US1414394A - Apparatus for casting ingots - Google Patents

Description

G. BATTY.

APPARATUS FOR CASTING INGOTS.

APPLICATION man MAY n. 1920.

1,414,894. Patented May 2, 1922., v 3 SHEETSSHEET 3.

'enoaern BATTY, oriyor tx, EN LAND;

ArrAnArus son oi srrne 'meors. r

ingof ingots with the use of a base plate and channeled runner--br1cks,the base plate is recessed to receive the bricks and a central distribution-brick is'used also having channels communicating with those of the runner bricks, saidbase plates being designed for casting various numbers of ingots from a singleeentral feeding trumpet located over the distributor-brick. In the operation of such method the moulds are placed over holes in the runner bricks disposed centrally to the base of the moulds and the metal is discharged down the; trumpet and thence through the. distributor-brick and runner-bricks into the moulds This operation is known as bottom castin'g and is connnonly practised where a large number of .ingots are to be produced from one cast.

The present invention however provides a method in which certain disadvantages,

hereinafter mentioned inherent to the opera tion of casting down a trumpet are elim inated, and accordingly insteadof casting down the trumpet and through a distributor brick and runner bricks as described above,

themetal is cast down a mould placed cen-- trally to a number of other moulds of equal cross sectional area, say four, eight or twelve of such moulds. The base plate differs in design for each number of ingots required to be cast on each plate.

The invention also provides meansfor re ducing the amount of ingot discarded due to plpe or pocket for wh1ch purpose I provide refractory feeder heads or dozzles whlch are heated and placed in the outer moulds during the casting-operation; Thecasting down the central mould continues until the metal reaches a certain level in the dozzles the function of which is to maintain the metal:

in a fluid condition sufliciently long to avoid all cavity 1n the ingotdue to contraction.

.The central mould may also be provided with such a dozzle which 1s inserted 1m-' mediately the dozzles of the outermoulds are fully charged.

Application filed May 11,1920. Serial No.-*380,624.

mounted thereon and dozzles Specification of 'LettersPatent. Patented May-'2Q 1922 In a modification of the method adapted for use withcertain grades of steel the dozzles'of the outer moulds are replaced by solid 7 -metal stoppers adaptedto be held in a predetermined position in the moulds and with whichthe metal comes in contact during the casting operation causing the metal to freeze over and solidify at the'surface The castmg in the central'mou'ld is continued at a reduced speed until the metal therein reaches a level higher than thejstoppered surface of the ingots in the outer moulds a heated'dozzle being then inserted in the centralmould and filled with metal. The greater volume of metal in .the central mould enables contraction cavities in the outer mould ingots to be eliminated and constitutes a means by which the central mould.

In order that the method may be applied to the production of large ingots I have also devised a special form ofstopper which-will the outer ingots are fed .under pressure from l yield better results than would be" the case j than if the solid metal stoppers above referredtowere used. Such a stopper comprises a frame of cast steel or cast iron containing brieksof silicaor other refractory material suitably recessed, the wholebeing carried by means such as a rod pierced with holes at different levels to admit of stop'pering off the ingots at various desired lengths;

Embodiments of apparatus for carrying out the invention are illustrated in the accompanying drawings wherein Fig. l'is a Vertiealsection showing a'base plate with a central and two outer moulds heads applied to all the moulds.

Fig. 2 is a top planfiview of base plate detached for the casting-of nine ingots.

Fig. 3 is a viewsimilar to Fig. 1 showing outer moulds and p c i Fig. 4 is a detail sectional view'of a special formof dozzle? Figs. 5 to 13 are variousdetail views of the stoppers above-mentioned applied to the or feeder the composite metal and refractory stopper above referred to. Figs. 5 to 9 illustratingthe metal frame and Figs. '10 to '13 the refractory'brieks.

Taking as examplefan eight-way base plate a for producing nine ingots as-illus 'tratedin Fig.2, eight channels 6 are form'ed" in said basefplate to: receive the channeled runner-bricks c, said channels I) communieating with'thecentral recess d into which is inserted a' plate of steel 6 to prevent the erosion of the base. plate by the hot metal. The said central plate 6 is cast of metal similar in composition to that of the ingot to be produced and is held in the recess by the runner-bricks c which all slightly overlap the aforesaid central recess as indicated at f. The central mould g is mounted above the plate 6 and the outer moulds h each one above the outer ends of the runner bricks c with which they communicate.

