US3278999A - Apparatus for continuous casting of metals - Google Patents

Description

Oct. 18, 1966 H. LEMPER ,9

APPARATUS FOR CONTINUQUS CASTING 0F METALS Filed Feb. 4, 1964 2 Sheets$heet 1 INVENTOR v @Herbert Lemper Oct. 18, 1966 H. LEMPER 3,278,999

APPARATUS FOR CONTINUOUS 'CASTING OF METALS Filed Feb. 4, 1964 2 Sheets-Sheet 2 Fig.4.

? HLTtYe r? 221 MW/ United States Patent 3,278,999 APPARATUS FOR CONTINUOUS CASTING 0F METALS Herbert Lemper, Pittsburgh, Pa., assignor to Mesta Machine Company, a corporation of Pennsylvania Filed Feb. 4, 1964, Ser. No. 342,374 4 Claims. (Cl. 2257.2)

This invention relates broadly to continuous casting machines and more particularly to a continuous casting machine that is disposed in a fully horizontal tin-line position.

Heretofore, continuous casting machines have for the most part been vertically disposed with a water-cooled flow-through mold having its cavity vertically aligned. Hot liquid metal is poured into a tundish at the top of the machine which feeds hot metal into the mold. The metal passes down through the water-cooled mold and is partially solidified in so doing. The metal slab emanating from the mold drops through a vertical cooling chamber, where the metal is further cooled and solidified. Continuing its vertically downward passage the metal slab passes through a withdrawal mechanism such as pinch rolls and a bending roll mechanism which turns the slab through a 90 arc to the horizontal, from there the slab advances through a straightening device and into a cutoif device where the slab, which is continuous of course, is cut ofi into billets of desired length. Vertical units such as just described require generally 75 ft. or higher roof clearance and about the same in length of floor space. They also require a great deal of supporting superstructure as well as catwalks and the like to attend the machine.

Recently, efforts to shorten and simplify these machines have resulted in the development of socalled horizontal continuous casting machines, which is a misnomer because in reality they are only partly horizontal. This improvement came about through the development of curved molds and cooling chambers which casts a curve into the slab and eliminates the need for the long straight drop in a cooling chamber and bending the slab to the horizontal for straightening and cut-off. This successfully cut the height of the machine to about one-third of what it was before, i.e., about 25 to 30 ft.; the length of the machine, however, remained about the same because of the slab straightening equipment still required.

A good description of the prior art outlined above has been published in the June 17, 1963, issue of Steel, The Metalworking Weekly, beginning at page 71 thereof.

One of the principal reasons why a fully horizontal machine has not been forthcoming is that in continuous casting machines it is necessary to oscillate the mold so that the slab being cast properly emanates from the mold without hanging up or sticking in the mold. This is a simple matter on vertically disposed molds as they are merely oscillated up and down to break the sides of the slab loose from the cavity walls of the mold. The tundish feeding the mold is generally stationary above the mold and the oscillating of the mold up and down presents no inconvenience or difiiculty in directing hot metal from the tundish into the mold, nor from the ladle into the tundish which, as mentioned, is standing still. However, a horizontally disposed mold presents a serious problem in this respect as the tundish must be sealed to the mold for proper horizontal feeding. Attempts to overcome this problem have been made by elongating the tundish so that it may be oscillated and still permit pouring into it from a non-oscillating ladle, however, the elongated tundish presents a larger area of exposed metal where undesirable preliminary cooling of the hot metal can take place. But, most of all, the oscillating of the tundish is undesirable because of the slopping created thereby.

I have discovered another and better way of causing oscillation to take place between the mold walls and the metal being cast in a truly horizontal machine and that is by oscillating the pinch roll withdrawal equipment and making the mold and tundish stationary with a sealed connection between them.

This permits an in-line fully horizontal casting machine that is commercially practicable with attendant advantages that are truly remarkable. The size of the machine is dramatically reduced. The height of a machine comparable to the earlier described vertical machines is only about 4 ft. and the length about 20 ft. A space 40 ft. long and 10 ft. high would be suflicient to accommodate pouring from a ladle (height) and cutting off billets of ordinary size (length); however, it is preferable to allow 60 ft. for length to permit billets of most any desired length to be cut oil, and too, to allow room for the starting or dummy bar to pay out in addition to the first billet being cut off. The savings in height is obviously accomplished by making the machine fully horizontal, while the savings in length is due to the total elimination of the bending and straightening mechanisms. There are also great savings in supporting structure and in the building itself formerly needed to house the machine which those skilled in the art will readily appreciate. It simplifies, too, the cooling aprons which now need only contain the slab initially adjacent the mold rather than through the entire cooling chamber as heretofore, the balance of my cooling aprons simply providing support and direction to the slab.

