US2749584A

US2749584A - Continuous casting apparatus

Info

Publication number: US2749584A
Application number: US267638A
Authority: US
Inventors: Mathias J Fey; Howard M Ray
Original assignee: Nichols Wire and Aluminum Co
Current assignee: Nichols Wire and Aluminum Co
Priority date: 1952-01-22
Filing date: 1952-01-22
Publication date: 1956-06-12
Anticipated expiration: 1973-06-12

Description

June 12, 1956 M. J. FEY ETAL couwmuous CASTING APPARATUS 4 Sheets-Sheet 1 Filed Jan. 22, 1952 INE'N June 12, 1956 M. J. FEY ETAL CONTINUOUS CASTING APPARATUS 4 Sheets-Sheet 2 Filed Jan. 22, 1952 June 12, 1956 M. J. FEY ETAL 2,749,534

CONTINUOUS CASTING APPARATUS Filed Jan. 22, 1952 4 Sheets-Sheet 3 IIIIIIHIIIIIIIIHIHIH Inn mum

m ll l IiHlillllllUlHH] O0 INVENTORS.

36 J WXM M June 12, 1956 M. J. FEY ET AL CONTINUOUS CASTING APPARATUS 4 Sheets-Sheet 4 Filed Jan. 22, 1952 United States Patent Ofilice Patented June 12, 1956 CONTINUOUS CASTING APPARATUS Mathias J. Fey and Howard M. Ray, Davenport, Iowa, as-

signors to Nicllois Wire & Aluminum Co., Davenport, Iowa, a corporation of Missouri Application January 22, 1952, Serial No. 267,638

2 Claims. (Cl. 22-57.4)

The present invention relates to apparatus for casting metal to produce a continuous cast metal rod or strip.

Machines and apparatus for continuously casting molten metal to form a continuous cast metal rod are generally known. Essentially, such machines are arranged to provide a movable casting groove or mold in which molten metal is continuously poured to be solidified and stripped therefrom.

Difiicuities have been encountered in the art in devising a machine that will meet with any substantial degree of commercial success for a number of reasons, outstanding among which have been the difiiculties of providing apparatus to operate in truly continuous fashion and to produce a continuous cast metal rod of uniform high quality. One problem to be overcome in machines of this type is the tendency of the cast metal rod formed thereby to have numerous surface cracks and many voids and whorls in the cast section which considerably lower the quality of the cast rod. It is believed that the surface cracks and the interior voids are caused by the diificulty in properly controlling the feed of the molten metal to the casting groove and in rapidly cooling or solidifying the the molten metal and stripping the cast metal from the casting groove. The continuous operation of the casting machine has been hampered among other things by the difficulties in supplying the pouring ladle of the machine with a continuous feed of molten metal over comparatively long periods of time which, from a practical standpoint, has been difiicult to do with a reasonable number of machine operators and attendants.

It is an important object of the present invention to provide an improved apparatus for casting molten metal which will operate continuously over long periods of time to produce a continuous cast metal rod of uniform high quality.

Another object of the invention is to provide an improved form of continuous metal casting machine arranged to rapidly and thoroughly cool the molten metal to form a solidified continuous metal rod of good quality and homogeneous cross section.

Another feature of the invention is the provision in a continuous metal casting machine, of a hollow rotatable casting drum having an external peripheral casting groove and a large interior enclosure for the flow of cooling liquid therethrough, together with a cooling system having an arrangement of liquid intake and drain pipes enabling substantially the entire volume of the hollow enclosure of the drum to be continuously filled with a moving current of a large volume of cooling liquid.

Further objects, features, and the attending advantages of the present invention will be apparent with reference to the following specification and drawings, in which:

Figure l is a perspective view of the continuous casting apparatus of the invention, showing the general layout of casting machine and metal melting and holding furnaces;

Figure 2 is a perspective elevation to show the details of the casting machine;

Figure 3 is a fragmentary section through the rotatable casting drum to show details of the cooling system;

Figure 4 is a fragmentary top plan view showing the metal pouring ladle for the casting machine;

Figure 5 is a longitudinal section through the pouring ladle taken along the lines 5'5 of Fig. 4;

Figure 6 is a side elevation of the casting machine to show the adjustable features of the machine; and

Figure 7 is a fragmentary view, partly in section, of the endless band cleaning element.

