US1553849A - Method and apparatus for casting ingots - Google Patents

Description

Sept. 15, I925.

' R. G. COATES .uz'mon AND APPARATUS FOR CASTING INGOTS Filed Aug. 17. 19 5 3 She'ets-Sheet 1 lllll. I 1 I I l l l I I l I.V

M ATTORNEY Sept. 15. 1925.

I R. G. COATES METHOD AND APPARAgTUS FOR CASTING INGOTS Filed Aug. 17. 1923 3 Sheets-Sheet 2 INVENTOR flay 6'. 'aafes 2B 2 ATTORNEY Sept. 15. 1925.

' R. G. COATES METHOD AND APPARATUS FOR CASTING INGOTS flied Aug- 17. 192: s Shets-Sheet I I J| INVENTOR [fay Q. BY

M ATTORNEY Patented .Sept. 15, 1925.

UNITED STATES PATENT OFFICE.

RAY G. COATES, OF PASADENA, CALIFORNIA, ASSIGNOR TO VALLEY MOULD AND IRON CORPORATION, OF SHARPSVILLE, PENNSYLVANIA, A CORPORATION 0'! NEW YORK.

METHOD AND APPARATUS FOR CASTING INGOTS.

Application filed August 17, 1928. Serial No. 657,855.

To all whom it may concern.-

Be it known that I, RAY G. COATES, a citizen of the United States, residing at Pasadena, in the county of Los Angeles, State of California, have invented certain new and useful Improvements in Methods and Apparatus for Casting Ingots, of which the following is a specification.

The present invention relatesto metallurgy, and more particularly to a method and apparatus for casting top poured steel ingots.

Heretofore in the art it has been customary to cast top poured ingots one at a time. There have been methods proposed where several such molds may be simultaneously filled from the same ladle, but such prior art methods required the mechanical division of the main stream of molten metal from the ladle into streams of smaller crosssection, which would be run a relatively short time. Under these conditions only a relatively few number of molds may be simultaneously poured.

In the modern production of steel, the charges are usually poured into ladles which will hold from fifty to'one hundred tons of molten steel. The length of time of pouring from the ladle is controlled by the period that the steel in the ladle will remain molten, and, therefore, it must in any case be discharged before it freezes in the ladle.

Where a number of ingot molds are set up for casting, as is common in the art, it is customary to move the ladle from one mold to another or to move the molds past the pouring station by means of a train of cars on which the molds are carried. Since the time for discharging the ladle is fixed, and since the molds must be filled either individually or in small groups, the ingots last cast will be cast from colder metal than those first cast, and the time-of casting per individual ingot is short as compared to the:

freeze from the bottom upwardly, and a shallow pool of molten metal may be carried above the freezing steel. On the other hand, where the steel is poured'rapidly, the high velocity of the incoming steel causes a forced circulation which delays bottom freezing,- and the mold is filled so quickly that freezing occurs over the sides and bottom simultaneously. Under these conditions, contractional cavities form, and pipes occur. It will be observed that the desirable procedure is to very slowly pour top poured ingots, but heretofore this has not been practical, since such a procedure would have increased the time period for the total pouring beyond the time when the metal in the ladle would freeze, and beyond the time allowed for other operations in the cycle of steel production. The present invention overcomes the difii-' .culties of the known art by providing a method and apparatus by means of which a large number of molds may each be simul-' taneously fed by small streams over a long period of time, and without delaying or increasing the period of ladle discharge. The filling operation occurs substantially simultaneously for each mold, and the time factor for filling each mold may be equal to that which would be required to fill a series of such molds of the same number if they were individually filled. in series by old methods. Heretofore, in attempts to divide the white hot stream of metal in cross-section, it has been very difficult to maintain the size of the stream of such cross-section as to secure the best results. y

In the present method a constant stream, of metal is allowed to run from the nozzle of the ladle, and this entire stream is delivered intermittently to each of a series of conductors leading to the various moulds, the

selves. Thus, instead of attempting to 'divide the stream of metal cross-sectionally, the flow-has in one sense been dlvided longitudinally. Since the longitudinal dimen-F sion of the flow is very great as com-pared' with its cross-sectional dimension, the diviv sion of the flow into relatively. easy.

a series of parts is According to the present invention, the

molds may be set in a circle on bottom plates or stools, which are the equivalents of those now used in top casting. One bottom plate may be used for each mold, or several molds may be set on one bottom plate, or, in an extreme case, all of the molds may be set on one bottom plate. The molds may be of the usual kind, open at the top and bottom, and have the usual draught to facilitate stripping. This me'ansthat in the present invention the molds themselves reing accomplished by increasing the thickness of the refractory material Where such divisions are desired, yet the finished height of the division is less than the full inner depth of the trough in order that the trough may act as a whole above the upper limit of the divisions. A receiver is provided for each mold, and is so formed that it will drain to one point and at this point an orifice is made large enough to keep open against freezing so long as fluid metal is supplied to the receiver. This orifice discharges fluid metal smoothly into the mold.

