US3346038A - Continuous casting wheel, with improved cooling device - Google Patents

Description

|. PROPERZI CONTINUOUS CASTING WHEEL, WITH IMPROVED COOLING DEVICE Oct. 10, 1967 4 Sheets-Sheet 1 Filed July 2, 1964 INVENTOR. [lario Prop'erzi IQPROPERZI CONTINUOUS CASTING WHEEL, WITH IMPROVED COOLING DEVI CE Filed July 2, 1964 4 Sheets-Sheet 2 IIIII/I/IIIIIIIIIII.{VI/I INVENTOR. Ilario Properzj 0a. 10, 1967 f LP 3,346,038

CONTINUOUS CASTING WHEEL, WITH IMPROVED COOLING DEVICE I I Filed Jul 2, 1964 v 4- Sheets-Sheet 5 V F v ;MH=Y g 25 R VINVENTOR.

Ilario Properzi wewimw Filed July'z, 1964 Oct. 10, 19 67 PROP Y 3,346,038

CONTINUOUS CASTING'WHEEL, WITH IMPROVED COOLING DEVICE 4 Sheets-Sheet 4 INVENTOR.

Ilario Properzi m 6AM United States Patent Othce 3,34%,fi38 Patented Oct. 10, 1967 3,346,038 CONTINUOUS CASTING WHEEL, WITH IM- PROVED COOLING DEVICE llario Properzi, Via Cosimo do] Fante, 10, Milan, Italy Filed July 2, 1964, Ser. No. 379,353 Claims priority, application Italy, July 13, 1963, 14,686/ 63 7 Claims. (Cl. 164278) The present invention concerns an improved cooling device for a continuous casting wheel.

As is known, a continuous casting machine comprises a turning wheel provided with a circular peripheral groove, covered along a certain portion of are by a metal tape which closes the corresponding portion of the groove to retain therein the metal which, entering the groove in liquid state at the beginning of the closed portion, leaves it in the shape of a continuous solid bar or rod at the end of that portion. An important and delicate problem is the cooling of the molten metal in said groove and, therefore, of such metal parts of the wheel and tape at which come in contact with the molten metal.

In order that the bar or rod is solid by the time the molten metal reaches the end of the covered portion, it is necessary that adequate cooling take place while the wheel describes an angularmovement corresponding to said arc, usually'about one half revolution; on the other hand said wheel owing to requirements of production, has to perform such movement in a comparatively short time, whence it is necessary for the cooling to take place with a certain rapidity.

One of the most diflicult problems in this process of production is that of providing balanced cooling of the metal walls contacted by the liquid metal in a manner which permits the regular and uniform formation and crystallization of a peripheral solidification which takes place in the molten metal. The cooling efiiciency should be equivalent at the tape and within the cavity. The finished product will be unsatisfactory if one part of the periphery of the molten metal, in the course of solidification, cools more slowly than the remainder, thereby giving rise to misformations of crystallization, and also because in that zone the eutectics tend to localize which retards solidification and carries along such impurities as oxides and the like.

In addition to the attainment of said conditions of speedyand uniform cooling, the metallic ring which constitutes the periphery of the wheel should be made of small wall thickness, and at the same time it should permit an assembly with sturdy tightening at the massive spots of the wheel and an efiective support for the adhering tension of the tape besides the fatigue due to the thermal and dragging stresses etc.

The casting wheel according to the present invention,

comprising a grooved ring adapted to receive the liquid metal to be cooled and a metal tape in touch with the ring along an arc thereof, is essentially characterized in that for the cooling of said metal there is provided a device comprising means adapted to direct independently adjustable jets of water from the interior of the wheel against the wall of the grooved ring. The jets are to be ,so adjustable along the portion at which the tape is provided as to permit the most advantageous cooling of the molten metal from the direction of the ring wall in which the groove is provided. This cooling means further comprises means adapted to cool said molten material from the side of the tape also by adjustable jets of water, which strike said material.