Referring to Figure 1 of the drawings for a more detailed description of the general layout of the continuous casting apparatus of the invention, the continuous casting machine is generally indicated at 10. A plurality of metal melting furnaces 11, 12, and a holding or storing furnace 13 are positioned in a novel arrangement in combination with the continuous casting machine 10 to assure a flexibly controlled, continuous supply of molten metal to be cast. The particular layout arrangement of furnaces as shown in Figure l is somewhat out of proportion for purposes of illustration, and it should be understood that the invention is not limited to the exact arrangement shown. Each of the furnaces 11, 12, and 13 may be of any suitable type such as the electric induction type, and is mounted on a framework by means of which the furnaces may be controllably tilted to cause molten metal to flow from the furnaces through the respective molten metal outlets 15, 16, and 17 and into the respective refractory lined conduits 18, 19, and 20. The furnaces 11 and 12 are arranged to be supplied with metal billets to be melted while the furnace 13 is intended to function as a holding pot to receive molten metal from either of the metal melting furnaces 11 and 12 and store such metal for controlled feeding through the refractory conduit 24) to the heated metal pouring ladle 21 of the continuous casting machine 10. With such an arrangement, the flexiblity is such that either of the furnaces 11 and 12 may be shut down for repairs or may contain different metals, if, for example, a metallic alloy is to be cast. The metal melting furnaces 11 and 12 are mounted on raised

platforms

22 and 23, respectively, in a position to be elevated above the holding pot or furnace 13 so that molten metal from the furnaces 11 and 12 will fiow by gravity through the conduits 18 and 19 to the holding furnace 13. Similarly the holding furnace 13 is positioned to be elevated above the metal pouring ladle 21 so that molten metal will flow by gravity through the conduit 26 when the holding furnace 13 is tilted. The furnaces 11, 12 and 13 are tilted to individually control the flow of metal therefrom by means of suitable servo-mechanisms (not shown). The

control buttons

25, 26 and 27, located on the casting machine 10 at the casting operators station are provided to remotely control the tilting operations of the respective furnaces. Thus the casting machine operator may easily control the how of molten metal from the metal melting furnaces, and the molten metal holding furnace, to the pouring ladle of the continuous casting machine.

The room layout of the casting machine 10 and furnaces 11-13 as generally shown by Fig. l is compact and efficient and may be arranged in a substantially square floor space of about sixteen feet on each side. When casting aluminum rod, for example, to produce rolled aluminum wire, a rolling machine may be positioned to receive the cast rod directly as it emerges from the casting machine. In one commercial application of the invention the rolling mill having a length of about 28 feet is positioned approximately 20 feet from the casting machine giving a total length of floor space from melting furnaces to the output end of the rolling mill of only about to feet.

Molten metal from the pouring ladle 21 is fed by the pouring spout 30 into the peripheral casting groove of the hollow rotatable casting drum 31. The hollow casting drum 31 is adapted to be continuously filled with a moving current of cooling liquid. The casting drum 31 is rotated by suitable power transmission means enclosed within the base housing 32 and is provided with a variable speed control means that is controlled by the hand wheel 33. Details of the transmission are not shown and it may take various forms, preferably having an electric motor drive. The push button switch 34 controls the application of power to the electric motor of the power transmission for rotating the casting drum. A pan 35 is fastened to the base portion 32 of the machine and is adapted to contain a quantity of continuously moving cooling liquid about the lower half of the rotatable casting drum 31, thus providing a further source of cooling liquid to aid in rapidly solidifying the molten metal in the casting groove. The arrangement of the cooling liquid inlet and

outlet pipes

39a and 39b respectively, for the pan 35, is most clearly shown in Fig. 2 of the drawings.

An endless metal band 36 is looped about a portion of the periphery of the casting drum 31 and a portion of the periphery of an idler wheel 37 whose axis of rotation is spaced horizontally and vertically from the axis of rotation of the casting drum. The axle mechanism of the idler wheel 37 is provided with an eccentric bearing portion (not shown in detail) which, in response to the weighted arm 38, causes the idler wheel to tension the endless band 36 against the periphery of both the idler wheel 37 and the casting drum 31. The weight 38 is movable on its supporting arm to provide a degree of control for the tension of the endless band 36. The endless band 36 engages a portion of the periphery of the casting drum 31 to form a closure wall for the casting groove of the casting drum that is movable coincidentally with the rotation of the casting drum 31. In view of the simple loop configuration of the endless band, the band is long wearing and may be formed of various thicknesses and of different materials suitable for different metals to be cast. In such manner a movable casting mold in which molten metal may be continuously solidified to form a continuous cast metal rod is provided. Cast metal rod is shown at 40 and it will be seen that it is stripped from the casting drum 31 near the point of departure of the endless band 36 from the casting drum 31 and is lopped over the casting machine with a general curvature in the direction of rotation of the casting drum. The casting drum 31 is arranged to rotate in a clockwise direction as shown by the arrow on Fig. l.

