the ladle and the hood.

A' pipe 40 may be provided for introducing a protective gas into the interior of the pouring hood l1. An ample supply of protective gas should be delivered through the pipe 4I, so that when the mold 3l is brought into position beneath the hood il, the outflow of gasthrough the aperture between the hood and the mold is sufficient with 'gas just before being brought into .position lunder the hood I1. A funnel 4I may be built into the lprotective hoodso as properly to direct the ladle spout 34. into the mold 3|- Insome cases, as, for example, in phor-copper billets,'it is not necessary' to employ the hood 31 or equivalent protective device'. 'Ihe short time of contact-of the molten phosphor cop- 4 (per with-the air in flowing from the spout 34 into the mold Il is not 'ol' sumcientdu'ration to af fect the alloydetrimentally. However, in casting' oxygen-free high-conductivity copper. the'hood A hopper ttl silicon copper master alloy. into the molten m n .may be mended -for introducing elloying ingredients, such as' 'phosphor-coppe or v-u 4combustion v'cliaxnbyer in contact with said wall,

whereby the wall may beheated to an elevated temperature and `may thereby supply lsuitlcie'ant radiant heat to the metal in the molten metal cham'bejrfto maintain said metal in the molten conditidg'a refractory pipe open at both ends v extending through the combustion chamber and` toprevent the inilow of contaminating gases from v the'atmosphere.. The mold 38 mayitself be lled chamber in the lower portion of the interior of said 'ladle and a combustion vchamber inthe v upper portion of the interior thereof, a thin. substantially gas-tightwall of heatfgcon'ducting refractory material'eepara'ting said metal chams ber from saidcombustion chamber,`meansfor introducing vfhot combustion gases :into the-combustion'. chamber in contact with said wall.

- whereby the -wallvvmay be heatedto an elevated temperature and may thereby supply sumcient I l I1 or equivalent protective device is generally necradiant heat to they metal in the metal chamber to maintain it in the molten condition, means for introducing .av continuous stream of moltenY metal intoI the metal chamber even during tilting `loi' the ladle, and means for discharginl molten metal therefrom 4upon tilting of the ladle.

-4. A :nume-ladle of 'the described comprising a, tiltable vessel having a molten metal chamber in the lower portion thereof and a heating chamber in the upper vportion thereof, a thin, substantially gas-tight heat-conducting refractory wall separating said metal chamber from saidheating chamber but capable of receiving heat from within the heating chamber and of' transmitting radiant heat to metal in the metal chamber, means for introducing hot combustion gases into said heating chamber, means for introducing a continuous stream of molten metal into said metal chamber even during tilting of the ladle, and means for discharging metal from the metal chamber upon tilting of the ladle vessel. Y

5. A mulie ladle of the character described comprising a substantially cylindrical refractory lined vessel, means for tilting said vessel through an arc about its axis, a molten metal chamber in the lower portion of said'vessel and a combustion chamber in the upper portion thereof, a thin, substantially gas-tight heat-conducting wall separating said metal chamber from said combustion chamber but capable ci' receiving heat from within the combustion chamber and of transmitting radiant heat to :metal in the metal chamber, means for burning fuel in the combustion chamber, means for introducing a continuous stream of molten metal into the metal chamber even during tilting ci the ladle, and means for discharging molten metal therefrom upon tilting of the ladle vessel.

6. A inutile ladle of thecharacter described comprising a tlltable vessel having a molten metal chamber in the lower portion thereof and a heating chamber in the upper portion thereof, a thin, substantially gas-tight heat-conducting refractory wall separating said metal chamber from said heating chamber but capable of receiving heat from within the heating chamberl and of transmitting radiant heat to metal in the metal chamber, means for introducing hot combustion gases into said heating chamber, an enclosed conduit open at both ends extending through the heating chamber and opening into the metal chamber through which a continuous stream of molten metal may be introduced from above the ladle into the metal chamber even during tilting of the ladle, and means for discharging molten metal from the metal chamber upon tilting l*of .the ladle vessel.

7. A muie ladle of the character described comprising a substantially cylindrical refractorylined vessel, means for tilting said vessel through an arc about its axis, amolten metal chamber in the lower portion of said vessel `and a combustion chamber in the upper portion thereof,

a thin, substantially gas-tight heat-conducting wall separating said metal chamber fromrsaid combustion chamber but capable of receiving heat from within the combustion chamber and of transmitting radiant heat to metal in the metal chamber, means for burning fuel in' the combustion chamber, a refractory pipe open'at both ends extending from the outer surface ofthe .A ladle vessel through the combustion chamber and opening into the metal chamber, the open end of said pipe adjacent the outer surface of the ladle being atleast substantially as wide in the direction in which the ladle tilts as the` distance through which the ladle nmally tilts, whereby a.

from the metal chamber upon tilting of the ladle l vessel.

8. In a tiltable muiiie ladle having a molten metal chamber in the lower interior thereofand a heating chamber in the upper interior thereof with a wall therebetween, a conduit open at both ends extending from the upper exterior of said ladie through said combustion chamber and said Wall and opening into said metal chamber, whereby a continuous stream of molten metal may be poured from above the ladle directly into the metal chamber even during tilting of the ladle.

9. A tiltable mue ladle having a molten metal chamber in the lower interior thereof and a heating chamber in the upper interior thereof with a wall therebetween, and a conduit extending from the upper exterior of said ladle through said combustion chamber and said wall and opening into the interior of the metal chamber, the exterior of said ladle being curved uniformly adjacent said conduit so as to mate with a correspondingly curved end structure of a launder, and the extent and shape of said ladle curvature being such as to permit tilting oi the ladle relatively to the launder end structure without creating any substantial aperture therebetween.