These and other characteristics of the casting wheel according to the present invention, and the advantages coming therefrom, will be more fully illustrated in the following description, with reference to the accompanying drawing in which there is shown, merely by way of example without limitation, a continuous casting wheel with a cooling device according to said invention, wherein:

FIG. 1 shows a diagrammatic view, in elevation, of the casting machine;

FIG. 2 shows an axial section of the casting wheel;

I FIG. 3 shows an enlarged particular of an axial section of the casting wheel;

FIG. 4 shows a particular, in elevation, of the means for cooling from inside the wheel.

The casting wheel of the instant example, (FIG. 1) is identified with reference character R and comprises two parts 6 and 7 which are rigid with each other; the part '7 moreover is rigid with -a member 16 which in turn is rigid with a gear 17 meshing with a second gear, indicated at 18, which is fitted onto a shaft 19, the latter being arranged to be driven by a motor or engine.

The member 16 is integral with a hollow shaft 20 rotatable in the bearings 21 within a fixed sleeve 22.

The cooling device comprises, at the interior of the wheel, a series of radially arranged tubular elements 23, which are rigidly connected to a hollow element forming a central chamber 24 and in communication with the interior thereof (FIGS. 2 and 4). On each element 23 there is provided a nozzle 32.

There is further provided, near the periphery of the ring, a hollow annular element forming an annular chamber 25, and the tubular elements 23 are rigid with this also. The chamber 25 is divided, along the whole circumference, by a series of angularly spaced equidistant walls 26, into a series of chambers 25A-25H of equal angular width: each of said chambers is separated from the others, that is to say,'is not in communication therewith, by virtue of said walls; each tubular element 23 communicates with one of said chambers.

Said part 6 comprises an annular wall 27 provided with a series of holes 28 along its entire circumference, and each one of said chambers is provided with nozzles 29 which are carried by a radially outer wall of the respective chamber and are arranged to send water throughthe holes 28, as will be more fully explained herein-after.

A pipe 30 is rigid with a wall of chamber 24 and communicates with the interior thereof (see FIGURE 2); said pipe 30 is connected to a pump (not shown) adapted to send water under pressure into the chamber 24 and, therefore, through the pipes 23 into the nozzles 29. The arrangement comprising the pipe 30, the chamber 24, the pipes 23, the chambers 25A-25H, and the nozzles 29 is secured to the base of the machine.

The periphery of the wheel R is constituted by a grooved ring of copper or of another metal indicated by 1, and includes (FIG. 3), the groove 31 adapted to receive the liquid metal to be cooled. Groove 31 is bounded by a comparatively thin bottom wall 13 and the ring 1 comprises, laterally spaced from the groove 31, two side walls 4 and 5 of considerable thickness.

The Walls 4 and 5 are fixed to the massive steel parts 6 and 7 of the wheel by means of the tightening bolts 8 and 9 and the counter-washers 10 and 11.

A metal tape 12 is supported in tensioned condition on the peripheral faces of wheel R and an upper wheel 33, and overlies the groove 31 of ring along a portion of arc amounting to about 180, thereby covering up a corresponding portion of groove 31.

From a crucible 34, which position is adjustable, molten metal for the formation of the bar or rod is introduced into the groove 31 through a small pipe 35 which communicates with the groove near the beginning of the covered portion thereof.

The cooling device further comprises a pipe 36 which is divided into independent sections each of which corresponds to a certain sector of the wheel R, namely to a certain portion of arc of the grooved ring 1. Each section of the pipe 36 has water introduced thereinto, independently of the other sections, and is adapted to direct such water against the external surface S of the tape 12 located in front of the respective pipe section.