The cast metal rod 40, as it is stripped from the casting drum 31, is guided in its passage over the casting drum and to one side of the endless band 36 by the guide member 41 which consists of a generally triangular shaped frame member depending from the axis of idler wheel 3'7. An additional guide member 42 is mounted on the base frame 32 of the machine and is provided with a coil spring 43 to cause the guide member to engage the outer surface of the cast metal rod 40 and constrain the cast metal rod towards the axis of the casting drum 31, immediately as the cast rod is stripped from the casting groove. Thus any bowing action which may be present in the extended length of cast metal rod, which has been stripped from the machine, and which bowing action would tend to straighten the rod immediately as it is stripped from the drum, is resisted by the pressure of the guide member 42 so that the formation of surface cracks on the cast rod is minimized.

Many of the elements of the machine which have been described in connection with Figure 1 of the drawing are shown in greater detail in Figures 2 and 6 of the drawings, to which reference is now made for a further description of certain details. The idler wheel 37 is rotatably supported at the upper end of the generally U-shaped frame member 50. The U-shaped frame member 50 is pivotally journalled at 51 about the hub or axis of the rotatable casting drum 31. A rotatable hand wheel 52 is keyed to a threaded shaft 53 that is supported in the threaded bushing 54. The threaded bushing 54 is fastened to the base frame 32 of the machine. The shaft 53 is pivotally connected at 55 to the other end of the U-shaped frame 50. By rotating the hand wheel 52, the tilt of the frame 50 and thus the entire machine may be adjusted to predetermine the desired angle to the vertical for the straight extending portions of the endless band 36. The specific details of the connections for the shaft 53 do not form a part of the present invention and are therefore not described. A coil spring 56 is provided to counterbalance the weight of the U-shaped frame member 50 and the idler pulley 37 carried thereby.

In Figure 6 of the drawing, the casting machine is shown with the endless band removed and with the pouring ladle 21 in the extreme forward position. The pouring ladle 21 is pivotally mounted at 64 on the arm 57 which in turn is pivotally mounted about the hub 51 of the casting drum 31. The pivotal position of the arm 57 is controlled by means of the handwheel 58. Rotation of the handwheel 58 causes a rotation of the pinion gear 59 on the rack 60 which may be effective to move the connecting link 61 to the right of the drawing as shown in Fig. 6. Thus the pouring ladle 21 may be moved backwards to the operative position as shown in Fig. 2 of the drawings. A further adjustment of the tilt of the pouring ladle 21 is provided by means of the

setscrews

62 and 63 which adjust the pivotal position of the pouring ladle 21 about the pivot point 64 on the end of the pivoted arm 57.

The guide member or roller 42 is clearly shown in Fig. 6 of the drawings to be mounted on the free end of the lever arm 65 which is pivoted to the base frame 32 of the machine and urged by the tension of the coil spring 43 to pivot towards the axis of the casting drum 31.

The upper guide member 41 is provided with a pivotal shoe member 67 which is adapted to engage the inside surface of the endless band 36 as shown in Figs. 2 and 6 of the drawings. The shoe 67 may be channeled, as shown in Fig. 7 of the drawings, to receive a quantity of cotton waste which functions to clean the inside surface of the endless band 36 after the cast metal rod has been stripped from the casting groove and band. The shoe member 68, shown in Fig. 2 of the drawings, may also be adapted to contain a quantity of cotton waste for cleaning the casting groove of the casting drum 31 after the cast metal has been stripped therefrom.

A detailed description of the heated metal pouring ladle 21 will now be described in connection with Figs. 2, 4 and 5 of the drawings. The pouring ladle 21 generally comprises an outer metal box structure 70a and an inner container 70. The bottom and side walls of the inner container 70 are spaced from the inner wall surfaces of the metal box structure 70a to provide passageways for the flow of burning gases thereabout in a manner to heat the bottom and side wall-s of the container 70. The burner 71 is adapted to project a flame of burning gases through the aperture 72 into the box 21 beneath the container 70. The pouring spout 30 extends from the bottom of the container 70 through the aperture 73 of the outer box of the ladle 21. It will be noted, as shown in Figure 2 of the drawings, that the aperture 73 is somewhat larger than the external diameter of the pouring spout 30, so that the products of combustion from the burner 71 are exhausted through the aperture 73 around the external surfaces of the pouring spout 30. In such manner the pouring spout 30 is heated to prevent solidification, or partial solidification, of metal in the spout which tends to accumulate after long periods of continuous use. A transverse partition 74 extends across the path of movement of molten metal within the container 70 in its passage to the pouring spout 30. The opening 75, in the lower portion of the transverse partition 74, permits the passage and flow of molten metal from the pouring ladle container 70 to the pouring spout 30. Any scum or dross that is formed in the molten metal in the container 70' and rises to the surface of the molten metal is prevented from entering the spout 30 since the spout is at the bottom of the container. The opening 75 in the partition 74 is spaced above the bottom of the container and prevents the passage of heavy impurities which may collect at the bottom of the container.