Concentric. with this ring ofreceivers is a rotary member which turns around a vertical axis. On this rotary member is arranged a distributor in a radial position, the central end of which is formed into a fountain, while the other end reaches to the central line of the circle. of receivers.

The outer end of this distributor is turned backwards from the direction of its motion.

gear, or its equivalent, is attached to the distributor with connections to a suitable motive power so that it may be continuous- 1y rotated during the time of pouring the steel from the ladle. The distributor may be an open trough, or it may comprise a closed runner between the fountain and the outer end if, for any reason, this becomes desirable.

The ring of receivers and the distributor with its rotating central axis and the support ofthe latter, to ether with the motor and connections to drive the distributor, form an integral structure that can be placed over he molds either byan over-head crane, or by being moved out by some other means, as for instance, by a car system on a suitable track. Themolds themselves may be on cars and either the run under the above structure or the latter may be moved over the cars in any approved manner.

The principal object of the present invention is the method and apparatus for casting ingots whereby a continuousstream of molten steel is passed in regular sequence over and into a series of on-chilling receivers, each of which disc arges into an individual mold.

Another object of this invention is the method and apparatus for casting steel ingots by passing the discharge stream from a suitable source over mold feeding receiv ers in such manner as to maintain superimposed layers of fresh steel in the receivers until the molds are filled.

A still further object of the present invention is the method and apparatus for casting steel ingots which comprises sub-.

to form super-imposed layers of fresh steelto receivers for feeding individual molds, whereby the pouring time of each ingot is slightly longer than the discharge period for the ladle. v

A still further objeet-of the present invention is the method and apparatus for slow pouring of top poured ingots com rising a series of molds arranged in a circ e to befed simultaneousl from a single source, supplying a movab e distributor in such manner that the stream of molten steel from the distributor is successively discharged into a circular series of feeders, one for each individual mold, whereby each mold receives a portion of the source stream during the entire flow of such stream.

Other and further objects of this invention will in part be obvious and will in part be pointed out hereinafter by reference to the accompanying drawings forming a part of this specification.

It is realized that the present invention may be carried out in other ways and by other mechanisms without departing from the scope of the inventionQand, therefore, it is desired that the present disclosure shall be understood as illustrative and not in the limiting sense.

-Referring now to the drawings, throughout which like parts are represented by like characters.

Figure 1 is an elevational view of a more or. less diagrammatic illustration of one form of apparatus embodying and for carrying out the present invention;

Figure 2 is a plan view of the device shown inFigure 1; a

Figure 3 is a section through a portion of the distributor;

tion.

Figure 4 is a detail view through a portion of a receiver and mold;

Figures 5, 6, and 7, illustrate variations in mold set ups according to the present invention.

The embodiment of the invention as shown in Figures 1 to 4 inclusive comprises a series of ingot molds 1 arranged in a circle upon a casting floor 2, as an endless series. These molds are set between track rails 4, which may be arranged either as a floor, or an over-head track, and which support a carriage 5. This carriage carries a trough member 6, which comprises a supporting shell 7 in which is mounted a refractory lining 8 that is divided into receivers or pockets 9 by division walls 10. These division walls 10 are not as high as the side walls of the trough formed by the refractory lining 8 so that molten metal may fill the trough over the said division walls 10. The lowest portion of each receiver is provided with a discharge opening 11 arranged to be directly over an ingot mold 1 so that there are as many receivers as there are molds to be filled.

A spider frame 12 extends toward the center of the circular trough 6 and carries a supporting bearing 14 in which is mounted a vertical shaft 15 that carries a distributor 16 which is also formed of an open trough-like shell that is lined with refractory material. This trough preferably terminates at the inner end in a fountain basin 17 that is directly over the shaft 15, and at the outer end is a curved end 18 which extends directly over the trough 6" and is adapted to discharge molten metal from the distributor into the receivin trough 6. The distributor is eounter weig ted as at 19 to balance the weight of the distributor and contents when the device is in opera- The lower end of the shaft 15 carries a gear 20 that meshes with a pinion 21 on a. power shaft 22 that may be driven by an electric motor 24. This motor 24 is adapted to be controlled by an operator on the control platform 25. The car 5' may moved by suitable clutch controlled connections with the motor 24 "or by any other means suitable for the purpose, to position the receiver trough over the mold set-up.