During the operation of the machine, the liquid metal (for instance copper) coming from the crucible 34 penetrates into the groove 31 through pipe 35. The wheel R is in rotation as indicated by the arrow F and so is the wheel 33 and the tape 12, which moves around wheels R and 33 according to the arrows F, continually keeps a portion of the groove 31 closed. The assembly comprising the pipe 30, the chamber 24, the pipes 23, the chambers A-25H, and the nozzles 29 is fixed. The liquid metal enters into the cavity constituted by the groove and tape, from which it cannot escape owing to the presence of the tape, and evidently the liquid metal assumes the shape of said cavity.

The cooling of the liquid metal is realized along a path confined between the beginning and the end of said cavity, the end being indicated at P in FIG. 1.

Said cooling is carried out by wetting the surface S of the tape 12 and the wall 13- of the groove with water in such a way that the metallic mass filling the groove cools down with substantial uniformity at the side adjacent the tape 12 and at the side adjacent the wall 13 opposite the tape.

The cooling from the side of the wall 13, namely from the interior of the wheel, is carried out through the above described device comprising the pipes 23, the various chambers 25A-25H, and the nozzles 29.

Through the pipe 3t) the water passes at considerable pressure into the central chamber 24 and from there through the pipes 25 into the respective chambers 25a 25H. Along the portion of arc defined between said point of entrance of the liquid metal into the peripheral cavity of the wheel and the outlet point P, the group of nozzles 29 of each chamber 25A25H directs jets of water through the holes 28 so that they strike successive portions of wall 13 corresponding to the length of the respective chamher.

It is clear that the jets coming from the groups of nozzles of the various chambers 25A25H may be adjusted, independently of one another, through the respective nozzles 32; hence it is possible to vary the intensity of the jets of water coming from the various chambers to obtain along the whole portion of are between the inlet of the liquid metal and the outlet, the optimum conditions for cooling of the molten metal from the direction of the wall 13. The jets coming from the various sectors of the pipe 36 and directed at the tape 12, are also adjusted to obtain the best cooling of the molten metal from the direction of said tape. It should be noted that the tape 12 is comparatively thin, since the said tape should be flexible, whence the dispersion of heat through said tape takes place with a certain facility. To obtain a similarly gOod heat dispersion through the bottom wall 1. 13 of groove 31, this wall 13 is also comparatively thin (FIG. 3).

Thanks to the limited thickness of said wall 13 and to the adjustable action of the jets of Water striking said wall, together with the action of the jets of the pipe 36 upon said tape 12, rapid and perfectly regular cooling of the metal placed in the groove 31 is obtained. Thereby one obtains at said point P a solid bar or rod 37 which is quite regular. The speed at which said bar or rod is produced is also notable. The limited thickness of the wall 13 notwithstanding, the grooved ring affords good conditions of strength and durability thanks to the sturdy walls 4 and 5 which permit a strong tightening of the ring at its connection to the parts 6 and 7 of the Wheel and the ring itself can stand the various stresses to which it is subjected, such as adherence tension of the tape, thermal stresses, dragging stresses, and so on.

It should be noted that the cross-section of the groove 13 shown in FIGURE 2 is diflerent from that shown in FIGURE 3 to illustrate one possible variation in this shape. Otherwise, FIGURES 2 and .3 correspond to each other.

I claim:

1. A continuous casing arrangement comprising, in combination, a circular rotatable casting Wheel having a circumferential wall and an outwardly directed circumferential edge face thereon; a circumferential groove provided in said edge face and having a bottom wall of a predetermined thickness and thermal conductivity; a metal tape extending partly around said edge face and covering said groove over a portion of arc, defining therewith a casting cavity adapted to receive a molten metal, said metal tape having a thickness so related to said predetermined thickness as to afford said metal tape a thermal conductivity substantially equal to that of said bottom wall; and cooling means, comprising first means for directly cooling said tape in the region of said portion of arc, and individually adjustable second means cooperating with said bottom wall for directly cooling the same, said second means comprising a plurality of angularly displaced discrete chambers provided in said circumferential wall inwardly of said bottom wall and each adapted to receive a cooilng fluid, and separate conduit means connected to each of said plurality of angularly displaced discrete chambers for admitting to each of said chambers cooling fluid.