When in position as described the runner-bricks form an octagonal recess 03 the diameter of which must not be greater than the diameter of the central or feeder mould g-above referred to. The moulds are placed in position and the metal is cast downthe feeder mould whence it flows through the runner bricks 1nto each of the other moulds this arrangement resulting 111 one 1ngot being top-cast, the metal entering from above and the remainder being bottom-cast as the metal enters at the base of the mould- The means for reducing the amount of ingot discarded due to pipe or pocket comprises refractory feeder heads or dozzles i of roughly rectangular section with a circular hole j and'having enlarged upper outer diameter as at i to produce a collar or overhang These dozzles are heated in any suitable furnace near the casting pit and are placed on the outer moulds 71- during the operation of casting. The lower part of the dozzle is inserted into the top of the mould as indicated, in Fig. 1 but is prevented from slipping down by the overhung portion 4,

" and on each dozzle there may be placed a small weight such as of bar scrap, serving to prevent it from floating up when reached by the metal. The casting down the central mould continues until the level of metal in the dozzles on outer moulds it reaches approximately the line k-just below the enlarged or overhung portion and the function of the dozzles is to maintain the metal in a fluid condition sufficiently long to obviate all cavity due to contraction. The central mould g may also be provided with a heated dozzle Z which is inserted immediately after the'dozzles of the router moulds are fully charged andis filled to about the level m whereupon the same level will be attained in the outer dozzles i.

The provision of such dozzles will effect great economy in the production of electrical-ly melted steel and high grade Siemens.

steel as it is unnecessary in these cases to discard any of the upper part of the ingot to dispose of deleterious non-metallic inclusions. With proper casting temperature and speeds with such steels, ingots up to fourteen by fourteen inches cross sectional area may be cast without. serious major segregation occurring.

In a modification of the method above de- In this'modification there are appliedto the upper ends of the outer moulds h the stoppers n as of cast iron carried by rods or the like ohaving holes 39 at determined distances alongsame. The said stoppers, which as shown are almost equal in area to the cross section of the mould are held in a predetermined position in the mould by passing a bar through one of the holes 3'9,

the bar seated on thectop of the mould, or-

other means for adjustably positioning the stoppers may be used. The casting proceeds down the central mould 9 until the metal. in

the outer moulds it has risen just'into con-V tact with the stoppers, whereupon said stoppers immediately cause the cast metalto freeze over and solidify at the surface. The casting in the central mould is then continued at a reduced speed until the metal in the said central mould has attained alevel.

several inches higher than the stoppered surface of the ingots in the outer moulds. Into the central mould is then inserted a hot feeder head or dozzle 9 which is filled with metal, the object of the greater volume of metal in the central mould (at a higher level than the metal in the outer moulds) being to eliminate contraction cavities within the ingots in the outer moulds. The method also actually effects the feeding of the outer ingots under pressure from the central ingot. The runner bricks 0 are preferably oflarger bore than previously specified for this method. I

As aforesaid this modification in the casting method is applied to certain steels, whereas other steels will be provided with hot feeder heads or dozzles for each ingot as referred to in the method described with reference to Fig. .L.

In Fig. 4 there is illustrated a further modification somewhat different to that last described in that the stoppers nare replaced by a heated feeder head or dozzle a" of the particular form shown having a recessed bottom 'anda central vent o from said cavity to the exterior. The same principle of feeding at the bottom from superimposed metal in the central mould is used as in the method described with reference to Fig. 3 but the hot feeder head renders the feeding more certain. This feeder head is held in position in the outer mould 71 by means of a steel rod 3 loosely inserted into an aperturei; in the head and astopper u or other weight is placed on the head to prevent the head from floating up on the metal in the mould.

In the casting operation, when the metal has filled the major cavity in the hot feeder head 1' the Vent o is closed by means of the stopper u and casting into the central mould without stopping proceeds until a level several inches above the line m-:c is attained.

To now refer to the further form of stop per illustrated in Figs. 5 to 13, such a stopper as aforesaid is adapted'for use'when producing large ingots. The frame of cast iron or cast steel is shown at A and A in Figs. 5 'and'6 in plan View and section respectively and in similar views in Figs. 3, 7 and, S at right angles to Figs. 5-and 6. Allthese Figures 5 to 8 show the shape of frame designed to receive the bricks of silica or other refractory material shown in Figs. 10 to 13 and also indicate the provisionof lugs F F positioned on opposite sides of the frame. Fig. 9 showsthe stopper assembled for use, H designating the stopper rod provided with the series of holes 11 and provided with legs H H which loosely fit the lugs F F on the frame. In Figs. 10 and- 11, D D and E E show the silica bricks provided with recesses D and E respectively.