The cooling system for the rotatable casting drum is shown in detail in Figure 3 of the drawings. The rotatable casting drum 31 is provided with the circular casting rim 78 which may be formed of copper or other suitable highly heat conductive material. The rim 78 is secured to the disc side wall 79 which is bolted to the rotatable axle sleeve 80. The outside disc side member 81 completes the assembly of the rotatable casting drum to form a hollow enclosure adapted to contain a large volume of cooling liquid 82. The rotatable axle sleeve 80 is mounted in

suitable bearings

83 and 84 carried by the machine base frame 32. A sprocket 85 and chain 86 transmit rotation to the axle sleeve 80 from the power transmission contained in the base frame 32. The rotatable axle sleeve 80 surrounds the stationary hub member or axle 88 having a conduit 89 drilled therethrough for the passage of cooling liquid into the interior of the hollow casting drum 31. A nozzle 90 projects the cooling liquid from the intake conduit 89 into the central portion of the rotatable casting drum 31. A drain pipe 91 is also passed through the stationary hub portion 88 and is provided with an upwardly extending end member 92 which extends virtually to the top of the interior of the casting drum 31 to a point just beneath the inside perimeter of the peripheral casting rim 78. Thus substantially the entire enclosed volume of the hollow casting drum may be continuously filled with a large moving volume of cooling liquid. A thermo-couple 93 may be provided to measure the temperature of the cooling liquid as it is drained through the drainpipe 91 from the interior of the rotatable casting drum 31.

Additional refinements which contribute to the overall effective operation of the continuous casting apparatus of the invention are shown in Fig. 2 of the drawings. The thermo-couple 94 may be provided to measure the temperature of the cast metal rod as it is stripped from the casting machine. The thermocouple 95 may be provided to measure the temperature of the cooling water contained in the pan 35 which surrounds the lower external surfaces of the casting drum 31. The thermocouple 96 may also be provided to measure the temperature of the molten metal in the pouring ladle 21 before it is poured into the casting groove of the casting drum.

A pressure roller 100 is carried by the adjustable guideway 101 and movable to engage the exterior surface of the endless band 36 near the point of juncture of the band 36 with the peripheral surface of rotatable casting drum 31. The control arm 102 is adapted to be rotated to move the pressure roller 100 to or from the endless band 36 as desired. It should be understood that the movement of the pressure roller 100 will vary the exact angle of contact of the endless band 36 with the peripheral surface of the casting drum 31 at the point where the molten metal is poured into the casting groove.

As shown in Figure 3 of the drawings, the casting rim 78 is provided with a casting groove having

side walls

103 and 104 forming a casting groove of generally triangular cross-section. If desired, the outer edges of the

side walls

103 and 104 may be modified at 105 and 106 to extend substantially perpendicular to the periphery of the casting drum for a short portion of their width. Such a modified form of casting groove may further facilitate the continuous stripping of the cast metal rod from the casting groove in a manner to avoid excessive strains on the cast metal rod.

The operationof the continuous metal casting apparatus of the invention should be readily apparent from the foregoing description and need not be described in detail. It should be mentioned, however, when casting aluminum for example, that the machine may be operated to cast a speed of 10 to 30 feet per minute with an average weight of aluminum cast per hour of about 1,000 pounds. After the machine has been placed into operation, the cast metal rod 40 is self-stripping. With the arrangement of continuous casting machine and metal melting furnaces as described, it is possible for a single operator to operate the machine and control the feed of molten metal thereto for long periods of time. The flexibility of the entire arrangement is such that the important factors for controlling the quality of the cast metal rod may be easily taken into consideration, and adjustments therefore may be made by a single machine operator. The cooling apparatus for the casting drum and the guide arrangements for the cast metal rod according to the invention, enable a uniformly high quality of continuously cast metal rod to be produced. The particular heating arrangement for the metal pouring ladle as used on the continuous casting machine of the invention provides for a reliable continuous and uniformly controlled flow of molten metal to be cast over long periods of time.