Figures 5, 6, and 7 show the receiver trough provided with trough arms 26 which are adapted tolead themolten metal from. the circular receiver trough into molds set in straight rows or in rectan ular groups.

During the operation of casting the" above described receiver trough and distributor remains over the molds and each receiver dischar s into a particular mold. It will be inner fountain end will remain in the same place while its outer end will sweep over the entire line'of receivers once in each revolution. If now a ladle 27 of molten steel is brought by an overhead crane, in the usual way, to a position such that the nozzle of the ladle is central with the fountain of the distributor and this latter is set in rotation at the desired rate, then any steel discharged by the nozzle into the fountain will be delivered by the distributor into the receivers as the former sweeps over them.

The entire ladle can be thus discharged into molds without moving the ladle itself provided there are molds enough to hold the contents of the ladle. If the divisions which separate the receivers from each other are so placed that they intercept equal portions of the circumference described by the outer end of the distributor then the amount of metal falling into each receiver will be the same.

It will be evident that if the end of the distributor discharges the fluid steel in a direction tangential to its path of revolution at the point of discharge and that if the rate of rotation is such that this point of discharge has a velocity equal to the spouting velocity of the steel as it falls from the distributor then the steel itself will fall into the receivers without either radial or tangential velocity and any tendency to splash and scatter the metal will be eliminated while the metal will be well mixed It will also be evident that the spouting velocity of the metal may be largely controlled by the grade or incline given to the distributor between the fountain and its outer end. This fact. together with the consideration of the centrifugal force developed in the metal due to the speed of rotation, will enable practical conditions to be met. 7

The intermittent additions of metal to each receiver should be rapid enough to keep the contents of the receivers fluid during the operation of pouring. The sketches show the distributor as a single conductor with a mechanical counterbalance. This counterbalance may be simply another distributor receiving from the same fountain and discharging also into the receivers. Any irregularities in discharge between the distributors would have no ill effects because all distributors would discharge into all receivers.

The discharge orifice in the receivers should be under a very low average ferrostatic head so that a small actual increase in the head due to the charge delivered by the distributor will cause a large proportionate increase in head and a consequent rapid increase in flow through the orifice, as well as a rapid decrease as the head runs down so. that the flow of metal into the; mold itself will not be broken.

It will be noted that small variations in the size of the orifices of the various receivers will cause no change in the amount of the metal received by the molds, because such small variations in the size of the orifices simply cause more or less change in the head of metal over the orifice until the discharge has increased or decreased enough to counteract the variations.

By the above means the entire stream of metal flowing from a ladle may be evenly discharged into a large number of molds. If it is desired to discharge more metal into one mold than into others it is only necessary to arrange the position'of the divisions so as to intercept the required proportion of the path of the discharging end of the distributor.

In order to establish a pool of steel in the mold it is desirable to have a strong feed when the pouring is first started into the mold. It may be accomplished by employing a rather large nozzle for the ladle with the nozzle at first wide open and after the first few revolutions of the distributor, clos ing down the stopper to such a point as will use the desired time in the pouring.

Having thus described my invention, what I claim is:

1. The method of simultaneously pouring a. plurality of ingot molds, which method comprises providing a plurality of receivers having discharge openings leading to ingot molds, with the discharge openings of such size as to pass a volume of molten metal which is less than the volume of the main supply stream; and intermittently feeding the receivers from the main stream with suflicient rapidity and volume to maintain d a supply of molten metal in each receiver until its respective mold is properly filled.

2. The method of simultaneously pouring a plurality of ingot molds, which method comprisesproviding a plurality of connected receivers, each having a discharge opening leading to an ingot mold, with the discharge opening of such size as to pass a volume of-molten metal which is less than the volume of the main supply stream; and intermittently feeding the receivers from the main stream by a distributor movable over the receivers with sufiicient rapidity so as to maintain a supply of molten metal in each receiver imtil its respective mold is properly filled.

3. The method of simultaneously pouring a plurality of ingot molds, which method comprises providing a plurality of receivers having discharge openings leading to-ingot molds; and intermittently feeding the receivers from the main stream.