Three or more of such bricks are usedwith each stopper to form a head substantially hemispherical in shape below, and placed at the top of the ingot in the outer moulds. V For the central mould, when making large ingots an ordinary feeder head may be used instead of a heater feeder head.

' duced so that the metal may flow from the central to the outer ingots during solidification. In producing large ingots it would be impossible to manipulate heated feeder heads and it is therefore intended to use the composite stopper" of steel and refractory material on the outer moulds and to have metal superimposed in the central mould and an'ordinary or brick lined head on said central mould.

Advantages of the methods above are as .follows: I

The weight of metal in the centre or feeder mould is always slightly in excess of the weight in any other mould of the group, whereby back-pressure is overcome and the metal rises evenly in each of the outer moulds under the constant slight excess in the central mould. Liquid steel will, of course, find its own level in common with other liquids, but it is must be borne in mind that the metal described in the outer moulds is cooler, more viscous,-

' when the cooling of the upper metal in the moulds generates sufficient backpressure to prevent, any'hot metal entering the 'm ould at the bottom; This often occurs and prevents the'production of ingotsof requisite weight: also "it frequently occurs that ingots-of uneven weight are produced from a .clustei and this raisesmanifold difficulties of pro- The "scrap produced by the improved method is less than that produced bytrumpet casting as the 'metal' remaining. in :the

trumpet is always'scrap.

- The-metal rises evenly and equallyin all moulds notwithstanding that some may be placed further from the central mould than.

others. This is a function .offbalanced pressures which isabse ntwhen trumpet cast mg 51s used.

Costs are'reducecb'as the expensivepipes and tundish for the trumpet are} abolished. The reduction of scrap is also a factorof costs.

Other advantages derived from the methods of the present invention are that lcasting may take place at a lower temperature, thereby conferring superior physical qualities upon steel; that the product of sound material from the ingots is verymuchf greater than is the case with the present methods of ingot production; that the ingots produced by the methods are free from surface and subcutaneous defects owing to the very even and regular rise of metal in the moulds, as compared with the surging, which almost invariably occurs in the moulds when trumpet casting is used: that, owing to the casting taking place at a lower temperature, the deleterious segregations are greatly minimized in the ingots and that as com-.

particularly in the case of Tungsten steels,

pared with the present system of casting,

as well as to the electric, the Bessemer, and

the open hearth products a steel of much greater homogeneity is obtained. By the adoption of this method by crucible steel makers the incidental variations of compo- I sition due to the complex reactions in the crucible'are' averaged by the mixing of the contents of twelve ormore crucibles in a ladle, and'casting the whole of these simul-' taneously in aset of moulds. y

WVhat I claim as my invention and desire to secure by Letters Patent of the United States is: H r I p 1. An apparatus for casting metal ingots comprising abaseplate having a central recess, channelled runner bricks radiating from said recess, a central mould disposed above said recess and outer moulds disposed above and communicating from below with the outer ends of each of saidrunner bricks whereby the number of ingots produced is in accordance with the number of outer moulds plus that in the central mould, and metal stoppers adapted for insertion into the outer moulds at predetermined distances and to substantially fill the cross sectional area of said moulds, said stoppers each, comprising a metal frame and a plurality of sections of bricks carried thereby, said brick sections being of refractory material and recessed on their under surfaces, the recesses When the sections are assembled in the frame forming a substantially hemispherical lower surface. s

2. An apparatus for casting metal ingots comprising a base plate having a central recess, channelled runner bricks radiating from said recess, a central mould disposed above saidrecess and outer moulds disposed above and communicating from below with the outer ends ofeach of said runner bricks whereby the number of ingots produced is in accordance with the number of outer moulds plus that. in the central mould, and metal stoppers adapted for insertion into the outer moulds at predetermined distances and to substantially fill the cross sectional area of said moulds, said stoppers each comprising ametal frame and bricks of refractory material carried thereby, lugs formed on the frame, a handle detachably connected to the lugs, said handle having vertically spaced perforations therein, and pins adapted for insertion through the perforations, said pins engaging the upper surfaces of the moulds for limiting the distance of insertion of the stoppers. v 7

In witness whereof I have signed this specification in the presence of tWo itnesses. 1

- GEO. BATTY, Witnesses:

HENRY LECINBY Coornn, E. 'MABE 'HODGKINSON.

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