It should be understood that various modifications may be made within the spirit of the invention and scope of the appended claims.

We claim:

1. A rotatable casting drum for a machine for the continuous casting of molten metal into cast metal rod, said casting drum including in combination, a pair of disclike side walls disposed in spaced parallel relation for rotation about a common horizontal axis and with one of said side Walls having a central aperture therein, a circular casting rim of heat conductive material bridging respective peripheral portions of said side Walls and afiixed thereto to form a hollow enclosure adapted to contain a cooling liquid, said casting rim having an external casting groove formed therein, a rotatable axle sleeve afiixed to said one of said side walls and surrounding said central aperture therein, said sleeve extending coaxially with said horizontal axis of rotation of said side walls, means for introducing a cooling liquid into said enclosure through said sleeve, and a drain pipe extending through said sleeve into said enclosure and having an end portion extending upwardly in said enclosure to a point adjacent the internal surface of said casting rim so that substantially the entire enclosed volume of the casting drum may be continuously filled with a large moving volume of cooling liquid.

2. A rotatable casting drum for a machine for the continuous casting of molten metal into cast metal rod, said casting drum including in combination, a pair of disclike side walls disposed in spaced parallel relation for rotation about a common horizontal axis and with one of said side walls having a central aperture therein, a circular casting rim of heat conductive material bridging respective peripheral portions of said side walls and affixed thereto to form a hollow enclosure adapted to contain a cooling liquid, said casting rim having an external casting groove formed therein, a rotatable axle sleeve affixed to said one of said side walls and surrounding said central aperture therein, said sleeve extending coaxially with said horizontal axis of rotation of said side walls, means for rotatably supporting said sleeve on said horizontal axis, driving means for imparting rotational motion to said sleeve, means for introducing a cooling liquid into said enclosure through said sleeve, and a drain pipe extending through said sleeve into said enclosure and having an end portion extending upwardly in said enclosure to a point adjacent the internal surface of said casting rim so that substantially the entire enclosed volume of the casting drum may be continuously filled with a large moving volume of liquid.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Forsyth Apr. 24, 1883 Lane Dec. 28, 1926 Walters Feb. 19, 1929 McMullan Mar. 17, 1931 Lindenberger Nov. 21, 1933 Jacobson Sept. 24, 1935 Summey Nov. 10, 1936 Simons Aug. 29, 1939 Junghans Oct. 15, 1940 Harter et a1. Oct. 9, 1951 FOREIGN PATENTS France Ian. 17, 1951

Claims

1. A ROTATABLE CASTING DRUM FOR A MACHINE FOR THE CONTINUOUS CASTING OF MOLTEN METAL INTO CAST METAL ROD, SAID CASTING DRUM INCLUDING IN COMBINATION, A PAIR OF DISCLIKE SIDE WALLS DISPOSED IN SPACED PARALLEL RELATION FOR ROTATION ABOUT A COMMON HORIZONTAL AXIS AND WITH ONE OF SAID SIDE WALLS HAVING A CENTRAL APERATURE THEREIN, A CIRCULAR CASTING RIM OF HEAT CONDUCTIVE MATERIAL BRIDGING RESPECTIVE PERIPHERAL PORTIONS OF SAID SIDE WALLS AND AFFIXED THERETO TO FORM A HOLLOW ENCLOSURE ADAPTED TO CONTAIN A COOLING LIQUID, SAID CASTING RIM HAVING AN EXTERNAL CASTING GROOVE FORMED THEREIN, A ROTATABLE AXLE SLEEVE AFFIXED TO SAID ONE OF SAID SIDE WALLS AND SURROUNDING SAID CENTRAL APERTURE THEREIN, SAID SLEEVE EXTENDING COAXIALLY WITH SAID HORIZONTAL AXIS OF ROTATION OF SAID SIDE WALLS, MEANS FOR INTRODUCING A COOLING LIQUID INTO SAID ENCLOSURE THROUGH SAID SLEEVE, AND A DRAIN PIPE EXTENDING THROUGH SAID SLEEVE INTO SAID ENCLOSURE AND HAVING AN END PORTION EXTENDING UPWARDLY IN SAID ENCLOSURE TO A POINT ADJACENT THE INTERNAL SURFACE OF SAID CASTING RIM SO THAT SUBSTANTIALLY THE ENTIRE ENCLOSED VOLUME OF THE CASTING DRUM MAY BE CONTINUOUSLY FILLED WITH A LARGE MOVING VOLUME OF COOLING LIQUID.