I provide a method for continuous casting of elongated metal bodies comprising the steps of casting hot liquified metal into tundish means having an aperture opening horizontally into a horizontally disposed cavity of a Water-cooled flow-through mold, there being a sealed connection between said aperture and said cavity, directing said liquified metal horizontally through said cavity into horizontally disposed cooling chamber means, said liquified metal partially cooling and solidifying in said mold and emanating therefrom as an elongated metal body, directing said elongated metal body horizontally through said cooling chamber means and further cooling and solidifying said elongated metal body, directing said elongated metal body horizontally into pinch roll means adapted to pull and advance said elongated metal body from said mold, oscillating said pinch roll means in horizontal directions parallel to the travel direction of said elongated metal body, and directing said elongated metal body from said pinch roll means horizontally to cut-off means and cutting off said elongated metal body into billets of desired lengths, whereby said elongated metal body is cast in a completely horizontal position.

I provide apparatus for carrying out the above method comprising, in combination, tundish means having an aperture opening horizontally into a horizontally disposed cavity of a water-cooled flow-through mold, there being a sealed connection between said aperture and said cavity, horizontal cooling chamber means adjacent said mold for containing and cooling the cast metal body emanating from said mold, pinch roll means adjacent said cooling chamber means adapted to pull and advance the cast metal body from said mold through said cooling chamber means and said pinch roll means to cut-oif means disposed on the opposite side of said pinch roll means from said cooling chamber means, said pinch roll means being mounted for reciprocal horizontal movement parallel to the travel direction of said cast metal body and oscillating means for imparting said reciprocal horizontal movement to said pinch roll means, whereby said metal body is continuously cast in a single horizontal plane.

I further provide that said tundish aperture, mold cavity, cooling chamber means, pinch roll means and cutoff means are disposed consecutively in a straight line whereby said metal body is cast in a completely in-line horizontal position.

In addition, said cooling chamber means preferably comprises a portion adjacent said mold having two groups of guide rollers in direct contact with opposite sides of the cast metal body adapted to contain said body emanating from said mold and a portion downstream of said first mentioned portion having only lower support rollers and side guide rollers to support and guide said body to said pinch roll means, said cooling chamber means having spray means extending along the length thereof adapted to spray coolant on said cast metal body.

' I also preferably provide that the drive means for imparting reciprocal horizontal movement to said pinch roll means include means for changing the frequency and length of stroke of said reciprocal horizontal movement.

Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment and a present preferred method of practicing the same proceeds. In the accompanying drawings, I have shown a present preferred embodiment of the invention and have illustrated a present preferred method of practicing the same in which FIGURE 1 is a partial longitudinal cross-sectional view of my fully horizontal continuous casting machine taken on the line II of FIGURE 2;

FIGURE 2 is a partial top plan view of my fully horizontal continuous casting machine;

FIGURE 3 is an end elevational view of the machine as viewed from the left of FIGURE 1;

FIGURE 4 is a sectional view of the pinch roll stand and oscillating mechanism of my machine taken along the line IV-IV of FIGURE 2;

FIGURE 5 is a side elevational view of the pinch roll stand and oscillating mechanism as viewed from the left of FIGURE 3; and

FIGURE 6 is a horizontal sectional view taken on the line VIVI of FIGURE 5.

Referring now to the drawings and initially to FIGURE 1, I provide generally a tundish 10, a flow-through mold 20, cooling chamber means 30, a pinch roll stand 40 having oscillating means 50 and cut-off means 70. It should be noted that in accordance with the invention, these portions of the machine are disposed consecutively and horizontally in a straight line so that the metal slab is cast in an in-line fully horizontal position.

As shown in FIGURE 1, tundish 10 has a horizontally disposed aperture 11 which opens into the horizontally disposed cavity 21 of mold 20. It should be noted that there is a sealed connection as at reference 22 between aperture 11 and cavity 21. Tundish 10 is conventionally lined as illustrated and indicated by references 13 and 14 to preserve its sides and maintain the heat of the hot metal poured into it from ladle 9 and has suitable draining apparatus 12 for clean out purposes.

Mold is a water-cooled flow-through type mold and the cooling system and circulation is clearly illustrated by arrows in FIGURE 1 with water entering into mold 20 at openings 23 and 24 and exiting therefrom at openings 25 and 26. The walls 27 of cavity 21 are thus cooled to prevent their destruction by the hot metal entering cavity 21 and moreover to partially cool and solidify the outer surfaces of the slab being cast.