10. A tiltable munie ladle having a molten metal chamber in the lower interior thereof and a heating Ichamber in the upper interior thereof with a wall therebetween, and a conduit extending from the upper exterior of said ladle through said combustion chamber and said wall and opening into the interior of the metal chamber, the exterior lof said ladle being curved uniformly adjacent said conduit so as to mate with a correspondingly curved end structure of a launder, Ithe extent and shape of said ladle curvature being such as to permit tilting of the ladle relatively to the launder end structure without creating any substantial aperture therebetween, and the mouth of said conduit adjacent the exterior of the ladle being sufciently large to receive a continuous flow of metal from the launder during normal tilting of the ladle.

ll. The combination with a launder for molten metal having a curved under-surface adjacent its discharge end, of a tiltable ladle having a corresponding curved upper-surface substantially mating with said launder under-surface, said ladle having a metal-receiving passage opening to the curved upper exterior thereof, the mouth of said passage at the exterior of the ladle being sufficiently large to receive a continuous flow of metal from the launder during normal tilting of the ladle.` l

12. The combination with a launder for molten metal having a curved under-surface adjacentl its ldischarge end, of a tiltable ladle'having a corresponding curved upper-surface substantially mating with said launder under-surface, said ladle having a metal-receiving passage opening to' adjacentits discharge end, of a. tiltable muiiie continuous'stream of molten metal maybepoured from above the ladle vessel directly into the metal chamber even during tilting'v of the ladle, and a spout through which molten metal may be poured ladle having a curvedupper-surface substantially mating with said launder undersurface, said ladle having a molten metal chamber in the lower interior thereof and a heating chamber in the upper interior thereof with a substantially gas-tight wall therebetween, and a conduit extending from the curved upper-surface of the ladle through said heating chamber and wall and opening into the molten metal chamber, the

mouth of said conduit at the upper-surface of the ladle being substantially directly beneath the discharge end of the launder and being sumciently wide to receive a continuous stream of molten metal during normal tilting of the ladle, and the curvatures of the launder under-surface and the mating ladle upper-surface being such as to permit normal tilting of the ladle without creating any substantial aperture therebetween, whereby molten metal may be poured continuously lfrom the llaunder through the conduit into the ladle metal chamber without coming in contact with deleterious gases either in the atmosphere or in the heating chamber.

14. An assembly of launder and pouring ladle for the casting of molten metal comprising an enclosed launder capable of conveying a stream of molten metal to its discharge end, a ladle arranged adjacent the metal dischargepoint of said launder in tiltable relation therewith and adapted to receive continuously during normal tilting movement thereof the stream of molten metal discharging from the launder, the arrangement of launder and ladle being such as to permit tilting of the ladle relatively to the launder without thereby permitting 'any substantial exposure of the stream of molten metal to the atmosphere. l

15. An assembly of launder and pouring ladle for the casting o! molten metal comprising an enclosed launder, a ladle arranged adjacent the metal discharge point of said launder in tiltable relation therewith, said ladle having a molten metal chamber in the lower 'portion thereof and a heating chamber in the upper portion thereof with a substantially gas-tight wall therebetween, and a conduit in said ladle extending from adjacent the discharge end of the launder through said heating chamber and wall and opening into metal chamber, the arrangement of ladle, and conduit being such as to the molten said launder,

v permit continuous flow of metal from the launder discharge into and through the conduit during tilting of the ladle, and further being such as to permit tilting o the ladle 4without thereby permitting any substantial exposure of the stream of molten metal to deleterious gases in the atmosphere cr in the ladle heating chamber.

16. A tiltable ladle having a molten metal chamber therein, and a spout through which molten metal may be poured from said chamber upon tilting of the ladle, the exterior surface-of said ladle in the vicinity oi.' the spout being curved uniformly adjacent said spout, in combination with a hood enclosing said spout, and means for introducing a protective gas into the interior of said hood, vthe hood at itsijuncture with the ladle being curved to conform with the aforesaid curvature of the ladle exterior surface, whereby the ladle may be tilted relatively to the the hood without creating any substantial aperture between the ladle and hood.

17.. A ti'ltable ladle having a molten metal chamber therein, and a spout through which molten metal may be poured from said chamber upon tilting of the ladle, the exterior surface of said ladle in the vicinity of the spout being curved substantially cylindrically through an arc having its axis substantially coincident with the axis about which the ladle tilts, in combination with a stationary hood enclosing said spout and the stream of metal issuing therefrom when the ladle is tilted to pouring position, and means for introducing a protective gas into the interior of said hood, the hood at its juncture with the ladle being curved to conform with the aforesaid curvature of the ladle exterior surface, whereby the ladle may be tilted relatively to the hood without creating any substantial aperture between the ladle and hood.

PHILIP M. HULME.

CERTIFICATE OF CORRECTION.

'Patent No. 2,529,0li9. September 7, 1915.'

PHILIP M. HULHE.

It is hereby certified that error appears in tne printed zunecificsxtior! of the above numbered patent requiring correction as follows: rage 5, secong column, line 50, claim 2, for the word "steam" read -stream; and l that the said Letters intent shold be read with this' correction thereinthat the same may confoim to the record of the cage in the Patent Office.

signed and sealed this 26th day of october, A. D. 191g.

Henry- Van Arsda1e,

(Seal) A cting Commissioner of Patents.

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