4. The method of simultaneously pouring a plurality of ingot molds, which method comprises arranging a plurality of receivers m an endless series, with each receiver adapted to feed an ingot mold; and discharging a main supply stream into the receivers to maintain a fresh supply of molten metal in said receivers until the molds are filled.-

5. The method of simultaneously pouring a plurality of ingot molds, which method comprises arranging a plurality of receivers in an endless series, with each receiver adapted to feed an ingot mold; and discharging a movable main supply stream into the receivers at a sufficient rate to maintain a fresh supply of mixed molten'metal in said receivers until the molds are filled. A 6. The method of simultaneously pouring a plurality of ingot molds, which method comprises arranging a plurality of ingot molds in an endless series, and discharging a main supply stream intermittently into each of said molds.

7. The method of simultaneously pouring a plurality of ingot molds, which method comprises dividing a main supply stream of molten steel transversely into a plurality of sections; superimposing later sections of said stream over earlier sections thereof, and feeding said superimposed sections to individual ingot molds.

8. The method of simultaneously pouring a plurality of ingot molds, which method comprises dividing a main supply stream of molten steel'transversely into a plurality of sections; superimposing later sections of said stream over earlier sections thereof to a cause a mixing of the metal thereof, and feeding said superimposed sections of the main stream to individual ingot molds over a period of time substantially equal to the ischarge period for the main stream.

9. The method of simultaneously pouring a plurality of ingot molds, which method comprises moving the discharge end of a main supply stream and dividing a main supply stream of molten steel transversely while moving into a plurality of sections; superimposing later sections of said stream over earlier sections thereof, and slowly feeding said superimposed sections to individual ingot molds.

10. The method'of top pouring plurality,

of ingot molds, which method.- comprises repeatedly passing a continuous stream of molten metal in regular sequence over and into an endless series of receivers, each of which latter discharges into a particular mold.

11: The method of top pouring a plurality of ingot molds, which method comprises repeatedly passing a continuous stream of molten metal in regular sequence over and into an endless series of receivers,'each of which latter discharges into a particular mold, the time of discharge from the receivers being substantially equal to the total time of discharge of the continuous stream.

12. The method of top pouring a plurality of ingot molds, which method comprises repeatedly passing a continuous stream of molten 'metal in. regular sequence over and into an endless series of ingot molds.

13. The method of top pouring a plurality of ingot molds, which method comprises moving a stream of molten steel over a supply station for each individual mold to feed each mold from successive portions of the molten stream during the entire period requiredto fill all of the said plurality of molds.

14. The method of top pouring a plurality of ingot molds, which method comprises intermittently moving a main stream of molten steel over a supply station for each individual mold to feed each mold from suc-. cessive portions of the main molten stream during the entire period required to fill all of the said plurality of molds.

15. The method of top pouring a plurality of ingot molds, which method comprises moving a stream of molten steel over a supply station for each individual mold to feed each mold from successive portions of the molten stream; and controlling the size of the streams to the individual molds to cause the filling period for each mold to "the form of a circle, with each receiver connected to an ingot mold; and discharging a movable main supply stream into the receivers with the rate of movement of the discharge end of the main stream being substantially equal to the rate of flow of the molten metal in the said main stream at the discharge end thereof.

18. The method of slow pouring top poured ingot molds, which method comprises dividing the main supply stream transversely into a plurality of sections and controlling the flow of the sectionalized portions to individual ingot molds so that the period of flow from the sectionalized portions to the molds is slightly greater than the total period of flow of the main supply a stream.

19. The method of slow pouring top poured ingot molds, which method comprises divlding the main supply stream transversely into a plurality of sections; superimposing later sections over earlier sections; and controlling the flow of the superimposed sectionalized portions to individual ingot molds so that the period of flow from the sectionalized portions to the molds is slightly greater than the total period of flow of the main supply stream.

20. The method of top pouring a steel ingot, which comprises slowly pouring a small stream of molten steel from a shallow pool directly into a vertical mold; intermittently replenishing the shallow pool with fresh hot steel during the pouring of an ingot; and rapidly chilling the accumulated metal in the mold to maintain a shallow layer of molten steel over the rapidly freezing lower metal.

21. The method of top pouring a steel ingot, which comprises pouring a continuous small stream into substantially the center of a vertical ingot mold, and preventing the freezing of the stream by intermittently adding fresh hot steel during the pouring of an ingot to the source of supply for said stream.