Cooling chamber 30 is adjacent the side of the mold from which the slab being cast is emanating and has a roller spray apron having a lower roller bank 31, an upper roller bank 32 and side roller banks 33. These roller banks not only support the emanating metal slab but are positioned such that they contain the slab for a portion thereof adjacent mold 20 against buckling and breakout. As illustrated in FIGURE 1, further downstream from mold 20 in cooling chamber 30 the upper roller bank may portion it has been sufiiciently cooled and solidified that be dispensed with, for by the time the slab reaches this it need not be contained but rather only supported and guided by roller banks 31 and 33. Cooling chamber 30 also has a spraying system 34 entering over the full length of cooling chamber 30 which sprays coolant, generally water, on the slab as it passes therethrough to cool and further solidify the slab. As shown in FIGURE 1, nozzles 35 of spray system 34 are disposed both above and below the slab at stations located between the rolls of the roller banks. Cooling chamber 30 is suitably housed as by housing 36 to contain the flying spray within the housing. Appropriate fog exhaust means 37, drain B8 and protective refractory material 39 are valso provided to respectively exhaust steam and spray fog, to drain the coolant 1 from the chamber .and to protect the base of the chamber from hot metal drippings or runout adjacent mold 20.

Next in line downstream of cooling chamber 30 is the withdrawal equipment or pinch roll stand 40. Pinch jroll stand 40 has pinch rolls 41 which, as illustrated in FIG- URE l, are disposed above and below the slab and engage or pinch the slab. Pinch rolls 41 are rotated in the respective directions indicated by the arrows which by virtue of their pinching the slab pull or withdraw the slab from mold 20. The pinch rolls are of course adjustable to different slab thicknesses and they are driven by a variable speed drive generally shown at reference 49 a (see FIGURE 2) so that the speed of the rolls and consequently the travel speed of the slab may be varied to suit operating conditions. The roll drive mechanisms are well Within the knowledge of those skilled in the art and for that reason will not be expanded upon.

In accordance with the invention, pinch roll stand 40 is mounted for reciprocal horizontal oscillation and is oscillated so that the slab is broken loose in mold 20 according to the frequency of oscillation. Referring to FIG- URES 2 and 3, pinch -roll stand 40 is mounted on a base having a base plate 42 and a pair of upstanding side plates 43. As best shown in FIGURES 2 and 6, the side plates 44 of pinch roll stand 40 carry lugs 45 and the side plates 43 of the base carry lugs 46. Lugs 45 and 46 t on the respective side plates have openings or bores that are aligned to receive therethrough rods 47. As illustrated in FIGURE :3, pinch roll stand 40 is supported on rods 47 through lugs 45. Referring again to FIGURE 2,

springs 48 are centrally disposed on rods 47. Each spring 48 being disposed between a lug 45 of a side plate 44 and a lug 46 of a side plate 43. As further shown, rods 47 are disposed in a direction axially parallel to the slab line of travel. From the drawings and the foregoing description it is clear that pinch roll stand 40 is movable along rods 47 in directions parallel to the travel direction of the slab being cast. It should also be clear that when pinch roll stand 40 is advanced away from cooling chamber 30 it will pull or tug the slab in the direction of travel of the slab and break the slab loose in mold 20 and advance the slab therefrom. It is also clear from FIGURE 2 that as pinch -r oll stand 40 is so advanced, springs 48 are compressed on rods 47 between lugs 45 and 46. This spring pressure is suflicient to return pinch roll stand 40 to its original position immediately adjacent cooling chamber 30 as the forces advancing pinch roll stand 40 are abated.

I also provide an oscillating means 50 which is illustrated in FIGURES 3 through 6. Referring to FIGURE 4, oscillating means 50 is mounted on base plate 42 and comprises a cam 51 keyed to a shaft 52 rotatably mounted in suitably hushed trunnions 53. Cam 51 is rotated preferably by drive means 49 also (see FIGURE 2) so that the rotation of cam 51 may be synchronized to a desired degree with the rotation of rolls 41. Referring still to FIG- URE 4, adjacent the upstream or forward end of pinch roll stand 40, a shaft 54 is rotatably mounted in suitably hushed trunnions -55 secured to base plate 42. Keyed to shaft 54 are a pair of lever arms 56 which have pads 57 at the ends thereof which bear against the leading edges of side plates 44 of pinch roll stand 40 (see FIGURE 6). Also keyed to shaft '54 is a lever arm 58. As best shown in FIGURES 3 and 5, lever arm 58 is disposed on shaft 54 outboard of pinch roll stand 40. It will be understood therefrom that any movement of lever arm 58 will be translated into rotation of shaft 54, swinging of lever arms 56 and movement of pinch roll stand 40 along rods 47.