2. A casting arrangement as defined in claim 1, wherein said separate conduit means include nozzle means communicating with the respective chambers and arranged to spray said cooling fluid against a section of said bottom wall associated with the respective chamber.

3. A casting arrangement as defined in claim 1, wherein said plurality of angularly spaced discrete chambers are distributed about the entire circumference of said wheel.

4. A casting arrangement as defined in claim 2, wherein said casting wheel comprises a circular supporting member having a radial supporting face, and an annular member surrounding said supporting member coaxially therewith, said edge face being provided on said annular member and said chambers being provided intermediate said supporting face and said annular member.

5. A casting arrangement as defined in claim 4, wherein said annular member comprises a pair of axially spaced flanges located at opposite sides of said bottom Wall of said groove provided in said annular member and extending radially inwardly, said flanges beingsecured to said supporting member; and two axially spaced further flanges extending radially outwardly from said supporting face adjacent to the respective flanges of said annular member and rigid therewith.

6. A casting arrangement as defined in claim 1, wherein said groove further comprises a pair of side walls extending from said bottom wall toward said edge face and having a thickness substantially corresponding to said given thickness of said bottom wall.

5 6 7. A casting arrangement as defined in claim 1, Where- 2,947,075 8/1960 Schneckenburger et al. in said predetermined thickness corresponds to at most X twice h thickness f Said tape 3,279,000 10/ 1966 Cofer et a1. 164277 FOREIGN PATENTS References Clted 5 764,193 12/1956 Great Britain. UNITED STATES PATENTS 861,273 2/1961 Great Britain.

944,370 12/1909 Monnot 164-70 1. SPENCER OVERHOLSER, Primary Examiner.

2,206,930 7/1940 Webster 164-1 55 R. S, ANNEAR, Assistant Examiner.

Claims (1)

1. A CONTINUOUS CASING ARRANGEMENT COMPRISING, IN COMBINATION, A CIRCULAR ROTATABLE CASTING WHEEL HAVING A CIRCUMFERENTIAL WALL AND AN OUTWARDLY DIRECTED CIRCUMFERENTIAL EDGE FACE THEREON; A CIRCUMFERENTIAL GROOVE PROVIDED IN SAID EDGE FACE AND HAVING A BOTTOM WALL OF A PREDETERMINED THICKNESS AND THERMAL CONDUCTIVITY; A METAL TAPE EXTENDING PARTLY AROUND SAID EDGE FACE AND COVERING SAID GROOVE OVER A PORTION OF ARC, DEFINING THEREWITH A CASTING CAVITY ADAPTED TO RECEIVE A MOLTEN METAL, SAID METAL TAPE HAVING A THICKNESS SO RELATED TO SAID PREDETERMINED THICKNESS AS TO AFFORD SAID METAL TAPE A THERMAL CONDUCTIVITY SUBSTANTIALLY EQUAL TO THAT OF SAID BOTTOM WALL; AND COOLING MEANS, COMPRISING FIRST MEANS FOR DIRECTLY COOLING SAID TAPE IN THE REGION OF SAID PORTION OF ARC, AND INDIVIDUALLY ADJUSTABLE SECOND MEANS COOPERATING WITH SAID BOTTOM WALL FOR DIRECTLY COOLING THE SAME, SAID SECOND MEANS COMPRISING A PLURALITY OF ANGULARLY DISPLACED DISCRETECHAMBERS PROVIDED IN SAID CIRCUMFERENTIAL WALL INWARDLY OF SAID BOTTOM WALL AND EACH ADAPTED TO RECEIVE A COOLING FLUID, AND SEPARATE CONDUIT MEANS CONNECTED TO EACH OF SAID PLURALITY OF ANGULARLY DISPLACED DISCRETE CHAMBER FOR ADMITTING TO EACH OF SAID CHAMBERS COOLING FLUID.

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