22. The method of discharging a ladle of molten steel and simultaneously casting a plurality of ingots from the ladle charge, comprising intermittently leading the ladle stream to the separate sources of a plurality of small independent mold feeding streams so that each mold feeding stream receives a portion of the first and also a portion of g the last of the ladle charge.

23. The method of discharging a ladle of molten steel and simultaneously casting a plurality of ingots from the ladle charge, comprising a continuous ladle'stream intermittently leading the ladle stream to each of a plurality of shallow pools comprising the sources of a plurality of small mold feeding streams so that each mold feeding stream receives a portion of the first and also a portion of the last of the ladle charge.

24. A device of the class described comprising a receiver for molten metal, said receiver being provided with. discharge means leading to an ingot mold, and a supply member movable over said receiver to intermittently supply said receiver with molten metal during the pouring of an ingot in said mold.

25; A device of the class described comprising a circular. receiver for molten metal, said receiver being provided with discharge means leading to an ingot mold, and a swinging supply member having one end movable over said receiver to intermittently supply said receiver with molten metal, the other end of said member being located substantially at the center of the circular receiver. V

'26. A device of the class described comprising in combination a trough divided mto a plurality of independent receivers,

each adapted to discharge into an ingot mold, a supply member adapted to travel common troug over said trough to supply molten metal to the receivers in said trough, and means to move said member.

27. A device of the class described comprising in combination a supporting frame, a trough mounted upon said supportmg frame and divided into a plurality of receivers, each adapted to discharge into an ingot mold, a supply member adapted to travel over said trough to supply molten metal to said trough, and means to move said member at a rate of travel equal to the flow of metal from said supply member.

28; A device of the class described comprising in combination a carriage, a recelver trough mountedon said carriage, conduits from said receiver trough leading to ingot molds, and a swinging supply member having a discharge end movable over said trough to distribute molten metal lengthwise of said trough, the other end of sald member being provided with a fountain basin adapted to. be located to receive a ladle stream.

29. A device of the class described comprising in combination a carriage, a supply member adapted to move over a plurality of ingot molds and supply molten met-a1 thereto, and means to move repeatedly said supply member over said molds while said carriage is stationary.

30. A device of the class described comprising in combination a receiver trough, a plurality of receivers in said trou h with the divisions between said receivers ing of less height than the sides of said trough, each receiver being adapted to feed an ingot mold, and means to supply molten metal to the receivers in said trough.

31. A device of the class described comprising in combination a curved receiver trough, a swing supply arm adapted to move over said trough, and means to move said supply arm.

A device of the class described comprising in combination a circular trough, conduits from said trough leading to ingot molds, and means to supply molten steel to said circular trough.

33. In the art of casting ingots, the combination of a Ipluralit mem er to ead molten metal to said molds and distributing means of ingot molds, av

constantly moving over said trough to supply molten metal to different portions of said trough at different times.

34. In the art of casting ingots, the combination of a common troug mem er to lead molten metal to said molds, a supply member movable lengthwise of said trough and being adapted to supply molten metal to said. trough, and means to move the discharge end of said supply member at the same rate of speed as the flow of the molten metal from said supply member.

. 35. The method of simultaneously pouring a plurality of ingot molds, which method comprises arranging a plurality of receivers in an endless series, with each receiver adapted to feed an ingot mold, and discharging a main supply stream from a moving distributer into the receivers at a suificient rate to maintain a fresh supply of mixed molten metal in said receivers until the molds are filled. I a

36.- The method of top pouring a plurality of ingot molds, which method comprises repeatedly passing a continuous stream of molten "metal in regular sequence over and into a series of molds.

37. The method ofv top pouring a plurality of ingot molds, which method comprises repeatedly pasing a continuous stream into a series of rece1vers, each of which receivers discharges into a particular mold.

38. The method of top pouring a steel ingot which comprises slowly pouring a small stream of molten metal from a receiver into a vertical mold, and intermittently replenishing the supply of steel in said receiver with fresh hot steel while said ingot is being poured.

39. A device of the class described comprising in combination a carriage, a receiver trou h mounted on said carriage, a plurality 0% receivers in said trough, said receivers having conduits leading to ingot molds, and a supply member movable lengthwise of said trough to distribute molten metal to said receivers.

RAY G. COATES.

pluralit of ingot molds, at

ingot molds during 1 the pouring of an ingot in each of said of molten metal in regular sequence over and v

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