As shown in FIGURE 5, lever arm 58 is arced and has an arced window 67 therein. A roller 59 extends axially through the window and is rotatably mounted between the ends of two pusher arms 60 disposed on either side of lever arm 58 (see FIGURE 6). Pusher arms 60 are bifurcated at their other ends which are slidably mounted on guide blocks 68 which in turn are swingably mounted on shaft 52 on either side of cam 51. A cam follower 61 is rotatably disposed adjacent cam 51 on a shaft 62 extending between and secured in pusher arms 60. [From this it will be understood that pusher arms 60 are moved as cam follower '61 is moved by cam 51 and that consequently lever arm 58 is moved also, which is translated into pinch roll stand 40 movement as earlier described. Thus as shown and described eac'h rotation of cam 51 produces an oscillation of pinch roll stand 40. It will be understood, of course, that the cam surface can be altered to produce a multiplicity of oscillations per cam rotation if desired. For present purposes of illustration, however, I have illustrated a cam that produces one oscillation per revolution.

To vary the length of stroke of the oscillation, I provide a threaded shaft 63 extending from base plate 42, to which it is rotatably anchored in support member 64, upwardly between pusher arms 60 and beyond, ending in a hand wheel 65 keyed to shaft 63. A threaded nut 66 is disposed on shaft 63 and is swivelably connected to guide blocks 66a slidably disposed in windows 66b cut in pusher arms 60. A spacer 69 is rigidly connected between pusher arms 60 to hold pusher arms 60 rigidly together. From FIGURES 4 and 5, it is clear that by turning wheel 65, nut 66 caused to move up or down shaft 63 which in turn swings pusher arms 60 about shaft 52 and raises or lowers roller 59 in window 67 of lever arm 58.

It will be understood that by virtue of the arc of lever arm 58 and its window 67, the degree of rotary movement of lever arm 58 will depend upon where roller 59 bears upon it when pusher arms 60 are moved by cam 51. It is also clear from the showing of FIGURES 4 and 5 that the higher roller 59 is in window 67 the less distance lever arm 58 will be rotated, and the less distance pinch roll stand 40 will be oscillated. It is believed that a range of from 0.3 inch to 2.0 inch is most suitable for the oscillation stroke length needed to handle most operations and accordingly the arc and length of lever arm 67 as shown accommodates this range with the longer stroke setting of 2.0 inch being at the lower end of window 67, and the shorter stroke setting of 0.3 inch being at the upper end of window 67. FIGURES 4 and 5 show the pusher arms at the 2.0 inch setting with the high lobe of cam 51 bearing against cam follower 61 so that pinch roll stand 40 is at its stroked or advanced position away from cooling chamber 30 which is the position pinch roll stand 40 is in when it has just finished tugging or advancing the slab from mold 20. From this it is clear that the length of movement of pinch roll stand 40 on rods 47 may be set anywhere between 0.3 inch to 2.0 inch and will be set by the operator in accordance with the needs of the slab being cast.

Downstream from pinch roll stand 40 is cut-off means 70. Cut-oif means 70 includes a long support 71 on which slab 8 is run out and is shown generally in FIGURE 1 and may comprise any one of a number of suitable means for cutting off lengths of the cast slab into slabs of desired length. Generally, for the slabs contemplated to be cast in my machine, it is necessary to use a torch type cut-off 72 which travels with the slab as it emanates from the pinch roll stand and burns off the slab during its travel away from the pinch roll stand and then returns toward the pinch roll stand to make the next cut-01f. This type of cut-off is well known to those skilled in the art and thus will not be further expanded upon except to say that it is in-line horizontally with the rest of the machine so that the slab is cast and the billet cut off in a single straight line horizontal position.

In describing my new method of casting elongated metal bodies such as slabs and referring to FIGURE 1, I cast hot liquid metal from ladle 9 into tundish 10 having an aperture 11 that opens horizontally into a horizontally disposed water-cooled flow-through mold 20, the metal is directed horizontally through cavity 21 of mold 20 where it is partially cooled and solidified and emanates therefrom into horizontally disposed cooling chamber 30 where it is further cooled and solidified, the cast metal body is then directed horizontally through pinch roll stand 40 to cut-off means 70 where it is cut off into billets of desired length. Rollers 41 of pinch roll stand 40 grip the slab and pull and advance the slab from mold 20. Pinch roll stand 40 is oscillated so that the slab is tugged or pulled at intervals to break it loose from the walls 27 in mold 20. Oscillating means 50 is variable to change both the frequency and length of stroke in the oscillation of pinch roll stand 40.

The speed of rolls 41, the frequency and length of stroke as well as the speed of the stroke are all selected and set by the operator in accordance with operating conditions and will depend upon such things as slab size, the material being cast, the material of the cavity walls of the mold and the temperatures of the coolant and molten metal.

These operational matters are within the skill of those skilled in the art and need not be discussed in describing the present invention.

While I have shown and described a present preferred embodiment of the invention and have illustrated a present preferred method of practicing the same, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

I claim:

1. Apparatus for continuous casting of elongated metal bodies comprising, in combination, tundish means having an aperture opening horizontally into a horizontally disposed cavity of a water-cooled flow-through mold, there being a sealed connection between said aperture and said cavity, horizontal cooling chamber means adjacent said mold for containing and cooling the cast metal body emanating from said mold, pinch roll means adjacent said cooling chamber, means adapted to pull and advance the cast metal body from said mold through said cooling chamber means and said pinch roll means to cut-01f means disposed on the opposite side of said pinch roll means from said cooling chamber means, said pinch roll means being mounted for reciprocal horizontal movement parallel to the travel direction of said cast metal body and oscillating means for imparting said reciprocal horizontal movement to said pinch roll means, whereby said metal body is continuously cast in a single horizontal plane.

2. Apparatus for continuous casting of elongated metal bodies as claimed in claim 1 wherein said tundish aperture, mold cavity, cooling chamber means, pinch roll means and cut-off means are disposed consecutively in a straight line whereby said metal body is cast in a completely in-line horizontal piston.

3. Apparatus for continuous casting of elongated metal bodies as claimed in claim 1 wherein said cooling chamber means comprises a portion adjacent said mold having two groups of guide rollers in direct contact with opposite sides of the cast metal body adapted to contain said body 7 8 emanating from said mold and a portion downstream of References Cited by the Examiner said first mentioned portion having only lower support UNITED STATES PATENTS rollers and side guide rollers to support and guide said body to said pinch roll means, said cooling chamber means 2740177 4/1956 2252001 having spray means extending along the length thereof 5 30451299 7/1962 Stelgerwald 22 57-2 adapted to spray coolant on said cast metal body. FOREIGN PATENTS b Appalrafus gi i i f f g fi g 1,340,276 79/1963 France.

0 res as 0 aims in c mm W erem sar osc a mgm ns 334,392 1/1959 Switzerland for imparting reciprocal horizontal movement to said pinc'h roll means includes means for ehanging the fre- 10 L SPENCER OVERHOLSER, Fri-mam Examiner quency and length of stroke of said reciprocal horizontal movement, R. S. ANNEAR, Assistant Examiner.

Claims (1)

1. APPARATUS FOR CONTINUOUS CASTING OF ELONGATED METAL BODIES COMPRISING, IN COMBINATION, TUNDISH MEANS HAVING AN APERTURE OPENING HORIZONTALLY INTO A HORIZONTALLY DISPOSED CAVITY OF A WATER-COOLED FLOW-THROUGH MOLD, THERE BEING A SEALED CONNECTED BETWEEN SAID APERTURE AND SAID CAVITY, HORIZONTAL COOLING CHAMBER MEANS ADJACENT SAID MOLD FOR CONTAINING AND COOLING THE CAST METAL BODY EMANATING FROM SAID MOLD, PINCH ROLL MEANS ADJACENT SAID COOLING CHAMBER, MEANS ADAPTED TO PULL AND ADVANCE THE CAST METAL BODY FROM SAID MOLD THROUGH SAID COOLING CHAMBER MEANS AND SAID PINCH ROLL MEANS TO CUT-OFF MEANS DISPOSED ON THE OPPOSITE SIDE OF SAID PINCH ROLL MEANS FROM SAID COOLING CHAMBER MEANS, SAID PINCH ROLL MEANS BEING MOUNTED FOR RECIPROCAL HORIZONTAL MOVEMENT PARALLEL TO THE TRAVEL DIRECTION OF SAID CAST METAL BODY AND OSCILLATING MEANS FOR IMPARTING SAID RECIPROCAL HORIZONTAL MOVEMENT TO SAID PINCH ROLL MEANS, WHEREBY SAID METAL BODY IS CONTINUOUSLY CAST IN A SINGLE HORIZONTAL PLANE.

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